JPH02137811A - lens barrel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a lens barrel in which a focusing lens can be driven for autofocus by a vibration wave motor, and more specifically, it also enables focusing by manual operation. This relates to a lens barrel.

(Prior Art) Generally, in lens barrels that use a vibration wave motor to drive autofocus, apart from this autofocus, by operating a vibration wave motor drive button provided on the camera body, It is common to provide a so-called power focus mechanism that enables manual focusing without using distance measurement information.

By the way, in the above-mentioned lens barrel, the driving power source for the vibration wave motor may not function properly due to power consumption, etc., due to power consumption of the power source installed on the camera body side to which the lens barrel is attached, for example. If it runs out, there is a problem that not only autofocus but also the power focus cannot be operated.

Therefore, both the camera body and the lens barrel are equipped with a mechanism that allows photographing by mechanical operation.
Even if the power supply runs out and electrical drive such as autofocus is no longer possible, it is often desirable to maintain a system that allows photographing to be performed manually.

(Problems to be Solved by the Invention) By the way, when it is possible to take pictures by manual operation as described above, the camera equipped with the vibration wave motor has the following problems.

In other words, in a camera equipped with a vibration wave motor as the drive means for autofocus, if we consider the case where the focusing lens is directly extended manually, the vibration wave motor frictionally drives the rotor using traveling waves generated in the stator. Since this is a mechanism that generates rotational force of the rotor, the frictional resistance between the rotor, which is rotated together with the focus lens, and the stator, which is integrated with the fixed lens barrel, is large, and this vibration wave motor is If an attempt is made to manually rotate the rotor in a non-energized state, the load increases, making it difficult to perform manual focusing by smoothly extending the lens barrel.

Therefore, the inventor of the present invention took into account the characteristics of cameras equipped with such a vibration wave motor, and developed two cases in which autofocus using a vibration wave motor (or the above-mentioned power focus) can be performed using a vibration wave motor, and a mechanical one using manual operation. The present invention has been made for the purpose of providing a lens barrel that is capable of performing movements suitable for smooth focus driving in both cases of focusing.

(Means for Solving the Problems) The lens barrel of the present invention, which has been made to achieve the above object, is characterized by being rotatable around the photographing optical axis by manual operation, and capable of rotating the optical axis. A manual focus ring that can be moved back and forth between two positions set apart in the axial direction, a vibration wave motor that can be driven and rotated around the optical axis, and a lens system. A lens holding tube is provided to hold the lens, and the rotation around the shooting optical axis is restricted, but linear movement along the optical axis direction is possible.The lens holding tube is screwed to the lens holding tube and the manual focus A screw member to which the rotation of either the ring or the vibration wave motor is transmitted to perform the linear movement of the lens holding cylinder, and either the manual focus ring or the vibration wave motor is selectively connected to the screw member. a first position in which the screw member is interlocked and connected only with either the manual focus ring or the vibration wave motor; It has a moving member that can switch the position between a second position in which the screw member is interlocked and connected only to the other of the vibration wave motors, and the position switching of the moving member is in the optical axis direction of the manual focus ring. The structure is given by movement between two positions.

In a particularly typical example of the present invention, the screw member and the manual focus ring or the vibration wave motor are interlocked and at least one, preferably both, are frictionally engaged. Furthermore, at least one of the pair of frictionally engaged members is a ring-shaped member, so that the frictionally engaged pair of members can smoothly engage without being affected by their rotational state. There it is.

(Function) The lens barrel of the present invention has the above-mentioned configuration, so that
It is not affected by the rotational load of the vibration wave motor during manual focusing.

In addition, when selectively interlocking the vibration wave motor or the manual focus ring by frictional engagement, the engagement is performed smoothly, and in particular, the pair of members to be frictionally engaged should be ring-shaped. This makes the engagement even smoother.

(Example) The present invention will be described below based on embodiments shown in the drawings.

1 to 3 are for explaining the configuration of Embodiment 1 of the present invention.

In Fig. 1 and θ Fig. 2, 3 is a lens barrel body, which is fixed to the fixed barrel 2 with unillustrated screws (the same applies hereinafter), and a bayonet mount for attaching it to the camera body. 1. Cover rings 4 and 5 are integrally fixed to these with screws.

A fixing ring 11 is fixed to the tip of the lens barrel body 3, and a parallel key 10 is fixed to the outer periphery of the fixing ring 11. A click spring 31 is fixed. This click spring 31 is fixed to the fixing ring 11 at the rear end side of the lens barrel (right side in the figure), and is movable at the tip side (left side in the figure) in the radial direction of the lens barrel. It is provided in a structure in which an engaging protrusion protruding radially outward is formed at the swinging tip.

Reference numeral 9 denotes a connecting ring assembled on the outer periphery of the fixed ring 11, and is inserted into the fitting recess of the inward trunk formed by the manual focus ring 6 and the front cylinder 8 integrally fixed thereto in the front-rear direction (left and right in the figure). Although they are not movable in the same direction, they are fitted so that they can slide in the same direction. Note that a rubber ring 7 is fitted around the outer periphery of the manual focus ring 6.

Further, a key groove 9a is provided on the inner circumference of the connecting ring 9, and the parallel key 10 of the fixed ring 11 engages with the key groove 9a. A manual focus ring 6 and a front barrel 8), which cannot be moved in the front-rear direction, are supported so as to be movable in the front-rear direction of the lens barrel. Further, the key groove 9a of the connecting ring 9 is shifted in position in the circumferential direction, and the fixed ring 1 is
A front click groove 9b and a rear click groove 9c which open radially inward form a pair spaced apart in the front-rear direction (the generatrix direction of the lens barrel) at positions facing the click spring 31 fixed to the lens barrel 1.
The front click groove 9b and the rear click groove 9c are provided so that the outward engaging protrusion at the tip of the click spring 31 can be engaged with the front click groove 9b and the rear click groove 9c. When the engagement protrusion of the click spring 31 engages with the front click groove 9b or the rear click groove 9c, the connecting ring 9, front cylinder 8, and manual focus ring 6, which are immovable in the front-rear direction, are The focus ring 6 can be switched between two positions in the front and back directions, and this can be done by operating the manual focus ring 6 from the outside.

16 is a rotating helicoid which is a screw member, and the fixing ring 1 is attached to the outer periphery of the outward flange on the front end side
A helicoidal threaded portion 16a is provided on the inner periphery of the cylindrical portion that extends in the generatrix direction, and is helicoidally coupled to a threaded portion 11a formed on the inner periphery of the lens holding tube. 35 are helicoidally connected. This lens holding cylinder 35 carries a plurality of lenses of the photographing optical system inside the cylinder, and the outer periphery of the rear end side has - (or a plurality of notches spaced apart in the circumferential direction) generatrix direction notches 35a. is formed, and when this fits with the linear key 33 fixed to the fixed barrel 2, the rotation of the lens holding barrel 35 around the photographing optical axis is restricted, but the movement (linear movement) in the direction of the optical axis is restricted.
is now allowed.

As described above, the fixed barrel 2 and the lens barrel fixed body, which is a group integrated therewith, and the manual focus ring 6 and the rotary body, which is a group integrated therewith, can move relative to each other by a fixed length in the front-back direction. In addition, rotation of a rotating body such as the manual focus ring 6 is allowed in the circumferential direction.

Further, the rotating helicoid 16 is rotatable relative to the fixed body, and can also transmit rotational force to the lens holding tube 35 inside by its own rotation, and the rotation of the lens holding tube 35 around the axis is By being restrained,
Along with the transmission of the rotational force, a linear movement in the optical axis direction is performed.

Next, a mechanism for rotating the rotating helicoid 16 will be explained.

In this example, there are two mechanisms for rotating this rotating helicoid 16.

One of them is a vibration wave motor, and in this vibration wave motor of this example, rotation of the stator 25 in the circumferential direction is restrained by a stator rotation stopper 26 fixed to the lens barrel body 3, and the stator 25 is restrained from rotating in the circumferential direction. The rear end of 25 in the optical axis direction is made of felt 24. The felt base 239 is brought into contact with the fixed cylinder 2 via the disk spring 22, and a pressing spring force is applied toward the front end in the axial direction. Reference numeral 15 denotes a rotary ring that is rotatably held on the inner circumference of the lens barrel body 3, and is held via a large number of steel balls 14 by an annular ball race 12, 13 fixed to the lens barrel body 3. is being done. A rotor holder 29 of the vibration wave motor is fixed to the rotary ring 15 with screws (not shown), and is fitted with a rotor 27 of the vibration wave motor via a vibration isolating rubber 28. Therefore, when the stator 25 of the vibration wave motor is driven by electricity, the rotor 27 is driven to rotate, and the rotary ring 15 fitted with the rotor 27 is rotatably held by the steel balls 14. It will be rotated relative to the lens barrel body 3.

This rotating ring 15 is connected to the rotating helicoid 16.
The rear end of the connecting bottle 17, which is fitted into an outward flange formed at the front end of the rotary ring 15 so as to be movable in the optical axis direction, is fitted into a shaft hole 15a recessed in the front end surface of the rotary ring 15. This allows it to rotate integrally in the circumferential direction.

That is, when the rear end of the connecting bin 17 is fitted into the front end shaft hole 15a of the rotary ring 15, the rotary ring 15 is rotated together with the rotor 12 by the vibration wave motor.
However, the rotating helicoid 16 is rotated together, and the lens holding cylinder 35 is therefore linearly moved in the optical axis direction, thereby performing a focusing operation. The connecting bottle 17 is connected to the shaft hole 15a.
If the rotating ring 15 and the rotating helicoid 16 are separated from each other, the coupling relationship between the rotating ring 15 and the rotating helicoid 16 is released, and the rotating helicoid 1
6 can be rotated independently of the vibration wave motor.

Another mechanism for rotating the rotating helicoid 16 is provided by rotating the manual focus ring 6.

That is, an annular member 20 to which a friction ring 19 is fixed is fixed to the front end of the connecting pin 17, which passes through the outward flange of the rotating helicoid 16 so as to be movable in the optical axis direction (see FIG. 3). ), which engages with the tip 8a of the inward flange of the front cylinder 8, thereby making it possible to frictionally transmit the rotational force of the manual focus ring 6 to the refid 16. Therefore, when the tip f48a of the inward flange of the front cylinder 8 and the friction ring 19 engage,
When the manual focus ring 6 integrated with the front barrel 8 is rotated by these frictional engagement forces, the rotational force is transmitted to the rotating helicoid 16, and the lens holding barrel 35 is moved linearly in the optical axis direction, thereby causing the engagement. If it comes off, the manual focus ring 6 will be rotated independently of the refid 16.

In this example, the connection relationship between the two rotating mechanisms for rotating the rotating helicoid 16 can be switched depending on the axial position of the connecting bin 17. That is, the connecting bottle 17 is held through the outward flange of the rotating helicoid 1B so as to be movable in the optical axis direction, and is constantly biased toward the rear end by a compression coil spring 18. Therefore, if there is no restriction on the movement toward the rear end, the connecting bottle 17 is moved toward the rear end in the optical axis direction, and the rear end is fitted into the tip shaft hole 15a of the rotary ring 15, and the vibration wave motor is activated. However, in the mechanism of this example, the manual focus ring 6 is placed in the front position in the optical axis direction (that is, the above-mentioned click spring 31 is engaged with the rear click groove 9c of the connecting ring 9), the inward flange tip 8a of the front cylinder 8
The friction ring 19 engages with the compression coil spring 18 to disengage the coupling pin 17 from the rotary ring shaft hole 15a, so that the rotational force from the manual focus ring 6 is transmitted to the refid 17 for rotation. It has become.

In this way, in the mechanism of this example, when the manual focus ring 6 (and front cylinder 8) is moved forward as shown in FIG. is released and engaged with the manual focus ring 6, and the lens holding cylinder 35
The manual focus ring 6 is now in a state where the linear movement of
In the state shown in FIG. 2, in which the rotary head 1B is moved toward the rear side as shown in FIG. A state is reached in which linear movement of the cylinder 35 can be performed by the vibration wave motor.

Next, an outline of the operation of the lens barrel having the above configuration will be explained.

As already explained, FIG. 1 shows the state during manual operation in which focusing can be performed using the manual focus ring.

That is, when the manual focus ring 6 is moved forward, the inward flange tip 8a of the front cylinder 8 comes into contact with the friction ring 19 at the tip of the connecting pin 17, and this connecting pin 17
Since a moderate pressing force is applied to the rear side by the compression coil spring 18, a frictional engagement state is obtained at the engaging portion, and at the same time, the rear end of the connecting bottle 17 is connected to the rotating ring 1.
It is separated from the shaft hole 15a of No.5. At this time, the click spring 31 engages with the rear click groove 9c, and the eighth gear is restrained in the optical axis direction of the manual focus ring 6.

When the manual focus ring 6 is rotated in the circumferential direction in this state, the rotating helicoid 16 is rotated via the connecting pin 17 due to the frictional engagement between the inward flange tip 11a of the front cylinder 8 and the friction ring 19. This rotational force is transmitted to the lens holding cylinder 35, but as mentioned above, since the lens holding cylinder 35 is restricted from rotating around the optical axis by the action of the straight key 33, the threaded portion 11a and the threaded portion 16a
The focus of the photographing optical system is moved by linear movement in the optical axis direction by the sum of the screw leads, and focusing is performed by manual operation.

In this example, a rotation stopper 34 is attached to the rotation helicoid 16, and the distance scale plate 3o fixed to the rotation stopper 34 can be observed from the outside through a peephole 5a formed in the cover ring 5. The operator can check the focal length of the distance scale plate 30 as it rotates as the rotating helicoid 16 rotates. Further, by providing the rotation stopper 34 of the rotating helicoid 16, when the manual focus ring 6 is rotated and the rotation stopper engages with a circumferential end (not shown), the rotation of the helicoid 16 will be further increased. Rotation is prevented, and any further rotation of the manual focus ring 6 causes the friction ring 19 to slip, causing it to rotate freely.

Further, during this manual operation, since the connection between the rotating helicoid and the vibration wave motor is released, the operation is not affected by the load of the vibration wave motor, and a smooth rotation operation can be performed.

As already explained, FIG. 2 shows a state during autofocus operation in which focusing can be performed using a vibration wave motor.

In other words, the manual focus ring 6 is connected to the parallel key 10.
When the click spring 31 is moved rearward in the optical axis direction using the action of , the click spring 31 disengages from the rear click groove 9c and engages with the front click groove 9b, thereby preventing further movement of the manual focus ring 6. At this time, since an appropriate pressing force is applied to the rear side of the connecting pin 17 by the compression coil spring 18, the rear end of the connecting pin 17 is attached to the rotating ring 15.
At the same time, the friction ring 19 at the front end of the connecting pin 17 and the inward flange tip 8a of the front cylinder 8 are engaged with each other for integral rotation. The frictional engagement is disengaged.

Note that an appropriate number of the connecting pins 17 are arranged in the circumferential direction of the rotating helicoid 16, and although the positions of these connecting pins 17 in the circumferential direction do not necessarily always coincide with the shaft hole 15a of the rotating ring 15, The shaft holes 15a of the ring 15 are provided at appropriate intervals on the circumferential surface so that the rear end of the connecting pin 17 can be fitted into the shaft hole 15a after the vibration wave motor has rotated by a predetermined amount. Just leave it as .

When the vibration wave motor is driven in this state, the rotary ring 15 rotates as the rotor 27 of the vibration wave motor rotates.
rotates, and the rotating helicoid 16 is rotated. Then, this rotational force is transmitted to the lens holding cylinder 35, and the lens holding cylinder 35 is transferred to the straight key 3 in the same way as in the manual operation described above.
Since the rotation around the optical axis is restrained by the action of 3, the focus of the photographing optical system moves linearly in the direction of the optical axis by the sum of the screw leads of the threaded part 11a and the threaded part 16a, and the autofocus by the vibration wave motor is performed. Focusing is performed manually.

In this case, even if the manual focus ring 6 is rotated, the rotational force is not transmitted to the rotating helicoid 16.

4 and 5 show Example 2 of the present invention, and since the overall structure of the lens barrel is the same as Example 1, in this example, only the mechanical part for switching transmission of rotational force is shown. is shown enlarged. In the drawings, components similar to those in Example 1 are given the same reference numerals, and their explanations are omitted.

The feature of the lens barrel in this example is that the rear end of the connecting pin 17 and the rotary ring 15 on the vibration wave motor side are connected not by fitting the shaft and the shaft hole in the first embodiment, but by connecting the rear end of the connecting pin 17 to the rotating ring 15 on the side of the vibration wave motor. Friction ring 36 fixed to the end and rotating ring 15
This is provided by frictional engagement with a friction ring 37 fixed to the front surface of the holder.

According to such a configuration, the configuration and operation of the rotational force transmission mechanism are basically the same as those in the first embodiment, but the interlocking connection with the vibration wave motor is achieved by a pair of frictional forces as described above. Because of the frictional engagement of the rings, there is an effect that the rotating helicoid 16 is quickly rotated when the vibration wave motor is energized.

That is, in Embodiment 1, when the shaft (connecting pin 17) and the shaft hole are misaligned in the circumferential direction as explained above, the vibration wave motor rotates until they fit together, whereas in this embodiment, Because it is based on frictional engagement, rapid rotation of the helicoid can be obtained.

According to each of the embodiments described above, switching between manual operation and autofocus drive is performed using a relatively small part called a connecting pin, so the switching is smooth and there are few failures due to the light load. Since the connecting pins are provided at a plurality of locations, there is no need for each connecting pin to switch at the same time, a slight shift in switching timing is allowed, and a reliable switching operation is achieved, resulting in high reliability.

Furthermore, the connecting pin is relatively small and space-efficient, and the lens barrel can be made smaller. At least, since the frictional force transmission during manual operation is provided by frictional engagement, the frictional part slides, resulting in excellent durability. There is also the effect of

Furthermore, since the manual focus ring is also used as the auto/manual operation switching member, the switching operation can be performed instantly, and furthermore, the manual focus ring's rotation operation and optical axis direction operation are independent, and both can be switched. Since it can be done smoothly, it also has the advantage of being able to provide extremely easy-to-operate interchangeable lenses.

(Effects of the Invention) As explained above, according to the present invention, during manual focusing, it is possible to perform a smooth focusing operation that is separate from the vibration wave mirror, and it is also possible to easily and smoothly switch between auto and manual modes. effective.

[Brief explanation of the drawing]

1 to 3 are diagrams showing an overview of the configuration of Example 1 of the lens barrel according to the present invention, with FIG. 1 showing the state during manual operation, and FIG. 2 showing the state during autofocus, respectively. . FIG. 3 is a diagram showing a single part of the friction ring that contributes to manual operation. FIGS. 4 and 5 are enlarged views of the switching mechanism part of the lens barrel of Example 2 according to the present invention. 4 shows the state during manual operation, and FIG. 5 shows the state during autofocus. 1... Bayonet mount 2... Fixed barrel 3... Lens barrel body 4.
5... Cover ring 6... Manual focus ring 7... Rubber ring 8... Front cylinder 9... Connection ring 9a... Keyway 9b... Front click groove
90... Rear click groove lO... Parallel key 11... Fixing ring lla... Threaded part 12,
13...Ball race 14...Steel ball 15...Rotating ring 15a...Shaft hole 16...
・Rotating helicoid lea...helicoid screw part 17
...Connecting pin 18...Compression coil spring 19
... Friction ring 20 ... Annular member 22 ...
Disc spring 23...Felt stand 24...Felt 25, φ, Stator 26...Stator rotation stopper 27...Rotor 29...Rotor receiver 31...Click spring 34...Rotation stopper 35... Lens holding cylinder 3...Friction ring 28...Vibration isolating rubber 30...Rotary scale plate 33...Straight key 35a...Notch 37...Friction ring and 4 others Figure 2

Claims (1)

[Claims] 1. A manual focus ring that can be rotated around the photographing optical axis by manual operation, and can also be moved back and forth between two positions set apart in the direction of the optical axis. , a vibration wave motor that is provided to be able to drive and rotate around the optical axis, and a lens system that holds the lens system, and although rotation around the photographing optical axis is restricted, linear movement along the optical axis direction is possible. a lens holding tube provided in the lens holding tube; and a screw screwed to the lens holding tube to which the rotation of either the manual focus ring or the vibration wave motor is transmitted to perform the linear movement of the lens holding tube. member, and switchable rotational force transmission means for selectively connecting either the manual focus ring or the vibration wave motor to the screw member, and the rotational force transmission means is configured to selectively connect either the manual focus ring or the vibration wave motor to the screw member. Position switching is possible between a first position in which the screw member is interlocked and connected only with either one of the motors and a second position in which the screw member is interlocked and connected only with the other of the manual focus ring or the vibration wave motor. 1. A lens barrel characterized in that the lens barrel has a movable member, and the position of the movable member is changed by moving the manual focus ring between two positions in the optical axis direction. 2. The lens barrel according to claim 1, wherein at least one of the threaded member and the manual focus ring or the vibration wave motor is coupled by frictional engagement. 3 The interlocking connection between the screw member and the manual focus ring is made into a frictional engagement, and a limit is set for the rotation range of the screw member, and rotation of the manual focus ring beyond the limit causes slippage of the frictional engagement portion. 3. The lens barrel according to claim 1, wherein the lens barrel is moved from the center.