Optoelectronic Device for Determining Relative Movements or Relative Positions of Two Objects

• US 20100171704A1
• Filed: 04/05/2007
• Published: 07/08/2010
• Est. Priority Date: 04/05/2006
• Status: Active Grant

• Current Assignee: Societe Civile Galileo 2011
• Original Assignee: Societe Civile Galileo 2011
• Inventors: Pascucci, Antonio, Senft, Volker
• Granted Patent: US 8,243,024 B2
• Time in Patent Office: Days
• US Class Current: 345/168
• CPC Class Codes: G01D 2205/95 Three-dimensional encoders, i.e. having codes extending in three directions
• CPC Class Codes: G01D 5/34 the beams of light being detected by photocells
• CPC Class Codes: G01L 5/166 using photoelectric means
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

The present invention relates to an optoelectronic device for determining relative movements or relative positions of two objects, comprising a first object fixed relative to a frame of the device; a second object mounted in spaced relation to the first object and adapted for movement relative thereto; and a plurality of measuring cells for determining movement or displacement of the second object relative to the first object. Each measuring cell comprises a light-emitting element and a detector for detecting light from the light-emitting element. The invention provides a light shield for the optoelectronic device, the light shield comprising a plurality of channels which together define a non-planar or three-dimensional array of light beam paths between the first and second objects of the optoelectronic device.

Claims

1. A light shield for an optoelectronic device which determines relative movements or relative positions of two objects, the light shield comprising a plurality of channels, each of which forms a path for a light beam between a light-emitting element and a detector of the optoelectronic device, wherein characterized in that the light shield has a generally hollow structure with a number of cavities that form individual light path channels between each light-emitting element and its respective detector, and in that at least two of said channels define light paths which converge with one another from the light-emitting elements to the respective detector.

2. A light shield according to claim 1, wherein the plurality of light-path channels are arranged in one or more group of at least two and define separate light paths which converge towards a common detector.

6. A light shield according to claim 1, wherein the channels are formed by wall portions of the light shield and wherein each channel at least partially surrounds or encloses the light path to define a cavity along which the light is directed or guided between a light-emitting element and a detector of the optoelectronic device.

7. A light shield according to claim 6, wherein the light shield is adapted to at least partially enclose or house light-emitting elements of the optoelectronic device.

8. A light shield according to claim 6, further comprising one or more slit diaphragm the wall portions enclosing the channels.

9. A light shield according to claim 1, wherein the light-path channels define light paths that are inclined at an angle relative to a reference plane corresponding to a plane of the frame of the device, and/or to a plane of the first object.

10. A light shield according to claim 9, wherein the light-path channels define light beam paths which are inclined at an angle between 0°

and 90°

relative to the reference plane, preferably at an angle in the range of 0°

to 60°

, and more preferably at an angle in the range of 10°

to 30°

.

11. A light shield according to claim 1, wherein the light shield is formed as a unitary or integral component.

12. A light shield according to claim 1, further comprising a space or cavity adapted to receive a stop arrangement or at least one stop member of the optoelectronic device.

13. A light shield according to claim 12, wherein wall portions of the light shield defining the space or cavity are adapted to contact the stop arrangement the at least one stop member at a limit of relative movement between the first object and the second object.

14. A light shield according to claim 12, wherein the light path channels are arranged around the space or cavity for receiving the stop arrangement or the at least one stop member.

15. A light shield according to claim 1, wherein the light shield is adapted to be mounted to one of the first object and the second object.

16. An optoelectronic device for determining relative movements or relative positions of two objects, comprising:

a first object fixed relative to a frame of the device;

a second object mounted in spaced relation to the first object and adapted for movement relative thereto;

a plurality of measuring cells for determining movement or displacement of the second object relative to the first object, each measuring cell comprising a light-emitting element and a detector for detecting light from the light-emitting element; and

a light shield according to any one of the preceding claims mounted between the first object and the second object, wherein each light-path channel of the light shield extends at least part of the distance between a light-emitting element and a detector of one of the measuring cells.

17. An optoelectronic device according to claim 16, wherein each measuring cell further includes a slit diaphragm arranged in the light path between the position-sensitive detector and the light-emitting element, and wherein the light shield incorporates said slit diaphragm in a side or wall portion thereof.

18. An optoelectronic device according to claim 17, wherein each light-path channel defined by the light shield extends between a light-emitting element and an associated slit diaphragm.

19. An optoelectronic device to claim 16, wherein at least one detector is illuminated by two separate light-emitting elements to thereby form two measuring cells with a common detector, and wherein the light shield defines separate light path channels extending between the separate light-emitting elements and the common position-sensitive detector.

20. An optoelectronic device according to claim 19, wherein each of said two measuring cells with the common detector has a separate slit diaphragm arranged in the beam path of the corresponding light-emitting element, said separate slit diaphragms being arranged adjacent one another, preferably in parallel, in a side or wall portion of the light shield.

21. An optoelectronic device according to claim 19, wherein each detector that is illuminated by more than one light-emitting element to form multiple measuring cells is illuminated alternately (i.e. periodically) by the light-emitting elements.

22. An optoelectronic device according to claim 16, wherein a stop arrangement or at least one stop member is received within a space or cavity of the light shield for limiting movement of the second object relative to the first object.

23. An optoelectronic device according to claim 22, wherein wall portions of the light shield defining the space or cavity are adapted to contact the stop arrangement or the at least one stop member at a limit of relative movement between the first object and the second object.

24. An optoelectronic device according to claim 22, wherein the light path channels in the light shield are arranged around the space or cavity for receiving the stop arrangement or stop member.

25. A force and/or moment sensor incorporating an optoelectronic device according to a claim 16.

26. A keyboard for a personal computer incorporating an optoelectronic device according to claim 16.

3. A light shield for an optoelectronic device for determining a position or movement of a second object relative to a first object, wherein the light shield comprises a number of cavities that define a plurality of channels, forming light-beam paths from the first object to he second object, wherein the plurality of channels together define a non-planar or three-dimensional array of light beam paths between the first and second objects of the optoelectronic device.

4. A light shield according to claim 3, wherein the plurality of channels are arranged such that the light paths defined by the channels extend in separate planes between the first and second objects, and preferably planes which intersect with one another.

5. A light shield for an optoelectronic device for determining a position or movement of a second object relative to a first object, the second object being substantially flat and mounted in substantially parallel spaced relation to the first object, wherein the light shield is adapted to be mounted between the first object and the second object and comprises a plurality of channels, each of which forms a light beam path adapted to extend between the first object and the second object.