U.S. patent application number 14/842652 was filed with the patent office on 2015-12-24 for backlight assembly and liquid crystal display having the same.
The applicant listed for this patent is SAMSUNG DISPLAY CO., LTD.. Invention is credited to Jae-Chang CHOI, Seong-Sik CHOI.
Application Number | 20150370006 14/842652 |
Document ID | / |
Family ID | 43879039 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150370006 |
Kind Code |
A1 |
CHOI; Jae-Chang ; et
al. |
December 24, 2015 |
BACKLIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY HAVING THE SAME
Abstract
Provided are a backlight assembly with improved heat
dissipation, and a liquid crystal display (LCD) having such a
backlight assembly. The backlight assembly includes: a light guide
plate; a light source unit disposed on a side of the light guide
plate; an intermediate housing covering an upper surface of the
light source unit; and a lower housing coupled to the intermediate
housing to accommodate the light guide plate and the light source
unit, wherein the lower housing includes: a light source
unit-fixing frame to which the light source unit is fixed, the
light source unit-fixing frame contacting an inner surface of the
intermediate housing; and a body portion disposed under the light
guide plate and coupled to the light source unit-fixing frame.
Inventors: |
CHOI; Jae-Chang; (Yongin-si,
KR) ; CHOI; Seong-Sik; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG DISPLAY CO., LTD. |
Yongin-City |
|
KR |
|
|
Family ID: |
43879039 |
Appl. No.: |
14/842652 |
Filed: |
September 1, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12906971 |
Oct 18, 2010 |
9140849 |
|
|
14842652 |
|
|
|
|
Current U.S.
Class: |
362/611 |
Current CPC
Class: |
G02B 6/009 20130101;
G02F 1/133608 20130101; G02F 1/133603 20130101; G02B 6/0068
20130101; G02B 6/0091 20130101 |
International
Class: |
F21V 8/00 20060101
F21V008/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2009 |
KR |
10-2009-0099303 |
Claims
1. A backlight assembly comprising: a light guide plate; a light
source unit disposed on a side of the light guide plate; an
intermediate housing covering an upper surface of the light source
unit; and a lower housing coupled to the intermediate housing to
accommodate the light guide plate and the light source unit,
wherein the lower housing comprises: a light source unit-fixing
frame to which the light source unit is fixed, the light source
unit-fixing frame contacting an inner surface of the intermediate
housing; and a body portion disposed under the light guide plate
and coupled to the light source unit-fixing frame.
Description
[0001] This application is a continuation application of U.S.
patent application Ser. No. 12/906,971 filed on Oct. 18, 2010,
which claims priority to Korean Patent Application No.
10-2009-0099303 filed on Oct. 19, 2009 in the Korean Intellectual
Property Office, the disclosure of which is incorporated herein by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to liquid crystal display
(LCD) panels, and more particularly, to an LCD backlight assembly
with improved heat dissipation.
[0004] 2. Description of the Related Art
[0005] Liquid crystal displays (LCDs) are among the most widely
used types of flat panel displays. Generally, an LCD includes a
pair of substrates having electrodes, and a liquid crystal layer
interposed between the substrates. In an LCD, voltages are applied
to electrodes to generate an electric field. The electric field
determines the alignment of liquid crystal molecules of a liquid
crystal layer, thereby controlling the amount of light that passes
through the liquid crystal layer. As a result, a desired image is
displayed on the LCD.
[0006] An LCD, which is typically a passive light-emitting device,
includes a liquid crystal panel that displays an image, as well as
a backlight assembly that provides light to the liquid crystal
panel. Backlight assemblies can be classified into direct-type
backlight assemblies and edge-type backlight assemblies according
to the position of light sources.
[0007] Recent efforts have focused on making LCDs more compact,
lighter, and with better color reproducibility. In particular, some
research efforts have focused on the use of point light sources,
such as light-emitting diodes (LEDs), as light sources for
backlights. However, when point light sources such as LEDs are used
in backlights, it is often desirable to efficiently remove
generated heat.
SUMMARY OF THE INVENTION
[0008] Aspects of the present invention provide a backlight
assembly with improved heat dissipation.
[0009] Aspects of the present invention also provide a liquid
crystal display (LCD) having a backlight assembly with improved
heat dissipation.
[0010] However, aspects of the present invention are not restricted
to the one set forth herein. The above and other aspects of the
present invention will become more apparent to one of ordinary
skill in the art to which the present invention pertains by
referencing the detailed description of the present invention given
below.
[0011] According to an aspect of the present invention, there is
provided a backlight assembly including: a light guide plate; a
light source unit disposed on a side of the light guide plate; an
intermediate housing covering an upper surface of the light source
unit; and a lower housing coupled to the intermediate housing to
accommodate the light guide plate and the light source unit,
wherein the lower housing includes: a light source unit-fixing
frame to which the light source unit is fixed, the light source
unit-fixing frame contacting an inner surface of the intermediate
housing; and a body portion disposed under the light guide plate
and coupled to the light source unit-fixing frame.
[0012] According to another aspect of the present invention, there
is provided a liquid crystal display including: a liquid crystal
panel configured to display an image; a light guide plate disposed
under the liquid crystal panel; a light source unit disposed on a
side of the light guide plate; an intermediate housing covering an
upper surface of the light source unit; and a lower housing coupled
to the intermediate housing to accommodate the light guide plate
and the light source unit, wherein the lower housing includes: a
light source unit-fixing frame to which the light source unit is
fixed, the light source unit-fixing frame contacting an inner
surface of the intermediate housing; and a body portion disposed
under the light guide plate and coupled to the light source
unit-fixing frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other aspects and features of the present
invention will become more apparent by describing in detail
exemplary embodiments thereof with reference to the attached
drawings, in which:
[0014] FIG. 1 is an exploded perspective view of a liquid crystal
display (LCD) according to a first exemplary embodiment of the
present invention;
[0015] FIG. 2 is a cross-sectional view of the LCD taken along the
line A-A' of FIG. 1;
[0016] FIG. 3 is a perspective view of a light source unit-fixing
frame according to the first exemplary embodiment of the present
invention;
[0017] FIG. 4 is a perspective view of a main portion of the light
source unit-fixing frame according to the first exemplary
embodiment of the present invention;
[0018] FIG. 5 is a perspective view showing the arrangement
relationship between the light source unit-fixing frame and a light
source unit according to the first exemplary embodiment of the
present invention;
[0019] FIG. 6 is a perspective view of a body portion of a lower
housing according to the first exemplary embodiment of the present
invention;
[0020] FIG. 7 is a perspective view showing the arrangement
relationship between the body portion and the light source
unit-fixing frame of the lower housing according to the first
exemplary embodiment of the present invention;
[0021] FIG. 8 is an exploded perspective view of an LCD according
to a second exemplary embodiment of the present invention;
[0022] FIG. 9 is a perspective view of a light source unit-fixing
frame according to the second exemplary embodiment of the present
invention;
[0023] FIG. 10 is a perspective view of a main portion of the light
source unit-fixing frame according to the second exemplary
embodiment of the present invention;
[0024] FIG. 11 is a perspective view of a body portion of a lower
housing according to the second exemplary embodiment of the present
invention;
[0025] FIG. 12 is a perspective view showing the arrangement
relationship between the body portion and the light source
unit-fixing frame of the lower housing according to the second
exemplary embodiment of the present invention;
[0026] FIG. 13 is an exploded perspective view of an LCD according
to a third exemplary embodiment of the present invention;
[0027] FIGS. 14 through 18 are views showing light source
unit-fixing frames included in LCDs according to another exemplary
embodiments of the present invention; and
[0028] FIGS. 19 and 20 are views showing lower housings included in
LCDs according to another exemplary embodiments of the present
invention.
[0029] Like reference numerals refer to corresponding parts
throughout the drawings. Also, it is understood that the depictions
in the figures are diagrammatic and not necessarily to scale.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Advantages and features of the present invention and methods
of accomplishing the same may be understood more readily by
reference to the following detailed description of exemplary
embodiments and the accompanying drawings. The present invention
may, however, be embodied in many different forms and should not be
construed as being limited to the embodiments set forth herein.
Rather, these embodiments are provided so that this disclosure will
be thorough and complete and will fully convey the concept of the
invention to those skilled in the art, and the present invention
will only be defined by the appended claims. In some embodiments,
well-known processing processes, well-known structures, and
well-known technologies will not be specifically described in order
to avoid ambiguous interpretation of the present invention. Like
reference numerals refer to like elements throughout the
specification.
[0031] Spatially relative terms, such as "below," "beneath,"
"lower," "above," "upper," and the like, may be used herein for
ease of description to describe one device or element's
relationship to another device(s) or element(s) as illustrated in
the drawings. It will be understood that the spatially relative
terms are intended to encompass different orientations of the
device in use or operation in addition to the orientation depicted
in the drawings. For example, if the device in the figures is
turned over, elements described as "below" or "beneath" other
elements or features would then be oriented "above" the other
elements or features. Thus, the exemplary term "below" can
encompass both an orientation of above and below. The device may be
otherwise oriented and the spatially relative descriptors used
herein interpreted accordingly.
[0032] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated components, steps,
operations, and/or elements, but do not preclude the presence or
addition of one or more other components, steps, operations,
elements, and/or groups thereof.
[0033] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0034] Hereinafter, a backlight assembly and a liquid crystal
display (LCD) according to a first exemplary embodiment of the
present invention will be described in detail with reference to
FIGS. 1 through 7.
[0035] FIG. 1 is an exploded perspective view of an LCD according
to the first exemplary embodiment of the present invention. FIG. 2
is a cross-sectional view of the LCD taken along the line A-A' of
FIG. 1.
[0036] Referring to FIGS. 1 and 2, an LCD according to the first
exemplary embodiment broadly includes a liquid crystal panel
assembly 10 and a backlight assembly 20.
[0037] The liquid crystal panel assembly 10 includes a liquid
crystal panel 110, liquid crystals (not shown), a driving
integrated circuit (IC) 116, a tape carrier package 117, a printed
circuit board (PCB) 118, and an upper housing 180. The liquid
crystal panel 110 includes a first substrate 111, a second
substrate 112, and polarizers 113 and 114 which are respectively
disposed on surfaces of the first and second substrates 111 and
112. The second substrate 112 faces the first substrate 111, the
polarizer 113 is disposed under the first substrate 111, and the
polarizer 114 is disposed on the second substrate 112. The first
substrate 111 includes gate lines (not shown), data lines (not
shown) and pixel electrodes, and the second substrate 112 includes
a black matrix, color filters, and a common electrode. The color
filters or the common electrode may alternatively be formed on the
first substrate 111, depending on the type of the liquid crystal
panel 110. Various driving parts for processing driving signals may
be mounted on the PCB 118.
[0038] The upper housing 180 prevents components of the liquid
crystal panel assembly 10 from moving out of place, and protects
the liquid crystal panel 110 or the backlight assembly 20 from
damage due to external impacts. The upper housing 180 may be shaped
like a frame, composed of a flat portion and sidewall portions
which extend perpendicular to the flat portion. The upper housing
180 may cover the whole of the liquid crystal panel 110 and the
backlight assembly 20, or cover the whole of the liquid crystal
panel 110 and only part of the backlight assembly 20. A window is
formed in an upper surface of the upper housing 180 to expose the
liquid crystal panel 110 for viewing. The liquid crystal panel 110
formed by stacking the above flat plate-shaped substrates is placed
on an intermediate housing 150 which will be further described
below.
[0039] The backlight assembly 20 includes light source units 130, a
light guide plate (LGP) 140, one or more optical sheets 120, a
reflective sheet 160, the intermediate housing 150, and a lower
housing 200 which includes a light source unit-fixing frame 220 and
a body portion 210.
[0040] Each of the light source units 130 may include a plurality
of point light sources 132, and an alignment board 131 on which the
point light sources 132 are mounted. The light source units 130
according to the first exemplary embodiment of the present
invention are disposed on inner surfaces of two opposing sidewalls
of the lower housing 200. For example, when the LCD is rectangular,
the light source units 130 may be disposed on both long sides of
the LCD, facing the LGP 140. However, the present invention is not
limited thereto, and the light source units 130 may also be
disposed on any one or all of four sides of the lower housing
200.
[0041] The LGP 140 is housed in the lower housing 200 such that
side surfaces of the LGP 140 face the light source units 130. When
the light source units 130 are disposed facing opposite side
surfaces of the LGP 140, light enters the LGP 140 through both side
surfaces of the LGP 140 which face the light source units 130.
[0042] The LGP 140 may have any suitable shape. For example, the
LGP can be a wedge-shaped plate or a flat plate. The LGP 140 may be
made of a light-transmitting material, for example, acrylic resin
(such as polymethyl methacrylate (PMMA)) or polycarbonate (PC).
[0043] A pattern may be formed on at least one surface of the LGP
140. For example, a diffusion pattern (not shown) may be formed on
a lower surface of the LGP 140 to help direct light exiting the LGP
140 in an upward direction.
[0044] The optical sheets 120 are disposed on an upper surface of
the LGP 140 and diffuse and/or concentrate light that is received
from the LGP 140. The optical sheets 120 may include a diffusion
sheet, a prism sheet, and a protective sheet. Of the optical sheets
120, the diffusion sheet may be located closest to the LGP 140. The
diffusion sheet may diffuse light, which is received from the LGP
140, and thus prevent the light from being concentrated in a
specific area. The prism sheet may have a predetermined array of
triangular prisms on a surface thereof. The prism sheet may be
disposed on the diffusion sheet to concentrate light from the
diffusion sheet in a direction perpendicular to the liquid crystal
panel 110. The protective sheet may be disposed on the prism sheet
to protect the upper surface of the prism sheet. In addition, the
protective sheet may further diffuse light for more uniform light
distribution.
[0045] The reflective sheet 160 is disposed between the LGP 140 and
the lower housing 200 and reflects lightback from the lower surface
of the LGP 140 toward the liquid crystal panel 110, i.e. in an
upward direction.
[0046] To be reflective, the reflective sheet 160 may be made of
one or more suitable materials, e.g., polyethylene terephthalate
(PET). In addition, a diffusion layer containing, e.g., titanium
dioxide, may be coated on a surface of the reflective sheet 160.
The reflective sheet 160 may also be made of metal such as silver
(Ag).
[0047] The intermediate housing 150 may be formed as a frame shaped
to fit along sidewalls of the lower housing 200. For example, the
intermediate housing 150 can be sized to fit over the outer and
upper surfaces of the sidewalls of the lower housing 200. The
intermediate housing 150 of the first exemplary embodiment is
disposed on the outer surfaces of the sidewalls of the lower
housing 200. The intermediate housing 150 may be coupled to the
lower housing 200 by coupling members formed in sidewalls of the
intermediate housing 150. The intermediate housing 150 and the
lower housing 200 may be coupled to each other to accommodate the
reflective sheet 160, the LGP 140, the light source units 130, and
the optical sheets 120.
[0048] The intermediate housing 150 may be a mold frame made of,
e.g., a plastic material, in order to prevent parts fixed in
position by the intermediate housing 150 from being damaged.
[0049] The lower housing 200 includes a body portion 210 and a
light source unit-fixing frame 220. The body portion 210 and the
light source unit-fixing frame 220 may be coupled to each other to
form a generally cuboid shaped box having an open top surface and a
housing space with a predetermined depth. This will be described in
further detail below.
[0050] Hereinafter, the arrangement relationship between the light
source unit-fixing frame 220 and the light source units 130 will be
described in detail with reference to FIGS. 3 through 5. FIG. 3 is
a perspective view of two portions of the light source unit-fixing
frame 220 according to the first exemplary embodiment of the
present invention. FIG. 4 is a magnified perspective view of one
portion of the light source unit-fixing frame 220 according to the
first exemplary embodiment of the present invention. FIG. 5 is a
perspective view showing the arrangement relationship between the
light source unit-fixing frame 220 and the light source units 130
according to the first exemplary embodiment of the present
invention.
[0051] Referring to FIG. 3, the light source unit-fixing frame 220
of the first embodiment is not a single continuous frame structure,
but is instead two separate parts: unit fixing frames 220a and
220b. Here, two frames 220a, 220b are shown, although alternative
embodiments can employ different numbers of such frames. The light
source unit-fixing frame 220 may dissipate heat, which is generated
by the light source units 130, out of the lower housing 200.
[0052] Referring to FIG. 4, each of the unit fixing frames 220a and
220b includes a plate 221a, and first and second support walls
222a, 226a that extend substantially perpendicular to the plate
221a.
[0053] The plate 221a includes a first plate 223a connected to the
first support wall 222a, and a second plate 224a connected to the
first plate 223a. The second plate 224a is where the body portion
210 (see FIG. 1) of the lower housing 200 is placed. The second
plate 224a is thinner than the first plate 223a. Specifically, an
upper surface of the second plate 224a may be lower than that of
the first plate 223a by a thickness of the body portion 210 (see
FIG. 1) of the lower housing 200. That is, referring to FIG. 2,
when the body portion 210 of the lower housing 200 is placed on the
second plate 224a, the upper surface of the first plate 223a may be
at the same height as an upper surface of a bottom plate of the
body portion 210. This allows the reflective sheet 160 to be placed
evenly on both the upper surface of the first plate 223a and the
upper surface of the bottom plate 211 of the body portion 210.
[0054] The first support wall 222a of the unit fixing frame 220a
extends from the plate 221a in a direction substantially
perpendicular to the plate 221a (i.e. upward, from the view of FIG.
4).
[0055] Referring to FIG. 5, one of the light source units 130 is
placed on the first support wall 222a. The point light sources 132
may be light-emitting diodes (LEDs) or any other suitable light
sources. Specifically, the point light sources 132 are mounted on a
first surface of the alignment board 131, and a second surface of
the alignment board 131 is attached to the first support wall 222a.
For example, alignment board-coupling holes 133 (see FIG. 1) may be
formed in the alignment board 131, and the second surface of the
alignment board 131 may be coupled to the first support wall 222a
by coupling members such as screws. In this case, coupling holes
225a (see FIG. 4), which correspond respectively to the alignment
board-coupling holes 133 (see FIG. 1), may be formed in the first
support wall 222a. However, the present invention is not limited
thereto. For example, the second surface of the alignment board 131
may be adhered to the first support wall 222a by a heat-dissipating
adhesive tape.
[0056] The alignment board 131 may be shaped like a rectangular
plate, as shown in FIG. 5. Alternatively, although not shown in the
drawings, the alignment board 131 may be bent in an "L" shape. In
the latter case, the alignment board 131 would include a first
portion which is placed on the plate 221a, and a second portion
which extends from the first portion to be substantially
perpendicular to the first portion and which is attached to the
first support wall 222a.
[0057] The alignment board 131 may have a circuit pattern (not
shown) which connects the point light sources 132 to each other.
The alignment board 131 may also be made of a thermally conductive
material in order to increase the dissipation of heat generated by
the point light sources 132.
[0058] Referring to FIGS. 3 through 5, the plate 221a of the light
source unit-fixing frame 220 may be generally rectangular, as
shown. The larger the area of the plate 221, the greater the heat
dissipation efficiency of the light source unit-fixing frame 220.
The area of the plate 221a can be adjusted according to factors
such as heat dissipation efficiency and the weight of the LCD. The
invention contemplates any suitable area for plate 221a.
[0059] A width of the first plate 223a (i.e., the distance to which
it extends away from the first support wall 222a) may be equal to
or greater than the sum of a thickness of the alignment board 131
and a thickness of the point light sources 132, so that the light
sources 132 do not extend over the second plate 224a. An increase
in the width of the first plate 223a may improve heat dissipation
efficiency and reduce the probability that light emitted from the
point light sources 132 will be seen at a boundary between the
first plate 223a and the second plate 224a. Specifically, light
emitted from the point light sources 132 may be seen at the
boundary between the first plate 223a and the second plate 224a due
to the step difference in height between the first plate 223a and
the second plate 224a. However, if the width of the first plate
223a is increased, the distance that light emitted from the point
light sources 132 should travel to reach the boundary between the
first plate 223a and the second plate 224a may increase, thereby
reducing the intensity of the light that reaches the boundary.
Therefore, the first plate 223a may extend a predetermined distance
from the point light sources 132, and the width of the first plate
223a may be adjusted in view of heat dissipation efficiency and the
intensity of light that reaches the boundary between the first
plate 223a and the second plate 224a.
[0060] The light source unit-fixing frame 220 contains a material
having relatively high thermal conductivity. For example, the light
source unit-fixing frame 220 may contain aluminum. The light source
unit-fixing frame 220 may be formed using any suitable methods. For
example, the light source unit-fixing frame 220 may be formed by
snap-fitting, machining, welding, or otherwise assembling the plate
221a and the first support wall 222a. For the sake of efficiency,
the light source unit-fixing frame 220 may be formed by extrusion
molding using a pre-manufactured mold. The light source unit-fixing
frame 220 may also be formed by press molding.
[0061] The second support wall 226a may be formed at an edge of the
plate 221a. The second support wall 226a may be disposed parallel
to the first support wall 222a, and supported by sidewalls of the
intermediate housing 150 once the LCD panel is assembled (see FIG.
2). The second support wall 226a, together with the first support
wall 222a, increases the rigidity of the backlight assembly 20 thus
conferring benefits such as preventing distortion of the backlight
assembly 20. In addition, the space or air gap between the second
support wall 226a and the first support wall 222a serves as an air
circulation passage, thereby enhancing the heat dissipation
function of the light source unit-fixing frame 220.
[0062] The arrangement relationship between the body portion 210
and the light source unit-fixing frame 220 of the lower housing 200
will now be described with reference to FIGS. 2, 6 and 7. FIG. 6 is
a perspective view of the body portion 210 of the lower housing 200
according to the first exemplary embodiment of the present
invention. FIG. 7 is a perspective view showing the arrangement
relationship between the body portion 210 and the light source
unit-fixing frame 220 of the lower housing 200 according to the
first exemplary embodiment of the present invention.
[0063] Referring to FIG. 6, the body portion 210 of the lower
housing 200 includes bottom plate 211 and sidewalls 212 and 213
extending from both sides of the bottom plate 211. The sidewalls
212, 213 face each other, and extend in a direction generally
perpendicular to the bottom plate 211. The body portion 210 of the
lower housing 200 may be made of a material which can both protect
the point light sources 132 from external impact and bring about a
cooling effect by distributing heat more evenly. For example, the
body portion 210 may be made of aluminum. The body portion 210 of
this embodiment is simpler in structure than even a box. More
specifically, only two sides of body portion 210 have upturned
edges, rather than four. Thus, a die for manufacturing the body
portion 210 of the lower housing 200 can be made more simply and
easily, reducing both tooling and production costs.
[0064] Referring to FIG. 7, the light source unit-fixing frame 220
is disposed on, or attached to, those sides of the bottom plate 211
of the body portion 210 on which the sidewalls 212 and 213 are not
formed. The body portion 210 and the light source unit-fixing frame
220 together form the lower housing 200 as a generally cuboid
shaped box having an open top surface.
[0065] The body portion 210 of the lower housing 200 is placed on
the light source unit-fixing frame 220. Specifically, the body
portion 210 of the lower housing 200 is placed on the upper surface
of the second plate 224a of the light source unit-fixing frame 220.
The second plate 224a and the bottom plate 211 of the body portion
210 may then be coupled to each other using various methods. For
example, lower housing-coupling holes 214 (see FIG. 6) may be
formed in the bottom plate 211 of the body portion 210, and
plate-coupling holes 227a (see FIG. 4) may be formed in the second
plate 224a. Then, the bottom plate 211 of the body portion 210 may
be coupled to the second plate 224a by screws or a caulking
material. Unlike the illustration in FIG. 7, the second plate 224a
and the bottom plate 211 of the body portion 210 may alternatively
be coupled to each other by, for example, welding.
[0066] The plate 221a of the light source unit-fixing frame 220 is
disposed under a lower surface of the bottom plate 211 of the body
portion 210 while surrounding the bottom plate 211 of the body
portion 210. Specifically, the lower surface of the bottom plate
211 of the body portion 210 may be tightly attached to the upper
surface of the second plate 224a of the light source unit-fixing
frame 220. In this embodiment, the LGP 140 is positioned within the
boxlike cavity of lower housing 200, over the body portion 210 as
well as at least the area of overlap between the body portion 210
and second plate 224a. The LGP 140 can also cover at least some of
the first plate 223a.
[0067] The above-described configuration provides a relatively
large surface area through which heat can be drawn from the light
source unit 130. In particular, the unit-fixing frame 220a can be
coupled to the light source unit 130 across the entire surface of
first support wall 222a, and body portion 210 can be coupled to
frame 220a across the entire surface of second plate 224a, as well
as the relatively narrow vertical step between surfaces 224a and
223a. These relatively large surface areas allow for more efficient
flow of heat out of the light source unit 130, through the frame
220a, and into the body portion 210. The optional presence of
additional second support wall 226a provides a further outlet for
heat from the light source unit 130. These mechanisms provide
improved dissipation of heat from light source unit 130.
[0068] Additionally, the configuration of the above embodiment
places the plate 221a in relatively close proximity to (though, in
this embodiment, not overlapping) light source unit 130, so that in
addition to facilitating conduction of heat away from unit 130, at
least some radiation from unit 130 is also transmitted directly to
plate 221a, without passing through any other components. Radiative
heat can then be dissipated by the lower housing 200. In this
manner, embodiments of the invention provide both improved
conductive pathways and radiative pathways for dissipating heat
from unit 130.
[0069] Hereinafter, a backlight assembly and an LCD according to a
second exemplary embodiment of the present invention will be
described with reference to FIGS. 8 through 12. FIG. 8 is an
exploded perspective view of the LCD according to the second
exemplary embodiment of the present invention. FIG. 9 is a
perspective view of a light source unit-fixing frame 320 according
to the second exemplary embodiment of the present invention. FIG.
10 is a perspective view of a main portion of the light source
unit-fixing frame 320 according to the second exemplary embodiment
of the present invention. FIG. 11 is a perspective view of a body
portion 310 of a lower housing 300 according to the second
exemplary embodiment of the present invention. FIG. 12 is a
perspective view showing an arrangement of the body portion 310 and
the light source unit-fixing frame 320 of the lower housing 300
according to the second exemplary embodiment of the present
invention. For simplicity, elements having the same functions as
those according to the first exemplary embodiment are indicated by
like reference numerals, and thus their description will be omitted
or simplified.
[0070] Referring to FIGS. 8 and 9, the light source unit-fixing
frame 320 of this embodiment is not a single continuous frame
structure, but is instead four separate parts. More specifically,
the unit fixing frames of this second exemplary embodiment comprise
first unit fixing frames 320a and 320b, and second unit fixing
frames 320c and 320d.
[0071] The first unit fixing frames 320a and 320b are substantially
identical to the unit fixing frames 220a and 220b of the first
exemplary embodiment shown in FIG. 3. Unlike the light source
unit-fixing frame 220 of the first embodiment, the light source
unit-fixing frame 320 of the second embodiment also includes second
unit fixing frames 320c and 320d.
[0072] Referring to FIG. 10, the second unit fixing frame 320c
includes a plate 321c and a first support wall 322c substantially
perpendicular to the plate 321c. The plate 321c may be, for
example, rectangular. The area of the plate 321c can be adjusted in
view of heat dissipation efficiency and the weight of the LCD. For
example, different thickness and width can be applied to different
area of the plate 321 to optimize the heat dissipation efficiency
and the weight of the LCD. A second support wall 326c may further
be formed at an edge of the plate 321c. The second support wall
326c may be disposed parallel to the first support wall 322c, and
supported by sidewalls of an intermediate housing 150 (see FIG.
8).
[0073] Referring to FIG. 11, the body portion 310 of the lower
housing 300 (see FIG. 8) is shaped generally as a flat plate. Like
body portion 210 of the first embodiment, body portion 310 of the
second embodiment can have a boxlike, or simpler, structure. For
example, here, body portion 310 can have two upturned edges, rather
than four. Thus, a die for manufacturing the body portion 310 of
the lower housing 300 can be fabricated more simply and easily,
reducing tooling and production costs.
[0074] Referring to FIG. 12, the four parts of the light source
unit-fixing frame 320 are affixed to the four sides of the body
portion 310 of the lower housing 300, thereby forming a generally
cuboid box having an open top surface. This forms the lower housing
300 (see FIG. 8), which has a housing space with a predetermined
depth.
[0075] The body portion 310 and the second unit fixing frames 320c
and 320d are each disposed on the upper surfaces of second plates
324a (see FIG. 9) of each of the first unit fixing frames 320a and
320b. A thickness of the plate 321c (see FIG. 10) may be equal to a
thickness of the body portion 310 of the lower housing 300, such
that the lower housing 300 (see FIG. 8) has an even housing
surface. In other words, when assembled, the upper surface of the
body portion 310 is substantially planar with the upper surfaces of
the second unit fixing frames 320c, 320d.
[0076] Referring to FIGS. 9 and 10, plate-coupling holes 327c may
be formed in the plate 321c, and in the second plate 324a.
Accordingly, the second unit fixing frame 320c (or 320d) may be
coupled to the first unit fixing frame 320a (or 320b) by methods
such as screws, caulking, or welding.
[0077] In the LCD according to the second exemplary embodiment,
heat delivered to the light source unit-fixing frame 320 can be
directly dissipated out of the lower housing 300, both through all
four of its sides, and through radiating directly onto the body
portion 310 without passing through other components, thereby
improving efficiency of heat dissipation.
[0078] Hereinafter, a backlight assembly and an LCD according to a
third exemplary embodiment of the present invention will be
described in detail with reference to FIG. 13. FIG. 13 is an
exploded perspective view of the LCD according to the third
exemplary embodiment of the present invention. For simplicity,
elements having the same functions as those according to the first
and second exemplary embodiments are indicated by like reference
numerals, and thus their description will be omitted or
simplified.
[0079] Referring to FIG. 13, a light source unit-fixing frame 420
according to the third exemplary embodiment of the present
invention may be configured as a single, continuous or integral
frame structure. Specifically, the light source unit-fixing frame
420 may be shaped as a single rectangular frame having four sides
420a through 420d. As shown in FIG. 13, each side of the light
source unit-fixing frame 420 may include a thicker support wall
extending inward from the edge of the frame, and a thinner plate
extending from that. For example, the side 420b of the light source
unit-fixing frame 420 may include a first plate 423b which is
connected to a first support wall 422b, and a second plate 424b
which is connected to the first plate 423b and is thinner than the
first plate 423b.
[0080] A flat plate-shaped body portion 410 of a lower housing 400
is affixed to the upper surface of each thinner plate (e.g., side
420b) to form the lower housing 400.
[0081] In the LCD according to the third exemplary embodiment, heat
delivered to the light source unit-fixing frame 420 can be directly
dissipated out of the lower housing 400 via conduction through
frame 420 and radiation onto body portion 410 without passing
through other components, thereby improving efficiency of heat
dissipation.
[0082] FIGS. 14 and 15 are views showing light source unit-fixing
frames 520 and 620 included in LCDs according to another exemplary
embodiment of the present invention. For ease of understanding, the
light source unit-fixing frames 520 and 620 are explained below by
comparison to the light source unit-fixing frame 220 of FIG. 3.
[0083] Referring to FIGS. 14 and 15, plates 521a and 621a of the
light source unit-fixing frames 520 and 620 have non-uniform
widths, whereas the plate 221a (see FIG. 4) of the light source
unit-fixing frame 220 (see FIG. 3) has a generally uniform
width.
[0084] The widths of the plates 521a and 621a may vary according to
distribution of heat generation. For example, the plates 521a and
621a may be wide in regions where a relatively large amount of heat
is generated, and may be narrow in regions where a relatively small
amount of heat is generated (e.g., wider in areas proximate to
light sources, narrower inbetween). If the widths of the plates
521a and 621a are increased in the regions where a relatively large
amount of heat is generated, heat generated in those regions can be
more easily dissipated out of the lower housing.
[0085] In FIG. 14, both ends of the plate 521a are wider than other
portions thereof. In FIG. 15, both ends and a middle portion of the
plate 621a are wider than other portions thereof. Although not
shown in the drawings, each of the plates 520 and 620 may have
other configurations. For example, each may be saw-toothed. That
is, portions of each of the plates 520 and 620 that correspond to
each of the point light sources 132 (see FIG. 1) may be wider than
other portions.
[0086] FIGS. 16, 17A, and 17B are views showing a light source
unit-fixing frame 720 constructed according to another exemplary
embodiment of the present invention. FIG. 17A is a cross-sectional
view of a region B shown in FIG. 16, and FIG. 17B is a
cross-sectional view of a region C shown in FIG. 16. For ease of
understanding, the light source unit-fixing frame 720 is explained
below by comparison to the light source unit-fixing frame 220 of
FIG. 3.
[0087] Referring to FIGS. 16 and 17A, a lower surface of a plate
721a of the light source unit-fixing frame 720 may have an uneven
portion 728, whereas the lower surface of the plate 221a (see FIG.
4) of the light source unit-fixing frame 220 (see FIG. 3) is
substantially even. One can observe that the uneven portion 728 has
a larger surface area than a corresponding even surface. That is,
the uneven surface of portion 728 has greater surface area than an
even surface that has the same footprint. Thus, embodiments
employing an uneven portion 728 instead of an even surface have the
capacity to dissipate more heat from the LCD.
[0088] Referring to FIGS. 17A and 17B, the generally uneven portion
728 may be formed on only part (the region B) of the lower surface
of the plate 721a. For example, the uneven portion 728 may be
formed in the region B where a relatively large amount of heat is
generated, and may not be formed in the region C where a relatively
small amount of heat is generated. Although not shown in the
drawings, the uneven portion 728 may also be formed on the entire
lower surface of the plate 721a. The invention contemplates uneven
portions 728 of any geometry, placed anywhere on frame 720.
[0089] FIG. 18 is a view showing a light source unit-fixing frame
820 included in an LCD according to another exemplary embodiment of
the present invention. For ease of understanding, the light source
unit-fixing frame 820 is explained below by comparison to the light
source unit-fixing frame 220 of FIG. 3.
[0090] Referring to FIG. 18, a groove portion 829 is formed in a
plate 821a of the light source unit-fixing frame 820. A body
portion 810 of a lower housing is inserted into this groove portion
829 coupling the two together. This eliminates or reduces the need
for coupling members (such as screws) for coupling the light source
unit-fixing frame 820 to the body portion 810.
[0091] FIG. 19 is a view showing a lower housing 900 constructed
according to another exemplary embodiment of the present invention.
The lower housing 900 is explained below, mainly by comparison to
the lower housing 400 of FIG. 13.
[0092] Referring to FIG. 19, a plate 921b of a light source
unit-fixing frame 920 has a non-uniform width, while the plate 421b
of the light source unit-fixing frame 420 (see FIG. 13) has a
substantially uniform width. As described above with reference to
the embodiments of FIGS. 14 and 15, the width of the plate 921b may
vary according to distribution of heat generation.
[0093] While the body portion 410 of the lower housing 400 is
shaped like a generally rectangular plate, the body portion 910 of
the lower housing 900 may be shaped like a generally polygonal
plate.
[0094] FIG. 20 is a view showing a lower housing 1000 constructed
according to another exemplary embodiment of the present invention.
The lower housing 1000 is explained below, mainly by comparison to
the lower housing 200 of FIG. 1.
[0095] Referring to FIG. 20, the lower housing 1000 according may
further include rigidity-reinforcing bars 1030 which are disposed
on outer surfaces of sidewalls 212 and 213 of a body portion 210,
and which are coupled to a light source unit-fixing frame 220 to
form a generally rectangular frame. The rigidity-reinforcing bars
1030 are generally rectangular bars designed to increase the
torsional rigidity and overall stiffness (e.g., resistance to any
one or more of bending, torsion, compression, and tension) of the
lower housing 1000, so as to better prevent distortion of a
backlight assembly and protect the backlight assembly from an
external impact. While the bars 1030 are shown here as generally
rectangular, the invention contemplates any shape and placement of
bars 1030 that increases the torsional and/or flexural rigidity of
lower housing 1000.
[0096] While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and detail may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims. The exemplary embodiments should be
considered in a descriptive sense only and not for purposes of
limitation.
* * * * *