JP2017138492A - Lens drive unit, camera device, and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens drive unit comprising a fixed body having a through-hole for passing light transmitting through a lens, a movable body provided with a lens holder for holding the lens and configured to move along a direction of an optical axis of the lens, and a dustproof structure that allows for preventing foreign matter from entering the through-hole when the lens moves, and to provide a camera device and electronic device having the same.SOLUTION: A lens drive is provided with a sealing member disposed to be in contact with an outer peripheral area of a through-hole along an entire circumference of the through-hole and with a movable body, and designed to expand or contract following the movement of the movable body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens driving device used in a camera device mounted on an electronic device such as a mobile phone or a smartphone, a camera device using the lens driving device, and an electronic device.

  As a conventional lens driving device, for example, Patent Document 1 discloses the following lens driving device. In this lens driving device, a skirt portion having an inner dimension slightly larger than the outer shape of the cylindrical projection provided on the base member is provided in a lower portion of the carrier formed in the cylindrical shape, and the cylindrical projection is provided in the skirt portion. It has a structure in which the upper part of the part is accommodated. According to this lens driving device, it is supposed that foreign matters such as dust and dirt can be prevented from entering the image sensor side.

  Patent Document 2 proposes a lens driving device that includes a base having an opening and a filter that is fixed to the opening and has a dam member around the base. Thereby, it is said that defects such as black scratches and spots caused by moving dust generated after assembly can be reduced.

JP 2012-185346 A Japanese Patent Laid-Open No. 2007-60288

  According to the lens driving device proposed in the above patent document, a certain dustproof effect can be expected, but since it is insufficient, an improvement in the dustproof structure of the lens driving device has been demanded.

  Therefore, the present invention provides a lens driving device capable of preventing foreign matter from entering a through hole provided in a fixed body because light transmitted through the lens passes when the lens moves, a camera device including the lens driving device, and An object is to provide electronic equipment.

A fixed body having a through-hole through which light transmitted through the lens passes;
A movable body having a lens holding portion for holding the lens and capable of moving along the optical axis direction of the lens;
A sealing member capable of closing a gap formed between a peripheral portion outside the through-hole and the movable body over the entire circumference of the through-hole and expanding and contracting following the movement of the movable body; And a lens driving device.

  According to the present invention, the sealing member that can be expanded and contracted following the movement of the moving body, the gap formed between the peripheral portion outside the through hole and the moving body is disposed around the entire circumference of the through hole. Therefore, it is possible to provide a lens driving device that can prevent foreign matter from entering the through-hole when the lens moves, and a camera device and electronic apparatus including the lens driving device.

It is a figure showing an example which attached the image pick-up element to the lens drive device concerning the embodiment of the present invention, and (a) is a sectional view and (b) is an enlarged view of A portion. It is a figure showing the state which the moving body of the lens drive device shown in FIG. 1 is moving upwards along an optical axis direction, Comprising: (a) Sectional drawing, (b) It is an enlarged view of A part. It is a figure showing the other example which attached the image pick-up element to the lens drive device which concerns on embodiment of this invention, Comprising: (a) Sectional drawing, (b) It is an enlarged view of B part. It is a figure showing the state which the moving body of the lens drive device shown in FIG. 3 is moving upwards along an optical axis direction, (a) Sectional drawing, (b) It is an enlarged view of B part. It is a figure showing the further another example of what attached the image pick-up element to the lens drive device which concerns on embodiment of this invention, Comprising: (a) Sectional drawing, (b) It is an enlarged view of C part. 6A and 6B are diagrams illustrating a state in which the moving body of the lens driving device illustrated in FIG. 5 is moving upward along the optical axis direction, in which FIG. 5A is a cross-sectional view and FIG. It is a figure showing the further another example of what attached the image sensor to the lens drive device concerning the embodiment of the present invention, and (a) is a sectional view and (b) is an enlarged view of D portion. FIG. 8 is a diagram illustrating a state in which the moving body of the lens driving device illustrated in FIG. 7 is moving upward along the optical axis direction, in which (a) is a cross-sectional view and (b) is an enlarged view of a D portion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are assigned to the common components, and the description thereof is omitted.

  As an example, the lens driving device according to the present embodiment is used in an autofocus camera employed in an electronic device such as a mobile phone or a smartphone.

[Configuration of lens driving device]
Description will be made with the upper side in FIG. The vertical direction in the figure is the optical axis direction of the lens (not shown), the upper side is the subject side, and the lower side is the image sensor side.

  First, the configuration of the main body portion of the lens driving device 1 of the present embodiment will be described. In FIG. 1, the lens driving device 1 includes a frame 4, an upper spring 9, a yoke 5, a magnet 6, a coil 8, a lens carrier 7, a lower spring 10, and a base 2. In order to easily understand the influence of foreign matter such as dust and dust, which will be described later, in FIG. Is shown. In the lens driving device 1, the base 2, the yoke 5, the magnet 6 and the frame 4 constitute a fixed body. The lens carrier 7 and the coil 8 constitute a moving body that moves along the optical axis direction with respect to the fixed body.

  The lens carrier 7 is a cylindrical body, and a lens holding portion 7a is formed on the inner peripheral side of the cylindrical body. A lens (not shown) is held by the lens holding portion 7a. The lens carrier 7 has a contact portion 19 that protrudes downward from the lower surface thereof. The contact portion 19 contacts the contacted portion 23 of the base 2.

  The base 2 is a plate-like body and includes a through hole 3 through which light transmitted through a lens (not shown) held by a lens carrier 7 passes. A yoke 5 is attached above the base 2. An imaging element 11 is disposed below the through hole 3. The base 2 is attached above the substrate 24 to which the image sensor 11 is attached. An IR filter 12 is disposed above the image sensor 11 so as to close the through hole 3. For this reason, even if foreign matter such as dust or dirt falls into the through-hole 3, it falls on the IR filter 12, so that it does not fall on the image sensor 11 and have a fatal effect on the image quality. In addition, the base 2 is good also considering the part to which the yoke 5 is attached, and the part to which the IR filter 12 and the board | substrate 24 are attached as a different body.

  The frame 4 is a plate-like body and is provided with a hole through which light passes at a position corresponding to the through hole 3 of the base 2. The frame 4 is attached to the upper side wall of the yoke 5.

  The yoke 5 has an outer peripheral side wall extending in the optical axis direction, an upper side wall extending from the upper end of the outer peripheral side wall to the inner peripheral side, and an inner peripheral side wall extending downward from the inner end of the upper side wall. The lower side of the outer peripheral side wall is attached to the upper side of the base 2. Further, holes for allowing light to pass through are provided at locations corresponding to the through holes 3 of the base 2. This hole is constituted by the inner end of the upper side wall and the inner peripheral side wall.

  A driving magnet 6 is fixed inside the outer peripheral side wall constituting the yoke 5.

  The coil 8 is annular and fixed to the lens carrier 7. In the illustrated embodiment, a flange portion is formed radially outward on the lower end side of the cylindrical lens carrier 7. The coil 8 is fixed to the upper side of the flange, and the outer peripheral surface on the radially outer side of the coil 8 faces the inner peripheral surface on the radially inner side of the magnet 6.

  The upper spring 9 has an inner peripheral side portion fixed to the upper side of the lens carrier 7 as a moving body, an outer peripheral side portion fixed to the fixed body at a radially outer side than the inner peripheral side portion, and the inner peripheral side portion. And a plurality of arm portions that are elastically deformed by connecting the outer peripheral side portions.

  The outer peripheral side portion of the upper spring 9 is fixed between the frame 4 and the yoke 5 in the illustrated embodiment.

  The lower spring 10 is divided into two, and each divided body is an inner peripheral side portion fixed to the lower side of the lens carrier 7 which is a moving body, and a fixed body on a radially outer side than the inner peripheral side portion. An outer peripheral side portion to be fixed and an arm portion that is elastically deformed by connecting the inner peripheral side portion and the outer peripheral side portion are provided.

  The outer peripheral side portion of the lower spring 10 is fixed to the base 2 in the illustrated embodiment.

  The inner peripheral side portion of the upper spring 9 and the inner peripheral side portion of the lower spring 10 are fixed to the lens carrier 7 above and below the lens carrier 7, respectively, and the lens carrier 7 is supported so as to be movable in the optical axis direction. Yes.

  The outer peripheral side portions of the divided body of the lower spring 10 are electrically connected to terminals (not shown), respectively. A current is supplied to the coil 8 from the terminal (not shown) via the outer peripheral side portion of the lower spring 10.

  Before the current is supplied to the coil 8, the contact portion 19 of the lens carrier 7 is in contact with the contacted portion 23 of the base 2. In this state, the upper spring 9 and the lower spring 10 urge the lens carrier 7 toward the base 2.

  As shown in FIG. 2, when a current is supplied to the coil 8, a thrust (electromagnetic force) is generated by the magnetic flux of the magnet 6, and the lens carrier 7 and a lens (not shown) supported by the lens carrier 7 move in the optical axis direction. To do. The lens moves to a position where the restoring force and thrust (electromagnetic force) of the upper spring 9 and the lower spring 10 are balanced, and a focusing operation and the like are performed.

  Next, a dustproof structure in the lens driving device 1 of the present embodiment will be described.

  As shown in FIG. 1, the lens driving device 1 of the present embodiment is formed between a peripheral portion outside the radial direction of the through hole 3 of the base 2 that is a fixed body and a lens carrier 7 that is a moving body. The sealing member 13 which closes the gap 22 is provided. The sealing member 13 closes the gap 22 over the entire circumference of the through hole 3. The sealing member 13 expands and contracts following the movement of the lens carrier 7 in the optical axis direction described above.

  The gap 22 formed between the lens carrier 7 and the base 2 is closed over the entire circumference of the through hole 3 by the sealing member 13. The sealing member 13 expands and contracts following the movement of the lens carrier 7 in the optical axis direction, so that the gap 22 is blocked over the entire circumference of the through hole 3 even if the lens carrier 7 moves in the optical axis direction. to continue. Accordingly, even if the lens carrier 7 moves in the optical axis direction, dust and dust can be prevented from entering from the outside of the sealing member 13 to the inside of the sealing member 13 having the through hole 3. A structure is built. Therefore, it is possible to prevent foreign matter from entering the through hole 3 when the lens (not shown) moves. Accordingly, when the lens driving device 1 is incorporated as a camera module together with the IR filter 12 and the image sensor 11, it is possible to prevent foreign matter from adhering to the IR filter 12 and the imaging performance of the image sensor 11 from being deteriorated.

  The sealing member 13 is a member that expands and contracts following the movement of the lens carrier 7 along the optical axis direction of the lens. As such a member, a liquid material, a semi-solid or semi-fluid lubricant at room temperature, or an amorphous and soft polymer substance can be used. Examples of the liquid material include lubricating oil and magnetic fluid. Examples of the lubricant having semi-solid or semi-fluidity at normal temperature include grease. Examples of the amorphous and soft polymer material include natural rubber and synthetic rubber.

  Next, a structure for preventing the sealing member 13 from expanding beyond a predetermined region will be described. A region where the sealing member 13 contacts in the base 2 and the lens carrier 7 is referred to as a contact region 14. Further, in the base 2 and the lens carrier 7, a region adjacent to the contact region 14 and not in contact with the sealing member 13 is defined as a non-contact region 15.

  In this embodiment, the non-contact region 15 in the base 2 can have a structure that is less lyophilic with respect to the contact region 14 in the base 2. In addition, the non-contact area 15 in the lens carrier 7 can have a structure that is less lyophilic with respect to the contact area 14 in the lens carrier 7. The lyophilic property is a property representing the affinity between the surface of the substance and the liquid, and particularly when the liquid is water, it is called hydrophilic.

  Since the non-contact region 15 is less lyophilic than the contact region 14, the sealing member 13 is less likely to move beyond the contact region 14 to the non-contact region 15. Therefore, it is desirable to have such a structure in order to prevent the sealing member 13 from protruding from the contact region 14 and spreading to the non-contact region 15.

  Note that either the base 2 or the lens carrier 7 may have such a structure, and both the base 2 and the lens carrier 7 have such a structure. You can also.

  In the above description, the lyophilicity can be expressed by the wettability of the sealing member 13 with respect to the surfaces of the base 2 and the lens carrier 7 with which the sealing member 13 contacts and the surface roughness of the surfaces of the base 2 and the lens carrier 7. .

  When wettability indicates lyophilicity, high and low lyophilicity means high and low wettability (small and large contact angle). In this case, the non-contact area 15 has low wettability with respect to the contact area 14. Therefore, the sealing member 13 wets and spreads in the contact area 14 but is not easily wetted in the non-contact area 15, so that the sealing member 13 does not protrude from the contact area 14 and hardly spread to the non-contact area 15. For example, a thin film can be formed with a material having high wettability on the surface of the contact region 14, or a thin film can be formed with a material having low wettability on the surface of the non-contact region 15.

  When the surface roughness represents lyophilicity, high and low lyophilicity means that the surface roughness is large or small. In this case, the non-contact area 15 has a smaller surface roughness than the contact area 14. That is, since the contact region 14 has large (rough) fine irregularities on the surface thereof, the surface area on which the sealing member 13 is held is large, and the sealing member 13 is easily held. However, the non-contact region 15 has small surface irregularities (smooth), so that the surface area on which the sealing member 13 is held is small, and the sealing member 13 is hardly held. Therefore, the sealing member 13 hardly protrudes from the contact region 14 and spreads to the non-contact region 15. For example, the surface of the contact region 14 can be roughened, or the surface of the non-contact region 15 can be smoothed.

  In this embodiment, the contact area 14 in the base 2 that is a fixed body is provided on the upper side 20 of the base 2. Further, the contact region 14 in the lens carrier 7 that is a moving body is provided on the lower side 21 of the lens carrier 7. The two contact areas 14 and 14 are opposed to each other in the optical axis direction. Since it has a simple structure, it can be manufactured at low cost.

  In this embodiment, the contact area 14 in the base 2 and the contact area 14 in the lens carrier 7 can be configured not to contact each other. If contact occurs while the lens carrier 7 moves in the optical axis direction, the sealing member 13 flows from the contact region 14 to the non-contact region 15, the sealing member 13 scatters, or the sealing member 13. There is a risk of entrapment of air bubbles inside. In order to prevent this, it is advantageous that the contact area 14 in the base 2 and the contact area 14 in the lens carrier 7 do not contact each other.

  In this embodiment, as described above, the lens carrier 7 has the contact portion 19 protruding downward from the lower surface thereof. The contact portion 19 contacts the contacted portion 23 of the base 2. For this reason, the contact area 14 in the base 2 and the contact area 14 in the lens carrier 7 do not contact each other.

  Further, all the contacted portions 23 are provided outside the contact area 14 in the base 2. For this reason, all foreign matters generated when the contact portion 19 contacts the contacted portion 23 are generated outside the sealing member 13. Therefore, it is possible to prevent foreign matter generated by this contact from entering the through hole 3.

  In the present embodiment, the contact portion 19 protrudes, but either may protrude. It is good also as a structure that the to-be-contacted part 23 protrudes. For example, the contacted portion 23 may be concave.

  As described above, the lens driving device 1 of this embodiment has the gap 22 formed between the lower side 21 of the lens carrier 7 and the upper side 20 of the peripheral portion outside the through hole 3 of the base 2. A dustproof structure is provided in which the sealing member 13 is closed over the entire circumference of the through hole 3. This dustproof structure constituted by the sealing member 13 expands and contracts following the movement of the lens carrier 7 in the optical axis direction, and flexibly changes its shape when the lens driving device 1 is driven. Therefore, entry of foreign matter such as dust and dirt into the gap 22 can be prevented.

  Various forms can be exemplified as the dust-proof structure in this embodiment.

  In the embodiment shown in FIGS. 1 and 2, the contact region 14 that contacts the sealing member 13 in the base 2 and the contact region 14 that contacts the sealing member 13 in the lens carrier 7 face each other in the optical axis direction. Yes.

  On the other hand, in the embodiment shown in FIGS. 3 and 4, the contact region 14 that contacts the sealing member 13 in the base 2 that is a fixed body and the contact that contacts the sealing member 13 in the lens carrier 7 that is a moving body. The region 14 is opposed to each other in a direction perpendicular to the optical axis. Also in this structure, the gap 22 formed between the lower side 21 of the lens carrier 7 and the upper side 20 of the peripheral portion outside the through hole 3 of the base 2 is sealed over the entire circumference of the through hole 3. 13 is plugged.

  In the case of this embodiment, the contact region 14 of the base 2 and the contact region 14 of the lens carrier 7 are opposed to each other in a direction orthogonal to the optical axis. Does not touch.

  In the embodiment shown in FIGS. 5 and 6, the lens carrier 7 has a convex portion 17 protruding downward on its lower side, and the base 2 has a concave portion 18 on its upper side. The concave portion 18 accommodates the convex portion 17. The sealing member 13 is disposed inside the recess 18. Also in this structure, the sealing member 13 covers the entire circumference of the through hole 3 in the gap 22 formed between the lower side 21 of the lens carrier 7 and the upper side 20 of the base 2. Since the sealing member 13 is disposed inside the recess 18, it is difficult for the sealing member 13 to protrude beyond the recess 18 beyond the recess 18. Moreover, since many sealing members 13 can be stored, even if time passes, the sealing members 13 are hard to lose.

  5 and 6, the lens carrier 7 has a convex portion 17 and the base 2 has a concave portion 18. Instead, the base 2 has a convex portion, and the lens carrier 7 has a convex portion. However, it is also possible to provide a structure in which a concave portion for accommodating the convex portion is provided, and the sealing member 13 is disposed inside the concave portion.

  In the embodiment shown in FIGS. 7 and 8, a magnetic fluid is employed as the sealing member 13. A magnet 16 for adsorbing magnetic fluid is disposed in a contact region 14 in the base 2 where the sealing member 13 made of magnetic fluid contacts. In the illustrated embodiment, an annular step portion 20a is formed on the upper side 20 of the base 2, and an annular magnet 16 is disposed on the step portion 20a. The magnetic fluid is a liquid in which minute magnetic powder is dispersed. Since the magnetic powder is attracted to the magnet 16, it is difficult for the magnetic fluid to diffuse to a region other than the magnet 16. Therefore, the sealing member 13 expands and contracts following the movement of the lens carrier 7 along the optical axis direction of the lens, and a gap formed between the lower side 21 of the lens carrier 7 and the upper side 20 of the base 2. This is advantageous in maintaining the state in which the sealing member 13 closes the entire circumference of the through hole 3.

  In the illustrated embodiment, a magnet is not employed in the contact region 14 of the lens carrier 7 so that the sealing member 13 described with reference to FIGS. 1 and 2 does not extend beyond a predetermined region. Adopt a structure for.

  The structure in which the magnet 16 for attracting the magnetic fluid is disposed in the contact region 14 in contact with the sealing member 13 made of the magnetic fluid is not limited to the illustrated embodiment. It is also possible to adopt a structure in which a magnet 16 for attracting magnetic fluid is arranged in a contact region 14 where the sealing member 13 made of magnetic fluid contacts in the lens carrier 7, and in the base 2 and the lens carrier 7, magnetic fluid can be used. It is also possible to employ a structure in which a magnet 16 for attracting a magnetic fluid is provided in each contact region 14 in contact with the sealing member 13 made of the material.

  In any of the embodiments shown in FIGS. 3 and 4 and the embodiments shown in FIGS. 5 and 6, the sealing member 13 is a magnetic fluid, and the sealing member 13 is provided in one or both of the base 2 and the lens carrier 7. It is also possible to employ a structure in which a magnet 16 for attracting magnetic fluid is provided in the contact region 14 that comes into contact.

  The lens driving device 1 according to the present embodiment has a structure including the sealing member 13 over the entire circumference of the through hole 3. However, for example, when there is a structure having another dustproof function in a part of the peripheral part outside the through hole 3, and the sealing member 13 cannot be provided in the structure part, the entire circumference is called Needless to say, this is a part excluding the structural part.

  The lens driving device 1 of the present embodiment has a configuration in which the lens carrier 7 is urged by the base 2 in an initial state where no current flows through the coil 8. However, the lens carrier 7 may be separated from the base 2 in this initial state.

  In addition, the lens driving device 1 of the present embodiment has a configuration in which the magnet carrier 6 and the coil 8 are used as driving sources, and the lens carrier 7 is supported by the upper spring 9 and the lower spring 10. However, the present invention is not limited to this, and a configuration in which the movement of the lens carrier 7 is guided by a ball may be used. Also, the drive source may be a piezoelectric element or a stepping motor.

[Embodiments of Camera Device and Electronic Device]
According to the lens driving device 1 of the above-described embodiment, when the lens carrier 7 moves along the optical axis direction, the sealing member 13 expands and contracts in the optical axis direction following the movement. Therefore, the sealing member 13 can continue to block the gap 22 formed between the lower side 21 of the lens carrier 7 and the upper side 20 of the base 2 over the entire circumference of the through hole 3. Therefore, it is possible to prevent foreign matter from entering the through hole 3 when the lens (not shown) moves.

  The lens driving device 1 is assembled as a camera module together with a lens (not shown), an IR filter 12, and a substrate 24 to which the image sensor 11 is attached. The camera module is incorporated in a camera device or an electronic device.

  Therefore, the camera device and the electronic apparatus in which the lens driving device 1 according to the above-described embodiment is employed can prevent foreign matters such as dust and dust from entering the through-hole 3, so that foreign matters such as dust and dust can be prevented. It is possible to prevent the imaging performance of the image sensor 11 from being attached to the IR filter 12 from being deteriorated.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to such embodiments, and various forms are possible within the technical scope grasped from the description of the claims. Can be changed.

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Base 3 Through-hole 4 Frame 5 Yoke 6 Magnet 7 Lens carrier 7a Lens holding part 8 Coil 9 Upper spring 10 Lower spring 11 Imaging element 12 IR filter 13 Sealing member 14 Contact area 15 Non-contact area 16 Magnet 17 Convex part 18 Concave part 19 Abutting part 20 Upper side 20a of the base Step part 21 Lower side of the lens carrier 22 Gap 23 Abutted part 24 Substrate

Claims (14)

A fixed body having a through-hole through which light transmitted through the lens passes;
A movable body having a lens holding portion for holding the lens and capable of moving along the optical axis direction of the lens;
A sealing member capable of closing a gap formed between a peripheral portion outside the through-hole and the movable body over the entire circumference of the through-hole and expanding and contracting following the movement of the movable body; A lens driving device.   The lens driving device according to claim 1, wherein the sealing member is a liquid material.   The non-contact area | region which adjoins the said contact area with respect to the contact area which the said sealing member contacts in at least one of the said fixed body or the said moving body, and the said sealing member does not contact has low lyophilicity. Lens drive device.   The lens driving device according to claim 3, wherein the lyophilic property is wettability, and the non-contact region has low wettability with respect to the contact region.   The lens driving device according to claim 3, wherein the lyophilicity is surface roughness, and the non-contact area has a smaller surface roughness than the contact area.   The lens driving device according to claim 2, wherein the liquid is a magnetic fluid, and a magnet is disposed in a contact area where the magnetic fluid is in contact with at least one of the fixed body and the moving body.   The lens driving device according to claim 1, wherein the sealing member is formed of an amorphous and soft polymer material.   The contact area where the sealing member contacts in the fixed body and the contact area where the sealing member contacts in the movable body face each other in the optical axis direction. The lens driving device described.   The contact area where the sealing member contacts in the fixed body and the contact area where the sealing member contacts in the movable body face each other in a direction perpendicular to the optical axis. The lens driving device according to one item.   One of the fixed body or the movable body has a convex portion, the other of the fixed body or the movable body has a concave portion that accommodates the convex portion, and the sealing member is disposed inside the concave portion. The lens driving device according to claim 1.   The lens driving device according to claim 1, wherein a contact area where the sealing member contacts the fixed body and a contact area where the sealing member contacts the movable body do not contact each other.   The fixed body has a contacted portion with which the contact portion of the movable body contacts in the optical axis direction, and the contacted portions are all outside the contact area where the sealing member contacts with the fixed body. The lens driving device according to claim 1, wherein the lens driving device is provided.   A camera device comprising the lens driving device according to claim 1.   The electronic device provided with the lens drive device as described in any one of Claims 1 thru | or 12.

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