Patent ID: 7131719

Claim:
An inkjet printer comprising: a plurality of inkjet heads which eject ink to form an image on a recording medium, respectively; a plurality of pumps which supply the ink to the inkjet heads; a drive source; a first drive shaft rotated forward or backward by the drive source; a plurality of first power transmission mechanisms which are disposed between the first drive shaft and the pumps, respectively and switch between a state where a forward rotation force of the first drive shaft is transmitted to each pump to bring each pump in a operable condition and a state where the forward rotation force of the first drive shaft is not transmitted to each pump; and a selection unit which, in conjunction with a backward rotation of the first drive shaft, selects at least one of the first power transmission mechanisms to be brought into a state where the selected first power transmission mechanism transmits the forward rotation force of the first drive shaft; a second drive shaft which rotates in a reverse direction of the rotation of the first drive shaft in conjunction with the rotation of the first drive shaft, wherein: each of first power transmission mechanisms includes: a sun gear which rotates together with the rotation of the first drive shaft; a planet gear which revolves around the sun gear while engaging with the sun gear; and a holding member which holds the plane gear between a operation position where the planet gear engages with a gear, which rotates together with a rotation shaft of the corresponding pump to transmit the forward rotation force of the first drive shaft to the corresponding pump, and a retraction position where the planet gear retracts from the operation position; the selection unit includes a plurality of cams for each first power transmission mechanism, the cams disposed on the second drive shaft; each of holding members of the first power transmission mechanisms abuts against each of cams; and when a rotation position of the second drive shaft is in predetermined angle ranges, which are assigned to the first power transmission mechanisms, respectively, each of cams moves each of holding members of the first power transmission mechanisms from the retraction position to the operation position.