JP3852149B2 - Camera lens mount device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an interchangeable lens camera to which a lens barrel can be attached and detached, and more particularly to a lens mount device for detachably attaching an interchangeable lens to a camera body.
[0002]
[Prior art]
Conventionally, this type of interchangeable lens type camera has a structure in which the interchangeable lens and the camera body can be detachably joined by a detachable lens mount with a spring such as a bayonet mount.
In such an interchangeable lens type camera, the lens barrel is rotated at a predetermined angle with respect to the camera body, and is attached and detached. At the time of this joining, in order to electrically connect the electrical device on the interchangeable lens side and the electrical device on the camera body side, a plurality of electrical connection terminal groups that can be used when the interchangeable lens is installed are joined to the lens mount. On the surface.
[0003]
In a conventional camera, the lens mount is formed by cutting a metal material. Further, the mount spring attached to such a lens mount is formed by a ring-shaped spring portion integrally formed in a circumferential shape.
[0004]
5 and 6 show a conventional lens mount device. In these drawings, reference numeral 1 denotes a lens mount made of a metal material, 2 denotes a ring-shaped mount spring integrally formed with a circumference, and 3 denotes a camera body. is there. The camera body 3 is provided with a mount mounting seat 3b on which the lens mount 1 and the mount spring 2 are assembled and fixed with screws 4.
[0005]
In the figure, reference numeral 2a denotes spring portions provided at a plurality of locations (three locations) in the circumferential direction of the mount spring 2, and by pressing the claw portions on the lens barrel side (not shown), the mount on the camera body 3 side after the lens barrel is mounted. This is to prevent rattling between the lens barrel and the lens barrel.
The portions other than these spring portions 2 a are portions for connection and positioning of the spring 2, and a notch groove 2 b is formed in a portion corresponding to the screw 4.
[0006]
In such a structure, the mount spring 2 is sandwiched between the camera body 3 and the mount 1, and the mount 1 is attached to the screw fixing portion of the mount mounting seat 3 b with the screw 4. At this time, the spring portion 2a of the mount spring 2 is positioned by the notch groove 2b with which the screw 4 screwed into the screw stopper is engaged so that it does not come out of a predetermined position even if the lens barrel is attached or detached. It has become.
[0007]
The camera body 3 is provided with three recesses 3a corresponding to the spring portions 2a of the mount spring 2. At the time of assembly, the spring portion 2a is positioned in these recesses 3a, the mount spring 2 is placed on the mount mounting seat 3b, the mount 1 is placed thereon, and the screws 4 are fastened to fix them.
[0008]
In such a conventional structure, since the mount spring 2 is formed in a ring shape, a space for inserting the spring 2 is provided between the mount 1 and the camera body 3 as shown in FIG. It has been. The thickness of the mount 1 at this time is L1 (see FIG. 6).
[0009]
[Problems to be solved by the invention]
However, as described above, when the lens mount 1 is formed of a metal material, the processing is troublesome, and the cost of the parts is increased. Thus, it has been considered to mold such a lens mount with a synthetic resin material, but there is a problem that the strength is weak if the metal mount 1 is simply replaced with a synthetic resin material.
[0010]
For this reason, in order to form the mount 1 with a synthetic resin material, it is necessary to make the wall thickness thicker than that of a metal material. However, when the thickness of the mount is increased in this way, the mount spring cannot be formed in a ring shape integrally with the circumference. Further, when such a mount spring is divided, there arises a problem that the position of each mount spring cannot be accurately positioned.
[0011]
The present invention has been made in view of such circumstances, and even if the lens mount is formed of a synthetic resin material and is thickened, the function as a conventional lens mount is ensured and the assemblability is equivalent. An object of the present invention is to obtain a lens mount device for a camera that can be used.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a lens mount device for a camera according to the present invention includes a mount for allowing a lens barrel to be coupled to a camera body, and a plurality of divided lens barrels for biasing the lens barrel in an optical axis direction. When the mount is formed of a synthetic resin material , a bent portion is provided at both ends of the spring member, and a groove portion for engaging each bent portion of the spring member is provided in the camera body. Is.
[0013]
Further, in the lens mount device for a camera according to the present invention, the groove portions for engaging the respective bent portions of the spring member have different lengths and are respectively provided at both ends of the recess for placing the spring member .
[0014]
According to the present invention, the mount spring is divided into a plurality of parts, a bending portion serving as a restricting means for fixing these mount springs is provided, and a corresponding positioning groove is provided in the camera body. Since the position of each mount spring is regulated by engaging the bent part of the spring with the groove of the lens, the lens mount can be formed by replacing the metal material with the synthetic resin material, and the assembly property The cost can be reduced and the weight can be reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show one embodiment of a lens mount device for a camera according to the present invention. In these drawings, the same or corresponding parts as those in FIGS. 5 and 6 are designated by the same reference numerals. Detailed description will be omitted as appropriate.
[0016]
According to the present embodiment, in the conventional lens mount device having the above-described configuration, the mount spring 2 is divided into three parts and positioned with respect to the camera body 3 as shown in FIGS. As restricting means, bent portions 2c and 2d are provided at both ends of each spring 2, and groove portions 3c and 3d are provided on the camera body 3 side correspondingly. When the bent portions 2c and 2d are engaged with the grooves 3c and 3d, each spring 2 is positioned at a required position with respect to the camera body 3 as shown in FIGS. Can be attached.
[0017]
As described above, the bending portions 2c and 2d described above restrict the movement of the spring 2 from a predetermined position of the camera body 3 in a direction perpendicular to the optical axis direction by engaging the bending portions 2c and 2d with the groove portions 3c and 3d. It is configured to be able to.
[0018]
According to such a configuration, as shown in FIG. 4, there is no need for an installation space for interposing the spring 2 between the mount 1 and the camera body 3, and the thickness of the mount 1 is increased as indicated by L2. can do. Therefore, even if such a mount 1 is formed by molding with a synthetic resin material instead of a metal material, the same strength as that with a metal material can be secured.
[0019]
Assembling of the mounting device having the above-described configuration is as follows. That is, the mount springs 2 (spring portions 2a) are placed on the respective recesses 3a of the camera body 3, and the bent portions 2c and 2d are engaged with the groove portions 3c and 3d. Then, it is preferable to mount the mount 1 on the upper side of these springs 2 and fix the mount 1 to the camera body 3 with screws 4.
Of course, the present invention is not limited to this, and a portion other than the spring portion 2a of each of the mount springs 2 described above is attached in advance to the back side of the mount 1, and an assembly comprising the mount 1 and the spring 2 is attached to the camera body 3. You can also. Also at this time, by engaging the respective bent portions 2c and 2d with the groove portions 3c and 3d, the assembly position of each spring 2 can be correctly positioned and the assembled state can be secured. Therefore, each spring 2 is free from the problem of detachment due to the spring action of the spring portion 2a, and each spring 2 does not move or shift from a predetermined position.
[0020]
In addition, as shown in FIG. 3, one groove portion 3d provided in the camera body 3 takes into account the amount of extension in the circumferential direction of the spring portion 2a when the lens barrel is mounted, and the other groove 3c The length is longer than the length in the circumferential direction. If there is no escape due to the deformation of the spring 2 when the lens is mounted, there is a possibility that a larger load is generated than in the conventional case, and the attaching / detaching torque of the lens barrel becomes higher than the standard or the spring 2 is fatigued. However, such a problem can be solved by adopting the above-described configuration.
[0021]
The present invention is not limited to the structure described in the above-described embodiment, and it goes without saying that the shape and structure of each part including the camera body 3 can be appropriately modified and changed.
[0022]
【The invention's effect】
As described above, according to the lens mount device for a camera according to the present invention, the mount for configuring the lens barrel to be connectable to the camera body and the divided lens barrel for urging the lens barrel in the optical axis direction are divided. A plurality of spring members, and when the mount is formed of a synthetic resin material, the spring member is configured to include a restricting unit that restricts movement of the spring member from a predetermined position of the camera body in a direction perpendicular to the optical axis direction. Therefore, the following excellent effects are achieved.
[0023]
That is, according to the present invention, since the bent portion is provided as a restricting means at both ends of the spring member and the positioning groove portion for accommodating and engaging the bent portion of the spring member is provided in the camera body, the mount spring is divided into a plurality of parts. The mounting position of each mount spring to the camera body can be positioned and regulated. Therefore, even if the lens mount is formed from a metal material instead of a synthetic resin material, the thickness can be secured by securing the thickness, and the assemblability is not deteriorated, resulting in cost reduction and weight reduction. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a front view showing a lens mount device for a camera according to an embodiment of the present invention when a mount spring is attached to the camera body.
FIG. 2 is a perspective view showing the mount spring shown in FIG. 1;
FIG. 3 is a cross-sectional view showing a mount spring mounting portion when the lens mount is assembled in FIG. 1;
4 is a cross-sectional view showing a portion other than a mount spring mounting portion when the lens mount is assembled in FIG. 1;
FIG. 5 is an exploded perspective view for explaining a lens mount device in a conventional camera.
6 is a cross-sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Lens mount, 2 ... Mount spring, 2a ... Spring part, 2c, 2d ... Bending part (limitation means), 3 ... Camera body, 3a ... Indentation, 3c, 3d ... Positioning groove part, 4 ... Screw.

Claims (2)

A camera having a mount for allowing the lens barrel to be coupled to the camera body, and a plurality of divided spring members for biasing the lens barrel in the optical axis direction, wherein the mount is formed of a synthetic resin material In
A lens mount device for a camera , wherein a bent portion is provided at both ends of the spring member , and a groove portion for engaging each bent portion of the spring member is provided in the camera body . The camera lens mount device according to claim 1,
A lens mount device for a camera , wherein the groove portions for engaging the respective bent portions of the spring members have different lengths and are respectively provided at both ends of a recess for placing the spring members .

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