JP5183898B2 - Electromagnetic actuator and camera blade drive device using the same - Google Patents

Description

  The present invention uses an electromagnetic actuator that reciprocally rotates a rotor having a permanent magnet by energization of a stator coil wound around a substantially U-shaped yoke, and at least 1 using the electromagnetic actuator. The present invention relates to a camera blade drive device that reciprocates a single blade.

A rotor having a permanent magnet magnetized in the radial direction, and a base portion and two leg portions extending long from the base portion are substantially U-shaped, and the tip ends of the two leg portions are used as magnetic pole portions. At least one yoke opposed to the circumferential surface of the rotor, and flange portions having a predetermined thickness at both ends in the axial direction of the hollow shaft portion, and a coil is wound around the outside of the hollow shaft portion the cage hollow shaft portion provided with a bobbin which is fitted on one leg of the yoke, but the electromagnetic actuator is known in which the rotor so as to reciprocally rotate through energization control to the coil, this type These electromagnetic actuators are advantageous for use in equipment that requires thinning, and are therefore considered to be optimal as drive sources for various blades and lenses used mainly in cameras. ing.

  The following Patent Document 1 includes an electromagnetic actuator having a bobbin fitted to one yoke, and a rotor magnetized in two poles in the radial direction conflicts with two shutter blades. A configuration that reciprocates in the direction and a configuration that reciprocates one aperture blade are described. Patent Document 2 below includes an electromagnetic actuator in which a common bobbin is fitted to two superimposed yokes, and a rotor magnetized in two poles in the radial direction has 2 A configuration is described in which the shutter blades are reciprocated in opposite directions. Further, Patent Document 3 below includes an electromagnetic actuator in which bobbins are respectively fitted to two yokes arranged so as to sandwich the rotor, and a rotor magnetized in four poles in the radial direction is provided. A configuration in which six diaphragm blades are reciprocated in the same direction is described.

JP 2005-241866 A JP 2004-95703 A JP 2005-284102 A

  In recent years, devices such as cameras that employ the electromagnetic actuator have been remarkably reduced in size. Therefore, further miniaturization is required for the configuration of the electromagnetic actuator. In order to reduce the size of this type of electromagnetic actuator, it is conceivable to shorten the leg portion of the yoke requiring a large arrangement space as much as possible. However, shortening the leg portion inevitably shortens the hollow shaft portion of the bobbin, so that there is a problem that the number of turns of the coil is reduced by that amount and the driving force is reduced.

  The present invention has been made to solve such problems, and the object of the present invention is to reduce the length of a bobbin when attempting to shorten the leg of the yoke in the electromagnetic actuator configured as described above. It is an object of the present invention to provide an electromagnetic actuator that can reduce the length of the hollow shaft portion by a corresponding amount, and a camera blade drive device that uses the electromagnetic actuator as a drive source.

In order to achieve the above-mentioned object, the present invention has a substantially U-shape comprising a rotor having a permanent magnet magnetized in the radial direction, and a base and two legs extending long from the base. At least one yoke facing the circumferential surface of the rotor with the tips of the two legs as magnetic poles, and a hollow shaft portion and two flange portions formed at both ends of the hollow shaft portion. It includes organic and at least one bobbin to fit the hollow shaft portion in one leg of the yoke, and a coil wound around the outer periphery of the hollow shaft portion be between two flanges of the bobbin , the flange portion of the person serving as the base side of the yoke when fitted to the hollow shaft portion on one of the legs of the yoke, the bottom surface becomes a bottom surface and side surfaces and said base side of said yoke made towards thinner and the yoke wall thickness than other portions of the flange portion of the The flange portion of the person as a base side are formed so as to be recessed in the direction of the flange portion on the opposite side of the base of the yoke when the hollow shaft portion is fitted to one leg of the yoke When the hollow shaft portion is fitted to one leg portion of the yoke, the bottom portion of the counterbore portion is fitted to the base portion of the fitted yoke. The side surface of the counterbore part in contact with the surface of the counterbore part facing the bottom surface, and the side surface of the counterbore part is the bottom surface of the counterbore part of the base part of the yoke to so that to contact the side surface of the surface facing the.

Further, in the bobbin , when the hollow shaft portion is fitted to one leg portion of the yoke, the flange portion on the base side of the yoke has the counterbore portion at the place where the counterbore portion is formed. A cutout portion is formed so that the base portion can contact the coil instead of the portion, and when the hollow shaft portion is fitted to one leg portion of the yoke, the yoke in the hollow shaft portion is A part of the end surface on the base side abuts a surface of the part of the base portion of the fitted yoke that faces the end surface on the base side of the yoke in the hollow shaft portion, and the notch portion , in some of the base portion of the fitted the said yoke, when a so that to contact the side surface of the surface facing the end surface of the base portion side of the yoke in the hollow shaft, is more effective.

  Further, the rotor is practically disposed between two plate-like members and is rotatably attached to a shaft provided on one of them, and further, If the bobbin is integrally formed with one of the plate-like members using a synthetic resin, it is advantageous in terms of cost.

  And a ground plate having an opening for exposure, at least one blade attached to the ground plate so as to reciprocate in order to advance and retreat to the exposure opening, and a drive source for reciprocating the blade. If the driving source is any one of the electromagnetic actuators described above, an extremely suitable camera blade driving device can be obtained.

The present invention is substantially U-shaped with a rotor having a permanent magnet magnetized in the radial direction, and a base portion and two leg portions extending long from the base portion, and tips of the two leg portions. at least one yoke and a hollow shaft portion and the hollow shaft portion two flanges perforated by a hollow shaft portion and the yoke formed at both ends of which are opposed to the peripheral surface of the rotor as a magnetic pole portion In the electromagnetic actuator comprising: at least one bobbin fitted to one leg of the coil; and a coil wound between the two flanges of the bobbin and wound around the outer periphery of the hollow shaft . the flange of the person serving as the base side of the yoke when the hollow shaft portion of the flange portion is fitted to one leg of the yoke, the base of the bottom surface becomes a bottom surface and side surfaces the yoke than other sites in the flange portion of the person who made a side The thickness thin and the flange portion of the person as a base portion side of the yoke be formed as recessed in the direction of the flange portion opposite was fitted to the hollow shaft portion on one of the legs of the yoke Sometimes the yoke has a counterbore portion into which a part of the base portion is fitted , and when the hollow shaft portion is fitted to one leg portion of the yoke, the bottom surface of the counterbore portion is A portion of the base portion of the yoke that is fitted in contact with a surface of the counterbore portion that faces the bottom surface, and the side surface of the counterbore portion is a part of the base portion of the yoke that is fitted. In this case, the leg portion of the yoke can be shortened while ensuring the desired length of the hollow shaft portion. Further, when a notch portion is formed instead of the spot facing portion and the hollow shaft portion is fitted to one leg portion of the yoke, a part of the end surface on the base side of the yoke in the hollow shaft portion is A portion of the base portion of the fitted yoke that contacts a surface of the hollow shaft portion that faces the end surface of the yoke on the base side, and the notch portion of the fitted yoke is If a portion of the base is in contact with the side surface of the hollow shaft portion that faces the end surface of the yoke on the base side , the leg portion of the yoke can be further shortened.

  The embodiment of the present invention will be described with reference to two examples. 1 to 3 are for explaining the first embodiment, and FIG. 4 is for explaining the second embodiment. FIG. 5 shows a conventional example so as to be easily compared with the first embodiment.

  This embodiment is configured as a shutter device for a digital camera built in an information terminal device suitable for carrying. FIG. 1 is a plan view of the shutter device as viewed from the subject side, FIG. 2 is a cross-sectional view showing the overlapping relationship of the members shown in FIG. 1, and FIG. It is the perspective view which showed the shape of the frame clearly. In FIG. 1, a part of the base plate 1 is cut away so that the cover plate 2 can be seen.

  First, the configuration of this embodiment will be described. The ground plane 1 is made of a synthetic resin and has a substantially rectangular planar shape. However, as can be seen from FIG. 2, both sides have a complicated shape. As shown in FIG. 1, the base plate 1 is formed with a circular opening 1a for a photographing optical path, and an arc-shaped long hole 1b is formed at an upper left direction position thereof. ing. Further, the cover plate 2 constituting the blade chamber with the base plate 1 is formed with an opening 2a having a slightly larger diameter than the opening 1a at a position facing the opening 1a. A long hole 2b having substantially the same shape is formed at a position facing the long hole 1b.

  In addition to the blade shaft 1c and the two stopper shafts 1d and 1e, a plurality of mounting shafts 1f are erected on the surface of the base plate 1 on the blade chamber side. Of these, the tips of the blade shaft 1c and the two stopper shafts 1d and 1e are inserted into holes formed in the cover plate 2, respectively. Further, only two of the plurality of mounting shafts 1f are shown in FIG. 2, but they have a cylindrical shape before assembling, and are attached to the holes of the cover plate 2 at the time of assembling. And the cover plate 2 is attached by deforming the tip into a bowl shape by hot melting. In the blade chamber configured as described above, the shutter blade 3 having the long hole 3a is rotatably attached to the blade shaft 1c.

  The base plate 1 is provided with a rotor shaft 1g and two mounting shafts 1h and 1i on a surface opposite to the blade chamber, and components of the electromagnetic actuator are mounted on these mounting shafts. Yes. The electromagnetic actuator of the present embodiment is a current control type motor that rotates a rotor having a permanent magnet in a direction corresponding to the energizing direction of the stator coil only within a predetermined angle range. The motor is configured to include only one yoke having a substantially U shape.

  Therefore, first, the rotor 4 of this embodiment has a cylindrical permanent magnet 4a magnetized in two poles in the radial direction and is rotatably attached to the shaft 1g. In FIG. 2, the boundary of the magnetic pole is indicated by a one-dot chain line. A synthetic resin arm 4b that is integrated with the permanent magnet 4a and projects in the radial direction is provided with a drive pin 4c at the tip thereof. The drive pin 4 c is inserted into the blade chamber through the long hole 1 b and fitted into the long hole 3 a of the shutter blade 3, and the tip thereof is inserted into the long hole 2 b of the cover plate 2. Although the permanent magnet 4a of the present embodiment is formed in a cylindrical shape, it is formed in a substantially columnar shape so that the centers of both end surfaces thereof are supported by the base plate 1 and a stator frame 5 described later. May be. As is well known, the entire rotor 4 may be made of permanent magnets.

The stator frame 5 of the present embodiment is made of synthetic resin, and has holes 5a and 5b for inserting the mounting shafts 1h and 1i at positions near both ends in the length direction thereof. A bobbin portion 5c is formed between them. The bobbin portion 5c includes a hollow shaft portion 5c-1 and two flange portions 5c-2 and 5c-3 formed at both ends thereof. A coil 6 is wound. FIG. 3 is a perspective view of the stator frame 5 in the state where the coil 6 is wound around the hollow shaft portion 5c-1 as viewed from the lower right front position of FIG. As can also be seen, the flange portion 5c-3 of this embodiment is provided with a notch portion 5c-4 that is partially cut away, and the coil 6 overlaps and is hollow only from the notch portion 5c-4. The end surface of the shaft portion 5c-1 can be seen.

  Further, the yoke 7 of the present embodiment is formed in a substantially U shape by a base portion 7a and two leg portions 7b and 7c extending long from the base portion 7a. And the hole 7d for inserting said axis | shaft 1i is formed in the base 7a. Further, the two leg portions 7b and 7c have one leg portion 7c inserted into the hollow shaft portion 5c-1 so that the tips of the two leg portions 7c are opposed to the peripheral surface of the permanent magnet 4a. Yes.

  The stator frame 5 and the yoke 7 are attached to the main plate 1 as follows. First, the leg portion 7c of the yoke 7 is inserted into the hollow shaft portion 5c-1, and on the other hand, the hole 5a of the stator frame 5 is fitted to the mounting shaft 1h of the base plate 1 having a cylindrical shape before assembly. On the other hand, the hole 7d of the yoke 7 and the hole 5b of the stator frame 5 are fitted to the mounting shaft 1i of the base plate 1 having a cylindrical shape before assembly. In this state, the yoke 7 is restricted from rotating on the mounting shaft 1 i by a restriction portion such as a wall in the recess formed in the ground plane 1. After that, the tips of the mounting shafts 1h, 1i are melted and deformed into a bowl shape, whereby the mounting state shown in FIGS. 1 and 2 is obtained.

By the way, in the case of a present Example, since the notch part 5c-4 is provided in the flange part 5c-3 as mentioned above, the yoke 7 inserts the leg part 7c in the hollow shaft part 5c-1. In this state, a part of the base part 7a enters the notch part 5c-4, and a part of the end surface of the yoke 7 in the hollow shaft part 5c-1 on the base part 7a side is a part of the base part 7a of the fitted yoke 7. The hollow shaft portion 5c-1 is in contact with a surface of the hollow shaft portion 5c-1 opposite to the end surface of the yoke 7 on the base portion 7a side, and the notch portion 5c-4 is a hollow shaft portion 5c- in a part of the base portion 7a of the fitted yoke 7. 4 is in contact with the coil 6 while being in contact with the side surface of the yoke 7 facing the end surface on the base 7a side . Therefore, in order to be able to compare with the configuration of the present embodiment, the shape and dimensions of the members other than the stator frame 5 and the coil 6 are exactly the same as those in FIG. FIG. 5 shows a case where the shutter device is configured without providing the notch 5c-4 as in the prior art. As can be seen by comparing FIG. 1 and FIG. 5, in the case of the present embodiment shown in FIG. 1, the length of the hollow shaft portion 5c-1 is obviously longer and the number of turns of the coil 6 is larger. It is increasing. Therefore, in the case of the present embodiment, it can be said that the driving force can be increased as compared with the conventional configuration. In other words, the dimension of the yoke 7 in the length direction is set after securing a predetermined driving force. It can be said that this is a configuration that can be shortened.

  In the above-described configuration of the present embodiment, the bobbin portion 5c is provided in the stator frame 5. However, as described in Patent Document 2, the stator frame 5 is a plate-like member, and the bobbin portion You may make it comprise 5c as an independent bobbin member. In this embodiment, only one yoke 7 is provided. However, as described in Patent Document 2, it may be configured by two overlapping yokes. Absent.

  Next, the operation of this embodiment will be described. FIG. 1 shows a photographing standby state, and the opening 1a is fully opened. At this time, the coil 6 is not energized. However, as is well known, at this time, the rotor 4 is attached so as to rotate in the clockwise direction by the magnetic attractive force acting by the opposing arrangement relationship between the magnetic pole of the permanent magnet 4a and the two magnetic pole portions of the yoke 7. The shutter blade 3 is rotated counterclockwise by the drive pin 4c, but this state is maintained because the shutter blade 3 is in contact with the stopper shaft 1d. Therefore, in this state, the photographer can observe the subject image via a liquid crystal display device or the like.

  When the release button is pressed during shooting, exposure for shooting is started by releasing the charge accumulated in the solid-state imaging device until then. When a predetermined time elapses, a forward current is supplied to the coil 6 by a signal from the exposure time control circuit. Therefore, the rotor 4 rotates counterclockwise, and the shutter blade 3 is rotated clockwise by the drive pin 4c. Thereby, the shutter blade 3 performs a closing operation, and immediately stops the contact with the stopper shaft 1e immediately after the opening 1a is completely closed.

  In this way, when the opening 1a is in the closed state, the imaging information is transferred to the image storage device, and when the transfer ends, a current in the reverse direction is supplied to the coil 6 this time. Therefore, the rotor 4 is rotated clockwise, and the shutter blade 3 is rotated counterclockwise by the drive pin 4c. As a result, the shutter blade 3 opens the opening 1a, and stops immediately after being fully opened, contacting the stopper shaft 1d. And the state which interrupted the electricity supply with respect to the coil 6 is the imaging | photography standby state shown by FIG.

  The present embodiment is configured as a shutter device in which a single shutter blade is reciprocally rotated. However, as is well known, the present invention is disclosed in Patent Documents 1 and 2. It can also be configured as a shutter device in which two shutter blades are simultaneously reciprocated in opposite directions. Further, the shutter device configured as described above and the shutter device according to the present embodiment can be employed as a lens barrier device with almost the same configuration. In addition, the present invention can also be used as a diaphragm device by forming a circular opening smaller than the opening 1a in the shutter blade 3 of the present embodiment, and the opening formed in the shutter blade 3 It is also possible to provide a filter device by attaching an ND filter plate. Further, two or more of such a shutter device, a diaphragm device, and a filter device may be configured as one unit. In such a configuration, an electromagnetic wave as in this embodiment is formed on a common ground plane. Two or more actuators are provided. These can also be said in the case of Example 2 below.

  Next, Example 2 will be described with reference to FIG. The present embodiment is different only in the shape of the flange portion 5c-3 of the stator frame 5 described in the first embodiment. For this reason, in the description of the first embodiment, everything except for the description related to the shape of the flange portion 5c-3 is also applied to the present embodiment. Therefore, the description thereof is omitted to avoid duplication. FIG. 4 shows the stator frame 5 of the present embodiment in the same manner as in FIG. 3. The substantially same parts as in the case of the stator frame 5 shown in FIG. Signed.

The stator frame 5 of the present embodiment is made of synthetic resin, and, like the stator frame 5 of the first embodiment, mounting shafts 1h erected on the ground plate 1 at positions near both ends in the length direction thereof. Holes 5a and 5b for inserting 1i are provided, and a bobbin portion 5c is formed between them. The bobbin portion 5c includes a hollow shaft portion 5c-1 and two flange portions 5c-2 and 5c-3 formed at both ends thereof. 6 is wound. However, the flange portion 5c-3 of the present embodiment is not provided with the notch portion 5c-4 in the first embodiment. Instead, the flange portion 5c has a bottom surface and a side surface at the same location. than other parts of -3 countersunk portion 5c-5 so as to be recessed in the thin and direction of the flange portion 5c-2 of the wall thickness is formed.

Since the stator frame 5 of the present embodiment has such a shape, when the leg portion 7c of the yoke 7 is inserted into the hollow shaft portion 5c-1 of the bobbin portion 5c, the base portion 7a of the yoke 7 partially viewed Mari write fitted into counterbore portion 5c-5, the bottom surface of the counterbore portion 5c-5 is, in the portion of the base 7a of the yoke 7 fitted, facing the bottom surface of the counterbore portion 5c-5 surface And the side face of the counterbore part 5c-5 comes into contact with the side face of the surface facing the bottom face of the counterbore part 5c-5 in a part of the base part 7a of the fitted yoke 7 . Therefore, although not as much as in the first embodiment, the length of the hollow shaft portion 5c-1 can be increased and the number of turns of the coil 6 can be increased as compared with the case of the conventional configuration shown in FIG. Is possible.

  In addition, although the electromagnetic actuator in each said Example is comprised as what was provided with only one bobbin which wound the coil, the electromagnetic actuator of this invention is not limited to such a structure, Patent Literature 3 includes a configuration in which the rotor permanent magnet has four poles and includes two yokes fitted with bobbins. And when using the electromagnetic actuator comprised in that way for the blade drive device for cameras, it is not limited to the diaphragm device of composition as described in patent documents 3, but the rotor itself is known as well-known. The shutter device and the diaphragm device having various configurations described in connection with the description of the first embodiment by providing the drive pin described in the first embodiment at an eccentric position of the rotating member rotated by the rotor. Therefore, it can be used as a drive source for the filter device.

FIG. 3 is a plan view of the first embodiment when the shutter device is viewed from the subject side. It is sectional drawing which showed the overlapping relationship of the member shown by FIG. 1 clearly. It is the perspective view which showed the shape of the stator frame of Example 1 clearly. It is the perspective view which showed the shape of the stator frame of Example 2 clearly. It is a top view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground plate 1a, 2a Opening part 1b, 2b, 3a Long hole 1c Blade shaft 1d, 1e Stopper shaft 1f, 1h, 1i Mounting shaft 1g Rotor shaft 2 Cover plate 5a, 5b, 7d Hole 3 Shutter blade 4 Rotor 4a Permanent Magnet 4b Arm 4c Drive pin 5 Stator frame 5c Bobbin part 5c-1 Hollow shaft part 5c-2, 5c-3 Flange part 5c-4 Notch part 5c-5 Counterbore part 6 Coil 7 Yoke 7a Base part 7b, 7c Leg part

Claims (5)

A rotor having a permanent magnet magnetized in the radial direction, and a base portion and two leg portions extending long from the base portion are substantially U-shaped, and the tip ends of the two leg portions are used as magnetic pole portions. one leg of the at least one yoke and a hollow shaft portion and the hollow shaft portion and the yoke closed and the hollow shaft portion and two flange portions formed on both ends of which are opposed to the peripheral surface of the rotor At least one bobbin fitted to the part, and a coil wound around the outer periphery of the hollow shaft part between the two flange parts of the bobbin,
The flange portion of the person who becomes the base side of the yoke when fitted to the hollow shaft portion on one of the legs of the yoke, the bottom surface becomes a bottom surface and side surface becomes the base side of the yoke square the flange portion of the person who becomes the base portion side of the thin and the yoke wall thickness than other portions of the flange portion be formed so as to be recessed in the direction of the flange portion on the opposite side of the hollow shaft portion It has a counterbore portion partially writing fits the base of the yoke when fitted into one leg of the yoke,
When the hollow shaft portion is fitted to one leg portion of the yoke, the bottom surface of the counterbore portion is in contact with the bottom surface of the counterbore portion at a part of the base portion of the fitted yoke. with contact on opposite sides, the side of the seat counterbore is, that you contact the side surface of the surface facing the bottom surface of the seat counterbore in some of the base portion of the fitted the said yoke Features an electromagnetic actuator. In the bobbin , when the hollow shaft portion is fitted to one leg portion of the yoke, the flange portion on the side of the base portion of the yoke has a spot where the counterbore portion is formed, and the counterbore portion. Instead, the notch is formed so that the base can contact the coil ,
When the hollow shaft portion is fitted to one leg portion of the yoke, a part of the end surface on the base side of the yoke in the hollow shaft portion is a part of the base portion of the fitted yoke. The abutting surface of the hollow shaft portion facing the end surface of the yoke on the base side, and the cutout portion of the yoke in the hollow shaft portion at a part of the base portion of the fitted yoke. electromagnetic actuator according to claim 1, characterized that you contact the side surface of the surface facing the end surface of the base portion side.   The electromagnetic according to claim 1 or 2, wherein the rotor is disposed between two plate-like members and is rotatably attached to a shaft provided on one of them. Actuator.   The electromagnetic actuator according to claim 3, wherein the bobbin is integrally formed with one of the plate-like members using a synthetic resin.   A base plate having an opening for exposure; at least one blade attached to the base plate so as to reciprocate in order to advance and retreat to the exposure opening; and a drive source for reciprocating the blade. The drive source is the electromagnetic actuator according to any one of claims 1 to 4, wherein the blade driving device for a camera is characterized.

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