US3664843A - Screen combination - Google Patents

Screen combination Download PDF

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Publication number
US3664843A
US3664843A US44732A US3664843DA US3664843A US 3664843 A US3664843 A US 3664843A US 44732 A US44732 A US 44732A US 3664843D A US3664843D A US 3664843DA US 3664843 A US3664843 A US 3664843A
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US
United States
Prior art keywords
screen
picture
head
dots
relation
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
US44732A
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English (en)
Inventor
Leendert Antonius Fontijn
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.)
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Original Assignee
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
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
Application filed by Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO filed Critical Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Application granted granted Critical
Publication of US3664843A publication Critical patent/US3664843A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/46—Colour picture communication systems
    • H04N1/52—Circuits or arrangements for halftone screening

Definitions

  • Every screen dot of such a screen is obtained at the device described by exposure of a photo-sensitive layer, which is provided on to an etchable substrate, with the aid of an electron beam.
  • a head line of the picture moves according to its own lengthwise direction in a plane perpendicular to the optical axis of the electron gun.
  • a screen By rendering the electron beam for manufacturing specific dots of the screen a declination perpendicular to the said head line and/or in the direction of the said head line of the picture a screen is created with its two head lines slant in relation to the head lines of the picture.
  • the invention relates to a screen combination comprising a basic screen whose screen dots are placed on the angular points of squares and at least one screen rotated in relation to the basic screen, whose screen dots are also placed on angular points of squares.
  • This known combination comprises a screen that is rotated 15 in relation to the basic screen, a screen that is rotated 45 in relation to the basic screen and a screen that is rotated 75 in relation to the basic screen.
  • the object of the invention is such a screen combination and with screen rotations chosenin such a way that the basic screen and the rotated screens can be engraved on a machine simultaneously with modulated signals originating from an original not rotated in relation to the basic screen and attached to the same machine.
  • the invention is preferably applied to a machine with rotating cylinders.
  • the original that has to be scanned is mounted on the jacket of one of the cylinders.
  • the other cylinders are provided on their jackets with a layer to be exposed, which is exposed with a pulsating electron beam.
  • the screen dots to be engraved of rotated screens are not all of them lying on helices; by having small deviations of the electron beam make small deviations, all screen dots can be engraved after all.
  • FIG. 1 represents the screen known in the art mostly suitable for use as basic screen.
  • FIG. 2 a screen according to a diagonal 1 over 1, also suitable as basic screen.
  • FIG. 3 a screen according to a diagonal 1 over 2 to the left or to the right.
  • FIG. 4 a screen according to a diagonal 1 over 3 to the left or to the right.
  • FIG. '5 a screen according to a diagonal 1 over 4 to the left or to the right.
  • FIG. 1 a so-called straight screen is drawn with the head lines parallel to the edges of the picture.
  • a device as described in U.S.A. patent application No. 827,510, for instance, is designable for the above purpose, by mounting to the electron beam exposing apparatus as described in this application a control by means of which the electron beam can be moved in the plane of engraving.
  • the code can originate from a code disc that rotates along with the cylinder on which the original that is to be scanned is mounted.
  • each exposure apparatus still is simultaneously and individually controlled in intensity by means of intensity-modulated colour signals obtained by scanning the original.
  • pitches of the helical scanning and engraving are indicated by the letter S.
  • dot P is also obtained by control by means of coding the electron beam of the engraving machine.
  • the lineature of the 1 over 4 screen shown in FIG. 5 is vm m m 4 T T a first plate having picture points located at the corners of said squares,
  • the lineation of said pattern of squares on each of said plates is formed according to the formula wherein x represents a scale factor, n and p are whole numbers in which n is a function of the lineation of said squares with respect to the edges of the picture.
  • Claim 3 Line 2, cancel 20" and insert --26-.
  • Claim 6 Line 2', after "wherein” insert -p l and--. Line 4, before wherein insert --'in blaok--.
  • Claim 7 Line 2-, after "wherein” insert --p l" and--.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Manufacture Or Reproduction Of Printing Formes (AREA)
US44732A 1969-06-19 1970-06-09 Screen combination Expired - Lifetime US3664843A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6909437A NL6909437A (de) 1969-06-19 1969-06-19

Publications (1)

Publication Number Publication Date
US3664843A true US3664843A (en) 1972-05-23

Family

ID=19807251

Family Applications (1)

Application Number Title Priority Date Filing Date
US44732A Expired - Lifetime US3664843A (en) 1969-06-19 1970-06-09 Screen combination

Country Status (4)

Country Link
US (1) US3664843A (de)
DE (1) DE2030375A1 (de)
GB (1) GB1317942A (de)
NL (1) NL6909437A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4283471A (en) * 1979-11-02 1981-08-11 Sportelli Frank A Printing screen and method of making same
US4394424A (en) * 1981-08-11 1983-07-19 Sportelli Frank A Printing screen and method of making same
US20030060685A1 (en) * 2001-09-06 2003-03-27 Houser Russell A. Superelastic/shape memory tissue stabilizers and surgical instruments

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4924301A (en) * 1988-11-08 1990-05-08 Seecolor Corporation Apparatus and methods for digital halftoning
DE102005031784A1 (de) * 2005-07-07 2007-01-11 Zero-Point-Systems Günther Stark GmbH Schnellspann-Vorrichtung mit Austauschzylinder

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4283471A (en) * 1979-11-02 1981-08-11 Sportelli Frank A Printing screen and method of making same
US4394424A (en) * 1981-08-11 1983-07-19 Sportelli Frank A Printing screen and method of making same
US20030060685A1 (en) * 2001-09-06 2003-03-27 Houser Russell A. Superelastic/shape memory tissue stabilizers and surgical instruments

Also Published As

Publication number Publication date
NL6909437A (de) 1970-12-22
DE2030375A1 (de) 1971-01-14
GB1317942A (en) 1973-05-23

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