JP2015011165A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device suitable for suppressing image blurring due to rotation with an axis orthogonal to an imaging surface as a center without increasing the size of the device.SOLUTION: An imaging device suitable for image blurring correction for reducing the image blurring of a pickup image due to blurring includes: a base member 5; a rotary member 3 for holding a member holding an imaging element 1; a plurality of support members 7 arranged between the rotary member 3 and the base member 5 for rotatably supporting the rotary member 3 with an axis orthogonal to the imaging surface of the imaging element 1 as a center with respect to the base member 5; a plate spring 8 for energizing the support member 7 with respect to the rotary member 3 and the base member 5; and regulation means (3h, 5h) for regulating the movement of a ball 7 in an axial direction orthogonal to the imaging surface and the movement of the ball 7 in the imaging surface direction.

Description

  The present invention relates to an imaging apparatus suitable for optically correcting image blur due to camera shake or the like.

  2. Description of the Related Art Conventionally, when a photographer uses a camera or a camcorder to perform hand-held shooting, image shake may occur in a captured image due to camera shake of the photographer. Image shake due to shake in the direction in which the optical axis of the camera or camcorder is tilted (pitch direction and yaw direction) is a direction perpendicular to the optical axis of the imaging optical system for some lenses or imaging elements included in the imaging optical system. It can be corrected by an image blur correction device having a mechanism for moving the image to the right.

  On the other hand, shake around the optical axis (roll direction) of the camera or camcorder also affects image shake. Patent Document 1 discloses an imaging apparatus including a rotation mechanism that detects an inclination in a roll direction of a camera with an inclination sensor and rotates an imaging element. Patent Document 2 discloses an imaging apparatus that includes a rotary frame unit that holds an imaging device supported by a rotation center axis and includes two rotation driving units. Then, the two rotational driving units are controlled so that the directions of the rotational forces of these two rotational driving units are different from each other, and the gap between the rotation center axis and the rotating frame unit is eliminated by the resultant force of the rotational force in each direction.

Japanese Patent Laid-Open No. 06-030327 JP 2010-128386 A

  However, in the configuration of the rotation shaft as shown in Patent Document 2, the unit becomes thicker in the optical axis direction by the amount corresponding to the rotation center axis. In addition, there is a possibility that image blur occurs due to the looseness of the rotation shaft.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image pickup apparatus suitable for image blur correction that does not increase the thickness in the optical axis direction and minimizes image blur due to rattling of the rotation axis.

  In order to achieve the above object, an imaging apparatus of the present invention is disposed between a base member, a rotating member that holds a member that holds an imaging element, the rotating member, and the base member, and A plurality of support members for supporting the moving member with respect to the base member so as to be rotatable about an axis orthogonal to the imaging surface of the imaging element, and attaching the support member to the rotating member and the base member. It is characterized by comprising biasing means for biasing, and restricting means for restricting movement of the support member in the axial direction perpendicular to the imaging surface and movement in the imaging surface direction.

  According to the present invention, it is possible to provide an imaging apparatus capable of performing image blur correction without increasing the thickness in the optical axis direction and minimizing the image blur due to the wobbling of the rotation axis.

It is a figure which shows typically embodiment of the camera provided with the image blurring correction mechanism using this invention. 3 is an exploded perspective view of a second correction unit 21. FIG. It is the figure which looked at the 2nd correction unit 21 from the optical axis direction image sensor side. 3 is a perspective view of a rotating member 3. FIG. It is a perspective view of the rotation member 3 seen from the direction different from FIG. It is AA sectional drawing of the 2nd correction | amendment unit 21 shown by FIG. FIG. 4 is a cross-sectional view of the second correction unit 21 shown in FIG. 3 taken along the line BB. It is CC sectional drawing of the 2nd correction | amendment unit 21 shown by FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a schematic diagram of a digital camera as an imaging apparatus having a lens barrel 10 and a camera body 20 equipped with an image blur correction mechanism according to an embodiment of the present invention. The present invention is not limited to this embodiment, and a digital single-lens reflex camera in which the lens barrel 10 can be attached to and detached from the camera body 20 may be used. In this case, the image blur correction mechanism is disposed on the unit (camera body 20) side having the image sensor.

  The second correction unit 21 as an image shake correction mechanism according to the present invention is an image in the direction (roll direction) around the optical axis O of the lens barrel 10 among the shakes of the image on the imaging surface caused by shake applied to the apparatus. Reduce shake. In the embodiment of the present invention, in addition to the second correction unit 21, the lens barrel 10 includes a first correction unit 11 for correcting image shake due to shake in the pitch direction and yaw direction.

  The lens barrel 10 includes a lens group that forms an imaging optical system in addition to the correction lens L1 and the fixed lens L2. The first correction unit 11 includes an image shake correction base member 12 and a holding frame 13. The image blur correcting base member 12 is fixed to the lens barrel 10. The image blur correction base member 12 holds the fixed lens L2.

  The holding frame 13 holds the correction lens L1. The image blur correction base member 12 and the holding frame 13 hold a drive coil 12a and a magnet 13a which are actuators for image blur correction. In this embodiment, the image blur correction base member 12 holds the drive coil 12a, and the holding frame 13 holds the magnet 13a. However, the image blur correction base member 12 may hold the magnet, and the holding frame 13 may hold the drive coil.

  The shake detection unit 14 includes a shake detection sensor such as a gyro sensor. The shake detection unit 14 is disposed in the lens barrel 10. The shake detection unit 14 detects a shake in a direction (pitch and yaw direction) in which the optical axis O of the lens barrel 10 is inclined, and outputs a shake signal. A lens drive control unit 31 disposed in the lens barrel 10 controls energization to the drive coil 12a based on a shake signal from the shake detection unit 14, and in a direction perpendicular to the optical axis (see the O axis in the figure). The correction lens L1 is moved.

  Next, the second correction unit 21 and the drive control unit 30 provided in the camera body 20 will be described. Note that the second correction unit 21 may be disposed in the lens barrel 10 as long as the lens barrel and the imaging element are integrated. In that case, the drive control unit 30 may be on the lens side, or may be integrated with the lens drive control unit 31.

  The second correction unit 21 disposed in the camera body 20 includes a fixing plate 2 for the image sensor 1, a rotating member 3 for fixing the image sensor 1, a magnet 4, a base member 5, a coil 6, a ball 7, and a diagram. 2. It has the leaf | plate spring 8 shown in FIG. The rotating member 3 holds the ball 7 together with the base member 5 and can rotate around the optical axis O by the rolling friction of the ball 7. A detailed configuration will be described later.

  The posture detection unit 22 disposed in the camera body 20 includes a sensor that detects the posture of the camera. The posture detection unit 22 is, for example, an acceleration sensor that detects the inclination in the direction around the optical axis O (roll direction) of the camera. In addition, the posture detection unit 22 includes a shake detection sensor and a gyro sensor that detects a shake in at least the roll direction among the directions around the three axes (pitch, yaw, and roll direction).

  The drive control unit 30 disposed in the camera body 20 acquires a detection signal such as a shake signal or a posture signal from the posture detection unit 22. Then, the drive control unit 30 controls the current to flow through the coil 6 based on the output from the posture detection unit 22 so as to suppress the image shake or tilt in the roll direction caused by the shake or the posture change. When a current flows through the coil 6, a magnetic force is generated. When the magnet 4 facing the coil 6 receives this magnetic force, the rotating member 3 moves in the direction of force f in FIG. 3 or in the opposite direction (−f direction).

  Next, the second correction unit 21 as the image blur correction device of the present embodiment will be described in detail with reference to FIGS. FIG. 2 is an exploded perspective view of the second correction unit 21. FIG. 3 is a front view of the second correction unit 21 as viewed from the optical axis direction imaging device side. FIG. 4 is a perspective view of the rotating member 3. FIG. 5 is a perspective view of the rotating member 3 viewed from a direction different from that in FIG.

  FIG. 6 is a cross-sectional view taken along the line AA of the second correction unit 21 shown in FIG. FIG. 7 is a cross-sectional view taken along the line BB of the second correction unit 21 shown in FIG. FIG. 8 is a cross-sectional view taken along the line CC of the second correction unit 21 shown in FIG. In the following description, the optical axis direction subject side is referred to as the front side and the front side, and the optical axis direction imaging element side is referred to as the back side and the rear side based on the apparatus.

  The imaging device 1 images a subject through an imaging optical system provided in the lens barrel 10 and converts it into an electrical signal. The imaging device 1 is, for example, a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor.

  The optical axis O is preferably an axis that passes through the center of the imaging surface among the axes orthogonal to the imaging surface in terms of optical characteristics. The fixed plate 2 is a sheet metal that fixes the imaging device 1. The fixed plate 2 includes a holding portion 2a of the image sensor 1 and attachment portions 2b, 2c, and 2d to the rotating member 3.

  The rotating member 3 has an opening 3a (see FIG. 4) through which light from the imaging optical system provided in the lens barrel 10 passes. The rotating member 3 has an arrangement space for receiving the imaging element 1 and the fixed plate 2 holding the imaging element 1. The attachment portions 2b, 2c, and 2d of the fixed plate 2 are fastened and fixed to the attachment portions 3b, 3c, and 3d of the rotating member 3 by screws.

  The rotating member 3 has grooves 3h, 3i, and 3j (see FIGS. 4 and 5) formed in a slope shape on the outer peripheral portion. As shown in FIGS. 6 and 8, these groove portions 3h, 3i, and 3j have inclined surfaces whose widths become narrower as they become deeper. The grooves 3h, 3i, and 3j have two inclined surfaces so as to sandwich the ball 7. Specifically, the grooves 3h, 3i, and 3j are formed in the imaging surface direction (radial direction) and the optical axis direction of the ball 7 (first ball 7h, second ball 7i, and third ball 7j) as movable support members. Slope shape that restricts movement.

  These groove portions 3h, 3i, and 3j are formed so that the grooves extend in the direction around the optical axis. The grooves 3h, 3i, and 3j extend in the direction around the optical axis, so that the rotation member 3 can be rotated in the direction around the optical axis with respect to the base member 5 via the ball 7.

  The rotating member 3 holds a magnet 4. The magnet 4 forms a coil 6 held by the base member 5 and an actuator for image blur correction. The base member may hold the magnet 4 and the rotating member 3 may hold the coil 6.

  The base member 5 is fixed to the camera body 20. The base member 5 has a storage portion 5 e for holding the coil 6. The coil 6 has a configuration in which a copper wire is wound around a bobbin, and is fixed to a storage portion 5 e in the base member 5. Further, the coil 6 is installed facing the magnet 4 held by the rotating member 3 with a predetermined interval.

  The base member 5 is formed with an opening 5a in the center of which the rotating member 3 is disposed. Further, the base member 5 has three ball receiving grooves 5h, 5i, and 5j for housing the balls 7 at substantially equal intervals around the opening of the opening 5a.

  The receiving grooves 5i and 5j that receive the balls 7 are formed so that the grooves extend in the direction around the optical axis, in the same manner as the grooves 3h, 3i, and 3j. The receiving grooves 5i, 5j, together with the grooves 3h, 3i, 3j, have a slope shape that restricts the movement of the ball 7 in the imaging surface direction (radial direction) and the optical axis direction. On the other hand, the receiving groove 5h has a slope shape provided along a direction perpendicular to the optical axis O. The receiving groove 5h is in contact with the first ball 7h.

  FIG. 6 is a cross-sectional view taken along the line AA of the second correction unit 21 shown in FIG. FIG. 7 is a cross-sectional view taken along the line BB of the second correction unit 21 shown in FIG.

  FIGS. 6 and 7 show the relationship between the groove 3 h of the rotating member 3, the receiving groove 5 h of the base member 5, the first ball 7 h, and the leaf spring 8. In the present embodiment, the receiving groove 5h has a different shape from the other receiving grooves 5i and 5j. In other words, the play between the turning member 3 and the receiving groove 5 is eliminated by urging the turning member 3 against the base member 5 by the leaf spring 8.

  The first ball 7 h supports the rotating member 3 so as to be rotatable with respect to the base member 5. As shown in FIG. 6, the leaf spring 8 (biasing member) urges the ball 7 h against the base member 5 at an angle θ with respect to the optical axis (axis perpendicular to the imaging surface) direction. Here, the angle θ of the urging force direction with respect to the optical axis direction is 0 ° <θ <90 °.

  As shown in FIG. 6, the force F <b> 1 acts on the first ball 7 h by the urging force of the leaf spring 8. The force F1 is divided into a component force F2 in the optical axis direction and a component force F3 in the imaging surface direction (radial direction). Here, since the movement of the first ball 7h in the imaging surface direction (radial direction) and the optical axis direction is restricted by the groove 3h, the force F1 can be divided into F2 and F3 without loss.

  The leaf spring 8 biases the rotating member 3 toward the base member 5 via the ball 7h by the component forces F2 and F3. That is, the leaf spring 8 urges the ball 7h so that component forces act in the optical axis direction and in the direction orthogonal to the optical axis (imaging surface direction).

  Specifically, the component force F2 of the force F1 in the optical axis direction presses the first ball 7h against the receiving groove 5h. Further, the component force F2 presses the rotating member 3 against the base member 5 in the optical axis direction. The component force F3 in the imaging surface direction of the force F1 presses the first ball 7h against the groove 3h and presses the rotating member 3 against the base member 5 in a direction (imaging surface direction) perpendicular to the optical axis.

  In the present embodiment, the receiving grooves 5i, 5j and the groove portions 3h, 3i, 3j are inclined. The receiving grooves 5i and 5j and the groove portions 3h, 3i, and 3j regulate the movement in the optical axis direction and the movement in the imaging surface direction by this inclined shape. However, an inclined shape (a receiving groove or a groove) may be provided only on one of the rotating member 3 and the base member 5.

  FIG. 8 is a cross-sectional view taken along the line CC of FIG. 3, and shows the relationship between the groove 3j of the rotating member 3, the receiving groove 5j of the base member 5, and the third ball 7j.

  The third ball 7j is disposed so as to be sandwiched between the groove 3j of the rotating member 3 and the ball receiving groove 5j of the base member 5. The rotating member 3 is urged in a direction perpendicular to the optical axis by a force F3 applied to the first ball 7h. Therefore, a component force F5 (shown in FIG. 3) which is a component force of the component force F3 receives the groove portion 3j via the third ball 7j and biases it to the groove 5j. Similarly, although not shown, a component force F4 (shown in FIGS. 3 and 8), which is a component force of the component force F3, biases the groove portion 3i to the groove 5i via the second ball 7i. Thereby, the rotation member 3 can regulate the play in the optical axis direction and the direction perpendicular to the optical axis (imaging surface direction).

  As described above, according to the present embodiment, the grooves (3h, 3i, 3j) and the ball 7 are brought into contact with each other by the force of the biasing member (leaf spring 8). By the component force F2 of the force F1 of the leaf spring 8, the play in the optical axis direction of the rotating member 3 with respect to the base member 5 can be eliminated. Moreover, the play F3 of the force F1 of the leaf spring 8 can eliminate backlash in the imaging surface direction (direction orthogonal to the optical axis) of the rotating member 3 with respect to the base member 5. Therefore, since the rotating shaft is unnecessary, the back side is not enlarged. Further, since the component force F2 and the component force F3 of the force F1 of the leaf spring 8 work, it is possible to prevent the rotating member 3 from rattling and affecting the image blur correction.

(Modification)
The present invention is not limited to the embodiment described above, and various modifications and changes shown below are possible, and these are also included in the technical scope of the present invention.

  (1) In the embodiment of the present invention, the image sensor 1 is moved only in the roll direction, and the movement in the linear direction is performed by the correction lens L1. Not limited to this, the base member 5 itself having the ball receiving grooves 5h, 5i, and 5j may be configured such that image blur correction can be performed in the pitch direction and the yaw direction.

  (2) In the embodiment of the present invention, the rotation center of the imaging device 1 and the rotation member 3 coincides with the optical axis О, but the center position is not limited to this, and another position is necessary as necessary. May be set. At that time, the drive control unit 30 may calculate an image blur caused by a deviation between the rotation center of the imaging element and the rotation member 3 and the optical axis O, and the first correction unit 11 may correct the image blur.

  (3) In the embodiment of the present invention, the number of leaf springs 8 is one. However, there may be two or more. Further, although there are three groove portions (3h, 3i, 3j), receiving grooves (5h, 5i, 5j) and balls (7h, 7i, 7j), there may be four or more each.

  The present invention can be used not only for a digital still camera whose main purpose is still image shooting but also for other forms of imaging devices such as video cameras and digital single-lens reflex cameras whose main purpose is moving image shooting. In addition, the present invention can be widely applied to electronic devices and optical devices equipped with the image blur correction mechanism of this embodiment, such as smartphones, tablet terminals, mobile phones, and game devices.

3h, 3i, 3j Groove 5h, 5i, 5j Receiving groove 7h, 7i, 7j Ball

Claims (7)

A base member;
A rotating member that holds a member that holds the image sensor;
A plurality of support members that are disposed between the rotating member and the base member and support the rotating member so as to be rotatable with respect to the base member about an axis orthogonal to the imaging surface of the imaging element; ,
Urging means for urging the support member against the rotating member and the base member;
An imaging apparatus comprising: a movement of the support member in an axial direction perpendicular to the imaging surface; and a regulating unit that regulates movement in the imaging surface direction.   The imaging apparatus according to claim 1, wherein the plurality of support members are a plurality of spherical members.   The imaging according to claim 2, wherein the spherical member is sandwiched between groove portions provided in at least one of the rotating member and the base member, and the groove portion has a shape that becomes narrower as the depth increases. apparatus.   The imaging apparatus according to claim 3, wherein the groove extends in a direction around the optical axis.   4. The device according to claim 1, wherein at least one of the plurality of support members supports the rotation member so as to be rotatable about an axis orthogonal to the imaging surface. 5. Imaging device.   The imaging apparatus according to claim 1, further comprising a driving unit configured to rotate the rotating member. Detecting means for detecting rotational shake about the axis;
The imaging apparatus according to claim 1, further comprising a drive control unit that drives the drive unit based on an output of the detection unit.

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