JPH07225335A - Lens barrel for automatic focusing camera - Google Patents

Abstract

PURPOSE:To provide a lens barrel for AF camera preventing the relative rotation of both rings even when an AF-MF changeover ring is completely rotated and abutted on the rotary end at the time of changing to a MF position. CONSTITUTION:In the frictionally engaging state of an AF-MF changeover ring 31 with a focusing ring 15 by means of a friction clutch mechanism, a lens barrel for AF camera comprises a mechanical clutch mechanism 48 mechanically connecting the AF-MF changeover ring 31 and the focusing ring 15 and the mechanical clutch mechanism 48 comprises many locking groove parts 65 provided on either of the AF-MF changeover ring 31 and the focusing ring 15 along its peripheral direction, a locking pin 45 supported by the opposite party of either the AF-MF changeover ring 31 or the focusing ring 15 and engaging with the locking groove part 65 and an energizing means 46 for engaging the locking pin 45 with the locking groove part 65 when the position of the locking pin 45 is coincided with either of many locking groove parts 65.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an autofocus (AF) camera, and more particularly to a lens barrel of an AF single-lens reflex camera.

[0002]

2. Description of the Related Art Conventionally, in AF single-lens reflex cameras, switching between manual focus (MF) and auto focus (AF) has been performed on the body side. In an AF single-lens reflex camera, an AF axis is provided on the camera body, and a driven AF axis driven by the AF axis is provided on the interchangeable lens side. Both A
The state in which the F axis is coupled is the AF state, and the rotation of the AF axis causes the focus lens group to move in the optical axis direction.
At the same time, the focus ring on the lens side rotates. To enter the MF state, the body-side AF axis and the lens-side driven AF axis are disconnected, and the lens-side focus ring is manually rotated. In this conventional lens barrel, the focus ring on the lens side also rotates during AF. For this reason, the focus ring itself is made smaller (narrower) and placed at the tip of the lens barrel so as not to get in the way during AF. On the other hand, if it is located at the tip of the cylinder, it is difficult to operate during MF. The AF / MF selector switch is provided on the body side, and depending on the camera position,
There was a problem that it was difficult to operate.

Therefore, the applicant of the present invention has provided an AF-MF switching ring capable of performing a rectilinear advance / retreat operation and a rotation operation in the optical axis direction. When the AF-MF switching ring is at the MF position in the optical axis direction, Manual focusing is performed by the rotation of the AF-MF switching ring, and when in the AF position,
A lens barrel for an autofocus camera has been proposed which performs an AF operation without rotating the AF-MF switching ring (see Japanese Patent Application No. 3-337497).

A lens barrel for an autofocus camera having the above structure proposed by the applicant is an AF-MF switching ring AF lens.
A clutch mechanism for making the AF-MF switching ring and the focus ring relatively rotatable or integrated according to the position and the MF position, for example, a clutch pin provided on either one of the AF-MF switching ring and the focus ring. Alternatively, the lock pinion is frictionally engaged with the other engagement portion, thereby integrating the two in the rotational direction. Therefore, from AF to MF
When switched to, the AF-MF switching ring and the focus ring can be instantly connected without a rotational lug in the rotational direction, but since both are connected by frictional force as described above, the AF-MF switching ring is When fully rotated in one of the circumferential directions and applied to the rotating end, the force is AF-
When the friction force between the MF switching ring and the focus ring is overcome, the two may rotate relative to each other.

[0005]

SUMMARY OF THE INVENTION The present invention is based on the awareness of the problem with the lens barrel for an AF camera as described above, and when switching to the MF position, the AF-MF switching ring is completely rotated in the circumferential direction so that the AF-MF switching ring reaches the turning end. The object is to obtain a lens barrel for an AF camera that does not rotate the both relative to each other even when it is applied.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a focus ring for moving a focus lens in the optical axis direction in accordance with rotation; a manual rectilinear movement operation and rotation to an AF position and an MF position in the optical axis direction. An operable AF-MF switching ring; and, depending on the AF position and the MF position of the AF-MF switching ring, make the AF-MF switching ring and the focus ring rotatable relative to each other or by a frictional force. In a lens barrel for an autofocus camera having a friction clutch mechanism for engaging the AF-MF switching ring and the focus ring mechanically in a frictionally engaged state of the AF-MF switching ring and the focus ring by the friction clutch mechanism. It has a connectable mechanical clutch mechanism, and this mechanical clutch mechanism is
-A large number of locking groove portions provided in one of the MF switching ring and the focus ring along the circumferential direction thereof;
A lock pin that is supported by the other of the MF switching ring and the focus ring and that engages with the lock groove; and the lock pin is locked when the position of the lock pin matches any of a number of lock grooves. And a biasing means for engaging with.

[0007]

The present invention will be described below with reference to the illustrated embodiments.
1 to 12 show a first embodiment of a lens barrel according to the present invention. In FIG. 1, 10 is a fixed ring, and this fixed ring 10 has a mount 11 for mounting with a camera body at a rear end portion in the optical axis direction, and an inner peripheral cylindrical portion 41 on a front inner circumference in the optical axis direction. Have The fixed ring 10 also has a pair of stopper protrusions 18 that are protruded toward the inner peripheral side at a predetermined angular interval from each other in the circumferential direction.

A focus lens frame 12 supporting a focus lens L1 is fitted to the inner circumference of the inner cylindrical portion 41 so as to be movable back and forth in the optical axis direction. The inner cylindrical portion 41 has a straight guide groove 13 parallel to the optical axis direction.
A guide pin 14 fixed to the focus lens frame 12 is movably fitted in the lens 3. Although the fixed ring 10 is actually composed of a combination of a plurality of annular members, it is drawn as a single member in the figure for convenience.

A focus ring 15 is fitted to the fixed ring 10 so as to be positioned outside the straight guide groove 13 and relatively rotatable. A straight guide groove 1 is provided on the inner peripheral surface of the focus ring 15.
A lead groove 16 into which the guide pin 14 is fitted is formed so as to face the lead groove 3. Therefore, when the focus ring 15 is rotated, the focus lens frame 12 is moved in the optical axis direction together with the focus lens L1 in accordance with the linear guide groove 13, the lead groove 16 and the guide pin 14, so that focusing can be performed. Also, focus ring 15
A stopper projection 19 is provided on the outer periphery of the rear portion so as to project radially outward.

The rotation range of the focus ring 15 is the fixed ring 1.
A pair of stopper protrusions 18 on the inner circumference of the 0 and the focus ring 1
5 is regulated by the stopper projection 19 on the outer periphery. Further, a photographing distance scale 20 is provided on the outer peripheral side of the focus ring 15, and an observation window 21 is provided at a position corresponding to the photographing distance scale 20 of the fixed ring 10, and the photographer takes an image through the observation window 21. The distance scale 20 can be observed. In addition, O in FIG. 1 indicates an optical axis, and L2 indicates a taking lens.

Focus ring 15 and AF-MF switching ring 31
A first clutch mechanism (friction clutch mechanism) 44 that connects the focus ring 15 and the AF-MF switching ring 31 with a frictional force when the AF-MF switching ring 31 is moved to the MF position is provided between and. Has been. Focus ring 15
Has a rack-shaped circumferential groove 80 and a rack-shaped circumferential lock groove 81 that form the first clutch mechanism 44 together with a lock pinion 76 described later on the outer periphery of the rear portion. The focus ring 15 also has an internal gear 24 on the inner periphery of the rear portion. The rack-shaped circumferential groove 80 is used for the focus ring 15.
A rack-shaped circumferential lock groove 81 provided on the rear end side
Are provided on the front side of the rack-shaped circumferential groove 80. The rack-shaped circumferential groove 80 and the rack-shaped circumferential lock groove 81 are provided in the rear portion of the focus ring 15 over the entire circumferential direction thereof.

Focus ring 15 and AF-MF switching ring 31
A second clutch mechanism (mechanical clutch mechanism) 48 that mechanically connects the focus ring 15 and the AF-MF switching ring 31 when the AF-MF switching ring 31 is moved to the MF position is provided between and. Has been. As shown in FIGS. 3 and 8, at the rear end of the focus ring 15, a lock pin 45 that opens toward the rear of the optical axis and forms a part of the second clutch mechanism 48 is slidable. A lock pin housing hole 42 for housing is formed. This lock pin storage hole 42
Are formed at four positions by shifting the position by 90 ° in the circumferential direction of the focus ring 15 (see FIG. 11). Each of the four lock pin housing holes 42 has a female screw 42a on the inner periphery of the rear portion and a recess 42b on the inner periphery of the front portion.
A male screw 43a formed on the outer circumference of the annular retaining member 43 is screwed into the female screw 42a of the lock pin housing hole 42.

The annular retaining member 43 is a focus ring 1.
5 has a flange 43b for abutting against the rear end wall and a through hole 43d through which the lock pin 45 slidably penetrates. An engagement groove 43c for engaging a tightening tool such as a flat-blade screwdriver is formed in the front portion of the flange 43b. The lock pin 45 is formed in a hemispherical shape at the tip end facing the rear of the optical axis, and the outer diameter of the main body portion is smaller than the inner diameter of the through hole 43d of the annular retaining member 43. An insertion hole 45a, into which the compression spring 46 is inserted, is formed on the inner peripheral side of the main body portion and opens toward the front of the optical axis.
The lock pin 45 has a flange 45b that abuts on the front end portion of the annular retaining member 43 to prevent the lock pin 45 from coming out behind the optical axis. The outer diameter of the flange 45b is slightly smaller than the inner diameter of the lock pin housing hole 42. Further, the compression spring 46 inserted into the insertion hole 45a of the lock pin 45 is
The rear end portion is contracted to the lock pin housing hole 42 in a state of abutting against the recess 42b. In the compression spring 46, the lock pin 45 that abuts an intermediate portion between a locking groove portion 65a and a wall portion 65b, which will be described later, forcibly rotates the AF-MF switching ring 31 and the focus ring 15 relatively, and the locking groove portion 6 is pressed.
The spring force is set to be relatively weak so that it does not slip into 5a.

An AF-MF switching ring 31 is supported at an intermediate portion of the fixed ring 10 in the optical axis direction so that the AF-MF switching ring 31 can be manually moved straight forward and backward and manually rotated. This A
A decorative ring 32 is fitted around the outer circumference of the F-MF switching ring 31 with its rotation with respect to the switching ring 31 being restricted. In this embodiment, the state in which the AF-MF switching ring 31 is moved to the moving end behind the optical axis (Fig. 1) is the AF (autofocus) position, and the state is moved to the moving end ahead in the optical axis (Fig. 2)
Is the MF (manual focus) position. AF-M
On the inner surface of the F switching ring 31, annular V grooves 33 and 34 are formed corresponding to the AF position and the MF position, and the fixed ring 10 has one of the annular V grooves 33 and 34. A click ball 35 that fits in the and a leaf spring 36 that urges the click ball 35 are provided.

As shown in FIG. 11, at the front end of the AF-MF switching ring 31, there is 9 in the circumferential direction of the switching ring 31.
Four lock pinions 76 are provided which are displaced by 0 °. The four lock pinions 76 constitute the first clutch mechanism 44 by the rack-shaped circumferential groove 80 and the rack-shaped circumferential lock groove 81, one of which is represented and described with reference to FIG. To do.

At the front end of the AF-MF switching ring 31, a recess 82 is formed by notching the outer peripheral surface of the switching ring 31 by a predetermined amount, and a bearing groove 75 is formed at the front end of the recess 82. ing. This bearing groove 75 is provided in the lock pinion 7
6 has a rotary shaft housing portion 75a for housing the rotary shaft 77, and a pinion housing portion 75b for housing the lock pinion 76 in the central portion of the rotary shaft 77 so as to be rotatable and regulate the lateral movement with respect to the optical axis O. is doing. Rotating shaft accommodating portion 75a
The width in the front-rear direction of the optical axis is substantially equal to the diameter of the rotating shaft 77, and the depth of the rotating shaft housing portion 75a is smaller than the diameter of the rotating shaft 77. As a result, the rotary shaft accommodating portion 75
a can accommodate more than half of the vertical direction when the rotating shaft 77 is viewed in the axial direction, and the rotating shaft housing portion 75a can regulate the movement of the rotating shaft 77 in the front-rear direction in the housed state. . To the left and right of the lock pinion 76 in the recess 82, the lock pinion 76 is elastically contacted with the projecting portion of the rotary shaft 77 to urge the lock pinion 76 toward the focus ring 15, that is, the rack-shaped circumferential groove 80 or the rack-shaped circumferential lock groove 81. A pair of leaf springs 78 are provided for this purpose. The pair of leaf springs 78 has a rear end portion fixed to the rear portion of the recess 82 by a fixing screw 7.
It is fixed by 9, and the free end is elastically contacted with the protruding portion of the rotary shaft 77.

Since the focus ring 15 has a cylindrical shape, when the reference pitch line of the rack-shaped circumferential groove 80 is considered as a cylindrical surface rotated along this cylinder, FIG.
As shown in, the diameter is defined as φPC1, and similarly, the diameter of the cylinder along the reference pitch line of the lock groove portion 81 is φPC2.
Can be defined as The diameter φPC2 of the lock groove portion 81 according to the reference pitch line is larger than the diameter φPC1 of the circumferential groove portion 80 according to the reference pitch line by 2α.
This α indicates a gap between the reference pitch line 80a of the circumferential groove portion 80 and the pitch circle 76a of the lock pinion 76.
The outer diameter of the rack-shaped circumferential groove 80 and the outer diameter of the rack-shaped circumferential lock groove 81 are both φD1.

Therefore, in the AF state of FIG. 1 in which the AF-MF switching ring 31 is moved rearward, the lock pinion 76 causes the tooth flank of the rack-shaped circumferential groove 8 by the urging force of the leaf spring 78.
However, since there is a gap α between the pitch circle 76a of the lock pinion 76 and the reference pitch line 80a of the rack-shaped circumferential groove 80, the lock pinion 76 is located on the rack-shaped circumferential groove 80. The focus ring 15 is freely moved in the circumferential direction. Therefore, the AF-MF switching ring 3
Since 1 and the focus ring 15 are not integrated, the AF-MF switching ring 31 can be freely rotated with respect to the focus ring 15 to perform the AF operation regardless of the presence of the lock pinion 76. Further, in the MF state of FIG. 2 in which the AF-MF switching ring 31 is moved forward, the lock pinion 76 riding on the rack-shaped circumferential lock groove 81 causes the leaf spring 78.
The AF-MF switching ring 31 and the focus ring 15 are strongly pressed against the lock groove 81 by the urging force of the AF-MF switching ring 31 and the focus ring 15 due to the frictional force between the lock pinion 76 and the lock groove 81.
Relative rotation is restricted and they are connected.

As shown in FIGS. 3 and 11, an inner peripheral flange 65 having a thickness substantially equal to the outer diameter of the fixing screw 79 is formed on the inner peripheral side of the AF-MF switching ring 31. There is. On the inner peripheral flange 65, a large number of locking groove portions 6 that constitute the second clutch mechanism 48 together with the lock pin 45.
5a is formed along the circumferential direction. Further, the inner peripheral flange 65 has the same number of wall portions 65b as the many locking groove portions 65a between the locking groove portions 65a and 65a. Each of the plurality of locking groove portions 65a has a predetermined angular interval so that when the focus ring 15 is approached, the lock grooves 45a can coincide with the lock pins 45 provided at equal angular intervals at four positions in the circumferential direction of the focus ring 15. There is. The number of locking grooves 65a may be any number as long as the condition of the angular interval is satisfied and the locking pin 45 has a width to engage with each other without a gap. By increasing the number as much as possible, the connecting operation of the focus ring 15 and the AF-MF switching ring 31 can be made finer.

On the other hand, an AF transmission shaft 26, to which a pinion 25 meshing with the internal gear 24 is fixed, is supported on the fixed ring 10 so as to be movable in the axial direction parallel to the optical axis O. A pinion 27 that meshes with a pinion 29 fixed to the front end of the driven AF shaft 28 is provided at the axial rear portion of the AF transmission shaft 26.
Is fixed. The driven AF shaft 28 is rotatably supported inside the rear portion of the fixed ring 10, and as is well known,
When mounted on a camera body (not shown), it is connected to an AF shaft in the body and receives the rotation of a drive motor provided on the camera body side. When the driven AF shaft 28 rotates,
The rotation is transmitted to the pinion 25 via the pinions 29 and 27 and the AF transmission shaft 26.

A third clutch mechanism 53 is provided between the focus ring 15 and the AF transmission shaft 26. When the AF-MF switching ring 31 is at the rear AF position, the third clutch mechanism 53 is provided with the pinion 2 of the AF transmission shaft 26.
5 is meshed with the internal gear 24 of the focus ring 15, and when in the front MF position, the pinion 25 of the AF transmission shaft 26 and the internal gear 24 of the focus ring 15 are disengaged.

As shown in FIG. 7, a spring bearing flange 66 and a spring bearing flange 58b having a larger diameter than the flange 66 are fixed at a substantially central position in the axial direction of the AF transmission shaft 26 with a predetermined distance therebetween. ing. The spring receiving flange 66 is provided between the spring receiving flanges 66 and 58b of the AF transmission shaft 26.
A spring bearing ring 58a having a larger diameter is slidably fitted. A compression spring 63 is contracted between the spring receiving ring 58a and the spring receiving flange 58b of the AF transmission shaft 26. The moving end of the compression spring 63 has a spring receiving ring 58a.
Is regulated at a position where it comes into contact with the spring receiving flange 66.

A switching arm 60 is provided on the side of the pinion 27 with respect to the spring receiving flange 58b of the AF transmission shaft 26. The switching arm 60 is bent by approximately 90 ° in a side view, has a forked portion 61 at one end thereof, and has an engagement pin 56 projecting upward at the other end thereof.
An annular groove 54 (FIG. 1) that is long in the circumferential direction is formed on the inner surface of the AF-MF switching ring 31, and the fitting small diameter portion 10b (FIG. 1) forming a part of the fixed ring 10 has an optical axis direction. A long engaging groove 10c is formed at the bottom. The switching arm 60 has the other end portion engaged with the engagement groove 10c, and the pin 56 is slidably fitted into the annular groove 54.
The transmission shaft 26 is engaged with the side surface of the spring receiving flange 58.
It is in contact with b.

Further, the fixing small-diameter portion 1 forming a part of the fixed ring 10 is located forward of the fitting small-diameter portion 10b in the optical axis direction.
0a includes a switching arm 55 paired with the switching arm 60.
Are fixed by fixing screws 54. Similar to the switching arm 60, the switching arm 55 has a forked portion 57 at one end and a screw hole 55a for inserting the fixing screw 54 at the other end. There is. The bifurcated portion 57 allows the small diameter spring receiving flange 66 to pass through without engaging with the small diameter spring receiving flange 66, and only engages with the large diameter spring receiving ring 58a. With these structures, the compression spring 63
It is possible to constantly urge the transmission shaft 26 rearward of the optical axis, that is, in the direction in which the pinion 25 is meshed with the internal gear 24.

Between the AF-MF switching ring 31 and the fixed ring 10, when the AF-MF switching ring 31 is moved to the AF position, the AF-MF switching ring 31 and the fixed ring 10 are mechanically connected. A fourth clutch mechanism 64 is provided. Figure 3,
The fourth clutch mechanism 64 will be described with reference to FIGS. 9 and 11. The fixing small-diameter portion 10a of the fixed ring 10 has four lock pin housing holes 51 which are deviated by 90 ° in the circumferential direction. Each lock pin storage hole 51 has an outer diameter equal to that of the lock pin 45.
2 for slidably accommodating, has the same inner diameter as the lock pin accommodating hole 42, has a female screw 51a on the inner circumference on the front side, and has a recess 51b at the rear end on the inner circumference. ing. A male screw 52a formed on the outer circumference of the annular retaining member 52 is screwed into the female screw 51a of the lock pin housing hole 51. The annular retaining member 52 has a flange 52b for abutting against the front wall of the fixed ring 10, and a through hole 52d for allowing the lock pin 62 to slidably penetrate therethrough on its inner circumference. An engagement groove 52c for engaging a tightening tool such as a flat-blade screwdriver is formed on the front wall of the flange 52b.

The lock pin 62 is the AF-MF switching ring 31.
Is engaged with a large number of locking groove portions 65a formed in the inner peripheral flange 65 of the switching ring 31 when the gear is switched to the MF position, and the fourth clutch mechanism 64 is configured with the large number of locking groove portions 65a. is doing. That is, the plurality of locking groove portions 65 a constitute the second clutch mechanism 48 by engaging with the lock pin 45, and the lock pin 6
The second clutch mechanism 64 is configured by engaging with the second clutch mechanism 64. Therefore, the second clutch mechanism 48 and the fourth clutch mechanism 64 also use a large number of locking groove portions 65a formed in the inner peripheral flange 65 as a common component member, thereby reducing the number of parts.

The outer diameter of the lock pin 62 is approximately equal to the inner diameter of the through hole 52d of the annular retaining member 52, and the compression spring 59, which is open to the rear side of the optical axis, is inserted into this main body. An insertion hole 62a for forming is formed. The lock pin 62 further abuts against the rear end of the annular retaining member 52 and restricts the flange 6 from slipping forward of the optical axis.
2b. The outer diameter of the flange 62b is slightly smaller than the inner diameter of the lock pin housing hole 51. The compression spring 59 inserted into the insertion hole 62a of the lock pin 62 is contracted in the lock pin storage hole 51 with its rear end abutting against the recess 51b. Compression spring 59
Means that the lock pin 62, which comes into contact with the intermediate portion between the locking groove portion 65a and the wall portion 65b, which will be described later, has the
The spring force is set to be relatively weak so as not to forcibly slide into the locking groove portion 65a while being forcibly rotated.

Therefore, the present lens barrel having the above structure operates as follows. As shown in FIG. 1, in the AF state in which the AF-MF switching ring 31 is moved backward, the first clutch mechanism 44
And the second clutch mechanism 48 releases the integrated rotational relationship between the AF-MF switching ring 31 and the focus ring 15, and the third clutch mechanism 53 causes the pinion 25 of the AF transmission shaft 26 to move to the internal gear 24 of the focus ring 15. The fourth clutch mechanism 64 engages with each other and locks the AF-MF switching ring 31 to the fixed ring 10.

That is, since the lock pinion 76 meshes with the rack-shaped circumferential groove 80 in the AF state,
Due to the existence of the gap α between the pitch circle 76a and the reference pitch line 80a of the rack-shaped circumferential groove 80, the focus ring 15 can freely move in the circumferential direction on the rack-shaped circumferential groove 80. Therefore, the AF-MF switching ring 31 and the focus ring 1
It is not integrated with 5 (Fig. 3). Further, in the same AF state, the four lock pins 62 supported by the fixed ring 10 are
Are engaged with corresponding ones of a number of locking groove portions 65a on the inner circumference of the AF-MF switching ring 31 that has moved rearward of the optical axis, so that the rotation of the AF-MF switching ring 31 with respect to the fixed ring 10 is blocked. The two are mechanically connected (Fig. 3).

In the same AF state, the four lock pins 45 supported by the focus ring 15 are separated from the inner peripheral flange 65 of the AF-MF switching ring 31.
While keeping the non-engagement state with the -MF switching ring 31 (Fig. 3), the pinion 25 of the AF transmission shaft 26, which is urged rearward of the optical axis by the compression spring 63, is connected to the internal gear 24 of the focus ring 15. They are engaged (Fig. 1). In this state,
When the driven AF shaft 28 is rotated by the AF shaft on the camera body side, the rotational force is transmitted to the focus ring 15,
As a result, AF is performed. Thus, in the AF state,
The rotation of the focus ring 15 causes the AF-MF switching ring 31 to rotate.
Does not rotate, and the conventional inconvenience due to the rotation of the grip (decorative ring 32) does not occur. AF-
When the MF switching ring 31 is switched to the AF position, the lock pin 62 of the fourth clutch mechanism 64 is moved to the position shown in FIG.
Even if the AF-MF switching ring 31 is slightly rotated in either direction in the circumferential direction even if it abuts against the wall portion 65b and is not engaged with the locking groove portion 65a, the lock pin 62 is rotated.
Can be slightly moved in the circumferential direction to be engaged with corresponding ones of the locking groove portions 65a.

From this AF state, the AF-MF switching ring 31
Is moved to the front side of the optical axis to switch to the MF state, the first clutch mechanism 44 and the second clutch mechanism 48 connect the AF-MF switching ring 31 and the focus ring 15 to each other, and the third clutch mechanism 53. Disengages the pinion 25 of the AF transmission shaft 26 from the internal gear 24 of the focus ring 15, and the fourth clutch mechanism 64 causes the AF-MF switching ring 3 to move.
The lock for the fixed ring 10 of 1 is released.

That is, when the AF-MF switching ring 31 is moved to the MF position in front of the optical axis, the lock pinion 76 rolls on the rack-shaped circumferential groove 80 together with the switching ring 31 and rides on the lock groove portion 81. In this case, the outer diameter of the rack-shaped lock groove portion 81 is equal to that of the rack-shaped circumferential groove 80, and the diameter φPC2 of the lock groove portion 81 according to the reference pitch line.
However, since the diameter is larger than the diameter φPC1 of the reference groove of the circumferential groove portion 80, the lock pinion 76 is pushed up by x1 together with the support shaft 77. Then, the lock pinion 76 is bent by the leaf spring 78 corresponding to the movement amount x1.
Therefore, the urging force that has become stronger corresponding to the bending amount is received via the support shaft 77. As a result, the lock pinion 76
Is strongly pressed against the rack-shaped lock groove 81, a strong frictional force is generated between the lock pinion 76 and the rack-shaped lock groove 81. Therefore, the focus ring 15 is prevented from moving relative to the AF-MF switching ring 31, and is integrated with the AF-MF switching ring 31 in the rotational direction (FIG. 6).

When switching to the MF position, the AF-MF switching ring 31 separates from the four lock pins 62 supported by the focus ring 15, so that the locking groove 65a separates from the lock pins 62. Instead, it approaches the lock pin 45 of the second clutch mechanism 48 and engages with the lock pin 45. In that case, as shown in FIG. 5, the lock pin 45 abuts the wall portion 65b to lock the groove portion 65a for locking.
Even if the AF-MF switching ring 31 is not engaged with the lock pin 45, if the switching ring 31 and the focus ring 15 rotate slightly relative to each other in the process of rotating the AF-MF switching ring 31 in the circumferential direction, all the lock pins 45 move slightly in the circumferential direction. Then, they are engaged with corresponding ones of the locking groove portions 65a. Therefore, the AF-MF switching ring 3
Even when the first clutch mechanism 1 is completely rotated in one of the circumferential directions and abuts against the rotation end (stopper), and the first clutch mechanism 44 slightly slips, the second clutch mechanism 48 surely engages. After that, no slip occurs at the turning end.

In the same MF state, the four lock pins 62 supported on the fixed ring 10 side have the AF-MF switching ring 31.
Of the AF-M.
The AF transmission shaft 2 is maintained in the disengaged state with the F switching ring 31 (FIG. 6) and is urged rearward of the optical axis by the compression spring 63.
The pinion 25 of 6 is moved in the same direction by the switching arm 60 that moves forward together with the AF-MF switching ring 31,
The engagement between the focus ring 15 and the internal gear 24 is released (FIG. 2). Therefore, by manually rotating the AF-MF switching ring 31, it is possible to rotate the focus ring 15 integrally with the AF-MF switching ring 31 and independently of the AF mechanism.

In this embodiment, when the AF-MF switching ring 31 is moved forward with respect to the focus ring 15, the lock pinion 76 rolls on the rack-shaped circumferential groove 80 and the rack-shaped lock groove portion 81. The resistance in the direction of movement is extremely low. As a result, the AF-MF switching ring 3
It is possible to improve the operation feeling when switching between AF and MA of No. 1.

Next, a second embodiment of the lens barrel according to the present invention will be described with reference to FIGS. The first clutch mechanism 44 of the second embodiment is different from the above-described first embodiment only in that the rack-shaped circumferential groove 80 at the rear end of the focus ring 15 is eliminated and a small diameter portion 83 is provided. Except for this, all have the same configuration. The small diameter portion 83 is provided on the lock pinion 7
There is a gap x2 (FIG. 15) between the tooth flank 6 and the lock pinion 76 cannot contact the focus ring 15 at all on the small diameter portion 83. That is, according to this embodiment, when the AF-MF switching ring 31 is moved rearward (FIGS. 13, 15 and 16), the AF-MF switching ring 31 is moved.
The focus ring 15 can be freely rotated with respect to the AF-MF switching ring 31 without integrating the focus ring 15 and the focus ring 15. If the AF-MF switching ring 31 is moved forward (FIGS. 14, 17, and 18), the lock pinion 76 rides on the lock groove 81 and locks the lock pinion 76 in the same manner as in the first embodiment. Groove 8
The AF-MF switching ring 31 and the focus ring 15 can be integrated in the rotational direction by strongly pressing against 1 to generate a frictional force, so that the MF is possible.

In the first and second embodiments described above, all four lock pins 45 and 62 can all simultaneously coincide with the corresponding locking groove portions 65a at any rotational position of the AF-MF switching ring 31. Although the lock pins 45 and 62 are provided at the respective positions, the number of the lock pins 45 and 62 is not limited to four, and a plurality of other lock pins 45 and 62 are provided. At that time, it can be divided into a set that abuts against the wall portion 65b. According to this configuration, the AF-MF switching ring 3
When the inner peripheral flange 65 of No. 1 approaches the lock pin 45 or 62, no matter which rotation position of the AF-MF switching ring 31, the lock pin 45 or 62 of either of the above two sets is located.
Can be engaged with the locking groove portion 65a instantaneously and reliably.

In the above first and second embodiments, A
The electric switching between the F state and the MF state is performed by, for example, a brush (not shown) interlocked with the AF-MF switching ring 31.
And a cord plate (not shown) provided correspondingly. Further, in the first and second embodiments, the rack-shaped circumferential lock groove 81 and the lock pinion 7 are provided.
6 is reversed, that is, the rack-shaped circumferential lock groove 81.
On the side of the focus ring 15 and the lock pinion 76
The present invention can be realized by supporting the AF-MF switching ring 31. Further, the arrangement relationship between the large number of locking groove portions 65a and the lock pin 45 that constitute the second clutch mechanism 48 is reversed, that is, the locking groove portion 65a is provided on the focus ring 15 side and the lock pin 45 is provided on the AF-MF switching ring 31. Even if it supports, this invention is materialized.

In the first and second embodiments, the present invention is applied to the AF lens barrel of the type in which the AF driving force is obtained from the camera body side, but the AF motor is built in the lens barrel. The present invention can also be applied to a type of AF lens barrel.

[0040]

As described above, according to the present invention, the AF-MF switching ring and the focus ring can be mechanically connected to each other when the AF-MF switching ring and the focus ring are frictionally engaged by the friction clutch mechanism. A mechanical clutch mechanism, and the mechanical clutch mechanism includes a large number of locking groove portions provided in one of the AF-MF switching ring and the focus ring along the circumferential direction thereof; AF-MF switching A lock pin that is supported by the other of the ring and the focus ring and that engages with the locking groove; and that engages the lock pin with the locking groove when the position of the lock pin matches any of a number of locking grooves When the AF camera is switched to the MF position, even if the AF-MF switching ring is completely rotated in the circumferential direction and abutted against the rotation end, the AF camera does not rotate relative to each other. It can be obtained use the lens barrel.

[Brief description of drawings]

FIG. 1 is an upper half longitudinal sectional view in an AF state showing a first embodiment of a lens barrel for an AF camera according to the present invention.

FIG. 2 is an upper half longitudinal sectional view of the same MF state.

FIG. 3 is a cross-sectional view showing a main part of the lens barrel for an AF camera of FIG. 1 in an engaged state of a fourth clutch mechanism.

4 is a cross-sectional view showing a main part of the lens barrel for an AF camera of FIG. 1 in a non-engaged state of a fourth clutch mechanism.

5 is a cross-sectional view showing a main part of the lens barrel for an AF camera of FIG. 2 in a non-engaged state of a second clutch mechanism.

6 is a cross-sectional view showing a main part of the lens barrel for an AF camera of FIG. 1 in an engaged state of a second clutch mechanism.

FIG. 7 is an enlarged perspective view showing a main part of a third clutch mechanism.

FIG. 8 is a perspective view showing a main part of a second clutch mechanism in an exploded state.

FIG. 9 is a perspective view showing a main part of a fourth clutch mechanism in an exploded state.

FIG. 10 is a perspective view showing the first clutch mechanism of the first embodiment as viewed obliquely from the front.

FIG. 11 is a diagram showing an AF-MF switching ring viewed from the front of the optical axis.

FIG. 12 is an AF in a state different from that of FIG. 11 viewed from the front of the optical axis.
It is a figure which shows a -MF switching ring.

FIG. 13 is an upper half longitudinal sectional view in an AF state showing a second embodiment of the lens barrel for an AF camera according to the present invention.

FIG. 14 is an upper half longitudinal sectional view of the same MF state.

FIG. 15 shows a main part of a lens barrel for an AF camera shown in FIG.
It is sectional drawing shown in the engagement state of a 4th clutch mechanism.

FIG. 16 shows a main part of a lens barrel for an AF camera shown in FIG.
It is a sectional view showing the 4th clutch mechanism in a non-engagement state.

FIG. 17 shows a main part of a lens barrel for an AF camera shown in FIG.
It is sectional drawing which shows a 2nd clutch mechanism in a non-engagement state.

FIG. 18 shows a main part of a lens barrel for an AF camera shown in FIG.
It is a sectional view showing an engaged state of the second clutch mechanism.

FIG. 19 is a perspective view showing the first clutch mechanism of the second embodiment as viewed obliquely from the front.

[Explanation of symbols]

 10 Fixed Ring 15 Focus Ring 31 AF-MF Switching Ring 42 Lock Pin Storage Hole 44 First Clutch Mechanism (Friction Clutch Mechanism) 45 Lock Pin 46 Compression Spring (Biasing Means) 48 Second Clutch Mechanism (Mechanical Clutch Mechanism) 51 Lock Pin housing hole (second lock pin housing hole) 59 Compression spring 62 Lock pin (second lock pin) 64 Fourth clutch mechanism 65a Lock groove portion 65b Wall portion L1 Focus lens O Optical axis

Claims (3)

[Claims] 1. A focus ring for moving a focus lens in the optical axis direction with rotation; an AF position and an MF in the optical axis direction.
AF- that allows manual rectilinear movement and rotation to a position
An MF switching ring; and a friction clutch mechanism that allows the AF-MF switching ring and the focus ring to rotate relative to each other or engages with each other by a frictional force according to the AF position and the MF position of the AF-MF switching ring; In a lens barrel for an automatic focusing camera having the above, a mechanical clutch capable of mechanically connecting the AF-MF switching ring and the focus ring in a frictionally engaged state of the AF-MF switching ring and the focus ring by the friction clutch mechanism. This mechanical clutch mechanism has a plurality of locking groove portions provided in one of the AF-MF switching ring and the focus ring along the circumferential direction thereof; and the AF-MF switching ring. And a lock pin that is supported by the other of the focus ring and that engages with the locking groove; when the position of the lock pin matches any one of a number of locking grooves, Automatic focus camera lens barrel and having a; and biasing means engaging the Kkupin the locking groove. 2. The focus ring according to claim 1, wherein the focus ring has a lock pin accommodating hole for accommodating a lock pin in a portion facing the wall portion between the lock groove portion and the lock groove portion, and the lock pin has the above-mentioned structure. A lens barrel for an automatic focusing camera, which is housed in the lock pin housing hole in a state of being urged to project toward the locking groove and the wall by urging means. 3. The fixed ring according to claim 1, further comprising a fixed ring connected to the body side of the camera, forming a part of the fixed ring and facing the locking groove and the wall between the locking grooves. A second lock pin storage hole is formed in the portion to be engaged, and the AF-MF switching ring and the fixed ring side can be mechanically connected to each other by engaging with the lock groove portion in the second lock pin storage hole. A lens barrel for an autofocus camera, wherein a second lock pin is housed in a state in which it is biased so as to project toward the locking groove and wall.