Abstract: A high speed multiplier, such as for video signals features cascaded ROMs. Each ROM is divided into pages, and each page contains different multiplying coefficients. Different significant bits of a control signal are applied to each ROM to select a page for processing the video signal.
Abstract: A dropout compensator for time spread digital television signals uses either horizontal or vertical averaging to replace a dropped out sample. The choice of direction is made in accordance with whichever direction has the least amount of change around the missing sample or pixel. The circuitry can also be used for chroma inversion when stop or slow motion is to be transmitted or recorded.
Abstract: A video scrambling device requires that a key signal be periodically inserted into a subscribers box, e.g. once a month. The key signal is a function of both the box number and the time, and thus once received must be inserted relatively quickly, e.g. an hour or two. If it is not inserted quickly, a new key signal must be obtained. This makes it extremely difficult for a pirate to distribute a key signal to his customers in time for it to be effective. The scrambling method can be pseudorandom line inversion and also audio scrambling.
Abstract: A recording system converts standard binary signals into new binary signals that have mostly zeroes occurring in words that are physically unrealizable. Thus when NRZ-I recording is used, long strings of zeroes (which have no transitions in them for easy detection) do not actually occur. Ones do have transitions in them for easy detection, and thus a long string of ones causes no detection problem. The physically unrealizable combinations occur due to the partial correlations of signals, such as Y, B-Y, and R-Y color signals.
Abstract: A circuit including emitter-coupled transistors improves the symmetry of an applied square wave. A limiter in the collector circuit limits the paraphase output voltage excursion. Changes in energizing voltage affect the current in the limiter and cause incremental changes in the output duty cycle. A compensator includes a voltage divider coupled between the output terminals for producing a control voltage related to the output signal amplitude. The control voltage controls a current source coupled to joined emitters for creating an offsetting current through the limiter.
Type:
Grant
Filed:
January 26, 1982
Date of Patent:
July 24, 1984
Assignee:
RCA Corporation
Inventors:
Joseph F. Hacke, Arthur J. Banks, Lucas J. Bazin
Abstract: A digital multiplier for multiplying together first and second numbers when the first number is a quotient of an integer divided by an integer power of two and the second number has n bits. The multiplier comprises a first register having n-bits, a second register having n+1 bits and a third register having n+2 bits. The first register receives the n-bit second number. The n least significant stages of the second and third registers receive the n-bits of the second number, effectively dividing the value of the second number by two and four, respectively, to form respective third and fourth numbers. A fourth register receives the numerator of the first number and has at least two stages for representing at least a portion of the value of the numerator in the form of one of two preassigned states which may be assumed by the stages of the fourth register.
Abstract: A surface acoustic wave record stylus is constructed from a support having a surface for propagating surface acoustic waves. A circular-shaped interdigital transducer launches the surface acoustic waves onto the support surface. The shape of the interdigital transducer is such that the surface acoustic waves are focused to a diamond stylus positioned at the center of the circular transducer.
Abstract: The player is provided with a pair of spaced apart spine latching members which hook up with an inner record retaining spine as a caddy is inserted into the player so that when the outer jacket is withdrawn, the record/spine assembly is retained inside the player. A caddy overtravel mechanism prevents a selected one of the latching members from latching up the spine until the other latching member is also in position to capture the spine. A rigid coupling member interconnecting the latching members precludes the other latching member from capturing the spine until both latching members are ready to latch up the spine to assure simultaneous latching of the spine.
Abstract: The stylus cleaner includes a stylus wiping pad holder mounted for motion along a path which is angularly disposed with respect to the carriage path. The location of the holder path is such that the stylus arm carriage engages the holder to drive it away from the record, against the force of a spring, as the carriage is driven toward an off-record rest position. The holder, carrying a stylus wiping pad, follows the carriage as it heads toward the record for playback. A stylus lifting/lowering apparatus located in the carriage is momentarily activated to cause engagement between the stylus with the wiping pad at points beyond the periphery of the record to effect stylus cleaning as the carriage is heading away from the off-record rest position.
Abstract: A high-definition television system for electronic cinematography includes vertical scanning for ease of line-rate transcoding or adaptation to standard-definition television systems. The number of vertical line-scans is selected for transcoding to a standard-definition system by deleting alternate vertical line-scan samples.
Abstract: A sampling PLL circuit features a frequency sweep caused by an offset voltage applied to an integrator to avoid false lock ups. At one end of the frequency range the polarity of the offset signal can be reversed. The error voltage can be sampled during a television vertical or horizontal blanking period. Once proper lock up is achieved, the offset signal can be removed.
Abstract: When tape in a VTR moves in the same direction as the direction of peripheral motion of a headwheel across which the tape passes, release of one end of the tape during rewind may cause the tape to whip around the headwheel and jam. The tape accumulation resulting from the motion is accommodated by a tapered open-ended tunnel. After accumulation in the tunnel, the tape is reeled in by the take-up reel.
Abstract: The stylus arm carriage is provided with a slidably-mounted plunger. When the carriage is driven to an off-record home position, a portion of the front wall of the player engages a protruding end of the plunger to drive it in. The other end of the plunger engages a carriage-mounted stylus cleaner mechanism to lock it in place while the carriage is disposed at the home position to prevent the possibility of accidental contact between a pickup stylus and the cleaner mechanism.
Abstract: The effects of crosstalk of an FM carrier from a first signal channel into a second signal channel are reduced by a variable-frequency notch filter coupled in the second channel. The frequency of the notch in the transmission characteristic of the filter is controlled to track the frequency of the FM carrier. Signals in the second channel at the frequency of the FM carrier are attenuated, and therefore the crosstalk signal is attenuated and its effects reduced.
Abstract: A transcoding arrangement transcodes signals sampled at a first frequency into second signals clocked at a second frequency. The first and second frequencies are selected so that their quotient is the ratio of integers. This results in recurrent blocks of samples having integer numbers of input samples and new output samples. A transcoder uses delay elements to form successively delayed samples of the input signal. Subtractors form difference signals representing the amplitude difference between successive delayed samples. Multipliers coupled to the subtractors multiply the difference signals by a running variable multiplicand to form weighted difference signals. The running variable is related to the effective position of the new sample being formed within a transcoding block of samples. The weighted difference signals are summed in an adder to form the new sample values.
Abstract: Color signal samples generated by CCD imagers used with a color stripe filter normally exhibit hue errors owing to cross-color components in the samples arising from misalignment of the color striped imager on the imager elements. These cross-color components are suppressed in the invention, by re-sampling the color signals.
Abstract: Output signals are derived from two portions of a CCD imager. The first output signal is derived from a drain diffusion in the form of a signal current and applied to an amplifier with poor high frequency S/N due to needed high frequency peaking. The second output signal is derived from a floating diffusion (or floating gate) through an on-chip MOSFET amplifier which has a poor low frequency S/N due to 1/f noise. The first and second output signals are filtered through complementary LPF and HPF respectively and then combined together.
Abstract: A multi-electrode array deposited on a piezoelectric substrate is driven by a traveling-wave voltage generated from a wave delay generating device, such as a tapped coaxial cable. Suitably delayed and phased voltages are fed to each electrode in the array. Surface acoustic waves are excited on the surface of the piezoelectric substrate. The surface acoustic waves travel through the array in proper phase with the exciting signal supplied to the electrodes. The surface acoustic waves pick up energy as they travel along the surface. Such a structure has a number of advantages over the prior art conventional interdigital transducers. For example, they exhibit broad bandwidth characteristics, have high conversion efficiency and are generally free of spurious signals. These advantages make them well suited for application to video disc cutterheads.
Abstract: RF switching diodes in the antenna transfer switch of a video disc player are reverse biased by means of a bias supply when the main power supply of the player is turned off. The reverse bias counteracts any tendency for RF signals applied to the player antenna input connector from forward biasing the diodes which otherwise could result in intermodulation distortion of antenna input signals coupled to the player RF output connector. The effect of the reverse bias is augmented by a high pass filter in the antenna transfer switch which attenuates RF input signals at frequencies below the lowest assigned television channel frequency.
Abstract: In a tube/coil assembly of the type wherein the tube includes a gun for directing a beam of electrons to a target electrode and both focus and alignment coils are included within the assembly, the alignment coil is electrically energized with some portion of the current flowing through the focus coil to eliminate the need for an independent alignment coil current source.