System for generating clock pulse which the number of pulses outputted within a predetermined time period is based on the number of calculated delay stages

Abstract

An image forming device scans in a main scanning direction in synchronization with dot clock pulses for each scanning line to form an image; a basic clock pulse generator generates basic clock pulses with a predetermined interval; a delayed clock pulse generator generates a group of plural delayed clock pulses having different phases respectively; a synchronism detector detects at least two delayed clock pulses synchronizing with an index signal from the plural delayed clock pulses; a calculating section calculates a number of delay stages existing within a given time period based on the two synchronizing delayed clock pulses; and a clock pulse controller selects delayed clock pulses sequentially delayed from the synchronizing delayed clock pulse within a predetermined time period based on the calculated number of delay stages to control a number of clock pulses outputted as the dot clock pulses during the predetermined time period.