JP2003075885A - Light quantity adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a magnetic induction member needs to be composed of two components to incorporate a coil frame in the magnetic induction member and magnetic circuit performance is not sufficient as to a light quantity adjusting device which use as a driving source an external magnetism type electromagnetic actuator having a nearly U-shaped magnetic induction member having two magnetic poles and a coil frame wound with a coil. SOLUTION: The magnetic induction member constituting a magnetic circuit is formed of an integrated component and then the magnetic circuit is made ideal to improve efficiency and even when a coil is wound around one side part connecting opposite side parts of the magnetic induction member in a nearly U shape, a recessed groove part is formed in the core part of the coil frame which is wound with the coil to fix the one connecting side part to the recessed groove part in an insulated state, thereby enabling coil winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount adjusting device used in a camera, a video camera or the like.

[0002]

2. Description of the Related Art Conventionally, a so-called outer magnet type electromagnetic actuator, which is constituted by a magnet rotor having a rotating shaft and a pair of magnetizing members opposed to each other with an air gap formed in the magnet rotor, is driven. As a light amount adjusting device used for a camera, a video camera or the like as a light source, there is one as proposed in Japanese Patent Laid-Open No. 11-95280.

[0003]

In the light quantity adjusting device proposed in the above publication, the light quantity adjusting blades arranged in the optical axis opening are driven by an electromagnetic actuator composed of a magnet rotor, an attracting member and a coil. is there. The magnetic circuit of the electromagnetic actuator section includes a coil that generates a magnetic field by passing an electric current, two magnetizing members (stator yokes in the above publication) that are excited by the magnetic field, and an air gap between the two magnetizing members. And a magnet rotor arranged to form The two magnetizing members are arranged so that their base ends contact each other at the center of the coil.

According to the proposal of the above publication, by providing an urging portion for urging the abutting portion into a pressure contact state, it is possible to prevent the joint displacement of the joint portion after assembly and to suppress the deterioration of the magnetic characteristics to the minimum. I am trying. However, there is a limit to how flat the contact surface can be, and only part of the uneven portion is in contact. It goes without saying, however, that it is even better if the magnetizing member is formed in a substantially U-shape in which the contact surfaces are joined to form an integral part.

However, at this time, the following problems occur. When a magnet is provided with magnetic poles on its opposite sides of the magnet-guiding member having a substantially U-shape, and the coil is wound around the remaining one side connecting the opposite sides, the magnet-guiding member is opposed. The bent portion with the sides interferes, and it becomes impossible to insert the magnetizing member into the tubular hole of the coil frame that electrically insulates the coil and the magnetizing member from each other.

Therefore, in the present invention, the efficiency is improved by forming the magnetic attraction member forming the magnetic circuit as an ideal magnetic circuit as an integral part, and the opposing side portions of the magnetic attraction member having a substantially U-shape are formed. An object of the present invention is to provide a light quantity adjusting device that can incorporate a coil frame that electrically insulates a coil and an attracting member even when the coil is wound around the remaining one side to be connected.

[0007]

A substrate having an optical axis opening, a light quantity adjusting blade arranged in the optical axis opening, a magnet rotor connected to the light quantity adjusting blade and having a rotation axis at its center, and a magnet rotor. In a light quantity adjusting device including an attracting member having a pair of magnetic poles that are arranged to face each other to form an air gap, a coil that excites the attracting member, and a coil frame that winds the coil,
A concave groove is formed in the core of the coil frame around which the coil is wound, and the magnetizing member has a substantially U-shape and has magnetic poles on opposite sides, and the opposite sides are connected to each other. One side is a light amount adjusting device which is fixed to the groove while being insulated from the coil.

Further, the opening of the recessed groove portion of the coil frame is narrowed, the magnetism-inducing member is fitted by elastic deformation of the opening portion of the recessed groove portion, and is installed with the coil with an insulating gap and temporarily fixed. The light amount adjusting device is provided with a fixing unit and a main fixing unit that is fixed after the coil is wound by the magnetizing member being sandwiched between the bottom surface of the groove portion of the coil frame and the substrate.

Further, at least two of the light quantity adjusting blades adjust the opening area by moving in parallel in mutually opposite directions, and the coil and the magnet rotor are in the same direction as the moving direction of the diaphragm blades. It is a light quantity adjusting device arranged continuously.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a light quantity adjusting device used in a camera, a video camera or the like according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of this. In this figure, the substrate 1 has an optical axis opening 5, and a guide pin 1a for regulating and guiding the movement direction of the light amount adjusting blade on a surface supporting the light amount adjusting blade, and the moving direction is regulated. L for holding on the surface to guide and support
A holding guide pin 1b having a shape is provided.

The light quantity adjusting blades 6 and 7 are formed of a thin piece of black polyester or the like, and have a function of blocking the optical axis opening by moving.

The light amount adjusting blade 6 is formed with slits 6a and 6b, and is inserted into the guide pin 1a and the holding guide pin 1b provided on the substrate 1, respectively, and the movement direction is regulated and guided on the substrate 1 so as to be slidable. Supported by.

Further, the light quantity adjusting blade 7 is provided with slits 7a and 7b and is provided with a guide pin 1a provided on the substrate 1.
Is inserted into the holding guide pin 1b and the light amount adjusting blade 6 is sandwiched between the substrate 1 and the holding guide pin 1b, and the movement direction is regulated and guided on the substrate 1 and supported slidably.

At this time, the light amount adjusting blade 7 has three slits 7b held by the holding guide pin 1b of the substrate, and the slit 7c is fitted and held by the connecting pin 4c of the arm 4 which will be described later, so that it is held at three points. , It will be held without falling off from the substrate. Further, the light amount adjusting blade 6 is supported by the slits 6b and 6c only at two points in the same manner as above, but since it is sandwiched between the light amount adjusting blade 7 and the substrate 1, it is also held without dropping off from the substrate. It

The magnet rotor 3 is, as shown in FIG.
The magnet 9 is composed of a cylindrical magnet 9 which is magnetized to have two poles in the radial direction, and an arm 4 which is fixed by penetrating the center of the cylinder of the magnet 9. As shown in FIG. Shafts 4a and 4b are formed on both ends of the connecting pin 4c
・ 4d is formed.

In this magnet rotor 3, after the shaft portion 4a is inserted into the bearing portion 2a formed on the substrate, the shaft portion 4b is inserted from the slit-shaped opening 2c by utilizing the elastic deformation of the bearing portion 2b to obtain the bearing hole diameter. Try to fit in 2e. Further, after that, the slits 6c and 7c provided in the light amount adjusting blades 6 and 7 are expanded by elastic deformation of the light amount adjusting blades, and are fitted into the connecting pins 4d and 4c, respectively, and the magnet rotor and the light amount adjusting blades are connected. It In this state, each shaft and bearing have a clearance, and the magnet rotor can reciprocate.

FIG. 4 is an exploded perspective view of the excitation unit 10 shown in FIG. The magnetic attraction member 11, which is a ferromagnetic material, is formed in a substantially U-shape and has magnetic poles 11b and 11c facing each other, and a connecting portion 11a is fitted into a concave groove portion 12a of the coil frame 12. At this time, a hooking claw 12b is formed on the opening side of the recessed groove 12a so as to narrow the opening width, and when the magnetism-inducing member 11 is inserted, the opening is enlarged due to elastic deformation and the coil is inserted. The space of the frame 12 around which the coil is wound is hooked with a gap.

FIG. 5 is a sectional perspective view of the excitation unit 10. The magnetism attracting member 11 has a substantially U-shape, and the remaining one side 11a connecting the opposite sides opposite to each other is the coil frame 12.
It is fixed by a hook claw 12b to a groove 12a provided in the core wound with the coil.

This fixing is performed when the coil 15 is wound.
The temporarily fixed state may be such that there is no inconvenience when the coil is wound such that the magnetism attracting member 11 comes off from the coil frame 12. With such a temporary fixing state, the hooking claw 12b can be set so that the magnetism attracting member 11 can be easily fitted into the coil frame 12, and the assembling work becomes easy. As will be described later, the magnetizing member 11 is permanently fixed in a later step.

Further, as shown in the drawing, a gap is provided for electrical insulation between the coil 15 and the coil 15 by the latching claw 12b between the coil 15 and the magnetizing member 11a which is also an electric conductor. . As a result, it is possible to prevent problems such as a short circuit due to contact between the coil 15 and the magnetizing member 11 which is also an electric conductor. The electrical insulation may be achieved by incorporating other components without providing a void for the electrical insulation.

Then, the terminal pin 13 is inserted and fixed in the hole formed in the coil frame 12, and then the wire end of the coil is wound around the terminal pin 13 and passed through the small hole of the copper wire printing plate 14 to obtain the copper wire printing plate. And soldered together.

Further, the positioning hole 11d of the magnetic attraction member 11 is inserted into the position pin 1c provided on the substrate 1, the magnetic attraction member 11 is positioned on the substrate 1, and the coil frame 12 is provided on the substrate 1. When it is fitted and fixed in the fixed claw 1d, it is sandwiched between the bottom of the concave groove portion of the coil frame 12 and the substrate 1 and is permanently fixed with the strength required for the device.

According to this main fixing method, the coil frame 12 and the magnetic attraction member 11 can be fixed to the substrate 1 at the same time, which simplifies the assembly process. Of course, the coil frame 12 and the magnetizing member 11 may be separately fixed to the substrate 1.

The light quantity adjusting device configured as described above is shown in FIG.
As shown in FIG. 5, at least two of the light amount adjusting blades are moved in parallel in opposite directions to adjust the opening area, and the coil and the magnet rotor are continuous in the same direction as the moving direction of the diaphragm blades. By arranging in such a manner, the overall shape of the light quantity adjusting device becomes a longitudinal shape extending in one direction from the optical axis. With this shape, space in the other direction of the optical axis can be used, and in the lens barrel to which this light amount adjusting device is attached, for example, the support shaft of the movable lens, the zoom lens drive motor, the focus lens drive motor, etc. can be used in the other direction. It is possible to arrange the lens barrel near the optical axis and it is possible to reduce the size of the entire lens barrel.

The light quantity adjusting device constructed as described above is as shown in FIG. The substrate 1 is provided with the light amount adjusting blades 6 and 7, the magnet rotor 3 and the excitation unit 10, and the coil 15
The magnetizing member 11 is magnetized by the current flowing through the magnetic pole 11b.
And 11c generate magnetic poles. Due to the generation of the magnetic poles, the magnet rotor 3 magnetized into two poles in the radial direction rotates, and the connecting pins 4c and 4d formed on the magnet rotor 3 are rotated.
The light amount adjusting blades 6 and 7 are moved by (not shown), and each light amount adjusting blade is opened and closed to adjust the amount of light passing through the optical axis opening 5.

As described above, in the present invention, efficiency is improved and performance of the light quantity adjusting device is improved by forming the magnetic attraction member forming the magnetic circuit as an integrated component into an ideal magnetic circuit.
Further, even when the coil is wound around the remaining one side connecting the opposite sides of the U-shaped magnetizing member, a coil frame for electrically insulating the coil and the magnetizing member can be incorporated, and The magnetic member is incorporated into the coil frame, temporarily fixed, and then wound around the coil to be permanently fixed to the substrate to facilitate the assembly.

[Brief description of drawings]

FIG. 1 is a perspective view of a light amount adjusting device.

FIG. 2 is an exploded perspective view

FIG. 3 is an exploded perspective view of a magnet rotor

FIG. 4 is an exploded perspective view of an excitation unit.

FIG. 5 is a sectional perspective view of an excitation unit.

[Explanation of symbols]

1 substrate 2a Bearing part 2b Bearing part 2c slit-shaped opening 3 magnet rotor 4 arms 6 Light intensity adjustment blades 7 Light intensity adjustment blade 9 magnets 10 Excitation unit 11 Magnetic attraction member 11b magnetic pole 11c magnetic pole 12 coil frame

Claims (5)

[Claims] 1. A substrate having an optical axis opening, a light quantity adjusting blade arranged in the optical axis opening, a magnet rotor connected to the light quantity adjusting blade and having a rotation axis at its center, and an air gap in each of the magnet rotors. In a light quantity adjusting device including an attracting member having a pair of magnetic poles that are formed to face each other, a coil that excites the attracting member, and a coil frame that winds the coil, A concave groove is formed in the core wound with the coil, and the magnetizing member has a substantially U shape and has magnetic poles on opposite sides, and one side connecting the opposite sides is A light amount adjusting device, which is fixed to the concave groove portion in an insulating state from the coil. 2. The concave groove portion of the coil frame has a narrow opening, and the magnetizing member is fitted by elastic deformation of the opening portion of the concave groove portion, and is mounted with an insulating gap from the coil. The light amount adjusting device according to claim 1. 3. The magnetizing member is temporarily fixed by being fitted into a concave groove portion of the coil frame, and the magnetizing member is wound around the coil frame in a temporarily fixed state. 2. The light amount adjusting device according to claim 1, further comprising: a main fixing unit that permanently fixes the magnetizing member to the substrate after winding the coil. 4. The magnetizing member is temporarily fixed by being fitted into a concave groove portion of the coil frame, and winding means for winding the magnetizing member around the coil frame in a temporarily fixed state. 2. The light amount adjusting device according to claim 1, further comprising: a main fixing unit that holds the magnetizing member between the bottom surface of the groove portion of the coil frame and the substrate after the coil is wound and is finally fixed. . 5. The light amount adjusting blade adjusts the opening area by at least two parallel moving in opposite directions, and the coil and the magnet rotor are in the same direction as the moving direction of the diaphragm blade. The light quantity adjusting device according to claim 1, wherein the light quantity adjusting devices are arranged in series.