JP2011112709A - Lens drive device, autofocus camera, and cellular phone having built-in camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device, an autofocus camera, and a cellular phone having a built-in camera, moving a lens support for focusing and moving for camera shake correction, and achieving compactness, with simple structures. <P>SOLUTION: First annular coils 19a-19d are provided on the outer peripheral surface of the lens support 5. Second annular coils 16a-16d are arranged in the circumferential direction of the lens support 5 with an interval of 90 degrees. A first magnet part 17 is arranged so as to face the first annular coils 19. A second magnet part 18 is arranged inside the annulus of each second annular coil 16a-16d. A third magnet part 27 is arranged outside the annulus of the second annular coils 16a-16d. When the lens support 5 is moved in the optical axis direction, a current flows in the first annular coils 19a-19d, and when the lens support 5 is moved in the X-Y direction, a current flows in the predetermined second annular coil 16a-16d. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens driving device, an autofocus camera, and a camera-equipped mobile phone.

  In Patent Document 1, in the optical pickup actuator, a first annular coil and a second annular coil are provided on the outer peripheral surface of the lens support member with a spacing of 90 degrees in the circumferential direction. By placing a magnet facing the annular coil and energizing the annular coil, the lens support is tilted to the optical axis (focus direction), tilted to the optical axis (tilt correction direction), and track direction (X direction). Is disclosed.

  On the other hand, in a small camera mounted on a mobile phone or the like, the lens support is only moved in the focus direction, and is moved in the tilt correction direction or moved in the XY direction for camera shake correction. In this case, the entire lens driving device that moves the lens support in the focus direction is moved by a motor for tilt correction, a motor for driving in the X direction, and a motor for driving in the Y direction.

JP 2002-373435 A

  By the way, in a lens driving device for a small camera, there is no conventional lens support that moves the lens support in the optical axis direction (focus movement) and the XY direction (camera shake correction).

  Further, even if the technique of Patent Document 1 can be used for the movement of the lens support in the focus direction, the technique of Patent Document 1 can only move in the X direction, and can correct camera shake (in the XY direction). Cannot be moved).

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens driving device, an autofocus camera, and a camera-equipped mobile phone that can move the lens support with focus and camera shake correction and can be downsized with a simple configuration.

  According to the first aspect of the present invention, a lens support that supports the lens on the inner periphery, a first annular coil disposed on the outer periphery of the lens support, and an interval of 90 degrees in the circumferential direction on the outer periphery of the lens support. A plurality of second annular coils arranged with a gap therebetween, a base for movably supporting the lens support, a first magnet part, a second magnet part and a third magnet part fixed to the base, and energization of each coil A first magnet part is arranged facing the first annular coil, a second magnet part is arranged inside the ring of each second annular coil, and the third magnet part is the second magnet part. Arranged outside the ring of the annular coil, the controller sends current to the first annular coil when moving the lens support in the optical axis direction, and moves the lens support in the XY direction perpendicular to the optical axis. When the electric power is applied to the predetermined second annular coil. A lens driving device, characterized in that flow.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first annular coil is plural, and is arranged on the outer peripheral surface of the lens support member at equal intervals in the circumferential direction. The control unit is arranged at a position not overlapping with the first annular coil, and the control unit causes a current to flow through the predetermined first annular coil when the lens support is moved in the optical axis direction and when the lens support is inclined with respect to the optical axis. It is characterized by making different.

  According to a third aspect of the present invention, in the second aspect of the invention, an annular yoke surrounding the lens support is provided, and the first to third magnet portions are arranged on the inner peripheral surface of the yoke. And

  According to a fourth aspect of the present invention, there is provided an auto comprising the lens driving device according to any one of the first to third aspects, and an image sensor provided on the image forming side of the lens of the lens support. It is a focus camera.

  A fifth aspect of the present invention is a camera-equipped mobile phone in which the autofocus camera according to the fourth aspect is mounted.

  According to the first aspect of the present invention, the focus movement is performed by energizing the first annular coil to move the lens support in the optical axis direction, and camera shake correction is provided at intervals of 90 degrees in the circumferential direction. By energizing the two second annular coils, the lens support is moved in the XY direction. Thereby, focus movement and camera shake correction can be performed on the lens support.

  The first and second annular coils are arranged on the outer peripheral surface of the lens support, the first magnet part facing the first annular coil on the base, the second magnet part arranged inside and outside the ring of the second annular coil, and Since only the third magnet portion is provided, the size can be reduced with a simple configuration.

  Since the second annular coil is provided with second and third magnet portions inside and outside the ring, and the coil portion of the second annular coil is sandwiched between the second and third magnet portions, the magnetic field acting on the second annular coil Can be made a magnetic field closed by the second and third magnet portions to increase the magnetic flux density. Therefore, the second annular coil can be reduced or the current required for driving can be reduced to compensate for camera shake (XY correction) of the lens support.

  According to the second aspect of the present invention, the effects described in the first aspect can be achieved, and the current flowing through the predetermined first annular coil can be varied to tilt the optical axis of the lens support so as to correct the tilt. Can do.

  According to the invention described in claim 3, the function and effect described in claim 2 are achieved. Moreover, since the yoke is annular and each magnet part is arranged on the inner peripheral surface, the magnetic field strength in each magnet part can be increased, and the yoke for each magnet part can be used in common, and the number of parts can be reduced. Less.

  According to invention of Claim 4, the auto-focus camera which has an effect as described in any one of Claims 1-3 can be provided.

  According to the invention described in claim 5, it is possible to provide a camera-equipped mobile phone having the function and effect described in claim 4.

It is sectional drawing which cut | disconnected the lens drive device which concerns on this Embodiment horizontally. It is a perspective view which shows the state which mounted | wore the lens support body which concerns on this Embodiment with the 1st and 2nd annular coil. It is a perspective view which shows the inner side part of a yoke in the lens drive device which concerns on this Embodiment. It is a side view of the inner part of the yoke shown in FIG. It is a disassembled perspective view of the lens drive device concerning this embodiment. It is a block diagram which shows the relationship between a lens support body and a drive part in the lens drive device which concerns on this Embodiment. It is a block diagram which shows the relationship between the image sensor which concerns on this Embodiment, and a control part. It is a figure explaining the effect | action of the lens drive device which concerns on this Embodiment. It is a perspective view which shows the external appearance of the lens drive device which concerns on this Embodiment.

  Embodiments of the present invention will be described below in detail with reference to FIGS. A lens driving device 1 according to the present embodiment is a lens driving device for an autofocus camera incorporated in a mobile phone.

  As shown in FIG. 5, the lens driving device 1 includes an annular yoke 3, a lens support 5, a frame 7 and a front spring 9 disposed on the front side of the yoke 3 in the optical axis direction, and a rear side of the yoke 3. A base 8 and a rear spring 11 are provided, and a front spacer 14 and a front flexible insulating sheet 13 are disposed between the front spring 9 and the yoke 3, and the rear spring 11 and the yoke 3. A rear spacer 15 and a rear flexible insulating sheet 12 are disposed between the two.

  As shown in FIGS. 1 and 5, the yoke 3 has a substantially rectangular tube shape, and the first magnet portion 17 is fixed to the inner circumferential side of each of the four angles of the yoke 3. As shown in FIG. 5, the magnet unit 17 is composed of two magnets, a front magnet 17a and a rear magnet 17b. The yoke 3 is fixed between the base 8 and the frame 7.

  Each of the front magnet 17a and the rear magnet 17b has a substantially triangular plane when viewed from the front side, and an inner peripheral side formed in an arc shape along the outer periphery of the lens support 5. The front magnet 17a and the rear magnet 17b have different inner peripheral magnetic poles. For example, the front magnet has a surface on the lens support side as an N pole, and the rear magnet has an S pole.

  A second magnet portion 18 and a third magnet 27 are fixed to the inner circumferences of the four side surfaces of the rectangular cylindrical yoke 3, respectively. The second magnet portion 18 is inserted into a rectangular hole 20 formed on each side surface of the yoke from the outer peripheral side and fixed to the yoke 3.

  The 2nd magnet part 18 protrudes toward the inner peripheral side of the yoke 3, and as shown in FIG. 3, the magnetic pole part is arrange | positioned inside each ring of 2nd cyclic | annular coils 16a-16d. The second magnet unit 18 has different magnetic poles on the front and rear sides. For example, the front side is an N pole and the rear side is an S pole.

  The third magnet portion 27 is fixed to the inner peripheral surface of the protruding portion 3 a (see FIGS. 5 and 9) that protrudes forward on each side surface of the yoke 3, and the inner periphery on the front side of the second magnet portion 18. Projecting toward. As shown in FIG. 3, the third magnet unit 27 has a different magnetic pole from the second magnet unit 18 on the side facing the second magnet unit 18. For example, in the present embodiment, the side (rear side) facing the second magnet unit 18 is an S pole, and the opposite side (front side) is an N pole.

  As shown in FIGS. 2 and 5, the lens support 5 has a substantially cylindrical shape, and a lens (not shown) is fixed to the inner peripheral side thereof. Four first annular coils 19a, 19b, 19c, and 19d provided at equal intervals in the circumferential direction are provided on the outer peripheral surface of the lens support 5. The four first annular coils 19a, 19b, 19c, 19d are attached to the outer peripheral surface of the lens support 5 at equal intervals in the circumferential direction, and each form a rectangular ring when viewed from the side. 19 d is positioned by being inserted into the protrusion 22 of the lens support 5 in the hollow of the ring.

  The front portion 21 of each of the first annular coils 19a to 19d faces the front magnet 17a of the first magnet portion 17, and the rear portion 23 faces the rear magnet 17b.

  Between the adjacent first annular coils 19a to 19d, second annular coils 16a, 16b, 16c and 16d are arranged. Adjacent second annular coils are disposed at an angle of approximately 90 degrees to each other. Each of the second annular coils 16a to 16d has a rectangular shape when viewed from the side, and a second magnet portion 18 is inserted inside the rectangular ring as shown in FIGS. .

  As shown in FIGS. 3 and 4, in each of the second annular coils 16a to 16d, the front portion 24 is sandwiched between the second magnet portion 18 and the third magnet portion 27, and the front portion 24 is It is arranged in a magnetic field generated between the two magnet part 18 and the third magnet part 27. A closed magnetic field is formed between the second magnet unit 18 and the third magnet unit 27, and the magnetic flux density is further increased by the yoke 3.

  As shown in FIG. 6, the first annular coils 19 a to 19 d are connected to the Z-θ driving unit 32, and the second annular coils 16 to 16 d are connected to the XY driving unit 33. A current of a predetermined value is energized from the drive units 32 and 33, respectively. Each of the drive units 32 and 33 receives a control signal from the control unit 25 described later, and causes a predetermined value of current to flow through each coil. As shown in FIG. 8, Z is the optical axis direction, θ is the inclination with respect to the optical axis, and the X and Y directions mean a plane (two-dimensional) perpendicular to the optical axis.

  In the present embodiment, current flows individually through the first annular coils 19a to 19d, but the second annular coils 16a and 16c and 16b and 16d are connected in series, and the X direction and Both are driven in the same direction by two annular coils 16a and 16c, 16b and 16d in the Y direction.

  For example, in response to the drive signal from the control unit 25, the Z-θ drive unit 32 energizes the first annular coils 19 a to 19 d from the focus unit 35 when moving the lens support 5 to the focus position. When the current A is supplied and the tilt correction unit 37 performs the tilt correction, the current B is supplied to the corresponding first annular coils 19a, 19b, 19c, and 19d. In FIG. 6, symbols A and B indicate the direction and magnitude of the thrust generated based on the flowed current.

  Similarly, in the case of correcting the camera shake, the XY drive unit 33 causes the current E to flow through the second annular coils 16a and 16c to move the lens support in the X direction, and the second annular coils 16b and 16d are moved to the second annular coils 16b and 16d. The lens support is moved in the Y direction by passing an electric current F. Accordingly, the camera support is corrected by moving the lens support in the XY direction.

  Next, the configuration of the control unit 25 will be described with reference to FIGS. 7 and 8. A set of X direction sensors 38a and 38b provided in the Y direction of the image sensor 31 on the outer periphery of the image sensor 31 in the Y direction of the image sensor 31, and a set of Y direction sensors opposed in the X direction. 39 a and 39 b are connected to the control unit 25. The control unit 25 includes a focus / tilt control unit 41 and a camera shake control unit 43, and includes a contrast storage unit 45, a contrast comparison unit 46, and a calculation unit 47, respectively.

  The contrast comparison unit 46 compares the current contrast peak (high frequency component) with the contrast peak stored with time lag, and the calculation unit 47 stores the current contrast peak position and the storage unit. The amount of deviation from the contrast peak position is calculated, and a drive signal is issued to each of the corresponding drive units 32 and 33.

  Specifically, in the focus / tilt calculation unit 41, when the lens support 5 is moved to the focus position, the optical axis direction (Z direction) is set so as to be the maximum peak position at the center e (see FIG. 7). As shown in FIG. 8, when the focal point (contrast peak) is shifted from the center e1 and is at e2, as shown in FIG. 8, a predetermined first annular shape is formed so that the lens support 5 is inclined by a predetermined amount. A control signal is issued to the Z-θ drive unit 32 so that a predetermined current flows through the coils 19a to 19d.

  Although FIG. 8 schematically shows one lens, in the present embodiment, the lens support 5 holds a lens group composed of a plurality of lenses, and the principal point of the lens group is usually It is set from the front side of the lens group. Thereby, the focus position in the image sensor 31 is shifted due to the inclination of the lens support 5.

  On the other hand, in the camera shake control unit (camera shake correction unit) 43, the comparison unit 46 compares the contrast peak position stored in the storage unit 45 and the current contrast peak position in each of the two X direction sensors 38a and 38b. Then, the amount of deviation is calculated by the calculation unit 47, and an average of the two X direction sensors 38a and 38b is calculated, and a predetermined amount is applied to the second annular coils 16a and 16c so as to correct the amount of deviation in the X direction. A drive control signal for causing the current E (see FIG. 6) to flow is issued to the XY drive unit 33.

  Similarly, for the two Y-direction sensors 39a and 39b, the same calculation is performed from the comparison of the contrast, and the XY drive is performed so that a predetermined current F (see FIG. 6) flows through the second annular coils 16b and 16d. A control signal is issued to the unit 33.

  As shown in FIG. 5, the front spring 9 has a flat plate shape in a natural state before assembly, and is arranged on the outer peripheral side portion 9 a having a rectangular shape in plan view, and on the inner periphery of the outer peripheral side portion 9 a, and in an arc shape in plan view The inner peripheral side portion 9b and the respective arm portions 9c connecting the outer peripheral side portion 9a and the inner peripheral side portion 9b.

  Similarly, the rear spring 11 has a flat plate-like natural state before assembly, and is arranged on the outer peripheral side portion 11a having a rectangular shape in plan view, and on the inner periphery of the outer peripheral side portion 11a. It is comprised by the side part 11b and each arm part 11c which connects the outer peripheral side part 11a and the inner peripheral side part 11b.

  An outer peripheral side portion 9 a of the front spring 9 is sandwiched between the frame 7 and the front spacer 14, and an inner peripheral side portion 9 b is fixed to the front end of the lens support 5 via a flexible insulating sheet 13. The outer peripheral side portion 11 a of the rear spring 11 is sandwiched between the base 8 and the rear spacer 15, and the inner peripheral side portion 11 b is fixed to the rear end of the lens support 5 via the flexible insulating sheet 12. Yes. Thus, the lens support 5 is supported by the front spring 9 and the rear spring 11 so as to be movable in the front-rear direction (Z direction) and the XY direction.

  When the lens support 5 moves forward, the lens support 5 suspends the resultant force of the urging force of the front spring 9 and the rear spring 11 and the electromagnetic force generated between the annular coil 16 and the magnet 17. Stop at position.

  Next, assembly, operation, and effects of the lens driving device 1 according to the embodiment of the present invention will be described.

  As shown in FIG. 5, the lens driving device 1 is assembled by fixing the rear spring 11, the rear spacer 15, the first annular coils 19 a to 19 d and the second annular coils 16 a to 16 d to the outer surface of the base 8. The lens support 5 (see FIG. 2), four first magnets 17 in the inner corner, the yoke 3 with the third magnet 27 fixed on the inner peripheral side of the four side protrusions 3a, the front spacer 14, After the front spring 9 and the frame 7 are assembled in this order, the second magnet portion 18 is inserted and fixed in the holes 20 formed on each side surface of the yoke 3.

  The first annular coils 19a to 19d each have an input end and an output end connected to the Z-θ drive unit 32, and the second annular coils 16a to 16d are connected to the opposing coils 16a and 16c and 16b and 16d in series. Thereafter, the input end and the output end are connected to the XY drive 33.

  As shown in FIGS. 7 and 8, the driving of the lens driving device 1 according to the present embodiment causes the high-frequency component (contrast) peak received by the focus / tilt control unit 41 from the image sensor 31 in the control unit 25. While comparing, the lens support 5 is linearly moved in the Z direction to the in-focus position e1 (see FIG. 6).

  When the lens support 5 is linearly moved in the Z direction, the electromagnetic force generated between the focus / tilt control unit 41 and the magnet 17 generated by passing the current value A through the first annular coils 19a to 19d Then, it stops at a position where the resultant force of the urging force of the front spring 9 and the rear spring 11 is suspended.

  On the other hand, as shown in FIG. 8, when the optical axis is tilted (deviation) (e2), it is necessary to tilt the lens support 5 in order to correct the optical axis. In this case, the focus / tilt control unit 41 compares the contrast peaks with the comparison unit 46, calculates the amount of positional deviation between e1 and e2 with the calculation unit 47, and issues a drive signal to the Z-θ drive unit 32. . As shown in FIG. 6, the Z-θ drive unit 32 causes a current B to flow through a predetermined annular coil (one, two, or three) of the first annular coils 19a, 19b, 19c, and 19d. Thus, the posture (inclination) of the lens support 5 is controlled to correct the inclination θ of the optical axis.

  Next, the control unit 25 performs XY control of the lens support 5 with the camera shake correction 43. The camera shake correction unit 43 calculates the contrast peak in the X direction by the X direction sensors 38a and 38b by comparing the contrast peak position stored in the storage unit 45 with a time lag from the current in the comparison unit 46. The shift amount is detected by the unit 47, the average value of the shift amounts of the peak positions in the two X-direction sensors 38a and 38b is calculated, and a drive signal is issued to the XY drive unit 33. The XY drive unit 33 energizes the second annular coils 16a and 16c in the X direction based on the drive signal from the camera shake correction unit 43 to move the lens support 5 in the X direction.

  Similarly, in the Y direction, the camera shake correction unit 43 compares the contrast peak position stored in the Y direction with respect to the current peak with respect to the contrast peak in the Y direction by the Y direction sensors 39a and 39b. Is detected, the average value of the deviation amounts of the peak positions in the two Y-direction sensors 38a, 38b is calculated, and a drive signal is issued to the XY drive unit 33. Based on the drive signal from the camera shake correction unit 43, the XY drive unit 33 energizes the second annular coils 16b and 16d in the Y direction to move the lens support 5 in the Y direction.

  When the lens support 5 is moved in the optical axis direction (Z direction), in the first annular coils 19a to 19d, the front portion 21 (see FIGS. 5 and 6) and the rear portion 23 (see FIGS. 5 and 6). However, since the magnetic poles of the front magnet 17a facing the front portion 21 and the rear magnet 17b facing the rear portion 23 are different, the thrust in the same direction is generated. Can get a big thrust.

  The inclination of the optical axis of the lens support 5 may be corrected after the lens support 5 has been moved to a predetermined position, or when the lens support 5 is moved, the tilt is controlled (corresponding second). The current A or the current A + B may be simultaneously supplied to the one annular coils 19a to 19d).

  According to the present embodiment, the lens support 5 can be moved in focus (movement in the Z direction), tilt correction movement (θ correction), and camera shake correction (movement in the XY direction).

  The first annular coils 19a to 19d and the second annular coils 16a to 16d are arranged on the outer peripheral surface of the lens support 5, and the first magnet portion 17 facing the first annular coils 19a to 19d is disposed on the yoke 3, and the second Since only the second magnet portion 18 and the third magnet portion 27 disposed inside and outside the rings of the annular coils 16a to 16d are provided, the size can be reduced with a simple configuration.

  The second annular coils 16a to 16d are provided with a second magnet portion 18 and a third magnet portion 27 inside and outside the ring, and the second and third magnet portions 18 and 27 are front sides of the second annular coils 16a to 16d. Since the portion 24 is sandwiched, the magnetic field acting on the second annular coils 16a to 16d can be made a magnetic field closed by the second magnet part 18 and the third magnet part 27, and the magnetic flux density can be increased. Therefore, when a predetermined driving force is obtained, the second annular coils 16a to 16d can be made smaller or the current required for driving can be made smaller.

  Since the lens support 5 can be moved so as to be tilt-corrected or shake-corrected, the accuracy and assembly accuracy of the lens support and the components that hold the lens support movably can be lowered, as well as component defects and the lens driving device 1. Defects can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the detection of the optical axis inclination e2 (see FIG. 8) may be detected by an acceleration sensor or may be detected by a gyro sensor. Further, the camera shake detection may be detected by a gyro sensor.

  Although the 3rd magnet part 27 has arrange | positioned so that the front side part 24 of 2nd annular coils 16a-16d may be pinched | interposed between the 2nd magnets 18, it is not restricted to this, The rear side part of 2nd annular coils 16a-16d 29 (see FIG. 3) may be disposed on the rear side of the second annular coils 16 a to 16 d so as to be sandwiched between the second magnet 18.

  In the above-described embodiment, two second annular coils 16a to 16d and two second magnets 18 are provided in the X direction and the Y direction, but only one in the X direction and one in the Y direction. There may be.

  Two X direction sensors 38a and 38b and two Y direction sensors 39a and 39b are provided opposite to each other to obtain an average value. However, one X direction sensor 38a and one Y direction sensor 39a are provided for each of the X direction and the Y direction. It may be provided.

  The lens driving device 1 may include a zoom lens and have a zoom function.

1 Lens Drive 3 Yoke (Housing)
5 Lens support 16a-16d 2nd annular coil 19, 19a-19d 1st annular coil 17 1st magnet part 18 2nd magnet part 24 Front part 25 Control part 27 3rd magnet part 32 Z-theta drive part 33 X- Y drive unit

Claims (5)

  A lens support that supports the lens on the inner periphery, a first annular coil that is disposed on the outer peripheral surface of the lens support, and a plurality of second that are disposed on the outer peripheral surface of the lens support with an interval of 90 degrees in the circumferential direction. An annular coil, a base that movably supports the lens support, a first magnet unit, a second magnet unit, a third magnet unit fixed to the base, and a control unit that controls energization of each coil; The first magnet part is arranged facing the first annular coil, the second magnet part is arranged inside the ring of each second annular coil, and the third magnet part is arranged outside the ring of the second annular coil. The control unit sends an electric current to the first annular coil when moving the lens support in the optical axis direction, and applies a predetermined second annular coil when moving the lens support in the XY direction orthogonal to the optical axis. It is characterized by flowing current Lens driving device.   A plurality of first annular coils are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the lens support, the second annular coil is arranged at a position not overlapping the first annular coil, and the control unit is a lens 2. The lens driving device according to claim 1, wherein when the support is moved in the optical axis direction and when the lens support is tilted with respect to the optical axis, a current flowing through the predetermined first annular coil is made different.   The lens driving device according to claim 2, further comprising an annular yoke surrounding the lens support, wherein the first to third magnet portions are arranged on an inner peripheral surface of the yoke.   An autofocus camera comprising: the lens driving device according to claim 1; and an image sensor provided on a lens imaging side of a lens support.   A camera-equipped mobile phone comprising the autofocus camera according to claim 4.

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