Laser beam scanning device and method including light intensity adjustment
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsYoshiyuki Araki, Naoyuki Okamoto
Life of this patent
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Abstract
A laser scanning device emits a scanning laser beam which scans a predetermined surface to be scanned to form an image consisting of a plurality of pixels on the surface. The laser scanning device determines the intensity of the laser beam for each pixel of an image to be formed, and executes a feed-back control of the laser diode so that the intensity of the laser beam for each pixel accurately corresponds to the gradation level thereof.
Claims22
A laser scanning device for emitting a scanning laser beam which scans a predetermined surface to form an image consisting of a plurality of pixels on said surface, said device comprising:
- means for emitting a laser beam;
- means for modulating an intensity of the laser beam for each pixel;
- means for receiving a portion of the laser beam emitted by said emitting means, and generating an electrical current corresponding to an intensity of the received beam;
- and
- means, positioned between said emitting means and said receiving means, for regulating an intensity of said laser beam from said emitting means received by said receiving means, whereby an electrical current generated by said receiving means and an intensity of light emitted by said emitting means have a predetermined relationship.
A laser scanning device for emitting a scanning laser beam which scans a predetermined surface to form an image on said predetermined surface consisting of a plurality of pixels, said laser scanning device comprising:
- a laser diode that emits a laser beam;
- a photo diode that receives a part of the laser beam emitted by said laser diode and that generates electrical current corresponding to an intensity of the received laser beam;
- a modulator which adjusts an intensity of the laser beam for each pixel;
- and
- a light regulating member positioned between said laser diode and said photo diode, said light regulating member regulating an intensity of said laser beam from said laser diode received by said photo diode, so that the electrical current generated by the photo diode and the intensity of the light emitted by the laser diode have a predetermined relationship.
A method for compensating for errors of a photo diode that emits a laser beam employed in a laser scanning device to form an image on a surface to be scanned, said method comprising:
- providing a laser diode that emits a laser beam;
- providing a photo diode that receives a portion of the laser beam emitted by said laser diode and generates electrical current corresponding to an intensity of the beam received;
- and
- modulating an intensity of the laser beam for each pixel;
- and
- positioning a light adjusting member between the laser diode and the photo diode, the adjusting member adjusting the intensity of light incident onto the photo diode so that an electrical current generated by the photo diode and the intensity of the light emitted by the laser diode have a predetermined relationship.
Dependencies are inferred from the claim text.