JP2021196501A - Lens device and imaging apparatus - Google Patents

Abstract

To provide a lens device that is advantageous in terms of a reduction in size and weight and sealing.SOLUTION: A lens device (1) has: a first housing (2) that includes a first lens group; a second housing (3) that includes a conversion lens group and an insertion and withdrawal mechanism (4) for inserting and withdrawing the conversion lens group with respect to a light path formed by the first lens group, and is fixed to the first housing; and a third housing (5) that includes a third lens group (6) and is fixed to the second housing. A through hole (10) is formed which penetrates the second housing along an optical axis of the lens device. The through hole has fixing members (9) arranged therein to fix the second housing to the first housing. The lens device has a sealing member (7) that seals one end of the through hole on the opposite side of the first housing with respect to the through hole.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens device and an image pickup device.

A zoom lens device for an image pickup device such as a TV camera has a built-in mechanism for inserting and removing a conversion lens group (for example, an extender lens group) for changing the focal length range of the zoom lens device with respect to an optical path. There is. Such a zoom lens device is used because mobility is important when shooting with the camera carried on the shoulder in a news scene or the like. The zoom lens device has a mechanism for inserting and removing the extender lens group with respect to the optical path between the front relay lens group and the rear relay lens group. The housing including the insertion / removal mechanism is fixed to the housing including the zoom mechanism in the zoom lens device, and the housing including the rear relay lens group is fixed to the housing including the insertion / removal mechanism. In such a zoom lens device, aberration adjustment may be performed by the eccentricity of the rear relay lens group.

For the mobility of the image pickup device, it is required to reduce the size and weight of the zoom lens device. For that purpose, it is advantageous to reduce the diameter of the zoom lens device. Therefore, it is preferable that the fixing member (screw or the like) for fixing as described above is arranged closer to the optical axis of the lens device.

Further, in order to make the zoom lens device dust-proof and drip-proof, a sealed structure of the housing of the zoom lens device is required. Patent Document 1 discloses a lens holding mechanism that has waterproofness and stability of the position of a lens by arranging a sealing member between the lens barrel and the lens flange.

Japanese Unexamined Patent Publication No. 2020-016829

In the lens holding mechanism disclosed in Patent Document 1, the gap between the lens barrel and the lens flange is sealed in the radial direction by an annular sealing member (O-ring or the like), and therefore, for aberration adjustment. When the lens barrel is eccentric, the sealing effect of the sealing member may be reduced. It is an object of the present invention to provide, for example, a lens device that is advantageous in terms of small size, light weight, and sealing.

One aspect of the present invention is a first housing including a first lens group and a first housing.
A second housing fixed to the first housing, including a conversion lens group and an insertion / removal mechanism for inserting and removing the conversion lens group from the optical path formed by the first lens group.
A lens device including a third lens group and having a third housing fixed to the second housing.
A through hole is formed along the optical axis of the lens device and penetrates the second housing.
A fixing member for fixing the second housing to the first housing is arranged in the through hole.
It has a sealing member that seals one end of the through hole on the side opposite to the first housing with respect to the through hole.
It is a lens device characterized by this.

According to the present invention, for example, it is possible to provide a lens device which is advantageous in terms of small size, light weight, and sealing.

Sectional drawing of the main part of the lens apparatus which concerns on embodiment Enlarged view of the portion including the sealing member in the cross-sectional view of FIG. Front view of the lens device according to the embodiment Front view of the lens device according to the embodiment with the third housing removed. The figure which shows the movement locus of a conversion lens group Cross-sectional view of the sealing member The figure which shows the structural example of the image pickup apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In principle (unless otherwise noted), the same members and the like are designated by the same reference numerals throughout the drawings for explaining the embodiments, and the repeated description thereof will be omitted.

[Embodiment]
Hereinafter, embodiments will be described with reference to FIGS. 1 to 7. FIG. 1 is a cross-sectional view of a main part of the lens device according to the embodiment. The cross-sectional view shows a cross-sectional view taken along the alternate long and short dash line XX in FIG. FIG. 2 is an enlarged view of a portion including the sealing member (7) in the cross-sectional view of FIG. FIG. 3 is a front view of the lens device according to the embodiment. FIG. 4 is a front view of the lens device according to the embodiment with the third housing removed. FIG. 5 is a diagram showing the movement locus of the conversion lens group. FIG. 6 is a cross-sectional view of the sealing member. The cross-sectional view shows a cross-sectional view taken along the alternate long and short dash line YY in FIG. FIG. 7 is a diagram showing a configuration example of the image pickup apparatus.

In FIG. 1, 1 is a main part of a lens device, and 2 is a first housing. The first housing 2 includes a first lens group. The first housing 2 includes, for example, a focus operating member, and includes a focus lens group as the first lens group that moves in the direction of the optical axis A of the lens device by operating the focus operating member. Further, the first housing 2 includes, for example, a zoom operating member, and includes a zoom lens group as the first lens group that moves in the direction of the optical axis A by operating the zoom operating member. Further, the first housing 2 includes, for example, a diaphragm operating member, and includes an aperture diaphragm whose opening diameter is changed by operating the diaphragm operating member.

Reference numeral 3 is a second housing. The second housing 3 is fixed to the first housing 2 by a fixing member 9 described later. Reference numeral 8 is a conversion lens portion (movable portion inserted / removed by the insertion / removal mechanism 4 described later) included in the second housing 3 and including a conversion lens group inserted / removed with respect to the optical path formed by the first lens group. be. The conversion lens group is for switching the focal length of the lens device, and may be, for example, an extender lens group inserted into an optical path to convert the focal length to 1.5 times or 2 times. 4 is an insertion / removal mechanism included in the second housing 3 and including an operation lever for inserting / removing the conversion lens portion 8 with respect to the optical path.

Reference numeral 5 is a third housing. Reference numeral 6 is a third lens group included in the third housing 5. The third lens group 6 can be a relay lens group. The third housing 5 may be fixed in an eccentric state with respect to the second housing 3 in order to adjust (within an allowable range) the aberration of the lens device. By eccentricizing the third housing 5 with respect to the second housing 3, the third lens group 6 can be eccentric with respect to at least one of the first lens group and the conversion lens group described above. Therefore, as a result of the aberration adjustment, the third lens group 6 may be eccentric with respect to at least one of the first lens group and the conversion lens group.

The conversion lens unit 8 is configured to be rotatable in a plane orthogonal to the optical axis A by operating the insertion / extraction mechanism 4. By the rotation, the conversion lens group can be inserted into the optical path (the optical path formed by the first lens group) of the lens device, or the conversion lens group can be removed from the optical path. Note that FIG. 5 shows the movement locus of the conversion lens unit 8 due to the rotation as the region B. Further, it is preferable that the second housing 3 includes, for example, an electric board and electric wiring for detecting at least one of the inserted state and the removed state of the conversion lens group. The electric board may include a component for controlling each drive unit of the lens device and a component for detecting an operating state (rotation angle, etc.) of each operating member.

Here, reference numeral 10 is a through hole 10 formed in the second housing 3 along the optical axis A. Reference numeral 9 is a fixing member arranged in the through hole 10 for fixing the second housing 3 to the first housing 2. The fixing member 9 is a screw (fastening member) here, but is not limited to this, and may include other members suitable for the fixing such as an adhesive. Reference numeral 7 is a sealing member that fits into one end of the through hole 10 on the side opposite to the first housing 2 with respect to the through hole 10 and seals the one end. The sealing member 7 may be a rubber cap. The through hole 10 is for inserting the fixing member from the opposite side in order to fix the second housing 3 to the first housing 2. Arranging the sealing member 7 that seals one end of the through hole 10 provides an annular sealing member to the outside of the one end with respect to the optical axis A when orthographically projected onto a surface orthogonal to the optical axis A. Compared with the case of arranging, it is advantageous to obtain a small lens device in the radial direction with respect to the optical axis A. Further, when orthographically projected onto a surface orthogonal to the optical axis A, the fixing member 9 (through hole 10) is arranged in the movement locus (inside the region B) of the conversion lens portion 8 in the radial direction. Such arrangement is advantageous for obtaining a small lens device as compared with the case where the fixing member 9 and the sealing member 7 are arranged outside the region B in the radial direction.

As shown in FIG. 6, the sealing member 7 has a fitting portion fitted to one end thereof and a protruding portion 7a (convex portion) protruding from the fitting portion, and the protruding portion 7a. Is in contact with the third housing 5. Further, it is preferable that the sealing member 7 is sandwiched between the second housing 3 and the third housing 5 and compressed. Further, as shown in FIG. 4, a plurality of through holes 10 in which the fixing member 9 is arranged are formed in the second housing 3, and the sealing member 7 seals the plurality of through holes 10. It is also preferable to have. In addition, in FIG. 4, the sealing member 7 is formed by connecting a plurality of fitting portions to be fitted to the plurality of through holes 10 to each other. Further, it is also preferable that the sealing member 7 has a protruding portion 7b in a direction along a plane orthogonal to the optical axis A. The material of at least a part of the sealing member 7 preferably contains rubber such as chloroprene and silicone rubber, and at least one of elastic resins such as these. The protrusion 7a may have a hemispherical shape as shown in FIG. 6 or a shape that can be seen as a character or a symbol when viewed from a direction along the optical axis.

Here, in the lens device having the above configuration, the first housing 2 and the second housing 3 are fixed to each other in a fitted state, and the second housing 3 and the third housing 5 are fixed to each other. Is not fixed to each other in the fitted state due to the above-mentioned eccentricity adjustment. Therefore, in order to seal the gap between the second housing 3 and the third housing 5, the sealing member 7 as described above is provided. With such a configuration, foreign matter entering the inside of the lens device from the gap C exemplified in FIG. 2 can be reduced, the drip-proof property and the dust-proof property of the lens device can be improved, and the inside of the second housing 3 can be improved. It is also possible to maintain the electric board and electric wiring provided in the. Further, since the sealing member 7 is fitted in the through hole 10, the second housing is different from the case where a single O-ring is arranged between the second housing 3 and the third housing 5. Even if the third housing 5 is eccentric with respect to the body 3, the sealing effect can be stably obtained. Further, in the configuration in which the protruding portion 7a of the sealing member 7 comes into contact with the third housing 5, the contact area of the third housing 5 with respect to the second housing 3 is small, so that the third housing with respect to the second housing 3 It does not interfere with the eccentric adjustment of the body 5. Further, the sealing member 7 may be sandwiched between the second housing 3 and the third housing 5 and compressed. In such a configuration, since the sealing member 7 is pressed and held by the second housing 3, the sealing effect is more stable even if the third housing 5 is eccentric with respect to the second housing 3. Is what you get. Further, as shown in FIG. 2, the fitting portion of the sealing member 7 is fitted to the small diameter portion of the through hole, and the flange portion of the sealing member 7 is arranged to the large diameter portion of the through hole. The protrusion 7a of 7 may be configured to come into contact with the third housing 5. Such a configuration not only facilitates eccentricity adjustment of the third housing 5 with respect to the second housing 3 as described above, but also makes the gap between the second housing 3 and the third housing 5 wider. Since it can be made minute, it is more advantageous in terms of sealing effect. As shown in FIG. 2, only the protruding portion 7a of the sealing member 7 is the first while preventing the flange portion of the sealing member 7 from protruding toward the third housing 5 from the large diameter portion of the through hole. 3 It is preferable that the housing 5 is in contact with the housing 5. Then, it is advantageous in terms of the effect of making the gap between the second housing 3 and the third housing 5 minute, and thus the sealing effect. It should be noted that the small diameter portion and the large diameter portion do not ask the absolute value of the diameter, and the diameter of the large diameter portion needs to be relatively larger than the diameter of the small diameter portion. Here, the cross-sectional shape of the through hole 10 is not limited to a circular shape. When the cross section is not circular, the small-diameter portion and the large-diameter portion constitute a through-hole portion such that the entire small-diameter portion is included inside the large-diameter portion when orthographically projected onto a surface orthogonal to the optical axis. And. Further, by having the integrated sealing member 7 for sealing the plurality of through holes 10 in which the plurality of fixing members 9 are arranged, the sealing member 7 can be easily attached to and detached from the second housing 3. can. Further, by having the sealing member 7 having the protruding portion 7b in the direction along the plane orthogonal to the optical axis A, the sealing member 7 can be easily attached to and detached from the second housing 3. Further, since a plurality of through holes 10 sealed by the sealing member 7 are formed so as to surround the optical path of the lens device, the gap can be reduced and the sealing effect can be further enhanced. Further, in addition to that, by having the sealing member 7 (integrated sealing member) that integrally seals the plurality of through holes 10, the gap can be further reduced and the sealing effect can be further enhanced.

[Embodiment of an image pickup apparatus]
FIG. 7 is a diagram showing a configuration example of the image pickup apparatus. The image pickup device includes a lens device 100 including a main part 1 of the lens device exemplified above, and an image pickup element 200a (including an image pickup device main body (camera device main body) 200) for taking an image formed by the lens device. It can be an image pickup device to have. In that case, the lens device 100 may or may not be interchangeably attached to the image pickup device main body 200.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

100 Lens device 2 1st housing 3 2nd housing 5 3rd housing 6 3rd lens group 7 Sealing member 8 Conversion lens part 9 Fixing member 10 Through hole

Claims (10)

The first housing including the first lens group and
A second housing fixed to the first housing, including a conversion lens group and an insertion / removal mechanism for inserting and removing the conversion lens group from the optical path formed by the first lens group.
A lens device including a third lens group and having a third housing fixed to the second housing.
A through hole is formed along the optical axis of the lens device and penetrates the second housing.
A fixing member for fixing the second housing to the first housing is arranged in the through hole.
It has a sealing member that seals one end of the through hole on the side opposite to the first housing with respect to the through hole.
A lens device characterized by that. The lens device according to claim 1, wherein the conversion lens group is an extender lens group. The sealing member has a fitting portion fitted to the one end and a protruding portion protruding from the fitting portion, and the protruding portion is in contact with the third housing. The lens apparatus according to claim 1 or 2. The sealing member has a fitting portion, a flange portion, and a protruding portion in order along the optical axis, the fitting portion is fitted to the small diameter portion of the through hole, and the flange portion is formed. The lens device according to claim 3, wherein the lens device is arranged in a large-diameter portion of the through hole, and the protruding portion is in contact with the third housing. The lens device according to any one of claims 1 to 4, wherein the sealing member is sandwiched between the second housing and the third housing and compressed. A plurality of the through holes are formed in the second housing.
The lens device according to any one of claims 1 to 5, wherein the sealing member integrally seals the plurality of the through holes. The lens device according to claim 6, wherein the plurality of the through holes are formed so as to surround the optical path. The lens apparatus according to any one of claims 1 to 7, wherein the material of at least a part of the sealing member contains at least one of rubber and resin. The claim is characterized in that the fixing member is arranged in a moving locus of a movable portion including the conversion lens group inserted / removed by the insertion / removal mechanism when an orthogonal projection is performed on a surface orthogonal to the optical axis. The lens device according to any one of 1 to 8. The lens apparatus according to any one of claims 1 to 9.
An image sensor that captures an image formed by the lens device,
An imaging device characterized by having.

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