Systems, devices and methods for automatic microscopic focus

Patent metadata

Field	Value
Publication number	US-10509199-B2
Application number	US-201916275177-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Mar 14, 2018
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

An automatic focus system for an optical microscope that facilitates faster focusing by using at least two cameras. The first camera can be positioned in a first image forming conjugate plane and receives light from a first illumination source that transmits light in a first wavelength range. The second camera can be positioned at an offset distance from the first image forming conjugate plane and receives light from a second illumination source that transmits light in a second wavelength range.

First claim

What is claimed is:

1. A system for automatically focusing a microscope, comprising:
a first camera, configured for focusing, positioned on an image forming conjugate plane;
a second camera, configured for focusing, positioned at an offset distance from the image forming conjugate plane; and
a hardware processor coupled to the first camera and the second camera that is configured to:
determine, using the first camera, when a specimen is in focus based on a sharpness value;
determine, using the second camera, a sharpness setpoint for the specimen when the specimen is determined to be in focus for the first camera;
after movement of the specimen, determine, using the second camera, a first sharpness value of the specimen;
determine whether the first sharpness value of the specimen is higher or lower than the sharpness setpoint; and
adjust the microscope so that a second sharpness value of the specimen determined using the second camera corresponds to the sharpness setpoint.

2. The system of claim 1 , wherein the hardware processor is further configured to:
determine a sharpness curve for the specimen using the second camera; and
adjust the microscope based on the sharpness curve so that the second sharpness value of the specimen determined using the second camera corresponds to the sharpness setpoint.

3. The system of claim 1 , further comprising:
a first filter positioned in an optical path between a second illumination source and the first camera to prevent light from the second illumination source from reaching the first camera; and
a second filter positioned in an optical path between a first illumination source and the second camera to prevent light from the first illumination source from reaching the second camera.

4. The system of claim 1 , wherein the first camera is also configured for taking images of the specimen when the specimen is determined to be in focus.

5. The system of claim 1 , further comprising a field diaphragm positioned in an optical path between a primary illumination source and an objective.

6. The system of claim 1 , wherein the hardware processor is further configured adjust the microscope to achieve a coarse focus and a fine focus.

7. The system of claim 1 , wherein adjusting the microscope so that the second sharpness value of the specimen determined using the second camera corresponds to the sharpness setpoint comprises repeatedly:
adjusting the microscope;
determining the second sharpness value using the second camera; and
comparing the second sharpness value to the sharpness setpoint.

8. The system of claim 1 , wherein the hardware processor is further configured to save an adjustment setting of the microscope.

9. The system of claim 8 , wherein the saved adjustment setting is used to determine a position of the second camera relative to the second image forming conjugate plane.

10. A system for automatically focusing a microscope, comprising:
a first camera, configured for taking images of a specimen when the specimen is determined to be in focus, positioned on an image forming conjugate plane;
a second camera, configured for focusing, positioned on a second image forming conjugate plane;
a third camera, configured for focusing, positioned at an offset distance from the second image forming conjugate plane;
a hardware processor coupled to the second camera and the third camera that is configured to:
determine, using the second camera, when the specimen is in focus based on a sharpness value;
determine, using the third camera, a sharpness setpoint for the specimen when the specimen is determined to be in focus for the second camera;
after movement of the specimen, determine, using the third camera, a first sharpness value of the specimen;
determine whether the first sharpness value of the specimen is higher or lower than the sharpness setpoint; and
adjust the microscope so that a second sharpness value of the specimen determined using the third camera corresponds to the sharpness setpoint.

11. The system of claim 10 , wherein the hardware processor is further configured to:
determine a sharpness curve for the specimen using the third camera; and
adjust the microscope based on the sharpness curve so that the second sharpness value of the specimen determined using the third camera corresponds to the sharpness setpoint.

12. The system of claim 10 , further comprising:
a first filter positioned in an optical path between a second illumination source and the first camera to prevent light from the second illumination source from reaching the first camera; and
a second filter positioned in an optical path between a first illumination source and the second and third cameras to prevent light from the first illumination source from reaching the second and third cameras.

13. The system of claim 10 , further comprising a field diaphragm positioned in an optical path between a first illumination source and an objective.

14. The system of claim 10 , wherein the hardware processor is further configured to adjust the microscope to achieve a coarse focus and a fine focus.

15. The system of claim 10 , wherein adjusting the microscope so that the second sharpness value of the specimen determined using the third camera corresponds to the sharpness setpoint comprises repeatedly:
adjusting the microscope;
determining the second sharpness value using the third camera; and
comparing the second sharpness value to the sharpness setpoint.

16. The system of claim 10 , wherein the hardware processor is configured to save an adjustment setting of the microscope.

17. The system of claim 16 , wherein the saved adjustment setting is used to determine a position of the third camera relative to the third image forming conjugate plane.

18. A method for automatically focusing a microscope, comprising:
positioning a first camera, configured for focusing, on an image forming conjugate plane;
positioning a second camera, configured for focusing, at an offset distance from the second image forming conjugate plane;
determining, by a hardware processor using the first camera, when a specimen is in focus based on a sharpness value;
determining, by the hardware processor using the second camera, a sharpness setpoint for the specimen when the specimen is determined to be in focus for the first camera;
after movement of the specimen, determining, by the hardware processor using the second camera, a first sharpness value of the specimen;
determining, by the hardware processor, whether the first sharpness value of the specimen is higher or lower than the sharpness setpoint; and
adjusting, by the hardware processor, the microscope so that a second sharpness value of the specimen determined using the second camera corresponds to the sharpness setpoint.

19. The method of claim 18 , further comprising:
determining a sharpness curve for the specimen using the second camera; and
adjusting the microscope based on the sharpness curve so that the second sharpness value of the specimen determined using the second camera corresponds to the sharpness setpoint.

20. The method of claim 18 , further comprising:
preventing light from a second illumination source from reaching the first camera; and
preventing light from a first illumination source from reaching the second camera.

21. The method of claim 18 , wherein the first camera is also configured for taking images of the specimen when the specimen is determined to be in focus.

22. The met

Assignees

• Nanotronics Imaging Inc

Inventors

• Putman John B
• Putman Matthew C
• Orlando Julie
• Fashbaugh Dylan

Classifications

• G02B21/244 Primary

  using image analysis techniques · CPC title

• G02B21/06 Primary

  Means for illuminating specimens · CPC title

• G02B7/285 Primary

  including two or more different focus detection devices, e.g. both an active and a passive focus detecting device · CPC title

• G06T7/80

  Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration · CPC title

• G02B21/26

  Stages; Adjusting means therefor · CPC title