| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of high-pitched rasping noises when driving a pump that produces air pressure to deliver ink in a main tank to a sub-tank in an ink-jet recording device. SOLUTION: The arrival of a piston mechanism 3 at a reference position is recognized by output from a limit switch 5. The time when the piston mechanism 3 is in the reference position in the rotation cycle of a motor 9 last time is subtracted from the time when the rotational driving of the motor 9 is started this time, to obtain the time T<SB>n</SB>of the rotation cycle of the motor 9 immediately before (S31). A driving time (t) from the start time of rotational driving of the motor 9 is measured in predetermined time units in the reference position of the piston mechanism 3 (S32). The moving distance of the piston mechanism 3 corresponding to the rotation cycle of the motor 9 is multiplied by a rate t/T<SB>n</SB>of the driving time (t) obtained in S32 to the time T<SB>n</SB>of the rotation cycle of the motor 9 immediately before, to predict a distance from the reference position of the piston mechanism 3 as a present position X of the piston mechanism 3 (S33). COPYRIGHT: (C)2011,JPO&INPIT |
