发明名称 |
GAMMA COMPENSATING CIRCUIT |
摘要 |
A circuit having a nonlinear response characteristic provides gamma compensation to a video luminance signal and matches any desired output response curve by selecting the number of diodes connected as series-connected circuits in the compensation circuit. The relationship among the various numbers of series-connected diodes is dependent upon having a current flowing into an output circuit which is the same as a current flowing out of a collector circuit of a differential amplifier, to which the input video luminance signal is applied, and through series-connected diode circuit. These currents are maintained equal by use of a current-mirror circuit, which provides an input current to an output transistor that has in its emitter circuit one of the series-connected diode circuits, and the compensated luminance signal flows in the collector circuit thereof. The differential amplifier is stabilized and balanced by a difference amplifier connected in feedback across the collector leads of the differential amplifier in conjunction with a pedestal clamping synchronization signal and a capacitor to provide a balancing signal at the base lead of the second transistor of the differential transistor amplifier. |
申请公布号 |
DE3465563(D1) |
申请公布日期 |
1987.09.24 |
申请号 |
DE19843465563 |
申请日期 |
1984.01.06 |
申请人 |
SONY CORPORATION |
发明人 |
SATO, JOICHI;SHIONO, RYUJI;NIMURA, TSUTOMU;ISOGAWA, TOSHIAKI;SATO, MITSURU |
分类号 |
H04N5/202;(IPC1-7):H04N5/202 |
主分类号 |
H04N5/202 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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