Method of and device for electrostatic printing
| Title: | Method of and device for electrostatic printing |
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| Patent Number: | 4,028,711 |
| Publication Date: | June 07, 1977 |
| Appl. No: | 05/564,305 |
| Application Filed: | April 02, 1975 |
| 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: | Jost, Gerhard (Norderstedt, DT); Rothgordt, Ulf (Norderstedt, DT); Witter, Klaus (Hamburg, DT) |
| Assignees: | U.S. Philips Corporation (New York, NY) |
| Claim: | What is claimed is |
| Claim: | 1. A method for electrostatically printing characters which comprises |
| Claim: | providing a record carrier; |
| Claim: | 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; |
| Claim: | 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; |
| Claim: | applying selectively controllable pulses during sliding movement between said electrode and said record carrier; |
| Claim: | 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. 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: | 3. A method as described in claim 2 wherein a DC voltage is applied to said electrode. |
| Claim: | 4. 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: | 5. 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: | 6. Apparatus for electrostatically printing characters on an associated record carrier which comprises |
| Claim: | 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: | 7. The apparatus as described in claim 6 wherein a plurality of additional electrodes are provided on the circumference of said drum. |
| Claim: | 8. 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.degree.. |
| Claim: | 9. 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: | 10. 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. |
| Current U.S. Class: | 346/153; 346/156; 358/127 |
| Current International Class: | G03G 13044; G03G 13052 |
| Patent References Cited: | 3184749 May 1965 Groth 3329961 July 1967 Schwertz 3349702 October 1967 Nesin 3380069 April 1968 Hojo 3383697 May 1968 Rice 3414723 December 1968 Pleitt 3417404 December 1962 Macovski |
| Primary Examiner: | Lucas, Jay P. |
| Attorney, Agent or Firm: | Trifari, Frank R. Smith, Robert S. |
| Accession Number: | edspgr.04028711 |
| Database: | USPTO Patent Grants |
| Language: | English |
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