REFLECTIVE MULTI-TURN ENCODER

• US 20090152452A1
• Filed: 12/18/2007
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Abandoned Application

• Current Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Wong, Weng Fei, Lee, Sze Kuang
• Application Number:
  US11/959,193
• Publication Number:
  US 20090152452A1
• Time in Patent Office: Days
• US Class Current: 250/231.150
• CPC Class Codes: G01D 5/04 using levers; using cams; using gearing
• CPC Class Codes: G01D 5/347 using displacement encoding scales
• CPC Class Codes: G01D 5/34715 Scale reading or illumination devices
• CPC Class Codes: G01D 5/34792 with only digital scales or both digital and incremental scales

Abstract

A reflective optical encoder for a gear train. The reflective optical encoder includes a gear train with a plurality of gears. Each of the gears is operably coupled to at least one other gear of the plurality of gears. A reflective code pattern is accessible on a surface of at least one of the gears. A reflective optical sensor detects light reflected by the reflective code pattern. Position logic coupled to the optical sensor determines a rotational parameter of the gear train based on the light reflected by the reflective code pattern. Additionally, the position logic may determine rotational parameter of a pinion coupled to the gear train based on the rotational parameter of the gear train.

Claims

1. A reflective optical encoder comprising:

a gear train with a plurality of gears, wherein each of the gears is operably coupled to at least one other gear of the plurality of the gears;

a reflective code pattern accessible on a surface of at least one of the gears;

a second reflective code pattern accessible on a second surface of the same gear within the gear train;

a reflective optical sensor to detect light reflected by the reflective code pattern; and

position logic coupled to the optical sensor, the position logic to determine a rotational parameter of the gear train based on the light reflected by the reflective code pattern.

2. The reflective optical encoder of claim 1, further comprising a pinion coupled to the gear train, wherein the position logic is further configured to determine a rotational parameter of the pinion based on the rotational parameter of the gear train.

3. The reflective optical encoder of claim 2, further comprising:

a first substrate operably coupled to the gear train, wherein the reflective optical sensor is coupled to the first substrate; and

a second substrate operably coupled to the gear train opposite the first substrate.

4. The reflective optical encoder of claim 1, wherein the code pattern is applied to the surface of the at least one of the gears of the gear train.

5. The reflective optical encoder of claim 1, wherein the code pattern is integrally formed as a part of the surface of the at least one of the gears of the gear train.

6. The reflective optical encoder of claim 1, wherein the code pattern comprises a reflective plastic film, a metal code disk, or a reflective coating applied to a plastic surface.

7. The reflective optical encoder of claim 1, wherein the reflective optical sensor comprises a chip-on-board device.

8. The reflective optical encoder of claim 1, wherein the reflective code pattern is accessible on a near surface of a layer of gears, within the gear train, that is closest to the reflective optical sensor.

9. The reflective optical encoder of claim 1, wherein the reflective code pattern is accessible on a near surface of a layer of gears, within the gear train, other than a layer of gears that is closest to the reflective optical sensor.

10. The reflective optical encoder of claim 1, further comprising:

a second reflective optical sensor to detect light reflected by the second reflective code pattern.

13. The reflective optical encoder of claim 1, wherein the reflective optical encoder comprises a multi-turn encoder.

15. The reflective optical encoder of claim 13, wherein the code pattern comprises a reflective plastic film applied to the surface of the gear.

16. The reflective optical encoder of claim 13, wherein the code pattern comprises a metal code disk coupled to the surface of the gear.

17. The reflective optical encoder of claim 13, wherein the code pattern comprises a reflective coating applied to the surface of the gear.

18. The reflective optical encoder of claim 13, further comprising:

a second reflective optical sensor to detect light reflected by the second reflective code pattern.

21. The reflective optical encoder of claim 10, further comprising a third reflective code pattern accessible on a surface of a different gear within the gear train.

11. (canceled)

12. (canceled)

14. A reflective optical encoder comprising:

a gear;

a reflective code pattern accessible on a surface of the gear;

a reflective optical sensor to detect light reflected by the reflective code pattern;

a second reflective code pattern accessible on a second surface of the same gear within the gear train; and

position logic coupled to the reflective optical sensor, the position logic to determine a rotational parameter of the gear train based on the light reflected by the reflective code pattern.

19. An apparatus comprising:

means for generating light incident on a surface of a gear within a gear train;

means for generating light incident on a second surface of the same gear within the gear train;

means for detecting a rotational movement of the gear within the gear train; and

means for computing a rotational movement of a pinion coupled to the gear train based on the rotational movement of the gear within the gear train.

20. The apparatus of claim 19, further comprising means for reflecting a modulated light signal from the surface of the gear within the gear train.