JP4140781B2 - Light amount adjusting device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a light amount adjusting device that is incorporated in an imaging optical path of a camera or the like and adjusts a photographing light amount such as a shutter or a diaphragm device. The blade member is disposed in an optical axis opening, and the blade member is set according to an input signal. The present invention relates to a light amount adjusting device including a driving unit that drives the light source.

  Conventionally, this kind of camera shutter, diaphragm device and other light amount adjusting devices adjust the optical axis opening by attaching a pair of light amount adjusting blades 3 and 4 to the base plate 1 so as to be openable and closable as shown in FIG. Like to do. The blades 3 and 4 are engaged with a drive arm 7 attached to a rotor 5 of a drive motor to control opening and closing. The drive motor includes a pair of coil frames 8a and 8b each having a coil wound around the outer periphery, a rotor 5 that rotatably supports the rotating shaft 6 therein, and a yoke 9 that covers the outer periphery of the coil frame. Yes.

  10 is a cap that covers the bottom of the coil frame, and 2 is a cover member (pressing plate) that covers the blades on the base plate. Then, after the ground plate for allowing the blades to open and close to the optical axis opening and the drive motor are manufactured separately, the drive motor is attached to the ground plate. For this attachment, as disclosed in Patent Documents 1 and 2, for example, a stem-like attachment member is integrally formed on a base plate that supports a blade, and a coil frame, a rotor, and a yoke are incorporated in the attachment member. Yes. In order to attach the coil frame to one or two stems integrally formed on the base plate in this way, the coil frame is divided into two parts on the left and right sides with the rotation shaft of the rotor interposed therebetween, and the left and right coil frames are combined with the stems sandwiched between them. By doing so, the drive motor is attached to the main plate.

  Therefore, it is difficult to integrally form the bearing portion that supports the rotation axis of the magnet rotor in the coil frame divided into two on the left and right sides, and any patent document is provided with a cap member separate from the coil frame. Since the bearing portion is formed on the cap member, the number of parts is large and the assembly is complicated.

  Reference 3 proposes an actuator in which a bearing is formed on a coil frame that is divided into two parts in the upper and lower directions to support the magnet rotor as a bearing. However, in this publication, the actuator and the ground plane are manufactured separately. An actuator in which an actuator is attached to the ground plane is disclosed. The publication does not disclose a specific structure for attaching the actuator to the base plate and driving and connecting the rotor to the blade member. As described above, the coil frame and the ground plane are individually manufactured in any of the patent documents.

On the other hand, in the patent application of Patent Document 4 preceding the present application, one in which one of the upper and lower coil frames is integrally formed with the ground plate is disclosed, but the support of the blade member and the drive connection of the rotor are shown in FIG. The structure shown is adopted. That is, one of the coil frames 1 and 2 divided into the upper and lower sides and the ground plate are integrally formed with the other of the coil frames and the support plate, and the blade 6 is rotatably supported on the rotating shaft 3 of the rotor 5 to support the ground plate and the support plate. The structure which protects so that a blade | wing may be pinched | interposed with is proposed. In such a structure, since the edge 6a of the blade 6 enters the inside of the yoke 9, if the blade is formed of a metal such as a soft magnetic material, the magnetic circuit in the yoke may be affected. The coil 8 is wound after the 6 is attached to the rotor shaft 3.
Japanese Patent Laid-Open No. 07-281252 (FIG. 1) Japanese Utility Model Publication No. 05-064835 (FIG. 1) Japanese Utility Model Publication No. 02-078934 (Fig. 2 on page 6) Japanese Patent Application No. 08-202422 (Japanese Patent Laid-Open No. 10-48697)

  As described above, the substrate (ground plate) that supports the conventional light quantity adjusting blade and the rotor, coil frame, yoke, etc. that constitute the drive motor are individually manufactured and assembled to the substrate after the drive motor is assembled. The position accuracy cannot be obtained unless individual parts are made large and manufactured. Therefore, the apparatus has a drawback that it is large in size and expensive in assembly. At the same time, as described in Patent Documents 1 and 2 above, when the drive motor is attached to the ground plate, a method of fixing the stem-shaped mounting member integrally formed on the ground plate so as to be held by a coil frame divided into left and right is a magnet rotor. There is a need for a member different from the coil frame for supporting the bearing, and the number of parts increases, and there is a problem that the accuracy of each part affects the rotation of the magnet rotor smoothly.

  Further, in the method of the above-mentioned Patent Document 4, since the blade member is fitted and supported on the rotating shaft of the magnet rotor, the plurality of blade members cannot be rotated or manually supported, and at the same time a metal such as a soft magnetic material. If the blades are made of material, the magnetic circuit that rotates the rotor is affected, and there is a problem that stable driving rotation cannot be obtained. In addition, since the blade member is incorporated in the coil frame and fitted and supported on the rotating shaft of the magnet rotor, the method of winding the coil has to be taken, so that the assembly is complicated and costly.

  Therefore, the present invention can be manufactured at a low cost by forming the coil frame constituting the driving device, the projection for restricting the movement of the blade member, and the bearing portion of the magnet rotor by integral molding, with a small number of parts and a small number of assembly steps. An object of the present invention is to provide a light amount adjusting device that can be used and that a blade member does not affect the magnetic circuit that rotates the rotor at the same time and can always obtain a stable driving rotation. Further, in the present invention, after the coil is wound around the coil frame, the blade member is engaged and incorporated into the protrusion for regulating the movement, and in this state, the blade member and the magnet rotor can be driven and connected. It is an object of the present invention to provide a manufacturing method that is easy to handle.

In order to solve the above problems, the present invention employs the following configuration.
In the first aspect of the present invention, the light amount adjusting device includes a light amount adjusting blade that adjusts the light amount, a drive unit that incorporates a magnet rotor in a coil frame in which a coil is wound around the outer periphery, It is comprised with the drive arm engaged with a light quantity adjustment blade | wing. And the said coil frame is comprised with the two coil frames divided | segmented up and down in the axial direction of the said magnet rotor. At this time, on one side of the coil frame, a bearing for supporting the rotating shaft of the rotor, a concave groove for winding the coil, and a protrusion that engages with the light quantity adjusting blade to guide the opening and closing of the blade, for example, synthetic resin It is integrally formed by molding such as. Similarly, the other coil frame is formed with a bearing that supports the rotating shaft of the magnet rotor, a concave groove that winds the coil, and a yoke fitting portion of a yoke that is formed on the outer periphery and covers the magnet rotor. .

Then, the two coil frames are combined in a state in which the magnet rotor is built in, and a coil is wound around the groove formed in each, and the drive arm is protruded to the outside of the upper coil frame. It fits into the engagement hole of the light quantity adjusting blade.

  That is, as in the embodiments described later, a bearing portion is located at the center of the yoke, and a coil is positioned around the yoke, and a projection that regulates the movement of the light amount adjusting blade on the outside of the yoke and the light amount adjusting blade is driven by this The positional relationship is such that the engaging portion of the transmission arm to be transmitted is located. As a result, it is possible to reduce the number of parts and the processing and assembly man-hours.

  According to a second aspect of the present invention, the projection for guiding the opening and closing of the light amount adjusting blade is formed on a flat surface that supports the light amount adjusting blade, and the light amount adjusting blade supported by the protrusion is along the flat surface. The light quantity adjusting blade is restricted in movement by a protrusion, and a smooth opening / closing movement is enabled by the flat surface of the projecting portion of the protrusion.

  Further, the invention of claim 3 is the method of manufacturing the light quantity adjusting device of claim 1, wherein the coil frame is composed of two coil frames divided vertically in the axial direction of the magnet rotor. On the other hand, a bearing for supporting the rotating shaft of the rotor, a concave groove for winding the coil, and a projection for engaging with the light quantity adjusting blade to guide the opening and closing of the blade are formed by integral molding. The other of the coil frames forms a bearing that supports the rotating shaft of the magnet rotor, a concave groove that winds the coil, and a yoke fitting portion of a yoke that is provided on the outer periphery and covers the magnet rotor.

  And the engagement part which fits the engagement groove formed in the light quantity adjustment blade outside the yoke fitting part in the state where the two coil frames are united with the drive arm and the rotor is built in, After combining the two coil frames and incorporating the rotor, the coil is wound along the concave groove. Next, the fitting of the yoke to the yoke fitting portion, the engagement of the light amount adjustment blade to the protrusion, and the engagement portion formed on the drive arm to the engagement groove of the light amount adjustment blade I do. Thus, the same result as that of the invention of claim 1 can be obtained.

  In the present invention, a coil frame constituting a driving device is divided into upper and lower axial directions of a magnet rotor, a bearing portion for supporting the rotating shaft of the magnet rotor on the upper and lower coil frames, and a concave groove for winding the coil. Therefore, the magnet rotor can be supported smoothly without the need for special parts for forming the bearing portion. In addition, the bearing, the protrusion for restricting the movement of the blade member, and the groove for winding the coil are integrally formed on one side of the coil frame, and the bearing and the recess for winding the coil are wound on the other coil frame. Since the groove and the yoke fitting portion for fitting the yoke are formed, it is possible to provide an inexpensive apparatus with a small number of parts and a small number of assembly steps.

  In particular, a bearing portion that supports the rotor and a concave groove that winds the coil are arranged inside the yoke, and a protrusion that engages the blade member and an engaging portion of the drive arm are arranged outside the yoke, for example, Even if the blade member is made of a metal material such as a soft magnetic material, stable driving rotation can be obtained without affecting the magnetic circuit formed in the yoke. At the same time, in the manufacturing method, after the coil is wound around the coil frame, the blade member is fitted to the protrusion and assembled, and in this state, the engaging portion of the drive arm can be connected to the blade member. There are effects such as easy assembly and disassembly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a diaphragm device of a camera. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a bottom view of FIG. The aperture device 20 includes a drive motor 30 as drive means and a pair of aperture blades 40 and 41 as light quantity adjustment blades as shown in FIGS. 5A and 5B. The drive arm 32 fixed to the rotary shaft 31 of the drive motor 30 and the aperture blade are engaged. The diaphragm blades 40 and 41 are formed of a very thin special metal material or the like and supported by a support member such as a base plate. As shown in the perspective view of FIG. 6, the coil frame 50 of the drive motor 30 includes a first coil frame 51 and a second coil frame 60 that are divided by a plane orthogonal to the rotation shaft 31.

FIG. 4 shows a longitudinal sectional view of the first coil frame 51. The first coil frame 51 is formed by integrally molding a frame body portion 52 and a support portion 53 having a flat surface that supports the diaphragm blades 40 and 41. As shown in the longitudinal sectional view 2, the frame body 52 is provided with a concave groove (winding groove) 521 for winding a coil (not shown). On the other hand, guide protrusions are provided on the support portion 53 so as to be fitted and guided in the guide grooves 40a, 40b, 41a, 41b of the diaphragm blades 40, 41 . That is , the movement of the blades is restricted by the protrusions shown as reference numerals 531, 532, 533, and 534 in FIG. 1 and as reference numerals 721 and 722 in FIG. Thus, the flat surface 53, the guide protrusions (531, 532, 533, and 534 in FIG. 1 and 721 and 722 in FIG. 6), and the groove 521 are formed on the first coil frame 51 on the outer surface side . .

  Further, the guide protrusions 532 and 534 are fitted in the guide grooves 40b and 41b, respectively, and support not only the sliding guide in the side direction but also the facing direction of the flat surface 53 (the vertical direction in FIG. 4). . As shown in FIGS. 2 and 6, the second coil frame 60 is substantially cylindrical, and is formed with a hollow portion 601 that rotatably accommodates a rotor 33 that is a permanent magnet described later. A winding groove 602 corresponding to the winding groove 521 of the coil of the first coil frame 51 is formed on the outer surface side, and a bearing hole (bearing) of the rotating shaft 31 of the rotor 33 described later is formed on the inner surface side. 603 is provided. Note that the second coil frame 60 is coupled to the first coil frame 51 by screws 61.

  The rotor shaft 31 as a rotation shaft is integrated through the center of the rotor 33, and both ends of the shaft are provided with bearing holes (bearings) 522 formed on the inner surface side of the first coil frame 51, and the second coil. It is rotatably supported by a bearing hole (bearing) 603 formed on the inner surface side of the frame 60. Further, as shown in FIGS. 1 and 2 and the like, the rotor shaft 31 is fixedly provided with a driving arm 32 that engages with the aperture blades 40 and 41 and transmits a driving force. The drive arm 32 is provided with a pair of engaging portions 32 a and 32 b that are engaged with the engaging holes 40 d and 41 d of the diaphragm blades 40 and 41.

  In addition, after the engaging portions 32a and 32b are passed through the engaging holes 40d and 41d of the diaphragm blades 40 and 41, respectively, holding members 34a and 34b for suppressing the fluttering of the blades 40 and 41 in the direction perpendicular to the surface are provided. It can be attached. The diaphragm blades 40 and 41 are supported in two directions perpendicular to each other by the holding members 34 a and 34 b and the guide protrusions 532 and 534 among the guide protrusions of the first coil frame 51.

  Therefore, no special cover member is required. The outermost part of the drive motor 30 is a cylindrical yoke 35 formed by winding a thin steel plate and is fitted to a yoke fitting portion 604 formed on the outer periphery of the second coil frame 60. Yes. The yoke 35 is partially formed with a notch 35a for positioning the rotor 33 at a predetermined home position when the coil is not energized.

  Next, a manufacturing method will be described. First, the rotor shaft 31 and the drive arm 32 are combined, and then the drive arm 32 is fitted into the rotor 33 and fixed. At this time, the direction of the NS magnetic pole of the rotor 33 and the direction of the drive arm 32 are determined at a predetermined relationship position. This is for determining the position of the drive arm 32 at the time of non-energization in relation to the position of the notch 35a of the yoke 35 later.

  Thereafter, the end of the rotor shaft 31 on the drive arm 32 side is inserted into the support hole (bearing) 522 of the first coil frame 51, and the other end is inserted into the support hole (bearing) 603 of the second coil frame 60. Both the coil frames 51 and 60 are coupled by a plurality of screws 61. Next, a predetermined coil is wound around the coil winding grooves 521 and 602 of both the coil frames 51 and 60. Usually, the winding is divided into a set of a drive coil and a braking coil with a slight gap, but the illustration is omitted.

  Next, the yoke 35 is fitted along the outer periphery of the second coil frame 60 while paying attention to the direction of the notch 35a. Next, the guide groove 40 a of the diaphragm blade 40 is engaged with the guide protrusion 531 of the support portion 53, the guide groove 40 b is also engaged with the guide protrusion 532, and the guide groove 40 c is engaged with the guide protrusion 534. On the other hand, the engagement hole 40 d is engaged with the engagement portion 32 a of the drive arm 32. Then, the holding member 34a is coupled. Similarly, the diaphragm blade 41 is engaged with the support portion 53 of the first coil frame 51 and the engagement portion 32 b of the drive arm 32. In addition to the above, in the hollow portion 601 of the second coil frame 60, a Hall element or the like is incorporated as a detection sensor for the rotational position of the rotor 33, and a terminal that supports the end of the wound coil. A pin or the like may be provided.

  The diaphragm device 20 assembled in this way is incorporated in front of the photosensitive means of the camera, for example, the CCD via the lens, and a current corresponding to the luminance information of the subject is input to the drive coil, and the magnetic field formed by the drive coil. As a result, the rotor 33 rotates and the drive arm 32 swings to drive the aperture blades 40 and 41 to an appropriate opening position. Thus, the diaphragm blades 40 and 41 do not require a large base plate or diaphragm cover as in the prior art, and are extremely compact.

It is a top view of the diaphragm | throttle device for cameras using this invention. It is sectional drawing in FIG. It is a bottom view of the aperture device of a camera. It is a longitudinal cross-sectional view of the 1st coil frame of the coil frame in 1st Example. (A) is a plan view of one diaphragm blade, and (B) is a plan view of the other diaphragm blade. It is a perspective view of the coil frame of the apparatus of FIG. It is decomposition | disassembly explanatory drawing of the conventional aperture_diaphragm | restriction apparatus. It is explanatory drawing of the prior art different from FIG.

Explanation of symbols

20 Aperture device of camera (light quantity adjustment device)
30 Drive motor (drive means)
31 Rotor shaft (rotating shaft)
32 Drive arm (output arm)
33 Rotor 40 Aperture blade (light quantity adjustment blade)
41 Aperture blades (light intensity adjustment blades)
50 Coil frame (first embodiment)
51 1st coil frame 52 Frame part (coil frame part) (1st Example)
53 Supporting part (first embodiment)
60 Second coil frame 70 Coil frame (second embodiment)
71 Frame body (coil frame portion) (second embodiment)
72 Supporting part (second embodiment)

Claims (3)

A light amount adjusting blade that adjusts the light amount, a blade support member that supports the light amount adjusting blade so as to be openable and closable, a driving means that incorporates a magnet rotor in a coil frame in which a coil is wound around the outer periphery, and a magnet rotor that is provided integrally with the magnet rotor A light amount adjusting device comprising: a drive arm that engages with the light amount adjusting blade;
The blade supporting member is integrally formed with a projection for guiding the opening and closing of the light amount adjusting blade,
The coil frame is composed of an upper coil frame and a lower coil frame that are divided in the axial direction of the magnet rotor,
The upper coil frame is composed of a bearing that supports the rotating shaft of the rotor and a concave groove that winds the coil, and the concave groove is formed by integral molding with the blade support member,
The lower coil frame is configured with a bearing for supporting a rotary shaft of the magnet rotor, a groove for winding the coil, from a yoke fitting portion fitting the yoke covering the magnet rotor,
The upper coil frame and the lower coil frame are combined in a state in which the magnet rotor is built in, and the coil is wound around the concave grooves formed respectively.
A light amount adjusting device, wherein the drive arm protrudes to the outside of the upper coil frame and is fitted into an engagement hole of the light amount adjusting blade. The blade support member includes a flat surface that supports the light amount adjustment blade, and a protrusion that is formed on the flat surface and guides the opening and closing of the light amount adjustment blade.
The light amount adjusting device according to claim 1, wherein the light amount adjusting blade supported by the protrusion is opened and closed along the flat surface. A light amount adjusting blade that adjusts the light amount, a blade support member that supports the light amount adjusting blade so as to be openable and closable, a driving means that incorporates a magnet rotor in a coil frame in which a coil is wound around the outer periphery, and a magnet rotor that is provided integrally with the magnet rotor A drive arm that engages with the light quantity adjusting blade;
A method of manufacturing a light amount adjusting device comprising:
A protrusion for guiding the opening and closing of the light amount adjustment blade is integrally formed on the blade support member,
The coil frame is composed of an upper coil frame and a lower coil frame that are divided vertically in the axial direction of the magnet rotor,
The upper coil frame, Rutotomoni is composed of a bearing and grooves for winding the coils for supporting a rotary shaft of the rotor, the groove is formed by integral molding to the blade carrier member,
The lower coil frame includes a bearing that supports the rotating shaft of the magnet rotor, a concave groove that winds the coil, and a yoke fitting portion of a yoke that is provided on the outer periphery and covers the magnet rotor,
The upper coil frame and the lower coil frame are combined in a state where the magnet rotor is incorporated, and the coil is wound around the groove formed in each, and then the yoke is fitted into the yoke fitting portion. And
A method of manufacturing a light amount adjusting device, wherein the engaging portion of the drive arm that protrudes outside the upper coil frame is fitted into an engaging groove of the light amount adjusting blade supported by the blade supporting member.

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