| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem for an image processing apparatus that a main control unit cannot control a recording unit, because print data cannot be transmitted if any abnormality occurs at the recording unit, or because the printing status cannot be received from the recording unit if communications between the recording unit and the main control unit are disconnected, when the main control unit is connected to the recording unit via a unidirectional parallel communication for print data transmission and a bidirectional serial interface for receiving the printing status from the recording unit. <P>SOLUTION: Print data is transmitted from the main control unit to the recording unit using a USB (Universal Serial Bus) as a bidirectional serial interface between the main control unit and the recording unit, and the data is transferred by transmitting the printing status from the recording unit to the main control unit. In addition, a multiple connection of status signal lines is provided between the main control unit and the recording unit. When communications cannot be done by the bidirectional interface, the main control unit monitors these status signal lines and outputs a power signal to the recording unit to enable its recovery. <P>COPYRIGHT: (C)2004,JPO |
