| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a device for detecting electrostatic capacity usable as a small, thin, light and low electric power consuming fingerprint image input device. SOLUTION: Detecting electrodes 11 forming an electrostatic capacity element in a space relative to a subject are charged to/discharged from a reset power line 4 to set an initial value and charges are injected therein from a capacitative element 12 charged/discharged to a bias potential and distributed among the electrodes 11. Thereby electrostatic capacity formed by the subject and the electrodes 11 is determined by outputting a signal as variation of a gate potential of a amplifying transistor 13 since holding voltage of the electrodes 11 varies according to largeness of the electrostatic capacity formed in the space relative to the subject.</p> |
