JP4417775B2 - 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 fixing portion disposed within the movable range of the holding member, and the drive mechanism applies an impact force to the holding member by engaging the holding member with the fixing portion.

  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 hit against the fixed portion. 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, in the simple control in the foreign substance removal mode, the holding member is moved in the first direction and collided with the fixed portion. In order to more effectively shake off the foreign matter, it is preferable to repeatedly perform the collision with the fixed portion by high-frequency pulse driving. Other foreign matter removing operations include a method of alternately causing the holding members to collide with a pair of fixing portions provided in the front-rear direction in the first direction, or moving the holding members further in the second direction to fix the holding portions. There is a way to make it collide. In the latter case, the holding member collides with, for example, any or all of the fixed portions provided in four directions surrounding the holding member, and can apply impact force in various directions to the foreign matter, thereby removing the foreign matter more reliably. Can be done. Note that the fixed portion is made of a frame surrounding the holding member, for example.

  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 for a digital camera according to the present invention includes an imaging element and a holding member that holds the imaging element. The camera shake correction mechanism corrects camera shake 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 engages the holding member with the fixed part that is located beyond the camera shake correction range where the holding member moves for camera shake correction. And foreign matter removing means for applying an impact force to the holding member.

  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 device according to an 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 swing the image sensor 13 parallel to the imaging surface (within the vertical plane of the optical axis O). That is, the occurrence of camera shake is prevented by swinging the image sensor 13 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 hitting portion 22e used for 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, 4, and 9. The digital camera 10 includes, for example, a camera shake correction mode that uses a camera shake correction function. When the camera shake correction mode is set, the digital camera 10 is based on the signals from the angular velocity sensor 19 and the X-axis drive unit 30X and the Y-axis drive unit. 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 substance removal mode. For example, when the foreign substance removal mode is selected based on the operation of the switch group 20, the control circuit 17 removes foreign substances such as dust attached to the cover member 12. The actuator 18 is driven. For example, in the present embodiment, only the Y-axis drive unit 30Y is driven, and the casing hitting part 22e is repeatedly hit against one side of the fixed frame 27, in this embodiment, the edge of the lower frame part. At this time, the actuator 18 (Y-axis drive part 30Y) is driven by a high frequency pulse, and the casing hitting part 22e is hit against the frame part at a high frequency. 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.

  3, 4, etc., the casing 22 is struck by the lower frame part, but may be repeatedly struck by high-frequency vibration on the upper frame part or any of the left and right frame parts as shown in FIG. 9. .

  As described above, according to this embodiment, since the impact force can be repeatedly applied to the casing by repeatedly hitting the casing against one side of the fixed frame body, the dust adhered to the cover member provided on the casing. Such foreign matter can be shaken off using this impact.

  Next, a modified example of the foreign substance removal operation in the foreign substance removal mode will be described with reference to FIGS.

  In the above embodiment, the casing 22 is hit against one frame of the fixed frame 27. However, in the modified example of FIG. 10, the casing 22 is repeatedly hit against the left and right sides or the upper and lower sides of the frame alternately. Thereby, the direction of the impact applied to the foreign material can be two directions opposite to each other, and the foreign material can be more reliably shaken off. In this modified example, the foreign matter removing operation is executed using only one of the X-axis drive unit 30X and the Y-axis drive unit 30Y of the actuator 18, for example.

  In the modification shown in FIG. 11, both the X-axis drive unit 30X and the Y-axis drive unit 30Y are driven, and one corner of the casing 22 is repeatedly hit against one corner of the rectangular opening 27a. In the modification of FIG. 12, the casing 22 is moved in an oblique direction (for example, an oblique 45 ° direction) to strike one frame portion of the rectangular opening 27 a from the oblique direction, and then the moving direction is changed by, for example, 90 °, Casing 22 is hit against the adjacent frame. This is repeated sequentially and the casing 22 is hit | damaged sequentially to the four frame parts of the rectangular opening part 27a. According to the modification of FIG. 11 and FIG. 12, since an impact can be applied in an oblique direction, foreign substances that easily fall off in the oblique direction can be effectively removed.

  Note that the foreign matter removal operation described in the present embodiment and the foreign matter removal operation in the modification can be used in combination. Moreover, the angle of the moving direction of a casing can be taken in various directions. In addition, in description of the modification, although the description regarding a casing hitting part was abbreviate | omitted, a casing hitting part is each provided in the side surface of the direction where a casing is hit | damaged as needed.

  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 struck to the fixed frame. However, the target to which the casing is struck is not limited to the frame, and may be any device that can apply an impact force to the cover member and the image sensor. It may be a member dedicated to driving.

It is a block diagram which shows the structure of the digital camera which is one 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. 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 schematic diagram of the foreign material removal operation in the present embodiment. It is a schematic diagram of the modification of a foreign material removal operation | movement. It is a schematic diagram of the modification of a foreign material removal operation | movement. It is a schematic diagram of the modification of a foreign material removal operation | movement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 13 Image pick-up element 17 Control circuit 18 Actuator 21 Image pick-up part 22 Casing 22e Casing hitting part 27 Fixed frame

Claims (11)

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 image pickup apparatus, wherein the driving mechanism applies an impact force to the holding member by causing the holding member to collide with the fixed portion.   The imaging according to claim 1, wherein the imaging element is sealed by a transparent cover member disposed on an optical path, and foreign matter attached to an outer surface of the cover member is removed by the impact force. apparatus.   The imaging apparatus according to claim 1, wherein the first and second directions are orthogonal to each other.   The imaging apparatus according to claim 3, wherein the impact force is applied when the holding member is moved in the first direction and is caused to collide with the fixed portion in the foreign substance removal mode. The imaging apparatus according to claim 4, wherein the holding member collides with the fixed portion repeatedly by high-frequency pulse driving of an actuator of the driving mechanism .   5. The imaging apparatus according to claim 4, wherein in the foreign matter removal mode, the holding member is caused to collide alternately with the fixed portions provided in a pair in the front-rear direction in the first direction.   The imaging apparatus according to claim 4, wherein in the foreign matter removal mode, the holding member is further moved in the second direction and is caused to collide with the fixed portion.   The imaging apparatus according to claim 7, wherein the holding member is caused to collide with the fixing portion provided in four directions surrounding the holding member in the foreign substance removal mode.   The imaging apparatus according to claim 1, wherein the fixing unit is a frame that surrounds the holding member. 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 given by the holding member colliding with the fixed part beyond the camera shake correction range. The imaging apparatus according to claim 1. 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;
A camera shake correction mechanism for a digital camera, comprising: foreign matter removing means for applying an impact force to the holding member by causing the holding member to collide with the fixed portion beyond the camera shake correction range.

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