Abstract
MB. EDWIN H. LAND, president and director of researchof the Polaroid Corporation, demonstrated recently before the Optical Society of America a camera which produces a dry positive on paper 60 sec. after releasing the camera shutter. The camera contains a roll of film of conventional type, except that the support is opaque, and the exposure is made in the usual way. The camera also contains a roll of specially prepared paper which is not sensitive to light. The paper support is also opaque, and has attached, at intervals equal to the length of the picture, capsules containing a viscous solution of the processing materials. This solution includes hydro -quinone and 'hypo' and is released when the capsule is burst on passage of the film and paper between pressure rollers. This takes place after exposure, and the solution is spread as a thin layer between the film and paper, where the following action is said to take place. The hydroquinone rapidly reduces the silver halide in the film in those regions where light action has taken place, thus immobilizing the silver in these regions. In the unexposed regions the 'hypo' takes the silver halide into solution, and diffusion and reduction take place, with the result that silver is deposited in the prepared surface of the paper, producing an image in silver. Since most silver is deposited in the paper in those regions where the least exposure occurs in the camera, the paper image is a positive. The film and paper are pulled apart when the action is complete, yielding a paper 'print' which has a slightly damp surface. The film-paper sandwich passes out of the camera immediately after passing the pressure rollers. The purpose of the opaque supports is to protect the film from further light action while the 'processing' is taking place. In some variants of the system further prints can be obtained from the 'negative', but in general it appears necessary to rephotograph the original to obtain further copies.
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A New Form of Camera. Nature 159, 497 (1947). https://doi.org/10.1038/159497b0
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DOI: https://doi.org/10.1038/159497b0