JP4484652B2 - 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 case, 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 disposed 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, stepping is performed by arranging a cylindrical cam adjacent to the lens frame by so-called two-point switching between tele and macro, and driving the AF lens frame and the zoom lens frame 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, a piezoelectric element is provided in contact with the circumference of an end of a feed screw for driving a 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, 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 for holding 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 arranged in parallel with the optical axis;
A second lens holding portion that engages with the second lens holding portion to move the second lens holding portion along the optical axis, and is disposed at a position that is symmetrical with the first lead screw with respect to the optical axis. Lead screw,
A first piezo element having a rectangular plate-like outer shape and having an operating portion at an end;
A second piezo element having a rectangular plate-like outer shape and having an operating portion at an end;
A first rotor that rotates integrally with the first lead screw and receives a driving force by contact with the first piezoelectric element;
A second rotor that rotates integrally with the second lead screw and receives a driving force by contact with the second piezoelectric element;
A first holding unit for holding the first piezo element at two positions on a side surface of the piezo element in parallel and close to the first lead screw to drive the first rotor;
Said second lead screw parallel and proximate to said second piezoelectric element for driving the second rotor and a second holding portion for holding in two places in the side face of the piezoelectric element, wherein The first and second piezo elements are driven while detecting the rotation angles of the first and second rotors, and the relative positions of the first lens holding part and the second lens holding part in the optical axis direction are determined. This is characterized in that focusing and zooming are performed .

In the present invention, the first rotor has a cylindrical shape concentric with the first lead screw , and is disposed at an end portion of the first lead screw, and the second rotor is the second lead screw. It is arranged in an end portion of the second lead screw as well as and the concentric cylindrical.

  The present invention further includes a guide portion that urges the operating portion of the first piezo element that drives the first rotor so as to abut against the first rotor.

In the present invention, a bearing portion that pivotally supports both the first lead screw and the second lead screw;
A storage portion for storing the first lens holding portion and the second lens holding portion;
And a cubic case portion having a third lens holding portion for holding at least one optical lens. In the present invention, the guide part and the urging means are arranged in the case part.

  According to the present invention, there is provided a camera module that further includes an image sensor and a substrate that is provided on a lower surface of the case portion and holds the image sensor, wherein the third lens holding portion is disposed on the upper surface of the case portion. can get.

Furthermore, according to the present invention, a first lens holding unit that holds at least one optical lens, a second lens holding unit that holds at least one optical lens, and at least one optical lens. A third lens holding portion for holding the lens, a cubic camera case portion, and the first lens holding portion to engage with the first lens holding portion so as to be movable along the optical axis. The first lead screw disposed parallel to the optical axis and the second lens holding portion are engaged to enable the second lens holding portion to move along the optical axis, and with respect to the optical axis, and a second lead screw disposed in a position where the first lead screw and symmetrical, the first piezoelectric element including an actuation portion on the end portion has a plate-like outer shape of a rectangular, plate-like outer shape of a rectangular A second comprising an actuating part at the end; A first rotor that rotates integrally with the first element and the first lead screw and receives a driving force by contact with the first piezoelectric element, and a second rotor that rotates integrally with the second lead screw. A second rotor that moves and receives a driving force by contact with the second piezo element; and the first rotor that is parallel to and close to the first lead screw for driving the first rotor. A first holding unit that holds the piezo element at two positions on the side surface of the piezo element, and the second piezo element in parallel with and close to the second lead screw for driving the second rotor. the and a second holding portion for holding at two locations on the side surface of the piezoelectric element, by driving the first and second piezoelectric element while detecting the rotation angle of the first and second rotors, the first By changing the relative position in the direction of the optical axis of the lens holding portion and second lens holding portion, and a camera module focus and zoom are performed,
An operation member, a display member, a battery, a communication unit,
It said camera module, wherein the display member, the portable terminal is obtained which; and a housing which is limited to the height of the camera module thickness while accommodating the battery and the communication unit.

  As described above, in the present invention, the first and second piezo elements are provided, the first and second piezo elements are brought into contact with the first and second rotors, respectively, and the first and second rotors are provided. And the first and second lead screws are rotated to drive the first and second lens holders along the optical axis, so that an autofocus (AF) function and a zoom function are provided. There is an effect that the camera module when incorporating 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.

  FIG. 1 is a perspective view showing an example of a camera module according to Embodiment 1 of the present invention from the side with a camera frame (camera housing) omitted, and FIG. 2 is a perspective view of the camera module according to Embodiment 1 of the present invention. It is a perspective view which shows an example from diagonally downward in the state which abbreviate | omitted the camera frame. As an example, a bifocal camera module that switches the focal length between the telephoto (tele) side and the wide-angle (wide) side will be described as an example. However, the present invention is not limited to the bifocal type, and the focal length is continuously set. The present invention can also be applied to a normal zoom lens that can be changed.

  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, reference numeral 17 denotes a third lens holder).

  As shown in the figure, a first lead screw 18 is disposed substantially parallel to the optical axis, and the first lead screw 18 is engaged with the first lens holder 15. When the lead screw 18 is driven to rotate, the first lens holder 15 moves along the optical axis. Similarly, the second lead screw 19 is disposed substantially parallel to the optical axis, and the second lead screw 19 is engaged with the second lens holder 16. When the lead screw 19 is driven to rotate, the second lens holder 16 moves along the optical axis (note that the second lead screw 19 is at a position that is substantially symmetrical with respect to the first lead screw 18. Is placed).

  A cylindrical (disc-shaped) first rotor 20 is attached to the lower end of the first lead screw 18 (the first rotor 20 is concentric with the first lead screw 18). The first rotor 20 is disposed at the end of the in-focus position of the first lead screw 18), and the first rotor 20 is in contact with the first piezo element 26 as will be described later. By the operation of the first piezo element 26, the first rotor 20 rotates, whereby the first lead screw 18 rotates, and the first lens holder 15 moves along the optical axis.

  A cylindrical (disc-shaped) second rotor 29 is attached to the lower end of the second lead screw 19 (the second rotor 29 is concentric with the second lead screw 19). The second rotor 29 is disposed at the end of the in-focus position of the second lead screw 19). The second rotor 29 abuts on the second piezo element 30 and the second piezo element 30. The operation of the element 30 causes the second rotor 29 to rotate, whereby the second lead screw 19 rotates, and the second lens holder 16 moves along the optical axis.

  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 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. 3A and 3B, the position of each lens group and the movement range for focusing are shown in FIG. For focusing, for example, in the case of the wide-angle (wide) side of FIG. 3A, the lens holder 15 of FIG. In the case of the (tele) side, the range indicated by the symbol B in FIG.

  That is, as shown in FIGS. 4A and 4B, 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. 4A: At this time, during AF, it moves within the scanning range defined by the 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 4 (b): At this time, during AF, it moves within a scan range defined by a wide angle).

  For example, as shown in FIG. 5, the first piezo element 26 described above is formed in a substantially rectangular shape, a first surface 261 formed in the longitudinal direction and the short direction, and a second side opposite thereto. An electrode (not shown) is provided on the surface 262, and a spacer (actuating portion) 26a that is engaged with an object to be moved relative to the third surface 263 in the short direction is provided, and the first surface 261 and the second surface By applying a sinusoidal voltage to the electrode provided at 262, a reciprocating motion is generated in the operating portion 26a, thereby realizing a relative movement with respect to the object with which the operating portion 26a is engaged. Thus, since the first piezo element 26 is a friction drive type, it is low speed but has high torque, excellent response and controllability, and can be positioned minutely. Holding torque (or holding force) when no power is supplied. , Excellent quietness, small size, and light weight (the second piezo element 30 is configured similarly to the first piezo element 26).

6 and FIG. 7, FIG. 6 is a perspective view showing the camera module 10 with the camera frame partially cut away, and FIG. 7 is a perspective view of FIG. 6 viewed from another angle. The substantially cubic camera frame 21 is formed of, for example, fluorine- containing polycarbonate. The camera frame 21 has a bearing portion (not shown) that supports the first lead screw 18 and the second lead screw 19 together. ) And a storage portion for storing the first lens holder 15 and the second lens holder 16 is formed.

The first lead screw 18 described above is rotatably supported by a bearing portion (not shown) between the upper surface and the lower surface of the camera frame 21, and the first lead screw 18 is provided with a coil spring 28. Thus, the first lead screw 18 is biased downward. Further, an optical sensor (light emitting element and light receiving element) 22 is attached to the side surface of the camera frame 21, and the optical sensor 22 controls the reference position of the optical lens system 12 and the amount of movement from the reference position as will be described later. Detected. A third lens holder 17 is attached to the upper surface of the camera frame 21.

  As shown in FIG. 6, on the side surface of the camera frame 21, a pair of flexible arm portions (connecting members) 23 extending in a direction orthogonal to the optical axis at a predetermined interval along the optical axis. And 24 are formed, and first piezo element support portions 25 are formed at the tips of these arm portions 23 and 24. That is, the camera frame 21 and the first piezo element support portion 25 are connected by the arm portions 23 and 24, and the first piezo element support portion 25 moves up and down along the optical axis by the arm portions 23 and 24. Is allowed to. The first piezo element support 25 is disposed substantially parallel to the first lead screw 18 and close to the first lead screw 18, as shown in the drawing. The first piezo element 26 is held by the first piezo element support portion 25, and the first piezo element 26 is guided in a direction in contact with the first rotor 20, and is further supported by the arm portions 23 and 24. The operating portion 26a of the first piezo element 26 is biased toward the rotor 20 side.

  6 and 7, it is hidden behind the camera frame 21, but similarly, the side surface of the camera frame 21 extends in a direction orthogonal to the optical axis at a predetermined interval along the optical axis. A pair of arms are formed, and a second piezo element support is formed at the tip of these arms. The second piezo element support portion is disposed substantially parallel to the second lead screw 19 and close to the second lead screw 19, and the second piezo element support portion is disposed in the second piezo element support portion. The second piezo element is guided by the second piezo element support portion in the direction in which the second piezo element abuts against the second rotor 29 (note that the second lead screw is also in the downward direction like the first lead screw). ).

  When attention is paid to the first piezo element 26, an operating portion 26 a is formed at the tip (lower end) of the first piezo element 26, and the first piezo element support 25 is urged downward by a coil spring 27. As a result, the operating portion 26a is pressed against the upper surface of the first rotor 20 (not shown, but similarly, the operating portion is formed at the tip (lower end) of the second piezo element). The second piezo element support portion is biased downward by the coil spring, so that the operating portion of the second piezo element is pressed against the upper surface of the second rotor).

  When the first piezo element 26 is excited, high-order bending vibration is generated in the operating portion 26a, and a traveling wave is generated. Then, a frictional force is generated between the first rotor 20 and the operating portion 26a to which the operating portion 26a is pressed, and the first rotor 20 is rotationally driven by this frictional force (for example, Japanese Patent No. 2980541 or (See Table 2002-529037).

  Referring to FIG. 8, FIG. 8 is a diagram for explaining the operation principle of the first piezo element 26. As described above, the first piezo element 26 is formed by the first piezo element support portion 25. The side surface is held, the first piezo element support portion 25 is urged downward, and the operating portion 26a of the first piezo element 26 is pressed against one surface of the first rotor 20 (FIG. 8A). And (b)). As a result, when the first piezo element 26 is excited, as shown in FIGS. 8C and 8D, the first piezo element 26 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 26a. Since the first piezo element 26 is bent in a direction intersecting the optical axis, it is desirable to hold the first piezo element 26 at two positions on the side surface.

  As shown in FIG. 7, a spiral cam body 18 a is formed on the outer peripheral surface of the first lead screw 18. Similarly, a spiral cam body 19 a is formed on the second lead screw 19. (The cam bodies 18a and 19a are not shown in FIGS. 1 and 2). As described above, when the first piezo element 26 and the second piezo element 30 are excited, the first rotor 20 and the second rotor 29 are rotationally driven. The rotation directions of the first rotor 20 and the second rotor 29 are changed by changing the direction of the voltage applied to the first piezo element 26 and the second piezo element 30.

  The first and second lead screws 18 and 19 are rotated by the rotation of the first rotor 20 and the second rotor 29, 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. The lens holders 15 and 16 (see FIG. 1) move along the optical axis. As shown in FIGS. 6 and 7, detection lines 20a extending in the axial direction are formed on the outer peripheral surface of the first rotor 20 at a predetermined interval, and the optical sensor 22 is connected to the first rotor 20 from the light emitting element. The outer peripheral surface of the first rotor 20 is irradiated with light, and the light reflected from the outer peripheral surface of the first rotor 20 is received by the light receiving element. Since the rotation angle can be detected by the number of repetitions for detecting the plurality of detection lines 20a, the control unit (not shown) rotates the first rotor 20 according to the number of repetitions of the received detection lines 20a, that is, The movement amount of the first lens holder 15 is grasped.

  Similarly, the amount of rotation of the second rotor 29 is detected by an optical sensor (not shown) provided corresponding to the second rotor 29, and the first and second lenses are detected as described above. The holders 15 and 16 are relatively driven along the optical axis, and the relative positions of the first and second lens holders 15 and 16 are changed to perform focusing and zooming.

  The above-described camera module is incorporated into a mobile terminal, for example. FIG. 9 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 mobile phone 50 shown in FIG. 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.

  First and second piezo elements are provided, the first and second piezo elements are brought into contact with the first and second rotors, respectively, and the first and second rotors are driven to rotate, respectively. Since the second lead screw is rotated and the first and second lens holders (lens holders) are driven along the optical axis, the number of parts can be increased even if the autofocus (AF) function and the zoom function are incorporated. As a result, the camera module can be reduced in size and weight, so that it can be applied to a camera module mounted on a portable terminal or the like.

It is a perspective view which shows roughly an example of the camera module by Example 1 of this invention from the side in the state which abbreviate | omitted the camera frame (camera housing | casing). It is a perspective view which shows an example of the camera module by Example 1 of this invention from diagonally downward in the state which abbreviate | omitted the camera frame. 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 an example of the camera module by Example 1 of this invention partially fractured | ruptured and shows a camera frame (camera housing | casing). It is a perspective view which shows the camera module shown in FIG. 5 from another angle. 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 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 holder 18, 19 Lead screw 20, 29 Rotor 21 Camera frame 22 Optical sensor 25 Piezo element support 26, 30 Piezo element 27 Coil spring

Claims (7)

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 move the first lens holding portion along the optical axis, and is arranged in parallel with the optical axis;
A second lens holding portion that engages with the second lens holding portion to move the second lens holding portion along the optical axis, and is disposed at a position that is symmetrical with the first lead screw with respect to the optical axis. Lead screw,
A first piezo element having a rectangular plate-like outer shape and having an operating portion at an end;
A second piezo element having a rectangular plate-like outer shape and having an operating portion at an end;
A first rotor that rotates integrally with the first lead screw and receives a driving force by contact with the first piezoelectric element;
A second rotor that rotates integrally with the second lead screw and receives a driving force by contact with the second piezoelectric element;
A first holding unit for holding the first piezo element at two positions on a side surface of the piezo element in parallel and close to the first lead screw to drive the first rotor;
Said second lead screw parallel and proximate to said second piezoelectric element for driving the second rotor and a second holding portion for holding at two positions in the side face of the piezoelectric element, wherein The first and second piezo elements are driven while detecting the rotation angles of the first and second rotors, and the relative positions of the first lens holding part and the second lens holding part in the optical axis direction are determined. A camera module characterized in that focus and zoom are performed by changing . The first rotor has a cylindrical shape concentric with the first lead screw and is disposed at an end of the first lead screw, and the second rotor is concentric with the second lead screw. The camera module according to claim 1, wherein the camera module has a cylindrical shape and is disposed at an end portion of the second lead screw.   The camera module according to claim 2, further comprising a guide portion that urges an operating portion of the first piezo element that drives the first rotor so as to abut against the first rotor. A bearing that pivotally supports both the first lead screw and the second lead screw;
A storage portion for storing the first lens holding portion and the second lens holding portion;
The camera module according to claim 3, further comprising a cubic case portion having a third lens holding portion that holds at least one optical lens.   The camera module according to claim 4, wherein the guide part and the biasing unit are arranged in the case part. An image pickup device, and a substrate holding the image pickup device provided on the lower surface of the case portion,
The camera module according to claim 4 or 5, wherein the third lens holding portion is disposed on an upper surface of the case portion. A first lens holding unit for holding at least one optical lens; a second lens holding unit for holding at least one optical lens; and a third lens for holding at least one optical lens. The holding portion, the cubic camera case portion, and the first lens holding portion are engaged to make the first lens holding portion movable along the optical axis, and are arranged in parallel with the optical axis. Engaging with the first lead screw and the second lens holding portion to move the second lens holding portion along the optical axis, and symmetrical with the first lead screw with respect to the optical axis the includes a second lead screw disposed at a position where the, the first piezoelectric element including an actuation portion on the end portion has a plate-like outer shape of a rectangle, the actuating portion at the end portion has a plate-like outer shape of a rectangular Two piezo elements and the first A first rotor which rotates integrally with the first screw and receives a driving force by contact with the first piezoelectric element; and a second rotor which rotates integrally with the second lead screw. A second rotor which receives a driving force by contact with the first rotor, and the first piezo element on a side surface of the piezo element in parallel with and close to the first lead screw for driving the first rotor . In order to drive the second rotor, the second holding element is held in two places on the side surface of the piezoelectric element in parallel with and close to the second lead screw in order to drive the second rotor. and a second holding portion for holding said first and said first and second piezoelectric element is driven while detecting the rotation angle of the second rotor, the first lens holding portion and the second The relative position of the optical axis of the lens holding portion by changing a camera module focus and zoom are performed,
An operation member, a display member, a battery, a communication unit,
Portable terminal comprising the camera module, wherein the display member, and a housing that is limited to the height of the camera module thickness while accommodating the battery and the communication unit.

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