Displacement measurement sensor head and system having measurement sub-beams comprising zeroth order and first order diffraction components
First Claim
1. A sensor head for use with a measurement grating, the sensor head comprising:
- a splitter grating configured to split a light beam into first and second measurement beams;
a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and
a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating, wherein the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component.
2 Assignments
0 Petitions
Accused Products
Abstract
A sensor head for use with a measurement grating is described. The sensor head comprises: a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating. In one embodiment the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component. In another embodiment, the first and second sub-beams each comprise a zeroth order diffraction component and a first order diffraction component.
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Citations
21 Claims
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1. A sensor head for use with a measurement grating, the sensor head comprising:
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a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating, wherein the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A sensor head for use with a measurement grating, the sensor head comprising:
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a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating, wherein the first and second measurement beams are diffracted by the measurement grating to form respective first and second sub-beams of each of the first and second measurement beams and the first and second sub-beams each comprise a zeroth order diffraction component and a first order diffraction component. - View Dependent Claims (12, 13)
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14. A sensor head for use with a measurement grating, the sensor head comprising:
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a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating, wherein the first and second measurement beams are diffracted by the measurement grating to form respective first and second sub-beams of each of the first and second measurement beams and the first and second sub-beams each comprise only zeroth order diffraction components or first order diffraction components. - View Dependent Claims (15, 16, 17)
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18. A method of measuring a displacement, the method comprising:
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splitting a light beam into first and second measurement beams; directing the first measurement beam toward a measurement grating; directing the second measurement beam toward the measurement grating; and diffracting the first and second measurement beams into respective first and second sub-beams, wherein one of the sub-beams comprises a zeroth-order diffraction component and a first order diffraction component. - View Dependent Claims (19, 20, 21)
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Specification