Lens barrel and imaging device

Abstract

To provide a lens barrel and an imaging device which can be made thinner.SOLUTION: The present invention relate to a lens barrel 1, which can be attached to and removed from a camera body. The lens barrel includes: a lens (L3) movable in the direction of an optical axis O1; a mounting unit 2 having a surface 2a in contact with the camera body; and a driving unit 20 having at least a part arranged in the inner diameter side than the surface 2a of the mounting unit 2, the driving unit driving the lens (L3).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lens barrel and an imaging device equipped with the same. [Background technology]

[0002] Conventionally, the lens barrel of a digital single-lens reflex camera or the like includes a plurality of lens units, an aperture unit, a motor, a sensor, and other components (see, for example, Patent Document 1).

[0003] There is a demand for smaller and thinner lens barrels. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-132580 A Summary of the Invention

[0005] The lens barrel of the first aspect is a lens barrel that is detachable from a camera body, and includes a lens that is movable in an optical axis direction, a mount portion having a contact surface that contacts the camera body, and the mount portion a lens barrel and a camera body mounted on the camera body, the lens barrel and the camera body being ... The composition was as follows. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing a lens barrel according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a lens barrel according to an embodiment. [Diagram 3] FIG. 2 is a rear view showing the lens barrel according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A lens barrel and an imaging device according to an embodiment will be described below with reference to FIGS. 1 to 3. FIG.

[0008] In this embodiment, the lens barrel is described as being a lens barrel of an imaging device such as a digital single-lens reflex camera, but the lens barrel can also be applied to the lens barrels of other imaging devices such as digital still cameras and digital video cameras. In addition, in this embodiment, the subject side is the front side in the direction of the optical axis O1, and the imaging side / image plane side of the camera body 100 is the rear side in the direction of the optical axis O1.

[0009] 1 and 2, camera A, which is an imaging device of this embodiment, includes a camera body 100 and a lens barrel 1 that is detachable from the camera body 100. The lens barrel 1 is mechanically connected to the camera body 100 via a mount section 2, and is electrically connected through contacts (terminals, connectors) 9 provided on the mount section 2, and is supplied with power from the camera body 100. A communication unit is connected to the contacts 9, and communication is performed between the lens barrel 1 and the camera body via the contacts 9.

[0010] The camera body 100 includes, for example, an imaging element such as a CCD that captures a subject image through the lens barrel 1, an AF circuit for performing focusing operations, a camera CPU that controls the operation of camera A, and a microprocessor having memory for storing various data.

[0011] As shown in Figures 1 and 2, the lens barrel 1 of this embodiment includes an approximately annular mount section 2 that is provided on the rear side of the lens barrel 1 in the direction of the axis O1 (direction of the optical axis O1) and is for connecting to a camera body 100, a fixed barrel 3 that is provided with its rear end connected (fixed, held) to the mount section 2, a zoom ring 4 that is provided on the radial outside (outer periphery side) of the fixed barrel 3 and is rotatable around the axis O1 at a predetermined angle (zoom rotation angle), a first movable barrel 5 that is provided on the radial inside (inner periphery side) of the fixed barrel 3 and is movable back and forth in the direction of the axis O1, and a second movable barrel 6 that is provided on the radial inside of the first movable barrel 5 and is movable back and forth in the direction of the axis O1.

[0012] The zoom ring 4 has a cam groove 7 on its inner peripheral surface. The fixed barrel 3 has a linear guide groove extending in the direction of the axis O1. The first movable barrel 5 and the second movable barrel 6 each have a cam follower 8 that protrudes radially on their outer peripheral surfaces.

[0013] The first movable barrel 5 and the second movable barrel 6 are arranged by engaging the cam follower 8 with the cam groove 7 through the linear guide groove, so that the first movable barrel 5 and the second movable barrel 6 are each configured to move forward and backward in the direction of the axis O1 in response to the forward and reverse rotation of the zoom ring 4 about the axis O1.

[0014] On the other hand, the lens barrel 1 of this embodiment is equipped with four lens units, namely, a first lens unit L1, a second lens unit L2, a third lens unit L3, and a fourth lens unit L4, in order from the subject side on the front side in the direction of the axis O1, and an aperture unit 10. In FIG. 1, reference numeral 15 denotes a lens hood and the like.

[0015] The lens of the first lens unit L1 is held by a first lens holding frame 14. The first lens holding frame 14 is connected and fixed to the tip side of the first moving barrel 5. As a result, the first lens unit L1 and the first lens holding frame 14 are disposed on the front side of the lens barrel 1 in the direction of the axis O1, and move forward and backward together with the first moving barrel 5 in the direction of the axis O1.

[0016] The second lens unit L2 has a lens held by the second lens holding frame 16, the third lens unit L3 has a lens held by the third lens holding frame 17, and the fourth lens unit L4 has a lens held by the fourth lens holding frame 18. The second lens holding frame 16 is directly connected and fixed to the second moving barrel 6, and the third lens holding frame 17 is indirectly connected to the second moving barrel 6 via a drive unit 20. The fourth lens holding frame 18 is connected to the second lens holding frame 16. The second, third, and fourth lens units L2 to L4 are arranged in order toward the rear side (image side) in the direction of the axis O1 of the lens units. In FIG. 2, the second lens holding frame 16 is shown as being integrated with the second moving barrel 6 and is omitted.

[0017] Here, the third lens unit L3 is provided so as to be movable by a drive unit 20 toward and away from the first lens unit L1, the second lens unit L2, and the fourth lens unit L3 in the direction of the axis O1.

[0018] The drive unit 20 includes a stepping motor 21 of the power unit, and a lead screw 22 of a feed screw unit that is connected to the rotor of the stepping motor 21 and is provided so as to be aligned with the axis O1 and axis O2 directions of the lens barrel 1, and the lead screw 22 is provided to mesh with a rack 23 attached to the third lens holding frame 17. The lead screw 22 is a feed screw unit that is provided so as to be aligned with the axis O2, and the direction of the axis O2 is approximately the same as the direction of the axis O1. As a result, the lead screw 22 is rotated forward and backward around the axis O2 by the drive of the stepping motor 21, and the third lens holding frame 17 and the third lens unit L3 can be moved relatively forward and backward in the direction of the axis O1.

[0019] In addition, the third lens retaining frame 17 has one end on the forward side in the direction of axis O1 connected to the second movable cylinder 6, and is supported and guided so as to be movable back and forth in the direction of axis O1 by a pair of guide shafts 24, 25 of a main guide bar and a sub guide bar extended rearward along the direction of axis O1.

[0020] The stepping motor 21 is connected to a motor drive circuit (not shown). The motor drive circuit is controlled by a lens CPU of a microprocessor, and drives the stepping motor 21 based on a control signal from the lens CPU. The number of drive pulses to be applied to the stepping motor 21 is stored in advance in a memory, and a predetermined number of drive pulses are applied to control the drive of the stepping motor 21.

[0021] The stepping motor 21 is controlled by an open loop control method. That is, when the camera body 100 is powered on, the lens CPU drives and controls the stepping motor 21 through a motor drive circuit to move the third lens holding frame 17 and the third lens unit L3 to a predetermined reference position (initial position / initial attitude: state in FIG. 2). A so-called initial operation (focus reset operation) is performed.

[0022] Furthermore, a reference position detection sensor (detection unit, not shown) that detects that the third lens holding frame 17 and the third lens unit L3 have moved to a predetermined reference position is provided in the lens barrel 1. The reference position detection sensor is, for example, a photointerrupter, and detects that the third lens holding frame 17 and the third lens unit L3 have moved to the predetermined reference position when a light-shielding portion enters between a light-emitting portion and a light-receiving portion of the photointerrupter, switching the state from a light-receiving state to a light-shielding state.

[0023] When a user issues a focus drive command (manual focus) or performs an AF (autofocus) operation, the lens CPU calculates the number of pulses of a drive pulse signal to be applied to the stepping motor 21, and applies the drive pulse signal to the stepping motor 21 through a motor drive circuit. This controls the drive by an open loop control method, and the third lens holding frame 17 and the third lens unit L3 move in the optical axis direction. Furthermore, when the user operates the zoom ring 4, the lens CPU may also control the stepping motor 21 to move the third lens holding frame 17 and the third lens unit L3, thereby enabling zoom tracking control.

[0024] The aperture unit 10 includes an annular press plate (not shown), an annular rotating member (not shown) that rotates forward and backward around axis O1 by driving a stepping motor (not shown), a plurality of aperture blades 10a, for example nine blades, that adjust the size of the opening, i.e., the aperture, in response to the rotation of the rotating member, and an annular cam member (not shown), and is configured to adjust the size of the opening by linking the aperture blades 10a to the driving of the stepping motor.

[0025] Furthermore, as shown in Fig. 3, the lens barrel 1 of this embodiment has a sensor (detection unit) 26 such as a gyro sensor, and is equipped with an image stabilization mechanism that moves the correction lens in a direction to cancel out blur based on the detection result of the sensor 26. The image stabilization mechanism may be configured to cancel out blur by moving the lens unit. The sensor 26 for image stabilization is not limited to a gyro sensor, and may be an acceleration sensor or the like.

[0026] On the other hand, in the lens barrel 1 of this embodiment, as shown in FIG. 2 and FIG. 3, at least a part of the drive unit 20 is disposed radially inward (inner diameter side, inner circumference side) from the surface (mount reference surface) 2a of the mount unit 2 that contacts the camera body 100 and is centered on the optical axis / axis O1. In FIG. 2 and FIG. 3, the stepping motor 21 of the drive unit 20 is disposed radially inward from the surface 2a of the mount unit 2 and centered on the optical axis / axis O1. In other words, the drive unit 20 may be provided so that at least a part of it overlaps with the mount unit 2 in the radial direction centered on the optical axis / axis O1. In addition, the surface 2a is an annular surface, and is a reference surface that contacts each other when the lens barrel 1 and the camera body 100 are attached. In addition, the fixed barrel 3 and the mount unit 2 are connected via the surface 2a. For example, when the fixed barrel 3 and the mount unit 2 are connected by a screw, a hole through which the screw passes is provided in the mount unit 2a.

[0027] Furthermore, in the lens barrel 1 of this embodiment, when attached to the camera body 100, the stepping motor 21 of the power unit is disposed closer to the image surface than the lead screw 22. At this time, one end 21a of the stepping motor 21 on the image surface side in the optical axis / axis O1 direction, i.e., one end 21a of the stepping motor 21 on the rear side in the axis O1 direction, is disposed closer to the image surface than one end 2b of the mount unit 2 on the subject side in the optical axis / axis O1 direction, i.e., one end 2b of the mount unit 2 on the front side in the axis O1 direction.

[0028] In other words, in this embodiment, the focusing stepping motor 21 is housed in a space H that includes the inner side and the image surface side of the surface 2a of the mount section 2, and is disposed radially between the fourth lens unit L4 and the mount section 2 (mount surface 2a).

[0029] In addition, instead of the stepping motor 21 for focusing, various motors for zooming and diaphragm, various sensors (26), a reference position detection sensor, and built-in components may be provided radially inward from the center of the optical axis / axis O1 beyond the mount surface 2a of the mount section 2, or on the image surface side beyond the one end 2b of the mount section 2 on the subject side in the optical axis / axis O1 direction.

[0030] As a result, with the lens barrel 1 of this embodiment, compared to conventional devices, it is possible to achieve smaller and thinner lens barrel 1 by shortening the length of the lens barrel 1 in the direction of the optical axis / axis O1 (reducing the size) and reducing the diameter dimension at the center of the optical axis / axis O1 (reducing the size and thickness).

[0031] Furthermore, since the stepping motor 21 of the drive unit 20 is disposed closer to the image surface side than the lead screw 22, a large range of movement of the third lens unit L3 can be ensured. This also makes it possible to improve the performance of the lens barrel 1.

[0032] In the lens barrel 1 of this embodiment, by configuring as described above, the position of the rack 23 can be brought closer to the center of gravity of the imaging device A, and a highly stable lens barrel 1 and imaging device A can be realized. Furthermore, by accommodating various sensors (26) and the like in the space H, the lens group can be arranged on the image surface side from the mount surface 2a of the mount unit 2 in the radial direction of the optical axis / axis O1 center or from the one end 2b of the mount unit 2 on the subject side in the optical axis / axis O1 direction, the lens group can be arranged on the image surface side. This allows the sensor 26 and the motor 21 to be arranged using the space H, and the lens group can be arranged on the image surface side compared to the conventional case, so that the center of gravity can be decentered further backward, and a more stable lens barrel 1 and imaging device A can be realized.

[0033] In this case, by locating the sensor 26 for image stabilization radially inward from the mount surface 2a of the mount portion 2 or on the image plane side from the end 2b of the mount portion 2 on the subject side, it is possible to achieve detection performance and image stabilization performance that are more accurate and reliable.

[0034] Furthermore, by locating the rack 23 closer to the center of gravity, it is possible to achieve measures against noise, impact, and vibration.

[0035] Even if the diameter of the mount section 2 is increased, the focusing stepping motor 21 can be accommodated in the space H that protrudes rearward from the surface 2a of the mount section 2 and disposed radially between the lens of the fourth lens unit L4 and the mount section 2, thereby making it possible to achieve a smaller and thinner structure.

[0036] For example, even in a lens barrel 1 in which the shooting angle of view G shown in FIG. 3 is small, or in a lens barrel 1 in which an operating ring (e.g., a zoom ring, focus ring, aperture ring, control ring, etc.) that is operated by the user is located on the radially outer portion of the mount section 2, the stepping motor 21, etc. can be housed in space H that includes the rear / inner side of surface 2a of the mount section 2, and disposed radially between the lens of the fourth lens unit L4 and the mount surface 2a of the mount section 2, thereby effectively achieving miniaturization and thinning.

[0037] The lens barrel 1 of this embodiment is provided with a protrusion 27 such as a bayonet claw that protrudes radially outward from the mount portion 2, and the stepping motor 21 of the drive portion 20 and the protrusion 27 are arranged at different positions in the circumferential direction centered on the optical axis / axis O1.

[0038] As a result, when the lens barrel 1 is subjected to an impact, such as when the camera A is dropped, the stepping motor 21 is separated from the protruding portion 27 (the connection portion with the camera body 100) such as a bayonet claw, thereby preventing a large impact force from acting on the stepping motor 21. In other words, even when the space H is formed so as to protrude rearward or toward the inner periphery from the mount surface 2a as in this embodiment, it is possible to effectively prevent a large impact force from acting on the stepping motor 21 housed in this space H.

[0039] In the lens barrel 1 of this embodiment, the drive unit 20 is disposed in a position corresponding to the long side of the image sensor of the camera body 100 in the circumferential direction centered on the optical axis / axis O1. In this embodiment, the drive unit 20 is disposed outside the long side of the photographing angle of view (optical path) G. This makes it possible to make the lens barrel 1 smaller and thinner without interfering with the image surface.

[0040] Furthermore, the drive portion 20 is disposed at a position different from the contact point 9 in the circumferential direction centered on the optical axis / axis O1. This makes it possible to prevent noise from the stepping motor 21 from affecting the contact 9. Therefore, it becomes possible to make the lens barrel 1 smaller and thinner without affecting the power supply and communications, especially communications.

[0041] Also, as shown in FIG. 2, in the initial posture of the lens barrel 1 of this embodiment, the image surface side end 28 of the guide axes 24, 25 in the direction of the optical axis / axis O1 is arranged closer to the image surface than the subject side end 2b of the mount section 2 in the direction of the optical axis / axis O1.

[0042] This allows the second movable barrel 6 and the third lens unit L3 to be moved (retracted) farther rearward toward the image plane than in the past, making it possible to more effectively reduce the size and also improve the performance of the lens barrel 1.

[0043] The above describes one embodiment of the lens barrel and imaging device, but the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the invention, and any combination is also possible. [Explanation of symbols]

[0044] 1 Lens barrel 2 Mounting section 2a surface (mount surface) 2b one end 3 Fixed barrel 4 Zoom Ring 5. First moving cylinder 6. Second moving cylinder 7 Cam groove 8 Cam Follower 9 Contacts 10 Aperture unit 10a aperture blades 14 First lens holder 15 Lens hood 16 Second lens holder 17 Third lens holder 18 Fourth lens holder 20 Drive unit 21 Stepping motor (power unit) 22 Lead screw (feed screw part) 23 Rack 24 Guide shaft (main guide bar) 25 Guide shaft (sub-guide bar) 26 Sensor (detection part) 27 Protruding part (bayonet claw) 28 One end of the guide shaft 100 Camera Body A Camera (imaging device) G Shooting angle, optical path H space L1 First lens unit L2 Second lens unit L3 Third lens unit L4 4th lens unit O1 Optical axis, axis of lens barrel O2 Lead screw axis

Claims

1. A lens barrel that is detachable from a camera body, A lens movable in the direction of an optical axis; a mount portion having a contact surface that comes into contact with the camera body; a plurality of protrusions protruding outward from the mount portion and extending in a circumferential direction centered on the optical axis; a drive unit that drives the lens, the drive unit being disposed radially inward of the contact surface of the mount unit and disposed at a position different from the protrusion in a circumferential direction about the optical axis; a guide member for guiding the lens in an optical axis direction; the contact surface is a reference surface where the lens barrel and the camera body come into contact with each other when they are attached to each other, and is a surface perpendicular to the optical axis direction; At least a portion of the guide member and at least a portion of the drive portion intersect with the contact surface. Lens barrel.

2. In a radial direction centered on an optical axis, the mount section and the drive section at least partially overlap. The lens barrel according to claim 1 .

3. One end of the drive unit on the image surface side in the optical axis direction is disposed closer to the image surface than the contact surface. The lens barrel according to claim 1 or 2.

4. The drive unit includes a power unit and a screw unit rotated by the power unit, The power unit is disposed on the image plane side of the screw unit. The lens barrel according to any one of claims 1 to 3.

5. A lens holding frame for holding the lens, The screw portion and the lens holding frame are engaged with each other, and the lens holding frame moves in the optical axis direction by rotation of the screw portion. The lens barrel according to claim 4.

6. The engagement portion that engages the screw portion with the lens holding frame does not have a comb tooth portion. The lens barrel according to claim 5 .

7. A protrusion protruding in an outer diameter direction from the mount portion, The driving portion and the protruding portion are disposed at different positions in a circumferential direction about the optical axis. The lens barrel according to any one of claims 1 to 6.

8. The drive unit is disposed at a position corresponding to a long side of an image sensor of the camera body in a circumferential direction centered on the optical axis. The lens barrel according to any one of claims 1 to 7.

9. A plurality of contacts capable of communicating with the camera body; The driving portion is disposed at a position different from the contact point in a circumferential direction about the optical axis. The lens barrel according to any one of claims 1 to 8.

10. On the contact surface, the contact point and the drive unit are disposed in opposing positions across the optical axis. The lens barrel according to claim 9.

11. One end of the guide member on the image side in the optical axis direction is disposed closer to the image side than one end of the mount part on the subject side in the optical axis direction. The lens barrel according to any one of claims 1 to 10.

12. A detection unit for detecting the position of the lens, At least a portion of the detection portion is disposed radially inward from the contact surface of the mount portion. The lens barrel according to any one of claims 1 to 11.

13. A lens barrel as described in any one of claims 1 to 12, wherein when the lens is moved closest to the image surface, the image surface is positioned closer to the object side than the contact surface.

14. A plurality of lenses including the lens, The driving unit is disposed between at least one of the lenses and the contact surface in a radial direction about an optical axis. The lens barrel according to any one of claims 1 to 13.

15. The contact surface is annular. The lens barrel according to any one of claims 1 to 13.

16. A lens barrel as described in any one of claims 1 to 15, comprising an outer tube member arranged in contact with the outer peripheral end of the mounting portion.

17. The mount portion includes an inner tubular member disposed in contact with an end portion of an inner periphery of the contact surface and extending from the contact surface toward the camera body, The lens barrel according to claim 1 , wherein at least a portion of the drive portion is disposed radially inwardly of the inner cylinder member.

18. A lens barrel as described in claim 17, comprising an image side lens arranged radially inward from the inner tube member.

Images