US4963930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing apparatus capable of preventing leakage of a developer
Assignee: Ricoh Co Ltd
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Filing: 1989-08-09
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Granted: 1990-10-16
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Expires: 2009-08-09
Abstract
Abstract A developing apparatus using a dry developer in the form of a toner. The apparatus includes a housing having an opening which is located to face a photoconductive element. A vent is formed through the housing to release a pressure being developed in the housing, while a filter closes the vent to filter out a toner cloud. A smooth air guide plate which is more than 5 millimeters wide is provided in an edge portion of the opening downstream of a developing position with respect to an intended direction of a rotation of the photoconductive element. The air guide plate is spaced apart from the photoconductive element by a distance less than 2 millimeters and serves to increase the velocity of air flowing into the housing through the opening and, thereby, prevents toner particles from being released to the outside of the apparatus.
Inventors
- 👤 Akito Yoshimaru
- 👤 Yoichiro Sugino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:39
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0942; G03G15/0896; G03G15/0898
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
187 words
A developing apparatus for developing a latent image electrostatically formed on an image carrier by using a dry developer, comprising: a housing having an opening which faces the image carrier; a developing sleeve disposed in said housing and in close proximity to said opening for transporting the dry developer being deposited thereon to a developing position between the image carrier and said opening, said dry developer developing the latent image at said developing position through said opening; a vent formed through said housing for releasing a pressure being developed in said housing; a filter closing said vent for preventing the dry developer from flowing out through said vent; and an air guide plate having a predetermined width and provided in an edge portion of said opening which is located downstream of the developing position with respect to an intended direction of movement of the image carrier at said opening of said housing, said air guide plate being spaced apart from said image carrier by a predetermined distance for sucking air through said opening, wherein the predetermined width of said air guide plate is at least 5 millimeters.
Claim 2
Dependent Claim
187 words
A developing apparatus for developing a latent image electrostatically formed on an image carrier by using a dry developer, comprising: a housing having an opening which faces the image carrier; a developing sleeve disposed in said housing and in close proximity to said opening for transporting the dry developer being deposited thereon to a developing position between the image carrier and said opening, said dry developer developing the latent image at said developing position through said opening; a vent formed through said housing for releasing a pressure being developed in said housing; a filter closing said vent for preventing the dry developer from flowing out through said vent; and an air guide plate having a predetermined width and provided in an edge portion of said opening which is located downstream of the developing position with respect to an intended direction of movement of the image carrier at said opening of said housing, said air guide plate being spaced apart from said image carrier by a predetermined distance for sucking air through said opening, wherein the predetermined width of said air guide plate is at least 5 millimeters.
Claim 3
Dependent Claim
24 words
An apparatus as claimed in claim 1, wherein said air guide plate extends over substantially an entire length of said opening of said housing.
Claim 4
Dependent Claim
25 words
An apparatus as claimed in claim 1, wherein the predetermined distance between said air guide plate and the image carrier is less than 2 millimeters.
Claim 5
Dependent Claim
143 words
A developing apparatus for developing a latent image electrostatically formed on an image carrier by using a dry developer, comprising: a housing having an opening which faces the image carrier; a developing sleeve disposed in said housing and in close proximity to said opening for transporting the dry developer being deposited thereon to a developing position; a vent formed through said housing for releasing a pressure being developed in said housing; a filter closing said vent for preventing the dry developer from flowing out through said vent; and an air guide plate having a predetermined width and provided in an edge portion of said opening, said air guide plate being spaced apart from said image carrier by a predetermined distance for sucking air through said opening, wherein the improvement comprises the predetermined width of said air guide plate being at least 5 millimeters.
Claim 6
Dependent Claim
143 words
A developing apparatus for developing a latent image electrostatically formed on an image carrier by using a dry developer, comprising: a housing having an opening which faces the image carrier; a developing sleeve disposed in said housing and in close proximity to said opening for transporting the dry developer being deposited thereon to a developing position; a vent formed through said housing for releasing a pressure being developed in said housing; a filter closing said vent for preventing the dry developer from flowing out through said vent; and an air guide plate having a predetermined width and provided in an edge portion of said opening, said air guide plate being spaced apart from said image carrier by a predetermined distance for sucking air through said opening, wherein the improvement comprises the predetermined width of said air guide plate being at least 5 millimeters.
References Cited (Backward Citations)
US4583112A
Cited
US4800411A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |