摘要 |
A printing apparatus comprises a CPU (1), an image formation part (9), an interface (7) for communicating with an external host apparatus (19), an operation panel (8) which includes an operation switch and the like, etc., and a power cutoff circuit (12) which operates in response to an instruction which is expressed by a power save signal (17). The printing apparatus also comprises a voltage monitoring circuit (15) for monitoring a signal level change of a host side signal, such as a strobe signal, which is supplied from the external host apparatus (19). When the voltage level of the host signal is intermediate between a first reference voltage V1 and a second reference voltage V2, the voltage monitoring circuit (15) judges that power supply to the external host apparatus (19) is cut off. <IMAGE> |