Area Sensing Encoder
The requirement was to control the movement of a large moving stage with high accelerations. For this purpose, it was required to provide a position sensing device able to detect positioning in one axis while being indifferent to movements in the second axis of a plane.
The solution should be fully operational in the presence of strong magnetic fields.
The following implementation was developed: A rectangular scale of 140 x 150 mm and an active read head implement an incremental encoder solution which is sensible to movements in one axis while being completely indifferent to the movement in the second axis of the scale plane.
The solution is in full production since 2005 and a vacuum compliant version is in production since 2010.
| Mechanical operational range (X, Y) | (80 mm, 80 mm) |
| Repeatability | +/- 10μm |
| Absolute accuracy over full range2 | +/- 25μm |
| Resolution | 1 μm |
| Maximum operating speed (Vx,Vy) | 0.5 m/sec |
| Air gap (Z) | 0.8±0.2 mm |
