| 摘要 |
866,545. Photographic colour or tonal correction. CROSLAND Ltd., J. F. Sept. 21, 1959 [Sept. 24, 1958], No. 30525/58. Class 98 (2) The correction, made more particularly in view of subsequent preparation of printing blocks or cylinders and imperfections in printing inks used therewith, is effected by exposing a phosphor layer to radiation of a first wavelength representing a first image and to radiation of a second wavelength representing the same or a different image, the phosphor being of a kind such that phosphorescence is produced or maintained by the first radiation and at least partly quenched by the second radiation, and then exposing a light-sensitive layer to the light pattern from the phosphor layer. Phosphors for the purpose are indicated by a reference to Levereng's "Luminescence of Solids", the radiations may be ultra violet and infra red, and various manners including simultaneous and sequential application thereof from the same or both sides of the phosphor layer are described. The light-sensitive layer may be present during such application. For colour work the Specification seems mostly to describe correction of a yellow separation negative, through which ultra violet radiation is passed to the phosphor layer followed by infra red radiation through the magenta separation using a spacing for "unsharp" masking effect, after which the photographic layer is developed to a positive. Other procedures include overall exposure of the phosphor layer and the use of orange light. For tonal correction exposures may be made through the same negative in such manner that the middle tones of the picture are reduced, thereby increasing the gradation of the high lights and shadows. Apparatus for the purpose shows, Fig. 1, a "light-integrating unit" 10 to reflect ultra-violet and infra-red radiations from sources 15, 16 respectively downwardly to frame 11 having hinged frames 12, 13, 14 for phosphor layer, separation transparencies to be :corrected and perform correction, and a plate for the final image, serially; while 17 is a mask to avoid direct exposure from the light sources. In Fig. 2 a conveyer 18 is made to carry the frame 11 for the phosphor layer successively beneath frames 12, 13, 14 not this time hinged together with the light-sources 15, 16 arranged above. Figs. 3-7 not shown are directed to various arrangements for simultaneous use of both light sources, with use of these either on opposite sides of the transparency-sensitive surface assembly, or at right angles to each other and with intermediate semi-transparent mirrors.
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