Browse Prior Art Database

REDUCTION MECHANISM WITHOUT HOME SENSORS

IP.com Disclosure Number: IPCOM000026641D
Original Publication Date: 1993-Feb-28
Included in the Prior Art Database: 2004-Apr-06
Document File: 2 page(s) / 55K

Publishing Venue

Xerox Disclosure Journal

Abstract

Reduction mechanisms in zoom copiers usually incorporate one or two home sensors in order to initialise the position of the lens and mirror set which adjusts the conjugate length for different magnifications.

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XEROX DISCLOSURE JOURNAL

REDUCTION MECHANISM WITH- Proposed Classification OUT HOME SENSORS US. C1.355/055
J. A. MacAndrew Int. C1. G03b 27/52

Reduction mechanisms in zoom copiers usually incorporate one or two home sensors in order to initialise the position of the lens and mirror set which adjusts the conjugate length for different magnifications.

The present invention proposes to position stepper driven zoom lenses and mirrors, without sensors and switches, by first initialising their positions against fixed stops, and then driving them through predetermined numbers of
steps for accurate positioning.

Each component to be initialised is driven to one end of its travel where it comes into contact with a hard stop in a known position. Since a stepper motor may be safely stalled, enough steps are given to each component to ensure that it has been driven firmly against the hard stop. Any magnification may then be selected by driving the components a previously computed number of steps away from the hard stop.

XEROX DISCLOSURE JOURNAL - Vol. 18, No. 1 January/February 1993 33

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34 XEROX DISCLOSURE JOURNAL - Vol. 18, So. 1 .January/February 1993

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