Constant temp. unit for polaroid camera film - comprises electrical resistance heating metal wall of camera by radiation

摘要

The equipment heats and keeps a black-and-white colour film of the instant-development type as used in polaroid cameras to 25 deg. + 0.5 deg. C. It comprises an electrical resistance in a cylinder (1) placed against the base (3) of the camera so as to heat its metal wall by radiation. The resistance can comprise a series of metal strips forming a sleeve round the camera viewing axis, or a thick aluminium plate containing elements and held against the back containing the film. The resistance heating system is adaptable for a means supply of 110 or 220 volts, an accumulator or a car battery.