Patent ID: 6909516
Filing Date: 2005-06-21
Classification: G01D,G01P,G03G,H04N

Abstract:
1. A method of accurately sensing the position of a moving surface having a primary movement direction, wherein said moving surface is marked with a plurality of optically detectable sensing marks, said optically detectable sensing marks having transverse lines extending transversely of said primary movement direction and angled lines extending at an angle to said primary movement direction, and wherein said optically detectable sensing marks are detected by an optical sensing marks sensor, wherein; said sensing marks sensor comprises a linear array of a multiplicity of individual optical sensors, said sensing marks sensor optically detects said optical sensing marks to provide positional signals from said moving surface in said primary movement direction from said transverse lines extending transversely of said primary movement direction being moved past said sensing marks sensor, and said sensing marks sensor optically detects said optical sensing marks to provide transverse positional signals from said moving surface orthogonal to said primary movement direction from said angled lines extending at an angle to said primary movement direction by signals from respective said individual optical sensors which are actuated by a movement of said moving surface being moved past said sensing marks sensor in said primary movement direction in between a said transverse line extending transversely of said primary movement direction and a said angled line extending at an angle to said primary movement direction.