Browse Prior Art Database

Original Publication Date: 1994-Aug-31
Included in the Prior Art Database: 2004-Apr-07

Publishing Venue

Xerox Disclosure Journal


Proposed is a failure sensor scanning mechanism for a printing machine. The proposed mechanism shown in the Figure consists of double pitch lead screw 4, sensor carriage 6 and position bar code 8. Failure sensor 10 and position sensor 12 are mounted to sensor carriage 6 which is driven back and forth across the width of photoreceptor 14 by double pitch (or double helix) lead screw 4 rotated in one direction by a drive (not shown). The sensors 10 and 12 are electrically connected to a control system in the printing machine by a flexible ribbon cable (not shown). The position sensor 12 and position bar code 8 allow the control system to determine the location of cleaning failure defects detected by failure sensor 10. The position bar code 8 consists of white and black position blocks which are detected by the position sensor 12 and correspond to cleaning failure inspection zones on the photoreceptor 14. Starting from one end, each of the position blocks is assigned an address by the control system. The ends of the position bar code 8 consist of highly reflective blocks 16 and 17 (e.g., aluminum foil) which are sensed by the position sensor 12. Detection of reflective blocks 16 or 17 by position sensor 12 is transmitted to the control system by position sensor 12 to indicate that one end of photoreceptor 14 has been reached. Also, the control system reverses the order of the position block addresses to determine photoreceptor failure zones once position sensor 12 has detected a reflective block.