Abstract: A liquid crystal light valve projector assembly is disclosed here including (1) a multi dashed layered liquid crystal light valve having a light-writing side and a light projecting side, (2) light-writing means for producing modulated writing light representative of a given image, which writing light when written onto the light-writing side of said light valve causes the latter to modulate in a corresponding manner, and (3) light projecting means cooperating with the light-projecting side of said light valve for projecting a correspondingly modulated projection light beam onto a projection plane for visually displaying the given image.

Abstract: A high-efficiency optical system for use in a liquid-crystal light-valve video projector. High intensity, unpolarized white light is separated into primary color components by color-selective filters transmitting light containing both first and second polarization states. Light of each primary color is characterized by a wavelength passband whereby the endpoints of the passband are defined by first and second wavelengths. The second passband endpoint of the first polarization state of the first primary color overlaps the first passband endpoint of the second polarization state of the second primary color, and the second passband endpoint of the second polarization state of the second primary color overlaps the first passband endpoint of the first polarization state of the third primary color. In addition, the video projector design utilizes low f/# optics in conjunction with absorptive polarizers to remove residual light of an unwanted polarization state allowed into the system by the low f/# optics.

Abstract: A high-efficiency optical system for use in a liquid-crystal light-valve video projector. High intensity, unpolarized white light is separated into primary color components by color-selective filters transmitting light containing both first and second polarization states. Light of each primary color is characterized by a wavelength passband whereby the endpoints of the passband are defined by first and second wavelengths. The second passband endpoint of the first polarization state of the first primary color overlaps the first passband endpoint of the second polarization state of the second primary color, and the second passband endpoint of the second polarization state of the second primary color overlaps the first passband endpoint of the first polarization state of the third primary color. In addition, the video projector design utilizes low f/# optics in conjunction with absorptive polarizers to remove residual light of an unwanted polarization state allowed into the system by the low f/# optics.

Abstract: A liquid crystal light valve, comprising a layer of liquid crystal for storing image information and a photoconductor aligned with the liquid crystal and positioned in closed proximity thereto for effecting an electric field applied across the liquid crystal. Apparatus is provided for simultaneously applying an electric field across the liquid crystal and photoconductor while impinging optical image information on the photoconductor, the photoconductor and applied field combining to produce a modified electric field across the liquid crystal which impresses the image information on the photoconductor into the liquid crystal.

Abstract: A hard copy such as a printed wiring board is fabricated by exposing to radiation a liquid crystal cell in which a desired pattern is written and directing the pattern-carrying radiation projected from the cell by transmission or reflection to a substrate which is coated with a material sensitive to the radiation and disposed alignedly at an exposure position by optical registration. The duration of the exposure is controlled for a given light intensity and for the type of the coating material. A pattern may be written in one cell substantially simultaneously as another cell is used for the projection imaging. After a produced pattern is compared with a reference pattern, corrections may be effected through a processor which controls the writing of a pattern in a cell.

Abstract: An optical system having a projection lens for imaging a scattering type thermo optic cell on an image receiving surface, comprising optical source apparatus for generating an optical beam and an image created on the scattering type thermo optic cell having a minimum feature size, the optical beam propagating through the object on the scattering type thermo optic cell. Also provided is a condenser system which illuminates the scattering cell and underfills the aperture of the projection lens, thereby creating a partially coherent imaging system. As a result, a relatively higher contrast ratio for the minimum features of the image is obtained at the image receiving surface.

Abstract: An apparatus for correcting deviations in image linewidth in a image projection system having a laser and a liquid crystal cell wherein images are made on the liquid crystal cell by impinging the laser on said cell. The apparatus also has apparatus for creating a test image having a plurality of lines of specific width on a liquid crystal cell and calculating the difference between the linewidth of the plurality of lines of said test image as created and as expected. Furthermore, apparatus are provided for modifying the period of the laser light based on said differences in linewidth between the plurality of lines (as created and as expected) to correct deviations in image linewidth, whereby deviations in image linewidth are substantially eliminated.

Abstract: An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the images and direct the light on a projection surface with the plurality of reflected images in coregistration.

Abstract: An improved light addressed liquid crystal light valve incorporating electrically insulating light blocking material is disclosed. The light valve has a hydrogenated amorphous silicon photosensitive layer and a germanium containing or tin containing alloy film as a light blocking layer. The light blocking layer that may be used is a selected alloy which includes one or more elements from the group consisting of germanium and tin, one or more elements from the group consisting of hydrogen, nitrogen and oxygen, and zero or more elements from the group consisting of silicon and carbon. The light blocking layer has an optical density per unit thickness approximately equal to or greater than 3 OD/micron for visible light and a sheet resistivity approximately equal to or greater than 10.sup.10 ohms/square.

Abstract: A spatial light modulator is disclosed with a first lens array disposed adjacent to a matrix of light modulators, and in proximity to a liquid crystal light valve containing a photoconductive element. Low intensity light is collimated by a lens element to illuminate an optical aperture which has geometric configuration similar to that of the matrix element. The first lens array focuses light from the illuminated aperture into the pupil of a matrix addressed spatial light modulator element. The second lens array collects light emitting from the light modulator element, and focuses the image of the aperture onto the photoconductive element of the liquid crystal light valve so as to preserve the geometrical and positional configuration of the optical aperture, and magnify the size of the illuminated region on the photoconductor. The design of the optics is such that when adjacent apertures are imaged onto the photoconductor, the proximate boundaries of the illuminated regions are contiguous.

Abstract: An apparatus for a liquid crystal image projection system having a liquid crystal cell, including optical apparatus for inducing a uniform texture of scattering centers in a liquid crystal cell by impinging a pulse of optical energy on the liquid crystal cell, thereby the optical energy is absorbed and converted to thermal energy heating the liquid cyrstal to a second temperture, the end of the pulse bringing about a cooling which causes the liquid crystal centers within the liquid crystal cells to scatter in a uniform texture.

Abstract: An optical system is disclosed which combines a collimating lens with a half wave plate, a polarizing beam splitter, and imaging optics to create a polarized image of a non-polarized light source. This optical system has significant benefits of energy efficiency and brightness.

Abstract: An active matrix liquid crystal light valve is disclosed. The addressing matrix has an array of electrodes to create electric fields across the liquid crystal layer. The light valve has a continuous nonconductive reflector layer, separate and distinct from the electrode array of the active matrix. This light valve has a leveling layer disposed on the active matrix to form a planar surface. The reflector layer is formed as a continuous sheet on the planar surface of the leveling layer. An additional invention is the use of fringing fields to switch substantially all of the liquid crystal, including areas not directly over the electrodes.

Abstract: A light scattering liquid crystal transducer in which the degree of light scattering is controlled by impressing an electric field across the cell during and immediately after the application of a high-energy short duration thermal pulse applied to the entire viewed region of the cell. This allows full gray scale to be achieved as a function of applied voltage.

Abstract: An apparatus for correcting deviations in image linewidth in a image projection system having a laser and a liquid crystal cell wherein images are made on the liquid cyrstal cell by impinging the laser on said cell. The apparatus also has apparatus for creating a test image having a plurality of lines of specific width on a liquid crystal cell and calculating the difference between the linewidth of the plurality of lines of said test image as created and as expected. Furthermore, apparatus are provided for modifying the period of the laser light based on said difference in linewidth between the plurality of lines (as created and as expected) to correct deviations in image linewidth, whereby deviations in image linewidth are substantially eliminated.

Abstract: An image projection apparatus in which an image object plane contains a plurality of reflecting images and a light source and optical system projects a beam on each of said plurality of images. Spaced projection lenses are positioned to receive the light reflected from the image and direct the light on a projection surface with the plurality of reflected images in coregistration.

Abstract: A mirror is mounted to a rotatable shaft by means of an adapter with a tubular end section and a slot at the other end. An end of the shaft is inserted into this tubular section an a protruding part of the mirror is centrally inserted in the slot. The external surface of the tubular section is tapered which matches the tapered inner surface of a clamp ring disposed around the adapter. By pressing the clamp ring longitudinally, the tubular section of the adapter becomes fastened around the shaft.

Abstract: A liquid crystal cell for an image projection apparatus has a liquid crystal layer sandwiched between two conductive layers. The layer surface is divided into one or more regions and one of the sandwiching conductive layers is divided into separate sections each matching a different region. Busbars are bonded on the other of these conductive layers along the edges and boundary lines between adjacent regions (resistors) such that negative and positive writing/erasing can be performed in selected region or regions. By applying one or more current pulses in one or more of these resistors, the corresponding region or regions can be more completely erased and a uniform dark background can be created therein.

Abstract: Operating temperature of a liquid crystal cell is controlled by passing heated air on its surface, the heater for the air being operated according to the average temperature of the cell measured by a sensor. Fine control is effected by means of resistive heaters affixed on the exterior surface and by electrodes provided at strategic locations inside to pass current through a conductive layer.

Abstract: The position and motion of a rotating element is determined by using a two-grating moire pattern. Movement of the element causes a projected scale image representing radiation reflected from the element to shift relative to a fixed grating thereby generating moire fringes. The accumulated fringes serve to measure absolute position and motion of the element.