SCALE ELEMENT FOR AN OPTICAL MEASURING DEVICE

Abstract

The present disclosure refers to a scale element for an optical measuring device having an incremental encoder and an interferometric sensor system, the scale element having a reflection layer on one of the surfaces of the scale element, which reflection layer is provided to cooperate with the interferometric sensor system, and the scale element further having a material measure, which is arranged in a direction pointing away from and spaced apart from the reflection layer and is provided to cooperate with the incremental sensor system, the reflection layer being configured and designed in such a way that the reflection layer is transmissive for light of certain wavelengths and reflective for other wavelengths.

Claims

1. Scale element for an optical measuring device having an incremental encoder and an interferometric sensor system, wherein the scale element comprises: a reflection layer on one of its surfaces, which is provided for cooperation with an interferometric sensor system; and a material measure, which is arranged in a direction away from and spaced apart from the reflection layer and is provided for cooperation an incremental encoder, the reflection layer being such that it is transparent for light of certain wavelengths and reflective for light of other wavelengths.

2. Scale element according to claim 1, wherein the material measure is arranged on a surface of the scale element which is opposite to the surface provided with the reflection layer.

3. Scale element according to claim 1, wherein the scale element comprises: a substrate of a glass-like material.

4. Scale element according to claim 3, wherein the substrate consists of hardened sapphire glass.

5. Measuring device for position and/or location detection of a positioning element, the measuring device comprising: an incremental encoder; an interferometric sensor system; and a scale element according to claim 1, wherein the reflection layer is provided for cooperation with the interferometric sensor system and the material measure is provided for cooperation with the incremental encoder.

6. Measuring device according to claim 5, wherein the incremental encoder comprises: a read head; a first light source for emitting light of a first wavelength; and the material measure of the scale element associated with the read head, and wherein the interferometric sensor system comprises: a sensor head; a second light source for emitting light of a second wavelength; and the reflection layer of the scale element associated with the sensor head, the reflection layer facing both the read head and the sensor head, and the reflection layer being transmissive for the light of the first wavelength and reflective for the light of the second wavelength, wherein the interferometric sensor system is configured to use light of the second wavelength reflected by the reflection layer and detected by the sensor head for measurement, and the incremental encoder is configured to use light of the first wavelength reflected by the measuring body and detected by the reading head for measurement.

7. Measuring device according to claim 6, wherein the scale element is plate-shaped and the incremental encoder is configured and arranged to detect a position and location of the scale element within a plane defined by the scale element, and the interferometric sensor system is configured and arranged to detect a position of the scale element perpendicular to the plane defined by the scale element and a location of the scale element due to a rotation around one of two axes extending perpendicular to each other and in the plane of the scale element.

8. Measuring device according to claim 5, wherein the interferometric sensor system has at least three sensor heads.

9. Positioning device comprising: a positioning element; and a measuring device according to claim 5, wherein the scale element is at least one of arranged on the positioning element or is an integral part of the positioning element, and the measuring device is configured to infra a position or location, or the position and location, of the positioning element.

10. Scale element according to claim 2, wherein the scale element comprises: a substrate of a glass-like material.

11. Scale element according to claim 10, wherein the substrate consists of hardened sapphire glass.

12. Measuring device for position and/or location detection of a positioning element, the measuring device comprising: an incremental encoder: an interferometric sensor system; and a scale element according to claim 11, wherein the reflection layer is provided for cooperation with the interferometric sensor system and the material measure is provided for cooperation with the incremental encoder.

13. Measuring device according to claim 12, wherein the incremental encoder comprises: a read head; a first light source for emitting light of a first wavelength; and the material measure of the scale element associated with the read head, and wherein the interferometric sensor system comprises: a sensor head; a second light source for emitting light of a second wavelength; and the reflection layer of the scale element associated with the sensor head, the reflection layer facing both the read head and the sensor head, and the reflection layer being transmissive for the light of the first wavelength and reflective for the light of the second wavelength, wherein the interferometric sensor system is configured to use light of the second wavelength reflected by the reflection layer and detected by the sensor head for measurement, and the incremental encoder is configured to use light of the first wavelength reflected by the measuring body and detected by the reading head for measurement.

14. Measuring device according to claim 13, wherein the scale element is plate-shaped and the incremental encoder is configured and arranged to detect a position and location of the scale element within a plane defined by the scale element, and the interferometric sensor system is configured and arranged to detect a position of the scale element perpendicular to the plane defined by the scale element and a location of the scale element due to a rotation around one of two axes extending perpendicular to each other and in the plane of the scale element.

15. Measuring device according to claim 14, wherein the interferometric sensor system has at least three sensor heads.

16. Positioning device comprising: a positioning element; and a measuring device according to claim 15, wherein the scale element is at least one of arranged on the positioning element or is an integral part of the positioning element, and the measuring device is configured to infer a position or location, or the position and location, of the positioning element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the following description, additional features and advantages will be apparent to those skilled in the art from reading a detailed description of exemplary embodiments, as described with respect to the accompanying drawing, wherein:

[0026] FIG. 1 shows an exemplary embodiment of a scale element.

[0027] An embodiment of the invention is described below on the basis of the attached single FIG. 1. This shows a scale element 1 according to the invention with a plate-shaped geometry. The substrate 2 consists of a hardened sapphire crystal. On the surface of the substrate 2 facing upwards in FIG. 1, a scale element 3 in the form of a two-dimensional grid or a 2D-grid 3 is arranged over the entire surface. A reflection layer 4 is arranged on the surface of the substrate 2 opposite the 2D-grid 3. The reflection layer 4 has a high optical reflection at a light wavelength of 1550 nm and a high transmission at a light wavelength of 640 nm.