Light-beam scanning type image reader

摘要

The number of pixels in a horizontal scanning direction and the number of pixels in a vertical scanning direction are computed by use of a calibration sheet. The cycle of a first clock pulse which is generated by a first clock generation section is computed by a clock-cycle computation section so that the computed number of horizontal pixels becomes equal to a desired number of horizontal pixels. Similarly, the cycle of a second clock pulse which is generated by a second clock generation section is computed by the clock-cycle computation section so that the computed number of vertical pixels becomes equal to a desired number of vertical pixels. The computed cycles of the first and second clock pulses are stored in a clock-cycle storage section. When reading a sheet from which an image is read out, a drive-clock control section controls the first and second clock generation sections, based on the stored clock cycles.