JPH0124315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display device. More specifically, the present invention relates to an improvement in a liquid crystal display device using a flexible polymer film as a substrate.

A conventionally known liquid crystal display panel consists of two substrates, each made of inorganic glass or flexible polymer film, each provided with an electrode pattern, and bonded together with an adhesive at a distance with the electrode mounting surface facing inside. Parts of both electrodes are connected vertically with a conductive member, a liquid crystal material is sealed between the raised plates, and a voltage is applied to the liquid crystal layer to change its optical characteristics and display characters, figures, etc. It is what it is. Among these, liquid crystal display devices using flexible polymer films as substrates are lightweight, impact resistant, and capable of displaying curved surfaces. Unevenness and a decrease in contrast were likely to occur. The inventor investigated the cause and found that segment electrodes, common electrodes, and
When installing thin film electrodes such as lead electrodes, etching removes the thin film electrodes in areas unrelated to the display, so there is a difference in unevenness between the areas where the thin film electrodes are attached to the film substrate and the areas where they are not. Ta. In addition, these parts have different degrees of thermal expansion and contraction, and when the ambient temperature changes, distortion occurs and the film substrate warps, and if such a substrate is used to create a liquid crystal display device, it is difficult to maintain uniform gaps between the substrates. It turned out to be. Therefore, these problems could not be solved no matter how much the film substrate was reinforced from the outside.

Therefore, the inventors of the present invention have completed the present invention as a result of continued research in order to eliminate the above-mentioned causes and obtain a liquid crystal display device that does not have the above-mentioned drawbacks even though a flexible polymer film is used as a substrate.

That is, the gist of the present invention is to provide a liquid crystal display device in which flexible polymer film substrates each having thin film electrodes such as segment electrodes, common electrodes, and lead electrodes on the inside thereof are disposed facing each other, and liquid crystal is sealed between the two substrates. A dummy electrode made of the same material as at least one of the segment electrode, common electrode, and lead electrode is formed in a region close to each electrode inside the flexible polymer film substrate. It's on the liquid crystal display.

The present invention will be described in detail below along with an example. Reference numerals 1 and 2 are an upper substrate and a lower substrate made of flexible polymer films such as polyethylene terephthalate film, polybutylene terephthalate film, polyether sulfonate film, and polycarbonate film. They are used by placing them facing each other. Mocon electrodes 3 and segment electrodes 4 are provided on the inner surfaces of the upper and lower substrates 1 and 2 using transparent conductive films such as indium oxide and tin oxide. These electrodes 3 and 4 are connected to an external circuit via a lead electrode 5 so that an electric field is applied thereto. and segment electrodes 4 on the substrates 1 and 2;
In areas other than the common electrode 3 and lead electrode 5, dummy electrodes 6 having the same components as these electrodes and not directly related to the liquid crystal display are provided at regular intervals. This dummy electrode 6 is not electrically connected to anything and is an independent entity, that is, it is a transparent electrode provided independently of the signal electrode and the display electrode, and no electric field is applied or no electric field is applied. It is an electrode arranged so that it does not display or obstruct the display even when the screen is displayed, and is usually a metal film made of the same material as the display electrode. The narrower the distance between the cement electrode 4, the common electrode 3, the lead electrode 5, etc., the better for achieving the object of the present invention, but it is preferably about 50 to 150 μm to prevent short circuits. An alignment film 7 made of a mixture of saturated polyester and nylon is formed on the electrodes 3, 4, and 6, and a gap material 8 made of synthetic resin particles such as vinylbenzene copolymer is formed on the alignment film 7. It is coated. The upper and lower substrates 1 and 2 are coated with an adhesive 1 such as a silicone adhesive or a Shigai wire-curing adhesive.
1 or sealed in an overlapping state by ultrasonic fusion or the like, liquid crystal 9 is sealed in the resulting space, and polarizing plates 10 are superimposed on the outside of the upper and lower substrates 1 and 2. Depending on the case, a reflecting plate may be further overlapped.

As described above, the present invention relates to a liquid crystal display device characterized in that dummy electrodes unrelated to display are provided in areas other than the segment electrodes, common electrodes, and lead electrodes inside a flexible polymer film substrate. It is.

Therefore, the dummy electrodes are uniformly provided over the entire surface of the polymer film substrate except for the area around the electrodes. Therefore, the gap between the film substrates of the electrode and the dummy electrode around the electrode is equal, and the gap unevenness is eliminated. Furthermore, since the dummy electrode is made of the same material as the electrode, the substrate will not warp due to a difference in thermal expansion/contraction even if the ambient temperature changes. Furthermore, even when the liquid crystal display device is used in a bent position, the electrodes and the dummy electrodes formed close to the electrodes are made of the same material, so the mechanical strength is the same and prevents warping and uneven gears between the substrates. It can be suppressed.

In this way, even if a flexible polymer film is used as a substrate, it is possible to accurately control the gap between the substrates, reduce variations in response speed to display operations, and reduce the refractive index of the partial substrate.
Differences in reflectance can be eliminated, and color unevenness and contrast deterioration can be prevented.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a plan view showing a part of the inner side between the substrates of the same example. 1... Upper substrate, 2... Lower substrate, 3... Common electrode, 4... Segment electrode, 5... Lead electrode,
6...Dummy electrode.

Claims (1)

[Scope of Claims] 1. A liquid crystal display device in which flexible polymer film substrates having thin film electrodes such as segment electrodes, common electrodes, and lead electrodes on the inside are disposed facing each other, and liquid crystal is sealed between the two substrates, A dummy electrode made of the same material as at least one of the segment electrode, common electrode, and lead electrode is formed in a region close to each electrode inside the flexible polymer film substrate. LCD display device.