JPH02165121A - Liquid crystal electrooptical element - Google Patents

Abstract

PURPOSE:To prevent the light leakage between transparent electrodes and to lower resistance by providing auxiliary electrodes in contact with the transparent electrodes to approximately cover the spacings between the transparent electrodes. CONSTITUTION:The liquid crystal cell is constituted by applying electroless nickel plating in the form of patterns on substrates 12, 13 consisting of glass and forming electrically conductive layers 15 thereon. The electroless nickel patterns are so disposed as to cover the positions between the transparent electrodes 14 when viewed through the cell. Further, a metal surface is exposed while a resin layer 18 is formed and the transparent electrodes 14 are formed thereon. The metallic patterns 15 are formed at the same pitch as the pitch of the transparent electrode patterns 14 at this time. The resulted liquid crystal electrooptical element is free from the light leakage between the transparent electrodes and, therefore, exhibits an excellent contrast characteristic and further the sheet resistance of the transparent electrodes is extremely low.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal electro-optical device, and more particularly to an electrode structure that has low resistance and prevents light leakage between transparent electrodes.

[Prior art] In recent years, FSC (ferroelectric smectic liquid crystal), DSTN
With the advent of (double bar twist type liquid crystal) etc.
The characteristics of liquid crystal electro-optical elements have improved dramatically. This has led to increased display capacity and larger sizes, and the electrode patterns of liquid crystal electro-optic elements have become finer and longer. Therefore, the electrode resistance is required to be lower than before. Moreover, these large-capacity type liquid crystal electro-optical elements have a property that light leakage occurs easily in the gaps between electrodes due to their operating principle. That is, in FSC, between the electrodes where no electric field is applied due to bistability, domains that transmit light and domains that do not transmit light coexist; on the other hand, in DSTN
In this case, the electrode level difference causes light leakage. Conventionally, transparent electrodes for liquid crystal electro-optical elements have been made by forming a thin film of a mixture of indium oxide and tin oxide by sputtering or vapor deposition, and then
Structures have been proposed in which a metal pattern is patterned into a desired shape, or a metal pattern is partially provided on a transparent electrode, as shown in FIG. 2, in order to reduce the resistance.

[Problems to be Solved by the Invention] However, in the above conventional method, although providing a metal pattern on the transparent electrode is effective in reducing resistance, there is a problem in that light leakage between the electrodes cannot be prevented. Ta.

[Means for Solving the Problems] The liquid crystal electro-optical element of the present invention is a liquid crystal electro-optical element in which a liquid crystal is sandwiched between two substrates each having a transparent electrode.
An auxiliary electrode made of a conductor is provided along each transparent electrode on a part of the lower layer of the transparent 17/J electrode of at least one of the substrates, and is in contact with the transparent electrode,
Moreover, the surface opposite to the surface in contact with the transparent electrodes has a size that can substantially cover the gap between the transparent electrodes, and the auxiliary electrode portion has a size that can substantially cover the gap between the transparent electrodes. It is characterized by preventing light transmission.

Hereinafter, the details of the present invention will be shown by examples.

[Example] FIG. 1 shows a schematic cross-sectional view of a liquid crystal electro-optical element in an example of the present invention. In the figure, 10 is a liquid crystal cell, and 11 is a polarizing plate. For the liquid crystal cell, electroless nickel plating was applied in a pattern on substrates 12 and 13 made of glass, and then electrolytic nickel plating was applied to a thickness of about 15 μm in a width of about 30 μm using a photoresist pattern to form a conductive layer 15. At this time, the electroless nickel pattern was placed so as to cover the positions between the transparent electrodes 14 when viewed through the transparent electrodes. Furthermore, about 15 μm of polyimide resin is applied on top of it by screen printing method.
After coating and firing, this substrate was lapped with PVA tokiwa, and then polished using alumina polishing agent on foamed urethane to form resin 418 while exposing the metal surface. Approximately 200 IT○ was applied onto this surface by sputtering.
After 0 persons were placed, patterning was performed with a width of about 300 μm using a photomask to form a transparent electrode i14. Note that, at this time, the metal patterns 15 are formed at the same pitch as the transparent electrode patterns 14. Furthermore, an alignment film made of polyimide is rubbed on top of this to assemble the liquid crystal cell 10, and the liquid crystal 1
6 was enclosed. The obtained liquid crystal electro-optical device exhibits excellent contrast characteristics because there is no light leakage between transparent electrodes.
Furthermore, the sheet resistance of the transparent electrode was approximately 1.1 Ω/hole, which was extremely low compared to the sheet resistance of the transparent electrode used this time, which was approximately 20 Ω/hole. Moreover, this value is about 1/10 of the resistance because the metal part can be larger than the conventional gold fX electrode on a transparent electrode, and the resistance can be significantly lowered.

The above embodiments show a part of the present invention, and although nickel is used as the conductor, other metals, conductive resins, or a combination of these may be used as well. Furthermore, the method of forming metal and resin, the thickness, polishing and grinding conditions, etc. can be selected arbitrarily and are not limited to the conditions of this example.
It is also possible to use the resin layer under the transparent electrode as a color filter by coloring it.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent light leakage between the transparent electrodes of a liquid crystal electro-optic element and also to reduce the resistance. A capacitive liquid crystal electro-optical element has an effect that can be easily obtained.

[Brief explanation of the drawing]

FIG. 1 shows a schematic cross-sectional view of a liquid crystal electro-optic element in an embodiment of the present invention. FIG. 2 shows a schematic cross-sectional view of a conventional liquid crystal electro-optical element. 106 Liquid crystal cell 11, polarizing plate 126 Substrate 13, substrate 14, transparent electrode 15, conductor layer 16, liquid crystal 17, sealant 18, resin layer and above FIG.

Claims (1)

[Claims] (1) In a liquid crystal electro-optical device in which a liquid crystal is sandwiched between two substrates each having a transparent electrode, a portion of the lower layer of the transparent electrode of at least one of the substrates is provided with a portion of each transparent electrode. An auxiliary electrode made of a conductor provided along the transparent electrode is provided in contact with the transparent electrode, and the surface opposite to the surface in contact with the transparent electrode has a size that can substantially cover the gap between the transparent electrodes. In addition, the auxiliary electrode portion is sized to substantially cover the gap between the transparent electrodes, and prevents light transmission.