Image forming apparatus with frequency corrector
AssigneeRicoh Company, Ltd.
InventorsTakeshi Yamakawa, Takashi Mama, Kenichi Ono, Norio Michiie
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Abstract
A scanning time after a detection signal from a first laser beam detection sensor is inputted until a detection sensor from a second laser beam detection sensor is inputted by a counter, flip-flops, a corrected write frequency f1 is computed by a control circuit from a value T1 corresponding to the measured scanning time and a function F (T1) for computing a correction factor using the basic write frequency f0 and the value T1 above and through the equation of "f1=f0.times.F (T1)", and the write clock frequency is corrected by a clock generation circuit, thus the write clock frequency being controlled according to a change in the scanning speed.
Claims22
An image forming apparatus for writing pictorial information into a photo-sensitive body using a laser beam, said image forming apparatus comprising:
- a plurality of laser beam detectors, each for detecting a laser beam moving in a main scanning direction;
- a measuring apparatus for measuring a scanning time or a number of specified clocks after one of said plurality of laser beam detectors detects a laser beam until another laser beam detector detects a laser beam;
- and
- a write frequency correcter for correcting a write clock frequency by computing a corrected write frequency f1 from a value T1 corresponding to said measured scanning time or said number of specified clocks counted by said measuring apparatus and a function F (T1) for computing a correction factor, using a basic write frequency f0 and said value T1 above as parameters in an equation of f1=f0.times.F (T1).
Dependencies are inferred from the claim text.