| 摘要 |
PROBLEM TO BE SOLVED: To acquire a good screen display by easily performing proper exposure control even when excessive light is incident on a CCD. SOLUTION: A pseudo-OB signal whose level is nearly equal to a black level (OB level) is generated after varying a LOW level of a reset pulse FR within a part of a horizontal period, and a pseudo-OB clamp circuit 5 for clamping the pseudo-OB signal is provided when a clamp pulse is supplied from a clamp pulse generating circuit 6. When transfer charges overflow to an OB part after the excessive light is incident on the CCD, the charges overflowed to the OB part are discharged to a reset drain RD by phase inversion of the reset pulse FR, and the pseudo-OB level whose level is nearly equal to the black level is generated. The good screen display can be acquired without being influenced by variations of the OB level by performing the exposure control on the basis of the pseudo-OB level. COPYRIGHT: (C)2005,JPO&NCIPI
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