Multiturn rotary encoder with multiple code carriers coupled by a reduction gear

• US 6,542,088 B1
• Filed: 03/28/2001
• Issued: 04/01/2003
• Est. Priority Date: 05/06/1998
• Status: Expired due to Fees

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Meyer, Hermann, Spies, Alfons, Mitterreiter, Johann, Feichtinger, Kurt, Strasser, Erich, Schroter, Andreas, Bielski, Steffen
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Mai, Lam T.
• Application Number:
  US09/674,840
• Time in Patent Office: 734 Days
• Field of Search: 341/15, 341/13, 341/9, 341/16, 341/171, 341/11, 341/12, 341/14
• US Class Current: 341/15
• CPC Class Codes: G01B 7/30 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01D 2205/26 Details of encoders or position sensors specially adapted to detect rotation beyond a full turn of 360°, e.g. multi-rotation
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/2458 with incremental and absolute tracks on separate encoders

Abstract

A multi-turn rotary encoder that includes a first code carrier connected with an input shaft, a scanning device that scans the first code carrier and generates an absolute position of the input shaft within one revolution, and a digital code word is present at an output of the scanning device and a second code carrier for measuring the number of revolutions of the input shaft. A reduction gear is arranged between and coupled to the first and second code carriers. The second code carrier includes a magnetic body with at least one north and south pole and a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with the magnetic body. An evaluation circuit integrated into the substrate, wherein scanning signals, which are phase-shifted with respect to each other, from the sensor elements are supplied, and that the evaluation circuit combines the scanning signals in such a way that a second digital code word is present serially or in parallel at an output of the evaluation circuit. A combination logical device, which is supplied with the first and second digital code words and which forms a resultant multi-digit code word therefrom.

Claims

1. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit; and

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom.

2. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit;

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom;

wherein said second code carrier comprises a magnetic body with only a single north and south pole, so that each of said sensor elements generates a periodic sinusoidal scanning signal per revolution of said magnetic bodies.

3. The multi-turn rotary encoder in accordance with claim 2, further comprising a third code carrier, wherein said second and third code carriers are driven at different reductions by said input shaft, and each of said second and third code carriers is scanned by corresponding first and second semiconductor substrates.

4. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body;

a third code carrier, wherein said second and third code carriers are driven at different reductions by said input shaft, and each of said second and third code carriers is scanned by corresponding first and second semiconductor substrates;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit; and

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom.

5. The multi-turn rotary encoder in accordance with claim 4, wherein said first and second semiconductor substrates are identically designed.

6. The multi-turn rotary encoder in accordance with claim 4, wherein said second and third carriers comprises a magnetic body with a single north and south pole.

10. The multi-turn rotary encoder in accordance with claim 6, wherein said sensor elements are integrated into a common semiconductor substrate for scanning said second and third code carriers.

7. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body and wherein said substrate comprises a semiconductor;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit; and

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom.

8. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body and wherein each of said sensor elements comprises a Hall element;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit; and

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom.

9. The multi-turn rotary encoder in accordance with claim 8, wherein said sensor elements form an array arrangement with n sensor elements, with n greater than or equal to four.

11. A multi-turn rotary encoder, comprising:

a first code carrier connected with an input shaft;

a scanning device that scans said first code carrier and generates an absolute position of said input shaft within one revolution, and a digital code word is present at an output of said scanning device;

a second code carrier for measuring the number of revolutions of said input shaft;

a reduction gear arranged between and coupled to said first code carrier and said second code carrier, wherein said reduction gear causes said first code carrier to rotate about a direction of rotation, as well as a displacement along a displacement direction that is superimposed on said rotation;

said second code carrier comprises a magnetic body with at least one north and south pole;

a substrate with a spatial arrangement of sensor elements integrated therein, which are sensitive to magnetic fields, is associated with said magnetic body;

an evaluation circuit integrated into said substrate, wherein scanning signals, which are phase-shifted with respect to each other, from said sensor elements are supplied, and that said evaluation circuit combines said scanning signals in such a way that a second digital code word is present serially or in parallel at an output of said evaluation circuit; and

a combination logical device, which is supplied with said first and second digital code words and which forms a resultant multi-digit code word therefrom.

12. The multi-turn rotary encoder in accordance with claim 11, wherein said sensor elements are integrated two-dimensionally in said direction of rotation, as well as in said displacement direction, next to each other in a semiconductor substrate.