JP2002258348A - Light quantity controller and electromagnetic driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive, small-sized light quantity controller and an electromagnetic driving device which each requires a small number of components and a small number of assembly stages. SOLUTION: In the light quantity controller equipped with a columnar magnet which rotates reciprocally, a blade member which is so arranged as to enter an optical path of photography, a coil which imparts turning force to the magnet, a yoke which is installed around the coil and made of a magnetic material, a means which transmits the turning force of the coil to the blade member, and a means which restricts the operation range of the magnet; a proximity part and a slit where magnetism converges, for example, outside the operation range of the magnet are provided to the yoke, the operation range of the magnet is provided including a vertical line nearly perpendicular to the magnetic pole direction of the magnet when the magnetic pole of the magnet is positioned at the most magnetically stable position, and when the coil is not energized, the blade member is held in a state of being in and off the optical path of photography.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a video camera,
The present invention relates to a light amount control device mounted on and used in optical devices such as various camera devices such as a steel camera, and an electromagnetic drive device used in the light amount control device.

[0002]

2. Description of the Related Art In general, this kind of light amount control device is used by being incorporated in a photographing lens section of an optical apparatus in order to obtain an appropriate photographing light amount and exposure time.

In the case of a camera equipped with an image pickup device such as a CCD, when the power of the camera body is turned off, the shutter blade must be held in a state in which a photographing optical path is closed in order to protect the image pickup device. However, except when the camera body is turned on and an image is taken, the shutter must be held with the imaging optical path open in order to project the subject on the monitor device. In recent years, low-cost steel cameras, which do not require much function, use only one aperture blade and limit the aperture to two types, large and small, depending on the presence or absence of the aperture blade. Have been. In this case, the aperture blades are held in a state where the diameter of the imaging optical path is reduced or in a fully opened state according to the amount of light. Any of these holdings must be performed in a so-called non-energized state in which no power is supplied to save power.

Conventionally, various methods have been proposed in response to such a need.
No. 0-221740. In this method, the blade member is driven by the rotational force of a magnet that rotates when the coil is energized, thereby shielding and stopping the photographing optical path. Then, pins made of a ferromagnetic material that regulates the drive range of the output pin that engages with the blade member integrally with the magnet are installed at both ends of the drive range and between the yoke and the magnet, and the pin between the output pin and the pin of the ferromagnetic material is provided. By using the magnetic attraction force generated in the optical path, the optical path is opened and closed and the aperture is maintained in a non-energized state.

However, this method has a problem because the number of parts is increased, the number of assembly steps is increased, and the cost is increased. In recent years, along with downsizing of cameras, downsizing of a light amount control device and an electromagnetic driving device is also required, and a yoke having a diameter of, for example, about 5 mm is used due to a problem of allowable space. When a small yoke must be used in this way, it is difficult to install two ferromagnetic pins by the above-described conventional method, and the positions of the ferromagnetic pins vary, so that a stable product can be obtained. Supply was difficult.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an inexpensive light quantity control device and an electromagnetic drive device with a small number of assembly steps without increasing the number of parts. It is another object of the present invention to provide a small-sized light quantity control device and an electromagnetic drive device that can hold the opening and closing of the optical path and hold the degree of opening in a non-energized state and reduce variations in the held state.

[0007]

The present invention has the following features to solve the above-mentioned problems. A column-shaped magnet that reciprocates and rotates, a blade member arranged so as to be able to enter the imaging optical path, and a coil for applying a rotational force to the magnet,
A yoke made of a magnetic material installed around the coil;
2. A light amount control device comprising: means for transmitting the rotational force of the magnet to the blade member; and means for restricting the operating range of the magnet, wherein the distance between the magnet and the yoke is minimized in claim 1, and An approaching portion where the magnetism occurs is provided by the yoke outside the operating range of the magnet, in claim 2 a slit is provided in the yoke where magnetic concentration occurs outside the operating range of the magnet, and in claim 3, the slit is outside the operating range of the magnet. The yoke is provided with an approaching portion and a slit. Further, by providing the operating range of the magnet so as to include a vertical line that is substantially perpendicular to the magnetic pole direction of the magnet when the magnetic pole of the magnet is located at the most magnetically stable position, between each approaching portion and the magnetic pole The suction force between the yoke end face and the magnetic pole forming the slit, the suction force between the yoke end face and the magnetic pole forming the slit, and / or between the approaching portion and the magnetic pole causes the blade member to shoot when the coil is not energized. A light amount control device configured to hold a light beam in a state of entering the light path and a state of being retracted outside the photographing light path.

The blade member is constituted by a shutter blade member or an aperture blade member.

Further, the light quantity control device includes a coil frame composed of two upper and lower frames for winding the coil, and the coil frame and the slit are provided at a predetermined position to place the approach portion and / or the slit where magnetic concentration occurs. Preferably, a positioning means is provided between the yokes.

Further, a cylindrical magnet reciprocatingly rotating, a coil for applying a rotational force to the magnet, a yoke provided around the coil and made of a magnetic material, and means for transmitting the rotational force of the magnet And a means for restricting the operating range of the magnet, wherein the distance between the magnet and the yoke is minimized outside the operating range of the magnet and magnetic concentration occurs. In the eleventh aspect, the yoke is provided with a slit where magnetic concentration occurs outside the operating range of the magnet, and in the twelfth aspect, between the magnet and the yoke outside the operating range of the magnet. The approach portion where the distance is minimized and magnetic concentration occurs is provided in the yoke, and a slit where the magnetic concentration occurs is provided in the yoke. Further, by providing the operating range of the magnet so as to include a vertical line that is substantially perpendicular to the magnetic pole direction of the magnet when the magnetic pole of the magnet is located at the most magnetically stable position, between each approaching portion and the magnetic pole Attraction force, the attraction force between the yoke end face forming the slit and the magnetic pole,
Electromagnetic drive wherein the magnetic poles of the magnets are held at both ends of the operating range when the coil is not energized by an attractive force between a yoke end face forming a slit and the magnetic poles and / or between the approaching portion and the magnetic poles. apparatus.

Further, the electromagnetic drive device includes a coil frame composed of two upper and lower frames for winding the coil, and the electromagnetic drive device is provided with the coil frame for installing the approach portion and / or the slit at a predetermined position where magnetic concentration occurs. Preferably, a positioning means is provided between the yokes.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view of the light amount control device, and FIG. 2 is an exploded perspective view of the light amount control device. First, as shown in FIG. 2, the light quantity control device is configured by laminating a shutter blade 3, an intermediate intervening plate 4, and an aperture blade 5 between a pair of upper and lower substrates 1, 2 in this order. (Actuator) for individually driving the diaphragm blades 5
6, 7 are attached.

The substrate 1 is provided with an optical axis opening 8 which forms a photographic optical path and has an optical axis indicated by XX as a center. Pins 9 and 10 for mounting the shutter blade 3 and the aperture blade 5 are mounted on the substrate 1. Pin 11 is implanted. These pins 9, 10 and 11 may be provided with a pin member separate from the substrate or provided on the second substrate 2 side, and the number and arrangement positions of the shutter blades 3 and the aperture blades 4 will be described later. It is determined by the number of components.

Further, the substrate 1 is provided at the periphery of the optical axis opening 8 with projection-like guides 12 and 13 for guiding the two-part shutter blades 3 described later. Further, relief holes 17 and 18 for the transmission means of the drive device are provided.

The shutter blades 3 are shown as an example with two shutter blades, but may be formed as one shutter blade as shown in FIG. 8B.

Two shutter blades 31, 3 of the illustrated shape are shown.
2 has arcuate curved portions 31a and 32a inside so as to open and close the optical axis opening 8 by dividing it into two.
a and 32a with ND filters (neutral d
It is also possible to attach an energy filter. Further, a shape as shown in FIG. 8A may be used without providing the curved portion.

At the base end of each of the shutter blades 31, 32, fitting holes 33, 34 for fitting the pins 9, 10 implanted in the first substrate 1 are engaged with transmission means of a drive device described later. An engagement hole 35 is formed. Therefore, as shown in FIGS. 1 and 3, the shutter blade 3 is installed so that the drive is transmitted and swings around the pins 9 and 10 to open and close the optical axis opening 8. As shown in FIG. 8 (c), two shutter blades are used, each of which is individually engaged with the transmission means of the driving device, and the blades are slid linearly to open and close the optical axis opening 8. A configuration may be used.

FIG. 3 shows an embodiment in which a shutter blade is used alone as a shutter driving device. FIG. 3A shows the shutter blades 31 and 32 entering the photographing optical path and the optical axis opening 8 as in FIG. FIG. 3B shows a state where the shutter blades 31 and 32 are retracted outside the imaging optical path and the optical axis opening is fully opened.

As described above, the shutter blades 3 are incorporated into the first substrate 1, and then the aperture blades 5 are incorporated. An intermediate intervening plate 4 is provided to prevent interference between these blades 3, 5. The illustrated intermediate intervening plate 4 includes projections 14a, 14b, 14c, 14 provided on the first substrate so as to form a small gap with the shutter blade 3 on the substrate 1 in which the blade is incorporated.
d. The intermediate plate 4 is provided with an optical axis opening 8 and positioning holes 41 and 42.
And positioning pins 15, 1 implanted in the first substrate 1.
6, and its position is guaranteed.
Further, there are provided holes 43, 44, 45 for fitting into the pins 9, 10 and 11 implanted in the substrate 1, and relief holes 46, 47 for the transmission means of the driving device.

The aperture blade 5 is composed of one sheet, and has an opening 51, a fitting hole 52, and an engaging hole 53 formed therein. The aperture blade 5 of the present embodiment has one opening 51 set smaller than the aperture of the optical axis opening 8, but has a large opening L larger than the aperture of the optical axis opening 8 as shown in FIG. 9. Small small opening S
It may be a shape provided with. Further, it may be composed of two or more blades whose diameter can be continuously changed.

The pins 11 implanted in the substrate 1
And the diaphragm blade 5 is supported on the intermediate plate 4.
Further, when the transmission means of the driving device described later engages with the engagement hole 53, the driving force is transmitted, and the diaphragm blade 5 swings about the pin 11, and as shown in FIGS. It is installed to control the caliber of.

FIG. 4 shows an embodiment in which a shutter blade is used alone as a shutter driving device.
FIG. 4A shows a state in which the diaphragm blade 5 is retracted outside the photographing optical path as in FIG. 1, and FIG. 4B shows a state in which the diaphragm blade 5 enters the photographing optical path and narrows the optical axis opening 8. I have.

The substrate 2 has an optical axis opening 8 at the center and holes 21, 22, which fit into pins 9, 10 and 11, which are implanted in the substrate 1.
23, and relief holes 25 and 26 for the transmission means of the drive unit are formed. The second substrate 2 has tab-shaped protrusions 24a, 24 protruding to the back side of the paper surface of FIG.
b, 24c and 24d are protrusions 14a of the first substrate 1,
It is formed at a position where it is joined to 14b, 14c, 14d.

Accordingly, the intermediate plate 4 is sandwiched between the projections 14a, 14b, 14c, 14d of the substrate 1 and the projections 24a, 24b, 24c, 24d of the second substrate 2, and the two substrates are fixed by fixing screws 60. The intermediate intermediate plate 4 is fixed by the connection, and the shutter blades 3a, 3b are supported between the intermediate intermediate plate 4 and the projecting guides 12, 13 of the first substrate 1. The diaphragm blade 5 is supported between the two substrates 2 and assembled.

Here, a driving device for the shutter blade 3 and the aperture blade 5 will be described. The driving device 6 for the shutter blade and the driving device 7 for the aperture blade have the same configuration. Each drive device is a substrate 1 (not shown).
The pins and holes provided on the back surface of the substrate 1 and the holes and pins provided on the drive unit are fitted and fixed to the back surface of the substrate 1. Therefore, the first embodiment of the driving device will be described in detail with reference to FIGS.

Driving Apparatus Embodiment 1 The driving apparatuses 6 and 7 are rotatable cylindrical magnets 72 magnetized in NS2 poles and having a hole 72a, and a rotation that is fitted into the hole 72a of the magnet 72 and is integrally attached to the magnet 72. A shaft 77, an arm 70 of a transmission means integrally attached to the rotating shaft 77 and transmitting the rotational force of the magnet 72 to the blade member, an upper coil frame 73 and a lower coil frame 74 installed around the magnet 72, and an upper coil frame 73; It comprises a coil 75 spirally wound around 74 to apply a rotational force to the magnet 72, and a yoke 76 installed so as to surround the upper coil frame 73.

The rotary shaft 77 has a hole 7 provided in the magnet 72 so that the magnetic poles of the arm 70 and the magnet 72 are substantially perpendicular to each other.
2a is fixed to the magnet 72.

A positioning pin (not shown) is implanted on the back surface of the upper coil frame 73.
4 is fitted into the upper coil frame 73 so that the lower coil frame 7
Fixed to 4. The magnet 72 is installed so as to be sandwiched between the upper coil frame 73 and the lower coil frame 74, and the tip portions 77a and 77b of the rotating shaft 77 fixed to the magnet are attached to the lower coil frame 74 and the upper coil frame 74, respectively. The magnets 72 are installed so as to rotate with the rotation shaft 77 as a center, respectively engaging with holes (lower coil frame holes 90, upper coil frame not shown) provided in 73.

The lower coil frame 74 has the magnet 72
A window 77 for regulating means for regulating the rotation of the arm 70 within a predetermined operating range 80 is provided.
, The rotation range of the arm 70 is regulated, and the magnet 72 can reciprocate within a predetermined operation range 80 formed by OO 'and QQ' as shown in FIG. .

Further, the upper coil frame 73 and the lower coil frame 7
4 are provided with grooves 85 and 89, respectively, and a coil 75 is wound in these grooves.

The yoke 76 is formed by pressing a flat plate made of a magnetic material having a predetermined length against a D-shaped mold to form a D-shape.
A linear portion 81 and a circular portion 82 are provided.
A slit 84 formed at both end surfaces of the flat plate is provided at the center of the entire length in the longitudinal direction.

The upper coil frame 73 has a straight portion 86 along the inner wall of the straight portion 81 including the slit 84 of the yoke 76.
And the curved portion 8 along the inner wall of the curved portion 82 of the yoke 72
7, the inner wall of the straight portion 81 of the yoke 76 is aligned with the straight portion 86 of the upper coil frame 73, and the inner wall of the curved portion 82 of the yoke 76 is aligned with the curved portion 87 of the upper coil frame 73 for positioning and fitting. Are combined.

Therefore, by such positioning, as shown in FIG. 10, the slit 84 provided in the linear portion 81 of the yoke 76 is provided outside the operating range. Further, a vertical line PP in the magnetic pole direction TT ′ which is most magnetically stable, which will be described later, is provided at an intermediate position of the operating range 80,
Reciprocally rotate this PP symmetrically, and Q
The distance between '-T' and the distance between O'-T 'are equal. In the case where the yoke is D-shaped and has a small diameter of 5 mm or the like as in the present embodiment, positioning and fixing are difficult, so that as shown in FIG.
Is also D-shaped, and the outer peripheral surface other than the groove 85 is fitted to the yoke 76 so as to be along the yoke inner wall, so that the above positional relationship can be reliably obtained.

In this embodiment, magnets after magnetization are used. However, a similar positional relationship can be obtained by magnetizing after assembling the electromagnetic drive device.

Next, the operation will be described. FIG.
(A) shows that the magnetic pole is located on QQ 'and the south pole is the slit 84.
, The arm 70 comes into contact with the left end of the window 77 of the regulating means and stops, and the blade member (not shown) enters the photographing optical path. Located in N
This shows a state in which the pole approaches the slit 84, the arm 70 comes into contact with the left end of the window 77 of the restricting means and stops, and the blade member (not shown) is retracted out of the imaging optical path. FIG.
When a current is supplied to the coil 75 in the state shown in (a), an electromagnetic force based on Fleming's left-hand rule is generated and the magnet 72
Rotates counterclockwise, the arm 70 stops at the right end of the window 77, and the state shown in FIG. At this time, this state is maintained even if the current is turned off. Also, in the state shown in FIG. 11B, when a reverse current is supplied to the coil 75, an electromagnetic force based on Fleming's left hand rule is generated, the magnet 72 rotates clockwise, and the arm 70 hits the left end of the window 77. The operation is stopped and the state shown in FIG. 11A is reached. At this time, this state is maintained even if the current is turned off.

Here, the shape of the yoke and its magnetic effect will be described with reference to FIG. First, assuming that there is no restricting means for restricting the operating range of the magnet and that the magnetic pole is located at an arbitrary position, the yoke is formed in a D-shape, and the approaching portion 83 in which the distance between the magnet and the yoke is minimized. Is provided, magnetic concentration occurs in the approach portion 83, and the approach portion 83
Attraction force is generated between one of the magnetic poles close to the approaching portion 83 and the approaching portion 83 as shown in FIG. 12A. And a rotational force acts on the magnet to achieve this state. Further, when the slit 84 is provided in a part of the cylindrical yoke, magnetic concentration occurs due to the end face effect in the slit 84, and an attractive force is generated between any magnetic pole close to the slit 84 and the end face of the yoke forming the slit. Occurred and FIG.
As shown in (b), the state in which the slit faces any one of the magnetic poles near the slit 84 is the most magnetically stable state, and a rotational force acts on the magnet to achieve this state. Further, when the yoke is formed in a D-shape and the approaching portion 83 is provided, and the slit 84 is provided in the approaching portion 83, greater magnetic concentration occurs, and any magnetic pole and slit near the approaching portion 83 (and the slit 84) are formed. A larger attractive force is generated between the end faces of the yoke forming the magnetic field, and the state where one of the magnetic poles close to the approaching portion 83 (and the slit 84) faces as shown in FIG. State,
Rotational force acts on the magnet to achieve this state. In this embodiment, a larger magnetic concentration and attractive force are generated as shown in FIG.
This is an example utilizing the magnetic characteristics shown in FIG.

The magnetically stable state at the position where the magnetic pole and the slit face each other as shown in FIG. 12B depends on conditions such as the diameter of the magnet, the thickness of the yoke, the diameter of the yoke, and the size of the slit. It can be obtained by selecting.

Therefore, in the case of the state shown in FIG. 11B under non-energization, as shown in FIG. 12C due to the attractive force between the N pole near the slit 84 where the magnetic concentration occurs and the yoke end face forming the slit 84. A counterclockwise rotational force acts on the magnet 72 so that the magnet 72 is in a magnetically stable state (the magnetic pole is positioned on TT ′), but the arm 70 comes into contact with the right end of the window 77 so that the magnetic pole is The position of O-O 'is maintained, and the blade member is kept in a state of being retracted outside the imaging optical path. Similarly, in the state of FIG. 11A, the magnetically stable state shown in FIG. 12C is generated by the attractive force between the S pole near the slit 84 where the magnetic concentration occurs and the yoke end surface forming the slit 84. A clockwise rotational force acts on the magnet 72 so that the magnetic pole is positioned on the TT ′ (the magnetic pole is positioned on the TT ′). Is maintained, and the state in which the blade member has entered the photographing optical path is maintained.

Further, a perpendicular line PP of the magnetic pole direction line TT ', which is magnetically most stable, is provided at an intermediate position of the operating range 80 by the above-described positioning means, and the line between Q'-T' and O '
11A and 11B, an equal rotational force (holding force) is obtained in the state of FIGS. 11A and 11B.

In order to maintain the magnetic poles at both ends of the operating range in the non-energized state, the positions of the approaching portions and slits where the magnetic concentration occurs are provided outside the operating range as described above.
At that time, it is necessary to set the vertical line PP of the magnetic pole direction TT 'which is magnetically stable to be within the operation range, and to set the magnet so as to reciprocate over the PP. This is because if there is no such a positional relationship as described above, the attractive force generated between one magnetic pole and the approaching portion and / or the slit becomes strong, and the magnetic pole is moved to both ends of the operating range (on O-O 'and Q −Q
This is because it becomes impossible to hold in (1) above.

Also, while maintaining the above positional relationship, the positions of the slit and the approaching portion are changed outside the operating range, and the distance between O'-T 'and Q-T' is made different, so that Q- The balance of the holding force between Q 'and OO' can be changed.

Further, by using the above-described positioning means, even when the diameter of the yoke is as small as 5 mm, for example, the positional relationship between the yokes does not vary during the manufacturing process and the product can be supplied stably. Further, the positional relationship does not change due to vibration or the like during use of the product.

In this embodiment, the largest attraction force can be obtained by providing the approach portion where the magnetic concentration occurs and the slit at the same position. However, the position of the approach portion and the slit is set outside the operating range. It is of course possible to keep the magnetic poles at both ends of the operating range even if one of the magnetically stable positions is used.

In this embodiment, the approach portion and the slit are provided at the same position, and a stronger suction force is used as a holding force.
As shown in FIG. 12 (a), the yoke is formed in a D-shape, an approaching portion is provided, and the same positional relationship as in the present embodiment is obtained, so that the magnetic poles can be held at both ends of the operating range in a non-energized state. Of course it is possible. Further, by changing the position of the approaching portion outside the operating range while maintaining the same positional relationship as in the present embodiment, it is also possible to make the holding forces at both ends of the operating range different. In this case, a similar positional relationship can be stably provided by the similar positioning means described above, and the position does not change during use.

In the present embodiment, the yoke is formed in a D-shape to provide an approaching portion where the distance between the magnet and the yoke is minimized and magnetic concentration occurs. There is no.

In this embodiment, a method is used in which a window is provided in the lower coil frame to regulate the operating range of the magnet. However, as shown in FIGS. 3 and 4, the projections 61, 62, 6
3, 64 may be provided, and the operating range of the magnet may be regulated by each blade member colliding with these projections. When this means is used, the impact generated when each blade member collides with each projection is absorbed by the bending of the blade member, and the recoil is reduced.

Second Embodiment of the Driving Apparatus Next, a second embodiment of the driving apparatus will be described with reference to FIGS.

FIG. 7 is an exploded perspective view of the driving device according to the second embodiment.
The same components as those in the first embodiment are denoted by the same reference numerals. The difference from the first embodiment is that the yoke 76 and the upper coil frame 73
And the method of positioning between the yoke 76 and the upper coil frame 73.

The yoke 76 of this embodiment is formed by pressing a flat plate made of a magnetic material having a predetermined length against a cylindrical mold and molding it into a cylindrical shape. And concave portions 91a, 91b, 91c,
91d are provided. The slit 84 may be formed by cutting a cylindrical yoke. The upper coil frame 73 has convex portions 92a, 92b, 92c,
A recess 91 provided in the yoke 76
a, 91b, 91c, and 91d are fitted and fixed respectively.

FIG. 13 shows a state fixed by such positioning. As shown in FIG.
Numeral 4 is provided outside the operating range 80 of the magnet, and a perpendicular line PP of the magnetic pole direction line TT ', which is magnetically most stable, is provided at an intermediate position of the operating range 80. The magnet 72 reciprocates this PP symmetrically. And the distance between Q′-T ′ and the distance between O′-T ′ are equalized. Therefore, as described with reference to FIG.
The magnetic poles are held at both ends of the operating range 80 in a non-energized state by the attraction force generated between the end face of the yoke forming the magnet 4 and the magnetic poles of the magnet 72, and equal holding force is obtained at both ends. The position does not vary for each product during the manufacturing process, and does not change due to vibration or the like during use of the product.

In this embodiment, the slit in which the magnetic concentration occurs is formed in the entire length of the yoke in the longitudinal direction, but may be provided in a part of the yoke in the longitudinal direction as shown in FIG.

As in the first embodiment, in this embodiment, in order to maintain the magnetic poles at both ends of the operating range in the non-energized state, the position of the slit where the magnetic concentration occurs is provided outside the operating range as described above. At this time, it is necessary to set the vertical line PP of TT ', which is magnetically stable, within the operation range and the magnet to reciprocate over the PP. Further, it is of course possible to change the holding force at both ends by moving the position of the slit outside the operation range while maintaining the above positional relationship.

In this embodiment, four recesses are provided on the yoke and four protrusions are provided on the upper coil frame as the positioning means, and these are fitted to each other to form the positioning means.
There is no problem if two or more slits are provided so that the slits can be fixed at predetermined positions.

[0054]

As described above, according to the present invention, without increasing the number of steps, the number of parts, and the cost, a magnetic attractive force is generated by providing a slit or an approach portion where magnetic concentration occurs by a yoke. Using the magnetic attraction force, the blade member can be held in a state in which the blade member has entered the imaging optical path and retracted outside the imaging optical path in a non-energized state, and a stable holding force can be obtained by providing a positioning means. It is possible to provide a small light quantity control device and a small electromagnetic drive device that can perform the control.

[Brief description of the drawings]

FIG. 1 is a plan view of a light quantity control device.

FIG. 2 is an exploded perspective view of FIG.

FIG. 3 is a plan view of a light quantity control device equipped with only shutter blades.

FIG. 4 is a plan view of a light quantity control device equipped with only aperture blades.

FIG. 5 is a cross-sectional view of the driving device according to the first embodiment.

6 is an exploded perspective view of FIG.

FIG. 7 is an exploded perspective view of a driving device according to a second embodiment.

FIG. 8 is a plan view of shutter blades that can be incorporated in the light quantity control device.

FIG. 9 is a plan view of an aperture blade that can be incorporated in the light amount control device.

FIG. 10 is a plan view of the first embodiment of the electromagnetic driving device.

FIG. 11 is an explanatory diagram of an operation of the electromagnetic driving device.

FIG. 12 is a diagram illustrating the magnetic action of the electromagnetic drive device.

FIG. 13 is a plan view of a second embodiment of the electromagnetic driving device.

FIG. 14 is a modified example of the approach portion provided on the yoke.

FIG. 15 is a modified example of the slit provided in the yoke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1 2 Substrate 2 3 Shutter blade 4 Intermediate interposed plate 5 Aperture blade 6 Shutter drive device 7 Aperture drive device 8 Optical axis opening 72 Magnet 73, 74 Coil frame 75 Coil 76 Yoke 77 Drive transmission means (arm) 80 Actuation of magnet Range 83 Approaching part 84 Slit

Claims (16)

[Claims] 1. A column-shaped magnet which is magnetized in a diametric direction and reciprocates and rotates, a blade member arranged so as to be able to enter into a photographing optical path, a coil for applying a rotational force to the magnet, and around the coil. A light amount control device comprising: a yoke that is installed and made of a magnetic material; a unit that transmits a rotational force of the magnet to the blade member; and a unit that regulates an operating range of the magnet. The yoke is provided with an approaching portion where the distance between the yoke is the smallest and magnetic concentration occurs, and furthermore, when the magnetic pole of the magnet is located at a position where it is magnetically most stable, a vertical direction substantially perpendicular to the magnetic pole direction of the magnet is provided. The operating range of the magnet is provided so as to include a direction line, and when the coil is not energized, the attraction force generated between the approaching portion and the magnetic pole of the magnet causes the blade member to enter the imaging optical path. A light quantity control device characterized in that the light quantity control device is held in a state and a state of being retracted out of a photographing optical path. 2. A column-shaped magnet which is magnetized in a diametric direction and reciprocates and rotates, a blade member arranged so as to be able to enter into a photographing optical path, a coil for applying a rotational force to the magnet, and around the coil. A cylindrical yoke that is installed and made of a magnetic material, and means for transmitting the rotational force of the magnet to the blade member;
Means for regulating the operating range of the magnet, wherein a slit where magnetic concentration occurs outside the operating range of the magnet is provided in the yoke, and the magnetic pole of the magnet is located at the most magnetically stable position. An operating range of the magnet is provided so as to include a vertical line that is substantially perpendicular to the magnetic pole direction of the magnet when it is located, and a gap is generated between a yoke end face forming the slit and a magnetic pole of the magnet when the coil is not energized. A light amount control device, wherein the blade member is held by a suction force in a state in which the blade member enters the photographing optical path and in a state in which the blade member is retracted outside the photographing optical path. 3. A column-shaped magnet which is magnetized in a diametric direction and reciprocates and rotates, a blade member arranged so as to be able to enter into a photographing optical path, a coil for applying a rotational force to the magnet, and around the coil. A yoke made of a magnetic material, a means for transmitting the rotational force of the magnet to the blade member, and a means for regulating an operating range of the magnet; The yoke is provided with an approaching portion where the distance between the magnet and the yoke is the smallest and where the magnetic concentration occurs, the slit where the magnetic concentration occurs is provided in the yoke, and the magnetic pole of the magnet is located at the most magnetically stable position. An operating range of the magnet is provided so as to include a vertical line substantially perpendicular to the magnetic pole direction of the magnet when positioned, and is generated between the approach portion and the magnetic pole of the magnet when the coil is not energized. By the attraction force and / or the attraction force generated between the end face of the yoke forming the slit and the magnetic pole of the magnet, the blade member is held in a state of entering the imaging optical path and in a state of being retracted outside the imaging optical path. A light quantity control device characterized by the above-mentioned. 4. The light amount control device according to claim 3, wherein the slit is provided in the approach portion. 5. A coil frame comprising an upper and lower frame provided around the magnet for winding the coil, wherein at least the coil frame is provided for installing the approaching portion or the slit at a predetermined position. A positioning means is provided between one of said yoke and said yoke.
The light amount control device according to any one of the above. 6. An outer peripheral surface extending along the inner wall of the yoke including the approach portion and the periphery thereof is provided on one of the coil frames composed of the upper and lower frames, and the yoke and the coil frame are fitted. 6. The light amount control device according to claim 1, wherein positioning of the approaching portion is performed by positioning means. 7. The coil frame comprising the upper and lower two frames is provided with at least two or more projections, and the yoke is provided with at least two or more depressions, and the projections and the depressions are fitted to each other. The light amount control device according to claim 2 or 5, wherein positioning of the slit is performed by positioning means. 8. The light amount control device according to claim 1, wherein the blade member is a shutter blade member that blocks the photographing optical path. 9. The light amount control device according to claim 1, wherein the blade member is a diaphragm blade member that adjusts a diameter of the photographing optical path. 10. A columnar magnet which is magnetized in a diameter direction and reciprocates and rotates, a coil for applying a rotational force to the magnet, a yoke provided around the coil and made of a magnetic material, and a rotational force of the magnet And a means for restricting an operating range of the magnet, wherein the distance between the magnet and the yoke is minimized outside the operating range of the magnet, and an approaching portion where magnetic concentration occurs is determined. The operating range of the magnet is provided so as to include a vertical line that is substantially perpendicular to the magnetic pole direction of the magnet when the magnetic pole of the magnet is located at the most magnetically stable position. An electromagnetic drive device wherein the magnetic poles of the magnets are held at both ends of the operating range by an attractive force generated between the approaching portion and the magnetic poles of the magnet when the power is not supplied. 11. A column-shaped magnet magnetized in a diameter direction and reciprocatingly rotating, a coil for applying a rotational force to the magnet, a cylindrical yoke provided around the coil and made of a magnetic material, and the magnet Wherein the yoke is provided with a slit on the yoke where magnetic concentration occurs outside the operating range of the magnet, further comprising a means for transmitting the rotational force of the magnet and a means for regulating the operating range of the magnet. A yoke for providing the operating range of the magnet so as to include a vertical line substantially perpendicular to the magnetic pole direction of the magnet when the magnetic pole of the magnet is located at a stable position, and forming the slit when the coil is not energized. An electromagnetic drive device wherein the magnetic poles of the magnet are held at both ends of the operating range by an attractive force generated between an end face and the magnetic poles of the magnet. 12. A magnet in the form of a column that is magnetized in a diametric direction and reciprocates and rotates, a coil for applying a rotational force to the magnet, one yoke provided around the coil and made of a magnetic material, In an electromagnetic drive device including a means for transmitting a rotational force and a means for regulating an operating range of the magnet, an approach in which the distance between the magnet and the yoke is minimized and magnetic concentration occurs outside the operating range of the magnet. Part is provided by the yoke, a slit in which magnetic concentration occurs is provided in the yoke, and furthermore, when the magnetic pole of the magnet is positioned at the most magnetically stable position, it is substantially perpendicular to the magnetic pole direction of the magnet. The operating range of the magnet is provided so as to include a direction line, and an attractive force generated between the approach portion and the magnetic pole of the magnet and / or the slit is formed when the coil is not energized. An electromagnetic drive device wherein the magnetic poles of the magnets are held at both ends of the operating range by an attractive force generated between a yoke end surface and the magnetic poles of the magnets. 13. The electromagnetic driving device according to claim 12, wherein the slit is provided in the approach portion. 14. A coil frame comprising upper and lower two frames installed around the magnet for winding the coil, and at least the coil frame for installing the approaching portion or the slit at a predetermined position. 11. A positioning means is provided between one of the first and second yokes.
13. The electromagnetic drive device according to any one of claims to 12. 15. An outer peripheral surface extending along the inner wall of the yoke including at least the approach portion and its periphery is provided on at least the yoke on one of the upper and lower coil frames, and the yoke and the coil frame are fitted. The electromagnetic drive device according to any one of claims 10, 12, 13, and 14, wherein positioning of the approaching portion is performed by combining them. 16. The coil frame comprising the upper and lower frames is provided with at least two protrusions, and the yoke is provided with at least two recesses, and the protrusions and the recesses are fitted to each other. 15. The electromagnetic drive device according to claim 11, wherein positioning of the slit is performed by positioning means.