| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device for detecting the connection of external equipment realizing reduction in the number of terminals and the number of connectors, and an image forming apparatus, including the same. <P>SOLUTION: The connector 4 of an equipment body 1 and the connector 13 of external expansion equipment 10 can be connected to each other; a capacitor C is connected between an input/output terminal 3, connected to one terminal of the connector 4 of the equipment body 1 and ground; the capacitor C is charged under control by a control circuit 2; the charge of the capacitor C is discharged by a resistance R connected to one terminal of the connector 13 of the external extension equipment 10; and the potential of the input/output terminal 3 of the equipment body 1 is discriminated after predetermined time elapses, so that it is discriminated whether the external equipment have been connected. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
