US5034777A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transferring device having charging device with double oxide and voltage control
Assignee: Canon Inc
•
Filing: 1990-06-14
•
Granted: 1991-07-23
•
Expires: 2010-06-14
Abstract
Abstract An image forming apparatus includes a movable image bearing member; an image forming device for forming an image on the image bearing member; a transfer device for transferring an image from the image bearing member to a transfer material at a transfer position, wherein the transfer device is contactable to a backside of the transfer material at the transfer position and includes a charging member including a double oxide and a voltage source for applying a voltage to the charging member, and wherein the voltage source constant-voltage-controls the charging member when an image region of the image bearing member is at the transfer position, and constant-current-controls the charging member in at least a part of a period when the image region of the image bearing member is not at the transfer position, wherein a constant voltage for the constant voltage control is determined on the basis of the constant current control.
Inventors
- 👤 Yukihiro Ohzeki
- 👤 Koichi Hiroshima
- 👤 Yoshiaki Nishimura
- 👤 Jun Murata
- 👤 Junji Araya
- 👤 Tatsunori Ishiyama
- 👤 Yasushi Sato
- 👤 Kimio Nakahata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:51
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/14; G03G15/16; G03G15/1665; G03G15/167; G03G15/1675
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
148 words
An image forming apparatus, comprising: a movable image bearing member; image forming means for forming an image on said image bearing member; transfer means for transferring an image from said image bearing member to a transfer material at a transfer position, wherein said transfer means is contactable to a backside of the transfer material at the transfer position and includes a charging member comprising a double oxide and means for applying a voltage to the charging member, and wherein said voltage applying means constant-voltage-controls the charging member when an image region of said image bearing member is at the transfer position, and constant-current-controls the charging member in at least a part of a period when the image region of said image bearing member is not at the transfer position, wherein a constant voltage for the constant voltage control is determined on the basis of the constant current control.
Claim 2
Dependent Claim
148 words
An image forming apparatus, comprising: a movable image bearing member; image forming means for forming an image on said image bearing member; transfer means for transferring an image from said image bearing member to a transfer material at a transfer position, wherein said transfer means is contactable to a backside of the transfer material at the transfer position and includes a charging member comprising a double oxide and means for applying a voltage to the charging member, and wherein said voltage applying means constant-voltage-controls the charging member when an image region of said image bearing member is at the transfer position, and constant-current-controls the charging member in at least a part of a period when the image region of said image bearing member is not at the transfer position, wherein a constant voltage for the constant voltage control is determined on the basis of the constant current control.
Claim 3
Dependent Claim
17 words
An apparatus according to claim 1, wherein the charging member is contactable to said image bearing member.
Claim 4
Dependent Claim
14 words
An apparatus according to claim 2, wherein the charging member includes an elastic member.
Claim 5
Dependent Claim
23 words
An apparatus according to claim 1 or 3, wherein the double oxide is a solid solution compound comprising zinc oxide and aluminum oxide.
Claim 6
Dependent Claim
22 words
An apparatus according to claim 1 or 3, wherein the charging member has a volume resistivity of 10 6 -10 13 ohm.cm
Claim 7
Dependent Claim
26 words
An apparatus according to claim 1 or 3, wherein the charging member contains 0.1-20% by weight of carbon black and 5-20% by weight of insulating oil.
Claim 8
Dependent Claim
18 words
An apparatus according to claim 3, wherein the elastic member contains 5-40% by weight of the double oxide.
Claim 9
Dependent Claim
30 words
An apparatus according to claim 1, wherein the image region of said image bearing member is a region in which a toner image is formed on said image bearing member.
Claim 10
Dependent Claim
16 words
An apparatus according to claim 8, wherein the image region is contactable with the transfer material.
Claim 11
Dependent Claim
29 words
An apparatus according to claim 1, wherein said at least the part of the period includes a period in which the image region is upstream of the transfer position.
Claim 12
Dependent Claim
15 words
An apparatus according to claim 1, 2 or 3, wherein the charging member is rotatable.
Claim 13
Dependent Claim
17 words
An apparatus according to claim 11, wherein the charging member is in the form of a roller.
Claim 14
Dependent Claim
29 words
An apparatus according to claim 1, wherein the constant voltage is determined on the basis of a voltage of said transfer means when the constant current control is effected
Claim 15
Dependent Claim
23 words
An apparatus according to claim 1, wherein the constant current control is effected when the transfer material is absent at the transfer position.
Claim 16
Dependent Claim
23 words
An apparatus according to claim 1, wherein said image forming means includes means for forming a latent image on said image bearing member.
Claim 17
Dependent Claim
30 words
An apparatus according to claim 15, wherein a voltage applied to the charging member in the constant voltage control has a polarity opposite to a polarity of the latent image.
Claim 18
Dependent Claim
17 words
An apparatus according to claim 1 or 16, wherein said image bearing member is a photosensitive member.
Claim 19
Dependent Claim
17 words
An apparatus according to claim 1 or 16, wherein said image bearing member is an organic photoconductor.
Claim 20
Dependent Claim
157 words
An image forming apparatus, comprising: a movable image bearing member; image forming means for forming an image on said image bearing member; transfer means for transferring the image from said image bearing member onto a transfer material, wherein said transfer means is contactable to a backside of the transfer material at the transfer position and includes a charging member comprising a double oxide and voltage applying means for applying a voltage to the charging member, and wherein the voltage applying means constant-voltage-controls the charging member with a first voltage when an image region of said image bearing member is at the transfer position, and constant-voltage-controls the charging member with a second voltage in at least a part of a period when the image region is not at the transfer position, wherein the first voltage is determined on the basis of a current flowing through said transfer means when the charging member is constant-voltage-controlled with the second voltage.
Claim 21
Dependent Claim
157 words
An image forming apparatus, comprising: a movable image bearing member; image forming means for forming an image on said image bearing member; transfer means for transferring the image from said image bearing member onto a transfer material, wherein said transfer means is contactable to a backside of the transfer material at the transfer position and includes a charging member comprising a double oxide and voltage applying means for applying a voltage to the charging member, and wherein the voltage applying means constant-voltage-controls the charging member with a first voltage when an image region of said image bearing member is at the transfer position, and constant-voltage-controls the charging member with a second voltage in at least a part of a period when the image region is not at the transfer position, wherein the first voltage is determined on the basis of a current flowing through said transfer means when the charging member is constant-voltage-controlled with the second voltage.
Claim 22
Dependent Claim
17 words
An apparatus according to claim 19, wherein the charging member is contactable to said image bearing member.
Claim 23
Dependent Claim
14 words
An apparatus according to claim 20, wherein the charging member includes an elastic member.
Claim 24
Dependent Claim
23 words
An apparatus according to claim 19 or 21, wherein the double oxide is a solid solution compound comprising zinc oxide and aluminum oxide.
Claim 25
Dependent Claim
22 words
An apparatus according to claim 19 or 21, wherein the charging member has a volume resistivity of 10 6 -10 13 ohm.cm.
Claim 26
Dependent Claim
26 words
An apparatus according to claim 19 or 21, wherein the charging member contains 0.1-20% by weight of carbon black and 5-20% by weight of insulating oil.
Claim 27
Dependent Claim
18 words
An apparatus according to claim 21, wherein the elastic member contains 5-40% by weight of the double oxide.
Claim 28
Dependent Claim
30 words
An apparatus according to claim 19, wherein the image region of said image bearing member is a region in which a toner image is formed on said image bearing member.
Claim 29
Dependent Claim
16 words
An apparatus according to claim 26, wherein the image region is contactable with the transfer material.
Claim 30
Dependent Claim
29 words
An apparatus according to claim 19, wherein said at least the part of the period includes a period in which the image region is upstream of the transfer position.
Claim 31
Dependent Claim
15 words
An apparatus according to claim 19, 20 or 21, wherein the charging member is rotatable.
Claim 32
Dependent Claim
17 words
An apparatus according to claim 29, wherein the charging member is in the form of a roller.
Claim 33
Dependent Claim
27 words
An apparatus according to claim 19, wherein the constant voltage control with the second voltage is effected when the transfer material is not at the transfer position.
Claim 34
Dependent Claim
23 words
An apparatus according to claim 19, wherein said image forming means includes means for forming a latent image on said image bearing member.
Claim 35
Dependent Claim
32 words
An apparatus according to claim 32, wherein the voltage applied to the charging member when it is constant-voltage-controlled with the first voltage has a polarity opposite to that of the latent image.
Claim 36
Dependent Claim
17 words
An apparatus according to claim 19 or 33, wherein said image bearing member is a photosensitive member.
Claim 37
Dependent Claim
17 words
An apparatus according to claim 19 or 33, wherein said image bearing member is an organic photoconductor.
References Cited (Backward Citations)
US3937572A
Cited
US3781105A
Cited
US3924943A
Cited
US3954333A
Cited
US4190348A
Cited
US4379630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |