JPH09311262A - Autofocusing mechanism for microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an autofocusing mechanism for a microscope which acts while the moving center of an objective lens is always aligned with an optical axis with a simple constitution in the autofocusing mechanism of the microscope provided with a lever type displacement and enlargement mechanism. SOLUTION: This autofocusing mechanism is provided with a groove 6 which is easily elastically deformed between the objective lens of a lens holder 2 holding the objective lenses 4 and 4' of the lever type displacement and enlargement mechanism and a fulcrum, and a groove 7 on an end on the lens 4 side of the holder 2. Such an elastic body 8 as a leaf spring whose one end is joined with the groove 7 and the other end is fixed is arranged, so that this mechanism acts in a direction for preventing the displacement of the lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a microscope autofocus mechanism.

[0002]

2. Description of the Related Art A lever type displacement magnifying mechanism constituting a conventional autofocus mechanism is shown in FIGS. FIG.
(A) and (B) are the top views and side views of a lever type displacement magnifying mechanism part, respectively. FIG. 4 is a diagram showing the operation state of FIG.

In FIG. 3, the piezoelectric element 15, the objective lens 14, the lens holder 12, and the support block 11 are the rotary shaft 1.
It is rotatably fixed to the support blocks 11 and 11 ′ by 3. The objective lenses 14 and 14 'are attached to the long axis end of the lens holder 12, and the lens holder 1
The piezoelectric element 15 is connected and arranged at the short axis end of 2. Further, the compression spring 16 is connected to the piezoelectric element 15 via the lens holder 12.
Is being preloaded.

When the piezoelectric element 15 expands or contracts to adjust the focus of the object to be measured, the lens holder rotates by the angle θ about the rotating shaft 13 as a fulcrum by the lever principle, as shown in FIG. FIG. 4 shows the case where the piezoelectric element is expanded, and when it is contracted, it rotates in the opposite direction. Therefore, the objective lenses 14 and 14 'move upward, the distance to the object to be measured changes, and the objective lenses 14 and 14' are adjusted to the optimum positions. However, there is a drawback that the central axis of the objective lens deviates from the optical axis by an angle θ due to the rotational movement with the rotating shaft 13 as a fulcrum.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a microscope having a simple structure, a small size, and a low cost, and the optical axis of the objective lens and the optical axis always match. It is to realize an autofocus mechanism.

[0006]

In order to achieve the above-mentioned object, the present invention eliminates the occurrence of a tilt angle which is a drawback of the displacement magnifying mechanism adopting the lever principle, so that the lens holder is easily elastically deformed. Such a groove is provided, and an elastic body such as a leaf spring and a joining groove are arranged at the end of the lens holder on the objective lens side.

As a result, even if the lens holder is tilted by the angle θ, the elastic body is rotationally deformed in the direction opposite to the angle θ with the elastic deformation groove of the lens holder as a fulcrum, so that the objective lens moves up and down parallel to the optical axis. To do. Therefore, a visual field shift does not occur, and a highly accurate autofocus mechanism for a microscope can be realized.

1A and 1B are a plan view and a side view, respectively, of a displacement magnifying mechanism of the present invention. 2 is a lens holder, 3 is a rotation axis, 4'is an objective lens, 6 is a groove for elastic deformation, 7 is a joining groove, and is an elastic body.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiment of the present invention shown in FIG. 2 will be described below. Rotating shaft 3, piezoelectric element 5, objective lens 4, lens holder 2, support block 1, lens holder 2
Is rotatably fixed to the support blocks 1 and 1'by a rotary shaft 3.

The objective lenses 4 and 4'are attached to the long axis end of the lens holder 2, and the piezoelectric element 5 is connected and arranged to the short axis end of the lens holder 2. An elastic deformation groove 6 is provided between a part of the lens holder 2, that is, the rotary shaft 3 and the objective lens, and an elastic body 8 such as a leaf spring and a joining groove 7 are further provided at the end on the objective lens side. Reference numeral 10 is a fixed portion of the elastic body 8. Further, the compression spring 9 applies a preload to the piezoelectric element 5 via the lens holder 2.

This operation will be described below. When a voltage is applied to the piezoelectric element 5 from the outside (not shown), the piezoelectric element 5 expands and contracts in the longitudinal direction according to the voltage. Therefore, the lens holder 2 connected to the piezoelectric element 5 rotates by the angle θ about the rotation shaft 3. However, the lens holder 2
Since the groove 6 for elastic deformation, the joining groove 7 and the elastic body 8 are provided in the lens holder 2, a part of the lens holder 2 rotates in the direction opposite to the angle θ with the groove 6 for elastic deformation as a fulcrum. 'Is up and down horizontally. As a result, since the central axes of the objective lenses 4 and 4'are displaced in parallel to the optical axis, no visual field shift occurs and a highly accurate autofocus mechanism for a microscope can be realized.

It is important to relate the shape of the elastic deformation groove 6 and the spring constant of the elastic body 8 so that the objective lenses 4 and 4'can be held horizontally even if the rotation angle θ of the lens holder 2 changes. is there. A piezoelectric element may be used instead of the elastic body 8 to keep the objective lenses 4 and 4 ′ horizontal. In the present embodiment, the illustration and description of the moving mechanism for switching the objective lens is omitted.

[0013]

According to the present invention, it is possible to realize a small-sized, inexpensive, highly accurate autofocus mechanism for a microscope with a simple structure.

[Brief description of drawings]

FIG. 1 is a plan view (A) and a side view (B) showing a configuration of the present invention.

FIG. 2 is a side view of an embodiment of the present invention.

FIG. 3 is a plan view (A) and a side view (B) showing a conventional configuration.

FIG. 4 is a side view of a conventional example.

[Explanation of symbols]

 1, 1 ', 11, 11' Support block 2, 12 Lens holder 3, 13 Rotation axis 4, 4 ', 14, 14' Objective lens 5, 15 Piezoelectric element 6 Elastic deformation groove 7 Bonding groove 8 Elastic body 9, 16 Compression spring 10 Fixed part

Claims (1)

[Claims] 1. An autofocus mechanism for a microscope including a lever type displacement magnifying mechanism for holding an objective lens, wherein an objective lens is provided at one end far from a fulcrum of the lever type displacement magnifying mechanism and an electromechanical conversion element is provided at one end near the fulcrum. The objective lens holding member is moved parallel to the optical axis by providing an elastic deformation groove on the fulcrum side of the objective lens holding member and connecting an elastic body to the opposite side of the fulcrum of the objective lens holding member. An autofocus mechanism for a microscope, which is characterized in that