Laser picture recording device

Abstract

Abstract PURPOSE:To exert no influence on the generation timing of a picture write start signal even if a laser output drops by controlling a threshold level basing on a peak level of a laser output detected at every one scanning of a laser beam. CONSTITUTION:A beam detector 23 is placed on a path of a laser beam near the axis end of a photosensitive drum 22. The detector 23 detects a passing beam at every scanning of a beam and generates a reference signal for starting the scanning. A peak value is held by a peak holding circuit 25 from an amplifier 24, and an output holding time is set sufficiently longer than a scanning period of the beam. Divided voltage VR of resistances R1, R2 is applied as reference voltage (threshold level) to a negative input terminal of a comparator 26, and is compared with an output from the amplifier, which is inputted to a positive input terminal. A pulse signal is inputted to a driver 18 from the comparator 26 and is used for generating a reference signal for determining the write scanning start timing by the laser beam.

Inventors

• 👤 Shinsuke Funaki
• 👤 信介 舟木

Bibliographic Details