US3301947A - Electrostatic image copier having photoconductive element switching - Google Patents

Electrostatic image copier having photoconductive element switching Download PDF

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Publication number
US3301947A
US3301947A US269671A US26967163A US3301947A US 3301947 A US3301947 A US 3301947A US 269671 A US269671 A US 269671A US 26967163 A US26967163 A US 26967163A US 3301947 A US3301947 A US 3301947A
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US
United States
Prior art keywords
light
electrostatic
source
image
elements
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
US269671A
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English (en)
Inventor
Joseph J Stone
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.)
AB Dick Co
Original Assignee
AB Dick Co
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 NL303014D priority Critical patent/NL303014A/xx
Priority to BE645997D priority patent/BE645997A/xx
Application filed by AB Dick Co filed Critical AB Dick Co
Priority to US269671A priority patent/US3301947A/en
Priority to GB88/64A priority patent/GB995816A/en
Priority to DED43381A priority patent/DE1279466B/de
Priority to FR963254A priority patent/FR1391187A/fr
Application granted granted Critical
Publication of US3301947A publication Critical patent/US3301947A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • G03G15/05—Apparatus for electrographic processes using a charge pattern for imagewise charging, e.g. photoconductive control screen, optically activated charging means

Definitions

  • the response of the electrostatic transducer usually determines the end result, and not much can be done to compensate for variables, such as variable linearity, background color changes on the document which the data is written, or poor contrast problems. Nor can much be done for altering color sensitivity or selectivity of these prior art electrostatic transducers.
  • An object of this invention is the provision of an electrostatic writing system which permits compensation for the characteristics of the electrostatic writing transducer.
  • Yet another object of the present invention is the pro- 1 vision of the novel electrostatic writing system wherein it is possible to obtain a desired response within the writing system.
  • Still another object of the present invention is the proyision of a novel, useful and inexpensive electrostatic writing system.
  • an electrostatic writing system of the type wherein the electrostatic transducer effectively comprises 7 a plurality of separate photoconductive cells which are in the current path for depositing electrostatic charges on the writing medium.
  • the electrostatic transducer effectively comprises 7 a plurality of separate photoconductive cells which are in the current path for depositing electrostatic charges on the writing medium.
  • light from a constant source of illumination is permitted to successively fall upon each one of the photoconductive cells or elements while the amplitude of the biasing current source is varied in response to light from the documentwhich is being synchronously scanned.
  • the constant light source serves to turn on each photoresistive element, much in the manner of a switch being closed whereby a current can flow therethrough hav ing an amplitude determined by the light reflected from the picture element on the document being scanned at the time.
  • the electrostatic charge'deposition which occurs is a function of the amount of current flowing.
  • FIGURE 1 is an isometric view of an embodiment of the invention
  • FIGURE 2 is a cross section of an electrostatic transducer of a type suitable for use with this invention.
  • FIGURE 3 is another embodiment in accordance with this invention.
  • FIGURE 1 is an isometric view of an embodiment of this invention.
  • a document 10 which is to be scanned is mounted upon a drum 12, in any suitable manner. Adjacent the location of the document 10 and extending around the drum surface is a translucent strip 14.
  • a light source 16 which shines light through a small spot designated as 16A, through the translucent ring area.
  • a lens 18, focuses a line of the image on the document 10 as well as the spot of light adjacent thereto upon a rotating many sided mirror 20.
  • a drive source 22 drives the drum and mirror synchronously with one another.
  • the mirror serves to pass a spot of light followed by the line of data across a photocell 24, and across an electrostatic image transducer 26, positioned adjacent thereto.
  • the image transducer 26 comprises a plurality of photoresistive cells extending across the image converter portion 26A,- of the electrostatic transducer. Spaced from the back surface of the image converter, is a conductive back bar 26B. Paper of any other suitable medium 28, upon which it is desired to write, passes between the image converter 26A and the back bar 268 and receives an electrostatic charge deposition thereon.
  • the mirror is rotated in a manner so that it will successively reflect successive lines from the document on the drum past the cells on the image converter.
  • the spot of light is made sufficiently bright or intense to render each one of these cells upon which it falls as highly con-
  • the output of the photocell 24 is applied to a video signal amplifier 30.
  • the video signal amplifier output is applied to the image transducer 26A.
  • a radio frequency signal source 32 has its output connected -to the back bar 26B.
  • FIGURE 2 there may be seen a cross section of the image transducer 26.
  • This includes a glass or other suitable insulator 34, through which a plurality of tiny holes have been drilled.
  • a wire 36A, 36B, 36C, for example, is inserted in each one of these holes and then is finished ofl flush with the surface of the dielectric 34. Thereafter, a portion of the wire is etched away from one surface of the substrate. The etched away region is then filled with a photoconductive material 38A,
  • the radio frequency signal source 32 is connected to the back bar. It has been found that a radio frequency signal when applied to the back bar, reduces the video signal levels required and linearizes the response of the system from the video level to the recorded electrostatic image.
  • the photocell 24 provides an output signal in response to a picture element which is made to shine thereon.
  • the output signal is applied to the video signal and amplifier 30 which applies a current through the photoconductive element hav-
  • the paper 28, with the charge pattern thereon, representativeof the line of elements which have been scanned, is moved under a paper processing station 42, which serves the function of developing the electrostatic image in accordance with well known techniques.
  • FIGURE 3 shows another arrangement for the embodiment of the invention which is simpler in construction.
  • Both the gear box 58 and the mirror 52 are synchronously driven from a drive source 610.
  • An image transducer 62 is identical with theima-ge transducer 26A and is connected to receive the output of a video signal amplifier 64.
  • the video signal amplifier is driven from the output of the photoelectric cell 54.
  • a radio frequency signal source 66 applies its output to a back bar 68, as before.
  • the many sided mirror 52 rotates, it successively refleets a column of the light variations from the document 10 past the photoelectric cell 54. Simultaneously, the-rer with, light from the source 50 is caused to traverse the image converter 62.
  • the operation of the. arrangement for depositing an electrostatic charge upon the paper 70 is identical with that described in connection with FIG- URE. 1.
  • the photoelectric cell 54 is caused to move linearly along the edge of the document 10 whereby the successive columns of picture elements upon the document may be passed by the photoelectric cell. These successive columns of picture elements are recorded as electrostatic charge patterns on the paper 70.
  • the signal applied to the image converter is amplified, many things may be accomplished with'it, such as providing a simple mechanism for achieving the positive or a negative image by switching in or removing inverting stages in the amplifier.
  • the gain may be adjusted to provide for better linearity thereby more linear results are achieved.
  • clipping may be introduced, whereby signals below a certain level produce only white images and signals above the predetermined level produce dark images. Because of the wide spectral response achieveable with photoelectric cells as contrasted to the limited spectral response of photoconductive materials, this system of operating an electrostatic transducer can be made to respond to an extremely wide band range of colors as well as to a very narrow spectral range.
  • an electrostatic image transducer of the type comprising a plurality of photoconductive elements each of which is in the electrical current path employed for depositing electrostatic charges on said medium representative of light image variations, the improvement comprising a source of electrical current, a single photocell connecting said source of electrical current to all of said photoconductive elements, a source of light having a fixed level of illumination, and means for successively illuminating said photoconductive elements with light from said light source while applying light from successive picture elements to said single photocell for controlling the current flowing successively through each photoconductive element from said current source responsive to light variations.
  • Apparatus for converting the information on a document into an electrostatic charge pattern on a medium comprising means for depositing electrostatic charges on said medium responsive to light variations including a pluralty of photoconductive elements, a source of operating current for said photoconductive elements, means for controlling the amplitude of said operating current responsive to light variations including a single photocell connected to all of said photoconductive elements, a
  • a system for reproducing the data on a document as an electrostatic charge pattern on a medium comprising a light to an electrostatic image transducer including I a plurality of separate photoconductive elements, a conductive bar spaced form said photoconductive elements, means for generating signals at a radio frequency, means for deriving video signals from the data on said document, and means for simultaneously applying said radio fre-' quency signals to said bar while applying said video signals across said plurality of photo conductive elements.
  • a system for reproducing the data on a document as an electrostatic charge pattern on a medium comprising a light to an electrostatic image transducer including a plurality of separate photoconductive elements arranged in a line, and a conductive barspaced from said line of photoconductive elements, said inedium passing between said line of photoconductive elements and said bar,means for applying signals at a radio frequency to said bar, a
  • said References Cited by the Examiner means for successively illuminating said photoconductive UNITED STATES PATENTS elements from said light source while illuminating said 5 photocell with the successive picture elements from said 31205302 9/1965 Quade document comprises a many sided rotating mirror and means for positioning said mirror for reflecting light from DAVID REDINBAUGH Prlmary Examine" said light source and light from said document respectively H. W. BRITION, Assistant Examiner.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Photoreceptors In Electrophotography (AREA)
US269671A 1963-04-01 1963-04-01 Electrostatic image copier having photoconductive element switching Expired - Lifetime US3301947A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NL303014D NL303014A (cs) 1963-04-01
BE645997D BE645997A (cs) 1963-04-01
US269671A US3301947A (en) 1963-04-01 1963-04-01 Electrostatic image copier having photoconductive element switching
GB88/64A GB995816A (en) 1963-04-01 1964-01-01 Improvements in or relating to electrostatic image copier
DED43381A DE1279466B (de) 1963-04-01 1964-01-16 Elektrographisches Kopiergeraet
FR963254A FR1391187A (fr) 1963-04-01 1964-02-11 Dispositif de reproduction électrostatique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US269671A US3301947A (en) 1963-04-01 1963-04-01 Electrostatic image copier having photoconductive element switching

Publications (1)

Publication Number Publication Date
US3301947A true US3301947A (en) 1967-01-31

Family

ID=23028215

Family Applications (1)

Application Number Title Priority Date Filing Date
US269671A Expired - Lifetime US3301947A (en) 1963-04-01 1963-04-01 Electrostatic image copier having photoconductive element switching

Country Status (6)

Country Link
US (1) US3301947A (cs)
BE (1) BE645997A (cs)
DE (1) DE1279466B (cs)
FR (1) FR1391187A (cs)
GB (1) GB995816A (cs)
NL (1) NL303014A (cs)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3346701A (en) * 1963-07-05 1967-10-10 Iit Res Inst Electrostatic recording system employing photoconductive electrodes
US3396235A (en) * 1963-09-09 1968-08-06 Xerox Corp Xerographic facsimile printer having light scanning and electrical charging
US3424862A (en) * 1965-09-07 1969-01-28 Itt Printing cathode ray tube apparatus
US3426354A (en) * 1964-06-01 1969-02-04 Xerox Corp Electrostatic charge image recorder
US3734608A (en) * 1970-03-16 1973-05-22 Eastman Kodak Co Machine programmer
JPS514566Y1 (cs) * 1974-07-23 1976-02-09
US4205321A (en) * 1978-10-02 1980-05-27 Eastman Kodak Company DC Biased stylus for electrostatic recording

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3869569A (en) * 1972-05-16 1975-03-04 Xerox Corp Facsimile transceiving apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205302A (en) * 1962-11-02 1965-09-07 Ibm Facsimile transmission system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205302A (en) * 1962-11-02 1965-09-07 Ibm Facsimile transmission system

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3346701A (en) * 1963-07-05 1967-10-10 Iit Res Inst Electrostatic recording system employing photoconductive electrodes
US3396235A (en) * 1963-09-09 1968-08-06 Xerox Corp Xerographic facsimile printer having light scanning and electrical charging
US3426354A (en) * 1964-06-01 1969-02-04 Xerox Corp Electrostatic charge image recorder
US3424862A (en) * 1965-09-07 1969-01-28 Itt Printing cathode ray tube apparatus
US3734608A (en) * 1970-03-16 1973-05-22 Eastman Kodak Co Machine programmer
JPS514566Y1 (cs) * 1974-07-23 1976-02-09
US4205321A (en) * 1978-10-02 1980-05-27 Eastman Kodak Company DC Biased stylus for electrostatic recording

Also Published As

Publication number Publication date
DE1279466B (de) 1968-10-03
FR1391187A (fr) 1965-03-05
GB995816A (en) 1965-06-23
NL303014A (cs)
BE645997A (cs)

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