Television standards convertors using a line store

The paper describes the fundamental principles of design of a new type of standards convertor which has been developed specifically for conversions between the 625-line and 405-line television standards. The need for a new type of standards convertor and the basic principles of a line-store convertor are first discussed. A complete account of the new convertor is then given under four main divisions. First, the fundamental aspects of standards conversion are discussed in terms of time functions and spectra, and then the specifications of the various functions of the new convertor are derived by analytical and empirical means. The last two sections discuss aspects of the instrumentation which are either novel or of particular interest, and, finally, the design of two fundamentally similar but instrumentally different line-store convertors. An indication of the performance which has been obtained and the present and future operational use of these devices are discussed.