Abstract: Method and means for supporting an optical read or write head to maintain a constant spacing between the head and a moving information storage medium. A major drawback in the prior art head assemblies incorporating pheumatic forcing pistons concerns the chattering, or lateral and axial vibrations, of the lens assembly relative to the housing due to the turbulent airflow in the passageway leading from the annular chamber to the atmosphere. The present invention provides a lens assembly/housing arrangement in which substantial axial support for the lens assembly within the housing is obtainable simultaneously with eliminating the turbulent air flow by increasing the axial width verses gap width ratio. Basically, the invention involves an annular pressure chamber provided between air journal bearings at each end of the housing.

Abstract: A video record medium, such as a record disc, for recording a composite video and audio signal suitable for stop-motion playback, with accompanying audio. Discrete segments of an analog audio signal are digitized and compressed in time and recorded on alternate tracks on the disc, and corresponding frames of a video signal are recorded on the tracks located therebetween. During playback of the disc, a selected audio track is scanned initially and the digital audio data recovered therefrom is entered into a memory device, after which the track for recording the corresponding video frame is scanned in a repeated fashion, to produce a stop-motion display of the frame, while the stored audio data is extracted from the memory device and converted back to an analog format, for simultaneous playback at its original speed.

Abstract: Method and apparatus for optically recording information on a moving information storage member and for reading the information immediately after it is written. An intensity modulated writing beam and a separate reading beam of light are simultaneously focused by a single objective lens. The reading beam impinges the medium at a point trailing the point of impingement of the writing beam by a prescribed amount. The reading beam is reflected by the moving medium in accordance with the recorded information. The modulated reflected light is collected by the objective lens, and the intensity of the reflected light is sensed for generating a playback signal. The quality of the playback signal may be monitored to allow control of the intensity of the writing beam.

Abstract: A method and apparatus for recording a data signal on a light-reflective record disc, wherein an intensity-modulated write beam of light is focused onto the disc as the disc is rotated in a prescribed fashion, to produce a sequence of spaced non-reflective regions representative of the data signal. Additionally, a relatively low intensity pre-write beam of light scans the disc in advance of, but synchronous with, the write beam to detect the presence of non-reflective defects in the disc that could inhibit the recording of the data signal thereon. Whenever such a defect is detected, a special defect flag code is recorded in advance of and over the defective region, whereby when the data signal is recovered from the disc at a subsequent time, it can be recognized that the data signal is being temporarily interrupted.

Abstract: A method and means for vertical interval encoding of a program signal having at least a video program portion with sequential fields separated by vertical intervals, the program signal having associated therewith sequential field related identification code signals, wherein a desired field related identification code at which encoding of the program signal is to commence is selected. Continuously recurring vertical interval code signals are generated at predetermined intervals corresponding to like intervals between groups of fields, for example two or three, of the program signal. The identification code associated with the program signal is then compared with the selected identification code, and upon the occurrence of a match of identification codes, the composite video program signal is signal-mixed with the vertical interval code signal in timed relationship so as to insert the vertical interval code signal in corresponding vertical intervals of the program signal.

Abstract: Method and apparatus for measuring the spacing between adjacent information tracks on a recording medium. A spot of light is projected onto at least a portion of a first track and maintained in a constant spacing from a second track. A photodetector detects the amount of light reflected off of the disc from the spot in a predetermined direction, and provides an electrical signal as an output. The photodetector output provides a measurement of the track-to-track spacing of the recording medium.

Abstract: A method and means for drying a thin aqueous-based coating on heat sensitive materials without boiling and without distortion or damage to the heat sensitive material or delicate surface thereof. Solvent-based adhesives are used in the production of articles of manufacture because of the ability to assembly the separate pieces immediately after the spray adhesive is applied. However, certain solvent-based adhesives attack the surface of the item to be covered, and in the case of videodiscs, the solvent in the adhesive may well contaminate the plastic surfaces or even the aluminum reflective layer of a laser disc. According to the present invention, a water based coating applied to a sensitive material is subjected to alternate sources of radiant heat energy and relatively cool air.

Abstract: A system for recovering information from a videodisc and performing special functions which enhance the operational character of the system. To increase the reliability of landing at or near a target track, provisions are made to search for a track adjacent a target track whose track identifier has been obliterated. Further, a method and means for stepping forward or reverse one field at a time is disclosed. Another aspect of the invention concerns a capability to respond to a random command instruction resulting in subsequent functioning of the system in a random manner. Yet a further aspect of the invention is related to controlled jumping of one or more tracks during vertical blanking time to produce unique forward or backward motions; multiples of playing speed, both forward and reverse, and visual special effects can be realized using the multiple track jumping feature. Finally, a method and means are described which permit synchronous transmission of video from a videodisc to an external using device.

Abstract: Method and apparatus for the recording onto a recording medium and playback of digital data, such as digitally encoded audio data, such that the recording medium is playable on either of two different commercial television format video type players. For example, according to the present invention an optical disc having digitally encoded audio data recorded thereon may be playable on either a PAL compatible or an NTSC compatible optical video disc player with minimal modification of the player.

Abstract: An apparatus for optically reading a recording medium having information tracks disposed on alternating inclined recording surfaces preferably arranged in separate but alternately interposed spirals inclined at different angles on the medium. The apparatus includes photodetectors for detecting light reflected from each of the tracks, and circuitry for controllably combining the signals from the photodetectors to minimize crosstalk in the recovered signals.

Abstract: Method and means for evaluating the quality of audio and/or video transfer characteristics of a device upon which, or through which, audio and/or video information is contained, or passes, respectively. Both method and apparatus concern the evaluation of the quality of information transfer in the recording and playing back of a recording medium or in the transferring of audio and/or video information through an information handling device referred to as a throughput device. Unit evaluation is accomplished by establishing an input signal of known content, measuring selected parameters of selected parts of the input signal, feeding the input signal to the unit under test, measuring the parameters of parts of the output signal from the unit under test corresponding to the same selected parts of the input signal, and comparing the selected parameters of the input signal with the corresponding parameters of the output signal.

Abstract: An extended play videodisc and a method and apparatus for playing it. The disc carries every m th segment of a video program and the segments are repeated m times to approximate the original program. Prior art extended play discs have contained every other frame or every third frame of video, but the repeating of an entire frame results in poor motion reproduction and flickering scene transitions. The present invention preferably includes the repeating of a field of video an odd number of times. The fields are preferably arranged in order on the disc with n fields per revolution, the disc being rotated such that a new field is read every one and 1/n th revolution of the disc. The new segment is preferably read during the final repeating of the previous segment.

Abstract: A signal conditioning method and apparatus for preconditioning an FM code signal prior to its processing by a limited bandwidth medium such as an audio magnetic recording track. The FM code signal is preconditioned to limit its bandwidth and alter its phase equalization prior to processing by the medium. The phase equalization is altered in a way opposite to the alteration performed subsequently by the limited bandwidth medium, such that the conditioned signal after recovery from the medium has substantially no phase distortion relative to the input signal and no high energy distortion. The invention is particularly useful when an FM code signal is to be mixed with an analog signal and the composite signal is first processed by a limited bandwidth medium and is then processed by a further analog medium, such as an FM modulator.

Abstract: A method and apparatus for selectably retrieving information from any of a plurality of spirally-formed information tracks formed in a video disc by means of controlling a carriage for translating the video disc in a forward or a reverse direction relative to radiant beam information recovery means in a video disc player. Each information track is identified by a unique address and means are provided for selecting the address of a particular track to be retrieved. A prescribed sequence of drive signals is applied to a carriage motor dependent on the distance to be traveled by the carriage to retrieve the selected information, the drive signals being successively stepped downward to intermittently redetermine carriage motor speed as predetermined location thresholds are reached during carriage translation.

Abstract: Method and apparatus for measuring the spacing between adjacent information tracks on a recording medium. A spot of light is projected onto at least a portion of a first track and maintained in a constant spacing from a second track. A photodetector detects the amount of light reflected off of the disc from the spot in a predetermined direction, and provides an electrical signal as an output. The photodetector output provides a measurement of the track-to-track spacing of the recording medium.

Abstract: An improved stamper and method involved in the replication of optically-readable information bearing members by means of an injection molding process utilizing a stamper having a conformal layer of chromium electrolytically deposited over the encoded surface of an existing optically-readable information bearing nickel stamper. Nickel stampers produce replicas having structural and optical defects affecting playability of the replica. The present invention provides improvement in the reduction or elimination of "plowing" and "orange peel" defects through cleaner release at the interface of the master stamper and the stamped article. The invention involves an improved stamper surface comprised of a thin layer of chromium metal deposited over an existing nickel stamper. Such a surface insures a cleaner release at the interface of the master stamper and stamped article.

Abstract: A transparent record disc is provided which may appropriately have video signals optically recorded thereon, the record is composed of a lamination, for example, of pliant transparent plastic on a base of hard transparent plastic. The base provides strength for the record and the pliant plastic permits the video recording to be impressed into the record by simple embossing means, rather than by stamping or molding by which the surface of the record is actually raised above its melting point and caused to flow. An improved process for forming the video recordings on the disc record is also provided.

Abstract: A method and apparatus for monitoring the focus condition of a writing light beam impinging the writing surface of a recording medium. The present invention operates on the recognition of the fact that light from a laser is very slightly divergent as it emerges from the laser. Accordingly, the reflected light from the medium is convergent as it passes in the reverse direction and it forms a real image of the source plane wave. The image is compared to a reference image indicative of proper focus, and the focus is adjusted until the image matches the reference image.

Abstract: A method and apparatus for developing a compressed bandwidth frequency modulation signal format to increase the playing time per side of a videodisc by compressing the signal bandwidth of the recorded information preferably by a factor of two. Method and apparatus are described and shown for modulating a carrier signal with a color video signal, modulating a subcarrier frequency with at least one audio frequency signal, selecting the carrier and subcarrier frequencies such that the upper frequency deviation limit of the frequency modulated carrier signal is lower than the useful upper frequency limit of the recording medium chosen for the disc, and such that there is no overlap of the chroma baseband signal and the second order chroma sideband. At least one audio subcarrier frequency is located between the first order chroma sideband and the chroma baseband signal, or between the chroma baseband signal and the second order chroma sideband, or between the second order chroma sideband and DC.

Abstract: A video disc player is described for use with a video disc having frequency modulated video information recorded thereon in the form of a plurality of concentric circles or a single spiral. The information track comprises successively positioned light reflective and light non-reflective regions. A focused light beam is caused to be positioned over the center of an information track and the light reflected from the information track is gathered by an objective lens for application to electronic circuitry for recovering the recorded frequency modulated video signals. Radial tracking means are described for maintaining the focused light spot to impinge upon the center of an information track. Lens focusing means are described for positioning the objective lens at the optimum focused position above the information track for gathering the maximum amount of reflected light from the information track.