METHOD FOR CORRECTING JITTER OF RECORDED INFORMATION BASED ON ROTATIONAL JITTER OF DEFLECTOR FOR OPTICAL SCANNING

摘要

PURPOSE:To correct the jitter of recorded information based on the rotational jitter of a deflector for optical scanning by comparing the rotational moving time of one zone measured by actual scanning in one scanning unit with the average rotational moving time of the same zone as this zone, and adding the compared result to the output time of output data in following zones. CONSTITUTION:A slit 8a is formed so as to equally divide the rotational angle of each mirror face 1a of a polygon mirror 1 into five angles, and in an entire slit disk 8, the rotational angle of the polygon mirror 1 is equally divided into 40 angles. The correction of jitter is executed for the unit of each mirror face 1a, namely, for one scanning unit. Namely, when the deflector generates the rotational jitter in the zone between A and B, the deviation for this rotational jitter is corrected by subtracting it from a reference value in the next zone between B and C. Therefore, recording dots are decreased by prolonging time for the dot pitch of a video signal. Thus, the rotational jitter of the deflector in the zone between A and B is corrected on the video signal from B to C, and jitter is canceled at the C point.