JP2008076646A - Shake correcting device and equipment equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shake correcting device easily assembled, and equipment equipped therewith. <P>SOLUTION: The shake correcting device includes: a first member 2 and a second member 20 provided to be opposed to each other and relatively moving to correct image blur; and a rolling body 42 having magnetic material and provided at an opposed part where the first and the second members 2 and 20 are opposed, and at least either the first member 2 or the second member 20 has magnetic material 51 at the opposed part where the rolling body 42 is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shake correction apparatus provided in a camera or the like and a device including the same.

  A camera capable of optical blur correction detects camera vibration caused by camera shake, etc., using a shake sensor, and based on the detection result, the direction of the anti-vibration lens that is part of the photographic optical system is perpendicular to the optical axis The image blur is corrected by driving the zoom lens, and a good captured image is obtained. In order to drive the anti-vibration lens smoothly, there is one in which a ball is interposed between the holding frame and the fixed portion of the anti-vibration lens so as to be able to roll (see, for example, Patent Document 1).

JP 2002-196383 A

  The above-described ball is made of, for example, stainless steel or ceramics. However, since these are all magnetic materials, if the magnet is in the vicinity in the assembly process, the ball is attracted to it and it is difficult to place it in a predetermined position.

The blur correction device according to the present invention includes a first member and a second member that are provided opposite to each other and move relatively to correct image blur, a magnetic material, and a first member and a second member. And at least one of the first member and the second member has a magnetic material in the facing portion where the rolling element is provided.
A magnet may be used as the magnetic material of the facing portion.
A recess may be provided in at least one of the first member and the second member, and the rolling element may be provided in the recess.
You may make it the force which approaches the center of a recessed part acts on a rolling element with the magnetic material of the said opposing part.
You may have an electromagnetic actuator as a drive source of the said relative movement.
Either one of the first member and the second member may include an anti-vibration lens.
Either one of the first member and the second member may include an image sensor.
An apparatus according to the present invention includes the above-described shake correction device.

  According to the present invention, it is possible to provide a shake correction device that is easy to assemble and a device including the same.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an exploded perspective view showing the structure of an optical blur correction device for a camera, FIG. 2 is a schematic view of a section taken along the line II-II, and FIG. 3 is a sectional view taken on a plane different from FIG.

  In FIG. 1, an anti-vibration lens 1 that forms a part of a photographing lens is held by a lens holding frame 2, and the lens holding frame 2 is supported so as to be movable in a direction perpendicular to the photographing optical axis L. The drive source of the anti-vibration lens 1 is a pair of voice coil motors (hereinafter referred to as VCM), and the lens holding frame 2 is driven in the vertical direction in the figure by one VCM and in the horizontal direction by the other VCM.

  Each VCM includes a drive magnet 11, a drive yoke 12 (FIG. 2), a coil 13, and a coil yoke 14. The driving magnet 11 and the driving yoke 12 are integrated and supported by a fixing member 21, and the coil yoke 14 is fixed to a fixing member 20 (see FIG. 3) on the front side of the lens holding frame 2. The coil 13 is supported by the lens holding frame 2 between the driving magnet 11 and the coil yoke 14. When a current is passed through the coil 13, an electromagnetic force is generated in a direction perpendicular to the current direction and the line of magnetic force according to Fleming's left-hand rule, and accordingly, the lens holding frame 2 integrated with the coil 13 is perpendicular to the optical axis L. Driven by.

  Further, the shake correction device has a pair of position detection devices for detecting the vertical and horizontal positions of the image stabilizing lens 1. Each position detection device includes a position detection magnet 31 and a position detection yoke 32 supported by the lens holding frame 2, and a Hall element 33 fixed to the fixing portion 20 (see FIG. 3). The position of the anti-vibration lens is detected from the output.

  In FIG. 3, the lens holding frame 2 is pressed against the fixing member 20 on the near side by the tension springs 41 provided at two locations via the balls 42 provided at three locations. Each ball 42 is inserted into a circular recess 22 a formed in the ball support portion 22 of the fixing member 20. In FIG. 4, each ball 42 can roll with respect to each of the rolling surface P <b> 1 in the recess 22 a and the rolling surface P <b> 2 of the lens holding frame 2. The lens holding frame 2 is restrained from undesired movement in the optical axis direction by the action of the tension spring 41, and can move smoothly in a direction perpendicular to the optical axis by rolling the ball 42.

  In FIG. 1, when performing blur correction control, the camera detects vertical and horizontal vibrations of the camera due to camera shake or the like with a pair of shake sensors (not shown). Based on the detection results and the detection outputs of the pair of position detection devices, the pair of VCMs causes the lens holding frame 2, that is, the image stabilization lens 1 to be perpendicular to the optical axis L (the direction in which image blur is canceled). To drive.

Next, the structure around the ball 42 described above will be described in detail with reference to FIG.
The higher the sphericity is, the better the ball 42 is, and since it always receives the pressing force of the spring 41, the ball 42 is required to have a certain degree of rigidity and a little secular change. Therefore, for example, stainless steel or ceramic balls 42 can be used.

  In the small shake correction device, the diameter of the ball 42 is as small as 1 mm or less, and the ball 42 is accommodated in the recess 22a as shown in FIG. 4 in order to prevent the ball 42 from being lost during assembly. However, as described in the section of the problem, stainless steel and ceramics, which are the materials of the ball 42, are magnetic materials, while the shake correction device is provided with two types of magnets 11 and 31, each having a concave portion. There is a possibility that the ball 42 placed in 22a may be undesirably attracted to the magnets 11 and 31.

  Therefore, in the present embodiment, the permanent magnet 51 is disposed in the recess 22 a that accommodates the ball 42, and the upper surface thereof is used as the rolling surface P <b> 1 of the ball 42. The magnet 51 has a disk shape having substantially the same diameter as the recess 22a, and is disposed on the bottom surface of the recess 22a by fitting. According to this, since the ball 42 is attracted to the magnet 51 in the recess 22a, the attraction to the magnets 11 and 31 is suppressed, and the structure of the shake correction device can be easily assembled. In the present embodiment, since the ball 42 is attracted to the magnet 51, the possibility that the ball 42 is detached from the recess 22a is reduced.

  FIG. 5 shows an example of the magnetized state of the magnet 51. In this case, since the centripetal force that tends to approach the center of the magnet 51 acts on the ball 42, there is an effect that the ball 42 can be prevented from colliding with the side wall of the recess 22a. If a control error occurs and the ball remains in contact with the side wall of the recess, it is necessary to reset the blur correction control. However, at the time of reset, the ball naturally exists at the center, and the recess side wall again Collision with is suppressed. Therefore, according to the shake correction device of the present embodiment, highly accurate shake correction control can be performed by suppressing the collision of the ball 42 with the recess side wall. Further, according to the present embodiment, at the time of blur correction control, the force that rolls the ball 42 from the side wall of the recess to the center side of the recess works by the magnet 51, so in a portion (rollable area) away from the side wall of the recess, The ball 42 can be controlled to roll.

  FIG. 6 shows another example of the magnetized state. In the example shown in FIG. 6, since the N pole and the S pole are arranged in a direction orthogonal to the optical axis L (see FIG. 3), a centripetal force stronger than that in the example shown in FIG. 5 can be obtained.

  Moreover, by making the upper surface of the magnet 51 into the rolling surface P1, the flatness of the rolling surface can be increased as compared with the conventional case where the bottom surface (resin surface) of the recess is used as the rolling surface, and smoother. Vibration-proof lens drive is realized. In particular, the bottom surface of the concave portion is a location where it is difficult to perform planar processing (polishing). However, when the magnet 51 is used, the flatness can be further improved because it can be fitted into the concave portion 22a after performing the planar processing. .

A modification is shown in FIGS.
FIG. 7 shows an example in which a yoke 52 is disposed on the bottom surface of the recess in order to increase the magnetic force. FIG. 8 shows an example in which a disk member 53 with a magnet 53a embedded in the center is fitted in the recess 22a, and FIG. 9 shows an example in which the magnet 54 is directly embedded in the center of the bottom of the recess. In any case, there is a possibility that a step is generated between the magnet and the surrounding portion. Therefore, the thin plate member 55 is disposed on the magnet, and the upper surface thereof is defined as a rolling surface P1. Thus, by arranging the magnet only at the central portion of the recess 22a, the collision of the ball 42 with the recess side wall can be further suppressed. FIG. 10 shows an example in which a magnet 56 whose center is thicker than the surrounding is embedded in the recess 22a, and this also increases the force that brings the ball 42 toward the center of the recess 22a.

  In the above, an example in which the ball 42 is magnetically attracted to the rolling surface P1 on the fixing member 20 (see FIG. 3) side is shown, but it may be magnetically attracted to the rolling surface P2 on the lens holding frame 2 side. In this case, the lens holding frame 2 is provided with a recess for accommodating the ball 24. The recess is not always necessary. The magnetic material is not limited to a magnet, and for example, a magnetic material having ferromagnetism is preferable. Furthermore, the magnetic material is preferably a hard magnetic material.

  The blur correction device as described above can be mounted on an observation optical device such as binoculars in addition to a photographing optical device such as a camera, an interchangeable lens for a camera, and a mobile phone with a camera function. In addition, there are two types of blur correction devices used for digital photographing devices, one that drives a vibration-proof lens as described above, and one that drives an image sensor that receives light transmitted through the lens and performs photoelectric conversion. The present invention can be similarly applied to an image sensor driving type blur correction apparatus. For example, in an image sensor driving type blur correction apparatus, an image sensor can be provided on one of the first and second members that move relative to each other.

The perspective view which shows the structure of the blurring correction apparatus in one Embodiment. The schematic diagram of the II-II line cross section of FIG. The schematic diagram of a cross section different from FIG. The figure which shows the structure around the ball | bowl of a blurring correction apparatus. The figure which shows an example of the magnetization state of a permanent magnet. The figure which shows the other example of the magnetization state of a permanent magnet. Sectional drawing which shows the example further provided with the yoke for strengthening magnetic force. Sectional drawing which shows the example which fitted the member which embedded the magnet in the center to the recessed part. Sectional drawing which shows the example which embedded the magnet in the bottom center of a recessed part. Sectional drawing which shows the example using the magnet with a thick center part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anti-vibration lens 2 Lens holding frame 11 Driving magnet 31 Position detection magnet 42 Ball 22 Ball support part 22a Recessed part 51, 53a, 55, 56 Magnet

Claims (8)

A first member and a second member which are provided opposite to each other and move relatively to correct image blur;
A magnetic material, including a rolling element provided in an opposing portion of the first member and the second member;
At least one of the first member and the second member has a magnetic material in the facing portion where the rolling element is provided. The blur correction device according to claim 1,
The blur correction device according to claim 1, wherein the magnetic material of the facing portion is a magnet. The blur correction device according to claim 1 or 2,
At least one of the first member and the second member has a recess in the facing portion,
The rolling correction device, wherein the rolling element is provided in the recess.   The blur correction device according to claim 3, wherein a force approaching a center of the concave portion acts on the rolling element by the magnetic material of the facing portion.   The blur correction apparatus according to claim 1, further comprising an electromagnetic actuator as a drive source for the relative movement.   6. The blur correction device according to claim 1, wherein one of the first member and the second member includes an anti-vibration lens.   The blur correction apparatus according to claim 1, wherein one of the first member and the second member includes an image sensor.   An apparatus comprising the shake correction apparatus according to claim 1.

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