Patent ID: 7633599
Filing Date: 2009-12-15
Classification: G03F

Abstract:
1. An apparatus for changing an intensity distribution of a light within an illumination field, comprising: a structure configured to be positioned within the illumination field so that a first portion of the light within the illumination field impinges upon the structure, the first portion of the light having a first area defined by a first value, wherein the structure is one of translucent to a wavelength of the light and opaque to the wavelength; and an actuator configured to cause a movement of a first portion of the structure so that a second portion of the light within the illumination field impinges upon the structure, the first portion of the structure being a flap coupled to a second portion of the structure, the second portion of the light having a second area defined by a second value, the second value different from the first value; wherein the light within the illumination field is produced by a source configured so that a pupil fill of a beam of the light is uncontrolled, but the beam of the light downstream of the structure is substantially telecentric before and after the movement of the first portion of the structure.