JP2599287Y2 - Plug-in optical filter holder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in type optical filter holder which is mounted in the middle of a lens barrel.

[0002]

2. Description of the Related Art Conventionally, there has been known a polarizing filter configured to be inserted and mounted in the middle of a lens barrel having a long focal length lens (Japanese Utility Model Application Laid-Open No. 60-18 / 1985).
No. 6430). This plug-in type polarizing filter is supported by the holder body so as to be rotatable around the optical axis, and is configured so that the rotational position can be adjusted as necessary. In order to adjust the rotational position, an operation gear is provided on the holder body, and the operation gear meshes with external teeth formed on the outer periphery of the holding frame of the polarizing filter. That is, by rotating this operation gear, the rotation position of the polarizing filter changes,
Desired polarization adjustment is possible.

[0003]

However, according to the configuration in which the operating gear is provided on the holder body, the relative position between the operating gear and the external teeth is set so that the operating gear engages with the external teeth of the holding frame of the polarizing filter during assembly. It is necessary to adjust the rotational position of the filter, so that the assembly work is troublesome, and such a holder body has no gear formed on the outer periphery of the filter and is a general polarizing filter mounted on the tip of the lens barrel. There is a problem that can not be attached.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a plug-in type optical filter holder which is easy to assemble, has a simple structure, and can be commonly used for general polarizing filters. It is intended to be.

[0005]

SUMMARY OF THE INVENTION A plug-in type optical filter holder according to the present invention includes a holder body for rotatably supporting an optical filter around an optical axis, and a holder rotatably mounted on the holder body for holding the optical filter. Attached to the body
And an operation member that frictionally engages the optical filter when the operation is performed.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 show a plug-in polarization filter holder according to an embodiment of the present invention, and FIG. 3 shows a state in which a polarization filter 50 is attached to the plug-in polarization filter holder.

The holder body 10 includes an annular holding portion 11 for mounting the polarizing filter 50 and the holder body 10.
A curved portion 12 having a shape conforming to the outer peripheral surface of a lens barrel 60 (see FIG. 7) to which the lens is attached;
And an arc-shaped plate portion 13 for connecting the curved portion 12. A female screw 14 for screwing the polarizing filter 50 is formed on the inner peripheral surface of the annular holding portion 11. Curved part 1
2, an operation knob 20 for fixing the holder body 10 to the lens barrel 60 is provided. An operation dial (operation member) 40 for rotating and displacing the polarizing filter 50 is provided on the arc-shaped plate portion 13. Is provided. A part of the operation dial 40 is exposed from an opening 18 formed in the curved portion 12.

The operation knob 20 has a first cylindrical portion 21 protruding from the information, a second cylindrical portion 22 protruding downward, and a flange portion 23 formed between the first and second cylindrical portions 21 and 22. And the flange portion 23 is connected to the upper surface of the curved portion 12 by a screw 24. A knob 25 on a bottomed cylinder is rotatably fitted to the first cylindrical portion 21.
The upper end of a fixed shaft 31 is screwed into a hole 26 formed at the center of the knob 25, and a stop screw 27 is provided on the knob 25 to prevent the fixed shaft 31 from loosening. An engagement claw 32 is provided at a lower end of the fixed shaft 31, and the engagement claw 32 protrudes downward from the second cylindrical portion 22. A compression spring is provided between the first cylindrical portion 21 and the fixed shaft 31.
And (coil spring) 33 is provided, the compression spring 3
Numeral 3 constantly urges the knob 25, the fixed shaft 31, and the engagement claw 32 upward.

A disk member 34 for concealing the hole 26 is provided on the upper part of the knob member 25. An engagement claw 32 is provided on the upper surface of the disk member 34 and the upper surface of the curved portion 12, respectively. Indices 35 and 36 are formed to indicate whether or not the lens 10 faces a direction for fixing the lens 10 to the lens barrel 60. If the index 35 is formed directly on the knob 25, the relative angular position between the index 35 and the engaging claw 32 varies because the knob 25 and the fixed shaft 31 are assembled by screws. Therefore, in the present embodiment, an index 35 is provided on the disk member 34, and the disk member 34 is fixed to the knob 25 so that the index 35 is set at a predetermined angular position. 1, 2, 3, and 4, the engaging claw 32 is facing sideways. In this state, the engaging claw 32 does not interfere with the lens barrel 60. Index 35, 36
Are facing each other, the engaging claw 32 faces in a direction to interfere with the lens barrel 60, and in this state, the holder body 1
0 is fixed to the lens barrel 60.

The operation dial 40 is rotatably supported by a mounting plate 42 fixed to the arc-shaped plate portion 13 by screws 41. The mounting plate 42 and the arc-shaped plate portion 13 have elongated holes 43 and 44 extending in the radial direction of the annular holding portion 11, respectively.
(See FIG. 5).
4 is a support shaft 4 extending in the axial direction of the operation dial 40.
5 has been inserted. That is, the operation dial 40 is rotatably supported by the elongated holes 43 and 44 and is displaceable within the length range of the elongated holes 43 and 44.
Further, a torsion spring 46 that constantly biases the operation dial 40 toward the annular holding portion 11, that is, the polarization filter 50 is provided.

That is, when the polarizing filter 50 is not attached to the annular holding portion 11, the support shaft 45 abuts on the inner peripheral end of the elongated hole 43 as shown in FIG. It is located on the inner peripheral side of the outer peripheral surface 11a of the annular holding portion 11. On the other hand, when the polarizing filter 50 is attached to the annular holding portion 11, the polarizing filter 50 presses the operation dial 40 outward against the torsion spring 46, and as shown in FIG.
0 is frictionally engaged with the outer peripheral surface of the polarizing filter 50, and the support shaft 45 is located at the center of the elongated hole 43.

FIG. 4 is a longitudinal sectional view of a portion where the operation knob 20 is provided. The structure for attaching the polarizing filter 50 to the holder body 10 will be described with reference to FIG.

In the polarizing filter 50, a filter retaining ring 52 having an external thread formed on an outer peripheral surface is fitted to an outer peripheral edge of a disk-shaped filter main body 51. The external thread of the filter retaining ring 52 is screwed into a female screw formed in a filter frame 53 wider than the filter main body 51, whereby the filter main body 51, the filter retaining ring 52, and the filter frame 53 are integrally connected. A mounting ring 54 is fitted on the outer peripheral surface of the filter frame 53 so as to be slidable in the circumferential direction. A male screw formed on the outer peripheral surface of the mounting ring 54 is screwed to the female screw 14 of the annular holding portion 11. Thus, the polarizing filter 50 is attached to the holder body 10. That is, the polarization filter 50 is supported by the holder body 10 so as to be rotatable around the optical axis.

The filter frame 53 has a large diameter portion 53a and a medium diameter portion 5a.
3b and a small diameter portion 53c. The outer peripheral surface of the large-diameter portion 53a frictionally engages with the operation dial 40 (see FIG. 5), and the filter pressing ring 52 is screwed to the inner peripheral surface of the large-diameter portion 53a. The filter body 5 is provided on the inner peripheral surface of the middle diameter portion 53b.
1 is fitted. The small diameter portion 53c protrudes in the direction opposite to the large diameter portion 53a, and a caulking portion 53d that protrudes outward is formed at the tip of the small diameter portion 53c. Small diameter part 5
A mounting ring 54 is slidably fitted to the outer peripheral surface of 3c, and the mounting ring 54 is held on the filter frame 53 by a caulking portion 53d.

FIG. 5 is a longitudinal sectional view of a portion where the operation dial 40 is provided, and FIG. 6 is a view of the operation dial 40 as viewed from above. As shown in these figures, an outer peripheral portion of the operation dial 40 is provided with an annular friction member 47 formed of a member having a large friction coefficient such as rubber, and the operation dial 40 is provided via the friction member 47. Are frictionally engaged with the filter frame 53 of the polarizing filter 50. The torsion spring 46 is wound around a cylindrical support 48 projecting from the operation dial 40 in the axial direction, and the end of the torsion spring 46 is locked by a notch 49 formed at the lower end of the mounting plate 42. ing. By the action of the torsion spring 46, the operation dial 40 is moved to the polarizing filter 5.
0 to the operation dial 40.
And the frictional engagement of the polarizing filter 50 is maintained. The operation dial 40 is located on the outer peripheral side of the filter body 51,
The outer peripheral surface of the large diameter portion 53a is engaged with a position closest to the middle diameter portion 53b.

FIG. 7 shows a state in which a plug-in type polarizing filter holder to which the polarizing filter 50 is attached is fixed to the lens barrel 60. As shown in this figure, the holder main body 10 is inserted through an opening 61 formed in the lens barrel 60, and is located in the lens barrel 60 in front of the light blocking ring 62. In this state, the distal end of the engaging claw 32 is compressed by the compression
, Whereby the holder main body 10 is fixed to the lens barrel 60.

Next, the operation of this embodiment will be described. With the holder main body 10 removed from the lens barrel 60, the polarizing filter 50 is attached to the annular holding portion 11. Thereby, the operation dial 40 is pressed by the polarizing filter 50 and displaced outward, and protrudes from the opening 18 (see FIG. 3). Also, at this time, as shown in FIG.
The index 35 is set at a position facing the operation dial 40, and the engaging claw 32 faces the side opposite to the operation dial 40 as shown in FIG. 3.

In this state, the holder main body 10 is inserted into the lens barrel 60 through the opening 61. Next, the picking member 2
5 is pressed and rotated against the compression spring 33, and the engagement claw 32 is moved to the inner wall portion (the opening 61) of the lens barrel 60.
At the lower end portion 63) of the main body. Thereby, the polarization filter 5
0 is fixed in the lens barrel 60. In this state, the index 35 of the disk member 34 is
Facing.

Here, by rotating the operation dial 40, the polarization filter 50 is set at a desired position. A friction member 47 made of rubber or the like is provided on the operation dial 40.
Is fitted, no slippage occurs between the operation dial 40 and the polarization filter 50, and the polarization filter 50 rotates smoothly.

As described above, in this embodiment, the operation dial 4
As 0, instead of using a gear as in the prior art, a disk member provided with a friction member 47 on the outer peripheral surface is used,
The configuration is simple. In addition, when the polarizing filter holder is assembled, since the operating gear meshes with the external teeth of the holding frame of the polarizing filter, the troublesome operation of adjusting the relative rotational position between the operating gear and the external teeth is not required.

The present invention is not limited to the linear polarization filter 50, but can be applied to a circular polarization filter. Further, the filter holder of the present invention includes other filters that do not need to be rotated (such as a skylight filter),
That is, it is possible to mount a general polarizing filter mounted on the tip of the lens barrel without forming a gear on the outer peripheral portion.

When the operation dial 40 is formed of a member having a relatively large coefficient of friction, the friction member 47 can be omitted.

[0023]

As described above, according to the plug-in type optical filter holder of the present invention, it is not necessary to adjust the rotational position between the gears, so that the assembling is easy and the structure is simple. Can be The plug-in type optical filter holder of the present invention does not have a gear formed on the outer periphery of the filter, and can mount a general polarizing filter mounted on the tip of the lens barrel.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view showing a plug-in type polarizing filter holder according to an embodiment of the present invention, showing a state in which a polarizing filter is not attached.

FIG. 2 is a plan view showing a state in which the insertion type polarization filter holder is viewed from above.

FIG. 3 is a partial cross-sectional front view showing a state in which a polarizing filter is attached to the plug-in polarizing filter holder of FIG. 1;

FIG. 4 is a longitudinal sectional view showing a portion provided with an operation knob.

FIG. 5 is a vertical sectional view showing a portion provided with an operation dial.

FIG. 6 is a plan view showing an operation dial.

FIG. 7 is a cross-sectional view showing a state in which a plug-in type polarization filter holder to which a polarization filter is attached is attached to a lens barrel.

[Explanation of symbols]

 10 holder body 40 operation dial 46 torsion spring 47 friction member 50 polarizing filter

Claims (1)

(57) [Scope of request for utility model registration] 1. A holder main body for supporting an optical filter rotatably around an optical axis, and an optical filter mounted on the holder main body , the optical filter being mounted on the holder main body.
And an operating member that frictionally engages the optical filter.