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Patent Agency Ranking
公开(公告)号：US3465095A
公开(公告)日：1969-09-02
申请号：US3465095D
申请日：1967-04-26
Applicant: MOTOROLA INC
Inventor： HANSEN ROBERT B , MACINTYRE ERNEST C JR
CPC classification number: H04N5/57
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公开(公告)号：US3597540A
公开(公告)日：1971-08-03
申请号：US3597540D
申请日：1969-04-01
Applicant: MOTOROLA INC
Inventor： MACINTYRE ERNEST C JR
CPC classification number: H04N5/57
Abstract: An automatic brightness control circuit in a color television receiver using direct demodulation of the color and brightness signals derives a brightness control voltage by comparing a reference signal, which is indicative of the cutoff or blacklevel condition of the cathode-ray tube, with the video signals supplied to the base of an NPN transistor output amplifier for the green output channel of the receiver. In one embodiment this is accomplished by the use of a differential clipper which is used to compare a reference voltage indicative of the desired black level with a voltage derived from the emitter of the green final amplifier stage during the scanning interval to provide pulses to an integrating circuit, the output of which is used to vary the DC operating level of the green, blue and red driver amplifiers in a closed-loop control system.
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公开(公告)号：US3622696A
公开(公告)日：1971-11-23
申请号：US3622696D
申请日：1969-04-01
Applicant: MOTOROLA INC
Inventor： MACINTYRE ERNEST C JR
IPC: H04N5/58
CPC classification number: H04N5/58
Abstract: A color television receiver using direct demodulation of the color and brightness signals supplies the output of the video amplifier stage through an automatic contrast control circuit including first and second light dependent resistors. The first light dependent resistor is subjected to the ambient light surrounding the receiver and operates in a voltage divider to provide a varying voltage in accordance with variations of the ambient light level. The output of the voltage divider is supplied through an integrating circuit to the base of a field effect transistor, the output of which is utilized to drive a lamp in an isolator package in which the second light dependent resistor is located. Variations of the light emanating from the lamp cause variations in the resistance of the second light dependent resistor, which is placed in series with the output of the video amplifier to variably attenuate the signals obtained therefrom to provide automatic contrast control. In addition, there is disclosed an automatic brightness control circuit using a differential clipper one input to which supplied with a reference voltage and the other input to which is derived from the output of the green final amplifier stage to cause a comparison of the blackest-going signal during each trace interval. The output of the differential clipper is supplied to a second integrating circuit, the outpt of which is used to vary the DC operating level of the green, blue and red driver amplifiers to form a closed loop control system. Thus, the blackest level of the signal passing through the green amplifier stage is chosen as black for the brightness control circuit and the black level of the receiver is automatically adjusted accordingly.
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公开(公告)号：US3564137A
公开(公告)日：1971-02-16
申请号：US3564137D
申请日：1968-01-26
Applicant: MOTOROLA INC
Inventor： MACINTYRE ERNEST C JR , SLAVIK WILLIAM H
Abstract: A video signal amplifier is direct current coupled to a cathode ray tube, and an amplifier device, which is sensitive to variations in supply voltage and environmental temperature, is coupled to the video amplifier to compensate conduction changes therein and maintain the brightness level of the image despite these variations. The compensation circuit may be part of a system limiting maximum brightness level of the image.
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公开(公告)号：US3421043A
公开(公告)日：1969-01-07
申请号：US3421043D
申请日：1967-04-28
Applicant: MOTOROLA INC
Inventor： MACINTYRE ERNEST C JR , HANSEN ROBERT B
CPC classification number: H04N9/28 , H01J29/702 , H01J2229/5682 , H01J2229/5687
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