US4771314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developer apparatus for a highlight printing apparatus
Assignee: Xerox Corp
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Filing: 1986-12-29
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Granted: 1988-09-13
•
Expires: 2006-12-29
Abstract
Abstract Printing apparatus for forming toner images in black and at least one highlighting color in a single pass of a change retentive imaging surface through the processing areas, including a development station, of the printing apparatus. The development station includes a pair of developer housings each of which has supported therein a pair of magnetic brush development rolls which are electrically biased to provide electrostatic development and cleaning fields between the charge retentive surface and the developer rolls. The rolls are biased such that the development fields between the first rolls in each housing and the charge retentive surface are greater than those between the charge retentive surface and the second rolls and such that the cleaning fields between the second rolls in each housing and the charge retentive surface are greater than those between the charge retentive surface and the first rolls.
Inventors
- 👤 Delmer G. Parker
- 👤 William M. Allen, Jr.
- 👤 Richard P. Germain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:12
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/0121; G03G15/06; G03G15/08; G03G15/09
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
117 words
Printing apparatus for forming images on a charge retentive surface, said apparatus comprising: means for forming at least a tri-level latent electrostatic image on said charge retentive surface, said latent electrostatic image comprising image areas at different charge levels; means for applying toner to one of said image areas to thereby render said one of said image areas visible; means for applying a first electrical bias to said toner applying means to thereby establish development and cleaning fields between it and said charge retentive surface; means for applying a second electrical bias to said toner applying means to thereby establish development and cleaning fields between it and said charge retentive surface, said electrical biases comprising different magnitudes.
Claim 2
Dependent Claim
117 words
Printing apparatus for forming images on a charge retentive surface, said apparatus comprising: means for forming at least a tri-level latent electrostatic image on said charge retentive surface, said latent electrostatic image comprising image areas at different charge levels; means for applying toner to one of said image areas to thereby render said one of said image areas visible; means for applying a first electrical bias to said toner applying means to thereby establish development and cleaning fields between it and said charge retentive surface; means for applying a second electrical bias to said toner applying means to thereby establish development and cleaning fields between it and said charge retentive surface, said electrical biases comprising different magnitudes.
Claim 3
Dependent Claim
64 words
Apparatus according to claim 1 wherein said first electrical bias is less than said second electrical bias whereby a greater development field is established between said charge retentive surface and said toner applying means when said first electrical bias is applied and a greater cleaning field is established between said charge retentive surface and toner applying means when said second electrical bias is applied.
Claim 4
Dependent Claim
24 words
Apparatus according to claim 2 wherein said one of said image areas is first exposed to the field created by said first electrical bias.
Claim 5
Dependent Claim
19 words
Apparatus according to claim 3 wherein said toner applying means comprises a first developer housing containing toner applying structure.
Claim 6
Dependent Claim
23 words
Apparatus according to claim 4 including a second developer housing containing toner applying structure for rendering the other of said image areas visible.
Claim 7
Dependent Claim
19 words
Apparatus according to claim 5 wherein each of said toner applying structures comprises a pair of magnetic brush members.
Claim 8
Dependent Claim
23 words
Apparatus according to claim 6 wherein said magnetic brush members comprise at least two magnetic brush rolls in each of said developer housings.
Claim 9
Dependent Claim
43 words
Apparatus according to claim 7 wherein said first electrical bias is applied to one of the magnetic brush rolls in said first developer housing and said second electrical bias is applied to the other of the brush rolls in said first developer housing.
Claim 10
Dependent Claim
24 words
Apparatus according to claim 8 including means for applying electrical third and fourth biases to the magnetic brush rolls in said second developer housing.
Claim 11
Dependent Claim
24 words
Apparatus according to claim 9 wherein said toner image is formed in a single pass of said charge retentive surface past said developer housings.
Claim 12
Dependent Claim
27 words
Apparatus according to claim 10 wherein said tri-level latent electrostatic image comprises image areas at approximately 100 and 700 volts and background areas at approximately 400 volts.
Claim 13
Dependent Claim
22 words
Apparatus according to claim 11 wherein said first, second, third and fourth electrical biases are 450, 500, 350 and 300 volts, respectively.
Claim 14
Dependent Claim
25 words
Apparatus according to claim 1 wherein there the difference between said first and second bias voltages is in the range of 50 to 60 volts.
Claim 15
Dependent Claim
64 words
Apparatus according to claim 13 wherein said first electrical bias is less than said second electrical bias whereby a greater development field is established between said charge retentive surface and said toner applying means when said first electrical bias is applied and a greater cleaning field is established between said charge retentive surface and toner applying means when said second electrical bias is applied.
Claim 16
Dependent Claim
20 words
Apparatus according to claim 14 wherein said latent image is first exposed to the fields created by said first bias.
Claim 17
Dependent Claim
14 words
Apparatus according to claim 15 including a second developer housing containing toner applying structure.
Claim 18
Dependent Claim
19 words
Apparatus according to claim 16 wherein each of said toner applying structures comprises a pair of magnetic brush members.
Claim 19
Dependent Claim
23 words
Apparatus according to claim 17 wherein said magnetic brush members comprise at least two magnetic brush rolls in each of said developer housings.
Claim 20
Dependent Claim
43 words
Apparatus according to claim 18 wherein said first electrical bias is applied to only one of the brush rolls in said first developer housing and said second electrical bias is applied to the other of the brush rolls in said first developer housing.
Claim 21
Dependent Claim
24 words
Apparatus according to claim 19 wherein said toner image is formed in a single pass of said charge retentive surface past said developer housings.
Claim 22
Dependent Claim
27 words
Apparatus according to claim 20 wherein said tri-level latent electrostatic image comprises image areas at approximately 100 and 700 volts and background areas at approximately 400 volts.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |