Abstract: A facsimile machine and a self-diagnosis method performed by a facsimile machine are provided. The facsimile machine receives a self-diagnosis execution command, performs self-diagnosis according to the self-diagnosis execution command, and outputs a self-diagnosis result report.

Abstract: A facsimile machine and a self-diagnosis method performed by a facsimile machine are provided. The facsimile machine receives a self-diagnosis execution command, performs self-diagnosis according to the self-diagnosis execution command, and outputs a self-diagnosis result report.

Abstract: A facsimile, a method of controlling the same, and an image forming apparatus having a facsimile function are provided. The facsimile includes a line terminal provided for connection with a line cord and connected with a first signal line, an external device terminal provided for connection with an external device and connected with a second signal line, a switching unit to perform switching between the first signal line and the second signal line, and a controller to determine a connection state between the line terminal and the line cord and a connection state between the external device terminal and the external device, and to, when the external device and the line cord are reversely connected respectively to the line terminal and the external device terminal, control the switching unit to interchange a path of the first signal line and a path of the second signal line.

Abstract: A facsimile machine capable of preventing a communication clock signal from being emitted in the form of electromagnetic waves during communication, for example, transmission/reception of facsimile data includes a line terminal provided for coupling with a line cord and connected with a common line and a first signal line, an external device terminal provided for coupling with an external device and connected with the common line and a second signal line, a switch to perform switching between the first and second signal lines, and a first electromagnetic wave prevention unit provided on the common line and the second signal line to discharge electromagnetic waves generated on the common line and the second signal line.

Abstract: A facsimile, a method of controlling the same, and an image forming apparatus having a facsimile function are provided. The facsimile includes a line terminal provided for connection with a line cord and connected with a first signal line, an external device terminal provided for connection with an external device and connected with a second signal line, a switching unit to perform switching between the first signal line and the second signal line, and a controller to determine a connection state between the line terminal and the line cord and a connection state between the external device terminal and the external device, and to, when the external device and the line cord are reversely connected respectively to the line terminal and the external device terminal, control the switching unit to interchange a path of the first signal line and a path of the second signal line.

Abstract: A line interface unit in which a circuit to detect a calling line and a ring signal includes a connecting unit connected to a public switched telephone network (PSTN) to individually detect the calling line and the ring signal and to commonly use an insulating circuit electrically insulated from PSTN. A circuit to detect the calling line and the ring signal is simply implemented so that economical burden can be reduced.

Abstract: An image forming apparatus and a telephone operation regulating method thereof, the image forming apparatus including a main body that is connectable to an external telephone communication line; a receiver comprising an audio output unit and an audio input unit, connected to the main body; and a sensing unit disposed inside the receiver, to determine whether the receiver is in an on-hook state or an off-hook state.

Abstract: A line interface unit in which a circuit to detect a calling line and a ring signal includes a connecting unit connected to a public switched telephone network (PSTN) to individually detect the calling line and the ring signal and to commonly use an insulating circuit electrically insulated from PSTN. A circuit to detect the calling line and the ring signal is simply implemented so that economical burden can be reduced.

Abstract: A public network interface device includes a first switching unit operating in either an on-hook mode in which a first signal is applied or an off-hook mode in which a second signal is applied, and receiving the first signal and the second signal; a signal conversion unit converting the first signal and the second signal into a first detected signal and a second detected signal, respectively, if the first signal and the second signal are applied in the respective modes; and a second switching unit applying the first signal and the second signal to the signal conversion unit in accordance with the respective modes.

Abstract: A sublimable image forming apparatus and a method of controlling the same are provided. The apparatus comprises a main body having an image forming unit provided therein, and an access opening through which a recoding medium goes in and out during an image forming process, and a display unit disposed at the main body to display an instruction to determine whether a margin of the recording medium is obtained such that the recording medium can go in and out through the access opening in a progress direction of the recording medium.

Abstract: A power switching device usable with an image forming apparatus having telephone functions includes a bridge diode connected to a telephone line, a power supply unit to form a loop with the bridge diode, and to supply a first DC power outside the power switching device, a photo coupler to close/open the loop, and a control unit to control the photo coupler. The power switching device is compact and inexpensive including a photo coupler.

Abstract: A communication interface circuit is connected to a tip terminal and a ring terminal establishing a call connection through a public switched telephone network to provide an interface between a modem and the public switched telephone network. The communication interface circuit includes a first capacitor, a transformer, and a first resistor. The first capacitor is serially connected to the tip terminal. The transformer has a primary coil connected to the first capacitor and a secondary coil connected to the modem. The transformer includes a low impedance to match an impedance between the modem and the public switched telephone network. The first resistor is serially connected to the primary coil of the transformer.