JP2011069862A - Lens driving device, autofocus camera and cellular phone with camera - Google Patents

Abstract

Provided are a lens driving device, an autofocus camera, and a camera-equipped mobile phone that can correct the movement of the lens in the optical axis direction and the inclination of the optical axis and that can reduce the dimension in the optical axis direction.
A plurality of annular coils 19a to 19d arranged on the outer periphery of a lens support 5 at intervals in the circumferential direction, a magnet 17 fixed to a base 8 that supports the lens support movably back and forth, and an annular shape A control unit 25 that controls energization of the coils 19a to 19d, the annular coils 19a to 19d form a rectangular ring in a side view, and the magnet 17 faces the front side part 21 in the rectangular annular coil. When the lens support 5 is moved in the direction of the optical axis, the control unit 25 causes a current of equal current value A to flow through each annular coil, and when correcting the inclination of the optical axis of the lens, the current value passed through the corresponding annular coil. Different A + B.
[Selection] Figure 4

Description

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

  In Patent Document 1, a plurality of magnets are fixed to the outer periphery of the lens support at intervals in the circumferential direction, and the casing that supports the lens support so as to be movable in the optical axis direction is coiled at a position facing each magnet. And controlling the current flowing through each coil to incline the lens support so as to correct the linear movement of the lens support and the tilt of the optical axis.

International Publication WO2008 / 128407

  However, in the technique of Patent Document 1, the coil is wound in a cylindrical shape, the center line of the cylinder is parallel to the optical axis, and the magnet is disposed so as to face the end of the cylinder. There is a problem that the dimension in the optical axis direction (front-rear direction) is increased.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a lens driving device, an autofocus camera, and a camera-equipped mobile phone that can correct the movement of the lens in the optical axis direction and the inclination of the optical axis and can reduce the dimension in the optical axis direction. .

  According to the first aspect of the present invention, a lens support that supports a lens on the inner periphery, a plurality of annular coils that are arranged on the outer periphery of the lens support at intervals in the circumferential direction, and an outer periphery of the lens support are provided. The housing includes a housing that supports the lens support body so as to be movable back and forth, a magnet that is fixed to the housing and that faces the annular coils, and a controller that controls energization of the annular coils. A rectangular ring is formed, the magnet faces one side of the front or rear side of the rectangular ring coil, and the control unit is equal to each ring coil when moving the lens support in the optical axis direction. When the current of the current value is supplied and the inclination of the optical axis of the lens is corrected, the current value of the current supplied to the corresponding coil is made different.

  The invention according to claim 2 is the invention according to claim 1, wherein each annular coil has a gap formed between the front side or the rear side facing the magnet and the lens support. The side part is fixed to the lens support, and the housing is provided with a yoke. The yoke has an inner peripheral side part, an outer peripheral side part, and an intermediate part connecting the inner peripheral side part and the outer peripheral side part. The magnet is fixed to the inner periphery of the outer peripheral side portion of the yoke, and the inner peripheral side portion of the yoke is disposed in the gap between the one side portion of the annular coil and the lens support.

  According to a third aspect of the present invention, there is provided a lens support that supports a lens on the inner periphery, a plurality of magnets that are arranged at intervals in the circumferential direction on the outer periphery of the lens support, and a lens that is provided on the outer periphery of the lens support. A housing that supports the support body movably back and forth, an annular coil that is fixed to the housing and that faces each magnet, and a controller that controls energization of the annular coil. A rectangular ring is formed, the magnet faces one side of the front side or the rear side of the rectangular ring coil, and the control unit sends an equal current to each ring coil when moving the lens support in the optical axis direction. When a value current is supplied and the inclination of the optical axis of the lens is corrected, the current value of the current supplied to the corresponding coil is made different.

  According to a fourth aspect of the present invention, the lens driving device according to any one of the first to third aspects of the present invention and the image sensor provided on the image forming side of the lens of the lens support are provided, and the control unit is the image sensor. The autofocus camera is characterized in that the value of the current flowing through each annular coil is controlled so as to detect the peak of the high frequency component.

  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 annular coil is arranged in the circumferential direction on the outer periphery of the lens support, and the magnet faces the annular coil and is fixed to the housing. Since the coil and the magnet are not arranged in the optical axis direction, the size of the lens support in the front-rear direction (optical axis direction) can be reduced as compared with the prior art.

  Since the annular coil is arranged in the circumferential direction of the lens support, a long region for applying thrust along the peripheral surface of the lens support can be taken, and the lens support can be driven stably.

  The control means can correct the movement of the lens in the optical axis direction and the inclination of the optical axis by individually controlling the currents flowing through the respective annular coils.

  Further, since the optical axis can be easily corrected, it is possible to reduce the accuracy and assembly accuracy of the lens support and the components that hold the lens support so as to be movable, and to reduce the component defects and the lens drive device.

  According to the second aspect of the present invention, the effect described in the first aspect can be obtained, and the yoke is provided, so that the magnetic field density can be increased and the thrust acting on each annular coil can be increased. In addition, since the inner peripheral side of the yoke is disposed in the gap between the one side portion of the annular coil and the lens support, the installation space of the yoke can be reduced.

  According to the invention described in claim 3, since the annular coil and the magnet are replaced and arranged in the invention described in claim 1, the same effect as that of the invention described in claim 1 can be obtained. .

  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 a perspective view which cut and shows a part of lens drive device concerning a 1st embodiment. It is sectional drawing of the lens drive device which concerns on 1st Embodiment. It is a disassembled perspective view of the lens drive device concerning a 1st embodiment. It is a block diagram which shows the relationship between the lens support body in 1st Embodiment, and a control part. It is a perspective view which shows the external appearance of the lens drive device which concerns on 1st Embodiment. It is a figure which shows the effect | action of the lens drive device which concerns on 1st Embodiment. It is a perspective view which cuts and shows a part of lens drive device concerning a 2nd embodiment. It is sectional drawing of the lens drive device which concerns on 2nd Embodiment. It is a disassembled perspective view of the lens drive device which concerns on 2nd Embodiment.

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

  As shown in FIGS. 1 and 3, the lens driving device 1 includes an annular yoke 3, a lens support 5, a frame (housing) 7 and a front spring 9 disposed on the front side of the yoke 3 in the optical axis direction. A base (housing) 8 and a rear spring 11 disposed on the rear side of the yoke 3. A rear spacer (insulator) 15 is disposed between the rear spring 11 and the yoke 3. Yes.

  The yoke 3 has a substantially rectangular tube shape, and magnets 17 are fixed to the four corners on the inner peripheral side of the yoke 3. The yoke 3 includes an outer peripheral side wall 3a, an inner peripheral side wall 3b, and an intermediate portion 3c connecting the outer peripheral side wall 3a and the inner peripheral side wall 3b. The inner peripheral side wall 3b is provided only at the corner of the yoke. And in each corner | angular part of the yoke 3, the outer peripheral side wall 3a, the inner peripheral side wall 3b, and the intermediate part 3c comprise the cross-sectional substantially U shape. The yoke 3 is fixed between the base 8 and the frame 7.

  The magnet 17 has a substantially triangular plane when viewed from the front side, and an arc shape along the outer periphery of the lens support 5 on the inner peripheral side. The magnet 17 has, for example, an N pole on the inner peripheral side and an S pole on the outer peripheral side.

  The lens support 5 has a substantially cylindrical shape, and a lens (not shown) is fixed to the inner periphery thereof. Four annular coils 19a, 19b, 19c, and 19d are attached to the outer peripheral surface of the lens support 5 at equal intervals in the circumferential direction along the circumferential direction.

  Each annular coil 19a, 19b, 19c, 19d has a rectangular annular shape, and the rear side portion 23 of the rectangular annular coil is formed so as to project radially inward from the front side portion 21, The inner peripheral side of the rear side portion 23 is bonded and fixed to the outer peripheral surface of the lens support 5. Thereby, as shown in FIG.1 and FIG.2, the front side part 21 forms and fixes the clearance gap 20 between the outer peripheral surfaces of a lens support body.

  As shown in FIGS. 1 and 2, in each of the annular coils 19 a, 19 b, 19 c, 19 d, the magnet 17 is disposed facing only the front side portion 21.

  The inner peripheral side wall 3b of the yoke 3 is inserted into the gap 20 between the front side portion 21 of each annular coil 19a to 19d and the lens support 5, and the lens support 5 is attached to the inner peripheral side wall 3b. It is movable in the optical axis direction (front-rear direction).

  As shown in FIG. 4, each of the annular coils 19 a, 19 b, 19 c, 19 d is connected to the control unit 25, and a predetermined value of current is supplied from the control unit 25. The control unit 25 is connected to the image sensor 31 disposed on the image forming side of the lens, and detects the high-frequency component peak or contrast peak of the image sensor 31 as shown in FIG. e1 and inclination (deviation) e2 of the optical axis are detected. As shown in FIG. 4, the control unit 25 is provided with a moving unit 27 and an inclination correcting unit 29, and the moving unit 25 is provided to each annular coil 19 a, 19 b, 19 c, 19 d according to the moving amount of the lens support 5. The current A to be energized is calculated, and the inclination correcting unit 29 energizes each annular coil 19a, 19b, 19c, 19d corresponding to adjust the inclination of the lens support 5 in accordance with the inclination e2 of the optical axis of the lens. B is calculated. In the control unit 25, the annular coils 19a, 19b, 19c, and 19d are energized with the current A + B or the current value A calculated by the moving unit 27 and the inclination correcting unit 29.

  As shown in FIG. 3, the front spring 9 has a flat plate-like 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 a circular 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 yoke 3, and an inner peripheral side portion 9 b is fixed to the front end of the lens support 5. An outer peripheral side portion 11 a of the rear spring 11 is sandwiched between the base 8 and the rear spacer 15, and an inner peripheral side portion 11 b is fixed to the rear end of the lens support 5. Accordingly, 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.

  When the lens support 5 moves forward, the lens support 5 moves between the resultant force of the urging forces of the front spring 9 and the rear spring 11 and the annular coils 19a, 19b, 19c, 19d and the magnet 17. Stops at a position where the generated electromagnetic force is suspended.

  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 FIGS. 1, 2 and 3, the lens driving device 1 is assembled by fixing a rear spring 11, a rear spacer 15, and annular coils 19 a, 19 b, 19 c and 19 d to the outer peripheral surface of the base 8. The lens support 5, the yoke 3 with the four magnets 17 fixed to the inner corner, the front spring 9 and the frame 7 are assembled and fixed in this order.

  Each of the annular coils 19a, 19b, 19c, and 19d has an input end and an output end connected to a control unit (power source) 25, and the control unit 25 individually supplies a direct current flowing through each of the annular coils 19a, 19b, 19c, and 19d. Control.

  As shown in FIG. 4, the driving of the lens driving device 1 according to the present embodiment compares the peak of the high frequency component (contrast) received by the control unit 25 from the image sensor 31, and the focal position e1 (FIG. 6). The lens support 5 is linearly moved to (see).

  When the lens support 5 is linearly moved, as shown in FIG. 4, between the control unit 25 and the magnet 17 generated by flowing the same current value A to each of the annular coils 19 a, 19 b, 19 c, 19 d. It stops at the position where the generated electromagnetic force and the resultant force of the urging force of the front spring 9 and the rear spring 11 are suspended.

  In each of the annular coils 19a, 19b, 19c, 19d, currents flow in opposite directions on the front side 21 and the rear side 23, but the magnet 17 faces the front side 21, so the front side Thrust can be obtained by the electromagnetic force generated between the side portions 21.

  On the other hand, as shown in FIG. 6, 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, as shown in FIG. 4, a current A + B obtained by adding a current value B to a predetermined annular coil (one, two, or three) of the annular coils 19a, 19b, 19c, and 19d. Thus, the posture (tilt) of the lens support 5 is controlled. In addition, you may make it the electric current which flows relatively differ by deducting the electric current value B and flowing the electric current of AB.

  In addition, the inclination of the optical axis of the lens support 5 may be corrected after the lens support 5 is moved to a predetermined position, or when the lens support 5 is moved, the tilt is controlled (each annular coil is moved). Or a current value A + B for controlling the slope from when the current flowing in the current is moved.

  In the first embodiment, each annular coil (for example, 19a) and the corresponding magnet 17 form one drive means, and each of the annular coils 19a, 19b, 19c, 19d and A total of four driving means are arranged around the lens support 5 by the corresponding magnets 17.

  Therefore, according to the first embodiment, thrust is applied to the range support 5 by the annular coils 19a to 19d disposed at equal intervals in the circumferential direction on the outer periphery of the lens support 5 and the magnet 17 facing each other. Therefore, the two functions of the movement of the lens support 5 in the optical axis direction and the correction of the optical axis of the lens can be combined.

  The annular coils 19a to 19d and magnets 17 that apply thrust at each circumferential part of the lens support 5 and the magnet 17 are arranged on the outer peripheral surface of the lens support 5, and unlike the prior art, the coils and Since no magnet is disposed, the size of the lens support 5 in the front-rear direction (optical axis direction) can be reduced as compared with the prior art.

  Since the optical axis can be easily corrected, the accuracy and assembly accuracy required for the lens support 5 and parts (for example, springs 9 and 11) for holding the lens support 5 movably can be lowered, and these components are defective. In addition, defects of the lens driving device 1 can be reduced.

  Other embodiments of the present invention will be described below. In the following description, parts having the same functions and effects as those of the first embodiment described above are denoted by the same reference numerals, and the details of the parts are described. The description will be omitted, and different points from the first embodiment will be mainly described.

  A second embodiment will be described with reference to FIGS. In this second embodiment, the yoke 3 has no inner peripheral side wall, and four annular coils 19a to 19d are fixed to the inner peripheral surface of the outer peripheral side wall 3a at equal intervals in the circumferential direction. The magnet 17 is fixed to the outer peripheral surface of 5 at a position facing the front side portion 21 of each of the annular coils 19a to 19d. The magnet 17 is fixed to the outer peripheral surface of the lens support 5 via a plate-like auxiliary yoke 33, and the magnetic field path surrounding the front portion 21 of the annular coil and the magnet 17 is formed by the yoke 3 and the auxiliary yoke 33. is doing.

  That is, the second embodiment is different from the first embodiment in that the magnet 17 is fixed to the lens support 5 and the annular coils 19a to 19d are fixed to the yoke 3.

  Also in the second embodiment, the same effects as those in the first embodiment described above can be obtained.

  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 first and second embodiments, the optical axis inclination e2 (see FIG. 6) may be detected by an acceleration sensor or may be detected by a gyro sensor.

  The number of magnets corresponding to the annular coils 19a to 19d and each annular coil is not limited to four around the lens support 5, and may be three or five, and the number thereof is not limited.

  In the first embodiment, the gap 20 is provided between the lens support 5 and the front side portion 21 of the annular coils 19 a to 19 d so that the inner peripheral side wall 3 b of the yoke 3 is inserted into the gap 20. Without providing the inner peripheral side wall 3b, the front side portion 21 of the annular coils 19a to 19d may only face the magnet 17, or the magnet 17 faces the rear side portion 23 of the annular coils 19a to 19d. You may let them.

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

DESCRIPTION OF SYMBOLS 1 Lens drive device 5 Lens support body 17 Magnet 19a, 19b, 19c, 19d Annular coil 21 Front part (one side part)
23 Rear part (other side part)
25 Control Unit 27 Moving Unit 29 Tilt Correction Unit 31 Image Sensor

Claims (5)

  A lens support that supports the lens on the inner periphery, a plurality of annular coils arranged circumferentially on the outer periphery of the lens support, and an outer periphery of the lens support so that the lens support can be moved back and forth. A supporting housing, a magnet fixed to the housing and arranged facing each annular coil, and a control unit for controlling energization to the annular coil, the annular coil forming a rectangular ring in side view The magnet faces one side of the front or rear side of the rectangular annular coil, and when the control unit moves the lens support in the optical axis direction, a current of an equal current value flows through each annular coil, A lens driving device characterized in that when correcting the inclination of the optical axis, the current value of the current flowing through the corresponding coil is varied.   Each annular coil has a gap between the front and rear sides of the magnet facing the lens support, and the other side is fixed to the lens support, and a yoke is provided on the housing. The yoke has an inner peripheral side portion, an outer peripheral side portion, an intermediate portion connecting the inner peripheral side portion and the outer peripheral side portion, and a magnet is fixed to the inner periphery of the outer peripheral side portion of the yoke. The lens driving device according to claim 1, wherein an inner peripheral side portion of the lens is disposed in the gap between one side portion of the annular coil and the lens support.   A lens support that supports the lens on the inner periphery, a plurality of magnets arranged at intervals in the circumferential direction on the outer periphery of the lens support, and a lens support that is provided on the outer periphery of the lens support so as to be movable back and forth. An annular coil fixed to the casing and facing each magnet, and a control unit that controls energization to the annular coil, the annular coil forming a rectangular ring in a side view, The magnet faces one side of the front or rear side of the rectangular ring coil, and when the control unit moves the lens support in the direction of the optical axis, a current of an equal current value flows through each ring coil, and the lens light A lens driving device characterized in that the current value of the current flowing through the corresponding coil is varied when correcting the tilt of the shaft.   A lens driving device according to any one of claims 1 to 3 and an image sensor provided on an image forming side of a lens of a lens support, and the control unit detects a peak of a high frequency component of the image sensor. As described above, an autofocus camera is characterized in that the value of a current flowing through each annular coil is controlled.   A camera-equipped mobile phone comprising the autofocus camera according to claim 4.

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