JPH1123932A - Lens holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the inclination of a lens chamber to an optical axis from being changed without making a fitting clearance between the lens chamber and a lens barrel small by providing a member for energizing a lens holding member to a moving reference surface. SOLUTION: The lens 1 is fixed and held in the lens chamber 3 by a presser ring 2. The lens chamber 3 is held by fitting to the moving reference surface 9 formed on the inner surface of the lens barrel 4. The pedestal 4e of the lens barrel 4 is attached to an optical equipment 6 by screws 7a and 7b. A slit part 4a is formed on the side part of the lens barrel 4 in a perpendicular direction to the optical axis (p) so that it may pierce the side part. A wire spring 5 is inserted from the slit part 4a so as to come in contact with the point 3c of the fitting surface 3a of the lens chamber 3. The spring 5 comes in contact therewith by its nearly center part so as to energize the lens chamber 3 in a perpendicular direction (f) to the optical axis (p) at the point 3c. The lens chamber 3 is pressed to the surface 9 of the lens barrel 4 by the energizing force of the spring 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens holding device suitable for use in an optical system of an optical device such as a microscope.

[0002]

2. Description of the Related Art The structure of a conventional lens holding device is shown in FIG. As shown in FIG. 4, the lens 11 is fixed in the lens chamber 13 by the holding ring 12. The lens chamber 13
It is held on the inner surface side of the lens barrel 14 and is fitted to the lens barrel 14 at a fitting part 13 a on the outer surface of the lens chamber 13. A screw portion 13b is formed in the lens chamber 13 at the upper portion of the fitting portion 13a in the figure, and is screwed with a screw portion on the inner surface of the lens barrel 14, so that
Is rotated, the lens chamber 13 can be moved in the optical axis p direction of the lens 11. Thereby, the adjustment can be performed by moving the lens 11 in the optical axis p direction. The lens barrel 14 is attached to an optical device 16.

[0003]

In the prior art as described above, the lens chamber is held at right angles to the optical axis, but actually, there is no clearance between the lens chamber and the lens barrel. Therefore, the lens chamber slightly tilts (tilts) with respect to the optical axis, and the lens also tilts with respect to the optical axis. In this case, particularly when the fitting length between the lens chamber and the lens barrel is short, when the lens chamber is moved for adjustment in the optical axis direction, the inclination (inclination) of the lens chamber with respect to the optical axis changes. There has been a problem that the inclination also changes with each adjustment, and the optical characteristics change. Furthermore, if the clearance of the fitting is reduced as much as possible in order to reduce the inclination of the lens chamber, there is a problem that it takes time to process the parts and the manufacturing cost is increased.

It is an object of the present invention to provide a lens holding device in which the inclination of the lens chamber with respect to the optical axis does not change without reducing the clearance of fitting between the lens chamber and the lens barrel.

[0005]

In order to achieve the above object,
The lens holding device of the present invention has a lens holding member that holds a lens, and a cylinder that has a movement reference surface parallel to the optical axis direction of the lens and holds the lens holding member movably along the movement reference surface. And a biasing member for biasing the lens holding member against the movement reference plane.

According to the present invention, since the lens holding member is urged by the urging member to press the cylindrical member against the movement reference plane, the clearance for fitting between the lens holding member and the cylindrical member is reduced. Even when it is present, the inclination of the lens holding member with respect to the movement reference plane can be kept constant. Therefore, even when the lens is moved for adjustment, the inclination of the lens is kept constant, and the optical characteristics do not change. In addition, since the clearance for fitting between the lens holding member and the tubular member does not need to be reduced more than necessary, the processing of the parts does not take much time, and the manufacturing cost does not increase.

Further, the lens holding member is fitted and held on the movement reference surface of the cylindrical member, and a cutout portion parallel to the optical axis direction is provided on one of the fitting surfaces fitted with each other. And the lens holding member may be pressed and supported by the urging member at both ends of the cutout.

According to this configuration, the lens holding member is urged and supported at both ends of the cutout portion.
This is preferable because the lens member can be held more stably.

Further, the center angle formed between one end and the other end of the both ends of the notch with respect to the center of the optical axis is from 60 ° to 120 °.
It is preferable that it is within the range of °. When the central angle is within this range, the lens member can be held more stably. The central angle is more preferably about 80 °.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment according to the present invention.
Longitudinal sectional view (a) showing the lens holding device of the embodiment;
FIG. 2 is a cross-sectional view (b) taken along line Ib-Ib of the vertical cross-sectional view (a). As shown in FIG. 1, the lens holding device includes a lens chamber 3 for housing the lens 1 therein,
A lens barrel 4 for holding the lens chamber 4 on the inner surface.

The lens 1 is fixed and held in the lens chamber 3 by screwing the holding ring 2 into a thread formed on the upper part of the inner surface of the lens chamber 3. A screw portion 3b is formed on an upper portion of the outer surface of the lens chamber 3, and the lens chamber 3 is a lens barrel 4
Is screwed into the threaded portion on the upper side of the inside. The lens chamber 3 is fitted and held at a fitting portion 3a below the screw portion 3b with a movement reference surface 9 formed on the inner surface of the lens barrel 4 parallel to the optical axis p. By rotating the lens chamber 3, the lens chamber 3 can move in the optical axis p direction along the movement reference plane of the lens barrel 4.

The lens barrel 4 has a pedestal 4e for attaching a lens holding device to an optical device 6 indicated by a two-dot chain line in FIG.
The lens holding device is attached to the optical device 6 on the pedestal 4e by a pair of screws 7a and 7b.

As shown in FIGS. 1A and 1B, the lens barrel 4
A slit portion 4a is formed in a side portion at a right angle to the optical axis p so as to penetrate the side portion.
From a, a wire spring 5 is inserted so as to make point contact with the point 3c of the fitting surface 3a of the lens chamber 3. The wire spring 5 is shown in FIG.
As shown in (b), screws 7a, 7b
And is held by the bent ends 5a and 5b. At this time, the wire spring 5 urges the lens chamber 3 by its elastic force in the direction of the arrow f (in the direction perpendicular to the optical axis p) at the point 3c of the fitting surface 3a of the lens chamber 3 near the center thereof. Contact. By the urging force of the linear spring 5, the lens chamber 3 is pressed against the movement reference plane 9 of the lens barrel 4 on the opposite side of the optical axis p at the point 3c.

As described above, when the lens chamber 3 is fitted and held in the lens barrel 4 with a certain clearance, the lens chamber 3 is moved in one direction with a certain pressing force by the urging action of the wire spring 5. Since the lens chamber 3 is pressed against the movement reference plane 9 of the cylinder 4, even if the lens chamber 3 is rotated and moved for optical adjustment of the lens 1, the posture (falling) of the lens chamber 3 always moves with respect to the movement reference plane 9. And kept constant. In this case, even if the lens chamber 3 is slightly tilted, there is no problem because other optical systems of the optical device 6 are adjusted in that state.

Therefore, the inclination of the lens 1 with respect to the optical axis p is also kept constant, and the optical performance of the lens 1 does not change with respect to the optical device 6, and the other optical systems of the optical device 6 are readjusted. There is no need for Also, a lens chamber 3 and a lens barrel 4
It is not necessary to make the clearance for fitting with the lens chamber so small, so that the processing of the lens chamber 3, the lens barrel 4, and the like does not take time and the manufacturing cost does not increase.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows the lens holding device shown in FIG. 1 in which a cutout portion is provided on the inner surface of the lens barrel 4 and the other portions have the same configuration. . FIG. 2 is a cross-sectional view corresponding to FIG. 1B, in which a clearance 8 for fitting the lens chamber 3 and the lens barrel 4 is emphasized.

A notch 4b is provided in a part of the movement reference surface 9 on the inner surface of the lens barrel 4 so as to face the fitting portion 3a on the outer surface of the lens chamber 3. The notch 4b is formed in the movement reference plane 9 of the lens barrel 4 so as to extend in the optical axis p direction. Therefore, both ends 4c and 4d of the notch 4b extend in the optical axis p direction.

When the lens chamber 3 is urged in the direction of the arrow f in the figure by the urging force of the wire spring 5 as in FIG. 1, the lens chamber 3 is moved to both ends 4c of the notch 4b of the lens barrel 4. , 4, while being in contact with each other. As a result, the lens chamber 3 is supported at the three points of both ends 4c and 4d of the notch 4b and the contact 3a with the wire spring 5, and the position stability of the lens chamber 3 is further improved. In addition, two points (4
The distance between (c, 3c) and the distance between the other two points (4d, 3c) are substantially the same.

In particular, when the clearance 8 between the fitting of the lens chamber 3 and the lens barrel 4 is relatively large, the holding of the lens chamber 3 tends to be unstable. However, according to the lens holding device of the present embodiment, Such instability can be eliminated, which is preferable.

Further, one end 4c and the other end 4c of the notch 4b
d with respect to the optical axis center (p) is 80 ° ±
20 ° is preferable, and the holding stability of the lens chamber 3 is good.
The center angle θ is most preferably about 80 °, and it has been experimentally found that the lens chamber has better stability.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 shows the lens holding device shown in FIG. 1 in which a cutout portion is provided on the outer surface of the lens barrel 3 and the other portions have the same configuration. . FIG. 3 is a cross-sectional view corresponding to FIG. 1B, in which a clearance 8 for fitting the lens chamber 3 and the lens barrel 4 is emphasized.

A cutout 3d is provided on a part of the outer surface of the lens chamber 3 so as to face the movement reference plane 9 on the inner surface of the lens barrel 4. The notch 3d is formed in the fitting portion 3a on the outer surface of the lens chamber 3 so as to extend in the optical axis p direction, and both ends 3e and 3f of the notch 3d extend in the optical axis p direction.

When the lens chamber 3 is urged in the direction of the arrow f in the figure by the urging force of the wire spring 5 in the same manner as in FIG. 1, the lens chamber 3 moves at both ends 3e and 3f of the notch 3d. It is pressed against the movement reference surface 9 of the lens barrel 4 while making contact. As a result, the lens chamber 3 is supported at the three points of both ends 3e and 3f of the cutout 3d and the contact point 3a with the wire spring 5, and the position of the lens chamber 3 is the same as in FIG. Stability is further improved. The distance between two points (3e, 3c) and the distance between another two points (3f, 3c) are substantially the same.

Thus, the same effect as in the case of FIG. 2 can be obtained. The center angle θ between the one end 3e and the other end 3f of the cutout 3d with respect to the center of the optical axis is preferably 80 ° ± 20 °, most preferably about 80 °, as in FIG.

The wire spring 5 as the urging member is made of springy steel or the like, but the urging member is not limited to this, and may be made of another spring member such as a leaf spring. .

[0026]

As described above, according to the present invention, the inclination of the lens chamber with respect to the optical axis does not change without reducing the clearance of fitting between the lens holding member and the cylindrical member, and the optical axis of the lens does not change. It is possible to provide a lens holding device in which optical performance does not change due to adjustment in the direction.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of a lens holding device according to a first embodiment of the present invention, and FIG.
FIG. 3B is a cross-sectional view taken along line Ib.

FIG. 2 is a cross-sectional view of a lens holding device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a lens holding device according to a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional lens holding device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 lens 2 press ring 3 lens chamber (lens holding member) 3a fitting surface 3d notch 3e, 3f both ends of notch 4 lens barrel (cylindrical member) 4b notch 4c, 4d both ends of notch Part 5 Wire spring (biasing member) 6 Optical equipment 7 Screw 9 Movement reference plane

Claims (3)

[Claims] A cylindrical member having a lens holding member for holding a lens, and a movement reference surface parallel to an optical axis direction of the lens, and holding the lens holding member movably along the movement reference surface. And a biasing member for biasing the lens holding member against the movement reference plane. 2. A notch parallel to the optical axis direction in one of the fitting surfaces in which the lens holding member is fitted and held on a movement reference surface of the cylindrical member. 2. The lens holding device according to claim 1, wherein the lens holding member is supported by being pressed by the urging member at both ends of the notch. 3. The lens according to claim 2, wherein a center angle formed between one end and the other end of both ends of the cutout portion with respect to the optical axis center is within a range of 60 ° to 120 °. Holding device.