JP2790258B2 - Drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device, and more particularly, to a driving device having clutch means using a planetary gear mechanism.

[Prior Art] Conventionally, there have been provided various types of driving devices for applying a plurality of loads by a reversible driving source such as a motor. One of the driving devices is a driving device using a clutch means including a planetary gear mechanism. The device is often used in cameras and the like.

For example, in an exposure / focus adjustment apparatus for a camera disclosed in Japanese Patent Application Laid-Open No. 63-294538, an exposure control mechanism and a focus adjustment mechanism are supplied with a driving force from one drive source via a clutch comprising a planetary gear mechanism. To selectively transmit the information. That is, as shown in FIG. 13 (A), a planetary gear 102 revolving around the sun gear 101 while rotating around the sun gear 101 is engaged with the sun gear 101, and the two shafts are connected by an arm 103. A planetary gear clutch 104 is formed, and an output gear 105 of one driving source such as a reversible motor is engaged with a sun gear 101 of the clutch 104 to form a sun gear 101.
And the planetary gear 102 is disposed so as to be selectively engaged with the exposure control mechanism driving gear 106 and the focus adjustment mechanism driving gear 107.

In the exposure / focusing apparatus configured as described above, when the motor rotates forward and the output gear 105 rotates clockwise, the sun gear 101 rotates counterclockwise.
03 rotates counterclockwise about the axis of the sun gear 101, and the planetary gear 102 meshes with the focus adjustment mechanism driving gear 107. After meshing, the planetary gear 102 rotates the gear 107 in a counterclockwise direction to perform a focus adjustment operation. Thereafter, when the motor reversely rotates, the sun gear 101 rotates clockwise, so that the arm 103 rotates clockwise about the axis of the sun gear 101, and the planetary gear 102 meshes with the exposure control mechanism driving gear 106, By rotating the gear 106 to activate the exposure control mechanism,
An exposure control operation is performed.

In this way, by using the planetary gear clutch 104, one load is driven by rotation of the drive source in one direction, and the other load is driven by rotation of the drive source in the other direction.

Japanese Patent Application Laid-Open No. 61-172127 discloses that a planetary gear clutch is used to selectively switch and transmit the driving force of a motor to a lens barrel and a film rewinding shaft, and to perform autofocusing. Therefore, when the driving force is transmitted to the lens barrel, the focus is adjusted by moving the photographing lens back and forth, so that electromagnetic means is used so that the forward driving force and the reverse driving force of the motor are transmitted. Technical means for preventing switching of the clutch are disclosed.

In this way, using the same planetary gear clutch,
The switching drive means such as the electromagnetic means can transmit the rotational driving force of the drive source in both directions to one load.

[Problems to be Solved by the Invention] As described above, various types of planetary gear clutches are conventionally used in cameras, but in cameras, it is desired to transmit both forward and reverse rotational driving forces of a driving source to one load. There are many cases. For example, when the shutter is opened and closed, the lens is moved forward and backward for autofocus, and the zoom lens is moved forward and backward in the television direction and the wide direction, a single load is used to rotate the drive source in both forward and reverse directions. I have to convey the power.

However, if the rotational driving force in both directions is transmitted to one load without adding any means, the following problem occurs. That is, as shown in FIGS. 13 (B) and 13 (C), when transmitting a rotational force in one direction to one load, for example, when the sun gear 101 is driven in a counterclockwise direction, the planetary gear 102 force F ₂ applied from the force F ₁ and the load gear 108 receive from
The resultant force F _3, and about to be Roll the cell around the sun gear 101 in the counterclockwise direction, it rotates the driven gear 108.

However, when trying to transmit the rotating force in the other direction to this one load and rotating the sun gear 101 clockwise, the thirteenth
As shown in FIGS. 3D and 3E, the planetary gear 102 is a sun gear 101.
F _{3 of the} force F ₁ received from the load gear 108 and the force F ₂ received from the load gear 108
As a result, the load gear 108 is rotated clockwise around the sun gear 101 and deviates from the load gear 108, and the load gear 108 cannot be rotated in both directions by reversing the rotation direction of the sun gear 101.

Therefore, in the prior art, the planetary gear is prevented from coming off the load gear by using a blocking means composed of electromagnetic means as shown in the above-mentioned JP-A-61-172127, and this additional means is not used. In this case, as shown in Japanese Patent Application Laid-Open No. 1-97930, a motor dedicated to the shutter transmits rotation in both forward and reverse directions to a shutter driving mechanism, and a single driving source is used as in a method of directly driving a shutter. A simple method of driving one load exclusively must be adopted.

As described above, in the conventional motor, there is a disadvantage that the driving of one load system can be performed only in one direction by the planetary gear clutch alone.To drive one load system in both directions, electromagnetic means such as a magnet is required. Use of special actuators is required when driving two or more load systems without using planetary gear clutches, because extra parts such as separation prevention means are required and costs increase. However, there is a disadvantage that various problems occur in space, cost, and electric circuit.

SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional drawbacks, drive two or more load systems with one drive source, and drive at least one load system in both forward and reverse directions without using extra components. An object of the present invention is to provide a driving device as described above.

[Means for Solving the Problems] A driving device according to the present invention includes a sun gear reciprocatingly rotated by a driving source, a planetary gear meshing with the sun gear, and selectively meshing with the planetary gear. A driven member, selected by the planetary gear, provided on the driven member meshed with the planetary gear, when rotating in one direction of the planetary gear, suppress the movement of the driven member, when rotating in the other direction A biasing means acting in a direction to promote this movement, and a stop member for stopping the driven member at an initial position in cooperation with the biasing means. The number of rotations of the drive source required for the rotation of the teeth is defined as n / m (n: integer, m; the number of torque ripples of the drive source).

[Operation] The planetary gear clutch operates by the rotation of the drive source in the first direction, the planetary gear meshes with the driven member, drives the same, acts as a load, and operates in a direction to suppress the movement of the driven member. The urging means is driven, and when the driving is completed, the driving source is rotated in the second direction. At this time, the rotation of the planetary gear is promoted so that the urging means drives the driving source in reverse through the planetary gear clutch. When the driven member moves back and comes into contact with the stop member and returns to the initial position, the planetary gear clutch is driven to switch to another type of load for the first time.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 1 shows a first embodiment of the present invention. In this embodiment, a shutter opening / closing mechanism 3 in a camera and a lens feeding mechanism 2 for auto-focusing by a driving device including a planetary gear clutch 1 are shown. And when the shutter opening / closing mechanism 3 is driven, the rotational driving force of the driving source in both directions is accurately transmitted.

The planetary gear clutch 1 includes a sun gear 5 attached to an output shaft of a drive source 4 composed of a reversible DC motor.
And a planetary gear 6 connected between the two shafts by an arm 7 while meshing with the same gear 5, and the planetary gear 6 rotating around the sun gear 5, rotates around the sun gear 5 in one direction. By rotating (rightward), it engages with the focusing cam gear 8 of the lens feeding mechanism 2, and conversely, by rotating in the other direction (leftward), the shutter opening / closing mechanism 3 and a swing member as a driven member It engages with the 9 sector gear 9b.

In the lens feeding mechanism 2, an end cam 8a having a ring-shaped planar shape is integrally formed on the upper surface of the focusing cam gear 8, and a driving pin 11a as a cam follower is pressed against the cam surface of the end cam 8a. doing. The drive pin 11a is fixed to a lower end surface of a vertical arm 11b of the lens frame 11 movably fitted to a vertical support shaft 18 fixed to the camera body 20, and is wound around an upper portion of the support shaft 18. Between the upper surface of the mounted vertical arm 11b and the camera body 20, it is urged downward by a coil spring 10 exerting its extension elasticity, and is pressed against the cam surface.

The mirror frame 11 is formed of an inverted L-shaped frame, and a photographing lens 17 is attached to a tip of a horizontal arm 11c extending laterally from an upper portion of the vertical arm 11b. The lens frame 11 is provided with a rotation stopping projection 11d protruding from the tip of the horizontal arm 11c, and the projection 11d is loosely sandwiched between the two vertical guide members 12a, 12b. The optical axis of the lens is held without rotating unnecessarily.

On the other hand, the shutter opening and closing mechanism 3 is
A shutter composed of two sector blades 14a and 14b disposed on the optical axis O, the rocking member 9 for driving the sector blades 14a and 14b to open and close, and a contraction constituting urging means in the present invention. The main part thereof is constituted by the flexible coil spring 16 and the stop member 15 which is a stopper for stopping the swing member 9 at the initial position.

The sector blades 14a and 14b are formed of thin plates having a wide sickle shape in plan view and are disposed so as to face each other, and their bases are rotatably supported by support shafts 13a and 13b. The sector drive pin 9a is passed through the common through hole of the sector opening / closing slit holes 14a 'and 14b' formed near the base. The sector drive pin 9a is fixedly planted on one arm of the swing member 9.

The swinging member 9 is swingably supported by a support shaft 19 at a portion closer to the right from the center thereof.
The sector drive pin 9a is erected on one arm extending downward from 14b '. The sector gear 9b is formed around the support shaft 19 on the opposite side of the one arm, and the planetary gear 6 is engaged with the sector gear 9b. Further, a contact portion 9c to the stop member 15 is formed at a portion of the one arm near the support shaft 19,
Further, a spring hook 9d is formed at the tip of one arm. The contractible coil spring 16 is stretched between the spring hook 9d and the stationary member of the camera, and the contracting elastic force of the spring 16 causes the swing member 9 to rotate clockwise around the support shaft 19. The swing member 9 is stopped at the initial position where the contact portion 9c contacts the stop member 15.

In this initial position, the sector drive pin 9a holds the shutter in a shutter closed state in which two sector blades 14a and 14b are overlapped. The opening / closing operation of the sector blades 14a and 14b is performed according to one sector blade 1
The tip 14a ″ of 4a is detected by turning on / off the photo interrupter 21.

In the driving device of this embodiment configured as described above, when the motor as the driving source 4 is driven to rotate clockwise, the sun gear 5 also rotates clockwise. The planetary gear 6 which rotates clockwise about the rotation axis of, and rotates counterclockwise meshes with the focusing cam gear 8. After the engagement, the rotational driving force is transmitted, so that the cam gear 8 rotates clockwise. When this rotates, the end face cam 8a pushes up the drive pin 11a, so that the lens frame 11 moves upward (as shown in FIG. 1) and starts to extend the photographing lens 17.

Then, based on the distance measurement data measured by the distance measuring means (not shown) while monitoring the position of the lens frame by means of the lens frame position detecting means (not shown), the photographing lens 17 is advanced to the lens position calculated in advance, The rotation of the motor 4 switches from clockwise to counterclockwise.

When the motor 4 is driven to rotate in the counterclockwise direction, the sun gear 5 also rotates in the counterclockwise direction. Accordingly, the arm 7 also rotates in the counterclockwise direction about the rotation axis of the sun gear 5 and rotates in the clockwise direction. The rotating planetary gear 6 comes off the focus cam gear 8.

In this state, the rotation of the focus cam gear 8 stops,
Keep the focused lens in the shooting position. When the motor continues to rotate in the counterclockwise direction, the arm 7 further rotates counterclockwise about the rotation axis of the sun gear 5, and the planetary gear 6 moves as shown in FIG. It engages with the No. 9 set gear 9b. When this engages, the rotational driving force of the motor is transmitted to the sector gear 9b through the planetary gear clutch 1, so that the swinging member 9 rotates counterclockwise around the support shaft 19 against the contraction elastic force of the coil spring 16. Then, the arm moves away from the stop member 15 for setting the initial position. Therefore, the contraction elasticity of the coil spring 16 is charged by the counterclockwise rotation of the swing member 9.

When the swing member 9 rotates counterclockwise, the sector drive pin 9a on one arm also moves counterclockwise, so that the sector opening / closing slit holes 14a 'and 14 into which the pin 9a is fitted.
b 'causes the sector blades 14a, 14b to start rotating in opposite directions about the support shafts 13a, 13b, respectively. When the tip 14a ″ of one of the sector blades 14a moves away from the photointerrupter 21, the photointerrupter 21 turns on. At the same time, the sector blades 14a and 14b start opening the imaging optical path, and the exposure time is reduced. (Time after the photo-interrupter 21 is turned on) is started, and when the time reaches the appropriate exposure calculated in advance based on the data measured by the photometric unit (not shown), the motor 4 is turned off. Is switched to clockwise rotation.

Then, as shown in FIG. 3, the rocking member 9 is rotated clockwise around the support shaft 19 by the release elasticity of the charged contraction elasticity of the coil spring 16, and the rotation of the rocking member 9 is performed. Promotes the rotation of the planetary gear 6 and drives the sun gear 5. As a result, the resultant force Fc of the force Fa received from the swing member 9 and the force Fb received from the sun gear 5 is applied to the planetary gear 6, so that the engagement between the planetary gear 6 and the sector gear 9b of the swing member 9 does not come off. When the swinging member 9 rotates clockwise due to the contracting elasticity of the spring 16, the sector blades 14a and 14b rotate in the directions to close the photographing optical path to close the photographing optical path and complete the exposure. The photo interrupter 21 is turned off when the tip 14a ″ of the sector blade 14a enters.

Further, when the swinging member 9 continues to rotate, and the abutting portion 9c of one arm thereof comes into contact with the stop member 15 serving as a stopper, the clockwise rotation of the swinging member 9 stops. Then, a force F _B sun gear 5 is rotated clockwise, the planetary gear 6 is received from the sun gear 5 by clockwise rotation of the motor 4 as shown in FIG. 4 is continued, the swinging member 9 engagement is disengaged with Sekutagiya 9b resultant force F _C of the force F _a applied from Sekutagiya 9b of.

When the engagement is released and the motor 4 continues to rotate clockwise, the arm 7 rotates clockwise, and the planetary gear 6 meshes with the focusing cam gear 8 again (see FIG. 1). Then, the focusing cam gear 8 rotates clockwise, and the end face cam 8a further pushes up the drive pin 11a, so that the lens frame 11 is further extended, but the drive pin 11a is moved by the cam 8a.
When the lens frame 11 gets over the vertex, the lens frame 11 returns to the retracted position (initial position). Here, the lens frame position detecting means (not shown) detects that the lens frame has returned to the initial position, and the driving of the motor as the drive source 4 is stopped.

As described above, according to the above-described embodiment, it is possible to reliably transmit the rotational force in one direction to the lens feeding mechanism 2 and the rotational force in both directions to the shutter opening / closing mechanism 3.

In this case, when the motor is rotated in the reverse direction without the spring 16 serving as the urging means, the planetary gear 6 is driven by the sector gear 9b of the swing member 9.
And the swing member 9 cannot be driven in reverse rotation. Further, the swing member 9 is driven, and the sun gear 5
Is stopped, the swinging member 9 is driven by the inertia of the swinging member 9 to generate a force for detaching the planetary gear 6 from the sector gear 9b, and the planetary gear 6 and the sector gear 9b are driven.
The shutter cannot be brought to a completely closed state due to disengagement, but such a problem is eliminated only by disposing the spring 16.

Further, in the above embodiment, the stop member 15 for stopping the swing member 9 at the initial position is provided, but this is achieved by using the inner ends of the slit holes 14a ', 14b' of the sector blades 14a, 14b as stopper portions. Of course, it is good.

By the way, in the shutter of the type in which the sector blades are opened and closed by the reciprocating rotation of the motor as in the first embodiment, if the sector blades are closed by the control of the motor after the motor is in a steady rotation, the inertia and the drive of the motor are reduced. It is difficult to output high-speed shutter time due to the inertia of the system. To solve this, as shown in the rise characteristics of the DC motor in FIG.
The initial range of the rise of the motor, that is, T shown in FIG.
By controlling the motor within the range, the high-speed shutter time can be output. However, a new problem arises here.

As is well known, a DC motor rotates by repeatedly attracting and repelling both an exciting coil and a magnetic pole. For example, the starting torque of a 2-pole 3-phase DC motor is as shown in FIG. As shown in (B), the torque ripple which becomes six peaks by one rotation of the rotor is exhibited depending on the rotor position at the start of the start. Therefore, if it is attempted to control the motor at the beginning of the rise of the motor, the rise characteristics are not stable due to the rotor position at the start of the start of the motor. This variation causes variation in the exposure aperture due to the sector blade, and the EE
It is difficult to ensure accuracy.

Thus, the present invention solves this problem as follows. That is, this countermeasure is to reduce the number of teeth of the planetary gear 6 and the reduction ratio from the motor in the first embodiment, the motor rotation amount required for the planetary gear to rotate by one tooth, n / m rotation, (n is (M is the number of torque ripples).

With this setting, the rotor position of the motor when the planetary gear 6 starts engaging with the sector gear 9b of the rocking member 9 can be kept constant. As a result, since the same starting torque of the torque ripple shown in FIG. 6A can be used for the rising characteristic of the motor from the start of rotation of the sector gear 9b of the swing member 9, a stable rising characteristic is always obtained. The drive of the lens frame 11 and the opening and closing of the sector blades can be performed by the forward / reverse control of the motor by the drive source 4 composed of two DC motors. You can use it stably and get high speed time.

For example, as shown in FIG.
Assuming that the number of teeth of the teeth and the planetary gear 6 is 6 teeth 6a to 6f, when the rotation of the motor is switched from clockwise to counterclockwise,
As shown in the figure, the planetary gear 6 revolves around the sun gear 5 in a counterclockwise direction, and stops at the position where the connecting arm 7 contacts the stopper 25. In this position, as shown in FIG. 8, the planetary gear 6 can engage with the sector gear 9b of the swing member 9. Further, if the motor continues to rotate counterclockwise,
As shown, the teeth 6a of the planetary gear 6 are the teeth of the sector gear 9b.
Meshing with 9f.

Further, after the rotation of the motor is switched in the counterclockwise direction, the output torque of the motor is reduced by lowering the voltage by duty driving or the like, and the planetary gear 6 is driven by the sector gear 9b.
Although it moves to the meshing position, it is set so that it cannot be charged by driving the load of the elastic coil spring 16 which is the urging means. Furthermore, since the swing member 9 is always in the same position in the initial position when the contact portion 9c abuts on the stop member 15, the first tooth with which the planetary gear 6 meshes is always the tooth 9f.

Here, after a lapse of time sufficient for the planetary gear 6 to move to the position shown in FIG. 9 after the motor is switched in the counterclockwise direction, the motor is driven at full rotation. Then, for the first time, the sector gear 9b rotates as shown in FIG. 10, and a shutter opening is formed.

The teeth that engage with the sector gear 9b at the beginning of the planetary gear 6 are not always the same, but the motor needs 1/6 rotation to drive one tooth of the planetary gear 6 (1/6 rotation). Therefore, the rotor position when the swinging member 9 starts to move can be started from the position of the starting torque which is always the same as the starting torque in FIG. 6 (A), and a stable rising characteristic can be obtained.

FIG. 11 is a perspective view of a driving device showing a second embodiment of the present invention. In the second embodiment, a lens feeding mechanism 2 for AF in a camera is rotationally driven in both forward and reverse directions by a driving device including a planetary gear clutch 1, and a tele (telephoto) / wide (wide angle) switching mechanism (hereinafter, referred to as a "wide-angle" switching mechanism). The T / W switching mechanism 30 is driven to rotate in one direction.

The lens feeding mechanism in the second embodiment is almost the same as the lens feeding mechanism 2 in the first embodiment except for the initial position stopping means and the urging means. Only explain,
The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

That is, a stop projection 8b is provided on the lower surface of the focusing cam gear 8 in the lens feeding mechanism 2 at a position near the outer edge. Then, the projection 8b abuts on the rotation path of the projection 8b, and the initial rotation position of the cam gear 8;
In other words, the stop member 15A that determines the initial movement position of the lens frame 11
Are arranged. The tip of the stop projection 8b
A compressible coil spring 16A, which is urging means, is stretched between the stationary member 8c and the stationary member, and the cam gear 8 rotates counterclockwise when the cam gear 8 is flat due to the contractive elastic force of the spring 16A.
The stop projection 8b abuts against the stop member 15A, and the focus cam gear 8 and the lens frame 11 are positioned at the initial position where the drive pin 11a is positioned at the non-cam portion.

The position where the planetary gear 6 of the planetary gear clutch 1 is disengaged from the cam gear 8 and switches to the other load is T / W
A drive gear 30 of the switching mechanism is provided.

According to the second embodiment thus configured, the motor 4
When the arm rotates counterclockwise, the arm 7 rotates counterclockwise, the planetary gear clutch 1 switches to the T / W switching mechanism, and the planetary gear 6 meshes with the drive gear 30 to operate the mechanism. A rear converter lens (not shown) is arranged in the photographing optical path. Then, the motor 4 switches the rotation in the clockwise direction. Then, the arm 7 rotates clockwise,
The planetary gear 6 engages with the focusing cam gear 8 stopped at the initial position by the stop projection 8b abutting against the stop member 15A due to the contraction elasticity of the coil spring 16A, and the cam gear 8 is reduced to the contraction elasticity of the spring 16A. In order to rotate in the clockwise direction, the driving pin 11a is pushed up by the end face cam 8a to move the lens frame 11 upward and move the photographing lens 17 to the focusing position. Thereby, the spring 16A is charged.

Then, after shooting at this in-focus position,
This time, the motor 4 rotates counterclockwise. Then, the cam gear 8 also rotates counterclockwise and moves back toward the initial position. At this time, the release elasticity of the charged spring 16A acts to promote the rotation of the planetary gear 6, and the sun gear 5
Will be driven. Accordingly, the resultant force of the force received from the cam gear 8 and the force received from the sun gear 5 is applied to the planetary gear 6 to prevent the engagement between the planetary gear 6 and the cam gear 8 from being disengaged. position,
That is, the photographing lens 17 can be moved back to the initial position.

When the motor 4 rotates in the counterclockwise direction, the planetary gear 6 is disengaged from the focusing cam gear 8 as in the first embodiment, and the planetary gear 6 is connected to the drive gear 30 of the T / W switching mechanism. In order to engage, the stop projection 8b of the cam gear 8 must be in contact with the stop member 15A. Therefore, if the configuration is made as in the second embodiment, T / W
It is guaranteed that the focus cam gear 8 is always at the initial position when the switching is performed, and that the focus cam gear 8 is always at the initial position when the extension of the lens is started after the T / W switching.

Therefore, according to the second embodiment, the following effects can be obtained. That is, as shown in FIG. 12, a slit disk 23 is provided integrally with the focusing cam gear 8, and a number of slits 23a formed in the outer peripheral edge of the disk 23 are read by the photo interrupter 24 to read a pulse signal. If the reading amount of the pulse signal is controlled as the extension amount of the lens, an effect that the initial position detection switch of the focusing cam gear 8 becomes unnecessary can be obtained.

In each of the above-described embodiments, the urging means uses the elastic coil springs 16 and 16A, but this may use not the elastic elasticity but the elastic elasticity. It is important that the planetary gear in the planetary gear clutch is used. When rotating in one direction, the movement of the driven member may be suppressed, and when rotating in the other direction, a spring acting in a direction that promotes this movement may be used.

[Effects of the Invention] As described above, according to the present invention, in a driving device using one driving source and a planetary gear clutch, the number of parts is reduced without using special electromagnetic blocking means unlike the conventional one. Thus, it is possible to provide a drive device that can drive two or more load systems and can stably drive at least one of the load systems in both the forward and reverse directions without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a drive unit showing a first embodiment of the present invention, FIG. 2 is a perspective view showing an operation state of the drive unit of FIG. 1, FIG. 3 and FIG. FIGS. 1 and 2 are plan views showing the operation of the planetary gear clutch, respectively. FIG. 5 is a diagram showing the start-up characteristics of a DC motor which is a drive source used in the above-mentioned drive device. B) is a diagram showing the torque ripple and the rotor position of the DC motor, respectively. FIG. 7 is a plan view showing the relationship between the planetary gear clutch and the driven member in the drive device according to the present invention. FIG. 10 is a plan view showing the operation of the planetary gear clutch of FIG. 7, respectively. FIG. 11 is a perspective view of a drive device showing a second embodiment of the present invention. FIG. 12 is a second embodiment of the present invention. 13 (A) to 13 (E) are plan views of a slit disk applied to the drive device of FIG. 13 (A) is a plan view, FIGS. 13 (B) and 13 (D) are operation diagrams, and FIGS. 13 (C) and (E) show an example of a conventional drive device using a ear clutch. ) Is a diagram showing the resultant force. 1 planetary gear clutch 4 DC motor (drive source) 5 sun gear 6 planetary gear 9 swing member (driven member) 9b sector gear (driven member) 15, 15A stop member 16,16A …… Coil spring (biasing means)

Claims (2)

(57) [Claims] A sun gear reciprocatingly rotated by a drive source; a planetary gear meshing with the sun gear; a driven member selectively meshed with the planetary gear; It is provided on the driven member meshed with the planetary gear, and when the planetary gear rotates in one direction, the movement of the driven member is suppressed, and when the planetary gear rotates in the other direction, it acts in a direction that promotes this movement. A drive device comprising: biasing means; and a stop member that stops the driven member at an initial position in cooperation with the biasing means. 2. The method according to claim 1, wherein the number of rotations of the drive source required for rotation of one tooth of the planetary gear is n / m (n: integer, m; the number of torque ripples of the drive source). Drive.