Wiper device

A wiper device comprising:

• a wiper motor that includes a rotor and a coil to generate a rotating magnetic field, and that causes a wiper blade to perform a wiping operation by rotating the rotor according to the rotating magnetic field;
• a drive section that drives rotation of the wiper motor by performing current switch-on in the coil so as to generate the rotating magnetic field;
• and
• a controller that controls the drive section by a timing for current switch-on in the coil based on at least a rotation position of the rotor, wherein:
• in a case in which a speed command is for a first rotation speed, the controller controls the drive section so as to perform first rotation control in which current switch-on in the coil is performed at a timing corresponding to a rotation position of the rotor;
• the controller controls the drive section so that at least one control is performed of
• second rotation control in a case in which the speed command is for a second rotation speed that is faster than the first rotation speed, in which current switch-on in the coil is performed at an effective voltage that is higher than a voltage in the first rotation control and at a timing advanced in electrical angle with respect to the timing of the first rotation control, and
• third rotation control in a case in which the speed command is for a third rotation speed that is slower than the first rotation speed, in which current switch-on in the coil is performed at an effective voltage that is lower than the voltage in the first rotation control and at a timing lagging in electrical angle with respect to the timing of the first rotation control;
• in a case in which a difference between the second rotation speed indicated by the speed command and a present rotation speed of the wiper motor is large, the controller controls the drive section such that the effective voltage for the current switch-on to the coil is raised and the timing of the current switch-on is advanced such that the rotation speed of the wiper motor attains the rotation speed indicated by the speed command;
• and
• in a case in which a difference between the present rotation speed of the wiper motor and the third rotation speed indicated by the speed command is large, the controller controls the drive section such that the effective voltage for the current switch-on to the coil is lowered and the timing of the current switch-on is retarded such that the rotation speed of the wiper motor attains the rotation speed indicated by the speed command.