JPH11174338A - Objective lens of microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an objective lens of a microscope which can be used in a wide wavelength range from visible light to about 2 μm near infrared light. SOLUTION: This objective lens of a microscope includes one or more combined lenses cosisting of a positive lens and a negative lens and having at least one combined surface. When νP-νN>0 holds assuming that the Abbe number of the positive lens is νP, a partial dispersion ratio on a t-line is θtP=(nc convex-nt convex)/(nF convex-nc convex), the Abbe number of the negative lens is νN and the partial dispersion ratio on the t-line (λ=1013.98 nm) is θtN=(nc concave-nt concave)/(nF concave-nc concave), the lens satisfies a condition; -0.0035<(θtP-θtN)/(νP-νN)<0.003 (1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microscope objective lens usable at wavelengths from visible light to near infrared light.

[0002]

2. Description of the Related Art In recent years, in equipment using a microscope,
In addition to observation with visible light, processing with the fundamental wave of near-infrared YAG laser, and 1.3 in IC circuits that handle high frequencies
Inspections in the μm band and 1.55 μm band, and inspections using an infrared microscope as a probe that captures a heat generation phenomenon due to an abnormal electricity supply are expanding.

[0003]

Normally, an instrument used for such an inspection is provided with an observation optical system as described above. For this reason, it is necessary to achromatize light in both bands of observation using light in the visible light region and inspection using light in the near infrared light region.

As the simplest method of achromatization, a method of observing an observation system with a black-and-white monitor and performing achromatization at a specific wavelength in the near-infrared region and a limited wavelength in the visible light region has been adopted. I have. However, since a near-infrared light of various wavelengths, for example, a light of 1064 nm which is a fundamental wave of a YAG laser, or a light of 1300 nm or 1550 nm handled in communication, a dedicated objective lens corresponding to the use must be provided, which is complicated. This is a problem. Further, when color observation is required for visible light, there is a problem that a method of achromatizing only a wavelength limited to a visible light region cannot cope with the problem.

[0005] In order to solve such a problem, apochromat color achromatization using fluorite having a large dispersion or phosphoric acid-based abnormal dispersion glass has been performed. However, due to the high degree of achromatism, the overall length of the lens is long, and the optical system has a large number of lenses. In addition, there is no one that satisfactorily corrects achromatism from visible light to near-infrared light near the 2 μm region. For example, the lens disclosed in Japanese Patent Publication No. Hei 7-104488 is achromatized from visible light to a wavelength slightly over 1064 nm. However, the overall length of the lens is long and the barrel length is 95m
The objective lens is as large as m and cannot be used for ordinary microscopes.

The lens disclosed in Japanese Patent Application Laid-Open No. Sho 62-49313 has a working distance (Working Di).
(hereinafter, referred to as "WD") is small and difficult to handle in operation.

The present invention has been made in view of the above problems, and achieves achromatism in a wide wavelength range from visible light to near-infrared light of about 2 μm, and in particular, chromatic aberration is sufficiently corrected within a depth of focus. An object of the present invention is to provide a microscope objective lens which has sufficient WD, has good operability, is small in size, and can be used for ordinary microscopes.

[0008]

In order to achieve the above object, a microscope objective according to the present invention comprises a microscope objective including at least one cemented lens composed of a positive lens and a negative lens having at least one cemented surface. In the lens, the Abbe number of the positive lens is νP, and the F-line (λ
= 486.13 nm), the refractive index of the positive lens with respect to the C line (λ = 656.28 nm) is nc convex, and the refractive index of the positive lens with respect to the C line (λ = 656.28 nm).
m), the refractive index is nt convex, and the t-line (λ
= 1013.98 nm), the partial dispersion ratio is θt convex = (nc convex−nt convex) / (nF convex−nc convex), the Abbe number of the negative lens is νN, and the F line of the negative lens (λ = 486.13 nm). ), The refractive index of the negative lens with respect to the C line (λ = 656.28 nm) is nc concave, and the refractive index of the negative lens is t line (λ = 1013.9).
8 nm) and the partial dispersion ratio at the t-line (λ = 1013.98 nm) of the negative lens is θt.
When νP−νN> 0 when N = (nc concave−nt concave) / (nF concave−nc concave), −0.0035 <(θtP−θtN) / (νP−νN) <0. 003 (1) is satisfied.

Further, in the microscope objective lens of the present invention, even in a bonded lens including the positive lens and the negative lens and having two or more bonding surfaces, for the adjacent positive lens and the negative lens, νP−νN> When it is 0, it is desirable to satisfy the condition of -0.0035 <(θtP-θtN) / (νP-νN) <0.003 (1).

The microscope objective lens according to the present invention having the above configuration can be widely applied to a wide range of magnification from about 5 × to about 100 ×. As a basic lens design concept, in the present invention, not only positive and negative (for example, concave and convex) doublets but also positive and negative (for example, convex and concave) or negative positive and negative (for example, concave and convex)
Skillfully uses the lens configuration described above.

In general, Koenig's method is known as a method for correcting a color that appears due to residual chromatic aberration with respect to a third wavelength, that is, a secondary spectrum using partial dispersion. Hereinafter, Koenig's method will be described.

The value Δf ′ of the secondary spectrum can be expressed by the following equation: Δf ′ = f × (θP−θN) / (νP−νN)

Here, .nu.P is the Abbe number of the positive lens forming the doublet, .nu.N is the Abbe number of the negative lens forming the doublet, .theta.P is the partial dispersion ratio of the positive lens forming the doublet, and .theta.N is the negative lens portion forming the doublet. The dispersion ratio, f, represents the combined focal length of the doublet, respectively.

In the Koenig method, in principle, the brightness of the optical system is restricted by the power arrangement of the constituent doublets, and it is not possible to construct a lens having an arbitrary large aperture ratio while maintaining the secondary spectrum. However, by dividing the power into a plurality of doublets and configuring each doublet with a small secondary spectrum, it is possible to keep the secondary spectrum of the entire system small. However, when the lens system is divided into a plurality of doublets, there is a problem in that the number of constituent lenses increases unnecessarily. Further, in a microscope objective lens, when a long working distance and flatness of an image surface are required, various aberrations other than chromatic aberration must be well corrected, so that the degree of freedom of lens bending is lost. It is a problem that we cannot stick to the achromatization condition alone.

In order to solve the above problem, it is important to effectively correct chromatic aberration, especially a secondary spectrum, among lens types (for example, Tessar type, Gauss type, etc.) suitable for a desired magnification. Becomes The use of three positive / negative positive or negative / positive lens elements in addition to the doublet makes it possible to correct such a secondary spectrum.

A general solution of the conditions for achromatization of three colors in a three-element cemented lens (ie, conditions for reducing the secondary spectrum) is described on page 55 of "Optics" (Iwanami Shoten) by Hiroshi Kubota. As shown, for the following determinant,

(Equation 1) It is necessary to be. Several general solutions satisfying the determinant are conceivable, but the following two concepts (A) and (B) are practically effective.

(A) Efficiently use two sets of four doublets
Replace with a set of positive / negative positive or negative / negative. (B) In order to arbitrarily change the apparent partial dispersion ratio of the doublet negative lens, a negative lens and a positive lens are bonded to each other, and a positive, negative, positive, and three lens elements are formed as a whole.

First, with regard to the concept (A), when the center lens of the three cemented lenses is divided by a certain plane, 2
It can be intuitively understood that it can be replaced with a pair of positive / negative, negative / positive or two pairs of negative / positive / positive / negative doublet.

Regarding the concept (B), when one negative lens is replaced with a cemented lens of a negative lens and a positive lens, the apparent Abbe number νN when the cemented lens is one lens is The following equation: 1 / (f · νN) = 1 / (f1 · ν1) + 1 / (f2 ·
ν2) 1 / νN = f2 / (f1 + f2) × 1 / ν1 + f1 /
It can be expressed by (f1 + f2) × 1 / ν2.

Where f1 is the focal length of the negative lens, f2
Is the focal length of the positive lens, ν1 is the Abbe number of the negative lens, ν
2 represents the Abbe number of the positive lens, and f represents the focal length of the entire bonded lens.

The apparent partial dispersion θN and apparent dispersion ratio ν ′ are expressed by the following equation: 1 / fν ′ = 1 / (f1 · ν1 ′) + 1 / (f2 · ν
2 ′) θN = ν / ν ′ = fν / (f2 · ν2) × θ2 + fν /
It can be represented by (f1 · ν1) × θ1.

Where ν1 ′ is the dispersion ratio of the negative lens for the third color, ν2 ′ is the dispersion ratio of the positive lens for the third color, θ1 is the partial dispersion of the negative lens, and θ2 is the partial dispersion of the positive lens. Each is represented.

To clearly show how to change the apparent partial variance, assuming that ν1２ ， ν2, θ1２θ2,
The above equation becomes θN = f / f2 × θ2 + f / f1 × θ1. Therefore, by appropriately selecting the combination of the focal lengths f1 and f2, the apparent partial dispersion ratio can be arbitrarily changed.

If the doublet component composed of the negative lens and the positive lens is treated as one lens component having an apparent partial dispersion ratio θN, (θP−θN) / (νP−ν
The value of N) can be reduced.

In the microscope objective lens of the present invention, based on the concept of the above (A), 2
The next spectrum can be reduced to a value according to its role in the overall system. Further, based on the concept of the above (B), a glass having a partial dispersion ratio that does not actually exist can be created by a doublet, and desired secondary spectrum correction can be realized.

Therefore, the bonding surface should be at least one.
When performing achromatism from visible light to near-infrared light in the vicinity of 2 μm in an optical system including at least one bonded lens having one lens, a partial dispersion ratio θt of t-line (1013.98 nm) = (nC−nt) It is appropriate to use / (nF-nC). When the Abbe numbers of the positive lens and the negative lens that constitute the cemented lens are νP and νN, and the partial dispersion ratios at the t-line of the positive lens and the negative lens that constitute the cemented lens are θtP and θtN, νP In the case of adjacent laminated lenses satisfying −νN> 0, −0.0
035 <(θtP−θtN) / (νP−νN) <0.0
By satisfying conditional expression 03 (1), supercolor achromaticity from visible light to about 2 μm can be achieved.

The lower limit of conditional expression (1) is a limit for selecting a negative lens when fluorite is used for the positive lens, and cannot be less than the lower limit. Also, in a lens combination that exceeds the upper limit, NA (numerical aperture)
Even with an objective of about 0.13, it is difficult to correct the achromatism from visible to infrared to the depth of focus level.

Further, in the microscope objective lens of the present invention, in addition to the conditional expression (1), when νP−νN> 0, the positive lens and the negative lens are: 15 <νP−νN <72 (2) 23 <νN It is desirable to satisfy the condition of <71 (3).

The conditional expressions (2) and (3) further define conditions for ensuring a practical solution for super achromatism.

The lower limit of the conditional expression (2) is a lower limit necessary for balancing the partial dispersion ratio and the achromatic condition.
Therefore, if the value goes below the lower limit of conditional expression (2), the number of lenses will increase unnecessarily. The upper limit of conditional expression (2) indicates the limit of glass selection necessary to satisfy conditional expression (1).

Conditional expression (3) defines a practical glass range for reducing the partial dispersion as a negative lens. If a glass out of the range of the conditional expression (3) is selected, the effect of super achromatism cannot be obtained.

In the microscope objective lens of the present invention, when the positive lens and the negative lens adjacent to the cemented lens satisfy νP−νN <0, 0.005 <(θtP−θtN) / (νP −νN) <0.04 (4)

Conditional expression (4) is an expression for defining conditions necessary for glass materials of adjacent laminated lenses to create a partial dispersion ratio that does not actually exist. By satisfying such conditions, the effect of super-color achromatism is further exhibited.

When the value goes below the lower limit of conditional expression (4), the effect of the doublet for producing the partial dispersion ratio is lost. For this reason, it becomes a combination of ordinary glass, and cannot achieve superchromatism. For reference, the partial dispersion ratio when ordinary glass is used is (θtP−θtN) / (νP−νN) ≒ 0.0047.

The upper limit value of the conditional expression (4) is a value close to the limit value that greatly changes the apparent partial dispersion ratio. Therefore, if the value exceeds the upper limit, it is possible to change the partial dispersion value, but it becomes difficult to correct other aberrations, and it becomes impossible to obtain a practically balanced lens configuration.

The microscope objective lens of the present invention is desirably a Tessar type, Gaussian type, or a retrofocus type objective lens having a negative refractive power on the farthest side from the object side. By using a lens type suitable for magnification, super achromatism can be effectively performed with a small number of lenses.

[0037]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a diagram showing a lens configuration of a microscope objective according to a first embodiment of the present invention. The lens has a focal length f = 40 mm and a numerical aperture NA ′
= 0.13 (Fno = 3.8) and f = 200 mm
Is an optical system that constitutes an objective lens with a magnification of 5 × when combined with the second objective lens. In the optical system having such specifications, a Tessar type optical system is often used as a system having the smallest number of lenses. In the present embodiment, from the side farther from the object point, one cemented lens, a biconcave single lens,
It consists of a biconvex single lens. Then, assuming that the dispersion of the positive lens and the negative lens having at least one bonding surface and sharing the bonding surface is νP and νN, respectively, ν
(ΘP−θN) / (νP−νN) under the condition of P−νN> 0
Is in the range of -0.0035 to 0.003, which is a condition necessary for performing achromatism over a wide range from visible light to infrared light.

Table 1 below shows values of specifications of the microscope objective according to the first embodiment. In the table, the surface number is the number of the lens surface counted from the farthest side from the object, r is the radius of curvature, d is the surface interval, and nd is the d line (λ = 587.56 nm).
, Νd is the Abbe number, θt is the t-line (λ = 1
013.98 nm). Further, in all of the following embodiments, the same reference numerals as those in the first embodiment are used.

[0040]

[Table 1] Surface No. 21.55528) 1.000000 (Conditional value) When νP−νN = 41.9 (> 0), (1) (θP−θN) / (νP−νN) 0.0014 (2) νP−νN 41.9 (3) ΝN 39.7 Here, νP of the positive lens is 81.6, θP = 0.824, and νN of the negative lens is 39.7, θN = 0.766.

FIG. 2 is a diagram showing various aberrations of the microscope objective lens according to the first example. In the figure, F is the F line (λ = 486.13 nm), and d is the d line (λ = 587.5).
6 nm), t is the t-line (λ = 1013.98 nm), 1.
Reference numeral 97 denotes λ = 1970 nm (1.97 μm). Further, in all of the following embodiments, the same reference numerals as those in the first embodiment are used. In all of the following examples, only the objective lens is the same as the photographic lens.
The graph shows various aberrations on the object point side when the light ray is traced backward from て, assuming the system.

As is apparent from FIG. 2, the F line, d line, t line
It can be seen that the chromatic aberration of the line 1.97 μ is corrected sufficiently small with respect to the value of the depth of focus.

(Second Embodiment) FIG. 3 is a diagram showing a lens configuration of a microscope objective according to a second embodiment of the present invention. The lens according to the present example has f = 20 mm and NA ′ =
0.21 (Fno = 2.38), which is an optical system that constitutes a 10 × magnification objective lens when combined with the second objective lens (f = 200 mm), and is based on a Gaussian lens.

In this embodiment, a biconvex single lens, two cemented lenses, and two biconvex single lenses are arranged from the farthest point from the object point.

Table 2 shows values of specifications of the microscope objective according to the second embodiment.

[0046]

[Table 2] Surface No. 8 29.42000 3.90000 1.433850 95.3 0.8048 9 -8.76100 0.10000 1.000000 10 53.62500 4.00000 1.497000 81.6 0.8236 11 -12.26400 0.10000 1.000000 12 33.98200 4.00000 1.743200 49.3 0.7979 13 -93.01700 (24.00026) 1.000000 (Conditional value) (1) (θ1P-θ1N) / ( ν1P−ν1N) = (θ2P−θ2N) / (ν2P−ν2N) 0.00071 (2) ν1P−ν1N = ν2P−ν2N 55.6 (3) ν1N = ν2N 39.7 Here, bonding of the second embodiment The ratio of the difference between the Abbe number of each positive lens and the negative lens and the difference between the partial dispersion ratios of the two components is (θ1P−θ1N) / (ν1P−ν1N), respectively. θ2P-θ2N) and / (ν2P-ν2N).

FIG. 4 is a diagram showing various aberrations of the microscope objective lens according to the second example. As is clear from FIG. 4, the chromatic aberration of the F line, the d line, the t line, and 1.97 μm are satisfactorily corrected.

(Third Embodiment) FIG. 5 is a diagram showing a lens configuration of a microscope objective according to a third embodiment of the present invention. The lens according to the present example has f = 20 mm and NA ′ =
0.21 (Fno = 2.38), and is an optical system that constitutes a 10 × magnification objective lens when combined with the second objective lens (f = 200 mm). This embodiment is based on a Gaussian lens as in the second embodiment, and is a lens type according to the second embodiment that provides the same performance without using fluorite.

This embodiment is composed of a meniscus lens, two three-unit cemented lenses, and a biconvex single lens from the far side from the object point.

Table 3 shows values of specifications of the microscope objective according to the third embodiment.

[0051]

[Table 3] Surface number rd nd vd θt 1 18.44100 1.85000 1.582670 46.4 0.7550 2 192.82600 0.20000 1.000000 3 11.16700 1.90000 1.593189 67.9 0.7958 4 -44.53200 0.80000 1.612658 44.4 0.7907 5 3.76100 1.50000 1.667551 42.0 0.7339 6 5.83200 1.50000 1.000000 7 0.00000 1.50000 1.000000 11.83500 2.00000 1.617501 30.8 0.6797 9 -4.35000 5.90000 1.756920 31.6 0.7053 10 55.72800 3.00000 1.497820 82.5 0.8178 11 -10.06200 0.20000 1.000000 12 20.89800 2.50000 1.719999 50.2 0.7784 13 -36.06100 (20.49968) 1.000000 (Conditional value) The composite lens includes two components, and the Abbe number and partial dispersion ratio of the three positive lenses, the negative lens, and the positive lens which are farther from the object point are respectively ν1FP, ν1N, ν1RP, θ1FP,
θ1N, θ1RP, Abbe number and partial dispersion ratio of three positive lenses, a negative lens, and a positive lens, which are closer to the object point, are ν2FP, ν2N, ν2RP, θ2FP, θ2N, θ
Assuming that 2RP, when ν1FP−ν1N = 23.5 (> 0), (1) (θ1FP−θ1N) / (ν1FP−ν1N) 0.00022 (2) ν1FP−ν1N 23.5 (3) ν1N 44. 4 When ν2RP−ν2N = 50.9 (> 0), (1) (θ2RP−θ2N) / (ν2RP−ν2N) 0.0022 (2) ν2RP−ν2N 50.9 (3) ν2N 31.6 When ν1RP−ν1N = −2.44 <0, (4) (θ1RP−θ1N) / (ν1RP−ν1N) 0.023 When ν2FP−ν2N = −0.8 <0, (4) (θ2FP−θ2N) ) / (Ν2FP−ν2N) 0.032 The bonded part of ν1RP and ν1N, and ν2FP and ν2N creates an apparent partial dispersion.

FIG. 6 is a diagram showing various aberrations of the microscope objective lens according to the third example. As is clear from FIG. 6, it can be seen that various aberrations including chromatic aberration up to 1.083 μm are well corrected.

(Fourth Embodiment) FIG. 7 is a diagram showing a lens configuration of a microscope objective according to a fourth embodiment of the present invention. The lens according to the present example has f = 20 mm and NA ′ =
0.21 (Fno = 2.38), and is an optical system that constitutes a 10 × magnification objective lens when combined with the second objective lens (f = 200 mm). The microscope objective lens according to the fourth embodiment is a unique type in which a meniscus component is arranged on the farthest side from the object point, and the power arrangement is intermediate between the third and fifth embodiments. 2 farther from the object
The components to be laminated and three components to be laminated are arranged closer to each other.

This embodiment is composed of one meniscus lens, one cemented lens, one cemented lens, and one biconvex lens from the far side from the object point.

Table 4 shows values of specifications of the microscope objective lens according to the fourth example.

[0056]

[Table 4] Surface number rd nd νd θt 1 7.57666 4.60000 1.516330 64.1 0.8687 2 5.44755 1.80000 1.000000 3 0.00000 1.80000 1.000000 4 -7.38361 1.20000 1.613400 44.3 0.7935 5 10.49736 4.50000 1.603000 65.5 0.8280 6 -13.00974 0.20000 1.000000 7 20.66253 0.90000 1.516330 64.1 0.8 9.75832 7.00000 1.497000 81.6 0.8236 9 -9.06225 0.90000 1.516330 64.1 0.8687 10 -28.55930 0.10000 1.000000 11 34.10985 3.00000 1.603000 65.5 0.8280 12 -45.52425 (20.50003) 1.000000 (Conditional value) The Abbe number of the two bonded positive and negative lenses is ν1P , Ν1N and partial dispersion ratios θ1P, θ1
N, when the Abbe numbers of the negative lens, the positive lens, and the negative lens that are bonded to each other are ν2FN, ν2P, ν2RN, and the partial dispersion ratios are θ2FN, θ2P, and θ2RN, respectively. In the case of ν1P−ν1N = 21.2> 0 (1) (θ1P−θ1N) / (ν1P−ν1N) 0.00163 (2) ν1P−ν1N 21.2 (3) ν1N 44.3 ν2P−ν2FN = ν2P−ν2RN = 17.5> 0, (1) (θ2P−θ2FN) / (ν2P−ν2FN) = (θ2P−θ2RN) / (ν2P−ν2RN) −0.00258 (2) ν2P−ν2FN = ν2P−ν2RN 17.5 (3) ν2FN = ν2RN 64 .1

FIG. 8 is a diagram showing various aberrations of the microscope objective lens according to the fourth example. As is clear from FIG. 8, it can be seen that various aberrations including chromatic aberration are well corrected.

(Fifth Embodiment) FIG. 9 is a diagram showing a lens configuration of a microscope objective according to a fifth embodiment of the present invention. The lens according to the present example has f = 20 mm and NA ′ =
0.21 (Fno = 2.38), which is an optical system constituting an objective lens with a magnification of 10 × when combined with the second objective lens. This is a retrofocus type objective lens including three components of a negative doublet, a positive doublet, and a positive doublet from a far side from an object point.

This embodiment is composed of two cemented lenses, a biconvex single lens, a two-element cemented lens, and one meniscus lens from the side farther from the object point.

Table 5 shows values of specifications of the microscope objective according to the fifth embodiment.

[0061]

[Table 5] Surface No. 1.497000 81.6 0.8236 8 -37.86193 0.35498 1.000000 9 32.45733 1.60000 1.784700 26.3 0.6726 10 15.14556 6.10000 1.497000 81.6 0.8236 11 -49.02589 0.20000 1.000000 12 19.59653 3.60000 1.497000 81.6 0.8236 13 69.85030 (25.72940) 1.000000 (Conditional value) The Abbe numbers and partial dispersion ratios of the positive lens and the negative lens in each of the two doublets are ν1P, ν1N, θ1P, θ1N, ν2P, ν
2N, θ2P, θ2N, ν3P, ν3N, θ3P, θ3
If N, ν1P−ν1N = −28.5 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.0055 ν1N = 53.9 ν2P−ν2N = 17.5> 0 , (1) (θ2P−θ2N) / (ν2P−ν2N) −0.00258 (2) ν2P−ν2N 17.5 (3) ν2N 64.1 When ν3P−ν3N = 55.3> 0, (1) (Θ3P-θ3N) / (ν3P-ν3N) 0.00273 (2) ν3P-ν3N 55.3 (3) ν3N 26.3

FIG. 10 is a view showing various aberrations of the microscope objective lens according to the fifth example. As is clear from FIG. 10, various aberrations including chromatic aberration are well corrected.

(Sixth Embodiment) FIG. 11 is a diagram showing a lens configuration of a microscope objective according to a sixth embodiment of the present invention. The lens according to this example has f = 10 mm, NA ′
= 0.35 (Fno = 1.43), and when combined with the second objective lens (f = 200 mm), the optical system constitutes an objective lens with a magnification of 20 ×. It contains three bonding components, that is, a negative doublet, a three-layer bonding component, and a positive doublet from the far side from the object point.

This embodiment is composed of a two-piece cemented lens, a three-piece cemented lens, a biconvex single lens, a two-piece cemented lens, and a meniscus lens from the side farther from the object point.

Table 6 shows values of specifications of the microscope objective lens according to the sixth example.

[0066]

[Table 6] Surface No. 1.696800 55.5 0.8330 8 -19.30050 0.40000 1.000000 9 35.21700 3.70000 1.497000 81.6 0.8236 10 -33.39300 0.40000 1.000000 11 25.80700 1.60000 1.805180 25.4 0.6680 12 14.15100 5.50000 1.456000 90.3 0.8425 13 -39.62300 0.20000 1.000000 14 16.54100 3.50000 1.497000 81.6 0.8236 15 49.5320000000 (1549.5320000000) Corresponding values) Abbe numbers of the positive and negative lenses of the negative doublet and the negative lens are ν1P and ν1N, and the partial dispersion ratios are θ1P and θ1.
The Abbe number and partial dispersion ratio of the negative lens, the positive lens, and the negative lens of the N3 cemented lenses are ν2FN and ν2, respectively.
Assuming that P, ν2RN, θ2FN, θ2P, θ2RN, the positive lens of the positive doublet, the Abbe number of the negative lens, and the partial dispersion ratio are ν3P, ν3N, θ3P, and θ3N, respectively, ν1P−ν1N = -28.5 <0 ν1N = 53.9 (4) (θ1P−θ1N) / (ν1P−ν1N) 0.0055 When ν2P−ν2FN = ν2P−ν2RN = 39.5> 0, (1) (θ2P−θ2FN) / (ν2P−) ν2FN) = (θ2P−θ2RN) / (ν2P−ν2RN) 0.000101 (2) ν2P−ν2FN = ν2P−ν2RN 39.5 (3) ν2FN = ν2RN 55.5 ν3P−ν3N = 64.9> 0 , (1) (θ3P-θ3N) / (ν3P-ν3N) 0.00269 (2) ν3P-ν3N 64.9 (3) ν3N 25.4

FIG. 12 is a diagram showing various aberrations of the microscope objective according to the sixth example. As is apparent from FIG. 12, various aberrations including chromatic aberration including 1.97 μm are well corrected.

(Seventh Embodiment) FIG. 13 is a view showing a lens configuration of a microscope objective according to a seventh embodiment of the present invention. The lens according to this example has f = 10 mm, NA ′
= 0.35 (Fno = 1.43), and when combined with the second objective lens (f = 200 mm), the optical system constitutes an objective lens with a magnification of 20 ×. It includes three bonding elements of a negative doublet, a three-ply bonding component, and a positive doublet from the farther side than the object point.

This embodiment is composed of a two-piece cemented lens, a three-piece cemented lens, a biconvex single lens, a two-piece cemented lens, and a meniscus lens from the side farther from the object point.

Table 7 shows values of specifications of the microscope objective according to the seventh embodiment.

[0071]

[Table 7] Surface number rd nd vd θt 1 -15.86459 1.00000 1.713000 53.9 0.8190 2 5.71807 3.30000 1.805182 25.3 0.6600 3 12.80834 3.10000 1.000000 4 -71.11591 5.00000 1.433852 95.2 0.8050 5 -5.80277 1.00000 1.516800 64.1 0.8660 6 22.92380 5.50000 1.433852 95.2 0.8 15.39949 0.30000 1.000000 8 33.77884 5.90000 1.497820 82.5 0.8180 9 -33.38411 0.30000 1.000000 10 27.02883 1.60000 1.784702 26.1 0.6640 11 14.40390 6.50000 1.497820 82.5 0.8180 12 -33.14799 0.20000 1.000000 13 24.69375 3.50000 1.696800 55.6 0.8320 14 53.51081 (20.49998) 1.000000 The Abbe number and partial dispersion ratio of the doublet positive lens and negative lens are ν1P, ν1N, θ1P, θ1.
N, Abbe number and partial dispersion ratio of the positive lens, the negative lens, and the positive lens of the three cemented lenses are ν2FP and ν2, respectively.
Assuming that ν3P, ν3N, θ3P, and θ3N are N, ν2RP, θ2FP, θ2N, θ2RP, the positive lens of the positive doublet, the Abbe number of the negative lens, and the partial dispersion ratio, respectively, when ν1P−ν1N = −28.6 <0, ν1N = 53.9 (4) (θ1P−θ1N) / (ν1P−ν1N) = 0.0056 When ν2FP−ν2N = ν2RP−ν2N = 31.1> 0 (1) (θ2FP−θ2N) / (ν2FP−) ν2N) = (θ2RP−θ2N) / (ν2RP−ν2N) −0.00196 (2) ν2FP−ν2N = ν2RP−ν2N 31.1 (3) When ν2N 64.1 ν3P−ν3N = 56.4> 0, (1) (θ3P-θ3N) / (ν3P-ν3N) 0.00273 (2) ν3P-ν3N 56.4 (3) ν3N 26.1

FIG. 14 is a diagram showing various aberrations of the microscope objective according to the seventh embodiment. As is clear from FIG. 14, various aberrations including chromatic aberration are well corrected.

(Eighth Embodiment) FIG. 15 is a diagram showing a lens configuration of a microscope objective according to an eighth embodiment of the present invention. The lens according to the present example has f = 4 mm and NA ′ =
0.45 (Fno = 1.11), and when combined with the second objective lens (f = 200 mm), is an optical system that constitutes an objective lens with a magnification of 50 ×. This is a lens configuration including three doublets bonded together and four bonding elements after two doublets from a side farther than the object point.

In this embodiment, a biconcave single lens, two cemented lenses, a triple cemented lens, a double cemented lens, and a , And a meniscus lens.

Table 8 shows values of specifications of the microscope objective according to the eighth embodiment.

[0076]

[Table 8] Face number rd nd νd θt 1 -5.55090 3.50000 1.693500 53.2 0.8136 2 11.17000 1.70000 1.000000 3 -16.26080 4.00000 1.784700 26.3 0.6726 4 -4.00600 4.00000 1.720470 34.7 0.7303 5 -9.60010 1.30000 1.000000 6 98.10800 1.00000 1.720470 34.7 0.7303 7 12.0000 1.433850 95.3 0.8048 8 -31.19000 0.20000 1.000000 9 73.10000 5.60000 1.433850 95.3 0.8048 10 -9.50770 2.70000 1.720470 34.7 0.7303 11 17.93320 4.40000 1.497000 81.6 0.8236 12 -28.65800 0.10000 1.000000 13 36.25600 2.00000 1.713000 53.9 0.8193 14 18.50920 6.00000 1.433850 95.3 0.8048 1500000 42.54800 4.40000 1.497000 81.6 0.8236 17 -20.99990 0.20000 1.000000 18 17.09950 3.00000 1.729160 54.7 0.8244 19 54.61100 (14.29678) 1.000000 (Conditional value) Abbe number of first doublet, Abbe number of negative lens, partial dispersion in order from the farthest point The ratios are ν1P, ν1N, θ1P, θ1N, respectively, the following doublet positive lens and negative lens Abbe number and a partial dispersion ratio, respectively ν2P, ν2N, θ2P, positive lens, negative lens cemented lens three Shita2N, Abbe number of the positive lens, the partial dispersion ratio, respectively ν3FP, ν3N,
ν3RP, θ3FP, θ3N, θ3RP, the Abbe numbers of the third doublet from the farthest object, the negative lens, the Abbe number of the positive lens, and the partial dispersion ratio are ν4P and ν4, respectively.
If N, θ4P, θ4N, ν1P−ν1N = −8.4 <0, ν1N = 34.7 (4) (θ1P−θ1N) / (ν1P−ν1N) 0.00686 ν2P−ν2N = 60.6 > 0, (1) (θ2P−θ2N) / (ν2P−ν2N) 0.00123 (2) ν2P−ν2N 60.6 (3) ν2N 34.7 ν3FP−ν3N = 60.6> 0, (1) (θ3FP−θ3N) / (ν3FP−ν3N) 0.00123 (2) ν3FP−ν3N 60.6 (3) ν3N 34.7 ν3RP−ν3N = 46.9> 0, (1) (θ3RP) −θ3N) / (ν3RP−ν3N) 0.00199 (2) ν3RP−ν3N 46.9 (3) ν3N 34.7 ν4P−ν4N = 41.4> 0, (1) (θ4P−θ4N) / ( ν4P-ν4N) -0.0 035 (2) ν4P-ν4N 41.4 (3) ν4N 53.9

FIG. 16 is a diagram showing various aberrations of the microscope objective according to the eighth embodiment. As is clear from FIG. 16, various aberrations including chromatic aberration of 1.97 μm from visible light are well corrected.

(Ninth Embodiment) FIG. 17 is a diagram showing a lens configuration of a microscope objective according to a ninth embodiment of the present invention. The lens according to the present example has f = 4 mm and NA ′ =
0.45 (Fno = 1.11), and when combined with the second objective lens (f = 200 mm), is an optical system that constitutes an objective lens with a magnification of 50 ×. It includes three bonding elements of a first doublet, a first triple-bonded lens, and a second triple-bonded lens from a side farther away from the object point.

In the present embodiment, the biconcave single lens, the two cemented lenses, the three cemented lenses, the biconvex single lens, the three cemented lenses, It is composed of a single lens and a meniscus lens.

Table 9 shows values of specifications of the microscope objective according to the ninth embodiment.

[0081]

[Table 9] Surface No. 6.20000 1.433852 95.3 0.8048 8 -9.19822 2.00000 1.720470 34.7 0.7303 9 -16.03374 0.30000 1.000000 10 134.50449 4.70000 1.497000 81.6 0.8236 11 -19.55141 0.10000 1.000000 12 79.69972 4.60000 1.433852 95.3 0.8048 13 -17.08425 1.00000 1.613400 44.3 0.7935 14 19.04049 0.80000 1.433852 9 1.000000 16 24.72587 3.30000 1.497000 81.6 0.8236 17 -71.32577 0.20000 1.000000 18 13.34191 3.00000 1.755000 52.3 0.8107 19 28.75808 (15.19984) 1.000000 (Conditional value) Positive lens of the first doublet, Abbe number of the negative lens from the farthest point from the object point, part Dispersion ratios are respectively ν1P, ν1N, θ1P, θ1N, a negative lens of the first three cemented lenses, Lens, the Abbe number of the negative lens,
The partial dispersion ratios are ν2FN, ν2P, ν2RN, θ
2FN, θ2P, θ2RN, Abbe number and partial dispersion ratio of the positive lens, the negative lens, and the positive lens of the second three-piece cemented lens are ν3FN, ν3N, ν3RP, and θ3F, respectively.
Assuming that N, θ3N, and θ3RP, when ν1P−ν1N = −11.9 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.007 ν1N = 39.7 ν2P−ν2FN = ν2P−ν2RN = 60.6> 0, (1) (θ2P−θ2FN) / (ν2P−ν2FN) = (θ2P−θ2RN) / (ν2P−ν2RN) 0.00123 (2) ν2P−ν2FN = ν2P−ν2RN 60. 6 (3) ν2FN = ν2RN 34.7 ν3FP−ν3N = ν3RP−ν3N = 51.0> 0, (1) (θ3FP−θ3N) / (ν3FP−ν3N) = (θ3RP−θ3N) / (ν3RP−) ν3N) 0.00022 (2) ν3FP-ν3N = ν3RP-ν3N 51.0 (3) ν3N 44.3

FIG. 18 is a diagram showing various aberrations of the microscope objective according to the ninth embodiment. As is clear from FIG. 18, it is understood that various aberrations including chromatic aberration are well corrected.

(Tenth Embodiment) FIG. 19 shows a first embodiment of the present invention.
It is a figure showing the lens composition of the microscope objective lens concerning Example 0. The lens according to the present example has f = 4 mm, N
A ′ = 0.45 (Fno = 1.11), and this optical system constitutes an objective lens with a magnification of 50 × when combined with the second objective lens. It includes three bonding elements of a first doublet, a first three-layer bonding, and a second three-layer bonding lens from the farther side than the object point.

In this embodiment, a biconcave single lens, a two-unit cemented lens, a biconvex single lens,
The three laminated lenses are composed of two lenses, a biconvex single lens, and a meniscus lens.

Table 10 shows values of specifications of the microscope objective lens according to Example 10.

[0086]

[Table 10] Surface No. 0.10000 1.000000 8 -22.32400 1.00000 1.671630 38.8 0.7541 9 15.10900 5.50000 1.433850 95.3 0.8048 10 -7.83000 1.00000 1.803840 33.9 0.7156 11 -14.24700 0.20000 1.000000 12 29.91900 4.00000 1.617500 30.8 0.6797 13 -43.36200 1.00000 1.756920 31.6 0.70534 14 16.55100 4.50000 1.433850 95.3 0.8 1.000000 16 19.71800 3.30000 1.497820 82.5 0.8178 17 -65.88000 0.20000 1.000000 18 13.44200 3.00000 1.748100 52.3 0.805286 19 27.65300 (15.00000) 1.000000 (Conditional value) The Abbe number and partial dispersion ratio of the first doublet positive lens and negative lens are ν1P, ν1N, θ
1P, θ1N, the Abbe number and the partial dispersion ratio of the first three negative lenses, the positive lens, and the negative lens bonded to each other are ν2
FN, ν2P, ν2RN, θ2FN, θ2P, θ2R
N, the Abbe number and the partial dispersion ratio of the positive lens, the negative lens, and the positive lens of the second three lenses bonded to each other are ν3FN and ν3, respectively.
Assuming that N, ν3RP, θ3FN, θ3N, θ3RP, when ν1P−ν1N = −23.6 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.0058 ν1N = 51.4 ν2P In the case of −ν2FN = 56.5> 0, (1) (θ2P−θ2FN) / (ν2P−ν2FN) 0.000897 (2) ν2P−ν2FN 56.5 (3) ν2FN 38.8 ν2P−ν2RN = 61 When 0.4> 0, (1) (θ2P−θ2RN) / (ν2P−ν2RN) 0.00145 (2) ν2P−ν2RN 61.4 (3) ν2RN 33.9 ν3FP−ν3N = −0.8 < If 0, then (4) (θ3FP−θ3N) / (ν3FP−ν3N) 0.032 ν3N = 31.6 if ν3RP−ν3N = 63.7> 0, then (1) (θ3RP−θ3N) / ( ν3RP-ν3 ) 0.00156 (2) ν3RP-ν3N 63.7 (3) ν3N 31.6

FIG. 20 is a diagram showing various aberrations of the microscope objective according to the tenth embodiment. As is clear from FIG. 20, various aberrations including chromatic aberration are well corrected.

(Eleventh Embodiment) FIG. 21 shows a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a lens configuration of a microscope objective lens according to one example. The lens according to the present example has f = 2 mm, N
A ′ = 0.5 (Fno = 1.0), and this optical system constitutes an objective lens with a magnification of 100 × when combined with the second objective lens (f = 200 mm). From the side farther away from the object point, the first doublet, the first triplet bonded lens, the second triplet, the third triplet, the second doublet, and the third doublet Includes 6 elements in total.

In the present embodiment, the two cemented lenses and the three three-
The laminated lens includes two lenses, a biconvex single lens, and a meniscus lens.

Table 11 shows values of the microscope objective lens according to the eleventh embodiment.

[0091]

[Table 11] Surface number rd nd νd θt 1 -5.03030 1.20000 1.799520 42.2 0.7538 2 1.90130 2.00000 1.805180 25.4 0.6680 3 32.21400 4.00000 1.000000 4 -7.00130 2.40000 1.784720 25.7 0.6702 5 -3.31000 1.00000 1.804400 39.6 0.7443 6 38.63400 4.00000 1.592700 35.3 0.72 7 7.71340 0.36000 1.000000 8 -51.70800 3.00000 1.433852 95.3 0.8048 9 -28.64500 1.00000 1.654120 39.7 0.7655 10 14.03050 4.00000 1.433852 95.3 0.8048 11 -15.09980 0.10000 1.000000 12 82.24000 4.00000 1.433852 95.3 0.8048 13 -9.50770 1.50000 1.654120 39.7 0.7655 14 28.01700 4.0060 1.433 0.10000 1.000000 16 116.09500 1.00000 1.654120 39.7 0.7655 17 23.19500 4.00000 1.433852 95.3 0.8048 18 -40.22900 0.10000 1.000000 19 50.50900 1.00000 1.654120 39.7 0.7655 20 15.80090 5.00000 1.433852 95.3 0.8048 21 -62.74900 0.10000 1.000000 22 30.21100 5.00000 1.487490 70.2 0.8924 2300000. 1.741000 52.7 0.8155 25 16.89600 (10.99538) 1.000000 (Conditional ) From the side farther from the object point, the Abbe number and partial dispersion ratio of the positive lens and the negative lens of the first doublet are ν1P, ν1N, θ1P and θ1N, respectively, the first three positive lenses, the negative lens, and the positive lens. The Abbe number and partial dispersion ratio of the lens are ν2FP, ν2N, ν2RP, θ2F, respectively.
P, θ2N, θ2RP, Abbe number and partial dispersion ratio of a positive lens, a negative lens, and a positive lens of the second three lenses bonded to each other are ν3FP, ν3N, ν3RP, θ3FP, θ3N,
θ3RP, the Abbe number and the partial dispersion ratio of the positive lens, the negative lens, and the positive lens,
P, ν4N, ν4RP, θ4FP, θ4N, θ4RP,
The Abbe number and the partial dispersion ratio of the positive lens and the negative lens of the second doublet are ν5P, ν5N, θ5P, θ5N,
The Abbe number and the partial dispersion ratio of the positive lens and the negative lens of the third doublet are ν6P, ν6N, θ6P, θ6N,
Then, if ν1P−ν1N = −16.8 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.0051 ν1N = 42.2 ν2FP−ν2N = 13.9 <0 , (4) (θ2FP−θ2N) / (ν2FP−ν2N) 0.00533 ν2N = 39.6 In the case of ν2RP−ν2N = −4.3 <0, (4) (θ2RP−θ2N) / (ν2RP−ν2N) 0.0054 ν2N = 39.6 ν3FP−ν3N = ν3RP−ν3N = 55.6> 0, (1) (θ3FP−θ3N) / (ν3FP−ν3N) = (θ3RP−θ3N) / (ν3RP−ν3N) 0.00071 (2) ν3FP−ν3N = ν3RP−ν3N 55.6 (3) ν3N 39.7 ν4FP−ν4N = ν4RP−ν4N = 55.6> 0, (1) (θ4FP−θ4N) / (ν4FP) ν4N) = (θ4RP−θ4N) / (ν4RP−ν4N) 0.00071 (2) ν4FP−ν4N = ν4RP−ν4N 55.6 (3) ν4N 39.7 ν5P−ν5N = 55.6> 0, 1) (θ5P−θ5N) / (ν5P−ν5N) 0.00071 (2) ν5P−ν5N 55.6 (3) ν5N 39.7 ν6P−ν6N = 55.6> 0, (1) (θ6P− θ6N) / (ν6P-ν6N) 0.00071 (2) ν6P-ν6N 55.6 (3) ν6N 39.7 FIG. 22 is a diagram showing various aberrations of the microscope objective lens according to Example 11.

As is clear from FIG. 22, chromatic aberration is well corrected up to about 2 μm, and various aberrations are also well corrected.

(Twelfth Embodiment) FIG. 23 shows a first embodiment of the present invention.
FIG. 9 is a diagram illustrating a lens configuration of a microscope objective lens according to a second example. The lens according to the present example has f = 2 mm, N
A ′ = 0.5 (Fno = 1.0), and this optical system constitutes an objective lens with a magnification of 100 × when combined with the second objective lens (f = 200 mm). It includes four bonding elements of a first doublet, a second doublet, a first three-ply bonding, and a second three-ply bonding from the side farther from the object point.

In the present embodiment, from the side farther from the object point, there are provided two cemented lenses, two cemented lenses, two biconvex single lenses, and a meniscus lens. You.

Table 12 shows values of the microscope objective lens according to the twelfth embodiment.

[0096]

[Table 12] Surface No. 1.00000 1.654120 39.7 0.7655 8 9.59641 7.00000 1.433852 95.3 0.8048 9 -8.16585 1.00000 1.654120 39.7 0.7655 10 -18.66184 0.30000 1.000000 11 181.53923 5.80000 1.433852 95.3 0.8048 12 -9.70554 1.00000 1.654120 39.7 0.7655 13 -26.34860 5.80000 1.433852 95.3 0.8048 14 00000. 1.497000 81.6 0.8236 16 -85.27406 0.20000 1.000000 17 22.19951 4.00000 1.497000 81.6 0.8236 18 157.55588 0.20000 1.000000 19 11.18292 3.60000 1.497000 81.6 0.8236 20 22.97060 (11.49987) 1.000000 (Conditional value) The Abbe number and partial dispersion ratio of the lens and the negative lens are denoted by ν1P, ν1N, θ1P, θ1N, The Abbe numbers and partial dispersion ratios of the positive lens and the negative lens constituting the doublet of No. 2 are respectively ν2P, νN, θ1P and θ2N, and the Abbe numbers of the negative lens, the positive lens and the negative lens which constitute the first three-piece laminated lens , The partial dispersion ratio is ν3F
N, ν3P, ν3RN, θ3FN, θ3P, θ3RN,
The Abbe number and the partial dispersion ratio of the positive lens, the negative lens, and the positive lens constituting the second three-element cemented lens are each represented by ν4.
FP, ν4N, ν4RP, θ4FP, θ4N, θ4R
P, if ν1P−ν1N = −26.6 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.00528 ν1N = 52.3 ν2P−ν2N = −9 <0 , (4) (θ2P−θ2N) / (ν2P−ν2N) 0.00668 ν2N = 34.7 ν3P−ν3FN = ν3P−ν3RN = 55.6> 0, (1) (θ3P−θ3FN) / (ν3P) −ν3FN) = (θ3P−θ3RN) / (ν3P−ν3RN) 0.00071 (2) ν3P−ν3FN = ν3P−ν3RN 55.6 (3) ν3FN = ν3RN 39.7 ν4FP−ν4N = ν4RP−ν4N = 55. When 6> 0, (1) (θ4FP−θ4N) / (ν4FP−ν4N) = (θ4RP−θ4N) / (ν4RP−ν4N) 0.00071 (2) ν4FP−ν4N = ν4RP−ν4N5 .6 (3) ν4N 39.7

FIG. 24 is a diagram showing various aberrations of the microscope objective lens according to Example 12. As is clear from FIG. 24, it is understood that various aberrations including chromatic aberration are well corrected.

(Thirteenth Embodiment) FIG. 25 shows a thirteenth embodiment of the present invention.
It is a figure showing the lens composition of the microscope objective lens concerning 3 examples. The lens according to the present example has f = 2 mm, N
A ′ = 0.5 (Fno = 1.0), and this optical system constitutes an objective lens with a magnification of 100 × when combined with the second objective lens (f = 200 mm). From the side farther away from the object point, five elements including the first doublet, the first three pieces, the second three pieces, the third three pieces, and the second doublet are included. .

In the present embodiment, the two cemented lenses and the three three-
It is composed of a laminated lens, a biconvex single lens, and a meniscus lens.

Table 13 shows values of the microscope objective lens according to the thirteenth embodiment.

[0101]

[Table 13] Surface number rd nd νd θt 1 -3.83205 1.00000 1.755000 52.3 0.8107 2 -2.90689 2.00000 1.784720 25.7 0.6702 3 9.62271 4.00000 1.000000 4 -19.73853 2.00000 1.784720 25.7 0.6702 5 -3.76179 1.00000 1.804400 39.6 0.7443 6 15.71201 4.00000 1.592700 35.3 0.72 -6.23890 0.10000 1.000000 8 20.00358 1.00000 1.654120 39.7 0.7655 9 6.91787 6.00000 1.433822 95.3 0.8048 10 -6.17977 2.00000 1.654120 39.7 0.7655 11 26.67835 0.10000 1.000000 12 12.62847 4.00000 1.433852 95.3 0.8048 13 41.60349 1.00000 1.654120 39.7 0.7655 14 11.43434 7.00000 1.433852 24. 16 56.45824 1.00000 1.654120 39.7 0.7655 17 11.32282 5.00000 1.433852 95.3 0.8048 18 -55.52699 0.10000 1.000000 19 19.40533 5.00000 1.516330 64.1 0.8687 20 -22.15637 0.10000 1.000000 21 11.94816 4.00000 1.741000 52.7 0.8155 22 22.52025 (10.99969) 1.000000 (Conditional value) From the Abbe numbers of the positive lens and the negative lens that constitute the first doublet ν1P partial dispersion ratio, respectively, ν1N, θ1P, θ1N, first 3
The Abbe number and partial dispersion ratio of the positive lens, the negative lens, and the positive lens constituting the laminated lens are denoted by ν2FP and ν2FP, respectively.
2N, ν2RP, θ2FP, θ2N, θ2RP, Abbe numbers and partial dispersion ratios of the negative lens, the positive lens, and the negative lens constituting the second three-member bonding are ν3FN and ν3, respectively.
P, ν3RN, θ3FN, θ3P, θ3RN, third 3
The Abbe number and partial dispersion ratio of the positive lens, the negative lens, and the positive lens constituting the laminated lens are ν4FP and ν4FP, respectively.
4N, ν4RP, θ4FP, θ4N, θ4RP, Abbe numbers and partial dispersion ratios of the positive lens, the negative lens, the positive lens constituting the second doublet are ν5P, ν5N, θ5, respectively.
P, θ5N, ν1P−ν1N = −26.6 <0, (4) (θ1P−θ1N) / (ν1P−ν1N) 0.00528 ν1N = 52.3 ν2FP−ν2N = 1−13.9 < 0, (4) (θ2FP−θ2N) / (ν2FP−ν2N) 0.00533 ν2N = 39.6 ν2RP−ν2N = −4.3 <0, (4) (θ2RP−θ2N) / (ν2RP) −ν2N) 0.0054 ν2N = 39.6 ν3P−ν3FN = ν3P−ν3RN = 55.6> 0, (1) (θ3P−θ3FN) / (ν3P−ν3FN) = (θ3P−θ3FN) / (ν3P) −ν3RN) 0.00071 (2) ν3P−ν3FN = ν3P−ν3RN 55.6 (3) ν3FN = ν3RN 39.7 ν4FP−ν4N = ν4RP−ν4N = 55.6> 0, (1) (θ4FP) −θ4N) / (ν4FP−ν4N) = (θ4RP−θ4N) / (ν4RP−ν4N) 0.00071 (2) ν4FP−ν4N = ν4RP−ν4N 55.6 (3) ν4N 39.7 ν5P−ν5N = 55. When 6> 0, (1) (θ5P-θ5N) / (ν5P-ν5N) 0.00071 (2) ν5P-ν5N 55.6 (3) ν5N 39.7

FIG. 26 is a diagram showing various aberrations of the microscope objective lens according to Example 13. As is clear from FIG. 26, it can be seen that various aberrations as well as chromatic aberration from visible light to 1.97 μ are well corrected.

[0103]

As described above, according to the present invention, 5
Effective application of various conditions to lenses suitable for each magnification, from low-magnification objectives of x to high-magnification objectives up to 100x, enables the design of the most effective super achromatizing objective with a small number of lenses It became. In addition, about 2μ from visible light
In the wavelength range up to m, excellent chromatic aberration correction, various aberrations were successfully removed, and an objective lens having a long NA and a well-balanced high NA could be achieved. Furthermore, the realization of the high-performance objective lens of the present application further expands the measurement and observation area of a normal microscope, and further increases the need for a processing machine, thereby expanding the range of application and leading to the development of the microscope. Be expected.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a lens configuration of a microscope objective lens according to a first example.

FIG. 2 is a diagram illustrating various aberrations of the microscope objective lens according to the first example.

FIG. 3 is a diagram illustrating a lens configuration of a microscope objective lens according to Example 2.

FIG. 4 is a diagram illustrating various aberrations of the microscope objective lens according to the second example.

FIG. 5 is a diagram showing a lens configuration of a microscope objective lens according to Example 3.

FIG. 6 is a diagram illustrating various aberrations of the microscope objective lens according to the third example.

FIG. 7 is a diagram showing a lens configuration of a microscope objective lens according to Example 4.

FIG. 8 is a diagram illustrating various aberrations of the microscope objective according to the fourth example.

FIG. 9 is a diagram illustrating a lens configuration of a microscope objective lens according to a fifth example.

FIG. 10 is a diagram illustrating various aberrations of the microscope objective lens according to the fifth example.

FIG. 11 is a diagram showing a lens configuration of a microscope objective lens according to Example 6.

FIG. 12 is a diagram illustrating various aberrations of the microscope objective lens according to Example 6;

FIG. 13 is a diagram showing a lens configuration of a microscope objective lens according to Example 7.

FIG. 14 is a diagram illustrating various aberrations of the microscope objective lens according to Example 7.

FIG. 15 is a diagram illustrating a lens configuration of a microscope objective lens according to Example 8;

FIG. 16 is a diagram showing various aberrations of the microscope objective lens according to Example 8;

FIG. 17 is a diagram showing a lens configuration of a microscope objective lens according to Example 9;

FIG. 18 is a diagram showing various aberrations of the microscope objective lens according to Example 9;

FIG. 19 is a diagram showing a lens configuration of a microscope objective lens according to Example 10.

FIG. 20 is a diagram showing various aberrations of the microscope objective lens according to Example 10.

FIG. 21 is a diagram showing a lens configuration of a microscope objective lens according to Example 11;

FIG. 22 is a diagram illustrating various aberrations of the microscope objective lens according to Example 11;

FIG. 23 is a diagram illustrating a lens configuration of a microscope objective lens according to Example 12;

FIG. 24 is a diagram illustrating various aberrations of the microscope objective lens according to Example 12;

FIG. 25 is a diagram showing a lens configuration of a microscope objective lens according to Example 13;

FIG. 26 is a diagram illustrating various aberrations of the microscope objective lens according to Example 13;

Claims (8)

[Claims] 1. A microscope objective lens including at least one bonded lens composed of a positive lens and a negative lens having at least one bonded surface, wherein the Abbe number of the positive lens is νP, and the F-line (λ = 486.13 nm), the refractive index of the positive lens with respect to the C line (λ = 656.28 nm) is nc convex, and the refractive index of the positive lens with respect to the t line (λ = 1013.98 nm) is nt. The partial dispersion ratio at the t-line (λ = 1013.98 nm) of the positive lens is θtP = (nc convex−nt convex) / (nF convex−nc convex), the Abbe number of the negative lens is νN, and the negative lens is Has a refractive index of nF for the F-line (λ = 486.13 nm), has a refractive index of nc for the C-line (λ = 656.28 nm) of the negative lens, and has a refractive index of nc for the C-line (λ = 656.28 nm) of the negative lens. When the refractive index with respect to 98 nm) is nt concave, and the partial dispersion ratio at the t-line (λ = 1013.98 nm) of the negative lens is θtN = (nc concave−nt concave) / (nF concave−nc concave), νP− When νN> 0, -0.0035 <(θtP-θtN) / (νP-νN) <0.003 (1) A microscope objective lens characterized by satisfying the following condition: 2. In a bonded lens including a positive lens and a negative lens and having two or more bonding surfaces, for the adjacent positive lens and the negative lens, νP−νN>
2. The objective lens for a microscope according to claim 1, wherein when 0 is satisfied, the condition of −0.0035 <(θtP−θtN) / (νP−νN) <0.003 (1) is satisfied. 3. The method according to claim 1, wherein the positive lens and the negative lens satisfy a condition of 15 <νP−νN <72 (2) and 23 <νN <71 (3). Microscope objective. 4. When the positive lens and the negative lens adjacent to the cemented lens satisfy νP−νN <0, 0.005 <(θtP−θtN) / (νP−νN) <0. The microscope objective lens according to any one of claims 1, 2, and 3, which satisfies (4). 5. The microscope objective according to claim 3, wherein the microscope objective is a Tessar type objective. 6. The microscope objective according to claim 3, wherein the microscope objective is a Gaussian objective. 7. The microscope objective lens according to claim 3, wherein the microscope objective lens is a retrofocus type objective lens having a negative refractive power on a side farthest from the object side. 8. A microscope objective lens including at least one bonded lens composed of a positive lens and a negative lens having at least one bonded surface, wherein the Abbe number of the positive lens is νP, and the F-line (λ = 486.13 nm), the refractive index of the positive lens with respect to the C line (λ = 656.28 nm) is nc convex, and the refractive index of the positive lens with respect to the t line (λ = 1013.98 nm) is nt. The partial dispersion ratio at the t-line (λ = 1013.98 nm) of the positive lens is θtP = (nc convex−nt convex) / (nF convex−nc convex), the Abbe number of the negative lens is νN, and the negative lens is Has a refractive index of nF for the F-line (λ = 486.13 nm), has a refractive index of nc for the C-line (λ = 656.28 nm) of the negative lens, and has a refractive index of nc for the C-line (λ = 656.28 nm) of the negative lens. When the refractive index with respect to 98 nm) is nt concave, and the partial dispersion ratio at the t-line (λ = 1013.98 nm) of the negative lens is θtN = (nc concave−nt concave) / (nF concave−nc concave), νP− When νN <0, the microscope objective lens satisfies the following condition: 0.005 <(θtP−θtN) / (νP−νN) <0.04 (4).