Objective lens device and microscope observation device

Abstract

To provide an objective lens device capable of exhibiting excellent imaging performance even when there are significant changes in the immersion liquid and the thickness or optical properties of a container on which a sample is placed.SOLUTION: An objective lens device 1 includes: a first movable lens group A provided to be movable in the optical axis direction; a first correction device Ac that corrects axial chromatic aberration by moving the first movable lens group A in the optical axis direction; a second movable lens group B provided to be movable in the optical axis direction; and a second correction device Bc that moves the second movable lens group B in the optical axis direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a microscope objective lens and a microscope observation apparatus.

Background Art

[0002] Currently, cell aggregates obtained by three-dimensionally culturing cells and research using cell aggregates have attracted attention. In recent years, cell aggregates are photographed using a microscope apparatus, and screening for drug discovery is performed using image analysis technology on the acquired microscope image data to evaluate the drug efficacy (Patent Documents 1 to 2).

[0003] When performing deep imaging of an observation object as described above, an immersion objective lens is often used to suppress the occurrence of spherical aberration due to refractive index mismatch, and observation is often performed with an inverted microscope. An immersion objective lens suitable for such applications is known (Patent Documents 3 to 6).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] Incidentally, in screening studies, containers with multiple wells arranged in a matrix for containing samples (called well plates, microplates, etc.; hereinafter referred to as well plates in this specification) are sometimes used. By using such containers, a large number of samples with different conditions can be easily prepared. Many such well plates have been disclosed, for example, in Patent Document 1.

[0007] Observing a sample contained in a well plate presents several challenges compared to observing a sample placed on a conventional coverslip.

[0008] First, most well plates are made from materials such as acrylic, polyethylene, and polystyrene, and a wide variety of shapes are available. In other words, there is variation in the shape (especially the thickness) of the well plates, and this variation can lead to changes in optical performance.

[0009] Furthermore, polymer materials such as polystyrene exhibit greater variations in optical properties and thickness compared to glass due to subtle differences in material composition and differences in injection molding process conditions (Non-Patent Document 1).

[0010] These differences in thickness and optical properties primarily alter spherical aberration and chromatic aberration (Non-Patent Literature 2). This aberration change can prevent sufficient imaging performance from being achieved, leading to the problem of being unable to perform the desired observations.

[0011] In addition, when using immersion objective lenses, it is sometimes necessary to use different immersion solutions. Using different immersion solutions changes the refractive index and Abbe number, which in turn changes spherical aberration and chromatic aberration.

[0012] Below, we will examine existing immersion objective lenses in detail, keeping the above issues in mind.

[0013] Patent Document 3 discloses an objective lens that corrects spherical aberration and chromatic aberration by moving a portion of the lens group along the optical axis when the immersion liquid changes in which at least one of the refractive index and Abbe number differs by 5% or more. However, this method corrects spherical aberration and chromatic aberration simultaneously, so it has the problem that precise correction cannot be achieved when the immersion liquid changes in which the refractive index is the same but the Abbe number is different. This situation corresponds, for example, to the case where immersion liquid A and immersion liquid E listed in Patent Document 3 are used interchangeably, but the correction method in that case is not disclosed.

[0014] Patent Document 4 discloses an objective lens that can appropriately move multiple lens groups and select a state with appropriate aberration correction in response to changes in cover glass thickness, temperature, and immersion liquid. However, this method moves each lens group simultaneously, and while it can handle a few patterns anticipated during the design phase, it has the problem of not being able to handle other cases.

[0015] Patent Document 5 discloses an objective lens that corrects spherical aberration and chromatic aberration by inserting and removing appropriate parallel plane plates depending on the immersion liquid. However, while this method allows for discrete adjustment for a specific immersion liquid, it cannot be applied to immersion liquids with unknown optical properties that were not anticipated during the design phase. Furthermore, it does not take into account changes in the optical properties of the container on which the sample is placed. In addition, it is necessary to secure space on the sample side to hold the parallel plane plates, which leads to the challenge of increasing the size of the objective lens.

[0016] In Patent Document 6, an objective lens is disclosed that performs aberration correction by inserting and removing a correction lens according to the presence or absence of a cover glass. However, in this method, although changes between two states of whether there is a cover glass or not can be handled, there is a problem that it cannot handle cases where there is a cover glass and the thickness is different.

[0017] The present invention has been made in view of such a situation, and an object thereof is to provide an objective lens device that can exhibit good imaging performance even when there are large changes in the immersion liquid and in the thickness and optical characteristics of the container on which the sample is placed.

Means for Solving the Problems

[0018] In order to solve the above problems, one aspect of the present invention is an objective lens device, comprising: a first movable lens group (A) movable in the optical axis direction; a first correction device (Ac) that corrects axial chromatic aberration by moving the first movable lens group in the optical axis direction; a second movable lens group (B) movable in the optical axis direction; and a second correction device (Bc) that corrects spherical aberration by moving the second movable lens group in the optical axis direction.

[0019] According to this aspect, since different aberrations can be corrected by each of the first correction device and the second correction device, even when there are large changes in the immersion liquid and in the thickness and optical characteristics of the container on which the sample is placed, the imaging performance of the objective lens device can be improved.

[0020] In the above aspect, the first movable lens group (A) may be composed of a cemented lens formed by cementing a plano-convex lens (A1) and a plano-concave lens (A2).

[0021] According to this aspect, the first movable lens group can be realized with a simple lens configuration.

[0022] In the above aspect, it is preferable that the plano-convex lens (A1) and the plano-concave lens (A2) satisfy the following conditional expressions (1) and (2). |n1-n2|<0.05 ···(1) |v1-v2|>10 ···(2) however, n1: Refractive index of the plano-convex lens (A1) at the reference wavelength n2: Refractive index of the plano-concave lens (A2) at the reference wavelength v1: Abbe number of the plano-convex lens (A1) v2: This is the Abbe number of the plano-concave lens (A2).

[0023] According to this embodiment, the imaging performance of the objective lens device can be improved when there are large changes in the immersion liquid and the thickness and optical properties of the container on which the sample is placed.

[0024] To solve the above problems, another aspect of the present invention is a microscope observation apparatus (100) comprising: an objective lens apparatus (1) having a configuration comprising: a first movable lens group (A), a first correction device (Ac), a second movable lens group (B), and a second correction device (Bc); a control device (20) that controls the first correction device (Ac) and the second correction device (Bc) of the objective lens apparatus; an imaging lens (2) that forms an image of the objective lens apparatus; and an image acquisition apparatus (3) that acquires the image formed by the imaging lens, wherein the control device calculates a correction amount from the image data acquired by the image acquisition apparatus and controls the first correction device and the second correction device based on the calculated correction amount.

[0025] According to this embodiment, axial chromatic aberration can be corrected by the first correction device, and spherical aberration can be corrected by the second correction device. Therefore, even when there are large changes in the immersion liquid and the thickness and optical properties of the container on which the sample is placed, the imaging performance of the objective lens device can be improved. [Effects of the Invention]

[0026] According to the above embodiments, an objective lens device and microscope observation device can be realized that can individually correct spherical aberration and chromatic aberration, and obtain good imaging performance, even when the thickness and optical properties of the container on which the sample is placed change, or when the immersion liquid changes. [Brief explanation of the drawing]

[0027] [Figure 1] Configuration diagram showing the objective lens device of this embodiment [Figure 2] This figure shows the spherical aberration at the reference wavelength in the objective lens device according to Example 1, both in the normal state and in the state where the movable lens group is moved. [Figure 3] This figure shows the change in axial chromatic aberration when the movable lens group is moved from the normal state in the objective lens device according to Example 1. [Figure 4] Optical path diagram of Example 1 [Figure 5] Longitudinal aberration diagram of the first state in Example 1 [Figure 6] Longitudinal aberration diagram of the second state in Example 1 [Figure 7] Longitudinal aberration diagram of the third state in Example 1 [Figure 8] Transverse aberration diagram of the first state in Example 1 [Figure 9] Transverse aberration diagram of the second state in Example 1 [Figure 10] Transverse aberration diagram of the third state in Example 1 [Figure 11] Optical path diagram of Example 2 [Figure 12] Longitudinal aberration diagram of the first state in Example 2 [Figure 13] Longitudinal aberration diagram of the second state in Example 2 [Figure 14] Longitudinal aberration diagram of the third state in Example 2 [Figure 15] Transverse aberration diagram of the first state in Example 2 [Figure 16] Transverse aberration diagram of the second state in Example 2 [Figure 17] Transverse aberration diagram of the third state in Example 2 [Figure 18] Optical path diagram of Example 3 [Figure 19]Longitudinal aberration diagram of the first state in Example 3 [Figure 20] Longitudinal aberration diagram of the second state in Example 3 [Figure 21] Longitudinal aberration diagram of the third state in Example 3 [Figure 22] Transverse aberration diagram of the first state in Example 3 [Figure 23] Transverse aberration diagram of the second state in Example 3 [Figure 24] Transverse aberration diagram of the third state in Example 3 [Figure 25] Schematic diagram of the microscope observation apparatus in Example 4 [Modes for carrying out the invention]

[0028] First, an objective lens device 1 according to one embodiment of the present invention will be described.

[0029] As shown in Figure 1, the objective lens device 1 comprises an optical system 10 consisting of multiple lenses constituting the objective lens, and a lens barrel 11 that holds this optical system 10. The objective lens device 1 is equipped with a first movable lens group A in the optical system 10 that is movable in the optical axis direction. The objective lens device 1 can correct axial chromatic aberration by moving the first movable lens group A in the optical axis direction using a first correction device Ac. The first correction device Ac is a drive device that moves the first movable lens group A relative to the lens barrel 11.

[0030] Furthermore, the objective lens device 1 is equipped with a second movable lens group B in the optical system 10 that is movable in the optical axis direction. The objective lens device 1 can correct spherical aberration by moving the second movable lens group B in the optical axis direction using a second correction device Bc. The second correction device Bc is a drive device that moves the second movable lens group B relative to the lens barrel 11.

[0031] Thus, the objective lens device 1 is equipped with two movable lens groups, A and B, consisting of a first movable lens group A that corrects axial chromatic aberration and a second movable lens group B that corrects spherical aberration. By moving each of these groups individually, axial chromatic aberration and spherical aberration can be corrected individually. This enables flexible aberration correction.

[0032] The first corrector Ac and the second corrector Bc are implemented, for example, by corrector rings. Alternatively, they may be implemented by moving each movable lens group A and B with an electric actuator. When using electric actuators, flexible control becomes possible by electrically connecting them to a microscope system equipped with a computer.

[0033] The first movable lens group A is composed of a cemented lens formed by joining a plano-convex lens A1 and a plano-concave lens A2. In this case, the plano-convex lens A1 and the plano-concave lens A2 satisfy the following conditions (1) and (2). |n1-n2|<0.05 ···(1) |v1-v2|>10 ···(2) However, n1 is the refractive index of the plano-convex lens A1 at the reference wavelength, n2 is the refractive index of the plano-concave lens A2 at the reference wavelength, v1 is the Abbe number of the plano-convex lens A1, and v2 is the Abbe number of the plano-concave lens A2.

[0034] More preferably, the plano-convex lens A1 and the plano-concave lens A2 should satisfy the following conditions (3) and (4). |n1-n2|<0.01 ···(3) |v1-v2|>20 ···(4)

[0035] The above equation means joining two types of glass materials that have nearly equal refractive indices at the reference wavelength but different Abbe numbers. By using this configuration, it becomes possible to selectively change the axial chromatic aberration.

[0036] Now, let's consider moving the first movable lens group A along the optical axis and changing the height of the light rays incident on the first movable lens group A. In this case, the first movable lens group A can be considered as a parallel plane plate with respect to the reference wavelength, so the aberration is not affected even if the light ray height changes. However, the first movable lens group A has power with respect to wavelengths other than the reference wavelength, so the axial chromatic aberration changes with the change in light ray height.

[0037] The aberration correction method of the present invention will be explained using a specific example.

[0038] Figure 2 shows the spherical aberration at the reference wavelength superimposed on the objective lens device 1 according to Embodiment 1, described later, in both the normal state and the state in which the first movable lens group A is moved (moved state). As can be seen from Figure 2, the spherical aberration at the reference wavelength hardly changes even when the first movable lens group A is moved.

[0039] Figure 3 shows the effect on chromatic aberration, specifically the change in axial chromatic aberration (focus shift), when the first movable lens group A is moved from the normal state in the objective lens device 1 according to Example 1. As can be seen from Figure 3, the axial chromatic aberration changes significantly when the first movable lens group A is moved.

[0040] As shown in Figures 2 and 3, by moving the first movable lens group A, it is possible to change the axial chromatic aberration without significantly altering the spherical aberration at the reference wavelength.

[0041] By incorporating a spherical aberration correction function into the second movable lens group B, it becomes possible to effectively correct both spherical aberration and axial chromatic aberration.

[0042] Next, we will describe an observation method, which is another aspect of the present invention.

[0043] Observation method is shown in the diagram. 25 This is embodied by the observation device exemplified in the third embodiment. As will be explained in detail in the third embodiment, the observation device is a microscope observation device 100, which comprises a microscope body 15 equipped with at least one objective lens device 1, and a control device 20 for controlling the microscope body 15. The microscope body 15 further comprises an imaging lens 2 and an image acquisition device 3. The objective lens device 1 includes a first correction device Ac (Figure 1) for correcting axial chromatic aberration and a second correction device Bc (Figure 1) for correcting spherical aberration.

[0044] The control device 20 comprises an objective lens correction device control device 21, a microscope control device 22, and a computing terminal 23. The computing terminal 23 calculates the amount of residual aberration based on the image information acquired by the image acquisition device 3. At this time, the computing terminal 23 may use a resolution chart or the like as the object of observation. The computing terminal 23 calculates the amount of image point displacement and residual aberration from the image, and based on this, the objective lens correction device control device 21 calculates the amount of movement of each movable lens group A and B. Based on this, the control device 20 drives the first correction device Ac and the second correction device Bc through the microscope control device 22, thereby obtaining a state in which good imaging performance is achieved.

[0045] Thus, according to the present invention, even when the thickness and optical properties of the container 6 on which the sample is placed change, or when the immersion liquid changes, spherical aberration and chromatic aberration can be individually corrected, and an objective lens device 1 and microscope observation device 100 can be realized that can obtain good imaging performance.

[0046] The following describes several embodiments of the objective lens device 1 of the present invention. Figures 4 to 10 and Tables 1 to 4 show Embodiment 1, Figures 11 to 17 and Tables 5 to 8 show Embodiment 2, Figures 18 to 24 and Tables 9 to 12 show Embodiment 3, and Figure 25 shows Embodiment 4.

[0047] Tables 1 and 5 show the lens data for objective lens device 1. Tables 2 and 6 show basic data such as the focal length of objective lens device 1. Unless otherwise specified, the specifications are values ​​at the reference wavelength. Tables 3 and 7 show the immersion data used in objective lens device 1. The "immersion data" shows the refractive index and Abbe number of each immersion solution. Tables 4 and 8 show the variable interval data for objective lens device 1. The "variable interval data" shows the variable interval values ​​associated with the change from the first to the third state.

[0048] In all the specifications listed below, the units of focal length, radius of curvature, lens plane spacing, and other lengths shall be millimeters (mm) unless otherwise specified. However, since equivalent optical performance can be obtained with proportional magnification and proportional reduction in an optical system, this is not the only option. [Examples]

[0049] Figure 4 shows the optical path diagram of the objective lens device 1 of Embodiment 1. Figures 5 to 7 show the longitudinal aberration diagrams of the first to third states of the objective lens device 1, and Figures 8 to 10 show the transverse aberration diagrams of the first to third states of the objective lens device 1.

[0050] The objective lens apparatus 1 according to Example 1 consists of a first fixed lens group FA, a first movable lens group A, a second fixed lens group FB, a second movable lens group B, and a third fixed lens group FC. The first fixed lens group FA consists of multiple lens components, including a cemented lens (a first lens component L1 (a cemented lens) and a second lens component L2 (a single lens), both consisting of concave meniscus lenses). Here, a lens component means a single lens consisting of a cemented lens or a single lens. The first movable lens group A consists of a cemented lens (third lens component L3) formed by joining a plano-convex lens A1 and a plano-concave lens A2. The second fixed lens group FB consists of a cemented lens (a fourth lens component L4 consisting of a convex meniscus lens). The second movable lens group B consists of two cemented lenses (fifth lens component L5 and sixth lens component L6) that each form a biconvex lens. The third fixed lens group FC is composed of multiple lenses, including a cemented lens (the seventh lens component L7 consisting of a biconvex lens, the eighth lens component L8 consisting of a convex meniscus lens, and the ninth lens component L9).

[0051] The second movable lens group B is movable in the direction of the optical axis. Making the lens group with a high ray height movable is effective in correcting spherical aberration.

[0052] Furthermore, the light rays emitted from the second movable lens group B are approximately afocal. This configuration makes it possible to suppress changes in axial chromatic aberration when the second movable lens group B is moved.

[0053] The first corrector Ac moves the first movable lens group A along the optical axis. The second corrector Bc moves the second movable lens group B along the optical axis.

[0054] The object being observed is placed on a polystyrene well plate. However, only the bottom of the well is shown in the optical path diagram in Figure 4.

[0055] The gap between the well plate and the objective lens device 1 is filled with immersion fluid.

[0056] The first state is the standard state, in which a well plate of a predetermined thickness and a predetermined immersion liquid are used. The standard wavelength is the d-ray. The second state is in which a different immersion liquid is used than in the first state. Furthermore, the third state is in which the well plate thickness is different from that of the second state.

[0057] The lens data for Example 1 is shown below. Note that all glass materials starting with "S-" are Ohara's glass names. Also, POLYSTYR refers to polystyrene. [Table 1] [Table 2] [Table 3] [Table 4]

[0058] The longitudinal aberration diagrams for the first to third states of the objective lens device 1 in Example 1 are shown in Figures 5 to 7. The transverse aberration diagrams for the first to third states of the objective lens device 1 in Example 1 are shown in Figures 8 to 10. [Examples]

[0059] Figure 11 shows the optical path diagram of the objective lens device 1 of Embodiment 2. Figures 12 to 14 show the longitudinal aberration diagrams of the first to third states of the objective lens device 1, and Figures 15 to 17 show the transverse aberration diagrams of the first to third states of the objective lens device 1.

[0060] The objective lens device 1 according to Embodiment 2 consists of a second movable lens group B and a first fixed lens group FA. The first movable lens group A is provided within the second movable lens group B. As the second movable lens group B moves in the optical axis direction, the first movable lens group A also moves together with it.

[0061] The second movable lens group B is composed of four cemented lenses (11th lens component L11 consisting of a concave meniscus lens, 12th lens component L12 consisting of a flat lens, 13th lens component L13 consisting of a concave meniscus lens, and 14th lens component L14 consisting of a plano-convex lens). The first movable lens group A is composed of a cemented lens (12th lens component L12) formed by joining a plano-convex lens A1 and a plano-concave lens A2. The first fixed lens group FA is composed of multiple lenses including a cemented lens (15th lens component L15 consisting of a biconvex lens, and 16th, 17th, and 18th lens components L16, 17th, and 18th lens components L18, all consisting of convex meniscus lenses).

[0062] When the first movable lens group A is moved in the direction of the optical axis to correct axial chromatic aberration, the second movable lens group B remains fixed.

[0063] The first corrector Ac moves the first movable lens group A along the optical axis. The second corrector Bc moves the second movable lens group B along the optical axis.

[0064] The first movable lens group A is composed of a cemented lens formed by joining a plano-convex lens A1 and a plano-concave lens A2.

[0065] The object being observed is placed on a polystyrene well plate. However, only the bottom of the well is shown in the optical path diagram in Figure 11.

[0066] The gap between the well plate and the objective lens device 1 is filled with immersion fluid.

[0067] The first state is the standard state, in which a well plate of a predetermined thickness and a predetermined immersion liquid are used. The standard wavelength is the d-ray. The second state is in which a different immersion liquid is used than in the first state. Furthermore, the third state is in which the well plate thickness is different from that of the second state.

[0068] The lens data for Example 2 is shown below. Note that all glass materials beginning with "S-" are Ohara's glass names. Also, POLYSTYR refers to polystyrene. [Table 5] [Table 6] [Table 7] [Table 8]

[0069] The longitudinal aberration diagrams for the first to third states of the objective lens apparatus 1 in Example 2 are shown in Figures 12 to 14. The transverse aberration diagrams for the first to third states of the objective lens apparatus 1 in Example 2 are shown in Figures 15 to 17. [Examples]

[0070] Figure 18 shows the optical path diagram of the objective lens device 1 of Embodiment 3. Figures 19 to 21 show the longitudinal aberration diagrams of the first to third states of the objective lens device 1, and Figures 22 to 24 show the transverse aberration diagrams of the first to third states of the objective lens device 1.

[0071] The objective lens device 1 according to Example 3 consists of a first fixed lens group FA, a second movable lens group B, a first movable lens group A, and a second fixed lens group FB. The first fixed lens group FA consists of a 21st lens component L21 consisting of a cemented lens. The second movable lens group B consists of a 22nd lens component L22 consisting of a meniscus lens having the same curvature on both sides. The first movable lens group A consists of a cemented lens (23rd lens component L23) formed by joining a plano-convex lens A1 and a plano-concave lens A2. The second fixed lens group FB consists of a plurality of lenses including a cemented lens (24th lens component L24 consisting of a cemented lens, 25th lens component L25 consisting of a cemented lens, 26th lens component L26 consisting of a cemented lens, 27th lens component L27 consisting of a biconvex lens, 28th lens component L28 consisting of a convex meniscus lens, and 29th lens component L29 consisting of parallel plane plates).

[0072] When the first movable lens group A is moved in the direction of the optical axis to correct axial chromatic aberration, the second movable lens group B remains fixed.

[0073] The first corrector Ac moves the first movable lens group A along the optical axis. The second corrector Bc moves the second movable lens group B along the optical axis.

[0074] The first movable lens group A is composed of a cemented lens formed by joining a plano-convex lens A1 and a plano-concave lens A2.

[0075] The second movable lens group B is composed of meniscus lenses, with both sides having the same curvature. This configuration effectively eliminates the power of the second movable lens group B, making it possible to selectively change spherical aberration without significantly affecting axial chromatic aberration.

[0076] The object being observed is placed on a polystyrene well plate. However, only the bottom of the well is shown in the optical path diagram in Figure 18.

[0077] The gap between the well plate and the objective lens device 1 is filled with immersion fluid.

[0078] The first state is the standard state, in which a well plate of a predetermined thickness and a predetermined immersion liquid are used. The standard wavelength is the d-ray. The second state is in which a different immersion liquid is used than in the first state. Furthermore, the third state is in which the well plate thickness is different from that of the second state.

[0079] The lens data for Example 2 is shown below. Note that all glass materials beginning with "S-" are Ohara's glass names. Also, POLYSTYR refers to polystyrene. [Table 9] [Table 10] [Table 11] [Table 12] [Examples]

[0080] figure 25 This is a schematic diagram illustrating the concept of the microscope observation device 100 according to the present invention. The microscope observation device 100 comprises at least an objective lens device 1, an objective lens correction device control device 21 that controls the objective lens correction device, and an image acquisition device 3. The objective lens device 1 also comprises a first correction device Ac that corrects axial chromatic aberration and a second correction device Bc that corrects spherical aberration.

[0081] The sample S that the microscope observation device 100 observes is, for example, cultured cells contained in a container 6 such as a well plate.

[0082] The transmitted illumination system 5 illuminates the sample S placed on the stage 7 from above the stage 7.

[0083] As shown in the figure, below the stage 7, multiple objective lens devices 1 are provided so that they can be switched using a revolving nosepiece 8. The objective lens devices 1, in combination with the imaging lens 2, form an optical image of the sample S.

[0084] The optical image of sample S is acquired as an image by the image acquisition device 3.

[0085] The control device 20 preferably includes a computing terminal 23 (for example, a computer) to which images acquired by the image acquisition device 3 are output.

[0086] The first correction device Ac and the second correction device Bc, which are installed in the objective lens device 1, are controlled from the computing terminal 23 via the microscope control device 22. Based on the image data acquired by the image acquisition device 3, a state in which good imaging performance is achieved can be obtained with an appropriate amount of correction. [Explanation of symbols]

[0087] 1: Objective lens device 2: Imaging lens 3: Image acquisition device 5: Transmitted illumination system 6: Container 7: Stage 8: Revolver 15: Microscope body 20: Control device 21: Objective lens correction device control unit 22: Microscope control device 23: Computing terminal 100: Microscope observation device A: First movable lens group A1: Plano-convex lens A2: Plano-concave lens Ac: 1st correction device B: Movable lens group Bc:Second correction device FA: First fixed lens group FB: Second fixed lens group FC: Third fixed lens group S: Sample

Claims

1. An objective lens device, A first movable lens group is provided so as to be movable in the optical axis direction, A first correction device that corrects axial chromatic aberration without significantly changing the spherical aberration of the reference wavelength by moving the first movable lens group in the optical axis direction, A second movable lens group is provided so as to be movable in the optical axis direction, The system includes a second correction device that corrects spherical aberration without significantly altering axial chromatic aberration by moving the second movable lens group in the optical axis direction, The first movable lens group is composed of a bonded lens formed by joining a plano-convex lens and a plano-concave lens. The plano-convex lens and the plano-concave lens satisfy the following conditions (1) and (2) in the objective lens device. |n1-n2|<0.05...(1) |v1-v2|>10...(2) however, n1: Refractive index of the plano-convex lens at the reference wavelength n2: Refractive index of the plano-concave lens at the reference wavelength v1: Abbe number of the plano-convex lens v2: This is the Abbe number of the plano-concave lens.

2. The objective lens device according to Claim 1, wherein the objective lens device is an immersion objective lens whose leading edge surface on the sample side is flat, and the first movable lens group and the second movable lens group are arranged in positions that form a surface other than the leading edge surface.

3. A microscope observation device, The objective lens device according to claim 1 or 2, A control device for controlling the first correction device and the second correction device of the objective lens device, An imaging lens that forms an image of the objective lens device, The device includes an image acquisition device that acquires an image formed by the imaging lens, A microscope observation device wherein the control device calculates a correction amount from image data acquired by the image acquisition device and controls the first correction device and the second correction device based on the calculated correction amount.

Images