Abstract: The retrace pulse voltage developed by a horizontal deflection generator is applied to the primary winding of a flyback transformer. The voltage at an intermediate point of the flyback transformer high voltage winding is rectified and filtered to produce an intermediate, DC high voltage. A pulse forming circuit is coupled to a secondary winding of the flyback transformer to produce voltage pulses repeating at the horizontal deflection frequency. The amplitude of the pulses is parabolically modulated at a vertical rate. The amplitude modulated pulses are rectified and filtered to produce a parabolically shaped vertical frequency voltage. The voltage developed across another flyback transformer secondary winding is waveshaped by an LC resonant circuit to produce a sinusoidal or a substantially parabolically shaped horizontal frequency voltage. The intermediate DC high voltage and the parabolically shaped vertical and horizontal frequency voltages are summed to produce the focus voltage.

Abstract: Systems for uniformly reproducing a sound field surrounding a listener are disclosed utilizing three channels of audio information signals. One channel provides signals representative of total sound pressure (a sum signal) and the two remaining channels provide orthogonal pressure gradients (difference signals) representative of location of sound sources which produce the sound field. FM radio systems utilizing the three channel technique for providing surround stereophonic sound are also described.

Abstract: A television signal ghost eliminator is described, including a transversal filter having an input terminal, an output terminal at which a processed video signal is produced, a plurality of signal processing stages serially coupled between the input and output terminals, and a plurality of input taps coupled to the signal processing stages. A detected video signal is applied to the input terminal of the transversal filter and is transferred through the serially coupled stages. A circuit is responsive to the processed video signal for developing a plurality of weighting function signals which are applied to the input taps. The weighting function signals applied to the taps are combined with the detected video signal as it appears at the tapped stages, resulting in reduction in ghost signal components in the processed video signal which is produced at the output terminal of the transversal filter.

Abstract: In a signal processor for a beam-scan velocity modulation system in a color TV receiver, a video signal derived from the receiver's luminance channel (or from a combination of the color signal inputs to the receiver's kinescope drivers) is applied to a CR differentiator. Differentiator output is applied to the base of a first transistor disposed with a second transistor to form a first differential amplifier, and to the base of a third transistor disposed with a fourth transistor to form a second differential amplifier. Common load circuit for double-ended limiter formed by the two amplifiers is coupled to collectors of third and fourth transistors. Base bias for second transistor is positively offset from common base bias for first and third transistors, while base bias for fourth transistor is negatively offset therefrom.

Abstract: In a dual-standard PAL/SECAM color TV receiver, an identification system provides a mode-switching output, permitting automatic switching of the receiver between a PAL-reception mode of operation and a SECAM-reception operating mode, in dependence upon the PAL or SECAM nature of the transmission received. In the SECAM-reception mode, a PAL decoder receives the chrominance component output of a SECAM-PAL transcoder; in the PAL-reception mode, the PAL decoder receives chrominance signals which bypass the transcoder. Luminance signal channel of the dual-standard receiver includes a switchable luminance signal delay line in cascade with a chrominance component trap circuit. Switchable delay line is controlled by mode-switching output of identification system such that delay line is interposed in luminance signal path only during SECAM-reception mode operation.

Abstract: An inverter applies a square-wave exciting voltage of horizontal deflection frequency to the primary winding of a ferroresonant power transformer. A square-wave alternating polarity output voltage developed across a secondary winding of the ferroresonant transformer is half-wave rectified and applied to an input choke of a horizontal deflection circuit. The input choke is coupled to the series arrangement of a horizontal deflection winding and a trace capacitor. A pincushion correction circuit switching transistor applies a DC voltage to the input choke at a controlled instant within the nonconduction interval of the half-wave rectified output voltage. The peak-to-peak horizontal scanning current is a function of the average voltage developed across the trace capacitor. This average voltage equals the average value of the voltage applied to the input choke.

Abstract: A flat major surface of a disc-shaped substrate (e.g., of glass) is coated with a light-reflective layer (e.g., of aluminum). Overlying the reflective layer is a layer of material (e.g., fluorescein) which is highly absorptive for light of a frequency supplied by a recording laser. The coating parameters are chosen to establish an anit-reflection condition for the coated record blank at the recording light frequency. The light output of the laser, which is intensity modulated in accordance with a signal to be recorded, is focused upon the coated surface of the disc as the disc is rotated. With the peak intensity of the focused light sufficient to cause ablation of the absorptive layer, an information track is formed as a succession of spaced pits in which the reflecting layer is effectively exposed. For playback, light of a constant intensity is focused on the information track as the disc is rotated.

Abstract: A deflection generator periodically applies a trace voltage to a deflection winding to produce scanning current and periodically generates a retrace pulse voltage across the deflection winding. A supply voltage source develops the trace voltage and also provides energy to circuits, such as a high voltage circuit, coupled to windings of a flyback transformer. The high voltage circuit develops an ultor accelerating potential from the retrace pulse voltage developed across the high voltage winding of the flyback transformer. A controllable switch such as an SCR is coupled to the source and to a secondary winding of the flyback transformer. The trace voltage and energy transfer is regulated by controlling the conduction time of the SCR. The high voltage and other load circuits draw load current from the source through the flyback transformer secondary winding during retrace, resulting in high voltage retrace pulse duration and amplitude variation with variations in load current.

Abstract: A horizontal deflection generator includes the series arrangement of a horizontal deflection winding and a trace capacitor, a retrace capacitor, and a horizontal trace switch. The trace switch comprises a damper diode and a horizontal output transistor. Base drive for the horizonal output transistor is provided by a horizontal driver stage through a driver transformer. A secondary winding of a flyback transformer is coupled to a high impedance cascade rectifier arrangement to form a DC supply which provides collector supply voltage for the driver stage. The DC supply has a relatively large source impedance to changes in the load current being drawn from the supply by the driver stage. Such a large impedance is desirable in order to limit the base driver to the horizontal output transistor during picture tube arc-over and to allow for duty cycle tolerances in the horizontal oscillator output.

Abstract: A chassis for a television receiver is provided which is adapted to operate in cooperation with any one of a number of electrical subsystems which perform similar functions but have differing signal and power requirements, such as tuners, receiver controls, et cetera, and are located remote from the chassis within the receiver. Each subsystem is coupled to a connector by a cable. The connector includes a row of contacts located in symmetrically spaced holes in the connector. One of the holes is blocked and serves as a keying indication. Mounted on the chassis is a row of similarly symmetrically spaced terminals, with one terminal missing from the row. A connector can only be mated with the terminal row when the blocked hole in aligned with the missing terminal location.

Abstract: A television receiver including a video signal sync separator and keyed signal processing circuits responsive to keying signals supplied by a keying signal generator is disclosed. The output of the sync separator is filtered to develop a bias voltage with a magnitude in accordance with the average output level of the sync separator. The keying signal generator provides periodically timed output keying signals in response to locally generated periodic horizontal flyback signals. The operation of the keying signal generator is enabled or disabled in response to the magnitude of the bias voltage derived from the sync separator output.

Abstract: An electrical circuit suitable for processing vertical detail signal information of a video signal is disclosed. The circuit includes an amplifier and an associated feedback impedance network for determining the circuit gain. Different values of feedback impedance are established in accordance with the operation of a signal responsive switching network included in the feedback network, to establish a signal amplitude transfer function wherein different amounts of signal gain are imparted to signals having amplitudes within prescribed ranges. Small amplitude signals subject to restoration are translated with a prescribed restoration gain. Moderate amplitude signals subject to enhancement (peaking) are translated by amplifying small amplitude excursions thereof with the restoration gain and by amplifying peak amplitude excursions with a gain greater than the restoration gain.

Abstract: An automatic kinescope beam current limiter for a television receiver includes a source of derived beam current representative voltage, a keyed sampling circuit for developing an output beam current control voltage on a charge storage capacitor in response to the derived voltage, and an auxiliary current path including an impedance coupled between the output capacitor and the source of derived voltage. In a normal beam limiting control mode, the control voltage from the sampling circuit serves to modify the television signal in response to the derived voltage in a direction to limit excessive beam current. In an abnormal control mode such as when the sampling circuit is inoperative due to disrupted keying, current is conducted via the auxiliary current path in response to the derived voltage to modify the control voltage on the capacitor with a sense and at a rate for limiting excessive beam current, to thereby preserve beam limiting capability.

Abstract: A video signal channel in a television receiver includes a keyed filter, followed by a keyed automatic brightness control circuit for establishing a desired black or blanking level for the video signal. The brightness control circuit operates during blanking intervals of the video signal to sense the blanking level of the video signal for deriving a control signal which is utilized to maintain a desired blanking level. The filter comprises a high-pass filter circuit which is decoupled for filtering purposes during image intervals, but is coupled to the video channel during the blanking intervals for suppressing high frequency signals including noise, when present, in the video channel during the blanking intervals. The sensed blanking level and the control voltage are therefore unaffected by noise components which would otherwise impair the control signal and thereby the operation of the brightness control circuit.

Abstract: In a remote controlled color television receiver, the television receiver power supply is responsive to the state of an on/off command signal. A DC supply voltage is applied to an input terminal of the power supply during both states of the on/off command signal, with the power supply developing an operating voltage at an output terminal only during the on-state of the command signal. A relay type switch is coupled to a degaussing winding and a source of alternating polarity voltage. The switch is responsive to the presence of the operating voltage and applies the alternating polarity voltage to the degaussing winding to generate degaussing current during the occurrence of, illustratively, the on-state of the command signal.

Abstract: A circuit arrangement is provided for multiplexing an input signal and an output signal through a single circuit terminal. Means are coupled to the terminal for selectively applying first input signals to the terminal of a signal level included within a first range of signal levels. Means including a first transistor having an input electrode coupled to a second signal source and an output electrode coupled to the terminal are provided for developing, in the absence of the first input signals, output signals at the terminal which occupy a second range of signal levels which is exclusive of the first range. A second transistor has an input electrode coupled to the terminal and an output electrode, and is biased to be responsive to signals at the terminal which occupy the first range of signal levels.

Abstract: A circuit for generating a composite keying signal includes a burst gate circuit, a clipping circuit, and a voltage divider, in a color television receiver also including means for deriving horizontal and vertical blanking signals and a horizontal sync pulse from a composite color television signal containing a color burst component. The burst gate circuit responds to the lagging edge of the horizontal sync pulse to develop a burst gate pulse encompassing the burst interval. The clipping circuit and the voltage divider serve to clip and translate both the horizontal and vertical blanking signals, which are then combined with the burst gate pulse to produce a composite keying signal. The composite keying signal comprises a first pulse component of desired magnitude as determined by the clipping and voltage divider circuits and occurring during the blanking intervals, and a second pulse component as provided from the burst gate circuit, superimposed on the first pulse and encompassing the burst interval.

Abstract: A deflection generator develops scanning current in a deflection winding and produces a deflection rate alternating polarity voltage at a deflection generator terminal. A first winding of an input transformer is coupled to a source of supply frequency alternating polarity voltage and to a regulator switch for transferring energy from the source to a load circuit coupled to another winding of the input transformer. A second winding is coupled to the deflection generator terminal. The conduction time of the regulator switch controls the amount of energy transferred. A regulator control circuit turns on the regulator switch at a controlled instant within a first polarity interval of the deflection rate alternating polarity voltage to draw current in the first winding from the source. The deflection rate alternating polarity voltage applied to the second winding is reflected to the first winding and commutates off the regulator switch during the alternate polarity interval of each deflection cycle.

Abstract: A composite filter in a color television receiver includes a bridged-T network and a chrominance bandpass filter for mutually separating the luminance and chrominance components of a color television signal. In the bridged-T network, first and second signal paths are coupled between an input source of television signals and an output, the second path including a first reactance. A third signal path including a second reactance is coupled between an intermediate point in the second path and the input of the bandpass filter. The first and second reactances are tuned to the frequency of the color subcarrier signal of the chrominance component. A fourth, resistive signal path is coupled between the input of the bandpass filter and a reference potential. The four signal paths form a first filter for attenuating the chrominance component at the output of the bridged-T network to provide a separated luminance component at the output of the bridged-T network.

Abstract: Apparatus is disclosed in a video signal processing system for automatically monitoring and controlling the blanking (black) current level of an image reproducing kinescope having cathode and grid intensity control electrodes. When cathode blanking current is monitored, a reference voltage is applied to the cathode over the entire monitoring interval, and an auxiliary voltage is applied to the grid electrode during a portion of the monitoring interval. A version of the grid voltage appears as an induced cathode output voltage proportional to the level of cathode blanking current conduction. A voltage responsive sensing network coupled to the cathode provides an output voltage proportional to the difference in cathode current conducted over the monitoring interval. This voltage is processed by a sampling network to produce a control voltage for modifying the cathode bias in a direction to produce the desired cathode blanking current level at or in the vicinity of kinescope cut-off.