The liquid crystal indicator of multi-domain vertical orientation mode
Technical field
The present invention relates to a kind of liquid crystal indicator, particularly relate to a kind of liquid crystal indicator that can improve the multi-domain vertical orientation mode of aberration.
Background technology
(liquid crystal display is a kind of flat-panel screens that is widely used LCD) to LCD, has low-power consumption, features such as thin external form, light weight and low driving voltage.Display panels generally comprises infrabasal plate, upper substrate and is filled in liquid crystal layer between the upper and lower base plate; Viewing area on the infrabasal plate comprises a plurality of subpixel area, is provided with thin film transistor (TFT) (TFT) and pixel electrode in it, and thin film transistor (TFT) serves as on-off element; Be formed with common electrode (except the IPS liquid crystal display pattern) on the upper substrate, be formed with alignment film on the electrode of upper and lower base plate, it is vertical orientated that liquid crystal molecule is obtained.Form electric field between the pixel electrode of infrabasal plate and the common electrode of upper substrate, the variation of electric field intensity can be modulated the ordered state of liquid crystal molecule, thereby makes backlight realize the variation of transmitance, forms pattern displaying.
The liquid crystal display pattern that is applied to the TV aspect at present is mainly MVA (Multi-domainVertical Alignment; Multi-domain vertical alignment) pattern.The MVA liquid crystal display mostly is and utilizes protrusion or gap electrode to form the vertical display mode of multidomain, the MVA that all has protrusion with upper and lower base plate is an example, under the situation that does not have electric field to exist, liquid crystal is vertical orientated under the effect of alignment film, shown in Figure 1A, this moment, display had good black attitude.Liquid crystal molecule is applied certain voltage, and liquid crystal is turned to gradually by the homeotropic alignment state and is arranged in parallel, and shown in Figure 1B, the display transmitance changes, thereby realizes that image shows.In this process,, promptly form the multidomain display mode owing to the dip plane of protrusion or because the tilting electric field that strip shaped electric poles forms triggers the orientation that liquid crystal molecule forms a plurality of directions.In this case, the observer is the shown picture of view screen under each visual angle, and observed GTG unanimity does not have the generation of phenomenons such as gray-scale inversion, has shown good viewing angle characteristic, as shown in Figure 2.
Though the MVA display mode does not have the gray-scale inversion phenomenon to take place, it still has the direction interdependence in the performance of color.Change as can be seen from the light intensity that sees through LCD,
In this formula, I is a transmitted light intensity, I
0Be incident intensity, λ is a lambda1-wavelength, and d is the thickness of liquid crystal cell, and Φ is the position angle of liquid crystal molecule.Effective refractive index wherein
N here
0, n
e, θ is respectively the polar angle of ordinary refractive index, extraordinary refractive index and the liquid crystal molecule of liquid crystal molecule.n
0, n
e, θ and Φ definition as shown in Figure 3.
In liquid crystal display, the effective refractive index of liquid crystal molecule is relevant with the polar angle of liquid crystal molecule, and under different visual angles, the effective refractive index of liquid crystal molecule performance is inequality, then can cause the variation of transmitted light intensity.The concrete ability drop that sees through that shows as the angle of squint under, the color that angle of squint direction and positive view directions are showed is inconsistent, the generation aberration, thus influence angular field of view and image quality.When showing as colors (as orange, pink etc.) such as Asian's colours of skin, flaws such as inclined to one side indigo plant or whiting can appear in the angle of squint direction.
For solving the aberration problem of angle of squint direction, utilize capacity coupled method or double T FT method of driving to form the above display mode in 8 farmlands, liquid crystal molecule is reached unanimity at the effective refractive index of each view directions performance, transmitance difference under the different visual angles is diminished, thereby the aberration of angle of squint direction is improved.
Utilize capacitive coupling at present, form the pattern that 8 farmlands show, mostly be the common storage line (Common line) that utilizes infrabasal plate or utilize gate metal shading line to form in the infrabasal plate exposure.If the width of the design width of Common line or shading line and grid cabling design difference is bigger, then in developing procedure, be not easy control than the wide cut of lametta, form like this may produce behind the liquid crystal display show bad.In addition,, then can reduce aperture opening ratio, reduce transmitance if it is wide to be used to form the metal wire design of coupling capacitance.
Summary of the invention
The technical matters that the present invention solves is to provide a kind of and need not to utilize that metal wire forms the liquid crystal indicator that coupling capacitance just can be improved the multi-domain vertical orientation mode of liquid crystal display aberration, raising display quality on the infrabasal plate.
Based on above-mentioned purpose, the invention provides a kind of liquid crystal indicator of multi-domain vertical orientation mode, comprise a upper substrate, an infrabasal plate and be filled in liquid crystal layer between the upper and lower base plate; Be formed with the metal black matrix on the described upper substrate, upper substrate surface is formed with common electrode, is formed with first slit or projection on the common electrode; The viewing area of described infrabasal plate includes a plurality of subpixel area, is provided with pixel electrode in the sub-pixel, is formed with slit or projection on the pixel electrode; Also be formed with second slit on the wherein said common electrode, the common electrode relative with the pixel electrode zone is divided at least two discrete areas, discrete areas overlaps with the metal black matrix layer respectively.
Based on above-mentioned design, the liquid crystal indicator of multi-domain vertical orientation mode of the present invention, common electrode on each sub-pixel upper substrate is divided into two or more separate areas with certain area ratio, these discrete areas respectively with upper substrate on the metal black matrix layer overlapping of a certain size area is arranged, when at least one separate areas is applied in voltage in a plurality of zones on the above-mentioned common electrode, other zone then utilizes the metal black matrix layer, make the coupling capacitance effect takes place between the discrete areas, thereby making sub-pixel form a plurality of zones shows, because coupling capacitance effect, each regional electric field difference of sub-pixel, the orientation performance of liquid crystal molecule is different, therefore form multidomain and show, thereby improve aberration.
In order to illustrate further feature of the present invention and technology contents, see also following about detailed description of the present invention and accompanying drawing.Wherein the only for reference and aid illustration usefulness of accompanying drawing is not construed as limiting the invention.
Description of drawings
Figure 1A is the liquid crystal molecular orientation synoptic diagram of MVA pattern when not applying electric field;
Figure 1B is the liquid crystal molecular orientation synoptic diagram of MVA pattern when applying electric field;
Fig. 2 is the display frame of observing the MVA pattern under different visual angles;
Fig. 3 A is the synoptic diagram of liquid crystal molecule state definition;
Fig. 3 B is the synoptic diagram of liquid crystal molecule refractive index definition;
Fig. 4 A is the structural representation of first embodiment of the invention upper substrate common electrode;
Fig. 4 B is the structural representation of first embodiment of the invention pixel electrode;
Fig. 5 is the schematic top plan view of first embodiment of the invention sub-pixel structure;
Fig. 6 is a second embodiment of the invention upper substrate common electrode structural representation;
Fig. 7 is a third embodiment of the invention upper substrate common electrode structural representation;
Fig. 8 A is the interior form synoptic diagram of liquid crystal molecule under electric field driven of a separate areas in the first embodiment of the invention;
Fig. 8 B is the interior form synoptic diagram of liquid crystal molecule under electric field driven of another separate areas in the first embodiment of the invention;
Fig. 9 A~9D is the 4 farmland displayed map of first embodiment of the invention under different voltages;
Figure 10 A~10D is the 8 farmland displayed map of first embodiment of the invention under different voltages;
Figure 11 be first embodiment of the invention under different voltages transmitance with the variation relation figure of view angle theta;
Figure 12 A is first embodiment of the invention positive visual angle and angle of squint 60 under the 4 farmland display modes V-T curve map when spending;
Figure 12 B is first embodiment of the invention positive visual angle and angle of squint 60 under the 8 farmland display modes V-T curve map when spending.
Among the figure:
10. upper substrate 11. projectioies (or first slit) 12. common electrodes
13. second slit, 14. metal black matrixes, 15,16,17. discrete areas
20. infrabasal plate 21. projectioies (or slit) 22. pixel electrodes
30. liquid crystal layer 31. liquid crystal molecules
Embodiment
The invention will be further described below in conjunction with accompanying drawing and exemplary embodiments.
Figure 1A is the liquid crystal molecular orientation synoptic diagram of MVA pattern when not applying electric field; Figure 1B is the liquid crystal molecular orientation synoptic diagram of MVA pattern when applying electric field; Fig. 4 A is the common electrode structural representation of first embodiment of the invention upper substrate; Fig. 4 B is the pixel electrode structural representation of first embodiment of the invention.
With reference to Figure 1A, 1B, the liquid crystal indicator of multi-domain vertical orientation mode of the present invention comprises a upper substrate 10, an infrabasal plate 20 and is filled in liquid crystal layer 30 between upper and lower base plate 10 and 20; Simultaneously with reference to Fig. 4 B, have many cross one another sweep traces and signal wire on the infrabasal plate 20 to define subpixel area, be provided with pixel electrode 22 and TFT device (not illustrating among the figure) in the sub-pixel, the TFT device serves as on-off element, is formed with slit or projection 21 on the pixel electrode 22; Be formed with on the upper substrate 10 and be used to stop light to enter the interior metal black matrix (BM) 14 of non-pixel region, black matrix 14 defines a plurality of subpixel area, in order to cut apart the chromatic filter layer that continues and make, to increase color contrast, be formed with red (R), green (G), blue (B) three kinds of chromatic filter layers (not illustrating among the figure) in the sub-pixel, be formed with common electrode 12 on black matrix 14 and the chromatograph, be formed with first slit or projection 11 on the common electrode 12; With reference to Fig. 5, slit that forms on the described pixel electrode 22 or projection 21, relative with first slit or projection 11 dislocation on the common electrode 12.
Liquid crystal layer 30 is made of for negative and anisotropic liquid crystal material specific inductive capacity, and pixel electrode 22 and common electrode 12 all adopt transparent conductive material to make, as ITO (tin indium oxide), IZ0 (zinc-tin oxide) etc.; Metal black matrix 14 is made by crome metal (Cr) usually, in order to reduce surface reflection, also available chromium oxide (CrOx) is made, in addition, the liquid crystal indicator of multi-domain vertical orientation mode also comprises the VA type alignment film that is arranged on upper and lower substrate 10 and 20 inboards, is arranged on (all not the showing among the figure) such as Polarizers in the substrate 10 and 20 outsides.
With reference to Fig. 4 A, Fig. 5, described second slit 13 is divided at least two zones with the common electrode 12 relative with subpixel area, and discrete areas and metal black matrix 14 have overlapping to a certain degree.Shown in Fig. 4 A, second slit 13 is "<" shape, common electrode 12 on the upper substrate 10 of a sub-pixel is divided into two zones 15,16 that area is different, these two zones are discrete areas, when one of them zone is applied common electric voltage, another zone then utilizes metal black matrix 14 to form coupling effect, have the different driving electric field and realize that multidomain shows with the liquid crystal molecule 31 that causes zones of different, and display effect can be optimized.
The common electrode structural representation of upper substrate 10 as shown in Figure 6 in second embodiment of liquid crystal indicator of the present invention, be with the difference of liquid crystal indicator first embodiment of the present invention, second slit 13 is strip, the common electrode on the upper substrate 10 12 is divided into two zones 15,16 of rectangular shape.
The common electrode structural representation of the 3rd embodiment upper substrate 10 of liquid crystal indicator of the present invention as shown in Figure 7, be with the difference of first, second embodiment of liquid crystal indicator of the present invention, two second slits 13 that are strip with the common electrode on the upper substrate 10 12 discrete be three zones 15,16,17.
The shape of liquid crystal indicator common electrode discrete areas of the present invention is not limited to the described shape of above embodiment.
The number in the discrete common electrode of liquid crystal indicator of the present invention zone is not limited to the described number of above embodiment.
Improvement place for the liquid crystal indicator of 4 farmland vertical alignment modes of the liquid crystal display pattern of better explanation multi-domain vertical orientation mode of the present invention and prior art, the first embodiment of the invention example utilizes the LCD simulation softward to make the demonstration of 4 farmlands respectively, and the 8 farmlands demonstration of using structure of the present invention, its V-T curve under different visual angles is compared.Concrete simulation process is as follows:
The sub-pixel structure that adopts software simulation as shown in Figure 5, in Fig. 5, the IT0 common electrode 12 of upper substrate 10 sides is by two zones of second slit, 13 discrete one-tenth 15,16.If adopt liquid crystal indicator of the present invention to show to form 4 farmlands, then on two zones 15,16, all apply common electric voltage, if adopt liquid crystal indicator of the present invention to show to form 8 farmlands, then zone 16 is applied common electric voltage, zone 15 is not applied common electric voltage, zone 15 utilizes metal black matrix 14 to form coupling effect, can realize that 8 farmlands show.
Because the IT0 common electrode 12 on the upper substrate 10 is divided into two zones 15,16, under 4 above-mentioned farmland display modes, performance was identical when the liquid crystal molecule in two zones 15,16 was subjected to electric field driven.Under 8 above-mentioned farmland display modes, the liquid crystal molecule in two zones 15,16 is subjected to the electric field driven difference, and the electric field action that the liquid crystal molecule in zone 16 is subjected to is higher, and then liquid crystal molecule 31 more tends to the arrangement of parallel substrate direction; And zone 15 voltage is to be coupled to form by metal black matrix 14, the electric field of its formation a little less than, the degree that liquid crystal molecule trend parallel substrate direction is arranged forms 8 farmlands and shows not as zone 16.The signal of liquid crystal molecule state as shown in Figure 6.
Utilize software simulation, under different voltages, drive, obtain 4 farmlands and 8 farmland display result shown in Fig. 9 A~9D, Figure 10 A~10D.From Fig. 9, as can be seen, Figure 10 has formed the multidomain demonstration in 10 the contrast, and under identical driven, the transmitance of zone 15,16 performances is different, and the ordered state that liquid crystal molecule is described is inequality.
Figure 11 has provided under 4.0V and the 4.5V voltage transmitance with the variation synoptic diagram of view angle theta, Figure 10 has provided the demonstration of 4 farmlands and 8 farmlands show, transmitance was with the curve of change in voltage when positive visual angle and angle of squint 60 were spent, as can be seen from Figure 9,8 farmlands of liquid crystal indicator of the present invention are compared with 4 farmlands, when visual angle≤60 were spent, the transmitance differences that 8 farmlands are presented within positive visual angle and≤60 degree visual angles were less.
As can be seen from Figure 12,8 farmlands under the structure of the present invention show that angle of squint 60 degree are littler than the difference on 4 farmlands with the difference of facing the visual angle.Reducing of the transmitance of angle of squint direction and positive view directions transmitance difference then can be improved aberration, improves image quality.