GB748915A - Improvements in and relating to optical projection apparatus - Google Patents
Improvements in and relating to optical projection apparatusInfo
- Publication number
- GB748915A GB748915A GB2732152A GB2732152A GB748915A GB 748915 A GB748915 A GB 748915A GB 2732152 A GB2732152 A GB 2732152A GB 2732152 A GB2732152 A GB 2732152A GB 748915 A GB748915 A GB 748915A
- Authority
- GB
- United Kingdom
- Prior art keywords
- stage
- mirror
- window
- pivoted
- objective
- 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
- G03B21/10—Projectors with built-in or built-on screen
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Variable Magnification In Projection-Type Copying Machines (AREA)
- Projection-Type Copiers In General (AREA)
Abstract
748,915. Photographic enlargers. JOHNSONS OF HENDON, Ltd. Oct. 30, 1953 [Oct. 30, 1952], No. 27321/52. Class 98 (1). Photographic projection printing apparatus incorporating illuminating means, a stage for supporting a transparency and having an aperture therein, and an objective, is provided with a mirror between the objective and the stage and close to the stage but at all times clear of the projected beam, and a window such that the operator can see an image of the aperture in the stage in the mirror without interference with the projection of the image on to the receiving surface. As shown, a photographic enlarger comprises a lamp house 16 and negative carrier 42. supported on a base-plate 17 which is slidable along the guide rails 18. A mirror 39 (Fig. 4) is provided in which an operator can see an image of the aperture in the negative carrier by looking through the window 44. Tne mirror is fixed in part of a box comprising two sides 38 and a base 36 to wnich the bellows is attached. The other part of the box comprises the stage 42, window 44 and sides 43 and is pivoted to the first box part at 41. An overcentre spring 45 holds the movable part in either the up or down position. The stage comprises a glass plate 47 on which the negative is placed and an adjustable guide bar 49. A mask support 53 is provided, pivoted to the stage at 54. When the stage is swung downwards, the mask support remains up, being held by magnets 58, 59, and merely slides forward, but it may be swung down by means of the handle 57 for changing the mask. The objective 27 is carried by a lens board 28 which is connected at one end to a bell-crank lever 29, pivoted on the base 17, the other end of the lever moving over a cam surface to give automatic focusing. The projected beam passes through a glass plate 20 and is reflected by a mirror 19 on to the light-sensitive material held against the glass plate 11 by a pressure pad 13. The pad 13 is treadle operated by levers 14, which also operate the light switch. A pilot light may also be provided in the lamphouse for use when centring the negative by means of the mirror. The window 44 may be of non- actinic glass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2732152A GB748915A (en) | 1952-10-30 | 1952-10-30 | Improvements in and relating to optical projection apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2732152A GB748915A (en) | 1952-10-30 | 1952-10-30 | Improvements in and relating to optical projection apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB748915A true GB748915A (en) | 1956-05-16 |
Family
ID=10257685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2732152A Expired GB748915A (en) | 1952-10-30 | 1952-10-30 | Improvements in and relating to optical projection apparatus |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB748915A (en) |
-
1952
- 1952-10-30 GB GB2732152A patent/GB748915A/en not_active Expired
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