Lens drive device, lens device, and imaging device

Abstract

The present invention provides a lens drive device that reduces the time required for origin detection during startup and enables detection of the optical axis position of the lens holding frame without using an optical position detection means. [Solution] A lens driving device comprising: a lens holding frame that holds a lens and is movable in the optical axis direction; a drive unit for moving the lens holding frame; a first magnetic body that is rotatable integrally with the output shaft of the drive unit; a first detection unit for detecting the magnetic field generated by the first magnetic body; a driven shaft that is rotationally driven by receiving a driving force from the output shaft; a second magnetic body that is rotatable integrally with the driven shaft; and a second detection unit for detecting the magnetic field generated by the second magnetic body, wherein the first magnetic body and the second magnetic body are annular in shape and magnetized in the circumferential direction, and the first magnetic body is magnetized with more poles than the second magnetic body.

Description

Technical Field

[0001] The present invention relates to a lens driving device, a lens device, and an imaging device.

Background Art

[0002] Conventionally, a lens barrel used in an optical device such as a video camera includes a lens driving device that moves a lens in the optical axis direction in order to enable zooming and focusing. In order to control the position of the lens, a position sensor that detects the position of the lens (including the holding frame that holds the lens) is required.

[0003] In Patent Document 1, a lens driving device is proposed that detects the origin position when a moving lens passes through an origin sensor and detects the relative position of the moving lens based on the origin position. In Patent Document 2, a lens driving device is proposed that detects the absolute position of a rotating cylinder by a rotating magnetic body that rotates by rotational transmission of the rotating cylinder and a rotation angle sensor that detects the magnetic field of the magnetic body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the system for detecting the relative position from the origin shown in Patent Document 1, when the power is turned off, the position of the moving lens in the optical axis direction becomes unknown, so it is necessary to move the moving lens to the position of the origin sensor when the power is turned on (at startup), which takes time for origin detection. Furthermore, since the magnetic body shown in Patent Document 2 is an absolute position detection system with two-pole magnetization, there is a risk that the resolution is low and a detailed absolute position cannot be detected.

[0006] Therefore, the present invention aims to provide a lens driving device that reduces the time required for origin detection at startup and enables detection of the position of the lens holding frame in the optical axis direction without using an optical position detection means. [Means for solving the problem]

[0007] To achieve the above objective, a lens driving device as one aspect of the present invention comprises: a lens holding frame that holds a lens and is movable in the optical axis direction; a drive unit for moving the lens holding frame; a first magnetic body that is rotatable integrally with the output shaft of the drive unit; a first detection unit for detecting the magnetic field generated by the first magnetic body; a driven shaft that is rotationally driven by receiving a driving force from the output shaft; a second magnetic body that is rotatable integrally with the driven shaft; and a second detection unit for detecting the magnetic field generated by the second magnetic body, wherein the first magnetic body and the second magnetic body are annular in shape and magnetized in the circumferential direction, and the first magnetic body is magnetized with more poles than the second magnetic body. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a lens driving device that reduces the time required for origin detection at startup and enables detection of the position of the lens holding frame in the optical axis direction without using an optical position detection means. [Brief explanation of the drawing]

[0009] [Figure 1] This is a conceptual diagram showing the entire imaging device according to this embodiment. [Figure 2] This is a perspective view showing the entire lens drive device in the embodiment. [Figure 3] This is a perspective view showing the internal configuration of the lens drive device in the embodiment. [Figure 4] This is a perspective view showing the positional relationship between the drive unit, the first position detection unit, and the second position detection unit in the embodiment. [Figure 5]This diagram shows the configuration of the first position detection unit and the second position detection unit in the embodiment. [Figure 6] This is a graph showing the output signal and calculation signal of the second position detection unit in the embodiment. [Figure 7] This is a graph showing the output signal and calculation signal of the first position detection unit in the embodiment. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] In the following diagrams, the X-axis is taken in the direction toward the subject along the optical axis of the lens group, the Y-axis is taken in a predetermined direction in a plane perpendicular to the X-axis, and the Z-axis is taken in a direction perpendicular to the Y-axis.

[0012] <Embodiment 1> Figure 1 is a conceptual diagram showing the entire imaging device 3000 according to this embodiment. As illustrated in Figure 1, the imaging device 3000 in this embodiment is configured to have a lens barrel (lens device) 1000 and a camera body 2000. The lens barrel 1000 has multiple lenses arranged inside and a lens drive device 100 built in. Details of the lens drive device 100 shown in Figure 1 will be described later. Although not shown in Figure 1 for the sake of simplicity, the lens barrel 1000 is configured to have, for example, lenses, cam rings, guide tubes, zoom rings, electromagnetic diaphragm units, and various lens barrel groups.

[0013] Furthermore, a control board (a control unit on the lens barrel side) 110 is located inside the lens barrel 1000. The control board 110 is configured as at least one computer, including a CPU and memory. The control board 110 controls various operations (for example, drive operations) within the lens barrel 1000 by being electrically connected to various parts of the lens barrel 1000. The control board 110 is electrically connected to, for example, a flexible circuit board 12 (described later) and an electromagnetic diaphragm unit (not shown).

[0014] The lens barrel 1000 has a mount 120. The mount 120 is a component fixed to the camera body 2000, which has various components such as an image sensor 200 that captures an image of a subject through an optical element (lens). That is, the mount 120 of the lens barrel 1000 is configured to be attachable to a mount 210 provided on the camera body 2000, and by attaching it to the mount 210 provided on the camera body 2000, it can be connected to the camera body 2000 in a communicative manner. In this way, the lens barrel 1000 and the camera body 2000 having the image sensor 200 can constitute an imaging device 3000. The imaging device 3000 is configured to capture an image formed through the lens barrel 1000. Note that the imaging device 3000 may be an imaging device in which the lens barrel 1000 and the camera body 2000 are integrated.

[0015] The imaging device 200 is composed of an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Also, the camera body 2000 has a control board (control unit on the camera side) not shown in the figure. The control board not shown in the figure is configured as at least one computer including a CPU, a memory, etc., and comprehensively controls the operation of the camera body 2000. The control board not shown in the figure operates when the camera body 2000 is powered on by operating a power button not shown in the camera body 2000. Also, when the lens barrel 1000 and the camera body 2000 are electrically connected via respective mounts, the control board not shown in the figure is also electrically connected to the control board 110. Then, by the control unit not shown in the camera body 2000 transmitting and receiving control signals corresponding to operations and processes to and from the control board 110, the operations of the lens barrel 1000 may be controlled.

[0016] FIG. 2 is a perspective view showing the entirety of the lens driving device 100 according to the present embodiment. The lens driving device 100 has a fixing member composed of a fixed cylinder 1 and a fixing plate 2 that constitute the lens barrel 1000. Also, the lens driving device 100 further has a flexible substrate 12, and the flexible substrate 12 is fixed to the fixed cylinder 1. Also, the lens driving device 100 may have a control board (control means) that functions as a control unit for controlling each element of the lens driving device and is configured as at least one computer including a CPU, a memory, etc.

[0017] FIG. 3 is a diagram showing the internal configuration of the lens driving device 100. FIG. 3(A) is a perspective view seen from the subject direction on the X-axis, and FIG. 3(B) is a side view (seen along the Z-axis) seen from the Z-axis direction.

[0018] The moving lens group 3 is held by the lens holding frame 4. Then, the moving lens group 3 moves in a direction along the optical axis OA while being held by the lens holding frame 4. Incidentally, the moving lens group 3 may be of any type of zoom lens or focus lens.

[0019] The lens holding frame 4 is supported by a first guide shaft (first guide bar) 5 and a second guide shaft (second guide bar) 6. In the vicinity of the first guide shaft 5, a rack 7 is rotatably attached about an axis parallel to the X axis. The first guide shaft 5 and the second guide shaft 6 are fixed by a fixing cylinder 1 and a fixing plate 2 so as to be parallel to the optical axis OA (so as to be in the direction along the optical axis OA). Therefore, the moving direction of the lens holding frame 4 is restricted in the optical axis front-back direction (X-axis direction). That is, the lens holding frame 4 is configured to be movable only in the direction along the optical axis OA.

[0020] The rack 7 has a tooth portion that meshes with a screw 9 which is an output shaft of a stepping motor 8, and is combined with the screw 9 while being biased in the X-axis direction and about an axis parallel to the X axis by a biasing spring 10. The screw 9 is rotatably supported at both ends by a fixing member 11.

[0021] By applying a current to the stepping motor 8 via a flexible substrate 12, an electromagnetic force is generated, and the screw (output shaft) 9 rotates. When the screw 9 rotates, the lens holding frame 4 obtains a driving force via the rack 7 and moves in the X-axis direction while being guided by the first guide shaft 5 and the second guide shaft 6. Thus, the stepping motor 8 functions as a driving unit that moves the lens holding frame 4 in the direction of the optical axis OA.

[0022] Hereinafter, referring to FIGS. 4 and 5, the configurations of the first position detection unit 13 (relative position sensor unit) and the second position detection unit 14 (absolute position sensor unit) will be described.

[0023] FIG. 4 is a diagram showing the positional relationship among the stepping motor 8, the first position detection unit 13, and the second position detection unit 14. FIG. 4(A) is a perspective view when viewed from the Z-axis direction. FIG. 4(B) is a perspective view when the flexible substrate

[0024] The first position detection unit 13 includes a first sensor magnet (first magnetic material) 15 and a first magnetic sensor (first detection unit) 16 positioned near the outer circumferential surface of the first sensor magnet 15. In other words, the first magnetic sensor 16 is positioned within the lens drive device 100 at a distance that does not contact the first sensor magnet 15, and at a position opposite to it.

[0025] The first sensor magnet 15 is a magnetic material with a ring shape and multi-pole magnetization of N and S poles in the circumferential direction. While it is preferable for the first sensor magnet 15 to be configured with 10-pole magnetization, as shown in Figure 5, for determining the position of the lens holding frame 4 in the optical axis direction (described later), it is not limited to this configuration. For example, the magnetization can be increased beyond the case shown in Figure 5 (10-pole magnetization). Increasing the magnetization improves the detection resolution compared to not increasing the magnetization. The first sensor magnet 15 is rotatably mounted integrally with the screw 9. In other words, the first sensor magnet 15 rotates integrally with the screw 9, which is the output shaft.

[0026] The first magnetic sensor 16 is a magnetoresistive element that detects the magnetic field generated by the first sensor magnet 15 without contacting the first sensor magnet 15. In other words, the first magnetic sensor 16 detects the magnetic field generated by the first sensor magnet 15, which is the first magnetic material. That is, the first magnetic sensor 16 is positioned within the lens drive device 100 at a distance that does not contact the first sensor magnet 15, but is at a distance that allows it to detect the magnetic field generated by the first sensor magnet 16.

[0027] The first magnetic sensor 16 is mounted on a flexible substrate 12 and held by a sensor holding member 17 via the flexible substrate 12. The flexible substrate 12 and the sensor holding member 17 are fixed together, for example, by adhesive means (adhesive or adhesive tape). The first magnetic sensor 16 includes two magnetic detection units, a magnetic detection unit 16a (first magnetic detection unit) and a magnetic detection unit 16b (second magnetic detection unit), which detect the magnetic field in the Z-axis direction of the magnetic field generated by the first sensor magnet 15.

[0028] The second position detection unit 14 includes a second sensor magnet (second magnetic material) 18 and a second magnetic sensor (second detection unit) 19 positioned near the outer circumferential surface of the second sensor magnet 18. In other words, the second magnetic sensor 19 is positioned within the lens drive device 100 at a distance that does not contact the second sensor magnet 18, and at a position opposite to it.

[0029] The second sensor magnet 18 is a magnetic material with a ring shape and two poles, an N pole and a S pole, magnetized in the circumferential direction. By using two-pole magnetization, a sine wave can be completed as one period from the start point to the end point of the stroke. Thus, in this embodiment, the first sensor magnet 15 is configured to be magnetized with more poles than the second sensor magnet 18.

[0030] The second sensor magnet 18 is integrally and rotatably mounted on the driven shaft 21. The driven shaft 21 is rotationally driven by the driving force from the screw 9. Specifically, the rotational force (driving force) from the screw 9 is transmitted to the reduction mechanism 20, and then the rotational force from the screw 9, which has been reduced by the reduction mechanism 20, is transmitted to the driven shaft 21, causing it to rotate.

[0031] The second magnetic sensor 19 is a magnetoresistive element that detects the magnetic field generated by the second sensor magnet 18 without contact with the second sensor magnet 18. In other words, the second magnetic sensor 19 detects the magnetic field generated by the second sensor magnet 18, which is the second magnetic material. That is, the second magnetic sensor 19 is positioned within the lens drive device 100 at a distance that does not contact the second sensor magnet 18, but is at a distance that allows it to detect the magnetic field generated by the second sensor magnet 18.

[0032] The second magnetic sensor 19 is mounted on a flexible substrate 12 and held by a sensor holding member 17 via the flexible substrate 12. The flexible substrate 12 and the sensor holding member 17 are fixed together, for example, by adhesive means (adhesive or adhesive tape). The second magnetic sensor 19 includes two magnetic detection units, a magnetic detection unit 19a (third magnetic detection unit) and a magnetic detection unit 19b (fourth magnetic detection unit), which detect the magnetic field in the Z-axis direction from the magnetic field generated by the second sensor magnet 18.

[0033] As shown in Figure 5, the first magnetic sensor 16 of the first position detection unit 13 and the second magnetic sensor 19 of the second position detection unit 14 are arranged to detect the magnetic field in the Z direction emitted by their respective sensor magnets, but the arrangement is not limited to this position. That is, the first magnetic sensor 16 can be placed in the lens drive device 100 at a distance that does not contact the first sensor magnet 15, but at a distance that allows it to detect the magnetic field generated by the first sensor magnet 16 at an opposing position. Similarly, the second magnetic sensor 19 can be placed in the lens drive device 100 at a distance that does not contact the second sensor magnet 18, but at a distance that allows it to detect the magnetic field generated by the second sensor magnet 18 at an opposing position.

[0034] The reduction mechanism 20 is configured to include a first reduction gear 22 and a second reduction gear 23. The first reduction gear 22 is integrally rotatably mounted on the screw 9. The second reduction gear 23 is integrally rotatably mounted on the driven shaft 21. The sensor holding member 17 holds the first magnetic sensor 16 and the second magnetic sensor 19 via the flexible substrate 12 and is fastened to the fixing member 11 by screws or other components.

[0035] The principle for detecting the absolute position of the lens holding frame 4 using the first position detection unit 13 (relative position sensor unit) and the second position detection unit 14 (absolute position sensor unit) will be explained below with reference to Figures 6 and 7. In this embodiment, the absolute position of the lens holding frame 4 can be detected without driving the lens holding frame 4 immediately after power-on (startup).

[0036] Figure 6 shows an example of the output of the second position detection unit 14 (absolute position sensor unit). Figure 6(A) is a graph showing the output signal when the driven shaft 21 is rotating at a constant speed, with the horizontal axis representing time and the vertical axis representing the magnetic field strength in the Z-axis direction. Figure 6(B) is a graph showing the higher-level signal calculated from the output signal of Figure 6(A), with the horizontal axis representing the distance in the X-axis direction and the vertical axis representing the rotation angle of the driven shaft 21.

[0037] In Figure 6, the output signal 501 of the magnetic detection unit 19a of the second magnetic sensor 19 is shown by a solid line, and the output signal 502 of the magnetic detection unit 19b is shown by a dashed line. Output signals 501 and 502 are two sinusoidal signals with a 90-degree phase difference. One period of the sinusoidal signal corresponds to the total movement of the lens holding frame 4 in the X-axis direction by the reduction mechanism 20. By performing an inverse tangent transformation on the two sinusoidal signals 501 and 502, a linear higher-order signal (second output signal) 503 is obtained, which monotonically increases with a constant slope between -π and +π radians.

[0038] Figure 7 shows an example of the output of the first position detection unit 13 (relative position sensor unit). Figure 7(A) is a graph showing the output signal when the screw 9 is rotating at a constant speed, with the horizontal axis representing time and the vertical axis representing the strength of the magnetic field in the Z-axis direction. Figure 7(B) is a graph showing the lower-level signals calculated from the output signal of Figure 7(A), with the horizontal axis representing the distance in the X-axis direction and the vertical axis representing the rotation angle of the screw 9.

[0039] In Figure 7, the output signal 601 of the magnetic detection unit 16a of the first magnetic sensor 16 is shown by a solid line, and the output signal 602 of the magnetic detection unit 16b is shown by a dashed line. Output signals 601 and 602 are two sinusoidal signals with a 90-degree phase difference. The number of periods of the sinusoidal signals corresponds to the number of rotations of the screw 9 when the total amount of movement of the lens holding frame 4 in the X-axis direction is reached. By performing an inverse tangent transformation on the two sinusoidal signals 601 and 602, a lower signal (first output signal) 603 is obtained, which is a periodic sawtooth waveform that repeats between -π and +π radians.

[0040] In this embodiment, a higher-level signal is obtained based on the output signal output by the magnetic detection unit 19a and the output signal output by the magnetic detection unit 19b, and a lower-level signal is obtained based on the output signal output by the magnetic detection unit 16a and the output signal output by the magnetic detection unit 16b.

[0041] The absolute position of the lens holding frame 4 is determined by performing signal synchronization processing on the upper signal 503 and the lower signal 603. In other words, the absolute position of the lens holding frame 4 is determined by detecting its position in the optical axis direction OA based on the first output signal output by the first magnetic sensor 16 and the second output signal output by the second magnetic sensor 19. By determining the absolute position of the lens holding frame 4, the absolute position of the lens held by the lens holding frame 4 can also be determined. In this signal synchronization processing, the number of the detected position within the repeating signal of the lower signal 603 is determined based on the output value of the upper signal 503.

[0042] As described above, according to this embodiment, the rotation angle of the screw 9 and the driven shaft 21 can be calculated based on the output signals of the first position detection unit 13 and the second position detection unit 14, and the absolute position of the lens holding frame 4 can be determined by signal synchronization processing of the upper signal 503 and the lower signal 603. Furthermore, in this embodiment, since the lens holding frame 4 is not driven immediately after the power is turned on, the detailed absolute position of the lens holding frame 4 can be detected without the time required for origin detection after startup.

[0043] The above-mentioned processes, such as output signal detection, signal calculation, and signal synchronization, are performed by the control board in the lens drive device 100. In other words, the control board in the lens drive device 100 can detect the optical axis position of the lens holding frame 4 and determine the absolute position of the lens holding frame 4. Alternatively, the above-mentioned processes, such as output signal detection, signal calculation, and signal synchronization, may be performed by a control board 110 located in the lens barrel 1000 or a control board located in the camera body 2000.

[0044] As described above, the lens drive device 100 of this embodiment does not require time for origin detection when the imaging device 3000 is powered on, and it is possible to detect the precise absolute position of the lens holding frame 4. Furthermore, since optical position detection means are not used, the effect of stray light not being detected by the image sensor is also achieved.

[0045] In this embodiment, the reduction mechanism 20 is of the gear type, but it is not limited to this. For example, the reduction mechanism 20 may be configured as a belt type.

[0046] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence. Furthermore, the above embodiments may be implemented in combination.

[0047] This embodiment includes the following configuration.

[0048] (Composition 1) A lens holder frame that holds the lens and is movable in the optical axis direction, A drive unit for moving the lens holding frame, A first magnetic body that can rotate integrally with the output shaft of the drive unit, A first detection unit for detecting the magnetic field generated by the first magnetic material, A driven shaft that receives driving force from the output shaft and is rotationally driven, A second magnetic body that can rotate integrally with the driven shaft, The system comprises a second detection unit for detecting the magnetic field generated by the second magnetic material, The first magnetic material and the second magnetic material are magnetized in the circumferential direction in an annular shape. The first magnetic material is magnetized with more poles than the second magnetic material. A lens drive device characterized by the following features.

[0049] (Configuration 2) The lens drive device according to configuration 1, characterized in that it has a reduction mechanism that reduces the rotation from the output shaft and transmits it to the driven shaft.

[0050] (Composition 3) The reduction mechanism includes a first reduction gear and a second reduction gear, The lens drive device according to configuration 2, characterized in that the first reduction gear is mounted integrally and rotatably with the output shaft, and the second reduction gear is mounted integrally and rotatably with the driven shaft.

[0051] (Composition 4) A lens driving device according to any one of configurations 1 to 3, characterized in that it has a control means for detecting the optical axis position of the lens holding frame based on a first output signal output by the first detection unit and a second output signal output by the second detection unit.

[0052] (Composition 5) The lens driving device according to configuration 4, characterized in that the control means calculates the rotation angle of the output shaft and the driven shaft based on the first output signal and the second output signal of the second detection unit, and detects the optical axis position of the lens holding frame by performing signal synchronization processing between the upper and lower signals.

[0053] (Composition 6) The first detection unit includes a first magnetic detection unit and a second magnetic detection unit. The second detection unit includes a third magnetic detection unit and a fourth magnetic detection unit. A lens driving device according to any one of configurations 1 to 5, characterized in that it has control means for acquiring a lower signal based on the output signal output by the first magnetic detection unit and the output signal output by the second magnetic detection unit, and for acquiring a higher signal based on the output signal output by the third magnetic detection unit and the output signal output by the fourth magnetic detection unit.

[0054] (Composition 7) The lens driving device according to configuration 5, characterized in that the control means determines the optical axis direction position of the lens holding frame by performing signal synchronization processing on the upper signal and the lower signal.

[0055] (Composition 8) The lens driving device according to any one of claims 1 to 7, characterized in that the second magnetic material is a magnetic material with a ring shape and two poles, an N pole and a S pole, magnetized in the circumferential direction.

[0056] (Composition 9) Lens and, A lens drive device having one of the configurations 1 to 8, A lens device characterized by the following features.

[0057] (Composition 10) Image sensor and The lens device described in configuration 9, An imaging device characterized by the following features. [Explanation of Symbols]

[0058] 4. Lens holding frame 8 Stepping motors 9 Screw 15. First Sensor Magnet 16. First magnetic sensor 18. Second Sensor Magnet 19. Second magnetic sensor 20 Reducer 21 Driven axis 100 Lens drive device 503 Higher signal 603 Lower signal

Claims

1. A lens holder frame that holds the lens and is movable in the optical axis direction, A drive unit for moving the lens holding frame, A first magnetic body that can rotate integrally with the output shaft of the drive unit, A first detection unit for detecting the magnetic field generated by the first magnetic material, A driven shaft that receives driving force from the output shaft and is rotationally driven, A second magnetic body that can rotate integrally with the driven shaft, The system comprises a second detection unit for detecting the magnetic field generated by the second magnetic material, The first magnetic material and the second magnetic material are magnetized in the circumferential direction in an annular shape. The first magnetic material is magnetized with more poles than the second magnetic material. A lens drive device characterized by the following features.

2. The lens driving device according to claim 1, characterized in that it has a reduction mechanism that reduces the rotation from the output shaft and transmits it to the driven shaft.

3. The reduction mechanism includes a first reduction gear and a second reduction gear. The lens drive device according to claim 2, characterized in that the first reduction gear is mounted integrally and rotatably with the output shaft, and the second reduction gear is mounted integrally and rotatably with the driven shaft.

4. The lens driving device according to claim 1, further comprising control means for detecting the optical axis position of the lens holding frame based on a first output signal output by the first detection unit and a second output signal output by the second detection unit.

5. The lens driving device according to claim 4, characterized in that the control means calculates the rotation angle of the output shaft and the driven shaft based on the first output signal and the second output signal of the second detection unit, and detects the optical axis position of the lens holding frame by performing signal synchronization processing between the upper and lower signals.

6. The first detection unit includes a first magnetic detection unit and a second magnetic detection unit. The second detection unit includes a third magnetic detection unit and a fourth magnetic detection unit. The lens driving device according to claim 1, characterized in that it has control means for acquiring a lower signal based on the output signal output by the first magnetic detection unit and the output signal output by the second magnetic detection unit, and acquiring a higher signal based on the output signal output by the third magnetic detection unit and the output signal output by the fourth magnetic detection unit.

7. The lens driving device according to claim 5, characterized in that the control means determines the optical axis direction position of the lens holding frame by performing signal synchronization processing on the upper-level signal and the lower-level signal.

8. The lens driving device according to claim 1, characterized in that the second magnetic material is a magnetic material with a ring shape and two poles, an N pole and a S pole, magnetized in the circumferential direction.

9. Lens and, A lens driving device according to any one of claims 1 to 8, A lens device characterized by the following features.

10. Image sensor and The lens device according to claim 9, An imaging device characterized by the following features.

Images