JPH0888986A - Driving apparatus and camera - Google Patents

Abstract

PURPOSE: To provide a driving apparatus, which can accelerate the starting speed of a driven body and can accelerate the driving speed itself. CONSTITUTION: A driven body 6 is driven in one direction by the energizing force of an energizing means. An ultrasonic motor charges the driven body 6 against the energizing force of the energizing means. Clutch means 9, 10 and 6c connect and disconnect the output of a rotor 12b of the ultrasonic motor to and from the driven body. These parts are provided. The clutch means link the rotor 12b to the driven body 6 by the forward rotation of the rotor 12b, which is the charging direction of the driven body 6, and release the linking with the driven body 6 by the reverse rotation of the rotor 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for controlling the movement of a driven body which performs a predetermined operation by a charged spring force by an ultrasonic motor, and a shutter or a movable body using the drive device as a drive source. The present invention relates to a camera that drives a mirror or the like.

[0002]

2. Description of the Related Art In an ultrasonic motor, a rotor is pressed against a drive surface of an elastic body made of metal or the like that constitutes a vibrator by a pressing means, and the rotor is rubbed by a traveling wave formed in the elastic body. The driving wave is formed by applying an AC voltage having a phase difference of 90 ° to a two-phase piezoelectric element forming a vibrator and synthesizing two-phase standing waves excited in the elastic body. To be done.

When no AC voltage is applied to both of the two-phase piezoelectric elements, the rotor is held unrotatable with respect to the vibrator by the pressure applied by the pressurizing means. Therefore, even if a rotational force is applied to the side of the drive body connected to the rotor, the stop torque of the ultrasonic motor prevents the drive body from rotating.

Further, the two-phase standing wave formed on the oscillator forms a traveling wave that causes the surface particles on the driving surface to make an elliptic motion when the phase difference of 90 ° is present. When the two are in the same phase or when only one piezoelectric element is driven to excite only one-phase standing wave, simple vibrations are only excited on the driving surface of the elastic body. In this case, the rotor comes into contact with the peak of simple vibration excited on the drive surface, and the stoppage of the driven body in the charged state due to the change of the stop torque can be released.

As a driving device utilizing the function of such an ultrasonic motor, Japanese Patent Laid-Open No. 6-194717 has been proposed by the present applicant. This is because when the driven body is caused to perform a predetermined operation by the spring biasing force, the spring is charged by the ultrasonic motor and is held at the drive preparation position by the stop torque of the ultrasonic motor. This is performed by the stop torque release control that excites only the standing wave in the oscillator, and the holding torque is canceled and the driven body is driven by the charged spring force.

[0006]

However, in the above-mentioned conventional example, when the stop torque is released and the driven body is driven by the spring force, the driven body and the rotor of the ultrasonic motor form a gear reduction mechanism or the like. There is the following problem because the rotor is directly connected through the rotor and the rotor rotates together with the driven body.

(1) Since the rotor of the ultrasonic motor having a large inertia is added to the inertia of the driven body, the driven body rises slowly.

(2) Viscous friction exists between the rotor of the ultrasonic motor and the vibrator in proportion to the speed, and the speed of the driven body can be sufficiently increased even if the spring force of the charging spring is increased. I can't.

A first object of the present invention is to provide a driving device which can increase the rising speed of a driven body and also the driving speed itself.

A second object of the present invention is to provide a driving device capable of arbitrarily setting the driving speed of a driven body.

A third object of the present invention is to provide a camera which can drive a shutter, a movable mirror and the like by using the driving device which achieves the above first and second objects.

[0012]

Means and Actions for Solving the Problems First of the Invention
According to a first aspect of the present invention, there is provided a driven body that is driven in one direction by the urging force of the urging means.
An ultrasonic motor for charging the driven body against the urging force of the urging means, and a clutch means for connecting and disconnecting the rotor output of the ultrasonic motor with respect to the driven body. ,
The clutch means connects the rotor with the driven body by forward rotation of the rotor, which is the charging direction of the driven body, and releases the connection with the driven body by reverse rotation of the rotor. .

In this configuration, while effectively utilizing the stop torque of the ultrasonic motor, the clutch means is connected and disconnected by controlling the rotational direction of the rotor of the ultrasonic motor, and the charging of the ultrasonic motor is performed during charging. At the rotor output, when the driven body is in operation, the connection with the rotor is released to improve the rising speed of the driven body, and further the speed of the driven body itself.

Further, as described in claim 2, claim 1
In the above, the clutch means includes a rotating member having an engaging claw that engages with the driven body, a clutch spring for biasing the rotating member toward the driven body, and a forward rotation of the rotor of the ultrasonic motor. And a helical gear that moves the rotating member toward the driven body and moves the rotating member in a direction away from the driven body by reversing the rotor.

With this construction, the clutch means can be mechanically constructed, and the forward and reverse rotation of the ultrasonic motor can be effectively utilized.

Further, as described in claim 3, in claim 2, the ratio of the number of teeth of the helical gear of the clutch means to the number of claws of the engaging claws (the number of teeth / the number of claws) is an integer. By doing so, the disengagement timing of the clutch is made to be the same regardless of the engagement position between the engagement claw of the clutch means and the driven body.

A second object of the present invention and a structure to be realized are, as described in claim 4, in claim 1, 2 or 3, the control means for driving and controlling the ultrasonic motor is a driven body. Is in a charged state, it has a stop torque release mode in which only a standing wave is excited in the vibrator that constitutes the ultrasonic motor.

With this structure, when the stop torque is released, the rotor of the ultrasonic motor rotates integrally with the driven body with a friction torque controlled by the frequency of the standing wave or the like. The moving speed can be controlled to any low speed.

According to a fifth aspect of the present invention, the driving device according to any one of the first, second, third and fourth aspects is used as a front curtain of a focal plane shutter. In the camera as the drive source of each of the rear curtains, the driven bodies of the respective drive devices are the front curtain and the rear curtain, and the shutter is charged by the forward rotation of the ultrasonic motor to drive the ultrasonic motor. The feature is that the release operation is performed in reverse.

With this configuration, the rising speed of the front curtain and the rear curtain can be increased, the shutter speed can be controlled with high accuracy, and the shutter speed itself can be increased.

Further, as described in claim 6, claim 5
In the above, the stop torque canceling mode is configured to operate when the shutter speed is slower than a certain value, so that it is possible to mitigate the effect of camera shake caused by a traveling shock of the shutter curtain at low speed seconds.

According to a seventh aspect of the present invention, the drive device according to any one of claims 1, 2, 3 and 4 is used as a drive mechanism for a movable mirror. In the camera, the driven body of the driving device is a movable mirror, the movable mirror is charged by forward rotation of the ultrasonic motor, and the movable mirror is flipped up by reverse rotation of the ultrasonic motor. To do.

With this configuration, the speed at the start of the flip-up operation of the movable mirror can be increased, and the flip-up speed of the movable mirror itself can be increased.

Further, as described in claim 8, in claim 7, the stop torque canceling mode is operated to provide a movable mirror low speed mode in which the jumping speed of the movable mirror is reduced. It is possible to reduce the vibration generated at the time of flipping up and shorten the time required for stationary stabilization.

[0025]

【Example】

(First Embodiment) FIGS. 1 to 4 are views showing a focal plane shutter to which the present invention is applied. FIG. 1 shows the most characteristic feature, FIG. 2 is a front view, and FIG. 3 is a side sectional view. FIG. 4 is a diagram showing a blade system.

First, in the shutter curtain structure, as shown in FIG. 4, the front curtain group 3 is opened and closed by a well-known parallel link formed of front curtain arms 3a and 3b. A drive hole 3a ₁ is formed in the front curtain arm 3a. Also, trailing curtain group 4
Is driven by the trailing blade arms 4a and 4b similarly to the leading blade group 3, and a driving hole 4a ₁ is formed in the trailing blade arm 4a.

Reference numeral 1 is a shutter base plate, and an exposure window 1a is provided at the substantially center thereof. Reference numeral 2 is a cover base plate 2 attached so as to keep a constant distance from the shutter base plate 1.
And has an exposure window (not shown) corresponding to the exposure window 1a. Between the shutter base plate 1 and the cover plate 2,
A front curtain group 3 and a rear curtain group 4 are provided, and a partition plate 5 for partitioning the front curtain group 3 and the rear curtain group 4 is provided. An exposure window is also formed in the partition plate 5 at substantially the center (not shown).

Reference numeral 6 denotes the first support pin 1 planted in the main plate 1.
an axially supported by the front curtain drive lever c, insert the drive pin 6a of the tip driving hole 3a ₁ of the front curtain arm 3a, to drive the leading blade group 3. Reference numeral 7 denotes a front curtain drive spring provided between the drive lever 6 and the ratchet 8, which is hooked on a spring hooking portion 6b of the front curtain drive lever 6 and the other end is hooked on the ratchet 8 to move the drive lever 6 to a clock. Bias in the direction.
The front curtain drive lever 6 is locked by a ratchet pawl (not shown) of the ratchet 8, and the curtain speed is adjusted by adjusting the rotational position of the ratchet 8. A first-curtain clutch plate 9 is provided coaxially between the lever 6 and the ground body 1 on the first support pin 1c that pivotally supports the first-curtain drive lever 6, and a left-handed helical gear is formed on the first-curtain clutch plate 9. The front curtain drive lever 6
Clutch claws 9a are formed on the surface facing to.

Then, the clutch plate 9 is connected to the front curtain drive lever 6
Front curtain clutch spring 1 which is a compression spring for pressing against
0 is mounted between the base plate 1 and the clutch plate 9. The front curtain clutch plate 9 moves along the axial direction of the first support pin 1c. For the front curtain drive lever 6,
An engaging portion 6c is formed opposite to the front curtain clutch plate 9 into which the clutch pawl 9a of the clutch plate 9 enters. The clutch plate 9 and the drive lever 6 form a one-way clutch. FIG. 5 is a perspective view showing this relationship. Clutch pawl 9
Four a are provided at equal intervals.

A screw 11 prevents the ratchet 8 from coming off from the first support pin 1c.

Reference numeral 12 is a well-known front curtain drive ultrasonic motor, which comprises a vibrator 12a and a rotor 12b mounting portion 12c, and an output gear 12b ₁ having a right-handed helical gear is fixed to the rotor 12b. Output gear 12b ₁
Is decelerated due to the difference in the number of gear teeth of the front curtain plate 9. The rear curtain side has the same structure as the front curtain side, and the drive pin 13
a rear blade drive lever 13 having a and a spring hook portion 13b,
Ratchet pawl 8, trailing blade drive spring 14, clutch pawl 15a
And a rear curtain clutch plate 1 having a left-handed helical gear
5, there is a rear curtain clutch spring 16. The rear-curtain drive ultrasonic motor 17 includes a vibrator 17a, a rotor 17b, and a mounting portion 17c, and the rotor 17b has a right-handed helical gear.

Next, a signal system of the focal plane shutter of this embodiment will be shown. In FIG. 2, 18 is a front-curtain charge completion contact piece that detects the completion of charging of the front curtain, 19 is a front-curtain travel completion contact piece that detects the completion of traveling of the front curtain, and 20 is a rear curtain that detects completion of charging of the rear curtain. The charging contact piece 21 is a trailing blade travel completion contact piece for detecting completion of traveling of the rear curtain. 2
Reference numeral 2 is a stopper rubber that absorbs impact when the front curtain drive lever 6 and the rear curtain drive lever 13 collide with the shutter base plate 1.

FIG. 6 is a block diagram showing the electrical construction for driving the ultrasonic motor.

The structure of the ultrasonic motor used in this embodiment will be described below.
The bar-shaped vibrator 203a and the vibrator 203a
The rotor 203b, which is in pressure contact with one end surface that forms the drive surface of the vibrating elastic body that constitutes the above, through a pressure means (not shown), is integrally formed with a member that constitutes the oscillator, and the oscillator is fixed to the shutter base plate. It is configured by a mounting portion 203c for holding.

The vibrator 203a is formed by sandwiching and fixing two-phase piezoelectric elements arranged with a positional phase difference of 90 ° between vibrating elastic bodies.
A control signal from the USM driving device 202 controlled by 1 is applied. The USM driving device 202 is D /
The rotor is configured by an A converter, a VCO (voltage-frequency converter), a phase shifter, an amplifier, and the like, and the phase of the frequency voltage applied to the driving piezoelectric element is changed by the ring counter that constitutes the phase shifter. The rotation direction of 203b is controlled.

A characteristic of the ultrasonic motor is that the rotor 203b is frictionally held by the vibrator 203a under the pressure of the pressure applying means when the drive signal is not applied, and the rotor 203b.
The rotational force generated in the driven body that is connected to the driven member via a transmission mechanism such as a gear is held by the frictional force between the rotor 203b and the vibrator 203a. In this embodiment, the shutter charge force is held. ing.

Further, for driving, when a frequency voltage having a phase of 90 ° is applied to the two-phase driving piezoelectric element, each standing wave excited in the vibrator by two control signals is applied to the vibrator. Of the rotor 2 that comes into pressure contact with the driving surface due to the elliptical motion formed on the surface particles of the driving surface of the vibrator
03b is friction driven.

On the other hand, when the control signals applied to the two-phase piezoelectric elements have the same phase, only the bending vibration is simultaneously generated in the vibrator 203a, and the above-mentioned elliptic motion forming a traveling wave is generated in the surface particles of the driving surface. It is not formed, only the standing wave is excited. Here, the rotor 2 with respect to the vibrator 203a
The friction stopping force of 03b is stronger as the contact area between the two is larger, and is weaker as the contact area is smaller. Therefore, when a standing wave is formed on the driving surface of the vibrator 203a, the contact area between the two changes, and when the standing wave is the resonance frequency, the standing wave has a steep waveform. The contact area is the smallest, and the friction stopping force is also the smallest. Even if the control signals are not in phase, the friction stopping force can be adjusted by applying a control signal to only one of the driving piezoelectric elements and using a standing wave whose frequency is controlled.

In this embodiment, the fact that the friction stopping force can be adjusted is utilized to control the rotation of the clutch plate 9, and the friction torque and the resistance torque which is the friction stopping force of the rotor 203b at that time are controlled. The relationship with the signal frequency is shown in FIG.

In FIG. 7, some friction is included in the vicinity of the resonance frequency f _n , but it is minimal. Note that this friction is static, and the friction force tends to become greater than this as the speed increases.

The operation of the shutter thus configured will be described.

FIG. 2 shows a charge completed state. In this state, the leading blade driving lever 6 and the trailing blade driving lever 13
Are biased clockwise by drive springs 7 and 14, respectively, but are held at the charge completion position by the stop torque of the ultrasonic motor.

From this point, in the case of traveling for exposure, first, the front curtain charging ultrasonic motor 12 is provided with two 90 ° phase-shifted vibrations to rotate the rotor 12b clockwise. Then, the front curtain clutch plate 9 starts to rotate counterclockwise by the gear. Since the leading blade clutch plate 9 is pushed upward by the thrust force of the helical gear and the clutch spring 10, the leading blade driving lever 6 and the leading blade clutch plate 9 are connected to rotate the leading blade driving lever 6 counterclockwise. For a certain period of time, drive in a direction different from the exposure running direction like this,
The drive pin 6a is the drive pin 6 provided on the shutter base plate 1.
The process is performed until it comes into contact with the escape hole 1b of the movement trajectory of a. This is to stabilize the start position of the shutter curtain. After the contact, 2 to the ultrasonic motor 12 for the front curtain charging
When the two oscillating waves are changed from 90 ° out of phase to −90 °, the ultrasonic motor 12 reversely rotates and the front curtain clutch plate 9
Start rotating clockwise. Here, the drive speeds of the front curtain drive lever 6 and the front curtain clutch plate 9 are shown in FIG.

Since the front curtain clutch plate 9 only receives the inertia of the rotor of the ultrasonic motor and the inertia of the front curtain clutch plate 9 which is light, the start-up is fast. But,
The maximum rotation speed of the ultrasonic motor is 1000 rpm to 2000
Since it is low at rpm, after reaching the maximum number of rotations, it becomes a constant velocity motion, and the characteristics shown by a in FIG. 8 are obtained. On the other hand, the leading-curtain drive lever 6 drives the leading-curtain group 3 having a large inertia, so that the leading-blade drive lever 6 rises slowly.

However, thereafter, the driving spring 7 accelerates more and more, so that the characteristic becomes as shown by b in FIG.
Therefore, at the initial driving speed, the front curtain clutch plate 9 is fast and is overtaken by the front curtain drive lever 6 on the way.

FIG. 9 shows the relationship between the drive lever and the clutch plate during the exposure drive. When the front curtain clutch plate 9 is rotated clockwise, the inclined portion 9a ₁ of the clutch pawl 9a and the front curtain drive lever 6 that fits in the inclined portion 9a _1. The abutment of the slanted portion 6c ₁ of the engaging portion 6c and the thrust force of the helical gear cause the front curtain clutch plate 9
Is pushed to the left in the figure against the front curtain clutch spring 10. When the ultrasonic motor is further driven, the pawl engagement of the clutch is completely released as shown in FIG. Therefore, the front curtain drive lever 6 is driven clockwise by the force of the drive spring 7 to perform exposure. That is, the front curtain clutch plate 9
The clutch pawl 9 before it is overtaken by the front curtain drive lever 6.
The engaging portion 6c between the a and the front curtain drive lever 6 is disengaged so as not to interfere with the traveling of the front curtain drive lever 6.

The ultrasonic motor 12 is connected to the front curtain completion contact piece 1
9 is turned on, and when the front curtain traveling completion contact piece 19 detects completion of traveling, the front curtain driving ultrasonic motor 12
Is stopped. Then, since the rotor 12b is held at the stop position by the stop torque of the front curtain drive ultrasonic motor 12, the front curtain clutch plate 9 is held by the helical gears while being held to the left side as shown in FIG.

Since the operation of the front curtain on the rear curtain side is the same as that on the rear front curtain side at the shutter speed, the description thereof will be omitted.

When the trailing curtain travels and the exposure is completed, the trailing curtain running completion contact piece 21 is turned on, and the trailing curtain driving ultrasonic motor 17 is driven.
Is stopped and the state shown in FIG. 11 is reached.

Then, the charging operation starts. When the trailing curtain traveling completion signal is detected, the leading curtain driving ultrasonic motor 12 is rotated counterclockwise from the state shown in FIG. Then Fig. 9
As shown in FIG. 12, the leading-curtain clutch plate 9 is pressed against the leading-curtain drive lever 6 by the thrust force of the leading-curtain clutch spring 10 and the helical gear, and as the leading-curtain clutch plate 9 rotates, as shown in FIG.
, The engaging portion 9a ₂ of the clutch claw 9a and the engaging portion 6c of the leading blade driving lever 6 are engaged with each other, and the leading blade driving lever 6
Rotates counterclockwise in FIG. 11 and starts the charging operation.

For a while, the leading blade drive lever 6 rotates counterclockwise, and when the leading blade charging completion contact piece 21 is turned on,
The front curtain drive ultrasonic motor 12 is stopped. The front curtain is held at the charging completion position by the stop torque of the ultrasonic motor.

Next, the charging operation of the trailing curtain is started, but since the operation is exactly the same as the charging of the leading curtain side, the description thereof is omitted here.

When the trailing-curtain charge completion signal is detected, the trailing-curtain driving ultrasonic motor 17 is stopped, and the state returns to the state shown in FIG.

The positional relationship between the clutch pawls 9a of the front curtain plate 9 and the gear teeth is shown in FIG. The focal plane shutter is required to have high controllability in order to stably output high speed time such as 1/4000 seconds and 1/8000 seconds.

Strictly speaking, since the gear causes torque fluctuations depending on the tooth phase, it does not rotate at a uniform speed in a strict sense. , The gear teeth and the clutch claw 9a have the same phase angle, and the clutch break timing is the same regardless of which engagement portion 6c of the front curtain drive lever 6 is engaged, which improves controllability. ing. The same applies to the trailing curtain side.

Next, the driving of the shutter in the case of a low speed second will be described. In the case of a low speed second, the shutter accuracy can be stabilized even if the curtain speed is not necessarily high. Rather, the shutter speed is preferably slow because camera shake occurs due to the shock of the shutter curtain running at low speeds.

The slowing of the curtain speed can be achieved by generating a standing wave in the oscillator of the ultrasonic motor as described with reference to FIG.

The resistance torque can be adjusted by setting the frequency of the standing wave to the resonance frequency f _n or f ₁ . Then, the rotor of the ultrasonic motor stopped due to the stop torque starts to rotate due to the spring force of the spring that moves the shutter curtain. At this time, since the thrust force of the helical gear acts in the direction in which the clutch is engaged, the curtain speed can be controlled by the frequency of the standing wave generated in the vibrator of the ultrasonic motor. Since the shutter curtain is driven by this method only when the curtain speed is slowed, the conventional problem does not matter.

When the photographer selects a shutter time slower than a fixed value, or when the camera sets the shutter time slower than a fixed value by the photometric value, first, in order to stabilize the start position, Apply two 90 ° phase-shifted vibrations to the curtain drive ultrasonic motor 12 to rotate the rotor 12b.
Rotate clockwise. Then, the clutch is engaged and the front-curtain drive lever 6 is driven counterclockwise to bring the drive pin 6a into contact with one end of the escape hole 1b. Then, the phase of the two vibrations is changed from 90 ° to 0, or a control signal is applied only to one of the driving piezoelectric elements to generate a standing wave. At this time, the frequency is set to f _n or f ₁ in FIG.

The spring force of the front curtain drive spring 7 is the ultrasonic motor 1
It becomes larger than the resistance torque of 2, and the front curtain drive lever 6 is rotated clockwise by the spring force. The clutch plate 9
It is connected to the front-curtain drive lever 6 by the clutch spring 10, and the shape of the clutch pawl 9a causes the front-curtain clutch plate 9 to rotate together with the front-curtain drive lever 6 in the clockwise direction. The front-curtain clutch plate 9 is connected to the front-curtain charging ultrasonic motor 12 by a helical gear, and rotates the rotor 12b counterclockwise. Vibrator 12a and rotor 12b
Has the above-mentioned resistance torque, and therefore acts to suppress the curtain speed. At this time, the thrust force of the helical gear acts in the direction in which the clutch is engaged, and the shape of the clutch pawl 9a causes
Since the front curtain clutch spring 10 also has a spring force, the clutch does not break.

The operation of generating a standing wave to the vibrator 12a of the front curtain charging ultrasonic motor 12 is continued until the front curtain traveling completion contact piece 19 is turned on.

Since the same operations are performed on the rear curtain side and the front curtain side after the shutter time has elapsed, the description thereof will be omitted. The trailing-curtain traveling completion contact piece is turned on, the feeding of the standing wave to the trailing-curtain charging ultrasonic motor 17 is stopped, and the state shown in FIG. 11 is obtained. The charging is started from here, but since the charging operation is the same as the operation at the time of the normal shutter speed described above, the description thereof will be omitted.

FIG. 13 is a block diagram showing a control system of a camera which can effectively implement this embodiment. Reference numeral 100 denotes a control means, which is a known CPU 101, ROM 102, RAM 10
It consists of 3 mag. The control means 100 includes a photometric switch 10 which is turned on by the first stroke of a release button (not shown).
4. The signal from the release switch 105 which is turned on by the second stroke of the release button is input. By turning on the front curtain charge completion contact piece 18, the front curtain travel completion contact piece 19, the rear curtain charge completion contact piece 20, and the rear curtain travel completion contact piece 21,
Front curtain charge completion signal 106 and front curtain travel completion signal 1 respectively
07, a rear curtain charge completion signal 108, and a rear curtain travel completion signal 109 are generated and input to the control means 100.

A film feed signal 110 is also input. The photometric circuit 111 sends operation timing information from the CPU 101 and transfers its output to the CPU 101. The motor drivers 112 and 113 are the mirror drive motor 1
14 and the film feeding motor 115 are provided with a bridge circuit capable of switching between forward and reverse energization drive and switching to an electric brake state forming a short circuit.

Front curtain ultrasonic motor (USM) drive unit 11
6 and trailing curtain ultrasonic motor (USM) driving device 117
Are known D / A converters, VCOs,
A front curtain drive ultrasonic motor 12 including a phase shifter, an amplifier, etc.
Then, the rear curtain drive ultrasonic motor 17 is driven in the forward and reverse directions to generate a standing wave.

Further, by popping up the strobe, the strobe light emission signal 118 generated is input to the CPU 101, and when the camera user does not select a slower curtain speed due to the intention of photographing, the low curtain operated externally. The signal from the speed canceling means 119 enters the CPU 101.

The operation of the camera thus configured is shown in FIG.
It will be described based on the flowchart of FIG.

In step (hereinafter abbreviated as S) -1,
When the photometric switch 104 is turned on (S-2) while the power switch (not shown) is turned on, a wake-up operation (S-3) is performed, and a DC / DC converter (not shown) is operated to perform various circuits. To the operating state.

Next, the photometry circuit 111 is operated to determine the shutter speed and aperture (S-4). Here, the shutter speed and aperture may be determined by the user and input to the camera. When the release switch is turned on (S-5),
At (S-6), it is determined whether the shutter speed is higher or lower than a predetermined value.

If the speed is higher than the predetermined value, the TvHi flag is set (S-7), and if the speed is lower than the predetermined value, the TvLo flag is set (S-8).

At (S-10), the mirror drive motor 1
Power supply to 14 is started, and mirror up is started. When the mirror up is completed (S-10), the mirror drive motor is stopped and the shutter is driven for exposure (S-1).
1). Details of driving the shutter will be described later. When the exposure is completed, the mirror drive motor 114 is energized to start the mirror down (S-12). When the mirror down is completed (S-13), the mirror drive motor 114 is stopped and the film feeding motor 115 is energized. , Film winding is started (S-14). When film winding is completed (S
-15), The film feeding motor 115 is stopped. Then, the shutter charge starts.

The CPU 101 normally rotates the front-curtain driving ultrasonic motor 12 through the front-curtain ultrasonic motor driving device 116 to connect the clutch and perform spring charging of the front curtain (S-16). When the front curtain charge completion signal 106 is input to the CPU 101 (S-17), the CPU 101 stops the front curtain drive ultrasonic motor 12 (S-18). Next, the CPU 101 normally rotates the rear-curtain driving ultrasonic motor 17 via the rear-curtain ultrasonic motor driving device 117 to connect the clutch and perform spring charging of the rear curtain (S-1).
9). When the rear charge completion signal 108 is input to the CPU 101 (S-20), the rear curtain drive ultrasonic motor 17 is stopped (S-21), and the camera sequence is ended (S-).
22).

The shutter driving in (S-11) will be described in detail with reference to the flowchart of FIG.

First, before traveling for exposure, two 90 ° phase-shifted vibrations are applied to the front curtain charging ultrasonic motor 12 via the front curtain ultrasonic motor driving device 116 to reverse the rotation (#
-1) At this time, the front-curtain clutch plate 9 is connected to rotate the front-curtain drive lever 6 counterclockwise, and at the same time, the shutter timer and the front-curtain regulation timer are started (#-
2). The shutter timer is a timer for determining the shutter time, and the front-curtain regulation timer reverses the front-curtain charging ultrasonic motor 12 so that the drive pin 6a of the front-curtain drive lever 6 contacts the escape hole 1b of the shutter main plate. This is a timer for contacting and regulating the start position and stabilizing it. Here, it is determined whether the shutter time (Tv), which is set to 2 _ms , is higher or lower than a fixed value (# -3), and the high speed is set. If so, it is determined whether the shutter time (# -4) or the front curtain regulation timer (# -5) ends first, and if the front curtain regulation timer expires first, the front curtain drive ultrasonic motor When the phase difference between the two vibrations is set to −90 ° and rotated in the forward direction (# -6), the leading blade clutch plate 9 is separated from the leading blade driving lever 6 and the leading blade group 3 drives the driving spring 7. Drive with only power.

The CPU determines which of the shutter time elapsed (# -7) and the front curtain running completion signal 107 (# -8) comes first.
When the first curtain traveling completion signal 107 comes first, the CPU 101 stops the vibration generation in the front curtain driving ultrasonic motor 12 and stops the rotation (# -9). (#
In -10), waiting for the shutter time to elapse, the rear curtain drive ultrasonic motor 17 is caused to generate two 90 ° phase-shifted vibrations through the rear curtain ultrasonic motor drive device 117,
The rear curtain drive ultrasonic motor 17 is rotated in the reverse direction (# -11), and at the same time, the rear curtain control timer is started (# -12). This is to regulate the start position of the rear curtain group 4.

When the trailing curtain regulation timer expires, (# -1
3), the vibration applied to the rear curtain drive ultrasonic motor 17 is 90 °
Then, the phase difference is set to −90 ° and the normal rotation is performed (# -14).
Then, the trailing blade clutch plate 15 and the trailing blade driving lever 13 are separated from each other in the initial stage of driving, and the trailing blade group 4 travels only by the force of the driving spring 14. When the trailing-curtain running completion signal 109 comes at (# -15), the CPU 101 stops the trailing-curtain driving ultrasonic motor (#-
16) and proceed to (S-11).

On the other hand, if the shutter time elapses earlier than the elapse of the front curtain regulation timer in (# -4), (#
-17), the CPU 101 controls the rear curtain ultrasonic motor drive unit 117 to regulate the start position of the rear curtain group 4.
The vibration having two 90 ° phase differences is generated and reversed (# -17), and at the same time, the trailing curtain regulation timer is started (# -18). Wait for the front curtain regulation timer to elapse (# -19), and then set the front curtain drive ultrasonic motor 12
The phase difference between the two vibrations is set to −90 ° and the normal rotation is performed (# -20). In (# -21), wait for the trailing curtain regulation timer to elapse, and then change the phase difference from 90 ° to -90 ° as with the leading curtain.
Then, the rear curtain drive ultrasonic motor 17 is normally rotated (# -2
2). Then, the rear curtain clutch plate 15 and the rear curtain drive lever 13
Are separated in the initial stage of driving, and the trailing curtain group 4 travels only by the spring force. When the front curtain traveling completion signal 107 is input to the CPU 101 (# -23), the front curtain drive ultrasonic motor 12 is stopped (# -24). Next, at (# -25), the trailing curtain running completion signal 1
When 09 enters the CPU 101, the rear curtain drive ultrasonic motor 1
7 is stopped (# -26). Then, the process proceeds to (S-11). If the shutter time has elapsed before the front curtain travel completion signal 107 in (# -7), the process proceeds to (# -27), and the rear-curtain drive ultrasonic motor 17 is operated as described above.
At the same time as reversing, the rear curtain regulation timer is started (# -28). After the elapse of the trailing blade regulation timer, the trailing blade driving ultrasonic motor 17 is normally rotated to disengage the clutch (# -30). The front curtain running completion signal 107 is the CPU 10.
When it is input to 1 (# -31), the front curtain drive ultrasonic motor 12 is stopped (# -32). Next, the trailing curtain running completion signal 1
09 (# -33), the rear curtain drive ultrasonic motor 17
To stop.

On the other hand, if it is determined in (# -3) that the shutter speed is slower than a certain value, the curtain speed is made slower than normal to prevent camera shake, so (# -35).
Go to. In (# -35), the flash emission signal 118 is CP
When U101 is input, the shutter speed is raised at the time when the shutter is fully open, so suppression of the curtain speed is canceled, and (#-
Go to 4). It should be noted that if the camera user cancels the low curtain speed by an external operation for reasons such as the intention of shooting and wanting to stop the movement of a fast-moving subject (# -36), (#-
Go to 4). If neither flash emission nor low curtain speed cancellation occurs, the process proceeds to (# -37), and when the front curtain regulation timer elapses, the CPU 101 changes the phase difference between the two vibrations of the front curtain driving ultrasonic motor 12 from 90 ° to 0. Alternatively, the standing wave is generated by stopping the vibration drive of one of them (# -38). By setting this standing wave to an arbitrary frequency, an arbitrary resistance torque is obtained as described in the description of FIG. 7, and an arbitrary curtain speed slower than the normal curtain speed can be obtained.
If the resistance torque is smaller than the spring force of the drive spring 7,
The front curtain group 3 starts exposure traveling by the spring force.

At this time, the thrust force of the helical gear acts in the direction of connecting the front curtain clutch plate 9 and the front curtain drive lever 6,
In addition, since the front curtain clutch spring 10 has a spring force and is connected by the engaging portion 9a ₁ of the clutch pawl 9a, the clutch is not separated. When the front curtain group 3 travels and the front curtain travel completion signal 107 is input to the CPU 101 (# -39), the standing wave generation of the front curtain drive ultrasonic motor 12 is stopped (# -4).
0), wait for the shutter time to elapse (# -41), and first rotate the rear-curtain drive ultrasonic motor 17 in the reverse direction in order to stabilize the start position (# -42), as in the front curtain side.
At the same time, start with the trailing curtain regulation timer (# -43), wait for the trailing curtain regulation timer to pass (# -44), set the phase of the two vibrations to 0, or stop one of the two curtains. Generate a standing wave in the drive ultrasonic motor 17 (#-
45). Then, the trailing curtain group 4 starts traveling due to the spring force of the drive spring 14. At this time, the helical gear works in the direction of pressing the trailing-clutch clutch plate 15 and the leading-curtain driving lever 13,
In addition, there is a spring force of the trailing blade clutch spring 16, and the trailing blade clutch spring 16 does not separate due to the shape of the clutch pawl 16a. Further, since the resistance torque can be arbitrarily changed by an arbitrary frequency, an arbitrary curtain speed can be obtained. It waits for the trailing-curtain running completion signal 109 to enter (# -46), and stops the standing wave of the trailing-curtain driving ultrasonic motor 17 (# -47). For slow curtain speeds (# -35 to #
-46), although it is configured such that there is a full opening time, slits may be formed by the front curtain and the rear curtain. When the shutter drive is completed, the process proceeds to (S-11).

(Second Embodiment) FIGS. 16 and 17 show a second embodiment. Similar to the first embodiment, it is applied to a focal plane shutter, but the front and rear curtain ultrasonic motors 12 and 17 and the clutch plates 9 and 15 are connected to each other by worm gears 12b ₁ and 17b ₁ and worms instead of a helical gear. Since the clutch plates 9 and 15 are integrally formed with the worm wheel and the clutch pawls, the same effects as those of the first embodiment can be obtained.

In this embodiment, the ultrasonic motor cannot be driven by the standing wave generation. However, if a drive-drive irreversible lead angle peculiar to the worm gear is set, the rotor of the ultrasonic motor of the first embodiment is changed. Vibration compared to the one held at the charging completed position only by the friction of the
This has the effect of significantly improving safety performance against accidents where the shutter curtain travels inadvertently due to impact.

(Third Embodiment) FIGS. 18 to 21 show an embodiment in which the present invention is applied to a mirror driving mechanism of a single-lens reflex camera.

18 and 19, reference numeral 300 denotes a mirror that guides an optical path to a finder optical system (not shown), and 301 is a mirror receiving plate that supports the mirror 300, which is rotatable about a hinge axis P and is a sector gear portion. It has 301a.
A tension spring 302 that urges the mirror receiving plate 301 in the upward direction is hooked on the sector gear portion 301a. 303
Is a mirror 45 ° dowel, and is a stopper for holding the mirror 300 at an inclination angle of 45 °. 304 is the mirror 3
This is a cushioning member that absorbs the shock when 00 is up. 30
Reference numeral 5 denotes a mirror-up completion detection switch for detecting completion of mirror-up, and reference numeral 306 denotes a mirror-down completion detection switch for detecting completion of mirror-down.

The mirror box wall surface 307 has an ultrasonic motor 308 of the same type as that of the first embodiment fixed to the mirror box wall surface 307.
Reference numeral 08 is a vibrator 308a, a rotor 308b, and a mounting portion 308.
consists c, the helical gear 308b ₁ of the left twist is formed 1 body specifically to rotor 308b.

A clutch plate 309 has a clutch pawl 309a for transmitting power only in a clockwise direction by a one-way clutch mechanism, and an output gear 30 of the ultrasonic motor 308.
There is a right-handed helical screw gear that meshes with 8b ₁ .
It is axially supported by a shaft 307a fixed to the mirror box wall surface 307, is urged downward in the figure by a clutch spring 310, and is pressed against a relay gear 311 having an engaging portion 311a that meshes with a clutch pawl 309a. Relay gear 311
Are axially supported by the shaft 307a and are prevented from coming off by screws 312. The relay gear 311 is provided in the sector gear portion 301a.
Mesh with.

18 and 19 show the mirror-down state, in which the tension spring 302 urges the mirror 300 in the up direction, and the shape of the clutch claw 309a and the engaging portion 311a of the relay gear 311 which meshes with it. It is completely locked by the spring force of the clutch spring 310, and is held in the down position by the stop torque of the ultrasonic motor 308. The reason why the spring is applied in the mirror up direction is to minimize the release time lag,
The spring is charged when the mirror is down and the spring force is used when the mirror is up.

From this state, in order to guide the light flux of the taking lens system to the film, the vibrator 308 of the ultrasonic motor 308 is used.
Two vibrations having a phase difference of 90 ° are generated in a. Then, the rotor 308b starts rotating clockwise, and the meshing of the gears rotates the clutch plate 309 counterclockwise. When the clutch plate 309 rotates counterclockwise,
The inclined portion of the clutch pawl 309a comes out of the locking portion 311a, and the thrust force of the helical gear causes the clutch plate 30 to move.
19 moves upward in FIG. 19 against the clutch spring 310, and the clutch plate 309 and the relay gear 311 are disengaged from each other in the initial stage of driving the mirror, and the state shown in FIG. 20 is obtained. Then, the spring force of the tension spring 302 causes the mirror receiving plate 30 to move.
1 goes up, turns on the mirror-up completion detecting means 305, and enters the state of FIG. After that, in order to completely perform mirror up, the ultrasonic motor 308 is stopped after a lapse of a predetermined time and the film is exposed by a shutter device (not shown).

Next, the mirror down operation is started. From the state shown in FIG. 20, the transducer 308a of the ultrasonic motor 308 is set to -90.
Two vibrations with a phase difference of ° are generated.

Then, the rotor 308b starts to rotate counterclockwise, and the clutch plate 309 is rotated clockwise due to the meshing of the gears, and the thrust force of the helical gear and the spring force of the clutch spring 310 cause the clutch to be connected and locked. The gear 311 is rotated clockwise, and the tension spring 302 is charged while the mirror 300 is moved down by the sector gear 301a.

When the sector gear 301a turns on the mirror-down completion detecting switch 306, the ultrasonic motor 308 is stopped after a lapse of a predetermined time in order to complete the down operation. At this time, the mirror receiving plate 301 contacts the mirror 45 ° dowel, the mirror 300 is kept at 45 °, and is held in the down position by the stop torque of the ultrasonic motor 308, which is larger than the spring force of the tension spring 302. .

The above-described mirror-up operation emphasizes that the release time lag is reduced, but the release time lag is slow for a slow-moving subject or landscape.
Even if it takes a little longer, it does not affect the image, but rather camera shake due to the impact when the mirror is raised at high speed often affects the image. Therefore, in addition to the normal mirror-up, it is desirable that the mirror-up can be driven at a slower speed than the normal time as a measure against camera shake. In this embodiment, a standing wave is generated in the ultrasonic motor 308 as described with reference to FIG. 7, and the mirror driving speed can be suppressed by the frequency.

A standing wave is generated in the ultrasonic motor 308 from the mirror-down state shown in FIGS. 18 and 19, and the resistance torque is made smaller than the tension spring force to start the mirror-up. At this time, the relay gear 311 and the clutch plate 30
9 is in a state of being connected by the thrust force of the hasba and the spring force of the clutch spring 310, and the mirror up speed can be controlled by changing the frequency of the standing wave to the ultrasonic motor 308. Sector gear section 301a
When the mirror-up completion detecting means 305 is turned on, the standing wave to the ultrasonic motor 308 is stopped after a lapse of a predetermined time in order to complete the mirror-up. After the shutter (not shown) is driven, the mirror is down. The mirror-down operation is the same as the normal mirror-down operation described above, and therefore its explanation is omitted.

FIG. 22 is a block diagram showing a control system of a camera to which the mirror driving mechanism of this embodiment is applied. 500
Is a control means, which is a known CPU 501, ROM 502, R
It consists of AM503. A signal from the low-speed mirror setting means 504 operated by the photographer to prevent camera shake is input to the control means 500. Further, signals of a release switch 505 which is turned on by the first stroke of a release button (not shown) and a release switch 506 which is turned on by the second stroke of the release button are input.

When the mirror-up completion detecting means 305 and the mirror-down completion detecting means 306 are turned on, a mirror-up signal 507 and a mirror-down signal 508 are generated and input to the control means 500. Further control means 50
A film advance signal 509 is also input to 0. The photometric circuit 510 sends information on operation timing from the control means 500 and transfers the output thereof to the control means 500.

The motor drivers 511 and 512 include a shutter charge motor 513 and a film feeding motor 514.
Has a bridge circuit capable of switching between forward and reverse energization drive and switching to an electric brake state that constitutes a short circuit. The shutter device 515 is energized by the magnets of the front and rear curtains, and OF
The CPU 501 sends the F timing signal. The ultrasonic motor driving device 516 is a known D / A converter, V
It is composed of a CO phase shifter, an amplifier and the like, and drives the ultrasonic motor 308 in forward and reverse directions and generates standing waves.

The operation of the camera thus configured is shown in FIG.
It will be described based on the flowchart of FIG.

In step (hereinafter abbreviated as S) -1,
When a power source (not shown) is turned on, a wakeup operation (S
-2) is performed, and a DC / DC converter (not shown) is operated to put various circuits into an operating state.

At (S-3), when the photographer selects the low speed mirror by the low speed mirror setting means 504, VmL
o flag is set (S-4), otherwise VmHi
A flag is set (S-5). When the photometry switch 505 is turned on (S-6), the photometry circuit 510 is operated (S).
-7), shutter speed and aperture are determined.

When the release switch is turned on (S-
8) The mirror speed is determined (S-9), and if the mirror speed flag is VmHi, the process proceeds to (S-10), in which the ultrasonic motor 308 is driven by the ultrasonic motor driving device 516 to drive the mirror. To rotate normally (S-10).

Then, the clutch is disengaged and the mirror up operation is started. When the mirror-up signal 507 is input to the CPU 501 (S-11), a timer of 5 ms is started (S- to ensure that the mirror-up is completed).
12), when the timer is completed (S-13), CPU
501 stops the ultrasonic motor 308 (S-1).
4).

On the other hand, at (S-9), the mirror speed flag is set to V.
If it is the MLo flag, the process proceeds to (S-15), and the CPU 5
01 causes the ultrasonic motor 308 to generate a standing wave via the ultrasonic motor driving device 516 (S-15). Then, the resistance torque of the ultrasonic motor 308 decreases, and the spring force of the tension spring 302 starts the mirror-up. When the mirror-up signal 507 is input (S-16), a 5 ms timer is started to complete mirror-up (S-17), and when the timer is completed (S-18),
The standing wave of the ultrasonic motor 308 is stopped (S-1
9). Next, the CPU 501 controls the magnet of the shutter to drive the shutter (S-20). Then, the ultrasonic motor 308 is reversely driven through the ultrasonic motor driving device 516 in order to perform the mirror down (S-2).
1), the relay gear 311 and the clutch plate 309 are connected,
Mirror down starts. Mirror down completion signal 50
When 8 is entered (S-22), a 5 ms timer is started to complete mirror down (S-23), and when the timer is completed (S-24), the ultrasonic motor 308
Is stopped (S-25). At this time, the ultrasonic motor 308
The stop torque is greater than the force exerted by the tension spring 302, thus holding the mirror in the down position.

Next, the CPU 501 controls the motor driver 51.
The shutter charge motor 513 is driven via 1 to start the shutter charge (S-26).

When the shutter charge is completed (S-2
7) Then, the film feeding motor 514 is driven through the motor driver 512 to start winding (S-28), and when film winding is completed (S-29), the camera sequence is completed (S-30).

Although the above embodiments have been described with respect to the focal plane shutter and the mirror driving device of the single-lens reflex camera, they can be applied to all those that reciprocate.

[0105]

According to the invention described in claim 1, while effectively utilizing the stop torque of the ultrasonic motor, the clutch means is connected and disconnected by controlling the rotation direction of the rotor of the ultrasonic motor. At the time of charging, the rotor output of the ultrasonic motor is used, and at the time of operation of the driven body, the connection with the rotor is released to improve the rising speed of the driven body, and also the speed of the driven body itself. Can be achieved.

According to the second aspect of the invention, the clutch means can be simplified with a mechanical structure, and the forward and reverse rotation of the ultrasonic motor can be effectively utilized.

According to the third aspect of the present invention, the disengagement timing of the clutch can be made to be the same regardless of the engaging position of the engaging claw of the clutch means and the driven body. A good controllability of the start can be compensated.

According to the invention described in claim 4, when the stop torque is released, the rotor of the ultrasonic motor rotates integrally with the driven body with the friction torque controlled by the frequency of the standing wave or the like. Therefore, the moving speed of the driven body can be controlled to a low speed, and the generation of shock, vibration, noise, etc. can be suppressed.

According to the fifth aspect of the present invention, the rising speed of the front curtain and the rear curtain can be increased, the shutter speed can be controlled with high accuracy, and the shutter speed itself can be increased. can do.

According to the sixth aspect of the present invention, it is possible to reduce the influence of the camera shake caused by the traveling shock of the shutter curtain at low speed.

According to the invention described in claim 7, the speed at the start of the flip-up operation of the movable mirror can be increased, and the flip-up speed of the movable mirror itself can be increased.

According to the eighth aspect of the present invention, it is possible to reduce the vibration generated at the time of flipping up, to shorten the time required for stabilization of the stillness, and to minimize the camera shake.

[Brief description of drawings]

FIG. 1 is a side view of a shutter device according to a first embodiment of the present invention, showing a charge completed state.

FIG. 2 is a front view of FIG.

FIG. 3 is a side sectional view of the shutter device of FIG.

FIG. 4 is a front view showing a shutter blade system of the shutter device of FIG.

5 is an exploded perspective view of a clutch plate and a drive lever of the shutter device of FIG.

6 is a block diagram showing a drive circuit of an ultrasonic motor in the shutter device of FIG.

FIG. 7 is a diagram showing the relationship between the frequency of a standing wave generated in the ultrasonic motor and the resistance torque.

8 is a diagram showing a relationship between drive speeds of a front curtain and a front curtain clutch plate in the shutter device of FIG.

9 is an enlarged side view of a drive lever and a clutch plate in the shutter device of FIG.

10 is an enlarged side view of a drive lever and a clutch plate in the shutter device of FIG. 1, showing a state where the clutch is disengaged.

11 is a front view showing an exposure completed state in the shutter device of FIG.

12 is a diagram showing a positional relationship between clutch pawls and gear teeth in the shutter device of FIG.

13 is a block diagram of a camera having the shutter device of the embodiment of FIG.

14 is a flowchart showing the operation of the camera of FIG.

15 is a flowchart showing an operation between S-10 and S-11 in FIG.

FIG. 16 is a side view of a focal plane shutter showing a second embodiment.

FIG. 17 is a front view of FIG.

FIG. 18 is a side view of the mirror driving device according to the third embodiment, showing the mirror-down state.

FIG. 19 is a front view of FIG. 18.

FIG. 20 is a front view of the mirror driving device according to the third embodiment, showing the mirror-up state.

FIG. 21 shows a side view of FIG.

FIG. 22 is a block diagram of a camera having a third embodiment.

23 is a flowchart showing the operation of the camera of FIG.

[Explanation of symbols]

1 ... Shutter base plate 3 ... Front curtain group 4 ... Rear curtain group 6 ... Front curtain drive lever 7 ... Front curtain drive spring 9 ... Front curtain clutch plate 12 ... Front curtain drive ultrasonic motor 13 ... Rear curtain drive lever 14 ... Rear curtain Drive spring 15 ... Rear curtain clutch plate 300 ... Mirror 301 ... Mirror receiving plate 303 ... Tensile spring 307 ... Mirror box wall surface 308 ... Ultrasonic motor 309 ... Clutch plate 311 ... Relay gear

Claims (8)

[Claims] 1. A driven body driven in one direction by a biasing force of a biasing means, an ultrasonic motor for charging the driven body against the biasing force of the biasing means, and the driven body. Clutch means for connecting and disconnecting the rotor output of the ultrasonic motor to and from the driving body, the clutch means rotating the rotor by the forward rotation of the rotor in the charging direction of the driven body. A drive device characterized in that the drive device is connected to the rotor and the rotor is reversely rotated to release the connection with the driven body. 2. The clutch means according to claim 1, wherein the clutch means has a rotating member having an engaging claw that engages with the driven body, a clutch spring for urging the rotating member toward the driven body, and an ultrasonic wave. It is characterized by comprising a helical gear that moves the rotating member toward the driven body by the forward rotation of the rotor of the motor, and a helical gear that moves the rotating member in the direction away from the driven body by the reverse rotation of the rotor. Drive. 3. The drive device according to claim 2, wherein the ratio of the number of teeth of the helical gear of the clutch means to the number of claws of the engaging claws (number of teeth / number of claws) is an integer. 4. The control means for driving and controlling the ultrasonic motor according to claim 1, wherein when the driven body is in a charged state, only a standing wave is excited in a transducer forming the ultrasonic motor. A drive device having a stop torque canceling mode. 5. A camera using the drive device according to claim 1, 2, 3 or 4 as drive sources for a front curtain and a rear curtain of a focal plane shutter, respectively. A camera, characterized in that the body is the front curtain and the second curtain, and a charging operation of a shutter is performed by forward rotation of an ultrasonic motor, and a release operation is performed by reverse rotation of the ultrasonic motor. 6. The camera according to claim 5, wherein the stop torque release mode operates when the shutter speed is slower than a fixed value. 7. A camera using the drive device according to claim 1, 2, 3, or 4 as a drive mechanism for a movable mirror, wherein a driven body of the drive device is a movable mirror, and an ultrasonic wave is used. A camera characterized in that a movable mirror is charged by forward rotation of a motor, and the movable mirror is flipped up by reverse rotation of the ultrasonic motor. 8. The camera according to claim 7, wherein the camera has a movable mirror low-speed mode in which the stop-torque releasing mode is operated to reduce the jumping speed of the movable mirror to a low speed.