JP2009150922A - Actuators, imaging devices and portable electronic devices - Google Patents

Abstract

An actuator capable of surely limiting a moving range of a holder is provided.
An actuator includes a holder that holds a lens, and a support that includes an upper guide and a base that supports the holder. The upper guide 3 and the base portion 9 support the holder 8 so as to be movable in the optical axis direction of the lens 13. When the holder 8 moves in the optical axis direction or the rotation direction, the contact portion 80 formed on the holder 8 contacts the restriction portion 30 formed on the upper guide 3 or the contact portion 81 formed on the holder 8. Is in contact with the restricting portion 90 formed on the base portion 9, the movement range of the holder 8 in the optical axis direction and the rotational direction is limited.
[Selection] Figure 4

Description

  The present invention relates to an actuator, and an imaging device and a portable electronic device including the same, and more specifically, an actuator that performs focusing or zooming by driving a lens, and an imaging device and a portable electronic device including the actuator. It relates to equipment.

  In recent years, in order to improve the image quality of a camera (imaging device) built in a portable electronic device, the number of pixels of an image sensor mounted on the camera is increasing. In many cases, a camera built in a portable electronic device is provided with an autofocus mechanism or an autozoom mechanism necessary for improving the image quality of a captured image. Such a mechanism usually performs focusing or zooming by moving an optical system in the camera in the optical axis direction. Therefore, the holder that holds the optical system is configured to be movable in the optical axis direction of the optical system. As described above, as a method of configuring the holder that holds the optical system to be movable in the optical axis direction, a method of attaching a pair of leaf springs in parallel to both ends of the holder in the optical axis direction and supporting the holder by the leaf springs. Is mentioned.

  Furthermore, an actuator is required to move the holder supported as described above. As an actuator for driving a holder for holding an optical system, a voice coil type actuator is widely used. In a voice coil type actuator, a holder is driven by generating a thrust by an electromagnetic induction phenomenon using a magnetic circuit including a coil and a magnet.

  In such a voice coil type actuator, when a thrust is applied to drive a holder supported by a pair of leaf springs, the pair of leaf springs arranged in parallel are deformed at both ends in the optical axis direction of the holder. As a result, the holder is displaced in the optical axis direction. Such a conventional actuator will be described using the autofocus actuator disclosed in Patent Document 1 as an example.

  The autofocus actuator described in Patent Document 1 will be described with reference to FIG. FIG. 9 is a cross-sectional view showing a conventional autofocus actuator 100. The actuator 100 is used as an autofocus mechanism of a camera built in a general portable electronic device. As shown in FIG. 9, a conventional actuator 100 includes a cylindrical permanent magnet (magnet) 101, a yoke 102 formed in a U-shape, a coil 103, and a lens unit (optical system) 104. A holder 105 and a pair of leaf springs 106a and 106b are provided. The arrows shown in FIG. 9 indicate the optical axis direction of the lens attached to the lens unit 104.

  The magnet 101 is provided so as to be sandwiched between yokes 102 formed in a U-shape, and the coil 103 formed on the flange portion of the holder 105 is provided so as to be sandwiched between the yokes 102. And the magnet 101. A pair of leaf springs 106a and 106b are provided at both ends of the holder 105 in the optical axis direction so as to face each other in parallel. The holder 105 is supported by the leaf springs 106a and 106b in a state of being positioned in a direction orthogonal to the optical axis direction. In the actuator 100, when a current is applied to the coil 103, a thrust acts on the holder 105 due to an electromagnetic induction phenomenon between the magnet 101 and the coil 103, and the plate springs 106 a and 106 b are deformed in the optical axis direction. Move in the direction of the optical axis.

The optical system 104 supported by the holder 105 may be displaced so that the optical axis of the optical system deviates from the center axis of the image sensor due to an external force applied to the apparatus. When the tilt of the optical system 104 with respect to the image sensor (shift of the optical axis of the optical system with respect to the center of the image sensor) increases, the image to be captured decreases. Therefore, in order to prevent the optical axis of the optical system 104 from deviating, it is necessary to limit displacement in directions other than the optical axis direction, such as the direction in which the holder 105 rotates. Further, in order to prevent contact between the components in the actuator 100, it is necessary to limit the movement range of the holder 105 such as the optical axis direction and the rotation direction. In the actuator 100, the leaf springs 106a and 106b fix the holder 105 so as to be movable in the optical axis direction, and limit the movement range of the holder 105 in the optical axis direction and the rotation direction.
JP 2006-50693 A (published February 16, 2006)

  However, when the movement range of the holder 105 in the optical axis direction and the rotation direction is limited by a spring as in the conventional actuator 100 described above, the movement range of the holder 105 is sufficiently limited due to a decrease in the strength of the spring. There is a problem that it becomes impossible to do.

  In particular, in recent years, in order to further reduce the size or thickness of a camera for a portable electronic device, there is an increasing demand for the size reduction or thickness reduction of an actuator provided in the camera. It is necessary to make the width and thickness of the spring as small as possible. Such reduction in the width and thickness of the spring further reduces the strength of the spring and easily loses the plasticity of the spring, so that the holder 105 cannot be sufficiently supported. As a result, the moving direction and moving range of the holder 105 cannot be sufficiently limited.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an actuator that can limit the moving range of the holder in the optical axis direction of the lens and the rotation direction around the optical axis of the lens, and An object of the present invention is to provide an imaging device and a portable electronic device provided with this.

  In order to solve the above problems, an actuator according to the present invention includes a holder that holds a lens, a support that supports the holder so as to be movable in the optical axis direction of the lens, and the holder and the support portion. And a rotating member that is rotatably disposed between the holder and supports the movement of the holder, and the support is configured so that the holder has an optical axis direction of the lens and a rotation direction around the optical axis of the lens. The holder has a restricting portion that restricts the moving range, and the holder has a contact portion that contacts the restricting portion when the restricting portion restricts the moving range.

  In the above configuration, a rotating member is disposed between the holder and the support so that the holder can move in the optical axis direction of the lens. When the rotating member rotates between the holder and the support, a frictional force is generated between the rotating member and the holder. The rotating member supports the movement of the holder in the optical axis direction of the lens by this frictional force. Unlike springs, etc., the rotating member does not deform even when it is reduced in size and thickness, and it can support the holder sufficiently, and the actuator can be reduced in size and thickness without reducing impact resistance. can do.

  The support has a restricting portion that restricts the movement range of the holder in the optical axis direction and the rotation direction, and the holder has a contact portion that comes into contact with the restricting portion when the movement range is restricted by the restricting portion. is doing. Thereby, when the holder moves in the optical axis direction of the lens, the moving range of the holder in the optical axis direction of the lens can be limited by the contact portion of the holder coming into contact with the regulating portion of the support. Further, for example, when an external force is applied to the holder and the holder is displaced in the direction of rotation about the optical axis of the lens, the holder abutment portion abuts on the support restricting portion, whereby the holder moves in the rotation direction. The range can be limited. In this way, the movement range of the holder is more reliably limited, so that the position of the holder can be prevented from being displaced by an external force applied to the actuator, and the components can be prevented from coming into contact with each other. Can be provided.

  In the actuator according to the present invention, a plurality of the rotating members are respectively disposed on both end sides of the holder in the optical axis direction of the lens, and the rotating members disposed on one end side of the holder It is preferable that the rotating member disposed on the other end side of the holder is disposed at a position facing the rotating member along a line parallel to the optical axis of the lens. Thereby, the holder can be accurately supported without being biased in a certain direction, and the movement of the holder in the optical axis direction can be more accurately supported.

  In the actuator according to the present invention, it is preferable that the rotating member has a substantially spherical shape or a cylindrical shape. Thereby, the holder can be supported so that the movement of the holder in the optical axis direction of the lens is performed smoothly.

  In the actuator according to the present invention, the holder has a plurality of contact portions at substantially equal intervals at an end portion in a direction orthogonal to the optical axis of the lens, and the support body includes the contact portions. It is preferable that the same number of the restricting portions as the contact portions are provided at positions corresponding to. Thereby, the movement range of the holder in the optical axis direction of the lens and the movement range of the rotation direction of the holder can be more reliably limited.

  In the actuator according to the present invention, the support includes a first support portion that supports one end of the holder in the optical axis direction of the lens, and a second support that supports the other end of the holder in the optical axis direction of the lens. It is preferable to have a support part. Thus, when forming the support body in a configuration that supports the holder so that it can move, it is not necessary to form the support body as a single member, and by combining two support portions having a simpler shape, A support can be formed. As a result, the support can be easily molded, so that the molding accuracy of the parts can be increased. Furthermore, the accommodation range of the holder in the support body can be easily expanded, and the restriction on the shape of the holder disposed inside the support body is reduced.

  In the actuator according to the present invention, the restricting portion includes a first restricting portion formed on the first support portion and a second restricting portion formed on the second support portion, and the contact portion. The portion is formed on one end side of the holder in the optical axis direction of the lens, and is formed on the first contact portion corresponding to the first restricting portion and the other end side of the holder in the optical axis direction of the lens. And a second contact portion corresponding to the second restricting portion. Thereby, the movement range of the holder in the optical axis direction of the lens and the movement range of the rotation direction of the holder can be more reliably limited.

  In the actuator according to the present invention, the first contact portion includes a first axial contact surface orthogonal to the optical axis direction of the lens and a first rotational contact that is parallel to the optical axis direction of the lens. A second abutting portion perpendicular to the optical axis direction of the lens and a second rotational direction parallel to the optical axis direction of the lens. The first restricting portion includes a first axial restricting surface that faces the first axial contact surface, and a first rotational surface that faces the first rotational contact surface. The second restricting portion includes a second axial restricting surface facing the second axial contact surface and a second rotational facing surface facing the second rotational contact surface. It is preferable to have 2 rotation direction control surfaces. Thereby, the movement range of the holder in the optical axis direction of the lens and the movement range of the rotation direction of the holder can be more reliably limited.

  In the actuator according to the present invention, at least one of the first rotation direction contact surface, the second rotation direction contact surface, the first rotation direction restriction surface, and the second rotation direction restriction surface is a lens light. The length in the axial direction is preferably longer than the moving range of the holder in the optical axis direction of the lens. As a result, even when the holder is moving in the optical axis direction of the lens, the rotation direction contact surface of the holder and the rotation direction regulating surface of the support body are opposed to each other. It is possible to more reliably limit the movement range in the rotation direction.

  In the actuator according to the present invention, when the holder moves in the optical axis direction of the lens, the first rotation direction contact surface is not in contact with the first rotation direction regulating surface, and the second rotation direction contact surface is not. It is preferable that the contact surface is not in contact with the second rotation direction regulating surface. Thereby, when the holder moves in the optical axis direction of the lens, the holder and the support are prevented from coming into contact with each other, and the holder can be moved stably.

  In the actuator according to the present invention, one of the first contact portion and the first restricting portion has a concave shape, and the other has a convex shape that fits into the concave shape, and the second contact portion and It is preferable that either one of the second restricting portions has a concave shape and the other has a convex shape that fits into the concave shape. Thereby, since the contact part of a holder and the control part of a support body can be made into a simpler structure, a manufacturing process can be simplified.

  An imaging apparatus according to the present invention includes any one of the actuators described above. In addition, a portable electronic device according to the present invention includes the above-described imaging device. Thereby, there exists an effect similar to the said actuator.

  In the actuator according to the present invention, as described above, the support that supports the holder holding the lens so as to be movable in the optical axis direction of the lens has a restricting portion that limits the movement range of the holder, Since the contact portion is restricted by the restriction portion, it is possible to limit the movement range of the holder in the optical axis direction and the rotation direction.

  The actuator which concerns on one Embodiment of this invention is demonstrated below based on FIGS. In the following description, the same members and components are denoted by the same reference numerals, and since these functions are the same, detailed description will not be repeated. FIG. 1 is a perspective view showing an imaging device 21 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the imaging device 21 according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the imaging device 21 according to an embodiment of the present invention.

(Imaging equipment 21)
As shown in FIGS. 1 and 2, the imaging device 21 includes an upper cover 1 that covers the top of the imaging device 21, a spherical body (rotating member) 2, an upper guide (first support) 3, a leaf spring 4, and a yoke 5. , A magnet 6, a coil 7, a holder 8, a base part (second support) 9, a lower cover 10, an image sensor 11, a sensor substrate 12, a lens 13, and a barrel 14.

  In the present specification, the term “optical axis direction” refers to light from a subject incident on the lens 13 and parallel to the central axis of the light, that is, an optical member in the imaging device 21 and the subject. It is intended to be parallel to the line connecting the two. The term “object side” is intended to be the side closest to the subject in the imaging device 21, and the term “image plane side” is intended to be the opposite side of the object side in the imaging device 21. The arrows shown in FIG. 1 indicate the directions on the object side and the image plane side.

  In the imaging device 21, when light from a subject enters the lens 13 from the object side, the light is imaged on the imaging element 11 by the lens 13. An image of the subject is formed by converting the light imaged in the image sensor 11 into an electrical signal.

  As shown in FIGS. 2 and 3, in the imaging device 21, the barrel that holds the lens 13 is held by the holder 8. The object side of the holder 8 is supported by the upper guide 3, and the image plane side of the holder 8 is supported by the base portion 9. A plurality of spherical bodies 2 are provided between the holder 8 and the upper guide 3 and between the holder 8 and the base portion 9, respectively. Further, the object side surface of the holder 8 is fixed by a leaf spring 4 provided between the holder 8 and the upper guide 3.

(Actuator 22)
As shown in FIG. 3, the actuator 22 included in the imaging device 21 includes, in order from the object side, the upper cover 1, the spherical body 2, the upper guide 3, the leaf spring 4, the yoke 5, the magnet 6, the coil 7, the holder 8, and the base. It is comprised by the part 9, the spherical body 2, and the lower cover 10. FIG. Then, the sensor substrate 12 on which the image pickup device 11 is formed is fixed to the actuator 22 on the image plane side of the base portion 9 via the lower cover 10, and the lens 13 is held in the space in the holder 8 from the object side. 1 is assembled by inserting the barrel 14 to be assembled. When the barrel 14 is inserted into the holder 8, it is positioned so that the center of the optical axis of the lens 13 and the center of the image sensor 11 are substantially coincident.

  The actuator according to the present embodiment is 22, for example, in an imaging device 21 mounted on a portable electronic device such as a cellular phone, by moving the holder 8 including the lens 13 in the optical axis direction using an electromagnetic induction phenomenon. Auto focusing or auto zooming is performed.

  As shown in FIG. 3, the yoke 5, which is a magnetic body, has a cylindrical shape and is provided so as to surround the periphery of the holder 8. The yoke 5 is disposed so as to be sandwiched between the upper cover 1 and the upper guide 3 on the object side, and the lower cover 10 and the base portion 9 on the image plane side. A magnet 6 obtained by dividing a cylindrical magnet into a plurality of plates is attached to the inner wall of the yoke 5. A holder 8 is disposed inside a space formed by the yoke 5, the upper cover 1, the upper guide 3, the base portion 9, the magnet 6 and the lower cover 10.

  A coil 7 is wound around the side surface of the holder 8, and a gap exists between the coil 7 and the magnet 6. Each of the plurality of spherical bodies 2 provided on both the object side and the image plane side of the actuator 22 is located between the holder 8 and the upper guide 3 or between the holder 8 and the base portion 9. The spherical body 2 on the object side is in contact with the holder 8 and the upper guide 3, respectively, and the spherical body 2 on the image plane side is in contact with the holder 8 and the base portion 9, respectively.

  The actuator 22 includes a magnetic circuit including a yoke 5, a magnet 6, and a coil 7. When a current is applied to the coil 7, an electromagnetic induction phenomenon occurs between the magnet 6 and the coil 7. By this electromagnetic induction phenomenon, thrust in the optical axis direction is applied to the holder 8 around which the coil 7 is wound. By this thrust, the holder 8 moves along the optical axis direction. The thrust applied to the holder 8 is proportional to the amount of current applied to the coil 7, and the direction of the thrust applied to the holder 8 is determined by the direction of the current applied to the coil 7.

(Upper cover 1 and lower cover 10)
In the actuator 22, the upper cover 1 provided on the upper part of the upper guide 3 prevents the spherical body 2 from dropping off from the actuator before the sensor substrate 12 is fixed, and dust from entering the actuator 22. In addition, the lower cover 10 formed at the lower part of the base portion 9 prevents the spherical body 2 from falling off and dust from entering the image sensor 11 after the sensor substrate 12 is fixed.

(Leaf spring 4)
In the actuator 22, the leaf spring 4 is disposed on the object side of the holder 8. The leaf spring 4 is supported and fixed by the upper guide 3 and is in contact with the object-side surface of the holder 8 that moves in the optical axis direction. The leaf spring 4 gives the holder 8 a preload proportional to the amount of movement (displacement) of the holder 8 in the optical axis direction. That is, the leaf spring 4 generates an elastic force proportional to the amount of movement of the holder 8 that moves in the optical axis direction. In the actuator 22, the holder 8 is held by the balance between the thrust acting on the holder 8 and the elastic force generated in the leaf spring 4. Therefore, the position of the holder 8 is affected by the amount of current applied to the coil 7. The relationship between the position of the holder 8 and the amount of current applied to the coil 7 is the same as that of the conventional actuator.

  Here, for example, as the holder 8 moves to the object side along the optical axis direction, the contact portion between the holder 8 and the leaf spring 4 may vary. In other words, the contact portion between the leaf spring 4 and the holder 8 moving in the optical axis direction may slide sideways. In this case, compared to a configuration in which the holder 8 is fixed to the leaf spring 4, even if the holder 8 vibrates due to an external force applied to the actuator, for example, plastic deformation of the leaf spring 4 can be suppressed.

(Upper guide 3 and base portion 9)
The upper guide 3 and the base portion 9 support the holder 8. In the present embodiment, the upper guide 3 and the base portion 9 are provided as separate members, but the upper guide 3 and the base portion 9 may be integrally formed so as to support the holder 8 as a single support. Good. The upper cover 1, the upper guide 3, and the base portion 9 are provided so as to sandwich the magnet 6 and the yoke 5 from the optical axis direction. Each of the upper guide 3 and the base portion 9 is formed in a ring shape so as to have a gap for inserting the holder 8. A yoke 5 is disposed on the object side of the base portion 9, and a sensor substrate 12 on which an image sensor 11 is formed is disposed on the image plane side of the base portion 9. The upper guide 3 is disposed on the yoke 5 and is fixed by being sandwiched between the yoke 5 and the upper cover 1.

(Spherical body 2)
The plurality of spherical bodies 2 located between the holder 8 and the upper guide 3 and between the holder 8 and the base portion 9 are located between the side surfaces of the holder 8 when the holder 8 is moved in the optical axis direction. It is configured to rotate by the generated frictional force. In the actuator 22, the frictional force generated by the rotation of the spherical body 2 supports the movement of the holder 8 in the optical axis direction, thereby stabilizing the movement of the holder 8. Further, since the holder 8 is in contact with the spherical body 2, displacement in a direction other than the optical axis direction such as a direction perpendicular to the optical axis direction of the holder 8 is limited.

  Thus, in the actuator 22 according to the present invention, it is not necessary to use a pair of leaf springs to fix the holder as in the conventional actuator. Therefore, unlike the conventional actuator, there is no problem that the holder 8 cannot be sufficiently fixed and held due to a decrease in the strength of the leaf spring. For example, in the conventional actuator, if the volume of the magnetic circuit is reduced in order to reduce the size and thickness of the actuator, it is necessary to reduce the spring constant of the leaf spring. However, when the spring constant of the leaf spring is reduced, the strength of the spring is lowered and the impact resistance is lowered. That is, the plasticity of the spring is easily lost, and the holder 8 cannot be held sufficiently, so that the moving direction and the displacement amount of the holder 8 cannot be limited. As a result, the tilt of the optical system with respect to the image sensor (shift of the optical axis of the optical system with respect to the center of the image sensor) increases, leading to a decrease in image quality.

  On the other hand, in the actuator 22 according to the present invention, since the holder 8 is supported by the plurality of spherical bodies 2, it is not necessary to use a leaf spring to support or fix the holder 8. Unlike the spring, the spherical body 2 is not deformed even if it is reduced in size and thickness, can hold the holder 8 sufficiently, and an actuator 22 having excellent impact resistance can be realized.

  In the present embodiment, one leaf spring 4 is provided on the object side of the holder 8. Alternatively, the leaf spring 4 may be further used for the purpose of assisting the spherical body 2. That is, the holder 8 may be fixed and supported by the leaf spring 4. In the conventional actuator, two leaf springs are required to fix and support the holder 8. On the other hand, in the actuator 22 according to the present invention, since the spherical body 2 is used to support the movement of the holder 8 in the optical axis direction, only one leaf spring 4 for fixing and supporting the holder 8 is required. Therefore, even if the plate springs 4 are formed so as to have the same spring constant as that of the conventional plate springs, the strength of the plate springs 4 per unit increases compared to the conventional actuator. Therefore, for example, the resistance of the leaf spring 4 when the imaging device 21 for portable electronic devices is dropped can be increased.

  Furthermore, in the conventional actuator, only the movement of the holder in the optical axis direction is supported by the leaf spring. In other words, the conventional actuator cannot suppress (limit) the displacement of the holder in a direction other than the optical axis direction. On the other hand, in the actuator 22 according to the present invention, the spherical body 2 suppresses (limits) the displacement of the holder 8 in a direction other than the optical axis direction. Therefore, in the actuator 22, the holder 8 hardly vibrates in directions other than the optical axis direction due to, for example, an impact generated when the actuator 22 is dropped.

  In the actuator 22, the movement of the holder 8 in the optical axis direction is supported by the frictional force generated between the spherical body 2 and the holder 8, and the displacement of the holder 8 in a direction other than the optical axis direction is suppressed. . Therefore, the actuator 22 is not particularly limited as long as the spherical body 2 is in contact with the holder 8 as long as the effects described above are obtained.

  Here, the upper guide 3 and the base portion 9 support the holder 8 via the spherical body 2, and the holder 8, the upper guide 3 and the base portion 9 are not in contact with each other. When the holder 8 is in contact with the upper guide 3 and the base 9, an unnecessary frictional force is generated between the holder 8, the upper guide 3 and the base portion 9 when the holder 8 is moved in the optical axis direction. The smooth movement of the holder 8 in the optical axis direction is hindered. From this viewpoint, the spherical body 2 functions as a guide that smoothly moves the holder 8 in the optical axis direction between the holder 8, the upper guide 3, and the base portion 9.

  The number of the spherical bodies 2 arranged between the holder 8 and the upper guide 3 and the number of the spherical bodies 2 arranged between the holder 8 and the base portion 9 are applied to the volume of the magnetic circuit portion and the magnetic circuit. It can be set as appropriate according to the amount of current to be applied. As the number of the spherical bodies 2, for example, a plurality of the spherical bodies 2 are preferably arranged on each of the object side and the image plane side of the holder 8, and in order to support the holder 8 accurately without being biased in a certain direction, It is more preferable that at least three spherical bodies 2 are arranged on each of the object side and the image plane side.

  Further, when the contact area between the spherical body 2 and the holder 8 increases, the frictional force generated on the holder 8 side increases. That is, in the actuator 22, the strength of the force that supports the movement of the holder 8 in the optical axis direction is proportional to the magnitude of the frictional force (contact area) generated between the spherical body 2 and the holder 8. The contact area between the spherical body 2 and the holder 8 can be adjusted by changing the number of the spherical bodies 2 to be arranged. Therefore, by appropriately changing the number of the spherical bodies 2 to be arranged, the frictional force generated between the spherical body 2 and the side surface of the holder 8 is changed to the volume of the magnetic circuit portion and the amount of current applied to the magnetic circuit. It can be changed to correspond.

  In the actuator 22, the plurality of spherical bodies 2 are preferably provided on both the object side and the image plane side of the holder 8. In other words, when the actuator 22 is viewed from the optical axis direction, the plurality of spherical bodies 2 are preferably disposed so as to sandwich the holder 8 from a direction perpendicular to the optical axis direction. Furthermore, the spherical body 2 is, for example, a position where the contact surfaces of the plurality of spherical bodies 2 and the holder 8 face each other along a line parallel to the optical axis of the lens 13, that is, a line perpendicular to the optical axis of the lens 13. It is preferable to arrange them at positions that are symmetrical with respect to each other. As described above, the plurality of spherical bodies 2 are arranged on the object side and the image plane side of the holder 8 at positions symmetrical to the line perpendicular to the optical axis of the lens 13, thereby supporting the holder 8. There is no bias in directions other than the optical axis direction. That is, the plurality of spherical bodies 2 can more accurately support the movement of the holder 8 in the optical axis direction.

  Such a spherical body 2 is preferably made of a nonmagnetic material. The spherical body 2 made of a nonmagnetic material does not affect the magnetic field distribution of the spherical body 2 even in a strong magnetic field and does not affect the magnetic flux distribution by the magnetic circuit. When the spherical body 2 is made of a nonmagnetic material, the operation (rotation) of the spherical body 2 is not affected by the magnetic force generated from the magnetic circuit. Examples of the nonmagnetic material include ceramic, brass, glass, and nonmagnetic stainless steel.

  The arrangement of the plurality of spherical bodies 2 will be described in more detail with reference to FIGS. 2, 5, and 6. FIG. 5 is a top view of the actuator 22 according to the present invention on the object side, and FIG. 6 is a top view of the image plane side of the actuator 22 according to the present invention. As shown in FIG. 2, the spherical bodies 2 are respectively disposed in the space between the upper guide 3 and the holder 8 and the space between the base portion 9 and the holder 8. As shown in FIG. 5, three spherical bodies 2 are arranged between the object side of the holder 8 and the upper guide 3. Further, as shown in FIG. 6, three spherical bodies 2 are arranged between the image plane side of the holder 8 and the base portion 9. That is, a total of six spherical bodies 2 are arranged in the actuator 22.

  Then, three line segments connecting the three spherical bodies 2 provided between the object side of the holder 8 and the upper guide 3 and the central axis of the holder 8 form an angle of about 120 ° with each other. Yes. In other words, an equilateral triangle can be drawn by connecting the positions where the three spherical bodies 2 are arranged using straight lines. That is, the spherical bodies 2 are arranged at substantially equal intervals from each other at the object-side end of the holder 8. Thereby, it is possible to accurately support the holder 8 without being biased in a certain direction. The three spherical bodies 2 provided between the image plane side of the holder 8 and the base portion 9 are also arranged in the same manner.

  As shown in FIGS. 5 and 6, the holder 8 is formed in parallel with the optical axis and has a groove 8 e for accommodating the spherical body 2. The groove 8e is formed in the holder 8 in a concave shape that continues from the object side to the image plane side. In the present embodiment, three spherical bodies 2 are arranged on the object side and the image plane side of the holder 8 respectively, so that the groove 8e is also formed at three places. The spherical body 2 disposed on the object side of the holder 8 is in contact with the upper guide 3 while being accommodated in the groove portion 8e of the holder 8, and the spherical body 2 disposed on the image plane side of the holder 8 is The base portion 9 is in contact with the groove portion 8e.

  In the upper guide 3, a lever 3c is formed at a position corresponding to one of the three places where the groove 8e is formed. In the base portion 9, a lever 9c is formed at one of the three locations where the groove 8e is formed. The levers 3c and 9c have elasticity in the direction perpendicular to the optical axis. For this reason, the levers 3c and 9c urge the holder 8 in the direction of the other two spherical bodies 2 via the spherical bodies 2 in contact therewith.

  Thereby, when the holder 8 moves in the optical axis direction, the spherical body 2 rotates between the groove portion 8e and the upper guide 3 or the base portion 9, and the movement of the holder 8 is caused by the friction force generated between the groove portion 8e. Support. The number of levers 3c and 9c is not limited to this, and the levers 3c and 9c may be formed at all positions corresponding to the three places where the groove 3e is formed. Further, when four spherical bodies 2 are arranged on the object side and the image plane side of the holder 8, it is preferable that the levers 3 c and 9 c are formed at two locations, respectively.

  As described above, the groove 8e is formed in the holder 8, and the levers 3c and 9c are formed in the upper guide 3 and the base 9, so that when the holder 8 moves in the optical axis direction, the holder 8 and the spherical body The contact with 2 becomes more reliable, and the occurrence of the problem that the spherical body 2 is separated from the holder 8 can be avoided.

  Further, in the upper guide 3 and the base portion 9, a guide side groove portion 3d or a base portion side groove portion 9d is formed at a position corresponding to the groove portion 8e of the holder 8 where the levers 3c and 9c are not formed. May be. The guide side groove 3 d or the base side groove 9 d is a minute groove, and the depth of the groove is shallower than the groove 8 e of the holder 8. Since the guide side groove 3d and the base side groove 9d have a groove shape parallel to the optical axis, the spherical body 2 rotates along the guide side groove 3d and the base side groove 9d. That is, the spherical body 2 is restricted from moving in the direction perpendicular to the optical axis by the guide side groove 3d and the base side groove 9d.

  Here, the spherical body 2 is used as a member for supporting the holder 8. However, the spherical body 2 is not necessarily spherical as long as it is rotatable between the holder 8 and the upper guide 3 and the base portion 9. It may be a body or the like. Since the spherical body 2 can be rotated in any direction between the holder 8 and the upper guide 3 and the base portion 9, it can be supported so that the movement of the holder 8 in the optical axis direction can be performed more smoothly. preferable. On the other hand, when a cylindrical body is used, it may be arranged so that its rotation axis is perpendicular to the optical axis. Thereby, the holder 8 can be moved in a direction parallel to the optical axis by rotating the cylindrical body.

  In the actuator 22, each of the three spherical bodies 2 disposed between the holder 8 and the upper guide 3, and the three spherical bodies 2 disposed between the holder 8 and the base portion 9. They are arranged so as to overlap each other in the optical axis direction (become the same phase). Similarly, the lever 9c and the lever 3c are arranged so as to overlap (in the same phase) in the optical axis direction. Therefore, the direction of the urging (load) from the lever 3c and the lever 9c applied to the holder 8 is constant, so that the operation of the holder 8 in the optical axis direction is more stable.

(Holder 8)
Here, the movement range when the holder 8 is moved by the thrust from the magnetic circuit will be described below with reference to FIG. 4 is a cross-sectional view of the imaging device 21 according to the present embodiment, and shows a cross section when cut at a position different from the cross-sectional view shown in FIG. 2 is a cross-sectional view of a position where the spherical body 2 of the imaging device 21 is disposed, and FIG. 4 is a cross-sectional view of a position where the spherical body 2 of the imaging device 21 is not disposed.

  As shown in FIG. 4, a part of the holder 8 and a part of the upper guide 3 and the base part 9 are provided so as to overlap in the optical axis direction. Therefore, the holder 8 moves only to a position where it comes into contact with the upper guide 3 and the base portion 9. In other words, the movement range of the holder 8 in the optical axis direction is limited by the upper guide 3 and the base portion 9.

  The holder 8 has abutting portions 80 and 81 capable of abutting against the upper guide 3 or the base portion 9 at the end on the side orthogonal to the optical axis direction, that is, the outer wall thereof. The contact portions 80 and 81 are formed at both the object side end portion and the image plane side end portion of the holder 8. A contact portion (first contact portion) 80 formed at the object side end portion has a first axial contact surface 8b and a first rotational contact surface 8a (FIG. 5). . Further, the abutting portion (second abutting portion) 81 formed at the image plane side end portion has a second axial abutting surface 8d and a second rotational abutting surface 8c (FIG. 6). is doing.

  The upper guide 3 has a restricting portion (first restricting portion) 30 that can come into contact with the holder 8 on the ring-shaped gap side that accommodates the holder 8. The restricting portion 30 faces the abutting portion 80 on the object side of the holder 8, and includes a first rotation direction restricting surface 3 a facing the first rotation direction abutting surface 8 a substantially in parallel with the first axis. And a first axial regulating surface 3b facing the direction contact surface 8b substantially in parallel.

  The base portion 9 has a restricting portion (second restricting portion) 90 that can come into contact with the holder 8 on the ring-shaped gap side that accommodates the holder 8. The restricting portion 90 faces the contact portion 81 on the image surface side of the holder 8, and includes a second rotation direction restricting surface 9 a facing the second rotation direction contact surface 8 c substantially in parallel, And a second axial regulating surface 9b facing the axial contact surface 8d substantially in parallel.

  Here, as shown in FIG. 5, the contact portion 80 has a concave shape, and the restricting portion 30 is formed in a convex shape that fits into the concave shape contact portion 80. Accordingly, the surfaces corresponding to the first rotational contact surface 8a, the first axial contact surface 8b, the first axial restriction surface 3a, and the first axial restriction surface 3b as described above. Is forming. In addition, the restriction part 30 may be formed in a concave shape, and the contact part 80 may be formed in a convex shape that fits into the concave shape restriction part 30. Similarly, as shown in FIG. 6, the abutting portion 81 has a concave shape, and the restricting portion 90 is formed in a convex shape that fits into the concave abutting portion 80.

  As shown in FIG. 4, the holder 8 and the upper guide 3 are provided such that the first axial contact surface 8 b and the first axial restriction surface 3 b partially overlap vertically in the optical axis direction. Yes. Therefore, the holder 8 moves only to a position where the first axial contact surface 8 b of the contact portion 80 contacts the first axial restriction surface 3 b of the restriction portion 30. That is, the movement range of the holder 8 toward the object side along the optical axis direction is limited by the upper guide 3.

  Further, the holder 8 and the base portion 9 are provided such that the second axial contact surface 8d and the second axial contact surface 9b partially overlap vertically in the optical axis direction. Accordingly, the holder 8 moves only to a position where the second axial contact surface 8d of the contact portion 81 contacts the second axial restriction surface 9b of the restriction portion 90. That is, the range of movement of the holder 8 toward the image plane along the optical axis direction is limited by the base portion 9. As described above, in the actuator 22, the upper guide 3 and the base portion 9 function to limit (determine) the movement range of the holder 8 in the optical axis direction.

  Next, the structure which restrict | limits the moving range in the rotation direction of the holder 8 is demonstrated in detail below with reference to FIGS. 7 is a diagram showing a part of FIG. 5 showing a top view of the actuator 22 on the object side, and FIG. 8 is a diagram showing a part of FIG. 6 showing a top view of the actuator 22 on the image side.

  Here, as shown in FIGS. 2 and 4, a screw is formed on the inner peripheral surface of the holder 8 that accommodates the barrel 14 and is attached by screwing the barrel 14 that holds the lens 13. The movement of the holder 8 when the barrel 14 is attached to the holder 8 will be described as an example. As shown in FIG. 5, when the actuator 22 is viewed from the object side, the barrel 14 rotates in the clockwise direction indicated by the arrow. At this time, the holder 8 rotates in the clockwise direction by the fitting torque of the screw. When the actuator 22 is viewed from the image plane side as shown in FIG. 6, the barrel 14 rotates in the counterclockwise direction indicated by the arrow, and the holder 8 rotates in the counterclockwise direction. 7 and 8 show enlarged views of parts of FIGS. 5 and 6.

  As shown in FIG. 7, when the barrel 14 rotates in the screwing direction (clockwise direction in FIG. 5), the spherical body 2 comes into contact with one end of the guide side groove 3 d and one end of the groove 8 e of the holder 8. Move to. At this time, the first rotation direction contact surface 8 a of the contact portion 80 of the holder 8 is not in contact with the first rotation direction restriction surface 3 a of the restriction portion 30 of the upper guide 3. Normally, the barrel 14 is screwed into the holder 8 in the state shown in FIGS. 5 and 7. However, if the screw fitting torque is large due to defective parts of the barrel 14 or the holder 8, the holder 8 is further rotated in the rotational direction. There is a possibility of moving a lot. In such a case, in the actuator 22, the first rotation direction contact surface 8a contacts the first rotation direction regulating surface 3a and receives the fitting torque. As a result, the holder 8 is prevented from rotating significantly with the optical axis as a rotation axis, and the holder 8 and the upper guide 3 are prevented from contacting each other. The contact can also be avoided by deforming the lever 3 c away from the holder 8.

  Similarly, as shown in FIG. 8, on the image plane side, the barrel 14 rotates in the screwing direction (counterclockwise direction in FIG. 6), so that the spherical body 2 has one end of the base-side groove portion 9d and a holder. 8 moves to a position in contact with one end of the groove 8e. At this time, even if the fitting torque of the screw is large, the second rotation direction contact surface 8c contacts the second rotation direction regulating surface 9a and receives the fitting torque. As a result, the holder 8 is prevented from rotating significantly with the optical axis as a rotation axis, and the holder 8 and the base portion 9 are prevented from contacting each other. The contact can also be avoided by deforming the lever 9c away from the holder 8.

  That is, the first rotation direction contact surface 8 a and the second rotation direction contact surface 8 c of the contact portions 80 and 81 formed on the holder 8, and the first rotation direction restriction surface formed on the upper guide 3. 3a and the 2nd rotation direction control surface 9a formed in the base part 9 have restrict | limited the movement range in case the holder 8 rotates by making an optical axis into a rotating shaft. Therefore, contact between the holder 8 and the upper guide 3 or the base portion 9 can be prevented. Further, since the displacement of the holder 8 in a direction other than the optical axis direction can be suppressed, the tilt of the lens 13 with respect to the imaging element 11 (the shift of the optical axis of the optical system with respect to the center of the imaging element 11) increases, and the image quality Leading to a decline.

  Here, in at least one of the first rotation direction contact surface 8a, the second rotation direction contact surface 8c, the first rotation direction restriction surface 3a, and the second rotation direction restriction surface 9a, the lens 13 The length in the optical axis direction is longer than the moving range of the holder 8 in the optical axis direction of the lens 13. Thereby, even when the holder 8 is moved to the most object side or the most moved to the image plane side, the rotation direction contact surface of the holder 8 and the rotation direction regulating surfaces of the upper guide 3 and the base portion 9 are always provided. Therefore, it is possible to more reliably limit the movement range of the holder 8 in the rotation direction.

  When the holder 8 moves in the optical axis direction of the lens 13, the first rotation direction contact surface 8a is not in contact with the first rotation direction regulating surface 3a, and the second rotation direction contact surface 8c. Is not in contact with the second rotation direction regulating surface 9a. Therefore, when the holder 8 moves in the optical axis direction of the lens 13, the holder 8, the upper guide 3 and the base portion 9 do not come into contact with each other, and the holder 8 can be moved stably.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope shown in the appended claims are also included in the technical scope of the present invention.

  According to the present invention, the moving range of the holder can be surely limited even in a downsized and thin actuator, and thus can be applied to all optical devices that form an image based on light from a subject. In particular, it can be suitably used for a camera module for a mobile phone.

1 is a perspective view illustrating an appearance of an imaging apparatus according to an embodiment of the present invention. It is sectional drawing of the imaging device which concerns on one Embodiment of this invention. It is a disassembled perspective view of the imaging device which concerns on one Embodiment of this invention. It is sectional drawing of the imaging device which concerns on one Embodiment of this invention. It is an object side top view of an actuator concerning one embodiment of the present invention. It is an image surface side top view of an actuator concerning one embodiment of the present invention. It is a figure which shows a part of FIG. It is a figure which shows a part of FIG. It is sectional drawing which shows the conventional actuator.

Explanation of symbols

1 Cover 2 Sphere (Rotating member)
3 Upper guide (first support)
3a 1st rotation direction regulation surface 3b 2nd axial direction regulation surface 3c lever 3d guide side groove part 4 leaf spring 5 yoke 6 magnet 7 coil 8 holder 8a 1st rotation direction contact surface 8b 1st axis direction contact Surface 8c Second rotational contact surface 8d Second axial contact surface 8e Groove portion 9 Base portion (second support)
9a Second rotational direction regulating surface 9b Second axial direction regulating surface 9c Lever 9d Base side groove portion 10 Cover 11 Imaging element 12 Sensor substrate 13 Lens 14 Barrel 21 Imaging device 22 Actuator 30 Restriction portion (first restriction portion)
80 Contact portion (first contact portion)
81 Contact part (second contact part)
90 restriction part (second restriction part)

Claims (12)

A holder for holding the lens;
A support that supports the holder so as to be movable in the optical axis direction of the lens;
A rotating member that is rotatably arranged between the holder and the support portion and supports movement of the holder;
The support has a restricting portion that limits a movement range of the holder in an optical axis direction of the lens and a rotation direction around the optical axis of the lens;
The actuator according to claim 1, wherein the holder has a contact portion that contacts the restriction portion when the movement range is restricted by the restriction portion. A plurality of the rotating members are respectively disposed on both end sides of the holder in the optical axis direction of the lens.
The rotating member disposed on one end side of the holder and the rotating member disposed on the other end side of the holder are disposed at positions facing each other along a line parallel to the optical axis of the lens. The actuator according to claim 1, wherein the actuator is provided.   The actuator according to claim 1, wherein the rotating member has a substantially spherical shape or a cylindrical shape. The holder has a plurality of contact portions at substantially equal intervals at an end portion in a direction orthogonal to the optical axis of the lens,
The actuator according to claim 1, wherein the support body has the same number of the restriction portions as the contact portions at a position corresponding to the contact portion. The support is
A first support for supporting one end of the holder in the optical axis direction of the lens;
The actuator according to claim 1, further comprising a second support portion that supports the other end of the holder in the optical axis direction of the lens. The regulation part is
A first restricting portion formed on the first support portion;
Including a second restriction portion formed on the second support portion,
The contact portion is
A first abutting portion formed on one end side of the holder in the optical axis direction of the lens and corresponding to the first restricting portion;
6. The actuator according to claim 5, further comprising: a second abutting portion that is formed on the other end side of the holder in the optical axis direction of the lens and corresponds to a second restricting portion. The first contact portion is
A first axial contact surface orthogonal to the optical axis direction of the lens;
A first rotation direction contact surface parallel to the optical axis direction of the lens,
The second contact portion is
A second axial contact surface perpendicular to the optical axis direction of the lens;
A second rotation direction contact surface parallel to the optical axis direction of the lens,
The first regulatory department
A first axial restriction surface facing the first axial contact surface;
A first rotation direction regulating surface facing the first rotation direction contact surface;
The second regulatory department
A second axial regulating surface facing the second axial contact surface;
The actuator according to claim 6, further comprising a second rotation direction regulating surface facing the second rotation direction contact surface.   The length of the lens in the optical axis direction of at least one of the first rotation direction contact surface, the second rotation direction contact surface, the first rotation direction restriction surface, and the second rotation direction restriction surface is: The actuator according to claim 7, wherein the actuator is longer than the moving range of the holder in the optical axis direction of the lens. When the holder moves in the optical axis direction of the lens,
The first rotational direction contact surface is not in contact with the first rotational direction regulating surface,
The actuator according to claim 7 or 8, wherein the second rotation direction contact surface is not in contact with the second rotation direction regulating surface. Either one of the first contact portion and the first restricting portion is a concave shape, and the other is a convex shape that fits into the concave shape,
The actuator according to claim 6, wherein one of the second contact portion and the second restriction portion has a concave shape, and the other has a convex shape that fits into the concave shape.   An imaging device comprising the actuator according to claim 1.   A portable electronic device comprising the imaging device according to claim 11.

Images