Brushless motor and wiper apparatus

A brushless motor comprising:

• a motor unit having a rotating element;
• a speed-reducing mechanism which reduces rotating speed of the rotating element;
• an output shaft which outputs a torque of the speed-reducing mechanism to outside thereof;
• a board having a first surface facing the rotating element and the output shaft and a second surface opposite to the first surface;
• a control unit mounted on the board, the control unit controlling rotation of the rotating element;
• a first magnet disposed on radial exterior of the rotating element and having a plurality of magnetic poles arranged along a rotation direction of the rotating element;
• a second magnet disposed on one end side of the output shaft in its axial direction and having a plurality of magnetic poles arranged along a rotation direction of the output shaft;
• first and second sensors which are mounted on the first surface, the first and second sensors facing the first magnet and arranged at a given interval along the rotation direction of the rotating element;
• a third sensor mounted on the second surface, the third sensor facing the first magnet and disposed between the first sensor and the second sensor;
• and
• a fourth sensor mounted on the first surface and facing the second magnet.

A wiper apparatus comprising a brushless motor which causes a wiper to swing, wherein

• the brushless motor includes:
• a motor unit having a rotating element;
• a speed-reducing mechanism which reduces rotating speed of the rotating element;
• an output shaft which outputs a torque of the speed-reducing mechanism to outside thereof;
• a board having a first surface facing the rotating element and the output shaft and a second surface opposite to the first surface;
• a control unit mounted on the board, the control unit controlling rotation of the rotating element;
• a first magnet disposed on radial exterior of the rotating element and having a plurality of magnetic poles arranged along a rotation direction of the rotating element;
• a second magnet disposed on one end side of the output shaft in its axial direction and having a plurality of magnetic poles arranged along a rotation direction of the output shaft;
• first and second sensors which are mounted on the first surface, the first and second sensors facing the first magnet and arranged at a given interval along the rotation direction of the rotating element;
• a third sensor mounted on the second surface, the third sensor facing the first magnet and disposed between the first sensor and the second sensor;
• and
• a fourth sensor mounted on the first surface and facing the second magnet.