Matsushita Electric Industrial Co., Ltd.

Komei Asai

Masakazu Fukai

Seiichi Nagata

Akio Moriyama

Koshiro Mori

Katsuji Hattori

Yoshikazu Hori

Hiroshi Tatsuta

A liquid crystal light valve projection type image display apparatus comprises an electro-optic element and a Schlieren optical system. The electro-optic element has a liquid crystal layer having a dielectric and optical anisotropy. An electric field having a spatial intensity distribution according to an image signal is applied to said liquid crystal at a spatial period, so that a spatially phase-modulated phase diffraction grating is formed in the liquid crystal layer. Thus, a projected image in enlarged form is obtained. The fact that the electric field with a spatial period is applied to the liquid crystal leads to a constant light diffraction angle, and the modulation of the diffraction light intensity in the applied electric field enables an image corresponding to the input image signal to be projected at high light utilization.

Image display apparatus of liquid crystal valve projection type

Apparatus driving liquid crystal display device including a liquid crystal layer provided with electrodes on its two opposite surfaces, comprising means for applying a first signal for designating the electrode position and a voltage signal having a higher frequency to the electrodes on one surface, and for applying an input signal and the signal of said higher frequency to the electrodes on the other surface. The signals are controlled by another signal of different frequency to drive the display device with an ac voltage. Temperature compensation can be performed by varying the magnitude or the frequency of the voltage signal according to the temperature level.

Apparatus for driving liquid crystal display device wherein the signal

In a liquid crystal display device comprising two glass substrate plates positioned in parallel with each other at a nearly constant interval and a liquid crystal interposed between said glass substrate plates, an electrode being provided on each of the opposite surfaces of said glass substrate plates and a voltage being applied between said electrodes, 'haze' which appears at the display surface can be removed by using a liquid crystal composition containing one or more additives capable of controlling the orientation of the liquid crystal molecules (namely, capable of forming a perpendicular orientation phase).

Liquid crystal display device

A liquid crystal composition comprises a liquid crystal and a carboxylic acid or its ester as an additive. By the presence of the additive, the longitudinal axes of liquid crystal molecules can be spontaneously oriented in a direction perpendicular to the surface of a holding wall of a liquid crystal display plate. In particular, the additives may be esters of p-hydroxy- or m-hydroxy-benzoic acid, phenylacetic acids having 1 or 2 hydroxy groups or their esters, phenylpropionic acids having 1 or 2 hydroxy groups or their esters, or 3, 4, 5-trihydroxybenzoic acid esters, or said additives may be selected from the group consisting of compounds having the formulae: ##SPC1## Wherein R.sub.3 is hydrogen or a normal alkyl group having 1 to 18 carbon atoms; R.sub.5 is hydrogen, hydroxy, a normal alkyl group having 1 to 16 carbon atoms or a normal alkoxy group having 1 to 16 carbon atoms; R.sub.6 is hydrogen, hydroxy or nitro; n.sub.1 is 1 or 2: and n.sub.2 is 0, 1 or 2.

Liquid crystal composition

A nematic liquid crystal with positive dielectric anisotropy and a nematic liquid crystal with negative dielectric anisotropy are mixed such that the mixture is given a positive dielectric anisotropy and whenever any kind of pleochroic dye is dissolved therein, can effectively utilize its absorption anisotropy for display performances. A clear color-to-color contrast display is provided by employing the mixed liquid crystal added with pluralkinds of dyes of which at least one is a pleochroic dye and at least two are different in hue and in preformance characteristics of display device.

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Hirakata, Japan

Komei Asai