Patent ID: 7524011

Claim:
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.