JP2009258388A - Image stabilization apparatus, imaging apparatus and optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and power-saving image stabilization apparatus capable of reducing a positional deviation of an image formed on an image plane which may be caused by the weight of first and second correction lenses. <P>SOLUTION: The image stabilization apparatus includes: a first driven means including the first correction lens 10a; a second driven means including the second correction lens 10b having power opposite to that of the first correction lens; supporting means 15a, 15d, 16a and 16d configured to support the first driven means and the second driven means movably on a plane perpendicular to an optical axis; a driving means comprising a first coil 18a and a second magnet provided in the first driven means, and a second coil and a first magnet 17a provided in the second driven means, and configured to drive the first driven means and the second driven means in directions opposite to each other on the plane perpendicular to the optical axis by making the first coil and the first magnet and the second coil and the second magnet opposed to each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image shake correction apparatus that corrects an image shake, an imaging apparatus having the image shake correction apparatus, and an optical apparatus.

  With current cameras, all important tasks such as determining exposure and focusing are automated, and there is very little chance of shooting failure even for people who are not familiar with camera operation. Recently, a system that corrects image blur due to camera shake applied to the camera has been studied, and there is almost no cause of a photographer's shooting mistake.

  Here, a system for correcting image blur due to camera shake will be briefly described.

  The camera shake at the time of shooting is usually a vibration of 1 Hz to 10 Hz as a frequency. As a basic idea to make it possible to take pictures without image blur even when such camera shake occurs at the shutter release time, camera shake due to camera shake is detected, and image blur correction is performed according to the detected value. The lens for use (hereinafter, correction lens) must be displaced. Therefore, in order to take a picture that does not cause image shake even if camera shake occurs, firstly, camera shake (vibration) is accurately detected, and second, optical axis change due to camera shake is corrected. Is required.

  In principle, camera shake detection detects acceleration, angular acceleration, angular velocity, angular displacement, etc., and the camera is equipped with a shake detection unit that appropriately calculates the output for image shake correction due to camera shake. Can be done. Then, based on the detected shake information, a correction lens for decentering the photographing optical axis is driven to perform image shake correction.

  FIG. 16 is an external view of a digital compact camera having an image blur correction function. Image blur correction is performed for camera vertical shake and horizontal shake indicated by arrows 42p and 42y with respect to the optical axis 41. FIG. In the camera body 43, 43a is a release button, 43b is a mode dial (including a main switch), and 43c is a retractable strobe.

  In FIG. 16, a liquid crystal monitor is provided on the back surface of the camera body 43, which is arranged on the back surface of the camera body 43, so that an image taken by an image sensor described later can be confirmed. The photographer confirms the composition of the photographed image on the liquid crystal monitor and then performs photographing.

  FIG. 17 is a perspective view showing a configuration of a portion related to an image shake correction apparatus provided in the digital compact camera of FIG. 16, and 44 is an image sensor. Reference numeral 53 denotes an image blur correction apparatus that drives the correction lens 52 freely in the directions of arrows 58p and 58y to correct image blur in the directions of arrows 42p and 42y in FIG. Reference numerals 45p and 45y denote shake detection units such as angular velocity meters and angular accelerometers that detect shakes around the arrows 46p and 46y, respectively. Outputs of the shake detection units 45p and 45y are converted into drive target values for the correction lens 52 via calculation units 47p and 47y described later, and input to a coil of an image shake correction device to perform image shake correction.

  FIG. 18 is a block diagram showing details of the calculation units 47p and 47y shown in FIG. 17. Since the calculation units 47p and 47y have the same configuration, only the calculation unit 47p will be described in FIG.

  The calculation unit 47p includes the following components surrounded by a one-dot chain line. A DC cut filter / amplifier 48p, a low-pass filter / amplifier 49p, an analog-to-digital converter (hereinafter referred to as A / D converter) 410p, a camera microcomputer 411, and a driver 420p are provided. The camera microcomputer 411 includes a storage unit 412p, a differential unit 413p, a DC cut filter 414p, an integration unit 415p, a sensitivity adjustment unit 416p, a storage unit 417p, a differential unit 418p, and a PWM duty conversion unit 419.

  Here, a vibration gyro that detects a camera shake angular velocity is used as the shake detection unit 45p. The vibration gyro is driven in synchronization with the camera main switch being turned on, and starts detecting a shake angular velocity applied to the camera.

  The shake signal from the shake detection unit 45p is appropriately amplified while the DC bias component superimposed on the signal is cut by the DC cut filter / amplification unit 48p formed of an analog circuit. The DC cut filter / amplifier 48p has a frequency characteristic for cutting a signal having a frequency of 0.1 Hz or less, and does not affect the handshake frequency band of 1 to 10 Hz applied to the camera. However, when the characteristic of cutting 0.1 Hz or less is used in this way, there is a problem that it takes nearly 10 seconds until the DC component is completely cut after the shake signal is input from the shake detection unit 45p. Therefore, the time constant of the DC cut filter / amplifier 48p is reduced (for example, a characteristic for cutting a signal having a frequency of 10 Hz or less) until 0.1 second, for example, after the camera main switch is turned on. In this way, the DC component is cut in a short time of about 0.1 seconds, and then the time constant is increased so that only the frequency of 0.1 Hz or less is cut. The signal is not degraded.

  The output signal of the DC cut filter / amplifier 48p is appropriately amplified in accordance with the A / D resolution by a low-pass filter / amplifier 49p formed of an analog circuit, and high-frequency noise superimposed on the shake angular velocity signal is cut. . This is to avoid a reading error caused by noise in the shake angular velocity signal during sampling at the A / D converter 410p when the shake angular velocity signal is input to the camera microcomputer 411.

  The output signal of the low-pass filter / amplifier 49p is sampled by the A / D converter 410p and taken into the camera microcomputer 411.

  Although the DC bias component is cut by the DC cut filter / amplifier 48p, the DC bias component is again superimposed on the shake angular velocity signal by the subsequent amplification of the low pass filter / amplifier 49p. Therefore, it is necessary to perform DC cut again in the camera microcomputer 411.

  Therefore, for example, the shake angular velocity signal sampled 0.2 seconds after the camera main switch is turned on is stored in the storage unit 412p, and the DC component is cut by obtaining the difference between the stored value and the shake angular velocity signal by the differential unit 413p. Do. In this operation, only a rough DC component can be cut (the shake angular velocity signal stored 0.2 seconds after the camera main switch is turned on includes not only the DC component but also the actual camera shake. For). For this purpose, a sufficient DC component is cut by a DC cut filter 414p composed of a digital filter in the subsequent stage. This DC cut filter 414p can also change the time constant in the same manner as the analog DC cut filter / amplifier unit 48p, and spends 0.2 seconds after the camera main switch is turned on for another 0.2 seconds. Is gradually increased. Specifically, the DC cut filter 414p has a filter characteristic that cuts a frequency of 10 Hz or less when 0.2 seconds have elapsed since the main switch was turned on. Then, the frequency cut by the filter every 50 msec is lowered from 5 Hz → 1 Hz → 0.5 Hz → 0.2 Hz.

  However, if the photographer presses the shutter release button halfway (switch sw1 is turned on) during the above operation and performs photometric distance measurement, there is a possibility that the image will be taken immediately, and time constant is changed over time. Sometimes things are undesirable. Therefore, in such a case, the time constant change is stopped halfway according to the shooting conditions. For example, when the shutter speed is found to be 1/60 from the photometric result, and the focal length is 150 mm, the anti-vibration accuracy is not required so much, so the DC cut filter 414p cuts the frequency of 0.5 Hz or less. Completed when the time constant is changed. That is, the amount of time constant change is controlled by the product of the shutter speed and the focal length. As a result, the time for changing the time constant can be shortened, and the photo opportunity can be prioritized. Of course, when the shutter speed is faster or the focal length is shorter, the characteristic of the DC cut filter 414p is completed when the time constant is changed to the characteristic of cutting a frequency of 1 Hz or less. When the shutter speed is slower and the focal length is longer, shooting is prohibited until the time constant is completely changed.

  The integration unit 415p starts integrating the signal of the DC cut filter 414p and converts the angular velocity signal into an angle signal. The sensitivity adjustment unit 416p appropriately amplifies the integrated angle signal according to the focal length and subject distance information of the camera at that time, and converts it so that the driven unit of the appropriate amount shake correction device is driven according to the shake angle. . Since the photographic optical system changes due to zoom and focus, and the optical axis decentering amount changes with respect to the driving amount of the driven part, it is necessary to perform this correction.

  By driving the shutter release button halfway, the mechanical portion of the image blur correction device (hereinafter simply referred to as the image blur correction device) starts to be driven. At this point, care must be taken so that the image blur correction operation by the image blur correction device does not start abruptly.

  The storage unit 417p and the differential unit 418p are provided for this measure. The storage unit 417p stores the deflection angle signal of the integration unit 415p when the shutter release button is half-pressed. The differential unit 418p obtains the difference between the signal of the integration unit 415p and the signal of the storage unit 417p. Therefore, the two signal inputs of the differential unit 418p are equal when the shutter release button is half-pressed, and the drive target value signal of the differential unit 418p is zero. However, the output is continuously performed from zero thereafter. The storage unit 2 serves as an origin of the integration signal when the shutter release button is half-pressed. As a result, the image blur correction device is not driven rapidly.

  The target value signal from the differential unit 418p is input to the PWM duty changing unit 419p. If a voltage or current corresponding to the shake angle is applied to the coil of the image shake correction apparatus, the correction lens 52 is driven corresponding to the shake angle. However, PWM drive is desirable for power saving of the image blur correction device and power saving of the drive transistor of the coil.

  Therefore, the PWM duty changing unit 419p changes the coil driving duty in accordance with the target value. For example, when the target value of the differential unit 418p is “2048” in PWM with a frequency of 20 KHz, the duty is zero, and when the target value is “4096”, the duty is 100, and the duty is determined according to the target value by equally dividing the duty. It should be noted that the duty is determined not only by the target value but also finely controlled by the shooting conditions of the camera at that time (temperature, camera posture, battery state) so that image blur correction can be performed with high accuracy.

  The output of the PWM duty changing unit 419p is input to a known driving unit 420p such as a PWM driver, and the output of the driving unit 420p is applied to the coil of the image blur correction device to perform image blur correction. The drive unit 420p is turned on in synchronism with the time when 0.2 seconds have elapsed after the shutter release button is half-pressed (switch sw1 is turned on).

  Although not shown in the block diagram of FIG. 18, when the photographer pushes the release button of the camera (sw2 is turned on) and exposure is started, image blur correction is continued as it is. Image quality deterioration due to shake can be prevented.

  The image blur correction by the image blur correction device is continued as long as the release button is half-pressed. When the half-press is released, the storage unit 417p stops storing the signal of the sensitivity adjustment unit 416p (sampling state). become). Therefore, the signals of the sensitivity adjustment unit 416p and the storage unit 417p input to the differential unit 418p are equal, and the output of the differential unit 418p is zero. Therefore, a zero drive target value is input to the image blur correction device, and image blur correction is not performed.

  As long as the main switch of the camera is not turned off, the integration unit 415p continues to integrate, and the storage unit 417p stores the new integration output (signal hold) again when the next release button is pressed halfway. The shake detection unit 45p is turned off when the main switch is turned off, and the image stabilization sequence ends.

  When the signal of the integration unit 415p becomes larger than a predetermined value, it is determined that the camera is panned, and the time constant of the DC cut filter 414p is changed. For example, a characteristic that cuts a frequency of 0.2 Hz or less is changed to a characteristic that cuts a frequency of 1 Hz or less, and the time constant is restored again in a predetermined time. At this time, the amount of time constant change is also controlled by the magnitude of the output of the integrator 415p. That is, when the output exceeds the first threshold, the characteristic of the DC cut filter 414p is set to a characteristic that cuts 0.5 Hz or less, and when the output exceeds the second threshold, the characteristic is cut to 1 Hz or less and exceeds the third threshold. In some cases, the characteristic is to cut below 5 Hz.

  Further, when the output of the integration unit 415p becomes very large (for example, when an extremely large angular velocity such as camera panning occurs), the integration unit 415p is temporarily reset to prevent computation saturation (overflow). ing.

  In FIG. 18, a DC cut filter / amplifier 48p and a low-pass filter / amplifier 49p are provided in the arithmetic unit 47p, but it goes without saying that these may be provided in the shake detector 45p.

  FIGS. 19A to 19C are diagrams showing the configuration of the image shake correction apparatus. Specifically, FIG. 19A is a front view of the image shake correction apparatus, and FIG. 19B is FIG. 19A. FIG. 19C is a cross-sectional view taken along the line AA of FIG. 19A.

  In FIG. 19, the correction lens 52 (as shown in the cross-sectional view of FIG. 19C) is photographed by the two lenses 52 a and 52 b fixed to the support frame 53 and the lens 52 c fixed to the base plate 54. The optical system group) is fixed to the support frame 53. A yoke 55 made of a ferromagnetic material is attached to the support frame 53, and permanent magnets 56p, 56y such as neodymium are attracted and fixed to the back surface (surface on the ground plate 54 side) of the yoke 55. Further, the three support shafts 53 a extending radially from the support frame 53 are fitted in long holes 54 a provided in the side wall 54 b of the main plate 54.

  As shown in FIG. 19B, the relationship between the support shaft 53a and the long hole 54a is fitted in the optical axis direction 57 of the correction lens 52 and no play occurs, but the long hole is formed in the direction orthogonal to the optical axis. 54a extends. Accordingly, the support frame 53 is restricted in movement in the direction of the optical axis 57 with respect to the base plate 54, but can freely move within a plane orthogonal to the optical axis 57 (arrows 58p, 58y, 58r). However, since the tension coil spring 59 is hung between the pin 53b on the support frame 53 and the pin 54c on the base plate 54, it is elastically restricted in the respective directions 58p, 58y, and 58r.

  As shown in FIG. 19A, coils 510p and 510y are attached to the ground plane 54 so as to face the permanent magnets 56p and 56y. The arrangement of the yoke 55, the permanent magnet 56p, and the coil 510p is as shown in FIG. 19C (the permanent magnet 56y and the coil 510y are also arranged in the same manner). When a current is passed through the coil 510p, the support frame 53 is driven in the direction of the arrow 58p, and when a current is passed through the coil 510y, the support frame 53 is driven in the direction of the arrow 58y. The driving amount is obtained by balancing the spring constant of the tension coil spring 59 in each direction with the thrust generated in relation to the coils 510p and 510y and the permanent magnets 56p and 56y. That is, the amount of eccentricity of the correction lens 52 can be controlled based on the amount of current flowing through the coils 510p and 510y.

  The image blur correction apparatus described with reference to FIGS. 16 to 19 generates a driving force so as to balance the spring force of the spring that supports the correction lens 52 as disclosed in Patent Document 1, thereby correcting the image blur. It is a system that performs. Since it is not necessary to always detect the position of the correction lens 52 in this system, a small and low-cost vibration isolation system can be provided.

  FIG. 14 is a cross section showing the yoke 55, the permanent magnet 56p, the coil 510p, and the tension coil spring 59 on the same ground plane 54 in the cross section of the image correction optical apparatus shown in FIG. Actually, since the coil 510p and the tension coil spring 59 are not aligned in a straight line, the section does not have such a cross section, but the figure is modified as shown in FIG. 14 for easy understanding.

  The correction lens 52 is elastically supported by being pulled in the radial direction by a pair of tension coil springs 59, and determines the position thereof. As described above, the correction lens 52 is driven to correct image blur by applying a current against the elastic force of the elastic support to the coil 510p. Here, if the correction lens 52 becomes heavy, the tension coil spring 59 will be greatly bent against the weight.

FIG. 15 shows this state. When the tension coil spring 59 is bent, the holding position of the correction lens 52 is shifted, and the photographing optical axis 41 and the optical axis 57 of the correction lens 52 do not match. The photographing light flux passing through the photographing optical axis 41 is deflected as indicated by 41a when the position of the correction lens 52 is shifted. If the amount of deflection is small, there is no problem. However, if the weight of the correction lens 52 is increased and the displacement due to its own weight increases, the imaging position on the imaging surface is greatly displaced, which becomes a problem. . In order to eliminate this deviation, 1) The attachment position of the tension coil spring 59 is adjusted in advance in consideration of the deviation of the correction lens 52 due to its own weight.

2) The spring constant of the tension coil spring 59 is extremely increased, and the amount of deflection of the tension spring 59 due to the weight of the correction lens 52 is reduced.
There are two methods.

  Here, in the case of 1), when the camera 43 of FIG. 16 is held in this posture, there is no shift in the imaging position on the imaging surface of the imaging device 44. However, when the camera 43 is held in the vertical position, the correction lens 52 is displaced with a change in the direction of gravity, and the imaging position on the imaging surface of the imaging device 44 is shifted.

  In the case of 2), the image forming position can be slightly shifted even in the case of vertical position shooting. However, since the spring constant of the tension coil spring 59 is extremely large, the energy for moving the correction lens 52 against the spring force during image blur correction becomes very large.

  Even when the weight of the correction lens 52 is small, if the driving stroke for correcting the image blur is necessary, the amount by which the tension coil spring 59 can be expanded and contracted during the image blur correction driving increases. Therefore, a large current must be applied to the coil 510p. In the case of a consumer camera, the battery is consumed immediately, which is not realistic.

  In this case, in order to reduce the drive current value, the spring constant of the tension coil spring 59 may be reduced. However, in this case, the displacement amount of the correction lens 52 due to its own weight increases, and the displacement of the imaging position on the imaging surface is increased. It gets bigger.

In order to solve such a problem, Patent Documents 2 and 3 disclose techniques for balancing a pair of reverse power lenses.
JP-A-8-184870 JP-A-2-162320 JP 11-167074 A

  However, in Patent Document 2, a link mechanism (beam) for balancing a lens with reverse power extends long in the optical axis direction, and the shake correction apparatus itself becomes large. In addition, since the correction lens is pivotally held via the beam, there is a possibility that a positional shift in the optical axis direction occurs due to image blur correction, resulting in deterioration of accuracy in the focus direction.

  In Patent Document 3, an individual image blur correction device is required for biaxial image blur correction, and it is difficult to reduce the size.

(Object of invention)
SUMMARY OF THE INVENTION An object of the present invention is to provide an image shake correction apparatus, an imaging apparatus, and an optical apparatus that reduce the image formation position shift on the image plane due to the weight of the first and second correction lenses and that are small and save power. It is.

  To achieve the above object, the present invention provides a first driven means including a first correction lens for image blur correction and a second driven lens including a second correction lens having a power opposite to that of the first correction lens. Means, support means for movably supporting the first driven means and the second driven means in a plane orthogonal to the optical axis, and a first coil and a second coil provided in the first driven means. It consists of a magnet, a second coil and a first magnet provided in the second driven means, and the first coil and the first magnet are opposed to each other, and the second coil and the second magnet are opposed to each other. An image blur correction apparatus having driving means for driving the first driven means and the second driven means in opposite directions within a plane orthogonal to the optical axis is provided.

  In order to achieve the above object, the present invention provides a first driven means including a first correction lens for image blur correction and a second target including a second correction lens having a power opposite to that of the first correction lens. A driving means; a supporting means for movably supporting the first driven means and the second driven means in a plane perpendicular to the optical axis; a first coil provided on the first driven means; It consists of two coils and a first magnet and a second magnet provided in the second driven means, the first coil and the first magnet are opposed to each other, and the second coil and the second magnet are opposed to each other. Thus, an image blur correction apparatus having driving means for driving the first driven means and the second driven means in opposite directions within a plane orthogonal to the optical axis is provided.

  In order to achieve the above object, the present invention provides a first driven means including a first correction lens for image blur correction and a second target including a second correction lens having a power opposite to that of the first correction lens. A driving means; a supporting means for movably supporting the first driven means and the second driven means in a plane perpendicular to the optical axis; a first coil provided in the first driven means; A second coil provided in the second driven means; a driving means comprising a first magnet and a second magnet provided in a fixed member; the first coil and the first magnet are opposed to each other; And a coupling means for mechanically coupling the first driven means and the second driven means so as to be driven in opposite directions within a plane orthogonal to the optical axis. An image shake correction apparatus is provided.

  Similarly, in order to achieve the above object, the present invention is an imaging apparatus including the image blur correction apparatus of the present invention.

  Similarly, in order to achieve the above object, the present invention is an optical device including the image blur correction device of the present invention.

  According to the present invention, it is possible to provide an image shake correction apparatus, an imaging apparatus, or an optical apparatus that reduces the image formation position shift on the image plane due to the weight of the first and second correction lenses, and is small and power-saving. .

  The best mode for carrying out the present invention is as shown in Examples 1 to 3 below.

  1 is a front view of an image blur correction apparatus provided in a digital camera or the like that is an image pickup apparatus according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line A1-A2 of FIG. 1, and FIG. It is A1-B sectional drawing.

  1 to 3, reference numerals 10a and 10b denote correction lenses having opposite powers for image blur correction. The correction lens 10a has a positive power and the correction lens 10b has a negative power. Reference numerals 11a and 11b denote holding frames for holding the correction lenses 10a and 10b. Reference numeral 12 denotes a base plate of the image blur correction apparatus.

  On the holding frame 11a, pins 14a to 14c for hooking the hook portions of the tension coil springs 15a to 15c are provided equally at 120 °. The holding frame 11b is provided with pins 14d to 14f (only the tension coil spring 14d is shown in FIG. 2) that hangs the hook portions of the tension coil springs 15d to 15f (only the tension coil spring 15d is shown in FIG. 2) equally at 120 °. . Also on the base plate 12, pins 13a to 13c for hooking the hook portions of the tension coil springs 15a to 15c are provided equally at 120 °. Similarly to this, pins 13d to 13f (only the pin 13d is shown in FIG. 2) are provided on the back surface of the base plate 12 of FIG.

  The tension coil springs 15 a to 15 f are provided between the pins 14 a to 14 f provided on the holding frames 11 a and 11 b and the pins 13 a to 13 f provided on the base plate 11. As shown in FIG. 2, the tension coil springs 15 a to 15 f also have a tensile force in the direction of the optical axis 100 (the left-right direction in FIG. 2). As shown in FIG. 2, balls 16a to 16c (only the ball 16a is shown in FIG. 2) are sandwiched between the holding frame 11a and the main plate 12, and the holding frame 11a and the main plate 12 are tension coil springs 15a to 15c. Is biased by the component of the tensile force of the optical axis direction.

  Here, the holding frames 11a and 11b are supported to be movable in the directions of arrows 111p and 111y as shown in FIG. 1 with respect to the base plate 12, but the movement is restricted in the direction of the optical axis 100. Further, since the tension coil springs 15a to 15f apply a necessary and sufficient force to the holding frames 11a and 11b in the radial direction as shown in FIG. 1, the rotational motion in the direction of the arrow 111r is restricted.

  When driving in the directions of the arrows 111p and 111y, the initial tensions of the tension coil springs 15a to 15f are offset because they are equally distributed in the radial direction. Therefore, the required driving force is determined not by the magnitude of the initial tension but only by the spring constants of the tension coil springs 15a to 15f. Therefore, driving in the directions of the arrows 111p and 111y can be realized with a relatively small force.

  The holding frame 11a is provided with an arm portion, and a coil 18a is fixed thereto. Further, as shown in FIG. 3, a yoke 110b and a permanent magnet 17b such as neodymium are fixed to the holding frame 11a so as to face the holding frame 11a. The holding frame 11b is also provided with an arm portion, to which the coil 18b is fixed. As shown in FIG. 2, a yoke 110a and a permanent magnet 17a such as neodymium are fixed to the holding frame 11b so as to face the coil 18a.

  The permanent magnets 17a and 17b are magnetized in the thickness direction as shown in FIG. 2 and FIG. 3, and the magnetic flux passes through the coils 18a and 18b existing on the opposing surface in a direction parallel to the optical axis 100 (FIG. 2 and FIG. 2). It penetrates in the left-right direction in FIG.

  Here, the holding frame 11a and the correction lens 10a constitute a first driven part, and the holding frame 11b and the correction lens 10b constitute a second driven part. Further, the balls 16a to 16f and the tension coil springs 15a to 15f constitute an elastic support portion. Further, the coil 18a and the permanent magnet 17b, which are part of the first driven part, and the coil 18b and the permanent magnet 17a, which are part of the second driven part, constitute a driving part.

  With this configuration, when the correction lens 10a and the correction lens 10b have substantially the same weight, the weights of the first driven portion and the second driven portion can be made substantially equivalent, and the first driven portion In addition, the amount of displacement due to the weight of the second driven part can be made substantially equal.

  The drive mechanism of the drive unit will be described.

  As described above, the driving unit includes the coil 18a and the permanent magnet 17b that are part of the first driven unit, and the coil 18b and the permanent magnet 17a that are part of the second driven unit, and the permanent magnet 17a. , 17b penetrates the coils 18a, 18b vertically. Therefore, when a current is passed through the coil 18a, the holding frame 11a is efficiently driven in the direction of the arrow 113a as shown in FIG. 1. Similarly, when a current is passed through the coil 18b, the holding frame 11a is moved in the direction of the arrow 113b. It is driven efficiently.

  The driving amount is generated electromagnetically between the spring force derived from the spring constant of the tension coil springs 15a, 15b, 15c, 15d, 15e, and 15f and between the coils 18a and 18b and the permanent magnets 17a and 17b. It is determined by the balance with thrust. That is, the amount of eccentricity of the correction lens 10a can be controlled by the amount of current flowing through the coils 18a and 18b.

  FIG. 4 is a block diagram showing a drive circuit system for controlling the drive of the correction lens 10a.

  The pitch target value 51p and the yaw target value 51y are drive target values for driving each driven part (correction lens) in the direction of the arrow 111p that is the pitch direction and the direction of the arrow 111y that is the yaw direction, respectively. This corresponds to the portion 418p. The target value in each direction is gain-adjusted by the pitch driving force adjustment unit 52p and the yaw driving force adjustment unit 52y according to the driving force in each driving direction.

  The output of the pitch driving force adjusting unit 52p is input to the coil 18a driving circuit 54a (corresponding to the PWM duty converter 419p and the driving unit 420p in FIG. 18) and used to apply a current to the coil 18a. Further, the output of the pitch driving force adjusting unit 52p is input to the coil 18b driving circuit 54b (corresponding to the PWM duty conversion unit 419p and the driving unit 420p in FIG. 18) via the adding circuit 53b and applies a current to the coil 18b. Used for. That is, the same amount of current is applied to the coils 18a and 18b in phase with the signal of the pitch drive target value 51p.

  When the same amount of current is applied to the coils 18a and 18b, as shown in FIG. 5, the coil 18a generates a driving force in the direction of the arrow 113a, and the coil 18b applies a driving force in the direction of the arrow 113b. appear. Therefore, the resultant force generates a driving force along the arrow 111p that is the pitch direction as indicated by the arrow 113p. In addition, since the driving force at this time is such that the two coils 18a and 18b are rotated 90 degrees, the driving force obtained by combining 1 / √ (2) of the driving forces of the coils 18a and 18b is obtained. appear.

  Next, when the same amount of current is applied to the coils 18a and 18b in opposite phases, as shown in FIG. 6, the coil 18a generates a driving force in the direction of the arrow 113a, and the coil 18b is in the direction of the arrow 113b. Driving force is generated in the opposite direction. Therefore, the resultant force generates a driving force along the arrow 111y that is the yaw direction as indicated by the arrow 113y. In addition, since the driving force at this time is such that the two coils 18a and 18b are rotated 90 degrees, the driving force obtained by combining 1 / √ (2) of the driving forces of the coils 18a and 18b is obtained. appear.

  The driving force adjusting units 52p and 52y are provided to correspond the eccentricity sensitivity of the optical system and the correction amount of the correction lens with respect to shake.

  As described above, when the coils 18a and 18b are energized, the first driven portion including the holding frame 11a and the correction lens 10a is driven from the relationship with the direction of the magnetic flux of the permanent magnets 17a and 17b. At the same time, the second driven part composed of the holding frame 11b and the correction lens 10b is subjected to a reaction, and the direction in which the first driven part tries to drive in a plane orthogonal to the optical axis 100. Driven in reverse. That is, when the first driven portion is driven in the direction of arrow 112a in FIG. 2, the second driven portion moves in the direction of arrow 112b. At this time, the spring constants of the tension coil springs of the first driven part and the tension coil springs of the second driven part must be uniform.

  The image blur correction apparatus according to the first embodiment includes, as components, a first driven unit including a correction lens 10a and a second driven unit including a correction lens 10b having a power opposite to that of the correction lens 10a. In addition, the first driven portion and the second driven portion are supported by the balls 16a to 16f and the tension coil bars 15a to 15f for supporting the first driven portion and the second driven portion so as to be movable in a plane orthogonal to the optical axis 100. Furthermore, it has a coil 18a provided in the first driven part, a permanent magnet 17b provided in the first driven part, a coil 18b provided in the second driven part, and a permanent magnet 17a provided in the second driven part. . And the drive part which drives a 1st to-be-driven part and a 2nd to-be-driven part to a mutually reverse direction in the plane substantially orthogonal to the optical axis 100 in relation to the coil 18a and the permanent magnet 17b and the coil 18b and the permanent magnet 17a. Have

  With the configuration as described above, the first driven unit and the second driven unit in which the weight difference is eliminated are moved in the opposite directions within a plane orthogonal to the optical axis 100 by the driving unit. In FIG. 3, when the correction lens 10a, which is a convex lens, is driven in the direction a, the optical axis is deflected upward in FIG. In addition, when the correction lens 10b, which is a concave lens having a power opposite to this, is driven in the direction b, the optical axis is also deflected upward in FIG. 3 due to decentering, so that the correction lenses 10a and 10b are in the reverse direction. A large deflection can be obtained by being driven. Therefore, a large image blur correction can be performed with a small driving amount.

  In addition, it is possible to sufficiently reduce the occurrence of a positional deviation caused by the weight of the correction lens 10 (10a, 10b) on the imaging surface. In other words, more ideal image blur correction can be performed. it can. In addition, it is possible to provide an image blur correction apparatus and an imaging apparatus that are small and can correct image blur with less power. This is because, with an appropriate optical design, when the correction lenses 10a and 10b are decentered in the same direction due to the influence of their own weight, etc., the correction lenses 10a and 10b cancel the deflection directions of the respective correction lenses. meet. For this reason, there is no problem of an image shift that may occur in an image shake correction apparatus including only one correction lens.

  FIG. 7 is a front view of an image shake correction apparatus according to Embodiment 2 of the present invention, and FIG. 8 is a cross-sectional view taken along line A3-A4 in FIG. Note that members having the same functions as those of the first embodiment are denoted by reference numerals in which the high-order digits of the reference numerals in FIG. For example, in the case of the correction lens 10a, the correction lens 20a, and in the directions of arrows 111p, 111y, and 111r, the directions of arrows 211p, 211y, and 211r.

  7 and 8, 20a and 20b are correction lenses having opposite powers for image blur correction, and 21a and 21b are holding frames for holding the correction lenses 20a and 20b. Reference numeral 22 denotes a base plate of the image blur correction apparatus. The second embodiment is suitable when the weight ratio between the correction lens 20a and the correction lens 20b is not equally distributed and the weight of the correction lens 20a is larger.

  In the second embodiment, the first driven portion is configured by the holding frame 21a and the correction lens 20a, and the first driven portion is configured by the correction lens 20b that is lighter than the holding frame 21b and the correction lens 20a. Further, a support portion is constituted by the balls 26a to 26f and the tension coil springs 25a to 25f.

  Further, in the second embodiment, as shown in FIG. 7, coils 28a and 28b are provided as a part of the first driven part, and the weight is higher than the coils 28a and 28b as a part of the second driven part. Larger permanent magnets 27a and 27b are provided. And the drive part is comprised by the coils 28a and 28b and the permanent magnets 27a and 27b.

  With such a configuration, the first driven part having the correction lens 20a that is heavier than the correction lens 20b and the second driven part having the permanent magnets 27a and 27b that are heavier than the coils 28a and 28b. The weight difference can be made small. Therefore, the amount of displacement due to the weight of the first driven part and the second driven part can be made substantially equal.

  The image shake correction apparatus according to the second embodiment includes, as components, a first driven unit including the correction lens 20a and a correction lens 20b that is lighter than the correction lens 20a and has a power that is opposite to that of the correction lens 20a. And a second driven part. Further, the first driven portion and the second driven portion are supported by balls 26 a to 26 f and tension coil springs 25 a to 25 f that hold the first driven portion and the second driven portion movably in a plane orthogonal to the optical axis 200. Furthermore, it has coils 28a and 28b provided in the first driven part and permanent magnets 27a and 27b provided in the second driven part. And the drive means which drives a 1st to-be-driven part and a 2nd to-be-driven part to a mutually reverse direction in the plane substantially orthogonal to the optical axis 200 in relation to the coil 28a, the permanent magnet 27a, and the coil 28b, and the permanent magnet 27b. Have

  With the above-described configuration, the first driven part and the second driven part with a slight weight difference are moved in the opposite directions within a plane orthogonal to the optical axis 200 by the driving part.

  Therefore, it is possible to sufficiently reduce the occurrence of a positional shift due to the weight of the correction lens 20 (20a, 20b) due to the weight of the correction lens 20 (20a, 20b). In other words, it is possible to provide an image blur correction apparatus and an imaging apparatus that can perform more ideal image blur correction and can perform image blur correction with a small size and less power.

  Since the mechanism of the drive unit and the configuration of the support unit are the same as those in the first embodiment, the description thereof is omitted.

  9 is a front view of an image blur correction apparatus according to Embodiment 3 of the present invention, FIG. 10 is a cross-sectional view taken along line A5-A6 in FIG. 9, FIG. 11 is a cross-sectional view taken along line A6-B2 in FIG. FIG. 10 is a cross-sectional view taken along line C-A6 in FIG. 9. FIGS. 13A and 13B are enlarged views of a portion D in FIG. Note that members having the same functions as those in the first embodiment are denoted by reference numerals in FIG. For example, in the case of the correction lens 10a, the correction lens 30a, and in the directions of arrows 111p, 111y, and 111r, the directions of arrows 311p, 311y, and 311r.

  9 to 13, reference numerals 30a and 30b denote correction lenses having mutually opposite powers for image blur correction, and reference numerals 31a and 31b denote holding frames for holding the correction lenses 30a and 30b. Reference numeral 32 denotes a base plate of the image blur correction apparatus.

  In the third embodiment, the holding frame 31a and the correction lens 30a constitute a first driven portion, and the holding frame 31b and the correction lens 30b constitute a second driven portion. Further, a support portion is constituted by the balls 36a to 36f and the tension coil springs 35a to 35f. Further, the drive unit is constituted by a coil 38a which is a part of the first driven part, a coil 38b which is a part of the second driven part, and permanent magnets 37a and 37b provided on the ground plate 32 opposite to them. It is configured.

  With this configuration, when the weights of the correction lens 30a and the correction lens 30b are substantially equal, the weights of the first driven portion and the second driven portion can be made substantially equivalent.

  Further, as shown in FIGS. 12 and 13, the holding frames 31a and 31b are connected to the base plate 32 by a connecting member 39a having a spherical sliding rotation center portion 39a-a. The connecting member 39a has spherical sliding portions 39a-b and 39a-c at both ends thereof, and slides in the direction of the optical axis 300 with respect to the through holes provided in the holding frames 31a and 31b, respectively. It is stored so that it is free. The connecting member 39b has the same configuration.

  Therefore, for example, it is assumed that the holding frame 31a is driven in the direction of the arrow 314a (see FIG. 13) in a plane perpendicular to the optical axis 300. Then, the sliding rotation center part 39a-a rotates in the arrow 312 direction by being pushed by the sliding part 39a-b, and pushes the holding frame 31b in the arrow 314b direction by the sliding part 39a-c. At this time, the sliding portions 39a-b and 39a-c are slidable with respect to the through holes provided in the holding frames 31a and 31b. Therefore, even if the rotational movement is performed around the sliding rotation center portion 39a-a, the movement component in the optical axis direction is not hindered by preventing the holding frames 31a and 31b from moving in a plane orthogonal to the optical axis 300. To absorb. The coupling members 39a and 39b hold the pair of correction lenses 30a and 30b having opposite powers so as to be movable in opposite directions within a plane orthogonal to the optical axis 400.

  As for the drive unit, as in the first embodiment, the coils 38a and 38b, which are a part of the first and second driven parts, and the permanent magnets 37a and 37b provided on the ground plane 32 are correlated with each other. The first driven part and the second driven part are moved in a plane orthogonal to the optical axis 400.

  The image shake correction apparatus according to the third embodiment includes, as components, a first driven unit including a correction lens 30a and a second driven unit including a correction lens 30b having a power opposite to that of the correction lens 30a. . Further, the first driven portion and the second driven portion are supported by balls 36 a to 36 f and tension coil springs 35 a to 35 f that hold the first driven portion and the second driven portion in a plane perpendicular to the optical axis 300. Further, a coil 38a that is provided in the first driven portion and is driven in the first direction, a coil 38b that is provided in the second driven portion and is driven in the second direction, and a permanent plate provided on the ground plate 32 that is a fixing member. Magnets 37a and 37b are provided. The first driven portion and the second driven portion are mechanically driven in opposite directions in a plane orthogonal to the optical axis 300 in relation to the coil 38a and the permanent magnet 37a and the coil 38b and the permanent magnet 37b. Connecting members 39a and 39b to be connected to each other.

  With the above-described configuration, the driving unit causes the first driven unit and the second driven unit to move in opposite directions within a plane orthogonal to the optical axis 300 via the connecting members 39a and 39b. To do.

  Therefore, it is possible to sufficiently reduce the occurrence of the image shift on the imaging surface due to the position shift due to the weight of the correction lens 30 (30a, 30b), and the image shake correction apparatus that can reduce the image blur with a small amount of power. And an imaging device can be provided. Further, since the magnets 37a and 37b are arranged on the main plate 32, the weight of the drive unit is reduced. Further, since the first driven part including the correction lens 30a and the second driven part including the correction lens 30b each have a coil that can be driven in one direction, the weight balance between the two driven parts is increased. It is also possible to take.

  According to each of the embodiments described above, image blur correction is performed by driving a pair of correction lenses having opposite powers in opposite directions within a plane orthogonal to the optical axis. In each embodiment, in order to more reliably realize a well-balanced driving of the correction power pair of reverse power lenses in directions opposite to each other in a plane orthogonal to the optical axis, in each embodiment, a pair of correction lens and holding frame The weights of the driven parts are substantially matched.

  This driving doubles the image correction amount compared to driving only one correction lens. Or it can be said that it has an equivalent blur correction amount with half the drive amount.

  In addition, although the pair of correction lenses are misaligned in the same direction due to the self-weight deflection of the tension coil spring, the effects of blurring correction cancel each other with the same amount of misalignment because of the pair of lenses having opposite power. It will meet. For this reason, the positional deviation of the pair of correction lenses due to the self-weight deflection has a configuration that has very little influence on the imaging positional deviation on the imaging surface. Further, as described above, since the weights of the pair of correction lenses or driven parts are substantially equal to each other, the positional deviation due to its own weight can be alleviated.

  The mechanism can also be reduced in size by driving the pair of correction lenses in a plane.

(Correspondence between the present invention and the embodiment)
In the first embodiment, the first driven unit including the holding frame 11a and the correction lens 10a corresponds to the first driven unit including the first correction lens for shake correction of the present invention. The second driven unit including the correction lens 10b having the opposite power to the holding frame 11a and the correction lens 10a includes the second driven unit including the second correction lens having the opposite power to the first correction lens of the present invention. It corresponds to. In addition, the support unit including the balls 16a to 16f and the tension coil bars 15a to 15f that support the first driven unit and the second driven unit so as to be movable in a plane orthogonal to the optical axis 100 is provided in the present invention. Corresponds to support means. In addition, the coil 18a, the permanent magnet 17b, the coil 18b, and the permanent magnet 17a are the first coil and the second magnet provided in the first driven means of the present invention, the second coil provided in the second driven means, and This corresponds to the first magnet. And these are the first coil and the first magnet facing each other, and the second coil and the second magnet are facing each other, so that the first driven means and the second driven means are mutually in a plane perpendicular to the optical axis. This corresponds to driving means for driving in the reverse direction.

  Also in the second to third embodiments, the same components constitute each means, and the details thereof are omitted.

  In each of the above embodiments, the description has been continued by taking the image shake correction apparatus applied to the digital camera as an example. However, since the apparatus of the present invention can be combined into a small and stable mechanism, the digital camera Not limited to. In addition, the present invention can be applied to portable terminals such as binoculars, digital video cameras, surveillance cameras, Web cameras, and mobile phones. Further, it can be used for aberration correction in a polarizing device and an optical axis rotating device included in an optical device such as a stepper.

1 is a plan view of an image shake correction apparatus according to Embodiment 1 of the present invention. It is A1-A2 sectional drawing of FIG. It is A1-B1 sectional drawing of FIG. 1 is a block diagram illustrating a drive circuit system of an image shake correction apparatus according to Embodiment 1 of the present invention. FIG. 3 is a pitch direction drive balance diagram of the image shake correction apparatus according to the first embodiment of the present invention. FIG. 3 is a yaw direction drive balance diagram of the image shake correction apparatus according to the first embodiment of the present invention. FIG. 6 is a plan view of an image shake correction apparatus according to Embodiment 2 of the present invention. It is A3-A4 sectional drawing of FIG. FIG. 6 is a plan view of an image shake correction apparatus according to Embodiment 3 of the present invention. It is A5-A6 sectional drawing of FIG. It is A6-B2 sectional drawing of FIG. FIG. 10 is a cross-sectional view taken along line C-A6 in FIG. 9. It is the D section enlarged view of FIG. It is sectional drawing which shows the conventional image blur correction apparatus. It is sectional drawing which shows the image blurring correction apparatus explaining the conventional problem. It is an external view which shows the conventional anti-vibration camera. It is a perspective view which shows the outline of the image blur correction apparatus of the conventional vibration-proof camera. It is a block diagram which shows the circuit structure of the image blurring correction system of the conventional prevention camera. It is a block diagram which shows the conventional image blur correction apparatus.

Explanation of symbols

10a, 10b Correction lens 11a, 11b Holding frame 12 Ground plate 15a-15f Tension coil spring 16a-16f Ball 17a, 17b Permanent magnet 18a, 18b Coil 20a, 20b Correction lens 21a, 21b Holding frame 22 Ground plate 25a-25f Tension coil spring 26a-26f Ball 27a, 27b Permanent magnet 28a, 28b Coil 30a, 30b Correction lens 31a, 31b Holding frame 32 Ground plate 35a-35f Tension coil spring 36a-36f Ball 37a, 37b Permanent magnet 38a, 38b Coil 39a, 39b Connecting member

Claims (5)

First driven means including a first correction lens for image blur correction;
A second driven means including a second correction lens having a power opposite to that of the first correction lens;
Supporting means for supporting the first driven means and the second driven means movably in a plane perpendicular to the optical axis;
It consists of a first coil and a second magnet provided in the first driven means, and a second coil and a first magnet provided in the second driven means, and the first coil and the first magnet are opposed to each other. And the second coil and the second magnet are opposed to each other so that the first driven means and the second driven means are driven in opposite directions within a plane perpendicular to the optical axis. Image blur correction device characterized. First driven means including a first correction lens for image blur correction;
A second driven means including a second correction lens having a power opposite to that of the first correction lens;
Supporting means for supporting the first driven means and the second driven means movably in a plane perpendicular to the optical axis;
A first coil and a second coil provided in the first driven means, and a first magnet and a second magnet provided in the second driven means, the first coil and the first magnet being opposed to each other. And a driving means for driving the first driven means and the second driven means in opposite directions in a plane orthogonal to the optical axis by facing the second coil and the second magnet. Image blur correction device characterized. First driven means including a first correction lens for image blur correction;
A second driven means including a second correction lens having a power opposite to that of the first correction lens;
Supporting means for supporting the first driven means and the second driven means movably in a plane perpendicular to the optical axis;
A driving means comprising a first coil provided in the first driven means, a second coil provided in the second driven means, a first magnet and a second magnet provided in a fixed member;
The first coil and the first magnet face each other, and the second coil and the second magnet face each other, so that the first driven means and the second driven means are mutually in a plane perpendicular to the optical axis. An image blur correction apparatus comprising: a coupling unit that mechanically couples to drive in the reverse direction.   An image pickup apparatus comprising the image shake correction apparatus according to claim 1.   An optical apparatus comprising the image blur correction apparatus according to claim 1.

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