JPH0795145B2 - Microscope focusing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a focusing device for a microscope.

2. Description of the Related Art As a focusing device for a conventional microscope, for example, FIGS.
A focusing device for a stereoscopic microscope having the configuration shown in the figure is known, 1 is a base of the microscope, 2 is a column fixed to the base 1,
Reference numeral 3 is a main body of a focusing unit fixed to the column 2, and bearings 3a and 3b are pinion shafts 4 having focusing handles 4a and 4b screwed on both ends.
Is pivoted by. Reference numeral 5 denotes a mirror body that is supported by a roller guide 6 so as to be movable up and down with respect to the focusing unit body 3.
A rack 9 including an objective lens 7 and a binocular barrel 8 and attached to the mirror body 5 meshes with a pinion shaft 4 pivotally supported on the focusing unit body 3. The handle for focusing
An elastic member 10 such as a disc spring washer and a washer 11 are provided on the pinion shaft 4 between the focusing units 4a and 4b and the focusing unit body 3 as a weighting mechanism for adjusting the amount of operating force. One of the handles 4a and 4b is fixed to the pinion shaft 4. According to this configuration, when focusing is performed, when the focusing handles 4a and 4b are rotated, the pinion shaft 4 is rotated, and the rack 9 is fixed by the engagement of the pinion shaft 4 and the rack 9. 5 moves up and down along the roller guide 6, and thus the subject 12 placed on the base 1
Focusing is performed on. By the way, the mirror body 5,
The objective lens 7 and the binocular barrel 8 each have a mass, and accordingly, they try to turn the pinion shaft 4 counterclockwise in FIG. 1 via the rack 9 by gravity, but in this case, the focusing handle 4a.
And 4b are rotated in opposite directions to tighten the focusing portion main body 3 with the handle through the elastic member 10 and the washer 11, and the frictional force between the focusing portion main body 3 and the elastic member 10 and the elastic member The frictional force between 10 and the washer 11 and the frictional force between the washer 11 and the focusing handle 4a or 4b suppress the rotational moment of the pinion shaft 4 due to the weight of the mirror body 5, the objective lens 7 and the binocular barrel 8 and prevent the mirror body 5 from moving. It prevents the natural fall. Here, for example, if the rotational moment acting on the pinion shaft 4 due to its own weight of the mirror body 5 is M, a friction moment of at least M is necessary to prevent the natural fall of the mirror body 5. In order to move it downward, the focusing handles 4a and 4b may be rotated with a rotational moment of 0 or more, but in order to move the mirror body 5 upward, the focusing handles 4a and 4b should be rotated with a rotational moment of at least 2M. 4b must be turned. As described above, the above-mentioned device including the linear guide that guides the mirror body having at least the objective lens in the optical axis direction, and the power transmission mechanism for moving the mirror body in the optical axis direction along the linear guide, The heavier the weight of the mirror body 5 and the like, the larger the operation force of the focusing handle becomes, and the weight of the mirror body tends to become heavier when the stereoscopic microscope is systematized like today. It was a problem.

Aim The present invention aims to provide a focusing device for a microscope having a small amount of operating force.

In general, a mirror body having at least an objective lens, a focusing unit body having a linear guide for guiding the mirror body in the optical axis direction of the objective lens, and a focusing unit body provided between the focusing unit body and the mirror body In a focusing device of a microscope including a power transmission mechanism for moving a mirror body along the linear guide, and a weighting mechanism for adjusting an operation force amount of the power transmission mechanism, the microscope focusing device is fixed to the focusing unit main body. A rotary member pivotally attached to the fulcrum shaft and receiving a rotation moment by the load of the mirror body; and an elastic member connected to the rotation member and imparting a rotation moment in a direction opposite to the rotation moment by the load of the mirror body. And a load of the mirror body is reduced by the elastic member via the rotating member.

Furthermore, other features of the present invention will be apparent from the following description of the embodiments.

EXAMPLES The present invention will be described below based on examples shown in the drawings.
If the same components as those in the conventional example of FIG. 1 are designated by the same reference numerals and the explanation thereof is omitted, one end of 20 is pivotally attached to a link support member 21 fixedly attached to the focusing unit main body 3. The first link 22 constituting the rotating member has one end pivotally attached to the link support member 23 fixedly arranged on the mirror body 5 and the other end near the free end of the first link 20. A second link 24, which is pivotally attached to the first link 20, is an elastic member such as a tension spring stretched between the free end of the first link 20 and the focusing unit main body 3, and is a mirror body 5.
Is applied to the first link 20 via the second link 22 in the direction opposite to the rotation moment applied to the first link.

The embodiment of the present invention is configured as described above, where:
The pivot point of the link 20 to the support member 21 is O, and the link of the link 22 is
The pivot point to 20 is P, the pivot point of the link 22 to the support member 23 is Q,
Let R be the free end of the link 20, S be the attachment point of the elastic member 24 to the focusing unit body 3, and W be the total load on the mirror body side, PQ length is l ₁ , OP length is l ₂ , OR Is l ₃ , angle OQP is θ ₁ , angle POQ is θ ₂ , angle ORS
By θ and W, the horizontal and vertical components of the force acting on the link 22 are f _x and f _y , the length of RS is L, the free length of the elastic member 24 and the spring constant are Lo, k, and W, respectively. Let M _{1 be} the moment acting on, and M ₂ be the moment acting on the link 20 by the elastic member 24, From f _y = W Becomes Note that θ ₁ and θ ₂ are angles determined by the lengths of l ₁ and l ₂ and OQ. Further, regarding the elastic member 24, it is expressed as M ₂ = l ₃ × k (L−Lo) sin θ. Note that M ₂ is a moment acting in the opposite direction to the moment M ₁ acting on the link 20 by W. Fourth
The figure is a graph showing the relationship between the position of the mirror body and the moment M ₁ , that is, the formula.Therefore, by appropriately setting l ₃ , k, L, Lo, and θ in the formula, M ₂ is set within the range of movement of the mirror body. Approximately the same as M ₁ , that is, the graphs can be overlapped, so that the two moments M ₁ and M ₂ are substantially balanced, and the focusing operation, that is, not shown (see FIG. 1). As a result, the operation force of the focusing handle is small.

FIG. 5 shows a second embodiment of the present invention, in which 30 is a cam lever constituting a rotating member pivotally attached to a pivot pin 31 fixedly attached to the focusing unit body 3, and 32 is a cam lever. A cam lever pivotally mounted on a supporting member 33 fixedly arranged on the mirror body 5
Rotating members such as rollers and bearings that can come into contact with the cam contour of the cam 30, and 34 is an elastic member stretched between the free end of the cam lever 30 and the focusing unit body 3 and rotated by the load of the mirror body 5. The member 32 presses the cam contour of the cam lever 30 to give a rotational moment to the cam lever 30 in a direction opposite to the rotational moment given to the cam lever 30. According to the embodiment thus constructed, the pivot point of the cam lever 30 is O ', the rotating member 32 and the cam lever 30 are
P is the foot of the perpendicular line from O'to the tangent line at the contact point Q'with the cam portion, R'is the attachment point of the elastic member 34 to the cam lever 30, and R'is the attachment point of the elastic member to the focusing unit body 3. S ',
The total load on the mirror body side is W ′, the length of P′Q ′ is l ₁ ′, the length of O′R ′ is l ₂ ′, the angle between the vertical line and P′Q ′ is θ ₁ ′, and the angle O is ′
R ′S ′ is θ ′, the force exerted on the cam contour by the rotating member 32 is f, the length of R ′S ′ is L ′, the free length and spring constant of the elastic member 34 are Lo ′ and k ′, If the moment acting on the cam lever 30 by W ′ is M ₁ ′ and the moment acting on the cam lever 30 by the elastic member 34 is M ₂ ′, Further, regarding the elastic member 34, it is expressed as M ₂ = l ₂ ′ × k ′ (L′−Lo ′) sin θ ′. Therefore, in the formula, l ₁ ′, l ₂ ′, k ′,
By appropriately setting the positions and shapes of Lo ′ and the rotating member 32 and the cam lever 30, M ₁ ′ and M ₂ ′ can be approximately the same within the moving range of the mirror body 5, and thus, As in the embodiment of FIG. 3, the two moments M ₁ ′ and M ₂ ′ will be substantially balanced.

EFFECTS OF THE INVENTION As described above, according to the present invention, the rotating member that receives a rotation moment due to the load of the mirror body and the elastic member that gives the rotation member a rotation moment in a direction opposite to the rotation moment are provided. Since the rotational moments of both sides are always substantially balanced, there is no need for the amount of operating force to resist the load of the mirror body during focusing operation, and a small amount of operating force for always moving the lens barrel is required. It is possible to perform the focusing operation of the microscope, and it is also possible to reduce the load applied to the power transmission mechanism such as the rack and the pinion shaft for performing the focusing, and an extremely effective focusing device is provided. This is particularly effective in the case of a stereomicroscope that has been obtained and is further systematized.

In the above description, the case in which the present invention is applied to a stereoscopic microscope has been described, but it goes without saying that the present invention can be applied to microscopes having other configurations as well.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a conventional focusing device for a stereoscopic microscope, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is an embodiment of a focusing device for a microscope according to the present invention. FIG. 4 is a schematic side view showing the relationship between the moment acting on the link by the mirror and the position of the mirror in the embodiment of FIG.
The drawing is a schematic side view showing a second embodiment of the present invention. 1 ... microscope base, 2 ... pillar, 3 ... focusing unit body,
4 ... Pinion shaft, 5 ... Mirror body, 6 ... Roller guide,
7 ... Objective lens, 8 ... Binocular tube, 9 ... Rack, 10
...... Elastic member, 11 ・ ・ ・ Washer, 12 …… Subject, 20,22
...... Link, 21,23 ...... Link support member, 24,34 …… Elastic member, 30 …… Cam lever, 31 …… Pivot pin, 32 …… Rotating member, 33 …… Support member.

Claims (3)

[Claims] 1. A mirror body having at least an objective lens, a focusing unit body having a linear guide for guiding the mirror body in the optical axis direction of the objective lens, and between the focusing unit body and the mirror body. A focusing device for a microscope, comprising: a power transmission mechanism that is provided to move the mirror body along the linear guide; and a weighting mechanism that adjusts an operation force amount of the power transmission mechanism. A rotating member pivotally attached to a fulcrum shaft fixed to the main body and receiving a rotational moment by the load of the mirror body;
An elastic member coupled to the rotating member for applying a rotating moment in a direction opposite to a rotating moment due to the load of the mirror body, and reducing the load of the mirror body by the elastic member via the rotating member. A focusing device for a microscope. 2. The rotating member includes a first link having one end pivotally attached to a fulcrum shaft fixed to the focusing unit main body and the elastic member connected to the other end, and the first link of the first link. It has a second link, one end of which is pivotally attached and the other end is pivotally attached to a support member fixed to the mirror body, and the load of the mirror body is applied to the first link through the second link to provide a rotation moment to the first link. The focusing device for a microscope according to claim (1), characterized in that the focusing device for a microscope is used. 3. The rotating member is pivotally attached to a fulcrum shaft fixed to the focusing unit main body, the elastic member is connected to one end side thereof, and the other end side is rotatable with respect to a supporting member of the mirror body. A cam lever having a cam contour portion with which a rotating body pivotally attached abuts, and a load of the mirror body is exerted on the cam lever via the rotating body and the cam contour portion. Focusing device for a microscope in the range (1).