JP3120871B2 - Lens barrel for autofocus camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focusing (AF) camera, and more particularly to a lens barrel of an AF single-lens reflex camera.

[0002]

2. Description of the Related Art In an AF single-lens reflex camera, switching between manual focus (MF) and auto focus (AF) has conventionally 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 AF
The state in which the axes are coupled is the AF state, and the rotation of the AF axis moves the focus lens group in the optical axis direction, and simultaneously rotates the focus ring on the lens side. To switch to the MF state, the coupling between the body-side AF axis and the lens-side driven AF axis is released, 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 (to make it narrower) or is disposed at the tip of the lens barrel so as not to disturb the AF ring. On the other hand, if it is at the tip of the cylinder, it is difficult to operate the MF. Also, the AF and MF changeover switches are provided on the body side, and there is a problem that it is difficult to operate depending on the camera position.

[0003]

SUMMARY OF THE INVENTION The present invention has been made based on the above awareness of the problems with the conventional lens barrel for an AF camera, and has
Can be switched on the lens side, and the same A
Switching between AF and MF, and MF by F-MF switching ring
It is an object of the present invention to obtain an easy-to-use lens barrel capable of performing focusing at the time. The present invention also provides
It is an object of the present invention to obtain a lens barrel capable of electrically reliably detecting that the AF-MF switching ring is at the AF position and the MF position.

The lens barrel of the present invention has an AF position in the optical axis direction.
Manual movement and rotation to the MF position
Possible AF-MF switching ring; focus lens with rotation
Ring to move the lens in the optical axis direction; AF-MF switching
Connect the focus ring to the AF mechanism at the AF position on the ring.
And disconnect the focus ring and AF mechanism at the MF position.
First clutch mechanism to be disengaged; AF of AF-MF switching ring
The AF-MF switching ring and the focus ring are relatively rotatable or integrated with each other depending on the position and the MF position .
The clutch mechanism; comprises a, the second clutch mechanism,
Move in the radial direction perpendicular to the optical axis provided on the focus ring.
Movable clutch pin; radial inside of this clutch pin
A leaf spring fixed to the focus ring, engaging the end; and
And if the position on the inner surface of the AF-MF
AF-M having a small diameter portion and a large diameter portion formed by
When the F switching ring is at the AF position, the large-diameter portion
AF-MF faces the radial outer end of the pin in a non-contact state.
When the switching ring is at the MF position, the small diameter portion
Contacting the radially outer end of the
Characterized by being pushed inward in the radial direction against the urging force
are doing. According to this configuration, the AF-MF switching ring
When the AF-MF switching ring is in the
F-operation, and when the AF-position is set, the AF-
MF can be performed by rotating the MF switching ring.
it can. Then, the second clutch machine is configured as described above.
Because of this, the rotation operation of the AF-MF switching ring during MF
Transmitting force to the focus ring without rotating lugs
And good operability. Second clutch as described above
The structure is simple if it is a mechanism.

In the lens barrel of the present invention described above, the first lens
The latch mechanism rotates together with the focus ring in the rotation direction
And the AF-MF switching ring corresponds to the AF position and the MF position.
, A clutch gear that advances and retreats in the optical axis direction; and an AF mechanism
To rotate the AF-MF switching ring to the AF position.
At one time, it is engaged with this clutch gear and is in the MF position
The AF mechanism side AF gear
And the AF position of the AF-MF switching ring.
It operates independently of the clutch gear according to the position and MF position.
Switch means for detecting the AF state or the MF state.
It is desirable to have. With this configuration, when the AF-MF switching ring is moved from the AF position to the MF position or from the MF position to the AF position, the clutch gear and the AF mechanism side A
Even if the meshing with the F gear is not released or the meshing is incomplete, the switch means detects the switching independently of the movement of the clutch gear, so that the necessary control of the zoom motor or the like can be performed. it can.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A focus lens frame 12 supporting a focus lens L1 is fitted on the inner periphery of a front portion of the fixed ring 10 fixed to the camera body. The fixed ring 10 is composed of a plurality of annular members, but all are illustrated as fixed rings 10 in the drawings. A linear guide groove 13 is formed in the fixed ring 10, and a guide pin 14 fixed to the focus lens frame 12 is fitted in the linear guide groove 13. The fixed ring 10 has a linear guide groove 1 of the focus lens frame 12.
3, the focus ring 15 is rotatably fitted. On the inner surface of the focus ring 15, a lead groove 16 for fitting the guide pin 14 is formed. Therefore, when the focus ring 15 is rotated, the focus ring 15 is moved in accordance with the straight guide groove 13, the lead groove 16 and the guide pin 14. Lens frame 12 (focus lens L1)
Moves in the optical axis direction to perform focusing.

An interlocking pin 18 projecting in the radial direction is fixed to the focus ring 15. On the other hand, an intermediate ring 19 is rotatably fitted on the inner surface of the fixed ring 10, and an interlocking arm 20 is fixed to the intermediate ring 19 by a fixing screw 21. The interlocking arm 20 is engaged with the interlocking pin 18 of the focus ring 15 to integrate the intermediate ring 19 and the focus ring 15 in the rotation direction. That is, the intermediate ring 19 and the focus ring 15 always rotate equally, and the intermediate ring 19 also
It can be said that it constitutes a ring.

On the fixed ring 10, an AF-MF switching ring 31 is supported so as to be capable of moving straight forward and backward and rotating in the direction of the optical axis. A decorative ring 32 is fitted on the outer periphery of the AF-MF switching ring 31. In this embodiment, the AF-
The state where the MF switching ring 31 is moved to the front moving end (FIG. 1) is the AF position, and the state where the MF switching ring 31 is moved to the rear moving end (FIG. 2) is the MF position. The inner surface of the AF-MF switching ring 31 is provided with an annular V-shaped groove 3 corresponding to the AF position and the MF position.
The fixed ring 10 is provided with a click ball 35 fitted into one of the annular V-shaped grooves 33 and 34 and a leaf spring 36 for urging the click ball 35.

A clutch mechanism (second clutch) shown in FIGS. 1, 2, 5, and 6 is provided between the AF-MF switching ring 31 and the intermediate ring 19.
Switch mechanism) . This clutch mechanism is A
When the F-MF switching ring 31 is at the front AF position,
The rotation of the intermediate ring 19 is made freely with respect to the AF-MF switching ring 31, and the AF-MF switching ring 31 and the intermediate ring 19 are integrated in the rotation direction when in the rear MF position. On the inner surface of the AF-MF switching ring 31, a small diameter portion 44, a tapered diameter portion 45, and a large diameter portion 46 are sequentially formed from the front. On the other hand, a plurality of radial clutch pin holes 47 are formed in the intermediate ring 19 at different positions in the circumferential direction. The clutch pin holes 47 have a small diameter portion 44, a tapered diameter portion 45, and a large diameter portion 46. Is slidably fitted with a clutch pin 48 having the same position. This clutch pin 4
The protrusion 8 is restricted in its outwardly projecting end by its retaining head 49, and is urged to move outward by a leaf spring 50. The leaf spring 50 has one end fixed to the inner surface of the intermediate ring 19 by a fixing screw 38.

The AF-MF switching ring 31 has stopper surfaces 39, 40 formed on the front and rear end surfaces thereof, and the fixed ring 10 abuts on the stopper surfaces 39, 40 to move forward and backward. Are provided. The stopper surfaces 39 and 40 are provided with cushioning elastic members 43 that cushion the collision with the movement range limiting walls 41 and 42, respectively.

A transmission ring 24 fitted on the inner surface of the intermediate ring 19 is located inside the AF-MF switching ring 31. The transmission ring 24 has an annular groove 25 and AF
When the roller 26 fixed to the MF switching ring 31 is fitted, and the AF-MF switching ring 31 moves back and forth, both the transmission rings 24 move back and forth.

Behind the transmission ring 24, a clutch gear 27
Is fitted movably in the optical axis direction. The clutch ring 28 has a leaf spring 29
, It is always urged to move forward, and
Are rotated together with the intermediate ring 19.

The clutch gear 27 includes a clutch ring 28
(AF-MF switching ring 31)
The gear meshes with or disengages the AF gear 55 on the mechanism side. That is, the clutch gear 27, the AF gear 55, etc.
Connects AF mechanism and focus ring 15 (intermediate ring 19)
Or a clutch mechanism for releasing the connection (first clutch machine
Structure). As shown in FIG. 3, the AF gear 55 is interlocked with an AF joint shaft 56 exposed at the rear end of the fixed ring 10 and rotated from the body side via a gear train 57. Therefore, in the AF state, the AF gear 55
When rotation is given to the joint shaft 56, it rotates at a fixed position.

In the fixed ring 10, an AF-MF switching ring 31 is provided.
A switch means 60 for detecting the AF position and the MF position is provided. The switch means 60 includes a fixed substrate 61
And a slide plate 62 supported on the fixed substrate 61 so as to be movable in a direction parallel to the optical axis. A front end of the slide plate 62 has an inner side provided at a rear end of the transmission ring 24. An engagement bent portion 64 with the flange 63 is formed. A tension spring 67 that urges the slide plate 62 forward is stretched between the pin 65 planted on the slide plate 62 and the pin 66 planted on the fixed substrate 61. An AM switch 68 is provided on the fixed substrate 61 and the slide plate 62. The AM switch 68 detects the AF state when the slide plate 62 moves forward according to the tension spring 67, and the slide plate 62
The MF state is detected by moving backward against the MF.
The switch means 60, that is, the AM switch 68 operates according to the position of the AF-MF switching ring 31 irrespective of the engagement state of the clutch gear 27 and the AF gear 55. FIG. 7 illustrates this relationship.

The front end of the AF-MF switching ring 31 and the fixed ring 1
Between 0 and 0, a lock mechanism 70 that locks the AF-MF switching ring 31 when the AF-MF switching ring 31 is moved to the AF position is provided. As shown in FIGS. 1 and 2, the lock mechanism 70 has a plurality of lock grooves 71 provided at an appropriate angular interval in the fixed ring 10, while the AF-MF
The switching ring 31 is provided with a lock pin 72 that fits into the lock groove 71 when the switching ring 31 is at the AF position, and a biasing spring 73 thereof.

Accordingly, the present lens barrel operates as follows. As shown in FIG. 1, in the AF state in which the AF-MF switching ring 31 is moved forward, the tip of the clutch pin 48 supported by the intermediate ring 19 is located at the position of the large-diameter portion 46 on the inner surface of the AF-MF switching ring 31. Therefore, the clutch gear 27 of the clutch ring 28 urged forward by the leaf spring 29 is kept out of contact with the AF-MF switching ring 31.
Are in mesh with the AF gear 55. In this state, when the AF joint shaft 56 is rotated by a driving source on the camera body side, the rotation is performed by the AF gear 55, the clutch ring 28, the intermediate ring 19, the interlocking arm 20, and the interlocking pin 18.
Is transmitted to the focus ring 15 through the AF, so that AF is performed. At this time, the lock pin 72 of the AF-MF switching ring 31 is fitted in one of the lock grooves 71 of the fixed ring 10. Even if the lock pin 72 is not fitted in the lock groove 71, if the small angle AF-MF switching ring 31 is rotated to any one, the fitting state will be established soon, and therefore the AF
In this state, the AF-MF switching ring 31 does not rotate,
There is no inconvenience due to the rotation of the grip.

In this AF state, the transmission ring 24 is moving forward and its inner flange 63 is
Because the engaging bent portion 64 of the switch means 6 is open, the switch means 6
The zero slide plate 62 slides forward by the tension spring 67, and therefore, the AM switch 68 detects the AF state.

On the other hand, as shown in FIG.
When the F switching ring 31 is moved rearward to the MF state, the tip of the clutch pin 48 supported on the intermediate ring 19 becomes AF-
It comes into strong frictional contact with the small diameter portion 44 on the inner surface of the MF switching ring 31,
The AF-MF switching ring 31 and the intermediate ring 19 are integrated, while
With the rearward movement of the AF-MF switching ring 31, the transmission ring 24 moves rearward, pushing the clutch ring 28 and disengaging the clutch gear 27 and the AF gear 55. Further, the lock pin 72 is detached from the lock groove 71 so that the AF-MF switching ring 3
Unlock 1 In this state, the AF-MF switching ring 31
Is manually transmitted to the intermediate ring 19 via the small-diameter portion 44, the clutch pin 48 and the clutch pin hole 47, and further transmitted to the focus ring 15 via the interlocking arm 20 and the interlocking pin 18. Is transmitted to Therefore, MF is performed.

In the MF state, the inner flange 63 of the transmission ring 24 pushes the engagement bent portion 64 and slides the slide plate 62 backward against the tension spring 67. Therefore, the AM switch 68 of the switch means 60 detects the MF state and sends the signal to the body. As a result, AF from the body side
No rotation is applied to the joint shaft 56. Even if the AF joint shaft 56 is rotated, the rotation is not transmitted to the clutch gear 27 because the AF gear 55 and the clutch gear 27 are not meshed.

As shown in FIG. 7, in the present invention, the detection of the AF state and the MF state by the AM switch 68 is performed by the AF-M
This is performed at a specific stroke position of the F switching ring 31, and does not depend on the engagement state of the clutch gear 27 and the AF gear 55.
For this reason, when switching between AF and MF by the AF-MF switching ring 31, particularly when switching from MF to AF, the clutch gear 2
7 and AF gear 55 are not fully engaged,
A signal is provided that the state has been entered. Therefore, AF
Since the AF gear 55 rotates through the joint shaft 56, when the AF gear 55 rotates by a small angle, the engagement with the clutch gear 27 pushed forward by the plate 29 occurs, and the AF state is reliably achieved. Can be transferred to.

In the above embodiment, the present invention is applied to an AF lens barrel of a type that obtains AF driving force from the camera body side. An AF lens mirror of a type in which an AF motor is built in the lens barrel. The present invention can be applied to a cylinder.

As described above, the lens barrel of the present invention is an AF-M capable of linearly moving forward / backward and rotating in the direction of the optical axis.
An F switching ring is provided, and when the AF-MF switching ring is at the MF position, MF is performed by rotation of the AF-MF switching ring, and when the AF-MF switching ring is at the AF position, the AF-MF switching ring is rotated. The AF-MF switching ring does not rotate during the AF operation because the AF operation can be performed without the need for the AF operation. Therefore, since the AF-MF switching ring can be gripped during AF, gripping properties are improved, and after switching to the MF, the AF-MF switching ring is rotated by a rotating operation.
Since the MF can be performed, a lens barrel excellent in operability that does not require a re-holding operation when shifting to the MF can be obtained. So
Then, especially during MF, release the clutch pin on the focus ring side.
Engage with the small-diameter portion on the AF-MF switching ring side with the radial biasing force
To integrate the AF-MF switching ring and focus ring
The rotation lag between the AF-MF switching ring and the focus ring
It is possible to obtain a good operational feeling free from the occurrence of. Further, the present invention moves the AF-MF switching ring from the AF position to the MF position.
Alternatively, when the clutch gear is moved from the MF position to the AF position, even if the engagement between the clutch gear and the AF mechanism-side AF gear is not released or the engagement is incomplete, the switch means operates independently of the movement of the clutch gear. Since switching is detected,
Control required for a zoom motor or the like can be performed.

[Brief description of the drawings]

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

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

FIG. 3 is a plan view illustrating a relationship between a clutch gear and an AF mechanism-side AF gear.

FIG. 4 is a plan view of the switch means.

FIG. 5 is a cross-sectional view of the clutch in an AF state, taken along line AA of FIG. 1;

FIG. 6 is a cross-sectional view of the clutch in the MF state, taken along line BB of FIG. 2;

7 is an explanatory diagram showing a movement stroke of an AF-MF switching ring of the lens barrel in FIG. 1 and an operation state of a portion related thereto.

[Explanation of symbols]

 Reference Signs List 10 fixed ring 12 focus lens frame 13 straight guide groove 14 guide pin 15 focus ring 16 lead groove 20 interlocking arm 24 transmission ring 25 annular groove 26 roller 27 clutch gear 28 clutch ring 29 leaf spring 31 AF-MF switching ring 33 34 annular V Groove 35 Click ball 39 40 Stopper surface 41 42 Movement range limiting wall 43 Buffer elastic member 44 Small diameter portion 45 Tapered portion 46 Large diameter portion 48 Clutch pin 55 AF gear 56 AF joint shaft 60 Switch means 61 Fixed substrate 62 Slide plate 67 Tension spring 68 AM switch 70 Lock mechanism 71 Lock groove 72 Lock pin 73 Urging spring

Claims (3)

(57) [Claims] 1. A hand to an AF position and an MF position in an optical axis direction.
AF-MF switching for moving straight forward and rotating
Ring; a lens for moving the focus lens in the optical axis direction with rotation.
Focus ring; focus at the AF position of the AF-MF switching ring
Connect the ring to the AF mechanism and set the focus at the MF position.
First clutch machine that releases the connection between the ring and the AF mechanism
Configuration; Depending on the AF position and the MF position of the AF-MF changeover commutative rings, and the AF-MF changeover commutative rings and the focus ring to rotate freely relative, or the second clutch mechanism to integrate; with a second The clutch mechanism is provided in the focus ring and is provided in a radial direction orthogonal to the optical axis.
A clutch pin movably mounted on the clutch pin;
Leaf springs fixed to the carcass ring; and the AF-MF changeover
Small elements formed at different positions in the optical axis direction on the inner surface of the ring
Diameter and large-diameter portion; comprises a, when the AF-MF changeover commutative rings is in the AF position, the large
The radial part is in non-contact with the radial outer end of the clutch pin
When the AF-MF switching ring is at the MF position,
The radial portion contacts the radially outer end of the clutch pin and
Push the clutch pin radially against the biasing force of the leaf spring.
A lens for autofocus cameras characterized by being pushed inward
Lens barrel. (2) The lens for an autofocus camera according to claim 1.
In the lens barrel, the first clutch mechanism includes: The focus ring is rotated integrally with the focus ring in the rotation direction.
The optical axis is changed according to the AF position and the MF position of the F-MF switching ring.
Clutch gear moving forward and backward; and By the AF mechanism
The AF-MF switching ring is moved to the AF position.
is there When engaged with this clutch gear, it is in the MF position
The AF mechanism side AF gear
Ya; With Further, the AF position and the MF position of the AF-MF switching ring
Depending on the position, it operates independently of the clutch gear,
Switch means for detecting the F state or the MF state; A lens barrel for an autofocus camera equipped with a. (3) An autofocus camera according to claim 1 or 2.
In the lens barrel for AF, on the inner surface of the AF-MF switching ring,
Further, a tapered diameter portion connecting the small diameter portion and the large diameter portion is formed.
Lens barrel for autofocus cameras.