Observation apparatus and observation method to observe a sample with reflected light transmitted through the sample

1. An observation apparatus comprising:

a light-source unit that is configured to be positioned at a first side of a sample, and to emit illumination light; and

an image-capturing optical system that is configured to be positioned at the first side of the sample, and to capture transmitted light, which is the illumination light that has been emitted from the light-source unit, reflected at a second side of the sample that is opposite from the first side, and passed through the sample,

wherein the image-capturing optical system comprises an objective lens that is configured to collect the transmitted light that has passed through the sample,

wherein the light-source unit is configured to emit the illumination light from a position radially outward from the objective lens, toward an area at the second side of the sample,

wherein the light-source unit is configured to emit the illumination light to the second side of the sample such that the emitted illumination light does not pass through an area of a field of view of the sample of the image-capturing optical system, and

wherein the illumination light that is reflected at the second side of the sample passes through the area of the field of view of the sample of the image-capturing optical system as the transmitted light.

2. An observation apparatus according to claim 1 , wherein the light-source unit is capable of independently emitting the illumination light from different positions in radial directions of the objective lens.

3. An observation apparatus according to claim 2 , wherein the light-source unit comprises a plurality of light sources that are arranged in an area surrounding the objective lens and that can independently be turned on.

4. An observation apparatus according to claim 1 , wherein the light-source unit is capable of simultaneously emitting the illumination light from different positions in a circumferential direction of the objective lens.

5. An observation apparatus according to claim 1 , wherein the light-source unit comprises a light source that is disposed at the first side of the sample and a light-blocking member that has an opening that allows, of the illumination light coming from the light source, only the illumination light at a specific radial-direction position to pass therethrough.

6. An observation apparatus according to claim 1 , wherein the light-source unit comprises a diffuser panel that diffuses the illumination light.

7. An observation apparatus according to claim 1 , wherein:

the sample is accommodated in a container formed of an optically transparent material, and

the illumination light is reflected by an inner surface of a top plate of the container, which is disposed above the sample.

8. An observation apparatus according to claim 1 , wherein the illumination light is reflected by a reflecting member disposed at the second side of the sample.

9. An observation apparatus according to claim 1 , wherein:

the sample is immersed in a solution, and

the illumination light is reflected by a liquid surface at a top of the solution.

10. An observation apparatus according to claim 1 , wherein the light-source unit is capable of independently emitting the illumination light from different positions in a circumferential direction of the objective lens.

11. An observation apparatus according to claim 1 , wherein the light-source unit is capable of changing between a first state in which the illumination light is emitted from a first position in a circumferential direction of the objective lens, and a second state in which the illumination light is emitted from a second position in a circumferential direction of the objective lens, the second position being different from the first position.

12. An observation method comprising:

emitting illumination light from a first side of a sample;

reflecting the emitted illumination light, at a second side of the sample that is opposite from the first side;

allowing the reflected illumination light to pass through the sample; and

at the second side of the sample, collecting transmitted light that has passed through the sample with an objective lens, and capturing an image of the transmitted light collected by the objective lens,

wherein the illumination light is emitted from a position radially outward from the objective lens, toward an area at the second side of the sample,

wherein the illumination light is emitted to the second side of the sample such that the emitted illumination light does not pass through an area of a field of view of the sample of the objective lens, and

wherein the illumination light that is reflected at the second side of the sample passes through the area of the field of view of the sample of the image-capturing optical system as the transmitted light.

13. An observation apparatus comprising:

a light-source unit that is configured to be positioned at a first side of a sample, and to emit illumination light; and

an image-capturing optical system that is configured to be positioned at the first side of the sample, and to capture transmitted light, which is the illumination light that has been emitted from the light-source unit, reflected at a second side of the sample that is opposite from the first side, and passed through the sample,

wherein the image-capturing optical system comprises an objective lens that is configured to collect the transmitted light that has passed through the sample,

wherein the light-source unit is configured to emit the illumination light from a position radially outward from the objective lens, toward an area at the second side of the sample, and

wherein the light-source unit is capable of independently emitting the illumination light from different positions in radial directions of the objective lens.

14. An observation apparatus according to claim 13 , wherein the light-source unit comprises a plurality of light sources that are arranged in an area surrounding the objective lens and that can independently be turned on.

15. An observation apparatus comprising:

a light-source unit that is configured to be positioned at a first side of a sample, and to emit illumination light; and

an image-capturing optical system that is configured to be positioned at the first side of the sample, and to capture transmitted light, which is the illumination light that has been emitted from the light-source unit, reflected at a second side of the sample that is opposite from the first side, and passed through the sample,

wherein the image-capturing optical system comprises an objective lens that is configured to collect the transmitted light that has passed through the sample,

wherein the light-source unit is configured to emit the illumination light from a position radially outward from the objective lens, toward an area at the second side of the sample, and

wherein the light-source unit is capable of simultaneously emitting the illumination light from different positions in a circumferential direction of the objective lens.

16. An observation apparatus comprising:

a light-source unit that is configured to be positioned at a first side of a sample, and to emit illumination light; and

an image-capturing optical system that is configured to be positioned at the first side of the sample, and to capture transmitted light, which is the illumination light that has been emitted from the light-source unit, reflected at a second side of the sample that is opposite from the first side, and passed through the sample,

wherein the image-capturing optical system comprises an objective lens that is configured to collect the transmitted light that has passed through the sample,

wherein the light-source unit is configured to emit the illumination light from a position radially outward from the objective lens, toward an area at the second side of the sample, and

wherein the light-source unit comprises a light source that is disposed at the first side of the sample and a light-blocking member that has an opening that allows, of the illumination light coming from the light source, only the illumination light at a specific radial-direction position to pass therethrough.

17. An observation apparatus comprising:

a light-source unit that is configured to emit illumination light upward from below a sample; and

an image-capturing optical system that is configured to capture transmitted light below the sample, wherein the transmitted light is the illumination light that has been emitted from the light-source unit, reflected above the sample, and passed through the sample,

wherein:

the sample is immersed in a solution, and

the illumination light is reflected by a liquid surface at a top of the solution.