Systems and methods for focusing optics

• US 20080151263A1
• Filed: 08/24/2007
• Published: 06/26/2008
• Est. Priority Date: 08/25/2006
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Brenner, David J., Randers-Pehrson, Gerhard, Garty, Guy
• Granted Patent: US 7,898,673 B2
• Time in Patent Office: Days
• US Class Current: 356/601
• CPC Class Codes: C40B 30/10 by measuring physical properties, e.g. mass
• CPC Class Codes: C40B 60/12 for screening libraries

Abstract

Systems and methods for focusing optics are disclosed herein. In some embodiments, methods are disclosed for focusing an optical device, wherein the methods can include: collecting light from a region of an object to be imaged with an objective lens, said region having a feature with a known geometric characteristic; splitting the collected light into a first portion and a second portion, and directing said first portion through a weak cylindrical lens to a focusing sensor, and directing said second portion to an imager; observing, with said focusing sensor, a shape of the feature; focusing the optical device by moving at least one of the objective lens and the object to be imaged until the observed shape of the feature has a predetermined relationship to the known geometric characteristic. In some embodiments, the feature can be a fluorescent bead. In some embodiments, the splitting step can be accomplished with a dichroic mirror. In other embodiments, the splitting step can be accomplished with a partial mirror. In some embodiments, the known geometric characteristic of the feature can be substantially spherical, the observed shape can be an oval, and the predetermined relationship can be an allowable aspect ratio of the oval. In some embodiments, the allowable aspect ratio can be approximately one.

Claims

1. A method for focusing an optical device, comprising:

(a) collecting light from a region of an object to be imaged with an objective lens, said region having a feature with a known geometric characteristic;

(b) splitting the collected light into a first portion and a second portion, and directing said first portion through a weak cylindrical lens to a focusing sensor, and directing said second portion to an imager;

(c) observing, with said focusing sensor, a shape of the feature;

(d) focusing the optical device by moving at least one of the objective lens and the object to be imaged until the observed shape of the feature has a predetermined relationship to the known geometric characteristic.

2. The method of claim 1, wherein the feature is a fluorescent bead.

3. The method of claim 2, wherein the splitting step is accomplished with a dichroic mirror.

4. The method of claim 2, wherein the splitting step is accomplished with a partial mirror.

5. The method of claim 1, wherein the known geometric characteristic of the feature is substantially spherical, the observed shape is an oval, and the predetermined relationship is an allowable aspect ratio of the oval.

6. The method of claim 5, wherein the allowable aspect ratio is approximately one.

7. The method of claim 1, wherein at least one of the focusing sensor and imager produce a digital image.

8. The method of claim 7, wherein the digital image is captured using a CMOS chip.

9. The method of claim 7, wherein the digital image is captured using a CCD chip.

10. The method of claim 7, wherein the digital image is compared to a stored digital image to determine whether the observed shape of the feature has the predetermined relationship to the known geometric characteristic.

11. The method of claim 7, wherein the digital image is compared to a theoretical model to determine whether the observed shape of the feature has the predetermined relationship to the known geometric characteristic.

12. The method of claim 11, wherein the comparison is performed using a processor.

13. The method of claim 11, wherein the comparison is performed using a field-programmable gate array (FPGA).

14. An apparatus for focusing an optical device, comprising:

(a) an objective lens for collecting light from a region of an object to be imaged through an objective lens, said region having a feature with a known geometric characteristic;

(b) means for splitting the collected light into a first portion and a second portion, and directing said first portion through a weak cylindrical lens to a focusing sensor, and directing said second portion to an imager;

(c) a focusing sensor for observing a shape of the feature;

(d) a mechanism for focusing the optical device by moving at least one of the objective lens and the object to be imaged; and

(e) a processor for analyzing the observed shape and determining whether the observed shape of the feature has a predetermined relationship to the known geometric characteristic.

15. The apparatus of claim 14, wherein the collected light is at least one of

a. light reflecting from the region as a result of incident light from a laser source;

and

b. light emitted from a fluorescent bead.

16. The apparatus of claim 14, wherein the optical device is a microscope.

17. The apparatus of claim 14, wherein the splitting means is a dichroic mirror

18. The apparatus of claim 14, wherein the splitting means is a partial mirror.

19. The apparatus of claim 14, wherein the known geometric characteristic of the feature is substantially spherical, the observed shape is an oval, and the predetermined relationship is an allowable aspect ratio of the oval.

20. The apparatus of claim 19, wherein the allowable aspect ratio is approximately one.

21. The apparatus of claim 14, wherein at least one of the focusing sensor and imager produce a digital image.

22. The apparatus of claim 21, wherein the digital image is captured using a CMOS chip.

23. The apparatus of claim 21, wherein the digital image is captured using a CCD chip.

24. The apparatus of claim 21, wherein the digital image is compared to a stored digital image to determine whether the observed shape of the feature has the predetermined relationship to the known geometric characteristic.

25. The apparatus of claim 24, wherein the comparison is performed using the processor.

26. The apparatus of claim 24, wherein the comparison is performed using a field-programmable gate array (FPGA).

27. The apparatus of claim 14, wherein the mechanism is at least one of a motor and a piezoelectric device

28. The apparatus of claim 27, wherein the processor is coupled to the mechanism and the processor is adapted to control the mechanism.

29. The apparatus of claim 28, wherein the processor directs the mechanism to adjust at least one of the imaging element and an object to be imaged until the observed shape has the predetermined relationship to the known geometric characteristic.

30. The apparatus of claim 29, wherein the processor predicts an appropriate final position of at least one of the imaging element and the object to be imaged prior to directing the mechanism.

31. A system for focusing an optical device, comprising:

(a) a light collecting means for collecting light from a region of an object to be imaged with an objective lens, said region having a feature with a known geometric characteristic;

(b) a light splitting means for splitting the collected light into a first portion and a second portion, and directing said first portion through a weak cylindrical lens to a focusing sensor, and directing said second portion to an imager;

(c) mechanical means for focusing the optical moving at least one of the objective lens and the object to be imaged until the observed shape of the feature has a predetermined relationship to the known geometric characteristic; and

(d) a processing means, coupled to the mechanical means and focusing sensor, for analyzing the observed shape and determining whether the observed shape of the feature has a predetermined relationship to the known geometric characteristic.