Abstract: An electromechanical cutting stylus is used in a system for mastering video disc recordings in a metal substrate. The cutting stylus introduces signal distortions and errors into the mastering process such that the quality of the reproduced signal displayed on a television receiver is affected. A non-linear optical system, i.e., a Michelson interferometer, is incorporated to measure the non-linearities introduced by the recording process. The non-linear effects of the optical measuring system may be eliminated or reduced by choosing cardinal operating points for measuring the recording non-linearities.

Abstract: In accordance with the present disclosure recorded metallic recording substrates made of a relatively soft metal are coated with a conformal 200 to 400 angstroms thick layer of chromium, chromium oxide, or a mixture thereof, and then preferably passivated prior to being used as matrixes in the replication process.

Abstract: A flaw detection system optically detects defects on the surface of a grooved video disc surface. A beam of light incident on the surface being inspected is reflected thereby into a series of diffraction order cones. A cylindrical lens converges the higher diffraction order cones onto a split photodetector. When the light beam which scans the disc surface passes over a surface defect, such as a hillock, the reflected beam is deflected first to one photosensitive surface of the split photodetector and then to the other, thus providing an output from the photodetector to indicate the presence of such a defect.

Abstract: Recovery from a record of data recorded in an elongated information track, comprising undulations representative of the data is effected by an optical playback system. In the system, the data is recorded within two substantially different frequency bands. The optical playback system has a dual response characteristic to provide improved response at the two different frequency bands. A modifying means interposed in the light beam path shapes the light beam to effect this dual response characteristic (i.e., two different bandwidth responses).

Abstract: Apparatus provides an incident light beam which illuminates the surface of a grooved disc, having signal elements recorded therein in the form of a succession of spaced apart depressions, with a light spot that spans a plurality of convolutions of the groove. The structure of the groove convolutions and signal elements forms a two-dimensional diffraction grating which reflects light into a plurality of diffraction order beams. Photodetectors, respectively positioned to intercept several of the reflected beams provide outputs corresponding to the light power in the respective reflected beams. Estimations of signal element depth in the region illuminated by the light spot may be made from the measured light powers.

Abstract: A technique for positioning a body having a tapered profile when viewed along a first axis comprises exposing the body to a first beam of light oriented along the first axis in a manner such that the tapered profile is projected as a first image onto a first linear array of photodectors disposed along a direction orthogonal to both the first axis and the direction of the taper. The body is exposed to a second beam of light oriented along a second axis orthogonal to the first axis in a manner such that a second profile of the body is projected as a second image onto a second linear array of photodetectors disposed along a direction parallel to the first axis. The body is then moved along the first and the second axes until the first and the second images strike predetermined locations along the first and second photodetector arrays.

Abstract: A method of producing an information storage disc by optical techniques includes the steps of coating a flat, reflective disc surface with a thin coating of radiant energy sensitive material, moving the coated disc relative to a coherent light beam, which is intensity modulated with the information to be recorded, to expose the radiant energy sensitive material, and developing the radiant energy sensitive material to form a track having geometric variations in the disc representative of the modulated information signals.

Abstract: The beam intensity of an optical recording system employed for recording frequency modulated composite video signals on discs undergoes temporal distortion at critical signal frequencies in a manner complementary to the effects of frequency distortion in the spatial frequency response of the recording system. Concomitant recording of the composite signal and a groove effects a practical elimination of signal track drop which results when recording is effected on pre-grooves discs, and additionally eliminates frequency response distortions in the recorded signal due to the optical recording system.

Abstract: Groove depth estimation apparatus provides an incident light beam which illuminates the surface of a grooved disc with a light spot that spans a plurality of convolutions of the groove. The structure of the groove convolutions serves as a diffraction grating which reflects the incident light beam into a plurality of diverging beams of light. A photodetector provides measurements of the light power in the respective reflected beams. Calculator circuits are provided for deriving from the photodetector measurements estimation of the average groove depth in the region illuminated by the light spot.

Abstract: An optical scanner is disclosed for scanning a three-dimensional object or a two-dimensional document located in a space which is open and exposed to ambient light. Light from a laser is directed through a beam splitter and a deflector to the object or document, from which it is reflected back through the deflector, and from the beam splitter through a narrow-band optical interference filter to a photodetector. The laser light is modulated at a carrier frequency rate, and the electrical signal from the photodetector is demodulated to produce a video signal free of disturbances due to ambient light.

Abstract: Defect detection apparatus, for optically inspecting a spiral groove of a video disc record, directs a coherent light beam at the grooved surface of the disc. The incident beam, focused at a point beyond the disc surface, illuminates the grooved surface with a light spot that spans a plurality of convolutions of the groove. Relative motion is established between the disc surface and the incident beam in a manner causing the illuminating spot to rapidly scan the groove surfaces in a coarse spiral pattern. The structure of the illuminated groove convolutions, absent any defects, serves as a diffraction grating for diffracting the light into an undeviated zero diffraction order cone of light that converges at a first location in a plane spaced from the disc surface and into deviated higher diffraction order cones of light that converge at additional locations in said plane separated from the first location.

Abstract: A gas laser tube has a spherical reflector at one end and a flat mirror at the other end. An acoustooptic modulator is attached to the flat mirror. The modulator is positioned so that the generated acoustic wave intersects the laser beam at the Bragg angle.

Abstract: The light wave energy of a scanning, intensity-modulated light beam used to provide an optical display or recording of a given scene at a receiving station is the same light wave energy initially employed to optically communicate video information pertaining to this given scene between a transmitting station and the receiving station.

Abstract: A flying spot scanner is disclosed for scanning an object document or scene with a spot of light, and producing an electrical video signal representing the object. The scanner can be operated under normal ambient light conditions without a light-shielding enclosure. A light beam is deflected in repetitive scanning fashion over the object. The light beam is modulated in amplitude (intensity) at a radio frequency f.sub.c such as 1.2 MHz. A photodetector is positioned to receive light from the object, and it produces an unwanted electrical ambient light noise signal having a maximum frequency f.sub.a, and an electrical information signal consisting of a carrier at frequency f.sub.c modulated by a video signal having a maximum frequency f.sub.m, where f.sub.c - f.sub.m is larger than f.sub.a. The information signal is separated from the ambient light noise signal by a filter, and the information signal is demodulated to produce a facsimile or video information signal free of noise due to ambient light.

Abstract: An electrochromic display device includes an electrolyte and at least one transparent electrically conductive electrode. An organic insulating layer e.g. a photoresist material, is disposed between the transparent electrode and the electrolyte such that no portion of the transparent electrode is in contact with the electrolyte. The insulating layer protects the transparent electrode from deterioration so as to increase the lifetime of the transparent electrode.