Patent ID: 6869241

Claim:
A printer comprising: a paper transport unit that transports paper fed thereto; a print unit that prints on the paper, including a print head; a downstream sensor mounted on the print head and capable of detecting the paper; an upstream sensor disposed upstream of the downstream sensor in a paper-transport-direction and capable of detecting the paper; a first measuring unit configured to make the paper transport unit transport the paper at a first speed of low speed while making the upstream sensor detect a rear end of the paper, and to make the paper transport unit transport the paper till the downstream sensor detects the rear end of the paper, so as to obtain a first transport distance with which the paper has been transported since being detected by the upstream sensor and till being detected by the downstream sensor; a second measuring unit configured to make the paper transport unit transport the paper at a second speed of high speed while making the upstream sensor detect the rear end of the paper, and to make the paper transport unit transport the paper till the downstream sensor detects the rear end of the paper, so as to obtain a second transport distance with which the paper has been transported since being detected by the upstream sensor and till being detected by the downstream sensor; a response delay calculating unit configured to calculate a response delay time of the upstream sensor according to a difference between the first transport distance and the second transport distance; and a correction unit configured to correct a remaining printable distance on a paper rear end side after detecting the rear end of the paper by the upstream sensor, on the basis of the response delay time.