Mount structure

Abstract

To provide a mount structure that prevents the state of fixation of a lens barrel to a camera body from being loosened by vibration.SOLUTION: A mount structure comprises: a cylindrical lens barrel connection part having a thread groove formed in its inner peripheral surface; a mount base including a cylinder wall part formed between the lens barrel connection part and the mount base with a predetermined gap therebetween; and a mount lock in a cylindrical ring shape accommodated in two gaps and installed slidably in an optical axis direction of a lens. A first tapered surface is formed over the entire circumference on an outer peripheral side of an end on the camera body side of the mount lock. Screw holes for a pointed screw are formed at one or more positions of the cylinder wall part of the mount base. Pointed screws are screwed into the screw holes for a pointed screw to generate a force to press the first tapered surface of the mount lock in an inclined portion of a conical leading end of the pointed screw to move the tapered surface toward a lens barrel in the optical axis direction, and thereby press an end on the lens barrel side of the mount lock against an end of the lens barrel.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a mount structure in which the fixed state of a lens barrel with respect to a camera body does not loosen due to vibration or the like.

Background Art

[0002] Conventionally, photographing with a camera device has been performed in scenes such as product inspection and inspection in each process of a production line. An industrial camera (FA camera) used in such a scene is assumed to be used for a long period of time once it is installed. In such a site, external influences such as vibration act on the industrial camera, so that there is a possibility that the fixed state of the lens barrel with respect to the camera body and the fixed state of an operation unit such as a diaphragm may become loose.

[0003] As an example of adopting a structure for preventing loosening, for example, Patent Document 1 has already been proposed. In this Patent Document 1, a fixing member is screwed into a member used for an operation, and the tip of the fixing member is pushed into an inner member, so that the movement of the fixing member is restricted by the frictional force between the fixing member and the inner member, and as a result, a technique for fixing the member used for the operation is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the technology described in Patent Document 1 is screw-type fixing, loosening may occur in the screws due to vibrations or impacts from environmental factors at the camera installation location, etc., and there was a risk that the fixed state could not be maintained. Patent Document 1 is about fixing the adjustment state of the aperture, but even when fixing the camera body and the lens barrel by the same technology, there was a risk that the screws could become loose due to vibrations or impacts, etc.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a mount structure in which the fixed state of the lens barrel with respect to the camera body does not loosen due to vibrations or the like.

Means for Solving the Problems

[0007] The mount structure according to the present invention is a mount structure that screws and connects a lens barrel and a camera body, and at a connection portion of the camera body with the lens barrel, a cylindrical lens barrel connection portion having a screw groove formed on an inner peripheral surface, and a mount base fixed to the camera body and having a cylindrical wall portion formed with a predetermined gap between the lens barrel connection portion, and a cylindrical ring-shaped mount lock that is accommodated in the gap between the lens barrel connection portion and the mount base and is slidably installed in the optical axis direction of the lens barrel. A first tapered surface is formed over the entire circumference on the outer peripheral side of the end portion of the mount lock on the camera body side, and at least one position of the cylindrical wall portion of the mount base is formed with a gimlet screw hole through which a gimlet screw having a conical tip can be inserted by screwing. In a state where the lens barrel is connected to the camera body, by screwing and inserting the gimlet screw into the gimlet screw hole of the mount base, a force is generated to push the first tapered surface of the mount lock at the inclined portion of the conical tip of the gimlet screw and move the mount lock in the optical axis direction toward the lens barrel side, and it is characterized in that the end portion of the mount lock on the lens barrel side can be pressed against the end portion of the lens barrel.

[0008] Further, in the mount structure according to the present invention, a second tapered surface is formed over the entire circumference on the inner peripheral side of the lens barrel side end portion of the mount lock. When the diameter of the connected lens barrel is large, the upper surface portion of the cylindrical ring of the mount lock is pressed against the lens barrel, and when the diameter of the connected lens barrel is small, the second tapered surface of the mount lock is pressed against the lens barrel.

[0009] Further, in the mount structure according to the present invention, the mount base is connectable to the camera body in a plurality of patterns with different installation angles by a predetermined angle.

[0010] Further, in the mount structure according to the present invention, a long hole having a longitudinal length corresponding to the assumed sliding distance of the mount lock is formed at at least one position of the cylindrical wall portion of the mount base. A drop prevention screw is provided whose diameter is smaller than the width in the short direction of the long hole, and the other end side is accommodated inside the long hole while screwing the tip portion into the screw hole provided in the mount lock.

Effect of the Invention

[0011] According to the present invention, with the lens barrel connected to the camera body, by screwing and inserting a bayonet screw into the bayonet screw hole of the mount base, a force is generated to move the mount lock in the lens barrel side in the optical axis direction by pressing the first tapered surface of the mount lock at the inclined portion of the conical tip of the bayonet screw, and the end portion of the mount lock on the lens barrel side can be pressed against the end portion of the lens barrel. Since the rotation of the lens barrel with the end portion of the mount lock pressed is suppressed by the pressing pressure and the friction force generated therebetween, the lens barrel will not loosen even if vibration or impact is applied.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0013] Hereinafter, examples of embodiments of the present invention will be described with reference to the drawings. In addition, various components in the examples of the embodiments described below can be appropriately combined as long as there is no contradiction. Also, the description of the content described as an example of a certain embodiment may be omitted in other embodiments.

[0014] [First Embodiment] FIG. 1 is a perspective view showing an example of the configuration of a camera body 10 in a state where a lens barrel 20 corresponding to at least one of the embodiments of the present invention is connected. As shown in FIG. 1, in this example, a mount structure is described in which the lens barrel 20 does not loosen even if vibration or impact is applied by devising the location where the lens barrel 20 is connected to the camera body 10. The perspective view of FIG. 1 shows a state where the camera body 10 and the lens barrel 20 are connected by screwing, and it can be seen that the mount base 30 is located on the outer periphery of the connection location in the connected state.

[0015] FIG. 2 is a perspective view showing an example of the configuration of a camera body 10 corresponding to at least one of the embodiments of the present invention. This FIG. 2 shows the camera body 10 with the lens barrel 20 removed. As shown in FIG. 2, at the location where the lens barrel 20 is connected, a cylindrical lens barrel connection portion 11 having a thread groove formed on the inner peripheral surface is formed. The mount base 30 is a member fixed to the camera body 10 and includes a cylindrical wall portion 31 formed with a predetermined gap from the lens barrel connection portion 11. Also, a mount lock 40 is provided in the gap between the lens barrel connection portion 11 and the mount base 30. This mount lock 40 is a member in a substantially cylindrical ring shape and is installed so as to be slidable in the optical axis direction of the lens barrel 20.

[0016] FIG. 3 is a perspective view showing a partial cross-section of the internal configuration of the camera body 10 with the lens barrel 20 corresponding to at least one of the embodiments of the present invention connected thereto. This FIG. 3 shows the mount structure in which the lens barrel 20 is connected to the camera body 10. As shown in FIG. 3, a cylindrical connection screw portion 21 formed at the end of the lens barrel 20 is screwed by being screwed into a screw groove formed on the inner peripheral surface of the lens barrel connection portion 11 of the camera body 10. In this example, in a state where the lens barrel 20 is completely screwed into the camera body 10, the outer peripheral side end surface 22 of the lens barrel 20 is located near the mount lock 40. A bayonet screw hole 32 into which a bayonet screw 50 having a conical tip can be inserted and removed by screwing is formed through the cylindrical wall portion 31 of the mount base 30. The number of bayonet screw holes 32 formed is at least one or more, but it is preferable to form a plurality of them so that tightening can be performed uniformly from a plurality of directions. In this example, bayonet screw holes 32 are formed at four locations. On the outer peripheral side of the camera body side end of the mount lock 40, a first tapered surface 41 is formed over the entire circumference. The inclination angle of this first tapered surface 41 preferably coincides with the inclination angle of the cone at the tip of the bayonet screw 50. The end surface of the mount lock 40 on the lens barrel side is a contact end surface 42 that contacts the outer peripheral side end surface 22 of the lens barrel 20.

[0017] Next, with reference to FIGS. 4 and 5, the procedure for fixing the lens barrel 20 by the mount lock 40 will be described.

[0018] FIG. 4 is a cross-sectional view showing the internal configuration of the camera body 10 with the lens barrel 20 corresponding to at least one of the embodiments of the present invention connected thereto. This FIG. 4 shows a state where the lens barrel 20 is screwed into the camera body 10 but not fixed. When the lens barrel 20 is screwed into the camera body 10, although the abutting end face 42 of the mount lock 40 is positioned near the outer peripheral side end face 22 of the lens barrel 20, since the mount lock 40 is in a free state, it can be said that no force is acting on the lens barrel 20. Further, in FIG. 4, although the bayonet screw 50 is screwed and inserted into the bayonet screw hole 32 of the mount base 30, since it has only reached a shallow position of the bayonet screw hole 32 yet, the conical portion at the tip is in a state separated from the mount lock 40.

[0019] FIG. 5 is a cross-sectional view showing the internal configuration of the camera body 10 with the lens barrel 20 corresponding to at least one of the embodiments of the present invention connected thereto. This FIG. 5 shows a state in which the lens barrel 20 is screwed into the camera body 10 and fixed. When the bayonet screw 50 is further turned deeper by screwing from the state of FIG. 4, the inclined portion of the conical tip of the bayonet screw 50 hits the first tapered surface 41 of the mount lock 40. When the bayonet screw 50 is further inserted, the first tapered surface 41 pushed by the conical tip moves toward the lens barrel 20 side in the optical axis direction, and the contact end surface 42 of the mount lock 40 comes into contact with the outer peripheral side end surface 22 of the lens barrel 20. When the bayonet screw 50 is screwed to a position where it cannot be turned any further, the contact end surface 42 of the mount lock 40 is firmly pressed against the outer peripheral side end surface 22 of the lens barrel 20. By tightening a plurality of bayonet screws 50 with an equal torque, it becomes possible to firmly stretch the outer peripheral side end surface 22 of the lens barrel 20 with the contact end surface 42 of the mount lock 40. In this state, rotation is suppressed by the pressing pressure and the frictional force generated therebetween, and it becomes possible to further suppress the vibration of the lens barrel. Therefore, even if vibration or impact is applied, the lens barrel will not become loose. In addition, since the conventional fixing screw has a force applied only in the direction perpendicular to the optical axis, there is a risk of loosening due to vibration or the like. However, for the bayonet screw 50 in this example, the first tapered surface 41 is in contact with the inclined portion at the tip, and a force is applied in a state of being in contact with the first tapered surface 41 and the inclined portion. As a result, a force is applied not only in the direction perpendicular to the optical axis but also in the optical axis direction, and the risk of the bayonet screw 50 loosening due to vibration or the like can be significantly reduced.

[0020] FIG. 6 is a side view showing an example of the configuration of the camera body 10 with the lens barrel 20 corresponding to at least one of the embodiments of the present invention connected thereto. As shown in FIG. 6, a long hole 33 is formed in the mount base 30 of this example at a position different from the position where the bayonet screw hole 32 is formed, and a retaining screw 60 screwed to the mount lock 40 can be seen through the long hole 33.

[0021] FIG. 7 is a cross-sectional view showing the internal configuration of the camera body 10 with the lens barrel 20 connected corresponding to at least one of the embodiments of the present invention. As shown in FIG. 7, a thread groove is cut at the tip of the anti-drop screw 60, and it can be screwed into the screw hole 43 of the mount lock 40. The length of the long hole 33 in the longitudinal direction of the mount base 30 is formed to match the sliding distance required for the mount lock 40. Further, the width of the long hole 33 in the short direction is formed to have a gap that does not interfere with the anti-drop screw 60. By screwing the tip of the anti-drop screw 60 into the screw hole 43 provided in the mount lock 40 and allowing the other end side of the anti-drop screw 60 to be accommodated inside the long hole 33, while realizing free sliding movement of the mount lock 40, and by causing the other end side of the anti-drop screw 60 to be caught by the long hole 33, it becomes possible to prevent the mount lock 40 from falling off when the lens barrel 20 is removed. Note that the installation positions of the long hole 33 and the anti-drop screw 60 need to be at least one or more positions, but it is preferable to provide them at a plurality of locations because the posture state of the mount lock 40 is more stable than when provided at only one location.

[0022] FIG. 8 is an explanatory diagram showing the connection state of the mount base 20 to the camera body 10 corresponding to at least one of the embodiments of the present invention. In this example, the mount base 20 is fixed to the camera body 10 at eight locations with fixing screws 34. However, as shown in FIG. 8, when fixing at eight locations, it is possible to attach the mount base 20 even when the attachment angle is changed by 45 degrees. Not limited to this example, by making the mount base 20 connectable to the camera body 10 in a plurality of patterns with different installation angles by a predetermined angle, it becomes possible to set the tightening position of the bayonet screw 50 to a position desired by the user. In an operation of changing only the lens barrel 20 at the location where the camera body 10 is installed, depending on the situation of the installation location of the camera body 10, there may be an angle at which it is difficult to perform the tightening operation of the bayonet screw 50. In such a case, if the attachment angle of the mount base 20 can be changed, the user can adjust the attachment angle of the mount base 20 so that the screw hole 32 for the bayonet screw faces a position where the tightening operation is possible.

[0023] As described above, according to the mount structure of this example, with the lens barrel 20 connected to the camera body 10, by screwing and inserting the bayonet screw 50 into the screw hole 32 for the bayonet screw of the mount base 30, a force is generated to push the first tapered surface 41 of the mount lock in the lens barrel side in the optical axis direction with respect to the mount lock 40 at the inclined portion of the conical tip of the bayonet screw 50, and it becomes possible to press the end portion on the lens barrel side of the mount lock 40 against the outer peripheral end portion of the lens barrel 20. Since the rotation of the lens barrel 20 against which the end portion of the mount lock 40 is pressed is suppressed by the pressing pressure and the frictional force generated therebetween, loosening of the lens barrel does not occur even when vibration or impact is applied.

[0024] [Second Embodiment] FIG. 9 is a perspective view showing an example of the configuration of the camera body 10 with the lens barrel 20B corresponding to at least one of the embodiments of the present invention connected thereto. This second embodiment has the same configuration as the first embodiment except that the lens barrel to be connected is different, and the parts denoted by the same reference numerals function in the same manner as in the first embodiment, so redundant explanations are omitted. The lens barrel 20B shown in FIG. 9 has a smaller diameter than the lens barrel 20 in the first embodiment.

[0025] FIG. 10 is a perspective view showing a partial cross-section of the internal configuration of the camera body 10 with the lens barrel 20B corresponding to at least one of the embodiments of the present invention connected thereto. Further, FIG. 11 is a cross-sectional view showing the internal configuration of the camera body 10 with the lens barrel 20B corresponding to at least one of the embodiments of the present invention connected thereto. As shown in FIGS. 10 and 11, when the cylindrical connection screw portion 21 formed at the end of the lens barrel 20B is screwed into the screw groove formed on the inner peripheral surface of the lens barrel connection portion 11 of the camera body 10, the outer peripheral side end of the lens barrel 20B having a larger diameter than the diameter of the lens barrel connection portion 11 is connected in a state of protruding from the outer peripheral surface of the lens barrel connection portion 11. In this example, a tapered surface is formed over the entire circumference at the outer peripheral side end of the lens barrel 20B. Further, a second tapered surface 43 is formed over the entire circumference on the inner peripheral side of the lens barrel side end of the mount lock 40. It is preferable that the tapered surface at the outer peripheral side end of the lens barrel 20B and the second tapered surface 43 of the mount lock 40 have the same inclination angle.

[0026] When tightening the bayonet screw 50 with such a configuration, the first tapered surface 41 pushed by the conical tip moves toward the lens barrel 20B side in the optical axis direction, and the second tapered surface 43 of the mount lock 40 abuts against the tapered surface at the outer peripheral side end of the lens barrel 20B. Further, when the bayonet screw 50 is screwed to a position where it cannot be turned any further, the second tapered surface 43 of the mount lock 40 is firmly pressed against the tapered surface at the outer peripheral side end of the lens barrel 20B. In this state, rotation is suppressed by the pressing pressure and the frictional force generated therebetween, so that the lens barrel 20B will not become loose even if vibration or impact is applied.

[0027] In this way, by forming the second tapered surface 43 on the mount lock 40, when a lens barrel 20 with a large diameter as in the first embodiment is connected, the contact end surface 42 of the mount lock 40 is pressed against the outer peripheral side end surface 22 of the lens barrel 20 to firmly fix it. When a lens barrel 20B with a small diameter as in the second embodiment is connected, the second tapered surface 43 of the mount lock 40 is pressed against the tapered surface at the outer peripheral side end of the lens barrel 20 to firmly fix it. That is, since it is possible to selectively use two types of fixing means according to the type of the connected lens barrel, it is possible to provide a mount structure that can accommodate a plurality of lens barrels.

[0028] Although not described in the first and second embodiments, by adjusting settings such as the thickness of the mount lock 40, the length of the first tapered surface 41, the slidable distance of the mount lock 40 (which is also affected by the height of the cylindrical wall portion 31 of the mount base 30), the contact start position between the conical tip of the bayonet screw 50 and the first tapered surface 41, and the insertable depth of the bayonet screw 50, it is possible to set the distance by which the mount lock 40 can be moved by tightening the bayonet screw 50. Further, by adjusting the ratio of the area of the contact end surface 42 and the second tapered surface 43 of the mount lock 40, it is possible to set how to press and fix the connected lens barrel. By such adjustment, it is possible to provide a mount structure that can accommodate a plurality of types of lens barrels.

Explanation of Symbols

[0029] 10 Camera body 11 Lens barrel connection part 20, 20B Lens barrel 21 Connecting screw part 22 Outer peripheral side end face 30 Mount base 31 Cylindrical wall part 32 Screwdriver bit screw hole 33 Long hole 34 Fixing screw 40 Mount lock 41 First tapered surface 42 Contact end face 43 Second tapered surface 50 Screwdriver bit 60 Anti-drop screw

Claims

1. A mount structure for screwing and connecting a lens barrel and a camera body, at a connection location of the camera body with the lens barrel, a cylindrical lens barrel connection portion having a thread groove formed on an inner peripheral surface, and a mount base fixed to the camera body and having a cylindrical wall portion formed with a predetermined gap from the lens barrel connection portion, a cylindrical ring-shaped mount lock accommodated in the gap between the lens barrel connection portion and the mount base and installed slidably in the optical axis direction of the lens barrel, and a first tapered surface is formed over the entire circumference on an outer peripheral side of an end portion of the mount lock on the camera body side, at at least one position of the cylindrical wall portion of the mount base, a screw hole for a bayonet screw having a tip formed in a conical shape is formed to be penetrated so that the bayonet screw can be screwed in and out, in a state where the lens barrel is connected to the camera body, by screwing and inserting the bayonet screw into the screw hole for the bayonet screw of the mount base, a force is generated to push the first tapered surface of the mount lock at an inclined portion of the conical tip of the bayonet screw and move the mount lock in the optical axis direction toward the lens barrel side, so that an end portion of the mount lock on the lens barrel side can be pressed against an end portion of the lens barrel Mount structure.

2. A second tapered surface is formed over the entire circumference on an inner peripheral side of an end portion of the mount lock on the lens barrel side, when the diameter of the connected lens barrel is large, the upper surface portion of the cylindrical ring of the mount lock is pressed against the lens barrel, when the diameter of the connected lens barrel is small, the second tapered surface of the mount lock is pressed against the lens barrel The mount structure according to claim 1.

3. The mount base can be connected to the camera body in a plurality of patterns with different installation angles by a predetermined angle The mount structure according to claim 1.

4. at at least one position of the cylindrical wall portion of the mount base, a long hole having a longitudinal length corresponding to an assumed slide movement distance of the mount lock is formed, a diameter is smaller than a width in the short direction of the long hole, and a retaining screw is provided with a tip portion screwed into a screw hole provided in the mount lock while the other end side is accommodated inside the long hole The mount structure according to claim 1.

Images