Abstract: A book data service system in which the book data can be delivered by the broadcasting such that the book data can be delivered to any user located at any place promptly and economically, without causing the waste of the resources. A book data service system if formed by at least one data center including: a data center computer for storing and managing book data; and a broadcasting facility for broadcasting the book data stored and managed by the data center computer according to a prescribed communication protocol using a synchronization control and an error correction scheme suitable for data delivery by broadcasting without confirmation from a receiving side; and a plurality of user terminals, each user terminal including: a receiver for receiving the book data broadcasted from the broadcasting facility of the data center; a user terminal computer for storing and managing the book data received by the receiver; and a display for displaying the book data stored and managed by the user terminal computer.

Abstract: A book data service system in which the book data can be delivered by the broadcasting such that the book data can be delivered to any user located at any place promptly and economically, without causing the waste of the resources. A book data service system if formed by at least one data center including: a data center computer for storing and managing book data; and a broadcasting facility for broadcasting the book data stored and managed by the data center computer according to a prescribed communication protocol using a synchronization control and an error correction scheme suitable for data delivery by broadcasting without confirmation from a receiving side; and a plurality of user terminals, each user terminal including: a receiver for receiving the book data broadcasted from the broadcasting facility of the data center; a user terminal computer for storing and managing the book data received by the receiver; and a display for displaying the book data stored and managed by the user terminal computer.

Abstract: A facsimile signal superposing system for an analog type modulated facsimile signal has been found. The present superposing system has a digital memory storing the pattern to be superposed, and the insertion circuit which has a first input terminal for receiving the original facsimile pattern, a second input terminal for receiving the output of said digital memory, and an output terminal providing the sum of the first and the second input terminal signals. The cells of the digital memory are read one after another substantially synchronized with the original picture signal, thus, a superposed facsimile signal is obtained at said output terminal. The additional pattern to be superposed is, for instance, the date of the facsimile transmission.