Patent ID: 7916316

Claim:
A printer comprising: a data receiving unit for receiving data sent from a host computer; a data transmission unit for sending data to said host computer; a receive buffer for temporarily storing data received by said data receiving unit; an interpreting unit for interpreting data stored in said receive buffer; a print buffer for storing a print image generated in response to print data among said data stored in said receive buffer; a print mechanism for printing said print image stored in said print buffer; a detecting unit for detecting an out-of-paper error; and a control unit for controlling said data receiving unit, said data transmission unit, said receive buffer, said interpreting unit, said print buffer, and said print mechanism; wherein said control unit is adapted, in response to the out-of-paper error detected by the detecting unit, to stop printing, to clear said data in said receive buffer, to send said out-of-paper error and a printing stop report to said host computer while keeping the printer on-line; wherein said control unit is further adapted to clear said receive buffer again in response to a clear buffer command which is sent from the host computer in response to the out-of-paper error, to send a buffer clearing completion report to said host computer after receiving said clear buffer command, and to print based on print data received from said host computer after said buffer clearing completion report is sent.