Microscope transmitted-illumination apparatus

A transmission-illumination apparatus for use in a microscope, the apparatus comprising:

• a transmission-illumination optical system having a light source, a condenser lens for collecting light emitted from the light source and illuminating a sample, and a shield;
• and
• an observation optical system including an objective lens for observing the sample,
• the condenser lens Including at least one lens group constructed to be attachable/detachable or switchable in accordance with a low magnification and a high magnification of the objective lens, and
• the shield being disposed at or near a pupil position of the condenser lens in a low-magnification mode thereof, which is conjugate with a pupil position of the objective lens, and controlling a shape of an aperture formed within a pupil of the objective lens,
• wherein the shield is shiftable in accordance with a low magnification and a high magnification of the objective lens, to satisfy a condition, D2/D1≦0.5, where D1 is an area of the pupil of the objective lens and D2 is an area of an aperture portion created in the pupils of the objective lens.

A transmission-illumination apparatus for use in a microscope, the apparatus comprising:

• a transmission-illumination optical system having a light source, two condenser lenses for a high magnification and a low magnification, for collecting light emitted from the light source and illuminating a sample and a shield;
• and
• an observation optical system including different objective lenses for observing the sample, having a high magnification of a range of ×10 to ×100 and a low magnification of a range of ×1.25 to ×4,
• the shield being disposed at or near a pupil position of the condenser lens in a low-magnification mode thereof, which is conjugate with a pupil position of the objective lens, and controlling a shape of art aperture formed within a pupil of the objective lens;
• and
• the condenser lenses being switchable with each other in accordance with a low magnification and a high magnification of the objective lens,
• wherein the condenser lenses are switched to satisfy a condition, NA2/NA1<0.6, where NA1 is a maximum illuminable numerical aperture of the condenser lens and NA2 is a numerical aperture of the objective lens at which a maximum illumination range of the condenser lens is observed.

A transmission-illumination apparatus for use in a microscope, the apparatus comprising:

• a transmission-illumination optical system having a light source, two condenser lenses for a high magnification and a low magnification, for collecting light emitted from the light source and illuminating a sample and a shield;
• and
• an observation optical system including different objective lenses for observing the sample, having a high magnification of a range of ×10 to ×100 and a low magnification of a range of ×1.25 to ×4,
• the shield being disposed at or near a pupil position of the condenser lens in a low-magnification mode thereof, which is conjugate with a pupil position of the objective lens, and controlling a shape of an aperture formed within a pupil of the objective lens;
• and
• the condenser lenses being switchable with each other in accordance with a low magnification and a high magnification of the objective lens,
• wherein the shield is shiftable in accordance with a low magnification and a high magnification of the objective lens, to satisfy a condition, D2/D1≦0.5, where D1 is an area of the pupil of the objective lens and D2 is an area of an aperture portion created in the pupil, of the objective lens.