In an opposed wiping type wiper apparatus, left and right wiper blades which perform wiping operation with a predetermined preceding-following relationship maintained are layered vertically at their lower returning positions. If the predetermined preceding-following relationship is changed, the speed of the wiper blade which has overtaken is arranged to be higher than the wiper blade which has been overtaken, by replacing the control forms for the left and right wiper blades with each other, until upper returning positions. In this manner, the wiper blades are prevented from being locked and stopped when the preceding-following relationship between the left and right wiper blades is changed.
When the timer of the wiper blade which is to be in the follower side during normal operation is not reset but overflows among timers which are respectively reset pulse signals generated in accordance with rotations of motors, the output of the motor which drives the wiper blade which is to be in the follower side during normal operation is increased. If the wiper blade which is to be in the preceding side during normal operation is operated by thus increasing the motor output, it is determined that the apparatus has stopped due to change of the preceding-following relationship between the wiper blades, and the wiper blades are operated by changing the preceding-following relationship. In this manner, the wiper blades are prevented from being locked even in case where the preceding-following relationship between the wiper blades is changed without causing changes of position angles.
If the wiper blade 2a in the preceding side stops for a predetermined time or more within a common region 9 set as the range where wiping regions of both the wiper blades 2a and 2b overlap each other during driving of the wiper blade 2a in the preceding side, the wiper blade 2b in the follower side is operated so as to push up the wiper blade 2a in the preceding side, so that a load applied to the wiper blades is effectively overcome with use of the outputs from two motors.