JP2005121859A - Lens driving device and portable equipment with camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make powder caused by sliding hardly adhere to a lens, and to easily secure perpendicularity to the optical axis of the lens. <P>SOLUTION: This lens driving device 1 comprises a lens holder 10 for holding the lens 13, and driving means 16, 28, 30 for moving this lens holder 10 along the optical axis 11 of the lens 13. Then, the lens driving device has a guide part 26a which is engaged with engagement parts 12b, 12d arranged on the lens holder 10 and guides straight moving operation of this lens holder 10 along the optical axis in the aligned state, and the engagement parts 12b, 12d are arranged outside the driving means 16, 28, 30 in a radial direction, and the lens 13 is arranged inside the driving means 16, 28, 30 in the radial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens driving device and a portable device with a camera incorporating the lens driving device.

  A thin camera mounted on a camera-equipped mobile phone or the like has a shorter lens movement distance for performing focus adjustment and zoom adjustment in shooting than a normal camera. For this reason, as a lens driving device applied to these cameras, a lens driving device that directly magnetically drives the lens is suitable.

  As such a magnetic drive type lens driving device, for example, the following is known. That is, it has a cylindrical lens holder that holds the lens, a ring-shaped rotor magnet attached to the outer periphery of the lens holder, and a drive coil that faces the rotor magnet, and by controlling energization to the drive coil, A configuration has been devised in which a lens holder for holding a lens is directly moved in the optical axis direction without using a conversion mechanism, and the lens holder is magnetically held therein (see Patent Document 1).

  On the other hand, what employs a guide shaft that guides a lens holder holding a lens along the optical axis is known as an example of using a conversion mechanism that converts the rotational force of the motor into a straight motion. (For example, refer to Patent Documents 2 and 3).

JP-A-10-150759 (page 3-5, FIG. 1-3) JP-A-9-106314 (FIG. 1) JP-A-10-142472 (abstract)

  Among conventional lens driving devices described in Patent Document 1, that is, a case in which a case for holding a lens is magnetically driven in the optical axis direction and magnetically held there, the lens is held at a predetermined position for a long time. When trying to hold, it is necessary to energize the drive coil while holding. Therefore, there is a problem that power consumption increases and it is not suitable for mounting on a mobile device such as a mobile phone, which originally has a limited power battery capacity.

  On the other hand, what is described in Patent Documents 2 and 3 has a complicated mechanism for converting rotational force into linear movement, increases the number of parts, and is mounted on a portable device such as a cellular phone. There is a problem that it is not suitable for. In addition, since the conversion mechanism is arranged on the side of the lens in the radial direction, the length in the radial direction becomes large, which tends to be a problem in terms of miniaturization.

  Further, the conventional apparatus is close to the position of the lens and the member that guides the movement of the lens holder that holds the lens, and the sliding powder generated during the guide tends to adhere to the lens. In addition, since the guide portion is located near the lens, that is, the center, generally, a slight component accuracy error or assembly accuracy error affects the perpendicularity to the optical axis of the lens. .

  The present invention has been made to solve the above-described problems, and prevents sliding powder generated when the lens holder slides from adhering to the lens and ensures perpendicularity to the optical axis of the lens. It is an object of the present invention to provide a lens driving device that is easy. Another object of the present invention is to provide a lens driving device that enables low power consumption and is easy to miniaturize, in addition to the above-described object. Another object of the present invention is to provide a camera-equipped mobile device that can improve the quality of an image obtained by a lens driving device.

  In order to achieve the above-described object, a lens driving device according to the present invention includes a lens holder that holds a lens and a driving unit that moves the lens holder along the optical axis of the lens. A guide portion that engages with the provided engagement portion and guides the linear movement operation along the optical axis of the lens holder in an adjusted state; the engagement portion is disposed radially outside the drive means; The lens is disposed radially inside the driving means.

  In this invention, since the engaging portion that engages with the guide portion is arranged outside the driving means and the lens is arranged inside the driving means, the portion where the lens holder slides and the lens portion are located apart from each other. It becomes. For this reason, the sliding powder generated at the sliding portion is less likely to adhere to the lens. In addition, the diameter of the lens holder is increased to the outside of the driving means, and the guide portion is separated from the center of the lens because the lens holder is guided by the engaging portion disposed on the outer portion thereof. As a result, it becomes easy to ensure the perpendicularity to the optical axis of the lens.

  In another invention, in addition to the lens driving device described above, the engaging portion is guided by a guide portion made of the same member as the engaging portion. If comprised in this way, it will become difficult to generate | occur | produce the sliding powder which arises by sliding of an engaging part and a guide part.

  According to another invention, in addition to the above-described inventions, the lens holder includes a cylindrical body having an engagement portion formed on the outer periphery and extending in the optical axis direction, and a substantially vertical direction from the inner periphery of the cylindrical body to the inner side in the radial direction. And a magnet or a coil as a driving means is held by the inner periphery of the cylindrical body and the extended portion. When this configuration is adopted, a sufficient holding area of the driving means can be secured, and the parallelism of the magnet or coil as the driving means can be easily secured.

  Further, it is preferable that a slit extending in the optical axis direction is provided in a part of the cylindrical body, and a rotation prevention protrusion that enters the slit and prevents the lens holder from rotating is provided in the main body holder having the guide portion. With this configuration, the lens holder can be prevented from being rotated with a simple configuration in which a slit is provided in a part of the cylindrical body and a rotation-preventing protrusion is provided at a position corresponding to the slit.

  Further, it is preferable that the lens holder and the lens are integrally molded, and a diaphragm or a light shielding part is printed on the integrally molded product. When this configuration is adopted, the diaphragm or light shielding is easily formed, and the assembly is made efficient.

  According to another aspect of the present invention, there is provided a lens driving device including: a lens holder that holds a lens; a driving unit that moves the lens holder in the optical axis direction of the lens; and a fixed body that holds the lens holder. The lens holder includes one of a drive magnet and a drive coil among the drive means, the fixed body includes one of the drive magnet and the drive coil among the drive means, and the drive magnet and the drive coil are mutually connected. The lens holder can be moved by a magnetic attractive force or a magnetic repulsive force, and is arranged in the optical axis direction. The fixed body is engaged with an engaging portion provided in the lens holder, and the lens holder is aligned with the optical axis. A guide portion that guides the linear motion along the guide portion, the engaging portion is disposed on the radially outer side of the driving means, and the lens is disposed on the radially inner side of the driving means.

  In this invention, the lens holder is driven in the direction of the optical axis by the magnetic attractive force or the magnetic repulsive force, so that the driving means becomes simple and easy to downsize, and it is not necessary to energize except during driving. . In addition, since the engaging portion that engages with the guide portion is arranged outside the driving means and the lens is arranged inside the driving means, the portion where the lens holder slides and the lens portion are located apart from each other. . For this reason, the sliding powder generated at the sliding portion is less likely to adhere to the lens. In addition, the diameter of the lens holder is increased to the outside of the driving means, and the guide portion is separated from the center of the lens because the lens holder is guided by the engaging portion disposed on the outer portion thereof. As a result, it becomes easy to ensure the perpendicularity to the optical axis of the lens.

  In addition to the above-described invention, the lens holder includes a drive magnet that can move in the optical axis direction together with the lens, and the fixed body forms a magnetic circuit with the drive magnet and in the optical axis direction of the lens. A first drive coil and a second drive coil, the first drive coil and the second drive coil, and a first magnetic piece and a second magnetic piece disposed opposite to the first drive coil and the second drive coil. When energization of the coil is stopped, the lens holder is held at a predetermined position by magnetic attraction between the drive magnet and the first magnetic piece or the second magnetic piece, and the lens is obtained by energizing the first drive coil or the second drive coil. The holder is moved between the first drive coil and the second drive coil.

  In the present invention, the lens holder is held at a predetermined position by the action of the first magnetic piece and the second magnetic piece. For this reason, it is not necessary to energize the first and second driving coils for driving when holding the position. As a result, low power consumption can be achieved.

  According to another aspect of the present invention, there is provided a camera-equipped mobile device having the lens driving device according to any one of claims 1 to 7 as a camera unit and display means for displaying an image obtained by the lens driving device. ing.

  In this camera-equipped mobile device, the sliding powder generated when driving the lens driving device incorporated therein is less likely to adhere to the lens, so that the quality of the obtained image can be maintained at a high level. Further, since it becomes easy to ensure the perpendicularity to the optical axis of the lens, distortion of the obtained image is eliminated.

  In the lens driving device of the present invention, sliding powder generated when the lens holder is guided and slid does not easily adhere to the lens, and it is easy to ensure the perpendicularity to the optical axis of the lens. In addition, the lens driving device according to another aspect of the invention can achieve low power consumption and can be easily downsized. Moreover, the camera-equipped mobile device of the present invention can improve the quality of an image obtained by the lens driving device.

  Embodiments of a lens driving device and a camera-equipped mobile device according to the present invention will be described below with reference to the drawings. In the following description, the lens driving device, which is the main part of the camera-equipped mobile device, will be mainly described. The lens driving device shown in each embodiment has a configuration suitable for mounting as a camera portion of a mobile device such as a mobile phone, but is mounted on another mobile device such as a PDA (Personal Digital Assistance). Anyway.

  The lens driving device 1 according to the first embodiment shown in FIGS. 1 to 5 mainly includes a lens holder 10 that is a moving body and a fixed body 24 that holds the lens holder 10. The lens holder 10 has the optical axis 11 located at the center thereof, and has a substantially cylindrical cylindrical body 12 extending in the direction of the optical axis 11, and the lens 13 is provided inside the cylindrical body 12. It has been. The lens 13 is a zoom lens of the camera, and is capable of wide-angle shooting and telephoto shooting by moving back and forth in the direction of the optical axis 11. In the following, the upper side of FIG. 1 is referred to as the subject side, and the lower side of FIG. 1 is referred to as the imaging side.

  A driving magnet 16 that is a part of a driving means formed in a ring shape is fixed to the cylindrical body 12 so as to be in contact with the inner peripheral surface of the cylindrical body 12. An extension portion 17 that extends substantially perpendicular to the cylinder 12 and holds the lens 13 at the center is formed at the center upper portion of the inner periphery of the cylinder 12. The drive magnet 16 is also in contact with the lower side in FIG. In addition, the drive magnet 16 is disposed substantially at the center of the cylindrical body 12 in the direction of the optical axis 11.

  In this embodiment, the cylindrical body 12 and the extending portion 17 are integrally molded from a polycarbonate resin material. Note that other resin materials such as acrylic may be used instead of polycarbonate. The lens 13 is an aspheric resin lens and is integrally molded with the extending portion 17. Alternatively, the lens 13 may be a separate member and fixed to the extending portion 17 by bonding or the like.

  As shown in FIG. 2, the subject-side end face of the cylindrical body 12 is provided with subject-side positioning projections 12a at intervals of 120 degrees, and the subject-side side surface is lighted at the same position in the circumferential direction as the positioning projections 12a. A guide protrusion 12b is provided as a movement guide in the direction of the shaft 11. In addition, an imaging-side positioning projection 12c is provided on the imaging-side end surface of the cylindrical body 12 so as to be at an interval of 120 degrees and in the center between the positioning projections 12a. And a guide projection 12d on the imaging side serving as a movement guide in the direction of the optical axis 11 is provided at the same position in the circumferential direction.

  In this embodiment, the positioning protrusion 12a and the positioning protrusion 12c are shifted by 60 degrees on the subject side and the imaging side, and the guide protrusion 12b and the guide protrusion 12d serving as the engaging portions are similarly shifted by 60 degrees. All may be arranged at the same position in the circumferential direction. Further, the number of positioning protrusions 12a and 12c and guide protrusions 12b and 12d is not limited to three, but may be other numbers such as four or five. Further, the guide protrusions 12b and 12d may be a ring-shaped protrusion over the entire circumference instead of a plurality of protrusions.

  A part of the cylindrical body 12 on the imaging side is provided with a rotation-preventing slit 12e cut in the direction of the optical axis 11 from the open end. The slit 12e is notched with a width of about 5 to 10 degrees in the circumferential direction, and a detent projection 26h (see FIG. 1B) provided on the fixed body 24 described later enters. ing.

  The extending portion 17 is provided with a vent hole 17a so that the lens holder 10 moves smoothly when the lens holder 10 moves. A total of four vent holes 17a are provided at intervals of 90 degrees, but other numbers may be used. A thick portion 17b is provided around the lens 13 in a ring shape to ensure the accuracy of the lens 13 during molding.

  A fixed lens 14 on the subject side is arranged on the upper side of FIG. 1, and a fixed lens 15 on the imaging side is arranged on the lower side. The lens 13 that moves in the direction of the optical axis 11 and the fixed lenses 14 and 15 form a photographic optical system that can be zoomed.

  A diaphragm 18 of the photographing optical system is disposed so as to overlap a portion surrounding the lens 13 of the extending portion 17 and a part of the outer periphery of the lens 13. The diaphragm 18 has a ring shape and is attached to the imaging side of the lens 13. The diaphragm 18 may not be a separate member from the lens 13 and the extended portion 17 but may be directly formed as a shielding portion on the lens 13 or the like by printing, and may be an integral member with the lens 13 or the like. The method of forming the shielding portion by printing can be applied to the formation of a light shielding member in addition to the diaphragm 18.

  As shown in FIG. 3, the drive magnet 16 that operates integrally with the lens holder 10 has a ring shape, the portion surrounding the central hole 16a is magnetized to the N pole, and the entire outer peripheral portion is set to the S pole. Unipolar magnetized. In this magnetizing relationship, NS may be reversed. As described above, the outer peripheral side surface of the drive magnet 16 is in contact with the inner peripheral surface of the cylindrical body 12, and the plane on the subject side is in contact with the extending portion 17. The drive magnet 16 is housed so as to be movable relative to the fixed body 24 in the direction of the optical axis 11.

  The lens holder 10 is inserted into the fixed body 24. The fixed body 24 includes a lid member 25 and a main body holder 26. The fixed lens 14 on the subject side is fitted into a circular hole 25a at the center of the substantially ring-shaped lid member 25, and is fixed with an adhesive or the like. At the front end of the lid member 25, that is, on the subject side, a circular hole 25a serving as a circular incident window for taking in reflected light from the subject into the lens 14 is formed. An openable / closable barrier for protecting the lens is provided in front of the circular hole 25a, but the illustration is omitted.

  The main body holder 26 is also formed in a substantially cylindrical shape so that the guide protrusions 12b and 12d of the cylindrical body 12 can move in the direction of the optical axis 11 of the lens 13 using the inner peripheral surface 26a of the outer wall of the main body holder 26 as a guide. Further, the lens holder 10 is fitted into the main body holder 26. The material of the main body holder 26 is polycarbonate, which is the same material as the cylindrical body 12. Thus, the generation of sliding powder can be suppressed by using the same material for the cylinder 12 and the main body holder 26. The body holder 26 may be made of POM (polyoxymethylene), so-called polyacetal resin, so as to increase the slidability.

  The limit of movement of the lens holder 10 toward the back side, that is, the imaging side, is determined by the positioning projection 12c existing at the rear end of the cylinder 12 coming into contact with the bottom surface 26b of the main body holder 26. Yes. The right half of FIG. 1 and FIG. 4 show a state in which the lens holder 10 has moved to the farthest side. The limit of movement of the lens holder 10 toward the front side, that is, the subject side is determined by the positioning projection 12a existing at the front end of the cylindrical body 12 coming into contact with the outer peripheral contact surface 25b of the lid member 25. The left half of FIG. 1 shows a state in which the lens holder 10 has moved most forward.

  Further, the ring-shaped recess 26e, which is the inner circumference of the main body holder 26 and is surrounded by the outer ring-shaped projection 26c and the inner ring-shaped projection 26d, is located behind the drive magnet 16. In addition, a first drive coil 28 wound in a ring shape so as to face the drive magnet 16 is disposed. A second drive coil 30 is arranged on the lid member 25 side so that the drive magnet 16 is sandwiched with respect to the first drive coil 28.

  A ring-shaped first magnetic piece 32 is fitted on the flange side of the first drive coil 28, and both the first magnetic piece 32 and the first drive coil 28 are fixed by the outer periphery of the ring-shaped protrusion 26 d of the main body holder 26. Yes. The first magnetic piece 32 is also fixed to the bottom surface of the main body holder 26 by bonding or the like. As described above, the front end face of the first drive coil 28 and the rear end face of the drive magnet 16 face each other.

  As described above, the second drive coil 30 wound in a ring shape is fitted on the outer periphery of the ring-shaped protrusion 25 c of the lid member 25 at a position ahead of the drive magnet 16. Further, a ring-shaped second magnetic piece 34 is fitted over the drive coil 30 and is fixed to the lid member 25 by adhesion or the like. The front end surface of the drive magnet 16 and the rear end surface of the second drive coil 30 face each other with the extending portion 17 therebetween. Therefore, the first magnetic piece 32 and the second magnetic piece 34 are arranged on the outer end surfaces of the first drive coil 28 and the second drive coil 30 arranged in the direction of the optical axis 11 with the drive magnet 16 in between, respectively. Will be. The drive magnet 16 is sandwiched between the first and second drive coils 28 and 30 in the direction of the optical axis 11.

  The first and second magnetic pieces 32 and 34 are made of a washer-like ferromagnetic material, for example, a steel plate. The magnetic flux emitted from the drive magnet 16 passes through the first drive coil 28 and the first magnetic piece 32 from the center side to the outer peripheral side and returns to the drive magnet 16. Further, the magnetic flux from the drive magnet 16 reaches the drive magnet 16 through the second magnetic piece 34 and the second drive coil 30 from the center side to the outer periphery side, and these members constitute a magnetic circuit. Has been. Therefore, the first and second drive coils 28 and 30 are located in the magnetic field formed by the drive magnet 16. In this way, the drive means is constituted by the drive magnet 16, the first drive coil 28, and the second drive coil 30.

  The distance between the opposing surfaces of the first and second drive coils 28 and 30 is greater than the sum of the thickness of the drive magnet 16 in the direction of the optical axis 11 and the thickness of the extending portion 17 in the direction of the optical axis. A gap in the direction of the optical axis 11 is formed between the drive magnet 16 and the first drive coil 28 or the second drive coil 30, and the drive magnet 16 is integrated with the drive magnet 16 within this gap. The lens holder 10 can move in the direction of the optical axis 11.

  As shown in FIG. 1B, the main body holder 26 is provided with a non-rotating projection 26h that serves as a detent for the lens holder 10. This anti-rotation protrusion 26h is provided on the imaging side on the inner peripheral surface 26a of the outer wall of the main body holder 26, and its installation range is about 4 to 9 degrees in the circumferential direction. This anti-rotation protrusion 26h enters the slit 12e and functions as a detent in the circumferential direction of the lens holder 10.

  On the heel side along the optical axis 11 of the lens driving device 1, a filter 43 is disposed on the subject side of the rear end member 42 fixed to the pedestal portion 41. The filter 43 is locked and fixed to the step portion 26g of the ring-shaped protrusion 26f at the center of the main body holder 26. An imaging element 44 is fixedly disposed on the rear end member 42. The filter 43 is for cutting light of a predetermined wavelength corresponding to the detection wavelength of the image sensor 44. The image sensor 44 is configured by a CMOS (Complementary Metal Oxide Semiconductor) and sends a detection signal to the circuit board 45. An image signal serving as a detection signal is sent to a control unit (configured by a microcomputer or the like) (not shown) via the circuit board 45. In addition to the CMOS, a CCD, a VMIS, or the like can be used as the image sensor 44.

  In the lens driving device 1, the fixed lens 14 on the subject side is an aspherical lens that is integrally resin-molded with the frame portion 46. Further, the fixed lens 15 on the imaging side is also an aspheric lens molded integrally with the frame 47 by resin. The lid member 25 and the main body holder 26 are fixed by an adhesive or welding, and the main body holder 26 and the base portion 41 are fixed by an adhesive 48.

  The lens driving device 1 is arranged such that the case surface of a mobile phone serving as a portable device and the surface 48 of the lid member 25 are on the same plane or substantially the same plane. In addition, the image pickup device 44 and the circuit board 45 are arranged between the case back surface of the mobile phone and the lens 15. For this reason, sufficient space can be taken in the outer peripheral part of the lens drive device 1, and it becomes easy to incorporate this lens drive device 1 in a portable apparatus.

  Next, an assembling method of the lens driving device 1 according to the first embodiment will be described with reference to FIGS. 1 and 4 to 6.

  First, the rear end member 42 having the imaging element 44, the circuit board 45, the filter 43, and the like is fitted and fixed to the pedestal 41. On the other hand, the first magnetic piece 32 is put into the main body holder 26 and fixed. Next, the first drive coil 28 is placed and fixed on the first magnetic piece 32. Further, the filter 43 and the lens 15 are incorporated in the main body holder 26. Thereby, the main body holder assembly 26A is completed. Further, the lens 14 is fixed to the lid member 25 by adhesion or the like. Further, the second magnetic piece 34 is assembled and fixed to the lid member 25, and the second drive coil 30 is placed on the second magnetic piece 34 and fixed. Thereby, the cover member assembly 25A is completed. Thereafter, the driving magnet 16 is fixed, and the lens holder 10 having the lens 13 inside is incorporated into the main body holder 26.

  Thereafter, the lid member part set 25A is fitted into the main body holder part set 26A and temporarily fixed. In this state, the main body holder assembly 26A is placed in the pedestal 41 and the distance between the image sensor 44 and the lens 13 is adjusted so that the lens 13 can obtain an appropriate image at the wide-angle shooting position. The adhesive 48 is inserted between the base part 41 and the main body holder part assembly 26A at the position in such a state, and both are fixed.

  Next, the lid member assembly 25A is moved back and forth in the direction of the optical axis 11, and the lid member assembly 25A is fixed at a position at which the lens 13 can perform appropriate photography through telephoto photography. That is, the lid member assembly 25A is mounted on the main body holder portion so that an appropriate telephoto image can be obtained at a telephoto position where the positioning projection 12a on the front end surface of the cylindrical body 12 abuts against the outer peripheral contact surface 25b of the lid member 25. The set 26A is moved back and forth in the direction of the optical axis 11, and is fixed at an appropriate position using an adhesive or the like.

  Next, the operation of the lens driving device 1 configured as described above will be described.

  First, as shown in the right half of FIG. 1 and FIG. 4, even if the drive magnet 16 moves to the heel side together with the lens holder 10 and the first and second drive coils 28 and 30 are not energized, Suppose that it is the state hold | maintained in the position moved by the magnetic attraction force produced between the 1st magnetic bodies 32. FIG. The position of the lens 13 at this time is a wide-angle shooting position (hereinafter referred to as a wide-angle shooting position). At this time, the positioning protrusion 12c on the rear end surface of the lens holder 10 collides with the bottom surface 26b of the main body holder 26, thereby preventing the rearward advancement thereof. At this stop position, a slight gap is generated between the drive magnet 16 and the first drive coil 28. This is because when one of the first drive coil 28 and the drive magnet 16 collides, either one or both are damaged, and the collision is prevented.

  In the state shown in the right half of FIG. 1 and FIG. 4, when a predetermined zoom switch (not shown) is operated, current flows in at least one direction of the first and second drive coils 28 and 30, and the direction of this current Depending on the direction of the magnetic field generated by the driving magnet 16, an electromagnetic force acts to push the driving magnet 16 forward according to Fleming's left-hand rule, and the lens holder 10 advances forward together with the driving magnet 16. This advance amount is within the above-described gap generated between the drive magnet 16 and the first and second drive coils 28 and 30. The lens 13 together with the lens holder 10 advances forward to become a telephoto shooting position (hereinafter referred to as a telephoto shooting position). This state is shown as the left half of FIG.

  Note that Fleming's left-hand rule shows the relationship of forces acting on an object that is carrying a line current when a line current flows in the magnetic field. In this embodiment, the driving coil 28 , 30 are fixed together, a force acts on the drive magnet 16 as a reaction.

  When the lens holder 10 advances forward, the positioning protrusion 12a existing on the front end surface of the lens holder 10 collides with the outer peripheral contact surface 25b, thereby preventing the front advancement. The position of the lens 13 that has advanced forward is held by the magnetic attractive force generated between the drive magnet 16 and the second magnetic body 34 even when the drive coils 28 and 30 are not energized. Also at this time, a slight gap is generated between the second drive coil 30 and the extended portion 17. This is also for preventing the second drive coil 30 and the extended portion 17 from colliding and damaging them.

  The electromagnetic force generated during the forward movement is generated in such a direction that the drive magnet 16 is moved forward when the first drive coil 28 is energized, and the drive magnet 16 is moved forward when the second drive coil 30 is energized. Generate in the direction to move to. Both the first and second drive coils 28 and 30 may be energized simultaneously, or one of them may be energized.

  To switch from the telephoto shooting position to the wide-angle shooting position, the zoom switch is switched to the wide-angle shooting position. By this switching, at least one of the first and second drive coils 28 and 30 is energized in the opposite direction. Depending on the direction of the current and the direction of the magnetic field generated by the drive magnet 16, an electromagnetic force acts to pull the drive magnet 16 backward according to Fleming's left-hand rule, and the lens holder 10 moves backward together with the drive magnet 16 as shown in FIG. The wide-angle shooting position is shown in the right half.

  As described above, the lens driving device 1 can perform photographing at two positions, the wide-angle photographing position and the telephoto photographing position. In addition, at the two positions, it is not necessary to pass a current through the drive coils 28 and 30, so that low power consumption is achieved.

  In the example of the dimension data of the first embodiment shown in FIG. 1, the outer diameter of the main body holder 26 of the fixed body 24 is about 15 mm, the height of the fixed body 24 is about 6 mm, and the lens holder 10 is moved. The stroke can be about 0.5 to 1.8 mm. In addition, for switching between wide-angle shooting and telephoto shooting, the drive time for passing a current to the first drive coil 28 and the second drive coil 30 is a minimum of 5 msec.

  In the lens driving device 1 according to the first embodiment, it has been described that the cover member 25 and the main body holder 26 exist as members constituting the frame of the fixed body 24. Further, the rear end member 42 that holds the imaging element 44 is fixed to the pedestal portion 41 that fits and holds with an adhesive 48 or the like. For this reason, in this embodiment, the rear end member 42 and the base portion 41 also form a part of the fixed body 24.

  In the first embodiment shown in FIG. 1 and the like, the flow of magnetic flux from the drive magnet 16 to the first drive coil 28 and the second drive coil 30 is driven by the first drive coil 28 and the second drive coil 30. What is necessary is just to become a direction component required for the drive of the magnet 16. FIG. Accordingly, the drive magnet 16 may be disposed inside the inner diameter of the drive coil, or may be disposed outside the outer diameter of the drive coil. In order to shorten the radial direction, the drive magnet 16 and the two drive coils 28 and 30 are superposed in the direction of the optical axis 11, that is, a configuration in which at least a part thereof is overlapped in the direction of the optical axis 11. It is preferable to do this.

  In this lens driving device 1, engaging portions (guide protrusions 12 b and 12 d) that engage with a guide portion (inner peripheral surface 26 a of the outer wall of the main body holder 26) are arranged outside the driving means, and the lens 13 is disposed on the driving means. Since the lens holder 10 is arranged on the inner side, the portion where the lens holder 10 slides and the lens 13 are located apart from each other. For this reason, it becomes difficult for the sliding powder generated at the sliding portion to adhere to the lens 13. Further, since the lens holder 10 is expanded in diameter to the outside of the driving means and guided by the engaging portion disposed on the outside portion, the guide portion is separated from the center of the lens 13. As a result, it becomes easy to ensure the perpendicularity of the lens 13 to the optical axis 11.

  In this lens driving device 1, the driving magnet 16 abuts on two surfaces in total, that is, the inner peripheral surface of the cylindrical body 12 and the lower surface of the extending portion 17, so that the bonding surface becomes large. For this reason, the fixing of the drive magnet 16 becomes stable over a long period of time. In addition, since the drive magnet 16 is fixed in contact with the extended portion 17 that is easily perpendicular to the optical axis 11, the perpendicularity of the drive magnet 16 to the optical axis 11 is easily obtained. It becomes.

  Moreover, since the guide part which guides the lens holder 10 is comprised by one member, the movement of the optical axis 11 direction of the lens holder 10 can be guided stably. That is, since the inner peripheral surface 26a of the outer wall of the main body holder 26 serving as the guide portion is formed by one member (outer wall), the sliding of the guide protrusions 26b and 26d serving as the engaging portions is stable, and the lens holder 10 is It won't be twisted or bent or hard to slide.

  In the lens driving device 1 of this embodiment, the first and second drive coils 28 and 30 are the same member, and the first and second magnetic pieces 32 and 34 are the same member. For this reason, productivity is improved and cost reduction is achieved. Moreover, since the cylinder 12 and the main body holder 26 are formed of the same material polycarbonate, sliding powder is difficult to be produced. The material may be acrylic or POM instead of polycarbonate.

  Next, the system configuration of the camera 50 including the lens driving device 1 will be described with reference to FIG.

  The camera 50 stores a driver 51 that drives a lens holder 10 having a lens 13 to realize a switching operation, an ISP (Image Signal Processor) 52 that processes an image signal obtained from the image sensor 44, and image data. Storage device 53, control logic unit 54, one or more memories 55 for temporarily storing images for electronic processing, display means 56 for displaying optical images and electronic processed electronic images, and each of these members MPU (Micro Processing Unit) 57 as a system controller for controlling the system.

  Here, the camera module corresponding to the lens driving device 1 includes a mechanical part of the lens driving device 1 including the lens holder 10 including the lens 13, the imaging element 44, a driver 51, and an ISP 52. The control logic unit 54 and the MPU 57 constitute a control unit. The image sensor 44, the ISP 52, and the control unit constitute an image acquisition unit. The MPU 57 serves as a switching command reading unit that reads a switching command, serves as an operation position confirmation unit that confirms the operation position of the lens 13, and also serves as a current position detection unit that detects the position of the lens 13.

  It should be noted that by providing a sensor for detecting the position of the lens 13, that is, the position of the lens holder 10, the sensor may constitute a part of the current position detecting means. The first drive coil 28 or the second drive coil 30 may be used as a sensor. In that case, the first and second drive coils 28 and 30 constitute a part of the current position detecting means.

  Further, the control logic unit 54 may be incorporated in the MPU 57. The display means 56 includes a display element made of liquid crystal and a display driver that drives the display element. The display driver may be arranged in the circuit board 45. The display element may be an LED (Light Emitting Diode), an EL (Electro Luminescent), or other display element. Further, when a plurality of memories 55 are provided as shown in FIG. 7, the digitally zoomed (the image is gradually enlarged or reduced) by performing smoother electronic processing (digital processing) using temporarily stored images. Zooming), and a plurality of images with different resolutions can be combined.

  Such a camera 50 is incorporated in a mobile device such as a mobile phone. In this portable device, sliding powder generated when driving a lens driving device incorporated therein becomes difficult to adhere to the lens, so that the quality of the obtained image can be maintained at a high level. Further, since it becomes easy to ensure the perpendicularity to the optical axis of the lens, distortion of the obtained image is eliminated.

  Next, a lens driving device 1A according to the second embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member same as the member in 1st Embodiment, and the description is abbreviate | omitted or simplified.

  A lens driving device 1 </ b> A according to the second embodiment shown in FIG. 8 mainly includes a lens holder 10 and a fixed body 24. Other main components are the same as those of the lens driving device 1. The difference is that the drive magnet 16 is not fixed to the cylindrical body 12 or the like and can be moved in the direction of the optical axis 11 with respect to the lens holder 10, and the light shielding member and the diaphragm are printed. The filter 43 is not provided on the main body holder 26 and the ring-shaped protrusion 26c is not provided.

  In the lens driving device 1 </ b> A, the driving magnet 16 is not fixed to the cylindrical body 12 and the extending portion 17. A cylindrical regulating member 61 that regulates the movement of the drive magnet 16 is fixed to the imaging side of the inner peripheral surface 26 a of the cylindrical body 12. The restricting member 61 prevents the drive magnet 16 from moving toward the imaging side at the wide angle position. That is, at the wide-angle position, the drive magnet 16 tries to move in the direction of the first magnetic piece 32 due to the magnetic attractive force, but the drive magnet 16 abuts against the regulating member 61, so that further movement is prevented (in the right half of FIG. 8). Status). On the other hand, when the lens holder 10 moves to the subject side, that is, the telephoto position, the drive magnet 16 tries to move further to the second magnetic piece 34 side, but the extension portion 17 prevents the movement (see FIG. The state of the left half of 8).

  Thus, by adopting a configuration in which the drive magnet 16 can move by the distance L, the stroke of the drive magnet 16 can be increased even if the stroke of the lens holder 10 is small. For this reason, even if the drive magnet 16 and the first and second magnetic pieces 32 and 34 are made small and the magnetic attractive force is made small, the position holding force can be made sufficient. This contributes to the downsizing of the lens driving device 1A, and also stabilizes the lens 13 at the time of image acquisition (= photographing) at a wide-angle photographing position or a telephoto photographing position, so that a high-quality image can be obtained.

  A light blocking / aperture 62 is provided so as to cover a part of the extended portion 17 and a part of the lens 13. The light blocking and diaphragm 62 is formed in a ring shape having a width from the center side of the vent hole 17a to the outer edge of the lens 13. The light shielding / stop 62 is formed by printing using carbon-containing ink and has a black shape. In FIG. 8, the light shielding / aperture 62 is shown in the left half, but is not shown in the right half. In place of the light shielding and diaphragm 62, only the light shielding or the diaphragm may be used. When the light shielding member and the diaphragm member are formed as a shielding portion by printing in this way, productivity is increased and cost reduction is achieved.

  In this lens driving device 1A, the filter 43 is not provided in the main body holder 26 but is provided in the rear end member 42 (not shown). However, the filter 43 is not necessarily provided. Further, in the lens driving device 1A, there is no ring-shaped protrusion 26c on the outer peripheral side although the ring-shaped protrusion 26d on the inner peripheral side exists. Since there is no ring-shaped protrusion 26c on the outer peripheral side, there is a risk that the first drive coil 28 will collide with the first magnetic piece 32 when the lens holder 10 is moved, but the assembly of the first drive coil 28 and the first magnetic piece 32 will occur. At times, risks can be avoided sufficiently by taking care not to spread their outer peripheral surfaces.

  Each embodiment of the present invention described above is a preferred example of the present invention, but various modifications can be made without departing from the gist of the present invention. For example, although the cylindrical body 12 is shown integrally with the lens 13, the cylindrical body 12 may be separated from the lens 13.

  Further, the first and second drive coils 28 and 30 serving as driving means are provided so as to be inside the lens holder 10, but the length of the cylindrical body 12 in the optical axis direction is shortened, and It is good also as a structure which arrange | positions a drive means. Further, although the drive magnet 16 is NS magnetized in the radial direction, it may be radial magnetized NS magnetized in the direction of the optical axis 11.

  Further, in the above-described embodiment, the drive magnet 16 is moved together with the lens holder 10, but a drive coil may be used instead of the drive magnet 16. In the case of the drive coil, the magnets arranged on the fixed body 24 side are magnets. Thus, the present invention can be applied to a so-called moving coil system.

  Further, the positioning protrusions 12a and 12c and the guide protrusions 12b and 12d provided on the cylindrical body 12 of the lens holder 10 may not be provided. For example, the guide projection 12b for performing centering on the subject side, the positioning projection 12a for ensuring the tilt accuracy, and the positioning projection 12c for securing the tilt accuracy on the imaging side are provided as described above, and the centering on the imaging side is performed. The guide protrusion 12d to be performed may be eliminated. In this way, the engaging portion is formed only on one side of the lens holder 10 in the optical axis 11 direction, and the lens holder 10 is slid in a cantilevered state, but is abutted at two positions, upper and lower, and tilted with respect to the optical axis 11. Is corrected, the twist of the lens holder 10 is reduced and the movement can be made smooth. Instead of eliminating the guide protrusion 12d, the object-side guide protrusion 12b may be omitted.

  Alternatively, the first drive coil 28 and the first magnetic piece 32 may be integrally formed, and the second drive coil 30 and the second magnetic piece 34 may be integrally formed. Further, a slit is provided in the main body holder 26 instead of the anti-rotation protrusion 26h, a protrusion is provided in the cylindrical body 12 instead of the slit 12e, and the protrusion is inserted into a slit provided in the main body holder 26. It is good as a detent.

  Further, the lead portion of the coil lead wire serving as the terminal wire of the first and second drive coils 28 and 30 may be formed in a slit shape and opened. Further, if necessary, a relief such as a slit may be provided in the cylindrical body 12 serving as the frame portion of the lens 13 so as not to interfere with the lead wire. Further, a land may be provided in the vicinity where the first and second coils 28 and 30 are placed, and electrodes may be provided in advance on the first and second drive coils 28 and 30 to save wiring. In addition, electrodes that contact the electrodes provided in the first and second drive coils 28 and 30 may be provided in the fixed body 24. Further, in that case, either electrode may be elastic or may be supported by an elastic support member. Further, a conductor adhesive may be used at the time of assembly in order to ensure the contact of the electrodes.

  Alternatively, the fixed lens 14 and the lid member 25 may be integrally formed. Further, the cylindrical body 12, the extending portion 17, and the drive magnet 16 may be molded by insert molding. At this time, a drive coil may be used instead of the drive magnet 16. Alternatively, the lid member 25 and the second magnetic piece 34 or the lid member 25, the second magnetic piece 34, and the second drive coil 30 may be molded by insert molding. Similarly, the main body holder 26 and the first magnetic piece 32, or the main body holder 26, the first magnetic piece 32, and the first drive coil 28 may be formed by insert molding. Further, the fixed lens 15 and the main body holder 26 may be integrally molded.

  In addition, the present invention is applicable to any lens that needs to switch the position of the lens 13 to two or more positions. Further, the present invention can be applied not only to intermittent switching but also to continuous switching, that is, an optical zooming mechanism. Specifically, in addition to the case of the above-described two embodiments, as a collapsible mechanism of a collapsible camera that houses a lens barrel in a main body of a camera or a portable device when not in use, or a plurality of focal lengths. The present invention can also be applied to a focal length switching mechanism of a camera that can be switched to a position and a zooming mechanism that continuously displays wide-angle and telephoto images.

  The lens 13 is a single lens, but may be a combination of two lenses or a combination of three or more lenses. Further, although the lenses 13, 14, and 15 are aspherical resin lenses, they may be spherical glass lenses or aspherical glass lenses.

  In addition, although the example in which the lens holder 10 and the fixed body 24 are one each is shown, the lens holder 10 and the fixed body 24 may be arranged so as to overlap two or three or more in the direction of the optical axis 11. Further, the number of the fixed body 24 may be one, and a plurality of sets of the lens holder 10, the fixed body side drive coil, and the like may be provided.

  In each of the above-described embodiments, the example in which the lens driving devices 1 and 1A are incorporated as the mechanism of the camera portion of the camera-equipped mobile phone is shown. However, these lens driving devices and thin cameras are mobile computers, PDAs, and the like. It can be used for other portable devices, or incorporated in other camera devices such as surveillance cameras and medical cameras, and electronic devices such as automobiles and televisions.

  The present invention can be applied to a camera device. Further, the present invention can be applied to a mobile device such as a mobile phone having a camera function. Furthermore, any electronic device having a lens position switching mechanism can be incorporated into all electronic devices.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the lens drive device which concerns on the 1st Embodiment of this invention, (A) is sectional drawing of the lens drive device shown in the state which varied the position of the lens holder on either side, (B) is sectional drawing. It is principal part sectional drawing at the time of changing. It is a figure which shows the lens holder currently used for the lens drive device of FIG. 1, (A) is the sectional view on the AOE line of (B), (B) is the bottom view which looked at (A) from the downward direction. (C) is a cross-sectional view taken along the line C-O-E of (B). It is a top view of the drive magnet used with the lens drive device of FIG. FIG. 2 is a perspective view of the lens driving device (excluding a pedestal, a rear end member, and a diaphragm) in FIG. 1 cut in half. FIG. 2 is an exploded view of the lens driving device (excluding a pedestal, a rear end member, and a diaphragm) in FIG. 1. It is a principal part exploded view of the lens drive device of FIG. It is a block diagram which shows the system configuration | structure of the camera containing the lens drive device of FIG. It is sectional drawing which shows the lens drive device which concerns on the 2nd Embodiment of this invention, and is a figure shown in the state which varied the position of the lens holder on right and left.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Lens drive device 10 Lens holder 11 Optical axis 12 Cylindrical body 12a Positioning protrusion 12b Guide protrusion (engagement part)
12c Positioning protrusion 12d Guide protrusion (engagement part)
12e Slit 13 Lens 14 Fixed lens 15 Fixed lens 16 Driving magnet (part of driving means)
17 Extension part 18 Aperture 24 Fixed body 25 Lid member 26 Main body holder 26a Inner peripheral surface of outer wall (guide part)
28 1st drive coil (a part of drive means)
30 Second drive coil (part of drive means)
32 1st magnetic piece 34 2nd magnetic piece 41 Base part 42 Back end member 43 Filter 44 Image pick-up element 45 Circuit board 50 Camera

Claims (8)

In a lens driving device having a lens holder for holding a lens and driving means for moving the lens holder along the optical axis of the lens,
A guide portion that engages with an engagement portion provided in the lens holder and guides the linear motion along the optical axis in a centered state of the lens holder;
A lens driving device characterized in that the engaging portion is disposed radially outside the driving means, and the lens is disposed radially inside the driving means.   The lens driving device according to claim 1, wherein the engaging portion is guided by the guide portion made of the same member as the engaging portion.   The lens holder has a cylindrical body formed with the engaging portion on the outer periphery and extending in the optical axis direction, and extends substantially perpendicularly from the inner periphery to the inner side in the radial direction to hold the lens in the center. 3. The lens driving device according to claim 1, further comprising: an extending portion, wherein a magnet or a coil as the driving means is held by the inner periphery of the cylindrical body and the extending portion.   A slit extending in the optical axis direction is provided in a part of the cylindrical body, and a non-rotating projection for entering the slit into the main body holder having the guide portion and preventing the lens holder from rotating is provided. The lens driving device according to claim 3.   2. The lens driving device according to claim 1, wherein the lens holder and the lens are integrally molded, and an aperture or a light shielding part is printed on the integrally molded product. In a lens driving device having a lens holder for holding a lens, driving means for moving the lens holder in the optical axis direction of the lens, and a fixed body for holding the lens holder,
The lens holder includes one of a drive magnet and a drive coil among the drive means, and the fixed body includes one of the drive magnet and the drive coil among the drive means, and the drive magnet and The drive coil is arranged in the optical axis direction so that the lens holder can be moved by the mutual magnetic attractive force or magnetic repulsive force,
The fixed body has a guide portion that engages with an engaging portion provided in the lens holder, and guides the linear motion along the optical axis with the lens holder being aligned. A lens driving device, wherein the lens driving device is arranged radially outside the driving means, and the lens is arranged radially inside the driving means. The lens holder includes a drive magnet that can move in the optical axis direction together with the lens,
The fixed body constitutes a magnetic circuit with the drive magnet, and is disposed opposite to the first drive coil and the second drive coil, which are arranged in the optical axis direction of the lens, and the first drive coil and the second drive coil. A first magnetic piece and a second magnetic piece,
When the energization to the first drive coil or the second drive coil is stopped, the lens holder is held in a predetermined position by magnetic attraction between the drive magnet and the first magnetic piece or the second magnetic piece, 7. The lens driving device according to claim 6, wherein the lens holder is moved between the first driving coil and the second driving coil by energizing the first driving coil or the second driving coil.   A camera-equipped portable device comprising: the lens driving device according to claim 1 as a camera unit; and display means for displaying an image obtained by the lens driving device.

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