Single polaroid reflective type color liquid crystal display
Technical field
The utility model relates to a kind of reflective type color liquid crystal display, particularly relates to a kind of single polaroid reflective type color liquid crystal display.
Background technology
Traditional reflective STN-LCD or CSTN-LCD adopt two polaroids and the reflection horizon optical system that is clipped in liquid crystal layer wherein and is positioned at polaroid back, the end, if be furnished with chromatic color filter again, just can realize colored the demonstration.In this optical system, because incident light and reflected light all need pass through very long light path in the reflection horizon of two polaroids, liquid crystal layer, chromatic color filter and polaroid back, the end, thereby reflectivity is low, the high reflectance of theory is 33%, and can cause parallax, the existence of parallax can cause excitation poorer.For fear of this parallax, improve reflectivity simultaneously, the reflective display of various patterns is developed, as host and guest's formula reflection liquid crystal display spare of no polaroid, reflective TFT liquid crystal display device, wherein single polaroid reflection-type liquid-crystal display device is especially noticeable.Single polaroid reflection-type liquid-crystal display device simple structure and optical principle be as shown in Figure 1: incident light 8 is by unique polaroid 1, first glass substrate 3, liquid crystal layer 4, colored filter 5, the inboard that has an ITO electrode through double-deck birefringent film 2 (optical compensation films), inboard has second glass substrate 6 of ITO electrode, then by reflection horizon 7 reflexs, the order that the light process is opposite forms reflected light 9 successively by reflecting away with the upper strata.By reducing the end polaroid in two polaroid reflection liquid crystal display spares, reflection horizon under the end polaroid can also be moved on second glass substrate from panel is outside simultaneously, form internal reflection, be that incident light is not via the following boundary reflection of second glass substrate, this mode can further solve problem of parallax experienced, and can significantly improve reflectivity, the high reflectance of theory is 41%.But be to use single polaroid reflective-mode optically can face comparatively complicated phase compensation problem.Behind light process polaroid-quarter wave plate-reflecting plate-quarter wave plate, polarization state has changeed 90 degree just and has been absorbed fully.Generally adopt on polaroid and to attach optical compensation films and reach this purpose, and need to use double-deck birefringent film optical compensation films to realize, but every layer of compensate film has two parameters, add the parameter of polaroid and liquid crystal cell, need the comprehensive display performance that above parameter just can be guaranteed display of adjusting, often be difficult to accomplish that various aspects of performance is all more superior and stable.
Summary of the invention
The technical matters that the utility model solves is to have proposed a kind of single polaroid reflective type color liquid crystal display that has high reflecting brightness and show contrast.
The single polaroid reflective type color liquid crystal display that the utility model proposes, comprise: first transparency carrier, second transparency carrier, liquid crystal layer and reflection horizon, be sealed with liquid crystal layer and constitute the liquid crystal box body between first transparency carrier and second transparency carrier, outer panel face at first transparency carrier is provided with polaroid, and described polaroid has individual layer liquid crystal compensation film near first transparent substrate side.
Preferably, the described second transparency carrier upper edge incident light direction is provided with successively: ITO conducting film, OC cushion, filter membranous layer and black-matrix layer, described reflection horizon is positioned under filter membranous layer and the black-matrix layer.
Preferably, only be provided with the ITO conducting film on described second transparency carrier, described reflection horizon is between the ITO conducting film and second transparency carrier.
Preferably, the distortion angle θ of described liquid crystal compensation film is 170 to 190 degree, the dextrorotation distortion; The optical compensation value of liquid crystal compensation film is 660 to 760nm, and the twist angle φ of described liquid crystal cell is 240 to 250 degree, left-handed distortion; The optical delay amount of liquid crystal cell is 780-860nm; The optical absorption axle of polaroid and X-axis angulation are α, and the preceding twist angle of liquid crystal compensation film and X-axis angulation are β, and the frictional direction of second transparency carrier and X-axis angulation are γ, satisfy: β-α is 20 to 30 degree, and α-γ is 55 to 75 degree.
Preferably, described reflection horizon is a reflective metal film; Described reflective metal film is aluminium film, silver or aluminium neodymium alloy metallic film.
The beneficial effects of the utility model are:
1. adopted individual layer liquid crystal compensation film as optical compensation, therefore optical design is compared with the optical design of single polaroid reflection-type liquid-crystal display device of double-deck optical compensation films greatly and is simplified, optical loss reduces simultaneously, can improve reflected light brightness, and Show Color is more bright-coloured.
2. because the LCD in the utility model adopts individual layer liquid crystal compensation film and single polaroid, make the thickness of display become thinner.
3. the utility model has also been determined the parameter area of each device in the display by test, the display performance of the display of further guaranteeing stable.
Description of drawings
Fig. 1 is existing single polaroid reflective type color liquid crystal display spare displaying principle figure;
Fig. 2 is the utility model list polaroid reflective type color liquid crystal display spare structure principle chart;
Fig. 3 is a liquid crystal cell parameter schematic diagram in the utility model preferred embodiment;
Fig. 4 is an individual layer liquid crystal compensation film parameter schematic diagram in the utility model preferred embodiment;
Fig. 5 is a polaroid parameter schematic diagram in the utility model preferred embodiment.
Embodiment
Also in conjunction with the accompanying drawings the utility model is elaborated below by embodiment.
As shown in Figure 2, reflective metal film is selected in reflection horizon 7 for use, can be aluminium film, silverskin, also can be aluminium neodymium alloy film.And if then be the OC cushion below the ITO conducting film of LCD second transparency carrier, be red, green and blue filter membranous layer and black-matrix layer then, then the reflective metal film among Fig. 27 directly places under the filter membranous layer.If second transparency carrier only contains the ITO conducting film of one deck, and with the OC cushion, redness, green and blue filter membranous layer and black matrix" are placed on first transparency carrier, and then reflective metal film 7 is directly done below the ITO of second transparency carrier conducting film.In above-mentioned two kinds of structures, the effect of reflective metal film is the same, and the light of injecting display interior is reflected away, and realizes colored the demonstration through color filter film.Fig. 3 is the optical Design of liquid crystal cell of the present invention, the optical delay amount Δ nd=780-860nm of this liquid crystal cell, twist angle φ=240-250 degree, left-handed distortion.A among Fig. 3 and b represent the frictional direction of first transparency carrier, the frictional direction of second transparency carrier respectively, and γ represents the frictional direction and the X-axis angulation of second transparency carrier.Fig. 4 is a liquid crystal compensation film 10 of the present invention, directly is attached on first transparency carrier 3 among Fig. 2 the distortion angle θ=170-190 degree of liquid crystal compensation film, dextrorotation distortion.The optical compensation value Δ nd=660-760nm of liquid crystal compensation film.β is the preceding twist angle and the X-axis angulation of liquid crystal compensation film.Fig. 5 is a polaroid 1 of the present utility model, the optical absorption axle of polaroid 1 and X-axis angulation are α, polaroid is close to above the liquid crystal compensation film 10, in order to realize that preferable optics shows that the frictional direction of the optical absorption axle of polaroid 1 and the preceding twist angle of liquid crystal compensation film and second transparency carrier must meet the following conditions:
β-α=20-30 degree
α-γ=55-75 degree
According to this optical design system, prepared the reflection-type liquid-crystal display device of three different parameters by test.
The frictional direction a of liquid crystal cell first transparency carrier becomes 30 with X-axis in the device one, the frictional direction b of second transparency carrier all becomes-30 degree with X-axis, be γ=-30 degree, therefore the distortion angle φ of liquid crystal cell=240 are spent, liquid crystal adopts the 115C-1000/1100 of MERK company, Δ nd=800nm, the chirality agent is S-811, left-handed distortion.The distortion angle θ of liquid crystal compensation film=180 degree, dextrorotation distortion, the optical compensation value Δ nd=660nm of liquid crystal compensation film, preceding twist angle and X-axis angulation β=55 degree.Polaroid adopts common STN polaroid SRWO62 (trade name is by the Sumitomo Chemical manufacturing), the angle [alpha] of optical absorption axle and X-axis=30 degree.
The frictional direction a of liquid crystal cell first transparency carrier becomes 35 with X-axis in the device two, the frictional direction b of second transparency carrier all becomes-35 degree with X-axis, be γ=-35 degree, therefore the distortion angle φ of liquid crystal cell=250 are spent, liquid crystal adopts the 115C-1000/1100 of MERK company, Δ nd=830nm, the chirality agent is S-811, left-handed distortion.The distortion angle θ of liquid crystal compensation film=190 degree, dextrorotation distortion, the optical compensation value Δ nd=730nm of liquid crystal compensation film, preceding twist angle and X-axis angulation β=60 degree.Polaroid adopts common STN polaroid SRWO62 (trade name is by the Sumitomo Chemical manufacturing), the angle [alpha] of optical absorption axle and X-axis=40 degree.
In order to contrast, also prepared the not device within the present invention three of optical parametric design.The frictional direction a of liquid crystal cell first transparency carrier becomes 35 with X-axis in the device three, the frictional direction b of second transparency carrier all becomes-35 degree with X-axis, be γ=-35 degree, therefore the distortion angle φ of liquid crystal cell=250 are spent, liquid crystal adopts the 115C-1000/1100 of MERK company, Δ nd=800nm, the chirality agent is S-811, left-handed distortion.The distortion angle θ of liquid crystal compensation film=180 degree, dextrorotation distortion, the optical compensation value Δ nd=630nm of liquid crystal compensation film, preceding twist angle and X-axis angulation β=55 degree.Polaroid adopts common STN polaroid SRWO62 (trade name is by the Sumitomo Chemical manufacturing), the angle [alpha] of optical absorption axle and X-axis=30 degree.
Following table is the test data of device one, two, three, and method of testing is that incident light becomes-30 degree angles to inject device with the Z axle, the intensity of reflected light of test Z-direction, and contrast is the brightness of white picture and the ratio of black picture.
The sample name |
Liquid crystal cell twist angle (degree) |
Liquid crystal cell offset (nm) |
The twist angle of liquid crystal compensation film (degree) |
The offset of liquid crystal compensation film (nm) |
Liquid crystal compensation film and X-axis angulation β (degree) |
The absorption axes angle [alpha] (degree) of polaroid |
White picture brightness (cd/ cm
2)
|
Black look picture brightness (cd/ cm
2)
|
Reflectivity % |
Contrast |
Device one |
240 |
800 |
180 |
660 |
55 |
30 |
12.25 |
1.62 |
12.2 5 |
7.5 |
Device two |
250 |
830 |
190 |
730 |
60 |
40 |
21.32 |
1.75 |
21.3 2 |
12.1 |
Device three |
250 |
800 |
180 |
630 |
55 |
30 |
6.65 |
1.38 |
6.65 |
4.82 |
The device in this optical design three not as can be seen from the table, its reflection efficiency is very low.
In sum, the present invention has adopted individual layer liquid crystal compensation film as optical compensation, therefore optical design is different from the single polaroid reflection-type liquid-crystal display device and the design of traditional double polaroid catoptrics of double-deck optical compensation films, owing to only adopt one deck optical compensation films, therefore simplified optical design, reduced the loss of light total amount, improved reflecting brightness greatly, improved reflective-mode simultaneously and shown contrast, Show Color is more bright-coloured, and makes the general thickness of display become thinner.