EXTERNAL MICROCONTROLLER FOR LED LIGHTING FIXTURE, LED LIGHTING FIXTURE WITH INTERNAL CONTROLLER, AND LED LIGHTING SYSTEM

• US 20100002223A1
• Filed: 11/13/2007
• Published: 01/07/2010
• Est. Priority Date: 11/17/2006
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Presura, Cristian, Lucassen, Gerhardus Wilhelmus, Laubscher, Markus, Garcia Molina, Gary Nelson
• Application Number:
  US12/513,921
• Publication Number:
  US 20100002223A1
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01B 9/02092 Self-mixing interferometers, i.e. feedback of light from object into laser cavity

Abstract

A detector (210, 310) that is configured to detect ghost-coherent reflections (260) produced by a superluminescent diode (SLD). The ghost reflections (260) are detected based on the optical coherence produced by reflections from surfaces (350, 450, 555) that are at integer multiples of the reflections within the SLD cavity (213), and thus exhibit the fine resolution discrimination that is typical of optical coherent detectors. In a preferred embodiment, the detector (210, 310) is configured to detect ghost reflections (260) from a surface at a particular multiple of the internal reflections. Ghost reflections (260) at other multiples are optically attenuated (330), or, if such reflections are known to be non-varying, canceled via a calibration procedure.

Claims

1. An optical detector (210, 310) comprising:

a laser diode (114) that is configured to project light,

a cavity (213) that is configured to;

provide internal reflections of the light,

emit a beam of the light, and

receive external reflections of the light, and

a detector (115) that is configured to provide an output signal corresponding to the internal and external reflections, and

a lens system (330) that is configured to provide a focal point (351) at a target distance (260), such that external reflections from the target distance (260) are coherent with one or more of the internal reflections.

2. The optical detector (210, 310) of claim 1, wherein

the lens system (330) includes a depth of field that includes multiple target distances (260), reflections from which distances are also coherent with one or more of the internal reflections.

3. The optical detector (210, 310) of claim 1, including:

a processor (340, 440) that is configured to receive the output signal from the detector (115) and to determine therefrom one or more parameters associated with an intended target.

4. The optical detector (210, 310) of claim 3, wherein

the one or more parameters include at least one of:

a presence of the intended target at the target distance (260),

a movement of the intended target from the target distance (260), and

a velocity of the intended target at the target distance (260).

5. The optical detector (210, 310) of claim 3, including

an actuator (440) that is configured to control placement of the intended target relative to the cavity (213).

6. The optical detector (210, 310) of claim 5, wherein

the actuator (440) is configured to control the placement based on the one or more parameters.

7. The optical detector (210, 310) of claim 1, wherein

the laser diode (114) and cavity (213) are configured to form a superluminescent laser diode (SLD).

8. The optical detector (210, 310) of claim 1, wherein

the cavity (213) includes an exit end through which the beam of light is emitted,

the exit end includes a surface (112) having a reflection coefficient that is below a threshold coefficient that provides a laser mode of emission.

9. The optical detector (210, 310) of claim 8, wherein

the reflection coefficient is within a range of 75-95% of the threshold coefficient.

10. A system comprising:

a support structure (301),

an optical detection device (310), and

a target object (350, 450, 555),

wherein

the optical detection device (310) is configured to be located on the support structure (301) at a target distance (260) from the target object (350, 450, 555), and

the target distance (260) substantially corresponds to one of a plurality of ghost-coherent distances associated with coherent internal reflections within the optical detection device (310).

11. The system of claim 10, including

one or more adjustment devices that are configured to facilitate locating the optical detection device (310) at the target distance (260).

12. The system of claim 10, including

a processor (340, 440) that is configured to receive an output from the optical detection device (310) and to provide therefrom one or more parameters associated with the target object (350, 450, 555).

13. The system of claim 12, wherein

the one or more parameters include at least one of:

a presence of the target object (350, 450, 555) at the target distance (260),

a movement of the target object (350, 450, 555) from the target distance (260), and

a velocity of the target object (350, 450, 555) at the target distance (260).

14. The system of claim 12, wherein

the target object (350, 450, 555) includes a spinning object (350) and the one or more parameters include a rotation speed.

15. The system of claim 12, wherein

the target object (350, 450, 555) includes a media on a transport surface (450), and

the processor (340, 440) is configured to detect a speed of transport of the media.

16. The system of claim 12, wherein

the processor (340, 440) is configured to control a location (421) of the target object (350, 450, 555) relative to the support structure (301).

17. The system of claim 12, wherein

the target object (350, 450, 555) includes a conduit (550), and the one or more parameters include a measure of fluid (555) flow through the conduit.

18. The system of claim 10, including

a lens system (330) that is configured to provide a focus (351) of the optical detection device (310) at the target distance (260).

19. The system of claim 18, wherein

the lens system (330) provides a depth of field that spans a predetermined number of ghost-coherent distances (260, 555, 556).

20. The system of claim 10, wherein

the optical detection device (310) includes a superluminescent laser diode (SLD).

21. The system of claim 20, wherein

the superluminescent laser diode includes a cavity (213) that includes an exit end through which light is emitted,

the exit end includes a surface (112) having a reflection coefficient that is within a range of 75-95% of a threshold coefficient that provides a laser mode of emission.

22. A method of optical detection comprising:

determining one or more ghost-coherent distances (260) from a superluminescent laser diode (210, 310) from which reflections are coherent with internal reflections within a cavity (213) of the superluminescent laser diode (210, 310),

affixing the superluminescent laser diode (210, 310) on a supporting structure (301) such that a target point (351) is coincident with one of the ghost-coherent distances (260), and

determining one or more parameters associated with an object (350, 450, 555) at the target point (351).

23. The method of claim 22, wherein

the one or more parameters include at least one of:

a presence of the object at the target distance (260),

a movement of the object from the target distance (260), and

a velocity of the object at the target distance (260).