Ricoh Company, Ltd.

Katsuo Murase

Yoshinori Wada

Eiichi Adachi

Hajime Kanda

Yuji Koseki

Hiroshi Hishida

The present facsimile machine comprises a system control unit, including a pair of central processing units (CPU's), and main and auxiliary power supplies. In one embodiment of the present invention, the second (slave) CPU receives power from the auxiliary power supply to constantly monitor the facsimile system. Upon receipt of a predetermined signal, the second CPU causes the main power supply turned on to render the first (master) CPU operative, thereby the second CPU becomes functionally dependent upon the first CPU. In another embodiment of the present invention, various functions of the facsimile machine are shared by the two CPU's. That is, one CPU is directed to control the communication-related functions with the other CPU directed to control the mechanism-related functions.

Facsimile system control apparatus

At the transmitting side, a composite signal is synthesized from a color signal of a higher level and a black-and-white signal of a lower level, the composite binary signal is converted into a three-value signal, and this three-value signal is modulated and transmitted. At the receiving side, the received signal is demodulated and converted into a binary signal, its level is detected, and the color signal and the black-and-white signal are separated.

Color facsimile signal transmission system

A cylindrical scanner scans two lines of a document for each revolution, and has two marks spaced approximately 180.degree. from each other which generate a synchronizing signal for each scanline. In order to allow for production inaccuracies in the relative placement of the two marks, means are provided for shifting the scanning signals for each alternate scanline by an amount which corresponds to the error in the relative positions of the two synchronizing signal marks. Thus, the resulting scanlines are in proper phase relationship with each other.

Chronic interline phase error from an image scanner generating plural

A document for transmission has ruled lines such as borders printed at predetermined locations thereon which do not constitute usable information. The main scan direction is perpendicular to the ruled lines. Each main scan line is pre-scanned to determine if the line contains information other than the ruled lines, and the main scan line is scanned again for transmission if information is encountered and skipped if information is not encountered. A gating signal is generated in synchronism with the pre-scanning step, but the gating signal is suppressed while the portions of the main scan line intersecting the ruled lines are being pre-scanned. If the gating signal and electrical signals resulting from pre-scanning usable information contained in the main scan line are sensed simultaneously, the line is scanned for transmission.

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Hino, Japan

Katsuo Murase