JP4739357B2 - DRIVE DEVICE, IMAGING DEVICE HAVING THE SAME, AND IMAGING DEVICE - Google Patents

Description

  The present invention relates to a driving device, an imaging device including the driving device, and an imaging device.

  Conventionally, a driving device for driving a driven body using an electromechanical conversion element (piezoelectric element) has been proposed. Such a driving device is used for driving a lens in an optical device such as a photographing lens of a camera.

  Conventional techniques in this field include, for example, the following conventional examples A and B.

  Conventional Example A is an invention related to a driving device including a piezoelectric element that can be expanded and contracted in the driving direction (optical axis direction) of a lens barrel and a driving member connected to one end of the piezoelectric element. Or it is disclosed by patent document 2. FIG. In Conventional Example A, the drive member is frictionally engaged with the lens barrel. Then, due to the expansion and contraction of the piezoelectric element in the optical axis direction, a frictional force is generated between the drive member and the lens barrel, and the lens barrel is driven in the optical axis direction by the frictional force.

  FIG. 37 is an explanatory diagram for explaining the configuration of the driving device of the conventional example A. As shown in FIG. 37, the driving device of the conventional example A includes a piezoelectric element 301, a rod-shaped driving member 302, a lens barrel (driven body) 304, a lens 3011, an imaging element 3012 such as a CCD, and a circuit board 3013. These members are housed in a housing 306.

  A piezoelectric element 301 is connected to one end of the driving member 302. The lens barrel (driven body) 304 is frictionally engaged with the driving member 302.

  In addition, a lens 3011 is fitted in the lens barrel 304, and an image sensor 3012 is disposed below the lens barrel 304. The image sensor 3012 is fixed to the circuit board 3013 by soldering or the like.

  In the drive device shown in FIG. 37, since the piezoelectric element 301 expands and contracts in the direction of the arrow, the drive member 302 is driven in the optical axis direction. As a result, the lens barrel 304 that is frictionally engaged with the drive member 302 is driven in the optical axis direction.

  Another conventional example B is an invention relating to an actuator in which a plurality of piezoelectric elements are connected to a mirror, and is disclosed in, for example, Patent Document 3. In Conventional Example B, the mirror is tilted in a desired direction by electrically controlling the bending of the plurality of piezoelectric elements.

  Moreover, as a drive device using a piezoelectric element, in addition to the above Patent Documents 1 to 3, for example, Patent Document 4 or Patent Document 5 discloses.

The inventions disclosed in Patent Documents 4 and 5 are inventions related to a driving device including a piezoelectric element that can expand and contract in the driving direction (optical axis direction) of the lens barrel and a driving member connected to one end of the piezoelectric element. is there. In Patent Documents 4 and 5, a frictional force is generated between the drive member and the lens barrel due to expansion and contraction of the piezoelectric element in the optical axis direction, and the lens barrel is driven in the optical axis direction by the frictional force. It has become. Japanese Patent Application Laid-Open No. H10-228688 describes a drive device including a preload spring that applies a preload in a direction perpendicular to the extending direction of the piezoelectric element to the lens barrel.
Japanese Patent Laid-Open No. 4-69070 (published March 4, 1992) JP 7-298656 A (published on November 10, 1995) JP 2003-209981 A (published July 25, 2003) JP 2007-74890 A (published March 22, 2007) Japanese Patent No. 3171022 (registered on March 23, 2001)

  However, the conventional examples A and B have the following problems.

  That is, in the driving device of the conventional example A, the piezoelectric element 301 is connected to one end of the driving member 302 in the optical axis direction, and the expansion / contraction direction of the piezoelectric element 301 and the driving direction of the lens barrel 304 coincide with each other. Yes. For this reason, the drive member 302 and the piezoelectric element 301 are configured in parallel (stacked) in the drive direction, and there is a problem that it is difficult to reduce the height of the drive device.

  Further, the conventional example B has a problem that the drive amount of the mirror is limited to the displacement amount of the piezoelectric element.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a drive device that can realize a low profile, an imaging device including the same, and an imaging device.

  In order to solve the above-described problems, the drive device of the present invention is a drive device including a drive mechanism that drives a driven body, and the drive mechanism is partially fixed, and is flexibly displaced by electrical control. Is coupled to the bending displacement member, and is in contact with the driven body and converts the displacement direction to a direction different from the bending displacement direction of the bending displacement member to drive the driven body. A drive direction conversion member is provided.

  According to the above configuration, when the bending displacement of the bending displacement member is excited by electrical control, the driving direction conversion member connected to the bending displacement member is also bent, and the driving direction conversion member is distorted or bent. appear. Then, due to the distortion or bending of the drive direction changing member, the drive direction changing member moves in a plane perpendicular to the bending displacement direction so as to be in contact with the driven body. In the above configuration, the driven body converts the displacement direction (drive direction) into a direction different from the bending displacement direction by the movement of the drive direction conversion member. That is, the drive direction conversion member has a function as conversion means for converting the bending displacement direction of the bending displacement member into the driving direction of the driven body.

  In the conventional drive device, the expansion / contraction direction of the piezoelectric element as the drive source and the drive direction of the driven body are the same, so the dimensions of the drive device in the drive direction are the dimensions in the drive direction of the driven body. And the sum of the dimensions of the piezoelectric element in the driving direction. Therefore, the conventional drive device has a problem that it is difficult to reduce the height of the drive device.

  However, according to the above configuration, the conventional problem does not occur. That is, according to the above configuration, the drive direction conversion member contacts the driven body by the bending displacement of the bending displacement member, and the displacement direction of the driven body is changed to a direction different from the bending displacement direction of the bending displacement member. (The driving direction of the driven body is different from the bending displacement direction of the bending displacement member as the driving source), so that the dimension in the driving direction of the driving device is the driving of the bending displacement member. It becomes possible to determine only the dimension in the direction. Therefore, according to the above configuration, it is possible to design the size of the driving device in the driving direction smaller than that of the conventional driving device, and it is possible to realize a reduction in the height of the driving device.

  The drive device of the present invention includes a first bending displacement member that bends in the first bending displacement direction and a second bending displacement member that bends in the second bending displacement direction as the bending displacement member. The drive direction conversion member may be configured to drive the driven body in a direction different from the first and second bending displacement directions.

  Thereby, the dimension in the driving direction of the driving device can be determined in consideration of only the dimension in the driving direction of the first and second bending displacement members.

  In the driving device of the present invention, the connecting portion between the first bending displacement member and the driving direction changing member is a first connecting portion, and the connecting portion between the second bending displacement member and the driving direction changing member is the connecting portion. When the first straight line in the direction perpendicular to the drive direction of the driven body is drawn in a plane including the first and second connection portions of the drive direction conversion member as the second connection portion, the first and second It is preferable that the 2nd connection part is distribute | arranged so that the virtual line which connects these connection parts may cross | intersect the said 1st straight line.

  According to the above configuration, when the bending displacement of the first and second bending displacement members is excited by electrical control, the driving direction conversion member coupled to the first and second bending displacement members is also bent, The first and second connecting portions are displaced. And according to said structure, when the 1st straight line of the direction perpendicular | vertical to the drive direction of a to-be-driven body is drawn in the surface containing a 1st and 2nd connection part, a 1st and 2nd connection part Since the imaginary line connecting the first and second lines intersects with the first straight line, the displacement of the imaginary line according to the displacement of the first and second connecting portions is efficiently driven by the driving direction conversion member. It becomes possible to convert into the displacement of a contact part with a body.

  In the drive device of the present invention, the connecting portion between the first bending displacement member and the driving direction changing member is the first connecting portion, and the connecting portion between the second bending displacement member and the driving direction changing member is the connecting portion. When the second connecting portion is a second straight line that is perpendicular to the plane including the first and second connecting portions, the contact portion where the driving direction changing member contacts the driven body is the first connecting portion. It is preferable that they are arranged so as to pass through a straight line.

  According to said structure, since the said contact part is distribute | arranged so that it may pass along a perpendicular | vertical straight line with respect to the surface containing the 1st and 2nd connection part, it includes the said 1st and 2nd connection part. It is possible to efficiently convert the displacement of the surface into the displacement of the contact portion with the driven body, and the relatively small bending displacement of the first and second bending displacement members can reduce the contact portion with the driven body. Displacement can be realized.

  In the driving device of the present invention, the first and second bending displacement members draw a straight line connecting any one point on the first bending displacement member and any one point on the second bending displacement member. In this case, it is preferable that at least one straight line passing through the driven body exists among these straight lines.

  According to the above configuration, the first and second bending displacement members draw a straight line connecting any one point on the first bending displacement member and any one point on the second bending displacement member. Are arranged such that at least one of the straight lines passing through the driven body is present, that is, the driven body is placed in a space surrounded by the first and second bending displacement members. Since it is arranged, the space in the housing can be effectively used.

  In particular, when the first and second bending displacement members and the housing capable of accommodating the driving direction conversion member are provided and the housing has a prismatic shape including a rectangular parallelepiped, the first and second bending Each of the displacement members is arranged along two adjacent sidewalls among the plurality of sidewalls forming the prism shape, and a part of the driven body is formed by the first and second bending displacement members. It is preferable that the structure be arranged in a fan-shaped space (a space formed when the first and second bending displacement members are opened in a fan shape).

  The first and second bending displacement members may be arranged such that their bending displacement directions are orthogonal to each other.

  The drive device of the present invention includes a housing that can accommodate the first and second bending displacement members and the drive direction conversion member, the housing has a prismatic shape, and the first and second The bending displacement member is arranged along two side wall surfaces adjacent to each other among the plurality of side walls forming the prismatic shape, and the driving direction changing member is a corner formed by the two side wall surfaces. It is preferable to be arranged in the part.

  According to the above configuration, since the driving direction changing member is arranged in the corner portion having a space, the space in the housing can be effectively used for the arrangement of the driving mechanism, and the driving device can be downsized. become.

  In the drive device according to the present invention, the casing has a prismatic shape, and the first and second bending displacement members are arranged along only one of the plurality of sidewalls forming the prismatic shape. It may be arranged.

  According to the above configuration, the first and second bending displacement members are arranged along only one side wall among the plurality of side walls forming the prismatic shape. The internal space can be effectively used more efficiently.

  The drive device of the present invention includes a first drive circuit that drives a voltage to the first bending displacement member, and a second drive circuit that drives a voltage to the second bending displacement member, and the first and second Preferably, the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are different from each other. .

  In particular, the drive device of the present invention includes a first drive circuit that drives a voltage to the first bending displacement member, and a second drive circuit that drives a voltage to the second bending displacement member, Control means for controlling the bending displacement of the second bending displacement member is provided, and the driving voltage waveform driven by the first driving circuit and the driving voltage waveform driven by the second driving circuit have different phases from each other. Preferably it is.

  According to the above configuration, the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit have different phases from each other. The bending displacement directions of the displacement member can be opposite to each other. Therefore, the contact portion of the driven body in the friction member can be efficiently displaced in a direction different from the bending displacement direction.

  In the drive device of the present invention, the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit may be 90 degrees out of phase with each other.

  According to the above configuration, the driving voltage waveform driven by the first driving circuit and the driving voltage waveform driven by the second driving circuit are out of phase with each other by 90 degrees. The contact portion of the driven body can be elliptically driven in a direction different from the bending displacement direction.

  In the driving device of the present invention, the driving voltage waveform driven by the first driving circuit and the driving voltage waveform driven by the second driving circuit may be 180 degrees out of phase with each other.

  According to the above configuration, the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are 180 degrees out of phase with each other. The contact portion of the driven body can be arc-driven in a direction different from the bending displacement direction.

  The drive device of the present invention is a third connection portion that is connected to the drive direction conversion member on a second imaginary line that passes through the first connection portion and is parallel to a direction perpendicular to the drive direction of the driven body. A third bending displacement member comprising: a third bending displacement member connected to the drive direction conversion member on a third imaginary line passing through the second connection portion and parallel to a direction perpendicular to the drive direction of the driven body. The structure provided with the 4th bending displacement member provided with 4 connection parts may be sufficient.

  Further, the above configuration includes the first drive circuit that drives the voltage to the first bending displacement member and the second drive circuit that drives the voltage to the second bending displacement member. Control means for controlling the bending displacement of the bending displacement member, and the third bending displacement member is connected to the first drive circuit and driven in the same phase as the voltage driven by the first bending displacement member. The fourth bending displacement member is preferably connected to the second drive circuit and driven in the same phase as the voltage driven by the second bending displacement member.

  According to the above configuration, the third bending displacement member is connected to the first drive circuit, driven in the same phase as the voltage driven by the first bending displacement member, and the fourth bending displacement member. Is connected to the second drive circuit and driven in the same phase as the voltage driven by the second bending displacement member, so that the bending displacement of the bending displacement member is converted into the displacement in the driving direction of the driven body. In this case, there is an advantageous effect that displacement in an unnecessary direction can be suppressed.

  In the driving apparatus of the present invention, it is preferable that the driving apparatus includes a preload elastic member that biases the driven body against the driving direction conversion member, and a control unit that controls the bending displacement of the bending displacement member.

  The control means applies an alternating electrical signal to the bending displacement member, and the basic frequency of the alternating signal is the elasticity of the preload elastic member and the resonance frequency of the resonance phenomenon in the preload direction due to the mass of the driven body. Preferably they are different.

  According to the above configuration, when the alternating signal having the fundamental frequency is applied to the bending displacement member, the drive direction changing member vibrates at the fundamental frequency. Since the vibration component in the preload direction of the drive direction changing member vibrates at a fundamental frequency different from the resonance frequency of the preload elastic member, the resonance phenomenon in the preload direction is not excited. Thereby, the contact state of the drive direction conversion member and the driven body can be stabilized without the driven body vibrating in the preload direction. As a result, according to the above configuration, it is possible to realize a preload mechanism in which the frictional force acting between the driving direction changing member and the driven body is stable and the driving speed of the driven body is stable.

  In particular, when the driving direction conversion member drives the driven body by converting the displacement direction to a direction different from the bending displacement direction of the bending displacement member as in the above configuration, the driving direction conversion member is not limited to the driving direction. Since the vibration also occurs in the preload direction, the vibration component in the preload direction significantly affects the driving of the driven body. For this reason, the frictional force acting between the driving direction changing member and the driven body is likely to be unstable, and the driving speed and thrust of the driven body are unstable.

  According to the above configuration, since the fundamental frequency of the alternating signal is different from the resonance frequency of the resonance phenomenon in the preload direction, the vibration component in the preload direction of the driving direction conversion member is the resonance frequency of the preload elastic member. Since it vibrates at different fundamental frequencies, the resonance phenomenon in the preload direction is not excited. Thereby, the contact state of the drive direction conversion member and the driven body can be stabilized without the driven body vibrating in the preload direction.

  Note that the cause of the resonance phenomenon in the preload direction can be considered according to the design of the driving device and the properties of various members. As an example, the resonance phenomenon caused by the elasticity of the preload elastic member and the mass of the driven body can be given. It is done.

  In the driving apparatus of the present invention, it is preferable that the basic frequency of the alternating signal is higher than the resonance frequency of the resonance phenomenon in the preload direction.

  According to said structure, since the fundamental frequency of the said alternating signal is larger than the resonance frequency of the resonance phenomenon of the said preload direction, management of the preload by a preload elastic member becomes easy.

  In the driving device of the present invention, the resonance frequency of the resonance phenomenon in the preload direction is the resonance frequency of the resonance phenomenon in the driving direction caused by the mass of the driven body, the elasticity of the bending displacement member, and the elasticity of the driving direction conversion member. It is preferable to be smaller.

  Setting the basic frequency of the alternating signal near the resonance frequency of the resonance phenomenon in the drive direction can increase the vibration amplitude (in the drive direction) compared to driving at a frequency other than the resonance frequency. become. According to the above configuration, the resonance frequency of the resonance phenomenon in the preload direction is the resonance frequency of the resonance phenomenon in the driving direction caused by the mass of the driven body, the elasticity of the bending displacement member, and the elasticity of the driving direction conversion member. Therefore, if the basic frequency of the alternating signal is set near the resonance frequency of the resonance phenomenon in the driving direction, the basic frequency of the alternating signal becomes higher than the resonance frequency of the resonance phenomenon in the preload direction.

  Therefore, according to the above configuration, the driving device is effective for low-voltage driving and high-speed driving, and pre-load management by the pre-load elastic member is facilitated.

  In the driving device of the present invention, it is preferable that the preload elastic member biases the driven body in a direction not passing through the center of the driven body as viewed from the upper side in the driving direction.

  According to said structure, the spring natural length of an elastic preload member can be ensured largely, and a spring constant can be made small. As a result, the resonance frequency of the resonance phenomenon in the preload direction due to the elasticity of the preload elastic member and the mass of the driven body can be surely made smaller than the fundamental frequency (the fundamental frequency is surely It becomes higher than the resonance frequency of the resonance phenomenon in the preload direction).

  In the drive device according to the present invention, it is preferable that the drive device includes a housing having a side wall surrounding the side surface of the driven body, and the preload elastic member is disposed along the side wall. The side surface of the driven body here means a side surface when the two surfaces in the driving direction of the driven body are the top surface and the bottom surface.

  According to the above configuration, since the preload elastic member is disposed along the side wall, the spring natural length of the elastic preload member can be ensured to be large and the installation space for the preload elastic member can be minimized. . Therefore, the space in the housing can be effectively used for installing the preload elastic member.

  In the driving device of the present invention, the bending displacement member is disposed along the side wall, and the preload elastic member is disposed perpendicular to the bending displacement member when viewed from the upper side in the driving direction. preferable.

  Thereby, the space in a housing | casing can be used effectively for installation of a preload elastic member.

  In the driving apparatus of the present invention, it is preferable that the preload elastic member is a helical spring having one end fixed to the driven body.

  According to the above configuration, when the driven body is driven and displaced (moved) in the optical axis direction, the one end of the preload elastic member is also displaced. The preload elastic member bends in the optical axis direction and follows the driven body while the driven body is driven. Therefore, the preload elastic member has a small elastic spring constant in the optical axis direction. Therefore, when the preload elastic member bends in the optical axis direction and follows the driven body, the load on the driven body can be sufficiently reduced.

  It is preferable that the preload elastic member is provided with a sliding member that slides a driven body with respect to the preload elastic member.

  According to said structure, since a sliding member slides a to-be-driven body with respect to a preload elastic member, the member (preload elastic member, sliding member) for preload is not added to the mass of a drive direction. Therefore, the vibration in the driving direction caused by the mass of the driven body, the elasticity of the bending displacement member, and the elasticity of the driving direction changing member is not affected by the “mass of the member for preload”. Therefore, according to the above configuration, the resonance frequency of the resonance phenomenon in the driving direction can be dramatically increased. This produces an effect of increasing the difference between the resonance frequency of the resonance phenomenon in the driving direction and the resonance frequency of the resonance phenomenon in the preload direction.

  In the driving device of the present invention, the resonance frequency of the resonance phenomenon in the preload direction caused by the elasticity of the preload elastic member and the mass of the driven body and the sliding member is the mass of the driven body, the bending displacement member. It is preferable that the resonance frequency is lower than the resonance frequency of the resonance phenomenon in the drive direction due to the elasticity and the elasticity of the drive direction conversion member.

  The resonance frequency of the resonance phenomenon in the preload direction decreases as the mass of the member causing the resonance phenomenon increases. According to said structure, since a sliding member slides a to-be-driven body with respect to a preload elastic member, while the member for preload (preload elastic member, sliding member) is not added to the mass of a drive direction, It is added to the mass in the preload direction. Therefore, according to the above configuration, the resonance frequency of the resonance phenomenon in the preload direction can be further reduced.

  The drive device of the present invention may have a configuration in which only one bending displacement member is provided, and the end of the driving direction conversion member opposite to the connection portion with the bending displacement member is a free end.

  According to the above configuration, the end of the driving direction conversion member on the side opposite to the connecting portion with the bending displacement member is not connected to other members but is a free end, so that the bending displacement member is bent. When displaced, the displacement width of the other end of the driving direction changing member is not limited by connection / support with other members. As a result, the vibration amplitude of the contact portion with the driven body is not reduced, and the driving efficiency of the driven body is improved. Furthermore, the bonding process for fixing the other bending displacement member to the end of the driving direction conversion member opposite to the connecting portion with the bending displacement member becomes unnecessary, and the number of assembly steps of the driving device can be reduced.

  Moreover, in the drive device of the present invention, it is preferable that a mass increasing member is provided at the end of the drive direction conversion member opposite to the connecting portion with the bending displacement member.

  According to said structure, since the mass increase member is provided in the edge part on the opposite side to the connection part with a bending displacement member in the said drive direction conversion member, the mass of the said free end of a drive direction conversion member is It becomes larger than the mass of the connecting portion with the bending displacement member. As a result, the vibration amplitude at the free end of the drive direction conversion member increases, the displacement amplitude of the contact portion with the driven body increases, and the drive efficiency improves.

  The mass increasing member also has an effect of reducing the resonance frequency of the driving direction changing member. This effect is beneficial, for example, in a configuration in which the resonance frequency of the bending displacement member is smaller than the resonance frequency of the elastic member. Specifically, since the mass increasing member is provided at the free end of the driving direction conversion member, the resonance frequency of the driving direction conversion member can be reduced and can be close to the resonance frequency of the bending displacement member. And the drive efficiency of a to-be-driven body can be improved using the resonance phenomenon of a drive direction conversion member.

  Moreover, in the drive device of the present invention, it is preferable that a mass increasing member is provided in a connecting portion of the drive direction conversion member with the bending displacement member.

  According to said structure, since the mass increase member is provided in the connection part with the bending displacement member in the said drive direction conversion member, the mass of the connection part with the drive direction conversion member in a bending displacement member is the It becomes larger than the mass of the opposite end. Thereby, the vibration amplitude of the bending displacement member increases. That is, the amplitude for exciting the drive direction changing member increases. As a result, the vibration amplitude of the drive direction conversion member increases, the displacement amplitude of the contact portion with the driven body increases, and the driving efficiency is improved.

  The mass increasing member also has an effect of reducing the resonance frequency of the bending displacement member. This effect is beneficial, for example, in a configuration in which the resonance frequency of the bending displacement member is higher than the resonance frequency of the elastic member. Specifically, the resonance frequency of the bending displacement member is reduced and brought closer to the resonance frequency of the driving direction conversion member by providing a mass increasing member at the connecting portion of the driving direction conversion member with the bending displacement member. be able to. And the drive efficiency of a to-be-driven body can be improved using the resonance phenomenon of a bending displacement member.

  In the driving device of the present invention, it is preferable that a mass increasing member is provided on the bending displacement member.

  The above configuration also has the effect of improving the driving efficiency of the driven body and reducing the resonance frequency of the bending displacement member.

  In the driving device of the present invention, it is preferable that the mass increasing member is formed integrally with the driving direction changing member.

  In the driving apparatus of the present invention, it is preferable that the mass increasing member is formed as an extension portion in which the driving direction changing member extends to the opposite side to the connecting portion with the bending displacement member.

  Also in the above configuration, the resonance frequency of the bending displacement member can be brought close to the resonance frequency of the drive direction conversion member.

  In the drive device of the present invention, when the spring system includes the bending displacement member and the driving direction conversion member, the bending displacement member and the driving direction conversion member preferably have the same resonance frequency.

  According to the above configuration, the bending displacement member and the drive direction conversion member have the same resonance frequency. Therefore, if the control voltage is controlled so as to vibrate and displace at the resonance frequency of the bending displacement member, The vibration amplitude of the drive direction changing member is increased, the displacement amplitude of the contact portion with the driven body is increased, and the driving efficiency is improved.

  In particular, the above configuration is preferably used when the driven body needs to be driven by lowering the control voltage applied to the bending displacement member, and the vibration amplitude of the driving direction changing member cannot be sufficiently secured. Can do.

  Even when the bending displacement member and the driving direction conversion member have different resonance frequencies, the resonance frequency can be matched by providing the mass increasing member on either the bending displacement member or the driving direction conversion member. Is possible.

  Note that “match” means that the resonance frequency of the bending displacement member matches the resonance frequency of the drive direction change member within the tolerance of the bending displacement member to be attached to the driving device or the allowable limit of dimensional accuracy during manufacturing. It means that

  Further, in the driving device of the present invention, when the spring system is provided with the bending displacement member and the driving direction conversion member, the bending displacement member and the driving direction conversion member may be separated from each other in resonance frequency.

  According to the above configuration, the bending displacement member and the driving direction conversion member are separated from each other in the resonance frequency, so that even if the bending displacement member has a variation in the resonance frequency, the resonance of the driving direction conversion member is less affected. The variation in driving performance can be suppressed.

  Said structure is suitable when the drive direction conversion member is comprised with the plate-shaped member. In this case, the dimension management of the drive direction conversion member is facilitated, and the individual difference in the resonance frequency is reduced (the variation in the resonance frequency among the individual is small). And it can utilize suitably, when ensuring the amplitude of a bending displacement member enough and suppressing the dispersion | variation in drive performance.

  In addition, it is possible to control the difference between the resonance frequencies of each other by providing the mass increasing member on either the bending displacement member or the driving direction changing member.

  In the driving device of the present invention, a housing that can accommodate the bending displacement member and the driving direction conversion member is provided, and the bending displacement member is formed as a part of a side wall of the housing. preferable.

  Thereby, the space in the housing can be effectively used more efficiently.

  In the driving device of the present invention, it is preferable that the bending displacement member is arranged so that the bending displacement direction is perpendicular to the driving direction in which the driven body is driven.

  According to the above configuration, the driven body is driven in a direction perpendicular to the bending displacement direction of the bending displacement member (the optical axis direction for imaging the object). Therefore, for example, when the drive device of the present invention is applied to a drive device for an optical component in a small camera module, it is possible to adjust the drive of the optical component in the focus direction (focus adjustment mechanism).

  In the drive device of the present invention, the bending displacement member may include a piezoelectric material layer and a shim material. That is, in the driving device of the present invention, a piezoelectric element provided with a shim material can be used as the bending displacement member.

  In the drive device of the present invention, it is preferable that the bending displacement member includes a stack of two piezoelectric material layers.

  In the above configuration, the bending displacement member includes a stack of two piezoelectric material layers, and the shim material is removed. Therefore, according to the above configuration, the displacement amount of the bending displacement member can be increased as compared with the configuration using the piezoelectric element including the shim material as the bending displacement member. As the amount of bending displacement of the bending displacement member increases, the amount of displacement per pulse of the tip of the driving direction conversion member and the driven body can be increased. Furthermore, according to the above configuration, the proportion of the piezoelectric material layer in the bending displacement member is higher than that in the configuration using the piezoelectric element including the shim material as the bending displacement member. Therefore, according to the above configuration, the thickness of the piezoelectric material layer as the bending displacement member becomes thicker, and depolarization of the piezoelectric material layer can be prevented.

  The drive device of the present invention is a drive device for driving a lens barrel to which an objective lens is attached as the driven body, and the size of the bending displacement member in the driving direction of the driven body is the focus of the objective lens. The distance is preferably 2.5 times or less.

  The drive device of the present invention is a drive device for driving a lens barrel to which an objective lens is attached as the driven body, and the dimension of the bending displacement member in a direction perpendicular to the driving direction of the driven body is It is preferable that the diameter is not more than three times the diameter of the objective lens.

  As a result, it is possible to realize a driving device suitable for a small camera module for a mobile phone.

  In order to solve the above-described problems, an imaging apparatus of the present invention captures an image formed by the above-described driving apparatus and the objective lens that drives a lens barrel having an objective lens attached as the driven body. And an image sensor.

  As a result, it is possible to provide an imaging device that realizes a low-profile drive device.

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes the imaging device.

  As a result, it is possible to provide an imaging device that realizes a low-profile drive device.

  As described above, in the drive device of the present invention, the drive mechanism is partly fixed and connected to the bending displacement member that is excited by bending control by electrical control, and is connected to the bending displacement member. A driving direction conversion member that contacts the driving body and converts the displacement direction to a direction different from the bending displacement direction of the bending displacement member to drive the driven body is provided.

  In addition, an imaging apparatus according to the present invention includes the driving apparatus that drives a lens barrel to which an objective lens is attached as the driven body, and an imaging element that captures an image formed by the objective lens. is there.

  Moreover, the imaging device of this invention is the structure provided with the said imaging device.

  Therefore, it is possible to design the size of the driving device in the driving direction smaller than that of the conventional driving device, and to realize a reduction in the height of the driving device.

  The drive device of the present invention includes a bending displacement member and control means for electrically controlling the bending displacement of the bending displacement member. That is, in this drive device, the bending displacement of the bending displacement member is excited by electrical control by the control means. First, a bending displacement member in which bending displacement is excited by electrical control will be described. As an example of the bending displacement member, for example, a piezoelectric element having a bimorph structure shown in FIGS.

  FIG. 12 shows the configuration of a piezoelectric element having a bimorph structure, FIG. 12 (a) is a plan view, FIG. 12 (b) is a side view, and FIG. 12 (c) shows a bending displacement of the piezoelectric element. FIG.

  The piezoelectric elements shown in FIGS. 12A to 12C include two piezoelectric material layers 22X and 22Y and a shim material 21 made of metal, and the two piezoelectric material layers 22X and 22Y sandwich the shim material 21. It has a three-layer structure that is pressure-bonded. The two electrodes 20X and 20Y sandwich the three-layer structure. The two electrodes 20X and 20Y are connected to a control means (not shown). Then, one end of the shim material 21 is fixedly supported (“fixed point” indicated by black triangle marks in FIGS. 12B and 12C). In FIGS. 12A to 12C, the stacking direction of the three-layer structure including the piezoelectric material layers 22X and 22Y and the shim material 21 is the thickness direction, and in the plan view shown in FIG. The longitudinal direction of the element is the length direction, and the direction perpendicular to the length direction is the width direction. Further, in the thickness direction, the piezoelectric material layer 22X side is the X side, and the piezoelectric material layer 22Y side is the Y side.

  In the piezoelectric elements shown in FIGS. 12A and 12B, when a voltage is applied from the control means to the electrodes 20X and 20Y, the piezoelectric elements are bent and displaced in the thickness direction.

  For example, the piezoelectric material layer 22X shrinks when the voltage between the electrode 20X and the shim material 21 becomes positive, and expands when the voltage between the electrode 20X and the shim material becomes negative. Polarized. Further, the piezoelectric material layer 22Y expands when the voltage between the electrode 20Y and the shim material 21 becomes positive, and contracts when the voltage between the electrode 20Y and the shim material 21 becomes negative. Is polarized.

  A case where the control means applies a voltage to the piezoelectric material layers 22X and 22Y polarized as described above will be described. As shown in FIG. 12 (c), the control means applies a positive voltage between the electrodes 20X and 20Y and the shim material 21 (between “ai” in FIG. 12 (c)). Yes. And the part shown by the black triangle mark in the shim material 21 is being fixed. In this case, as shown in the figure, the piezoelectric element is bent and displaced in the thickness direction X side. On the other hand, although not shown, when the control means applies a negative voltage between the arrows, the piezoelectric element is bent and displaced in the thickness direction Y side.

  As described above, the piezoelectric element shown in FIGS. 12A to 12C is bent and displaced by voltage application by the control means. The bending displacement member in the driving device of the present invention is not limited to the piezoelectric element shown in FIGS. 12A to 12C, and has a structure capable of controlling the bending displacement by electrical control. If it is. For example, as the bending displacement member, a monomorph structure piezoelectric element composed of one piezoelectric material layer and a shim material can be cited. The monomorph structure piezoelectric element can be flexibly displaced by electrical control with the same operation concept as the bimorph structure piezoelectric element.

  As described above, the bending displacement member in the drive device of the present invention refers to a member that is bent and displaced by electrical control such as application of voltage, and of course, its structure and dimensions and shape such as thickness, length, and width. Is not limited to.

  Hereinafter, in order to simplify the description, a bending displacement member whose bending displacement is excited by electrical control is simply referred to as a “bending displacement member”.

  Further, in this specification, when the bending displacement member is disposed in the driving device, the moving direction of the driven body is referred to as the driven body moving direction or the width direction (of the bending displacement member), and the bending displacement member is bent. Direction to be bent is referred to as a bending direction or a thickness direction (of the bending displacement member), and a direction perpendicular to the driven body movement direction (the width direction) and orthogonal to the bending direction (thickness direction) is the length direction (of the bending displacement member) Call it. This is not affected by the size of the bending displacement member or the position of the fixing portion of the bending displacement member.

[First Embodiment]
An embodiment of the present invention will be described below with reference to FIGS. 1 (a), 1 (b) to 2 (a), (b). FIG. 1 shows a configuration of a drive device according to the present embodiment (hereinafter referred to as the present drive device), FIG. 1 (a) is a perspective view, and FIG. 1 (b) is an exploded perspective view. The driving device shown in FIGS. 1A and 1B shows an optimum embodiment applied to a focus adjustment mechanism of a small camera module.

  First, as shown in FIGS. 1 (a) and 1 (b), the present driving device includes bending displacement members 1A and 1B, an elastic member (driving direction converting member) 2, a friction member (driving direction converting member: contact). Part) 3, a lens barrel (driven body) 4, a guide shaft 5, a camera module housing 6, and drive circuits (control means) 7A and 7B.

  In the present drive device, the elastic member 2 connects the bending displacement member 1A and the bending displacement member 1B. The elastic member 2 is connected to a friction member 3 that frictionally engages the lens barrel 4.

  The “driving direction conversion member” refers to a member made up of the elastic member 2 and the friction member 3. In this drive device, the elastic member 2 and the friction member 3 are shown as separate members. However, in the present invention, as will be described later, the drive direction conversion member is not limited to a configuration in which the elastic member 2 and the friction member 3 are separate members.

  The bending displacement members 1A and 1B are bimorph piezoelectric elements having a three-layer structure in which the above-described two piezoelectric material layers are pressure-bonded with a shim interposed therebetween. Then, as shown in FIGS. 1A and 1B, one end of the bending displacement members 1A and 1B (extension of shim material in the present embodiment) is bonded or fitted into the camera module housing 6 or the like. It is fixed by. The other end is connected to the elastic member 2.

  The elastic member 2 is made of a material having a relatively low elastic modulus such as metal or resin. In the present drive device, the lens barrel 4 is moved in the optical axis direction when the friction member 3 comes into contact (friction engagement) with the lens barrel 4. Therefore, the material of the friction member 3 includes metal, resin, carbon and the like, and is selected according to a desired coefficient of friction with the lens barrel 4.

  Further, the drive device is provided with a guide shaft 5 for guiding the movement of the lens barrel 4 in the optical axis direction. The lens barrel 4 is provided with a hole through which the guide shaft 5 is inserted. The guide shaft 5 is a rod-like body extending in the optical axis direction, and is fixed to the bottom (or ceiling) of the camera module housing 6. Further, the guide shaft 5 has a role of supporting the lens barrel 4 so that the lens barrel 4 is positioned at a position where the friction member 3 and the lens barrel 4 are in contact (friction engagement). In the present drive device, the lens barrel 4 is moved along the guide shaft 5 in the optical axis direction by frictional engagement between the friction member 3 and the lens barrel 4. In the present driving device, the lens barrel 4 is not limited to one that is formed integrally with the hole through which the guide shaft 5 is inserted. The hole member including the hole portion may be separately bonded to the lens barrel. Further, the lens barrel 4 may have a configuration in which a friction adjustment member for obtaining a desired friction coefficient is connected (or attached) to a friction engagement portion with the friction member 3. That is, here, the lens barrel including the configuration including the hole member or the friction adjusting member is referred to as a lens barrel.

  The bending displacement members 1A and 1B are connected to the drive circuits 7A and 7B, respectively. The drive circuit 7A excites the bending displacement of the bending displacement member 1A by applying a voltage or the like to the bending displacement member 1A. The drive circuit 7B excites the bending displacement of the bending displacement member 1B by applying a voltage or the like to the bending displacement member 1B. The drive circuits 7A and 7B are controlled by an upper control circuit (not shown), and output a voltage corresponding to a drive waveform described later to the bending displacement members 1A and 1B. The “control means” means a drive circuit provided with drive circuits 7A and 7B and an upper control circuit.

  Note that the electrical control of the bending displacement of the bending displacement members 1A and 1B by the control means is not limited to the voltage control. For example, when a bimetal or a shape memory alloy is used as the bending displacement members 1A and 1B and the bending displacement is excited by heat, the electrical control of the bending displacement of the bending displacement members 1A and 1B is control by increasing or decreasing the current. . In this case, the temperature of the bending displacement members 1A and 1B is controlled by controlling the heat generated by a part of the bending displacement members 1A and 1B by increasing and decreasing the current flowing through the bending displacement members 1A and 1B. Alternatively, a heat generating means for generating heat by supplying a current composed of a heating wire such as a nichrome wire or a Kanthal wire is provided close to the bending displacement members 1A and 1B, and by increasing or decreasing the current flowing to the heat generating means The temperature of the bending displacement members 1A and 1B is controlled by controlling the heat generated by the heat generating means. In addition, for example, when a magnetostrictive element is used as the bending displacement member 1A or 1B and the bending displacement is excited by a magnetic field, a magnetic field generating means for generating a magnetic field by passing an electric current such as an electromagnet is provided to control increase / decrease of the current. Thus, the magnetic field applied to the bending displacement members 1A and 1B is controlled.

  Although not shown in FIGS. 1A and 1B, an optical component such as a lens is fitted in the lens barrel 4, and an image sensor such as a CCD is disposed at the bottom of the lens barrel 4. Has been.

  In the present driving device, the lens barrel 4 is driven along the guide shaft 5 by a driving mechanism including the bending displacement members 1 </ b> A and 1 </ b> B, the elastic member 2, and the friction member 3. As a result, the optical component fitted in the lens barrel 4 is driven in the optical axis direction, and focus adjustment is performed. In the present embodiment, the driven body moving direction in which the lens barrel 4 moves is treated as a synonym for the optical axis direction. In this specification, the direction in which the optical component fitted in the lens barrel 4 forms an object (the direction of a straight line connecting the lens barrel 4 and the object) is referred to as an “optical axis direction”.

  The camera module housing 6 is a member that accommodates the bending displacement members 1A and 1B, the elastic member 2, the friction member 3, the lens barrel 4, and the guide shaft 5. In the present drive device, the camera module housing 6 has a rectangular parallelepiped shape and includes side walls 6a to 6d. As shown in FIGS. 1A and 1B, the bending displacement members 1 </ b> A and 1 </ b> B are provided as part of the side wall of the camera module housing 6. That is, the bending displacement members 1 </ b> A and 1 </ b> B also serve as the side walls 6 c and 6 d of the camera module housing 6. The bending displacement members 1A and 1B include an arbitrary point on the bending displacement member 1A (for example, the point S shown in FIG. 2B) and an arbitrary point on the bending displacement member 1B (for example, FIG. 2B). ) Are arranged so that there is at least one straight line passing through the lens barrel 4 (for example, a straight line connecting the S point and the T point). Further, the elastic member 2 and the friction member 3 are arranged at a corner portion formed by two side walls 6c and 6d which also serve as the bending displacement members 1A and 1B, respectively.

  In this way, in the present drive device, the bending displacement members 1A and 1B are part of the wall portion of the camera module housing 6, and the elastic member 2 and the friction member 3 are arranged in the corner portion having a spatial margin. The space in the camera module housing 6 can be effectively used for the arrangement of the drive mechanism, and the drive device can be downsized. In addition, unlike the conventional driving device, this driving device does not have a configuration in which the driving member 302 and the piezoelectric element 301 are arranged in parallel in the optical axis direction, so that a reduction in the height of the device can be realized.

  In this drive device, the bending displacement members 1A and 1B, the elastic member 2, and the friction member 3 are arranged so that the lens barrel 4 is driven in a direction perpendicular to the bending displacement direction of the bending displacement members 1A and 1B. Hereinafter, the positional relationship between the bending displacement members 1A and 1B, the elastic member 2, and the friction member 3 and the principle of driving operation of the lens barrel 4 in the present driving device will be described.

(Position relationship)
FIG. 2A is a side view showing the positional relationship between the bending displacement members 1A and 1B, the elastic member 2, and the friction member 3 in the present driving device. FIG. 2B is a plan view showing the configuration of the present driving device. In FIG. 2A, a point where the bending displacement member 1A and the elastic member 2 are connected is a connection point A (indicated by X in the figure), and a point where the bending displacement member 1B and the elastic member 2 are connected is shown. The connecting point B (shown by X in the figure) is shown. A line passing through the centers of the bending displacement members 1A and 1B and parallel to the length direction is defined as a virtual line (first straight line) L1. The imaginary line L1 passes through the friction member 3. Further, it can be said that the imaginary line L1 is a straight line that is in a plane including the connection point A and the connection point B and extends in a direction perpendicular to the drive direction of the driven body.

  As shown in FIG. 2A, both the bending displacement members 1A and 1B are arranged side by side on the virtual line L1. In other words, a line passing through the center of the bending displacement member 1A and parallel to the length direction overlaps with a line passing through the center of the bending displacement member 1B and parallel to the length direction by the same virtual line L1. It is such an arrangement.

  Further, the connection point A and the connection point B are arranged such that a virtual line AB connecting these two points intersects the virtual line L1. Further, as shown in the figure, the connection point A is arranged on the upper side with respect to the virtual line L1. On the other hand, the connection point B is arranged below the virtual line L1.

  Further, the friction member 3 is arranged on an imaginary line AB connecting the connection point A and the connection point B. That is, when the contact portion of the friction member 3 with the lens barrel 4 passes through an arbitrary point of the virtual line AB and a straight line perpendicular to the plane including the connection points A and B is defined as the second straight line L1 ′. The second straight line L1 ′ is arranged so as to pass through.

  Also, as shown in FIG. 2B, the bending displacement member 1A is displaced in the direction of the arrow referred to as the bending displacement direction A, so that the connecting point A of the elastic member 2 is referred to as the elastic member displacement direction A. A displacement vector is excited in the direction of the arrow indicated. Further, since the bending displacement member 1B is displaced in the direction of the arrow referred to as the bending displacement direction B, a displacement vector is excited at the connection point B of the elastic member 2 in the direction of the arrow referred to as the elastic member displacement direction B ( That is, a displacement vector is excited in a direction perpendicular to the paper surface at the connection points A and B in FIG. In addition, although the displacement vector is excited in directions other than the above at the connection points A and B, since the relationship with the drive is small, the description is omitted.

  Hereinafter, the driving voltage waveform by the control means including the driving circuits 7A and 7B and the principle of the optical axis direction driving operation of the lens barrel 4 based on the driving voltage waveform in this driving device will be described.

(Operation principle 1)
First, an operation example in which the tip of the friction member 3 (the portion frictionally engaged with the lens barrel 4: a contact portion) is elliptically driven to drive the lens barrel 4 in the optical axis direction will be described. FIG. 13 is a graph showing an example of drive voltage waveforms applied to the two bending displacement members 1A and 1B. FIGS. 14A to 14C are explanatory diagrams for explaining the elliptical driving of the tip portion of the friction member 3 based on the driving voltage waveform shown in FIG. FIG. 14 is a diagram viewed from the direction of the arrow V in FIG.

  In FIG. 13, the drive voltage waveform applied to the bending displacement member 1A is waveform A, and the driving voltage waveform applied to the bending displacement member 1B is waveform B. The drive voltage waveforms of waveforms A and B are output from drive circuits 7A and 7B, respectively. As shown in the figure, waveform A and waveform B are sinusoidal drive voltage waveforms, and are signal waveforms that are relatively 90 degrees out of phase. Here, the states of the connection points A and B corresponding to the time points (i) to (ix) of the waveforms A and B shown in FIG. 13 are shown in FIGS.

  As shown in FIGS. 14A to 14C, when the waveforms A and B are driven, the positions of the connection points A and B change from (i) to (ix). That is, the connection points A and B are in the state (i) of FIG. 14 (a) at the time point (i) in FIG. 13, and (ii) in FIG. 14 (a) at the time point (ii) in FIG. In the state of (iii) in FIG. 13, the state of (iii) in FIG. 14 (a) is reached, and in the state of (iv) in FIG. 13, (iv) in FIGS. 14 (a) and (b). 14 (b) in FIG. 13 (v), and in FIG. 13 (vi), (vi) in FIGS. 14 (b) and 14 (c). In the state of (vii) in FIG. 13, the state becomes (vii) in FIG. 14 (c), and in the state of (viii) in FIG. 13, the state becomes (viii) in FIG. 14 (c). At the time of (ix) in FIG. 13, the state is in (ix) in FIG. 14 (c). As the connecting points A and B shift to the states (i) to (ix) shown in FIGS. 14A to 14C and are displaced, the tip of the friction member 3 becomes elliptic as shown in the figure. Will be driven. Here, if the displacement direction of the tip of the friction member 3 when in contact with the lens barrel 4 is referred to as a driving direction, the lens barrel 4 is driven to be scratched by the friction member 3 and is determined by the rotation direction of the tip. Driven in the driving direction.

  In the examples of FIGS. 13 and 14A to 14C, the tip of the friction member 3 is disposed so as to come into contact with or away from the lens barrel 4 due to its rotational displacement (elliptical drive). However, it is not limited to the above example.

  The drive device may be configured such that the tip of the friction member 3 is always in contact with the lens barrel 4. For example, a configuration in which a spring is applied as the elastic member 2 and the friction member 3 is pressed against the lens barrel 4 by the spring may be employed. Alternatively, the bending displacement members 1 </ b> A and 1 </ b> B may be configured to be pulled and fixed by a predetermined amount in the direction of the lens barrel 4 (direction of the driven body). Alternatively, the guide shaft 5 may be configured to be fixed so as to press the lens barrel 4 in the direction toward the friction member 3. With such a configuration, a preload is applied, and the tip of the friction member 3 is arranged so as to always contact the lens barrel 4.

  In such a configuration, the tip of the friction member 3 does not rotate elliptically (although distortion occurs in the bending displacement members 1A and 1B, the elastic member 2, the friction member 3, etc.), the direction opposite to the drive direction (reverse) A linear displacement in the driving direction) is excited alternately. Therefore, the friction member 3 has a difference in the pressing force against the lens barrel 4 between the displacement in the driving direction and the displacement in the reverse driving direction. That is, the force pressing the tip of the friction member 3 against the lens barrel 4 during displacement in the driving direction increases, and the force pressing against the lens barrel 4 decreases during displacement in the reverse driving direction.

  As a result, a difference in static friction force is generated between the friction member 3 and the lens barrel 4. Therefore, the tip of the friction member 3 does not slide on the lens barrel 4 when the lens barrel 4 is displaced in the driving direction, and the tip of the friction member 3 slides on the lens barrel 4 when the lens barrel 4 is displaced in the reverse driving direction. As described above, the friction coefficient and the preload of the friction member 3 can be adjusted. The lens barrel 4 is driven in the driving direction on average even if the lens barrel 4 is pulled back somewhat when displaced in the reverse driving direction.

  It is also possible to adjust the friction coefficient and pre-pressure of the friction member 3 so that the tip of the friction member 3 slides on the lens barrel 4 when the lens barrel 4 is displaced in the driving direction and the reverse driving direction. In this case, the driving force acting on the lens barrel 4 is determined by the dynamic friction force both when displaced in the driving direction and when displaced in the reverse driving direction. Even in such a case, a difference occurs in the pressing force of the friction member 3 against the lens barrel 4, so that the dynamic friction force in the driving direction becomes larger than the dynamic friction force in the reverse driving direction. Therefore, the lens barrel 4 is driven in the driving direction on average even if there is a period during which the lens barrel 4 is pulled back somewhat in the reverse driving direction.

  In the above example, the drive voltage waveform has been described as a sine wave waveform and a phase shift amount of 90 degrees. However, the drive voltage waveform is not particularly specified as a sine wave, and the phase shift amount is also 90 degrees. It is not limited.

(Operating principle 2)
Next, an operation example in which the tip of the friction member 3 (portion that frictionally engages the lens barrel 4) is driven in an arc and the lens barrel 4 is driven in the optical axis direction will be described. FIG. 15 is a graph showing drive voltage waveforms applied to the two bending displacement members 1A and 1B. FIGS. 16A and 16B are explanatory diagrams for explaining the arc driving of the tip of the friction member 3 based on the driving voltage waveform shown in FIG. FIG. 16 is a diagram viewed from the direction of the arrow V in FIG.

  In FIG. 15, the drive voltage waveform applied to the bending displacement member 1A is waveform A, and the driving voltage waveform applied to the bending displacement member 1B is waveform B. The drive voltage waveforms of waveforms A and B are output from drive circuits 7A and 7B, respectively. As shown in the figure, the waveform A and the waveform B are sawtooth drive voltage waveforms, and are signal waveforms that are relatively 180 degrees out of phase. Here, the states of the connection points A and B corresponding to the time points (i) to (v) of the waveforms A and B shown in FIG. 15 are shown in FIGS.

  As shown in FIGS. 16A and 16B, when the waveforms A and B are driven, the positions of the connection points A and B change from (i) to (v). That is, the connection points A and B are in the state (i) of FIG. 16 (a) at the time point (i) in FIG. 15, and (ii) in FIG. 16 (a) at the time point (ii) in FIG. 15 (iii) at the time of FIG. 15 (iii) in FIG. 16 (a) and (b), and (iv) of FIG. 16 (b) at the time (iv) of FIG. In this state, the state shown in (v) of FIG. 16 (b) is reached at the time of FIG. 15 (v). When the connecting points A and B are shifted to the states (i) to (v) shown in FIGS. 16 (a) and 16 (b), the tip of the friction member 3 becomes a circular arc as shown in the figure. Will be driven.

  At this time, since the tip of the friction member 3 is circularly driven by the saw-like drive voltage waveform shown in FIG. 15, there is a difference between the angular velocity in the driving direction and the angular velocity in the reverse driving direction (that is, (i) to While the angular velocity transitioning to the state (iii) is relatively slow, the angular velocity transitioning to the states (iii) to (v) is relatively high.

  In addition, by appropriately setting the driving voltage waveform, the tip of the friction member 3 can be made to have a difference between the angular acceleration in the driving direction and the angular acceleration in the reverse driving direction. That is, the angular acceleration that transitions to the states (i) to (iii) (driving direction) is relatively slow, while the angular acceleration that transitions to the states (iii) to (v) (reverse driving direction) is relatively The drive voltage waveform can be set so as to be faster. Therefore, by adjusting the friction coefficient of the friction member 3 and the like, the force applied to the contact between the friction member 3 and the lens barrel 4 exceeds the static friction force between the friction member 3 and the lens barrel 4 in the driving direction. It is possible to prevent the tip of the friction member 3 from sliding on the lens barrel 4. On the other hand, in the reverse drive direction, the force applied to the contact between the friction member 3 and the lens barrel 4 exceeds the static friction force between the friction member 3 and the lens barrel 4, so that the tip of the friction member 3 slides on the lens barrel 4. Can be. As a result, a difference occurs between the driving force in the driving direction and the driving force in the reverse driving direction, and the lens barrel 4 is driven in the driving direction.

  Further, it is possible to adjust the friction coefficient and the like so that the tip of the friction member 3 slides on the lens barrel 4 in both the driving direction and the reverse driving direction. In this case, the driving force in the driving direction and the driving force in the reverse driving direction are determined by the dynamic friction force and become the same force. However, the drive voltage waveform shown in FIG. 15 sets the displacement time in the drive direction to be long and the displacement time in the reverse drive direction to be short. Therefore, the time during which the dynamic friction force in the drive direction is applied is reverse driven. It becomes longer than the time when the dynamic frictional force of the direction is acting. Therefore, as a result, the lens barrel 4 is driven in the driving direction.

  The drive device may be configured such that the tip of the friction member 3 is always in contact with the lens barrel 4. For example, a configuration in which a spring is applied as the elastic member 2 and the friction member 3 is pressed against the lens barrel 4 by the spring may be employed. Alternatively, the bending displacement members 1 </ b> A and 1 </ b> B may be configured to be pulled and fixed by a predetermined amount in the direction of the lens barrel 4 (direction of the driven body). Alternatively, the guide shaft 5 may be configured to be fixed so as to press the lens barrel 4 in the direction toward the friction member 3. With such a configuration, a preload is applied, and the tip of the friction member 3 is arranged so as to always contact the lens barrel 4.

  In such a configuration, the tip of the friction member 3 is rotated in a direction opposite to the driving direction (reverse driving), instead of rotating in a circular arc (distortion occurs in the bending displacement members 1A and 1B, the elastic member 2, the friction member 3, etc.). (Direction) linear displacements are alternately excited. Even in such a case, it goes without saying that the lens barrel 4 can be driven by the same principle described in the operation principle 1.

  In addition, the elastic member is connected so that the virtual line connecting the center of the connection point A and the center of the connection point B intersects the virtual line parallel to the length direction as described above (ideally orthogonally). Therefore, the tip of the friction member can be rotationally driven or driven in a circular arc (straight line) in the optical axis direction by the displacement of the bending displacement members 1A and 1B. Then, the connecting portion of the two bending displacement members 1A and 1B is bent at a corner (ideally 90 degrees), and the lens barrel is placed in a virtual sector space region formed by the two bending displacement members. 4 is disposed, and the bending displacement members 1A and 1B are disposed on the wall surface of the housing 6, whereby the drive device can be reduced in size and height. At this time, it is not necessary to completely follow the wall surface of the housing 6, and it goes without saying that it may be appropriately arranged according to the empty space in the module housing 6.

[Second Embodiment]
Another embodiment of the present invention will be described below with reference to FIGS. 3 (a) and 3 (b). FIG. 3A is a side view showing a positional relationship among the bending displacement member, the elastic member, and the friction member in the present driving device. FIG. 3B is a plan view showing the configuration of the present driving device. In FIG. 3A, the point where the bending displacement member 21A and the elastic member 2 are connected is defined as a connection point A (indicated by X in the figure), and the point where the bending displacement member 21B and the elastic member 2 are connected. The connecting point B (shown by X in the figure) is shown. A line passing through the centers of the bending displacement members 21A and 21B and parallel to the length direction is defined as an imaginary line L1. The imaginary line L1 passes through the friction member 3.

  Note that the driving principle of the present driving device is the same as the driving principle described in the first embodiment, and a description thereof will be omitted.

  As shown in FIG. 3A, the connection points A and B are arranged in the same manner as in the first embodiment. That is, the connection point A and the connection point B are arranged such that a virtual line AB connecting these two points intersects the virtual line L1. Further, as shown in the figure, the connection point A is arranged on the upper side with respect to the virtual line L1. On the other hand, the connection point B is arranged below the virtual line L1.

  The present driving device is different from the first embodiment in that the elastic member 2 and the friction member 3 are not arranged at the corner portion of the camera module housing 26. The bending displacement members 21 </ b> A and 21 </ b> B are arranged using only one of the side wall surfaces of the camera module housing 26. That is, the bending displacement members 21 </ b> A and 21 </ b> B are configured to serve as only one side wall 26 d among the side walls 26 a to 26 d of the camera module housing 26. And the elastic member 2, the friction member 3, and the guide shaft 5 are distribute | arranged to the center part of the side wall 26d.

  With such a configuration, the space in the camera module housing 26 can be effectively used for the arrangement of the drive mechanism, and the drive device can be downsized.

  In this drive device, the size of the bending displacement members 21A and 21B is less than half of the side wall 26d. Therefore, the driving force of the lens barrel 4 is smaller in the present driving device than in the driving device of the first embodiment. However, by reducing the weight of the lens (optical member) and the lens barrel 4, the lens barrel 4 can be sufficiently driven. In addition, the present driving device is advantageous in that the driving device can be reduced in height as compared with the driving device of the first embodiment.

[Third Embodiment]
Still another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a side view showing a positional relationship among the bending displacement member, the elastic member, and the friction member in the present driving device. In FIG. 4, a point where the bending displacement member 31A and the elastic member 2 are connected is a connection point A (indicated by X in the drawing), and a point where the bending displacement member 31B and the elastic member 2 are connected is a connection point B. (Indicated by X in the figure). A line passing through the friction member 3 and parallel to the length direction is defined as an imaginary line L2.

  As shown in FIG. 4, the connection points A and B are arranged so that a virtual line AB connecting these two points intersects the virtual line L2. Further, as shown in the figure, the connection point A is arranged on the upper side with respect to the virtual line L2. On the other hand, the connection point B is arranged below the virtual line L2.

  Further, the bending displacement members 31A and 31B are arranged so as to be shifted from the virtual line L2 (offset arrangement). That is, when the line passing through the center of the bending displacement member 31A and parallel to the length direction is an imaginary line L1A, and the line passing through the center of the bending displacement member 31B and parallel to the length direction is the imaginary line L1B, the imaginary line L1A The virtual line L1B and the virtual line L2 are arranged so as not to overlap each other.

  Even with such a configuration, the space in the camera module housing can be used effectively for the arrangement of the drive mechanism, and the drive device can be downsized.

  This drive device may be configured such that the bending displacement members 31A and 31B are arranged using only one of the side wall surfaces of the camera module housing. Moreover, it may be arranged on the two side walls of the camera module housing, and the elastic member 2 and the friction member 3 may be arranged on the corner portion.

[Fourth Embodiment]
Still another embodiment of the present invention is described below with reference to FIG. FIG. 5 is a side view showing a positional relationship among the bending displacement member, the elastic member, and the friction member in the present driving device. In FIG. 5, a line passing through the friction member 3 and parallel to the length direction is defined as an imaginary line L2.

  As shown in FIG. 5, the present driving device has a four-plate configuration including four bending displacement members 41 </ b> A to 41 </ b> D. These bending displacement members 41 </ b> A to 41 </ b> D are arranged so as to be symmetric (point symmetry or line symmetry) with respect to the friction member 3. The bending displacement members 41A and 41C are disposed above the virtual line L2, while the bending displacement members 41B and 41D are disposed below the virtual line L2.

  Here, a point where the bending displacement member 41A and the elastic member 2 are connected is a connection point A (indicated by X in the drawing), and a point where the bending displacement member 41B and the elastic member 2 are connected is a connection point B ( A point where the bending displacement member 41C and the elastic member 2 are connected is a connection point C (shown by an X in the drawing), and the bending displacement member 41D and the elastic member 2 are connected to each other. A connecting point is a connecting point D (indicated by X in the figure). As shown in FIG. 5, the connection point A and the connection point B are arranged such that a virtual line AB connecting these two points intersects the virtual line L2. Similarly, the connection point C and the connection point D are arranged so that a virtual line CD connecting these two points intersects the virtual line L2.

  In other words, the connection points A to D are arranged such that, when a perpendicular line perpendicular to the virtual line L2 is drawn, two connection points arranged with the virtual line L2 in between are on the vertical line. In FIG. 5, the connection points A and D are arranged across the virtual line L2, and the two connection points A and D are on a perpendicular line perpendicular to the virtual line L2. Further, the connection points B and C are arranged across the virtual line L2, and the two connection points B and C are on a perpendicular line to the virtual line L2.

  Note that the connection points A and D and the connection points B and C are not limited to being arranged on a straight line perpendicular to the virtual line L2, but may be arranged on a straight line intersecting the virtual line L2. That is, the figure formed by connecting the connection points A to D may be a trapezoid or a rhombus.

  In this driving apparatus, the bending displacement members 41A and 41C are connected to the driving circuit 7A and are driven in phase by the driving circuit 7A. The bending displacement members 41B and 41D are connected to the drive circuit 7B and are driven in phase by the drive circuit 7B.

  Even with such a configuration, the space in the camera module housing can be used effectively for the arrangement of the drive mechanism, and the drive device can be downsized.

  This drive device may have a configuration in which the bending displacement members 41A to 41D are arranged using only one of the side wall surfaces of the camera module housing. Moreover, it may be arranged on the two side walls of the camera module housing, and the elastic member 2 and the friction member 3 may be arranged on the corner portion.

  Compared with the first embodiment, this drive device has an increased number of bending displacement members and a complicated structure. However, the present driving device has an advantageous effect that the displacement in the unnecessary direction can be suppressed when the bending displacement of the bending displacement member is converted into the displacement in the driving direction of the lens barrel. The present driving device shown in FIG. 5 has a four-plate configuration including four bending displacement members. However, the present driving device is not limited to this four-element configuration, and when a perpendicular perpendicular to the imaginary line L2 is drawn, two connecting points arranged with the imaginary line L2 in between are on the perpendicular. Any configuration that has a certain arrangement may be used. For example, in FIG. 5, the bending displacement members 41 </ b> B and 41 </ b> C may be omitted, and the bending displacement members 41 </ b> A and 41 </ b> D may be connected to only one side of the elastic member 2.

  In the two-sheet configuration, the imaginary line connecting the connection points of the bending displacement members 41A and 41D is orthogonal to the imaginary line L2. However, the configuration is not limited to this, and it is only necessary to intersect the imaginary line L2. .

[Fifth Embodiment]
Still another embodiment of the present invention will be described below with reference to FIGS. 6 (a) and 6 (b). FIG. 6A is a side view showing the positional relationship among the bending displacement member, the elastic member, and the friction member in the present driving device. FIG. 6B is a plan view showing the configuration of the drive device. In FIG. 6A, a line that passes through the center of the bending displacement member 51A and is parallel to the length direction is defined as an imaginary line L1. The imaginary line L1 passes through the friction member 3.

  As shown in FIG. 6A, the driving device has a single-sheet configuration including one bending displacement member 51A. The bending displacement member 51 </ b> A is provided as a part of only one side wall 56 c of the camera module housing 56. The elastic member 52 and the friction member 3 are disposed at a corner portion formed by the side wall 56c (bending displacement member 51A) and the side wall 56d. That is, the side wall 56d is connected to the elastic member 52 and the friction member 3 on the opposite side to the bending displacement member 51A.

  Here, a point where the bending displacement member 51A and the elastic member 52 are connected is a connection point A (indicated by X in the figure), and a point where the side wall 56c and the elastic member 52 are connected is a connection point B (in the figure). X). As shown in FIG. 6A, the connection point A and the connection point B are arranged such that a virtual line AB connecting these two points intersects the virtual line L1.

  With such a configuration, the space in the camera module housing 56 can be effectively used for the arrangement of the drive mechanism, and the drive device can be downsized.

  Hereinafter, the principle of driving operation of the lens barrel 4 in the optical axis direction in the present driving device will be described. FIGS. 17A and 17B are explanatory diagrams for explaining the arc driving of the tip of the friction member 3 in the present driving device.

  As shown in FIGS. 17A and 17B, when a voltage is applied to the bending displacement member 51A, only the connection point A is displaced. That is, the state (i) shown in FIGS. 17A and 17B is displaced to the state (v). Therefore, the tip of the friction member 3 (the portion that frictionally engages the lens barrel 4) is displaced in an arc shape centered around the connection point B.

  In the present drive device, the drive waveform of the voltage applied to the bending displacement member 51A may be a driving waveform that enables the connection point A to reciprocate in the bending displacement direction A by the application. That is, in the present driving device, it is only necessary to apply a voltage having a driving waveform such that a positive voltage and a negative voltage are alternately applied to the bending displacement member 51A. For example, in the driving device shown in FIGS. 6A and 6B, the voltage of the waveform A shown in FIG. 15 is applied to the bending displacement member 51A.

  Thus, in this drive device, the arc drive of the tip of the friction member 3 is possible, similar to the above (drive principle 2). In the present driving device, since the driving source of the lens barrel 4 is only the bending displacement member 51A, the driving force of the lens barrel 4 is smaller in the driving device than in the driving device of the first embodiment. However, by reducing the weight of the lens (optical member) and the lens barrel 4, the lens barrel 4 can be sufficiently driven. Further, the present driving device is advantageous in that the number of parts is reduced and the cost and size can be reduced as compared with the driving device of the first embodiment.

[Sixth Embodiment]
Still another embodiment of the present invention will be described below with reference to FIGS. 7 (a) and 7 (b). FIG. 7A is a side view showing the positional relationship between the bending displacement member, the elastic member, and the friction member in the present driving device. FIG. 7B is a plan view showing the configuration of the present driving device.

  In the driving devices of the first to fifth embodiments, the bending displacement member is a bimorph structure piezoelectric element having a three-layer structure in which two piezoelectric material layers are bonded with a shim material interposed therebetween. On the other hand, in this drive device, the bending displacement member is a piezoelectric element having a two-layer structure in which two piezoelectric material layers are bonded to each other. That is, the bending displacement member in the present driving device is a so-called shimless bimorph structure piezoelectric element constituted by two piezoelectric material layers excluding the shim material.

  As shown in FIGS. 7A and 7B, in the present driving device, the bending displacement members 81A and 81B are connected to the elastic member (driving direction changing member) 82. The elastic member 82 is provided on the surface of the bending displacement members 81A and 81B facing the lens barrel 4. The elastic member 82 is connected to the friction member 3 that frictionally engages the lens barrel 4.

  Here, the bending displacement members 81A and 81B are piezoelectric elements having a shimless bimorph structure in which the shim material is removed and the piezoelectric material layer is composed of two layers. Each of the bending displacement members 81A and 81B is formed as a part of the side wall of the camera module housing 86, and is fixed to the camera module housing 86 by adhesion or fitting.

  In the driving devices of the first to fifth embodiments, the bending displacement member is a bimorph piezoelectric element, and the shim material in the bending displacement member is fixed to the camera module housing. Since this shim material has a function as an electrode, it is made of a conductive material. On the other hand, the piezoelectric material layer is made of a non-conductive material. This drive device has a configuration in which the piezoelectric material layer in the bending displacement members 81A and 81B is fixed to the camera module housing 86, and a shim material made of a conductive material is removed. For this reason, the bending displacement members 81A and 81B are fixed to the camera module housing 86 in a state of being insulated from the lens barrel 4 as compared with the bending displacement members in the driving devices of the first to fifth embodiments.

  Next, the effect of the present driving device in which the bending displacement members 81A and 81B are piezoelectric elements having a shimless bimorph structure will be described with specific examples. In the embodiment, the dimensions of the piezoelectric material layer in the bending displacement member are a free length of 3 mm in the length direction, a width of 2 mm, and a thickness of 0.125 mm, and the mirror is applied with an applied voltage (driving voltage) of 14 V applied to the bending displacement member. The cylinder is driven.

  First, when a lens barrel is driven using a bimorph structure piezoelectric element composed of a piezoelectric material layer having the above dimensions and a shim material having a thickness of 0.2 mm as a bending displacement member (hereinafter referred to as Example) 1), the amount of displacement of the tip of the elastic member 3 was 0.368 μm. On the other hand, when a lens barrel is driven using a piezoelectric element having a shimless bimorph structure composed only of a piezoelectric material layer having the above dimensions as a bending displacement member (hereinafter referred to as Example 2), an elastic member The amount of displacement at the tip of No. 3 was 0.4 μm.

  As described above, the driving device according to the second embodiment, that is, the driving device including the piezoelectric element having the shimless bimorph structure as the bending displacement member has a displacement amount at the tip of the elastic member 3 as compared with the driving device according to the first embodiment. It can be seen that it has increased by 8.7%.

  Next, the effect of the present driving device will be described with reference to a driving device (referred to as a third embodiment) in which the portion corresponding to the shim material in the bending displacement member of the driving device of the first embodiment is replaced with a piezoelectric material layer. In the driving device of the third embodiment, the total thickness of the bending displacement member is the same as that of the driving device of the first embodiment.

  In the driving device of Example 3, when the stress applied to the piezoelectric material layer was the same as that of the driving device of Example 1, the amount of displacement of the tip of the elastic member 3 was 0.451 μm. That is, even under the condition that the total thickness of the bending displacement member is the same, the driving device (Example 3) including the piezoelectric element having the shimless bimorph structure as the bending displacement member has the bimorph structure as the bending displacement member. It can be seen that the displacement amount of the tip of the elastic member 3 is increased by 22.6% as compared with the driving device (Example 1) provided with the piezoelectric element.

  From the above, in the present driving device in which the bending displacement member is composed only of the piezoelectric material layer, the displacement amount of the tip of the elastic member 3 is increased as compared with the driving device in which the bending displacement member includes the shim material and the piezoelectric material layer. You can see that

  Further, in this drive device, the proportion of the piezoelectric material layer in the bending displacement member is higher than that in the configuration in which the bending displacement member includes the shim material and the piezoelectric material layer. Therefore, in the present driving device, the thickness of the piezoelectric material layer as the bending displacement member becomes thicker. When the polarization direction is set in the stacking direction of the two piezoelectric material layers, the fragility of polarization when a voltage is applied contributes to the stacking direction thickness of the two piezoelectric material layers. Therefore, the thinner the two piezoelectric material layers are in the stacking direction, the more easily the polarization is broken. In the present driving device, the thickness in the stacking direction of the two piezoelectric material layers can be increased, so that depolarization (breakage of polarization) of the piezoelectric material layer can be prevented.

  Further, in the present driving device, when the device is manufactured, a step of bonding the shim material and the piezoelectric material layer is not required. Therefore, the manufacturing process can be omitted, and cost reduction can be realized.

  In the configuration shown in FIGS. 7A and 7B, the bending displacement members 81A and 81B are composed of two piezoelectric material layers, but the piezoelectric material layer as the bending displacement member of the present driving device is However, the present invention is not limited to this configuration. The bending displacement members 81 </ b> A and 81 </ b> B are bent and displaced as the two piezoelectric material layers expand and contract alternately (when one piezoelectric material layer expands, the other piezoelectric material layer contracts). Therefore, each of the two piezoelectric material layers may be composed of a plurality of layers.

(About the driving direction changing member and the bending displacement member in the present driving device)
In the driving devices of the first to sixth embodiments, the driving direction conversion member has a configuration in which the elastic member and the friction member are separate members, but the driving direction conversion member in the present invention has this configuration. It is not limited. FIGS. 8A to 8C are perspective views showing an example of the configuration of a driving direction changing member applicable to the present invention.

  As shown in FIGS. 8A and 8B, the drive direction conversion member may have a configuration in which an elastic member and a friction member are integrally formed. As shown in FIG. 8A, the drive direction conversion member has a configuration in which an elastic portion (elastic member) 62a and a friction portion (friction member) 63a are integrally formed. In the drive direction conversion member shown in FIG. 8A, the elastic portion 62a and the friction portion 63a are formed by bending a plate material such as metal constituting the drive direction conversion member.

  Further, as shown in FIG. 8B, the drive direction changing member may be a solid body in which the elastic portion 62b and the friction portion 63b are integrated. In this case, the drive direction changing member can be formed by integral molding using a mold or by cutting.

  Moreover, the material which comprises the drive direction conversion member shown by FIG.8 (b) will not be specifically limited if it is a material which can be integrally molded or cut, for example, resin, ceramic, metal, or carbon etc. Can be mentioned. Further, the material constituting the driving direction changing member shown in FIG. 8B is preferably selected from materials having a small change in friction coefficient due to a temperature change, a humidity change, a change with time, or a material wear. . As a material constituting the driving direction changing member shown in FIG. 8B, for example, a material obtained by irradiating a polymer material with an electron beam, graphite, and a glassy material that is lightweight, heat conductive, and excellent in wear resistance. Examples thereof include a carbon material combined with carbon.

  Further, the drive device of the present invention may have a configuration in which the material constituting the drive direction conversion member is attached to the contact portion of the lens barrel 4 with the friction portion 63b.

  Moreover, the structure shown by FIG.8 (c) may be sufficient as a drive direction conversion member. That is, as shown in the figure, the drive direction changing member includes an elastic member 62c and a friction member 63c, and these are connected. The elastic member 62c is formed with a protruding portion 600c protruding toward the lens barrel side. And the friction member 63c is affixed on the front-end | tip part by the side of the lens-barrel in the protrusion part 600c. The elastic member 62c provided with the protruding portion 600c can be formed by integral molding using a mold or cutting. The driving direction changing member shown in FIG. 8C can be formed by attaching the friction member 63c to the formed protrusion 600c.

  Moreover, a carbon material is mentioned as a material which comprises the friction member 63c. In the configuration shown in FIG. 8C, the degree of freedom in material selection is relatively low. However, it is advantageous in that a material with a small change in friction coefficient due to changes in temperature and humidity can be easily selected.

  In the driving devices of the first to fifth embodiments, the friction member as the contact portion that contacts the driven body is arranged on the imaginary line connecting the driving direction changing member to the first and second connecting portions. It was the configuration that was made. However, the configuration of the driving direction changing member in the driving device of the present invention is not limited to the above configuration.

  For example, as shown in FIGS. 8E and 8E, a configuration in which friction members 63d and 63e serving as contact portions are arranged so as to be shifted from a virtual line AB connecting the connection points A and B may be employed. As shown in FIG. 8E, the friction member 63d does not have to be arranged on the line that divides the elastic member 62d into two in the driving direction (optical axis direction), and the elastic member 62d is defined as the driving direction. It does not need to be arranged on the line I divided into two in the vertical direction.

  Further, as shown in FIG. 8 (e), the friction member 63e may be disposed outside the connection points A and B. In FIG. 8E, in the elastic member 62 as a surface including the connection points A and B, a straight line that passes through the connection point A and extends in a direction perpendicular to the driving direction is a U line, and passes through the connection point B. A straight line extending in a direction perpendicular to the driving direction is defined as a d-line. As shown in the figure, the friction member 63e is disposed outside the region sandwiched between the U and D lines.

  Even in the configuration shown in FIGS. 8D and 8E, the tips of the friction members 63d and 63e can be elliptically or circularly moved.

  Further, as shown in FIGS. 8F and 8G, the shape of the friction member as the contact portion may be a semi-cylindrical shape. As shown in FIG. 8 (f), the drive direction conversion member has a configuration in which the elastic portion 62f and the friction portion 6f are integrated, and the portion of the friction portion 63f that contacts the lens barrel is a semi-cylindrical shape. It has become. Further, as shown in FIG. 8G, the drive direction changing member includes an elastic member 62g and a friction member 63g, and these are connected. The elastic member 62g is formed with a protruding portion 600c protruding toward the lens barrel side. And the friction member 63g is affixed on the front-end | tip part by the side of the lens-barrel in the protrusion part 600c. A portion of the friction member 63g that contacts the lens barrel has a semi-cylindrical shape. With the configuration shown in FIGS. 8F and 8G, even when the contact portion of the drive direction conversion member is tilted and comes into contact with the lens barrel, the friction characteristic is hardly changed.

  Moreover, the shape of the contact part in a drive direction conversion member is not limited to semicircular column shape. Even if the shape of the contact portion is, for example, a hemispherical shape or a conical shape, even when the contact portion of the drive direction conversion member is tilted and comes into contact with the lens barrel, the friction characteristic is hardly changed. Thus, no matter what the shape of the contact portion is, it does not depart from the scope of the present invention.

  18A to 18C are explanatory views showing an example of the locus of the tip of the friction member 63e in the arrangement of the friction member 63e shown in FIG. 8E. As shown in FIGS. 18A to 18C, the connecting points A and B are displaced to the states (i) to (ix), respectively, so that the tip of the friction member 63e is elliptically moved.

  19 (a) and 19 (b) are explanatory views showing another example of the locus of the tip of the friction member 63e in the arrangement of the friction member 63e shown in FIG. 8 (e). As shown in FIGS. 19A and 19B, the connecting points A and B are displaced to the states (i) to (ix), respectively, so that the tip of the friction member 63e is elliptically moved.

  That is, regardless of the positional relationship between the connection points A and B and the friction member as the contact portion, the displacement of the connection points A and B (the drive voltage waveform applied to the bending displacement members 1A and 1B) can be made to correspond. For example, the locus of the tip of the friction member can be controlled to be elliptical or arcuate.

  Preferably, the friction member as the contact portion passes through an arbitrary point on an imaginary line connecting the first and second connecting portions and is perpendicular to a plane including the first and second connecting portions. When the straight line is the second straight line, the second straight line is arranged so as to pass through. Since the friction member as the contact portion is arranged on a virtual line connecting the first and second connecting portions, the displacement of the virtual line according to the displacement of the first and second connecting portions is more efficiently performed. The displacement of the contact portion with the driven body can be converted, and the displacement of the contact portion with the driven body can be realized by the relatively small bending displacement of the first and second bending displacement members. The best mode of arrangement of the friction member is a configuration in which the friction member as the contact portion is arranged at the center on the imaginary line connecting the first and second connecting portions.

  In the driving devices of the first to sixth embodiments, the elastic member and the bending member are separate members. However, the driving direction changing member in the present invention is not limited to this structure. FIG. 9 is a perspective view showing an example of a configuration of a bending member and an elastic member applicable to the present invention.

  The two bending displacement members shown in FIG. 9 are bimorph piezoelectric elements having a three-layer structure in which two piezoelectric material layers 71 are bonded with a shim material 72 interposed therebetween. These two bending displacement members are each provided with a common shim material 72. The common shim material 72 is configured by connecting two bending displacement members. An elastic part as an elastic member and a friction part as a friction member are integrally formed at the connecting portion of the two bending displacement members in the shim material 72. That is, the elastic member and the friction member are formed as a part of the shim material 72 in the bending displacement member.

  The two bending displacement members shown in FIG. 9 can be formed by pressing the two piezoelectric material layers 71 so as to sandwich only one shim material 72 and forming a pair of bending displacement members. Then, the elastic portion and the friction portion are integrally formed by bending the connecting portion of the two bending displacement members in the shim material 72.

  Further, regarding the fixation of the bending displacement member, the driving devices of the first to fifth embodiments have a configuration in which one end portion in the length direction of the bending displacement member is fixed. However, the fixation of the bending displacement member in the present invention is not limited to the configuration in which one end in the length direction is fixed. FIG. 10A is an explanatory diagram for explaining the concept of fixing the bending displacement member in the driving devices of the first to fifth embodiments, and FIG. 10B is applicable to the driving device of the present invention. It is explanatory drawing for demonstrating an example of fixation of a flexible bending displacement member. In FIGS. 10A and 10B, as the concept of fixing the bending displacement member, the fixed portion is shown as a hatched portion.

  As shown in FIG. 10A, in the driving devices of the first to fifth embodiments, the bending displacement members 1A and 1B have one end in the length direction (the elastic member 2 and the friction member 3 are included in the length direction). This is a configuration in which the end opposite to the connecting side) is fixed. The bending displacement members 1A and 1B shown in FIG. 10A are bent in the bending displacement directions A and B indicated by arrows with the shaded portion as a fulcrum. As a result, the bending displacement members 1A and 1B are displaced to positions surrounded by dotted lines.

  As an example of fixing of the bending displacement member, for example, as shown in FIG. 10B, the bending displacement members 1A and 1B have a configuration in which one end in the width direction (optical axis direction) is fixed. May be. The bending displacement members 1A and 1B shown in FIG. 10A are bent in the bending displacement directions A and B indicated by arrows with the shaded portion as a fulcrum. As a result, the bending displacement members 1A and 1B are displaced to positions surrounded by dotted lines.

  The configuration shown in FIG. 10B is a configuration in which a hatched portion as a portion where the bending displacement members 1A and 1B are fixed is perpendicular to the hatched portion shown in FIG. . The bending displacement by fixing the bending displacement members 1A and 1B is simply by changing the vertical and horizontal dimensions of the bending displacement members 1A and 1B in FIG. It can be realized by rotating and mounting.

(About the imaging apparatus of the present invention)
The drive device of the present invention is expected to be applied to an image pickup device equipped with a focus adjustment mechanism and a zoom mechanism such as a camera module (the lens group must be driven), and particularly applied to a small camera module for a mobile phone or the like. It is useful to do.

  In general, a small camera module has a configuration in which members included in all mechanisms of an imaging apparatus (a lens barrel driving mechanism and an imaging mechanism) are accommodated in a prismatic or cylindrical camera module housing. As described above, the drive device of the present invention can effectively use the space in the camera module housing for the arrangement of the drive mechanism, and the drive device can be downsized. Therefore, by setting the dimensions of the driving device so that it does not exceed the dimensions determined by the members other than the driving device in the imaging device, the maximum effect can be achieved in reducing the height and size of the imaging device. Is possible.

  Hereinafter, the dimensions of the imaging device and the driving device of the present invention will be described with reference to FIG. FIG. 11 is a cross-sectional view illustrating a configuration of an imaging apparatus in which the driving device illustrated in FIGS. 1A and 1B is accommodated in a camera module housing. FIG. 11 is a cross-sectional view taken along a diagonal line sandwiched between the side walls 6c and 6d (bending displacement members 1A and 1B) of the rectangular parallelepiped camera module housing 6 in FIG. Therefore, the bending displacement members 1A and 1B are not shown in FIG. Further, the guide shaft 5 is omitted because the drawing becomes complicated.

  As shown in FIG. 11, the imaging apparatus of the present invention (hereinafter referred to as the present imaging apparatus) includes the present driving apparatus, and further includes an objective lens 3011, an imaging element 3012, and a circuit board 3013. The objective lens 3011, the imaging element 3012, and the circuit board 3013 are members that are essential as an imaging apparatus.

  The imaging apparatus shown in FIG. 11 includes a so-called focus adjustment mechanism. Specifically, the objective lens 3011 is fixed to the lens barrel (driven body) 4 and is driven in the optical axis direction as the lens barrel 4 is driven by the driving device. By driving the objective lens 3011 in the optical axis direction, focus adjustment is performed, and an image of a desired subject is formed on the photoelectric conversion element of the image sensor 3012.

  Here, the dimension in the optical axis direction of members other than the driving device in the imaging apparatus will be considered. In FIG. 11, the thickness of the bottom of the camera module housing in the optical axis direction is dimension A, and the total of the thickness in the optical axis direction of the image sensor 3012 and the thickness of the circuit board 3013 in the optical axis direction is dimension B. . In addition, the focal length of the objective lens 3011 is f, and the total of the thickness in the optical axis direction of the upper part (lid part) of the camera module housing 6 and the clearance that can allow an assembly error is the dimension C. Note that here, when the objective lens 3011 is moved to a position where an object at infinity is focused on the photoelectric conversion element in the imaging element 3012, the focal length f is transparent from the tip of the objective lens 3011. It is defined as the distance to the cover surface.

  The dimension of the camera module housing in the optical axis direction is determined by the sum of dimension A, dimension B, focal length f, and dimension C.

  When a practical dimension that is easy to manufacture and takes strength into consideration is applied to the dimension A, the dimension B, the focal length f, and the dimension C, the dimension A = about 0.5 [mm], the dimension B = About 1.0 to 2.0 [mm] and dimension C = A = about 0.5 [mm]. The focal length f is selected and designed according to the use of the imaging apparatus. When the objective is to realize a camera module that is capable of wide-angle photography and is as thin as possible, the focal length f is about 2.0 [mm] (however, the diagonal size of the imaging surface is 4 [ mm] or smaller image sensor 3012).

  Therefore, the dimension (dimension A + dimension B + dimension C + focal length f) in the optical axis direction of the camera module housing 6 is 5 [mm] if the dimension B = 2.0 [mm].

  At this time, the dimension of the camera module housing 6 in the optical axis direction: (A + B + C + f) normalized by f is about (A + B + C + f) /f=2.5.

  Therefore, when the dimensions are set as described above, the dimensions in the optical axis direction of the bending displacement members 1A and 1B used as the drive source may be 2.5 times or less of the focal length f. At this time, the dimension of the imaging device in the optical axis direction is determined by the dimensions of the members other than the driving device, and is thus most effective in reducing the height of the imaging device.

  When the focal length f = 2.5 and the dimension B = 1.0 [mm] are set, the dimension in the optical axis direction of the bending displacement members 1A and 1B used as the drive source is 1.8 of the focal distance f. Doubled.

  Next, the dimensions in the direction (lateral direction) perpendicular to the optical axis direction of the members other than the driving device in the imaging apparatus will be considered. In FIG. 11, the sum of the thickness of the camera module housing side wall and the clearance that allows for assembly errors is taken as dimension X, the side wall thickness of the lens barrel 4 is taken as dimension Y, and the diameter of the objective lens 3011 is taken as the diameter R. Yes.

  The size of the camera module housing in the lateral direction is determined by the sum of the total of the dimension X and the dimension Y and the diameter R (2 × (X + Y) + R).

  When a practical dimension that is easy to manufacture and takes strength into consideration is applied to the dimension X, the dimension Y, and the diameter R, the dimension X = 0.8 [mm] and the dimension Y = 1.0 [ mm]. The diameter R is selected and designed according to the use of the imaging device. In order to obtain an appropriate brightness, the diameter R = 1.8 [mm] (effective diameter is about 0.8 [mm]).

  Therefore, the dimension (2 × (X + Y) + R) in the horizontal direction of the camera module housing 6 is 5.4 [mm].

  At this time, the dimension of the camera module housing 6 in the horizontal direction: 2 × (X + Y) + R normalized by R is about (2 × (X + Y) + R) / f = 3.

  Therefore, when the dimensions are set as described above, the dimension in the lateral direction of the bending displacement members 1A and 1B used as the drive source may be set to be three times or less the diameter R. At this time, the dimension in the horizontal direction of the imaging device is determined by the dimensions of the members other than the driving device, and is thus most effective for downsizing the imaging device.

  When the dimension Y = 0.3 to 0.8 [mm] is set, the diameter R is about 3.2 [mm], and when the dimension Y is set, the dimension in the lateral direction of the bending displacement members 1A and 1B is , About 1.6 times the diameter R.

  Although not particularly mentioned in the above description, the amplitude of the voltage output from the drive circuits 7A and 7B is the mass of the driven body, the load applied to the driven body, the required speed of the driven body, the material of the contact portion, etc. It is designed to be about 1 [V] to 100 [V] depending on parameters, and the drive frequency is similarly designed to be about 50 [Hz] to 500 [kHz]. Similarly, the displacement of the contact portion is designed in a wide range of about 10 [nm] to 1 [mm], but any design value does not depart from the scope of the present invention.

  Moreover, the imaging device of this invention is the whole apparatus provided with the above-mentioned imaging device. Examples of the imaging device of the present invention include imaging devices such as a mobile phone, a digital camera, and a video camera.

  In the above description, the elastic member and the friction member are described as separate members. However, even when these members are integrally formed, they do not depart from the scope of the present invention.

  Further, although the elastic member and the bending displacement member have been described as separate members, for example, the elastic member and the bending displacement member are formed as an extension of a shim material provided as an intermediate layer of the bending displacement member. Even when formed integrally, it does not depart from the scope of the present invention.

  The shape of the optical device casing is not limited to a rectangular parallelepiped shape. For example, the present invention can be applied to a cylindrical shape or an elliptical cylindrical shape.

  The drive device of the present invention can be expressed as follows.

  That is, the drive device of the present invention includes a first bending displacement member whose bending displacement is excited by electrical control, a second bending displacement member whose bending displacement is excited by electrical control, and the first bending displacement. An elastic member connected to a part of the member at the first connecting part and connected to a part of the second bending displacement member and the second connecting part, a part connected to the elastic member, and a part driven It can be expressed that the configuration includes a friction member in contact with the body.

  In the above configuration of the driving device of the present invention, a virtual line connecting the first connecting portion and the second connecting portion, and the length direction of the first bending displacement member or the length of the second bending displacement member. It can be expressed as a configuration in which a virtual line parallel to the direction intersects.

  Furthermore, in the above-described configuration of the driving apparatus of the present invention, the first bending displacement member is further passed through the center of the first bending displacement member and is parallel to the first region by an imaginary line parallel to the length direction of the first bending displacement member. The second bending displacement member is virtually divided into second regions, and the second bending displacement member passes through the center of the second bending displacement member and is parallel to the length direction of the second bending displacement member. When virtually divided into four regions, the center of the first connecting portion is located in either the first region or the second region, and the center of the second connecting portion is the third region or the fourth region. It can be expressed as a configuration located in either region.

  In the above configuration of the drive device of the present invention, the imaginary line parallel to the length direction of the first bending displacement member and the imaginary line parallel to the length direction of the second bending displacement member intersect, It can be expressed that the virtual line parallel to the thickness direction of the first bending displacement member and the virtual line parallel to the thickness direction of the second bending displacement member intersect.

  In the above configuration of the drive device of the present invention, the imaginary line parallel to the length direction of the first bending displacement member and the imaginary line parallel to the length direction of the second bending displacement member are orthogonal to each other, It can be expressed that the virtual line parallel to the thickness direction of the first bending displacement member and the virtual line parallel to the thickness direction of the second bending displacement member are orthogonal to each other.

  Further, in the above-described configuration of the drive device of the present invention, a part of the driven body is arranged in a fan-shaped space formed virtually by the first bending displacement member and the second bending displacement member. It can be expressed as

[Seventh Embodiment]
The drive device of the fifth embodiment has a configuration in which the bending displacement member 51A is fixed by being pressed by a predetermined amount in the direction of the lens barrel 4 (direction of the driven body). Alternatively, the guide shaft is fixed to press the lens barrel 4 in the direction toward the friction member 3. However, in the case of such a configuration, there remains a problem that it is difficult to set the preload because the amount of displacement to be pressed is minute.

  Therefore, in the drive mechanism as described above, a preload mechanism in which the preload is easily set and stable is desired.

(Configuration of the driving device of the present embodiment)
Hereinafter, the driving device of the present embodiment (referred to as the present driving device) will be described. FIG. 20 is a top view showing a schematic configuration of the drive device. The driving device shown in FIG. 20 shows an optimal embodiment applied to a focus adjustment mechanism of a small camera module. FIG. 21 is a side view showing a schematic configuration of the drive device viewed from the line of sight B in FIG. In FIG. 21, the camera module housing is omitted.

  As shown in FIGS. 20 and 21, the present driving device includes a lens barrel 4 ′ as a driven body, a bending displacement member (also referred to as a vibrating member) 91A, a camera module housing 96, a preload spring (preload elasticity). Member) 98 and a drive direction changing member (drive member) 99. In the present driving apparatus, the lens barrel 4 ′ is driven by a driving mechanism including a driving direction changing member 99 and a bending displacement member 91 </ b> A.

  The preload spring 98 is a member that biases the lens barrel 4 ′ with respect to the drive direction conversion member 99. In the present driving device shown in FIGS. 20 and 21, the preload spring 98 is a helical spring. One end of the preload spring 98 is fixed to the camera module housing 96, and the other end is fixed to the lens barrel 4 '. Thereby, the lens barrel 4 ′ is pressed against the driving direction changing member 99 during driving. In FIG. 20, the direction in which the preload spring 98 biases the lens barrel 4 ′ to the drive direction conversion member 99 is a preload direction, and a straight line along the preload direction is a preload direction virtual line L.

  The lens barrel 4 'is a lens barrel having a function of holding a lens. The lens barrel 4 ′ has an annular portion at the center, and a lens is fitted into the annular portion. And it drives to an optical axis direction by the drive mechanism containing the drive direction conversion member 99 and the bending displacement member 91A, and autofocus operation | movement is performed. In the present embodiment, the moving direction in which the lens barrel 4 'moves is treated as a synonym for the optical axis direction. In this specification, the direction in which the optical component fitted in the lens barrel 4 ′ forms an object (the direction of a straight line connecting the lens barrel 4 ′ and the object) is referred to as “optical axis direction”.

  The drive direction conversion member 99 contacts the lens barrel 4 ′, converts the displacement direction to a direction (Z-axis direction) different from the bending displacement direction of the bending displacement member 91A, and drives the driven body (lens barrel 4 ′). .

  The bending displacement member 91A is a bimorph piezoelectric element having a three-layer structure in which two piezoelectric material layers are bonded with a shim interposed therebetween. As shown in FIG. 20, one end of the bending displacement member 91 </ b> A (in this embodiment, an extension of the shim material) is fixed to the camera module housing 96 by bonding, fitting, or the like. The other end is connected to the drive direction conversion member 99. The drive direction conversion member 99 and the bending displacement member 91A may have an integral structure. In this case, the bending displacement member 91 </ b> A has an extending portion that partially extends, and the extending portion serves as the drive direction conversion member 99.

  In the present driving device, the preload spring 98 has one end in the preload direction fixed to the side wall of the camera module housing 96 and the other end fixed to the lens barrel 4 ′. For this reason, when the lens barrel 4 ′ is driven and displaced (moved) in the optical axis direction, the other end of the preload spring 98 is also displaced. The preload spring 98 bends in the optical axis direction and follows the lens barrel 4 ′ while the lens barrel 4 ′ is driven.

(Operating principle 3)
FIG. 22 is a perspective view showing a schematic configuration of the driving device viewed from the line of sight A in FIG. In FIG. 22, only the bending displacement member 91A and the driving direction changing member 99 adhered thereto are extracted and shown.

  As shown in the figure, the bending displacement member 91A includes two piezoelectric material layers 92X and 92Y and a shim material 91 made of metal, and the two piezoelectric material layers 92X and 92Y are crimped with the shim material 91 interposed therebetween. It has a three-layer structure. That is, the bending displacement member 91A is a piezoelectric element having a bimorph structure. The control circuit 97A is a circuit that excites bending displacement of the bending displacement member 91A, and is electrically connected to the two piezoelectric material layers 92X and 92Y. When an alternating signal (voltage) is applied to the bending displacement member 91A by the drive circuit 10, the bending displacement member 91A is bent and displaced in the direction of arrow A.

  The drive direction conversion member 99 includes an S-shaped elastic member 92 and a friction member 93. The friction member 93 is provided on the elastic member 92 and is configured to frictionally engage with the lens barrel 4 ′. The elastic member 92 has one S-shaped end connected to the bending displacement member 91 </ b> A and the other end fixed to the camera module housing 96. For this reason, when the bending displacement member 91A is bent and displaced in the direction of the arrow A, the elastic member 92 is displaced in the direction of the arrow A. The tip of the friction member 93 provided on the elastic member 92 is displaced in the direction of the arrow C (optical axis direction) and frictionally engaged with the lens barrel 4 ′.

  Next, an operation example in which the tip end (the above-described friction member 93) of the drive direction conversion member 99 is driven in an arc and the lens barrel 4 'is driven in the optical axis direction will be described. FIG. 23 is a graph showing a drive voltage waveform applied to the bending displacement member 91A. FIGS. 24A and 24B are explanatory diagrams for explaining the arc driving of the tip of the friction member 93 based on the driving voltage waveform shown in FIG.

  In FIG. 23, a waveform A is a drive voltage waveform applied to the bending displacement member 91A. The drive voltage waveform of waveform A is output from the drive circuit 10. As shown in the figure, the waveform A is a sawtooth drive voltage waveform. Here, the states of the connection points A and B corresponding to the time points (i) to (v) of the waveform A shown in FIG. 23 are shown in FIGS.

  As shown in FIGS. 24A and 24B, when the waveform A is driven, the positions of the connection points A and B change from (i) to (v). That is, the connection points A and B are in the state (i) of FIG. 24 (a) at the time point (i) in FIG. 23, and (ii) in FIG. 24 (a) at the time point (ii) in FIG. 23, the state of (iii) of FIGS. 24 (a) and 24 (b) is reached at the time of (iii) in FIG. 23, and the state (iv) of FIG. 24 (b) is reached at the time of (iv) of FIG. Thus, the state shown in FIG. 24B is in the state shown in FIG. 24B. As the connecting points A and B change to the states (i) to (v) shown in FIGS. 24 (a) and 24 (b) and are displaced, the tip of the friction member 93 is circular as shown. Will be driven.

  At this time, the tip of the friction member 93 is driven in a circular arc by the saw-like drive voltage waveform shown in FIG. 23, and therefore there is a difference between the angular velocity in the driving direction and the angular velocity in the reverse driving direction (that is, (i) to While the angular velocity transitioning to the state (iii) is relatively slow, the angular velocity transitioning to the states (iii) to (v) is relatively high.

  In addition, by appropriately setting the driving voltage waveform, the tip of the friction member 93 can be made to have a difference between the angular acceleration in the driving direction and the angular acceleration in the reverse driving direction. That is, the angular acceleration that transitions to the states (i) to (iii) (driving direction) is relatively slow, while the angular acceleration that transitions to the states (iii) to (v) (reverse driving direction) is relatively The drive voltage waveform can be set so as to be faster. Therefore, by adjusting the friction coefficient of the friction member 93 and the like, the force applied to the contact point between the friction member 93 and the lens barrel 4 ′ in the driving direction causes the static friction force between the friction member 93 and the lens barrel 4 ′. The tip of the friction member 93 cannot slide over the lens barrel 4 ′. On the other hand, since the force applied to the contact between the friction member 93 and the lens barrel 4 ′ exceeds the static friction force between the friction member 93 and the lens barrel 4 ′ in the reverse drive direction, the tip of the friction member 93 is at the lens barrel 4 ′. Can be made to slide. As a result, a difference occurs between the driving force in the driving direction and the driving force in the reverse driving direction, and the lens barrel 4 ′ is driven in the driving direction.

  Further, it is possible to adjust the friction coefficient and the like so that the tip of the friction member 93 slides on the lens barrel 4 ′ in both the driving direction and the reverse driving direction. In this case, the driving force in the driving direction and the driving force in the reverse driving direction are determined by the dynamic friction force and become the same force. However, the driving voltage waveform shown in FIG. 23 sets the displacement time in the driving direction to be long and the displacement time in the reverse driving direction to be short, so that the time during which the dynamic friction force in the driving direction is applied is reverse driving. It becomes longer than the time when the dynamic frictional force of the direction is acting. Therefore, as a result, the lens barrel 4 'is driven in the driving direction.

  In the present driving device, the lens barrel 4 ′ is always in contact with the tip of the friction member 93 by the preload spring 98. For this reason, instead of rotating the arc at the tip of the friction member 93 (a distortion occurs in the bending displacement member 91A, the elastic member 92, the friction member 93, etc.), linear displacement is alternately excited. Even in such a case, it goes without saying that the lens barrel 4 'can be driven.

(About resonance)
As described above, the driving mechanism of the lens barrel 4 ′ in the present driving device is a mechanism in which the driving direction converting member 99 vibrates in the driving direction and frictionally engages with the lens barrel 4 ′ by the vibration of the bending displacement member 91A. It is. In this drive mechanism, the preload spring 98 is an elastic member that biases the lens barrel 4 ′ to the drive direction changing member 99. That is, the drive mechanism of the present drive device can be considered as a spring system including the preload spring 98, the lens barrel 4 ′, the drive direction changing member 99, and the bending displacement member 91A. When the vibration of the bending displacement member 91A is applied to the drive mechanism of the drive device as the spring system, the following resonance phenomenon occurs.

  First, as a first resonance phenomenon, a resonance phenomenon between the vibration of the bending displacement member 91 </ b> A by the drive circuit 10 and the vibration (drive) of the drive direction conversion member 99 can be considered. At this time, the first resonance phenomenon acts in the driving direction of the lens barrel 4 '. In other words, the first resonance phenomenon is a resonance phenomenon in the optical axis direction due to the mass of the lens barrel 4 ′, the bending displacement member 91 </ b> A, and the elasticity of the drive direction conversion member 99.

The natural frequency (resonance frequency) f ₀ of the first resonance phenomenon can be expressed by the following equation (1). In Equation (1), the spring constant in the driving direction due to the elasticity of the bending displacement member 91A and the elasticity of the driving direction conversion member 99 is K ₀ [N / m], and the mass of the lens barrel 4 ′ is M [kg]. ].

The frequency of the drive voltage waveform (waveform A shown in FIG. 23) applied to the bending displacement member 91A and the fundamental frequency f _D. At this time, by setting the fundamental frequency f _D near the natural frequency f ₀ represented by the above formula (1), it is possible to drive the lens barrel 4 'by reducing the amplitude of the drive waveform A . In other words, the fundamental frequency f _D of the drive voltage waveform A by setting so as to approach the natural frequency f _0, the vibration of the bending displacement member 91A, the driving direction changing member 99 vibrating (driving) the first between A resonance phenomenon occurs, and the vibration amplitude of the drive direction conversion member 99 can be increased with the drive waveform A having a small amplitude. Accordingly, the present driving device, with respect to the bending displacement member 91A, it is effective to drive at the fundamental frequency f _D near the natural frequency f _0. However, in the present driving device, for example, when the driving speed of the lens barrel 4 'is set low, or when a large driving voltage is available, from the natural frequency f ₀ different from (e.g. natural frequency f ₀ also small) it is possible to drive the lens barrel 4 'at the fundamental frequency f _D.

  This drive device is configured to urge the lens barrel 4 ′ to the drive direction changing member 99 by a preload spring 98. In such a configuration, as the second resonance phenomenon, a resonance phenomenon between the vibration of the bending displacement member 91A by the drive circuit 10 and the vibration of the preload spring 98 in the preload direction can be considered. At this time, the second resonance phenomenon acts in the preload direction of the preload spring 98. That is, the second resonance phenomenon is a resonance phenomenon in the preload direction due to the elasticity of the preload spring 98.

The natural frequency (resonance frequency) f _P of the second resonance phenomenon can be expressed by the following equation (2). In Equation (2), the spring constant of the preload spring 98 in the preload direction is K _P [N / m], and the mass of the lens barrel 4 ′ is M [kg].

However, strictly speaking, in the second resonance phenomenon, the spring constant caused by the elasticity of the bending displacement member 91A and the driving direction conversion member 99 in the preload direction is affected. However, the lens barrel 4 ′ and the drive direction changing member 99 are not fixed. Therefore, the spring constant resulting from the elasticity in the preload direction is equivalent to the spring constant in the case where the lens barrel 4 ′ and the drive direction conversion member 99 are separated by vibration in the preload direction. Therefore, the second resonance phenomena, the natural frequency (resonance frequency) f _P represented by the formula (2) is important.

As described above, the first resonance phenomenon and the second resonance phenomenon occur in the drive mechanism of the present drive device. Here, the natural frequency f ₀ in the first resonance, the case where the natural frequency f _p of the second resonance are close, an explanation will be made for a driving mechanism of the driving device.

To bending displacement member 91A, is driven at the fundamental frequency f _D near the natural frequency f _0, as described above, the amplitude of the drive voltage waveform applied to the bending displacement member 91A (waveform A shown in FIG. 23) The lens barrel 4 'can be driven with a small voltage, that is, with a low voltage. At this time, due to the first resonance phenomenon, the tip of the friction member 93 of the drive direction conversion member 99 vibrates at the natural frequency f ₀ and also vibrates at the natural frequency f ₀ in the preload direction. The second resonance phenomenon is excited in the preload spring 98 by the vibration component in the preload direction at the tip of the friction member 93. As a result, the lens barrel 4 ′ vibrates in the preload direction, and the contact state between the friction member 93 and the lens barrel 4 ′ becomes unstable. Furthermore, the frictional force acting between the friction member 93 and the lens barrel 4 ′ becomes unstable, and the driving speed and thrust of the lens barrel 4 ′ become unstable.

Further, instability of contact between such friction member 93 and the lens barrel 4 'is a fundamental frequency f _D of the drive waveform is away from the natural frequency f ₀ value (not the value close), and specific This problem also occurs when the frequency f ₀ and the natural frequency f _P are separated. That is, when the second resonance phenomenon is excited, the contact state between the friction member 93 and the lens barrel 4 ′ becomes unstable. Second resonance phenomena, the fundamental frequency f _D of the drive waveform applied to the bending displacement member 91A is excited when approximated to the natural frequency f _p. In the driving device of FIG. 20 and FIG. 21, when the voltage of the drive waveform of the fundamental frequency f _D to the bending displacement member 91A is applied, the tip portion of the friction member 93 will vibrate in the fundamental frequency f _D. By preloading direction of the vibration component of the friction member 93 tip (vibration component of the fundamental frequency f _D), the second resonance is excited in the preload spring 98.

In the present driving device, the fundamental frequency f _D of the drive voltage waveform (alternating signal) applied to the bending displacement member 91A is set to be different from the natural frequency f _P of the preload spring 98. According to this arrangement, when the drive voltage waveform of the fundamental frequency f _D (alternating signal) is applied to the bending displacement member 91A, the friction member 93 in the driving direction changing member 99 will vibrate at the fundamental frequency f _D . The vibration component of the preload direction of the friction member 93, since the vibration at the natural frequency f _P and different fundamental frequency f _D of the preload spring 98, thereby preventing the the second resonance is excited. Thereby, the contact state between the friction member 93 and the lens barrel 4 ′ can be stabilized without the lens barrel 4 ′ vibrating in the preload direction. As a result, in the present driving device, it is possible to realize a preload mechanism using a stable preload spring 98.

  Furthermore, since the contact state between the friction member 93 and the lens barrel 4 ′ becomes stable, it is possible to easily set the preload of the preload spring 98 without considering the vibration component of the friction member 93 in the preload direction. become.

In particular, the fundamental frequency f _D of the drive voltage waveform applied to the bending displacement member 91A is greater than the natural frequency f _P caused by the preload spring 98, thereby facilitating the management of the preload force by the preload spring 98.

The preload F by the preload spring 98 is expressed by the following equation.
F = K _P x, (F: preload, k: spring constant, x: displacement)
The preload spring is designed so that a predetermined preload can be obtained when the preload spring 98 is compressed by 1 mm from the free length. At this time, if the total manufacturing tolerance of the preload spring 98 and other members is 0.1 mm, the preload varies by about 10%. On the other hand, when the preload spring 98 is designed so that a predetermined preload can be obtained when the preload spring 98 is compressed by 0.2 mm from the free length, the preload varies by 50%. That is, a hard spring design the preload spring 98 so that the (spring constant K _P is relatively large spring), increasing the natural frequency f _P, there is a problem that the management of the preload force is difficult. Therefore, who when as small as possible the natural frequency f _P by increasing the natural length of the preload spring 98, thereby facilitating the management of the preload force.

The arrangement of the preload spring 98 in this drive device will be described. The preload spring 98 is preferably arranged so that the imaginary line L in the preload direction does not pass through the center of the lens barrel 4 ′ (cross mark in FIG. 20). The imaginary line L in the preload direction does not pass through the effective area of the optical lens fitted in the lens barrel 4 ′. When the preload spring 98 is arranged so that the virtual line L in the preload direction passes through the center of the lens barrel 4 ′, the spring length of the preload spring 98 is the shortest. As shown in equation (3) described later, the spring constant K _P of the preload spring 98 decreases as the effective number of turns N increases. In the configuration spring length of the preload spring 98 becomes shortest, there is a limit to increase the effective number of turns N, it becomes difficult to reduce the spring constant K _P. Then, it becomes difficult to reduce the natural frequency f _P of the preload spring 98 in the second resonance.

  In short, the helical spring as the preload spring 98 may be configured to penetrate through the tunnel formed in the barrel 4 'wall portion and not through the optical lens. However, when the spring length of the preload spring may be set short, the virtual line L in the preload direction may penetrate the optical lens.

In the drive device shown in FIG. 20, the preload spring 98 is disposed along the side wall 96b of the camera module housing 96, and the preload direction virtual line L does not pass through the center of the lens barrel 4 ′. . By disposing the preload spring 98 along the camera module housing 96 in this way, the spring length of the preload spring 98 can be increased. As a result, the spring constant K _P of the preload spring 98 can be reduced.

The spring constant K _P of the preload spring 98 as a helical spring is generally given by the following formula (3).

From the above formula (3), it can be seen that the spring constant K _P decreases as the spring diameter D or the effective number of turns N increases. Therefore, in order to reduce the spring constant K _P , it is only necessary to increase the spring diameter D or increase the effective number of turns N. When the spring diameter D of the preload spring 98 is increased, it is necessary to set a large installation space for the preload spring 98 in the camera module housing 96. For this reason, in this drive device, the setting of the spring diameter D of the preload spring 98 is limited. On the other hand, the effective number of turns N of the preload spring 98 can be increased by increasing the spring length. In the driving device shown in FIG. 20, since the preload spring 98 is disposed along the side wall 96b of the camera module housing 96, the spring length of the preload spring 98 can be secured long, and the spring constant K _{P is set} to be constant. Can be small. Furthermore, from the above equation (2), the natural frequency f _P of the preload spring 98 in the second resonance phenomenon can be reduced.

  Another effect of the present driving device will be described. In the present drive device, as described above, the preload spring 98 has one end in the preload direction fixed to the side wall of the camera module housing 96 and the other end fixed to the barrel 4 '. For this reason, when the lens barrel 4 ′ is driven and displaced (moved) in the optical axis direction, the other end of the preload spring 98 is also displaced. The preload spring 98 bends in the optical axis direction and follows the lens barrel 4 ′ while the lens barrel 4 ′ is driven.

  As shown in FIG. 20, the preload spring 98 as a helical spring has a structure in which the spring diameter is sufficiently small with respect to the spring length. Therefore, the preload spring 98 has a configuration in which the elasticity in the optical axis direction is small (soft), that is, the spring constant is small. Therefore, when the preload spring 98 is bent in the optical axis direction and follows the lens barrel 4 ′, the load on the lens barrel 4 ′ can be sufficiently reduced.

  Further, since the preload spring 98 has a small elastic spring constant in the optical axis direction, it is possible to set a large amount of displacement (amount to shrink the preload spring 98) for obtaining a predetermined preload. Therefore, when assembling the drive device, it is possible to reduce the variation in the preload due to the variation in the dimensions of the parts.

  Furthermore, the preload spring 98 as a helical spring can be manufactured with reduced variation in elasticity. Therefore, when assembling the drive device, individual differences in the preload of each drive device can be reduced.

(Modification 1)
In the configuration of the present driving device, a modified example of the configuration shown in FIGS. 20 and 21 will be described. 25 and 26 show a schematic configuration of the present drive device as the first modification, FIG. 25 is a top view, and FIG. 26 is a side view seen from the line of sight B in FIG. In FIG. 26, the camera module housing is omitted.

  In the drive device shown in FIGS. 20 and 21, the preload spring 98 is a helical spring. On the other hand, as shown in FIGS. 25 and 26, the present driving device of Modification 1 has a configuration in which the preload spring 98A is a leaf spring. As shown in FIG. 26, the preload spring 98A as a leaf spring has a structure curved in the optical axis direction, and biases the lens barrel 4 ′ to the drive direction conversion member 99 (friction member 93). It has become.

  One end of the preload spring 98A in the preload direction is fixed to the side wall of the camera module housing 96, and the other end is fixed to the lens barrel 4 '. For this reason, when the lens barrel 4 'is driven and displaced (moved) in the optical axis direction, the other end of the preload spring 98A is also displaced. The preload spring 98A is deformed in the optical axis direction and follows the lens barrel 4 'during driving of the lens barrel 4'.

  The spring constant K of the preload spring 98A as a leaf spring is generally given by the following formula (4). Since it is difficult to obtain the spring constant of a curved leaf spring, the spring constant K approximated by a cantilever leaf spring is shown in Equation (4).

From the above equation (4), it can be seen that the spring constant K of the preload spring 98A decreases as the length l increases. Therefore, in order to reduce the spring constant K, the length l should be increased. 25 and 26, since the preload spring 98A is disposed along the side wall 96b of the camera module housing 96, the spring length l of the preload spring 98A can be secured long, and the spring The constant K can be reduced. Further, from the equation (2), it is possible to reduce the natural frequency f _P of the preload spring 98A in the second resonance.

(Modification 2)
In the configuration of the present driving device, a modified example of the configuration shown in FIGS. 20 and 21 will be described. 27 and 28 show a schematic configuration of the present driving device as the second modification, FIG. 27 is a top view, and FIG. 28 is a side view seen from the line of sight B in FIG. In FIG. 28, the camera module housing is omitted.

  As shown in the figure, in the driving device of the second modification, a sliding member 98C is disposed between the preload spring 98B and the lens barrel 4 '. The sliding member 98C includes a ball 98D that contacts the lens barrel 4 '. A preload spring 98B is fixed to one end of the sliding member 98C in the preload direction, and the other end is in contact with the lens barrel 4 'via a ball 98D. The ball 98D is provided to reduce the sliding resistance of the lens barrel 4 'with respect to the sliding member 98C.

  In the driving apparatus of the second modification, the preload spring 98B biases the lens barrel 4 'to the driving direction changing member 3 (friction member 93) via the sliding member 98C. The sliding member 98C is made of a material having a volume larger than that of the driving direction changing member 99 and a relatively large specific gravity such as metal. Accordingly, the sliding member 98C has a larger mass than the driving direction changing member 99.

In the drive device of the second modification, the natural frequency (resonance frequency) f _P of the second resonance phenomenon can be expressed by the following equation (5). In equation (5), the spring constant of the preload spring 98B in the preload direction is K _P [N / m], the mass of the lens barrel 4 ′ is M [kg], and the mass of the sliding member 98C is M _s [kg]. ].

As shown in the above equation (5), the resonance frequency f _P decreases as the mass M _s of the sliding member 98C and the mass M of the lens barrel 4 ′ increase. Therefore, in the driving device of the second modification, by increasing the mass M _s of the sliding member 98C, it is possible to reduce the resonance frequency f _P of the preload spring 98B according to the second resonance.

Furthermore, according to the driving device of the second modification, the sliding member 98C and the lens barrel 4 ′ are not fixed, and the sliding resistance of both members is reduced by the ball 98D. Thus, by reducing the sliding resistance between the sliding member 98C and the lens barrel 4 ′, the sliding member 98C to which the preload spring 98B is coupled causes the vibration of the bending displacement member 91A and the vibration of the driving direction conversion member 99. The first resonance phenomenon generated by (driving) is not affected by the mass of the sliding member 98C. Therefore, in the driving device of the second modification, if the sliding resistance between the sliding member 98C and the lens barrel 4 ′ is sufficiently small, the increase in the mass of the driving direction changing member 99 due to the addition of the sliding member 98C is not affected. The natural frequency (resonance frequency) f ₀ of the first resonance phenomenon can be expressed by the above equation (1).

As described above, in the driving device of Modification 2, the first resonance phenomenon is not affected by the mass of the sliding member 98C by reducing the sliding resistance between the sliding member 98C and the lens barrel 4 ′. while manner, it is possible to reduce the resonance frequency f _P of the preload spring 98B according to the second resonance.

  27 and 28 has a configuration in which the sliding resistance between the sliding member 98C and the lens barrel 4 'is reduced by the ball 98D. However, the driving device of the second modification is not limited to this configuration. For example, in the configuration in which lubricating oil is injected between the sliding member 98C and the lens barrel 4 ′, or in the sliding member 98C A structure in which a lubricating layer made of a solid lubricating material (carbon or the like) having a relatively low frictional resistance is formed on a surface (sliding surface) facing the lens barrel 4 ′ may be used.

(Modification 3)
In the configuration of the present driving device, a modified example of the configuration shown in FIGS. 20 and 21 will be described. FIG. 29 is a top view showing a schematic configuration of the present drive device as the third modification.

  As shown in the figure, in the driving device of the third modification, a sliding member 98C 'and a ball 98D are disposed between the preload spring 98' and the lens barrel 4 '. Since the configuration of the sliding member 98C 'and the ball 98D is the same as that of the driving device of the second modification, the description thereof is omitted.

  In the driving device of the third modification, a preload spring 98 ′ as a leaf spring is arranged along the side wall 96 d facing the bending displacement member 91 </ b> A in the camera module housing 96. The preload spring 98 'has a structure bent with respect to the side wall 96d. One end of the preload spring 98 'is fixed to the side wall 96d, and the other end opposite to the fixed one end is fixed to the sliding member 98C'. With this configuration, the preload spring 98 ′ is elastic at the bent portion, and the lens barrel 4 ′ is biased toward the drive direction changing member 99 via the sliding member 98 </ b> C ′.

Thus, since the preload spring 98 'is disposed along the side wall 96d facing the bending displacement member 91A, the spring length of the preload spring 98' as a leaf spring is increased, and the spring constant can be reduced. . The sliding member 98C ′ is made of a material having a volume larger than that of the driving direction changing member 99 and having a relatively large specific gravity such as metal. As a result, the sliding member 98C ′ has a larger mass than the driving direction conversion member 99. Therefore, the resonance frequency f _P of the preload spring 98 ′ due to the second resonance phenomenon can be reduced.

(Modification 4)
In the configuration of the present driving device, a modified example of the configuration shown in FIGS. 20 and 21 will be described. FIG. 30 is a top view showing a schematic configuration of the present drive device as the fourth modification.

  As shown in the drawing, in the driving device of the third modification, a sliding member 98C ″ and a ball 98D are disposed between the preload spring 98 ″ and the lens barrel 4 ′. Since the configuration of the sliding member 98C ″ and the ball 98D is the same as that of the driving device of the second modification, the description thereof is omitted.

  In the driving device of the third modification, a preload spring 98 ″ as a leaf spring is arranged along the side wall 96 b perpendicular to the bending displacement member 91 A in the camera module housing 96. The preload spring 98 'has a structure bent with respect to the side wall 96b. One end of the preload spring 98 ″ is fixed to the side wall 96 b, and the other end opposite to the fixed one end is fixed to the sliding member 98 C ″. With this configuration, the preload spring 98 ″ is elastic at the bent portion, and urges the lens barrel 4 ′ toward the drive direction changing member 99 via the sliding member 98 C ″.

Since the preload spring 98 ″ is disposed along the side wall 96b, the spring length of the preload spring 98 ″ as a leaf spring is increased, and the spring constant can be decreased. The sliding member 98C ″ is made of a material having a volume larger than that of the driving direction changing member 99 and having a relatively large specific gravity such as metal. As a result, the sliding member 98 </ b> C ″ has a larger mass than the driving direction changing member 99. Therefore, the resonance frequency f _P of the preload spring 98 ″ due to the second resonance phenomenon can be reduced.

  In the driving device of the fourth modification, the sliding member 98C ″ and the lens barrel 4 ′ are not fixed, and the sliding resistance of both members is reduced by the ball 98D. In this way, by making the sliding resistance between the sliding member 98C ″ and the lens barrel 4 ′ sufficiently small, the preload spring 98 ″ as a leaf spring can move in the direction of the optical axis during the driving of the lens barrel 4 ′. Will not bend. Therefore, as shown in FIG. 30, the degree of freedom of arrangement of the preload spring 98 ″ as a leaf spring is increased, for example, the direction parallel to the optical axis direction is the width direction of the preload spring 98 ″. Further, by setting the direction parallel to the optical axis direction as the width direction of the preload spring 98 ″, the space between the camera module housing and the lens barrel 4 ′ can be reduced.

  In the present embodiment, the configuration based on the drive device of the fifth embodiment has been described. However, the problem that the setting of the preload is difficult is not limited to the drive device of the fifth embodiment. This is also a problem that applies to a drive device (Patent Document 5) that includes a piezoelectric element that can expand and contract in the drive direction of the cylinder (optical axis direction) and a drive member that is connected to one end of the piezoelectric element.

  In the driving device disclosed in Patent Document 5, the driving direction of the lens barrel and the extending direction of the piezoelectric element coincide with each other, and the driving member is displaced only in the extending direction of the piezoelectric element, with respect to the extending direction of the piezoelectric element. It is considered that there is no vibration component in the vertical direction. However, in reality, the driving member vibrates in a direction perpendicular to the extending direction of the piezoelectric element. For this reason, when the natural frequency (resonance frequency) of the preload spring matches the frequency of vibration in the direction perpendicular to the extending direction of the piezoelectric element, the preload spring may resonate. For this reason, there is a problem that the frictional force acting between the driving member and the lens barrel becomes unstable, and the driving speed of the lens barrel becomes unstable.

  By applying the configuration of the present embodiment, it is possible to solve the problem in the driving device disclosed in Patent Document 5. That is, this embodiment includes a drive mechanism that drives a driven body, and the drive mechanism includes a vibration member and a drive member connected to the vibration member, and the drive member is driven by vibration of the vibration member. The present invention can be applied to all drive devices that come into contact with the drive body and frictionally drive the driven body. The preload elastic member that biases the driven body against the drive member, and the vibration member Control means for applying an alternating electrical signal and controlling the vibration of the vibration member, and the fundamental frequency of the alternating signal is the resonance of the preload direction due to the elasticity of the preload elastic member and the mass of the driven body. It is characterized by being different from the resonance frequency.

  According to the above configuration, when an alternating signal having a fundamental frequency is applied to the vibration member, the drive member vibrates at the fundamental frequency. Since the vibration component in the preload direction of the driving member vibrates at a fundamental frequency different from the resonance frequency of the preload elastic member, the resonance phenomenon in the preload direction due to the elasticity of the preload elastic member and the mass of the driven body. It will not be excited. Thereby, the contact state between the drive member and the driven body can be stabilized without the driven body vibrating in the preload direction. As a result, according to the above configuration, it is possible to realize a preload mechanism in which the frictional force acting between the driving member and the driven body is stable and the driving speed of the driven body is stable.

  As described above, the present drive device includes a preload elastic member that biases the driven body against the drive member, and a control unit that controls the vibration of the vibration member by applying an alternating electrical signal to the vibration member. The basic frequency of the alternating signal is different from the resonance frequency of the resonance phenomenon in the preload direction caused by the elasticity of the preload elastic member and the mass of the driven body.

  Therefore, it is possible to realize a preload mechanism in which the frictional force acting between the driving member and the driven body is stable and the driving speed of the driven body is stable.

[Eighth Embodiment]
In the driving devices of the first to seventh embodiments, one end of the driving direction changing member is connected to the bending displacement member, and the other end is connected to and supported by the preload elastic member or another bending displacement member. . That is, both ends of the driving direction conversion member sandwiching the contact portion with the driven body are both supported and fixed. However, in such a configuration, when the bending displacement member connected to one end of the driving direction conversion member is bent and displaced, the other end of the driving direction conversion member is connected or supported by the preload elastic member or another bending displacement member. The displacement width is limited. As a result, the movement of the other end of the drive direction changing member is restricted, and the vibration amplitude of the contact portion with the driven body is reduced. Therefore, in the driving devices of the first to seventh embodiments, there remains a problem that the driving efficiency of the driven body with respect to the bending displacement width of the bending displacement member deteriorates.

  Moreover, the adhesion process for fixing another bending displacement member to the said other end of a drive direction conversion member is needed, The subject that the assembly man-hour of a drive device increases and cost becomes high remains.

  The drive device of the present embodiment (hereinafter referred to as the present drive device) solves the above problems.

(Configuration of this drive unit)
The drive device will be described below with reference to FIGS. 31 and 32. FIG. FIG. 31 is a top view showing a schematic configuration of the present driving device. The driving device shown in FIG. 31 shows an optimum embodiment applied to an autofocus adjustment mechanism of a small camera module.

  As shown in FIG. 31, the present driving device includes a bending displacement member 101A, an elastic member (driving direction converting member) 102, a friction member (driving direction converting member: contact portion) 103, and a lens barrel (driven body). 4 ″, a guide shaft 105, and a camera module housing 106.

  In the present driving device, the bending displacement member 101A is fixed to the camera module housing 106 at one end thereof. A driving direction displacement member composed of an elastic member 102 and a friction member 103 is connected to the other end of the bending displacement member 101A opposite to the camera module housing 106. The friction member 103 is in frictional engagement with the lens barrel 4 ″ at its tip.

  In addition, the driving device is provided with a guide shaft 105 that guides the movement of the lens barrel 4 ″ in the optical axis direction. The guide shaft 105 is a rod-like body extending in the optical axis direction, and is fixed so as to be perpendicular to the bottom surface of the camera module housing 106.

  In the present driving device, the friction member 103 and the lens barrel 4 ″ are pressed with a predetermined force using the guide shaft 105, the bending displacement member 101A, and the elasticity of the elastic member 102. .

  Similarly to the driving devices of the first to seventh embodiments, when a control voltage is applied to the bending displacement member 101A by a driving circuit (control means) (not shown), the lens barrel 4 '' is driven in the z direction. The That is, the bending displacement member 101 </ b> A vibrates in the x-direction due to the application of the control voltage by the drive circuit. When the bending displacement vibration of the bending displacement member 101A is excited, the friction engagement portion with the lens barrel 4 '' in the friction member 103 is z due to the action of the driving direction changing member including the elastic member 102 and the friction member 103. Vibration is displaced in the direction. The lens barrel 4 ″ is driven in the z direction by the displacement vibration. Note that the control means for applying a control voltage to the bending displacement member 101A and the drive waveforms by the control means are the same as those of the drive devices of the first to seventh embodiments, and thus description thereof is omitted.

  FIG. 32 is a perspective view showing a schematic configuration of the driving device viewed from the line of sight X in FIG. In FIG. 32, only the bending displacement member 101A and the driving direction changing member bonded thereto are extracted and shown.

  As shown in FIG. 32, the present driving device includes only one bending displacement member 101A. The bending displacement member 101 </ b> A is connected to a driving direction conversion member including a U-shaped elastic member 102 and a friction member 103. More specifically, the bending displacement member 101 </ b> A is connected to the elastic member 102. The end of the elastic member 102 opposite to the connecting portion with the bending displacement member 101A is not connected to other members but is a free end. In other words, the present driving device includes a single bending displacement member 101A and a driving direction conversion member made up of the elastic member 102 and the friction member 103, and the driving direction conversion member is connected to the bending displacement member 101A, and This is a configuration that is not in contact with other members other than the frictional engagement point (friction member 103) with the lens barrel 4 ''.

  Thus, since the end of the elastic member 2 opposite to the connecting portion with the bending displacement member 101A is a free end, when the bending displacement member 101A is bent and displaced, the driving direction conversion member (elastic member 102). The displacement width of the other end is not limited by connection / support with other members. As a result, the vibration amplitude of the contact portion (friction member 103) with the lens barrel 4 "is not reduced, and the driving efficiency of the lens barrel 4" is improved. Furthermore, an adhesive process for fixing another bending displacement member to the end of the elastic member 2 opposite to the connecting portion with the bending displacement member 101A is not required, and the number of assembly steps of the drive device can be reduced.

  Hereinafter, the driving voltage waveform by the control means and the principle of the optical axis direction driving operation of the lens barrel 4 ″ based on the driving voltage waveform in the present driving device will be described.

(Operating principle)
FIG. 33 is a side view showing a schematic configuration of the bending displacement member 101A, the driving direction conversion member including the elastic member 102 and the friction member 103, and the lens barrel 4 ″ as viewed from the line of sight Y in FIG. As shown in the figure, the friction member 103 is fixed to the elastic member 102 by an adhesive β1. In FIG. 33, the bending displacement direction of the bending displacement member 101A is the x direction. In the present driving device, the free end of the elastic member 102 repeats separation and contact with the lens barrel 4 ″ in the x direction in accordance with the bending displacement vibration of the bending displacement member 101A. Here, the displacement of the free end of the elastic member 102 or the bending displacement member 101A in the direction away from the lens barrel 4 ″ is referred to as “displacement in the + x direction”. Further, the displacement in the direction in contact with the lens barrel 4 ″ is referred to as “displacement in the −x direction”. FIG. 33A shows a state when the bending displacement member 101A is displaced most in the + x direction, and FIG. 33B shows a state when the bending displacement member 101A is displaced most in the −x direction. Indicates. FIG. 33 (c) shows a state when the resonance phenomenon of the elastic member 102 occurs.

  In this drive device, the control voltage applied to the bending displacement member 101A can be set so that the displacement vibration frequency of the bending displacement member 101A approaches the resonance frequency of the elastic member 102. Thereby, a resonance phenomenon occurs in the elastic member 102, and the vibration amplitude of the free end of the elastic member 102 can be further increased. Hereinafter, the case where the resonance phenomenon of the elastic member 102 is not used and the case where the resonance phenomenon of the elastic member 102 is used will be described in more detail.

(When the resonance phenomenon of the elastic member 102 is not used)
When the resonance phenomenon of the elastic member 102 is not used, the control voltage is set so that the displacement vibration frequency of the bending displacement member 101A is lower than the resonance frequency of the elastic member 102. The state when the bending displacement member 101A is maximum displaced in the + x direction is the state shown in FIG. 33A, and the state when the bending displacement member 101A is maximum displaced in the −x direction is shown in FIG. Various members are arranged so as to be in the state shown in 33 (b).

  When the bending displacement member 101A is displaced and vibrated in the x direction, the vibration of the free end of the elastic member 102 is as shown in FIG. 33 (a), FIG. 33 (b), and FIG. 33 (a). It becomes a vibration that repeats in order. Then, the contact portion of the friction member 103 with the lens barrel 4 ″ is oscillated and displaced in the driving direction (z direction).

  In the vibration displacement in the driving direction of the contact portion, the control voltage applied to the bending displacement member 101A is controlled so that a difference in displacement speed or displacement acceleration occurs between the forward path and the return path. As a result, based on the same principle as the above-described operation principles 1 to 3, a slip-stick phenomenon or a difference in slip period occurs between the forward path and the return path, and the lens barrel 4 "is driven.

(When using the resonance phenomenon of the elastic member 102)
The displacement of the elastic member 102 described above is approximately 180 degrees in phase with respect to the displacement vibration of the free end of the elastic member 102 with respect to the bending vibration displacement of the bending displacement member 101A (the connecting portion of the elastic member 102 to the bending displacement member 101A). The displacement is shifted. This displacement is due to the state in which the lens barrel 4 ″ and the friction member 103 are pressed, and the elastic member 102 has elasticity.

  When the control voltage is set so that the displacement vibration frequency of the bending displacement member 101A is the same as or close to the resonance frequency of the elastic member 102, a resonance phenomenon occurs in the elastic member 102. Thereby, the vibration amplitude of the free end of the elastic member 102 becomes large. As a result, when the bending displacement member 101A is displaced and vibrated in the x direction, the vibration of the free end of the elastic member 102 is in the state of FIG. 33A, the state of FIG. 33B, and the state of FIG. The state, the state of (b) in FIG. 33, and the state of (a) in FIG. Then, the contact portion of the friction member 103 with the lens barrel 4 ″ is oscillated and displaced in the driving direction (z direction).

  In the vibration displacement in the driving direction of the contact portion, the control voltage applied to the bending displacement member 101A is controlled so that a difference in displacement speed or displacement acceleration occurs between the forward path and the return path. As a result, based on the same principle as the above-described operation principles 1 to 3, a slip-stick phenomenon or a difference in slip period occurs between the forward path and the return path, and the lens barrel 4 "is driven.

  In the above description, for the sake of simplicity, the description has been given of the case where the displacement vibration of the free end of the elastic member 102 is displaced by approximately 180 degrees with respect to the bending vibration displacement of the bending displacement member 101A. However, the present driving device is not limited to a configuration in which the phase difference between the bending vibration displacement of the bending displacement member 101A and the displacement vibration of the free end of the elastic member 102 is 180 degrees. If there is a phase difference between the bending vibration displacement of the bending displacement member 101A and the displacement vibration of the free end of the elastic member 102, the contact portion of the friction member 103 with the lens barrel 4 '' is displaced in the driving direction. '' Can be driven.

  In particular, when the phase difference is close to 90 degrees, the contact portion of the friction member 103 with the lens barrel 4 ″ moves elliptically in the driving direction (z direction). Then, a difference in frictional force is generated between the forward path and the backward path, so that the lens barrel 4 ″ is driven. In this case, by controlling the control voltage applied to the bending displacement member 101A as described above, the lens barrel 4 ″ is driven without causing a difference in displacement speed or displacement acceleration between the forward path and the backward path. be able to.

  At this time, the rotational direction of the elliptical motion varies depending on whether the phase difference is close to +90 degrees or -90 degrees. Therefore, the bending vibration frequency may be selected by changing the bending vibration frequency of the bending displacement member 101A so that the phase difference is close to +90 degrees or the phase difference is close to −90 degrees. Therefore, even if a drive waveform that does not actively cause a difference in the acceleration of the outward trip, such as a sin waveform or a square wave with a duty of approximately 50%, is used as the waveform of the control voltage applied to the bending displacement member 101A. By changing the bending vibration frequency of 101A, reciprocal driving becomes possible.

[Ninth Embodiment]
The drive device of the present embodiment (hereinafter referred to as the drive device) will be described below with reference to FIGS. FIG. 34 is a perspective view showing a schematic configuration of the drive device. In FIG. 34, only the bending displacement member 101A and the driving direction changing member bonded thereto are extracted and shown. In the present embodiment, for convenience of explanation, members having the same functions as those described in the eighth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 34, the present drive device includes only one bending displacement member 101A, as in the eighth embodiment. The end of the elastic member 102 opposite to the connecting portion with the bending displacement member 101A is not connected to other members but is a free end. In the present driving device, a mass increasing member 107 that increases the mass of the free end is provided at the free end of the elastic member 102. Examples of the material of the mass increasing member 107 include a material having a relatively large specific gravity such as tungsten lead.

  Below, the effect | action of the mass increase member 107 in this drive device is demonstrated.

(Operation of the mass increasing member 107)
Since the mass increasing member 107 is provided at the free end of the elastic member 102, the mass of the free end of the elastic member 102 is larger than the mass of the connecting portion with the bending displacement member 101A. As a result, the vibration amplitude of the free end of the elastic member 102 is increased, the displacement amplitude of the contact portion of the friction member 103 with the lens barrel 4 ″ is increased, and the driving efficiency is improved.

  Further, the mass increasing member 107 also has an effect of reducing the resonance frequency of the elastic member 102. This action is beneficial, for example, in a configuration in which the resonance frequency of the bending displacement member 101A is smaller than the resonance frequency of the elastic member 102. Specifically, by providing the mass increasing member 107 at the free end of the elastic member 102, the resonance frequency of the elastic member 102 can be reduced, and can approach the resonance frequency of the bending displacement member 101A. The driving efficiency of the lens barrel 4 ″ can be improved by utilizing the resonance phenomenon of the elastic member 102.

(Modification 5)
In the configuration of the present driving device, a modified example of the configuration shown in FIG. 34 will be described. FIG. 35 is a side view showing a schematic configuration of the present drive device as the fifth modification. In FIG. 35, only the bending displacement member 101A and the driving direction changing member bonded thereto are extracted and shown.

  The configuration shown in FIG. 34 is a configuration in which the mass increasing member 107 is provided at the free end of the elastic member 102, but the present driving device is not limited to this configuration. The mass increasing member 107 may be arranged so that the mass of the free end of the elastic member 102 is larger than the mass of the connecting portion with the bending displacement member 101A. As shown in FIG. 35, the mass increasing member 107A may be disposed in the vicinity of the connecting portion of the elastic member 102 with the bending displacement member 101A.

  Hereinafter, an operation of the mass increasing member 107A in the present driving device will be described.

(Operation of the mass increasing member 107A)
Since the mass increasing member 107A is provided in the vicinity of the connecting portion of the elastic member 102 with the bending displacement member 101A, the mass of the connecting portion with the elastic member 102 in the bending displacement member 101A is the opposite end ( It becomes larger than the mass of the end portion fixed to the camera module housing 106. As a result, the vibration amplitude of the bending displacement member 101A increases. That is, the amplitude for exciting the elastic member 102 increases. As a result, the vibration amplitude of the elastic member 102 increases, the displacement amplitude of the contact portion of the friction member 103 with the lens barrel 4 ″ increases, and the driving efficiency is improved.

  The mass increasing member 107A also has an effect of reducing the resonance frequency of the bending displacement member 101A. This effect is beneficial, for example, in a configuration in which the resonance frequency of the bending displacement member 101A is higher than the resonance frequency of the elastic member 102. Specifically, by providing the mass increasing member 107A in the vicinity of the connecting portion of the elastic member 102 with the bending displacement member 101A, the resonance frequency of the bending displacement member 101A is reduced and approaches the resonance frequency of the elastic member 102. be able to. Then, the driving efficiency of the lens barrel 4 ″ can be improved by utilizing the resonance phenomenon of the bending displacement member 101 </ b> A.

  The configuration shown in FIG. 35 is a configuration in which the mass increasing member 107A is disposed in the vicinity of the connecting portion of the elastic member 102 with the bending displacement member 101A. However, the present driving device is not limited to this configuration.

  For example, as shown in FIG. 36, the mass increasing members 107B and 107C may be arranged on the bending displacement member 101A. In FIG. 36, the mass increasing members 107B and 107C are configured to sandwich the bending displacement member 101A in the bending displacement direction.

  Even in the configuration shown in FIG. 36, the mass increasing members 107B and 107C have the above-described actions, that is, the actions of improving the driving efficiency of the lens barrel 4 '' and reducing the resonance frequency of the bending displacement member 101A. is there.

  In the present driving device, the method of bringing the resonance frequency close to each other between the bending displacement member 101A and the elastic member 102 is described in the above section (Operation of the mass increase member 107) and (Operation of the mass increase member 107A). It is not limited to the matter. For example, the length, width, thickness, shape and elasticity of the bending displacement member 101A, and the length, width, thickness, shape and elasticity of the elastic member 102 may be devised. Moreover, the system which sets the resonance frequency of 101 A of bending displacement members by the increase / decrease in the mass of the whole elastic member 102 may be sufficient. Further, the mass increasing members 107 and 107A may be formed integrally with the driving direction changing member (elastic member 102). Furthermore, the mass increasing members 107 and 107A may be formed as an extension portion in which the driving direction changing member (elastic member 102) extends to the opposite side to the connecting portion with the bending displacement member 101A.

  The present driving device can be restated in the following expression.

  That is, this drive device includes a single bending displacement member and a driving direction conversion member, and the driving direction conversion member contacts other members except for a connection point with the bending displacement member and a friction engagement point with the driven body. It can be expressed as not configured.

  According to this configuration, it is possible to drive a single bending displacement member, and to improve the degree of design freedom due to cost reduction by eliminating the step of bonding the other end of the elastic member and the need for a fixing structure. There is an effect. Furthermore, since the amplitude of the friction engagement portion of the friction member can be increased as compared with the case where the other end is fixed, the driving efficiency is improved.

  In addition, the driving device includes a single bending displacement member and a driving direction conversion member, and the driving direction conversion member has a mass at one end facing a connection point with the bending displacement member with a friction engagement point with the driven body interposed therebetween. It can be expressed as a configuration having an increasing member.

  According to this configuration, it is possible to increase the vibration amplitude of the elastic member and to bring the resonance frequency of the elastic member closer to the resonance frequency of the bending displacement member, thereby improving the driving efficiency.

  In addition, the present driving device can be expressed as a configuration that includes a single bending displacement member and a driving direction conversion member, and includes a mass increasing member on a connection point between the bending displacement member and the driving direction conversion member. it can.

  In addition, the present driving device can be expressed as a configuration including a single bending displacement member and a driving direction conversion member, and a mass increasing member on the bending displacement member.

  According to this configuration, it is possible to increase the vibration amplitude of the elastic member and to bring the resonance frequency of the bending displacement member closer to the resonance frequency of the elastic member, thereby improving the driving efficiency.

  Moreover, this drive device can be expressed as the configuration in which the mass increasing member is integrally formed with the drive direction changing member in the above configuration.

  Furthermore, this drive device can be expressed as the configuration in which the mass increasing member is formed as an extension of the drive direction changing member in the above configuration.

  Further, in the above configuration, the drive device can be expressed as a configuration in which the resonance frequency of the bending displacement member having the drive direction conversion member as a mass substantially matches the single resonance frequency of the drive direction conversion member.

  Since this driving device can realize a reduction in size and height of the device, it can be applied to a lens driving purpose in an optical device such as a photographing lens of a camera.

The structure of the drive device of one Embodiment of this invention is shown, (a) is a perspective view, (b) is a disassembled perspective view. (A) is the side view which showed the positional relationship of the bending displacement member, an elastic member, and a friction member in the drive device of FIG. 1 (a), (b), (b) is FIG. 1 (a). -It is the top view which showed the structure of the drive device of (b). (A) is the side view which showed the positional relationship of the bending displacement member, the elastic member, and the friction member in the drive device of other embodiment of this invention, (b) is other embodiment of this invention. It is the top view which showed the structure of the drive device. (A) is the side view which showed the positional relationship of the bending displacement member, the elastic member, and the friction member in the drive device of further another embodiment of this invention, (b) is other implementation of this invention. It is the top view which showed the structure of the drive device of a form. (A) is the side view which showed the positional relationship of the bending displacement member, the elastic member, and the friction member in the drive device of further another embodiment of this invention. (A) is the side view which showed the positional relationship of the bending displacement member, the elastic member, and the friction member in the drive device of further another embodiment of this invention, (b) is other another of this invention. It is the top view which showed the structure of the drive device of embodiment. (A) is the side view which showed the positional relationship of the bending displacement member, the elastic member, and the friction member in the drive device of further another embodiment of this invention, (b) is other another of this invention. It is the top view which showed the structure of the drive device of embodiment. (A)-(g) is the perspective view which showed an example of the structure of the drive direction conversion member applicable to this invention. It is the perspective view which showed an example of the structure of the bending member and elastic member which can be applied to this invention. (A) is explanatory drawing for demonstrating the fixation concept of the bending displacement member in the drive device of the 1st-5th embodiment, (b) is a bending displacement member applicable to the drive device of this invention. It is explanatory drawing for demonstrating an example of fixation. It is sectional drawing which shows the structure of the imaging device which accommodated the drive device shown by FIG. 1 (a), (b) in the camera module housing | casing. The structure of a piezoelectric element having a bimorph structure is shown, (a) is a plan view, (b) is a side view, and (c) is a diagram showing the bending displacement of the piezoelectric element. It is a graph which shows an example of the drive voltage waveform applied to two bending displacement members. (A)-(c) is explanatory drawing for demonstrating the ellipse drive of the front-end | tip part of a friction member based on the drive voltage waveform shown by FIG. It is a graph which shows an example of the drive voltage waveform applied to two bending displacement members. (A) * (b) is explanatory drawing for demonstrating the circular arc drive of the front-end | tip part of a friction member based on the drive voltage waveform shown by FIG. It is explanatory drawing for demonstrating circular arc drive of the front-end | tip part of the friction member in the drive device shown by FIG. 6 (a), (b). (A)-(c) is explanatory drawing which shows an example of the locus | trajectory of the front-end | tip of a friction member in arrangement | positioning of the friction member shown by FIG.8 (e). (A) * (b) is explanatory drawing which shows an example of the locus | trajectory of the front-end | tip of a friction member in arrangement | positioning of the friction member shown by FIG.8 (e). It is a top view which shows schematic structure of the drive device in further another embodiment of this invention. It is a side view which shows schematic structure of the drive device seen from the visual line B in FIG. It is a perspective view which shows schematic structure of the drive device seen from the eyes | visual_axis A in FIG. It is a graph which shows the drive voltage waveform applied to a bending displacement member. (A) * (b) is explanatory drawing for demonstrating circular arc drive of the front-end | tip part of a friction member based on the drive voltage waveform shown by FIG. FIG. 10 is a top view illustrating a schematic configuration of a drive device according to a first modification. FIG. 26 is a side view of the drive device of Modification 1 as viewed from the line of sight B in FIG. 25. FIG. 10 is a top view illustrating a schematic configuration of a drive device according to a second modification. It is the side view of the drive device of the modification 2 seen from the line of sight B in FIG. FIG. 11 is a top view illustrating a schematic configuration of a drive device according to Modification 3. FIG. 10 is a top view illustrating a schematic configuration of a drive device according to Modification 4; It is a top view which shows schematic structure of the drive device in further another embodiment of this invention. FIG. 32 is a perspective view showing a schematic configuration of the drive device viewed from a line of sight X in FIG. 31. FIG. 32 is a side view illustrating a schematic configuration of a bending displacement member, a driving direction conversion member including an elastic member and a friction member, and a lens barrel as viewed from the line of sight Y in FIG. 31, and FIG. The state when greatly displaced is shown, (b) shows the state when the bending displacement member is most displaced in the -x direction, and (c) shows the state when the resonance phenomenon of the elastic member occurs. . It is a perspective view which shows schematic structure of the drive device in further another embodiment of this invention. FIG. 10 is a perspective view showing a schematic configuration of the present drive device as a fifth modification. FIG. 10 is a perspective view showing a schematic configuration of the present drive device as a fifth modification. It is explanatory drawing for demonstrating the structure of the drive device of the prior art example A.

Explanation of symbols

1A bending displacement member (first bending displacement member)
1B bending displacement member (second bending displacement member)
2 Elastic member (drive direction conversion member)
3 Friction member (drive direction conversion member; contact part)
4 Lens barrel (driven body)
5 Guide shaft 6 Camera module housing (housing)
7A, 7B Drive circuit (control means)
98 Preload spring (preload elastic member)
98C Sliding member 98D Ball 107, 107A, 107B, 107C Mass increasing member

Claims (17)

A drive device comprising a drive mechanism for driving a driven body,
The drive mechanism is
As a bending displacement member that is partially fixed and whose bending displacement is excited by electrical control , a first bending displacement member that bends in the first bending displacement direction, and a second that is orthogonal to the first bending displacement direction. A second bending displacement member bent in the bending displacement direction;
Drive that is connected to the first and second bending displacement members, contacts the driven body, changes the driving direction to a direction different from the first and second bending displacement directions, and drives the driven body. A direction changing member,
The connecting portion between the first bending displacement member and the driving direction changing member is a first connecting portion, the connecting portion between the second bending displacement member and the driving direction changing member is a second connecting portion, When the first straight line in the direction perpendicular to the drive direction of the driven body is drawn in a plane including the first and second connection portions in the drive direction conversion member, the first and second connection portions are: An imaginary line connecting these connecting portions is arranged to intersect the first straight line,
When a straight line perpendicular to the surface including the first and second connecting portions is a second straight line, the contact portion where the drive direction changing member contacts the driven body passes through the second straight line, And arranged so as to protrude in the direction of the second straight line,
When the first and second bending displacement members draw a straight line connecting any one point on the first bending displacement member and any one point on the second bending displacement member, A drive device, wherein the drive device is arranged so that there is at least one straight line passing through the driven body . A housing capable of accommodating the first and second bending displacement members and the driving direction conversion member;
The casing has a prismatic shape, and the first and second bending displacement members are arranged along two side wall surfaces adjacent to each other among the plurality of sidewalls forming the prismatic shape. ,
The drive device according to claim 1, wherein the drive direction changing member is arranged at a corner portion formed by the two side wall surfaces. A housing capable of accommodating the first and second bending displacement members and the driving direction conversion member;
The casing has a prismatic shape, and the first and second bending displacement members are arranged along only one of the plurality of sidewalls forming the prismatic shape. The drive device according to claim 1. A bending displacement of the first and second bending displacement members, comprising: a first driving circuit that drives a voltage to the first bending displacement member; and a second driving circuit that drives a voltage to the second bending displacement member. Control means for controlling
4. The drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are different from each other. 5. Drive device. A bending displacement of the first and second bending displacement members, comprising: a first driving circuit that drives a voltage to the first bending displacement member; and a second driving circuit that drives a voltage to the second bending displacement member. Control means for controlling
The drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are different in phase from each other. The drive device described. 6. The drive according to claim 5, wherein the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are out of phase with each other by 90 degrees. apparatus. 6. The drive according to claim 5, wherein the drive voltage waveform driven by the first drive circuit and the drive voltage waveform driven by the second drive circuit are 180 degrees out of phase with each other. apparatus. A third bend including a third connecting portion that passes through the first connecting portion and is connected to the driving direction conversion member on a second imaginary line that is parallel to a direction perpendicular to the driving direction of the driven body. A displacement member;
A fourth bend including a fourth connecting portion that passes through the second connecting portion and is connected to the driving direction conversion member on a third imaginary line that is parallel to a direction perpendicular to the driving direction of the driven body. The drive device according to claim 1, further comprising a displacement member. A bending displacement of the first and second bending displacement members, comprising: a first driving circuit that drives a voltage to the first bending displacement member; and a second driving circuit that drives a voltage to the second bending displacement member. Control means for controlling
The third bending displacement member is connected to the first drive circuit and driven in the same phase as the voltage driven by the first bending displacement member,
9. The drive device according to claim 8, wherein the fourth bending displacement member is connected to a second drive circuit and driven in the same phase as a voltage driven by the second bending displacement member. . A housing capable of accommodating the first and second bending displacement members and the driving direction conversion member;
The drive device according to any one of claims 1 to 9, wherein the first and second bending displacement members are formed as part of a side wall of the casing. The first and second bending displacement members are arranged such that the first and second bending displacement directions are perpendicular to the driving direction in which the driven body is driven. The drive device according to any one of 10. The drive device according to claim 1, wherein the first and second bending displacement members include a piezoelectric material layer and a shim material. The drive device according to any one of claims 1 to 12, wherein the first and second bending displacement members include a stack of two piezoelectric material layers. As the driven body, a driving device for driving a lens barrel to which an objective lens is attached,
The dimension of the said 1st and 2nd bending displacement member in the drive direction of a to-be-driven body is 2.5 times or less of the focal distance of the said objective lens, The any one of Claims 1-13 characterized by the above-mentioned. 2. The drive device according to item 1. As above SL driven member, a driving device for driving the lens barrel objective lens is attached,
15. The dimension of the bending displacement member in a direction perpendicular to the driving direction of the driven body is not more than three times the diameter of the objective lens. Drive device. The drive device according to any one of claims 1 to 15, which drives a lens barrel to which an objective lens is attached as the driven body;
An imaging apparatus comprising: an imaging element that captures an image formed by the objective lens. An imaging apparatus comprising the imaging device according to claim 16.