GB834025A - Improvements in or relating to apparatus for printing photographic negatives - Google Patents

Improvements in or relating to apparatus for printing photographic negatives

Info

Publication number
GB834025A
GB834025A GB2429056A GB2429056A GB834025A GB 834025 A GB834025 A GB 834025A GB 2429056 A GB2429056 A GB 2429056A GB 2429056 A GB2429056 A GB 2429056A GB 834025 A GB834025 A GB 834025A
Authority
GB
United Kingdom
Prior art keywords
light
control
aug
photo
sum
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
GB2429056A
Inventor
George Stanley Elphick
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.)
Rank Cintel Ltd
Original Assignee
Rank Cintel Ltd
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 Rank Cintel Ltd filed Critical Rank Cintel Ltd
Priority to GB2429056A priority Critical patent/GB834025A/en
Publication of GB834025A publication Critical patent/GB834025A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B27/00—Photographic printing apparatus
    • G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
    • G03B27/725—Optical projection devices wherein the contrast is controlled electrically (e.g. cathode ray tube masking)

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Of Exposure In Printing And Copying (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)

Abstract

834,025. Photo-electric printing control. RANK CINTEL Ltd. Aug. 8, 1957 [Aug. 8, 1956], No. 24290/56. Class 40 (3). In photographic printing apparatus in which a scanning spot of light from a cathode-ray tube 2 is focused through a negative 4 on to printing paper 9 and in which part of the light is reflected by a half-silvered mirror 5 on to a photo-cell 7 which feeds back to the cathoderay tube 2 to control its brightness through an amplifier 13, an integrating circuit 14 and either directly by the dotted line 15, or through a non-linear amplifier 16 which is adjustable to suit different negative densities and is controlled by deflection generator circuits 11, 12 which determine the position of the light spot. The non-linear control by the circuits 11, 12 may be obtained by taking their sum, the sum of their square or the square root of this.
GB2429056A 1956-08-08 1956-08-08 Improvements in or relating to apparatus for printing photographic negatives Expired GB834025A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2429056A GB834025A (en) 1956-08-08 1956-08-08 Improvements in or relating to apparatus for printing photographic negatives

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2429056A GB834025A (en) 1956-08-08 1956-08-08 Improvements in or relating to apparatus for printing photographic negatives

Publications (1)

Publication Number Publication Date
GB834025A true GB834025A (en) 1960-05-04

Family

ID=10209358

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2429056A Expired GB834025A (en) 1956-08-08 1956-08-08 Improvements in or relating to apparatus for printing photographic negatives

Country Status (1)

Country Link
GB (1) GB834025A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4457618A (en) * 1982-07-01 1984-07-03 Polaroid Corporation Optical system for use in electronic enlarger
USRE33973E (en) * 1987-01-08 1992-06-23 Management Graphics, Inc. Image generator having automatic alignment method and apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4457618A (en) * 1982-07-01 1984-07-03 Polaroid Corporation Optical system for use in electronic enlarger
USRE33973E (en) * 1987-01-08 1992-06-23 Management Graphics, Inc. Image generator having automatic alignment method and apparatus

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