GB345925A - Improvements in and connected with projection screens - Google Patents
Improvements in and connected with projection screensInfo
- Publication number
- GB345925A GB345925A GB2757130A GB2757130A GB345925A GB 345925 A GB345925 A GB 345925A GB 2757130 A GB2757130 A GB 2757130A GB 2757130 A GB2757130 A GB 2757130A GB 345925 A GB345925 A GB 345925A
- Authority
- GB
- United Kingdom
- Prior art keywords
- lid
- box
- screen
- roller
- secured
- 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
Abstract
345,925. Projection screens. HUNTER, R. F., BLACKBURN, A., and NAGEL, H., 40, Doughty Street, London. Sept. 15, 1930, No. 27571. [Class 97 (i).] A projection screen A is carried by a spring roller B mounted within a box E, the free end of the screen being attached to a lid member H, and the lid and box being connected by a screen-stretching device which is housed within the box when the screen is not in use. The stretcher may comprise two struts L, K, the strut L being pivoted to the lid at O and provided with a pin P, or a roller, movable in a slotted guide Q secured in the box, and the strut K comprising two parallel bars pivoted at one end within the box and carrying, at the other end a pin M, or a roller, moving in a slotted guide N secured to the lid. A spring catch R engages the pin M to hold the screen in extended position, and may be released by a sliding finger-piece S carrying a cam T. The box is also provided with one or more notched projections I each engaging in a hole J when the lid is closed, and a slotted plate, sliding within the lid under spring action, and secured to the finger-piece S, may engage each notch to secure the lid in closed position. One of the blocks C forming bearings for the spindles of the roller B may be slotted so that the position of the spindle may be adjusted therein by means of a screw X to equalize the tension of the stretched screen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2757130A GB345925A (en) | 1930-09-15 | 1930-09-15 | Improvements in and connected with projection screens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2757130A GB345925A (en) | 1930-09-15 | 1930-09-15 | Improvements in and connected with projection screens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB345925A true GB345925A (en) | 1931-04-02 |
Family
ID=10261783
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2757130A Expired GB345925A (en) | 1930-09-15 | 1930-09-15 | Improvements in and connected with projection screens |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB345925A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104455983A (en) * | 2014-11-28 | 2015-03-25 | 海信集团有限公司 | Screen levelness adjusting mechanism and projection display device |
-
1930
- 1930-09-15 GB GB2757130A patent/GB345925A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104455983A (en) * | 2014-11-28 | 2015-03-25 | 海信集团有限公司 | Screen levelness adjusting mechanism and projection display device |
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