JP2020194049A - Imaging device - Google Patents

Abstract

To provide an imaging device that can detect a position of a movable part while reducing an effect of output variation of position detection means with a simple configuration.SOLUTION: An imaging device comprises an imaging element, a movable part holding either the imaging element or an imaging optical system, a fixed part opposed to the movable part, a third magnet magnetized in a direction parallel to an optical axis of the imaging optical system, and position detection means for detecting a position of the movable part with respect to the fixed part. The position detection means detects a position of the movable part with respect to the fixed part in a first direction based on an output of two magnetic detection sensors arranged in line in the first direction orthogonal to the optical axis of the imaging optical system at a position opposed to the third magnet, and detects a position of the movable part with respect to the fixed part in a second direction based on an output of two magnetic detection sensors arranged in line in the second direction orthogonal to the first direction and the optical axis of the imaging optical system at a position opposed to the third magnet.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image pickup apparatus, and more particularly to position detection of an image shake correction mechanism.

In an image pickup device such as a digital camera, many techniques for correcting the influence of vibration applied to the device by moving an image pickup element such as a CMOS sensor or a part of an optical element of a photographing optical system in a direction orthogonal to the optical axis are disclosed. There is. In Patent Document 1, a voice coil motor composed of a permanent magnet and a coil is used to move the image pickup element so that it can move in a plane orthogonal to the optical axis of the photographing lens. By using the image shake correction means as in Patent Document 1, even if unnecessary shake is added to the image pickup apparatus, it is possible to acquire a photograph or a moving image without the influence of the shake by performing drive control to cancel the unnecessary shake. ..

JP-A-2017-15900

The image pickup apparatus described in Patent Document 1 detects the position of a movable portion by a position detecting means, and feeds back the detection result to perform drive control. At this time, a hall sensor is used as the position detection means, but when the hall sensor is arranged as in Patent Document 1, it is necessary to arrange a plurality of magnets dedicated to position detection. In this configuration, since a plurality of magnets dedicated to position detection are provided, the miniaturization and weight reduction of the image pickup apparatus are adversely affected.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an imaging device capable of detecting the position of a movable portion by reducing the influence of output fluctuation of the position detecting means with a simple configuration.

In order to achieve the above object, the imaging apparatus according to the present invention includes an imaging element, a movable portion that holds one of the imaging element and the imaging optical system, a fixed portion that faces the movable portion, the movable portion, and the above. It is provided on one of the fixed portions, and is provided on one of the movable portion and the fixed portion, and one first coil that generates a driving force in a first direction orthogonal to the optical axis of the photographing optical system by energization. A second coil that generates a driving force in the optical axis of the photographing optical system and a second direction orthogonal to the first direction, and the first movable portion and the other of the fixed portion. A first magnet arranged at a position facing the coil, a second magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil, and the movable portion. A third magnet provided on the other side of the fixed portion and magnetized in a direction parallel to the optical axis of the photographing optical system, and a position detecting means for detecting the position of the movable portion with respect to the fixed portion. The position detecting means is provided on one of the movable portion and the fixed portion, and is arranged at a position facing the third magnet so as to be arranged in the first direction. Based on the output, the position of the movable portion with respect to the fixed portion in the first direction is detected, and the second position is provided on one of the movable portion and the fixed portion and faces the third magnet. It is characterized in that the position of the movable portion in the second direction with respect to the fixed portion is detected based on the outputs of two magnetic detection sensors arranged so as to be arranged in a direction.

According to the present invention, it is possible to provide an imaging device capable of detecting the position of a movable portion by reducing the influence of output fluctuations of the position detecting means with a simple configuration.

It is a figure explaining the image pickup apparatus 1000 which concerns on embodiment of this invention. It is a figure explaining the image shake correction means 14 which concerns on 1st Embodiment of this invention. It is a figure which shows the positional relationship between the position detection element 2071-2074 and the position detection magnet 111. It is a figure which shows the state of the magnetic flux density of the magnetic circuit which comprises the position detection element 207 and the position detection magnet 111. It is a figure explaining the position detection method using the position detection elements 2073, 2074. It is a figure which shows the state of the magnetic flux density of the position detection element 207 which was rotated by θ about the center of the position detection magnet 111. It is a figure which shows the positional relationship of the 1st lower magnet part 107a, 107b and the coil 2051. It is a figure explaining the image shake correction means 24 which concerns on the 2nd Embodiment of this invention. It is a figure which shows the positional relationship between the position detection elements 2071, 2073 and the position detection magnet 111. It is a figure which shows the state of the magnetic flux density of the magnetic circuit which comprises the position detection element 2071, 2073 and the position detection magnet 111. It is a figure which shows the relationship between the magnetic flux density detected by the position detection element 2071 and the magnetic flux density detected by a position detection element 202c. It is a figure which shows the positional relationship between the position detection elements 2071, 2073 and the position detection elements 202b, 202c. It is a figure explaining the image shake correction means 34 which concerns on 3rd Embodiment of this invention. It is a figure which shows the positional relationship of the lower magnets 107a, 107b, the position detection element 202'a, and the coil 2051. It is a figure which shows the relationship between the position of the movable frame 206, and the magnetic flux density detected by the position detection element 202'a.

(First Embodiment)
The image pickup apparatus 1000 according to the first embodiment of the present invention will be described with reference to FIG.

FIG. 1A is a central sectional view of the image pickup apparatus 1000, and FIG. 1B is a block diagram showing an electrical configuration of the image pickup apparatus 1000. Those having the same reference numerals in FIGS. 1 (a) and 1 (b) correspond to each other.

The image pickup apparatus 1000 includes a camera 1 and a lens 2 that can be attached to and detached from the camera 1. The camera 1 includes a camera system control unit 5 such as a CPU that controls the entire camera 1, an image sensor 6 such as a CMOS or CCD that outputs an image signal corresponding to a light beam transmitted through a lens 2 that is an image pickup optical system. It includes an electrical contact 11 used for communication with the lens 2. Further, the camera 1 includes an image shake correction means 14 that optically corrects the image shake of the subject image imaged on the image sensor 6, a motion detection means 15 that detects the movement of the image pickup device 1000 with a gyro sensor, and the image sensor. A shutter mechanism 16 for controlling the exposure time of 6 is provided.

The lens 2 drives each part of an optical system 3 having a focus lens used for focus adjustment, an aperture mechanism, a correction lens used for image shake correction, a lens system control unit 12 such as a CPU that controls the entire lens 2, and an optical system 3. The lens driving means 13 is provided.

In the camera 1, the image sensor 6 photoelectrically converts the luminous flux from the subject according to the detection result of the operation detection unit 10 that detects the user operation on the release button or the like, and the image processing unit 7 converts the output image signal. The shooting operation is performed by performing image processing and storing it in the memory means 8. Further, the live view image display before shooting is performed by the display means 9 using the liquid crystal panel or the organic EL element via the camera system control unit 5. The camera 1 is a so-called mirrorless camera, and the display means 9 has a rear liquid crystal 9a provided on the back surface of the camera 1 and an electronic viewfinder 9b provided in the finder. The shutter mechanism 16 is driven and controlled by the shutter driving means 17 based on an exposure time set by the user or determined by the camera system control unit 5.

The image shake correction means 14 reduces (corrects) image shake caused by the movement of the camera 1 (camera shake) due to the user's camera shake or the like by moving the image sensor 6 in a direction orthogonal to the photographing optical axis 4 of the lens 2. ).

The camera system control unit 5 controls the amount of movement of the image sensor 6 for image shake correction with respect to the photographing optical axis 4. For example, based on the movement of the image pickup device 1000 detected by the motion detection means 15, a target position for reducing image shake of the subject image is calculated, and the image sensor 6 is moved to the calculated target position. It controls energization of the coils constituting the image shake correction means 14 described later.

The motion detecting means 15 detects the movement of the camera 1 around the photographing optical axis 4 and the movement of the camera 1 in the first direction and the second direction orthogonal to the photographing optical axis 4 and orthogonal to each other. ..

The image shake correction means 14 is a mechanism for translating the image sensor 6 into a plane orthogonal to the photographing optical axis 4 and rotating the image sensor 6 around the photographing optical axis 4 in order to reduce the image shake of the subject image.

The camera system control unit 5 performs image shake correction function detection processing such as detecting whether or not the image pickup device 1000 is fixed to a tripod or the like, and detecting a user's camera shake correction function stop instruction. When the camera shake correction function is stopped (IS_OFF state) in the image shake correction function detection process, the correction lens and the image sensor 6 included in the optical system 3 of the lens 2 are positioned and controlled at predetermined positions. On the other hand, when the activation of the camera shake correction function (IS_ON state) is detected in the image shake correction function detection process, the correction lens and the image sensor 6 included in the optical system 3 are the lens system control unit 12 and the camera system control unit 5. The drive is controlled according to the instruction of.

Next, the configuration of the image shake correction means 14 will be described with reference to FIG.

FIG. 2A is an exploded perspective view of the image shake correction means 14, and FIG. 2B is a partially enlarged view of part A shown in FIG. 2A. In FIG. 2A, members (= fixed parts) that do not move with respect to the camera 1 during image shake correction are numbered in the 100s, and members that move (= movable parts) are numbered in the 200s. Is attached. Further, the balls, which are members arranged between the fixed portion and the movable portion, are numbered in the 300s.

The image shake correction means 14 includes an upper yoke 101, screws 102a to 102c, a first upper magnet portion 1031 including magnets 103a and 103b, a second upper magnet portion 1032 composed of magnets 103c and 103d, and a third magnet 103e and 103f. It has an upper magnet portion 1033. In the following, the first upper magnet portion 1031, the second upper magnet portion 1032, and the third upper magnet portion 1033 are combined to form the upper magnet 103.

Further, a third lower magnet portion 1073 composed of the first lower magnet portions 1071, 107c, 107d composed of the auxiliary spacers 104a, 104b and the main spacers 105a to 105c, 107a, 107b, and the second lower magnet portions 1072, 107e, 107f. Have. In the following, the first lower magnet portion 1071, the second lower magnet portion 1072, and the third lower magnet portion 1073 are combined to form the lower magnet 107.

Further, it has a lower yoke 108, screws 109a to 109c, a base plate 110, and a position detection magnet 111. The above is a member that does not move with respect to the camera 1 at the time of image shake correction.

The upper yoke 101, the upper magnet 103, the lower magnet 107, and the lower yoke 108 form a magnetic circuit, forming a so-called closed magnetic path. The magnetic circuit formed is a first magnetic circuit composed of a first upper magnet portion 1031 and a first lower magnet portion 1071, a second magnetic circuit composed of a second upper magnet portion 1032 and a second lower magnet portion 1072, and a third upper portion. There are three third magnetic circuits including a magnet portion 1033 and a third lower magnet portion 1073.

The upper magnets 103a to 103f are adhesively fixed to the upper yoke 101 in a state of being attracted to them. The lower magnets 107a to 107f are adhesively fixed to the lower yoke 108 in a state of being attracted to the lower yoke 108. The upper magnets 103a to 103f and the lower magnets 107a to 107f are magnetized in the direction parallel to the optical axis (the direction of the alternate long and short dash line in FIG. 2A). In the upper magnet 103 and the lower magnet 107, adjacent magnets (those having a positional relationship between the magnets 103a and 103b) are magnetized in different directions from each other. Further, the opposing magnets (magnets 103a and 107a are in a positional relationship) are magnetized in the same direction. The first driving magnet is formed by the upper magnet 1033 and the lower magnet 1073. A second driving magnet is formed by the upper magnets 1031 and 1032 and the lower magnets 1071 and 1072.

Since a strong suction force is generated between the upper yoke 101 and the lower yoke 108, the main spacers 105a to 105c and the auxiliary spacers 104a and 104b are configured to maintain a predetermined distance. The predetermined interval referred to here is an interval such that the coil 205 and the flexible printed circuit board (FPC) 201 can be arranged between the upper magnets 103a to 103f and the lower magnets 107a to 107f and an appropriate gap can be secured. The main spacers 105a to 105c are provided with screw holes, and the upper yoke 101 is fixed to the main spacers 105a to 105c by screws 102a to 102c.

Rubber is installed on the body of the main spacers 105a to 105c to form a mechanical end (so-called stopper) that limits the movable range of the movable portion.

The base plate 110 and the lower yoke 108 are fixed by the screws 109a to 109c. The base plate 110 is fixed to the lower side of the main spacers 105a to 105c by screws (not shown). The above is the explanation of the fixed part.

Further, the image shake correction means 14 includes an FPC 201, position detection elements 202a to 202c, a first coil 2051, a second coil 2052, a coil 205 including a third coil 2053, a movable frame 206, and position detection elements 2071 to 2074. ing. The position detection elements 2071 and 2072 form a first position detection element pair, and the position detection elements 2073 and 2074 form a second position detection element pair. In the following, the position detection elements 2071 to 2074 are used. Together, it is the position detection element 207. The above is a member that moves with respect to the camera 1 at the time of image shake correction.

The movable frame 206 holds the image sensor 6 and is formed of magnesium die-cast or aluminum die-cast, and is lightweight and has high rigidity. The image sensor 6 can be translated and rotated by translating and rotating the movable frame 206. Position detection elements 202a and 202b are attached to the FPC201 and are fixed to the upper magnet 103 side of the movable frame 206. For the position detection elements 202a and 202b, Hall elements, which are magnetic detection sensors, are used so that the positions of the movable parts can be detected by using the above-mentioned magnetic circuit. Since the Hall element is small, it is arranged inside the windings of the coils 205a and 205b. In the present embodiment, the position detection elements 202a and 202b perform position detection in the X direction, which is the second direction, when IS_ON is performed.

Further, the position detection elements 2071 to 2074 are attached to the FPC 201 as shown in FIG. 2B, and are fixed at a position facing the position detection magnet 111 arranged on the base plate 110. By using the position detection elements 2071 and 2072, the position of the movable frame 206 in the Y-axis direction of FIG. 2A can be detected. By using the position detection elements 2073 and 2074, the position of the movable frame 206 in the X-axis direction of FIG. 2A can be detected. Details of position detection using the position detection elements 2071 to 2074 will be described later.

Further, the image sensor 6 and the coils 2051 to 2053 are connected to the FPC 201, and various signals are output to the camera system control unit 5 and the image processing unit 7 via the connector on the FPC 201. The above is the explanation of the movable part.

The balls 301a to 301c are sandwiched between the base plate 110 and the movable frame 206, guide the movable frame 206 in a plane orthogonal to the optical axis, and roll when the movable frame 206 moves to form a movable portion. Reduce drive resistance.

In the above configuration, by energizing the coil 205, a driving force (Lorentz force) according to Fleming's left-hand rule is generated and the movable portion can be moved. In each of the first to third magnetic circuits, a coil is arranged between magnets and is driven and controlled as an independent driving unit.

Further, the feedback control of the movable portion can be performed by using the signals of the position detection elements 202a to 202c described above.

Next, the position detection of the movable frame 206 by the position detection element 207 performed by the camera system control unit 5 will be described with reference to FIGS. 3 to 5. FIG. 3 shows the positional relationship between the position detection elements 2071 to 2074 and the position detection magnet 111 in a state where the movable portion is located at the center of the movable range without rotating, as viewed from the movable frame 206 side in the optical axis direction. It is a conceptual diagram. FIG. 4 is a schematic conceptual diagram showing the state of the magnetic flux density of the magnetic circuit composed of the position detection element 207 and the position detection magnet 111. FIG. 5 is a conceptual diagram illustrating a position detection method using the position detection elements 2073 and 2074.

In FIG. 3, a circle marked near the center of each position detection element indicates the position of the magnetically sensitive portion of the position detection element 207, which is a Hall element. Further, the letter "N" written in the center of the position detection magnet 111 is magnetized in the direction (parallel to the optical axis, thickness direction) in which the position detection magnet 111 is orthogonal to the x direction and the y direction. It shows that the front side is the north pole and the back side is the south pole. As described above, the rectangular position detection magnet 111 in the short side direction (y direction) is based on the magnetic flux density detected by the position detection elements 2071 and 2072 arranged apart from the magnet surface by a predetermined distance. The position of the movable frame 206 is detected. Similarly, with respect to the long side direction (x direction) of the position detection magnet 111, the movable frame 206 is based on the magnetic flux density detected by the position detection elements 2073 and 2074 arranged apart from the magnet surface by a predetermined distance. The position of is detected. As shown in FIG. 3, the position detection elements 2071 and 2072 are arranged in the y direction, and the position detection elements 2073 and 2074 are arranged in the x direction. Then, in the state shown in FIG. 3, the distance in the y direction between the magnetically sensitive portion (detection position) of the position detection element 2071 and the center of the position detection magnet 111 is the same as the magnetically sensitive portion (detection position) of the position detection element 2072. It is assumed that it is equal to the distance in the y direction from the center of the position detection magnet 111. Further, in the state shown in FIG. 3, the distance in the x direction between the magnetically sensitive portion (detection position) of the position detection element 2073 and the center of the position detection magnet 111 is the same as the magnetically sensitive portion (detection position) of the position detection element 2074. It is assumed that it is equal to the distance in the x direction from the center of the position detection magnet 111.

The solid line MB-B'shown in FIG. 4 is the magnetic flux density of the position detection magnet 111 observed in the cross section of BB' in FIG. 3, and the dotted line MC-C'is observed in the cross section of CC'in FIG. It shows the magnetic flux density of the position detection magnet 111. The magnetic flux density values (M2071 to M2074) marked with ◯ indicate the magnetic flux densities detected by the position detection elements 2071 to 2074, respectively.

In FIG. 5A, a region including M2073 and M2074 is cut out from the solid line MB-B'in FIG. 4, and the horizontal axis is the position of the movable frame 206 in the x direction, and the position of the movable frame 206 and the position detection element 2073. , 2074 shows the relationship of the magnetic flux density detected. As shown in FIG. 3, the magnetizing portion of the position detecting element 2073 and the magnetizing of the position detecting element 2073 from the center of the position detecting magnet 111 in a state where the movable portion is located at the center of the movable range without rotating. The distance to the part is equal. Therefore, when the movable portion is located at the center of the movable range without rotating, the magnetic flux density detected by the position detecting element 2073 and the magnetic flux density detected by the position detecting element 2074 are equal values. That is, the position of the movable frame 206 where M2073 and M2074 intersect in FIG. 5A is the central position of the movable range.

FIG. 5B is a plot of the ratio of the output difference ΔM2 and the output sum S2 of the position detection elements 2073 and 2074 at each position. More specifically, ΔM2 / S2 = (M2074-M2073) / (M2074 + M2073). ΔM2 is calculated as a value corresponding to the position of the movable frame 206 in the x direction. Further, by dividing ΔM2 by S2, the influence of the change component of the total sum of the magnetic flux density detection results due to the change in the environmental temperature is reduced. Even if the slope of the magnetic flux density detection result in FIG. 5A changes due to a change in the environmental temperature, it can be interrupted by the sum of the magnetic flux density detection results (corresponding to S2) under that temperature environment. It is standardized and the influence of temperature changes can be reduced. For this reason, when the camera system control unit 5 obtains ΔM2 / S2, even if the environmental temperature changes, the influence thereof is reduced, and an output corresponding to the position of the movable frame 206 can be obtained. With respect to the y direction, which is the first direction, the output signals of the position detection elements 2071 and 2072 can be used to obtain an output corresponding to the position of the movable frame 206 as in the x direction.

Next, the rotation detection of the movable frame 206 around the optical axis by the position detecting element 207 performed by the camera system control unit 5 will be described with reference to FIG. FIG. 6A is a diagram showing a view of the position detecting element 207 rotated by θ about the center of the position detecting magnet 111 from the same direction as in FIG. FIG. 6B shows the state of the magnetic flux density detected at this time, the magnetic flux density detected in the non-rotated state is indicated by ○, and the magnetic flux density detected in the rotated state by θ is indicated by ●. ing. Then, the distance from the detection position of the position detection elements 2071 and 2072 to the center of the position detection magnet 111 in the state shown in FIG. 3 is L1, and the distance from the detection position of the position detection elements 2073 and 2074 to the center of the position detection magnet 111. The distance is L2.

Due to the rotation, the detection positions of the position detection elements 2071 and 2072 move inward by L1 (1-cosθ) with respect to the detection position when the position detection magnet 111 is not rotated from the center (position detection magnet). Approaching 111). Similarly, the detection positions of the position detection elements 2073 and 2074 also move inward by L2 (1-cosθ). Since L1 (1-cosθ) <L2 (1-cosθ), it can be seen that there is a difference in the amount of change in the detected magnetic flux density. Therefore, the rotation of the movable frame 206 is detected by the camera system control unit 5 calculating (ΔM2-ΔM1) / (S2 + S1) (however, ΔM1 = M2072-M2071, S1 = M2072 + M2071). Similar to the position detection in each axial direction, ΔM2-ΔM1 detects the change in magnetic flux density, that is, the rotation of the movable frame 206, and S2 + S1 detects the influence of the change component of the sum of the magnetic flux density detection results due to the temperature change. Is mitigating.

Next, the position detection of the movable frame 206 by the position detection elements 202a and 202b will be described with reference to FIG. 7. FIG. 7A is a schematic view of the position detection element 202a, the first lower magnet portions 107a, 107b, and the coil 2051 as viewed from the movable frame 206 side in the optical axis direction. The position detection element 202a, which is a Hall element, is magnetized in the thickness direction and is located on the boundary between the first lower magnet portions 107a and 107b, which have a magnetic pole configuration like the letters "N" and "S" in the figure. doing. This represents when the movable frame 206 is located at the center of the movable range. When the coil 2051 is energized to drive the coil 2051 in the vertical direction (= x direction), the position of the position detecting element 202a also changes so as to straddle the boundary between the first lower magnet portions 107a and 107b. 7 (b) is a schematic view showing the state of the magnetic flux density MD-D'in the cross section of D-D'of FIG. 7 (a), and the first lower magnet portions 107a and 107b are shown by dotted lines. Since the magnetic flux density changes linearly across the boundary between the first lower magnet portions 107a and 107b in this way, the movable portion 206 is detected by the position detection element 202a to detect the magnetic flux density MD-D'. The position of is in the x direction can be obtained. As a matter of course, the position is uniquely determined within the range of linear change, and the movable frame 206 is designed to be driven and controlled within this range.

The image pickup apparatus 1000 properly uses the position detection system as described above based on the detection result of the image shake correction function detection process, that is, according to ON / OFF of the camera shake correction.

When the image shake correction function detection process detects that the camera shake correction is ON, the camera system control unit 5 uses the position detection elements 202a and 202b to perform drive control of the movable frame 206 while detecting the position in the x direction. Do. On the other hand, in the y direction, the position detection elements 2071 and 2072 are used to control the drive of the movable frame 206. Using the long side of the position detection magnet 111 for position detection in the y direction has the following advantages. First, even when the drive is performed in the x direction, the position detection elements 2071 and 2072 do not face the position detection magnet 111 because the y direction is the long side. Further, in the case of a shape such as the position detection magnet 111, the change in the magnetic flux density is gentler in the direction orthogonal to the long side, that is, in the y direction, so the position is detected by using the position detection elements 2071 and 2072. The range of high linearity is wide. Here, in order to simplify the configuration, the y-direction position detection when the image stabilization is ON was performed using the position detection elements 2071 and 2072, but the present invention is not limited to this, and the position detection elements 202a or 202b are separately contained in the coil 2053. A Hall element such as the above may be arranged.

When the image shake correction function detection process detects the camera shake correction OFF, the camera system control unit 5 uses the position detection element 207 to detect the position and rotation in the x and y directions while detecting the movable frame 206. Performs positioning control to fix the camera in a predetermined position. This positioning control prevents the movable frame 206 from translating and rotating when the image stabilizer is turned off. Consider the problems that may occur if this positioning control is not performed. The translation and rotation detection by the position detecting elements 202a and 202b is accurately performed if there is no change in the environmental temperature. However, when the environmental temperature changes, the magnetic flux densities of the upper magnet 103 and the lower magnet 107 change. Further, the output characteristics of the position detection elements 202a and 202b, which are Hall elements, also change. For this reason, the position detection result when the image stabilization is turned off, which is required to be stationary, fluctuates, and unnecessary driving occurs. When a long-second exposure is performed for taking a starry sky photograph or the like, due to this unnecessary drive, a star image that should be captured as a point image is imaged in an unnecessary drive form. On the other hand, as in the present embodiment, if the position detection is performed based on the ratio of the sum and difference of the position detection elements 2071 and 2072, which are a set of Hall elements, there is no problem with the change in the environmental temperature.

As described above, in the present embodiment, the influence of the output fluctuation of the position detection element is reduced by the simple configuration of two sets of position detection element pairs and one magnet, and the positions of the movable frame 206 in the x direction and the y direction and Rotation can be detected.

(Second Embodiment)
Subsequently, the image pickup apparatus 2000 according to the second embodiment of the present invention will be described with reference to FIGS. 8 to 11. Since the schematic configuration of the image pickup apparatus 2000 is the same as that of the imaging apparatus 1000, the configuration is omitted, and the configuration peculiar to the present embodiment will be described in detail.

FIG. 8A is an exploded perspective view of the image shake correction means 24 included in the image pickup apparatus 2000. FIG. 8B is a partially enlarged view of part A shown in FIG. 8A. Regarding the configuration of the image shake correction means 24, only the difference from the image shake correction means 14 of the image pickup apparatus 1000 will be described.

In the image shake correction means 24, the position detecting element 202c is arranged inside the winding of the coil 2053, and detects the position of the movable portion 206 in the y direction. Further, only the position detection elements 2071 and 2073 are arranged as the position detection elements 207 at positions facing the position detection magnets 111 arranged on the base plate 110. As described above, the number of position detecting elements in this embodiment is smaller than that in the first embodiment.

Position detection and positioning control in this embodiment will be described with reference to FIGS. 9 to 11. FIG. 9A shows the positional relationship between the position detection elements 2071 and 2073 and the position detection magnet 111 in a state where the movable portion is located at the center of the movable range without rotating, and the movable frame 206 in the optical axis direction. It is a conceptual diagram seen from the side. The position detection element 2071 detects the position near the long side of the position detection magnet, and the position detection element 2073 detects the position near the short side of the position detection magnet 111. In the present embodiment, the position detection magnet 111 has a rectangular shape when viewed from the optical axis direction, but the present invention is not limited to this, and the position detection magnet 111 may be square. FIG. 9B shows an optical axis of the position detection element 202c, the third lower magnet portions 107e and 107f, and the coil 2053 from the movable frame 206 side in a state where the movable portion is located at the center of the movable range without rotating. It is a schematic view seen in a direction. FIG. 10A is a schematic conceptual diagram showing the state of the magnetic flux density of the magnetic circuit composed of the position detection elements 2071 and 2073 and the position detection magnet 111. 10 (b) is a schematic view showing the state of the magnetic flux density MD-D'in the D-D'cross section of FIG. 9 (b). The third lower magnet portions 107e and 107f are shown by dotted lines.

In the present embodiment, the positioning control when the image runout correction is OFF is performed by using these configurations shown in FIG. 9 as in the first embodiment.

FIG. 11A shows the relationship between the position of the movable frame 206 and the magnetic flux density detected by the position detecting elements 202C and 2071, with the horizontal axis as the position of the movable frame 206 in the y direction.

In FIG. 11B, the value obtained by dividing ΔM1 which is the difference value between the magnetic flux densities M202C and M2071 by S1 which is the sum is plotted. Since the magnets that are the sources of the magnetic flux densities M202C and M2071 are different for driving and position detection, the magnetic flux densities change with different slopes. However, because it is linear, the difference values maintain linearity. Therefore, it is possible to detect the position change of the movable frame 206 by using ΔM1. Further, as in the first embodiment, it is possible to reduce the influence of the temperature changing component by S1. Similarly, in the x direction, the same position detection can be performed by using the position detection element 202a or 202b and the position detection element 2073. By using this position detection method, the camera system control unit 5 can accurately perform positioning control when the image shake correction is OFF. Further, the present embodiment also has the following advantages as compared with the first embodiment.

FIG. 12 is a schematic conceptual diagram showing a configuration for realizing the position detection method of the present embodiment as viewed from the optical axis direction. The line segment A is a straight line connecting the position detection elements 202b and 2073, which detect the position in the x direction and use the detection result for the positioning control. The line segment B is a straight line connecting the position detection elements 202c and 2071, which detect the position in the y direction and use the detection result for the positioning control. Further, the line segment C is a straight line connecting the position detection elements 2073 and 2074 used for the positioning control by detecting the position in the x direction in the first embodiment. Further, the line segment D is a straight line connecting the position detection elements 2071 and 2072 used for positioning control by detecting the position in the y direction in the first embodiment.

It can be seen that the intersections of the line segments C and D are the midpoints of both line segments. Therefore, it is not possible to detect the rotation around the midpoint by simply using the difference / sum of the position detection element pairs. Therefore, in the first embodiment, rotation is further detected using (ΔM2-ΔM1) / (S2 + S1). On the other hand, in this embodiment, the line segments A and B have no intersection. Therefore, the position of the movable frame 206 is fixed with respect to rotation only by performing positioning control for translation in the x direction with the position detection elements 202b and 2071 and positioning control for translation in the y direction with the position detection elements 202c and 2073. Therefore, positioning control becomes easier.

When the image shake correction function detecting means detects that the camera shake correction is ON, the camera system control unit 5 controls the drive of the movable frame 206 while detecting the positions in the x and y directions using the position detection elements 202a to 202c. It is something to do.

As described above, in the present embodiment, the influence of the output fluctuation of the position detection element is reduced by a simple configuration of two sets of position detection element pairs and one magnet, which also partially serve as a drive position detection element. The position and rotation of the movable frame 206 in the x-direction and the y-direction can be detected.

(Third Embodiment)
Subsequently, the image pickup apparatus 3000 according to the third embodiment of the present invention will be described with reference to FIGS. 13 to 15. Since the schematic configuration of the image pickup apparatus 3000 is the same as that of the imaging apparatus 1000, the configuration is omitted, and the configuration peculiar to the present embodiment will be described in detail. FIG. 13 is an exploded perspective view of the image shake correction means 34 included in the image pickup apparatus 3000. Unlike the first and second embodiments, the position detecting magnet 111 does not exist, and the position detecting element 202'is arranged inside the winding of the coil.

A position detection method for controlling the positioning of the movable frame 206 will be described with reference to FIGS. 14 and 15. FIG. 14A is a schematic view showing the arrangement of the lower magnets 107a and 107b, the position detection element 202'a, and the coil 2051 as viewed from the movable frame 206 side in the optical axis direction. FIG. 14B shows the magnetic flux density MD-D'detected by the position detecting element 202'a shown in FIG. 14A in the cross section DD'.

As shown by ◯ in FIG. 14A, the position detecting element 202'a is provided at two locations so that the magnetic sensing portions for detecting the magnetic flux density are arranged in the position detecting direction. Similar to the circle shown in FIG. 14 (a), the position corresponding to the magnetically sensitive portion of the position detection element 202'a of the magnetic flux density MD-D'shown by the solid line in FIG. 14 (b) is marked with a circle. is there. In the following, the magnetic flux density detected by the upper magnetic sensing portion in FIG. 14 is referred to as M202'a-a, and the magnetic flux density detected by the lower magnetic sensing portion is referred to as M202'a-b.

Since the lower magnets 107a and 107b are driving magnets, as shown in FIG. 14, two magnets in the magnetic pole directions opposite to each other are abutted and arranged. Therefore, M202'a-a and M202'a-b output negative values with the contact surfaces of the two magnets as boundaries. In particular, in the state as shown in FIG. 14 in which positioning control is performed, M202'a-a and M202'a-b have positive and negative outputs, respectively. Therefore, in the positioning control of the present embodiment, the output M202'ab | of the magnetically sensitive portion on the lower magnet 107b side of the position detecting element 202'a is made an absolute value (| M202'ab |). | M202'ab | corresponds to the magnetic flux density indicated by ● in FIG. 14 (b).

FIG. 15A shows the relationship between the position of the movable frame 206 and the magnetic flux densities M202'a-a and | M202'a-b | detected by the position detection element 202'a. In FIG. 15B, ΔM1 = | M202'ab | -M202'a-a, which is the difference value between the magnetic flux density | M202'a-b | and M202'a-a, is the sum of S1 = | The value divided by M202'a-b | + M202'a-a is plotted. Using the ΔM1 calculated in this way, it is possible to detect the position variation of the movable frame 206. Further, as in the first and second embodiments, S1 can reduce the influence of the temperature changing component. By using this position detection method, the camera system control unit 5 can accurately perform positioning control when the image shake correction is OFF.

When the image stabilization function detecting means detects that the image stabilization is ON, the camera system control unit 5 is movable while detecting the positions in the x and y directions using the position detection elements 202'a to 202'c. The drive control of the frame 206 is performed.

As described above, in the present embodiment, the influence of the output fluctuation of the position detection element is reduced by a simple configuration in which the position detection element other than the drive and the magnet are not separately provided, and the position of the movable frame 206 in the x direction and the y direction. And rotation can be detected.

In the present embodiment, an example in which each of the position detection elements 202'a to 202'c has two magnetically sensitive parts has been described, but since the position detection elements 202'a and 202'b have the same detection direction. The position detecting element may have two magnetically sensitive portions of only one of them.

It should be noted that each of the embodiments described above is merely an example and is only a representative example. In carrying out the present invention, various modifications and changes can be made to each embodiment and combinations of each embodiment are possible. Is. For example, in the above three embodiments, an example in which the present invention is applied to the position detection of the movable frame 206 holding the image sensor 6 has been described, but the present invention is used to detect the position of the correction lens included in the optical system 3 of the lens 2. The invention may be applied. The position of the correction lens may be detected by detecting the position of another member that moves integrally with the correction lens, such as a holding frame for holding the correction lens.

Further, in the above three embodiments, an example of performing position detection in the x-direction and the y-direction has been described, but even in a configuration in which the present invention is applied only to position detection in either the x-direction or the y-direction, conventionally. With a simpler configuration, position detection is possible with less influence of output fluctuations of the position detection element.

Further, in order to arrange the position detection element and the magnet so as to have the positional relationship shown in the above three embodiments, high-precision assembly is required. Therefore, in a configuration in which the positional relationship between the position detection element and the magnet deviates from the above three embodiments, the positional relationship shown in the above three embodiments is used as a reference, and the position is adjusted according to the amount of the positional deviation from the reference. The output of the detection element may be corrected.

Further, in the above three embodiments, an example in which a coil is provided in the movable portion and a magnet is provided in the fixed portion has been described, but if the configuration is such that a coil is provided in one of the fixed portion and the movable portion and a magnet is provided in the other. Often, a magnet may be provided in the movable portion and a coil may be provided in the fixed portion.

Further, the Hall element used in the above three embodiments is an example of a magnetic detection sensor, and other magnetic detection sensors may be used.

5 Camera system control unit 14, 24, 34 Image shake correction means 111 Position detection magnet 202, 202'Position detection element

Claims (19)

With the image sensor
A movable part that holds one of the image sensor and the image pickup optical system,
A fixed portion facing the movable portion and
A first coil provided on one of the movable portion and the fixed portion and generating a driving force in a first direction orthogonal to the optical axis of the photographing optical system by energization.
A second coil provided on one of the movable portion and the fixed portion and generating a driving force in a second direction orthogonal to the optical axis of the photographing optical system and the first direction.
A first magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A second magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A third magnet provided on the other side of the movable portion and the fixed portion and magnetized in a direction parallel to the optical axis of the photographing optical system.
It has a position detecting means for detecting the position of the movable portion with respect to the fixed portion.
The position detecting means is based on the output of two magnetic detection sensors provided on one of the movable portion and the fixed portion and arranged at positions facing the third magnet so as to line up in the first direction. The position of the movable portion with respect to the fixed portion in the first direction is detected, and the movable portion is provided on one of the movable portion and the fixed portion so as to be aligned in the second direction at a position facing the third magnet. An imaging device characterized in that the position of the movable portion in the second direction with respect to the fixed portion is detected based on the outputs of two magnetic detection sensors arranged in. The position detecting means detects the position of the movable portion in the first direction based on the sum and difference of the outputs of the two magnetic detection sensors arranged so as to be arranged in the first direction, and the first position is detected. The first aspect of claim 1, wherein the position of the movable portion in the second direction is detected based on the sum and difference of the outputs of the two magnetic detection sensors arranged so as to be arranged in two directions. Imaging device. The position detecting means is the difference between the outputs of the two magnetic detection sensors arranged in the first direction with respect to the sum of the outputs of the two magnetic detection sensors arranged in the first direction. Based on the ratio, the position of the movable part in the first direction is detected so as to be aligned in the second direction with respect to the sum of the outputs of the two magnetic detection sensors arranged so as to be aligned in the second direction. The imaging device according to claim 2, wherein the position of the movable portion in the second direction is detected based on the ratio of the difference between the outputs of the two magnetic detection sensors arranged in the above. The third magnet is rectangular and
In a state where the movable portion is located at the center of the movable range, the two magnetic detection sensors arranged so as to line up in the first direction are two sides of the third magnet parallel to the second direction. The two magnetic detection sensors facing each other and arranged so as to line up in the second direction are characterized in that they face each of the two sides of the third magnet parallel to the first direction. The imaging device according to any one of claims 1 to 3. The imaging device according to claim 4, wherein the third magnet has different lengths of two sides parallel to the first direction and two sides parallel to the second direction. The claim is characterized by having a control means for controlling the position of the movable portion by controlling the energization of at least one of the first coil and the second coil based on the detection result of the position detecting means. The imaging apparatus according to any one of 1 to 5. The control means is based on the outputs of two magnetic detection sensors in which the position detection means are arranged so as to line up in the first direction when the image shake correction function performed by moving the movable portion is OFF. The position of the movable part in the first direction and the position of the movable part in the second direction detected based on the outputs of the two magnetic detection sensors arranged so as to be aligned with the second direction. The imaging device according to claim 6, wherein the position of the movable portion is controlled by controlling the energization of at least one of the first coil and the second coil based on the above. A magnetic detection sensor provided on one of the movable portion and the fixed portion and arranged at a position facing the first magnet.
It has a magnetic detection sensor provided on one of the movable portion and the fixed portion and arranged at a position facing the second magnet.
The control means detects the position detection means based on the output of the magnetic detection sensor arranged at a position facing the first magnet when the image shake correction function performed by moving the movable portion is ON. Based on the position of the movable part in the first direction and the position of the movable part in the second direction detected based on the output of the magnetic detection sensor arranged at the position facing the second magnet. The imaging device according to claim 7, wherein the position of the movable portion is controlled by controlling the energization of at least one of the first coil and the second coil. Based on the outputs of the two magnetic detection sensors arranged in the first direction and the outputs of the two magnetic detection sensors arranged in the second direction, the movable portion with respect to the fixed portion. The imaging apparatus according to any one of claims 1 to 8, further comprising a rotation detecting means for detecting the rotation of the above. With the image sensor
A movable part that holds one of the image sensor and the image pickup optical system,
A fixed portion facing the movable portion and
A first coil provided on one of the movable portion and the fixed portion and generating a driving force in a first direction orthogonal to the optical axis of the photographing optical system by energization.
A second coil provided on one of the movable portion and the fixed portion and generating a driving force in a second direction orthogonal to the optical axis of the photographing optical system and the first direction.
A first magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A second magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A third magnet provided on the other side of the movable portion and the fixed portion and magnetized in a direction parallel to the optical axis of the photographing optical system.
It has a position detecting means for detecting the position of the movable portion with respect to the fixed portion.
The position detecting means is provided on one of the movable portion and the fixed portion and is provided on one of the output of the magnetic detection sensor provided at a position facing the third magnet and the movable portion and the fixed portion. An imaging device characterized in that the position of the movable portion in the first direction with respect to the fixed portion is detected based on the output of a magnetic detection sensor arranged at a position facing the first magnet. The position detecting means is provided on one of the movable portion and the fixed portion and is provided on one of the output of the magnetic detection sensor provided at a position facing the third magnet and the movable portion and the fixed portion. The claim is characterized in that the position of the movable portion in the first direction with respect to the fixed portion is detected based on the sum and difference of the outputs of the magnetic detection sensors arranged at positions facing the first magnet. 10. The imaging apparatus according to 10. The position detecting means is provided on one of the movable portion and the fixed portion and is provided on one of the output of the magnetic detection sensor provided at a position facing the third magnet and the movable portion and the fixed portion. A magnetic detection sensor provided at one of the movable portion and the fixed portion and arranged at a position facing the third magnet with respect to the sum of the outputs of the magnetic detection sensor arranged at a position facing the first magnet. Based on the ratio of the difference between the output and the output of the magnetic detection sensor provided on one of the movable portion and the fixed portion and arranged at a position facing the first magnet, the first of the movable portion with respect to the fixed portion. The imaging apparatus according to claim 11, wherein the position in one direction is detected. The claim is characterized by having a control means for controlling the position of the movable portion by controlling the energization of at least one of the first coil and the second coil based on the detection result of the position detecting means. 11. The imaging apparatus according to 11. The control means is magnetic detection provided at one of the movable portion and the fixed portion and arranged at a position facing the third magnet when the image shake correction function performed by moving the movable portion is OFF. The energization of the first coil is controlled based on the output of the sensor and the output of the magnetic detection sensor provided on one of the movable portion and the fixed portion and arranged at a position facing the first magnet. The imaging device according to claim 13, wherein the position of the movable portion is controlled. With the image sensor
A movable part that holds one of the image sensor and the image pickup optical system,
A fixed portion facing the movable portion and
A first coil provided on one of the movable portion and the fixed portion and generating a driving force in a first direction orthogonal to the optical axis of the photographing optical system by energization.
A second coil provided on one of the movable portion and the fixed portion and generating a driving force in a second direction orthogonal to the optical axis of the photographing optical system and the first direction.
A first magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A second magnet provided on the other side of the movable portion and the fixed portion and arranged at a position facing the first coil.
A magnetic detection sensor provided on one of the movable portion and the fixed portion and arranged at a position facing the first magnet.
It has a position detecting means for detecting the position of the movable portion with respect to the fixed portion.
The magnetic detection sensor has two magnetic sensing portions arranged in the first direction.
The position detecting means is an imaging device that detects the position of the movable portion in the first direction with respect to the fixed portion based on the outputs of the two magnetic sensing portions of the magnetic detection sensor. The claim is characterized in that the position detecting means detects the position of the movable portion in the first direction with respect to the fixed portion based on the sum and difference of the outputs of the two magnetic sensing portions of the magnetic detection sensor. Item 15. The imaging device according to item 15. The position detecting means said that the movable portion with respect to the fixed portion is based on the ratio of the difference between the outputs of the two magnetic sensing portions of the magnetic detection sensor to the output of the two magnetic sensing portions of the magnetic detection sensor. The imaging apparatus according to claim 16, wherein the position in the first direction is detected. The claim is characterized by having a control means for controlling the position of the movable portion by controlling the energization of at least one of the first coil and the second coil based on the detection result of the position detecting means. The imaging apparatus according to any one of 15 to 17. The control means said that when the image shake correction function performed by moving the movable portion is OFF, the position detecting means detects the movable portion based on the outputs of the two magnetic sensing portions of the magnetic detection sensor. The imaging apparatus according to claim 18, wherein the position of the movable portion is controlled by controlling the energization of the first coil based on the position in the first direction.

Images