Patent ID: 8692498
Filing Date: 2014-04-08
Classification: E06B,Y02A,Y02B

Abstract:
1. A roller shade system, the system comprising: a flexible shade material having a lower end; a rotatably supported roller tube windingly receiving the flexible shade material; a stepper motor operably engaging the roller tube to rotate the roller tube to move the lower end of the flexible shade material between a first position and a second position; an optical sensor configured for capturing an image frame of the flexible shade material at a plurality of linear positions along the flexible shade material as the lower end of the flexible shade material moves from the first position to the second position; and a stepper motor controller configured for controlling the stepper motor by controlling the frequency of input pulses to the stepper motor to move the lower end of the flexible shade material from the first position to the second position at a substantially constant linear velocity.