Imaging device and actuator driver

Abstract

To provide an imaging device capable of high-precision image stabilization. [Solution] The imaging device 300 includes an image sensor 302, a shake detection element that generates a yaw shake detection signal, a pitch shake detection signal, and a roll shake detection signal indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor 302, an actuator configured to independently displace the image sensor 302 in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, and a control device that drives the actuator in accordance with the yaw shake detection signal, the pitch shake detection signal, and the roll shake detection signal. The control device corrects the roll shake detection signal so as to reduce the influence on rotation around the third drive axis that occurs when the image sensor 302 is displaced in at least one of the directions of the first drive axis and the second drive axis.

Description

[Technical Field]

[0001] This disclosure relates to an imaging device and an actuator driver. [Background technology]

[0002] In recent years, camera modules installed in smartphones and other devices have increasingly incorporated features that detect the position of the imaging lens and feed back this positional information to control the lens's position with high precision and speed. In particular, incorporating feedback control as optical image stabilization (OIS) enables highly accurate image stabilization.

[0003] Camera shake can be categorized into three types: pitch, yaw, and roll. Typically, pitch shake refers to shake around one axis perpendicular to the optical axis (pitch axis, X-axis), yaw shake refers to shake around another axis perpendicular to the optical axis (yaw axis, Y-axis), and roll shake refers to rotational shake around the optical axis (Z-axis). The amount of each type of shake is detected as an angular velocity signal by a gyro sensor, and the amount of angular shake is calculated by integrating these signals.

[0004] In this specification, the direction of rotation around the yaw axis is referred to as the yaw direction, the direction of rotation around the pitch axis is referred to as the pitch direction, and the direction of rotation around the roll axis is referred to as the roll direction. As an optical image stabilization (OIS), a method of correcting camera shake by displacing the image sensor (sensor shift method) has been proposed. Specifically, a technique is known in which the image sensor is shifted in the Y-axis direction for pitch shake, shifted in the X-axis direction for yaw shake, and rotated around the Z-axis for roll shake to optically correct the shake.

[0005] When roll shake correction is performed, the image sensor rotates as a result of the correction, causing an offset in the position detection signals in the X-axis and Y-axis directions, or a change in the direction of the driving force in the X-axis and Y-axis directions, resulting in a misalignment with the pitch axis and yaw axis of the gyro sensor. Patent Document 1 describes a technique for correcting the shake detection signal of a shake detection element based on the change in the direction of the driving force, even when the direction of the driving force in the pitch direction and yaw direction and the shake detection direction are misaligned due to the rotation of the image sensor caused by roll shake correction. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-28340

[0007] The inventors have come to realize that even when at least one of pitch blur and yaw blur is corrected, the image sensor moves in the XY plane as a result of the correction, which can change the sensitivity of the position detection signal around the Z axis, potentially reducing the accuracy of image stabilization.

[0008] [overview] This disclosure has been made in view of the circumstances, and one exemplary objective of a certain aspect thereof is to provide an imaging device capable of high-precision image stabilization.

[0009] One aspect of this disclosure is an imaging device. The imaging device includes an image sensor, a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, and a control device that drives the actuator in accordance with the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The control device corrects the roll shake detection signal so as to reduce the influence on rotation around the third drive axis that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

[0010] Another aspect of this disclosure is also an imaging device. The imaging device includes an image sensor; a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor; an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate the image sensor around a third drive axis which should be parallel to the roll axis; a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis; and a control device that drives the actuator in accordance with the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The control device corrects the position detection signal so as to reduce the change in the sensitivity of the position detection signal of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

[0011] A further aspect of this disclosure is an actuator driver used in an imaging device. The imaging device includes an image sensor; a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor; an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis; and an actuator driver that drives the actuator in response to the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The actuator driver includes a correction unit that corrects the roll shake detection signal so as to reduce the influence on rotation around the third drive axis caused by displacing the image sensor in at least one of the directions of the first drive axis and the second drive axis, and a drive unit that drives the actuator based on the corrected roll shake detection signal.

[0012] Another aspect of this disclosure is also an actuator driver used in an imaging device. The imaging device includes an image sensor; a shake detection element that generates a yaw shake detection signal, a pitch shake detection signal, and a roll shake detection signal indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor; an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis; and a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The actuator driver includes a correction unit that corrects the third position information so as to reduce the change in the position detection signal sensitivity of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis, and a drive unit that drives the actuator based on the corrected third position information.

[0013] Furthermore, any combination of the above components, or any substitution of components or expressions between methods, apparatus, systems, etc., are also valid as embodiments of the present invention or this disclosure. Moreover, the description in this section does not describe all the indispensable features of the present invention, and therefore, subcombinations of these described features may also constitute the present invention. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows an imaging device. [Figure 2] Figures 2(a) and 2(b) illustrate the driving and position detection of the image sensor in the first embodiment. [Figure 3] Figure 3 shows the state in which the image sensor has been displaced for pitch blur correction. [Figure 4] Figure 4 shows the state after the image sensor has been rotated from the state shown in Figure 3. [Figure 5] Figure 5 schematically shows the relationship between the rotation angle of the image sensor in the roll direction, corresponding to the displacement of the image sensor in the second drive axis direction, and the intensity of the position detection signal related to the amount of rotation. [Figure 6] Figure 6 is a block diagram of a first specific example of an actuator control device. [Figure 7] Figure 7 is a block diagram of a second specific example of an actuator control device. [Figure 8] Figure 8 is a block diagram of a third specific example of an actuator control device. [Figure 9] Figure 9 is a block diagram of a fourth specific example of an actuator control device. [Figure 10] Figures 10(a) and 10(b) are diagrams illustrating the main components for driving and position detection of the image sensor in the second embodiment. [Figure 11] Figure 11 is a block diagram of a fifth specific example of an actuator control device. [Figure 12] Figure 12 is a schematic diagram illustrating the misalignment between the drive axis and the gyro detection axis. [Figure 13] Figure 13 is a block diagram of a sixth specific example of an actuator control device.

[0015] [Detailed explanation] (Summary of the embodiment) This section outlines some exemplary embodiments of the present disclosure. This outline is intended to provide a basic understanding of the embodiments and to simplify some concepts of one or more embodiments, serving as a prelude to the more detailed descriptions that follow. It is not intended to limit the scope of the invention or disclosure. This outline is not a comprehensive overview of all possible embodiments, nor is it intended to identify essential elements of all embodiments or to delineate the scope of some or all aspects. For convenience, “one embodiment” may be used to refer to one or more embodiments (examples or variations) disclosed herein.

[0016] An imaging device according to one embodiment includes an image sensor, a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, and a control device that drives the actuator in accordance with the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The control device corrects the roll shake detection signal so as to reduce the influence on rotation around the third drive axis that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

[0017] With this configuration, even when the image sensor is displaced to correct at least one of yaw shake and pitch shake, the influence on rotation around the third drive axis can be reduced by correcting the roll shake detection signal, thus enabling highly accurate image stabilization.

[0018] In one embodiment, the control device may calculate a correction displacement for at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and may set the correction amount for the roll shake detection signal based on the correction displacement. In this case, since it is possible to set how much the roll shake detection signal should be corrected based on at least one of the yaw shake detection signal and the pitch shake detection signal, more accurate image stabilization becomes possible.

[0019] In one embodiment, the system may further include a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The control device may calculate the displacement of the image sensor in the direction of the first drive axis or the second drive axis based on the position detection signal and set the correction amount of the roll shake detection signal based on the displacement. In this case, the amount by which the roll shake detection signal should be corrected can be set based on the calculated displacement in the direction of the first drive axis or the second drive axis, enabling more accurate image stabilization.

[0020] An imaging device according to one embodiment includes an image sensor, a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis, and a control device that drives the actuator in accordance with the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The control device corrects the position detection signal so as to reduce the change in the sensitivity of the position detection signal of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

[0021] With this configuration, even when the image sensor is displaced to correct at least one of yaw shake and pitch shake, the change in sensitivity of the position detection signal of the third position information can be reduced by correcting the position detection signal, thus enabling highly accurate image stabilization.

[0022] In one embodiment, the control device may calculate a correction displacement for at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and may set the correction amount for the sensitivity of the position detection signal of the third position information based on the correction displacement. In this case, since it is possible to set how much the sensitivity of the position detection signal of the third position information should be corrected based on at least one of the yaw shake detection signal and the pitch shake detection signal, more accurate image stabilization becomes possible.

[0023] In one embodiment, the control device may calculate the yaw displacement of the image sensor based on the first position information, or the pitch displacement of the image sensor based on the second position information, and may set the correction amount for the position detection signal sensitivity of the third position information based on the yaw displacement or the pitch displacement. In this case, since it is possible to set how much the sensitivity of the position detection signal of the third position information should be corrected based on the calculated yaw displacement or pitch displacement, more accurate image stabilization becomes possible.

[0024] An actuator driver according to one embodiment is used in an imaging device. The imaging device includes an image sensor, a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, and an actuator driver that drives the actuator in accordance with the yaw shake detection signals, pitch shake detection signals, and roll shake detection signals. The actuator driver includes a correction unit that corrects the roll shake detection signal so as to reduce the influence on rotation around the third drive axis caused by displacing the image sensor in at least one of the directions of the first drive axis and the second drive axis, and a drive unit that drives the actuator based on the corrected roll shake detection signal.

[0025] With this configuration, even when the image sensor is displaced to correct at least one of yaw shake and pitch shake, the influence on rotation around the third drive axis can be reduced by correcting the roll shake detection signal, thus enabling highly accurate image stabilization.

[0026] In one embodiment, the correction unit may calculate a correction displacement for at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, or it may set the correction amount for the roll shake detection signal based on the correction displacement. In this case, since it is possible to set how much the roll shake detection signal should be corrected based on at least one of the yaw shake detection signal and the pitch shake detection signal, more accurate image stabilization becomes possible.

[0027] In one embodiment, the imaging device may further include a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The correction unit may calculate the displacement of the image sensor in the direction of the first drive axis based on the first position information, or the displacement of the image sensor in the direction of the second drive axis based on the second position information, and set the correction amount of the roll shake detection signal based on the calculated displacement. In this case, since it is possible to set how much the roll shake detection signal should be corrected based on the calculated displacement in the direction of the first drive axis or the displacement in the direction of the second drive axis, more accurate image stabilization becomes possible.

[0028] An actuator driver according to one embodiment is used in an imaging device. The imaging device includes an image sensor, a shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals indicating shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, an actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis and in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, and a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The actuator driver includes a correction unit that corrects the third position information so as to reduce the change in the sensitivity of the position detection signal of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis, and a drive unit that drives the actuator based on the corrected third position information.

[0029] With this configuration, even when the image sensor is displaced to correct at least one of yaw shake and pitch shake, the change in the sensitivity of the position detection signal of the third position information can be reduced by correcting the third position information, thus enabling highly accurate image stabilization.

[0030] In one embodiment, the correction unit may calculate a correction displacement for at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and may set the correction amount for the position detection signal sensitivity of the third position information based on the correction displacement. In this case, since it is possible to set how much the sensitivity of the position detection signal of the third position information should be corrected based on at least one of the yaw shake detection signal and the pitch shake detection signal, more accurate image stabilization becomes possible.

[0031] In one embodiment, the correction unit may calculate the yaw displacement of the image sensor based on the first position information, or the pitch displacement of the image sensor based on the second position information, and may set the correction amount for the position detection signal sensitivity of the third position information based on the yaw displacement or the pitch displacement. In this case, since it is possible to set how much the sensitivity of the position detection signal of the third position information should be corrected based on the calculated yaw displacement or pitch displacement, more accurate image stabilization becomes possible.

[0032] In one embodiment, the yaw shake detection signal and the pitch shake detection signal may be corrected for each other based on the directional misalignment between the pitch axis and the first drive axis, or between the yaw axis and the second drive axis. In this case, more accurate image stabilization becomes possible.

[0033] In one embodiment, in order to reduce the effect of offsets in at least one of the first position information and the second position information caused by rotation around the third drive shaft, at least one of the first position information, the second position information, the yaw shake detection signal, and the pitch shake detection signal may be corrected. In this case, more accurate image stabilization becomes possible.

[0034] (Embodiment) Preferred embodiments will be described below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant descriptions will be omitted as appropriate. Furthermore, the embodiments are illustrative and not limiting to the disclosure and invention, and not all features or combinations thereof described in the embodiments are necessarily essential to the disclosure and invention.

[0035] Furthermore, the dimensions (thickness, length, width, etc.) of each component shown in the drawing may be enlarged or reduced as appropriate for ease of understanding. Moreover, the dimensions of multiple components do not necessarily represent their relative sizes; even if component A is depicted as thicker than component B in the drawing, component A may actually be thinner than component B.

[0036] In this specification, "member A connected to member B" includes cases where member A and member B are physically and directly connected, as well as cases where member A and member B are indirectly connected via other members that do not substantially affect their electrical connection or impair the functions or effects produced by their connection.

[0037] Similarly, "the state in which member C is provided between member A and member B" includes not only cases where member A and member C, or member B and member C, are directly connected, but also cases where they are indirectly connected via other members that do not substantially affect their electrical connection state or impair the functions or effects produced by their combination.

[0038] First, let's explain the configuration of the imaging device. Figure 1 shows the imaging device 300. The imaging device 300 is a camera module built into digital cameras, digital video cameras, smartphones, tablet devices, drones, etc. This imaging device 300 is equipped with an AF (Auto Focus) function and an image stabilization function that corresponds to pitch, yaw, and roll. For convenience, the optical axis is taken as the Z axis, one axis perpendicular to the Z axis is taken as the X axis, and another axis perpendicular to the Z axis is taken as the Y axis. The Z axis is called the roll axis, rotational shake around the Z axis is called roll shake, rotational shake around the X axis is called pitch shake, and rotational shake around the Y axis is called yaw shake.

[0039] Image stabilization methods are divided into lens shift methods, which displace the lens, and sensor shift methods, which displace the image sensor. The imaging device 300 in Figure 1 employs the latter method. The imaging device 300 comprises an image sensor 302, a lens 304, a processor 306, a gyro sensor 308, an AF actuator 402, an OIS actuator 404, a position detector 406, and an actuator control device 400 as an actuator driver.

[0040] The lens 304 is positioned on the optical axis of the light incident on the image sensor 302. The actuator control device 400 receives the AF position command value (also called the target code) P from the processor 306. REF_AF Based on this, the AF actuator 402 is driven to position the lens 304 in the direction of the optical axis (Z axis).

[0041] In AF operation, the processor 306 adjusts the position command value P so that the contrast of the image captured by the image sensor 302 is increased. REF_AF It generates (contrast AF). Alternatively, based on the output from an AF sensor located outside the image sensor 302 or embedded in the image sensor surface, it generates a position command value P REF_AF A phase-difference autofocus (AF) may be generated.

[0042] The AF actuator 402 is configured to position the lens 304 in the optical axis direction (Z axis direction) in relation to autofocus (AF). The AF actuator 402 is, for example, a voice coil motor. The lens 304 is mounted on a lens holder 310 and supported to move in the Z axis direction. An AF coil 312 is wound around the lens holder 310, and an AF permanent magnet 314 is positioned in a fixed part opposite the AF coil 312. Although not shown in the figures, an AF yoke may be provided in contact with the AF permanent magnet. By energizing the AF coil 312, the lens 304 and lens holder 310 are driven together in the Z axis direction by magnetic interaction with the AF permanent magnet 314. In other words, the combination of the AF coil 312 and the AF permanent magnet 314 corresponds to the AF actuator 402. A position detector may also be provided in the AF actuator, and feedback control may be applied to the AF as well.

[0043] The OIS actuator 404 displaces the image sensor 302 in the direction of the first drive axis, which should be parallel to the pitch axis (X axis), to correct yaw shake, and displaces the image sensor 302 in the direction of the second drive axis, which should be parallel to the yaw axis (Y axis), to correct pitch shake. In addition, the OIS actuator 404 is configured to rotate the image sensor 302 around the third drive axis, which should be parallel to the roll axis (Z axis), to correct roll shake. The first drive axis, second drive axis, and third drive axis will also be referred to as the x axis, y axis, and z axis, respectively, and will be collectively referred to as the drive axes.

[0044] The OIS actuator 404 is also a voice coil motor, and it displaces the image sensor 302 together with the substrate 316 on which it is mounted. An OIS coil 318 and a position detection element 320 are fixed to the side of the substrate 316 opposite to the side on which the image sensor 302 is mounted. An OIS permanent magnet 322 and an OIS yoke 324 are fixed opposite the OIS coil 318 and the position detection element 320. The combination of the OIS coil 318 and the OIS permanent magnet 322 corresponds to the OIS actuator 404. In this example, there are four combinations of OIS coils 318 and OIS permanent magnets 322, and by applying current independently to each OIS coil 318, driving force for shake correction in three directions is obtained: in the direction of the first drive axis (x axis), in the direction of the second drive axis (y axis), and around the third drive axis (z axis) (roll direction).

[0045] The gyro sensor 308 is a shake detection element and displays a yaw shake detection signal G that indicates shake around the yaw axis, pitch axis, and roll axis acting on the image sensor 302. Y Pitch drift detection signal G P Roll shake detection signal G R It generates the yaw axis (Y-axis), pitch axis (X-axis), and roll axis (Z-axis), which are collectively referred to as gyro detection axes.

[0046] The position detector 406 receives a position detection signal P that indicates the state of the image sensor 302. FB_OIS This generates the position detection signal P. FB_OISis the first position information P regarding the position of the imaging element 302 in the first drive axis direction (x-axis). FB_X and the second position information P regarding the position of the imaging element 302 in the second drive axis direction (y-axis). FB_Y is included. Further, the position detection signal P FB_OIS may also include the third position information P regarding the rotation amount of the imaging element 302 around the third drive axis (z-axis). FB_R

[0047] The position detector 406 is composed of a combination of the position detection element 320 and the OIS permanent magnet 322. As the position detection element 320, magnetic detection means such as a Hall element are often used, and here it is assumed to be a Hall element. In this example, there are three position detection elements 320, and based on the position detection signal P FB_OIS , the displacement amount of the imaging element 302 (respectively, the first position detection value P FB_X , the second position detection value P FB_Y , the third position detection value P FB_R ) is obtained. The position detection element 320 generates an electrical signal (that is, the position detection signal P FB ) corresponding to the current position of the imaging element 302. This position detection signal P FB is fed back to the actuator control device 400.

[0048] The actuator control device 400 generates position command values (target codes) P Y , G P , G R based on the shake detection signals G REF_X , P REF_Y , P REF_R (these command values are collectively referred to as the OIS position command value P REF_OIS ), drives the OIS actuator 404 based on the OIS position command value P REF_OIS , and positions the imaging element 302 in a plane perpendicular to the optical axis.

[0049] The driving of the OIS actuator 404 may be performed in a closed loop (feedback control). For OIS, the output (shake detection signal) G from the gyro sensor 308​P ,G Y ,G R The OIS position command value P is input to the actuator control device 400, and the actuator control device 400 uses these signals to determine the OIS position command value P REF_OIS Generates the pitch deviation detection signal G. P This represents the angular velocity around the pitch axis (X axis), and the yaw ripple detection signal G Y This represents the angular velocity around the yaw axis (Y axis), and the roll wobble detection signal G R This represents the angular velocity around the roll axis (Z axis).

[0050] To counteract the yaw axis shake, the OIS actuator 404 displaces the image sensor 302 in the direction of the first drive axis (x axis) along the first drive axis. To counteract the pitch axis shake, the OIS actuator 404 displaces the image sensor 302 in the direction of the second drive axis (y axis) along the second drive axis. To counteract the roll shake, the OIS actuator 404 drives and tilts the image sensor 302 around the third drive axis (optical axis of the lens 304, z axis).

[0051] The actuator control device 400 receives the feedback position detection signal P FB_OIS Location information P obtained from FB_X , P FB_Y and P FB_R Each of them is a position command value P REF_X , P REF_Y and P REF_R The OIS actuator 404 is feedback controlled to match this. However, due to the effects of crosstalk, etc., described later, the position detection signal P FB Yes, position command value P REF_OIS If corrections are necessary, these should be corrected before applying feedback control.

[0052] By detecting the position of the image sensor 302 in this way and using the detected position as feedback for position control, transient vibrations in the step response can be suppressed to speed up convergence, and the positioning accuracy to the target position can be improved.

[0053] Next, we will explain crosstalk. As described above, in a structure in which the image sensor 302 is driven with three degrees of freedom around the first drive axis, the second drive axis, and the third drive axis to correct blur, when the image sensor 302 is displaced in one direction, problems may arise such as (i) the position information corresponding to the other direction changes, or (ii) a discrepancy occurs between the direction of blur detection and the direction of the driving force. In particular, when the image sensor 302 is displaced in the direction of the second drive axis, the third position information P corresponding to the third drive axis changes. FB_R This changes. In this specification, this is referred to as crosstalk. The actuator control device 400 corrects these crosstalk components and corrects the vibration detection signal in accordance with the direction of the driving force.

[0054] In the following, crosstalk compensation will be described with reference to the first and second embodiments.

[0055] <First Embodiment> The first embodiment will be described with reference to Figures 2 to 9.

[0056] Figures 2(a) and 2(b) illustrate the driving and position detection of the image sensor in the first embodiment. Figure 2(a) shows a plan view from the optical axis direction, and Figure 2(b) shows a cross-sectional view taken along the arrow AA in Figure 2(a).

[0057] In the diagram, the x-direction represents the first drive axis direction for yaw shake correction, and the y-direction represents the second drive axis direction for pitch shake correction. For roll shake correction, the image sensor 2 is rotated around the z-direction of its center position as the axis. The X-axis represents the pitch axis, the Y-axis represents the yaw axis, and the Z-axis represents the roll axis. When the rotation angle of the image sensor 2 in the roll direction is zero, the x-axis and the X-axis are parallel, and the y-axis and the Y-axis are parallel.

[0058] The drive coils (referred to as X coils) 4 and 6 for the first drive axis direction (x axis direction) are arranged on both sides of the image sensor 2. A Hall element (referred to as an X-hole) 8 for detecting the displacement of the image sensor 2 in the first drive axis direction is arranged within the winding of one of the X coils 4. From the output of the X-hole 8, the first position detection value P is obtained. FB_X This can be obtained. On the other hand, the drive coils (referred to as Y coils) 10 and 12 for the second drive axis direction (y axis direction) are arranged side by side on one side of the image sensor 2. Hall elements (referred to as Y holes) 14 and 16 for detecting the displacement of the image sensor 2 in the second drive axis direction are arranged in the windings of both Y coils 10 and 12. The image sensor 2, X coils 4 and 6, X hole 8, Y coils 10 and 12, and Y holes 14 and 16 form an OIS movable part 18, and the OIS movable part 18 displaces in the y and x directions and rotates around the optical axis as a whole.

[0059] Opposite the X coils 4 and 6 are permanent magnets (referred to as X permanent magnets) 20 and 22, which are used for driving and position detection to correct yaw wobble. Furthermore, opposite the Y coils 10 and 12 and the Y Hall elements 14 and 16 are permanent magnets (referred to as Y permanent magnets) 24 and 26, which are used for driving and position detection to correct pitch wobble. In addition, a yoke 28 is provided on the back of each permanent magnet to reduce magnetic flux leakage and increase the magnetic flux density acting on the coils and Hall elements. These permanent magnets and yokes are positioned in fixed parts that do not move for wobble correction.

[0060] The Y coils 10 and 12, Y holes 14 and 16, and Y permanent magnets 24 and 26 also serve as means for driving and detecting the position for roll wobble correction. Specifically, current can be applied independently to the left and right Y coils 10 and 12. The sum of the forces from the left and right driving means (in-phase component) provides a driving force in the second driving axis direction (y-axis direction) for pitch wobble correction, and the difference in forces from the left and right driving means (differential component) generates torque, providing a rotational force around the z-axis for roll wobble correction. Similarly, the displacement of the OIS movable part 18 at each position is detected from the output of the left and right Y holes 14 and 16. The second position detection value P is obtained from the average (or in-phase component) of the two.FB_Y This allows us to obtain the third position detection value P from the difference (or differential component) between the two. FB_R You can obtain this.

[0061] Next, referring to Figure 3, the positional relationships of the coil, Hall element, permanent magnet, etc., when the image sensor 2 is displaced to correct pitch blur will be explained. Figure 3 shows the state when the image sensor 2 is displaced to correct pitch blur. Figure 3 shows a plan view from the optical axis direction.

[0062] As shown in Figure 3, when the OIS movable part 18 is displaced in the second drive axis direction (negative y-axis direction in Figure 3) for pitch wobble correction, the positional relationship between the coil, Hall element and permanent magnet changes.

[0063] As shown in Figure 3, the displacement of the OIS movable part 18 causes the positions of the Y-holes 14 and 16 to shift in the direction of the second drive axis from the positions of the polarization lines 24a and 26a of the permanent magnets 24 and 26. In this specification, a hypothetical line that divides a permanent magnet into N and S in its center is referred to as a polarization line. The Y-holes 14 and 16 are normally positioned such that the detected magnetic flux density is zero when the displacement of the OIS movable part 18 is zero. Therefore, in the state shown in Figure 3, the intensity of the signals detected by the Y-holes 14 and 16 increases or decreases in the same way.

[0064] Figure 4 shows the state after the image sensor 2 has rotated further for roll blur correction from the state shown in Figure 3. Figure 4 is a plan view from the optical axis direction. When the image sensor 2 rotates around the third drive axis (z axis) from the state shown in Figure 2, the Y-hole 14 is displaced by Δy in the Y-axis direction from the polarization line 24a of the permanent magnet 24, and the Y-hole 16 is displaced by -Δy in the Y-axis direction from the polarization line 26a of the permanent magnet 26. In other words, when the image sensor 2 rotates around the z axis from a state that is not shifted in the second drive axis direction, the increase in magnetic flux density detected by one of the Y-holes 14 and 16 is approximately equal to the decrease in magnetic flux density detected by the other. On the other hand, in the state shown in Figure 4, since the image sensor 2 rotates from a state that is shifted in the second drive axis direction, the increase in magnetic flux density detected by one of the Y-holes 14 and 16 is different to the decrease in magnetic flux density detected by the other. In this way, the sensitivity of the position detection signal related to the amount of rotation of the image sensor 2 around the z axis changes. The reason this occurs is that the position detection characteristics, which show the relationship between the detected value of magnetic flux density and the amount of displacement in the direction of the second drive axis, are not perfectly linear. That is, the tilt is maximum at the center position on the polarization lines 24a and 26a of the permanent magnets 24 and 26, and the tilt decreases quadratically as the sensor shifts in the direction of the second drive axis from there. Therefore, when the image sensor 2 rotates around the third drive axis (z axis) while shifted in the direction of the second drive axis (y axis), one of the Y-holes 14 and 16 is displaced to the side where sensitivity decreases, and the other is displaced to the side where sensitivity recovers, and this difference causes crosstalk. In this way, the sensitivity of the position detection signal with respect to the amount of rotation of the image sensor 2 around the z axis changes. This is the crosstalk that is the subject of this specification.

[0065] Figure 5 schematically shows the relationship between the rotation angle of the image sensor 2 in the roll direction and the intensity of the position detection signal related to the amount of rotation, depending on the amount of displacement of the image sensor 2 in the second drive axis direction. As shown in Figure 5, the larger the amount of displacement of the image sensor 2 in the second drive axis direction, the smaller the change in signal intensity in response to the change in the rotation angle of the image sensor 2 in the roll direction. In other words, the larger the amount of displacement of the image sensor 2 in the second drive axis direction, the lower the sensitivity of the position detection signal related to the amount of rotation of the image sensor 2 around the z axis. To explain in more detail, the degree of decrease in the sensitivity of the position detection signal with respect to the amount of displacement in the second drive axis direction becomes more pronounced as the amount of displacement increases, showing a quadratic change.

[0066] These crosstalks degrade the accuracy of roll wobble correction, so correction is desirable. In crosstalk correction, a correction displacement for at least one of the yaw wobble and pitch wobble is calculated based on at least one of the yaw wobble detection signal and the pitch wobble detection signal. Then, the correction amount for the roll wobble detection signal is set based on the calculated correction displacement. An example of crosstalk correction is described below.

[0067] In the first example of crosstalk correction, a polynomial is used, with the displacement (offset) in the second drive axis direction for pitch wobble correction as the variable, to calculate the correction coefficient for the sensitivity of the position detection signal with respect to the amount of rotation around the z axis (detection sensitivity). The intensity distribution of the magnetic flux density used for the position detection signal with respect to the amount of rotation around the z axis can be approximated by, for example, a quadratic function. Let the offset be x and the detection sensitivity before correction be y. y=ax 2 +bx+c ···(1) This can be expressed as follows. The image sensor 2 is positioned such that the perpendicular magnetic flux density is zero when the offset is zero. Therefore, by substituting 0 for x and the detection sensitivity y0 at that time for y, we obtain c=y0. Also, since the peak of the quadratic function occurs when the offset is zero, b=0, and we obtain the following equation (2). y=ax 2 +y0···(2) Here, by substituting any non-zero offset x1 into x and the corresponding detection sensitivity y1 into y, a can be calculated as follows. a = (y1 - y0) / x1 2 (3) In other words, the following equation (4) is obtained. y=(y1-y0) / x1 2 x 2 +y0···(4) This allows us to calculate the correction coefficient for each offset, using the detection sensitivity y0 when offset x is zero as a reference. Note that this example is not limited to fitting using polynomials. For example, a table that associates displacement amounts with correction coefficients may be used, or polynomial fitting may be used in combination with a table.

[0068] In the second example of crosstalk correction, the second position detection value P FB_Y The correction coefficient used in the correction is used to set the correction amount of the position detection signal related to the amount of rotation around the z axis. As described above, in this embodiment, the output of the left and right Y holes 14 and 16 is used to obtain the second position detection value P from the average (or in-phase component) of the two. FB_Y This allows us to obtain the third position detection value P from the difference (or differential component) between the two. FB_R This can be obtained. That is, the second position detection value P FB_Y and the third position detection value P FB_R This is obtained by sharing the same magnetic field. Therefore, the second position detection value P associated with the displacement in the second drive axis direction for pitch wobble correction FB_Y Using the correction coefficient derived to compensate for the nonlinearity, the third position detection value P FB_R This can also be corrected with near accuracy. In this example as well, as in the first example, the correction coefficient may be derived by fitting using a polynomial, or it may be derived using a table that associates displacement amounts with correction coefficients, or it may be derived by using a combination of fitting using a polynomial and a table.

[0069] In the third example of crosstalk correction, the nonlinearity of the output signals from the left and right Y-holes 14 and 16 is corrected, and the corrected signals are combined to obtain a position detection signal relating to the corrected amount of rotation around the z-axis. In this example as well, as in the first example, the correction coefficient may be derived by fitting using a polynomial, or by using a table that associates displacement amounts with correction coefficients, or by using a combination of fitting using a polynomial and a table to derive the correction coefficient.

[0070] In the first to third examples of crosstalk correction described above, the correction of the position detection signal was explained. Using a similar method, the roll wobble detection signal G from the gyro sensor 308 is corrected so that the influence of displacement in the direction of the second drive axis on rotation around the third drive axis (z axis) is reduced. R It can be corrected.

[0071] Next, the configuration of the actuator control device 400 will be explained with reference to the block diagrams in Figures 6 to 9. Figure 6 is a block diagram of a first specific example of the actuator control device 400. Note that the parts related to AF are omitted in Figures 6 to 9.

[0072] The actuator control device 400 is an actuator driver, and is, for example, a functional IC (Integrated Circuit) integrated on a single semiconductor substrate. Here, "integration" includes cases where all the circuit components are formed on the semiconductor substrate, or where the main components of the circuit are integrated as a single unit, and some resistors, capacitors, etc., may be provided outside the semiconductor substrate for adjusting circuit constants. By integrating the circuit onto a single chip, the circuit area can be reduced and the characteristics of the circuit elements can be kept uniform.

[0073] Interface circuits 510, 512, and 514 receive digital angular velocity signals from yaw, pitch, and roll gyro sensors 330, 332, and 334, respectively. For example, interface circuits 510, 512, and 514 may be SPI (Serial Peripheral Interface). Gyro DSPs (Digital Signal Processors) 520, 522, and 524 receive shake detection signals G corresponding to each direction based on the angular velocity signals received by interface circuits 510, 512, and 514. Y , G P , G R Outputs.

[0074] DSP536 is G P and G R Based on this, the target signal P around the third drive shaft REF-R The following is calculated and output: In this embodiment, the driving means around the third drive axis and the driving means in the direction of the second drive axis (y axis) are shared, so the ratio of the driving force generated by the two Y coils 10 and 12 is calculated and output in the direction of the target signal P in the second drive axis direction (around the pitch axis). REF-P and the target signal P around the third drive shaft REF-R It is necessary to calculate this from P, and this calculation is performed by the DSP534. In other words, the DSP534 is P REF-R and P REF-P Based on this, P is defined as the amount of target displacement that should occur at the positions of the two Y-holes 14 and 16. REF-Y1 and P REF-Y2 This generates the P. The calculation formula can be derived from the geometry (geometric arrangement) of the OIS movable part 18 and the permanent magnets 20 and 22. REF-P G P It can be used as is.

[0075] The position detector 406 (see Figure 1) includes Hall elements 8, 14, and 16, and the Hall voltage V corresponds to the displacement of the position of each Hall element in the movable part. + ,V -is generated and supplied to the hall detection pins (HP, HN) of the actuator control device 400. The position detection units 540, 542, 544 are based on the hall voltages V + , V - to generate digital position detection values P FB-X , P FB-Y1 , P FB-Y2 indicating the position (displacement) of the movable part. The position detection units 540, 542, 544 include hall amplifiers 548, 550, 552 that amplify the hall voltages, and A / D converters 554, 556, 558 that convert the outputs of the hall amplifiers 548, 550, 552 into digital position detection values P FB .

[0076] Constant current circuits 560, 562, 564 are provided to operate the respective hall elements 8, 14, 16. The constant current circuits 560, 562, 564 supply a predetermined bias current I BIAS to the hall elements 8, 14, 16. This bias current I BIAS is a power supply signal necessary to operate the hall elements 8, 14, 16, and thus the constant current circuits 560, 562, 564 can be regarded as hall bias circuits. Note that the voltage V HB of the hall bias pin (HB) may be used to detect the temperature of the hall element and used for temperature compensation.

[0077] The controllers 570, 572, 574 receive the respective position command values P REF-X , P REF-Y1 , P REF-Y2 and the position detection values P FB-X , P FB-Y1 , P FB-Y2 . The controllers 570, 572, 574 control the command values S FB-X , P FB-Y1 , P FB-Y2 to be respectively equal to the position command values P REF-X , P REF-Y1 , P REF-Y2 , and the control command values S REF-X , S REF-Y1 , S REF-Y2This generates the control command value S if the OIS actuator 404 is a voice coil motor. REF-X S REF-Y1 S REF-Y2 P is the command value for the drive current to be supplied to the voice coil motor. Controllers 570, 572, and 574 include, for example, error detectors 576, 578, and 580 and PID (Proportional Integral Differential) controllers 582, 584, and 586. Error detectors 576, 578, and 580 detect the position value P FB-X , P FB-Y1 , P FB-Y2 and position command value P REF-X , P REF-Y1 , P REF-Y2 The difference (error) ΔP of each is generated. PID controllers 582, 584, and 586 use PID (proportional-integral-derivative) calculations to generate the control command value S REF-X S REF-Y1 S REF-Y2 This generates the following. Instead of PID controllers 582, 584, and 586, PI controllers may be used, or nonlinear control may be employed.

[0078] Driver units 590, 592, and 594 control the control command value S REF-X S REF-Y1 S REF-Y2 A corresponding drive current is supplied to the OIS actuator 404.

[0079] Figure 7 is a block diagram of a second specific example of the actuator control device 400. This example of the actuator control device 400 differs from the first specific example in that it includes DSP530 and DSP532 instead of DSP536. The configuration other than DSP530 and DSP532 is the same as in the first specific example, so its explanation is omitted.

[0080] DSP530 is G P Based on this, in order to correct the sensitivity of the position detection signal around the third drive shaft, the position detection signal of the Y-hole 14, which affects the sensitivity of the position detection signal around the third drive shaft, is corrected to P FB-Y1 It outputs G PBased on this, in order to correct the sensitivity of the position detection signal around the third drive shaft, the position detection signal of the Y-hole 16, which affects the sensitivity of the position detection signal around the third drive shaft, is corrected to P FB-Y2 Outputs.

[0081] Figure 8 is a block diagram of a third specific example of the actuator control device 400. The actuator control device 400 in this example differs from the first specific example in that it further includes the DSP 530 and DSP 532 from the second specific example. The functions of each component are as described in the first and second specific examples, so a further explanation is omitted.

[0082] Figure 9 is a block diagram of a fourth specific example of the actuator control device 400. This example of the actuator control device 400 differs from the first specific example in that it includes DSP531, DSP533, and DSP537 instead of DSP534. The configuration other than DSP531, DSP533, and DSP537 is the same as in the first specific example, so its explanation is omitted.

[0083] The DSP531 detects the position signals P of Y-holes 14 and 16. FB-Y1 , P FB-Y2 Based on this, the position detection signal P around the second drive axis and the third drive axis is generated. FB-P , P FB-R The DSP533 generates a control command value S based on the drive control signal in the second drive axis direction and the drive control signal around the third drive axis. REF-Y1 S REF-Y2 It generates G P Based on this, in order to correct the sensitivity of the position detection signal around the third drive shaft, P FB-R Correct P FB-ΔR Outputs.

[0084] The above configuration of the actuator control device is merely an example, and may be modified as appropriate depending on the structure of the actuator and the magnitude of crosstalk. For example, the actuator control device 400 receives a pitch direction deviation detection signal G PInstead of using this method, the sensitivity of the position detection signal around the third drive axis may be corrected based on the position detection signal.

[0085] <Second Embodiment> The second embodiment will be described using Figure 10. Figures 10(a) and (b) are main component diagrams illustrating the driving and position detection of the image sensor in the second embodiment. Figure 10(a) shows a plan view from the optical axis direction, and Figure 10(b) shows a cross-sectional view taken along the CC arrow in Figure 10(a).

[0086] The second embodiment differs from the first embodiment in the arrangement of the coils and permanent magnets for driving the OIS movable part 18. In the second embodiment, each coil is arranged on the side of the movable part, and the permanent magnets are arranged opposite to them. That is, in the first embodiment, the coils and permanent magnets arranged on the left and right of the image sensor in Figure 2 were the X coil and X permanent magnet for driving in the x-axis direction, whereas in the second embodiment, the coils and permanent magnets arranged on the left and right of the image sensor in Figure 10 are the Y coil and Y permanent magnet for driving in the second drive axis direction (y direction). Similarly, the coils and permanent magnets arranged below the image sensor also have different driving directions in the first and second embodiments.

[0087] Figure 10 shows an example of the positional relationship of components involved in OIS drive when the image sensor is not rotating in the roll direction. In the figure, the x-direction represents the first drive axis direction for yaw shake correction, and the y-direction represents the second drive axis direction for pitch shake correction. For roll shake correction, the image sensor 2 is rotated around the z-direction (third axis) of the center position of the image sensor 2 as the axis. The drive coils (referred to as X coils) 4 and 6 for the first drive axis direction (x-axis direction) are arranged side by side below the image sensor 2. A Hall element (referred to as an X-hole) 8 for detecting the displacement of the image sensor 2 in the x-direction is placed in the winding of one of the X coils 6. On the other hand, the drive coils (referred to as Y coils) 10 and 12 for the second drive axis direction (y-axis direction) are arranged on both sides of the image sensor 2. Hall elements (referred to as Y-holes) 14 and 16 for detecting the displacement of the image sensor 2 in the y-direction are placed in the windings of both Y coils 10 and 12. The image sensor 2, X coils 4 and 6, X hole 8, Y coils 10 and 12, and Y holes 14 and 16 form the OIS movable part 18.

[0088] Opposite the X coil 4 is a permanent magnet 20 for driving yaw wobble correction (referred to as the X permanent magnet), and opposite the X coil 6 and X hole 8 are permanent magnets 22 for driving yaw wobble correction and position detection (referred to as the X permanent magnet). Furthermore, opposite the Y coils 10 and 12 and the Y holes 14 and 16 are permanent magnets 24 and 26 for driving pitch wobble correction and position detection (referred to as the Y permanent magnets). In addition, a yoke 28 is provided on the back of each permanent magnet to reduce magnetic flux leakage and increase the magnetic flux density acting on the coils and Hall elements. These permanent magnets and yokes are positioned in fixed parts that do not move for wobble correction.

[0089] The Y coils 10 and 12, Y holes 14 and 16, and Y permanent magnets 24 and 26 also serve as means for driving and position detection for roll wobble correction. Specifically, current can be applied independently to the left and right Y coils 10 and 12. The sum of the forces from the left and right driving means (in-phase component) provides a driving force in the direction of the second drive axis for pitch wobble correction, and the difference in forces from the left and right driving means (differential component) generates torque, which provides a rotational force around the third drive axis for roll wobble correction.

[0090] Similarly, the left and right Y-holes 14 and 16 detect the displacement of the movable part at their respective positions. The average (or in-phase component) of the two indicates the amount of displacement for pitch wobble correction, and the difference (or differential component) between the two allows us to obtain the rotation angle around the third drive shaft.

[0091] In this second embodiment, as in the first embodiment, crosstalk occurs. The crosstalk correction is the same as in the first embodiment, so we will omit its explanation.

[0092] While the structure of the OIS actuator has been described in the first and second embodiments, it is not limited to these. In the first and second embodiments, the driving means for the first drive shaft and the third drive shaft are shared, and the position detection elements for the first drive shaft and the third drive shaft are shared. However, each of the first drive shaft, the second drive shaft, and the third drive shaft may be independently provided with its own driving means and position detection means. Alternatively, the driving means for the first drive shaft and the second drive shaft may be shared, and the position detection elements for the first drive shaft and the second drive shaft may also be shared.

[0093] <Third Embodiment> In the first and second embodiments, we described the correction of crosstalk in which roll wobble control is affected by yaw wobble and pitch wobble control. However, crosstalk may occur simultaneously between yaw wobble control and pitch wobble control. Crosstalk correction in such cases will be described in the third embodiment.

[0094] A third embodiment will be described with reference to Figure 11. Figure 11 is a block diagram of a fifth specific example of the actuator control device 400. The block diagram of Figure 11 differs from the block diagram of Figure 6 in that, in order to correct the crosstalk between yaw deviation and pitch deviation, G Y and G P The key feature is the provision of routes that cross each other.

[0095] In this embodiment, there is a discrepancy (crosstalk) between the drive axis (direction of the driving force by the magnet and coil) and the gyro detection axis (direction of hand shake detection by the gyro sensor). As can be seen from the explanation of the block diagram in Figure 6, the DSP536 is G P and G R Based on this, the position command value P around the third drive shaft REF-R Because it calculates and outputs G P G inside Y If crosstalk influenced by P exists, REF-R G will also be affected by this. Y and G P If crosstalk exists between them, it is desirable to correct for it beforehand. Y and G P By performing crosstalk correction between them, the G that serves as the basis for roll detection correction is P Because it can be calculated more accurately, the correction accuracy of roll detection also improves.

[0096] The crosstalk caused by the misalignment between the drive axis and the gyro detection axis will be explained in more detail using Figure 12. Figure 12 is a schematic diagram to explain the misalignment between the drive axis and the gyro detection axis. Assume that the drive axis (xy) of the actuator is rotated by θ with respect to the gyro detection axis XY (direction of wobble) of the gyro sensor. Let G be the wobble angle in the direction of pitch wobble and yaw wobble (the wobble angular velocity from the gyro sensor can also be used). P , G Y If we decompose the actuator into two effective drive direction components, we can consider the actuator's drive direction components as the first drive direction and the second drive direction, respectively, as A x , Ay as, A y =G P cosθ+G Y sinθ ···(5) A x =-G P sinθ+G Y cosθ ···(6) This can be expressed as follows: That is, the actuator is A in equations (5) and (6). y , A x The displacement amount is set to correct this as the target signal for image stabilization. This corrects the crosstalk. When θ=0, A y =G P , A x =G Y This is the result. If the above trigonometric function calculations pose a problem in terms of CPU or DSP processing power, cosθ ≈ 1-θ 2 / 2 ···(7) sinθ≒θ ···(8) Using the approximate formula, A y ≒G P (1-θ 2 / 2)+G Y θ ···(9) A x ≒-G P θ+G Y (1-θ 2 / 2) ···(10) You can simplify the calculation as follows.

[0097] Returning to the block diagram in Figure 11, G Y The multipliers 573Y and 575Y multiply by coefficients based on θ (in the example above, 573Y is cosθ and 575Y is sinθ), G P The multipliers 573P and 575P multiply by coefficients based on θ (in the example above, 573P is cosθ and 575P is -sinθ). Then, the adder 577 adds -G P sinθ and G Y Adding cosθ, the displacement target signal A for yaw deflection correction is given by equation (6). x =-GP sinθ+G Y We can obtain cosθ, which is the target signal P in the yaw direction. REF-X Similarly, adder 579 will result in G P cosθ and G Y Adding sinθ, the displacement target signal for pitch wobble correction, Ay=G, is given by equation (5). P cosθ+G Y We can obtain sinθ, which is the target signal P in the pitch direction. REF-P This is the result. P REF-P This is the displacement amount in the pitch direction that serves as the basis for roll correction, and is input to the DSP536, which then corrects it in accordance with the change in roll position detection sensitivity to obtain the roll position command value P. REF-R The output is: Also, P REF-P and P REF-R The DSP534 controls the target signals P from coils Y1 and Y2. REF-Y1 and P REF-Y2 The signals are then distributed accordingly. In this embodiment, the yaw deviation detection signal and the pitch deviation detection signal are corrected for each other based on the directional misalignment between the pitch axis and the first drive axis, or between the yaw axis and the second drive axis.

[0098] <Fourth Embodiment> A fourth embodiment will be described with reference to Figure 13. Figure 13 is a block diagram of a sixth specific example of the actuator control device 400. The difference between the block diagram of Figure 13 and the block diagram of Figure 6 is that Figure 13 is a block diagram of a case where both the crosstalk correction described in this application and the crosstalk correction described in Patent Document 1 are performed. Patent Document 1 describes the correction when an offset occurs in the pitch and yaw position detection due to roll rotation. The block diagram of Figure 13 includes a mechanism for correcting the offset in the pitch and yaw position detection based on the roll rotation angle θ.

[0099] The interface circuit 514 receives a digital angular velocity signal from the roll gyro sensor 334. The gyro DSP 524 receives a shake angle signal G based on the angular velocity signal received by the interface circuit 514.R Outputs G R This becomes the roll rotation angle θ.

[0100] The position detection unit 540 detects the Hall voltage V generated by the corresponding Hall element 8. + , V - Based on this, a digital position detection value P indicates the position (displacement) of the movable part. FB-X This generates P FB-X Because roll rotation causes offset (crosstalk), the offset correction unit 546 corrects the offset to obtain a corrected position detection value P. FB-X-2 The controller 570 generates the position command value P. REF-X And the offset-corrected position detection value P FB-X-2 Based on the detected position value P FB-X-2 The position command value P REF-X Control command value S to match REF-X Generates.

[0101] Similarly, the position detection units 542 and 544 detect the Hall voltage V generated by the corresponding Hall elements 14 and 16. + , V - Based on this, a digital position detection value P indicates the position (displacement) of the movable part. FB-Y1 , P FB-Y2 This generates the pitch displacement detection signal. However, depending on the configuration, roll rotation may cause an offset (crosstalk) in the pitch displacement detection signal. FB-Y1 and P FB-Y2 None of these independently indicate pitch displacement. Therefore, in this embodiment, if an offset occurs in the pitch displacement detection signal due to roll rotation, the pitch position command value is corrected, rather than the position detection signal, and the corrected pitch position command value P REF-P Outputs the corrected pitch position command value P. REF-P Based on this, the DSP536 performs a correction to correspond to the change in roll position detection sensitivity, thereby adjusting the roll position command value P. REF-R Outputting the pitch and roll position command values ​​P REF-P and P REF-RBased on this, the DSP534 sets the position command values ​​P for Y1 and Y2. REF-Y1 , P REF-Y2 The distribution of data is the same as in the case of Figure 6. Furthermore, in order to reduce the effect of the offset of at least one of the first position information and the second position information caused by roll rotation, at least one of the first position information, the second position information, the yaw drift detection signal, and the pitch drift detection signal may be corrected.

[0102] This technology applies to image stabilization systems that drive the image sensor in three directions, including roll correction, and does not depend on whether the lens is driven together with the image sensor or whether the image sensor and lens are displaced relative to each other. In the type where the image sensor and lens are driven together for image stabilization, the image sensor and lens are tilted together to counteract the tilt of the camera body in the pitch and yaw directions. In the type where the image sensor and lens are displaced relative to each other, the image sensor is shifted relative to the lens to counteract the tilt of the optical axis that occurs when the camera body tilts in the pitch and yaw directions.

[0103] The actuator control devices described above are used in camera modules for mobile phones and other applications. In particular, one suitable application of the actuator control device is in imaging devices equipped with optical image stabilization (OIS) functionality, and furthermore, in imaging devices that can also correct in the roll direction as optical image stabilization. By utilizing this technology, various crosstalks caused by the rotation of movable parts associated with roll-direction image stabilization can be corrected, thereby enabling highly accurate image stabilization.

[0104] In recent years, the use of multi-rotor aircraft (drones) equipped with cameras has become increasingly popular. While yaw, pitch, and roll shakes occur during in-flight photography, the aforementioned actuator control device enables highly accurate shake correction.

[0105] (Note) This specification discloses the following technologies:

[0106] (Item 1) Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A control device that drives the actuator in accordance with the yaw wave detection signal, the pitch wave detection signal, and the roll wave detection signal, Equipped with, The control device corrects the roll shake detection signal such that the effect on rotation around the third drive axis, which occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis, is reduced.

[0107] (Item 2) The imaging apparatus according to item 1, wherein the control device calculates a correction displacement of at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and sets the correction amount of the roll shake detection signal based on the correction displacement.

[0108] (Item 3) The position detector further comprises a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The imaging apparatus according to item 1, wherein the control device calculates the displacement of the image sensor in the direction of the first drive axis or the direction of the second drive axis based on the position detection signal, and sets the correction amount of the roll shake detection signal based on the displacement.

[0109] (Item 4) Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis, A control device that drives the actuator in accordance with the yaw deviation detection signal, the pitch deviation detection signal, and the roll deviation detection signal, Equipped with, The control device corrects the position detection signal to reduce the change in the position detection signal sensitivity of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

[0110] (Item 5) The imaging apparatus according to item 4, wherein the control device calculates a correction displacement of at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and sets the correction amount of the position detection signal sensitivity of the third position information based on the correction displacement.

[0111] (Item 6) The imaging apparatus according to item 4, wherein the control device calculates the yaw displacement of the image sensor based on the first position information, or the pitch displacement of the image sensor based on the second position information, and sets the correction amount for the position detection signal sensitivity of the third position information based on the yaw displacement or the pitch displacement.

[0112] (Item 7) An actuator driver used in an imaging device, The imaging device is Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, An actuator driver that drives the actuator in accordance with the yaw deviation detection signal, the pitch deviation detection signal, and the roll deviation detection signal, Equipped with, The actuator driver is A correction unit corrects the roll shake detection signal so as to reduce the effect on rotation around the third drive shaft caused by displacing the image sensor in at least one of the directions of the first drive shaft and the second drive shaft, A drive unit that drives the actuator based on the corrected roll wobble detection signal, An actuator driver equipped with the following features.

[0113] (Item 8) The actuator driver according to item 7, wherein the correction unit calculates a correction displacement for at least one of the yaw deviation and pitch deviation based on at least one of the yaw deviation detection signal and the pitch deviation detection signal, and sets the correction amount for the roll deviation detection signal based on the correction displacement.

[0114] (Item 9) The imaging device further includes a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The actuator driver according to item 7, wherein the correction unit calculates the displacement of the image sensor in the direction of the first drive axis based on the first position information, or the displacement of the image sensor in the direction of the second drive axis based on the second position information, and sets the correction amount of the roll shake detection signal based on the calculated displacement.

[0115] (Item 10) An actuator driver used in an imaging device, The imaging device is Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis, Equipped with, The actuator driver is A correction unit corrects the third position information so as to reduce the change in the position detection signal sensitivity of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis, Based on the corrected third position information, a drive unit drives the actuator, An actuator driver equipped with the following features.

[0116] (Item 11) The actuator driver according to item 10, wherein the correction unit calculates a correction displacement of at least one of the yaw deviation and pitch deviation based on at least one of the yaw deviation detection signal and the pitch deviation detection signal, and sets the correction amount of the position detection signal sensitivity of the third position information based on the correction displacement.

[0117] (Item 12) The actuator driver according to item 10, wherein the correction unit calculates the yaw displacement of the image sensor based on the first position information, or the pitch displacement of the image sensor based on the second position information, and sets the correction amount of the position detection signal sensitivity of the third position information based on the yaw displacement or the pitch displacement.

[0118] (Item 13) The imaging apparatus according to any one of items 1 to 6, wherein the yaw deviation detection signal and the pitch deviation detection signal are corrected for each other based on the directional misalignment between the pitch axis and the first drive axis, or the directional misalignment between the yaw axis and the second drive axis.

[0119] (Item 14) The actuator driver according to any one of items 7 to 12, wherein the yaw run detection signal and the pitch run detection signal are corrected for each other based on a directional misalignment between the pitch axis and the first drive axis, or a directional misalignment between the yaw axis and the second drive axis.

[0120] (Item 15) The imaging apparatus according to any one of items 4 to 6, which corrects at least one of the first position information, the second position information, the yaw shake detection signal, and the pitch shake detection signal in order to reduce the effect of offset of at least one of the first position information and the second position information caused by rotation around the third drive shaft.

[0121] (Item 16) An actuator driver according to any one of items 10 to 12, which corrects at least one of the first position information, the second position information, the yaw run detection signal, and the pitch run detection signal in order to reduce the effect of an offset of at least one of the first position information and the second position information caused by rotation around the third drive shaft. [Explanation of symbols]

[0122] 2 Image sensors 4, 6 X coils 8 X holes 10, 12 Y coil Halls 14 and 16 (Y Hall) 18 OIS moving part 20, 22X permanent magnet 24, 26 Y permanent magnets 24a, 26a Polarity lines 300 Imaging devices 302 Image sensor 304 lens 306 Processors 308 Gyroscope Sensor 310 Lens Holder 312 AF Coil 314 AF permanent magnet 316 circuit boards 318 OIS Coil 320 Position detection device 322 OIS permanent magnet 324 OIS York 330, 332, 334 Gyroscope Sensors 400 Actuator Control Device 402 AF Actuator 404 OIS Actuator 406 Position detector 510, 512, 514 Interface Circuits 520, 522, 524 Gyro DSP 530, 531, 532, 533, 534, 536, 537 DSP 540, 542, 544 Position detection unit 546, 547 Offset correction section 548, 550, 552 Hall amplifier 554, 556, 558 A / D converters 560, 562, 564 constant current circuit 570, 572, 574 controllers 573Y, 573P, 575Y, 575P multiplier 576, 577, 578, 579, 580 Error detectors 582, 584, 586 PID controllers 590, 592, 594 Driver section

Claims

1. Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A control device that drives the actuator in accordance with the yaw wave detection signal, the pitch wave detection signal, and the roll wave detection signal, Equipped with, The control device corrects the roll shake detection signal such that the effect on rotation around the third drive axis, which is caused by displacing the image sensor in at least one of the directions of the first drive axis and the second drive axis, is reduced.

2. The imaging apparatus according to claim 1, wherein the control device calculates a correction displacement of at least one of the yaw shake detection signal and the pitch shake detection signal, and sets the correction amount of the roll shake detection signal based on the correction displacement.

3. The position detector further comprises a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The imaging apparatus according to claim 1, wherein the control device calculates the displacement of the image sensor in the direction of the first drive axis or the direction of the second drive axis based on the position detection signal, and sets the correction amount of the roll shake detection signal based on the displacement.

4. Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis, A control device that drives the actuator in accordance with the yaw deviation detection signal, the pitch deviation detection signal, and the roll deviation detection signal, Equipped with, The control device corrects the position detection signal so as to reduce the change in the position detection signal sensitivity of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis.

5. The imaging apparatus according to claim 4, wherein the control device calculates a correction displacement of at least one of the yaw shake and pitch shake based on at least one of the yaw shake detection signal and the pitch shake detection signal, and sets a correction amount for the position detection signal sensitivity of the third position information based on the correction displacement.

6. The imaging apparatus according to claim 4, wherein the control device calculates the displacement of the image sensor in the yaw direction based on the first position information, or the displacement of the image sensor in the pitch direction based on the second position information, and sets a correction amount for the position detection signal sensitivity of the third position information based on the displacement in the yaw direction or the displacement in the pitch direction.

7. An actuator driver used in an imaging device, The imaging device is Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, An actuator driver that drives the actuator in accordance with the yaw deviation detection signal, the pitch deviation detection signal, and the roll deviation detection signal, Equipped with, The actuator driver is A correction unit corrects the roll shake detection signal so as to reduce the effect on rotation around the third drive shaft caused by displacing the image sensor in at least one of the directions of the first drive shaft and the second drive shaft, A drive unit that drives the actuator based on the corrected roll wobble detection signal, An actuator driver equipped with the following features.

8. The actuator driver according to claim 7, wherein the correction unit calculates a correction displacement for at least one of the yaw deviation and pitch deviation based on at least one of the yaw deviation detection signal and the pitch deviation detection signal, and sets the correction amount for the roll deviation detection signal based on the correction displacement.

9. The imaging device further includes a position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis. The actuator driver according to claim 7, wherein the correction unit calculates the displacement of the image sensor in the direction of the first drive axis based on the first position information, or the displacement of the image sensor in the direction of the second drive axis based on the second position information, and sets the correction amount of the roll shake detection signal based on the calculated displacement.

10. An actuator driver used in an imaging device, The imaging device is Image sensor and A shake detection element that generates yaw shake detection signals, pitch shake detection signals, and roll shake detection signals that indicate shake around the yaw axis, pitch axis, and roll axis acting on the image sensor, An actuator configured to independently displace the image sensor in the direction of a first drive axis which should be parallel to the pitch axis, in the direction of a second drive axis which should be parallel to the yaw axis, and to rotate it around a third drive axis which should be parallel to the roll axis, A position detector that generates a position detection signal including first position information relating to the position of the image sensor in the direction of the first drive axis, second position information relating to the position of the image sensor in the direction of the second drive axis, and third position information relating to the amount of rotation of the image sensor around the third drive axis, Equipped with, The actuator driver is A correction unit corrects the third position information so as to reduce the change in the position detection signal sensitivity of the third position information that occurs when the image sensor is displaced in at least one of the directions of the first drive axis and the second drive axis, A drive unit that drives the actuator based on the corrected third position information, An actuator driver equipped with the following features.

11. The actuator driver according to claim 10, wherein the correction unit calculates a correction displacement of at least one of the yaw deviation and pitch deviation based on at least one of the yaw deviation detection signal and the pitch deviation detection signal, and sets a correction amount for the position detection signal sensitivity of the third position information based on the correction displacement.

12. The actuator driver according to claim 10, wherein the correction unit calculates the yaw displacement of the image sensor based on the first position information, or the pitch displacement of the image sensor based on the second position information, and sets the correction amount of the position detection signal sensitivity of the third position information based on the yaw displacement or the pitch displacement.

13. The imaging apparatus according to any one of claims 1 to 6, wherein the yaw deviation detection signal and the pitch deviation detection signal are corrected for each other based on the directional misalignment between the pitch axis and the first drive axis, or the directional misalignment between the yaw axis and the second drive axis.

14. The actuator driver according to any one of claims 7 to 12, wherein the yaw run detection signal and the pitch run detection signal are corrected for each other based on a misalignment between the pitch axis and the first drive axis, or a misalignment between the yaw axis and the second drive axis.

15. The imaging apparatus according to any one of claims 4 to 6, wherein the first position information, the second position information, the yaw shake detection signal, and the pitch shake detection signal are corrected in order to reduce the effect of an offset of at least one of the first position information and the second position information caused by rotation around the third drive shaft.

16. The actuator driver according to any one of claims 10 to 12, which corrects at least one of the first position information, the second position information, the yaw run detection signal, and the pitch run detection signal in order to reduce the effect of an offset of at least one of the first position information and the second position information caused by rotation around the third drive shaft.

Images