Patent ID: 7567691

Claim:
A fingerprint identification system comprising: an image reading apparatus; and an identification unit that compares a picture signal of a fingerprint from said image reading apparatus with a previously obtained picture signal of the fingerprint, wherein said image reading apparatus comprises: an irradiation device adapted to irradiate a finger, a sensor provided with a plurality of pixels for detecting light from the fingerprint of said finger, and a drive circuit adapted to drive said sensor so that charge accumulation intervals of different sensor regions in said sensor are shifted with respect to each other, wherein the irradiation device is adapted to irradiate the finger with different brightness or different emitted light pulse width at the respective charge accumulation intervals, so that a scan of the sensor in a main scanning direction and light emission of the irradiation device are synchronized, and an amount of light emitted from the irradiation device during a charge accumulation interval of a first sensor region which receives light from a center area of the fingerprint of said finger is larger than an amount of light emitted from the irradiation device during a charge accumulation interval of a second sensor region which receives light from a peripheral area of the fingerprint of said finger, such that unevenness of light amounts received by the sensor which is caused by a shape of the finger is canceled and exposure conditions of the different sensor regions are substantially uniform.