Browse Prior Art Database

Copier Optics Correction

IP.com Disclosure Number: IPCOM000046590D
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Fowler, RL: AUTHOR

Abstract

A full-frame illuminating copier, having a variable-opacity film located at the document glass (i.e., at the object plane), the opacity being tailored such that uniform reflected illumination exists at the copier's photoconductor (i.e., at the image plane).

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 60% of the total text.

Page 1 of 1

Copier Optics Correction

A full-frame illuminating copier, having a variable-opacity film located at the document glass (i.e., at the object plane), the opacity being tailored such that uniform reflected illumination exists at the copier's photoconductor (i.e., at the image plane). This film is produced from photographic film by a process of (1) placing the film, in its unexposed state, at the image plane, (2) placing an all- white document at the object plane, (3) flash-illuminating the all-white document to thereby expose the film, (4) developing the film, to thereby produce a negative- image which is transparent only at the region(s) of the image plane which received the least amount of light during step (3), and which exhibits varying degrees of opacity in its other regions, dependent upon the pattern of illumination of the image plane achieved during step (3), and (5) attaching this developed film to the document glass, so that all documents are subsequently illuminated through this film, during copying of the documents. This process corrects for loss of illumination intensity as light passes through the edges of a lens. In addition, this process corrects illumination nonlinearities which may be caused by other optical system components, such as, for example, uneven illumination by the flash lamps. This variable-opacity film is tailored to do its job by the use of a photographic-type film which is exposed to light by placing the film at the copier's image pl...