Patent ID: 6654508
Filing Date: 2003-11-25
Classification: B41J,G01D,H03M

Abstract:
A system for referencing the position of a moving component, comprising:an encoder strip having a repeating pattern of fiducial marks having a period P; a first sensor, the first sensor and encoder strip being positioned to move relative to each other at a speed that is proportional to the speed the moving component, the first sensor generating a first signal in response to the relative movement of the first sensor and encoder strip, the first signal including a plurality of transitions corresponding to the repeating pattern; a second sensor, the second sensor and encoder strip being positioned to move relative to each other at a speed that is proportional to the speed the moving component, the second sensor generating a second signal in response to the relative movement of the second sensor and encoder strip, the second signal including a plurality of transitions corresponding to the repeating pattern; and a controller connected to receive the first signal and the second signal, the controller being responsive to the first and second signals to identify a direction of movement of the moving component, the controller being responsive to the first signal to estimate a position of the moving component.