JP5624909B2 - Microscope objective lens and microscope apparatus provided with the same - Google Patents

Description

  The present invention relates to a microscope objective lens and a microscope apparatus including the same.

  Conventionally, when observing a specimen for inspection of manufactured industrial products or for cytodiagnosis by a pathologist, first, a portion that requires detailed observation by observing a wide range using a low magnification objective lens of about 10 times is used. A method is used in which detection is performed, and then the part is enlarged and observed in detail using an objective lens having a high magnification of about 40 times.

  One microscope apparatus used for such a technique is an optical microscope. However, in an optical microscope of a type in which a plurality of objective lenses are mounted on a commonly used revolver, there is a problem that the switching operation becomes complicated when the observation magnification is frequently switched. In order to solve such a problem, an objective lens having a zoom function that does not require a revolver has been proposed (see Patent Document 1).

  Another microscope apparatus is a virtual slide manufacturing apparatus. Such an objective lens for a virtual slide manufacturing apparatus is obtained by providing an objective lens having a magnification of about 10 times with a numerical aperture equivalent to that of an objective lens having a magnification of about 40 times (Patent Document 2, 3). If an image formed by such an objective lens is photographed by an image pickup device such as a CCD (Charge Coupled Device) having a large number of pixels, an image with an intermediate magnification of 10 to 40 times can be easily observed by digital zoom. .

Japanese Patent No. 4576402 JP 2010-117705 A JP 2008-185965 A

  However, since the objective lens having a zoom function as described in Patent Document 1 has a total length of 65 mm or more and is provided with a zoom cam mechanism, the size in the radial direction is large and the weight is heavy. Had the problem of being expensive.

  In addition, for the cell diagnosis performed by a pathologist, there is still a problem that the specimen is still observed with the naked eye using an optical microscope, and the virtual slide manufacturing apparatus is expensive.

  Furthermore, even if an objective lens for a virtual slide production apparatus is incorporated into an ordinary optical microscope for observation, the objective lens for the virtual slide production apparatus is expensive and generally has a total length of 85 mm or more. There is a problem that it is very difficult to incorporate it into the optical microscope.

  The present invention has been made in view of such problems of the prior art, and its object is to have a short overall length, a small radial size, a light weight, and an inexpensive digital zoom. An objective lens for a microscope is provided.

In order to achieve the above object, a microscope objective lens according to the present invention includes a front lens group having a positive refractive power and a rear lens group having a positive refractive power in order from the object side. The front group includes, in order from the object side, a first lens group including a meniscus lens component having a concave surface directed toward the object side, and at least two lens components, and has a positive refractive power. A second lens group, and a third lens group having a negative refractive power, which is configured by a meniscus lens component having a convex surface facing the object side, and the rear group is arranged in order from the object side to the object side. A fourth lens unit having a negative refractive power and a fifth lens unit having a positive refractive power, which is composed of a meniscus lens component having a concave surface facing the lens, and satisfies the following conditional expression: It is characterized by.
1.75 <n ₁
1.75 <n ₂
0.65 ≦ NA <0.7
14 mm <F <22 mm
Where n ₁ is the refractive index of the lens having the highest refractive index among the lenses constituting the first lens group, n ₂ is the refractive index of the lens having the highest refractive index among the lenses constituting the fifth lens group, NA is the numerical aperture, F is the focal length of the entire system, and the unit is mm .

Moreover, it is preferable that the objective lens for microscopes of this invention satisfies the following conditional expressions.
D <50 mm
0.25 <(h ₂ −h ₁ ) / F <0.4
Where D is the distance from the object surface to the most image side lens surface , the unit is mm ₂ , h ₂ is the height of the marginal ray when passing through the most image side surface of the rear group, and the unit is mm 2 , h ₁ Is the height of the marginal ray when passing through the most object side surface of the rear group, and its unit is mm .

Moreover, it is preferable that the objective lens for microscopes of this invention satisfies the following conditional expressions.
4.5 <D / F _f
Here, D is the distance from the object surface to the lens surface closest to the image , the unit is mm 2 , and F _f is the focal length of the front group and the unit is mm .

Moreover, it is preferable that the objective lens for microscopes of this invention satisfies the following conditional expressions.
50 mm ≦ D <65 mm
0.19 <(h ₂ −h ₁ ) / F <0.3
Where D is the distance from the object surface to the most image side lens surface , the unit is mm ₂ , h ₂ is the height of the marginal ray when passing through the most image side surface of the rear group, and the unit is mm 2 , h ₁ Is the height of the marginal ray when passing through the most object side surface of the rear group, and its unit is mm .

Moreover, it is preferable that the objective lens for microscopes of this invention satisfies the following conditional expressions.
5 <D / F _f
Here, D is the distance from the object surface to the lens surface closest to the image , the unit is mm 2 , and F _f is the focal length of the front group and the unit is mm .

  In order to achieve the above object, the microscope apparatus of the present invention includes any one of the above-described microscope objective lens, an imaging lens on which light emitted from the microscope objective lens is incident, and the imaging lens. And a solid-state imaging device that captures an image formed by the above.

  In the microscope apparatus of the present invention, it is preferable that the number of pixels of the solid-state imaging device with respect to the effective imaging region is 10 million pixels or more.

  Moreover, it is preferable that the microscope apparatus of this invention is equipped with the optical path dividing means arrange | positioned between the said imaging lens and the said solid-state image sensor.

  According to the present invention, it is possible to provide an objective lens for a microscope that has a short overall length, is small in a radial direction, is light in weight, is inexpensive, and can be used for digital zoom.

FIG. 3 is a cross-sectional view taken along the optical axis showing the configuration of the optical system and cover glass of the microscope apparatus according to Example 1 and the optical path. It is sectional drawing which follows the optical axis which shows the structure of the objective lens of the microscope apparatus shown in FIG. 1, and a cover glass, and an optical path. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. It is sectional drawing which follows the optical axis which shows the structure of the imaging lens of the microscope apparatus shown in FIG. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the imaging lens of the microscope apparatus shown in FIG. FIG. 2 is an aberration curve diagram by the optical system and cover glass of the microscope apparatus shown in FIG. 1, (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), (c) is distortion aberration, (d ) Indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration). It is sectional drawing which follows the optical axis which shows the structure and optical path of the objective lens of the microscope apparatus which concerns on Example 2, and a cover glass. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. FIG. 8 is an aberration curve diagram of the optical system and the cover glass of the microscope apparatus shown in FIG. 7, where (a) is spherical aberration, (b) is field curvature aberration (astigmatism), (c) is distortion, and (d ) Indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration). It is sectional drawing which follows the optical axis which shows the structure and optical path of the objective lens of the microscope apparatus which concerns on Example 3, and a cover glass. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. FIG. 11 is an aberration curve diagram of the optical system and the cover glass of the microscope apparatus illustrated in FIG. 10, where (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), (c) is distortion, and (d ) Indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration). It is sectional drawing which follows the optical axis which shows the structure and optical path of the objective lens of the microscope apparatus which concerns on Example 4, and a cover glass. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. It is an aberration curve diagram by the optical system and cover glass of the microscope apparatus shown in FIG. 13, (a) spherical aberration, (b) curvature of field aberration (astigmatic difference), (c) distortion, (d ) Indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration). It is sectional drawing which follows the optical axis which shows the structure of the objective lens of the microscope apparatus which concerns on Example 5, and a cover glass, and an optical path. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. It is an aberration curve diagram by the optical system and cover glass of the microscope apparatus shown in FIG. 16, (a) spherical aberration, (b) curvature of field aberration (astigmatic difference), (c) distortion, (d ) Indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration). It is sectional drawing which follows the optical axis which shows the structure and optical path of the objective lens of the microscope apparatus which concerns on Example 6, and a cover glass. It is sectional drawing which follows the optical axis which shows the detail of the lens which comprises the objective lens and cover glass of the microscope apparatus shown in FIG. FIG. 20 is an aberration curve diagram of the optical system of the microscope apparatus shown in FIG. 19, where (a) is spherical aberration, (b) is field curvature aberration (astigmatism), (c) is distortion, and (d) is an axis. External lateral aberration (coma aberration, lateral chromatic aberration) is shown. It is sectional drawing in alignment with the optical axis which shows the structure and optical path by the optical system and cover glass of microscope apparatus which concern on Example 7. FIG.

  Prior to the description of embodiments of the microscope objective lens of the present invention and the microscope apparatus using the same, the function and effect of the present invention will be described. It should be noted that when specifically describing the operational effects of the present invention, embodiments of the present invention will also be described with specific examples. However, these exemplified modes are just a part of the modes included in the present invention as in the case of the embodiments described later, and there are actually many variations. Accordingly, the present invention is not limited to those illustrated embodiments.

The objective lens for a microscope according to the present invention is an objective lens for a microscope including a front group having a positive refractive power and a rear group having a positive refractive power in order from the object side. A first lens group composed of a meniscus lens component having a concave surface facing the object side, a second lens group composed of at least two lens components and having a positive refractive power, and a convex surface facing the object side And a third lens group having a negative refractive power and a rear group consisting of a meniscus lens component with a concave surface facing the object side in order from the object side. The fourth lens group is configured to have a negative refractive power and a fifth lens group having a positive refractive power, and is configured to satisfy the following conditional expression.
1.75 <n ₁ (1)
1.75 <n ₂ (2)
0.65 ≦ NA <0.7 (3)
14 mm <F <22 mm (4)
Where n ₁ is the refractive index of the lens having the highest refractive index among the lenses constituting the first lens group, n ₂ is the refractive index of the lens having the highest refractive index among the lenses constituting the fifth lens group, and NA is The numerical aperture, F, is the focal length of the entire system, and its unit is mm .

  The microscope objective lens of the present invention has such a lens structure consisting of five groups and is configured to satisfy the conditional expressions (1) and (2). Compared with the objective lens, the lens components constituting the objective lens can be reduced, and the objective lens can be reduced in size, weight, and cost. In addition, since it is configured to satisfy the conditional expressions (3) and (4), it is possible to obtain a usable image for digital zoom by securing necessary magnification while suppressing various aberrations, and zoom function. A zoom cam mechanism or the like is not required unlike an objective lens having a zoom lens. The lens component means one cemented lens or one single lens.

  When the conditional expressions (1) and (2) are satisfied, the curvature radius of the lens that satisfies the conditional expressions is increased, the occurrence of coma is suppressed, and the flatness of the formed image is sufficiently secured. be able to. If the lower limit value of the conditional expressions (1) and (2) is not reached, even if the generated coma aberration is corrected by the entire objective lens, other aberrations deteriorate, and furthermore, the flatness of the formed image cannot be allowed. It will drop to the extent.

  Further, if the lower limit value of conditional expression (3) is not reached, the resolving power will be insufficient. On the other hand, when the value exceeds the upper limit value, large spherical aberration occurs even if the thickness of the cover glass on the specimen is within the tolerance range.

  If the lower limit of conditional expression (4) is not reached, the observation field of view cannot be ensured as much as the objective lens for an optical microscope having a low magnification of about 10 times the conventional one. On the other hand, if the upper limit is exceeded, it becomes difficult to obtain an image with a high magnification of about 40 times even by digital zoom.

Moreover, it is preferable that the objective lens for a microscope of the present invention is configured to satisfy the following conditional expression.
D <50 mm (5-1)
0.25 <(h ₂ −h ₁ ) / F <0.4 (6-1)
Or it is preferable to comprise so that the following conditional expressions may be satisfied.
50 mm ≦ D <65 mm (5-2)
0.19 <(h ₂ −h ₁ ) / F <0.3 (6-2)
However, D is the distance from the object surface to the lens surface closest to the image , the unit is mm ₂ , h ₂ is the height of the marginal ray when passing through the most image side surface of the rear group, and the unit is mm 2 , h ₁ is The height of the marginal ray when passing through the most object side surface of the rear group, and its unit is mm .

  When the total length of the objective lens satisfies the conditional expression (5-1), that is, when the distance from the object surface of the objective lens to the lens surface closest to the image is 50 mm or less, the conditional expression (6-1) If the conditional expression (5-2) is satisfied, that is, the distance from the object surface of the objective lens to the lens surface closest to the image side is 50 mm or more and 65 mm or less By configuring to satisfy the conditional expression (6-2), the Petzval sum can be improved and the flatness of the image in the effective field of view can be improved. Note that “D”, which is “distance from the object surface to the lens surface closest to the image side”, is the sum of the thickness of the cover glass, the working distance (WD), and the total length of the objective lens. This is the distance from the object side surface (object surface) of the glass to the lens surface closest to the image side of the objective lens.

  If the lower limit of conditional expressions (6-1) and (6-1) is not reached, the negative refractive power of the concave surface that is the lens surface closest to the object side in the rear group becomes weak, and the Petzval sum increases. The curvature of field becomes large, and the flatness of the image cannot be improved. On the other hand, when the value exceeds the upper limit, the height of the marginal ray when passing through the second lens group in the front group becomes low and the Petzval sum becomes large, so that the field curvature becomes large and the flatness of the image is improved. I can't.

The objective lens for a microscope of the present invention is preferably configured to satisfy the following conditional expressions when satisfying the conditional expressions (5-1) and (6-1).
4.5 <D / F _f (7-1)
Alternatively, when the conditional expressions (5-2) and (6-2) are satisfied, it is preferable that the following conditional expressions are satisfied.
5 <D / F _f (7-2)
Here, D is the distance from the object surface to the lens surface closest to the image , the unit is mm 2 , and F _f is the focal length of the front group and the unit is mm .

  When configured to satisfy the conditional expressions (7-1) and (7-2), a numerical aperture of 0.5 or more can be secured. If the lower limit value of the conditional expressions (7-1) and (7-2) is not reached, the height of the marginal ray when passing through the second lens group in the front group becomes low, and it is difficult to correct spherical aberration. become.

  A microscope apparatus according to the present invention includes any one of the above-described microscope objective lenses, an imaging lens on which light emitted from the microscope objective lens is incident, and an imaging element that captures an image formed by the imaging lens. , And so on.

  Since the objective lens for a microscope of the present invention can be manufactured at a lower cost than an objective lens for a conventional virtual slide manufacturing apparatus, a virtual slide manufacturing apparatus using the objective lens for a microscope of the present invention is a conventional one. It can be produced at a lower cost than the product.

  Moreover, it is preferable that the microscope apparatus of the present invention is configured such that the number of pixels of the imaging element with respect to the effective imaging region is 10 million pixels or more.

  When the radius of the Airy disk is equal to the pixel pitch of the image sensor, it can be said that the image and the resolution of the image sensor are balanced (Tetsuo Tsuruta, “Third Light Pencil”, New Technology Communications, 1993). Yearly issue, 31 lectures, p.387).

  In this case, if the magnification of the objective lens is 10 times and the numerical aperture is 0.65, the radius of the Airy disk of an image formed by light having a wavelength of 550 nm is 5 μm. When this is used as the pixel pitch and the number of pixels of the imaging element having a rectangular effective imaging region with a diagonal length of 22 mm and a ratio of the length of the long side to the short side of 4: 3 is calculated, the number of pixels is 8.72 million pixels. Become.

  Therefore, if a CCD having 10 million pixels or more for the effective imaging area is used, an image captured at a low magnification (for example, 10 times) is enlarged by digital zoom (for example, 4 times). The resolving power of the obtained image can be made comparable to the resolving power of an image taken with an objective lens having a high magnification (for example, 40 times).

  In general, solid-state image sensors such as CCDs have various sizes. Therefore, for example, when a 2/3 inch diagonal 11 mm is used, the image is projected by being reduced 0.5 times as compared with a 22 mm diagonal. The number of required pixels remains the same because the CCD's exit numerical aperture is doubled and the radius of the Airy disk is halved.

  Moreover, it is preferable that the microscope apparatus of the present invention includes an optical path dividing unit disposed between the imaging lens and the solid-state imaging device.

  If comprised in this way, observation with the naked eye can be performed simultaneously with the imaging for producing a virtual slide etc.

  Embodiments of a microscope apparatus using the objective lens of the present invention will be described below with reference to the drawings.

The numbers shown as subscripts in the optical system sectional views r ₁ , r ₂ ,... And d ₁ , d ₂ ,. doing.

In the numerical data, s is the surface number, r is the radius of curvature of each surface, d is the surface spacing, nd is the refractive index at the d-line (wavelength 587.56 nm), νd is the Abbe number at the d-line, and K is the cone. Coefficients A ₄ , A ₆ , A ₈ and A ₁₀ indicate aspheric coefficients, respectively.

In the aspherical coefficient of the numerical data, E represents a power of 10. For example, “E-01” represents 10 minus the first power. Each aspheric shape is expressed by the following equation using each aspheric coefficient described in the numerical data. However, the coordinate in the direction along the optical axis is Z, and the coordinate in the direction perpendicular to the optical axis is Y.
Z = (Y ² / r) / [1+ {1− (1 + k) · (Y / r) ² } ^1/2 ]
+ A ₄ Y ⁴ + A ₆ Y ⁶ + A ₈ Y ⁸ + A ₁₀ Y ¹⁰ +...

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS.

  FIG. 1 is a cross-sectional view along the optical axis showing the configuration of the optical system and cover glass of the microscope apparatus and the optical path according to the present embodiment. FIG. 2 is a cross-sectional view taken along the optical axis showing the configuration and the optical path of the objective lens and cover glass of the microscope apparatus shown in FIG. FIG. 3 is a cross-sectional view along the optical axis showing the details of the lens constituting the objective lens of the microscope apparatus shown in FIG. 4 is a cross-sectional view along the optical axis showing the configuration of the imaging lens of the microscope apparatus shown in FIG. FIG. 5 is a cross-sectional view along the optical axis showing the details of the lens constituting the imaging lens of the microscope apparatus shown in FIG. 6A and 6B are aberration curves of the optical system and the cover glass of the microscope apparatus shown in FIG. 1, where FIG. 6A is spherical aberration, FIG. 6B is field curvature aberration (astigmatic difference), and FIG. 6C is distortion. Aberration (d) indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIG. 1, the microscope apparatus of the present embodiment includes an objective lens, an imaging lens IL on which light emitted from the objective lens OL is incident, and an imaging surface that captures an image formed by the imaging lens. And an imaging device having IM. A cover glass CG is arranged on the object side of the objective lens OL.

  As shown in FIGS. 2 and 3, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ includes, in order from the object side, a lens L ₁₁ that is a biconcave lens having negative refractive power and a lens L ₁₂ that is a biconvex lens having positive refractive power. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ has a positive refractive power as a whole, and in order from the object side, a lens L ₂₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. ₂₂ , a lens L ₂₃ that is a biconvex lens having a positive refractive power, and a lens L ₂₄ that is a biconvex lens having a positive refractive power. The lens L ₂₂ and the lens L ₂₃ are cemented. In other words, the second lens group G ₂ is composed of three lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a negative refracting power as a whole, and in order from the object side, a lens L ₄₁ that is a meniscus lens having a negative refracting power with the concave surface facing the object side, and a concave surface on the object side And a lens L ₄₂ which is a meniscus lens having a positive refractive power. The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ is composed of a lens L ₅₁ which is a meniscus lens having positive refractive power as a whole and having a concave surface directed toward the object side and having positive refractive power.

As shown in FIGS. 5 and 6, the imaging lens IL has a lens L _i1 that is a biconvex lens having positive refractive power on the optical axis Lc in order from the object side, and a concave surface facing the object side. The lens includes a lens L _i2 that is a meniscus lens having a negative refractive power, a lens L _i3 that is a biconvex lens having a positive refractive power, and a lens L _i4 that is a biconcave lens having a negative refractive power. The lens L _i1 and the lens L _i2 are cemented, and the lens L _i3 and the lens L _i4 are cemented.

  The aberration diagram shown in FIG. 6 is an aberration diagram related to an image obtained when the imaging lens OL is arranged at a position 30 mm on the image side of the objective lens IL as shown in FIG. The image height is 11 mm.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 1 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.5
3 -5.71 2 1.7174 29.5
4 9.91 4 1.883 40.8
5 -9.37 0.1
6 21.93 4 1.9229 18.9
7 -14.92 1.5
8 -8.77 1.87 1.738 32.3
9 11.3 5.5 1.4388 94.9
10 -15.08 0.1
11 35.14 5 1.5691 71.3
12 -12.95 0.1
13 49.93 5.5 1.4388 94.9
14 -11.37 1.87 1.9229 18.9
15 28.58 4.7
16 -8.8 2 1.6727 32.1
17 -35.99 4.5 1.883 40.8
18 -14.82 0.1
19 -428.81 4 1.9229 18.9
20 -35.65

Various data Objective lens total length (mm) : 46.84
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.5
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of front group: 9.48

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.883
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.9229
Marginal ray height h ₁ (mm) when passing through the most object side surface of the rear group RG: 6.77
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.883
(2) 1.75 <n ₂ : 1.9229
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : 48.51
(5-2) 50 mm ≦ D <65 mm : −
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: 0.27
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: −
(7-1) 4.5 <D / F _f : 5.12
(7-2) 5 <D / F _f : −

  Next, numerical data relating to the imaging lens of the microscope apparatus of the present embodiment will be shown.

Numerical data (imaging lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 58.63 8.9 1.497 81.5
2 -66.81 3.9 1.7205 34.7
3 -877.68 6.04
4 43.62 8.9 1.7234 38
5 -115.79 3.9 1.6134 44.3
6 28

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS. The configuration of the microscope apparatus according to the present embodiment is substantially the same as that of the microscope apparatus according to the first embodiment except for the objective lens, and thus detailed description of the configuration other than the objective lens is omitted.

  FIG. 7 is a cross-sectional view along the optical axis showing the configuration and the optical path of the objective lens and cover glass of the microscope apparatus according to the present embodiment. FIG. 8 is a cross-sectional view along the optical axis showing details of the objective lens and the lens constituting the cover glass of the microscope apparatus shown in FIG. FIG. 9 is an aberration curve diagram by the optical system and cover glass of the microscope apparatus shown in FIG. 7, where (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), and (c) is distortion. Aberration (d) indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIGS. 7 and 8, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ includes, in order from the object side, a lens L ₁₁ that is a biconcave lens having negative refractive power and a lens L ₁₂ that is a biconvex lens having positive refractive power. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ has a positive refractive power as a whole, and in order from the object side, the lens L ₂₁ , which is a biconvex lens having a positive refractive power, and a negative refractive power with a concave surface facing the object side. The lens L ₂₂ is a meniscus lens having a refractive index, and the lens L ₂₃ is a biconvex lens having a positive refractive power. The lens L ₂₁ and the lens L ₂₂ are cemented. In other words, the second lens unit G ₂ is configured by two lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a negative refracting power as a whole, and in order from the object side, a lens L ₄₁ that is a biconcave lens having a negative refracting power and a lens L that is a biconvex lens having a positive refracting power. _{And 42} . The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ has a positive refracting power as a whole, and includes a plano-convex lens L ₅₁ that is convex toward the image side and has a positive refracting power.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 2 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.5
3 -8.6 2.5 1.883 40.8
4 23.24 4 1.9229 18.9
5 -11.35 0.1
6 25.99 6 1.4388 94.9
7 -7.35 3 1.738 32.3
8 -11.58 0.1
9 36.26 4.5 1.4388 94.9
10 -19.16 0.1
11 10.66 7 1.4388 94.9
12 -19.3 1.87 1.8052 25.4
13 9.64 5.56
14 -6.92 2 1.7618 26.5
15 69.89 6 1.6779 55.3
16 -13.35 0.1
17 ∞ 4.5 1.8467 23.8
18 -25.17

Various data Objective lens total length (mm) : 47.33
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.5
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of front group: 8.345

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.9229
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.8467
Marginal ray height h ₁ (mm) when passing through the most object side surface of the rear group RG: 5.46
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.9229
(2) 1.75 <n ₂ : 1.8467
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : 49.0
(5-2) 50 mm ≦ D <65 mm : −
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: 0.35
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: −
(7-1) 4.5 <D / F _f : 5.87
(7-2) 5 <D / F _f : −

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS. The configuration of the microscope apparatus according to the present embodiment is substantially the same as that of the microscope apparatus according to the first embodiment except for the objective lens, and thus detailed description of the configuration other than the objective lens is omitted.

  FIG. 10 is a cross-sectional view along the optical axis showing the configuration and optical path of the objective lens and cover glass of the microscope apparatus according to the third embodiment. FIG. 11 is a cross-sectional view along the optical axis showing details of the objective lens and the lens constituting the cover glass of the microscope apparatus shown in FIG. FIG. 12 is an aberration curve diagram of the optical system and the cover glass of the microscope apparatus shown in FIG. 10, where (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), and (c) is distortion. Aberration (d) indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIGS. 10 and 11, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ has, in order from the object side, a lens L ₁₁ that is a meniscus lens having a negative refractive power facing the object side and a positive refractive power having a concave surface facing the object side. The lens L ₁₂ is a meniscus lens. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ has a positive refractive power as a whole, and in order from the object side, a lens L ₂₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconvex lens having a positive refractive power. _{And 22} is configured. In other words, the second lens unit G ₂ is configured by two lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a negative refracting power as a whole, and in order from the object side, a lens L ₄₁ that is a biconcave lens having a negative refracting power and a lens L that is a biconvex lens having a positive refracting power. _{And 42} . The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ has a positive refractive power as a whole, and in order from the object side, a lens L ₅₁ that is a biconvex lens having a positive refractive power, and a positive refractive power directed toward the image side toward the convex surface. is composed by L ₅₂ is a plano-convex lens having.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 3 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.87
3 -7.25 2.5 1.4875 70.2
4 -37.81 4 1.8503 32.3
5 -11.95 0.18
6 933.98 4.5 1.4388 94.9
7 -11.47 0.5
8 18.3 4.5 1.4388 94.9
9 -24.07 0.1
10 10.83 6 1.4388 94.9
11 -19.32 3 1.738 32.3
12 8.64 4.5
13 -6.68 2 1.738 32.3
14 81.65 6 1.5952 67.7
15 -11.87 0.1
16 532.76 4 1.5952 67.7
17 -65.02 0.21
18 ∞ 4.2 1.8503 32.3
19 -39.15

Various data Objective lens total length (mm) : 46.29
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.87
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of front group: 7.53

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.8503
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.8503
Marginal ray height h ₁ (mm) when passing through the most object side surface of the rear group RG: 5.02
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.8503
(2) 1.75 <n ₂ : 1.8503
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : 48.33
(5-2) 50 mm ≦ D <65 mm : −
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: 0.37
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: −
(7-1) 4.5 <D / F _f : 6.42
(7-2) 5 <D / F _f : −

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS. The configuration of the microscope apparatus according to the present embodiment is substantially the same as that of the microscope apparatus according to the first embodiment except for the objective lens, and thus detailed description of the configuration other than the objective lens is omitted.

  FIG. 13 is a cross-sectional view along the optical axis showing the configuration and optical path of the objective lens and cover glass of the microscope apparatus according to the fourth embodiment. FIG. 14 is a cross-sectional view taken along the optical axis showing details of the objective lens and the lens constituting the cover glass of the microscope apparatus shown in FIG. FIG. 15 is an aberration curve diagram of the optical system and the cover glass of the microscope apparatus shown in FIG. 13, where (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), and (c) is distortion. Aberration (d) indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIGS. 13 and 14, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ includes, in order from the object side, a lens L ₁₁ that is a biconcave lens having negative refractive power and a lens L ₁₂ that is a biconvex lens having positive refractive power. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ is a meniscus lens having a positive refractive power as a whole, and in order from the object side, the object side surface is an aspheric surface, the convex surface is directed toward the object side, and has a negative refractive power. The lens L _{21 includes} a lens L ₂₂ that is a biconvex lens having a positive refractive power, and a lens L ₂₃ that is a biconvex lens having a positive refractive power. The lens L ₂₁ and the lens L ₂₂ are cemented. In other words, the second lens unit G ₂ is configured by two lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a positive refractive power as a whole, and in order from the object side, a lens L ₄₁ which is a biconcave lens having a negative refractive power and a lens L which is a biconvex lens having a positive refractive power. _{And 42} . The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ includes a lens L ₅₁ having a positive refractive power as a whole, a biconvex lens having an aspheric image side surface and a positive refractive power.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 4 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.59
3 -7.28 2.5 1.883 40.8
4 89.09 4 1.9229 18.9
5 -12.97 0.18
6 * 20.22 2.5 1.6134 44.5
7 14.13 6 1.4388 94.9
8 -12.6 0.1
9 16.93 4.5 1.4388 94.9
10 -21.09 0.1
11 15.73 6 1.4388 94.9
12 -44.01 1.87 1.8467 23.8
13 12.48 5.28
14 -7.28 2 1.738 32.3
15 23.91 6.5 1.5952 67.7
16 -20.52 0.1
17 182.24 5 1.8503 32.3
18 * -21.13
Note that the surface numbered with “*” is an aspheric surface.

Aspheric data 6th surface K = -1.0223E + 01
A ₄ = -3.8839E-06
A ₆ = -9.0298E-08
18th page K = -4.0189E-01
A ₄ = 4.5272E-06
A ₆ = 1.0812E-08

Various data Objective lens total length (mm) : 46.63
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.59
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of the front group: 8.91

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.9229
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.8503
Marginal ray height h ₁ (mm) when passing through the most object side surface of the rear group RG: 5.46
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.9229
(2) 1.75 <n ₂ : 1.8503
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : 48.39
(5-2) 50 mm ≦ D <65 mm : −
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: 0.35
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: −
(7-1) 4.5 <D / F _f : 5.43
(7-2) 5 <D / F _f : −

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS. The configuration of the microscope apparatus according to the present embodiment is substantially the same as that of the microscope apparatus according to the first embodiment except for the objective lens, and thus detailed description of the configuration other than the objective lens is omitted.

  FIG. 16 is a cross-sectional view along the optical axis showing the configuration and optical path of the objective lens and cover glass of the microscope apparatus according to the fifth embodiment. FIG. 17 is a cross-sectional view along the optical axis showing details of the objective lens and the lens constituting the cover glass of the microscope apparatus shown in FIG. 18A and 18B are aberration curves of the optical system and the cover glass of the microscope apparatus shown in FIG. 16, where FIG. 18A shows spherical aberration, FIG. 18B shows field curvature aberration (astigmatic difference), and FIG. 18C shows distortion. Aberration (d) indicates off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIGS. 16 and 17, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ includes, in order from the object side, a lens L ₁₁ that is a biconcave lens having negative refractive power and a lens L ₁₂ that is a biconvex lens having positive refractive power. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ has a positive refractive power as a whole, and in order from the object side, a lens L ₂₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. ₂₂ , a lens L ₂₃ that is a biconvex lens having a positive refractive power, and a lens L ₂₄ that is a biconvex lens having a positive refractive power. The lens L ₂₂ and the lens L ₂₃ are cemented. In other words, the second lens group G ₂ is composed of three lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a negative refracting power as a whole, and in order from the object side, a lens L ₄₁ that is a meniscus lens having a negative refracting power with the concave surface facing the object side, and a concave surface on the object side And a lens L ₄₂ which is a meniscus lens having a positive refractive power. The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ is composed of a lens L ₅₁ which is a plano-convex lens having positive refractive power as a whole and having a convex surface facing the image side and positive refractive power.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 5 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.5
3 -7.32 3 1.7174 29.5
4 20.18 5 1.883 40.8
5 -11.81 0.38
6 44.88 5.33 1.9229 18.9
7 -22.13 4.73
8 -11.81 1.87 1.738 32.3
9 35 7 1.497 81.5
10 -14.09 0.13
11 19.76 6 1.497 81.5
12 -33.54 0.37
13 25.31 8 1.4388 94.9
14 -15.22 1.87 1.9229 18.9
15 19.38 6.45
16 -10.78 2 1.4388 94.9
17 -50 5 1.755 52.3
18 -22.35 0.27
19 ∞ 4 1.9229 18.9
20 -40.26

Various data Objective lens total length (mm) : 61.40
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.5
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of the front group: 9.27

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.883
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.9229
Marginal ray height h ₁ (mm) when passing through the most object-side surface of the rear group RG: 7.44
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.883
(2) 1.75 <n ₂ : 1.9229
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : −
(5-2) 50 mm ≦ D <65 mm : 63.07
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: −
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: 0.24
(7-1) 4.5 <D / F _f : −
(7-2) 5 <D / F _f : 6.80

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIGS. The configuration of the microscope apparatus according to the present embodiment is substantially the same as that of the microscope apparatus according to the first embodiment except for the objective lens, and thus detailed description of the configuration other than the objective lens is omitted.

  FIG. 19 is a cross-sectional view along the optical axis showing the configuration and optical path of the objective lens and cover glass of the microscope apparatus according to the sixth embodiment. 20 is a cross-sectional view along the optical axis showing details of the objective lens and the lens constituting the cover glass of the microscope apparatus shown in FIG. FIG. 21 is an aberration curve diagram of the optical system of the microscope apparatus shown in FIG. 19, where (a) is spherical aberration, (b) is field curvature aberration (astigmatic difference), (c) is distortion, d) shows off-axis lateral aberration (coma aberration, lateral chromatic aberration).

  As shown in FIGS. 19 and 20, the objective lens OL includes a front group FG and a rear group RG in order from the object side on the optical axis Lc.

The front group FG has a positive refractive power as a whole, and is composed of a first lens group G ₁ , a second lens group G _2, and a third lens group G _{3 in} order from the object side.

The rear group RG has a positive refractive power as a whole, and is composed of a fourth lens group G ₄ and a fifth lens group G _{5 in} order from the object side.

The first lens group G ₁ includes, in order from the object side, a lens L ₁₁ that is a biconcave lens having negative refractive power and a lens L ₁₂ that is a biconvex lens having positive refractive power. The lens L ₁₁ and the lens L ₁₂ are cemented. That is, the first lens group G ₁ is composed of a meniscus lens component having a concave surface facing the object side.

The second lens group G ₂ has positive refractive power as a whole, and in order from the object side, a lens L ₂₁ that is a meniscus lens having a negative refractive power with a concave surface facing the object side, and positive refractive power A lens L ₂₂ that is a biconvex lens having a negative refractive power, a lens L ₂₃ that is a meniscus lens having a negative refractive power facing the object side, and a lens L ₂₄ that is a biconvex lens having a positive refractive power Has been. The lens L ₂₂ and the lens L ₂₃ are cemented. In other words, the second lens group G ₂ is composed of three lens components.

The third lens group G ₃ has a negative refractive power as a whole, and in order from the object side, a lens L ₃₁ that is a biconvex lens having a positive refractive power and a lens L that is a biconcave lens having a negative refractive power. _{And 32} . The lens L ₃₁ and the lens L ₃₂ are cemented. That is, the third lens group G ₃ is composed of a meniscus lens component having a convex surface directed toward the object side.

The fourth lens group G ₄ has a positive refractive power as a whole, and in order from the object side, a lens L ₄₁ which is a meniscus lens having a negative refractive power with a concave surface facing the object side, and a concave surface on the object side And a lens L ₄₂ which is a meniscus lens having a positive refractive power. The lens L ₄₁ and the lens L ₄₂ are cemented. That is, the fourth lens group G ₄ is configured by a meniscus lens component having a concave surface directed toward the object side.

The fifth lens group G ₅ has a positive refracting power as a whole, and includes a lens L ₅₁ that is a biconvex lens having a positive refracting power.

  Next, numerical data relating to the cover glass CG and the objective lens OL of the microscope apparatus of the present embodiment will be shown.

Numerical data 5 (cover glass and objective lens)
Unit mm
Surface data Surface number Curvature radius Surface spacing Refractive index Abbe number s r d nd νd
1 ∞ 0.17 1.521 56
2 ∞ 1.5
3 -8.35 1.5 1.755 52.3
4 13.34 4 1.738 32.3
5 -13.8 0.38
6 -35.22 6 1.4388 94.9
7 -13.46 1.65
8 242.32 7 1.4388 94.9
9 -10.75 3 1.5688 56.4
10 -15.85 1.36
11 19.96 6 1.497 81.5
12 -69.84 0.37
13 16.31 8 1.4388 94.9
14 -24.09 1.87 1.738 32.3
15 11.1 7.5
16 -9.97 2 1.7174 29.5
17 -53.34 6 1.618 63.3
18 -16.48 0.27
19 447.48 4.5 1.8081 22.8
20 -40.35

Various data Objective lens total length (mm) : 61.40
Cover glass thickness (mm) : 0.17
Working distance (WD): 1.5
NA : 0.65
Focal length F (mm) : 18
Focal length F _f (mm) of front group: 11.05

Refractive index of the highest refractive index lens data first lens group G within ₁ according to the condition n _1: 1.755
Refractive index n _{2 of the} lens having the highest refractive index in the fifth lens group G ₅ : 1.8081
Marginal ray height h ₁ (mm) when passing through the most object-side surface of the rear group RG: 7.04
Marginal ray height h ₂ (mm) when passing through the most image side surface of the rear group RG: 11.7

Conditional expression (1) 1.75 <n ₁ : 1.755
(2) 1.75 <n ₂ : 1.8081
(3) 0.65 ≦ NA <0.7 : 0.65
(4) 14 mm <F <22 mm : 18
(5-1) D <50 mm : −
(5-2) 50 mm ≦ D <65 mm : 63.07
(6-1) 0.25 <(h ₂ −h ₁ ) / F <0.4: −
(6-2) 0.19 <(h ₂ −h ₁ ) / F <0.3: 0.26
(7-1) 4.5 <D / F _f : −
(7-2) 5 <D / F _f : 5.71

  The microscope apparatus according to the present embodiment will be described in detail with reference to FIG. In the configuration of the microscope apparatus of the present embodiment, the configurations of the objective lens and the imaging lens are substantially the same as those of the microscope apparatus of the first embodiment. Omitted.

  FIG. 22 is a cross-sectional view along the optical axis showing the configuration and optical path of the optical system of the microscope apparatus according to the seventh embodiment.

  In the microscope apparatus of the present embodiment, an optical path dividing prism P, which is an optical path dividing means, is disposed between the imaging lens OL and the imaging plane IM of the image sensor. Further, by arranging the eyepiece optical system OC on the optical path divided by the optical path dividing prism P, light from the specimen can be guided to the observer eyeball E. As a result, in this microscope apparatus, it is possible to simultaneously perform both photographing of an image with an image sensor and observation with the naked eye.

  Needless to say, the objective lens used in the microscope apparatus of the present embodiment is not limited to the objective lens shown in the first embodiment, and may be any objective lens according to the present invention. Further, the eyepiece optical system OC may not be arranged and may be configured as a CCD dedicated machine. Furthermore, the optical path dividing means is not limited to a prism, and a half mirror or the like may be used.

  Moreover, you may comprise the objective lens for microscopes of this invention, and the microscope apparatus using the same as follows.

  The lenses constituting the microscope objective lens are not limited to the shapes and the numbers shown in the above embodiments.

  In addition, although not arranged in each of the above embodiments, a low-pass filter or the like having an IR cut coat may be arranged between the imaging lens and the imaging surface of the imaging element.

  Although not shown in the above embodiments, the number of pixels of the image sensor is preferably 10 million pixels or more.

  Moreover, the cover glass which can be used for the microscope apparatus of a present Example is not limited to what was shown in said each Example.

CG cover glass E observer eye IL imaging lens FG front group RG rear group G ₁ first lens group G ₂ second lens group G ₃ third lens group G ₄ fourth lens group LC optical axes L ₁₁ , L ₁₂ , L ₂₁ , L ₂₂ , L ₂₃ , L ₂₄ , L ₃₁ , L ₃₂ , L ₄₁ , L ₄₂ , L ₅₁ , L ₅₂ , _{Li 1} , _{Li 2} , _{Li 3} , _{Li 4} lens OC eyepiece OL objective lens P optical path Split prism

Claims (8)

In order from the object side, in the microscope objective lens comprising a front group having a positive refractive power and a rear group having a positive refractive power,
The front group includes, in order from the object side, a first lens group that includes a meniscus lens component having a concave surface facing the object side, and a first lens group that includes at least two lens components and has a positive refractive power. A second lens group, and a third lens group having a negative refractive power and composed of a meniscus lens component having a convex surface facing the object side,
The rear group is composed of a meniscus lens component having a concave surface facing the object side in order from the object side, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power; Consists of
A microscope objective lens characterized by satisfying the following conditional expression:
1.75 <n ₁
1.75 <n ₂
0.65 ≦ NA <0.7
14 mm <F <22 mm
Where n ₁ is the refractive index of the lens having the highest refractive index among the lenses constituting the first lens group, n ₂ is the refractive index of the lens having the highest refractive index among the lenses constituting the fifth lens group, NA is the numerical aperture, F is the focal length of the entire system, and the unit is mm . The objective lens for a microscope according to claim 1, wherein the following conditional expression is satisfied.
D <50 mm
0.25 <(h ₂ −h ₁ ) / F <0.4
Where D is the distance from the object surface to the most image side lens surface , the unit is mm ₂ , h ₂ is the height of the marginal ray when passing through the most image side surface of the rear group, and the unit is mm 2 , h ₁ Is the height of the marginal ray when passing through the most object side surface of the rear group, and its unit is mm . The objective lens for a microscope according to claim 2, wherein the following conditional expression is satisfied.
4.5 <D / F _f
Here, D is the distance from the object surface to the lens surface closest to the image , the unit is mm 2 , and F _f is the focal length of the front group and the unit is mm . The objective lens for a microscope according to claim 1, wherein the following conditional expression is satisfied.
50 mm ≦ D <65 mm
0.19 <(h ₂ −h ₁ ) / F <0.3
Where D is the distance from the object surface to the most image side lens surface , the unit is mm ₂ , h ₂ is the height of the marginal ray when passing through the most image side surface of the rear group, and the unit is mm 2 , h ₁ Is the height of the marginal ray when passing through the most object side surface of the rear group, and its unit is mm . The objective lens for a microscope according to claim 4, wherein the following conditional expression is satisfied.
5 <D / F _f
Here, D is the distance from the object surface to the lens surface closest to the image , the unit is mm 2 , and F _f is the focal length of the front group and the unit is mm .   A microscope objective lens according to any one of claims 1 to 5, an imaging lens on which light emitted from the microscope objective lens is incident, and an image formed by the imaging lens And a microscope device.   The microscope apparatus according to claim 6, wherein the number of pixels of the imaging element with respect to an effective imaging region is 10 million pixels or more.   The microscope apparatus according to claim 6 or 7, further comprising: an optical path dividing unit disposed between the imaging lens and the imaging element.

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