Patent Application
20150286099
1. Field of the Invention
The present invention relates to the liquid crystal display technical field, and in particular to a compensation architecture of a liquid crystal panel and a liquid crystal display device.
2. The Related Arts
Liquid Crystal Display, LCD, is a thin flat display device, it consists of a number of color or monochrome pixels, which is placed in front of the light source or the reflector. The power consumption of the LCD is less. Otherwise, it also has the feature of the high image quality, small size and light weight. Therefore, it is favored by everyone and becomes the mainstream of display. The current LCD is mainly thin film transistor, TFT, LCD.
Along with the growing area of the TFT-LCD, the view angle increases continuously, the contrast of the screen becomes lower, the picture clarity declines, this is a result of the birefringence of the liquid crystal molecules in the liquid crystal layer changing with the viewing angle varying. For ordinary LCD screen, when watching the ordinary LCD screen, we will find its rapid loss of brightness (darker) and discoloration. The traditional LCD typically has 90 degrees viewing angle, it is namely 45 degrees on the left side and right side. The line liquid crystal used to produce LCD panel is a material having birefringence Δn, when light passes through the liquid crystal molecules, it divides into ordinary ray and extraordinary ray two lights, if the incident light on the liquid crystal molecules is oblique, it will produce two refracted lights, the birefringence Δn=ne−no, ne is the refractive index of the liquid crystal molecules versus the ordinary light, no is refractive index of the liquid crystal molecules versus the very light. Therefore, after the light passing through the liquid crystal clamped by the upper and lower glasses, the light will produce a phase retardation phenomenon. The characteristics of the liquid crystal cell is usually measured by phase retardation Δn×d, also known as the optical path difference, Δn is the birefringence, d is the thickness of the liquid crystal cell, the difference of the phase retardation under the different perspective of the liquid crystal cell is the origin of the viewing angle problems. A good phase retardation of the optical compensation can be offset with the phase retardation of the line liquid crystal, thereby widening the viewing angle of the LCD panel. The principle of the optical compensation film is generally to calibrate the phase difference generated by the liquid crystal in different perspective, symmetrically compensating the birefringence of the liquid crystal molecules. Using the optical compensation film to compensate can effectively reduce the light leakage of the dark screen, and it can greatly improve the contrast of the screen in a certain perspective. The optical compensation film can be distinguished to the phase retardation film simply changing phase, the color compensation film, the expanded perspective film and so on from its functional purpose. The optical compensation film can reduce the amount of the light leakage of LCD in dark state, and it can significantly improve the image contrast, color, and overcome partial gray-scale inversion problem in a certain perspective. Main parameters of measuring the properties of the optical compensation film comprise the inner surface compensation value Ro in the plane direction, the thickness compensation value Rth in the thickness direction, the refractive index N, and the film thickness D, which Satisfies the following relationship:
Ro=(Nx−Ny)×D;
Rth=[(Nx+Ny)/2−Nz]×D;
Wherein, Nx is the refractive index along the slow axis (having a maximum refractive index axis; namely, the vibration direction of light having a slower velocity of propagation) in the film plane, Ny is the refractive index along the fast axis (having a minimum refractive index axis; namely, the vibration direction of light having a fast propagation rate, perpendicular to Nx) in the film plane, Nz is the refractive index in the film plane direction (perpendicular to Nx and Ny).
For the different liquid crystal display mode, which namely is the different liquid crystal cell type, the used optical compensation film is also different; moreover, Ro and Rth also need to adjust to an appropriate value. Most of the optical compensation film used by the existing large-size LCD TV is against VA (Vertical Alignment) mode display, during the early stage it is used by Konica's N-TAC, subsequently evolving and forming to OPTES's Zeonor, Fujitsu's F-TAC Series, Nitto Denko's X-plate and so on.
In the existing compensation method, generally using a single or double biaxial compensation structure, the single biaxial compensation structure only needs to provide a compensation film on the one side of the liquid crystal panel, the double biaxial compensation structure needs to provide a compensation film on both sides of the liquid crystal panel, it can only be compensated by adjusting the compensation value of the biaxial compensation film. Referring to
Consequently, under the existing single-layer or double-layer biaxial compensation structure mode, although using the double-layer biaxial compensation structure to compensate, the perspective of the liquid crystal panel which the dark state light leakage is serious is in the middle of the horizontal and vertical viewing angle, relating to the single-layer biaxial compensation structure has a slight improvement, but the double-layer biaxial compensation structure is more expensive, which is not conducive to reducing costs, and the improvement is limited. Although using the single-layer biaxial compensation structure to compensate can effectively reduce the costs, the dark state light leakage of the liquid crystal closing to the horizontal perspective is serious, low contrast, affecting the viewing experience.
In order to improve the deficiency of the prior art, the present invention provides a compensation architecture of a liquid crystal panel, through setting a reasonable compensation value, it can deflect the angle which the dark state light leakage of the liquid crystal panel is serious from the horizontal viewing angle region to the vertical viewing angle region; moreover, it can effectively reduce the dark state light leakage of the liquid crystal panel and ensure that the light leakage concentrate in the smaller range.
In order to achieve the above purpose, the present invention using the following technical solution:
A compensation architecture of a liquid crystal panel, which comprises a sequentially stacked protective film, a first polarizing film, a biaxial compensation film, a liquid crystal panel, a second protective film, a second polarizing film and a third protective film, wherein the liquid crystal panel is provided a liquid crystal layer including a plurality of liquid crystal molecules, the refractive index anisotropy of the liquid crystal layer is Δn, the thickness is d, the pretilt angle of liquid crystal molecules is θ; the compensation thickness of the biaxial compensation film is Rth1; the compensation thickness of the second protective film is Rth2, wherein:
287.3 nm≦Δn×d≦305.7 nm;
85°≦θ<90°;
180 nm≦Rth1≦260 nm;
Y1 nm≦Rth2≦Y2 nm;
Y1=−0.885×Rth1+241.9;
Y2=−0.006638×(Rth1) 2+1.95×Rth1−6.3
Wherein 290 nm≦Δn×d≦303 nm.
Wherein 200 nm≦Rth1≦240 nm; 59 nm≦Rth2≦88.5 nm.
Wherein the compensation thickness Rth2 of the second protective film is chosen 59 nm.
Wherein the material of the first polarizing film and the second polarizing film is polyvinyl alcohol.
Wherein the materials of the first protective film, the second protective film and the third protective film are cellulose triacetate.
Wherein the angle between the absorption axis of the first polarizing film and the slow axis of the biaxial compensation film is 90°.
Wherein the liquid crystal panel is the vertical alignment.
On the other hand, the present invention provides a liquid crystal display device, which comprises a liquid crystal display panel and a backlight module, the liquid crystal display panel and the backlight module being disposed relatively, the backlight module providing a display light to the liquid crystal display panel in order to make the liquid crystal display panel display the image, wherein the liquid crystal display panel using the liquid crystal panel having the compensation architecture as described above.
Relating to the prior art, in the present invention, through setting a reasonable compensation of the biaxial compensation film and the second protective film, it can deflect the angle which the dark state light leakage of the liquid crystal panel is serious from the horizontal viewing angle region to the vertical viewing angle region; moreover, it can effectively reduce the dark state light leakage of the liquid crystal panel and ensure that the light leakage concentrate in the smaller range. Compensating by combining the single-layer biaxial compensation film and the second protection film can not only solve the issue of using the single-layer biaxial compensation film, but also reduce the costs of the double-layer biaxial compensation film compensation.
a is a profile distribution of the dark full viewing angle isoluminant of the liquid crystal panel after the conventional single-layer biaxial compensation structure compensating.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
a is a profile distribution of the dark full viewing angle isoluminant of the liquid crystal panel after the conventional double-layer biaxial compensation structure compensating.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
a is a profile distribution of the dark full viewing angle isoluminant of a compensated liquid crystal panel in an embodiment.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
a is another profile distribution of the dark full viewing angle isoluminant of a compensated liquid crystal panel in an embodiment.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
a is a profile distribution of the dark full viewing angle isoluminant of a compensated liquid crystal panel in an embodiment.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
a is the other profile distribution of the dark full viewing angle isoluminant of a compensated liquid crystal panel in an embodiment.
b is a profile distribution of the full viewing angle contrast of the liquid crystal panel shown in
In order to make the purposes, technical solutions and advantages of the present invention more clearly understood, the following combines the preferred embodiment of the present invention and its accompanying drawings to describe in detail.
As shown in
Specifically, aforementioned compensation architecture is a single-layer biaxial compensation structure, as shown in
In the above architecture, its purpose is to properly provide the compensation value of the biaxial compensation film 13 and the second protective film 15, achieving to the purpose of deflecting the angle which the dark state light leakage of the liquid crystal panel is serious from the horizontal viewing angle region to the vertical viewing angle region.
In the simulation process, the settings is shown below:
First, setting liquid crystal layer:
1. The pretilt angle θ is 85°≦θ≦90°;
2. The liquid crystal tilt angles of the four quadrants are respectively 45°, 135°, 225° and 315°;
3. The optical path difference Δn×d is 287.3 nm≦Δn×d≦305.7 nm.
Second, setting backlight source:
1. Source: Blue-YAG LED spectrum;
2. Central light source luminance is defined as 100 nit;
3. The light distribution is Lambert's distribution.
Referring to
Y1=−0.885×Rth1+241.9;
Y2=−0.006638×(Rth1) 2+1.95×Rth1−6.3.
Since the compensation value Ro, Rth, the refractive index N and the thickness D of the compensation film have the following relationship:
Ro=(Nx−Ny)×D;
Rth=[(Nx+Ny)/2−Nz]×D;
Therefore, changing the compensation value through the following three methods:
1. On the basis of the refractive index N of the existing biaxial compensation film 13 and the second protective film 15 the same, changing the thickness D to vary the compensation value;
2. On the basis of the refractive thickness D of the existing biaxial compensation film 13 and the second protective film 15 the same, changing the refractive index N to vary the compensation value;
3. On the basis of ensuring the range of the thickness compensation value Rth of the biaxial compensation film 13 and the second protective film 15, simultaneously varying the thickness D and refractive index N to change the compensation value.
The following chooses a specific compensation value and tests the corresponding compensation results, further specific describing the technical effects obtained by the technical solution of the present invention.
Referring to
Referring to
Referring to
Referring to
The specific value of the optical path difference Δn×d, the pretilt angle θ, Rth1 and TAC Rth2 provided by the above embodiments is only described as an example. According to the proving results, it can achieve the technical effect of the same or similar with the above-mentioned specific examples when the values of these parameters are within the following ranges: 287.3 nm≦Δn×d≦305.7 nm; 85°≦θ<90°; 180 nm≦Rth1≦260 nm; Y1 nm≦Rth2≦Y2 nm; Y1=−0.885×Rth1+241.9; Y2=−0.006638×(Rth1) 2.+1.95×Rth1−6.3 180 nm≦Rth1≦260 nm; Y1 nm≦Rth2≦Y2 nm; where, Y1=−0.885×Rth1+241.9; Y2=−0.006638×(Rth1) 2+1.95×Rth1−6.3. Particularly, when the compensation thickness Rth1 of the biaxially compensation film 13 is 200˜240 nm, the compensation thickness Rth2 of the second protective film is in the range of 59˜88.5 nm, the solution can obtain the better technical effect.
In conclusion, in the present invention, through setting a reasonable compensation value of the biaxially compensation film and the second protective film, it can deflect the angle which the dark state light leakage of the liquid crystal panel is serious from the horizontal viewing angle region to the vertical viewing angle region; moreover, it can effectively reduce the dark state light leakage of the liquid crystal panel and ensure that the light leakage concentrate in the smaller range. Compensating by combining the single-layer biaxial compensation film and the second protection film can not only solve the issue of using the single-layer biaxial compensation film, but also reduce the costs of the double-layer biaxial compensation film compensation.
It needs to notice that, in this article, the relational terms such as first and second is only used to distinguish one entity or operating another entity or an operation, it is not necessary to require or imply that there exists any such relationship or sequence between the entity and operation. Besides, the terms “comprise,” “include,” or any other variation are intended to cover a non-exclusive inclusion, thereby making that comprising a series of process, method, materials or apparatus of element not only comprise those elements, but also comprise other elements not expressly listed, or also comprise such inherent elements of process, method, materials or apparatus. In the absence of more restrictive conditions, limiting the elements by the statement “comprises a . . . ”, it doesn't exclude that it also exists other identical elements in comprising the process, method, materials or apparatus of element.
The above description is only the specific embodiment in the present invention, be noted that, for those ordinary technical personnel in this art, it also can be improved and modified under the circumstance of without disobeying the present application principle, these improvements and modifications are also considered in the scope of the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410136880.5 | Apr 2014 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2014/075150 | 4/11/2014 | WO | 00 |
