Specimen observation apparatus

1. An observation apparatus comprising:

a top plate on which a container in which a specimen is accommodated can be placed, and through which illumination light can pass;

a light source that emits the illumination light upward from below the specimen;

an objective lens that focuses, below the specimen and the top plate, transmitted light which is the illumination light that has passed through the specimen after being reflected from above the specimen and that has passed through the top plate, a position of the objective lens being fixed such that a relative positional relationship between the objective lens and the top plate remains constant; and

a camera that captures the transmitted light focused by the objective lens,

wherein:

the light source emits the illumination light toward an area above the specimen from outside the objective lens in a radial direction, and

the top plate is provided with a mark that specifies a viewing-field area of the camera.

2. The observation apparatus according to claim 1 , wherein the mark is provided on the top plate itself.

3. The observation apparatus according to claim 1 , wherein:

a sheet member is detachably provided on one surface of the top plate, and

the mark is provided on the sheet member.

4. The observation apparatus according to claim 3 , wherein a plurality of the sheet members are provided, the marks provided on the plurality of sheet members being different from each other in size.

5. The observation apparatus according to claim 1 , further comprising an adaptor that is placed on the top plate and that holds the container.

6. The observation according to claim 5 , wherein the adaptor has a mounting surface on which the container is placed, the mounting surface being at least partially formed of an optically transparent material.

7. The observation apparatus according to claim 5 , wherein the adaptor has a through-hole through which the transmitted light can pass.

8. The observation apparatus according to claim 5 , further comprising a movement restricting portion that restricts relative movement between the adaptor and the top plate.

9. The observation apparatus according to claim 8 , wherein the movement restricting portion comprises an electromagnet that, as a result of being powered on, puts a restriction on the relative movement between the adaptor and the top plate, and that, as a result of being powered off, cancels the restriction on the relative movement between the adaptor and the top plate.

10. The observation apparatus according to claim 1 , wherein the light source is configured to emit the illumination light from different positions in the radial direction of the objective lens.

11. The observation apparatus according to claim 1 , wherein the light source is configured to emit the illumination light from different positions in a circumferential direction of the objective lens.

12. The observation apparatus according to claim 1 , wherein the light source comprises a plurality of light sources that are arrayed in an area surrounding the objective lens and that are configured to be selectively turned on.

13. The observation apparatus according to claim 1 , wherein the light source comprises:

at least one light source that is disposed below the specimen; and

a light-blocking member that has an opening that allows, of illumination light emitted from the at least one light source, only illumination light in a specific radial-direction position to pass therethrough.

14. The observation apparatus according to claim 1 , wherein the light source comprises a diffusion plate that spreads out the illumination light.

15. The observation apparatus according to 1 , further comprising:

a reflecting member that is disposed above the container and that reflects the illumination light emitted from the light source.

16. The observation apparatus according to claim 15 , wherein the reflecting member is retractably provided above the container.

17. The observation apparatus according to claim 1 , further comprising:

a second light source that emits illumination light toward an area below the specimen from above the specimen,

wherein the camera further captures transmitted light which is the illumination light that is emitted from the second light source and that has passed through the specimen and the top plate.

18. The observation apparatus according to claim 17 , wherein the other light source is retractably provided above the container.

19. The observation apparatus according to claim 1 , wherein:

the container is formed of an optically transparent material, and

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

20. The observation apparatus according to claim 1 , wherein:

the specimen is immersed in a solution, and

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

21. The observation apparatus according to claim 1 , wherein the mark specifies a desired-specimen position in the viewing-field area of the camera.

22. The observation apparatus according to claim 1 , further comprising:

a housing having the top plate,

wherein the housing accommodates the light source and the camera.

23. A method for observing a specimen accommodated in a container placed on a top plate through which illumination light can pass, the top plate being provided with a mark, and the method comprising:

emitting the illumination light upward from below the specimen;

focusing, by an objective provided below the specimen and the top plate, transmitted light which is the illumination light that has passed through the specimen after being reflected from above the specimen and that has passed through the top plate;

capturing, by a camera, an image of the transmitted light focused by the objective lens; and

moving the specimen together with the container to a position of the mark to collect the specimen from the container by using the mark as an indicator,

wherein the light source emits the illumination light toward an area above the specimen from a position radially outward of a position at which the transmitted light is focused.