US4811046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tri-level highlight color printing apparatus with cycle-up and cycle-down control
Assignee: Xerox Corp
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Filing: 1987-07-28
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Granted: 1989-03-07
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Expires: 2007-07-28
Abstract
Abstract Undesirable transient development conditions that occur during start-up and shut-down in a tri-level xerographic system when the developer biases are either actuated or de-actuated are obviated by the provision of developer apparatuses having rolls which are adapted to be rotated in a predetermined direction for preventing developer contact with the imaging surface during periods of start-up and shut-down. The developer rolls of a selected developer housing or housings can be rotated in a the contact-preventing direction to permit use of the tri-level system to be utilized as a single color system or for the purpose of agitating developer in only one of the housings at time to insure internal triboelectric equilibrium of the developer in that housing.
Inventors
- 👤 Jerome E. May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/01; G03G15/0105; G03G15/0126
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
122 words
A method for producing plural-color images, said method including the steps of: uniformly charging a charge retentive member; actuating a light source capable of uniformly discharging said charge retentive member and selectively discharging said charge retentive member in accordance with information to be produced; using said light source, uniformly discharging said charge retentive member to a first predetermined voltage level; decreasing the intensity of said light source thereby allowing the charge level on said charge retentive member to increase above said predetermined level; controlling developer structure such that contact between the developer material and said charge retentive member is prevented until a second predetermined voltage level, substantially greater than said first predetermined voltage level, on said charge retentive member has been reached.
Claim 2
Independent Claim
122 words
A method for producing plural-color images, said method including the steps of: uniformly charging a charge retentive member; actuating a light source capable of uniformly discharging said charge retentive member and selectively discharging said charge retentive member in accordance with information to be produced; using said light source, uniformly discharging said charge retentive member to a first predetermined voltage level; decreasing the intensity of said light source thereby allowing the charge level on said charge retentive member to increase above said predetermined level; controlling developer structure such that contact between the developer material and said charge retentive member is prevented until a second predetermined voltage level, substantially greater than said first predetermined voltage level, on said charge retentive member has been reached.
Claim 3
Dependent Claim
24 words
The method according to claim 1 wherein said step of controlling a developer structure comprises rotating a magnetic roll structure in a first direction.
Claim 4
Dependent Claim
45 words
The method according to claim 2 including the step of rotating said magnetic roll structure in the opposite direction after said charge retentive member has reached said second predetermined level whereby developer material is brought into contact with latent images on said charge retentive member.
Claim 5
Dependent Claim
25 words
The method according to claim 2 wherein said step of controlling developer structure comprises rotating a pair of magnetic roll structures in a first direction.
Claim 6
Dependent Claim
47 words
The method according to claim 4 including the step of rotating said pair of magnetic roll structures in the opposite direction after said charge retentive member has reached said second predetermined level whereby developer material is brought into contact with latent images on said charge retentive member.
Claim 7
Dependent Claim
58 words
The method according to claim 1 further including the steps of: terminating the formation of latent images; decreasing the intensity of said light source to said first predetermined voltage level; controlling said developer structure such that contact between the developer material and said charge retentive member is prevented during the decreasing of the intensity of said light source.
Claim 8
Dependent Claim
19 words
The method according to claim 1 wherein said step of controlling a developer structure comprises controlling two developer housings.
Claim 9
Dependent Claim
28 words
The method according to claim 7 wherein said step of controlling developer structure comprises rotating a magnetic roll structure in each of said housings in a first direction.
Claim 10
Dependent Claim
47 words
The method according to claim 8 including the step of rotating each of said magnetic roll structures in the opposite direction after said charge retentive member has reached said second predetermined level whereby developer material is brought into contact with latent images on said charge retentive member.
Claim 11
Dependent Claim
30 words
The method according to claim 9 wherein said step of controlling developer structure comprises rotating a pair of magnetic roll structures in each of said housings in a first direction.
Claim 12
Dependent Claim
48 words
The method according to claim 10 including the step of rotating each pair of said magnetic roll structures in the opposite direction after said charge retentive member has reached said second predetermined level whereby developer material is brought into contact with latent images on said charge retentive member.
Claim 13
Dependent Claim
58 words
The method according to claim 11 further including the steps of: terminating the formation of latent images; decreasing the intensity of said light source to said first predetermined voltage level; controlling said developer structure such that contact between the developer material and said charge retentive member is prevented during the decreasing of the intensity of said light source.
Claim 14
Dependent Claim
109 words
Apparatus for forming images on a charge retentive surface, said apparatus comprising: a supply of developer; at least one pair of magnetic roll structures including an outer shell supported for rotation and spaced a predetermined distance apart; means for effecting rotation of said rolls in first and second directions; said magnetic roll structures being of a predetermined diameter and having a magnetic field profile and spacing between said at least one pair of magnetic roll structures whereby rotation thereof in one of said directions effects efficient application of developer to said charge retentive surface and rotation in the opposite direction prevents developer material from contacting said charge retentive surface.
Claim 15
Dependent Claim
109 words
Apparatus for forming images on a charge retentive surface, said apparatus comprising: a supply of developer; at least one pair of magnetic roll structures including an outer shell supported for rotation and spaced a predetermined distance apart; means for effecting rotation of said rolls in first and second directions; said magnetic roll structures being of a predetermined diameter and having a magnetic field profile and spacing between said at least one pair of magnetic roll structures whereby rotation thereof in one of said directions effects efficient application of developer to said charge retentive surface and rotation in the opposite direction prevents developer material from contacting said charge retentive surface.
Claim 16
Dependent Claim
69 words
Apparatus according to claim 13 including a second pair of magnetic roll structures identical in construction to said at least one pair of magnetic rolls and adapted to apply developer of a different color from that applied by said at least one pair of magnetic rolls and wherein said means for effecting rotation also effects rotation of said second pair of magnetic roll structures in first and second directions.
Claim 17
Dependent Claim
36 words
Apparatus according to claim 14 wherein said rotation effecting means is adapted to rotate said at least one pair of magnetic rolls and said second pair of magnetic rolls in opposite directions at the same time.
Claim 18
Dependent Claim
103 words
Apparatus according to claim 13 including: means for uniformly charging a charge retentive member; means for actuating a light source for uniformly discharging said charge retentive member and selectively discharging said charge retentive member in accordance with information to be produced; means for causing said light source to uniformly discharge said charge retentive member to a first predetermined voltage level; means for decreasing the intensity of said light source thereby allowing the charge level on said charge retentive member to increase above said predetermined level; wherein said magnetic roll structures are rotated in said opposite direction until said predetermined charge level is attained.
Claim 19
Dependent Claim
67 words
Apparatus according to claim 16 further including: means for terminating the formation of latent images; means of decreasing the intensity of said light source to said first predetermined voltage level; means of rotating said pair of magnetic roll structures in said opposite direction so that contact between the developer material and said charge retentive member is prevented during the decreasing of the intensity of said light source.
Claim 20
Dependent Claim
56 words
Apparatus according to claim 16 including a second pair of magnetic roll structures identical in construction to said at least one pair of magnetic roll structures, said second pair of magnetic roll structures being provided for applying a different color developer to said charge retentive surface from said at least one pair of magnetic roll structures.
Claim 21
Dependent Claim
20 words
Apparatus according to claim 18 wherein rotation of one pair is terminated while rotation of the other pair is continued.
Claim 22
Dependent Claim
125 words
Apparatus for forming images on a charge retentive surface, said apparatus comprising: a supply of developer; at least one pair of magnetic roll structures including an outer shell supported for rotation and spaced a predetermined distance apart; means for effecting rotation of said rolls in first and second directions; said magnetic roll structures having magnetic field force profiles whereby rotation thereof in one of said directions effects movement of developer from one of said magnetic roll structures to the other and application of developer to said charge retentive surface, and rotation in the opposite direction prevents developer material from contacting said charge retentive surface and prevents movement of developer from said one of said magnetic roll structures to said other of said magnetic roll structures.
Claim 23
Dependent Claim
125 words
Apparatus for forming images on a charge retentive surface, said apparatus comprising: a supply of developer; at least one pair of magnetic roll structures including an outer shell supported for rotation and spaced a predetermined distance apart; means for effecting rotation of said rolls in first and second directions; said magnetic roll structures having magnetic field force profiles whereby rotation thereof in one of said directions effects movement of developer from one of said magnetic roll structures to the other and application of developer to said charge retentive surface, and rotation in the opposite direction prevents developer material from contacting said charge retentive surface and prevents movement of developer from said one of said magnetic roll structures to said other of said magnetic roll structures.
Claim 24
Dependent Claim
62 words
Apparatus according to claim 20 including a second pair of magnetic roll structures identical in construction to said at least one pair of magnetic rolls and adapted to apply developer of a different color from that applied by said at least one pair of magnetic rolls and wherein said means for effecting rotation also effects rotation thereof in first and second directions.
Claim 25
Dependent Claim
36 words
Apparatus according to claim 21 wherein said rotation effecting means is adapted to rotate said at least one pair of magnetic rolls and said second pair of magnetic rolls in opposite directions at the same time.
Claim 26
Dependent Claim
103 words
Apparatus according to claim 22 including: means for uniformly charging a charge retentive member; means for actuating a light source for uniformly discharging said charge retentive member and selectively discharging said charge retentive member in accordance with information to be produced; means for causing said light source to uniformly discharge said charge retentive member to a first predetermined voltage level; means for decreasing the intensity of said light source thereby allowing the charge level on said charge retentive member to increase above said predetermined level; wherein said magnetic roll structures are rotated in said opposite direction until said predetermined charge level is attained.
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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) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |