| Patent application number | Description | Published |
|---|
| 20100079767 | DISPLACEMENT MEASUREMENT APPARATUS - A displacement measurement apparatus includes a first diffraction grating transmitting light from a light source and producing diffracted beams including first to third diffracted beams output in different directions; a second diffraction grating movable together with an object to be measured, provided in a plane parallel to the first diffraction grating, and reflecting the first to third diffracted beams transmitted through the first diffraction grating; a first photodetector receiving the first and second diffracted beams diffracted by the second diffraction grating; a second photodetector receiving at least the third diffracted beam transmitted through the first diffraction grating; and a calculation unit calculating displacement of the object in a first direction in accordance with the beams received by the first photodetector, and displacement of the object in a second direction, different from the first direction, in accordance with the beam received by the second photodetector. | 04-01-2010 |
| 20100103403 | WAVELENGTH SHIFT MEASURING APPARATUS, OPTICAL SOURCE APPARATUS, INTERFERENCE MEASURING APPARATUS, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD - A wavelength shift measuring apparatus of the present invention is a wavelength shift detection sensor (WLCD | 04-29-2010 |
| 20100208271 | ORIGIN DETECTION APPARATUS, DISPLACEMENT MEASUREMENT APPARATUS AND OPTICAL APPARATUS - An apparatus includes a light source, a scale which is configured to have first and second diffraction grating portions which differ from each other in a grating pitch, a light receiving portion configured to receive first and second interference light fluxes generated from interference of a plurality of diffraction light fluxes, at the first and second diffraction grating portions, respectively, a light flux emitted from the light source and have different orders of diffraction, and to output first and second periodic signals based on an intensity of the first and second interference light fluxes, respectively, and a computing unit configured to output, based on the first and second periodic signals a signal representing an origin of displacement of the scale. | 08-19-2010 |
| 20110096334 | HETERODYNE INTERFEROMETER - A heterodyne interferometer includes a light source, an optical system, and a signal generator including at least two light-receiving elements that respectively output a first signal and a second signal. The signal generator generates a third signal and a fourth signal of which phases are respectively shifted by 90° from phases of the first signal and the second signal, generates a first periodic signal by adding a signal that is obtained by multiplying the first signal and the second signal to a signal that is obtained by multiplying the third signal and the fourth signal, and generates a second periodic signal by subtracting a signal that is obtained by multiplying the first signal and the fourth signal from a signal that is obtained by multiplying the second signal and the third signal. | 04-28-2011 |
| 20110220780 | OPTICAL ENCODER - An optical encoder | 09-15-2011 |
| 20110222073 | OPTICAL ENCODER AND DISPLACEMENT MEASUREMENT APPARATUS HAVING THE SAME - An optical encoder ( | 09-15-2011 |
| 20110249270 | HETERODYNE INTERFEROMETRY DISPLACEMENT MEASUREMENT APPARATUS - A heterodyne interferometry displacement measurement apparatus includes a first optical system including a light source (LASER) and a diffraction grating (GT | 10-13-2011 |
| 20110299093 | INTERFEROMETER - An interferometer measures a displacement of an object to be measured by observing a fluctuation in intensity of interfering light generated by dividing light emitted from a light source into two light beams and overlaying the two light beams. The interferometer includes: a light-receiving unit including a light-receiving area including a plurality of partial areas and configured to detect the interfering light in each of the plurality of partial areas; and a processing unit configured to calculate a value of an index indicating uniformity of a phase distribution of the interfering light in the light-receiving area by using a detection result in each of the partial areas. | 12-08-2011 |
