U.S. patent application number 11/028109 was filed with the patent office on 2006-03-23 for reflective coding panel and reflective coding lcd.
This patent application is currently assigned to Hannstar Display Corporation. Invention is credited to Wei-Chou Chen, Kei-Hsiung Yang.
Application Number | 20060061724 11/028109 |
Document ID | / |
Family ID | 36073555 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060061724 |
Kind Code |
A1 |
Chen; Wei-Chou ; et
al. |
March 23, 2006 |
Reflective coding panel and reflective coding LCD
Abstract
The present invention provides a reflective coding panel and a
liquid crystal display. The liquid crystal display includes a
panel, a reflective coding layer formed on the panel, and a
polarizing plate positioned on the reflective coding layer, wherein
the reflective coding layer includes a plurality of cholesteric
liquid crystal flakes having a pitch length and an average
reflective index, and the pitch length multiplied by the average
reflective index is within a range of an infrared ray
wavelength.
Inventors: |
Chen; Wei-Chou; (Hsinchu
City, TW) ; Yang; Kei-Hsiung; (Taoyuan City,
TW) |
Correspondence
Address: |
VOLPE AND KOENIG, P.C.
UNITED PLAZA, SUITE 1600
30 SOUTH 17TH STREET
PHILADELPHIA
PA
19103
US
|
Assignee: |
Hannstar Display
Corporation
Taipei
TW
|
Family ID: |
36073555 |
Appl. No.: |
11/028109 |
Filed: |
January 3, 2005 |
Current U.S.
Class: |
349/176 ;
349/12 |
Current CPC
Class: |
G06F 3/03542 20130101;
G06F 3/0321 20130101; G02F 1/13338 20130101; G02F 1/13718 20130101;
G02F 2203/11 20130101 |
Class at
Publication: |
349/176 ;
349/012 |
International
Class: |
C09K 19/02 20060101
C09K019/02; G02F 1/1335 20060101 G02F001/1335 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2004 |
TW |
093128770 |
Claims
1. A liquid crystal display, comprising: a panel; a reflective
coding layer formed on said panel; and a polarizing plate
positioned on said reflective coding layer, wherein said reflective
coding layer comprises a plurality of cholesteric liquid crystal
flakes having a pitch length and an average reflective index, and
said pitch length multiplied by said average reflective index is
within a range of an infrared ray wavelength.
2. The liquid crystal display according to claim 1, wherein said
cholesteric liquid crystal flakes are evenly dispersed in said
reflective coding layer via a medium.
3. The liquid crystal display according to claim 2, wherein said
medium comprises one of a volatile solvent, an ink, and a
paint.
4. The liquid crystal display according to claim 1, wherein said
reflective coding layer is formed on said panel by one selected
from a group consisting of an inkjet printing, a screen printing
and a relief printing.
5. The liquid crystal display according to claim 1, wherein said
infrared ray wavelength is ranged from 700 nm to 1700 nm.
6. The liquid crystal display according to claim 1, wherein said
infrared ray wavelength is ranged from 910 nm to 940 nm.
7. A panel, comprising: a substrate; and a reflective coding layer
formed on said substrate, wherein said reflective coding layer
comprises a plurality of cholesteric liquid crystal flakes having a
pitch length and an average reflective index, and said pitch length
multiplied by said average reflective index is within a range of an
infrared ray wavelength.
8. The panel according to claim 7, wherein said substrate is a
transparent substrate.
9. The panel according to claim 7, wherein said substrate is a
polarizing plate.
10. The panel according to claim, 7, wherein said cholesteric
liquid crystal flakes are evenly dispersed in said reflective
coding layer via a medium.
11. The panel according to claim 10, wherein said medium comprises
one of a volatile solvent, an ink, and a paint.
12. The panel according to claim 7, wherein said reflective coding
layer is formed on said panel by one selected from a group
consisting of an inkjet printing, a screen printing and a relief
printing.
13. The panel according to claim 7, wherein said infrared ray
wavelength is ranged from 700 nm to 1700 nm.
14. The panel according to claim 7, wherein said infrared ray
wavelength is ranged from 910 nm to 940 nm.
15. A touch panel, comprising: a substrate; and a reflective coding
layer patterned on said substrate, wherein said reflective coding,
layer absorbs an infrared ray but passes invisible light for
displaying a specific pattern.
16. The panel according to claim 15, wherein said substrate is a
transparent substrate.
17. The panel according to claim 15, wherein said reflective coding
layer is patterned on said panel by one selected from a group
consisting of an inkjet printing, a screen printing and a relief
printing.
18. The panel according to claim 15, wherein said infrared ray
wavelength is ranged from 700 nm to 1700 nm.
19. The panel according to claim 15, wherein said infrared ray
wavelength is ranged from 910 nm to 940 nm.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a panel and a liquid crystal
display, and more particularly to a reflective coding panel and a
reflective coding liquid crystal display.
BACKGROUND OF THE INVENTION
[0002] Currently, the touch input devices are widely used.
According to the conventional touch input technologies, the touch
input devices include sensors based on a resistance and sensors
based on a capacitance, i.e. the touched position on the touch
input device is identified by measuring the electrical potential
changes via a circuit. Recently, the optical touch input technology
is developed, i.e. the touched position is identified by
identifying the optical images. For the optical touch input device,
the information can be entered by writing on a specific coding
arrangement via a light pen, wherein the specific coding
arrangement is fabricated on the substrate of the optical touch
input device. The coding arrangement is exposed to the light
emitted from the light pen, and then the light is reflected to the
image-detecting system. Then, the coding is obtained by identifying
the detected images, so that the optical touch input is
effected.
[0003] The cholesteric liquid crystal has a structure similar to
the cholesterol molecule. The cholesteric liquid crystal is made up
of spirally oriented stick-like "nematic liquid crystals", wherein
"chiral molecules" are added into the "nematic liquid crystals",
and molecules in the different layers of the cholesteric liquid
crystal orient at a slight angle relative to each other, so that
the cholesteric liquid crystal has a spiral structure.
[0004] Due to the optical activity and the spiral structure of the
cholesteric liquid crystals, the light passing through the
cholesteric liquid crystals is split into the right-circularly
polarized wave and the left-circularly polarized wave. The 50% of
the light with the optical activity identical to that of the
cholestreic liquid crystals is reflected. Accordingly, the
cholesteric liquid crystals are widely used duo to the high
reflection thereof. For example, U.S. Pat. No. 6,753,044 B2
discloses a coloring media including cholesteric liquid crystal
flakes has the improved reflection characteristics of the red,
green and blue colors. And the U.S. Pat. No. 6,727,967 B2 discloses
a half-transmission color liquid crystal display, wherein a phase
difference plate and a liquid-crystal layer are provided between a
polarizing plate and a cholesteric liquid crystal layer. In the
U.S. Pat. No. 6,727,967 B2, when the liquid crystal display device
functions as a reflective liquid crystal display, light entering
through the polarizing plate is reflected by the cholesteric liquid
crystal layer; however, when the liquid crystal display device
functions as a transmission liquid crystal display, light from the
backlight passes through the cholesteic liquid crystal layer, and
thereby the brightness and the color density of the liquid crystal
display device are improved.
[0005] Up to now, the brightness, contrast, the reaction time and
the cost of the liquid crystal display stilled should be improved.
The present invention provides a reflective coding panel and a
reflective coding liquid crystal display, wherein the optical touch
input technology and the cholesteric liquid crystals are integrated
into a panel or a display, so that the reflective coding panel and
the reflective coding liquid crystal display of the present
invention are touch input devices with a great reflection.
SUMMARY OF THE INVENTION
[0006] It is an aspect of the present invention to provide a
reflective coding liquid crystal display, which is formed by
integrating the optical touch input technology and has optical
characteristics of the cholesteric liquid crystals. The reflective
coding liquid crystal display includes a panel, a reflective coding
layer formed on the panel, and a polarizing plate positioned on the
reflective coding layer, wherein the reflective coding layer
comprises a plurality of cholesteric liquid crystal flakes having a
pitch length and an average reflective index, and the pitch length
multiplied by the average reflective index is same as the
wavelength of reflected light within a range of an infrared ray. In
addition, the reflective coding layer also could be a material for
absorbing the infrared ray but passing the visible light passing
therethrough.
[0007] It is another aspect of the present invention to provide a
reflective coding panel, which is formed by integrating the optical
touch input technology and has optical characteristics of the
cholesteric liquid crystals. The panel includes a substrate and a
reflective coding layer formed on the substrate, wherein the
reflective coding layer comprises a plurality of cholesteric liquid
crystal flakes having a pitch length and an average reflective
index, and the pitch length multiplied by the average reflective
index is within a range of an infrared ray wavelength. In addition,
the reflective coding layer also could be a material for absorbing
the infrared ray but passing the visible light passing
therethrough.
[0008] Preferably, the substrate is a transparent substrate.
[0009] Preferably, the substrate is a glass substrate, a color
filter substrate or a polarizing plate.
[0010] The above aspects and advantages of the present invention
will become more readily apparent to those ordinarily skilled in
the art after reviewing the following detailed description and
accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1(a) is a schematic view illustrating the reflective
coding liquid crystal display according to the first embodiment of
the present invention;
[0012] FIG. 1(b) is a schematic view illustrating the touch input
liquid crystal display according to the first embodiment of the
present invention;
[0013] FIG. 2(a) is a schematic view illustrating the reflective
coding liquid crystal display according to the second embodiment of
the present invention;
[0014] FIG. 2(b) is a schematic view illustrating the touch input
liquid crystal display according to the second embodiment of the
present invention;
[0015] FIG. 3(a) is a schematic view illustrating the reflective
coding panel according to the third embodiment of the present
invention; and
[0016] FIG. 3(b) is a schematic view illustrating the touch input
panel according to the third embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The invention is described more specifically with reference
to the following embodiments. It is to be noted that the following
descriptions of preferred embodiments of this invention are
presented herein for the purpose of illustration and description
only; it is not intended to be exhaustive or to be limited to the
precise form disclosed.
[0018] Please refer to FIG. 1(a), which is a schematic view
illustrating the reflective coding liquid crystal display 1
according to the first embodiment of the present invention.
[0019] The reflective coding liquid crystal display 1 includes a
first substrate 11, a second substrate 12, a liquid crystal layer
13 disposed between the first substrate 11 and the second substrate
12, a first polarizing plate 14 disposed under the first substrate
11, a reflective coding layer 15 disposed above the second
substrate 12, and a second polarizing plate 16 disposed on the
reflective coding layer 15.
[0020] The first substrate 11 and the second substrate 12 can be
transparent substrates or the color filter substrates. The liquid
crystal layer 13 consists of liquid crystal molecules. The
reflective coding layer 15 includes a plurality of cholesteric
liquid crystal molecules and a medium, and is fromed on the second
substrate 2 by one of inkjet printing, screen printing or relief
printing. The printed patterns on the reflective coding layer 15
are dependent on the coding arrangement, which is required. The
medium can be an ink, a paint or a volatile solvent for the
cholesteric liquid crystal flakes being evenly dispersed therein to
be further encoded and printed. The cholesteric liquid crystal
flakes have a pitch length and an average reflective index. In
accordance with the present invention, the pitch length multiplied
by the average reflective index is within a range of an infrared
ray wavelength (700 nm-300 k nm). Preferably, the pitch length
multiplied by the average reflective index is ranged from 700 nm to
1700 nm. More preferably, the pitch length multiplied by the
average reflective index is ranged from 910 nm to 940 nm. It means
that the infrared ray with the wavelength from 910 nm to 940 nm can
be reflected by the reflective coding liquid crystal display 1. In
addition, the reflective coding layer 15 also could be a material
for absorbing the infrared ray but passing the visible light
passing therethrough. For example, the material can be SDA7775,
SDA7779, SDA4850 or SDA8737 (H. W. Sand Corp.).
[0021] Please refer to FIG. 1(b). According to the present
invention, since the infrared ray with the wavelength from 910 nm
to 940 nm can be reflected by the reflective coding liquid crystal
display 1, a light pen 17 can be applied to the reflective coding
liquid crystal display 1 for emitting the infrared ray and
detecting the images, wherein the light emitted from the light pen
to the reflective coding layer is reflected to the image detection
system, and then according to the different brightness among the
reflected infrared rays, the image is detected and identified, so
that the position having such coding is obtained. It is
advantageous to avoid the visible light absorbed by the coding
patterns, influencing the brightness of the display. Certainly, the
reflective coding liquid crystal display 1 with a light pen 7
function as an optical touch input device. Furthermore, the
reflective coding liquid crystal display 1 has the cholesteric
liquid crystal flakes 151 with the high reflection, so that the
reflective coding liquid crystal display 1 has not only the great
effects on providing the light source with great reflectivity and
power-saving, but also high brightness.
[0022] Please refer to FIG. 2(a), which a schematic view
illustrating the reflective coding liquid crystal display 2
according to the second preferred embodiment of the present
invention.
[0023] The reflective coding liquid crystal display 2 includes a
first substrate 21, a second substrate 22, a liquid crystal layer
23 disposed between the first substrate 21 and the second substrate
22, a first polarizing plate 24 disposed under the first substrate
21, a second polarizing plate 25 disposed above the second
substrate 22, and a reflective coding layer 26 disposed on the
second polarizing plate 25.
[0024] The first substrate 21 and the second substrate 22 can be
transparent substrates or color filter substrates. The liquid
crystal layer 23 consists of liquid crystal molecules. The
reflective coding layer 26 includes a plurality of cholesteric
liquid crystal molecules 261 evenly dispersed in a medium, and the
reflective coding layer 26 is formed on the second polarizing plate
25 by inkjet printing, screen printing or relief printing. The
printed patterns on the reflective coding layer 26 are dependent on
the coding arrangement, which is required. The medium can be an
ink, a paint or a volatile solvent for the cholesteric liquid
crystal flakes being evenly dispersed therein to be further encoded
and printed. According to the present invention, the cholesteric
liquid crystal flake 261 has a pitch length and an average
reflective index, and the pitch length multiplied by the average
reflective index is within a range of an infrared ray wavelength
(700 nm-300 k nm). The preferable infrared ray wavelength is ranged
from 700 nm to 1700 nm. Most preferably, the infrared ray
wavelength is ranged from 910 nm to 940 nm. Therefore, the infrared
ray with the wavelength from 910 nm to 940 nm can be reflected by
the reflective coding liquid crystal display 2. In addition, the
reflective coding layer 26 also could be a material for absorbing
the infrared ray but passing the visible light passing
therethrough. For example, the material can be SDA7775, SDA7779,
SDA4850 or SDA8737 (H. W. Sand Corp.).
[0025] Please refer to FIG. 2(b). According to the present
invention, since the infrared ray with the wavelength from 910 nm
to 940 nm can be reflected by the reflective coding liquid crystal
display 2, a light pen 27 can be applied to the reflective coding
liquid crystal display 2 for emitting the infrared ray and
detecting the images, wherein the light emitted from the light pen
to the reflective coding layer is reflected to the image detection
system, and then according to the different brightness among the
reflected infrared rays, the image is detected and identified, so
that the position having such coding is obtained. It is
advantageous to avoid the visible light absorbed by the coding
patterns, influencing the brightness of the display. Certainly, the
reflective coding liquid crystal display 2 with a light pen 27
functions as an optical touch input device. Furthermore, the
reflective coding liquid crystal display 2 has the cholesteric
liquid crystal flakes 261 with the high reflection, so that the
reflective coding liquid crystal display 1 has not only the great
effects on providing the light source with great reflectivity and
power-saving, but also high brightness.
[0026] Please refer to FIG. 3(a), which a schematic view
illustrating the reflective coding panel 3 according to the third
preferred embodiment of the present invention. The reflective
coding panel 3 includes a substrate 31 and a reflective coding
layer 32 disposed on the substrate 31.
[0027] The substrate 31 can be a transparent substrate, a glass
substrate, a color filter substrate or a polarizing plate. The
reflective coding layer 32 consists of cholesteric liquid crystal
flakes 321 evenly disposed in a medium, and is formed on the
substrate 32 by inkjet printing, screen printing or relief
printing. The printed patterns on the reflective coding layer 32
are dependent on the coding arrangement, which is required. The
medium can be an ink, a paint, or a volatile solvent for the
cholesteric liquid crystal flakes being evenly dispersed therein to
be further encoded and printed. According to the present invention,
the cholesteric liquid crystal flake 321 has a pitch length and an
average reflective index, and the pitch length multiplied by the
average reflective index is within a range of an infrared ray
wavelength (700 nm-300 k nm). The preferable infrared ray
wavelength is ranged from 700 nm to 1700 nm. Most preferably, the,
infrared ray wavelength is ranged from 910 nm to 940 nm. Therefore,
the infrared ray with the wavelength from 910 nm to 940 nm can be
reflected by the reflective coding panel 3. In addition, the
reflective coding layer 32 also could be a material for absorbing
the infrared ray but passing the visible light passing
therethrough. For example, the material can be SDA7775, SDA7779,
SDA4850 or SDA8737 (H. W. Sand Corp.).
[0028] Please refer to FIG. 3(b). According to the present
invention, since the infrared ray with the wavelength from 910 nm
to 940 nm can be reflected by the reflective coding panel 3, a
light pen 33 can be applied to the reflective coding panel 3 for
emitting the infrared ray and detecting the images, wherein the
light emitted from the light pen to the reflective coding layer is
reflected to the image detection system, and then according to the
different brightness among the reflected infrared rays, the image
is detected and identified, so that the position having such coding
is obtained. It is advantageous to avoid the visible light absorbed
by the coding patterns, influencing the brightness of the display.
Certainly, the reflective coding panel 3 with a light pen 33
functions as an optical touch input device. Furthermore, the
reflective coding panel 3 has the cholesteric liquid crystal flakes
321 with the high reflection, so that the reflective coding panel 3
has not only the great effects on providing the light source with
great reflectivity and power-saving, but also high brightness.
[0029] Accordingly, the optical touch input technology and the
cholesteric liquid crystal molecules are integrated in the panel of
the present invention, and thereby the touch input liquid crystal
display and panel with great reflection are provided. Certainly,
the present invention has the industrial applicability.
[0030] While the invention has been described in terms of what is
presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention needs not be
limited to the disclosed embodiment. On the contrary, it is
intended to cover various modifications and similar arrangements
included within the spirit and scope of the appended claims which
are to be accorded with the broadest interpretation so as to
encompass all such modifications and similar structures.
* * * * *