CN107636529B

CN107636529B - Drive unit with actuator, focal plane shutter system, photographing device, and electronic apparatus

Info

Publication number: CN107636529B
Application number: CN201680031643.XA
Authority: CN
Inventors: 铃木悠介
Original assignee: Nidec Copal Corp
Current assignee: Nidec Copal Corp
Priority date: 2015-03-31
Filing date: 2016-03-25
Publication date: 2021-03-05
Anticipated expiration: 2036-03-25
Also published as: WO2016158742A1; JP6407787B2; JP2016194605A; CN107636529A

Abstract

The actuator (110) is provided with: a plurality of rotors (113a, 113b) having mutually parallel rotational axes (J21, J22) and magnetized by different magnetic poles in the circumferential direction; a plurality of yokes (112a, 112b) that magnetically connect the rotors (113a, 113b) to each other and form one closed magnetic path (MP2) together with the plurality of rotors (113a, 113 b); and a plurality of coils (111a, 111b) provided on each of the plurality of yokes (112a, 112b) to excite each of the plurality of yokes. One end and the other end of each yoke (112a, 112b) face different rotors (113a, 113b), and each rotor (113a, 113b) is sandwiched by two yokes (112a, 112b) magnetically coupled to the rotor (113a, 113b) in a direction perpendicular to the rotation axis (J21, J22) of the rotor (113a, 113 b).

Description

Drive unit with actuator, focal plane shutter system, photographing device, and electronic apparatus

Technical Field

The invention relates to an actuator, and a drive unit, a focal plane shutter system, a photographing device, and an electronic apparatus having the actuator.

Background

A focal plane shutter for a photographing apparatus, having: a base plate provided with an opening through which light from an object passes; a blade for opening and closing the opening; and a mechanism for driving the blade. For example, patent document 1 discloses a mechanism for driving blades using an actuator having a stator that can be excited by energizing a coil and a magnetized rotor.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2012-215658

In recent years, an increase in the size of an imaging element of an imaging device has been desired. Further, it is expected to increase the shutter speed of the imaging device.

If the photographing element of the photographing device is enlarged, the opening of the bottom plate is also enlarged, and thus the blade for opening and closing the opening of the bottom plate is also enlarged. In order to drive the large blade, it is preferable that the driving force of the actuator for driving the blade (i.e., the driving force of the actuator) be increased. In addition, in order to increase the moving speed of the blade and increase the shutter speed, it is also desirable to increase the driving force of the actuator.

In order to increase the driving force of the actuator, the actuator becomes larger if a yoke (stator) excited by supplying current to a rotor and a coil of the actuator is increased. Further, if the yoke is enlarged, the diameter of the coil wound around the yoke is also increased, and the actuator is also increased.

Since the actuator becomes large, the focal plane shutter also becomes large.

In addition, in order to increase the driving force of the actuator, the inductance of the coil increases when the number of turns of the coil is increased, and therefore, the time for waiting for the actuator to operate becomes long.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an actuator that is small and can generate a large driving force, and a driving unit, a focal plane shutter system, an imaging device, and an electronic apparatus that include the actuator.

Disclosure of Invention

Technical scheme for solving problems

In order to achieve the above object, an actuator according to a first aspect of the present invention includes:

a plurality of rotors having rotating shafts parallel to each other and magnetized by different magnetic poles in a circumferential direction;

a plurality of yokes magnetically coupling the rotors to each other and forming a closed magnetic path together with the plurality of rotors; and

a plurality of coils provided on each of the plurality of yokes to excite each of the plurality of yokes,

one end and the other end of each of the yokes face different ones of the rotors,

each of the rotors is sandwiched between two yokes magnetically coupled to the rotor in a direction perpendicular to a rotation axis of the rotor.

According to this structure, the actuator rotates the plurality of rotors so that the magnetic flux excited by the plurality of coils acts on each rotor, and therefore, the actuator can generate a large driving force. In addition, the actuator can be miniaturized.

A magnetic path length between the coil-side end of the rotor-facing surface of each of the plurality of yokes and the end of the rotor-facing surface of the coil may be equal.

According to this configuration, the distribution of the magnetic lines of force acting on the rotor is uniform, and therefore the actuator can generate a constant driving force regardless of the rotational direction of the rotor.

The actuator has two said rotors and two said yokes,

the two magnetic yokes are arranged in an opposite direction,

an end portion of one of the two yokes and an end portion of the other yoke may sandwich each of the rotors.

According to this structure, the actuator rotates the two rotors so that the magnetic flux excited by the two coils acts on each rotor, and therefore, the actuator can generate a large driving force.

The plurality of coils are constituted by one winding, and each of the plurality of yokes may be excited in a circumferential direction of the magnetic circuit.

With this configuration, the circuit for supplying power to the coil can be simplified.

Each coil of the plurality of coils may be formed of an electrically separate winding.

According to this configuration, the power supplied to the coil can be adjusted for each coil.

A drive unit according to a second aspect of the present invention includes:

the above-mentioned actuator;

a main gear rotating around a rotation axis parallel to the rotation axis of the rotor; and

and a pinion gear engaged with the main gear, provided on each of the rotors, and rotating around a rotation axis of the rotor.

According to this configuration, the driving unit can rotate one rotating object with a large driving force.

A focal plane shutter according to a third aspect of the present invention includes:

a bottom plate having an opening;

a blade member for opening and closing the opening;

a driving part that drives the blade part by rotating; and

an actuator that rotates the drive member,

the actuator has:

the drive member has:

a main gear coupled to the blade member and rotating about a rotation axis parallel to a rotation axis of the rotor; and a pinion gear engaged with the main gear, provided on each of the rotors, and rotating around a rotation axis of the rotor,

According to this configuration, the blade member is driven by the actuator having a large driving force and a small size, and therefore, the focal plane shutter can drive the large blade member. In addition, a focal plane shutter may increase shutter speed. In addition, the focal plane shutter can be miniaturized.

In the above-described focal plane shutter,

the magnetic path length between the end of each of the plurality of yokes on the coil side of the surface facing the rotor and the end of the coil on the surface facing the rotor is equal

According to this configuration, the blade member is driven by a constant driving force, and therefore the focal plane shutter can operate stably.

In the above-described focal plane shutter,

the actuator has two of the rotors and two of the yokes,

the two magnetic yokes are oppositely arranged,

In the above-described focal plane shutter,

In addition, in the above-described focal plane shutter,

A focal plane shutter system according to a fourth aspect of the present invention includes:

the focal plane shutter; and

and a shutter control unit for supplying power to the plurality of coils and controlling the operation of the blade member.

In the above-described focal plane shutter system,

the shutter control unit includes:

a drive circuit for driving the blade member;

a control circuit for controlling the drive circuit; and

a power supply that supplies power to the drive circuit and the control circuit,

the drive circuit may have: a switching circuit for switching a direction of current flowing through the plurality of coils; and a voltage adjusting circuit for adjusting the magnitude of the voltage applied to the plurality of coils.

A photographing device according to a fifth aspect of the invention has the above-described focal plane shutter.

An electronic apparatus according to a sixth aspect of the present invention has the above-described focal plane shutter.

Effects of the invention

According to the present invention, since the actuator rotates the plurality of rotors and magnetic fluxes excited by the plurality of coils act on each rotor, a small-sized actuator with a large driving force can be provided. In addition, a small focal plane shutter having a large blade member and a high shutter speed can be provided.

Drawings

Fig. 1 is a front view showing a focal plane shutter according to embodiment 1 of the present invention.

Fig. 2 is a front view showing the focal plane shutter after the holder is removed according to embodiment 1 of the present invention.

Fig. 3 shows a front view of an actuator, a drive member and a blade member according to embodiment 1 of the present invention.

Fig. 4A is a schematic view showing a rotor, a yoke, and a coil of the actuator according to embodiment 1 of the present invention.

Fig. 4B is a schematic diagram showing a rotor, a yoke, and a coil of an actuator according to a comparative example.

Fig. 5 is a perspective view showing a base plate, an actuator, a driving member, and a shutter control section according to embodiment 1 of the present invention.

Fig. 6 is a diagram showing a shutter control section according to embodiment 1 of the present invention.

Fig. 7 is a diagram for explaining a control table of the shutter control section according to embodiment 1 of the present invention.

Fig. 8A is a schematic diagram showing the action of the focal plane shutter according to embodiment 1 of the present invention.

Fig. 8B is a schematic diagram showing the action of the focal plane shutter according to embodiment 1 of the present invention.

Fig. 9A is a schematic diagram showing the action of the focal plane shutter according to embodiment 1 of the present invention.

Fig. 9B is a schematic diagram showing the action of the focal plane shutter according to embodiment 1 of the present invention.

Fig. 10 is a front view showing an actuator according to embodiment 2 of the present invention.

Fig. 11 is a front view showing a focal plane shutter according to embodiment 3 of the present invention.

Fig. 12 is a diagram showing a shutter control section according to embodiment 4 of the present invention.

Fig. 13 is a diagram for explaining a control table of the shutter control section according to embodiment 4 of the present invention.

Detailed Description

(embodiment mode 1)

A focal plane shutter system according to an embodiment of the present invention is explained with reference to fig. 1 to 9B.

The focal plane shutter system according to the present embodiment includes: a focal plane shutter 1; and a shutter control section 3 for controlling the focal plane shutter 1. The focal plane shutter system or focal plane shutter 1 is mounted on an imaging device or an electronic apparatus having an imaging lens or the like. For example, the photographing device may be a digital camera, a surveillance camera, or the like. In addition, the electronic apparatus may be, for example, a portable terminal such as a smartphone having a shooting function, a laptop or notebook personal computer.

(focal plane shutter)

First, the focal plane shutter 1 will be described.

As shown in fig. 1, the focal plane shutter 1 is a square single-curtain type shutter. The focal plane shutter 1 has: a base plate 210, a blade member 140, an actuator 110, a drive member 130, a holder 220.

The blade member 140 has:

arm portions

141, 142; and a shutter curtain 150 composed of

blades

151, 152, 153, 154. The actuator 110 has:

rotors

113a, 113 b;

yokes

112a, 112 b; and

coils

111a, 111 b. The driving member 130 has: a main gear 131; and

pinions

133a, 133 b.

(baseboard)

The bottom plate 210 is formed in a flat plate shape. As shown in fig. 1 and 5, the bottom plate 210 includes: a rectangular opening 211; and a circular arc-shaped through hole 135. The through holes 135 are inserted with the driving pins 132 of the main gear 131.

Shafts

143, 144 are provided on the outer periphery of the opening 211 on the back surface side of the base plate 210, and the

shafts

143, 144 rotatably support the

arm portions

141, 142 of the blade member 140. The back side of the bottom plate 210 refers to the back side of the bottom plate 210 shown in fig. 1, and the front side of the bottom plate 210 refers to the front side of the bottom plate 210 shown in fig. 1.

A stopper 212 is provided on the outer periphery of the opening 211 on the back surface side of the bottom plate 210. For example, the stopper 212 restricts the movement of the arm 142 by electromagnetic force, and maintains a state in which the shutter curtain 150 of the blade member 140 shields the opening 211.

A shaft 134 is provided on a front surface side of the bottom plate 210, and the shaft 134 rotatably supports the main gear 131 of the driving part 130. The shaft 134 and the shaft 143 provided on the rear surface side are coaxially provided. The actuator 110, the driving member 130, and the holder 220 are disposed on the front surface of the base plate 210.

(blade member)

The blade member 140 moves by the driving force of the actuator 110 and opens and closes the opening 211 of the bottom plate 210.

As shown in fig. 1 and 3, the blade member 140 includes:

arm portions

141, 142; and a shutter curtain 150 composed of

blades

151, 152, 153, 154. The arm 141 is rotatably supported on the shaft 143 of the base plate 210. The arm 142 is rotatably supported on the shaft 144 of the base plate 210.

As shown in fig. 3,

blades

151, 152, 153, and 154 are connected to the arm 141 via

pins

141a, 141b, and 141c, respectively, and pins not shown, respectively. Further,

blades

151, 152, 153, and 154 are connected to the arm portion 142 via

pins

142a, 142b, 142c, and 142d, respectively.

Further, a through hole, not shown, of the arm portion 141 is inserted with the drive pin 132 of the main gear 131. Thereby, the arm 141 and the main gear 131 are coupled together. The

arms

141, 142 rotate with the rotation of the main gear 131.

As shown in fig. 2 and 3, the shutter curtain 150 is composed of

blades

151, 152, 153, and 154.

Each

blade

151, 152, 153, 154 is coupled to an

arm

141, 142, respectively. The

blades

151, 152, 153, and 154 move upward or downward when the focal plane shutter 1 is viewed in front, in conjunction with the rotation of the

arms

141 and 142.

For convenience of understanding, the moving direction of the

blades

151, 152, 153, and 154 will be referred to as the Z-axis direction, the upward direction as the + Z direction, and the downward direction as the-Z direction.

Specifically, the shutter curtain 150 is moved upward (+ Z direction) by each of the

blades

151, 152, 153, and 154, and is changed from the overlapped state to the unfolded state, thereby closing the opening 211 of the bottom plate 210. On the other hand, the shutter curtain 150 moves downward (-Z direction) by each of the

blades

151, 152, 153, and 154, and is changed from the spread state to the overlapped state, thereby opening the opening 211 of the bottom plate 210.

As shown in fig. 1, the overlapped state of the shutter curtain 150 is a state in which the

blades

151, 152, 153, and 154 are overlapped on the outer periphery of the opening 211 of the bottom plate 210. When the shutter curtains 150 are in the overlapped state, the opening 211 of the bottom plate 210 is opened.

As shown in fig. 2, the deployed state of the shutter curtain 150 refers to a state in which the

blades

151, 152, 153, 154 are deployed. When the shutter curtain 150 is in the deployed state, the opening 211 of the bottom plate 210 is closed by being shielded by the shutter curtain 150.

(actuator)

The actuator 110 is a driving source of the focal plane shutter 1. The actuator 110 moves the blade member 140 by rotating the driving member 130. As shown in fig. 1 and 2, the actuator 110 includes:

rotors

113a, 113 b;

elongated yokes

112a and 112 b; and

coils

111a, 111 b. Each

coil

111a, 111b is provided on a

yoke

112a, 112b, respectively, and is excited, respectively.

The actuator 110 has

yokes

112a and 112b arranged on the front surface of the base plate 210 so that the longitudinal direction thereof coincides with the Z-axis direction.

(rotor)

The

rotors

113a and 113b are arranged along the Z-axis direction. The rotor 113a is disposed on the + Z direction side, and the rotor 113b is disposed on the-Z direction side.

The

rotors

113a, 113b are cylindrical. The

rotors

113a and 113b are formed of permanent magnets magnetized by N poles and S poles aligned in a direction perpendicular to the central axis. That is, the

rotors

113a and 113b are magnetized by different magnetic poles in the circumferential direction. Each

rotor

113a, 113b rotates centering around each rotation axis J21, J22 parallel to the center axis of the shaft 143 of the base plate 210, according to the magnetic force generated by the

coils

111a, 111 b. It should be noted that each of the

rotors

113a, 113b is rotatably supported on the

shafts

222, 223 of the holder 220, respectively.

As shown in fig. 3, the

rotors

113a and 113b are provided with

pinions

133a and 133b of the driving member 130, respectively. The pinion 133a rotates together with the rotor 113a and the pinion 133b rotates together with the rotor 113 b. The sub-gears 133a, 133b are engaged with the main gear 131 of the driving part 130. The rotation of the

rotors

113a, 113b is transmitted to the blade member 140 through the sub-gears 133a, 133b of the driving member 130 and the main gear 131. Thereby, the blade member 140 moves.

(magnet yoke)

As shown in fig. 2 and 4A, the

yokes

112a and 112b are formed in an elongated shape from a magnetic material such as iron. The longitudinal direction of the

yokes

112a, 112b is along the Z-axis direction.

The yoke 112a is provided with a coil 111 a. The yoke 112a is excited by the coil 111 a. The yoke 112b is provided with a coil 111 b. The yoke 112b is excited by the coil 111 b.

The

yokes

112a and 112b are disposed to face each other. Further, one end P11 in the longitudinal direction of the yoke 112a and one end P21 in the longitudinal direction of the yoke 112b face the rotor 113a in a direction perpendicular to the rotation axis J21 of the rotor 113a, and sandwich the rotor 113 a. Further, the other end P12 in the longitudinal direction of the yoke 112a and the other end P22 in the longitudinal direction of the yoke 112b face the rotor 113b in a direction perpendicular to the rotation axis J22 of the rotor 113b, and sandwich the rotor 113 b.

Thus, the two

yokes

112a, 112b and the two

rotors

113a, 113b constitute one closed magnetic circuit MP2, so that one actuator 110 can rotate the two

rotors

113a, 113 b.

In the present embodiment, when the end P11 of the yoke 112a is excited to the N-pole and the end P21 of the yoke 112b is excited to the S-pole, the rotor 113a rotates counterclockwise. When the end P11 of the yoke 112a is excited as the S pole and the end P21 of the yoke 112b is excited as the N pole, the rotor 113a rotates in the clockwise direction. In addition, when the end P12 of the yoke 112a is excited to the N pole and the end P22 of the yoke 112b is excited to the S pole, the rotor 113b rotates in the clockwise direction. When the end P12 of the yoke 112a is excited as the S pole and the end P22 of the yoke 112b is excited as the N pole, the rotor 113b rotates in the counterclockwise direction.

The end P11 of the yoke 112a and the end P21 of the yoke 112b sandwich the rotor 113a, and the end P12 of the yoke 112a and the end P22 of the yoke 112b sandwich the rotor 113b, so that magnetic fluxes from each of the

excited yokes

112a, 112b act on the

rotors

113a, 113b, respectively. That is, magnetic fluxes excited by the two

coils

111a and 111b act on the

rotors

113a and 113b, respectively.

This increases the magnetic flux density acting on each of the

rotors

113a and 113 b.

As described above, the actuator 110 can rotate the two

rotors

113a, 113b, and the magnetic flux density acting on each

rotor

113a, 113b can be increased, so that a large driving force can be generated. For example, when the magnetomotive force F of each of the

coils

111a and 111b is F0 and the permeance P is P0, the

coils

111a and 111b are provided in the

yokes

112a and 112b, respectively, and thus the magnetic flux density Φ on the magnetic circuit MP2 is 2 × F0 × P0. Therefore, the magnetic flux density Φ of the magnetic flux acting on each

rotor

113a, 113b is 2 × F0 × P0.

In this case, magnetic flux acting on the rotor in an actuator having a conventional U-shaped yoke will be described as a comparative example.

In the comparative example, as shown in fig. 4B, an actuator 1110 having a rotor 113a and an actuator 1120 having a rotor 113B are combined.

The actuator 1110 has: rotor 113a, U-shaped yoke 1112, and coil 1111. The actuator 1120 has: rotor 113b, U-shaped yoke 1122, and coil 1121.

The

rotors

113a and 113b of the

actuators

1110 and 1120 are the same as the

rotors

113a and 113b of the actuator 110. The number of turns N of the

coils

1111 and 1121 is the same as that of the

coils

111a and 111b of the actuator 110, and the material constituting these.

The yoke 1112 of the actuator 1110 has:

leg pieces

1112a, 1112 b; and a connecting piece 1112 c connecting one end of the leg piece 1112a and one end of the leg piece 1112 b. The other end of leg piece 1112a and the other end of leg piece 1112b sandwich rotor 113 a. Thereby, a magnetic circuit MP11 is formed in the actuator 1110. Further, the coil 1111 is provided on the leg piece 1112 a.

The yoke 1122 of the actuator 1120, like the yoke 1112 of the actuator 1110, has:

leg pieces

1122a, 1122 b; and a connecting piece 1122 c. One end of leg 1122a and one end of leg 1122b sandwich rotor 113 b. Thereby, a magnetic circuit MP12 is formed in the actuator 1120. The coil 1121 is provided on the leg 1122 a.

In the magnetic circuit MP2 of the actuator 110 and the magnetic circuit MP11 of the actuator 1110, when the magnetic circuit length L, the cross-sectional area a of the magnetic circuit, and the magnetic permeability μ are equal, and the magnetomotive force F in the

coils

111a, 111b of the actuator 110 and the coil 1111 of the actuator 1110 is equal, P is μ × a/L, and therefore, the magnetic flux density Φ in the magnetic circuit MP11 is F0 × P0. Further, assuming that the magnetic flux density Φ in the magnetic circuit MP12 is also the same as that of the actuator 1110, the magnetic flux density Φ is also F0 × P0.

Therefore, the magnetic flux density Φ of the magnetic flux acting on the rotor 113a of the actuator 1110 and the rotor 113b of the actuator 1120 is F0 × P0.

As described above, in the comparative example in which the actuator 1110 and the actuator 1120 are combined, the magnetic flux density Φ of the magnetic flux acting on the rotor 113a and the rotor 113b, respectively, is half of the magnetic flux density Φ of the magnetic flux acting on each of the

rotors

113a, 113b in the actuator 110.

The driving force of the actuator is proportional to the magnetic flux density Φ of the magnetic flux acting on the rotor, and therefore, the actuator 110 can generate the driving force 2 times as much as the comparative example with the same power consumption as the comparative example.

(coil)

Each

coil

111a, 111b is disposed on a

yoke

112a, 112b, respectively. The coil 111a excites the yoke 112 a. The coil 111b excites the yoke 112 b.

The

coils

111a and 111b are made of a conductive material such as copper. Each

coil

111a, 111b is formed by an electrically separate winding.

As shown in fig. 5, the coil 111a is connected to the shutter control section 3 through wires LP11 and LP 12. The coil 111b is connected to the shutter control section 3 through wires LP21 and LP 22.

When the shutter control unit 3 supplies power to the coil 111a and the coil 111b via the wirings LP11, LP12, LP21, and LP22, the yoke 112a and the yoke 112b are excited.

Here, a description will be given of a position where each of the

coils

111a and 111b is provided on the

yokes

112a and 112b, respectively.

As shown in fig. 4A, the

coils

111a and 111b are arranged such that a magnetic path length L11 between a surface S11 of the yoke 112a facing the rotor 113a and the coil 111a, a magnetic path length L12 between a surface S12 of the yoke 112a facing the rotor 113b and the coil 111a, a magnetic path length L21 between a surface S21 of the yoke 112b facing the rotor 113a and the coil 111b, and a magnetic path length L22 between a surface S22 of the yoke 112b facing the rotor 113b and the coil 111b are equal to each other (L11 ═ L12 ═ L21 ═ L22). The magnetic path length L11 between the surface S11 of the yoke 112a facing the rotor 113a and the coil 111a is the magnetic path length between the end of the surface S11 on the coil 111a side and the end of the coil 111a on the surface S11 side. The magnetic path lengths L12, L21, and L22 are also the same as the magnetic path length L11.

Here, "equal" means equal within a predetermined error range. For example, the error range may be set to a size that can be ignored depending on the difference in the rotation direction of the

rotors

113a and 113 b.

Since the magnetic path lengths L11, L12, L21, L22 are equal, the distribution of the magnetic lines of force acting on each

rotor

113a, 113b is uniform, so that the actuator 110 can generate a constant driving force regardless of the rotational direction of the

rotors

113a, 113 b.

On the other hand, in the actuator 1110 as a comparative example, since the coil 1111 is provided on one leg 1112a of the yoke 1112, the magnetic path length L111 between the coil 1112 and one surface S111 of the yoke 1112 facing the rotor 113a is different from the magnetic path length L112 between the other surface S112 of the yoke 1112 facing the rotor 113 a. Therefore, in the actuator 1110, the distribution of the magnetic lines of force acting on the rotor 113a is not uniform, and it is difficult to generate a stable driving force. In the actuator 1120 as a comparative example, it is also difficult to generate a stable driving force, as in the actuator 1110.

(drive unit)

The driving part 130 is rotated by the

rotors

113a, 113b of the actuator 110, thereby driving the blade part 140. As shown in fig. 3, the driving member 130 has: a main gear 131, sub-gears 133a and 133 b.

As shown in fig. 5, the main gear 131 has: an insertion hole 131a and a drive pin 132. The main gear 131 is rotatably supported on the shaft 134 by inserting the shaft 134 of the bottom plate 210 into the insertion hole 131 a. The main gear 131 rotates about a rotation shaft J1 parallel to the rotation shafts J21, J22 of the

rotors

113a, 113b of the actuator 110. In addition, the main gear 131 meshes with the sub-gears 133a and 133 b.

The driving pins 132 of the main gear 131 are inserted into the through holes 135 of the bottom plate 210 and into the through holes of the arm portions 141. Thereby, the main gear 131 and the arm 141 are coupled.

The

pinions

133a, 133b are fan-shaped. Each of the sub-gears 133a, 133b is engaged with the main gear 131.

For example, each of the sub-gears 133a, 133b is provided on the

rotors

113a, 113b, respectively, by fitting. The pinion gear 133a rotates together with the rotor 113a about the rotation shaft J21 of the rotor 113 a. The pinion gear 133b rotates together with the rotor 113b about the rotation shaft J22 of the rotor 113 b.

According to these configurations, when the

rotors

113a, 113b of the actuator 110 rotate, the pinion 133a rotates about the rotation shaft J21, and the pinion 133b rotates about the rotation shaft J22. The rotation of the sub-gears 133a, 133b is transmitted to the main gear 131. By the rotation of the main gear 131, the drive pins 132 of the main gear 131 also rotate about the rotation shaft J1, and the arm portions 141 coupled to the drive pins 132 rotate. By the rotation of the arm 141, the arm 142 also rotates. Further, the

blades

151, 152, 153, 145 move as the arm 141 rotates.

(holding member)

The holder 220 serves to hold the actuator 110. The holder 220 is fixed to the front surface of the base plate 210. For example, the holder 220 is formed of synthetic resin.

As shown in fig. 5, the holder 220 has: a holder body 220a and a cover 220 b. The holder body 220a is provided with: a shaft 222 rotatably supporting the rotor 113 a; and a shaft 223 rotatably supporting the rotor 113 b. The cover 220b is fixed to the holder body 220 a.

(shutter control section)

Next, the shutter control section 3 will be explained.

The shutter control unit 3 supplies power to the

coils

111a and 111b, and controls the operation of the blade member 140. As shown in fig. 6, the shutter control section 3 has a battery 300, a control circuit 310, and a drive circuit 320.

(Battery)

The battery 300 supplies power to the control circuit 310 and the drive circuit 320. For example, the battery 300 supplies a voltage of 3.2V to 2.2V to the driving circuit 320 and the control circuit 310.

(drive circuit)

The driving circuit 320 supplies power to the

coils

111a and 111b, thereby driving the blade member 140. The driving circuit 320 has switching

circuits

321, 322 and

voltage adjusting circuits

323, 324.

The switching circuit 321 can switch the direction of the current flowing through the coil 111 a. The switching circuit 322 can switch the direction of the current flowing through the coil 111 b. The switching circuit 321 is a bridge circuit including four transistors Tr11, Tr12, Tr13, Tr 14. The switching circuit 322 is also a bridge circuit including four transistors Tr21, Tr22, Tr23, Tr 24.

Here, for convenience of understanding, it is assumed that when a current flows from the left side to the right side of the coil 111a in fig. 6, in fig. 8A to 9B, the end P11(+ Z direction side) of the yoke 112a is excited as the N pole, and the end P12(-Z direction side) of the yoke 112a is excited as the S pole. Further, when a current flows from the left side to the right side of the coil 111B in fig. 6, in fig. 8A to 9B, the end P21(+ Z direction side) of the yoke 112B is excited as the N pole, and the end P22 (-Z direction side) of the yoke 112B is excited as the S pole.

The

voltage adjusting circuits

323 and 324 adjust the magnitude of the voltage supplied to the

coils

111a and 111 b.

The voltage adjustment circuit 323 is a voltage divider circuit in which resistors R11 and R12 are connected in series. The voltage generated between the resistor R11 and the resistor R12 is supplied to the switching circuit 321. The resistor R11 is a variable resistor. The voltage adjustment circuit 324 is also composed of a voltage divider circuit in which resistors R21 and R22 are connected in series, similarly to the voltage adjustment circuit 323. The resistor R21 is a variable resistor. By adjusting the resistance values of the resistors R11 and R21, which are variable resistors, the voltage supplied to each of the switching

circuits

321 and 322 can be adjusted.

(control Circuit)

The control circuit 310 is used to control the driving circuit 320. The control circuit 310 has a CPU (central processing unit) and a memory unit. The control circuit 310 controls the resistance values of the transistors Tr11, Tr12, Tr13, Tr14, Tr21, Tr22, Tr23, Tr24 of the switching

circuits

321, 322 and the resistors R11, R21 of the

voltage adjustment circuits

323, 324, respectively, by executing a program stored in the storage section by the CPU.

For example, the control circuit 310 is connected to an input device (not shown) of a digital camera equipped with the focal plane shutter system of the present embodiment. When an operation button of an input device of the digital camera is pressed, the input device outputs a start signal indicating the start of shooting to the control circuit 310. When a start signal is input, the control circuit 310 controls the drive circuit 320.

For example, a control table is stored in the storage unit of the control circuit 310. Fig. 7 shows a control table stored in the storage section of the control circuit 310. The 1 st column in fig. 7 indicates the action of the blade member 140. In addition, columns 2 to 9 in fig. 7 show on/off states of the transistors Tr11, Tr12, Tr13, Tr14, Tr21, Tr22, Tr23, and Tr24 of the switching

circuits

321 and 322.

When the

vanes

151, 152, 153, and 154 are moved to change the state of the shutter curtain 150 from the overlapped state to the deployed state, as shown in fig. 7, the control circuit 310 turns on the transistors T r11 and Tr14 of the switching circuit 321 and the Tr22 and Tr23 of the switching circuit 321. The control circuit 310 turns off the transistors Tr12 and Tr13 of the switching circuit 321 and the transistors Tr21 and Tr24 of the switching circuit 322.

Accordingly, since the current flows from the left side to the right side of the coil 111a in fig. 6, the end P11 of the yoke 112a is excited to the N-pole and the end P12 is excited to the S-pole as shown in fig. 8A and 8B. In fig. 6, since the current flows from the right side to the left side of the coil 111B, the end P21 is excited as the S pole and the end P22 is excited as the N pole, as shown in fig. 8A and 8B.

When the yokes 112a, 112B are excited as described above, the rotors 113a, 113B and the pinions 133a, 133B rotate in the counterclockwise direction, and therefore, as shown in fig. 8A and 8B, the main gear 131 rotates in the clockwise direction (refer to arrows AR11, AR12, AR 13). By the clockwise rotation of the main gear 131, the

blades

151, 152, 153, 154 move upward, and the shutter curtain 150 changes from the overlapped state to the deployed state (refer to an arrow AR 14).

On the other hand, when the

vanes

151, 152, 153, 154 are moved to change the state of the shutter curtain 150 from the deployed state to the overlapped state, as shown in fig. 7, the control circuit 310 turns on the transistors Tr12, Tr13 of the switching circuit 321 and the transistors Tr21, Tr24 of the switching circuit 322. The control circuit 310 turns off the transistors Tr11 and Tr14 of the switching circuit 321 and the transistors Tr22 and Tr23 of the switching circuit 322.

Accordingly, in fig. 6, since the current flows from the right side to the left side of the coil 111a, the end P11 of the yoke 112a is excited to the S pole, and the end P12 is excited to the N pole. In fig. 6, since the current flows from the left side to the right side of the coil 111b, the end P21 of the yoke 112b is excited to the N-pole, and the end P22 is excited to the S-pole.

When the yokes 112a, 112B are excited as described above, the rotors 113a, 113B and the pinions 133a, 133B rotate in the clockwise direction, and therefore, as shown in fig. 9A and 9B, the main gear 131 rotates in the counterclockwise direction (refer to arrows AR21, AR22, AR 23). By the rotation of the main gear 131 in the counterclockwise direction, the

blades

151, 152, 153, 154 move downward, so that the shutter curtain 150 changes from the deployed state to the overlapped state (refer to an arrow AR 24).

As described above, the shutter control section 3 can operate the blade member 140.

As described above, the actuator 110 can rotate the two

rotors

113a, 113b, and increase the magnetic flux density acting on each

rotor

113a, 113b, thereby generating a large driving force. In addition, the actuator 110 can rotate the two

rotors

113a, 113b in one magnetic circuit MP2, and thus becomes small. For example, the actuator 110 can realize the driving force 2 times as large as that of the comparative example with a half of the mounting area of the comparative example, as compared with the combination of the actuator 1110 and the actuator 1120 as the comparative example.

Further, in the actuator 110, the magnetic path lengths L11, L12, L21, L22 are equal, and therefore the distribution of the magnetic lines of force acting on each of the

rotors

113a, 113b is uniform. Thus, the actuator 110 can generate a constant driving force regardless of the rotation direction of the

rotors

113a and 113 b.

Since the blade member 140 of the focal plane shutter 1 is moved by the actuator 110 generating a large driving force via the driving member 130, the focal plane shutter 1 can drive the large blade member 140. Further, the focal plane shutter 1 can increase the shutter speed.

In addition, since the actuator 110 is miniaturized, the focal plane shutter 1 also becomes miniaturized. Further, since the blade member 140 is moved by the actuator 110 with a constant driving force, the focal plane shutter operates stably.

The shutter control unit 3 includes

voltage adjusting circuits

323 and 324, and can adjust the voltages applied to the

coils

111a and 111b, respectively, thereby adjusting the magnetic flux density Φ applied to the

rotors

113a and 113 b.

(embodiment mode 2)

Referring to fig. 10, an actuator 4110 according to the present embodiment will be described.

In embodiment 1, the actuator 110 has two coils, yokes, and rotors, respectively, but the number of coils, yokes, and rotors is not limited to two.

As shown in fig. 10, the actuator 4110 has three

coils

4111a, 4111b, 4111c, three

yokes

4112a, 4112b, 4112c, and three

rotors

4113a, 4113b, 4113 c.

Each of the

coils

4111a, 4111b, 4111c is disposed on a

yoke

4112a, 4112b, 4112c, respectively.

One end portion of yoke 4112a and one end portion of yoke 4112b sandwich rotor 4113 a. Further, the other end of yoke 4112b and one end of yoke 4112c sandwich rotor 4113 b. Further, the other end of yoke 4112c and the other end of yoke 4112a sandwich rotor 4113 c. Thus, the

yokes

4112a, 4112b, 4112c and the

rotors

4113a, 4113b, 4113c form a closed magnetic circuit MP4, and the actuator 4110 can rotate the

rotors

4113a, 4113b, 4113 c.

In the actuator 4110, magnetic flux excited by the three

coils

4112a, 4112b, 4112c acts on each

rotor

4113a, 4113b, 4113 c. Thereby, the magnetic flux density acting on each of the

rotors

4113a, 4113b, 4113c is increased.

As described above, the actuator 4110 can rotate the three

rotors

4113a, 4113b, 4113c, so that the magnetic flux density acting on each

rotor

4113a, 4113b, 4113c can be increased, and therefore, a large driving force can be generated as in the actuator 110.

In addition, as shown in fig. 10, pinion gears 4114a, 4114b, 4114c may be provided on each of the

rotors

4113a, 4113b, 4113c, respectively. Each of the sub-gears 4114a, 4114b, 4114c rotates about the rotation axis of each of the

rotors

4113a, 4113b, 4113 c. By providing a main gear (not shown) that meshes with each of the sub-gears 4114a, 4114b, 4114c, the actuator 4110 can rotate a rotating object with a large driving force. Further, in place of the actuator 110 and the driving section 130 of embodiment 1, an actuator 4110 having sub-gears 4114a, 4114b, 4114c and a main gear is provided at the focal plane shutter 1.

(embodiment mode 3)

A focal plane shutter system according to the present embodiment will be described with reference to fig. 11.

In embodiment 1, the focal plane shutter 1 is a single-curtain shutter, but the form of the focal plane shutter is not limited to this.

The focal plane shutter system according to the present embodiment has a focal plane shutter 2001. The focal plane shutter 2001 is a double curtain shutter.

As shown in fig. 11, the focal plane shutter 2001 has: two blade units each including an actuator 110, a driving unit 130, a blade member 140, and a holder 220; and a bottom plate 2210 having an opening 2211. Note that, in fig. 11, the holder 220 is not shown for ease of understanding.

The shutter curtain 150 of the blade member 140 of one blade unit is disposed above the opening 2211 in a superimposed state (+ Z direction). The shutter curtain 150 of the blade member 140 of the other blade unit is disposed below the opening 2211 in a superimposed state (-Z direction). Further, a stopper 2212 for restricting the movement of the arm 141 of the vane unit is provided on the outer periphery of the opening 2211 of the bottom plate 2210.

Further, the focal plane shutter system according to the present embodiment has a shutter control section (not shown) for controlling the action of the blade member 140 of each blade unit. The shutter control unit of the present embodiment includes a drive circuit and a control circuit similar to those of the shutter control unit 3 of embodiment 1.

In the present embodiment, the shutter curtain 150 disposed below the opening 2211 in the superimposed state is referred to as a front curtain 2251, and the shutter curtain 150 disposed above the opening 2211 in the superimposed state is referred to as a rear curtain 2252.

In this case, the shutter control unit of the present embodiment changes the state of the front curtain 2251 to the superimposed state, the extended state, and the superimposed state in this order. After a predetermined time, the shutter control unit of the present embodiment changes the state of the rear curtain 2252 to the overlapped state, the deployed state, and the overlapped state in this order. Thus, the digital camera having the focal plane shutter system of the present embodiment can capture an image of a subject by the image pickup element while the rear curtain 2252 is in the extended state from the folded state.

(embodiment mode 4)

The focal plane shutter system according to the present embodiment will be described with reference to fig. 12 and 13.

In embodiment 1, the

coils

111a and 111b are formed by electrically separated windings, but the

coils

111a and 111b may be formed by one winding.

The focal plane shutter system according to the present embodiment has a shutter control section 3003 instead of the shutter control section 3 of the focal plane shutter system according to embodiment 1. When the

coils

111a and 111b of the actuator 110 are viewed from the same direction (+ Z direction or-Z direction) along the center axis, the winding directions are opposite to each other. Thus, the

coils

111a and 111b can excite the

yokes

112a and 112b of the actuator 110, as in embodiment 1.

The other constitution is the same as that of the focal plane shutter system according to embodiment 1.

As shown in fig. 12, the shutter control section 3003 includes: a drive circuit 3320 having a battery 300 and a switching circuit 3321; and a control circuit 3310. The switching circuit 3321 is connected to the windings forming the

coils

111a and 111 b. The other configuration is the same as that of the switching circuit 321 in embodiment 1.

The control circuit 3310 includes a CPU and a memory unit, as in the control circuit 310 of embodiment 1. The control circuit 310 controls the transistors Tr31, Tr32, Tr33, and Tr34 of the switching circuit 3321, respectively, by executing a program stored in the storage section by the CPU.

A control table is stored in the storage unit of the control circuit 3310. Fig. 13 shows a control table stored in the storage unit of the control circuit 3310. The 1 st column in fig. 13 indicates the action of the blade member 140. In addition, columns 2 to 5 in fig. 13 show on/off states of the transistors Tr31, Tr32, Tr33, and Tr34 of the switching circuit 3321.

When the

vanes

151, 152, 153, and 154 are moved to change the state of the shutter curtain 150 from the superimposed state to the deployed state, the control circuit 3310 turns on the transistors Tr31 and Tr34 and turns off the transistors Tr32 and Tr33, as shown in fig. 13. Accordingly, since the current flows from the left side to the right side of the coil 111a in fig. 12, the end P11 of the yoke 112a is excited to the N-pole and the end P12 is excited to the S-pole as shown in fig. 8A and 8B. In fig. 12, since the current flows from the right side to the left side of the coil 111B, the end P21 is excited as the S pole and the end P22 is excited as the N pole, as shown in fig. 8A and 8B.

blades

On the other hand, when the

vanes

151, 152, 153, and 154 are moved to change the state of the shutter curtain 150 from the extended state to the superimposed state, the control circuit 3310 turns on the transistors Tr32 and Tr33 and turns off the transistors Tr31 and Tr34, as shown in fig. 13. Accordingly, in fig. 12, since the current flows from the right side to the left side of the coil 111a, the end P11 of the yoke 112a is excited to the S pole, and the end P12 is excited to the N pole. In fig. 12, since the current flows from the left side to the right side of the coil 111b, the end P21 of the yoke 112b is excited to the N-pole, and the end P22 is excited to the S-pole.

blades

As described above, the control circuit 3310 may operate the blade member 140. In addition, the driving circuit 3320 and the control circuit 3310 are simplified, and therefore the shutter control section 3003 can be miniaturized.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

In embodiment 1, the shutter curtain 150 is configured of 4

blades

151, 152, 153, 154, but the number of blades is not limited to 4, and for example, the number of blades may be 3 or 5.

In embodiment 1 and embodiment 3, the

focal plane shutters

1 and 2001 operate in the normally open mode in which the

openings

211 and 2211 are opened during imaging standby, but the

focal plane shutters

1 and 2001 may operate in the normally closed mode in which the

openings

211 and 2211 are closed during imaging standby.

The present application is based on Japanese patent application laid-open No. 2015-074480 filed on 31/3/2015. The entire specification, claims and drawings of Japanese laid-open application No. 2015-074480 are incorporated into this application by reference.

Description of reference numerals

1. 2001: focal plane shutter

3. 3003: shutter control unit

110. 4110: actuator

111a, 111b, 4111a, 4111b, 4111 c: coil

112a, 112b, 4112a, 4112b, 4112 c: magnetic yoke

113a, 113b, 4113a, 4113b, 4113 c: rotor

130: driving part

131: master gear

131 a: inserting hole

132: driving pin

133a, 133b, 4114a, 4114b, 4114 c: auxiliary gear

134. 143, 144, 222, 223: shaft

135: through hole

140: blade component

141. 142: arm part

141a, 141b, 141c, 142a, 142b, 142c, 142 d: pin

150: shutter curtain

151. 152, 153, 154: blade

210. 2210: base plate

211. 2211: opening of the container

212. 2212: stop piece

300: battery with a battery cell

310. 3310: control circuit

320. 3320: driving circuit

321. 322, 3321: switching circuit

323. 324: voltage regulation circuit

2251: front curtain

2252: rear curtain

J1, J21, J22: rotating shaft

L11, L12, L13, L14, L111, L112: length of magnetic circuit

LP11, LP12, LP21, LP 22: wiring

MP11, MP12, MP 2: magnetic circuit

P11, P12, P21, P22: end part

R11, R12, R21, R22: resistance (RC)

S11, S12, S21, S22, S111, S112: noodle

Tr11, Tr12, Tr13, Tr14, Tr21, Tr22, Tr23, Tr24, Tr31, Tr32, T r33, Tr 34: transistor with a metal gate electrode

Claims

1. A drive unit, in which there are an actuator, a primary gear and a secondary gear,

wherein the actuator has:

two rotors having rotating shafts parallel to each other and magnetized by different magnetic poles in a circumferential direction;

two yokes arranged in opposite directions for magnetically coupling the rotors to each other and forming a closed magnetic path together with the two rotors; and

two coils provided on each of the two yokes to excite each of the two yokes,

each of the rotors is sandwiched by two yokes magnetically coupled to the rotor in a direction perpendicular to a rotation axis of the rotor,

an end portion of one of the two yokes and an end portion of the other yoke sandwich each of the rotors,

the main gear rotates around a rotation axis parallel to the rotation axis of the rotor; and

the auxiliary gear is meshed with the main gear, is respectively arranged on each rotor and rotates by taking the rotating shaft of the rotor as the center,

the main gear is provided with a driving pin,

the two coils are energized simultaneously.

2. The drive unit of claim 1,

the magnetic path length between the end of each of the two yokes on the coil side of the surface facing the rotor and the end of the coil on the surface facing the rotor is equal.

3. The drive unit according to claim 1 or 2,

the two coils are formed of one winding, and each of the two yokes is excited in a circumferential direction of the magnetic circuit.

4. The drive unit according to claim 1 or 2,

each of the two coils is formed by an electrically separate winding.

5. A focal plane shutter, comprising:

a bottom plate having an opening;

a blade member for opening and closing the opening;

a driving part that drives the blade part by rotating; and

an actuator that rotates the drive member,

the actuator has:

two coils provided on each of the two yokes to excite each of the two yokes,

the drive member has:

the two coils are energized simultaneously.

6. The focal plane shutter of claim 5,

7. The focal plane shutter according to claim 5 or 6,

8. The focal plane shutter according to claim 5 or 6,

each of the two coils is formed by an electrically separate winding.

9. A focal plane shutter system, having:

the focal plane shutter of any one of claims 5 to 8; and

and a shutter control unit for supplying power to the two coils and controlling the operation of the blade member.

10. The focal plane shutter system of claim 9,

the shutter control unit includes:

a drive circuit for driving the blade member;

a control circuit for controlling the drive circuit; and

the drive circuit includes: a switching circuit for switching the direction of current flowing through the two coils; and a voltage adjusting circuit for adjusting the magnitude of the voltage applied to the two coils.

11. A photographing apparatus, wherein,

having a focal plane shutter as claimed in any one of claims 5 to 8.

12. An electronic device, wherein,

having a focal plane shutter as claimed in any one of claims 5 to 8.