Abstract: A magnetic tape timer and method wherein the measured tape time as well as stored cue markers are not affected upon receiving a preset or reset signal. An offset signal is generated and stored as a difference between the preset or reset signal and a tape time which is coincident with receiving the preset or reset signal. The tape time, cue markers and other tape time related values are then modified by the offset signal for further use such as for display.

Abstract: A TV video signal synchronization signal system enables a video device such as a digital special effects system to operate synchronously in response to an input video signal and still produce an output video signal synchronized to a television studio locking reference signal. The video device and the synchronization signal generating subsystem thereof operate in response to a pixel rate clock of approximately 70 ns and in response to a phase command to generate timing for the horizontal sync pulse, color burst signal and video data of the output video signal. The output color burst signal remains phase locked to the locking reference signal with output gating being responsive to the phase command. A ROM interpolator provides subpixel accuracy for the output horizontal sync pulse while output line buffering and interpolation permits the output video data to be phase matched to the reference master sync signal.

Abstract: Apparatus is disclosed for providing error compensation of a video information signal having a PAL format. Sampling of the analog PAL format video information signal is done at a rate of four times the chrominance subcarrier frequency and is done in a precise manner whereby the samples are taken along orthogonal vector axes that are oriented at 45.degree. relative to the U and V vector axis. When samples are taken at the prescribed locations, substitute samples in the form of multi-bit digital words can be used as replacements for defective or missing sample words, which replacement samples exhibit the same vector phase as the defective sample, but which are taken from either the preceding or succeeding line relative to the line in which the defective sample is located. The apparatus of the present invention obviates the necessity of performing any arithmetic computation to derive the value for the sample to be substituted. Moreover, the sample is spatially closely related to the defective sample, i.e.

Abstract: An analog color video information signal is sampled at times determined by a first clock signal of a predetermined frequency whose phase is reversed on every consecutive horizontal line. The obtained samples are digitized and encoded for recording on a magnetic record medium, with the encoded data timed relative to a second clock signal of the predetermined frequency whose phase is continuous. The reproduced encoded data is processed under the control of two additional clock signals, each of which is of the predetermined frequency and has its phase reversed on every consecutive horizontal line. In the processing, the reproduced data is decoded, reclocked relative to a first of the two additional clock signals, has the chrominance component of the video information selectively inverted and converted back to analog form under the control of the second of the two additional clock signals.

Abstract: An improved microprocessor controlled scanning drum servo adapted for use in a recording and reproducing apparatus is disclosed. The scanner servo includes a velocity loop as well as a position loop, and by virtue of the fact that it is controlled by a microprocessor in a unique way, has extraordinary accuracy because the resolving power of the servo is essentially that of the microprocessor itself. The interrupts to the microprocessor occur in sequence with a first interrupt causing the microprocessor to cease current activity, store all required information in a stack register and thereafter wait until a subsequent interrupt occurs which enables it to immediately act to perform control operations with respect to the scanner servo. This enables the velocity loop to perform the vast majority of the work required by the servo and as a result of this, the phase closed servo loop operates as a positioning loop in the true sense.

Abstract: A method of operating a signal recording and reproducing apparatus is disclosed whereby generally continuously and noise-free transfers of signal information are obtained while reproducing the information from a magnetic tape being transported at a changing speed. The apparatus is of the type which utilizes transverse positioning of the transducing head to accurately follow a track during reproducing. While the tape is transported at speeds other than the normal record and reproduce speed, transport derived signals are employed to control the tape transport servo. When the normal speed is attained, the reproduced signal is detected to determine whether synchronous reproduction conditions have been achieved. If synchronous reproduction conditions are not achieved, the transducing head is moved to a new track to effect synchronous reproduction of the signal information.

Abstract: A method and apparatus for dropout compensation of composite color television signals is described in which both the luminance and chrominance components forming a dropout compensation signal are derived from the same portion of the original color television information signal without dropouts immediately preceding the dropout. One horizontal line of the color television signal without dropouts is continuously stored in a memory. When a dropout occurs, the stored television signal line is circulated in the memory. The length of delay of the chrominance component of the stored television signal is controlled from line to line in response to the phase of the color burst synchronizing component of the color television signal being compensated for dropouts. The length of delay of the luminance component of the stored television signal is controlled on consecutive lines in response to the horizontal line synchronizing component of the color television signal being compensated for dropouts.

Abstract: A method and apparatus for accurately positioning a transducing means along a desired path for recording parallel tracks of information being transmitted at varying rates. The apparatus also is arranged to control the transducing means so that accurately follows the tracks during reproducing at various tape transport speeds.

Abstract: Apparatus is disclosed for providing full frame reproduction, i.e., the reproducing of two consecutive video fields, during a still frame or stop action mode in a recording and reproducing apparatus of the type which utilizes transverse positioning of the transducing head to accurately follow a track during reproducing, and at the completion of the reproduction from the track, to properly position the head to either reproduce the next desired track or to again reproduce the same track. The present invention has the capability of reproducing two consecutive fields to obtain full frame picture resolution in the video display in the manner whereby the transducing head which is carried by a movable element is maintained relatively centered within its dynamic range so as to minimize the possibility of picture break-up due to mistracking.

Abstract: Metal surfaces such as the working surfaces of nickel plated blanks for rigid memory discs are polished in a two-stage process of rough and finish polishing by a combination of mechanical and chemical mechanisms. Each stage involves a plurality of cycles in which the surface is polished using a rotating polishing pad with an aqueous suspension of aluminum oxide containing a lubricant-surfactant and a chlorine-containing oxidizing agent present at the surface-pad interface followed by the addition of an aqueous colloidal aluminum oxide sol to the oxidizing agent-containing suspension at the interface which frees the chlorine in the oxidizing agent to exert a chemical polishing action on the surface.

Abstract: Component masks are described for preserving unoccupied holes in a printed circuit board when such board is subjected to wave soldering. Each mask is a body of plastic resistant to adherence to the solder and capable of withstanding the temperature of solder when the printed circuit board is subjected to wave soldering and includes a supporting block from which a plurality of parallel pins protrude for reception into the printed circuit board lead-holes to be preserved. The pins are spaced from one another by distances equal to the distances between lead-holes on a printed circuit board, and component masks are provided respectively having a single row and a double row of such pins. Each pin is tapered slightly toward its free end, and is connected to its associated supporting block by a conically shaped transition body.

Abstract: Disclosed herein is an escutcheon for concealing a relatively expensive electronic apparatus, particularly magnetic tape players disposed in automobiles and the like. The escutcheon includes a face plate having indicia disposed on a front face thereof suggestive of a relatively inexpensive AM radio. The escutcheon includes means insertable into a receptacle provided for receiving magnetic tape magazines for firmly anchoring the escutcheon onto the magnetic tape player. The escutcheon disguises the appearance of an expensive electronic apparatus as an inexpensive radio to conceal its identity so as to thwart thieves.

Abstract: Wood particles are distributed in selected patterns and bonded together by an adhesive to form a multilayer wood particleboard. The board has a central core of three layers of wood strands sandwiched between two outer surface-forming layers of fine wood particles. The wood strands forming the central core have a length which is several times greater than their width, with their fiber elements substantially parallel to their length. The fine wood particles are irregularly contoured wood particles having a width and thickness less than the average width of the strands forming the central core layers. Each of the three central core layers has its wood strands distributed in a parallel orientation pattern, with the strands in the outer two layers of the core parallel and the strands of the center layer perpendicular to those of the outer two layers to form a layer-to-layer cross-oriented strand pattern.

Abstract: A first digital data memory is responsive to a first clock signal varying at a rate in accordance with the timing errors contained in a stream of digital data to enter the digital data for temporary storage. The stored digital data is retrieved from storage in the first digital data memory in response to a second clock signal of a stable reference rate. The relative times of entering and retrieving the digital data in the first digital memory are set according to the occurrence of a selected sequence of digital data bits contained in the digital data. The digital data retrieved from the first digital data memory is further temporarily stored in a second digital data memory for an interval determined by the time difference between the occurrence of the selected sequence of digital data bits and the occurrence of a reference time signal.

Abstract: A disk mastering preview system utilizes an original audio signal from an audio source for previewing signals to be recorded by a disk lathe. Delayed audio signals corresponding to the original audio signals are produced for recording by the disk lathe a predetermined time delay thereafter. The original audio signals are sampled periodically by a sample and hold circuit to produce analog sample signals indicative of the signals sampled. An analog to digital converter converts the analog sample signals to corresponding digital sample signals. Successive digital sample signals are written into successively addressed memory locations and read out an adjustable predetermined number of memory addresses subsequently. A digital to analog converter converts the digital sample signals read out of memory into analog signals for recording. The predetermined number of addresses is set in a time delay register which produces a signal indicative of the number.

Abstract: A method and apparatus is disclosed for obtaining second order velocity error correction signals for use in a time base corrector that removes instabilities in a video information signal reproduced from a magnetic medium. The apparatus utilizes the phase of the color burst component of the video information signal from successive horizontal lines to determine the change in velocity error. The change in the phase of the burst components of successive horizontal lines is first used to generate a first order or straight line approximation of the velocity error, and the difference between successive changes in burst phase, from which two successive first order error approximations are generated, is used to determine the approximate rate of change of velocity error.

Abstract: In an apparatus for automatically maintaining a transducing head assembly on the proper track, which is particularly adapted for a helical scan recording and/or reproducing apparatus capable of providing special motion effects, an automatically compensated movable head servo is disclosed. The apparatus is of the type which utilizes transverse positioning of the transducing head assembly to accurately follow a track during reproducing and, at the completion of the reproduction from the track, to properly position the head in position to either reproduce the next adjacent successive track, reproduce the same track or reproduce another track so that the appropriate special motion effect is achieved. Proper tracking is maintained by applying a small oscillatory motion to the head to cause it to vibrate laterally of the track, examining the resulting modulation of the reproduced signal's envelope to generate a tracking error correction signal and applying the error correction signal to the head assembly.

Abstract: Apparatus is disclosed for providing error compensation for a digital video information signal and is particularly adapted for use with a PAL format video information signal. The apparatus takes advantage of sampling being done in a precise manner, i.e., at a rate of four times the chrominance subcarrier frequency of the PAL information signal, and alternately along the U and V vector axes. The apparatus generates a substitute value for a defective sample that is the average of selected samples which are in close proximity to and which are of the same type as the defective sample. More particularly, replacement samples taken along the U vector axis (U samples) are generated by averaging the nearest in proximity U samples and the replacement V samples are obtained by averaging the nearest in proximity V samples. Switching means appropriately substitute the generated values for the defective values so that V samples replace V defective samples and U samples replace defective U samples.

Abstract: A method of operating a signal recording and reproducing apparatus is disclosed whereby generally continuously and noise-free transfers of signal information are obtained while reproducing the information from a magnetic tape being transported at a changing speed. The apparatus is of the type which utilizes transverse positioning of the transducing head to accurately follow a track during reproducing. While the tape is transported at speeds other than the normal record and reproduce speed, transport derived signals are employed to control the tape transport servo. When the normal speed is attained, the reproduced signal is detected to determine whether synchronous reproduction conditions have been achieved. If synchronous reproduction conditions are not achieved, the transducing head is moved to a new track to effect synchronous reproduction of the signal information.

Abstract: A method and apparatus is disclosed for controlling the sampling of a composite analog color video signal so that the analog signal is sampled at precise locations relative to the phase of the color subcarrier of the color video signal in the absence of modulation. The invention thereby enables a digitized signal having a constant phase relationship relative to the unmodulated subcarrier phase to be provided which can be advantageously used in magnetic recording and reproducing apparatus. Since the constancy of the location of the samples relative to the phase of the color burst is maintained prior to recording, there is no phase error that would pose a problem during reproducing of the signal.