JP2017161665A - Optical instrument having image shake correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image shake correction device that is advantageous for a moving frame to be smoothly movable without prying.SOLUTION: An image shake correction device corrects image shake by moving an image shake correction lens L3 based on a shift, with a movable member 13 that is movable with respect to a stationary member 11 in a plane perpendicular to the optical axis, and a guide member 12 that is movable with respect to the stationary member 11 in the plane perpendicular to the optical axis and guides the movable member 13 so as not to rotate in the plane perpendicular to the optical axis.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image shake correction apparatus and an optical apparatus using the same.

  2. Description of the Related Art Conventionally, in an optical apparatus such as a digital camera, there is an image blur correction apparatus for preventing image blur that is likely to occur due to camera shake during shooting. This image shake correction apparatus detects, for example, an image shake state in a lens barrel provided in an optical device by a detection unit, and based on the detection result, the image shake correction lens is within a plane orthogonal to the optical axis. It is common to have a configuration for shifting. In this case, the image blur is eliminated by moving the correction lens in the direction in which the camera shake is absorbed in the plane orthogonal to the optical axis and correcting the shift of the imaging position due to the camera shake.

  As such an image blur correction device, a lens using a guide bar for restricting the moving direction of the moving frame holding a part of the image blur correcting lens group of the optical system in two directions perpendicular to the optical axis direction. A lens barrel is known (Patent Document 1).

  In the image blur correction device of Patent Document 1, there is a first guide bar for guiding the pitch guide base in the yaw direction (lateral direction), and the first guide bar is fixed and held on the shift base. Therefore, the pitch guide base is configured to move only in the yaw direction along the first guide bar with respect to the shift base.

  There is also a second guide bar for guiding the moving frame in the pitch direction (vertical direction), and the second guide bar is fixed and held on the pitch guide base. Therefore, the moving frame is configured to move only in the pitch direction along the second guide bar with respect to the pitch guide base. With these configurations, the moving frame can move freely in the pitch direction and the yaw direction with respect to the shift base.

  In the image blur correction apparatus of Patent Document 1, the moving direction of the moving frame and the pitch guide base is regulated by the guide bar, so that there is a problem that the friction load is high. Therefore, in order to reduce the friction load, the present applicant has applied for an image blur correction device using rolling friction balls instead of sliding friction guide bars in the configuration of the moving frame, pitch guide base, and shift base. is there.

  In the image blur correction device for which an application has been filed, V-grooves extending in the yaw direction are formed on opposing surfaces of the pitch guide base and the shift base in order to guide the pitch guide base in the yaw direction (lateral direction). A first V groove is formed on the shift base side, and a second V groove is formed on the pitch guide base side. The first rolling ball is held by the first guide portion including the first V groove and the second V groove. Therefore, the pitch guide base is configured to move only in the yaw direction along the first guide portion with respect to the shift base.

  Further, in order to guide the moving frame in the pitch direction, V-grooves extending in the pitch direction are formed on the opposing surfaces of the moving frame and the pitch guide base. A third V groove is formed on the pitch guide base side, and a fourth V groove is formed on the moving frame side. The second rolling ball is held by the second guide portion including the third V groove and the fourth V groove. Therefore, the moving frame is configured to move only in the pitch direction along the second guide portion with respect to the pitch guide base.

  With these configurations, the moving frame can move freely in the pitch direction and the yaw direction with respect to the shift base.

JP 2009-192899

  The image blur correction device for which an application has been filed has three first rolling balls held by a first guide portion comprising a first V groove and a second V groove, and a second guide portion comprising a third V groove and a fourth V groove. Three second rolling balls are held. However, when all of the portions that receive the three rolling balls are V-grooves, double fitting is required. Therefore, it is necessary to receive the balls in one flat groove.

  At this time, in the first rolling ball and the second rolling ball, it is necessary to make two V-grooves and one flat groove respectively, but depending on the combination of which ball position the V-groove and the flat groove are arranged, When the pitch guide base and the moving frame move, a problem arises in that there is a possibility that the twisting force will work and it will not move smoothly.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image blur correction device that is advantageous for smooth movement without twisting when the pitch guide base and the moving frame move.

In order to achieve the above object, an image shake correction apparatus according to the present invention includes:
An image stabilization lens;
A movable member that holds the image blur correction lens and is movable relative to the fixed member in a plane perpendicular to the optical axis;
A guide member that is movable in a plane perpendicular to the optical axis with respect to the fixed member and guides the movable member so as not to rotate in a plane perpendicular to the optical axis;
Three first rolling balls sandwiched between the fixing member and the guide member in a rollable manner;
Three second rolling balls sandwiched between the guide member and the movable member in a rollable manner;
A first guide part for holding the first rolling ball so as to roll;
A second guide part for holding the second rolling ball so as to roll;
Drive means for driving the movable member in a direction perpendicular to the optical axis with respect to the fixed member;
A shake correction device having
The first rolling ball can roll only in a first direction perpendicular to the optical axis;
The second rolling ball can roll only in a second direction that is perpendicular to the optical axis and different from the first direction,
The first guide part is composed of two V-grooves and one flat groove extending in the first direction,
The second guide part is composed of two V grooves and one flat groove extending in the second direction.

  According to the present invention, when the pitch guide base and the moving frame are movable, it is possible to provide an image blur correction device that is advantageous for smooth movement without twisting.

Sectional view showing the configuration of the lens barrel FIG. 3 is an assembled perspective view of the image shake correction apparatus according to the first embodiment when viewed from the subject side. FIG. 3 is an assembled perspective view of the image shake correction apparatus according to the first embodiment when viewed from the image plane side. The front view when the 1st guide part is holding the 1st rolling ball in Example 1. Sectional drawing which shows the structure of a 1st guide part V groove (AA sectional drawing in FIG. 4) Sectional drawing which shows the structure of a 1st guide part flat groove (BB sectional drawing in FIG. 4) The front view when the 2nd rolling ball holds the 2nd rolling ball in Example 1. Sectional drawing which shows the structure of a 2nd guide part V groove (CC sectional drawing in FIG. 7) Sectional drawing which shows the structure of a 2nd guide part flat groove (DD sectional drawing in FIG. 7)

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[Example 1]
First, in describing the image blur correction apparatus according to the embodiment of the present invention, the configuration of a lens barrel in which the image blur correction apparatus is installed will be described as an example. Note that this lens barrel is employed in an imaging apparatus (optical apparatus) such as a digital still camera or a video camera. In each of the following drawings, the Z axis is taken in the direction of the subject in the optical axis direction of the lens barrel, the Y axis is taken in the vertical direction (pitch direction) in the vertical plane with respect to the Z axis, and the horizontal direction (yaw direction) ) Taking the X axis.

  FIG. 1 is a schematic cross-sectional view showing the configuration of the lens barrel 1.

  The lens barrel 1 has a first holder 2 and a second holder 3 having a substantially cylindrical shape. Further, the lens barrel 1 is formed of a convex-concave convex / concave convex optical element group including a first group lens L1, a second group lens L2, a third group lens L3, and a fourth group lens L4. And an imaging device 4.

  The first holder 2 is a fixed lens barrel positioned in the front portion of the lens barrel 1 in the Z-axis direction, and includes a first group lens L1 and a second group lens L2. The first group lens L1 is an optical element held by the first fixed frame 5 and is positioned at the front portion of the lens barrel 1 and is screwed to the first holder 2. The second group lens L2 is an optical element that is held by the first moving frame 6 inside the first holder 2 and performs a zooming operation by moving in the optical axis direction. The first holder 2 has a zoom motor (not shown) for driving the first moving frame 6 and a first guide bar and a second guide bar (not shown) extending in the Z-axis direction.

  The zoom motor has a lead screw coaxial with the rotating rotor, and the second group lens L2 is moved in the optical axis direction by rotating the lead screw meshed with the rack attached to the first moving frame 6 by the rotor. Moving. The first guide bar supports the first moving frame 6 so as to be movable in the Z-axis direction, while the second guide bar is engaged with the first moving frame 6 so that the first holder of the first moving frame 6 is engaged. 2 to regulate the rotation in the circumferential direction. Further, although not shown, the first holder 2 optically detects the movement of the light shielding portion formed in the first moving frame 6 in the optical axis direction, so that the second group lens L2 is at the reference position. A photo interrupter used as a zoom reset switch for detecting a certain event is provided.

  The second holder 3 is a fixed barrel that is connected to the first holder 2 with screws and is positioned at the rear of the lens barrel 1, and includes a third group lens L 3, a fourth group lens L 4, and an aperture device 7. And the image sensor 4. The third group lens L3 is held by a shift unit 8 as a drive unit of an image shake correction apparatus installed inside the second holder 3, and performs image shake correction by moving in a plane perpendicular to the optical axis. It is an optical element. The fourth group lens L4 is an optical which is held by a second moving frame 9 inside the second holder 3 and moves in the optical axis direction to perform a focusing operation while facing an imaging surface of the imaging element 4 described later. It is an element.

  The second holder 3 includes a focus motor (not shown) for driving the second moving frame 9, and a third guide bar and a fourth guide bar 10 (not shown) extending in the Z-axis direction. The focus motor has a lead screw coaxial with the rotating rotor, and the fourth group lens L4 is moved in the optical axis direction by rotating the lead screw meshed with the rack attached to the second moving frame 9 by the rotor. Moving. The third guide bar supports the second moving frame 9 so as to be movable in the Z-axis direction, while the fourth guide bar 10 is engaged with the second moving frame 9 so that the second moving frame 9 is second. The circumferential rotation within the holder 3 is restricted.

  Further, although not shown, the second holder 3 optically detects the movement of the light shielding portion formed in the second moving frame 9 in the optical axis direction, so that the fourth group lens L4 is brought to the reference position. A photo interrupter used as a focus reset switch for detecting the presence is provided. The aperture device 7 is a device that changes the aperture diameter of the optical system by installing an aperture blade between the front lens constituting the second group lens L2 and the rear lens constituting the third group lens L3. is there. In the present embodiment, the aperture diameter is changed by moving two diaphragm blades in opposite directions with one motor.

  The second holder 3 includes a holding structure that holds the image sensor 4. The imaging device 4 is an imaging unit that photoelectrically converts subject images formed by the lenses L1 to L4 of the first to fourth groups. As this image sensor 4, a CMOS (Complementary Metal Oxide Semiconductor) image sensor is employed in the present embodiment. Note that other types of image pickup devices such as a CCD (Charge Coupled Device) image sensor may be used as the image pickup device 4. Although not shown, the imaging element 4 is connected to a main board in the imaging apparatus having the lens barrel 1 through various wirings.

  Next, the image shake correction apparatus according to the present embodiment will be described.

  The image blur correction apparatus is a shift unit 8. 2 and 3 are exploded perspective views showing components of the shift unit 8 when viewed from the subject side and when viewed from the image plane side.

  As described above, the shift unit 8 is positioned inside the second holder 3 and is installed with screws. The shift unit 8 includes a shift base 11, a pitch guide base 12, and a shift movement frame 13.

  The shift base 11 is a main body of the shift unit 8 and guides a holding portion that holds a coil of an actuator, which will be described later, and a first rolling ball 14 that allows the pitch guide base 12 to move only in the yaw direction. And a first V-groove 15 extending in the vertical direction.

  The pitch guide base 12 has a second V groove 16 and a first flat groove 26 extending in the yaw direction for guiding the first rolling ball 14 on a surface facing the shift base 11. A surface facing the shift moving frame 13 has a third V groove 18 extending in the pitch direction for guiding the second rolling ball 17 that allows the shift moving frame 13 to move only in the pitch direction. A magnet 20 serving both for driving and for position detection is insert-molded. The magnet 20 is disposed at a position inclined by 45 degrees from the optical axis center with respect to the optical axis orthogonal plane. Further, since the magnet 20 is insert-molded in the pitch guide base 12, the relative positional relationship with the pitch guide base 12 does not shift.

  The shift moving frame 13 is a part that holds a third lens unit L3 that is an image shake correction lens (anti-vibration optical element) and is displaced in a direction perpendicular to the optical axis in order to correct camera shake. And a fourth V-groove 19 and a second flat groove 27 extending in the pitch direction for guiding the second rolling ball 17 on the surface facing the pitch guide base 12.

  Here, the force for bringing the first rolling ball 14 into contact with the first V groove 15 provided in the shift base 11 and the second V groove 16 provided in the pitch guide base 12 and the first flat groove 26, and the second The force for bringing the rolling ball 17 into contact with the fourth V groove 19 and the second flat groove 27 provided in the third V groove 18 provided in the pitch guide base 12 and the shift moving frame 13 is a spring biasing force by the coil spring 21. is there. The coil spring 21 is configured to be hooked on the shift base 11 on one side and the shift movement frame 13 on the other side, and generates a force to be sandwiched between the shift base 11 and the shift movement frame 13 with the pitch guide base 12 as an intermediate member. Have a role to play.

  The yaw direction drive coil 22 is bonded and fixed to the shift base 11 with an adhesive (not shown). Further, the pitch direction drive coil 23 is bonded and fixed to the shift moving frame 13 with an adhesive (not shown). Both the yaw direction drive coil 22 and the pitch direction drive coil 23 are disposed at positions facing the magnet 20 described above in a state inclined by 45 degrees from the optical axis center with respect to the optical axis orthogonal plane. The magnet 20 is two-pole magnetized in the L3a direction with respect to the surface facing the yaw direction driving coil 22, and is also two-pole magnetized in the L3a direction with respect to the surface facing the pitch direction driving coil 23. It is configured.

  The direction of L3a has an inclination of 45 degrees with respect to both the pitch direction and the yaw direction, and is a direction in which driving means including the magnet 20, the yaw direction drive coil 22, and the pitch direction drive coil 23 is arranged. Here, when the yaw direction drive coil 22 is energized, a drive force in the L3a direction is generated between the yaw direction drive coil 22 and the magnet 20. This driving force is controlled by the magnitude and direction (polarity) of the current supplied to the yaw direction driving coil 22. Since the yaw direction drive coil 22 is bonded and fixed to the shift base 11 as a fixing member, the drive force acts as a force for moving the pitch guide base 12.

  At this time, the direction of the driving force is the direction of L3a. However, as described above, the pitch guide base 12 is configured to be movable only in the yaw direction with respect to the shift base 11, so that driving in the L3a direction is performed. The component force in the yaw direction acts on the pitch guide base 12 to drive only in the yaw direction. When the pitch direction driving coil 23 is energized, a driving force in the L3a direction is generated between the pitch direction driving coil 23 and the magnet 20. This driving force is controlled by the magnitude and direction (polarity) of the current supplied to the pitch direction driving coil 23.

  The pitch direction drive coil 23 is fixed to the shift moving frame 13 and the position of the pitch guide base 12 is controlled by energizing the yaw direction drive coil 20 as described above. It works as a force to move the moving frame 13. At this time, the driving force direction is the direction of L3a. However, as described above, the shift moving frame 13 is configured to be movable only in the pitch direction with respect to the pitch guide base 12, so that the L3a direction The component force in the pitch direction of the driving force acts on the shift movement frame 13 to drive only in the pitch direction. That is, the shift moving frame 13 is configured to be freely movable in the pitch direction and the yaw direction with respect to the shift base 11.

  The yaw direction position detection sensor 24 is fixedly arranged inside the yaw direction drive coil 22, and the pitch direction position detection sensor 25 is fixedly arranged inside the pitch direction drive coil 23. Both the yaw direction position detection sensor 24 and the pitch direction position detection sensor 25 use Hall elements, for example. As described above, when the position detection sensors for the pitch direction and the yaw direction are arranged, and the position displacement of the magnet 20 with respect to the position detection sensor occurs, the magnetic flux changes according to the position displacement, and according to the magnitude of the magnetic flux from the magnet 20. Thus, the position detection can be performed by outputting the electrical signal of the position detection sensor.

  Next, the operation of the image shake correction apparatus according to Example 1 of the present embodiment will be described.

  FIG. 4 is a front view of the first guide portion including the first V groove 15, the second V groove 16, and the first flat groove 26. The first guide portion further includes a first guide portion V groove 28 including a first V groove 15 and a second V groove 16, a first guide portion flat groove 29 including a first V groove 15 and a first flat groove 26. FIG. 5 is a cross-sectional view of the first guide portion V-groove 28, and FIG. 6 is a cross-sectional view of the first guide portion flat groove 29.

  As shown in FIG. 4, when the coordinate axes are taken in the L3a direction and the L3b direction orthogonal to the L3a direction, the divided regions are referred to as a region 1, a region 2, a region 3, and a region 4, respectively. When divided in this way, region 1 is a region where driving means exists in the pitch direction from the optical axis center, region 2 is a region where driving means does not exist in the yaw direction from the optical axis center, and region 3 is a pitch direction from the optical axis center. In FIG. 4, the area where the driving means does not exist and the area 4 are areas where the driving means exist in the yaw direction from the center of the optical axis.

  As shown in FIG. 4, the first guide portion that holds the three first rolling balls 14 to prevent double fitting has two first guide portion V-grooves 28 and first guide portion flat grooves 29. Is provided in one place. The first guide portion V-groove 28 exists in the regions 1 and 4, and the first guide portion flat groove 29 exists in the region 3. Since the first guide portion V-groove 28 is present in the region 1 and the region 4, the driving means is arranged in the middle of the two first guide portion V-grooves 28 in the pitch direction and the yaw direction. The pitch guide base 12 is smoothly moved without being twisted by the driving force in the yaw direction.

  If the first guide portion V-groove 28 is present in the region 3 and the region 4 and the first guide portion flat groove 29 is present in the region 1, the first guide portion V-groove 28 is intermediate between the two first guide portion V-grooves 28 in the pitch direction. Since the driving means cannot be arranged, the pitch guide base 12 can be easily moved by the driving force in the yaw direction.

  FIG. 7 shows a front view of the second guide portion including the third V groove 18, the fourth V groove 19, and the second flat groove 27. The second guide portion further includes a second guide portion V-groove 30 including a third V groove 18 and a fourth V groove 19, a second guide portion flat groove 31 including a third V groove 18 and a second flat groove 27. FIG. 8 shows a cross-sectional view of the second guide portion V-groove 30. FIG. 9 shows a cross-sectional view of the second guide portion flat groove 31.

  Region 1, region 2, region 3, and region 4 shown in FIG. 7 are the same as described above. As shown in FIG. 7, the second guide portion that holds the three second rolling balls 17 to prevent double fitting has two second guide portion V-grooves 30 and second guide portion flat grooves 31. Is provided in one place. The second guide portion V-groove 30 exists in the regions 1 and 4, and the second guide portion flat groove 31 exists in the region 2. Since the second guide portion V-groove 30 exists in the region 1 and the region 4, the driving means is arranged in the middle of the two second guide portion V-grooves 30 in the pitch direction and the yaw direction. The shift moving frame 13 is smoothly moved without being twisted by the driving force in the pitch direction.

  If the second guide portion V-groove 30 is present in the region 2 and the region 4 and the second guide portion flat groove 31 is present in the region 1, the second guide portion V-groove 30 is intermediate between the two second guide portion V-grooves 30 in the pitch direction. Since the drive means cannot be arranged, the shift movement frame 13 can be easily moved by the driving force in the pitch direction.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 lens barrel, 2 first holder, 3 second holder, 4 image sensor, 5 first fixed frame,
6 first moving frame, 7 aperture device, 8 shift unit, 9 second moving frame,
10 fourth guide bar, 11 shift base, 12 pitch guide base,
13 shift moving frame, 14 first rolling ball, 15 first V groove, 16 second V groove,
17 2nd rolling ball, 18 3rd V groove, 19 4th V groove, 20 magnet,
21 coil spring, 22 yaw direction drive coil, 23 pitch direction drive coil,
24 yaw direction position detection sensor, 25 pitch direction position detection sensor, 26 first flat groove,
27 2nd flat groove, 28 1st guide part V groove, 29 1st guide part flat groove,
30 2nd guide part V groove, 31 2nd guide part flat groove, L1 1st group lens,
L2 2nd lens group, L3 3rd lens group, L4 4th lens group

Claims (2)

An image stabilization lens;
A movable member that holds the image blur correction lens and is movable relative to the fixed member in a plane perpendicular to the optical axis;
A guide member that is movable in a plane perpendicular to the optical axis with respect to the fixed member and guides the movable member so as not to rotate in a plane perpendicular to the optical axis;
Three first rolling balls sandwiched between the fixing member and the guide member in a rollable manner;
Three second rolling balls sandwiched between the guide member and the movable member in a rollable manner;
A first guide part for holding the first rolling ball so as to roll;
A second guide part for holding the second rolling ball so as to roll;
Drive means for driving the movable member in a direction perpendicular to the optical axis with respect to the fixed member;
A shake correction device having
The first rolling ball can roll only in a first direction perpendicular to the optical axis;
The second rolling ball can roll only in a second direction that is perpendicular to the optical axis and different from the first direction,
The first guide part is composed of two first guide part V-grooves extending in the first direction and one first guide part flat groove,
2. The image blur correction device according to claim 1, wherein the second guide portion includes two second guide portion V-grooves extending in the second direction and one second guide portion flat groove. The vertical direction on the plane perpendicular to the optical axis of the image blur correction lens is the pitch direction,
When the horizontal direction on the surface perpendicular to the optical axis of the image blur correction lens is the yaw direction,
The drive means is disposed at a position having an inclination of 45 degrees with respect to both the pitch direction and the yaw direction.
The two first guide part V-grooves and the two second guide part V-grooves are
The image blur correction apparatus according to claim 1, wherein the image blur correction apparatus is disposed at a position having the driving unit in the middle in the pitch direction and the yaw direction.