JP2006350019A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device in which a long moving distance of a lens is ensured by a simple configuration while miniaturization is achieved. <P>SOLUTION: The lens drive device 1 includes: a yoke 3; a magnet 5 disposed on the yoke 3; a lens holder 7(9) to which a coil 11(13) is fixed; and an electrode 15(17) that supplies power to the coil 11(13). The lens drive device moves the lens holder 7(9) in the direction of the optical axis of the lens 31(43) by magnetic force generated by supplying power to the coil 11(13) from the electrode 15(17). The yoke 3, magnet 5, and the electrode 15(17) extend long along the direction of the optical axis. A coil terminal 39 fixed to the lens holder 7(9) moves along the optical axis together with the lens holder 7(9) while coming into contact with the electrode 15(17). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens driving device that is used in a portable small camera or the like and drives a lens in an optical axis direction.

  Patent Document 1 includes a yoke, a magnet provided on the yoke, a lens holder to which the coil is fixed, and a spring that supports the lens holder. The coil is energized through the spring, and electromagnetic force generated in the coil is used. A lens driving device that moves the lens holder in the optical axis direction of the lens is disclosed.

  In the lens driving device disclosed in Patent Document 1, when a coil is energized through a spring fixed to a base (housing) and the lens holder moves, the spring that supports the lens holder is deformed.

JP 2005-128405 A

  However, the above-described conventional technique has a problem that the lens holder can move only by the amount of deformation of the spring, and movement of the lens in the optical axis direction is limited. Further, when the amount of deformation of the spring is increased, the urging force of the spring is increased, and therefore there is a disadvantage that it is difficult to hold the lens holder at that position when it is largely moved.

  In particular, when an optical zoom lens is to be driven with a lens holder, the optical zoom lens needs to have a long moving distance, and thus there is a limit to miniaturization.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens driving device capable of taking a long lens moving distance with a simple configuration while achieving downsizing.

  The invention according to claim 1 includes a yoke, a magnet provided on the yoke, a lens holder to which the coil is fixed, and an electrode for energizing the coil, and the lens holder is generated by electromagnetic force generated by energizing the coil from the electrode. The yoke, magnet, and electrode are long along the optical axis direction, and the coil terminal fixed to the lens holder is always in contact with the electrode together with the lens holder. It moves along the optical axis.

  The invention according to claim 2 is the invention according to claim 1, wherein the yoke has a substantially double cylinder shape having an outer cylinder and an inner cylinder, the side line of the cylinder is parallel to the optical axis, and the magnet is It is arranged between the outer cylinder and the inner cylinder of the yoke, the electrode is provided on the outer peripheral side of the outer cylinder of the yoke, and the lens holder is provided with the lens support portion provided on the inner peripheral side of the inner cylinder and the electrode of the coil. The lens holder is movable along the optical axis direction by disposing the arm portion in an opening formed in the optical axis direction on the inner cylinder and the outer cylinder. .

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a guide member for guiding the movement of the lens holder is provided, the guide member is provided in the optical axis direction, and the guide member is provided in the lens holder. A guide hole to be inserted is formed, and the guide member is arranged next to the electrode.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the terminal of the coil is a curved leaf spring, and the curved portion of the leaf spring is pressed against the electrode by the elastic force of the spring. It is characterized by that.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein two lens holders are provided in the optical axis direction, one is a lens holder for a focus lens, and the other is The lens holder of the optical zoom lens is characterized in that a total of four electrodes are provided, two for each lens holder.

  According to the first aspect of the present invention, when a current is supplied to the electrode, a current flows from the terminal in contact with the electrode to the coil, an electromagnetic force acts on the coil, and a magnetic field formed by the magnet and the yoke As a result, the lens holder to which the coil is fixed moves to one side in the optical axis direction. Even when the lens holder moves, the electrode is long and the coil terminal is always in contact with the electrode, so that the lens holder can be driven to an arbitrary position. Further, when a current in the reverse direction is passed through the electrode, the lens holder can move the optical axis direction to the other. And since the spring like the prior art is not provided, if electricity supply is stopped, a lens holder will be hold | maintained in the position.

  Therefore, according to the present invention, the movement distance of the lens holder can be increased by increasing the length of the electrode according to the movement distance of the lens holder.

  The length of the electrode may be set in accordance with the moving distance of the lens holder, and the yoke and magnet may be provided longer in accordance with the moving distance of the lens holder. Therefore, the structure is simple and the degree of freedom in design is high.

  Only a yoke, a magnet, and an electrode are provided around the lens holder to which the coil is fixed along the optical axis direction, and it is small in size and simple in configuration.

  In particular, since the spring as in the prior art is not used for driving the lens holder, the configuration is simple and easy to design in this respect.

  According to the invention of claim 2, the operational effect of claim 1 can be obtained, and since the yoke has a double cylinder shape of the outer cylinder and the inner cylinder, leakage of magnetic force can be reduced, Since the coils are arranged on the circumference in the meantime, since the current flows so as to be orthogonal to the magnetic field, the driving force can be increased.

  Further, since the arm portion of the lens holder is disposed in the opening provided in the yoke and the electrode of the coil is brought into contact with the electrode disposed on the outer peripheral side of the yoke, the overall size of the apparatus can be made to be approximately the outer diameter of the yoke Therefore, it is possible to reduce the size with a simple configuration.

  According to the third aspect of the present invention, the lens holder can be moved smoothly by providing the guide member, and the guide member is inserted through the lens holder. Therefore, it is possible to prevent damage from shaking and impact.

  By arranging the guide member and the electrode adjacent to each other, the members provided accompanying the movement of the lens holder can be gathered and manufactured easily.

  According to invention of Claim 4, while having the effect as described in any one of Claims 1-3, it can maintain the contact of the terminal of a coil and an electrode with the elastic force of a leaf | plate spring, and is simple structure In addition to providing reliable contact between the terminal and the electrode, the elastic force of the spring is applied to the contact, so that when the lens holder is stopped at a predetermined position, the stop position is caused by the frictional force between the electrode and the terminal. Can be held.

  According to the invention described in claim 5, the effect described in any one of claims 1 to 4 is achieved, and two types of lenses, an optical zoom lens and a focus lens, are held by each lens holder. Even in the case where a common yoke and magnet are used, a compact configuration can be achieved.

  In particular, in the case of an optical zoom lens that requires a long movement distance, according to the optical zoom lens of various magnifications, it can be handled by simply changing or setting the length in the optical direction of each component member. Easy to design and manufacture.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1A shows a schematic configuration of a lens driving device according to an embodiment of the present invention, which is a cross-sectional view taken along the line AA in FIG. 2, and FIG. FIG. 1C is a side view of the portion shown in FIG. 1B, and FIG. 2 is a longitudinal sectional view showing a schematic configuration of the lens driving device according to the present embodiment. 3 is a perspective view of one lens holder extracted and viewed from one side in the optical axis direction, and FIG. 4 is a perspective view of the lens holder shown in FIG. 3 viewed from the other side in the optical axis direction. FIG. 5 is a perspective view showing the lens drive device shown in FIG. 2 by cutting the end surface. FIG. 6 is a perspective view showing the lens drive device shown in FIG.

  A lens driving device 1 according to the present embodiment is a lens driving device for an autofocus camera with an optical zoom incorporated in a mobile phone.

  The lens driving device 1 includes a yoke 3, a magnet 5, a first lens holder 7, a second lens holder 9, a first coil 11 fixed to the first lens holder 7, and a second lens holder 9. A fixed second coil 13, first electrodes 15 and 15 for supplying current to the first coil 11, and second electrodes 17 and 17 for supplying current to the second coil 13 are provided.

  The yoke 3 has a double cylinder shape having a substantially cylindrical outer cylinder (outer yoke) 19 and an inner cylinder (inner yoke) 21, and the outer cylinder 19 and the inner cylinder 21 have an annular shape provided on the end surface of the cylinder. They are connected by a bottom plate 22. The outer cylinder 19 and the inner cylinder 21 are arranged with their side lines substantially parallel to the optical axis of the lens held by the lens holder.

  Further, in the outer cylinder 19 and the inner cylinder 21, an opening 23 is formed in a part of the outer cylinder 19, and the opening 25 is formed in the inner cylinder 21 at a position facing the opening 23 of the outer cylinder. Yes.

  The magnet 5 is provided on the inner peripheral surface of the outer cylinder 19, and is disposed along the peripheral surface except for the opening 23. The magnet 5 has an S pole and an N pole formed in the radial direction.

  The first lens holder 7 is provided with a lens support portion 27 located inside the inner cylinder 21 and two arm portions 29 and 29 extending radially outward from the lens support portion. An optical zoom lens 31 is attached to 27. A coil support portion 33 is provided on the outer peripheral side in the radial direction of the lens support portion 27, and the first coil 11 is wound around the outer periphery of the coil support portion 33, and the coil support portion 33 and the first coil 11 are outer cylinders. It is located between the magnet 5 in contact with 19 and the inner cylinder 21.

  The arm portions 29 and 29 of the first lens holder 7 are disposed in the opening portion 25 of the inner tube 21 and the opening portion 23 of the outer tube 19, and the arm portion 29 can move freely through the openings 25 and 23. .

  A guide portion 35 is provided at the outer peripheral end of the arm portion 29, and a guide hole that is inserted into the guide member 37 is formed in the guide portion 35. The guide member 37 is fixed to the yoke 3 in parallel with the optical axis.

  Coil terminals 39 are provided on the left and right sides of one guide portion 35 so as to protrude to the outer peripheral side. Each terminal 39 is a curved leaf spring and is in contact with the first electrode 15 that opposes the curved abdomen.

  The first electrode 15 is disposed along the optical axis and has a length corresponding to the moving dimension of the first lens holder 7. The first electrode 15 is formed with a recess 40 on the terminal 39 side of the coil, and the terminal 39 is disposed in the recess 40 to hold the terminal 39.

  A current is supplied to the first electrode 15 when the first lens holder 7 is driven in one of the optical axis directions, and a current in the reverse direction is supplied when moving to the other.

  A focusing lens 43 is attached to the second lens holder 9, and the second lens holder 9 is provided behind the first lens holder 7 in the optical axis direction. Since the second lens holder 9 has substantially the same configuration as that of the first lens holder 7, the same reference numerals are given to portions having the same functions and effects as the constituent portions of the first lens holder 9, and details of the portions are described. The detailed explanation is omitted. The terminal 39 of the second coil 13 fixed to the second lens holder 9 is in contact with the second electrode 17 and supplied with current.

  The first electrodes 15 and 15 and the second electrodes 17 and 17 are each fixed to the yoke 3.

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

  When the optical zoom is used at the time of photographing with the camera, a current is supplied to the first electrode 15. Then, a current flows from the terminal 39 in contact with the first electrode 15 to the first coil 11, an electromagnetic force acts on the first coil 11, and due to the action of the magnetic field formed by the magnet 5 and the yoke 3. The first lens holder 7 to which the first coil 11 is fixed moves to one side in the optical axis direction. Since the first electrode 15 is long in accordance with the moving dimension of the first lens holder 7, the terminal 39 of the first coil 11 is kept in contact with the first electrode 15 even when the first lens holder 7 moves. Is done. Then, the lens holder is driven to an arbitrary position. The first lens holder moves the optical axis direction to the other side by applying a reverse current to the first electrode 15.

  After the zoom first lens holder 7 is moved to a predetermined position, the second electrode 17 is energized to move the focus second lens holder 9 in the same manner as the first lens holder 7 to focus the lens. .

  Since the lens holders 7 and 9 maintain contact between the coil terminals 39 and the electrodes 15 and 17 by the biasing force of the leaf springs, reliable contact between the terminals 39 and the electrodes 15 and 17 can be achieved with a simple configuration. In addition, when the lens holders 7 and 9 are stopped at predetermined positions, the stop positions are held by the frictional force with the terminal 39 electrodes 15 and 17. Accordingly, it is possible to prevent the lens holders 3 and 5 from being misaligned and rattled not only when shooting but also when being carried. The frictional force between the terminal 39 and the electrodes 15 and 17 can be easily adjusted by changing the elastic force and shape of the spring used as the terminal 39.

  According to the present embodiment, the movement distance of the lens holders 15 and 17 can be increased by increasing the length of the electrodes 15 and 17 according to the movement distance of the lens holders 7 and 9. Moreover, the arm portions 29 of the lens holders 7 and 9 are arranged in the openings 23 and 25 provided in the yoke 3 so that the terminals 39 of the coils 11 and 13 are brought into contact with the electrodes 15 and 17 provided on the outer peripheral portion of the yoke 3. As a result, the overall size of the yoke 3 can be made substantially the same as that of the yoke 3, and the size can be reduced with a simple configuration.

  The lengths of the electrodes 15 and 17 may be set in accordance with the movement distances of the lens holders 7 and 9, and even if the movement distance of the first lens holder 7 is increased or decreased due to different magnifications of the optical zoom. Accordingly, the length of the yoke 3, the magnet 5 and the electrode 15 in the optical axis direction may be designed, so that the configuration is simple and the degree of freedom in design is high. Further, since the spring for holding the lens holder as in the prior art is unnecessary, the configuration is simple in this respect.

  Since the yoke 3, the magnet 5, and the electrodes 15 and 17 are only provided along the optical axis direction around the lens holders 7 and 9 to which the coils 11 and 13 are fixed, the structure is small and the configuration is simple.

  The yoke 3 has a double cylinder shape of the outer cylinder 19 and the inner cylinder 21, and there is little magnetic leakage. Further, since the coils 11 and 13 are disposed between the outer cylinder 19 and the inner cylinder 21, all of the magnetic fields are magnetic. Since the current flows so as to be orthogonal to the driving force, the driving force is high.

  Since the guide member 37 is inserted through the arm portions 29 of the lens holders 7 and 9, the lens holders 7 and 9 can be moved smoothly and can be prevented from being damaged by shaking or impact.

  Since the yoke 3, the magnet 5 and the guide member 37 necessary for driving the first lens holder 7 and the second lens holder 9 are used in common, the number of parts is small and the structure is compact.

  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, the lens driving device 1 may include only the second lens holder without providing the first lens holder, and drive only the focusing lens.

  The yoke and the coil are not limited to being formed in a substantially cylindrical shape, and the electrodes 15 and 17 and the arm portions 29 of the lens holders 7 and 9 may be arranged at the corners of the square tube.

  Instead of arranging two first electrodes 15 next to each other and two second electrodes 17 next to each other, one first electrode 15 and one second electrode 17 may be arranged next to each other.

  The terminals 39 of the first and second coils 11 and 13 may be brushes each having a whisker shape.

(A) shows a schematic configuration of a lens driving device according to an embodiment of the present invention, and is a cross-sectional view taken along the line AA in FIG. 2, and (b) is an enlarged view of a portion B in (a). It is a figure shown, (c) is a side view of the part shown by (b). It is a longitudinal cross-sectional view which shows schematic structure of the lens drive device concerning this Embodiment. It is the perspective view which extracted and showed one lens holder and was seen from the one side of the optical axis direction. It is the perspective view which looked at the lens holder shown in FIG. 3 from the other side of the optical axis direction. It is a perspective view which cut | disconnects and shows the end surface of the lens drive device shown in FIG. FIG. 3 is a perspective view showing a yoke extracted from the lens driving device shown in FIG. 2.

DESCRIPTION OF SYMBOLS 1 Lens drive device 3 Yoke 5 Magnet 7 1st lens holder 9 2nd lens holder 11 1st coil 13 2nd coil 15 1st electrode 17 2nd electrode 19 Outer cylinder (outer side yoke)
21 Inner cylinder (inner yoke)
23 opening portion 25 opening portion 27 lens support portion 29 arm portion 35 guide portion 37 guide member 39 terminal of coil

Claims (5)

  A yoke, a magnet provided on the yoke, a lens holder to which the coil is fixed, and an electrode for energizing the coil, and the lens holder is moved in the optical axis direction of the lens by electromagnetic force generated by energizing the coil from the electrode In the lens driving device, the yoke, the magnet, and the electrode are long along the optical axis direction, and the coil terminal fixed to the lens holder moves along the optical axis together with the lens holder while always contacting the electrode. A lens driving device.   The yoke has a substantially double cylinder shape having an outer cylinder and an inner cylinder, the side line of the cylinder is parallel to the optical axis, the magnet is disposed between the outer cylinder and the inner cylinder of the yoke, and the electrodes are The lens holder is provided on the outer peripheral side of the outer cylinder of the yoke, and the lens holder has a lens support part provided on the inner peripheral side of the inner cylinder and an arm part provided with an electrode of the coil. 2. The lens driving device according to claim 1, wherein the lens holder is movable along the optical axis direction by disposing an arm portion in the opening formed in the lens.   A guide member for guiding the movement of the lens holder is provided, the guide member is provided in the optical axis direction, a guide hole for inserting the guide member is formed in the lens holder, and the guide member is disposed next to the electrode. The lens driving device according to claim 1, wherein the lens driving device is provided.   The lens driving device according to any one of claims 1 to 3, wherein a terminal of the coil is a curved leaf spring, and a curved portion of the leaf spring is pressed against the electrode by an elastic force of the spring. Two lens holders are provided in the optical axis direction, one is a lens holder for a focus lens, the other is a lens holder for an optical zoom lens, and a total of four electrodes corresponding to one lens holder. The lens driving device according to claim 1, wherein the lens driving device is provided.

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