JP2006215324A - Light quantity adjustment device and optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light quantity adjustment device reduced in thickness in the direction of an optical axis. <P>SOLUTION: The light quantity adjustment device includes: a permanent magnet 1 whose peripheral face is magnetized and which is rotatable around a rotation shaft 2; a light quantity adjustment member 3 in the form of a thin plate, which extends perpendicular to the rotation shaft and is attached so as to be rotatable integrally with the permanent magnet; a stator yoke 6 disposed along the peripheral face of the permanent magnet with a space left between them; and a bobbin 5 around which a coil 4 for exciting the stator yoke is wound. The light quantity adjustment device rotates the light quantity adjustment member by using a magnetic action exerted between the permanent magnet and the stator yoke excited. Parts of the bobbin 5 include bearing composing parts 5a and 5b supporting both ends 2b and 2a of the rotation shaft 2 so that the rotation shaft is rotatable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light amount adjusting device such as a shutter device and an optical apparatus such as a digital still camera including the light amount adjusting device.

2. Description of the Related Art Conventionally, there is known an electromagnetically driven shutter device that includes a moving magnet type electromagnetic drive means and uses the moving magnet type electromagnetic drive means as a drive means such as a shutter blade (Patent Document 1). In contrast to this type of moving magnet type electromagnetic drive means, a structure in which the electromagnetic drive means is miniaturized by using a magnet rotor using a high magnetic material such as a neodymium (Nd-Fe-B) magnet as a permanent magnet in recent years. Things have been proposed.
Japanese Patent Laid-Open No. 5-216090

  However, there is an increasing demand not only for miniaturization of the electromagnetic driving means but also for miniaturization (thinning) of the entire light amount adjusting device such as a shutter device provided with the electromagnetic driving means. In recent years, products such as a video camera and a still camera that require a light amount adjusting device are strongly required to be reduced in size and thickness, and inevitably there is a demand for reducing the light amount adjusting device in size and thickness. Specifically, the lens barrel that holds the optical member basically has a circular cross section centered on the optical axis, and the light amount adjusting device, autofocus, zoom, and other mechanisms are housed in the gap with the optical lens group. Therefore, there is a demand for these members to be housed in a cylinder as small as possible centered on the optical axis. Particularly, in the light amount adjustment device used in a digital still camera, the CCD or the like is imaged from the light amount adjustment device. Since the distance to the element and the distance to the drive source for autofocus and zoom are close, there has been a strong demand for reducing the dimension (height) of the light amount adjusting device in the optical axis direction.

(Object of invention)
An object of the present invention is to provide a light amount adjusting device and an optical apparatus that achieve a reduction in thickness in the optical axis direction.

  In order to achieve the above object, the present invention according to claim 1 is characterized in that an outer peripheral surface is magnetized, a permanent magnet that is rotatable about a rotation axis, and extends in a direction perpendicular to the rotation axis, the permanent magnet A thin plate-shaped light amount adjusting member attached to be rotatable integrally with the stator, a stator yoke disposed with a gap on the outer peripheral surface of the permanent magnet, and a bobbin around which a coil for exciting the stator yoke is wound. A light amount adjusting device for rotating the light amount adjusting member using a magnetic action generated between the stator yoke to be excited and the permanent magnet, wherein both ends of the rotating shaft are formed on a part of the bobbin. The light quantity adjusting device is provided with a bearing component that is rotatably supported.

  Similarly, in order to achieve the above object, the present invention according to claim 2 is provided with a fixing attachment portion for fixing the light amount adjusting device to a fixing member in a part of the bobbin. This is a light quantity adjusting device.

  Similarly, in order to achieve the above object, the present invention according to claim 3 includes the light amount adjusting device according to claim 1 or 2 in a lens barrel, and the light amount adjusting member provided in the light amount adjusting device includes: The optical device adjusts the amount of light that moves forward and backward with respect to the optical path in the lens barrel and passes through the lens barrel.

  ADVANTAGE OF THE INVENTION According to this invention, the light quantity adjustment apparatus or optical apparatus which achieved thickness reduction of the optical axis direction can be provided.

  The best mode for carrying out the present invention is as shown in Example 1 and Example 2 described below.

  FIG. 1 is an exploded perspective view showing a shutter device according to Embodiment 1 of the present invention. In the figure, a permanent magnet 1 is made of a high magnetic material such as a neodymium-based (Nd-Fe-B) magnet and has a cylindrical shape whose outer peripheral surface is magnetized to two poles (N pole and S pole). . The rotating shaft 2 includes shaft portions 2a and 2b and a body portion 2c having a substantially elliptical shape. A thin plate-like shutter blade 3 extending in the radial direction is coupled to one shaft portion 2b of the rotating shaft 2 by bonding or the like. It is integrated and constitutes a shutter blade with a rotating shaft. Then, the body portion 2 c of the rotating shaft 2 is fitted into an elliptical shaft hole 1 a formed in the central portion of the permanent magnet 1 so that they are integrated.

  The electromagnetic coil 4 is wound around a bobbin 5 described later and energizes a stator yoke 6 described later when energized.

  The bobbin 5 has bearing components 5a and 5b that support the rotating shaft 2, and bearing holes 5c and 5d are formed in these bearing components 5a and 5b. Of the bearing components 5a and 5b, one bearing component 5b is a fixed body, and the other bearing component 5a can be opened 90 degrees upward as shown in FIG. 1 with its root 5e as the center of rotation. It is. Dust-proof side walls 5f and 5g are provided around the bearing component 5a. Further, the bobbin 5 has a square hole 5 h into which a stator yoke 6 described later is inserted from a direction orthogonal to an optical axis (not shown) parallel to the rotation shaft 2. Further, the bobbin 5 has fixing mounting portions 5i and 5j. The stator yoke 6 has a magnetic pole portion 6a and a magnetic pole portion 6b arranged with a predetermined gap so as to sandwich the magnetized outer peripheral surface of the permanent magnet 1, and has a horseshoe shape as a whole.

  The permanent magnet 1, the shutter blade with a rotating shaft formed by integrating the shutter blade 3 and the rotating shaft 2, the electromagnetic coil 4, the bobbin 5, and the stator yoke 6 constitute a shutter device 10 that is an example of a light amount adjusting device. . The shutter device 10 is fixed as a fixing member (not shown) via fixing mounting portions 5 i and 5 j provided as a part of the bobbin 5. The fixing attachment portions 5i and 5j include through holes, positioning bosses and hooks. The positioning boss is a convex part that is inserted into the concave part of the mating member to regulate the position of each other. The hook has the same function as the positioning boss, and its shape is a key type. It means something. Further, the fixing mounting portions 5i and 5j may be provided on the opposite side (the back side in FIG. 1) in the drawing so as to overlap and be fixed to the stator yoke 6.

  Next, a procedure for assembling the shutter device 10 will be described.

  First, the shutter blade 3 is integrated with one shaft portion 2b of the rotation shaft 2 by bonding or the like to form a shutter blade with a rotation shaft. Next, the shaft hole 1 a formed in the central portion of the permanent magnet 1 is fitted into the body portion 2 c of the rotating shaft 2. Next, the bearing component 5a of the bobbin 5 is opened 90 degrees upward as shown in FIG. 1 with the root 5e as the center of rotation, that is, rotated 90 degrees clockwise, and in this state, the other shaft of the rotating shaft 2 is rotated. 2a is inserted into a bearing hole 5d formed in the bearing component 5b. Subsequently, the magnetic pole portion 6a side of the stator yoke 6 is inserted into the square hole 5h through a hollow portion (not shown) around which the electromagnetic coil 4 of the bobbin 5 is wound, and the bobbin 5 and the stator yoke 6 are integrated. Then, the bearing component 5a opened 90 degrees upward as described above is rotated counterclockwise with the root 5e as the center of rotation, closed in the state shown in FIG. 1, and fixed by means (not shown). At this time, one shaft portion 2b of the rotating shaft 2 is rotatably fitted in a bearing hole 5c formed in the bearing constituting portion 5a. Thereby, the permanent magnet 1, the shutter blade with rotating shaft, the bobbin 5, the electromagnetic coil 4 and the stator yoke 6 are integrated, and the assembly of the shutter device 10 is completed.

  The shutter device 10 assembled as described above is fixed to a fixing member (not shown) formed with an opening for allowing a light beam to pass through fixing mounting portions 5i and 5j provided on the bobbin 5. The

  When the electromagnetic coil 4 of the shutter device 10 is positively energized, for example, the stator yoke 6 is excited, and the repulsive force and the attractive force generated between the stator yoke 6 and the permanent magnet 1 act on the permanent magnet 1 to The permanent magnet 1 rotates. As the permanent magnet 1 rotates, the shutter blade 3 moves from one position to the other position, and the opening formed in the unillustrated fixing member is changed from the closed state to the open state, that is, the opening is opened to pass the light flux. Put it in a state to let it go. On the other hand, when the electromagnetic coil 4 is reversely energized, the permanent magnet 1 rotates in the opposite direction, and the shutter blade 3 moves to the other position along with this, and the opening is changed from the open state to the initial closed state. In other words, the opening is shielded from light.

  According to the first embodiment, the bearing constituent portions 5a and 5b that support both ends of the rotating shaft 2 serving as the rotation center of the cylindrical permanent magnet 1 are provided on a part of the bobbin 5 around which the electromagnetic coil 4 is wound, and the shutter. Since the fixing mounting portions 5i and 5j (mounting holes or positioning bosses and hooks) for fixing the device to a fixing member (not shown) are provided, conventionally mounting holes for mounting and fixing the bearings and shutter devices, etc. The base plate and the cover that are configured as described above can be eliminated, and the shutter unit that adjusts the light flux passing through the opening can be configured only by the shutter blade 3. Therefore, compared with the conventional shutter device, the dimension in the optical axis direction is shorter, that is, the shutter device 10 can be made thin.

  FIG. 2 is an exploded perspective view showing a shutter device according to Embodiment 2 of the present invention. The shutter device 20 in the second embodiment is different from the shutter device 10 shown in FIG. 1 only in the structure of the bobbin 15, and the other configuration is the same as that of the shutter device 10 in the first embodiment. Omitted.

  In FIG. 2, the bobbin 15 around which the coil 4 is wound is provided with a substantially oval bearing constituent portion 15a, 15b in parallel in a direction perpendicular to the rotary shaft 2, and rotates in the center. Bearing holes 15c and 15d for supporting the shaft portion 2b and the shaft portion 2a of the shaft 2 are formed. As shown in the drawing, chamfered portions 15e and 15f are formed in the bearing components 15a and 15b, and the rotary shaft 2 is connected to the bearing components 15a and 15b via the chamfered portions 15e and 15f as will be described later. Will be pushed into the bearing holes 15c and 15d. The bobbin 15 has a square hole 15 h into which the stator yoke 6 is inserted from a direction orthogonal to an optical axis (not shown) parallel to the rotation axis 2. Further, the bobbin 15 has fixing mounting portions 15i and 15j.

  Next, a procedure for assembling the shutter device 20 will be described.

  First, the shutter blade 3 is integrated with one shaft portion 2b of the rotation shaft 2 by bonding or the like to form a shutter blade with a rotation shaft. Next, the shaft hole 1 a formed in the central portion of the permanent magnet 1 is fitted into the body portion 2 c of the rotating shaft 2. Next, the shaft portions 2 b and 2 a of the rotating shaft 2 are inserted into the chamfered portions 15 e and 15 f formed in the bearing constituent portions 15 a and 15 b of the bobbin 15. At this time, since the dimension between the bearing component 15a and the bearing component 15b (dimension in the optical axis direction) is smaller than the dimension in the axial direction (dimension in the optical axis direction) of the rotating shaft 2, the chamfering is performed as described above. When the shaft portions 2b and 2a of the rotary shaft 2 are inserted into the portions 15e and 15f, the bearing component portion 15a is bent upward and the bearing component portion 15b is bent downward, and eventually the shaft portion 2b of the rotary shaft 2 is bent. Is fitted into the bearing hole 15c, and the shaft portion 2a of the rotary shaft 2 is fitted into the bearing hole 15d. When fitted in this way, the bearing components 15a and 15b return to the original parallel state and are in a state in which both ends of the rotary shaft 2 are rotatably supported. Subsequently, the magnetic pole portion 6a side of the stator yoke 6 is inserted into the square hole 15h through a hollow portion (not shown) around which the electromagnetic coil 4 of the bobbin 15 is wound, and the bobbin 15 and the stator yoke 6 are integrated. Thereby, the permanent magnet 1, the shutter blade with rotating shaft, the bobbin 15, the electromagnetic coil 4 and the stator yoke 6 are integrated, and the assembly of the shutter device 20 is completed.

  The shutter device 20 assembled as described above is fixed to a fixing member (not shown) having an opening through which a light beam passes through fixing mounting portions 15i and 15j provided on the bobbin 15. The

  When the electromagnetic coil 4 of the shutter device 20 is positively energized, for example, the stator yoke 6 is excited, and the repulsive force and the attractive force generated between the stator yoke 6 and the permanent magnet 1 act on the permanent magnet 1 to The permanent magnet 1 rotates. As the permanent magnet 1 rotates, the shutter blade 3 moves from one position to the other position, and the opening formed in the unillustrated fixing member is changed from the closed state to the open state, that is, the opening is opened to pass the light flux. Put it in a state to let it go. On the other hand, when the electromagnetic coil 4 is reversely energized, the permanent magnet 1 rotates in the opposite direction, and the shutter blade 3 moves to the other position along with this, and the opening is changed from the open state to the initial closed state. In other words, the opening is shielded from light.

  According to the second embodiment, the bearing components 15a and 15b that support both ends of the rotating shaft 2 serving as the rotation center of the cylindrical permanent magnet 1 are provided on a part of the bobbin 15 around which the electromagnetic coil 4 is wound, and further, the shutter. Since the fixing mounting portions 15i and 15j (mounting holes or positioning bosses and hooks) for fixing the device to a fixing member (not shown) are provided, conventionally mounting holes for mounting and fixing the bearing and shutter device, etc. The base plate and the cover that are configured as described above can be eliminated, and the shutter unit that adjusts the light flux passing through the opening can be configured only by the shutter blade 3. Therefore, compared with the conventional shutter device, the dimension in the optical axis direction is shorter, that is, the shutter device 20 can be made thin.

  FIG. 3 is a configuration diagram illustrating an outline of an imaging apparatus such as a digital camera including the shutter device 10 or 20 having the configuration of the first embodiment or the second embodiment.

  In FIG. 3, a long and narrow space 31 a is provided in a direction perpendicular to the optical axis 34 in a cylinder of a lens barrel 31 in which a plurality of lenses 32 are arranged. In the space 31a, the shutter device 10 or 20 having the configuration of the first embodiment or the second embodiment is disposed. In detail, the shutter blade 3 provided in the shutter device 10 or 20 moves back and forth with respect to the imaging optical path in the lens barrel 31 so that the amount of light passing through the plurality of lenses 32 in the lens barrel can be adjusted. Arranged in the space 31 a in the cylinder 31.

  As shown in FIG. 3, the position where the shutter device 10 or 20 is mounted in the lens barrel 31 is not only between the lenses 32 but also before each lens 32 or after each lens 32 and an image sensor such as a CCD. Any one before 33 may be used.

  As shown in FIG. 3, since the imaging device such as a digital camera includes the shutter device 10 or 20 that achieves a reduction in thickness, the imaging device may also be reduced in the optical axis direction. it can.

  In each of the above-described embodiments, the shutter blade 3 is used as an example of a thin plate-like light amount adjusting member that extends in a direction orthogonal to the rotation shaft 2 and is rotatably attached to the permanent magnet 1, but is not limited thereto. It may be a diaphragm blade or a light reducing member (ND (Neutral Density Filter) filter).

It is a disassembled perspective view which shows the structure of the shutter apparatus concerning Example 1 of this invention. It is a disassembled perspective view which shows the structure of the shutter apparatus concerning Example 1 of this invention. FIG. 2 is a configuration diagram illustrating an outline of a digital camera including a shutter device having the configuration of Example 1 or Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet 2 Rotating shaft 3 Shutter blade 4 Electromagnetic coil 5 Bobbin 5a, 5b Bearing component 5j, 5i Fixing attachment 6 Stator yoke 10 Shutter device 15 Bobbin 15a, 15b Bearing component 15j, 15i Fixing attachment 20 Shutter device 31 Lens barrel 31a Space where shutter device is arranged

Claims (3)

A permanent magnet whose outer peripheral surface is magnetized and rotatable about a rotation axis;
A thin plate-like light amount adjusting member that extends in a direction perpendicular to the rotation axis and is rotatably attached to the permanent magnet;
A stator yoke disposed with a gap on the outer peripheral surface of the permanent magnet;
A bobbin around which a coil for exciting the stator yoke is wound;
A light amount adjusting device for rotating the light amount adjusting member using a magnetic action generated between the stator yoke to be excited and the permanent magnet,
A light quantity adjusting device characterized in that a bearing component that rotatably supports both ends of the rotating shaft is provided on a part of the bobbin.   The light amount adjusting device according to claim 1, wherein a fixing attachment portion for fixing the light amount adjusting device to a fixing member is provided on a part of the bobbin. The light amount adjusting device according to claim 1 or 2 is provided in a lens barrel, and a light amount adjusting member provided in the light amount adjusting device advances and retreats with respect to an optical path in the lens barrel and passes through the lens barrel. An optical device characterized by adjusting the amount of light to be emitted.

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