JP2010112978A - Lens drive device, lens position detecting device, and imaging apparatus using them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device which can form an imaging device in a small size and repeats functional elements at high speed and has high positional accuracy.
In an image pickup apparatus (500) that picks up an optical image incident from an optical axis direction, a crossing direction (X, Z axis) that holds a functional element (401, 402) and intersects the optical axis direction (Y axis). A first driven body (400) that is movable in the direction of movement, a first driving magnet (210x, 210z) that is movable alternately in the crossing direction and is magnetized alternately in N and S poles, A plurality of first flat coils (220x, 220z) arranged opposite to the drive magnet in the cross direction, a first position sensor for detecting a relative position between the first flat coil and the drive magnet, A first energization control unit (90) that switches energization to the first flat coil based on a result detected by the one-position sensor.
[Selection] FIG.

Description

  The present invention relates to an imaging apparatus such as a camera or a video camera that moves a functional element such as a lens in a direction crossing the optical axis direction of the lens.

In general, in the auto focus function and the zoom function, the position of an optical element such as a focus movable lens or a zoom movable lens is moved in the optical axis direction. According to Patent Document 1, the position adjustment of these optical elements is arranged so as to be opposed to the fixed field magnet, and an elongated fixed field magnet that is alternately magnetized with N and S poles along the longitudinal direction. A linear actuator including a movable armature coil is used. Further, in an imaging apparatus with a vibration-proof function capable of correcting camera shake and a lens, the position of the lens or imaging device is detected in a direction perpendicular to the optical axis direction and moved in a predetermined direction. According to Patent Document 2, a linear motor mechanism that moves in a direction perpendicular to the optical axis direction is disclosed.
JP-A-7-120653 JP 2000-039641 A

  However, imaging devices such as cameras and video cameras are required to be further reduced in size and weight in order to meet the demand for reduction in size and weight. In the electromagnetic driving device disclosed in Patent Document 1, a relatively heavy magnet and a yoke are arranged on the upper and lower and left and right sides of a movable member that accommodates a lens, and the position detection device is also arranged on the outer periphery of the imaging device. It is difficult to reduce the size and weight. Further, in the linear motor disclosed in Patent Document 2, a linear motor driving device is built in the lens barrel, and there are many parts such as a translation mechanism and a rod for transmitting the driving. For this reason, also in the magnetic drive device in Patent Document 2, the size of the lens barrel increases, and it is difficult to reduce the size and weight of the imaging device.

  In view of such circumstances, the present invention aims to provide an imaging apparatus that can form an imaging apparatus in a small size, and that has high functional position and high repeatability.

As means for solving the above problems, the following configuration is provided.
An image pickup apparatus according to a first aspect is an image pickup apparatus that picks up an optical image incident from an optical axis direction. A first driven body that is movable in a crossing direction that intersects the axial direction is installed. In the first driven body, first driving magnets alternately magnetized in N and S poles are arranged side by side in the crossing direction. A plurality of first flat coils are installed on the substrate on the surface facing the first drive magnet, and a first position sensor for detecting the relative position of the first flat coil and the drive magnet is installed on the substrate. Yes. The imaging device according to the first aspect includes a first energization control unit that switches energization to the first flat coil based on a result detected by the first position sensor.

  The image pickup apparatus according to the second aspect has an optical element that moves in the optical axis direction, and a second driven body having a zoom function and a focus function is installed by holding the optical element and moving it in the optical axis direction. The second driven body is movable in the optical axis direction or the circumferential direction, and the second driving magnet is alternately magnetized in the N pole and the S pole and arranged side by side in the optical axis direction or the circumferential direction. . A plurality of second flat coils are installed on the substrate on the surface facing the second drive magnet, and a second position sensor for detecting a relative position between the second flat coil and the second drive magnet is provided on the substrate. It is installed. The imaging device according to the second aspect includes a second energization control unit that switches energization to the second flat coil based on a result detected by the second position sensor.

  According to the magnetic drive device of the present invention, the flat coil, the position sensor, and the energization control unit can be installed on the same substrate, and the position sensor is small and can detect the position with high accuracy. There is an effect of cost reduction due to reduction in size and weight, and reduction in the number of parts.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<< First Embodiment >>
<Overall structure>
FIG. 1 is an exploded perspective view showing the configuration of the magnetic drive device 100 of the present embodiment, and FIG. 2 is a YZ cross-sectional view at the optical axis center LC of the magnetic drive device 100 shown in FIG. 1 and 2 also show a fixed barrel 70 that holds the magnetic drive device 100. FIG.

  The main configuration of the magnetic drive device 100 includes a drive magnet 10, an annular substrate 20, a drive ring 50, and a control unit 90.

  The drive magnet 10 has a fan shape when viewed from the Y-axis direction, and includes a yoke 11 and a magnet 12. The drive magnet 10 can rotate freely around the drive ring 50 inside the fixed barrel 70. The drive magnet 10 is composed of a first drive magnet 10a and a second drive magnet 10b, and the yoke 11 is composed of a first yoke 11a and a second yoke 11b. A magnetic flux is formed from the first drive magnet 10a to the second drive magnet 10b. The drive magnet 10 is manufactured in such a manner that the first yoke 11a and the second yoke 11b are joined after the annular substrate 20 is installed in the fixed barrel 70 in the manufacturing process in order to sandwich the annular substrate 20. . The first drive magnet 10a and the second drive magnet 10b are disposed on the inner surface side of the yoke 11 with the flat coil 21 therebetween so as to face each other.

  An annular substrate 20 is installed between the first drive magnet 10a and the second drive magnet 10b. On the annular substrate 20, a flat coil 21 and a hall sensor H (see a broken line range in FIG. 2) that is a part of the magnetic system position sensor unit 40 are installed. The outer edge portion of the annular substrate 20 is fixed to the fixed lens barrel 70 and is arranged perpendicular to the optical axis center LC. Wiring (not shown) connected from the flat coil 21 and the magnetic position sensor unit 40 is wired to supply power to the flat coil 21 and receive position information from the magnetic position sensor unit 40. And a power source (not shown). The flat coil 21, the hole sensor H, the control unit 90, and the wiring connected thereto are fixed to the annular substrate 20 or the fixed lens barrel 70. Therefore, since the flat coil 21, the hole sensor H, and the wiring connected to them do not move, poor contact and disconnection thereof hardly occur.

  The drive ring 50 is formed in a cylindrical shape, and a groove is formed on the inner periphery thereof. The yoke 11 is fixed to a part of the drive ring 50. A bearing 52 for rotating and guiding is provided on the outer periphery of the drive ring 50, and the drive ring 50 is connected to the fixed barrel 70 to be rotatable. That is, the drive ring 50 can freely rotate 360 degrees or more about the optical axis center LC inside the fixed barrel 70.

  A holder 51 is installed inside the drive ring 50, and a groove that meshes with a groove formed on the inner periphery of the drive ring 50 is formed on the outer periphery of the holder 51. Further, the holder 51 is provided with a rotation stop 53 that guides the holder 51 so that the holder 51 does not rotate by moving in the Y-axis direction. The other end of the rotation stop 53 is connected to the fixed barrel 70. An optical lens 54 is installed inside the holder 51, and an optical system such as a focus movable lens or a zoom movable lens is installed.

  With the above configuration, when the drive magnet 10 rotates, the yoke 11 connected to the drive magnet 10 rotates together with the drive ring 50. With the rotation of the drive ring 50, the holder 51 is movable in the + Y direction and the -Y direction in the direction of the optical axis center LC (Y axis).

<Structure of drive magnet 10>
FIG. 3A is a cross-sectional view of the first drive magnet 10a on the Y-axis surface, and FIG. 3B is a configuration diagram of the first drive magnet 10a viewed from the second drive magnet 10b side. Since the first drive magnet 10a and the second drive magnet 10b have basically the same structure and only the polarity of the magnet 12 is different, the first drive magnet 10a will be described as a representative.

  As shown in FIG. 3A, the cross section of the yoke 11 has a crank shape, and a magnetic material such as iron is used to provide the function as the yoke 11. As shown in FIG. 2, the first yoke 11a and the second yoke 11b face each other and are joined by a fan-shaped inner edge (lower part of the drawing). Moreover, the 1st magnet 12a is arrange | positioned in the shape which follows a fan-shaped outer edge part (drawing upper part). As shown in FIG. 3 (b), the magnet 12 is magnetized on the S pole and the N pole in a direction parallel to the plane of the yoke 11, and six small magnets in which adjacent magnetic poles have the same polarity. A 5-pole multipole magnet is used. The two poles at both ends are not included. Note that the magnetic pole configuration of the magnet may be configured in a direction perpendicular to the plane of the yoke 11. The magnet 12 can increase the strength of the magnetic force by using a neodymium magnet having high performance as a magnet. Further, the magnet 12 is not limited to an integrally molded magnet, and may be a magnet in which divided pieces are combined.

  As described above, the drive magnet 10 is composed of the yoke 11 and the magnet 12 and is a mover that does not require electrical wiring. Therefore, it is possible to continue the rotational motion of 360 degrees or more continuously around the drive ring 50. is there.

<Structure of the annular substrate 20>
FIG. 4 is a view of the annular substrate 20 on which the flat coil 21 is installed as viewed from the first drive magnet 10a side (hereinafter referred to as the “surface” of the annular substrate 20). The flat coil 21 is wound in a trapezoidal shape with a current-carrying material such as a copper wire, and a plurality of flat coils 21 are arranged so that the outer edge of the annular substrate 20 is arranged in an annular shape. The flat coil 21 is installed on the surface of the annular substrate 20, and the flat coil 21 is formed of a three-phase connection of the U phase, the V phase, and the W phase, and six sets are arranged on the substrate. In the present embodiment, the three-phase connection will be described. However, the three-phase connection or more may be used, or the two-phase connection may be used.

FIG. 5 is a diagram in which the flat coil 21 and the Hall sensor H are installed on the annular substrate 20.
In the present embodiment, as shown in FIG. 5A, a flat coil 21 is installed in the substrate of the annular substrate 20, and the second drive magnet 10b side of the annular substrate 20 (hereinafter referred to as “ Hall sensor H is installed on the back side. By forming and embedding a groove or a through hole in which the flat coil 21 can be accommodated in the annular substrate 20, a structure that does not protrude from the annular substrate 20 can be obtained. When installing the flat coil 21 in the through hole, the flanges 22 may be installed on both sides of the flat coil 21 to facilitate manufacture. The flange 22 may be formed of a material having elasticity, and may be formed using a resin or the like, and the flat coil 21 can be fixed by simply inserting the flat coil 21 into the through hole.

  The structure that does not protrude from the annular substrate 20 can form a shorter distance between the first magnet 12a and the second magnet 12b than when the flat coil 21 is simply disposed on the front or back surface of the annular substrate 20. Since a strong magnetic field can be applied to the flat coil 21, a strong driving force can be generated. As a result, the magnet 12 can be reduced in size and the number of windings of the flat coil 21 can be reduced, and the magnetic drive device 100 can be reduced in size and weight.

  The magnetic position sensor unit 40 includes a hall sensor H and a sensor magnet 42, and can detect a position without contacting each other. Therefore, the Hall sensor H is installed on the annular substrate 20 at a predetermined angle, and the sensor magnet 42 is installed on the second magnet 12b. The sensor magnet 42 may be installed on the first magnet 12a.

  As shown in FIG. 5A, the hall sensor H is installed on the back surface of the annular substrate 20. This is because the output from the hall sensor H is higher when the distance between the hall sensor H and the sensor magnet 42 is narrower, so it is better to bring them closer together. On the other hand, as shown in FIG. 5B, when the thickness of the second magnet 12b is thin, the Hall sensor H and the sensor magnet 42 may collide. Therefore, similarly to the flat coil 21, a groove or a through hole is formed in the annular substrate 20, and the Hall sensor H can be accommodated in the annular substrate 20.

  FIG. 6A is a view as seen from the back surface of the annular substrate 20. FIG. 6B is a diagram in which the magnetic position sensor unit 40 arranged in an annular shape shown in FIG. 6A is linearly extended and a graph of changes in the magnetic flux density B in the Hall sensor H.

  As shown in FIG. 6A, the hall sensors H are arranged side by side from H1 to H18 in the rotation direction. The mounting angle of the hall sensor H is preferably equal to or less than the pitch of the installation angle of the flat coil 21. In the present embodiment, the same number of flat coils 21 as the flat coils 21 are installed at the installation angle pitch. The sensor magnet 42 is formed in a size that covers three Hall sensors H. The Hall sensor H is installed at the inner edge of the annular substrate 20 and is arranged at a position where the influence of the magnetic field of the magnet 12 is small.

  As shown in FIG. 6B, the sensor magnet 42 is inclined along the direction of rotation (advance), and forms a magnetic field in which the distance from the Hall sensors H arranged in a row changes sequentially. Yes. In FIG. 6B, the gradient magnetic field is changed in the rotation direction by changing the thickness of the sensor magnet 42. However, even if there is no geometric inclination, the magnetic force of the magnet may be changed sequentially.

  Assuming that the sensor magnet 42 covers from the hall sensor H4 to the hall sensor H6, the magnetic flux density B of the hall sensor H draws a curve as shown by a solid line in the graph. When the drive magnet 10 moves in the rotation direction and the sensor magnet 42 covers from the hall sensor H5 to the hall sensor H7, a curve is drawn so that the magnetic flux density B is displayed by a broken line in the graph. The position detection calculation unit 91 (see FIG. 8) of the control unit 90 provides three Hall sensors H (see FIG. 8) that exceed the threshold Bth by providing threshold values Bth of the values of the magnetic flux density B in each Hall sensor H. In 6 (b), it is possible to quickly identify that the center Hall sensor H is near the center of the drive magnet 10 by identifying the Hall sensor H4 to the Hall sensor H6).

  Further, a gradient magnetic field is applied to the sensor magnet 42. The storage unit 94 (FIG. 8) stores the gradient of the gradient magnetic field output from the Hall sensor H corresponding to the rotation angle and the positional information of all the Hall sensors H on the substrate. For these pieces of position information, the sensor position may be previously measured with a reference tool or the like alone on the substrate alone. The position of the Hall element on the substrate is set at the center of the gradient magnetic field. Therefore, by detecting how much the output of the Hall sensor H4 changes from the median value of the gradient of the gradient magnetic field, the position of the drive magnet 10 can be specified with high accuracy. For example, the output from the hall sensor H5 becomes Bφ at a position before the drive magnet 10 rotates by an angle Δφ from the state where the hall sensor H5 is at the center position of the drive magnet 10 (center of the gradient magnetic field). Therefore, the change amount Bφ−Bp from the median value of the gradient magnetic field is obtained, and it can be seen that the drive magnet 10 is at a position rotated by the angle Δφ by multiplying this by the gradient of the gradient magnetic field corresponding to the rotation angle.

  In this embodiment, the gradient magnetic field is arranged so that the intensity of the gradient magnetic field is increased clockwise (+ direction), but may be arranged so as to be decreased. Even when the values of the four hall sensors H exceed the threshold value Bth, it can be specified that the middle position of the four hall sensors H is the center of the drive magnet 10.

  In the present embodiment, the Hall sensor H is installed on the inner edge side of the annular substrate 20, but may be formed on the outer edge portion. The Hall sensor H installed at the outer edge is also a position where the influence of the magnetic field of the magnet 12 is small. Although the Hall sensor H installed at the outer edge portion improves the accuracy of measuring the position of the drive magnet 10, it becomes difficult to control due to an increase in inertia (inertia).

  FIG. 7 is a view showing the optical position sensor unit 45. In FIG. 6, the magnetic position sensor unit 40 performs position detection by the magnetism of the Hall sensor H and the sensor magnet 42, but may perform position detection by light. FIG. 7 is a graph in which the optical position sensor unit 45 is straightened in the same manner as in FIG. 6B and a graph of changes in the measurement distance L in the optical distance measuring device I. In this case, the optical position sensor unit 45 replaces the Hall sensor H with the optical distance measuring device I, uses the sensor magnet 42 as a reflecting plate 46 with an inclination angle, and reflects the light emitted from the optical distance measuring device I with the reflecting plate 46. And the distance is measured by receiving the reflected light with the optical distance measuring device I. The position detection can measure the position of the drive magnet 10 by specifying the optical distance measuring device I whose measured distance is equal to or less than the threshold value Lth, similarly to the position detection by magnetism.

  With the above configuration, the magnetic drive device 100 can move the drive magnet 10 to a predetermined angle. Further, it is not necessary to connect the drive magnet 10 and the movement of the annular substrate 20 is eliminated, so that the connection portion of the electric circuit such as the flat coil 21 and the Hall sensor H installed on the annular substrate 20 can be fixed. Therefore, the possibility of contact failure and disconnection can be reduced, and the magnetic drive device 100 can be operated stably.

  FIG. 8 is a diagram showing a drive control system of the control unit 90. The control unit 90 is installed on the annular substrate 20. The control unit 90 controls the power feeding timing to the flat coil 21 from the position information of the magnetic system position sensor unit 40 or the optical system position sensor unit 45, rotates the drive ring 50 by rotating a predetermined angle, and thereby The lens 54 installed inside is moved to a predetermined position in the direction of the optical axis center LC.

  The drive control system of the control unit 90 of the magnetic drive device 100 includes a position detection calculation unit 91, a switch control unit 92, a three-phase command conversion control unit 93, and a storage unit 94 such as a memory. The position detection calculation unit 91 calculates the angle of the drive magnet 10 from the detector result of the Hall sensor H, and the switch control unit 92 uses the calculated angle information of the drive magnet 10 to calculate the selection logic of the flat coil 21 to be controlled. I have control. The three-phase command conversion control unit 93 gives a three-phase command value to each of the U-phase, V-phase, and W-phase current amplifiers AP based on the angle information of the drive magnet 10 when a drive command voltage is given. The storage unit 94 stores a gradient of the gradient magnetic field output from the Hall sensor H corresponding to the rotation angle, position information on the substrate of all the Hall sensors H, and the like.

  The current amplifier part AP that amplifies the three currents is provided with a series resistor R that senses current for overcurrent protection, and the current amplifier part AP is connected to the switch control part 92. The control unit 90 performs on / off control of a plurality of open / close switch units SW connected to the flat coil 21 and applies currents Iu, Iv, and Iw to the flat coil 21 to generate a magnetic field. Thereby, the drive magnet 10 can rotate by attracting or repelling the drive magnet 10.

  FIG. 9 illustrates on / off control by the switch control unit 92. In the column direction of FIG. 9, the switch SW number corresponding to each flat coil 21 is indicated, and the angle of the drive magnet 10 is indicated in the row direction. The switch control unit 92 switches the three-phase coil of each flat coil 21 at a predetermined angle. In the table, “◯” indicates that the coil is energized, and “x” indicates that the coil is not energized. Show. As shown in FIG. 9, since the flat coil 21 contributing to the drive magnet 10 is energized, the power consumption can be reduced.

  Further, the switch control unit 92 can monitor the power supply state, and when the power supply is stopped, each switch is cut off from the current amplifier, and all the switches are in a conductive state. As a result, the coil short mode is established, and the electromagnetic damper is generated in the mover by the counter electromotive current generated by the relative movement between the drive magnet 10 and the flat coil 21, and the rotation can be stopped. In order to make the drive magnet 10 stand still at a predetermined position, the control unit 90 can make the drive magnet 10 stand still at a predetermined position by performing feedback control with a drive control system.

<< Second Embodiment >>
In the first embodiment, the movement in the rotation direction is changed to the movement in the linear direction. However, the magnetic drive device 200 of the present embodiment moves in the linear direction and can directly move the optical system such as a lens in a straight line. Note that the same parts and mechanisms used in the present embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 10A is a perspective view showing the configuration of the magnetic drive device 200 of the present embodiment, and FIG. 10B is a configuration diagram seen from the direction of the optical axis center LC in FIG. 10A.

  The main configuration of the magnetic drive device 200 includes a drive magnet 210, a rectangular substrate 220, a holder 250, and a control unit 90. The drive magnet 210 is composed of a yoke 211 and a magnet 212, and does not require electrical wiring. The yoke 211 is U-shaped when viewed from the direction of the optical axis center LC, and is rotated 90 degrees to the right. One end of the yoke 211 is connected to the holder 250. The magnet 212 is formed in a rectangular shape and uses a 5-pole multipole magnet. The magnet 212 includes a first magnet 212a and a second magnet 212b, and is installed at the U-shaped tip of the yoke 211 and inside the U-shape so as to face each other.

  The rectangular substrate 220 is formed in a rectangular shape whose one side is long in the optical axis direction (Y-axis direction), and the flat coil 221 and the magnetic system position sensor unit 40 are installed in the through hole or groove of the rectangular substrate 220. The rectangular substrate 220 is disposed at a position where the opposed first magnet 212 a and second magnet 212 b sandwich the flat coil 221. In addition, since the rectangular substrate 220 is fixed to a fixed barrel (not shown) or the like, fixing the wiring cable DC of the electric circuit or the like as in the first embodiment can prevent contact failure and disconnection. Therefore, the magnetic drive device 200 can be operated stably. The length of the rectangular substrate 220 in the Y-axis direction is the minimum required for the movement distance of the optical system. In addition, the buffer part (not shown) when the magnetic drive device 200 runs away on the rectangular substrate 220 or the fixed lens barrel is installed.

  The flat coil 221 is formed by winding a current-carrying material such as a copper wire in a rectangular shape, and is arranged at regular intervals in the Y-axis direction of the rectangular substrate 220. The flat coil 221 is installed in the through hole of the rectangular substrate 220, and the flat coil 221 is formed by three-phase connection of the U phase, the V phase, and the W phase, and a predetermined number is arranged on the substrate according to the moving distance. Yes. The control of the flat coil 221 switches the energization to the flat coil 21 at every predetermined angle in the first embodiment, but switches the energization to the flat coil 221 at every predetermined distance in the Y-axis direction. 210 is moved. In addition, the connection method of the flat coil 221 may be three-phase connection or more, or may be two-phase connection.

  The magnetic position sensor unit 40 is the same as that of the first embodiment, the Hall sensor H is installed in the groove of the rectangular substrate 220, and the sensor magnet 42 is installed on the yoke 211 side. Similarly, the magnetic position sensor unit 40 can select either the magnetic method or the optical method.

  The holder 250 includes a guide shaft 251 and an optical system lens 253. The holder 250 has a role of holding the lens 253 and a role of moving the movement in the optical axis direction along the guide shaft 251. In the present embodiment, two guide shafts 251 including a first guide shaft 251a and a second guide shaft 251b are arranged. The guide shaft 251 can be moved in the optical axis direction by using a slide bearing or a rolling bearing so that the center of the lens 253 installed in the holder 250 is not deviated from the optical axis center LC. In addition, the control unit 90 performs a feedback process to hold the magnetic drive device 200 at a predetermined position. The following shows a modification of the magnetic drive device 200. In the following, differences from the magnetic drive device 200 will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

<Modification 1>
FIG. 11A is a perspective view showing a magnetic drive device 300 in which fixed rings 252 for fixing the guide shaft 251 are installed at both ends of the guide shaft 251. FIG. 11B is a top view of FIG. It is.

  The magnetic drive device 300 is installed by adding a fixed ring 252 to the magnetic drive device 200. A piezoelectric actuator 254 can be installed on the fixed ring 252 to limit the movement of the holder 250. For example, the width of the first guide shaft 251a and the second guide shaft 251b is changed by installing the piezoelectric actuator 254 on both ends of the second guide shaft 251b of one guide shaft 251 and operating the piezoelectric actuator 254. The changing direction is moved in the center direction or the outer side direction of the fixed ring 252 and is fixed by increasing the friction between the guide shaft 251 and the holder 250. The operation of the piezoelectric actuator 254 can be activated when power supply is stopped or when the magnetic drive device 300 runs away, thereby protecting the magnetic drive device 300 and the imaging device. The operation of the piezoelectric actuator 254 during normal use is moved to a position where the holder 250 can freely move in the optical axis direction. Further, when the holder 250 is moved to a predetermined position, the piezoelectric actuator 254 is operated to fix the holder 250, thereby eliminating the need for a feedback process for preventing the magnetic drive device 300 from being displaced from the predetermined position. Electricity can be achieved. The piezoelectric actuator 254 is a small and power-saving actuator such as a solenoid actuator or an actuator using a shape memory alloy.

  In addition, as a protection device for the magnetic drive device 300, installing the conductor 222 on the rectangular substrate 220 is also effective as a protection device when the magnetic drive device 300 runs away. Specifically, when the magnetic drive device 300 runs away and the drive magnet 210 comes to the conductor 222 of the rectangular substrate 220 that is out of the movement range, an eddy current is generated in the conductor 222 and attracts or repels the drive magnet 210. The brakes are applied when they are held together. In addition, the protective device of the magnetic drive device 300 can be used as the protective device by installing a magnetic body having a polarity repelling the drive magnet 210 instead of the conductor 222.

<Modification 2>
FIG. 12 shows a magnetic drive device 350 when two holders 250 are installed on the guide shaft 251. In the magnetic driving device 350, the front holder 250 a and the rear holder 250 b are fitted on the same guide shaft 251, and the front yoke 211 a and the rear yoke 211 b are connected to the respective holders 250. The rectangular substrate 220 is formed in a single rectangular shape that is long in the optical axis direction that can cover the range in which the front holder 250a and the rear holder 250b move, and the front holder 250a is operated in the groove or through hole of the rectangular substrate 220. A front flat coil 221a for operating the rear flat coil 221b and a rear flat coil 221b for operating the rear holder 250b are provided. A front magnet 215 is installed on the front yoke 211a, and a rear magnet 216 is installed on the rear yoke 211b. Similarly, the position sensor unit (not shown) is installed on the same rectangular substrate 220 with the front position sensor unit and the rear position sensor unit.

  The magnetic driving device 350 can control the front holder 250a and the rear holder 250b individually. For example, the front holder 250a can be used as a zoom lens, and the rear holder 250b can be used as a focus lens. The magnetic driving device 350 can reduce the number of parts by installing the two holders 250 on the same guide shaft 251, and can further prevent the optical axis center LC from shifting due to the movement of the optical system.

  Since the control unit 90 can control the drive control system of the magnetic drive device 200, the magnetic drive device 300, and the magnetic drive device 350, and the magnetic position sensor unit 40 in the same manner as in the first embodiment, description thereof is omitted. To do. Moreover, although the magnetic drive device 200, the magnetic drive device 300, and the magnetic drive device 350 are installed in the center upper part of the holder 250, you may install in the both sides with a guide shaft.

<< Third Embodiment >>
In the magnetic drive devices of the first and second embodiments, an optical system such as a focus movable lens or a zoom movable lens is moved in the optical axis direction (Y-axis direction). The magnetic drive device 400 according to the present embodiment is moved in a direction (X-axis direction and Z-axis direction) intersecting the optical axis direction (Y-axis direction) and used as, for example, a camera shake prevention mechanism. FIG. 13 is a perspective view showing the configuration of the magnetic drive device 400. 13A shows a lens shift type camera shake prevention mechanism 400a when the functional element installed in the holder 250 as a driven body is a lens, and FIG. 13B shows the functional element installed in the holder 250 as a sensor. The sensor shift type camera shake prevention mechanism 400b is shown.

  In the lens shift type camera shake prevention mechanism 400a, a circular through hole is formed in the center of the holder 250 of the magnetic drive device 400, and a camera shake correction lens 401 is installed. The camera-shake correction lens 401 moves the holder 250 in a direction to correct the deviation of the optical path passing through the optical system, thereby forming a blur-free image on the image sensor 402. On the other hand, the sensor shift type camera shake prevention mechanism 400b arranges the image sensor 402 on the surface (light incident surface) of the holder 250 of the magnetic driving device 400, and moves the holder 250 in a direction to remove the blur of the formed image. A blur-free image is obtained. The lens shift type camera shake prevention mechanism 400a and the sensor shift type camera shake prevention mechanism 400b differ only in the functional elements installed in the holder 250. For this reason, the following description will be made with the magnetic drive device 400 unless otherwise specified.

  The main configuration of the magnetic drive device 400 is a configuration in which one magnetic drive device 200 shown in the second embodiment is installed in the X-axis direction and the Y-axis direction. Note that the piezoelectric actuator 254 and the conductor 222 shown in the first modification of the second embodiment can also be installed. For this reason, the same components and mechanisms used in the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The magnetic drive device 400 includes an X-axis magnetic drive device 450 in the X-axis direction, a Z-axis magnetic drive device 460 in the Z-axis direction, and a holder 250. Each driving device includes a frame 410, a driving magnet 210, and a rectangular substrate 220 having a control unit 90. That is, the X-axis magnetic drive device 450 includes an X-axis frame 410x, an X-axis drive magnet 210x, and an X-axis rectangular substrate 220x, and the Z-axis magnetic drive device 460 includes a Z-axis frame 410z and a Z-axis frame. The shaft driving magnet 210z and the Z-axis rectangular substrate 220z are configured. Further, the control unit 90 controls the X-axis magnetic drive device 450 and the Z-axis magnetic drive device 460 based on information from an angular velocity sensor (not shown) that detects vibrations in the horizontal direction and the vertical direction, and the holder 250. Is moved by a predetermined amount in the direction of removing the vertical and horizontal vibration directions with respect to the optical axis direction, thereby removing the blur of the optical system. For detecting the position of the drive magnet 210, as shown in FIG. 10B, for example, the magnetic system position sensor unit 40 is used, and the Hall sensor H is installed in the groove of the rectangular substrate 220. Is installed on the yoke 211 side. The magnetic position sensor unit 40 can select either a magnetic method or an optical method.

  The frame 410 is composed of two Z-axis frames 410z in the Z-axis direction and two X-axis frames 410x in the X-axis direction. The Z-axis frame 410z is installed in parallel with the Z-axis direction on the same ZX plane, and the X-axis frame 410x is similarly installed in parallel with the X-axis direction on the same ZX plane. .

  The Z-axis frame 410z is fixed by an X guide shaft 251x arranged in parallel with the X-axis direction on the Z-X plane, and the X-axis rectangular substrate 220x is also fixed by the Z-axis frame 410z. An X-axis frame 410x is fitted in the X guide shaft 251x and can move freely in the X-axis direction. An X-axis drive magnet 210x is connected to the X-axis frame 410x, and can be moved in the X-axis direction by driving the X-axis drive magnet 210x.

  The X-axis frame 410x is fixed with a Z guide shaft 251z arranged in parallel with the Z-axis direction on the Z-X plane, and the Z-axis rectangular substrate 220z is similarly fixed with the X-axis frame 410x. A holder 250 is fitted on the Z guide shaft 251z and can move freely in the Z-axis direction. A Z-axis drive magnet 210z is connected to the holder 250, and can move in the Z-axis direction by driving the Z-axis drive magnet 210z. That is, the holder 250 can be moved in the Z-axis direction by the Z-axis magnetic drive device 460, and the X-axis magnetic drive device 450 moves the holder 250 and the Z-axis magnetic drive device 460 in the X-axis direction. It can move freely to a predetermined position on the -Z plane.

  FIG. 14 is a diagram illustrating a main configuration of the imaging apparatus 500. The imaging device 500 includes a body 510 and a lens barrel 520. The lens barrel 520 is provided with a focus movable lens mechanism 530 and a zoom movable lens mechanism 540 in the imaging apparatus 500, and the lens shift type camera shake prevention mechanism 400a shown in the present embodiment is also installed. The focus movable lens mechanism 530 and the zoom movable lens mechanism 540 use the magnetic drive device shown in the first embodiment and the second embodiment.

  The body 510 is provided with a sensor shift type camera shake prevention mechanism 400b. The body 510 includes a spring-shifting mirror 421, a focus sensor 422, a focus glass 423, a pentaprism 424, and a viewfinder 425, in addition to a sensor shift type camera shake prevention mechanism 400b. The body 510 is equipped with a mount 426 for joining with the lens barrel 520. The mount 426 is provided with a contact, and information transmission of various sensors installed in the lens barrel 520, power supply to the magnetic drive device, transmission of a control result, and the like are performed. In addition, the imaging apparatus 500 of the present embodiment performs control of a sensor shift type camera shake prevention mechanism 400b and control of a lens shift type camera shake prevention mechanism 400a installed in the lens barrel 520. In addition, the imaging apparatus 500 may also control the movable movable lens mechanism 530 and the movable movable lens mechanism 540 for zooming.

  Light rays that pass through the lens barrel 520 and enter the body 510 are split into two directions by the spring-lifting mirror 421, one going to the viewfinder 425 side and the other going to the focus sensor 422 side. The light beam traveling toward the viewfinder 425 forms an image with the focus glass 423, changes its direction with the pentaprism 424, and can be viewed with the viewfinder 425. On the other hand, the light beam traveling to the focus sensor 422 side detects whether the focus is in focus by the focus sensor 422, and the detection result is transmitted to the focus movable lens mechanism 530 in the lens barrel 520. In addition, the imaging apparatus 500 causes the focus movable lens mechanism 530 to be in focus by half-pressing a release switch (not shown) by an operator, and retracts the spring-lifting mirror 421 when fully pressed. Is imaged on the image sensor 402.

  The lens barrel 520 is fixed to the Z-axis frame 410z of the magnetic drive device 400 shown in FIG. Further, the Z-axis frame 410z of the magnetic drive device 400 shown in FIG. 13B is fixed to the body 510.

  As described above, the magnetic drive device of the present invention can be miniaturized because the position sensor and the flat coil are installed on the same substrate, and the imaging device can be miniaturized.

FIG. 3 is an exploded perspective view showing a configuration of a magnetic drive device 100. FIG. 3 is a YZ cross-sectional view at the optical axis center LC of the magnetic drive device 100 shown in FIG. 1. (A) is sectional drawing in the Y-axis surface of the 1st drive magnet 10a. (B) is the block diagram which looked at the 1st drive magnet 10a from the 2nd drive magnet 10b side. It is the figure which looked at the annular substrate 20 in which the flat coil 21 was installed from the 1st drive magnet 10a side. (A) is the figure which installed the flat coil 21 in the surface of the annular substrate 20, and installed Hall sensor H in the back surface of the annular substrate 20. FIG. (B) is the figure which embedded the flat coil 21 and the Hall sensor H in the groove | channel formed in the annular substrate 20, or a through-hole. (A) is the figure which looked at the annular substrate 20 from the 2nd drive magnet 10b side. (B) is the figure which extended the magnetic system position sensor part 40 arrange | positioned in the annular | circular shape shown to (a) to a straight line, and the graph of the change of the magnetic flux density B in the Hall sensor H. FIG. 5 is a graph in which an optical position sensor unit 45 is straightened, and a graph of changes in the measurement distance L in the optical distance measuring device I. FIG. 3 is a diagram of a drive control system of a control unit 90. FIG. It is a table | surface of the on / off control by the switch control part 92. (A) is the perspective view which showed the structure of the magnetic drive device 200 of this embodiment. (B) is the block diagram seen from the direction of the optical axis center LC of (a). (A) is the perspective view which showed the magnetic drive device 300 which installed the fixed ring 252 which fixes the guide shaft 251 in the both ends of the guide shaft 251. FIG. (B) is a top view of (a). This is a magnetic drive device 350 when two holders 250 are installed on the guide shaft 251. (A) is the figure which showed the lens shift type camera-shake prevention mechanism 400a. (B) is a diagram showing a sensor shift type camera shake prevention mechanism 400b. It is the figure which showed the main structures of the imaging device 500

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Drive magnet (10a ... 1st drive magnet, 10b ... 2nd drive magnet)
11 ... Yoke (11a ... 1st yoke, 11b ... 2nd yoke)
12 ... Magnet (12a ... 1st magnet, 12b ... 2nd magnet)
DESCRIPTION OF SYMBOLS 20 ... Ring substrate 21 ... Flat coil 22 ... Collar 40 ... Position sensor part, 42 ... Sensor magnet 46 ... Reflector plate 50 ... Drive ring 51 ... Holder, 52 ... Bearing 53 ... Anti-rotation, 54 ... Lens 70 ... Fixed lens barrel 90 ... Control unit 91 ... Position detection calculation unit 92 ... Switch control unit 93 ... Phase command conversion control unit 100, 200, 300, 350, 400 ... Magnetic drive device 210 ... Drive magnet 211 ... Yoke (211a ... Front yoke, 211b ... Rear yoke)
212: Magnet (212a: first magnet, 212b: second magnet)
215 ... Front magnet, 216 ... Back magnet 220 ... Substrate 221 ... Flat coil (221a ... Front flat coil, 221b ... Back flat coil)
222: Conductor 250: Holder (250a: Front holder, 250b: Back holder)
251 ... Guide shaft (251a ... First guide shaft, 251b ... Second guide shaft)
252 ... Fixed ring 253 ... Lens 254 ... Piezoelectric actuator 400a ... Lens shift type camera shake prevention mechanism 400b ... Sensor shift type camera shake prevention mechanism 401 ... Correction lens, 402 ... Imaging element 410 ... Frame (410x ... X axis frame, 410z ... Z axis flame)
421... Spring raising mirror 422... Focus sensor 423. Focus glass 424... Penta prism 425. Viewfinder 426. Lens barrel, 530 ... movable lens mechanism for focus 540 ... movable lens mechanism for zoom B ... magnetic flux density DC ... wiring cable H ... Hall sensor I ... optical distance measuring device LC ... optical axis center SW ... switch

Claims (8)

In an imaging device that captures an optical image incident from the optical axis direction,
A first driven body that holds a functional element and is movable in an intersecting direction intersecting the optical axis direction;
A movable first drive magnet magnetized alternately in N and S poles and arranged in the crossing direction;
A plurality of first flat coils arranged in the intersecting direction so as to face the first drive magnet;
A first position sensor for detecting a relative position between the first flat coil and the drive magnet;
A first energization control unit that switches energization to the first flat coil based on a result detected by the first position sensor;
An imaging apparatus comprising: The imaging apparatus according to claim 1, wherein the functional element is a camera shake correction optical element that corrects camera shake of the optical image, and the intersecting direction is a biaxial direction orthogonal to the optical axis direction. The imaging apparatus according to claim 1, wherein the functional element is an imaging element that converts the optical image into an electrical signal, and the intersecting direction is a biaxial direction orthogonal to the optical axis direction. The imaging device includes an optical element that moves in the optical axis direction,
A second driven body that holds an optical element and is movable in the optical axis direction;
A movable second drive magnet magnetized alternately in N and S poles and arranged side by side in the optical axis direction;
A plurality of second flat coils arranged in the optical axis direction so as to face the second drive magnet;
A second position sensor for detecting a relative position between the second flat coil and the second drive magnet;
A second energization control unit that switches energization to the second flat coil based on a result detected by the second position sensor;
The imaging apparatus according to any one of claims 1 to 3, further comprising:   The imaging apparatus according to claim 4, wherein the first flat coil is linearly arranged and the second flat coil is linearly arranged. The imaging device includes an optical element that moves in the optical axis direction,
A second driven body that holds an optical element and is movable in the optical axis direction;
A movable second drive magnet that is alternately magnetized in N and S poles and arranged side by side in a circumferential direction centered on the optical axis direction;
A plurality of second flat coils arranged in the circumferential direction facing the second drive magnet;
A second position sensor for detecting a relative position between the second flat coil and the second drive magnet;
A second energization control unit that switches energization to the second flat coil based on a result detected by the second position sensor;
The imaging apparatus according to any one of claims 1 to 3, further comprising: The first position sensor and the second position sensor are magnetic detectors;
The imaging apparatus according to any one of claims 4 to 6, further comprising a detection magnet that is disposed to face the magnetic detector and in which the magnetic flux changes uniformly. The first position sensor and the second position sensor are transmission / reception detectors,
The imaging apparatus according to claim 4, further comprising a detection reflection element that is disposed to face the light transmission / reception detector and has a uniform distance.