A LAMP SHUTTER POSITIONING SERVICE SYSTEM
Original Publication Date: 1981-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
As shown in the drawing, a servo positioning device is used to locate a lamp shutter 10. The system uses a DC motor 12 to drive a lead screw 14 having shutter 10 mounted thereon. The lead screw has a two-lobe cam attached thereto which actuates microswitch 18 to provide a counting system to position shutter 10. Lead screw 14 has right and left hand threads impressed over one another and interconnecting at both ends to drive shutter 10 from one end of the screw to the other end and then to return it to its initial position by using a unidirectional motor. Activating finger 20 is attached to follower block 20 so as to cause counter switch 18 to be interrupted only when the follower passes through the home position. This causes an interrupt in the pulse train transmitted by counter switch 18 which is used by the system controller as a reference from which to begin counting for properly positioning shutter 10.