| 摘要 |
PURPOSE:To correct and reduce variance in write-in width and a shift in write- out position due to temperature by controlling a beam according to the temperature detection signal from a temperature detecting means. CONSTITUTION:A beam detecting means detects the arrival of a deflected beam at a specific position from a deflecting means which deflects a beam generated by a beam generating means and then outputs a beam detection signal, and a beam as an image signal begins to be modulated after a specific time based upon the beam detection signal from the beam detecting means. In this case, the temperature detecting means 32 detects the temperature nearby a beam scanning part and a beam control means A controls the beam according to the temperature detection signal from the temperature detecting means 32. For example, a frequency division ratio calculating circuit 31 varies the frequency division ratio of a frequency dividing circuit according to the temperature of an optical unit detected by, for example, the optical unit temperature detecting means 32 to obtain an image clock corresponding to temperature variation. Consequently, the variation in image write-out width and a shift in image write-out position are corrected and reduced.
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