JP2006154054A - Shutter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shutter device that is small and thin, has excellent responsiveness, and obtains a large torque. <P>SOLUTION: In the shutter device 1, when power is supplied to a drive coil in a drive mechanism having outer rotor type stepping motor structure, a ring magnet 31 rotates and three shutter blades 5 rotate around a support shaft 50 in order to perform an opening/closing operation. In this case, the drive mechanism switches the shutter blades from an opened state to a closed state and vice versa by driving a stepping motor at not more than one step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shutter device used for a camera or the like.

In a shutter device used for optical devices such as various types of measurement and cameras, the shutter member is magnetically driven, for example, a two-pole magnetized cylindrical magnet is fixed to a rotating shaft to which the shutter member is fixed. On the other hand, a motor using a motor in which a pair of claw poles bent in a 90-degree angle range with a curvature facing the cylindrical magnet in parallel is fixed facing the upper and lower portions of the coil is proposed ( For example, see Patent Document 1).
JP-A-10-191613

  However, in the shutter device disclosed in Patent Document 1, since the shutter member is fixed to the rotating shaft, in order to prevent the motor main body portion from blocking the optical path, the motor main body is disposed on the side of the optical path. Therefore, there is a problem that a large space is required and it is difficult to reduce the size and thickness of the rotating shaft.

  Further, since it is necessary to magnetize the cylindrical magnet to two poles and drive the shutter member over a large angle range of 90 °, the response is poor and only a small torque can be obtained for the physique of the motor. There is a problem.

  In view of the above problems, an object of the present invention is to provide a shutter device that can be reduced in size and thickness.

  Another object of the present invention is to provide a shutter device that is excellent in responsiveness and can obtain a large torque.

  In order to solve the above-mentioned problems, in the present invention, in a shutter device having a shutter member for opening and closing an opening and a driving unit for driving the shutter member, the driving unit is arranged with the shutter member on the outside. An annular magnet, and a drive coil for rotating the annular magnet in the circumferential direction. Between the annular magnet and the shutter member, the rotation of the annular magnet is transmitted to the shutter member to cause the shutter member to move. A rotation transmitting portion that rotates in the in-plane direction of the shutter member is configured.

  In the present specification, the term “annular magnet disposed outside the shutter member” means that the entire shutter member or most of the shutter member is located inside the annular magnet, and surrounds the shutter member. In addition to the configuration in which the annular magnet is disposed, the configuration includes the configuration in which the outer peripheral side of the shutter member overlaps the annular magnet, and the configuration in which the outer peripheral side of the shutter member protrudes outside the annular magnet.

  In the present invention, since the inner shutter member is operated by rotating the annular magnet in the circumferential direction, the inner side of the annular magnet can be used as an optical path. Therefore, it is possible to reduce the size of the shutter device. Further, since the rotation of the annular magnet is transmitted to the shutter member without using the rotating shaft, the thickness can be reduced. Further, since the annular magnet is rotated in the circumferential direction to operate the inner shutter member, the shutter member can be constituted by a plurality of shutter blades supported by the support shaft so as to be rotatable in the in-plane direction. Such shutter blades are excellent in responsiveness and can function as a diaphragm.

  That is, in the present invention, the shutter member is composed of a plurality of shutter blades supported by a support shaft so as to be rotatable in an in-plane direction, and the plurality of shutter blades move from an open position to a closed position. When moving from the closed position to the open position, the center part is closed by rotating to the inside that overlaps each other deeply. It is preferable to operate.

  In the present invention, the annular magnet is multipolarly magnetized in the circumferential direction, and the driving means has a single phase provided with an annular yoke having a plurality of pole teeth arranged in the circumferential direction along the magnetized surface of the annular magnet. It is preferable to have a stepping motor structure. With this configuration, the number of poles can be increased, so that a large torque can be obtained and responsiveness can be improved.

  In the present invention, it is preferable that the driving means includes a set of the driving coil, the annular magnet, and the yoke. Since a large torque can be obtained by adopting a stepping motor structure, it is only necessary to use one set of the drive coil, the annular magnet, and the yoke, and the size, thickness, weight, and cost can be reduced. Can do.

  In the present invention, it is preferable that the shutter member moves from the open position to the closed position or from the closed position to the open position by an operation of less than one step in the driving unit. If comprised in this way, while being able to obtain a big torque, responsiveness can be improved. In addition, when the opening / closing operation is performed with less than one step in the driving means, the annular magnet stops at the middle position of the step angle, so it is not affected by the cogging torque, and thus rotates with good response. To do. Further, when the rotation angle is less than one step, even one coil and yoke can stably hold the stop position in each of the open position and the closed position.

  In the present invention, it is preferable that a stopper mechanism for defining a rotational movement range of the annular magnet and the shutter member is provided, and an operating angle range of the annular magnet is about ½ or less of an angle of the magnetic pole. If the operation is performed in such a narrow angle range, the rotation operation can be performed reliably.

  In the present invention, it is preferable that the multipolar magnetization of the annular magnet is performed with the rotation transmission portion as a reference position. If comprised in this way, a phase can be match | combined easily and reliably.

  In the present invention, the yoke is preferably formed with a protrusion or a recess for defining a fixed position in the circumferential direction. If comprised in this way, a phase can be match | combined easily and reliably.

  In the present invention, the drive means may be configured to have an outer rotor type stepping motor structure in which the annular magnet is disposed outside the yoke and the drive coil. Preferably, the drive coil has a taper that increases the inner diameter on the opening edge side at the inner peripheral portion on one side in the axial direction. If comprised in this way, since light is not interrupted by a yoke or a drive coil, light can be incident over a wide angle range from one side. Conversely, light can be emitted over a wide angle range from one side.

  In this invention, it is preferable that the said rotation transmission part is comprised by the edge part of the said shutter member, and the notch of the said annular magnet in which this edge part fits. If comprised in this way, since a shutter member is directly driven by an annular magnet, a mechanical transmission loss can be reduced and size reduction, weight reduction, and cost reduction can be achieved.

  In the present invention, a plurality of bearing balls are disposed between the annular magnet and a fixing member adjacent to the annular magnet, and at least one of the annular magnet and the fixing member includes the plurality of bearing balls. It is preferable that a plurality of bearing ball storage holes for holding each of these are formed. If comprised in this way, since the retainer with respect to a bearing ball is unnecessary, size reduction, weight reduction, and cost reduction can be achieved. Further, the reason why the configuration can be made without providing such a retainer is that the rotation angle is limited to one step or less.

  In this invention, it is preferable that the said bearing ball bears the function of both a thrust bearing and a radial bearing with respect to the said annular magnet. With this configuration, even if there is a manufacturing tolerance or deformation due to a temperature change, the load does not increase, so that a smooth operation can be realized.

  In the shutter device according to the present invention, since the annular magnet is rotated in the circumferential direction to operate the inner shutter member, the inside of the annular magnet can be used as an optical path. Therefore, it is possible to reduce the size of the shutter device. Further, since the rotation of the annular magnet is transmitted to the shutter member without using the rotating shaft, the thickness can be reduced. Further, since the annular magnet is rotated in the circumferential direction to operate the inner shutter member, the shutter member can be constituted by a plurality of shutter blades supported by the support shaft so as to be rotatable in the in-plane direction. Such shutter blades are excellent in responsiveness and can function as a diaphragm.

  A shutter device to which the present invention is applied will be described below with reference to the drawings.

(overall structure)
1A and 1B are a perspective view when the shutter device to which the present invention is applied is viewed from the upper surface side (one side), and when viewed from the bottom surface side (the other side) with the bottom surface cover removed, respectively. FIG. 2A and 2B are a sectional view of a shutter device to which the present invention is applied and a bottom view of an annular magnet used in the shutter device, respectively. In FIG. 2B, illustration of the shutter member is omitted.

  The shutter device 1 shown in FIGS. 1A and 1B is provided, for example, for a camera of a mobile phone. In the example shown here, one side 1a is the subject side and the other side 1b is on the other side 1b. A lens driving device (not shown) is arranged.

  As shown in FIGS. 2A and 2B, the shutter device 1 of the present embodiment has a cylindrical case 21, one side 1a of which is covered with a top cover 22, and the other side 1b is a bottom surface. Covered with a cover 23. Each of the top cover 22 and the bottom cover 23 has openings 220 and 230 formed at the center thereof, and an optical path from one side 1a to the other side 1b is secured. Inside the case 21, a ground plate 25 is disposed with a gap 6 between the bottom surface cover 23, and an opening 250 is also formed in the central portion of the ground plate 25. A ring 24 is fixed to the outer peripheral side of the bottom cover 23.

  In this embodiment, the driving mechanism 3 (driving means) of the outer rotor type one-phase stepping motor structure described below is configured using the upper surface and the outer side of the ground plate 25, and the space between the ground plate 25 and the bottom surface cover 23 is configured. A shutter member, which will be described later, is disposed using the gap 6.

(Configuration of drive mechanism)
In the drive mechanism 3, a cylindrical annular magnet 31 is disposed around the ground plate 25 so as to be rotatable in the circumferential direction, and the inner circumferential surface of the annular magnet 31 is magnetized in the circumferential direction so as to have an S pole. N poles are alternately arranged. Here, in the annular magnet 31, the angle of the magnetic pole is 18 °, for example, and 20 poles.

  Moreover, the drive mechanism 3 is provided with one drive coil 32 on the ground plate 25, and this drive coil 32 is wound in the circumferential direction. The drive coil 32 is disposed on the base plate 25 in a state of being sandwiched between an annular upper yoke 33 and an annular lower yoke 34 disposed on each of the upper end surface and the lower end surface thereof. From the outer peripheral edge of the upper yoke 33 and the outer peripheral edge of the lower yoke 34, a plurality of pole teeth 36, for example, ten pole teeth 36 protrude in the axial direction, and on the outer peripheral side of the drive coil 32, the upper yoke 33. The pole teeth 36 and the pole teeth 36 of the lower yoke 34 are alternately arranged in the circumferential direction. Therefore, when the drive coil 32 is energized, the pole teeth 36 of the upper yoke 33 and the pole teeth 36 of the lower yoke 34 are opposite to each other on the outer peripheral side of the drive coil 32. The number of poles of the annular magnet 31 is twice the number of pole teeth 36 of the upper yoke 33 (the number of pole teeth 36 of the lower yoke 34 is also 10 teeth), which is 20 poles in this embodiment.

  In this embodiment, the opening 220 of the top cover 22 has a larger diameter than the openings 230 and 250 of the bottom cover 23 and the base plate 25, and accordingly, the upper yoke 33 and the drive coil 32 are arranged in the axial direction. In the inner peripheral portion of one side 1a, tapers 330 and 320 for increasing the inner diameter on the opening edge side are provided. For this reason, the light is not blocked by the upper yoke 33 or the drive coil 32, so that the light can be incident over a wide angle range from the one side 1a.

(Support structure for annular magnet 31)
At the corner of the upper end surface of the annular magnet 31, there are a plurality of annular recesses having an annular outer peripheral wall 313 extending short in the axial direction and an annular bottom wall 314 extending short in the radial direction at substantially equal angular intervals in the circumferential direction. The plurality of spaces formed by the annular recess, the case 21 and the upper surface cover are used as bearing ball storage holes 82 in which one bearing ball 81 is arranged. In addition, annular recesses having an annular outer peripheral wall 315 that extends short in the axial direction and an annular bottom wall 316 that extends short in the radial direction are also provided at substantially equal angular intervals in the circumferential direction at the corners of the lower end surface of the annular magnet 31. A plurality of spaces formed by the annular recess, the case 21 and the ring 24 are used as bearing ball storage holes 84 in which one bearing ball 83 is arranged. Therefore, in this embodiment, since a retainer for the bearing balls 81 and 83 is not necessary, it is possible to reduce the size, the weight, and the cost. The bearing balls 81 and 83 are sandwiched between the bottom walls 314 and 316 and the ring 24 and function as a thrust bearing for the annular magnet 31, and are sandwiched between the outer peripheral walls 313 and 315 and the case 21 to the annular magnet 31. It functions as a radial bearing. For this reason, even if there is a manufacturing tolerance or a deformation due to a temperature change, the load does not increase, so that a smooth operation can be realized.

  Incidentally, the dimension in the circumferential direction of the bearing ball storage holes 82 and 83 is more than the dimension corresponding to the sum of the dimension of 1/2 of the operating angle of the annular magnet 31 described later and the outer diameter of the bearing balls 81 and 83. It is set to the dimension which added.

(Configuration of shutter member and rotation transmission unit)
In the shutter device 1 of the present embodiment, three thin shutter blades 5 are arranged as a shutter member between the base plate 25 and the bottom cover 23 so as to partially overlap each other. Each of the three shutter blades 5 is supported by the support shaft 50 so that the base end side thereof can rotate in the in-plane direction. The three shutter blades 5 have the same configuration, and all have a curved outer shape for the purpose of avoiding interference with the ground plane fixing boss 255.

  Here, a protrusion 51 is formed at each base end portion of the three shutter blades 5, while a notch 311 in which each protrusion 51 of the three shutter blades 5 fits is formed on the bottom surface of the annular magnet 31. Three are formed at equiangular intervals. Therefore, in this embodiment, when the opening / closing operation described later is performed between the annular magnet 31 and the three shutter blades 5 by the projection 51 and the notch 311, the rotation of the annular magnet 31 is performed by the three shutter blades. A rotation transmitting portion 9 is configured to transmit the three shutter members 5 in the in-plane direction. The notch 311 is wide on the inner peripheral side corresponding to the shape of the protrusion 51 and narrows toward the outer peripheral side.

(Operation)
FIGS. 3A and 3B are a bottom view of the shutter device to which the present invention is applied, with the shutter opened, and a bottom view of the shutter closed. In FIGS. 3 (a) and 3 (b), illustration of bearing balls and their storage holes is omitted.

  In the shutter device 1 of the present embodiment, in the state shown in FIG. 3A, the three shutter blades 5 are in a state of rotating and moving toward the inside where they are deeply overlapped with each other, and the central portion thereof is closed ( Closed). When the drive coil 32 is energized from this state, the annular magnet 31 rotates in the direction indicated by the arrow A. As a result, the three shutter blades 5 rotate around the support shaft 50 in the direction of arrow B. That is, as shown in FIG. 3B, the three shutter blades 5 are rotationally moved in the outer direction where the overlapping of each other becomes shallow, and the central portion is opened (open state).

  3B, when the drive coil 32 is energized in the reverse direction, the annular magnet 31 rotates in the direction indicated by the arrow C. As a result, the three shutter blades 5 rotate around the support shaft 50 in the direction of the arrow D. That is, as shown in FIG. 3A, the three shutter blades 5 are rotationally moved in the inward direction where the overlap between them becomes deep, and the central portion is closed (closed state).

  Here, since the support shaft 50 is supported on the base end side of the three shutter blades 5, the three shutter blades 5 can be greatly displaced by a slight rotation of the annular magnet 31. For this reason, the drive mechanism 3 is switched from the open state to the closed state and from the closed state to the open state by driving in one step or less in the stepping motor. For example, in this embodiment, the step angle is 9 ° (40 steps per rotation), and the opening / closing operation can be performed at an operation angle of 6 °.

  In this embodiment, when the above-described opening / closing operation is performed, if the three shutter blades 5 move inward (in the closing direction), the three shutter blades 5 interfere with each other as shown in FIG. Further movement is restricted. On the other hand, when the three shutter blades 5 move outward (in the opening direction), the outer peripheral edge of the three shutter blades 5 contacts the inner peripheral surface of the annular magnet 31 as shown in FIG. And further movement is restricted. In this embodiment, the stopper mechanism that defines the rotational movement range of the annular magnet 31 and the shutter blade 5 is configured in this way, and the operating angle range (6 °) of the annular magnet 31 is reduced by the stopper mechanism. It is set to about ½ or less of the angle (18 °).

(Main effects of this form)
As described above, in the shutter device 1 of this embodiment, the inner side of the annular magnet 31 can be used as an optical path since the inner shutter blade 5 is operated by rotating the annular magnet 31 in the circumferential direction. Miniaturization can be achieved. Further, since the rotation of the annular magnet 31 is transmitted to the shutter blades 5 without using the rotation shaft, the thickness can be reduced. Further, since the annular magnet 31 is rotated in the circumferential direction to operate the inner shutter blade 5, the shutter blade 5 is constituted by a plurality of shutter blades 5 supported by the support shaft 50 so as to be rotatable in the in-plane direction. Such a shutter blade 5 is excellent in responsiveness. Further, if the shutter blade 5 is stopped at an intermediate position between the open position and the closed position, a substantially circular small opening can be formed, so that it can function as a diaphragm.

  Further, in this embodiment, since the outer rotor type one-phase stepping motor structure is adopted as the drive mechanism 3, the number of poles can be increased to an arbitrary number, so that a large torque can be obtained. Moreover, in this embodiment, the drive mechanism 3 moves the shutter blade 5 from the open position to the closed position and from the closed position to the open position by an operation of less than one step in the stepping motor. For this reason, large torque can be obtained and responsiveness can be improved. In addition, when the opening / closing operation is performed with an operation of less than one step in the drive mechanism 3, the annular magnet 31 stops at a midpoint of the step angle, and therefore is not affected by the cogging torque. Rotate.

  In this embodiment, the drive device is composed of a set of drive coil 32, annular magnet 31, upper yoke 33, and lower yoke 34, so that the size, thickness, weight and cost can be reduced. Can do.

  In this embodiment, the notch 311 of the annular magnet 31 and the projections 51 of the three shutter blades 5 constitute the rotation transmission unit 9 that transmits the rotation of the annular magnet 31 to the shutter blades 5. Therefore, the shutter blade 5 can be directly driven by the annular magnet 31. Therefore, transmission loss can be reduced, and size reduction, weight reduction, and cost reduction can be achieved.

(Other embodiments)
In the above embodiment, the rotation transmitting portion 9 is configured by using the notch 311 of the annular magnet 31, so that if the magnetic pole of the annular magnet 31 and the notch 311 are misaligned, there is a problem in the operation of the shutter blade 5. appear. Therefore, it is preferable that the multipolar magnetization of the annular magnet 31 is made with the notch 311 constituting the rotation transmitting portion as a reference position. If comprised in this way, a phase can be match | combined easily and reliably.

  Further, if the fixing positions in the circumferential direction of the upper yoke 33 and the lower yoke 34 are shifted, a problem occurs in the operation of the shutter blade 5. Accordingly, protrusions or recesses for controlling the fixing position in the circumferential direction are formed on the upper yoke 33 and the lower yoke 34, and the upper yoke 33 and the lower yoke 34 are formed on the base plate 25, the case 21, and the upper surface cover 22, respectively. It is preferable to form a recess or projection that engages with the projection or recess of the yoke 34 so that the phase can be adjusted easily and reliably.

  In the above embodiment, the rotation transmission unit 9 is configured by the notch 311 of the annular magnet 31 and the projection 51 of the shutter blade 5. May be configured.

  Further, instead of the structure in which the annular magnet 31 is supported by the bearing balls 81 and 83, a lubricating layer or the like may be formed on the sliding surface.

  In the above embodiment, the support shaft 50 and the ground plane fixing boss 255 are provided separately, but they may be shared.

  In the above embodiment, both the opening operation and the closing operation are configured to be magnetically driven by the drive mechanism 3. However, for the operation in one direction, the biasing force of the spring is used, and the magnetic driving is performed in the operation in the other direction. You may employ | adopt the structure to do.

  In the above embodiment, the configuration in which the annular magnet 31 is disposed so as to surround the shutter blade 5 is adopted. However, the entire shutter blade 5 or most of the shutter blade 5 may be located inside the annular magnet 31. A configuration in which the outer peripheral side of 5 partially overlaps the annular magnet 31 or a configuration in which the outer peripheral side of the shutter blade 5 protrudes outside the annular magnet 31 may be employed. Further, the number of shutter blades 5 may be other than three, and can be increased or decreased as necessary.

(A), (b) is a perspective view when the shutter device to which the present invention is applied is viewed from the top surface side (one side), and a perspective view when the shutter device is viewed from the bottom surface side (the other side) with the bottom cover removed. FIG. (A), (b) is respectively sectional drawing of the shutter apparatus to which this invention is applied, and a bottom view of the annular magnet used for this shutter apparatus. (A), (b) is the bottom view of the state which opened the shutter in the shutter apparatus to which this invention is applied, respectively, and the bottom view of the state which closed the shutter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter apparatus 3 Drive mechanism (drive means)
5 Shutter blade (shutter member)
9 Rotation transmitting portion 25 Ground plate 31 Annular magnet 32 Drive coil 33 Upper yoke 34 Lower yoke 36 Upper yoke and lower yoke pole teeth 81, 83 Bearing balls 82, 84 Bearing ball receiving hole 50 Support shaft 51 Projection 311 of shutter blades Annular magnet Notches 320, 330 taper

Claims (12)

In a shutter device having a shutter member for opening and closing an opening, and a driving means for driving the shutter member,
The drive means includes an annular magnet disposed outside the shutter member, and a drive coil that rotates the annular magnet in the circumferential direction,
Between the annular magnet and the shutter member, there is configured a rotation transmitting portion that transmits the rotation of the annular magnet to the shutter member and rotates the shutter member in the in-plane direction of the shutter member. A shutter device characterized by the above. In Claim 1, the shutter member is composed of a plurality of shutter blades supported by a support shaft so as to be rotatable in an in-plane direction.
The plurality of shutter blades rotate and move inward to overlap each other when moving from the open position to the closed position to close the central portion, and overlap each other when moving from the closed position to the open position. The shutter device is characterized in that the central portion is opened by rotating and moving outward in a direction in which the depth becomes shallower. In Claim 1 or 2, the annular magnet is multipolarly magnetized in the circumferential direction,
The shutter device has a one-phase stepping motor structure provided with an annular yoke having a plurality of pole teeth arranged in a circumferential direction along a magnetized surface of the annular magnet.   4. The shutter device according to claim 3, wherein the driving unit includes a set of the driving coil, the annular magnet, and the yoke.   5. The shutter device according to claim 3, wherein the shutter member moves from the open position to the closed position or from the closed position to the open position by an operation of less than one step in the driving unit. . In any one of Claims 3 thru | or 5, It has a stopper mechanism which prescribes | regulates the rotational movement range of the said annular magnet and the said shutter member,
The operating angle range of the annular magnet is about ½ or less of the angle of the magnetic pole.   7. The shutter device according to claim 3, wherein the multipolar magnetization of the annular magnet is performed with the rotation transmission portion as a reference position.   8. The shutter device according to claim 3, wherein the yoke has a protrusion or a recess for defining a fixed position in the circumferential direction. 9. The drive unit according to claim 3, wherein the drive means has an outer rotor type stepping motor structure in which the annular magnet is disposed outside the yoke and the drive coil.
The yoke device and the drive coil have a taper that increases an inner diameter on the opening edge side at an inner peripheral portion on one side in the axial direction.   10. The shutter device according to claim 1, wherein the rotation transmission portion is configured by an end portion of the shutter member and a notch of the annular magnet into which the end portion is fitted. In any one of Claims 1 thru | or 10, A some bearing ball is arrange | positioned between the said annular magnet and the fixing member adjacent to this annular magnet,
At least one of the annular magnet and the fixing member is formed with a plurality of bearing ball storage holes for holding the plurality of bearing balls.   The shutter device according to claim 11, wherein the bearing ball serves as both a thrust bearing and a radial bearing with respect to the annular magnet.

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