Printer

A printer connected to a host device, the printer having a sleep mode in which power and clock signals used by parts of the printer during normal printing operations are halted, the printer comprising:

• a processor that receives a clock signal;
• a printing part that prints on the basis of print data from the host device;
• a control part that (1) operates by a clock input and controls the printing part, (2) determines when the printer should enter into the sleep mode, and (3) when the printer is in the sleep mode, halts the output of the clock signal to the processor;
• a storage part that stores reception data received from the host device;
• a judgment part that, when the printer is in the sleep mode, judges whether the reception data from the host device is necessary data for printing and erases the reception data stored in the storage part without releasing the sleep mode when the reception data is judged by the judgment part to be unnecessary data for printing;
• and
• a power saving control part that, when the reception data is necessary data for printing, receives the reception data and releases the sleep mode.

A printer connected to a host device, the printer having a sleep mode in which power and clock signals used by parts of the printer during normal printing operations are halted, the printer comprising:

• a power source;
• a processor that receives power from the power source;
• a printing part that prints on the basis of print data from the host device;
• a control part that (1) operates by a clock input and controls the printing part, (2) determines when the printer should enter into the sleep mode, and (3) when the printer is in the sleep mode, halts the supply of power to the processor;
• a storage part that stores reception data received from the host device;
• a judgment part that, when the printer is in the sleep mode, judges whether the reception data from the host device is necessary data for printing and erases the reception data stored in the storage part without releasing the sleep mode when the reception data is judged by the judgment part to be unnecessary data for printing;
• and
• a power saving control part that, when the reception data is necessary data for printing, receives the reception data and releases the sleep mode.