LASER SCANNING MECHANISM WITH SCANNING SPEED UNEVENNESS IMPROVING FUNCTION AND ELECTROPHOTOGRAPHIC IMAGE FORMING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an image of good quality free of color slurring and density unevenness among respective colors despite of fluctuation in relative scanning speed among the reflection surfaces of a polygon mirror resulting from manufacture errors of the respective surfaces and the precision of an f-θ lens. SOLUTION: This laser scanning mechanism has a PROM 2 to which measurement data obtained by measuring the time needed for laser beam to pass through a measurement section of a certain distance at respective points on the scanning line of the laser beam by the surfaces of the polygon mirror in an LD unit 1 are inputted as data (surface data) characteristic of the unit, and converts the data into frequency data by a CPU 3 and converts the frequency of VIDEO CLOCK by a frequency conversion part 5.