Patent US3837741A successfully refreshed from Google Patents.
US3837741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control arrangement for transfer roll power supply
Assignee: Xerox Corp
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Filing: 1973-12-28
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Granted: 1974-09-24
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Expires: 1993-12-28
Abstract
Abstract An arrangement for controlling the electrical bias applied to a bias transfer roller comprising a voltage source coupled to the transfer roller which is variable in response to a control signal, the control signal being generated by sensing the voltage across a sample of the roller material connected in series with a constant current source. Since the resistivity of the sample material varies with changes in humidity, the voltage and the control signal likewise vary with humidity to change the voltage applied to the transfer roller.
Inventors
- 👤 P Spencer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:57
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/1665; G03G15/167; G03G15/1675
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
91 words
An arrangement for changing the voltage applied to a bias transfer roll in a xerographic copy mechanism comprising: a housing in which said mechanism is located, a source of voltage, said source coupled to said roll and variable in response to a control signal, and a piece of material similar in construction to said bias roll, located apart from said roll but within said housing, means for generating a constant current through said material, and means responsive to the voltage across said material for controlling the magnitude of said voltage source.
Claim 2
Dependent Claim
91 words
An arrangement for changing the voltage applied to a bias transfer roll in a xerographic copy mechanism comprising: a housing in which said mechanism is located, a source of voltage, said source coupled to said roll and variable in response to a control signal, and a piece of material similar in construction to said bias roll, located apart from said roll but within said housing, means for generating a constant current through said material, and means responsive to the voltage across said material for controlling the magnitude of said voltage source.
Claim 3
Dependent Claim
95 words
An arrangement for compensating for changes in resistivity on a bias transfer roll due to changing humidity conditions comprising, a xerographic copy machine including a bias transfer roll mounted for rOtation on a shaft, a second smaller roll of similar construction mounted on an extension of said shaft and insulated therefrom, means for connecting a constant current source in series with said second roll, a voltage source coupled to said transfer roll and means responsive to changes in voltage across said second roll for altering the voltage applied by said source to said transfer roll.
Claim 4
Dependent Claim
95 words
An arrangement for compensating for changes in resistivity on a bias transfer roll due to changing humidity conditions comprising, a xerographic copy machine including a bias transfer roll mounted for rOtation on a shaft, a second smaller roll of similar construction mounted on an extension of said shaft and insulated therefrom, means for connecting a constant current source in series with said second roll, a voltage source coupled to said transfer roll and means responsive to changes in voltage across said second roll for altering the voltage applied by said source to said transfer roll.
Claim 5
Dependent Claim
28 words
The combination recited in claim 2 wherein said means for connecting includes an auxiliary conductive roller mounted for rotation in contact with the periphery of said second roll.
Claim 6
Dependent Claim
98 words
A humidity compensated apparatus for transferring charged particles from a support surface to a sheet of support material, comprising: a transfer member, said transfer member cooperating electrically with the support surface to attract the charged particles therefrom to the sheet of support material; bias means for electrically biasing said transfer member to a potential of sufficient magnitude to attract the charged particles from the support surface to the sheet of support material, means for adjusting the magnitude of the biasing potential applied to said transfer member to correct automatically for changes in the resistivity of said transfer member.
Claim 7
Dependent Claim
98 words
A humidity compensated apparatus for transferring charged particles from a support surface to a sheet of support material, comprising: a transfer member, said transfer member cooperating electrically with the support surface to attract the charged particles therefrom to the sheet of support material; bias means for electrically biasing said transfer member to a potential of sufficient magnitude to attract the charged particles from the support surface to the sheet of support material, means for adjusting the magnitude of the biasing potential applied to said transfer member to correct automatically for changes in the resistivity of said transfer member.
Claim 8
Dependent Claim
52 words
The combination recited in claim 4 wherein said means for adjusting includes a constant current source connected in series with said transfer member, and means responsive to changes in the voltage across said transfer member to vary the magnitude of the biasing potential applied by said bias means to said transfer member.
Claim 9
Dependent Claim
19 words
The combination recited in claim 4 wherein said means for adjusting is operative intermittently to vary said applied potential.
Claim 10
Dependent Claim
77 words
The combination recited in claim 4 wherein said means for adjusting comprises a piece of material similar in construction to said transfer member located remote therefrom, means for generating a constant current through said piece, and means responsive to the voltage across said piece to vary the magnitude of the bias potential applied to said transfer member, whereby changes in humidity result in voltage variations across said piece, said voltage variations operating to control said bias means.
Claim 11
Dependent Claim
79 words
The combination recited in claim 4 wherein said means for adjusting comprises contact means intermittently movable into contact with the surface of said transfer means for a preselected time, means actuated concurrently with the movement of said contact means for generating a constant current through said transfer member, current means for determining the average value of the voltage across said transfer member over said preselected time, and means for adjusting said bias means in accordance with the average voltage.
References Cited (Backward Citations)
US2847305A
Cited
US3424131A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |