JP3389310B2 - Intermediate lens barrel for microscope drawing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for drawing in a microscope capable of tracing the shape of a magnified image by observing a magnified image of a specimen and simultaneously superimposing images of a drawing paper on a desk in the same visual field. The present invention relates to an intermediate lens barrel, and is particularly used for an infinity-corrected microscope.

[0002]

2. Description of the Related Art If an image of a specimen and an image of a drawing sheet are made to overlap each other in the visual field, it is possible to capture the image in the visual field by drawing a picture on the drawing sheet (of course, a pencil or the like at that time). The tip of the writing instrument is visible in the field of view). Therefore, by tracing the outline of the sample in the visual field with a pencil or the like, a picture similar to the sample can be drawn on the paper. A device used to draw a picture similar to a specimen in this way is called a drawing device. The basic principle and configuration of the drawing intermediate lens barrel used in this drawing apparatus are already known, and are manufactured and sold for general microscopes. The basic principle and configuration are that two folding mirrors are provided, an image of drawing paper is once formed as an intermediate image, and then the image is formed on the focal plane of the eyepiece lens. In this way, the observation image of the specimen and the image of the drawing paper can be superposed and simultaneously observed within the field of view of the eyepiece. These functions are configured in the form of an intermediate lens barrel, and are used by being arranged between the objective lens and the observation lens barrel.

Generally, in an infinity-corrected microscope, as shown in FIG. 4, the light from the sample 1 is converted into a parallel light flux by the objective lens 2, and this light flux is condensed by the imaging lens 3 to form the focal plane of the eyepiece lens. An image of the specimen 1 is formed on 4. Then, this image is observed through the eyepiece 5. Therefore, when the intermediate lens barrel is used, the distance 1 between the objective lens 2 and the imaging lens 3 is extended and the intermediate lens barrel is inserted between them. That is, as in the apparatus shown in FIG. 5 described later, the intermediate lens barrel is placed on the body of the microscope, and the observation lens barrel is placed on the intermediate lens barrel for use.

FIG. 5 shows a state in which a general drawing intermediate lens barrel is set in a microscope. In the figure, 11 is a microscope body, 12 is a stage for mounting a sample, 13 is an objective lens, 14 is a revolver for mounting the objective lens, 15 is an eyepiece tube, 16 is between the microscope body 11 and the eyepiece tube 15. Is an intermediate lens barrel for drawing provided in the. The eyepiece tube 15
Has an imaging lens (not shown), a prism for splitting light from an objective lens into left and right eyepieces, and an eyepiece. When the intermediate lens barrel 16 is not used, the eyepiece tube 15 is directly attached to the body 11 for use. Further, a half mirror 18 is obliquely provided inside the drawing intermediate lens barrel 16 so as to divide the optical path on the microscope optical path. Side tube 2 extending from the intermediate lens barrel 16 for drawing
A mirror box having a reflecting mirror 17 is provided at the front end of 0, and a lens group (not shown) is provided between the reflecting mirror 17 and the half mirror 18 inside the side cylinder 20. The reflection mirror 17, the lens group, and the half mirror 18 can reduce and project the image of the drawing paper 19 so as to overlap with the object image formed by the imaging lens. The hatched portion in FIG. 5A is a part of the body 11. Further, FIG. 2B is a side view of the device shown in FIG. 1A viewed from the left side of the drawing.

Further, in general, when the focal length of the lens system in the intermediate lens barrel is fixed, the projection magnification of the drawing paper on the focal plane of the eyepiece lens (hereinafter referred to as the drawing-side projection magnification) is constant. It is immutable. However, if the focal length is variable, the drawing-side projection magnification can be changed.

[0006]

However, as described above, when the intermediate lens barrel for drawing is set between the objective lens and the observation lens barrel, if the objective lens is a lens for finite distance correction, You always need a lens to extend the image. Since this image extension lens has a magnification (intermediate magnification), depending on whether or not the drawing intermediate lens barrel is attached,
The magnification of the observation image on the object side changes. In this case, the magnification series changes with the switching of the objective lens, which is inconvenient for practical use. Further, in the conventional microscope, the drawing magnification of the drawing intermediate lens barrel cannot be maintained unchanged with respect to the additional insertion of the intermediate lens barrel, or the intermediate lens barrel itself cannot be added. Further, the drawing intermediate lens barrel could not be additionally mounted with the epi-illumination tube set.

The present invention has been made in view of the above-mentioned problems of the prior art. Even if the intermediate lens barrel is further stacked on the infinity-corrected microscope, the intermediate magnification is always 1.
Moreover, it is an object of the present invention to provide an intermediate lens barrel for drawing of a microscope that does not affect the magnification of the observation image on the objective side and the drawing magnification.

[0008]

In order to achieve the above object, an intermediate lens barrel for drawing of a microscope according to the present invention is an intermediate lens barrel for drawing which can be mounted between an objective lens of a microscope for infinity correction and an observation lens barrel. A first reflecting member that is a lens barrel and bends an optical axis from a drawing paper in a direction approaching the optical axis of an objective lens; and a first reflecting member that forms an image of the drawing paper as an intermediate image. A lens group, a second lens group having a function of projecting the intermediate image at infinity, and a function of bending the optical axis bent by the first reflecting member so as to overlap the optical axis of the objective lens. And a second reflecting member, and in the order of the first lens group and the first reflecting member viewed from the drawing side while keeping the optical path length from the first lens group to the drawing sheet substantially constant. Be configured to be interchangeable It is characterized. The intermediate lens barrel of the present invention is also characterized in that the focal length of the second lens group is fixed or variable, and the focal length of the first lens group is fixed. Is characterized in that the image forming magnification m ₁ of the intermediate image satisfies the following conditional expression. 0.02 ≦ | m ₁ | ≦ 0.06

[0009]

The operation of the present invention will be described below with reference to FIG.
FIG. 1 is a diagram illustrating the principle of the present invention. In the figure, 21 is a drawing sheet, 22 is an objective lens, 23 is an intermediate lens barrel (such as an epi-illumination tube), L ₁ is a first lens group, L ₂ is a second lens group, L ₃
Is an imaging lens of a microscope, M ₁ is a first mirror (first reflecting member), and M ₂ is a second mirror (second reflecting member: half mirror). FIG. 1A shows the arrangement of the optical system when the drawing intermediate lens barrel 16 is attached to the infinity-corrected microscope. In this case, the first lens unit L ₁ includes the first mirror M ₁
When positioned between the second lens group L _2. The light from the object is converted into a parallel light flux by the objective lens 22, and the light flux is converged by the imaging lens L ₃ to form an object image on the focal plane of the eyepiece lens. On the other hand, the light from the drawing paper 21 is reflected by the first mirror M ₁ and then converged by the first lens group L ₁ before the second lens group L ₂ (between L ₁ and L ₂ ).
First, an intermediate image of the drawing paper 21 is formed. Then, the second lens group L ₂ further forms a parallel light beam, and the second mirror M
Is reflected by _2, the image drawing sheet 21 is formed on the image at the same position of the sample by an imaging lens L _3. Therefore, a composite image in which the image of the specimen and the image of the drawing paper 21 are superposed can be observed through an eyepiece lens (not shown).

In the infinity-corrected microscope optical system, the magnification of the objective lens 22 does not change even if the distance between the objective lens 22 and the imaging lens L ₃ is changed. Therefore, when an intermediate lens barrel is added by taking advantage of this advantage, the intermediate lens barrel to be added is inserted between the drawing intermediate lens barrel and the objective lens 22, as shown in FIG. In such a state, the distance between the first lens unit L ₁ and the drawing paper 21 becomes longer by the length of the intermediate lens barrel to be added. Therefore, even if focusing is performed by the second lens unit L ₂ , the drawing side. The projection magnification of will change. Therefore, the first lens unit L ₁ and the first mirror M
By replacing the order of ₁ to configure the distance between the first lens group L ₁ and the drawing paper 21 and the distance between the first lens group L ₁ and the second lens group L ₂ , respectively,
Therefore, it is possible to add an intermediate lens barrel without changing the projection magnification on the drawing side. This state is shown in FIG.

FIG. 1B shows a state in which the order of the first mirror M ₁ and the first lens group L ₁ is changed in order to use the drawing intermediate lens barrel and another intermediate lens barrel 23 in an overlapping manner. ing. Such replacement may be performed, for example, according to the procedure shown in FIG. 2A shows a state corresponding to FIG.
1B shows states corresponding to FIG. 1B, respectively.
As shown in FIG. 2A, an auxiliary cylinder 50 for expanding and contracting the length of the side cylinder 20 is provided at the tip of the first mount portion 50a.
The lens ring 51 including the first lens unit L ₁ is attached to the tip of the auxiliary cylinder 50 by the mount portion 50b. The mirror box 52 provided with the first mirror M ₁ so as to cover the lens ring 51 is the auxiliary cylinder 5.
It is attached to the second mount portion 50c provided at 0.
The mount portion 50a and the mount portion 50b have the same structure. Also, when additionally inserting the intermediate lens barrel, as shown in FIG.
As shown in, the auxiliary cylinder 50 and the lens ring 51 are removed from the mount portion 50a. Further, the auxiliary cylinder 50 and the lens ring 5
Separate from 1. Then, the mirror box 52 is attached to the side cylinder 2
It is attached to the mount portion 20a having the same structure as the mount portion 50c provided in No. 0. On the other hand, the lens ring 51 is attached to the lower opening 52a (the entrance of the light from the drawing paper) of the mirror box 52 via the adapter 53.

By the above procedure, the first mirror M
_{The order of 1} and the first lens unit L ₁ can be easily exchanged. Further, by setting the sizes of the auxiliary cylinder 50, the mirror box 52, the adapter 53, and the lens ring 51 to the optimum sizes, respectively, the distance between the first lens group and the drawing paper and the first lens group and the second lens are set. The distance from the group can be kept constant, and thus the image formation state of the light flux can be kept good.

The intermediate lens barrel for drawing is, as is well known, a device capable of observing an image of a drawing sheet in the visual field of the eyepiece by superimposing it on the image of the objective lens. Therefore, during the drawing operation, it is preferable that the size of the drawing sheet that can be seen in the field of view is a size that is easy to see. Of the various types of paper currently in use, A4 is the most widely used.
It is a paper of size (210 mm × 297 mm). From the viewpoint of ease of drawing, it is considered most preferable to set the magnification so that a paper of this size is inscribed in the visual field as a drawing paper.

On the other hand, the optimum size of the image formed by the objective lens on the side of drawing is about 20 to 22 fields of view. This is because it is necessary to pay attention to the observation image during drawing work, so if the number of fields of view is too large, a wide range of fields of view will be observed, which causes eye fatigue and makes it difficult to continue the work. is there. The diagonal size of the four sizes is about 364 mm according to the Pythagorean theorem. When this size overlaps the image of the specimen and inscribes in the visual field, the magnification is 20 / 346≈0.055≈1 / 18.2 when the visual field number is 20, and 11 / when the visual field number is 22. 364≈0.06≈1 /
It can be calculated as 16.5. That is, it is considered appropriate that the imaging magnification of the drawing paper is approximately 1/18 to 1/16. Even if the zoom optical system is adopted to make the magnification on the drawing side variable, the lower limit of the magnification is about 1/18.
It can be said that 1 to 16 times is appropriate. If the magnification is smaller than this, the drawing side becomes too small and the pen tip or the like becomes difficult to see, which is not suitable.

The focal length of the imaging lens of the microscope is f ₃ , the focal length of the second lens group is f ₂ , the magnification of the intermediate image on the drawing side by the first lens group is m ₁ , and the eyepiece focus of the drawing paper on the drawing side. When the image forming magnification on the surface is m, m = (f ₃ / f ₂ ) × | m ₁ | In the above formula (1), the focal length f ₂ of the second lens group (when the variable f ₂ is variable, the maximum value is f ₂ ) is f ₃ ≧ f ₂ , that is, f ₃ / f ₂ ≧ 1 ... (2) is preferable. This is a condition for making the overall length of the lens system compact. Also, as described above, m
Since ≧ 0.055 to 0.066, (f ₃ / f ₂ ) × | m ₁ | ≧ 0.06 ... (3) according to the equation (1). Further, from equations (2) and (3), | m ₁ | ≦ 0.06 ... (4) Here, the absolute value conforms to m ₁ is attached is because actually m ₁ is a negative real number.

Further, it is preferable that m ₁ is │m ₁ │ ≧ 0.02 ... (5). If the value of | m ₁ | falls below the lower limit of the equation (5), the distance between the first lens group and the drawing paper must be set larger than necessary, or the focal length of the first lens group becomes It must be made small enough to cause deterioration of surface curvature. From the above, equations (4) and (5)
Together conditions, | m ₁ | optimal range of possible values of, 0.02 ≦ | a ≦ 0.06 | m _1.

[0017]

FIG. 3 is a diagram showing an embodiment according to the present invention, in which (a) is a state in which an intermediate lens barrel is not additionally inserted,
(B) shows a state in which an intermediate lens barrel is additionally inserted between the drawing intermediate lens barrel and the objective lens. In the figure, the same members as those shown in FIG. 1 are designated by the same reference numerals. Further, in the present embodiment, the principle configuration shown in FIG. 1 is further embodied, and the second lens unit L
₂ shows a case where the focal length is fixed, and further, the first lens unit L ₁ is configured so as to be attachable / detachable so as not to be reversed (both the first lens unit in FIGS. 3A and 3B). The positive meniscus lens of L ₁ faces the drawing paper).

The numerical data of the lens in this embodiment will be shown below. r ₁ = ∞ (drawing paper surface) d ₁ = 341 r ₂ = -89.4 d ₂ = 4.5 n ₂ = 1.713 ν ₂ = 53.84 r ₃ = -9.534 d ₃ = 0.2 r ₄ = 27.609 d ₄ = 1.4 n ₄ = 1.78472 ν ₄ = 25.71 r ₅ = 9.034 d ₅ = 0.88 r ₆ = 12.42 d ₆ = 8.9 n ₆ = 1.713 ν ₆ = 53.84

R ₇ = -21.354 d ₇ = 109.9 r ₈ = 30.655 d ₈ = 4.5 n ₈ = 1.51633 ν ₈ = 64.15 r ₉ = -54.355 d ₉ = 22.56 r ₁₀ = -8.915 d ₁₀ = 2 n ₁₀ = 1.68893 v ₁₀ = 31.08 r ₁₁ = 135.138 d ₁₁ = 5.1 r ₁₂ = -27.78 d ₁₂ = 4 n ₁₂ = 1.734 v ₁₂ = 54.19 r ₁₃ = -12.558

However, in the above numerical data, r ₁ , r
₂ , ..., Radius of curvature of each lens surface, d ₁ , d ₂ ,
... is the thickness of each lens or the lens interval, n ₁ , n ₂ ,
··· is the refractive index of each lens, and ν ₁ , ν ₂ , ··· is the Abbe number of each lens.

As described above, in the infinity-corrected microscope,
The focal length of the image forming lens is f ₃ , the focal length of the second lens unit is f ₂ , the image forming magnification of the intermediate image by the first lens unit is m ₁ , and the drawing side drawing sheet is focused on the focal plane of the eyepiece lens. When the imaging magnification is m, the relationship of m = (f ₃ / f ₂ ) × | m ₁ | holds. In the case of this embodiment, | m ₁ |
= 0.034, f ₂ = 98.21, and although not shown here, the focal length f ₃ of the imaging lens of the microscope is f ₃ =
180, m = (180 / 98.21) × 0.034 = 0.062
4 = 1/16. Further, in the apparatus of the present embodiment, M ₁ is a mirror and M ₂ is a half mirror with prism bonding, but M ₂ may be a simple half mirror. Furthermore, if the second lens unit L ₂ is configured as a zoom lens, m> 1/16 can be achieved, and the flexibility of drawing magnification can be increased. It goes without saying that the drawing intermediate lens barrel of the present invention also has a function as a macro device.

[0022]

As described above, by using the intermediate lens barrel for drawing of the microscope according to the present invention in the microscope optical system for infinity correction, (1) the intermediate magnification remains constant at 1 × (2). ) Even if an additional intermediate lens barrel is additionally inserted, the magnification on the drawing side does not change. (3) The drawing paper can be placed within the field of view in a size that makes it easy to draw (4) The entire optical system can be made compact, etc. It has various practical advantages.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention, in which (a) is a configuration diagram of an optical system when only a drawing intermediate lens barrel is attached to a microscope with infinity correction, and (b) is a drawing intermediate lens barrel. It is a block diagram of an optical system in the case of using another intermediate lens barrel in an overlapping manner.

FIG. 2 is a diagram for explaining a change in the order of the first lens group and the first reflecting member in the present invention, and FIG. 2A is a diagram in the case where only a drawing intermediate lens barrel is attached to a microscope for infinity correction. FIG. 1B is an explanatory diagram in the case of using the drawing intermediate lens barrel and another intermediate lens barrel in an overlapping manner.

FIG. 3 is a diagram showing an embodiment according to the present invention,
FIG. 7A is a diagram showing a state in which an intermediate lens barrel is not additionally inserted, and FIG. 9B is a diagram showing a state in which an intermediate lens barrel is additionally inserted between the drawing intermediate lens barrel and the objective lens.

FIG. 4 is a principle configuration diagram of an infinity microscope.

5A and 5B are explanatory views of a state in which a conventional intermediate lens barrel for drawing is set in a microscope, FIG. 5A is a front view, and FIG. 5B is a side view of FIG.

[Explanation of reference numerals] 1 sample 2 objective lens 3 imaging lens 4 eyepiece focal plane 5 eyepiece 11 microscope body 12 stage 13 objective lens 14 revolver 15 eyepiece tube 16 drawing intermediate lens barrel 17 reflecting mirror 18 half mirror 19 drawing Paper 20 Side tube 21 Drawing paper 22 Objective lens 23 Intermediate lens barrel L ₁ First lens group L ₂ Second lens group L ₃ Imaging lens M ₁ First mirror (first reflecting member) M ₂ Second mirror (second (Reflecting member)

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B 21/18

Claims (4)

(57) [Claims] 1. An intermediate lens barrel for drawing, which can be mounted between an objective lens of a microscope for infinity correction and an observation lens barrel, wherein an optical axis from a drawing paper is folded in a direction approaching the optical axis of the objective lens. A first reflecting member that acts to bend, a first lens group that acts to form an image of a drawing sheet as an intermediate image, a second lens group that acts to project the intermediate image to infinity, and An optical path from the first lens group to the drawing sheet, and a second reflecting member that acts to bend the optical axis bent by the first reflecting member so as to overlap with the optical axis of the objective lens. An intermediate lens barrel for drawing of a microscope, characterized in that the order of the first lens group and the first reflecting member viewed from the drawing side can be exchanged while the length is kept substantially constant. . 2. The intermediate lens barrel for drawing of the microscope according to claim 1, wherein the focal length of the second lens group is fixed or variable. 3. The intermediate lens barrel for drawing of the microscope according to claim 1, wherein the focal length of the first lens group is fixed. 4. The intermediate lens barrel for drawing of a microscope according to claim 1, wherein an image forming magnification m ₁ of the intermediate image by the first lens group satisfies the following conditional expression. 0.02 ≦ | m ₁ | ≦ 0.06