Abstract: A high-speed responsive liquid crystal optical device with improved light transmissivity is provided. The device includes a liquid crystal panel including an optically active liquid crystal material having dielectric anisotropy which becomes zero at a crossing frequency ("fc") of 100 KHz or below. The dielectric anisotropy of the liquid crystal is positive at frequencies lower than fc ("fl") and negative at frequencies higher than fc ("fh"). Crossed polarizers are disposed on each side of the liquid crystal panel. A liquid crystal driving circuit selectively applies a signal of a frequency fh to open the device and a signal of a frequency fl to close the device. The optical device is particularly well suited for use as a light valve in a printer device. Response time within 1 m sec. permits a printing speed of 10 prints of A4 size to be produced per minute with a resolving power of about 10 dots per 1 m/m.

Abstract: A printing apparatus for use in a printer with a photo-sensitive drum. The printing apparatus includes a spotlight source for generating a light provides essentially a point source. A photo-optical converter which is optically coupled to the spotlight source converts the light from the spotlight source to linear rays of light. A plurality of microshutters optically coupled to the photo-optical converter selectively transmits the light at selected portions of the array to the photo-sensitive drum. As a result, a light path is defined from the spot-light source through the photo-optical converter and the microshutters to the photo-sensitive drum.

Abstract: A liquid crystal light shutter having means for stabilizing molecular orientation of a liquid crystal material is provided. In one embodiment of the invention, isolation electrodes are provided parallel to and between adjacent common electrodes on a substrate. In an alternate embodiment, the effective gap distance between adjacent common electrodes is at least ten times greater than the distance between opposing substrates.

Abstract: A high-speed responsive liquid crystal optical device with improved light transmissivity is provided. The device includes a liquid crystal panel including an optically active liquid crystal material having dielectric anisotropy which becomes zero at a crossing frequency ("fc") of 100 KHz or below. The dielectric anisotropy of the liquid crystal is positive at frequencies lower than fc ("fl") and negative at frequencies higher than fc ("fh"). Crossed polarizers are disposed on each side of the liquid crystal panel. A liquid crystal driving circuit selectively applies a signal of a frequency fh to open the device and a signal of a frequency fl to close the device.The optical device is particularly well suited for use as a light valve in a printer device. Response time within 1 m sec. permits a printing speed of 10 prints of A4 size to be produced per minute with a resolving power of about 10 dots per 1 m/m.

Abstract: A printing apparatus for use in a printer with a photo-sensitive drum. The printing apparatus includes a spotlight source for generating a light provides essentially a point source. A fiber-optical converter which is optically coupled to the spotlight source converts the light from the spotlight source to linear rays of light. A plurality of shutter window optically coupled to the fiber-optical converter selectively transmits the light at selected portions of the array to the photo-sensitive drum. As a result, a light path is defined from the spotlight source through the fiber-optical converter and the microshutters to the photo-sensitive drum.

Abstract: An electrostatic printer for printing images on an electrostatic recording medium. The electrostatic printer includes an elongated electrode and a back electrode. The back electrode is spaced from the elongated electrode to define a gap therebetween. The gap, defined by the elongated electrode and the back electrode, is adapted to permit the passage of the electrostatic recording medium in a predetermined direction and is effectively reduced at a given point on the elongated electrode. The elongated electrode is displaceable relative to the back electrode so that the point on the elongated electrode which then defines the effectively reduced gap is displaced laterally of the direction of passage of the electrostatic recording medium in response to the displacement of the elongated electrode.

Abstract: An electro-photographic printer utilizing a liquid crystal material which operates as a light valve. The liquid crystal material is sandwiched between two base plates which include electrodes which define a plurality of micro-shutters. A light source illuminates one side of the liquid crystal material. A driving circuit selectively applies driving signals to the electrodes for selectively opening and closing the micro-shutters to allow light from the light source to pass therethrough. A photo-sensitive drum on the other side of the liquid crystal receives the light transmitted through the liquid crystal to form characters. The characters are transmitted to a recording paper. The liquid crystal material, which has an inverted dielectric anisotropy on opposite sides of the critical frequency, is selectively driven by selectively applying two different frequency signals to the liquid crystal.