CN103941477B - Display device - Google Patents

Abstract

The invention discloses a display device which comprises a display panel, a first polaroid and a second polaroid. The display panel comprises a pixel array substrate, an opposite substrate and a display medium. The pixel array substrate comprises a plurality of pixel units. Each pixel unit comprises a first electrode and a second electrode. The first electrodes and the second electrodes are alternately arranged, and a transverse electric field is arranged between the first electrodes and the second electrodes. The opposite substrate is opposite to the pixel array substrate. The display medium is arranged between the pixel array substrate and the opposite substrate. The first polarizer is arranged on the pixel array substrate. The second polarizer is arranged on the opposite substrate, wherein an included angle is formed between the optical axis of the first polarizer and the optical axis of the second polarizer, the included angle is 90 degrees +/-theta, and theta is 1-9 degrees.

Description

display device

technical field

The present invention relates to a display device, and in particular to a display device with non-orthogonal polarizers.

Background technique

In order to meet the needs of consumers, display device related manufacturers have invested in the development of blue phase liquid crystal display devices with fast response characteristics. Taking the blue phase liquid crystal material as an example, it generally requires a transverse electric field to operate so that it has the function of a light valve. At present, some people have used the electrode design of an in-plane switching IPS (In-Plane Switching) display module to drive blue phase liquid crystal molecules in a blue phase liquid crystal display device.

Generally speaking, if the display device can have a good dark state or bright state effect, the display contrast can be improved, so that the display device can have better display quality. However, if there is light leakage in the display device, it will lead to poor dark state effect, and further affect the display contrast. Therefore, how to reduce the light leakage phenomenon of the display device to improve the display contrast has become one of the topics that those skilled in the art want to study.

Contents of the invention

The invention provides a display device, which reduces the light leakage phenomenon by setting an optical film whose optical axis is shifted by an angle, so as to provide good display contrast.

The invention provides a display device. The display device includes a display panel, a first polarizer and a second polarizer. The display panel includes a pixel array substrate, an opposite substrate and a display medium. The pixel array substrate includes a plurality of pixel units. Each pixel unit includes a first electrode and a second electrode. The first electrodes and the second electrodes are arranged alternately, and there is a transverse electric field between the first electrodes and the second electrodes. The opposite substrate is arranged opposite to the pixel array substrate. The display medium is arranged between the pixel array substrate and the opposite substrate. The first polarizer is arranged on the pixel array substrate. The second polarizer is disposed on the opposite substrate, wherein there is an angle between the optical axis of the first polarizer and the optical axis of the second polarizer, the included angle is 90°±θ1, and θ1 is 1°˜9°.

The invention provides a display device. The display device includes a display panel, a first polarizer, a second polarizer, a first positive A-plate compensation film and a second positive A-plate compensation film. The display panel includes a pixel array substrate, an opposite substrate and a display medium. The pixel array substrate includes a plurality of pixel units. Each pixel unit includes a first electrode and a second electrode. The first electrodes and the second electrodes are arranged alternately, and there is a transverse electric field between the first electrodes and the second electrodes. The opposite substrate is arranged opposite to the pixel array substrate. The display medium is arranged between the pixel array substrate and the opposite substrate. The first polarizer is arranged on the pixel array substrate. The second polarizer is disposed on the opposite substrate, wherein there is a first included angle between the first optical axis of the first polarizer and the second optical axis of the second polarizer, and the first included angle is 90°. The first positive A-plate compensation film is disposed on the pixel array substrate and between the display panel and the first polarizer, wherein the first optical axis of the first polarizer and the fifth optical axis of the first positive A-plate compensation film has a second included angle. The second positive A-plate compensation film is disposed on the opposite substrate and between the display panel and the second polarizer, wherein the first optical axis of the first polarizer and the sixth optical axis of the second positive A-plate compensation film Has a third included angle. The second included angle is 0°-θ1, θ1 is 1°-9°, and the third included angle is 0°+θ2, θ2 is 1°-9°, or the second included angle is 0°+θ1, θ1 is 1 ° to 9°, and the third included angle is 0°-θ2, and θ2 is 1° to 9°.

The invention provides a display device. The display device includes a display panel, a first polarizer, a second polarizer and a compensation film. The display panel includes a pixel array substrate, an opposite substrate and a display medium. The pixel array substrate includes a plurality of pixel units. Each pixel unit includes a first electrode and a second electrode. The first electrodes and the second electrodes are arranged alternately, and there is a transverse electric field between the first electrodes and the second electrodes. The opposite substrate is arranged opposite to the pixel array substrate. The display medium is arranged between the pixel array substrate and the opposite substrate. The first polarizer is arranged on the pixel array substrate. The second polarizer is disposed on the opposite substrate, wherein there is an included angle between the first optical axis of the first polarizer and the second optical axis of the second polarizer, and the included angle is 90°. The compensation film is disposed on the pixel array substrate and between the display panel and the first polarizer, wherein the compensation film is composed of a plurality of twisted nematic liquid crystal molecules. Among the twisted nematic liquid crystal molecules, there is a distance between the seventh optical axis of the first twisted nematic liquid crystal molecule closest to the first polarizer and the eighth optical axis of the second twisted nematic liquid crystal molecule closest to the display panel. Included angle, the included angle is 0°±θ, and θ is 1°～9°.

The invention provides a display device. The display device includes a display panel, a first polarizer and a second polarizer. The display panel includes a pixel array substrate, an opposite substrate and a display medium. The pixel array substrate includes a plurality of pixel units. The opposite substrate is arranged opposite to the pixel array substrate. The display medium is arranged between the pixel array substrate and the opposite substrate. The first polarizer is arranged on the pixel array substrate. The second polarizer is arranged on the opposite substrate, and there is an included angle between the optical axis of the first polarizer and the optical axis of the second polarizer, wherein, when the display medium is a right-handed material, the included angle is greater than 90°, When the display medium is a left-handed material, the included angle is less than 90°.

Based on the above, in the display device proposed by the embodiment of the present invention, by setting an optical film whose optical axis is shifted by an angle, wherein the angle is 1° to 9°, the light leakage phenomenon generated by the display device can be effectively reduced to increase The display contrast of the display device is improved and the display quality is improved.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic perspective view of a display device according to an embodiment of the present invention;

FIG. 2A is a schematic partial cross-sectional view of the display device of FIG. 1;

2B is a schematic partial cross-sectional view of a display device according to another embodiment of the present invention;

3 is a schematic diagram of a pixel unit circuit of the display device shown in FIG. 1;

4 is a diagram showing the relationship between the polarization rotation angle and the gap of the display device according to an embodiment of the present invention;

FIG. 5 is a graph showing the relationship between optical rotatory power and Bragg diffraction wavelength of a display device according to an embodiment of the present invention;

6 is a relationship diagram between light leakage ratios and azimuth angles of multiple display devices;

7 is a graph showing the relationship between the light leakage ratio and the polarization rotation angle of a display device according to an embodiment of the present invention;

8 is a graph showing the relationship between the light leakage ratio and the polarization rotation angle of a display device according to another embodiment of the present invention;

9 is a schematic perspective view of a display device according to an embodiment of the present invention;

Fig. 10 is a schematic diagram of the contrast of the existing display device at various viewing angles, wherein the optical axes of the two polarizers arranged in the existing display device are orthogonal;

FIG. 11 is a schematic diagram of the contrast of the display device 20 in FIG. 9 at various viewing angles;

FIG. 12A is a schematic perspective view of a display device according to an embodiment of the present invention;

FIG. 12B is a schematic perspective view of a display device according to another embodiment of the present invention;

FIG. 13 is a schematic diagram of the contrast of the display device 30 in FIG. 12A under various viewing angles;

14 is a schematic perspective view of a display device according to an embodiment of the present invention;

FIG. 15 is an enlarged partial cross-sectional view of the display device of FIG. 14;

FIG. 16 is a schematic diagram of the contrast of the display device 40 in FIG. 14 under various viewing angles.

Among them, reference signs:

10, 20, 30, 30’, 40: display device

100: display panel

110: Pixel array substrate

120: opposite substrate

130: display media

112: First substrate

114: first electrode

116: second electrode

120: opposite substrate

122: Second substrate

124: Color filter layer

124a: the first filter pattern

124b: second filter pattern

124c: the third filter pattern

200: first polarizer

210: first optical axis

300, 600: second polarizer

310, 610: second optical axis

400: light source module

500, 800: biaxial compensation film

510: Third Optical Axis

700A, 700A': the first positive A-plate compensation film

700B, 700B': second positive A-plate compensation film

710A, 710A': fifth optical axis

710B, 710B': the sixth optical axis

900: compensation film

900A, 900B: twisted nematic liquid crystal molecules

903A: Seventh Optical Axis

903B: Eighth optical axis

a, a', b, b', c, x, y, z: included angle

CL: common electrode line

DL: data line

D1: first direction

D2: Second direction

D3: Third direction

D4: Fourth direction

D5, D5': the fifth direction

D6, D6': the sixth direction

D7: Seventh direction

D8: Eighth direction

E1, E2: Transverse electric field

P: pixel unit

SL: scan line

T: active component

Vp: first voltage

Vcom: second voltage

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

FIG. 1 is a schematic perspective view of a display device according to an embodiment of the present invention. FIG. 2A is a schematic partial cross-sectional view of the display device in FIG. 1 . Referring to FIG. 1 and FIG. 2 , the display device 10 of this embodiment includes a display panel 100 , a first polarizer 200 , a second polarizer 300 and a light source module 400 . The light source module 400 is disposed on one side of the display device 100 , and the light source module 400 provides incident light to the display panel 100 . The display panel 100 includes a pixel array substrate 110 , an opposite substrate 120 and a display medium 130 .

The pixel array substrate 110 includes a plurality of pixel units P. The pixel units P are arranged in an array on the first substrate 112 . Each pixel unit P includes a first electrode 114 and a second electrode 116 . The first electrodes 114 and the second electrodes 116 are alternately disposed on the first substrate 112 . When a voltage is applied to the first electrode 114 and the second electrode 116 , a transverse electric field E1 is formed between the first electrode 114 and the second electrode 116 , wherein the transverse electric field E1 is substantially parallel to the surface of the first substrate 112 . In this embodiment, the first electrode 114 and the second electrode 116 belong to the same film layer and are disposed on the same plane, so that the display device 10 of this embodiment is an In-Plane Switch (IPS) design.

In another embodiment, as shown in FIG. 2B , the first electrode 114 and the second electrode 116 may also belong to different film layers and be arranged on different planes. The insulating layer 118 electrically insulates the first electrode 114 from the second electrode 116 . In the embodiment of FIG. 2B , when a voltage is applied to the first electrode 114 and the second electrode 116 , a lateral electric field E2 can be formed on the first electrode 114 and the second electrode 116 . The display device 10a shown in FIG. 2B is a Fringe Field Switch (FFS) design. However, the present invention is not limited thereto. As long as the display device is designed with electrodes having a transverse electric field, it falls within the protection scope of the present invention.

In the foregoing embodiments, the first electrode 114 and the second electrode 116 are, for example, transparent electrodes, and their materials include metal oxides, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, InGeZnO, or other suitable metal oxides, or a stacked layer of at least two of the above.

FIG. 3 is a schematic diagram of a pixel unit circuit of the display device shown in FIG. 1 . Referring to FIG. 1 and FIG. 3 , the first electrode 114 of this embodiment is electrically connected to the active device T, and the first electrode 114 has a first voltage Vp, for example. The second electrode 116 is electrically connected to the common electrode line CL, and the second electrode 116 has a second voltage Vcom, for example. One end of the active element T is connected to the scan line SL, and the other end is connected to the data line DL. Here, the active element T can be used as a switch element whether to write the voltage information into the first electrode 114 , and the type of the active element T can be a bottom gate thin film transistor or a top gate thin film transistor. When the active element T is turned on to write voltage information into the first electrode 114, a voltage is applied to the first electrode 114, and its voltage value is different from the voltage value of the common electrode line CL, so that the distance between the first electrode 114 and the second electrode 116 There is a voltage difference between them. At this time, a transverse electric field E1 is generated between the first electrode 114 and the second electrode 116 to drive the display medium 130 .

Referring to FIG. 1 and FIG. 2A again, the opposite substrate 120 is disposed on the opposite side of the pixel array substrate 110 . The opposite substrate 120 includes a second substrate 122 and a color filter layer 124 disposed on the second substrate 122 . The color filter layer 124 includes a first filter pattern 124a, a second filter pattern 124b and a third filter pattern 124c. In this embodiment, the first filter pattern 124a, the second filter pattern 124b and the third filter pattern 124c are red filter patterns, green filter patterns and blue filter patterns respectively. Of course, the present invention is not limited thereto. Those skilled in the art can change the configuration of the color filter patterns according to design requirements. In addition, this embodiment is described by taking the opposite substrate 120 as a color filter substrate as an example. However, the present invention is not limited thereto. In other embodiments, the color filter layer 124 can also be disposed on the pixel array substrate 110 to form a color filter layer 124 integrated on a thin film transistor array (Color filter on Array, COA) substrate, or a thin film transistor array integrated on a color filter on array substrate. The filter layer 124 is an Array on Color filter (AOC) substrate.

The display medium 130 is located between the pixel array substrate 110 and the opposite substrate 120 . In this embodiment, the display medium 130 is optically isotropic when the transverse electric field E1 is not applied, and is optically anisotropic after being driven by the transverse electric field E. According to this embodiment, the above-mentioned display medium 130 includes blue phase liquid crystals, such as polymer-stabilized blue phase liquid crystals (polymer-stabilized blue phase liquid crystals) or polymer-stabilized isotropic phase liquid crystals (polymer-stabilized isotropic phase liquid crystals) and so on. In this embodiment, the display medium 130 is driven by the formation of the transverse electric field E1, so that the display medium 130 switches between optical isotropy and optical anisotropy, so that the display medium 130 functions as a light valve.

The first polarizer 200 is disposed on the pixel array substrate 110 , and the second polarizer 300 is disposed on the opposite substrate 120 . In FIG. 1 , the first polarizer 200 and the second polarizer 300 are disposed on opposite outer sides of the display panel 100 as an example for illustration, however, the present invention is not limited thereto. In other embodiments, the first polarizer 200 and the entire side polarizer 300 can also be integrated inside the display panel 100 .

The first polarizer 200 has a first optical axis 210, and the second polarizer 300 has a second optical axis 310, wherein the first optical axis 210 is parallel to the first direction D1, and the second optical axis 310 is parallel to the second direction D2. As shown in FIG. 1 , there is an angle x between the first optical axis 210 and the second optical axis 310 . In this embodiment, the included angle x is 90°±θ1, and θ1 is 1°˜9°. In other embodiments, θ1 is 1.5°˜6.5°, and θ1 is preferably 1.5°˜3.5°. Specifically, when the angle x between the first optical axis 210 of the first polarizer 200 and the second optical axis 310 of the second polarizer 300 is 90°±θ1, and θ1 is 1°˜9°, The light leakage phenomenon of the display device 10 can be effectively further reduced, thereby increasing the display contrast of the display device 10 .

Generally speaking, in a display device that drives the display medium with a transverse electric field, two polarizers are usually arranged on opposite sides of the display panel, and the optical axes of the two polarizers are usually orthogonal (that is, the distance between the optical axes of the two polarizers). The angle between them is 90°) to play a light-blocking effect and reduce the phenomenon of light leakage. However, the inventor further found that when the two polarizers are arranged to be orthogonal, there will still be a certain degree of light leakage. Based on the above, the present invention can reduce the light leakage phenomenon of the display device 10 and improve the display quality of the display device 10 by relatively rotating the first polarizer 200 and the second polarizer 300 by a certain angle (including left-handed or right-handed).

Specifically, the display medium 130 of this embodiment is, for example, a blue phase liquid crystal. Applying a transverse electric field E1 to the blue-phase liquid crystal can make it optically anisotropic. At this time, the blue-phase liquid crystal has the characteristic of polarization rotation. When the incident light passes through the blue-phase liquid crystal, it will generate outgoing light, and The direction of the outgoing light will be affected by the polarization rotation characteristic and will deviate from the predetermined direction of the outgoing light by a certain angle. This angle is called the polarization rotation angle (ie θ). Specifically, the blue-phase liquid crystal molecules are arranged in a double twist cylinder, and such an arrangement causes the above-mentioned polarization phenomenon. Therefore, due to the polarization rotation characteristics, the blue-phase liquid crystal cannot adjust the direction of the outgoing light to a predetermined direction, so there is a certain degree of deviation angle, and light leakage occurs. Accordingly, the present invention adjusts the direction of the optical axis of the polarizer so that the angle between the optical axes of the polarizer is not 90 degrees (that is, 90°±θ1), and then increases or decreases the light output of the polarizer based on 90 degrees. The offset angle of the axis (that is, θ1 ) increases the light-blocking effect of the polarizer, thereby improving the display contrast of the display device 10 . More specifically, the present invention increases the light-blocking effect of the polarizer by making the offset angle θ1 of the optical axis of the polarizer the same as the polarization rotation angle θ, thereby improving the display contrast of the display device 10 .

Generally speaking, the materials of the display medium can be divided into left-handed materials and right-handed materials. Here, when the polarizer rotates in the positive direction, the light leakage ratio decreases, and when it rotates in the negative direction, the light leakage ratio increases, which means that the display medium is a right-handed material. Conversely, when the polarizer rotates in the positive direction, the light leakage ratio increases, and when it rotates in the negative direction, the light leakage ratio decreases, which means that the display medium is a left-handed material. In other words, when the display medium is a right-handed material, the angle between the two polarizers is greater than 90°; and when the display medium is a left-handed material, the angle between the two polarizers is less than 90°.

In one embodiment, when the display medium is a right-handed material, the angle between the two polarizers is 90°+θ1, and θ1 is 1°-9°, wherein, in a preferred embodiment, θ is 1.5° ~6.5°. In addition, in another embodiment, when the display medium is a left-handed material, the angle between the two polarizers is 90°-θ1, and θ1 is 1°-9°, wherein, in a preferred embodiment, θ1 ranges from 1.5° to 6.5°.

Based on the above, it can be seen that in the present invention, the display contrast of the display device 10 is improved by making the offset angle θ1 of the optical axis of the polarizer equal to the polarization rotation angle θ. Hereinafter, the polarization rotation angle θ will be discussed in detail through multiple embodiments.

The present invention further finds that when designing the angle between the first polarizer 200 and the second polarizer 300, the polarization rotation angle θ will comply with the following relationship:

$\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; \&Proportional;</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; no</span>}}_{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}$

d is the gap between the pixel array substrate and the opposite substrate, Δn _{(λ, T)} is the refraction rate of the display medium, λ is the wavelength of the incident light source, and λ _B is the Bragg diffraction wavelength of the material of the display medium.

4 is a graph showing the relationship between the polarization rotation angle θ and the gap d of a display device according to an embodiment of the present invention, where the display device is irradiated with incident light rays of different wavelengths (633nm, 514nm, 457nm). It can be seen from FIG. 4 that the polarization rotation angle θ is roughly proportional to the gap d.

Fig. 5 is the relationship between the optical rotational power (Optical rotational power) and the Bragg diffraction wavelength of the display device of the present invention, wherein the optical rotational power is the ratio of the polarization rotation angle θ to the gap d, Δn _{(λ, T)} is about 0.18, empirical constant is 3.05°/μm, and the curves in Fig. 5 respectively indicate that the wavelength λ of the incident light source is 457nm (Δ), 514nm (●) and 633nm (○) from left to right. It can be seen from the curve in FIG. 5 that the optical rotation power and the Bragg diffraction wavelength of the display device according to the embodiment of the present invention comply with the following relationship:

Fig. 6 is a graph showing the relationship between the light leakage ratio and the azimuthal angel of several display devices, wherein these display devices are all designed for coplanar conversion, the wavelength λ of the incident light is 514nm, and the refractive index Δn _{(λ, T)} is about 0.18, the gap d is 7.4 μm, and the Bragg diffraction wavelength λ _B is about 410 nm. After calculation through experimental simulation, it can be obtained that the polarization rotation angle θ should be designed to be 1.6°. At this time, please refer to Fig. 6. Curve a represents an embodiment in which the polarization rotation angle θ is 1° to the left, curve b represents a comparative example in which the polarization rotation angle θ is 0°, and curve c represents the embodiment in which the polarization rotation angle θ is 1° to the right. In an embodiment, curve d represents an embodiment in which the polarization rotation angle θ is 3° to the right, and curve e represents an embodiment in which the polarization rotation angle θ is 2° to the right.

In the embodiment of FIG. 6 , the azimuth angle is an angle for rotating the display device. For example, after fixing the incident light direction, the display device is rotated to obtain different azimuth angles. Due to different azimuth angles, the included angle between the electrodes and the light component of the incident light source on the display device will change accordingly, which may also affect the light valve action of the display medium and cause light leakage. It can be seen from FIG. 6 that the light leakage ratios are similar at various azimuth angles. In other words, at different azimuth angles, the light leakage phenomenon can be reduced, and the contrast effect can also be improved.

7 is a graph showing the relationship between the light leakage ratio and the polarization rotation angle of a display device according to an embodiment of the present invention, wherein the display device has a refractive index Δn _{(λ, T)} of about 0.17-0.19, a gap d of 7.4 μm, and a Bragg diffraction wavelength λ _B is about 400 nm to 420 nm. Curves 1, 2, and 3 respectively represent the results of using red light, green light, and blue light as incident light, and the dotted line in Fig. 7 represents the result of white light generated by integrating red light, green light, and blue light. It can be seen from Figure 7 that the polarization rotation angle with the lowest light leakage ratio of red light is about 0.5°, the polarization rotation angle with the lowest light leakage ratio of green light is about 2.5°, and the polarization rotation angle with the lowest light leakage ratio of blue light is about 5.5°. Overall, when the polarization rotation angle θ is 1.5°˜3.5°, the light leakage phenomenon of the display device can be effectively reduced.

In addition, when the polarization rotation angle θ is 2°, the light leakage ratio is about 0.08%, and the contrast ratio is 1000. Under the same test conditions, the light leakage ratio of the existing display device with the polarizer having a polarization rotation angle θ of 0° (that is, an orthogonal design) is 0.25%, and the contrast ratio is 300. It can be seen that, compared with the contrast ratio of the conventional display device, the contrast ratio of the display device in FIG. 7 is improved by more than three times and thus has good display quality.

Fig. 8 is a graph showing the relationship between the light leakage ratio and the polarization rotation angle of a display device according to another embodiment of the present invention, wherein the display device has a refractive index Δn of about 0.18-0.2, a gap d of 10 μm, and a Bragg diffraction wavelength λ _B of about 370 nm ~390nm. It can be seen from FIG. 8 that when the polarization rotation angle θ is 3°˜7°, the light leakage phenomenon of the display device can be effectively reduced. It can be seen from Figure 7 that the overall light leakage phenomenon of white light (dotted line) has the same trend as that of green light, and compared with red and blue light, green light has a greater impact on contrast, while Figure 8 shows the combined red and green light And the resulting white light after the blue light.

second embodiment

FIG. 9 is a schematic perspective view of a display device according to an embodiment of the present invention. Please refer to FIG. 9 and FIG. 1 at the same time. The display device 20 in FIG. 9 is similar to the display device 10 in FIG. 1 described above, so the same components as in FIG. 1 are denoted by the same symbols and will not be repeated here. The only difference between the display device 20 in FIG. 9 and the display device 10 in FIG. 1 is that the display device 20 in FIG. 9 further includes a biaxial compensation film 500 disposed between the display panel 100 and the second polarizer 300 . In addition, the detailed structure of each component of the display panel 100 is not shown in detail in FIG. 9 .

Generally speaking, biaxial compensation film is mainly used to increase viewing angle. In this embodiment, the biaxial compensation film 500 has a third optical axis 510, wherein the third optical axis 510 is parallel to the third direction D3. As shown in FIG. 9, the first optical axis 210 of the first polarizer 200 is parallel to the first direction D1, and the second optical axis 310 of the second polarizer 300 is parallel to the second direction D2, so that the first optical axis 210 and the biaxial compensation There is an angle y between the third optical axes 510 of the film 500 . In this embodiment, the included angle y is 0°±θ2, and θ2 is 1°˜9°. In other embodiments, θ2 is 1.5°˜6.5°, and θ2 is preferably 1.5°˜3.5°. In one embodiment, when the display medium is a right-handed material, the included angle y is 90°+θ2. In another embodiment, when the display medium is a left-handed material, the included angle y is 90°-θ2.

Specifically, the angle x between the first optical axis 210 of the first polarizer 200 and the second optical axis 310 of the second polarizer 300 is 90°±θ1, and θ1 is 1°-9° Next, by further disposing the biaxial compensation film 500 , the light leakage phenomenon of the display device 20 can be further effectively reduced, thereby increasing the display contrast of the display device 20 .

Below, Table 1 illustrates the effects of θ1 of included angle x and θ2 of included angle y on contrast and viewing angle at the same Bragg diffraction wavelength, where λ _B is the Bragg diffraction wavelength of the material of the display medium.

Table 1

In detail, it can be seen from Table 1 that when both the θ1 of the included angle x and the θ2 of the included angle y fall within the range defined by the present invention (that is, 1°-9°), the display device 20 has a good display contrast. and viewing angles. In addition, further speaking, the θ1 of the included angle x and the θ2 of the included angle y are preferably the same, so that the display device 20 has good display contrast and viewing angle.

In addition, in this embodiment, the thickness of the biaxial compensation film 500 is 27.5 μm, and the refractive indices of the biaxial compensation film 500 along the X-axis, Y-axis and Z-axis are respectively Nx, Ny and Nz, wherein at all wavelengths Here, Nx is 1.51, Ny is 1.5, and Nz is 1.505.

FIG. 10 is a schematic diagram of the contrast of a conventional display device at various viewing angles, wherein the optical axes of the two polarizers arranged in the conventional display device are orthogonal. FIG. 11 is a schematic diagram of the contrast of the display device 20 in FIG. 9 under various viewing angles. In the contrast diagrams of FIG. 10 and FIG. 11 , the numbers on the circles represent the viewing angles, and the numbers on the closed curves in the circles represent the contrast. It can be seen from FIG. 10 and FIG. 11 that the center contrast ratio measured by using the display device 20 is 6000, while the center contrast ratio measured by using the existing display device is 1000. Therefore, the display device 20 can display better contrast ratio. In other words, in the display device 20 , by disposing the first polarizer 200 , the second polarizer 300 and the biaxial compensation film 500 , the display contrast of the display device 20 under different viewing angles can be improved.

third embodiment

FIG. 12A is a schematic perspective view of a display device according to an embodiment of the present invention. Please refer to FIG. 12A and FIG. 1 at the same time. The display device 30 in FIG. 12A is similar to the display device 10 in FIG. 1 described above, so the same components as in FIG. 1 are denoted by the same symbols and will not be repeated here. In addition, the detailed structure of each component of the display panel 100 is not shown in FIG. 12A in detail.

In detail, the difference between the display device 30 in FIG. 12A and the display device 10 in FIG. 1 is that: the second polarizer 600 in FIG. 12A has a second optical axis 610, wherein the second optical axis 610 is parallel to the fourth direction D4, and The included angle z between the second optical axis 610 and the first optical axis 210 is 90°, and the display device 30 in FIG. 12A further includes a first positive A-plate compensation film 700A, a second positive A-plate compensation film 700B, and Biaxial compensation film 800 . The first positive A-plate compensation film 700A is disposed between the display panel 100 and the first polarizer 200 , and the second positive A-plate compensation film 700B is disposed between the display panel 100 and the second polarizer 600 . The biaxial compensation film 800 is disposed on the second positive A-plate compensation film 700B and between the display panel 100 and the second polarizer 600 .

In this embodiment, the biaxial compensation film 800 is used to polarize the light emitted from the display panel 100, and the biaxial compensation film 800 may be any biaxial compensation film known to those skilled in the art, for example The biaxial compensation film 500 in the above embodiment. In addition, in FIG. 12A , the biaxial compensation film 800 is disposed between the display panel 100 and the second polarizer 600 as an example for illustration, however, the present invention is not limited thereto. In an embodiment, the biaxial compensation film 800 may also be disposed between the display panel 100 and the first polarizer 200 . In another embodiment, the biaxial compensation film 800 can also be disposed between the display panel 100 and the second polarizer 600 and between the display panel 100 and the first polarizer 200 at the same time. In yet another embodiment, the display device 30 may not be provided with the biaxial compensation film 800 .

The first positive A-plate compensation film 700A and the second positive A-plate compensation film 700B are used to compensate the polarization rotation characteristic of the blue phase liquid crystal. In detail, the first positive A-plate compensation film 700A has a fifth optical axis 710A, and the second positive A-plate compensation film 700B has a sixth optical axis 710B, wherein the fifth optical axis 710A is parallel to the fifth direction D5, The sixth optical axis 710B is parallel to the sixth direction D6. As shown in FIG. 12A , there is an included angle a between the fifth optical axis 710A and the first optical axis 210 , and an included angle b between the sixth optical axis 710B and the first optical axis 210 . In this embodiment, the included angle a is 0°-θ3, and θ3 is 1°-9°, and the included angle b is 0°+θ4, and θ4 is 1°-9°, and θ4 is the same as θ3. In other embodiments, θ3 and θ4 are 1.5°˜6.5°, and θ3 and θ4 are preferably 1.5°˜3.5°.

In addition, in this embodiment, both the first positive A-plate compensation film 700A and the second positive A-plate compensation film 700B are optically positive uniaxial compensation films, that is, the first positive A-plate compensation film 700A and the second positive A-plate compensation film 700B are optically positive uniaxial compensation films. The Ne of the second positive A-plate compensation film 700B is greater than No and the birefringence Δn is greater than 0, wherein No is defined as the refractive index of liquid crystal molecules to ordinary light (ordinary ray), and Ne is defined as the liquid crystal molecule to extraordinary light (extraordinary ray). The refractive index and the birefringence Δn are defined as Ne-No and are a function of wavelength. Furthermore, in this embodiment, at wavelengths of 450 nm, 550 nm and 650 nm, the birefringence Δn is optimized for the optical rotation power (ORP) of the blue phase liquid crystal.

As mentioned above, in a display device in which the display medium is a blue-phase liquid crystal, since the blue-phase liquid crystal molecules are arranged in a double-twisted cylindrical shape, even if the optical axes of the two polarizers are set to be orthogonal (that is, between the optical axes of the two polarizers The angle between them is 90°), there will still be a certain degree of light leakage. In view of this, in the first embodiment, by setting the first polarizer 200 and the second polarizer 300 whose optical axis angle x is 90°±θ1, and θ1 is 1°-9°, the display device 10 can be reduced. The phenomenon of light leakage, and the effect of improving the display contrast of the display device 10 .

Therefore, based on the same spirit, in the third embodiment, in the case where the first polarizer 200 and the second polarizer 600 are set to be perpendicular, by setting the first polarizer 200 to have a clip with the first optical axis 210 The first positive A-plate compensation film 700A with an angle a of 0°-θ3, and θ3 of 1°-9°, and the angle b with the first optical axis 210 of the first polarizer 200 is 0°+θ4, and The second positive A-plate compensation film 700B whose θ4 is 1°˜9° can also further reduce the light leakage phenomenon of the display device 30 , and further increase the display contrast of the display device 30 .

From another point of view, as mentioned above, the materials of the display medium can be generally divided into left-handed materials and right-handed materials, and at this time, the polarization rotation angle of the display device will be left-handed or right-handed according to the display medium used. Materials vary. In detail, in this embodiment, the display medium in the display device 30 shown in FIG. 12A is a right-handed material. That is to say, when the display medium is a right-handed material, the included angle a of the display device 30 is set to be 0°-θ3, and θ3 is set to be 1°-9°, while the included angle b is set to be 0°+θ4, and θ4 1°˜9° and θ4 being the same as θ3 can effectively reduce the light leakage phenomenon of the display device 30 , and further increase the display contrast of the display device 30 .

In addition, as can be seen above, the offset angles (that is, θ3 and θ4 ) will vary with the Bragg diffraction wavelength λ _B of the material of the display medium. For example, when the Bragg diffraction wavelength λ _B of the blue-phase liquid crystal is 380nm, the optical rotation is right-handed, the gap d is 7.4 μm, and the thickness of the A-plate compensation film is 10 μm, the included angle a of the display device 30 is -2 ° (meaning that θ3 is 2°), the included angle b is +2° (meaning that θ4 is 2°), and at wavelengths of 450nm, 550nm and 650nm, the first positive type A plate compensation film 700A and the second positive type A plate The birefringence Δn of the plate compensation film 700B is 0.006, 0.005 and 0.003, respectively. As another example, when the Bragg diffraction wavelength λ _B of the blue-phase liquid crystal is 410nm, the optical rotation is right-handed, the gap d is 7.4 μm, and the thickness of the A-plate compensation film is 10 μm, the included angle a of the display device 30 is - 1.5° (meaning θ3 is 1.5°), the included angle b is +1.5° (meaning θ4 is 1.5°), and at wavelengths of 450nm, 550nm and 650nm, the first positive A-plate compensation film 700A and the second The birefringence Δn of the positive A-plate compensation film 700B is 0.012, 0.007 and 0.004, respectively. However, the present invention is not limited thereto. In other embodiments, the display device may also use a display medium of a left-handed material, as shown in FIG. 12B .

FIG. 12B is a schematic perspective view of a display device according to another embodiment of the present invention. Please refer to FIG. 12B and FIG. 12A at the same time. The display device 30' in FIG. 12B is similar to the display device 30 in FIG.

In detail, the difference between the display device 30' of FIG. 12B and the display device 30 of FIG. 12A is that: the first positive A-plate compensation film 700A' of the display device 30' of FIG. 12B has a fifth optical axis 710A', and the second The two positive A-plate compensation films 700B' have a sixth optical axis 710B', wherein the fifth optical axis 710A' is parallel to the fifth direction D5', and the sixth optical axis 710B' is parallel to the sixth direction D6'. As shown in FIG. 12B , there is an included angle a' between the fifth optical axis 710A' and the first optical axis 210 , and an included angle b' between the sixth optical axis 710B' and the first optical axis 210 . In this embodiment, the included angle a' can be 0°+θ3, and θ3 is 1°-9°, while the included angle b can be 0°-θ4, and θ4 is 1°-9°, and θ4 is the same as θ3 , wherein θ3 and θ4 are preferably 1.5° to 6.5°, and θ3 and θ4 are more preferably 1.5° to 3.5°. For example, when the Bragg diffraction wavelength λ _B of the blue-phase liquid crystal is 380nm, the optical rotation is left-handed, the gap d is 7.4 μm, and the thickness of the A-plate compensation film is 10 μm, the included angle a' of the display device 30' is +2° (meaning θ3 is 2°), the included angle b' is -2° (meaning θ4 is 2°), and at wavelengths of 450nm, 550nm and 650nm, the first positive A-plate compensation film 700A' and the second positive The birefringence Δn of the type A plate compensation film 700B′ is 0.006, 0.005 and 0.003, respectively.

Based on the above, when the display medium is a left-handed material, the included angle a' through the display device 30' is set to 0°+θ3, and θ3 is 1°-9°, and the included angle b' is set to 0°-θ4 , and θ4 is 1°˜9° and θ4 is the same as θ3, which can effectively reduce the light leakage phenomenon of the display device 30 ′, and further increase the display contrast of the display device 30 ′.

FIG. 13 is a schematic diagram of the contrast of the display device 30 in FIG. 12A under various viewing angles. Please refer to FIG. 10 and FIG. 13 at the same time. The center contrast ratio measured by using the display device 30 is 12000, while the center contrast ratio measured by using the existing display device is 1000. In comparison, the display device 30 can display better contrast. In other words, in the display device 30 , by disposing the first positive A-plate compensation film 700A and the second positive A-plate compensation film 700B, the display contrast of the display device 30 under different viewing angles can be improved.

Fourth embodiment

FIG. 14 is a schematic perspective view of a display device according to an embodiment of the present invention. FIG. 15 is an enlarged partial cross-sectional view of the display device in FIG. 14 . Please refer to FIG. 14, FIG. 15 and FIG. 13 at the same time. The display device 40 in FIG. 14 is similar to the display device 30 in FIG. In addition, the detailed structure of each component of the display device 40 is not shown in detail in FIG. 14 .

In detail, the difference between the display device 40 in FIG. 14 and the display device 30 in FIG. 13 is that the display device 40 in FIG. 14 is not provided with the first positive A-plate compensation film 700A and the second positive A-plate compensation film 700B, but The display device 40 in FIG. 14 includes a compensation film 900 disposed between the display panel 100 and the first polarizer 200 , wherein the compensation film 900 is composed of a plurality of twisted nematic liquid crystal molecules.

Specifically, among the twisted nematic liquid crystal molecules, the twisted nematic liquid crystal molecule 900A closest to the first polarizer 200 has a seventh optical axis 903A, and the twisted nematic liquid crystal molecule 900B closest to the display panel 100 has a seventh optical axis 903A. The eighth optical axis 903B, wherein the seventh optical axis 903A is parallel to the seventh direction D7, and the eighth optical axis 903B is parallel to the eighth direction D8. As shown in FIG. 15 , there is an included angle c between the third optical axis 903A and the fourth optical axis 903B. In this embodiment, the included angle c is 0°±θ5, and θ5 is 1°˜9°. In other embodiments, θ5 is 1.5°˜6.5°, and θ5 is preferably 1.5°˜3.5°. In addition, in this embodiment, the twisted nematic liquid crystal molecules include photocurable liquid crystal materials, such as RM257, whose molecular structural formula is as follows:

As mentioned above, in a general display device in which the display medium is blue-phase liquid crystal, due to the polarization rotation characteristic of blue-phase liquid crystal, even if the optical axes of the two polarizers are set to be orthogonal (that is, the distance between the optical axes of the two polarizers The included angle is 90°), there will still be a certain degree of light leakage. In view of this, in the first embodiment, by setting the first polarizer 200 and the second polarizer 300 whose optical axis angle x is 90°±θ1, and θ1 is 1°-9°, the display device 10 can be reduced. The phenomenon of light leakage, and the effect of improving the display contrast of the display device 10 .

Therefore, based on the same spirit, in the fourth embodiment, in the case where the first polarizer 200 and the second polarizer 600 are arranged to be perpendicular, by setting the compensation film 900 including a plurality of twisted nematic liquid crystal molecules , wherein the angle c between the third optical axis 903A of the twisted nematic liquid crystal molecule 900A closest to the first polarizer 200 and the fourth optical axis 903B of the twisted nematic liquid crystal molecule 900B closest to the display panel 100 is 0°±θ5, and θ5 is 1°˜9°, can also further reduce the light leakage phenomenon of the display device 40 , and further increase the display contrast of the display device 40 .

FIG. 16 is a schematic diagram of the contrast of the display device 40 in FIG. 14 under various viewing angles. Please refer to FIG. 10 and FIG. 16 at the same time. The center contrast ratio measured by using the display device 40 is 4000, while the center contrast ratio measured by using the existing display device is 1000. In comparison, the display device 40 can display better contrast. In other words, in the display device 40 , by disposing the compensation film 900 , the display contrast of the display device 40 under different viewing angles can be improved.

To sum up, in the display device proposed by the above-mentioned embodiments, by setting the optical film with the optical axis shifted by an angle (for example, θ1-θ5 is 1°-9°), it can effectively reduce the possible light leakage of the display device phenomenon, thereby increasing the display contrast of the display device, and thus improving the display quality of the liquid crystal display.

Claims (12)

1. a display device, it is characterised in that including:

One display floater, including:

One image element array substrates, including multiple pixel cells, each of which pixel cell includes one First electrode and one second electrode, this first electrode is arranged alternately with this second electrode, and this first Between electrode and this second electrode, there is a transverse electric field；

One opposite substrate, is arranged oppositely with this image element array substrates；And

One display medium, is arranged between this image element array substrates and this opposite substrate；

One first polaroid, is arranged on this image element array substrates；And

One second polaroid, is arranged on this opposite substrate, wherein a primary optic axis of this first polaroid with Having one first angle between one second optical axis of this second polaroid, this first angle is 90 ° ± θ 1, and θ 1 It it is 1 °～9 °；

This display medium has tropisms such as an optics, and this display medium by an electric field driven time there is an optics Anisotropy；

This display medium includes blue phase liquid crystal.

Display device the most according to claim 1, it is characterised in that θ 1 is 1.5 °～6.5 °.

Display device the most according to claim 1, it is characterised in that also include a biaxial compensation film, It is arranged on this opposite substrate and between this display floater and this second polaroid, wherein this first polarisation Between this primary optic axis and one the 3rd optical axis of this biaxial compensation film of sheet, there is one second angle, this second folder Angle is 0 ° ± θ 2, and θ 2 is 1 °～9 °.

Display device the most according to claim 3, it is characterised in that θ 1 and θ 2 is identical.

5. a display device, it is characterised in that including:

One display floater, including:

One image element array substrates, including multiple pixel cells, each of which pixel cell includes one First electrode and one second electrode, this first electrode is arranged alternately with this second electrode, and this first Between electrode and this second electrode, there is a transverse electric field；

One opposite substrate, is arranged oppositely with this image element array substrates；And

One display medium, is arranged between this image element array substrates and this opposite substrate；

One first polaroid, is arranged on this image element array substrates；

One second polaroid, is arranged on this opposite substrate, wherein a primary optic axis of this first polaroid with Having one first angle between one second optical axis of this second polaroid, this first angle is 90 °；

One first eurymeric A plate compensate film, be arranged on this image element array substrates and be positioned at this display floater with Between this first polaroid, wherein this primary optic axis of this first polaroid compensates with this first eurymeric A plate One the 5th optical axis of film has one second angle；And

One second eurymeric A plate compensates film, be arranged on this opposite substrate and be positioned at this display floater with this Between two polaroids, wherein this primary optic axis of this first polaroid compensates film with this second eurymeric A plate One the 6th optical axis has one the 3rd angle,

Wherein this second angle is 0 ° of-θ 1, and θ 1 is 1 °～9 °, and the 3rd angle is 0 ° of+θ 2, and θ 2 is 1 °～9 ° Or this second angle is 0 ° of+θ 1, θ 1 is 1 °～9 °, and the 3rd angle is 0 ° of-θ 2, and θ 2 is 1 °～9 °.

Display device the most according to claim 5, it is characterised in that θ 1 and θ 2 is identical.

7. a display device, it is characterised in that including:

One display floater, including:

One image element array substrates, including multiple pixel cells, each of which pixel cell includes one First electrode and one second electrode, this first electrode is arranged alternately with this second electrode, and this first Between electrode and this second electrode, there is a transverse electric field；

One opposite substrate, is arranged oppositely with this image element array substrates；And

One display medium, is arranged between this image element array substrates and this opposite substrate；

One first polaroid, is arranged on this image element array substrates；

One second polaroid, is arranged on this opposite substrate, wherein a primary optic axis of this first polaroid with Having one first angle between one second optical axis of this second polaroid, this first angle is 90 °；And

One compensates film, be arranged on this image element array substrates and be positioned at this display floater and this first polaroid it Between, wherein this compensation film is by multiple Twisted Nematic liquid crystal molecular compositions,

Wherein in those Twisted Nematic liquid crystal molecules, near one first twisted nematic of this first polaroid One the 7th optical axis of type liquid crystal molecule and the one second Twisted Nematic liquid crystal molecule near this display floater One the 8th optical axis there is one second angle, this second angle is 0 ° ± θ, and θ is 1 °～9 °.

Display device the most according to claim 7, it is characterised in that also include that at least one twin shaft is mended Repay film, in order to the light of this display floater outgoing of polarization.

9. a display device, it is characterised in that including:

One display floater, including:

One image element array substrates, including multiple pixel cells；

One opposite substrate, is arranged oppositely with this image element array substrates；And

One display medium, is arranged between this image element array substrates and this opposite substrate；

One first polaroid, is arranged on this image element array substrates；And

One second polaroid, is arranged on this opposite substrate, wherein a primary optic axis of this first polaroid with Between one second optical axis of this second polaroid, there is an angle,

Wherein when this display medium is dextrorotatory material, this angle is more than 90 °, when this display medium is left During rotation material, this angle is less than 90 °.

Display device the most according to claim 9, it is characterised in that wrap in each pixel cell Including one first electrode and one second electrode, this first electrode is arranged alternately with this second electrode, and this first Between electrode and this second electrode, there is a transverse electric field.

11. display devices according to claim 9, it is characterised in that when this display medium is dextrorotation During material, this angle is 90 ° of+θ, and θ is 1 °～9 °.

12. display devices according to claim 9, it is characterised in that when this display medium is left-handed During material, this angle is 90 ° of-θ, and θ is 1 °～9 °.