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 the 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 the transmission of shutter shock vibration generated when a shutter mechanism in a camera body is driven to the substrate. Patent Document 2 discloses a lens barrel that presses and holds a substrate toward the 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 cutout portions for fitting the elastic members are required. However, electrical wiring cannot be installed in the holes, cutout portions, 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. S

[0006] The present invention aims to provide a lens barrel that is space-efficient and can suppress the transmission of vibrations to the substrate. [Means for solving the problem]

[0007] As one aspect of the present invention, the lens barrel comprises a fixed cylinder to which a mount including electrical contacts is attached, a first substrate on which electrical components are mounted, and a second substrate connected to the first substrate and the electrical contacts. A first elastic member that fixes the first substrate to the fixing cylinder, Displaced between the fixed cylinder and the first substrate Second It has an elastic member, When viewed from the direction of the optical axis, At least a portion of the second substrate is the It is overlapping with circuit board 1. The first elastic member does not overlap with the second substrate, and the second elastic member overlaps with the second substrate. The first substrate is subjected to force from the folded portion of the second substrate in the optical axis direction. Second It is characterized by being biased against an elastic member. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a lens barrel that is space-efficient and can suppress the transmission of vibrations to the substrate. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of a lens barrel according to an embodiment of the present invention. [Figure 2] This diagram shows the main components of a lens barrel. [Figure 3] This is an exploded perspective view of the main components of the lens barrel. [Figure 4] This is a cross-sectional view of the main components of the lens barrel. [Figure 5] This is a magnified view of a portion of Figure 4. [Figure 6] This is a side view of the main components of the lens barrel. [Figure 7] This is a view of an electrical component mounting board from the imaging side. [Figure 8] This is an explanatory diagram of the folded portion of a flexible circuit board. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. In each drawing, the same reference numeral is used for identical components, and redundant descriptions are omitted.

[0011] Figure 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 can be detachably attached to a camera body (not shown) such as an SLR camera, mirrorless camera, or film camera.

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

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

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

[0015] A plurality of constriction portions 21 are provided on the elastic members 2. The constriction 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 portion 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 members 2 and is fixed to the fixed cylinder 3.

[0016] The mount 4 is attached to the fixed cylinder 3 and compressively sandwiches (presses) the elastic members 2. Therefore, the constriction portions 21 of the elastic members 2 serve as a retaining means, and the electrical component mounting substrate 1 is held by the elastic members 2 in a positioned state in the optical axis direction. Thereby, external vibrations such as shutter shock vibrations generated when the shutter mechanism in the camera body is driven are absorbed by the elastic members 2 and are 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 an urabuta 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] Although the contact pins 51 on the contact terminal block 5 and the electrical component mounting board 1 do not overlap when viewed from the optical axis direction, the distance between them in the direction perpendicular to the optical axis is very narrow. Furthermore, solder is added around the contact pins 51 when soldering them to connect them to the flexible substrate 6, so the distance becomes even narrower by the volume of the added solder. Therefore, there is a risk that the contact pins 51 and the solder around them may come into contact with the electrical component mounting board 1. To avoid such contact, it is necessary to separate the electrical component mounting board 1 and the contact terminal block 5 sufficiently in the optical axis direction, but this increases the overall length of the lens barrel 100 in the optical axis direction.

[0019] Therefore, in this embodiment, in order to avoid such contact, a small-diameter portion 13 is provided on a part of the outer circumference of the electrical component mounting board 1, which has a smaller diameter than other parts. The small-diameter portion 13 occupies an area of ​​about one-quarter of the electrical component mounting board 1 in the circumferential direction. Since the contact pin 51 fits into the small-diameter portion 13, the contact terminal block 5 and the flexible board 6 overlap with the electrical component mounting board 1 in the optical axis direction. Thus, the overall length of the lens barrel 100 can be shortened while avoiding contact between the electrical component mounting board 1 and the contact terminal block 5.

[0020] In this embodiment, the electrical component mounting board 1 and the contact terminal block 5 are connected by inserting the flexible board 6 into the connector (connection part between the electrical component mounting board 1 and the flexible board 6) 14 installed on the electrical component mounting board 1. By using the connector 14, it is possible to miniaturize the electrical component mounting board 1, improve assembly workability, and reduce assembly costs. The electrical component mounting board 1 has a narrow section 15 with a narrow radial width due to the provision of a small diameter section 13. It is difficult to install the connector 14 in the narrow section 15 because the radial width is insufficient compared to the radial width of the connector 14, or even if the width is sufficient, it is not possible to provide a wiring pattern for the connector 14. Therefore, in this embodiment, as shown in Figure 3, the connector 14 is installed adjacent to the small diameter section 13 in an area with a sufficiently wide radial width.

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

[0022] Furthermore, because the narrow section 15 has a narrow radial width, it is difficult to provide notches 11 and 12, which are used to fix elastic members 2, in the narrow section 15. While it is possible to provide notches in the region connected by bridging to the outer circumference of the small-diameter section 13, this would cause the electrical component mounting substrate 1 to widen on the outer diameter side, leading to an increase in the size of the lens barrel 100.

[0023] The flexible substrate 6 has a folded portion 61 formed thereon, with its first end connected to the electrical component mounting board 1 and its second end connected to the contact terminal block 5. In this embodiment, the first end is inserted into the connector 14. The flexible substrate 6 is also positioned so as to overlap with the electrical component mounting board 1 when viewed from the direction of the optical axis. In this embodiment, the folded portion 61 is formed in a U-shape, but it may be bent. The straight line connecting the center of the folded portion 61 and the optical axis center is positioned within an angle range (first angle range) 17 of approximately ±60 degrees, based on the straight line connecting the connector 14 and the optical axis center shown in Figure 7. Note that the approximately ±60 degrees includes cases where it is exactly ±60 degrees and cases where there is an error of a few degrees but it is considered to be 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 placed in the region that overlaps with the flexible substrate 6 when viewed from the optical axis direction, or in the region adjacent to that region, there is a risk of disconnecting the flexible substrate 6 or worsening the ease of assembly. Accordingly, in this embodiment, the elastic member 2 cannot be placed within the unplaceable angle range 16 of the electrical component mounting substrate 1 shown in Figure 7. The unplaceable angle range 16 includes the region where the small diameter portion 13 and the flexible substrate 6 overlap when viewed from the optical axis direction, and the region adjacent to that region, and is an angle range of approximately 140 degrees. Note that "approximately 140 degrees" includes cases where it is exactly 140 degrees and cases where there is a difference of a few degrees but it is substantially 140 degrees. It is desirable that the electrical component mounting substrate 1 be held and fixed at three locations divided into approximately 120-degree equal parts. However, in this embodiment, since the elastic member 2 cannot be placed within the unplaceable angle range 16, the electrical component mounting substrate 1 cannot be held by the three elastic members 2, making it difficult to stably hold the electrical component mounting substrate 1. If the three elastic members 2 are placed within an angle range of approximately 220 degrees outside the unplaceable angle range 16, the arrangement will be uneven. Even if the elastic members 2 could be placed at both ends of the unplaceable angle range 16, there is still an angle range of 140 degrees where the elastic members 2 cannot be held, causing the electrical component mounting board 1 to rotate and vibrate around the straight line connecting the elastic members 2 at both ends as an axis. As a result, the electrical component mounting board 1 vibrates due to external vibrations, and the image blur correction performance deteriorates.

[0025] Furthermore, since the contact terminal block 5 and connector 14 are general-purpose parts and their size is basically constant, if the electrical component mounting board 1 is miniaturized in order to miniaturize the lens barrel 100, the range of angles where placement is not possible 16 will become larger. The larger the range of angles where placement is not possible 16 becomes, the less stable the electrical component mounting board 1 can be held, and the less effective it becomes at suppressing external vibrations.

[0026] Therefore, in this embodiment, an elastic member (second elastic member) 7 is placed between the fixed cylinder 3 and the electrical component mounting substrate 1 in the optical axis direction. The elastic member 7 is positioned within an angular range 17, is made of an elastic material 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 recess 32 of the fixed cylinder 3. The spherical shape 72 protrudes from the fixed cylinder 3 in the optical axis direction. The electrical component mounting substrate 1 is in contact with the tip of the spherical shape 72 on the side facing 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) acts on the flexible substrate 6, attempting to open the folded portion 61 shown in Figure 3. The force F acts toward the side of the fixed cylinder 3 (object side) in the optical axis direction, as indicated by the arrow direction in Figure 3.

[0028] The electrical component mounting substrate 1 is biased against the elastic member 7 by a force F and pressed against the tip of the spherical shape 72. Since the elastic member 7 is made of an elastically deformable material with surface friction, such as silicone rubber, the electrical component mounting substrate 1 and the spherical shape 72 come into contact with an increased contact area, and a predetermined frictional force acts. As a result, the elastic member 7 functions as a member that holds the third electrical component mounting substrate 1. In other words, the electrical component mounting substrate 1 is supported at three points by the two elastic members 2 and the elastic member 7, and is held stably. Therefore, the transmission of external vibrations to the vibration detection means can be suppressed.

[0029] In this embodiment, the flexible substrate 6 supplies power to drive components inside the lens barrel 100 (for example, a zoom lens, a focus lens, an image stabilization lens, or an aperture unit). For this reason, the flexible substrate 6 is provided with multiple patterns, for example, with a width of 0.3 mm or more. When multiple wide patterns are provided, the force F increases, and the electrical component mounting substrate 1 can be sufficiently biased.

[0030] The folded portion 61 will now be described with reference to Figure 8. Figure 8 is an explanatory diagram of the folded portion 61, showing a cross-section of the folded portion 61 and the surrounding components. In Figure 8(a), the folded portion 61 is formed between the contact terminal block 5 and the electrical component mounting board 1. Therefore, the folded portion 61 overlaps with the contact terminal block 5 when viewed from the optical axis direction. In Figure 8(b), the folded portion 61 is formed between the mount 4 and the electrical component mounting board 1. Therefore, the folded portion 61 overlaps with the mount 4 when viewed from the optical axis direction, but does not overlap with the contact terminal block 5. In Figure 8(c), the folded portion 61 overlaps with the mount 4 when viewed from the optical axis direction, but does not overlap with the electrical component mounting board 1. In all cases from Figure 8(a) to Figure 8(c), the electrical component mounting board 1 is biased towards the fixed cylinder 3 by a force F from the folded portion 61. Therefore, the flexible circuit board 6 only needs to be connected to the electrical component mounting board 1 and the contact terminal block 5 with a folded portion 61 formed therein that can bias the electrical component mounting board 1 toward the fixing cylinder 3.

[0031] In this embodiment, the flexible substrate 6 is connected to the electrical component mounting board 1 on the side opposite to the side of the fixing cylinder 3 (the side facing the mount 4 and contact terminal block 5), but the present invention is not limited to this. The flexible substrate 6 may also be connected to the electrical component mounting board 1 on the side of the fixing cylinder 3, as shown in Figure 8(d).

[0032] As described above, the configuration of this embodiment provides a lens barrel 100 that is space-efficient and can suppress the transmission of vibrations to the vibration detection means.

[0033] The following description will explain application examples, modifications, and optimal examples for obtaining greater effectiveness of this embodiment.

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

[0035] Furthermore, in this embodiment, the folded portion 61 of the flexible substrate 6 has the greatest effect in biasing the electrical component mounting substrate 1, so the positions (phases) of the connector 14 and the folded portion 61 around the optical axis are aligned, 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, the positions (phases) of the connector 14 and the folded portion 61 around the optical axis do not have to be aligned.

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

[0037] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various combinations, modifications, and changes are possible within the scope of its gist. [Explanation of symbols]

[0038] 1. Electrical component mounting board (first board) 2. Elastic member (first elastic member) 3 Fixed tube 4 Mounts 5. Contact terminal block (electrical contacts) 6. Flexible circuit board (second circuit board) 7. Elastic member (second elastic member)

Claims

1. A fixed cylinder to which a mount including electrical contacts is attached, A first circuit board with electrical components mounted on it, The first substrate and the second substrate connected to the electrical contacts, A first elastic member for fixing the first substrate to the fixing cylinder, It comprises a second elastic member disposed between the fixed cylinder and the first substrate, When viewed from the direction of the optical axis, at least a portion of the second substrate overlaps with the first substrate, the first elastic member does not overlap with the second substrate, and the second elastic member overlaps with the second substrate. The lens barrel is characterized in that the first substrate is biased in the optical axis direction relative to the second elastic member by a force from the folded portion of the second substrate.

2. The lens barrel according to claim 1, characterized in that the second substrate is connected to the first substrate on the side opposite to the side of the fixed cylinder.

3. The lens barrel according to claim 1, characterized in that the second substrate is connected to the first substrate on the side of the fixed cylinder.

4. The lens barrel according to any one of claims 1 to 3, characterized in that, when viewed from the optical axis direction, the second elastic member is positioned within an angular range of ±60 degrees with respect to the straight line connecting the connection portion between the first substrate and the second substrate and the optical axis.

5. A fixed cylinder to which a mount including electrical contacts is attached, A first circuit board with electrical components mounted on it, The first substrate and the second substrate connected to the electrical contacts, It has 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 direction of the optical axis, The first substrate is biased in the optical axis direction relative to the elastic member by the force from the folded portion of the second substrate. A lens barrel characterized in that the second substrate is connected to the first substrate on the side of the fixed cylinder.

6. The lens barrel according to any one of claims 1 to 5, characterized in that at least a portion of the folded portion overlaps with the mount when viewed from the optical axis direction.

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

8. The lens barrel according to any one of claims 1 to 7, characterized in that, when viewed from the direction of the optical axis, the 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 the straight line connecting the connection portion between the first substrate and the second substrate and the optical axis.

9. The lens barrel according to any one of claims 1 to 8, characterized in that it can be attached to and detached from the camera body via the aforementioned mount.

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