EP0429684A1
Expired / Lapsed
EP
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Developing apparatus
Assignee: Seiko Epson Corp
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Filing: 1990-06-20
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Granted: —
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Expires: 2010-06-20
Abstract
Abstract An apparatus for developing an electrostatic latent image formed on a latent image support in an electrophotographic image recording appartus. The apparatus includes a cylindrical magnetic roller (9) having a plurality of magnetic poles and made of rare earth metal magnets. A developer (8) is directly supplied onto the magnetic roller (9), held on the surface of the magnetic roller by the magnetic field generated by the magnetic roller, and transferred by the rotation of the magnetic roller. Thus, the construction of the apparatus can be simplified and image quality can be improved.
Inventors
- 👤 Yoshiro Koga
- 👤 Tahei Ishiwatari
- 👤 Takashi Hama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 09:14
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921; H; H01; H01F; H01F7/00; H01F7/02; H01F7/0231; H01F7/0252; H01F7/0268
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
88 words
A developing device for developing electrostatic latent image patterns formed on a latent image carrier in image recording devices employing an electrophotographic process, wherein the developing device comprises a cylindrical magnetic roller made from a rare earth magnet on which a plurality of magnetic poles are formed, the developer is supplied directly to the magnetic roller, the developer is held on the surface of the magnetic roller by the magnetic field generated by the magnetic roller, and the developer being held is transported by rotating the magnetic roller.
Claim 2
Dependent Claim
25 words
The developing device of claim 1 wherein a yoke made from a soft magnetic material is laminated on the inside of the cylindrical magnetic roller.
Claim 3
Dependent Claim
25 words
The developing device of claim 1 wherein the magnetic roller is made from rare earth magnet formed by compression molding, injection molding or extraction molding.
Claim 4
Dependent Claim
19 words
The developing device of claim 1 wherein the magnetic roller is divided up into 10 or more magnetic poles.
Claim 5
Dependent Claim
19 words
The developing device of claim 1 wherein crests and troughs are formed on the surface of the magnetic roller.
Claim 6
Dependent Claim
54 words
The developing device of claim 5 wherein the crests and troughs on the surface of the magnetic roller are formed so they correspond to the pitch of the magnetic poles and the troughs are positioned on the center of the magnetic poles and the crests are positioned on the boundaries between the magnetic poles.
Claim 7
Dependent Claim
43 words
The developing device of claim 1 wherein the surface roughness of the magnetic roller is less than 40% of the volumetric mean particle diameter of the toner, which is a component of the developer, based on the JIS 10-point average roughness standard (JIS-B0601).
Claim 8
Dependent Claim
19 words
The developing device of claim 1 wherein a covering layer is formed on the surface of the magnetic roller.
Claim 9
Dependent Claim
16 words
The developing device of claim 8 wherein the covering layer is made from a conductive material.
Claim 10
Dependent Claim
15 words
The developing device of claim 8 wherein the covering layer is made from a resin.
Claim 11
Dependent Claim
16 words
The developing device of claim 8 wherein the covering layer is made from an inorganic compound.
Claim 12
Dependent Claim
33 words
The developing device of claim 1 wherein the developing device is equipped with a developer transport regulating member disposed such that it presses at least partially against the surface of the magnetic roller.
Claim 13
Dependent Claim
39 words
The developing device of claim 1 wherein the surface of the magnetic roller and the developer transport regulating member have surface contact and the end of the developer transport regulating member is not in contact with the magnetic roller.
Claim 14
Dependent Claim
24 words
The developing device of claim 1 wherein the structure of the magnetic roller comprises a thin, cylindrical shape with an essentially open space inside.
Claim 15
Dependent Claim
28 words
The developing device of claim 1 wherein the direction of rotation of the magnetic roller and the direction of rotation of the latent image carrier are the same.
Claim 16
Dependent Claim
46 words
The developing device of claim 1 wherein the direction of rotation of the magnetic roller and the direction of rotation of the latent image carrier are opposite and the circumferential speed of the magnetic roller is faster than the circumferential speed of the latent image carrier.
Claim 17
Dependent Claim
56 words
The developing device of claim 1 wherein the developing device is equipped with a magnetic field detection means for detecting the magnetic field of the magnetic roller and a developing bias voltage fluctuation means for fluctuating the developing bias voltage in sync with the alternating of the magnetic field detected by the magnetic field detection means.
Claim 18
Dependent Claim
93 words
A developing device for developing electrostatic latent image patterns formed on a latent image carrier in image recording devices employing an electrophotographic process, wherein the developing device comprises a cylindrical magnetic roller on which a plurality of magnetic poles are formed and on the surface of which crests and troughs are formed, the developer is supplied directly to the magnetic roller, the developer is held on the surface of the magnetic roller by the magnetic field generated by the magnetic roller, and the developer being held is transported by rotating the magnetic roller.
Claim 19
Dependent Claim
25 words
The developing device of claim 18 wherein a yoke made from a soft magnetic material is laminated on the inside of the cylindrical magnetic roller.
Claim 20
Dependent Claim
19 words
The developing device of claim 18 wherein the magnetic roller is divided up into 10 or more magnetic poles.
Claim 21
Dependent Claim
53 words
The developing device of claim 18 wherein crests and troughs are formed on the surface of the magnetic roller so they correspond to the pitch of the magnetic poles and the troughs are positioned on the center of the magnetic poles and the crests are positioned on the boundaries between the magnetic poles.
Claim 22
Dependent Claim
43 words
The developing device of claim 18 wherein the surface roughness of the magnetic roller is less than 40% of the volumetric mean particle diameter of the toner, which is a component of the developer, based on the JIS 10-point average roughness standard (JIS-B0601).
Claim 23
Dependent Claim
19 words
The developing device of claim 18 wherein a covering layer is formed on the surface of the magnetic roller.
Claim 24
Dependent Claim
16 words
The developing device of claim 18 wherein the covering layer is made from a conductive material.
Claim 25
Dependent Claim
15 words
The developing device of claim 18 wherein the covering layer is made from a resin.
Claim 26
Dependent Claim
16 words
The developing device of claim 18 wherein the covering layer is made from an inorganic compound.
Claim 27
Dependent Claim
33 words
The developing device of claim 18 wherein the developing device is equipped with a developer transport regulating member disposed such that it presses at least partially against the surface of the magnetic roller.
Claim 28
Dependent Claim
39 words
The developing device of claim 18 wherein the surface of the magnetic roller and the developer transport regulating member have surface contact and the end of the developer transport regulating member is not in contact with the magnetic roller.
Claim 29
Dependent Claim
24 words
The developing device of claim 18 wherein the structure of the magnetic roller comprises a thin, cylindrical shape with an essentially open space inside.
Claim 30
Dependent Claim
28 words
The developing device of claim 18 wherein the direction of rotation of the magnetic roller and the direction of rotation of the latent image carrier are the same.
Claim 31
Dependent Claim
46 words
The developing device of claim 18 wherein the direction of rotation of the magnetic roller and the direction of rotation of the latent image carrier are opposite and the circumferential speed of the magnetic roller is faster than the circumferential speed of the latent image carrier.
Claim 32
Dependent Claim
56 words
The developing device of claim 18 wherein the developing device is equipped with a magnetic field detection means for detecting the magnetic field of the magnetic roller and a developing bias voltage fluctuation means for fluctuating the developing bias voltage in sync with the alternating of the magnetic field detected by the magnetic field detection means.
Claim 33
Dependent Claim
82 words
A developing device for developing electrostatic latent image patterns formed on a latent image carrier in image recording devices employing an electrophotographic process, wherein the developing device comprises a cylindrical magnetic roller on which a plurality of magnetic poles are formed, the developer is supplied directly to the magnetic roller, the developer is held on the surface of the magnetic roller by the magnetic field generated by the magnetic roller, and the developer being held is transported by rotating the magnetic roller.
Claim 34
Dependent Claim
25 words
The developing device of claim 33 wherein a yoke made from a soft magnetic material is laminated on the inside of the cylindrical magnetic roller.
Claim 35
Dependent Claim
19 words
The developing device of claim 33 wherein the magnetic roller is divided up into 10 or more magnetic poles.
Claim 36
Dependent Claim
43 words
The developing device of claim 33 wherein the surface roughness of the magnetic roller is less than 40% of the volumetric mean particle diameter of the toner, which is a component of the developer, based on the JIS 10-point average roughness standard (JIS-B0601).
Claim 37
Dependent Claim
19 words
The developing device of claim 33 wherein a covering layer is formed on the surface of the magnetic roller.
Claim 38
Dependent Claim
30 words
The developing device of claim 37 wherein the covering layer is made from at least one type of material selected from a group comprising conductive materials, resins and inorganic compounds.
Claim 39
Dependent Claim
33 words
The developing device of claim 33 wherein the, developing device is equipped with a developer transport regulating member disposed such that it presses at least partially against the surface of the magnetic roller.
Claim 40
Dependent Claim
39 words
The developing device of claim 33 wherein the surface of the magnetic roller and the developer transport regulating member have surface contact and the end of the developer transport regulating member is not in contact with the magnetic roller.
Claim 41
Dependent Claim
46 words
The developing device of claim 33 wherein the direction of rotation of the magnetic roller and the direction of rotation of the latent image carrier are opposite and the circumferential speed of the magnetic roller is faster than the circumferential speed of the latent image carrier.
Claim 42
Dependent Claim
56 words
The developing device of claim 33 wherein the developing device is equipped with a magnetic field detection means for detecting the magnetic field of the magnetic roller and a developing bias voltage fluctuation means for fluctuating the developing bias voltage in sync with the alternating of the magnetic field detected by the magnetic field detection means.
References Cited (Backward Citations)
No citation records indexed.
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