发明名称 |
Contrast control wherein reference pulse detection occurs every other line period and wherein clamping occurs in remaining line periods |
摘要 |
The present invention provides a contrast control circuit capable of controlling the contrast even if the back porch is comparatively short. The contrast control circuit comprises monostable multivibrators (24, 26) which provides a background pulse and a reference pulse alternately, respectively, a switch (SW1) which clamps a video signal while the background pulse is HIGH so that the potential of the pedestal level is zero on an (N+1)th horizontal scanning line, and a switch (SW2) samples the leading edge of a reference pulse inserted in the video signal while the reference pulse is HIGH on an nth horizontal scanning line.
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申请公布号 |
US5331352(A) |
申请公布日期 |
1994.07.19 |
申请号 |
US19930099964 |
申请日期 |
1993.07.29 |
申请人 |
SONY CORPORATION |
发明人 |
UMEMURA, SHUNJI;NAKAZONO, HIROYUKI |
分类号 |
H04N5/57;G09G1/16;(IPC1-7):H04N5/57;H04N5/52 |
主分类号 |
H04N5/57 |
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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