Raster data drawing apparatus for correcting image starting position
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsEtsuo Iwasaki, Takashi Okuyama
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Abstract
Disclosed is a raster data drawing apparatus, in which a reference clock pulse signal having a predetermined period is first generated, and then a plurality of delayed clock signals are generated. Phases of the plurality of delayed clock signals are shifted by a period of time which is shorter than the predetermined period. An image is formed in a main scanning direction synchronously with one of the plurality of delayed clock signals so that the starting point of the image in the main scanning direction is adjusted.
Claims7
A raster data drawing apparatus, comprising:
- means for providing raster data;
- a light source that emits a light beam;
- a scanning system that scans said light beam in a main scanning direction on an image drawing plane;
- a reference clock generator that generates a reference clock pulse signal having a predetermined period;
- a delayed clock generator that outputs a delayed clock signal representing said reference clock signal delayed by a period of time shorter than said predetermined period;
- and
- an image drawing controller, that modulates said light beam, based on said raster data in synchronism with said delayed clock signal, for each scan of said light beam in said main scanning direction.
A method for correcting for a displacement, in a main scanning direction, of an image drawing plane in relation to a reference position, in a scanning image forming system in which an image is formed on an image drawing plane, said method comprising:
- detecting a displacement, in a main scanning direction, of the image drawing plane from the reference position;
- generating a reference clock signal having a predetermined period;
- generating a plurality of delayed clock signals having a predetermined period;
- generating a plurality of delayed clock signals delayed from the reference clock signal by a plurality of periods, each period of the plurality of periods being less than the predetermined period of the reference clock signal;
- selecting one of the plurality of delayed clock signals, based on the displacement;
- and
- forming the image based on the selected one of the delayed clock signals.
Dependencies are inferred from the claim text.