U.S. patent application number 15/752345 was filed with the patent office on 2019-08-22 for display device and display method.
The applicant listed for this patent is BOE Technology Group Co., Ltd.. Invention is credited to Xiaochuan CHEN, Xue DONG, Zhongxiao LI, Haiyan WANG, Wenqing ZHAO.
Application Number | 20190258110 15/752345 |
Document ID | / |
Family ID | 58841738 |
Filed Date | 2019-08-22 |
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United States Patent
Application |
20190258110 |
Kind Code |
A1 |
LI; Zhongxiao ; et
al. |
August 22, 2019 |
Display Device And Display Method
Abstract
A display device and a display method using the same are
disclosed. The display device includes: a display panel including a
first substrate, a second substrate and a liquid crystal prism
arranged between the first substrate and the second substrate; and
a backlight source configured to emit a light which is incident
onto the second substrate at an oblique angle; wherein the liquid
crystal prism is configured to adjust a deflection angle of the
light emitted from the backlight source traveling between the first
substrate and the second substrate such that the light emitted from
the backlight source is totally-reflected at a light exit face of
the display device or exits from the light exit face of the display
device.
Inventors: |
LI; Zhongxiao; (Beijing,
CN) ; DONG; Xue; (Beijing, CN) ; CHEN;
Xiaochuan; (Beijing, CN) ; ZHAO; Wenqing;
(Beijing, CN) ; WANG; Haiyan; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOE Technology Group Co., Ltd. |
Beijing |
|
CN |
|
|
Family ID: |
58841738 |
Appl. No.: |
15/752345 |
Filed: |
August 1, 2017 |
PCT Filed: |
August 1, 2017 |
PCT NO: |
PCT/CN2017/095410 |
371 Date: |
February 13, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 2001/133357
20130101; G02F 1/133512 20130101; G02F 1/13439 20130101; G02F
1/133528 20130101; G02F 1/134309 20130101; G02F 2001/291 20130101;
G02F 2203/30 20130101; G02F 1/29 20130101; G02F 1/13362
20130101 |
International
Class: |
G02F 1/1335 20060101
G02F001/1335; G02F 1/1343 20060101 G02F001/1343 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 18, 2017 |
CN |
201710035757.8 |
Claims
1. A display device, comprising: a display panel comprising a first
substrate, a second substrate and a liquid crystal prism arranged
between the first substrate and the second substrate; and a
backlight source configured to emit a light which is incident onto
the second substrate at an oblique angle; wherein the liquid
crystal prism is configured to adjust a deflection angle of the
light emitted from the backlight source traveling between the first
substrate and the second substrate such that the light emitted from
the backlight source is totally-reflected at a light exit face of
the display device or exits from the light exit face of the display
device.
2. The display device according to claim 1, wherein the liquid
crystal prism is configured to have a first operation state in
which the light emitted by the backlight source is entirely
incident onto the light exit face of the display device at an
incident angle greater than or equal to a total reflection critical
angle after it has been deflected by the liquid crystal prism and a
second operation state in which the light emitted by the backlight
source is entirely incident onto the light exit face of the display
device at an incident angle less than the total reflection critical
angle after it has been deflected by the liquid crystal prism.
3. The display device according to claim 2, wherein the liquid
crystal prism is further configured to have a third operation state
in which one part of the light emitted by the backlight source is
incident onto the light exit face of the display device at an
incident angle greater than or equal to the total reflection
critical angle after it has been deflected by the liquid crystal
prism while the other part of the light emitted by the backlight
source is incident onto the light exit face of the display device
at an incident angle less than the total reflection critical angle
after it has been deflected by the liquid crystal prism.
4. The display device according to claim 1, wherein the backlight
source is arranged to face towards a surface of the second
substrate away from the first substrate.
5. The display device according to claim 1, wherein the liquid
crystal prism comprises a liquid crystal layer, and a first
electrode and a second electrode insulated from each other.
6. The display device according to claim 5, wherein the first
electrode and the second electrode are arranged on two opposite
sides of the liquid crystal layer respectively.
7. The display device according to claim 5, wherein the first
electrode is a planar electrode and the second electrode comprises
a plurality of strip electrodes.
8. The display device according to claim 7, wherein each of the
plurality of strip electrodes has a width of 2.5 .mu.m in a
direction parallel to a surface of the second substrate and a strip
electrode gap of 3.5 .mu.m is provided between two adjacent strip
electrodes; and the liquid crystal layer has a thickness less than
10 .mu.m.
9. The display device according to claim 1, wherein the light
emitted by the backlight source is linearly polarized.
10. The display device according to claim 1, wherein the light
emitted by the backlight source is a natural light and the display
device further comprises a polarizer sheet arranged between the
second substrate and the backlight source.
11. The display device according to claim 1, wherein a frosted film
is arranged on a surface of the first substrate away from the
second substrate.
12. The display device according to claim 1, wherein the display
panel further comprises a black matrix arranged on a surface of the
second substrate facing towards the liquid crystal prism and the
black matrix is configured to limit a light incidence region on the
second substrate for the light emitted by the backlight source.
13. The display device according to claim 12, wherein a
planarization layer is arranged between the second substrate and
the liquid crystal prism, the planarization layer covering the
black matrix which is arranged between the planarization layer and
the second substrate.
14. The display device according to claim 1, wherein the display
panel further comprises a black matrix arranged on a surface of the
second substrate away from the liquid crystal prism.
15. The display device according to claim 1, wherein the first
substrate in the display device has a greater refractive index than
external environmental medium in contact with the display
device.
16. The display device according to claim 1, wherein the light
emitted by the backlight source has an incidence angle in a range
from 55 degrees to 60 degrees when the light is incident onto the
second substrate.
17. A display method using the display device according to claim 1,
the display method comprising: directing the light emitted from the
backlight source to be incident onto the second substrate at an
oblique angle; controlling the liquid crystal prism to regulate the
deflection angle of the light emitted by the backlight source
traveling between the first substrate and the second substrate,
such that the light emitted by the backlight source is
totally-reflected at the light exit face of the display device or
exits from the light exit face of the display device.
18. The display method according to claim 17, wherein the liquid
crystal prism comprises a liquid crystal layer, a first electrode
and a second electrode, and controlling the liquid crystal prism
comprises: controlling a common voltage applied to the first
electrode and controlling a magnitude of a driving voltage applied
to the second electrode to control a deflection state of liquid
crystal in the liquid crystal layer.
19. The display method according to claim 18, further comprising:
applying a driving voltage V.sub.1 to the second electrode to make
the light emitted by the backlight source entirely exit from the
light exit face of the display device; or applying a driving
voltage V.sub.2 to the second electrode to make the light emitted
by the backlight source be entirely totally-reflected at the light
exit face of the display device; or applying a driving voltage
V.sub.3 greater than V.sub.1 but less than V.sub.2 to the second
electrode to make one part of the light emitted by the backlight
source be totally-reflected at the light exit face of the display
device and make the other part of the light emitted by the
backlight source exit from the light exit face of the display
device.
20. The display method according to claim 1, wherein the light
emitted by the backlight source has an incidence angle in a range
from 55 degrees to 60 degrees when the light is incident onto the
second substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of the Chinese Patent
Application No. 201710035757.8, filed with the State Intellectual
Property Office of China on Jan. 18, 2017, which is incorporated
herein by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
[0002] The present disclosure relates to the technical field of
liquid crystal display, and in particular, to a display device and
a display method.
Description of the Related Art
[0003] At present, liquid crystal display devices have been widely
used in people's lives.
[0004] In the conventional liquid crystal display device, the
liquid crystal is used to modulate polarization of a linearly
polarized light to change the polarization orientation of the
linearly polarized light, so as to display pictures in different
states, that is, grey scale display. Thus, in the conventional
liquid crystal display device, polarizer sheets need to be provided
on two substrates of the display panel. Unless the two polarizer
sheets cooperate with each other, the liquid crystal display device
cannot display pictures in different states.
SUMMARY
[0005] An embodiment of the present disclosure provides a display
device, including: a display panel including a first substrate, a
second substrate and a liquid crystal prism arranged between the
first substrate and the second substrate; and a backlight source
configured to emit a light which is incident onto the second
substrate at an oblique angle; wherein the liquid crystal prism is
configured to adjust a deflection angle of the light emitted from
the backlight source traveling between the first substrate and the
second substrate such that the light emitted from the backlight
source is totally-reflected at a light exit face of the display
device or exits from the light exit face of the display device.
[0006] In some embodiments, the liquid crystal prism is configured
to have a first operation state in which the light emitted by the
backlight source is entirely incident onto the light exit face of
the display device at an incident angle greater than or equal to a
total reflection critical angle after it has been deflected by the
liquid crystal prism and a second operation state in which the
light emitted by the backlight source is entirely incident onto the
light exit face of the display device at an incident angle less
than the total reflection critical angle after it has been
deflected by the liquid crystal prism.
[0007] In some embodiments, the liquid crystal prism is further
configured to have a third operation state in which one part of the
light emitted by the backlight source is incident onto the light
exit face of the display device at an incident angle greater than
or equal to the total reflection critical angle after it has been
deflected by the liquid crystal prism while the other part of the
light emitted by the backlight source is incident onto the light
exit face of the display device at an incident angle less than the
total reflection critical angle after it has been deflected by the
liquid crystal prism.
[0008] In some embodiments, the backlight source is arranged to
face towards a surface of the second substrate away from the first
substrate.
[0009] In some embodiments, the liquid crystal prism includes a
liquid crystal layer, and a first electrode and a second electrode
insulated from each other.
[0010] In some embodiments, the first electrode and the second
electrode are arranged on two opposite sides of the liquid crystal
layer respectively.
[0011] In some embodiments, the first electrode is a planar
electrode and the second electrode includes a plurality of strip
electrodes.
[0012] In some embodiments, each of the plurality of strip
electrodes has a width of 2.5 .mu.m in a direction parallel to a
surface of the second substrate and a strip electrode gap of 3.5
.mu.m is provided between two adjacent strip electrodes; and the
liquid crystal layer has a thickness less than 10 .mu.m.
[0013] In some embodiments, the light emitted by the backlight
source is linearly polarized.
[0014] In some embodiments, the light emitted by the backlight
source is a natural light and the display device further includes a
polarizer sheet arranged between the second substrate and the
backlight source.
[0015] In some embodiments, a frosted film is arranged on a surface
of the first substrate away from the second substrate.
[0016] In some embodiments, the display panel further includes a
black matrix arranged on a surface of the second substrate facing
towards the liquid crystal prism and the black matrix is configured
to limit a light incidence region on the second substrate for the
light emitted by the backlight source.
[0017] In some embodiments, a planarization layer is arranged
between the second substrate and the liquid crystal prism, the
planarization layer covering the black matrix which is arranged
between the planarization layer and the second substrate.
[0018] In some embodiments, the display panel further includes a
black matrix arranged on a surface of the second substrate away
from the liquid crystal prism.
[0019] In some embodiments, the first substrate in the display
device has a greater refractive index than external environmental
medium in contact with the display device.
[0020] In some embodiments, the light emitted by the backlight
source has an incidence angle in a range from 55 degrees to 60
degrees when the light is incident onto the second substrate.
[0021] An embodiment of the present disclosure discloses a display
method using the display device as described in any one of the
above embodiments, the display method including: directing the
light emitted from the backlight source to be incident onto the
second substrate at an oblique angle; controlling the liquid
crystal prism to regulate the deflection angle of the light emitted
by the backlight source traveling between the first substrate and
the second substrate, such that the light emitted by the backlight
source is totally-reflected at the light exit face of the display
device or exits from the light exit face of the display device.
[0022] In some embodiments, the liquid crystal prism includes a
liquid crystal layer, a first electrode and a second electrode, and
controlling the liquid crystal prism includes: controlling a common
voltage applied to the first electrode and controlling a magnitude
of a driving voltage applied to the second electrode to control a
deflection state of liquid crystal in the liquid crystal layer.
[0023] In some embodiments, the display method further includes:
applying a driving voltage V.sub.1 to the second electrode to make
the light emitted by the backlight source entirely exit from the
light exit face of the display device; or applying a driving
voltage V.sub.2 to the second electrode to make the light emitted
by the backlight source be entirely totally-reflected at the light
exit face of the display device; or applying a driving voltage
V.sub.3 greater than V.sub.1 but less than V.sub.2 to the second
electrode to make one part of the light emitted by the backlight
source be totally-reflected at the light exit face of the display
device and make the other part of the light emitted by the
backlight source exit from the light exit face of the display
device.
[0024] In some embodiments, the light emitted by the backlight
source has an incidence angle in a range from 55 degrees to 60
degrees when the light is incident onto the second substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to explain the technical solutions of embodiments
of the present disclosure or those in the prior art more
explicitly, figures required for describing the embodiments or the
prior art will below be described briefly. Apparently, the
following figures are only intended to show some of embodiments of
the present disclosure. The skilled person in the art may also
obtain other figures from those without any creative efforts.
[0026] FIG. 1 is a schematic view showing an exemplified structure
of a liquid crystal display device;
[0027] FIG. 2 is a first structural schematic view showing a
display device provided by an embodiment of the present
disclosure;
[0028] FIG. 3 is a second structural schematic view showing a
display device provided by an embodiment of the present
disclosure;
[0029] FIG. 4 is a third structural schematic view showing a
display device provided by an embodiment of the present
disclosure;
[0030] FIG. 5 is a fourth structural schematic view showing a
display device provided by an embodiment of the present
disclosure;
[0031] FIG. 6 is a first schematic view showing a linearly
polarized light traveling in a display device provided by an
embodiment of the present disclosure;
[0032] FIG. 7 is a second schematic view showing a linearly
polarized light traveling in a display device provided by an
embodiment of the present disclosure; and
[0033] FIG. 8 is a third schematic view showing a linearly
polarized light traveling in a display device provided by an
embodiment of the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE DISCLOSURE
[0034] In order that the above objects, features and advantages of
the present disclosure can become more apparent, technical
solutions in the embodiments of the present disclosure will below
be explained clearly and entirely. Apparently, the described
embodiments are only some of embodiments in the present disclosure,
instead of all of embodiments. From the embodiments of the present
disclosure, all of other embodiments derived by the skilled person
in the art without any creative efforts fall within the scope of
the present disclosure.
[0035] In accordance with a general concept, an embodiment of the
present disclosure provides a display device, including: a display
panel including a first substrate, a second substrate and a liquid
crystal prism arranged between the first substrate and the second
substrate; and a backlight source configured to emit a light which
is incident onto the second substrate at an oblique angle; wherein
the liquid crystal prism is configured to adjust a deflection angle
of the light emitted from the backlight source traveling between
the first substrate and the second substrate such that the light
emitted from the backlight source is totally-reflected at a light
exit face of the display device or exits from the light exit face
of the display device.
[0036] In addition, in the following detailed description, for
purposes of explanation, numerous specific details are set forth in
order to provide a thorough understanding of the disclosed
embodiments. It will be apparent, however, that one or more
embodiments may be practiced without these specific details. In
other instances, well-known structures and devices are
schematically shown in order to simplify the drawings.
[0037] As illustrated in FIG. 1, an exemplified liquid crystal
display in turn includes a first polarizer sheet 1, a first
substrate 2, a liquid crystal layer 3, a second substrate 4 and a
second polarizer sheet 5. A common electrode 6 is arranged on a
surface of the first substrate 2 facing towards the second
substrate 4. A pixel electrode 7 is arranged on a surface of the
second substrate 4 facing towards the first substrate 2. The first
substrate 2, the liquid crystal layer 3, the second substrate 4,
the common electrode 6 and the pixel electrode 7 constitute a
display panel.
[0038] When a natural light is incident on a surface of the second
substrate 4 away from the first substrate 2, the second polarizer
sheet 5 arranged to face towards the second substrate 4 at first
needs to convert the natural light into a linearly polarized light.
A driving voltage is applied to the pixel electrode 7 and a common
voltage is supplied to the common electrode 6. In this way, an
electrical field is formed between the pixel electrode 7 and the
common electrode 6 to drive liquid crystal in the liquid crystal
layer to deflect, so as to change the polarization of the linear
polarized light traveling in the liquid crystal layer 3. When the
polarization orientation of the linearly polarized light is
parallel to a polarization axis of the first polarizer sheet 1, the
linearly polarized light may exit from the first substrate 2 and
the first polarizer sheet 1. In contrast, when the polarization
orientation of the linearly polarized light is perpendicular to the
polarization axis of the first polarizer sheet 1, the linearly
polarized light cannot exit from the first substrate 2 and the
first polarizer sheet 1. In the exemplified liquid crystal display
device, the polarizer sheets at two substrates of the display panel
are necessary. Unless the two polarizer sheets cooperate with each
other, the liquid crystal display device cannot display pictures in
different states.
[0039] As shown in FIG. 2, an embodiment of the present disclosure
provides a display device, which includes a display panel and a
backlight source 8. The display panel includes a first substrate 2,
a second substrate 4 and a liquid crystal prism 9 arranged between
the first substrate 2 and the second substrate 4. The backlight
source 8 is configured to emit a light which is incident onto the
second substrate 4 at an oblique angle. As an example, the
backlight source 8 may be arranged to face towards a surface of the
second substrate 4 away from the first substrate 2. However, the
embodiments of the present disclosure are not limited to this. The
backlight source 8 may also be arranged in other orientations, as
long as the light emitted by it can be incident onto the second
substrate 4 at an oblique angle.
[0040] The liquid crystal prism 9 is configured to adjust a
deflection angle of the light emitted from the backlight source 8
traveling between the first substrate 2 and the second substrate 4
such that the light emitted from the backlight source 8 is
totally-reflected at a light exit face of the display device or
exits from the light exit face of the display device. The light
exit face of the display device is an interface between the first
substrate 2 and the external environmental medium in contact with
the display device. As an example, the light exit face of the
display device is a surface of the first substrate 2 away from the
second substrate 4.
[0041] In view of the above structure, the liquid crystal prism 9
may be used to control the deflection angle of the light emitted
from the backlight source 8 traveling between the first substrate 2
and the second substrate 4, so as to control magnitude of the
incidence angle when the light travels to the light exit face of
the display device. When the light entirely violates the total
reflection condition at the light exit face, the light entirely
exits from the light exit face. At that time, the display device
exhibits a bright display state. When the light entirely satisfies
the total reflection condition at the light exit face, the light
entirely is totally-reflected at the light exit face and is
reflected back to the liquid crystal prism. At that time, the
display device exhibits a dark display state. When one part of the
light satisfies the total reflection condition at the light exit
face, such part of the light can be totally-reflected at the light
exit face and the other part of the light can exit from the light
exit face. At that time, the display device exhibits a gray scale
display state between the bright display state and the dark display
state. Thus, with the display device provided by the present
disclosure, by means of deflection principle of the liquid crystal
prism to the light and the total reflection condition at the light
exit face of the display device, the display device may also
exhibit different display states without using two polarizer
sheets.
[0042] In particular, when the light emitted by the backlight
source 8 travels to the interface entirely at an incidence angle
less than a total reflection critical angle, i.e., the light
entirely violates the total reflection condition, the light exits
from the interface. At that time, the display panel has maximum
light transmission and the display device exhibits the bright
display state. When the light emitted by the backlight source 8
travels to the interface entirely at an incidence angle greater
than or equal to the total reflection critical angle, i.e., the
light entirely satisfies the total reflection condition, the light
is entirely totally-reflected at the interface and is reflected
back to the liquid crystal prism 9. At that time, the light
transmission of the display panel becomes zero and the display
device exhibits the dark display state. When the light emitted by
the backlight source 8 travels to the interface with only part of
the light having the incidence angle greater than or equal to the
total reflection critical angle, this part of the light may be
totally-reflected, back to the liquid crystal prism 9, at the
interface. The incidence angle of the other part of the light is
less than the total reflection critical angle, and this part of the
light may exit from the interface. At that time, the display device
exhibits a gray scale display state between the bright display
state and the dark display state.
[0043] In an example, the liquid crystal prism 9 may be configured
to have a first operation state and a second operation state. In
the first operation state, the light emitted by the backlight
source 8 is entirely incident onto the light exit face of the
display device at an incident angle greater than or equal to a
total reflection critical angle after it has been deflected by the
liquid crystal prism 9. In the second operation state, the light
emitted by the backlight source 8 is entirely incident onto the
light exit face of the display device at an incident angle less
than the total reflection critical angle after it has been
deflected by the liquid crystal prism 9. When the liquid crystal
prism 9 is in the first operation state, the display device
exhibits the dark display state. In contrast, when the liquid
crystal prism 9 is in the second operation state, the display
device exhibits the bright display state.
[0044] As an example, the liquid crystal prism 9 may further be
configured to have a third operation state. In the third operation
state, one part of the light emitted by the backlight source 8 is
incident onto the light exit face of the display device at an
incident angle greater than or equal to the total reflection
critical angle after it has been deflected by the liquid crystal
prism 9 while the other part of the light emitted by the backlight
source 8 is incident onto the light exit face of the display device
at an incident angle less than the total reflection critical angle
after it has been deflected by the liquid crystal prism 9. When the
liquid crystal prism 9 is in the third operation state, the display
device exhibits the grey scale display state between the bright
display state and the dark display state.
[0045] Thus, by means of the display device provided by the
embodiments, using the deflection principle of the liquid crystal
prism 9 to the light in combination with the total reflection
condition at the interface between the first substrate 2 and the
external environmental medium, even if no corresponding polarizer
sheets are arranged at the first substrate 2, the display device
may also exhibit different display states.
[0046] As an example, the light emitted by the backlight source 8
may be a natural light, or may be a linearly polarized light with
single polarization orientation.
[0047] As illustrated in FIG. 3, as an example, the liquid crystal
prism 9 in the display panel may include a liquid crystal layer 3,
and a first electrode 11 and a second electrode 12 insulated from
each other.
[0048] As an example, the first electrode 11 and the second
electrode 12 may both be arranged at one side of the liquid crystal
layer 3 facing towards the first substrate 2; or the first
electrode 11 and the second electrode 12 may both be arranged at
one side of the liquid crystal layer 3 facing towards the second
substrate 4; or, the first electrode 11 and the second electrode 12
may be arranged on two opposite sides of the liquid crystal layer 3
respectively.
[0049] When the first electrode 11 and the second electrode 12 are
arranged on the same side of the liquid crystal layer 3, the first
electrode 11 and the second electrode 12 may be arranged in the
same layer or in different layers respectively.
[0050] The first electrode 11 may for example be a common
electrode. The second electrode 12 may for example be a pixel
electrode.
[0051] In an example, in accordance with the specific structure of
the liquid crystal prism 9, when a driving voltage is applied to
the second electrode 12 and a common voltage is applied to the
first electrode 11, an electrical field may be generated between
the second electrode 12 and the first electrode 11, so as to drive
the liquid crystal in the liquid crystal layer 3 to deflect. The
deflected liquid crystal can cause the light traveling in the
liquid crystal layer 3 to deflect, so as to change the incidence
angle of the light on the interface between the first substrate 2
and the external environmental medium. In this way, the driving
voltage applied to the second electrode 12 may be varied to change
the deflection states of the liquid crystal, so as to change the
deflection angle of the light traveling in the liquid crystal layer
3 to regulate the incidence angle of the light on the interface to
be greater than, equal to or less than the total reflection
critical angle.
[0052] In an example, the first electrode 11 is a planar electrode
and the second electrode 12 includes a plurality of strip
electrodes.
[0053] As an example, each of the strip electrodes has a width
d.sub.1 of 2.5 .mu.m in a direction parallel to a surface of the
second substrate 4 and a strip electrode gap d.sub.2 of 3.5 .mu.m
is provided between two adjacent strip electrodes; and the liquid
crystal layer 3 in the liquid crystal prism 9 has a thickness
d.sub.3 less than 10 .mu.m.
[0054] The deflection state of the whole liquid crystal in the
liquid crystal layer 3 may be equivalent to a liquid crystal
deflection equivalent interface. By reasonably designing the width
d.sub.1 of each of the strip electrodes, the strip electrode gap
d.sub.2 and the thickness d.sub.3 of the liquid crystal layer 3,
the liquid crystal deflection equivalent interface may be
optimized, to further control the deflection angle of the linearly
polarized light better.
[0055] It should be noted that the above given specific numerical
values of d.sub.1, d.sub.2 and d.sub.3 are only optional numerical
values, instead of limiting their respective practical numerical
values. From the display principle corresponding to the display
device in the embodiment, as long as the reasonable numerical
values are designed for them, the display device can exhibit
different display states.
[0056] It should be noted that the first substrate 2 in the display
device should have a greater refractive index than the external
environmental medium. If the first substrate 2 and the second
substrate 4 are both glass substrates and the light exit face of
the display device is an interface between the first substrate 2
and the air, the refractive index of the first substrate 2 should
be greater than the refractive index of the air. For example, if
the refractive index of the air is 1.0, the refractive index of the
first substrate 2 may be 1.5.
[0057] As an example, the light emitted by the backlight source 8
is incident onto the second substrate 4 at an oblique incidence
angle in a range from 55 degrees to 60 degrees.
[0058] As shown in FIG. 4, as an example, since the light traveling
in the liquid crystal prism 9 is desired to be a linearly polarized
light, a polarizer sheet 10 for converting the natural light into
the linearly polarized light needs to be arranged between the
second substrate 4 and the backlight source 8 when the light
emitted by the backlight source 8 is the natural light.
[0059] As an example, the polarizer sheet 10 may be also replaced
by a polarizer layer. The polarizer layer may in particular be
arranged on the side of the second substrate 4 facing towards the
backlight source 8, or may be arranged on the side of the second
substrate 4 away from the backlight source 8. The polarizer layer
may for example be a wire grid structure.
[0060] It should be understood that, when the light emitted by the
backlight source 8 is a linearly polarized light with single
polarization orientation, the polarizer sheet 10 arranged between
the second substrate 4 and the backlight source 8 is not necessary
and the linearly polarized light emitted by the backlight source 8
may be directly incident onto the second substrate 4.
[0061] As shown in FIG. 5, as an example, a frosted film 13 may
also be arranged on a surface of the first substrate 2 away from
the second substrate 4. The frosted film 13 is configured to
disperse a collimated light emitted from the first substrate 2, to
enhance a visual angle of the picture displayed by the display
device.
[0062] In an example, the frosted film 13 may be adhered to a
surface of the first substrate 2, for example, only a periphery of
the frosted film 13 is adhered to the surface of the first
substrate 2, and the intermediate region of the frosted film 13 and
the intermediate region of the first substrate 2 are separated by
an air layer therebetween. In this case, it is not intended to
limit the refractive index of the frosted film 13.
[0063] In another example, the frosted film 13 may also be fully
adhered to the surface of the first substrate 2. In this case, the
refractive index of the frosted film 13 is desired to be close to
the refractive index of the air as much as possible, such that the
refractive index of the first substrate 2 of the display device is
greater than the refractive index of the frosted film 13, to ensure
that the light may be totally-reflected at the surface of the first
substrate 2.
[0064] As an example, a color filter layer 14 for filtering light
may also be arranged between the first substrate 2 and the liquid
crystal prism 9. The color filter layer 14 may make different
sub-pixels to exhibit different colors respectively.
[0065] Typically, in the conventional display panel, the black
matrix is only arranged at the first substrate 2. The black matrix
at this position is intended to block and absorb the external
incident light and to avoid color mixing of adjacent pixels, so as
to prevent the external light from irradiating TFT devices on the
second substrate 4 directly or indirectly by reflection or
scattering and thereby prevent degrading off state characteristics
of the TFT devices.
[0066] In the display device provided by the embodiment, as an
example, the black matrix 15 may also be arranged at the second
substrate 4. The black matrix 15 at this position is arranged to
correspond to an opening region of the pixel, to limit a light
incidence region for the light emitted by the backlight source 8,
to further limit the light exit region of the light at the
interface between the first substrate 2 and the external
environmental medium, to prevent the exit light from entering the
adjacent sub-pixels so as to avoid cross color. When the light
emitted by the backlight source 8 is totally-reflected at the
interface between the first substrate 2 and the external
environmental medium, the black matrix 15 may also absorb the light
reflected into the liquid crystal prism 9 to prevent the light from
being reflected again.
[0067] As an example, the black matrix 15 may be arrange at the
surface of the second substrate 4 facing towards the liquid crystal
prism 9 and may also be arranged at the surface of the second
substrate 4 away from the liquid crystal prism 9.
[0068] When the black matrix 15 is arranged at the surface of the
second substrate 4 facing towards the liquid crystal prism 9, as
the black matrix 15 has an uneven surface, a planarization layer 16
which is smooth and covers the black matrix 15 may also be arranged
between the second substrate 4 and the liquid crystal prism 9, so
as to achieve better contact with the second electrode 12. The
black matrix 15 may be arranged between the planarization layer 16
and the second substrate 4.
[0069] It should be understood that, when the backlight source 8 in
the display device is a strip backlight source 8, the black matrix
15 at the second substrate 4 will not be necessary as the strip
backlight source 8 may be limited by its own light emitting
region.
[0070] Based on the above specific structure of the display device,
in order to explain the process for propagating the corresponding
linearly polarized light in the bright display state, the dark
display state and the gray scale display state between the bright
display state and the dark display state more explicitly, the
embodiments of the present disclosure will be described below with
reference to FIG. 6 to FIG. 8.
[0071] It should be noted that, in FIG. 6 to FIG. 8, the upper
straight line represents the interface between the first substrate
2 and the external environmental medium and the lower straight line
represents the surface of the second substrate 4 away from the
first substrate 2.
[0072] When the display device exhibits the bright display state,
as shown in FIG. 6, taking two incident linearly polarized lights
as an example, .omega.' is an incidence angle at which a first
linearly polarized light is incident onto the second substrate 4;
.sigma.' is an incidence angle at which a second linearly polarized
light is incident onto the second substrate 4; and
.omega.'<.sigma.'. In process for practical light propagation,
when the light is incident onto the second substrate 4 from the
external environmental medium, it may be refracted at the incident
surface of the second substrate 4. .omega. is an angle of the first
linearly polarized light after it has been refracted at the surface
of the second substrate 4. .sigma. is an angle of the second
linearly polarized light after it has been refracted at the surface
of the second substrate 4.
[0073] When the driving voltage is not applied to the second
electrode 12, the liquid crystal molecules in the liquid crystal
layer 3 are not deflected. The first linearly polarized light and
the second linearly polarized light both travel along a straight
line in the liquid crystal layer 3 and exit from the interface
between the first substrate 2 and the external environmental
medium. At that time, the display panel has maximum light
transmission and the display device exhibits the bright display
state.
[0074] All of layers between the first substrate 2 and the second
substrate 4 are parallel to each other, thus, the first linearly
polarized light and the second linearly polarized light have the
same exit angles from the first substrate 2 as the incidence angles
of them onto the second substrate 4.
[0075] When the display device exhibits the dark display state, as
shown in FIG. 7, taking two incident linearly polarized lights as
an example, .theta.' is an incidence angle at which a third
linearly polarized light is incident onto the second substrate 4;
.beta.' is an incidence angle at which a fourth linearly polarized
light is incident onto the second substrate 4; and
.theta.'<.beta.'. In process for practical light propagation,
when the light is incident onto the second substrate 4 from the
external environmental medium, it may be refracted at the incident
surface of the second substrate 4. .theta. is an angle of the third
linearly polarized light after it has been refracted at the surface
of the second substrate 4. .beta. is an angle of the fourth
linearly polarized light after it has been refracted at the surface
of the second substrate 4. When the maximum driving voltage is
applied to the second electrode 12, the liquid crystal molecules
are deflected by a maximum deflection extent. The liquid crystal
deflection equivalent interface is shown in FIG. 7.
[0076] Due to the effects of the deflected liquid crystal
molecules, the third linearly polarized light and the fourth
linearly polarized light are deflected at the liquid crystal
deflection equivalent interface. After they are deflected, the
angle at which the third linearly polarized light travels is
increased to .theta..sub.1 from .theta. and the angle at which the
fourth linearly polarized light travels is increased to
.beta..sub.1 from .beta..
[0077] Because the driving voltage applied to the second electrode
12 is sufficiently large, it can ensure the liquid crystal
molecules to deflect to large extent, so as to ensure the third
linearly polarized light and the fourth linearly polarized light to
deflect by larger angle. For example, the third linearly polarized
light and the fourth linearly polarized light may both be deflected
by not less than 5 degrees. In this circumstance, the incident
angle .theta..sub.1 of the deflected third linearly polarized light
at the interface between the first substrate 2 and the external
environmental medium is greater than the critical angle for the
total reflection at the interface. Since .beta.>.theta., the
incident angle .beta..sub.1 of the deflected fourth linearly
polarized light at the interface is also greater than the critical
angle for the total reflection at the interface. In this
circumstance, the deflected third linearly polarized light and the
deflected fourth linearly polarized light are totally-reflected
back to the liquid crystal layer 3 at the interface. At that time,
the light transmission of the display panel becomes zero and the
display device exhibits the dark display state.
[0078] When the display device exhibits the gray scale display
state between the bright display state and the dark display state,
as shown in FIG. 8, taking three incident linearly polarized lights
as an example, .gamma.' is an incidence angle at which a fifth
linearly polarized light is incident onto the second substrate 4;
.delta.' is an incidence angle at which a sixth linearly polarized
light is incident onto the second substrate 4; .epsilon.' is an
incidence angle at which a seventh linearly polarized light is
incident onto the second substrate 4; and
.gamma.'<.delta.'<.epsilon.'. In process for practical light
propagation, when the light is incident onto the second substrate 4
from the external environmental medium, it may be refracted at the
incident surface of the second substrate 4. .gamma. is an angle of
the fifth linearly polarized light after it has been refracted at
the surface of the second substrate 4. .delta. is an angle of the
sixth linearly polarized light after it has been refracted at the
surface of the second substrate 4. .epsilon. is an angle of the
seventh linearly polarized light after it has been refracted at the
surface of the second substrate 4.
[0079] When the driving voltage applied to the second electrode 12
is greater than zero but less than the maximum driving voltage, the
liquid crystal molecules are deflected, but its deflection degree
is less than that of the liquid crystal deflection state
corresponding to the dark display state. The liquid crystal
deflection equivalent interface is shown in FIG. 8.
[0080] Due to the effects of the deflected liquid crystal
molecules, the fifth linearly polarized light, the sixth linearly
polarized light and the seventh linearly polarized light are
deflected at the liquid crystal deflection equivalent interface.
After they are deflected, the angle at which the fifth linearly
polarized light travels is increased to .gamma..sub.1 from .gamma.,
the angle at which the sixth linearly polarized light travels is
increased to .delta..sub.1 from .delta., and the angle at which the
seventh linearly polarized light travels is increased to
.epsilon..sub.1 from .epsilon..
[0081] However, because the deflection degree is less than that of
the liquid crystal deflection state corresponding to the dark
display state, it cannot ensure all of the linearly polarized
lights can be entirely totally-reflected. In this circumstance, the
incident angle .gamma..sub.1 of the deflected fifth linearly
polarized light at the interface between the first substrate 2 and
the external environmental medium is less than the critical angle
for the total reflection at the interface. Thus, the fifth linearly
polarized light violates the total reflection condition, and thus
may exit from the interface. The incident angle .delta..sub.1 of
the deflected sixth linearly polarized light and the incident angle
.epsilon..sub.1 of the deflected seventh linearly polarized light
at the interface are both greater than the critical angle for the
total reflection at the interface. In this circumstance, the
deflected sixth linearly polarized light and the deflected seventh
linearly polarized light are totally-reflected back to the liquid
crystal layer 3 at the interface. At that time, the display device
exhibits the gray scale display state between the bright display
state and the dark display state.
[0082] It is assumed that the fifth linearly polarized light has a
light intensity of x, the sixth linearly polarized light has a
light intensity of y, and the seventh linearly polarized light has
a light intensity of z. When a certain driving voltage is applied
to the second electrode 12, due to the effects of the driving
voltage, the fifth linearly polarized light exits from the first
substrate 2 and the sixth linearly polarized light and the seventh
linearly polarized light are reflected back to the liquid crystal
layer 3. At that time, the exit linearly polarized lights have
total light intensity of x. If the driving voltage is increased
such that the fifth linearly polarized light and the sixth linearly
polarized light exit from the first substrate 2 and the seven
linearly polarized light is reflected back to the liquid crystal
layer 3, the exit linearly polarized lights have total light
intensity of x+y, that is, the display device may achieve different
levels of the gray scale display.
[0083] An embodiment of the present disclosure also provides a
display method using the display device. The display method for the
display device is applied to the display device as described in the
above embodiment.
[0084] The display method in particular includes: directing the
light emitted by the backlight source (for example with angles of
divergence) incident onto the second substrate at an oblique angle,
controlling the liquid crystal prism to regulate the deflection
angle of the light emitted by the backlight source traveling
between the first substrate and the second substrate, such that the
light emitted by the backlight source is totally-reflected at the
light exit face of the display device or exits from the light exit
face of the display device. The light exit face of the display
device is the interface between the first substrate and the
external environmental medium in contact with the display device.
As an example, the light exit face of the display device is the
surface of the first substrate away from the second substrate.
[0085] In an example, the light emitted by the backlight source
(for example with angles of divergence) is incident onto the second
substrate at an oblique angle, and the liquid crystal prism is
controlled such that the light travels along a straight line
between the first substrate and the second substrate and any of the
light is not totally-reflected at the interface between the first
substrate and the external environment and thus the light entirely
exits from the interface. In this circumstance, the display device
exhibits the bright display state.
[0086] In another example, the light emitted by the backlight
source (for example with angles of divergence) is incident onto the
second substrate at an oblique angle, and the liquid crystal prism
is controlled such that the light is deflected by the maximum
deflection angle when it travels between the first substrate and
the second substrate. In this way, the incidence angle of the
deflected light at the interface is greater than or equal to the
critical angle for the total reflection at the interface, and thus
the light is entirely totally-reflected back to the liquid crystal
layer at the interface. In this circumstance, the display device
exhibits the dark display state.
[0087] In a further example, the light emitted by the backlight
source (for example with angles of divergence) is incident onto the
second substrate at an oblique angle, and the liquid crystal prism
is controlled such that the light is deflected by a deflection
angle less than the maximum deflection angle when it travels
between the first substrate and the second substrate. In this way,
the incidence angle of one part of the deflected light at the
interface is greater than or equal to the critical angle for the
total reflection at the interface, and thus the part of the light
is entirely totally-reflected back to the liquid crystal layer at
the interface; the incidence angle of the other part of the
deflected light is less than the critical angle for the total
reflection at the interface, and thus the other part of the
deflected light exits from the interface instead of being
totally-reflected at the interface. In this circumstance, the
display device exhibits the gray scale display state between the
bright display state and the dark display state.
[0088] With the display method for the display device provided by
the present embodiments, by means of controlling the deflection
angle of the light emitted by the backlight source traveling
between the first substrate and the second substrate by the liquid
crystal prism, the magnitude of the incidence angle of the light at
the interface between the first substrate and the external
environmental medium may be regulated. Considering the total
reflection condition at the interface between the first substrate
and the external environmental medium, the display device may also
exhibit different display states without using two polarizer
sheets.
[0089] Again referring to FIG. 3, when the liquid crystal prism 9
includes the liquid crystal layer 3, the first electrode 11 and the
second electrode 12, in particular, controlling the liquid crystal
prism 9 such that the light travels along a straight line between
the first substrate 2 and the second substrate 4 may specifically
include: keeping the initial state of the liquid crystal in the
liquid crystal layer 3 instead of applying the driving voltage to
the second electrode 12 and applying the common voltage to the
first voltage 11, so as to make the light travel in the liquid
crystal layer 3 along a straight line.
[0090] Again referring to FIG. 6, when the driving voltage is not
applied to the second electrode 12, the liquid crystal in the
liquid crystal layer 3 will not be deflected. In this way, when the
linearly polarized light with angles of divergence is incident onto
the second substrate at an oblique angle, the light is kept to
travel along the straight line in the liquid crystal layer 3 and
exits from the interface between the first substrate 2 and the
external environment such that the display device is in the bright
display state.
[0091] In particular, controlling the liquid crystal prism 9 such
that the light is deflected by the maximum deflection angle when it
travels between the first substrate 2 and the second substrate 4
may include: applying the maximum driving voltage to the second
electrode 12 and applying the common voltage to the first electrode
11 to deflect the liquid crystal such that the light is deflected
by the maximum deflection angle in the liquid crystal layer.
[0092] Again referring to FIG. 7, the maximum driving voltage is
applied to the second electrode 12 such that the liquid crystal is
deflected by a relatively large deflection degree. In this way,
when the linearly polarized light with angles of divergence is
incident onto the second substrate 4 at an oblique angle, due to
the effects of the deflected liquid crystal, the linearly polarized
light is deflected in the liquid crystal layer 3 and the incidence
angle of the deflected linearly polarized light at the interface is
greater than or equal to the critical angle for the total
reflection at the interface and thus the linearly polarized light
is entirely totally-reflected back to the liquid crystal layer 3 at
the interface. In this circumstance, the display device is in the
dark display state.
[0093] In particular, controlling the liquid crystal prism 9 such
that the light is deflected by a deflection angle less than the
maximum deflection angle when it travels between the first
substrate 2 and the second substrate 4 may include: applying a
driving voltage greater than zero but less than the maximum driving
voltage to the second electrode 12 and applying the common voltage
to the first electrode 11 to deflect the liquid crystal such that
the light is deflected by the deflection angle less than the
maximum deflection angle in the liquid crystal layer 3.
[0094] Again referring to FIG. 8, the driving voltage greater than
zero but less than the maximum driving voltage is applied to the
second electrode 12 such that the liquid crystal is deflected. In
this way, when the linearly polarized light with angles of
divergence is incident onto the surface of the second substrate 4
away from the first substrate 2, due to the effects of the
deflected liquid crystal, the linearly polarized light is deflected
in the liquid crystal layer 3. However, since the applied driving
voltage is less than the maximum driving voltage, the deflection
angle of the linearly polarized light is less than the deflection
angle corresponding to the maximum driving voltage. In this way,
one part of the linearly polarized light with relatively large
incidence angle, after being deflected, has the incidence angle at
the interface greater than or equal to the critical angle and thus
is totally-reflected back to the liquid crystal layer 3 at the
interface, and the other part of the linearly polarized light with
relatively small incidence angle, after being deflected, has the
incidence angle at the interface less than the critical angle and
thus exits from the interface. In this way, one part of the
linearly polarized light exits from the first substrate 2 while the
other part of the linearly polarized light is reflected back to the
liquid crystal layer 3, such that the display device exhibits the
gray scale display state between the bright display state and the
dark display state.
[0095] In an example, if it is desired to make the display device
to exhibit the bright display state, it may apply a driving voltage
V.sub.1 (for example, V.sub.1=0V) to the second electrode 12,
correspondingly, the linearly polarized light has the deflection
angle .kappa..sub.1=0.degree..
[0096] If it is desired to make the display device to exhibit the
dark display state, it may apply a maximum driving voltage V.sub.2
(for example, V.sub.2=10V) to the second electrode 12,
correspondingly, the linearly polarized light has the maximum
deflection angle .kappa..sub.2=5.degree.. If it is desired to make
the display device to exhibit the gray scale display state between
the bright display state and the dark display state and ensure one
part of the linearly polarized light to exit from the first
substrate 2 and the other part of the linearly polarized light to
be reflected back to the liquid crystal layer 3, the driving
voltage V.sub.3 applied to the second electrode 12 needs to
satisfy: 0V<V.sub.3<V.sub.2, correspondingly, the linearly
polarized light has the deflection angle
.dwnarw..sub.3<5.degree..
[0097] As an example, the linearly polarized light has an incidence
angle in a range from 55 degrees to 60 degrees when the light is
incident onto the surface of the second substrate 4 away from the
first substrate 2.
[0098] In addition, when the display device further includes the
polarizer sheet arranged between the second substrate and the
backlight source, before the light emitted by the backlight source
enters the second substrate, the method further includes:
converting the light into the linearly polarized light.
[0099] Only some exemplified embodiments of the present disclosure
are explained in the above description. However, the scope of the
present disclosure is not limited to those. Any variants or
alternations that the skilled person in the art can easily envisage
within the technical range of the present disclosure should fall
within the scope of the present disclosure. Therefore, the scope of
the present disclosure should be defined by the scope of the
appended claims.
* * * * *