Digital Triaxial Transmission Provides Total Digital Studio Camera System

Hitachi has developed a fully digital broadcast camera system in which all signal processing and transmission are accomplished in the digital domain. Digital transmission utilizes a newly developed time-division multiplex method that allows bi-directional serial digital transmission between the camera head and camera control unit over standard triaxial cable. All video and audio signals between the camera head and the camera control unit (CCU) are combined into a single 360Mbps serial digital signal for transmission. To provide the highest quality main video with the limited data capability of the triaxial cable, motion JPEG is used to compress the return video channel to 1/7 of its original size. 10-bit data accuracy is used for the Y, R-Y and B-Y signals transmitted from the camera head to the CCU. The Y channel data rate is the same as the CCD readout clock and the R-Y and B-Y data signals are clocked at half this rate. At the CCU, the digital video signals are digitally rate converted directly into either a composite serial digital signal (D2 type) or component serial digital (D1 type) signal for direct interface with digital studio equipment. With the fully digital camera, a true 62dB S/N ratio is available at the CCU output as well as 800 TV lines of high resolution.

Published

1995-09

Content type

Original Research

DOI

10.5594/M00476

ISBN

978-1-61482-923-2