CCD DRIVE CIRCUIT AND IMAGE SCANNER USING THE CCD DRIVE CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent overvoltage from being applied to a signal processing IC, by generating a CCD output signal noise immediately after power-on at the timing, when the offset voltage of a coupling capacitor is low.;SOLUTION: This image scanner has a CCD3 that outputs an analog signal as image data by optically forming the image of a document to be scanned on an image pickup device, a driver for activating the corresponding CCD and a pulse generator that input clocks to the CCD, and the analog signal from the CCD3 is input to a signal processing IC5 via a coupling capacitor 4. At least one of the pulses to be input to the CCD3, for example, either the RS pulse or CP pulse with the signal level fixed to High or Low is raised up to a certain interval immediately after the power-on, and after the offset voltage of the coupling capacitor drops and stays at a low volatge level, the pulse is raised.;COPYRIGHT: (C)2007,JPO&INPIT