| 摘要 |
PURPOSE:To cope with uneven speed of scanning, by turning off a switch for precharging with a position sensor output signal for a prescribed time and reading a signal of a photodetector, in a solid-state sensor using a linear image sensor. CONSTITUTION:A control circuit CONT sets a precharge pulse phiP to a low level with a signal S from a sensor detecting positions of equal distance from a mechanical sub-scanning mechanism and turns off FETQP1 QPn, and the stored charge is discharged with the precharged charge and carriers of optical pumping through recombination at photo diodes D1-Dn, a readout pulse phiR goes to high level at the end of the prescribed time T, FETQR1-QRn are turned on and a picture element data is read in a CCD shift register. After the precharge at the next pulse phiP, a video signal VIDEO is outputted with a shift clock phiS. Although the precharge time is changed in response to uneven sub-scanning mechanical speed, the photoelectric conversion time can be made constant with the prescribed period T. |
