公开(公告)号：KR830000225B1

公开(公告)日：1983-02-23

申请号：KR780003155

申请日：1978-10-19

Applicant: RCA CORP

Inventor： HARWOOD LEOPOLD A ,  GROENEWEG WILLEM H ,  TUMA ALOIS V

IPC: H04N9/50

Abstract: In a PAL color television system for processing a color signal including burst and chrominance components alternating in phase at the image line scanning rate, identification and control circuitry for rapidly correcting an incorrect mode of line to line color demodulator switching. A bistable circuit generates timing signals for controlling line by line switching of a selected color demodulator(e. g., R-Y). An identification signal representative of an incorrect line switching mode is derived from information contained in the burst component, and serves to reset the bistable circuit such that timing signals corresponding to a correct switching mode are produced.

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

IPC: H04N5/57 ,  H04N5/59 ,  H04N5/58

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：PL209838A1

公开(公告)日：1979-07-02

申请号：PL20983878

申请日：1978-09-25

Applicant: RCA CORP

Inventor： HARWOOD LEOPOLD A ,  GROENEWEG WILLEM H ,  TUMA ALOIS V

IPC: H04N9/465 ,  H04N9/47 ,  H04N9/68 ,  H04N9/70 ,  H04N

Abstract: In a PAL color television system for processing a color signal including burst and chrominance components alternating in phase at the image line scanning rate, identification and control circuitry for rapidly correcting an incorrect mode of line to line color demodulator switching. A bistable circuit generates timing signals for controlling line by line switching of a selected color demodulator (e.g., R-Y). An identification signal representative of an incorrect line switching mode is derived from information contained in the burst component, and serves to reset the bistable circuit such that timing signals corresponding to a correct switching mode are produced. The identification signal is derived by a filter circuit exhibiting a fast response time relative to the line scanning time, in order to rapidly respond to the switching mode identification information occurring at the line rate and thereby rapidly restore the correct demodulator switching mode.

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

IPC: H04N5/59 ,  H04N

公开(公告)号：CA1110758A

公开(公告)日：1981-10-13

申请号：CA302551

申请日：1978-05-03

Applicant: RCA CORP

Inventor： TUMA ALOIS V ,  HARWOOD LEOPOLD A ,  GROENEWEG WILLEM H

IPC: H04N5/57 ,  H04N5/59 ,  H01L23/48

Abstract: BRIGHTNESS CONTROL CIRCUIT EMPLOYING A CLOSED CONTROL LOOP of the Invention 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：CA1107853A

公开(公告)日：1981-08-25

申请号：CA312062

申请日：1978-09-26

Applicant: RCA CORP

Inventor： HARWOOD LEOPOLD A ,  GROENEWEG WILLEM H ,  TUMA ALOIS V

IPC: H04N9/465 ,  H04N9/47 ,  H04N9/68 ,  H04N9/70 ,  H04N9/50

Abstract: RCA 71,473 PAL SWITCHING CONTROL CIRCUIT of the Invention In a PAL color television system for processing a color signal including burst and chrominance components alternating in phase at the image line scanning rate, identification and control circuitry for rapidly correcting an incorrect mode of line to line color demodulator switching. A bistable circuit generates timing signals for controlling line by line switching of a selected color demodulator (e.g., R-Y). An identification signal representative of an incorrect line switching mode is derived from information contained in the burst component, and serves to reset the bistable circuit such that timing signals corresponding to a correct switching mode are produced. The identification signal is derived by a filter circuit exhibiting a fast response time relative to the line scanning time, in order to rapidly respond to the switching mode identification information occurring at the line rate and thereby rapidly restore the correct demodulator switching mode.

公开(公告)号：CA1096489A

公开(公告)日：1981-02-24

申请号：CA302568

申请日：1978-05-03

Applicant: RCA CORP

Inventor： TUMA ALOIS V ,  HARWOOD LEOPOLD A ,  GROENEWEG WILLEM H

IPC: H04N5/59 ,  H04N9/16

Abstract: RCA 71,468 IMPROVED AVERAGE BEAM CURRENT LIMITER of the Invention An average beam current limiter for a kinescope responsive to video signals coupled to the kinescope via a signal transmission channel comprises a source of control signals representative of average current drawn by the kinescope. When average beam current exceeds a predetermined threshold level by an amount within a first range of beam current, a corresponding control signal is coupled to the signal transmission channel to vary the D.C. content of the video signal in a direction to limit beam current above the threshold level within the first range. When beam current exceeds the threshold level by a relatively greater amount within a second range of current, a corresponding control signal serves to vary the peak amplitude of the video signal to limit beam current within the second range.