GB779722A - Improvements in projection screens - Google Patents

Improvements in projection screens

Info

Publication number
GB779722A
GB779722A GB1772255A GB1772255A GB779722A GB 779722 A GB779722 A GB 779722A GB 1772255 A GB1772255 A GB 1772255A GB 1772255 A GB1772255 A GB 1772255A GB 779722 A GB779722 A GB 779722A
Authority
GB
United Kingdom
Prior art keywords
links
base
screen
pivots
strut
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
GB1772255A
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 GB1772255A priority Critical patent/GB779722A/en
Publication of GB779722A publication Critical patent/GB779722A/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
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/54—Accessories
    • G03B21/56—Projection screens
    • G03B21/58—Projection screens collapsible, e.g. foldable; of variable area

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
  • Eye Examination Apparatus (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)

Abstract

779,722. Projection screens. DENTON, J. M. Nov. 23, 1955 [June 20, 1955], No. 17722/55. Class 97(1) A flexible sheet projection screen 5 carried by a spring loaded roller 3 on a base 1 and having its outer end secured to a cross bar 6 parallel to the base, is supported by a crossed and co-planar pair of spring loaded, toggle jointed struts, each strut consisting of two equal arms, pivoted by their outer ends to the base and cross bar respectively at the same side of the screen, and converging towards the other side of the screen to cross the corresponding arms of the other strut and meet at their toggle joint beyond and in the same plane as the toggle joint of the other strut. In the form shown pairs of pivoted links 7, 8, 7a, 8a are jointed at 9, 9a. The links 7, 7a are bifurcated to permit the pairs of links to cross and are extended beyond the pivots and connected by springs 10, 10a to the links 8, 8a at points 11, 11a which may be adjustable along the links. The tension springs may be replaced by compression springs acting between the base and the links or by torsion springs at the pivots. Frictional clamps or detents may be provided at the pivots to limit the extension of the screen.
GB1772255A 1955-06-20 1955-06-20 Improvements in projection screens Expired GB779722A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1772255A GB779722A (en) 1955-06-20 1955-06-20 Improvements in projection screens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1772255A GB779722A (en) 1955-06-20 1955-06-20 Improvements in projection screens

Publications (1)

Publication Number Publication Date
GB779722A true GB779722A (en) 1957-07-24

Family

ID=10100077

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1772255A Expired GB779722A (en) 1955-06-20 1955-06-20 Improvements in projection screens

Country Status (1)

Country Link
GB (1) GB779722A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0901038A2 (en) * 1997-09-05 1999-03-10 Izumi-Cosmo Co., Ltd. Portable projection screen
EP0984321A1 (en) * 1998-08-20 2000-03-08 Izumi-Cosmo Co., Ltd. Portable projection screen assembly
WO2005076071A1 (en) * 2004-02-05 2005-08-18 Ju Suk No Portable screen device
EP2037322A1 (en) * 2007-09-11 2009-03-18 Seiko Epson Corporation Screen

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0901038A2 (en) * 1997-09-05 1999-03-10 Izumi-Cosmo Co., Ltd. Portable projection screen
EP0901038A3 (en) * 1997-09-05 2002-05-22 Izumi-Cosmo Co., Ltd. Portable projection screen
EP0984321A1 (en) * 1998-08-20 2000-03-08 Izumi-Cosmo Co., Ltd. Portable projection screen assembly
WO2005076071A1 (en) * 2004-02-05 2005-08-18 Ju Suk No Portable screen device
EP2037322A1 (en) * 2007-09-11 2009-03-18 Seiko Epson Corporation Screen
US7894132B2 (en) 2007-09-11 2011-02-22 Seiko Epson Corporation Screen

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