Imaging device

Abstract

The present invention provides an imaging device that can more effectively dampen vibrations generated by the opening and closing of the shutter. [Solution] The imaging device includes a shutter unit having a shutter that opens and closes in a direction intersecting the optical axis, and a first spring, a second spring, and a third spring arranged at first, second, and third locations of the shutter unit, respectively, which expand and contract in a direction along the optical axis to absorb vibrations generated when the shutter opens and closes. The first spring has a larger expansion and contraction range than the second and third springs.

Description

Technical Field

[0001] The technology of the present disclosure relates to an imaging device.

[0002] Patent Document 1 describes an imaging device having an image sensor that captures a subject image, a shutter that controls the exposure time of the image sensor by running a shutter blade, a holding member that holds the shutter movably in a plane orthogonal to the imaging optical axis, and a first biasing member that biases the shutter in a first direction in the plane. The shutter has a contact portion that contacts a positioning portion provided on the holding member to position the shutter at a predetermined position in the first direction. The imaging device has a first buffer member that is movable from the predetermined position against the biasing force of the first biasing member and contacts the shutter that returns to the predetermined position by the biasing force of the first biasing member.

[0003] Patent Document 2 describes an optical device that incorporates a light amount adjustment device that completes a mechanical force transmission mechanism within itself and operates without receiving mechanical force supply from the outside, and the light amount adjustment device is non-rigidly supported via a buffer member having vibration and sound wave blocking properties.

[0004] Patent Document 3 describes an imaging device including a shutter unit having a shutter that adjusts the light amount of subject light incident on an image sensor via an imaging optical system, and the shutter unit is arranged in a frame. The imaging device includes at least three or more elastic members. At least three or more elastic members are arranged on the outer periphery of the contour of the shutter unit when viewed from the front, and all the elastic members arranged on the outer periphery support the shutter unit by pressing the shutter unit from the frame side. Each of all the elastic members arranged on the outer periphery elastically deforms in a first direction, which is the direction of pressing the shutter unit from the frame side, and a second direction, which is a direction perpendicular to the first direction, and the first directions of each of all the elastic members arranged on the outer periphery intersect with each other at a specific location inside the contour.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-039332 [Patent Document 2] Japanese Patent Application Publication No. 06-067259 [Patent Document 3] Patent No. 7463537 [Overview of the project]

[0006] One embodiment of the technology described herein provides an imaging device capable of more effectively damping vibrations generated by the opening and closing of a shutter. [Means for solving the problem]

[0007] The imaging apparatus of this disclosure comprises a shutter unit having a shutter that opens and closes in a direction intersecting the optical axis, and at least three vibration absorbing members arranged at at least three locations on the shutter unit, which expand and contract in a direction along the optical axis to absorb vibrations generated when the shutter opens and closes, wherein one of the at least three vibration absorbing members, the first vibration absorbing member, has a larger expansion and contraction range than the other vibration absorbing members.

[0008] The first vibration absorbing member is preferably positioned at the first location in the shutter unit where the maximum amount of vibration occurs.

[0009] Preferably, at least two of the three locations are the second location where the greatest load occurs and the third location which is situated between the second location and the center of gravity of the shutter unit.

[0010] It is preferable that vibration-absorbing members be placed in four or more locations on the shutter unit.

[0011] The vibration-absorbing member is preferably a spring.

[0012] It is preferable that the spring of the first vibration absorbing member has a larger initial load than the springs of the other vibration absorbing members.

[0013] Among at least three locations, two locations are the second location where the maximum load occurs and the third location sandwiching the center of gravity of the shutter unit and the second location. Springs arranged at the second location and the third location preferably have a spring constant larger than that of springs other than those arranged at the second location and the third location.

[0014] The vibration absorption member is preferably an elastic ball.

[0015] The ball of the first vibration absorption member preferably has a larger diameter than the balls other than the first vibration absorption member.

[0016] The ball preferably rolls on a surface having the optical axis as the normal.

[0017] The shutter unit preferably has a vibration damping member for damping the vibration of the surface having the optical axis as the normal.

[0018] The shutter unit preferably has a weight attached thereto for changing the position of the center of gravity.

Brief Description of the Drawings

[0019] [Figure 1] It is a front view of the imaging device. [Figure 2] It is a rear view of the imaging device. [Figure 3] It is a block diagram showing the electrical configuration of the imaging device. [Figure 4] It is a view showing the metal housing and the shutter unit. [Figure 5] It is a view of the shutter unit seen from the rear. [Figure 6] It is a view of the shutter unit seen from the right. [Figure 7] It is a view of the shutter unit seen from below. [Figure 8] It is a view showing the load applied to the shutter unit and the first location, the second location, and the third location. [Figure 9]It is a diagram showing a first spring, a second spring, and a third spring that expand and contract in a direction along the optical axis to absorb vibrations generated as the shutter opens and closes. [Figure 10] It is a table showing the initial loads of the first spring to the third spring, the magnitude relationship of the initial loads, the spring constants, and the magnitude relationship of the spring constants. [Figure 11] It is a diagram showing an example in which springs are arranged at four locations of the shutter unit. [Figure 12] It is a diagram showing a second embodiment using a ball having elasticity as a vibration suppression member. [[ID=!!]] [Figure 13] It is a diagram showing a housing portion of the ball. [Figure 14] It is a diagram showing an example in which a cushion for damping vibrations of a plane having the optical axis as a normal line is provided. [Figure 15] It is a diagram showing a third embodiment in which a weight for changing the position of the center of gravity is attached. [Figure 16] It is a diagram showing a tension spring.

Mode for Carrying Out the Invention

[0020] [First Embodiment]

[0021] As an example, as shown in Figures 1 and 2, the imaging device 10 is, for example, a digital camera and comprises a device body 11. The device body 11 has a metal housing 12 covered with a resin cover or the like. An imaging lens 14 and the like are located on the front 13 of the device body 11. A liquid crystal monitor 16 and the like are located on the rear 15 of the device body 11, which faces the front 13. Furthermore, various operating members such as a power switch integrated release button (hereinafter simply referred to as the release button) 18 are located on the top 17 of the device body 11, which connects the front 13 and the rear 15. A tripod screw hole (not shown) and the like are located on the bottom 19 of the device body 11, which is the other surface connecting the front 13 and the rear 15. The imaging device 10 may also be an interchangeable-lens camera in which the imaging lens 14 can be replaced. In the following, the side with the top 17 may be referred to as "upper" and the side with the bottom 19 as "lower". In addition, the side with the release button 18 may be referred to as "right," and the side opposite the release button 18 in the Y-axis direction may be referred to as "left." Furthermore, the front side 13 may be referred to as "front," and the rear side 15 may be referred to as "back."

[0022] An image sensor 20 is positioned behind the imaging lens 14. The image sensor 20 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The image sensor 20 has a rectangular imaging surface 21 for imaging a subject. Two orthogonal sides of the imaging surface 21 are parallel to the Y-axis and Z-axis directions, respectively. The center of the imaging surface 21 coincides with the optical axis OA of the imaging lens 14. The optical axis OA and the imaging surface 21 are orthogonal to each other; that is, the optical axis OA is the normal to the imaging surface 21. The imaging surface 21 receives light from the subject. As is well known, pixels that convert the received subject light into electrical signals are arranged two-dimensionally along the Y-axis and Z-axis directions on the imaging surface 21.

[0023] Here, when the bottom surface 19 of the device body 11 is placed on a horizontal surface, the Y-axis direction is horizontal and the Z-axis direction is vertical. The Y-axis direction is the width direction of the device body 11, and the Z-axis direction is the height direction of the device body 11. The X-axis direction, which is perpendicular to the Y-axis and Z-axis directions, is horizontal, just like the Y-axis direction, and is the depth direction of the device body 11. The X-axis direction is parallel to the optical axis OA. Note that the term "orthogonal" and other angle-related terms include not only the meaning of perfect orthogonality, but also the meaning of approximately orthogonality, which includes tolerances in design and manufacturing, such as an error of about ±10% of the design value. Similarly, the term "parallel" and other terms include not only the meaning of perfect parallelism, but also the meaning of approximately parallelity, which includes tolerances in design and manufacturing, such as an error of about ±10% of the design value. Furthermore, the term "matching" and other terms include not only the meaning of perfect matching, but also the meaning of approximately matching, which includes tolerances in design and manufacturing, such as an error of about ±10% of the design value.

[0024] As an example, as shown in Figure 3, the imaging lens 14 has multiple types of lenses for forming an image of the subject on the image sensor 20. Specifically, the imaging lens 14 has an objective lens 25, a focusing lens 26, and a zoom lens 27. These lenses 25 to 27 are arranged in this order from the object side (subject side) to the image-forming side (image sensor 20 side). Although simplified in Figure 3, each lens 25 to 27 is actually a lens group made up of multiple lenses combined together.

[0025] The focus lens 26 is provided with a focus lens drive mechanism 28, and the zoom lens 27 is provided with a zoom lens drive mechanism 29. The focus lens drive mechanism 28 includes a focus cam ring that holds the focus lens 26 and has a cam groove formed on its outer circumference, a focus motor that moves the focus cam ring along the optical axis OA by rotating the focus cam ring around the optical axis OA, and a driver for the focus motor. Similarly, the zoom lens drive mechanism 29 includes a zoom cam ring that holds the zoom lens 27 and has a cam groove formed on its outer circumference, a zoom motor that moves the zoom cam ring along the optical axis OA by rotating the zoom cam ring around the optical axis OA, and a driver for the zoom motor. The focus cam ring and the zoom cam ring can also be rotated manually by the user from the outside of the lens barrel. In other words, the imaging device 10 can adjust the focus and change the focal length electrically using the focus motor and zoom motor, or manually by the user.

[0026] An aperture 30 is positioned on the imaging side of the imaging lens 14. The aperture 30 is, for example, an iris diaphragm, and is composed of a combination of multiple aperture blades. The aperture 30 adjusts the amount of light passing through by simultaneously moving the aperture blades with a cam mechanism, thereby opening and closing the central opening formed by the inner edges of the aperture blades, i.e., changing the opening degree of the opening.

[0027] The aperture 30 is provided with an aperture opening adjustment mechanism 31. The aperture opening adjustment mechanism 31 includes an aperture motor for opening and closing the aperture blades, and a driver for the aperture motor. The aperture 30 can also be opened and closed manually by the user. In other words, the imaging device 10 can adjust the opening of the aperture 30 electrically using the aperture motor, or manually by the user.

[0028] Various motors, such as the focus motor, zoom motor, and aperture motor, are, for example, stepping motors. In this case, the position of the focus lens 26 and the zoom lens 27 on the optical axis OA, as well as the opening degree of the aperture 30, can be derived from the drive amounts of the focus motor, zoom motor, and aperture motor. Alternatively, instead of using the drive amounts of the focus motor and zoom motor, position sensors may be provided to detect the positions of the focus lens 26 and the zoom lens 27.

[0029] The motors (focus motor, zoom motor, and aperture motor) or electrical components such as drivers of each drive mechanism 28, 29, and 31 are connected to the control unit 32. The electrical components of each drive mechanism 28, 29, and 31 are driven under the control of the control unit 32. More specifically, the control unit 32 drives the electrical components of each drive mechanism 28, 29, and 31 by issuing drive signals in response to user instructions input via the operation unit 33. For example, if an instruction to change the angle of view to the telephoto side is input via the angle of view change switch included in the operation unit 33, the control unit 32 issues a drive signal to the driver of the zoom motor of the zoom lens drive mechanism 29, causing the zoom lens 27 to move to the telephoto side.

[0030] The operation unit 33 is a general term for user-operated components, including the release button 18 mentioned above, as well as the menu button and the directional keys. Here, the release button 18 is a two-stage push button that can be half-pressed and fully pressed. Half-pressing the release button 18 signals the camera to prepare for still image or video recording, and fully pressing signals the camera to start still image or video recording.

[0031] The control unit 33 also includes a mode switch for switching the operating mode of the imaging device 10. The operating modes include still image shooting mode, video shooting mode, image playback mode, and setting mode. The still image shooting mode includes not only the normal shooting mode for taking a single still image, but also a continuous shooting mode for continuously taking still images at a predetermined shooting interval, for example, a frame rate of 5fps (frames per second) to 10fps. The continuous shooting mode is activated, for example, when the release button 18 is held fully pressed for a predetermined time or longer (for example, 1 second or more). The continuous shooting mode ends when the fully pressed state of the release button 18 is released.

[0032] The focus motor, zoom motor, and aperture motor output drive amounts to the control unit 32. The control unit 32 derives the position of the focus lens 26, the position of the zoom lens 27, and the opening degree of the aperture 30 on the optical axis OA from the drive amounts.

[0033] An image sensor driver 34 is connected to the image sensor 20. The image sensor driver 34 is connected to the control unit 32. Under the control of the control unit 32, the image sensor driver 34 controls the timing of image acquisition by the image sensor 20 by supplying vertical scanning signals and horizontal scanning signals to the image sensor 20.

[0034] A blur correction unit 35 is attached to the image sensor 20. The blur correction unit 35 has a blur correction function. The blur correction function is a function to suppress the relative positional displacement between the subject light incident on the imaging surface 21 and the imaging device 10, which is caused by vibrations applied to the main body of the device 11. Vibrations applied to the main body of the device 11 include user hand tremors, etc.

[0035] The image stabilization function includes, for example, a movable frame held by a fixed frame fixed to a metal housing 12, and an actuator such as a voice coil motor that moves the movable frame, to which the image sensor 20 is attached, along the Y-axis and Z-axis directions (YZ plane). This image stabilization function moves the image sensor 20 in the Y-axis direction and / or the Z-axis direction by an amount that cancels out the misalignment.

[0036] In this specification, "positional misalignment" in the context of vibrations applied to the device body 11 refers to the phenomenon caused by the change in the optical axis OA relative to the subject due to vibrations. A change in the optical axis OA means that the optical axis OA is tilted with respect to the reference axis (for example, the optical axis OA before the misalignment occurs) due to the misalignment. In this specification, canceling out the misalignment includes not only eliminating the misalignment but also reducing it.

[0037] A stabilization driver 36 is connected to the image stabilization unit 35. The image stabilization driver 36 is connected to the control unit 32. The image stabilization driver 36 operates the image stabilization unit 35 under the control of the control unit 32.

[0038] A shutter 37 is positioned between the imaging lens 14 and the image sensor 20. The shutter 37 is, for example, a focal-plane shutter having a front curtain and a rear curtain. A shutter drive mechanism 38 is connected to the shutter 37. The shutter drive mechanism 38 includes an electromagnet for holding the front curtain and the rear curtain and releasing the holding to move the front curtain and the rear curtain, a motor 56 (see Figure 4, etc.), a charge lever 57 (see Figure 4, etc.), and a driver, etc. The shutter drive mechanism 38 is driven under the control of the control unit 32 to open and close the shutter 37.

[0039] The control unit 32 is connected to various components such as the image input controller 40, image memory 41, and image processing unit 42 via a bus line 43. Other components connected to the bus line 43 include VRAM (Video Random Access Memory) 44, display control unit 45, media controller 46, and instruction receiving unit 47. Although not shown in the diagram, the bus line 43 is also connected to a strobe drive control unit that controls the operation of the strobe device, an external communication interface (I / F) that communicates with external devices via connection terminals such as a USB (Universal Serial Bus) terminal, and a wireless communication interface (I / F) that communicates with external devices via a wireless antenna.

[0040] The image input controller 40 receives image data obtained by capturing the subject light from the image sensor 20. The image input controller 40 outputs the image data to the image memory 41. The image memory 41 is, for example, SDRAM (Synchronous Dynamic Random Access Memory) and temporarily stores the image data.

[0041] The image processing unit 42 reads unprocessed image data from the image memory 41. The image processing unit 42 performs various image processing operations on the image data. These operations include, for example, offset correction, sensitivity correction, pixel interpolation, white balance correction, gamma correction, demosaicing, luminance signal and chrominance signal generation, edge enhancement, and color correction. The image processing unit 42 then writes the processed image data back to the image memory 41.

[0042] Image data that has undergone various image processing, intended for display as a live view image (also called a through image), is input to VRAM44 from image memory41. VRAM44 has an area for storing image data for two consecutive frames. Image data stored in VRAM44 is sequentially overwritten with new image data. VRAM44 sequentially outputs the newer image data from the two consecutive frames of image data to display control unit45.

[0043] The display control unit 45 performs the function of a so-called video encoder, converting image data from the VRAM 44 into video data and outputting it to the liquid crystal monitor 16. This allows the user to view the live view image through the liquid crystal monitor 16. The display frame rate of the live view image is, for example, 60fps.

[0044] When the shutter release button 18 is fully pressed to initiate still image or video recording, the image processing unit 42 compresses the image data in the image memory 41. For still images, the image processing unit 42 compresses the image data using, for example, the JPEG (Joint Photographic Experts Group) format. For videos, the image processing unit 42 compresses the image data using, for example, the MPEG (Moving Picture Experts Group) format. The image processing unit 42 then outputs the compressed image data to the media controller 46.

[0045] The media controller 46 records the compressed image data from the image processing unit 42 onto the memory card 48. The memory card 48 is detachably mounted in a memory card slot (not shown).

[0046] When the image playback mode is selected via the mode switch on the operation unit 33, the media controller 46 reads image data from the memory card 48 and outputs it to the image processing unit 42. The image processing unit 42 performs a decompression process on the image data from the memory card 48. The decompressed image data is output to the display control unit 45. The display control unit 45 converts the image data into video data and outputs it to the liquid crystal monitor 16. As a result, the user can view the playback image through the liquid crystal monitor 16.

[0047] The instruction receiving unit 47 receives various operation instructions from the user via the operation unit 33 and the touch panel 49, which is integrally provided with the liquid crystal monitor 16. The instruction receiving unit 47 outputs the received operation instructions to the control unit 32 via the bus line 43. The touch panel 49 is superimposed on the display surface of the liquid crystal monitor 16. The touch panel 49 recognizes various operation instructions from the user by detecting contact with the user's finger or a dedicated indicator such as a stylus pen.

[0048] An angular velocity sensor 50 is connected to the control unit 32. The angular velocity sensor 50 is located in a predetermined position within the device body 11, for example, within the grip section where the user's right hand rests during shooting. The angular velocity sensor 50 detects the amount of vibration (shake) applied to the device body 11. One angular velocity sensor 50 is provided for each of the three axes: pitch, yaw, and roll. In this example, the pitch axis is the Y-axis, the yaw axis is the Z-axis, and the roll axis is the X-axis. The angular velocity sensor 50 for the pitch axis detects the amount of rotation around the Y-axis, which is the pitch axis, i.e., the amount of vertical vibration (vertical shake). The angular velocity sensor 50 for the yaw axis detects the amount of rotation around the Z-axis, which is the yaw axis, i.e., the amount of polarized vibration (polarized shake). The angular velocity sensor 50 for the roll axis detects the amount of rotation around the X-axis, which is the roll axis, i.e., the amount of lateral vibration (lateral shake).

[0049] As shown in Figure 4, a view of the metal housing 12 from the rear, a shutter unit 55 is attached to the metal housing 12. The shutter unit 55 is equipped with the aforementioned shutter 37 and shutter drive mechanism 38. The shutter 37 is positioned slightly to the left of the center of the shutter unit 55. The shutter 37 opens and closes in a direction intersecting the optical axis OA, in this case in the Z-axis direction perpendicular to the optical axis OA. The shutter drive mechanism 38 is positioned at the right end of the shutter unit 55. The shutter drive mechanism 38 includes the aforementioned motor 56 and charge lever 57, etc. The motor 56 is positioned slightly to the upper right of the shutter drive mechanism 38, and the charge lever 57 is positioned below the shutter drive mechanism 38. The charge lever 57 moves back and forth in the Y-axis direction.

[0050] The shutter unit 55 is connected to the metal housing 12 via three springs: a first spring 58A, a second spring 58B, and a third spring 58C. The first to third springs 58A are compression springs. The first spring 58A is positioned slightly to the right of the center of the lower end of the shutter unit 55. The first spring 58A expands and contracts in the Z-axis direction. The second spring 58B is positioned slightly above the center of the left end of the shutter unit 55. The second spring 58B expands and contracts in the Y-axis direction. The third spring 58C is positioned at the upper right end of the shutter unit 55. The third spring 58C expands and contracts in a direction inclined at a predetermined angle (e.g., 15°) with respect to the Y-axis.

[0051] The first spring 58A to the third spring 58C expand and contract in their respective directions, absorbing vibrations in the plane on which the shutter 37 opens and closes, which occur in the shutter unit 55 as the shutter 37 opens and closes. The plane on which the shutter 37 opens and closes is, in other words, a plane perpendicular to the optical axis OA, which in this case is the YZ plane. As will be described later, the shutter unit 55 is slightly tilted with respect to the YZ plane in an equilibrium state where no vibrations occur as a result of the opening and closing of the shutter 37. Therefore, strictly speaking, the plane on which the shutter 37 opens and closes is a plane that is almost perpendicular to the optical axis OA.

[0052] As an example, as shown in Figures 5, 6, and 7, the center of gravity CG of the shutter unit 55 is located near the center of the front right side, due to the shutter drive mechanism 38 being positioned at the far right. In other words, the center of gravity CG is located in a position different from the center. In particular, as shown in Figure 7, the center of gravity CG is located in front of the trajectory of the reciprocating movement of the charge lever 57, indicated by the double arrow.

[0053] As an example, as shown in Figure 8, the shutter unit 55 is subjected to loads mainly indicated by arrows labeled LA and LB due to the opening and closing of the shutter 37, the rotational drive and torque of the motor 56, and the reciprocating movement of the charge lever 57. Load LA is a load around the Y axis, i.e., the pitch axis. Load LA tilts the upper side of the shutter unit 55 forward (tilts the lower side backward). Load LB is a load around the Z axis, i.e., the yaw axis. Load LB tilts the right side of the shutter unit 55 forward (tilts the left side backward). Therefore, the location where the maximum amount of vibration occurs in the shutter unit 55 is the first location 60A in the upper right. Also, the location where the maximum load occurs in the shutter unit 55 is the second location 60B in the lower right where the charge lever 57 is located.

[0054] As an example, as shown in Figure 9, the shutter unit 55 is further connected to the metal housing 12 via three springs: a first spring 65A, a second spring 65B, and a third spring 65C. The first to third springs 65A and 65C are compression springs. The first spring 65A is located at the first location 60A. The second spring 65B is located at the second location 60B. The third spring 65C is located at the third location 60C. The third location 60C is located between the second location 60B and the center of gravity CG of the shutter unit 55. More specifically, the third location 60C is located diagonally to the upper left of the second location 60B, which is in the lower right (see also Figure 5).

[0055] One end of the first spring 65A, the second spring 65B, and the third spring 65C are attached to the first location 60A, the second location 60B, and the third location 60C, respectively. The other ends of the first spring 65A, the second spring 65B, and the third spring 65C are attached to the rear surface (hereinafter referred to as the rear surface) 59 (see Figure 4) of the metal housing 12, which is opposite the first location 60A, the second location 60B, and the third location 60C.

[0056] The first spring 65A to the third spring 65C all expand and contract in the X-axis direction, i.e., along the optical axis OA. The first spring 65A is slightly longer than the second spring 65B and the third spring 65C. Therefore, the expansion and contraction range of the first spring 65A is greater than that of the second spring 65B and the third spring 65C. Because the expansion and contraction range of the first spring 65A is greater than that of the second spring 65B and the third spring 65C, the shutter unit 55 is slightly tilted with the upper right side towards the rear (and the lower left side towards the front) in the equilibrium state. The first spring 65A to the third spring 65C are examples of "vibration absorbing members" according to the technology of this disclosure. The first spring 65A is an example of the "first vibration absorbing member" and "springs other than the springs placed at the second and third locations" according to the technology of this disclosure. Furthermore, the second spring 65B and the third spring 65C are examples of "other vibration absorbing members" and "springs other than the first vibration absorbing member" related to the technology of this disclosure.

[0057] The first spring 65A to the third spring 65C expand and contract in the X-axis direction, thereby absorbing vibrations in the shutter unit 55 that occur as the shutter 37 opens and closes, vibrations other than those in the plane in which the shutter 37 opens and closes. These vibrations other than those in the plane in which the shutter 37 opens and closes are vibrations in the XZ plane around the Y axis, which is the pitch axis (vertical vibrations), and vibrations in the XY plane around the Z axis, which is the yaw axis (polarized vibrations).

[0058] As an example, as shown in Table 70 of Figure 10, the initial load IL1 of the first spring 65A is greater than the initial load IL2 of the second spring 65B and the initial load IL3 of the third spring 65C (IL1 > IL2, IL3). Also, the spring constant SC2 of the second spring 65B and the spring constant SC3 of the third spring 65C are greater than the spring constant SC1 of the first spring 65A (SC2, SC3 > SC1). Note that the initial load can be determined by multiplying the length of the spring in its unextended state by the spring constant.

[0059] Next, the operation of the above configuration will be explained. In still image shooting mode, when the user fully presses the release button 18 to instruct the start of still image shooting, the motor 56 and charge lever 57 of the shutter drive mechanism 38 are driven under the control of the control unit 32, causing the shutter 37 to open and close in the Z-axis direction. Of the vibrations generated by the opening and closing of the shutter 37, vibrations in the plane over which the shutter 37 opens and closes are absorbed by the expansion and contraction of the first spring 58A to the third spring 58C in their respective directions, as shown in Figures 4 and 5. In addition, vibrations other than those in the plane over which the shutter 37 opens and closes are absorbed by the expansion and contraction of the first spring 65A to the third spring 65C in the X-axis direction, as shown in Figure 9.

[0060] As shown in Figure 9, the first spring 65A of the first to third springs 65A to 65C has a larger range of expansion and contraction than the second spring 65B and the third spring 65C. Therefore, the shutter unit 55 in the equilibrium state can be tilted slightly with respect to the YZ plane in advance to match the vibration characteristics associated with the opening and closing of the shutter 37. Consequently, it becomes possible to more effectively dampen vibrations generated by the opening and closing of the shutter 37. This effect effectively suppresses malfunctions of the image stabilization unit 35 caused by vibrations generated by the opening and closing of the shutter 37, which can result in blurred images being captured. With the recent increase in resolution (higher pixel density), even slight vibrations can have a significant impact on image quality, so the ability to suppress the capture of blurred images is extremely useful.

[0061] As shown in Figures 8 and 9, the first spring 65A is positioned at the first location 60A in the shutter unit 55 where the maximum amount of vibration occurs. Because the range of motion at the first location 60A is increased, it becomes possible to more effectively dampen the maximum amount of vibration that occurs at the first location 60A. This makes it possible to more effectively avoid the worst-case scenario in which the shutter unit 55 hits the metal housing 12 and generates a large vibration due to insufficient damping at the first location 60A.

[0062] As shown in Figures 8 and 9, the second spring 65B and the third spring 65C are positioned at the second location 60B where the maximum load occurs, and at the third location 60C, which is situated between the second location 60B and the center of gravity CG. The second location 60B, where the maximum load occurs, is the point of force application, the center of gravity CG is the fulcrum, and the third location 60C, situated between the second location 60B and the center of gravity CG, is the point of application of force. By positioning the second spring 65B and the third spring 65C at the second location 60B and the third location 60C, which have this relationship, it becomes possible to more effectively dampen vibrations generated by the opening and closing of the shutter 37.

[0063] The first spring 65A to the third spring 65C are used as vibration absorbing members. Therefore, vibrations generated when the shutter 37 is opened and closed can be suppressed with an inexpensive and simple configuration.

[0064] As shown in Figure 10, the initial load IL1 of the first spring 65A is greater than the initial loads IL2 and IL3 of the second spring 65B and the third spring 65C. Therefore, the expansion and contraction range of the first spring 65A can be made greater than that of the second spring 65B and the third spring 65C.

[0065] Furthermore, as shown in Figure 10, the spring constants SC2 and SC3 of the second spring 65B and the third spring 65C are greater than the spring constant SC1 of the first spring 65A. Therefore, the second spring 65B and the third spring 65C can be given spring characteristics that can withstand relatively large loads. In addition, the first spring 65A can be given spring characteristics that can softly absorb vibrations.

[0066] (modified version) As an example, as shown in Figure 11, in addition to the first springs 65A to the third springs 65C, a fourth spring 65D may also be provided. The fourth spring 65D is located at the fourth location 60D. The fourth location 60D is the location between the first location 60A and the center of gravity CG of the shutter unit 55. More specifically, the fourth location 60D is the location diagonally opposite the first location 60A in the upper right, at the lower left. One end of the fourth spring 65D is attached to the fourth location 60D, and the other end is attached to the rear surface 59 of the metal housing 12 facing the fourth location 60D.

[0067] This allows for more stable support of the shutter unit 55 compared to the case where the shutter unit 55 is supported by three first springs 65A to third springs 65C. Regardless of how the imaging device 10 is positioned, such as horizontally with the base surface 19 parallel to the horizontal axis, or vertically with the base surface 19 parallel to the vertical axis, the tilt of the shutter unit 55 with respect to the YZ plane in a balanced state can be stably maintained.

[0068] [Second Embodiment] As an example, as shown in Figure 12, in the second embodiment, instead of the first springs 65A to the third springs 65C, the first ball 75A, the second ball 75B, and the third ball 75C are used as vibration absorbing members. The first ball 75A is located at the first location 60A. The second ball 75B is located at the second location 60B. The third ball 75C is located at the third location 60C.

[0069] The first ball 75A to the third ball 75C are elastic and all expand and contract in the X-axis direction, i.e., along the optical axis OA. The first ball 75A has a slightly larger diameter than the second ball 75B and the third ball 75C. Therefore, the expansion and contraction range of the first ball 75A is larger than that of the second ball 75B and the third ball 75C. Because the expansion and contraction range of the first ball 75A is larger than that of the second ball 75B and the third ball 75C, the shutter unit 55, in equilibrium state, is slightly tilted with the upper right side towards the rear (and the lower left side towards the front), just as in the first embodiment described above. The first ball 75A to the third ball 75C are examples of "vibration absorbing members" according to the technology of this disclosure. The first ball 75A is an example of the "first vibration absorbing member" according to the technology of this disclosure. The second ball 75B and the third ball 75C are examples of "other vibration absorbing members" and "balls other than the first vibration absorbing member" according to the technology of this disclosure.

[0070] As an example, as shown in Figure 13, a first housing portion 80A is formed on the rear surface 59 of the metal housing 12 facing the first location 60A, which allows the first ball 75A to roll. The first housing portion 80A is a recess composed of a first rolling surface 81A of the first ball 75A and a first peripheral wall 82A erected in the X-axis direction surrounding the first rolling surface 81A. The first rolling surface 81A is circular in shape when viewed from the rear. The first rolling surface 81A is a surface parallel to the rear surface 59 of the metal housing 12. The rear surface 59 is a surface normalized to the optical axis OA. Therefore, the first rolling surface 81A is also a surface normalized to the optical axis OA. The first ball 75A is housed in the first housing portion 80A while sandwiched between this first rolling surface 81A and the front surface 83 of the shutter unit 55. The height of the first peripheral wall 82A (the depth of the first housing section 80A) is slightly less than the radius of the first ball 75A. The first peripheral wall 82A acts as a stopper to prevent the first ball 75A from rolling indefinitely. The first rolling surface 81A may be elliptical when viewed from the rear, or it may be rectangular or other rectangular shape.

[0071] When the shutter unit 55 moves relative to the metal housing 12 due to the expansion and contraction of the first springs 58A to the third springs 58C to absorb vibrations in the plane on which the shutter 37 opens and closes, the first ball 75A rolls on the first rolling surface 81A. That is, the first ball 75A absorbs vibrations in the shutter unit 55 other than those in the plane on which the shutter 37 opens and closes, and assists the movement of the shutter unit 55 due to the expansion and contraction of the first springs 58A to the third springs 58C. Note that the housings for the second ball 75B and the third ball 75C have the same configuration as the first housing 80A, so they are not shown or described.

[0072] Thus, the vibration absorbing member of the second embodiment is an elastic first ball 75A to third ball 75C. With the first ball 75A to third ball 75C, friction with the rear surface 59 of the metal housing 12 is reduced compared to the first spring 65A to third spring 65C of the first embodiment. Reduced friction with the rear surface 59 of the metal housing 12 allows for smoother movement of the shutter unit 55 due to the expansion and contraction of the first spring 58A to third spring 58C, making it easier to deal with vibrations of the plane on which the shutter 37 opens and closes. Furthermore, reduced friction with the rear surface 59 of the metal housing 12 allows for stable maintenance of the tilt position of the shutter unit 55 with respect to the YZ plane in a balanced state, regardless of how the imaging device 10 is positioned. Furthermore, while the first spring 65A to the third spring 65C require the extra effort of attaching both ends to the first location 60A to the third location 60C and the rear surface 59 of the metal housing 12, the first ball 75A to the third ball 75C only requires housing them in the first housing section 80A, etc., making installation easy. If installation space is limited, the first ball 75A to the third ball 75C are more advantageous because they can be installed easily.

[0073] The first ball 75A has a larger diameter than the second ball 75B and the third ball 75C. Therefore, as in the first embodiment described above, the shutter unit 55 in the equilibrium state can be tilted slightly with respect to the YZ plane in advance to match the vibration characteristics associated with the opening and closing of the shutter 37. Consequently, it becomes possible to more effectively dampen vibrations generated when the shutter 37 opens and closes. This effect effectively prevents the blur correction unit 35 from malfunctioning due to vibrations generated when the shutter 37 opens and closes, resulting in blurred images being captured.

[0074] The first ball 75A to the third ball 75C roll on the first rolling surface 81A, which is a plane normalized to the optical axis OA. This allows for smooth movement of the shutter unit 55 due to the expansion and contraction of the first spring 58A to the third spring 58C, and makes it easy to cope with vibrations of the plane on which the shutter 37 opens and closes.

[0075] Similar to the modification of the first embodiment described above, a fourth ball may be placed at the fourth location 60D. Alternatively, both springs and balls may be used, such as placing a first ball 75A at the first location 60A and a second spring 65B and a third spring 65C at the second location 60B and the third location 60C.

[0076] (modified version) As described above, the first balls 75A to the third balls 75C reduce friction with the rear surface 59 of the metal housing 12, allowing the shutter unit 55 to move smoothly due to the expansion and contraction of the first springs 58A to the third springs 58C. However, if the friction with the rear surface 59 of the metal housing 12 is small, the damping time until the vibration associated with the opening and closing of the shutter 37 subsides and returns to an equilibrium state will be prolonged. Therefore, as an example, as shown in Figure 14, a cushion 85 that dampens vibrations associated with the opening and closing of the shutter 37 may be placed in the hollow portion of the first springs 58A to the third springs 58C (only the first spring 58A is shown as a representative in Figure 14). The cushion 85 is, for example, a cylindrical sponge made of polyurethane, with one end attached to the metal housing 12 and the other end attached to the shutter unit 55. The cushion 85 is an example of a "vibration damping member" according to the technology of this disclosure. In this way, it is possible to prevent the damping time from being prolonged due to the small friction with the rear surface 59 of the metal housing 12.

[0077] Furthermore, the cushion 85 may be made of rubber. Also, the cushion 85 does not have to be placed in the hollow portion of the first spring 58A to the third spring 58C. In other words, the cushion 85 may be placed in a location other than the first spring 58A to the third spring 58C. Moreover, the first spring 58A to the third spring 58C may be omitted and only the cushion 85 may be placed. In this case, the cushion 85 will function as both a vibration damping member and a vibration absorbing member.

[0078] [Third Embodiment] As an example, as shown in Figure 15, in the third embodiment, a weight 90 is attached near the center of the left side of the shutter unit 55. The area near the center of the left side of the shutter unit 55 is opposite to the area near the center of the right side where the center of gravity CG of the shutter unit 55 is located when the weight 90 is not attached. The weight 90 is, for example, made of laminated high-density tungsten sheets. By attaching this weight 90, the center of gravity CG moves from near the center of the right side of the shutter unit 55 to near the center of the shutter unit 55 where the shutter 37 is located.

[0079] This reduces the bias of the center of gravity CG of the shutter unit 55, and also reduces the bias of vibration of the shutter unit 55 associated with the opening and closing of the shutter 37. As a result, the amount of tilt of the shutter unit 55 in the equilibrium state can be reduced. Since the shutter unit 55 in the equilibrium state is almost the same as when it is not tilted, vibration damping is easier. In addition, the difference in the amount of expansion and contraction between the first vibration absorbing member, such as the first spring 65A or the first ball 75A, and other vibration absorbing members, such as the second spring 65B or the second ball 75B, can be reduced. Therefore, the characteristics of the first vibration absorbing member and other vibration absorbing members do not differ too much. Furthermore, this is effective when it is not possible to increase the amount of tilt of the shutter unit 55 in the equilibrium state due to space constraints.

[0080] Note that the first springs 58A to the third springs 58C and the first springs 65A to the third springs 65C are not limited to compression springs. For example, a tension spring 95 shown in Figure 16 may be used. The tension spring 95 is suitable when it is desired to press the shutter unit 55 forward (towards the metal housing 12) according to the vibration characteristics associated with the opening and closing of the shutter 37.

[0081] The tension spring 95 has a spring body 96 and a pair of hooks 97 connected to both ends of the spring body 96. The hooks 97 are slightly larger in diameter than the spring body 96. The member 98 to which the tension spring 95 is attached (only one member 98 is shown in Figure 16) has through holes 99 through which the hooks 97 pass. The member 98 is a metal housing 12 or a shutter unit 55. The through holes 99 are larger in diameter than the spring body 96 and smaller in diameter than the hooks 97.

[0082] When attaching the tension spring 95 to the member 98, the hook 97 is pulled out through the through hole 99 using a lead wire or the like. With this configuration, the tension spring 95 can be easily positioned even when the installation space is narrow. In addition, the stability of the tension spring 95 on the member 98 can be increased. Furthermore, to further increase the stability of the tension spring 95 on the member 98, a groove matching the shape of the hook 97 may be provided on the surface of the member 98, and the hook 97 may be fitted into the groove.

[0083] Furthermore, vibration absorbing members that absorb vibrations from planes other than the plane through which the shutter 37 opens and closes may be provided at five or more locations, in addition to the three and four locations exemplified. Similarly, vibration absorbing members that absorb vibrations from the plane through which the shutter 37 opens and closes may include one or more additional springs, in addition to the three first springs 58A to the third springs 58C exemplified.

[0084] The direction in which the first spring 65A or the first ball 75A, etc., expand and contract, "along the optical axis OA," is not limited to the direction that coincides with the optical axis OA. It may also be in a direction that is tilted by a few degrees relative to the optical axis OA.

[0085] The vibration-absorbing member is not limited to the example first spring 65A, first ball 75A, etc. Cushions, magnetic springs, etc., may also be used.

[0086] The image stabilization unit 35 may move an image stabilization lens positioned on the imaging lens 14 in response to camera shake.

[0087] The imaging device relating to the technology disclosed herein may be a mirrorless interchangeable-lens digital camera, a compact digital camera, a video camera, a surveillance camera, a smartphone, or a tablet device.

[0088] From the above description, the technology described in the following supplementary information can be understood.

[0089] [Additional note 1] A shutter unit having a shutter that opens and closes in a direction intersecting the optical axis, At least three vibration absorbing members are arranged in at least three locations on the shutter unit and extend and retract in a direction along the optical axis to absorb vibrations generated when the shutter opens and closes, Equipped with, The first vibration absorbing member, which is one of the three vibration absorbing members, has a larger expansion and contraction range than the other vibration absorbing members. Imaging device. [Additional note 2] The imaging apparatus according to Appendix 1, wherein the first vibration absorbing member is located at a first location in the shutter unit where the maximum amount of vibration occurs. [Additional note 3] The imaging apparatus according to Appendix 1 or Appendix 2, wherein two of the three locations are a second location where the maximum load is generated and a third location that is sandwiched between the second location and the center of gravity of the shutter unit. [Additional note 4] The imaging apparatus according to any one of the appendix items 1 to 3, wherein the vibration absorbing members are arranged in four or more locations on the shutter unit. [Additional note 5] The imaging device according to any one of the appendix items 1 to 4, wherein the vibration absorbing member is a spring. [Additional note 6] The imaging apparatus according to Appendix 5, wherein the spring of the first vibration absorbing member has a larger initial load than the springs other than the first vibration absorbing member. [Additional note 7] Of the three locations mentioned above, two are the second location where the maximum load occurs and the third location which is situated between the second location and the center of gravity of the shutter unit. The imaging apparatus according to Appendix 5 or Appendix 6, wherein the springs located at the second and third locations have a spring constant greater than that of the other springs located at the second and third locations. [Additional note 8] The imaging device according to any one of the appendices 1 to 7, wherein the vibration absorbing member is an elastic ball. [Additional note 9] The imaging device according to Appendix 8, wherein the ball of the first vibration absorbing member has a larger diameter than the balls other than the first vibration absorbing member. [Additional Note 10] The imaging apparatus according to Appendix 8 or Appendix 9, wherein the ball rolls along a plane normal to the optical axis. [Additional Note 11] The imaging apparatus according to any one of the appendices 8 to 10, wherein the shutter unit is provided with a vibration damping member that dampens vibrations of a plane normalized to the optical axis. [Additional Note 12] The imaging apparatus according to any one of the appendices 1 to 11, wherein the shutter unit is fitted with a weight for changing the position of the center of gravity.

[0090] The technology disclosed herein can be appropriately combined with the various embodiments and / or variations described above. Furthermore, it is understood that various configurations can be adopted without departing from the spirit of the invention, and are not limited to the embodiments described above.

[0091] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0092] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."

[0093] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference. [Explanation of Symbols]

[0094] 10 Imaging device 11. Main unit of the device 12 Metal casing 13 Front 14 imaging lens 15 Back 16 LCD monitors 17 Top surface 18. Power switch integrated release button (release button) 19. Base 20 Image sensors 21 Imaging surface 25 Objective lens 26 Focus Lens 27 Zoom Lens 28 Focus lens drive mechanism 29. Zoom lens drive mechanism 30 aperture 31 Aperture opening adjustment mechanism 32 Control Unit 33 Operation section 34 Image sensor driver 35 Image stabilization unit 36 Image stabilization driver 37 Shutter 38 Shutter drive mechanism 40 Image Input Controller 41 Image memory 42 Image Processing Unit 43 Bus Line 44 VRAM 45 Display Control Unit 46 Media Controllers 47 Instruction Reception Department 48 memory cards 49 Touch panel 50 Angular velocity sensor 55 Shutter Unit 56 Motor 57 Charge Lever 58A, 58B, 58C: First spring, second spring, third spring 59. The rear surface of the metal casing. 60A, 60B, 60C, 60D: Location 1, Location 2, Location 3, Location 4 65A, 65B, 65C, 65D: 1st spring, 2nd spring, 3rd spring, 4th spring 70 tables 75A, 75B, 75C: 1st ball, 2nd ball, 3rd ball 80A First Accommodation Section 81A First rolling surface 82A 1st peripheral wall 83 Front side of the shutter unit 85 Cushions 90 weights 95 tension spring 96 Spring body 97 Hooks 98 components 99 Through holes CG center of gravity IL1 Initial load of the first spring IL2 Initial load of the second spring IL3 Initial load of the third spring Load around the LA Y axis LB Load around the Z axis OA optical axis SC1 Spring constant of the first spring SC2 Second spring spring constant SC3 Third spring constant

Claims

1. A shutter unit having a shutter that opens and closes in a direction intersecting the optical axis, At least three vibration absorbing members are arranged in at least three locations on the shutter unit and extend and retract in a direction along the optical axis to absorb vibrations generated when the shutter opens and closes, Equipped with, The first vibration absorbing member, which is one of the three vibration absorbing members, has a larger expansion and contraction range than the other vibration absorbing members. Imaging device.

2. The imaging apparatus according to claim 1, wherein the first vibration absorbing member is positioned at a first location in the shutter unit where the maximum amount of vibration occurs.

3. The imaging apparatus according to claim 1, wherein two of the at least three locations are a second location where the maximum load is generated and a third location that is sandwiched between the second location and the center of gravity of the shutter unit.

4. The imaging apparatus according to claim 1, wherein the vibration absorbing members are arranged in four or more locations on the shutter unit.

5. The imaging apparatus according to claim 1, wherein the vibration absorbing member is a spring.

6. The imaging apparatus according to claim 5, wherein the spring of the first vibration absorbing member has a larger initial load than the springs other than the first vibration absorbing member.

7. Of the three locations mentioned above, two are the second location where the maximum load occurs and the third location which is situated between the second location and the center of gravity of the shutter unit. The imaging apparatus according to claim 5, wherein the springs located at the second and third locations have a greater spring constant than the springs other than those located at the second and third locations.

8. The imaging apparatus according to claim 1, wherein the vibration absorbing member is an elastic ball.

9. The imaging apparatus according to claim 8, wherein the ball of the first vibration absorbing member has a larger diameter than the balls other than the first vibration absorbing member.

10. The imaging apparatus according to claim 8, wherein the ball rolls along a plane whose normality is the optical axis.

11. The imaging apparatus according to claim 8, wherein the shutter unit is provided with a vibration damping member that dampens vibrations of a plane normalized to the optical axis.

12. The imaging apparatus according to claim 1, wherein a weight for changing the position of the center of gravity is attached to the shutter unit.

Images