Patent attributes
When a wiper is started, a wiper arm is moved at first in the backward path direction (S1). If a motor is locked (S2) before an original point position signal is outputted, a reciprocating operation for moving the wiper arm temporarily in the forward path direction and then moving the wiper arm again in the backward path direction is performed (S5-S8, S1). When an absolute position signal is not outputted even after repeating the reciprocating operation a plurality of times (S5) and the original point position cannot be recognized (S2, S5), the motor is not forced furthermore but stopped (S5→END) On the other hand, if the motor is not locked when the wiper arm is moved in the backward path direction (S1) and the original point position can be recognized (S2, S3), wiping control is performed (S4) by calculating the wiper arm position based on the original point position and the motor rotation pulse.
