Optical reader

Abstract

Abstract PURPOSE:To obtain a stable and high-quality picture signal and extend the life of a light source by correcting a minute change of the white level signal due to difference of original with a white level follower circuit and correcting a considerable change due to a change in the lapse of time of the light source or the like with a driving circuit of the light source. CONSTITUTION:The reflected light from an original 1 irradiated with a fluorescent lamp 2 is reflected on a mirror 3 and is made incident to a lens 4, and the lens 4 focuses the image of the original onto a photoelectric trandsucer 5. The output of this transducer 5 is amplified as a serial signal by an amplifier 5 and is sent to a white level follower circuit 8. The circuit 8 keeps the white level signal corresponding to each picture element of the serial picture signal constant and corrects the difference of reflection factor due to the difference of original. The light from the fluorescent lamp 2 has the luminance detected by a means 10, and this luminance is converted to an electric signal and is amplified by an amplifier 11 and is converted by an A/D converter 12 and is sent to a system controller 13. This controller 13 raises the output of a driving circuit 14 by one stage if the output of the detector 10 becomes a prescribed value or smaller because of the change in the lapse of time or the like, and deterioration is displayed on a fluorescent deterioration display device 15 in case of a maximum.

Inventors

• 👤 Yoji Hoki
• 👤 陽治 伯耆
• 👤 Atsushi Shimoyama
• 👤 霜山　篤

Bibliographic Details