U.S. patent application number 14/437766 was filed with the patent office on 2015-09-24 for packaging film for display device.
This patent application is currently assigned to LG CHEM, LTD.. The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Ji Young Hwang, Jae Ho Jung, In Ju Mun, Jong Sung Park, Min Soo Park, Yong Su Park, Kum Suek Seo, Se Woo Yang.
Application Number | 20150268490 14/437766 |
Document ID | / |
Family ID | 52707388 |
Filed Date | 2015-09-24 |
United States Patent
Application |
20150268490 |
Kind Code |
A1 |
Yang; Se Woo ; et
al. |
September 24, 2015 |
PACKAGING FILM FOR DISPLAY DEVICE
Abstract
Provided is a packaging film for a display device, which
includes a first region corresponding to a top surface of a
backward diode equipped on a bottom surface of a display panel; and
a second region extending from the first region and corresponding
to a side surface of the backward diode. Due to the packaging film,
a bezel region can be minimized.
Inventors: |
Yang; Se Woo; (Daejeon,
KR) ; Seo; Kum Suek; (Daejeon, KR) ; Park;
Jong Sung; (Daejeon, KR) ; Park; Min Soo;
(Daejeon, KR) ; Hwang; Ji Young; (Daejeon, KR)
; Jung; Jae Ho; (Daejeon, KR) ; Mun; In Ju;
(Daejeon, KR) ; Park; Yong Su; (Daejeon,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Assignee: |
LG CHEM, LTD.
Seoul
KR
|
Family ID: |
52707388 |
Appl. No.: |
14/437766 |
Filed: |
February 20, 2014 |
PCT Filed: |
February 20, 2014 |
PCT NO: |
PCT/KR2014/001383 |
371 Date: |
April 22, 2015 |
Current U.S.
Class: |
428/121 |
Current CPC
Class: |
G02F 2001/133325
20130101; Y10T 428/2419 20150115; G02B 6/0088 20130101; B65D 65/14
20130101; G02F 1/133308 20130101; B65D 65/38 20130101; G02F 1/1333
20130101; G02F 2001/133314 20130101; B65D 85/38 20130101; G02B
6/0051 20130101 |
International
Class: |
G02F 1/1333 20060101
G02F001/1333; B65D 65/14 20060101 B65D065/14; B65D 85/38 20060101
B65D085/38; B65D 65/38 20060101 B65D065/38 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 20, 2013 |
KR |
10-2013-0018123 |
Jun 19, 2013 |
KR |
10-2013-0070623 |
Aug 1, 2013 |
KR |
10-2013-0091343 |
Aug 1, 2013 |
KR |
10-2013-0091469 |
Aug 1, 2013 |
KR |
10-2013-0091470 |
Aug 1, 2013 |
KR |
10-2013-0091471 |
Claims
1. A packaging film for a display device, comprising: a first
region corresponding to a top surface of a backward diode equipped
on a bottom surface of a display panel; and a second region
extending from the first region and corresponding to a side surface
of the backward diode.
2. A packaging film for a display panel, comprising: a first region
corresponding to a top surface of a display panel; and a second
region extending from the first region and corresponding to a side
surface of the display panel and a side surface of a backward diode
equipped on a bottom surface of the display panel.
3. The film according to claim 1 or 2, further comprising: a third
region extending from the second region and corresponding to the
bottom surface of the backward diode.
4. The film according to claim 1 or 2, wherein two to four second
regions are included.
5. The film according to claim 1 or 2, wherein the packaging film
has an absolute value of in-plane retardation (R.sub.in) of 30 nm
or less.
6. The film according to claim 1 or 2, wherein the packaging film
has an absolute value of thickness-direction retardation (R.sub.th)
of 35 nm or less.
7. The film according to claim 3, which has a notch part formed on
a boundary line between the first and second regions, or a boundary
line between the second and third regions.
8. The film according to claim 3, wherein the first and second
regions or the second and third regions have a bending strength of
1.0 to 10.0 gf on each boundary line.
9. The film according to claim 1 or 2, wherein the packaging film
has a thickness, which satisfies an area of the first region and
the following Equation: T [.mu.m]=100.times.S [m.sup.2]+a
[Equation] where T is a thickness (.mu.m) of the packaging film, S
is an area (m.sup.2) of the first region, and a is a number from 15
to 130.
10. The film according to claim 1 or 2, which has at least one
selected from the physical properties (a) to (c): (a) tensile
modulus of 1,200 MPa or more (b) tensile strength of 40 MPa or more
(c) elongation of 20% or more.
11. The film according to claim 1 or 2, which has a strain (E)
according to the following Equation of 5% or less: E
(%)=[(L2-L1)/L1].times.100 [Equation] where L1 is an initial length
of the packaging film, and L2 is an extending length of the
packaging film after being maintained for 24 hours by applying a
load of 3 kg at 80.degree. C.
12. The film according to claim 3, wherein the third region has an
overlap prevented part for preventing overlap with an adjacent
third region when the third region is located to correspond to the
bottom surface of the backward diode through a bending process.
13. The film according to claim 1 or 2, wherein the second region
is light-impermeable.
14. The film according to claim 1 or 2, wherein a light-impermeable
part is formed at an edge of the first region.
15. The film according to claim 1 or 2, wherein the first region
includes a projecting part from which the second region does not
extend.
16. The film according to claim 1, wherein adhesive treatment is
performed on a top surface of the first region.
17. The film according to claim 1 or 2, wherein the second region
has a ribbed bottom surface.
18. The film according to claim 1 or 2, wherein the packaging film
includes at least one selected from a polycarbonate-based resin, a
polyester-based resin, a polyolefin-based resin, a cyclo-olefin
polymer-based resin, an acryl-based resin, a urethane-based resin,
an epoxy-based resin, a polyamide-based resin, a cellulose-based
resin, a nylon-based resin and a derivative thereof.
19. The film according to claim 1 or 2, further comprising: a
pressure-sensitive adhesive layer formed on the first region.
20. The film according to claim 19, wherein the pressure-sensitive
adhesive layer has a room temperature storage modulus of
6.0.times.10.sup.5 dyn/cm.sup.2 or more.
21. The film according to claim 19, wherein the pressure-sensitive
adhesive layer has a peeling strength of 0.8 kgf/cm or more when
peeled at room temperature and a peeling rate of 30 mm/min.
22. The film according to claim 19, wherein the pressure-sensitive
adhesive layer includes a photocurable pressure-sensitive adhesive
composition, and has a room temperature storage modulus of
1.0.times.10.sup.6 dyn/cm.sup.2 or more after curing.
23. The film according to claim 1 or 2, further comprising: a
protective film formed on the first region; and a
pressure-sensitive adhesive layer formed on the protective
film.
24. The film according to claim 23, wherein the protective film
includes at least one selected from triacetyl cellulose (TAC) and
an acrylic resin.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present application relates to a packaging film for a
display device with which an improved display device can be
embodied.
[0003] 2. Discussion of Related Art
[0004] A display device is useful in various electronic products.
For example, a device such as a liquid crystal display (LCD) is
used in various products including a mobile phone, a personal
digital assistant (PDA), an electronic game console, a monitor and
a TV.
[0005] Generally, a display device has a display panel displaying
an image. In addition, most of the display devices include a
backward diode equipped on a bottom surface of the display panel.
For example, an LCD device includes a back light unit (BLU) as a
backward diode.
[0006] FIG. 1 is a cross-sectional diagram showing a display
device, and particularly, an LCD device, according to conventional
art.
[0007] Referring to FIG. 1, the LCD device has an LCD panel 10
displaying an image. Generally, the LCD panel 10 is not
self-emissive, and thus realizes an image by receiving light from
an external environment. Accordingly, a backlight unit 20 is
equipped as a backward diode on a bottom surface of the LCD panel
10.
[0008] The backlight unit 20 includes, for example, a light source
22 such as a light emitting diode (LED), a light guide plate 24
inducing light emitted from the light source 22 to the LCD panel 10
and converting a point light source generated from the light source
22 to a surface light source, and a diffuser sheet 26 diffusing
light emitted from the light guide plate 24.
[0009] In addition, the LCD panel 10 has a liquid crystal cell
layer 12 composed of liquid crystals changed in light transmittance
due to application of an electrical signal. The LCD panel 10
transmits or blocks light by changing or maintaining a polarizing
direction of linearly polarized light transmitted by liquid
crystals are penetrated according to arrangement of the liquid
crystals. To this end, the LCD panel 10 has an upper polarizing
plate 14 formed on the liquid crystal cell layer 12 and a lower
polarizing plate 16 formed under the liquid crystal cell layer
12.
[0010] In addition, the conventional display device including the
LCD device includes a molding frame 30 to assemble component
members. As shown in FIG. 1, a backlight unit 20 is stacked on a
bottom surface of the LCD panel 10, and then assembled and fixed by
the molding frame 30 formed of a resin.
[0011] For example, related techniques are disclosed in Korean
Patent Nos. 10-0824866, 10-0876236, 10-0876248 and 10-1178577.
[0012] However, the display device according to the conventional
art has a bezel B as shown in FIG. 1 due to the use of the molding
frame 30 as described above, and an area of the bezel B is also
large. Due to such a bezel B, a display on which an actual image is
shown becomes smaller than a surface area of the LCD panel 10.
[0013] In addition, the display device according to the
conventional art may have problems in handling and assembly of the
backward diode, that is, the backlight unit 20. For example, an
assembling process using the molding frame 30 by inserting and
fixing an optical member such as the light guide plate 24 or the
diffuser sheet 26 to the molding frame 30 and stacking these
components on the bottom surface of the LCD panel 10 may take too
much time, and the optical members 24 and 26 may be damaged.
Moreover, according to the assembly using the molding frame 30, a
light leakage phenomenon may occur due to decreased sealability.
Such a problem may bring an increase in costs and a decrease in
yield of the display device, and have a bad influence on
performance.
SUMMARY OF THE INVENTION
[0014] The present application is directed to providing a packaging
film for a display device through which an improved display device
can be embodied. The present application provides, for example, a
packaging film for a display device that minimizes a bezel
region.
[0015] One aspect of the present application provides a packaging
film for a display device, which includes a first region
corresponding to a top surface of a backward diode equipped on a
bottom surface of a display panel; and a second region extending
from the first region and corresponding to a side surface of the
backward diode.
[0016] Another aspect of the present application provides a
packaging film for a display device, which includes a first region
corresponding to a top surface of a display panel; and a second
region extending from the first region and corresponding to a side
surface of the display panel and a side surface of the backward
diode equipped on a bottom surface of the display panel.
[0017] According to a first embodiment of the present application,
the packaging film for a display device may have an in-plane
retardation (R.sub.in) of 30 nm or less.
[0018] According to a second embodiment of the present application,
the packaging film for a display device may have a
thickness-direction retardation (R.sub.th) of 35 nm or less.
[0019] According to a third embodiment of the present application,
the packaging film for a display panel may include a notch part
formed on a boundary line between the first region and the second
region.
[0020] According to a fourth embodiment of the present application,
a thickness of the packaging film for a display device may satisfy
an area of the first region and the following Equation.
T [.mu.m]=100.times.S [m.sup.2]+a [Equation]
[0021] In Equation, T is a thickness of the packaging film (unit:
.mu.m), S is an area of the first region (width.times.length, unit:
m.sup.2), and a is a number from 15 to 130.
[0022] According to a fifth embodiment of the present application,
the packaging film for a display device may have at least one
selected from the physical properties (a) to (c):
[0023] (a) tensile modulus of 1,200 MPa or more
[0024] (b) tensile strength of 40 MPa or more
[0025] (c) elongation of 20% or more
[0026] According to a sixth embodiment of the present application,
the packaging film may have a strain (E) according to the following
Equation of 5% or less.
E (%)=[(L2-L1)/L1].times.100 [Equation]
[0027] In the Equation, L1 is an initial length (width or length)
of the packaging film, and L2 is an extending length of the
packaging film after being maintained for 24 hours by applying a
load of 3 kg at 80.degree. C.
[0028] According to a seventh embodiment of the present
application, the packaging film for a display device may further
include a third region extending from the second region and
corresponding to a bottom surface of the backward diode. An overlap
prevented part may be formed in the third region.
[0029] According to an eighth embodiment of the present
application, in the packaging film for a display device, at least
the second region of the second and third regions may have light
impermeability.
[0030] According to a ninth embodiment of the present application,
in the packaging film for a display device, a light-impermeable
part may be formed at an edge of the first region.
[0031] According to a tenth embodiment of the present application,
the packaging film for a display device may include a projecting
part in the first region.
[0032] According to an eleventh embodiment of the present
application, in the packaging film for a display device, an
adhesion-facilitating part may be formed on a top surface of the
first region.
[0033] According to a twelfth embodiment of the present
application, in the packaging film for a display device, a bottom
surface of the first region may have a ribbed surface.
[0034] According to a thirteenth embodiment of the present
application, the packaging film for a display device may further
include a pressure-sensitive adhesive layer formed on the first
region.
[0035] According to a fourteenth embodiment of the present
application, the packaging film for a display device may further
include a polarizing layer formed on the first region, and a
pressure-sensitive adhesive layer formed on the polarizing
layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other objects, features and advantages of the
present application will become more apparent to those of ordinary
skill in the art by describing in detail exemplary embodiments
thereof with reference to the adhered drawings, in which:
[0037] FIG. 1 is a cross-sectional view of a display device
according to a conventional art;
[0038] FIG. 2 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0039] FIG. 3 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0040] FIG. 4 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0041] FIG. 5 is a plan view of a packaging film according to an
embodiment of the present application;
[0042] FIG. 6 is a cross-sectional view taken along line A-A' of
FIG. 5;
[0043] FIG. 7 is a plan view of a packaging film according to an
embodiment of the present application;
[0044] FIG. 8 is a plan view of a packaging film according to an
embodiment of the present application;
[0045] FIG. 9 is a plan view of a packaging film according to an
embodiment of the present application;
[0046] FIG. 10 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0047] FIG. 11 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0048] FIG. 12 is a cross-sectional view of a display device
according to an embodiment of the present application;
[0049] FIG. 13 is a plan view of a packaging film according to an
embodiment of the present application;
[0050] FIG. 14 is a cross-sectional view taken along line A-A' of
FIG. 13;
[0051] FIG. 15 is a plan view of a packaging film according to an
embodiment of the present application;
[0052] FIG. 16 is a plan view of a packaging film according to an
embodiment of the present application; and
[0053] FIG. 17 is a plan view of a packaging film according to an
embodiment of the present application.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0054] In the specification, the term "and/or" includes at least
one of the listed components.
[0055] In the specification, the terms "first," "second" and
"third" are used to discriminate one component from other
components, and these elements are not limited by these terms.
[0056] In the specification, the terms representing a direction
such as "top surface," "side surface," and "bottom surface" are,
unless specifically defined otherwise, based on directions of a
display device seen by an observer (viewer).
[0057] In the specification, the term "corresponding" means that
surfaces facing each other partially or entirely correspond to each
other.
[0058] In the specification, the terms "formed on," "formed above,"
"formed under," and "formed on a side surface" do not only mean
that corresponding components are stacked in direct contact with a
different surface, but also include cases in which a different
component is formed between the corresponding components. For
example, the term "formed on" may indicate that a second component
is formed in direct contact with a first component, or that a third
component is also formed between the first component and the second
component.
[0059] In the specification, the term "extension" may not imply
that any one component (first component) is extended and formed in
one process with another component (second component), but may
indicate that two components (first and second components) are
detachable members, and thus are extended by connection even when
they are not formed in one process.
[0060] In the specification, the term "light transmittance" may
indicate that radiated visible rays have a transmittance of 60% or
more, for example, 80% or more, for example, 90% or more on a
straight line. In the specification, the term "light
impermeability" may indicate that radiated visible rays have a
transmittance of, for example, 40% or less, for example, 30% or
less, for example, 20% or less, for example, 10% or less on a
straight line.
[0061] Hereinafter, display devices according to first and second
embodiments of the present application will be described with
reference to the accompanying drawings. The accompanying drawings
show exemplary embodiments of the present application, and are
provided to help understanding of the present application. In the
accompanying drawings, to clearly express various layers and areas,
thicknesses are exaggerated, and the scope of the present
application is not limited by the thicknesses, sizes and ratios
shown in the drawings. In description of the present application,
detailed descriptions of related known general functions or
components will be omitted.
[0062] The present application provides packaging films 300 and
300' to package a display device. The packaging film 300 according
to the first embodiment of the present application is used to
package a backward diode 200 equipped on a bottom surface of the
display panel 100. The packaging film 300' according to the second
embodiment of the present application is used to package a display
panel 100 and a backward diode 200. Further, the present
application provides a display device including the packaging film
300 or 300' according to the first or second embodiment of the
present application. Exemplary examples of the present application
will be described below.
First Embodiment
[0063] Examples of the packaging film 300 according to the first
embodiment of the present application are shown in FIGS. 2 to
9.
[0064] The packaging film 300 according to the first embodiment of
the present application packages a backward diode 200 equipped on a
bottom surface of a display panel 100. The packaging film 300
surrounds and packages at least a top surface 201 and a side
surface 202 of the backward diode 200. To this end, the packaging
film 300 includes a first region 310 corresponding to the top
surface 201 of the backward diode 200 and a second region 320
corresponding to the side surface 202 of the backward diode 200.
The second region 320 extends from the first region 310.
[0065] The display device includes the packaging film 300 described
in the present application. According to an exemplary embodiment,
the display device includes a display panel 100, a backward diode
200 equipped on a bottom surface of the display panel 100, a
packaging film 300 for packaging the backward diode 200, and a
pressure-sensitive adhesive layer 400 formed between the display
panel 100 and the packaging film 300. The pressure-sensitive
adhesive layer 400 adheres and fixes the display panel 100 to the
packaging film 300.
[0066] According to the present application, an improved display
device is embodied. For example, a bezel region is minimized by
adhering and fixing the display panel 100 and the backward diode
200 using the packaging film 300 and the pressure-sensitive
adhesive layer 400. According to the present application, the use
of a molding frame 30 (refer to FIG. 1) may be excluded, and thus a
display device having almost no bezel may be embodied. In addition,
the problems generated in the handling and assembly of the backward
diode 200 are minimized or eliminated, for example, an optical
diode on a film (or a sheet).
[0067] Hereinafter, in the explanation of an exemplary example of
the first embodiment, the packaging film 300 of the present
application will also be explained during the explanation of the
display device.
[0068] In the present application, the display panel 100 may be any
one that can display an image without specific limitation.
[0069] The display panel 100 may include, for example, a component
displaying an image by changing light transmittance, or a component
displaying an image by emitting light from a fluorescent substrate.
Particularly, the display panel 100 may be selected from an LCD
panel displaying an image using liquid crystals changed in light
transmittance, a plasma display panel (PDP) displaying an image by
generating gas discharging between two electrodes and emitting
light from a fluorescent substrate due to UV rays generated by the
gas discharging, and/or an organic electroluminescent display panel
displaying an image by emitting light from an organic light
emitting diode (OLED) due to electric excitation occurring in an
electrode.
[0070] FIGS. 2 to 4 show display panels 100 according to exemplary
embodiments of the present application. FIGS. 2 to 4 specifically
show LCD panels.
[0071] Referring to FIGS. 2 to 4, the display panel 100 includes,
for example, at least one liquid crystal cell layer 120, and
polarizing plates 140 and 160 formed on both surfaces of the liquid
crystal cell layer 120. The polarizing plates 140 and 160 may
include an upper polarizing plate 140 formed on the liquid crystal
cell layer 120 and a lower polarizing plate 160 formed under the
liquid crystal cell layer 120.
[0072] The liquid crystal cell layer 120 may include, for example,
a thin film transistor (TFT) substrate, a color filter substrate
facing the TFT substrate, and a liquid crystal cell interposed
between the two substrates and in light transmittance is changed by
applying an electrical signal.
[0073] The upper polarizing plate 140 and the lower polarizing
plate 160 may have a polarizing characteristic, and their optical
axes may be orthogonal to each other. For example, the optical axis
of the upper polarizing plate 140 may be placed in a vertical
direction of the display panel 100, and the optical axis of the
lower polarizing plate 160 may be placed in a horizontal direction
of the display panel 100. In one example, the upper polarizing
plate 140 and the lower polarizing plate 160 may each include a
polarizer and a protective film formed on one or both surfaces of
the polarizer. The polarizer may be selected from, for example,
polarizable polyvinylalcohol (PVA) films. In addition, the
protective film may be a film including at least one selected from,
for example, triacetyl cellulose (TAC) and an acrylic resin. Other
than these, a pixel electrode for driving a pixel may be formed in
the display panel 100, and which is omitted from the drawing.
[0074] In addition, the display panel 100 may further include a
different functional film or layer, in addition to the liquid
crystal cell layer 120, the upper polarizing plate 140 and the
lower polarizing plate 160. The display panel 100 may further
include a light diffusion layer, a viewing angle compensation film,
a retardation film, an anti-reflection layer, an anti-glare layer
and/or a protective film layer for protecting these components.
Moreover, such films and layers may be formed on the upper
polarizing plate 140 or the lower polarizing plate 160. For
example, at least one selected from a light diffusion layer, an
anti-reflection layer, an anti-glare layer and a protective film
for protecting these components may be further formed on the upper
polarizing plate 140. These components, as separate members, may be
stacked on the upper polarizing plate 140, or may be directly
formed on a top surface of the upper polarizing plate 140. As an
example, the anti-glare layer may be directly formed on a top
surface of the upper polarizing plate 140 through surface treatment
such as haze treatment.
[0075] In the present application, the backward diode 200 may be
equipped on a bottom surface of the display panel 100 without
specific limitation. The backward diode 200 may be formed of one
member, or have a multi-layer structure including at least two
members. Shapes and functions of the members constituting the
backward diode 200 are not limited. The backward diode 200 may
have, for example, a form of a film, sheet, planar plate and/or a
three-dimensional device. Particularly, for example, the backward
diode 200 may include at least one selected from an
electric/electronic diode having an electric/electronic function,
an optical diode having an optical function, and/or a heat
dissipation diode having a heat dissipation function. Such a
backward diode 200 is surrounded by a packaging film 300 as will be
described below.
[0076] FIG. 2 shows a backward diode 200 composed of one member.
Here, the backward diode 200 shown in FIG. 2 may be selected from,
for example, an optical diode 200A, an electronic circuit board and
a heat dissipation plate. Specifically, for example, the backward
diode 200 may be selected from the optical diode 200A.
[0077] In the present application, the optical diode 200A has an
optical function without limitation. The optical diode 200A may be,
for example, a diode having functions such as diffusion,
concentration, polarization and/or reflection of light, but the
present application is not limited thereto. In addition, the
optical diode 200A may include a light source generating light. In
the specification, the optical diode 200A includes a light source
generating light and/or all kinds of devices, films and/or sheets
used to treat light.
[0078] The optical diode 200A may include, for example, at least
one optical member 200a selected from a light guide plate, a
diffuser sheet, a brightness enhancement film, a prism film, a lens
film, a polarizing film, a reflective film, a viewing angle
compensation film, a retardation film and a protective film for
protecting these components. In addition, the optical diode 200A
may be selected from a light source assembly further including a
light source 240 in the optical member 200a. Here, a particular
shape of the light source assembly is not specifically limited, and
may be selected from conventional direct type and edge type light
source assemblies. For example, as the optical diode 200A, the
light source assembly may include a backlight unit (BLU)
conventionally used in an LCD device.
[0079] In FIGS. 3 and 4, as the backward diode 200, the optical
diode 200A having a multi-layer structure is shown. Particularly,
as the backward diode 200, the optical diode 200A including a
plurality of optical members 200a is shown in FIG. 3, and an
optical diode 200A including a plurality of optical members 200a
and a light source 240 is shown in FIG. 4.
[0080] Referring to FIG. 3, the optical diode 200A may include, as
an optical member 200a, a light guide plate 210 converting a point
light source emitted from a light source into a surface light
source; and a diffuser sheet 220 formed on the light guide plate
210 and diffusing light generated from the light guide plate 210.
In addition, the optical diode 200A may further include a
brightness enhancement film 230 formed on the diffuser sheet 220.
In addition, such an optical member 200a may be formed alone or in
a combination of at least two thereof. In FIG. 3, the brightness
enhancement film 230 is formed in a bilayer structure. Such an
optical diode 200A is, as shown in FIG. 3, packaged by a packaging
film 300, and equipped on a bottom surface of the display panel
100. Here, in FIG. 3, the light source providing light to the light
guide plate 210 is not shown, but the light source may be, for
example, separately equipped at an outside, and provide light to
the light guide plate 210.
[0081] In addition, referring to FIG. 4, as the backward diode 200,
the optical diode 220A may include an optical member 200a and a
light source 240. In addition, these may be assembled, and then
packaged by a packaging film 300. Particularly, the optical diode
200A is a light source assembly including the light source 240, and
includes at least one light source 240 and an optical member 200a
formed on the optical source 240. A plurality of the optical
members 200a may be included, and each of the optical members 200a
may include a light guide plate 210 converting a point light source
emitted from the light source 240 into a surface light source; and
a diffuser sheet 220 formed on the light guide plate 210 and
diffusing light generated from the light guide plate 210. In
addition, as shown in FIG. 4, the optical diode 200A may further
include a brightness enhancement film 230 formed on the diffuser
sheet 220.
[0082] In the present application, the light source 240 may emit
light without specific limitation. The light source 240 may
include, for example, a light emitting diode (LED). The light
source 240 may include a plurality of LEDs and a case in which the
LEDs are built according to an exemplary embodiment.
[0083] The packaging film 300 packages the above-described backward
diode 200, for example, the optical diode 200A. Here, the light
source 240 may not be packaged by the packaging film 300 as shown
in FIG. 3, or may be packaged along with the optical member 200a as
shown in FIG. 4.
[0084] The packaging film 300 includes a first region 310, and a
second region 320 extending from the first region 310. Here, the
first region 310 corresponds to a top surface 201 of the backward
diode 200, and the second region 320 corresponds to a side surface
202 of the backward diode 200. The packaging film 300 may further
include a third region 330 to obtain high fixing strength of the
backward diode 200. The third region 330 extends from the second
region 320, and corresponds to a bottom surface 203 of the backward
diode 200. In FIGS. 5 to 9, exemplary embodiments of the packaging
film 300 are shown.
[0085] Among the regions 310, 320 and 330 of the packaging film
300, at least the first region 310 and the second region 320 may
have areas which are equal or similar to a part corresponding to
the backward diode 200. For example, the area of the first region
210 may be equal or similar to that of the top surface 210 (refer
to FIG. 2) of the backward diode 200, and the area of the second
region 220 may be equal or similar to that of the side surface 202
(refer to FIG. 2) of the backward diode 200.
[0086] In addition, at least two second regions 320 may be
included. For example, two to four second regions 320 are included.
That is, the second region 320 may extend from the first region
310, and be formed on at least two of the four surfaces of the
first region 310. In addition, for example, two to four third
regions 330 are included, which may be the same as the number of
the second regions 320. For example, in FIG. 5, three of the second
regions 320 are formed, and the same number of the third regions
330 is formed.
[0087] In the present application, the packaging film 300 may be
any one further including the first region 310 and the second
region 320 as shown above, and preferably the third region 330
without limitation. In addition, the regions 310, 320 and 330 may
be formed in one process. The packaging film 300 may be formed, for
example, by cutting one sheet of film to have three regions 310,
320 and 330, thereby forming the regions 310, 320 and 330 in one
process.
[0088] The packaging film 300 may be selected from resin films, and
a kind of the resin film is not limited. The packaging film 300 may
be, for example, a film including at least one resin selected from
a polycarbonate (PC)-based resin, a polyester-based resin, a
polyolefin-based resin, a cyclo-olefin polymer (COP)-based resin,
an acrylic resin, a urethane-based resin, an epoxy-based resin, a
polyamide-based resin, a cellulose-based resin, a nylon-based resin
and a derivative thereof. Particularly, the packaging film 300 may
be, but is not limited to, a PC film, a polyethyleneterephthalate
(PET) film, a polyethylenenaphthalate (PEN) film, a
polybutyleneterephthalate (PBT) film, a polybutylenenaphthalate
(PBN) film, a polyethylene (PE) film, a polypropylene (PP) film, a
cyclic PE film, a cyclic PP film, an acrylic film, a triacetyl
cellulose (TAC) film and/or a nylon film. In addition, the listed
films may be stretched or non-stretched. The packaging film 300 is
preferably a non-stretched PC film or a non-stretched PET film.
[0089] The packaging film 300 may have light transmittance. In
addition, the packaging film 300 may have optical properties
including light polarizing, concentrating and/or diffusing
properties as needed, and in some cases, may have isotropy. At
least the first region 310 can have such characteristics. In this
case, the first region can be useful in packaging of the optical
diode 200A.
[0090] In the present application, isotropy means that the film
does not have retardation, or only has an insignificant retardation
to such an extent that does not have a substantial influence on a
phase of light penetrating the film.
[0091] The packaging film 300 may have an in-plane retardation
(R.sub.in) of 30 nm or less according to the first embodiment of
the present application. When the in-plane retardation (R.sub.in)
exceeds 30 nm, it can have an influence on a phase of light
penetrating the film 300. The packaging film 300 may have, for
example, an in-plane retardation (R.sub.in) calculated by Equation
1 of 30 nm or less, 25 nm or less, or 10 nm or less, and
particularly, for example, 0 to 25 nm, 0 to 10 nm, 0.1 to 5 nm, 0.2
to 3 nm, or 0.5 to 2 nm.
[0092] In addition, the packaging film 300 may have a
thickness-direction retardation (R.sub.th) of 35 nm or less
according to the second embodiment of the present application. When
the thickness-direction retardation (R.sub.th) exceeds 35 nm, it
can have an influence on a phase of light penetrating the film 300.
The packaging film 300 may have, for example, a thickness-direction
retardation (R.sub.th) calculated by Equation 2 of 35 nm or less,
30 nm or less, 20 nm or less, or 10 nm or less, and particularly,
for example, 0 to 30 nm, 0 to 20 nm, 0 to 10 nm, 0.1 to 5 nm, or
0.2 to 3 nm. In the present application, the retardations R.sub.in
and R.sub.th have absolute values.
R.sub.in=d.times.(nx-ny) [Equation 1]
[0093] In Equation 1, R.sub.in is an in-plane retardation, d is a
thickness of the packaging film 300, nx is a refractive index in a
slow axis direction of the packaging film 300 with respect to light
with a wavelength of 400 to 600 nm, and ny is a refractive index in
a fast axis direction of the packaging film 300 with respect to a
wavelength of 400 to 600 nm.
R.sub.th=d.times.(ny-nz) [Equation 2]
[0094] In Equation 2, Rth is thickness-direction retardation, d is
a thickness of the packaging film 300, ny is a refractive index in
a fast axis direction of the packaging film 300 with respect to
light with a wavelength of 400 to 600 nm, and nz is a refractive
index in a thickness direction of the packaging film 300 with
respect to light with a wavelength of 400 to 600 nm.
[0095] The packaging film 300 may be selected from, for example, a
non-stretched PC-based film, a non-stretched polyester-based film,
a non-stretched acrylic film, a non-stretched TAC-based film and/or
a non-stretched cyclic polyolefin-based film to satisfy such
retardation.
[0096] During packaging of the backward diode 200, the regions 310,
320 and 330 are bent at boundary lines C1 and C2. In the drawings,
the boundary lines C1 and C2 between the areas 310, 320 and 330 are
represented by dotted lines. Here, the boundary lines C1 and C2 are
represented for convenience of descriptions, and thus may or may
not actually be visible on the packaging film 300.
[0097] To package the backward diode 200 using the packaging film
300, for example, first, the first region 310 is placed to
correspond to a top surface 201 of the backward diode 200, and the
second region 320 is placed to correspond to a side surface 202 of
the backward diode 200 by bending the second region 320 on the
first boundary line C1. In addition, when the third region 330 is
further included, the third region 330 is placed to correspond to
the bottom surface 203 of the backward diode 200 by bending the
third region 330 on the second boundary line C2 before
packaging.
[0098] According to an exemplary embodiment, the packaging film 300
and the backward diode 200 may have adhesive strength to each
other. The adhesive strength may be present, for example, at a
contact interface between the packaging film 300 and the backward
diode 200. A method of adhering the packaging film 300 to the
backward diode 200 is not specifically limited, and may be
performed, for example, by applying a thermal and/or optical
laminating method. For example, the packaging film 300 may be fused
to the backward diode 200 by applying heat or radiating light to
the packaging film 300. Here, in the packaging film 300, at least
one selected from the second region 320 and the third region 330
may have adhesive strength to the backward diode 200. During
adhesion through lamination, conditions for radiating heat or light
may be suitably selected according to a kind of the packaging film
300, but the present application is not specifically limited
thereto.
[0099] In another embodiment of the present application, the
packaging film 300 and the backward diode 200 may have adhesive
strength therebetween through a separate adhesive means. The
adhesive means may be, for example, a pressure-sensitive adhesive
layer (not shown) formed between the packaging film 300 and the
backward diode 200. To discriminate such a pressure-sensitive
adhesive layer from a pressure-sensitive adhesive layer 400 formed
between the packaging film 300 and the display panel 100, the
pressure-sensitive adhesive layer is referred to as a second
pressure-sensitive adhesive layer.
[0100] The second pressure-sensitive adhesive layer is preferably
formed at a contact interface between the packaging film 300 and
the backward diode 200 to provide adhesive strength therebetween.
Such a second pressure-sensitive adhesive layer may be coated on
the packaging film 300 and/or the backward diode 200. For example,
the second pressure-sensitive adhesive layer may be formed on at
least one selected from the second region 320 and the third region
330. Particularly, the second pressure-sensitive adhesive layer may
be formed on an inner surface of at least the second region 320
and/or the third region 330 of the regions 310, 320 and 330 of the
packaging film 300.
[0101] As described above, the packaging film 300 and the backward
diode 200 may be adhered between at least the second region 320 and
the side surface 202 and/or between the third region 330 and the
bottom surface 203 through fusion by heat and/or light or adhesion
using the second pressure-sensitive adhesive layer.
[0102] In addition, the adhesive means may be, for example, a
double-sided or single-sided pressure-sensitive adhesive tape.
Here, the double-sided pressure-sensitive adhesive tape may be
interposed between the packaging film 300 and the backward diode
200. Particularly, the double-sided pressure-sensitive adhesive
tape may be interposed between the second region 320 and the side
surface 202, and/or between the third region 330 and the bottom
surface 203. In addition, for example, an outer surface of the
third region 330 may be taped with the single-sided
pressure-sensitive adhesive tape to provide binding strength to the
backward diode 200.
[0103] Referring to FIGS. 5 and 6, according to a third embodiment
of the present application, a notch part 350 may be formed on a
boundary line C1 between the first region 310 and the second region
320. In addition, when the packaging film 300 further includes a
third region 330, the notch part 350 may also be formed on a
boundary line C2 between the second region 320 and the third region
330. FIG. 6 is a cross-sectional view taken along line A-A' of FIG.
5.
[0104] In the present application, the notch part 350 may be any
one processed to easily bend the second region 320 and the third
region 330 on the boundary lines C1 and C2, respectively. The notch
part 350 may be formed through, for example, notch treatment
capable of generating a thickness difference between the boundary
lines C1 and C2. Particularly, the notch part 350 may be selected
from imprinted parts formed by pressing the boundary lines C1 and
C2, and half-cut parts formed by half-cutting the boundary lines C1
and C2. In the present application, the "half" does not mean only a
half of the thickness of the packaging film 300.
[0105] The notch part 350 may be formed to a depth of, for example,
1/3 to 2/3 of the thickness of the packaging film 300 through
folding line imprinting or half-cutting. Here, when the depth of
the notch part 350 is less than 1/3, for example, in some cases,
breakage may occur. When the depth is more than 2/3, it may be
somewhat difficult to bend.
[0106] In addition, the notch part 350 may be continuously formed
along the boundary lines C1 and C2, or discontinuously formed at a
predetermined interval. That is, the notch part 350 may be
discontinuously formed by a dotted line representing the boundary
lines C1 and C2. In another example, the notch part 350 may be
selected from a plurality of micropores perforated at a
predetermined interval along the boundary lines C1 and C2, and in
the present application, the notch part 350 may be, but is not
specifically limited to, any one processed to easily bend the
regions 310, 320 and 330 on each boundary line C1 or C2 as
described above.
[0107] In addition, the regions 310, 320 and 330 may have a bending
strength of, for example, 1.0 to 10.0 gf on each boundary line C1
or C2. Such bending strength may be set by the notch part 350.
Here, when the bending strength is less than 1.0 gf, the regions
310, 320 and 330 are easily bent on the boundary line C1 or C2 or
overlapped, and thus can be difficult to handle. In addition, when
the bending strength is more than 10.0 gf, a bending process may
not be facilitated. Considering these, the regions 310, 320 and 330
may have a bending strength of, for example, 2 to 8 or 3 to 6 gf on
each boundary line C1 or C2. The bending strength may be, for
example, a value measured according to ASTM D790.
[0108] The thickness of the packaging film 300 is not specifically
limited. The thickness of the packaging film 300 may be variously
set in consideration of supporting strength, bending processability
of each region 310, 320 or 330, handleability in packaging, and/or
thinning of the film 300.
[0109] According to a fourth embodiment of the present application,
the thickness of the packaging film 300 may satisfy an area of the
first region 310 and Equation 3.
T [.mu.m]=100.times.S [m.sup.2]+a [Equation 3]
[0110] In Equation 3, T is a thickness (unit: .mu.m) of the
packaging film 300, S is an area (width.times.length, unit:
m.sup.2) of the first region 310, and a is a number from 15 to 130.
Here, a includes a decimal as well as an integer.
[0111] When the thickness of the packaging film 300 satisfies
Equation 3, it is advantageous in terms of the supporting strength;
the bending processability of each region 310, 320, or 330;
handleability in packaging, and/or the thinning of the film
300.
[0112] In Equation 3, S is an area of the first region 310, which
may also be an area of the top surface of the backward diode 200
corresponding to the first region 310. In another example, S of
Equation 3 may be an area of a top surface of the display panel
100. Generally, a display device such as a TV or a monitor may be
inclined toward a wall at an angle of approximately 10 degrees when
equipped on the wall. Here, when the thickness of the packaging
film 300 is too small to satisfy Equation 3, the packaging film 300
may droop or project forward due to a low supporting strength. In
addition, when the thickness of the packaging film 300 is too large
to satisfy Equation 3, the bending processability of each region
310, 320 or 330 may decrease due to unnecessarily high strength,
and a separated part may be generated after bending, which may be
disadvantageous in terms of thinning of the film. Considering this,
it is preferable that the thickness of the packaging film 300
satisfies Equation 3.
[0113] The thickness of the packaging film 300 may vary depending
on the area of the first region 310, and the thickness may be, for
example, in the range from approximately 20 to 500 .mu.m, 30 to 400
.mu.m, or 35 to 200 .mu.m.
[0114] In addition, according to a fifth embodiment of the present
application, the packaging film 300 may have at least one physical
property selected from (a) a tensile modulus of 1,200 MPa or more,
(b) a tensile strength of 40 MPa, and (c) an elongation of 20%.
When the packaging film 300 has such a physical property, the
backward diode 200 may be packaged and supported well.
[0115] Although this differs depending on the backward diode 200,
for example, when a tensile modulus is less than 1,200 MPa or a
tensile strength is less than 40 MPa, supporting strength of the
backward diode 200 may become insignificant. The upper limits of
the tensile modulus and the tensile strength are not specifically
limited. Particularly, the packaging film 300 may have a tensile
modulus of 1,200 to 5,000 MPa, 1,500 to 4,000 MPa, 1,800 to 3,000
MPa, 1,900 to 2,500 MPa, or 2,000 to 2,400 MPa. In addition, the
packaging film 300 may have, for example, a tensile strength of 40
to 200 MPa, 45 to 150 MPa, 50 to 100 MPa, or 55 to 75 MPa.
Moreover, when an elongation is less than 20%, for example, the
handleability in packaging may be degraded. The upper limit of the
elongation is not limited, but in consideration of the supporting
strength of the backward diode 200, for example, the elongation may
be 200% or less. Considering this, the packaging film 300 may have,
for example, an elongation of 20% to 200%, 30% to 180%, 50% to
180%, or 80% to 150%.
[0116] Methods of measuring the tensile modulus, tensile strength
and elongation are not limited. For example, the tensile modulus
and the tensile strength may be values measured by a tensile tester
generally used in the film manufacturing field. In addition, the
elongation may be a value calculated through an equation
[Elongation (%)=(A-B)/A.times.100] by setting an initial gauge
length of the film 300 as A and a gauge length at a broken time
after elongation as B in a tensile tester.
[0117] In addition, the packaging film 300 preferably has a small
strain for high supporting strength, fixing strength and/or
durability. The packaging film 300 may have a strain (E) obtained
by Equation 4 of 5% or less according to a sixth embodiment of the
present application.
E (%)=[(L2-L1)/L1].times.100 [Equation 4]
[0118] In Equation 4, L1 is an initial length (width or length) of
the packaging film 300, and L2 is an extending length of the
packaging film 300 after being maintained for 24 hours while
applying a load of 3 kg at 80.degree. C.
[0119] As described above, the display device may be inclined
toward a wall at an angle of approximately 10 degrees. Here, when
the strain (E) of the packaging film 300 according to Equation 4 is
more than 5%, the packaging film may droop or project forward due
to a load of the display device. Particularly, the packaging film
300 may have a strain (E) of 4% or less, 3.5% or less, 3.2% or
less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, or 1% or
less. It is preferable that the strain (E) of the packaging film
300 be closer to 0.
[0120] In one example, the packaging film 300 may be selected from
films which are elongated approximately 2 mm or less in a length or
width direction, when maintained at 80.degree. C. under a load of 3
kg for 24 hours, based on a size of 60 mm.times.25 mm
(width.times.length).
[0121] Moreover, the packaging film 300 may have folding endurance,
when a folding number (MIT) measured by a test defined by JIS P8115
is, for example, 200 times or more, 300 times or more, or 400 times
or more.
[0122] In addition, referring to FIG. 5, according to a seventh
embodiment of the present application, the third region 330 may
have an overlap prevented part 360. That is, the overlap preventing
part 360 may be formed in the third region 330 to prevent overlap
between adjacent third regions 330 when the third region 330 is
bent to be adhered to the bottom surface 203 of the backward diode
200.
[0123] The overlap prevented part 360 may be selected from a
notched part 361 cut, for example, at a predetermined angle
(.theta.). Here, the angle (.theta.) of the notched part 361 may
be, for example, 15 to 85 degrees or 30 to 60 degrees.
Particularly, the angle (.theta.) of the notched part 361 may be 30
degrees or more, or 45 degrees of more. Due to such a notched part
361, the overlapping of the adjacent third regions 330 may be
prevented. In the present application, as shown in FIG. 5, the
angle (.theta.) of the notched part 361 is an angle of incline
between an extension line a and a side surface of the third region
360 based on the extension line (a) extending in a straight line
direction in the second region 320.
[0124] FIG. 7 shows the overlap prevented part 360 according to
another embodiment. Referring to FIG. 7, the overlap prevented part
360 may be selected from cut parts 362 cut to a predetermined
length L and then removed. Here, the length L of the cut part 362
may be, for example, larger than or the same as a width (W.sub.330)
of the third region 330. The overlapping of the adjacent third
regions 330 may be prevented by such a cut part 362.
[0125] According to an exemplary embodiment, among the regions 310,
320 and 330, at least the first region 310 may have light
transmittance (transparency). The first region 310 may have, for
example, a light transmittance of 80% or more, particularly, 90% or
more. In this case, it is advantageous to package the optical diode
200A.
[0126] In addition, according to an eighth embodiment of the
present application, among the second and third regions 320 and
330, at least the second region 320 may have light impermeability.
That is, since the second region 320 has light transmittance, light
leakage to the side surface thereof may be prevented. The second
region 320 may have a light impermeability of, for example, 10% or
less, 5% or less, 1% or less, 0.1% or less, or 0%. In the present
application, the light impermeability includes a light shielding
property of blocking light and/or a light reflecting property of
reflecting light. For such light impermeability, at least the
second region 320 may include, for example, at least one light
leakage preventing layer selected from a light shielding layer and
a reflective layer. In addition, the third region 330 may also
selectively have light impermeability.
[0127] The light shielding layer may be formed, for example, by
coating a light shielding material on the second region 320. In
addition, the reflective layer may be formed by, for example, a
reflective material may be coated on the second region 320. The
term "coating" used herein includes a coating method such as
printing or deposition, in addition to, general coating such as bar
coating or spray coating.
[0128] Materials constituting the light shielding or reflective
layer are not specifically limited. A light shielding material may
be a material exhibiting a color such as black, and particularly,
an inorganic or organic material selected from carbon black,
graphite, iron oxide, an azo-based pigment and/or a
phthalocyanine-based pigment. In addition, the reflective material
may be, for example, a metal or metal oxide selected from aluminum,
titanium, silica, alumina and/or titania. Such light shielding and
reflective materials may be blended with a binder and/or solvent
and coated by printing. In addition, the metal or metal oxide for
reflectivity may be coated through deposition.
[0129] Referring to FIG. 8, according to a ninth embodiment of the
present application, a light impermeable part 314 may be formed at
an edge of the first region 310. Particularly, as shown in FIG. 8,
the first region 310 may have a main transparent region 312, and
also have a light impermeable part 314 formed along the edge
thereof. The light impermeable part 314 may have light
impermeability (light leakage preventability). For example, the
light impermeable part 314 may be selected from a printed layer
formed by printing a light impermeable paint. Moreover, the light
impermeable part 314 may be selected from the above-described light
shielding and reflective layers. For example, the light impermeable
part 314 may be formed by coating a light shielding material
(colored material) such as an inorganic or organic material
selected from carbon black, graphite, iron oxide, an azo-based
pigment and a phthalocyanine-based pigment.
[0130] When the light impermeable part 314 is formed at the edge of
the first region 310 as described above, light leakage to the side
surface may be completely prevented. Although the light leakage to
the side surface is prevented due to the light impermeability of
the second region 320, it may occur and there may be allowance in
some cases, for example, if the packaging film 300 is not exactly
bent on the boundary lines C1 and C2. In addition, during the
packaging of the packaging film 300, the first region 310 is
lopsided, and thus the edge of the first region 310 is located on a
side surface of the optical diode 200A, thereby generating light
leakage to the side surface. In such a case, the light leakage to
the side surface may be completely prevented since light is
shielded by the light impermeable part 314.
[0131] A width (W.sub.314) and a thickness of the light impermeable
part 314 are not specifically limited. The width (W.sub.314) may
be, for example, 0.01 mm or more. Here, the width (W.sub.314) is
less than 0.01 mm, a function of preventing allowance may be
insignificant. The upper limit of the width is not specifically
limited, but when the width (W.sub.314) is too large, a screen may
be excessively covered, and thus the width is preferably, for
example, 10 mm or less. In consideration of this, the light
impermeable part 314 may have a width (W.sub.314) of, for example,
0.02 to 5 mm, and particularly, for example, 0.03 to 3 mm. In
addition, an area of the light impermeable part 314 may be, for
example, 0.01 to 5%, and particularly, 0.5 to 2% of a total area of
the first region. In addition, a thickness of the light impermeable
part 314 may be, for example, 200 .mu.m or less, and particularly,
for example, 0.01 to 200 .mu.m, or 0.02 to 100 .mu.m.
[0132] Referring to FIG. 9, according to a tenth embodiment of the
present application, the first region 310 may include a projected
part 315 in which the second region 320 does not extend.
Particularly, as shown in FIG. 9, the second region 320 may extend
from the first region 310, not from a vertex 310a thereof, to have
a step difference 316, and thus the first region 310 may include a
projecting part 315. That is, the vertex 310a of the first region
310 may be projected.
[0133] When the projected part 315 is included as described above,
that is, when the projected part 315 in which the second region 320
does not extend from the first region 310 is included, stress
caused in the bending of the second region 320 may be prevented.
Although this depends on mechanical properties or thickness of the
packaging film 300, as shown in FIG. 5, when there is no projected
part 315 formed by projecting the vertex 310a, a part around the
vertex 310a of the first region 310 may be separated by applying
stress when the second region 320 is bent. However, when the
projected part 315 is included, the separation phenomenon may be
prevented.
[0134] Referring to FIGS. 2 to 4, the packaging film 300 is adhered
and fixed to the display panel 100 through the pressure-sensitive
adhesive layer 400.
[0135] According to an eleventh embodiment of the present
application, adhesive surface treatment may be performed on a top
surface of the packaging film 300. Particularly, an adhesive
surface treated part may be formed on a top surface of at least the
first region 310, that is, a surface (an upper surface in the
drawing) in contact with the pressure-sensitive adhesive layer 400.
In the present application, the adhesive surface treatment is not
limited as long as it can improve adhesive strength between the
packaging film 300 and the pressure-sensitive adhesive layer 400.
Due to such adhesive surface treatment, adhesive strength is
improved at a contact interface between the packaging film 300 and
the pressure-sensitive adhesive layer 400, and thus fixing strength
between the display panel 100 and the packaging film 300 is
increased.
[0136] The adhesive surface treatment may be, at least one selected
from, for example, corona treatment and primer treatment. Methods
for the corona treatment and the primer treatment are not be
specifically limited, and may be arbitrary known methods for
improving adhesive strength in film processing. For example, the
primer treatment may be a method of forming a primer layer by
coating an acryl-based, urethane-based, or epoxy-based primer. In
addition, the primer layer may have a thickness of, for example,
0.01 to 50 .mu.m.
[0137] In addition, according to a twelfth embodiment of the
present application, a bottom surface of the packaging film 300 may
have a ribbed surface. Particularly, a ribbed surface may be formed
on a bottom surface of the first region 310, that is, a surface (a
lower surface in the drawing) in contact with the backward diode
200. Due to such a ribbed surface, after packaging, fusion between
the first region 310 and the backward diode 200 may be prevented.
More particularly, referring to FIG. 3, the fusion between a bottom
surface (lower surface in the drawing) of the first region 310 and
a top surface (upper surface in the drawing) of a brightness
enhancement film 230 may be prevented.
[0138] The ribbed surface may be formed by various methods, for
example, a mat treatment and a haze treatment. By such a treatment,
the ribbed surface may have a roughness, for example, an RMS
roughness of, for example, 0.1 .mu.m or more, 0.5 .mu.m or more, or
1.0 .mu.m or more, and preferably, for example, approximately 0.1
to 10 .mu.m, 0.5 to 8 .mu.m, or 1.0 to 5 .mu.m. In addition, the
ribbed surface may have a haze of 80% or less, or 70% or less, and
preferably, approximately 40% to 80% or 50% to 70%.
[0139] In addition, according to a case, the ribbed surface may be
a high-hardness surface having high hardness, for example, pencil
hardness of 1 B or more, or 2 B or more, and preferably,
approximately 1 B to 4 B or 2 B to 4 B.
[0140] When the ribbed surface has a roughness (RMS roughness)
and/or a pencil hardness in the above-exemplified ranges, the
fusion between the first region 310 and the backward diode 200 may
be effectively prevented.
[0141] In addition, the ribbed surface may be formed using, for
example, a resin layer. For example, in the process of forming a
resin layer, the ribbed surface may be formed by an imprinting
process or a method of transferring a ribbed cast, or a method of
including beads which can form ribs in a resin layer having a
suitable thickness.
[0142] The resin layer may include, for example, a room
temperature-curable, moisture-curable, heat-curable or photocurable
resin composition in a cured state. In one example, the resin layer
may include a heat-curable or photocurable resin composition, or
include a photocurable resin composition in a cured state. Here,
the room temperature-curable, moisture-curable, heat-curable or
photocurable resin composition may refer to a resin composition
cured at room temperature, or in a suitable humidity, by applying
heat or radiating active energy rays.
[0143] For example, the resin composition may include an acryl
compound, an epoxy compound, a urethane compound, a phenol compound
or a polyester compound as a main material. Here, the "compound"
may be a monomer, oligomer or polymer compound.
[0144] In another example, as the resin composition, an acrylic
resin composition having an excellent optical property such as
transparency and excellent resistance to yellowing, for example, a
photocurable acrylic resin composition, may be used. The
photocurable acrylic composition may include, for example, an
active energy ray-polymerizable polymer component and a reactive
monomer for dilution.
[0145] Here, as the polymer component, a component known as a
so-called active energy ray-polymerizable oligomer such as urethane
acrylate, epoxy acrylate, ether acrylate or ester acrylate, or a
polymerized product of a mixture including a monomer such as a
(meth)acrylic acid ester monomer may be used. Here, as the
(meth)acrylic acid ester monomer, an alkyl (meth)acrylate, a
(meth)acrylate having an aromatic group, a heterocyclic
(meth)acrylate or an alkoxy (meth)acrylate may be used.
[0146] As the reactive monomer for dilution which can be included
in the photocurable acrylic composition, a monomer having one or at
least two photocurable functional groups, for example, an acryloyl
group, a methacryloyl group, etc. may be used. As the reactive
monomer for dilution, for example, the (meth)acrylic acid ester
monomer or a multifunctional acrylate may be used.
[0147] Selection of the component to prepare the photocurable
acrylic composition or a ratio of blending the selected component
is not specifically limited, and may be controlled in consideration
of hardness and other physical properties of a desired resin
layer.
[0148] Ribs may be formed in the resin layer by a suitable method
in the process of forming a resin layer using the resin
composition, or a ribbed surface may be embodied by including beads
in the resin layer. Here, when beads are included, the beads may
have a refractive index different from or substantially equal to
that of the resin layer. When the beads have a refractive index
different from that of the resin layer, a subsidiary effect of
inducing light diffusion through the resin layer may also be
obtained.
[0149] A shape of the beads included in the resin layer may be, but
is not specifically limited to, for example, a spherical, oval,
polygonal, or amorphous shape, or another shape. As a particular
kind of beads, various inorganic or organic beads may be used. As
inorganic beads, silica, amorphous titania, amorphous zirconia,
indium oxide, alumina, amorphous zinc oxide, amorphous cerium
oxide, barium oxide, calcium carbonate, amorphous barium titanate
or barium sulfate may be used, and as organic beads, particles
including a crosslinked or non-crosslinked product of an organic
material such as an acrylic resin, a styrene resin, a urethane
resin, a melamine resin, a benzoguanamine resin, an epoxy resin or
a silicon resin may be used, but the present application is not
limited thereto.
[0150] In addition, a method of forming a ribbed surface in the
resin layer without using beads is not specifically limited. For
example, the ribbed surface may be embodied by curing the resin
composition in a state in which a coating layer of the resin
composition is in contact with a mold having a desired ribbed
structure, or by an imprinting method.
[0151] In some cases, a resin composition is prepared for the resin
layer to have high hardness, and allows the resin layer to serve as
a high-hardness layer. In this case, the resin layer may be
controlled to have hardness, for example, pencil hardness in the
above-described range.
[0152] In the present application, the pressure-sensitive adhesive
layer 400 may be formed between the display panel 100 and the
packaging film 300 to adhere and fix. The pressure-sensitive
adhesive layer 400 may be coated on the packaging film 300, that
is, the first region 310 of the packaging film 300. In addition,
the pressure-sensitive adhesive layer 400 may be coated on the
display panel 100, for example, on a lower polarizing plate 160. In
another example, the pressure-sensitive adhesive layer 400 may be
formed by a transferring method. That is, the pressure-sensitive
adhesive layer 400 may be formed by being coated on a separate
releasing film, and being transferred onto the display panel 100 or
the packaging film 300. The pressure-sensitive adhesive layer 400
may have a light transmittance of, for example, 80% or more.
[0153] The pressure-sensitive adhesive layer 400 may be formed of a
pressure-sensitive adhesive composition. Here, the
pressure-sensitive adhesive composition is as follows. The
pressure-sensitive adhesive composition may also be applied to a
second pressure-sensitive adhesive layer, as well as the
pressure-sensitive adhesive layer 400. Particularly, the
pressure-sensitive adhesive composition which will be described
below may also be applied to the second pressure-sensitive adhesive
layer formed between the packaging film 300 and the backward diode
200 to provide adhesive strength therebetween, as well as the
pressure-sensitive adhesive layer 400 formed between the display
panel 100 and the packaging film 300.
[0154] In the present application, the pressure-sensitive adhesive
composition includes, for example, a photocurable and/or
heat-curable type. The pressure-sensitive adhesive composition may
include, for example, a monomer and/or polymer component. The
monomer and polymer components may form a base of the
pressure-sensitive adhesive layer through curing. The term
"polymer" used herein refers to a compound prepared by polymerizing
at least two monomers, and also includes, for example, a component
generally called an oligomer. In the field of preparing
pressure-sensitive adhesives, various monomer and polymer
components used to prepare the pressure-sensitive adhesive
compositions are known, and such components are not limited. The
monomer and polymer include, for example, acryl-based,
urethane-based, and/or epoxy-based monomers and polymers.
[0155] In the heat-curable pressure-sensitive adhesive composition,
the monomer and polymer components may be, for example, acrylic
monomers and polymers each having a crosslinkable functional group.
The acrylic polymer may be, for example, a polymer having a weight
average molecular weight (Mw) of approximately 1,500,000 or more,
and a glass transition temperature of approximately -24 to
-16.degree. C. A specific kind of the polymer may be, but is not
specifically limited to, a polymer conventionally used as a
pressure-sensitive adhesive resin, for example, an acrylic polymer
including a (meth)acrylic acid alkyl ester and a copolymerizable
monomer capable of providing a crosslinkable functional group on a
side chain or terminal end of the polymer. Here, as a particular
example of the (meth)acrylic acid alkyl ester, an alkyl
(meth)acrylate including an alkyl group having 1 to 14 carbon atoms
such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl
(meth)acrylate or ethylhexyl (meth)acrylate may be used. In
addition, as the polymer monomer, a monomer simultaneously having a
copolymer functional group such as an ethylene-like double bond and
a crosslinkable functional group such as a hydroxyl group, a
carboxyl group, an epoxy group, an isocyanate group or an amide
group may be used.
[0156] A weight ratio of each monomer included in the acrylic
polymer having a crosslinkable functional group is not specifically
limited, and may be controlled in consideration of initial
pressure-sensitive adhesive strength, adhesive strength and
cohesive strength of a desired pressure-sensitive adhesive layer.
In addition, in the acrylic polymer, when needed, various
copolymerizable monomers, as well as the above-described monomers,
may also be included in a polymerized state. The polymer may be
prepared by a general polymerization method in the art, for
example, solution polymerization, photo polymerization, bulk
polymerization, suspension polymerization, or emulsion
polymerization.
[0157] The photocurable pressure-sensitive adhesive composition may
further include a multifunctional crosslinking agent that can
crosslink the polymer with an acrylic polymer. In this case, a
particular kind of the crosslinking agent is not specifically
limited, and may be, for example, a known crosslinking agent such
as an isocyanate-based crosslinking agent, an epoxy-based
crosslinking agent, an aziridine-based crosslinking agent and a
metal chelate-based crosslinking agent. In addition, a ratio of the
crosslinking agent in the composition is not specifically limited,
and may be suitably controlled in consideration of desired cohesive
strength.
[0158] The pressure-sensitive adhesive composition may be a
photocurable pressure-sensitive adhesive composition according to
one embodiment. The term "photocurable pressure-sensitive adhesive
composition" used herein refers to a composition converted into a
pressure-sensitive adhesive by inducing a curing process by light
radiation, that is, radiation of electromagnetic waves. Here, the
"electromagnetic waves" refer to microwaves, IR rays, UV rays, X
rays, .gamma. rays, or particle beams such as a particle beams,
proton beams, neutron beams and electron beams, and conventionally
UV rays or electron beams.
[0159] In the photocurable pressure-sensitive adhesive composition,
the monomer and polymer component may include a photocurable
oligomer and/or a reactive monomer for dilution. As the
photocurable oligomer, all kinds of oligomer components used in
preparation of a photocurable pressure-sensitive adhesive
composition such as a UV-curable oligomer component in the art may
be included. For example, the oligomer may be, but is not limited
to, a urethane acrylate prepared by reaction of a polyisocyanate
having at least two isocyanate groups in a molecule and a
hydroxyalkyl (meth)acrylate; an ester-based acrylate prepared by
dehydrating condensation of a polyester polyol and (meth)acrylic
acid; an ester-based urethane acrylate prepared by reaction of an
ester-based urethane resin prepared by reaction of a polyester
polyol, a polyisocyanate and a hydroxyalkyl acrylate; an
ester-based acrylate such as a polyalkyleneglycol di(meth)acrylate;
an ether-based urethane acrylate prepared by reaction of an
ether-based urethane resin prepared by reaction of a polyether
polyol, a polyisocyanate and a hydroxyalkyl (meth)acrylate; or an
epoxy acrylate prepared by an addition reaction of an epoxy resin
and (meth)acrylic acid.
[0160] As the reactive monomer for dilution, any monomer having a
reactive functional group such as a (meth)acryloyl group in a
molecular structure may be used without particular limitation. Such
a monomer may serve to control a viscosity of the composition and
embody pressure-sensitive adhesive strength after curing. Such a
monomer may be, but is not limited to, an alkyl (meth)acrylate; a
hydroxyl-group-containing monomer such as hydroxyethyl
(meth)acrylate, hydroxypropyl (meth)acrylate or hydroxybutyl
(meth)acrylate; a carboxylic acid-containing monomer such as
(meth)acrylic acid or beta-carboxyethyl (meth)acrylate; an
alkoxy-group-containing monomer such as 2-(2-ethoxyethoxyl)ethyl
(meth)acrylate; an aromatic-group-containing monomer such as benzyl
(meth)acrylate or phenoxyethyl (meth)acrylate; a
heterocyclic-residue-containing monomer such as tetrahydrofurfuryl
(meth)acrylate or (meth)acryloyl morpholine; or a multifunctional
acrylate.
[0161] Particular kinds and blending ratios of the photocurable
oligomer and the reactive monomer for dilution are not specifically
limited, and may be suitably selected in consideration of a
viscosity of a desired composition and a pressure-sensitive
adhesive property to be embodied after curing.
[0162] In another example of the photocurable pressure-sensitive
adhesive composition, the monomer or polymer component may be a
photocurable syrup. The photocurable syrup may be a monomer mixture
including a (meth)acrylic acid ester monomer such as an alkyl
(meth)acrylate, or a partial polymer thereof.
[0163] The (meth)acrylic acid ester included in the monomer mixture
may be, for example, an alkyl (meth)acrylate having a linear or
branched alkyl group having 1 to 14 carbon atoms such as methyl
(meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate,
isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl
(meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate,
hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl
(meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate,
isononyl (meth)acrylate, lauryl (meth)acrylate or tetradecyl
(meth)acrylate; a copolymerizable monomer capable of providing the
above-described crosslinkable functional group; or another
copolymerizable monomer, for example, the above-described oligomer
or reactive monomer for dilution.
[0164] When the pressure-sensitive adhesive composition includes a
partial polymer of the above-described monomer mixture as the
syrup, a polymerizing rate of the monomer mixture or a conversion
rate of the monomer is not specifically limited. For example, the
polymerizing rate or conversion rate may be controlled in
consideration of process efficiency or a desired pressure-sensitive
adhesive property.
[0165] As another example of the photocurable pressure-sensitive
adhesive composition, a pressure-sensitive adhesive composition
capable of forming a pressure-sensitive adhesive layer including a
so-called interpenetrating polymer network (hereinafter referred to
as "IPN") is used. The term "IPN" used herein may refer to a state
in which at least two crosslinked structures are present in a
pressure-sensitive adhesive layer, and in one example, the
crosslinked structures may be present in a state in which they are
entangled with, linked to or penetrating each other. When the
pressure-sensitive adhesive layer includes an IPN, the
pressure-sensitive adhesive layer may have excellent durability
under harsh conditions, and excellent workability or light leakage
preventability.
[0166] In the pressure-sensitive adhesive composition capable of
forming the pressure-sensitive adhesive layer including the IPN
structure, the polymer component may be an acrylic polymer. In this
case, as the acrylic polymer which can be used, an acrylic polymer
used in the above-described heat-curable pressure-sensitive
adhesive composition maybe used. The photocurable
pressure-sensitive adhesive composition may further include the
multifunctional crosslinking agent and the photocurable
multifunctional compound, described in the category of the
heat-curable pressure-sensitive adhesive composition, in addition
to the acrylic polymer. Here, the photocurable multifunctional
compound may mean a compound including at least two functional
groups capable of being polymerized by radiation of light. The
pressure-sensitive adhesive layer formed by such a composition may
include, for example, a crosslinked structure including the acrylic
polymer crosslinked by the multifunctional crosslinking agent and a
crosslinked structure including the polymerized multifunctional
compound.
[0167] As the photocurable multifunctional compound, for example, a
multifunctional acrylate may be used. The multifunctional acrylate
may be any compound having at least two (meth)acryloyl groups in a
molecule without limitation. For example, the multifunctional
acrylate may be a bifunctional acrylate such as 1,4-butanediol
di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentylglycol
di(meth)acrylate, polyethyleneglycol di(meth)acrylate,
neopentylglycol adipate di(meth)acrylate, hydroxypivalic acid
neopentylglycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate,
caprolactone-modified dicyclopentenyl di(meth)acrylate,
ethyleneoxide-modified di(meth)acrylate, di(meth)acryloxy ethyl
isocyanurate, allylated cyclohexyl di(meth)acrylate,
tricyclodecanedimethanol (meth)acrylate, dimethylol dicyclopentane
di(meth)acrylate, ethyleneoxide-modified hexahydrophthalic acid
di(meth)acrylate, tricyclodecane dimethanol(meth)acrylate,
neopentylglycol-modified trimethylpropane di(meth)acrylate,
adamantane di(meth)acrylate, or
9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorine; a trifunctional
acrylate such as trimethylolpropane tri(meth)acrylate,
dipentaerythritol tri(meth)acrylate, propionic acid-modified
dipentaerythritol tri(meth)acrylate, pentaerythritol
tri(meth)acrylate, propyleneoxide-modified trimethylolpropane
tri(meth)acrylate, trifunctional urethane (meth)acrylate, or
tris(meth)acryloxyethylisocyanurate; a tetrafunctional acrylate
such as diglycerin tetra(meth)acrylate or pentaerythritol
tetra(meth)acrylate; a pentafunctional acrylate such as propionic
acid-modified dipentaerythritol penta(meth)acrylate; or a
hexafunctional acrylate such as dipentaerythritol
hexa(meth)acrylate, caprolactone-modified dipentaerythritol
hexa(meth)acrylate, or urethane (meth)acrylate (e.g. a reaction
product of an isocyanate monomer and trimethylolpropane
tri(meth)acrylate). In some cases, the multifunctional acrylate may
be a photocurable oligomer known in the art, which may be any kind
of urethane acrylate, polycarbonate acrylate, polyester acrylate,
polyether acrylate or epoxy acrylate.
[0168] Ratios of the acrylic polymer, crosslinking agent and
photocurable multifunctional compound in the pressure-sensitive
adhesive composition are not specifically limited, and may be
controlled by physical properties of a desired pressure-sensitive
adhesive.
[0169] The pressure-sensitive adhesive composition may further
include a radical initiator such as a photoinitiator or a thermal
initiator, in addition to the components described above, and a
conventional photo radical initiator. As the photo radical
initiator, any one capable of generating radicals by radiation of
electromagnetic waves and initiating a curing reaction may be used
without specific limitation. A ratio of the radical initiator is
not specifically limited, either, and may be selected within a
range capable of inducing a suitable curing reaction of
photocurable components included in the composition.
[0170] In addition, the pressure-sensitive adhesive composition may
further include at least one additive selected from the group
consisting of a silane coupling agent, a pressure-sensitive
adhesion providing resin, an epoxy resin, a curing agent, a UV
stabilizer, an antioxidant, a coloring agent, a reinforcing agent,
a filler, a foaming agent, a surfactant, and a plasticizer as
needed.
[0171] A method of forming the pressure-sensitive adhesive layer
using such a pressure-sensitive adhesive composition is not
particularly limited. In the process of forming the
pressure-sensitive adhesive layer, a curing process may be
performed by application of heat and/or radiation of light, and the
curing process may be performed after the packaging film 300 is
adhered to an adherent by the pressure-sensitive adhesive layer,
that is, for example, the packaging film 300 is adhered to the
display panel 100. In addition, the application of heat and
radiation of light are not performed under specifically limited
conditions, for example, conditions capable of ensuring
characteristics of the desired pressure-sensitive adhesive layer.
The radiation of light may be performed using, for example, a means
such as a high pressure mercury lamp, an electrodeless lamp or a
xenon lamp. In addition, a luminescence in the radiation of light
may be controlled within a range of, for example, 50 to 2,000
mW/cm.sup.2, and a quantity of light may be controlled within a
range of 10 to 1,000 mJ/cm.sup.2, but the present application is
not limited thereto.
[0172] The pressure-sensitive adhesive layer 400 is formed at least
between the display panel 100 and the first region 310. Here, in
some cases, the pressure-sensitive adhesive layer 400 may need
resistance to external force.
[0173] For example, under a high temperature and/or high humidity,
a wave may be generated between the first and second regions 310
and 320 of the packaging film 300. More particularly, the first
region 310 is adhered and fixed to the pressure-sensitive adhesive
layer 400, and thus does not contract or expand, but the second
region 320 may contract or expand under a high temperature and/or
high humidity. Due to such contraction and expansion of the second
region 320, waves are generated between the first and second
regions 310 and 320, and stress may be generated at an edge of the
first region 310 due to the waves. Here, in some cases, a
separation phenomenon may occur between the first region 310 and
the pressure-sensitive adhesive layer 400.
[0174] In addition, although this depends on the display panel 100
and the backward diode 200, for example, when weights of the
display panel 100 and the backward diode 200 are large, the
pressure-sensitive adhesive layer 400 may be resistant to shearing
stress. That is, the pressure-sensitive adhesive layer 400 should
ensure cohesive strength for resisting shearing stress applied by a
load of the display panel 100 and the backward diode 200 not to be
detached. Considering this, the pressure-sensitive adhesive layer
400 may be selected from Examples 1 to 3 which will be described
below.
(1) First Example of Pressure-Sensitive Adhesive Layer
[0175] According to the first example, the pressure-sensitive
adhesive layer 400 may have a room temperature storage modulus of
6.0.times.10.sup.5 dyn/cm.sup.2 or more. That is, the
pressure-sensitive adhesive layer 400 is formed by curing a
pressure-sensitive adhesive composition, and has a storage modulus
measured at room temperature after curing of 6.0.times.10.sup.5
dyn/cm.sup.2 or more. In the present application, the room
temperature storage modulus is measured by a conventional method,
and may be a value measured using, for example, a dynamic
viscoelasticity measuring device. The term "room temperature" used
herein is a natural temperature that is neither increased nor
decreased, and may differ according to a season, but may be, for
example, approximately -10 to 50.degree. C., 5 to 40.degree. C., 10
to 30.degree. C., or 15 to 25.degree. C.
[0176] When the pressure-sensitive adhesive layer 400 has a room
temperature storage modulus of 6.0.times.10.sup.5 dyn/cm.sup.2 or
more, the pressure-sensitive adhesive layer 400 may have resistance
to external force. That is, a separation phenomenon between the
first region 310 and the pressure-sensitive adhesive layer 400 may
be prevented by absorbing stress caused by contraction or expansion
under a high temperature and/or high humidity. In addition,
cohesive strength corresponding to the shearing stress is also
ensured, and the pressure-sensitive adhesive layer 400 matches the
first region 310. Here, when the pressure-sensitive adhesive layer
400 has a room temperature storage modulus of less than
6.0.times.10.sup.5 dyn/cm.sup.2, the pressure-sensitive adhesive
layer 400 becomes soft, and thus can absorb stress caused by
contraction or expansion of the second region 320, but cohesive
strength capable of corresponding to shearing strength caused by
loads of the display panel 100 and the backward diode 200 may be
reduced.
[0177] Since a higher room temperature storage modulus is, the
better, the upper limit is not particularly limited, but if the
room temperature storage modulus is high, an absorbance to the
stress becomes lower and the separation may occur. Accordingly, the
room temperature storage modulus may be, for example,
1.0.times.10.sup.8 dyn/cm.sup.2 or less.
[0178] In addition, in one example, the pressure-sensitive adhesive
layer 400 may include a pressure-sensitive adhesive resin having a
weight average molecular weight (Mw) of 1,000,000 or more. When the
pressure-sensitive adhesive layer 400 includes a high molecular
weight pressure-sensitive adhesive resin having a weight average
molecular weight (Mw) of 1,000,000 or more, it is advantageous to
improving cohesive strength. To improve the cohesive strength, that
is, enhance the cohesive strength corresponding to shearing stress,
a method of increasing a degree of crosslinking of a
pressure-sensitive adhesive resin using a curing agent may be
considered. However, when the degree of crosslinking of the
pressure-sensitive adhesive resin is increased too much using a
large amount of curing agents, although the cohesive strength is
enhanced, the separation may occur due to a low absorbance to the
stress caused by the contraction or expansion of the second region
320.
[0179] Accordingly, when a high molecular weight resin having a
weight average molecular weight (Mw) of 1,000,000 or more is used
as the pressure-sensitive adhesive resin, the cohesive strength of
the pressure-sensitive adhesive layer 400 may be improved at a low
degree of crosslinking using a small amount of a crosslinking
agent. Since the pressure-sensitive adhesive resin has a higher
weight average molecular weight (Mw), the upper limit is not
particularly limited, but the weight average molecular weight (Mw)
of the pressure-sensitive adhesive resin may be, for example,
5,000,000 or less. A kind of such a pressure-sensitive adhesive
rein is as described above, and may be selected from, for example,
acrylic polymers as exemplified above.
[0180] In addition, when a curing agent is used, that is, a
pressure-sensitive adhesive resin is included as the
pressure-sensitive adhesive composition of the pressure-sensitive
adhesive layer 400 in addition to the curing agent, a content of
the curing agent may be 0.001 to 10 parts by weight with respect to
100 parts by weight of the pressure-sensitive adhesive resin. In
addition, the pressure-sensitive adhesive resin may have a degree
of crosslinking by the curing agent of 80% or less, preferably, for
example, 2 to 80%. Here, when the content of the curing agent and
the degree of crosslinking are higher than the above ranges, the
absorbance to the stress is decreased, and thus the separation may
occur. In consideration of this, the pressure-sensitive adhesive
layer 400 includes the pressure-sensitive adhesive resin and the
curing agent, and the content of the curing agent may be 0.002 to 5
parts by weight, or 0.01 to 0.5 parts by weight with respect to 100
parts by weight of the pressure-sensitive adhesive resin. In
addition, the pressure-sensitive adhesive resin may have a degree
of crosslinking by the curing agent of, for example, 5% to 70%, 10%
to 65%, or 20% to 60%.
[0181] According to the first Example, the pressure-sensitive
adhesive layer 400 satisfies the room temperature storage modulus,
the weight average molecular weight (Mw) and/or the degree of
crosslinking as described above, and may have sufficient cohesive
strength that a dislocated distance is 1 mm or less when a vertical
load of 1 kgf is applied for 4 hours to an area adhered to the
packaging film 300 of 25 mm.times.25 mm (width.times.length) at
room temperature or 80.degree. C. The dislocated distance is
preferably, for example, 0.001 to 1 mm.
(2) Second Example of Pressure-Sensitive Adhesive Layer
[0182] According to the second example, the pressure-sensitive
adhesive layer 400 may have a peeling strength (adhesive strength)
of 0.8 kgf/cm to the packaging film 300 when peeled at a peeling
rate of 30 mm/min at room temperature.
[0183] When the pressure-sensitive adhesive layer 400 has the
above-described peeling strength (adhesive strength), it is
strongly adhered to a contact surface to the packaging film 300,
and the separation due to waves caused by the contraction or
expansion of the second region 320 may be prevented. In addition,
the pressure-sensitive adhesive layer 400 and the packaging film
300 resist the shearing stress caused by loads of the display panel
100 and the backward diode 200, and thus are dislocated.
[0184] In the present application, the peeling strength (adhesive
strength) is measured by a conventional method of measuring peeling
strength used in the field of pressure-sensitive adhesives, and may
be a value measured at a peeling strength of, for example, 180
degrees. The upper limit of the peeling strength (adhesive
strength) is not particularly limited, and may be, for example,
less than or equal to 5.0 kgf/cm. Meanwhile, the pressure-sensitive
adhesive layer 400 may have a room temperature storage modulus of
6.0.times.10.sup.5 dyn/cm.sup.2 or less with the peeling strength
as described above.
[0185] In addition, in one example, the pressure-sensitive adhesive
layer 400 includes an acrylic copolymer as a pressure-sensitive
adhesive resin, and may have a weight average molecular weight (Mw)
of 1,000,000 or more for the above-described reason. Here, the
acrylic copolymer may contain a crosslinked monomer at 0.1 to 10
parts by weight with respect to 90 to 99.9 parts by weight of a
(meth)acrylic acid ester-based monomer having an alkyl group.
[0186] A particular kind of the (meth)acrylic acid ester-based
monomer contained in the acrylic copolymer is not specifically
limited. Here, when the alkyl group contained herein becomes too
long, there is concern of it is apprehended that the cohesive
strength decreasing. Thus, it is preferable that a monomer having
an alkyl group having 1 to 12 carbon atoms be used to maintain
cohesive strength under a high temperature and/or high humidity.
Such a monomer may be at least one selected from the group
consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl
(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,
t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl
(meth)acrylate, 2-ethylbutyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate and
isononyl (meth)acrylate.
[0187] In addition, the (meth)acrylic acid ester-based monomer is
included at 90 to 99.9 parts by weight with respect to the acrylic
copolymer. Here, when the content of the (meth)acrylic acid
ester-based monomer is less than 90 parts by weight, initial
adhesive strength of the pressure-sensitive adhesive may be
degraded, and when the content of the (meth)acrylic acid
ester-based monomer is more than 99.9 parts by weight, cohesive
strength may be decreased.
[0188] In addition, the crosslinked monomer contained in the
acrylic copolymer is not particularly limited as long as it
contains a crosslinkable functional group, and may be at least one
selected from the group consisting of a hydroxyl group-containing
monomer, a carboxyl group-containing monomer and a
nitrogen-containing monomer. Such a crosslinked monomer is reacted
with a crosslinking agent to form a crosslinked structure, and thus
cohesive strength and adhesive strength may be provided to prevent
breakage of the cohesive strength of the pressure-sensitive
adhesive under a high temperature and/or high humidity.
[0189] As the crosslinked monomer, the hydroxyl group-containing
monomer may be at least one selected from 2-hydroxyethyl
(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl
(meth)acrylate, 6-hydroxyhexyl (meth)acrylate,
2-hydroxyethyleneglycol (meth)acrylate and 2-hydroxypropyleneglycol
(meth)acrylate, the carboxyl group-containing monomer may be at
least one selected from (meth)acrylic acid, an acrylic acid dimer,
itaconic acid, maleic acid, maleic acid anhydride and fumaric acid,
or the nitrogen-containing monomer may be at least one selected
from acryl amide, N-vinylpyrrolidone and N-vinyl caprolactone.
[0190] The crosslinked monomer may be included at 0.1 to 10 parts
by weight in the acrylic copolymer. Here, when the content of the
crosslinked monomer is less than 0.1 parts by weight, breakage of
cohesion may occur under a high temperature and/or a high
temperature and humidity, and when the content is more than 10
parts by weight, a surface transfer phenomenon may occur due to a
decrease in compatibility, a flowing characteristic may be
decreased and/or stress relaxation may be degraded due to an
increase in cohesive strength.
[0191] In addition, the acrylic copolymer may further contain a
copolymerizable monomer. The copolymerizable monomer may be added
to control a glass transition temperature and provide other
functionalities. Such a copolymerizable monomer may be, but is not
limited to, at least one selected from acrylonitrile, a
nitrogen-containing monomer such as (meth)acrylamide, N-methyl
(meth)acrylamide and/or N-butoxy methyl (meth)acrylamide; a
styrene-based monomer such as styrene and/or methyl styrene;
glycidyl (meth)acrylate; and vinyl acetate.
[0192] Here, the copolymerizable monomer may be contained at 40
parts by weight with respect to 90 to 99.9 parts by weight of the
(meth)acrylic acid ester-based monomer. When the content of the
copolymerizable monomer is more than 40 parts by weight,
flexibility and/or peeling strength of the pressure-sensitive
adhesive composition may be degraded.
[0193] According to a more particular exemplary embodiment, the
pressure-sensitive adhesive layer 400 includes an acrylic copolymer
as a pressure-sensitive adhesive resin. The acrylic copolymer may
contain 5 to 40 parts by weight of methyl (meth)acrylate, 5 to 40
parts by weight of a copolymerizable monomer, and 0.1 to 1.0 parts
by weight of a crosslinked monomer with respect to 50 to 99 parts
by weight of a (meth)acrylic monomer having an alkyl group having 4
to 12 carbon atoms. Kinds of the components constituting such an
acrylic copolymer are described above. When the acrylic copolymer
composed as described above is included, it is preferable to
improving physical properties such as peeling strength (adhesive
strength) and/or a room temperature storage modulus.
[0194] In addition, the pressure-sensitive adhesive composition for
the pressure-sensitive adhesive layer 400 may further include 0.01
to 10 parts by weight of a crosslinking agent with respect to 100
parts by weight of the acrylic copolymer, in addition to the
acrylic copolymer as described above. The crosslinking agent is
reacted with a crosslinked monomer included in the acrylic
copolymer to serve to control a pressure-sensitive adhesive
characteristic of the pressure-sensitive adhesive composition and
enhance cohesive strength. A particular kind of the crosslinking
agent is not specifically limited, and may be an isocyanate-based
compound, an epoxy-based compound, an aziridine-based compound
and/or a metal chelate-based compound as described above.
[0195] Here, the isocyanate-based compound may be at least one
selected from the group consisting of tolylene diisocyanate, xylene
diisocyanate, diphenylmethane diisocyanate, hexamethylene
diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate
or naphthalene diisocyanate, and in some cases, a reaction product
of at least one of the isocyanate compounds described above and a
polyol (e.g., trimethylol propane) may be used. In addition, the
epoxy-based compound may be at least one selected from the group
consisting of ethyleneglycol diglycidylether, triglycidylether,
trimethylolpropane triglycidylether, N,N,N',N'-tetraglycidyl
ethylenediamine and glycerine diglycidylether, the aziridine-based
compound may be at least one selected from the group consisting of
N,N'-toluene-2,4-bis(1-aziridinecarboxide),
N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxide), triethylene
melamine, bisisoprotaloyl-1-(2-methylaziridine) and
tri-1-aziridinylphosphineoxide, and the metal chelate-based
compound may be a compound in which a polyvalent metal such as
aluminum, iron, zinc, tin, titanium, antimony, magnesium and/or
vanadium is coordinated with acetyl acetone or ethyl acetoacetate,
but the present application is not limited thereto.
[0196] Moreover, the pressure-sensitive adhesive composition for
the pressure-sensitive adhesive layer 400 may further include a
pressure-sensitive adhesion-providing resin at 1 to 100 parts by
weight with respect to 100 parts by weight of the acrylic copolymer
to control pressure-sensitive adhesive performance. A kind of such
a pressure-sensitive-adhesion-providing resin is not specifically
limited, and may be, for example, at least one selected from a
(hydrogenated) hydrocarbon-based resin, a (hydrogenated) rosin
resin, a (hydrogenated) rosin ester resin, a (hydrogenated) terpene
resin, a (hydrogenated) terpene phenol resin, a polymerized rosin
resin, and a polymerized rosin ester resin. Here, when the content
of the pressure-sensitive adhesion-providing resin is less than 1
part by weight, an addition effect may be insignificant, and when
the content is more than 100 parts by weight, compatibility and/or
cohesive strength-enhancing effects are probably degraded.
[0197] In addition, the pressure-sensitive adhesive composition for
the pressure-sensitive adhesive layer 400 may further include a
silane coupling agent at 0.005 to 5 parts by weight with respect to
100 parts by weight of the acrylic copolymer. The silane coupling
agent may serve to improve thermal resistance and moisture
resistance by increasing adhesive stability, and enhance adhesive
reliability when maintained for a long time under a high
temperature and/or high humidity. A kind of the silane coupling
agent is not specifically limited, and may be, for example, at
least one selected from .gamma.-glycidoxypropyltrimethoxy silane,
.gamma.-glycidoxypropylmethyldiethoxy silane,
.gamma.-glycidoxypropyltriethoxy silane, 3-mercaptopropyltrimethoxy
silane, vinyltrimethoxy silane, vinyltriethoxy silane,
.gamma.-methacryloxypropyltrimethoxy silane,
.gamma.-methacryloxypropyltrimethoxy silane,
.gamma.-methacryloxypropyltriethoxy silane,
.gamma.-aminopropyltrimethoxy silane, .gamma.-aminopropyltriethoxy
silane, 3-isocyanatopropyltriethoxy silane, and
.gamma.-acetoacetatepropyltrimethoxy silane. Here, when a content
of the silane coupling agent is less than 0.005 parts by weight,
the addition effect may be insignificant, and when a content of the
silane coupling agent is more than 5 parts by weight, durability
and reliability may be degraded due to a bubbling or peeling
phenomenon.
[0198] In addition, the pressure-sensitive adhesive composition for
the pressure-sensitive adhesive layer 400 may further include a
curing agent. Here, when a pressure-sensitive adhesive resin (e.g.,
an acrylic copolymer) and a curing agent are included as the
pressure-sensitive adhesive composition for the pressure-sensitive
adhesive layer 400, a content of the curing agent may be 0.001 to
10 parts by weight with respect to 100 parts by weight of the
pressure-sensitive adhesive resin. When the content of the curing
agent is less than 0.001 parts by weight, a
cohesive-strength-improving effect of the pressure-sensitive
adhesive layer 400 according to the addition of the curing agent
may be insignificant, and when the content of the curing agent is
more than 10 parts by weight, separation may occur due to low
absorbance to a stress. In consideration of this, the
pressure-sensitive adhesive layer 400 includes a pressure-sensitive
adhesive resin and a curing agent, and a content of the curing
agent may be 0.002 to 5 parts by weight or 0.01 to 0.5 parts by
weight with respect to 100 parts by weight of the
pressure-sensitive adhesive resin.
[0199] According to the second example, the pressure-sensitive
adhesive layer 400 satisfies the peeling strength (adhesive
strength), the room temperature storage modulus, the weight average
molecular weight (Mw) and/or the degree of crosslinking as
described above, and may have sufficient cohesive strength that a
dislocated distance is 0.5 mm or less when a vertical load of 1 kgf
is applied for 4 hours to an adhesive area to the packaging film
300 of 25 mm.times.25 mm at room temperature or 80.degree. C.
Preferably, the dislocated distance is, for example, 0.001 to 0.5
mm.
(3) Third Example of Pressure-Sensitive Adhesive Layer
[0200] According to the third example, the pressure-sensitive
adhesive layer 400 includes a photocurable pressure-sensitive
adhesive composition, and preferably has a room temperature storage
modulus after photocuring of 1.0.times.10.sup.6 dyn/cm.sup.2 or
more. That is, the pressure-sensitive adhesive layer 400 is formed
by curing a photocurable pressure-sensitive adhesive composition,
and has a storage modulus measured at room temperature after
photocuring of 1.0.times.10.sup.6 dyn/cm.sup.2 or more.
[0201] When the pressure-sensitive adhesive layer 400 has a room
temperature storage modulus of 1.0.times.10.sup.6 dyn/cm.sup.2 or
more, resistance to external force may be ensured. That is, the
separation phenomenon between the first region 310 and the
pressure-sensitive adhesive layer 400 may be prevented by absorbing
stress caused by contraction or expansion under a high temperature
and/or high humidity. In addition, cohesive strength corresponding
to the shearing stress is ensured, thereby preventing dislocation.
Here, when the pressure-sensitive adhesive layer 400 has a room
temperature storage modulus of less than 1.0.times.10.sup.6
dyn/cm.sup.2, the pressure-sensitive adhesive layer 400 becomes
soft, and may absorb stress caused by the contraction or expansion
of the second region 320, but cohesive strength corresponding to
shearing stress caused by the loads of the display panel 100 and
the backward diode 200 may be reduced.
[0202] Since a higher room temperature storage modulus is better,
the upper limit is not specifically limited, but when the room
temperature storage modulus is too high, in some cases, the
absorbance to stress is decreased, and thus the separation may
occur. Accordingly, the room temperature storage modulus may be,
for example, 1.0.times.10.sup.8 dyn/cm.sup.2 or less.
[0203] In addition, in one example, the pressure-sensitive adhesive
layer 400 may include a pressure-sensitive adhesive resin having a
weight average molecular weight (Mw) of 1,000,000 or more for the
above-described reason. A kind of the pressure-sensitive adhesive
resin is as described above, and may be selected from, for example,
the photocurable acrylic copolymers as described above.
[0204] According to exemplary examples, the pressure-sensitive
adhesive layer 400 may be formed of a photocurable
pressure-sensitive adhesive composition including an acryl
copolymer, a photocurable multifunctional acrylate, and a curing
agent. In addition, as needed, the pressure-sensitive adhesive
layer 400 may further include a photoinitiator. Kinds of components
constituting such a photocurable pressure-sensitive adhesive
composition are described above. When the display panel 100 is
adhered to the backward diode 200 using such a photocurable
pressure-sensitive adhesive composition, and UV radiation is
performed thereon, a multifunctional acrylate is cured, and thus a
strong adhesive characteristic may be ensured.
[0205] According to a more particular example, the
pressure-sensitive adhesive layer 400 may include 2 to 30 parts by
weight of a photocurable multifunctional acrylate and 0.001 to 10
parts by weight of a curing agent with respect to 100 parts by
weight of an acryl copolymer. In addition, as needed, the
pressure-sensitive adhesive layer 400 may further include 0.001 to
10 parts by weight of a photoinitiator with respect to 100 parts by
weight of the acrylic copolymer.
[0206] According to the third example, the pressure-sensitive
adhesive layer 400 satisfies the room temperature storage modulus,
the weight average molecular weight (Mw) and/or the degree of
crosslinking as described above, and may have sufficient cohesive
strength that a dislocated distance is 0.2 mm or less when a
vertical load of 1 kgf is applied for 4 hours to an area adhered to
the packaging film 300 of 25 mm.times.25 mm (width.times.length) at
room temperature or 80.degree. C.
[0207] In addition, referring to FIGS. 2 to 4, according to the
thirteenth embodiment of the present application, a barrier layer
500 may be formed on a side surface of the display panel 100.
[0208] The barrier layer 500 may prevent penetration of at least
external moisture into the display panel 100. To this end, the
barrier layer 500 may have at least moisture impermeability
(moisture blockage). In addition, the barrier layer 500 may prevent
the penetration of a gas such as external air, in addition to,
moisture, and to this end, the barrier layer 500 may have
impermeability to a gas such as air, in addition to the moisture
blockage.
[0209] In the present application, the barrier layer 500 is not
specifically limited as long as it has at least moisture blockage.
The barrier layer 500 may include at least one selected from, for
example, a moisture-blocking resin layer, a metal thin film and a
deposition layer.
[0210] The moisture-blocking resin layer may be a film layer formed
by adhering a moisture-blocking resin film to the display panel
100, or a resin coating layer formed by coating a moisture-blocking
resin composition to a side surface of the display panel 100. The
resin composition constituting such a moisture-blocking resin layer
is not limited, and includes heat-curable and photocurable
compositions. In addition, the moisture-blocking resin layer may
have, for example, a structure of one or at least two layer.
[0211] The moisture-blocking resin layer may include, for example,
a styrene-based resin, a polyolefin-based resin, a thermoplastic
elastomer, a polyoxyalkylene-based resin, a polyester-based resin,
a polyvinyl chloride-based resin, a PC-based resin, a
polyphenylenesulfide-based resin, a mixture of hydrocarbons, a
polyamide-based resin, an acrylate-based resin, an epoxy-based
resin, a silicon-based resin, a fluorine-based resin and/or a
mixture thereof.
[0212] The styrene-based resin may be, for example, a
styrene-ethylene-butadiene-styrene (SEBS) block copolymer, a
styrene-isoprene-styrene (SIS) block copolymer, an
acrylonitrile-butadiene-styrene (ABS) block copolymer, an
acrylonitrile-styrene-acrylate (ASA) block copolymer, a
styrene-butadiene-styrene (SBS) block copolymer, a styrene-based
homopolymer, and/or a mixture thereof. The olefin-based resin may
be, for example, a high-density PE-based resin, a low-density
PE-based resin, a PP-based resin and/or a mixture thereof. The
thermoplastic elastomer may include, for example, an ester-based
thermoplastic elastomer, an olefin-based thermoplastic elastomer
and/or a mixture thereof. Among these, as the olefin-based
thermoplastic elastomer, a polybutadiene resin and/or a
polyisobutene resin may be used. The polyoxyalkylene-based resin
may be, for example, a polyoxymethylene-based resin, a
polyoxyethylene-based resin and/or a mixture thereof. The
polyester-based resin may be, for example, a polyethylene
terephthalate-based resin, a polybutylene terephthalate-based resin
and/or a mixture thereof. The polyvinylchloride-based resin may be,
for example, polyvinylidene chloride. The mixture of the
hydrocarbon may be, for example, hexatriacontane and/or paraffin.
The polyamide-based resin may be, for example, nylon. The
acrylate-based resin may be, for example, polybutyl(meth)acrylate.
The epoxy-based resin may be, for example, a bisphenol type such as
a bisphenol A-, bisphenol F-, or bisphenol S-type epoxy-based resin
or a hydrogenated product thereof; a novolac type such as a
phenolnovolac- or cresolnovolac-type epoxy-based resin; a
nitrogen-containing cyclic type such as a cyclic
triglycidylisocyanurate- or hydantoin-type epoxy-based resin; an
alicyclic type; an aliphatic type; an aromatic type such as a
naphthalene-type epoxy-based resin or a biphenyl-type epoxy-based
resin; a glycidyl type such as a glycidylether-type epoxy-based
resin, a glycidylamine-type epoxy-based resin, or a
glycidylester-type epoxy-based resin; a dicyclo type such as a
dicyclopentadiene-type epoxy-based resin; an ester type; an
etherester type; or a mixture thereof. The silicon-based resin may
be, for example, a polydimethylsiloxane. In addition, the
fluorine-based resin may be a polytrifluoroethylene resin, a
polytetrafluoroethylene resin, a polychlorotrifluoroethylene resin,
a polyhexafluoropropylene resin, a polyvinylidene fluoride, a
polyvinyl fluoride, a polyethylene propylene fluoride and/or a
mixture thereof.
[0213] The resin listed as a component of the moisture-blocking
resin layer may be grafted with maleic acid anhydride,
copolymerized with another resin listed above or a monomer for
preparing a resin, or modified by another compound, which may be a
carboxyl-terminated butadiene-acrylonitrile copolymer.
[0214] In addition, the resin listed as the moisture-blocking resin
layer may include at least one heat-curable functional group or
site such as a glycidyl, isocyanate, hydroxyl, carboxyl, or amide
group, or at least one active energy ray-curable functional group
or site such as an epoxide, cyclic ether, sulfide, acetal or
lactone group to exhibit an adhesive property after curing.
[0215] In one example, the moisture-blocking resin layer may
include a polyisobutene resin. The polyisobutene resin may exhibit
a low water vapor transmission rate (WVTR) and surface energy due
to hydrophobicity. Particularly, the polyisobutene resin may be,
for example, a homopolymer of an isobutylene monomer; and/or a
copolymer prepared by copolymerizing another monomer which can be
polymerized with an isobutylene monomer. Here, the monomer which
can be polymerized with an isobutylene monomer may be, for example,
1-butene, 2-butene, isoprene or butadiene.
[0216] In addition, as a component of the moisture-blocking resin
layer, a base resin having a weight average molecular weight (Mw)
at which it can be molded in a film type may be used. According to
an exemplary embodiment, the range of the weight average molecular
weight (Mw) at which the base resin can be molded in a film type
may be approximately 100,000 to 2,000,000, 100,000 to 1,500,000 or
100,000 to 1,000,000.
[0217] According to another exemplary embodiment, the
moisture-blocking resin layer may further include a moisture
remover, in addition to the above-described resin component.
Accordingly, the moisture blockage of the moisture-blocking resin
layer may be further enhanced. For example, the moisture remover
may be uniformly dispersed in the resin layer. Here, the uniformly
dispersed state may be a state in which a moisture remover is
present at the same or substantially the same density in all parts
of the moisture-blocking resin layer.
[0218] The moisture remover may be, for example, a metal oxide, a
sulfate or an organic metal oxide. Here, although not specifically
limited, the metal oxide may be magnesium oxide, calcium oxide,
strontium oxide, barium oxide or aluminum oxide, the sulfate may be
magnesium sulfoxide, sodium sulfoxide or nickel sulfoxide, and the
organic metal oxide may be aluminum oxide octylate.
[0219] The moisture remover may use one of the above-described
components, or at least two thereof. In addition, when at least two
components are used as the moisture remover, for example, calcined
dolomite may be used.
[0220] Such a moisture remover may have a suitable size. In one
example, an average particle diameter of the moisture remover may
be controlled to approximately 10 to 15,000 nm. The moisture
remover having the above range of size may effectively block
moisture. A content of the moisture remover may be, for example, 5
to 250 parts by weight with respect to 100 parts by weight of the
resin capable of being used as moisture-blocking resin layer
described above.
[0221] In addition, the moisture-blocking resin layer may further
include a dispersing agent such that the moisture remover is
uniformly dispersed in the resin layer. As the dispersing agent
capable of being used herein, for example, a non-ionic surfactant
having an affinity to a hydrophilic surface of the moisture remover
and a compatibility with the resin may be used. According to
another exemplary embodiment, when the moisture-blocking resin
layer has moisture preventability, heat-curable and photocurable
pressure-sensitive adhesive composition as described with regard to
the pressure-sensitive adhesive layer 400 may be included.
[0222] Metal foil having a thickness of 1 to 300 .mu.m may be used
as the metal thin film, and for example, a barrier layer 500 may be
formed by adhering the metal thin film to the display panel 100
using an adhesive.
[0223] In addition, the deposition layer is formed by depositing at
least one selected from metals and metal oxides, and may be
deposited on a base film, for example, PET, PE or PP, and adhered
to the display panel 100 with the base film, thereby forming a
barrier layer 500.
[0224] In the present application, a metal applied as the barrier
layer 500, particularly, a metal constituting the metal thin film
or deposition layer may be, but is not limited to, at least one
selected from the group consisting of aluminum (Al), copper (Cu),
nickel (Ni), tin (Sn), zinc (Zn), indium (In), silver (Ag),
tungsten (W) and iron (Fe), or an alloy of at least two thereof. In
addition, the metal oxide capable of being used as the deposition
layer may be selected from, for example, aluminum oxide
(Al.sub.2O.sub.3), silicon oxide (SiO.sub.2), tin oxide
(SnO.sub.2), indium oxide (In.sub.2O.sub.3) and zinc oxide
(ZnO).
[0225] In addition, the barrier layer 500 includes the
above-described moisture-blocking resin layer, which may be formed
by coating a heat-curable and photocurable resin composition
(pressure-sensitive adhesive composition), and have a peeling
strength (pressure-sensitive adhesive strength) of 2.5 kgf/inch or
more. The upper limit of the peeling strength is not limited. When
the composition has such peeling strength, for example, binding
strength to the multi-layer structure display panel 100 may be
reinforced. Particularly, as the moisture-blocking resin layer is
also pressure-sensitivly adhered and fixed to side surfaces of a
liquid crystal cell layer 120, an upper polarizing plate 140 and a
lower polarizing plate 160, the binding strength between the layers
of the display panel 100 may be reinforced. Particularly, a peeling
strength of the moisture-blocking resin layer may be 2.5 or 20.0
kgf/inch.
[0226] According to the thirteenth embodiment of the present
application, the packaging film 300 according to the present
application may further include the pressure-sensitive adhesive
layer as described above as a part of the components. According to
an example, the packaging film 300 of the present application may
have a structure in which the pressure-sensitive adhesive layer 400
as described above may be further formed in at least a first region
310. In addition, a releasing paper may be stacked on the
pressure-sensitive adhesive layer 400. According to another
example, the packaging film 300 of the present application may have
a structure in which a pressure-sensitive adhesive layer that
provides an adhesive strength to the backward diode 200, that is,
the second pressure-sensitive adhesive layer as described above, is
further formed on at least one selected from the second region 320
and the third region 330. Moreover, the releasing paper may be
stacked on the second pressure-sensitive adhesive layer.
[0227] In addition, according to another embodiment of the present
application, the packaging film 300 of the present application may
have a structure in which a protective film is formed on the first
region 310, and the pressure-sensitive adhesive layer 400 is formed
on the protective film. In addition, a releasing paper may be
adhered to the pressure-sensitive adhesive layer 400. Here, the
protective film may be selected from resin films, for example,
films including TAC and/or an acrylic resin. Such a protective film
may have adhesive strength to the first region 310 through a
pressure-sensitive adhesive. The releasing paper is not
specifically limited, as long as it can protect the
pressure-sensitive adhesive layer 400, and thus, for example, a
resin film or paper having releasability may be used.
[0228] According to the first example of the present application
described above, an improved display device is embodied. For
example, when the backward diode 200 of the optical diode 200A is
packaged by the packaging film 300, and adhered to a bottom surface
of the display panel 100 through the pressure-sensitive adhesive
layer 400, a bezel region becomes minimized. That is, as the use of
a molding frame to fix the display panel 100 with the backward
diode 200 is excluded, a bezel-free display device in which almost
no bezel is included may be embodied.
[0229] In addition, the backward diode 200, for example, does not
consume too much time or cause damage to the optical diode 200A,
which can occur in handling and assembly of the optical diode 200A
on a film (or sheet). In addition, the optical diode 200A is
packaged by the packaging film 300 to have sealability, and thus a
light leakage phenomenon is prevented.
Second Embodiment
[0230] Hereinafter, a packaging film 300' according to a second
embodiment of the present application will be explained.
[0231] In FIGS. 10 to 17, examples of the packaging film 300'
according to the second embodiment of the present application are
shown. To explain the second embodiment of the present application,
the same terms and reference marks as in the first embodiment
exhibit the same functions, and thus detailed description thereof
will be omitted. Hereinafter, any part that is not specifically
explained is the same as in the first embodiment. For example, this
applies to materials and physical properties of the packaging film
300'. In addition, in some cases, the first embodiment may include
a configuration of the second embodiment which will be explained
below.
[0232] The packaging film 300' surrounds and packages a top surface
101 and a side surface 102 of a display panel 100. In addition, the
packaging film 300' surrounds and packages at least a side surface
202 of a backward diode 200. To this end, the packaging film 300'
includes a first region 310 corresponding to the top surface 101 of
the display panel 100 and a second region 320 corresponding to the
side surface 102 of the display panel 100 and a side surface 202 of
the backward diode 200. The second region 320 extends from the
first region 310.
[0233] The display device includes the packaging film 300' of the
present application as described above. The display device includes
the display panel 100 according to an exemplary example, the
backward diode 200 equipped on a bottom surface of the display
panel 100, and the packaging film 300' packaging the display panel
100 and the backward diode 200.
[0234] Hereinafter, in the description of the exemplary embodiment
of the second embodiment, the packaging film 300' of the present
application is also described by describing the display device.
[0235] The display panel 100 and the backward diode 200 are the
same as described in the first embodiment. The display panel 100
may be any one capable of displaying an image as described in the
first embodiment.
[0236] FIGS. 10 to 12 are exemplary examples of the display panel
100. FIGS. 10 to 12 particularly show a liquid crystal display
(LCD) panel.
[0237] Referring to FIGS. 10 to 12, the display panel 100 may
include, for example, at least one liquid crystal cell layer 120,
and a top surface polarizing plate 140 formed on the liquid crystal
cell layer 120 and a bottom surface polarizing plate 160 formed
under the liquid crystal cell layer 120 as polarizing plates formed
on both surfaces of the liquid crystal cell layer 120.
[0238] The backward diode 200 is not particularly limited, as long
as it is equipped on the bottom surface of the display panel 100 as
described in the first embodiment. The backward diode 200 may be
composed of one member, or a multi-layer structure including at
least two members. The backward diode 200 may have, for example, a
film, sheet, plane, and/or three-dimensional shape. Particularly,
the backward diode 200 may include at least one selected from an
electric/electronic diode having an electric/electronic function,
an optical diode having an optical function, and/or a heat
dissipation diode having a heat dissipating function.
[0239] FIG. 10 shows a backward diode 200 composed of one member.
Here, the backward diode 200 shown in FIG. 10 may be selected from,
for example, an optical diode 200A, an electronic circuit board,
and a heat dissipation plate. Particularly, for example, the
backward diode 200 may be selected from the optical diode 200A.
[0240] The optical diode 200A may be a diode having, for example,
light diffusing, concentrating, polarizing and/or reflecting
function(s), but the present application is not limited thereto. In
addition, the optical diode 200A may include a light source
generating light. In the present application, the optical diode
200A includes a light source generating light, and all kinds of
devices, films and/or sheets used to treat light. The optical diode
200A may include at least one optical member 200a selected from,
for example, a light guide plate, a diffuser sheet, a brightness
enhancement film, a prism film, a lens film, a polarizing film, a
reflective film, a viewing angle compensation film, a retardation
film and a protective film for protecting it.
[0241] In addition, the optical diode 200A may be selected from a
light source assembly further including a light source 240 in the
optical member 200a as described above. In the present application,
a particular embodiment of the light source assembly is not
specifically limited, and may be selected from, for example,
conventional direct-type and edge-type light source assemblies.
Particularly, the light source assembly serving as the optical
diode 200A may be selected from a BLU conventionally used in an LCD
device.
[0242] FIGS. 11 and 12 show backward diodes 200, which are
multi-layer optical diodes 200A. Particularly, as the backward
diode 200, FIG. 11 is an optical diode 200A including a plurality
of optical members 200a, and FIG. 12 is an optical diode 200A
including a plurality of optical members 200a and a light source
240.
[0243] Referring to FIG. 11, the optical diode 200A may include a
light guide plate 210 converting a point light source emitted from
a light source into a surface light source, and a diffuser sheet
220 formed on the light guide plate 210 and diffusing light
generated from the light guide plate 210 optical members 200a. In
addition, the optical diode 200A may further include a brightness
enhancement film 230 formed on the diffuser sheet 220. Furthermore,
such optical members 200a may be formed in one or at least two
layers. In FIG. 11, a brightness enhancement film 230 having a
bilayer structure is shown. Such an optical diode 200A is, as shown
in FIG. 11, packaged by the packaging film 300' and equipped on a
bottom surface of the display panel 100. Here, in FIG. 11, a light
source providing light to the light guide plate 210 is not shown,
but the light source may be separately equipped outside to provide
light to the light guide plate 210.
[0244] In addition, referring to FIG. 12, the optical diode 200A
may be packaged by a packaging film 300' with the display panel
100, after a plurality of optical members 200a and a light source
240 are formed in an assembly. Particularly, the optical diode 200A
is a light source assembly including the light source 240, which
may include at least one light source 240, a light guide plate 210
formed on the light source 240 and converting a point light source
emitted from the light source 240 into a surface light source, and
a diffuser sheet 220 formed on the light guide plate 210 and
diffusing light emitted from the light guide plate 210. In
addition, as shown in FIG. 12, the optical diode 200A may further
include a brightness enhancement film 230 formed on the diffuser
sheet 220.
[0245] The packaging film 300' packages the display panel 100 and
the backward diode 200 described above. Here, as the backward diode
200, when the optical diode 200A is packaged, the light source 240
may not be packaged by the packaging film 300' as shown in FIG. 11,
or may be packaged along with the optical member 200a as shown in
FIG. 12.
[0246] The packaging film 300' includes a first region 310, and a
second region 320 extending from the first region 310. The first
region 310 corresponds to a top surface 101 of the display panel
100. In addition, the second region 320 corresponds to a side
surface 102 of the display panel 100 and a side surface 202 of the
backward diode 200. Referring to FIG. 12, the second region 320
includes a first flap 321 extending from the first region 310 and a
second flap 322 extending from the first flap 321. In addition, the
first flap 321 corresponds to the side surface 102 of the display
panel 100, and the second flap 322 corresponds to the side surface
202 of the backward diode 200.
[0247] The packaging film 300' further includes, preferably, a
third region 330 providing strong fixing strength between the
display panel 100 and the backward diode 200. The third region 330
extends from the second region 320, and corresponds to a bottom
surface 203 of the backward diode 200.
[0248] In FIGS. 13 to 17, exemplary examples of the packaging film
300' are shown.
[0249] At least the first region 310 and the second region 320 of
the regions 310, 320 and 330 of the packaging film 300' may have
areas equal or similar to the parts corresponding thereto. For
example, the area of the first region 310 may be equal or similar
to that of the top surface 101 of the display panel 100. In
addition, the area of the second region 220 may be equal or similar
to the sum of the area of the side surface 102 of the display panel
100 and the area of the side surface 202 of the backward diode 200.
More particularly, an area of the first flap 321 may be equal or
similar to the area of the side surface 102 of the display panel
100, and an area of the second flap 322 may be equal or similar to
the area of the side surface 202 of the backward diode 200.
[0250] In addition, at least two of the second regions 320 may be
included. For example, two to four second regions 320 may be
included. That is, the second region 320 extends from the first
region 310, and may be at least two of the four surfaces of the
first region 310. In addition, for example, there may be two to
four third regions 330, which may be the same as the number of the
second regions 320. For example, in FIG. 13, there are three second
regions 320, and there are also three third regions 330.
[0251] The packaging film 300' is not limited as long as it
includes the first region 310 and the second region 320 as shown
above, and preferably further includes the third region 330. In
addition, the regions 310, 320 and 330 may be formed in one
process. The packaging film 300' may be formed in one process
without a joint between the regions 310, 320 and 330 by, for
example, cutting one film to have the regions 310, 320 and 330 as
shown above.
[0252] A material of the packaging film 300' is the same as that
used in the packaging film 300 according to the first embodiment.
The packaging film 300' may be selected from transparent films. The
packaging film 300' may have optical properties including
polarization, concentration and/or diffusion of light when needed.
At least the first region 310 may have such optical properties. In
this case, it can be useful to package the optical diode 200A.
[0253] In addition, the packaging film 300' may be selected from
isotropic films. In the present application, the isotropy is such
that the film has little to no retardation, to the extent that no
substantial influence is exerted on a phase of light penetrating
through the film.
[0254] The packaging film 300' may have an in-plane retardation
(R.sub.in) of, for example, 30 nm or less. The packaging film 300'
may have an in-plane retardation (R.sub.in) calculated by Equation
1 of 30 nm or less, 25 nm or less, or 10 nm or less, and
preferably, for example, approximately 0 to 25 nm, 0 to 10 nm, 0.1
to 5 nm, 0.2 to 3 nm, or 0.5 to 2 nm.
[0255] In addition, the packaging film 300' may have a
thickness-direction retardation (R.sub.th) of 35 nm or less. The
packaging film 300' may have a thickness-direction retardation
(R.sub.th) calculated by Equation 2 of, for example, 35 nm or less,
30 nm or less, 20 nm or less, or 10 nm or less, and preferably, for
example, 0 to 30 nm, 0 to 20 nm, 0 to 10 nm, 0.1 to 5 nm, or 0.2 to
3 nm.
[0256] In the packaging of the display panel 100 and the backward
diode 200, the regions 310, 320 and 330 of the packaging film 300'
are bent on boundary lines C1 and C2. In the drawings, the boundary
lines C1 and C2 between the regions 310, 320 and 330 are shown by
dotted lines. Here, the boundary lines C1 and C2 are represented
for convenience of description, and may or may not actually visible
on the packaging film 300'.
[0257] To package the display panel 100 and the backward diode 200
using the packaging film 300', for example, first, the first region
30 is located to correspond to the top surface 101 of the display
panel 100, and on the first boundary line C1, the second region 320
is bent, and then the second region 320 is located to correspond to
the side surface 102 of the display panel 100 and the side surface
202 of the backward diode 200. In addition, when the third region
330 is further included, on the second boundary line (C2), the
third region 330 is bent, and then the third region 330 is located
to correspond to the bottom surface 203 of the backward diode 200
for packaging.
[0258] According to an exemplary embodiment, the packaging film
300' may have adhesive strength between the display panel 100 and
the backward diode 200. The adhesive strength may be generated, for
example, at a contact interface between the display panel 100 and
the backward diode 200. The adhering method may be performed by,
for example, applying thermal and/or photo laminating method(s)
without specific limitation. For example, the display panel 100 and
the backward diode 200 may be adhered by applying heat or radiating
light to the packaging film 300' for fusion. In the adhesion
through such a laminating method, conditions for radiating heat and
light may be suitably selected according to a kind of the packaging
film 300' without specific limitation.
[0259] The packaging film 300' may have adhesive strength by being
fused with the display panel 100 and the backward diode 200, for
example, in at least one selected from the second region 320 and
the third region 330.
[0260] According to another exemplary embodiment, the packaging
film 300' may have adhesive strength to the display panel 100 and
the backward diode 200 by a separate adhesive means. The adhesive
means may be a pressure-sensitive adhesive layer (not shown)
formed, for example, between the packaging film 300' and the
display panel 100, and/or between the packaging film 100 and the
backward diode 200.
[0261] The pressure-sensitive adhesive layer is preferably formed
at a contact interface between the packaging film 300' and the
display panel 100, and/or at a contact interface between the
packaging film 300' and the backward diode 200, thereby providing
binding strength therebetween. Such a pressure-sensitive adhesive
layer may be coated on the packaging film 300', or coated on the
display panel 100 and the backward diode 200.
[0262] For example, the pressure-sensitive adhesive layer may be
formed in at least one selected from the second region 320 and the
third region 330. Particularly, the pressure-sensitive adhesive
layer may be formed on inner surfaces of at least the second region
320 and/or the third region 330 among the regions 310, 320 and 330
of the packaging film 300', that is, on a surface in contact with
the display panel 100 and the backward diode 200.
[0263] The pressure-sensitive adhesive layer is not specifically
limited, as long as it has adhesive strength (pressure-sensitive
adhesive strength), and may be formed by, for example, coating a
pressure-sensitive adhesive composition. The pressure-sensitive
adhesive composition may be selected from, for example,
photocurable and/or heat-curable pressure-sensitive adhesive
composition(s), which is the same as described in the first
embodiment.
[0264] The packaging film 300' may be adhered at least between the
second region 320 and the side surfaces 102 and 202, and/or between
the third region 330 and the bottom surface 203 by fusion through
heat and/or light or adhesion through the pressure-sensitive
adhesive layer as described above.
[0265] In addition, the adhesive means may be, in another example,
a double-sided or single-sided pressure-sensitive adhesive tape.
Here, the double-sided pressure-sensitive adhesive tape may be
interposed between the packaging film 300' and the panel 100/diode
200. Preferably, the double-sided pressure-sensitive adhesive tape
may be interposed between the second region 320 and the side
surfaces 102 and 202, and/or between the third region 330 and the
bottom surface 203. In addition, the single-sided
pressure-sensitive adhesive tape may be taped on an outer surface
of the third region 330 to provide binding strength to the backward
diode 200.
[0266] According to an exemplary embodiment, to provide strong
fixing strength between the display panel 100 and the backward
diode 200, the pressure-sensitive adhesive layer may be formed
therebetween. The pressure-sensitive adhesive layer is the same as
the pressure-sensitive adhesive layer 400 according to the first
embodiment, and thus the description thereof will be omitted.
[0267] Referring to FIGS. 13 and 14, a notch part 350 may be formed
on the boundary line C1 between the first region 310 and the second
region 320. In addition, when the packaging film 300' further
includes the third region 330, the notch part 350 may be formed on
the boundary line C2 between the second region 320 and the third
region 330. FIG. 14 is a cross-sectional diagram taken along line
A-A' of FIG. 13.
[0268] The notch part 350 is the same as described in the first
embodiment. The notch part 350 is preferably any one that allows
the second and third regions 320 and 330 to be easily bent on the
boundary lines C1 and C2. The notch part 350 may be formed through
notch treatment capable of producing a difference in thickness, for
example, at the boundary lines C1 and C2. Specifically, the notch
part 350 may be selected from a folding line imprinted part formed
by pressing the boundary line C1 or C2, and a half cut part formed
by half-cutting the boundary line C1 or C2. In the present
application, the half does not mean only a "half" of the thickness
of the packaging film 300'.
[0269] The notch part 350 may be formed to a depth of, for example,
1/3 to 2/3 of the thickness of the packaging film 300' by the
folding line imprinting or half-cutting, but the present
application is not limited thereto. In addition, the notch part 350
may be continuously formed along the boundary lines C1 and C2, or
discontinuously formed at a predetermined interval.
[0270] In addition, the notch part 350 may have an elongation of 50
to 80% of an elongation before forming the notch part 350.
Particularly, when the notch treatment (e.g., the folding line
imprinting) is performed on the boundary lines C1 and C2, the
elongation of the notch part 350 may be 50 to 80% of that before
the notch treatment. For example, when it is assumed that the
elongation of the packaging film 300' is set to 100% (two times of
initial), the elongation of the notch part 350 is 50 to 80% of the
elongation of the packaging film 300' before the notch treatment,
which means 1.0 to 1.8 times of initial (that is, elongation of 50
to 80%). When such a notch part 350 exceeds the above range, for
example, it may be difficult to bend or may break.
[0271] A thickness of the packaging film 300' is not specifically
limited. The thickness of the packaging film 300' may vary
depending on a supporting strength, bending processability of each
region 310, 320 and 330, handleability in packaging, and/or
thinning of the film 300'. According to an exemplary embodiment,
the thickness of the packaging film 300' may satisfy an area of the
first region 310 and Equation 3. The thickness of the packaging
film 300' may depend on the area of the first region 310, and is
preferably, for example, in the range of approximately 50 to 500
.mu.m, 60 to 400 .mu.m, or 80 to 200 .mu.m.
[0272] In addition, the packaging film 300' may have at least one
mechanical property selected from, for example, (a) a tensile
modulus of 1,200 MPa, (b) a tensile strength of 40 MPa or more, and
(c) an elongation of 20% or more. When the packaging film 300' has
such physical properties, it can package and support the display
panel 100 and the backward diode 200 well.
[0273] The packaging film 300' preferably has small strain for high
supporting strength, fixing strength and/or durability. The
packaging film 300' preferably has a strain (E) according to
Equation 4 of, for example, 5% or less.
[0274] In addition, referring to FIG. 13, the third region 330 may
have an overlap prevented part 360. That is, when the third region
330 is bent to be adhered to the bottom surface 203 of the backward
diode 200, an overlap prevented part 360 may be formed in the third
region 330 not to overlap adjacent third regions 330.
[0275] The overlap prevented part 360 may be selected from, for
example, a notched part 361 cut at a predetermined angle (.theta.).
Here, the angle (.theta.) of the notched part 361 may be, for
example, 15 to 85 degrees, or 30 to 60 degrees, and preferably, 30
degrees or more, or 45 degrees or more. Due to such a notched part
361, the overlap with an adjacent third region 330 may be
prevented. In the present application, the angle (.theta.) of the
notched part 361 means an inclined angle made between an elongation
line (a) and the side surface of the third region 360 based on the
elongation line (a) elongated in a straight line direction from the
second region 320 as shown in FIG. 13.
[0276] FIG. 15 shows another example of the overlap prevented part
360. Referring to FIG. 15, the overlap prevented part 360 may be
selected from a cut part 362 cut out in a predetermined length (L)
and removed. Here, the length (L) of the cut part 362 may be, for
example, larger than or the same as a width (W.sub.330) of an
adjacent third region 330. The overlap with the adjacent third
region 330 may be prevented by such a cut part 362.
[0277] At least the first region 310 of the regions 310, 320 and
330 of the packaging film 300' has light transmittance
(transparency). The first region 310 may have, for example, a light
transmittance of 80% or more, preferably, for example, 90% or more,
95% or more, or 98% or more.
[0278] In addition, the bottom surface of the first region 310,
that is, a surface (a lower surface in the drawing) in contact with
the display panel 100, may have a ribbed surface in some cases. Due
to such a ribbed surface, after packaging, fusion between the first
region 310 and the display panel 100 may be prevented. Preferably,
referring to FIG. 11, fusion between the bottom surface (the lower
surface in the drawing) of the first region 310 and the top surface
(the upper surface in the drawing) of the upper polarizing plate
140 may be prevented due to the ribbed surface. The ribbed surface
may be formed through various methods, which are the same as
explained in the first embodiment.
[0279] According to an exemplary embodiment, an optical layer or
another functional layer may be formed on at least one selected
from the top surface (upper part in the drawing) and the bottom
surface (lower part in the drawing) of the first region 310.
Particularly, at least one functional layer selected from, for
example, a polarizing layer, a light diffusion layer, a viewing
angle compensation layer, a retardation layer, an anti-reflection
layer, an anti-glare layer and a protective film for protecting
these may be formed on the top and/or bottom surface(s) of the
first region 310. Such a functional layer may be stacked on the
first region 310, or may be directly formed on a surface of the
first region 310 as a separate member. For example, the polarizing
layer may be formed by adhering a light diffusing film to the first
region 310, and the anti-reflection layer may be formed by coating
an anti-reflective material on the first region 310. In another
example, the anti-glare layer may be directly formed on an upper
surface of the first region 310 through surface treatment such as
haze treatment.
[0280] The packaging film 300' may include at least a polarizing
layer formed on the first region 310 according to an exemplary
embodiment. According to another exemplary embodiment, the
packaging film 300' may include at least a polarizing layer formed
on the first region 310, and a pressure-sensitive adhesive layer
formed on the polarizing layer. Here, the pressure-sensitive
adhesive layer may include the pressure-sensitive adhesive
composition described in the first embodiment, thereby having the
physical properties described in the first embodiment. In addition,
a releasing paper may be adhered to the pressure-sensitive adhesive
layer. The releasing paper may be any one that can protect the
pressure-sensitive adhesive layer without specific limitation, and
may be, for example, a resin film or paper having
releasability.
[0281] Meanwhile, at least the second region 320 among the second
and third regions 320 and 330 may have light impermeability. That
is, the second region 320 is any one that can prevent light leakage
to a side surface since the second region 320 has light
impermeability. The second region 320 may have light transmittance
of, for example, 10% or less, 5% or less, 1% or less, 0.1% or less,
or 0%. According to a more particular embodiment, at least the
second flap 322 of the first and second flaps 321 and 322 of the
second region 320 preferably has light impermeability. In this
case, it is preferable that the backward diode 200 be an optical
diode 200A.
[0282] For light impermeability, the second region 320 may include,
for example, at least one light leakage preventing layer selected
from a light shielding layer and a reflective layer, and the light
leakage preventing layer may be formed at least on the second flap
322. In addition, the third region 330 may selectively have light
impermeability.
[0283] The light shielding layer may be formed, for example, by
coating a light shielding material on the second region 320. In
addition, the reflective layer may be formed, for example, by
coating a reflective material on the second region 320. The
materials constituting each of the light shielding layer and the
reflective layer are not specifically limited, and are the same as
described in the first embodiment.
[0284] In addition, according to an exemplary embodiment, in at
least the second region 320 of the regions 310, 320 and 330, a
moisture blocking barrier layer for preventing penetration of
external moisture may be formed. Specifically, the packaging film
300' also has the moisture blockage by itself, but to effectively
block moisture, the barrier layer may be further formed in the
second region 320.
[0285] It is preferable that the barrier layer be able to prevent
the penetration of external moisture into the display panel 100. To
this end, the barrier layer may be formed at a location
corresponding to at least the first flap 321 in the second region
320, and may have impermeability to a gas such as air, in addition
to the moisture impermeability (moisture blockage) to prevent
penetration of a gas such as external air, in addition to blocking
moisture such as humidity.
[0286] The barrier layer is not specifically limited, as long as it
at least has moisture blockage. The barrier layer may be formed on
at least one selected from an inner surface of the second region
320 and an outer surface of the second region 320. Such a barrier
layer may include, for example, at least one selected from a
moisture blocking resin layer, a metal thin film, and a deposition
layer.
[0287] The moisture blocking resin layer may be, for example, a
film layer formed by adhering a moisture blocking resin film to the
second region 320 or the side surface 102 of the display panel 100,
or a resin coating layer formed by coating a moisture blocking
resin composition on the second region 320 or the side surface 102
of the display panel 100.
[0288] The resin composition constituting the moisture blocking
resin layer, a metal constituting a metal thin film, and an oxide
constituting a deposition layer are not specifically limited, and
are the same as described in the first embodiment.
[0289] Referring to FIG. 16, a light impermeable part 314 may be
formed at an edge of the first region 310. As shown in FIG. 16, the
first region 310 may have a light permeable (transparent) main
region 312, and a light impermeable part 314 along a circumference
of the main region 312. It is preferable that the light impermeable
part 314 have light impermeability (light leakage blockage), and be
the same as described in the first embodiment. The light
impermeable part 314, as described in the first embodiment, may be
selected from, for example, a printed layer formed by being printed
with a light impermeable paint. Moreover, the light impermeable
part 314 may be selected from the light shielding layer and the
reflective layer as described above.
[0290] When the light impermeable part 314 is formed at the edge of
the first region 310 as described above, light leakage to the side
surface may be totally prevented. Since the second region 320 has
light impermeability, the light leakage to the side surface is
prevented, but for example, in the bending process of the packaging
film 300', the packaging film 300' may not be exactly bent at the
boundary lines C1 and C2, and may have allowance in some cases,
thereby causing light leakage to the side surface. In addition, the
first region 310 is lopsided in the packaging by the packaging film
300', and thus the edge of the first region 310 is placed on the
side surface 202 of the optical diode 200A, resulting in the light
leakage to the side surface. In such a case, as the light is
blocked by the light impermeable part 314, the light leakage to the
side surface may not be totally prevented. A width (W.sub.314) and
a thickness of the light impermeable part 314 are not specifically
limited, and are the same as described in the first embodiment.
[0291] In addition, referring to FIG. 17, according to an exemplary
embodiment, the first region 310 may include a projecting part 315
from which the second region 320 does not extend. Particularly, as
shown in FIG. 17, the second region 320 extends from the first
region 310, not from a vertex 310a of the first region 310, to have
a step difference 316, and thus the first region 310 may include
the projecting part 315. That is, the vertex 310a of the first
region 310 may project.
[0292] When the projecting part 315 is included as described above,
that is, the projecting part 315 from which the second region 320
does not extend is included in the first region 310, a stress may
be prevented while the second region 320 is bent. Depending on the
mechanical properties or thickness of the packaging film 300', as
shown in FIG. 13, when there is no projecting part 315 having a
projecting vertex 310a, a stress may be applied to the vertex 310a
of the first region 310 when the second region 320 is bent, and
thus the separation phenomenon may occur around the vertex 310a.
However, when the projecting part 315 is included, such a
separation phenomenon may be prevented.
[0293] According to the second embodiment of the present
application described above, an improved display device is
embodied. As the display panel 100 and a backward diode 200 are
fixed through packaging by the packaging film 300', for example, a
bezel region is minimized. That is, since the use of a molding
frame to fix the display panel 100 and the backward diode 200 is
excluded, a bezel-free display device having almost no bezel may be
embodied.
[0294] In addition, consumption of too much time and damage to the
optical diode 200A, which can occur in handling and assembly of the
backward diode 200, for example, the optical diode 200A on a film
(or sheet), may be prevented. Moreover, the display panel 100 and
the backward diode 200 are packaged by the packaging film 300',
thereby preventing the permeability of external moisture or air. In
addition, the optical diode 200A is packaged by the packaging film
300' to have sealability, thereby preventing the light leakage
phenomenon.
[0295] Hereinafter, Examples and Comparative Examples will be
illustrated. Here, the following Comparative Examples are merely
provided for comparison with Examples, and are not excluded from
the scope of the present application.
Examples 1 and 2 and Comparative Examples 1 and 2
[0296] A display panel and a back-side module (equipped with a BLU)
embodying a 24-inch monitor were prepared and packaged with a PC
film. Here, the film had various thicknesses according to Examples
and Comparative Examples. Particularly, in Examples 1 and 2, films
satisfying Equations 1 and 2 had thicknesses of 38 .mu.m (Example
1) and 75 .mu.m (Example 2), respectively. In addition, in
Comparative Examples 1 and 2, films not satisfying Equation 3 had
thicknesses of 25 .mu.m (Comparative Example 1) and 250 .mu.m
(Comparative Example 2), respectively.
T [.mu.m]=100.times.S [m.sup.2]+a [Equation]
[0297] Here, T is a thickness (.mu.m) of the PC film, S is a panel
area (0.165 m.sup.2) of a monitor, and a is a number from 15 to
130.
[0298] After the packaged monitor was installed to be inclined
approximately 10 degrees toward a wall, and maintained at
60.degree. C. for 24 hours, a degree of drooping a display panel of
the monitor was evaluated. In addition, during packaging, it was
evaluated whether there were separated parts between the monitor
and the film. The results of this are shown in Table 1.
TABLE-US-00001 TABLE 1 <Results for evaluating degree of
drooping and separation phenomenon> Comparative Comparative
Category Example 1 Example 2 Example 1 Example 2 Thickness 38 .mu.m
75 .mu.m 25 .mu.m 250 .mu.m of PC film Area of 0.165 m.sup.2 0.165
m.sup.2 0.165 m.sup.2 0.165 m.sup.2 24-inch monitor Degree of None
None Drooping None drooping (2 mm or after more) monitor
installation Separation None None None Generation phenomenon of
separated part
[0299] As shown in Table 1, it was seen that, in Examples 1 and 2
in which the relationship between a thickness and an area satisfied
the above Equation, no drooping phenomenon or separation phenomenon
occurred after the monitor was installed. However, it was seen
that, in Comparative Example 1 that did not satisfy the above
Equation and had a thickness that was too small compared to the
area of the monitor, a drooping phenomenon occurred, and in
Comparative Example 2 in which the thickness was too large, no
drooping phenomenon occurred, but a separated part was
generated.
Examples 3 and 4 and Comparative Example 3
[0300] Various kinds of films were prepared according to Examples
3, and 4, and Comparative Example 3, and strains (E) were first
measured according to the following Equation. Here, each of the
films according to Examples and Comparative Examples had a size of
60 mm.times.25 mm (width.times.length) and a thickness of 125
.mu.m, and thus the films had the same size and thickness. The
films were classified into a PC film (Example 3), a PET film
(Example 4), and a polyethylene (PE) film (Comparative Example
3).
E (%)=[(L2-L1)/L1].times.100 [Equation]
[0301] Here, L1 is the initial length of a film (60 mm), and L2 is
a length extending after the film was maintained for 24 hours at
80.degree. C. under a load of 3 kg.
[0302] Afterward, an LCD panel for embodying a 55-inch LCD TV and a
back-side module (equipped with an BLU) were prepared, and packaged
with each of the films according to Examples 3 and 4 and
Comparative Example 3. In addition, the packaged LCD TV was
installed to be inclined to a wall at an angle of 10 degrees and
maintained at 60.degree. C. for 24 hours, and then a degree to
which the LCD panel projected forward was evaluated. Here, the
degrees of projection were detected by 10 persons with the naked
eye, and when one or none of the 10 persons detected the
projection, it was indicated as "good," and when at least two of
the 10 persons detected the projection, it was indicated as "fail."
The results are shown in Table 2.
TABLE-US-00002 TABLE 2 <Results for evaluating strain>
Comparative Categories Example 3 Example 4 Example 3 Kind of film
PC film PET film PE film (125 .mu.m) (125 .mu.m) (125 .mu.m)
Extending length 0.83 mm 0.32 mm 5 mm [L2] (80.degree. C., load of
3 kg) Strain [E] 1.4% 0.5% 8.3% Projection degree, Good Good Fail
after installation (Detected by (Detected by (Detected by
(60.degree. C., after none of 10 none of 10 3 of 10 24 hours)
persons) persons) persons)
[0303] As shown in Table 2, in Examples 3 and 4 using the films
having low strains (E), it was seen that, after the installation on
the wall, the projection phenomenon did not occur.
[0304] Meanwhile, the following Examples and Comparative Examples
are exemplary Experimental Examples for a pressure-sensitive
adhesive layer. In the following Examples and Comparative Examples,
methods of measuring physical properties are as follows.
[0305] [Measurement Methods]
[0306] 1. Room Temperature Storage Modulus
[0307] A coated sample was cut to a size of 15 cm.times.25 cm
(width.times.length), a PC film was removed by peeling. In
addition, the sample was placed on a parallel plate of a dynamic
pressure-sensitive adhesion measuring device, a gap was adjusted,
normal and torque were set to zero, stabilization of normal force
was identified, and then a room temperature storage modulus was
measured. A particular measuring device and measuring conditions
are as follows. [0308] Measuring device: ARES-RDA, TA Instruments
Inc. with forced convection oven [0309] Measuring conditions [0310]
geometry: 8 mm parallel plate [0311] gap: around 1 mm [0312] test
type: dynamic strain frequency sweep [0313] strain=5.0[%] [0314]
temperature: room temperature (25.degree. C.) [0315] initial
frequency: 0.1 rad/s, final frequency: 100 rad/s
[0316] 2. Separation Phenomenon
[0317] A degree of separation between the PC film and the
pressure-sensitive adhesive layer was observed with a microscope
after a coated sample having a size of 15 cm.times.25 cm
(width.times.length) was put into a constant temperature/constant
humidity container at 60.degree. C. and a humidity of 90% for 240
hours. When there was no separation, it was indicated as "good,"
and when the separation occurred, it was indicated as
"separated."
[0318] 3. Dislocated Distance
[0319] A coated sample was cut to a size of 25 cm.times.25 cm
(width.times.length) and maintained at a room temperature
(approximately 15.degree. C.) and 80.degree. C. under a load of 1
kgf for 4 hours, and a dislocated distance between the PC film and
the pressure-sensitive adhesive layer was evaluated using a
microscope.
[0320] 4. Peeling Strength (Pressure-Sensitive Adhesive
Strength)
[0321] A coated sample was cut to a size of 15 cm.times.25 cm
(width.times.length), and peeling strength (adhesive strength) was
evaluated with respect to an adhesive surface between the PC film
and the pressure-sensitive adhesive layer was evaluated using a
texture analyzer (TA) at room temperature, a peeling angle of 180
degrees and a peeling rate of 30 mm/min.
Examples 5 to 8 and Comparative Examples 4 to 6
[0322] An acrylic pressure-sensitive adhesive resin was synthesized
with components and in contents shown in Table 3, a curing agent
was mixed, and the resulting mixture was coated on a PC film and
cured, thereby forming a pressure-sensitive adhesive layer.
[0323] A room temperature storage modulus, a separation phenomenon
and a dislocated distance (at room temperature and 80.degree. C.)
of the coating sample were evaluated, and the results are shown in
Table 3.
TABLE-US-00003 TABLE 3 <Results for evaluating characteristics
of pressure-sensitive adhesive layer> Comparative Comparative
Comparative Categories Example 5 Example 6 Example 7 Example 8
Example 4 Example 5 Example 6 Pressure- EHA/MA/AA EHA/MA/AA
EHA/MA/AA EHA/MA/AA EHA/MA/AA EHA/MA/AA BA/AA sensitive 65/25/10
65/25/10 68/25/7 68/25/7 65/25/10 68/25/7 96/4 adhesive resin
(parts by weight) Mw 1,700,000 1,450,000 1,800,000 1,430,000
760,000 760,000 1,750,000 Curing agent 0.015 0.015 0.015 0.015
0.015 0.1 0.015 (parts by weight) G' 8.4 8.3 7.9 6.8 4.1 4.8 5.2
Degree of 56% 49% 58% 46% 4.5% 82% 71% crosslinking (%) Separation
Good Good Good Good Good Separated Separated Dislocated 0 0 0 0 1.5
mm 0 0.5 mm distance (room temperature) Dislocated 0.41 0.48 0.62
0.76 Dislocated 0.43 1.7 mm distance and (80.degree. C.) detached
EHA: 2-ethylhexyl acrylate MA: methyl acrylate AA: acrylic acid BA:
butyl acrylate Mw: weight average molecular weight of
pressure-sensitive adhesive resin Curing agent: epoxy curing agent,
based on 100 parts by weight of pressure-sensitive adhesive resin
G': room temperature storage modulus (.times.10.sup.5
dyn/cm.sup.2)
[0324] As shown in Table 3, it was seen that the physical
properties were changed according to a room temperature storage
modulus (G'), a content of the curing agent and a crosslinking
agent, and the samples according to Examples had no separation
after being maintained at a high temperature/high humidity
(60.degree. C./90%) for a long time, and a dislocated distance at
room temperature and 80.degree. C. of less than 1.0 mm, thereby
exhibiting excellent cohesive strength.
Examples 9 to 12 and Comparative Examples 7 to 9
[0325] An acrylic pressure-sensitive adhesive resin was synthesized
with components and in contents shown in Table 4, a curing agent
was mixed, and the resulting mixture was coated on a PC film and
cured, thereby forming a pressure-sensitive adhesive layer.
[0326] A room temperature storage modulus, peeling strength
(pressure-sensitive adhesive strength), a separation phenomenon and
a dislocated distance (at room temperature and 80.degree. C.) of
the coating sample were evaluated, and the results are shown in
Table 4.
TABLE-US-00004 TABLE 4 <Results for evaluating characteristics
of pressure-sensitive adhesive layer> Comparative Comparative
Comparative Categories Example 9 Example 10 Example 11 Example 12
Example 7 Example 8 Example 9 Pressure- EHA/MA/AA BA/MA/AA
BA/MA/HBA BA/IBOA/MA/HBA BA/HBA BA/AA BA/AA sensitive 65/25/10
68/25/7 58/40/2 58/20/18/2 99/1 90/10 96/4 adhesive resin (parts by
weight) Mw 1,450,000 1,450,000 1,200,000 1,150,000 1,700,000
1,800,000 1,750,000 Curing 0.015 0.015 -- -- -- 0.015 0.015 agent a
(parts by weight) Curing -- -- 0.2 0.2 0.1 -- -- agent b (parts by
weight) G' 8.3 8.3 9.2 7.6 4.1 8.2 5.2 Peeling 1.55 0.86 1.32 1.63
0.16 0.43 0.25 strength (kgf/cm) Separation Good Good Good Good
Separated Separated Separated Dislocated 0 0 0 0 0.6 mm 0 0.5 mm
distance (room temperature) Dislocated 0.48 mm 0.48 mm 0.32 mm 0.35
mm 1.8 mm 0.43 mm 1.7 mm distance (80.degree. C.) EHA: 2-ethylhexyl
acrylate MA: methyl acrylate AA: acrylic acid BA: butyl acrylate
HBA: hydroxy butyl acrylate IBOA: isobornyl (meth)acrylate Mw:
weight average molecular weight of pressure-sensitive adhesive
resin Curing agent (a): epoxy curing agent, based on 100 parts by
weight of pressure-sensitive adhesive resin Curing agent (a):
isocyanate curing agent, based on 100 parts by weight of
pressure-sensitive adhesive resin G': room temperature storage
modulus (.times.10.sup.5 dyn/cm.sup.2)
[0327] As shown in Table 4, it was seen that the samples according
to Examples had no separation after being maintained at high
temperature/high humidity (60.degree. C./90%) for a long time, and
a dislocated distance at room temperature and 80.degree. C. of less
than 0.5 mm, thereby exhibiting excellent cohesive strength.
Examples 13 to 16 and Comparative Examples 10 to 13
[0328] An acrylic pressure-sensitive adhesive resin was synthesized
with components and in contents shown in Table 5, a curing agent
was mixed, and the resulting mixture was coated on a PC film and
cured, thereby forming a pressure-sensitive adhesive layer.
[0329] A room temperature storage modulus, peeling strength
(pressure-sensitive adhesive strength), separation and a dislocated
distance (at room temperature and 80.degree. C.) of the coating
sample were evaluated, and the results are shown in Table 5.
TABLE-US-00005 TABLE 5 <Results for evaluating characteristics
of pressure-sensitive adhesive layer> Example Example Example
Example Comparative Comparative Comparative Comparative Categories
13 14 15 16 Example 10 Example 11 Example 12 Example 13 Pressure-
BA/HBA BA/AA EHA/MA/AA EHA/MA/AA BA/HBA BA/AA EHA/MA/AA EHA/MA/AA
sensitive 99/1 94/6 65/25/10 68/25/7 99/1 94/6 65/25/10 68/25/7
adhesive resin (parts by weight) Mw 1,700,000 1,760,000 1,120,000
1,160,000 1,700,000 1,760,000 1,120,000 1,160,000 P 12 12 12 12 0 0
0 0 Curing 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 agent G' 1.7 .times.
10.sup.6 6.5 .times. 10.sup.6 7 .times. 10.sup.6 4.5 .times.
10.sup.6 4.7 .times. 10.sup.5 6.7 .times. 10.sup.5 8.3 .times.
10.sup.5 6.8 .times. 10.sup.5 Separation Good Good Good Good
Separated Separated Good Good Dislocated 0 0 0 0 0.2 mm 0 0 0
distance (room temperature) Dislocated 0.17 mm 0.16 mm 0.12 mm 0.15
mm 1.8 mm 0.43 mm 0.8 mm 1.1 mm distance (80.degree. C.) BA: butyl
acrylate AA: acrylic acid EHA: 2-ethylhexyl acrylate MA: methyl
acrylate HBA: hydroxy butyl acrylate Mw: weight average molecular
weight of pressure-sensitive adhesive resin P: multifunctional
acrylate (tris[2-acryloyloxy)ethyl] isocyanurate) was used as
trifunctional acrylate), based on 100 parts by weight of
pressure-sensitive adhesive resin Curing agent: isocyanate curing
agent, based on 100 parts by weight of pressure-sensitive adhesive
resin G': room temperature storage modulus(dyn/cm.sup.2)
[0330] As shown in Table 5, it was seen that the samples according
to Examples had no separation after being maintained at high
temperature/high humidity (60.degree. C./90%) for a long time, and
a dislocated distance at room temperature and 80.degree. C. of less
than 0.2 mm, thereby exhibiting excellent cohesive strength.
[0331] According to the present application, an improved display
device can be embodied. For example, a bezel region can be
minimized. In addition, in manufacture (assembly) of the display
device, damage to components can be prevented, and the process can
be simplified.
[0332] While the invention has been shown and described with
reference to certain exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the scope of
the invention as defined by the appended claims.
* * * * *