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US3573468A
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Photoelectric incremental transducer for 4-phase signals comprising means for geometrically splitting the light beams
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1969-10-16
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Granted: 1971-04-06
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Expires: 1989-10-16
Abstract
Abstract In a photoelectric incremental transducer wherein the grating is reproduced after a polarizing image splitting step, either onto a second grating or onto itself and indexing images are reproduced thereafter by way of a polarizing splitter and position-defining signals are obtained at at least two photoelectric receivers, the improvement comprising the insertion of a geometric splitter which produces an image shift of one-half a graduation interval in the image beam path behind the place of reproduction in the plane conjugate with respect to the geometric splitter, and means are provided for the separate reception of the different beams.
Inventors
- 👤 Karl Lang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:24
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/36; G01D5/38; G01D5/347; G01D5/34707; G01D5/34715
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
282 words
A photoelectric incremental transducer comprising: a grating (41'',11'') having an index interval, said grating being displaceable; a light source (12) illuminating part of said grating; optical means (14,23) adapted to project an image of said illuminated part of said grating onto a second part of said grating, said optical means further including: means (19) for doubling the light beams passing through said grating thereby polarizing each of said beams in directions normal to each other, said means (19) disposed on the opposite side of the grating from the location of said light source; and means (26,27) for geometrically splitting said light beams by one-half of said index interval, said means (26,27) disposed in the path of said light beams; a beam splitting element (25) located in the path of said light beams on the same side of the grating as said light source polarizing the image beams from said means for geometrically splitting; a first and a second hemihedral mirror (30,31) located in the path of said polarized image beams and reflecting the portions of said image beams; a first pair of photoelectric receivers (32, 33) receiving said portion of image beams from said first hemihedral mirror and generating two position-defining photoelectric current signals; a second pair of photoelectric receivers (34,35) receiving said portion of image beams from said second hemihedral mirror and generating two position-defining photoelectric current signals; two push-pull amplifiers (36,37) with high common mode rejection to which the four generated signals are conducted in pairs; a discriminator for determining the counting direction (38) to which the output signals of said amplifiers are conducted; and an up-down-counter (39) connected to said discriminator for digitally indicating the result of the measurement.
Claim 2
Dependent Claim
282 words
A photoelectric incremental transducer comprising: a grating (41'',11'') having an index interval, said grating being displaceable; a light source (12) illuminating part of said grating; optical means (14,23) adapted to project an image of said illuminated part of said grating onto a second part of said grating, said optical means further including: means (19) for doubling the light beams passing through said grating thereby polarizing each of said beams in directions normal to each other, said means (19) disposed on the opposite side of the grating from the location of said light source; and means (26,27) for geometrically splitting said light beams by one-half of said index interval, said means (26,27) disposed in the path of said light beams; a beam splitting element (25) located in the path of said light beams on the same side of the grating as said light source polarizing the image beams from said means for geometrically splitting; a first and a second hemihedral mirror (30,31) located in the path of said polarized image beams and reflecting the portions of said image beams; a first pair of photoelectric receivers (32, 33) receiving said portion of image beams from said first hemihedral mirror and generating two position-defining photoelectric current signals; a second pair of photoelectric receivers (34,35) receiving said portion of image beams from said second hemihedral mirror and generating two position-defining photoelectric current signals; two push-pull amplifiers (36,37) with high common mode rejection to which the four generated signals are conducted in pairs; a discriminator for determining the counting direction (38) to which the output signals of said amplifiers are conducted; and an up-down-counter (39) connected to said discriminator for digitally indicating the result of the measurement.
Claim 3
Dependent Claim
25 words
The photoelectric incremental transducer of claim 1, wherein said means for geometrically splitting are half-lenses offset with respect to each other with their central axes.
Claim 4
Dependent Claim
17 words
The photoelectric incremental transducer of claim 1, wherein said means for geometrically splitting is an optical wedge.
Claim 5
Dependent Claim
27 words
The photoelectric incremental transducer of claim 1, wherein said means for geometrically splitting are parallel plates, each of which picks up the image beam path only partially.
Claim 6
Dependent Claim
246 words
A photoelectric incremental transducer comprising: a grating (41'',11'') having an index interval, said grating being displaceable; a light source (12) illuminating part of said grating; optical means (14,23) adapted to project an image of said illuminated part of said grating onto a second part of said grating; said optical means further including: means (19) for doubling the light beams passing through said grating thereby polarizing each of said beams in directions normal to each other, said means (19) disposed on the opposite side of the grating from the location of said light source; and means (26,27) for geometrically splitting said light beams by one-half of said index interval, said means (26,27) disposed in the path of said light beams; a beam splitting element (25) located in the path of said light beams on the same side of the grating as said light source polarizing the image beams from said means for geometrically splitting; a first differential photoreceptor located in the path of said polarized image beams and generating two position-defining photoelectric current signals; a second differential photoreceptor located in the path of said polarized image beams and generating two position-defining photoelectric current signals; two push-pull amplifiers (36,37) with high common mode rejection to which the four generated signals are conducted in pairs; a discriminator for determining the counting direction (38) to which the output signals of said amplifiers are conducted; and an up-down-counter (39) connected to said discriminator for digitally indicating the result of the measurement.
Claim 7
Dependent Claim
246 words
A photoelectric incremental transducer comprising: a grating (41'',11'') having an index interval, said grating being displaceable; a light source (12) illuminating part of said grating; optical means (14,23) adapted to project an image of said illuminated part of said grating onto a second part of said grating; said optical means further including: means (19) for doubling the light beams passing through said grating thereby polarizing each of said beams in directions normal to each other, said means (19) disposed on the opposite side of the grating from the location of said light source; and means (26,27) for geometrically splitting said light beams by one-half of said index interval, said means (26,27) disposed in the path of said light beams; a beam splitting element (25) located in the path of said light beams on the same side of the grating as said light source polarizing the image beams from said means for geometrically splitting; a first differential photoreceptor located in the path of said polarized image beams and generating two position-defining photoelectric current signals; a second differential photoreceptor located in the path of said polarized image beams and generating two position-defining photoelectric current signals; two push-pull amplifiers (36,37) with high common mode rejection to which the four generated signals are conducted in pairs; a discriminator for determining the counting direction (38) to which the output signals of said amplifiers are conducted; and an up-down-counter (39) connected to said discriminator for digitally indicating the result of the measurement.
References Cited (Backward Citations)
US3421011A
Cited
US3489908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |