Patent ID: 8589962

Claim:
An apparatus comprising: an opening and closing mechanism equipped with a housing having an opening and closing body disposed therein; a driving force transmission system for propagating a driving force from a driving source disposed in said housing to said opening and closing body via gears to perform an opening or closing operation; a position sensor for detecting a variance in position of said opening and closing body; and a control unit programmed to determine whether a speed change of the opening or closing operation is caused by a foreign object being caught or by a play factor of said driving force transmission system by: during a first predetermined time period commencing at the start of said opening or closing operation and during a second predetermined time period in the vicinity of an end point of said opening or closing operation, determining that a foreign object is caught when said position sensor has not detected a variance in said position of said opening and closing body during making a foreign object detection time period which is longer than a play detection time period, said play detection time period being a time period during which an absence of detection of a variance in said position of said opening and closing body is attributed to the play factor of said driving force transmission system, and after the first predetermined time period has expired but before the second predetermined time period has commenced, determining that a foreign object is caught when said position sensor has not detected a variance in said position of said opening and closing body during a foreign object detection time period which is shorter than said play detection time period.