JP2020134912A - Lens drive device - Google Patents

Abstract

To provide a lens drive device with which the transmission of an external force to an oscillatory wave motor is suppressed.SOLUTION: A lens drive device 10 comprises a moving member 12, an oscillatory wave motor 100 provided with a guide mechanism 115, a connecting part 16 for connecting to the oscillatory wave motor 100 and provided in the moving member 12, a guide shaft 13b, at least one rolling member 15, and a restricting part 17b. The displacement of the moving member 12 is restricted due to the fact that the rolling member 15 or the restricting part 17b comes in contact with the guide shaft 13b, and the connecting part 16 restricts rotation of the oscillatory wave motor 100 around the guide mechanism 115, the connecting part 16 being equipped with an urging member 16b that generates an urging force B2. The oscillatory wave motor 100 and the moving member 12 do not relatively move when an external force F to the moving member 12 is greater than or equal to a first force F1, the oscillatory wave motor 100 and the moving member 12 relatively move when the external force F exceeds the first force F1 but does not exceed a second force F2, and the relative movement is restricted by the restricting part 17b when the external force F exceeds the second force F2.SELECTED DRAWING: Figure 4

Description

The present invention relates to a lens driving device provided in a lens barrel of a digital camera or the like and driving a lens by using a vibration wave motor.

In recent years, a lens driving device having a small driving load has attracted attention for the purpose of improving the accuracy of focusing operation and saving power of an actuator. For the purpose of reducing the rotational load of the actuator when the weight of the lens is large, an optical device in which the frictional force is reduced by contacting the lens holding frame with the guide plate via a bearing has been proposed.

JP-A-2017-015799

However, in Patent Document 1, when a large external force such as a drop impact is applied, the lens holding frame is largely displaced with respect to the guide plate. Therefore, there is a problem that the external force is transmitted to the connecting portion between the lens holding frame and the actuator and the actuator itself, and the actuator itself is damaged.

An object of the present invention is to provide a lens driving device that suppresses transmission of an external force to a vibration wave motor.

The lens driving device of the present invention includes a moving member, a vibration wave motor provided with a guide mechanism, a connecting portion provided on the moving member and connected to the vibration wave motor, a guide shaft, and at least one rolling member. The rolling member or the regulating portion abuts on the guide shaft to regulate the displacement of the moving member, and the connecting portion rotates around the guide mechanism of the vibration wave motor. The connecting portion is provided with an urging member that generates an urging force, and when the external force on the moving member is equal to or less than the first force, the vibration wave motor and the moving member do not move relative to each other. When the external force exceeds the first force and does not exceed the second force, the vibration wave motor and the moving member move relative to each other, and when the external force exceeds the second force, the relative movement is said. It is characterized by being regulated by the regulatory department.

It is possible to provide a lens driving device that suppresses the transmission of an external force to a vibration wave motor.

It is a block diagram of the lens driving device 10 which concerns on 1st Example. (A) It is sectional drawing which shows the drive mechanism of the lens drive device 10 which concerns on 1st Example. (B) is a cross-sectional view showing the structure of the connecting portion 16. It is sectional drawing which shows the structure of the vibration wave motor 100 which concerns on (A), (B) 1st Example. It is a schematic diagram which shows the operation when the external force F is generated in the lens driving device 10 which concerns on 1st Examples (A)-(D). (A)-(C) It is a schematic diagram which shows the operation of the connecting part 16 when an external force F is generated in the lens driving device 10 which concerns on 1st Example. It is a flowchart which shows the control sequence of the vibration wave motor 100 which concerns on 1st Example. (A) It is sectional drawing which shows the drive mechanism of the lens drive device 20 which concerns on 2nd Example. (B) is a schematic view showing a rolling member 25.

(First Example)
The lens driving device 10 including the vibration wave motor (ultrasonic motor) 100 according to the first embodiment of the present invention will be described. In the drawings, the driving movement direction of the vibration wave motor 100 is the X direction, the pressurizing direction is the Z direction, and the directions orthogonal to the X direction and the Z direction are the Y directions.

FIG. 1 is a block diagram of the lens driving device 10 of the present invention, in which the optical axis Oa is shown by a chain line. The lens driving device 10 is composed of a lens barrel 1 including an optical element 2 which is a part of a photographing optical system and a vibration wave motor 100 for driving the optical element 2, and a camera body 3 having an image pickup element 4. The camera body 3 includes the focus detecting means 5, the focus state of the image formed on the image sensor 4 is detected by the focus detecting means 5, and the signal is input to the control means 7. Further, the lens barrel 1 includes a position detecting means 6, the current position of the optical element 2 is detected by the position detecting means 6, and the signal is input to the control means 7. Based on these signals, the control means 7 outputs a signal to the vibration wave motor driving means 8 to drive the vibration wave motor 100. With this configuration, the optical element 2 is driven to the target position by the vibration wave motor 100, the focus shift can be corrected, and a good image can be taken.

Next, the configuration of the drive mechanism for driving the optical element 2 by the vibration wave motor 100 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a cross-sectional view showing a driving mechanism of the lens driving device 10 according to the first embodiment as viewed from the direction of the optical axis Oa of the optical element 2, and the configuration of the vibration wave motor 100 is simplified. It is shown as 2 (B) is a cross-sectional view showing the configuration of the connecting portion 16 in the cross-sectional line IIB-IIB of FIG. 2 (A).

The fixing member 11 has a substantially tubular shape and is fixed to the lens barrel 1. The fixing member 11 holds a vibration wave motor 100, and a guide shaft 13 including a first guide shaft 13a and a second guide shaft 13b, which will be described later, respectively.

The moving member 12 is a member that holds the optical element 2 and moves relative to the fixing member 11 in the direction of the optical axis Oa. A round hole 12a is formed in the moving member 12 so as to penetrate the first guide shaft 13a, and a shaft portion 12b for holding the rolling member 15 described later and a connecting portion connected to the connecting portion 16 described later. 12c is provided.

The guide shaft 13 is composed of a first guide shaft 13a and a second guide shaft 13b, and is a member that guides the relative movement of the moving member 12. The first guide shaft 13a is a rod-shaped member that comes into contact with the moving member 12 via the round hole 12a, that is, a main guide bar. The first guide shaft 13a regulates the parallel movement of the moving member 12 in the direction orthogonal to the optical axis Oa. The second guide shaft 13b is a rod-shaped member that comes into contact with the moving member 12 via the rolling member 15, that is, a sub guide bar. The second guide shaft 13b regulates the rotational movement of the moving member 12 about the first guide shaft 13a.

The rolling member 15 is a member having a rolling mechanism inside such as a ball bearing, is held by a shaft portion 12b provided on the moving member 12, and abuts on a second guide shaft 13b. The moving member 12 is guided by the first guide shaft 13a and the second guide shaft 13b so as to translate in the direction of the optical axis Oa. Further, the inner ring side of the rolling member 15 is integrated with the moving member 12 via the shaft portion 12b, and the outer ring side is in contact with the second guide shaft 13b without slip, so that between the moving member 12 and the second guide shaft 13b. It is possible to reduce the frictional force generated in. However, if the moving member 12 and the second guide shaft 13b are separated from each other, the moving member 12 cannot be accurately guided in the direction of the optical axis Oa. In order to prevent this separation, the urging means 14 causes the urging force B1 so that the moving member 12 abuts on the second guide shaft 13b by the urging means 14 such as a spring whose one end is fixed to the fixing member 11. Occurs.

As shown in FIG. 2B, the connecting portion 16 is composed of an engaging member 16a having a protruding portion 16p and an urging member 16b, and connects the moving member 12 and the vibration wave motor 100. The urging member 16b is a member such as a compression spring that has elasticity and generates an urging force B2 in the direction of the optical axis Oa. Then, the urging member 16b urges the engaging member 16a in the direction of the optical axis Oa so that the engaging member 16a and the second holding housing 108 described later, which is a constituent member of the vibration wave motor 100, are not loosened. Connect. The protrusion 16p engages with the groove 108b formed in the second holding housing 108. As shown in FIG. 2A, the groove portion 108b is formed in an elongated hole shape, and normally, the movement of the engaging member 16a is guided in the longitudinal direction (Y direction) of the elongated hole.

The regulation unit 17 is composed of a first regulation unit 17a and a second regulation unit 17b. Since the first regulation unit 17a is provided in the second holding housing 108, the details will be described later. The second regulating portion 17b is a portion provided on either the moving member 12 or the fixing member 11, and in this embodiment, the second regulating portion 17b is formed in a protruding shape or the like as a part of the moving member 12. When an external force F, which will be described later, is applied to the moving member 12, and the moving member 12 tries to move in a direction in which the rolling member 15 and the second guide shaft 13b are separated from each other, the second regulating portion 17b and the second guide shaft 13b The amount of displacement can be regulated by the contact between the two. Although it is assumed that it is a part of the moving member 12 in this embodiment, a second regulating portion 17b may be provided on the fixing member 11 and abut on the moving member 12, and the rolling member 15 and the second guide may be provided. It suffices to have a function of regulating the amount of movement of the moving member 12 in the direction in which the shaft 13b is separated.

With the above-described configuration, the driving force generated by the vibration wave motor 100 is transmitted to the moving member 12 via the connecting portion 16. As a result, the moving member 12 is guided in the direction of the optical axis Oa by the guide shaft 13 and the rolling member 15, and a configuration is realized in which the moving member 12 moves relative to the fixed member 11.

Next, the configuration of the vibration wave motor 100 will be described with reference to FIGS. 3A and 3B. FIG. 3A is a cross-sectional view of the vibration wave motor 100 in the XZ plane, and FIG. 3B is a cross-sectional view of the vibration wave motor 100 in the YZ plane.

The vibration wave motor 100 includes an oscillator 101, a friction member 104, a fixed-side holding housing 105, a movable-side holding housing 106, a pressurizing means 110, a guide mechanism 115, and the like. The guide mechanism 115 is configured to guide the vibrator 101 so that it can move relative to the friction member 104, and to allow the movable portion 119, which will be described later, to rotate about the guide mechanism 115. The driving direction of the vibration wave motor 100 is the guiding direction (X direction).

The vibrator 101 is formed by adhering a diaphragm 102 and a piezoelectric element 103. The diaphragm 102 is formed with two protrusions 102p and two fixing portions 102a for fixing to the first holding housing 107, which will be described later, along the longitudinal direction. Further, a power feeding member (not shown), which is a flexible substrate, is electrically connected to the piezoelectric element 103. Then, when a high-frequency voltage having a frequency in the ultrasonic region having a specific amplitude and phase difference is applied to the piezoelectric element 103 from the feeding member, the diaphragm 102 is deformed and an elliptical motion is generated in the protrusion 102p.

The friction member 104 is a member that makes frictional contact with the vibrator 101 and is fixed to the fixed side holding housing 105. When a high-frequency voltage is applied to the vibrator 101 and the protrusion 102p moves in an elliptical manner, a frictional force is intermittently generated between the vibrator 101 and the friction member 104, and the vibrator 101 moves relative to the friction member 104 in the X direction ( Thrust in the direction of the optical axis Oa) is generated. Due to this thrust, the movable side holding housing 106 moves relative to the fixed side holding housing 105.

The fixed-side holding housing 105 is a member that holds the friction member 104 and the first guide member 116, and is a roughly plate-shaped member that is fixed to a lens barrel 1 (not shown). The fixed side holding housing 105 is provided with a fastening hole 105a, and the friction member 104 and the first guide member 116 are fastened to the fastening hole 105a by the fastening member 105b and held.

The movable side holding housing 106 is composed of a first holding housing 107, a second holding housing 108, and a thin plate 109, and has a function of holding the vibrator 101. The first holding housing 107 has two protrusions 107a along the longitudinal direction, and each of them engages with the fixing portion 102a of the vibrator 101 to hold the vibrator 101. Further, as described above, the first regulating portion 17a is provided, and when the vibrator 101 and the friction member 104 move in a direction other than the X direction in which the vibrator 101 and the friction member 104 move relative to each other due to an external force F or the like, they come into contact with the movable side holding housing 106. Restricts the movement of the movable portion 119. The second holding housing 108 holds the second guide member 117, which will be described later. Further, as described above, the elongated hole-shaped groove portion 108b is provided and engages with the protrusion portion 16p of the connecting portion 16. The thin plate 109 is a member having elasticity having low rigidity in the Z direction, which is the pressurizing direction of the pressurizing means 110 described later, and high rigidity in the X direction and the Y direction, and the first holding housing 107 and the second holding housing 107. The holding housing 108 is connected. With this configuration, even if the contact state of the vibrator 101 and the friction member 104 varies due to the component variation of each member, the thin plate 109 is deformed to absorb this variation, maintain a stable contact state, and achieve high efficiency. Can generate thrust.

The guide mechanism 115 is a mechanism for guiding the vibrator 101 so as to move relative to the friction member 104, and is composed of a first guide member 116, a second guide member 117, and a rolling element 118, and is composed of light. It extends in a direction parallel to the axis Oa. The rolling element 118 is composed of two spherical members 118a and 118b, and is held by the first guide member 116 and the second guide member 117.

The first guide member 116 has a fastening hole 116a, and is fastened to and held by the fixing side holding housing 105 by the fastening member 105b, so that the first guide member 116 does not move relative to the friction member 104. Further, the first guide member 116 has a V groove 116b and comes into contact with the two spherical members 118a and 118b.

The second guide member 117 has an engaging portion 117c that engages with the pressurizing means 110 described later, and by engaging with the pressurizing means 110, the Z direction, which is the pressurizing direction of the pressurizing means 110. Be urged to. Further, the second guide member 117 is a member that is integrated with the movable side holding housing 106 and moves relative to the fixed side holding housing 105. Further, the second guide member 117 has two V-grooves 117a and 117b, each of which comes into contact with the spherical members 118a and 118b.

As shown in FIG. 3A, the spherical member 118a is sandwiched between the V groove 116b provided in the first guide member 116 and the V groove 117a provided in the second guide member 117. Further, the spherical member 118b is sandwiched between the V groove 116b provided in the first guide member 116 and the V groove 117b provided in the second guide member 117. The V-groove 116b included in the first guide member 116 regulates the rolling element 118 so that it can move only in the X direction of relative movement, and similarly, the second guide member 117 can move only in the X direction of relative movement. Is regulated by. Further, when the rolling element 118 rolls, the first guide member 116 and the second guide member 117 can move relative to each other with low friction. Further, since the first guide member 116 and the second guide member 117 are configured to be rotatable about the rolling element 118 when viewed from the X direction (direction of the optical axis Oa), the vibrator 101 is also integrated in the same manner. It can rotate as.

As shown in FIG. 3B, since the groove 108b is formed so that the longitudinal direction of the groove 108b is the normal direction of the circle centered on the guide mechanism 115, the protrusion 16p is the second holding casing. The vibration wave motor 100 is regulated in the Z direction by engaging with the groove portion 108b of the body 108. That is, the connecting portion 16 connects the moving member 12 and the vibration wave motor 100, and regulates the rotation of the vibrator 101 around the guide mechanism 115. From the above configuration, since the second guide member 117 is guided in the X direction of relative movement with respect to the first guide member 116, the movable side holding housing 106 moves relative to the fixed side holding housing 105. You will be guided in the X direction of.

The pressurizing means 110 is composed of a first transmission member 111, a second transmission member 112, a third transmission member 113, and an elastic member 114, and is a pressurizing mechanism for pressurizing the vibrator 101 against the friction member 104. is there. The elastic member 114 is a spring that generates a pressing force for bringing the vibrator 101 into frictional contact with the friction member 104, and four elastic members 114 are arranged in this embodiment. The number of elastic members 114 is not limited to this. One end of the elastic member 114 engages with the holding portion 111a of the first transmission member 111, and the other end engages with the engaging portion 117c of the second guide member 117 as described above. , The first transmission member 111 and the second guide member 117 are pressurized in the Z direction so as to approach each other. The first transmission member 111 has a holding portion 111a that holds the elastic member 114, and transmits the pressing force to the second transmission member 112. The second transmission member 112 has an arc portion 112a that comes into contact with the first transmission member 111, and transmits the pressing force to the third transmission member 113. Since the arc portion 112a and the first transmission member 111 come into contact with each other, the pressing force can be efficiently transmitted even when the directions of contact vary due to manufacturing variations. The third transmission member 113 is a member having elasticity that easily absorbs vibration, is arranged so as to be sandwiched between the vibrator 101 and the second transmission member 112, and the vibration from the vibrator 101 propagates to other members. Prevent from doing. In the Z direction, which is the pressurizing direction, the first transmission member 111, the second transmission member 112, the third transmission member 113, the oscillator 101, the friction member 104, the first guide member 116, the rolling element 118, and the first The guide members 117 of 2 are laminated and pressurized. From the above configuration, the pressing force of the elastic member 114 is efficiently transmitted via the transmission member, and the vibrator 101 is brought into frictional contact with the friction member 104.

In the vibration wave motor 100, a thrust is generated between the vibrator 101 and the friction member 104 by a high frequency voltage applied by a feeding member (not shown), and the movable side holding housing 106 that holds the vibrator 101 is a fixed side holding housing. It moves relative to the body 105. Further, the thrust is transmitted to the moving member 12 via the connecting portion 16 and drives the optical element 2 in the direction of the optical axis Oa (X direction of relative movement).

Next, the operation when a large external force F, which is a feature of the present invention, is generated will be described with reference to FIGS. 4 (A) to 4 (D) and FIGS. 5 (A) to 5 (C). 4 (A) to 4 (D) are schematic views showing the operation of the moving member 12 when a large external force F is generated. The oscillator 101, the movable side holding housing 106, the pressurizing means 110, and the second guide member 117, which are movable parts inside the vibration wave motor 100, are schematically shown as the movable portion 119. Further, the first regulating portion 17a is schematically shown as a member that regulates the movement of the movable portion 119. 5 (A) to 5 (C) are schematic views showing the operation of the connecting portion 16 when a large external force F is generated.

When an external force F due to a drop impact or the like is applied to the lens driving device 10, an inertial force is generated in the moving member 12 to try to move the moving member 12 in a direction orthogonal to the optical axis Oa. At this time, depending on the direction in which the external force F is generated, the moving member 12, the connecting portion 16, and the movable portion 119 operate as follows.

First, when the external force F is generated in the right direction (+ Y direction) or downward direction (−Z direction) of the moving member 12 when viewed from the direction of the optical axis Oa, the moving member 12 is moved as shown in FIG. 4 (A). A counterclockwise moment M1 that rotates around the first guide shaft 13a is generated. At this time, the reaction force R1 is generated by the contact between the rolling member 15 and the second guide shaft 13b, and the moving member 12 does not rotate around the first guide shaft 13a.

Next, when the external force F is generated in the left direction (−Y direction) or the upward direction (+ Z direction) of the moving member 12 when viewed from the direction of the optical axis Oa, the moving member 12 is as shown in FIG. 4 (B). Is generated around the first guide shaft 13a, and a clockwise moment M2 is generated. The external force F is shown to act upward on the moving member 12 in FIGS. 4 (B) to 4 (D). Since the moving member 12 moves in the direction in which the rolling member 15 and the second guide shaft 13b are separated from each other by this external force F, the reaction force R1 from the rolling member 15 as shown in FIG. 4A is not generated. .. However, the urging force B1 acts on the rolling member 15 by the urging means 14, and the component force of the external force F in the direction facing the urging force B1 is reduced by the urging force B1. Then, if the component force of the external force F is smaller than the urging force B1, the moving member 12 does not rotate around the first guide shaft 13a.

Next, a case where the external force F is very large and the rolling member 15 and the second regulating portion 17b are released from contact with each other by the urging force B1 of the urging means 14 will be described. As shown in FIG. 4C, when the moving member 12 tries to rotate around the first guide shaft 13a due to an excessive external force F, the external force F also acts on the connecting portion 16 and causes the vibration wave motor 100. Be transmitted. At this time, the moving member 12, the connecting portion 16, and the movable portion 119 are integrally moved so as to rotate in the direction of the clockwise moment M2. However, since the movable portion 119 is guided by the guide mechanism 115 so that it can rotate about the guide mechanism 115, the movable portion 119 first comes into contact with the first regulating portion 17a. When the external force F is a predetermined force of the first force or less (F1 or less), the movement of the moving member 12 is restricted only by the reaction force R2 received from the first regulating unit 17a. As shown in FIG. 5A, the engaging member 16a of the connecting portion 16 does not displace in a state of being urged by the urging force B2 of the urging member 16b. That is, the vibration wave motor 100 does not move relative to the moving member 12 in a state of being connected by the connecting portion 16.

Next, when the external force F exceeds the first force F1, the protrusion 16p is displaced so as to be separated from the groove 108b as shown in FIG. 5 (B), the urging member 16b is compressed, and the urging force B2 is generated. It becomes the increased urging force B2'. However, in the range where the external force F exceeds the first force F1 and does not exceed the second force F2 which is a predetermined force, the protrusion 16p is displaced from the groove 108b but does not deviate from the groove 108b. That is, since the protrusion 16p is displaced, the vibration wave motor 100 moves relative to the moving member 12.

Then, when the external force F becomes larger and exceeds the second force F2, the external force F acting on the connecting portion 16 also becomes larger, and the protrusion 16p is displaced so as to ride on the groove 108b as shown in FIG. 5C. Then, the urging member 16b is compressed to become an urging force B2 in which the urging force B2 is increased. As shown in FIG. 4D, the vibration wave motor 100 moves relative to the moving member 12, but described above. As the engaging member 16a of the connecting portion 16 is displaced so as to ride on the groove portion 108b, the moving member 12 further moves in the direction of the moment M2, and the second regulating portion 17b provided on the moving member 12 Abuts on the second guide shaft 13b, a reaction force R3 is generated, and the movement of the moving member 12 is restricted.

With such a configuration, when an excessive external force F is generated due to a drop impact or the like, the rolling member 15, the urging member 16b, the first regulating portion 17a, or the second regulating portion 17b is used to move the moving member. The rotation around the first guide shaft 13a of the twelve can be regulated. Further, it is possible to suppress the transmission of an impact to the vibration wave motor 100 by moving the protrusion 16p of the connecting portion 16 with respect to the vibration wave motor 100, and prevent the vibration wave motor 100 from being damaged. The first force F1 is the urging force B2 (the urging force B2 before being compressed) in which the urging member 16b urges the engaging member 16a, and the second force F2 has the protrusion 16p in the groove. The urging force B2 ”is generated by the urging member 16b immediately before the 108b is ridden and dropped off.

From the above, when the external force F other than the direction of the optical axis Oa applied to the connecting portion 16 is equal to or less than the first force F1, the moving member 12 is directed in the direction orthogonal to the direction of the optical axis Oa by the first regulating portion 17a. Movement is restricted. Further, when the external force F other than the direction of the optical axis Oa applied to the connecting portion 16 exceeds the first force F1 and does not exceed the second force F2, the urging member 16b makes the direction orthogonal to the direction of the optical axis Oa. Movement is restricted. Further, when the external force F applied to the connecting portion 16 in a direction other than the direction of the optical axis Oa exceeds the second force F2, the movement in the direction orthogonal to the direction of the optical axis Oa is restricted by the second regulating portion 17b. Will be done. Further, the first force F1 and the second force F2 are determined by the urging force B2 of the urging member 16b.

Next, a control method of the lens driving device 10 will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the lens driving device 10, and shows from the start of the focusing operation to the end of the focusing operation.

In step S1, the focus detecting means 5 detects the focus state of the image imaged on the image sensor 4, the signal is input to the control means 7, and the moving member 12 calculates and updates the target position to be moved. To do. In step S2, the position detecting means 6 detects the position of the moving member 12 included in the lens driving device 10, and the signal is input to the control means 7 to update the current position. In step S3, the difference between the target position updated in step S1 and the current position updated in step S2 is calculated, energization of the vibration wave motor 100 is determined, and a signal is input to the vibration wave motor driving means 8. In step S4, the vibration wave motor 100 is driven based on the input difference, and the moving member 12 is driven. In step S5, it is determined whether or not the operation is stopped, and if it is not stopped, the process returns to step S1 and the control is continued so that the difference between the target position and the current position of the moving member 12 disappears.

Next, the effect of the present invention will be described. In the optical device disclosed in Patent Document 1, the frictional force is reduced by bringing the lens holding frame and the guide plate into contact with each other via a bearing. However, in this configuration, when the lens holding frame moves in the direction orthogonal to the guide plate due to a force such as a drop impact, the displacement amount is large and the impact may be transmitted to the actuator.

On the other hand, in the lens driving device 10 of the present invention, in the mechanism for guiding the optical element 2 in the direction of the optical axis Oa, the frictional force between the guide shaft 13 and the moving member 12 is reduced to improve the stopping accuracy and save the actuator. It becomes possible to electrify. When the external force F applied to the moving member 12 is equal to or less than the first force F1, the first regulating portion 17a provided inside the vibration wave motor 100 moves the moving member 12 in the direction orthogonal to the optical axis Oa. Movement is restricted. When the external force F applied to the moving member 12 exceeds the first force F1 and does not exceed the second force F2, the urging member 16b regulates the movement of the moving member 12 in the direction orthogonal to the optical axis Oa. At the same time, the protrusion 16p of the connecting portion 16 is displaced from the groove portion 108b to separate the vibration wave motor 100 and the moving member 12, so that the transmission of the external force F to the vibration wave motor 100 is suppressed. When the external force F applied to the moving member 12 exceeds the second force F2, the movement of the moving member 12 in the direction orthogonal to the optical axis Oa of the moving member 12 is restricted by the second regulating unit 17b. At the same time, the protrusion 16p of the connecting portion 16 is separated from the groove portion 108b to separate the vibration wave motor 100 and the moving member 12, so that the transmission of the external force F to the vibration wave motor 100 is suppressed.

Based on the above configuration, the lens driving device 10 that uses the vibration wave motor 100 to guide rolling is provided with the lens driving device 10 that suppresses the transmission of the external force F to the vibration wave motor 100 when a large external force F is applied. be able to.

(Second Example)
The lens driving device 20 including the vibration wave motor 100 in the second embodiment of the present invention will be described. The same members as those in the first embodiment will be designated by the same numbers, and the description thereof will be omitted, and only the members different from those in the first embodiment will be described. Further, the configuration of the vibration wave motor 100 and the control method of the lens driving device 20 will be omitted because they are the same as those in the first embodiment.

Next, the configuration of the drive mechanism for driving the optical element 2 with the vibration wave motor 100 will be described with reference to FIGS. 7A and 7B. FIG. 7A is a cross-sectional view showing the driving mechanism of the lens driving device 20 according to the second embodiment when the optical element 2 is viewed from the direction of the optical axis Oa, and the configuration of the vibration wave motor 100 is simplified. It is shown as Further, FIG. 7B is a diagram showing a first guide shaft 23a and rolling members 25a, 25b, 25c, 25d, which will be described later, as viewed from a direction orthogonal to the optical axis Oa. The description of the fixing member 21 and the moving member 22 which are the same as those in the first embodiment will be omitted.

The guide shaft 23 is composed of a first guide shaft 23a and a second guide shaft 23b, and is a member that guides the relative movement of the moving member 22. The first guide shaft 23a is a rod-shaped member that comes into contact with the moving member 22 via the rolling member 25, that is, a main guide bar. The first guide shaft 23a regulates the parallel movement of the moving member 22 in the direction orthogonal to the optical axis Oa. The second guide shaft 23b is a rod-shaped member that comes into contact with the moving member 22 via the rolling member 25, that is, a sub guide bar. The second guide shaft 23b regulates the rotation of the moving member 22 around the first guide shaft 23a.

The rolling member 25 is a member having a rolling mechanism inside such as a ball bearing, and hits the rolling members 25a, 25b, 25c, 25d and the second guide shaft 23b that come into contact with the first guide shaft 23a. It is composed of rolling members 25e in contact with each other. Further, the rolling members 25a, 25b, 25c, 25d and 25e are held by the shaft portions 22a, 22b, 22c, 22d and 22e provided on the moving member 22, respectively. Then, the rolling members 25a, 25b, 25c, and 25d are brought into contact with the first guide shaft 23a by an urging means (not shown). Further, a rotational moment is applied around the first guide shaft 23a, and the rolling member 25e is urged to the second guide shaft 23b.

The moving member 22 is guided by the first guide shaft 23a and the second guide shaft 23b so as to translate in the direction of the optical axis Oa. Further, the inner ring side of the rolling member 25 is integrated with the moving member 22, and the outer ring side is in contact with the guide shaft 23 without slipping, so that the frictional force generated between the moving member 22 and the guide shaft 23 can be reduced.

The regulation unit 27 is composed of a first regulation unit 27a and a second regulation unit 27b. Since the first regulation unit 27a is provided in the vibration wave motor 100 as in the first embodiment, the details will be omitted. The second regulating portion 27b is a portion provided on either the moving member 22 or the fixing member 21, and in this embodiment, the second regulating portion 27b is formed in a protruding shape or the like as a part of the moving member 22. When an external force F is applied to the moving member 22 and the moving member 22 tries to move in a direction in which the rolling member 25 and the guide shaft 23 are separated from each other, the regulating portion 27 and the guide shaft 23 come into contact with each other to reduce the displacement amount. Can be done. Here, although it is assumed that it is a part of the moving member 22 in this embodiment, the regulating portion 27 may be provided on the fixing member 21 and abut on the moving member 22, and the rolling member 25 and the guide shaft 23 may be in contact with each other. It suffices to have a function of regulating the amount of movement of the moving member 22 in the direction of separation.

With the above-described configuration, the driving force generated by the vibration wave motor 100 is transmitted to the moving member 22 via the connecting portion 26. As a result, the moving member 22 is guided in the direction of the optical axis Oa by the guide shaft 23 and the rolling member 25, and a configuration is realized in which the moving member 22 moves relative to the fixed member 21.

The effects of this embodiment include the same effects as those of the first embodiment, as well as the excellent effects described below. Since the frictional force can be further reduced as compared with the first embodiment, the effects of improving the stopping accuracy and saving power can be obtained. Further, in this embodiment, the number of rolling members 25a to 25d that come into contact with the first guide shaft 23a is four, but the number of rolling mechanisms may be replaced with two rolling mechanisms having V grooves formed in the outer ring. And shape are not limited.

Regarding the operation when the external force F is generated, only the rotation around the first guide shaft 13a is described in the first embodiment, but in the second embodiment, the first guide shaft 23a and the second guide shaft are described. Since both 23b are separated from each other, parallel movement also occurs. However, since the other relationships are the same as those in the first embodiment, the description thereof will be omitted.

2 Optical elements 10, 20 Lens driving devices 11, 21 Fixing members 12, 22 Moving members 13a, 23a First guide shaft (guide shaft)
13b, 23b Second guide shaft (guide shaft)
15, 25 Rolling member 16, 26 Connecting part 16a Engaging member 16b Biasing member 16p Projection part 17a, 27a First regulation part (regulation part)
17b, 27b Second Regulatory Department (Regulatory Department)
100 Vibration wave motor 101 Oscillator 104 Friction member 108b Groove 115 Guide mechanism 118 Rolling body 119 Moving parts B1, B2 Biasing force F External force F1 First force F2 Second force Oa Optical axis

Claims (10)

With moving members
A vibration wave motor equipped with a guidance mechanism and
A connecting portion provided on the moving member and connected to the vibration wave motor,
Guide axis and
With at least one rolling member
With a regulatory department,
The displacement of the moving member is regulated by the rolling member or the regulating portion abutting on the guide shaft.
The connecting portion regulates the rotation of the vibration wave motor around the guide mechanism.
The connecting portion includes an urging member that generates an urging force.
When the external force on the moving member is equal to or less than the first force, the vibration wave motor and the moving member do not move relative to each other.
When the external force exceeds the first force and does not exceed the second force, the vibration wave motor and the moving member move relative to each other.
A lens driving device, characterized in that, when the external force exceeds the second force, the relative movement is regulated by the regulating unit. With moving members
Fixing member and
A vibration wave motor equipped with a guidance mechanism and
A connecting portion provided on the moving member and connected to the vibration wave motor,
Guide axis and
With at least one rolling member
With a regulatory department,
The moving member includes at least one rolling member, holds an optical element, and moves relative to the fixing member in the direction of the optical axis of the optical element.
The connecting portion regulates the rotation of the vibration wave motor around the guide mechanism.
The connecting portion includes an urging member that generates an urging force.
The guide shaft guides the relative movement of the moving member.
The regulatory unit includes a first regulatory unit and a second regulatory unit.
The vibration wave motor includes the first regulation unit.
Either the moving member or the fixing member includes the second regulating portion.
The movement of the moving member in the direction orthogonal to the direction of the optical axis is
When the external force on the moving member is equal to or less than the first force, it is regulated by the first regulating unit.
When the external force exceeds the first force and does not exceed the second force, it is regulated by the urging member.
A lens driving device characterized in that when the external force exceeds the second force, it is regulated by the second regulating unit. The guide mechanism includes two rolling elements so that the movable portion of the vibration wave motor can rotate about the guide mechanism, and the axis is in a direction parallel to the optical axis. The lens driving device according to claim 1 or 2. The lens driving device according to any one of claims 1 to 3, wherein the first force and the second force are determined by the urging force of the urging member. The connecting portion does not move the vibration wave motor and the moving member relative to each other in the driving direction and the pressurizing direction of the vibration wave motor, but is orthogonal to the driving direction and the pressurizing direction of the vibration wave motor. The lens driving device according to any one of claims 1 to 4, wherein the vibration wave motor and the moving member are relatively moved. The connecting portion includes an engaging member having a protrusion.
The vibration wave motor includes a groove with which the engaging member is engaged.
The lens drive according to any one of claims 1 to 5, wherein the groove portion has a shape of an elongated hole in a direction orthogonal to the drive direction and the pressurization direction of the vibration wave motor. apparatus. The lens driving device according to claim 6, wherein the groove portion is formed in the normal direction of a circle centered on the guide mechanism. Any one of claims 1 to 7, wherein the guide shaft includes a first guide shaft and a second guide shaft, and the second guide shaft regulates the movement of the moving member. The lens drive device according to the section. The method according to any one of claims 1 to 8, wherein the vibration wave motor is composed of a vibrator and a friction member, and the guide mechanism guides the vibrator with respect to the friction member. Lens drive device. The lens driving device according to any one of claims 1 to 9, wherein the vibration wave motor is an ultrasonic motor that vibrates at a frequency in the ultrasonic region.

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