Browse Prior Art Database

SURFACE RELIEF ELECTROMETER TYPE SCANNER

IP.com Disclosure Number: IPCOM000024721D
Original Publication Date: 1981-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 4 page(s) / 203K

Publishing Venue

Xerox Disclosure Journal

Abstract

The principal focus of this proposal is a multi-function copier where light lens copying, raster output scanning (ROS), and raster input scanning (RIS) in a single xerographic processing machine is facilitated.

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SURFACE RELIEF ELECTROMETER TYPE SCANNER
James C. Stoffel

Proposed Classification
U.S. C1. 358/294 Int. C1. H04n 1/02

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Volume 6 Number 5 September/October 1981

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SURFACE RELIEF ELECTROMETER TYPE SCANNER (con't)

The principal focus of this proposal is a multi-function copier where light lens copying, raster output scanning (ROS), and raster input scanning (RIS) in a single xerographic processing machine is facilitated.

There are primarily three techniques for exploiting a laser ROS and a xerographic processing machine to facilitate the raster input scanning function. The most simple technique is to scan the original document on a platen. This technique requires cumbersome platen covers to avoid human exposure, and is also not very panchromatic.

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    XEROX DISCLOSURE JOURNAL Volume 6 Number 5 September/October 1981

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SURFACE RELIEF ELECTROMETER TYPE SCANNER (Cont'd)

The second technique requires that one scan a developed toner image on the photoreceptor. However, the requirement that one develop the image prior to scanning sometimes yields awkward optical system designs when attempting to exploit a single laser. In addition, the development subsystem artifacts, especially in the asynchronous mode of operation, may degrade the quality of the toner image which is to be scanned. Furthermore, the surface properties of real product photoreceptor drums in the small spot reflection scanning mode are neither truely defuse "or specular reflectors" thus diminishing the signal-to-noise ratios.

The third method of capturing an image in the xerographic process relies on the measurement of discharge current in the photoreceptor as a laser scanner scans a latent image on a drum. One technique for doing this utilizes a strip capacitor to detect the discharge of the surface current in the photoconductor. This approach suffers from some problems as well: microphonics, small signal sensing with noisy environment, and readout speed limitations for other than alloy photoreceptors.

The technique proposed here is distinct from the three methods described above and attempts to provide inherently higher resolution and better signal-to-noise while still requiring only minimal additional hardware for a system having a ROS already in place.

The second purpose is to provide a high quality micro-electrometer which will enable one to measure latent xerographic imagery with a frequency response well above 10 cycles per millimeter. Furthermore, gray scale information can also be extracted from the xerographic image which is of potential value xero-radio- gr aphers.

The fundamental principal of this design is the development of a surface relief image to represent the latent, electrostatic image on a photoreceptor. Referring to Figures 1 and 2, a three layer sandwich 4 of materials in the form of a l...