JP4417776B2 - Imaging apparatus and camera shake correction mechanism - Google Patents

Description

  The present invention relates to an image pickup apparatus that performs camera shake correction by moving an image sensor, and more particularly, to an interchangeable lens digital camera having a camera shake correction function.

  Various camera shake correction apparatuses that correct camera shake of a captured image due to camera body swing have been proposed. As one of such camera shake correction apparatuses, one that swings an image sensor so as to cancel the swing of the camera body is known. However, in a camera equipped with a camera shake correction device that swings the image sensor, it is difficult to airtightly shield the image sensor from outside air, and foreign matters such as dust adhere to the surface of the image sensor, and this appears in the captured image. As a result, there is a problem that the image quality deteriorates. In particular, in the interchangeable lens digital camera or the like, dust easily invades, which is a big problem.

In order to solve such a problem, an imaging apparatus has been proposed in which an imaging element is hermetically accommodated inside an optical filter such as a low-pass filter or an infrared cut filter, and foreign matter is prevented from adhering to the surface of the imaging element. (See Patent Document 1). Even in this imaging apparatus, foreign matter adheres to the outer surface of the filter, but by increasing the distance between the imaging element surface, which is the imaging surface, and the outer surface of the filter, it is possible to blur the image of the foreign matter and suppress degradation in image quality. is there.
JP 2003-110930 A

  However, the method of Patent Document 1 requires a sufficiently large distance between the outer surface of the filter and the surface of the image sensor, which is a design limitation and is disadvantageous in downsizing (thinning). In addition, it is difficult to maintain the image quality when the size of the foreign matter is large or when the foreign matter has accumulated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image pickup apparatus having a foreign matter removing function for removing foreign matters such as dust adhering to an image pickup element or a cover thereof with a simple configuration and low cost.

  An imaging device according to the present invention includes an imaging element, a holding member that holds the imaging element, a driving mechanism that moves the holding member in independent first and second directions in a plane parallel to the imaging surface, and a driving mechanism. And a driving mechanism that abuts the end surface of the holding member against the abutting surface of the fixing portion and moves along the abutting surface to apply an impact force to the holding member. It is characterized by giving.

  In order to prevent foreign matter from adhering directly to the image sensor, it is preferable that the image sensor is sealed in a holding member constituting a casing or the like by a transparent cover member. In such a case, foreign matters such as dust adhere to the outer surface of the cover member, but are shaken off by an impact force when the holding member is slid against the contact surface. The first and second directions are preferably orthogonal from the viewpoint of simplification of the configuration of the camera shake correction mechanism and ease of control.

  For example, the end surface of the holding member and the abutting surface of the fixing portion are formed in an uneven shape in order to give an impact force. Further, for example, by changing at least one of a pressing force for applying the end surface to the contact surface or a sliding force for movement along the contact surface, a stick slip is generated and an impact is generated. At this time, the end surface and the contact surface can be flat surfaces, for example, and the step of processing into an uneven shape can be omitted. In addition, by making at least one of the end surface or the contact surface a random friction surface, it is possible to generate stick-slip and simplify drive control.

  The drive mechanism is preferably a camera shake correction mechanism that performs camera shake correction by moving the holding member in the first and second directions, and the fixed portion is a camera shake that moves the holding member for camera shake correction. In addition to being disposed at a position beyond the correction range, the impact force on the holding member is preferably provided by engaging the holding member with the fixed portion beyond the camera shake correction range in the foreign matter removal mode.

  In addition, the camera shake correction mechanism of the digital camera of the present invention includes an image sensor and a holding member that holds the image sensor. The camera shake correction mechanism performs camera shake correction by moving the holding member in independent first and second directions in a plane parallel to the imaging surface. In addition, the camera shake correction mechanism includes a fixing unit disposed at a position beyond a camera shake correction range in which the holding member moves for camera shake correction, and an end surface of the holding member beyond the camera shake correction range. Foreign matter removing means for applying to the contact surface and moving along the contact surface to apply an impact force to the holding member is provided.

  As described above, according to the present invention, since the camera shake correction mechanism can be used together with foreign matter removal, it is possible to remove foreign matters such as dust adhering to the image sensor or its cover with a simple configuration, and the foreign matter removal function. Can be provided at low cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an electrical configuration of a digital camera 10 including a camera shake correction apparatus according to a first embodiment to which the present invention is applied. FIG. 2 is a schematic diagram showing the configuration of the digital camera 10.

  The digital camera 10 is a camera whose lens can be exchanged, for example. The subject image is formed on the imaging surface of the imaging device 13 via the imaging lens system (lens group) 11 and the transparent cover member 12 attached to the camera body. An image picked up by the image pickup device 13 is sent to the image processing circuit 14 as an image signal, and subjected to predetermined processing such as white balance processing, enhancement processing, and gamma correction processing. Thereafter, the image signal is sent to a display device 15 such as an LCD and displayed on the screen. The image sensor 13 is a CCD, for example, and is driven and controlled by a drive pulse from the driver 16.

  On the other hand, the drive of the image processing circuit 14 and the driver 16 is controlled by the control circuit 17. An actuator 18, an angular velocity sensor (gyro) 19, and a switch group 20 are further connected to the control circuit 17.

  The angular velocity sensor 19 is a sensor for detecting camera shake (vibration) of the digital camera 10, and the control circuit 17 calculates the shake amount of the camera body by monitoring the change in angular velocity, and the calculated shake amount. Based on this, the actuator 18 is driven to oscillate the image sensor 12 parallel to the imaging surface (in the plane perpendicular to the optical axis O). That is, the occurrence of camera shake is prevented by swinging the image sensor 12 in a direction that cancels camera shake caused by camera shake. In the present embodiment, as will be described later, the transparent cover member 12 is provided integrally with the imaging element 13 and constitutes the imaging unit 21. That is, in the present embodiment, the actuator 18 swings the entire imaging unit 21 in parallel to the imaging surface.

  3 is a plan view of the imaging unit 21 when viewed from the side opposite to the imaging surface of the imaging element 13, and FIG. 4 is a cross-sectional view of the imaging unit 21 taken along line IV-IV in FIG. .

  The imaging unit 21 includes, for example, a substantially rectangular parallelepiped casing (holding member) 22 that houses the cover member 12 and the imaging element 13. An opening 22a is formed on the bottom surface of the casing 22, and the opening 22a is sealed with a transparent cover member 12 made of an optical low-pass filter or an infrared cut filter. Further, in the casing 22, the opposite side of the opening 22 a is open, and the image sensor 13 attached to the substrate 23 from the open portion 22 b is accommodated in the casing 22. At this time, the peripheral edge portion of the substrate 23 is hermetically attached to the end surface of the casing 22 that defines the open portion 22b. That is, the image sensor 13 is hermetically accommodated in the casing 22 by the casing 22, the transparent cover member 12, and the substrate 23. In addition, a presser member 24 for fixing the relative positions of the image sensor 13 and the transparent cover member 12 is interposed. The light passing through the imaging lens system 11 forms an image on the imaging surface 13a of the imaging device 13 through the transparent cover member 12 provided in the opening 22a.

  The casing 22 is disposed inside the fixed frame 27 having a rectangular opening 27a formed at the center. The rectangular opening 27a is larger than the outer shape of the casing 22, and determines a range in which the casing 22 can swing. That is, the swinging of the image sensor 13 in the camera shake correction is achieved by the movement of the casing 22 in the rectangular opening 27a.

  In FIG. 3, when the horizontal axis direction of the surface parallel to the imaging surface 13 a of the image sensor 13 is the X-axis direction and the vertical axis direction is the Y-axis direction, the outside of the two opposite side walls parallel to the X axis of the casing 22. Are formed with X bearing portions 22c and 22d for inserting two rod-shaped X-axis direction guide members 25, respectively. That is, the casing 22 is slidable along the X-axis direction guide member 25. In addition, a casing abutting portion 22e that is used when removing foreign matters such as dust, which will be described later, is provided on one side surface of the casing 22 (for example, the lower side surface in FIG. 3).

  One end of each of the two X-axis direction guide members 25 is integrally connected to one rod-like Y-axis direction guide member 26 along the Y-axis that is orthogonal to the X-axis. Configure. The Y-axis direction guide member 26 is inserted into a Y bearing portion 28 provided on one side of the fixed frame body 27 (the left frame portion along the Y axis in FIG. 3), and is slidable along the Y axis direction. is there.

  The other end of the X-axis direction guide member 25 (the end opposite to the Y-axis guide member) is a pair of guide member supports provided on the right frame along the Y-axis of the fixed frame 27. 29 are inserted and supported respectively. The hole of the guide member support 29 through which the X-axis direction guide member 25 communicates has a predetermined width in the Y-axis direction, and the X-axis direction guide member 25 is slidable in the Y-axis direction along this hole. It is. That is, the U-shaped guide member can integrally move in the Y-axis direction, and the casing 22 can move in the X-axis direction along the X-axis direction guide member 25. Therefore, the casing 22 can move in the rectangular opening 27 a along the X-axis direction and the Y-axis direction orthogonal to the fixed frame body 27.

  On the other hand, the coil substrate 30 is attached to the surface of the substrate 23 opposite to the surface on which the imaging element 13 is provided. The coil substrate 30 includes an X-axis drive unit 30X and a Y-axis drive unit 30Y, and the X-axis drive unit 30X extends from the main body of the coil substrate 30 (an area attached to the substrate 23) in one of the X-axis directions (see FIG. 3 to the right). That is, the X-axis drive unit 30X extends beyond the rectangular opening 27a to a position overlapping the frame portion (right frame portion) of the fixed frame 27, and the coil 31X is provided. On the other hand, the Y-axis drive unit 30Y overlaps the frame portion (upper frame portion) of the fixed frame 27 beyond the rectangular opening 27a from one side in the Y-axis direction (upward in FIG. 3) from the main body of the coil substrate 30. The coil 31Y is provided in the same manner as the X-axis drive unit 30X.

  The X-axis drive unit 30X and the Y-axis drive unit 30Y are arranged at a predetermined distance from the fixed frame body 27, and the X-axis drive unit 30X and the Y-axis drive unit are located at positions overlapping the coils 31X and 31Y of the fixed frame body 27. U-shaped yokes 32X and 32Y surrounding 30Y are respectively provided. Further, permanent magnets 33X and 33Y fixed to the yokes 32X and 32Y are provided between the yokes 32X and 32Y and the X-axis drive unit 30X and the Y-axis drive unit 30Y, respectively. That is, the coil substrate 30 can swing in the X-axis direction and the Y-axis direction by controlling the energization of the coils 32X and 32Y. By combining these, the imaging can be performed in any direction in the XY plane. The element 13 can be swung. In FIG. 3, a part of the yokes 32X and 32Y surrounding the X-axis drive unit 30X and the Y-axis drive unit 30Y is drawn so that the X-axis drive unit 30X and the Y-axis drive unit 30Y can be seen. .

  3 is obtained by removing the coil substrate 30, the substrate 23, the yokes 31X and 31Y, and the magnets 32X and 32Y from FIG. 3, and FIG. 6 is a side elevational view from the direction of arrow A in FIG. 7 and 8 are side elevation views from the directions of arrows B and C in FIG. 5, respectively. In FIG. 7, the configuration relating to the casing 22 and the guide member support 29 is omitted, and in FIG. The configuration relating to the casing 22 and the Y bearing portion 28 is omitted.

  Next, the foreign matter removing function in the present embodiment will be described with reference to FIGS. 1, 3, and 5. The digital camera 10 includes a camera shake correction mode that uses, for example, a camera shake correction function. The actuator 18 made of 30Y or the like is driven, and the casing 22 (that is, the image sensor 13) is swung so as to cancel out camera shake. This movement is performed inside the rectangular opening 27a in a range where the casing 22 does not come into contact with the frame portion of the fixed frame body 27 (camera shake correction range).

  The digital camera 10 also has a foreign matter removal mode. For example, when the foreign matter removal mode is selected based on the operation of the switch group 20, the system control circuit 17 removes foreign matter such as dust attached to the cover member 12. Therefore, the actuator 18 is driven. In the first embodiment, the end surface 22S of the casing contact portion 22e that contacts the fixed frame body 27 is formed in, for example, a concave and convex shape having a mountain shape in a sawtooth shape, and the lower frame portion of the fixed frame body 27 that faces the end surface 22S. The inner side surface (contact surface) 27S of (in FIGS. 3 and 5) is also formed in an uneven shape. In the present embodiment, the contact surface 27S of the lower frame portion has, for example, a sawtooth shape that can be complementarily fitted with the shape of the end surface 22S. Note that the foreign matter removal mode may be automatically driven for a fixed time at a specific timing such as when the camera is activated.

  In the foreign matter removal mode, first, the Y-axis drive unit 30Y is driven, and the end surface 22S of the casing contact portion 22e is pressed against the contact surface 27S of the fixed frame 27 with a predetermined pressing force. Thereafter, the X-axis drive unit 30X is driven while maintaining the pressing force in the Y-axis direction, and the casing contact portion 22e is reciprocated in the X-axis direction (left and right). At this time, since the end surface 22S and the contact surface 27S are uneven in shape, the end surface 22S and the contact surface 27S give an impact to the casing 22 in the X-axis and Y-axis directions.

  As described above, according to the first embodiment, an impact force can be repeatedly applied to the casing by bringing the casing and the fixing portion (fixed frame portion) into contact with each other via an uneven surface and rubbing them together. . As a result, foreign matters such as dust attached to the cover member and the image sensor provided in the casing can be shaken off using this impact.

  Next, the foreign matter removing mechanism in the second embodiment will be described with reference to FIGS. 9 and 10. The configuration of the digital camera of the second embodiment is the same as that of the first embodiment except that a part of the configuration of the imaging unit 21 is different, and the same reference numerals are used for the same configuration and the description thereof is omitted.

  The end surface 22S of the casing contact portion 22e and the contact surface 27S of the fixed frame portion 27 of the first embodiment each have an uneven shape. On the other hand, the shape of the end surface 22S ′ of the casing contact portion 22e of the second embodiment and the contact surface 27S ′ of the fixed frame portion 27 that engages with the end surface 22S ′ is substantially flat, and at least one of them. Is composed of a high friction member.

  Also in the second embodiment, in the foreign substance removal mode, the Y-axis drive unit 30Y is driven, the end surface 22S ′ is pressed against the contact surface 27S ′ with a predetermined force, and the casing 22 is driven by the X-axis drive unit 30X. It is reciprocated left and right along the X axis. However, in the second embodiment, as shown in FIG. 10, the X-axis drive unit 30X is subjected to pulse driving that is repeatedly turned on and off, and the Y-axis drive unit 30Y is constant during this time. Voltage is supplied. That is, the pressing force of the end surface 22S ′ to the contact surface 27S ′ by the Y-axis drive unit 30Y is constant, but the lateral sliding force by the X-axis drive unit 30X is intermittent (periodically in this embodiment). It is.

  The end surface 22S ′ and the contact surface 27S ′ of the second embodiment are flat surfaces, but since the sliding force is intermittently turned on / off, when the X-axis drive unit 30X is in the ON state, the frictional force is increased. In contrast, when the casing 22 moves laterally and enters the OFF state, the casing 22 suddenly stops and causes a so-called stick-slip. As a result, a large acceleration is intermittently applied to the casing 22 and the foreign matter attached to the cover member 12 is shaken off.

  As described above, also in the second embodiment, substantially the same effect as in the first embodiment can be obtained. In the above description, only one of the pressing force and the sliding force is intermittently applied. However, both the pressing force and the sliding force can be an intermittent force (fluctuating force).

  FIG. 10 shows only the pulse waveform when the casing is moved in one direction of the X axis. However, when the casing is moved in the opposite direction, a pulse signal in the opposite direction is supplied. Further, even if an intermittent pulse waveform is applied to the Y-axis drive unit and a constant voltage is applied to the X-axis drive unit during this period, substantially the same effect can be obtained. That is, by controlling the strength of the frictional force while keeping the sliding force constant, the sliding between the end surface of the casing contact portion and the contact surface of the fixed frame body may be intermittent. it can.

  Next, a third embodiment of the present invention will be described with reference to FIG. Since the configuration of the third embodiment is substantially the same as that of the second embodiment, the same reference numerals are used for the configuration common to the second embodiment, and the description thereof is omitted.

  In the second embodiment, the stick-slip is realized by controlling the driving of the X-axis drive unit 30X and the Y-axis drive unit 30Y. However, in the third embodiment, the end surface of the casing contact portion 22e and the fixed frame body 27 are realized. Stick slip is realized by controlling the coefficient of friction between the contact surface and the contact surface. That is, as shown in FIG. 11, for example, the contact surface 27S ″ is a random friction surface. A sliding force is applied in the lateral direction while pressing the casing contact portion 22e against the fixed frame body 27 with a predetermined force. Then, the casing 22 repeatedly moves and stops by stick-slip, and the impact causes the foreign matter to be shaken off from the cover member etc. As described above, the third embodiment can achieve the same effect as the second embodiment. The random friction surface may be provided on the end surface of the casing contact portion 22e.

  In this embodiment, since the image sensor is hermetically accommodated in the casing, the foreign matter does not adhere to the imaging surface of the image sensor, and the foreign matter is removed from the cover member. When the surface is not airtight from the outside air, the foreign matter is removed from the imaging surface of the imaging device. In such a case, the cover member may be separated from the swinging casing (imaging device).

  In the present embodiment, the casing is moved along one side of the fixed frame body, and the casing is moved along the side. However, the one to which the casing is applied is not limited to the frame body, and may be a cover member or an image sensor. For example, a dedicated sliding member fixed to the camera body may be used. Furthermore, the first and second embodiments and the second and third embodiments can be applied in combination.

It is a block diagram which shows the structure of the digital camera of 1st Embodiment to which this invention was applied. It is a schematic diagram which shows the structure of the digital camera provided with the camera-shake correction apparatus of FIG. It is a top view when an imaging part is seen from the opposite side to the image pick-up surface of an image sensor. It is sectional drawing of the imaging part along the IV-IV line of FIG. FIG. 4 is a plan view in which a coil substrate, a substrate, a yoke, and a magnet are removed from FIG. 3. FIG. 6 is a side elevational view from the direction of arrow A in FIG. 5. FIG. 6 is a side elevational view from an arrow B in FIG. 5 in which a configuration related to a casing and a guide member support is omitted. FIG. 6 is a side elevational view from the direction of arrow C in FIG. 5 with the configuration relating to the casing and the Y bearing portion omitted. It is a top view when the imaging part of 2nd Embodiment is seen from the opposite side to the imaging surface of an image pick-up element. It is an example of the timing chart of the drive pulse applied to an X-axis drive part and a Y-axis drive part in 2nd Embodiment. It is a figure which shows typically the state of the random friction surface of the contact surface in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 13 Image pick-up element 17 Control circuit 18 Actuator 21 Imaging part 22 Casing 22e Casing contact part 22S, 22S 'End surface 27 Fixed frame body 27S, 27S', 27S "Contact surface

Claims (10)

An image sensor;
A holding member for holding the image sensor;
A drive mechanism for moving the holding member in independent first and second directions in a plane parallel to the imaging surface;
A fixed portion disposed within a movable range of the holding member by the drive mechanism,
The drive mechanism applies an end surface of the holding member having an uneven shape to the contact surface of the fixing portion having an uneven shape, and moves along the contact surface to impact the holding member. An imaging device characterized by applying force. An image sensor;
A holding member for holding the image sensor;
A drive mechanism for moving the holding member in independent first and second directions in a plane parallel to the imaging surface;
A fixed portion disposed within a movable range of the holding member by the drive mechanism,
The drive mechanism applies an end surface of the holding member to the contact surface of the fixed portion, moves along the contact surface, and a pressing force for applying the end surface to the contact surface, or An image pickup apparatus , wherein the impact is generated on the holding member by changing at least one of sliding forces for movement along the contact surface . An image sensor;
A holding member for holding the image sensor;
A drive mechanism for moving the holding member in independent first and second directions in a plane parallel to the imaging surface;
A fixed portion disposed within a movable range of the holding member by the drive mechanism,
At least one of the end surface of the holding member or the contact surface of the fixed portion is formed of a random friction surface, and the drive mechanism applies the end surface to the contact surface, along the contact surface. An image pickup apparatus that moves and applies an impact force to the holding member. Any image pickup device is sealed by a transparent cover member arranged on the optical path, the foreign matter adhering to the outer surface of the cover member, according to claim 1 to 3 characterized in that it is removed by the impact force the imaging apparatus according to an item or. The imaging apparatus according to claim 1, wherein the first and second directions are orthogonal to each other . The imaging apparatus according to claim 2 , wherein the end surface and the contact surface are flat surfaces. The drive mechanism is a camera shake correction mechanism that performs camera shake correction by moving the holding member in the first and second directions, and the holding member moves for the camera shake correction. And the impact force to the holding member is provided by engaging the holding member with the fixing portion beyond the camera shake correction range. The imaging device according to claim 1, wherein the imaging device is a feature. A camera shake correction that includes an image sensor and a holding member that holds the image sensor, and performs camera shake correction by moving the holding member in independent first and second directions in a plane parallel to the imaging surface. Mechanism,
A fixed part that is disposed at a position beyond a camera shake correction range in which the holding member moves for the camera shake correction;
Together abutted to the abutting surface being an end surface which is uneven shape of the holding member and the front Symbol fixing portion of the uneven shape, the foreign matter impacting force to the holding member to move along said contact surface And a camera shake correction mechanism for the digital camera. A camera shake correction that includes an image sensor and a holding member that holds the image sensor, and performs camera shake correction by moving the holding member in independent first and second directions in a plane parallel to the imaging surface. Mechanism,
A fixed part that is disposed at a position beyond a camera shake correction range in which the holding member moves for the camera shake correction;
While applying the end surface of the holding member to the contact surface of the fixed portion and moving along the contact surface, the pressing force for applying the end surface to the contact surface, or the contact surface Foreign matter removing means for generating the impact on the holding member by varying at least one of the sliding forces for movement along
A camera shake correction mechanism for a digital camera, comprising: A camera shake correction that includes an image sensor and a holding member that holds the image sensor, and performs camera shake correction by moving the holding member in independent first and second directions in a plane parallel to the imaging surface. Mechanism,
A fixed part that is disposed at a position beyond a camera shake correction range in which the holding member moves for the camera shake correction;
At least one of the end surface of the holding member or the contact surface of the fixed portion is formed of a random friction surface, and the drive mechanism applies the end surface to the contact surface, along the contact surface. Foreign matter removing means for moving and applying an impact force to the holding member;
A camera shake correction mechanism for a digital camera, comprising:

Images