Photocopier scanning drive system

US4426149A · kind A · utility

Assignee

• Gestetner Manufacturing Limited · GB

Inventors

• Klaus Kuemmel · Gießen, DE
• Gerhard Klapettek · Gießen, DE
• Siegfried Schneider · Erlangen, DE

Key dates

• Filing date: Nov 30, 1981
• Grant date: Jan 17, 1984
• Expiry date: Nov 30, 2001

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S388/915
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A photocopier scanning system has a scanning member (which may be the scanning lamp, a scanning mirror, a scanning slit, or a document carrier) on a scanning system powered by a d.c. drive motor synchronized to the rotation of the a.c. main drive motor for the other components of the photocopier. A variable programmer using a phase locked loop control circuit including pulse encoders slaved to the motors maintains strict synchronization between the scanning drive motor and the main drive motor with an appropriate proportionality dependent upon the image magnification/reduction ratio of the photocopier. The optical system may include a movable zoom lens element which gives infinitely variable selection of the magnification/reduction ratio, and which can readily be connected to the programmer to achieve an infinitely variable proportionality between the speeds of the scanning drive motor and the main drive motor to suit any such magnification/reduction ratio. Also the output of the exposure lamp is variable in accordance with the magnification/reduction ratio.