Abstract: A file folder locating system which includes a transmitter to selectively transmit packets of radio frequency cycles indicative of the coded address of a particular folder. A transponder, attached to the folder, receives the transmission and responds thereto by producing an audible sound which enables the file to be easily located.

Abstract: In a backward compatible video signal recording and playback system for recording a full bandwidth video signal on a limited bandwidth medium utilizing a luminance signal having high frequencies being folded into low frequencies and unfolded on playback, apparatus includes circuitry for selecting a desired level of high frequency performance for a given degree of reverse compatibility and circuitry for recording a signal indicative of the level.

Abstract: Noise estimation circuitry for estimating the noise in a small number of horizontal scanning lines of a video signal includes a lowpass line comb filter responding to said video signal, but not to chrominance-descriptive components thereof. The video signal free from chrominance-descriptive components is repeatedly sampled during the backporch interval of each horizontal scanning line, and the samples are accumulated to generate a revised noise estimate each successive horizontal scanning line.

Abstract: Apparatus and method of synchronizing the component signals of a multi-component augmented television signal between its generation reception are disclosed. The disclosed apparatus includes circuitry which generates a training signal that indicates the position of the first pixel in each horizontal line interval of the video signal. This training signal is inserted into one horizontal line interval of the active video signal for transmission. The receiver includes circuitry which separates the training signal and derives a timing signal from it. The timing signal is used to define the pixel positions of various decoded components of the received video signal to facilitate their combination. The timing signal is also used to align the color subcarrier signal and to generate other carrier and subcarrier signals used in the decoding process. Two training signals are disclosed: a pseudo-random noise sequence and a time-reversed, all-pass filtered, raised-cosine 2T pulse.

Abstract: A digital-to-analog converter generates an analog output signal which is subject to periodically occurring non-monotonic increments in response to consecutive increments of the value of a digital word. Apparatus in accordance with the present invention substantially reduces effects of the non-monotonic increments from disturbing the analog output signal by rapidly incrementing the value of the digital word after the occurrence of each of said non-monotonic increments.

Abstract: Matrix-addressing circuitry for a liquid crystal display using a square-wave potential of first and second opposed phasings and its second harmonic as address voltages, avoiding the need for multi-level address voltages.An appendix of this specification contains a program listing to which a claim of copyright is made. The copyright owner, assignee hereof, hereby licenses the duplication of the patent drawing, but reserves all other copyright rights whatsoever.

Abstract: A video disc playback apparatus for recovering signal from disc records having radially aligned information fields is provided with multiple signal recovery transducers for interactive signal playback. The signal recovery transducers are independently translated to information fields having like synchronization signal components responsive to player program controls and recovered track identification signals. Synchronization signal components recovered by the various transducers are compared to generate an error signal for activating further transducer means to translate the signal recovery transducers tangentially along the prerecorded information tracks and thereby adjust the relative angular location of the signal recovery transducers to reduce the phase differential of the synchronization components of signal between the respective signals and thereby precluding the need for independent frame synchronization apparatus.