Thomson Consumer Electronics Inc.

Rca Licensing Corporation

Rca Inc.

Thomson Licensing

Thomson Licensing S.a.

Jeffery B Lendaro

James A Wilber

Robert L Shanley, Ii

Jack Craft

Michael L Low

David W Luz

Alan Anderson Hoover

Robert Joseph Gries

Robert E Morris, Jr

Charles M White

James H Doty, Ii

A timing generator and method of developing drive signals which, when input sync signals are present, delivers the leading and trailing edges of the input pulses directly to a drive output and which generates a free-running signal when input sync pulses are not present.

Timing generator

A video imaging apparatus includes a source of a blanking signal that is indicative when a blanking interval occurs in a video signal. A delay circuit including a horizontal line counter is responsive to the blanking signal and to a signal at the horizontal rate for delaying the blanking signal by a multiple number of horizontal periods to generate a delayed signal. A dynamic focus voltage generator includes a switch responsive to the delayed signal for applying a dynamic focus voltage to a focus electrode, when the switch is at a first state, and for disabling the application of the dynamic focus voltage, when the switch is at a second state. An end time of the interval, during which the dynamic focus voltage is disabled, is determined in accordance with an output signal of the counter.

Control signal generator for dynamic focus disabling

A complementary push-pull emitter follower amplifier is coupled between the output of a high voltage driver amplifier and the cathode of a kinescope for reducing the effective capacitance presented to the driver amplifier that is attributable to the kinescope cathode, socket, spark gaps and related stray capacitances. A secondary undesired capacitance loading of the amplifier attributable to the collector to base capacitances of the follower amplifier is effectively reduced by regulating the collector emitter voltages of the push-pull follower output transistors at respective substantially constant values thereby improving parameters such as the slew rate and bandwidth of the overall video display system.

Kinescope driver apparatus

A video display system comprises a video display for simultaneously displaying pictures representative of first and second video signals, having first and second synchronizing signals respectively. A switch selectably couples the video display with one of the first and second synchronizing signals. A horizontal synchronizing component of the first synchronizing signal is detected by a sensing circuit, the switch being responsive to the sensing circuit. The video display is synchronized with the first synchronizing signal when the horizontal synchronizing component of the first video signal is sensed and is otherwise synchronized with the second synchronizing signal.

Automatic synchronization switch for side-by-side displays

In a television receiver including a feature allowing a user to select a color temperature at which whites will be produced on a display screen, circuitry is provided for altering the gain of the red and blue kine driver stages and simultaneously automatically altering the gain of the R-Y and B-Y color difference signal amplifier, to correct for errors which would otherwise be introduced by adversely altering the B-Y/R-Y ratio.

Color temperature selection circuitry having color matrix correction

An arrangement for ensuring that a proper control level for a controlled unit is maintained when a supply voltage is removed from a control unit of a control system includes a switching circuit coupled between the control unit and the controlled unit. The controlled unit couples the control signal generated by the control unit to the controlled unit when the supply voltage is present and is responsive to the absence of the supply voltage for decoupling the output of the controlling unit from the input of the controlled unit. In this manner, a current path established by a protection circuit within the control unit when the supply voltage is removed is decoupled from the controlled unit and does not adversely affect the operation of the controlled unit.

Control system including a switching circuit for ensuring proper

A circuit is presented for operating discrete integrated circuits from a common bias source by DC coupling the individual bias circuits of the discrete IC's together to eliminate signal coupling capacitors otherwise required between the discrete IC's, and to eliminate the individual bias bypass capacitors otherwise required for the discrete IC's.

Common bias circuit for a plurality of discrete IC's each having their

A stereo expansion circuit has right and left amplifying channels for providing expanded stereo signals. A selection device comprises a switch cross coupling the signal channels for providing expanded stereo when the switch is closed. Circuitry is provided for preventing the switching control signal from being coupled to the signal channels. More specifically, a version of a signal coupled between the signal channels through the conduction channel of the switch is applied to the control input of the switch to inhibit the control signal from being coupled to the conduction channel. Such an arrangement is particularly advantageous when the switch comprises a J-FET.

Stereo expansion selection switch

The present invention relates to electronic circuits, such as an operational amplifiers, which have dual power supply requirements. When the power supply voltages are switched between an 'off' state and an 'on' state, the power supply transient voltages of the two polarities closely track each othe so as to reduce audio transients from being produced within the operational amplifiers. This tracking is accomplished by the negative polarity power supply voltage being provided for the signal amplifier at the output terminal of an unity gain operational amplifier having an inverting input terminal coupled to the positive polarity power supply voltage.

Audio system with transient tracking dual voltage power supply

The present invention concerns apparatus having a voltage controlled amplifier wherein the gain of the amplifier is determined in response to the level of a control signal at an input terminal. A first rate of change is used for a change of gain from a low signal level to a higher signal level, and a second rate of change is used for a change from a high signal level to a lower signal level with the second rate being faster than the first rate.

Plural time constant signal control

A horizontal deflection system comprises a horizontal deflection yoke and a resonant retrace circuit coupled to the yoke and to a switched energy source for generating a horizontal deflection current in the yoke. A diode modulator is coupled to the resonant retrace circuit. A control circuit operable in a switched mode supplies a control signal to the diode modulator for modifying the deflection current to correct for side pincushion distortion. A transformer has a first winding coupled to the diode modulator and to the control circuit for recovering energy from the diode modulator. The transformer has a second winding for receiving the recovered energy from the first winding. A diode clamp is coupled to the second winding and to a load driven by a voltage source at a first voltage level, for transferring the recovered energy from the second winding to the load. The energy is transferred from the first winding to the second winding at a second voltage level across the first winding determined by the first voltage level and the turns ratio of the transformer. The second voltage level defines an effective voltage clamping level and is related to the operating range of the diode modulator. The second voltage level can be adjusted to levels different from the first voltage level by changing the turns ratio of the transformer.

Transformer coupled voltage clamp for pincushion correction circuit

To produce a cathode voltage of a cathode ray tube that provides black level compensation, a secondary winding of a flyback transformer is coupled in series with a resistor, a capacitor and a rectifying diode. During flyback, a voltage pulse is developed across the capacitor at a magnitude that is increases when the average value of the beam current increases. The voltage pulse causes the cathode voltage to first decrease when the beam current increases.

Power supply for an electrode of a CRT

An arrangement that compensates for a tendency in a raster width of a display screen of a video display or television to increase when a variation in a beam current occurs, decreases an amplitude of a deflection current to decrease in a nonlinear manner as a function of an increase in the beam current. At a low beam current, a given increase in the beam current produces a decrease in the amplitude of the deflection current that is substantially greater than caused by the same increase at a high beam current.

Raster size regulating circuit

Active turn-off or disabling circuits respond to control signals from a control unit which defines the mode of operation of a receiver. In response to a designation of a standby mode of operation the active disabling unit actively disables a pulse width modulator to prevent pulses from being produced based upon an input of ringing signal. In addition, the active disabling circuits prevent such ringing signal from negatively effecting pincusion protection circuits. The ringing signal is produced in a horizontal flyback transformer during a transition interval that follows a transition to standby mode of operation.

Disabling arrangement for a circuit operating at a deflection rate

A base voltage of a regulator transistor is developed during normal operation in a filter capacitor coupled to a flyback transformer of a horizontal deflection circuit. After a transition to a standby mode of operation, the deflection circuit is disabled and the capacitor begins discharging. The emitter of the transistor is coupled to a load circuit. A supply voltage is coupled to the collector of the transistor during both standby and normal mode. To reduce the loading of a standby power supply that generates the collector voltage as along as the capacitor is not fully discharged, an active turnoff of the regulator transistor is provided immediately after the receiver goes into the standby mode of operation so as to actively turnoff the current drawn by the transistor.

Growing community of inventors

Noblesville, IN, United States of America

Jeffery B Lendaro