| 摘要 |
PURPOSE: To realize a fingerprint image input device which has an automatic finger detection function and is thin, compact and inexpensive. CONSTITUTION: This device is provided with a signal generation circuit 24 supplying the finger detection signal for finger contact detection for a two-dimensional image sensor surface and a signal detection circuit 25 detecting the change of the finger detection signal responding to a finger detection. An image sensor 2A is provided with switch circuits 21 and 22 selectively connecting the one end and the other end of a bias line 15 with the signal generation circuit 24 and the signal detection circuit, respectively, in response to the supply of a control signal, and a switch control circuit 23 outputting the control signals corresponding to a finger contact detection time and a fingerprint image input time. |
