PRECISE COLOR TELEVISION TRANSMISSION DEVICE, TRANSMITTER AND RECEIVER

摘要

A high definition color television transmission system in which wide band luminance information (Y, FIG. 1) is divided to produce a first luminance information portion (below 3.8 MHz) and a second luminance information portion (between 3.8 and 8.8 MHz). The first luminance information portion (Y1, FIG. 2) is transmitted by way of a first transmission path together with a color subcarrier (fsc) modulated by color information. The bandwidth of the color information is such that the modulation components lie outside the bandwidth of the first luminance information portion. The second and higher frequency luminance information portion is frequency shifted to lie within 0 and 5 MHz (Y2, FIG. 3) and is transmitted by way of a second transmission path. The two transmissions may also carry sound signals (fS1, FIG. 2; fS2, FIG. 3). The two transmissions may be jointly received for the provision of a high definition display but the invention has the distinct advantage that the signal of the first transmission path may be received alone by currently manufactured television receivers for reproduction of a display of a quality which is currently acceptable.