JP2007271989A - Shutter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact shutter device that can be mounted in a mobile phone and so on. <P>SOLUTION: The shutter device includes: an aperture plate in which a shutter aperture is made; a shutter blade that opens or closes the shutter aperture by receiving driving force; a rotor that drives the shutter blade by being rotated; and an ultrasonic actuator that acts on the rotor, thereby causing the rotor to rotate. The ultrasonic actuator has an oscillator that is disposed in contact with the rotor at its one end, bent on the way in contact with rotor into a corner , further extends therefrom, and is fixed to the aperture plate at the other end. The oscillator is disposed such that the shutter aperture is located on the minor angle side of the corner. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shutter device that opens and closes a shutter opening.

  2. Description of the Related Art In recent years, it has been widely practiced to incorporate a photographing device for photographing a subject in a small device such as a mobile phone. By providing a photographing device in a small device that is always carried around, it is possible to easily shoot anytime without having to carry a digital camera or a video camera. In addition, these small devices are generally equipped with a data communication function using wireless or infrared rays in advance, and the captured images are immediately taken on the spot to other mobile phones, personal computers, etc. There is also an advantage that can be sent to.

  However, since a photographing device built in a mobile phone or the like is considerably smaller than a normal digital camera, a lens, a CCD (Charge Couple Device) imaging element, a MOS (Metal Oxide Semiconductor) imaging element (hereinafter referred to as these) Are collectively referred to as “imaging device”), and the size of the shutter and the space for storing them are greatly limited. In recent years, both improvement in image quality and downsizing of the photographing apparatus have been achieved, and a small imaging element having a large number of pixels and a small lens corresponding to this have been developed. For example, only an electronic shutter that electronically adjusts the light receiving time of the image sensor is used without using an optical shutter that blocks light irradiated to the image sensor. However, in an imaging apparatus using only an electronic shutter, the light applied to the image sensor is not physically blocked, so that the light received by the image sensor leaks after the electronic shutter is turned off. As a result, there is a risk that image defects such as white streaks will occur in the captured image. For this reason, there is a strong demand to reduce image defects by mounting a small optical shutter on a photographing device built in a mobile phone or the like.

  An optical shutter is generally one that opens and closes a shutter opening by driving shutter blades using the rotation of a motor. Normally, an electromagnetic motor that rotates a rotor by a magnetic field is often used as a motor that drives the shutter blades. However, since the electromagnetic motor consumes a large amount of power and is relatively large, it is intended to be mounted in the photographing apparatus. Then, the size and weight of the entire photographing apparatus are greatly increased, and it is necessary to secure sufficient power for driving the electromagnetic motor. Therefore, it is difficult to mount an optical shutter using an electromagnetic motor on a mobile phone or the like that is required to be reduced in size and weight.

  In this regard, it has been proposed to drive an optical shutter using an actuator using piezoelectric or the like instead of an electromagnetic motor. Patent Documents 1 and 2 disclose a basic configuration of an actuator using piezoelectric. Is described.

  FIG. 1 is a schematic configuration diagram of an ultrasonic actuator 10 using piezoelectricity, and FIG. 2 is a diagram for explaining an operation principle of the ultrasonic actuator 10.

  As shown in FIG. 1, the ultrasonic actuator 10 supports a piezoelectric element 11 that vibrates when voltage is applied, an elastic vibrating body 12 that is distorted by the vibration of the piezoelectric element 11, the piezoelectric element 11, and the elastic vibrating body 12. And a pressing plate 15 for pressing the spring 14 against the elastic vibrating body 12. The supporting member 13 is configured to support the elastic vibrating body 12 toward the rotor 20.

  As shown in FIG. 2, the elastic vibrating body 12 is sandwiched between two piezoelectric elements 11a and 11b. For example, when an AC voltage having the same phase is applied to each of the piezoelectric elements 11a and 11b, the piezoelectric elements 11a and 11b. 11a and 11b expand and contract in the same direction, the elastic vibrating body 12 is deformed, and the tip of the elastic vibrating body 12 is pressed against the rotor 20, whereby the tip of the elastic driving body 12 is driven in an ellipse, and the rotor 20 is driven. It will be rotated in the direction of arrow A.

In this way, by providing the optical shutter with an ultrasonic actuator that vibrates upon application of a voltage, the optical shutter can be driven with less power than the electromagnetic motor. The noise can be reduced.
JP 2005-218179 A JP 2003-199371 A

  By the way, the distortion of the elastic vibration body 12 includes longitudinal vibration in which the elastic vibration body 12 expands and contracts, bending vibration in which the elastic vibration body 12 bends so as to wave, and coupled vibration in which the longitudinal vibration and the bending vibration are combined. Are known. In order to drive the optical shutter at high speed, it is necessary to rotate the rotor 20 at high speed by coupling and oscillating the elastic vibrating body 12. However, according to the techniques described in Patent Document 1 and Patent Document 2 described above. In order to couple and vibrate the elastic vibrator, it is necessary to apply AC voltages having different phases to each of the plurality of piezoelectric elements, which causes a problem that the voltage control becomes complicated.

  Further, in the conventional ultrasonic actuator, in addition to the support member 13 that supports the elastic vibrating body 12, a preload mechanism such as a spring 14 that presses the elastic vibrating body 12 against the rotor 20 and a pressing plate 15 is required. In particular, although the preload mechanism is a component that is not directly related to the distortion of the elastic vibrating body 12, it occupies the same space as the other portions, and the ultrasonic actuator is downsized. It has become a neck.

  From the above, in order to mount an optical shutter equipped with an ultrasonic actuator in a photographing device for a mobile phone, further miniaturization of the ultrasonic actuator, simplification of voltage control, and the like are required.

  In view of the above circumstances, an object of the present invention is to provide a small shutter device that can be mounted on a mobile phone or the like.

The shutter device of the present invention that achieves the above object includes an aperture plate in which a shutter aperture is formed,
A shutter blade that opens and closes the shutter opening in response to a driving force;
A rotor that drives the shutter blades by rotation;
An ultrasonic actuator that acts on the rotor and rotates the rotor,
The ultrasonic actuator includes a vibrator that has a corner portion that is bent at one end in contact with the rotor, extends further, and is fixed to the opening plate at the other end side. It is characterized by being deployed in a position.

  According to the shutter device of the present invention, the ultrasonic actuator is supported by the end (the other end side) fixed to the aperture plate of the vibrator, and the fixed side end (the other end side) and the corner portion. The end (one end side) in contact with the rotor is pressed against the rotor by the elasticity of the portion between them. For this reason, the preload mechanism such as the support member 13 shown in FIG. 1, the spring 14, and the pressing plate 15 is not necessary, and the ultrasonic actuator can be miniaturized. Furthermore, in the shutter device of the present invention, the ultrasonic actuator has a bent corner portion, and the shutter blade is driven in a space vacant on the inferior angle side of the corner portion. Even if the shutter is attached, the shutter device does not increase in size and can be mounted on a mobile phone or the like.

In the shutter device of the present invention, the vibrator is plate-shaped,
The ultrasonic actuator further includes a piezoelectric element that is in contact with a part of the vibrator between the one end and the corner portion, vibrates upon application of an AC voltage, and transmits the vibration to the vibrator. preferable.

  According to the shutter device of the present invention, when an AC voltage is applied to the piezoelectric element, the vibrator is distorted in a direction corresponding to the phase of the AC voltage, and the direction of a part of the distortion is converted at the corners. Directional distortions are combined and transmitted to the rotor. Therefore, the coupling vibration described above can be realized by simply applying a single-phase AC voltage to the piezoelectric element, and voltage control can be simplified.

  In the shutter device of the present invention, it is preferable that a plurality of the piezoelectric elements are provided across a portion of the vibrator between the one end and the corner portion.

  By providing a plurality of piezoelectric elements with the vibrator interposed therebetween, the enlargement of the apparatus can be suppressed, the vibrator can be greatly distorted, and the shutter blades can be driven at high speed.

  In the shutter device of the present invention, it is preferable that the vibrator is a metal plate and also serves as one electrode of each of the plurality of piezoelectric elements.

  According to the preferred shutter device of the present invention, the vibrator also serves as an electrode for applying a voltage to the piezoelectric element, so that the entire device can be reduced in size.

  In the shutter device of the present invention, it is preferable that a part of the vibrator on the one end side is formed to be narrower than a part excluding the part.

  By forming a portion of the vibrator on the side in contact with the rotor to be narrow, distortion of the vibrator is efficiently transmitted to the rotor, and the shutter blades can be reliably driven.

  According to the present invention, a shutter device can be mounted on a mobile phone or the like.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, prior to the description of the shutter device of the present invention, the ultrasonic actuator applied to the shutter device of the present invention will be described in detail.

  FIG. 3 is a schematic configuration diagram showing an example of an ultrasonic actuator applied to the shutter device of the present invention.

  As shown in FIG. 3, the ultrasonic actuator 100 includes two piezoelectric elements 110 that vibrate upon application of an alternating voltage, an electrode 111 for applying an alternating voltage to the piezoelectric element 110, and a corner 120a. A diaphragm 120 is provided that is bent in an L shape, the upper leg 121 is in contact with the rotor 100A, and the lower leg 122 is fixed. The ultrasonic actuator 100 corresponds to an example of the ultrasonic actuator referred to in the present invention. The diaphragm 120 corresponds to an example of a vibrator according to the present invention, the rotor 100A corresponds to an example of a rotor according to the present invention, and the piezoelectric element 110 corresponds to an example of a piezoelectric element according to the present invention.

  FIG. 4 is an enlarged view of the ultrasonic actuator 100, and FIG. 5 is a diagram showing the polarization direction of the piezoelectric element 110.

  In the present embodiment, the diaphragm 120 is made of stainless steel (for example, SUS304), and the piezoelectric element 110 is made of piezoelectric ceramics (for example, PZT). The materials constituting the diaphragm 120 and the piezoelectric element 110 are not limited to these.

  In the diaphragm 120, a contact portion 121a of the upper leg 121 that comes into contact with the rotor 100A is formed with a narrow width. In addition, the two piezoelectric elements 110 are disposed with the upper leg 121 of the vibration plate 120 interposed therebetween, and the vibration plate made of metal is distorted by the vibration of the piezoelectric element 110 and the two piezoelectric elements. It also serves as a counter electrode for each of the two electrodes 111 provided in the element 110. As described above, the diaphragm 120 serves as both a vibrating body and a counter electrode, whereby the ultrasonic actuator 100 can be reduced in size.

  As shown in FIG. 5, the two piezoelectric elements 110 are polarized in the thickness direction (arrow C, arrow C ′), and the two piezoelectric elements 110 have the same phase, the same size, and the same. An alternating voltage of frequency is applied.

  6 and 7 are diagrams showing directions of distortion generated in the diaphragm 120. FIG.

  When an AC voltage is applied to the two piezoelectric elements 110, the piezoelectric elements 110 are excited and distortion occurs in the upper leg 121 of the diaphragm 120. The upper leg 121 of the diaphragm 120 is pressed against the rotor 100A shown in FIG. 3 by the elasticity of the lower leg 122, and the distortion generated in the diaphragm 120 is reliably transmitted to the rotor 100A. In this way, by bending the diaphragm 120 into an L shape, a support member that supports the piezoelectric element 110 and a preload mechanism that presses the diaphragm 120 against the rotor 100A become unnecessary, thereby reducing the number of parts and suppressing manufacturing costs. In addition, the ultrasonic actuator 100 can be significantly downsized.

  In addition, the direction of a part of the distortion generated in the upper leg 121 is changed by the corner portion 120a. As a result, distortion in a plurality of directions is generated in the diaphragm 120, and the distortions in the plurality of directions are combined and transmitted to the rotor 100A. The order of the vibration mode of the diaphragm 120 shown in FIGS. 6 and 7 is an example, and can be adjusted by changing the length of the diaphragm 120.

  FIG. 8 is a graph showing the resonance frequency of the diaphragm 120.

  In FIG. 8, the horizontal axis indicates the length X of the upper leg 121 of the diaphragm 120, and the vertical axis indicates the resonance frequency of the diaphragm 120.

  Compared with the conventional ultrasonic actuator 10 shown in FIGS. 1 and 2, the ultrasonic actuator 100 loses the symmetry of the shape because the diaphragm 120 is bent in an L shape, and longitudinal vibration is not generated. When the vibration occurs, a part of the longitudinal vibration is converted into a bending vibration. Conversely, when the bending vibration occurs, a part of the bending vibration is converted into the longitudinal vibration. Thus, in the ultrasonic actuator 100, two vibrations are always mixed.

As shown in FIG. 8, in the ultrasonic actuator 100 of this embodiment, the resonance frequency of the longitudinal vibration (L-mode) and the resonance frequency of the bending vibration (B-mode) do not coincide with each other. In the region R where the resonance frequency of vibration approaches, the nearest resonance frequency f _Low when closest to the bending vibration graph on the longitudinal vibration graph and the nearest resonance frequency when closest to the longitudinal vibration graph on the bending vibration graph f _High .

For example, when an alternating voltage having the latest resonance frequency f _Low on the longitudinal vibration (L-mode) graph shown in FIG. 8 is applied to the two piezoelectric elements 110, the diaphragm 120 is mainly expanded and contracted. It is distorted to generate a longitudinal vibration (L-mode), and the longitudinal vibration is converted into a distortion in the bending direction at the corner portion 120a to generate a bending vibration (B-mode). The longitudinal vibration and the bending vibration are coupled at the front end portion 121 of the diaphragm 120, and the rotor 100A is rotated by the resultant force T in which the expansion and contraction of the diaphragm 120 is added to the expansion and contraction of the diaphragm 120 as shown in FIG.

When an alternating voltage having the latest resonance frequency f _High on the bending vibration (B-mode) graph shown in FIG. 8 is applied to the two piezoelectric elements 110, the diaphragm 120 is mainly bent in the bending direction. The bending vibration (B-mode) is distorted and the bending vibration is converted into the distortion in the expansion / contraction direction at the corner 120a to generate the longitudinal vibration (L-mode). By combining these longitudinal vibration and bending vibration at the tip 121 of the diaphragm 120, as shown in FIG. 7, the rotor 100A is rotated by the resultant force T ′ in the direction opposite to that in FIG.

  FIG. 9 is a diagram illustrating an operation principle of rotating the rotor 100A in the forward direction.

For example, when an alternating voltage having a resonance frequency f _Low is recently applied to vibrate the piezoelectric element 110, the amplitude of distortion of the diaphragm 120 gradually increases. When the bending displacement of the diaphragm 120 is maximum in the upward direction and the expansion / contraction displacement approaches 0, the contact portion 121a of the diaphragm 120 comes into contact with the rotor 100A (step S11 in FIG. 9). At this time, the expansion / contraction speed becomes maximum in the extension direction.

  Subsequently, the diaphragm 120 extends, and the contact portion 121a strikes the outer periphery of the rotor 100A, thereby giving rotational torque to the rotor 100A. As a result, the rotor 100A rotates in the arrow M direction (step S12 in FIG. 9). At this time, the expansion / contraction displacement is maximum, the bending displacement is near 0, and the downward speed is maximum.

  When the diaphragm 120 is extended to the maximum, the diaphragm 120 is displaced in a contracting direction, but a downward bending displacement is generated, and the contact portion 121a is separated from the rotor 100A. (Step S13 in FIG. 9). At this time, the expansion / contraction displacement is 0, the bending displacement is maximum in the downward direction, and the speed in the contraction direction is maximum.

  In the state where diaphragm 120 is most contracted, diaphragm 120 expands and contracts in the direction opposite to that in step S11, but contact portion 121a is away from rotor 100A, so contact portion 121a does not hinder the rotation of rotor 100A. The rotor 100A continues to rotate with inertia (step S14 in FIG. 9).

  As described above, the rotor 100A is rotated in the forward direction (the direction of the arrow M).

  FIG. 10 is a diagram illustrating an operation principle of rotating the rotor 100A in the sub direction.

Contrary to FIG. 9, when an AC voltage having a resonance frequency f _High is applied recently to vibrate the piezoelectric element 110, when the expansion / contraction displacement of the vibration plate 120 is maximum in the extension direction, The contact portion 121a does not contact the rotor 100A (step S21 in FIG. 10). At this time, the displacement in the expansion / contraction direction is maximum, the bending displacement is near 0, and the upward speed is maximum.

  Subsequently, the diaphragm 120 contracts, and the contact portion 121a rubs around the outer periphery of the rotor 100A, thereby giving rotational torque to the rotor 100A. As a result, the rotor 100A rotates in the direction of the arrow M ′ (step S22 in FIG. 10). At this time, the expansion / contraction displacement is 0, the bending displacement is 0, and the speed in the contraction direction is maximum.

  When the displacement in the bending direction is maximum in the upward direction, the expansion / contraction displacement is minimum, and the contact portion 121a is separated from the rotor 100A. (Step S23 in FIG. 10). At this time, the expansion / contraction displacement is minimum, and the bending displacement is maximum in the upward direction.

  When the displacement in the bending direction is maximized in the downward direction, the expansion / contraction displacement approaches the maximum. However, since the contact portion 121a is separated from the rotor 100A, the contact portion 121a does not hinder the rotation of the rotor 100A, and the rotor 100A is inertial. The rotation continues (step S24 in FIG. 10).

  As described above, the rotor 100A is rotated in the sub direction (arrow M ′ direction).

As described above, according to the ultrasonic actuator 100, both the bending vibration and the longitudinal vibration are applied to the diaphragm 120 by simply applying the same AC voltage (magnitude, phase, frequency) to each of the two piezoelectric elements 110. Therefore, the rotor 100A can be rotated at high speed with simple voltage control. Further, the rotation direction of the rotor 100A can be changed by switching the frequency of the AC voltage applied to the piezoelectric element 110 to the two nearest resonance frequencies f _High and f _Low , and the rotor 100A can be efficiently rotated.

  Subsequently, an embodiment of the shutter device of the present invention provided with the ultrasonic actuator as described above will be described.

  FIG. 11 is an external perspective view of an embodiment of the shutter device of the present invention.

  The shutter device 200 is a small optical shutter that is mounted on a photographing device for a mobile phone, and a shutter blade, an ultrasonic actuator that drives the shutter blade, and the like are provided inside the case 210. The shutter device 200 has a shutter opening 200a penetrating from the front surface to the back surface, and a CCD (not shown), a MOS, or the like of the photographing device is attached so as to close the shutter opening 200a from the back surface side. The shutter opening 200a corresponds to an example of the shutter opening according to the present invention.

  FIG. 12 is a schematic configuration diagram of the shutter device 200.

  As shown in FIG. 12, the shutter device 200 is rotated inside the case 210 by an L-shaped ultrasonic actuator 310 having the same configuration as the ultrasonic actuator 100 shown in FIG. 3 and the ultrasonic actuator 310. A rotor 320 is provided. The case 210 is provided with a support frame 211 that surrounds the opening 210a, and the ultrasonic actuator 310 is disposed so that the support frame 211 is positioned inside the L-shape.

  FIG. 13 is an exploded perspective view of the shutter device 200, and FIG. 14 is a side sectional view of the shutter device 200. In FIGS. 13 and 14, it is assumed that the subject light L is incident from the left side of the figure, and the left side of the figure is referred to as the front and the right side of the figure is referred to as the rear.

  The shutter device 200 includes a blade pressing plate 214, a shutter blade 330, a blade base plate 213, a case 210, a rotor 320, an ultrasonic actuator 310, and a lid 212 in order from the front where the subject light L is incident. Yes. The shutter blade 330 is an example of the shutter blade according to the present invention, and the combination of the blade base plate 213 and the blade presser plate 214 corresponds to an example of the opening plate according to the present invention.

  The rotor 320 is provided with a drive pin 321 for driving the shutter blade 330. The case 210 has an opening 210a through which the subject light L passes, a drive groove 210b into which the drive pin 321 of the rotor 320 is fitted, A center boss 210c that is the rotation center of the shutter blade 330 and a fixing boss 210d for fixing the blade base plate 213 and the blade presser plate 214 are provided.

  First, the lower leg 312 of the ultrasonic actuator 310 is fixed to the case 210, and the rotor 320 is pivotally supported between the case 210 and the lid 212 so that the upper leg 311 of the ultrasonic actuator 310 contacts the rotor 320. .

  Subsequently, the fixing boss 210d of the case 210 is fitted into the fixing holes 213d and 214d formed in the blade base plate 213 and the blade presser plate 214, respectively, so that the blade base plate 213 and the blade presser plate 214 are fixed to the case 210. Is done. As a result, the shutter opening 200a of the rear portion 202 is formed by the openings 214a, 213a, 210a, and 212a formed in the blade pressing plate 214, the blade base plate 213, the case 210, and the lid 212, respectively.

  Further, the center boss 210c of the case 210 is fitted into the center holes 213c, 330c, and 214c formed in the blade base plate 213, the shutter blade 330, and the blade presser plate 214, respectively, and the drive pin 321 of the rotor 320 is connected to the case 210c and the blade. The driving grooves 210b, 213b, and 214b formed in the base plate 213 and the blade pressing plate 214, respectively, and the engagement groove 330b formed in the shutter blade 330 are fitted. The shutter blade 330 is supported by a gap between the blade base plate 213 and the blade pressing plate 214 so as to be rotatable around the central boss 210c.

  The shutter opening 200a is opened and closed as follows. Here, it is assumed that the shutter blade 330 moves in the direction to open the shutter opening 200a when the rotor 320 rotates in the sub direction.

  For example, when the display of a through image is instructed by the user of the mobile phone, an AC voltage is applied to the piezoelectric element 110 (see FIG. 3) of the ultrasonic actuator 310 by the CPU of the mobile phone, and the rotor 320 rotates in the sub direction. Is done. As the rotor 320 rotates, the drive pin 321 fixed to the rotor 320 is rotated along the drive grooves 210b, 213b, and 214b, and engages with the engagement groove 330d of the shutter blade 330 to move the shutter blade 330 downward. . As a result, the shutter blade 330 is avoided in a position (open position) that does not interfere with the shutter opening 200a.

  The subject light L passes through openings 214a, 213a, 210a, and 212a formed in the blade pressing plate 214, the blade base plate 213, the case 210, and the lid 212, respectively, and a CCD (not shown) provided on the back surface of the lid 212. Imaged on top.

  In the CCD, charges corresponding to the amount of received light are stored, and the stored charges are converted into analog subject signals at predetermined timings. The subject signal is roughly read to generate through-image data representing a low-resolution through-image, and is sent to the CPU of the mobile phone so that the through-image is displayed on the display screen of the mobile phone.

  Thus, since the through image is generated with the shutter opening 200a being opened, the CCD receives light while the stored charge is converted into the subject signal. Leaked light may cause image defects such as white streaks. For this reason, when the captured image is actually acquired, the shutter opening 200 a is closed by the shutter blade 330.

  When the photographing switch is pressed by the user of the cellular phone and the photographing of the subject is instructed, an AC voltage is applied to the piezoelectric element 110 (see FIG. 3) of the ultrasonic actuator 310 by the cellular phone CPU, and the rotor 320 The driving pin 321 fixed to the rotor 320 is rotated in the forward direction opposite to that when the shutter is opened, and moves the shutter blade 330 upward. As a result, the shutter blade 330 is moved to a position (a light shielding position) that closes the shutter opening 200a of the rear portion 202. In the present embodiment, the rotation angle of the rotor 320 is restricted by the drive pins 321, the case 210 c, the blade base plate 213, and the drive grooves 210 b, 213 b, and 214 b formed in the blade retainer plate 214. Is moved inside the L-shape of the ultrasonic actuator 310 between the avoidance position and the light shielding position described above.

  In the CCD, the charge corresponding to the amount of received light is stored between when the photographing switch is pressed and the shutter opening 200a is closed, and the stored charge is converted into a subject signal. The converted subject signal is finely read to generate captured image data representing a high-resolution captured image, and the generated captured image data is sent to the CPU of the mobile phone.

  As described above, when the captured image is generated, the shutter opening 200a is blocked by the shutter blade 330, so that light leaks to the CCD and an image defect occurs in the captured image. Can do.

  In the present embodiment, a miniaturized ultrasonic actuator 310 is applied, and as shown in FIG. 12, a shutter opening 200a is provided in an empty space inside the L-shape of the ultrasonic actuator 310. Therefore, the enlargement of the entire shutter device 200 is reduced. Furthermore, since the ultrasonic actuator 310 is power saving compared to a conventional electromagnetic motor and voltage control is simpler than that of a conventional ultrasonic actuator, the shutter device 200 can be applied to a small device such as a mobile phone. Can be installed.

  Here, the example provided with the ultrasonic actuator using the piezoelectric is described above, but the ultrasonic actuator according to the present invention can rotate the rotor by using a vibrator having a bent shape. If there is, an ultrasonic actuator using a polymer or the like may be used.

  In the above description, an example in which an ultrasonic actuator having two piezoelectric elements is provided has been described. However, the ultrasonic actuator in the present invention may be an ultrasonic actuator having three or more piezoelectric elements. Alternatively, it may be an ultrasonic actuator provided with one piezoelectric element.

  In the above description, the ultrasonic actuator bent in an L shape has been described. However, the ultrasonic actuator according to the present invention may have two or more corners.

  In the above description, the ultrasonic actuator provided with the metal diaphragm that also serves as the electrode of the piezoelectric element has been described. However, the ultrasonic actuator according to the present invention uses, for example, a plastic vibrator to vibrate the vibration. Aside from the child, an electrode for applying a voltage to the piezoelectric element may be provided.

  In the above description, an example in which the shutter device of the present invention is mounted on a mobile phone has been described. However, the shutter device of the present invention may be mounted on a small digital camera or the like.

It is a schematic block diagram of the ultrasonic actuator using a piezoelectric material. It is a figure for demonstrating the principle of operation of an ultrasonic actuator. It is a schematic block diagram which shows an example of the ultrasonic actuator applied to the shutter apparatus of this invention. FIG. 4 is an enlarged view of the ultrasonic actuator shown in FIG. 3. It is a figure which shows the polarization direction of a piezoelectric element. It is a figure which shows the direction of the distortion which generate | occur | produces in a diaphragm. It is a figure which shows the direction of the distortion which generate | occur | produces in a diaphragm. It is a graph which shows the resonant frequency of a diaphragm. It is a figure which shows the principle of operation which rotates a rotor to a normal direction. It is a figure which shows the operation | movement principle which rotates a rotor to a subdirection. It is an external appearance perspective view of one Embodiment of the shutter apparatus of this invention. It is a schematic block diagram of a shutter apparatus. It is a disassembled perspective view of a shutter apparatus. It is sectional drawing of the side surface of a shutter apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100,310 Ultrasonic actuator 11,110 Piezoelectric element 12 Elastic vibration body 13 Support member 14 Spring 16 Pushing plate 20,100A, 320 Rotor 111 Electrode 120 Diaphragm 120a Corner | angular part 121 Upper leg 122 Lower leg 200 Shutter apparatus 200a Shutter opening 210 Case 211 Support section 212 Lid 213 Blade base plate 214 Blade retainer plate 330 Shutter blade

Claims (5)

An aperture plate in which a shutter aperture is formed;
A shutter blade that opens and closes the shutter opening in response to a driving force;
A rotor for driving the shutter blades by rotation;
An ultrasonic actuator that acts on the rotor to rotate the rotor,
The ultrasonic actuator includes a vibrator having a corner portion with one end contacting the rotor and bent in the middle, and further extending and having the other end side fixed to the aperture plate, A shutter device provided in a posture in which a shutter opening is located. The vibrator is plate-shaped,
The ultrasonic actuator further includes a piezoelectric element that contacts a part of the vibrator between the one end and the corner portion, vibrates upon application of an alternating voltage, and transmits the vibration to the vibrator. The shutter device according to claim 1.   The shutter device according to claim 2, wherein a plurality of the piezoelectric elements are provided across a part of the vibrator between the one end and the corner portion.   The shutter device according to claim 3, wherein the vibrator is a metal plate and serves as one electrode of each of the plurality of piezoelectric elements.   The shutter device according to claim 1, wherein a part of the one end side of the vibrator is formed to be narrower than a part excluding the part.

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