Abstract: An object of the invention is to provide a method of introducing sightly tilting homeotropic orientation into a liquid crystal layer by oblique evaporation of inorganic material by one step, and a further object is to apply this method to provide a reliable liquid crystal electro-optical device or a liquid crystal light valve.FIG. 1 shows an example of the method to introduce the slightly tilting homeotropic orientation into the liquid crystal layer by the one step of the oblique evaporation of the inorganic material. The orientation film is formed by the one step oblique evaporation. An incident angle is set from 45.degree. to 70.degree. relative to a parallel direction of the substrate, and a film thickness is set to 20 nm through 500 nm measured during the film deposition by a film thickness gage disposed at a vertical distance equal between the evaporation source and the substrate. The orientation film is used in the liquid crystal electro-optical device or the liquid crystal light valve.

Abstract: By using a ferroelectric liquid crystal light valve having a hydrogenated amorphous silicon photoconductive layer, a spatial light modulator may be driven by a method comprising the sequential application of successive pulse voltages of selective amplitude, polarity and duration to cause the spatial light modulator to manifest a second threshold level suitable for application of the device in Boolean processing applications and Fourier image processing.

Abstract: An edge image extraction light modulator forms an edge portion image corresponding to a boundary between two optically equalized portions of a liquid crystal layer. Each portion has a different bistable state and an edge portion optically distinct from the two optically equalized portions. An optical image is written onto the light valve while applying a voltage between two transparent electrode layers of the light valve to effect switching between a first stable optical axis and a second stable optical axis. The light valve is illuminated and the edge portion of the written image is read. A first and a second polarizer are in crossed-Nicols position so that the two optically equalized portions comprise a portion having the written image except for the edge portion thereof and a non-written portion. The edge portion is not optically equal to the two optically equal portions and can thus be detected.

Abstract: The present invention is concerned with point/output characteristics of a light input image having density gradation using a light writing type light valve comprising a combination of a hydrogenated amorphous silicon photoconductor and a ferroelectric liquid crystal. More specifically, the invention relates to a method of expressing continuous gradation using a light writing type ferroelectric liquid crystal light valve that has been difficult to realize. The expression of continuous gradation is made possible by superposing a DC bias voltage of from 0.1 V to 10 V on a rectangular-wave voltage or a bipolar pulse voltage that has theretofore been used as a driving voltage in order to strongly couple together the spontaneous polarization of ferroelectric liquid crystal and the polarity of the DC voltage, and by eliminating the bistability exhibited by the ferroelectric liquid crystal while developing a monostable condition.