Patent US4839671A successfully refreshed from Google Patents.
US4839671A
Expired / Lapsed
US
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Selectable density charge deposition printing system
Assignee: Delphax Systems Inc
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Filing: 1988-10-04
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Granted: 1989-06-13
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Expires: 2008-10-04
Abstract
Abstract Ionographic raster scan printing apparatus capable of printing with selectable print density utilizes an imaging drum having a surface movable in a process direction, a connector assembly for receiving an imaging module having a characteristic dot density determined by a set of control electrodes individually driven by clocked driver elements, a sensor module for generating density signals representative of the characteristic dot density, and a position encoder for generating position signals representative of the instantaneous position of the imaging drum surface. A scan clock synthesizer module generates activation signals for clocking the driver elements, the signals having a clock frequency proportional to an algebraic combination of the density signals and the position signals.
Inventors
- 👤 Sotos M. Theodoulou
- 👤 Christopher W. Thomson
- 👤 Eric Vannerson
- 👤 Wm. Keith Baker
- 👤 Alvin C. P. Sun
- 👤 Ken Hurley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:52
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/39; B41J2/40; H; H04; H04N; H04N1/00; H04N1/40; H04N1/40025; H04N1/40031; Y; Y10; Y10S; Y10S347/00; Y10S347/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
215 words
In an ionographic raster scan printing apparatus including an imaging drum having a surface movable in a predetermined process direction, and a connector assembly for receiving a replaceable imaging module having a characteristic dot density corresponding to a set of control electrodes individually driven by clocked driver elements, a system for printing with selectable print density, the system comprising A. sensor means, in association with the imaging assembly, for sensing the characteristic dot density of the imaging module and for generating density signals representative of the characteristic dot density, B. position encoder means, in association with the imaging drum, for generating position signals representative of the instantaneous position of the imaging drum surface, C. scan clock synthesizer means, responsive to said density signals and said position signals, for synthesizing clocked activation signals for clocking the driver elements, said clocked activation signals having a clock frequency proportional to an algebraic combination of said density signals and said position signals, and D. raster image processor/controller means, responsive to said density signals, for configuring raster image data to the dot density represented by the density signals, E. whereby print density in the process direction is selectable by said clock frequency, and print density in a direction transverse to the process direction is selectable by the characteristic dot density.
Claim 2
Dependent Claim
215 words
In an ionographic raster scan printing apparatus including an imaging drum having a surface movable in a predetermined process direction, and a connector assembly for receiving a replaceable imaging module having a characteristic dot density corresponding to a set of control electrodes individually driven by clocked driver elements, a system for printing with selectable print density, the system comprising A. sensor means, in association with the imaging assembly, for sensing the characteristic dot density of the imaging module and for generating density signals representative of the characteristic dot density, B. position encoder means, in association with the imaging drum, for generating position signals representative of the instantaneous position of the imaging drum surface, C. scan clock synthesizer means, responsive to said density signals and said position signals, for synthesizing clocked activation signals for clocking the driver elements, said clocked activation signals having a clock frequency proportional to an algebraic combination of said density signals and said position signals, and D. raster image processor/controller means, responsive to said density signals, for configuring raster image data to the dot density represented by the density signals, E. whereby print density in the process direction is selectable by said clock frequency, and print density in a direction transverse to the process direction is selectable by the characteristic dot density.
Claim 3
Dependent Claim
28 words
A system according to claim 1, wherein said raster image processor/controller means includes means for controlling velocity of motion, in the process direction, of the imaging drum surface.
Claim 4
Dependent Claim
32 words
A system according to claim 1, wherein said scan clock synthesizer means includes phase-locked loop means for synthesizing said clocked activation signals in response to a detected frequency of said position signals
Claim 5
Dependent Claim
159 words
A system according to claim 3, wherein said phase-locked loop means includes A. voltage-controlled oscillator means for generating a first signal having a first frequency, B. frequency divider means, in circuit with said voltage-controlled oscillator means, for receiving said first signal having said first frequency and dividing said first frequency by at least a first selected integer quantity to produce at least a second signal having a second frequency, C. phase comparator means, in circuit with said frequency divider means and said position encoder means, for receiving said at least second signal and said position signals, and generating a phase comparator output signal proportional to phase differences between said at least second signal and said position signals, and D. loop filter means, in circuit with said phase comparator means and said voltage-controlled oscillator means, for attenuating high-frequency components of said phase comparator output signal and passing low-frequency components of said phase comparator output signal to said voltage-controlled oscillator means.
Claim 6
Dependent Claim
165 words
In an ionographic raster scan printing process including the steps of moving an imaging drum surface in a predetermined process direction, and receiving a replaceable imaging module having a characteristic dot density corresponding to a set of control electrodes individually driven by clocked driver elements, the improvement comprising the steps of A. sensing the characteristic dot density of the imaging module, B. generating density signals representative of the characteristic dot density, C. generating position signals representative of the instantaneous position of the imaging drum surface, D. synthesizing clocked activation signals, having a clock frequency proportional to an algebraic combination of said density signals and said position signals, for clocking the driver elements, and E. responding to said density signals to configure raster image data to the dot density represented by the density signals, F. whereby print density in the process direction is selectable by said clock frequency, and print density in a direction transverse to the process direction is selectable by the characteristic dot density.
Claim 7
Dependent Claim
165 words
In an ionographic raster scan printing process including the steps of moving an imaging drum surface in a predetermined process direction, and receiving a replaceable imaging module having a characteristic dot density corresponding to a set of control electrodes individually driven by clocked driver elements, the improvement comprising the steps of A. sensing the characteristic dot density of the imaging module, B. generating density signals representative of the characteristic dot density, C. generating position signals representative of the instantaneous position of the imaging drum surface, D. synthesizing clocked activation signals, having a clock frequency proportional to an algebraic combination of said density signals and said position signals, for clocking the driver elements, and E. responding to said density signals to configure raster image data to the dot density represented by the density signals, F. whereby print density in the process direction is selectable by said clock frequency, and print density in a direction transverse to the process direction is selectable by the characteristic dot density.
Claim 8
Dependent Claim
27 words
In a process according to claim 5, the further improvement comprising the step of controlling velocity of motion, in the process direction, of the imaging drum surface.
Claim 9
Dependent Claim
38 words
In a process according to claim 5, the further improvement wherein the synthesizing step includes the step of configuring a phase-locked loop for synthesizing said clocked activation signals in response to a detected frequency of said position signals.
Claim 10
Dependent Claim
102 words
In a process according to claim 7, the further improvement wherein the step of configuring a phase-locked loop includes the steps of A. generating a first signal having a first frequency, B. dividing said first frequency by at least a first selected integer quantity to produce at least a second signal having a second frequency, C. generating a phase comparator output signal proportional to phase differences between said at least second signal and said position signals, and D. attenuating high-frequency components of said phase comparator output signal and passing low-frequency components of said phase comparator output signal to said voltage-controlled oscillator means.
References Cited (Backward Citations)
US4786923A
Cited
US4763241A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |