US3699335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for charging a recording element with an electrostatic charge of a desired amplitude
Assignee: RCA Corp
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Filing: 1971-01-06
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Granted: 1972-10-17
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Expires: 1991-01-06
Abstract
Abstract Apparatus for charging a recording element includes a corona generating device that is energized with pulses of a constant amplitude. Circuitry is provided for obtaining an error signal, if the total charge applied to the recording element tends to vary from a preset desired amplitude, and for controlling the width or the frequency of the pulses in response to the error signal to regulate the applied charge. The method of charging the surface of the recording element to a desired amplitude in a given time includes applying an electrostatic charge to the recording element in pulses and adjusting either the width or the frequency of the pulses to obtain the desired amplitude.
Inventors
- 👤 Edward Charles Giaimo Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:13
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0266
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
In an electrostatic printing system of the type wherein a corona generating device is disposed to apply an electrostatic charge to a surface, the improvement of means to regulate the electrostatic charge resulting on said surface at a desired amplitude comprising: electrical energizing means to energize said corona generating device with voltage pulses of a constant amplitude, whereby to apply an electrostatic charge to said surface, means to obtain an error signal when the amplitude of the electrostatic charge on said surface varies from said desired amplitude, and feed-back means, responsive to said error signal, to control the width or the frequency of said voltage pulses of a constant amplitude, whereby to regulate the electrostatic charge on said surface.
Claim 2
Dependent Claim
119 words
In an electrostatic printing system of the type wherein a corona generating device is disposed to apply an electrostatic charge to a surface, the improvement of means to regulate the electrostatic charge resulting on said surface at a desired amplitude comprising: electrical energizing means to energize said corona generating device with voltage pulses of a constant amplitude, whereby to apply an electrostatic charge to said surface, means to obtain an error signal when the amplitude of the electrostatic charge on said surface varies from said desired amplitude, and feed-back means, responsive to said error signal, to control the width or the frequency of said voltage pulses of a constant amplitude, whereby to regulate the electrostatic charge on said surface.
Claim 3
Dependent Claim
44 words
An electrostatic printing system of the type described in claim 1, wherein said corona generating device comprises at least one corona discharge wire disposed for relative motion with respect to, and adjacent, said surface, and said surface is a surface of a recording element.
Claim 4
Dependent Claim
95 words
An electrostatic printing system of the type described in claim 2, wherein the speed of said relative motion between said corona generating device and said surface is substantially constant, said energizing means includes a power supply adapted to provide an output voltage that is substantially constant and at least sufficient to produce a corona discharge from said corona discharge wire, and said energizing means comprises switching means to connect and disconnect said power supply to said corona discharge wire in response to said error signal, whereby to provide said voltage pulses of a constant amplitude.
Claim 5
Dependent Claim
64 words
An electrostatic printing system of the type described in claim 3, wherein said means to obtain an error signal comprises an adjustable reference voltage means, whereby to select or preset said desired amplitude of said electrostatic charge, probe means to sample the voltage applied to said surface, and means to compare said reference voltage with the sampled voltage, whereby to obtain said error signal.
Claim 6
Dependent Claim
64 words
An electrostatic printing system of the type described in claim 4, wherein said feed-back means comprises a free-running multivibrator circuit having means to vary its frequency in response to said error signal, and means to apply the output of said multivibrator circuit to said switching means to control the frequency at which said power supply is connected and disconnected to said corona discharge wire.
Claim 7
Dependent Claim
90 words
An electrostaTic printing system of the type described in claim 4, wherein said feed-back means comprises a free-running multivibrator circuit having means to set its frequency of output at a constant frequency, a monostable flip-flop circuit having an input, responsive to the output of said multivibrator circuit, and having an output connected to said switching means, and means to apply said error signal to said flip-flop circuit to vary the pulse width of the output of said flip-flop circuit, whereby to control the rate of switching of said switching means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |