Thomson Consumer Electronics Inc.

Thomson Licensing

Rca Licensing Corporation

Mark R Anderson

Robert Preston Parker

Robert E Morris, Jr

Michael Scott Deiss

Darin Bradley Ritter

John A Andrews

An assembly of two or more heatspreaders is attached to a printed circuit board in a compact electronic enclosure. The heatspreaders include fins which assist in convecting heat out of the enclosure through vents. The printed circuit board is shielded from the outer case by the heatspreaders.

Multi-layer heat spreader assembly with isolated convective fins

A digital receiver for processing one of a packetized input data stream and a digitized standard definition input signal is provides a delay in the processing of the standard definition audio input signal to maintain synchronism with the processing of a corresponding standard definition video signal.

Apparatus for providing a video lip sync delay and method therefore

A video input signal is applied to a delay circuit having a plurality of taps which are coupled to maximum and minimum value selection circuits. In the absence of a video signal transient, the center tap of the delay circuit is coupled to an output terminal via an output switch. When a 'white going' transient occurs, the output switch sequentially selects the outputs of the minimum and maximum value selectors for application to the output terminal. When a 'black going' transient occurs, the output switch sequentially selects the outputs of the maximum and minimum value selectors for application to the output terminal. Offset producing circuits are coupled to the minimum and maximum value selectors whereby an output signal is produced having a preshoot, an overshoot and a rapid transition therebetween for video input signal transients of either direction and in which the shoot amplitudes are independently controllable thereby providing the combined transition speed advantages of 'edge replacement' enhancement systems with pre-shoots and overshoots characteristic of transversal peaking systems.

Video signal processor employing edge replacement, preshoots and

A decoding arrangement for decoding audio signals previously encoded in accordance with the dbx format, includes a wideband expander instead of a full dbx expander. The wideband expander employs a relatively simple, and therefore inexpensive, peak detector in place of the true RMS detector of a full dbx expander, and does not include apparatus for spectral expansion of the audio signal. Although the decoding is noncomplementary with respect to the encoding, the stereo audio reproduction as perceived by a listener, is surprisingly good.

Wideband expander for stereo and SAP signals

A protection circuit for an audio output channel of a television receiver includes a detector which detects the presence of either or both of (1) a sustained DC component applied to the loudspeaker form the audio power amplifier, (2) and the loss of a supply voltage for the power amplifier. The presence of a of a sustained DC component can damage the loudspeaker. The loss of a supply voltage of the power amplifier can damage the power amplifier and can also result in the application of a sustained DC amplifier and can also result in the application of a sustained DC component to the loudspeaker. For example, the loss of the negative supply voltage of a power amplifier incorporated in an integrated circuit results in the removal of potential from the substrate which otherwise serves to electrically isolates various semiconductor devices supported by the substrate. The detector includes a low pass filter coupled between the output of the power amplifier and inputs of first and second comparators to detect when the output of the low pass filter is within or outside of a 'window'. A transistor switch is coupled to output of the comparators. As long as the output of the low pass filter is within the window, each comparator generates a respective low level output signal which keeps the transistor switch turned off. However, if the output signal of the lowpass filter is outside of the window, one of the comparators generates a high level output signal signal which causes the transistor switch to be turned on. The comparators normally receive the same supply voltages as the power amplifier, and the loss of the negative supply voltages does not enable either of the comparators to generates a low enough level output signal for keeping the transistor off.

Protection arrangement for an audio output channel

Apparatus is provided for the virtual expansion of the power providing capacity of a power supply, e.g., for a stereophonic audio system with a given number of channels which may be selectively increased to provide a surround audio system. A plurality of amplifiers, each having an adjustable gain, are powered from the power supply. The current drawn from the power supply is sensed. When additional amplifiers are activated, the total amount of power drawn by all of the amplifiers can exceed a predetermined level which corresponds to the original plurality of amplifiers. However, when it is sensed that the total amount of power drawn exceeds the predetermined level, the gain of all of the amplifiers is reduced so that the power drawn from the power supply does not exceed the predetermined level. Thus, the virtual power providing capacity of the power supply is expanded to power the additional amplifiers.

Apparatus for the virtual expansion of power supply capacity

An audio signal processing channel includes a bias network for deriving a bias voltage which is coupled to a point within the channel from the supply voltage. In order to inhibit audible transients or 'pops' due to the rapid reduction of the bias voltage when the voltage supply is deenergized, a diode is coupled between the bias network and the voltage supply so as to selectively decouple a filter capacitor of the bias network from the voltage supply and associated loads when the voltage supply is deenergized. As a result, the bias voltage is gradually reduced at a controlled rate of change which is independent of the impedances of voltage supply and associated loads. Such a 'pop' suppression arrangement is particularly desirable when it is not possible or practical to 'mute' the output amplifier of the channel.

Supply voltage responsive audible transient (POP) suppression arrangement

In a television receiver, employing both a beam scan velocity modulation (SVM) system and an on screen display (OSD) generator, the OSD generator selectively operates to produce characters or graphics which are superimposed on the main video picture display. During operation of the OSD generator, the SVM circuit may tend to undesirably introduce artifacts into the picture display. Circuitry is provided for selectively disabling normal SVM circuit operation during OSD operation to prevent or reduce the perception of such artifacts.

Beam scan velocity modulation apparatus with disabling circuit

A combined RFI filter and low pass filter includes two sections, both of which serve as both radio frequency interference filters and low pass filters, or dc integrators. Both sections have substantially equal time constants and employ non-polarized capacitors.

Combined RFI rejection and intergrating two-section filter

An audio/video signal switching system permits an audio input to be automatically switched from a mode in which it receives audio signals associated with an NTSC signal source, to a mode in which it receives audio signals associated with an S-VIDEO signal source.

Audio switching for an audio/video system having S-VIDEO capability

A system for preventing crosstalk in a stereo television receiver includes a signal selection switch for selecting between signals produced by a demodulator and signals received at an auxiliary input, a controller for generating a switching control signal and circuitry for muting the audio demodulator during channel change and when said auxiliary input is selected in response to said switching control signal.

System for preventing crosstalk in a multi-input electronic device

A stereo expansion circuit selection switch includes a transmission gate to cross couple the right and left channels as needed for stereo expansion.

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Indianapolis, IN, United States of America

Mark R Anderson