Negative brightness values display - involves scanning of film transparency by image of spot on CRT screen and feeding inverted signal to brightness control

摘要

The system may be used to display negative brightness value and complementary colours of a colour picture on a developed film. The pattern on the screen (7) of a T.V. receiver (1) is projected by a lens system (6) on the film (8) so that the film is scanned by an image of the spot on the T.V. tube. Light passing through the film is concentrated by a lens (9) on an electronic photosensitive component (10) in the focal plane of the lens (1). The amplified output signal from the photosensor (10) is applied to the aerial input (4) of the T.V. receiver through an h.f. stage (12) which can be modulated, or directly to the video stage (3) so that an output signal corresponding to the film dark area brightens the corresponding point of the CRT screen.