-
公开(公告)号：CA1192991A
公开(公告)日：1985-09-03
申请号：CA420165
申请日：1983-01-25
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II
Abstract: A television receiver includes a character generator (62) for permitting kinescope (25) display of auxiliary characters in addition to display of normal video signal information, and means (36) for sensing a given characteristic (e.g., bias) of video signal processing circuits of the receiver during prescribed sensing intervals. The character generator is disabled (58) during the sensing intervals to prevent false outputs from the character generator from distorting the characteristic being sensed.
-
公开(公告)号：CA1180066A
公开(公告)日：1984-12-27
申请号：CA409556
申请日：1982-08-17
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II
Abstract: RCA 75,96 A circuit for linearly controlling the gain of a differential amplifier includes a differentially connected current splitter network biased by means of a symmetrical bias circuit coupled to a common operating potential and including first and second current sources with associated first and second impedances. The current splitter includes a diode exhibiting a non-linear voltage in response to linear current conduction, and a transistor. The bias circuit responds to a variable gain control voltage for causing the diode to conduct current which varies linearly with the gain control voltage. First and second mutually differential control voltages derived from the transistor and diode, including a non-linearly varying voltage exhibited by the diode, are applied to the differential amplifier for controlling the conduction of the differential amplifier linearly with respect to the original control voltage.
-
公开(公告)号：CA1175559A
公开(公告)日：1984-10-02
申请号：CA409555
申请日：1982-08-17
Applicant: RCA CORP
Inventor： SHANLEY ROBERT L II , HARWOOD LEOPOLD A
Abstract: -14- RCA 77,258 Input video signals are applied to a video signal processor via an AC coupling capacitor and an input impedance. A gated control circuit operates periodically to develop a DC control voltage for establishing the DC black reference level of the video signal, at which time the control circuit forms a feedback loop with the video processor. The DC feedback control voltage is coupled via a feedback impedance to the AC coupling capacitor, which stores the control voltage, at the video processor input. The AC coupling capacitor exhibits a low impedance at signal frequencies, such that the input and feedback impedances form a voltage divider for sufficiently reducing the AC signal gain of the feedback loop to prevent the feedback control loop from oscillating at AC signal frequencies.
-
公开(公告)号：DD157847A5
公开(公告)日：1982-12-08
申请号：DD21877080
申请日：1980-01-31
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WITTMANN ERWIN J , SHANLEY ILL ROBERT L
Abstract: Brightness control apparatus for a video signal image reproducing system including a video signal processing channel, a kinescope driver for supplying video signals to an image reproducing kinescope, and a source of substantially fixed potential to which signals processed by the kinescope driver are referenced. A comparator senses the substantially fixed reference potential and a blanking level which occurs during periodic blanking intervals of the video signal, and provides an output control signal indicative of the voltage difference between the reference potential and the blanking level. The control voltage is applied to the video channel for translating the blanking level in a direction to minimize the voltage difference, to thereby establish the conduction of the kinescope driver during image intervals of the video signal at a level corresponding to a desired image black level condition when such condition is manifested by the video signal.
-
公开(公告)号：CA1135402A
公开(公告)日：1982-11-09
申请号：CA344639
申请日：1980-01-29
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WITTMANN ERWIN J , SHANLEY ROBERT L II
Abstract: RCA 72,669 of the Invention Brightness control apparatus for a video signal image reproducing system including a video signal processing channel, a kinescope driver for supplying video signals to an image reproducing kinescope, and a source of substantially fixed potential to which signals processed by the kinescope driver are referenced. A comparator senses the substantially fixed reference potential and a blanking level which occurs during periodic blanking intervals of the video signal, and provides an output control signal indicative of the voltage difference between the reference potential and the blanking level. The control voltage is applied to the video channel for translating the blanking level in a direction to minimize the voltage difference, to thereby establish the conduction of the kinescope driver during image intervals of the video signal at a level corresponding to a desired image black level condition when such condition is manifested by the video signal.
-
Patent Agency Ranking
公开(公告)号：PL231846A1
公开(公告)日：1982-02-01
申请号：PL23184681
申请日：1981-06-24
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A
Abstract: A circuit is described for protecting a semiconductor junction device such as a transistor against damage from high voltage transients that can be produced by kinescope arcing in a television receiver. The protected device is coupled to a circuit point at which the transients can appear. The protection circuit comprises a normally nonconductive protection transistor with a collector coupled to a source of operating potential, a base coupled to a source of threshold conduction bias reference voltage, and an emitter connected to the circuit point at which high voltage transients are likely to appear. The base bias of the protection transistor is determinable independent of the bias of the protected device, and the protection circuit is connected to the protected device with substantially zero voltage offset between the circuit point and the protected device. The protection transistor conducts in response to transient voltages appearing at the circuit point above a threshold level, and provides a path for safely diverting potentially destructive transient current away from the protected device.
-
公开(公告)号：PL229955A1
公开(公告)日：1981-09-18
申请号：PL22995581
申请日：1981-03-02
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L
Abstract: A first resistive current path is DC connected between respective output terminals of push-pull color demodulator. A second resistive current path is DC connected between respective output terminals of a second push-pull color demodulator. An output color-difference signal is formed by a differential amplifier having one input DC connected to an asymmetrically positioned point in first resistive current path, and a second input DC connected to an asymmetrically positioned point in second resistive current path. Output color-difference signal corresponds to a combination of the demodulated signals, with a polarity relationship and magnitude ratio determined by the asymmetry of positioning of the takeoff points in the respective current paths. Output quiescent voltage is independent of the asymmetry of positioning of the takeoff points.
-
公开(公告)号：PL206618A1
公开(公告)日：1979-03-26
申请号：PL20661878
申请日：1978-05-05
Applicant: RCA CORP
Inventor： TUMA ALOIS V , HARWOOD LEOPOLD A , GROENWEG WILLEM H
Abstract: Brightness control apparatus for a video signal image reproducing system including a video signal processing channel, a source of reference voltage for establishing a desired level of image brightness, and a keyed comparator circuit. The comparator forms a closed control loop with the signal processing channel, and is keyed during periodic blanking intervals of the video signal to sense the magnitude of the reference voltage and a brightness representative blanking level of the video signal which may vary undesirably. The comparator provides an output control signal indicative of a voltage difference between the reference voltage and the blanking level. The control voltage is applied to the signal channel for translating the blanking level in a direction to minimize the voltage difference, so that a desired relationship between the reference voltage and the blanking level is preserved.
-
公开(公告)号：CA980879A
公开(公告)日：1975-12-30
申请号：CA167112
申请日：1973-03-26
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A
Abstract: A sample and hold detector arrangement suitable for construction in integrated circuit form as an automatic chroma gain control detector, or a color oscillator AFPC detector, or the like. A wide bandwidth analog multiplier circuit is supplied with an intermittent reference signal and a second signal, the phase or amplitude of which is to be sampled. Pulses produced across the broad-band load are processed by a sample and hold circuit which provides substantially symmetrical bidirectional conduction to a filter capacitor during the sampling interval and a high holding impedance during the remainder of each cycle. A differential switching circuit provides rapid transition between the sample and hold functions.
-
公开(公告)号：CA976244A
公开(公告)日：1975-10-14
申请号：CA167111
申请日：1973-03-26
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A
Abstract: A sample and hold arrangement is disclosed having two similar detectors which operate in a complementary manner during each operating cycle. One detector is keyed on during a sampling interval to store information which is to be sampled while the second detector is keyed off. During the remaining part of each cycle, the second detector is keyed on to store quiescent level information while the first detector is keyed off. The sampled information and quiescent level information are applied to a differential comparator to produce an output signal substantially independent of quiescent level variations.
-
-
-
-
-
-
-
-
-
Search Results
92
records
(took 0.024 seconds)
