JPH089696Y2 - Zoom lens for stereo microscope Fixing structure of guide axis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a structure for fixing a zoom lens guide shaft for a stereoscopic microscope.

[Conventional technology]

In recent years, zoom lenses are required to have high magnification and high zoom ratio. Along with this, a method using a guide shaft has become the mainstream for the support structure of the zoom lens. The reason is as follows.

The moving lens group in the zoom lens system having a high magnification and a high zoom ratio tends to be a lens having a large power inevitably because it gives a large change to the lens system. The decentering, tilt, position, etc. of a lens having a large power have a great influence on the misalignment, parfocal misalignment, etc. of the zoom lens system. For example, the decentering of the lens appears 15 times as much as the decentering of the image. So
It is necessary to move it with as little shaking and displacement as possible. For this reason, in particular, in a stereomicroscope having a very high magnification as compared with an optical device such as a camera, a guide shaft system, which allows a longer fitting length between a lens frame and a guide shaft, has been popular in recent years.

As a conventional fixing structure of a zoom lens guide shaft for a stereoscopic microscope, for example, as shown in FIG. 6, both ends 2a and 2b of the guide shaft 2 are fitted into the upper and lower holes 1a and 1b of the main body frame 1, respectively. , The both ends 2a, 2b being adhered to the main body frame 1 using adhesives 3, 3, respectively, and the both ends of the guide shaft 2 in the upper and lower holes 1a, 1b of the main body frame 1 as shown in FIG. The parts 2a and 2b are fitted to each other, and the both ends 2a and 2b are fastened and fixed using immobilis 4 and 4 orthogonal to the axial direction, respectively, as shown in FIG. 1a, 1b on both ends 2a of the guide shaft 2,
2b are fitted into each other, and ring-shaped grooves 2a ', 2a' having a V-shaped cross section are provided at both ends 2a, 2b, respectively, and a conical tip 5
The tip 5a of the immobis 5,5 having a, 5a orthogonal to the axial direction,
5a fitted into the ring-shaped grooves 2a 'and 2b' respectively and fastened and fixed; upper and lower holes 1a, 1 of the body frame 1 as shown in FIG.
Both ends 2a and 2b of the guide shaft 2 are fitted to b, respectively,
One in which a stopper washer 6 is fitted to one end 2a, and an axial screw 7 is screwed into and fixed to the other end 2b. As shown in FIG. Holes 1a, 1b
Both ends 2a and 2b of the guide shaft 2 are fitted to the
There has been one in which a stopper washer 6 is fitted to one end 2a, and an axial screw 7 is screwed and fastened to the other end 2b via a spring washer 8.

[Problems to be Solved by the Invention]

However, the one shown in FIG. 6 has a problem that the maintenance process is difficult because the bonding process is a top-down manufacturing process and cannot be disassembled. Further, in the structure shown in FIG. 6 and FIG. 7, both ends of the guide shaft 2 are fixed to the body frame 1 facing each other by the adhesive 3 or the immobilizer 4, so that the pulling force or the urging force by the expansion and contraction of heat is generated. There is a problem that the guide shaft 2 is deformed by the force.
Further, as shown in FIG. 8, the force of pulling the main body frames 1, 1 inward is generated by the cooperative action of the slopes of the blade tips 5a, 5a of the set screws 5, 5 and the slopes of the ring-shaped grooves 2a ', 2b'. As a result, the body frame 1 and the guide shaft 2 are deformed, and when the guide shaft extends due to heat, the surface of the ring-shaped groove 2a is separated from the immobilizer 4 and the guide shaft 2 is loosened. There was a problem. Also, the screw shown in FIG.
There is a problem in that the force of pulling the main body frames 1, 1 inward is generated by tightening, and thereby the main body frame 1 and the guide shaft 2 are deformed. In the case shown in FIGS. 8 and 9, it is necessary to set the fastening torque to a predetermined value so that the deformation can be accommodated within a certain degree. In addition, as shown in FIG. 10, since there is a spring washer 8, it is not necessary to set the fastening torque, but the outer peripheral surfaces of both end portions 2a, 2b of the guide shaft 2 and the holes 1a, 1b of the main body frame 1 There is a risk of eccentricity corresponding to the respective gaps with the peripheral surface, and this is also true for the one shown in FIG. 9. As is the case with all of the above conventional examples, the main body frame 1, the guide shaft 2, the immobil screws 4,5, the washers 6, and the screws 7 are composed of different materials due to the necessity of weight, wear resistance, dimensional accuracy, etc. In that case, when both ends of the guide shaft 2 are fixed to the body frames 1 and 1, if there is a difference in the linear expansion coefficient of each material, the change in temperature causes the long guide shaft 2 to move. There is a problem that the guide shaft 2 is deformed by applying a large tensile force or a tensile force to the guide shaft 2 because the amount of elongation or the amount of contraction largely changes as compared with other members.

Although the eccentricity of the guide shaft 2 due to the deformation of the body frame 1 and the guide shaft 2 is very small, it is very small in a zoom lens having a high magnification and a high zoom ratio like a stereoscopic microscope. However, there is a problem that the amount of decentering greatly affects the misalignment and parfocal misalignment of the zoom lens system, and the amount of eccentricity undesirably increases at high zooming.

The present invention has been made in view of the above problems, and an object thereof is to provide a fixing structure for a zoom lens guide shaft that does not cause eccentricity during zooming, is easy to manufacture, and is easy to maintain.

[Means and Actions for Solving the Problems]

The stereoscopic microscope zoom lens guide shaft fixing structure according to the present invention comprises a plurality of guide shafts arranged along the left and right optical axes, and left and right lens frames slidably provided on the guide shafts. A stereomicroscope equipped with a cylindrical cam arranged between the symmetrical axes of the guide shafts, and a follower that is connected to the left and right lens frames and moves in the optical axis direction along the cam portion as the cylindrical cams rotate. In the zoom lens drive mechanism, mounting members for holding the left and right guide shafts are arranged to face each other, and the ends of the guide shafts are slidably fitted to at least one of the mounting members. To form a hole, and a retaining flange-like portion is fixed to each of the guide shafts such that a slight gap exists between the hole and the edge of the hole, and a rubber is provided between the hole and the guide shaft. The O-ring made of elastically deformed The O-ring made of rubber prevents the stress deformation of the main body frame and the guide shaft due to the tensile force or the tensile force from being generated by holding the guide shaft so that it can be expanded and contracted in the axial direction. It is designed to fill the gap between the inner peripheral surface of the hole of the frame and to hold the guide shaft at the center position of the hole, and to disassemble and assemble without using a bonding step. is there.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment.

FIGS. 1 (A) and 1 (B) are a longitudinal sectional view and a schematic view of a left optical system of a mirror body portion of a stereoscopic microscope having the first embodiment, respectively, and FIG. 2 is FIG. 1 (A) II-. Sectional view along line II, 3rd
The drawing is a vertical sectional view of the first embodiment.

Reference numeral 11 is a main body frame of the stereomicroscope, 12 is two pairs of guide shafts mounted on the main body frame 11 in the vertical direction, and each pair has a downward extension line of their central axes from 10 ° to 14 ° on a sample surface not shown. It is designed to intersect at an angle of °. And each guide shaft 12
As shown in FIG. 3, the fixing structure of (1) is such that both ends 12a, 12b of the guide shaft 12 are slidably fitted in the upper and lower holes 11a, 11b of the main body frame 11, and one end 12a is The E-ring 13 is fitted in the provided ring-shaped groove 12a ', and the other end 12b is formed.
A screw 14 in the axial direction is screwed and fastened to the end, and a rubber O-ring 15 is fitted into the ring-shaped groove 12a ″ provided at one end 12a, and the O-ring 15 is attached to the outer peripheral surface of the end 12a. And the inner peripheral surface of the hole 11a are interposed in a state of being pressed and deformed in the radial direction, and the upper edge 11a 'of the hole 11a of the main body frame 11 and the hole 11a.
The dimension of each member is 5/100 to 20/100 mm so that the distance between the lower surface of the E ring 13 and the upper surface of the head of the screw 14 is longer than the distance between the lower edge 11b ′ of b. A small axial gap between the lower surface of the E-ring 13 and the upper edge 11a 'of the hole 11a or between the upper surface of the head of the screw 14 and the lower edge 11b' of the hole 11b. Is supposed to exist.

One end of 16 is slidably fitted to the guide shaft 12 on the upper side in FIG. 2, and the other end is slidably abutted on the guide shaft 12 on the lower side in FIG. The pair of first group lens frames 18, which are urged inward by (FIG. 1) and maintained in the contact state, have one end slidably fitted to the lower guide shaft 12 in FIG. The other end is the guide shaft on the upper side in Fig. 2.
The pair of second lens groups are slidably brought into contact with 12 and are urged inward by a spring (not shown) to maintain the contact state. Numeral 19 is vertically pivoted to the main body frame 11 between the guide shafts 12, 12 on the upper side of FIG. 2 and has cam grooves 19a and 19b at the lower and upper positions of the peripheral surface and an upper protruding end portion. A cylindrical cam to which a handle (not shown) is fixed, 20 is the lower guide shaft 12, 12 in FIG.
Another pair of guide shafts vertically penetrated and fixed to the main body frame 11 between them, and 21 are fitted to the cylindrical cam 19 so as to be slidable in the vertical direction, and a cam pin (not shown) fixed to the guide shaft is provided in the cam groove 19a.
For the first group in which a pair of fork portions 21a, 21a extending in the left-right direction of FIG. 2 are engaged with pins 16a, 16a fixed to the respective first-group lens frames 16, 16 respectively. The follower 22, 22 is fitted to the other guide shafts 20 and 20 so as to be slidable up and down, and a cam pin (not shown) fixed thereto is slidably fitted in the cam groove 19b and extends in the left-right direction in FIG. The fork portions 22a, 22a are second group followers engaged with the pins 18a, 18a fixed to the second group lens frames 18, 18, respectively.

L ₁ and L ₁ are a pair of first group lenses supported by both first group lens frames 16 and 16, and L ₂ and L ₂ are a pair of second group supported by both second group lens frames 18 and 18. Lenses L ₃ and L ₃ are a pair of third group lenses fixed to the main body frame 1 (see FIG. 1 (B)), and these constitute a pair of zoom type objective lenses. The optical axes intersect at the sample plane at an angle of 10 ° to 14 °.

Since the body of this stereomicroscope is constructed as described above, when the handle (not shown) is rotated, the cylindrical cam 19
Rotates to move the first group follower 16 and the second group follower 18 up and down, whereby the first group lens L ₁ and the second group lens L ₂
Are moved at regular intervals according to a certain rule, and it is apparent that zooming is performed.

In the present embodiment, as described above, there is a slight amount of space between the lower surface of the E-ring 13 and the upper edge 11a 'of the hole 11a or between the upper surface of the head of the screw 14 and the lower edge 11b' of the hole 11b. Since there is an axial gap, that is, the guide shaft 12 is fixed in the axial direction with a slight margin, stress deformation of the main body frame 11 and the guide shaft 12 due to a tensile force or a tensile force does not occur. Further, since the O-ring 15 is interposed between the outer peripheral surface of the end portion 12a and the inner peripheral surface of the hole 11a of the main body frame 11 while being pressed and deformed in the radial direction, the O-ring 15 is inserted into the guide shaft 12 The gap between the outer peripheral surface of the hole 11a and the inner peripheral surface of the hole 11a and acts to hold the guide shaft 12 in the central position of the hole 11a, thereby eliminating the risk of eccentricity of the gap. At the same time, the guide shaft 12
Even if the position is shifted, the guide shaft 12 is returned to the center position by the action of the O-ring 15 after the end of the vibration. Also, the guide shaft
Since 12 is slidably held in the hole 11a through the rubber O-ring 15, the axial extension or contraction amount of the guide shaft 12 due to temperature change can be absorbed well, and the main body 11 and the guide shaft 12 can be absorbed. No tensile force or tensile force is applied to 12 and no deformation occurs. Therefore, for the above reasons, decentering does not occur during zooming, and as a result, a lens having a large power can be employed, and a compact zoom lens system with high magnification and high zoom ratio can be realized. The zoom lens system is
It often has a strong power at either high or low magnification, so that it is often sufficient in practice to employ the O-ring 15 at one end of the guide shaft 12 as in the present embodiment. Of course, it may be adopted at both ends of the guide shaft 12, in which case the effect is greater, but in some cases it may be over-spec.

In addition, in this embodiment, since the bonding step is not adopted, it is easy to manufacture, and since disassembly and assembly are possible, maintenance management is also easy.

FIG. 4 shows a second embodiment, which is a guide shaft 12
Instead of providing the ring-shaped groove 12a "at the end 12a of the chamfer, the chamfer 11a" is formed at the upper edge 11a 'of the hole 11a.
The first embodiment except that the O-ring 15 is interposed in the space between the a ″ and the outer peripheral surface of the end portion 12a and the lower surface of the E-ring 13 while being pressed and deformed in the radial direction and the axial direction. Therefore, in this embodiment, the O-ring 15 also removes the play in the axial direction of the guide shaft 12, so that the main frame 11 and the guide shaft 12 can be firmly fixed. Has the advantage of not causing stress deformation.

FIG. 5 shows a third embodiment in which a washer 23 which is retained by the head of the screw 14 is fitted to the end 12b of the guide shaft 12 and the lower edge 11b 'of the hole 11b. Also chamfer
11b ″ is formed, and another O-ring 15 is interposed in the space between the chamfered portion 11b ″, the outer peripheral surface of the end 12b and the upper surface of the washer 23 while being pressed and deformed in the radial and axial directions. The second embodiment has the same structure as the second embodiment except that Therefore,
In this embodiment, the same effect as that of the second embodiment can be obtained more greatly.

[Effect of device]

As described above, according to the fixing structure of the zoom lens guide shaft according to the present invention, the guide shaft is made of rubber O in the hole of the mounting member.
The guide shaft is held slidably via a ring and is fixed to the guide shaft by a flange-shaped part for preventing the guide shaft from coming off so that a slight gap is created between the guide shaft and the edge of the hole. It has the practically important advantages that it can prevent the pulling force or the urging force to the like, does not cause eccentricity during zooming, is easy to manufacture, and is easy to maintain.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (A) and 1 (B) are respectively a longitudinal sectional view of a stereomicroscope having a first embodiment of a zoom lens guide shaft fixing structure according to the present invention and a schematic view of its left side optical system. Figures and 2 are the first
FIG. 3A is a sectional view taken along line II-II, FIG. 3 is a longitudinal sectional view of the first embodiment, and FIGS. 4 and 5 are longitudinal sectional views of the second and third embodiments, respectively. 10 to 10 are vertical sectional views of a conventional example. 11 …… Main body frame, 11a, 11b …… Hole, 11a ′ …… Upper edge, 11
b '... Lower edge, 11a ", 11b" ... Chamfer, 12, 20 ...
… Guide shafts, 12a, 12b …… Ends, 12a ′, 12a ″ …… Ring-shaped grooves, 13 …… E ring, 14 …… Screw, 15 …… O-ring,
16 ... 1st group lens frame, 16a, 18a ... pin, 17 ... spring, 18 ... 2nd group lens frame, 19 ... cylindrical cam, 19a, 19b
...... Cam groove, 21 ...... First group follower, 21a, 22a ...... Fork part, 22 ...... Second group follower, 23 ...... Washer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimi Hayasaka 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (56) Reference JP 61-116310 (JP, A) JP 62-30210 (JP, A) JP-A-60-163014 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A plurality of guide shafts respectively arranged along the left and right optical axes, left and right lens frames slidably provided on the guide shafts, and arranged between symmetrical axes of the guide shafts. A zoom lens drive mechanism for a stereoscopic microscope, comprising: a cylindrical cam; and a follower that is connected to the left and right lens frames and moves in the optical axis direction along the cam portion as the cylindrical cam rotates. Mounting members for holding the left and right guide shafts are arranged to face each other, and holes are formed in at least one of the mounting members so that the end portions of the respective guide shafts are slidably fitted,
A retaining flange-like portion is fixed to each of the guide shafts so that a slight gap exists between the hole and the edge portion, and a rubber O-ring is elastically provided between the hole and the guide shaft. Fixed structure of zoom lens guide shaft for stereoscopic microscope, characterized by being press-fitted in a deformed state.