| 摘要 |
<P>PROBLEM TO BE SOLVED: To make a position detecting sensor magnet of a wiper arm thin, and to reduce the cost, size and weight of a motor. <P>SOLUTION: In an electric motor equipped with a reduction mechanism that is used as a drive source of a wiper unit, an operational magnetized region 51 and a corrective magnetized region 52 are arranged at the position detecting sensor magnet 41 of the wiper arm. The operational magnetized region 51 is provided with a brake region 53 and a drive region 54. The magnetizing angle of the drive region 54 is larger than that of the brake region 53. The magnetized region 52 is provided with a corrective N pole 56 and a corrective S pole 55. The N pole 56 is formed to be heteropolar with respect to the drive region 54, and the S pole 55 is formed to be heteropolar with respect to the brake region 53. The N pole 56 and the S pole 55 are set to values of the same angles or values obtained by dividing the magnetized region 52 at the ratio of the magnetizing angles of the drive region 54 and the brake region 53. Due to the existence of the N pole 56, a decrease in the magnetic flux density of the drive region 54 having a larger magnetizing angle is suppressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
