PURPOSE: To improve the picture output speed in case of output of large-size characters by controlling a light shielding area of a light shielding member in accordance with variation of picture element recording pitch length to control the exposure distribution on a photosensitive body.
CONSTITUTION: A character size selecting device 36 selects orinary-size characters or large-size characters, and its information is transmitted to a light shielding plate controller 40, a photosensitive body moving speed setting device 38, and a reference signal generator 34. Then, an aperture part formed with two light shielding plates 28a and 28b is controlled to a length H corresponding to the character size. The photosensitive body moving speed is set to a speed corresponding to the character size, and the deviation between this set speed and the actual photosensitive body moving speed detected by a photosensitive body moving speed detector 33 is fed back to a photosensitive body moving speed controller 39 to control the moving speed to a fixed speed. Thus, a proper exposure distribution is given onto the photosensitive body to improve the picture output speed in case of output of large-size characters.
| JP2003127463 | LASER SCANNING UNIT |
| JPS6134135 | [Title of the device] Liquid crystal shutter |
OZAWA YASUHIRO
TACHIKAWA MASAICHIROU
