| 摘要 |
PURPOSE:To reduce crosstalk to improve the performance, by setting a fundamental clock frequency to an integral multiple of the frequency of the horizontal synchronizing signal in the signal transmission system for time division multiplex transmission of various signals of a TV camera. CONSTITUTION:In case of time division multiplex transmission of signals between a TV head and a control device, horizontal and vertical synchronizing signals, the sound signal, the control signal, etc. other than video signals are encoded collectively by FSK modulation and are transmitted as one channel. For example, signals from the TV camera (CAM) side to the control device (CCU) side are digitized by modulation due to fundamental clocks of 1.06mus obtained by dividing equally one period 63.5mus of the horizontal synchronizing signal HD by 60. Meanwhile, signals in the opposite direction are digitized by modulation due to clocks of 2.12mus twice as long as 1.06mus. Consequently, 7 channels are multiplexed as the whole. Thus, respective signals in directions opposite to each other have upper and lower frequencies different from each other distinctly, and crosstalk is reduced, and the performance is improved. |
