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公开(公告)号：CA1065469A
公开(公告)日：1979-10-30
申请号：CA252994
申请日：1976-05-20
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A
Abstract: HUE CORRECTION APPARATUS HAVING A RESTRICTED RANGE of the Invention Hue correction apparatus of the flesh tone correction type is provided. Chrominance signals are monitored on a dynamic basis and the phase of a color subcarrier reference signal is automatically altered when the chrominance signals are in the vicinity of the flesh tone (+I) axis. The phase of the reference subcarrier is altered, making use of a wide bandwidth phase detector, by controllably adding a portion of an amplitude limited chrominance signal to the subcarrier so as to shift the subcarrier phase towards the phase of the chrominance signal. The range of angles and response of the apparatus is restricted by means of an offset bias control coupled to the chrominance signal adder circuits. Green and blue tones are relatively unaffected by the system operation. Good transient response of the correction apparatus is provided at sharp color transitions.
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公开(公告)号：PL206619A1
公开(公告)日：1979-03-26
申请号：PL20661978
申请日：1978-05-05
Applicant: RCA CORP
Inventor： TUMA ALOIS V , HARWOOD LEOPOLD A , GROENWEG WILLEM H
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公开(公告)号：CA1037571A
公开(公告)日：1978-08-29
申请号：CA252984
申请日：1976-05-20
Applicant: RCA CORP
Inventor： COCHRAN LARRY A , HARWOOD LEOPOLD A
Abstract: CONTROLLABLE GAIN SIGNAL AMPLIFIER A signal amplifier is supplied with input signals at its base electrode and also is supplied at its emitter with quiescent operating current from a current source. Amplified output signals developed at the collector of the amplifier are coupled to a transistor diode current splitter. The relative division of current in the splitter is controlled by coupling a variable direct current supply to the diode. The latter supply comprises a source of direct voltage, a variable resistive voltage divider coupled across the voltage source, and the combination of a voltage follower stage, a first series resistor coupled between the resistive divider and the input of the voltage follower and a second resistor coupled between the output of the follower and the diode. Gain controlled push-pull output signals may be provided by differentially coupling a second amplifier device to the first and coupling the output of a second current splitter to the second amplifier. The second current splitter is then also controlled by the same current source as the first.
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Patent Agency Ranking
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公开(公告)号：CA758189A
公开(公告)日：1967-05-02
申请号：CA758189D
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , MURAKAMI TOMOMI
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公开(公告)号：CA1249879A
公开(公告)日：1989-02-07
申请号：CA514635
申请日：1986-07-24
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , WARGO ROBERT A , PATEL CHANDRAKANT B
Abstract: A composite video signal is comb filtered to generate comb filtered chrominance and luminance signals. A baseband color difference signal is produced from the comb filtered chrominance signal and the presence of high frequency information in the baseband color difference signal is detected to develop a control signal. The bandwidth of the low frequency portion of the comb filtered chrominance signal (i.e. the vertical detail information) which is restored to the comb filtered luminance signal is varied in response to the control signal.
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公开(公告)号：CA1230674A
公开(公告)日：1987-12-22
申请号：CA492646
申请日：1985-10-09
Applicant: RCA CORP
Inventor： WARGO ROBERT A , HARWOOD LEOPOLD A
IPC: H04N9/68
Abstract: A system for controlling overload of a chrominance component processor output includes means for comparing the processor output signal magnitude with a predetermined maximum desired magnitude value. Occurrences of the processor output signal magnitude exceeding the predetermined magnitude are identified as overload occurrences only if the duration of the excess continues for an interval of a width determined by the noise content of the processor output signal. An overload control value is produced, corresponding to the average value of the processor output signal magnitudes over each such interval. Means are provided for detecting the number of separate times within a given time period (e.g., field or frame interval) that an overload control value is produced. Additional means, responsive to the overload control values and to the detected number, develop an overload control signal which is substantially representative of the average of the respective overload control values developed during one of said given time periods. Scaling of the overload control signal is effected in accordance with the output of the number detecting means.
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公开(公告)号：CA1195767A
公开(公告)日：1985-10-22
申请号：CA423032
申请日：1983-03-07
Applicant: RCA CORP
Inventor： HARWOOD LEOPOLD A , SHANLEY ROBERT L II
Abstract: Signals to be cored are applied to the inputs of a linear signal amplifier, and of a multistage limiting amplifier having cascaded input and output amplifying stages. A cored version of the signals, corresponding to the difference between a linearly translated version of the signals and a doubly clipped version thereof, is developed by a signal combiner responsive to the outputs of both amplifiers. A variable coring level control voltage controls the distribution of gain between the input and output amplifying stages, substantially without disturbing the overall gain of the limiting amplifier, which is set to match the overall gain of the linear amplifier. In an illustrative embodiment, the signals which are adjustably cored are horizontal peaking signals derived from the received luminance signal in a color television receiver. An automatic peaking control system associated with output of the adjustable coring circuit opposes changes in peaking level that might otherwise accompany coring level adjustment.
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