Browse Prior Art Database

Copier Mask

IP.com Disclosure Number: IPCOM000083684D
Original Publication Date: 1975-Jul-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 21K

Publishing Venue

IBM

Related People

Baumberger, JG: AUTHOR

Abstract

It is desirable in some applications to provide a mask for a copier, which insures that the masked area will appear as white or whiter on the copy than a selected area of a document copied in the unmasked area. It is also desirable to provide a hard, uninterrupted surface over the mask which prevents mask damage and permits smooth movement of paper over the copy window, without paper "hanging up" on edges of the mask.

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Copier Mask

It is desirable in some applications to provide a mask for a copier, which insures that the masked area will appear as white or whiter on the copy than a selected area of a document copied in the unmasked area. It is also desirable to provide a hard, uninterrupted surface over the mask which prevents mask damage and permits smooth movement of paper over the copy window, without paper "hanging up" on edges of the mask.

In the copying process, the density level of a copy is determined in part by the amount of reflected light returned from the surface of a document being copied. This permits copying printing as black (less light reflected) while copying the surrounding area as white.

Varying parameters such as light intensity, toner mix concentration, and voltage potential on the toner as it leaves the developer allows shifting the process, so everything is copied darker (white areas on the original become gray on the copy) or lighter (dark areas on the original become gray on the copy).

Basically, as shown in the cross-sectional view, the mask comprises a sheet 1 of material having diffuse reflection properties similar to white bond paper. This material is deposited or otherwise affixed on a clear glass substrate 3 in a unique patter (mask) and a cover glass 5 added over top of the mask material 1. Light transmission through glass is imperfect and losses occur in the material and at the surfaces. Since light reflected from the copy must pass through two...