| 摘要 |
836,892. Photographic projection-printing apparatus. AGFA A.G. Sept. 12, 1956 [Sept. 21, 1955], No. 27935/56. Class 98(1) In a projection-printing apparatus, a light source which is used without a condenser includes a translucent diffusion surface convexly curved towards the negative plane and so dimensioned and positioned with respect to the negative frame that the straight lines joining points on the negative frame to diametrically opposite points on the edge of the full aperture of the objective intersect the surface or are tangential to it. An electric light source may include a bulb-shaped or tubular diffusion surface and the tubular surface may be that of an incandescent filament lamp or a gas discharge lamp. As shown, an opal lamp 8 is carried in a rotatable socket 12 mounted on an arm 14 which can be displaced along slot 15 perpendicularly to the axis of the objective 6. |
