Edward G O'Brien

US Patent:

40764184, Feb 28, 1978

Filed:

Apr 5, 1976

Appl. No.:

5/674021

Inventors:

Edward F. O'Brien - Northampton MA

Assignee:

The United States of America as represented by the Secretary of the Air
Force - Washington DC

International Classification:

G03B 2722

US Classification:

355104

Abstract:

A film slewing device is incorporated into a contact printer of the type in which a free running inner copy film and a driven outer master film are transported in layered contact on the surface of a free wheeling drum through a light exposure region by use of a master film drive roller and a film coupling pressure roller. The slewing device can selectively provide independent drive of the master film while holding the copy film stationary. This is accomplished by use of a thin arcuate film separating member that is conformed to the outer surface of the drum and that slides on the outer surface of the copy film. The film separating member can be slideably inserted between copy and master films in the region of light exposure. It has idling rollers on its outer surfaces to permit free passage of the outer master film. The pressure roller is disengaged when the separating member is positioned between films to prevent movement of the copy film.