Optoelectronic position measuring device including a code carrier, a radiation source, and a detection element

Patent metadata

Field	Value
Publication number	US-9816842-B2
Application number	US-201314383482-A
Country	US
Kind code	B2
Filing date	Mar 6, 2013
Priority date	Mar 9, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Embodiments described herein include an optoelectronic position measuring device that may include a code carrier, which carries an optically detectable position code, a radiation source for emitting optical radiation onto the code carrier, and a detection element having a multiplicity of light-sensitive reception regions for receiving at least part of the optical radiation, as a result of which a scanning signal dependent on the position code can be generated and a position of the code carrier relative to the detection element can thus be detected, wherein the measurement components are arranged in a fixed spatial relationship with respect to one another on a carrier element, the code carrier is movable with one degree of freedom, in particular rotationally or along an axis, and the code carrier and the carrier element are arranged at a fixed spatial distance with respect to one another.

First claim

What is claimed is:

1. An optoelectronic position measuring apparatus, comprising
a code carrier, which carries an optically detectable position code,
a radiation source for emitting optical radiation onto the code carrier and
a detection element having a multiplicity of light-sensitive receiving regions for receiving at least part of the optical radiation, as a result of which a scanning signal dependent on the position code can be generated and a position of the code carrier relative to the detection element can thus be detected, wherein
the measuring components radiation source and detection element are arranged on a carrier element in a fixed spatial relationship with respect to one another and in each case with an end side facing the code carrier, in each case have a height between the end side and a base, and in each case have an overhang between the end side and a front side of the carrier element, said front side facing the code carrier,
the carrier element is a printed circuit board,
the code carrier is arranged parallel to the front side of the carrier element, directly opposite to the radiation source and to the detection element, and movable with one degree of freedom, and
the code carrier and the carrier element are arranged at a fixed spatial distance with respect to one another, the distance being at least of the same magnitude as the overhang of the radiation source, and being at least of the same magnitude as the overhang of the detection element,

wherein at least that measuring component having the greater height is arranged on a plane that is parallel to the code carrier and situated further away from the code carrier in comparison with the front side such that its overhang is less than its height,
wherein a smaller value can be chosen for the distance, compared with an apparatus in which the measuring components are arranged on a plane defined by the front side,
wherein:
in the surface of a rear side of the carrier element, said rear side facing away from the code carrier, a depression is provided, which has an opening to the front side of the carrier element,
the radiation source is fitted in the depression, and

the radiation source and the opening are aligned with one another in such a way that optical radiation from the radiation source can be emitted through the opening onto the code carrier, wherein the opening serves as a diaphragm.

2. The optoelectronic position measuring apparatus according to claim 1 , wherein the overhang of the measuring components in each case has a positive value, has a negative value or is equal to zero.

3. The optoelectronic position measuring apparatus according to claim 1 , wherein the radiation source and/or the detection element are/is arranged on the carrier element in a respective depression.

4. The optoelectronic position measuring apparatus according to claim 1 , wherein the radiation source and/or the detection element on the carrier element with their/its end side do(es) not project beyond the front side of the carrier element in the direction of the code carrier.

5. The optoelectronic position measuring apparatus according to claim 1 , wherein the radiation source and/or the detection element are/is constructed on the carrier element without a housing, in a manner free of covering glass, and/or have/has a copper layer.

6. The optoelectronic position measuring apparatus according to claim 1 , wherein the radiation source and the detection element are arranged on the carrier element respectively on a plane situated further away from the code carrier than the front side of the carrier element.

7. The optoelectronic position measuring apparatus according to claim 1 , wherein
the depression is closed toward the rear side by means of a closure,
a part of the carrier element that is situated between the depression and the front side is made opaque, and/or
the opening is filled wholly or partly with an optical filling adhesive which has either
a planar surface that forms a planar area with the front side of the carrier element, or
an optical diffractive or refractive surface at the front side of the carrier element.

8. The optoelectronic position measuring apparatus according to claim 1 , wherein
the depression is filled wholly or partly with an optical filling adhesive, which has a planar surface that forms a planar area with the front side of the carrier element, or
has an optical diffractive or refractive surface at the front side of the carrier element.

9. The optoelectronic position measuring apparatus according to claim 1 , wherein
the code carrier is configured as a circular disc,
is rotatable about an axis, wherein an angle of rotation about the axis can be detected by the detection element, and/or
has beam deflection means in the form of mirrors and/or waveguides, in order to direct the radiation emitted by the radiation source onto the detection element by reflection.

10. The optoelectronic position measuring apparatus according to claim 1 , wherein the radiation source is configured as an LED or a laser diode.

11. The optoelectronic position measuring apparatus according to claim 1 , wherein the detection element is configured as a sensor array.

12. The optoelectronic position measuring apparatus according to claim 1 , wherein
the carrier element is assembled from a plurality of layers.

13. The optoelectronic position measuring apparatus according to claim 1 , wherein the position code is fitted substantially over the whole area on that side of the code carrier which faces the carrier element.

14. A method for producing an optoelectronic position measuring apparatus, wherein the optoelectronic position measuring apparatus comprises:
a code carrier, which carries an optically detectable position code,
a radiation source for emitting optical radiation onto the code carrier,
a detection element having a multiplicity of light-sensitive receiving regions for receiving at least part of the optical radiation, as a result of which a scanning signal dependent on the position code can be generated and a position of the code carrier relative to the detection element can thus be detected,
wherein
the radiation source and the detection element are arranged on a printed circuit board in a fixed spatial relationship with respect to one another and in each case with an end side facing the code carrier,
the code carrier is arranged parallel to the front side of the carrier element, directly opposite to the radiation source and to the detection element, and movable with one degree of freedom, and
the code carrier and the carrier element are arranged at a fixed spatial distance with respect to one another and in such a way that throughout operation of the optoelectronic position measuring apparatus the radiation source and the detection element face the code carrier with the end side,

wherein the method comprises:
producing a depression on the rear side of the printed circuit board,
producing an opening between the depression and the front side, and
arranging the radiation source in the depression, such that optical radiation from the radiation source can be emitted through the opening onto the code carrier, wherein the opening serves as a diaphragm.

15. The method for producing an optoelectronic position measuring apparatus according to claim 14 , further comprising closing the depression at the rear side, wherein the radiation source is fitted to a closure, by means of which the depression is closed.

16. The method for producing an optoelectronic position measuring apparatus according to claim 14 , w

Assignees

• Hexagon Technology Ct Gmbh

Inventors

• Vokinger Urs
• Amann Werner

Classifications

• G01D5/347 Primary

  using displacement encoding scales · CPC title

• G01D5/34 Primary

  the beams of light being detected by photocells · CPC title