Light beam scanning apparatus
AssigneesKabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
InventorsKenichi Komiya, Koji Tanimoto, Daisuke Ishikawa, Koji Kawai
Life of this patent
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Abstract
A light beam scanning apparatus controls a scan position for a light beam with a first light volume so that output from a sensor is adjusted to a target value. Further, the light beam scanning apparatus controls a scan position for the light beam with a second light volume so that output from the sensor is adjusted to the target value.
Claims14
A light beam scanning apparatus to control a light beam comprising:
- a light source to generate the light beam;
- a scanning section to scan the light beam generated from said light source;
- a pair of sensors comprising a plurality of photoelectric conversion elements, wherein output from one sensor increases and output from the other sensor decreases according to a change of the light beam scan position in the vertical scan direction;
- and
- a control section which controls the light beam scan position in the vertical scan direction so that a difference between outputs from said pair of sensors becomes a target value, wherein the light beam volume output from said light source is set to a first light volume and the light beam volume output from said light source is set to a second light volume larger than said first light volume.
A light beam scanning apparatus to control a light beam comprising:
- a light source to generate the light beam;
- a scanning section to scan the light beam generated from said light source;
- a sensor which comprises a plurality of photoelectric conversion elements and outputs a signal corresponding to the light beam scan position in the vertical scan direction;
- a comparator which compares an output from said sensor with upper and lower bounds as a target value for that output;
- a control section which controls the light beam scan position in the vertical scan direction based on a comparison result from this comparator so that an output from said sensor falls between said lower bound and said upper bound;
- and
- a single setup section which supplies said comparator with said lower bound and said upper bound specified by said control section.
A light beam scanning apparatus to control a light beam comprising:
- a light source which generates the light beam having a specified diameter;
- a scanning section to scan the light beam generated from said light source;
- a pair of sensors which comprise a plurality of photoelectric conversion elements and are arranged so that said sensors are symmetrical with reference to a control target for said light beam's scan position in the vertical scan direction and an entire width in the vertical scan direction becomes smaller than the light beam's specified diameter in the vertical scan direction;
- and
- a control section which controls a peak position of a light volume for the light beam scanned by said scanning section in the horizontal scan direction based on a difference between outputs from said pair of sensors so that said peak position is aligned to said control target position.
A light beam scanning apparatus to control a light beam comprising:
- a light source to generate the light beam;
- a scanning section to scan the light beam generated from said light source;
- a sensor which comprises a plurality of photoelectric conversion elements and outputs a signal corresponding to the light beam scan position in the vertical scan direction;
- memory which stores an output value from said sensor each time said scanning section scans the light beam in the horizontal scan direction;
- and
- a determination section which determines the light beam scan position based on a plurality of output values store in this memory.
Dependencies are inferred from the claim text.