JP2006072023A - Light quantity control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light quantity control unit capable of realizing miniaturization and making shutter speed higher by effectively utilizing magnetic flux generated in a coil. <P>SOLUTION: In the light quantity control unit, 1st and 2nd magnets 3 and 4 stuck to the turning base part 2a of a turning member 2 where a supporting part 2b is formed are magnetized so that one end side near to an aperture part 5a and the other end part side far from the aperture part 5a may have different magnetic poles from each other, and the coil 11 is disposed on a side where it is opposed to the 1st and the 2nd magnets 3 and 4, and is formed in the shape of an ellipse opposed to one end side and the other end side of the 1st and the 2nd magnets 3 and 4. By making the magnetic flux generated by energizing the coil 11 act on the magnetic flux having the different magnetic poles of the 1st and the 2nd magnets 3 and 4, the turning member 2 is turned with the supporting part 2b as a fulcrum, and a blade member 12 can shield the aperture part 5a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light amount adjustment device, and more particularly to a light amount adjustment device suitable for use in a digital movie camera, a digital still camera, or the like.

A conventional light amount adjusting device will be described based on Patent Document 1. As shown in FIGS. 4 and 5, a rectangular base plate 50 is formed with an opening 50 a having a predetermined aperture formed by a round hole. Yes. First and second blades 51 and 52 are slidably mounted on a plurality of slide rails 50a formed on the surface of the main plate 50.
A long hole 51 a is formed on one end (front side) of the first diaphragm blade 51, and a triangular diaphragm portion 51 b is formed on the other end (rear side), and one end portion of the second diaphragm blade 52 is formed. A long hole 52a is formed on the side, and a round-shaped throttle hole 52b is formed on the other end side.

Further, a cover 53 having a round hole-shaped opening 53 a is disposed on the first and second blades 51 and 52.
Pins 54a and 54b of the arm 54 are engaged with the long holes 51a and 52a of the first and second blades 51 and 52, respectively, and the arm 54 rotates to the right or left to make the first. The second blades 51 and 52 shield or open the openings 50b and 53a.
Further, a boss 50c is formed to protrude from the main plate 50, and a spring 55 is wound around the boss 50c. A rotation shaft 56 is inserted and supported in the hole 50d of the boss 50c, and a press-fitting hole 54c at the center of rotation of the arm 54 is fixed to the rotation shaft 56 by press-fitting or the like.

The rotating shaft 56 is sandwiched between a driving coil frame 58 having a driving coil 58a disposed inside a cylindrical yoke 57 and a braking coil frame 59 having a braking coil 59a, and a rotor magnet (see FIG. (Not shown) is attached.
Then, when the rotor magnet is driven, the rotating shaft 56 rotates, for example, counterclockwise, the arm 54 also rotates in the same direction, the first blade 51 slides in the arrow A direction, and the second blade 52 slides in the direction of arrow B opposite to the first blade 51. Accordingly, the aperture operation can be performed by narrowing the openings 50b and 53a by the aperture 51b and the aperture 52b.
Alternatively, the shutters can be operated with the openings 50b and 53a completely shielded.
Utility Model Registration No. 2502005

However, in the conventional light amount adjusting device as described above, the first and second blades 51 and 52 slide in a straight line in the direction of arrow A or arrow B. There was a problem of becoming horizontally long and large.
In addition, since the two coils 58a and 59a are disposed to rotationally drive the rotor magnet, there is a problem in that the drive portion becomes large and the entire apparatus becomes large. Further, since sliding friction occurs between the sliding first and second blades 51 and 52, when the shutter operation is performed with the first and second blades 51 and 52, the shutter speed varies. There is a problem that the shutter speed becomes slow.
The present invention is for solving the above-described problems, and provides a light amount adjustment device that can be miniaturized and can increase the shutter speed by effectively utilizing magnetic flux generated in a coil. Objective.

As a first means for solving the above problems, a light quantity adjusting device according to the present invention includes a base member having a blade sliding surface in which an opening having a predetermined aperture is formed, and placed on the blade sliding surface. A blade member that can be rotated in a direction to open and close the opening, and a rotation member that can rotate the blade member so that the opening can be opened and closed. A rotation support portion capable of rotatably supporting a moving member is formed, and the rotation member is formed with a support portion that can be supported by the rotation support portion, and the rotation member formed with the support portion. A magnet is fixed to the rotating base of the magnet, and the magnet is magnetized so that one end near the opening and the other end far from the opening have different magnetic poles. A coil is disposed on the opposite side of the coil. It is formed in a shape that can be opposed to the one end side and the other end side of the net, and the magnetic flux generated by energizing the coil becomes the magnetic flux of different magnetic poles on the one end side and the other end side of the magnet. By acting, the rotating member rotates about the support portion as a fulcrum, and the blade member can shield the opening.
Further, as a second solving means for solving the above-mentioned problem, the magnet includes a first magnet disposed on the one side of the rotation base sandwiching the support portion, and the other side of the rotation base. The first magnet is magnetized with one magnetic pole on the one end side and the other magnetic pole on the other end side, and the second magnet has the one end The other magnetic pole is magnetized on the part side and the one magnetic pole is magnetized on the other end part side, and the coil can be opposed to the one end part side and the other end part side of the first and second magnets. It is formed in the ellipse shape of the width dimension.
Further, as a third solving means for solving the above-mentioned problem, the rotating member is formed with a blade operating portion capable of rotating the blade member, and when the rotating member rotates, the blade The operation unit is configured to rotate the blade member.

Further, as a fourth means for solving the above problems, a blade support portion that rotatably supports the blade member is formed on the blade sliding surface, and the blade member includes the blade support. A support part that can be supported by the part and an operation part that can engage the blade operation part of the rotating member are formed.
Further, as a fifth means for solving the above problem, the base member is formed with a hollow holding portion capable of holding the turning member so as to be rotatable, and is bridged in the holding portion. A crosspiece having the rotation support portion is formed, and the first and second magnets are fixed to the one side and the other side of the rotation base with a predetermined gap with respect to the crosspiece. It is characterized by.

The magnet of the light quantity adjusting device of the present invention is magnetized so that one end side near the opening of the base member and the other end far from the opening have different magnetic poles, and a coil is placed on the side facing the magnet. The coil is formed in a shape that can be opposed to the one end side and the other end side of the magnet, and a magnetic flux generated by energizing the coil is one end side and the other end side of the magnet. By acting on the magnetic flux of different magnetic poles, the rotating member rotates about the support portion and the blade member can shield the opening, so that the magnetic flux generated by energizing the coil can be efficiently magnetized. It is possible to make the magnetic poles act on the magnetic flux and to increase the shutter speed at which the blade member shields the aperture book.
The first magnet has one magnetic pole on one end side and the other magnetic pole on the other end side, and the second magnet has one magnetic pole on the other end side and one magnetic pole on the other end side. Each of the magnetic poles is magnetized, and the coil is formed in an elliptical shape with a predetermined width dimension that can be opposed to one end and the other end of the first and second magnets. The generated light flux can be efficiently applied to the magnetic poles of the two magnets, and a light amount adjusting device that can be miniaturized can be provided.
Further, the rotation member is formed with a blade operation portion that can rotate the blade member. When the rotation member rotates, the blade operation portion rotates the blade member. The blade member can be reliably rotated by the rotation of the moving member.

In addition, a blade support portion that rotatably supports the blade member is formed on the blade sliding surface, and the blade member includes a support portion that can be supported by the blade support portion and a blade operation portion of the rotation member. Since the operation part which can be combined is formed, the blade member can be further reliably rotated.
In addition, the base member is formed with a hollow holding portion that can hold the turning member so as to be rotatable, and a bridge portion that is bridged in the holding portion and has a turning support portion is formed. Since the magnet is fixed to one side and the other side of the rotation base with a predetermined gap with respect to the crosspiece, the first and second magnets do not hit the crosspiece, and the rotation member Can be reliably rotated.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a light amount adjusting device according to the present invention will be described below with reference to FIGS. FIG. 1 is an exploded perspective view of the light amount adjusting device of the present invention, FIG. 2 is a plan view of the state where the top cover of FIG. 1 is removed, and FIG. 3 is a plan view of which the coil of FIG.

First, a bottom cover 1 having a circular outer shape, which is made of a magnetic material such as a steel plate, is disposed at the lowermost portion of the light amount adjusting device of the present invention.
The bottom cover 1 has an opening 1a at the center, and a substantially circular flat portion 1b is formed outside the opening 1a so that the outer shape is substantially donut-shaped.
Further, the bottom cover 1 has three positioning grooves 1c and one terminal escape portion 1d formed on the outer periphery of the flat portion 1b.

Further, a plate-like rotation member 2 made of a resin material is disposed on the flat portion 1b on the right side of the bottom cover 1 in the figure, and this rotation member 2 is formed with a rotation base portion 2a having a large area. In addition, a support portion 2b is projected and formed with a predetermined diameter size and a high size at the center portion which is the center of gravity of the rotation base portion 2a.
A first arm portion 2c is formed to extend in the left direction in the figure on one side of the rotation base portion 2a in the illustrated back side, and has a predetermined diameter and high dimension on the end side of the first arm portion 2c. A protruding blade operation portion 2d is formed.

A height dimension of the blade operation portion 2d is formed to be slightly higher than a height dimension of the support portion 2b, and a tip portion is inserted through a top cover 13 described later.
A second arm portion 2e is formed on the other side of the front side of the rotation base portion 2a so as to extend in the same direction as the first arm portion 2c.
A pair of first and second magnets 3, 4 are disposed on the rotation base 2 a of the rotation member 2, and the first magnet 3 is illustrated at the back of the rotation base 2 a with the support 2 b interposed therebetween. It is fixed to one side of the side with an adhesive or the like.

The second magnet 4 is fixed to the other side of the front side of the rotation base 2a sandwiching the support 2b with an adhesive or the like.
The first magnet 3 fixed to the rotating base 2a has one end near the opening 5a of the base member 5 to be described later as one magnetic pole, for example, an S pole, and the other end far from the opening 5a is the other magnetic pole. Is magnetized in the N pole.
Further, the second magnet 4 has a magnetizing direction opposite to that of the first magnet 3, and one end side close to an opening 5a of the base member 5 described later is the other magnetic pole, for example, the N pole, and the opening 5a. The other end portion far from the center is magnetized to the S pole which is one magnetic pole.
That is, the first and second magnets 3 and 4 are magnetized with different magnetic poles on one end side near the opening 5a of the base member 5 and on the other end side far from the opening 5a.

A base member 5 made of a resin material having an outer diameter substantially the same as that of the bottom cover 1 is disposed on the bottom cover 1 in a state where the rotating member 2 is placed on the flat portion 1b. The base member 5 is formed to a predetermined thickness.
An opening 5a having a predetermined diameter is formed at the center of the base member 5, and the periphery of the opening 5a is a flat blade sliding surface 5b.
On the blade sliding surface 5b, a first cover receiving portion 5c having a slightly higher height than the thickness of the blade member 12 described later is formed in a substantially horseshoe shape outside the opening 5a.

Further, a second cover receiving portion 5d having a height dimension from the blade sliding surface 5b that is the same as the first cover receiving portion 5c is protruded from the outer peripheral edge portion of the base member 5.
First, second, and third upper positioning portions 5e, 5f, and 5g capable of positioning a top cover 13, which will be described later, are formed at three substantially equidistant positions in the circumferential direction of the second cover receiving portion 5d. Has been.

The first, second, and third upper positioning portions 5e, 5f, and 5g are formed to be higher by a predetermined dimension than the second cover receiving portion 5d, and a top cover 13 to be described later can be positioned and fixed.
Also, lower positioning portions 5h to which the bottom cover 1 can be positioned and fixed are formed at three locations on the lower surface side of the base member 5 facing the first, second, and third upper positioning portions 5e, 5f, and 5g. ing. The lower positioning portion 5h is fitted in the positioning groove 1c of the bottom cover 1.

Between the right side of the first cover receiving portion 5c in the drawing and the second cover receiving portion 5d, a hollow and substantially fan-shaped holding portion 6 is formed so as to penetrate therethrough, and the holding portion 6 includes first and second upper positioning portions. 5e and 5f are formed and connected to the lower positioning portion 5h.
In addition, a crosspiece 7 having a predetermined width and thickness is formed in the holding portion 6 between the first and second upper positioning portions 5e and 5f, and the rotary member 2 is supported by the crosspiece 7. A rotation support portion 7a made of a hole capable of fitting and supporting the portion 2b is formed through.
Further, the boundary portion of the holding portion 6 where the inner wall surface 6a and the blade sliding surface 5b are in contact with each other is approximately the same height as the first, second, and third upper positioning portions 5e, 5f, and 5g. The formed blade support portion 8 is formed to protrude.

In such a base member 5, when the lower positioning portion 5 h is fitted in the positioning groove 1 c of the bottom cover 1 in a state where the rotating member 2 is placed on the flat portion 1 b, the support portion 2 b of the rotating member 2. Is fitted and supported by the rotation support portion 7 a of the crosspiece 7.
And the support part 2b fitted to the rotation support part 7a penetrates the rotation support part 7a, and the front-end | tip part can contact | abut the top cover 13 mentioned later.

Therefore, it is possible to prevent the rotating member 2 located in the holding portion 6 from being rattled in the vertical direction.
Further, since the crosspiece 7 is positioned between the first and second magnets 3 and 4 with a predetermined gap, the rotating member 2 has one side with the support 2b as a fulcrum. And the other side are rotatable in a seesaw shape.

Further, a terminal fixing portion 9 having a predetermined width and depth is engraved between the second and third upper positioning portions 5f and 5g of the base member 5, and the terminal fixing portion 9 has a coil to be described later. A terminal member 10 for energizing 11 can be fixed.
The terminal member 10 has a base portion 10a made of a resin material, and two terminals 10b are embedded in the base portion 10a by insert molding or the like. Then, the terminal 10b is drawn out of the base member 5.

In addition, one end of the first and second magnets 3 and 4 having a predetermined gap above the first and second magnets 3 and 4 of the rotating member 2 held by the holding unit 6. A coil 11 formed in a substantially elliptical shape with a predetermined width dimension that can be opposed to the side and the other end side is disposed.
The coil 11 is formed in a thin plate shape, and is fixed to the crosspiece 7 of the base member 5 with an adhesive or the like so that a predetermined gap is formed with respect to the first and second magnets 3 and 4. It has become.

A thin blade member 12 is placed on the blade sliding surface 5 b of the base member 5. The blade member 12 has a long groove shape that can be engaged with a round hole-shaped fitting support portion 12 a that can be fitted and supported on the blade support portion 8 of the base member 5 and a blade operation portion 2 d of the rotating member 2. The operation part 12b and the large shielding part 12c which can shield the opening part 5a are formed.
The blade member 12 has a thickness slightly smaller than the height of the first and second cover receiving portions 5c and 5d.

Further, a top cover 13 is provided on the second cover receiving portion 5d so as to cover the blade sliding surface 5b. The top cover 13 is made of a magnetic material such as an iron plate, and has an outer diameter dimension of the base member 5. It is formed in a circular shape having substantially the same size.
The top cover 13 has an opening 13a larger than the opening 5a of the base member 5 at the center, and is fitted to the first, second, and third upper positioning portions 5e to 5g of the base member 5 at the outer peripheral portion. The positioning grooves 13b that can be positioned together are formed at three locations.

The top cover 13 that is positioned by fitting the positioning groove 13b to the first, second, and third upper positioning portions 5e to 5g has a round hole 13c into which the blade support portion 8 can be inserted and fitted, and a rotation. Long holes 13d that can be slid by engaging with the blade operation portion 2d of the member 2 are formed to penetrate therethrough.
When the top cover 13 is positioned and placed on the first and second cover receiving portions 5c and 5d, a fine gap is formed between the blade member 12 located on the blade sliding surface 5b and the top cover 13. Thus, the blade member 12 is rotatable.
The top cover 13 and the bottom cover 1 are fixed to the base member 5 with an adhesive or the like.

The operation of the light quantity adjusting apparatus of the present invention will be described. First, the magnetic flux generated by applying a current in one direction to the coil 11 is changed to the magnetic flux of one of the first and second magnets 3 and 4 and the magnetic pole of the other magnetic pole. By acting, the rotating member 2 rotates, for example, in the clockwise direction with the support portion 2b as a fulcrum.
Then, the blade member 12 having the blade support portion 8 fitted and supported by the blade support portion 8 is rotated counterclockwise about the blade support portion 8 as a fulcrum by the blade operation portion 2d of the rotation member 2 and shielded. The part 12c rotates in a direction to shield the opening 5a.
Then, the shielding portion 12c completely shields the opening 5a and the shutter operation is performed.

  When performing a diaphragm operation that partially shields the opening 5a, a position detecting means (not shown) including a hall element or the like that can detect the amount of rotation of the rotation member 2 is disposed on the base member 5. When the position detecting means detects that the shielding portion 12c of the blade member 12 has narrowed the opening 5a by a desired amount, the movement of the rotating member 2 is locked by controlling the amount of current supplied to the coil 11 and the current supply direction. It is supposed to be.

In the light amount adjusting device of the present invention, the left and right sides of the coil 11 formed in a substantially elliptical shape with a predetermined width dimension are arranged on one end side and the other end where different magnetic poles of the first and second magnets 3 and 4 are magnetized. The magnetic flux generated from the left and right coils 11 when the coil 11 is energized is efficiently used as the magnetic flux of each magnetic pole of the first and second magnets 3 and 4. Can act.
That is, the magnetic flux generated in the coil 11 can be effectively used, and the rotating member 2 can be rotated at high speed.
Therefore, the rotation speed of the rotation member 2 can be increased, and the movement of the blade member 12 that shields the opening 5a can be increased to increase the shutter speed.

  Moreover, since the support part 6f which is a rotation fulcrum is formed in the center part which is a gravity center position of the rotation base 2a of the rotation member 2, even if an impact etc. are added from the outside, the rotation base 2a The balance is maintained between the one side and the other side, and the rotating member 2 can be prevented from rotating unnecessarily.

In the description of the embodiment of the present invention, the first and second magnets 3 and 4 are fixed to the rotation base 2a of the rotation member 2, but the first magnet 3 or the second magnet 4 is used. Only one of these may be fixed to the rotation base 2a.
Even in such a single magnet, the left and right sides of the coil 11 can be opposed to one end side and the other end side of the magnet, and the magnetic flux generated in the coil 11 acts on the magnetic flux of the magnetic pole of one magnet. Thus, the rotating member 2 can be rotated.

It is a disassembled perspective view of the light quantity adjustment apparatus of this invention. It is a top view in the state where the top cover of FIG. 1 was removed. It is a top view except the coil of FIG. It is a disassembled perspective view of the conventional light quantity adjustment apparatus. It is a disassembled perspective view of the conventional light quantity adjustment apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottom cover 2 Rotating member 2a Rotating base part 2b Support part 2d Blade | wing operation part 3 1st magnet 4 2nd magnet 5 Base member 5a Opening part 5b Blade sliding surface 6 Holding | maintenance part 7 Crosspiece 11 Coil 12 Blade member 13 Top cover

Claims (5)

  A base member having a blade sliding surface in which an opening having a predetermined diameter is formed; a blade member mounted on the blade sliding surface and capable of rotating in a direction to open and close the opening; and the opening A rotating member capable of rotating the blade member so that the blade member can be opened and closed, and the base member is formed with a rotating support portion capable of rotatably supporting the rotating member. A support portion that can be supported by the rotation support portion is formed on the member, and a magnet is fixed to the rotation base portion of the rotation member that forms the support portion, and the magnet is attached to the opening portion. The one end side near and the other end side far from the opening are magnetized so as to have different magnetic poles, and a coil is disposed on the side facing the magnet, and the coil is connected to the one end of the magnet. Formed in a shape that can be opposed to the side and the other end side, When the magnetic flux generated by energizing the magnet acts on the magnetic flux of the different magnetic poles of the magnet, the rotating member rotates about the support portion, and the blade member can shield the opening. A light amount adjusting device characterized by that.   The magnet includes a first magnet disposed on the one side of the rotating base with the support portion interposed therebetween, and a second magnet disposed on the other side of the rotating base, and the first magnet is One magnetic pole is magnetized on the one end side, and the other magnetic pole is magnetized on the other end side, and the second magnet has one magnetic pole on the one end side and one magnetic pole on the other end side. Each of the magnetic poles is magnetized, and the coil is formed in an elliptical shape having a predetermined width dimension that can be opposed to the one end side and the other end side of the first and second magnets. The light quantity adjusting device according to claim 1.   The rotating member is formed with a blade operating portion capable of rotating the blade member. When the rotating member rotates, the blade operating portion rotates the blade member. The light quantity adjusting device according to claim 1 or 2, wherein   A blade support portion that rotatably supports the blade member is formed on the blade sliding surface, and the blade member includes a support portion that can be supported by the blade support portion, and the blade of the rotation member. The light quantity adjusting device according to claim 3, wherein an operation portion that can be engaged with the operation portion is formed. The base member is formed with a hollow holding portion capable of holding the turning member so as to be rotatable, and a crosspiece having the turning support portion bridged in the holding portion is formed. 5. The second magnet according to claim 2, wherein the second magnet is fixed to the one side and the other side of the rotating base portion with a predetermined gap with respect to the crosspiece. The light quantity adjustment apparatus of description.

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