US Patent 7246957 Serial printer with print-medium detecting function

A print head and a detector are mounted on a carriage of a serial printer. An information acquiring portion acquires information for determining whether to detect a print medium. An existence-detection determining portion determines whether to detect existence of the print medium based on the information acquired by the information acquiring portion. An existence-detection controlling portion controls, when the existence-detection determining portion determines that detection should be performed, the carriage to move to a position at which the detector confronts a print-medium conveying path and controls the detector to detect the existence of the print medium prior to printing. A print controlling portion controls the print head and the carriage to print the image based on the print data. The print controlling portion prohibits the print head and the carriage from printing the image based on the print data when the detector detects no print medium.