Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1987-10-02
1988-12-20
Nelms, David C.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
250237G, 356374, G01D 534
Patent
active
047926783
ABSTRACT:
In a photoelectric measuring device for measuring the position of two objects which can be rotated relative to each other, a grid located on a graduation support, which is connected with one of the objects, is scanned by a scanning device connected with the other object. To eliminate the eccentricity between the grid and the rotational axis of the graduation support, the light beam emitted by a light source is split in a first graduation area of the grid into two first order diffraction beams, at two diffraction angles. After two-fold deviation by two parallel mirrors, the first order diffraction beams are again joined, in a second graduation area of the grid that lies diametrically opposite the first graduation area. The first order diffraction beams join at the same diffraction angles at which they were emitted from the first graduation area of the grid. Consequently, the beams at the second graduation area are parallel to themselves as they were emitted at the first graduation area.
REFERENCES:
patent: 3612695 (1971-10-01), Bouwhuis et al.
patent: 3628026 (1971-12-01), Cronin
patent: 4629886 (1986-12-01), Akiyama et al.
"Laser Rotary Encoders," Nishimura et al., Motion, Jul./Aug. 1986, pp. 3-4.
"Laser Rotary Encoders," Nishimura et al., Motion, Sep./Oct. 1986, pp. 14-18.
"Photoelectrical Measurement of the Change of Lengths or Angular Positions with the Help of Diffraction Lattices," Hock, Dissertion Approved by the University of Stuttgart, submitted 10/29/75; pp. 183-184.
Dr. Johannes Heidenhain GmbH
Nelms David C.
LandOfFree
Photoelectric angle measuring device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photoelectric angle measuring device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoelectric angle measuring device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1910554