US4028711A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and device for electrostatic printing
Assignee: US Philips Corp
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Filing: 1975-04-02
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Granted: 1977-06-07
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Expires: 1995-04-02
Abstract
Abstract An electrostatic printer having electrodes which each are constructed as a needle arranged on a rotatable drum mounted for translatory movements. At the recording area the needle slides directly over the paper under pressure to cause the paper to be slightly pushed away. The width of the recorded track is identified by the contact surface area of the needle.
Inventors
- 👤 Gerhard Jost
- 👤 Ulf Rothgordt
- 👤 Klaus Witter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:47
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/39; B41J2/395; G; G03; G03G; G03G15/00; G03G15/22; G03G15/32; G03G15/321; G03G15/325; G06; G06K; G06K15/00; G06K15/02; G06K15/14; G03G2215/00; G03G2215/00362; G03G2215/00443; G03G2215/00451; G03G2215/00455
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
135 words
A method for electrostatically printing characters which comprises: providing a record carrier; providing an electrode which is constructed as a needle having an area of contact dimensioned for forming a predetermined track width on the record carrier; sliding the electrode against the record carrier under a pressure sufficient to deflect the surface of said record carrier, said sliding step providing no support for the record carrier on the side remote from said electrode and in the immediate region of each of said electrodes; applying selectively controllable pulses during sliding movement between said electrode and said record carrier; whereby the area of contact between said record carrier and said electrode determines the width of a recorded track and the charge density applied to said record carrier is linearly dependent on the voltage applied to said electrode.
Claim 2
Independent Claim
135 words
A method for electrostatically printing characters which comprises: providing a record carrier; providing an electrode which is constructed as a needle having an area of contact dimensioned for forming a predetermined track width on the record carrier; sliding the electrode against the record carrier under a pressure sufficient to deflect the surface of said record carrier, said sliding step providing no support for the record carrier on the side remote from said electrode and in the immediate region of each of said electrodes; applying selectively controllable pulses during sliding movement between said electrode and said record carrier; whereby the area of contact between said record carrier and said electrode determines the width of a recorded track and the charge density applied to said record carrier is linearly dependent on the voltage applied to said electrode.
Claim 3
Dependent Claim
35 words
A method as claimed in claim 1 wherein said record carrier is made of a foil having one face having a very smooth surface and the side disposed remote from said electrode is electrically conductive.
Claim 4
Dependent Claim
16 words
A method as described in claim 2 wherein a DC voltage is applied to said electrode.
Claim 5
Dependent Claim
28 words
A method as described in claim 1 wherein said electrode is carried on a drum mounted on an axis and said drum is selectively movable axially and rotationally.
Claim 6
Dependent Claim
50 words
A method as described in claim 1 further including the step of applying a dc voltage to said needle which causes a charge density on said record carrier that is equal to and of opposite sign to the triboelectric charge density caused by the record carrier sliding over said needle.
Claim 7
Dependent Claim
79 words
Apparatus for electrostatically printing characters on an associated record carrier which comprises: a drum carried on an axis for selective axial and rotational movement having at least one needle shaped electrode extending from the circumferential face thereof and means for holding the associated record carrier against an arcuate section of the circumferential face of said drum without any support for said record carrier on the side remote from said electrode and in the region of each of said electrodes.
Claim 8
Dependent Claim
79 words
Apparatus for electrostatically printing characters on an associated record carrier which comprises: a drum carried on an axis for selective axial and rotational movement having at least one needle shaped electrode extending from the circumferential face thereof and means for holding the associated record carrier against an arcuate section of the circumferential face of said drum without any support for said record carrier on the side remote from said electrode and in the region of each of said electrodes.
Claim 9
Dependent Claim
21 words
The apparatus as described in claim 6 wherein a plurality of additional electrodes are provided on the circumference of said drum.
Claim 10
Dependent Claim
26 words
Apparatus as described in claim 6 wherein said arcuate section of the circumferential portion of said drum has an included angle of no more than 80°.
Claim 11
Dependent Claim
33 words
Apparatus as described in claim 6 further including a plurality of additional associated record carriers and additional means for holding said record carriers against arcuate sections of the circumferential portion of said drum.
Claim 12
Dependent Claim
49 words
The apparatus as described in claim 6 wherein means are provided for applying controllable pulses to said electrode and for synchronizing the actuation of said electrode with the rotary movement of the cylinder, said means for synchronizing including an optically scannable slotted disc and a radially slidable scanning device.
References Cited (Backward Citations)
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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) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |