JPS62215237A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal display device having high storage performance and high contrast by arranging film capable of orienting liquid crystal molecules in a direction horizontal to a substrate to only nonelectrode parts of at least one substrate of a pair of substrates. CONSTITUTION:Indium oxide film is used for a transparent electrode 2, and polyimide is used for a horizontal orientation agent 3. After adhering the polyimide film with a spinner to a glass substrate 1 having the transparent electrode formed by the conventional method, a positive type photoresist is coated on the whole body, and only the nonelectrode part is exposed to light. Then, the photoresist and polyimide on the electrode part are peeled with KOH soln., and the photoresist on the nonelectrode part is peeled with acetone, thus a substrate having orientation film on the nonelectrode part alone is formed. After rubbing the substrate, the substrate is faced oppositely to the substrate which has not been subjected to orientation treatment. Thus, a liquid crystal display device is formed. Ferroelectric liquid crystals are poured therein and cooled slowly.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a liquid crystal display device.

[Prior Art] In the structure of a conventional liquid crystal display device, an alignment film is formed on the entire surface of a substrate to align ferroelectric liquid crystal molecules parallel to and in the same direction as all the substrates.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, the ferroelectric liquid crystal molecules are affected by the polarity of the alignment film, and if the alignment film 1 is present only on one substrate, the memory performance deteriorates. When both substrates have the same, there is a problem that the contrast 7>i decreases.

The present invention is intended to solve these problems, and its purpose is to provide a ferroelectric liquid crystal display device with good memory performance and high contrast.

[Means for Solving the Problems] The liquid crystal display device of the present invention is characterized in that only a non-electrode portion of at least one of a pair of substrates has a film having a property of aligning liquid crystal molecules horizontally to the substrate. do.

[Function] According to the above structure of the present invention, since there is no alignment film in the display portion of the liquid crystal display device and the electrodes are exposed, polarity deviation does not occur on the substrate surface. Therefore, the memory performance deteriorates due to the repulsion between the dipole moment of the ferroelectric liquid crystal and the polarity of the substrate surface, and the contrast occurs due to the generation of a twisted structure of the ferroelectric liquid crystal molecules due to the difference in polarity direction between the upper and lower substrate surfaces. A liquid crystal display device with good memory performance and high contrast can be obtained without causing any deterioration in image quality.

[Example 1] FIG. 1 is a sectional view of a liquid crystal display device in an example of the present invention, in which an alignment film is formed on the non-electrode portion of one substrate. 1 is a glass substrate, 2 is a transparent electrode using an indium oxide film, and 6 is a horizontal alignment agent using cypolyimide.

After applying a polyimide film with a thickness of about tooX using a spinner to a glass substrate on which a transparent electrode has been formed using a conventional method, a positive photoresist is applied to the entire surface and only the non-electrode portion is exposed to light, followed by KOH. The photoresist and polyurethane on the electrode portions were removed using a 1% solution of 1% solution, and the photoresist and polyurethane resin on the non-electrode portions were removed using an acetate bath to produce a substrate having an alignment film of gold only on the non-electrode portions. After rubbing this substrate, the entire liquid crystal display device was fabricated by facing a substrate that had not been subjected to alignment treatment. A ferroelectric liquid crystal was injected into this and slowly cooled.Compared to a conventional liquid crystal display device that has alignment films on the surfaces of both substrates, the liquid crystal display device manufactured in this way has the same memory performance, but the contrast was about 5 times higher.

[Embodiment 2] FIG. 2 is a sectional view of a liquid crystal display device according to an embodiment of the present invention, in which a polyimide film is formed between the electrodes of both substrates. After forming a voloid film between the electrodes of both substrates in the same manner as in Example 1, both substrates were rubbed.
After that, I assembled it in the usual way. Ferroelectric liquid crystal was injected and slowly cooled in the same manner as in Example 1. The contrast of a liquid crystal display device having such a structure is about four times higher than that of a conventional liquid crystal display device.

[Example 5] In Examples 1 and 2, polyimide was used as the alignment agent, but the use of PTA (polyvinyl alcohol) was also effective. In Example 2, slow cooling was performed to obtain uniform orientation, but it was also more effective to use the temperature gradient method in combination □ [Effects of the Invention] As described above, the present invention For example, an alignment film having a property of aligning liquid crystal molecules horizontally to the substrates is formed only on the non-electrode portion of at least one of a pair of substrates.

Since the alignment is performed from that part, the liquid crystal molecules in the display area are not affected by the polarity of the alignment film, so they are energetically stable, and because they are less likely to form a twisted structure, they have good contrast and memory properties. 0 which has the effect of improving

[Brief explanation of drawings]

1 and 2 are main sectional views showing an embodiment of the liquid crystal display device of the present invention. 1...Glass substrate 2...Transparent electrode 5...Alignment film 4...Seal material Fig. 1 Fig. 2

Claims (1)

[Claims] A liquid crystal display device comprising a ferroelectric liquid crystal sandwiched between a pair of substrates, wherein a film having a property of aligning liquid crystal molecules horizontally to the substrates is provided only on the non-electrode portion of at least one of the pair of substrates. A liquid crystal display device characterized by: