Patent ID: 7184121

Claim:
A lithographic apparatus, comprising: an illumination system configured to direct a beam of radiation; a support configured to support a patterning device that imparts the beam of radiation with a pattern in its cross-section; a substrate holder configured to hold a substrate; a projection system configured to project the patterned beam onto a target portion of the substrate; and a collision protection system configured to avoid collisions between a first and a second part of the apparatus in which at least one actuator system can generate relative displacement between the first and second parts, the collision protection system comprising: at least one sensor system to determine the relative position and/or velocity of the first and second parts, and a controller to control the at least one actuator system to prevent the first and second parts from moving closer together in the event that the sensor system determines that the relative position and/or velocity of the first and second parts indicate a potential collision.