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公开(公告)号:CA1220851A
公开(公告)日:1987-04-21
申请号:CA460843
申请日:1984-08-13
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , TAMURA TAKAHIKO , TOKUHARA MASAHARU
IPC: H04N5/16
Abstract: A dark signal component below a predetermined level of a video signal is varied such that a dark peak level is made to coincide with a pedestal level by feedback control. According to this configuration, a signal component toward a white level side above the predetermined level is not changed by dark restoration, thus obtaining stable color reproduction and stable brightness which are not affected by the dark restoring operation.
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公开(公告)号:CA1220268A
公开(公告)日:1987-04-07
申请号:CA460833
申请日:1984-08-13
Applicant: SONY CORP
Inventor: TAMURA TAKAHIKO , TOKUHARA MASAHARU
Abstract: A CRT drive control circuit for automatically limiting beam current when it is too large. A brightness reduction control and a contrast reduction control are alternately applied in accordance with a dark level detection of a video signal.
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公开(公告)号:FR2486339B1
公开(公告)日:1986-08-22
申请号:FR8112894
申请日:1981-06-30
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , OMURO SHIGERU , KITA HIROYUKI , TOKUHARA MASAHARU
Abstract: A synchronous detector for detecting an information signal modulated onto a carrier, such as a video IF signal, is disclosed in which there are provided a circuit for supplying the modulated information signal in the form of a vestigial sideband signal, a filter circuit coupled to the supplying circuit which includes a tuning circuit tuned to the frequency of the carrier on which the information signal is modulated, an emitter follower circuit connected to the output of the filter circuit, a limiter circuit connected to the filter circuit, for producing a switching carrier, and a multiplier having first and second input terminals coupled to the output of the limiter circuit and to the supplying circuit, for multiplying the modulated information signal and the switching carrier to obtain said information signal. In one embodiment, the limiter circuit includes a differential amplifier having first and second transistors, base electrodes of which are connected to the emitter follower circuit, and third and fourth common base transistors, emitter electrodes of which are respectively connected to collector electrodes of the first and second transistors and collector electrodes of which provide output terminals for supplying the switching carrier.
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公开(公告)号:GB2148070A
公开(公告)日:1985-05-22
申请号:GB8420271
申请日:1984-08-09
Applicant: SONY CORP
Inventor: TAMURA TAKAHIKO , TOKUHARA MASAHARU
Abstract: A CRT drive control circuit for automatically limiting beam current when it is too large. A brightness reduction control and a contrast reduction control are alternately applied in accordance with a dark level detection of a video signal.
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公开(公告)号:GB2145599A
公开(公告)日:1985-03-27
申请号:GB8420657
申请日:1984-08-14
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , TAMURA TAKAHIKO , TOKUHARA MASAHARU
IPC: H04N5/16
Abstract: A dark signal component below a predetermined level of a video signal is varied such that a dark peak level is made to coincide with a pedestal level by feedback control. According to this configuration, a signal component toward a white level side above the predetermined level is not changed by dark restoration, thus obtaining stable color reproduction and stable brightness which are not affected by the dark restoring operation.
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公开(公告)号:FR2551288A1
公开(公告)日:1985-03-01
申请号:FR8413091
申请日:1984-08-22
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , TAMURA TAKAHIKO , TOKUHARA MASAHARU
Abstract: A dark signal component below a predetermined level of a video signal is varied such that a dark peak level is made to coincide with a pedestal level by feedback control. According to this configuration, a signal component toward a white level side above the predetermined level is not changed by dark restoration, thus obtaining stable color reproduction and stable brightness which are not affected by the dark restoring operation.
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公开(公告)号:AU3139484A
公开(公告)日:1985-02-28
申请号:AU3139484
申请日:1984-08-01
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , TAMURA TAKAHIKO , TOKUHARA MASAHARU
IPC: H04N5/16
Abstract: A dark signal component below a predetermined level of a video signal is varied such that a dark peak level is made to coincide with a pedestal level by feedback control. According to this configuration, a signal component toward a white level side above the predetermined level is not changed by dark restoration, thus obtaining stable color reproduction and stable brightness which are not affected by the dark restoring operation.
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公开(公告)号:CA1131768A
公开(公告)日:1982-09-14
申请号:CA327626
申请日:1979-05-15
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , TOKUHARA MASAHARU
Abstract: An automatic fine tuning loop in a television receiver is controlled by phase comparison between a video intermediate frequency signal and a reference oscillator signal. The reference oscillator signal is used in synchronous detection of the video intermediate frequency signal. The frequency of the reference oscillator is controlled by a phase locked loop, of which it is a part, and which includes a low-pass filter having selectable high and low cut-off frequencies. A lock-out detector selects the high cut-off frequency for rapid correction when lock-out is detected and selects the low cut-off frequency for frequency stability when lock-in is detected. An AFT disable switch disables the automatic fine tuning loop during manual tuning. In one embodiment, a disable switch ganged with the AFT disable switch selects the high cut-off frequency in the low-pass filter to prevent hunting.
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公开(公告)号:DE2945563A1
公开(公告)日:1980-05-22
申请号:DE2945563
申请日:1979-11-10
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , OHMURO SHIGERU , TOKUHARA MASAHARU
Abstract: A synchronous detector suitable for use in a color television receiver detects both a video signal and an audio IF signal, but in a fashion in which these two signals do not interfere with one another. In the detector, a tuner provides an IF signal in which the video signal and audio or sound IF signals are modulated on a carrier; a signal generator, such as a phase-locked loop, provides both a detecting signal synchronized with the carrier of the IF signal, and a comparing signal having the same frequency as the carrier of the IF signal but phase-shifted pi /2 therefrom; a synchronous detecting circuit for synchronously detecting the IF signal by the detecting signal to produce the video signal; and a phase comparator for phase comparing the IF signal with the comparing signal to provide the sound IF signal. In one arrangement, the phase comparator provides a filtered version of the sound IF signal as an AFT control signal to control the fine tuning of the tuner. In another embodiment, two phase comparators are included so that the sound IF signal and the AFT control signal are provided separately.
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公开(公告)号:AU5218179A
公开(公告)日:1980-05-15
申请号:AU5218179
申请日:1979-10-25
Applicant: SONY CORP
Inventor: HONGU MASAYUKI , OHMURO SHIGERU , TOKUHARA MASAHARU
Abstract: An automatic fine tuning (AFT) circuit includes a frequency discriminator for discriminating an intermediate frequency signal, a capacitor supplied with the discriminated intermediate frequency signal to produce an AFT voltage thereacross, a comparator circuit for comparing the AFT voltage with a reference voltage, a first switching transistor controlled by the comparator circuit and which supplies and charges the capacitor with the reference voltage during a channel selection operation when the AFT voltage is less than the reference voltage, a second switching transistor controlled by the comparator circuit and which connects the capacitor to ground to discharge the same during a channel selection operation when the AFT voltage is greater than the reference voltage, and a third switching transistor for rendering the comparator circuit operative during a channel selection operation and inoperative during an AFT operation.
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