阅读说明：本技术 一种改善tn型tft-lcd显示器不稳定亮点异常的方法 (Method for improving unstable bright spot abnormality of TN type TFT-LCD display ) 是由 司斌 齐迪 于 2021-08-12 设计创作，主要内容包括：本发明涉及一种改善TN型TFT-LCD显示器不稳定亮点异常的方法,该方法为在TN型TFT-LCD显示器的彩膜基板的透明电极层上覆盖聚苯乙烯绝缘层。(The invention relates to a method for improving the unstable bright spot abnormality of a TN (twisted nematic) type TFT-LCD (thin film transistor-liquid crystal display), which is to cover a polystyrene insulating layer on a transparent electrode layer of a color film substrate of the TN type TFT-LCD.)

1. A method for improving the unstable bright spot abnormality of a TN type TFT-LCD display is characterized in that a polystyrene insulating layer covers a transparent electrode layer of a color film substrate of the TN type TFT-LCD display.

2. The method of claim 1, wherein the transparent electrode layer is an ITO thin film.

3. The method according to claim 1, wherein the step of preparing the polystyrene insulation layer comprises: and coating a black polystyrene material on the transparent electrode layer of the color film substrate, wherein the polystyrene material covers the transparent electrode layer, and then forming a spacer positioned in a non-pixel region and the polystyrene insulating layer positioned in a pixel region by using a half-tone mask through a one-time exposure process.

4. The method of claim 3, wherein: the halftone mask comprises a first light transmission area and a second light transmission area, the light transmittance of the second light transmission area is lower than that of the first light transmission area, the spacer is formed by exposing the first light transmission area, and the polystyrene insulating layer is formed by exposing the second light transmission area.

5. The method of claim 4, wherein: the light transmittance of the second light-transmitting area is 5-10% of that of the first light-transmitting area.

Technical Field

The invention relates to the field of liquid crystal displays, in particular to a method for improving unstable bright spot abnormality of a TN (twisted nematic) type TFT-LCD (thin film transistor-liquid crystal display).

Background

A Thin Film Transistor Liquid Crystal Display (TFT-LCD) is a common flat panel Display device, and is widely used. In general, a TFT-LCD display is mainly composed of a Color Filter (CF) substrate and an array substrate sandwiching liquid crystal therebetween, and a circuit of the array substrate controls deflection of the liquid crystal in a cell to selectively transmit light from a backlight source for display operation. When the TFT-LCD is electrified, the liquid crystal in the upper voltage driving box and the lower voltage driving box are distorted and deflected to form a structure which can control the shielding and the permeation of light. The TFT-LCD display production process comprises the steps of respectively manufacturing an array substrate and a color film substrate, then carrying out box pairing on the array substrate and the color film substrate to form a whole display screen, and finally cutting the whole display screen into a plurality of smaller screens.

The color film substrate of the Twisted Nematic (TN) TFT-LCD display comprises a plurality of color resistance blocks distributed in an array, black matrixes distributed among the color resistance blocks and a common electrode layer covering the color resistance blocks and the black matrixes; the array substrate typically includes conductive traces and TFT switches. After a color film substrate and an array substrate of a TN type TFT-LCD display are paired, a black matrix on the color film substrate is arranged opposite to a conductive trace and a TFT switch on the array substrate, and in order to ensure the thickness uniformity of the entire display, a Spacer (PS) is usually further arranged on the color film substrate, and the PS is distributed between the color film substrate and the array substrate and used for supporting the color film substrate and the array substrate. The nematic liquid crystal of the TN type TFT-LCD display forms a 90-degree twisted structure in the box, after applying certain voltage, the liquid crystal molecules are vertically arranged, the twisted structure disappears, after removing the voltage, the liquid crystal molecules are restored to the original twisted arrangement, therefore, the twisted degree of the liquid crystal molecules can be controlled by controlling the magnitude of the applied voltage, thereby controlling the brightness of the transmission screen. The pixel electrode of the TN type TFT-LCD display is designed on the TFT surface, the common electrode is designed on the CF surface, and the outermost layer of the two side film layers is provided with an insulating layer PI, so that a capacitor structure under a vertical electric field is arranged in the box. Under the condition of no external voltage, natural light enters the box from the TFT surface polaroid, is deflected by liquid crystal in the box, and finally is transmitted and emitted from the CF surface polaroid to form normal white; after the external voltage is applied, most of liquid crystals in the box are twisted to form vertical distribution, natural light enters the box from the TFT plane polaroid, but the light cannot be deflected through the liquid crystals after entering the box, and is emitted out through the CF plane polaroid to form a black state.

The technical problems of the existing TN type TFT-LCD display are as follows: after an external voltage is applied, when a particle (particle) exists in the box and conducts the upper electrode and the lower electrode to cause short circuit, the vertical deflection electric field at the position is failed instantly, and the light passing through the position can be transmitted out from the CF-face polarizer when the natural light enters the box from the TFT-face polarizer to form a pixel bright point in a black state. When the TN type TFT-LCD display has such particle, the upper and lower electrodes will not be short-circuited under the condition of no external force pressure, and the bright spot problem will be caused by the short circuit of the upper and lower electrodes in the process of applying external force, and the condition is called as unstable bright spot abnormity. When a TN type TFT-LCD display is produced, as long as particles exist in a box, the risk of unstable bright spot abnormality exists, which is caused by the design structure limitation of the existing TN type TFT-LCD display.

The existing technical scheme for improving the unstable bright spot abnormality of the TN type TFT-LCD display is to manage and control a production line of the TN type TFT-LCD display, so that a particle is prevented from existing in a box after a color film substrate and an array substrate of the TN type TFT-LCD display are paired with the box, but the existing technical scheme has a bottleneck: even if the air cleanliness grade of the production line is improved, a detection link is added on the production line, and the production process is improved, all products on the production line cannot be guaranteed to be in a 0particle state, and as long as particles exist in the products, the risk of unstable bright spot abnormity exists.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a method for improving the unstable bright spot abnormality of a TN type TFT-LCD display. The method can be realized by the existing production process and production line for producing TN type TFT-LCD displays.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for improving unstable bright spot abnormality of a TN-mode TFT-LCD display, the method comprising: on the basis of the structure of a color film substrate of the existing TN type TFT-LCD display, a polystyrene insulating layer (PS insulating layer) is covered on a transparent electrode layer (ITO film layer) of the color film substrate.

The method for improving the unstable bright spot abnormality of the TN type TFT-LCD provided by the invention can reduce the risk that after the TN type TFT-LCD is formed into a box, a particle in the box punctures the PI layer to conduct the TFT surface and the CF surface, thereby achieving the purpose of improving the unstable bright spot abnormality.

The following description will be given with reference to specific examples.

Drawings

The figures further illustrate the invention, but the examples in the figures do not constitute any limitation of the invention.

Fig. 1 is a schematic structural diagram of a CF substrate of a conventional TN type TFT-LCD display.

FIG. 2 is a schematic view showing a part of a conventional TN type TFT-LCD display in which particles are present in a cell in a static state and in a pressed state.

Fig. 3 is a schematic structural diagram of a CF substrate of a TN-mode TFT-LCD display according to an embodiment of the present invention.

FIG. 4 is a schematic view of a TN-type TFT-LCD display according to an embodiment of the present invention, showing a portion of the case where a particle is present in the case in a squeezed state.

Wherein the reference numerals are: 1. a color film substrate; 2. a filter layer; 21. a black matrix; 22. color resistance; 3. an organic protective layer; 4. a transparent electrode layer; 51. a spacer; a PS insulating layer; 6. an array substrate; 7. a transparent conductive film; particle.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be mechanically coupled, directly coupled, or indirectly coupled through intervening agents, both internally and/or in any other manner known to those skilled in the art. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The conventional TN type TFT-LCD display comprises an array substrate 6 and a color film substrate 1, wherein the array substrate 6 and the color film substrate 1 are oppositely arranged. As shown in fig. 1, a color film substrate 1 of a conventional TN type TFT-LCD display includes: a substrate; the filter layer 2 is arranged on the substrate, and the filter layer 2 comprises a black matrix 21 and a color resistor 22; the organic protective layer 3 is arranged on the filter layer 2, and one side, away from the substrate, of the organic protective layer 3 is provided with a relatively flat surface; and a transparent electrode layer 4 disposed on the organic protective layer 3. The color filter substrate 1 is further provided with spacers 51(PS), and the spacers 51 are distributed between the color filter substrate 1 and the array substrate 6 and used for supporting the color filter substrate 1 and the array substrate 6. The outermost layer of the array substrate 6 of the existing TN type TFT-LCD display is provided with a transparent conductive film 7.

In the conventional TN TFT-LCD display, when the current is kept on, as shown in fig. 2(a), the part of the conventional TN TFT-LCD display where the particle8 exists in the case is in a static state, and the particle8 does not short-circuit the upper and lower electrodes; as shown in fig. 2(b), when the part of the conventional TN type TFT-LCD display in which the particle8 is present is pressed, the particle8 contacts with the transparent electrode layer 4 and the transparent conductive film 7, respectively, and the upper and lower electrodes are short-circuited, thereby causing a bright spot problem.

The TN TFT-LCD displays normally white in the non-energized state, and when the TN TFT-LCD displays normally white in the energized state, a Gate (Gate) switch is turned on, and a signal voltage is supplied to a pixel electrode (P-ITO) on the transparent conductive film 7 through a channel to form a deflection electric field between the pixel electrode (P-ITO) and a common electrode (V-ITO) on the transparent electrode layer 4, thereby controlling the liquid crystal deflection. An insulating PI layer (not shown in the figure) is arranged on each of the P-ITO and the V-ITO, the PI layers are mainly used for alignment of liquid crystal molecules, and the thickness of the PI layers is very thin. When the particle8 exists between the P-ITO and the V-ITO, the particle8 does not show abnormity when the TN type TFT-LCD display in the power-on state is in the normal static state; when the TN type TFT-LCD display in the power-on state is in the extrusion state, the extrusion action makes the particle8 puncture the insulating PI layer, the P-ITO and the V-ITO are in short circuit, and a deflection electric field cannot be normally formed between the two electrodes, so that the occurrence of poor bright spots is caused. This is the cause of the formation of the unstable bright spot abnormality.

The embodiment provides a method for improving the unstable bright spot abnormality of a TN type TFT-LCD display, which realizes that the TN type TFT-LCD display does not have the bright spot problem in the pressing process under the condition of keeping the power-on state, and the method is to cover a PS insulating layer 52 (polystyrene insulating layer) on a transparent electrode layer 4 of a color film substrate 1 of the TN type TFT-LCD display.

More specifically, in this embodiment, the PS insulating layer 52 on the color filter substrate 1 is prepared through the following steps:

s1, providing a substrate, and sequentially preparing a filter layer 2, an organic protective layer 3 and a transparent electrode layer 4 on the substrate by adopting the prior art, wherein the transparent electrode layer 4 is formed into a whole ITO film by a physical vapor deposition process and is used for cooperating with a pixel electrode on an array substrate 6 to control liquid crystal molecules in the ITO film;

s2, coating a black polystyrene material on the transparent electrode layer 4 by adopting the prior art, covering the transparent electrode layer 4 with the polystyrene material, then forming a spacer 51 positioned in a non-pixel region and a PS insulating layer 52 positioned in a pixel region by using a half-tone mask through a one-time exposure process, and preparing the color film substrate 1 as shown in FIG. 3.

Specifically, the halftone mask in step S2 includes a first light-transmitting region and a second light-transmitting region, the first light-transmitting region is sufficiently light-transmitting, the second light-transmitting region is relatively low-light-transmitting, under the irradiation of ultraviolet light, the spacer 51 located in the non-pixel region is formed by exposing the first light-transmitting region, the PS insulating layer 52 located in the pixel region is formed by exposing the second light-transmitting region, and the light transmittance of the second light-transmitting region is smaller than that of the first light-transmitting region, so that the height of the PS insulating layer 52 is smaller than that of the spacer 51, the specific principle is that the higher the light transmittance of the mask is, the more completely the black polystyrene material coated on the corresponding region is cured, and through the design of the halftone mask, the polystyrene material of the spacer 51 is completely cured, and the polystyrene material of the PS insulating layer 52 is only partially cured, and through the subsequent processes, the loss portion of the PS insulating layer 52 is removed, so as to form a height difference with the spacer 51, the larger the difference between the light transmittances of the second light-transmitting region and the first light-transmitting region is, the larger the difference between the heights of the PS insulating layer 52 and the spacer 51 is

In this embodiment, the light transmittance of the second light-transmitting region is 5-10% of the light transmittance of the first light-transmitting region.

As shown in FIG. 4, in the process of extruding the position of the particle8 in the box of the TN type TFT-LCD, in order to prevent the particle8 from puncturing the PI layer and communicating the P-ITO and the V-ITO, the PS insulating layer 52 is added on the whole surface on the transparent electrode layer 4 of the color film substrate 1, so that the particle8 can not puncture the PS insulating layer 52 when being extruded, the P-ITO and the V-ITO can not be short-circuited, and the defect of bright spots can be prevented from being improved.

The embodiment provides a method for improving the abnormal unstable bright point of a TN (twisted nematic) TFT-LCD (thin film transistor-liquid crystal display), wherein the PS insulating layer 52 and the spacer 51 are formed on the transparent electrode layer 4 on the color film substrate 1 through a halftone exposure process on the whole surface, and the PS insulating layer 52 can remarkably reduce the risk that after the TN TFT-LCD is formed into a box, a particle8 in the box penetrates through a PI layer to conduct P-ITO and V-ITO, so that the purpose of improving the abnormal unstable bright point is achieved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.