Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrometer
Patent
1984-07-30
1987-01-13
Willis, Davis L.
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrometer
G01B 0902
Patent
active
046360760
ABSTRACT:
Apparatus for measuring displacement comprises a member, such as a reading head, which carries a stepped index diffraction grating (14) and is movable with respect to a reflective scale grating (16). The head also carries a source (10) and lens for directing light on to the index grating and then on to the scale grating for reflection to the index grating, with the resultant Moire bands detected by a photodetector (18) on the reading head. In order to determine the phase separation or offset, and to avoid high sensitivity thereof to the spacing between the gratings, the index grating (14) has a square-stepped profile resulting in graded, increasing thickness. Alternatively, a conventional index grating may be employed in conjunction with a stepped profile optical element interposed between the two gratings.
REFERENCES:
Rassudova et al., "Miniature Sensor of Linear Displacements", Sov. J. Opt. Technol., vol. 43, No. 4, pp. 235-237, Apr. 1976.
USSR Inventor's Certificate No. 1,093,889.
G. S. Landsberg "Optics", Moscow, 1954, pp. 167-169 .sctn.50, Michelson's Echelon.
Optics & Spectroscopy, vol. 14, 1963, pp. 215-219, Rassudova and Gerasimov, Use of Reflecting Diffraction Gratings in Interference Systems for Measuring Linear Shifts.
Dr. Johannes Heidenhain GmbH
Koren Matthew W.
Willis Davis L.
LandOfFree
Displacement measuring apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Displacement measuring apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Displacement measuring apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2352753