Lens barrel

Abstract

To provide a lens barrel having excellent space efficiency and capable of suppressing transmission of vibration to a substrate.SOLUTION: A lens barrel has: a fixed cylinder to which a mount including an electrical contact is attached; a first board on which an electrical component is mounted; a second board connected to the first board and the electrical contact; and an elastic member arranged between the fixed cylinder and the first board. At least a part of the second board overlaps with the first board when viewed from an optical axis direction. The first board is biased against the elastic member in the optical axis direction by force from a folded part of the second board.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lens barrel.

Background Art

[0002] Conventionally, in a lens barrel of an interchangeable lens system, a substrate on which electrical components are mounted is positioned and fixed near a mount, which is an attachment portion to a camera body. Patent Document 1 discloses a lens barrel that holds a substrate with an elastic member in order to suppress transmission of shutter shock vibration generated when a shutter mechanism in a camera body is driven. Patent Document 2 discloses a lens barrel that presses and holds a substrate toward a mount side with a biasing rubber installed between a fixing portion and the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the lens barrel of Patent Document 1, since the substrate is held by at least three elastic members, three holes or notches for fitting the elastic members are required. However, electrical wiring cannot be installed in the holes, notches, and their peripheral portions, and electrical components cannot be mounted either. Therefore, it cannot be said that the space efficiency is good, and it is difficult to further miniaturize the lens barrel.

[0005] Also, in the lens barrel of Patent Document 2, vibration is directly transmitted to the substrate through the mount.

[0006] An object of the present invention is to provide a lens barrel that has good space efficiency and can suppress transmission of vibration to a substrate.

Means for Solving the Problems

[0007] A lens barrel according to one aspect of the present invention includes a fixed barrel to which a mount including an electrical contact is attached, a first substrate on which electrical components are mounted, a second substrate connected to the first substrate and the electrical contact, and an elastic member disposed between the fixed barrel and the first substrate. At least a part of the second substrate overlaps the first substrate when viewed from the optical axis direction, and the first substrate is biased against the elastic member in the optical axis direction by a force from a folded-back portion of the second substrate.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a lens barrel that has good space efficiency and can suppress transmission of vibration to a substrate.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

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Figure 7

Figure 8

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] FIG. 1 is a cross-sectional view of a lens barrel (interchangeable lens) 100 according to an embodiment of the present invention. The lens barrel 100 is detachably attached to a camera body (not shown) such as a single-lens reflex camera, a mirrorless camera, or a film camera.

[0012] The lens barrel 100 has a plurality of lens groups. The anti-shake lens group L moves in a direction including a component in a direction perpendicular to the optical axis X of the lens barrel 100 during image blur correction. The lens barrel 100 may have configurations such as a focus mechanism, a zoom mechanism, or an electric aperture mechanism. The electric component mounting substrate (first substrate) 1 is an annular printed circuit board on which a control circuit and shake detection means for detecting blur are mounted, and controls various actuators and the electromagnetic aperture 113. Specifically, the shake detection means is a gyro sensor or an acceleration sensor. Note that the shape of the electric component mounting substrate 1 may be a C-shaped shape that is connected at least 180° or more (for example, about 240°) in the circumferential direction.

[0013] FIG. 2 is a diagram showing the main components of the lens barrel 100. FIG. 2(a) is a perspective view of the main components, and FIG. 2(b) is a view of the main components as seen from the imaging surface side. FIG. 3 is an exploded perspective view of the main components. FIG. 4 is a cross-sectional view of the main components of the lens barrel 100. FIG. 5 is a partially enlarged view of FIG. 4, showing the peripheral portion of the elastic member 2. FIG. 6 is a side view of the main components of the lens barrel 100 as seen from the side of the contact terminal block 5. FIG. 7 is a view of the electric component mounting substrate 1 as seen from the imaging surface side.

[0014] The electric component mounting substrate 1 is disposed between the fixed barrel 3 and the mount 4 in the optical axis direction of the lens barrel 100. Cutout portions 11 and 12 are provided on the outer periphery of the electric component mounting substrate 1. The elastic member (first elastic member) 2 is inserted into the cutout portions 11 and 12 while being elastically deformed. The elastic member 2 is made of a material that is easily elastically deformed, such as silicone rubber.

[0015] The elastic member 2 is provided with a plurality of constricted portions 21. The constricted portions 21 are configured to sandwich the electrical component mounting substrate 1. Further, a hole portion 22 is provided at the center of the elastic member 2. A protrusion 31 provided on the fixed cylinder 3 is inserted into the hole portion 22. Therefore, the electrical component mounting substrate 1 is positioned and held in the direction orthogonal to the optical axis by the elastic member 2 and fixed to the fixed cylinder 3.

[0016] The mount 4 is attached to the fixed cylinder 3 and compressively clamps (presses) the elastic member 2. Therefore, the constricted portions 21 of the elastic member 2 serve as a retaining means, and the electrical component mounting substrate 1 is held by the elastic member 2 in a positioned state in the optical axis direction. As a result, external vibrations such as shutter shock vibrations generated when the shutter mechanism in the camera body is driven are absorbed by the elastic member 2 and not transmitted to the shake detection means mounted on the electrical component mounting substrate 1. Generally, the mount of an interchangeable lens has a function of connecting the interchangeable lens and the camera body, but the mount 4 of the present embodiment does not necessarily have such a function. For example, it may be a separate component such as a back cover for preventing ghosts, flares, etc. caused by harmful light reflected by components near the mount that are fixed to a general mount.

[0017] The contact terminal block (electrical contact) 5 is immovably fixed to the mount 4 by screws, adhesion, etc., makes electrical connection with the electrical component mounting substrate 1 via the flexible substrate (second substrate) 6, and performs communication with the camera body and power supply.

[0018] The contact pin 51 provided on the contact terminal block 5 and the electrical component mounting substrate 1 do not overlap when viewed from the optical axis direction, but the distance between them in the direction orthogonal to the optical axis is very narrow. Also, since solder is applied around the contact pin 51 to electrically connect the contact pin 51 to the flexible substrate 6, the above-mentioned distance becomes narrower by the volume of the applied solder. Therefore, there is a risk that the contact pin 51 and the solder around the contact pin 51 may come into contact with the electrical component mounting substrate 1. To avoid such contact, it is necessary to sufficiently separate the electrical component mounting substrate 1 and the contact terminal block 5 in the optical axis direction, but the overall length of the lens barrel 100 increases in the optical axis direction.

[0019] Therefore, in the present embodiment, in order to avoid such contact, a small-diameter portion 13 having a diameter smaller than that of other portions is provided on a part of the outer periphery of the electrical component mounting substrate 1. The small-diameter portion 13 occupies a range of about one-fourth of the electrical component mounting substrate 1 in the circumferential direction of the electrical component mounting substrate 1. Since the contact pin 51 enters the small-diameter portion 13, the contact terminal block 5 and the flexible substrate 6 overlap the electrical component mounting substrate 1 in the optical axis direction. Therefore, it is possible to shorten the overall length of the lens barrel 100 while avoiding contact between the electrical component mounting substrate 1 and the contact terminal block 5.

[0020] In the present embodiment, the electrical component mounting substrate 1 and the contact terminal block 5 are connected by inserting the flexible substrate 6 into a connector (connection portion between the electrical component mounting substrate 1 and the flexible substrate 6) 14 provided on the electrical component mounting substrate 1. By using the connector 14, it is possible to miniaturize the electrical component mounting substrate 1, improve the assembly workability, and reduce the assembly cost. On the electrical component mounting substrate 1, a narrow-width portion 15 having a narrow width in the radial direction is formed by providing the small-diameter portion 13. It is difficult to install the connector 14 in the narrow-width portion 15 because the width in the radial direction is insufficient compared to the width in the radial direction of the connector 14, or even if the width is sufficient, a wiring pattern for the connector 14 cannot be provided. Therefore, in the present embodiment, as shown in FIG. 3, the connector 14 is installed in a region adjacent to the small-diameter portion 13 and having a sufficiently wide width in the radial direction.

[0021] Note that when connecting the flexible substrate 6 to the electrical component mounting substrate 1, it is not necessary to use the connector 14. For example, the flexible substrate 6 may be connected to the electrical component mounting substrate 1 by soldering it to the land portion provided on the electrical component mounting substrate 1.

[0022] Also, since the narrow portion 15 has a narrow width in the radial direction, it is difficult to provide a notch for fixing the elastic members 2 such as the notches 11 and 12 in the narrow portion 15. Although it is possible to provide a notch in the region bridged and connected to the outer peripheral side of the small-diameter portion 13, the electrical component mounting substrate 1 extends to the outer diameter side, leading to an increase in the size of the lens barrel 100.

[0023] The flexible substrate 6 is connected to the electrical component mounting substrate 1 at the first end and to the contact terminal block 5 at the second end with the folded-back portion 61 formed. In this embodiment, the first end is inserted into the connector 14. Also, the flexible substrate 6 is arranged so as to overlap the electrical component mounting substrate 1 when viewed from the optical axis direction. The folded-back portion 61 is formed in a U shape in this embodiment, but it may be bent. Also, the straight line connecting the center of the folded-back portion 61 and the optical axis center is arranged within an angular range (first angular range) 17 of approximately ±60 degrees with respect to the straight line connecting the connector 14 shown in FIG. 7 and the optical axis center. Note that the approximately ±60 degrees includes cases where it is exactly ±60 degrees and cases with an error of about several degrees but is regarded as substantially ±60 degrees.

[0024] The elastic member 2 is longer than the electrical component mounting substrate 1 in the optical axis direction. Therefore, if the elastic member 2 is arranged in the region overlapping the flexible substrate 6 and the region adjacent to the region when viewed from the optical axis direction, there is a risk of disconnecting the flexible substrate 6 or deteriorating the assembly workability. Therefore, in the present embodiment, the elastic member 2 cannot be arranged within the non-arrangeable angle range 16 of the electrical component mounting substrate 1 shown in FIG. 7. The non-arrangeable angle range 16 includes the region where the small-diameter portion 13 and the flexible substrate 6 overlap and the region adjacent to the region when viewed from the optical axis direction, and is an angular range of approximately 140 degrees. Note that the approximately 140 degrees includes cases where it is exactly 140 degrees and cases where there is a difference of several degrees but it is substantially 140 degrees. The electrical component mounting substrate 1 is preferably held and fixed at approximately three equally divided positions of 120 degrees. However, in the present embodiment, since the elastic member 2 cannot be arranged within the non-arrangeable angle range 16, the electrical component mounting substrate 1 cannot be held by the three elastic members 2, and it is difficult to stably hold the electrical component mounting substrate 1. When the three elastic members 2 are arranged within the approximately 220-degree angle range outside the non-arrangeable angle range 16, the arrangement becomes uneven. Even if the elastic members 2 could be arranged at both ends of the non-arrangeable angle range 16, there is still an angle range of 140 degrees where the elastic members 2 cannot be held, and the electrical component mounting substrate 1 rotates and vibrates about the straight line connecting the elastic members 2 at both ends. Therefore, the electrical component mounting substrate 1 vibrates due to external vibration, and the performance of image blur correction deteriorates.

[0025] Also, the contact terminal block 5 and the connector 14 are general-purpose components and their sizes are basically constant. Therefore, when attempting to miniaturize the electrical component mounting substrate 1 for miniaturization of the lens barrel 100, the non-arrangeable angle range 16 becomes larger. The larger the non-arrangeable angle range 16, the more difficult it is to stably hold the electrical component mounting substrate 1, and it becomes impossible to suppress external vibration.

[0026] Therefore, in this embodiment, an elastic member (second elastic member) 7 is disposed between the fixed cylinder 3 and the electric component mounting substrate 1 in the optical axis direction. The elastic member 7 is disposed within the angular range 17 and is formed of a material having elasticity such as silicone rubber, and is a component in which a cylindrical shape 71 and a spherical shape 72 are integrally formed. The elastic member 7 is positioned and fixed by inserting the cylindrical shape 71 into the concave portion 32 of the fixed cylinder 3. The spherical shape 72 protrudes from the fixed cylinder 3 in the optical axis direction. The electric component mounting substrate 1 is in contact with the tip of the spherical shape 72 on the side of the fixed cylinder 3.

[0027] Since the flexible substrate 6 is made of a flexible material such as polyimide, a force F (reaction force or restoring force) that attempts to open the folded portion 61 shown in FIG. 3 acts on the flexible substrate 6. The force F acts toward the side (object side) of the fixed cylinder 3 in the optical axis direction as shown by the arrow direction in FIG. 3.

[0028] The electric component mounting substrate 1 is biased against the elastic member 7 by the force F and pressed against the tip of the spherical shape 72. Since the elastic member 7 is formed of a material that can be elastically deformed and has surface friction such as silicone rubber, the electric component mounting substrate 1 and the spherical shape 72 are in contact with an increased contact area, and a predetermined frictional force acts. Thereby, the elastic member 7 functions as a member for holding the third electric component mounting substrate 1. That is, the electric component mounting substrate 1 is supported at three points by the two elastic members 2 and the elastic member 7 and is stably held. Therefore, transmission of external vibration to the shake detection means can be suppressed.

[0029] In this embodiment, the flexible substrate 6 supplies electric power for driving a member (for example, a zoom lens, a focus lens, an image stabilization lens, or a diaphragm unit) inside the lens barrel 100. Therefore, a plurality of patterns having a width of 0.3 mm or more, for example, are provided on the flexible substrate 6. When a plurality of patterns having a thick width are provided, the force F becomes large, and the electric component mounting substrate 1 can be sufficiently biased.

[0030] Hereinafter, with reference to FIG. 8, the folded portion 61 will be described. FIG. 8 is an explanatory diagram of the folded portion 61, showing a cross-section of the folded portion 61 and the surrounding members. In FIG. 8(a), the folded portion 61 is formed between the contact terminal block 5 and the electrical component mounting substrate 1. Therefore, the folded portion 61 overlaps the contact terminal block 5 when viewed from the optical axis direction. In FIG. 8(b), the folded portion 61 is formed between the mount 4 and the electrical component mounting substrate 1. Therefore, the folded portion 61 overlaps the mount 4 when viewed from the optical axis direction, but does not overlap the contact terminal block 5. In FIG. 8(c), the folded portion 61 overlaps the mount 4 when viewed from the optical axis direction, but does not overlap the electrical component mounting substrate 1. In any of the cases from FIG. 8(a) to FIG. 8(c), the electrical component mounting substrate 1 is biased toward the fixed cylinder 3 by the force F from the folded portion 61. Therefore, the flexible substrate 6 may be connected to the electrical component mounting substrate 1 and the contact terminal block 5 in a state where the folded portion 61 capable of biasing the electrical component mounting substrate 1 toward the fixed cylinder 3 is formed.

[0031] Note that in the present embodiment, the flexible substrate 6 is connected to the electrical component mounting substrate 1 on the surface opposite to the surface of the fixed cylinder 3 side of the electrical component mounting substrate 1 (the surface facing the mount 4 and the contact terminal block 5), but the present invention is not limited thereto. As shown in FIG. 8(d), the flexible substrate 6 may be connected to the electrical component mounting substrate 1 on the surface of the fixed cylinder 3 side of the electrical component mounting substrate 1.

[0032] As described above, according to the configuration of the present embodiment, it is possible to provide the lens barrel 100 with good space efficiency and capable of suppressing the transmission of vibration to the shake detection means.

[0033] In the following description, application examples, modification examples, and optimal examples for obtaining more effects of the present embodiment will be described.

[0034] In this embodiment, the connector 14 and the two elastic members 2 are arranged at intervals of approximately 120 degrees around the optical axis, but the present invention is not limited to this. The elastic member 2 may be arranged within an angular range of approximately 240 degrees (second angular range) outside the angular range 17. Note that the approximately 240 degrees includes cases where it is exactly 240 degrees and cases where there is an error of about several degrees but is substantially regarded as 240 degrees.

[0035] Further, in this embodiment, since the effect of the folded portion 61 of the flexible substrate 6 biasing the electrical component mounting substrate 1 is the greatest, the positions (phases) of the connector 14 and the folded portion 61 around the optical axis are made to coincide, but the present invention is not limited to this. As long as the electrical component mounting substrate 1 can be biased toward the fixed cylinder 3 side, the positions (phases) of the connector 14 and the folded portion 61 around the optical axis do not have to coincide.

[0036] Also, in this embodiment, the elastic member 7 is arranged in the non - arrangeable angular range 16 and is arranged so as to overlap the flexible substrate 6 when viewed from the optical axis direction. In order to further suppress the transmission of vibration to the vibration detection means, it is desirable that the elastic member 7 is aligned with the position of the folded portion 61 in terms of the position (phase) around the optical axis (overlaps the folded portion 61 when viewed from the optical axis direction).

[0037] As described above, the preferred embodiments of the present invention have been explained, but the present invention is not limited to these embodiments, and various combinations, modifications, and changes are possible within the scope of the gist thereof.

Explanation of Reference Numerals

[0038] 1 Electrical component mounting substrate (first substrate) 2 Elastic member (first elastic member) 3 Fixed cylinder 4 Mount 5 Contact terminal block (electrical contact) 6 Flexible substrate (second substrate) 7 Elastic member (second elastic member)

Claims

1. a fixed barrel having a mount including electrical contacts attached thereto; a first substrate on which electrical components are mounted; a second substrate connected to the first substrate and the electrical contacts; an elastic member disposed between the fixed cylinder and the first substrate; At least a portion of the second substrate overlaps with the first substrate when viewed from the optical axis direction; The lens barrel according to claim 1, wherein the first substrate is biased against the elastic member in the optical axis direction by a force from a folded portion of the second substrate.

2. The lens barrel according to claim 1 , wherein the second substrate is connected to the first substrate on a surface opposite to the fixed tube side.

3. The lens barrel according to claim 1 , wherein the second substrate is connected to the first substrate on a surface facing the fixed tube.

4. 4. The lens barrel according to claim 1, wherein the second substrate overlaps with the elastic member when viewed from the optical axis direction.

5. 5. The lens barrel according to claim 1, wherein at least a portion of the folded portion overlaps with the mount when viewed from the optical axis direction.

6. The lens barrel according to claim 5 , wherein at least a portion of the folded portion overlaps with the electrical contact when viewed in the optical axis direction.

7. 7. The lens barrel according to claim 1, wherein, when viewed from the optical axis direction, the elastic member is arranged within an angular range of ±60 degrees with respect to a straight line connecting the optical axis and a connection portion between the first substrate and the second substrate.

8. 8. The lens barrel according to claim 1, wherein, when viewed from the optical axis direction, a straight line connecting the center of the folded portion and the optical axis is located within an angular range of ±60 degrees with respect to a straight line connecting the connection portion between the first substrate and the second substrate and the optical axis.

9. 9. The lens barrel according to claim 1, which is detachable from a camera body via the mount.

Images