JP5188061B2 - Vibration wave drive - Google Patents

Description

  The present invention relates to a vibration wave driving device that generates a predetermined vibration wave in a vibration member and obtains a driving force by a frictional force with a contacting member, and a lens barrel including the vibration wave driving device.

  As a conventional vibration wave driving device of this type, for example, there is a linear driving device shown in FIG. 4 (Patent Document 1).

  As shown in FIG. 4, the linear drive device includes a vibration member 101 that generates a vibration wave and a longitudinal direction (X direction) relative to the vibration member 101 by transmitting the vibration wave of the vibration member 101. And a long linear slider 102 that is linearly slid and driven.

  In FIG. 4, the linear slider 102 moves in the X direction with respect to the vibrating member 101. On the contrary, the vibrating member 101 moves in the X direction with respect to the linear slider 102. It is also possible to do. Then, the drive target member is attached to the moving member of the vibration member 101 and the linear slider 102.

  Further, a linear slider 102 formed of a magnet has been proposed (Patent Document 2). In this proposal, the vibration member 101 and the linear slider 102 attract each other, the tips 104a and 104b of the projections 103a and 103b of the vibration member 101 come into contact with the linear slider 102, and the driving force in the X direction is obtained by the friction force. I am doing so.

  However, since the contact between the vibration member 101 and the linear slider 102 is a contact at two points, a line or a plane, the position fluctuates in the same direction unless the movement in the Y direction in FIG. 4 is regulated. Further, when the contact portion between the vibration member 101 and the linear slider 102 is deformed due to wear, the position in the Z direction also changes.

  Therefore, when trying to control precise linear drive using this type of linear drive device, the movement of the drive target member is guided separately from the contact portion between the vibration member 101 and the linear slider 102, and the drive target member A guide member for stabilizing the posture is required.

  However, when such a guide member is provided, it is difficult to arrange the guide direction and posture of the drive target member by the guide member and the contact portion between the vibration member 101 and the linear slider 102 in parallel with high accuracy. Become.

  Therefore, conventionally, a linear drive device provided with a compliance mechanism for relaxing and absorbing this parallelism error has been proposed.

  As shown in FIG. 5, the linear drive device has a vibration member 203 that generates a vibration wave, and the vibration wave of the vibration member 203 is transmitted along the longitudinal direction relative to the vibration member 203. And a long linear slider 202 that is linearly driven to slide.

The vibration member 203 is provided with an elastic body that is a component of the vibration member 203, and a piezoelectric ceramic (not shown) that generates vibration waves is provided on the back surface of the elastic body. The vibration member 203 is a compliance mechanism for reducing and absorbing parallelism errors between the guide direction and posture of the drive target member by the guide member 205 and the contact portion between the vibration member 203 and the linear slider 202. A leaf spring 204 is provided.
Japanese Patent Laid-Open No. 2004-304877 JP 2005-354787 A

  In the above conventional technique, the compliance mechanism for relaxing and absorbing the parallelism error between the guide direction and posture of the drive target member by the guide member and the contact portion between the vibration member 203 and the linear slider 202 occupies a large space. Therefore, the size of the apparatus is increased.

  In Patent Documents 1 and 2, contact and separation are repeated at a vibration cycle at a contact portion between the vibration member 101 and the linear slider 102. At the time of contact, since the tips 104a and 104b of the projections 103a and 103b of the vibration member 101 come into contact with one surface of the long linear slider 102, the linear slider 102 receives the vibration force only from one side.

  Accordingly, the linear slider 102 may generate a bending vibration and generate a sound, or a contact / separation operation with the vibration member 101 may be disturbed, resulting in a decrease in driving performance. For this reason, conventionally, in order to increase the rigidity of the linear slider 102, a thick member or a damping material has been attached, which hinders downsizing of the apparatus.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vibration wave driving device and a lens barrel that can be downsized without using a compliance mechanism.

To achieve the above object, the vibration wave driving apparatus of the present invention, through a vibration member for generating a vibration wave length and long member vibration wave that is transmitted in the vibration member, the carrier to the vibration member attached And a guide member that guides the carrier along a moving direction, wherein the vibration member and the drive target member are in relation to the long member. moving, bending rigidity and torsional rigidity of the elongate member, characterized in that not less than the flexural rigidity and torsional rigidity of the guide member.

  According to the present invention, the bending rigidity and torsional rigidity of the long member are made smaller than the bending rigidity and torsional rigidity of the guide member. Thus, even without a compliance mechanism, the parallelism error between the guide direction and posture of the driven object by the guide member and the contact portion between the vibration member and the long member can be reduced and absorbed. Miniaturization can be realized.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view for explaining a linear drive device which is an example of an embodiment of the present invention, and FIG. 2 is a diagram showing a state in which a vibrating member and a linear slide of the linear drive device shown in FIG. .

  As shown in FIG. 1, a linear drive device (vibration wave drive device) that is an example of an embodiment of the present invention has a vibration member 1 that generates a vibration wave and a length to which the vibration wave of the vibration member 1 is transmitted. And a thin plate-like linear slider (long member) 6.

  The vibrating member 1 is provided with an elastic body 2 such as metal at a portion facing the linear slider 6 side. Two protrusions 3 are provided on the elastic body 2 so as to be separated from each other in the longitudinal direction of the linear slider 6, and the tip of each protrusion 3 contacts the linear slider 6 (see FIG. 2). Further, an electro-mechanical energy conversion element 5 such as a piezoelectric ceramic that generates a vibration wave is provided on the back side of the elastic body 2.

  An AC voltage is applied to the electromechanical energy conversion element 5 from the flexible printed circuit board 7, and the flexible printed circuit board 7 is connected to a drive control circuit (not shown). By transmitting a vibration wave from the protrusion 3 of the vibration member 1 to the linear slider 6, the vibration member 1 is linearly driven to slide relative to the linear slider 6 along the longitudinal direction of the linear slider 6. The In this embodiment, a drive target member (not shown) is attached to the vibration member 1, and the drive target member is guided along the moving direction by a guide member (not shown).

  Here, in this embodiment, a total of two vibrating members 1 are arranged on each side of the linear slider 6 in the thickness direction. The two vibration members 1 have the same vibration mode, vibration frequency, and vibration phase, and are pressed against the linear slider 6 from both sides by a spring (not shown). At the time of such pressure contact, the protrusions 3 of the two vibrating members 1 are arranged to face each other at the same position on both sides of the linear slider 6.

  Further, the linear slider 6 is set so that the bending rigidity and the torsional rigidity are smaller than the bending rigidity and the torsional rigidity of the guide member, and both ends thereof are fixed to a fixing member (not shown). Further, the linear slider 6 is fixed to a fixing member (not shown) at both ends thereof in a state where the linear slider 6 is extended with an appropriate tension.

  As the linear slider 6, for example, a metal tape such as stainless steel, a metal thin plate, or a resin tape such as polyimide can be used. However, the linear slider 6 is not particularly limited, and may be a wire shape or a thin rod shape. Good.

  As described above, in this embodiment, the bending rigidity and torsional rigidity of the linear slider 6 are made smaller than the bending rigidity and torsional rigidity of the guide member. As a result, even if the parallelism between the guide direction and posture of the member to be driven by the guide member and the contact portion 4 between the vibration member 1 and the linear slider 6 is somewhat poor, the parallelism error may be caused by bending of the linear slider 6 or Can be relaxed and absorbed by twisting. As a result, the compliance mechanism can be dispensed with and the apparatus can be downsized.

  Further, since the two vibration members 1 having the same vibration mode, vibration frequency, and vibration phase are brought into contact at the same position on both sides in the thickness direction of the linear slider 6, bending vibration stress is applied to the linear slider 6. Can not be. As a result, the rigidity of the linear slider 6 can be further reduced. As a result, there is no need to use a thick member or affixing a damping material in order to increase the rigidity of the linear slider 6. Can be achieved.

  FIG. 3 shows an example in which a linear drive device which is an example of an embodiment of the present invention is applied to a lens barrel.

  A lens barrel provided in an imaging apparatus such as a camera or a video camera needs to drive and control an optical lens along the optical axis like focus and zoom. Cameras and video cameras are also required to be portable, so it is desirable to reduce the size of the lens barrel.

  Therefore, by applying a linear drive device, which is an example of an embodiment of the present invention, to a lens barrel, the lens barrel and thus the imaging device can be downsized.

In FIG. 3, the two vibrating members 1 are arranged symmetrically so as to sandwich the linear slider 6 in the same manner as in the above embodiment. The two vibration members 1, an optical lens (driven member) 10 is attached via a carrier 9. The optical axis of the optical lens 10 is disposed substantially parallel to the linear slider 6, and the carrier 9 is integrated with the optical lens 10 by two guide bars (guide members) 8 a and 8 b disposed substantially parallel to the optical lens 10. Are guided in the direction of the optical axis.

  The configurations of the vibration member, the long member, the drive target member, the guide member, and the like of the present invention are not limited to those illustrated in the above embodiment, and can be changed as appropriate without departing from the gist of the present invention. It is.

  For example, in the above-described embodiment, the case where the vibrating member 1 moves along the longitudinal direction of the linear slider 6 with respect to the linear slider 6 is illustrated. However, the linear slider 6 moves along the longitudinal direction with respect to the vibrating member 1. The present invention may also be applied to a case where the user moves.

  In this case, a drive target member is attached to the linear slider 6, and the drive target member is guided by the guide member.

It is a perspective view for demonstrating the linear drive device which is an example of embodiment of this invention. It is a figure which shows the state which the vibration member and linear slide of the linear drive device shown in FIG. 1 contacted. It is a perspective view which shows the example which applied the linear drive device which is an example of embodiment of this invention to the lens-barrel. It is a perspective view for demonstrating the conventional linear drive device. It is a perspective view for demonstrating the other conventional linear drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibrating member 2 Elastic body 3 Protrusion 4 Contact part 5 Electromechanical energy conversion element 6 Linear slider (long member)
7 Flexible printed circuit boards 8a, 8b Guide bar (guide member)
9 Carrier 10 Optical lens (drive target member)

Claims (4)

A vibration member for generating a vibration wave length and long member vibration wave that is transmitted in the vibration member, along the movement direction and the driven member is attached via a carrier to the vibration member, the carrier guide A vibration wave driving device comprising:
The vibration member and the drive target member move relative to the long member,
Vibration wave driving apparatus flexural rigidity and torsional rigidity of the elongate member, characterized in that not less than the flexural rigidity and torsional rigidity of the guide member.   2. The vibration wave drive device according to claim 1, wherein a plurality of the vibration members are arranged around the long member, and a plurality of vibration members have the same vibration mode, vibration frequency, and vibration phase. . 3. The vibration wave driving device according to claim 1 , wherein the elongate member is one of a metal tape, a metal thin plate, and a resin tape . A lens barrel including a vibration wave driving device having an optical lens as a driving target member,
A lens barrel using the vibration wave drive device according to claim 1 as the vibration wave drive device.

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