JP2002189225A - Mother substrate for reflection type liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mother substrate for a reflection type liquid crystal display panel which is free from the occurrence of display unevenness by forming dummy electrodes. SOLUTION: A discharge electrode 14 is formed at the outside of a liquid crystal display panel forming area 2 and the end parts positioned on the end side of the liquid crystal display panel forming area 2 of the dummy electrodes 13 are connected with the discharge electrode 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motherboard for a reflection type liquid crystal display panel, and more particularly to a motherboard for a liquid crystal display panel on which dummy electrodes which do not cause display unevenness are formed.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device has been known as a kind of display device for displaying various images such as characters and figures, and a display portion of such a liquid crystal display device includes a pair of substrates for a liquid crystal display panel. A liquid crystal display panel having a liquid crystal sealed between them is used. In addition, as a type of liquid crystal display panel, a reflective liquid crystal display panel that performs display by reflecting light incident from the outside does not use a backlight, so that power consumption, thickness, weight, and cost are reduced. In recent years, it has been frequently used because it is possible to easily realize high density, high image quality, and the like.

In order to realize a bright display, such a reflective liquid crystal display panel is provided with a reflective liquid crystal display panel substrate on the rear surface located on the downstream side in the viewing direction. A configuration in which a polarizing plate is disposed only on the reflective liquid crystal display panel substrate on the front side located on the upstream side (observation side) in the viewing direction, for example, when viewed from the front side located on the upstream side in the viewing direction in the display state, Polarizing plate, transparent substrate,
There is known a configuration in which a transparent electrode, an alignment film, a liquid crystal layer, an alignment film, a transparent electrode, a smoothing layer, a metal reflection layer, and a transparent substrate are arranged in this order.

As an example, a pair of substrates for a reflective liquid crystal display panel formed in a substantially rectangular plane are opposed to each other, the periphery thereof is surrounded by a sealing material, and a space between these opposed substrates for the reflective liquid crystal display panel is provided. There is a reflective liquid crystal display panel formed by enclosing liquid crystal.

Display electrodes formed of transparent electrodes are arranged on the pair of reflective liquid crystal display panel substrates so as to be orthogonal to each other. The intersection of the display electrodes formed on both substrates is a pixel, and the portion where these pixels are formed is a display section for displaying an image. The outside of the display section is a non-display section, and the non-display section includes
Arrangement part (terminal part) of a panel electrode electrically connected to a connection terminal of a flexible circuit board used for supply of electric power and signals, and arrangement of an extraction electrode connecting the display electrode and the panel electrode A part is formed. The arrangement portion of the extraction electrode includes a seal material arrangement portion.

In other words, the transparent electrode of one of the reflective liquid crystal display panel substrates is aligned with the display electrode arranged at the central portion surrounded by the liquid crystal and surrounded by the sealing material and the terminal portion. This is a configuration having a panel electrode arranged and an extraction electrode for connecting each display electrode and each panel electrode. In addition, a plurality of display electrodes that are not involved in display independent of the display electrodes are provided on both outer sides of the aligned display electrodes in the arrangement direction so as to be opposed to the extraction electrodes formed on the other opposite substrate. Dummy electrodes may be arranged in a line.

One end of the dummy electrode in the longitudinal direction is opposed to a side surface orthogonal to the longitudinal direction of the display electrode located on the end side in the arrangement direction of the display electrodes arranged in the display section. The dummy electrode is disposed so that the other end in the longitudinal direction of the dummy electrode faces the panel end face.
This dummy electrode is provided because an alignment film that has been subjected to an alignment treatment such as rubbing in one direction by a roller or the like wrapped with a rubbing cloth is formed on the surface of the display electrode. This is for making the surface condition of the substrate as uniform as possible.

That is, when no dummy electrode is provided,
The height position of the surface of the non-display portion located on the end side in the arrangement direction of the display electrodes formed on the display portion is lower than the height position of the surface of the display portion by the dummy electrode. For this reason, when the dummy electrode is not provided, the contact pressure of the rubbing cloth applied to the surface of the display electrode of the display unit adjacent to the non-display unit during rubbing is reduced. The contact pressure becomes smaller than the contact pressure of the rubbing cloth applied to the surface of the rubbing, and rubbing unevenness occurs, and as a result, display unevenness occurs. In addition, the fact that the contact pressure of the rubbing cloth is different also causes an inconvenience that the rubbing cloth's wear state (pain condition) changes in a relatively short period of time.

The panel electrode, the extraction electrode and the dummy electrode are formed simultaneously with the display electrode when a transparent conductive film such as indium tin oxide (ITO) is patterned by a photolithography method or the like to form a display electrode. ing.
That is, the panel electrode, the extraction electrode and the dummy electrode
The transparent conductive film formed of the same material as the display electrode has the same thickness as the display electrode.

Generally, in order to simultaneously produce a plurality of liquid crystal display panels, a liquid crystal display panel having a plurality of liquid crystal display panel forming regions having display electrodes, extraction electrodes, panel electrodes, dummy electrodes, and the like is formed. A mother substrate is used. Then, after a pair of liquid crystal display panel mother substrates are bonded and liquid crystal is injected into the display portion of each liquid crystal display panel forming area, a portion located in the liquid crystal display panel forming area is separated and divided to separate individual liquid crystal display panels. A panel is formed.

Therefore, in order to simultaneously produce a plurality of reflective liquid crystal display panels, a reflective liquid crystal display panel having a plurality of liquid crystal display panel forming regions having display electrodes, panel electrodes, extraction electrodes, dummy electrodes and the like is formed. A mother substrate for a liquid crystal display panel is used. Further, there are a motherboard for a front panel, which is a motherboard for a reflective liquid crystal display panel located on the upstream side in the viewing direction, and a motherboard for a reflective liquid crystal display panel, which has a metal reflective layer and is located on the downstream side in the viewing direction. After laminating the motherboard for the rear panel and injecting liquid crystal into the display area of each liquid crystal display panel forming area,
Individual reflective liquid crystal display panels are formed by separating and dividing the portion located in the liquid crystal display panel formation region.

When performing color display, a color filter is arranged on one of a pair of reflective liquid crystal display panel substrates, and is generally located on the downstream side in the viewing direction. A color filter is arranged on a portion of the surface of the metal reflective layer of the reflective liquid crystal display panel substrate which is located at the display portion.

FIG. 3 shows the vicinity of a dummy electrode of a mother substrate for a reflective liquid crystal display panel having a light reflecting function used in a conventional reflective liquid crystal display panel. In a mother panel 1 for a rear panel as a substrate, a plurality of display electrodes 4 which are transparent electrodes are provided on a portion to be a display portion 3 in a liquid crystal display panel forming region (only a part is shown) 2 formed in a rectangular shape. Are aligned. A plurality of dummy electrodes 6 which are independent of the display electrodes 4 and which are not involved in display are arranged in a portion to be the non-display portion 5 in the liquid crystal display panel formation region 2. The dummy electrode 6 is disposed in the non-display section 5 located on a side in the direction along the arrangement direction of the display electrodes 4 shown in the vertical direction in FIG. A lower end shown in FIG. 3, which is one end in the longitudinal direction of the dummy electrode 6, is a liquid crystal display panel forming area which is an end side in the arrangement direction shown in FIG. The upper end shown in FIG. 3, which is the other end of the dummy electrode 6 in the longitudinal direction, is disposed so as to face a side surface orthogonal to the longitudinal direction of the display electrode 4 located on the side of the edge of the display electrode 2. , And are disposed so as to face the panel end surface, which is the separation position. In the non-display portion 5, a side portion of the non-display portion 5 in a direction orthogonal to the arrangement direction of the display electrodes 4 shown in the horizontal direction in FIG. Panel electrodes electrically connected to the display electrodes 4 are arranged via extraction electrodes extending from the display electrodes 4. Further, the dummy electrode 6 is formed so as to face an extraction electrode formed on a front panel mother substrate as a reflection type liquid crystal display panel mother substrate.

A general rear panel mother substrate used for color display is formed by providing a plurality of liquid crystal display panel forming regions on a transparent substrate formed in a planar rectangular shape from a transparent material such as glass. I have. Further, a metal reflection layer exhibiting a light reflection function is provided in a portion of the liquid crystal display panel formation region where the display portion is formed and a portion of the non-display portion formation region adjacent to the display portion. ing. This metal reflection layer is formed by evaporating a metal such as aluminum. Further, a color filter for performing color display is provided at a portion serving as a display portion on the surface of the metal reflection layer, and an exposed portion of the transparent substrate, an exposed portion located at a non-display portion of the metal reflection layer, and The surface of the color filter is covered with a smoothing layer formed to be a flat surface by a transparent insulating film such as an acrylic resin. Then, on the flat surface of the smoothing layer, the display electrode, the dummy electrode,
An extraction electrode and a panel electrode are formed. These display electrodes, dummy electrodes, extraction electrodes, and panel electrodes are formed simultaneously with the display electrodes when a transparent conductive film such as indium tin oxide (ITO) is patterned by a photolithography method or the like to form the display electrodes. Have been. That is, the panel electrode, the extraction electrode, and the dummy electrode are formed to have the same thickness as the display electrode by using a transparent conductive film formed of the same material as the display electrode. On the surfaces of the display electrode, the dummy electrode, the extraction electrode, and the panel electrode, an alignment film made of a polymer such as polyimide for arranging liquid crystal molecules in a certain form is provided.
The surface of the alignment film has been subjected to an alignment treatment such as rubbing in one direction with a roller or the like wound with a rubbing cloth, so that the liquid crystal molecules are arranged in the rubbing direction.

[0015]

By the way, in the above-mentioned conventional motherboard 1 for a rear panel as a motherboard for a reflection type liquid crystal display panel, it is impossible to prevent the rubbing unevenness described above by providing the dummy electrodes 6. Although it is possible, since the dummy electrode 6 has a configuration independent of the display electrode 4, the dummy electrode 6 and the metal reflection layer are formed of a smoothing layer formed of an insulating film disposed therebetween, thereby forming a capacitor. Therefore, static electricity (charge) during rubbing is accumulated in the dummy electrode 6. As a result, between the end surface of the dummy electrode 6 and the side surface of the display electrode 4 adjacent to the dummy electrode 6 and located on the end side in the arrangement direction adjacent to the dummy electrode 6, In the case where a discharge is generated and the alignment film formed on the surface of the display electrode 4 which has received the discharge is damaged, when a reflective liquid crystal display panel is formed, abnormal alignment of liquid crystal occurs and display unevenness occurs. There was a problem that there is.

Therefore, a mother substrate for a reflective liquid crystal display panel capable of preventing display unevenness caused by the formation of dummy electrodes, that is, a reflective liquid crystal display panel formed with dummy electrodes free of display unevenness. There is a demand for a motherboard for use.

The present invention has been made in view of these points, and has as its object to provide a motherboard for a reflective liquid crystal display panel on which dummy electrodes having no display unevenness are formed.

[0018]

According to a first aspect of the present invention, there is provided a motherboard for a reflection type liquid crystal display panel, wherein a discharge electrode is formed outside a liquid crystal display panel formation area. The point is that the ends of the dummy electrodes located on the side of the edge of the liquid crystal display panel forming region are connected to the discharge electrodes. By adopting such a configuration, it is possible to prevent the occurrence of rubbing unevenness by making the contact pressure of the rubbing cloth applied to the surface of the display electrode uniform, and at the time of rubbing accumulated in the dummy electrode. The static electricity can be forcibly and easily discharged by the discharge electrode, not between the dummy electrode and the display electrode.
Accordingly, it is possible to prevent discharge from occurring between the dummy electrode and the display electrode, and thus it is possible to obtain a motherboard for a reflective liquid crystal display panel in which display unevenness does not occur.

The feature of the motherboard for a reflection type liquid crystal display panel of the present invention according to claim 2 is that in claim 1,
The connection point between the end face of the dummy electrode facing the display electrode and both side faces along the direction orthogonal to the longitudinal direction of the dummy electrode is formed in a plane curved shape. And
By employing such a configuration, it is possible to more reliably prevent discharge from occurring between the dummy electrode and the display electrode.

Further, the feature of the mother substrate for a reflection type liquid crystal display panel according to the present invention according to claim 3 is that, in claim 1 or 2, the distance between the dummy electrode and the display electrode is opposed to each other. Is set to 10 to 40 μm. By adopting such a configuration, it is possible to more reliably achieve both the function of preventing the occurrence of uneven rubbing and the function of preventing discharge.

[0021]

FIG. 1 is a schematic plan view showing an enlarged main portion near a dummy electrode of a mother substrate for a reflection type liquid crystal display panel according to an embodiment of the present invention.

As shown in FIG. 1, a motherboard 11 for a rear panel as a motherboard for a reflective liquid crystal display panel of the present embodiment has a “panel end face” of FIG. It has a plurality of liquid crystal display panel formation areas 2 shown below the broken line (only one of the plurality of liquid crystal display panel formation areas 2 is shown). These liquid crystal display panel forming regions 2 are formed in a rectangular shape in a plane, and a portion of each liquid crystal display panel forming region 2 serving as a display portion 3 located at a central portion is provided with a plurality of display electrodes serving as transparent electrodes. Electrodes 4 are arranged. In the liquid crystal display panel forming area 2, a portion which is a non-illustrated portion 5 located on a side adjacent to and below the broken line of the “panel end face” in FIG. A plurality of unrelated dummy electrodes 13 are arranged. Further, a discharge electrode 14 extending in parallel with the display electrode 4 is provided outside the liquid crystal display panel formation region 2 shown above the broken line of the “panel end face” in FIG.

The dummy electrode 13 is provided in the non-display section 5 located on a side in the direction along the arrangement direction of the display electrodes 4 shown in the vertical direction in FIG. The lower end shown in FIG. 1, which is one end in the longitudinal direction of the dummy electrode 13, is the end of the display electrodes 4 aligned with the display unit 3 in the arrangement direction shown in FIG. It is disposed so as to face a side surface orthogonal to the longitudinal direction of the display electrode 4 located on the edge side of a certain liquid crystal display panel formation region 2. In addition, the upper end shown in FIG. 1 that is one end of the dummy electrode 13 in the longitudinal direction, that is, the upper end,
An end of the dummy electrode 13 located on the edge side of the liquid crystal display panel formation region 2 is connected to a discharge electrode 14 formed outside the liquid crystal display panel formation region 2.
The static electricity generated during rubbing is accumulated in the discharge electrode 13 having a large capacity and can be discharged by the discharge electrode 13.

The lower end, which is one end of the dummy electrode 13 in the longitudinal direction, which is shown at the bottom in FIG. 1, that is, the end face of the dummy electrode 13 facing the display electrode 4 is perpendicular to the longitudinal direction of the dummy electrode 13. The connecting portions 15 with both side surfaces along the direction in which the rubbing is performed are formed in a plane curve shape, in this embodiment, in an arc shape having a radius of 100 μm or more. Discharge from the electrode 13 toward the display electrode 4 can be prevented by the shape effect. That is, when the lower corner portion of the dummy electrode 13 is formed at an acute angle, discharge is likely to occur.

The dummy electrode 13 and the dummy electrode 1
The distance L between the display electrodes 4 adjacent to the display electrode 3 and the display electrodes 4 adjacent to each other is set to about 20 μm in the present embodiment. This distance L may be formed in the range of about 10 to 40 μm, preferably 15 to 30 μm. If the distance L is longer than this range, the dummy electrode 13 will not be
The contact pressure of the rubbing cloth applied to the surface of the display electrode 4 opposed to the rubbing cloth applied to the surface of the display electrode 4 located at the central portion of the display section 3 tends to cause uneven rubbing. is there. If the distance L is shorter than this range, the rubbing static electricity accumulated in the dummy electrode 13 tends to cause a discharge from the dummy electrode 13 toward the display electrode 4.

FIG. 2 shows a cross-sectional structure of a rear panel mother substrate 11 as a reflection type liquid crystal display panel mother substrate of this embodiment. The rear panel mother substrate 11 of this embodiment is made of a transparent material such as glass. A plurality of liquid crystal display panel forming areas 2 are provided on a transparent substrate 16 formed of a material into a planar rectangular shape. In the liquid crystal display panel forming area 2, the display area 3 is formed, and in the non-display area 5, the area adjacent to the display section 3 is provided with a metal reflection exhibiting a light reflecting function. A layer 17 is provided. The metal reflection layer 17 is formed by evaporating a metal such as aluminum. further,
A color filter 18 for performing color display is provided on a portion of the surface of the metal reflection layer 17 which is to be the display portion 3, and is located at an exposed portion of the transparent substrate 16 and a non-display portion 5 of the metal reflection layer 17. The exposed portion and the surface of the color filter 18 are covered with a smoothing layer 19 formed by a transparent insulating film such as an acrylic resin so that the surface becomes a flat surface. On the flat surface of the smoothing layer 19, the display electrode 4, the dummy electrode 13, an extraction electrode (not shown), and a panel electrode (not shown) are formed. The display electrode 4, the dummy electrode 13, the extraction electrode, and the panel electrode are formed by patterning a transparent conductive film such as indium tin oxide (ITO) on the surface of the smoothing layer 19 by a photolithography method or the like. When forming
It is formed simultaneously with the display electrode 4. That is, the panel electrode, the extraction electrode, and the dummy electrode 13 are formed with the same thickness as the display electrode 4 by the transparent conductive film formed of the same material as the display electrode 4. An alignment film (not shown) made of a polymer such as polyimide for arranging liquid crystal molecules in a predetermined form is disposed on the surfaces of the display electrode 4, the dummy electrode 13, the extraction electrode, and the panel electrode. ing. The surface of the alignment film has been subjected to an alignment treatment such as rubbing in one direction with a roller or the like wound with a rubbing cloth, so that the liquid crystal molecules are arranged in the rubbing direction.

The other configuration is the same as that of a conventionally known mother board for a reflection type liquid crystal display panel having a metal reflection layer, and therefore a detailed description thereof will be omitted.

Next, the operation of this embodiment having the above-described configuration will be described.

According to the motherboard 11 for a rear panel as a motherboard for a reflective liquid crystal display panel of the present embodiment,
The dummy electrode 13 can prevent the occurrence of uneven rubbing by making the contact pressure of the rubbing cloth applied to the surface of the display electrode 4 uniform, and at the edge side of the dummy electrode 13 in the liquid crystal display panel formation region 2. Since the located end is connected to the discharge electrode 14 formed outside the liquid crystal display panel formation region 2, the rubbing static electricity accumulated in the dummy electrode 13 is guided to the large-capacity discharge electrode 14. Discharge can occur at the connection with the discharge electrode 14.

Therefore, according to the rear panel mother substrate 11 of the present embodiment, the dummy electrodes 13 and the display electrodes 4 are provided.
Can be prevented from being generated between the first and second steps, so that display unevenness can be surely suppressed.

Further, according to the rear panel mother substrate 11 of the present embodiment, the end surface of the dummy electrode 13 facing the display electrode 4 and the both side surfaces along the direction orthogonal to the longitudinal direction of the dummy electrode 13 are formed. Since the connection portions 15 are each formed in a plane curve shape, static electricity during rubbing accumulated in the dummy electrode 13 is dissipated from the dummy electrode 13 to the display electrode 4.
It is possible to more reliably prevent the discharge toward the surface by the shape effect.

Further, according to the motherboard 11 for the rear panel of the present embodiment, the distance L between the dummy electrodes 13 and the display electrodes 4 that oppose each other is formed to be about 20 μm. The contact pressure of the rubbing cloth applied to the surface of the display electrode 4 facing the dummy electrode 13 is:
The function of preventing the rubbing cloth from being less than the contact pressure of the rubbing cloth applied to the surface of the display electrode 4 located at the central portion of the display unit 3 to prevent rubbing unevenness, The function of preventing discharge from the electrode 13 toward the display electrode 4 can be more reliably achieved.

The present invention is not limited to the above embodiment, but can be variously modified as needed.

[0034]

As described above, according to the motherboard for a reflection type liquid crystal display panel of the present invention according to the first aspect, the rubbing unevenness is made uniform by making the contact pressure of the rubbing cloth applied to the surface of the display electrode uniform. In addition to preventing occurrence of static electricity, rubbing static electricity accumulated in the dummy electrode can be forcibly and easily discharged by the discharge electrode, not between the dummy electrode and the display electrode. And so on. Therefore, since a discharge can be prevented from being generated between the dummy electrode and the display electrode, an extremely excellent effect such as a reliable motherboard for a reflective liquid crystal display panel without display unevenness can be obtained. Play.

Further, according to the mother substrate for a reflection type liquid crystal display panel of the present invention according to the second aspect, it is possible to more reliably prevent discharge from occurring between the dummy electrode and the display electrode. It has an extremely excellent effect.

Further, according to the mother substrate for a reflection type liquid crystal display panel of the present invention, it is possible to achieve both the function of preventing the occurrence of uneven rubbing and the function of preventing discharge. It has extremely excellent effects, such as being surely possible.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an enlarged main part of an embodiment of a mother substrate for a reflective liquid crystal display panel according to the present invention.

FIG. 2 is a cross-sectional view showing a cross-sectional configuration of the reflective liquid crystal display panel mother substrate shown in FIG. 1;

FIG. 3 is an enlarged schematic plan view showing a main part of a conventional mother substrate for a reflective liquid crystal display panel.

[Explanation of symbols]

2 Liquid Crystal Display Panel Forming Area 3 Display Part 4 Display Electrode 5 Non-Display Part 11 (as Mother Board for Reflective Liquid Crystal Display Panel)
Mother substrate for rear panel 12 Reflective liquid crystal display panel 13 Dummy electrode 14 Discharge electrode 15 Connection part 16 Transparent substrate 17 Metal reflective layer 18 Color filter 19 Smoothing layer

Continuing on the front page (72) Inventor Takeshi Fukui 91 Yotanuki, Miyoshi-shi, Hiroshima Prefecture, Hiroshima Opto Co., Ltd. (Reference) 2H090 HA03 HD03 HD05 HD17 JB02 LA01 2H092 GA64 HA05 NA04 NA14 PA01 PA12 5C094 AA03 BA03 BA43 CA19 EA01 EA04 EA07

Claims (3)

[Claims] 1. A metal reflection layer, a smoothing layer formed of an insulating film covering the metal reflection layer, a plurality of display electrodes formed on the surface of the smoothing layer and used for display, and the display electrode. A reflective liquid crystal display panel motherboard having a plurality of liquid crystal display panel forming regions each having a plurality of dummy electrodes which are independent of display and are not involved in display, and wherein a plurality of the liquid crystal display panel forming regions are formed. Forming a discharge electrode outside the liquid crystal display panel formation region on the substrate;
A mother substrate for a reflective liquid crystal display panel, wherein an end portion of each of the dummy electrodes located on an edge side of the liquid crystal display panel forming region is connected to the discharge electrode. 2. A connection between an end face of the dummy electrode facing the display electrode and both side faces along a direction orthogonal to a longitudinal direction of the dummy electrode is formed in a plane curve shape. The motherboard for a reflective liquid crystal display panel according to claim 1. 3. The reflective liquid crystal display panel according to claim 1, wherein a distance between the dummy electrode and the display electrode facing each other is 10 to 40 μm. Mother board.