JPH07168245A - Diaphragm driving mechanism - Google Patents

Abstract

PURPOSE:To provide a compact diaphragm driving mechanism without projecting a driving body in the radial direction. CONSTITUTION:The diaphragm driving mechanism is provided with a wheel with arrow-shaped spokes 5 turned against a diaphragm case 4 to change the diameter of an opening by plural diaphragm blades 3, an ultrasonic motor 1 having a laminated piezoelectric element 1c generating a high frequency vibration and a U-shaped elastic body composed of a base part 1a on which the laminated piezoelectric element 1c is fixed and beams 1b and 1b' parallelly projected from both end parts of the base part 1a, arranged in front of tame wheel 5 along its optical axis and allowing a contact part 1d to contact with the front surface of the motor 1, a holding member 6 holding the ultrasonic motor 1 and a press-contacting mechanism energizing the holding member 6 by an energizing member 7 passing through a screw 11, so that the motor 1 is pressed to contact with the wheel 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm drive mechanism, and more particularly to a diaphragm drive mechanism for driving diaphragm blades by an electro-mechanical energy conversion element.

[0002]

2. Description of the Related Art Conventionally, various diaphragm drive mechanisms have been proposed for driving diaphragm blades by an electro-mechanical energy conversion element.

[0003] As an example, for example, actual Kaihei 3-495.
In Japanese Patent Publication No. 35-35, in order to drive the diaphragm, a cylindrical ultrasonic motor that generates whirling vibration is brought into contact with the radial upper end of the arrow wheel, and the arrow motor is rotated by this ultrasonic motor to move the diaphragm blades. The one that opens and closes is described.

Further, in Japanese Patent Laid-Open No. 59-96882, there is disclosed a device for driving a diaphragm, in which an annular traveling wave motor is brought into contact with the side surface of the arrow wheel to rotate the arrow wheel to open and close the diaphragm blades. It is disclosed.

[0005]

However, in the one disclosed in Japanese Utility Model Laid-Open No. 3-49535, the ultrasonic motor for driving the diaphragm is arranged so as to project outward in the radial direction of the diaphragm driving mechanism. When the diaphragm drive mechanism is incorporated in a lens, the diameter of the lens becomes large.

Further, in the one described in JP-A-59-96882, the annular ultrasonic motor is arranged by using the entire side surface parallel to the optical axis of the diaphragm drive mechanism. , Requires a large space.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a small diaphragm drive mechanism in which a driving body does not project in the radial direction.

[0008]

In order to achieve the above-mentioned object, an aperture drive mechanism according to the present invention is provided with an arrow wheel that changes the aperture diameter of aperture blades by being rotated with respect to a fixed member, and a high frequency vibration. And an electric-mechanical energy conversion element for generating the electric-mechanical energy conversion element, and at least one rod-shaped elastic body to which the electric-mechanical energy conversion element is fixed. A driving body that is at least partially contacted with
And a press-contact mechanism for press-contacting the driving body toward the arrow wheel.

[0009]

The electro-mechanical energy conversion element generates high-frequency vibrations, the pressure contact mechanism presses the drive member toward the front surface or the rear surface of the arrow wheel, and the arrow wheel is rotated with respect to the fixed member, whereby the diaphragm blades are rotated. Change the aperture diameter of.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention, FIG. 1 is a perspective view showing an aperture drive mechanism of the first embodiment, and FIG. 2 is an extension of the aperture drive mechanism in the optical axis direction. FIG. 3 is an exploded perspective view showing the diaphragm drive mechanism, and is a plan view showing a part of the arrow wheel and the diaphragm case in cross section.

In the first embodiment, the U-shaped ultrasonic motor previously proposed by the present applicant is used as the drive source of the diaphragm drive mechanism.

This diaphragm driving mechanism rotates a diaphragm case 4, which is a fixed member, a plurality of diaphragm blades 3 which are rotatably held and housed in the diaphragm case 4, and the diaphragm blade 3. The arrow wheel 5, a U-shaped ultrasonic motor 1 that is a driving body for rotating the arrow wheel 5, and a vibration damping member 12 that prevents leakage of vibration generated in the U-shaped ultrasonic motor 1.
And a holding member 6 for holding the U-shaped ultrasonic motor 1
And a fixed frame 9 to which the holding member 6 is attached, and the holding member 6 on the flat surface portion 5c of the arrow wheel 5 opposite to the diaphragm blades 3.
The urging member 7 that constitutes a press-contact mechanism for press-contacting the U-shaped ultrasonic motor 1 via the main part is configured.

A diaphragm mechanism portion including the diaphragm blades 3, the diaphragm case 4 and the arrow wheel 5 is well known, and a support hole 3a is formed at the base end portion of each diaphragm blade 3 and the support is provided. A drive pin 3b is erected on the front surface of the arrow wheel 5 near the base end near the hole 3a.

The diaphragm case 4 has a doughnut-shaped peripheral wall having an exposure opening 4a in the center thereof, and the support holes 3a of the diaphragm blades 3 are inserted through the substrate, so that the diaphragm blades 3 are rotatable. Support pins 4b to be held are fixed at equal angular positions by the number of the respective diaphragm blades 3, and each diaphragm blade 3 is inserted into the support hole 3a in each support pin 4b so as to be on the substrate of the diaphragm case 4. It is stored in.

The drive pins 3b projecting to the front side of the stored aperture blades 3 are fitted into cam grooves 5b for driving the aperture blades of the arrow wheel 5 which will be described later.

The arrow wheel 5 is composed of a donut-shaped disc having an exposure opening 5a in the center thereof, and the exposure opening 4a of the case 4 is provided on the front side of the diaphragm case 4 for the exposure. The apertures 5a are rotatably arranged so as to coincide with each other, and cam grooves 5b for driving the diaphragm blades are formed at equal angular positions so as not to penetrate to the front side.

The diaphragm mechanism constructed as described above is driven by bringing the U-shaped ultrasonic motor 1 into contact with the arrow wheel 5.

The U-shaped ultrasonic motor 1 is composed of a base portion 1a serving as a central beam portion having a U-shape, and beam portions 1b and 1b 'which are projected in parallel from both ends of the base portion 1a. An elastic body and a laminated piezoelectric element 1c which is an electro-mechanical energy conversion element sandwiched between the beam portions 1b and 1b 'of the elastic body with an epoxy adhesive. There is.

The beam portion 1b of the U-shaped ultrasonic motor 1 is provided with a vibration isolator formed on a surface opposite to the laminated piezoelectric element 1c by a felt vibration isolator having the same shape as the same surface. The member 12 is adhered with a viscoelastic adhesive 13 such as a double-sided adhesive tape, which prevents the vibration generated in the U-shaped ultrasonic motor 1 from leaking and prevents the vibration from being extinguished. Is increasing the efficiency of.

The surface of the vibration isolating member 12 opposite to the surface to which the U-shaped ultrasonic motor 1 is adhered is adhered to the inner surface of the holding member 6 with a viscoelastic adhesive 15 such as a double-sided adhesive tape. . The holding member 6 is made of a slightly thin and thin metal plate, and is bent in a U shape so as to wrap the U-shaped ultrasonic motor 1 from the side surface. The mounting portion for fixing is formed in a wing shape so as to project to both sides. A hole for penetrating the screw 11 is formed in this mounting portion.

The fixed frame 9 is a donut-shaped disc member having a circular hole 9a for passing a photographing light beam in its central portion, and a female screw is provided at a position corresponding to a hole penetrating the screw 11 of the holding member 6. The hole 9c is threaded. Further, a substantially rectangular notch 9b is provided at the upper end portion of the fixed frame 9 in FIG. 2 so that the U-shaped ultrasonic motor 1 can directly contact the arrow wheel 5.

The holding member 6 to which the U-shaped ultrasonic motor 1 is bonded is fixed by screwing a screw 11 into the female screw hole 9c of the fixed frame 9.

Further, the beam portion 1 of the U-shaped ultrasonic motor 1
A contact portion 1d, which is formed of a wear-resistant material and has an arc shape, is provided at the tip of the arrow wheel 5 side surface of b ′ so as to project from the same surface. And this contact part 1
d is brought into contact with the arrow wheel 5 by screwing the holding member 6 to the fixed frame 9 with the screw 11.
By providing the arc-shaped contact portion 1d, even when the beam portion 1b ′ and the arrow wheel 5 are slightly deviated from each other in parallel,
The vibration of b'can be efficiently transmitted to the arrow wheel 5.

As for the mounting angle of the U-shaped ultrasonic motor 1, if the long side of the beam portion 1b 'is parallel to the tangential direction of the arrow wheel 5, vibration is efficiently transmitted to the arrow wheel 5. . Since the tip end has a larger amplitude than the base end of the beam 1b ', the contact portion 1d may rotate the arrow wheel 5 faster if it is attached to the tip of the beam 1b'.
Conversely, when it is desired to change the rotation speed of the arrow wheel 5, this can be easily done by changing the mounting position of the contact portion 1d.

A biasing member 7 made of a coil spring or the like is inserted in the screw portion of the screw 11, and the biasing member 7 is provided.
, By changing the force of tightening the screw 11,
In addition, or by changing the length of the screw 11,
The U-shaped ultrasonic motor 1 can be crimped to the arrow wheel 5 with an optimum pressing force, the efficiency of the motor is increased, and the rotation speed of the arrow wheel 5 can be improved.

As shown in FIGS. 2 and 3, the arrow wheel 5 to which the U-shaped ultrasonic motor 1 is pressure-contacted is for receiving a ball which projects rearward on the back side of the outer peripheral edge portion thereof. The protrusion 5d is formed over the entire circumference.

A step portion 4c is formed on the inner surface of the peripheral wall of the throttle case 4 at a position corresponding to the protrusion 5d, and the bearing ball 10 is interposed between the step 4c and the protrusion 5d. , The arrow wheel 5 by the pressing force of the biasing member 7
The frictional force and the rotational friction generated between the diaphragm case 4 and the diaphragm case 4 are reduced.

Further, a step portion 4d for accurately fixing the fixed frame 9 is also provided on the inner surface of the peripheral wall of the diaphragm case 4, and when the fixed frame 9 is fitted into the diaphragm case 4, the step portion 4d is fitted into the step portion 4d. It is possible to bring them into contact with each other for accurate positioning. Thereby, the contact portion 1d of the U-shaped ultrasonic motor 1
Since the frictional state between the arrow wheel 5 and the arrow wheel 5 is also kept constant, stable rotation of the arrow wheel 5 can be obtained.

Although the fixed frame 9 is fixed to the diaphragm case 4 by a press-fitting method in this embodiment, it may be fixed by screwing or the like.

Further, when the fixed frame 9 is fixed to the aperture case 4, a predetermined small gap is secured between the fixed frame 9 and the arrow wheel 5, and the arrow wheel 5 is fixed to the fixed frame 9.
It is designed to rotate without contact with and not to lose energy.

Next, the operation of the diaphragm drive mechanism of the first embodiment will be described. If a predetermined high frequency voltage is applied to the laminated piezoelectric element 1c of the U-shaped ultrasonic motor 1 from a power source (not shown), the beam portion 1 of the U-shaped ultrasonic motor 1 will be described.
b ′ vibrates at high frequency. Due to this vibration, the arrow wheel 5 that is in pressure contact with the beam portion 1b ′ rotates about the optical axis O.

When the arrow wheel 5 rotates, the driving pins 3b are engaged with the cam grooves 5b for driving the diaphragm blades, so that the plurality of diaphragm blades 3 rotate around the support pins 4b, respectively, and desired. Therefore, the aperture opening diameter can be obtained.

Further, the U-shaped ultrasonic motor 1 can change the speed at which the arrow wheel is rotated by changing the voltage applied by the high frequency power source.

According to the first embodiment as described above, since the ultrasonic motor as the drive motor is arranged on the side of the diaphragm drive mechanism which is the front surface of the arrow wheel in the optical axis direction, the motor in the radial direction is A protrusion can be eliminated, and a small diaphragm drive mechanism can be obtained, which in turn makes it possible to downsize the lens body provided with this diaphragm drive mechanism.

FIG. 4 shows a second embodiment of the present invention, and is a plan view including a partial cross section showing an essential part of the diaphragm drive mechanism. In the second embodiment, since the diaphragm mechanism shown in the first embodiment is used as it is, and the holding member and the pressing method are changed, the same reference numerals are given to the portions having the same functions. Will be omitted, and mainly different points will be described. Further, in FIG. 4, instead of showing the entire diaphragm drive mechanism, only the main parts different from the first embodiment are shown.

The shape of the U-shaped ultrasonic motor 1 shown in FIG. 4, the method of contacting the arrow wheel 5, the viscoelastic adhesive 13 on the left side of the U-shaped ultrasonic motor 1 in FIG. The fact that the elastic adhesive material 15 is laminated is similar to that of the first embodiment described above.

Next, the points changed in the second embodiment will be described. On the surface of the vibration isolator 12 opposite to the surface to which the U-shaped ultrasonic motor 1 is adhered, the viscoelastic adhesive 15
The pressing plate 23 is adhered via. This pressing plate 23
Is a plate-shaped member formed of a material such as metal or engineering plastic so as to have substantially the same size as the beam portion 1b of the U-shaped ultrasonic motor 1.
The depression 23a is provided so that the tip of the first member 1 abuts.

Then, as described above, the viscoelastic adhesive 13,
The motor unit including the U-shaped ultrasonic motor 1, the vibration isolating member 12, and the pressing plate 23, which are bonded and integrated by 15, are put in a holding member 26 formed of a thin metal plate or the like.

The holding member 26 is shaped like an elongated box so as to prevent the motor unit from being displaced in the vibration direction of the U-shaped ultrasonic motor 1, and the elongated box. The inner size of the holding member 26 is designed to be slightly larger so that a slight gap is formed when the motor unit is inserted.

A thin film made of a material having a low coefficient of friction such as Teflon is attached to the inner surface of the holding member 26 so that the motor characteristics do not deteriorate even when the motor unit comes into contact with the holding member 26. Or coated.

Then, at both ends of the holding member 26,
A mounting portion for mounting on the fixed frame 9 is provided,
It is fixed to the fixed frame 9 by screwing a set screw 24 from this mounting portion.

A screw hole is formed in the holding member 26 at a position facing the recess 23a of the pressing plate 23.

The biasing member 2 composed of a spring or the like
2 is assembled to the pressing screw 21 and the pressing screw 21
By screwing into the screw hole provided in the holding member 26, the tip end of the screwed pressing screw 21 is engaged with the recess 23a of the pressing plate 23 and positioned.
By adjusting the force with which the pressing screw 21 is fastened, the force with which the ultrasonic motor 1 is pressed against the arrow wheel 5 can be adjusted.

According to the second embodiment, the same effect as that of the first embodiment can be obtained, and the mounting portion of the holding member 26 to the fixed frame 9 can be made small. This has the advantage that the drive mechanism can be miniaturized.

FIG. 5 shows a third embodiment of the present invention. FIG. 5 is a side sectional view (A) showing a diaphragm driving mechanism of this embodiment, and (B) a front view showing which section is cut. is there. Note that the cross section of FIG.
(B) is a cross section taken along the line BB in the direction of arrow C, and the other sections are half cross sections taken along a cutting line that connects BB without detours. In the third embodiment, parts having the same functions as those of the first and second embodiments described above are designated by the same reference numerals, and the description thereof will be omitted. Only different points will be mainly described.

In the third embodiment, the bearing ball 31
Is an example in which the center of the diaphragm drive mechanism is arranged in the optical axis direction.
This is an example in which a pin is provided so as to fit with the blade presser 34.

The diaphragm drive mechanism of the present embodiment is a well-known one, although the structure is slightly different from that of the first and second embodiments as described above, and the pin 33a is provided on the blade pressing 34 side of the diaphragm blade 33.
Are planted, and the pins 33a are fitted in the cam grooves 34b provided in the blade retainer 34.

Further, on the surface of the diaphragm blade 33 on the arrow wheel 35 side,
A pin 33b is planted, and the pin 33b is fitted into a bottomed hole 35b provided in the arrow wheel 35 and not penetrated. The arrow wheel 35 is formed of a donut-shaped disc having an exposure opening 35a in the center thereof, and a V-shaped groove 35c is formed in the outer peripheral portion thereof.

The blade retainer 34 is a donut-shaped disc member having the exposure opening 4a in the center thereof, and the screw 36 is screwed into the screw hole provided in the outer peripheral portion of the diaphragm case 39 at the outer peripheral portion. They are fixed together and form the basic structure of the diaphragm drive mechanism.

In such a diaphragm drive mechanism, the U-shaped ultrasonic motor 1 is fixed to the diaphragm case 39, and the diaphragm case 39 is fixed to the fixing frame 9 of the first and second embodiments. A notch 39a having a shape combining the provided circular hole 9a and the notch 9b is provided, and a female screw hole 39c for mounting a motor is screwed. Then, the contact portion 1d of the beam portion 1b ′ of the ultrasonic motor 1 passes through the notch 39a,
The urging member 7 comes into contact with the surface of the arrow wheel 35 on the diaphragm case 39 side.
A pressing force is applied by the holding member 6 biased by.

A ball retainer 37a and a ball retainer 37b are fixed to the inner peripheral side of the aperture case 39 by screwing a screw 32 into a screw hole 39d. The diameters of the ball retainer 37a and the ball retainer 37b are fixed. A V-shaped groove is formed inside the direction.

A V-shaped groove formed by the ball retainers 37a and 37b and a V formed on the outer peripheral portion of the arrow wheel 35.
By interposing the bearing ball 31 between the U-shaped groove and the groove, the frictional force and the rotational friction due to the pressure force of the biasing member 7 of the arrow wheel 35 can be reduced. Drive energy of the ultrasonic motor 1 is applied to the arrow wheel 3
5 can be efficiently transmitted.

According to the third embodiment as described above, it has substantially the same operation and effect as those of the first and second embodiments.

FIG. 6 shows a fourth embodiment of the present invention. FIG. 6 is a sectional side view (A) showing an aperture drive mechanism of the present embodiment,
(B) It is a front view showing which cross section is cut. In the fourth embodiment, portions having the same functions as those of the above-described first to third embodiments are designated by the same reference numerals and description thereof will be omitted, and only different points will be mainly described.

The sectional view of FIG. 6A is the same as that of FIG.
(B) The BB section is seen from the direction of arrow C. This embodiment shows an example in which the ultrasonic motor and the arrow wheel are crimped by using magnetic force.

In this embodiment, the arrow wheel 45 is the third one.
The arrow wheel 35 and the blade retainer 44 of the embodiment have substantially the same basic structure as the blade retainer 34 of the third embodiment. That is, the exposure opening 45a and the bottomed hole 45b of the arrow wheel 45 are
The exposure wheel 35a and the bottomed hole 35b of the arrow wheel 35 respectively correspond to each other, and the cam groove 44b of the blade retainer 44 corresponds to the cam groove 34b of the blade retainer 34. Further, the notch 49 a of the diaphragm case 49 corresponds to the notch 3 of the diaphragm case 39.
It is almost equivalent to 9a.

In the above structure, the blade retainer 44 and the arrow wheel 45 are made of a magnetic material, and the diaphragm blade 33 and the pins 33a and 33b planted in the diaphragm blade 33 are made of a non-magnetic material. The diaphragm blade 33 side of the
When the arrow wheel 45 is magnetized so that the side of the diaphragm blade 33 of the arrow wheel 45 becomes the N pole, the arrow wheel 45 is pressed against the U-shaped ultrasonic motor 1 side by the reaction force of the magnetic force. .

At this time, the diaphragm blade 33 and the pin 3
Since 3a and 33b are made of a non-magnetic material, no pressing force is applied to the diaphragm case 49 or the blade retainer 44,
The diaphragm blades 44 can rotate smoothly.

Needless to say, the S-pole and the S-pole may be magnetized on the diaphragm blade 33 side of the blade retainer 44 and on the diaphragm blade 33 side of the arrow wheel 45.

At this time, the pressing force can be changed by changing the magnetizing force, or by attaching a thin film or coating on the magnetized surfaces of the blade retainer 44 and the arrow wheel 45.

Further, the mounting position of the ultrasonic motor 1 is
By adjusting so as to secure a slight space between the arrow wheel 45 and the diaphragm case 49, the turning friction of the arrow wheel 45 can be eliminated.

According to the fourth embodiment as described above, the operation and effect are substantially the same as those of the above-mentioned first to third embodiments, and further, as in the present embodiment, the repulsive force of magnetic force is used. In order to avoid pressure-bonding by the biasing member used in each of the above-described embodiments, the frictional force generated between the arrow wheel 45, the diaphragm blade 33, and the blade retainer 44 due to the pressure-bonding of the biasing member is increased. Can be reduced.

7A and 7B show a fifth embodiment of the present invention. FIG. 7A is a front view showing the diaphragm driving mechanism, and FIG.
It is the side view seen from the arrow C direction of (A). In the fifth embodiment, parts having the same functions as those of the above-described first to fourth embodiments are designated by the same reference numerals and description thereof will be omitted, and only different points will be mainly described.

Incidentally, in FIG. 7, the above-mentioned first to fourth
Differences from the embodiment are mainly illustrated, and detailed illustrations of other similar parts are omitted.

In this embodiment, a U-shaped ultrasonic motor is arranged in front of the diaphragm mechanism in the optical axis direction.

The arrow wheel 55 has an eave-shaped convex portion 55a formed by forming a thin plate in an arc shape in the upper front direction, and a holding member fixing portion 52 provided on a fixing frame 59 having a circular hole 59a. The V-shaped ultrasonic motor 1 is screwed by a holding member 56. The contact portion 1d of the U-shaped ultrasonic motor 1 fixed in this manner contacts the inner peripheral surface of the arc-shaped eave-shaped convex portion 55a provided on the fixed frame 59, and is engaged with the screw 51. The urging member 57 which has been stopped is pressed against the inner peripheral surface of the eave-shaped convex portion 55a.

Further, the tip of the contact portion 1d of the U-shaped ultrasonic motor 1 is arranged so that the vibration of the U-shaped ultrasonic motor 1 can be efficiently transmitted to the tip of the arrow 55. It is formed in a shape having the same radius as the radius on the inner peripheral side of the arc-shaped eave-shaped convex portion 55a projecting from the front surface of 55.

Further, the arc-shaped eave-shaped convex portion 55a protruding to the front surface of the arrow wheel 55 comes into contact with the fixed frame 59 when rotated in accordance with the rotation angle of the diaphragm blade, and the arrow wheel 55 rotates. This prevents the eaves-shaped convex portion 55a from coming off the contact portion 1d of the U-shaped ultrasonic motor 1.

According to the fifth embodiment as described above, the operation and effect are substantially the same as those of the first to fourth embodiments described above, and since the portion projecting in the optical axis direction is small, the space is further effective. It can be used for a very thin diaphragm drive mechanism.

FIG. 8 shows a sixth embodiment of the present invention, and is an exploded perspective view showing the diaphragm driving mechanism in the optical axis direction.

The sixth embodiment uses the getter type vibrator disclosed in Japanese Patent Laid-Open No. 3-128683 previously proposed by the present applicant, and the arrangement of the arrow wheel and the fixed frame will be described later. The same as that described in the publication.

The getter type vibrator 63 is a bending vibrator 64.
And a vertical oscillator 68.

The bending oscillator 64 is composed of an elastic body 64b and a piezoelectric body 64a which is an electro-mechanical energy conversion element. The piezoelectric body 64a is fixed to one side surface of the elastic body 64b with an epoxy adhesive. ing. A high-frequency driving voltage is applied to the piezoelectric body 64a of the bending oscillator 64 in the plate thickness direction to generate bending resonance. On the surface of the elastic body 64b, which serves as a node of this flexural vibration, on the side opposite to the surface on which the piezoelectric body 64a is fixed, a rectangular columnar shape of a laminated piezoelectric body is formed, and the laminated body is vertically elongated. The vibrating vertical vibrator 68 is fixed so as to vibrate vertically in the plate thickness direction of the bending vibrator 64.

Further, in the bending oscillator 64, four columnar support pins 67 extending toward the outer side in the plate width direction of the bending oscillator 64 at the nodes are provided with elastic bodies 64.
A holder mounting groove 67a is provided circumferentially in the middle of the support pin 67.

The vibrator 63 constructed in this manner has a channel-shaped cross section, and is housed in a holder 66 which is a holding member formed to cover the vibrator 63 from the side to which the piezoelectric body 64a is fixed. Is held. That is, the holder 66 is formed by bending an elastic thin plate into a U-shape, and has arcuate receiving portions 66c with one end open at positions corresponding to the support pins 67 on both hanging walls thereof. The opening portion of the receiving portion 66c is provided with a notch having a width slightly smaller than the diameter of the holder mounting groove portion 67a.

Further, in the middle of both hanging walls of the holder 66, there are provided attachment fixing portions 66a which are bent outward and extend horizontally, respectively.
Openings 66b through which the fixing screws 61 respectively pass through
Has been drilled.

The vibrator 63 is vibratably stored in the holder 66 by fitting the holder mounting groove 67a of the support pin 67 into the receiving portion 66c with respect to the holder 66. The fixing screw 61 is passed through the opening 66b of 66 through the disc spring 62 serving as a biasing member,
A screw hole 69 in which the fixing screw 61 is screwed into a fixing frame 69.
The vibrator 63 is disposed in the rectangular cutout hole 69b of the fixed frame 69 by being screwed into c.

Further, a circular hole 69a is formed in the fixed frame 69, and has substantially the same shape and size as the exposure hole 65a of the arrow wheel 65.

The other end face of the vertical oscillator 68 of the disposed oscillator 63 is pressed against the arrow wheel 65 by the urging force of the disc spring 62.

The principle of operation of the ultrasonic motor of the present embodiment thus constructed is almost the same as that described in the above-mentioned Japanese Patent Laid-Open No. 3-128683, and the phase difference between bending vibration and longitudinal vibration is different. Is adjusted to generate elliptical vibration on the end face of the vertical oscillator 68, and the arrow wheel 65 is pressed against the end face of the vertical oscillator 68 to rotate the arrow wheel 65 and rotate the diaphragm blades. The operation of the other parts is almost the same as in the above-described first to fifth embodiments.

According to the sixth embodiment, the same effect as that of the above-mentioned first to fifth embodiments can be obtained.

In each of the above embodiments, the U-shaped vibrator and the getter-shaped vibrator are used as the vibrator, but the present invention is not limited to this. The present invention can also be applied to a π-type oscillator disclosed in JP-A-2-51370 and a getter-type oscillator that operates according to the principle described in Japanese Patent Application No. 4-155214.

[0083]

As described above, according to the present invention, it is possible to provide a small diaphragm drive mechanism in which the driving body does not project in the radial direction.

[Brief description of drawings]

FIG. 1 is a perspective view showing a diaphragm driving mechanism according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the diaphragm driving mechanism of the first embodiment in an expanded state in the optical axis direction.

FIG. 3 is a plan view including a partial cross section showing the diaphragm drive mechanism of the first embodiment.

FIG. 4 is a plan view including a partial cross section showing an essential part of an aperture drive mechanism according to a second embodiment of the present invention.

5A is a side sectional view showing a diaphragm driving mechanism of a third embodiment of the present invention, and FIG. 5B is a front view thereof.

6 (A) is a side sectional view and FIG. 6 (B) is a front view showing an aperture stop driving mechanism of a fourth embodiment of the present invention.

FIG. 7A is a front view and FIG. 7B is a side view showing a diaphragm driving mechanism of a fifth embodiment of the invention.

FIG. 8 is an exploded perspective view showing a diaphragm driving mechanism of a sixth embodiment of the present invention in a state of being stretched in the optical axis direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ultrasonic motor (driving body) 1a ... Base part 1b, 1b '... Beam part 1c ... Laminated piezoelectric element (electro-mechanical energy conversion element) 1d ... Contact part 3,33 ... Aperture blade 4,39,49,59 ... diaphragm case (fixing member) 5, 35, 45, 55, 65 ... arrow wheel 6, 26, 56 ... holding member 7, 22, 57 ... biasing member 62 ... disc spring (biasing member) 63 ... getter type vibrator (Driving body) 64 ... Bending vibrator 64a ... Piezoelectric body (electrical-mechanical energy conversion element) 64b ... Elastic body 66 ... Holder (holding member) 68 ... Vertical vibrator 69 ... Fixed frame

Claims (2)

[Claims] 1. An arrow wheel that changes the aperture diameter of a diaphragm blade by being rotated with respect to a fixed member, an electro-mechanical energy conversion element that generates high-frequency vibration, and the electro-mechanical energy conversion element that are fixed to each other. A drive body, which is made of at least one rod-shaped elastic body, is arranged at the front or the rear along the optical axis direction of the arrow wheel, and is at least partially in contact with the front surface or the rear surface of the arrow wheel, and the driver is attached to the arrow wheel. A diaphragm drive mechanism, comprising: 2. The diaphragm drive mechanism according to claim 1, wherein the pressure contact mechanism uses a repulsive force of a magnetic force.