JP7346081B2 - Imaging device - Google Patents

Description

The present invention relates to an imaging device, and particularly to position detection of an image blur correction mechanism.

In imaging devices such as digital cameras, many techniques have been disclosed for correcting the effects of shake on the device by moving an imaging device such as a CMOS sensor or some optical elements of the photographing optical system in a direction perpendicular to the optical axis. There is. In Patent Document 1, a voice coil motor composed of a permanent magnet and a coil is used to make an image sensor movable and movable within a plane perpendicular to the optical axis of a photographic lens. By using the image stabilization means as in Patent Document 1, even if unnecessary shake is applied to the imaging device, drive control is performed to cancel it, making it possible to obtain photos and videos without the influence of shake. .

Unexamined Japanese Patent Publication No. 2017-15900

The imaging device described in Patent Document 1 detects the position of a movable part using a position detection means, and performs drive control by feeding back the detection result. At this time, a Hall sensor is used as the position detection means, but when implementing the arrangement of Hall sensors as in Patent Document 1, it is necessary to arrange a plurality of magnets dedicated to position detection. This configuration has a plurality of magnets dedicated to position detection, which adversely affects miniaturization and weight reduction of the imaging device.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an imaging device that has a simple configuration and is capable of detecting the position of a movable part while reducing the influence of output fluctuations of a position detecting means.

In order to achieve the above object, an imaging device according to the present invention includes an imaging element, a movable part that holds one of the imaging element and the imaging optical system, a fixed part facing the movable part, the movable part and the imaging optical system. one first coil provided on one of the fixed parts and generating a driving force in a first direction perpendicular to the optical axis of the imaging optical system when energized; and one first coil provided on one of the movable part and the fixed part. a second coil which is provided on the other of the movable part and the fixed part and which generates a driving force in a second direction perpendicular to the optical axis of the imaging optical system and the first direction; a first magnet disposed at a position facing the first coil; a second magnet disposed on the other of the movable part and the fixed part and disposed at a position facing the second coil; a third magnet provided on the other of the movable part and the fixed part and magnetized in a direction parallel to the optical axis of the imaging optical system; and a position detection for detecting the position of the movable part with respect to the fixed part. means, and the position detecting means includes two magnets provided on one of the movable part and the fixed part and arranged to be aligned in the first direction at a position facing the third magnet. Based on the output of the detection sensor, the position of the movable part in the first direction with respect to the fixed part is detected, and the position of the movable part in the first direction, which is provided on one of the movable part and the fixed part, is located at a position facing the third magnet. The position of the movable part in the second direction with respect to the fixed part is detected based on the outputs of two magnetic detection sensors arranged in the second direction.

According to the present invention, it is possible to provide an imaging device that can detect the position of a movable part with a simple configuration while reducing the influence of output fluctuations of the position detection means.

FIG. 1 is a diagram illustrating an imaging device 1000 according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an image blur correction means 14 according to the first embodiment of the present invention. 5 is a diagram showing the positional relationship between position detection elements 2071 to 2074 and position detection magnet 111. FIG. FIG. 3 is a diagram showing the magnetic flux density of a magnetic circuit composed of a position detection element 207 and a position detection magnet 111. FIG. 7 is a diagram illustrating a position detection method using position detection elements 2073 and 2074. 7 is a diagram showing the state of the magnetic flux density of the position detection element 207 rotated by θ around the center of the position detection magnet 111. FIG. 7 is a diagram showing the positional relationship between first lower magnet portions 107a, 107b and a coil 2051. FIG. FIG. 3 is a diagram illustrating an image blur correction means 24 according to a second embodiment of the present invention. It is a figure showing the positional relationship of position detection elements 2071 and 2073 and position detection magnet 111. FIG. 3 is a diagram showing the magnetic flux density of a magnetic circuit composed of position detection elements 2071 and 2073 and a position detection magnet 111. It is a diagram showing the relationship between the magnetic flux density detected by the position detection element 2071 and the magnetic flux density detected by the position detection element 202c. It is a figure showing the positional relationship of position detection elements 2071 and 2073 and position detection elements 202b and 202c. FIG. 7 is a diagram illustrating an image blur correction unit 34 according to a third embodiment of the present invention. It is a figure showing the positional relationship of lower magnets 107a and 107b, position detection element 202'a, and 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)
An imaging device 1000 according to a first embodiment of the present invention will be described using FIG. 1.

FIG. 1A is a central sectional view of the imaging device 1000, and FIG. 1B is a block diagram showing the electrical configuration of the imaging device 1000. Components with the same reference numerals in FIG. 1(a) and FIG. 1(b) correspond to each other.

The imaging device 1000 includes a camera 1 and a lens 2 that is detachable 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 according to the light flux transmitted through the lens 2, which is an imaging optical system, and received. It is equipped with an electrical contact 11 used for communication with the lens 2. Furthermore, the camera 1 includes an image blur correction means 14 that optically corrects the image blur of the subject image formed on the image sensor 6, a motion detection means 15 that detects the movement of the imaging device 1000 using a gyro sensor, etc. A shutter mechanism 16 is provided to control the exposure time of 6.

The lens 2 drives each part of the optical system 3, including an optical system 3 that includes a focus lens used for focus adjustment, an aperture mechanism, a correction lens used for image stabilization, etc., a lens system control section 12 such as a CPU that controls the entire lens 2, and other parts of the optical system 3. The lens driving means 13 is provided for driving the lens.

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

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

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

Note that the motion detection means 15 detects the movement of the camera 1 around the photographing optical axis 4 and the movement of the camera 1 in a first direction and a second direction that are orthogonal to the photographing optical axis 4 and mutually orthogonal. .

The image blur correction means 14 is a mechanism that translates the image sensor 6 in a plane perpendicular to the photographing optical axis 4 and rotates it around the photographing optical axis 4 in order to reduce image shake of the subject image.

The camera system control unit 5 performs image stabilization function detection processing that detects whether the imaging device 1000 is fixed to a tripod or the like and detects a user's instruction to stop the camera shake correction function. When the stoppage of the image stabilization function (IS_OFF state) is detected in the image stabilization function detection process, the correction lens and the image sensor 6 included in the optical system 3 of the lens 2 are controlled to be positioned at predetermined positions. On the other hand, when activation of the image stabilization function (IS_ON state) is detected in the image stabilization function detection process, the correction lens and the image sensor 6 included in the optical system 3 are activated by the lens system control unit 12 and camera system control unit 5. The drive is controlled according to instructions.

Next, the configuration of the image blur correction means 14 will be explained using FIG. 2.

FIG. 2(a) is an exploded perspective view of the image blur correction means 14, and FIG. 2(b) is a partially enlarged view of section A shown in FIG. 2(a). In FIG. 2(a), parts that do not move with respect to the camera 1 during image shake correction (=fixed parts) are numbered in the 100s, and members that move (=movable parts) are numbered in the 200s. is attached. Furthermore, the ball, which is a member disposed between the fixed part and the movable part, is numbered in the 300s.

The image blur correction means 14 includes an upper yoke 101, screws 102a to 102c, a first upper magnet section 1031 consisting of magnets 103a and 103b, a second upper magnet section 1032 consisting of magnets 103c and 103d, and a third upper magnet section 1032 consisting of magnets 103e and 103f. It has an upper magnet part 1033. Hereinafter, the first upper magnet part 1031, the second upper magnet part 1032, and the third upper magnet part 1033 will be collectively referred to as the upper magnet 103.

Furthermore, a third lower magnet part 1073 is made up of auxiliary spacers 104a, 104b, a first lower magnet part 1071 made of main spacers 105a to 105c, 107a, 107b, a second lower magnet part 1072 made of 107c, 107d, 107e, 107f. have. Below, the first lower magnet part 1071, the second lower magnet part 1072, and the third lower magnet part 1073 are collectively referred to as the lower magnet 107.

Furthermore, it has a lower yoke 108, screws 109a to 109c, a base plate 110, and a position detection magnet 111. The above are members that do not move with respect to the camera 1 during image blur correction.

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

The upper magnets 103a to 103f are adhesively fixed to the upper yoke 101 in a attracted state. The lower magnets 107a to 107f are adhesively fixed to the lower yoke 108 in a attracted state. The upper magnets 103a to 103f and the lower magnets 107a to 107f are each magnetized in a direction parallel to the optical axis (in the direction of the dashed-dotted line in FIG. 2(a)). In the upper magnet 103 and the lower magnet 107, adjacent magnets (those in the positional relationship of magnets 103a and 103b) are magnetized in different directions. Moreover, opposing magnets (those in the positional relationship of magnets 103a and 107a) are magnetized in the same direction. The upper magnet 1033 and the lower magnet 1073 form a first driving magnet. The upper magnets 1031 and 1032 and the lower magnets 1071 and 1072 form a second driving magnet.

Since a strong suction force is generated between the upper yoke 101 and the lower yoke 108, a predetermined distance is maintained between the main spacers 105a to 105c and the auxiliary spacers 104a and 104b. The predetermined spacing here is a spacing that allows the coil 205 and the flexible printed circuit board (FPC) 201 to be arranged between the upper magnets 103a to 103f and the lower magnets 107a to 107f and to ensure an appropriate gap. 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 bodies of the main spacers 105a to 105c, forming mechanical ends (so-called stoppers) that limit the movable range of the movable parts.

The base plate 110 and the lower yoke 108 are fixed by 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 blur correction means 14 includes an FPC 201, position detection elements 202a to 202c, a coil 205 consisting of a first coil 2051, a second coil 2052, and a third coil 2053, a movable frame 206, and position detection elements 2071 to 2074. ing. The position detection elements 2071 and 2072 constitute a first position detection element pair, and the position detection elements 2073 and 2074 constitute a second position detection element pair. Together, they form a position detection element 207. The above are the members that move relative to the camera 1 during image blur correction.

The movable frame 206 holds the image sensor 6 and is made of die-cast magnesium or die-cast aluminum, and is lightweight and highly rigid. By translating and rotating the movable frame 206, the image sensor 6 can be translated and rotated. Position detection elements 202a and 202b are attached to the FPC 201, 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 position of the movable part can be detected using the above-described magnetic circuit. Since the Hall element is small, it is placed inside the windings of the coils 205a and 205b. In this embodiment, when IS_ON, the position detection elements 202a and 202b perform position detection in the X direction, which is the second direction.

Further, position detection elements 2071 to 2074 are attached to the FPC 201 as shown in FIG. 2(b), and are fixed at positions facing the position detection magnet 111 disposed 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 in FIG. 2(a) can be detected. By using the position detection elements 2073 and 2074, the position of the movable frame 206 in the X-axis direction in FIG. 2(a) can be detected. Details of position detection using the position detection elements 2071 to 2074 will be described later.

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

The balls 301a to 301c are held between the base plate 110 and the movable frame 206, guide the movable frame 206 in a plane perpendicular to the optical axis, and roll when the movable frame 206 moves, thereby controlling the movable part. Reduces driving resistance.

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

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

Next, position detection of the movable frame 206 by the position detection element 207 performed by the camera system control unit 5 will be described using FIGS. 3 to 5. FIG. 3 shows the positional relationship between the position detection elements 2071 to 2074 and the position detection magnet 111, viewed from the movable frame 206 side in the optical axis direction, in a state where the movable part is located at the center of the movable range without rotation. This is a conceptual diagram. FIG. 4 is a schematic conceptual diagram showing 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 position detection elements 2073 and 2074.

In FIG. 3, the circle marked near the center of each position detection element indicates the position of the magnetic sensing part of the position detection element 207, which is a Hall element. Moreover, the letter "N" written in the center of the position detection magnet 111 indicates that the position detection magnet 111 is magnetized in a direction perpendicular to the x direction and the y direction (direction parallel to the optical axis, thickness direction). This shows that the north pole is at the front and the south pole is at the back. As described above, the short side direction (y direction) of the rectangular position detection magnet 111 is based on the magnetic flux density detected by the position detection elements 2071 and 2072 that are arranged a predetermined distance from the magnet surface. The position of the movable frame 206 is detected. Similarly, in the long side direction (x direction) of the position detection magnet 111, the movable frame 206 The position of is detected. Note that, as shown in FIG. 3, the position detection elements 2071 and 2072 are lined up in the y direction, and the position detection elements 2073 and 2074 are lined up in the x direction. In the state shown in FIG. 3, the distance in the y direction between the magnetic sensing part (detection position) of the position detection element 2071 and the center of the position detection magnet 111 is the same as the distance in the y direction between the magnetic sensing part (detection position) of the position detection element 2072 It is assumed to be equal to the distance in the y direction from the center of the position detection magnet 111. In addition, in the state shown in FIG. 3, the distance in the x direction between the magnetic sensing part (detection position) of the position detection element 2073 and the center of the position detection magnet 111 is the same as the distance between the magnetic sensing part (detection position) of the position detection element 2074 and It is assumed to be 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 at the BB' cross section in FIG. 3, and the dotted line MC-C' is observed at the CC' cross section in FIG. The magnetic flux density of the position detection magnet 111 is shown. Further, the magnetic flux density values marked with ◯ (M2071 to M2074) indicate the magnetic flux densities detected by the position detection elements 2071 to 2074, respectively.

FIG. 5A shows the position of the movable frame 206 and the position detection element 2073 by cutting out a region including M2073 and M2074 from the solid line MB-B' in FIG. , 2074. As shown in FIG. 3, the magnetically sensitive part of the position detecting element 2073 and the magnetically sensitive part of the position detecting element 2073 from the center of the position detecting magnet 111 when the movable part is located at the center of the movable range without rotating. The distances to the parts are equal. Therefore, when the movable part is located at the center of the movable range without rotating, the magnetic flux density detected by the position detection element 2073 and the magnetic flux density detected by the position detection element 2074 have the same value. That is, the position of the movable frame 206 where M2073 and M2074 intersect in FIG. 5(a) is the center position of the movable range.

FIG. 5(b) is a plot of the ratio between 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 magnetic flux density detection results due to changes in environmental temperature is reduced. Even if the slope of the magnetic flux density detection result in Figure 5(a) changes due to a change in the environmental temperature, it can be divided by the sum of the magnetic flux density detection results (= equivalent to S2) under that temperature environment. It is standardized and the effects of temperature changes can be reduced. For these reasons, by determining ΔM2/S2 by the camera system control unit 5, even if the environmental temperature changes, the influence thereof can be reduced and an output corresponding to the position of the movable frame 206 can be obtained. Regarding the y direction, which is the first direction, by using the output signals of the position detection elements 2071 and 2072, an output corresponding to the position of the movable frame 206 can be obtained as in the x direction.

Next, the rotation detection around the optical axis of the movable frame 206 by the position detection element 207 performed by the camera system control unit 5 will be explained using FIG. FIG. 6A is a diagram showing the position detection element 207 rotated by θ around the center of the position detection magnet 111 as seen from the same direction as FIG. Figure 6(b) shows the state of the magnetic flux density detected at this time. ing. Then, L1 is the distance from the detection positions of the position detection elements 2071, 2072 to the center of the position detection magnet 111 in the state shown in FIG. The distance is L2.

Due to the rotation, the detection positions of the position detection elements 2071 and 2072 move inward by L1 (1-cos θ) from the center of the position detection magnet 111 when the position detection magnet 111 is not rotated. 111). The detection positions of position detection elements 2073 and 2074 similarly move inward by L2 (1-cos θ). Since L1(1-cosθ)<L2(1-cosθ), it can be seen that there is also 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 by calculating (ΔM2-ΔM1)/(S2+S1) (where ΔM1=M2072-M2071, S1=M2072+M2071). Similar to the position detection in each axis 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 temperature change. is reduced.

Next, position detection of the movable frame 206 by the position detection elements 202a and 202b will be explained using FIG. FIG. 7A is a schematic diagram of the position detection element 202a, the first lower magnet parts 107a and 107b, and the coil 2051 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 parts 107a and 107b, which have magnetic pole configurations like the letters "N" and "S" in the figure. are doing. This represents when the movable frame 206 is located at the center of the movable range. When the coil 2051 is driven in the vertical direction (=x direction) in FIG. 7 by energizing the coil 2051, the position of the position detection element 202a also changes so as to straddle the boundary between the first lower magnet parts 107a and 107b. FIG. 7(b) is a schematic diagram showing the magnetic flux density MD-D' in the DD' cross section of FIG. 7(a), and the first lower magnet portions 107a and 107b are indicated by dotted lines. As described above, since the magnetic flux density changes linearly across the boundary between the first lower magnet parts 107a and 107b, by detecting this magnetic flux density MD-D' with the position detection element 202a, the movable part 206 Find the position in the x direction. Naturally, the position is uniquely determined within the range of linear change, and the movable frame 206 is designed to be drive-controlled within this range.

The imaging apparatus 1000 selectively uses the position detection system as described above based on the detection result of the image blur correction function detection process, that is, depending on whether camera shake correction is turned on or off.

When the image stabilization function detection process 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 position in the x direction using the position detection elements 202a and 202b. conduct. On the other hand, in the y direction, drive control of the movable frame 206 is performed using position detection elements 2071 and 2072. Utilizing the long side of the position detection magnet 111 for position detection in the y direction has the following advantages. First, even when driving is performed in the x direction, since the long side is in the y direction, a situation in which the position detection elements 2071 and 2072 do not face the position detection magnet 111 does not occur. In addition, in the case of a shape like the position detection magnet 111, the change in magnetic flux density is slower in the direction perpendicular to the long side, that is, in the y direction, so position detection is performed using the position detection elements 2071 and 2072. Wide range of high linearity. Here, in order to simplify the configuration, position detection in the y direction when image stabilization is turned on is performed using position detection elements 2071 and 2072, but the present invention is not limited to this. A Hall element such as the one shown in FIG.

When the image stabilization function detection process detects that the camera shake correction is OFF, the camera system control unit 5 uses the position detection element 207 to detect the position and rotation of the movable frame 206 in the x and y directions. Positioning control is performed to fix the device in a predetermined position. This positioning control prevents the movable frame 206 from being translated or rotated when the image stabilization is turned off. Let us consider the problems that may occur if this positioning control is not performed. Detection of translation and rotation by the position detection elements 202a and 202b is performed accurately as long as 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. Furthermore, 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 camera shake correction is turned off, which requires the camera to remain stationary, fluctuates, resulting in unnecessary driving. When performing long exposures, such as when photographing the starry sky, this unnecessary drive causes a star image that should be captured as a point image to be formed in the form of an unnecessary drive. On the other hand, if position detection is performed based on the ratio of the sum and difference of the position detection elements 2071 and 2072, which are a pair of Hall elements, as in this embodiment, no problem will arise regarding changes in the environmental temperature.

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

(Second embodiment)
Next, an imaging device 2000 according to a second embodiment of the present invention will be described using FIGS. 8 to 11. Since the general configuration of the imaging device 2000 is the same as that of the imaging device 1000, it will be omitted, and the configuration unique to this embodiment will be described in detail.

FIG. 8A is an exploded perspective view of the image blur correction means 24 included in the imaging apparatus 2000. FIG. 8(b) is a partially enlarged view of section A shown in FIG. 8(a). Regarding the configuration of the image shake correction means 24, only the differences from the image shake correction means 14 of the imaging apparatus 1000 will be explained.

In the image blur correction means 24, a position detection element 202c is arranged inside the winding of the coil 2053, and detects the position of the movable part 206 in the y direction. Moreover, only position detection elements 2071 and 2073 are disposed as the position detection element 207 at a position facing the position detection magnet 111 disposed on the base plate 110. As described above, this embodiment has fewer position detection elements than the first embodiment.

Position detection and positioning control in this embodiment will be explained using 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 the state where the movable part does not rotate and is located at the center of the movable range. It is a conceptual diagram seen from the side. The position detection element 2071 performs position detection near the long side of the position detection magnet, and the position detection element 2073 performs position detection near the short side of the position detection magnet 111. In this embodiment, the position detection magnet 111 has a rectangular shape when viewed from the optical axis direction, but is not limited to this, and may be square. FIG. 9(b) shows the position detection element 202c, the third lower magnet parts 107e and 107f, and the coil 2053 from the movable frame 206 side on the optical axis in a state where the movable part is located at the center of the movable range without rotating. It is a schematic diagram seen in the direction. FIG. 10A is a schematic conceptual diagram showing the magnetic flux density of the magnetic circuit composed of the position detection elements 2071 and 2073 and the position detection magnet 111. FIG. 10(b) is a schematic diagram showing the magnetic flux density MD-D' in the DD' cross section of FIG. 9(b). The third lower magnet portions 107e and 107f are indicated by dotted lines.

In this embodiment, using these configurations shown in FIG. 9, positioning control is performed when image blur correction is OFF, similarly to 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 detection elements 202C and 2071, with the horizontal axis representing the position of the movable frame 206 in the y direction.

In FIG. 11(b), a 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 magnetic flux densities M202C and M2071 are produced by different magnets for driving and position detection, the magnetic flux densities change with different slopes. However, since it is linear, the difference value maintains linearity. Therefore, it becomes possible to detect the positional fluctuation of the movable frame 206 using ΔM1. Further, as in the first embodiment, it is possible to reduce the influence of the temperature change component by S1. Similar position detection in the x direction is also possible using the position detection element 202a or 202b and the position detection element 2073. Using this position detection method, the camera system control section 5 can accurately perform positioning control when image blur correction is OFF. Furthermore, the present embodiment also has the following advantages compared to the first embodiment.

FIG. 12 is a schematic conceptual diagram showing a configuration for realizing the position detection method of this embodiment, as viewed from the optical axis direction. A line segment A is a straight line connecting the position detection elements 202b and 2073 that perform position detection in the x direction and use the detection results for positioning control. Line segment B is a straight line that connects the position detection elements 202c and 2071 that perform position detection in the y direction and use the detection results for positioning control. Furthermore, line segment C is a straight line connecting position detection elements 2073 and 2074 that perform position detection in the x direction in the first embodiment and use the detection results for positioning control. Furthermore, line segment D is a straight line connecting position detection elements 2071 and 2072 that perform position detection in the y direction in the first embodiment and use the detection results for positioning control.

It can be seen that the intersection of line segments C and D is the midpoint of both line segments. Therefore, rotation around this midpoint cannot be detected simply by using the difference/sum of the pair of position detection elements. Therefore, in the first embodiment, rotation is further detected using (ΔM2-ΔM1)/(S2+S1). On the other hand, in this embodiment, line segments A and B do not intersect. Therefore, the position of the movable frame 206 can be determined by simply performing positioning control for translation in the x direction using the position detection elements 202b and 2073 , and positioning control for translation in the y direction using the position detection elements 202c and 2071 . is also fixed, making positioning control easier.

When the image stabilization function detection 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 position in the x and y directions using the position detection elements 202a to 202c. It is something to do.

As described above, in this embodiment, the influence of output fluctuations of the position detecting elements is reduced using a simple configuration consisting of two position detecting element pairs, which partially serve as position detecting elements for driving, and one magnet. The position and rotation of the movable frame 206 in the x and y directions can be detected.

(Third embodiment)
Next, an imaging device 3000 according to a third embodiment of the present invention will be described using FIGS. 13 to 15. The schematic configuration of the imaging device 3000 is the same as that of the imaging device 1000, so the description thereof will be omitted, and the configuration unique to this embodiment will be described in detail. FIG. 13 is an exploded perspective view of the image blur correction means 34 included in the imaging device 3000. Unlike the first and second embodiments, there is no position detection magnet 111, and both position detection elements 202' are arranged inside the windings of the coils.

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

The position detection element 202'a has two locations such that the magnetic sensing portions for detecting magnetic flux density are lined up in the position detection direction, as indicated by the circles in FIG. 14(a). Similar to the ○ shown in FIG. 14(a), the ○ is placed at the position corresponding to the magnetic sensing part of the position detection element 202′a of the magnetic flux density MD-D′ shown by the solid line in FIG. 14(b). be. In the following, in FIG. 14, the magnetic flux density detected by the upper magnetic sensing part is M202'a-a, and the magnetic flux density detected by the lower magnetic sensing part is M202'a-b.

Since the lower magnets 107a and 107b are drive magnets, two magnets with opposite magnetic pole directions are placed in contact with each other, as shown in FIG. Therefore, M202'a-a and M202'a-b output negative values with the boundary between the contact surfaces of the two magnets. In particular, in the state shown in FIG. 14 where positioning control is performed, M202'a-a and M202'a-b have positive and negative outputs, respectively. Therefore, in the positioning control of this embodiment, the outputs M202'a-b of the magnetic sensing portions on the lower magnet 107b side of the position detection element 202'a are converted into absolute values (|M202'a-b|). |M202'a-b| corresponds to the magnetic flux density indicated by ● in FIG. 14(b).

FIG. 15(a) shows the relationship between the position of the movable frame 206 and the magnetic flux density M202'a-a, |M202'a-b| detected by the position detection element 202'a. FIG. 15(b) shows the sum of ΔM1=|M202′a-b|−M202′a-a, which is the difference value between the magnetic flux density |M202′a-b| and M202′a-a, S1=| The value divided by M202'a-b|+M202'a-a is plotted. Using ΔM1 calculated in this way, it is possible to detect the positional fluctuation of the movable frame 206. Further, as in the first and second embodiments, it is possible to reduce the influence of the temperature change component by S1. Using this position detection method, the camera system control section 5 can accurately perform positioning control when image blur correction is OFF.

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

As described above, in this embodiment, the influence of output fluctuations of the position detecting element is reduced and the position of the movable frame 206 in the x and y directions is reduced by using a simple configuration that does not separately provide a position detecting element and a magnet for purposes other than driving. and rotation detection.

In this embodiment, an example has been described in which each of the position detection elements 202'a to 202'c has two magnetic sensing parts, but since the position detection elements 202'a and 202'b have the same detection direction, A position detection element may have only one of the two magnetic sensing parts.

The embodiments described above are merely examples and representative examples, and various modifications and changes to each embodiment and combinations of the embodiments are possible when implementing the present invention. It is. For example, in the above three embodiments, an example was described in which the present invention is applied to detecting the position of the movable frame 206 that holds the image sensor 6, but the present invention is applied to detecting the position of the correction lens included in the optical system 3 of the lens 2. The invention may be applied. Note that 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 that holds the correction lens.

Further, in the above three embodiments, an example was explained in which position detection is performed in the x direction and y direction, but even if the present invention is applied to position detection only in either the x direction or the y direction, it is possible to With a relatively simple configuration, it is possible to perform position detection with reduced influence of output fluctuations of the position detection element.

Further, in order to arrange the position detection element and the magnet in the positional relationship shown in the three embodiments described above, highly accurate assembly is required. Therefore, in a configuration in which the positional relationship between the position detection element and the magnet is shifted from that of the three embodiments described above, the positional relationship shown in the three embodiments described above is used as a reference, and the position is adjusted according to the amount of positional deviation from the reference. The output of the detection element may be corrected.

Further, in the above three embodiments, an example was explained in which a coil is provided in the movable part and a magnet is provided in the fixed part, but if the structure is such that a coil is provided in one of the fixed part and the movable part and a magnet is provided in the other. It is also possible to have a structure in which a magnet is provided in the movable part and a coil is provided in the fixed part.

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

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

Claims (19)

An image sensor and
a movable part that holds one of the imaging element and the imaging optical system;
a fixed part facing the movable part;
one first coil that is provided on one of the movable part and the fixed part and generates a driving force in a first direction perpendicular to the optical axis of the imaging optical system when energized;
a second coil that is provided on one of the movable part and the fixed part and generates a driving force in a second direction perpendicular to the optical axis of the imaging optical system and the first direction;
a first magnet provided on the other of the movable part and the fixed part and disposed at a position facing the first coil;
a second magnet provided on the other of the movable part and the fixed part and located at a position facing the second coil;
a third magnet provided on the other of the movable part and the fixed part and magnetized in a direction parallel to the optical axis of the imaging optical system;
position detection means for detecting the position of the movable part with respect to the fixed part,
The position detection means is based on the output of two magnetic detection sensors provided on one of the movable part and the fixed part and arranged in a position facing the third magnet so as to be aligned in the first direction. , detecting the position of the movable part in the first direction with respect to the fixed part, and aligning it in the second direction at a position facing the third magnet provided on one of the movable part and the fixed part. An imaging device characterized in that a position of the movable part in the second direction with respect to the fixed part is detected based on outputs of two magnetic detection sensors arranged at the fixed part. The position detection means detects the position of the movable part in the first direction based on the sum and difference of outputs of two magnetic detection sensors arranged in the first direction, and detects the position of the movable part in the first direction. 2. The position of the movable part in the second direction is detected based on the sum and difference of outputs of two magnetic detection sensors arranged in parallel in the second direction. Imaging device. The position detection means detects a difference between outputs of the two magnetic detection sensors arranged in the first direction with respect to a sum of outputs of the two magnetic detection sensors arranged in the first direction. The position of the movable part in the first direction is detected based on the ratio, and the position of the movable part in the second direction is detected relative to the sum of the outputs of two magnetic detection sensors arranged in the second direction. 3. The imaging device according to claim 2, wherein the position of the movable part in the second direction is detected based on a ratio of differences in outputs of two magnetic detection sensors arranged in the second direction. The third magnet is rectangular,
In a state where the movable part is located at the center of the movable range, the two magnetic detection sensors arranged in line in the first direction are arranged on two sides of the third magnet parallel to the second direction. The two magnetic detection sensors, which are arranged to face each other and line up in the second direction, respectively face two sides of the third magnet parallel to the first direction. An imaging device according to any one of claims 1 to 3. 5. The imaging device according to claim 4, wherein the third magnet has two sides parallel to the first direction and two sides parallel to the second direction that are different in length. 2. The movable portion according to claim 1, further comprising a control means for controlling energization of at least one of the first coil and the second coil to control the position of the movable part based on the detection result of the position detection means. 6. The imaging device according to any one of 1 to 5. When the image stabilization function performed by moving the movable part is OFF, the control means is configured to control the position detection means based on the outputs of the two magnetic detection sensors arranged so that the position detection means are aligned in the first direction. a detected position of the movable part in the first direction and a position of the movable part in the second direction detected based on outputs of two magnetic detection sensors arranged in parallel in the second direction; The imaging device according to claim 6, wherein the position of the movable part is controlled by controlling energization of at least one of the first coil and the second coil based on the following. a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the first magnet;
a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the second magnet;
The control means detects the position based on the output of a magnetic detection sensor disposed at a position facing the first magnet when the image stabilization function performed by moving the movable part 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 a magnetic detection sensor disposed at a position facing the second magnet. The imaging device according to claim 7, wherein the position of the movable part is controlled by controlling energization of at least one of the first coil and the second coil. The movable portion relative to the fixed portion is 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. 9. The imaging apparatus according to claim 1, further comprising rotation detection means for detecting rotation of the image pickup apparatus. An image sensor and
a movable part that holds one of the imaging element and the imaging optical system;
a fixed part facing the movable part;
one first coil that is provided on one of the movable part and the fixed part and generates a driving force in a first direction perpendicular to the optical axis of the imaging optical system when energized;
a second coil that is provided on one of the movable part and the fixed part and generates a driving force in a second direction perpendicular to the optical axis of the imaging optical system and the first direction;
a first magnet provided on the other of the movable part and the fixed part and disposed at a position facing the first coil;
a second magnet provided on the other of the movable part and the fixed part and located at a position facing the second coil;
a third magnet provided on the other of the movable part and the fixed part and magnetized in a direction parallel to the optical axis of the imaging optical system;
position detection means for detecting the position of the movable part with respect to the fixed part,
The position detection means is configured to detect the output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the third magnet; The position of the movable part in the first direction with respect to the fixed part is detected based on a first magnet and the output of a magnetic detection sensor disposed at a position facing the first magnet, and one of the movable part and the fixed part is detected. an output of a magnetic detection sensor provided at a position facing the third magnet; and a magnetic detection sensor provided at one of the movable part and the fixed part and located at a position facing the second magnet. The imaging device is characterized in that the position of the movable part in the second direction with respect to the fixed part is detected based on the output of the fixed part . The position detection means includes:
An output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the third magnet; and an output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged opposite to the first magnet. Detecting the position of the movable part in the first direction with respect to the fixed part based on the sum and difference of outputs of magnetic detection sensors arranged at positions,
An output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the third magnet; and an output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged opposite to the second magnet. The imaging device according to claim 10, wherein the position of the movable part in the second direction with respect to the fixed part is detected based on the sum and difference of outputs of magnetic detection sensors arranged at positions where . The position detection means is configured to detect the output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the third magnet; of the magnetic detection sensor provided in one of the movable part and the fixed part and arranged in the position facing the third magnet, relative to the sum of the outputs of the magnetic detection sensors arranged in the position facing the first magnet. Based on the ratio of the difference between the output and the output of a magnetic detection sensor provided in one of the movable part and the fixed part and disposed at a position facing the first magnet, the first magnet of the movable part relative to the fixed part is The imaging device according to claim 11, wherein the imaging device detects a position in one direction. 2. The movable portion according to claim 1, further comprising a control means for controlling energization of at least one of the first coil and the second coil to control the position of the movable part based on the detection result of the position detection means. 13. The imaging device according to 11 or 12. When the image stabilization function performed by moving the movable part is OFF, the control means includes a magnetic detection device provided in one of the movable part and the fixed part and arranged at a position facing the third magnet. Controlling the energization of the first coil based on the output of the sensor and the output of a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the first magnet. The imaging device according to claim 13, wherein the position of the movable part is controlled. An image sensor and
a movable part that holds one of the imaging element and the imaging optical system;
a fixed part facing the movable part;
one first coil that is provided on one of the movable part and the fixed part and generates a driving force in a first direction perpendicular to the optical axis of the imaging optical system when energized;
a second coil that is provided on one of the movable part and the fixed part and generates a driving force in a second direction perpendicular to the optical axis of the imaging optical system and the first direction;
a first magnet provided on the other of the movable part and the fixed part and disposed at a position facing the first coil;
a second magnet provided on the other of the movable part and the fixed part and located at a position facing the second coil;
a magnetic detection sensor provided on one of the movable part and the fixed part and arranged at a position facing the first magnet;
position detection means for detecting the position of the movable part with respect to the fixed part,
The magnetic detection sensor has two magnetically sensitive parts arranged in the first direction,
The imaging device is characterized in that the position detection means detects the position of the movable part in the first direction with respect to the fixed part based on outputs of two magnetic sensing parts of the magnetic detection sensor. The position detection means detects the position of the movable part in the first direction with respect to the fixed part based on the sum and difference of outputs of two magnetically sensitive parts of the magnetic detection sensor. 16. The imaging device according to item 15. The position detecting means is configured to determine the position of the movable part relative to the fixed part based on the ratio of the difference between the outputs of the two magnetically sensitive parts of the magnetically detecting sensor to the sum of the outputs of the two magnetically sensitive parts of the magnetically detecting sensor. The imaging device according to claim 16, wherein the imaging device detects a position in the first direction. 2. The movable portion according to claim 1, further comprising a control means for controlling energization of at least one of the first coil and the second coil to control the position of the movable part based on the detection result of the position detection means. 18. The imaging device according to any one of 15 to 17. The control means is configured to control the position of the movable part detected by the position detection means based on the outputs of the two magnetically sensitive parts of the magnetic detection sensor when the image stabilization function performed by moving the movable part is OFF. The imaging device according to claim 18, wherein the position of the movable part is controlled by controlling energization of the first coil based on the position in the first direction.

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