GB899969A - Improvements in or relating to colour television systems - Google Patents

Abstract

899,969. Colour and stereoscopic television. MULLARD Ltd. April 27, 1960 [July 3, 1959], No. 22959/59. Class 40(3) A combined colour and stereoscopic television system comprises means for transmitting on a first channel simultaneous or dot-sequential signals representing two out of three colour components of the first coloured image of a stereoscopic pair, means for transmitting on a second channel, simultaneously with the signals on the first, signals representing the remaining colour component of the second coloured image of the stereoscopic pair, and means for reconstituting and displaying said signals as superimposed or interleaved images in corresponding colours. An observer wearing spectacles, comprising for one eye a filter for the colour component(s) from the first image and for the other eye a filter for the remaining colour component from the second image, sees a stereoscopic image. Furthermore, since the brain integrates the coloured information received through the two eyes, an illusion of a complete coloured picture is created. In the preferred arrangement illustrated the transmitter employs two cameras which view the image O over paths inclined at an appropriate angle α, one camera having a signal pick-up tube Cg which produces signals representative of the green component of the left-hand view, and the other camera having two pick-up tubes Cr and Cb which produce signals representative respectively of the red and blue components of the right-hand view. The signals are transmitted simultaneously over channels G, R and B to a receiver where they cause reproduction of superimposed or interleaved images in corresponding colours. The image reproducer may comprise a "Lawrence" tube, a single-gun, stripedscreen tube, a combination of three tubes, one for each colour, or, as illustrated, a three-gun shadow-mask tube. Spectacles for viewing the reproduced image comprise a filter Fg to pass green light to the left eye and a filter Frb to pass red and blue light to the right eye. The system loses the stereoscopic effect in saturated areas, and according to a modification this is avoided by presenting finer detail stereoscopically to both eyes. Two additional pick-up tubes are associated with tube Cg to obtain the higher frequencies of the red and blue components of the left-hand view. The green channel then conveys the combined signals comprising the green low frequencies and "mixed highs" due to green, red and blue. All these signals are displayed in green at the receiver. An additional pick-up tube is added to camera Cr, Cb to obtain the high frequencies of the green component of the right-hand image and these are added to the signals in both channels R and B so as to be reproduced in both red and blue. It is stated that the signals in channel G in this modification may be employed to produce a non-stereoscopic black- and-white image.