Browse Prior Art Database

Single Sensor Copy Length Control

IP.com Disclosure Number: IPCOM000051056D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Clark, WD: AUTHOR [+3]

Abstract

When copying book pages or other sources that are shorter than the copy sheets, the imaging level illumination (for making copies) causes the portion of the copy sheet beyond the trailing edge of the source to be discolored, black, or mottled.

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Single Sensor Copy Length Control

When copying book pages or other sources that are shorter than the copy sheets, the imaging level illumination (for making copies) causes the portion of the copy sheet beyond the trailing edge of the source to be discolored, black, or mottled.

To eliminate this problem, a sensor could be placed in the vicinity of the photo-optics to detect passage of the trailing edge for turning off or changing the illumination to the cleaning level. This, however, would require an additional sensor.

The addition of such a sensor can be avoided by using the entry switch in a dual mode. Initially, the entry switch detects the insertion of the original source and initiates the necessary functions, such as copy sheet feed and so on, for producing copies.

After the copy functions have begun, the entry switch is periodically sensed, as shown in the flowchart. As long as the switch is sensed in the closed position, a count value is reset to zero and the illumination maintained at the imaging level.

When the switch is sensed open, the counter value is tested. If it is less than M, the counter is incremented and the illumination is maintained at the imaging level, When the count is equal to M, the illumination is changed to and maintained at the cleaning level (or turned off). The value of M is determined according to

M = d/vT where v = linear velocity of source, T = sampling period,

d = distance between switch and photo-optics, and

M = number of sampli...