| 摘要 |
PURPOSE:To form an image of stable density without increasing the output of a laser output source by providing a plurality of laser beam generating means, and a scanning optical system for scanning a plurality of laser beams output therefrom on the different positions of a thermosensible recording material. CONSTITUTION:Laser beams L1 to L3 output from laser beam generators 12a to 12c are guided to a polygon mirror 20 via a cylindrical lens 16 and a reflecting mirror 18 with a prescribed angle difference of theta. At this time, the mirror 20 rotates at high speed and the beams L1 to L3 reflected on a reflecting surface are guided to a thermosensible recording material S via a ftheta lens 22 and the lens 16 and mainly scans the material S in the direction of A which is subsidiarily scanned and carried in the direction of B. Since the beams L1 to L3 are output with an angle difference of thetafrom the beam generators 12a to 12c, they scan different positions with respect to the main scanning direction of the material S. With time difference T1 between the beam L2 and the beam L1, the beam L2 reaches a pixel a1 to heat the material S whose temperature is being lowered with intensity I in order to maintain the same temperature. Thus, a blackening reaction time can be maintained and an image of stable density can be obtained. |
