US3380070A - Electrostatic head - Google Patents

Electrostatic head Download PDF

Info

Publication number
US3380070A
US3380070A US345912A US34591264A US3380070A US 3380070 A US3380070 A US 3380070A US 345912 A US345912 A US 345912A US 34591264 A US34591264 A US 34591264A US 3380070 A US3380070 A US 3380070A
Authority
US
United States
Prior art keywords
head
electrostatic
electrodes
recording
styli
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US345912A
Other languages
English (en)
Inventor
Betts Peter
Everett T Eiselen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to GB1053152D priority Critical patent/GB1053152A/en
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US345912A priority patent/US3380070A/en
Priority to FR5708A priority patent/FR1424786A/fr
Application granted granted Critical
Publication of US3380070A publication Critical patent/US3380070A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/385—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material
    • B41J2/41—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective supply of electric current or selective application of magnetism to a printing or impression-transfer material for electrostatic printing
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/32—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head
    • G03G15/321—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by charge transfer onto the recording material in accordance with the image
    • G03G15/325—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head by charge transfer onto the recording material in accordance with the image using a stylus or a multi-styli array

Definitions

  • An electrostatic head consisting of a plastic block in which wire electrodes are embedded, the electrodes being positioned in ten groups of four, the groups being energized selectively according to the information to be printed and the members of the groups being energized equally and simultaneously.
  • the head is bolted to a moving belt having conductive strips for connection to the electrodes and fastened opposite the head is a U-shaped spring which presses it against the paper at the print station.
  • This invention relates to an improved transducer for use in the art of electrostatic recording and, more particularly, to an electrostatic head construction capable of spot matrix recording on an adjacent electrostatically-sensitive medium.
  • electrical high-voltage pulse signals may be received by an electrostatic head and transformed thereby into electrical fields. These fields are caused to produce statically-charged areas upon the surface of a chargeable medium such as dielectrically coated paper as, for instance, the former moves past the paper station at which a grounded metallic surface contacts the back of the paper. The paper may then be moved to toning, transfer and fixing stations to provide a visible image and copies.
  • a chargeable medium such as dielectrically coated paper
  • the pulse signals may represent characters in several Ways, one of the most common of which is by spot matrix.
  • the character is divided into a matrix of, for example, horizontal rows and 7 vertical columns comprising 70 sections.
  • the head is composed of 10 sections, one corresponding to each row of the character matrix, and as the head moves over the portion of the recording station devoted to the character, each section of the head is pulsed separately in accordance with whether or not the character configuration requires a recording in the corresponding column. In this way a latent image of the character configuration is laid down on the surface of the dielectric paper.
  • the head electrodes are usually of the same configuration for the sections and it has been observed that best resolution of recording is obtained when they are pointed, i.e., in the form of wire ends directed towards the paper. This is believed to be the result of concentration of the electrostatic field in a narrow, collimated beam from the cross-sectional area of the electrode even Where pulsing is at high-speed.
  • the electrostatic head of the present invention which comprises a plurality of wire electrodes embedded in a plastic block, all electrodes being devoted to recording a 10- row column of the character matrix.
  • Four electrodes are connected in parallel and are pulsed simultaneously in each row and thus comprise one stylus; the head therefore contains 10 styli of 4 electrodes each.
  • the electrodes are evenly spaced, the ratio of electrode diameter to the distance between their centers being rigidly prescribed as determined by extensive experimentation to develop opti mum print-out quality.
  • the writing surface adjacent the record medium is highly ground and polished; otherwise, dimensionally, ordinary machine tool tolerance is maintained.
  • the head is adapted for fixing to a moving belt provided with conductive strips, one connecting to each stylus and to which commutation of drive signals may be made elsewhere on the belt. To insure good contact between the writing surface and the record medium, the head carries a loading spring on the other side of the belt.
  • FIGURE 1 shows the head of the present invention associated with portions of an electrostatic printer which energize it and convey it past the record medium;
  • FIGURE 2 is an enlarged view of the head showing its mounting arrangement
  • FIGURE 3 is a view of the writing surface of the head in correspondence with a recorded matrix corresponding to the letter A.
  • Head 10 (FIGURE 3) comprises a rectangular block of suitable molding material of high dielectric strength, preferably of clear stable plastic, in which is embedded a plurality, here forty, of soft iron wire electrodes 12 each about 0.003 inch in diameter on 0.0075 inch centers. Electrodes 12 are arranged in sets of 'four to comprise a total of ten styli, such as stylus 16, in a single alignment along the long dimension of head 10. Stylus 16 is representative and will be referred to specifically although it should be understood that the description applies to the other nine styli as well. Stylus 16 is formed by pressure contact of its four electrodes at junction 18 (FIGURE 2) which connects it to conductive commutation strip 20.
  • Commutation strip 20 is deposited, by electroplating or otherwise, on insulating belt 22; the material of the former may be copper and that of belt 22 may be thin tough plastic, such as polyethylene glycol terephthalate.
  • head 10 is backed up on the other side of belt 22 by loading plate 28, to which it is attached by a pair of machine screws 30.
  • Loading plate 28 is of thin spring steel having a warp as shown at edge 42 and is provided, at its edge opposite stylus 16, with cut-out loading fingers 32, one corresponding to each combination of stylus and its commutation strip, and, at its opposite edge, a curved extension, loading spring 34-.
  • loading plate 28 contributes a lock-washer effect for screws 30 as well as optimum contact between stylus 16 and its commutation strip in the vicinity of junction 18, and optimum closeness between head 10 and record medium 36 (FIGURE 1) backed up by ground plate 38 due to pressure against backing plate 40.
  • rotation of drums 41 and 43 sweeps head 10 past record medium 36 and commutation of signals from source 26 to head 10 is provided through commutation tabs, such as tab 39, mounted at drum 41 so as to contact the commutation strips, such as strip 20.
  • the recording matrix laid down by the head configuration selected for description herein is one of seven columns and ten rows shown in FIGURE 3, the electrostatic charge pattern for the letter A being illustrative. It is obvious that each stylus records a row of the matrix and, it may be surmised that single-electrode styli of large diameter would also provide satisfactory recording. However, considerable experimentation has demonstrated that singleelectrode styli produce printing inconsistent in quality; the styli at the center of the head do not contribute an electrostatic field as strongly as those at the ends. This etfect has been attributed to interaction between styli or charged areas and is minimized for each wire diameter by a minimum spacing of between 1 /2 to 3 times the diameter. This spacing is too distant for good legibility. However, it has been determined that it could be retained if the single-electrode stylus were split, preferably into a four-electrode stylus as in the head structure described above.
  • An electrostatic head capable of recording in the form of a spot matrix as it is conveyed past an electrostatically-sensitive paper positioned at a recording sta tion between a pair of backing plates, comprising:
  • each stylus comprising a plurality of electrodes electrically connected together and to the carrier at one surface of said block and spatially separated at another surface of said block closest to the electrostatically-sensitive paper.
  • said member including a set of spring fingers one opposite each of said styli and a spring extension extending between said block and one of the backing plates whereby said styli are pressed against the electrostatically-sensitive paper when traversing the recording station.
  • means to mount the block on said carrier comprising at last one retaining device passing through said carrier into the block and a spring member including a set of spring fingers along an edge thereof, one finger corresponding to each connecting means, said spring member having a warped configuration for providing a lockwasher effect for said retaining device and concentration of pressure at its fingers.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Dot-Matrix Printers And Others (AREA)
US345912A 1964-02-19 1964-02-19 Electrostatic head Expired - Lifetime US3380070A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB1053152D GB1053152A (enrdf_load_stackoverflow) 1964-02-19
US345912A US3380070A (en) 1964-02-19 1964-02-19 Electrostatic head
FR5708A FR1424786A (fr) 1964-02-19 1965-02-16 Tête électrostatique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US345912A US3380070A (en) 1964-02-19 1964-02-19 Electrostatic head

Publications (1)

Publication Number Publication Date
US3380070A true US3380070A (en) 1968-04-23

Family

ID=23357062

Family Applications (1)

Application Number Title Priority Date Filing Date
US345912A Expired - Lifetime US3380070A (en) 1964-02-19 1964-02-19 Electrostatic head

Country Status (2)

Country Link
US (1) US3380070A (enrdf_load_stackoverflow)
GB (1) GB1053152A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3576585A (en) * 1968-10-24 1971-04-27 Toho Denki Co Ltd Scanning and recording device for electrostatic recording
US3771634A (en) * 1971-05-06 1973-11-13 Bausch & Lomb Surface pattern stylus board
US4012747A (en) * 1975-12-10 1977-03-15 Sperry Rand Corporation Double revolving stylus on continuous belt
US4087826A (en) * 1976-08-02 1978-05-02 Epp Corp. Pulsed electrical printer with dielectrically isolated electrode

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3166752A (en) * 1959-12-04 1965-01-19 Motorola Inc Page printing device utilizing a scanning electrode structure
US3195142A (en) * 1958-04-21 1965-07-13 Burroughs Corp Electrographic recording process and apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3195142A (en) * 1958-04-21 1965-07-13 Burroughs Corp Electrographic recording process and apparatus
US3166752A (en) * 1959-12-04 1965-01-19 Motorola Inc Page printing device utilizing a scanning electrode structure

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3576585A (en) * 1968-10-24 1971-04-27 Toho Denki Co Ltd Scanning and recording device for electrostatic recording
US3771634A (en) * 1971-05-06 1973-11-13 Bausch & Lomb Surface pattern stylus board
US4012747A (en) * 1975-12-10 1977-03-15 Sperry Rand Corporation Double revolving stylus on continuous belt
US4087826A (en) * 1976-08-02 1978-05-02 Epp Corp. Pulsed electrical printer with dielectrically isolated electrode

Also Published As

Publication number Publication date
GB1053152A (enrdf_load_stackoverflow)

Similar Documents

Publication Publication Date Title
US3023731A (en) Electrostatic alphanumerical printer with image transfer mechanism
US3012839A (en) Electrographic printer
EP0013158B1 (en) Electrographic stylus writing apparatus
US3354817A (en) High speed thermal matrix printer
US4122458A (en) Ink jet printer having plural parallel deflection fields
US2715360A (en) Electrical printing apparatus
GB734909A (en) Electrostatic recording of images of characters
US3419886A (en) Electric print-out apparatus
US3380070A (en) Electrostatic head
US3182591A (en) Image forming apparatus and method
US2997361A (en) Selective electrostatic character printing
US3124804A (en) Electrostatic recording head
US4163980A (en) Recording electrode assembly for use in electrostatic reproduction
US3863261A (en) Electrically addressed apertured modulator for electrostatic printing
US3623122A (en) Electric recording apparatus employing liquid developer
US4123762A (en) Improved electrostatic head with toner-repelling electrode
US3787722A (en) Printing apparatus
US3771634A (en) Surface pattern stylus board
US3178718A (en) Electrostatic recording
GB1593000A (en) Ink jet printer charging assemblies
US3012232A (en) High speed printer
US3961574A (en) Electrostatic bar code printer
US3623123A (en) Electrostatic printer
US3886563A (en) Electrostatic printer with movable style
US3068481A (en) Process and apparatus for tesiprinting