| 摘要 |
PROBLEM TO BE SOLVED: To enable use of an auto iris lens in a video camera provided with a function for obtaining a wide dynamic range by changing the brightness, for each field, of an image picked up while changing shutter speeds for each imaging field. SOLUTION: A control circuit 12 reads brightness data obtained by a brightness detection circuit 9 from a signal processing circuit 7. Data of a new average value and a new brightness peak value are created from brightness data of each area by applying a correction operation such as backlight correction. A lens control voltage switching circuit 14 generates a pseudo video signal having the peak value and the average value by attaching a pulse corresponding to sink to the data through a voltage converter 13, and a video lens is controlled by the pseudo video signal. Thus, the auto iris lens can be used in the video camera provided with the function for obtaining a wide dynamic range by changing the brightness of imaged video for each field. COPYRIGHT: (C)2004,JPO
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