Patent attributes
A motorized window shade includes a covering structure arranged between a fixed and a movable rail, an electric motor operable to drive displacement of the movable rail relative to the fixed rail, a control interface operable to control operation of the electric motor, and a motor controller respectively connected with the electric motor and the control interface. The control interface includes a first, a second and a third button, the first and second buttons being respectively operable to cause displacement of the movable rail in two opposite directions. The motor controller can record a current position of the movable rail as a limit position of the movable rail in response to a pressure concurrently applied on the third button and one of the first and second buttons. In some embodiments, methods of operating the motorized window shade are also described.