| 摘要 |
PURPOSE:To improve the resolving power and the recording speed by providing recording light irradiating systems whose number is equal to the number of scanning lines required for forming one dot and providing a zoom lens, which adjusts the spot size of the optical beam emitted from each light irradiating system, on the peripheral surface of a rotating body. CONSTITUTION:A simple-constitution, small-sized, and lightweight semiconductor laser 24 is provided in a thin rotary drum 4, and this rotary drum 4 is rotated and is moved in the direction of a revolving shaft to perform two-dimensional scanning. Light irradiating systems 22 whose number is equal to the number of scanning lines required for forming one dot are provided on a line in the axial direction of the rotary drum 4. A zoom lens 20 is provided in an irradiation window 19 of the irradiating system 22 so that this lens 20 can be moved finely in the direction of the optical axis, and the zoom lens 20 is moved to adjust the spot size of the beam emitted from each light irradiating system 22 in accordance with a set dot number. Consequently, the picture quality of recording on a recording paper 16 is improved by high resolving power, and the recording speed is improved. |
