US4632537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic apparatus
Assignee: Ricoh Co Ltd
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Filing: 1985-04-10
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Granted: 1986-12-30
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Expires: 2005-04-10
Abstract
Abstract An electrophotographic apparatus is operable selectively in an image-forming mode and a checking mode. In the checking mode, a region of a photosensitive body or drum having a uniform surface potential is developed by a developing unit at a plurality of different developing bias voltages into toner amount detecting regions.
Inventors
- 👤 Chikara Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:44
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/50; G03G15/5033; G03G15/5041
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
An electrophotographic apparatus comprising: (a) a cyclically operable photosensitive body; (b) means for forming a latent image on said photosensitive body; (c) a developing unit having a developing electrode supplied with a prescribed developing bias voltage for developing said latent image into a toner image with a two-ingredient developing agent; (d) means for transferring the toner image from said photosensitive body to a transfer sheet; (e) means for controlling the density of toner in said two-ingredient developing agent; (f) means for selectively establishing a checking mode; and (g) means for applying a plurality of different developing bias voltages to said developing electrode in said checking mode to enable said developing unit to develop a region of said photosensitive body having a uniform surface potential into toner amount detecting regions on said photosensitive body.
Claim 2
Dependent Claim
133 words
An electrophotographic apparatus comprising: (a) a cyclically operable photosensitive body; (b) means for forming a latent image on said photosensitive body; (c) a developing unit having a developing electrode supplied with a prescribed developing bias voltage for developing said latent image into a toner image with a two-ingredient developing agent; (d) means for transferring the toner image from said photosensitive body to a transfer sheet; (e) means for controlling the density of toner in said two-ingredient developing agent; (f) means for selectively establishing a checking mode; and (g) means for applying a plurality of different developing bias voltages to said developing electrode in said checking mode to enable said developing unit to develop a region of said photosensitive body having a uniform surface potential into toner amount detecting regions on said photosensitive body.
Claim 3
Dependent Claim
39 words
An electrophotographic apparatus according to claim 1, including means for transferring toner from said toner amount detecting regions to a transfer sheet for visually checking a developing ability based on the amount of toner attached to the transfer sheet.
Claim 4
Dependent Claim
27 words
An electrophotographic apparatus according to claim 1, including means for detecting the amounts of toner attached in said toner amount detecting regions to determine a developing ability.
Claim 5
Dependent Claim
15 words
An electrophotographic apparatus according to claim 3, including means for displaying the determined developing ability.
Claim 6
Dependent Claim
42 words
An electrophotographic apparatus according to claim 1, wherein said region of the photosensitive body having the uniform surface potential is developed into the toner amount detecting regions by said developing unit through switching between said developing bias voltages in said checking mode.
Claim 7
Dependent Claim
48 words
An electrophotographic apparatus according to claim 1, wherein said region of the photosensitive body having the unifrom surface potential is developed into a single toner amount detecting region a plurality of times by said developing unit through successive application of said developing bias voltages in said checking mode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |