Abstract: A sheet removal apparatus for unloading a sheet from a hollow drum mounted for rotation about its axis and having a vacuum provided to the interior thereof and to first and second sets of vacuum openings through the surface of the drum. The sheet is arranged to overlie and close the first set of vacuum openings with the second set of openings extending substantially parallel with an edge of the sheet and comprising only a small portion of the total number of vacuum openings through the drum. An exit blade is disposed adjacent the drum and has an edge proximate the drum that extends substantially parallel to the edge of the sheet and forms an acute angle with the drum surface with the proximate edge of the blade closely adjacent the apex of the angle and parallel with the edge of the sheet. When the drum is rotated to a sheet removal position, the first set of vacuum openings lies beneath the acute angle when the edge of the sheet is disposed on the opposite side of the apex.

Abstract: A tile-oriented technique and associated apparatus for manipulating a continuous tone (contone) image through image rotation, anamorphic scaling and digital halftone screening for use in illustratively implementing a page description language. Specifically, an incoming contone image is first partitioned into aligned non-abutting tiles. Overlapping blocks are then defined which will hold output data for corresponding tiles. To effect rotation and anamorphic scaling of the contone image, two-dimensional sampling increments, in fast and slow scan directions, are defined to relate movement between successive pixels in an output block to movement between corresponding pixels in the contone image. Similar, though independent, sampling increments, based in part upon screen angle and screen ruling, are defined for movement between successive pixels in a halftone reference cell. Incremental sampling occurs in the contone image to yield a corresponding sampled contone value.

Abstract: In an imaging apparatus utilizing a rotating carrier member arranged to carry a writing element, a source of light is provided which is movable with respect to the writing element to project a writing beam of light onto the writing element to generate an image. The source of light comprises a plurality of laser diodes and a plurality of optical fibers connecting the diodes to a movable writing head adjacent the carrier member, with the optical fibers in the writing head have output ends arranged in a linear array. The improvement comprises a substantially planar support substrate disposed in the writing head arranged to support the output ends of the optical fibers on a first surface thereof. The substrate is provided with a plurality of grooves on the first surface with each groove receiving the output end of an individual fiber.

Abstract: Laser apparatus is described in which the optical cavity of a laser oscillator is specially provided with a polarizing device which has on its outer face a partially reflecting coating (such as a thin partially reflecting layer of low-loss dielectric material). The polarizing device serves both as an output coupler for narrow linewidth laser emission from the optical cavity and also as a means for substantially suppressing amplified spontaneous emission (ASE). A multiple-prism Littrow-mounted grating (MPL) dye laser apparatus embodying the invention achieves a laser linewidth of less than about 0.1 GHz (.DELTA..nu.), a ratio of intensity I of the ASE to the intensity I.sub..lambda. of the desired laser emission of about 10.sup.-10, an efficiency of somewhat more than 10%, and a short optical cavity length of less than 10 cm. The apparatus is also more rugged, more stable in frequency with changes in temperature, and less costly than similar previous lasers.

Abstract: A beam scanning galvanometer is disclosed which oscillates a mirror in a non-resonant mode. The moving parts of the galvanometer are made with as small a moment of inertia as possible because the mirror is oscillated in a non-resonant mode. The galvanometer uses two sets of crossed leaf-springs to support the mirror instead of bearings which are usually used in non-resonant galvanometers. Each of the sets of leaf-springs is formed of a single strip of cold rolled stainless steel. The springs are embedded in uniquely shaped cavities in a permanent magnet that supports the mirror at a distance very close to an axis of rotation of the mirror. The mirror is specially shaped with beveled edges so that its moment of inertia is low and so that it can oscillate in very close proximity to a driving current coil which surrounds the mirror supporting magnet. A magnetic position sensor is used to detect as angular position of the mirror during operation of the galvanometer.

Abstract: Apparatus is disclosed for recording and reading a color image formed on a receiving medium such as a film coated with a blue metastable colloidal silver. Upon application of heat to selected areas of the coating, the blue silver turns yellow to form an image. In a record mode, a modulated beam from a diode laser is scanned onto the receiving medium to form an image. In a read mode, a diode laser beam containing two different wavelengths of radiation is scanned across an image on the recording medium. In order to detect errors in the image, a detector senses the two wavelengths at each pixel and produces signals indicative of the densities of the yellow and blue in the pixel. Signal processing means is adapted to determine valid data points from the two signals.

Abstract: A thermal printer is disclosed which is adapted to form an image on a thermal print medium of a type in which a donor element transfers dye to a receiver element upon receipt of a sufficient amount of thermal energy. The printer includes a plurality of diode lasers which can be individually modulated to supply energy to selected dots on the medium in accordance with an information signal. In order to increase the efficiency and versatility of the printer, the print head of the printer includes a fiber optic array having a plurality of optical fibers coupled to the diode lasers. The thermal print medium is supported on a rotatable drum, and the fiber optic array is movable relative to the drum.

Abstract: A thermal printer is disclosed which is adapted to form an image on a thermal print medium of a type in which a donor element transfers dye to a receiver element upon receipt of a sufficient amount of thermal energy. The printer includes a plurality of diode lasers which can be individually modulated to supply energy to selected dots on the medium in accordance with an information signal. The print head of the printer includes a fiber optic array having a plurality of optical fibers coupled to the diode lasers. The thermal print medium is supported on a rotatable drum, and the fiber optic array is movable relative to the drum. In order to prevent banding in an image produced on the print medium, the two outside fibers in the array are used for preheating and postheating of inner scan lines.

Abstract: A dual port, dual speed image memory interface is capable of controllably inputting or outputting medium speed serial data through a medium speed port at the same time that high speed serial imagery data is being supplied to or read from a high speed data rate port. Access to the medium speed port is through a mux/demux unit, which is coupled to receive imagery data at the medium data rate and controllably writes successive data signals, in parallel, into respective ones of a set of plural memory units, and controllably reads out data from the parallel-connected memory units and assembles the accessed data in the form of a serial output digital data stream for transmission to a requesting destination device signals at the medium data rate.

Abstract: An illumination system for a film scanner is disclosed which comprises a light source and optics for providing a line of light on a film. Light transmitted through the film is imaged onto photosensor elements such as CCD arrays. In order to obtain a high quality electronic image from various types of film, an integrating cylinder is used to provide a line of diffuse light on the film, and light delivered to the integrating cylinder is controlled in accordance with the particular type of film being scanned and the operating conditions of the apparatus.

Abstract: A method of contact printing comprising the steps of supporting a film and an original in superposed relationship. A vacuum is progressively applied to the superposed film and original from a first edge to an opposite edge thereof to hold them in substantially intimate contact while simultaneously moving a source of collimated light over the surface of the superposed film and original and exposing the film through the cover sheet and the original.

Abstract: In an imaging apparatus utilizing a carriage member arranged to carry a writing element, the carriage member and the writing element each have at least one surface with at least one of the surfaces having a discontinuity therein. A light beam is movable with respect to the writing element and is projectable thereon to generate an image. A light beam focusing system is provided for focusing the light beam with respect to the writing element and includes an element for sensing at least one of the surfaces of the writing member and the carriage member to control the focusing means. A discontinuity indicator is provided to indicate when the discontinuity in the surface is proximate the surface sensor, and an inhibitor is responsive to the indicating means to inhibit the output of the surface sensor when the discontinuity is within its range to prevent the focusing system from focusing on the discontinuity.

Abstract: In an imaging apparatus comprising a rotating carrier member arranged to carry a writing element, with the carrier member having an axially extending indicia on the surface thereof, light producing means is provided which is movable with respect to the writing element and is projectable thereon to generate an image. The light producing means is arranged as a linear array in a housing member, with the housing member having an axis disposed substantially perpendicular to the axis of the carrier member. Means is provided for selectively angularly positioning the housing member and the linear array with respect to the carrier member. The positioning means comprises light sensing means disposed on opposite sides of the axis of the housing member in a predetermined relationship with respect to the linear array and facing the carrier member.

Abstract: An electric motor is disclosed which is of the brushless D.C. type and comprises a generally planar rotor and a generally planar stator. The rotor is a multipolar permanent magnet, and the stator includes a planar coil having a plurality of windings. In order to provide a motor which can supply a high torque at a relatively low speed and a low torque at a high speed, the stator includes a low speed coil which includes a large number of windings of fine wire and a high speed coil which includes a smaller number of windings of coarse wire.

Abstract: A focusing lens assembly comprises a magnetic support member carrying a first lens, with a magnetic flange extending outwardly therefrom. A nonmagnetic axial spacer connects the first flange to a second nonmagnetic flange which supports a second, movable lens. Sheet flexure members are provided for supporting the second lens within a central opening in the second flange coaxially of the first lens and axially spaced from the end of the support member for substantially only axial movement of the second lens with respect to the first lens. A drive bobbin is provided for moving the second lens axially having a portion which circumscribes the end of the support member in a non-contacting relationship therewith.

Abstract: A housing for an automated data library which is a substantially rigid lightweight structure providing accurate location of the components therein. The housing structure comprises a plurality of longitudinally extending members disposed about and parallel to the central transfer shaftway and the storage bay areas, with at least one of the longitudinally extending members being formed as a rigid tubular member and the remaining longitudinally extending members being generally channel-shaped and disposed at the corners of the housing parallel with the shaftway and adjacent the open bay areas. A pair of closure plates are connected to and close the ends of the longitudinally extending members. A plurality of gusset plates join the adjacent ends of the longitudinally extending members and the periphery of the closure plates and leave a major portion of the shaftway and the bay area accessible between the longitudinally extending members.

Abstract: A method and apparatus for registering a sheet member with an indicia on the surface of a moving member which comprises means for driving a sheet member substantially tangentially of the moving member and between the moving member and a linear image sensor which is disposed adjacent the surface of the moving member. The linear image sensor senses the leading edge of the sheet member and, as the moving member is driven, the linear image sensor senses the passage of the indicia on the surface thereof as the member travels therepast. The distance between the indicia and the leading edge of the sheet member is sensed and an error signal is generated representative of the distance. The sheet member driving means is regulated so as to reduce the error signal and the sheet is attached to the moving member when the error signal is reduced to a predetermined value.

Abstract: In a system for compensating predictable periodic speed variations in the electric motor of a velocity servo, which speed variations may include variations at frequencies above the velocity servo bandwidth, circuitry is provided for generating synchronized reference signal frequency components corresponding in frequency to at least one ripple frequency component of the torque. Each of the synchronized reference signal frequency components is adjusted, while the motor shaft is revolving, in phase and amplitude in a sense to reduce the ripple at that frequency in motor speed. Both manual and self-adjusting embodiments are shown, each including real time spectrum analysis of motor torque to guide the phase and frequency adjustments.

Abstract: In an automated data library comprising a plurality of storage areas each arranged to accept and store a data storage member, a reading device arranged to retrieve data from a data storage member, and carriage means arranged to selectively transfer data storage members between the storage area and the reading device. A lever is disposed along a side of the carriage adjacent the reading and is arranged for movement between a rest portion within the perimeter of the carriage and an extended position whereby the lever engages a data storage member extending from an opening in the reading device to fully insert the member into the device.

Abstract: An automated disk library which provides the necessary rigidity and accuracy of positioning of the transport mechanism with respect to the storage bays and the disk drives without the attendant cost, bulk and weight of the prior art devices. The transport drive and support comprises a carriage member disposed in the shaftway with structure for locating the carriage with respect to an x-axis and a y-axis transverse of the shaftway while permitting motion of the carriage along a z-axis parallel to the shaftway. A plurality of guide surfaces are provided on the portion of the housing adjacent the shaftway with guide rollers rotatably mounted on the carriage and bearing on guide surfaces to locate the carriage with respect to the x- and y-axis.