US4338019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for operating electrophotographic copying apparatus
Assignee: Hitachi Ltd
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Filing: 1980-11-20
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Granted: 1982-07-06
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Expires: 2000-11-20
Abstract
Abstract There is disclosed a method for operating an electrophotographic copying apparatus having a latent image forming unit for forming an electrostatic latent image on a recording medium, a development unit for visualizing the electrostatic latent image with a developer containing toner and carrier to produce a visible toner image, and a fixing unit for fixing the toner image. In this operation method, the development unit is raced until the amount of charge on the toner in the developer reaches a predetermined level, and thereafter a usual electrophotographic copying procedure commences, whereby reduction in density of developed images during the initial operation of the electrophotographic copying apparatus can be prevented and developed images of high quality can be obtained.
Inventors
- 👤 Isamu Terashima
- 👤 Shigeru Uchida
- 👤 Eiiji Senba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:39
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G13/00; G03G13/06; G03G13/08; G03G13/09
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
In a method for operating an electrophotographic copying apparatus having a latent image forming unit for forming an electrostatic latent images on a recording medium, a development unit for visualizing the electrostatic latent image with a developer containing toner and carrier to produce a visible toner image, and a fixing unit for fixing the toner image, said method comprising the steps of: racing said development unit prior to the normal developing operation until the amount of charge on the toner in the developer reaches a predetermined level; and thereafter commencing the electrophotographic copying procedure.
Claim 2
Dependent Claim
94 words
In a method for operating an electrophotographic copying apparatus having a latent image forming unit for forming an electrostatic latent images on a recording medium, a development unit for visualizing the electrostatic latent image with a developer containing toner and carrier to produce a visible toner image, and a fixing unit for fixing the toner image, said method comprising the steps of: racing said development unit prior to the normal developing operation until the amount of charge on the toner in the developer reaches a predetermined level; and thereafter commencing the electrophotographic copying procedure.
Claim 3
Dependent Claim
48 words
The operation method according to claim 1 wherein attainment of the amount of charge on the developer toner to the predetermined level is judged from a toner density which is detected by a toner density detector apparatus for detecting the toner density based on permeability of the developer.
Claim 4
Dependent Claim
27 words
The operation method according to claim 1 wherein said racing continues until change in charge on the toner within a predetermined time falls below a predetermined value.
Claim 5
Independent Claim
114 words
A method for operating an electrophotographic copying apparatus having a latent image forming unit for forming an electrostatic latent image on a recording medium, a development unit for visualizing the electrostatic latent image with a developer containing toner and carrier to produce a visible toner image, and a fixing unit for fixing the toner image, said method comprising the steps of: stirring the developer without consuming and feeding the developer; detecting charge on the toner in the developer as a voltage; detecting the voltage representative of the charge on the toner when it reaches a level sufficient to produce a predetermined density of images to be developed; and thereafter commencing an electrophotographic copying procedure.
Claim 6
Independent Claim
114 words
A method for operating an electrophotographic copying apparatus having a latent image forming unit for forming an electrostatic latent image on a recording medium, a development unit for visualizing the electrostatic latent image with a developer containing toner and carrier to produce a visible toner image, and a fixing unit for fixing the toner image, said method comprising the steps of: stirring the developer without consuming and feeding the developer; detecting charge on the toner in the developer as a voltage; detecting the voltage representative of the charge on the toner when it reaches a level sufficient to produce a predetermined density of images to be developed; and thereafter commencing an electrophotographic copying procedure.
Claim 7
Dependent Claim
47 words
The operation method according to claim 4 wherein attainment of the level sufficient to produce the predetermined density of developed images is judged from a toner density which is detected by a toner density detector apparatus for detecting the toner density based on permeability of the developer.
Claim 8
Dependent Claim
31 words
The operation method according to claim 4 wherein when attainment of the level sufficient to produce the predetermined density of developed images is completed, the stirring of the developer is stopped.
Claim 9
Dependent Claim
39 words
The operation method according to claim 4 wherein attainment of the level sufficient to produce the predetermined density of developed images is determined by detecting that change in the voltage within a predetermined time falls below a predetermined value.
References Cited (Backward Citations)
US3503776A
Cited
US4240375A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-05 | 1986-01-04 | 1986-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-05 | 1990-01-04 | 1990-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-05 | 1994-01-04 | 1994-07-06 | $7700.00 | Window Closed / Lapsed |