JPH09318861A - Driving device and lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a device compact and to make length in an arraying direction short in the case respective elements are serially arranged by providing a 2nd roller being a pressuring and separating mechanism on an output member. SOLUTION: A connecting plate 20 and a manual connecting plate 24 frictionally transmit driving force from oscillation type motor and a focusing operation ring 9 to a 1st roller 22. An output ring 21 is integrally rotated with the roller 22 rolling by receiving a relative moving difference between the plates 20 and 29. A 1st pressuring means(a belleville spring 15 and a nut 16) and a 2nd pressuring means(a holding ring 25, a reinforcing plate 26, a belleville spring 27 and a nut 28) press the frictional transmitting surfaces of the coupling plate 20 and the coupling plate 24 to contact surfaces contacting with the roller 22, respectively. Then, the 2nd roller 23 receiving the pressing force of the 2nd pressuring means 25 to 28 acting on the roller 22 so that the rotation of the output ring 21 may be allowed between the fixed part of a device main body side and the roller 23 is provided on the output ring 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device which does not require a switching operation between a manual operation and an automatic operation, and a lens barrel which is used for driving a moving lens. The present invention relates to a drive device and a lens barrel that use a motor as a drive source for automatic operation.

[0002]

2. Description of the Related Art Conventionally, a lens drive having a ring-shaped vibrating motor built therein so that an autofocus operation and a manual focus operation can be performed substantially continuously without requiring a special switching operation. A lens barrel having a built-in vibration type motor has been proposed by the applicant, and some of the proposals have been commercialized by the applicant.

Among the lens barrels proposed by the applicant of the present invention, there is a lens barrel which utilizes a differential mechanism using rollers as a planetary mechanism. The roller of the planetary mechanism has a rotation axis in a radial direction perpendicular to the optical axis, and has an output end face from a manual ring for performing a manual focus operation and a vibration type motor for performing an auto focus operation. The differential mechanism is arranged such that the roller of the planetary mechanism is sandwiched between the output end face and an output ring that picks up the revolution of the roller and rotates to provide the final output.

Even if the manual ring is rotated when the rotation of the output ring is restricted, the manual ring is rotated when the rotation of the output ring is restricted so that an unreasonable force is not applied to the mechanism. In this case, the friction coefficient is set so that the roller and the output end face from the manual ring always slide out. This friction mechanism, when the roller and the output end surface of the rotor of the vibration type motor start to slide,
Since the output end surface of the rotor receives friction at one point as the roller rotates without rolling, a trace of wear remains on the output end surface. On the other hand, when the roller and the output end face from the manual ring slide out first, the roller does not roll or rotate, only the manual ring rotates, so the entire output end face of the manual ring receives friction with the roller and wears out. It is advantageous to Then, the focusing lens is driven by the output ring, and the characteristics of the structure of the vibration type motor are fully utilized especially in the manual focusing operation.

A vibration wave motor, which is one of the typical vibration type motors, has a circular ring-shaped metal elastic body (corresponding to a stator) in which a traveling wave is formed and which forms an output member. The rotor is pressed against a pressing member such as a spring, and the rotor is frictionally driven by a traveling wave formed in the elastic body. In the differential mechanism, the pressing force of the pressing member is applied along the optical axis direction. Even if the output member being received is rotated, the pressing force of the pressurizing member acts so that the manual ring maintains the non-rotation state, and conversely, when the manual ring is rotated to perform the manual focus, the vibration is generated. Since the rotor of the mold motor is in pressure contact with the stator, the non-rotating state of the rotor is maintained, and it is possible to switch between autofocus operation and manual focus operation without using any switching mechanism. You have to like.

In the conventional lens barrel having the above-mentioned structure, a roller is used as a planetary mechanism in a differential mechanism for switching between manual focus operation and autofocus operation without conversion, and a vibration type on both sides of the roller is used. The driving force is transmitted by frictionally contacting the output end face of the motor and the output end face of the manual focus ring.

However, since the pressing force for the frictional contact uses the pressing force of the pressing member for pressing the rotor to the stator of the vibration type motor, the optimum pressing force that can bring out the performance of the vibration type motor is obtained. Had been set.

Therefore, when a focus lens having a large lens load is driven, slippage occurs in frictional contact with the roller, the output from the vibration type motor cannot be efficiently transmitted, and the lens is sufficiently driven. I couldn't do it. As a measure against that, since the slippage first occurs between the roller and the output end surface of the manual ring, the coefficient of friction between the roller and the output end surface of the manual ring is compared with that of the roller and the output end of the rotor of the vibration type motor. The friction coefficient should be increased within a range that is smaller than that, but it is difficult to change the friction coefficient steplessly because it depends largely on the materials of the surfaces that contact each other.

Therefore, in order to efficiently transmit the output of the vibration type motor, a pressure member for pressing the rotor and the stator of the vibration type motor is integrally formed with the output end face of the manual ring and the rotor on the outer peripheral surface of the roller. Separately the pressurizing members that pressurize to generate the slip torque of the frictional contact of the end face of the rotating rotating member, while applying the optimum pressurizing force that can bring out the performance to the vibration type motor, on the other hand A configuration has been proposed in which a pressing force capable of sufficiently producing a slip torque of frictional contact between the output end surface of the manual ring and the end surface of the rotating member that rotates integrally with the rotor and rotates in the same manner is applied. Hereinafter, this structure is referred to as a pressure separation type.

An example of the structure of the pressure separation type will be described with reference to FIG. FIG. 2 is a cross-sectional view of a conventional focus drive unit, and the center of the optical axis is located at the bottom of the figure. 10
Reference numeral 1 denotes a unit support cylinder for holding each component of the focus drive unit. Reference numeral 102 denotes an annular vibration member (hereinafter referred to as a stator) having a trapezoidal cross section. An electrostrictive element 103 is joined to one end surface of the stator 102 and vibrates. Reference numeral 104 is an annular vibration absorber made of felt or the like that is pressed against the surface of the electrostrictive element 103.

Reference numeral 105 denotes a first pressing means, which is a first disc spring for urging the vibration absorber 104 in the optical axis direction. 1
Reference numeral 06 designates a first portion which is screwed into a screw portion formed on the inner diameter of the unit support cylinder 101 to adjust the pressing force of the disc spring 105.
The nut. Reference numeral 107 is a detent for integrally holding the inner diameter of the unit support cylinder 101 and for restricting the rotation of the stator 102. 108 is the stator 1
A rotating body (hereinafter referred to as a rotor) 02 that receives a rotational force about the optical axis.

Reference numeral 110 denotes a first connecting plate which rotates integrally with the rotor 108 via a rubber ring 109 and is brought into contact with a first roller described later. 111 is a first and a second described later.
Is a roller support shaft that pivotally supports the roller and is attached to the unit support cylinder and projects from the inner diameter of the unit support cylinder toward the optical axis. 112 is the first connecting plate 110
Is a first roller that abuts against and receives pressure from the first pressure means, and has a bearing structure that is divided into two bodies on the inner diameter side and the outer diameter side in order to eliminate rotation loss and is engaged by balls. There is.

Reference numeral 113 is a second roller which comes into contact with a second connecting plate 114, which will be described later, and which receives pressure from the second pressure means. The second roller has two inner and outer diameter sides to eliminate rotation loss. Separately, the bearing structure is engaged by the balls. The third roller 116 contacts the third roller 116 and is pressurized by the second pressure means, and is engaged with the claw of the first connecting plate 110 to transmit the rotation. Two
It is a connecting plate.

Reference numeral 115 has a plurality of shafts 115a extending in a radial direction with respect to an optical axis that rotatably supports a third roller 116 described later, and has an optical axis of the third roller 116 described later as a center. It is an output ring having a protrusion 115c for transmitting the revolution and transmitting the rotation to a cam ring (not shown). The second connecting plate 11 is rotatably supported by the output ring 115.
The third roller is a third roller that is sandwiched between 4 and a manual connecting plate 117, which will be described later, and rolls to revolve around the optical axis. Reference numeral 117 denotes a manual connecting plate to which rotation is transmitted by a focus ring (not shown), which is pressed by a second pressing means described later and one end surface of which is brought into contact with the third roller 116.

The material of the manual connecting plate 117 is determined by the coefficient of friction between the third roller 116 and the second connecting plate 114, and the third roller 116 and the manual connecting plate 1
A material having a small friction coefficient between 17 is selected.

Reference numeral 118 is a holding ring which is pressed by a second pressing means which will be described later and abuts against the manual connecting plate 117, and is fitted to the unit main body so as to be restricted in rotation. Reference numeral 119 is a reinforcing plate for the retaining ring 118. Reference numeral 120 denotes a second pressing means, which is a second disc spring for urging the manual connecting plate 117 toward the third roller in the optical axis direction. Reference numeral 121 is a second nut that is screwed into a screw portion formed on the inner diameter of the unit support cylinder to adjust the pressure of the disc spring 120.

[0017]

However, in the conventional pressure-separation type drive unit, the pressure-separation unit (conventional pressure-separation unit for receiving the pressure from the vibration type motor side and the pressure from the manual ring side, respectively) has been used. For example, the first roller 112 and the second roller 1 which are lined up in the radial direction.
13) is arranged in parallel between the vibration type motor and the manual coupling part in the optical axis direction together with the third roller which is pivotally supported by the output ring and rolls, so that the thrust length of the unit is long. It had become.

An object of the first invention relating to the present application is to provide a drive device capable of shortening the thrust length of the drive unit while efficiently transmitting the output of the vibration type motor. A second object of the present invention is to provide a lens barrel in which a lens can be efficiently driven and a lens driving device can be efficiently arranged.

[0019]

A first structure for achieving the object of the first invention of the present application is to provide a first transmission member for frictionally transmitting a driving force from a vibration type motor to a first roller. , A second transmission member that frictionally transmits the driving force from the manual drive member to the first roller, and rolls by receiving a relative movement difference between the first transmission member and the second transmission member An output member that rotates integrally with the first roller; a first pressurizing unit that presses a friction transmission surface of the first transmission member against a contact surface with the first roller; and the second transmission. The second pressing means for pressing the friction transmission surface of the member against the contact surface with the first roller, and the pressing force of the second pressing means acting on the first roller are fixed on the apparatus main body side. Provided to the output member that receives to allow rotation of the output member between In the drive device, characterized in that a second roller.

A second configuration for achieving the object of the first invention according to the present application is the first configuration, wherein the friction torque between the second transmission member and the first roller is the first configuration. The drive device is characterized in that the friction torque between the first transmission member and the first roller is made smaller by setting the pressure of the second pressure means.

A third structure for achieving the object of the first invention according to the present application is the above-mentioned first or second structure, wherein the first transmission member, the second transmission member and the output member are A drive device is characterized in that it is formed in an annular shape rotatable about the same axis as the center of rotation.

A fourth construction for achieving the object of the first invention of the present application is the third construction, wherein the output member formed in an annular shape is provided with the first roller and the second roller. At least three or more rollers are provided in the radial direction, and the first roller and the second roller are arranged so that the phases thereof are different from each other.

A fifth structure for achieving the object of the first invention according to the present application is the vibration-type motor according to the first, second, third or fourth structure, which has an annular shape in which drive vibration is formed. According to another aspect of the present invention, there is provided a driving device including: a vibrator, a ring-shaped moving element that comes into contact with a driving surface of the vibrator, and a pressurizing unit that press-contacts the vibrator and the moving element.

A sixth structure for achieving the object of the first invention according to the present application is the above-mentioned fifth structure, wherein the pressurizing means of the vibration type motor also functions as the first pressurizing means. The drive device is characterized by the fact that

A seventh structure for achieving the object of the first invention of the present application is the structure of the second, third, fourth, fifth or sixth structure, wherein the first pressurizing means, the vibration type motor and the First
The transmission member, the output member, the second transmission member, and the second pressurizing means are arranged in series along the rotation axis direction.

A structure for realizing the second object of the present invention is a lens barrel characterized in that the above driving device is used for driving a lens, and a moving lens is driven by movement of the output member. .

[0027]

1 is a sectional view of a lens barrel showing an embodiment of the present invention.

Reference numeral 1 denotes a focusing lens group. Reference numeral 2 is a fixed lens group. A driving roller 3 holds the focusing lens group 1 and engages with a guide tube 5 and a cam tube 6 described later.
It is the 1st group lens-barrel which has a. Reference numeral 4 denotes a second group lens barrel that holds the fixed lens group 2 described above, and is integrally held by a guide tube 5 described later.

Reference numeral 5 is a guide tube for slidably supporting the first group lens barrel 3 in the optical axis direction, and a pawl 5a for rotatably restricting movement of the cam ring 6 described later in the optical axis direction, It has a straight advance groove 5b with which the driving roller 3a is engaged.

Reference numeral 6 has a cam 6a which is engaged with the guide cylinder 5 by the pawl 5a so as to be rotatable only, and with which the driving roller 3a of the first group lens barrel 3 is engaged. It is a cam ring having a protrusion 6b for engaging the output ring 21 of the unit and transmitting the rotation.

A diaphragm unit 7 is held by the above-mentioned second group lens barrel 4. Reference numeral 8 denotes a fixed cylinder to which a mount described later is integrally attached and which holds the guide cylinder 5 described above and a unit support cylinder 11 of the focus drive unit described later. Reference numeral 9 denotes a focus operation ring, which is rotatably held by a unit support cylinder 11 of a focus drive unit described later, and transmits the rotation to a manual connection plate 24 of the focus drive unit described later via a connection claw 9a. A mount 10 is mounted on the fixed barrel 8 and mechanically coupled to a camera body (not shown).

Reference numerals 11 to 28 are parts constituting the focus drive unit, and 11 is a unit support cylinder for holding each component of the focus drive unit, which is held by the fixed cylinder 8 described above. Reference numeral 12 denotes an annular vibration member (hereinafter referred to as a stator) having a trapezoidal cross section. 1
Reference numeral 3 is an electrostrictive element that is joined to one end surface of the stator 12 to vibrate. Reference numeral 14 is an annular vibration absorber made of felt or the like that is pressed against the surface of the electrostrictive element 13. Reference numeral 15 is a first pressing means, which is a first disc spring for urging the vibration absorber in the optical axis direction. Reference numeral 16 is a first nut that is screwed into a screw portion formed on the inner diameter of the unit support cylinder to adjust the pressing force of the disc spring 15, and is an optimum pressurization that maximizes the performance of the vibration motor. Is adjusted. 17
Is integrally held on the inner diameter of the unit body,
It is a detent for restricting the rotation of the stator 12.
Reference numeral 18 denotes a rotating body (hereinafter referred to as a rotor) that receives a rotational force about the optical axis by the stator 12.

Reference numeral 20 denotes a rotor 18 via a rubber ring 19.
Is a connecting plate that rotates integrally with and is brought into contact with a first roller described later. Reference numeral 21 has a plurality of shafts 21 a and 21 b extending substantially equally in the radial direction with respect to an optical axis that rotatably supports a first roller 22 and a second roller 23, which will be described later, and rotates on the cam ring 6. Is an output ring having a protrusion 21c for transmitting the. Reference numeral 22 denotes a first shaft that is pivotally supported by a plurality of shafts 21a arranged on the output ring 21, is sandwiched between a connecting plate 20 and a manual connecting plate 24, which will be described later, and rolls to revolve around the optical axis.
Is a roller.

A plurality of shafts 23 are arranged on the output ring 21.
1b, which receives a pressure from a second pressure means, which will be described later, which is axially supported by a manual coupling plate, which will be described later, via a first roller 22 and an output ring 21, so that It is a second roller that is urged toward the end surface, and has a structure in which the inner diameter side and the outer diameter side are split into two parts and connected by bearing balls in order to eliminate loss. The second
The rollers 23 are arranged at the same position on the output ring 21 in the optical axis direction so as not to interfere with the first roller 22, but are arranged in a different phase in the radial direction (the first roller 22).
It is located above).

Reference numeral 24 denotes a manual connecting plate to which rotation is transmitted from the focus operating ring 9, which is pressed by a second pressing means which will be described later, and one end surface of which is brought into contact with the first roller. The material of the manual connecting plate 24 is selected such that the friction coefficient between the first roller 22 and the manual connecting plate 24 is smaller than the friction coefficient between the first roller 22 and the connecting plate 20. .

Reference numeral 25 is a holding ring which is pressed by a second pressing means which will be described later and abuts against the manual connecting plate 24, and is fitted to the unit supporting cylinder so as to be restricted in rotation. Reference numeral 26 is a reinforcing plate of the retaining ring 25. Reference numeral 27 denotes a second pressurizing means, which moves the manual connecting plate 24 in the first direction in the optical axis direction.
2 is a second disc spring that biases the roller toward the roller. Two
Reference numeral 8 is a second nut that is screwed into a threaded portion formed on the inner diameter of the unit body to adjust the pressure of the disc spring 27, and slip torque due to frictional contact between the first roller 22 and the connecting plate 20. In the smaller range, the first roller 2
It is adjusted with a pressure larger than that of the first pressurizing means so that the slip torque due to the frictional contact between 2 and the end surface of the manual connecting plate 24 is maximized.

Next, the operation of the lens barrel in which the focus drive unit having the above structure is arranged will be described.

When the user of the lens barrel operates the focusing switch of the camera (not shown) in the auto focus mode, the electrostrictive element of the vibration type motor is operated through the printed board (not shown) by the operation of the control circuit (not shown). A voltage is applied to the stator 13, and as a result, vibration that advances in the circumferential direction is generated in the stator 12, and the vibration of the stator 12 causes the rotor 1 to vibrate.
8, the rubber ring 19, and the connecting plate 20 are rotated about the optical axis.

Due to this rotation, the first roller 22 receives a rotational torque, but at this time, the manual connecting plate 24
Does not rotate, the first roller 22 rolls along the end face of the manual coupling plate 24 while rotating around the shaft 21a on the output ring, and the output ring 21 also rotates about the optical axis via the shaft 21a. Rotate. As a result, the cam ring 6 is driven via the projection 6b, and the first group lens barrel is driven in the optical axis direction accordingly, and autofocusing is performed.

On the other hand, when the lens barrel user manually performs focusing, if the focus operating ring 9 is rotated without operating the focusing switch (not shown), the rotation is transmitted to the manual connecting plate 24.
At that time, since the vibration type motor unit is not driven, the connecting plate 20 is stationary, and the first roller 22 is rotated around the shaft 21a on the output ring, and along the end surface of the connecting plate 20. It rolls and the output ring 21 also rotates around the optical axis via the shaft 21a. As a result, the cam ring 6 is driven via the protrusion 6b, and the first group lens barrel is driven in the optical axis direction accordingly, and manual focusing is performed.

In the above embodiment, the friction coefficient between the first roller 22 and the manual connection plate 24 is smaller than the friction coefficient between the first roller and the connection plate 20 as the material of the manual connection plate 24. Although the manual connection plate is made of the same material as the connection plate, the coefficient of friction between the first roller and the connection plate 20 and the connection between the first roller 22 and the manual connection plate 24 have been described. When the friction coefficients are equal, the second nut for adjusting the second pressing force is set to the first value within a range smaller than the slip torque due to the frictional contact between the first roller 22 and the connecting plate 20.
It is sufficient to adjust the slip torque due to the frictional contact between the roller 22 of FIG.

(Correspondence between Invention and Embodiment) In the above embodiment, the output ring 21 is the first member of the present invention.
The roller 22 of the present invention is the first roller of the present invention, the second roller 23 of the present invention is the second roller of the present invention, the connecting plate 20 is the first transmitting member of the present invention, and the manual connecting plate 24 is the present invention. The second transmission member includes the first disc spring 15 and the first nut 16, and the first pressurizing means of the present invention includes the retaining ring 25, the reinforcing plate 26, the second disc spring 27, and the second nut. 28 corresponds to the second pressing means of the present invention.

The above is the correspondence relationship between each configuration of the present invention and each configuration of the embodiments, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims or It goes without saying that any structure may be used as long as the functions of the structure of the embodiment can be achieved.

For example, in the present invention, the vibration type motor described in the above embodiments is not limited to the annular type, but may be a rod type or linearly driven type. .

Further, the present invention is not limited to autofocus, but may be applied to drive a zoom lens.

[0046]

According to the invention of claims 1 to 7, it is possible to set the friction torque for automatic drive and the friction torque for manual drive individually without the need for switching operation between automatic and manual. In the pressure separation type driving device, since the second roller of the pressure separation mechanism is provided in the output member, the device can be made compact, and particularly when the respective elements constituting the device are arranged in series, the arrangement direction The length of can be shortened.

Further, since the slip torque of the frictional contact between the first roller and the second transmission member can be set by the pressurization adjustment of the second pressurizing means, the slip torque is greatly adjusted by this pressurization adjustment. The width can be adjusted (within a range smaller than the slip torque of the frictional contact between the first transmission member and the first roller).

Further, the conventional pressure separating mechanism as shown in FIG. 2 requires two types of rollers only for pressure separation, whereas the present invention requires only one type of the second roller. Also, the cost can be reduced.

According to the eighth aspect of the present invention, the lens barrel can be downsized, and the manual operation can be performed reliably and efficiently without switching the automatic operation such as autofocus. It can be carried out.

[Brief description of drawings]

FIG. 1 is a sectional view of a lens barrel showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a focus unit used in a conventional lens barrel.

[Explanation of symbols]

1 ... Focus lens group 2 ... Fixed lens group 3 ... 1st group lens barrel 4 ... 2nd group lens barrel 5 ... Guide tube 6 ... Cam ring 7 ... Aperture unit 8 ... Fixed tube 9 ... Focus operation ring 10 ... Mount 11 ... Unit support cylinder 12 ... Stator 13 ... Electrostrictive element 14 ... Vibration absorber 15 ... First disc spring 16 ... First nut 17 ... Rotation stop 18 ... Rotor 19 ... Rubber ring 20 ... Connection plate 21 ... Output ring 22 ... 1st roller 23 ... 2nd roller 24 ... Manual connection plate 25 ... Retaining ring 26 ... Reinforcement plate 27 ... 2nd disc spring 28 ... 2nd nut

Claims (8)

[Claims] 1. A first transmission member for frictionally transmitting a driving force from a vibration type motor to a first roller, and a second transmission member for frictionally transmitting a driving force from a manual driving member to the first roller.
Of the first transmission member, an output member that rotates integrally with the first roller that rolls in response to a relative movement difference between the first transmission member and the second transmission member, and A first pressing unit that presses the friction transmission surface against the contact surface with the first roller, and a second pressing unit that presses the friction transmission surface of the second transmission member against the contact surface with the first roller. Provided to the output member, which receives the pressing force of the second pressing device acting on the first roller so as to allow the rotation of the output member between the fixing unit on the apparatus body side and the pressing member. And a second roller that is set. 2. The friction torque between the second transmission member and the first roller according to claim 1,
The driving device is characterized in that the friction torque between the first transmission member and the first roller is set smaller by setting the pressure of the pressure means. 3. The first transmission member, the second transmission member, and the output member according to claim 1 or 2, wherein the first transmission member, the second transmission member, and the output member are formed in an annular shape rotatable about the same axis. Characteristic drive device. 4. The output member formed into an annular shape according to claim 3, wherein the first roller and the second roller are provided at least at three or more locations in a radial direction, and the first roller and the first roller are provided. A driving device, wherein the second roller and the second roller are arranged so as to have different phases in the radial direction. 5. The vibrating motor according to claim 1, 2, 3, or 4, wherein the vibrator has a ring-shaped vibrator in which drive vibration is formed, and a ring-shaped mover that abuts a driving surface of the vibrator. And a pressurizing means for pressurizing and contacting the vibrator and the mover. 6. The drive device according to claim 5, wherein the pressurizing means of the vibration type motor also serves as the first pressurizing means. 7. The method according to claim 2, 3, 4, 5, or 6,
The first pressurizing means, the vibration type motor, the first transmitting member, the output member, the second transmitting member and the second pressurizing means are arranged in series along the rotational axis direction. A drive device characterized in that 8. A lens barrel, wherein the driving device according to claim 1 is used for driving a lens, and a moving lens is driven by movement of the output member.