JP2008164927A - Image blur correction imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent image by performing optimum image blur correction regardless of temperature change by holding a correction lens group by a flat spring. <P>SOLUTION: The image blur correction imaging apparatus includes: a pitching holder 50 moving an image blur correction lens group in a Y direction through a P plate for pitching 52 and holding it movably in the Y direction; a pitching flat spring 54 moving the pitching holder 50 in the Y direction in such a state that one end of the pitching holder 50 is fixed; a yawing holder 55 moving the image blur correction lens group in an X direction through a P plate for yawing 56 and holding it movably in the X direction; and a yawing flat spring 74 moving the yawing holder 55 in the X direction in such a state that the other end of the pitching flat spring 54 is fixed at the upper and the lower ends of the yawing holder 55 and one end of the yawing holder 55 is fixed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a camera shake correction device that performs camera shake correction in an imaging apparatus such as a video camera, a digital video camera, or a digital still camera.

  In recent years, imaging devices such as consumer video movies have been reduced in size, weight, and optical zoom magnification, and their usability has been greatly improved. For this reason, imaging devices such as video cameras have become ordinary video equipment for general users. The reduction in size and weight of an image pickup apparatus such as a video camera and the increase in the magnification of optical zoom may cause camera shake at the time of shooting for users who are not proficient in shooting, and a stable image may not be obtained. In view of this, there has been proposed an imaging apparatus capable of performing optimum image blur correction regardless of the posture of the video camera to be photographed.

A conventional image blur correction video camera is described in Japanese Patent Application Laid-Open No. 2002-207232. By moving the correction lens group in two directions perpendicular to the optical axis, the user may experience image blur due to camera shake during shooting. There has been proposed an imaging apparatus that can obtain a stable image even if it occurs.
The proposed imaging apparatus will be described with reference to FIGS.

  In FIG. 12, an imaging optical system 2 is attached to the camera 1, and the imaging optical system 2 includes three lens groups L1, L2, and L3, and an intermediate lens group L2 is a correction lens group. By moving in two directions X and Y directions perpendicular to each other in a plane perpendicular to the axis Z, the optical axis Z is decentered to correct the movement of the image. The light incident on the lens group L1 passes through the lens groups L2 and L3 and forms an image on the solid-state imaging device 3.

  The yawing drive control unit 4x and the pitching drive control unit 4y pass the correction lens group L2 perpendicular to the optical axis Z of the imaging optical system 2 via the image blur correction drive mechanism 5 having the yawing actuator 5x and the pitching actuator 5y. It is driven in two directions X and Y axes orthogonal to each other in the plane. Here, the X axis in the camera 1 is referred to as a yawing direction, and the Y axis is referred to as a pitching direction.

  The position detection means 6 is means for detecting the position of the lens group L2 by the light emitting element 6a and the light receiving element 6b shown in FIG. 13, and drives and controls the correction lens group L2 together with the yawing drive control unit 4x and the pitching drive control unit 4y. A feedback control loop is formed. The yawing drive control unit 4x and the pitching drive control unit 4y constitute correction drive control means 4.

  The solid-state imaging device 3 disposed at the end of the optical axis Z converts an image incident through the imaging optical system 2 into an electrical signal. The video signal output from the solid-state imaging device 3 is analog signal processing. After being input to the means 7 and subjected to analog signal processing such as gamma processing and further converted into a digital signal by the A / D conversion means 8, the digital signal processing means 9 performs digital removal such as noise removal and contour enhancement of the digital signal. Signal processing is performed.

  The angular velocity sensors 10x and 10y for detecting the operation of the camera 1 detect the movement of the camera 1 itself including the imaging optical system 2, and the movement of the camera 1 is determined based on the output when the camera 1 is stationary. Both positive and negative angular velocity signals are output depending on the direction, and a yawing angular velocity sensor 10x and a pitching angular velocity sensor 10y are provided to detect movements in two directions of the yawing direction and the pitching direction, respectively. As described above, the yawing angular velocity sensor 10x and the pitching angular velocity sensor 10y detect the movement of the camera 1 due to camera shake and other vibrations. In the motion detection means 10, the output signals output from the yawing angular velocity sensor 10x and the pitching angular velocity sensor 10y are removed from DC drift components in unnecessary band components included in the output signals by the high-pass filters (HPF) 11x and 11y. Furthermore, the resonance frequency component and noise component of the sensor in the unnecessary band components included in the output signal are removed by the low-pass filters (LPF) 12x and 12y, and the level of the output signal is adjusted by the amplifiers 13x and 13y. Thereafter, the signals are converted into digital signals by the A / D converters 14 x and 14 y, and the digital signals are input to the image blur correction means (microcomputer) 15.

  The image blur correction mechanism 16 that drives and controls the correction lens unit L2 will be described with reference to an exploded perspective view of FIG. The fixed frame 17 holds a yawing frame 19 slidable in the yawing direction via yawing shafts 18a and 18b. The yawing frame 19 includes two pitching shafts 20a and 20b that are slidable in the pitching direction. The frame 21 is held, and the correction lens group L2 is fixed to the pitching frame 21. The coils 22x and 22y are fixed to the pitching frame 21, respectively. On the other hand, the fixed frame 17 holds a magnet 23x and a yoke 24x corresponding to the coil 22x, and a yawing actuator (actuator comprising a coil, a magnet, and a yoke) that drives and corrects the correction lens group L2 in the yawing direction via the pitching frame 21. 5x is configured. Similarly, a magnet 23y and a yoke 24y corresponding to the coil 22y are held on the fixed frame 17, and a pitching actuator (actuator comprising a coil, a magnet, and a yoke) that drives and corrects the correction lens group L2 in the pitching direction via the pitching frame 21. ) 5y is configured.

  Further, the light emitting element 6a constituting the position detecting means 6 is fixed to the pitching frame 21, and the light receiving element 6b fixed to the fixed frame 17 receives the projection light of the light emitting element 6a, and the correction lens group L2 Two-dimensional position coordinates are detected.

In FIG. 12, a yawing current value detection unit 25x detects a current value flowing through the coil 22x when the yawing actuator 5x operates, and similarly, the pitching current value detection unit 25y operates when the pitching actuator 5y operates. The posture detection means 25 for detecting the posture of the camera 1 is configured.
The image blur correction unit 15 includes an attitude control unit 26 that determines the attitude of the camera 1 (an upright attitude or a vertical attitude) based on the detection values of the yawing current value detection unit 25x and the pitching current value detection unit 25y, Based on a blur correction characteristic storage unit 27 including a nonvolatile memory (EPROM or the like) that stores a control signal of an image blur correction characteristic necessary for driving control of the correction lens unit L2 necessary for correction, and an output signal of the motion detection unit 10 An operation determination unit 28 that determines the shooting operation of the camera 1 and obtains the operation direction and acceleration, an attitude control unit 26, and a gain adjustment unit 29 that adjusts the gain of the correction operation corresponding to the shake correction characteristic. .

  The motion determination unit 28 performs filtering, integration processing, phase compensation, gain adjustment, clip processing, and the like on the output signals of the angular velocity sensors 10x and 10y captured via the A / D conversion units 14x and 14y, and performs the camera 1 Determine the shooting operation. The gain adjustment unit 29 determines the driving direction of the shake correction operation from the posture of the camera 1 determined by the posture control unit 26, selects the output side of the control signal, and uses the signal output from the operation determination unit 28 to Based on the data in the correction characteristic storage unit 27, the driving amount of the correction lens unit L2 necessary for blur correction is obtained. Control signals from the gain adjustment unit 29 are output to the yawing drive control unit 4x and the pitching drive control unit 4y via the D / A conversion units 30x and 30y constituting the correction drive control unit 4, respectively, and the yawing drive control unit 4x The pitching drive controller 4y outputs the yawing actuator 5x and the pitching actuator 5y, and the correction lens group L2 is controlled and driven to correct the movement of the image.

When current is supplied to the coils 22x and 22y of the pitching frame 21 from an external circuit, the pitching frame 21 having the correction lens group L2 is formed by the magnetic circuit formed by the yawing actuator 5x and the pitching actuator 5y. Are moved in two directions X and Y which are orthogonal to each other in a plane perpendicular to each other. The position of the pitching frame 21 is detected with high accuracy because the light receiving element 6b detects the light of the light emitting element 6a of the position detecting means 6. That is, by correcting the image incident on the solid-state imaging device 3 via the imaging optical system 2 by moving the correction lens group L2 in the X and Y directions within a plane orthogonal to the optical axis Z by the image blur correction drive mechanism 5. Can do.
JP 2002-207232 A

  However, in the conventional configuration, the pitching frame 21 holding the correction lens group is supported by the two pitching shafts 20a and 20b, and the pitching frame 21 slides and moves on the pitching shafts 20a and 20b. Therefore, the bearing portion of the pitching frame 21 and the pitching shafts 20a and 20b are configured with a clearance of several microns, and the parallelism of the bearing portion for holding the pitching frame 21 needs to be highly accurate. Therefore, it took a lot of time and labor to adjust the dimensions with the mold. In addition, a lubricant such as grease is applied to the clearance portion in order to improve the slidability of the bearing portion. Since the viscosity of the lubricant increases as the temperature decreases, the sliding load increases and the performance of the actuator tends to deteriorate. On the other hand, since the viscosity decreases as the temperature increases, there is a problem that the sliding load becomes too low, causing oscillation and the like, and the performance of the actuator deteriorates. In addition, since the camera is used outdoors, fine dust in the air adheres to the lubricating oil and hardens, making it difficult to slide or, in the worst case, preventing sliding. Had. In addition, the clearance between the shaft made of metal and the bearing made of resin is affected by the difference in linear expansion coefficient due to temperature change, and since the linear expansion coefficient of resin, which is the material of the bearing, is larger than that of the shaft, the clearance is low. There are problems such as a decrease in slidability and poor slidability.

  In the present invention, the pitching holder holding the correction lens unit L2 is held by two leaf springs, and the other end of the leaf spring is fixed to the yawing holder, so that the pitching holder can be easily moved in the pitching direction without a lubricant. By moving the pitching holder and yawing holder with two leaf springs and fixing the other end to the fixed frame, the yawing holder can be easily moved in the yawing direction without any lubricant, and there is a temperature fluctuation. However, an object of the present invention is to provide an image blur correction imaging apparatus that facilitates the movement of the correction lens unit L2 and that does not hinder the movement of the correction lens unit L2 even when fine dust is present.

  In order to solve the above-described conventional problems, an image blur correction imaging apparatus according to the present invention is an image blur correction apparatus that performs image blur correction by moving an image blur correction lens group in the X direction and the Y direction. A pitching holder for moving the lens group in the Y direction via a pitching P plate and movably holding in the Y direction; a pitching leaf spring for fixing one end of the pitching holder and moving the pitching holder in the Y direction; A yawing holder that moves the image blur correction lens group in the X direction via the yaw P plate and holds it movably in the X direction, and fixes the other end of the pitching plate spring to the upper and lower ends of the yawing holder. A yawing leaf spring for fixing one end of the yawing holder and moving the yawing holder in the X direction, and a fixing for fixing the other end of the yawing leaf spring When, the pitching plate spring and pitching actuator for Y-direction movement is obtained by further comprising a, a yawing actuator for the yawing plate spring is X direction movement.

  According to the image blur correction imaging apparatus of the present invention, the pitching holder holding the correction lens group L2 is held by the pitching leaf spring, the other end of the pitching leaf spring is fixed to the yawing holder, and the yawing holder is yawinged. Since the other end of the yawing leaf spring is fixed to the fixed frame, the pitching holder and the yawing holder can be moved in a direction perpendicular to the optical axis by utilizing the spring property of the leaf spring. This eliminates the need for lubricants required for shafts and bearings, and the viscosity of the lubricants does not fluctuate with changes in temperature, allowing stable movement of the pitching holder and yawing holder against changes in temperature. Can be realized. Further, even if there is fine dust or the like outside, there is no lubricant, so dust does not adhere and lubricity does not fluctuate, and the movement of the pitching holder and yawing holder with excellent environmental resistance can be realized. Furthermore, since the mechanism holds the pitching holder and the yawing holder with the leaf spring, the image blur correction mechanism can be realized in a small space by devising the shape of the leaf spring.

  Embodiments of an image blur correction imaging apparatus according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view showing a state in which the main mechanism of the image blur correction imaging apparatus according to the first embodiment of the present invention is attached to a fixed frame 17 constituting a main body chassis portion. FIG. 2 is a perspective view of the pitching holder portion 50 that fixes the correction lens group (not shown) and drives the correction lens group to be corrected in the Y direction, and pitching plate springs 54 are provided at both ends of the pitching holder 50. One end is bonded and fixed, and the pitching P plate 52 is driven in the Y direction to elastically control the pitching plate spring 54 to drive the correction lens group in the Y direction. 3 is a perspective view of the pitching holder and yawing holder portion, FIG. 4 is a perspective view in which a part of a fixing frame of the main mechanism is partially removed, FIG. 5 is a sectional view of the main mechanism, and FIG. FIG. 7 is a plan view of the main mechanism, FIG. 8 is a front view of the pitching magnet (dashed line is the pitching P plate) and a side view, and FIG. 9 is an explanatory view of analysis conditions by the general-purpose finite element method software ANSYS. 10 is a 2-250 Hz frequency response analysis of the correction lens group in the yawing direction, FIG. 11 is a 2-120 Hz frequency response analysis of the correction lens group in the yawing direction, FIG. 12 is a configuration diagram of a conventional image blur correction imaging apparatus, and FIG. This is an image blur correction drive mechanism of a conventional image blur correction imaging apparatus.

2 to 6, the correction lens group L <b> 2 is attached to the pitching holder 50 and then fixed to the pitching holder 50 with a screw or the like through the lens fixing ring 51.
A pitching P plate 52 is fixed to the notch at the lower end of the pitching holder 50 by adhesion or the like, and a pitching coil 53 for generating a thrust by a magnetic force in the Y-axis direction is wound around the pitching P plate 52. In addition, a pitching leaf spring 54 for fixing the pitching holder 50 is attached to the pitching holder 50 by bonding or the like to the central convex portions at the upper and lower ends of the pitching holder 50. The other end of the pitching leaf spring 54 is fixed to the central notch at the upper end of the yawing holder 55 by bonding or the like. That is, the pitching holder 50 is held by the yawing holder 55 with the force of the spring by the pitching leaf spring 54. A yawing P plate 56 is fixed to the yawing holder 55 by adhesion or the like, and a yawing coil 57 for generating a thrust force from the magnetic force in the X-axis direction is wound around the yawing P plate 56.

  3 and 4, a yawing leaf spring 74 for fixing the yawing holder 55 is attached to the yawing holder 55 to the convex portions at the left and right ends of the yawing holder 55 by bonding or the like. The other end of the yawing leaf spring 74 is fixed to the left and right end cutouts of the fixed frame 17 by adhesion or the like. That is, the yawing holder 55 is held by the yawing plate spring 56 on the fixed frame 17 by the spring force.

  A configuration in which the pitching holder 50 is moved in the pitching direction (Y axis) will be described with reference to FIGS. A pitching P plate 52 is attached to the pitching holder 50 by bonding. A pitching coil 53 having a long X-axis direction is wound around the pitching P plate and fixed to the pitching P plate 52 by bonding or the like. The pitching coil 53 is wound long in the X-axis direction when a magnetic field (B) is applied to the coil and a current (i) is passed through a coil having a coil length (L) perpendicular to the magnetic field. The coil generates thrust in accordance with Fleming's left-hand rule, and the coil thrust (F) is F = BiL, so that the coil thrust in the Y-axis direction is increased to increase the length in the X-axis direction. .

  In the present embodiment, the thrust by the magnetic force in the Y-axis direction is set large by winding at least twice as long as the Y-axis direction. FIG. 7A is a front view of the pitching actuator 60, and FIG.

  On the other hand, a pitching magnet 58 and a pitching yoke 59 corresponding to the pitching coil 53 are held on the fixed frame 17 to constitute a pitching actuator 60 that drives and controls the correction lens group L2 in the pitching direction via the pitching holder 50. The upper half of the pitching magnet 58 is magnetized to the N pole 61, and the lower half is magnetized to the S pole 62. Of course, it goes without saying that the N pole 61 and the S pole 62 may be reversed.

  In FIG. 7, if the magnetic flux 66 is emitted from the N pole 61 of the pitching magnet 58 toward the pitching P plate 52, the magnetic flux 66 passes through the pitching P plate 52, the pitching yoke 59, and the pitching P plate 52. The S pole 62 and the pitching yoke 59 return to the original N pole 61 of the pitching magnet 58. If a pitching coil current 67 flows through the pitching coil 53 as indicated by an arrow, the pitching P plate 52 moves in the direction of the arrow 68, that is, in the positive direction of the Y axis, according to Fleming's left hand rule. The pitching holder 50 to which the pitching P plate 52 is fixed moves in the direction of the arrow 68. At this time, since the pitching leaf springs 54 are attached to the upper and lower positions of the pitching holder 50 by adhesion or the like, the pitching leaf springs 54 are bent in the negative direction of the Y axis by the weight of the correction lens group L2 and the pitching holder 50. Since the correction lens group L2 is displaced from the optical axis Z, the current is passed through the pitching coil 53 so that the coil thrust is always applied in the direction of the arrow 68. The imaging optical system 2 is kept in a normal state. From this state, the pitching actuator 60 is controlled in accordance with the signal output from the image blur correction means 15 to correct the camera 1 due to camera shake.

  The amount of deviation of the pitching holder 50 from the optical axis Z is detected by the Hall element 69 disposed on the pitching P plate 52. The Hall element 69 is placed at the center position of magnetization of the pitching magnet 58 (the boundary between the N pole 61 and the S pole 62). At this time, the correction lens group L2 is set on the optical axis Z. Therefore, in FIG. 9, since the magnetic flux density acting on the Hall element from the outside is the same for both the N pole and the S pole, the output of the Hall element is zero. When 52 moves (the correction lens group L2 also moves simultaneously), the Hall element 69 increases the magnetic flux density of the N pole 61, and generates a potential proportional to the height of the magnetic flux density of the N pole. By storing the Hall element potential at the time of maximum movement, the amount of deviation from the optical axis Z can be detected.

  Similarly, a configuration in which the yawing holder 55 is moved in the yawing direction (X axis) will be described with reference to FIGS. A yawing coil 57 having a long Y-axis direction is wound around a yawing P plate 56 attached to the yawing holder 55 and fixed to the yawing P plate 56 by bonding or the like. The yawing coil 57 is wound so as to be longer in the Y-axis direction. As in the case of the pitching coil 53, at least the coil in the Y-axis direction is wound about twice as long as the X-axis direction, and the thrust generated by the magnetic force in the X-axis direction of the yawing coil 57 is set large.

  FIG. 8A shows a front view of the yawing actuator 65, and FIG. 8B shows a BB cross section. The fixed frame 17 holds a yawing magnet 63 and a yawing yoke 64 corresponding to the yawing coil 57, and constitutes a yawing actuator 65 that drives and controls the correction lens group L2 in the yawing direction via the yawing holder 55. The upper half of the yawing magnet 63 is magnetized to the N pole 75, and the lower half is magnetized to the S pole 76. Of course, it goes without saying that the N pole 75 and the S pole 76 may be reversed.

  In FIG. 8, assuming that a magnetic flux 77 is generated from the N pole 75 of the yawing magnet 63 toward the yawing P plate 56, the magnetic flux 77 passes through the yawing P plate 56, and the yawing yoke 64 and the yawing P plate 56. , The S pole 76 and the yawing yoke 64 are returned to the N pole 75 of the original yawing magnet 63. If a yawing coil current 78 flows through the yawing coil 57 as indicated by the arrow, the yawing P plate 56 moves in the direction of the arrow 79, that is, in the positive direction of the X-axis, according to Fleming's left hand rule. The yawing holder 55 to which the yawing P plate 56 is fixed moves in the direction of the arrow 79. Since the yawing leaf springs 74 are attached to the convex portions at the left and right ends of the yawing holder 55 by adhesion or the like, the correction lens group L2 is held at the optical axis Z position of the imaging optical system 2. From this state, the yawing actuator 65 is controlled in accordance with the signal output from the image blur correction means 15 to correct the camera 1 due to camera shake. The relationship between the output of the Hall element 69 and the position of the correction lens unit L2 is the same as in the case of pitching except that the X-axis direction and the Y-axis direction are different.

  The results of modal analysis and frequency response analysis of the pitching leaf spring 54 and the yawing leaf spring 74 by the general-purpose finite element method analysis software ANSYS will be described with reference to FIGS. Since the power supply of the image pickup apparatus is a battery, driving the correction lens unit L2 requires less power and requires a wide range of image blur correction. Specifically, the amount of movement in the X and Y directions of the correction lens unit L2 necessary for image blur correction is 0.5 mm, and the target is that a force of 8 gf can be generated as the coil thrust at that time.

If the Young's modulus E, width b, length L, and thickness h of the leaf spring are set, the spring stiffness k of the leaf spring is k = Ebh ³ / 4L ³ (Equation (1)). Since it is phosphor bronze and SUS and the value of Young's modulus E cannot be changed greatly, it is effective to decrease the thickness h or increase the length L in order to reduce the spring stiffness k of the leaf spring. In order to bend a 0.5 mm leaf spring with a target force of 8 gf, it is necessary to reduce the spring stiffness k. Using phosphor bronze (E = 0.98e ¹⁰ kgf / m ² ) as a material and generating a spring deflection of about 0.5 mm at 8 gf, in the case of a yawing leaf spring 74 as a result of calculation by ANSYS, as an example, b = 0.6 mm, L = 7.7 mm, and h = 0.02 mm. Similarly, in the case of the pitching leaf spring 54, as an example, it has been found that b = 0.5 mm, L = 15 mm, and h = 0.02 mm. Therefore, in order to increase the length L, the leaf spring is formed in a hollow rectangular shape or a hollow elliptical shape. That is, the pitching leaf spring 54 is bonded at the upper end and the lower end of the pitching holder 50 and the yawing holder 55. For example, at the upper end, between the connecting portion of the pitching holder 50 and the yawing holder 55 The pitching leaf spring 54 is formed in a hollow rectangular shape to ensure the length L. Similarly, the yawing leaf spring 74 is bonded to the yawing holder 55 and the fixed frame 17, but the yawing leaf spring 54 between the bonding portions is formed in a hollow rectangular shape to ensure the length L. Of course, any other shape can be realized as long as the length L of each leaf spring can be secured.

Now, how the primary resonance frequency and the bending of the spring change when the plate thickness h is 0.02 mm, that is, 20 μm to 30 μm will be described. The spring stiffness of the leaf spring when the mass of the holder is m and h = 20 μm is k1, the primary resonance frequency is f1, the force applied to the holder is F, the deflection of the leaf spring is x1, and the stiffness of the spring when h = 30 μm is k2. The primary resonance frequency is f2, and the bending of the leaf spring is x2. Since the primary resonance frequency f = (1 / 2π) × (k1 / m) ^1/2 (equation (2)), the spring stiffness k2 when the plate thickness h is 30 μm is k2 = (30 / 20) ³ k1≈3.4k1, and the primary resonance frequency f2 = (1 / 2π) × (k2 / m) ^1/2 = (1 / 2π) × (3.4k1 / m) ¹ / 2≈1.84f1 ≈ 79 Hz. That is, since 43 Hz becomes 79 Hz, there is a large margin for vibration. On the other hand, the deflection with respect to the coil thrust is F = k 2 · x 2 = k 1 · x 1 according to Hook's law, and x 2 = (k 1 / k 2) X1 = 0.67x1, and the leaf spring is displaced from 0.5 mm to 0.33 mm with a force of F = 8 gf. In other words, if the leaf spring is made thicker with the other shapes unchanged, the primary resonance frequency will be higher and the vibration will be better, but the spring displacement will be reduced, and a large coil will be required to bend the same displacement as 0.5 mm. Thrust is required.

  As described above, when the thickness h is increased from 20 μm to 30 μm, the stiffness of the spring becomes 3.4 times k2 = 3.4 k2. Further, the amount of spring displacement is as small as x2 = 0.67 × 1 and 0.67 times.

  Since it was found that the correction lens unit L2 can be moved with a minute force, the correction springs L2 are not induced by unnecessary resonance from the outside using the leaf spring, and vibration analysis is performed by ANSYS. The vibration resistance performance was examined and will be described below. FIG. 10 is a diagram showing the analysis conditions. Complete restraint (fixed to prevent movement) 70 in a total of four places (two places because the drawing is a cross section because the drawing is a cross section) of the fixed frame 17 at two upper ends and two lower ends. Then, a load W having an amplitude of 1 gf is swept and applied to the tip end portion of the pitching P plate 52 in a frequency range of 2 Hz to 250 Hz, and the transition of the lens center portion 71, the lens upper end portion 72, and the lens lower end portion 73 is calculated.

  FIGS. 11 and 12 show the analysis results of the frequency-gain characteristics, and the transitions of the lens central portion 71, the lens upper end portion 72, and the lens lower end portion 73 are almost the same. The case of 0.1 mm displacement by 1 gf force is set to 0 dB, which is a reference for displacement. That is, it is 20 dB when displaced by 1 mm with a force of 1 gf. As a result of modal analysis, it was found that resonance frequencies were generated at 43 Hz, 82 Hz, 187 Hz,... (Analysis result omitted). As for the mode of resonance, 43 Hz is a primary resonance mode in the X direction of the yawing leaf spring 74, 82 Hz is a primary resonance mode in the Y direction of the pitching leaf spring 54, and 187 Hz is the yawing leaf spring 74 and the pitching leaf spring. It turned out to be the resonance of both of the 54 springs. Japanese Patent Laid-Open No. 3-186823 describes that it is necessary to faithfully reproduce a signal in a 1 to 12 Hz camera shake band when a camera shake is caused by a camera. It is considered that it is sufficient to analyze up to 120 Hz and grasp the state of resonance to compensate for the double, but the analysis calculated resonance up to 250 Hz for safety. Since the resonance frequency close to 12 Hz is 43 Hz of the yawing leaf spring 56, frequency response analysis in the yawing direction was performed.

  FIGS. 11 and 12 show the results of frequency response analysis of the mechanism in the yawing direction (X direction), and it can be seen that the primary resonance occurs at 43 Hz where the resonance was confirmed by the modal analysis. The frequency response analysis of the lens center 71, the lens upper end 72, and the lens lower end 73 has substantially the same gain, and the correction lens group L2 is displaced by the same value with respect to vibration, so that the lens does not tilt (tilt) in the Y direction. It can be seen that it moves up and down.

Also, in FIG. 12, the gain is within 1 dB at 2 to 12 Hz and is almost stable, and the yawing direction does not have unstable resonance with respect to camera shake generated by humans, and a stable spring can be held. I understand. As can be seen from this graph, even if the primary resonance frequency is changed from 43 Hz to 40 Hz, the gain fluctuation is 1 dB or less, and if the primary resonance frequency is 40 Hz or more, it is affected by the gain fluctuation of the primary resonance frequency at 2 to 12 Hz. I understand that there is no. It can be considered that the fluctuation of the primary resonance frequency due to the temperature change is such that the Young's modulus of the leaf spring changes due to the temperature fluctuation, and that there is almost no fluctuation of the primary resonance due to the temperature. As a result of the modal analysis, the resonance in the pitching direction is 82 Hz, and since it is a frequency farther from 1 to 12 Hz, it is clear that the stability is good, so the description is omitted.
As described above, the image blur imaging device according to the present invention can provide an image blur correction mechanism in a space-saving manner as well as having excellent characteristics of environmental resistance against temperature changes and outdoor fine dust.

  An image blur correction imaging apparatus according to the present invention has a pitching holder holding a correction lens group held by a pitching leaf spring, the other end of the pitching leaf spring is fixed to the yawing holder, and the yawing holder is fixed to the yawing leaf spring. Since the other end of the yawing leaf spring is fixed to the fixed frame, the pitching holder and yawing holder can be moved in a direction perpendicular to the optical axis by utilizing the spring property of the leaf spring. The viscosity of the lubricant does not fluctuate due to temperature changes, and the pitching holder and yawing holder can be moved stably against temperature changes, and the environment is resistant to minute dust outdoors. The pitching holder and yawing holder can be moved, and image blur compensation is achieved in a space-saving manner. It is possible to provide a mechanism.

1 is a perspective view of main mechanisms of an image blur correction imaging apparatus according to a first embodiment of the present invention. 1 is a perspective view of a pitching holder portion of an image blur correction imaging apparatus according to Embodiment 1 of the present invention. FIG. 1 is a perspective view of a coupling state of a pitching holder and a yawing holder portion of an image blur correction imaging apparatus according to Embodiment 1 of the present invention. FIG. 1 is a perspective view in which a part of a fixed frame of a main mechanism of an image blur correction imaging apparatus according to Embodiment 1 of the present invention is cut. Sectional drawing of the whole structure of the image blurring correction imaging device in Example 1 of this invention 1 is a front view of an overall configuration of an image blur correction imaging apparatus according to a first embodiment of the present invention. The front view and sectional drawing of the pitching actuator of the image blur correction imaging device in Example 1 of the present invention 1 is a front view and a sectional view of a yawing actuator of an image blur correction imaging apparatus according to Embodiment 1 of the present invention. FIG. The figure which shows the relationship between the Y-axis direction moving amount | distance of the correction | amendment lens group of the image blur correction imaging device in Example 1 of this invention, and a Hall element output. The figure for demonstrating the analysis conditions by the general purpose finite element method software ANSYS of the image blurring correction imaging device in Example 1 of this invention The figure which shows the frequency response analysis (2-250 Hz) result of the correction | amendment lens group of the yawing direction of the image blur correction imaging device in Example 1 of this invention. The figure which shows the frequency response analysis (2-120 Hz) result of the correction | amendment lens group of the yawing direction of the image blur correction imaging device in Example 1 of this invention. Configuration diagram of a conventional image blur correction imaging apparatus The figure which shows the image blur correction drive mechanism of the conventional image blur correction imaging device

Explanation of symbols

L1 lens group L2 correction lens group L3 lens group Z optical axis W load 1 camera 2 imaging optical system 3 solid-state imaging device 4 correction drive control means 4x yawing drive control unit 4y pitching drive control unit 5 image blur correction drive mechanism 5x actuator for yawing 5y Pitching actuator 6 Position detecting means 6a Light emitting element 6b Light receiving element 7 Analog signal processing means 8 A / D conversion means 9 Digital signal processing means 10 Operation detecting means 10x Yawing angular velocity sensor 10y Pitching angular velocity sensor 11x HPF
11y HPF
12x LPF
12y LPF
13x amplifier 13y amplifier 14x A / D converter 14y A / D converter 15 Image blur correction means (microcomputer)
16 image blur correction mechanism 17 fixed frame 18a yawing shaft 18b yawing shaft 19 yawing frame 20a pitching shaft 20b pitching shaft 21 pitching frame 22x coil 22y coil 23x magnet 23y magnet 24x yoke 24y yoke 25 attitude detection means 25x yawing value pitching 25y Current value detection unit 26 Attitude control unit 27 Shake correction characteristic storage unit 28 Operation determination unit 29 Gain adjustment unit 30x D / A conversion unit 30y D / A conversion unit 50 Pitching holder 51 Lens fixing ring 52 P plate for pitching 53 Pitching coil 54 Pitching leaf spring 55 Yawing holder 56 P plate for yawing 57 Yawing coil 58 Pitching magnet 59 Pitching yoke 60 Ching actuator 61 N pole 62 S pole 63 Yawing magnet 64 Yawing yoke 65 Yawing actuator 66 Magnetic flux 67 Pitching coil current 68 Arrow 69 Hall element 70 Complete restraint 71 Lens center portion 72 Lens upper end portion 73 Lens lower end portion 74 Yawing leaf spring 75 N pole 76 S pole 77 Magnetic flux 78 Yawing coil current 79 Arrow

Claims (7)

In an image blur correction apparatus that performs image blur correction by moving an image blur correction lens group in the X direction and the Y direction,
A pitching holder for moving the image blur correction lens group in the Y direction via a pitching P plate and holding the image blur correction lens group movably in the Y direction;
A pitching leaf spring for fixing one end of the pitching holder and moving the pitching holder in the Y direction;
A yawing holder that moves the image blur correction lens group in the X direction through a yawing P-plate and is movable in the X direction;
A yawing leaf spring for securing the other end of the pitching leaf spring to the upper and lower ends of the yawing holder and for securing the one end of the yawing holder to move the yawing holder in the X direction;
A fixing frame to which the other end of the yawing leaf spring is fixed;
A pitching actuator for moving the pitching leaf spring in the Y direction;
A yawing actuator for moving the yawing leaf spring in the X direction;
An image blur correction imaging apparatus comprising: 2. The image blur correction imaging apparatus according to claim 1, wherein the pitching plate spring includes a pitching coil wound about twice as long in the X-axis direction with respect to the Y-axis direction. The image blur correction imaging apparatus according to claim 1, wherein the pitching plate spring has a hollow rectangular shape or a hollow elliptical shape that is formed long in the X direction. The image blur correction imaging apparatus according to claim 1, wherein the yawing leaf spring includes a pitching coil wound about twice as long in the Y-axis direction with respect to the X-axis direction. The image blur correction imaging apparatus according to claim 1, wherein a primary resonance frequency in the X direction of the plate spring for yawing exceeds 40 Hz. The amount of displacement of the pitching holder corresponding to the amount of displacement in the Y direction of the correction lens group is detected by a Hall element disposed on the P plate for pitching, and the current is passed through the pitching coil in accordance with the amount of displacement and the correction is performed. The image blur correction imaging apparatus according to claim 1, wherein the position correction of the lens group in the Y direction is performed. The amount of deviation of the yawing holder corresponding to the amount of deviation in the X direction of the correction lens group is detected by a Hall element disposed on the yaw P plate, and current is passed through the yawing coil in accordance with the amount of deviation to correct the correction. The image blur correction imaging apparatus according to claim 1, wherein the position correction in the X direction of the lens group is performed.

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