JP2008236371A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact imaging apparatus. <P>SOLUTION: The imaging apparatus for correcting camera-shake by moving an imaging optical system 2 to an imaging element 14 is constituted so that a gyro sensor 50 is attached to the same face side of a wiring board 60, to which the imaging element 14 is attached. A total thickness of the imaging element 14 and the gyro sensor 50 is thinner than when the gyro sensor 50 is attached to a rear face side of the imaging element 14, thereby reducing the apparatus in size. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus used for photographing and the like.

2. Description of the Related Art Conventionally, as an imaging apparatus such as a camera, a video camera, or a camera mounted on a mobile phone, an apparatus that performs camera shake correction by relatively moving an imaging element and an imaging optical system is known (for example, Patent Document 1). In such an imaging apparatus, a gyro sensor is used to detect the amount of camera shake. At that time, in order to detect the amount of camera shake based on the image sensor, a gyro sensor is generally disposed on the back side of the image sensor.
JP 2004-194157 A

  However, in such an imaging apparatus, the combined thickness of the imaging element and the gyro sensor is increased, and it is difficult to reduce the imaging apparatus in the optical axis direction. When the imaging device is a camera built in a mobile phone, it is required to reduce the size of the imaging device, and in particular, to reduce the thickness in the optical axis direction and to reduce the thickness.

  Accordingly, the present invention has been made to solve such a technical problem, and an object of the present invention is to provide an imaging apparatus capable of downsizing the apparatus.

  That is, the imaging apparatus according to the present invention is an imaging apparatus that performs camera shake correction by moving an imaging optical system with respect to an imaging element. The imaging element forms a wiring terminal at an outer edge portion, and at least the wiring terminal at an outer edge portion. Is a surface-mount type element having a region where no image is formed, and is mounted on the same surface side of the wiring board to which the image pickup device is attached, and is arranged on the side where the wiring terminal of the image pickup device is not formed, and detects the amount of camera shake A gyro sensor is provided.

  According to the present invention, by attaching the gyro sensor to the same surface side of the wiring board to which the image sensor is attached, the combined thickness of the image sensor and the gyro sensor is smaller than when the gyro sensor is attached to the back surface side of the image sensor. This can reduce the size of the apparatus. At that time, the gyro sensor can be arranged in the vicinity of the image sensor by arranging the gyro sensor on the side without the wiring terminal of the image sensor. For this reason, camera shake detection based on the image sensor can be accurately performed.

  The image pickup apparatus according to the present invention is an image pickup apparatus that performs image stabilization by moving the image pickup optical system with respect to the image pickup optical system and the image pickup element, and is on the same surface side of the wiring board to which the image pickup element is attached. And a piezoelectric actuator that is disposed on the side where the wiring terminal is not formed and moves the image pickup optical system and the image pickup device relatively.

  According to the present invention, by arranging the piezoelectric actuator on the same surface side of the wiring board to which the image pickup device is attached and without the wiring terminal of the image pickup device, the size of the combined image pickup device and the piezoelectric actuator can be reduced. And the size of the apparatus can be reduced.

  According to the present invention, the device can be reduced in size and thickness.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is an exploded perspective view of an imaging unit and a camera shake correction mechanism in an imaging apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an arrangement of the imaging element, the gyro sensor, and the piezoelectric element in the imaging apparatus according to the present embodiment.

  The imaging apparatus according to the present embodiment is an apparatus that performs camera shake correction by moving the imaging optical system 2 with respect to the imaging element 14, and is mounted on a camera that captures still images, a video camera that captures moving images, and a mobile phone. This is applied to an image pickup apparatus.

  First, the configuration of the imaging apparatus according to the present embodiment will be described. As illustrated in FIG. 1, the imaging apparatus according to the present embodiment includes an imaging optical system 2 and an imaging element 14 for acquiring an image of a subject. The imaging optical system 2 is an optical system that focuses light on the imaging device 14 and includes a photographic lens. The imaging optical system 2 is configured by accommodating a lens (not shown) in a holder 2a, for example. The imaging optical system 2 may be composed of a single lens or a lens group composed of a plurality of lenses.

  The imaging optical system 2 is attached to the second moving member 5 and is provided so as to be relatively movable with respect to the imaging element 14 in a direction orthogonal to the direction of the optical axis O (optical axis direction). The second moving member 5 is housed in the image sensor holder 13 that fixes the image sensor 14 and is supported by the sphere 4 so that the second moving member 5 moves relative to the image sensor holder 13 and the image sensor 14 in a direction perpendicular to the optical axis direction. It is possible. For this reason, the imaging optical system 2 moves relative to the imaging element 14 in a direction orthogonal to the optical axis direction when the imaging optical system 2 moves together with the second moving member 5.

  At this time, it is preferable that the imaging optical system 2 is attached to the second moving member 5 so as to be movable in the optical axis direction. For example, the support shaft 3 facing the optical axis direction is attached to the second moving member 5, and the imaging optical system 2 is attached so as to be movable along the support shaft 3. As the actuator 10 that moves the imaging optical system 2 in the optical axis direction, an actuator that includes a drive shaft 10b that reciprocates by expansion and contraction of the piezoelectric element 10a is used. The actuator 10 functions as a third actuator that moves the imaging optical system 2 in the optical axis direction. The piezoelectric element 10 a is attached to the second moving member 5, and the drive shaft 10 b is frictionally engaged with the imaging optical system 2 by the friction engagement portion 22. One end of the drive shaft 10b is in contact with the piezoelectric element 10a and is bonded using, for example, an adhesive. The drive shaft 10b is a long member, for example, a cylindrical member.

  As the friction engagement structure, for example, a structure in which the drive shaft 10b is pressed against the holder 2a of the imaging optical system 2 with a constant pressing force by a plate spring, and a constant friction force is generated when the drive shaft 10b moves. And By moving the drive shaft 10b so as to exceed this frictional force, the position of the imaging optical system 2 is maintained by inertia. On the other hand, when the drive shaft 10b moves in the reverse direction so as not to exceed the frictional force, the imaging optical system 2 also moves in the reverse direction. By repeating such reciprocating movement of the drive shaft 10b, the imaging optical system 2 can be moved relative to the second moving member 5. An electric signal for making the extension speed and the contraction speed different from each other is input to the piezoelectric element 10a from a control unit (not shown). Thereby, the drive shaft 10b reciprocates at different speeds, and the movement control of the imaging optical system 2 can be performed.

  In this manner, by attaching the imaging optical system 2 to the second moving member 5 so as to be movable in the optical axis direction, focusing is performed by moving only the imaging optical system 2 in the optical axis direction with respect to the second moving member 5. be able to. For this reason, it is not necessary to perform focusing by moving the entire camera shake correction mechanism. Accordingly, since the parts that move due to focusing become smaller, the camera shake correction mechanism can be made smaller.

  The imaging element 14 is an imaging unit that converts an image formed by the imaging optical system 2 into an electrical signal, and is installed on the wiring board 60. The wiring board 60 is fixedly attached to the image sensor holder 13. For example, a CCD sensor is used as the image sensor 14.

  The image sensor 14 is of a surface mount type and is connected to the wiring board 60 by wire bonding. A plurality of bonding pads 14 a are formed on the image sensor 14. The bonding pads 14 a are wiring terminals for connecting the wires 61 and are formed along the outer edge portion of the image sensor 14. In the outer edge portion of the image sensor 14, at least a region where the bonding pad 14 a is not formed is provided. For example, when the image sensor 14 is rectangular, at least one of the four sides has a structure in which the bonding pad 14a is not formed.

  A gyro sensor 50 is installed on the wiring board 60. The gyro sensor 50 functions as a camera shake detection unit that detects the camera shake amount of the imaging apparatus, and a sensor that can detect camera shake amounts in two directions of the X direction and the Y direction orthogonal to the optical axis direction is used. For example, it is preferable to use a package in which two sensor units for detecting camera shake amounts in the X direction and the Y direction are accommodated in one package.

  The gyro sensor 50 is attached to the same surface side of the wiring board 60 to which the image sensor 14 is attached, and is arranged on the side where the bonding pad 14a of the image sensor 14 is not formed.

  By attaching the gyro sensor 50 to the same surface side of the wiring substrate 60 to which the image sensor 14 is attached, the combined thickness of the image sensor 14 and the gyro sensor 50 is compared with the case where the gyro sensor 50 is attached to the back surface side of the image sensor 14. The imaging device can be made smaller and thinner.

  Further, by arranging the gyro sensor 50 on the side where the bonding pad 14 a of the image sensor 14 is not formed, the gyro sensor 50 can be arranged in the vicinity of the image sensor 14. For this reason, it is possible to accurately detect a camera shake state based on the image sensor 14.

  The actuator 10 is preferably arranged on the same surface side of the wiring substrate 60 to which the imaging device 14 is attached and on the side where the bonding pad 14a of the imaging device 14 is not formed. In this case, the combined size of the image sensor 14 and the actuator 10 can be reduced, and the image pickup apparatus can be downsized.

  The imaging apparatus according to the present embodiment includes a first actuator 8, a second actuator 6, and a first moving member 11. The first actuator 8 is an actuator that relatively moves the imaging optical system 2 and the imaging element 14 in a first direction (pitch direction) X orthogonal to the optical axis direction. As the first actuator 8, for example, an actuator having a drive shaft 8b that reciprocates by expansion and contraction of the piezoelectric element 8a is used. The drive shaft 8b is disposed toward the first direction X. The piezoelectric element 8a is attached to the image sensor holder 13 to which the image sensor 14 is fixed. The drive shaft 8 b is frictionally engaged with the first moving member 11 by the friction engagement portion 21. One end of the drive shaft 8b is in contact with the piezoelectric element 8a and is bonded using, for example, an adhesive. The drive shaft 8b is a long member, for example, a cylindrical member.

  As the friction engagement structure, for example, the drive shaft 8b is pressed against the first moving member 11 with a constant pressing force by a plate spring, and a constant friction force is generated when the drive shaft 8b moves. To do. When the drive shaft 8b moves so as to exceed this frictional force, the position of the first moving member 11 is maintained by inertia. On the other hand, when the drive shaft 8b moves in the opposite direction so as not to exceed the frictional force, the first moving member 11 also moves in the opposite direction. By repeating such reciprocating movement of the drive shaft 8b, the first moving member 11 can be moved along the first direction X with respect to the image pickup device 14, and the image pickup optical system 2 can be moved relative to the image pickup device 14. Can be moved in the first direction X. An electric signal for making the extension speed and the contraction speed different from each other is input to the piezoelectric element 8a from the first control unit 30 (see FIG. 3). Thereby, the drive shaft 8b can reciprocate at different speeds, and the movement control of the imaging optical system 2 can be performed.

  The first actuator 8 may be configured by attaching the piezoelectric element 8 a to the first moving member 11 side and frictionally engaging the drive shaft 8 b with the imaging element holder 13.

  The second actuator 6 is an actuator that relatively moves the imaging optical system 2 and the imaging element 14 in a second direction (yaw direction) Y orthogonal to the optical axis direction. The second actuator 6 and the first actuator 8 function as driving means for moving the imaging optical system 2 and the imaging element 14 relative to each other.

  The second direction Y is a direction orthogonal to the optical axis direction and intersecting the first direction X. For example, the second direction Y is set to a direction orthogonal to the first direction X. As this second actuator 6, for example, an actuator provided with a drive shaft 6b that reciprocates by expansion and contraction of the piezoelectric element 6a is used. The drive shaft 6b is disposed toward the second direction Y. The piezoelectric element 6 a is attached to the second moving member 5. The drive shaft 6 b is frictionally engaged with the first moving member 11 by the friction engagement portion 20. One end of the drive shaft 6b is in contact with the piezoelectric element 6a and is bonded using, for example, an adhesive. The drive shaft 6b is a long member, and for example, a cylindrical member is used.

  As the friction engagement structure, for example, the drive shaft 6b is pressed against the first moving member 11 with a constant pressing force by a plate spring, and a constant friction force is generated when the drive shaft 6b moves. To do. When the drive shaft 6b moves in one direction so as to exceed this frictional force, the position of the second moving member 5 is maintained by inertia. On the other hand, if the drive shaft 6b tries to move in the opposite direction so as not to exceed the frictional force, the second moving member 5 moves in one direction while the drive shaft 6b remains stationary by the frictional force. By repeating such reciprocating movement of the drive shaft 6b, the second moving member 5 can be moved along the second direction Y with respect to the image pickup device 14, and the image pickup optical system 2 can be relatively moved with respect to the image pickup device 14. Can be moved in the second direction Y. An electric signal for making the extension speed and the contraction speed different from each other is input to the piezoelectric element 6a from the first control unit 30 (see FIG. 3). Thereby, the drive shaft 6b reciprocates at different speeds, and the movement control of the imaging optical system 2 can be performed.

  The second actuator 6 is attached to the first moving member 11 by the friction engagement described above. For this reason, when the first moving member 11 moves in the first direction X by the operation of the first actuator 8, the second actuator 6 also moves in the first direction X.

  The second actuator 6 may be configured by attaching the piezoelectric element 6 a to the first moving member 11 side and frictionally engaging the drive shaft 6 b with the second moving member 5.

  The imaging device is provided with a position detection magnet 9 and a Hall element 15. The position detection magnet 9 is a magnet attached to the second moving member 5, and may be any one that generates a magnetic field that can be detected by the Hall element 15. The Hall element 15 is a magnetic sensor that detects the relative position of the imaging element 14 and the imaging optical system 2 with respect to the direction orthogonal to the optical axis direction based on the state of the magnetic field generated from the position detection magnet 9. Attached to. The board | substrate 17 is a wiring board attached to the image pick-up element holder 13, and is bent and used for L shape, for example. The lead wires of the piezoelectric elements 6a, 8a and 10a are attached to the substrate 17 respectively.

  A photo interrupter 16 is provided in the imaging apparatus. The photo interrupter 16 is a position detection sensor that detects the position of the imaging optical system 2. The photo interrupter 16 is attached to the substrate 17 and is disposed in the vicinity of the imaging optical system 2. The photo interrupter 16 includes a light emitting unit and a light receiving unit, and detects the position of the imaging optical system 2 in the optical axis direction through position detection of the moving piece 2b passing between the light emitting unit and the light receiving unit. The moving piece 2 b is a member that is formed in the holder 2 a of the imaging optical system 2 and moves together with the imaging optical system 2.

  The imaging apparatus includes an upper cover 1. The upper cover 1 is a cover that covers the opening of the image sensor holder 13 that houses the image pickup unit and the camera shake correction mechanism, and forms an opening 1a for entering a subject image.

  The first moving member 11 is supported by the first support shaft 12 so as to be movable along the first direction X. The first support shaft 12 is a shaft member disposed in the first direction X, and is attached to the image sensor holder 13. The first support shaft 12 is provided through the bearing portion 11 a of the first moving member 11. Accordingly, the first moving member 11 is supported by the first support shaft 12 so as to move only in the first direction X with respect to the imaging element 14.

  The first support shaft 12 is disposed on the first actuator 8 side with respect to the imaging optical system 2. That is, the first support shaft 12 is not disposed on the opposite side of the first actuator 8 with the imaging optical system 2 interposed therebetween, but is disposed on the first actuator 8 side. For this reason, the movement mechanism by the first actuator 8 and the support mechanism by the first support shaft 12 can be integrated into a compact configuration.

  The second moving member 5 is supported by the second support shaft 7 so as to be movable along the second direction Y. The second support shaft 7 is a shaft member arranged in the second direction Y, and is attached to the second moving member 5. The second support shaft 7 is provided through the bearing portion 11 b of the first moving member 11. Thus, the second moving member 5 is supported by the second support shaft 7 so as to move only in the second direction Y with respect to the first moving member 11.

  The second support shaft 7 is disposed on the second actuator 6 side with respect to the imaging optical system 2. That is, the second support shaft 7 is not disposed on the opposite side of the second actuator 6 across the imaging optical system 2 but is disposed on the second actuator 6 side. For this reason, the movement mechanism by the 2nd actuator 6 and the support mechanism by the 2nd support shaft 7 can be put together, and can be comprised compactly.

  FIG. 3 is a block diagram illustrating an electrical configuration of the imaging apparatus according to the present embodiment. FIG. 4 is a schematic diagram of a camera shake correction circuit in the imaging apparatus according to the present embodiment.

  As shown in FIG. 3, the imaging apparatus according to the present embodiment includes a first control unit 30, a gyro sensor 50, and a second control unit 40. The first control unit 30 functions as a control unit that controls the relative movement of the image pickup optical system 2 and the image pickup element 14 in the direction orthogonal to the optical axis direction to perform camera shake correction. The first control unit 30 is configured by, for example, an LSI (Large Scale Integration) incorporating a CPU and a driver chip. The gyro sensor 50 functions as a camera shake detection sensor that detects the amount of camera shake.

  The first control unit 30 inputs the detection signal S1x of the gyro sensor 50 and the detection signal S2x of the hall element 15, and outputs a drive control signal Sx to the first actuator 8. The detection signal S1x of the gyro sensor 50 is a detection signal related to the amount of camera shake in the X direction (first direction X). The detection signal S2x of the hall element 15 is a detection signal related to the relative position of the imaging element 14 and the imaging optical system 2 in the X direction.

  Further, the first control unit 30 inputs the detection signal S1y of the gyro sensor 50 and the detection signal S2y of the hall element 15, and outputs a drive control signal Sy to the second actuator 6. The detection signal S1y of the gyro sensor 50 is a detection signal related to the amount of camera shake in the Y direction. The detection signal S2y of the hall element 15 is a detection signal related to the relative position of the imaging element 14 and the imaging optical system 2 in the Y direction (second direction Y).

  For example, as shown in FIG. 4, a camera shake correction circuit using a differential amplifier 31 is provided in the first control unit 30. This camera shake correction circuit is provided with two types, one that performs camera shake correction in the X direction and one that performs camera shake correction in the Y direction. The camera shake correction circuit in the X direction outputs a drive control signal Sx to the first actuator 8 according to the difference between the detection signal S1x of the gyro sensor 50 and the detection signal S2x of the hall element 15. The camera shake correction circuit in the Y direction outputs a drive control signal Sy to the second actuator 6 according to the difference between the detection signal S1y of the gyro sensor 50 and the detection signal S2y of the hall element 15. As a result, the camera shake correction is performed by reducing the difference between the camera shake amount and the relative movement amount of the imaging optical system 2 and the image sensor 14.

  The detection signals S1x and S1y of the gyro sensor 50 are preferably integrated by the integration circuit 32 and input to the differential amplifier 31. The detection signals S2x and S2y of the Hall element 15 are preferably input to the differential amplifier 31 after being amplified by the amplifier circuit 33.

  In FIG. 3, the second control unit 40 functions as a control unit that controls movement of the imaging optical system 2 in the optical axis direction. The second control unit 40 is configured by, for example, an autofocus IC or a microcomputer. The second control unit 40 acquires distance information to the subject using a distance measuring device (not shown), and outputs a drive control signal to the actuator 10 based on the distance information and a detection signal of the photo interrupter 16, Move control.

  Next, an operation at the time of camera shake correction of the imaging apparatus according to the present embodiment will be described.

  In FIG. 3, when camera shake occurs when shooting using the imaging device, the gyro sensor 50 detects the camera shake amount, and outputs camera shake detection signals S 1 x and S 1 y to the first control unit 30. The first control unit 30 includes the first actuator 8 and the second actuator so that the image picked up by the image pickup device 14 is not blurred based on the detection signals S1x and S1y of the gyro sensor 50 and the detection signals S2x and S2y of the hall element 15. 6 outputs a drive control signal.

  Then, in the first actuator 8 and the second actuator 6, the piezoelectric elements 8a and 6a are operated so that the extension speed and the contraction speed thereof are different, and the drive shafts 8b and 6b repeatedly move back and forth. The first moving member 11 moves in the first direction X with respect to the imaging element 14 by driving the first actuator 8, and the imaging optical system together with the second moving member 5 with respect to the first moving member 11 by driving the second actuator 6. 2 moves in the second direction Y, and the image sensor 14 and the imaging optical system 2 move relatively. Thereby, even if camera shake occurs in the imaging apparatus, the imaging device 14 and the imaging optical system 2 are relatively moved and controlled, and the camera shake of the captured image of the imaging device 14 is suppressed.

  As described above, according to the imaging apparatus according to the present embodiment, the gyro sensor 50 is attached to the back surface side of the imaging element 14 by attaching the gyro sensor 50 to the same side of the wiring board 60 to which the imaging element 14 is attached. Compared to the case, the combined thickness of the imaging element 14 and the gyro sensor 50 can be reduced, and the imaging apparatus can be downsized. At that time, the gyro sensor 50 can be disposed in the vicinity of the image sensor 14 by disposing the gyro sensor 50 on the side without the wiring terminal of the image sensor 14. For this reason, camera shake detection based on the imaging element 14 can be performed with high accuracy.

  In addition, by arranging the piezoelectric actuator on the same surface side of the wiring board 60 to which the imaging element 14 is attached and on the side without the wiring terminal of the imaging element 14, the combined dimension of the imaging element 14 and the piezoelectric actuator is reduced. Thus, the imaging apparatus can be reduced in size.

  In addition, the image pickup apparatus according to the present embodiment is optimal as an image pickup apparatus for a mobile phone because the size in the optical axis direction can be reduced and the thickness can be reduced.

  The embodiment described above shows an example of an imaging apparatus according to the present invention. The imaging device according to the present invention is not limited to the imaging device according to these embodiments, and the imaging device according to the embodiment may be modified or otherwise changed without changing the gist described in each claim. It may be applied to. For example, in the present embodiment, the case where the gyro sensor 50 and the actuator 10 are arranged on the side of the image sensor 14 on the side where the bonding pad 14a is not formed has been described. However, as shown in FIG. 10 may be arranged on the side of the region where the bonding pad 14a of the image sensor 14 is not formed. For example, the gyro sensor 50 and the actuator 10 are located in the vicinity of the image sensor 14 as long as they are on the side where the bonding pad 14a of the image sensor 14 is formed but on the side where the bonding pad 14a is not formed. Therefore, the combined dimensions of the image sensor 14, the gyro sensor 50, and the actuator 10 can be reduced.

  For example, in the present embodiment, an actuator using a piezoelectric element is used as the actuator of the imaging apparatus, but an actuator using another driving component such as a motor may be used.

1 is an exploded perspective view of an imaging apparatus according to an embodiment of the present invention. It is a figure which shows arrangement | positioning of the image pick-up element of the imaging device of FIG. 1, and a gyro sensor. FIG. 2 is a block diagram illustrating an electrical configuration in the imaging apparatus of FIG. 1. FIG. 2 is a schematic diagram of a camera shake correction circuit in the imaging apparatus of FIG. 1. It is explanatory drawing of the modification in the imaging device of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Upper cover, 2 ... Imaging optical system, 3 ... Support shaft, 4 ... Ball, 5 ... Second moving member, 6 ... Second actuator, 7 ... Second support shaft, 8 ... First actuator, 9 ... Position detection Magnets, 10 ... Actuator, 11 ... First moving member, 12 ... First support shaft, 13 ... Image sensor holder, 14 ... Image sensor, 14a ... Bonding pad, 15 ... Hall element, 16 ... Photo interrupter, 17 ... Substrate , 20, 21, 22 ... friction engagement part, 30 ... first control part, 40 ... second control part, 50 ... gyro sensor, 60 ... wiring board.

Claims (2)

In an imaging apparatus that performs image stabilization by moving an imaging optical system with respect to an imaging element,
The imaging element is a surface-mount type element having a region where the wiring terminal is not formed at least on the outer edge while forming the wiring terminal on the outer edge,
A gyro sensor that is attached to the same surface side of the wiring board to which the imaging element is attached and is arranged on the side where the wiring terminal of the imaging element is not formed, and that detects a shake amount;
An imaging apparatus characterized by the above. In an imaging apparatus that performs image stabilization by moving the imaging optical system with respect to the imaging optical system and the imaging element,
A piezoelectric actuator disposed on the same surface side of the wiring board to which the image pickup device is attached and on which the wiring terminal of the image pickup device is not formed, and relatively moving the image pickup optical system and the image pickup device; ,
An imaging apparatus characterized by the above.

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