JP7206996B2 - Lens barrel and camera - Google Patents

Description

The present invention relates to a lens barrel and a photographing device.

As a lens barrel such as an interchangeable lens used in a single-lens reflex camera or the like equipped with an autofocus mechanism, an automatic focus adjustment means (autofocus means) and a manual focus adjustment means (manual focus means) are provided, and either one is selected without a switching means. is known. In this type of lens barrel, if the drive ring for driving the lens group for focus adjustment in the lens barrel and the manual focus adjustment means are connected, the user may inadvertently It is pointed out that if the manual focus adjustment means is operated, the drive ring will move and the lens will be displaced from the position after focus adjustment.

Therefore, for example, Patent Document 1 discloses a lens barrel that uses a differential mechanism for focus adjustment to perform automatic focus adjustment and manual focus adjustment without switching. An arrangement is described having means for blocking the transmission of force from the manual focusing means to the differential mechanism during autofocusing by moving .

Japanese Patent Laid-Open No. 2002-200000 describes a lens barrel that uses a differential mechanism for focus adjustment to allow automatic focus adjustment and manual focus adjustment without switching, and a focus operation ring for manual focus adjustment that extends in the optical axis direction. A configuration is described in which the connection between the focus operation ring and the differential mechanism can be released by moving.

JP-A-3-144412 JP-A-2000-249892

Both of the lens barrels described in Patent Documents 1 and 2 release the coupling between the manual focus adjustment means and the differential mechanism by moving a member provided on the lens barrel in the optical axis direction of the lens barrel. It has a configuration that allows With such a configuration, the user needs to move this member with one hand in the direction of the optical axis when photographing. Therefore, this movement operation tends to make the holding of the imaging device such as a camera held by the other hand unstable. In addition, the image pickup device itself and the lens barrel itself move slightly in the optical axis direction along with this movement operation, and the focal position tends to shift. In particular, this problem becomes even more conspicuous during close-up photography (macro photography) or the like, since focus adjustment tends to be severe.

The present invention has been made in view of the above circumstances, and its object is to prevent inadvertent deviation of the focal position by disabling manual focus adjustment by user's operation . An object of the present invention is to provide a more suitable lens barrel and imaging device.

A lens barrel according to an embodiment of the present invention is capable of adjusting the focus by moving the focus lens in the optical axis direction manually with an operation member or automatically with an actuator, and is interlocked with the focus lens. a first drive ring, a second drive ring interlocked with the operating member, interlocking the first drive ring and the second drive ring, and releasing interlocking between the first drive ring and the second drive ring and a possible release. The release portion presses one of the first drive ring and the second drive ring against the other so that the driving force of the second drive ring is transmitted to the first drive ring. By separating the two driving rings, the driving force of the second driving ring is not transmitted to the first driving ring.

An imaging device according to an embodiment of the present invention includes the lens barrel described above.

According to an embodiment of the present invention, a more suitable lens barrel and photographing apparatus are provided that can prevent accidental deviation of the focal position by disabling manual focus adjustment by a user's operation . .

It is a figure which shows the structure of the imaging device which concerns on 1st embodiment of this invention. It is the left side view which fracture|ruptured a part of lens-barrel with which the imaging device which concerns on 1st embodiment of this invention is equipped. 1 is a longitudinal sectional view of a lens barrel according to a first embodiment of the invention; FIG. FIG. 4 is a vertical cross-sectional view showing a configuration including a differential mechanism extracted from FIG. 3 and showing a state in which manual focus adjustment is possible; FIG. 4 is a vertical cross-sectional view showing a configuration including a differential mechanism extracted from FIG. 3 and showing a state in which manual focus adjustment is disabled; FIG. 5 is a cross-sectional view taken along line AA of FIG. 4; FIG. 4 is a perspective view of some members including an output ring of the lens barrel according to the first embodiment of the present invention; FIG. 4 is an exploded perspective view of a release mechanism included in the lens barrel according to the first embodiment of the present invention; FIG. 10 is a vertical cross-sectional view showing a part of the structure extracted from the lens barrel according to the second embodiment of the present invention, showing a state in which manual focus adjustment is possible. FIG. 10 is a vertical cross-sectional view showing a part of the structure extracted from the lens barrel according to the second embodiment of the present invention, showing a state in which manual focus adjustment is impossible; FIG. 10 is an exploded perspective view of a release mechanism included in the lens barrel according to the second embodiment of the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lens barrel and an imaging apparatus including the lens barrel according to one embodiment of the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 is a diagram showing the configuration of an imaging device IA according to the first embodiment of the present invention. As shown in FIG. 1, the photographing apparatus IA includes a lens barrel 1 and a camera body 2 to which the lens barrel 1 is attached. Although the photographing device IA is a single-lens reflex camera, it may be a compact digital camera, a mirrorless single-lens camera, a video camera, a camcorder, or any other type of photographing device having a photographing function.

FIG. 2 is a partially broken left side view of the lens barrel 1. FIG. As shown in FIG. 2, an operation ring (operation member) 76 is provided on the front side (object side) of the peripheral surface of the lens barrel 1 . The user can manually adjust the focus (manual focus) by rotating the operation ring 76 around the optical axis of the lens barrel 1 (hereinafter simply referred to as rotation). A zoom operation ring 63 is provided on the rear surface side (image plane side) of the peripheral surface of the lens barrel 1 . The user can change the focal length of the lens barrel 1 by rotating the zoom operation ring 63 .

A part of the peripheral surface of the left side surface of the lens barrel 1, and an intermediate position (in other words, between the operation ring 76 and the zoom operation ring 63) in the optical axis direction of the lens barrel 1 (hereinafter simply referred to as the optical axis direction). ), a release switch (release operation member) 85 is provided. The release switch 85 constitutes a release mechanism (release unit) 8 for disabling manual focus adjustment. The release mechanism 8 switches between a state in which manual focus adjustment by the operation ring 76 is enabled and a state in which it is disabled by the user sliding the release switch 85 along the peripheral surface of the lens barrel 1 . is configured to In the first embodiment, when the user slides the release switch 85 downward in FIG. 2, manual focus adjustment using the operation ring 76 becomes impossible, and focus adjustment is performed even if the user operates the operation ring 76. Gone. Details of the release mechanism 8 will be described later.

When the user operates the release switch 85 to disable the manual focus adjustment by the operation ring 76, the focal position can be prevented from being accidentally deviated due to the operation ring 76 being carelessly operated.

FIG. 3 is a longitudinal sectional view of the lens barrel 1. FIG. As shown in FIG. 3, within the lens barrel 1, in order from the object side, there are a first lens group L1, a second lens group L2, a third lens group L3, a fourth lens group L4, and a fifth lens group L5. are placed. At least some of the lens groups L1 to L5 move in the optical axis direction of the lens barrel 1 according to the rotation operation of the zoom operation ring 63 . As a result, the focal length of the lens barrel 1 changes. The second lens group L2 is configured as a focus lens that moves in the optical axis direction for focus adjustment during zooming and focus adjustment. Hereinafter, the "second lens group L2" will be referred to as a "focus lens L2".

A focus motor 3 is provided in the lens barrel 1 near the image plane side. The focus motor 3 is driven and controlled by an automatic focus control device (not shown) provided in the camera body 2, for example. When the focus motor 3 is driven by the automatic focus control device, the focus lens L2 moves in the optical axis direction for focus adjustment. The focus motor 3 forms part of an actuator for automatic focus adjustment. The focus motor 3 is, for example, a DC motor, but may be another motor such as a brushless DC motor, a stepping motor, an ultrasonic motor, or the like.

As described above, in the lens barrel 1 according to the first embodiment, the focus motor 3 is located closer to the image plane side, the operation ring 76 is located closer to the object side, and the release switch 85 is located between the focus motor 3 and the operation ring 76. It is arranged at an intermediate position in the optical axis direction.

Inside the lens barrel 1 are an automatic focus adjustment mechanism 4 driven by a focus motor 3, a manual focus adjustment mechanism 5 driven by an operation ring 76, and a differential mechanism that enables focus adjustment by both of these focus adjustment mechanisms. A movement mechanism 6 is provided. The differential mechanism 6 enables position adjustment of the focus lens L2 by the automatic focus adjustment mechanism 4 and enables position adjustment of the focus lens L2 by the manual focus adjustment mechanism 5. FIG. By operating the release switch 85, the user can prevent the manual focus adjustment mechanism 5 from adjusting the position of the focus lens L2 even if the operation ring 76 is operated.

The lens barrel 1 has a fixed ring 91 with a lens mount M. As shown in FIG. A fixed ring 90 is connected to the fixed ring 91 . A support ring 53 is arranged at the inner diameter position of the fixed ring 90 . A support ring 75 is arranged on the object side of the support ring 53 .

A rectilinear ring 32 and a zoom cam ring 31 are concentrically arranged in order in the radial direction at the inner diameter position of the support ring 53 . At the inner diameter position of the zoom cam ring 31, the third lens group frame 21 holding the third lens group L3, the focus cam ring 12, and the focus lens frame 11 holding the focus lens L2 are concentrically arranged. A first lens group frame 15 is arranged on the inner diameter of the zoom cam ring 31 on the object side, and a fourth lens group frame 16 and a fifth lens group frame 17 are arranged on the inner diameter of the zoom cam ring 31 on the image plane side. It is

A cam groove 31a is formed in the zoom cam ring 31 so as to extend through the inner and outer diameters thereof. A groove 32a is formed in the rectilinear ring 32 . A roller (cam follower) 21a attached to the outer periphery of the third lens group frame 21 passes through the cam groove 31a and slides into the groove 32a. This restricts the rotation of the third lens group frame 21 and allows the third lens group frame 21 to move only in the optical axis direction.

In the first embodiment, "slip fit" refers to a state in which the members are loosely fitted to each other, and one member is slidably fitted to the other member. In the above example, the roller 21a is slidably fitted in the cam groove 31a and the groove 32a.

Although detailed explanation is omitted, when the zoom operation ring 63 is manually operated by each cam mechanism provided in the lens barrel 1 including the cam groove 31a and the like to rotate the zoom cam ring 31, each lens L1 is rotated. .about.L5 moves in the direction of the optical axis, and the photographing magnification of the lens barrel 1 changes.

A circumferential groove 21 b is provided on the inner peripheral surface of the third lens group frame 21 . A plurality of balls 14 are arranged between the circumferential groove 21 b and the outer peripheral surface of the focus cam ring 12 . The focus cam ring 12 is rotatably held inside the third lens group frame 21 by a plurality of balls 14 .

The focus cam ring 12 is formed with cam grooves 12a penetrating the inner and outer diameters thereof. A groove 21 c is formed in the third lens group frame 21 . A roller 11 a is attached to the outer periphery of the focus lens frame 11 . The roller 11a passes through the cam groove 12a and slides into the groove 21c. As a result, the rotation of the focus lens frame 11 is restricted so that the focus lens frame 11 can move only in the direction of the optical axis.

A focus lever 13 extending toward the image plane in the optical axis direction is fixed to the focus cam ring 12 by a member such as a screw. The focus lever 13 rotates upon receiving the output of the differential mechanism 6, and this rotation causes the focus cam ring 12 to rotate together. The rotation of the focus cam ring 12 is transmitted to the focus lens frame 11 via the cam groove 12a and the roller 11a, and advances and retreats the focus lens frame 11 (and the focus lens L2) in the optical axis direction.

The differential mechanism 6 is arranged in a region between the rectilinear ring 32 and the fixed ring 90 and between the focus motor 3 and the operation ring 76 . 4 and 5 are longitudinal sectional views showing the configuration including the differential mechanism 6 extracted from FIG. 3. FIG. 4 shows a state in which manual focus adjustment is possible, and FIG. 5 shows a state in which manual focus adjustment is not possible. 6 is a cross-sectional view taken along the line AA of FIG. 4. FIG.

As shown in FIGS. 4 and 5, the output ring 51 is arranged on the outer diameter side of the support ring 53 . FIG. 7 is a perspective view of some members including the output ring 51. FIG.

Three rotating shafts 51a extending in the outer diameter direction (the direction perpendicular to the optical axis) are provided at equal intervals on the outer peripheral surface of the output ring 51 . A planetary roller 55 is supported on the rotating shaft 51a so as to be rotatable around the rotating shaft 51a. A lid 56 is fixed to the output ring 51 with a screw or the like. This prevents the planetary rollers 55 from coming off from the rotary shaft 51a. The planetary rollers 55 and the output ring 51 constitute the planets of the planetary mechanism and the planetary carrier, respectively.

The output ring 51 is rotatable about the optical axis with respect to the support ring 53 via a structure (for example, a bearing) not shown. The planetary rollers 55 are sandwiched between the driving gear ring (annular member) 61 and the first driving ring 71 . This restricts the movement of the output ring 51 in the optical axis direction.

An output lever 52 extending in the optical axis direction is fixed to the output ring 51 with a screw or the like. The tip of the output lever 52 slides on the focus lever 13 . When the output ring 51 rotates, the rotation is transmitted to the focus lever 13 via the output lever 52, and the focus cam ring 12 fixed to the focus lever 13 also rotates. As a result, the focus lens frame 11 (focus lens L2) advances and retreats in the optical axis direction to change the focus.

That is, the output lever 52, the focus lever 13, and the focus cam ring 12 convert the rotation of the output ring 51 about the optical axis into rectilinear motion and transmit it to the focus lens L2, thereby moving the focus lens L2 forward and backward along the optical axis. Acts as a transmission unit for

The drive gear ring 61 is rotatably held on the outer peripheral surface of the drive gear support ring 62 via a structure (for example, a bearing) not shown. Here, a first wave washer (first biasing portion) 72 biases the first drive ring 71 toward the image plane side. Due to this biasing force, the sliding surface 71 a of the first drive ring 71 is pressed against the planetary rollers 55 . The driving gear ring 61 is urged toward the image plane side via the planetary rollers 55 by the first wave washer 72 and sandwiched between the planetary rollers 55 and the end surface 62 a of the driving gear support ring 62 .

An internal gear 61b is provided at the edge of the drive gear ring 61 on the image plane side. A focus motor 3 is connected to the internal gear 61b via a gear mechanism (not shown). As a result, when the focus motor 3 rotates, the drive gear ring 61 rotates in conjunction therewith. As the drive gear ring 61 rotates, the planetary rollers 55 that press against the drive gear ring 61 rotate. Further, the output ring 51 and the focus cam ring 12 are rotated, and the focus is adjusted by the focus lens L2. The members for performing these automatic focus adjustments (various members that operate according to the rotation of the focus motor 3) constitute the automatic focus adjustment mechanism 4. FIG. Further, the drive gear ring 61 constitutes one input portion of the differential mechanism 6 .

The drive gear ring 61 is configured as an annular member that is biased by the planetary rollers 55 and interlocked with the focus motor 3 (actuator).

Two types of drive rings, a first drive ring 71 and a second drive ring 73, are rotatably held at different positions on the outer peripheral surface of the support ring 75 via structures (for example, bearings) not shown. The second drive ring 73 is biased toward the image plane side (first drive ring 71 side) by a second wave washer (second biasing portion) 74 . As a result, the end face 73a of the second drive ring 73 is brought into pressure contact with the end face 71b of the first drive ring 71 .

Rollers 73b are attached to the outer circumference of the second drive ring 73 at a plurality of locations in the circumferential direction. The roller 73b slides into a groove 76a formed in the operating ring 76. As shown in FIG. When the user operates the operation ring 76, rotation about the optical axis is transmitted to the second drive ring 73 via the roller 73b, and the first drive ring 71 pressed against the second drive ring 73 also rotates together. . Furthermore, when the planetary rollers 55 press against the sliding surface 71a, the rotation of the first drive ring 71 causes the planetary rollers 55 to rotate. The output ring 51 and the focus cam ring 12 are rotated, and focus adjustment is performed by the focus lens L2. The members for performing these manual focus adjustments (various members that operate according to the rotation of the operation ring 76) constitute the manual focus adjustment mechanism 5. FIG. Also, the first drive ring 71 and the second drive ring 73 constitute another input portion of the differential mechanism 6 .

When the focus motor 3 is driven, its driving force is transmitted to the planetary rollers 55 via the drive gear ring 61 . As a result, the planetary rollers 55 rotate around the rotation shaft 51 a of the output ring 51 . At this time, the first drive ring 71 does not rotate but remains stationary due to the friction torque generated between it and the first wave washer 72 and the friction torque generated between it and the second drive ring 73 by the second wave washer 74 . are doing. Therefore, the planetary roller 55 revolves around the optical axis of the output ring 51 while rotating around the rotation axis 51a. At this time, the output ring 51 rotates by approximately half the amount of rotation of the driving gear ring 61 .

When the operation ring 76 is operated by the user, the driving force corresponding to the operation is transmitted to the planetary rollers 55 via the second drive ring 73 and the first drive ring 71 . As a result, the planetary rollers 55 rotate around the rotation shaft 51 a of the output ring 51 . At this time, the drive gear ring 61 is stationary without rotating due to friction torque generated between it and the end surface 62 a of the drive gear support ring (another member) 62 . Therefore, the planetary roller 55 revolves around the optical axis of the output ring 51 while rotating around the rotation axis 51a.

The lens barrel 1 according to the first embodiment is provided with two independent drive rings (a first drive ring 71 and a second drive ring 73) as drive rings for manual focus adjustment. When the pressing force (biasing force) by the first wave washer 72 is F1 and the pressing force (biasing force) by the second wave washer 74 is F2, the force generated between the first drive ring 71 and the first wave washer 72 is The frictional force is μ1F1, the frictional force generated between the second drive ring 73 and the second wave washer 74 is μ2F2, and the frictional force generated between the first drive ring 71 and the second drive ring 73 is μ3F2. becomes. Note that μ1 is the coefficient of static friction between the first drive ring 71 and the first wave washer 72 . μ2 is the coefficient of static friction between the second drive ring 73 and the second wave washer 74; μ3 is the coefficient of static friction between the first drive ring 71 and the second drive ring 73;

In order for the first drive ring 71 and the second drive ring 73 to rotate integrally without slipping when the operation ring 76 is operated by the user, the following equation must be satisfied.

μ1F1<μ3F2

For example, when the static friction coefficients μ1 and μ3 are the same value, by making the pressing force F2 by the second wave washer 74 sufficiently larger than the pressing force F1 by the first wave washer 72, the first drive can be ensured. The ring 71 and the second driving ring 73 can be rotated integrally without slipping. Further, when the pressing force F1 and the pressing force F2 are substantially the same, the static friction coefficient μ3 is made sufficiently larger than the static friction coefficient μ1 (for example, the end face 73a of the second drive ring 73 has a friction coefficient By attaching and fixing a large elastic member such as rubber, the first drive ring 71 and the second drive ring 73 can be reliably rotated integrally without slipping.

In the state shown in FIG. 4, both automatic focus adjustment and manual focus adjustment are possible. Therefore, when the user operates the operation ring 76 during automatic focus adjustment, the output ring 51 rotates via the differential mechanism 6, which causes a problem that the focal position is shifted.

In order to prevent such problems from occurring, the lens barrel 1 is provided with a release mechanism 8 . The release mechanism 8 presses one of the first drive ring 71 and the second drive ring 73 against the other (in the first embodiment, the second drive ring 73 against the first drive ring 71) to release the second drive ring. By transmitting the driving force of 73 to the first driving ring 71 and by separating the first driving ring 71 and the second driving ring 73, the driving force of the second driving ring 73 is transmitted to the first driving ring. prevent it from being transmitted to 71. FIG. 8 shows an exploded perspective view of the release mechanism 8. As shown in FIG.

An annular releasing member 81 , a releasing switching ring 82 and a pressing ring 84 are arranged at the outer diameter position of the first driving ring 71 .

On the outer peripheral surface of the release member 81, three rectilinear keys 81a directed in the optical axis direction are provided at regular intervals. The rectilinear key 81a slides into a groove 90a formed in the inner peripheral surface of the stationary ring 90, and is held inside the stationary ring 90 so as to be able to rectilinearly move while being restricted from rotating about the optical axis. The release member 81 is formed with an engagement projection 81b.

The release switching ring 82 is rotatably held at the inner diameter position of the fixed ring 90 . The release switching ring 82 has a surface facing the release member 81 (that is, a surface on the object side in the optical axis direction), and a plurality of (here, six) cams 82a are formed in the circumferential direction. In the optical axis direction, the cam 82a is arranged at a position facing the engagement projection 81b formed on the release member 81. As shown in FIG.

The pressing ring 84 is fixed to the front of the fixed ring 90 with screws or the like. Compression coil springs 83 are arranged at a plurality of locations (here, six locations) in the circumferential direction between the pressing ring 84 and the release member 81 . The releasing member 81 is always urged toward the release switching ring 82 by the biasing force of the compression coil spring 83 , and the engaging projection 81 b of the releasing member 81 presses against the cam 82 a of the release switching ring 82 . A pressing rib 90 b is formed on the inner peripheral surface of the fixed ring 90 . The release switching ring 82 is held between the release member 81 and the pressing rib 90b by being biased by the release member 81. As shown in FIG.

The release switch 85 is attached to a release switch attachment member 86 . A brush 87 and a leaf spring 88 are also attached to the release switch attachment member 86 .

The release switching ring 82 is formed with an engagement key 82b extending rearward. The engagement key 82b is engaged with the engagement groove 86a of the release switch mounting member 86. As shown in FIG. Thereby, the release switching ring 82 is in a state of being connected with the release switch 85 . When the release switch 85 is moved in the circumferential direction by the user's operation, the release switching ring 82 rotates around the optical axis in conjunction with this movement.

The leaf spring 88 is for transmitting switching of the switch when the user operates the release switch 85 . When the user operates the release switch 85 , the bent portion 88 a formed at the tip of the leaf spring 88 enters into the valley portion 90 c or 90 d formed on the inner peripheral surface of the fixed ring 90 . The click feeling generated at this time informs the user that the release switch 85 has switched (that the focus has been switched to a state in which manual focus adjustment is possible or impossible).

FIG. 6 shows a state in which manual focus adjustment is possible. That is, when the bent portion 88a is positioned at the valley portion 90c, manual focus adjustment is possible. When the release switch 85 is operated until the bent portion 88a reaches the position of the valley portion 90d, manual focus adjustment becomes impossible.

The operation of the release mechanism 8 will be described.

FIG. 4 shows a state in which manual focus adjustment is possible. The release member 81 has a surface facing the second drive ring 73, and a rib 81c protruding toward the second drive ring 73 is formed over the entire circumference. Rib 81c is in contact with second drive ring 73 when release switch 85 is in a position that disables manual focus adjustment. Hereinafter, for the sake of convenience, the position of the release switch 85 when manual focus adjustment is disabled is referred to as the "release position", and the position of the release switch 85 when manual focus adjustment is enabled is referred to as the "connection position." Write down.

The brush 87 is electrically connected to a flexible printed circuit board (not shown) arranged inside the lens barrel 1 . The position of the release switch 85 can be detected by a brush 87 .

When the release switch 85 is operated from the release position to the connection position, the release switching ring 82 is rotated from the position where the cam 82a is pressed against the engagement projection 81b to the position where the cam 82a does not contact the engagement projection 81b. be. As a result, the release member 81 is moved toward the image plane side by the biasing force of the compression coil spring 83 , and the rib 81 c is separated from the second drive ring 73 .

When the rib 81 c is separated from the second drive ring 73 , the biasing force of the second wave washer 74 presses the end face 73 a of the second drive ring 73 against the end face 71 b of the first drive ring 71 . Further, the sliding surface 71 a of the first driving ring 71 urged toward the image plane by the first wave washer 72 is in pressure contact with the planetary rollers 55 . Therefore, when the user operates the operation ring 76, the driving force corresponding to the operation is transmitted to the planetary rollers 55 via the second drive ring 73 and the first drive ring 71, and the output ring 51 and the focus cam ring 12 rotate. Then, focus adjustment is performed by the focus lens L2.

FIG. 5 shows a state in which manual focus adjustment is disabled.

When the release switch 85 is operated from the connection position to the release position (when the release switch 85 is operated in the direction of the arrow in FIG. 8), the release switching ring 82 interlocks with the movement of the release switch 85, and the cam 82a It is rotated to a position where it presses against the engaging projection 81b. As a result, the releasing member 81 is moved toward the object side against the biasing force of the compression coil spring 83 . The rib 81c of the release member 81 contacts the second drive ring 73, and pushes the second drive ring 73 toward the object against the biasing force of the second wave washer 74 to move it. As a result, as shown in FIG. 5, a gap is generated between the end face 73a of the second drive ring 73 and the end face 71b of the first drive ring 71, and the gap between the second drive ring 73 and the first drive ring 71 is caused. Disconnected.

Since the rollers 73b of the second drive ring 73 are slid into the grooves 76a of the operation ring 76, when the user operates the operation ring 76, the driving force corresponding to the operation is transmitted to the second drive ring 73, The second drive ring 73 rotates. However, since the second driving ring 73 is separated from the first driving ring 71, the driving force corresponding to the operation of the operating ring 76 is not transmitted to the first driving ring 71, and the first driving ring 71 does not rotate. . Therefore, even if the user operates the operation ring 76, the output ring 51 and the focus cam ring 12 do not rotate, and focus adjustment by the focus lens L2 is not performed.

That is, the releasing member 81 is switched between the first position (the position of the releasing member 81 when the cam 82a is pressed against the engaging projection 81b) and the second position by moving the release switch 85 by the user. Position (the position of the releasing member 81 when the cam 82a is not pressed against the engaging projection 81b) is configured as a moving member that alternatively moves. When the release member 81 moves to the first position, it pushes the second drive ring 73 against the urging force of the second wave washer 74 to separate it from the first drive ring 71. When it moves to the second position, the release member 81 moves to the second position. Separated from the second drive ring 73 , the second drive ring 73 is pressed against the first drive ring 71 by the biasing force of the second wave washer 74 .

When the brush 87 detects that the release switch 85 has been operated to the release position, a control circuit (not shown) provided in the camera body 2 cuts off the power supply to the focus motor 3 to automatically adjust the focus. may be prohibited.

In this manner, the lens barrel 1 is configured to enable or disable manual focus adjustment using the operation ring 76 by operating the release switch 85 in the circumferential direction of the lens barrel 1 . Therefore, compared to the configuration of Patent Document 1 and Patent Document 2, in which a member that disables manual focus adjustment is operated in the optical axis direction of the lens barrel, operability during imaging is improved, and operation during operation is improved. The holding of the imaging device IA is stabilized.

Also, the relatively heavy focus motor 3 is provided in the lens barrel 1 near the image plane side, and the release switch 85 is positioned closer to the object than the focus motor 3 and closer to the image plane than the operation ring 76 ( Since it is provided in the middle position of the optical axis direction of the lens barrel 1, the moment generated in the lens barrel 1 when the release switch 85 is operated is small, and the optical axis direction of the lens barrel 1 can be easily maintained. There is

Also, the release member 81 pushes the second drive ring 73 to release the connection between the second drive ring 73 and the first drive ring 71 . Therefore, the release switch 85 can be operated at an arbitrary position regardless of the rotational position of the operating ring 76, and deviation of the focal position due to minute rotation of the operating ring 76 can be prevented. Furthermore, since there is no influence of backlash caused by part tolerance, deviation of the focus position can be reliably prevented.

Further, when manual focus adjustment is disabled, the second drive ring 73 is pushed toward the object by the rib 81c, and the second wave washer 74 is further pushed into a compressed state. The biasing force of the wave washer 74 increases. Therefore, the rotational torque when operating the operating ring 76 also increases. Since the force required to operate the operation ring 76 increases, the user can intuitively grasp that manual focus adjustment is no longer possible.

Further, when manual focus adjustment is disabled, the first drive ring 71 is still pressed against the planetary rollers 55 by the first wave washer 72 . Therefore, the output ring 51 maintains a state of being sandwiched between the drive gear ring 61 and the first drive ring 71 . Therefore, even when vibration or the like is applied, the output ring 51 does not rotate unintentionally, and the shift of the focal position can be prevented. At this time, by setting the pressing force F1 by the first wave washer 72 to be a sufficient pressing force for operating the differential mechanism 6, the brush 87 detects that the release switch 85 has been operated to the release position. , the automatic focus adjustment may be performed by energizing the focus motor 3 instead of prohibiting the automatic focus adjustment.

[Second embodiment]
9 and 10 are vertical cross-sectional views showing a part of the structure extracted from the lens barrel according to the second embodiment of the present invention. 9 shows a state in which manual focus adjustment is possible, and FIG. 10 shows a state in which manual focus adjustment is impossible. FIG. 11 shows an exploded perspective view of the lens barrel releasing mechanism 8 according to the second embodiment of the present invention.

The lens barrel according to the second embodiment has a release switching ring member 82A that integrates the release member 81 and the release switching ring 82 of the first embodiment. In addition, in the second embodiment, the same or similar configurations as those of the lens barrel 1 according to the first embodiment are denoted by the same or similar reference numerals, and the description thereof is simplified or omitted.

As shown in FIG. 11, in the second embodiment, a cam 82a is formed on the image plane side surface of the release switching ring member 82A. The fixed ring 90 is formed with an engaging projection 90e at a position facing the cam 82a.

When the release switch 85 is at the release position, the release switching ring member 82A is urged toward the image plane by the compression coil spring 83 arranged between it and the pressing ring 84, and the cam 82a presses against the engaging projection 90e. ing. When the release switch 85 is operated from the release position to the connection position, the release switching ring member 82A rotates from the position where the cam 82a is pressed against the engagement projection 90e to the position where the cam 82a does not contact the engagement projection 90e. be done. As a result, the release switching ring member 82A is moved toward the image plane side by the biasing force of the compression coil spring 83, and the rib 82c formed on the release switching ring member 82A is separated from the second drive ring 73. When the rib 82c is separated from the second driving ring 73, focus adjustment according to the user's operation of the operating ring 76 becomes possible, as in the first embodiment.

When the release switch 85 is operated from the connection position to the release position, the release switching ring member 82A is interlocked with the movement of the release switch 85 and rotated to a position where the cam 82a presses against the engagement projection 90e. As a result, the release switching ring member 82A is moved toward the object side against the biasing force of the compression coil spring 83. As shown in FIG. The rib 82c of the release switching ring member 82A comes into contact with the second drive ring 73, and pushes the second drive ring 73 toward the object to move it. As a result, as shown in FIG. 10, a gap is generated between the end surface 73a of the second drive ring 73 and the end surface 71b of the first drive ring 71, and the gap between the second drive ring 73 and the first drive ring 71 is caused. Disconnected. When the connection between the second drive ring 73 and the first drive ring 71 is released, focus adjustment according to the user's operation of the operation ring 76 becomes impossible, as in the first embodiment.

In the second embodiment, the release member 81 and release switching ring 82 of the first embodiment are integrated into a single component (release switching ring member 82A), so the number of parts is reduced compared to the first embodiment. This makes it easier to design a compact lens barrel.

The foregoing is a description of exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiments of the present application also include the contents of appropriate combinations of the embodiments and the like exemplarily specified in the specification or the obvious embodiments and the like.

IA Photographing device 1 Lens barrel 2 Camera body 3 Focus motor (actuator)
4 automatic focus adjustment mechanism 5 manual focus adjustment mechanism 6 differential mechanism 8 release mechanism 51 output ring (planetary carrier)
55 planet roller (planet)
61 drive gear ring 71 first drive ring 73 second drive ring 76 operating ring (operating member)
81 release member 82 release switching ring 84 pressing ring 85 release switch (release operation member)

Claims (3)

A lens barrel whose focus can be adjusted by moving the focus lens in the optical axis direction manually with an operation member or automatically with an actuator,
a first drive ring interlocking with the focus lens;
a second drive ring interlocking with the operating member;
a release unit capable of interlocking the first drive ring and the second drive ring and releasing the interlocking of the first drive ring and the second drive ring;
a planetary carrier rotatable around the optical axis of the lens barrel;
a transmission unit that converts the rotation of the planetary carrier about the optical axis into rectilinear motion and transmits the motion to the focus lens, thereby moving the focus lens forward and backward in the direction of the optical axis;
a planetary roller rotatably supported by a shaft extending in a direction orthogonal to the optical axis provided in the planetary carrier;
a first biasing portion that biases the first drive ring against the planetary roller;
an annular member biased by the planetary roller and interlocking with the actuator;
a second biasing portion that biases the second drive ring against the first drive ring;
with
The release unit is
a user-movable release operating member;
a moving member that alternatively moves between a first position and a second position when the release operation member is moved by a user;
has
The moving member is
When moving to the first position, the driving force of the second driving ring is increased by pushing the second driving ring against the biasing force of the second biasing portion and separating it from the first driving ring. so as not to be transmitted to the first drive ring,
When it moves to the second position, it separates from the second drive ring and presses the second drive ring against the first drive ring by the biasing force of the second biasing portion. so that the driving force of the two drive rings is transmitted to the first drive ring;
When the driving force of the second driving ring is transmitted to the first driving ring, the annular member remains stationary without rotating due to friction torque generated between the annular member and other members in the lens barrel. the first drive ring rotates around the optical axis to rotate the planetary rollers around the axis and rotate the planetary carrier around the optical axis;
When the driving force of the actuator is transmitted to the annular member, the friction torque generated between the first drive ring and the first biasing portion and the second driving force are generated by the second biasing portion. While the first drive ring is stationary without rotating due to the friction torque generated between it and the ring, the annular member rotates around the optical axis to rotate the planetary rollers around the axis. rotating the planet carrier about the optical axis;
lens barrel. μ1F1<μ3F2
however,
μ1: static friction coefficient between the first driving ring and the first biasing portion μ3: static friction coefficient between the first driving ring and the second driving ring F1: due to the first biasing portion biasing force F2: the biasing force by the second biasing unit is satisfied;
The lens barrel according to claim 1 . Equipped with the lens barrel according to claim 1 or claim 2 ,
photographic equipment.

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