To provide an inner drum exposure device capable of recording stable halftone; and to provide an exposure method using the device.
The inner drum exposure device records an image on a recording medium held on the inner circumference face of a cylindrical support by scanning with a light beam deflected by the reflecting surface of a scanning means driven to rotate and modulated according to image information. The exposure device is equipped with: a light source; an optical system that passes a light beam from the light source to the scanning surface of the recording medium; a diffraction optical element that is placed on the optical path of the optical beam so as to rotate integrally with a scanning means, separates the main diffracted light in the diffracted light of the beam from unnecessary light as other diffracted light by diffracting at respective predetermined diffraction angles different from each other, and shapes the light beam to obtain a desired beam spot pattern of the main diffracted light converged onto the scanning surface of the recording medium; and an eliminating means that guides only predetermined diffracted light according to the diffraction direction of diffracted light onto the scanning surface of the recording medium and eliminates other diffracted light.
| JPS54153051A | 1979-12-01 | |||
| JPH06302010A | 1994-10-28 | |||
| JP2004145179A | 2004-05-20 | |||
| JP2005165008A | 2005-06-23 | |||
| JP2001162866A | 2001-06-19 | |||
| JP2001242414A | 2001-09-07 | |||
| JP2001215863A | 2001-08-10 |
Haruko Sanwa
Hiroshi Fukushima