Browse Prior Art Database

DEVELOPMENT APPARATUS

IP.com Disclosure Number: IPCOM000026119D
Original Publication Date: 1990-Jun-30
Included in the Prior Art Database: 2004-Apr-05
Document File: 4 page(s) / 101K

Publishing Venue

Xerox Disclosure Journal

Abstract

A magnetic brush type development apparatus for developing electrostatic latent images, as disclosed for example in U.S. Patent 4,771,311 and references therein, may be modified to have operative and inoperative modes of development. The developer material is transported by a magnetic roller into the development zone. Developer material is attracted to the surface of the magnetic roller by a stationary magnet. A movable magnet translates from an operative position, where the magnet generates a weak magnetic field in the development zone, and a non-operative position, where the magnet generates a strong magnetic field in the development zone. In the operative position, Fig. 1, the weak magnetic field shown in Fig. 2 allows release of the developer material from the magnetic roller to allow for proper development operation. In this mode the development cannot be quickly disengaged by separating the photoreceptor and the roller because the developer would fly off the roller due to centrifugal forces. First, it has to be switched into the non-operative position. In this position, Fig. 3, the strong magnetic field shown in Fig. 4, attracts the developer material to the surface of the magnetic roller. Now the photorceptor and the roller can be separated to prevent development. Because of the strong magnetic field, the developer can not fly off the roller.

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 72% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

DEVELOPMENT APPARATUS Proposed Classification Jan Bares U.S. C1.355/251

Int. C1. G03g 15/01

72e

76

FIG. 1

76

XEROX DISCLOSURE JOURNAL - Vol. 15, No. 3 May/June 1990 155

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Page 2 of 4

DEVELOPMENT APPARATUS(C0nt'd)

FIG. 2

74

FIG. 4

156 XEROX DISCLOSURE JOURNAL - Vol. 15, No. 3 May/June 1990

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

Page 3 of 4

DEVELOPMENT APPARATUS(Cont'd)

A magnetic brush type development apparatus for developing electrostatic latent images, as disclosed for example in U.S. Patent 4,771,311 and references therein, may be modified to have operative and inoperative modes of development. The developer material is transported by a magnetic roller into the development zone. Developer material is attracted to the surface of the magnetic roller by a stationary magnet. A movable magnet translates from an operative position, where the magnet generates a weak magnetic field in the development zone, and a non-operative position, where the magnet generates a strong magnetic field in the development zone. In the operative position, Fig. 1, the weak magnetic field shown in Fig. 2 allows release of the developer material from the magnetic roller to allow for proper development operation. In this mode the development cannot be quickly disengaged by separating the photoreceptor and the roller because the developer would fly off the roller due to centrifugal forces. First,...