WO2011108430A1

WO2011108430A1 - Lens driving device and camera module

Info

Publication number: WO2011108430A1
Application number: PCT/JP2011/054093
Authority: WO
Inventors: 傑大石; 博司山下; 三生中島
Original assignee: 三洋電機株式会社
Priority date: 2010-03-04
Filing date: 2011-02-24
Publication date: 2011-09-09
Also published as: JPWO2011108430A1

Abstract

Disclosed is a lens driving device that can cause the profile of a camera module to be compact by means of contriving the disposition of terminals for a coil. Further disclosed is a camera module using same. A concavity (16) is formed on the lateral surface of a base (10), and projections (16a) are formed in the concavity (16). In a printed circuit board (40), holes (41) are caused to be penetrated by the projections (16a), fitting the printed circuit board (40) to the concavity (16). In this state, the ends (20a, 20b) of the coil (20) are each wound around the corresponding projection (16a). Thereafter, soldering is performed in a manner so as to join the ends (20a, 20b) of the coil (20) with terminals (42), connecting the ends (20a, 20b) with the terminals (42).

Description

Lens driving device and camera module

The present invention relates to a lens driving device and a camera module including the same.

Conventionally, camera modules are mounted on mobile phones and the like. Such a camera module includes a lens driving device for focus adjustment. The lens driving device displaces the lens in the optical axis direction according to the control signal. Thereby, the focus adjustment with respect to the subject is performed.

As a lens driving device, a moving magnet type lens driving device is known (for example, Patent Document 1). In this type of lens driving device, a magnet is attached to a holder that holds a lens. The holder is supported so as to be displaceable in the optical axis direction of the lens with respect to the base. A coil is arranged on the base so as to face the magnet on the holder side. The holder is driven along with the magnet in the optical axis direction of the lens by an electromagnetic driving force generated by applying a current to the coil.

When such a lens driving device is mounted on a camera module, an image sensor for receiving light collected by the lens is disposed under the base. The image sensor is mounted on a predetermined circuit board, and a lens driving device is disposed thereon.

JP 2008-185749 A

In the lens driving device, a terminal for applying a current to the coil is disposed on the base. Both ends of the coil are connected to two terminals, and a signal line is connected to these terminals from the main body side circuit unit. At this time, if the terminal protrudes from the bottom of the base, it is necessary to provide an interval corresponding to the protruding amount of the terminal between the circuit board disposed below the base and the base. Due to this distance, the dimension from the circuit board to the upper surface of the lens driving device becomes large, causing a problem that the outer shape of the camera module becomes large.

The present invention has been made to solve such a problem, and provides a lens driving device capable of making the outer shape of a camera module compact by devising the arrangement of coil terminals, and a camera module using the lens driving device. For the purpose.

The first aspect of the present invention relates to a lens driving device. A lens driving device according to this aspect includes a base, a holder that holds the lens and is supported so as to be displaceable in the optical axis direction of the lens with respect to the base, a magnet mounted on the holder, and a magnet A coil mounted on the base so as to face each other; and a terminal board electrically connected to the coil and provided with a terminal portion for applying a current to the coil. A concave portion is formed in the side surface of the base, and the terminal board is mounted in the concave portion so that the lower end does not protrude from the lower surface of the base.

The second aspect of the present invention relates to a camera module. A camera module according to this aspect applies a control signal to the lens driving device according to the above aspect, an image sensor that receives light collected by the lens, a circuit board on which the image sensor is mounted, and the coil. And a control unit. A housing portion having a depth for housing the image sensor is formed on the lower surface of the base. The recess is formed at a position corresponding to the housing portion on the side surface of the base, and the coil is wound around the optical axis of the lens on the side surface of the base above the recess. Installed. The lens driving device is installed on the circuit board so that the imaging element is accommodated in the accommodating portion of the base.

According to the present invention, the shape of the camera module in the optical axis direction of the lens can be reduced, and the outer shape of the camera module can be made compact.

The effect or significance of the present invention will become more apparent from the following description of embodiments. However, the following embodiment is merely an example when the present invention is implemented, and the present invention is not limited to what is described in the following embodiment.

It is a figure which shows the structure of the lens drive device which concerns on embodiment. It is a figure which shows the structure of the base which concerns on embodiment. It is a figure explaining the attachment method of the holder which concerns on embodiment, and the connection method of the coil with respect to a printed circuit board. It is a figure which shows the attachment form of the magnetic board which concerns on embodiment. It is a figure explaining operation | movement of the lens drive device which concerns on embodiment. It is a figure which shows the structure of the camera module which concerns on embodiment. It is a figure explaining the installation method of the lens drive device with respect to the circuit board which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a lens driving device. FIG. 1A is an exploded perspective view of the lens driving device. FIG. 1B is a perspective view showing the configuration of the lens driving device before the cover 100 is attached, and FIG. 1C is a perspective view of the lens driving device with the cover 100 attached. . In the present embodiment, the lens is not shown for convenience.

Referring to FIG. 1, the lens driving device includes a base 10, a coil 20, magnetic plates 31 and 32 (the magnetic plate 32 is not shown in FIG. 1), a printed circuit board 40, a filter 50, and a holder 60. A magnet 70, a shaft holder 80, a shaft 90, and a cover 100.

The base 10 has a square shape with chamfered corners in plan view. A series of coils 20 are attached to the base 10 in two stages. The winding direction of the coils 20 at each stage is opposite to each other.

Magnetic plates

31 and 32 are bonded to the outer surface of the coil 20. A printed circuit board 40 is attached to the side surface of the base 10, and two ends of the coil 20 are soldered to the printed circuit board 40. Further, a step (not shown) is formed on the back surface of the base 10, and the filter 50 is attached to the step. The filter 50 is an infrared ray removal filter.

The holder 60 has an octagonal shape in plan view. A circular opening 61 for accommodating the lens barrel is formed in the holder 60 at the center position. The optical axis of the lens coincides with the center of the octagon defined by the outer shape of the holder 60 in plan view. The eight side surfaces of the holder 10 are arranged so as to be symmetric with respect to the optical axis of the lens mounted in the opening 61. Of these eight side surfaces, magnets 70 are mounted on four side surfaces that are not adjacent to each other.

The four magnets 70 are, for example, sintered magnets made of neodymium or the like, and have a two-pole arrangement structure in which N and S are magnetized on one side. The size and magnetic strength of each magnet 70 are equal to each other. Further, each magnet 70 is arranged at a position where the center thereof is shifted upward by a certain distance from the center of the corresponding side surface. The two magnets 70 are arranged symmetrically with respect to the optical axis of the lens, and the remaining two magnets 70 are also arranged symmetrically with respect to the optical axis of the lens.

The holder 60 is formed with holes 62 and kerfs 63 at diagonal positions. A shaft 90 is passed through the hole 62 and the cut groove 63, and the holder 60 is supported so as to be displaceable in the optical axis direction of the lens. The shaft 90 is made of a metal member and has a circular cross section.

The cover 100 has a square shape with chamfered corners in plan view. The outer shape of the cover 100 in plan view is substantially equal to the outer shape of the base 10. The shape of the inner surface of the cover 100 in plan view is substantially the same as the outer shape of the portion of the base 10 where the coil 20 and the

magnetic plates

31 and 32 are mounted. The cover 100 is formed with an opening 101 through which light passes. In addition, a collar portion 102 and a hole 102a are formed on the side surface of the cover 100, and foot portions 103 are formed at four corners, respectively.

2A is a perspective view showing the configuration of the base 10, FIG. 2B is a perspective view when the base 10 is viewed from above, and FIG. 2C is the vicinity of the locking piece 16b of the base 10. It is the figure which looked at the part from the upper side. As illustrated, the base 10 is made of a frame-shaped member. The base 10 is formed with an opening 11 for allowing light to pass through. Further,

coil mounting portions

12 a and 12 b for winding the coil 20 are formed on the side surface of the base 10 over the entire circumference.

A shaft holding portion 13 is formed on the upper surface of the base 10, and a hole 13 a for press-fitting the shaft 90 is formed in the shaft holding portion 13. A hole 13b for press-fitting the shaft 90 is formed at a position coaxial with the hole 13a.

Referring to FIG. 5B, a receiving portion 14 to which the shaft holder 80 is attached is formed on the upper surface of the base 10 at a position that is diagonally related to the shaft holding portion 13. The receiving portion 14 is formed with a hole portion 14a that fits with the protrusion 83 (see FIG. 3A) of the shaft holder 80. Further, in the vicinity of the receiving portion 14, a notch 14 b that engages with the flange portion 81 of the shaft holder 80 is formed. Further, a hole 14 c into which the shaft 90 is press-fitted is formed below the receiving portion 14. When the shaft holder 80 is attached to the receiving portion 14, the hole 14c faces the hole 82 (see FIG. 3A) of the shaft holder 80.

Referring to FIG. 2A, a step portion 15 is formed on the side surface of the base 10, and a locking piece 15 a is formed on the step portion 15. Further, a recess 16 is formed on the other side surface of the base 10, and two protrusions 16 a are formed in the recess 16. Two locking pieces 16 b are formed above the recess 16. As shown in FIG. 5C, each of the two locking pieces 16b has an inclined surface on the right side. When the coil 20 is mounted on the printed circuit board 40, the intermediate portion of the coil 20 is locked to the inclined surface.

As shown in FIG. 2A, the printed circuit board 40 has two holes 41 at positions corresponding to the two protrusions 16a. Further, the terminal portion 42 is exposed to the outside from around the hole 41 to the lower end. The protrusions 16 a are inserted into the two holes 41 and the printed circuit board 40 is mounted in the recess 16. Details of the mounting method of the printed circuit board 40 will be described later with reference to FIG.

Also, a groove 17 is formed in the base 10 above the step portion 15. The groove 17 functions as an adhesive reservoir groove when the magnetic plate 31 is bonded to the outer surface of the coil 20 as will be described later. Grooves 18 functioning as an adhesive reservoir groove when another magnetic plate 32 is bonded are also formed on the other side surface (see FIG. 4B). Further, stepped portions 10 a that contact the foot portions 103 of the cover 100 are formed at the four corners of the lower portion of the base 10.

At the time of assembly, first, the printed circuit board 40 is mounted in the recess 16 of the base 10 shown in FIG. Further, the coil 20 is mounted and the end of the coil 20 is soldered to the printed circuit board 40. Thereafter, the holder 60 to which the lens and the magnet 70 are attached is accommodated in the frame of the base 10 from above the base 10.

FIG. 3A is a diagram illustrating a state in which the holder 60 is accommodated in the base 10. As shown in the figure, the two

end portions

20a and 20b of the coil 20 reach the printed circuit board 40 via the locking pieces 16b. The arrows in the figure indicate the winding direction of the coil 20.

FIG. 3 (c) is a diagram showing a state in which the

end portions

20a and 20b of the coil 20 are mounted. After the printed circuit board 40 is fitted in the recess 16, the end 20a of the coil 20 is wound around the left protrusion 16a. Thereafter, the end 20a is hung on the inclined surface of the left locking piece 16b shown in FIG. 2A (see FIG. 2C), and clockwise (see FIG. 2C) on the coil mounting portion 12b on the lower side of the base 10. It is wound in the direction of the arrow on the lower side of FIG. When the winding to the lower coil mounting portion 12b is finished, the coil 20 is wound around the upper coil mounting portion 12a in the counterclockwise direction (the arrow direction on the upper side in FIG. 3A). When the winding to the upper coil mounting portion 12a is finished, the end 20b of the coil 20 is hung on the inclined surface of the right locking piece 16a (see FIG. 2 (c)), as shown in FIG. 3 (c). And wound around the right protrusion 16a. Thereafter, soldering is performed so as to connect the

end portions

20a and 20b wound around the protrusion 16a and the terminal portion 42 corresponding to each end portion. Thus, the coil 20 and the terminal portion 42 are electrically connected. Note that the printed circuit board 40 is fastened so as not to come out of the recess 16 by soldering. In this state, the printed circuit board 40 and the recess 16 may be bonded and fixed.

Thereafter, the shaft holder 80 is attached to the receiving portion 14 so that the protrusion 83 is fitted into the hole 14a on the base side (see FIG. 2B). At this time, the flange portion 81 of the shaft holder 80 is engaged with the notch 14 b on the upper surface of the base 10.

FIG. 3B is a view showing a state in which the shaft holder 80 is thus attached to the receiving portion 14. In this state, the

holes

13a and 13b and the hole 62 of the holder 60 are aligned, and one shaft 90 is press-fitted from the hole 13a. The tip of the shaft 90 is press-fitted into the hole 13a, passes through the hole 62, and is then press-fitted into the hole 13b (see FIG. 2A). In this state, the rear end of the shaft 90 is supported by the hole 13a. Thus, the mounting of one shaft 90 to the base 10 and the engagement between the shaft 90 and the hole 62 are completed.

Further, in this state, the hole 82 of the shaft holder 80, the hole 14c of the base 10 (see FIG. 2B), and the kerf 63 of the holder 60 (see FIG. 1A) are aligned, and the other The shaft 90 is press-fitted from the hole 82. The tip of the shaft 90 is press-fitted into the hole 82, passes through the kerf 63, and is then press-fitted into the hole 13c. In this state, the rear end of the shaft 90 is supported by the hole 82. Thus, the mounting of the other shaft 90 to the base 10 and the engagement between the shaft 90 and the kerf 63 are completed.

Thus, by attaching the two shafts 90, the holder 60 is attached to the base 10 so as to be displaceable in the optical axis direction of the lens. Thereafter, the two

magnetic plates

31 and 32 are bonded to the outer surface of the coil 20.

4 (a) and 4 (b) are diagrams showing the mounting state of the

magnetic plates

31 and 32. FIG. 1A is a perspective view when the lens driving device is viewed from substantially the same angle as FIG. 1B, and FIG. 1B is a perspective view of the lens driving device from the state of FIG. It is a perspective view of the state rotated about 90 degrees in the counterclockwise direction about the axis. As shown in FIG. 2B, a magnetic plate 32 is bonded to the outer surface of the coil 20 in addition to the magnetic plate 31. The magnetic plate is not attached to the other side surface other than the two side surfaces in FIG. A groove 18 is formed in the vicinity of the magnetic plate 32 of the base 10. At the time of bonding of the

magnetic plates

31 and 32, the

grooves

17 and 18 function as an adhesive reservoir groove.

When the two

magnetic plates

31 and 32 are arranged in this manner, a magnetic force acts between the

magnetic plates

31 and 32 and the magnet 70 (see FIG. 1A) arranged on the holder 60. By this magnetic force, the hole 62 and the cut groove 63 (see FIG. 1A) of the holder 60 are pressed against the shaft 90. Thereby, when the energization to the coil 20 is stopped, the holder 60 is held at the position when the energization is stopped.

After the

magnetic plates

31 and 32 are thus mounted, the cover 100 is mounted on the base from above as shown in FIG. At this time, the flange portion 102 of the cover is fitted into the step portion 15 of the base 10, and the hole 102 a of the flange portion 102 is engaged with the locking piece 15 a of the step portion 15. Further, the foot portion 103 of the cover 100 abuts on the upper surface of the step portion 10 a of the base 10. In this way, the assembly of the lens driving device is completed as shown in FIG. In such an assembled state, the terminal portion 42 of the printed circuit board 40 is exposed to the outside without being covered by the cover 100.

FIG. 5 is a diagram for explaining the driving operation of the lens driving device. This figure schematically shows the A-A 'cross section of FIG. In the figure, a black dot mark on the circle and a cross mark on the circle indicate the direction of current flow. A black dot mark on the circle indicates a direction toward the drawing reference person, and a cross mark on the circle indicates a direction away from the drawing reference person.

As shown in the figure, the N-pole region of the magnet 70 is opposed to the upper portion 21 of the coil 20, and the S-pole region of the magnet 70 is opposed to the lower portion 22. When a current in the direction shown in FIG. 5A flows through the coil 20, an upward driving force acts on the magnet 70, and the lens holder 60 is displaced upward in the figure. As a result, the lens holder 60 is displaced upward as shown in FIG. In this state, when the application of current is stopped, the holder 60 is pressed against the shaft 90 by the magnetic force between the

magnetic plates

31 and 32 and the magnet 70 and is held at the position when the current application is stopped. 7B, when a reverse current is applied to the coil 20, the lens holder 60 is displaced downward.

In this way, the lens is positioned at the on-focus position by moving the lens holder 60 upward and downward. The home position of the lens holder 60 is a position where the lower surface of the lens holder 60 comes into contact with the base 10.

FIG. 6 is a diagram showing a schematic configuration of a camera module on which the lens driving device having the above configuration is mounted. In the figure, reference numeral 1 denotes a lens driving device.

Below the base 10, a circuit board 200 on which an image sensor 201 is mounted is disposed. The base 10 is provided with a hall element 110 as a position sensor, and the position of the lens holder 60 is detected based on a signal from the hall element 110.

During the focus operation, a CPU (Central Processing Unit) 301 controls the driver 302 to displace the lens holder 60 from the home position to a predetermined position in the lens optical axis direction. At this time, a position detection signal from the Hall element 110 is input to the CPU 301. At the same time, the CPU 301 processes a signal input from the image sensor 201 to acquire a contrast value of the captured image. Then, the position of the lens holder 60 with the best contrast value is acquired as the on-focus position.

Thereafter, the CPU 301 drives the lens holder 60 toward the acquired on-focus position. At that time, the CPU 301 monitors the signal from the hall element 110 and drives the lens holder 60 until the signal from the hall element 110 reaches a state corresponding to the on-focus position. Thereby, the lens holder 60 is positioned at the on-focus position.

FIG. 7 is a diagram for explaining a method of mounting the lens driving device 1 on the circuit board 200. FIG. 4A is a perspective view showing a state before the lens driving device 1 is mounted on the circuit board 200, FIG. 4B is a perspective view of the lens driving device 1 viewed from the back side, and FIG. FIG. 6 is a perspective view showing a state after the lens driving device 1 is mounted on the circuit board 200.

As shown in FIG. 4B, two pins 19 are formed on the lower surface of the base 10 at diagonal positions. In addition, an accommodation portion S having a depth capable of accommodating the image sensor 201 in a state where the filter 50 is mounted is provided on the lower surface of the base. The concave portion 16 is formed at a position corresponding to the accommodating portion on the side surface of the base. Further, as shown in FIG. 3A, a hole 200a is formed in the circuit board 200 at a position corresponding to the pin 19 of the base 10.

The lens driving device 1 is installed on the circuit board 200 from above as shown in FIG. At this time, the two pins 19 of the base 10 are fitted into the two holes 200 a of the circuit board 200. Thereby, the lens driving device 1 is correctly positioned with respect to the image sensor 201. In this state, the lens driving device 1 is bonded and fixed to the circuit board 200. As a result, the lens driving device 1 is installed on the circuit board 200 as shown in FIG.

According to the present embodiment, since the lower end of the printed circuit board 40 does not protrude from the lower surface of the base 10, there is no need to leave a gap between the base 10 and the circuit board 200. Therefore, the shape of the camera module in the optical axis direction of the lens can be reduced, and the outer shape of the camera module can be made compact.

According to the present embodiment, since the lens driving device 1 is mounted on the upper surface of the circuit board 200 so that the image sensor 201 is accommodated in the accommodating portion S of the base 10, the camera module in the optical axis direction of the lens. The shape of the camera module can be further reduced, and the outer shape of the camera module can be made more compass. In addition, since the image sensor 201 is covered by the lens driving device 1, the image sensor 201 can be protected by the lens driving device 1.

Further, according to the present embodiment, as shown in FIG. 3C, the

end portions

20a and 20b of the coil 20 are wound around the protrusion 16a, so that the end of the coil 20 can be easily handled while the coil 20 is being cleaned. The

portions

20 a and 20 b can be positioned at the position of the terminal portion 42 of the printed circuit board 40. Further, by soldering the position of the protrusion 16a, the

end portions

20a and 20b of the coil 20 can be easily connected to the corresponding terminal portions 42.

Further, according to the present embodiment, as shown in FIG. 3 (a), since the intermediate portion of the coil 16b is relayed to the two locking pieces 16b, the two

end portions

20a and 20b are crossed. And can smoothly lead to the corresponding terminal portion 42.

Furthermore, according to the present embodiment, as shown in FIG. 7C, the terminal portion 42 is exposed to the outside without being covered with the cover 100, and therefore, the signal line can be easily attached to the terminal portion 42. be able to. The signal line is attached to the terminal portion 42 by soldering. The signal line may be performed in the state of FIG. 7C or may be performed before the lens driving device 1 is mounted on the circuit board 200.

The embodiment of the present invention has been described above. However, the present invention is not limited to the embodiment described above, and the embodiment of the present invention can be variously modified in addition to the above.

For example, in the above embodiment, as shown in FIG. 7C, the terminal portion 42 is exposed to the outside by not covering the lower portion of the base 10 with the cover 100. The lower part may be covered with the cover 100, and a notch may be provided at a position corresponding to the terminal part 42 of the cover 100 to expose the terminal part 42 to the outside.

Moreover, in the said embodiment, as shown to Fig.3 (a), although the intermediate part of the

edge parts

20a and 20b of the coil 20 was relayed to the locking piece 16b, although two locking pieces 16b are used. Either or both may be omitted, and the

coils

20a and 20b may be directly wound around the corresponding protrusion 16a. In addition, the coil 20 is wound around the

coil mounting portions

12a and 12b of the base 10 before being wound around the two protrusions 16a, and then the printed circuit board 20 is mounted in the recess 16 and the

coil end portions

20a and 20b are wound around the protrusion 16a. It can also be done. In this case, an inclined surface is formed on the left side of the left locking piece 16b shown in FIG. 2C, and an end 20a of the coil 20 is hung on the inclined surface and is wound around the left protrusion 16a.

In the above embodiment, one magnet 70 is disposed on one side surface of the holder 60, but two or more magnets may be disposed on each side surface.

In the above embodiment, the two

magnetic plates

31 and 32 are arranged on the base 10, but one or three or more magnetic plates may be arranged on the base 10. However, in this case as well, as in the above embodiment, it is desirable that the magnetic plate be arranged so that the magnetic force generated between the magnet and the magnetic plate is unbalanced in a plane perpendicular to the optical axis of the lens. .

Furthermore, the shapes of the base 10 and the holder 60 are not limited to the above, and can be changed as appropriate. The diameters of the two shafts 90 may not be the same, and the holder 60 may be guided in the optical axis direction of the lens by a guide mechanism other than the shafts.

In addition, the embodiment of the present invention can be variously modified as appropriate within the scope of the technical idea shown in the claims.

DESCRIPTION OF SYMBOLS 1 ... Lens drive device 10 ... Base 16 ... Recessed part 16a ... Projection 16b ... Locking piece (locking part)
S ... Accommodating part 20 ... Coil 40 ... Printed circuit board (terminal board)
DESCRIPTION OF SYMBOLS 41 ... Hole 42 ... Terminal part 60 ... Holder 70 ... Magnet 100 ... Cover 200 ... Circuit board 201 ... Image sensor (imaging element)
301 ... CPU (control unit)

Claims

Base and
A holder that holds the lens and is supported so as to be displaceable in the optical axis direction of the lens with respect to the base;
A magnet mounted on the holder;
A coil mounted on the base to face the magnet;
A terminal board that is electrically connected to the coil and includes a terminal portion for applying a current to the coil;
A concave portion is formed on a side surface of the base, and the terminal board is mounted so that the lower end of the concave portion does not protrude from the lower surface of the base.
A lens driving device.
The lens driving device according to claim 1,
On the lower surface of the base, a housing portion having a depth for housing the image sensor is formed,
The concave portion is formed at a position corresponding to the accommodating portion on the side surface of the base,
The coil is mounted on the side surface of the base above the recess so as to be wound around the optical axis of the lens.
A lens driving device.
The lens driving device according to claim 1,
A protrusion is formed in a direction perpendicular to the side surface of the base from the recess,
A hole is formed in the terminal board at a position corresponding to the protrusion,
With the terminal board positioned in the recess so as to insert the protrusion into the hole, the end of the coil is wound around the protrusion,
The end of the coil wound around the protrusion is soldered to the terminal portion.
A lens driving device.
The lens driving device according to claim 3,
A locking portion for relaying the coil before the coil reaches the protrusion is formed on a side surface of the base where the concave portion is formed.
A lens driving device.
The lens driving device according to claim 1,
A locking portion for relaying the coil before the coil reaches the protrusion is formed on a side surface of the base where the concave portion is formed.
A lens driving device.
A lens driving device according to claim 2;
An image sensor for receiving the light collected by the lens;
A circuit board on which the image sensor is mounted;
A control unit for applying a control signal to the coil,
The lens driving device is installed on the circuit board so that the imaging element is accommodated in the accommodating portion.
A camera module characterized by that.