OPTICAL UNIT WITH RUNOUT CORRECTION FUNCTION

An optical unit with a runout correction function includes a reflection member, a camera module having a lens and an image pickup element, a holding member that rotatably holds the reflection member and also holds the camera module, and a fixing member that rotatably holds the holding member. A second rotation mechanism rotates the reflection member held in the holding member with an optical axis direction, which is a direction of an optical axis of the lens, as an axis direction of the rotation and is capable of runout correction in a yaw direction. In the optical unit with a runout correction function, when the runout correction in the yaw direction is performed, the image pickup element held in the holding member is rotated together with the reflection member with the optical axis direction as the axis direction of rotation.

BACKGROUND

Field of the Invention

At least an embodiment of the present invention relates to an optical unit with a runout correction function having a runout correction function to correct runout of an optical image.

Description of the Related Documents

Conventionally, an optical unit with a runout correction function, which corrects the runout of an optical image by oscillating a reflection portion having a mirror, is known (see, for example, JP 2021-27431 Gazette 1). The optical unit described in JP 2021-27431 Gazette 1 includes a lens unit, an image pickup element mounted on a substrate, and a reflection-portion oscillating mechanism to oscillate the reflection portion with respect to the lens unit and the image pickup element. The reflection-portion oscillating mechanism rotates the reflection portion with respect to the lens unit and the image pickup element with a pitch direction (pitching direction) as an axis direction of rotation, and rotates the reflection portion with respect to the lens unit and the image pickup element with a yaw direction (yawing direction) as the axis direction of rotation.

In the case of the optical unit described in JP 2021-27431, if the reflection portion is rotated with respect to the image pickup element using the yaw direction as the axis direction of rotation, there is a concern that an image acquired by the image pickup element would be inclined. Even if the image acquired by the image pickup element is inclined, the inclination of the image can be corrected by performing electronic correction on the image acquired by the image pickup element. However, if electronic correction is performed on the image acquired by the image pickup element, the image after the correction may be deteriorated and the image quality may be degraded. In addition, when wide-angle correction is performed, the image after the correction is more likely to be degraded.

Therefore an object of at least an embodiment of the present invention is to provide an optical unit with a runout correction function which can prevent inclination of an image acquired by an image pickup element, even if runout correction is performed in the yaw direction, in an optical unit with a runout correction function, capable of correcting runout in the pitch direction and in the yaw direction.

SUMMARY

In order to solve the above problem, the optical unit with a runout correction function of at least an embodiment of the present invention includes a reflection member on which a reflection surface is formed to reflect light incident from an outside, a camera module having a lens through which the light reflected by the reflection surface passes and an image pickup element to which the light having passed through the lens enters, a holding member that rotatably holds the reflection member and also holds the camera module, a fixing member that rotatably holds the holding member, a first rotation mechanism that rotates the reflection member with respect to the holding member, and a second rotation mechanism that rotates the holding member with respect to the fixing member, in which an optical axis direction, which is a direction of an optical axis of the lens, and an incident direction of the light to the reflection surface are orthogonal to each other, the first rotation mechanism rotates the reflection member with respect to the holding member with a direction orthogonal to the optical axis direction and intersecting the incident direction as the axis direction of rotation, and the second rotation mechanism rotates the holding member with respect to the fixing member with the optical axis direction as the axis direction of rotation.

The optical unit with a runout correction function of at least an embodiment of the present invention has the reflection member, the camera module having the lens and the image pickup element, the holding member that rotatably holds the reflection member and also holds the camera module, and the fixing member that rotatably holds the holding member, and the second rotation mechanism rotates the holding member with the optical axis direction, which is a direction of an optical axis of the lens, as an axis direction of the rotation. In other words, in at least an embodiment of the present invention, the second rotation mechanism rotates the reflection member held in the holding member with the optical axis direction as the axis direction of rotation and thus, runout correction in the yaw direction is enabled. Moreover, in at least an embodiment of the present invention, when the holding member is rotated to correct the runout in the yaw direction, the image pickup element held in the holding member is rotated together with the reflection member with the optical axis direction as the axis direction of rotation. Therefore, in at least an embodiment of the present invention, inclination of the image acquired by the image pickup element can be prevented even when the runout correction in the yaw direction is performed.

In at least an embodiment of the present invention, an axis of rotation of the holding member with respect to the fixing member is preferably matched with an optical axis of the lens. With this configuration, more appropriate runout correction in the yaw direction can be performed by rotating the holding member with respect to the fixing member.

In at least an embodiment of the present invention, the axis of rotation of the holding member with respect to the fixing member preferably passes through the center of gravity of a movable body which includes the reflection member, the camera module, and the holding member and which is rotatable with respect to the fixing member with the optical axis direction as the axis direction of rotation. With this configuration, the movable body can be smoothly rotated with respect to the fixing member by the second rotation mechanism.

In at least an embodiment of the present invention, the first rotation mechanism includes a drive magnet and a drive coil opposed to each other in the optical axis direction, and the drive magnet and the drive coil are preferably disposed on the axis of rotation of the holding member with respect to the fixing member. With this configuration, even in a state where the holding member is rotated with respect to the fixing member (that is, even in a state where the runout correction in the yaw direction is being performed), misalignment between the drive magnet and the drive coil can be suppressed. Therefore, even in the state where the runout correction in the yaw direction is being performed, the runout correction in the pitch direction can be properly performed.

In at least an embodiment of the present invention, it is more preferable that the center of the drive magnet and the center of the drive coil are disposed on the axis of rotation of the holding member with respect to the fixing member when the reflection member is disposed at a predetermined reference position with respect to the holding member. With this configuration, even in the state where the holding member is rotated with respect to the fixing member, the misalignment between the drive magnet and the drive coil can be effectively suppressed. Therefore, even in the state where the runout correction in the yaw direction is being performed, the runout correction in the pitch direction can be performed more properly.

In at least an embodiment of the present invention, it is preferable that the optical unit with a runout correction function includes a magnetic sensor detecting a position of the reflection member with respect to the holding member, the magnetic sensor is opposed to the drive magnet in the optical axis direction, and the magnetic sensor is disposed on the axis of rotation of the holding member with respect to the fixed member. With this configuration, even in the state where the holding member is rotated with respect to the fixing member (that is, even in the state where the runout correction in the yaw direction is being performed), misalignment between the drive magnet and the magnetic sensor can be suppressed. Therefore, even in the state where the runout correction in the yaw direction is being performed, the position of the reflection member with respect to the holding member can be properly detected in the pitch direction.

In at least an embodiment of the present invention, it is more preferable that a center of the magnetic sensor is disposed on the axis of rotation of the holding member with respect to the fixing member when the reflection member is disposed at the reference position with respect to the holding member. With this configuration, even in the state where the holding member is rotated with respect to the fixing member, the misalignment between the drive magnet and the magnetic sensor can be effectively suppressed. Therefore, even in the state where the runout correction in the yaw direction is being performed, the position of the reflection member with respect to the holding member can be detected more properly in the pitch direction.

As described above, with at least an embodiment of the present invention, inclination of an image acquired by the image pickup element can be prevented even when the runout correction in the yaw direction is performed in the optical unit with a runout correction function, capable of the runout correction in the pitch direction and the yaw direction.

DETAILED DESCRIPTION

Configuration of Optical Unit with Runout Correction Function

FIG. 1is a plan view of an optical unit1with a runout correction function according to an embodiment of the present invention.FIG. 2is a perspective view of a smartphone2in which the optical unit1with a runout correction function shown inFIG. 1is incorporated.FIG. 3is a schematic diagram for explaining a configuration of an optical system of the optical unit1with a runout correction function shown inFIG. 1.FIG. 4is an exploded perspective view of the optical unit1with a runout correction function shown inFIG. 1.FIG. 5is a cross-sectional view of an E-E section ofFIG. 1.FIG. 6is a cross-sectional view of an F-F section ofFIG. 1.

The optical unit1with a runout correction function (hereinafter referred to as “optical unit1”) in this embodiment is a camera with a runout correction function to correct the runout of an optical image. The optical unit1is, for example, incorporated in a smartphone2. A lens3for photographing is attached to the smartphone2. Light that has passed through the lens3enters the optical unit1. Note that the optical unit1may be incorporated in a portable device or the like other than the smartphone2.

The optical unit1has a prism5as a reflection member on which a reflection surface5athat reflects light incident from the outside is formed, and a camera module8having a lens6and an image pickup element7(seeFIG. 3). The image pickup element7is, for example, a CMOS image sensor. The term “lens6” in this specification is supposed to include not only a single lens but also a lens group consisting of a plurality of lenses. The lens6in this embodiment is a lens group consisting of a plurality of lenses.

Moreover, the optical unit1has a holder9as a holding member to hold the prism5and the camera module8, and a housing10as a fixing member to hold the holder9. The prism5is rotatably held in the holder9. The holder9is rotatably held in the housing10. The optical unit1includes a first rotation mechanism11to rotate the prism5with respect to the holder9and a second rotation mechanism12to rotate the holder9with respect to the housing10.

The prism5is fixed to a prism holder15. In other words, the optical unit1includes the prism holder15to which the prism5is fixed. The prism holder15is formed of a resin material. The prism holder15is rotatably held in the holder9, and the prism5is rotatably held in the holder9via the prism holder15. Moreover, the optical unit1includes a rotating shaft portion16which constitutes rotation centers of the prism5and the prism holder15with respect to the holder9, and a rotating shaft portion17which constitutes a rotation center of the holder9with respect to the housing10.

The reflection surface5aof the prism5receives the light that has passed through the lens3. The reflection surface5areflects light incident to the reflection surface5athrough the lens3toward the image pickup element7. The reflection surface5abends the optical axis of the light incident to the reflection surface5aby approximately 90°. The light reflected by the reflection surface5apasses through the lens6, and the light having passed through the lens6enters the image pickup element7. An optical axis L1of the lens3is orthogonal to an optical axis L2of the lens6. That is, the optical axis direction, which is the direction of the optical axis L2of the lens6, is orthogonal to the incident direction of the light to the reflection surface5a.The normal line passing through the center of the imaging surface of the image pickup element7is matched with the optical axis L2of the lens6.

In the following description, it is assumed that the incident direction of light to the reflection surface5a(that is, the direction of the optical axis L1of the lens3, a Z direction inFIG. 1and the like) is a vertical direction, the optical axis direction of the lens6(an X direction inFIG. 1and the like) is a front-back direction, and a Y direction inFIG. 1and the like, which is orthogonal to the vertical direction and the front-back direction, is the left-right direction. Moreover, it is assumed that a side in which the lens3is disposed with respect to the optical unit1in the vertical direction (a Z1direction side inFIG. 3and the like) is an “upper” side, and a side opposite thereto (a Z2direction side inFIG. 3and the like) is a “lower” side. Furthermore, it is assumed that a side on which the camera module8is disposed with respect to the prism5in the front-back direction (an X1direction side inFIG. 3and the like) is a “front” side, and a side opposite thereto (an X2direction side inFIG. 3and the like) is a “rear” side.

The holder9is rotatable with respect to the housing10with the front-back direction as the axis direction of rotation. The second rotation mechanism12rotates the holder9with respect to the housing10with the front-back direction as the axis direction of rotation. The prism5and the prism holder15are rotatable with respect to the holder9with a direction orthogonal to the front-back direction and intersecting the vertical direction as the axis direction of rotation. The first rotation mechanism11rotates the prism5and the prism holder15with respect to the holder9with the direction orthogonal to the front-back direction and intersecting the vertical direction as the axis direction of rotation.

The axis directions of rotation of the prism5and the prism holder15with respect to the holder9vary depending on a rotating position of the holder9with respect to the housing10, but it is slightly inclined from the left-right direction or is matched with the left-right direction. In this embodiment, when the holder9is disposed at a predetermined reference position with respect to the housing10, the axis directions of rotation of the prism5and the prism holder15with respect to the holder9are matched with the left-right direction. Moreover, in this embodiment, when the holder9is disposed at the reference position with respect to the housing10, and the prism5is disposed at the predetermined reference position with respect to the holder9, the reflection surface5ais inclined by 45° to the vertical direction when viewed from the left-right direction.

The optical unit1corrects runout of an optical image by performing at least either one of the following operations, that is, a rotating operation of the holder9with respect to the housing10, and a rotating operation of the prism5and the prism holder15with respect to the holder9. In this embodiment, the runout of the optical image in the pitch direction is corrected by the rotating operation of the prism5with respect to the holder9, and the runout of the optical image in the yaw direction is corrected by the rotating operation of the holder9with respect to the housing10.

The camera module8includes a substrate20on which the image pickup element7is mounted. The image pickup element7is mounted on a rear surface of the substrate20. The image pickup element7is disposed on a front side of the lens6. A flexible printed circuit board21is withdrawn from the substrate20. As described above, the lens6is a lens group consisting of a plurality of lenses. The lens6in this embodiment includes a focus lens and a zoom lens. The camera module8includes a focus-lens drive mechanism to drive the focus lens and a zoom-lens drive mechanism to drive the zoom lens. The camera module8does not have to include at least either one of the focus-lens drive mechanism and the zoom-lens drive mechanism.

The holder9is formed of a resin material. An outer shape of the holder9is substantially rectangular, and the holder9is disposed so that a long side direction of the holder9matches the front-back direction when viewed from the vertical direction. The camera module8is fixed to a front side part of the holder9. The prism holder15is rotatably attached to a rear side part of the holder9. A through hole penetrating in the vertical direction is formed on the rear side part of the holder9where the prism holder15is attached. The housing10is formed of a resin material. The housing10is formed having a rectangular frame shape, and the housing10is disposed so that the long side direction of the housing10matches the front-back direction when viewed from the vertical direction. The holder9is disposed on an inner peripheral side of the housing10.

The first rotation mechanism11includes a drive magnet22and a drive coil23opposed to each other in the front-back direction. The drive magnet22is formed having a rectangular flat-plate shape. The drive magnet22is fixed to a rear surface of the prism holder15and is fixed to the prism5through the prism holder15. The drive magnet22is magnetized so that a magnetic pole of an upper half of an opposing surface to the drive coil23of the drive magnet22and a magnetic pole of a lower half of the opposing surface to the drive coil23of the drive magnet22are different from each other. A magnetic plate24formed of a magnetic material is disposed between the drive magnet22and the prism holder15(seeFIG. 5).

The drive coil23is an air-core coil wound in an air-core configuration. The drive coil23is disposed on a rear side of the drive magnet22. The drive coil23is fixed to a rear end portion of the housing10. A coil fixing portion l0awhere the drive coil23is fixed is formed on the rear end portion of the housing10. The coil fixing portion l0ais disposed closer to a front side than the rear end portion of the holder9. On an inner peripheral side of the drive coil23, a magnetic sensor25to detect the position of the prism5with respect to the holder9(specifically, a rotating position of the prism5with respect to the holder9) is disposed. The magnetic sensor25is, for example, a Hall element. The magnetic sensor25is fixed to the coil fixing portion10a.The magnetic sensor25is opposed to the drive magnet22in the front-back direction.

The second rotation mechanism12includes a drive magnet28and a drive coil29opposed to each other in the left-right direction. The drive magnet28is formed having a rectangular flat-plate shape. The drive magnet28is fixed to one of side surfaces of the holder9in the left-right direction. Moreover, the drive magnet28is fixed to the front side part of the holder9. The drive magnet28is magnetized so that the magnetic pole of the upper half of the opposing surface to the drive coil29of the drive magnet28and the magnetic pole of the lower half of the opposing surface to the drive coil29of the drive magnet28are different from each other. A magnetic plate (not shown) formed of a magnetic material is disposed between the drive magnet28and the holder9.

The drive coil29is an air-core coil wound in the air-core configuration. The drive coil29is disposed outside the drive magnet28in the left-right direction. The drive coil29is fixed to the front side part of the housing10. Moreover, the drive coil29is fixed to the inner side of one of the side surface portions in the left-right direction of the housing10. On the inner peripheral side of the drive coil29, a magnetic sensor30to detect the position of the holder9with respect to the housing10(specifically, the rotating position of the holder9with respect to the housing10) is disposed (seeFIG. 1). The magnetic sensor30is configured in the same way as the magnetic sensor25. The magnetic sensor30is fixed to the housing10. The magnetic sensor30is opposed to the drive magnet28in the left-right direction.

The rotating shaft portion16has a ball fixing plate32made of metal and fixed to the prism holder15, a ball33made of metal and fixed to the ball fixing plate32, and a plate spring34made of metal and biasing the ball33. As shown inFIG. 6, the ball fixing plates32are fixed to both side surfaces in the left-right direction of the prism holder15, and the balls33are disposed on both sides in the left-right direction of the prism holder15. The ball33is fixed to the ball fixing plate32by welding. The plate springs34are disposed on both sides of the ball33in the left-right direction and bias the ball33inwardly in the left-right direction.

The plate spring34includes a held portion34aheld in the holder9and a spring portion34bthat is elastically deformable in the left-right direction with respect to the held portion34a.The spring portion34bbiases the ball33from outside in the left-right direction. The spring portion34bhas a concave-curved receiving surface with which the ball33is brought into contact formed. At an upper end of the spring portion34b,a retaining portion34cis formed to prevent the ball33from being removed out to the upper side. The retaining portion34cprotrudes inwardly in the left-right direction.

The prism5and the prism holder15are rotated with respect to the holder9with a line passing through centers of two balls33disposed on the both sides of the prism holder15in the left-right direction (a line connecting the centers of the two balls33) as the rotation center. That is, the line passing through the centers of the two balls33is an axis (rotation center line) L11of rotation of the prism5with respect to the holder9. The axis L11passes near the center of the reflection surface5awhen viewed from an axis direction of the axis L11.

The rotating shaft portion17has a ball fixing plate36made of metal and fixed to the holder9, a ball37made of metal and fixed to the ball fixing plate36, and a plate spring38made of metal and biasing the ball37. As shown inFIG. 5, the ball fixing plates36are fixed to both side surfaces in the front-back direction of the holder9, and the balls37are disposed on both sides in the front-back direction of the holder9. The ball37is fixed to the ball fixing plate36by welding. The plate springs38are disposed on both sides of the ball37in the front-back direction and bias the ball37inwardly in the front-back direction. The ball fixing plate36, the ball37, and the plate spring38disposed on the rear side of the holder9are disposed on the rear side of the coil fixing part10a.

The plate spring38includes a held portion38aheld in the housing10and a spring portion38bthat is elastically deformable in the front-back direction with respect to the held portion38a.The spring portion38bbiases the ball37from outside in the front-back direction. The spring portion38bhas a concave-curved receiving surface with which the ball37is brought into contact formed. At an upper end of the spring portion38b,a retaining portion38cis formed to prevent the ball37from being removed out to the upper side. The retaining portion38cprotrudes inwardly in the front-back direction.

The holder9rotates with respect to the housing10with a line passing through the centers of two balls37disposed on the both sides in the front-back direction of the holder9(a line connecting the centers of the two balls37) as the center of rotation. That is, the line passing through the centers of the two balls37is an axis (rotation center line) L12of rotation of the holder9with respect to the housing10. The axis L12of this embodiment is matched with the optical axis L2of the lens6. The axis L11and the axis L12intersect at an intersection of the optical axis L1and the optical axis L2. In other words, the optical axis L1, the axis L11, and the axis L12intersect at a single point.

In addition, the axis L12passes through the center of gravity of a movable body40which can be rotated with respect to the housing10with the front-back direction as the axis direction. The movable body40is constituted by all members that are rotatable with respect to the housing10. The movable body40in this embodiment is constituted by the prism5, the camera module8, the holder9, the first rotation mechanism11, the prism holder15, the rotating shaft portion16, the drive magnet28, the ball fixing plate36, and the ball37.

In addition, the drive magnet22, the drive coil23, and the magnetic sensor25are disposed on the axis L12. Specifically, the center of the drive coil23and the center of the magnetic sensor25are disposed on the axis L12. Moreover, when the prism5is disposed at the reference position with respect to the holder9, the center of the drive magnet22is disposed on the axis L12. That is, when the prism5is disposed at the reference position with respect to the holder9, the center of the drive magnet22, the center of the drive coil23, and the center of the magnetic sensor25are disposed on the axis L12.

Main Effect of this Embodiment

As described above, in this embodiment, the holder9holds the camera module8having the image pickup element7and also rotatably holds the prism5. Moreover, in this embodiment, the second rotation mechanism12rotates the holder9with respect to the housing10with the optical axis direction (front-back direction) of the lens6as the axis direction of rotation and performs runout correction in the yaw direction by rotating the prism5held in the holder9with the optical axis direction of the lens6as the axis direction of rotation. Furthermore, in this embodiment, when the holder9is rotated to perform the runout correction in the yaw direction, the image pickup element7held in the holder9rotates together with the prism5with the optical axis direction of the lens6as the axis direction of rotation, and the optical system of the optical unit1does not collapse. Therefore, in this embodiment, inclination of the image acquired by the image pickup element7can be prevented even when the runout correction in the yaw direction is performed.

In this embodiment, the axis L12of rotation of the holder9with respect to the housing10matches with the optical axis L2of the lens6. Thus, in this embodiment, more appropriate runout correction in the yaw direction can be performed by rotating the holder9with respect to the housing10. Moreover, in this embodiment, since the axis L12passes through the center of gravity of the movable body40which is rotatable with respect to the housing10with the front-back direction as the axis direction, the second rotation mechanism12enables smooth rotation of the movable body40with respect to the housing10.

In this embodiment, the drive magnet22and the drive coil23are disposed on the axis L12. Therefore, in this embodiment, even in a state where the holder9is rotated with respect to the housing10(that is, even when the runout correction in the yaw direction is being performed), the misalignment between the drive magnet22fixed to the prism holder15and the drive coil23fixed to the housing10can be suppressed. Therefore, in this embodiment, even in a state where the runout correction in the yaw direction is being performed, the runout correction in the pitch direction can be properly performed.

Particularly in this embodiment, the center of the drive magnet22and the center of the drive coil23are disposed on the axis L12when the prism5is disposed at the reference position with respect to the holder9and thus, even in a state where the holder9is rotated with respect to the housing10, misalignment between the drive magnet22and the drive coil23can be effectively suppressed. Therefore, in this embodiment, even in a state where the runout correction in the yaw direction is being performed, the runout correction in the pitch direction can be performed more properly.

In this embodiment, the magnetic sensor25is disposed on the axis L12. Therefore, in this embodiment, even in a state where the holder9is rotated with respect to the housing10(that is, even when the runout correction in the yaw direction is being performed), the misalignment between the drive magnet22fixed to the prism holder15and the magnetic sensor25fixed to the housing10can be suppressed. Therefore, in this embodiment, even in the state where the runout correction in the yaw direction is being performed, the position of the prism5with respect to the holder9in the pitch direction can be properly detected.

Particularly in this embodiment, since the center of the magnetic sensor25is disposed on the axis L12, even in a state where the holder9is rotated with respect to the housing10, misalignment between the drive magnet22and the magnetic sensor25can be effectively suppressed. Therefore, in this embodiment, in the state where the runout correction in the yaw direction is being performed, the position of the prism5with respect to the holder9in the pitch direction can be properly detected.

Other Embodiments

The embodiment described above is an example of a preferred embodiment of the present invention but it is not limiting, and various modifications can be implemented within a range not changing the gist of at least an embodiment of the present invention.

In the above-described embodiment, the axis L12does not have to pass through the center of gravity of the movable body40. Moreover, in the above-described embodiment, the axis L12and the optical axis L2do not have to match each other. Furthermore, in the above-described embodiment, the center of the drive coil23may be displaced from the axis L12, and the center of the magnetic sensor25may be displaced from the axis L12. Furthermore, when the prism5is disposed at the reference position with respect to the holder9, the center of the drive magnet22may be displaced from the axis L12.

In the above-described embodiment, the drive coil23may be fixed to the rear end portion of the holder9. Moreover, in the above-described embodiment, the drive magnet22may be fixed to the housing10or the holder9, and the drive coil23and the magnetic sensor25may be fixed to the prism holder15. In this case, for example, the center of the drive magnet22is disposed on the axis L12, and the center of the drive coil23and the center of the magnetic sensor25are disposed on the axis L12when the prism5is disposed at the reference position with respect to the holder9. Moreover, in the above-described embodiment, the drive magnet28may be fixed to the housing10, and the drive coil23and the magnetic sensor25may be fixed to the holder9.

In the above-described embodiment, the drive magnet28and the drive coil29may be opposed to each other in the front-back direction. In this case, for example, the drive magnet28is fixed to both end sides in the left-right direction of the rear end portion of the holder9, and the drive coil29is fixed to both end sides in the left-right direction of the rear end portion of the housing10. Moreover, in this case, for example, the drive magnet28is fixed to both end sides in the left-right direction of a front end portion of the holder9, and the drive coil29is fixed to both end sides in the left-right direction of a front end portion of the housing10.

In the above-described embodiment, the first rotation mechanism11may include a shape-memory alloy instead of the drive magnet22and the drive coil23. The first rotation mechanism11may include a motor and a power transmission mechanism that transmits power of the motor to the prism holder15instead of the drive magnet22and the drive coil23. Similarly, in the above-described embodiment, the second rotation mechanism12may include a shape-memory alloy or may include a motor and a power transmission mechanism that transmits the power of the motor to the holder9instead of the drive magnet28and the drive coil29.

In the above-described embodiment, the rotating shaft portion16may be constituted by, for example, a fixed shaft formed or fixed on the prism holder15and a bearing that holds the fixed shaft rotatably. Similarly, in the above-described embodiment, the rotating shaft portion17may be constituted by, for example, a fixed shaft formed or fixed in the holder9and a bearing that holds the fixed shaft rotatably.

In the above-described embodiment, the holder9is constituted by a single member, but the holder9may be constituted by two or more members. Similarly, in the above-described embodiment, the housing10is constituted by a single member, but the housing10may be constituted by two or more members. Moreover, in the above-described embodiment, the optical unit1may include a reflective mirror in which a reflection surface to reflect light incident from the outside is formed instead of the prism5.