JP3093003B2 - Transmission illumination system for microscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission illuminating apparatus for a microscope which uses a lens system by switching between a low magnification and a high magnification.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No. 61-34127,
U.S. Pat. No. 3,799,645 and U.S. Pat.
As disclosed in Japanese Patent No. 83, it is known that Koehler illumination, which is ideal as illumination for a microscope, can be realized from low magnification to high magnification by changing or moving a lens system and an aperture stop. That is, when the condenser lenses for low magnification and high magnification are theoretically compared based on the Helmholtz-Lagrange formula disclosed in Japanese Patent Publication No. 2-45164, the condenser lens for high magnification has a dry system and NA of 0.2.
9. Since the oil immersion system requires illumination performance of about NA 1.4, the focal length becomes short, and the illumination field becomes small. On the other hand, low-power condenser lenses have a wide illumination field,
A longer focal length is required. Therefore, due to this difference in focal length, when the Koehler illumination system is configured at low magnification and at high magnification, the aperture stop position is different.

[0003]

However, due to the difference in the aperture stop position, the following problems occur when special observation is performed by incorporating a turret disk of a universal condenser disclosed in Japanese Patent Publication No. 61-34126. Occurs. That is, in addition to the aperture stop for Koehler illumination, the turret disk has a phase difference ring slit,
A prism for differential interference, a ring slit for dark field, and the like are mounted, all of which need to be arranged near the aperture stop position. Therefore, if the aperture stop position differs between the low magnification and the high magnification, it is necessary to provide a plurality of turret disks corresponding to the aperture stop positions of the respective magnifications.
Further, in order to be able to use one turret disk corresponding to different aperture stop positions, it is necessary to improve the device structure such as increasing the width of the disk. When actually performing special observation by incorporating a turret disk,
The turret disk is mounted for high magnification, and Koehler illumination is configured at high magnification to perform observation.At low magnification, some lens groups are inserted and removed, and observation is performed with bright field illumination that deviates from Koehler illumination conditions. Was.

[0004] The present invention has been made in view of such problems of the prior art, it is an object of the <br/> sometimes when implementing Kohler illumination to high magnification from a low magnification Another object of the present invention is to provide a transmission illuminating device for a microscope that enables special observation of phase difference, differential interference, and the like by using a turret disk arranged at one position.

[0005]

In the transmission illumination apparatus for a microscope according to the present invention, the aperture stop positions of the low-magnification condenser lens and the high-magnification condenser lens are made substantially the same, and the following equations (1) and (1) are used. It satisfies the condition shown in 2). 0.22 <(Fh / Fl f) <0.45 ··· Equation (1) (Fh / Fl) <0.22 ··· Equation (2) where, Fh is the focal length of the high-magnification condenser lens, Fl
Is the focal length of the low-magnification condenser lens, and Flf is the focal length of the lens disposed between the aperture stop and the stage of the low-magnification condenser lens.

Accordingly, the aperture stop position is substantially the same at all magnifications for realizing Koehler illumination. Describing the above equation, equation (1) is a condition for making the aperture stop positions substantially the same. The value of (Fh / Fl f ) is the lower limit of 0.22
If the ratio is less than, the NA of the high-magnification condenser lens cannot be increased, or the illumination field of the low-magnification condenser lens becomes small. When the value exceeds the upper limit of 0.45, it is impossible to design a lens in which the aperture stop positions are the same. Equation (2) is a necessary condition for realizing Koehler illumination at low magnification and high magnification. If the value of (Fh / Fl) exceeds 0.22, the NA of the high-magnification condenser lens cannot be increased, or the illumination field of the low-magnification condenser lens decreases.

[0007] If an illumination system having such a configuration is provided with a configuration in which a special observation turret disk such as a differential interference prism, a phase difference ring slit, and a dark field ring slit can be mounted near the aperture stop position. At the same time, Koehler illumination can be realized from low magnification to high magnification, and at the same time, special observation such as phase difference and differential interference can be performed by a turret disk arranged at one place. Further, if a configuration is provided in which a condenser lens dedicated to dark field can be mounted, Koehler illumination can be realized from low magnification to high magnification, and at the same time, dark field observation with NA of about 0.8 or more can be performed.

[0008]

An embodiment will be described with reference to the drawings. Embodiment 1 A high-magnification condenser lens and a low-magnification condenser lens in the illuminating device of the embodiment 1 include an aperture stop 1 and lens groups L1, L2, and L3 as shown in FIGS. 1A and 1B.
And a slide glass 2 serving as a stage surface, and a high-magnification condenser lens shown in FIG. 1A and a low-magnification condenser lens shown in FIG. The distance D to the stage surface is substantially the same.

In this embodiment, the position of the aperture stop 1 is
The position differs from the paraxial position in order to consider the case where the stop is minimized by actual ray tracing. In this embodiment, the position of the phase difference ring slit of the high-magnification condenser lens is optimally about 5 mm from the position of the aperture stop 1 on the stage side. There is no problem in configuration. Of course, a high-magnification aperture stop may be added to this position.

The following are specification data of the high-magnification condenser lens and the low-magnification condenser lens of the present embodiment.
Where r ₀ , r ₁ ,... Are the radii of curvature of the lenses arranged in order from the light source side, d ₀ , d ₁ ,. ₁ ,
nd ₂ ,... are the d-line refractive indices of each lens, ν ₁ , ν ₂ ,
... is the d-line Abbe number of each lens. High magnification condenser lens r ₀ = ∞ (aperture stop) d ₀ = 9.7 r ₁ = 111.02 d ₁ = 8.77 nd ₁ = 1.48749 ν ₁ = 70.2 r ₂ = −17.26 d ₂ = 3. 16 nd ₂ = 1.58921 ν ₂ = 41.1 r ₃ = −59.01 d ₃ = 0.11 r ₄ = 21.59 d ₄ = 8.69 nd ₃ = 1.741 ν ₃ = 52.7 r ₅ = −27.78 d ₅ = 2.3 nd ₄ = 1.84666 ν ₄ = 23.8 r ₆ = 79.83 d ₆ = 0.23 r ₇ = 8.28 d ₇ = 6.9 nd ₅ = 1.741 ν ₅ = 52.7 r ₈ = 12. _{58 d 8 = 3.64 r 9 =} ∞ ( stage surface) Fh = 13.29 low-magnification condenser lens _{r 0 = 19.18 d 0 = 10.18} nd 1 = 1.77259 ν 1 = 49.7 r 1 = 43. 09 d ₁ = 11.3 r ₂ = −17.23 d ₂ = 1.87 nd ₂ = 1.74077 v ₂ = 27.8 r ₃ = −100.29 d ₃ = 2.06 r ₄ = ∞ (Aperture stop) d ₄ = 25.0 r ₅ = 68.31 d ₅ = 2.5 nd ₃ = 1.76182 ν ₃ = 26.6 r ₆ = 27.0 d ₆ = 8.0 nd ₄ = 1.6968 ν ₄ = 55.5 r ₇ = −29.8 d ₇ = 8.0 r ₈ = ∞ (stage surface) D = 43.5 Fl = 68.95 Flf = 32.44

Embodiment 2 As shown in FIGS. 2A and 2B, a high-magnification condenser lens and a low-magnification condenser lens in the illuminating device of Embodiment 2 have an aperture stop 1 and lens groups L1, L2 and L3.
And a slide glass 2 serving as a stage surface. In the high-magnification condenser lens shown in FIG. 2A and the low-magnification condenser lens shown in FIG. The distance D to the stage surface is substantially the same. Note that an oil for oil immersion having a small refractive index is injected between the lens unit L3 and the slide glass 2.

In this embodiment, as in the first embodiment, the position of the aperture stop 1 is different from the paraxial position in order to consider the case where the stop is minimized by actual ray tracing. In this embodiment, the position of the ring slit for phase difference of the high-magnification condenser lens is optimally about 9 mm from the position of the aperture stop 1 on the stage side. There is no problem in configuration. Of course, a high-magnification aperture stop may be added to this position.

The specification data of the high-magnification condenser lens and the low-magnification condenser lens of this embodiment are shown below. High magnification condenser lens r ₀ = ∞ (aperture stop) d ₀ = 10.4 r ₁ = 43.66 d ₁ = 9.0 nd ₁ = 1.56873 ν ₁ = 63.2 r ₂ = -21.71 d ₂ = 1. 9 nd ₂ = 1.78472 v ₂ = 25.7 r ₃ = −61.47 d ₃ = 0.3 r ₄ = 12.79 d ₄ = 6.4 nd ₃ = 1.58913 v ₃ = 61.0 r ₅ = 24.9 d ₅ = 0.3 r ₆ = 7.07 d ₆ = 8.0 nd ₄ = 1.62041 v ₄ = 60.3 r ₇ = −34.01 d ₇ = 1.1 nd ₅ = 1.72825 v ₅ = 28.5 r ₈ = ∞d ₈ = 0.6 (nd ₆ = 1.515 ν ₆ = 43.1) r ₉ = ∞ (stage surface) Fh = 10.0 Low magnification condenser lens r ₀ = 21.3 d ₀ = 7.2 nd ₁ = 1.6779 ν _{1 = 55.3 r 1 = 96.78 d} 1 = 14.3 r 2 = -20.2 d 2 = 1.8 nd 2 = 1.64769 ν 2 = 33.8 r 3 = -239.49 d 3 = 3.4 r ₄ = ∞ (Aperture stop _{Ri) d 4 = 26.0 r 5 =} 35.74 d 5 = 4.9 nd 3 = 1.7725 ν 3 = 49.7 r 6 = -66.98 d 6 = 7.1 r 7 = ∞ ( stage surface) D = 38.0 Fl = 60.21 Flf = 30.81

[0014]

As described above, according to the present invention, a microscope capable of realizing Koehler illumination from low magnification to high magnification and special observation of phase difference, differential interference, dark field, etc. by a turret disk arranged at one place. Transmission illumination device can be realized.

[Brief description of the drawings]

FIG. 1A is an embodiment of a transmission illumination apparatus for a microscope according to the present invention, wherein FIG.
(B) is a sectional view of the configuration of the low-magnification condenser lens.

FIG. 2A is a cross-sectional view of another embodiment of the transmission illumination device for a microscope according to the present invention, in which FIG.
(B) is a sectional view of the configuration of the low-magnification condenser lens.

[Explanation of symbols]

 Reference Signs List 1 aperture stop 2 slide glass L1, L2, L3 lens group

Continuation of front page (56) References JP-A-3-157609 (JP, A) JP-A-56-140313 (JP, A) JP-A-56-142509 (JP, A) JP-A-45-11946 (JP) , A) JP-A-54-59951 (JP, A) JP-A-51-43945 (JP, A) JP-A-56-69609 (JP, A) Fully open 47-49821 (JP, U) Fully open 60-76313 (JP, U) Jikken 48-7053 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 19/00-21/00 G02B 21/06-21 / 36

Claims (3)

(57) [Claims] In a transmission illumination device for a microscope which uses a lens system by switching between a low magnification and a high magnification, the aperture stop positions of a low magnification condenser lens and a high magnification condenser lens are made substantially the same, and A transmission illumination device for a microscope, wherein the transmission illumination device satisfies the conditions shown in (1) and (2). 0.22 <(Fh / Fl f) <0.45 ··· Equation (1) (Fh / Fl) <0.22 ··· Equation (2) where, Fh is the focal length of the high-magnification condenser lens, Fl
Is the focal length of the low-magnification condenser lens, and Flf is the focal length of the lens disposed between the aperture stop and the stage of the low-magnification condenser lens. 2. The transmitted illumination for a microscope according to claim 1, wherein a turret disk for special observation such as a prism for differential interference, a ring slit for phase difference, and a ring slit for dark field can be mounted near the aperture stop position. apparatus. 3. The transmission illumination device for a microscope according to claim 1, wherein a condenser lens dedicated to a dark field can be mounted.