JP2002202521A - Reflection type liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type liquid crystal display panel in which a dummy electrode is formed without generating display irregularity. SOLUTION: A discharging gap is provided in the middle section of a dummy electrode along its longitudinal direction. Then, static electricity generated during rubbing and accumulated in the dummy electrode is discharged not between the dummy electrode and display electrodes, but is forcibly, surely and easily discharged by the discharging gap provided in the dummy electrode. Thus, discharging between the dummy electrode and the display electrodes is prevented and a reflection type liquid crystal display panel which does not generate display irregularity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display panel, and more particularly to a reflection type liquid crystal display panel having a dummy electrode which does not cause display unevenness.

[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.

[0003] In order to realize a bright display, such a reflective liquid crystal display panel has a reflective liquid crystal display panel on the back side located downstream in the viewing direction, and has a light reflecting function. A polarizing plate disposed only on the reflection type liquid crystal display panel on the front side located on the upstream side (observation side), such as a polarizing plate, transparent when viewed from the front side located on the upstream side in the viewing direction in the display state. There is known a configuration in which a substrate, 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 liquid crystal display panel formed in a substantially rectangular plane are opposed to each other, the periphery is surrounded by a sealing material, and liquid crystal is sealed between the opposing surfaces of the substrates for the liquid crystal display panel. There is a reflection type liquid crystal display panel formed as a result.

On the pair of reflective liquid crystal display panel substrates, display electrodes composed of transparent electrodes are arranged 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 has a panel electrically connected to connection terminals of a flexible circuit board as an external drive circuit used for supplying power and signals. An electrode arrangement part (terminal part) and an extraction electrode arrangement part for connecting the display electrode and the panel electrode are 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 other end of the dummy electrode in the longitudinal direction is arranged so as to face the panel end surface. 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.

FIG. 3 shows the vicinity of a dummy electrode of a conventional reflection type liquid crystal display panel.
Is provided with a metal reflection layer 3 exhibiting a light reflection function on a transparent substrate 2 formed in a substantially rectangular plane by a transparent material such as glass, and the surface of the metal reflection layer 3 is made of a transparent material such as an acrylic resin. A first display electrode 6 is provided on a portion of the surface of the smoothing layer 4 which is to be the display section 5 and a non-display portion of the surface of the smoothing layer 4 is covered with the smoothing layer 4 formed of an insulating film. A panel electrode and a dummy electrode 8 (not shown) are provided in a portion to be the display section 7, and polyimide or the like for arranging liquid crystal molecules in a predetermined form on the surface of the first display electrode 6, the panel electrode and the dummy electrode 8 Is provided by providing an alignment film (not shown) made of the above polymer. Further, the surface of the alignment film is subjected to an alignment treatment such as rubbing in one direction by a roller or the like wound with a rubbing cloth, so that the liquid crystal molecules are arranged in the rubbing direction.

The metal reflective layer 3 formed on the transparent substrate 2 of the rear-side transparent electrode substrate 1 is adjacent to the display area 5 of the area where the display area 5 is formed and the area where the non-display area 7 is formed. It is formed by depositing a metal such as aluminum on the site. Further, the smoothing layer 4 of the rear transparent electrode substrate 1 is formed of an insulating film such as an acrylic resin, and is formed so as to cover the exposed portion of the surface of the transparent substrate 2 and the surface of the metal reflection layer 3. I have. The panel electrodes of the rear-side transparent electrode substrate 1 are arranged and arranged so as to extend from the first display electrode 6 on the side of the non-display portion 7 along the direction in which the first display electrodes 6 are arranged. Have been. Furthermore, the dummy electrode 8 of the rear transparent electrode substrate 1 is independent of the first display electrode 6 on a side of the non-display portion 7 in a direction orthogonal to the arrangement direction of the first display electrode 6. It is arranged in a state, and is formed at a position facing the second extraction electrode 16 formed on the front transparent electrode substrate 11 shown in FIG.

As shown in FIG. 3, the front transparent electrode substrate 11 on the front side, which is located on the upstream side in the viewing direction of the reflective liquid crystal display panel facing the rear transparent electrode substrate 1, has a transparent substrate 12 as shown in FIG. A second display electrode 14 is provided on the display unit 13 on the front surface, a second extraction electrode 16 and a panel electrode (not shown) are provided on the non-display unit 15, and the second display electrode 14 and the second extraction electrode 16 are provided. Alignment film (not shown) on the surface of
Is generally used.

When color display is performed, a color filter is provided on one of the rear-side transparent electrode substrate 1 and the front-side transparent electrode substrate 11, and the color filter is provided on the rear-side transparent electrode substrate 1. 3, a color filter 9 is provided at a portion of the surface of the metal reflective layer 3 which is located on the display section 5 as shown by a broken line.

Further, in general, a plurality of liquid crystal displays each having a display electrode, an extraction electrode, a panel electrode, a dummy electrode, and the like are required to simultaneously form a plurality of rear transparent electrode substrates and front transparent electrode substrates. A mother substrate for a liquid crystal display panel on which a panel formation region is formed is used.
Then, after a pair of mother substrates for liquid crystal display panels are overlapped, a portion located in the liquid crystal display panel formation region is divided to obtain individual liquid crystal display panels.

[0015]

In the conventional rear-side transparent electrode substrate 1 described above, the provision of the dummy electrodes 8 can prevent the rubbing unevenness described above. Since the structure is independent of the display electrode 6, the dummy electrode 8 and the metal reflective layer 3 have a capacitor structure by the smoothing layer 4 formed by an insulating film disposed between them. Static electricity (charge) during rubbing is accumulated on the electrode 8. As a result, as shown in FIG. 4, the dummy electrode 8 is located between the end surface of the dummy electrode 8 and the side surface of the first display electrode 6 positioned adjacent to the dummy electrode 8 in the arrangement direction.
Discharge occurs from the end surface of the first display electrode 6 to the side surface of the first display electrode 6, and the alignment film formed on the surface of the first display electrode 6 that has received the discharge is damaged. In addition, there is a problem in that the alignment abnormality of the liquid crystal occurs and display unevenness may occur.

Therefore, there is a need 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. ing.

The present invention has been made in view of the above points, and an object of the present invention is to provide a reflective liquid crystal display panel having a dummy electrode on which display unevenness does not occur.

[0018]

According to a first aspect of the present invention, there is provided a first transparent electrode substrate comprising a first transparent electrode substrate and a second transparent electrode substrate sandwiching a liquid crystal. On the side, a metal reflective layer, a smooth layer formed of an insulating film, and a plurality of first display electrodes formed in a stripe shape are laminated, and formed in a stripe shape on the second transparent electrode substrate side. In a reflective liquid crystal display panel provided with a plurality of second display electrodes provided so as to be orthogonal to the first display electrodes, the second display electrodes and the external drive are provided on the second transparent electrode substrate side. A second extraction electrode connecting to a panel electrode connected to a circuit is formed, and a position on the first transparent electrode substrate side independent of the first display electrode and opposed to the second extraction electrode. Dummy electrodes are provided in the It is characterized in that the discharge gap is provided in the middle portion in the longitudinal direction of the over electrodes. By adopting such a configuration, static electricity during rubbing accumulated in the dummy electrode is forcibly and easily forcibly secured not by the gap between the dummy electrode and the display electrode but by the discharge gap provided in the dummy electrode. Can be discharged. Therefore, since a discharge can be prevented from being generated between the dummy electrode and the display electrode, it is possible to obtain a reflective liquid crystal display panel in which display unevenness does not occur.

The invention according to claim 2 is characterized in that, in claim 1, the discharge gap is provided at the position where the metal reflection layer is formed. By adopting such a configuration, it is easy to smoothly discharge the static electricity accumulated in the dummy electrode in the discharge gap during rubbing.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. The same or corresponding components as those of the above-described conventional device are denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted.

FIG. 1 is a cross-sectional view showing a main part of an embodiment of a reflection type liquid crystal display panel according to the present invention, and FIG. 2 is a partially enlarged plan view of the first transparent electrode substrate near the panel end face.

As shown in FIG. 1, in this embodiment, a rear transparent electrode substrate (first transparent electrode substrate) 21 has a metal reflective layer 3 having a light reflecting function provided on a transparent substrate 2. I have. The display unit 5 on the metal reflection layer 3 is provided with a color filter 9 for performing color display.
The exposed portions of the metal reflective layer 3, the color filter 9, and the transparent substrate 2 are all covered with a smoothing layer 4 formed of an insulating film such as an acrylic resin. The display unit 5 is provided with first display electrodes 6 arranged in a stripe pattern.

The non-display portion 7 on the surface of the smoothing layer 4 is provided with a panel electrode, a first extraction electrode (not shown), and a dummy electrode 22 arranged in a predetermined pattern. The panel electrodes are formed on the sides of the non-display section 7 along the direction in which the first display electrodes 6 are arranged. The dummy electrodes 22 are formed on the first display electrodes of the non-display section 7. 6 are arranged on the sides in the direction orthogonal to the arrangement direction. These first display electrodes 6, panel electrodes,
An alignment film (not shown) is provided on the surfaces of the first extraction electrode and the dummy electrode 8. The surface of this alignment film is
An alignment process is performed by 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 first display electrode 6, the panel electrode, the first extraction electrode, and the dummy electrode 22 of the rear transparent electrode substrate 1 are made of indium tin oxide (IT
The transparent conductive film such as O) is simultaneously formed by patterning by a photolithography method or the like.

The dummy electrode 22 of the present embodiment is located at a position facing the second extraction electrode 16 formed on the front transparent electrode substrate (second transparent electrode substrate) 11 shown in FIG. In a state independent of the display electrode 6, the non-display portion 7 is provided on a side portion of the non-display portion 7 in a direction orthogonal to the arrangement direction of the first display electrodes 6. This dummy electrode 22
Are formed in two parts along the longitudinal direction, and a discharge gap 23 for forcibly discharging static electricity during rubbing accumulated in the dummy electrode 22 is formed in an intermediate part in the longitudinal direction. I have.

That is, as shown in FIGS. 1 and 2,
The dummy electrode 22 of the present embodiment is formed into two parts, one dummy electrode 22a located on the panel end face side and the other dummy electrode 22b located on the display unit 5 side, as shown in FIG. As described above, in order to easily generate a discharge, the opposing portion between the two electrodes 22a and 22b is made substantially triangular in plane, and the two electrodes 22a and 22b are disposed so that their respective tops face each other.

Incidentally, as shown in FIG.
The distance G between the first and second display electrodes 6 is equal to or smaller than the distance D between the end face of the dummy electrode 22 b and the side surface of the first display electrode 6. This is preferable in that the forced discharge can be reliably performed in the discharge gap 23 formed in the intermediate portion of the dummy electrode 22 that is not involved in display without causing a discharge between the first electrode 6 and the first display electrode 6.

The discharge gap 23 is formed on the surface of the smoothing layer 4 located in the non-display portion 7 above the portion where the metal reflective layer 3 is formed. This is preferable in that the discharge of the static electricity during rubbing accumulated in the rubbing can be easily performed in the discharge gap 23.

The other configuration is the same as that of the conventional rear-side transparent electrode substrate 1, and a detailed description thereof will be omitted.

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

According to the rear transparent electrode substrate 21 of the reflection type liquid crystal display panel of the present embodiment, the dummy electrode 22
Since the contact pressure of the rubbing cloth applied to the surface of the display electrode 6 can be made uniform to prevent rubbing unevenness, and because the discharge gap 23 is formed in the longitudinal middle part of the dummy electrode 22. The rubbing static electricity accumulated in the dummy electrode 22 is transferred to the first
Discharge can be forcibly and easily performed forcibly in the discharge gap 23 provided in the dummy electrode 22 instead of between the display electrode 6.

Therefore, according to the rear transparent electrode substrate 21 of the present embodiment, the dummy electrode 22 and the first display electrode 6
Since a discharge can be prevented from occurring between the reflective liquid crystal display panel and the display device, a reflective liquid crystal display panel free from display unevenness can be reliably and easily obtained.

The rear transparent electrode substrate 2 of the present embodiment
According to 1, since the discharge gap 23 is provided above the metal reflective layer 3, it is easy to smoothly discharge static electricity accumulated in the dummy electrode 22 in the discharge gap 23 during rubbing. This is presumably because the metal reflective layer 3 located below the discharge gap 23 plays a role of a trigger gap in the surge arrester.

The present invention is not limited to the above embodiment, but can be variously modified as needed. For example, a mode of a transflective liquid crystal display panel in which a metal reflective layer is translucent is also included.

[0034]

As described above, according to the reflective liquid crystal display panel of the first aspect of the present invention, static electricity during rubbing accumulated in the dummy electrode is not generated between the dummy electrode and the display electrode. In addition, an extremely excellent effect is obtained such that the discharge can be forcibly and easily discharged forcibly by the discharge gap provided in the dummy electrode. Therefore, since discharge can be prevented from being generated between the dummy electrode and the display electrode, an extremely excellent effect such as a reflective liquid crystal display panel free from display unevenness can be obtained.

Further, according to the reflection type liquid crystal display panel of the present invention according to the second aspect, it is extremely excellent that the discharge in the discharge gap of the static electricity accumulated at the dummy electrode during rubbing can be easily performed smoothly. Has the effect.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of a reflective liquid crystal display panel according to the present invention.

FIG. 2 is a partially enlarged plan view of the rear transparent electrode substrate shown in FIG.

FIG. 3 is a sectional view showing a main part of a conventional reflective liquid crystal display panel.

FIG. 4 is a partially enlarged plan view of the vicinity of a panel end surface of the rear-side transparent electrode substrate shown in FIG. 3;

[Explanation of symbols]

 1, 21 Rear transparent electrode substrate (first transparent electrode substrate) 2, 12 Transparent substrate 3 Metal reflective layer 4 Smoothing layer 5 Display unit 6 First display electrode 7 Non-display unit 9 Color filter 11 Front transparent electrode substrate (Second transparent electrode substrate) 14 Second display electrode 16 Second extraction electrode 22, 22a, 22b Dummy electrode 23 Discharge gap

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Fukui 91 Yoginuki, Miyoshi-shi, Hiroshima Hiroshima Opto Co., Ltd. F term (reference) 2H091 FA14Y FB08 GA03 GA06 LA07 2H092 GA32 NA12 NA14 PA08

Claims (2)

[Claims] A first transparent electrode substrate sandwiching a liquid crystal and a second transparent electrode substrate;
A transparent electrode substrate, wherein the first transparent electrode substrate side includes:
A metal reflective layer, a smooth layer formed of an insulating film, and a plurality of first display electrodes formed in stripes are laminated, and a plurality of stripe-shaped first electrodes are formed on the second transparent electrode substrate side. Wherein the second display electrode is provided so as to be orthogonal to the first display electrode, wherein the second display electrode is connected to the external drive circuit on the second transparent electrode substrate side. A second extraction electrode connected to the panel electrode, and a dummy electrode is provided on the first transparent electrode substrate side independently of the first display electrode and at a position facing the second extraction electrode. A reflective liquid crystal display panel, wherein a discharge gap is provided at an intermediate portion in a longitudinal direction of the dummy electrode. 2. The reflection type liquid crystal display panel according to claim 1, wherein the discharge gap is provided at a position where the metal reflection layer is formed.