JP2832952B

PURPOSE:To correct timing fluctuation due to the contraction/expansion of a photosensi tive material caused by temperature change by obtaining the means value of numbers of reference clocks per turn of the photosensitive material and controlling the regi-gate open timing according to the difference between the mean and a set value. CONSTITUTION:To obtain the mean value of numbers of machine clocks per turn of a belt 1, the latest four numbers are averaged, and subtracted from a reference value. The subtracted values are multiplied by a correction coefficient, and their fractions below the decimal point are omitted. The obtained numbers of clocks are subtracted from the original number of control clocks, at which timing is controlled. The number of reference clocks arising during one turn of the belt is 3764, and the correction value DELTAT of the regigate timing is calculated as follows: with respect to the circumferential length 1158mm of the belt, a rate 0.619 of a distance 716.5mm up to a tacking point is used for the correction coefficient, and DELTAT=(3764-CLKave)X0.619. Here, CLKave is the mean of the past four times, and the positive/negative of the difference from the reference clock number is the positive/ negative of the correction value as it is.