JP2012237871A - Blur correction unit, lens barrel and optical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blur correction unit able to improve the position control accuracy of an optical system.SOLUTION: The blur correction unit comprises: a fixing member (3); a movable part (2) supporting an optical system (20) and configured to move the optical system to a target position relative to the fixing member within a plane perpendicular to an optical axis; and an elastic member (11) supporting the movable part such that it is movable relative to the fixing member. The ratio of the natural frequency of a translation motion along a translation axis within a plane perpendicular to the optical axis of the movable part to the natural frequency of a rotary motion around the gravity of the movable part has a value in which the residual between the target position of the optical system and the actual position of the optical system is equal to or below a permissible value.

Description

  The present invention relates to a shake correction unit, a lens barrel, and an optical apparatus.

  Conventionally, the vibration correction optical system, which is a part of the photographing optical system, is moved in a direction substantially perpendicular to the optical axis, thereby preventing image vibration caused by vibration applied to the imaging apparatus and blurring of the subject. An image stabilization unit that corrects the image is known. Among such blur correction units, there is one provided with a detent means for restricting the rotation of the moving frame that holds the blur correction optical system around the optical axis (see Patent Document 1).

JP 2003-57707 A

  In the shake correction unit as described above, the moving frame that holds the shake correction optical system is supported by the fixed member via the spring, so that the movable frame can be relatively moved with respect to the fixed member. . In this case, the disturbance of the rotation component is caused to the moving frame by the arrangement position of the mechanism (electromagnetic actuator) for moving the moving frame mounted on the moving frame, the deviation of the center of gravity of the shake correction optical system, etc. There is. This disturbance of the rotational component may affect the position control accuracy of the shake correction optical system.

  Accordingly, the present invention has been made in view of the above problems, and provides a blur correction unit capable of improving the position control accuracy of an optical system, a lens barrel and an optical apparatus capable of improving optical performance. The purpose is to do.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although it attaches | subjects and demonstrates the code | symbol corresponding to drawing which shows one Embodiment of this invention, it is not limited to this.

  The blur correction unit of the present invention supports the fixed member (3) and the optical system (20), and moves the optical system relative to the fixed member relative to the target position in a plane perpendicular to the optical axis (2 ) And an elastic member (11) that supports the movable part so as to be relatively movable with respect to the fixed member, and the natural frequency of translational motion along the translational axis in a plane perpendicular to the optical axis of the movable part. And the ratio of the natural frequency of the rotational motion around the center of gravity of the movable part takes a value that makes the residual between the target position of the optical system and the actual position of the optical system equal to or less than an allowable value. It is.

  In this case, a damping mechanism (61, 62) that attenuates vibration around the center of gravity of the movable part may be provided.

  Further, in the present invention, the arrangement position of the elastic member, the elastic force of the elastic member, so that the ratio between the natural frequency of the translational motion and the natural frequency of the rotational motion takes a value that makes the residual less than or equal to an allowable value. At least one of the shape of the part included in the movable part and the arrangement position of the part included in the movable part may be adjusted. Furthermore, a plurality of elastic members can be provided, and at least one elastic force among the plurality of elastic members can be made different from the elastic force of the other elastic members.

  Further, in the present invention, the damping mechanism includes the magnet (62) whose relative position is changed by the rotational movement around the center of gravity of the movable part and the coil (61) of the closed circuit, and a current generated in the coil by the change of the relative position. It is possible to provide a magnetic damper in which a damping force based on the above acts on the movable part.

  The lens barrel of the present invention is a lens barrel (150) provided with the blur correction unit of the present invention.

  The optical apparatus of the present invention is an optical apparatus (200) including the shake correction unit of the present invention.

  The blur correction unit according to the present invention has an effect that the position control accuracy of the optical system can be improved. In addition, the lens barrel and the optical apparatus according to the present invention have an effect that the optical performance can be improved.

It is sectional drawing which shows typically the structure of an imaging device provided with the blurring correction unit which concerns on one Embodiment. 2A is a front view of the blur correction unit when viewed from the optical axis direction, and FIG. 2B is a cross-sectional view taken along the line AA of FIG. ) Is a sectional view taken along line BB in FIG. It is a figure showing the model of the movable part used for simulation. A graph showing the result of simulating the relationship between the elapsed time after control and the residual when the natural frequency (f _xy ) of translational motion is fixed and the natural frequency (f _θ ) of rotational motion is changed. is there. When the damping ratio (ζ _xy ) in the translational direction is 0.01 and the damping ratio (ζ _θ ) in the rotational direction is 0.01, the ratio between the rotational natural frequency and the translational natural frequency and the residual It is the graph which showed the simulation result of the relationship. Shake correction when the damping ratio (ζ _xy and ζ _θ ) in the translational direction and the rotational direction is fixed and the natural frequency (f _xy ) of translational motion and the natural frequency (f _θ ) of rotational motion are changed It is a table | surface which shows the result of having simulated the residual of the target position and real position of a lens. Resonance magnification (Q _xy ) of translational motion, resonance magnification (Q _θ ) of rotational motion, ratio (Q _θ / Q _xy ) between resonance magnification of rotational motion and resonance magnification of translational motion, and average residual relationship FIG.

  Hereinafter, an embodiment will be described in detail with reference to FIGS. FIG. 1 schematically illustrates an imaging apparatus 200 including a shake correction unit 100 according to the present embodiment. The imaging device 200 of the present embodiment is, for example, a non-lens interchangeable digital still camera. FIG. 1 shows a state at the time of photographing (during use).

  The imaging device 200 includes a housing 135 and a lens barrel 150. The image sensor 30 is fixed to the housing 135. The image pickup device 30 includes a photoelectric conversion device such as a CCD or a CMOS, and acquires a subject image formed on the image pickup surface.

  The lens barrel 150 includes a first lens group L1, a second lens group L2, a shake correction lens 20, a third lens group L3, a first group cylinder 110, a fixed cylinder 130, and a cam as an imaging optical system. A cylinder 120.

  The first lens group L1 is supported by the first group cylinder 110. The first group cylinder 110 is a cylindrical body that is supported by the cam cylinder 120 and is extended to the most object side among the members constituting the lens barrel of the lens barrel 150 at the time of photographing. In the first group cylinder 110, a rectilinear guide (straight groove) 115 is formed along the optical axis direction. The second lens group L2 is supported by the second lens group holding frame 111. The second lens group holding frame 111 is supported by the cam cylinder 120.

  The blur correction lens 20 is a lens that is displaced (shifted) in a direction orthogonal to the optical axis I to reduce image blur on the imaging plane. Note that the blur correction lens 20 constitutes a part of the blur correction unit 100. A specific configuration and the like of the shake correction unit 100 will be described later.

  The third lens group L3 is provided on the exit side of the vibration reduction lens 20, and is supported by the third lens group holding frame 140 so as to be movable in the optical axis I direction.

  The fixed cylinder 130 is a cylinder formed integrally with the housing 135. The fixed cylinder 130 includes guide bars 141 and 142 that support the third lens group holding frame 140. The fixed cylinder 130 has a rectilinear guide (straight groove) 131 formed along the optical axis direction. The rectilinear guide 131 includes a part of the second lens group holding frame 111 and the blur correction unit 100. A part of the fixing member 3 included in is inserted.

  The cam cylinder 120 is a cylindrical member provided so as to surround the outer side of the fixed cylinder 130, and is rotated around the optical axis I by the drive device 121. Cam grooves are formed on the outer peripheral surface and inner peripheral surface of the cam cylinder 120. Part of the first group cylinder 110, part of the second lens group holding frame 111, and part of the fixing member 3 included in the shake correction unit 100 are engaged with these cam grooves.

  Although not shown in FIG. 1, various mechanisms necessary for imaging such as an aperture mechanism and a shutter mechanism are provided in the housing 135, and a display is provided outside the housing 135. Buttons and various buttons necessary for operating the imaging apparatus 200 are provided.

  In the present embodiment, the first group cylinder 110 is guided in the optical axis direction by a rectilinear guide 115 formed in the first group cylinder 110, and the second lens group holding frame 111 and the fixing member 3 are fixed to the fixed cylinder 130. It is guided by a straight guide 131 formed in the above. Therefore, when the cam cylinder 120 (cam groove) is rotated around the optical axis by the driving device 121, each of the first and second lens groups L1 and L2 and the blur correction lens 20 is rotated along the optical axis. It moves along the I direction.

  Next, the configuration of the shake correction unit 100 according to the present embodiment will be described. FIG. 2A is a diagram showing a state in which the blur correction unit 100 is viewed from the optical axis I direction. 2B is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line BB in FIG. 2A. Note that a plane parallel to the paper surface of FIG. 2A is an XY plane (a plane defined by the X axis and the Y axis).

  As shown in FIGS. 2A to 2C, the shake correction unit 100 includes a fixed member 3, a movable part 2 supported by the fixed member 3, and a shake correction lens 20 supported by the movable part 2. And comprising.

  As shown in FIGS. 2B and 2C, the fixing member 3 has a substantially cylindrical shape. Note that, as shown in FIG. 1, a part of the fixing member 3 is provided with a protruding portion that engages with the cam groove of the cam cylinder 120, but in FIGS. 2A to 2C, it is illustrated. Is omitted.

  A plate-like portion 3a is provided inside the fixing member 3, and an opening 3c for allowing light to pass through is formed at the center of the plate-like portion 3a. Further, as shown in FIG. 2B, a coil 51a is provided in a part of the plate-like portion 3a. As shown in FIG. 2A, the plate-like portion 3a is provided with a coil 51b in addition to the coil 51a.

  The movable portion 2 includes a shift member 4 that holds the shake correction lens 20 and permanent magnets 52 a and 52 b that are disposed on the shift member 4.

  As shown in FIGS. 2B and 2C, the shift member 4 has an opening 4a for allowing light to pass therethrough, and holds the blur correction lens 20 in the opening 4a. A biasing force in the direction of arrow t is always applied to the shift member 4 by the elastic force of a spring (tensile coil spring) 11 provided between the shift member 4 and the fixing member 3. Three rolling spheres (not shown) are arranged between the shift member 4 and the plate-like portion 3 a of the fixing member 3. Here, in the shake correction unit 100 according to the present embodiment, it is assumed that the springs 11 are arranged at three locations as shown in FIG. The positional relationship in the optical axis direction between the plate-like portion 3a of the fixing member 3 and the shift member 4 is maintained by these springs 11 and a rolling sphere (not shown), and the operation guide of the shift member 4 in the XY plane is provided. It can be realized.

  In addition, permanent magnets 52a and 52b are provided at positions of the shift member 4 facing the coils 51a and 51b described above (see FIGS. 2A and 2B). The coil 51a and the permanent magnet 52a shift the driving force in the plane perpendicular to the optical axis direction (XY plane) by the electromagnetic interaction between the current flowing through the coil 51a and the magnetic field generated by the permanent magnet 52a. A moving magnet type drive mechanism (voice coil motor) 50a applied to the motor 4 is configured. The coil 51b and the permanent magnet 52b apply a driving force to the shift member 4 in a plane perpendicular to the optical axis direction by electromagnetic interaction between the current flowing through the coil 51b and the magnetic field generated by the permanent magnet 52b. The moving magnet type drive mechanism (voice coil motor) 50b is configured. In the present embodiment, the shift member 4 is adjusted by adjusting the magnitude and direction of the driving force applied to the shift member 4 from the drive mechanism 50a and the magnitude and direction of the drive force applied to the shift member 4 from the drive mechanism 50b. Can be moved in any direction within the plane (XY plane) orthogonal to the optical axis.

  The blur correction unit 100 includes a hall element (not shown). The Hall element detects the magnetic field of the permanent magnet 52a (52b) and outputs an analog signal corresponding to the magnetic field to a control device (not shown). In the control device, the relative positional relationship between the Hall element and the permanent magnets 52a and 52b is detected based on the analog signal output from the Hall element, and the position of the shift member 4 is detected based on the relative positional relationship. The position of the shift member 4 detected by the Hall element is used for position control of the shake correction lens 20 by a control device (not shown).

  Further, the shake correction unit 100 is provided with a magnetic damper including a damping coil 61 and two damping magnets 62. The damping coil 61 is a closed circuit coil provided on the plate-like member 3 a of the fixing member 3. The damping magnet 62 is a permanent magnet, and is provided at a position equidistant from the blur correction lens 20 in the shift member 4. In this magnetic damper, the change in the magnetic field due to the movement of the damping magnet 62 when the movable part 2 moves in the X-axis direction does not affect the damping coil 61. Further, when moving in the Y-axis direction, the electromagnetic interaction generated in the coil is canceled out because the direction of the magnetic force is reversed, and no force is generated. On the other hand, when the movable portion 2 rotates around the center of gravity of the movable portion 2, a current flows through the damping coil 61 due to a change in the magnetic field due to the movement of the damping magnet 62. In this case, due to the electromagnetic interaction between the magnetic field generated by the damping magnet 62 and the current flowing through the damping coil 61, a force opposite to the rotational direction of the movable portion 2 acts on the movable portion 2. That is, only when the movable part 2 rotates, a force (attenuating force) that attenuates rotation acts on the movable part 2 from the magnetic damper. When the movable part 2 translates, the damping force does not work.

  Next, a design method for the shake correction unit 100 according to the present embodiment will be described. In the present embodiment, the natural frequency (described as the translational natural frequency) of the translational motion of the movable part 2 along the translation axis in the plane (XY plane) perpendicular to the optical axis I direction, and the center of gravity of the movable part 2 It is assumed that the shake correction unit 100 is designed by paying attention to the natural frequency (described as the rotational natural frequency) of the rotational motion around.

  3A and 3B are diagrams for simulating the influence of the translational natural frequency and the rotational natural frequency on the difference (residual) between the target position and the actual position of the shake correction lens 20. A model of the movable part 2 used is shown. More specifically, FIG. 3A shows a model in which the lens center position is at the neutral point and the center of gravity of the movable portion 2 is at the neutral point, and FIG. 3B shows the lens center. A model in which the position is shifted from the neutral point and the center of gravity of the movable part 2 is shifted from the neutral point is shown.

Among these, as shown in FIG. 3A, the distance from the neutral point of the lens center position to the neutral point of the center of gravity of the movable part 2 is Lg, and as shown in FIG. The amount of movement of the center of gravity in the X-axis direction and the Y-axis direction, and the rotation angle are x, y, and θ, respectively. In this case, the relative movement amount xle in the X-axis direction and the relative movement amount yl in the Y-axis direction of the lens center position are expressed by equations (1) and (2).
xle = x + Lg × sin θ (1)
yle = y + Lg × (1-cos θ) (2)

Further, the mass of the movable part 2 (including the blur correction lens 20, the damping magnet 62, the permanent magnets 52a and 52b, the shift member 4, etc.) is m, the moment of inertia around the center of gravity of the movable part 2 is J, and the spring 11 Let the spring coefficient in the translation direction be k _xy , and the spring coefficient in the rotation direction be k _θ . In this case, the translational natural frequency f _xy of the movable part 2 is expressed by Expression (3), and the rotational natural frequency f _θ of the movable part 2 is expressed by Expression (4).

4A to 4C are based on the above equations (1) to (4) and the like, the translational natural frequency (f _xy ) is fixed at 45 Hz, and the rotational natural frequency (f _θ ) is 15 Hz. 4 is a graph showing a result of simulating the relationship between the elapsed time after the position control of the shake correction lens 20 and the residual when changing to 45 Hz and 100 Hz. In this simulation, the gain crossover frequency is 130 Hz, and the phase margin at the gain crossover frequency is 35 degrees.

In the simulation results of FIGS. 4A to 4C, the large residual vibration residuals seen in FIGS. 4A and 4C are due to rotational natural vibration. Looking at the time until the residual converges and the value of the converged residual, the rotational natural frequency (f _θ ) and the translational natural frequency (f _xy ) as shown in FIG. 4B are equal. In some cases, the time until the residual converges and the value of the converged residual are minimized.

FIG. 5 shows the ratio between the rotational natural frequency and the translational natural frequency when the translational damping ratio (ζ _xy ) is 0.01 and the rotational damping ratio (ζ _θ ) is 0.01. It is the graph which showed the simulation result of the relationship with a residual. From the graph of FIG. 5, when the translational natural frequency is changed, the residual can be minimized when the ratio of the rotation natural frequency to the translational natural frequency (f _θ / f _xy ) is 1. all right.

FIG. 6 shows the image blur correction when the damping ratios (ζ _xy and ζ _θ ) in the translation direction and the rotation direction are fixed and the translation natural frequency (f _xy ) and the rotation natural frequency (f _θ ) are changed. It is a table | surface which shows the result of having simulated the residual of the target position of the lens 20, and an actual position.

6A to 6C, even if the combination of the damping ratio (ζ _xy ) in the translation direction and the damping ratio (ζ _θ ) in the rotation direction changes as shown by a thick frame, the rotation natural vibration It was found that when the ratio of the number to the translational natural frequency (f _θ / f _xy ) is 1 (when the number in parentheses in the table is 1), the residual is minimized.

That is, by summing up the results of the above simulations, in the shake correction unit 100, regardless of the values of f _θ and f _xy , when f _θ / f _xy is 1 (the rotational natural frequency (f _θ ) is translated) It was found that the residual difference between the target position and the actual position of the blur correction lens 20 is minimized in the case where it is equal to the natural frequency (f _xy ). Therefore, it is considered desirable to design the blur correction unit 100 so that the ratio of the natural frequency of rotation of the movable part 2 to the natural frequency of translation is 1.

However, in the actual blur correction unit 100, it may be difficult to set the ratio (f _θ / f _xy ) between the rotation natural frequency and the translation natural frequency to 1. Therefore, in the present embodiment, the blur correction unit is set so that the ratio (f _θ / f _xy ) between the rotational natural frequency and the translational natural frequency takes a value that is less than or equal to an allowable value (for example, 3 μm). 100 is designed. In this design, for example, the arrangement position of the spring 11, the elastic force (spring constant) of the spring 11, the shape of the shift member 4 included in the movable part 2, and the permanent part included in the movable part 2 are prepared in advance. By changing / adjusting at least one of the positions of the magnets 52a and 52b and the damping magnet 62, f _θ / f _xy takes a value such that the residual is less than an allowable value (for example, 3 μm). To do. In this way, in this embodiment, the residual between the target position and the actual position of the shake correction lens 20 can be suppressed to an allowable value or less, and thus the accuracy of position control of the shake correction lens 20 is improved. It becomes possible. In addition, when adjusting the elastic force (spring constant) of the spring 11, it is not limited to uniformly changing / adjusting the spring constant of the three springs 11, and at least one spring constant of the three springs 11 is set to another spring. 11 may be changed or adjusted so as to be different from the spring constant of 11.

  Here, in the above design method, when the residual cannot be reduced to a tolerance or less due to a change in the arrangement of the components of the movable portion 2, the magnetic damper may be adjusted. The following points should be considered when adjusting the magnetic damper.

FIG. 7A shows, from the simulation results shown in FIGS. 6A to 6C, the resonance magnification (Q _xy ) of translational motion, the resonance magnification (Q _θ ) of rotation motion, and the rotation motion of the movable part 2. 6 is a table in which the ratio (Q _θ / Q _xy ) between the resonance magnification and the resonance magnification of translational motion and the average residual are arranged. FIG. 7B plots the results of FIG. 7A with the horizontal axis _representing the ratio (Q _θ / Q _xy ) of the translational and resonant motion magnifications, and the vertical axis representing the residual. It is a graph. Incidentally, the relationship between the translational damping ratio (ζ _xy ) and the rotational damping ratio (ζ _θ ), the translational resonance magnification (Q _xy ), and the rotational motion resonance magnification (Q _θ ) described above is , Represented by formula (5) and formula (6).
Q _xy = 1 / (2ζ _xy ) (5)
_{Q θ = 1 / (2ζ θ} ) ... (6)

FIG. 7B shows that the ratio (Q _θ / Q _xy ) between the resonance magnification of the rotational motion and the resonance magnification of the translation motion is smaller than 1, that is, the resonance magnification of the rotation motion is larger than the resonance magnification of the translation motion. It can be seen that when the difference is small (Q _xy > Q _θ ), the residual is less than or equal to an allowable value (eg, 3 μm). Therefore, in the above design, when adjusting the magnetic damper, the magnetic damper suppresses the rotational motion around the center of gravity of the movable part 2, and realizes Q _xy > Q _θ by reducing the resonance magnification of the rotational motion. We will make adjustments as possible. Specifically, Q _xy > Q _θ can be realized by adjusting the number of wirings of the damping coil 61 and the magnetic force of the damping magnet 62.

  As a result, even if the residual between the target position and the actual position of the shake correction lens 20 cannot be less than the allowable value due to a change in the arrangement of the components of the movable unit 2, the residual is less than the allowable value by the magnetic damper. Therefore, the position control accuracy of the movable part 2 can be improved.

  As described above in detail, according to the shake correction unit 100 of the present embodiment, the fixing member 3 and the shake correction lens 20 are supported, and the shake correction lens 20 is fixed in the plane perpendicular to the optical axis. In the plane perpendicular to the optical axis of the movable portion 2, and a movable portion 2 that moves relative to the target position, and a spring 11 that supports the movable portion 2 relative to the fixed member 3. The ratio of the natural frequency of the translational motion along the translational axis and the natural frequency of the rotational motion around the center of gravity of the movable part 2 is the ratio between the target position of the blur correction lens 20 and the actual position of the blur correction lens 20. The movable part 2 is designed so that the residual becomes a value that is less than or equal to the allowable value. Here, as shown in FIGS. 6A to 6C, the natural frequency of translational motion along the translational axis in the plane perpendicular to the optical axis of the movable unit 2 and the center of gravity of the movable unit 2. The residual between the target position and the actual position of the shake correction lens 20 changes depending on the ratio value with the natural frequency of the rotational motion around. Therefore, the ratio between the natural frequency of the translational motion along the translation axis in the plane perpendicular to the optical axis of the movable portion 2 and the natural frequency of the rotational motion around the center of gravity of the movable portion 2 is set to the above value. Thus, the residual can be suppressed within the allowable range, and thereby the position control accuracy of the blur correction lens 20 can be improved.

  Here, the ratio of the natural frequency of the translational motion along the translational axis in the plane perpendicular to the optical axis of the movable unit 2 and the natural frequency of the rotational motion around the center of gravity of the movable unit 2 is the above value. That is, the arrangement position of the spring 11, the elastic force of the spring 11, the shape of the component (for example, the shift member 4) included in the movable portion 2, and the component (for example, the permanent magnets 52a and 52b, damping) included in the movable portion 2. This can be realized by adjusting at least one of the arrangement positions of the magnets 62). Therefore, the position control accuracy of the shake correction lens 20 can be easily improved by changing the arrangement of the component parts and the like without devising the position control method.

  Further, in the shake correction unit 100 of the present embodiment, the resonance magnification of the rotational motion can be reduced by the magnetic damper that attenuates the vibration around the center of gravity of the movable part 2. Thereby, if the resonance magnification of the rotational motion of the movable part 2 is made smaller than the resonance magnification of the translational movement of the movable part 2, the residual between the target position and the actual position of the shake correction lens 20 can be reduced. Become. Thereby, the accuracy of position control of the shake correction lens 20 can be improved.

  Further, according to the lens barrel 150 and the imaging apparatus 200 of the present embodiment, since the shake correction unit 100 having high position control accuracy as described above is provided, the shake correction accuracy is improved and a stable image is obtained. be able to.

  In the above-described embodiment, the case where the imaging device 200 is a non-lens interchangeable digital still camera has been described. However, the present invention is not limited to this, and the imaging apparatus 200 may be a single-lens reflex digital camera. In this case, the lens barrel 150 may be an interchangeable lens of a single-lens reflex digital camera.

  In the above embodiment, the damping coil 61 is arranged on the fixing member 3 and the damping magnet 62 is arranged on the shift member 4. However, the damping coil 61 is arranged on the shift member 4 and the damping magnet 62 is fixed. It may be arranged on the member 3. Moreover, although the said embodiment demonstrated the case where the mechanism which drives the movable part 2 in XY plane was a moving magnet type voice coil motor, it is not restricted to this, Even if it is a moving coil type voice coil motor, Good. In addition to the voice coil motor, other drive mechanisms may be used.

  The above-described embodiment is an example of a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

2 Moving parts
3 Fixing member
4 Shift members
11 Spring
20 Shake correction lenses 50a and 50b Drive mechanisms 51a and 51b Coils 52a and 52b Permanent magnets
61 Damping coil
62 Damping Magnet 100 Shake Correction Unit 150 Lens Barrel 200 Imaging Device

Claims (7)

A fixing member;
A movable part that supports the optical system and moves the optical system relative to the fixed member in a plane perpendicular to the optical axis to a target position;
An elastic member that supports the movable part relative to the fixed member so as to be relatively movable;
With
The ratio of the natural frequency of the translational motion along the translational axis in the plane perpendicular to the optical axis of the movable part and the natural frequency of the rotational motion around the center of gravity of the movable part is the ratio of the natural frequency of the optical system. A shake correction unit characterized in that a residual value between a target position and an actual position of the optical system is set to a value equal to or less than an allowable value.   The blur correction unit according to claim 1, further comprising an attenuation mechanism that attenuates vibration around the center of gravity of the movable part.   The arrangement position of the elastic member, the elastic force of the elastic member, the ratio of the natural frequency of the translational motion and the natural frequency of the rotational motion takes a value that makes the residual less than an allowable value, The blur correction unit according to claim 1, wherein at least one of a shape of a part included in the movable part and an arrangement position of the part included in the movable part is adjusted. A plurality of the elastic members;
The blur correction unit according to claim 3, wherein at least one elastic force among the plurality of elastic members is different from the elastic force of the other elastic members.   The damping mechanism includes a magnet whose relative position is changed by a rotational movement around the center of gravity of the movable part and a closed circuit coil, and a damping force based on a current generated in the coil due to the change of the relative position. The blur correction unit according to claim 2, wherein the shake correction unit is a magnetic damper that acts on the magnetic field.   A lens barrel comprising the blur correction unit according to claim 1.   An optical apparatus comprising the blur correction unit according to claim 1.

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