GB1331879A - Data exchange systems - Google Patents

Abstract

1331879 Automatic exchange systems SIEMENS AG 5 Aug 1971 [12 Aug 1970 5 Nov 1970] 36756/71 Heading H4K [Also in Division G4] In a videophone system in which subscribers are connectible to a computer for data processing purposes, each substation incorporates a mounting for receiving a data carrier, e.g. a punched card, which is scannable by the camera of the videophone and means are provided for permitting a representation of transmitted data to be shown on the videophone display tube. The mounting and/or the data carrier are provided with indicia for marking the beginning and end of the useful (in respect of data that is) scanning area of the camera. The indicia may consist of black bars which define the long sides of an 80 column punched card when this is scanned column by column (Fig. 1, not shown); of three completely punched columns of the card, e.g. along its two short sides and a column midway therebetween when it is scanned row-by-row; or, of a completely punched column and row, e.g. along its top and left hand edges also when it is scanned row-by-row (Figs. 3 and 4, not shown). In other arrangements the data carrier may comprise a lamp panel which could consist of the illuminable keys of a data key sender or of n lamps that are selectively illuminated m at a time. In the latter arrangements, the carrier is preferably blanked-off during a change of data (Figs. 5 and 6, not shown). System.-The carrier LK is scanned by camera AK and the resultant video signal transmitted to a synch detector AT of a unit LKZ that may be provided individually for each subscriber A or in common for a plurality of data transmitting subscribers. The detector starts a scanning pulse generator TG in response to the detection of signals representative of the indicia so that useful data may be inserted in magnetic core stores SP of an image converter BU. Prior to storage, checks are made that the data is error free, e.g. by means of a last look process which determines the persistance of data from scanning line to scanning line, and in addition it is recorded from its original 12 bit coding (in the case of a punched card) into an 8 bit code. After the data in store has been further checked, e.g. by comparising it with the result of a second scanning of the carrier LK by camera AK, 't is transmitted on to the picture tube B of the videophone in the form of an alphanumeric display. If the subscriber is satisfied with the authenticity of the data he then causes it to be sent to the computer DVA by actuating a key that causes store SP to be read out. Incoming data from the computer is also passed through the image converter BU so that it may be displayed.