Illumination setting method, light sheet microscope apparatus, and recording medium

1. An illumination setting method comprising:

acquiring an image of a sample onto which a light sheet emitted from an illumination optical system has been radiated;

determining, based on the acquired image of the sample, a subordinate ray angle with respect to a width direction of the light sheet emitted from the illumination optical system, wherein the subordinate ray angle is a maximum angle formed by an optical axis on an exit side of the illumination optical system, and the subordinate ray angle with respect to the width direction is in a cross-section that includes the width direction and a traveling direction of the light sheet; and

performing a setting of the illumination optical system according to the determined subordinate ray angle.

2. The illumination setting method according to claim 1 , wherein the acquiring of the image of the sample includes:

scanning the sample with the light sheet emitted from the illumination optical system in the width direction of the light sheet, and

capturing, by an imaging device, the image of the sample onto which the light sheet emitted from the illumination optical system has been radiated.

3. The illumination setting method according to claim 2 , wherein the scanning includes moving the light sheet in a parallel fashion in the width direction while maintaining a direction of a principal ray of the light sheet.

4. The illumination setting method according to claim 1 , wherein the determining of the subordinate ray angle includes:

calculating, based on the acquired image of the sample, a width of a stripe that appears in the image of the sample, and

determining the subordinate ray angle based on the calculated width of the stripe.

5. The illumination setting method according to claim 4 , wherein the determining of the subordinate ray angle further includes identifying the stripe that appears in the acquired image of the sample before calculating the width of the stripe.

6. The illumination setting method according to claim 5 , wherein the identifying of the stripe includes identifying, based on the image of the sample, an area in which an intensity of an image signal is not greater than a predetermined value, and identifying the stripe based on the identified area.

7. The illumination setting method according to claim 5 , wherein the identifying of the stripe includes comparing a plurality of images of the sample onto which light sheets with different predetermined subordinate ray angles have been radiated, and identifying the stripe based on a result of comparing the plurality of images.

8. The illumination setting method according to claim 5 , wherein the identifying of the stripe includes performing pattern matching processing on the image of the sample.

9. The illumination setting method according to claim 5 , further comprising, displaying, on a display device, a position of the identified stripe.

10. The illumination setting method according to claim 4 , wherein the subordinate ray angle is calculated based on the calculated width of the stripe and an acceptable length of the stripe.

11. The illumination setting method according to claim 1 , wherein:

the acquiring of the image of the sample includes acquiring a plurality of images of the sample,

each of the plurality of images is an image of the sample onto which a light sheet with a different subordinate ray angle has been radiated,

the determining of the subordinate ray angle includes comparing the acquired plurality of images, and

the subordinate ray angle is determined based on a result of comparing the plurality of images.

12. The illumination setting method according to claim 11 , wherein:

the determining of the subordinate ray angle further includes identifying a stripe that appears in each of the plurality of images of the sample before comparing the plurality of images,

the comparing of the plurality of images includes comparing small regions, in the plurality of images, that each include the identified stripe, and

the subordinate ray angle is determined based on a result of comparing the small regions in the plurality of images.

13. An illumination setting method comprising:

acquiring, by a computer and from an imaging device, an image of a sample onto which a light sheet has been radiated by an illumination optical system;

determining, by the computer and based on the image of the sample that has been acquired from the imaging device, a subordinate ray angle with respect to a width direction of the light sheet emitted from the illumination optical system, wherein the subordinate ray angle is a maximum angle formed by an optical axis on an exit side of the illumination optical system, and the subordinate ray angle with respect to the width direction is in a cross-section that includes the width direction and a traveling direction of the light sheet; and

outputting, by the computer, a control signal that gives an instruction to perform a setting of the illumination optical system that corresponds to the determined subordinate ray angle.

14. A light sheet microscope apparatus comprising:

an illumination optical system that radiates a light sheet onto a sample;

an imaging device that acquires an image of the sample onto which the light sheet has been radiated by the illumination optical system;

a controller that determines, based on the image of the sample that has been acquired by the imaging device, a subordinate ray angle with respect to a width direction of the light sheet emitted from the illumination optical system, wherein the subordinate ray angle is a maximum angle formed by an optical axis on an exit side of the illumination optical system, and the subordinate ray angle with respect to the width direction is in a cross-section that includes the width direction and a traveling direction of the light sheet; and

a setting device that performs a setting of the illumination optical system according to the subordinate ray angle determined by the controller.

15. The light sheet microscope apparatus according to claim 14 , wherein the illumination optical system includes:

a scanner that scans the sample with the light sheet in the width direction of the light sheet, and

a scanning optical system that is arranged such that the scanner is situated at a front focal position of the scanning optical system in the width direction of the light sheet and that radiates light deflected by the scanner onto the sample.

16. The light sheet microscope apparatus according to claim 14 , wherein the controller includes a circuit, and the circuit is configured to:

calculate, based on the image of the sample that has been acquired by the imaging device, a width of a stripe that appears in the image of the sample,

determine the subordinate ray angle based on the calculated width of the stripe, and

output, to the setting device, a control signal that gives an instruction to perform a setting of the illumination optical system that corresponds to the determined subordinate ray angle.

17. The light sheet microscope apparatus according to claim 14 , wherein the controller includes a circuit, and the circuit is configured to:

compare a plurality of images of the sample that have been acquired by the imaging device, each of the plurality of images being an image of the sample onto which a light sheet with a different subordinate ray angle has been radiated,

determine the subordinate ray angle based on a result of the comparison, and

output, to the setting device, a control signal that gives an instruction to perform a setting of the illumination optical system that corresponds to the determined subordinate ray angle.

18. A non-transitory recording medium having stored therein a program that causes a computer to execute a process comprising:

acquiring, from an imaging device, an image of a sample onto which a light sheet has been radiated by an illumination optical system;

determining, based on the image of the sample that has been acquired from the imaging device, a subordinate ray angle with respect to a width direction of the light sheet emitted from the illumination optical system, wherein the subordinate ray angle is a maximum angle formed by an optical axis on an exit side of the illumination optical system, and the subordinate ray angle with respect to the width direction is in a cross-section that includes the width direction and a traveling direction of the light sheet; and

outputting a control signal that gives an instruction to perform a setting of the illumination optical system that corresponds to the determined subordinate ray angle.