US5038174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus having a ventilated image forming unit
Assignee: Canon Inc
•
Filing: 1990-08-30
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Granted: 1991-08-06
•
Expires: 2010-08-30
Abstract
Abstract An image forming apparatus has an image forming unit which is detachably mounted in the stationary main part of the apparatus. The unit includes an image carrier with a photosensitive layer, a charging device capable of electrostatically charging the image carrier in contact therewith, and a housing supporting the image carrier and the charging device and provided with an exposure opening. An air flow is positively formed such that, with the image forming unit mounted in a predetermined mounting portion in the apparatus, air flows from regions near both ends of the image carrier towards the exposure opening past a region where the charging device contacts the image carrier. With this arrangement, ozone generated in the image forming unit due to operation of the contact type charging device is efficiently carried away from the image forming unit, thus eliminating generation of image defects attributable to presence of ozone and other discharge products.
Inventors
- 👤 Junichi Kato
- 👤 Masahiro Goto
- 👤 Koichi Suwa
- 👤 Hideyuki Yano
- 👤 Takahiro Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:27
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/16; G03G21/18; G03G21/1803; G03G21/1814; G03G21/20; G03G21/206; G03G2221/00; G03G2221/16; G03G2221/1645; G03G2221/1669; G03G2221/1693; G03G2221/18; G03G2221/183
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
109 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions near both longitudinal ends of said image carrier towards said exposure opening along a region where said charging means contacts said image carrier.
Claim 2
Dependent Claim
109 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions near both longitudinal ends of said image carrier towards said exposure opening along a region where said charging means contacts said image carrier.
Claim 3
Dependent Claim
22 words
An image forming apparatus according to claim 1, wherein said means for generating a flow of air comprises a suction ventilation fan.
Claim 4
Dependent Claim
36 words
An image forming apparatus according to claim 1, wherein said charging means comprises a rotary charging member in rolling contact with said image carrier, and means for applying a predetermined voltage to said rotary charging member.
Claim 5
Dependent Claim
35 words
An image forming apparatus according to claim 1, wherein said charging means comprises a blade type charging member contacting said image carrier, and means for applying a predetermined voltage to said blade type charging member.
Claim 6
Dependent Claim
44 words
An image forming apparatus according to any one of claims 1, 2, 3 or 4, wherein said exposure opening formed in said housing of said image forming unit enables a latent image to be formed on said image carrier through a light exposure operation.
Claim 7
Dependent Claim
34 words
An image forming apparatus according to claim 1, wherein said image forming unit further comprises developing means for forming a developed image on said image carrier, and cleaning means for cleaning said image carrier.
Claim 8
Dependent Claim
121 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, developing means for forming a developed image on said image carrier, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between the inner surfaces of said housing of said image forming unit and both longitudinal ends of said developing means towards said exposure opening.
Claim 9
Dependent Claim
121 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, developing means for forming a developed image on said image carrier, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between the inner surfaces of said housing of said image forming unit and both longitudinal ends of said developing means towards said exposure opening.
Claim 10
Dependent Claim
21 words
An image forming apparatus according to claim 7, wherein said means for generating a flow of air comprises a ventilation fan.
Claim 11
Dependent Claim
36 words
An image forming apparatus according to claim 7, wherein said charging means comprises a rotary charging member in rolling contact with said image carrier, and means for applying a predetermined voltage to said rotary charging member.
Claim 12
Dependent Claim
35 words
An image forming apparatus according to claim 7, wherein said charging means comprises a blade type charging member contacting said image carrier, and means for applying a predetermined voltage to said blade type charging member.
Claim 13
Dependent Claim
90 words
An image forming apparatus according to claim 10, wherein said blade type charging member is held in contact with said image carrier such that the distance between said blade type charging member and said image carrier progressively increases in the direction of movement of the image-bearing surface of said image carrier, and wherein said flow of air is formed such that the air flows through regions between the inner surfaces of said housing of said image forming unit and the adjacent surfaces of said developing means towards said exposure opening.
Claim 14
Dependent Claim
45 words
An image forming apparatus according to any one of claims 7, 8, 9, 10 or 11, wherein said exposure opening formed in said housing of said image forming unit enables a latent image to be formed on said image carrier through a light exposure operation.
Claim 15
Dependent Claim
18 words
An image forming apparatus according to claim 7, wherein said image forming unit further comprises a cleaning means.
Claim 16
Dependent Claim
117 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, cleaning means for cleaning said image carrier, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between the inner surfaces of said housing of said image forming unit and both longitudinal ends of said cleaning means towards said exposure opening.
Claim 17
Dependent Claim
117 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, cleaning means for cleaning said image carrier, and a housing supporting said image carrier and said charging means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between the inner surfaces of said housing of said image forming unit and both longitudinal ends of said cleaning means towards said exposure opening.
Claim 18
Dependent Claim
21 words
An image forming apparatus according to claim 14, wherein said means for generating a flow of air comprises a ventilation fan.
Claim 19
Dependent Claim
36 words
An image forming apparatus according to claim 14, wherein said charging means comprises a rotary charging member in rolling contact with said image carrier, and means for applying a predetermined voltage to said rotary charging member.
Claim 20
Dependent Claim
35 words
An image forming apparatus according to claim 14, wherein said charging means comprises a blade type charging member contacting said image carrier, and means for applying a predetermined voltage to said blade type charging member.
Claim 21
Dependent Claim
90 words
An image forming apparatus according to claim 17, wherein said blade type charging member is held in contact with said image carrier such that the distance between said blade type charging member and said image carrier progressively decreases in the direction of movement of the image-bearing surface of said image carrier, and wherein said flow of air is formed such that the air flows through regions between the inner surfaces of said housing of said image forming unit and the adjacent surfaces of said cleaning means towards said exposure opening.
Claim 22
Dependent Claim
45 words
An image forming apparatus according to any one of claims 14, 15, 16, 17 or 18, wherein said exposure opening formed in said housing of said image forming unit enables a latent image to be formed on said image carrier through a light exposure operation.
Claim 23
Dependent Claim
18 words
An image forming apparatus according to claim 14, wherein said image forming unit further comprises a developing means.
Claim 24
Dependent Claim
167 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, developing means for forming a developed image on said image carrier, said developing means being contained within a casing, cleaning means for cleaning said image carrier, and a housing supporting said image carrier, said charging means and said cleaning means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between inner side surfaces of said housing of said image forming unit, proximate to both longitudinal ends of said image carrier and side surfaces of said casing of said developing means towards said exposure opening along a passage formed between a top of said casing of said developing means and said housing.
Claim 25
Dependent Claim
167 words
An image forming apparatus comprising: a detachable image forming unit comprising an elongated, cylindrical image carrier having a photosensitive layer, charging means for electrostatically charging said image carrier in contact therewith, developing means for forming a developed image on said image carrier, said developing means being contained within a casing, cleaning means for cleaning said image carrier, and a housing supporting said image carrier, said charging means and said cleaning means, said housing being provided with an exposure opening through which said image carrier is exposed to a light; and means for generating a flow of air which flows, when said image forming unit is in a predetermined mounting position in said apparatus, from regions between inner side surfaces of said housing of said image forming unit, proximate to both longitudinal ends of said image carrier and side surfaces of said casing of said developing means towards said exposure opening along a passage formed between a top of said casing of said developing means and said housing.
Claim 26
Dependent Claim
22 words
An image forming apparatus according to claim 21, wherein said means for generating a flow of air comprises a suction ventilation fan.
Claim 27
Dependent Claim
36 words
An image forming apparatus according to claim 21, wherein said charging means comprises a rotary charging member in rolling contact with said image carrier, and means for applying a predetermined voltage to said rotary charging member.
Claim 28
Dependent Claim
35 words
An image forming apparatus according to claim 21, wherein said charging means comprises a blade type charging member contacting said image carrier, and means for applying a predetermined voltage to said blade type charging member.
Claim 29
Dependent Claim
44 words
An image forming apparatus according to any one of claims 21, 22, 23 and 24, wherein said exposure opening formed in said housing of said image forming unit enables a latent image to be formed on said image carrier through a light exposure operation.
Claim 30
Dependent Claim
63 words
An image forming apparatus according to claim 21, wherein said developing means and said cleaning means are disposed in said image forming unit such that, when said image forming unit has been mounted in a predetermined mounting position in said apparatus, said cleaning means and said developing means substantially vertically oppose each other across a path of light leading to said exposure opening.
Claim 31
Dependent Claim
41 words
An image forming apparatus according to any one of claims 1, 7, 14 or 21, wherein said exposure opening is formed in said housing of said image forming unit so as to extend in the longitudinal direction of said image carrier.
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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) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |