JPS62169121A - Ferroelectric liquid crystal display - Google Patents

Abstract

PURPOSE:To inhibit deterioration in contrast caused by the twist structure characteristic to a ferroelectric liquid crystal, to retard also occurrence of discrimination, and to improve the storage characteristic of a ferroelectric liquid crystal display by changing orientation treatment of two liquid crystal inserting substrates. CONSTITUTION:SiO2 is obliquely vapor-deposited with 40-85 deg. angle to a liquid crystal inserting substrate 3 at one side and an orienting agent such as PVA is coated on another substrate 4 and rubbed. By this constitution, dipoles at the PVA-treated side are directed toward the inside of a cell, but directed toward substrate at the SiO2-treated side. Thus, the dipoles are distributed in the range from upper substrate to lower substrate being oriented in one direction, so the deterioration of contrast in the storage state, deterioration of storage characteristic due to discrimination caused by twist, and deterioration of threshold characteristic are retarded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a liquid crystal holding substrate of a ferroelectric liquid crystal display device.

[Summary of the invention]

In the present invention, in a ferroelectric liquid crystal display device fl, by changing the alignment film J of two liquid crystal holding substrates, deterioration of contrast, propagation, and disclination occur due to the twisted structure peculiar to ferroelectric liquid crystal. It also improves memory performance.

[Conventional technology]

The structure of the liquid crystal holding substrate of the conventional ferroelectric liquid crystal display (vAtft) is to orient the liquid crystal in one direction by applying an alignment agent and rubbing it, or is the liquid crystal brittle? After encapsulation, a magnetic field is applied to orient the particles, so no surface treatment is required.

[Problems to be solved by invention 5] However, the above-mentioned conventional technology does not take into account the twist hZ in the memory state (the molecular direction does not change even after the driving voltage is cut off), which is unique to ferroelectric liquid crystals. .

Here, the twist refers to the dipole hi of the ferroelectric liquid crystal on the surface of the liquid crystal sandwiching substrate, as shown in FIG.

The upper and lower plates are placed in the 5th direction in a symmetrical direction. When a twisted structure occurs, the optical anisotropy h of the molecules does not match, and the contrast deteriorates. One molecule ht one direction? Due to unsuitable conditions, discrepancy (defects) occur, and the subsequent deterioration of missing value characteristics.
Deterioration of memory performance occurs. So, the goal is to solve this 5-year-old problem, and what is its purpose and origin? The present invention provides an orientation means that does not cause twisting, which is the original drawing.

[Means for solving the problem of 11 yen] The medium-induced liquid crystal display device of the present invention has a liquid crystal holding plate rs on one side.
It is characterized in that it is obliquely evaporated at an angle of 85 degrees, and an alignment agent such as PVA is applied to one of the substrates, followed by rubbing. In oblique evaporation with an EJi of 0.40° or less, the effect ht is lost when a PVA-treated substrate is used.

[Effect]

According to the above configuration of the present invention, the dipole is oriented toward the inside of the cell on the first side of PVAILfW'4t, and is oriented toward the substrate on the next side (see Figure 2). Is that refined dipole unidirectional from the top board to the bottom board? If you apply the same treatment to the upper and lower boards (IE 31'l!l
), no twist occurs. This effect results in a degradation of contrast in the memory state.

Memory deterioration and threshold characteristic deterioration due to disclination caused by twisting can also be suppressed.

〔Example〕

FIG. 1 is a sectional view of a liquid crystal display device according to a seventh embodiment of the present invention. After forming the TO cap on the glass substrate, RiCh
With the vertical direction of the substrate set to 00, it is obliquely deposited at an angle of 40° to 85°. prepare. PVk solution on the glass plate after ITO pus formation? After coating, dry and rub to prepare t41. Contains polyethylene film (4μm thick),
Heat and press. (Cell thickness is 2 to 5 am) In addition to this, ester-based liquid crystal RO-@-C02J5;,-OR'' (R=o
oH1o, R' = -cHt-1''H(aHs
)-U)+, the upper and lower substrates are symmetrically processed. In the next case, the black level hZ looks blue in the BmO phase under a Snicol, but in this case it is pure black and the memory performance is also good (it
Pressure? There is almost no change in the amount of light even when the light is turned off.

Nakata.

As for the threshold value characteristics, the ratio of the saturation voltage to 1 voltage is also very good, tl at 40°C.

In addition to this embodiment, ptyA having the same effect can be used in the same manner.

〔Effect of the invention〕

As described above, according to the invention, one side of the upper and lower stem plates is Bi.
By performing Ot oblique evaporation and dipping the alignment agent on the other hand, twist can be eliminated, resulting in high contrast, memory properties, Lttl, -.

It is possible to maintain good value characteristics.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a ferroelectric liquid crystal display device of the present invention. FIG. 2 is a cross-sectional view of the liquid crystal orientation of the present invention. Figure 8J3 is a cross-sectional view of conventional liquid crystal alignment. that's all

Claims (1)

[Claims] A ferroelectric liquid crystal display device characterized in that the direction of spontaneous polarization of liquid crystal is defined near alignment films on two plates that sandwich the ferroelectric liquid crystal.