Matches 1 - 34 out of 34


Match Document Document Title
9030668 Method for spatially multiplexing two or more fringe projection signals on a single detector  
Fringe patterns at first and second spatial frequencies are projected onto a work piece surface and a reference surface, respectively. An image of the projected fringe patterns is obtained and a...
8885172 Interferometric heterodyne optical encoder system  
An encoder interferometry system includes an interferometer positioned to receive first and second beams having different frequencies, in which the interferometer has at least one polarizing beam...
8422025 Optical encoder for obtaining displacement information of object  
An optical encoder includes a light source 10, a scale 20 disposed so as to face the light source, a light receiving element 31 configured to receive luminous flux from the light source through...
8416424 Laser self-mixing measuring device  
A laser self-mixing measuring device is provided, comprising a laser with a laser cavity and a surface arranged along the optical path of the laser beam which redirects incident laser light back...
8300233 Interferometric encoder systems  
A method for determining information about changes along a degree of freedom of an encoder scale includes directing a first beam and a second beam along different paths and combining the first and...
8189176 Velocity detector  
A method of detecting the velocity of a moving object comprising the steps of: passing a beam of coherent light through an optical mask having a pattern of alternating opaque and non-opaque...
7636165 Displacement measurement systems lithographic apparatus and device manufacturing method  
A displacement measurement system configured to provide measurement of the relative displacement of two components in six degrees of freedom with improved consistency and without requiring...
7443518 Measuring instrument, in particular for transmission measurement in vacuum system  
A measuring instrument, in particular for transmission measurement with transparent substrates, comprises a measuring head with a light emitting element for emitting a light beam and a light...
7046368 Position measuring arrangement  
A position measuring arrangement for determining a relative position between a first object and a second object. The arrangement includes a light source having a single-mode laser light source...
6919561 Diffraction laser encoder apparatus  
A diffraction laser encoder apparatus for positional and movement information measurement of a target made with a diffraction grating. The diffraction laser encoder has a laser light source for...
6674519 Optical phase front measurement unit  
An adaptive optics system configured as an optical phase front measurement system which provides for relatively high resolution sampling as in holographic techniques but without the need for a...
6304318 Lithography system and method of manufacturing devices using the lithography system  
A lithography system for exposing a photosensitive member includes a photosensitive member placement unit, and an interference optical system. The interference optical system produces interference...
6204926 Methods and system for optically correlating ultrashort optical waveforms  
The invention features methods and systems for optical correlation of ultrashort optical waveforms, e.g., pulses. The optical waveform passes through a diffractive optic, e.g., a mask or grating,...
5818588 Displacement measuring method and apparatus using plural light beam beat frequency signals  
A displacement measuring method for measuring displacement of an object to be examined is disclosed, wherein light which contains two components having a small difference in frequency is separated...
5751426 Positional deviation measuring device and method for measuring the positional deviation between a plurality of diffraction gratings formed on the same object  
A device and method for measuring the positional deviation between a plurality of diffraction gratings formed on the same object include an illumination optical system for illuminating the...
5682239 Apparatus for detecting positional deviation of diffraction gratings on a substrate by utilizing optical heterodyne interference of light beams incident on the gratings from first and second light emitters  
Apparatus for detecting a positional deviation of two diffraction gratings of each of first and second pairs of diffraction gratings formed on a substrate, by utilizing an optical heterodyne...
5625453 System and method for detecting the relative positional deviation between diffraction gratings and for measuring the width of a line constituting a diffraction grating  
A deviation detecting system for detecting a relative positional deviation between first and second diffraction gratings, includes a light source, an illuminating device for projecting first and...
5541729 Measuring apparatus utilizing diffraction of reflected and transmitted light  
In measuring apparatus for detecting relative displacement of a diffraction grating, a light beam is separated in an optical unit such as polarizing beam splitter into a reflected light beam and a...
5498878 Method and apparatus for detecting positional deviation by using diffraction gratings with a compensation delay determining unit  
A method and apparatus for measuring relative positional deviation between first and second diffraction gratings formed on an object is disclosed, wherein, in detection of a signal corresponding...
5448357 Position detecting system for detecting a position of an object by detecting beat signals produced through interference of diffraction light  
A position detecting system is disclosed wherein lights being mutually coherent and having first and second frequencies, respectively, different from each other are produced, and the light of the...
5436724 Apparatus for measuring relative movement using a diffraction grating having an orthogonally polarized input beam  
An apparatus for measuring relative movement by the use of a diffraction grating includes a light beam generating portion generating a light beam including light wave components having planes of...
5404220 Measuring method and measuring apparatus for determining the relative displacement of a diffraction grating with respect to a plurality of beams  
A method and an apparatus for measuring a very small displacement of an object. The first and second beat signals are produced by light beams of different frequencies diffracted by a diffraction...
5369486 Position detector for detecting the position of an object using a diffraction grating positioned at an angle  
A position detector includes a diffraction grating provided on the surface of an object, an illumination system for illuminating the diffraction grating, a detection system for detecting...
5327222 Displacement information detecting apparatus  
A displacement information measuring apparatus comprising light emitting source for emitting two light fluxes, acoustic optical device for giving a predetermined frequency difference to the two...
5164789 Method and apparatus for measuring minute displacement by subject light diffracted and reflected from a grating to heterodyne interference  
The present invention resides in method and apparatus for measuring a minute displacement, comprising applying a light of a first wavelength at a predetermined angle to a diffraction grating...
5141317 Method of optoelectronically measuring distances and angles  
A method for optoelectronically measuring distances and/or angles is suggested. A first and second beam (13, 14 and 61, 63) are directed onto the surface 12 of an object 10 to be measured at...
RE34010 Position detection apparatus  
An apparatus includes a means for providing a predetermined frequency difference between two light beams and generating an optical beat with respect to interference between first and second...
5118932 Shaft rotation rate sensor with a diffraction grating producing a velocity-related beat frequency  
A shaft rotation rate sensor for turbine engines. A reflective radial grating on the surface of the turbine shaft is employed in conjunction with an electromagnetic wave source and beam combining...
5050993 Diffraction encoded position measuring apparatus  
When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a...
5000572 Distance measuring system  
A device for measuring a moving distance of two relatively moving objects includes a first diffraction grating provided on one of the two objects and disposed along the relatively moving direction...
4815850 Relative-displacement measurement method  
A relative displacement among a plurality of objects is measured with a high degree of accuracy by utilizing diffraction and interference phenomena of waves through diffraction gratings formed on...
4772119 Device for detecting a magnification error in an optical imaging system  
A device is described for detecting a magnification error in an optical imaging system comprising a lens system (L1, L2) which is telecentric at one side. Two gratings (RG1, RG2) arranged in the...
3930734 Process and apparatus for sensing magnitude and direction of lateral displacement  
Process and apparatus therefor for sensing the magnitude and direction of lateral displacement of at least one line or slit element of an article which comprises producing two coherent light beams...
3891321 Optical method and apparatus for measuring the relative displacement of a diffraction grid  
Optical means for measuring the relative displacement of a one- or two-dimensional diffraction grating in its plane of division along one or two coordinate directions, with illumination of the...

Matches 1 - 34 out of 34