CN1318897C

CN1318897C - Light polarizing plate for increasing angle of LCD downward view correlative value

Info

Publication number: CN1318897C
Application number: CNB2003101157242A
Authority: CN
Inventors: 洪维泽; 李东龙; 吴龙海; 赖大王
Original assignee: LITE PHOTOELECTRIC SCIENCE AND TECHNOLOGY Co Ltd
Current assignee: LITE PHOTOELECTRIC SCIENCE AND TECHNOLOGY Co Ltd
Priority date: 2003-11-28
Filing date: 2003-11-28
Publication date: 2007-05-30
Anticipated expiration: 2023-11-28
Also published as: CN1621910A

Abstract

The present invention relates to a light polarizing plate for increasing an angle of LCD downward view correlative value. The upper and the lower surfaces of a polyvinyl alcohol board (PVA) are respectively pressed and stuck with a triacetate fiber board (TAC), and the surface of the triacetate fiber board (TAC) at the uppermost layer is further stuck with a surface treating layer, which forms the present invention. When the surface treating layer is produced, mixed black dye is coated, and a protecting film layer is produced, which inhibits the phenomenon of light leakage at a dark state and further raises the contrast performance of an angle of downward view.

Description

Improve the Polarizer of LCD downwards angle of visibility correlative value

Technical field

The present invention is Polarizer and the making thereof that improves LCD polarisation contrast properties; refer in particular to when hardened coating film layer (HC layer) or antistatic layer surface-treated layers such as (AS layers) are made; being mixed into black dyes is coated with in the lump; make a protective film; suppressing dark attitude light leakage phenomena, and then make the Polarizer that improves the downwards angle of visibility contrast properties.

Background technology

Have light and see through, cover the Polarizer of function,, belong to the basic important document that constitutes LCD (LCD) with the liquid crystal of turning function with light.The suitable application area of this LCD is also from small-sized machines such as the robot calculator at initial stage and clock and watch, expanded to mobile computer, word processor, the liquid crystal projector, LCD TV, vehicle navigator device and indoor and outdoor with broad range such as instrumentation machines.

And the visual angle is quite different place of LCD.Liquid crystal panel as shown in Figure 1, after the incident light of backlight 7 passes through Polarizer 6, glass-based flaggy 5, phosphide tin compound conductive layer 3, molecular orientation layer 2, liquid crystal layer 1 in regular turn, penetrate at the Polarizer 6 by molecular orientation layer 2, phosphide tin compound conductive layer 3, colored filter 4, glass-based flaggy 5 and last tool surface-treated layer in regular turn, its output light has just possessed specific directivity characteristics, that is to say that great majority have possessed vertical direction from the light that screen penetrates.If watch a complete white picture from a very oblique angle, we may see black or color distortion.This effect is useful in some occasion, but is that we are undesired in the application of major part.Therefore the industry of production LCD has spent a lot of times to attempt to improve the viewing angle characteristic of LCD.

Again, the LCD industry with maximum perspective definition be usually the correlative value visual angle that can reach at least 10: 1 (four direction is arranged usually, on/down/left side/right side).And correlative value is defined as the ratio of bright attitude penetrability (complete white)/dark attitude penetrability (complete black), and big more then this display of correlative value is good more.The problem of contrast can not occur in the cathode ray tube (CRT) display, is easily because present real complete black picture on the cathode ray tube (CRT) display, but is quite very difficult to LCD.By the backlight 7 that cold-cathode tube constituted is to be difficult to do switch motion fast, so backlight 7 is in the state of lighting all the time.In order to obtain black full picture, Liquid Crystal Module must stop the light that is come by backlight 7 fully fully, but on physical characteristics, these assemblies also can't reach such requirement fully, always have some light leaks and take place.

Fig. 2 tests resulting downwards angle of visibility comparison diagram for the hardened coating film layer (HARD COATING is commonly called as the HC layer) that known Polarizer has thickness 6～8 μ m through optics, and Fig. 3 tests resulting downwards angle of visibility comparison diagram for known Polarizer has thickness 6～8 μ m antistatic layer (ANTI-STATIC ELECTRIC is commonly called as the AS layer) through optics, by as can be known graphic, the correlative value of the Polarizer of HC layer is 6.1, the correlative value of the Polarizer of AS layer is 7.0, and as can be known by the outer rim at place, contrast drawing 270 position angles and a bent arc solid line institute region surrounded, this HC layer and AS layer institute region surrounded scope, because of dark attitude light leakage phenomena, so contrast fails to reach more than 10, have influence on the display characteristic of LCD relatively, so its applicability is just undesirable.

Summary of the invention

The present invention is based on the downwards angle of visibility contrast improvement demand of LCD, and exploitation improves the Polarizer of contrast properties.In order to make LCD can improve its downwards angle of visibility correlative value, to suppress dark attitude light leakage phenomena, the present inventor derives its preliminary theoretical foundation by the definition of visual angle correlative value, also that is to say, as long as reduce the numerical value of dark attitude penetrability, just can reach the raising of correlative value, thereby develop the Polarizer of improvement.

And one of research and development according to the present invention; be hardened coating film layer (HC layer) or antistatic layer surface-treated layers such as (AS layers) to be mixed black dyes be coated with in the lump and make a protective film when making; suppressing dark attitude light leakage phenomena, and then make the Polarizer that improves the downwards angle of visibility contrast properties.

Description of drawings

Fig. 1 is the diagrammatic cross-section of a liquid crystal panel;

Fig. 2 is the comparison diagram that Polarizer tested out of a known tool hardened coating film layer;

Fig. 3 is the comparison diagram that Polarizer tested out of a known tool antistatic layer;

Fig. 4 is the diagrammatic cross-section of Polarizer of the present invention;

Fig. 5 is the dyestuff 2RL of chromium metal azoles salt dyestuff and the absorption spectroanalysis figure that dyestuff BL is tested out;

Fig. 6 is the comparison diagram that Polarizer tested out of the present invention's one tool hardened coating film layer;

Fig. 7 is the comparison diagram that Polarizer tested out of the present invention's one tool antistatic layer.

The drawing reference numeral explanation:

Liquid crystal layer 1; Molecular orientation layer 2; Phosphide tin compound conductive layer 3; Colored filter 4; Glass-based flaggy 5; Polarisation version 6; Polyvinyl alcohol (PVA) sheet material 61; Triafol T sheet material 62; Surface-treated layer 63; Backlight 7.

Embodiment

See also shown in Figure 4, the Polarizer 6 of tool surface-treated layer of the present invention is to stick Triafol T sheet material (TAC) 62 by polyvinyl alcohol (PVA) sheet material (PVA) 61 in each pressing of upper and lower surface, and it is made further to stick together a surface-treated layer 63 on the superiors Triafol T sheet material (TAC) 62 surfaces.Right Polarizer 6 is in order to improve the downwards angle of visibility contrast properties, to suppress dark attitude light leakage phenomena, is to mix black dyes to be coated with together and to make protective film when surface-treated layer 63 is made.

This black dyes is the oiliness dyestuff, and this black oiliness dyestuff is the chromium metal azoles salt dyestuff that contains the free acid form, can buy from market, and its trade name is: FILO COLORS-Navizol Black 2RL, NavizolBlack BL.This type of chromium metal azoles salt dyestuff is the chromium metal azoles salt dyestuff that a chromium atom connects 2 functional groups, be example just with dyestuff 2RL and dyestuff BL in this chromium metal azoles salt dyestuff series, the absorption spectroanalysis figure of dyestuff 2RL and dyestuff BL as can be known as shown in Figure 5, this dyestuff 2RL and dyestuff BL all have in the low-down characteristic of 300～700nm visible-range iuuminting degree, possess the effect that extinction is arranged, can be considered and to cover the best medium that suppresses its dark attitude light leakage phenomena light from backlight.

Used hardened coating film material, antistatic film layer material also are respectively described below:

The hardened coating film material comprises: monomer, oligomerization compound (oligomer), light trigger (photo initiator), levelling agent (leveling agent), solvent.

The antistatic film layer material comprises: monomer, oligomerization compound (oligomer), light trigger (photo initiator), levelling agent (leveling agent), ATO and ITO particle, conducting polymer, solvent.

The above hardened coating film material, the included various compositions of antistatic film layer material all are those that such material is used always in the prior art, and this does not give unnecessary details one by one.

The present invention is according to required shading degree, black dyes with proper proportion, chromium metal dye as the free acid kenel, fully be mixed in and contain solvent, as butanone (Methyl Ethyl Ketone, MEK), isopropyl alcohol (IsopropylAlcohol, IPA), in the hardened coating film material or antistatic film layer material masking liquid of toluene (Toluene) or dimethylbenzene (Xylene).Then, with suitable coating method, after coating Polarizer as line rod (wire-bar) coating, patterned roller (micro gravure) or transfer coated (offset coating) etc. with wide viewing angle compensate film, again with the solvent evaporates in the masking liquid, for example use baking box with proper temperature and time heating, or place room temperature to treat its solvent evaporates, afterwards again with UV irradiation sclerosis.

Mat embodiment of the present invention is described as follows in detail, but this is to exemplify, and does not limit to the scope of the invention.

Embodiment 1

Chromium metal azoles salt dyestuff with 0.001%～1% weight ratio mixes the HC laminar surface processing layer that a thickness 6～8 marrows are made in coating with the hardened coating film material, it tests resulting downwards angle of visibility comparison diagram as shown in Figure 6 through optics, and by as can be known graphic, its correlative value is 9.2 (correlative value levels off to 10 very much), and the outer rim at place, contrast drawing 270 position angles and bent arc solid line institute region surrounded change is very little, therefore cause dark attitude light leakage phenomena also significantly to improve, the Polarizer of so making just possesses the phenomenon that suppresses dark attitude light leak is arranged, and can significantly improve the downwards angle of visibility contrast properties, and then strengthen the display characteristic of LCD.

Embodiment 2

Chromium metal azoles salt dyestuff with 0.001%～1% mixes the HC laminar surface processing layer that a thickness 6～8 Kua are made in coating with antistatic layer (AS layer), it tests resulting downwards angle of visibility comparison diagram as shown in Figure 7 through optics, and by as can be known graphic, its correlative value was 10.4 (correlative value surpasses in 10), and the contrast drawing does not find to have the phenomenon of dark attitude light leak, the Polarizer of so making not only suppresses the phenomenon of dark attitude light leak fully, and can significantly improve the downwards angle of visibility contrast properties, and then strengthen the display characteristic of LCD.

By the foregoing description as can be known; the present invention is on hardened coating film layer (HC layer) or antistatic layer surface-treated layers such as (AS layers); the mixing black dyes is coated with in the lump and makes a protective film when making; to possess the characteristic that suppresses dark attitude light leakage phenomena; and then the display characteristic of enhancing LCD, be that an invention that has industry applications is created in fact.

Claims

1, a kind of Polarizer that improves LCD downwards angle of visibility correlative value; it is characterized in that: it is to stick Triafol T sheet material by polyvinyl alcohol (PVA) sheet material in each pressing of upper and lower surface; and it is made further to stick together surface-treated layer on the superiors' Triafol T plate surface, and this surface-treated layer is mixed with the chromium metal azoles salt dyestuff that contains the free acid form and is coated with together and makes protective film when making.

2, the Polarizer of raising LCD downwards angle of visibility correlative value as claimed in claim 1, wherein this chromium metal azoles salt dyestuff that contains the free acid form is to mix coating with the surface treatment layer material with 0.001%～1% weight ratio to make.

3, the Polarizer of raising LCD downwards angle of visibility correlative value as claimed in claim 1, wherein this surface-treated layer is the hardened coating film protective seam.

4, the Polarizer of raising LCD downwards angle of visibility correlative value as claimed in claim 1, wherein this surface-treated layer is the antistatic protection layer.