Wiper device
AssigneeDenso Corporation
InventorYuta Doi
Life of this patent
Estimating the term…
Abstract
A wiper motor control circuit carries out control in which a driving circuit generates, and supplies to a wiper motor, a voltage that eliminates deviation between a target speed and an actual speed of an output shaft. In a case in which a state in which the deviation between the target speed and the actual speed is greater than or equal to a predetermined threshold value continues for a predetermined time or more, the wiper motor control circuit carries out control that lowers the target speed and in which the driving circuit generates, and supplies to the wiper motor, a voltage that eliminates deviation between the lowered target speed and the actual speed of the output shaft.
Claims9
A wiper device comprising:
- a wiper motor that causes wiper blades to carry out wiping operation;
- a driving circuit that generates voltage that is supplied to the wiper motor;
- and
- a microcomputer comprising a processor configured to operate as:
- a speed detecting section that detects a rotational speed of the wiper motor;
- a judging section that calculates a deviation between a predetermined target rotational speed expressed by a speed command value and an actual rotational speed of an output shaft of the wiper motor detected by the speed detecting section, compares the calculated deviation to a predetermined value multiple points in time within a wiping operation period, and judges whether the wiper motor is in an overload state by determining whether the deviation at multiple points in time within the wiping operation period continues to exceed a predetermined value for a predetermined time or more, the predetermined time being a time shorter than the wiping operation period;
- and
- a control section that, when the judging judges that the deviation exceeds the predetermined value for the predetermined time or more, controls the driving circuit such that voltage for deceleration that is lower than a voltage for driving is supplied to the wiper motor.
Dependencies are inferred from the claim text.