Patent ID: 6991312

Claim:
A print head maintenance mechanism for use in an ink jet printing machine in which printing is carried out by driving a carriage carrying a print head, the maintenance mechanism comprising: a cap for preventing a nozzle provided at the print head from drying; a cap holder retaining the cap and allowed to move along directions orthogonal to a primary scanning direction and a secondary scanning direction of the print head; a first cam which is rotated at a predetermined position; first biasing means for biasing a bottom portion of the cap holder against the first cam; a wiper for cleaning by wiping a surface of the nozzle provided at the print head; a second cam which is rotated at a predetermined position; a wiper holder retaining the wiper and allowed to move along directions orthogonal to the primary scanning direction and the secondary scanning direction of the print head; and second biasing means for biasing a bottom portion of the wiper holder against the second cam, wherein the first and second cams are mounted to a single cam shaft, and wherein the cam shaft is rotated through one revolution for switching the cap holder and wiper holder between a printing mode position for permitting a normal printing operation, a capping mode position for sealing the surface of the nozzle at the print head with the cap, and a wiping mode position for cleaning by wiping the nozzle surface with the wiper.