| 摘要 |
PROBLEM TO BE SOLVED: To easily and accurately detect a deviated amount of a light beam interval on a recording medium and to adjustably set it by providing a plurality of light emitting elements, and a light receiving element in which a light transmittance is continuously changed in a light emitting element arranging direction, and providing a means for controlling an arranging interval of the emitting elements so that output differences of respective beams become a predetermined value. SOLUTION: Light beams 51, 52 deflected by a deflector 3 are received by a beam positional deviation sensor 6 disposed at an end of a scanning region. Positional deviation sensing and regulating are conducted by a light emitting element interval regulating means. First, the beam 51 emitted from a light emitting unit 1 is scanned, and its intensity is detected by a light beam intensity detecting means 7. Similarly, intensity of the beam 52 is detected, and a difference is calculated by a beam intensity difference calculating means 8. This difference becomes a value proportional to two light beam interval by the element in which light transmittance is continuously changed in a width scanning direction of a front surface of a photodiode. A deviation amount of the beam from a desired width scanning direction interval is calculated based on it, and the interval is regulated by a driving means 10. |
