GB496211A - Improvements in or relating to projection screens - Google Patents
Improvements in or relating to projection screensInfo
- Publication number
- GB496211A GB496211A GB1443137A GB1443137A GB496211A GB 496211 A GB496211 A GB 496211A GB 1443137 A GB1443137 A GB 1443137A GB 1443137 A GB1443137 A GB 1443137A GB 496211 A GB496211 A GB 496211A
- Authority
- GB
- United Kingdom
- Prior art keywords
- roller
- arms
- screen
- spring
- wire
- 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
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)
- Overhead Projectors And Projection Screens (AREA)
Abstract
496,211. Projection screens. WHISTANCE, K. J. May 24, 1937, No. 14431. [Class 97 (i)] A screen is mounted on a roller and attached to a member supported, when the screen is unrolled, by extended pivoted arms or links, a spring being so connected between the roller and the arms that the tensioning of the spring, caused by unrolling of the screen, produces a force tending to cause the arms to assume their extended positions. As shown, the screen 1 is attached to a member 13 held, when the screen is unrolled from the roller 2, by pivoted arms 11, 11<1>, 12, 12<1>. The arms are supported by the tension in a wire &c. 16, secured at 15 to the arm 12, passing over a pulley 18 on the arm 11 and over fixed pulleys 19, 20, and secured to a roller 10. The roller 10 is secured to a shaft 7, coaxial within the roller 2, and connected to it by a spring 5. Unrolling of the screen from the roller 2 tensions the spring 5, thus turning the roller 10 to wind the wire 16 upon it and tension the wire. Adjustable screws 21 prevent the arms from attaining a straight line position. In a modification, the roller 10 is rigidly secured to the roller 2, and a spring, lying horizontally between the arms, connects the wire to the arms. In a further modification the roller is connected by gears to a parallel shaft having worm wheel connection with each of the arms, the spring being housed in one of the gears.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1443137A GB496211A (en) | 1937-05-24 | 1937-05-24 | Improvements in or relating to projection screens |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1443137A GB496211A (en) | 1937-05-24 | 1937-05-24 | Improvements in or relating to projection screens |
Publications (1)
Publication Number | Publication Date |
---|---|
GB496211A true GB496211A (en) | 1938-11-24 |
Family
ID=10041089
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1443137A Expired GB496211A (en) | 1937-05-24 | 1937-05-24 | Improvements in or relating to projection screens |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB496211A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2424287A (en) * | 2005-03-16 | 2006-09-20 | Hae-Yong Choi | Portable screen device with dual shaft structure |
CN112929474A (en) * | 2019-11-06 | 2021-06-08 | Oppo广东移动通信有限公司 | Folding screen assembly and electronic equipment |
CN113568266A (en) * | 2020-04-26 | 2021-10-29 | 青岛海信激光显示股份有限公司 | Projection device |
-
1937
- 1937-05-24 GB GB1443137A patent/GB496211A/en not_active Expired
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2424287A (en) * | 2005-03-16 | 2006-09-20 | Hae-Yong Choi | Portable screen device with dual shaft structure |
GB2432014A (en) * | 2005-03-16 | 2007-05-09 | Hae-Yong Choi | Portable screen device with dual shaft structure |
GB2432228A (en) * | 2005-03-16 | 2007-05-16 | Hae-Yong Choi | Portable screen device with magnetic adjusting means |
GB2432228B (en) * | 2005-03-16 | 2007-09-19 | Hae-Yong Choi | Portable screen device with dual shaft structure |
GB2424287B (en) * | 2005-03-16 | 2007-09-26 | Hae-Yong Choi | Portable screen device with dual shaft structure |
GB2432014B (en) * | 2005-03-16 | 2009-10-21 | Hae-Yong Choi | Portable screen device with dual shaft structure |
CN112929474A (en) * | 2019-11-06 | 2021-06-08 | Oppo广东移动通信有限公司 | Folding screen assembly and electronic equipment |
CN112929474B (en) * | 2019-11-06 | 2023-04-07 | Oppo广东移动通信有限公司 | Folding screen assembly and electronic equipment |
CN113568266A (en) * | 2020-04-26 | 2021-10-29 | 青岛海信激光显示股份有限公司 | Projection device |
CN113568266B (en) * | 2020-04-26 | 2022-05-17 | 青岛海信激光显示股份有限公司 | Projection device |
US20220291578A1 (en) * | 2020-04-26 | 2022-09-15 | Hisense Laser Display Co., Ltd | Projection screen and projection apparatus |
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