| 摘要 |
PURPOSE:To pick up an excellent image by A/D-converting a digital signal with a bit number larger than that of an inputted digital signal in a digital electronic image pickup device and only assigning an effective extent to the input bit number after the resolution of the output of the A/D conversion is improved by means of a bit number converting means. CONSTITUTION:When, for example, the bit number of a digital signal processing section 5 is '8' (256 gradations) and that of an A/D-converting section 4a is '10' (1,024 gradations), the bit number of the section 4a has a gradation margin which is four time as large as the bit number of the section 5. Accordingly, when the margin is utilized for correcting a light quantity control error, better light quantity control becomes possible. Therefore, the target control value of an exposing quantity controller 13 is set so that, for example, an A/D output of 512 gradations can be obtained and the input signals to the processing section 5 can be used effectively. Thus an excellent image can always be picked up even when control errors occur in the device 13 and input signals. |
