Optical unit

Abstract

To provide an optical unit including: a movable body with an optical module; a fixation body for holding the movable body; and a driving mechanism for rotating the movable body with respect to the fixation body so as to incline an optical axis of the optical module, in which the optical unit can be downsized in an optical axis direction of the optical module while the driving force of the driving mechanism is secured even when the angle of rotation of the movable body with respect to the fixation body is increased.SOLUTION: In an optical unit, a driving mechanism 8 includes: a driving magnet 15 attached to a movable body 3; and a driving coil 16 attached to a fixation body 5. The driving magnet 15 and the driving coil 16 face each other in a direction perpendicular to an optical axis direction of an optical module when the optical module is arranged in a predetermined reference position. The driving magnet 15 is magnetized in the optical axis direction. The magnetic pole of one surface 15a of the driving magnet in the optical axis direction is different from the magnetic pole of an other surface 15b of the driving magnet in the optical axis direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an optical unit mounted on a portable device or the like. [Background technology]

[0002] Conventionally, optical units mounted on smartphones and the like are known (see, for example, Patent Document 1). The optical unit described in Patent Document 1 includes a first movable body having a camera module that is an optical module, a gimbal mechanism that rotatably supports the first movable body, a second movable body that supports the first movable body via the gimbal mechanism, and a rocking mechanism that rocks the first movable body relative to the second movable body. This optical unit also includes a fixed body that holds the first movable body, the second movable body, and the like inside.

[0003] In the optical unit described in Patent Document 1, the rocking mechanism includes a drive magnet fixed to a first movable body and a drive coil fixed to a second movable body. The drive magnet is magnetized in a direction perpendicular to the optical axis direction, which is the direction of the optical axis of the camera module. The drive magnet is magnetized in two poles, with an N pole and an S pole aligned in the optical axis direction. The drive coil is disposed facing the drive magnet in a direction perpendicular to the optical axis direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-56747 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventor of the present application has developed an optical unit 100 (see FIG. 6) including a movable body 101 having an optical module such as a camera module, a fixed body 102 that holds the movable body 101, and a drive mechanism 103 for rotating the movable body 101 relative to the fixed body 102 so that the optical axis L10 of the optical module is tilted. The drive mechanism 103 includes a drive magnet 105 attached to the movable body 101 and a drive coil 106 attached to the fixed body 102. The drive coil 106 is, for example, an air-core coil formed by winding a conductor around an air-core. The drive magnet 105 and the drive coil 106 face each other in a direction perpendicular to the optical axis direction, which is the direction of the optical axis L10 of the optical module, when the optical module is placed at a predetermined reference position where the optical axis L10 of the optical module is not tilted (see FIG. 6(A)).

[0006] If the direction in which the drive magnet 105 and the drive coil 106 face each other when the optical module is placed at the reference position is defined as the facing direction, the inventors of the present application have decided to magnetize the drive magnet 105 in the facing direction in the optical unit 100 under development, as with the optical unit described in Patent Document 1, and to magnetize the drive magnet 105 in two poles so that the N pole and S pole are aligned in the optical axis direction. The movable body 101 is rotatable relative to the fixed body 102 with the direction perpendicular to the optical axis direction and the facing direction as the axis of rotation, and is rotatable relative to the fixed body 102 about a rotation center C10.

[0007] As shown in FIG. 6, one side of the two-pole magnetized driving magnet 105 in the optical axis direction is designated as first magnet portion 105a, the other side of the driving magnet 105 in the optical axis direction is designated as second magnet portion 105b, one effective side of the driving coil 106 wound around an air-core is designated as first coil portion 106a, and the other effective side of the driving coil 106 in the optical axis direction is designated as second coil portion 106b. When the optical module is positioned at the reference position, as shown in FIG. 6(A), magnetic flux passing through the first coil portion 106a is generally generated from the first magnet portion 105a, and magnetic flux passing through the second coil portion 106b is generated from the second magnet portion 105b.

[0008] Therefore, when a current is supplied to the driving coil 106 when the optical module is placed at the reference position, for example, as shown in Fig. 6(A), an electromagnetic force is generated on one side in the optical axis direction generally in the direction indicated by the arrow V11, and an electromagnetic force is generated on the other side in the optical axis direction generally in the direction indicated by the arrow V12. The electromagnetic force generated on one side in the optical axis direction and the electromagnetic force generated on the other side in the optical axis direction are both electromagnetic forces that act in a direction in which it is desired to rotate the movable body 101 relative to the fixed body 102.

[0009] On the other hand, in the optical unit 100, when the rotation angle of the movable body 101 with respect to the fixed body 102 is increased to greatly tilt the optical axis L10 (for example, when the optical axis L10 of the optical module arranged at the reference position is tilted by about 5°), the inventors of the present application have found that a part of the magnetic flux that turns from the first magnet section 105a to the second magnet section 105b may pass through the first coil section 106a, as shown in Fig. 6(B). When a part of the magnetic flux that turns from the first magnet section 105a to the second magnet section 105b passes through the first coil section 106a, when a current is supplied to the driving coil 106, an electromagnetic force is generated on one side of the optical axis direction generally in the direction indicated by the arrow V13, an electromagnetic force is generated on the other side of the optical axis direction generally in the direction indicated by the arrow V14, and an electromagnetic force is generated on one side of the optical axis direction generally in the direction indicated by the arrow V15.

[0010] The electromagnetic force in the direction indicated by the arrow V13 and the electromagnetic force in the direction indicated by the arrow V14 are electromagnetic forces acting in a direction in which it is desired to rotate the movable body 101 relative to the fixed body 102, while the electromagnetic force in the direction indicated by the arrow V15 is an electromagnetic force acting in the opposite direction to the direction in which it is desired to rotate the movable body 101 relative to the fixed body 102. Therefore, in the optical unit 100, when the rotation angle of the movable body 101 relative to the fixed body 102 becomes large, there is a risk that the driving force of the driving mechanism 103 will decrease.

[0011] If the inner diameter of the driving coil 106 is increased so that part of the magnetic flux that flows from the first magnet portion 105a to the second magnet portion 105b does not pass through the first coil portion 106a even when the rotation angle of the movable body 101 relative to the fixed body 102 increases, it is possible to suppress a decrease in the driving force of the driving mechanism 103 even when the rotation angle of the movable body 101 relative to the fixed body 102 increases. However, in this case, the driving coil 106 becomes larger in size in the optical axis direction, which may increase the size of the optical unit 100 in the optical axis direction.

[0012] Therefore, the object of the present invention is to provide an optical unit that includes a movable body having an optical module, a fixed body that holds the movable body, and a driving mechanism for rotating the movable body relative to the fixed body so that the optical axis of the optical module is tilted, which can be made smaller in size in the optical axis direction of the optical module while ensuring the driving force of the driving mechanism even when the rotation angle of the movable body relative to the fixed body becomes large. [Means for solving the problem]

[0013] In order to solve the above problems, the present inventors have conducted various studies. In particular, the present inventors have conducted various studies focusing on the magnetization direction of the drive magnet fixed to the movable body. As a result, the present inventors have discovered that by devising the magnetization direction of the drive magnet fixed to the movable body, it is possible to ensure the driving force of the drive mechanism and reduce the size of the optical unit in the optical axis direction of the optical module, even if the rotation angle of the movable body relative to the fixed body increases.

[0014] The optical unit of the present invention is based on this new finding, and comprises a movable body having an optical module, a fixed body that holds the movable body, and a drive mechanism for rotating the movable body relative to the fixed body so that the optical axis of the optical module is tilted, the drive mechanism comprising a drive magnet attached to the movable body and a drive coil attached to the fixed body, the drive magnet and the drive coil facing each other in a direction perpendicular to the optical axis direction, which is the direction of the optical axis of the optical module when the optical module is positioned at a predetermined reference position, the drive magnet being magnetized in the optical axis direction, and the magnetic pole of one side of the drive magnet in the optical axis direction being different from the magnetic pole of the other side of the drive magnet in the optical axis direction.

[0015] In the optical unit of the present invention, the driving magnet is magnetized in the optical axis direction, and the magnetic poles on one side of the driving magnet in the optical axis direction are different from the magnetic poles on the other side of the driving magnet in the optical axis direction. Therefore, according to the study of the present inventor, in the present invention, even if the inner diameter of the driving coil wound around an air core is reduced and the driving coil is miniaturized in the optical axis direction, and even if the rotation angle of the movable body relative to the fixed body is increased, it is possible to prevent the generation of an electromagnetic force acting in the opposite direction to the direction in which the movable body is desired to rotate relative to the fixed body between the driving magnet and the driving coil. Therefore, in the present invention, even if the rotation angle of the movable body relative to the fixed body is increased, it is possible to miniaturize the optical unit in the optical axis direction of the optical module while ensuring the driving force of the driving mechanism.

[0016] In addition, in the present invention, since the drive magnet is magnetized in the optical axis direction, it is possible to manufacture the drive magnet more easily compared to a case in which the drive magnet is bipolarly magnetized in the optical axis direction, such as drive magnet 105 shown in Fig. 6. Therefore, in the present invention, it is possible to reduce the manufacturing costs of the drive magnet.

[0017] In the present invention, for example, if a predetermined direction perpendicular to the optical axis direction when the optical module is positioned at a reference position is defined as a first direction, and a direction perpendicular to the optical axis direction and the first direction when the optical module is positioned at the reference position is defined as a second direction, the drive mechanism includes, as drive magnets, a first drive magnet for rotating the movable body relative to the fixed body with the first direction as the axis of rotation, and a second drive magnet for rotating the movable body relative to the fixed body with the second direction as the axis of rotation, and includes, as drive coils, a first drive coil arranged opposite the first drive magnet in the second direction, and a second drive coil arranged opposite the second drive magnet in the first direction.

[0018] In the present invention, the optical unit includes, for example, an intermediate member that rotatably holds the movable body, and the fixed body rotatably holds the intermediate member. Also, in the present invention, for example, the optical module is a camera module.

[0019] In the present invention, for example, if the direction in which the drive magnet and the drive coil face each other when the optical module is placed at the reference position is defined as the facing direction, the center of the drive magnet and the center of the drive coil coincide when viewed from the facing direction when the optical module is placed at the reference position, which improves the balance of the drive force of the drive mechanism.

[0020] In the present invention, it is preferable that the width of the drive magnet in the optical axis direction is narrower than the width of the drive coil in the optical axis direction when the optical module is disposed at the reference position. According to the inventor's study, this configuration makes it possible to increase the density of the magnetic flux passing through the drive coil when the optical module is disposed at the reference position, even if the drive magnet is magnetized in the optical axis direction. Therefore, it is possible to ensure the drive force of the drive mechanism when the optical module is disposed at the reference position, even if the drive magnet is magnetized in the optical axis direction.

[0021] In the present invention, if the direction in which the drive magnet and the drive coil face each other when the optical module is disposed at the reference position is defined as the facing direction, it is preferable that the thickness of the drive magnet in the facing direction when the optical module is disposed at the reference position is thicker than the thickness of the drive coil in the facing direction. With this configuration, even if the drive magnet is magnetized in the optical axis direction, it is possible to increase the density of the magnetic flux passing through the drive coil. Therefore, it is possible to increase the driving force of the drive mechanism.

[0022] In the present invention, it is preferable that the movable body includes a resin holder to which the optical module is fixed, and the drive magnet is directly fixed to the holder. With this configuration, it is possible to increase the density of the magnetic flux passing through the drive coil compared to when the drive magnet is fixed to the holder via a back yoke (i.e., when the back yoke is disposed between the drive magnet and the holder). Therefore, it is possible to increase the drive force of the drive mechanism. Effect of the Invention

[0023] As described above, in the present invention, in an optical unit comprising a movable body having an optical module, a fixed body that holds the movable body, and a driving mechanism for rotating the movable body relative to the fixed body so that the optical axis of the optical module is tilted, it is possible to miniaturize the optical unit in the direction of the optical axis of the optical module while ensuring the driving force of the driving mechanism, even if the rotation angle of the movable body relative to the fixed body becomes large. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a schematic plan view illustrating a configuration of an optical unit according to the embodiment of the present invention. [Diagram 2] 2 is a schematic side view for explaining the configuration of the optical unit shown in FIG. [Diagram 3]2A and 2B are schematic diagrams for explaining the configuration of the driving mechanism shown in FIG. 1, in which (A) shows a state in which the optical module is placed at a reference position, and (B) shows a state in which the optical axis of the optical module is greatly tilted. [Figure 4] 2 is a graph showing a simulation result for explaining the effect of the optical unit shown in FIG. 1. [Diagram 5] 2 is a graph showing a simulation result for explaining the effect of the optical unit shown in FIG. 1. [Figure 6] 1A and 1B are schematic diagrams for explaining problems with the conventional technology, in which (A) shows a state in which an optical module is placed at a reference position, and (B) shows a state in which the optical axis of the optical module is significantly tilted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] (Overall configuration of optical unit) Fig. 1 is a schematic plan view for explaining the configuration of an optical unit 1 according to an embodiment of the present invention. Fig. 2 is a schematic side view for explaining the configuration of the optical unit 1 shown in Fig. 1. In the following explanation, as shown in Fig. 1 etc., three mutually orthogonal directions are defined as the X direction, the Y direction, and the Z direction, and the X direction is defined as the left-right direction, the Y direction is defined as the front-rear direction, and the Z direction is defined as the up-down direction. Moreover, the Z1 direction side in Fig. 2 etc., which is one side of the up-down direction, is defined as the "upper" side, and the Z2 direction side in Fig. 2 etc., which is the opposite side, is defined as the "lower" side.

[0027] The optical unit 1 of this embodiment is a small and thin unit mounted on a mobile device such as a smartphone. The optical unit 1 includes a camera module 2 having a lens for shooting and an image sensor as an optical module. The optical unit 1 also includes a shake correction function for avoiding distortion of a captured image caused by shaking during shooting. The optical unit 1 is formed into a thin, flat rectangular parallelepiped shape as a whole. The optical unit 1 of this embodiment is formed so that the shape when viewed from the optical axis direction, which is the direction of the optical axis L of the camera module 2, is a rectangular shape close to a square shape. The four side surfaces of the optical unit 1 are parallel to the ZX plane consisting of the left-right direction and the up-down direction or the YZ plane consisting of the front-back direction and the up-down direction.

[0028] The optical unit 1 includes a movable body 3 having a camera module 2, an intermediate member 4 that rotatably holds the movable body 3, and a fixed body 5 that rotatably holds the intermediate member 4. The movable body 3 is rotatable relative to the intermediate member 4 with a first intersecting direction (V direction in FIG. 1) that intersects with the optical axis L of the camera module 2 as the axial direction of the rotation. That is, the movable body 3 is rotatable relative to the intermediate member 4 with a first axis L1 (see FIG. 1) whose axial direction is the first intersecting direction as the rotation center. The first intersecting direction in this embodiment is perpendicular to the optical axis L. Note that the intermediate member 4 is not shown in FIG. 2.

[0029] The intermediate member 4 is rotatable relative to the fixed body 5 about a second intersecting direction (W direction in FIG. 1) that intersects with the first intersecting direction and also intersects with the optical axis L of the camera module 2 as the axial direction of the rotation. That is, the intermediate member 4 is rotatable relative to the fixed body 5 about a second axis L2 (see FIG. 1) whose axial direction is the second intersecting direction. In this embodiment, the second intersecting direction is perpendicular to the first intersecting direction. In this manner, a two-axis gimbal mechanism is configured between the movable body 3 and the fixed body 5.

[0030] In this embodiment, the camera module 2 is placed at a predetermined reference position when no current is supplied to the driving coil 16 and the driving coil 18 described below. When the camera module 2 is placed at the reference position, the optical axis direction of the camera module 2 coincides with the up-down direction. The front-back direction (Y direction) in this embodiment is a first direction that is a predetermined direction perpendicular to the optical axis direction (up-down direction) when the camera module 2 is placed at the reference position, and the left-right direction (X direction) is a second direction that is a direction perpendicular to the optical axis direction (up-down direction) and the first direction (front-back direction) when the camera module 2 is placed at the reference position.

[0031] In this embodiment, when shake correction is performed in the optical unit 1, the inclination of the optical axis L of the camera module 2 with respect to the vertical direction is a maximum of about 5°, and the rotation angle of the movable body 3 with respect to the fixed body 5 is relatively large. However, since the inclination of the optical axis L with respect to the vertical direction with respect to the optical unit 1 when shake correction is performed is a maximum of about 5°, the optical axis direction of the camera module 2 approximately coincides with the vertical direction.

[0032] Furthermore, when the camera module 2 is disposed at the reference position, the second intersecting direction (W direction) is perpendicular to the optical axis L. That is, when the camera module 2 is disposed at the reference position and the movable body 3 is not rotated relative to the intermediate member 4, the second intersecting direction is perpendicular to the optical axis L. On the other hand, when the movable body 3 is rotated relative to the intermediate member 4, the second intersecting direction intersects with the optical axis L but does not intersect at a right angle.

[0033] The optical unit 1 includes a drive mechanism 7 for rotating the movable body 3 relative to the fixed body 5 so that the optical axis L of the camera module 2 is tilted. The drive mechanism 7 includes a first drive mechanism 8 for rotating the movable body 3 relative to the fixed body 5 with the front-rear direction as the axial direction of the rotation, and a second drive mechanism 9 for rotating the movable body 3 relative to the fixed body 5 with the left-right direction as the axial direction of the rotation. The drive mechanism 7 rotates the movable body 3 relative to the fixed body 5 so that the optical axis L of the camera module 2 is tilted in an arbitrary direction.

[0034] The movable body 3 includes a resin holder 11 to which the camera module 2 is fixed. The holder 11 is formed in a flattened rectangular tube shape with both ends in the optical axis direction open. The outer shape of the holder 11 when viewed from the optical axis direction is square. When the camera module 2 is disposed at the reference position, two of the four sides constituting the outer circumferential surface of the holder 11 having a square outer shape are parallel to the front-rear direction, and the remaining two sides are parallel to the left-right direction.

[0035] The camera module 2 is fixed to the inner peripheral surface of the holder 11. The holder 11 covers the lower end of the camera module 2 from the outer peripheral side. As described above, the camera module 2 includes a lens and an imaging element. The imaging element is disposed on the lower end side of the camera module 2, and a subject disposed on the upper side of the camera module 2 is photographed by the camera module 2.

[0036] As described above, when shake correction is performed in the optical unit 1, the inclination of the optical axis L of the camera module 2 with respect to the vertical direction is a maximum of about 5°, and the optical axis direction of the camera module 2 approximately coincides with the vertical direction. Therefore, if one side in the optical axis direction (specifically, the side on which the subject is arranged in the optical axis direction) is the subject side, and the opposite side to the subject side (specifically, the side on which the imaging element is arranged in the optical axis direction) is the anti-subject side, the subject side approximately coincides with the upper side, and the anti-subject side approximately coincides with the lower side.

[0037] The intermediate member 4 is a leaf spring formed by bending a metal plate having spring properties into a predetermined shape. The intermediate member 4 is composed of a base 4a, two first arms 4b extending from the base 4a toward both sides in a first intersecting direction, and two second arms 4c extending from the base 4a toward both sides in a second intersecting direction.

[0038] A first fulcrum portion (not shown) serving as a fulcrum for rotation of the movable body 3 relative to the intermediate member 4 is disposed on the outer side of the first arm portion 4b in the first intersecting direction. A second fulcrum portion (not shown) serving as a fulcrum for rotation of the intermediate member 4 relative to the fixed body 5 is disposed on the outer side of the second arm portion 4c in the second intersecting direction. The first fulcrum portion includes, for example, a metal support member fixed to the holder 11, and a sphere disposed between the first arm portion 4b and the support member. The second fulcrum portion includes, for example, a support member fixed to a case body 12 (described later) constituting a part of the fixed body 5, and a sphere disposed between the second arm portion 4c and the support member.

[0039] The fixed body 5 holds the movable body 3 via the intermediate member 4. The fixed body 5 includes a frame-shaped resin case body 12 arranged on the outer periphery of the movable body 3 and the intermediate member 4. The intermediate member 4 is rotatably held by the case body 12. The case body 12 is formed in a flat rectangular tube shape with both ends in the up-down direction open. When viewed from the up-down direction, the case body 12 has a square frame shape. When viewed from the up-down direction, two of the four sides constituting the outer periphery of the case body 12, which has a square outer shape, are parallel to the front-rear direction, and the remaining two sides are parallel to the left-right direction. The case body 12 is arranged on the outer periphery of the holder 11.

[0040] In the optical unit 1, when a change in the inclination of the movable body 3 is detected by a predetermined detection mechanism for detecting a change in the inclination of the movable body 3, a current is supplied to at least one of the driving coils 16 and 18 described below based on the detection result of this detection mechanism, and the shake is corrected.

[0041] (Drive mechanism configuration) FIG. 3 is a schematic diagram for explaining the configuration of the first driving mechanism 8 shown in FIG. 1, where (A) is a diagram showing a state in which the camera module 2 is placed at a reference position, and (B) is a diagram showing a state in which the optical axis L of the camera module 2 is significantly tilted.

[0042] As described above, the drive mechanism 7 includes the first drive mechanism 8 and the second drive mechanism 9. The first drive mechanism 8 includes a drive magnet 15 as a first drive magnet attached to the movable body 3, and a drive coil 16 as a first drive coil attached to the fixed body 5. The second drive mechanism 9 includes a drive magnet 17 as a second drive magnet attached to the movable body 3, and a drive coil 18 as a second drive coil attached to the fixed body 5. The drive magnets 15, 17 and the drive coils 16, 18 are disposed below the center of the optical unit 1 in the up-down direction.

[0043] When the camera module 2 is disposed at the reference position, the drive magnet 15 and the drive coil 16 face each other in the left-right direction perpendicular to the optical axis direction, and the drive magnet 17 and the drive coil 18 face each other in the front-rear direction perpendicular to the optical axis direction. In this embodiment, in the first drive mechanism 8, the left-right direction (X direction) is the facing direction in which the drive magnet 15 and the drive coil 16 face each other when the camera module 2 is disposed at the reference position. In the second drive mechanism 9, the front-rear direction (Y direction) is the facing direction in which the drive magnet 17 and the drive coil 18 face each other when the camera module 2 is disposed at the reference position.

[0044] The drive magnet 15 is a permanent magnet formed in a rectangular parallelepiped shape. The drive magnet 15 is fixed to the holder 11. Specifically, the drive magnet 15 is fixed to one of the left and right side surfaces of the holder 11. The drive magnet 15 is also directly fixed to the side surface of the holder 11. In other words, no back yoke is disposed between the side surface of the drive magnet 15 and the side surface of the holder 11, and the side surface of the drive magnet 15 is in contact with the side surface of the holder 11.

[0045] The upper and lower surfaces of the driving magnet 15 are flat surfaces perpendicular to the optical axis direction. The width of the driving magnet 15 in the front-rear direction is wider than the width of the driving magnet 15 in the optical axis direction. The driving magnet 15 is formed in a rectangular parallelepiped shape that is elongated in the front-rear direction. The driving magnet 15 is magnetized in the optical axis direction, and the magnetic pole of the surface of the driving magnet 15 facing the subject (hereinafter referred to as the "subject side surface 15a") is different from the magnetic pole of the surface of the driving magnet 15 facing away from the subject (hereinafter referred to as the "opposite subject side surface 15b"). For example, as shown in FIG. 3, the magnetic pole of the subject side surface 15a is an N pole, and the magnetic pole of the anti-subject side surface 15b is an S pole. In this way, the driving magnet 15 is magnetized with a single pole in the optical axis direction.

[0046] The driving coil 16 is fixed to the case body 12. The driving coil 16 is disposed on one side of the driving magnet 15 in the left-right direction, and is disposed facing the driving magnet 15 in the left-right direction. The driving coil 16 is, for example, an air-core coil formed by winding a conductor around an air-core. The driving coil 16 has two effective sides 16a, 16b that are parallel to the front-rear direction (see FIG. 3). The effective side 16a is disposed above the effective side 16b. The inner diameter of the driving coil 16 is relatively small, and the vertical distance between the effective side 16a and the effective side 16b is relatively narrow. A Hall IC (not shown) for detecting the position of the movable body 3 is disposed on the inner peripheral side of the driving coil 16.

[0047] When the camera module 2 is disposed at the reference position, the center of the drive magnet 15 and the center of the drive coil 16 coincide with each other when viewed from the left-right direction. As shown in Fig. 2, the width W1 of the drive magnet 15 in the optical axis direction is narrower than the width W2 of the drive coil 16 in the up-down direction. That is, the width W1 of the drive magnet 15 in the optical axis direction is narrower than the width W2 of the drive coil 16 in the optical axis direction when the camera module 2 is disposed at the reference position. In addition, the thickness t1 in the left-right direction of the drive magnet 15 when the camera module 2 is disposed at the reference position is thicker than the thickness t2 in the left-right direction of the drive coil 16.

[0048] The driving magnet 17 is a permanent magnet formed in the same shape as the driving magnet 15. The driving magnet 17 is fixed to one side surface of the holder 11 in the front-rear direction. The driving magnet 15 is directly fixed to the side surface of the holder 11. The driving magnet 17 is disposed at the same position as the driving magnet 15 in the up-down direction. Like the driving magnet 15, the driving magnet 17 is magnetized in the optical axis direction, and the magnetic pole of the surface of the driving magnet 17 facing the subject (hereinafter referred to as the "subject side surface 17a") is different from the magnetic pole of the surface of the driving magnet 17 facing away from the subject (hereinafter referred to as the "anti-subject side surface 17b"). For example, the magnetic pole of the subject side surface 17a is an N pole, and the magnetic pole of the anti-subject side surface 17b is an S pole.

[0049] The driving coil 18 is fixed to the case body 12. The driving coil 18 is disposed on one side of the driving magnet 17 in the front-rear direction, and disposed facing the driving magnet 17 in the front-rear direction. The driving coil 18 is formed in the same shape as the driving coil 16. The driving coil 18 has two effective sides 18a, 18b that are parallel to the left-right direction (see FIG. 2). The effective side 18a is disposed above the effective side 18b. A Hall IC (not shown) for detecting the position of the movable body 3 is disposed on the inner peripheral side of the driving coil 18.

[0050] When the camera module 2 is disposed at the reference position, the center of the drive magnet 17 coincides with the center of the drive coil 18 when viewed from the front-rear direction. The width of the drive magnet 17 in the optical axis direction is narrower than the width of the drive coil 18 in the optical axis direction when the camera module 2 is disposed at the reference position. In addition, the thickness of the drive magnet 17 in the front-rear direction when the camera module 2 is disposed at the reference position is thicker than the thickness of the drive coil 18 in the front-rear direction.

[0051] When the camera module 2 is disposed at the reference position, the magnetic flux generated from the drive magnet 15 passes through the drive coil 16, for example, as shown in FIG. 3A. Therefore, when the camera module 2 is disposed at the reference position, if a current is supplied to the drive coil 16, for example, as shown in FIG. 3A, an electromagnetic force is generated above the first drive mechanism 8 in the direction generally indicated by the arrow V1, and an electromagnetic force is generated below the first drive mechanism 8 in the direction generally indicated by the arrow V2. Both the electromagnetic force in the direction indicated by the arrow V1 and the electromagnetic force in the direction indicated by the arrow V2 are electromagnetic forces acting in a direction in which the movable body 3 is to be rotated relative to the fixed body 5. When a current is supplied to the drive coil 16, the movable body 3 rotates about the rotation center C relative to the fixed body 5.

[0052] Furthermore, when the optical axis L of the camera module 2 is tilted significantly by rotating the movable body 3 relative to the fixed body 5 with the front-rear direction as the axis of rotation (for example, when the optical axis L of the camera module 2 placed at the reference position is tilted by about 5°), the magnetic flux generated from the drive magnet 15 passes through the drive coil 16, for example, as shown in Fig. 3(B). Therefore, when a current is supplied to the drive coil 16 when the optical axis L of the camera module 2 is tilted significantly, an electromagnetic force is generated above the first drive mechanism 8 in the direction generally indicated by the arrow V3, and an electromagnetic force is generated below the first drive mechanism 8 in the direction generally indicated by the arrow V4, for example, as shown in Fig. 3(B).

[0053] The electromagnetic force in the direction indicated by the arrow V3 and the electromagnetic force in the direction indicated by the arrow V4 are both electromagnetic forces acting in a direction in which it is desired to rotate the movable body 3 relative to the fixed body 5. Furthermore, when the optical axis L of the camera module 2 is greatly tilted with the front-rear direction as the axis of rotation, the distance between the anti-subject side surface 15b and the effective side portion 16b becomes closer, as shown in Fig. 3(B), for example, and the electromagnetic force generated below the first drive mechanism 8 becomes larger. Alternatively, when the optical axis L of the camera module 2 is greatly tilted with the front-rear direction as the axis of rotation, the distance between the subject side surface 15a and the effective side portion 16a becomes closer, and the electromagnetic force generated above the first drive mechanism 8 becomes larger.

[0054] Similarly, in the second drive mechanism 9, when a current is supplied to the drive coil 18 while the camera module 2 is placed at the reference position, an electromagnetic force is generated on both the upper and lower sides of the second drive mechanism 9 in a direction in which it is desired to rotate the movable body 3 relative to the fixed body 5. Even if the optical axis L of the camera module 2 is greatly tilted by rotating the movable body 3 relative to the fixed body 5 with the left-right direction as the axis of rotation, an electromagnetic force is still generated on both the upper and lower sides of the second drive mechanism 9 in a direction in which it is desired to rotate the movable body 3 relative to the fixed body 5.

[0055] Furthermore, when the optical axis L of the camera module 2 is greatly tilted with the left-right direction as the axis of rotation, for example, the distance between the subject side surface 17a and the effective side portion 18a becomes closer, and the electromagnetic force generated on the upper side of the second drive mechanism 9 becomes larger. Alternatively, when the optical axis L of the camera module 2 is greatly tilted with the left-right direction as the axis of rotation, the distance between the anti-subject side surface 17b and the effective side portion 18b becomes closer, and the electromagnetic force generated on the lower side of the second drive mechanism 9 becomes larger.

[0056] (Main effects of this form) As described above, in this embodiment, the driving magnet 15 is magnetized in the optical axis direction, and the magnetic poles of the subject side surface 15a of the driving magnet 15 are different from the magnetic poles of the anti-subject side surface 15b. Therefore, in this embodiment, even if the inner diameter of the driving coil 16 wound around an air core is reduced and the driving coil 16 is miniaturized in the optical axis direction, and even if the rotation angle of the movable body 3 relative to the fixed body 5 with the front-rear direction as the axis of rotation increases, it is possible to prevent the generation of an electromagnetic force acting in the opposite direction to the direction in which the movable body 3 is desired to rotate relative to the fixed body 5 between the driving magnet 15 and the driving coil 16.

[0057] Similarly, in this embodiment, the driving magnet 17 is magnetized in the optical axis direction, and the magnetic poles of the subject side surface 17a of the driving magnet 17 are different from the magnetic poles of the anti-subject side surface 17b. Therefore, in this embodiment, even if the inner diameter of the driving coil 18 wound around an air core is reduced and the driving coil 18 is miniaturized in the optical axis direction, and even if the rotation angle of the movable body 3 relative to the fixed body 5 with the left-right direction as the axis of rotation becomes large, it is possible to prevent the generation of an electromagnetic force acting in the opposite direction to the direction in which the movable body 3 is desired to rotate relative to the fixed body 5 between the driving magnet 17 and the driving coil 18.

[0058] Therefore, in this embodiment, even if the rotation angle of the movable body 3 relative to the fixed body 5 with the front-rear direction as the axis of rotation increases, or even if the rotation angle of the movable body 3 relative to the fixed body 5 with the left-right direction as the axis of rotation increases, it is possible to reduce the size of the optical unit 1 in the optical axis direction of the camera module 2 while ensuring the driving force of the first driving mechanism 8 and the driving force of the second driving mechanism 9. That is, in this embodiment, even if the rotation angle of the movable body 3 relative to the fixed body 5 increases, it is possible to reduce the size of the optical unit 1 in the optical axis direction of the camera module 2 while ensuring the driving force of the driving mechanism 7.

[0059] The effect of this embodiment, that is, the driving force of the driving mechanism 7 can be ensured even if the rotation angle of the movable body 3 relative to the fixed body 5 increases, will be described in detail based on the simulation results shown in Fig. 4. The solid curve CL1 in Fig. 4 is a graph showing an example of the variation in the driving force of the first driving mechanism 8 or the second driving mechanism 9 when the inclination of the optical axis L of the camera module 2 of this embodiment is varied in the simulation. When the inclination of the optical axis L is 0°, the camera module 2 is disposed at the reference position, and the optical axis direction coincides with the up-down direction.

[0060] 4 is a graph showing an example of the variation in the driving force of the driving mechanism 103 when the inclination of the optical axis L10 of the optical module of the optical unit 100 shown in Fig. 6 is varied in a simulation. In the simulation, a constant current is passed through the driving coil 16 or the driving coil 18, and a constant current is passed through the driving coil 106.

[0061] 4, in the optical unit 1 of this embodiment, even if the rotation angle of the movable body 3 relative to the fixed body 5 increases and the optical axis L of the camera module 2 is significantly tilted, a decrease in the driving force of the first driving mechanism 8 or the second driving mechanism 9 is suppressed compared to the optical unit 100 shown in Fig. 6. In other words, as is clear from the simulation results, in this embodiment, it is possible to ensure the driving force of the driving mechanism 7 even if the rotation angle of the movable body 3 relative to the fixed body 5 increases.

[0062] In this embodiment, the drive magnets 15 and 17 are unipolarly magnetized in the optical axis direction. Therefore, in this embodiment, the drive magnets 15 and 17 can be easily manufactured. Therefore, in this embodiment, the manufacturing cost of the drive magnets 15 and 17 can be reduced.

[0063] In this embodiment, when the camera module 2 is disposed at the reference position, the center of the drive magnet 15 and the center of the drive coil 16 coincide with each other when viewed from the left-right direction, and the width W1 of the drive magnet 15 in the optical axis direction is narrower than the width W2 of the drive coil 16 in the up-down direction. Therefore, in this embodiment, even if the drive magnet 15 is magnetized in the optical axis direction, it is possible to increase the density of the magnetic flux passing through the drive coil 16 when the camera module 2 is disposed at the reference position. Therefore, in this embodiment, even if the drive magnet 15 is magnetized in the optical axis direction, it is possible to ensure the drive force of the first drive mechanism 8 when the camera module 2 is disposed at the reference position.

[0064] Similarly, in this embodiment, when viewed from the front-to-back direction when the camera module 2 is positioned at the reference position, the center of the drive magnet 17 and the center of the drive coil 18 coincide with each other, and the width of the drive magnet 17 in the optical axis direction is narrower than the width of the drive coil 18 in the up-down direction. Therefore, even if the drive magnet 17 is magnetized in the optical axis direction, it is possible to ensure the drive force of the second drive mechanism 9 when the camera module 2 is positioned at the reference position.

[0065] As shown in FIG. 4, the driving force of the first driving mechanism 8 or the second driving mechanism 9 when the camera module 2 is positioned at the reference position (i.e., the driving force of the first driving mechanism 8 or the second driving mechanism 9 when the inclination of the optical axis L of the camera module 2 is 0°) is equivalent to the driving force of the driving mechanism 103 when the optical module is positioned at the reference position in the optical unit 100 shown in FIG. 6.

[0066] In this embodiment, the thickness t1 in the left-right direction of the drive magnet 15 when the camera module 2 is disposed at the reference position is thicker than the thickness t2 in the left-right direction of the drive coil 16. Therefore, in this embodiment, even if the drive magnet 15 is magnetized in the optical axis direction, it is possible to increase the density of the magnetic flux passing through the drive coil 16. Therefore, in this embodiment, it is possible to increase the driving force of the first drive mechanism 8. Similarly, in this embodiment, the thickness in the front-rear direction of the drive magnet 17 when the camera module 2 is disposed at the reference position is thicker than the thickness in the front-rear direction of the drive coil 18. Therefore, even if the drive magnet 17 is magnetized in the optical axis direction, it is possible to increase the density of the magnetic flux passing through the drive coil 18, and as a result, it is possible to increase the driving force of the second drive mechanism 9.

[0067] In this embodiment, the driving magnet 15 is directly fixed to the resin holder 11. Therefore, in this embodiment, it is possible to increase the density of the magnetic flux passing through the driving coil 16 compared to when the driving magnet 15 is fixed to the holder 11 via a back yoke. Therefore, in this embodiment, it is possible to increase the driving force of the first driving mechanism 8. Similarly, in this embodiment, the driving magnet 17 is directly fixed to the resin holder 11, so it is possible to increase the density of the magnetic flux passing through the driving coil 18 compared to when the driving magnet 17 is fixed to the holder 11 via a back yoke. Therefore, in this embodiment, it is possible to increase the driving force of the second driving mechanism 9.

[0068] 5 shows a curve CL2 indicating an example of the variation in the tilt of the optical axis L of the camera module 2 when the current flowing through the drive coil 16 of this embodiment is varied in a simulation, and a curve CL20 indicating an example of the variation in the tilt of the optical axis L10 of the optical module when the current flowing through the drive coil 106 of the optical unit 100 shown in Fig. 6 is varied. As shown in Fig. 5, in the optical unit 1 of this embodiment, compared to the optical unit 100, even if the tilt of the optical axis L of the camera module 2 becomes large, the optical axis L is more likely to tilt in response to the current flowing through the drive coil 16.

[0069] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications are possible without departing from the spirit and scope of the present invention.

[0070] In the above-described embodiment, the first drive mechanism 8 may include two drive magnets 15 and two drive coils 16 arranged on both sides in the left-right direction of the holder 11. Similarly, in the above-described embodiment, the second drive mechanism 9 may include two drive magnets 17 and two drive coils 18 arranged on both sides in the front-rear direction of the holder 11.

[0071] In the above-mentioned embodiment, the thickness t1 in the left-right direction of the drive magnet 15 when the camera module 2 is disposed at the reference position may be the same as the thickness t2 in the left-right direction of the drive coil 16, or may be thinner than the thickness t2. Similarly, the thickness in the front-rear direction of the drive magnet 17 when the camera module 2 is disposed at the reference position may be the same as the thickness in the front-rear direction of the drive coil 18, or may be thinner than the thickness in the front-rear direction of the drive coil 18. Also, in the above-mentioned embodiment, the width W1 of the drive magnet 15 in the optical axis direction may be the same as the width W2 in the up-down direction of the drive coil 16, or may be wider than the width W2. Similarly, the width of the drive magnet 17 in the optical axis direction may be the same as the width in the up-down direction of the drive coil 18, or may be wider than the width in the up-down direction of the drive coil 18.

[0072] In the above-described embodiment, the optical unit 1 may not include the intermediate member 4. In this case, for example, the optical unit 1 includes a fulcrum portion disposed below the movable body 3, and a spring member that urges the movable body 3 toward the fulcrum portion with respect to the fixed body 5, and the fixed body 5 holds the movable body 3 via the spring member. The spring member is, for example, a leaf spring, and includes a fixed body fixing portion fixed to the fixed body 5, a movable body fixing portion fixed to the movable body 3, and a plurality of arms that connect the fixed body fixing portion and the movable body fixing portion. The spring member may also be a wire spring.

[0073] In the above-described embodiment, the optical unit 1 may include a rotation mechanism that rotates the camera module 2 relative to the intermediate member 4 around the optical axis L of the camera module 2. In this case, the intermediate member 4 includes a first intermediate member and a second intermediate member. The movable body 3 is rotatable relative to the first intermediate member around the optical axis L of the camera module 2, and the first intermediate member is rotatable relative to the second intermediate member around the first axis L1.

[0074] In the above-described embodiment, the optical module of the optical unit 1 may be a module other than the camera module 2. For example, the optical module may be a LiDAR (Light Detection and Ranging) scanner that reads the distance of an object by using reflection of laser light. In addition, in the above-described embodiment, the drive mechanism 7 does not need to include the first drive mechanism 8 or the second drive mechanism 9. In addition, in the above-described embodiment, the optical unit 1 may be mounted on various devices other than a portable device.

[0075] (Configuration of this technology) The present technology can be configured as follows. (1) A movable body having an optical module, a fixed body for holding the movable body, and a drive mechanism for rotating the movable body with respect to the fixed body so that an optical axis of the optical module is tilted, the drive mechanism includes a drive magnet attached to the movable body and a drive coil attached to the fixed body; the drive magnet and the drive coil face each other in a direction perpendicular to an optical axis direction that is a direction of an optical axis of the optical module when the optical module is disposed at a predetermined reference position, The driving magnet is magnetized in the optical axis direction, An optical unit, characterized in that the magnetic poles of one surface of the drive magnet in the optical axis direction are different from the magnetic poles of the other surface of the drive magnet in the optical axis direction. (2) A predetermined direction perpendicular to the optical axis direction when the optical module is disposed at the reference position is defined as a first direction, and a direction perpendicular to the optical axis direction and the first direction when the optical module is disposed at the reference position is defined as a second direction, The optical unit described in (1) is characterized in that the driving mechanism includes, as the driving magnet, a first driving magnet for rotating the movable body relative to the fixed body with the first direction as the axial direction of rotation, and a second driving magnet for rotating the movable body relative to the fixed body with the second direction as the axial direction of rotation, and includes, as the driving coil, a first driving coil arranged opposite the first driving magnet in the second direction, and a second driving coil arranged opposite the second driving magnet in the first direction. (3) An intermediate member that rotatably holds the movable body, The optical unit according to (2), wherein the fixed body rotatably holds the intermediate member. (4) The optical unit according to any one of (1) to (3), wherein the optical module is a camera module. (5) If a direction in which the drive magnet and the drive coil face each other when the optical module is disposed at the reference position is defined as a facing direction, An optical unit described in any of (1) to (4), characterized in that when the optical module is positioned at the reference position and viewed from the opposing direction, the center of the drive magnet and the center of the drive coil coincide. (6) An optical unit as described in (5), characterized in that the width of the driving magnet in the optical axis direction is narrower than the width of the driving coil in the optical axis direction when the optical module is positioned at the reference position. (7) If a direction in which the drive magnet and the drive coil face each other when the optical module is disposed at the reference position is defined as a facing direction, An optical unit described in any of (1) to (6), characterized in that the thickness of the drive magnet in the opposing direction when the optical module is positioned at the reference position is thicker than the thickness of the drive coil in the opposing direction. (8) The movable body includes a resin holder to which the optical module is fixed, The optical unit according to any one of (1) to (7), wherein the drive magnet is directly fixed to the holder. [Explanation of symbols]

[0076] 1 Optical unit 2 Camera module (optical module) 3 Movable body 4 Intermediate parts 5 Fixed body 7 Driving mechanism 11 Holder 15 Drive magnet (first drive magnet) 15a, 17a: Subject side surface (one surface of the driving magnet in the optical axis direction) 15b, 17b: Side opposite to the subject (the other side of the driving magnet in the optical axis direction) 16 Drive coil (first drive coil) 17 Drive magnet (second drive magnet) 18 Drive coil (second drive coil) L optical axis t1 Thickness of the drive magnet in the opposing direction t2 Thickness of the driving coil in the opposing direction W1 Width of the drive magnet in the optical axis direction W2 Width of the driving coil in the optical axis direction X 2nd direction, opposite direction Y 1st direction, opposite direction

Claims

1. a movable body having an optical module, a fixed body that holds the movable body, and a drive mechanism that rotates the movable body relative to the fixed body so that an optical axis of the optical module is tilted; the drive mechanism includes a drive magnet attached to the movable body and a drive coil attached to the fixed body; the drive magnet and the drive coil face each other in a direction perpendicular to an optical axis direction that is a direction of an optical axis of the optical module when the optical module is disposed at a predetermined reference position, The driving magnet is magnetized in the optical axis direction, An optical unit, characterized in that the magnetic poles of one surface of the drive magnet in the optical axis direction are different from the magnetic poles of the other surface of the drive magnet in the optical axis direction.

2. A predetermined direction perpendicular to the optical axis direction when the optical module is disposed at the reference position is defined as a first direction, and a direction perpendicular to the optical axis direction and the first direction when the optical module is disposed at the reference position is defined as a second direction. The optical unit described in claim 1, characterized in that the driving mechanism includes, as the driving magnet, a first driving magnet for rotating the movable body relative to the fixed body with the first direction as the axial direction of rotation, and a second driving magnet for rotating the movable body relative to the fixed body with the second direction as the axial direction of rotation, and includes, as the driving coil, a first driving coil arranged opposite the first driving magnet in the second direction, and a second driving coil arranged opposite the second driving magnet in the first direction.

3. an intermediate member that rotatably holds the movable body, 3. The optical unit according to claim 2, wherein the fixed body holds the intermediate member so as to be rotatable.

4. 4. The optical unit according to claim 1, wherein the optical module is a camera module.

5. When the optical module is disposed at the reference position, the direction in which the drive magnet and the drive coil face each other is defined as an opposing direction.

4. An optical unit as described in claim 1, wherein when the optical module is disposed at the reference position and viewed from the opposing direction, the center of the drive magnet and the center of the drive coil coincide with each other.

6. 6. The optical unit according to claim 5, wherein the width of the driving magnet in the optical axis direction is narrower than the width of the driving coil in the optical axis direction when the optical module is positioned at the reference position.

7. When the optical module is disposed at the reference position, the direction in which the drive magnet and the drive coil face each other is defined as an opposing direction. An optical unit as described in any one of claims 1 to 3, characterized in that the thickness of the drive magnet in the opposing direction when the optical module is positioned at the reference position is thicker than the thickness of the drive coil in the opposing direction.

8. the movable body includes a resin holder to which the optical module is fixed, 4. The optical unit according to claim 1, wherein the drive magnet is directly fixed to the holder.

Images