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Patent US5357323A successfully refreshed from Google Patents.
US5357323A
Expired / Lapsed
US
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Magnetic brush charging device
Assignee: Konica Minolta Inc
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Filing: 1993-10-15
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Granted: 1994-10-18
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Expires: 2013-10-15
Abstract
Abstract An image forming machine such as a copier or a printer for developing a latent image on a photoreceptor with toner. The image forming machine includes a sleeve for charging the photoreceptor; magnetic particles for forming a magnetic brush on a surface of the sleeve; a driver for driving the sleeve so that the magnetic brush is moved; and a power applying circuit for applying an alternating current between 20 and 500 μA/cm on to a charging area between the sleeve and the photoreceptor; in which the sleeve is located in the vicinity of the photoreceptor so that the magnetic brush is in contact with the surface of the photoreceptor.
Inventors
- 👤 Satoshi Haneda
- 👤 Kunio Shigeta
- 👤 Sachie Hosokoezawa
- 👤 Masakazu Fukuchi
- 👤 Shizuo Morita
- 👤 Hiroyuki Nomori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:50
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0208; G03G15/0241; G03G2215/00; G03G2215/02; G03G2215/021; G03G2215/022
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
93 words
An image forming apparatus for developing a latent image on a photoreceptor with toner, comprising: sleeve means for charging the photoreceptor; magnetic particles for forming a magnetic brush on a surface of said sleeve means; driving means for moving said magnetic brush; and power applying means for applying an alternating current between 20 and 500 μA/cm onto a charging area between said sleeve means and said photoreceptor; wherein said sleeve means is located in a vicinity of said photoreceptor so that said magnetic brush is in contact with a surface of said photoreceptor.
Claim 2
Dependent Claim
93 words
An image forming apparatus for developing a latent image on a photoreceptor with toner, comprising: sleeve means for charging the photoreceptor; magnetic particles for forming a magnetic brush on a surface of said sleeve means; driving means for moving said magnetic brush; and power applying means for applying an alternating current between 20 and 500 μA/cm onto a charging area between said sleeve means and said photoreceptor; wherein said sleeve means is located in a vicinity of said photoreceptor so that said magnetic brush is in contact with a surface of said photoreceptor.
Claim 3
Dependent Claim
24 words
The apparatus of claim 1, wherein a contacting length L(cm) of said magnetic brush onto said surface of said photoreceptor satisfies: 0.2 cm≦L≦1 cm.
Claim 4
Dependent Claim
24 words
The apparatus of claim 2, wherein said contacting length L(cm) and a gap D(cm), formed between said sleeve means and said photoreceptor, satisfy: 1≦L/D≦10.
Claim 5
Dependent Claim
25 words
The apparatus of claim 1, wherein an amount W of said magnetic particles in said charging area is between 10 and 500 mg/cm 2 .
Claim 6
Dependent Claim
26 words
The apparatus of claim 4, wherein said amount W(mg/cm 2 ) and a gap D(cm), formed between said sleeve means and said photoreceptor, satisfy: 300≦W/D≦3000 mg/cm.sup.3.
Claim 7
Dependent Claim
24 words
The apparatus of claim 5, wherein a contacting Length L(cm) of said magnetic brush onto said surface of said photoreceptor satisfies: 0.2 cm≦L≦1 cm.
Claim 8
Dependent Claim
24 words
The apparatus of claim 1, wherein a relative volume ratio Q of said magnetic particles in said charging area is between 20 and 40%.
Claim 9
Dependent Claim
26 words
The apparatus of claim 7, wherein said relative volume ratio Q and a gap D (cm), formed between said sleeve means and said photoreceptor, satisfy: 0.4≦Q×D≦20.
Claim 10
Dependent Claim
24 words
The apparatus of claim 8, wherein a contacting Length L(cm) of said magnetic brush onto said surface of said photoreceptor satisfies: 0.2 cm≦L≦1 cm.
References Cited (Backward Citations)
US4174903A
Cited
JPS59133569A
Cited
JPS63187267A
Cited
JPH0421873A
Cited
EP0474220A2
Cited
JPH04116674A
Cited
JPH05100545A
Cited
JPH05127490A
Cited
JPH05134517A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-17 | 1998-04-18 | 1998-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-17 | 2002-04-18 | 2002-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-17 | 2006-04-18 | 2006-10-18 | $7700.00 | Window Closed / Lapsed |