Cytometer having telecentric optics

• US 20060066840A1
• Filed: 09/28/2004
• Published: 03/30/2006
• Est. Priority Date: 08/21/2002
• Status: Active Grant

• Current Assignee: Bernard S. Fritz
• Original Assignee: Honeywell International Inc.
• Inventors: Fritz, Bernard S.
• Granted Patent: US 7,283,223 B2
• Time in Patent Office: Days
• US Class Current: 356/121
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/1452 Adjustment of focus; Alignment

Abstract

A mechanism for moving and positioning a light source so that its light impinges a target as it moves on or off axis of an optical system. A detector may receive scattered light at a same position whether the light impinging the target is on or off axis due to, for example, a telecentric optical system. Further, the light may be positioned so that the detector is maximally impinged with scattered light. An output may go to a processor that sends a signal to the light source to move the emitted light so as to continually impinge the target as it moves on or off axis. An array of light sources may used in lieu of the moving light source. To move the light beam, another light at another position in the array may be selected to replace a previously selected light source.

Claims

1. An illumination apparatus comprising:

a light source;

an optical system, having an axis, at least partially situated between the light source and a target; and

a detector situated on the axis and proximate to the target; and

wherein;

the target may move on axis or off axis;

the light source may provide a light beam that is moveable to illuminate the target on axis or off axis;

light from the light beam may be mapped to a first position on the detector when the light source is on axis;

light from the light beam may be mapped to a second position on the detector when the light source is off axis; and

the second position is equivalent to the first position.

2. The apparatus of claim 1, wherein the optical system comprises:

a first lens between the light source and the target; and

an aperture situated between the first lens and the target.

3. The apparatus of claim 2, wherein the optical system further comprises a second lens situated between the aperture and the target.

4. The apparatus of claim 3, wherein the optical system further comprises a third lens situated between the target and the detector.

5. The apparatus of claim 4, wherein:

the light source is situated substantially at a focal point of the first lens;

the aperture is situated substantially at a focal point of the first lens and a focal point of the second lens;

the target is situated substantially at a focal point of the second lens and a focal point of the third lens; and

the detector is situated substantially at a focal point of the third lens.

6. The apparatus of claim 1, wherein at least some of the light mapped on the first position and the second position of the detector is light scattered by the target.

7. The apparatus of claim 1, further comprising:

a mechanism connected to the light source to provide various positions of the light source that may move the light beam; and

a processor connected to the detector and the mechanism.

8. The apparatus of claim 7, wherein a signal from the detector via the processor indicates a position to be selected of the various positions of the light source to maximally impact the detector with light.

9. The apparatus of claim 1, wherein the light source is an array of a plurality of lights that are individually selectable to move the light beam.

10. The apparatus of claim 9, further comprising a processor connected to the detector and the mechanism.

11. The apparatus of claim 10, wherein a signal from the detector via the processor indicates a light to be selected of the array of the plurality of lights to maximally impact the detector with light.

12. A telecentric light source position aligner system, comprising:

a light source, moveable for various positions, situated proximate to a channel;

a detector having the channel situated between the detector and the light source; and

a processor connected to the light source and the detector.

13. The system of claim 12, wherein:

the light source has an optical path from the light source through the channel; and

the light path is from the channel to a specific location on the detector.

14. The system of claim 13, wherein for the various positions of the light source, the light path from the light source at each of the various positions is to the specific location on the detector.

15. The system of claim 12, wherein:

the light source emanates light;

the light impinges the channel; and

some of the light becomes scattered light; and

the detector detects the scattered light.

16. The system of claim 15, wherein:

the amount of scattered light varies with the an alignment of the incident light with a core stream within the channel of a cytometer; and

a varying position of the light source varies the alignment of the incident light with the core stream.

17. The system of claim 16, wherein a varying position of the light source does not vary the location of impingement of light on the detector from the light source.

18. The system of claim 16, wherein:

the detector converts detected scattered light into an electrical signal;

the electrical signal goes to the processor; and

the processor sends a signal to the light source to adjust a position of the light source to optimize the electrical signal from the detector.

19. The system of claim 18, wherein light on the detector from the light source has a cone angle and orientation that remains the same.

20. A light beam alignment system comprising:

a detector proximate to a channel; and

a light source having an alignment adjuster relative to the channel; and

wherein the alignment adjuster provides a projection of the light source on a moveable target in the channel without affecting a projection of the light source relative to the detector.

21. The system of claim 20, wherein the alignment adjuster comprises an optical structure for focusing the light source on the moveable target in the channel and at a consistent location on the detector;

22. The system of claim 21, wherein light from the light source to the detector has a cone angle and orientation that remains the same.

23. The system of claim 21, wherein:

the detector is connected to a processor; and

the processor is connected to the alignment adjuster.

24. The system of claim 23, wherein:

light from the light source may impinge the target;

the target may scatter the light that may impinge the target;

the detector may convert the scattered light into a first electrical signal; and

the processor may measure an amplitude of the first electrical signal and send a second electrical signal to the alignment adjuster to provide the projection of the light source on a moveable target in the channel.

25. The system of claim 24, wherein the amplitude of the first electrical signal from the detector may indicate an amount of projection of the light source relative to the target.

26. The system of claim 25, wherein:

the greater the amplitude of the first electrical signal, the projection of the light source is closer to the target; and

the lesser of the amplitude of the first electrical signal, the projection of the light source is farther from the target.

27. The system of claim 26, wherein the target is in a core stream in the channel of a cytometer.

28. The system of claim 27, wherein the core stream has a location that may change within the channel.

29. A means for alignment comprising:

means for providing a light beam having a direction;

means for adjusting the direction of the light beam;

means for providing a target;

means for measuring the amount of light scattered by the target; and

wherein the direction of the light beam is adjusted to increase the amount of light scattered by the target.

30. The means of claim 29, wherein:

the light scattered by the target is mapped to a first position of the means for measuring the amount of light scattered by the target; and

upon an adjustment of the direction of the light beam, the light scattered by the target remains mapped to the first position of the means for measuring the amount of light scattered by the target.

31. The means of claim 30, wherein the target is a core stream in a flow channel of a cytometer.

32. A method for alignment of a light beam with a core stream in a flow channel of a cytometer, comprising:

directing a light beam towards the flow channel;

measuring an amount of light scattered by the core stream in the flow channel; and

adjusting the direction of the light beam towards the core stream to change the amount of light scattered by the flow stream.

33. The method of claim 32, wherein the direction of the light beam towards the core stream is adjusted to maximize the amount of light scattered by the flow stream.

34. The method of claim 33, wherein the direction of the light beam is adjusted with a change of position of a light source relative to the core stream.

35. The method of claim 34, wherein light on the core stream from the light source has a cone angle and orientation that remains the same.

36. The method of claim 35, wherein:

the light source comprises a plurality of lights; and

the change of position of the light source is effected by a selection of a light from the plurality of lights.

37. The method of claim 36, wherein the measuring an amount of light scattered by the core stream is effected by a detector.

38. The method of claim 37, wherein the scattered light is continually mapped to a same position on the detector when the change of position of the light source is effected.

39. A telecentricity apparatus comprising:

a light source having various positions;

a detector having a target situated between the light source and the detector; and

an optical arrangement situated between the light source and the detector; and

wherein the optical arrangement maintains the same impact position of a light beam from the light source on the detector for the various positions the light source.

40. The apparatus of claim 39, wherein a position of the various positions of the light source is selected to maximally impinge the target with the light beam.

41. The apparatus of claim 40, further comprising:

a processor connected to the detector and the light source; and

wherein a signal from the detector via the processor indicates a position to be selected of the various positions of the light source to maximally impinge the target with the light beam.

42. The apparatus of claim 41, wherein the target is a core stream in a flow channel.

43. The apparatus of claim 42, wherein the flow channel is of a cytometer.