CN102819142A - Display device - Google Patents

Abstract

The invention relates to a display device, which comprises a light source module, a display module, a guide optical film, a first compensation film and a second compensation film. The light source module has directional light. The display module is arranged above the light source module. The display module comprises a first substrate, a second substrate and a display medium. The first substrate has a first inner surface and a first outer surface. The guide optical film is located on the second outer surface of the second substrate of the display module and has a light incident surface and a light emitting surface, the directional light enters the guide optical film from the light incident surface and is emitted from the light emitting surface to form an emitted light, and an included angle is formed between the emitted light and the light emitting surface. The first compensation film is located on the first outer surface of the first substrate. The second compensation film is positioned between the second substrate and the guide optical film. The invention solves the problems of low penetration rate and high driving voltage when the blue phase liquid crystal is applied to an IPS display module in the prior art.

Description

display device

technical field

The present invention relates to a display device, and in particular to a liquid crystal display device.

Background technique

With the vigorous development of display technology, consumers have higher and higher requirements for display image quality. In addition to the requirements for the resolution, contrast ratio, viewing angle, gray level inversion, and color saturation of the display, the consumers also have high requirements for the display. The specification requirements of the response time (response time) are also increasing day by day.

In order to meet the needs of consumers, display related companies have invested in the development of blue phase liquid crystal displays with fast response characteristics. Taking the blue phase liquid crystal material as an example, it generally needs 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 the in-plane switching IPS (In-Plane Switching) display module to drive the blue phase liquid crystal molecules in the blue phase (blue phase) liquid crystal display.

However, in the electrode design of a typical IPS display module, there are many areas above the electrode that do not have a transverse electric field, so that many liquid crystal molecules in the blue phase liquid crystal display cannot be driven smoothly, resulting in low transmittance of the display module. . If the driving voltage is increased in order to increase the transmittance of the IPS display module, although the transmittance can be increased, the resulting problem is excessive power consumption. Therefore, how to improve the problems of low transmittance and high driving voltage in the blue-phase liquid crystal display is actually a problem that researchers want to solve. In addition, the contrast ratio and viewing angle of blue phase liquid crystal displays still need to be further improved.

Contents of the invention

The invention provides a display device, which can solve the problems of low transmittance and high driving voltage existing in the traditional application of blue-phase liquid crystals to IPS display modules.

The invention provides a display device, which includes a light source module, a display module, a guide optical film, a first compensation film and a second compensation film. The light source module has directional light. The display module is arranged above the light source module, and the display module includes a first substrate, a second substrate and a display medium. The first substrate has a first inner surface and a first outer surface. The second substrate is located opposite to the first substrate and has a second inner surface and a second outer surface. The display medium is located between the first substrate and the second substrate, wherein the display medium is optically isotropic (optically isotropic), and the display medium is optically anisotropic (optically anisotropic) when driven by an electric field, and the directional light enters the display When the module is installed, the directional light is not perpendicular to the first outer surface, and when the directional light exits the display module, the directional light is not perpendicular to the second outer surface. The guiding optical film is located on the second outer surface of the second substrate of the display module and has a light-incident surface and a light-emitting surface. There is an included angle between the light emitting surfaces. The first compensation film is located on the first outer surface of the first substrate. The second compensation film is located between the second substrate and the guiding optical film.

In the present invention, a compensation film is arranged between the upper polarizer and the lower polarizer of the display device. The setting of the compensation film can adjust the polarization state of the directional light incident into the display module, so that the polarization state of the directional light conforms to the direction of the absorption axis of the upper polarizer. In this way, the occurrence of light leakage can be reduced, so as to improve the contrast ratio of the display device and increase the viewing angle of the display device.

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

1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention;

Figure 2A is a schematic diagram showing that the medium is optically isotropic under the condition of no electric field;

Fig. 2B is a schematic diagram showing that the medium has optical anisotropy in an electric field;

3A and 3B are schematic cross-sectional views of a display device according to an embodiment of the present invention;

4A is a schematic cross-sectional view of a first optical film in a display device according to an embodiment of the present invention;

FIG. 4B is a schematic perspective view of the first optical film of FIG. 4A;

5A is a schematic cross-sectional view of a second optical film in a display device according to an embodiment of the present invention;

FIG. 5B is a schematic perspective view of the second optical film of FIG. 5A;

6A is a schematic cross-sectional view of an optical film in a display device according to an embodiment of the present invention;

Fig. 6B is a schematic perspective view of the optical film of Fig. 6A;

7 is an optical path diagram of light passing through the first optical film, the second optical film and the optical film according to an embodiment of the present invention;

8A is a schematic cross-sectional view of an optical film in a display device according to another embodiment of the present invention;

FIG. 8B is a schematic perspective view of the optical film of FIG. 8A;

9A is a schematic cross-sectional view of an optical film in a display device according to yet another embodiment of the present invention;

Fig. 9B is a schematic perspective view of the optical film of Fig. 9A;

10A is a schematic cross-sectional view of an optical film in a display device according to yet another embodiment of the present invention;

FIG. 10B is a schematic perspective view of the optical film of FIG. 10A;

11 and 12 are schematic cross-sectional views of display devices according to several embodiments of the present invention;

Fig. 13 is a diagram of the relationship between the voltage and the transmittance of the blue-phase liquid crystal driven by the transverse electric field of the traditional IPS display module;

Fig. 14A and Fig. 14B are diagrams showing the relationship between the voltage and the light angle of the blue-phase liquid crystal driven by the vertical electric field of the display device of the present invention;

Fig. 15 is a diagram of the relationship between the voltage and the transmittance of the blue-phase liquid crystal driven by the transverse electric field of the traditional IPS display module;

Fig. 16 is a relationship diagram between the voltage and the transmittance of the blue phase liquid crystal driven by the vertical electric field of the display device of the present invention;

Figure 17 is the measurement result of the hysteresis of the blue phase liquid crystal driven by the transverse electric field of the traditional IPS display module;

Fig. 18 is the measurement result of the hysteresis of the blue phase liquid crystal driven by the vertical electric field of the display device of the present invention;

Fig. 19 is a graph showing the relationship between the thickness of the display medium and the voltage of the display device of the present invention;

Fig. 20 is a graph showing the relationship between the voltage and the transmittance of the display device of the present invention under different thickness conditions of the display medium;

21 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention;

Fig. 22 is a schematic perspective view of a light source module and a display module in a display device according to the present invention;

23 is a schematic diagram of a Poincaré sphere in the compensation process of the display device using the compensation film in the dark state according to the first embodiment of the present invention;

Fig. 24 is a contrast ratio contour map measured by the display device of Fig. 21 according to the parameter setting in Table 1;

Fig. 25 is a contrast ratio contour map measured by the display device of Fig. 21 according to the parameter settings in Table 2;

Figure 26 is a contour map of the contrast ratio measured by the display device of Figure 21 according to the parameter settings in Table 3;

Fig. 27 is a contrast ratio contour map measured by the display device of Fig. 21 according to the parameter settings in Table 4;

Figure 28 is a contour map of the contrast ratio measured by the display device of Figure 21 according to the parameter settings in Table 5;

Fig. 29 is a contrast ratio contour map measured by the display device of Fig. 21 according to the parameter settings in Table 6;

30 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention;

31 is a schematic diagram of a Poincaré sphere in the compensation process of the display device using the compensation film in the dark state according to the second embodiment of the present invention;

Figure 32 is a contour map of the contrast ratio measured by the display device of Figure 30 according to the parameter settings in Table 7;

33 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention;

34 is a schematic diagram of a Poincaré sphere in the compensation process of the display device using the compensation film in the dark state according to the third embodiment of the present invention;

Figure 35 is a contour map of the contrast ratio measured by the display device of Figure 33 according to the parameter settings in Table 8;

Figure 36 is a contour map of the contrast ratio measured by the display device of Figure 33 according to the parameter settings in Table 9;

37 is a schematic cross-sectional view of a display device according to a fourth embodiment of the present invention;

38 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a fourth embodiment of the present invention;

Fig. 39 is a contrast ratio contour map measured by the display device of Fig. 37 according to the parameter setting in Table 10;

40 is a schematic cross-sectional view of a display device according to a fifth embodiment of the present invention;

41 is a schematic diagram of a Poincaré sphere in the compensation process of a display device using a compensation film in a dark state according to a fifth embodiment of the present invention;

Fig. 42 is a contrast ratio contour map measured by the display device of Fig. 40 according to the parameter settings in Table 11;

Fig. 43 is a contour map of the bright state measured by the display device of Fig. 40 according to the parameter settings in Table 11;

44 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a fifth embodiment of the present invention;

Fig. 45 is a contrast ratio contour map measured by the display device of Fig. 40 according to the parameter settings in Table 12;

Fig. 46 is a contour map of the bright state measured by the display device of Fig. 40 according to the parameter settings in Table 12;

47 is a schematic cross-sectional view of a display device according to a sixth embodiment of the present invention;

48 is a schematic diagram of a Poincaré sphere in the compensation process of a display device using a compensation film in a dark state according to a sixth embodiment of the present invention;

Figure 49 is a contour map of the contrast ratio measured by the display device of Figure 47 according to the parameter settings in Table 13;

Figure 50 is a contour map of the bright state measured by the display device of Figure 47 according to the parameter settings in Table 13;

51 is a schematic cross-sectional view of a display device according to a seventh embodiment of the present invention;

52 is a schematic diagram of a Poincaré sphere in the compensation process of the display device using the compensation film in the dark state according to the seventh embodiment of the present invention;

Fig. 53 is a contrast ratio contour map measured by the display device of Fig. 51 according to the parameter settings in Table 14;

FIG. 54 is a contour map of the brightness state measured by the display device in FIG. 51 according to the parameter settings in Table 14.

Among them, reference signs:

100: display device

P: display module

B: light source module

201: Vertical electric field

21b: first substrate

22b, 221b: pixel array

231: Compensation film

24b: first optical film

23b: lower polarizer

26a: Light guide plate

26b: light source

20: Display Media

21a: Second substrate

22a, 221a: Counter electrodes

24a: Second optical film

25: Optical film

23a: Upper polarizer

27: Diffusion film

29: eyes

281, 282: Directional light

283: Shoot Rays

31a: the fourth compensation film

31a-1: A plate compensation film

31a-2: C plate compensation film

31b: the third compensation film

V: vertical axis

d: thickness

D1, D2, D3, D4, D5~D8: direction

S1~S10: surface

θ, θ1, θ1', θ2, θ3～θ8: angle

Ψ: polarization angle

Φ: positioning angle

W1~W6, W5’, W5’’, W5-1, W5-2, W6’: side wall

T1～T3, T3': optical structure

p1～p4: Groove width

X, Y, Z: direction

60, 80: alignment slit pattern

70: Alignment protrusion pattern

Detailed ways

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 cross-sectional view of a display device according to an embodiment of the invention. Referring to FIG. 1 , the display device 100 of this embodiment includes a display module P, a light source module B, and a guiding optical film 25 .

The display module P includes a first substrate 21 b , a second substrate 21 a and a display medium 20 .

The first substrate 21b has an inner surface S1 and an outer surface S2, and a pixel array 22b is disposed on the inner surface S1 of the first substrate 21b. The material of the first substrate 21b can be glass, quartz, organic polymer, or other applicable materials. According to this embodiment, the pixel array 22b includes a plurality of scanning lines, a plurality of data lines, and a plurality of pixel units, wherein each pixel unit includes an active element and a pixel electrode electrically connected to the active element, and the active element of the pixel unit is connected to the active element. A corresponding data line is electrically connected with a corresponding scanning line. The above-mentioned active device can be a bottom gate thin film transistor or a top gate thin film transistor.

The second substrate 21a is located opposite to the first substrate 21b. The second substrate 21a has an inner surface S3 and an outer surface S4, and an opposite electrode 22a is disposed on the inner surface S3 of the second substrate 21a. Similarly, the material of the second substrate 21a can be glass, quartz, organic polymer, or other applicable materials. The counter electrode 22a completely covers the inner surface S3 of the second substrate 21a. According to this embodiment, the opposite electrode 22a is a transparent electrode, and its material includes metal oxide, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium germanium zinc oxide, or Other suitable metal oxides, or stacked layers of at least two of the above.

It is worth mentioning that a color filter array can be further provided on the first substrate 21b or the second substrate 21a, so that the display module P can display color images. However, the present invention is not limited thereto.

The display medium 20 is located between the pixel array 22b of the first substrate 21b and the counter electrode 22a of the second substrate 21a. In particular, the display medium 20 is optically isotropic in an environment without an electric field, as shown in FIG. 2A . And when the display medium 20 is in the environment with the vertical electric field 201, it has optically anisotropic properties (optically anisotropic), as shown in FIG. 2B. In other words, when there is no electric field generated between the pixel array 22b and the opposite electrode 22a, the display medium 20 exhibits optical isotropy. When a vertical electric field 201 is formed between the pixel array 22b and the opposite electrode 22a, the display medium 20 exhibits optical anisotropy. According to this embodiment, the above-mentioned display medium 20 includes blue phase liquid crystals, which are, for example, 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). )etc. Since the display medium 20 switches between optical isotropy and optical anisotropy through the formation of an electric field, so that the display medium 20 can function as a light valve, the reaction speed of this display medium 20 is relatively fast. The torsion reaction speed of traditional nematic liquid crystal molecules is much faster.

The light source module B is disposed under the outer surface S2 of the first substrate 21b of the display module P, and generates directional light 281, wherein the directional light 281 refers to a specific light projection direction and a specific light beam angle. In this embodiment The middle directional light 281 is only concentrated in a specific range, that is, it has directionality, instead of the traditional general scattering light source, the light spreads to all sides without any directionality. The aforementioned light source module B is, for example, a side-illuminated light source module, which includes a light guide plate 26a and a light source 26b. Certainly, the light source module B may further include elements such as an optical film set, a frame, and the like. The light source module B in this embodiment is described by taking a side light source module as an example, but the present invention is not limited thereto. According to other embodiments, the light source module B can also be other types of light source modules, such as direct Light source module.

Based on the above, the display medium 20 has an optical anisotropic property in an environment with an electric field. Therefore, when the vertical electric field 201 is formed between the pixel array 22b of the display module P and the opposite electrode 22a, the display medium 20 will not only exhibit optical anisotropic properties, but also appear vertical along the vertical electric field 201. arrangement, as shown in Figure 1 and Figure 2B. In order to make the vertically arranged optically anisotropic display media 20 have birefringence for the light from the light source module B, this embodiment makes a special design for the transmission direction of the light from the light source module B, as described below.

According to this embodiment, the directional light 281 generated by the light source module B has an incident direction D1 when entering the display module P, and the incident direction D1 and the outer surface S2 of the first substrate 21b are not perpendicular to each other. In other words, the directional light 281 generated by the light source module B does not enter the display module P vertically, but enters the display module P at a specific oblique angle. To make the directional light 281 generated by the light source module B exit the light source module B at a specific oblique angle, a special optical microstructure can be designed on the light guide plate 26a, or a layer with a special optical structure can be arranged on the light guide plate 26a. Microstructured optical films. In this way, when the light generated by the light source 26b passes through the light guide plate 26a (or optical film), the transmission direction of the light can be changed, so as to achieve the directional light 281 generated by the light source module B with a specific The oblique angle of the shot is aimed at. According to this embodiment, since the directional light 281 generated by the light source module B is emitted at a specific oblique angle, the included angle θ1 between the incident direction D1 of the directional light 281 and the outer surface S2 of the first substrate 21 b is, for example, 5 degrees to 45 degrees. In other words, the inclination angle θ1' of the directional light 281 generated by the light source module B is, for example, 45 degrees to 85 degrees. The inclination angle θ1' refers to the angle between the incident direction D1 of the directional light 281 and the vertical axis V.

As mentioned above, when the directional light 281 enters the display module P at an inclined angle θ1', the directional light 282 is formed, and the directional light 282 in the display module P still maintains the same direction to go through the display Medium 20. In other words, the directional light 281 generated by the light source module B is a directional light 282 when it enters the display medium 20, and the directional light 282 has an incident direction D2, and the incident direction D2 and the inner surface S1 of the first substrate 21b are different from each other. perpendicular to each other. Therefore, the angle θ between the incident direction D2 of the directional light 282 and the inner surface S1 of the first substrate 21 b is not equal to 90 degrees. According to the present embodiment, the angle θ between the incident direction D2 of the directional light 282 and the inner surface S1 of the first substrate 21b is, for example, 5 degrees to 45 degrees.

Afterwards, when the directional light 282 passes through the display medium 20 and passes through the second substrate 21a, the directional light 282 will be guided by the guiding optical film 25 into an outgoing light 283 having an outgoing direction D3, and the outgoing direction D3 is consistent with the guiding light ray 283. The surface (exit surface) of the optical film 25 substantially forms an included angle of 60° to 120°. In the present embodiment, the outgoing light 283 exits the guiding optical film 25 vertically, so the angle between the outgoing direction D3 and the surface (exiting surface) of the guiding optical film 25 is substantially 90 degrees, so that the user's eyes 29 receive The outgoing light 283 is forward light. Therefore, the included angle θ2 between the outgoing direction D3 of the outgoing light 283 and the surface (exiting surface) of the guiding optical film 25 is substantially equal to 90 degrees.

In this embodiment, in order to keep the directional light 281 in the same advancing/transmitting direction as much as possible before entering the display medium 20, a first optical film 24b may be further provided on the outer surface S2 of the first substrate 21b. In addition, in order to keep the directional light 282 in the same advancing/transmitting direction after leaving the display medium 20 , a second optical film 24 a may be further provided on the outer surface S4 of the second substrate 21 b.

Please refer to FIG. 1 and FIG. 4A and FIG. 4B at the same time, the first optical film 24b is disposed on the outer surface S2 of the first substrate 21b. In particular, the first optical film 24b has a plurality of first optical structures T1, and the first optical structures T1 can make the directional light 281 pass through substantially without total reflection, that is, the directional light 281 passes through the first The first optical structure T1 of the optical film 24b is directly transparent. If the directional light 281 directly passes through the first optical structure T1 of the first optical film 24b without total reflection or other refraction, then the loss of the directional light 281 by the first optical film 24b can be minimized , that is to prevent the directional light 281 from being lost at the interface between the air and the first substrate 21 b due to reflection. In this way, the directional light 281 can pass through the first optical film 24b in the same transmission direction as much as possible.

According to this embodiment, the first optical film 24b has a first surface S5 and a second surface S6 opposite to the first surface S5, the first surface S5 is facing the light source module B, and the second surface S6 is facing the outer surface of the first substrate 21b. The surface S2, and the first optical structure T1 is located on the first surface S5. In other words, the second surface S6 of the first optical film 24b in this embodiment is a flat plane, but the present invention is not limited thereto. In addition, the first optical structure T1 on the first surface S5 of the first optical film 24b can make the directional light 281 of the light source module B directly penetrate the first optical film 24b as much as possible.

According to this embodiment, the above-mentioned first optical structure T1 is a groove structure, which has a first sidewall W1 and a second sidewall W2 , as shown in FIG. 4A . The incident direction D1 of the directional light 281 when passing through the first optical film 24 b is substantially perpendicular to the first sidewall W1 , and the incident direction D1 is substantially parallel to the second sidewall W2 . More specifically, in the first optical structure (groove structure) T1 of this embodiment, the first sidewall W1 of the groove structure T1 is a short sidewall and the second sidewall W2 is a long sidewall, and the short sidewall The wall W1 is substantially perpendicular to the incident direction D1 of the directional light 281 . In addition, the refractive index of the first optical film 24b is close to the refractive index of the first substrate 21b. In this way, when the directional light 281 passes through the first optical structure (groove structure) T1, the directional light 281 can directly pass through the short sidewall W1 without total reflection or refraction, so that the directional light 281 can As much as possible, directly penetrate the first optical film 24b. In this embodiment, the groove width p1 of the first optical structure (groove structure) T1 is about 5 μm˜100 μm. The angle θ4 between the first sidewall W1 of the first optical structure (groove structure) T1 and the vertical axis V is about 5 degrees to 45 degrees. The angle θ3 between the second sidewall W2 of the first optical structure (groove structure) T1 and the vertical axis V is about 45 degrees to 85 degrees.

Next, please refer to FIG. 1 and FIG. 5A and FIG. 5B at the same time, the second optical film 24a is disposed on the outer surface S4 of the second substrate 21a. In particular, the second optical film 24a has a plurality of second optical structures T2, and the second optical structures T2 can make the directional light 282 pass through substantially without total reflection, that is, the directional light 282 passes through the second The second optical structure T2 of the optical film 24a is direct transmission. If the directional light 282 passes directly through the second optical structure T2 of the second optical film 24a without total reflection, then the loss of the directional light 282 by the second optical film 24a can be minimized, that is, it can be avoided. The directional light 282 is lost at the interface between the air and the second optical film 24a due to reflection. In this way, the directional light 282 can exit the second optical film 24a in the same transmission direction as much as possible.

According to the present embodiment, the second optical film 24a has a first surface S7 and a second surface S8 opposite to the first surface S7, the first surface S7 is facing the outer surface S4 of the second substrate 21a, and the second optical structure T2 is located on the second surface S8. In other words, the first surface S7 of the second optical film 24a is a flat plane, but the present invention is not limited thereto. The second optical structure T2 on the second surface S8 of the second optical film 24a can make the directional light 282 directly pass through the second optical film 24a as much as possible.

According to this embodiment, the above-mentioned second optical structure T2 is a groove structure, which has a first sidewall W3 and a second sidewall W4 , as shown in FIG. 5A . The incident direction D2 of the directional light 282 passing through the second optical film 24 a is perpendicular to the first sidewall W3 , and the third incident direction D2 is parallel to the second sidewall W4 . More specifically, in the second optical structure (groove structure) T2 of this embodiment, the first sidewall W3 is a short sidewall and the second sidewall W4 is a long sidewall, and the short sidewall W3 is related to the directivity The incident direction D2 of the light 282 is substantially vertical. In addition, the refractive index of the second optical film 24a is close to the refractive index of the second substrate 21a. In this way, when the directional light 282 passes through the second optical structure (groove structure) T2, the directional light 282 can directly pass through the short sidewall W3 without total reflection or refraction, so that the directional light 282 can be as far as possible Possibly directly through the second optical film 24a. In this embodiment, the groove width p2 of the second optical structure (groove structure) T2 is about 5 μm˜100 μm. The angle θ6 between the first sidewall W3 of the second optical structure (groove structure) T2 and the vertical axis V is about 5 degrees to 45 degrees. The angle θ5 between the second sidewall W4 of the second optical structure (groove structure) T2 and the vertical axis V is about 45 degrees to 85 degrees.

Afterwards, please refer to FIG. 1 and FIG. 6A and FIG. 6B at the same time, the guiding optical film 25 is disposed on the second optical film 24a. The guiding optical film 25 has a plurality of guiding optical structures T3, and the guiding optical structures T3 can make the directional light 282 substantially totally reflect on the guiding optical structures T3 to form the outgoing light 283, so that the outgoing light 283 can pass through There is an included angle of 60-120 degrees between the emission direction D3 after guiding the optical film 25 and the surface (emission surface) S10 of the guiding optical film 25 . In this embodiment, the emitting direction D3 of the outgoing light 283 after passing through the optical guiding film 25 and the surface (exiting surface) S10 of the optical guiding film 25 are substantially perpendicular to each other. In other words, the directional light 282 is totally reflected as much as possible on the guiding optical structure T3 of the guiding optical film 25 to form the outgoing light 283 . In other words, the design of the guide optical structure T3 of the guide optical film 25 is mainly to guide the directional light rays 281 , 282 emitted from the light source module B after passing through the guide optical film 25 to correct their transmission/progressing directions. In this way, the outgoing light 283 can vertically exit the guiding optical film 25 so as to be received by the user's eyes 20 .

According to this embodiment, the guiding optical film 25 has a first surface S9 (also referred to as a light incident surface) and a second surface S10 (also referred to as a light exit surface) opposite to the first surface S9, the first surface S9 is facing The outer surface S4 of the second substrate 21a and the guiding optical structure T3 are located on the first surface S9. In other words, the second surface S10 of the guiding optical film 25 is a flat plane, but the invention is not limited thereto. The guiding optical structure T3 on the first surface S9 of the guiding optical film 25 can make the directional light 282 generate total reflection as much as possible to form the outgoing light 283 .

According to this embodiment, the guiding optical structure T3 is a groove structure, which has a first sidewall W5 and a second sidewall W6, as shown in FIG. 6A . In this embodiment, the first sidewall W5 and the second sidewall W6 of the groove structure T3 are both planar sidewalls. More specifically, in the optical structure (groove structure) T3 of this embodiment, the angle θ7 between the first side wall W5 and the vertical axis V is about 5 degrees to 60 degrees, and the second side wall W6 and the vertical axis V The angle θ8 between V is about 15 degrees to 45 degrees. Therefore, when the directional light 282 hits the optical film 25, the directional light 282 can be totally reflected on the first side wall W5 of the guiding optical structure T3 to form the outgoing light 283, so that the outgoing light 283 can exit the guiding light 283 vertically. Optical film 25. In addition, in this embodiment, the groove width p3 of the optical structure (groove structure) T3 is about 5 μm˜100 μm.

FIG. 7 shows the light path of the directional light rays 281 and 282 of the light source module B passing through the first optical film 24b, the second optical film 24a and the guiding optical film 25 to form the outgoing light 283. In order to clearly show the directional light rays 281, directional light ray 282, and outgoing light ray 283 respectively pass through the optical paths of the first optical film 24b, the second optical film 24a, and the guiding optical film 25. FIG. 7 only shows the first optical film 24b, the second optical film 24a, and Guide the optical film 25 , that is, the display module P and other film layers are omitted.

Based on the above, as shown in FIG. 7 , when the directional light 281 passes through the first optical film 24 b, it passes through as directly as possible without total reflection or refraction. Then, when the directional light 282 passes through the second optical film 24a, it also directly passes through as much as possible without total reflection or refraction. Afterwards, the directional light 282 is totally reflected as much as possible on the guiding optical structure T3 of the guiding optical film 25 to form the outgoing light 283 . Through the arrangement of the first optical film 24b, the second optical film 24a and the guiding optical film 25, the light from the light source module B can enter the display module P in an oblique direction, and then exit the guiding optical film 25 in a forward direction.

Referring to FIG. 1 again, the display device 100 of this embodiment may further include a lower polarizer 23 b and an upper polarizer 23 a in addition to the above-mentioned display module P, light source module B and optical guide film 25 . The lower polarizer 23b is disposed between the first substrate 21b and the first optical film 24b, and the upper polarizer 23a is disposed between the second substrate 21a and the second optical film 24a. The lower polarizer 23b and the upper polarizer 23a can be made of dichroic polymer films, such as polyvinyl-alcohol-based films. The angle between the transmission axis (transmission axis) of the lower polarizer 23b and the transmission axis (transmission axis) of the upper polarizer 23a may be 5 degrees to 175 degrees.

In addition, in order to make the display module P have better display quality, the display module P of this embodiment further includes a compensation film 231 and a diffusion film 27 . The compensation film 231 is disposed between the lower polarizer 23b and the upper polarizer 23a. In this embodiment, the compensation film 231 is disposed between the lower polarizer 23b and the first substrate 21b as an example for illustration. In other words, the compensation film (not shown) can also be arranged between the upper polarizer 23a and the second substrate 21a, or the compensation film 231 is arranged between the lower polarizer 23b and the first substrate 21b and the upper polarizer 23a and the second substrate 21b A compensation film (not shown) is disposed between the two substrates 21a. Providing the compensation film 231 can increase the contrast performance of the display module P and increase the viewing angle of the display module P. Referring to FIG. In addition, the diffusion film 27 is disposed above the upper polarizer 23a, so as to diffuse the emitted light 283 when passing through, so that the display module P has better display quality. However, the present invention does not limit that the diffusion film 27 must be used.

Based on the above, since the display medium 20 of the display module P of this embodiment is driven by the vertical electric field 201 between the pixel array 22b and the counter electrode 22a, it can solve the problem that the traditional IPS display module uses a horizontal electric field to drive the blue phase liquid crystal. The problems of low transmittance and high driving voltage exist in the time. In addition, since the incident direction D2 of the directional light 281 and the directional light 282 generated by the light source module B of this embodiment is not perpendicular to the surface of the first substrate 21b when entering the display medium 20, the display medium 20 can When driven to be optically anisotropic, the directional light 282 relative to the light source module B still has a birefringence property, thereby enabling the display module P to display images.

In the above embodiment of FIG. 1 , the upper polarizer 23a is disposed between the second substrate 21a and the second optical film 24a. In this way, the polarization state of the directional light 282 is less affected by the second optical film 24 a and the guiding optical film 25 . However, the present invention is not limited thereto. According to other embodiments, the upper polarizer 23a may also be disposed above the second optical film 24a or the guide optical film 25, as shown in FIG. 3A.

In addition, according to another embodiment, the second optical film 24b may also be omitted in the display module P, as shown in FIG. 3B . In this way, the polarization state of the directional light 282 is less affected by the second optical film 24a. However, the present invention is not limited thereto.

In addition, in the above embodiment of FIG. 1 , the optical film 25 of the display module P adopts the structure shown in FIG. 6A and FIG. 6B . However, the present invention is not limited thereto. According to other embodiments, the optical film 25 of the display device 100 may also adopt other forms or structures, as described below.

8A is a schematic cross-sectional view of an optical film in a display device according to another embodiment of the present invention. FIG. 8B is a schematic perspective view of the optical film of FIG. 8A . Please refer to FIG. 8A and FIG. 8B, the guiding optical structure T3' of the guiding optical film 25 of this embodiment is a groove structure, the first side wall W5' of the optical structure (groove structure) T3 is a curved side wall, and the optical structure (Groove structure) The second sidewall W6' of T3' is a plane sidewall. Therefore, when the directional light 282 hits the optical film 25, the directional light 282 can be totally reflected on the first side wall (curved side wall) W5' of the guiding optical structure T3 to form the outgoing light 283, so that the outgoing light 283 can exit the guiding optical film 25 vertically. In particular, since the first side wall W5' is a curved side wall, in addition to the total reflection of the directional light 282 on the first side wall (curved side wall) W5' to form the outgoing light 283, part of the directional light is totally reflected. After the outgoing light 283 is reflected on the first side wall (curved side wall) W5 ′, the incident angle is smaller than the total reflection angle, and exits the optical film 25 in the form of refraction. Therefore, if the first side wall W5' of the optical structure (groove structure) T3' adopts a curved side wall structure, the outgoing direction of the outgoing light 283 can have an included angle of 60°-120° with the outgoing surface. That is, the emitted light 283 can be emitted in a divergent form, so that the image quality is better. Similarly, in this embodiment, the groove width p4 of the optical structure (groove structure) T3' is about 5 micrometers to 100 micrometers.

In the above-mentioned embodiment of FIG. 8A and FIG. 8B , the curvature radii of the curved sidewalls W5 ′ of all guiding optical structures T3 ′ of the guiding optical film 25 are the same. Therefore, the guiding optical film 25 of the embodiment of FIG. 8A and FIG. 8B Each guide optical structure T3' has the same groove pattern. However, the present invention is not limited thereto, and according to other embodiments, the optical structures of the guiding optical film 25 may also have different patterns, as shown in FIG. 9A and FIG. 9B .

FIG. 9A is a schematic cross-sectional view of an optical film in a display device according to another embodiment of the present invention. FIG. 9B is a schematic perspective view of the optical film of FIG. 9A . Please refer to FIG. 9A and FIG. 9B. In this embodiment, each guiding optical structure T3' of the guiding optical film 25 has a plane side wall and a curved side wall, but the curvature of the curved side wall of the guiding optical structure T3' The radii of curvature of the side walls are not all the same. For example, the radius of curvature of the curved sidewall W5' of the guiding optical structure T3' in this embodiment is different from the radius of curvature of the curved sidewall W5", and the guiding optical structure T3' of the curved sidewall W5' having a larger radius of curvature and The guiding optical structures T3' having curved sidewalls W5'' with smaller radii of curvature are arranged alternately.

10A is a schematic cross-sectional view of an optical film in a display device according to another embodiment of the present invention. FIG. 10B is a schematic perspective view of the optical film of FIG. 10A . Please refer to FIG. 10A and FIG. 10B. In this embodiment, each guiding optical structure T3' of the guiding optical film 25 has a plane side wall and a curved side wall, and each curved side wall of the guiding optical structure T3' has There are multiple radii of curvature, and the radii of curvature of the curved sidewalls near the bottom of the groove structure T3 ′ gradually become smaller. For example, the first sidewall of the groove structure T3' of the guiding optical film 25 is a curved sidewall, which includes a curved sidewall W5-1 and a curved sidewall W5-2, and the radius of curvature of the curved sidewall W5-1 Less than the radius of curvature of the curved side wall W5-2. Here, for the sake of clarity, this embodiment is illustrated by taking two curved sidewalls W5-1 and W5-2 with different curvatures as an example, but in fact guide the first side of the groove structure T3' of the optical film 25 The walls are continuous surfaces.

As mentioned above, when the directional light 282 hits the guiding optical film 25, in addition to the total reflection of the directional light 282 on the curved side walls W5-1 and W5-2 to form the outgoing light 283, part of the outgoing light 283 can be After being further reflected on the curved side wall W5-1, it exits the optical film 25 in the form of refraction. Since the radius of curvature of the curved sidewall W5-1 closer to the bottom of the groove structure T3' is smaller, the angle between the tangent of the curved sidewall W5-1 and the transmission direction of the outgoing light 283 is smaller, so that After being reflected there, the outgoing light 283 is easily refracted and exits the optical film 25 . In other words, the curved sidewall W5 - 1 with a smaller radius of curvature can make more outgoing light 283 refracted there and exit the optical film 25 . In other words, the divergence angle and distribution of the light guided to the optical film 25 in FIG. 10A and FIG. 10B are larger and wider than those in the embodiment in FIG. 8A and FIG. 8B .

11 and 12 are schematic cross-sectional views of display devices according to several embodiments of the present invention. The embodiment shown in FIG. 11 and FIG. 12 is similar to the embodiment shown in FIG. 1 , so the same components are denoted by the same symbols and will not be described again. The embodiment of FIG. 11 is different from the embodiment of FIG. 1 in that the pixel array 221b has an alignment slit pattern 60, and an alignment protrusion pattern 70 is disposed on the opposite electrode 221a. Setting the alignment slit pattern 60 on the pixel array 221 b and the alignment protrusion pattern 70 on the counter electrode 221 a can change the distribution of the vertical electric field 202 , thereby achieving multi-domain alignment on the display medium 20 . Similarly, the difference between the embodiment of FIG. 12 and the embodiment of FIG. 1 lies in that the pixel array 221 b has an alignment slit pattern 60 , and the opposite electrode 221 a has an alignment slit pattern 80 . Setting the alignment slit pattern 60 on the pixel array 221 b and the alignment slit pattern 80 on the counter electrode 221 a can also change the distribution of the vertical electric field 202 , thereby achieving multi-domain alignment on the display medium 20 .

11 and 12 above, the alignment pattern (such as alignment slit pattern or alignment protrusion pattern) is provided on the pixel array 221b and the opposite electrode 221a, but the present invention is not limited thereto. According to other embodiments, an alignment pattern (such as an alignment slit pattern or an alignment protrusion pattern) may be provided only on the pixel array 221b, or an alignment pattern (such as an alignment slit pattern or an alignment protrusion pattern) may be provided only on the opposite electrode 221a. ). In addition, the combination of the alignment patterns on the pixel array 221b and the opposite electrode 221a is not limited to the embodiments shown in FIG. 11 and FIG. 12 . In other words, an alignment protrusion pattern can be provided on the pixel array 221b and an alignment slit pattern can be provided on the opposite electrode 221a, or an alignment protrusion pattern can be provided on the pixel array 221b and an alignment protrusion pattern can be provided on the opposite electrode 221a.

In order to illustrate that the display device of the present invention has lower driving voltage and better transmittance than the conventional IPS display device, several examples are used below to compare with the conventional IPS display device.

Comparison of driving voltage I

FIG. 13 is a graph showing the relationship between the voltage and the transmittance of the blue-phase liquid crystal driven by the transverse electric field of the traditional IPS display module. Please refer to FIG. 13 , the horizontal axis of FIG. 13 represents the voltage (V), and the vertical axis represents the penetration of the display module. It can be seen from Figure 13 that when the blue-phase liquid crystal is driven by a traditional IPS display module, its driving voltage needs to be as high as 52V to have better penetration, that is, when the driving voltage needs to reach 52V, the display module can have a Kerr constant value (Kerr constant) is 12.68nm/V ² .

FIG. 14A and FIG. 14B are graphs showing the relationship between the voltage and the light angle for driving the blue-phase liquid crystal by the vertical electric field of the display device of the present invention. The horizontal axis of FIG. 14A and FIG. 14B represents the inclination angle of light from the light source module (that is, the angle θ1' shown in FIG. 1 ), and the vertical axis represents the voltage (V).

Referring to FIG. 14A first, the display medium thickness (also known as cell gap) of the display module in the display device is 3.5 microns, and the display module in FIG. 14A has a Kerr constant of 12.68nm/V ² . It can be seen from FIG. 14A that the driving voltage (less than 15V) required by the display module in FIG. 14A is much lower than the driving voltage (52V) of the IPS display module in FIG. 13 . In addition, in the display device of FIG. 14A , when the inclination angle of the light from the light source module is larger, its driving voltage is smaller.

Please refer to FIG. 14B first. The display medium thickness (also known as unit cell gap) of the display module in this display device is 5 microns, and the display module in FIG. 14B also has a Kerr constant value (Kerr constant) of 12.68nm/V ² . It can be seen from FIG. 14B that the driving voltage (less than 18V) required by the display module in FIG. 14B is still far lower than the driving voltage (52V) of the IPS display module in FIG. 13 . Similarly, in the display device shown in FIG. 14B , when the inclination angle of light from the light source module is larger, its driving voltage is smaller.

Comparison of Driving Voltage II

FIG. 15 is a graph showing the relationship between the voltage and the transmittance of the blue-phase liquid crystal driven by the transverse electric field of the traditional IPS display module. Please refer to FIG. 15 , the horizontal axis of FIG. 15 represents the voltage (V), and the vertical axis represents the penetration of the display module. In FIG. 15 , the laser light of 633nm is used as the light of the light source module, and the laser light is injected into the IPS display module in a vertical direction. It can be seen from FIG. 15 that when the driving voltage is as high as 193Vrms, the display module can have the maximum transmittance.

Fig. 16 is a graph showing the relationship between the voltage and the transmittance of the blue-phase liquid crystal driven by the vertical electric field of the display device of the present invention. Please refer to FIG. 16 , the horizontal axis of FIG. 16 represents the voltage (V), and the vertical axis represents the penetration of the display module. In Fig. 16, the 633nm laser light is used as the light of the light source module, t represents the thickness of the display medium (also known as the unit cell gap), and θ represents the light inclination angle of the light source module (that is, the angle θ1' shown in Fig. 1 ). It can be seen from FIG. 16 that under the combination of different dielectric thicknesses (also known as unit cell gaps) and different light inclination angles, four kinds of relationship curves between voltage and transmittance can be obtained. However, in the above four curves, the driving voltage required to make the display module have the highest penetration is much lower than the driving voltage (193Vrms) required by the traditional IPS display module.

Comparison of Hysteresis

Generally, blue-phase liquid crystals have hysteresis, and when blue-phase liquid crystals are used in the display medium of a display device, it is usually necessary to suppress or reduce their hysteresis, so as to avoid the hysteresis of blue-phase liquid crystals from affecting the gray scale of the display module. control accuracy.

Fig. 17 is the measurement result of the hysteresis phenomenon of the blue phase liquid crystal driven by the transverse electric field of the traditional IPS display module. Fig. 18 is the measurement result of the hysteresis phenomenon of the blue phase liquid crystal driven by the vertical electric field of the display device of the present invention. Generally speaking, the method of measuring the hysteresis of the blue phase liquid crystal is to gradually increase the voltage to measure the voltage and penetration curve M, M', and gradually decrease the voltage to measure the voltage and penetration curve N, N '. Then calculate the voltage difference between the two curves M and N (M', N') under the condition of half the penetration. If the voltage difference between the two curves M and N (M', N') is larger, it means that the hysteresis of the blue phase liquid crystal is more obvious. Conversely, if the voltage difference between the two curves M and N (M', N') is smaller, it means that the hysteresis of the blue phase liquid crystal is smaller.

It can be seen from Figure 17 and Figure 18 that the hysteresis phenomenon of blue phase liquid crystal driven by the transverse electric field of the traditional IPS display module is relatively high, because the voltage difference of curves M and N (Figure 17) under the condition of half penetration is significantly larger than that of curve M ', N' (Fig. 18) the voltage difference under the condition of half penetration.

Showing the Effect of Dielectric Thickness on Driving Voltage

Fig. 19 is a graph showing the relationship between the thickness of the display medium and the voltage of the display device of the present invention. The horizontal axis of FIG. 19 represents the thickness of the display medium (or cell gap), and the vertical axis represents the voltage (V). In Fig. 19, the 550nm laser light is used as the light of the light source module, and θ represents the light inclination angle of the light source module (that is, the angle θ1' shown in Fig. 1), and the four curves in Fig. It has a Kerr constant value (Kerr constant) of 10.2nm/V ² . It can be known from FIG. 19 that the smaller the thickness of the display medium (or cell gap), the smaller the required driving voltage.

FIG. 20 is a graph showing the relationship between the voltage and the transmittance of the display device of the present invention under different thickness conditions of the display medium. The horizontal axis of FIG. 20 represents voltage (V), and the vertical axis represents penetration. In Fig. 20, the thickness of the display medium (or cell gap) is 1, 2, and 5 microns respectively, and it uses 550nm laser light as the light of the light source module, and the light inclination angle of the light source module is 70 degrees ( That is, the angle θ1' shown in FIG. 1). It can be seen from FIG. 20 that the driving voltage of the display device of the present invention is related to the thickness of the display medium.

Based on the above, the display module of the present invention generates a vertical electric field between the pixel array and the electrode layer to drive the display medium of the display module. In particular, since the incident direction of the light generated by the light source module is not perpendicular to the inner surface of the first substrate when it enters the display medium, the light rays relative to the light source module can remain the same when the display medium is driven to be optically anisotropic. With birefringence properties. Based on the above, since the display device of the present invention can use a vertical electric field to drive the display medium, it can solve the problems of low transmittance and high driving voltage that traditionally use a horizontal electric field to drive blue-phase liquid crystals.

In addition, the display device of the present invention can further include a plurality of compensation films, and the display quality of the display device can be increased through the arrangement of the plurality of compensation films. The advantages of disposing the compensation film will be described below with reference to the first embodiment to the seventh embodiment. It should be noted that the display device in the following embodiments is similar to the above-mentioned embodiment of FIG. 1 , so the same components are denoted by the same symbols, and will not be described again. For omitted parts, please refer to the above-mentioned embodiments. The differences will be further explained below.

first embodiment

FIG. 21 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention. Referring to FIG. 21 , the difference between the display device 100 a and the embodiment shown in FIG. 1 is that the display device 100 a includes the first compensation film 28 b and the second compensation film 28 a, and does not include the compensation film 231 . In detail, the first compensation film 28 b is located on the outer surface S2 of the first substrate 21 b, and the second compensation film 28 a is located between the second substrate 21 a and the guiding optical film 25 .

In this embodiment, the lower polarizer 23b is located on the outer surface S2 of the first substrate 21b, and the upper polarizer 23a is located on the outer surface S4 of the second substrate 21a. According to this embodiment, the lower polarizer 23b is located between the first compensation film 28b and the first optical film 24b, the upper polarizer 23a is located between the second compensation film 28a and the second optical film 24a, and the second optical film 24a is located between the optical film 25 and the upper polarizer 23a. According to this embodiment, the directional light 282 passes through the lower polarizer 23b, the first compensation film 28b, the second compensation film 28a and the upper polarizer 23a in sequence.

According to this embodiment, the first compensation film 28b and the second compensation film 28a can be used to adjust the polarization state of the directional light 282 in the display module P, and make the polarization state of the directional light 282 conform to the upper polarizer 23a after adjustment. The direction of the absorption axis. Accordingly, the light leakage phenomenon generated when the directional light 282 forms the outgoing light 283 can be reduced, and the contrast ratio of the display device 100a in the dark state can be further improved.

To further illustrate the functions of the first compensation film 28b and the second compensation film 28a, the compensation process of the first compensation film 28b and the second compensation film 28a will be described below using a Poincarésphere. Before this, in order to clearly define the direction of the directional light 281 and the direction of the directional light 282, and the absorption axis angles of the upper polarizer 23a, the lower polarizer 23b, the first compensation film 28b and the second compensation film 28a, the polarization angle will be used below Ψ(polar angle) and positioning angle Φ are defined, and the detailed description is as follows.

FIG. 22 is a schematic perspective view of a light source module and a display module in a display device according to the present invention. Please refer to FIG. 22 , taking the center of the display module P as a reference, the angle between the projection line of any direction D4 on the XY plane and the X direction is the positioning angle Φ. The angle between any direction D4 and the Z direction is the polarization angle Ψ. For example, the polarization angle Ψ of the direction D5 is 90 degrees and the orientation angle Φ is 0 degrees; the polarization angle Ψ of the direction D6 is 90 degrees and the orientation angle Φ is 90 degrees; the polarization angle Ψ of the direction D7 is 90 degrees and the orientation angle Φ is 180 degrees; the polarization angle Ψ of the direction D8 is 90 degrees and the orientation angle Φ is 270 degrees.

FIG. 23 is a schematic diagram of a Poincaré sphere in the compensation process of the display device using the compensation film in the dark state according to the first embodiment of the present invention. Please refer to FIG. 23, when the polarization angle Ψ of the directional light 282 is 70 degrees and the direction angle Φ is 270 degrees, the effective angle between the lower polarizer 23b and the upper polarizer 23a changes, therefore, the penetration of the directional light 282 The state _P1 is separated from the state _A1 of the absorption axis of the upper polarizer 23a, causing a light leakage phenomenon. According to this embodiment, the first compensation film 28b can rotate the polarization state of the directional light 282 from the P ₁ state to the P ₀ state, and the second compensation film 28a can rotate the polarization state of the directional light 282 from the P ₀ state to the A state. ₁ state. Accordingly, when the directional light 282 passes through the first compensation film 28b and the second compensation film 28a, the polarization state of the directional light 282 can be rotated from the P ₁ state to the A ₁ state, thereby avoiding light leakage.

Table 1 is the parameter setting data of each component in the display device 100a, where Nz is the refractive index anisotropy ratio, and its calculation formula is as follows:

Nz=(n _x -n _z )/(n _x -n _y )

Among them, n _x is the refractive index of the x-axis, _ny is the refractive index of the y-axis, and n _z is the refractive index of the z-axis. d(n _{x -ny} ) is the phase difference value, and the incident light is the directional light 281 . FIG. 24 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 1. FIG.

Table I

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=45 degrees The first compensation film Φ=38.5 degrees Nz=0.54 d(n _x -n _y )=256nm Second compensation film Φ=-38.5 degrees Nz=0.54 d(n _x -n _y )=256nm upper polarizer Φ=-45 degrees

Please refer to FIG. 24 , the four contour lines from the outer side to the inner side represent the contour lines with contrast ratios of 100, 200, 500 and 1000, respectively. It can be seen from Figure 24 that the viewing cone (viewing cone) with a contrast ratio greater than 1000:1 is about 20 degrees, and the viewing cone of 20 degrees has directivity for collimation in a vertical field switching VFS (Vertical Field Switching) blue-phase liquid crystal display 282 rays is enough. In order to widen the viewing angle, the front diffuser film 27 or the curved guide optical film 25 can be used to distribute the collimated backlight to achieve a wide viewing angle. However, the present invention is not limited thereto. Other parameter settings are listed below to obtain an optimized contrast ratio.

Table 2 is the parameter setting data of each component in the display device 100a. FIG. 25 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 2.

Table II

incident light Ψ=60 degrees Φ=270 degrees λ=550nm lower polarizer Φ=45 degrees The first compensation film Φ=42 degrees Nz=0.63 d(n _x -n _y )=260nm Second compensation film Φ=-42 degrees Nz=0.63d (n _x -n _y )=260nm upper polarizer Φ=-45 degrees

The area of the contour line with a contrast ratio of 1000:1 in Figure 25 is larger than the area of the contour line with a contrast ratio of 1000:1 in Figure 24. However, a smaller polarization angle of the incident light results in a higher driving voltage.

Table 3 is the parameter setting data of each component in the display device 100a. FIG. 26 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 3.

Table three

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=40 degrees The first compensation film Φ=36 degrees Nz=0.506 d(n _x -n _y )=259nm Second compensation film Φ=-36 degrees Nz=0.506 d(n _x -n _y )=259nm upper polarizer Φ=-40 degrees

Table 4 is the parameter setting data of each component in the display device 100a. FIG. 27 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 4. Figure 27 shows the contours of the optimized contrast ratio for an incident ray with a polarization angle Ψ of 70 degrees and an orientation angle Φ of 270 degrees.

Table four

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=30 degrees The first compensation film Φ=29.75 degrees Nz=0.399 d(n _x -n _y )=272nm Second compensation film Φ=-29.75 degrees Nz=0.399 d(n _x -n _y )=272nm upper polarizer Φ=-30 degrees

Table 5 is the parameter setting data of each component in the display device 100a. FIG. 28 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 5. FIG. Figure 28 is a contour line of optimized contrast ratio for an incident ray with a polarization angle Ψ of 70 degrees and an orientation angle Φ of 270 degrees.

Table five

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=30 degrees The first compensation film Φ=31 degrees Nz=0.44 d(n _x -n _y )=264nm Second compensation film Φ=-31 degrees Nz=0.44 d(n _x -n _y )=264nm upper polarizer Φ=-30 degrees

Table 6 is the parameter setting data of each component in the display device 100a. FIG. 29 is a contour map of the contrast ratio measured by the display device in FIG. 21 according to the parameter settings in Table 6. FIG. Figure 29 shows the contours of the optimized contrast ratio for an incident ray with a polarization angle Ψ of 60 degrees and an orientation angle Φ of 270 degrees.

Table six

incident light Ψ=60 degrees Φ=270 degrees λ=550nm lower polarizer Φ=30 degrees The first compensation film Φ=32.5 degrees Nz=0.4775 d(n _x -n _y )=264.5nm Second compensation film Φ=-32.5 degrees Nz=0.4775 d(n _x -n _y )=264.5nm upper polarizer Φ=-30 degrees

second embodiment

FIG. 30 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention. Referring to FIG. 30 , the display device 100b of this embodiment is similar to the display device 100a of the first embodiment, the difference is that the display device 100b further includes a third compensation film 31b and a fourth compensation film 31a. The third compensation film 31b is located between the first compensation film 28b and the lower polarizer 23b, and the fourth compensation film 31a is located between the second compensation film 28a and the upper polarizer 23a.

According to this embodiment, the third compensation film 31b and the fourth compensation film 31a are, for example, biaxial compensation films respectively. The third compensation film 31b and the fourth compensation film 31a can be designed according to different positioning angles Φ, so as to compensate for the angle difference between the upper polarizer 23a and the lower polarizer 23b. According to this embodiment, the directional light 282 passes through the lower polarizer 23b, the third compensation film 31b, the first compensation film 28b, the second compensation film 28a, the fourth compensation film 31a and the upper polarizer 23a in sequence.

31 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a second embodiment of the present invention. Please refer to FIG. 31 , in this embodiment, the P ₂ state deviates from the P ₁ state, wherein the P ₂ state represents the polarization state when the orientation angle Φ is 300 degrees, and the P ₁ state represents the polarization state when the orientation angle Φ is 270 degrees polarization state. In this embodiment, the third compensation film 31b can rotate the polarization state from the P ₂ state to the P ₁ state. Next, the first compensation film 28 b and the second compensation film 28 a can rotate the polarization state from the P ₁ state to the A ₁ state. Afterwards, the fourth compensation film 31a can rotate the polarization state from the _A1 state to the _A2 state conforming to the absorption axis of the upper polarizer 23a.

Table 7 is the parameter setting data of each component in the display device 100b. FIG. 32 is a contour map of the contrast ratio measured by the display device in FIG. 30 according to the parameter settings in Table 7. FIG.

Table Seven

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=30 degrees The third compensation film Φ=25.75 degrees Nz=0.851 d(n _x -n _y )=281.5nm The first compensation film Φ=29.72 degrees Nz=0.3984 d(n _x -n _y )=272nm Second compensation film Φ=-29.72 degrees Nz=0.3984 d(n _x -n _y )=272nm The fourth compensation film Φ=-25.75 degrees Nz=0.851 d(n _x -n _y )=281.5nm upper polarizer Φ=-30 degrees

third embodiment

FIG. 33 is a schematic cross-sectional view of a display device according to a third embodiment of the present invention. Please refer to FIG. 33 , the display device 100c of this embodiment is similar to the display device 100b of the second embodiment, the difference is that in the display device 100c, the third compensation film 31b is located on the first compensation film 28b and the first substrate 21b, the fourth compensation film 31a is located between the second compensation film 28a and the second substrate 21a.

According to this embodiment, the third compensation film 31b and the fourth compensation film 31a are, for example, biaxial compensation films respectively. The third compensation film 31b and the fourth compensation film 31a can be designed according to different positioning angles Φ, so as to compensate for the angle difference between the upper polarizer 23a and the lower polarizer 23b. According to this embodiment, the directional light 282 passes through the lower polarizer 23b, the first compensation film 28b, the third compensation film 31b, the fourth compensation film 31a, the second compensation film 28a and the upper polarizer 23a in sequence.

34 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a third embodiment of the present invention. Referring to FIG. 34 , in this embodiment, the first compensation film 28 b rotates the polarization state from the P ₁ state to the P ₀ state. Next, the third compensation film 31b rotates the polarization state from the P ₀ state of the linear polarization state to the C ₁ state of the circular polarization state. Afterwards, the fourth compensation film 31a rotates the polarization state from the C ₁ state of the circular polarization to the P ₀ state of the linear polarization state. Afterwards, the second compensation film 28a rotates the polarization state from the P ₀ state to the A ₁ state conforming to the absorption axis of the upper polarizer 23a. Since the circularly polarized light is not affected by the orientation angle of the blue phase liquid crystal material, the circularly polarized light can improve the viewing angle of the VFS blue phase liquid crystal display.

Table 8 is the parameter setting data of each component in the display device 100c. FIG. 35 is a contour map of the contrast ratio measured by the display device in FIG. 33 according to the parameter settings in Table 8. FIG.

table eight

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=45 degrees The first compensation film Φ=40 degrees Nz=0.575 d(n _x -n _y )=256nm The third compensation film Φ=90 degrees Nz=0.5 d(n _x -n _y )=137nm The fourth compensation film Φ=0 degree Nz=0.5 d(n _x -n _y )=137nm Second compensation film Φ=-40 degrees Nz=0.575 d(n _x -n _y )=256nm upper polarizer Φ=-45 degrees

Table 9 is the parameter setting data of each component in the display device 100c. FIG. 36 is a contour map of the contrast ratio measured by the display device in FIG. 33 according to the parameter settings in Table 9. FIG. 36 shows the contours of the optimized contrast ratio for a directional ray 281 with a polarization angle Ψ of 60 degrees and an orientation angle Φ of 270 degrees.

Table nine

incident light Ψ=60 degrees Φ=270 degrees λ=550nm lower polarizer Φ=45 degrees The first compensation film Φ=42 degrees Nz=0.63 d(n _x -n _y )=260nm The third compensation film Φ=90 degrees Nz=0.5 d(n _x -n _y )=137nm The fourth compensation film Φ=0 degree Nz=0.5 d(n _x -n _y )=137nm Second compensation film Φ=-42 degrees Nz=0.63 d(n _x -n _y )=260nm upper polarizer Φ=-45 degrees

Fourth embodiment

FIG. 37 is a schematic cross-sectional view of a display device according to a fourth embodiment of the present invention. Please refer to FIG. 37 , the display device 100d of the present embodiment is similar to the display device 100b of the second embodiment, the difference is that in the display device 100d, the lower polarizer 23b is, for example, a wire-grid polarizer polarizers.

In this embodiment, the first compensation film 28b, the second compensation film 28a, the third compensation film 31b and the fourth compensation film 31a are all disposed between the upper polarizer 23a and the lower polarizer 23b in the form of a silk screen. According to this embodiment, the directional light 282 will sequentially pass through the lower polarizer 23b in the form of silk mesh, the third compensation film 31b, the first compensation film 28b, the second compensation film 28a, the fourth compensation film 31a and the upper polarizer 23a .

38 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a fourth embodiment of the present invention. Please refer to FIG. 38 , in this embodiment, the positioning angle Φ of the absorption axis of the lower polarizer 23 b in the form of screen is 90 degrees, and the positioning angle Φ of the absorption axis of the upper polarizer 23 a is 0 degrees. After the directional light 282 passes through the lower polarizer 23b in the form of a screen, the directional light 282 will be rotated from the P ₁ state to the linearly polarized P ₀ state.

The third compensation film 31b does not change the polarization state when the orientation angle Φ is 270 degrees. The first compensation film 28b rotates the linear light from the P0 state to the _C1 state of the circularly polarized light. The second compensation film 28a rotates the circularly polarized light from the C ₁ state to the A ₀ state conforming to the absorption axis of the upper polarizer 23a. Therefore, excellent dark state performance can be obtained.

However, when the orientation angle Φ of the directional light 282 is different (for example, 300 degrees), the polarization state P ₁ deviates from the P ₀ state. is from 225 degrees to 315 degrees) to rotate the P ₁ state back to the P ₀ state. Next, the first compensation film 28b and the second compensation film 28a rotate the polarization state from the P ₀ state to the P ₂ state via the C ₁ state. Afterwards, the fourth compensation film 31a shifts the linearly polarized light from the _P2 state to the _A1 state conforming to the absorption axis of the upper polarizer 23a, and no light leakage occurs.

Table 10 is the parameter setting data of each component in the display device 100d. FIG. 39 is a contour map of the contrast ratio measured by the display device in FIG. 37 according to the parameter settings in Table 10. FIG. 39 shows the contours of the optimized contrast ratio for a directional ray 281 with a polarization angle Ψ of 70 degrees and an orientation angle Φ of 270 degrees.

table ten

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=90 degrees The third compensation film Φ=90 degrees Nz=0.81 d(n _x -n _y )=317.35nm The first compensation film Φ=45 degrees Nz=0.5 d(n _x -n _y )=137nm Second compensation film Φ=-45 degrees Nz=0.5 d(n _x -n _y )=137nm The fourth compensation film Φ=0 degree Nz=0.81 d(n _x -n _y )=317.35nm upper polarizer Φ=0 degree

Since the lower polarizer 23b in the form of a screen has a very good extinction ratio, a high and wide contrast contour can be obtained. In addition, the lower polarizer 23b in the form of silk mesh is not sensitive to the angle of the directional light 281 and has a small dispersion effect. Therefore, the lower polarizer 23b in the form of silk screen is suitable for VFS blue phase liquid crystal display.

fifth embodiment

FIG. 40 is a schematic cross-sectional view of a display device according to a fifth embodiment of the present invention. Please refer to FIG. 40, the display device 100e of this embodiment is similar to the display device 100b of the second embodiment, the difference is that in the display device 100e, the upper polarizer 23a is located between the guiding optical film 25 and the diffusion film 27 , and the fourth compensation film 31a includes an A-plate compensation film 31a-1 and a C-plate compensation film 31a-2.

In this embodiment, the first compensation film 28b, the second compensation film 28a and the third compensation film 31b are biaxial compensation films. The third compensation film 31b is located between the lower polarizer 23b and the first compensation film 28b, and the first optical film 24b is located between the third compensation film 31b and the first compensation film 28b. In addition, the fourth compensation film 31a is located between the second compensation film 28a and the upper polarizer 23a, and the second optical film 24a is located between the fourth compensation film 31a and the upper polarizer 23a. In more detail, the A-plate compensation film 31a-1 of the fourth compensation film 31a-1 is located between the C-plate compensation film 31a-2 and the second optical film 24a. According to this embodiment, the directional light 282 will sequentially pass through the lower polarizer 23b, the third compensation film 31b, the first optical film 24b, the first compensation film 28b, the second compensation film 28a, the C-plate compensation film 31a-2, The A-plate compensation film 31a-1 and the second optical film 24a. Next, the directional light 282 will form an outgoing light 283 after passing through the guiding optical film 25 and pass through the upper polarizer 23a.

41 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a fifth embodiment of the present invention. Referring to FIG. 41 , in this embodiment, the positioning angles Φ of the lower polarizer 23 b and the upper polarizer 23 a are 0 degrees and 90 degrees, respectively. According to this embodiment, for a directional ray 281 whose incident angle is 70 degrees with a polarization angle Ψ and an orientation angle Φ of 270 degrees, when the directional ray 281 passes through the lower polarizer 23b, the polarization state of the directional ray 281 for the P ₀ state. However, when the orientation angle Φ of the directional light 281 changes (for example, 300 degrees), the polarization state of the directional light 281 will deviate from the P ₀ state to the P ₁ state.

In this embodiment, the third compensation film 31b will not change the polarization state P ₀ state when the orientation angle Φ is 270 degrees, but can shift the polarization state from P ₁ state to P state when the orientation angle Φ is 200 degrees. ₀ state. The first compensation film 28b rotates the linear light from the P ₀ state to the circular light in the C ₁ state. The second compensation film 28 a rotates the circular light from the C ₁ state to the linear light in the P ₀ state. Because the polarization state may change due to the guiding optical film 25 corresponding to the upper polarizer 23a, the C-plate compensation film 31a-2 is designed to rotate the polarization state from the P ₀ state to the P ₂ state, and the A-plate compensation Film 31a-1 is used to rotate the polarization state from the _P2 state to the _A1 state which coincides with the absorption axis of the upper polarizer 23a.

Table 11 is the parameter setting data of each component in the display device 100e, where n _o is the refractive index of the fast axis, _ne is the refractive index of the slow axis, and d is the thickness. FIG. 42 is a contour map of the contrast ratio measured by the display device in FIG. 40 according to the parameter settings in Table 11. Fig. 42 shows the contour lines of the optimized contrast ratio of the directional light 281 with a polarization angle Ψ of 70 degrees and an orientation angle of Φ of 270 degrees, wherein the contour lines from the outer side to the inner side represent the contrast ratios of 100, 200, and 500, respectively. and 1000 contour lines. Figure 43 is a contour map of the bright state measured by the display device in Figure 40 according to the parameter settings in Table 11, wherein the contour lines from the outside to the inside represent the transmittances of 0.2, 0.25, 0.3, 0.35 and 0.4 respectively the contour line.

Table Eleven

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=0 degree The third compensation film Φ=0 degree Nz=0.756 d(n _x -n _y )=254nm The first compensation film Φ=-45 degrees Nz=0.501 d(n _x -n _y )=137.5nm Second compensation film Φ=45 degrees Nz=0.501 d(n _x -n _y )=137.5nm C plate compensation film n _o =1.5095 n _e =1.511 d=48μm Compensation film for plate A Φ=0 degree n _o =1.5095 n _e =1.511 d=70μm upper polarizer Φ=90 degrees

However, the present invention is not limited thereto. Under the framework of using this embodiment, there may be another compensation process, as described below.

44 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a fifth embodiment of the present invention. Referring to FIG. 44 , in this embodiment, the third compensation film 31 b is used to compensate the polarization state from P ₁ state to P ₀ state at different orientation angles. The first compensation film 28b shifts the _P0 state to the _P2 state. The second compensation film shifts the _P2 state back to the _P0 state. The C-plate compensation film 31a-2 will shift the _P0 state to the _P3 state, and the A-plate compensation film 31a-1 will shift the _P3 state to the _A1 state that coincides with the absorption axis of the upper polarizer 23a.

Table 12 is the parameter setting data of each component in the display device 100e. FIG. 45 is a contour map of the contrast ratio measured by the display device in FIG. 40 according to the parameter settings in Table 12. Fig. 45 shows the contour lines of the optimal contrast ratio of the directional light 281 whose polarization angle Ψ is 70 degrees and orientation angle Φ is 270 degrees, wherein the contour lines from the outer side to the inner side respectively represent the contrast ratios of 100, 200, and 500 and 1000 contour lines. Figure 46 is a contour map of the bright state measured by the display device in Figure 40 according to the parameter settings in Table 12, wherein the contour lines from the outside to the inside represent the transmittances of 0.2, 0.25, 0.3, 0.35 and 0.4 respectively the contour line.

Table 12

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=0 degree The third compensation film Φ=0 degree Nz=0.756 d(n _x -n _y )=254nm The first compensation film Φ=112.5 degrees Nz=0.6738 d(n _x -n _y )=275nm Second compensation film Φ=22.5 degrees Nz=0.9328 d(n _x -n _y )=275nm C plate compensation film n _o =1.5095 n _e =1.511 d=65μm Compensation film for plate A Φ=0 degree n _o =1.5095 n _e =1.511 d=70μm upper polarizer Φ=90 degrees

It can be known from FIG. 43 and FIG. 46 that the bright state area in FIG. 43 is larger than that in FIG. 46 . The above result is because in the compensation process of FIG. 41 , in the blue phase liquid crystal material, the polarization state of the directional light 282 is a circularly polarized light. Since circularly polarized light is independent of orientation angle, it helps to improve contrast ratio contours.

Sixth embodiment

FIG. 47 is a schematic cross-sectional view of a display device according to a sixth embodiment of the present invention. Please refer to FIG. 47, the display device 100f of this embodiment is similar to the display device 100e of the fifth embodiment, the difference is that in the display device 100f, the third compensation film 31b is located on the lower polarizer 23b and the first compensation film 28b, and the lower polarizer 23b is located between the first optical film 24b and the third compensation film 31b.

According to this embodiment, the fourth compensation film 31a is located between the second compensation film 28a and the upper polarizer 23a, and the second optical film 24a is located between the fourth compensation film 31a and the upper polarizer 23a. In this embodiment, the first compensation film 28b, the second compensation film 28a and the third compensation film 31b are biaxial compensation films, and the fourth compensation film 31a includes an A-plate compensation film 31a-1 and a C-plate compensation film 31a -2. According to this embodiment, the directional light 282 will sequentially pass through the lower polarizer 23b, the third compensation film 31b, the first compensation film 28b, the second compensation film 28a, the C-plate compensation film 31a-2, the A-plate compensation film 31a- 1 and the second optical film 24a. Next, the directional light 282 will form an outgoing light 283 after passing through the guiding optical film 25 and pass through the upper polarizer 23a.

48 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a sixth embodiment of the present invention. Please refer to FIG. 48. In this embodiment, the polarization angle of the directional light 281 is, for example, 70 degrees, and the orientation angle is, for example, 270 degrees. When the backlight ray passes through the lower polarizer 23b, the polarization state of the directional light 282 is _P0 state. When the orientation angle of the directional light 282 changes, for example, when the orientation angle is 300 degrees, the polarization state of the directional light 282 will deviate from the P ₀ state to the P ₁ state. The third compensation film 31 b does not change the P ₀ state of the polarization state when the orientation angle is 270 degrees, but can shift the polarized light from the P ₁ state back to the P ₀ state when the orientation angle is 300 degrees. The first compensation film 28 b shifts the linearly polarized light in the P ₀ state to the circularly polarized light in the C ₁ state. The second compensation film 28 a shifts the circularly polarized light in the C ₁ state to the P ₀ state. By the depolarization of the guiding optical film 25, the absorption axis of the upper polarizer 23a moves to the _A1 state. Afterwards, the directional light 282 is shifted from the P ₀ state to the P ₂ state by the C-plate compensation film 31a-2, and is shifted from the P ₂ state by the A-plate compensation film 31a-1 to conform to the absorption of the upper polarizer 23a A ₁ state of the axis.

Table 13 is the parameter setting data of each component in the display device 100f. FIG. 49 is a contour map of the contrast ratio measured by the display device in FIG. 47 according to the parameter settings in Table 13. Fig. 49 shows the contour lines of the optimal contrast ratio of the directional light 282 whose polarization angle Ψ is 70 degrees and orientation angle Φ is 270 degrees, wherein the contour lines from the outer side to the inner side represent the contrast ratios of 100, 200, and 500 respectively. and 1000 contour lines. Figure 50 is a contour map of the bright state measured by the display device in Figure 47 according to the parameter settings in Table 13, wherein the contour lines from the outside to the inside represent the transmittances of 0.2, 0.25, 0.3, 0.35 and 0.4 respectively the contour line. Ideally, the maximum transmittance after passing through the lower polarizer 23b and the upper polarizer 23a is 0.5.

Table 13

incident light Ψ=70 degrees Φ=270 degrees λ=550nm lower polarizer Φ=0 degree The third compensation film Φ=0 degree Nz=0.568 d(n _x -n _y )=209.6nm The first compensation film Φ=-45 degrees Nz=0.501 d(n _x -n _y )=137.5nm Second compensation film Φ=45 degrees Nz=0.501 d(n _x -n _y )=137.5nm C plate compensation film n _o =1.5095 n _e =1.511 d=40μm Compensation film for plate A Φ=0 degree n _o =1.5095 n _e =1.511 d=60μm upper polarizer Φ=90 degrees

Seventh embodiment

FIG. 51 is a schematic cross-sectional view of a display device according to a seventh embodiment of the present invention. Please refer to FIG. 51, the display device 100g of the present embodiment is similar to the display device 100a of the first embodiment, the difference is that in the display device 100g, the lower polarizer 23b is, for example, an O-type polarizer ), and the upper polarizer 23a is, for example, an E-type polarizer.

Generally speaking, the absorption axis of the O-type polarizer will be along the orientation angle Φ of 0 degrees. The C-axis (i.e., the transmission axis) of the E-type polarizer will be positioned along the 0-degree angle Φ. Compared with the lower polarizer 23b (O-type polarizer), the upper polarizer 23a (E-type polarizer) transmits extraordinary light (Extraordinary ray) and absorbs ordinary light (Ordinary ray). The upper polarizer 23a (E-type polarizer) attenuates light transmitted in any direction that is not perpendicular to the C-axis. In this embodiment, the first compensation film 28b and the second compensation film 28a are located between the upper polarizer 23a and the lower polarizer 23b.

52 is a schematic diagram of a Poincaré sphere in a compensation process of a display device using a compensation film in a dark state according to a seventh embodiment of the present invention. Referring to FIG. 52 , in this embodiment, the polarization state of the directional light 281 after passing through the lower polarizer 23b is the _P1 state. The first compensation film 28 b shifts the linearly polarized light in the P ₁ state to the circularly polarized light in the C ₁ state. Since the circularly polarized light is not affected by the orientation angle, the circularly polarized light is applied in the display medium 20 to improve contrast performance and bright state. After the directional light 282 passes through the material of the display medium 20, the second compensation film 28a shifts the circularly polarized light in the C ₁ state back to the state A ₁ that conforms to the absorption axis of the upper polarizer 23a, wherein the display medium 20 does not impart voltage and is isotropic.

Table 14 is the parameter setting data of each component in the display device 100g. FIG. 53 is a contour map of the contrast ratio measured by the display device in FIG. 51 according to the parameter settings in Table 14. Fig. 53 shows the contour lines of the optimized contrast ratio of the directional light 281 with the polarization angle Ψ of 70 degrees and the orientation angle Φ of 270 degrees, wherein the contour lines from the outer side to the inner side represent the contrast ratios of 500, 1000, and 2000 respectively. and a contour line of 5000. Figure 54 is a contour map of the bright state measured by the display device in Figure 51 according to the parameter settings in Table 14, wherein the contour lines from the outside to the inside represent the transmittances of 0.1, 0.15, 0.2, 0.25, and 0.3 respectively , 0.35 and 0.4 contour lines.

Table Fourteen

incident light Ψ=70 degrees Φ=270 degrees λ=550nm O type polarizer Φ=0 degree The first compensation film Φ=-45 degrees Nz=0.5 d(n _x -n _y )=137.5nm Second compensation film Φ=45 degrees Nz=0.5 d(n _x -n _y )=137.5nm C-axis of E-type polarizer Φ=0 degree

To sum up, the present invention provides a compensation film between the upper polarizer and the lower polarizer of the display device. The setting of the compensation film can adjust the polarization state of the directional light incident into the display module, so that the polarization state of the directional light conforms to the direction of the absorption axis of the upper polarizer. In this way, the occurrence of light leakage can be reduced to improve the contrast ratio of the display device. In addition, the arrangement of the compensation film can also change the polarization state of the directional light from a linear polarization state to a circular polarization state and transmit it in the display medium. Accordingly, since the circularly polarized light is not affected by the orientation angle, the viewing angle of the display device can be increased.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

Claims (27)

1. a display device is characterized in that, comprising:

One light source module has a directive property light;

One display module is arranged on this light source module top, and this display module comprises:

One first substrate has one first inside surface and one first outside surface;

One second substrate, the subtend that it is positioned at this first substrate has one second inside surface and one second outside surface; And

One display medium; Between this first substrate and this second substrate, wherein this display medium has tropisms such as an optics, and this display medium has an optical anisotropy when receiving an electric field driven; And this directive property light is when getting into this display module; This directive property light is not orthogonal to this first outside surface, and at this directive property light when penetrating this display module, this directive property light is not orthogonal to this second outside surface;

One guiding blooming; Be positioned on this second outside surface of this second substrate of this display module; It has an incidence surface and an exiting surface; This directive property light gets into this guiding blooming and penetrates light from this exiting surface ejaculation to form one from this incidence surface, wherein has an angle between this ejaculation light and this exiting surface;

One first compensate film is positioned on this first outside surface of this first substrate; And

One second compensate film is between this second substrate and this guiding blooming.

2. display device according to claim 1 is characterized in that, also comprises:

One first blooming is arranged on this first outside surface of this first substrate, and this first blooming has a plurality of first optical textures, said first optical texture can make this directive property light in through the time do not produce total reflection in fact; And

One second blooming is arranged on this second outside surface of this second substrate, and wherein this second blooming has a plurality of second optical textures, said second optical texture can make this directive property light in through the time do not produce total reflection in fact.

3. display device according to claim 2 is characterized in that, also comprises:

Once polaroid is positioned on this first outside surface of this first substrate; And

Polaroid on one is positioned on this second outside surface of this second substrate.

4. display device according to claim 3; It is characterized in that; Wherein this time polaroid is between first compensate film and this first blooming; Should go up polaroid between second compensate film and this second blooming, and this second blooming this guiding blooming and should between the polaroid.

5. display device according to claim 4 is characterized in that,

The orientation angle of this first compensate film is 20 degree ~ 50 degree, and Nz is 0.35 ~ 0.75;

The orientation angle of this second compensate film is-20 degree ~-50 degree, and Nz is 0.35 ~ 0.75.

6. display device according to claim 3 is characterized in that, also comprises:

One the 3rd compensate film is between this first compensate film and this time polaroid; And

One the 4th compensate film, this second compensate film and should between the polaroid.

7. display device according to claim 6 is characterized in that, the 3rd compensate film and the 4th compensate film are respectively a biaxiality compensate film.

8. display device according to claim 7 is characterized in that,

The orientation angle of this first compensate film is 20 degree ~ 40 degree, and Nz is 0.25 ~ 0.55;

The orientation angle of this second compensate film is-20 degree～-40 degree, and Nz is 0.25 ~ 0.55;

The orientation angle of the 3rd compensate film is 15 degree ~ 35 degree, and Nz is 0.75 ~ 0.95;

The orientation angle of the 4th compensate film is-15 degree～-35 degree, and Nz is 0.75 ~ 0.95.

9. display device according to claim 6 is characterized in that, this time polaroid is the polaroid of a web form.

10. display device according to claim 9 is characterized in that,

The orientation angle of this first compensate film is 30 degree ~ 60 degree, and Nz is 0.35 ~ 0.65;

The orientation angle of this second compensate film is-30 degree～-60 degree, and Nz is 0.35 ~ 0.65;

The orientation angle of the 3rd compensate film is-10 degree ~ 10 degree, and Nz is 0.71 ~ 0.91;

The orientation angle of the 4th compensate film is 80 degree ~ 100 degree, and Nz is 0.71 ~ 0.91.

11. display device according to claim 3 is characterized in that, also comprises:

One the 3rd compensate film is between this first compensate film and this first substrate; And

One the 4th compensate film is between this second compensate film and this second substrate.

12. display device according to claim 11 is characterized in that, the 3rd compensate film and the 4th compensate film are respectively a biaxiality compensate film.

13. display device according to claim 12 is characterized in that,

The orientation angle of this first compensate film is 25 degree ~ 55 degree, and Nz is 0.45 ~ 0.75;

The orientation angle of this second compensate film is-25 degree～-55 degree, and Nz is 0.47 ~ 0.67;

The orientation angle of the 3rd compensate film is 80 degree ~ 100 degree, and Nz is 0.4 ~ 0.6;

The orientation angle of the 4th compensate film is-10 degree ~ 10 degree, and Nz is 0.4 ~ 0.6.

14. display device according to claim 3 is characterized in that, this first compensate film and this second compensate film are respectively a biaxiality compensate film.

15. display device according to claim 14 is characterized in that, also comprises:

One the 3rd compensate film, between this time polaroid and this first compensate film, and this first blooming is between the 3rd compensate film and this first compensate film; And

One the 4th compensate film, this second compensate film and should between the polaroid, and this second blooming the 4th compensate film and should between the polaroid.

16. display device according to claim 15 is characterized in that, this guiding blooming this second blooming and should between the polaroid.

17. display device according to claim 16 is characterized in that, the 3rd compensate film is a biaxiality compensate film, and the 4th compensate film comprises an A plate compensate film and a C plate compensate film.

18. display device according to claim 17 is characterized in that,

The orientation angle of this first compensate film is degree 100 ~ 125 degree, and Nz is 0.55 ~ 0.8;

The orientation angle of this second compensate film is 10 degree ~ 35 degree, and Nz is 0.8 ~ 1.0;

The orientation angle of the 3rd compensate film is-10 degree ~ 10 degree, and Nz is 0.6 ~ 0.8;

The orientation angle of this A plate compensate film is-10 degree ~ 10 degree, n _oBe 1.4 ~ 1.6, n _eBe 1.4 ~ 1.6;

The n of this C plate compensate film _oBe 1.4 ~ 1.6, n _eBe 1.4 ~ 1.6.

19. display device according to claim 14 is characterized in that, also comprises:

One the 3rd compensate film, between this time polaroid and this first compensate film, and this time polaroid is between this first blooming and the 3rd compensate film; And

One the 4th compensate film, this second compensate film and should between the polaroid, and this second blooming the 4th compensate film and should between the polaroid.

20. display device according to claim 19 is characterized in that, should guiding blooming this second blooming and should between the polaroid.

21. display device according to claim 20 is characterized in that, the 3rd compensate film is a biaxiality compensate film, and the 4th compensate film comprises an A plate compensate film and a C plate compensate film.

22. display device according to claim 21 is characterized in that,

The orientation angle of this first compensate film is degree-35～-55 degree, and Nz is 0.4 ~ 0.6;

The orientation angle of this second compensate film is 35 degree ~ 55 degree, and Nz is 0.4 ~ 0.6;

The orientation angle of the 3rd compensate film is-10 degree ~ 10 degree, and Nz is 0.45 ~ 0.65;

The orientation angle of this A plate compensate film is-10 degree ~ 10 degree, n _oBe 1.4 ~ 1.6, n _eBe 1.4 ~ 1.6;

The n of this C plate compensate film _oBe 1.4 ~ 1.6, n _eBe 1.4 ~ 1.6.

23. display device according to claim 3 is characterized in that, this time polaroid comprises an O type polaroid, and upward polaroid comprises an E type polaroid.

24. display device according to claim 23 is characterized in that,

The orientation angle of this first compensate film is-35 degree～-55 degree, and Nz is 0.4 ~ 0.6;

The orientation angle of this second compensate film is 35 degree ~ 55 degree, and Nz is 0.4 ~ 0.6.

25. display device according to claim 1 is characterized in that, this angle is 60 degree ~ 120 degree.

26. display device according to claim 25 is characterized in that, this angle is 90 degree.

27. display device according to claim 1 is characterized in that, also comprises a diffusion barrier, is positioned on this guiding blooming.

Images