| 摘要 |
An image reading device includes a processing circuit having a clamp unit that matches an offset potential of an inputted analog image signal to a predetermined value, a processing unit that subjects an analog image signal obtained from the clamp unit to analog processing, and a converting unit that converts a processed analog image signal to a digital image signal. A control unit for controlling the processing circuit includes a switching unit that switches a main scanning line period of a charge coupled device and outputs analog image signals using a number of reading speeds, and a changing unit that changes a clamp period depending on the main scanning line period. |
