Printing apparatus and method of saving power of the same

A printing apparatus comprising:

• interface means for transmitting and receiving a signal between the apparatus and an external host system;
• an operation panel including signal input means;
• image forming means for forming an image on a recording medium;
• main control means for transmitting and receiving a signal among the interface means, the operation panel and the image forming means and processing the signal in accordance with a predetermined program;
• and
• power supply control means for stopping or limiting a power supply to the image forming means in accordance with a command from the main control means;
• wherein
• when a signal input from an external host system stops for a predetermined length of time, or when a predetermined signal input from the operation panel occurs, the power supply control means is activated and the printing apparatus is transferred into a power saving mode,
• the power saving mode is canceled by a signal input from either the external host system or the operation panel, and
• when the signal input from the operation panel, commanding the power saving mode, occurs during transmission of printing data from the external host system, the printing apparatus is transferred to the power saving mode after the lapse of a predetermined length of time from completion of the data transmission.

A method of saving power of a printing apparatus;

• the printing apparatus including
• interface means for transmitting and receiving a signal between the apparatus and an external host system;
• an operation panel including signal input means;
• image forming means for forming an image on a recording medium;
• main control means for transmitting and receiving a signal among the interface means, the operation panel and the image forming means and processing the signal in accordance with a predetermined program;
• and
• power supply control means for stopping or limiting a power supply to the image forming means in accordance with a command from the main control means;
• said method comprising the step of activating the power supply control means on the basis of a predetermined signal input from the operation panel and thereby transferring the apparatus to a power saving mode.

A method of saving power of a printing apparatus;

• the printing apparatus including
• interface means for transmitting and receiving a signal between the apparatus and an external host system;
• an operation panel including signal input means;
• image forming means for forming an image on a recording medium;
• main control means for transmitting and receiving a signal among the interface means, the operation panel and the image forming means and processing the signal in accordance with a predetermined program;
• and
• power supply control means for stopping or limiting a power supply to the image forming means in accordance with a command from the main control means;
• said method comprising the steps of:
• activating the power supply control means and thereby transferring the printing apparatus into a power saving mode when a signal input from an external host system stops for a predetermined length of time, or when a predetermined signal input from the operation panel occurs;
• canceling the power saving mode by a signal input from either the external host system or the operation panel, and
• when the signal input from the operation panel, commanding the power saving mode, occurs during transmission of printing data from the external host system, transferring the printing apparatus to the power saving mode after the lapse of a predetermined length of time from completion of the data transmission.