Abstract: Scanning and recording operations are performed by separate mechanical and electronic units. Signal processing, run length encoding and decoding operations are performed by a microcomputer on a priority interrupt basis utilizing at least two sections of a random access memory. The microcomputer operates on and stores the data on a byte-by-byte basis, with each byte having a predetermined number of bits such as eight.

Abstract: A scanner scans an original document in two orthogonal directions and produces binary data signals representing the document. An extractor combines each two scan lines into one scan line by taking the logical sum of the data signals in corresponding positions in the two original scan lines. Each second data signal is removed. The data signals in even positions in one line are removed and the data signals in odd positions in the succeeding line are removed, thereby removing the data signals in a zig-zag manner. The data signals so processed are subjected to run-length encoding. In a receiver, the data signals are run-length decoded and fed into an interpolator which senses the data signals and inserts data signals into the spaces from which data signals were removed in accordance with a predetermined logical function. The interpolator controls a printer to print each scan lines twice to reproduce the original document.

Abstract: Main scan pulses are applied to a CCD charge accumulation type linear photosensor array to effect horizontal scan of a linear portion of a light image of an original document focussed on the array. The document is moved by one increment each time the array is scanned to effect vertical scan. Scanning is performed intermittently under control of a run length encoder. The main scan pulses are delayed while the document is moved by one increment when the encoder causes scanning to begin.

Abstract: In a data transmission system comprising, for example, a facsimile transmitter connected to a facsimile receiver through a public telephone network, failure or malfunction sensors are provided at the transmitter and receiver which generate failure signals having the same frequency as the telephone network busy signal upon detection of a malfunction. Both the transmitter and receiver reset at high speed to an initial ready-for-transmission status upon reception of a failure signal from either sensor and automatically disconnect from the telephone network. The failure sensor at the receiver preferably comprises means for generating a failure signal when the failure rate of parity or other digital checks exceeds a predetermined value.

Abstract: A method and device for compressing run-length codes by inserting discrimination bits which discriminate the run-length codes of black elementary areas from those of white elementary areas, where said discrimination bits are weighted as in the case of the bits of the run-length codes.

Abstract: Two facsimile devices, each capable of operating in a plurality of communication modes and having at least one common communication mode are connected together by a telephone line. One of the devices sends to the other a plurality of low and high group frequency signals arranged in a code designating the possible communication modes of the device. The other device receives the signals, determines from them a common communication mode based on its own possible communication modes in accordance with a priority arrangement, and sends high and low group frequency signals to the first device indicating the selected common communication mode so that both of the facsimile devices are set to the selected common communication mode prior to the transmission of graphic information.

Abstract: A facsimile system capable of automatically transmitting or receiving the image through a telephone channel is disclosed in which each facsimile set may automatically reset its facsimile recorder and reader when the intercommunication with the other subscriber's facsimile set is interrupted by an accident during the transmission and reception mode. The facsimile set includes means for disconnecting it from the telephone circuit and means for giving an operator suitable alarm or warning signals so that the transmission or reception may be started again from the beginning.