Lens drive device, camera device and electronic device

Abstract

To provide a lens driving device that can obtain stable driving characteristics, a camera device, and an electronic apparatus.SOLUTION: A lens driving device 10 has: a stationary body 12 that has a base 64; a movable body 14 that has a lens support 16 supporting a lens; and a driving mechanism that drives the movable body 14 with respect to the stationary body 12. The base 64 has a base main body, and a metal support plate provided on the base main body. The support plate is formed with column parts 76 erected in an optical axis direction of the lens, and at least one component constituting the driving mechanism is supported with the column parts 76.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a lens driving device, a camera device, and an electronic device. [Background technology]

[0002] Electronic devices such as mobile phones and smartphones are equipped with small cameras. This type of small camera has a lens driving device, and as this lens driving device, for example, one with an autofocus function is known, as shown in Patent Document 1. The autofocus function is realized by moving a moving body having a lens support that supports a lens relative to a fixed base. The lens driving device is provided with a driving mechanism for driving the moving body relative to the base. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China Utility Model No. 210742590 Specification Summary of the Invention [Problem to be solved by the invention]

[0004] In the above conventional driving mechanism, support columns are molded from resin and are attached to the four corners of the base so that they rise in the direction of the optical axis, and a substrate is attached to the support columns. Components that make up the driving mechanism, such as a coil, are fixed to the substrate. A magnet is provided on the fixed body side so as to face the coil.

[0005] However, the components that make up this drive mechanism were supported via resin support columns that rose up integrally with the base. This meant that shrinkage during molding of the base could cause the support columns to deform or collapse, changing the positional relationships between the components of the drive mechanism from the original design, making it impossible to obtain stable drive characteristics.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS The present invention has an object to provide a lens driving device, a camera device, and an electronic device that can solve the above problems and obtain stable driving characteristics. [Means for solving the problem]

[0007] One aspect of the present invention is a lens driving device which has a fixed body having a base, a movable body having a lens support which supports a lens, and a driving mechanism which drives the movable body relative to the fixed body, wherein the base has a base main body and a metal support plate provided on the base main body, and the support plate has a support portion which rises in the optical axis direction of the lens, and at least one component which constitutes the driving mechanism is supported via the support portion.

[0008] Preferably, at least one component constituting the drive mechanism is fixed to a flexible printed circuit board, and the flexible printed circuit board is fixed to the support. Also, preferably, at least one component constituting the drive mechanism is a coil or a position detection element. Also, preferably, the base is formed in a quadrangle shape when viewed from the optical axis direction of the lens, the support parts are provided at the four corners of the base, and the flexible printed circuit board is bent at the support parts. Also, preferably, at least one component constituting the drive mechanism is a coil, a magnet, or a position detection element. Also, preferably, the support part is formed by bending the support plate. Also, preferably, the lens support has a guide shaft that guides the movement of the lens support in the optical axis direction, and the guide shaft is fixed to the support plate. Even more preferably, the support plate is embedded in the base body.

[0009] Another aspect of the present invention is a camera device, the camera device having the lens drive device and a lens supported by the lens support.

[0010] Yet another embodiment of the present invention is an electronic device, the electronic device including the camera device described above. Effect of the Invention

[0011] According to the present invention, at least one of the components constituting the drive mechanism is supported via a metal support portion provided on the base, thereby improving the positional accuracy of the components constituting the drive mechanism and providing a lens drive device, camera device, and electronic device that can obtain stable drive characteristics. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of a lens driving device according to an embodiment of the present invention, as viewed obliquely from the front. [Diagram 2] 1 is a perspective view of a lens device according to an embodiment of the present invention, as viewed obliquely from behind; [Diagram 3] 1 is an exploded perspective view of a lens driving device according to an embodiment of the present invention, with a fixed body and a movable body disassembled, as viewed obliquely from the front. [Figure 4] 1 is an exploded perspective view of a lens driving device according to an embodiment of the present invention, with all components disassembled, as viewed obliquely from the front. [Diagram 5] 1 is an exploded perspective view of a lens driving device according to an embodiment of the present invention, with all components disassembled, as viewed obliquely from the rear. [Figure 6] 1 is an exploded perspective view of a fixed body used in a lens driving device according to an embodiment of the present invention, disassembled into a base and a flexible printed circuit board, as viewed obliquely from the front. FIG. [Figure 7] 1 is an exploded perspective view of a fixed body used in a lens driving device according to an embodiment of the present invention, as viewed obliquely from the front. [Figure 8] 1 is an exploded perspective view of a base used in a lens driving device according to an embodiment of the present invention, disassembled into a base body and a support plate, and viewed obliquely from the front. FIG. [Figure 9] 1 is a plan view showing a part of a lens driving device according to an embodiment of the present invention. [Figure 10] 10 is a cross-sectional view taken along line AA in FIG. 9. [Figure 11] 10 is a cross-sectional view taken along line BB in FIG. 9. [Figure 12]FIG. 4 is an enlarged perspective view showing a guide wall used in the lens driving device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described with reference to the drawings.

[0014] 1 to 5 show a lens driving device 10 according to an embodiment of the present invention. The lens driving device 10 is used together with a lens in a camera device mounted on an electronic device such as a smartphone.

[0015] The lens driving device 10 has a fixed body 12 and a movable body 14 supported so as to be freely movable relative to the fixed body 12. As shown in Figures 4 and 5, the movable body 14 has a lens support 16 that supports a lens (not shown), and a first frame body 18 that surrounds the lens support 16. The lens support body 16 and the first frame body 18 have an approximately rectangular external shape when viewed from the front. In this specification, for convenience, the optical axis direction of the lens is referred to as the Z direction, the direction perpendicular to the optical axis direction is referred to as the X direction, and the direction perpendicular to the Z direction and the X direction is referred to as the Y direction. In addition, the subject side of the optical axis is referred to as the front side, and the opposite side where an image sensor (not shown) is disposed is referred to as the rear side.

[0016] A lens mounting hole 20 that is circular when viewed from the Z direction is formed on the inside of the lens support 16, and a lens is mounted in this lens mounting hole 20.

[0017] The first frame 18 is composed of a first movable body plate 22, a second movable body plate 24, and a first cover 26. The lens support 16, the first movable body plate 22, and the second movable body plate 24 are made of engineering plastics such as liquid crystal polymer (LCP), polyacetal, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, etc. The first cover 26 is made of metal, for example. The first movable body plate 22, the second movable body plate 24, and the first cover 26 are each formed with through holes 28, 30, and 32 for passing light therethrough. The through holes 28, 30, and 32 are each formed in a substantially circular shape.

[0018] The first frame 18 supports the lens support 16 so as to be movable in the Y and X directions. That is, the first frame 18 has an orthogonal support mechanism 34, and the lens support 16 is allowed to move in the X and Y directions via the orthogonal support mechanism 34.

[0019] The orthogonal support mechanism 34 is composed of a first support mechanism 36 and a second support mechanism 38 separated in the Z direction. The first support mechanism 36 is provided rearward in the Z direction and is composed of a first support portion 40 formed as a protrusion protruding in the -Z direction on the rear surface of the first movable body plate 22, and a first guide portion 42 formed as a groove recessed in the -Z direction on the front surface of the second movable body plate 24. The first support portion 40 is fitted into the first guide portion 42. The first support portion 40 and the first guide portion 42 extend in the X direction and are formed in the vicinity of four corners of the first movable body plate 22 and the second movable body plate 24. Since the first support portion 40 and the first guide portion 42 extending in the X direction are fitted together so as to restrict movement in the Y direction, the first movable body plate 22 is free to move only in the X direction relative to the second movable body plate 24.

[0020] The second support mechanism 38 is provided forward in the Z direction and is composed of a second support part 44 formed as a protrusion protruding in the +Z direction on the front surface of the first movable body plate 22, and a second guide part 46 formed as a groove recessed in the +Z direction on the rear surface of the lens support 16. The second support part 44 fits into the second guide part 46. The second support part 44 and the second guide part 46 extend in the Y direction and are formed in the vicinity of four corners of the lens support 16 and the first movable body plate 22. Since the second support part 44 and the second guide part 46 extending in the Y direction are fitted together so as to restrict movement in the X direction, the lens support 16 is movable relative to the first movable body plate 22 only in the Y direction.

[0021] Mounting portions 48 are provided at the four corners of the first cover 26 so as to extend rearward in the Z direction. Square mounting holes 50 are formed in the mounting portions 48. Mounted portions 52 are formed at the four corners of the second movable body plate 24 so as to protrude laterally. The mounting holes 50 fit into the mounted portions 52, and the first cover 26 is fixed to the second movable body plate 24.

[0022] A first magnet 54 and a first yoke 56 are fixed to the +X side and -Y side surfaces of the outer side of the lens support 16. The first magnet 54 on the +X side surface has an S pole and an N pole formed in the X direction. Also, the first magnet 54 on the -Y side surface has an S pole and an N pole formed in the Y direction.

[0023] A second magnet 58 and a second yoke 60 are fixed to the surface on the +Y side of the second movable body plate 24. The second magnet 58 is divided into two in the Z direction, with an S pole and an N pole formed in the Y direction, and the polarities are reversed at the front and rear. A magnetic member 86 is fixed to the bottom surface of the second movable body plate 24 in correspondence with the rear of the first magnet 54. As a result, the lens support 16 is attracted to the second movable body plate 24 together with the first movable body plate 22, and the movable body 14 is assembled into a single member.

[0024] Next, the relationship between the fixed body 12 and the movable body 14 will be described. The fixed body 12 has a second frame 62. This second frame 62 surrounds the periphery of the first frame 18 of the movable body 14. This second frame 62 has a base 64 and a second cover 66 attached to this base 64. The base 64 and the second cover 66 are rectangular when viewed from the front, and the second frame 62 is configured by fitting the second cover 66 to the outside of the base 64. In addition, through holes 72, 74 for passing light or inserting a lens are formed in a bottom surface portion 68 of the base 64 and a front surface portion 70 of the second cover 66.

[0025] Further, at the four corners of the base 64, a support portion 76 is formed that is divided into two parts with the corners in between, rising forward from the bottom surface portion 68. A flexible printed circuit board 78 is disposed on the outside of the base 64 so as to surround this support portion 76. The flexible printed circuit board 78 is bent into a quadrangle so as to surround three sides of the outer shape of the base 64 and fixed to the support portion 76, and a terminal portion 80 is formed at the rear portion. The supply of electricity to a first coil 82 and a second coil 84, which will be described later, is controlled via this terminal portion 80, but the present invention is not limited to this.

[0026] A first coil 82 is fixed to the +X direction portion and the -Y direction portion on the inner side of the flexible printed circuit board 78. A second coil 84 is fixed to the +Y direction portion on the inner side of the flexible printed circuit board 78. The first coil 82 faces the first magnet 54. The second coil 84 faces the second magnet 58. A position detection element 124 that detects the position of the moving object 14 is provided within the first coil 82. In this embodiment, the coil and position detection element are provided on the fixed body 12 side and the magnet is provided on the movable body 14 side, but it is also possible to provide the magnet on the fixed body 12 side and the coil and position detection element on the movable body 14 side.

[0027] Furthermore, a magnetic member 86 made of a magnetic material is provided on the outside of the +Y direction portion of the flexible printed circuit board 78. This magnetic member 86 faces the second magnet 58 with the flexible printed circuit board 78 and the second coil 84 sandwiched between them. Since magnetic flux from the second magnet 58 flows through the magnetic member 86, an attractive force is generated between the second magnet 58 and the magnetic member 86. As a result, an attractive force acts on the movable body 14 in the +Y direction toward the fixed body 12.

[0028] The movable body 14 is supported by an optical axis direction support mechanism 88 so as to be movable in the Z direction relative to the fixed body 12. The optical axis direction support mechanism 88 is composed of a main guide shaft 90 and a sub guide shaft 92 provided on the base 64, and a guide hole 114 and a guide wall 116 provided in the movable body 14.

[0029] The main guide shaft 90 and the sub guide shaft 92 are made of metal, and in this embodiment, are configured as cylinders extending in the Z direction. Although the main guide shaft 90 and the sub guide shaft 92 are circular in cross section in the XY direction, they may be part of a circle, or may be elliptical or polygonal in shape other than a circle.

[0030] The main guide shaft 90 and the auxiliary guide shaft 92 are fixed at the rear end thereof to the vicinity of the -X+Y direction end of the bottom surface portion 68 of the base 64, and at the rear end thereof to the vicinity of both ends in the +X+Y directions of the bottom surface portion 68 of the base 64. They are raised toward the front in parallel with the Z direction.

[0031] 6 to 8, the base 64 is made up of a base body 98 made of resin, and a metal support plate 100 that is located on the bottom surface 68 of the base 64 and embedded in the base body 98. The base 64 is insert molded so that the entire periphery of the support plate 100 is embedded in the base body 98. The support plate 100 is integrally formed with the aforementioned support column portion 76 by bending a part of the support plate 100 forward, and this support column portion 76 protrudes forward from the base body 98.

[0032] The flexible printed circuit board 78 is bent to fit the three sides of the base 64. The flexible printed circuit board 78 is connected to the support pillars 76 at the four corners of the base 64. The flexible printed circuit board 78 has positioning holes 126 formed near the corners, and the support pillars 76 have positioning protrusions 128 protruding outward. The positioning protrusions 128 fit into the positioning holes 126 to position the flexible printed circuit board 78. The flexible printed circuit board 78 has notches 130 cut in the -Z direction at the rear of the three corners. The base body 98 has step portions 132 protruding in the +Z direction at the four corners. The step portions 132 fit into the notches 130. The flexible printed circuit board 78 is fixed to the support pillars 76 via an adhesive or the like in a state where it is positioned relative to the base 64.

[0033] 9 to 12, the main guide shaft 90 and the sub guide shaft 92 each have a guide shaft body 102, a flange portion 104, and an insertion portion 106 integrally formed from the front to the rear. The insertion portion 106 is formed at the rear end of the main guide shaft 90 and the sub guide shaft 92, and the flange portion 104 is formed immediately before the insertion portion 106. The insertion portion 106 is formed thicker than the guide shaft body 102 so that the posture is more stable when assembled, and the flange portion 104 is further formed thicker than the guide shaft body 102 and the insertion portion 106.

[0034] On the other hand, the base 64 has a first insertion hole 108 formed in the support plate 100 and a second insertion hole 110 formed in the base main body 98 so as to surround the periphery of the first insertion hole 108 .

[0035] The insertion portions 106 of the main guide shaft 90 and the auxiliary guide shaft 92 are inserted into a first insertion hole 108 of the support plate 100, and protrude into a second insertion hole 110 of the base body 98. In addition, the flange portions 104 of the main guide shaft 90 and the auxiliary guide shaft 92 are inserted into the second insertion hole 110 of the base body 98, and abut against the support plate 100 around the first insertion hole 108 of the support plate 100.

[0036] The rear ends of the insertion portions 106 of the main guide shaft 90 and the sub guide shaft 92 are crimped to the support plate 100 to form crimped portions 112, and the periphery of the first insertion hole 108 of the support plate 100 is sandwiched between this crimped portion 112 and the flange portion 104, thereby fixing the main guide shaft 90 and the sub guide shaft 92 to the support plate 100. The crimped portion 112 may be formed by normal press working, but may also be formed by a method called high spin or spin crimping in order to reduce the effect of pressure on other parts. High spin or spin crimping is a processing method in which the tip to be processed is crushed with a rotating tool.

[0037] The main guide shaft 90 is inserted into a guide hole 114 formed in the second movable body plate 24. This guide hole 114 is divided into a front side portion and a rear side portion, and the main guide shaft 90 contacts the front side portion and the rear side portion of the guide hole 114. In addition, this guide hole 114 is formed in a V shape that widens in the +Y direction when viewed from the Z direction. As described above, since the movable body 14 is attracted in the +Y direction by the magnetic member 86 and the second magnet 58, the main guide shaft 90 contacts the V-shaped end surface of the guide hole 114 and secures the sliding position.

[0038] The sub guide shaft 92 is sandwiched between two guide walls 116 formed on the second movable body plate 24. The two guide walls 116 are each composed of a surface parallel to the X direction. The guide walls 116 protrude in a flat or curved shape so that the central portions of the guide walls 116 in the Z direction come into contact with the sub guide shaft 92 from the +Y side and the -Y side. Therefore, the sub guide shaft 92 guides the movable body 14 while contacting the protruding portions of the guide walls 116.

[0039] In addition, the sub-guide shaft 92 is formed shorter in the Z direction than the main guide shaft 90. As shown in FIG. 12, the two guide walls 116 are connected at the front via a front connection part 118. In this embodiment, the front connection part 118 is formed so as to close the entire front open part of the guide wall 116. In addition, at the rear of the guide wall 116, the periphery of the guide wall 116 except for the part where the sub-guide shaft 92 is inserted is connected by a rear connection part 120, and the guide wall 116 is box-shaped by the front connection part 118 and the rear connection part 120. Since the guide wall 116 is formed in a box shape in this manner, the strength of the guide wall 116 is improved.

[0040] 10 and 11, the height at which the guide wall 116 abuts against the sub guide shaft 92 is between the heights of the two guide holes 114. Therefore, the front end of the guide wall 116 abutting against the sub guide shaft 92 is always lower than the front end of the front guide hole 114, and the sub guide shaft 92 can be made shorter than the main guide shaft 90 by that amount. This allows the front connection part 118 to be provided so as to cover the front side of the sub guide shaft 92.

[0041] In the above configuration, when electricity is applied to the first coil 82 facing the first magnet 54 on the +X side surface, a Lorentz force in the X direction acts on the first coil 82. Since the first coil 82 is fixed to the base 64, the reaction force acting on the first magnet 54 becomes a driving force for the lens support 16 and the first movable body plate 22, and the lens support 16 and the first movable body plate 22 move in the X direction while being supported by the first support mechanism 36.

[0042] Furthermore, when current is applied to the first coil 82 facing the first magnet 54 on the -Y side surface, a Lorentz force in the Y direction acts on the first coil 82. Because the first coil 82 is fixed to the base 64, the reaction force acting on the first magnet 54 becomes a driving force for the lens support 16, and the lens support 16 moves in the Y direction while being supported by the second support mechanism 38.

[0043] After the lens support 16 has moved in at least one of the X and Y directions, the supply of current to the first coil 82 is stopped. Then, due to the attractive force between the first magnet 54 and the magnetic member 86 and the friction between the first support portion 40 and the first guide portion 42, and between the second support portion 44 and the second guide portion 46, the lens support 16 stops at the position where the supply of current was stopped.

[0044] Next, when electricity is applied to the second coil 84 disposed between the second magnet 58 and the magnetic member 86, a Lorentz force in the Z direction acts on the second coil 84. Since the second coil 84 is fixed to the base 64, the reaction force acting on the second magnet 58 becomes a driving force for the movable body 14, and the movable body 14 moves in the Z direction while being supported by the optical axis direction support mechanism 88.

[0045] When the current supply to the second coil 84 is stopped after the movable body 14 has moved in the Z direction, the movable body 14 stops at the position where the current supply was stopped due to the attractive force between the second magnet 58 and the magnetic member 86 and the friction between the main guide shaft 90 and the guide hole 114, and between the sub-guide shaft 92 and the guide wall 116. The position of the moving body 14 in the X and Y directions is detected by a position detection element 124 .

[0046] The first coil 82, the second coil 84, and the position detection element 124 are fixed to a flexible printed circuit board 78, which is fixed to a support column 76 formed integrally with a metallic support plate 100, so that it is possible to reduce the inclination and positional deviation of the first coil 82, the second coil 84, and the position detection element 124 relative to the first magnet 54 and the second magnet 58. This makes it possible to control the position of the moving body 14 with high precision.

[0047] Moreover, the movable body 14 is supported and guided on one side in the Y direction by the main guide shaft 90 and the sub guide shaft 92. The main guide shaft 90 and the sub guide shaft 92 are firmly fixed to the metal support plate 100 by crimping with crimping parts 112, so that the inclination can be suppressed even if the front end is not fixed.

[0048] In addition, the guide walls 116, 116 that guide the auxiliary guide shaft 92 are connected by a front connecting portion 118 and a rear connecting portion 120, thereby improving the strength of the guide walls 116, 116, and reducing the displacement and change in inclination during the movement of the movable body 14 even if the movable body 14 receives an impact due to being dropped or the like.

[0049] In this embodiment, the lens driving device has a focus adjustment function and a camera shake correction function, but it may have only a focus adjustment function, or may be applied to a device further having a zoom function, etc. Also, in this specification, a lens driving device used in a camera device has been described, but the present invention can be applied to other devices. [Explanation of symbols]

[0050] 10 Lens drive unit 12 Fixed body 14 Mobile 16 Lens support 18 First Frame 20 Lens mounting hole 22 First moving body plate 24 Second moving body plate 26 First Cover 28, 30, 32 Through holes 34 Orthogonal support mechanism 36 First support mechanism 38 Second support mechanism 40 1st support part 42 1st Information Department 44 Second support part 46 2nd Information Department 48 Mounting part 50 Mounting hole 52 Mounting part 54 First Magnet 56 First York 58 Second Magnet 60 Second York 62 Second Frame 64-base 66 Second Cover 68 Bottom part 70 Front part 72,74 Through holes 76 Pillar section 78 Flexible Printed Circuit Board 80 Terminal section 82 First coil 84 Second coil 86 Magnetic Materials 88 Optical axis direction support mechanism 90 Main guide shaft 92 Sub-guide shaft 98 Base Body 100 Support plate 102 Guide shaft main body 104 Flange part 106 Insertion part 108 First insertion hole 110 Second insertion hole 112 Crimping part 114 Guide hole 116 Guide Wall 118 Front connection 120 Rear connection 124 Position detection element 126 Positioning hole 128 Positioning protrusion 130 Notch 132 Stepped section

Claims

1. a fixed body having a base; a movable body having a lens support for supporting a lens; a drive mechanism that drives the movable body relative to the fixed body, The base includes a base body and a metal support plate provided on the base body. The support plate is integrally formed with a support column portion that rises in the optical axis direction of the lens, At least one component constituting the drive mechanism is fixed to a flexible printed circuit board, and the flexible printed circuit board is fixed to the support portion, A lens driving device in which the base is formed in a rectangular shape when viewed from the optical axis direction of the lens, the support portions are provided at two sides sandwiching each of the four corners of the base, spaced apart from each other, and the flexible printed circuit board is bent at the support portions.

2. 2. The lens driving device according to claim 1, wherein at least one component constituting the driving mechanism is a coil or a position detection element.

3. 2. The lens driving device according to claim 1, wherein the support plate has a rectangular ring shape that conforms to the rectangular shape of the base, and the support pillars extend from two sides that sandwich each of four corners of the support plate.

4. The lens driving device according to claim 1 , wherein the support portion is formed by bending a part of the support plate.

5. 2. The lens driving device according to claim 1, further comprising a guide shaft for guiding the movement of said lens support in the direction of the optical axis of said lens, said guide shaft being fixed to said support plate.

6. 2. The lens driving device according to claim 1, wherein the support plate is embedded in the base body.

7. 2. A camera device comprising: the lens drive device according to claim 1; and a lens supported by the lens support.

8. An electronic device comprising the camera device according to claim 7.

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