| 摘要 |
PURPOSE:To use only part of a large-capacity sensor at a period shorter than the minimum scanning period of a photoelectric converting circuit by controlling to turn off a clock voltage impressed to a CCD shift register for a sufficiently long time as compared with the life of a carrier. CONSTITUTION:Clock gates 13 and 14 stop shift clocks phi1 and phi2 of the CCD shift register 4 for a section TC with a timing signal phi0. The length of this stop time TC is set much longer than the life of a carrier in the shift register to eliminate transfer charges remaining in the register 4. Consequently, when only elements a quarter as many as elements of the CCD sensor from the head are used, a signal is led out at a period about one third as short as before. |
