Browse Prior Art Database

COLOR PRINTER EMPLOYING FIDUCIAL MARK FOR REGISTRATION CORRECTION

IP.com Disclosure Number: IPCOM000026724D
Original Publication Date: 1993-Jun-30
Included in the Prior Art Database: 2004-Apr-06
Document File: 4 page(s) / 192K

Publishing Venue

Xerox Disclosure Journal

Abstract

It is commonly known to sense variations in the velocity and position of a photoreceptor within an electroreprographic apparatus in order to control the exposure of the electrostatic latent image in response to such variations. For example, U.S. Patent No. 4,349,847 to Traino (Issued Sept. 14, 1982) and the disclosure 'minter Motion Compensation," Xerox Disclosure Journal, Vol. 14, No. 2, p. 85 (MarcWApril1989) illustrate methods by which the exposure of the image is regulated in response to variations in the motion of the photoreceptor. Moreover, as process requirements for electroreprographic printers and copiers become more stringent, as for example in multicolor printing machines, the need for highly accurate and responsive controls becomes more apparent. In the single-pass multicolor printing environment, where two or more images are developed on top of one another prior to transfer to an output medium, there is a need to register subsequent images within a tolerance of 0.1 millimeter of the nominal location in order to achieve acceptable output

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 51% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

COLOR PRINTER EMPLOYING Proposed Classification FIDUCIAL MARK FOR US. C1.355/233 REGISTRATION CORRECTION
G03G Int. Kenneth R. Ossman Cl. 15/28

XEROX DISCLOSURB JOURNAL - Vol. 18, No. 3 May/June 1993 257

[This page contains 1 picture or other non-text object]

Page 2 of 4

COLOR PRINTER EMPLOYING FIDUCIAL MARK FOR REGISTRATION CORRECTION (Cont'd)

It is commonly known to sense variations in the velocity and position of a photoreceptor within an electroreprographic apparatus in order to control the exposure of the electrostatic latent image in response to such variations. For example, U.S. Patent No. 4,349,847 to Traino (Issued Sept. 14, 1982) and the disclosure 'minter Motion Compensation," Xerox Disclosure Journal, Vol. 14, No. 2, p. 85 (MarcWApril1989) illustrate methods by which the exposure of the image is regulated in response to variations in the motion of the photoreceptor. Moreover, as process requirements for electroreprographic printers and copiers become more stringent, as for example in multicolor printing machines, the need for highly accurate and responsive controls becomes more apparent. In the single-pass multicolor printing environment, where two or more images are developed on top of one another prior to transfer to an output medium, there is a need to register subsequent images within a tolerance of 0.1 millimeter of the nominal location in order to achieve acceptable output

Acordingly, the present disclosure is directed toward a method for achieving the required registration of multicolor images on a photoreceptor. As partially depicted in the figure, a two color image may be developed on photoreceptor 12 as it travels in the process direction indicated by arrow 14. As the charged surface of photoreceptor 12 passes beneath exposure station A, an electrostatic latent image, depicted generally by reference numeral 18, is produced on the charged surface by exposing the surface to a light source at station A. The light source employed may be an LED imaging bar, a scanning laser beam, or any similar source which can be modulated in response to a stream of image signals to selectively discharge portions of the photoreceptor. Once the electrostatic image is produced, it is developed at developing station B, which may employ a commonly known brush-type development system to develop the image with a toner of a first color. After passing development station B, the electrostatic latent image becomes a developed image, as represented by reference numeral 20.

quality.

Subsequently, a second image is deposited over the first image by repeating the aforedescribed process. Thus, a second toner image, presumably having a toner color different than the first color, would be deposited over the first developed image. Exposure of the second image would be carried out at exposure station C in the figure.

Registration of the second image with respect to the existing image is accomplished using a feedback control...