PRINTER

PROBLEM TO BE SOLVED: To prevent a high accuracy optical linear encoder suitable for high resolution printer from being contaminated with print mist without having any effect on the hitting accuracy of ink. SOLUTION: The printer comprises a mechanism for moving a carriage 1 mounting a print head 2 on a line for the purpose of scanning, a linear encoder scale 3 stretched in the scanning direction of the carriage, and a linear encoder head 4 for detecting the position of the carriage 1 in conjunction with the linear encoder scale 3. The printer further comprises, as means for preventing contamination of an encoder sensor, a body chassis 7 serving as a section for directing air from an air supply means to the moving region of the carriage 1 and the linear encoder scale 3, and a ventilating section formed on the carriage 1 integrally therewith and provided with a hole 1a having an inclining face 1b for introducing air to the linear encoder head 4 while increasing the current velocity.