SCANNING SPEED CORRECTIVE METHOD FOR LASER BEAM SCANNING OPTICAL SYSTEM

摘要

PROBLEM TO BE SOLVED: To deal with high speed printing and high image quality of a system by giving a phase locked loop oscillator a sample-and-hold function, respectively using a close loop, an open loop at a sampling time and a holding time and obtaining a precise and high speed synchronization control pulse. ;SOLUTION: A control system is constituted of an oscillator 27 outputting a reference clock, the phase locked loop oscillator 10 synchronizing with the frequency and phase of the reference clock and outputting a synchronization control video clock, a scanning speed corrective circuit 20 scanning speed correcting a video clock and a scanner motor control 26, etc. Then, the control system gives the phase locked loop oscillator 10 the sample-and-hold function, and uses respectively the close loop and the open loop at the sampling time and the holding time and obtains the precise and high speed synchronization control pulse. Further, this method is constituted so that the scanning speed corrective circuit 20 is provided with the correction data constituted under the function of cos²θ between the clock period and the polarization angle θof the synchronization control clock.;COPYRIGHT: (C)1997,JPO