GB563028A - Improvements in or relating to the production of photo-mechanical printing plates - Google Patents

Improvements in or relating to the production of photo-mechanical printing plates

Info

Publication number
GB563028A
GB563028A GB105843A GB105843A GB563028A GB 563028 A GB563028 A GB 563028A GB 105843 A GB105843 A GB 105843A GB 105843 A GB105843 A GB 105843A GB 563028 A GB563028 A GB 563028A
Authority
GB
United Kingdom
Prior art keywords
stop
exposure
stops
combination
given
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
Application number
GB105843A
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.)
ARTHUR ERNEST FIELD
Original Assignee
ARTHUR ERNEST FIELD
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 ARTHUR ERNEST FIELD filed Critical ARTHUR ERNEST FIELD
Priority to GB105843A priority Critical patent/GB563028A/en
Publication of GB563028A publication Critical patent/GB563028A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F5/00—Screening processes; Screens therefor
    • G03F5/02—Screening processes; Screens therefor by projection methods
    • G03F5/06—Screening processes; Screens therefor by projection methods changing the diaphragm effect

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Preparing Plates And Mask In Photomechanical Process (AREA)

Abstract

563,028. Half-tone photo-mechanical printing-plates. FIELD, A. E. Jan. 21, 1943, No. 1058. [Class 98 (ii)] A method of producing a half-tone photographic plate includes the step of making an exposure, either successively or simultaneously, through a segmented stop (i.e. a stop wherein the periphery of the aperture comprises or includes a series of inwardly directed projections) and through a non-circular stop, which may be a square or another segmented stop. A circular stop may be used in addition. The aperture may be in the form of a cross, the arms of which are substantially parallel-sided (Fig. 1), or in the form of a cross, each of the arms of which is constituted by a triangle having one of its angles directed toward the centre (Fig. 2), or as shown in Figs. 3, 4 or 5. Two or more stops according to the invention may be used in combination. The stops, when used by themselves or in combination with circular or square stops, may be moved either circularly or laterally, or by a combination of these movements, in their own plane, successive exposures being given for each position of the stop. The stops may be used in. front of, between, or behind the lenses. A stop according to the invention may be used in combination with an iris stop. A fringing effect is produced round the outer portion of the dots, the centre portions being more intense. Various exposures to take account of the tones of the picture may be given. Five successive exposures may be given, change being effected between each exposure ; the fifth exposure may be a flash exposure for black originals. A general exposure may be given with a square stop followed by a second exposure with a segmental stop for the purpose of contrast control. Successive exposures with movement reduce moire. The stops may be made from metal or wood, or may be produced photographically on glass or other transparent material ; a graduated effect may be produced in the latter case. A half-tone screen or a parallel-line grid may be placed in or over the aperture. Specification 431,384 is referred to. According to the Provisional Specification, a segmented stop may be used alone or in combination with a circular stop.
GB105843A 1943-01-21 1943-01-21 Improvements in or relating to the production of photo-mechanical printing plates Expired GB563028A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB105843A GB563028A (en) 1943-01-21 1943-01-21 Improvements in or relating to the production of photo-mechanical printing plates

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB105843A GB563028A (en) 1943-01-21 1943-01-21 Improvements in or relating to the production of photo-mechanical printing plates

Publications (1)

Publication Number Publication Date
GB563028A true GB563028A (en) 1944-07-26

Family

ID=9715439

Family Applications (1)

Application Number Title Priority Date Filing Date
GB105843A Expired GB563028A (en) 1943-01-21 1943-01-21 Improvements in or relating to the production of photo-mechanical printing plates

Country Status (1)

Country Link
GB (1) GB563028A (en)

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