EP0086455A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Developing apparatus
Assignee: Toshiba Corp
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Filing: 1983-02-09
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Granted: —
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Expires: 2003-02-09
Abstract
Abstract A developing apparatus (34) is so set as to face the developed section of the electrostatic latent image-forming plane (56) of the photosensitive drum (54), and causes a magnetic developing agent (40) to be magnetically conducted to the electrostatic latent image-forming plane (56). Further, a magnet roll is so provided as to face that portion of the electrostatic latent image-forming plane (56) of the photosensitive drum (54) which has passed the developed region, thereby adsorptively removing the unnecessary particles of the developing agent (40) which are deposited on the electrostatic latent image-forming plane (56). Therefore, the developing apparatus (34), though possessed of a relatively simple arrangement, has the advantages of suppressing the occurrence of the aforesaid tailing phenomenon, and enabling a distinct impression to be transcribed on a copy sheet with the reproducibility of fine lines prominently improved.
Inventors
- 👤 Mitsuaki Kohyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 11:23
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/095; G03G15/09
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
169 words
A developing apparatus (34) which is designed to develop an electrostatic latent image produced on an electrostatic latent image-forming surface (56) of an image carrier (54) rotating in one direction in a developing region of said image carrier (54) by means of a magnetic developing agent (40), comprising: first means (36) for generating a magnetic field, said first means being set to face said developing region to supply said magnetic developing agent (40) to that portion of the electrostatic latent image-forming surface (56) of said image carrier (54) which has been brought to said developing region, characterized by comprising: second means (60, 70 or 86) for generating a magnetic field, said second means being provided downstream of the rotating direction of said image carrier (54) in the proximity of said first means (36) to remove the unnecessary particles of said magnetic developing agent (40) which are deposited on that portion of the image carrier (54) on which said electrostatic latent image has been developed by the first means (36).
Claim 2
Dependent Claim
169 words
A developing apparatus (34) which is designed to develop an electrostatic latent image produced on an electrostatic latent image-forming surface (56) of an image carrier (54) rotating in one direction in a developing region of said image carrier (54) by means of a magnetic developing agent (40), comprising: first means (36) for generating a magnetic field, said first means being set to face said developing region to supply said magnetic developing agent (40) to that portion of the electrostatic latent image-forming surface (56) of said image carrier (54) which has been brought to said developing region, characterized by comprising: second means (60, 70 or 86) for generating a magnetic field, said second means being provided downstream of the rotating direction of said image carrier (54) in the proximity of said first means (36) to remove the unnecessary particles of said magnetic developing agent (40) which are deposited on that portion of the image carrier (54) on which said electrostatic latent image has been developed by the first means (36).
Claim 3
Dependent Claim
112 words
The developing apparatus according to claim 1, characterized in that said first means includes: a hopper for holding the magnetic developing agent; and at least one developing roll including a first magnetic roll which is provided with a plurality of magnetic poles defining a prescribed strength of a magnetic field and is rotated in one direction, and a first cylindrical sleeve which surrounds the first magnetic roll, and is partly contacted with the magnetic developing agent held in said hopper and is rotated in either direction whereby the magnetic developing agent is carried over said first cylindrical sleeve in said other direction toward the developing region, while temporarily constructing a magnetic brush.
Claim 4
Dependent Claim
48 words
The developing apparatus according to claim 2, characterized in that said second means is set in a region where the unnecessary particles of the magnetic developing agent are rolling over the electrostatic latent image-forming surface under the effect of a prescribed magnetic field created by the developing roll.
Claim 5
Dependent Claim
24 words
The developing apparatus according to claim 3, characterized in that the second means is provided with a magnet having a plurality of magnetic poles.
Claim 6
Dependent Claim
28 words
The developing apparatus according to claim 4, characterized in that said magnet is rotated, and generates a prescribed magnetic flux density lower than that of the developing roll.
Claim 7
Dependent Claim
97 words
The developing apparatus according to claim 2, characterized in that said second means includes: a second magnetic roll which has a plurality of magnetic poles and is rotated in said one direction; and a second cylindrical sleeve which surrounds said second magnetic roll, is contacted with the magnetic developing agent held in the developing agent holder, and is rotated in said one direction, whereby said magentic developing agent held in said hopper is carried over the second cylindrical sleeve in the other direction toward the developing region of the image carrier, while temporarily constructing a magnetic brush.
Claim 8
Dependent Claim
125 words
The developing apparatus according to claim 1, characterized in that the first means includes: means for holding the magnetic developing agent; and at least one developing roll which comprises; a first magnetic roll which is provided with a plurality of magnetic poles defining a prescribed strength of a magnetic field, and is rotated in one direction; and a first cylindrical sleeve which surrounds said first magnetic roll and is rotated in the other direction, and wherein the second means includes: a stationary second magnet member which is set to face the developed region of the image carrier, and is provided with a plurality of magnetic poles; and a second cylindrical sleeve which surrounds said stationary second magnetic member and is rotated in said other direction.
Claim 9
Dependent Claim
63 words
The developing apparatus according to claim 7, characterized in that the developing agent holding means comprises first and second developing agent hoppers respectively set to face the first and second cylindrical sleeves, whereby the magnetic developing agent is carried over said first and second cylindrical sleeves in said other direction toward the developing region of the image carrier, while temporarily constracting magnetic brushes.
Claim 10
Dependent Claim
24 words
The developing apparatus according to claim 7, characterized in that said developing agent-holding means comprises a hopper set to face said second cylindrical sleeve.
Claim 11
Dependent Claim
120 words
The developing apparatus according to claim 9, characterized in that said developing agent-supplying means is provided with a plate separator which is set between the first and second cylindrical sleeves, and one end of which contacts said first cylindrical sleeve and the other end of which contacts said second cylindrical sleeve, whereby said magnetic developing agent is carried from the hopper over the second cylindrical sleeve to the separator, then from said separator on to the first cylindrical sleeve, back to said separator through the developing region of the image carrier while temporarily constructing a magnetic brush, on to the second cylindrical sleeve by means of said separator, and back to said developing region, while temporarily constructing a magnetic brush.
Claim 12
Dependent Claim
176 words
The developing apparatus according to claim 9, characterized in that the second magnetic member comprises: a first magnet which is set close to the first magnetic roll and generates a prescribed magnetic flux density higher than that of said first magnetic roll; and a second magnet which is set close to said first magnetic roll as viewed from the downstream side of the first magnet rotating in the other direction, and generates a prescribed magnetic flux density higher than that of said first magnetic roll, whereby said magnetic developing agent is carried from the hopper over the second cylindrical sleeve to a point facing the first magnet, is adsorbed to the first cylindrical sleeve by the magnetic force of the first magnetic roll, is conducted over said sleeve to a point facing the second magnet through the developed region of the image carrier while temporarily constructing a magnetic brush, is adsorbed to the surface of the cylindrical sleeve, and is carried again to the developed region of the image carrier, while temporarily constructing a magnetic brush.
References Cited (Backward Citations)
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