US 7,524,011 B2
Temperature detection method and printing apparatus using the same
Norihiro Kawatoko, Kanagawa (Japan)
Assigned to Canon Kabushiki Kaisha, Tokyo (Japan)
Filed on Apr. 12, 2006, as Appl. No. 11/402,020.
Application 11/402020 is a division of application No. 10/764544, filed on Jan. 27, 2004, granted, now 7,048,351.
Claims priority of application No. 2003-024322 (JP), filed on Jan. 31, 2003.
Prior Publication US 2006/0187255 A1, Aug. 24, 2006
Int. Cl. B41J 29/38 (2006.01)
U.S. Cl. 347—17  [347/14; 347/19] 6 Claims
OG exemplary drawing
 
1. A temperature detection method of a printing apparatus which prints by using a printhead, comprising:
a storage step of storing, in a nonvolatile memory, a previous printing time when the printhead has performed a printing operation;
a time acquisition step of acquiring a current time by using a timer which always performs a time counting operation by power supply from an auxiliary power supply capable of supplying power independently of a main power supply that supplies power for performing the printing operation by the printing apparatus;
a calculation step of calculating a time elapsed after the previous printing time on the basis of the current time and the previous printing time;
a comparison step of comparing the elapsed time and a predetermined time;
a measurement step of measuring an environmental temperature by using a sensor arranged in the printing apparatus in accordance with the comparison result in said comparison step;
a detection step of detecting a head temperature using a temperature detection device provided in the printhead, wherein a fluctuation of the detected temperature by the temperature detection device is greater than that by the sensor arranged in the printing apparatus;
an update step of updating a head temperature correction value on the basis of a difference between the environmental temperature measured in said measurement step and the head temperature detected in said detection step in a case where said comparison step determines that the elapsed time exceeds the predetermined time; and
a correction step of correcting the detected head temperature with the updated head temperature correction value in the printing operation.