JP2011085682A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device that facilitates the joining of the terminals of a driving coil, prevents damage to the terminals of the driving coil, and has a driving-coil connection form that prevents adverse effect on spring members and a holder. <P>SOLUTION: Fastening members 18A and 18B made of an insulating material are projectingly formed above and below the driving coil 15 on the outer circumferential side of the holder 14. The terminals 19A and 19B of the driving coil 15 are fastened to the fastening members 18A and 18B, and the insulating films of the fastened portion are removed. Thereafter, the fastened portions of the terminals 19A and 19B and the inner ring portions 17a or connecting pieces 17j of plate springs 17A and 17B are brought into contact with and fixed to each other using an adhesive. Thus, the driving coil 15 and the plate springs 17A and 17B are electrically connected without damaging the terminals 19A and 19B of the driving coil 15. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens driving device using a voice coil motor used in a camera or the like, and more particularly, to a configuration in which a terminal of a driving coil mounted on a movable lens holder is connected to a leaf spring.

In recent years, a camera mounted on a mobile phone or the like has increased in the number of pixels of an image sensor, and the quality of captured images has been improved. Along with this, the lens system to be mounted is also shifting from the conventional fixed focus camera module to the movable focus camera module. This is because a fixed-focus camera module causes defocusing and cannot cope with the resolution of the high pixel number image sensor.
As a lens system driving method in a movable focus camera module, a lens driving device using a voice coil motor is often used.

FIG. 10 is a diagram illustrating a configuration example of a lens driving device 50 using a conventional voice coil motor. The lens driving device 50 includes a yoke 51 having a U-shaped cross section made of a magnetic material such as soft iron, a cylindrical permanent magnet 52 attached to the inner wall side of the yoke 51, and a holder 54 that holds the lens 53 at a central position. The drive coil 55 mounted on the holder 54, the case 56 mounted with the yoke 51 on the inner peripheral side, and the upper and lower leaf springs 57 (57A, 57B) connecting the holder 54 and the case 56 are provided. (For example, refer to Patent Document 1).
As shown in FIG. 11, the leaf spring 57 includes an inner ring portion 57a fitted to the holder 54, an outer ring portion 57b attached to the case 56, and a flange portion 57c that connects the inner ring portion 57a and the outer ring portion 57b. And the flange portion 57c functions as a spring element.

The driving coil 55 of the lens driving device 50 is installed in a magnetic field distributed by the yoke 51 and the permanent magnet 52 and distributed radially around the coil. Accordingly, when the drive coil 55 is energized, the drive coil 55 generates a Lorentz force directed in the direction of the subject (vertical direction) as indicated by an arrow Z in FIG. The plate spring 57 can be moved to a position balanced with the restoring force of the leaf spring 57.
In other words, the position of the lens 53 can be controlled by controlling the amount of movement of the holder 54 by controlling the current value supplied to the drive coil 55.

Since the plate spring 57 is a plate-like conductor made of, for example, a metal or an alloy, in the lens driving device 50, the terminals 55k and 55l of the drive coil 55 are connected via the plate spring 57 which is a conductor. The drive coil 55 can be energized by connecting to a power supply line connected to a drive power supply (not shown).
Specifically, as shown in FIGS. 11 and 12, the terminal 55k of the winding start portion of the driving coil 55 attached to the holder 54 is pulled out, and the gap between the inner ring portion 57a and the flange portion 57c of the leaf spring 57A is pulled out. The inner space 57a or the flange portion 57c is soldered near the root 57d through the gap 57s. In FIG. 12, reference numeral 57P denotes a soldering portion (joint portion).
The winding end terminal 55l is also soldered to a leaf spring 57B (not shown) in the same manner as the winding start terminal 55k.

JP 2004-280031 A

However, the size of the gap between the inner ring portion 57a and the flange portion 57c of the leaf spring 57 is generally as narrow as 100 μm to 150 μm, and the winding constituting the driving coil 55 has a wire diameter of about 50 μm. Since it is extremely thin, it must be carefully passed through the gap 57s between the inner ring portion 57a and the flange portion 57c of the leaf spring 57 so as not to damage the terminals 55k and 55l of the drive coil 55. For this reason, it takes time to work, and sometimes the terminals 55k and 55l are damaged, and the insulating film of the drive coil 55 is peeled off.
Further, since the heat of the soldering iron is transmitted to the flange 57c of the plate spring 57 and the flange 57c is heated, the spring characteristics are deteriorated or the soldering portion 57P is close to the holder 54. The holder 54 was contacted and melted.
Furthermore, since the soldering of the leaf spring 57 and the terminals 55k and 55l of the driving coil 55 is a delicate operation by hand, it takes time to assemble the apparatus and is difficult to automate. For this reason, the soldering operation is not only an obstacle to cost reduction, but also has a problem that the quality of the joint portion varies depending on the ability of the operator.

  The present invention has been made in view of the conventional problems, and facilitates the joining operation of the terminal of the driving coil, does not damage the terminal of the driving coil, and has an adverse effect on the spring member and the holder. An object of the present invention is to provide a lens driving device having a connection form of a driving coil that does not occur.

As a result of intensive studies, the inventor does not directly solder the terminal of the driving coil to the leaf spring, but projects a binding member for tying the terminal of the driving coil to the holder. After the terminal of the driving coil is entangled with the member, the terminal of the driving coil entangled with the binding member and the holder side of the leaf spring are electrically connected by soldering, welding, or the like. The present inventors have found that the above problem can be solved and have reached the present invention.
That is, the present invention is a holder for holding a lens, a driving coil mounted on the outer peripheral side wall of the holder, and arranged on the outer peripheral side of the driving coil so as to face the driving coil with a gap. A permanent magnet, a case for holding the permanent magnet, and a leaf spring for connecting the holder and the case, wherein the holder protrudes from the holder. A binding member for binding the terminal of the driving coil is provided, and the terminal of the driving coil entangled with the binding member and the holder side of the leaf spring are electrically connected. It is characterized by being.
As a method of electrically connecting the terminal of the driving coil and the holder side of the leaf spring, in addition to soldering or welding, the terminal of the driving coil and the holder side of the leaf spring are in contact with each other. There are methods such as bonding with an adhesive or the like, or bonding the terminal of the driving coil and the holder side of the leaf spring with a conductive adhesive or the like.

Further, the present invention provides a solder layer in which the end of the driving coil entangled with the binding member and the holder side of the leaf spring are provided between the holder side of the leaf spring and the binding member. Alternatively, it is electrically connected through a conductor plating layer.
As a result, the terminal of the driving coil and the holder side of the leaf spring can be electrically connected without directly connecting the terminal of the driving coil to the holder side of the leaf spring. The adverse effect can be further reduced and workability can be improved.
Further, the present invention is characterized in that a terminal of a driving coil entangled with the binding member and a holder side of the leaf spring are electrically connected by welding.
As a result, the connection between the leaf spring and the terminal of the driving coil becomes robust, so that the life of the device can be extended.

In the invention of the present application, the binding member is a conductor.
Accordingly, the terminal of the driving coil and the holder side of the leaf spring can be electrically connected only by electrically connecting the binding member and the leaf spring holder side. Can be easily and reliably electrically connected.

  At this time, the binding member and the leaf spring holder side are electrically connected via a solder layer or a conductor plating layer provided between the leaf spring holder side and the binding member. If the binding member and the leaf spring holder are electrically connected by welding, the terminal of the driving coil and the leaf spring holder can be easily and reliably electrically connected. The joining operation can be performed more efficiently.

  The summary of the invention does not list all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

It is a figure which shows the structure of the lens drive device which concerns on Embodiment 1 of this invention. It is a figure which shows the state which connected the terminal of the drive coil, and the leaf | plate spring electrically. It is a figure which shows the example which soldered the terminal and the leaf | plate spring of the drive coil. It is a figure which shows the example which connected the terminal and leaf | plate spring of the drive coil electrically through the plating layer. It is a figure which shows the example of a connection with the terminal of the divided | segmented leaf | plate spring and the drive coil. It is a figure which shows an example of the lens holder provided with the binding member which consists of conductors. It is a figure which shows the example which soldered the binding member which consists of conductors, and the leaf | plate spring. It is a figure which shows the connection method of the binding member which consists of conductors, and a leaf | plate spring. It is a figure which shows the other example of the connection method of the binding member which consists of conductors, and a leaf | plate spring. It is sectional drawing which shows the structure of the conventional lens drive device. It is a figure which shows the connection method of the terminal of the conventional drive coil. It is a principal part enlarged view of FIG.

  Hereinafter, the present invention will be described in detail through embodiments. However, the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

Embodiment 1 FIG.
FIGS. 1A and 1B are diagrams showing a configuration of a lens driving device 10 according to Embodiment 1 of the present invention. FIG. 1A is a sectional view of the entire device, and FIG. 1B is a driving coil. It is a principal part disassembled perspective view which shows the connection method of the terminal and the holder side of a leaf | plate spring.
The lens driving device 10 includes a yoke 11 made of a magnetic material such as soft iron, a permanent magnet 12 attached to the inner wall side of the yoke 11, a lens 13 in which an objective lens and an eyepiece lens are combined, and the lens 13 at a central position. A lens holder (hereinafter referred to as a holder) 14, a driving coil 15 mounted on the outer surface of the holder 14, a case 16 for mounting the yoke 11 on the inner periphery thereof, and the case 16 and the holder 14. And upper and lower leaf springs 17 (17A, 17B). In addition, the z direction of a figure was made into the up-down direction of the lens drive device 10, and xy plane was made into the horizontal surface.
The case 16, the yoke 11, and the permanent magnet 12 are members on the fixed side of the lens driving device 10 of the present invention, and the lens 13, the holder 14, and the driving coil 15 are members on the movable side. The upper and lower leaf springs 17 (17A, 17B) are connecting members that connect the fixed side and the movable side of the lens driving device 10.

The yoke 11 is a cylindrical part having an L-shaped cross section made of a magnetic material such as soft iron, and is disposed around the holder 14 at a predetermined interval.
The permanent magnet 12 is a cylindrical member attached to the inner wall of the yoke 11 and applies a magnetic field that is distributed radially around the drive coil 15 together with the yoke 11.
The holder 14 is a cylindrical part, and holds a lens 13 in which an objective lens and an eyepiece are combined at a central position. On the outer peripheral side surface of the holder 14 and on the upper side and the lower side of the driving coil 15, binding members 18 (18 </ b> A, 18 </ b> B) that project in the direction of the permanent magnet 12 are provided. In this example, the binding member 18 is made of an insulating material such as a resin, like the material constituting the holder 14.
The binding member 18 may be formed integrally with the holder 14 or may be attached to the holder 14 by bonding or fitting after the holder 14 is formed.
The driving coil 15 is mounted on the outer peripheral side wall of the holder 14. Terminals 19 (19A, 19B) of the driving coil 15 are electrically connected to the upper and lower leaf springs 17 (17A, 17B), respectively. In this example, the terminal 19A on the winding start side is connected to the upper leaf spring 17A, and the terminal 19B on the winding end side is connected to the lower leaf spring 17B.
The case 16 includes a base portion 16a and a yoke support member 16b protruding upward from the peripheral edge portion of the base portion 16a. The base portion 16a is a plate-like member having a rectangular shape in plan view, and supports the lower side of the holder 14 in a stationary state, and the yoke support member 16b supports the yoke 11 and the permanent magnet 12 on the inner peripheral surface.
The leaf spring 17 is a disc-shaped spring member made of phosphor bronze or the like provided with a plurality of cutout grooves 17k surrounded by an arc-shaped smooth curve, and an inner ring portion 17a fixed to the holder 14, The outer ring part 17b fixed to the case 16 and the collar part 17c which connects the inner ring part 17a and the outer ring part 17b are provided. The flange portion 17 c becomes a spring portion of the leaf spring 17.
The upper leaf spring 17A connects the upper surface of the holder 14 and the yoke support member 16b of the case 16, and the lower leaf spring 17B protrudes from the lower surface of the holder 14 and the four corners of the base portion 16a of the case 16. The holder 14 and the case 16 are connected to each other by being attached to the upper surface of the spring attachment member 16p.

In this example, when the driving coil 15 is mounted on the holder 14, one end of a conductive wire such as copper coated with an insulating film is bound to a binding member 18 </ b> A provided on the upper side of the holder 14. After winding around the outer periphery a predetermined number of times, it is tied to the binding member 18B provided on the lower side of the holder 14, and the lead wire that has been wound is cut. Then, pre-solder is applied to the leaf springs 17A and 17B side of the tangled portions of the conductive wires entangled with the upper and lower tying members 18A and 18B, respectively, and the insulating coating is removed. As a result, as shown in FIG. 2 (a), at least the conductive wire on the side of the upper leaf spring 17A is exposed at the binding portion 19n of the terminal 19A on the winding start side, which is shown in FIG. 2 (b). Thus, the binding portion 19n of the terminal 19A on the winding start side and the holder 14 side of the upper leaf spring 17A (the outer peripheral side of the inner ring portion 17a or the connecting piece 17j between the inner ring portion 17a and the flange portion 17c) Then, the terminal 19A on the winding start side of the drive coil 15 and the upper leaf spring 17A can be electrically connected by fixing with an adhesive. Reference numeral 20 in the figure denotes an adhesive layer.
The terminal 19B on the winding end side of the driving coil 15 and the lower leaf spring 17B can be electrically connected by the same method.
It should be noted that the terminal 19 of the driving coil 15 and the leaf spring 17 can be more reliably electrically connected by covering the entire conductive wire of the binding portion 19n from which the coating has been removed with solder during preliminary soldering.
Further, since the upper and lower leaf springs 17A and 17B are both made of a conductor, the upper and lower leaf springs 17A and 17B are connected to a power source line connected to a driving power source (not shown), so that the driving coil 15 is connected. It can be energized.

  As described above, in the first embodiment, the binding members 18A and 18B made of an insulating material are provided on the upper and lower sides of the driving coil 15 on the outer peripheral side wall of the holder 14, and the binding members 18A and 18B are projected. After the ends 19A and 19B of the driving coil 15 are entangled with each other, the insulating coating of the entangled portion 19n is removed, and then the entangled portion 19n of the ends 19A and 19B and the inner ring portion 17a or the connecting piece of the leaf springs 17A and 17B are connected. Since it has been fixed with an adhesive while being in contact with 17j, the driving coil 15 and the leaf springs 17A, 17B can be electrically connected without damaging the terminals 19A, 19B of the driving coil 15. Further, by taking such a connection form, the adverse effects on the leaf springs 17A and 17B and the holder 14 can be greatly reduced, so that the reliability of the lens driving device 10 can be improved.

In the first embodiment, the driving coil 15 and the leaf spring 17 are fixed to each other by fixing the terminal 19 of the driving coil 15 with the conductive wire exposed to the leaf spring 17 with an adhesive. Although electrically connected, as shown in FIG. 3, even if the winding end terminal 19A and the upper leaf spring 17A of the driving coil 15 with the conductive wire exposed are directly soldered, The terminal 19A on the winding start side of the coil 15 and the upper leaf spring 17A can be reliably electrically connected. Reference numeral 21 in the figure denotes a solder portion. The winding end terminal 19B of the driving coil 15 and the lower leaf spring 17B are also electrically connected in the same manner.
In this case, unlike the conventional soldering, unlike the case where the tip end portion of the terminal 19 of the driving coil 15 is soldered to the inner ring portion 17a or the connecting piece 17j of the leaf spring 17, the binding member 18 is entangled. The tangled portion 19n only needs to be soldered and fixed to the leaf spring 17 in the state where the tangled portion 19n of the driving coil 15 with the exposed conductive wire exposed and the leaf spring 17 are in contact with each other. The terminal 19 of the coil 15 is not damaged. Further, since the soldering operation is easy, there is no adverse effect on the leaf spring 17 and the holder 14.
Further, the same effect can be obtained even when the conductive wire from which the coating has been removed and the leaf spring 17 are joined by welding or bonded with a conductive adhesive.

As a method of electrically connecting the terminal 19 of the drive coil 15 and the leaf spring 17, in addition to the above example, for example, as shown in FIG. There is a method of providing a plating layer 22m and providing an electrical connection region 22n made of a plating layer. The electrical connection region 22n is provided across the side wall of the holder 14 from the location where the inner ring portion 17a of the plate spring 17A of the holder 14 is attached, and is electrically connected to the terminal side plating layer 22m.
As a result, as shown in FIG. 4B, when the leaf spring 17A is attached to the holder 14, the binding portion 19n where the conductor of the terminal 19 of the driving coil 15 is exposed is connected to the terminal side plating layer 22m and the electrical connection. Since it is electrically connected to the leaf spring 17A via the region 22n, the winding start side terminal 19A of the drive coil 15 and the upper leaf spring 17A can be easily electrically connected. At this time, if the electrical connection region 22n and the leaf spring 17 are soldered, the terminal 19A of the drive coil 15 and the leaf spring 17A can be reliably electrically connected. Reference numeral 23 in the figure is a solder portion. The winding end terminal 19B of the driving coil 15 and the lower leaf spring 17B are also electrically connected in the same manner.

As shown in FIG. 5, when the upper leaf spring 17 </ b> A is divided into two, both the binding members 18 </ b> L and 18 </ b> R can be provided on the upper side of the holder 14.
In this example, the spring holding portion 14H of the holder 14 is divided into a right spring holding portion 14R for attaching the inner ring portion 17a of the right leaf spring member 17R and a left spring holding portion 14L for attaching the inner ring portion 17a of the left leaf spring member 17L. In addition to the division, electrical connection surfaces 14A and 14B made of, for example, plating layers are formed on the left and right spring holding portions 14L and 14R. Thus, if the terminals 19A and 19B of the driving coil 15 entangled with the binding members 18L and 18R and the electrical connection surfaces 14A and 14B are connected by soldering, welding, or adhesion, the driving coil 15 The terminals 19A and 19B and the left and right leaf spring members 17L and 17R of the upper leaf spring 17A can be electrically connected.
When the lower leaf spring 17B is divided into two, if both the binding members 18L and 18R are provided on the lower side of the holder 14, the terminals 19A and 19A of the drive coil 15 are similarly provided. 19B and the left and right leaf spring members 17L and 17R of the lower leaf spring 17B can be electrically connected to each other.

Embodiment 2. FIG.
In the above example, the binding member 18 is made of an insulating material such as resin, which is the same as the material forming the holder 14, but may be made of a conductor. Thereby, the terminal 19 of the driving coil 15 and the leaf spring 17 can be more easily electrically connected.
FIG. 6 is a diagram showing an example of this. A binding member insertion hole 14h is provided on a side surface of the upper and lower spring holding portions 14H on the drive coil 15 side provided in the holder 14, and a conductor is inserted into the binding member insertion hole 14h. The binding members 18P and 18Q are inserted and fixed.
Thus, after the ends 19A and 19B of the driving coil 15 are entangled with the upper and lower tying members 18P and 18Q, respectively, if the insulation coating is removed by applying preliminary solder to the tangled portion of the conductive wire, the driving coil 15 The terminals 19A and 19B and the binding members 18P and 18Q are electrically connected. Therefore, for example, as shown in FIG. 7, if the binding members 18P and 18Q and the upper and lower spring members 17A and 17B are soldered, the terminal 19 and the leaf spring 17 of the driving coil 15 are reliably electrically connected. Can connect. Reference numeral 24 in the figure is a solder portion.
Note that the terminal 19 of the driving coil 15 and the leaf spring 17 may be electrically connected by welding or adhesion. However, when bonding, it is necessary to provide the binding members 18P and 18Q at a position where the terminal 19 of the driving coil 15 and the leaf spring 17 are in contact with each other.

In the second embodiment, the case where the binding members 18P and 18Q projecting in the direction of the permanent magnet 12 from the side surface of the holder 14 has been described. However, as shown in FIG. The upper and lower spring holding portions 14H (see FIG. 6) that hold the spring member 17 are composed of a plurality of spring holding portions 14t, and an envelope formed of a conductor protruding in the spring member 17 direction between the spring holding portions 14t. A bald member 18D may be provided so as to electrically connect the spring member 17 with the surface 18m on the spring member 17 side of the binding member 18D.
In this case, as shown in FIG. 8B, the upper binding member 18D, the lower binding member (not shown), and the upper and lower spring members 17A and 17B (only the upper spring member is shown in the figure) are soldered. If attached, the terminal 19 of the drive coil 15 and the leaf spring 17 can be reliably electrically connected. Reference numeral 24 in the figure is a solder portion.
The terminal 19 of the drive coil 15 and the leaf spring 17 may be electrically connected by welding or adhesion.

  Further, as shown in FIG. 9A, the binding member includes a horizontal piece 18x protruding from the side surface of the holder 14 toward the permanent magnet 12 and a vertical piece 18z protruding upward from the horizontal piece 18x. A bald member 18L may be used. In this case, the end 19 of the driving coil 15 may be entangled with the horizontal piece 18x, and the spring 18 may be electrically connected to the surface 18n of the vertical piece 18z on the spring member 17 side.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the embodiment. It is apparent from the claims that the embodiments added with such changes or improvements can also be included in the technical scope of the present invention.

  As described above, according to the present invention, not only does the terminal of the driving coil not be damaged, but also the deterioration of the spring member due to the heat of the soldering iron and the melting of the holder can be greatly reduced. The terminal of the driving coil can be easily connected with good reproducibility. Therefore, the lens driving device can be stably operated and the reliability of the lens driving device can be improved.

10 lens driving device, 11 yoke, 12 permanent magnet, 13 lens,
14 lens holder, 15 driving coil, 16 case, 16a base,
16b Yoke support member, 17, 17A, 17B Leaf spring, 17a Inner ring part,
17b outer ring part, 17c collar part, 17k notch groove, 17j connecting piece,
18, 18A, 18B Tying member, 19, 19A, 19B Driving coil terminal,
19n Tying part of terminal, 20 adhesive layer.

Claims (6)

A holder for holding a lens, a driving coil mounted on an outer peripheral side wall of the holder, a permanent magnet disposed on the outer peripheral side of the driving coil so as to face the driving coil with a gap therebetween, A lens driving device including a case for holding the permanent magnet, and a leaf spring for connecting the holder and the case,
The holder is provided with a binding member for projecting the end of the driving coil, protruding from the holder,
A lens driving device, wherein a terminal of a driving coil entangled with the binding member and a holder side of the leaf spring are electrically connected.   The end of the driving coil entangled with the binding member and the holder side of the leaf spring are connected via a solder layer or a conductor plating layer provided between the holder side of the leaf spring and the binding member. The lens driving device according to claim 1, wherein the lens driving device is electrically connected.   The lens driving device according to claim 1, wherein a terminal of the driving coil entangled with the binding member and a holder side of the leaf spring are electrically connected by welding.   The lens driving device according to claim 1, wherein the binding member is a conductor.   The binding member and the leaf spring holder side are electrically connected via a solder layer or a conductor plating layer provided between the leaf spring holder side and the binding member. The lens driving device according to claim 4, wherein   The lens driving device according to claim 4, wherein the binding member and the holder side of the leaf spring are electrically connected by welding.

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