GB842788A - Improvements in or relating to apparatus for viewing photographic negatives - Google Patents

Improvements in or relating to apparatus for viewing photographic negatives

Info

Publication number
GB842788A
GB842788A GB981658A GB981658A GB842788A GB 842788 A GB842788 A GB 842788A GB 981658 A GB981658 A GB 981658A GB 981658 A GB981658 A GB 981658A GB 842788 A GB842788 A GB 842788A
Authority
GB
United Kingdom
Prior art keywords
tube
photo
light
cell
screen
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
GB981658A
Inventor
Lawrence Cranmer Bentley
Maxwell Scott
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 GB981658A priority Critical patent/GB842788A/en
Publication of GB842788A publication Critical patent/GB842788A/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
    • G03B27/32—Projection printing apparatus, e.g. enlarger, copying camera
    • G03B27/52—Details
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/222—Studio circuitry; Studio devices; Studio equipment
    • H04N5/257—Picture signal generators using flying-spot scanners

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Processing Of Color Television Signals (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)

Abstract

842,788. Television. RANK CINTEL Ltd. March 25, 1959 [March 27, 1958], No. 9816/58. Class 40(3). Apparatus for viewing a photographic negative 11 comprises a cathode-ray tube 1 for scanning the negative with light rich in blue components, a photo-cell 13 exposed to light passing through the negative, means 15 for applying signals derived from the photo-cell to control the brightness of the spot in tube I, a viewing cathode-ray tube 17 which is scanned synchronously with tube 1 and produces a light rich in yellow components and means 16 for applying the signals from the photo-cell to control the brightness of the spot in tube 17, means 15 and 16 being arranged to permit variation of the relative characteristics of the signals applied to tubes 1 and 17. The signal applied to tube 1 is a gamma-correcting feed-back signal and means 15 comprises an amplifier having an adjustable non-linear characteristic and preferably also a restricted band-width so that the gamma correction is effective only in areas of large detail. The signal applied to tube 17 is arranged to produce a positive image and means 16 comprises an amplifier preferably having an adjustable non- linear characteristic and also including a topboost or crispening circuit to provide aperture correction. The use of blue light from tube 1 permits the use of a short after-glow screen and also takes advantage of the region of maximum efficiency for many photo-cathode materials. The light from the screen of tube 17 includes components to which the human eye is most sensitive. The screen may also be arranged with a long after-glow to reduce flicker. Specification 590, 278 is referred to.
GB981658A 1958-03-27 1958-03-27 Improvements in or relating to apparatus for viewing photographic negatives Expired GB842788A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB981658A GB842788A (en) 1958-03-27 1958-03-27 Improvements in or relating to apparatus for viewing photographic negatives

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB981658A GB842788A (en) 1958-03-27 1958-03-27 Improvements in or relating to apparatus for viewing photographic negatives

Publications (1)

Publication Number Publication Date
GB842788A true GB842788A (en) 1960-07-27

Family

ID=9879331

Family Applications (1)

Application Number Title Priority Date Filing Date
GB981658A Expired GB842788A (en) 1958-03-27 1958-03-27 Improvements in or relating to apparatus for viewing photographic negatives

Country Status (1)

Country Link
GB (1) GB842788A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USB344203I5 (en) * 1972-03-25 1975-01-28

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USB344203I5 (en) * 1972-03-25 1975-01-28
US3928719A (en) * 1972-03-25 1975-12-23 Matsushita Electric Ind Co Ltd Image display system

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