Masayoshi Hirashima

Teletext Receiver a Circuit Design of the Sampling Clock Regeneration

In recent years Television multiplex broadcasting systems have been put into practical use or have been under investigations in different parts of the world. The development of one kind of Teletext receiver with the means of generating a hard copy began in early 1969 at Matsushita Electric Industrial Co., Ltd. (MEI).(1) In mid 1971, we started to examine a kind of receiver which could receive both Teletext signals and the Data sent on telephone lines.(2) MEI developed the original system of Japanese Teletext under the guidance of the Japan Broadcasting Corporation (NHK). We also developed the receiver and the test signal generator of UK Teletext in the middle of 1977.(3) The main body of this paper considers the method of the sampling clock regeneration of the Teletext receiver. We studied mainly the Japanese Teletext system which is now under consideration by the Radio Wave Technical Council, but most of the results can be applied to UK Teletext and others like it.