Abstract: A focus control system for an optical record carrier in which a light beam is reflected by a movable mirror through one objective lens and then directed to the carrier through another objective lens so that the light beam remains focused on the record carrier in spite of fluctuations of the carrier.
Abstract: A recording and/or reproducing apparatus for a tape type optical recording medium has a transparent guide on which guide tracks are precisely formed. A scanning beam is controlled so as to scan along the guide tracks and is converged on the recording surface of the tape type recording medium. The accuracy of the recording tracks on the tape is equivalent to that of the guide tracks. In this way, recording tracks can be precisely formed on the tape witout the step required in the prior art methods of pre-forming guide tracks on the recording medium.
Abstract: A novel electron beam addressible recording device is disclosed, in which a recording layer formed of ferroelectric material having secondary electron emissivity .delta. greater than 1 is provided in a vacuum chamber. One surface of the recording layer is applied with a predetermined potential and the other surface is caused to have different potentials from the predetermined potential by scanning it with an electron beam. The difference of the potentials between two surfaces of the recording layer, causes poling patterns corresponding to the data recorded to be formed. The recorded data in the form of poling direction can be detected by electron beam scanning.
Abstract: In a cathode ray tube of the single-gun, plural-beam type in which the plurality of beams are made to intersect each other substantially at the optical center of a main focusing lens, any disparity in the focusing effects imparted to the respective beams by the main focusing lens and any auxiliary lens is corrected by applying suitably different biasing voltages to the cathodes emitting the respective beams so that the beams are subjected to different accelerations and travel through the lens fields at different speeds. Thus, the focusing effects of the lens fields on the respective beams are varied to cause the beams to be precisely focused on the screen. The cathode and control grid electrodes are physically arranged to permit control of the individual beam currents for proper color balance.
Abstract: An image display apparatus having light beam sources for generating light beams, an optical modulator for modulating the light beams by image signals to be projected, a deflection device for deflecting the modulated light beams, the deflection device including a polygon mirror and an auxiliary reflection mirror provided near the polygon mirror such that the modulated light beams are reflected from the polygon mirror to said auxiliary reflection means and back toward the polygon mirror, a device for supplying the modulated light beams to the polygon mirror with predetermined angles relative to a rotational plane of the polygon mirror, such that the modulated light beams incident upon the polygon miror are reflected a plurality of times by the polygon mirror, and a projection device for projecting the modulated and deflected light beams from the deflection device on a screen or the like.
Abstract: A direct viewing picture image display apparatus displays a good picture image with a small amount of light and low power consumption using a laser beam without producing speckle noises. The display apparatus comprises a light source for emitting a laser beam, an optical modulating system for optically modulating the laser beam from the light source in response to a video signal, a scanning system for horizontally and vertically scanning the modulated laser beam from the scanning signal in response to a scanning signal, and a projecting optical system for projecting the scanned laser beam from the scanning system to form an image of the laser beam on the retina of an eye of an observer. Depth information is provided to the laser beam at a suitable stage after optical modulation by the optical modulating system so that a stereoscopic image is displayed.
August 16, 1991
Date of Patent:
October 11, 1994
Koji Ashizaki, Masanobu Yamamoto, Senri Miyaoka, Sakuya Tamada
Abstract: A beam index type color television receiver having a beam index type color cathode ray tube which includes a screen having a plurality of groups of color phosphor elements and index phosphor elements, an index signal sensing device for detecting index signals from the index phosphor elements and generating index pulses, a frequency multiplier for providing a timing signal with a frequency that is a multiple of the frequency of the index pulses, a gate signal generator supplied with the timing signal from the frequency multiplier and generating a plurality of gate signals, a gate circuit for sequentially selecting, response to the gate signals three primary color signals desired from an input video signal and supplying the selected primary color signals to the cathode ray tube, and a velocity modulating device for modulating the beam scanning velocity of the cathode ray tube.
Abstract: A light beam scanning system having an automatic focus correction, comprises a flat carrier having first and second oppositely facing reflective surfaces at least one of which has variations defining a recorded signal, first and second lens assemblies positioned against the first and second reflective surfaces, respectively, an optical assembly providing a light beam path between the first and second lens assemblies and a light source. A light beam emitted from the light source is guided to the first reflective surface of the carrier through the first lens assembly and reflected from such first surface and passed through the first lens assembly, along the optical path between the first and second lens assemblies and through the second lens assembly. The first and second lens assemblies are arranged so that their respective image magnifications or magnification factors satisfy a specific interrelation, thereby to establish the autofocusing of the light beam at the second reflective surface.
Abstract: In a video signal reproducing device having a cathode ray tube in which at least one electron beam is focused at a phosphor screen and is made to scan the screen in line-scanning and vertical directions, and in which the beam focusing is effected by an electron lens constituted by at least two tubular electrodes arranged coaxially in succession along the axis of the tube with a relatively low potential being applied to one of the electrodes and a relatively high potential being applied to the other electrode or electrodes; electron beam scanning velocity modulation is effected by forming the tubular electrode to which the low potential is applied in two parts which are axially separated along a vertical plane inclined relative to the tube axis, and by applying across the two parts of such tubular electrode a control signal which is produced in response to transient changes in the luminance or brightness of the video signal being reproduced.
Abstract: In a signal play-back device having a substantially flat record carrier or disc provided with first and second oppositely facing reflective surfaces and a signal recorded as variations in at least the second surface, and an optical system in which a first lens directs a laser light beam against the first record carrier surface for reflection by the latter and passage back through the first lens for focussing by the latter at an image point remote from the first record carrier surface, and a second lens effects a predetermined focussing of such image point at the second record carrier surface for scanning the recorded signal variations, with the light beam reflected from the latter, and having corresponding variations in its beam energy, passing back through the second lens toward a light detector for providing an output corresponding to such variations in beam energy, and in which the first and second lenses have magnification factors for maintaining the predetermined focussing of the image point at the secon
Abstract: A color cathode ray tube preferably of the single gun, plural beam type wherein the beams originate on a horizontal or vertical straight line and are directed into a field produced by a horizontal-vertical electromagnetic deflection yoke at predetermined incident angles to each other so as to converge at a color screen, is provided with a magnetic yoke, for example, secured to the electron beam convergence plates at the end of the electron gun so as to be disposed in the path of the leakage flux produced by the horizontal-vertical electromagnetic deflection yoke, and thereby impart a further vertical or horizontal deflection field to at least one of the plural beams for correcting a deviation between the positions of rasters on the color screen produced by the plural beams.