GB666222A - Improvements in or relating to optical lenses - Google Patents

Improvements in or relating to optical lenses

Info

Publication number
GB666222A
GB666222A GB2041748A GB2041748A GB666222A GB 666222 A GB666222 A GB 666222A GB 2041748 A GB2041748 A GB 2041748A GB 2041748 A GB2041748 A GB 2041748A GB 666222 A GB666222 A GB 666222A
Authority
GB
United Kingdom
Prior art keywords
elements
lens
screen
face
angles
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
GB2041748A
Inventor
Leonard Francis Broadway
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.)
EMI Ltd
Electrical and Musical Industries Ltd
Original Assignee
EMI Ltd
Electrical and Musical Industries 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 EMI Ltd, Electrical and Musical Industries Ltd filed Critical EMI Ltd
Priority to GB2041748A priority Critical patent/GB666222A/en
Publication of GB666222A publication Critical patent/GB666222A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/02—Simple or compound lenses with non-spherical faces
    • G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Overhead Projectors And Projection Screens (AREA)

Abstract

666,222. Lenses; projection screens. ELECTRIC & MUSICAL INDUSTRIES, Ltd. July 30, 1949 [July 31, 1948], No. 20417/48. Class 97 (i). Rectilinear prismatic elements are formed on both sides of a light-transmitting sheet, the elements on one side being at right-angles to those on the other, the angles of the elements increasing towards the perimeter of the sheet so as to form a Fresnel lens. The lens may be associated with a projection screen comprising a light-transmitting sheet having parallel cylindrical lenses on one surface and other parallel cylindrical lenses on the other surface at right angles to those on the first. Fig. 1 shows a cross-section, in one direction, of a combination of lens and screen, Fig. 2 being a section in a perpendicular direction. The screen 1 has semi-cylindrical elements 2 on one face and arcuate cylindrical elements 3 on the other face which may be silvered if a reflecting screen is required. The lens 6 has prismatic elements 7, on one face, of the same pitch as the screen elements 2. Similar prismatic elements 8 on the opposite face of the lens correspond to the screen elements 3. The centre of the lens may be left plane.
GB2041748A 1948-07-31 1948-07-31 Improvements in or relating to optical lenses Expired GB666222A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2041748A GB666222A (en) 1948-07-31 1948-07-31 Improvements in or relating to optical lenses

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2041748A GB666222A (en) 1948-07-31 1948-07-31 Improvements in or relating to optical lenses

Publications (1)

Publication Number Publication Date
GB666222A true GB666222A (en) 1952-02-06

Family

ID=10145604

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2041748A Expired GB666222A (en) 1948-07-31 1948-07-31 Improvements in or relating to optical lenses

Country Status (1)

Country Link
GB (1) GB666222A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580661A (en) * 1969-04-10 1971-05-25 Bell & Howell Co Rear projection viewing screen for close viewing
US3598470A (en) * 1969-11-05 1971-08-10 Prismalite Inc Projection screen and system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3580661A (en) * 1969-04-10 1971-05-25 Bell & Howell Co Rear projection viewing screen for close viewing
US3598470A (en) * 1969-11-05 1971-08-10 Prismalite Inc Projection screen and system

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