The microscope comprises a first phase-contrast objective including a first phase film shaped like a ring and having a 20-fold magnification or lower, a second phase-contrast objective including a second phase film shaped like a ring and having a 60-fold magnification or higher; and a ring slit shared and used by the first and second phase-contrast objectives.
1. A microscope comprising:
a first phase-contrast objective which includes a first phase film shaped like a ring and which has a 20-fold magnification or lower;
a second phase-contrast objective which includes a second phase film shaped like a ring and which has a 100-fold magnification or higher; and
a ring slit shared and used by the first and second phase-contrast objectives;
wherein:
the first phase film is placed at a pupil position of the first phase-contrast objective, and changes a phase of a laser beam by ¼ wavelength;
the second phase film is placed at a pupil position of the second phase-contrast objective, and changes a phase of a laser beam by ¼ wavelength;
when the first phase-contrast objective is used, the ring slit is placed at a position conjugate to the first phase film;
when the second phase-contrast objective is used, the ring slit is placed at a position conjugate to the second phase film; and
the following conditional expression is satisfied:
PH OB2 /OB 2 ≦0.15,
where OB 2 indicates a pupil diameter of the second phase-contrast objective and PH OB2 indicates a central diameter of a ring of the second phase film.
2. The microscope according to claim 1 , further comprising a third phase-contrast objective having a magnification which is between a magnification of the first phase-contrast objective and a magnification of the second phase-contrast objective,
wherein the ring slit is shared and used by the first, second and third phase-contrast objectives.
3. The microscope according to claim 1 , further comprising:
a laser light source which emits a laser beam;
a scan unit which scans a specimen surface by the laser beam;
a first detector which detects radiated light from the specimen surface; and
a second detector which detects transmitted light from the specimen surface,
wherein:
the laser beam is incident from an image side of the first and second phase-contrast objectives;
the first detector is used for fluorescence observation; and
the second detector is used for phase-contrast observation.
4. The microscope according to claim 3 , wherein: confocal detection is performed by the first detector; and
non-confocal detection is performed by the second detector.
5. The microscope according to claim 3 , wherein the following conditional expression is satisfied:
0.1 ≦PH/FWHM≦ 1,
where PH indicates central diameters of the first and second phase films and FWHM indicates a full-width half maximum of a longer axis of the laser beam.
6. The microscope according to claim 3 , wherein:
the laser light source is a semiconductor laser; and
the laser beam is led from the laser light source to the first or second phase-contrast objective without going through an optical fiber.
7. The microscope according to claim 3 , further comprising an image processing unit which images a detection result of each of the first and second detectors,
wherein the fluorescence observation and the phase-contrast observation are performed simultaneously.
8. A microscope comprising:
a first phase-contrast objective which includes a first phase film shaped like a ring and which has a 20-fold magnification or lower;
a second phase-contrast objective which includes a second phase film shaped like a ring and which has a 100-fold magnification or higher; and
a ring slit shared and used by the first and second phase-contrast objectives;
wherein:
the first phase film is placed at a pupil position of the first phase-contrast objective, and changes a phase of a laser beam by ¼ wavelength;
the second phase film is placed at a pupil position of the second phase-contrast objective, and changes a phase of a laser beam by ¼ wavelength;
when the first phase-contrast objective is used, the ring slit is placed at a position conjugate to the first phase film;
when the second phase-contrast objective is used, the ring slit is placed at a position conjugate to the second phase film; and
the following conditional expression is satisfied:
S PH2 /S OB2 ≦0.03,
where S OB2 indicates an area of a pupil of the second phase-contrast objective and S PH2 indicates an area of the second phase film.
9. The microscope according to claim 8 , further comprising a third phase-contrast objective having a magnification which is between a magnification of the first phase-contrast objective and a height magnification of the second phase-contrast objective,
wherein the ring slit is shared and used by the first, second and third phase-contrast objectives.