Canon Kabushiki Kaisha

Naoto Kagami

Yukio Murata

Yukihiko Ogata

Hidetoshi Tanno

Takashi Kotani

A communication apparatus which is connected to an ISDN includes a data input/output (I/O) unit for inputting/outputting data and an ISDN interface to control the data input/output operations between the data I/O unit and the ISDN. The ISDN interface is constructed on a one-chip IC and at least includes an interface for separating B-channel data and D-channel data and for inputting/outputting the data, a switch for switching data paths in accordance with the classification of the information of the B-channel data and a modem which is connected to the path for 3.1K audio in the path of the B-channel data. The ISDN interface further has a speed matching processing circuit for matching the speed of the data which is inputted/outputted to/from the data I/O unit with the speed of 64k non-limit digital data. A commercial power source is supervised and the occurrence of a power failure is detected by a detecting unit. In case of a power failure, a power supply mode is switched from a commercial power source to a power supply from the line and the power source is supplied to the ISDN I/F unit and the one-chip microcomputer.

Communication apparatus

A communicating apparatus having a plurality of ports to connect a plurality of communication lines comprises a memory to store information indicating whether the plurality of communication lines are extensions of a private branch network or not, a designating circuit to designate whether the communication is to be executed through said extensions or not, and a selector to select one of the plurality of ports in accordance with the result of the designation of the designating circuit and the contents of the memory. The memory stores information indicating whether the communication lines are ISDN lines or PSTN lines. The selector includes a call generating circuit for generating a call in the G4 facsimile mode when the selected communication line is an ISDN line and for generating a call in the G3 facsimile mode when it is decided that the partner is not a G4 facsimile apparatus after completion of the call generation.

Communication apparatus which can connect a plurality of communication

An image transmission device is capable of transmitting image data in different resolutions with different pixel number of the image. The gamma correction values are converted in proportion to the transmittal resolution of the image data and the quasi half-tone which closely follows the original image is reproduced with less degree of omission of minute lines.

Image transmission device

A data communication apparatus includes an analog communication unit for performing analog communication, an A/D converter for converting the analog signal from the analog communication unit into a digital voice signal, and an ISDN communication control unit for sending the digital voice signal from the A/D converter onto a digital communication line. Data used in an ISDN are voice data, image data, facsimile communication data, etc.

Data communication apparatus which can use either an analog or a digital

A line interface for ISDN channels converts an analog signed from an analog communication terminal to digital data and sends the converted digital data to a B-channel of ISDN. The digital data from the B-channel of ISDN is converted to an analog signal and the converted analog signal is then sent to the analog communication terminal.

Interface for ISDN channels

In a communication apparatus connected to an ISDN and having a telephone function, the arrangement is such that when a call is received from another party's facsimile machine, the number of the sending party received is stored in memory. When depression of a communication start switch by the operator is detected during communication by facsimile, a call is made by telephone based on the stored sending party's number. When a call is made to the other party's fdacsimile machine, the other party's dial number is stored. If it is detected that the operator has taken a handset off the hook during communication by facsimile, a call is made by telephone based on the other party's dial number that has been stored.

Communication apparatus connected to ISDN

A facsimile apparatus connected on an ISDN side in a communication network in which the ISDN is connected to a telephone network includes network identifying means for identifying whether an incoming data sending party is an ISDN terminal or a telephone network terminal, CNG signal detecting means for detecting a CNG signal received via a B channel, and changeover means for changing over between automatic reception and manual reception. In a case where the CNG signal is detected, a response is made in a facsimile mode. In a case where the CNG signal is not detected, a response is made in a facsimile mode if automatic reception prevails and in a telephone mode if manual reception prevails. This arrangement eliminates communication failure due to a difference in mode between a calling side and a called side regardless of the network terminal from which a call is received.

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Yokohama, Japan

Naoto Kagami