Browse Prior Art Database

NOVELTY FILTER COPY QUALITY DETECTOR

IP.com Disclosure Number: IPCOM000027123D
Original Publication Date: 1995-Jun-30
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 96K

Publishing Venue

Xerox Disclosure Journal

Abstract

This disclosure proposes the concept that the photorefractive effect exhibited by crystals of barium titanate and other materials having similar photorefractive properties, can be applied to a xerographic process for the urpose of detecting a copy quality failure in a rapid and reliable manner. &uch a failure can be caused by any one of a number of subsystems in a xerographic system.

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XEROX DISCLOSURE JOURNAL

NOVELTY FILTER COPY QUALITY Proposed Classification DETECTOR U.S. C1.252/301.16 Ronald E. Godlove Int. C1. C09k 11/06

This disclosure proposes the concept that the photorefractive effect exhibited by crystals of barium titanate and other materials having similar photorefractive properties, can be applied to a xerographic process for the urpose of detecting a copy quality failure in a rapid and reliable manner. &uch a failure can be caused by any one of a number of subsystems in a xerographic system.

A basic knowledge of the action and behavior of photorefractive elements is required for an understanding of the present disclosure. Reference is made to the article titled "The Photorefractive Effect" by David M. Pepper, Jack Feinberg, and Nicolai V. Kukhtarev, in Scientific American, October 1990, for such information.

Basically, a photorefractive crystal can be exposed by the image of the original to be copied in a light lens system, or by the image outputted from a ROS. The crystal is able to "remember" that image by semi-permanently altering its index of refraction as a function of how much light was shown onto any given location of the same image. This response of such a crystal can be exploited as a novelty filter, i.e. a filter which transmits only such portions of an image that change. Thus, if such a photorefractive filter is exposed alternatingly to an image of the original to be copied, and to the image of copy output of the xerographic process, the arrangements of the novelty filter employing a photorefractive filter...