JP2004310040A - Peripheral structure of liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the conventional problem wherein liquid crystal is damaged owing to setting-incomplete sealing. <P>SOLUTION: In at least a partial seal area, an array material is replaced with a transparent material. A seal brought into contact with liquid crystal can, therefore, be completely set with ultraviolet rays without being impeded by a light blocking film nor conductive film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a peripheral structure of a liquid crystal panel.

  Since the liquid crystal has the same optical axis direction as the major axis direction of the molecule and has fluidity, the arrangement of the liquid crystal changes with a slight force. For example, general nematic liquid crystal molecules are easily twisted by an electric field. When light from a backlight module, which is polarized by a polarizing filter (polarizer), passes through a liquid crystal, the polarization direction of the light changes according to the alignment direction of the liquid crystal (molecules). If any of the polarizer, light, and polarization direction is different, the transmittance will be different. Therefore, a liquid crystal display determines the brightness of each pixel by controlling the transmittance of each pixel by applying a voltage to the liquid crystal usually sandwiched between two polarizing filters.

  Furthermore, the three primary colors of light, R (red), G (green), and B (blue), are used to form red, green, and blue dots, and various colors are expressed by combining them. Therefore, a liquid crystal display can display and express a color image, particularly, a color image composed of original colors.

  Since the liquid crystal has fluidity, it is injected and fixed in a cell composed of two glass substrates joined by a sealant. Transistors, electrodes, wires, and the like are provided on a glass substrate in order to form an electric field and control the direction in which liquid crystal molecules are arranged. The polarizing filter is also formed on a glass substrate.

  Conventional liquid crystal injection involves the following process of injecting liquid crystal in a vacuum. That is, first, two glass substrates are bonded with a sheath agent to form a cell. An inlet is formed on a certain side of the cell. The cell is sent to a vacuum chamber. The inlets of the two glass substrates combined with the liquid crystal are closed, and then returned to the atmospheric pressure. Due to the pressure difference between the two glass substrates and the chamber, the liquid crystal enters through the inlet. Then, when the inside is filled, the inlet is sealed. However, this liquid crystal injection process has a problem that the time required for liquid crystal injection is long. The processing time also tends to be longer due to an increase in the size of the liquid crystal panel and a decrease in the cell gap. In the current situation where the size of the liquid crystal display tends to increase, the liquid crystal injection process wastes time cost, and the time cost increases due to the enlargement of the liquid crystal panel.

  Recently, a new technology is a liquid crystal dropping method (One-Drop Fill method). According to this, the liquid crystal injection time can be effectively reduced. In the liquid crystal dropping method, an appropriate liquid crystal material is dropped on the lower glass by controlling the liquid crystal dropping speed with a liquid crystal dropping device before bonding the glass substrates, and the upper glass is covered in a vacuum. The cell process is completed by compressing the seal and ultraviolet curing. When the liquid crystal dropping method is adopted in the liquid crystal injection step, the sealing step can be omitted, the number of steps can be reduced, and the liquid crystal injection process time can be within several hours, so that the time cost can be greatly reduced. The liquid crystal dropping method has such advantages.

  By the way, in the liquid crystal manufacturing process, before the liquid crystal is directly dropped, a glass substrate is combined, a highly adhesive seal is applied to the glass substrate in order to restrict the liquid crystal, and after the glass substrates are combined, the glass substrate is sealed with ultraviolet light. To cure.

  As shown in FIG. 3, the ordinary liquid crystal panel 10 has a color filter (CF) glass substrate 100 and a thin film transistor (TFT) glass substrate 120, and a color filter (not shown) is provided on the color filter glass substrate 100. And a light shielding film (black matrix) 140. A transistor (not shown), a conductive film (metal conducting layer) 200, and the like are provided on the transistor glass substrate 120. Both the light shielding film 140 and the conductive film 200 are opaque materials. Therefore, the ultraviolet light 300 is blocked by both the color filter glass substrate 100 and the transistor glass substrate 120. This may cause a problem of insufficient curing of the seal 160. When the liquid crystal 220 contacts the poorly cured seal 160, a polymer or monomer such as an epoxy resin in the sealing material diffuses and enters the liquid crystal 220, thereby contaminating the liquid crystal 220. As a result, the liquid crystal panel may be damaged due to abnormal control of the liquid crystal 220.

In order to solve the problem of insufficient curing of the seal, a method of irradiating ultraviolet rays obliquely, a method of reflecting ultraviolet rays on a bottom plate, and the like have been proposed. However, these methods add complexity to the curing process and increase the risk of exposing the liquid crystal to ultraviolet light. When the liquid crystal is irradiated with ultraviolet rays, the liquid crystal is deteriorated or deteriorated, causing defects in the alignment, deteriorating the image quality of the liquid crystal display, and in some cases, reducing the voltage holding power, thereby causing a screen flicker.
U.S. Pat.No. 6,654,075

  In the above-described conventional liquid crystal dropping method, ultraviolet rays are blocked due to the structure of a light-shielding film or a conductive film, and there is a possibility that the seal may be insufficiently cured and the liquid crystal irradiated with ultraviolet rays may be deteriorated. As a result, the image quality is significantly deteriorated. According to the method of obliquely irradiating the ultraviolet rays, the problem of insufficient curing of the seal can be solved for the time being. However, since a large amount of ultraviolet rays is applied, the liquid crystal is easily deteriorated greatly.

  Therefore, the present invention selects a transparent material for the conductive film of the transistor glass substrate in the region where the seal in contact with the liquid crystal exists, so that light is not blocked by the opaque conductive film. One object is to irradiate the seal from the side and completely cure it, and to avoid liquid crystal contamination due to poorly cured seals.

  Another object of the present invention is to maintain the quality of the liquid crystal high by reducing the probability that the light for curing cures the seal perpendicular to the glass substrate and irradiate the liquid crystal with the light for curing.

  Still another object of the present invention is to simplify the curing process as compared with the conventional art and relax the required accuracy of the process conditions.

The present invention provides a peripheral structure of a liquid crystal panel. This peripheral structure includes a first glass substrate, a second glass substrate, an insulating layer, and a transparent conductive film. The first glass substrate and the second glass substrate are separated from a surface of the first glass substrate having a light-shielding film by a seal. The surface of the second glass substrate having the transistor is attached to the surface of the second glass substrate, and the insulating layer is formed in a region of the display portion of the liquid crystal panel on the surface of the second glass substrate connected to the seal. The present invention also provides another liquid crystal panel peripheral structure. This peripheral structure includes a first glass substrate, a second glass substrate, an insulating layer, and a transparent conductive film. The first glass substrate and the second glass substrate are separated from a surface of the first glass substrate having a light-shielding film by a seal. The surface having the transistor of the second glass substrate is attached to the surface thereof, the insulating layer is formed in a region from the innermost surface of the surface of the second glass substrate connected to the seal to the periphery of the liquid crystal panel, and the transparent conductive film is insulated. Formed on the layer.

  The solution according to the present invention will be described more specifically as follows.

[First embodiment]
In a liquid crystal panel, a first glass substrate and a second glass substrate are bonded with a seal, and a surface of the first glass substrate having a light-blocking film faces a surface of the second glass substrate having a thin film transistor. An inner surface of a surface connected to the seal is a display portion of the liquid crystal panel, having a first insulating layer and a first transparent conductive film formed on the first insulating layer. Construction.

[Second embodiment]
In the first embodiment, a non-display portion of a liquid crystal panel, wherein an outer surface of a surface of the second glass substrate connected to the seal has a second insulating layer and a second conductive film formed on the second insulating layer. And the second conductive film and the first transparent film are electrically connected so as to overlap the inner surface and the outer surface.

[Third embodiment]
In the second embodiment, the display portion of the liquid crystal panel inside the surface of the second glass substrate connected to the seal has a third insulating layer and a third conductive film formed on the third insulating layer. The third conductive film and the first transparent film are electrically connected to a portion where the inner surface and the display unit of the liquid crystal panel overlap.

[Fourth embodiment]
In a liquid crystal panel in which a first glass substrate and a second glass substrate are bonded with a seal, and a surface of the first glass substrate having a light-shielding film is opposed to a surface of the second glass substrate having a thin film transistor, A region from the innermost surface of the surface connected to the seal to the periphery of the liquid crystal panel is a display portion of the liquid crystal panel, which has an insulating layer and a transparent conductive film formed on the insulating layer; Construction.

  According to the present invention, since light irradiates the seal from the transistor glass substrate side, complete curing of the seal can be obtained. Therefore, the conventional inconvenience of a poorly cured seal contaminating the liquid crystal is effectively eliminated.

  In addition, since the curing light irradiates the seal vertically to the glass substrate to cure the seal, the risk (probability) of the liquid crystal being exposed to the curing light can be reduced, and the quality of the liquid crystal can be maintained and secured at a high level. .

  Further, the hardening process can be simplified as compared with the related art, and the required accuracy of the process conditions can be relaxed.

  Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention can be embodied within a wide range including other forms in addition to the forms described in detail below, and the scope of the present invention is defined only by the claims, and is limited to other forms. Note that this is not the case.

    Parts and the like of different elements are not drawn to scale. In order to clarify the description of the present invention and to facilitate understanding, illustration of parts not directly related to the present invention is omitted, and related parts and the like may be exaggerated in dimension.

  As described above, conventionally, when a liquid crystal panel is cured by a liquid crystal dropping method, ultraviolet light or other curing light is blocked by an opaque structure (for example, a light-shielding film or a conductive film), and the seal tends to be insufficiently cured. . Liquid crystals are contaminated and degraded when in contact with a poorly cured seal. According to the present invention, at least the seal in contact with the liquid crystal can be completely cured, so that the disadvantage of the conventional liquid crystal deterioration can be avoided.

  To this end, the conductive film under the seal that contacts the liquid crystal (that is, the inner seal on the display unit side) needs to be made transparent, and if it is made transparent, it will be irradiated with curing light, so that it will be completely cured. be able to.

  In this way, by forming the material of the conductive film below the seal on the inner side with a transparent material, the seal (which comes into contact with the liquid crystal) can be completely cured, and the inconvenience of contamination and deterioration of the liquid crystal can be avoided.

  FIG. 1 shows a preferred embodiment of the present invention. The liquid crystal panel 10 has a color filter (CF) glass substrate 100 and a thin film transistor (TFT) glass substrate (hereinafter, transistor glass substrate) 120. A color filter and a black matrix 140 are provided on the color filter glass substrate 100. The light shielding film 140 is made of an opaque material. The color filter glass substrate 100 and the transistor glass substrate 120 are joined with a seal 160. The transistor glass substrate 120 includes an insulating layer 180 and conductive films 200, 202, 204, 206, and 208.

  The material of the conductive films 200 and 208 is preferably an aluminum (Al) layer, a multilayer including an aluminum (hereinafter, aluminum) layer, or an aluminum alloy. The material of the other conductive films 202, 204, and 206 is a transparent conductive material, preferably, tin oxide (Indium Tin Oxide). In order to completely cure the inside of the seal 160, the innermost position of the conductive film 206 is closer to the display area (that is, the area of the liquid crystal 220 shown in FIG. 1) than the seal 160.

  The formation position of the conductive film 204 adjacent to the conductive film 206 is preferably the position of the innermost conductive film in the area occupied by the seal 160 as shown in FIG. Therefore, the possibility that the liquid crystal is irradiated with curing light (particularly, ultraviolet light) can be reduced, and the quality of the liquid crystal can be maintained.

  In consideration of the conductivity of the liquid crystal panel and other considerations, the outermost portion of the conductive film 204 (that is, the position close to the edge of the glass substrate) is located in the area where the seal exists as shown in FIG. Can be selected.

  All of the conductive films 200 shown in FIG. 1 can be changed to transparent conductive films 204 (ie, the conductive films from the innermost side of the conductive film 204 to the edge of the glass substrate are all transparent and the insulating layer 180). Formed above).

  When some problems such as oxidation or corrosion due to water vapor or the like occur in an area other than the area covered by the seal, the transparent conductive films 202 and 204 can be formed only in the area covered by the seal, or A protective layer (barrier layer) can be formed so that the transparent conductive films 202 and 204 other than the area covered by the seal can resist water vapor and the like. Accordingly, the curing light 320 from the transistor glass substrate 120 side is irradiated so as not to be blocked by the opaque structure layer, and the inside of the seal is completely cured, so that the liquid crystal can be prevented from being contaminated by the poorly cured seal. .

  During processing, conductive films 200 and 208 are simultaneously formed on the transistor glass substrate through the same mask, and then an insulating layer 180 is formed by photolithography to cover the conductive film, and a hole is formed in insulating layer 180. 240, 242 are formed. Thereafter, the conductive films 202, 204, 206 are simultaneously formed by another mask (photolithography) so as to be electrically connected to the conductive films 200, 208 via the holes 240, 242 separately.

  The conductive films are arranged like a grid (grid). FIG. 1 shows a conductive film parallel to the smearing direction, and FIG. 2 shows a conductive film perpendicular to the direction of applying the seal. The outermost part of the conductive film 208 of the display part needs to be within the range of the liquid crystal 220, and preferably up to the connection surface between the liquid crystal 220 and the seal 160 as shown in FIG.

  The innermost side of the conductive membrane 200 is either within the seal 160 (as shown in FIG. 2) or outside the seal. The conductive film 202 formed on the insulating layer 180 is connected to the conductive films 200 and 208 via the holes 240 and 242 individually.

  As shown in FIG. 2, the conductive film 200 can be replaced by a transparent conductive film 202. According to this, the conductive film from the position where the liquid crystal 220 is connected to the seal to the edge of the glass substrate is entirely formed. It is transparent and is formed on the insulating layer 180.

  When some problems such as oxidation and corrosion due to water vapor or the like occur in an area other than the area covered by the seal, the transparent conductive film 202 can be formed only in the area covered by the seal. A protective layer (barrier layer) can be formed so that the transparent conductive film 202 other than the region covered by the transparent conductive film 202 can resist water vapor or the like. Therefore, the curing light 320 from the transistor glass substrate 120 side is irradiated so as not to be blocked by the opaque structure layer, and the inner part of the seal 160 is completely cured, so that the liquid crystal 220 is contaminated by the poorly cured seal. Can be avoided.

  A major difference of the present invention as compared with the conventional structure, for example, the peripheral structure of the liquid crystal panel as shown in FIG. 3 lies in the structure of the conductive film of the transistor glass substrate. The essence of the invention is to completely cure the seal in contact with the liquid crystal and avoid contamination of the liquid crystal. Therefore, as the material of the conductive film, a transparent conductive material is replaced from the innermost side (that is, the display portion side) of the seal application region, and the end point of the transparent conductive material is within the seal application range, the seal application range. And the edge of the glass substrate.

  The transparent conductive film is formed by the same photolithography as the other structure of the liquid crystal panel based on the process or design of the liquid crystal panel. For example, as shown in FIG. 1, the conductive films 202, 204, and 206 are simultaneously formed with the pixel electrodes. It is formed.

  The preferred embodiments described above are examples for describing the present invention, and do not limit the present invention. The present invention is also applicable to other liquid crystal panel structures, for example, a COA structure in which a color filter is formed on a transistor glass substrate.

  As described above, the conventional method of obliquely irradiating ultraviolet rays and the method of reflecting ultraviolet rays on the bottom plate complicate the curing process and disadvantageously increase the liquid crystal region exposed to ultraviolet rays. On the other hand, in the peripheral structure of the liquid crystal panel of the present invention, the material of the conductive film of the transistor glass substrate in the region where the seal contacting the liquid crystal exists is replaced by a transparent material, and the opaque conductive film is formed. Since the light is not blocked, the light can be completely cured by irradiating the seal from the transistor glass substrate side, and the inconvenience of contaminating the liquid crystal with the poorly cured seal can be avoided. Since the light for curing is perpendicularly incident on the glass substrate to cure the seal and the possibility that the light for curing irradiates the liquid crystal is reduced, the liquid crystal can be maintained at high quality. Further, since the curing light is perpendicularly incident on the glass substrate and cures the seal, the required accuracy of the conditions in the curing step can be eased as compared with the related art.

  The specific embodiments have been described above, but those skilled in the art can make various modifications and changes in accordance with the present invention without departing from the scope defined by the claims of the present application.

It is a figure showing one embodiment of the present invention. FIG. 9 is a diagram showing another embodiment of the present invention. FIG. 9 is a diagram showing a peripheral structure of a conventional liquid crystal panel.

Explanation of reference numerals

Reference Signs List 10: liquid crystal panel 100: color filter glass substrate 120: transistor glass substrate 140: light shielding film 160: seal 180: insulating layer 200, 202, 204, 206, 208: conductive film 220: liquid crystal 240, 242: holes 300, 320 UV light

Claims (4)

In a liquid crystal panel, a first glass substrate and a second glass substrate are attached to each other with a seal, and a surface of the first glass substrate having a light-blocking film faces a surface of the second glass substrate having a thin film transistor.
An inner surface of a surface of the second glass substrate connected to the seal is a display portion of a liquid crystal panel having a first insulating layer and a first transparent conductive film formed on the first insulating layer. Structure around the LCD panel. An outer surface of a surface of the second glass substrate connected to the seal is a non-display portion of a liquid crystal panel having a second insulating layer and a second conductive film formed on the second insulating layer;
2. The structure according to claim 1, wherein the second conductive film and the first transparent film are electrically connected so as to overlap the inner surface and the outer surface. The display portion of the liquid crystal panel inside the surface of the second glass substrate connected to the seal has a third insulating layer and a third conductive film formed on the third insulating layer.
3. The structure according to claim 2, wherein the third conductive film and the first transparent film are electrically connected to a portion where the inner surface and the display unit of the liquid crystal panel overlap. In a liquid crystal panel in which a first glass substrate and a second glass substrate are bonded with a seal, and a surface of the first glass substrate having a light-shielding film faces a surface of the second glass substrate having a thin film transistor,
A region from the innermost surface of the surface of the second glass substrate connected to the seal to the periphery of the liquid crystal panel is a display portion of the liquid crystal panel having an insulating layer and a transparent conductive film formed on the insulating layer. The peripheral structure of the liquid crystal panel.

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