MEASUREMENT METHOD AND ENCODER DEVICE, AND EXPOSURE METHOD AND DEVICE

摘要

There is provided an encoder device to measure a relative moving amount between a first and second members. The encoder device includes: a reflective-type diffraction grating on the first member; a light source unit to radiate a measuring light; a first optical member on the second member; a first and second reflecting units on the second member that cause first and third diffracted lights generated via diffraction of the measuring light and having orders different from each other to come into the diffraction grating respectively, and cause second and fourth diffracted lights generated via diffraction of the first and third diffracted lights respectively to come into the first optical member; photo-detectors configured to detect interference lights between two diffracted lights and other light beam respectively; and a measuring unit to obtain the relative moving amount by using detection signals from the photo-detectors.

主权项

1. An encoder device configured to measure a relative moving amount between a first member and a second member which is supported to be movable relative to the first member at least in a first direction, the encoder device comprising:
a reflective-type diffraction grating provided on the first member and having a grating pattern of which periodic direction is at least the first direction; a light source unit configured to radiate a measuring light; a first optical member provided on the second member and causing the measuring light to come substantially perpendicularly into a surface of the grating pattern of the diffraction grating; a first reflecting unit provided on the second member; causing a first diffracted light, which is generated, via diffraction of the measuring light, from the diffraction grating in the first direction, to come into the diffraction grating; and causing a second diffracted light, which is generated, via diffraction of the first diffracted light, from the diffraction grating, to come into the first optical member; a second reflecting unit provided on the second member; causing a third diffracted light, of which order is different from order of the first diffracted light and which is generated, via diffraction of the measuring light, from the diffraction grating in the first direction, to come into the diffraction grating; and causing a fourth diffracted light, which is generated, via diffraction of the third diffracted light, from the diffraction grating, to come into the first optical member; a first photo-detector configured to detect an interference light generated by interference between the second diffracted light via the first optical member and other light beam than the second diffracted light; a second photo-detector configured to detect an interference light generated by interference between the fourth diffracted light via the first optical member and other light beam than the fourth diffracted light; and a measuring unit configured to obtain the relative moving amount between the first member and the second member by using detection signals from the first and second photo-detectors.