Abstract: An optical element for laser beam deflection in a raster output scanner (ROS) of an electrophotographic printer. The optical element includes a chamber containing a ferroelectric liquid crystal material having a variable index of refraction as a function of voltage applied thereacross. The ROS includes a control system coupled to a voltage source for applying a voltage across the optical element to control the variable index thereof in conjunction with the rotation of the polygon, facet alignment errors and/or belt motion errors to provide high speed tracking of a light beam.

Abstract: The present invention is directed to a method for fabricating a dual beam semiconductor laser, wherein the laser includes first and second semiconductor laser dies respectively affixed to one another while separated by intervening alignment structures. The alignment structures provide accurate placement of the dual laser beams with respect to one another while also assuring thermal isolation of the laser diodes. The fabrication method employs photolithographic techniques to accurately position the alignment structures across an entire semiconductor wafer, thereby assuring accuracy in alignment of the assembled dual beam lasers. As a result, the need for multiple-step alignment operations commonly employed in the production of multiple diode laser devices is eliminated.

Abstract: The present invention encompasses both a method and an apparatus for fabricating a multiple beam semiconductor laser array, wherein the laser includes a plurality of semiconductor laser dies affixed in a linear fashion to a supporting heatsink. Accurate alignment of the lasers and control of interlaser spacing is achieved through the use of alignment structures formed on the mounting surface of the heatsink. Once assembled, the alignment structures remain in an abutting relationship with the ridge waveguides present on each of the semiconductor lasers. The method not only enables the accurate placement of the laser diodes relative to one another so as to reduce interlaser spacing error, but also eliminates the need for multiple-step alignment operations to produce the multiple diode laser array.

Abstract: The present invention is a method for fabricating a multiple beam semiconductor laser, wherein the laser includes first and second semiconductor laser dies respectively affixed to a pair of supporting heatsinks. The method utilizes a laminating process to accurately position the supporting heatsinks relative to one another yet on opposite sides of an intermediate spacer to form a sandwich-like element. After permanently affixing the sandwich-like element to a base plate, the intermediate spacer is dissolved or otherwise removed to expose the mounting surfaces for the laser dies. The method not only enables the accurate placement of the heatsinks relative to one another so as to reduce the positional error, but also eliminates the need for subsequent multiple-step laser beam alignment operations.

Abstract: A laser system having a light source that transmits a first laser beam and a second laser beam along a first optical path and a second optical path, respectively, is provided. The laser system further includes a waveplate disposed adjacent the light source and the waveplate includes a polarization altering segment and a light transmissive segment, the segments being connected to one another. The polarization altering segment is disposed in the first optical path for altering the polarization of the first laser beam as it passes therethrough, and the light transmissive segment is disposed in the second optical path.

Abstract: A programmable and controllable timing circuit (CTC) is formed on an integrated circuit chip (IC) having a test access port (TAP) with TAP access pins including a TAP data input (TDI) pin, a TAP data output (TDO) pin, a TAP mode select (TMS) pin, and a TAP clock (TCK) pin. The test access port includes a plurality of TAP data registers (TDRs) coupled to receive data signals at the TDI pin and to shift data signals to the TDO pin. A TAP instruction register (TIR) is coupled to receive instruction codes at the TDI pin and to direct use of selected TDRs. A TAP controller is coupled to receive control signals at the TMS pin and clock signals at the TCK pin and provide control and clock signals for controlling operation of the TIR and TDRs. The TAP is provided with a controllable timing circuit design specific TAP data register (CTC/DS/TDR) constructed for receiving a coded CTC digital timing code at the TDI pin.

Abstract: A layered photosensitive imaging member is modified to reduce the effects of interference within the member caused by reflections from coherent light incident on a base ground plane. The modification described is to form the ground plane surface by an electroforming process which leaves the surface with a black finish. Light incident on the ground plane is absorbed, eliminating the reflections which contribute to the interference effect at the imaging member surface.

Abstract: A fully electronic, nonmechanical raster output scanner (ROS) digital printer for high resolution xerographic printing is enabled by combining a laser adapted to produce a variable wavelength output with a dispersive element such as a grating to present a raster scan at an image plane. In a preferred embodiment, a diode laser is positioned within a laser cavity whose length is designed as a function of the resolution required for the scanned image. The wavelength varying output is incident upon a high resolution grating which diffracts the radiation through a diffraction angle which varies according to the wavelength of the incident light. A scan lens is positioned between the grating and a photoreceptor surface to provide focusing and scan linearity correction to the scan line.

Abstract: A monolithic integrated master oscillator power amplifier is provided comprising means for generating and emitting a laser beam and means for amplifying the laser beam. The amplifying means is in communication with the generating and emitting means, and the amplifying means has a region in which the laser beam can expand freely prior to being outputted from the amplifying means. The means for generating and emitting and the amplifying means are coupled to each other by means for selectively controlling the laser beam as the laser beam is communicated from the generating and emitting means to the amplifying means. The means for generating and emitting and the controlling means are in communication with means for supplying pumping current independently to each of the generating and emitting means and the controlling means.

Abstract: A holographic display includes "segmented" images configured as if positioned in separate viewing "cells" corresponding spatially to preselected subareas of a desired display area with invisible segmenting cell sides. In one embodiment, a polarized conjugate reference light source projects the segmented hologram images form a light-transmissive recording medium into the display area, a multi-element nematic 90.degree. twisted shutter assembly changes the polarization of light emanating from subareas corresponding to the images to be blocked while keeping unchanged the polarization of the segmented images to be displayed, and a sheet polarizer positioned between the multi-element shutter and the viewer blocks from view images from those subareas which the polarization direction has been changed by the multi-element shutter. In other embodiments, light-reflective recording mediums and multi-element nematic shutters having an appropriate guest-host dyes are used.

Abstract: A layered photosensitive imaging member is modified to reduce the effects of interference within the member caused by reflections from coherent light incident on a base ground plane. The modification described is to form the ground plane surface with a rough surface morphology by an electroforming process which leaves the surface with a matte-like finish. Light reflected from the ground plane formed with the matte finish is diffused through the bulk of the photosensitive layer breaking up the interference fringe patterns which are otherwise later manifested as a plywood pattern on output prints made from the exposed sensitive medium.

Abstract: A layered photosensitive imaging member is modified to reduce the effects of interference within the member caused by reflections from coherent light incident on a base ground plane. The modification described is to form the ground plane of a low-reflecting material such as tin oxide or indium tin oxide. An additional feature is to add absorbing materials to the dielectric material upon which the ground plane is formed to absorb secondary reflections from the anti-curl back coating layer air interface.

Abstract: A variable attenuator for controlling scanning beam intensity having a twisted nematic liquid crystal for rotating the beam, a polarization analyzer for detecting the degree of alteration in the polarization of the beam by the crystal comprising a polarizing beam splitting plate separating the beam into primary and secondary beams, a photocell providing a signal reflecting the intensity of the secondary beam, a control for adjusting power to the crystal in response to the signal, a glass plate at an angle of incidence equal to but opposite from that of the beam splitting plate for correcting aberrations to the primary beam, and an anti-reflective coating on the optical surfaces of the crystal.In a second embodiment, the plates are replaced by a polarizing cube. In a third embodiment, to obviate fluctuations in the attenuator output, the glass plate instead serves as the source of the beam component to the photocell.

Abstract: A holographic display module is incorporated into a machine with independently operating subsystems, and used to provide an indication of the status or location of the machine subsystems. In one embodiment, a xerographic copier incorporates a holographic display incorporating an outline of the machine. A liquid crystal panel is aligned with the holographic display and selectively addressed in conjunction with signals from the copier subsystems. An illumination subsystem is optimized to provide diffuse illumination of the display.

Abstract: A voltage sensing device having a liquid crystal cell electrically connected to a charged surface and having a light transmissivity varying with applied voltage. A light source is directed through the liquid crystal cell, and a light detector, detects changes in the intensity of light directed through the cell and providing an output indicative of variations in voltage on the charged surface. Polarizers, which polarize light from the light source directed through the liquid crystal cell, and analyze light exiting the cell, convert electro-optically induced phase changes into intensity changes. A saturation level biasing voltage is periodically applied to the liquid crystal cell to set the cell to a reference level, clearing the cell of transient polarization effects. A second reference liquid crystal cell may be provided, electrically coupled to a reference voltage.

Abstract: A holographic disc for use in a spot scanning system is formed with diffractive gratings having optical power incorporated therein, thereby eliminating the need for an f-theta lens between the disc and the scanning plane. The disc is formed by rotating it at high speeds to achieve gyroscopic stability and then exposing a recording medium to short pulse superimposed wavefronts, one of which imparts optical power to the grating being formed. The gyroscopic stabilization insures that each grating is located exactly the same radial distance from the disc axis.

Abstract: A seat assembly is provided for an elongated horizontal transverse bench seat of a fishing boat and is mounted from the bench seat for shifting therealong substantially the full length of the bench seat and for swinging relative to the bench seat between an operative position overlying and supported from the bench seat and an inoperative position swung upwardly away from, outwardly from one side of the bench seat and then downwardly toward the associated boat bottom.

Abstract: A process of recovering asbestos fibre from asbestos-bearing material comprising a first stage of preparing a fibre concentrate by the steps of comminution, classification and spiral concentration and a second stage of liberating and recovering fibre, wherein in the second stage there is a separation by means of a hydrocyclone into a well-opened fraction and a poorly opened fraction, and wherein the asbestos-bearing material is substantially moist throughout the process.