| 摘要 |
The lighting unit, a laser scanner, is controlled to provide a sequential lighting of a two-dimensional grid of different points in the plane of the finger plate. The detector has a sensor, a single photo element located above or to the side of the finger, to sense light from the lighting unit. A processing unit connects the sensor signal with a control signal from the laser scanner. The signals are processed to assign serial brightness information in the sensor signal to a location information for its grid location. The brightness of light from the finger to the sensor varies according to whether the finger is illuminated on a fingerprint line (8) or on a fingerprint ridge (6). The finger plate has a transparent plate (1) on the upper side (2) and on the upper side of the plate interior light reflected from the plate is coupled with the sensor. When the transparent plate is thin, the sensor is located on the upper side (2) or lower side of the plate, instead of at a narrow side of the plate.
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