GB522018A - Improvements in and relating to watermark detectors and the like - Google Patents

Improvements in and relating to watermark detectors and the like

Info

Publication number
GB522018A
GB522018A GB3502638A GB3502638A GB522018A GB 522018 A GB522018 A GB 522018A GB 3502638 A GB3502638 A GB 3502638A GB 3502638 A GB3502638 A GB 3502638A GB 522018 A GB522018 A GB 522018A
Authority
GB
United Kingdom
Prior art keywords
stamp
viewing
aperture
casing
light
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
GB3502638A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB3502638A priority Critical patent/GB522018A/en
Publication of GB522018A publication Critical patent/GB522018A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/34—Paper
    • G01N33/346—Paper paper sheets

Abstract

522,018. Watermark detectors. LEVY, H. Dec. 1, 1938, No. 35026. [Class 97 (i)] A device for viewing postage stamps and the like comprises a casing with a viewing aperture, means to hold a stamp or the like for viewing by light passing through the aperture, and a colour screen in the path of the light. In the apparatus shown, the stamp is held in a holder 23 comprising two hinged strips of transparent material which is slid into guides in the casing, so as to bring the stamp beneath a viewing aperture 6 and above an electric lamp supplied by a dry battery in the casing. A rotatable disc 8 carries colour screens beneath apertures 9 in it, which may be selectively brought into register with the aperture 6 so that the stamp is viewed by light of the desired colour.
GB3502638A 1938-12-01 1938-12-01 Improvements in and relating to watermark detectors and the like Expired GB522018A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3502638A GB522018A (en) 1938-12-01 1938-12-01 Improvements in and relating to watermark detectors and the like

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3502638A GB522018A (en) 1938-12-01 1938-12-01 Improvements in and relating to watermark detectors and the like

Publications (1)

Publication Number Publication Date
GB522018A true GB522018A (en) 1940-06-06

Family

ID=10372916

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3502638A Expired GB522018A (en) 1938-12-01 1938-12-01 Improvements in and relating to watermark detectors and the like

Country Status (1)

Country Link
GB (1) GB522018A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2571188A (en) * 1947-08-28 1951-10-16 Norman A Benson Device for the examination of postage stamps

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2571188A (en) * 1947-08-28 1951-10-16 Norman A Benson Device for the examination of postage stamps

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