US4760422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing device using single component toner
Assignee: Ricoh Co Ltd
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Filing: 1986-01-14
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Granted: 1988-07-26
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Expires: 2006-01-14
Abstract
Abstract A device for developing an electrostatic latent image includes a developing sleeve and a sponge roller which is in scrubbing contact with the sleeve. Thus, even if non-magnetic, single component toner is used, it is electrically charged due to the scrubbing action and thus electrically attracted to the developing sleeve. A doctor blade is pressed against the developing sleeve and thus the toner is formed into a thin film having sufficient charge and a predetermined thickness. As the developing sleeve further rotates, thus formed thin film is brought to a developing region where the latent image is developed by the thin film of toner. Preferably, the blade is arranged in a particular orientation with respect to the sleeve. The blade may be movably provided so as to be pressed against the sleeve by an appropriate biasing element. The sleeve and the sponge roller may be driven to rotate same or opposite in direction, as desired. The sleeve may be formed to be elastically deformable. The sleeve may be set in oscillation. The blade is preferably comprised of a copolymer of ethylene and tetrafluoroethylene.
Inventors
- 👤 Ryubun Seimiya
- 👤 Noriyoshi Tarumi
- 👤 Hiromi Demizu
- 👤 Makoto Obu
- 👤 Hidetoshi Yano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:53
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0806; G03G15/0818; G03G15/0812; G03G2215/00; G03G2215/08; G03G2215/0855; G03G2215/0866
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
210 words
A device for developing an electrostatic latent image, comprising: storing means for storing a quantity of a developer; transporting means for transporting said developer along a predetermined path which passes thorugh a developing region where said latent image is developed by said developer, said predetermined path including a curved region having a predetermined radius of curvature; supplying means for supplying said developer stored in said storing means to said transporting means to thereby cause said developer to be attracted to said transporting means electrostatically; a doctor blade located downstream of said supplying means with respect to a direction of transporting said developer by said transporting means along said predetermined path, wherein said doctor blade is pressed against said transporting means at said curved region and extends in a direction opposite to the transporting direction of said developer at a contact point between said doctor blade and said transporting means, and wherein when said radius of curvature is at least 3 mm, said doctor blade is arranged such that a separating distance between said transporting means and said blade along a straight line normal to a tangential line drawn at a point 1 mm downstream from said contact point between said transporting means and said blade is at least 0.3 mm.
Claim 2
Independent Claim
210 words
A device for developing an electrostatic latent image, comprising: storing means for storing a quantity of a developer; transporting means for transporting said developer along a predetermined path which passes thorugh a developing region where said latent image is developed by said developer, said predetermined path including a curved region having a predetermined radius of curvature; supplying means for supplying said developer stored in said storing means to said transporting means to thereby cause said developer to be attracted to said transporting means electrostatically; a doctor blade located downstream of said supplying means with respect to a direction of transporting said developer by said transporting means along said predetermined path, wherein said doctor blade is pressed against said transporting means at said curved region and extends in a direction opposite to the transporting direction of said developer at a contact point between said doctor blade and said transporting means, and wherein when said radius of curvature is at least 3 mm, said doctor blade is arranged such that a separating distance between said transporting means and said blade along a straight line normal to a tangential line drawn at a point 1 mm downstream from said contact point between said transporting means and said blade is at least 0.3 mm.
Claim 3
Dependent Claim
34 words
The device of claim 1 wherein said transporting means includes a developing sleeve which is driven to rotate in a first direction so that said radius of curvature is a radius of said sleeve.
Claim 4
Dependent Claim
56 words
The device of claim 2 wherein said supplying means includes a supply roller which is in contact with said developing sleeve and is driven to rotate to establish a scrubbing contact with said developing sleeve and to thereby cause said developer to be electrically charged at said scrubbing contact and electrostatically attracted to said developing sleeve.
Claim 5
Dependent Claim
56 words
The device of claim 3 wherein said developing sleeve includes an electrically conductive layer, a dielectric layer formed on said conductive layer, and an electrode layer formed on said dielectric layer, said electrode layer including a dielectric matrix material and a plurality of fine electrodes dispersed in said matrix material and electrically isolated one from another.
Claim 6
Dependent Claim
25 words
The device of claim 4 further comprising bias applying means for applying a predetermined bias voltage to said electrically conductive layer of said developing sleeve.
Claim 7
Dependent Claim
51 words
The device of claim 5 further comprising charge removing means disposed downstream of said developing region but upstream of said supplying means with respect to the transporting direction of said developer, said charge removing means being in contact with the peripheral surface of said developing sleeve for removing residual charge therefrom.
Claim 8
Dependent Claim
17 words
The device of claim 3 wherein said supply roller includes a sponge layer at its outermost layer.
Claim 9
Dependent Claim
28 words
The device of claim 1 wherein said blade includes a material excellent in parting characteristic with said developer at least partly where in contact with said transporting means.
Claim 10
Dependent Claim
16 words
The device of claim 8 wherein said material excellent in parting characteristic is a fluorine-containing material.
Claim 11
Independent Claim
208 words
A device for developing an electrostatic latent image with developer which is electrostatically attracted to and held on transporting means, comprising: storing means for storing a quantity of a developer; transporting means for transporting said developer along a predetermined path which passes through a developing region where said latent image is developed by said developer, said predetermined path including a curved region having a predetermined radius of curvature; supplying means for supplying said developer stored in said storing means to said transporting means, wherein said developer supplied to the transporting means is attracted thereto electrostatically and is transported thereby along a transporting direction to the developing region while remaining attracted electrostatically to the transporting means; a doctor blade having a portion pressed against the transporting means at a contact point which is located downstream of said supplying means with respect to the transporting direction, wherein said doctor blade extends in a direction away from the transporting direction from said contact point and wherein when said radius of curvature is at least 3 mm, the separation between said doctor blade and said transporting means along a straight line normal to a tangential line drawn at a point 1 mm downstream from said contact point is at least 0.3 mm.
Claim 12
Independent Claim
208 words
A device for developing an electrostatic latent image with developer which is electrostatically attracted to and held on transporting means, comprising: storing means for storing a quantity of a developer; transporting means for transporting said developer along a predetermined path which passes through a developing region where said latent image is developed by said developer, said predetermined path including a curved region having a predetermined radius of curvature; supplying means for supplying said developer stored in said storing means to said transporting means, wherein said developer supplied to the transporting means is attracted thereto electrostatically and is transported thereby along a transporting direction to the developing region while remaining attracted electrostatically to the transporting means; a doctor blade having a portion pressed against the transporting means at a contact point which is located downstream of said supplying means with respect to the transporting direction, wherein said doctor blade extends in a direction away from the transporting direction from said contact point and wherein when said radius of curvature is at least 3 mm, the separation between said doctor blade and said transporting means along a straight line normal to a tangential line drawn at a point 1 mm downstream from said contact point is at least 0.3 mm.
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) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |