Collision reduction mechanism, lens barrel and imaging device

Abstract

To provide a collision reduction mechanism, a lens barrel, and an imaging device which can reduce collision sounds.SOLUTION: The collision reduction mechanism includes: a guide shaft (32A) fixed to a fixation frame (31A) and having a sleeve (33); a movable unit (34); and a brake top (36A) for generating a force which presses the guide shaft. When the movable unit (34) is in contact with the brake top (36A), one of the brake top (36A) and the sleeve (33) presses the guide shaft (32A).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a collision reduction mechanism, a lens barrel, and an imaging device. [Background technology]

[0002] Imaging devices such as digital still cameras and mirrorless single-lens cameras are provided with a mechanism that uses a voice coil motor to move a lens group along the optical axis. In such mechanisms, the voice coil motor does not generate a self-retaining force when the power is off. Therefore, if the lens barrel is shaken while the power is off, the weight of the lens group causes the movable group to move along the optical axis, colliding with a stopper located within the movable range and generating a collision noise. Furthermore, the impact force generated by the collision with the stopper could, in the worst case scenario, damage the lens barrel (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-243877 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-44166 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-169844 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional technologies leave room for further study to reduce impact noise while maintaining compactness. For example, the technologies described in Patent Documents 1 and 2 employ a configuration in which an elastic member deforms to reduce impact force and avoid the generation of impact noise. In such a configuration, the thickness and size of the elastic member must be adjusted, and space is required to accommodate the elastic member. Furthermore, the technology described in Patent Document 3 reduces impact noise by using frictional force generated by the magnetic attraction of the voice coil motor's magnet as resistance, but it is difficult to appropriately adjust the frictional force generated by the magnetic attraction.

[0005] An object of the present invention is to provide a collision reduction mechanism, a lens barrel, and an imaging device that can reduce collision noise while maintaining a small size. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a collision reduction mechanism according to one aspect of the present invention comprises a guide shaft having one end fixed by a fixed portion and extending in a first direction, a movable portion having a sleeve through which the guide shaft is inserted and movable in the first direction by the sleeve, and a brake piece that generates a force pressing against the guide shaft in a second direction intersecting the first direction, wherein the brake piece or the sleeve includes a pressing portion that advances toward the guide shaft in the second direction and presses against the guide shaft when the movable portion moves to the one end of the guide shaft and the movable portion or the fixed portion abuts against the brake piece. In order to solve the above problem, a lens barrel according to one aspect of the present invention has the above-described collision reduction mechanism. In order to solve the above problem, an imaging device according to one aspect of the present invention includes the above collision reduction mechanism. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to provide a small-sized collision reduction mechanism, a lens barrel, and an imaging device that can reduce collision noise. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a basic configuration of a collision reduction mechanism according to an embodiment. [Figure 2] 1 is a diagram schematically illustrating an example of a lens barrel and an imaging device according to an embodiment. [Figure 3] FIG. 1 is a partially exploded perspective view showing the basic configuration of a first embodiment. [Figure 4] FIG. 2 is a cross-sectional view of a guide shaft and a sleeve according to the first embodiment. [Figure 5] 4 is another cross-sectional view of the guide shaft and sleeve of the first embodiment. FIG. [Figure 6] FIG. 2 is a partially enlarged view of the guide shaft and sleeve of the first embodiment. [Figure 7] FIG. 10 is a partially exploded perspective view showing the basic configuration of a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a guide shaft and a sleeve according to a second embodiment. [Figure 9] FIG. 10 is a perspective view showing a guide shaft and a sleeve according to a second embodiment. [Figure 10] FIG. 10 is a partially enlarged view of a guide shaft and a sleeve according to a second embodiment. [Figure 11] FIG. 10 is a partially exploded perspective view showing the basic configuration of a third embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a guide shaft and a sleeve according to a third embodiment. [Figure 13] FIG. 10 is a perspective view showing a brake piece, a spring, and a support portion of a third embodiment. [Figure 14] FIG. 10 is a partially enlarged view of a guide shaft, a sleeve, and a brake piece according to a third embodiment. [Figure 15] FIG. 10 is a partially exploded perspective view showing the basic configuration of a fourth embodiment. [Figure 16] FIG. 10 is a cross-sectional view of a guide shaft and a sleeve according to a fourth embodiment. [Figure 17] FIG. 10 is a perspective view showing a guide shaft and a sleeve according to a fourth embodiment. [Figure 18] FIG. 10 is a partially enlarged view of a guide shaft and a sleeve according to a fourth embodiment. [Figure 19]FIG. 10 is a diagram showing a rotated state of the brake piece of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Basic configuration of the invention] [Collision mitigation mechanism] The basic configuration common to all embodiments of the present invention will be described below. FIG. 1 is a perspective view showing the basic configuration of a collision reduction mechanism 10 according to an embodiment of the present invention. This embodiment of the present invention includes guide shafts 12A and 12B, one end of which is fixed by fixed frames 11A and 11B, a movable unit 14 having a sleeve 13, and a brake piece that presses against the guide shafts 12A and 12B. The movable unit 14 is movable in a first direction 15 along the guide shafts 12A and 12B by a voice coil motor (not shown). That is, the guide shafts 12A and 12B extend in the first direction 15. The brake piece generates a force that presses against the guide shafts in a second direction that intersects with the first direction 15.

[0010] In an embodiment of the present invention, the brake pieces are provided in the sleeves of the movable parts or in the fixed frame. In an embodiment of the present invention, the brake pieces or the sleeves 13 advance in the second direction toward the guide shafts 12A and 12B when the movable part 14 moves to one end of the guide shafts 12A and 12B and the movable part 14 or the fixed frames 11A and 11B abut against the brake pieces. This advance generates a force that presses the guide shafts 12A and 12B, and the pressing part presses the guide shafts 12A and 12B.

[0011] [Lens barrel and imaging device] Fig. 2 is a diagram schematically illustrating an example of a lens barrel and an imaging device according to an embodiment of the present invention. As shown in Fig. 2, imaging device 20 has a main body 21 and a lens barrel 22 that is detachable from main body 21. This lens barrel 22 includes a collision reduction mechanism. Therefore, imaging device 20 also includes a collision reduction mechanism.

[0012] Lens barrel 22 has an optical system 23. Main body 21 has a cover glass 24 as an imaging element and a CCD sensor 25. CCD sensor 25 is disposed in main body 21 at a position where the optical axis of optical system 23 in lens barrel 22 attached to main body 21 is the central axis. Main body 21 may have an optical element that does not have substantial refractive power, such as an infrared cut filter, instead of cover glass 24.

[0013] It is more preferable that the imaging device of this embodiment has an image processing unit that electrically processes the captured image data acquired by the imaging element to change the shape of the captured image, and an image correction data storage unit that stores image correction data and an image correction program used to process the captured image data in the image processing unit, for example, to enlarge (zoom) key parts of the image.

[0014] [Embodiment 1] [Configuration of Embodiment 1] A first embodiment of the present invention will be described below. Fig. 3 is a partially exploded perspective view showing the basic configuration of the first embodiment. In the first embodiment, the movable part 34 moves in a first direction 35, which is the optical axis direction, and therefore the guide shaft 32A is fitted into a guide hole of a brake piece 36A in a sleeve 33 of the movable part 34. That is, the brake piece has a guide hole through which the guide shaft is inserted and is disposed inside the sleeve.

[0015] Brake pieces 36A, 36B and a spring 37 are disposed within this sleeve 33. That is, the movable part includes the sleeve and the brake pieces. The brake pieces are disposed within the sleeve and are movable in a first direction. In FIG. 3, to make each component easier to understand, the brake pieces 36A, 36B and spring 37 are depicted as being pulled outward from the sleeve 33, which has a cutout shape. The spring 37 biases the brake pieces 36A, 36B in a direction that presses them against both sides of the sleeve 33. That is, the brake pieces are disposed within the sleeve while being biased toward one end.

[0016] FIG. 4 is a cross-sectional view of the guide shaft 32A of the first embodiment and the sleeve 33 fitted to the guide shaft 32A, taken in the first direction. Although omitted from FIG. 3, both ends of the guide shaft 32A are fixed by fixed frames 31A and 31B. Brake guides 38A and 38B are provided on the fixed frames 31A and 31B, respectively. That is, the fixed portion has a brake guide that abuts against the brake piece when the sleeve reaches one end of the guide shaft. FIG. 4 shows a state in which the movable portion 34 has moved toward one end of the guide shaft 32A (toward the fixed frame 31A). In this state, the brake guide 38A and the rib portion 36A2 of the brake piece 36A abut against each other at an abutment portion 39. That is, the brake piece is formed in a shape inclined with respect to the first direction, and has an abutment portion where the sleeve, having moved toward one end of the guide shaft, abuts against the brake piece.

[0017] The brake piece 36A has a hole with a diameter slightly larger than that of the guide shaft 32A. The brake piece 36A also has an inclined surface 36C that comes into contact with the inclined surface 33C of the sleeve 33. The spring 37 comes into contact with the brake pieces 36A, 36B toward both sides of the sleeve 33 (hereinafter also referred to as the eyepiece side and the objective side), and constantly biases the brake pieces 36A, 36B from the center of the sleeve toward the eyepiece side and the objective side. Because the brake pieces 36A, 36B are biased toward both sides of the sleeve 33 by the spring 37 in this way, they normally do not come into contact with the inclined surface 33C of the sleeve 33 or the guide shaft 32A.

[0018] The collision reduction mechanism of the first embodiment is configured to be compact and space-saving because it is composed of fixed frames 31A and 31B including a movable part 34 including a sleeve 33, guide shaft 32A, brake pieces 36A and 36B, spring 37, and brake guides 38A and 38B. Furthermore, fixed frames 31A and 31B are arranged so that a movable range of movable part 34 is sandwiched between guide shaft 32A for moving movable part 34 in a first direction (hereinafter also referred to as the optical axis direction) 35. A sleeve 33 that fits into guide shaft 32A is provided on movable part 34. Movement of sleeve 33 along guide shaft 32A allows movable part 34 to move in first direction 35. The amount of movement of movable part 34 is limited within a predetermined range by brake guides 38A and 38B provided on fixed frames 31A and 31B.

[0019] 5 is a cross-sectional view of the guide shaft 32A of the first embodiment and the sleeve 33 fitted with the guide shaft 32A, taken in a second direction intersecting the first direction (a state in which the guide shaft 32A is cut into a ring). The brake piece 36A fits over the guide shaft 32A within the sleeve 33. That is, the brake piece 36A is disposed within the sleeve 33 so as to enclose the guide shaft 32A. The brake piece 36A has a shape in which a rib portion 36A2 protrudes from the sleeve.

[0020] [Operation of Embodiment 1] Figure 6 is a partially enlarged view of Figure 4 showing a cross section of the guide shaft 32A and sleeve 33 of embodiment 1. The operation of embodiment 1 will be described below with reference to Figure 6. As also described in Figure 4, the movable part 34 has moved to the fixed frame 31A side of the guide shaft 32A. Specifically, the brake guide 38A provided on the fixed frame 31A and the rib part 36A2 of the brake piece 36A protruding from the sleeve 33 are in contact with each other at the contact part 39.

[0021] As mentioned above, when the power is off, the voice coil motor (not shown) does not generate a self-holding force. Therefore, when the lens barrel is swung, the movable part 34 moves in a first direction toward the eyepiece or object due to its own weight. As shown in FIG. 6 , when the movable part 34 moves and the brake guide 38A contacts the rib portion 36A2 of the brake piece 36A, an inertial force acts on the movable part 34 as indicated by arrow 40, causing it to move further toward the fixed frame 31A. The force indicated by arrow 40 also acts on the sleeve 33 of the movable part 34, causing the inclined surface 36C of the brake piece 36A to contact the inclined surface 33C of the sleeve 33, and the brake piece 36A moves along the inclined surface 33C of the sleeve 33 toward the center of the sleeve 33.

[0022] At this time, the portion of the brake piece 36A facing the guide shaft 32A is pressed toward the center of the guide shaft 32A, which is the second direction, as indicated by arrow 41. The movable part 34 further applies a force toward the fixed frame 31A, and the inclined surface 33C of the fixed brake piece 36A exerts forces on the sleeve 33 as indicated by arrows 42 and 43. As a result, the sleeve 33 is pressed toward the center of the guide shaft 32A in the portion indicated by arrow 43.

[0023] In this way, the portion indicated by arrow 43 serves as a pressing portion, generating a frictional force between sleeve 33 and guide shaft 32A. As a result, when the sleeve moves to one end of the guide shaft and abuts against the brake piece at the abutment portion, it is guided in the second direction by the abutment portion and advances toward the guide shaft, and the inner peripheral surface of the sleeve serves as a pressing portion to press against the guide shaft.

[0024] The kinetic energy of the movable part 34 in the first direction is converted into a force in the second direction toward the center of the guide shaft 32A, generating a frictional force between the sleeve 33 and the guide shaft 32A. This frictional force acts as resistance to the movement of the movable part 34 in the first direction, thereby reducing the force with which the movable part 34 collides with the brake guide 38A of the fixed frame 31A via the brake piece 36A, thereby reducing the collision noise. The frictional force generated between the sleeve 33 and the guide shaft 32A increases as the force with which the movable part 34 attempts to collide with the brake guide 38A increases, so the collision noise is reduced stably regardless of the magnitude of the collision force.

[0025] In addition, a brake piece 36A provided inside the sleeve 33 generates a frictional force between the sleeve 33 and the guide shaft 32A. This allows for the kinetic energy in the first direction to be converted into a force in the second direction with a small space and a small stroke, thereby reducing collision noise.

[0026] [Embodiment 2] [Configuration of Embodiment 2] A second embodiment of the present invention will now be described. Fig. 7 is a partially exploded perspective view showing the basic configuration of the second embodiment. In the second embodiment, the movable part 74 having the sleeve 73 and the guide shaft 72A are the same as the sleeve 33, the movable part 34, and the guide shaft 32A of the first embodiment, and therefore a description thereof will be omitted. Brake pieces 76A and 76B are disposed within the sleeve 73 of the second embodiment, and a leaf spring 77 is provided on the outside thereof. Because the movable part 74 moves in a first direction, which is the optical axis direction, the guide shaft 72A is fitted into a guide hole of the brake piece 76A disposed within the sleeve 73 of the movable part 74.

[0027] That is, the brake pieces have guide holes through which the guide shafts are inserted and are disposed inside the sleeve. Brake pieces 76A and 76B are disposed inside this sleeve 73. That is, the movable part includes the sleeve and the brake pieces. The brake pieces are disposed in the sleeve and are movable in a first direction. In FIG. 7, to make each component easier to understand, the brake pieces 76A and 76B and the leaf spring 77 are shown pulled outward from the sleeve 73, which has a cutout shape. Note that the leaf spring 77 biases in the opposite direction to the direction in which the ribs 76A2 and 76B2 of the brake pieces 76A and 76B are pressed toward the guide shaft 72A.

[0028] Figure 8 is a cross-sectional view of a guide shaft 72A of the second embodiment, taken in a first direction, and a guide hole of a sleeve 73 that fits onto the guide shaft 72A. Brake guides 78A and 78B are provided on fixed frames 71A and 71B, respectively. Figure 8 shows a state in which the movable portion 74 has moved toward the fixed frame 71A of the guide shaft 72A. In this state, the brake guide 78A and the rib portion 76A2 of the brake piece 76A abut at an abutment portion 79. That is, the fixed portion has a brake guide that abuts against the brake piece when the sleeve reaches one end of the guide shaft.

[0029] The brake piece 76A has a hole with a diameter slightly larger than that of the guide shaft 72A. The brake piece 76A also has an inclined surface 76C that abuts against an inclined surface 78C of the brake guide 78A. The leaf spring 77 contacts the brake pieces 76A and 76B and constantly urges the brake pieces 76A and 76B in the direction opposite to the direction in which they are pressed toward the guide shaft 72A. In other words, the brake pieces are urged in the second direction at one end in the first direction within the sleeve and are positioned in a non-contact position with the guide shaft.

[0030] The collision reduction mechanism of the second embodiment is configured to be compact and space-saving because it is composed of a movable part 74 including a sleeve 73, a guide shaft 72A, brake pieces 76A and 76B, fixed frames 71A and 71B including leaf springs 77 and brake guides 78A and 78B. Also, the amount of movement of the movable part 74 is limited to within a predetermined range, as in the first embodiment.

[0031] 9 is a perspective view showing a guide shaft 72A of the second embodiment and a sleeve 73 that fits onto the guide shaft 72A. Although not shown, a brake piece 76A fits onto the guide shaft 72A inside the sleeve 73. That is, the brake piece 76A is disposed in the sleeve 73 so as to enclose the guide shaft 72A. The brake piece 76A also has a shape in which a rib portion 76A2 protrudes from the sleeve. The rib portion 76A2 is provided with an inclined surface 76C.

[0032] [Operation of Embodiment 2] FIG. 10 is a partially enlarged view of FIG. 8 showing a cross section of the guide shaft 72A and the sleeve 73 of the second embodiment. The operation of the second embodiment will be described below with reference to FIG. 8. As described in FIG. 8, the movable part 74 has moved toward the fixed frame 71A of the guide shaft 72A. Specifically, the inclined surface 78C of the brake guide 78A provided on the fixed frame 71A and the inclined surface 76C of the rib portion 76A2 of the brake piece 76A protruding from the sleeve 73 abut against each other at an abutment portion 79. The inclined surface 76C of the rib portion 76A2 is formed in a shape that gradually approaches the guide shaft in the second direction. That is, the brake piece is formed in a shape that gradually approaches the guide shaft in the second direction toward one end, and has an abutment portion where the brake guide abuts against the brake piece when the sleeve reaches one end of the guide shaft.

[0033] When the lens barrel is swung while the power is off, the movable part 74 moves in a first direction toward the eyepiece or the objective lens due to its own weight. As shown in Figure 10, when the movable part 74 moves and the brake guide 78A comes into contact with the rib part 76A2 of the brake piece 76A, a force indicated by arrow 80 acts on the movable part 74 due to inertia, further exerting a force toward the fixed frame 81A. Because the force indicated by arrow 80 from the movable part 74 also acts on the brake piece 76A, the inclined surface 76C of the brake piece 76A is pushed toward the guide shaft 72 along the inclined surface 78C of the brake guide 78A.

[0034] As a result, a force acts on the brake piece 76A in a second direction, indicated by arrow 81, toward the center of the guide shaft 72. As a result, a frictional force is generated between the sleeve 73 and the guide shaft 72A, with the portion indicated by arrow 81 acting as a pressing portion. That is, when the brake piece moves to one end together with the sleeve and abuts against the brake guide at the abutment portion and is guided in the second direction, the brake piece advances toward the guide shaft, and the inner circumferential surface of the guide hole in the brake piece acts as a pressing portion to press against the guide shaft.

[0035] As in the first embodiment, the kinetic energy of the movable part 74 in the first direction is converted into a force in the second direction toward the center of the guide shaft 72A, generating a frictional force between the sleeve 73 and the guide shaft 72A. Therefore, the force with which the movable part 74 collides with the brake guide 78A of the fixed frame 71A via the brake piece 76A can be reduced, reducing the collision noise. Also, as in the first embodiment, the collision noise is reduced stably regardless of the magnitude of the collision force. Furthermore, the kinetic energy in the first direction can be converted into a force in the second direction with a small space and a small stroke, reducing the collision noise.

[0036] [Embodiment 3] [Configuration of Embodiment 3] Hereinafter, a third embodiment of the present invention will be described. Fig. 11 is a partially exploded perspective view showing the basic configuration of the third embodiment. In the third embodiment, the movable part 114 having the sleeve 113 and the guide shaft 112A are the same as the sleeve 33, the movable part 34 and the guide shaft 32A of the first embodiment, and therefore the description thereof will be omitted.

[0037] No brake pieces or the like are provided in the guide holes of the sleeve 113 in the third embodiment. In the third embodiment, the fixed frames 111A and 111B are provided with brake pieces 116A and 116B, respectively. The brake pieces 116A and 116B and the springs 117A and 117B are supported by support portions 118A and 118B provided on the fixed frames 111A and 111B.

[0038] 12 is a cross-sectional view of guide shaft 112A of embodiment 3 and sleeve 113 fitted with guide shaft 112A in a first direction. Support portions 118A and 118B for supporting brake pieces 116A and 116B and springs 117A and 117B are provided on the movable region side of movable portion 114 of fixed frames 111A and 111B, respectively. Inclined surfaces 113C1 and 113C2 are provided on the outer sides of sleeve 113 on the eyepiece side and objective side. Inclined surfaces 113C1 and 113C2 are shaped to gradually approach the guide shaft in the second direction toward the outer side of sleeve 113.

[0039] Inclined surfaces 116C1 and 116C2 are provided on the brake pieces 116A and 116B, respectively, at the portions that come into contact with the movable portion 114. The brake pieces 116A and 116B are biased toward the guide shaft 112A by springs 117A and 117B. That is, the brake pieces are arranged on the fixed portion while being biased toward the guide shaft in the second direction.

[0040] 12 shows the movable part 114 moved toward the fixed frame 111A of the guide shaft 112A. In this state, the inclined surface 116C1 of the brake piece 116A and the inclined surface 113C1 on the eyepiece side of the sleeve 113 are in contact with each other as an abutment. That is, the brake piece and the sleeve are formed in a shape that gradually approaches the guide shaft in the second direction toward one end, and have an abutment portion where the sleeve abuts against the brake piece when the sleeve reaches one end of the guide shaft.

[0041] The collision reduction mechanism of the third embodiment is configured to be compact and space-saving because it is composed of a movable part 114 including a sleeve 113, a guide shaft 112A, brake pieces 116A and 116B, and support parts 118A and 118B including springs 117A and 117B. Also, the amount of movement of the movable part 114 is limited to within a predetermined range, as in the first embodiment.

[0042] Figure 13 is a perspective view showing a brake piece 116A, a spring 117A, and a support portion 118A that supports them, which are provided on a fixed frame 111A of the third embodiment. The brake piece 116A has an inclined surface 116C1 on the side of the guide shaft 112A (not shown) (the lower right side in Figure 13). This inclined surface 116C1 is shaped so that it gradually approaches the guide shaft in the second direction as it approaches the fixed frame 111A. The brake piece 116A is urged toward the guide shaft 112A by a spring 117A and is controlled by a stop mechanism (not shown) to prevent it from approaching the guide shaft 112A more than a predetermined range.

[0043] [Operation of Embodiment 3] Figure 14 is a partially enlarged view of Figure 12 showing cross sections of the guide shaft 112A, sleeve 113, and brake piece 116A of embodiment 3. The operation of embodiment 3 will be described below with reference to Figure 14. As also described in Figure 12, the movable part 114 has moved toward the fixed frame 111A of the guide shaft 112A. Specifically, the inclined surface 116C1 of the brake piece 116A provided on the fixed frame 111A and the inclined surface 113C1 provided on the sleeve 113 are in contact with each other.

[0044] When the lens barrel is swung while the power is off, movable part 114 moves in a first direction toward the eyepiece or objective lens due to its own weight. As shown in Figure 14, when movable part 114 moves and inclined surface 116C1 of brake piece 116A comes into contact with inclined surface 113C1 provided on sleeve 113, a force indicated by arrow 120 acts on movable part 114 due to inertia, generating a further force toward fixed frame 111A. This force indicated by arrow 120 on movable part 114 also acts on brake piece 116A, so that brake piece 116A is pushed along inclined surface 116C1 toward the side opposite guide shaft 112A.

[0045] As a result, a force indicated by arrow 121 acts on brake piece 116A. Meanwhile, a force indicated by arrow 122 acts on sleeve 113 in the opposite direction to that of arrow 121 acting on brake piece 116A, that is, a force directed toward the center of guide shaft 112A. As a result, the portion indicated by arrow 122 acts as a pressing portion, generating a frictional force between sleeve 113 and guide shaft 112A. In other words, when the sleeve moves to one end and abuts against the brake piece at the abutment portion and is guided in the second direction, the inner circumferential surface of the sleeve acts as a pressing portion and advances toward the guide shaft, pressing against the guide shaft.

[0046] As in the first embodiment, the kinetic energy of the movable part 114 in the first direction is converted into a force in the second direction toward the center of the guide shaft 112A, generating a frictional force between the sleeve 113 and the guide shaft 112A. Therefore, the force with which the sleeve 113 of the movable part 114 collides with the brake piece 116A can be reduced, reducing the collision noise. Also, as in the first embodiment, the collision noise is reduced stably regardless of the magnitude of the collision force. Furthermore, the kinetic energy in the first direction can be converted into a force in the second direction with a small space and a small stroke, reducing the collision noise.

[0047] [Embodiment 4] [Configuration of Embodiment 4] A fourth embodiment of the present invention will now be described. Fig. 15 is a partially exploded perspective view showing the basic configuration of the fourth embodiment. In the fourth embodiment, the movable part 154 having the sleeve 153 and the guide shaft 152A are the same as the sleeve 33, the movable part 34, and the guide shaft 32A of the first embodiment, and therefore a description thereof will be omitted. Because the movable part 154 moves in a first direction, which is the optical axis direction, the guide shaft 152A is fitted into a guide hole of a brake piece 156A located inside the sleeve 153 of the movable part 154. That is, the brake piece has a guide hole through which the guide shaft is inserted and is disposed inside the sleeve.

[0048] In the fourth embodiment, brake pieces 156A and 156B are disposed in the guide holes of the sleeve 153. That is, the movable part includes the sleeve and the brake pieces. The brake pieces are disposed in the sleeve and are movable in a first direction. Coil springs 157A and 157B are provided on the outer sides of the sleeves 153 of the brake pieces 156A and 156B, respectively.

[0049] In order to make each component easier to understand, FIG. 15 shows brake pieces 156A, 156B and coil springs 157A, 157B pulled outward from sleeve 153 having a cutout shape.

[0050] FIG. 16 is a cross-sectional view of a guide shaft 152A of the fourth embodiment and a sleeve 153 fitted to the guide shaft 152A in a first direction. The fixed frames 151A and 151B are provided with brake guides 158A and 158B, respectively. FIG. 16 shows a state in which the movable portion 154 has moved toward the fixed frame 151A of the guide shaft 152A. In this state, the brake guide 158A and the rib portion 156A2 of the brake piece 156A abut against each other. That is, the fixed portion has a brake guide that abuts against the brake piece when the sleeve reaches one end of the guide shaft.

[0051] The brake pieces 156A and 156B have holes with a diameter slightly larger than that of the guide shaft 152A. The brake piece 156A also has a guide hole into which the guide shaft 152A fits, and has inclined surfaces 156C1 and 156C2 that form a gap between the brake piece 156A and the guide shaft 152A, and the brake piece 156B also has inclined surfaces 156C3 and 156C4. This gap allows the brake pieces 156A and 156B to tilt. In other words, the guide holes of the brake pieces are shaped to allow the brake pieces to tilt toward the other end of the guide shaft.

[0052] The coil springs 157A and 157B bias the ribs 156A2 and 156B2 of the brake pieces 156A and 156B in a direction that presses them toward the fixed frames 151A and 151B, respectively, causing the brake pieces 156A and 156B to stand up. That is, the brake pieces are positioned so as to be biased to stand up at one end of the sleeve in the first direction.

[0053] The collision reduction mechanism of the fourth embodiment is composed of a movable part 154 including a sleeve 153, a guide shaft 152A, brake pieces 156A and 156B, coil springs 157A and 157B, and fixed frames 151A and 151B including brake guides 158A and 158B. This allows for a compact, space-saving configuration. Similarly to the first embodiment, the amount of movement of the movable part 154 is limited to within a predetermined range.

[0054] Figure 17 is a perspective view showing a guide shaft 152A of the fourth embodiment and a sleeve 153 that fits onto the guide shaft 152A. Although not shown, a brake piece 156A fits onto the guide shaft 152A inside the sleeve 153. The brake piece 156A has a shape in which a rib portion 156A2 protrudes from the sleeve 153. A coil spring 157A is provided on the outside of the sleeve 153 and biases the rib portion 156A2 in a direction that presses it toward the fixed frame 151A (not shown) (to the lower right in Figure 17).

[0055] [Operation of the fourth embodiment] Figure 18 is a partially enlarged view of Figure 16 showing a cross section of the guide shaft 152A and sleeve 153 of embodiment 4. The operation of embodiment 4 will be described below with reference to Figure 18. As also described in Figure 16, the movable part 154 has moved toward the fixed frame 151A side of the guide shaft 152A. Specifically, the brake guide 158A provided on the fixed frame 151A and the rib part 156A2 of the brake piece 156A protruding from the sleeve 153 are in contact with each other.

[0056] When the lens barrel is swung while the power is off, movable part 154 moves in a first direction toward the eyepiece or the objective lens due to its own weight. As shown in Figure 18, when movable part 154 moves and brake guide 158A comes into contact with rib portion 156A2 of brake piece 156A, a force indicated by arrow 160 acts on movable part 154 due to inertia, generating a further force toward fixed frame 151A.

[0057] FIG. 19 is a diagram showing a rotated state of the brake piece 156A of the fourth embodiment. A case where a force indicated by arrow 160 is applied from the sleeve 153 to the brake piece 156A from the state shown in Figure 18 will be described using Figure 19. The tip of the rib portion 156A2 of the brake piece 156A abuts against the brake guide 158A at the abutment portion, thereby fixing the tip of the rib portion 156A2. In addition, a force indicated by arrow 160 is applied from the sleeve 153 to the rib portion 156A2 near the guide shaft 152A. This force acts to rotate the brake piece 156A toward the center of the guide shaft 152A, pushing it into the brake guide 158A, as indicated by arrow 161.

[0058] 19, the brake piece 156A rotates slightly, and the inclined surfaces 156C1 and 156C2 that had formed the gap come into contact with the guide shaft 152A. Furthermore, a force directed toward the center of the guide shaft 152A, as indicated by arrows 162 and 163, acts from the brake piece 156A at the pressing portion, generating a frictional force between the guide shaft 152A and the brake piece 156A. That is, when the brake piece moves to one end together with the sleeve and comes into contact with the brake guide at the contact portion and tilts toward the other end, it advances toward the guide shaft and presses the guide shaft with the inner circumferential surface of the guide hole in the brake piece as the pressing portion.

[0059] In this way, the kinetic energy of the movable part 154 in the first direction is converted into a force in the second direction toward the center of the guide shaft 152A, generating a frictional force between the brake piece 156A and the guide shaft 152A. Therefore, the force of collision between the movable part 154 and the brake guide 158A of the fixed frame 151A via the brake piece 156A can be reduced, and the collision noise is reduced. In addition, the collision noise is reduced stably regardless of the magnitude of the collision force. Furthermore, the kinetic energy in the first direction can be converted into a force in the second direction with a small space and a small stroke, thereby reducing the collision noise.

[0060] This configuration reduces the number of parts compared to conventional products, which is effective in reducing waste disposal, and contributes to achieving Goal 12 of the Sustainable Development Goals (SDGs), "Responsible Consumption and Production."

[0061] 〔summary〕 The collision reduction mechanism (10) according to aspect 1 of the present invention comprises a guide shaft (12A, 12B) having one end fixed by a fixed portion (11A, 11B) and extending in a first direction, a movable portion (14) having a sleeve (13) through which the guide shaft is inserted and movable in the first direction by the sleeve, and a brake piece (36A, 36B) that generates a force pressing against the guide shaft in a second direction intersecting the first direction, wherein the brake piece or the sleeve includes a pressing portion that advances toward the guide shaft in the second direction and presses against the guide shaft when the movable portion moves to the one end of the guide shaft and the movable portion or the fixed portion abuts against the brake piece.

[0062] According to aspect 1 of the present invention, the kinetic energy of the movable part in a first direction is converted into a force in a second direction toward the center part of the guide shaft, thereby reducing the force with which the movable part collides with the brake guide of the fixed part, and reducing the collision noise.

[0063] A collision reduction mechanism according to aspect 2 of the present invention is the same as that of aspect 1, wherein the movable part includes the sleeve and the brake piece, and the brake piece is disposed in the sleeve and is movable in the first direction.

[0064] In the collision reduction mechanism according to aspect 2 of the present invention, the frictional force generated between the sleeve and the guide shaft acts as resistance to movement of the movable part in the first direction, thereby reducing the force with which the movable part collides with the brake guide of the fixed part via the brake piece, thereby reducing the collision noise.

[0065] A collision-reduction mechanism according to a third aspect of the present invention is the collision-reduction mechanism of the second aspect, wherein the brake piece has a guide hole through which the guide shaft is inserted and is disposed inside the sleeve.

[0066] According to the third aspect of the present invention, a brake piece provided inside the sleeve generates friction between the sleeve and the guide shaft, which saves space and reduces impact noise by converting kinetic energy in a first direction into force in a second direction with a small stroke.

[0067] A collision reduction mechanism according to aspect 4 of the present invention is such that, in the above-mentioned aspect 3, at least one of the brake piece and the sleeve is formed in a shape that is inclined with respect to the first direction, and further has an abutment portion (39) at which the sleeve, when moved to the one end of the guide shaft, abuts against the brake piece, the brake piece is positioned within the sleeve so as to be biased toward the one end, the fixed portion further has a brake guide (38A, 38B) that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, and when the sleeve moves to the one end of the guide shaft and abuts against the brake piece at the abutment portion, it is guided in the second direction by the abutment portion and advances toward the guide shaft, and the inner surface portion of the sleeve serves as the pressing portion to press against the guide shaft.

[0068] According to aspect 4 of the present invention, the frictional force generated between the sleeve and the guide shaft increases the greater the force with which the movable part attempts to collide with the brake guide, so that the impact noise is reduced stably regardless of the magnitude of the impact force.

[0069] A collision reduction mechanism according to aspect 5 of the present invention is, in the above-mentioned aspect 3, wherein the fixed portion further includes a brake guide that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, and at least one of the brake piece and the brake guide is formed in a shape that gradually approaches the guide shaft in the second direction toward the one end, and the brake guide further includes an abutment portion that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, and the brake piece is biased in the second direction at one end in the first direction within the sleeve and is positioned in a non-contact position with respect to the guide shaft, and when the brake piece moves to the one end together with the sleeve and abuts against the brake guide at the abutment portion and is guided in the second direction, the brake piece advances toward the guide shaft and presses the guide shaft with the inner surface portion of the guide hole of the brake piece as the pressing portion.

[0070] According to the fifth aspect of the present invention, the force of collision between the movable part and the brake guide of the fixed part via the brake piece can be reduced, thereby reducing the collision noise. Furthermore, the reduction in the collision noise is stable regardless of the magnitude of the collision force.

[0071] A collision reduction mechanism according to aspect 6 of the present invention is such that, in the above-mentioned aspect 1, at least one of the brake piece and the sleeve is formed in a shape that gradually approaches the guide shaft in the second direction toward the one end, and further has an abutment portion where the sleeve abuts against the brake piece when the sleeve reaches the one end of the guide shaft, the brake piece is biased toward the guide shaft in the second direction and is positioned on the fixed portion, and when the sleeve moves to the one end and abuts against the brake piece at the abutment portion and is guided in the second direction, a portion of the inner surface of the sleeve advances toward the guide shaft as the pressing portion and presses the guide shaft.

[0072] According to the sixth aspect of the present invention, the device is configured to be compact and space-saving, since it is composed of a movable part including a sleeve, a guide shaft, a brake block, and a support part including a spring. In addition, the movement amount of the movable part is limited within a predetermined range.

[0073] A collision reduction mechanism according to aspect 7 of the present invention is such that, in aspect 3 above, the brake piece is biased and positioned so as to stand up at one end of the sleeve in the first direction, the guide hole of the brake piece is formed in a shape that allows the brake piece to tilt toward the other end side of the guide shaft, the fixed portion further has a brake guide that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, and when the brake piece moves to the one end together with the sleeve and abuts against the brake guide at the abutment portion and tilts toward the other end, it advances toward the guide shaft and presses against the guide shaft with the inner surface portion of the guide hole of the brake piece as the pressing portion.

[0074] According to the seventh aspect of the present invention, the brake device is configured from a movable part including a sleeve, a guide shaft, a brake piece, a coil spring, and a fixed part including a brake guide, thereby saving space and achieving a compact configuration.

[0075] A lens barrel according to an eighth aspect of the present invention has the collision reduction mechanism according to any one of the first to seventh aspects.

[0076] An imaging device according to a ninth aspect of the present invention has the collision reduction mechanism according to any one of the first to seventh aspects.

[0077] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of symbols]

[0078] 10 Collision mitigation mechanism 20 Imaging device 21 Main Unit 22 Telescope tube 11A, 11B, 31A, 31B, 71A, 71B, 111A, 111B, 151A Fixed frame 12A, 12B, 32A, 32B, 72A, 72B, 112A, 112B, 152A guide shaft 13, 33, 73, 113, 153 sleeves 14, 34, 74, 114, 154 Moving parts 36A, 36B, 76A, 76B, 116A, 116B, 156A, 156B brake link 37, 117A, 117B springs 77 Leaf spring 157A, 157B coil springs 38A, 38B, 78A, 78B, 158A, 158B Brake guide

Claims

1. a guide shaft having one end fixed by a fixing portion and extending in a first direction; a movable portion having a sleeve through which the guide shaft is inserted and movable in the first direction by the sleeve; a brake piece that generates a force that presses the guide shaft in a second direction that intersects with the first direction, the brake piece or the sleeve includes a pressing portion that advances toward the guide shaft in the second direction and presses the guide shaft when the movable portion moves to the one end of the guide shaft and the fixed portion abuts against the brake piece, the movable portion includes the sleeve and the brake piece, The brake piece is disposed on the sleeve and is movable in the first direction. Collision mitigation mechanism.

2. 2. The collision reduction mechanism according to claim 1, wherein the brake piece has a guide hole through which the guide shaft is inserted, and a portion of the brake piece having the guide hole is disposed inside the sleeve.

3. At least one of the brake piece and the sleeve is formed in a shape inclined with respect to the first direction, and further has an abutment portion at which the sleeve, which has moved to the one end of the guide shaft, abuts against the brake piece, The brake piece is disposed in the sleeve while being biased toward the one end, the fixing portion further includes a brake guide that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, 3. The collision reduction mechanism according to claim 2, wherein when the sleeve moves to the one end of the guide shaft and abuts against the brake piece at the abutment portion, the sleeve is guided in the second direction by the abutment portion and advances toward the guide shaft, and an inner surface portion of the sleeve serves as the pressing portion to press against the guide shaft.

4. the fixing portion further includes a brake guide that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, At least one of the brake piece and the brake guide is formed in a shape that gradually approaches the guide shaft in the second direction toward the one end, and further has an abutment portion where the brake guide abuts against the brake piece when the sleeve reaches the one end of the guide shaft, the brake piece is biased in the second direction at one end in the first direction within the sleeve and is disposed at a position where it does not contact the guide shaft, When the brake piece moves to the one end together with the sleeve and abuts against the brake guide at the abutment portion and is guided in the second direction, the brake piece advances toward the guide shaft and presses the guide shaft with an inner peripheral surface of the guide hole of the brake piece as the pressing portion. The collision mitigation mechanism of claim 2 .

5. The brake piece is biased and arranged to stand up at one end of the sleeve in the first direction, The guide hole of the brake piece is formed in a shape that allows the brake piece to tilt toward the other end side of the guide shaft, the fixing portion further includes a brake guide that abuts against the brake piece when the sleeve reaches the one end of the guide shaft, When the brake piece moves to the one end together with the sleeve and abuts against the brake guide at the abutment portion and tilts toward the other end, the brake piece advances toward the guide shaft and presses the guide shaft with the inner peripheral surface of the guide hole of the brake piece as the pressing portion. The collision mitigation mechanism of claim 2 .

6. A lens barrel having the collision reduction mechanism according to any one of claims 1 to 5.

7. An imaging device comprising the collision reduction mechanism according to any one of claims 1 to 5.

Images