Method and apparatus for image forming

Abstract

Magnification data for designating a recording magnification of an overall image along a horizontal scanning direction, magnification balance data for designating the balance in the recording magnification of left and right partial image regions, and write position data for designating the timing of starting the recording of an image are inputted on the basis of results of measurement of the positions of registration marks formed at the center and both ends of an image recording range. A phase selection circuit and a LSYNC generating circuit adjust the timing of starting the recording of an image on the basis of the write position data. A detecting circuit detects an average frequency of a pixel clock and a frequency difference of partial image regions during one scanning by a laser beam, and an average-frequency control circuit and a left-right frequency difference control circuit effect control on the basis of the detected frequencies such that during one scanning by the laser beam the pixel clock frequency (oscillation frequency of VCO) changes with a scope of change corresponding to the magnification balance data by using as a reference a frequency corresponding to the magnification data.

Dependencies are inferred from the claim text.