GB521853A - Apparatus for the reversal of pictures by an electrical process - Google Patents

Apparatus for the reversal of pictures by an electrical process

Info

Publication number
GB521853A
GB521853A GB34482/38A GB3448238A GB521853A GB 521853 A GB521853 A GB 521853A GB 34482/38 A GB34482/38 A GB 34482/38A GB 3448238 A GB3448238 A GB 3448238A GB 521853 A GB521853 A GB 521853A
Authority
GB
United Kingdom
Prior art keywords
cell
scanning
screen
negative
cathode
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
GB34482/38A
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.)
IG Farbenindustrie AG
Original Assignee
IG Farbenindustrie AG
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 IG Farbenindustrie AG filed Critical IG Farbenindustrie AG
Publication of GB521853A publication Critical patent/GB521853A/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

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Facsimile Scanning Arrangements (AREA)

Abstract

521,853. Local copying by scanning. I. G. FARBENINDUSTRIE AKT.-GES. Nov. 26, 1938, No. 34482. Convention date, Nov. 29, 1937. [Class 40 (iii)] Apparatus for the reversal of pictures comprises a cathode-ray tube B, Fig. 1, the light from the screen F passing through the negative film N, thereby scanning it point by point, to a photo-cell Z which controls by means of the device R and amplifier V the intensity of, or the speed of scanning by, the cathode ray beam so that the quantity of light falling on the cell Z from all points of the picture is substantially the same, a positive of the negative N.appearing on the screen F. The control device R comprises a bridge circuit Z, r<SP>1</SP>, r<SP>2</SP>, rv, Fig. 2. arranged to control the grid-cathode potential in accordance with the light incident on the cell Z. To adjust the gradation of the reversed picture the resistance rv, or a suitable part in the amplifier V, is made variable, or an interchangeable screen may be placed between the negative N and the cell Z. Alternatively the cell Z may be arranged to control the frequency of the time base circuit KG, thus influencing the speed of line scanning.
GB34482/38A 1937-11-29 1938-11-26 Apparatus for the reversal of pictures by an electrical process Expired GB521853A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE521853X 1937-11-29

Publications (1)

Publication Number Publication Date
GB521853A true GB521853A (en) 1940-06-03

Family

ID=6551487

Family Applications (1)

Application Number Title Priority Date Filing Date
GB34482/38A Expired GB521853A (en) 1937-11-29 1938-11-26 Apparatus for the reversal of pictures by an electrical process

Country Status (1)

Country Link
GB (1) GB521853A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2315033B2 (en) * 1972-03-25 1975-11-20 Matsushita Electric Industrial Co., Ltd., Kadoma, Osaka (Japan) IMAGE DISPLAY DEVICE

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2315033B2 (en) * 1972-03-25 1975-11-20 Matsushita Electric Industrial Co., Ltd., Kadoma, Osaka (Japan) IMAGE DISPLAY DEVICE
DE2315033C3 (en) * 1972-03-25 1977-04-14 Matsushita Electric Ind Co Ltd IMAGE DISPLAY DEVICE

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