Browse Prior Art Database

Copier Controls

IP.com Disclosure Number: IPCOM000086621D
Original Publication Date: 1976-Oct-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 72K

Publishing Venue

IBM

Related People

Hubbard, JH: AUTHOR [+3]

Abstract

Some convenience copiers employ a semiautomatic document feed (SADF) for transporting an original document from an entry tray to a document glass, allowing image exposure from such original and then automatically transferring the original from the glass to an exit tray. Control of such apparatus is synchronized with a transfer electrographic processor timed by an emitter wheel on a photoconductor image transfer carrier (not shown).

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Copier Controls

Some convenience copiers employ a semiautomatic document feed (SADF) for transporting an original document from an entry tray to a document glass, allowing image exposure from such original and then automatically transferring the original from the glass to an exit tray. Control of such apparatus is synchronized with a transfer electrographic processor timed by an emitter wheel on a photoconductor image transfer carrier (not shown).

When an original is placed in the entry tray of SADF, a pre-entry sensor detects its presence, sends a signal to the machine control circuits and resets the stop entry roll latch. This latch deactivates a clutch mechanism (not shown) normally driving a set of entry-aligning rollers to align the original document to the correct orientation required for entry onto the document glass. Farther forward travel is inhibited by an entry gate. When the document is properly aligned in the two required directions (forward and sideways), the entry sensor supplies an indicating signal to AND 10.

At this time (depending upon the state of the machine control circuits), AND 10 resets a time-out counter which counts AC power-line zero-voltage crossovers. This timing is simply a convenient clocking signal. When 50 or 100 msec seconds (T1) has been timed by the time-out counter, and if the entry sensor still indicates the presence of the document (this action integrates the entry sensor signal), the entry gate is opened by the open entry gate latch via AND-OR circuit 11. The open entry gate latch actuates motor M via OR 12. It also actuates the entry gate to pass the original to the document glass. Motor M moves the belt which transports the original document onto the document glass.

As the belt draws the document onto the glass, the document is stopped by the exit gate. The illustrated circuits have no sensor to inform them that the document has arrived at the exit gate. However, it is known when the document leaves the entry sensor because the sensor becomes deactivated. The entry sensor signal is subject to some mechanical instability due to the initiation of document motion.

To ensure that the original document has actually left the entry sensor, if the edge timer counts up to 100 msec, for example, without the entry sensor having reactivated once, then the document has really left the sensor. Since the time out is a function of document size, circuits (not shown) determine the time out period as a function of document size. (Short documents [narrow width] leave the entry sensor earlier than wide documents.) To further compensate for these differences, the belt is moved for a minimum time T2, exceeding the entry sensor times. Time T2 is another output of the time out counter. For longer original documents or a larger document glass, such time out times can be increased. When the belt has run for T2 seconds and the document has left the entry sensor for, at least, edge time out T4 seconds, then the belt...