JP4623714B2 - Camera module and portable terminal using the camera module - Google Patents

Description

  The present invention relates to a camera module, and more particularly, to a small and lightweight camera module and a portable terminal equipped with the camera module.

  In general, a camera module has an autofocus (AF) function and a zoom function. For example, a cylindrical cam is disposed on the side surface of an optical lens, and the zoom lens frame and the AF lens frame are arranged by the cylindrical cam. In this example, a cylindrical cam bearing and a lens frame bearing are arranged on the front cover (fixed frame). A solid-state imaging device (CCD) is directly arranged on the housing (case), a cam for detecting the rotation angle is arranged on the side surface of the cylindrical cam, and the rotation angle of the cylindrical cam is detected by a mechanical switch. (See Patent Document 1).

  In addition, there is an AF lead screw and a zoom lead screw arranged at the corner on one side of the case so that the movable lens group of the zoom lens system can be moved along the lead screw. When the photographic optical system is moved along the optical axis by driving the cam, a normal zooming cam area and a macro shooting cam area are continuously formed on the cam, and the cam is driven by a step motor. Here, a so-called tele-macro two-point switching is used to place a cylindrical cam adjacent to the lens frame, and the AF lens frame and zoom lens frame are driven by this cylindrical cam. The motor is disposed on the side surface of the cylindrical cam.

  In addition, a lead screw is integrally provided in the stepping motor, the lead screw is held by the holding member independently together with the stepping motors 22a and 22b, and an attachment member for attaching these holding members to the box 11 which is the lens barrel base body, There is one that is arranged only on one side with respect to the lead screw. Here, the zoom and AF lens frame is driven by two lead screws, and the guide support portion of the lens frame is provided in the housing, and the housing A CCD is arranged at the bottom.

  In addition, it has a focus motor and zoom motor for driving the photographic lens, and a shutter motor and aperture motor for driving the internal mechanism, and a plane perpendicular to the optical axis of the photographic lens is orthogonal to the optical axis and orthogonal to each other. These motors are arranged in the first to fourth quadrants divided by the first axis and the second axis, respectively, so that the center of rotation of the focus motor and the zoom motor passes through the base of the shutter unit. Some have a notch.

  In addition, a movable lens is driven along the optical axis by a screw shaft, and a bearing portion that rotatably holds the screw shaft on the apparatus main body is integrally formed by molding, and the bearing portion has a plurality of slides having different sliding directions. In some cases, the lens frame for zooming and AF is driven by two lead screws, and the bearings of the two lead screws and the two lens frame guide shafts are supported by the upper housing. The CCD is held in the lower housing.

  By the way, in recent camera modules used for mobile terminals such as mobile phones, high-speed, high-precision autofocus (with a high-resolution solid-state image pickup device (CCD)) as with a normal electronic camera (digital camera) ( AF) function and focal length change (zoom) function are required, and further, the miniaturization and weight reduction of the mobile terminal itself inevitably requires a reduction in the size and weight of the camera module.

  In order to change the autofocus and focal length in such a camera module, it is necessary to move the lens group along the optical axis. Therefore, conventionally, an electromagnetic motor or a pulse motor having a rotor is used. The helicoid mechanism, cam ring, lead screw or the like is driven to move the lens group along the optical axis.

  However, the electromagnetic motor using the above rotor requires an electromagnet and a permanent magnet around the rotor, and a cylindrical portion is indispensable even if the axial length is shortened. It becomes a bottleneck in making it.

For this reason, it has been proposed to use a piezo element as a drive source. For example, a piezoelectric element is disposed close to a rotary feed member for feeding a lens holding frame, and the piezoelectric element is used to step into the rotary feed member. Here, the piezoelectric element is arranged close to the circumference of the end of the feed screw for driving the lens frame (see Patent Document 2).

  In addition, two types of piezoelectric elements are integrally attached to a guide member that guides the lens holding frame, and these piezoelectric elements are alternately expanded and contracted to cause an intermittent feed operation to the guide member. Here, the piezoelectric element is arranged at the end of the feed screw for driving the lens holding frame (see Patent Document 3).

  In addition, an electromechanical energy conversion element (piezoelectric element) that vibrates when an electric signal is applied is brought into contact with an output member having a screw portion, and the output member is rotated by vibration of the conversion element. There is one that moves the moving member in the axial direction of the output member along with the rotation of the screw part by bringing the moving member into contact with the screw part, and here, around the cylindrical part at the end of the feed screw A piezoelectric element is disposed (see Patent Document 4).

  In addition, a sleeve portion integral with the lens barrel is slidably fitted to the guide bar, and a vibrator of a linear drive type vibration wave actuator is pressed against the outer peripheral surface of the sleeve portion with a leaf spring, so that the piezoelectric element is predetermined. There is one in which two alternating voltages having a phase difference of 2 are applied, axial thrust is applied to the sleeve portion, and the lens barrel is moved along the optical axis (see Patent Document 5).

  For each moving lens frame, one ceramic vibrator is arranged in either the moving lens frame or the fixed portion (lens barrel) of the lens device, and the ceramic vibrator is not arranged. There is a type in which a ceramic vibrator is pressed against a part of either the moving lens frame or the fixed portion, and the lens is driven by an elliptical motion of the ceramic vibrator.

  Further, a lens holding frame is screwed into a threaded portion of a drive shaft provided so as to be rotatable around the shaft, a vibrating body provided with a piezoelectric element is brought into contact with a peripheral surface of the driving shaft, and the drive shaft is vibrated by the vibrating body. In some cases, the lens holding frame is driven to move forward and backward along the axial direction of the drive shaft.

  The drive source using a piezo element (piezoelectric element) is low speed, but has high torque, excellent response and controllability, can be positioned very finely, and has a holding torque (or holding force) when not energized, quietness And has advantages such as being small and light. And as a drive source using a piezo element, for example, it is provided with at least one rectangular piezoelectric plate 10 having a long edge part and a short edge part and first and second faces, Attach the electrode and attach a ceramic spacer to the center of the first edge of the edge, and apply elastic force to the center of the second edge opposite to the first edge to attach the ceramic spacer to the object There is one in which either an alternating current or an asymmetric single-pole pulse voltage is applied to the electrode (see Patent Document 6).

  Further, as a driving source using a piezoelectric element, first and second long sides, first and second short sides, front and back surfaces surrounded by long and short sides, a plurality of electrodes connected to the front surface, and A first piezoelectric plate having a counter electrode connected to the back surface is provided, and is connected to the front and back surfaces surrounded by the first and second long sides, the first and second short sides, the long side and the short side, and the front surface. A second piezoelectric plate having a plurality of electrodes and a counter electrode connected to the back surface, the first spacer being attached to the first long side at one end near the first short side of the first piezoelectric plate, The second spacer is attached to the first long side at one end near the first short side of the second piezoelectric plate and engaged with the surface of the object, and each spacer is pressed against the surface of the object, An excitation voltage is applied to the plurality of electrodes, and the first short side of the first piezoelectric plate is moved to the second pressure. The first short side of the plate is that so as to substantially parallel to and close (see Patent Document 7).

  In addition, it has a piezoelectric plate with a spacer attached to one of the two long edge portions, two short edge portions, and the long edge portion as a driving source using a piezo element, and can rotate around the axis. At least one arm, and the arm is provided with first and second ends provided at both ends thereof spaced apart from the axis, a read / write head attached to the first end of the arm, and a second There is a structure in which a rigid member is provided on the end portion, and a spacer of the piezoelectric plate is elastically biased by the rigid member so that the piezoelectric plate is movable with respect to the axis (see Patent Document 8). .

  Similarly, as a drive source using a piezo element, a plurality of electrodes are provided on one surface of the piezoelectric plate, a counter electrode is provided on the other surface, a head is provided at one end of an arm that can be swung around an axis, There is one in which a rigid body is provided at the other end so that the piezoelectric plate is elastically biased toward the rigid body (see Patent Document 9).

  Further, as a driving source using a piezo element, the piezo element moves in the first direction when a voltage is applied between the first electrode group and the common electrode, and between the second electrode group and the common electrode. When a voltage is applied to the first and second electrode groups, the first electrode group and the second electrode group are connected to a low voltage by a switch so as to selectively move in the first or second direction. (See Patent Document 10).

  In addition, as a driving source using a piezo element, the vibrator has a rectangular parallelepiped shape formed of a plurality of thin layers made of piezoelectric material, and this layer has the same first and second relatively large square mains. The main surface is defined from a long end surface and a short end surface, the layers are stacked and the main surfaces are bonded together, the electrode is on the surface of the layer, and the contact region is one or more of the layers There is one which is arranged on an end face and applies a voltage to an electrode in order to excite vibration in a contact region (see Patent Document 11).

JP 7-63970 A Japanese Patent Laid-Open No. 4-291213 JP-A-4-221910 JP-A-8-47273 JP-A-7-104166 JP-A-7-184382 Japanese Patent No. 2980541 JP 9-37575 A JP 2000-40313 A Special table 2002-529037 gazette Special table 2003-501988 gazette

  By the way, in a camera module used for a portable terminal such as a mobile phone, downsizing is always required. To apply to such a portable terminal, the driving mechanism must be downsized. In a conventional camera module, Even if a piezo element is used, since the lens holding member is moved by the slider, there is a problem that it is difficult to make the lens compact and the configuration becomes complicated.

  In view of the above circumstances, an object of the present invention is to provide a camera module that can be configured to be small and light even if an autofocus (AF) function and a zoom function are incorporated using a piezoelectric element.

In order to solve the above problems, a camera module according to the present invention includes a first lens holding unit that holds at least one optical lens, a second lens holding unit that holds at least one optical lens, A first lead screw that engages with the first lens holding portion to move the first lens holding portion along the optical axis, and is disposed substantially parallel to the optical axis, and the second A second lead screw that engages with the lens holding portion to move the second lens holding portion along the optical axis, and is arranged substantially parallel to the optical axis; and the first lead screw; A first rotor configured to be concentric and substantially cylindrical and having an outer diameter larger than that of the first lead screw and rotating integrally with the first lead screw; and the second lead screw. And concentric It consists of a substantially cylindrical shape, and, the second having a larger outer diameter than the lead screw, the second rotor of the second lead screw and integrally rotated, the first operating portion on the end portion And the first actuating part abuts the first rotor from a direction substantially orthogonal to the optical axis , thereby applying a rotational driving force to the first lead screw when energized and the non-energized state. A first piezo element for applying a holding torque to the first lead screw and a second operating part at the end, and the second operating part is substantially perpendicular to the optical axis of the second rotor. by more contacts, and a second piezoelectric element for imparting holding torque to said second lead screw when not energized with imparting rotational driving force to said second lead screw when energized.

In the present invention, the first rotor is disposed substantially end portion of the front Symbol first lead screw,
It said second rotor is disposed substantially end portion of the front Stories second lead screw.

  In the present invention, the first piezo element drives the first lead screw by bringing the first operating portion into contact with the substantially cylindrical outer peripheral surface of the first rotor, and the second piezoelectric element. The piezo element drives the second lead screw by bringing the second operating portion into contact with the substantially cylindrical outer peripheral surface of the second rotor.

  In the present invention, the first piezo element and the second piezo element each have a substantially longitudinal shape, and the first piezo element and the second piezo element are arranged in the longitudinal direction of the longitudinal shape. It arrange | positions so that it may become a direction substantially orthogonal to an optical axis.

  In the present invention, the first piezo element and the second piezo element are arranged such that the longitudinal directions of the respective longitudinal shapes are substantially parallel to each other, and the optical axis is located approximately in the middle between the two piezo elements.

The present in invention, a to a camera module, such a substantially cubic shape, so that the said first piezoelectric element and the second piezoelectric element and the first actuating unit and the second actuating portion is in the same direction A camera module is obtained in which the first lead screw and the second lead screw are arranged on the side surface side of the cubic shape.

  The present invention further includes a guide shaft member disposed between the first lead screw and the second lead screw while guiding the first lens holding portion and the second lens holding portion.

According to the present invention, there is provided a to the camera module, such a substantially cubic shape, said first piezoelectric element and said second piezoelectric element and the first actuating unit and the second actuating portion is substantially opposite directions The first lead screw is arranged on one side of the substantially cubic shape, and the second lead screw is arranged on the other side facing the one side of the substantially cubic shape. Camera module is obtained.

  In the present invention, the first lens holding portion and the second lens holding portion are guided, and further include a guide shaft member disposed on the one side surface or the other surface side, and at least one or more guide shaft members are included. A third lens holding unit that holds the optical lens and rotatably holds the first lead screw and the second lead screw, and rotates the first lead screw and the second lead screw. And a base portion that is movably held.

  In the present invention, the base portion further holds the first piezo element and the second piezo element, and includes an image pickup element and a substrate holding the image pickup element provided on the lower surface of the base portion. In addition.

According to the present invention, a first lens holding unit that holds at least one or more optical lenses, a second lens holding unit that holds at least one or more optical lenses, and the first lens holding unit, Engage with the first lens holding portion to be movable along the optical axis, and engage with the first lead screw disposed substantially parallel to the optical axis and the second lens holding portion. The second lens holding portion is configured to be movable along the optical axis, and is configured by a second lead screw disposed substantially parallel to the optical axis, and a substantially cylindrical shape concentric with the first lead screw. And a first rotor having an outer diameter larger than that of the first lead screw and rotating integrally with the first lead screw, and a substantially cylindrical shape concentric with the second lead screw. And the second re- Has a larger outer diameter than the de screw, a second rotor which said second lead screw and integrally rotated, provided with a first operating portion at the end portion, the actuating portion of the first is the first by abutting than a direction substantially perpendicular to the optical axis 1 of the rotor, the imparting holding torque to said first lead screw when not energized with imparting rotational driving force to said first lead screw when energized 1 The second lead is provided with a second actuating part at the end, and the second actuating part comes into contact with the second rotor from a direction substantially perpendicular to the optical axis , thereby energizing the second lead. a camera module and a second piezoelectric element for imparting holding torque to said second lead screw when not energized with imparting rotational drive force to the screw, and the operation member, a display member, the battery A portable terminal comprising: a communication unit; and a housing that houses the camera module, the display member, the battery, and the communication unit, and that has a thickness dimension substantially limited to the height of the camera module. Is obtained.

  As described above, in the present invention, the first and second piezo elements are provided, and the first piezo element is in the optical axis direction by pressing the operating portion of the first piezo element against the outer peripheral surface of the first rotor. The second piezo element extends in the same direction as the first piezo element by pressing the operating portion of the second piezo element against the outer peripheral surface of the second rotor. Therefore, the drive mechanism for driving the first and second lens holding portions can be simplified, and the camera module when the autofocus (AF) function and the zoom function are incorporated can be configured to be small and lightweight.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  Referring to FIGS. 1 and 2, FIG. 1 is a perspective view showing an example of a camera module according to Embodiment 1 of the present invention with a camera frame (camera housing) omitted, and FIG. It is a perspective view which shows the camera module by Example 1 from another angle in the state which abbreviate | omitted the camera frame.

  The illustrated camera module 10 includes a CCD 11, which is mounted on a wiring board 11a. Then, the light received by the light receiving surface of the CCD 11 through the optical lens system 12 is converted into an electric signal by the CCD 11. As shown in the drawing, the camera module 10 has a pair of guide shafts 13 and 14, and the first and second lens holders 15 and 16 are slidably supported on the guide shafts 13 and 14, respectively. The first and second lens holders 15 and 16 are guided by guide shafts 13 and 14 and are movable along the optical axis.

  The first and second lens holders 15 and 16 hold at least one optical lens. Further, a third lens holder 17 having at least one optical lens is disposed on the upper side of the second lens holder 16 (that is, the subject side) (FIG. 1 shows only the optical lens). However, the code | symbol 17 shall show the 3rd lens holder holding an optical lens).

  As shown in the figure, a first lead screw 18 is disposed substantially parallel to the optical axis, and this first lead screw 18 is engaged with the first lens holder 15 by a cam body 18a, as will be described later. Thus, when the first lead screw 18 is driven to rotate, the first lens holder 15 moves along the optical axis. Similarly, a second lead screw 19 is disposed substantially parallel to the optical axis, and this second lead screw 19 is engaged with the second lens holder 16 by a cam body 19a, as will be described later. When the second lead screw 19 is rotationally driven, the second lens holder 16 moves along the optical axis.

  A columnar (disc-shaped) first rotor 20 is attached to the lower end (end opposite to the subject side end) of the first lead screw 18 (the first rotor 20 is the first rotor 20). The actuating portion 21 a of the first piezo element 21 is in contact with the outer peripheral surface of the first rotor 20. The first piezo element 21 extends on the substrate 11a in a plane substantially orthogonal to the optical axis direction, and the operation of the first piezo element 21 causes the first rotor 20 to rotate. As a result, the first lead screw 18 rotates and the first lens holder 15 moves along the optical axis.

  A cylindrical (disc-shaped) second rotor 22 is attached to the lower end of the second lead screw 19 (the second rotor 22 is concentric with the second lead screw 19). ) The operating portion 23 a of the second piezo element 23 is in contact with the outer peripheral surface of the second rotor 22. The second piezo element 23 extends in the same direction as the first piezo element 21. That is, the second piezo element 23 extends on the substrate 11a in a plane substantially perpendicular to the optical axis direction, and the second rotor 22 is rotated by the operation of the second piezo element 23. As a result, the second lead screw 19 rotates and the second lens holder 16 moves along the optical axis.

  3 to 5, FIG. 3 is a diagram of the camera module 10 as viewed from above with the upper body excluding the camera frame, and FIG. 4 is a diagram of the camera module 10 as viewed from the side. FIG. 5 is a view of FIG. 4 viewed from the side at another angle.

  Although not shown, the substantially cubic camera frame is formed of, for example, fluorine-containing polycarbonate. The camera frame has a bearing portion (see FIG. 1) for supporting the first lead screw 18 and the second lead screw 19. (Not shown) is formed, and the first lead screw 18 is supported by a bearing portion (not shown) so as to be rotatable between the upper surface and the lower surface of the camera frame. An optical sensor (light emitting element and light receiving element) is attached to the side surface of the camera frame, and the optical sensor detects the reference position of the optical lens system 12 and the amount of movement from the reference position. A third lens holder 17 is attached to the upper surface of the camera frame.

  Although not shown, the first piezo element 21 is biased toward the first rotor 20 by a coil spring, and the second piezo element 23 is biased toward the second rotor 22 by a coil spring. As a result, when the first piezo element 21 is excited, high-order bending vibration is generated in the operating portion 21a and a traveling wave is generated. Then, a frictional force is generated between the first rotor 20 with which the operating portion 21a is pressed and the operating portion 21a, and the first rotor 20 is rotationally driven by this frictional force (for example, Japanese Patent No. 2980541 and the special patent Table 2002-529037).

  As described above, the cam body 18 a is formed on the outer peripheral surface of the first lead screw 18, and similarly, the cam body 19 a is also formed on the second lead screw 19. As described above, when the first piezo element 21 and the second piezo element 23 are excited, the first rotor 20 and the second rotor 22 are rotationally driven. The rotation directions of the first rotor 20 and the second rotor 22 are changed by changing the direction of the voltage applied to the first piezo element 21 and the second piezo element 23.

  The first and second lead screws 18 and 19 are rotated by the rotation of the first rotor 20 and the second rotor 22, respectively, whereby the first and second lead screws 18 and 19 are respectively rotated according to the rotation of the cam bodies 18a and 19a. Lens holders 15 and 16 move along the optical axis. For example, detection lines 20a extending in the axial direction are formed at predetermined intervals on the outer peripheral surface of the first rotor 20, and the optical sensor irradiates light from the light emitting element to the outer peripheral surface of the first rotor 20. Reflected light from the outer peripheral surface of the first rotor 20 is received by the light receiving element. Since the rotation angle can be detected based on the number of repetitions for detecting the detection line 20a, the control unit (not shown) can rotate the first rotor 20 according to the number of repetitions of the received detection line 20a, that is, the first number. The amount of movement of the lens holder 15 is grasped.

  Similarly, the amount of rotation of the second rotor 22 is detected by an optical sensor (not shown) provided corresponding to the second rotor, and the first and second lens holders are detected as described above. Focusing and zooming are performed by relatively driving 15 and 16 along the optical axis to change the relative positions of the first and second lens holders 15 and 16.

  In the camera module 10 shown in the first embodiment, when the first lens holder 15 and the second lens holder 16 are on the wide-angle (wide) side, as shown in FIG. When away from the holder 17 and set to the telephoto (telephoto) side, it approaches the third lens holder 17 as shown in FIG. Then, in correspondence with the lens holder positions shown in FIGS. 6 (a) and 6 (b), the position of each lens group and the movement range for focusing are shown in FIG. 6 (c). For focusing, for example, in the case of the wide-angle (wide) side in FIG. 6A, the lens holder 15 in FIG. In the case of the (tele) side, the range indicated by symbol B in FIG.

  That is, as shown in FIGS. 7A and 7B, the third lens holder 17 is fixedly arranged, and the first and second lens holders 15 and 16 move to the guide shafts 13 and 14. Supported as possible. When the second lens holder 16 moves to the third lens holder 17 side, a telephoto state is established. Following the movement of the second lens holder 16, the first lens holder 15 also moves to the third lens holder 17 side. Move (refer to FIG. 7A: At this time, during AF, it moves within a scanning range defined by telephoto). On the other hand, when the second lens holder 16 is returned to the first lens holder 15 side, a wide-angle state is established, and the first lens holder 16 also moves following the movement of the second lens holder 16 (FIG. (Refer to 7 (b): At this time, during AF, it moves within a scan range defined by a wide angle).

  For example, as shown in FIG. 8, the first piezo element 21 described above is formed in a substantially rectangular shape, and a first surface 211 formed in the longitudinal direction and the short direction, and a second side opposite thereto. An electrode (not shown) is provided on the surface 212, and a spacer (actuating portion) 21a that is engaged with an object that is moved relative to the third surface 213 in the lateral direction is provided, and the first surface 211 and the second surface A reciprocating motion is generated in the operating portion 26a by applying a sinusoidal voltage to the electrode provided at 212, thereby realizing a relative movement with respect to the object with which the operating portion 21a is engaged. Thus, since the first piezo element 21 is a friction drive type, the torque is low, but the torque is excellent and the response and controllability are excellent, the positioning is possible, and the holding torque (or holding force) when no current is applied. The second piezo element 23 has the same advantages as the first piezo element 21. In addition, the second piezo element 23 has the same structure as the first piezo element 21.

With reference to FIG. 9, here, a holding member for holding the first and second piezo elements 21 and 23, and a mechanism for rotatably supporting the guide shafts 13 and 14 and the lead screws 18 and 19 will be described. Although not shown in FIGS. 1 and 2, on the substrate 11a is disposed the base member 40, first and second piezoelectric element holding member 41 and 42 on the base member 4 0 is provided Has been. The first piezo element holding member 41 has a hollow rectangular parallelepiped shape, and a support protrusion 41a is formed on the inner wall thereof, and the first piezo element 21 is made to be a first piezo element holding member by the support protrusion 41a. 41 is supported. The surface of the first piezo element holding member 41 facing the first rotor 20 is opened, and the operating portion 21a protrudes from the opening surface and is pressed against the outer peripheral surface of the first rotor 20. . The second piezo element holding member 42 is also configured in the same manner as the first piezo element holding member 41, and the second piezo element 23 is held in the second piezo element holding member 42 by the support protrusion 42a. The part 23 a is in pressure contact with the outer peripheral surface of the second rotor 22.

  Referring also to FIG. 10, although not shown in FIGS. 1 and 2, the third lens holder 17 has a frame body 17b for holding the lens 17a, and the first and second frames 17b are attached to the frame body 17b. The upper ends of the lead screws 18 and 19 are rotatably supported by bearing portions 43 and 44, and the upper ends of the guide shafts 13 and 14 are supported by the frame body 17b. Further, the lower ends of the first and second lead screws 18 and 19 are rotatably supported by the base member 40, and the lower ends of the guide shafts 13 and 14 are supported by the base member 40. Then, the assembled body assembled as described above is housed in the case 45 and becomes the camera module 10 as shown in FIG.

  Referring to FIG. 12, FIG. 12 is a diagram for explaining the operation principle of the first piezo element 21. As described above, the first piezo element 21 is formed by the first piezo element support portion 41. The first piezo element 21 is urged toward the first rotor 20 by the first piezo element support portion 41, and the operating portion 21 a of the first piezo element 21 is moved to the first rotor 20. It is pressed against the outer peripheral surface (see FIGS. 12A and 12B). As a result, when the first piezo element 21 is excited, as shown in FIGS. 12C and 12D, the first piezo element 21 performs a bending motion, and operates with the first rotor 20 by this bending motion. The first rotor 20 is rotated by the frictional force generated between the portion 21a. Since the first piezo element 21 is bent in a direction intersecting the optical axis, it is desirable to hold the first piezo element 21 at two positions on the side surface.

  As is clear from the above description, the first and second piezo elements 21 and 23 are each formed in a substantially longitudinal shape, and the first and second piezo elements 21 and 22 are perpendicular to the optical axis in the length direction. Are arranged so that their length directions are parallel to each other, and the optical axis is located approximately in the middle of both piezoelectric elements. The first and second piezo elements 21 and 22 are arranged so that the first and second operating parts 21a and 23a are in the same direction. The first and second lead screws 18 and 19 are arranged on one side of the cubic case 45.

  With reference to FIGS. 13 and 14, another example of the camera module 10 according to the present invention will be described. 13 and 14, the same components as those in FIGS. 9 and 10 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 13, the base member 40, the frame body 17b, and the first and second piezo element holding members 41 and 42 are omitted, but as described with reference to FIGS. The second piezo elements 21 and 23 are held by first and second piezo element holding members 41 and 42, respectively. The first and second lead screws 18 and 19 are interposed between the frame body 17b and the base member 40. The guide shafts 13 and 14 are supported so as to be rotatable, and are supported between the frame body 17 b and the base member 40.

  As shown in FIGS. 13 and 14, the first and second piezo elements 21 and 23 are disposed on the base member 40 so that the operating portions 21a and 23a are in opposite directions, and the first lead screw 18 is moved. When arranged on one side of the cubic case 45 (not shown in FIGS. 13 and 14), the second lead screw 19 is arranged on the other side facing the one side of the cubic case. .

  In this way, the first and second piezo elements 21 and 23 may be arranged on the base member 40 so that the operating portions 21a and 23a are in opposite directions. The second piezoelectric elements 21 and 23 may be arranged on the base member 40 so that the longitudinal direction thereof is perpendicular to the optical axis.

  The above-described camera module is incorporated into a mobile terminal, for example. FIG. 15 is a plan view showing a mobile phone 50 as an example of a mobile terminal in a state (open state) in which an operation unit (operation member) 51 and a display (display member) 52 can be seen. The first case portion 53 on which 51 is mounted and the second case portion 54 on which the display 52 is mounted are connected by a hinge mechanism 55, and the first and second case portions 53 and 54 are arranged around the hinge mechanism 55. Can be rotated. In addition, the 1st and 2nd case parts 53 and 54 comprise a case body.

  The second case 54 incorporates the above-described camera module 56 as indicated by a broken double circle in the figure. When a predetermined button of the operation unit 51 is operated, the camera module 56 takes an image, An image captured by the camera module 56 is displayed on the display 52, for example. Note that the upper side of the camera module 56 shown in FIG. 1 is directed to the outside of the second case portion 54.

  That is, the second case portion 54 has an opening for exposing the optical lens held by the third lens holder 17 of the camera module 56. Although not shown, the first case portion 53 accommodates a battery, a communication portion, and the like. Further, the thickness dimension of the second case portion 54 is substantially regulated by the height of the camera module 56. Yes.

  In this way, the first and second lens holders 15 and 16 are driven along the optical axis using the first and second piezo elements, respectively. Therefore, the first and second lens holders 15 are driven. And 16, that is, the structure of the lens moving mechanism when driving the optical lens system becomes extremely simple, and even if an autofocus (AF) function and a zoom function are incorporated, the camera module can be reduced in size and weight.

  The first and second piezoelectric elements are provided, and the first piezoelectric element extends in a plane substantially orthogonal to the optical axis by pressing the operating portion of the first piezoelectric element to the outer peripheral surface of the first rotor. The second piezoelectric element extends in the same direction as the first piezoelectric element by pressing the operating portion of the second piezoelectric element against the outer peripheral surface of the second rotor. The camera can be mounted on a portable terminal as a result of being able to simplify the drive mechanism that drives the lens holder and reducing the number of components and reducing the size and weight of the camera module even if the autofocus (AF) function and zoom function are incorporated. Applicable to modules.

1 is a perspective view schematically showing an example of a camera module according to Embodiment 1 of the present invention with a camera frame (camera housing) omitted. It is a perspective view which shows the camera module shown in FIG. 1 from another angle. It is the figure which looked at the camera module by Example 1 of this invention from upper direction. It is the figure which looked at the camera module by Example 1 of this invention from the side. It is a side view which shows the camera module shown in FIG. 4 from another angle. It is a figure for demonstrating the movement of the lens group which comprises the optical system in the camera module by Example 1 of this invention, (a) is a figure which shows the state which has a lens group in the wide angle (wide) side, (b). FIG. 6 is a diagram illustrating a state in which the lens group is on the telephoto (tele) side, and FIG. 5C is a diagram for explaining a moving range of the focusing lens on the telephoto side and the wide angle side. 4A and 4B are diagrams for explaining movement of a lens group constituting an optical system in the camera module according to Embodiment 1 of the present invention, where FIG. 5A is a diagram illustrating a telephoto state, and FIG. It is a perspective view which shows the shape of the piezoelectric element used in Example 1 of this invention. It is a perspective view which shows holding | maintenance of a piezoelectric element, and support of a lead screw and a guide shaft from diagonally upward. It is a perspective view which shows holding | maintenance of a piezoelectric element, and support of a lead screw and a guide shaft from diagonally downward. It is a perspective view which shows a camera module in the state accommodated in the case. It is a figure for demonstrating operation | movement of the piezo element used in Example 1 of this invention, (a) and (b) are figures which show the support of a piezo element, (c) and (d) are the bending | flexion of a piezo element. It is a figure which shows exercise | movement. It is a perspective view for demonstrating the other example of arrangement | positioning of a piezo element. It is a top view for demonstrating the other example of arrangement | positioning of a piezo element. It is a figure which shows roughly an example of the mobile telephone incorporating the camera module by this invention.

Explanation of symbols

10 Camera module 11 CCD
13, 14 Guide shafts 15, 16, 17 Lens holders 18, 19 Lead screws 20, 22 Rotors 21, 23 Piezo elements

Claims (13)

A first lens holding unit for holding at least one optical lens;
A second lens holding unit for holding at least one optical lens;
A first lead screw that engages with the first lens holding portion to allow the first lens holding portion to move along the optical axis, and is disposed substantially parallel to the optical axis;
A second lead screw that engages with the second lens holding portion to move the second lens holding portion along the optical axis, and is arranged substantially parallel to the optical axis;
A first rotor configured in a substantially cylindrical shape concentric with the first lead screw, having a larger outer diameter than the first lead screw, and rotating integrally with the first lead screw; ,
A second rotor configured in a substantially cylindrical shape concentric with the second lead screw, having a larger outer diameter than the second lead screw, and rotating integrally with the second lead screw; ,
A first actuating part is provided at the end, and the first actuating part comes into contact with the first rotor from a direction substantially perpendicular to the optical axis, whereby a rotational driving force is applied to the first lead screw during energization. And a first piezo element that applies a holding torque to the first lead screw when not energized ,
A second actuating part is provided at the end, and the second actuating part comes into contact with the second rotor from a direction substantially orthogonal to the optical axis, whereby a rotational driving force is applied to the second lead screw during energization. And a second piezo element that applies a holding torque to the second lead screw when no current is applied . It said first rotor is disposed substantially end portion of the front Symbol first lead screw,
It said second rotor camera module according to claim 1, wherein arranged in substantially end portion of the front Stories second lead screw. The first piezo element drives the first lead screw by bringing the first operating portion into contact with the substantially cylindrical outer peripheral surface of the first rotor,
3. The camera according to claim 1, wherein the second piezo element drives the second lead screw by bringing the second operating portion into contact with the substantially cylindrical outer peripheral surface of the second rotor. module. Each of the first piezo element and the second piezo element has a substantially longitudinal shape,
The camera module according to claim 1, wherein the first piezo element and the second piezo element are arranged such that a length direction of each of the longitudinal shapes is substantially perpendicular to an optical axis.   The first piezoelectric element and the second piezoelectric element are arranged such that the lengthwise directions of the respective longitudinal shapes are substantially parallel to each other and the optical axis is positioned approximately in the middle of both piezoelectric elements. The camera module according to any one of the above. A to the camera module, such a substantially cubic shape,
The first piezo element and the second piezo element are arranged so that the first operating part and the second operating part are in the same direction,
The camera module according to claim 1, wherein the first lead screw and the second lead screw are arranged on one side of the cubic shape.   The camera module according to claim 6, further comprising a guide shaft member disposed between the first lead screw and the second lead screw while guiding the first lens holding portion and the second lens holding portion. . A to the camera module, such a substantially cubic shape,
The first piezo element and the second piezo element are arranged so that the first actuating part and the second actuating part are substantially opposite to each other;
The first lead screw is disposed on one side of the substantially cubic shape;
The camera module according to claim 1, wherein the second lead screw is disposed on the other surface side facing the one side surface of the substantially cubic shape.   The camera module according to claim 7, further comprising a guide shaft member that guides the first lens holding portion and the second lens holding portion and is disposed on the one side surface or the other surface side. A third lens holding portion that holds at least one optical lens and rotatably holds the first lead screw and the second lead screw;
The camera module according to claim 1, further comprising a base portion that rotatably holds the first lead screw and the second lead screw.   The camera module according to claim 10, wherein the base portion further holds the first piezo element and the second piezo element.   The camera module according to claim 10 or 11, further comprising an image sensor and a substrate provided on a lower surface of the base portion and holding the image sensor. A first lens holding part that holds at least one optical lens, a second lens holding part that holds at least one optical lens, and the first lens holding part engaged with the first lens holding part. The first lens holding portion can be moved along the optical axis, and the first lead screw disposed substantially parallel to the optical axis and the second lens holding portion are engaged with the second lens holding portion. The first lead screw and a second lead screw arranged substantially parallel to the optical axis, and a substantially cylindrical shape concentric with the first lead screw, and the first lead screw A first rotor having an outer diameter larger than that of the first lead screw, the first rotor rotating integrally with the first lead screw, a substantially cylindrical shape concentric with the second lead screw, and the first 2 lead screw Large has an outer diameter, wherein the second rotor to the second lead screw and integrally rotated, provided with a first operating portion at the end portion, the actuating portion of the first said first rotor by abutting than a direction substantially perpendicular to the optical axis, a first piezoelectric element for imparting holding torque to said first lead screw when not energized with imparting rotational driving force to said first lead screw when energized And a second actuating part at the end, and the second actuating part contacts the second rotor from a direction substantially perpendicular to the optical axis , thereby rotating the second lead screw when energized. A camera module including a second piezo element that applies a driving force and applies a holding torque to the second lead screw when no current is applied;
An operation member, a display member, a battery, a communication unit,
A portable terminal comprising: a housing that houses the camera module, the display member, the battery, and the communication unit, and that has a thickness dimension substantially limited to a height of the camera module.

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