GB638141A - Projection screen - Google Patents

Projection screen

Info

Publication number
GB638141A
GB638141A GB29639/46A GB2963946A GB638141A GB 638141 A GB638141 A GB 638141A GB 29639/46 A GB29639/46 A GB 29639/46A GB 2963946 A GB2963946 A GB 2963946A GB 638141 A GB638141 A GB 638141A
Authority
GB
United Kingdom
Prior art keywords
elements
row
screen
tool
oct
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
GB29639/46A
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.)
Space Systems Loral LLC
Original Assignee
Philco Ford Corp
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 Philco Ford Corp filed Critical Philco Ford Corp
Publication of GB638141A publication Critical patent/GB638141A/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
    • G03B21/60—Projection screens characterised by the nature of the surface

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

638,141. Projection screens. PHILCO CORPORATION. Oct. 4, 1946, No. 29639. Convention date, Oct. 5, 1945. [Class 97 (i)] The reflective surface of a projection screen comprises several specularly reflecting elements of such small size as to be beyond the visual resolving power of an observer at the minimum proper viewing distance, the elements being arranged in contiguous relationship and each element being so shaped that the curves of intersection of its surface with planes which are perpendicular to the general plane of the screen and to an axis of symmetry of the element, are cycloids. The elements which may be elongated in form may be arranged in parallel rows and an element of one row may be arranged in staggered relation to the adjacent element of the adjacent row. In one manner of manufacturing the screen, a row of elements is formed by feeding a sheet 1 of suitable material, e.g. wax, at a uniform rate beneath the circular edge of a cutting tool 6 which is rotated about an axis substantially parallel to the plane of the material in a direction opposite to that in which the material is being moved. The next row of elements is formed in the same manner after the tool has been moved relatively to the work material by an indexing machine. The matrix so formed may be provided with a suitable reflective surface to form a screen directly or from this matrix a press tool or die may be made for the production of screens as by stamping or moulding.
GB29639/46A 1945-10-05 1946-10-04 Projection screen Expired GB638141A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US638141XA 1945-10-05 1945-10-05

Publications (1)

Publication Number Publication Date
GB638141A true GB638141A (en) 1950-05-31

Family

ID=22051666

Family Applications (1)

Application Number Title Priority Date Filing Date
GB29639/46A Expired GB638141A (en) 1945-10-05 1946-10-04 Projection screen

Country Status (1)

Country Link
GB (1) GB638141A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005059640A1 (en) * 2003-12-17 2005-06-30 Harry Kurt Hahn Viewing screen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005059640A1 (en) * 2003-12-17 2005-06-30 Harry Kurt Hahn Viewing screen

Similar Documents

Publication Publication Date Title
BR7506524A (en) PROCESS FOR THE PRODUCTION OF FLAT PRINTING WITH LASER RAYS
AT199225B (en) Process for introducing an impurity, which determines the conductivity type, into a semiconductor by vapor-solid diffusion
GB638141A (en) Projection screen
CH304873A (en) Device for feeding tablets in single rows.
BR6803338D0 (en) PROCESS AND APPARATUS FOR GLASS PRODUCTION WITH CERTAIN SURFACE CHARACTERISTICS AND THE GLASS THEREFORE PRODUCED
ES333495A1 (en) Method of fabrication of glass decorative plane. (Machine-translation by Google Translate, not legally binding)
BR7202448D0 (en) A PERFECT PROCESS FOR THE PRODUCTION OF ETHYLENE OXIDE
GB771074A (en) Polarising filter and manufacture thereof
GB1232122A (en)
LU50784A1 (en) Process for the manufacture of thin metal sheets, pierced with a multitude of very small holes and thin metal sheets produced by this process
FR837074A (en) Process for manufacturing cases and the like, and cases obtained by this process
BR6681142D0 (en) PROCESS FOR THE PRODUCTION OF L-LYSINE BY FERMENTATION
GB513363A (en) Improvements in machinery for producing corrugated sheets
ES35319U (en) Plate for making mosaics (Machine-translation by Google Translate, not legally binding)
ES204570A1 (en) A new persistent action machine for the manufacture in honeycomb, of precious stone silicones (Machine-translation by Google Translate, not legally binding)
ES131771U (en) A holder member. (Machine-translation by Google Translate, not legally binding)
ES245444A1 (en) A method of making a cutting element. (Machine-translation by Google Translate, not legally binding)
FR1028509A (en) Process for manufacturing thin papers from vegetable cellulosic materials
BR6804070D0 (en) PROCESS FOR THE PRODUCTION OF L-LYSINE BY FERMENTATION
BR6681347D0 (en) PROCESS FOR MANUFACTURING NEW 9 / B 10O (STEROIDS)
ES406568A1 (en) Apparatus for the manufacture of cazoletas, or semejantes, of synthetic fabric. (Machine-translation by Google Translate, not legally binding)
BR6685451D0 (en) PROCESS FOR THE PREPARATION OF CULTURE FOR THE PRODUCTION OF A NEW ANTIBIOTIC ANTIFUNGO
ES248427A1 (en) Procedure for manufacture of cinematographic screens (Machine-translation by Google Translate, not legally binding)
GB646151A (en) Improvements in methods and apparatus for making die rolls
GB193674A (en) Machine for trimming tin box and the like stampings