JP2009251336A - Lens mount mechanism and lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism for preventing a screw of a lens mount from getting loose with which the screw of the lens mount is surely prevented from getting loose, and a rotating position of a lens barrel is easily determined when mounting, and which does not adversely influence an optical system of a camera. <P>SOLUTION: The lens mount mechanism is equipped with a mount ring 12 connected to the lens barrel that holds a lens and screwed and coupled with a camera body 2 side, a rotation adjusting means 51 for moving the lens barrel to the desired rotating position around a center line 6 relative to the mount ring 12, and a locking means 52 locking relative rotation of the lens barrel to the camera body 2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a screw loosening prevention mechanism for preventing a lens mount from loosening when a lens barrel is attached to a camera body.

  When the lens barrel is attached to the camera body, it is performed by screwing the mount screw of the mount ring attached to the rear end of the lens barrel into the front end of the camera body.

  However, in cameras used in FA (Factory Automation) devices, the vibration of the FA device is transmitted to the mount part and the screws may loosen. This loosening causes the focal point adjusted at the time of installation to become out of focus during a long period of use. There is.

  Further, when the mount screw is tightened, the rotational position of the lens barrel cannot be stopped at an arbitrary position. An index line may be displayed on the outer surface of the lens barrel, or the focus ring operation knob or the electric wire take-out part of the electric device may protrude, but the rotational position of the lens barrel should be stopped arbitrarily. If this is not possible, the position of the index line, the operation knob, and the wire take-out portion are not fixed, which is inconvenient for the camera.

JP-A-9-281580

  In order to prevent the lens mount from loosening, it is devised to apply an adhesive to the threaded portion and fix it, or to modify the camera body side and add a locking mechanism to prevent loosening from the side.

  However, with the method of applying and fixing the adhesive to the threaded part, it is necessary to wash the adhesive etc. when replacing the lens, and it is not possible to remove the lens barrel without using a solvent etc. Since it is necessary to clean, it is not easy to replace the lens.

  In the technology in which the camera body is modified and a lock mechanism for preventing loosening is added from the side, if the lock screw is screwed in strongly, the lens frame may be distorted, which may affect the optical characteristics.

  As a technique for setting the rotation position of the lens barrel to an arbitrary position after tightening the mount screw, the mount ring and the lens holding frame are pressed against each other with a leaf spring, and the mount ring and the lens holding frame are caused by friction. Patent Document 1 discloses a technique that enables rotational positioning.

  However, since the rotational positioning mechanism using a leaf spring needs to use a leaf spring, the number of parts and the number of assembling steps increase, and the structure of the mount portion becomes complicated.

  The present invention has been made in view of the circumstances as described above, and can reliably prevent the lens mount screw from loosening, and can easily position the rotational position of the lens barrel during mounting. An object of the present invention is to provide a lens mount screw loosening prevention mechanism that does not adversely affect the optical system of the camera, does not complicate the structure of the mount, and does not increase the number of components.

Corresponding to this object, the lens mounting mechanism of the present invention includes a mount ring connected to a lens barrel that holds a lens and screwed to the camera body side, and the lens barrel around the center line with respect to the mount ring. Rotation adjusting means for moving to a desired rotation position;
Locking means for locking relative rotation between the lens barrel and the camera body;
It is characterized by having.
Another lens mounting mechanism of the present invention is a lens mounting mechanism for attaching a lens barrel body to a camera body by screwing a mount ring attached to the lens barrel body into the camera body,
A lens barrel lock screw, a lens barrel sliding outer peripheral surface and a guide groove with ends are provided around the center line on the outer peripheral surface of the lens barrel body,
The mount ring has a mount screw that can be screwed into the camera body around the center line on an inner peripheral surface or an outer peripheral surface, and can be slidably fitted to a sliding outer peripheral surface of the barrel main body on the inner peripheral surface. A projecting member having a sliding inner peripheral surface and reaching the guide groove of the lens barrel and guiding relative rotation along the guide groove around the center line of the lens barrel body and the mount ring;
A lock screw that engages with the lens barrel lock screw of the lens barrel is formed on the inner peripheral surface, and is screwed into the lens barrel lock screw to come into contact with the camera body in the center line direction outside the mount ring. A lock ring that is displaceable to a position and a position that is separated from the camera body, and that presses the camera body in the direction of the center line to lock relative rotation between the lens barrel body and the camera body. It is said.

  According to the first aspect of the present invention, the lens barrel can be moved to a desired rotation position around the center line with respect to the mount ring screwed to the camera body by the rotation adjusting means, and the lens barrel can be moved by the locking means. Since the relative rotation between the camera and the camera body can be locked, the usability of the camera is good and the focus position shift can be prevented.

  According to the second aspect of the present invention, the locking means is not pressed in the radial direction of the lens barrel, but the lock ring is pressed against the camera body in the center line direction to lock the relative rotation. It does not cause distortion that causes

  According to the invention described in claim 3, since the rotation adjusting means is constituted by the guide groove portion provided on the outer peripheral surface of the lens barrel and the protruding member that protrudes from the mount ring and engages with the guide groove portion, the rotation adjustment is easy. And sure.

  In the invention described in claim 4, by turning the lock ring and tightening it toward the camera mount, the mount screw is pressed in the thrust direction and the mount screw is locked to prevent loosening. It can be surely prevented. At this time, since the lock ring presses the camera body in the center line direction and locks the lens barrel and the camera body by friction, unlike the lock mechanism that locks the lens barrel by pushing in the radial direction, the lens frame is distorted. There is no fear and therefore no adverse effects on the optical properties.

  In the invention described in claim 5, two grooves are processed in the lens barrel, and after attaching the mount screw to the lens barrel, the protruding members are attached to the grooves one by one from the outside of the mount ring, After the lens barrel is screwed into the camera body, the rotational position of the lens barrel can be set to an arbitrary position of about 150 ° or 300 ° on the camera body.

  According to the sixth aspect of the present invention, since a lens barrel that can be rotated and locked is obtained, it is possible to improve the usability of the camera and prevent the focus position from being shifted.

The details of the present invention will be described below with reference to the drawings.
Example 1
1 and 2, reference numeral 1 denotes a lens barrel. The lens barrel 1 is attached by screwing a mount ring 12 into the camera body 2.
Between the lens barrel and the mount ring, there is provided a rotation adjusting means 51 for moving the lens barrel to a desired rotation position around the center line with respect to the mount ring, and between the lens barrel and the camera body. Locking means for locking the relative rotation of the two is provided.
The rotation adjusting means 51 will be mainly described later. A lens barrel sliding outer peripheral surface 7, a lens barrel sliding small-diameter outer peripheral surface 8, a mount screw 13, a mount ring inner peripheral surface 14, a sliding inner peripheral surface 15, guide grooves 18a and 18b, an accommodation hole 22 and a protruding member 23 are provided. ing.
The lock means 52 mainly includes a lens barrel lock screw 11, a lock ring 24, a lock screw 26, a first screw portion 53, and a second screw portion 54, which will be described later.
That is,
The lens barrel 1 has a cylindrical barrel body 3, and the barrel body 3 has a lens holding frame 5 that holds a lens 4 therein. A lens barrel sliding outer peripheral surface 7 is formed in the vicinity of the rear end portion in the center line 6 direction of the lens barrel body 3, and a small diameter lens barrel sliding small diameter is formed at the rear end portion adjacent to the lens barrel sliding outer peripheral surface 7. An outer peripheral surface 8 is formed. Further, a lens barrel lock screw 11 is formed as an example of the first screw portion 53 in the front portion adjacent to the lens barrel sliding outer peripheral surface 7.

  The mount ring 12 has a mount screw 13 on the outer peripheral surface of the rear portion 19 in the center line 6 direction, has an inner peripheral surface 14 of the mount ring on the inner peripheral surface, and slides on the inner peripheral surface of the front portion 20. It has an inner peripheral surface 15.

The lens barrel 1 is attached to the camera body 2 by screwing the mount ring 12 into a mount internal screw 17 of the camera mount 16 attached and fixed to the tip of the camera body 2.
The sliding inner peripheral surface 15 of the mount ring 12 is slidably fitted to the lens barrel sliding outer peripheral surface 7 of the lens barrel body 3, and the mount ring inner peripheral surface 14 slides on the lens barrel sliding small-diameter outer peripheral surface 8. Fit as possible.

  Two guide grooves 18 a and 18 b are provided on the lens barrel sliding outer peripheral surface 7 of the lens barrel body 3. The two guide grooves 18a and 18b guide relative rotation of the lens barrel body 3 and the mount ring 12 around the center line 6 of the lens barrel 1 in a plane perpendicular to the center line 6 on which the guide grooves 18a and 18b are provided. At the end portions of the guide grooves 18a and 18b, the mount ring 12 and the lens barrel body 3 are connected via a projecting member 23 described later, and both are integrally rotated.

  The guide grooves 18 a and 18 b are formed symmetrically around the center line 6 by a certain angle θ, and guide the relative rotation between the mount ring 12 and the lens barrel body 3 within the range of the angle θ.

  The positions of the planes forming the guide grooves 18a and the planes forming the guide grooves 18b are not aligned with the direction of the center line 6, but the positions of the planes forming the guide grooves 18a and 18b in the direction of the center line 6 That is, when the thrust position is shifted, both end portions of both guide grooves 18a and 18b can be overlapped in the plane direction. Therefore, the rotation range of the barrel main body 3 and the mount ring 12 is further increased by, for example, 300 A wide range of relative rotations such as about 0 °, that is, adjustment of the rotational position of the lens barrel body 3 can be allowed.

  A receiving hole 22 such as two screw holes is formed in the front portion 20 of the mount ring 12 so as to correspond to the two guide grooves 18a and 18b in the radial direction. Or the like, and the tip of the protruding member 23 can protrude into the guide groove 18a (18b). When the protruding member 23 is mounted in the accommodation hole 22 and the tip thereof reaches the guide grooves 18a and 18b, relative rotation along the guide grooves 18a and 18b around the center line 6 between the lens barrel body 3 and the mount ring 12 is performed. This is possible, and is restricted by the edges of the guide grooves 18a and 18b, so that the relative displacement in the direction of the center line 6 between the lens barrel body 3 and the mount ring 12 is suppressed. When the tip of the projecting member 23 comes into contact with the bottoms of the guide grooves 18a and 18b, the relative rotation between the lens barrel body 3 and the mount ring 12 is stopped, and the mount ring 12 and the lens barrel body 3 can rotate integrally. Become.

  A lock ring 24 is screwed into the lens barrel body 3. A lens barrel lock screw 11 is formed around the center line 6 in a front portion of the lens barrel main body 3 with respect to the outer peripheral sliding surface 7 of the lens barrel. On the other hand, the lock ring 24 has a cylindrical shape, As an example of the second screw portion 54 screwed to the first screw portion 53 formed on the peripheral surface, the lock screw 26 is screwed to the lens barrel lock screw 11 of the lens barrel body 3 and is concentric with the lens barrel body 3. Is arranged.

  When the lock ring 24 is rotated around the center line 6, the lock ring 24 moves forward and backward in the direction of the center line 6, and the rear end surface 29 of the lock ring 24 is separated from the front end surface 31 of the camera mount 16 or abuts against the front end surface 30. The surface 30 can be pressed in the direction of the center line 6. When the lock ring 24 presses and presses the front end surface 30 of the camera mount 16, the lens barrel body 3 is locked to the camera mount 16 by frictional force.

  In the lens mount screw loosening prevention mechanism constructed as described above, the lens mount screw loosening prevention operation and the lens barrel rotation positioning operation when the lens barrel 1 is attached to the camera body 2 are performed as follows.

  First, the mount screw 13 of the mount ring 12 of the lens barrel 1 is screwed into the mount internal screw 17 of the camera mount 16 of the camera body 2 until the rear end face 27 of the mount ring 12 comes into contact with the front end face 31 of the camera body 2. The tube 1 is attached to the camera body 2. In this mounting operation, the projecting member 23 is in contact with the end portions of the guide grooves 18a and 18b of the lens barrel body 3, so that the lens barrel body 3 and the mount ring 12 are integrally continuous around the center line 6. Rotate to.

  Next, the lens barrel body 3 is rotated around the center line 6 with respect to the camera 2 until the focus ring operation knob or the like comes to a desired position.

  In this rotation, the lens barrel body 3 rotates using the protruding member 23 inserted into the guide grooves 18a and 18b as a guide. When the rotation of the desired amount is completed, the projecting member 23 is screwed deeply, the tip of the projecting member 23 is brought into contact with the bottom of the slip grooves 18a and 18b, and the mount ring 12 and the lens barrel body 3 are temporarily fixed by friction. Thereby, the rotational positioning of the lens barrel body 3 is completed.

  Next, the lock screw 26 of the lock ring 24 is rotated with respect to the lens barrel lock screw 11 to retract the lock ring 24 in the direction of the center line 6, and the rear end surface 29 is strongly against the front end surface 30 of the camera mount 16 of the camera body 2. As a result, the lens barrel body 3 is locked to the camera mount 16 by friction.

  As a result, the lens barrel main body 3 does not loosen even when vibration is applied to the mount portion, and the loosening prevention function is exhibited.

  As described above, according to the present invention, it is possible to reliably prevent the lens mount screw from loosening, to easily position the rotation position of the lens barrel during mounting, and to adversely affect the optical system of the camera. Thus, it is possible to obtain a lens mount mechanism that does not give the lens structure, does not complicate the structure of the mount portion, and does not increase the number of components.

Perspective view of lens mount mechanism Longitudinal sectional view of lens mount mechanism It is a figure which shows a guide groove, (a) is perspective explanatory drawing, (b) is front explanatory drawing, (c) is side explanatory drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens barrel 2 Camera 3 Lens barrel body 4 Lens 5 Lens holding frame 6 Center line 7 Lens barrel sliding outer peripheral surface 8 Lens barrel sliding small-diameter outer peripheral surface 9 Rear portion 10 Front portion 11 Lens barrel lock screw 12 Mount ring 13 Mount Screw 14 mount ring inner peripheral surface 15 sliding inner peripheral surface 16 camera mount 17 mount inner screw 18a guide groove 18b guide groove 19 rear portion 20 front portion 22 receiving hole 23 projecting member 24 lock ring 26 lock screw 27 rear end surface 29 rear end surface 30 Front end face 31 Front end face 51 Rotation adjusting means 52 Locking means 53 First screw part 54 Second screw part

Claims (6)

A mount ring connected to a lens barrel that holds a lens and screwed to the camera body; and a rotation adjusting means for moving the lens barrel to a desired rotation position around a center line with respect to the mount ring;
Locking means for locking relative rotation between the lens barrel and the camera body;
A lens mount mechanism characterized by comprising: The locking means is
A first threaded portion provided on the outer peripheral surface around the center line of the lens barrel;
A lock ring disposed on the outer peripheral side of the lens barrel in the radial direction and provided with a second screw portion threadably engageable with the first screw portion on an inner peripheral surface around a center line;
The second screw portion of the lock ring is screwed so as to be displaced in the center line direction with respect to the first screw portion of the lens barrel, and the end surface in the center line direction of the lock ring is pressed against the camera body. The lens mount mechanism according to claim 1, wherein the lens barrel is configured to lock relative rotation between the lens barrel and the camera body. The rotation adjusting means is
A guide groove provided on the outer peripheral surface around the center line of the lens barrel;
An accommodation hole provided in the mount ring so as to be disposed on the outer peripheral side around the center line of the guide groove, and drilled from the outside toward the guide groove;
A projecting member that is housed in the housing hole and is disposed so that a tip projects into the guide groove;
With
3. The lens mounting mechanism according to claim 1, wherein the lens barrel is rotated around a center line with respect to the mount ring by rotating the protruding member along the guide groove portion. A lens mount mechanism for mounting the lens barrel body to the camera body by screwing a mount ring attached to the lens barrel body into the camera body,
A lens barrel lock screw, a lens barrel sliding outer peripheral surface 7 and a guide groove with ends are provided around the center line on the outer peripheral surface of the lens barrel body,
The mount ring has a mount screw that can be screwed into the camera body around the center line on an inner peripheral surface or an outer peripheral surface, and can be slidably fitted to a sliding outer peripheral surface of the barrel main body on the inner peripheral surface. A projecting member having a sliding inner peripheral surface and reaching the guide groove of the lens barrel and guiding relative rotation along the guide groove around the center line of the lens barrel body and the mount ring;
A lock screw that engages with the lens barrel lock screw of the lens barrel is formed on the inner peripheral surface, and is screwed into the lens barrel lock screw to come into contact with the camera body in the center line direction outside the mount ring. A lock ring that is displaceable to a position and a position that is separated from the camera body, and that presses the camera body in the direction of the center line to lock relative rotation between the lens barrel body and the camera body. Lens mount mechanism. The guide groove is provided in two strips along one plane perpendicular to the center line, or one strip on each plane along two planes perpendicular to the center line spaced in the direction of the center line. The lens mount mechanism according to claim 4. A lens barrel comprising the lens mount mechanism according to any one of claims 1 to 5.

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