US4236485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner concentration control device
Assignee: Toshiba Corp
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Filing: 1979-08-02
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Granted: 1980-12-02
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Expires: 1999-08-02
Abstract
Abstract A toner concentration control device comprising a toner supply mechanism for supplying toner to a developing device, conveying means for conveying the developer, detecting means for optically detecting an amount of the toner adhering to a conveying surface of the conveying means and a control mechanism for controlling the toner supply mechanism based on the detected amount of toner. Thus, an amount of fresh toner corresponding to an amount of toner spent by development is supplied from the toner mechanism to a developer in the developing device to maintain a constant toner concentration in the developer.
Inventors
- 👤 Sumitaka Inukai
- 👤 Takashi Azuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:18
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0822; G03G15/0848; G03G15/0849; G03G15/0855; G03G15/0856; G03G15/0862; G03G15/0887; G03G15/0891
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
100 words
A toner concentration control device comprising: supplying means for supplying a fresh toner to a developing device for causing an electrostatic image on the surface of a photosensitive body to be developed with a developer comprising toner and carrier; conveying means having a conveying surface for conveying the developer through a developing state; detecting means for optically detecting an amount of the toner separated from the carrier of the developer and attached on the conveying surface to produce a corresponding signal; and means for controlling the supplying amount of the toner to the developing device based on said corresponding signal.
Claim 2
Dependent Claim
100 words
A toner concentration control device comprising: supplying means for supplying a fresh toner to a developing device for causing an electrostatic image on the surface of a photosensitive body to be developed with a developer comprising toner and carrier; conveying means having a conveying surface for conveying the developer through a developing state; detecting means for optically detecting an amount of the toner separated from the carrier of the developer and attached on the conveying surface to produce a corresponding signal; and means for controlling the supplying amount of the toner to the developing device based on said corresponding signal.
Claim 3
Dependent Claim
56 words
A device according to claim 1 wherein said conveying means comprises: a hollow cylindrical rotary member of non-magnetic material; and a magnetic field producing structure disposed coaxially within said hollow cylindrical rotary member, said magnetic field producing structure having a magnetic field area facing the photosensitive body and a non-magnetic field area facing said detecting means.
Claim 4
Dependent Claim
50 words
A device according to claim 1 wherein said conveying means comprises: a hollow cylindrical rotary member of non-magnetic material; a magnetic field producing structure disposed coaxially within said hollow cylindrical rotary member; and scraping means disposed adjacent to the rotary member for scraping the developer conveyed by the rotary member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |