JP2001350172A - Light quantity controller and optical apparatus incorporating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light quantity controller which is made thin, which can be easily built into a small-sized optical apparatus, and also, capable of obtaining an appropriately exposed image by a single electromagnetic driving part by constituting the electromagnetic driving part composed of a conductive coil, a magnet and an diaphragming blade oscillating member, etc., so that the electromagnetic driving part my not project from a base member on which diaphragming blade is arranged and the electromagnetic driving part may be integrally formed with the flat surface of the base member, and to provide an optical device incorporating the light quantity controller. SOLUTION: The magnet 33 having NS pole faces magnetized and divided into two right and left poles is loaded so that the different NS pole faces may be opposed to each other on both sides across the shaft 41 of an arm 31, and the flat conductive coil 34, the arm 31 and the magnet 33 are arranged so that the magnetic field B1 by the magnet 33 and a coil induction magnetic field B2 by the conductive coil 34 may always cross each other in the rotation allowable extents of ϕ1 to ϕ2 of the arm 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount adjusting device in which an electromagnetic driving member is integrally formed with a member constituting a diaphragm mechanism, and an optical device incorporating the light amount adjusting device.

[0002]

2. Description of the Related Art An optical device, for example, a light amount adjusting device including a diaphragm device and a shutter device incorporated in a video camera for adjusting the amount of photographing light. Conventionally, for example, the diaphragm device generally includes an aperture blade and an associated aperture blade. Many include an oscillating member (hereinafter, referred to as an arm) and an electromagnetic drive unit that drives the arm by electromagnetic action. FIG. 9 shows a typical example of such a light amount adjusting device. In this embodiment, an aperture mechanism section 2 including aperture blades and an electromagnetic drive section 3 including a coil, a rotor magnet, and the like are formed separately, and these are combined to constitute one light amount adjusting device 1.

The diaphragm mechanism 2 includes a swingable arm 5,
It is composed of two diaphragm blades 4 that slide alternately in conjunction with the arm 5. The aperture blade 4 is provided with an opening 7 which is cut in a semicircular shape larger than an exposure hole 17 described later in a fully opened state, and an ND filter 18 for suppressing a diffraction phenomenon on the small aperture side is provided in one opening 7. Is provided. One end of each of the two diaphragm blades 4 is fitted to a drive pin 15 provided at each end of the arm 5, and the arm 5 swings about a central axis 16 so that the two diaphragm blades 4 are mounted on the substrate. 6 alternately slide.

The electromagnetic drive unit 3 includes a motor 8 and the motor 8
Is provided, and is fixed to the substrate 6 by the fixture 10. The motor 8 includes a columnar rotor magnet 14 having a shaft 13 disposed thereon, upper and lower coil frames 12 for accommodating the rotor magnet 14, and coils 11 wound around the coil frame 12.

The shaft 13 of the motor 8 formed as described above penetrates through the substrate 6 from below and is connected to the center shaft 16 of the arm 5 of the aperture mechanism 2, and the arm 8 is driven to swing by the rotation of the motor 8. . The swing of the arm 5 changes the amount of overlap between the opening 7 of the two diaphragm blades 4 and the ND filter 18.
The amount of light taken in is adjusted.

[0006] In addition to the above-mentioned light quantity adjusting device, a device having a structure shown in FIG. 10 is known. This is an example of a shutter device, in which two shutter blades 20a and 20b are arranged on a straight line, and exposure holes 27a and 27b are provided at opposing front ends of the shutter blades 20a and 20b, and magnets 21a and 27b are provided at rear end portions. 21b, and the magnet 2
The two diaphragm blades 20a, 20b are opened and closed by electromagnetic drive units 23a, 23b formed by winding coils 22a, 22b around 1a, 21b. The two diaphragm blades 20a and 20b are arranged at positions facing each other as shown in the figure, and a support shaft 24 is linked by a common arm 25 so as to slide in conjunction with each other.
Thus, the exposure holes 27a and 27b of the aperture blades 20a and 20b slide on the exposure hole 26 provided on the substrate in synchronization with each other to adjust the amount of light to be taken into the exposure hole 26 (Japanese Patent Laid-Open No. 58-1983). -54370).

[0007]

However, the conventional light amount adjusting device 1 shown in FIG. 9 has an electromagnetic drive unit 3 independent of the arm 5 for operating the aperture blade 4. . Since the rotor magnet 14 of the electromagnetic drive unit 3 and the arm 5 are joined by the power transmission shaft 13, there is no other way than to incorporate the armature 5 in a state where the armature 5 protrudes from the substrate 6 having the aperture blade 4. This has been a factor that hinders the thinning of the entire light amount adjusting device 1. For this reason, it has been difficult to incorporate them into optical units such as small video cameras and digital cameras. The electromagnetic drive unit 3 must be provided with an exciting coil 11 around a rotor magnet 14. For this purpose, a step of separately manufacturing a coil frame 12 and winding a conductive wire around the coil frame 12 is required. Is required. However, in this step, the number of assembly parts is large, and the number of steps required for the operation is also large. Therefore, there is a problem that mass production is not suitable for mass production.

On the other hand, in the light amount adjusting device shown in FIG. 10, the magnets 21a and 21b are connected to the aperture blades 20a and 20b.
0b, the coil frame 12 and the shaft 13 which are the components in FIG. 9 are reduced, and the electromagnetic drive units 23a and 23b can be made thinner. However, the coils 22a and 22b and the magnets 21a and 21b must be distributed in number of the shutter blades, which increases the number of manufacturing steps and cost. In addition, since the electromagnetic drive units 23a and 23b and the arm 25 are arranged at different positions, the arrangement space is large and the device becomes large.

In view of the above, the present invention provides a method for winding a conductive coil of an electromagnetic drive unit into a flat coil whose longitudinal direction is a plane parallel to the opening / closing drive plane of the blade. The entire device is thinned by supporting the magnet and the arm integrally and freely swingably, so that it can be easily incorporated into a small optical device, and a single electromagnetic drive unit can be used properly. An object of the present invention is to provide a light amount adjusting device capable of obtaining an exposure image and an optical device incorporating the same.

[0010]

According to a first aspect of the present invention, there is provided a light amount adjusting device, comprising: a plurality of light amount adjusting members for variably adjusting an opening amount; In the light amount adjusting device provided with a swinging member to be driven and a driving unit including a magnet and a conductive coil, the conductive coil is formed into a flat, substantially rectangular shape having a plane parallel to an opening / closing drive plane of the light amount adjusting member as a longitudinal direction. Coil wound,
The swing member is rotatably supported in the coil winding space of the conductive coil, and further has an arm portion extending at least from the center of rotation in the coil winding longitudinal direction of the conductive coil, and the magnetic field of the magnet is formed. And the direction of the coil-inducing magnetic field induced by the current supply to the conductive coil always intersects within the opening / closing drive range of the oscillating member. It is characterized by being provided in.

According to the present invention, the magnet is directly arranged on the swinging member, and the coil is formed so as to surround the swinging member, and the coil has a flat and substantially rectangular shape whose longitudinal direction is parallel to the opening and closing drive plane of the light amount adjusting member. , The electromagnetic drive unit has a flat external shape that follows the external shape of the aperture mechanism, rather than the external appearance prominently protruding from the aperture mechanism as in the conventional case, making it possible to reduce the overall thickness of the device. . In addition, it can be easily incorporated into a small optical device,
By opening and closing a plurality of light amount adjusting members with a single electromagnetic drive unit to adjust the opening amount, it is possible to obtain an appropriate exposure image without optical axis deviation.

A light amount adjusting device according to a second aspect of the present invention includes a plurality of light amount adjusting members for variably adjusting the opening amount, a swing member for opening and closing the light amount adjusting member, a driving means including a magnet and a conductive coil, In a light amount adjusting device in which the swinging member and the driving means are incorporated in a base member provided in a main body supporting the light amount adjusting member, the conductive coil is moved in a longitudinal direction by a plane parallel to an opening / closing drive plane of the light amount adjusting member. A coil is wound around the base member in a flat, substantially square shape, and the swinging member is rotatably supported in the coil winding space of the conductive coil, and furthermore, in the coil winding longitudinal direction of the conductive coil. At least an arm extending from the center of rotation is formed, and the direction of the magnetic field of the magnet and the direction of the coil-induced magnetic field induced by the supply of current to the conductive coil are controlled by the swing. Always so as to intersect in the opening and closing range of the member, characterized in that a said magnet in the arm portion of the swing member.

According to the present invention, the conductive coil is directly wound around the base member supporting the swinging member and the magnet, provided on the main body supporting the light amount adjusting member. Is unnecessary, and the number of parts can be reduced, and the manufacturing cost can be reduced. Also,
A conductive coil formed of an extremely thin wire may be repeatedly expanded and contracted by its own heat or the like that generates heat by flowing an electric current, and may be disconnected. In this case, there is no need to remove the swinging member from the electromagnetic drive unit using a tool such as a screwdriver as in the related art, and it is only necessary to replace the outer conductive coil.

According to a third aspect of the present invention, in the light quantity adjusting device according to the first or second aspect, the magnet comprises a small piece magnet disposed at least on one side of the swing member so as to be appropriately separated from the swing center of the swing member. It is characterized by the following.

According to the present invention, since the magnet itself is lightweight and is disposed at an appropriate distance from the swing center,
A sufficient torque can be obtained with a relatively small torque. Also, since the area occupied by the magnet is extremely small,
The conductive coil can be easily flattened, and the entire device can be reduced in thickness, and can be easily incorporated into a small optical device.

According to a fourth aspect of the present invention, in the light quantity adjusting device according to any one of the first to third aspects, the reference position from the center of the oscillation at which the magnet is arranged is appropriately set according to the rotational torque of the oscillation member. It is characterized by being performed.

According to the present invention, the rotational torque according to the opening / closing speed or quantity of the light amount adjusting member to be driven can be changed by adjusting the position of the magnet arranged on the swing member.

According to a fifth aspect of the present invention, in the light amount adjusting device according to the first or second aspect, a concentric flat magnet is disposed at a swing center of the swing member.

According to the present invention, since only a single flat magnet formed so as to be fitted to the swing center shaft of the diaphragm blade swing member is arranged, the number of parts can be further reduced and assembly is required. Man-hours can also be reduced. Further, the positioning work for disposing the magnet is also facilitated. In addition, the conductive coil can be easily flattened, and the entire device can be reduced in thickness.

An optical device according to a sixth aspect of the present invention includes a light amount adjusting member for variably adjusting an opening amount, a swinging member for driving the light amount adjusting member to open and close, and a driving means comprising a magnet and a conductive coil. In the light amount adjusting device, the conductive coil is wound in a flat and substantially rectangular shape whose longitudinal direction is a plane parallel to the opening / closing drive plane of the light amount adjusting member, and the swing member is wound around the conductive coil. An arm is rotatably supported in the space and extends at least from the center of rotation in the longitudinal direction of coil winding of the conductive coil. The arm is induced by the direction of the magnetic field of the magnet and the supply of current to the conductive coil. And the direction of the coil-induced magnetic field
A light amount adjusting device in which the magnet is provided on an arm of the swinging member is arranged in an optical lens system so that the magnet always intersects within the opening / closing drive range of the swinging member. .

According to the present invention, the magnet is directly mounted on the arm for driving the light amount adjusting member, and the conductive coil is directly wound around the range in which the arm swings, so that the assembly process can be simplified. In addition, a portion in which a coil frame and a yoke which are separately formed as in the related art is disposed is omitted, and the entire light amount adjusting device can be reduced in size and thickness. Therefore, it can be mounted on a small optical device such as a video camera or a digital camera. In addition, since a plurality of light amount adjusting members are opened and closed by a single electromagnetic driving unit, driving force unevenness due to a difference in driving force of the electromagnetic driving unit, which tends to occur when an electromagnetic driving unit is configured separately as in the related art, is reduced. Therefore, the drive transmission force applied to each light amount adjusting member becomes uniform. For this reason, the optical axis shift of the light amount adjusting member that swings and changes with the exposure hole provided in the substrate is suppressed, and the light amount can always be appropriately adjusted.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a light amount adjusting device according to the present invention; FIG. 1 is a perspective view of a light amount adjusting device according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view of the light amount adjusting device, FIG. 3 is a cross-sectional view of the light amount adjusting device, and FIG. 5 and FIG. 6 are plan views of the light amount adjusting device, FIG. 7 is an exploded perspective view of a second embodiment of the light amount adjusting device according to the present invention, and FIG. 8 is an assembled light amount adjusting device according to the present invention. It is a built-in view of the optical device which was embedded.

As a specific example of the light amount adjusting device of the present invention, an aperture device for adjusting the exposure mounted on a small video camera, a digital camera or the like will be described in detail below. As shown in FIGS. 1 to 3, the diaphragm device includes a base member 3.
0, arm 31, first diaphragm blade 32a, second diaphragm blade 3
2b, a magnet 33, a conductive coil 34 for excitation comprising a driving coil and a braking coil, and an electrode terminal 3 for electrically connecting the driving coil and the braking coil to respective external devices.
7. Other components include a magnetic sensor (not shown) for capturing the moving position of the magnet and detecting the opening amount of the diaphragm.

The base member 30 is, as shown in FIG.
It is composed of a square planar substrate 60 and side wall portions 61 standing around the substrate 60. Also, the substrate 60
The surface is provided with exposure holes 39 and several guide pins 44 for guiding the direction in which the respective aperture blades slide.

A rotating shaft 41 is provided at the center of the arm 31. Drive pins 46a and 46b are provided on both sides of the shaft 41. This drive pin 46
a and 46b are a first aperture blade 32a and a second aperture blade 32
b are fitted into grooves 47a and 47b provided at respective ends thereof, and attached to the shaft 41 so as to be swingable.

The first diaphragm blade 32a and the second diaphragm blade 32b have, in addition to the grooves 47a, 47b, a long groove 48 provided along the sliding movement direction of these diaphragm blades.
And aperture openings 52a and 52b. The long groove 48 is provided to guide the sliding direction of the two diaphragm blades 32a and 32b and to prevent displacement. The aperture opening 52a is a round hole having substantially the same diameter as the exposure hole 39. The ND filter 53 (neutral density) is provided so as to cover a part of the round hole so as to prevent diffraction of light on the small aperture side. Filter). The one aperture opening 52 b has substantially the same diameter as the exposure hole 39, but is formed in a semicircular shape, and the open side of the semicircular shape is arranged in the opposite direction to the arm 31. Thus, the first diaphragm blade 3
2a and the aperture opening 5 formed in the second aperture blade 32b
The exposure light 39 is alternately slid over the exposure holes 39 with the 2a and 52b superimposed to limit the amount of light passing through the exposure holes 39.

As shown in FIG. 4, the magnet 33 has an NS magnetic pole surface which is magnetized and divided into two right and left poles.
The two magnets 33 are placed so as to face each other on both sides of the magnet, and a magnetic field B1 is generated by the two magnets 33 in the illustrated direction. On the other hand, arm 31
By supplying an electric current to the flat conductive coil 34 wound and arranged so as to surround the magnet 33 and the magnet 33, the coil attraction magnetic field B2 is induced in a direction perpendicular to the coil winding direction. The flat conductive coil 34, the arm 31, and the magnet 33 are disposed so that the magnetic field B1 generated by the two magnets 33 and the coil induced magnetic field B2 generated by the conductive coil 34 always intersect in the rotation allowable range φ1 to φ2 of the arm 31. ing. The magnetic field B1 generated by the two magnets 33 is equal to the magnetic field B induced by the conductive coil 34.
A rotational torque is applied to the magnet 33 so as to be along the direction 2. The arm 31 rotated by the rotation torque changes the direction of the coil magnetic field B2 by changing the current direction to the conductive coil 34 according to a preset throttle amount. As described above, the aperture amount can be adjusted by changing the direction in which the rotational torque of the arm 31 acts. The rotation torque generated in the arm 31 differs depending on the change in the moment at the position where the magnet 33 is placed.
Therefore, the position where the magnet 33 is placed is
As the distance from the center of rotation increases, the rotational torque increases,
The rotational torque becomes smaller toward the rotation center. By utilizing this, the opening / closing speed of the two diaphragm blades connected to the drive pins 46a and 46b can be adjusted.

Finally, a conductive coil 34 for excitation consisting of a driving coil and a braking coil is provided so as to surround the arm 31.
Is wound directly along the base member 30. This conductive coil 34 is wound around the arm 31 as shown in FIG.
This is performed over the entire swingable range of the magnet 33 attached to. As an example of the configuration of the conductive coil 34, for example, the drive coil has a wire diameter of 0.08 mm (0.07 mm to 0.07 mm).
9mm), 580 turns (500 turns to 600
Turns), the internal resistance is 100 ohms, the braking coil has a wire diameter of 0.045 mm (0.04 mm to 0.05 mm), the number of turns is 310 turns (300 to 500 turns), and the internal resistance is 180 ohms. The drive coil and the braking coil are formed in two layers in an overlapping manner. At this time, the current supplied to the drive coil is 30 mA (about 3 V) at the maximum. still,
A braking coil is not necessarily required.

The winding end of the wound conductive coil 34 is drawn out to an electrode terminal 37 provided on the base member 30 and connected to an external drive source. The direction of the current flowing through the conductive coil 34 is switched by the external drive source, and the arm 31 is swung. The swing of the arm 31 causes the drive pin 46
The first aperture blade 32a and the second aperture blade 32b fitted to a and 46b slide along the guide pin 44 to adjust the opening amount of the exposure hole 39. The adjustment of the opening amount is performed by a magnetic sensor (not shown) such as a Hall element provided in the base member 30.

Next, the operation of the aperture device having the above configuration will be described with reference to FIGS. FIG. 5 shows a state in which the portions of the aperture blades 32a and 32b except for the aperture openings 52a and 52b are overlapped to completely close the exposure hole 39. Thus, as the arm 31 swings,
The first diaphragm blade 32a and the second diaphragm blade 32b linked to the arm 31 slide in opposite directions. With this sliding movement, both aperture openings 52a, 5
2b gradually opens to limit the amount of light taken into the exposure hole 39. This sliding movement is performed along the long groove 48 in which the guide pin 44 is fitted. The aperture opening position is detected by a magnetic sensor (not shown) such as a Hall element provided on the substrate 60, and is controlled so as to stop at a position having an opening amount set by an externally provided control device. FIG. 6 shows both aperture blades 32a,
The aperture openings 52a and 52b of the 32b overlap with each other,
9 is the state when fully opened. In order to alternately shift to the state of FIGS. 5 and 6 in this manner, the conductive coil 3
4 by alternately switching the direction of the current to flow.

In the first embodiment of the light amount adjusting device, a length of 2.5 mm * width of 1.5 mm / thickness = 1.0 mm at both ends or one end with a shaft 41 provided on the arm 31 interposed therebetween.
In the second embodiment shown in FIG. 7, a single flat outer diameter 7.0 magnetized and divided into two poles of S and N around the shaft 41 is provided.
A columnar magnet 50 of mm * inner diameter 3.0 mm / thickness = 1.3 mm was provided. The magnetic poles of the magnet 50 have opposite polarities with respect to the center of rotation in the arm extending direction of the arm 31. This magnet 50 has an arm 3 at the center.
It is formed in a donut shape provided with a hole into which one shaft 41 is fitted. When assembling, it is only necessary to fit the magnet 50 to the shaft 41, so that the number of parts and the number of manufacturing steps are reduced. Other configurations and operating principles are the same as those of the first embodiment, and thus detailed description is omitted.

FIG. 8 shows an embodiment in which the light amount adjusting device according to the first embodiment or the second embodiment is incorporated in an optical lens system. Reference numeral 40 denotes a light amount adjusting device having an aperture mechanism, and an optical unit 73 is configured by arranging an optical lens group before and after the light amount adjusting device 40. The optical unit 73 includes a front fixed lens barrel 70 and a moving lens barrel 71 on the front side of the light amount adjusting device 40, and includes a rear fixed lens barrel 72 on the rear side. Reference numeral 74 denotes a camera body, and the optical unit 73 is mounted on a lens mounting portion 75 provided on the front surface thereof.

In addition to the above-described embodiment, one of the two magnets 33 shown in FIG. 3 is oriented in the vertical direction in the drawing, for example, the direction in which the magnetic pole of the magnet 33 on the right side of the drawing is above the N pole and below the S pole. Alternatively, the other may be similarly arranged in the vertical direction of the drawing, for example, with the magnetic pole of the magnet 33 on the left side of the drawing facing down the N pole and the S pole facing up. Also in this case, in accordance with Fleming's left-hand rule, magnetic forces are generated in directions opposite to each other with the rotation center of the arm 31 interposed between the directions of the currents flowing through the coils 34 located above and below the drawing. A similar rotational force of the arm 31 is obtained.

Since the light amount adjusting device 40 of the present invention is thin and small as a whole, including the electromagnetic drive unit, it can be easily mounted in the optical lens barrel. Also, since it operates with a single electromagnetic drive source, it consumes less power and is suitable for use in aperture mechanisms such as small video cameras and digital cameras.

[Brief description of the drawings]

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

FIG. 2 is an exploded perspective view of the light amount adjusting device.

FIG. 3 is a sectional view of the light amount adjusting device.

FIG. 4 is a perspective view of an arm of the light amount adjusting device.

FIG. 5 is a plan view of the light amount adjusting device in a state where aperture blades are closed.

FIG. 6 is a plan view of the light amount adjusting device in a state where aperture blades are opened.

FIG. 7 is an exploded perspective view of a second embodiment of the light amount adjusting device according to the present invention.

FIG. 8 is a conceptual diagram showing a state when the light amount adjusting device according to the present invention is incorporated into an optical lens barrel.

FIG. 9 is an assembly view showing an example of the structure of a conventional light amount adjusting device.

FIG. 10 is a plan view showing another example of the structure of the conventional light amount adjusting device.

[Explanation of symbols]

 31 Arm 33 Magnet 34 Conductive coil 41 Shaft B1 Magnetic field of magnet B2 Coil attraction magnetic field φ1, φ2 Allowable rotation of arm

Claims (6)

[Claims] 1. A light amount adjusting device comprising: a plurality of light amount adjusting members for variably adjusting an opening amount; a rocking member for driving the light amount adjusting member to open and close; and a driving unit including a magnet and a conductive coil. The coil is wound in a flat, substantially rectangular shape having a surface parallel to the opening / closing drive plane of the light amount adjusting member as a longitudinal direction, and the swing member is rotatably supported in the coil winding space of the conductive coil. In addition, an arm portion extending at least from the center of rotation is formed in the coil winding longitudinal direction of the conductive coil, and the direction of the magnetic field of the magnet and the direction of the coil magnetic field induced by current supply to the conductive coil are formed. Wherein the magnet is provided on the arm of the swinging member such that the magnets always intersect within the opening and closing drive range of the swinging member. 2. A light amount adjusting member for variably adjusting an opening amount, a swinging member for opening and closing the light amount adjusting member, a driving means including a magnet and a conductive coil, and a main body for supporting the light amount adjusting member. In a light amount adjusting device in which the swinging member and the driving means are incorporated in a provided base member, the conductive coil is formed into a flat, substantially square shape having a surface parallel to an opening / closing drive plane of the light amount adjusting member as a longitudinal direction. An arm that winds a coil around the base member, rotatably supports the swinging member in the coil winding space of the conductive coil, and extends at least from the rotation center in the coil winding longitudinal direction of the conductive coil. Forming a portion, the direction of the magnetic field of the magnet and the direction of the coil magnetic field induced by the current supply to the conductive coil are within the opening and closing drive range of the rocking member. So as to intersect the light quantity adjusting device characterized by comprising providing the magnet arm of the swing member. 3. The light amount adjusting device according to claim 1, wherein the magnet comprises a small piece magnet arranged on both sides of the swing center of the swing member. 4. The light amount adjusting device according to claim 1, wherein a reference position from the center of the oscillation at which the magnet is arranged is set as appropriate in accordance with a rotational torque of the oscillation member. . 5. The light amount adjusting device according to claim 1, wherein a concentric flat magnet is arranged at a swing center of the swing member. 6. A light amount adjusting device comprising: a plurality of light amount adjusting members for variably adjusting an opening amount; a rocking member for driving the light amount adjusting member to open and close; and driving means including a magnet and a conductive coil. The coil is wound in a flat, substantially rectangular shape having a surface parallel to the opening / closing drive plane of the light amount adjusting member as a longitudinal direction, and the swing member is rotatably supported in the coil winding space of the conductive coil. In addition, an arm portion extending at least from the center of rotation is formed in the coil winding longitudinal direction of the conductive coil, and the direction of the magnetic field of the magnet and the direction of the coil magnetic field induced by current supply to the conductive coil are formed. And a light quantity adjusting device provided with the magnet on the arm of the swinging member so as to always intersect within the opening and closing drive range of the swinging member. Light amount adjusting device embedded optical device according to claim.