JP2002051524A - Motor, light quantity adjusting device, and lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical motor capable of attaining high output, and slimness, especially in the radial direction. SOLUTION: This cylindrical motor comprises a magnet which is formed into a cylindrical shape and at least, of which an outer periphery is divided in the circumferential direction and polarized alternately for different poles, a first bobbin wound with a coil, a second bobbin wound with a coil, a first outer pole energized by the coil wound around the first bobbin and facing an outer periphery of one end of the magnet, a hollow and roughly-cylindrical first inner pole facing the inner periphery of the magnet, a second outer pole magnetized by the coil wound around the second bobbin and facing an outer periphery of the other end of the magnet, and a hollow and roughly-cylindrical second inner polar part facing the inner periphery of the magnet. The magnet is formed with a hollow fitting part fitted so as to be slidable on a fitting member provided on the first or second inner pole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-compact motor, a light amount adjusting device using the motor, and a lens barrel.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional small cylindrical step motor. A stator coil 105 is wound concentrically around the bobbin 101, and the bobbin 101 is sandwiched and fixed in the axial direction by two stator yokes 106. 106a and 106b are alternately arranged, and a stator 102 is formed in the case 103 by fixing a stator yoke 106 integral with the stator teeth 106a or 106b.

[0003] One of the two cases 103 has a flange 115
And the bearing 108 are fixed, and the other bearing 108 is fixed to the other case 103. The rotor 109 includes a rotor magnet 111 fixed to a rotor shaft 110, and the rotor magnet 111 is
6a and a radial gap. The rotor shaft 110 is rotatably supported between the two bearings 108.

[0004] However, the conventional small step motor shown in FIG.
01, the stator coil 105 and the stator yoke 106 are arranged concentrically, so that there is a disadvantage that the outer dimensions of the motor become large. Also, the stator coil 10
As shown in FIG. 9, the magnetic flux generated by energizing 5 mainly passes through end face 106a1 of stator teeth 106a and end face 106b1 of stator teeth 106b, and thus does not effectively act on rotor magnet 111, so that the output of the motor does not increase. There are drawbacks.

[0005] The present applicant has proposed a motor in which such a problem is solved in JP-A-09-331666. This proposed motor forms a cylindrical rotor having permanent magnets alternately magnetized to different poles equally divided in the circumferential direction,
A first coil, a rotor, and a second coil are sequentially arranged in the axial direction of the rotor, and a first outer magnetic pole and a first inner magnetic pole excited by the first coil are formed on the outer peripheral surface and the inner peripheral surface of the rotor. , And the second outer magnetic pole and the second inner magnetic pole excited by the second coil are configured to face the outer peripheral surface and the inner peripheral surface of the rotor. It is taken out from inside the cylindrical permanent magnet.

[0006] The motor having such a configuration can have a high output and a small external dimension of the motor, but it is desired to facilitate the joining of the rotor shaft and the permanent magnet. Further, in the above configuration, the distance between the first outer magnetic pole and the first inner magnetic pole and the distance between the second outer magnetic pole and the second inner magnetic pole can be reduced by thinning the magnet. The magnetic resistance can be reduced. According to this, the current flowing through the first coil and the second coil can generate a large amount of magnetic flux with a small amount of current.

[0007]

However, since the motor of the type described in the above-mentioned Japanese Patent Application Laid-Open No. 09-331666 has a solid cylindrical shape, it must be parallel to the optical axis in the lens barrel of the camera. When it is used to drive the aperture blades, shutter, lens, etc., the radius of the lens barrel is the value obtained by adding the diameter of the motor to the radius of the lens and the radius of the aperture opening. Was not small enough.

FIG. 10 shows the situation. Assuming that the motor is M, the lens barrel base or the light amount adjusting device is 300, the opening is 301, the diameter of the motor M is D1, the diameter of the opening 301 is D2, and the diameter of the lens barrel base 300 is D3, the diameter of the lens barrel base 300 D3 is at least (2 × D1 + D2) or more. For such applications, there has been a demand for a donut-shaped motor having a small radial thickness. It is also desired to make the lens barrel device or the light amount adjusting device compact.

[0009] Further, those in which a diaphragm blade is driven by a hollow donut-shaped motor are proposed in, for example, JP-A-53-37745 and JP-A-57-166847. Since the coil is wound around the outside of the hollow magnet, the thickness of the coil, the thickness of the magnet and the thickness of the stator are all added to the thickness in the radial direction. It was not enough for a motor.

[0010] Further, a lens driving device is disclosed in
172727 and the like. Because the center axis of the coil is arranged in the direction toward the center of the optical axis of the lens barrel, the coil shape becomes complicated and the assembly becomes complicated, the number of parts increases, and the device itself does not become compact. There is a problem that the number of coils increases and the cost increases.

An object of the present invention is, firstly, to provide a cylindrical motor having a high output and particularly thin in the radial direction.

The second object of the present invention is to provide a compact (small diameter)
To provide a light amount adjusting device.

The third object of the present invention is to provide a compact (small diameter)
A lens barrel of the present invention.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention firstly forms a cylindrical shape, and at least the outer peripheral surface is divided in the circumferential direction and alternately magnetized to different poles. Magnet, a first bobbin wound with a coil, a second bobbin wound with a coil,
A first outer magnetic pole portion which is excited by a coil wound around the bobbin and faces an outer peripheral surface on one end side of the magnet;
A first inner magnetic pole portion which is opposed to the inner peripheral surface of the magnet and has a substantially hollow cylindrical shape and a second coil which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet; An outer magnetic pole portion and a second inner magnetic pole portion having a hollow substantially cylindrical shape facing the inner peripheral surface of the magnet, wherein the magnet slides with a fitting member provided on the first or second inner magnetic pole portion. It is characterized by having a hollow fitting part which fits as possible.

[0015] In the above configuration, the magnet has a hollow fitting portion which is slidably fitted with a fitting member provided on the first or second inner magnetic pole portion, thereby forming a hollow cylindrical motor. Since the magnetic flux generated by the coil crosses the magnet between the outer magnetic pole and the inner magnetic pole, it works effectively, so that the motor has a high output and the thickness dimension in the radial direction is the thickness of the magnet and the inner magnetic pole. Since it is almost determined by the sum of the three outer magnetic poles, the radial dimension is thinner than that of a type in which a coil is arranged outside a normal magnet or a type of motor described in JP-A-09-331666 or the like. A cylindrical motor can be provided. The diameter D1 of a motor of the type described in JP-A-09-331666 or the like is at least (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 or more.

When this is mounted on the barrel base plate, as described above, the diameter of the barrel base plate 300 is (2 × D1 + D
2) (magnet thickness + inner magnetic pole +
(Outside magnetic pole) × 4 + D2 or more. In the case of using the motor having the configuration of the present invention, it is sufficient to use a lens barrel base plate having a dimension of approximately (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2. In other words, by adopting the above configuration, it is possible to achieve a high-output motor with a thin dough in the radial direction, in which the hollow portion can be used for another function.

[0017] In order to solve the above problems, the present invention provides a second method.
A magnet formed in a cylindrical shape and having at least an outer peripheral surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin around which the coil is wound, and a first bobbin around which the coil is wound A first bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface on one end side of the magnet, and a hollow hollow cylinder which faces an inner circumferential surface of the magnet A first inner pole portion of the shape;
A second outer magnetic pole portion which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and a hollow hollow cylindrical second inner surface which faces the inner peripheral surface of the magnet A motor provided with a magnetic pole portion, an opening disposed in the hollow portion of the first inner magnetic pole portion or the hollow portion of the second inner magnetic pole portion, connecting means for connecting to the magnet and rotating, and A light amount adjusting device including an aperture blade driven by an output to adjust an opening amount of the opening.

In the above configuration, the magnet has a hollow fitting portion which is slidably fitted with a fitting member provided on the first or second inner magnetic pole portion, thereby forming a hollow cylindrical motor. In addition, the magnetic flux generated by the coil crosses the magnet between the outer and inner magnetic poles and acts effectively, so that the motor has a high output and the thickness dimension in the radial direction is the thickness of the magnet and the inner magnetic pole. And the outer magnetic poles, so that the radial dimension is smaller than that of a type in which a coil is disposed outside a normal magnet or a type of motor described in JP-A-09-331666 or the like. The result is a thin cylindrical motor. The diameter D1 of a motor of the type described in JP-A-09-331666 or the like is at least (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 or more. When this is mounted on the light amount adjusting device, the diameter of the light amount adjusting device 300 becomes (2 × D1 + D2) as described above, and the diameter of the magnet is (magnet thickness + inner magnetic pole + outer magnetic pole) × 4 + D2 or more. Become. When using the motor having the configuration of the present invention, the hollow portion can be used as an optical path (magnet thickness + inner magnetic pole + outer magnetic pole).
A light amount adjusting device having a size of × 2 + D2 is sufficient.

[0019] In order to solve the above problems, the present invention provides a third method.
A magnet formed in a cylindrical shape and having at least an outer peripheral surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin around which the coil is wound, and a first bobbin around which the coil is wound A first bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface on one end side of the magnet, and a hollow hollow cylinder which faces an inner circumferential surface of the magnet A first inner pole portion of the shape;
A second outer magnetic pole portion which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and a hollow hollow cylindrical second inner surface which faces the inner peripheral surface of the magnet A motor having a magnetic pole portion, optical means having an optical axis in the hollow portion of the first inner magnetic pole portion or the hollow portion of the second inner magnetic pole portion, and the optical device being connected to the magnet and rotating, and And a moving means for moving the lens in the optical axis direction.

In the above configuration, the magnet has a hollow fitting portion which is slidably fitted with a fitting member provided on the first or second inner magnetic pole portion, thereby forming a hollow cylindrical motor. Since the magnetic flux generated by the coil crosses the magnet between the outer magnetic pole and the inner magnetic pole, it works effectively, so that the motor has a high output and the thickness dimension in the radial direction is the thickness of the magnet and the inner magnetic pole. Since it is almost determined by the sum of the three outer magnetic poles, the radial dimension is thinner than that of a type in which a coil is arranged outside a normal magnet or a type of motor described in JP-A-09-331666 or the like. It becomes a cylindrical motor. The diameter D1 of a motor of the type described in JP-A-09-331666 is at least (magnet thickness +
Inner magnetic pole + outer magnetic pole) x 2 or more. When this is mounted on the lens barrel device, as described above, the lens barrel device 30 is used.
Since the diameter of 0 is D3 becomes (2 × D1 + D2), (magnet thickness + inner magnetic pole + outer magnetic pole) × 4 + D
It will be two or more dimensions. When the motor having the configuration of the present invention is used, the hollow portion can be used as an optical path, and a lens barrel device having a size of approximately (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2 can be used.

[0021]

(Embodiment 1) FIGS. 1 to 6 show an embodiment of the present invention, in which FIG. 1 is an exploded perspective view of a light amount adjusting device, and FIG. 2 is a sectional view of the light amount adjusting device. 3 to 6
FIG. 3 is a cross-sectional view showing the relationship between members of a motor part of the motor.

In FIG. 1 to FIG. 6, reference numeral 1 denotes a cylindrical magnet constituting a rotor. The magnet 1, which is a rotor, has its outer peripheral surface divided into n parts in the circumferential direction. Then> the magnetized portions 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1 in which the S pole and the N pole are alternately magnetized.
h, 1i, 1j, 1k, 1m, 1n, 1p, 1q, 1r
Then, the magnetized portions 1a, 1c, 1e, 1g, 1i,
1k, 1n, 1q are magnetized to the S pole, and the magnetized portions 1b, 1
d, 1f, 1h, 1j, 1m, 1p, 1r are N-pole magnetized. The magnet 1 is made of a plastic magnet material formed by injection molding. Thus, the thickness of the cylindrical shape in the radial direction can be made very thin. When the inner circumferential surface of the magnet 1 has a weaker magnetization distribution than that of the outer circumferential surface or is not magnetized at all or the pole opposite to the outer circumferential surface, that is, the outer circumferential surface is the S pole, the inner circumferential surface in that range is It is magnetized to the N pole.

Further, the magnet 1 is provided with a rib portion 1s having a small inner diameter at a central portion in the axial direction. A pin 1 is attached to the rib portion 1s.
t is provided.

Reference numeral 2 denotes a cylindrical coil. The coil 2 is arranged concentrically with the magnet 1 and at a position where the magnet 1 is overlapped in the axial direction, and the outer diameter of the coil 2 is equal to the outer diameter of the magnet 1. It is almost the same size as.

Reference numeral 18 denotes a first stator made of a soft magnetic material.
The first stator includes an outer cylinder and a hollow column-shaped inner cylinder. The outer cylinder of the first stator 18 has (N / 2-1), that is, eight first outer magnetic poles 18a, 18b, 18c, 18d, 1 opposed to the outer peripheral surface of the magnet 1 at its tip.
8e, 18f, 18g, and 18h. Further, the hollow cylinder-shaped inner cylinder has (N / 2-1) or eight first inner magnetic poles 18i, 18j, 18k, 18m, 18n, and 18p opposed to the inner peripheral surface of the magnet 1 at its tip. , 1
8q, 18r are formed. Outer magnetic poles 18a, 18b, 18c, 18d, 18e, 18 of the first stator
f, 18g, 18h and the first inner magnetic poles 18i, 18j,
The magnets 18k, 18m, 18n, 18p, 18q, and 18r are formed so as to have the same phase with respect to each other with the magnet 1 interposed therebetween. At an integral multiple of 360 / <n / 2> degrees, that is, an integer multiple of 45 degrees.

Reference numeral 4 denotes a cylindrical coil. The coil 4 is arranged concentrically with the magnet 1 and positioned so as to sandwich the magnet 1 with the coil 2 in the axial direction. The dimensions are almost the same as the outer diameter.

Reference numeral 19 denotes a second stator made of a soft magnetic material.
The second stator includes an outer cylinder and an inner cylinder having a hollow column shape. The outer cylinder of the second stator 19 has (N / 2-1), that is, eight second outer magnetic poles 19a, 19b, 19c, 19d, 1 opposed to the outer peripheral surface of the magnet 1 at its tip.
9e, 19f, 19g, and 19h. The hollow cylinder-shaped inner cylinder has (N / 2-1), that is, eight second inner magnetic poles 19i, 19j, 19k, 19m, 19n, and 19p opposed to the inner peripheral surface of the magnet 1 at its tip. , 1
9q and 19r are formed. Outer magnetic poles 19a, 19b, 19c, 19d, 19e, 19 of the second stator
f, 19g, 19h and the second inner magnetic poles 19i, 19j,
The magnets 19k, 19m, 19n, 19p, 19q, and 19r are formed so as to have the same phase with the magnet 1 interposed therebetween. At an integral multiple of 360 / <n / 2> degrees, that is, an integer multiple of 45 degrees.

Outer magnetic poles 18a, 18 of the first stator 18
b, 18c, 18d, 18e, 18f, 18g, 18h
And the outer magnetic poles 19a, 19b of the second stator 19,
Reference numerals 19c, 19d, 19e, 19f, 19g, and 19h each include a cutout hole and teeth extending in a direction parallel to the axis. This configuration allows the formation of magnetic poles while minimizing the diameter of the motor. In other words, if the outer magnetic pole is formed with irregularities extending in the radial direction, the diameter of the motor will increase accordingly, but in this embodiment, the outer magnetic pole is constituted by a notch hole and teeth extending in a direction parallel to the axis. The diameter of the motor can be minimized. In the first stator 18 and the second stator 19, the outer magnetic poles 18a, 18b, 18c, 18d, 18e, 18 each formed of a notch and a tooth extending in a direction parallel to the axis.
f, 18g, 18h and the outer magnetic poles 19a, 19b, 19c, 19d, 19e, 19f,
19g and 19h are arranged facing each other, but the first
Phase of the second and third stators is 180 / n
Degrees, that is, 11.25 degrees.

Outer magnetic poles 18a, 18 of the first stator 18
b, 18c, 18d, 18e, 18f, 18g, 18h
And 18i, 18j, 18 to be the first inner magnetic poles
k, 18m, 18n, 18p, 18q, and 18r are formed so as to sandwich one end of the magnet 1 in opposition to the outer peripheral surface and the inner peripheral surface at one end of the magnet 1.

Outer magnetic poles 19a, 19 of the second stator 19
b, 19c, 19d, 19e, 19f, 19g, 19h
And 19i, 19j, 19 to be the second inner magnetic poles
k, 19m, 19n, 19p, 19q, and 19r are formed so as to sandwich the other end of the magnet 1 in opposition to the outer peripheral surface and the inner peripheral surface of the other end of the magnet 1.

The coil 2 is provided between the outer cylinder and the inner cylinder of the first stator 18, and when the coil 2 is energized, the outer magnetic poles 18a, 18b, 18 of the first stator 18 are provided.
c, 18d, 18e, 18f, 18g, 18h and inner magnetic poles 18i, 18j, 18k, 18m, 18n, 18
p, 18q and 18r are excited.

The coil 4 is provided between the outer cylinder and the inner cylinder of the second stator 19, and when the coil 4 is energized, the outer magnetic poles 19a, 19b, 19 of the second stator 19 are provided.
c, 19d, 19e, 19f, 19g, 19h and inner magnetic poles 19i, 19j, 19k, 19m, 19n, 19
p, 19q, and 19r are excited.

Therefore, the magnetic flux generated by the coil 2 is generated by the outer magnetic poles 18a, 18b, 18c, 18d, 18e, 18
f, 18g, 18h and inner magnetic poles 18i, 18j, 1
8k, 18m, 18n, 18p, 18q, and 18r, which cross the magnet 1, which is a rotor, effectively acts on the magnet, which is a rotor, and the magnetic flux generated by the coil 3 causes the outer magnetic poles 19a, 19b, 19c, 19d, 1
9e, 19f, 19g, 19h and inner magnetic poles 19i,
19j, 19k, 19m, 19n, 19p, 19q, 1
9r, it crosses the magnet 1, which is the rotor between
It effectively acts on the magnet which is the rotor and increases the output of the motor.

The magnet 1 is made of a plastic magnet material formed by injection molding as described above, so that the thickness of the cylindrical shape in the radial direction can be made extremely thin.

Therefore, the outer magnetic pole 18 of the first stator 18
a, 18b, 18c, 18d, 18e, 18f, 18
g, 18h and inner magnetic poles 18i, 18j, 18k, 18
m, 18n, 18p, 18q, and 18r can be made very small, and the magnetic resistance of the magnetic circuit formed by the coil 4 and the first stator can be made small. Similarly, the outer magnetic poles 19a, 19b, 19c,
19d, 19e, 19f, 19g, 19h and inner magnetic pole 1
9i, 19j, 19k, 19m, 19n, 19p, 19
q, 19r, the distance between the coil 5 and the second
The magnetic resistance of the magnetic circuit formed by the stator can be reduced. As a result, a large amount of magnetic flux can be generated with a small amount of current, increasing the output of the motor, reducing power consumption,
The miniaturization of the coil is achieved.

Reference numeral 20 denotes a connecting ring made of a nonmagnetic material, for example, a plastic material, stainless steel for spring, phosphor bronze for spring, or the like.

The connecting ring 20 includes the first stator 18, the second
Of their phases 180 / n degrees or 1
It is for holding and fixing at a position shifted by 1.25 degrees and separated by a certain distance at the tip.

That is, the outer magnetic poles 18a, 1 of the first stator 18
8b, 18c, 18d, 18e, 18f, 18g, 18
h and the outer magnetic poles 19 a, 1 of the second stator 19.
9b, 19c, 19d, 19e, 19f, 19g, 19
h 1 are arranged so as to be spaced apart from each other in a direction parallel to the axis by a distance of 180 / n degrees, that is, 11.25 degrees with respect to the rotational position.

Since the connecting ring is made of a non-magnetic material, the first stator 18 and the second stator 19 can be separated from each other on a magnetic circuit, so that they do not influence each other, and the performance of the motor is stabilized.

Reference numeral 21 denotes a first hollow fitting member, which is fixed to the inner cylinder of the first stator 18 and has projections 21a, 21b, 21
c, 21d, 21e, 21f, 21g, 21h are the inner magnetic poles 18i, 18j, 18k, 18m, 18n, 18p,
The protrusions 18 are slidably fitted to the inner peripheral portion 1u of the magnet 1 from between 18q and 18r. Also, the first hollow fitting member 2
1 has a hollow structure.

Reference numeral 22 denotes a second hollow fitting member, which is fixed to the inner cylinder of the second stator 19 and has projections 22a, 22b, 22
c, 22d, 22e, 22f, 22g, 22h are the inner magnetic poles 19i, 19j, 19k, 19m, 19n, 19p,
The projecting magnet is slidably fitted to the inner peripheral portion 1v of the magnet 1 from between 19q and 19r. The 21st hollow fitting member 22 has a hollow structure.

The rib 1s of the magnet 1 is provided between the first fitting member 21 and the second fitting member 22 in the thrust direction.
And is regulated by. With such a structure, the magnet 1 is rotatably held.

Reference numeral 30 denotes a main plate, and reference numeral 31 denotes an output ring rotatably attached to the fitting portion 30A of the main plate. The main plate has an opening 30D.

The output ring 31 has a hole 31a fitted to the pin 1t of the magnet 1 and rotates with the rotation of the magnet 1.
This will be described later.

Reference numerals 32 and 33 denote aperture blades, in which dowels 32A and 33A are slidably fitted in cam grooves 30A and 30B formed in the base plate 30, and holes 32B and 33B are formed in the output ring 3A.
The first dowels 31B and 31C are rotatably fitted. By rotating the output ring 31, the aperture blades 32 and 33 are configured to change their aperture amounts while rotating about the optical axis. Reference numeral 34 denotes a blade holding plate, which holds a space in which the diaphragm blades 32 and 33 can move between itself and the ground plate 30 and is attached to the inner diameter of the first stator 18.

In the above configuration, a hollow cylindrical motor is provided by providing a hollow fitting portion slidably fitted to the magnet and a fitting member provided on the first or second inner magnetic pole portion. In addition, the magnetic flux generated by the coil crosses the magnet between the outer and inner magnetic poles and acts effectively, so that the motor has a high output and the thickness dimension in the radial direction is the thickness of the magnet and the inner magnetic pole. And the outer magnetic poles, so that the radial dimension is smaller than that of a type in which a coil is disposed outside a normal magnet or a type of motor described in JP-A-09-331666 or the like. The result is a thin cylindrical motor.

The diameter D1 of the motor of the type described in JP-A-09-331666 is at least (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 or more. When this is mounted on the light amount adjusting device, the diameter of the light amount adjusting device 300 becomes (2 × D1 + D2) as described above, so that the diameter of the light amount adjusting device 300 becomes (magnet thickness + inner magnetic pole + outer magnetic pole) × 4 + D2 or more. turn into. When the motor having the configuration of the present invention is used in the light amount adjusting device, the hollow portion can be arranged as an optical path, so that a light amount adjusting device having a size of approximately (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2 is sufficient.

FIG. 2 is a sectional view of the step motor, and FIG.
(a), (b), FIG. 4 (a), (b), FIG. 5 (a), (b), FIG.
3 (a), 4 (a), 5 (a) and 6 of FIGS. 3 (a) and 4 (b)
FIG. 3A is a sectional view taken along line AA of FIG. 2, and FIGS. 3B, 4B, 5B, and 6B are taken along line BB of FIG. FIG. FIGS. 3A and 3B are cross-sectional views at the same time, and FIGS. 4A and 4B are cross-sectional views at the same time.
(a) and (b) are cross-sectional views at the same time, and FIG. 6 (a) and (b)
Are cross-sectional views at the same time. In FIGS. 3, 4, 5, and 6, components unnecessary for the description of the driving operation of the motor, such as the aperture blade and the output ring, are omitted.

Next, the operation of the step motor will be described. FIG.
The states (a) and (b) correspond to the first outer magnetic poles 18a, 18b, 18c, 18d, 18e, 18f,
18g and 18h are N poles, and the first inner magnetic poles 18i and 18
j, 18k, 18m, 18n, 18p, 18q, 18r
, The second outer magnetic pole 19a of the second stator 19,
19b, 19c, 19d, 19e, 19f, 19g, 1
9h is the S pole, the second inner magnetic poles 19i, 19j, 19k,
In this state, the coils 2 and 4 are energized so that 19m, 19n, 19p, 19q, and 19r become N poles.

The direction of energization to the coil 4 is switched from the state shown in FIGS. 3A and 3B to the first outer magnetic poles 18a, 18b, 18c, 18d, 18e, 18f, 1 of the first stator 18.
8g, 18h are N poles, and the first inner magnetic poles 18i, 18
j, 18k, 18m, 18n, 18p, 18q, 18r
Is the south pole, and the second outer magnetic pole 19 of the second stator 19 is
a, 19b, 19c, 19d, 19e, 19f, 19
g, 19h as N poles and second inner magnetic poles 19i, 19j,
19k, 19m, 19n, 19p, 19q, 19r
When the poles are excited, the magnet 1, which is a rotor, rotates 11.25 degrees counterclockwise to reach the state shown in FIGS. 4 (a) and 4 (b).

Next, the power supply to the coil 2 is reversed, and the outer magnetic poles 18a, 18b, 18c, 18 of the first stator 18 are turned off.
d, 18e, 18f, 18g and 18h are S poles,
First inner magnetic poles 18i, 18
j, 18k, 18m, 18n, 18p, 18q, 18r
Is the N pole, and the outer magnetic poles 19a, 1 of the second stator 19 are
9b, 19c, 19d, 19e, 19f, 19g, 19
h is the N pole, and the second inner magnetic poles 19i, 19j, 19
When k, 19m, 19n, 19p, 19q, and 19r are excited to the S pole, the magnet 1, which is the rotor, further rotates 11.25 degrees counterclockwise to the state shown in FIGS. 5A and 5B. .

Next, the power supply to the coil 4 is reversed, and the outer magnetic poles 18a, 18b, 18c, 18d,
18e, 18f, 18g, 18h are S poles, and the first inner magnetic poles 18i, 18j,
18k, 18m, 18n, 18p, 18q, 18r
And the outer magnetic poles 19 a and 19 of the second stator 19.
b, 19c, 19d, 19e, 19f, 19g, 19h
Is the S pole, and the second inner magnetic poles 19i, 19j, 19k,
When the magnets 19m, 19n, 19p, 19q, and 19r are excited to the N pole, the magnet 1 as the rotor further rotates counterclockwise by 11.25 degrees to reach the state shown in FIGS. 6A and 6B.

Thereafter, by sequentially switching the energizing direction to the coil 2 and the coil 4, the magnet 1, which is a rotor, rotates to a position corresponding to the energizing phase.

Since the output ring 31 has a structure in which the hole 31a is fitted into the pin 1t of the magnet 1 and rotates with the rotation of the magnet 1, the output ring 31 is sequentially rotated by sequentially switching the energizing direction to the coil 2 and the coil 4. Then, the aperture blades 32 and 33 are displaced by an amount corresponding to the rotational position to adjust the opening amount.

Here, a description will be given of the fact that the actuator having such a configuration has an optimum configuration for miniaturization.

In the above configuration, a hollow cylindrical motor is provided by providing a hollow fitting portion slidably fitted to the magnet and a fitting member provided on the first or second inner magnetic pole portion. In addition, the magnetic flux generated by the coil crosses the magnet between the outer magnetic pole and the inner magnetic pole, and works effectively, so that the motor has a high output. Further, since the thickness dimension in the radial direction is substantially determined by the total of the thickness of the magnet and the inner magnetic pole and the outer magnetic pole, a type in which a coil is arranged outside a normal magnet and the above-mentioned Japanese Patent Application Laid-Open No. 09-331666 are described. This is a cylindrical motor having a smaller radial dimension than that of the conventional type. In particular, since the outer magnetic pole is formed by the notch hole and the tooth extending in the direction parallel to the axis, the diameter of the motor can be minimized. In other words, if the outer magnetic pole is formed with irregularities extending in the radial direction, the diameter of the motor will increase accordingly, but in this embodiment, the outer magnetic pole is constituted by a notch hole and teeth extending in a direction parallel to the axis. The diameter of the motor can be minimized.

When the motor having the structure of the present invention is used in a light amount adjusting device, the hollow portion can be arranged as an optical path, so that a light amount adjusting device having a size of approximately (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2 is sufficient. Become. Moreover, the outer magnetic pole is constituted by a notch hole and a tooth extending in a direction parallel to the axis, so that the outer magnetic pole is very compact.

(Embodiment 2) FIG. 7 shows Embodiment 2. This is an example in which the motor is used as a drive source for a lens barrel. 50
Is a helicoid ground plate fixed to the first stator 18. Reference numeral 51 denotes a lens holder which is a male helicoid part.
The male helicoid part 51a is slidably fitted with the female helicoid part 50a of the helicoid base plate 50, and the lens holder 51 rotates to move in the axial direction.

A lens 52 is fixed to the lens holder 51, and the position of the lens holder 51 in the optical axis direction is displaced by rotation. The lens holder 51 has a groove 50b
The groove 50b is fitted with the pin 1s of the magnet 1 and rotates integrally with the magnet 1 in the rotational direction, so that relative movement in the axial direction is possible. That is, when the magnet 1 rotates, the lens is displaced in the optical axis direction. Since the optical axis and optical path of the lens 1 are arranged in the hollow portion of the hollow motor, a compact lens barrel device can be obtained.

That is, in the above configuration, the magnet is provided with a hollow fitting portion slidably fitted with a fitting member provided on the first or second inner magnetic pole portion. Since the magnetic flux generated by the coil crosses the magnet between the outer magnetic pole and the inner magnetic pole and acts effectively, the motor has a high output, and the thickness dimension in the radial direction is the thickness of the magnet and the inner magnetic pole. And the outer magnetic poles, so that the radial dimension is smaller than that of a type in which a coil is disposed outside a normal magnet or a type of motor described in JP-A-09-331666 or the like. The result is a thin cylindrical motor.

[0061] The diameter D1 of the motor of the type described in JP-A-09-331666 or the like is at least (magnet thickness + inner magnetic pole + outer magnetic pole) x 2 or more. When this is mounted on the lens barrel device, the diameter D3 of the lens barrel device 300 becomes (2 × D1 + D2) as described above (magnet thickness + inner magnetic pole + outer magnetic pole) × 4 +
The dimensions will be larger than D2. When the motor having the configuration of the present invention is used, the hollow portion can be used as an optical path and can be roughly (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2
In this case, it is sufficient to use a lens barrel device having the following dimensions.

[0062]

As described above in detail, according to the present invention,
A magnet formed in a cylindrical shape and having at least an outer peripheral surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin around which a coil is wound, and a second bobbin around which a coil is wound A bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface on one end side of the magnet, and a hollow substantially cylindrical shape which faces an inner circumferential surface of the magnet and A first inner magnetic pole portion, a second outer magnetic pole portion which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and a hollow which opposes the inner peripheral surface of the magnet; A substantially cylindrical second inner magnetic pole portion, wherein the magnet is provided in the first magnetic pole portion;
Alternatively, a motor having a hollow fitting portion provided with a hollow fitting portion slidably fitted with a fitting member provided on the second inner magnetic pole portion can be used as a motor having a hollow cylindrical shape. Since the generated magnetic flux crosses the magnet between the outer magnetic pole and the inner magnetic pole, it works effectively, so that the motor has a high output. The thickness dimension in the radial direction is substantially determined by the total of the thickness of the magnet, the inner magnetic pole, and the outer magnetic pole, and is described in, for example, a type in which a coil is arranged outside a normal magnet, and the above-mentioned JP-A-09-331666. Thus, it is possible to provide a cylindrical motor having a smaller radial dimension than that of the conventional motor.

[0063] The diameter D1 of the motor of the type described in JP-A-09-331666 or the like is at least (magnet thickness + inner magnetic pole + outer magnetic pole) x 2 or more. When this is mounted on the barrel base plate, the diameter D3 of the barrel base plate 300 becomes (2 × D1 + D2) as described above (magnet thickness + inner magnetic pole + outer magnetic pole) × 4 +
The dimensions will be larger than D2. In the case of using the motor having the configuration of the present invention, it is sufficient to use a lens barrel base plate having a dimension of approximately (magnet thickness + inner magnetic pole + outer magnetic pole) × 2 + D2.
In other words, by adopting the above configuration, it is possible to achieve a high-output motor with a thin dough in the radial direction, in which the hollow portion can be used for another function.

Further, by using such a motor as a driving source of a light amount adjusting device or a lens driving device, a hollow portion of the motor is disposed so as to be an opening or an optical path of a lens, thereby providing a compact light amount adjusting device or a lens barrel. Become.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a light amount adjusting device according to the present invention.

FIG. 2 is a sectional view of the light amount adjusting device shown in FIG.

FIG. 3 is a cross-sectional view showing a relationship between members of a motor part.

FIG. 4 is a cross-sectional view showing a relationship between members of a motor portion.

FIG. 5 is a cross-sectional view showing a relationship between members of a motor part.

FIG. 6 is a cross-sectional view showing a relationship between members of a motor portion.

FIG. 7 is a sectional view of a lens barrel.

FIG. 8 is a sectional view of a conventional step motor.

FIG. 9 is a cross-sectional view showing a state of a stator of a conventional step motor.

FIG. 10 is a plan view of a lens barrel base plate or a light amount adjusting device when a conventional step motor is arranged.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 magnet 2 coil 4 coil 18 first stator 19 second stator 20 connecting ring 21 first hollow fitting member 22 second hollow fitting member 30 base plate 31 output ring 32 aperture blade 33 aperture blade 34 blade holding plate 50 Helicoid base plate 51 Lens holder 52 Lens

Claims (3)

[Claims] 1. A magnet formed in a cylindrical shape and having at least an outer peripheral surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin on which a coil is wound, and a coil wound on the first bobbin. A second bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface at one end of the magnet, and a first outer magnetic pole portion which faces an inner circumferential surface of the magnet. A first inner magnetic pole part having a substantially hollow cylindrical shape, a second outer magnetic pole part which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and an inner periphery of the magnet A hollow inner cylindrical portion facing the surface and having a hollow substantially cylindrical shape, wherein the magnet is slidably fitted with a fitting member provided on the first or second inner magnetic pole portion; A motor comprising: 2. A magnet formed in a cylindrical shape and having at least an outer peripheral surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin on which a coil is wound, and a coil wound on the first bobbin. A second bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface at one end of the magnet, and a first outer magnetic pole portion which faces an inner circumferential surface of the magnet. A first inner magnetic pole part having a substantially hollow cylindrical shape, a second outer magnetic pole part which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and an inner periphery of the magnet A motor having a second inner magnetic pole portion having a hollow substantially cylindrical shape facing a surface, an opening disposed in the hollow portion of the first inner magnetic pole portion or the hollow portion of the second inner magnetic pole portion, and the magnet; Connecting means for connecting and rotating Light quantity adjusting device, characterized in that it comprises a diaphragm blade that is driven by the output of the connecting means for adjusting the opening amount of the opening. 3. A magnet formed in a cylindrical shape and having at least an outer circumferential surface divided in a circumferential direction and alternately magnetized to different poles, a first bobbin on which a coil is wound, and a coil wound on the first bobbin. A second bobbin, a first outer magnetic pole portion which is excited by a coil wound around the first bobbin and faces an outer circumferential surface at one end of the magnet, and a first outer magnetic pole portion which faces an inner circumferential surface of the magnet. A first inner magnetic pole part having a substantially hollow cylindrical shape, a second outer magnetic pole part which is excited by a coil wound around the second bobbin and faces the outer peripheral surface on the other end side of the magnet, and an inner periphery of the magnet A motor having a second inner magnetic pole portion having a hollow cylindrical shape facing the surface, optical means having an optical axis in the hollow portion of the first inner magnetic pole portion or the hollow portion of the second inner magnetic pole portion, and It rotates in connection with the magnet and A lens barrel characterized by comprising a moving means for moving said optical means in the optical axis direction.