Power window apparatus with pinch detecting function

A power window apparatus with a pinch detecting function comprising:

• a motor that opens and closes a window through a window driving mechanism;
• a pulse generator that outputs pulse signals corresponding to a rotation of the motor;
• a switch device that outputs switch signals to manually open and close the window;
• and
• a control unit that generates control signals for controlling the motor according to the pulse signals and the switch signals,
• wherein, when the window is operated to be closed by the switch device, the control unit determines whether a pinching occurs in the window, and when it is determined that the pinching occurs in the window, the control unit performs a process required for avoiding the pinching,
• the control unit does not determine whether the pinching occurs in the window in a start cancellation period from the time when the motor is started to the time when the number of revolutions of the motor reaches a stable point,
• the control unit computes a motor output ratio from the start time of the motor to determine whether a backlash over a predetermined value exists in a driving system including the window driving mechanism and the motor by comparing the computed output ratio with a predetermined threshold value of the output ratio obtained in advance, and detects the number of revolutions of the motor,
• when it is determined that the computed output ratio of the motor is higher than the predetermined threshold value of the output ratio, the control unit determines that the backlash over the predetermined value exists in the driving system, and sets a termination time of the start cancellation period on the basis of the time when the peak of the number of revolutions of the motor is detected, and
• when it is determined that the backlash over the predetermined value does not exist in the driving system, the time when the rate of change of the number of revolutions of the motor reaches a predetermined value or the time when the rate of change of a motor input ratio reaches a predetermined value is set to the termination time of the start cancellation period.