JPH1117999A - Image pickup unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a driving mechanism of an image pickup unit including an image pickup optical system and a solid-state image pickup device simple small-sized and light weight in the image pickup unit capable of automatically tracking a target. SOLUTION: An image pickup optical system 11 and an image pickup element 12 are stored inside the approximately spherical image pickup unit 10 and the image pickup unit 10 is freely rotatably held by a ball 26 provided between a spherical space 24 of a case 20 and an outer surface 15 of the image pickup unit 10. A one-dimensional piezoelectric actuator with two arms 31a and 31b which are symmetrically formed centering around a friction member 32 is provided in a recessed part of the spherical space 24, the friction member 32 is driven in an elliptic orbit and the whole of the image pickup unit 10 is rotated in a specified direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus capable of automatically tracking a target, that is, a so-called robot eye.

[0002]

2. Description of the Related Art FIG. 11 shows a configuration of a conventional image pickup apparatus using a gimbal. An image pickup optical system and an image pickup device (not shown) such as a CCD are housed inside a substantially cylindrical image pickup unit 100. The imaging device is connected to the control unit 130 via the cable K1. Imaging unit 1
00 is supported by a rotating frame 102 by a shaft 101 and is rotatable around the Y axis. The rotating frame 102 is supported by a fixed frame 104 by a shaft 103 and is rotatable around the X axis. The X axis is almost horizontal and immobile. On the other hand, the Y axis rotates in a plane orthogonal to the X axis.

[0003] A gear 112 is fixed to the shaft 101 and meshes with a gear 111 fixed to the rotating shaft of a motor 113. The Y-axis drive mechanism 110 is composed of gears 111 and 112, a motor 113, an encoder (not shown), and the like.
1 controls the rotation amount and rotation direction. The motor 113 and the encoder are connected to the control unit 130 via a cable K2 or the like.

Similarly, a gear 122 is fixed to the shaft 103 and meshes with a gear 121 fixed to the rotation shaft of a motor 123. The X-axis drive mechanism 120 is configured by the gears 121 and 122, the motor 123, the encoder (not shown), and the like, and controls the rotation amount and the rotation direction of the shaft 103. Motor 12
3 and the encoder are connected to the control unit 130 via a cable K3 or the like.

[0005] When automatically tracking the target, the control unit 130 processes the image captured by the imaging unit 100 and separates and extracts the image of the target. Then, an amount of movement required to move the image of the target to the center of the screen is calculated. Further, based on the calculation result, the motor 11
By driving 3 and 123, the optical axis of the imaging optical system of the imaging unit 100 is directed toward the target.

[0006]

In the configuration of the conventional image pickup apparatus, at least the Y-axis drive mechanism 110 needs to be provided integrally with the rotating frame 102 or inside the image pickup unit 100. Therefore, the X-axis drive unit 12
In the case of No. 0, not only the imaging unit 100 and the rotating frame 102 but also the Y-axis drive mechanism 110 must be driven together, and there is a problem that the load becomes larger than that of the Y-axis drive mechanism 110.

Further, it requires space for cables K1, K2, etc., connecting the movable parts such as the imaging unit 100 and the Y-axis drive mechanism 110 to the control unit 130, and it is difficult to reduce the size and weight of the entire apparatus. Had a problem.

Further, when taking measures such as dust proofing, moisture proofing and waterproofing, not only the imaging unit 100 but also the Y-axis driving mechanism 11
It is necessary to house the entire apparatus including the 0 and X-axis drive mechanisms 120 in a special housing, which has a problem that the configuration of the apparatus is complicated and large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide an imaging apparatus which is simple in structure, small in size and light in weight, and can be driven with a small driving force. I have.

[0010]

To achieve the above object, a first image pickup apparatus of the present invention has at least an image pickup optical system and an image pickup element housed therein, and at least a part of an outer surface thereof has a convex spherical surface. A unit, a holding member that holds the imaging unit so as to be able to rotate around an arbitrary axis, and a friction member that is provided on two axes passing through the center of the sphere forming the convex spherical surface and orthogonal to each other and pressed by the convex spherical surface And a two-dimensional drive mechanism for applying a turning force in two directions to the imaging unit.

According to the first image pickup apparatus, the convex spherical surface on the outer surface of the image pickup unit held by the holding member so as to be rotatable around an arbitrary axis is pressed by the two friction members.
Each friction member is moved in a predetermined direction by using a two-dimensional piezoelectric actuator. With the movement of the friction member, the imaging unit rotates in two planes passing through the center of the sphere and including each one-dimensional piezoelectric actuator.
By controlling the direction and amount of movement of the friction member by each one-dimensional actuator, the imaging unit rotates in a predetermined direction. Since the imaging unit, which is a movable part, is not provided with a drive mechanism such as a motor or a gear, the imaging unit itself is small and lightweight. Further, a cable for controlling the drive mechanism is not required. Furthermore, since the imaging unit is small and lightweight, the driving force of the one-dimensional piezoelectric actuator required to rotate the imaging unit on its own axis is reduced, and the driving mechanism itself is also reduced. As a result, an imaging device having a simple structure, small size and light weight, and drivable with a small driving force can be obtained.

In the above configuration, the one-dimensional piezoelectric actuator has two arms that are substantially symmetrical about the friction member, includes the two arms, and is in contact with the convex spherical surface of the imaging unit of the friction member. It is preferable that the cross section perpendicular to the cross-section is substantially in the shape of a "<", and the layers are stacked in the direction perpendicular to the cross section. That is, by applying two sinusoidal voltages having a phase difference to the two arm portions of the one-dimensional actuator, respectively, the first arm is extended and the second arm is contracted, and the first and second arms are contracted. , The state where the first arm contracts and the second arm expands, and the state where both the first and second arms contract. As a result, the friction member is driven to draw an elliptical orbit, and the outer surface of the imaging unit is turned in a predetermined direction accordingly. In addition, since the one-dimensional piezoelectric actuators are stacked in a direction orthogonal to the substantially “C” -shaped cross section, the shape such as the angle of the two arms of the substantially “C” shape is stabilized.

A second image pickup apparatus according to the present invention houses at least an image pickup optical system and an image pickup element therein, and forms an image pickup unit having at least a part of an outer surface thereof a convex spherical surface, and forms the image pickup unit into a convex spherical surface. A holding member for rotatably holding around an arbitrary axis passing through the center of the sphere, a friction member provided on one axis passing through the center of the sphere and pressed by a convex spherical surface, and a two-dimensional piezoelectric for driving the friction member A set of drive mechanisms that includes an actuator and applies a turning force in two directions to the imaging unit.

According to the second imaging apparatus, the convex spherical surface on the outer surface of the imaging unit held by the holding member so as to be rotatable around an arbitrary axis passing through the center of the sphere is pressed by one friction member. The friction member is moved in a two-dimensional direction using two two-dimensional piezoelectric actuators. With the movement of the friction member, the imaging unit rotates in an arbitrary plane including the center of the sphere and the two-dimensional piezoelectric actuator. By controlling the direction and amount of movement of the friction member by the two-dimensional actuator, the imaging unit rotates in a predetermined direction.
Further, as compared with the first imaging device, the configuration of the piezoelectric actuator is complicated, but the number of the piezoelectric actuators can be reduced to one, and a smaller and lighter imaging device can be obtained.

In the above configuration, the two-dimensional piezoelectric actuator has four arms provided at approximately 90 degrees around the friction member, and two arms that are not adjacent to each other among the four arms.
It is preferable that the sections including the book and orthogonal to the surface of the friction member that comes into contact with the convex spherical surface of the imaging unit have a substantially “<” shape, and are stacked in the direction orthogonal to the respective sections. That is, of the four arms of the two-dimensional actuator, a pair of first and third arm portions
By applying two sinusoidal voltages having a phase difference, the first arm is extended, the third arm is contracted, the first and third arms are both extended, the first arm is contracted, and the third arm is contracted. Is repeated, and the first and third arms are both contracted. As a result, on the surface including the first and third arm portions, the friction member is driven so as to draw an elliptical orbit. Similarly, by applying two sinusoidal voltages having a phase difference to the pair of the second and fourth arms, respectively, of the four arms of the two-dimensional actuator, the second arm extends. The state where the fourth arm contracts, the state where both the second and fourth arms extend, the state where the second arm contracts and the fourth arm expands, and the state where both the second and fourth arms contract are repeated. As a result, on the surface including the second and fourth arm portions, the friction member is driven so as to follow an elliptical orbit. Since the timing of these two movements can be arbitrarily controlled, the friction member can be moved in an arbitrary two-dimensional direction, and accordingly, the outer surface of the imaging unit is turned in an arbitrary direction. Also, of the four arms of the two-dimensional piezoelectric actuator, the first and third arm portions and the second and fourth arm portions are respectively integrated, and are respectively orthogonal to the substantially “<”-shaped cross sections. Since the two arms are stacked in the directions, the shapes such as the angle of the two arms in a substantially “U” shape are stabilized.

In each of the above configurations, it is preferable that the center of gravity of the imaging unit substantially coincides with the center of the sphere. As described above, the imaging unit is rotated by the piezoelectric actuator. Therefore, in order to smoothly rotate the imaging unit with a small driving force, it is preferable that the center of gravity does not move.
In order to make the center of gravity of the imaging unit substantially coincide with the center of the sphere, specifically, a balance weight or the like may be provided inside the imaging unit.

In the above configuration, the imaging unit is housed in a housing, and the housing has at least a concave spherical surface opposed to a convex spherical surface of the imaging unit, and an opening for imaging an object by an imaging optical system. It is preferable to have
With such a configuration, the convex spherical surface on the outer surface of the imaging unit is held by the concave spherical surface having substantially the same diameter, so that a spherical bearing is substantially formed. As a result, the substantially spherical imaging unit can rotate around an arbitrary axis passing through the center of the sphere.

Further, in the above configuration, it is preferable that a ball is provided between the convex spherical surface on the outer surface of the imaging unit and the concave spherical surface of the housing, and the friction member protrudes from the concave spherical surface. That is, by configuring a so-called ball bearing, the load when the imaging unit rotates on its axis becomes extremely small, and the imaging unit can easily follow the movement of the friction member driven by the piezoelectric actuator. Also, the play of the gap between the imaging unit and the ball is absorbed by the elasticity of the friction member.

In the above configuration, it is preferable that a seal member is provided in a gap between the opening of the housing and the imaging optical system of the imaging unit. Alternatively, in the above structure, the opening of the housing is preferably sealed by a transparent member. With such a configuration, the imaging unit can be substantially hermetically sealed inside the housing, and a dustproof, moistureproof, or waterproof effect can be obtained without using a special housing.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the imaging apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view illustrating a configuration of an imaging device according to the first embodiment in an initial state, and FIG. 2 illustrates an operation state thereof. FIG. 3 is a perspective view showing a configuration of a drive system of the imaging unit. Note that the imaging device of the present invention has substantially the same configuration even in a cross section perpendicular to the paper plane passing through the axis AA.

As shown in FIGS. 1 to 3, the image pickup unit 1
In the case of 0, at least a part of the outer surface 15 is a spherical surface. As shown in FIGS. 1 and 2, the imaging unit 10
Inside, an imaging optical system 11, a solid-state imaging device 12, such as a CCD,
A balance weight 14 and the like are provided.

The housing 20 is composed of two parts 21 and 22, and has a substantially spherical space 2 for accommodating the imaging unit 10.
4 An opening 23 is formed on the front surface of the housing 20, and the imaging optical system 11 of the imaging unit 10 is formed through the opening 23.
Part protrudes outside. Further, a driving mechanism 3 is provided on a ceiling portion and a side surface (not shown) of the space 24 of the housing 20.
A concave portion 25 for accommodating 0 is formed. The drive mechanism 30 includes a one-dimensional piezoelectric actuator 31 and a friction member 32 provided substantially at the center thereof. The friction member 32 projects from the concave spherical surface of the space 24 and is pressed against the convex spherical surface of the outer surface 15 of the imaging unit 10.

A plurality of balls 26 are provided between the concave spherical surface of the space 24 and the convex spherical surface of the outer surface 15 of the imaging unit 10, and rotate the imaging unit 10 about an arbitrary axis passing through the center O of the sphere. It is freely held. Here, ball 26
Constitutes a so-called ball bearing, the convex spherical surface of the outer surface 15 of the imaging unit 10 and the ball 26 are in point contact with each other, and when the imaging unit 10 rotates, only rolling friction acts between them. Therefore, the imaging unit 10
Can be rotated with a very small force.

As shown in FIGS. 1 to 3, a predetermined position (for example, on a first surface (a surface parallel to the paper surface) including the axes AA and BB) inside the housing 20. , At the bottom)
An encoder 27 having a rotation axis perpendicular to the plane is provided, and detects the rotation angle (rotation amount) of the imaging unit 10 on the first plane. Similarly, inside the housing 20,
Also, at a predetermined position (for example, a side) on the second surface including the axes AA and CC (see FIG. 3), the encoder 27 having the axis perpendicular to the second surface as the rotation axis. Is provided,
The rotation angle (rotation amount) of the imaging unit 10 on the second surface is detected. The detection signals of these two encoders 27 are input to the control unit 50 (see FIG. 7), and the direction of the optical axis of the imaging optical system 11 of the imaging unit 10 is calculated.

Next, the details of the driving mechanism 30 will be described with reference to FIG.
This will be described with reference to FIGS. As shown in FIG. 4A, the one-dimensional piezoelectric actuator 31 has a first arm 31a and a second arm 31b formed symmetrically with respect to the friction member 32, and an imaging unit for the friction member 32. 10
The cross-section substantially perpendicular to the surface 32a that contacts the outer surface 15 of the main body has a substantially “C” shape (or herringbone).
Shape). Further, as shown in FIG. 4B, the one-dimensional actuator 31 includes the first and second partial electrodes 34a and 34b and the piezoelectric plate 33 in a direction (Y direction) orthogonal to the substantially “C” -shaped cross section. , Common electrode 35 in this order.

Between the common electrode 35 and the first partial electrode 34a of the first arm 31a, and between the common electrode 35 and the second arm 31b.
For example, two sine-wave voltages having a phase difference as shown in FIG. 5 are applied to the second partial electrode 34b. When the piezoelectric plate 33 extends in the electric field direction (Y direction), it contracts in a direction (X direction) orthogonal to the electric field. The reverse is also true. The one-dimensional piezoelectric actuator 31 uses the displacement in the X direction to drive the friction member 32 and the imaging unit 10 against which the friction member 31 is pressed.

The sine wave voltage W1 shown in FIG.
It is assumed that a sine wave voltage W2 is applied to the second arm 31b at a. At time t1, as shown in FIG.
Arm 31a extends, and second arm 31b contracts. At time t2, as shown in FIG. 6B, the first and second arms 31a
And 31b extend together. At time t3, as shown in FIG. 6C, the first arm 31a contracts, and the second arm 31b extends. At time t4, as shown in FIG.
Arm 31a and second arm 31b both contract. as a result,
The friction member 32 is driven to draw an elliptical orbit. Accordingly, the outer surface 15 of the imaging unit 10 is
(B) The vehicle is turned in the direction indicated by the middle arrow D.

Since this operation is performed independently for each of the two sets of drive mechanisms 30, the image pickup unit 10
The optical axis L of the imaging optical system 11 can be directed in a predetermined direction, and an image in a desired direction can be captured. In order to move the imaging unit 10 in the opposite direction, the phase shift between the sine wave voltages W1 and W2 may be reversed and applied to the first and second arms 31a and 31b.

Next, the block configuration of the control unit 50 is shown in FIG. The hardware of the control unit 50 includes a microcomputer, a memory, and the like (known and not shown).
It is composed of On the other hand, the control unit 50 functionally performs A / D conversion on an image signal (analog signal) from the solid-state imaging device 12 and performs A / D conversion on the image capturing unit 51 for capturing the image signal into the control unit 50. Storage means 52 for storing image data stored therein, and image storage means 52
D / A conversion of the image data stored in
An image display unit 53 which converts the image into a TSC signal or the like and outputs it to a monitor TV or the like (not shown) and an image stored in the image storage unit 52 when automatically tracking a moving target such as a person. An image evaluation unit 54 that processes and separates and extracts the image of the target object from the previous image, for example, and a focus that detects the focal length of the lens when the imaging optical system 11 of the imaging unit 10 is a zoom lens. Based on the distance detection means, the image data of the target separated and extracted by the image evaluation means 54, and the focal length data of the imaging optical system 11 detected by the focal length detection means 55, the image of the target is positioned at the center of the screen. Driving amount calculating means 56 for calculating a driving amount necessary for moving, for example, a frequency of a sine wave voltage, a phase shift amount, a phase shift direction, and the like shown in FIG. Two drive mechanisms 30 on the basis of the more detection signals from the computed driving amount and an encoder 27
A drive control unit 57 for controlling the (one-dimensional piezoelectric actuator 31), a line-of-sight operating unit 58 for manually controlling the line of sight of the imaging unit 10, that is, the direction of the optical axis L of the imaging optical system 11, while watching the monitor TV, and the like. including.

When the image pickup apparatus of the present invention is arranged in an environment with a lot of dust, an environment with a high humidity, an environment that is easily wet with water, or the like, the space between the opening 23 of the housing 20 and the outer surface 15 of the image pickup unit 10 can be obtained. , A seal member (not shown) such as an O-ring may be provided. This makes it possible to easily obtain a dust-proof, moisture-proof or waterproof effect without using a special case. The imaging optical system 11 of the imaging unit 10
Needless to say, the part is sealed.

(Second Embodiment) A second embodiment of the imaging apparatus according to the present invention will be described with reference to FIGS. In the first embodiment, two sets of drive mechanisms 30 each including a one-dimensional piezoelectric actuator 31 are used. However, in the second embodiment, one set including a two-dimensional piezoelectric actuator 41 is used.
A set of drive mechanisms 40 is used. FIG. 8 shows a configuration of an imaging device according to the second embodiment in an initial state. Less than,
Only differences from the first embodiment will be described.

The recess 25 for accommodating the drive mechanism 40
Is provided at a position behind the substantially spherical space 24 of the housing 20 (at a position facing the opening 23). Drive mechanism 40
Is composed of a two-dimensional piezoelectric actuator 41 and a friction member 42 provided substantially at the center thereof. FIG.
As shown in (b), the two-dimensional piezoelectric actuator 41
Has first to fourth arms 41a to 41d provided approximately every 90 degrees around the friction member 42. FIG.
As shown in (a), of the four arms, the first arm 41a and the third arm 14c and the second arm 41b and the fourth arm 41d which are not adjacent to each other are symmetric about the friction member 42, respectively. And the outer surface 1 of the imaging unit 10 of the friction member 42
The cross-sections substantially perpendicular to the surface 42a in contact with 5 are each formed substantially in the shape of "". Furthermore, first to fourth
The arms 41a to 41d are laminated in the order of the first to fourth partial electrodes 44a to 44b, the piezoelectric plate 43, and the common electrode 45, respectively.

Between the common electrode 45 and the first partial electrode 34a of the first arm 41a, and between the common electrode 45 and the third arm 41c.
When two sinusoidal voltages having a phase difference as shown in FIG. 5 are respectively applied between the third partial electrode 44c and the third partial electrode 44c,
A state in which the first arm 41a is extended and the third arm 41c is contracted,
And a state where the third arms 41a and 41c are both extended,
The arm 41a contracts and the third arm 41c extends, and the first and third arms 41a and 41c both contract. As a result, on the plane including the first and third arms 41a and 41c, the friction member 42 is driven to draw an elliptical orbit. Similarly, by applying two sine-wave voltages having a phase difference to the pair of the second and fourth arms 41b and 42d of the four arms of the two-dimensional actuator, respectively, Arm 41b extends and the fourth arm 41
d is contracted, the second and fourth arms 41b and 41d are both extended, the second arm 41b is contracted, the fourth arm 41d is extended, and the second and fourth arms 41b and 41d are both contracted. repeat. As a result, the second and fourth arms 41
In the plane including the portions b and 41d, the friction member 42 is driven to draw an elliptical orbit. Since the timing of these two movements can be arbitrarily controlled, the friction member 42 can be moved in an arbitrary two-dimensional direction, and accordingly, the outer surface of the imaging unit 10 is turned in an arbitrary direction.

(Third Embodiment) FIG. 10 shows the configuration of a third embodiment of the imaging apparatus according to the present invention. In the imaging device according to the third embodiment, the front surface of the opening 23 of the housing 20 of the imaging device according to the second embodiment is sealed with a transparent member 28. Note that the other configuration is substantially the same as that shown in FIG. In this case, case 2
0 and the transparent member 28 substantially constitute a closed housing. Therefore, the portion of the imaging optical system 11 of the imaging unit 10 does not necessarily need to be sealed. The first
Needless to say, the same effect can be obtained even if the front surface of the opening 23 of the housing 20 of the imaging device according to the embodiment is sealed with the transparent member 28.

[0035]

As described above, the first image pickup apparatus of the present invention has at least an image pickup optical system and an image pickup element housed therein, and at least a part of the outer surface thereof has a convex spherical surface. A holding member that rotatably holds around an arbitrary axis, and a friction member and a friction member that are provided on two axes passing through the center of the sphere forming the convex spherical surface and orthogonal to each other, and pressed by the convex spherical surface. Since it includes a one-dimensional piezoelectric actuator and two sets of drive mechanisms for applying a turning force in two directions to the image pickup unit, the convex spherical surface on the outer surface of the image pickup unit is pressed by two friction members, and two one-dimensional By moving each friction member in a predetermined direction using a piezoelectric actuator, the imaging unit passes through the center of the sphere and includes each one-dimensional piezoelectric actuator. One of it is possible to pivot in a plane. Since the imaging unit, which is a movable portion, is not provided with a drive mechanism such as a motor or a gear, the imaging unit itself can be reduced in size and weight. Further, a cable for controlling the drive mechanism is not required. Further, since the imaging unit is small and lightweight, the driving force of the one-dimensional piezoelectric actuator required for rotating the imaging unit on its own axis is reduced, and the driving mechanism itself can be reduced. As a result, it is possible to obtain an imaging device which has a simple structure, is small and lightweight, and can be driven with a small driving force.

As a one-dimensional piezoelectric actuator,
The first arm is provided by providing two symmetrical arms having a substantially “C” shape around the friction member and applying two sine wave voltages having a phase difference to the two arm portions, respectively. A state in which the second arm extends and contracts, a state in which the first and second arms extend together, a state in which the first arm contracts and the second arm extends, and a state in which the first and second arms contract together are repeated. it can. As a result, the friction member is driven to draw an elliptical orbit, and accordingly, the outer surface of the imaging unit can be turned in a predetermined direction. In addition, by stacking the one-dimensional piezoelectric actuators in a direction perpendicular to the substantially “C” -shaped cross section, the shape such as the angle of the two arms in the substantially “C” shape can be stabilized.

In the second imaging apparatus of the present invention, at least an imaging optical system and an imaging element are housed inside, and at least a part of the outer surface of the imaging unit has a convex spherical surface, and the imaging unit forms a convex spherical surface. A holding member for rotatably holding around an arbitrary axis passing through the center of the sphere, a friction member provided on one axis passing through the center of the sphere and pressed by a convex spherical surface, and a two-dimensional piezoelectric for driving the friction member Since the actuator includes an actuator and a set of driving mechanisms for applying a turning force in two directions to the imaging unit, the convex spherical surface on the outer surface of the imaging unit is pressed by one friction member, and one two-dimensional piezoelectric actuator is formed. By moving the friction member in the two-dimensional direction, the imaging unit can be turned in any plane including the center of the sphere and the two-dimensional piezoelectric actuator. Further, the structure of the piezoelectric actuator is more complicated than that of the first imaging apparatus, but the number of the piezoelectric actuator is one.
And a smaller and lighter imaging device can be obtained.

As a two-dimensional piezoelectric actuator,
By providing four arms provided approximately every 90 degrees around the friction member and applying two sine wave voltages having a phase difference to a pair of the first and third arms, the first arm is provided. And the friction member can be driven to draw an elliptical trajectory on a surface including the third arm portion. Similarly, by applying two sinusoidal voltages having a phase difference to the pair of second and fourth arm portions, respectively, the second and fourth arm portions are applied.
The friction member can be driven to draw an elliptical orbit on a surface including the arm portion of the arm. Since the timings of these two movements can be arbitrarily controlled, the friction member can be moved in an arbitrary two-dimensional direction, and accordingly, the imaging unit can be turned in an arbitrary direction.

Further, by setting the center of gravity of the image pickup unit to substantially coincide with the center of the sphere, the image pickup unit can rotate smoothly with a small driving force.

Further, the imaging unit is housed inside the housing, and the housing has a concave spherical surface facing the convex spherical surface of the imaging unit;
By providing at least the opening for imaging the subject by the imaging optical system, the convex spherical surface on the outer surface of the imaging unit is held by the concave spherical surface having substantially the same diameter, and a substantially spherical bearing can be formed. As a result, the substantially spherical imaging unit can be rotated around an arbitrary axis passing through the center of the sphere.

Further, by providing a ball between the convex spherical surface on the outer surface of the image pickup unit and the concave spherical surface of the housing, a so-called ball bearing can be formed, and the load when rotating the image pickup unit is extremely reduced. be able to. Further, the imaging unit can easily follow the movement of the friction member driven by the piezoelectric actuator. Further, by projecting the friction member from the concave spherical surface of the housing, the play of the gap between the imaging unit and the holding member can be absorbed by the elasticity of the friction member.

Further, by providing a seal member in a gap between the opening of the housing and the imaging optical system of the imaging unit, or by sealing the opening of the housing with a transparent member, the imaging unit can be mounted on the housing. The inside can be substantially sealed, and a dustproof, moistureproof or waterproof effect can be obtained without using a special housing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an initial state of an imaging device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a driving state of the imaging device illustrated in FIG.

FIG. 3 is a perspective view illustrating a configuration of a drive system of the imaging unit according to the first embodiment.

FIG. 4A is a front view illustrating a configuration of a drive mechanism according to the first embodiment, and FIG. 4B is a plan view thereof.

FIG. 5 is a diagram showing two sinusoidal voltages having a phase difference for driving a piezoelectric actuator common to the embodiments of the present invention.

FIGS. 6A to 6D are diagrams illustrating a series of operations of the drive mechanism according to the first embodiment.

FIG. 7 is a block diagram illustrating a configuration example of a control unit according to the first embodiment.

FIG. 8 is a cross-sectional view illustrating an initial state of an imaging device according to a second embodiment of the present invention.

FIG. 9A is a front view illustrating a configuration of a drive mechanism according to a second embodiment, and FIG. 9B is a plan view thereof.

FIG. 10 is a cross-sectional view illustrating an initial state of an imaging device according to a third embodiment of the present invention.

FIG. 11 is a perspective view showing a configuration of a conventional imaging device.

[Explanation of symbols]

 Reference Signs List 10: imaging unit 11: imaging optical system 12: solid-state imaging device 14: balance weight 15: outer surface (of imaging unit) 20: housing 23: opening 24: substantially spherical space 25: recess 26: ball 27: encoder 28 : Transparent member 30: Driving mechanism 31: One-dimensional actuator 32: Friction member 40: Driving mechanism 41: Two-dimensional actuator 42: Friction member 50: Control unit

Claims (9)

[Claims] 1. An image pickup unit which houses at least an image pickup optical system and an image pickup device, and at least a part of an outer surface of the image pickup unit is a convex spherical surface, and an arbitrary axis passing through the center of a sphere forming the convex spherical surface. A holding member that is rotatably held around, a friction member that is provided on two axes passing through the center of the sphere and that are orthogonal to each other, and is pressed by the convex spherical surface, and a one-dimensional piezoelectric actuator that drives the friction member. An imaging apparatus comprising: two sets of driving mechanisms for applying a turning force in two directions to the imaging unit. 2. The two-dimensional piezoelectric actuator according to claim 1, wherein the one-dimensional piezoelectric actuator has two substantially symmetric arms around the friction member.
A cross section orthogonal to a surface of the friction member, which is in contact with the convex spherical surface of the imaging unit, has a substantially 「-shaped shape, and is stacked in a direction perpendicular to the cross section. The imaging device according to claim 1, wherein: 3. An image pickup unit which houses at least an image pickup optical system and an image pickup element, and at least a part of an outer surface of the image pickup unit is a convex spherical surface, and an arbitrary axis passing through the center of a sphere forming the convex spherical surface. A holding member that is rotatably held around, a friction member provided on one axis passing through the center of the sphere, pressed against the convex spherical surface, and a two-dimensional piezoelectric actuator that drives the friction member, A driving mechanism for applying a turning force in two directions to the imaging unit. 4. The two-dimensional piezoelectric actuator has four arms provided approximately every 90 degrees around the friction member, and includes two non-adjacent ones of the four arms, and A cross section of the friction member, which is orthogonal to a surface that contacts the convex spherical surface of the imaging unit, has a substantially “<” shape, and is stacked in a direction orthogonal to each of the cross sections. Item 4. The imaging device according to Item 3. 5. The imaging apparatus according to claim 1, wherein the center of gravity of the imaging unit substantially coincides with the center of the sphere. 6. The imaging unit is housed in a housing, and the housing has at least a concave spherical surface facing a convex spherical surface of the imaging unit, and an opening for imaging an object by the imaging optical system. The imaging device according to any one of claims 1 to 5, further comprising: 7. The device according to claim 6, wherein a ball is provided between the convex spherical surface of the imaging unit and the concave spherical surface of the housing, and the friction member protrudes from the concave spherical surface of the housing. Imaging device. 8. The imaging device according to claim 6, wherein a seal member is provided in a gap between an opening of the housing and an outer surface of the imaging unit. 9. The imaging device according to claim 6, wherein an opening of the housing is sealed with a transparent member.