Image forming apparatus using a clock signal generated by a spread spectrum clock oscillator, and a controlling method thereof

摘要

An image forming apparatus outputs a clock signal used for outputting image data, outputs first image data in accordance with the outputted clock signal, outputs second image data in accordance with a clock signal for which the output clock signal is caused to change by a spread spectrum clock oscillator circuit, calculates a logical OR of the two outputs, and outputs image data, which is the calculation result, to an image forming unit. A laser device provided in the image forming unit is controlled in accordance with the outputted image data.

主权项

1. An image forming apparatus, comprising:
a clock output circuit configured to output a clock signal which is used for outputting a video signal; a first image output circuit configured to output a first video signal in accordance with the outputted clock signal and a mask signal masking an output from another image output circuit; a second image output circuit configured to output a second video signal in accordance with a clock signal which is generated from the outputted clock signal by a spread spectrum clock generator; an AND circuit configured to calculate a logical AND of the mask signal output from the first image output circuit and the second video signal output from the second image output circuit, and to output a third video signal which is the calculation result of the logical AND; and an OR circuit configured to calculate a logical OR of the first video signal output from the first image output circuit and the third video signal output from the AND circuit, and to output, to an image forming unit, a fourth video signal which is the calculation result of the logical OR, wherein a laser device provided in the image forming unit is controlled in accordance with the fourth video signal output from the OR circuit.