JP3799056B2 - Camera module and portable terminal equipped with this camera module - Google Patents

Description

  The present invention relates to a camera module and a mobile terminal including the camera module, and more particularly to a camera module configured to be small and light and a mobile terminal including the camera module.

  Camera modules used in mobile terminals such as recent cellular phones are equipped with high-speed, high-precision autofocus (AF) functions similar to those of ordinary electronic cameras (digital cameras) as the image sensor (CCD) increases in pixel count. And a focal length change (zoom) function are required, and further downsizing and weight reduction of the mobile terminal itself inevitably requires the camera module to be reduced in size and weight.

  In order to perform autofocus and change in focal length (zoom) in such a camera module, it is necessary to move the lens group in the direction of the optical axis. As shown in the figure, one cylindrical cam arranged on the side surface of the optical system is driven by a motor to drive the zoom lens frame and the AF lens frame, and the cylindrical cam is also arranged adjacent to the lens frame. Is driven by a motor, thereby moving the lens frame for autofocus and the zoom lens frame to switch between two points of tele and macro.

  In addition to the cylindrical cam, the autofocus lens frame and zoom lens frame are configured to be driven by the corresponding autofocus lead screw and zoom lead screw, and the lens closest to the subject is fixed to the front of the case. The lead screw is provided at the corner of one side of the case, the lens frame guide support portion is provided in the case, the zoom lead screw is provided in the first quadrant around the optical axis, and the focus lead screw is provided in the second quadrant. There is a camera module configured such that the guide shaft of the lens frame is arranged in the third quadrant, a camera module having a mechanism for moving the lens group in the optical axis direction using a helicoid mechanism, and the like.

  However, in conventional camera modules using such cylindrical cams, lead screws, helicoids, etc., electromagnetic motors or pulse motors having a rotor are generally used as the drive source. The electromagnetic motor that uses the rotor requires an electromagnet or permanent magnet around it, and even if the axial length is shortened, the cylindrical part is indispensable. In addition, noise is also generated.

  Therefore, in order to solve the disadvantages of such an electromagnetic motor, a piezo element (PZT) that generates mechanical distortion in response to changes in electric and magnetic fields has been conventionally used as a drive source for moving the lens frame in the optical axis direction. A frictional drive type drive source is used in which a mechanical vibrator is constituted by a piezoelectric element such as a rotor, and a rotor or a slider is brought into contact with the mechanical vibrator so that the vibration of the mechanical vibrator can be extracted as an output. Such a friction drive type drive source is low speed but has high torque and excellent response and controllability, enables fine positioning, has a holding torque (or holding force) when not energized, has excellent quietness, It has advantages such as small size and light weight.

  For example, Patent Document 2 discloses an optical device in which a piezoelectric element is arranged on a lens frame and the lens is driven like a scale insect, and Patent Documents 3 and 4 describe a feed screw for driving a lens frame. A lens moving device in which a piezoelectric element is arranged in contact with an end portion to impart a stepwise rotation is shown, and Patent Document 5 is in contact with an electro-mechanical energy conversion element that vibrates when an electric signal is applied. Then, the lens frame is moved by a feed screw that is rotated by the vibration of the conversion element, or as shown in Patent Document 6, a linear drive vibration wave actuator (piezoelectric element) is used to contact the piezoelectric element. Have proposed that directly drive the lens frame.

  Furthermore, a piezoelectric element is arranged on either the lens frame or the lens barrel or the lens holder so that the lens is driven by the elliptical movement of the piezoelectric element, or a rotor is arranged at the end of the lead screw, and the outer periphery of the rotor is contacted. A configuration in which a piezoelectric element is arranged so as to be in contact, a rotor is rotated, and a lens is moved has been proposed. As a friction drive type drive source using such a piezo element (PZT) or the like, For example, it is shown in detail in Patent Document 7 to Patent Document 12.

However, in the friction drive type drive source using such a piezo element (PZT) or the like, the part where the piezo element contacts the driven body is scraped by friction, and the scraped dust stains the lens as dust, ghosts, flares, etc. May occur. As a method of dealing with such dust inside the optical system, for example, in Patent Documents 13 and 14, an adhesive is applied to the inside of the optical system to catch dust scattered by the rotation of the polygon mirror, It is shown that the opening is closed to adsorb dust. In Patent Documents 15 and 16, wear powder generated by friction using an electrostatic adsorbent material outside the optical axis region, or by using a resin material for the rotary polyhedral mirror bearing, is obtained by friction charging. A structure that is attached to a bearing portion is disclosed.
JP 7-63970 A Japanese Patent Laid-Open No. 5-107440 Japanese Patent Laid-Open No. 4-291213 JP-A-4-221910 JP-A-8-47273 JP-A-7-104166 JP 7-184382 A Japanese Patent No. 2980541 JP 9-37575 A JP 2000-40313 A Japanese translation of PCT publication No. 2002-522637 Japanese Patent Laid-Open No. 2003-501988 JP-A-6-148550 JP-A-7-77745 JP 9-294193 A JP-A-9-127451

  However, the techniques disclosed in Patent Documents 2 to 6 are mechanisms for driving a camera lens of a normal size, and camera modules used in mobile terminals such as mobile phones are always required to be downsized. It's too big to be applied to these mobile devices.

  The techniques disclosed in Patent Documents 13 to 15 also adsorb dust floating in the optical system and scattered foreign matter and do not deal with scraps scraped by friction. Although it is a wear powder, it is only adsorbed by frictional electrification, so if it stops rotating, it may float as dust and cannot be a fundamental solution.

  Therefore, in the present invention, a friction drive type driving source such as a piezo element is used to incorporate an autofocus (AF) function and a zoom function, and the piezo element and the driven member are brought into frictional contact with each other while being compact and lightweight. It is an object to provide a camera module and a portable terminal equipped with the camera module that can cope with the shavings that occur.

In order to solve the above problems, the camera module according to the present invention is:
A lens holding unit that holds at least one optical lens and includes a shaft hole;
A shaft member inserted into the shaft hole portion and disposed substantially parallel to the optical axis;
A piezoelectric element that includes an operating portion that contacts the shaft member at an end portion and is disposed in the vicinity of the shaft hole portion of the lens holding portion;
The shaft hole portion is formed by surrounding the shaft member with a dust collecting member on one side and a sliding portion with the shaft member on the opposite side of the shaft member with respect to the dust collecting member. It is characterized by that.

In order to solve the above problems, the portable terminal in the present invention is
A lens holding unit that holds at least one optical lens and includes a shaft hole;
A shaft member inserted into the shaft hole portion and disposed substantially parallel to the optical axis;
A piezoelectric element that includes an operating portion that contacts the shaft member at an end portion and is disposed in the vicinity of the shaft hole portion of the lens holding portion;
The shaft hole portion is formed to surround the shaft member, with a dust collecting member on one side and a sliding portion with the shaft member on the opposite side of the shaft member with respect to the dust collecting member. Camera module,
An operation member, a display member, a battery, a communication unit,
A housing that houses the camera module, the operation member, the display member, the battery, and the communication unit, and that regulates the thickness of the housing to a height of the camera module. It is characterized by.

  By configuring the camera module and the mobile terminal in this way, even if the operating portion of the piezo element abuts on the shaft member and scraps are generated, it is collected by the dust collecting member arranged in the vicinity of the shaft hole portion. It is possible to prevent the lens from becoming dirty and prevent ghosts and flares from occurring, and a camera module having an autofocus (AF) function and a zoom function can be configured to be small and lightweight. Further, the shaft hole portion is formed so that the dust collecting member is disposed on one side and the sliding portion is disposed on the opposite side of the shaft member with respect to the dust collecting member so as to surround the shaft member. Thus, the shaving residue can be collected by the dust collecting member without splashing from the shaft hole portion so as not to affect the others.

  Then, the dust collection member is disposed on a side of the shaft hole portion where the operation portion of the piezo element comes into contact with the shaft member, and the sliding portion includes an operation portion of the piezo element sandwiching the shaft member. It is an embodiment suitable for the present invention to have two locations on the opposite side and to dispose the dust collecting members on the contact position sides corresponding to the two sliding portions. By arranging the dust collecting member in the vicinity of the occurrence of the shavings, the dust can be collected before it is scattered.

  Further, by treating the surface of the shaft member in contact with the operating portion to be rougher than the non-contacting surface, driving by a piezo element can be performed more effectively, and the contact position of the operating portion Treating the friction coefficient of the shaft member and the sliding portion at a substantially opposite position to be lower than the friction coefficient between the operating portion and the shaft member, and lubricating the surface of the shaft member that slides with the sliding portion By applying the treatment and omitting the lubrication treatment on the surface of the shaft member that contacts the operating portion, the sliding portion can slide more smoothly.

  A first elastic member that urges the piezo element in the direction substantially perpendicular to the optical axis direction in the lens holding portion in a direction in which the operating portion comes into contact with the shaft member; A second elastic member biased in the direction is provided, and the first elastic member and the second elastic member are folded around an extension line of a cut provided on one side and fitted around the lens holding portion. The piece for urging the piezo element in the direction of the shaft member and the piece for extending the other side different from the one side in the direction of the piezo element holding portion and urging the piezo element in the optical axis direction are integrated. By using the elastic member provided on the piezoelectric element, it is possible to apply an urging force to the piezo element with an appropriate force with a simple configuration.

  According to the present invention, an autofocus (AF) function and a zoom function are incorporated by using a friction drive type driving source such as a piezo element, and the piezo element and a driven member are brought into friction contact with each other while being small and lightweight. It is possible to provide a camera module and a portable terminal equipped with the camera module that can cope with generated scraps and the like.

  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.

  1A is an external perspective view of the camera module of the embodiment as viewed from the lens direction on the subject side, FIG. 1B is an external perspective view of the camera module viewed from the image sensor side, and FIG. In the camera module of the embodiment viewed from the image sensor side, (A) is a perspective view with the image sensor module removed, (B) is a perspective view with the side cover further removed, and FIG. 3 is an exploded view showing the configuration of the image sensor module. 4A is a perspective view of the camera module according to the embodiment with the image sensor side lower cover removed, and FIG. 4B is a perspective view with the first lens holding frame holding the third lens group removed. , (C) is a perspective view in which the second lens holding frame for holding the second lens group is further removed, FIG. 5 is a perspective view showing an attachment state of electrical components such as an inductor, a sensor, and a capacitor, and FIG. First shaft member (motor shaft) FIG. 7 is an exploded view of the second lens holding frame that holds the second lens group, and FIG. 8 is the second lens group. FIG. 9A is a perspective view of the second lens holding frame holding the second lens holding frame, FIG. 9B is a perspective view of the second lens holding frame holding the second lens group, and FIG. The perspective view (A) which showed the relationship between a 1st shaft member (motor shaft) and a 2nd shaft member (guide shaft), and sectional drawing which showed the contact state of a piezoelectric element and a 1st shaft member (motor shaft) FIGS. 10A and 10B are plan views of another embodiment of the second lens holding frame that holds the second lens group, and FIG. 10B shows the contact between the piezo element and the first shaft member (motor shaft). FIG. 11 is a sectional view showing the dust collecting member and the adhesive member provided in the contact state and the first bearing portion, and FIG. 11 holds the third lens group. FIG. 12 is an exploded view of the first lens holding frame, FIG. 12 shows a lens and an image sensor that constitute an optical system in the camera module of the embodiment, (A) shows a state where the lens is on the wide angle side, and (B) FIG. 13 is a perspective view of the piezo element used in the camera module according to the embodiment, and FIGS. 13B and 13C are diagrams for explaining the operation principle. FIG. 14 shows an example in which two rollers having a flat surface with respect to the second shaft member (guide shaft) in the guide contact portion of the lens holding frame are arranged in a V shape, and FIG. (B) is a side view seen from the second shaft member (guide shaft) side, (C) is a perspective view, and FIG. 15 is a diagram schematically showing an example of a mobile phone in which the camera module of the embodiment is incorporated. It is. In the figure, the same number is attached | subjected to the same component.

  FIG. 1A is an external perspective view of the camera module 1 according to the embodiment, as viewed from the subject side lens direction, and FIG. 1B is an external perspective view of the camera module 1 viewed from the image sensor side. In the figure, 2 is a first lens group on the subject side, 20 is an image sensor module equipped with an image sensor such as a CCD, 21 is an ASIC that controls the entire camera module, and 22 is a first one that covers three of the side surfaces of the camera module 1. 1 is a side cover, 23 is a second side cover for shielding light, 201 is a digital signal processor (DSP) that processes an image captured by an image sensor such as a CCD, and the camera module of this embodiment is The whole is made in a size of about 10 × 10 × 20 mm.

  2A is a perspective view of the camera module 1 of the embodiment as viewed from the image sensor side of FIG. 1B, with FIG. 2A being a perspective view with the image sensor module 20 removed, and FIG. It is the perspective view which showed the camera module main body 24 which removed the side covers 22 and 23 and incorporated the imaging lens, the lens moving mechanism, and various electrical components. The imaging element module 20 shown in FIG. 2 (A) has a camera module main body 24 that is adjusted by incorporating an imaging lens, a lens moving mechanism, and various electrical components shown in FIG. The first and second side covers 22 and 23 are put on, and as shown in FIG.

  The camera module main body 24 in FIG. 2B has a lower cover 25 on the image sensor module 20 side, a first lens holding frame 26 that holds a third lens group described later, and a second lens group that holds a second lens group. A first shaft member for moving the first lens holding frame 26 and the second lens holding frame 27 itself up and down by the lens holding frame 27 and the piezoelectric elements incorporated in the first lens holding frame 26 and the second lens holding frame 27. (Motor shaft) 28, a second shaft member (guide shaft) 29 that guides while stopping rotation of the first lens holding frame 26 and the second lens holding frame 27, which is not visible in FIG. The upper cover 30 that holds one lens group, and the upright portion 31 that stands up from the upper cover 30 and that is equipped with electrical components and the like. Note that reference numeral 251 provided on the lower cover 25 is a restricting member for restricting the movement region of the first lens holding frame 26 and the second lens holding frame 27, and details will be described later.

  As shown in an exploded view in FIG. 3, the image sensor module 20 covers the image sensor 5 such as a CCD provided on the image sensor substrate 202 with an image sensor cover 204, and further, a filter for cutting infrared rays or the like thereon. 205 is covered.

  The above is the schematic configuration of the camera module 1 according to the present embodiment. The details of the camera module 1 will be described below. Before that, the optical system used in the camera module 1 of the present embodiment will be described with reference to FIGS. The structure of the piezoelectric element, the structure of the piezoelectric element, and the operation principle will be described.

  12A and 12B are diagrams showing a lens and an image sensor that constitute an optical system in the camera module 1 of the embodiment. FIG. 12A is a state where the lens is on the widest side, and FIG. It shows a state of being on the telephoto (tele) side. This optical system includes a first lens group 2 on the most object side, a second lens group 3 for changing a focal length disposed on the image sensor 5 side with respect to the first lens group 2, and an image sensor. The third lens group 4 is used for changing the focal length disposed on the side 5 and for focusing (focusing). Each lens group is composed of at least one or more optical lenses, and the second lens group 3 and the third lens group 4 as shown in FIG. Is moved to the wide-angle side when the lens is moved to the image pickup device 5 side using a CCD or the like, and the second lens group 3 and the third lens group 4 are moved to the first lens group 2 side as shown in FIG. When it approaches, it becomes the telephoto (tele) side, and the third lens group 4 moves back and forth at each position in the second lens group 3 to perform focusing.

  The camera module 1 of this embodiment uses a piezo element in which the movement of the second lens group 3 and the third lens group 4 is incorporated in lens holding frames 26 and 27 holding the lens groups 3 and 4. Since the second lens group 3 and the third lens group 4 can be driven independently, it is possible to focus while continuously changing the focal length, and as a normal zoom lens, It can also be configured as a bifocal lens. In the following description, a case where there are two lens holding frames will be described as an example, but it is obvious that a plurality of lens frames may be provided. The piezo element is incorporated in the lens holding frame that holds the second lens group 3 and the third lens group 4 as described above. Next, referring to FIG. 13, the piezo element used in this embodiment is used. The configuration and the operating principle of will be described.

  FIG. 13A is a perspective view of a piezo element used in the camera module 1 according to the embodiment, FIG. 13B is a configuration of the piezo element, and FIG. 13C is a diagram for explaining an operation principle. As described in detail in Patent Documents 7 to 12, the piezo element 10 has a longitudinal direction and a short length of the piezoelectric ceramic (piezo element) 11 formed in a substantially rectangular plate-like outer shape in FIG. As shown in FIG. 13B, four electrodes 121, 122, 123, and 124 are formed on the first surface 12 formed in the hand direction, and one electrode is formed on the entire surface of the second surface 13 on the opposite side. Is provided. The electrodes 121, 122, 123, and 124 on the first surface 12 are formed by the wires 125 and 126 that are arranged in the vicinity of the connecting portions of the respective electrodes 121, 122, and 123, 124 arranged in the diagonal direction. It is preferable that the electrodes are electrically connected and the second surface 13 is grounded.

  Further, a spacer 15 as a relatively hard ceramic operating portion is attached to the third surface 14 in the short direction, for example, by a bonding agent, preferably in the vicinity of the center of the side, for example, a shaft member that moves relatively. It engages with an object 16 as a contact portion such as a wall surface. Further, as shown in FIG. 13B, the piezoelectric ceramic (piezo element) 11 has a pair of supports 171 and 172 fixed around the vibration node and supports with elastic members such as springs. The body 173, 174, 175 is supported to be deformable.

  When a positive voltage is applied to the electrodes 121 and 124 and a negative voltage is applied to the electrodes 122 and 123 in the piezoelectric ceramic (piezo element) 11 configured as described above, the piezoelectric ceramic (piezo element) 11 becomes as shown in FIG. ), The left side of the figure is longer than the right side, and the vibration nodes are supported by the support bodies 173, 174, and 175 with springs, so that the spacer 15 is engaged. The object 16 moves to the right. When the voltage is no longer applied, the piezoelectric ceramic (piezo element) 11 returns to its original state. At this time, for example, when an asymmetric voltage pulse whose fall time is at least four times longer than the rise time is applied to the electrode, the piezoelectric ceramic ( Due to the friction between the spacer 15 and the object 16 in the piezo element 11, the spacer 15 returns to the starting position while the spacer 15 and the object 16 are engaged with each other at the fall of the pulse. The object 16 moves relatively. When the voltage is applied in the reverse direction, the piezoelectric ceramic (piezo element) 11 is deformed in the opposite direction, and thus the spacer 15 and the object 16 move in the opposite directions.

  In this way, the piezoelectric ceramic (piezo element) 11 continuously gives a signal voltage that causes the deformation shown in FIG. Because the relative position is displaced, low speed but high torque and excellent response and controllability, minute positioning is possible, and there is holding torque (or holding force) when no current is applied, and excellent quietness. It becomes a drive source having advantages such as small size and light weight.

  The above is the optical system configuration and the operation principle of the piezo element in the camera module 1 of the present embodiment. Next, the camera module 1 of the embodiment will be described in more detail with reference to FIGS. 4A is a perspective view in which the image sensor side lower cover 25 is removed in the camera module 1 of the embodiment, and FIG. 4B is an external view of the first lens holding frame 26 that holds the third lens group 4. FIG. 6C is a perspective view in which the second lens holding frame 27 that holds the second lens group 3 is further removed.

  As shown in FIGS. 4A, 4 </ b> B, and 4 </ b> C, the camera module body 24 holds the first lens holding frame 26 that holds the third lens group 4 and the second lens group 3. A second lens holding frame 27 is inserted into a first shaft member (motor shaft) 28 and a second shaft member (guide shaft) 29, and further a lower cover 25 is placed thereon.

  The lower cover 25 fixes the first shaft member (motor shaft) 28 and the second shaft member (guide shaft) 29 at predetermined positions, and the optical axis direction of the first lens holding frame 26 and the second lens holding frame 27. 4A to extend between the first lens holding portion 26 and the second lens holding portion 27 as shown in FIG. 4A, and the first bearing in the first lens holding frame 26. A regulated portion 261k (see FIGS. 4B and 11) provided in the portion 261a and a regulated portion 271k (see FIGS. 4 and 7) provided in the vicinity of the first bearing portion 271a in the second lens holding frame 27. A restricting member 251 having restricting portions 251a and 251b provided at a portion bent at a right angle is in contact with (see (A) and (D)). Therefore, as is apparent from FIG. 2B, the movement range of the first lens holding frame 26 is restricted by the lower cover 25 on the imaging element side and the restriction portion 251a of the restriction member 251 on the subject side. The movement range of the second lens holding frame 27 is restricted by the restricting portion 251b of the restricting member 251 on the imaging element side and the upper cover 30 on the subject side. Therefore, even when the drive source runs out of control when driving the first lens holding frame 26 and the second lens holding frame 27, the lens holding frames 26 and 27 do not move beyond a certain range, and the camera module 1 There is no such thing as being destroyed.

  FIG. 5 is a diagram for explaining the mounting state of the electrical components for operating the camera module 1, wherein 32 is a capacitor, 33 is an inductor, and these capacitor 32 and inductor 33 boost the drive voltage of the piezoelectric element. Used for. Reference numerals 341 and 342 denote position detection members for detecting positions in the optical axis direction, such as the first lens holding frame 26 and the second lens holding frame 27, and these electrical components are provided on the upper cover 30 in the camera module main body 24. The electrical component mounting holes 311 and the mounting holes 312, 313, 314, 315, and 316 provided in the upright portion 31 are attached.

  FIG. 6 is a view showing a state of attachment of the first shaft member (motor shaft) 28, the second shaft member (guide shaft) 29, and the subject side lens holder 36. The first shaft member (motor shaft) 28 and the second shaft member The biaxial member (guide shaft) 29 is press-fitted into shaft hole portions 301 and 302 provided in the upper cover 30, and the image sensor side is fixed by the lower cover 25 shown in FIG. In addition, a sensor tape for detecting the positions of the first lens holding frame 26 and the second lens holding frame 27 is fitted in the hole 317 in the upright portion 31 of the camera module main body 24 so that the first lens group 2 is integrated. The held first lens group holder 36 is mounted in a lens fixing hole 303 provided in the upper cover.

  FIGS. 7 to 11 show details of the first lens holding frame 26 and the second lens holding frame 27 in the camera module 1 described above. As will be described later, these first lens holding frame 26 and second lens holding frame 27. 27 is configured in substantially the same way.

  The second lens holding frame 27 for holding the second lens group 3 in the camera module 1 of the present embodiment holds the second lens group 3 integrally as shown in an exploded view in FIG. A second lens group holder 37 attached to the main body 271 of the lens holding frame, an urging spring member 272 for a piezo element fitted in the main body 271 of the second lens holding frame, a flexible substrate 273, and the second lens holding frame 27 And a position detecting member 274 for detecting the position of. 7A and 7B are perspective views of the second lens holding frame 27 viewed from different angles, and FIG. 7C is a perspective view of the second lens holding frame 27 with the position detection member 274 removed. FIG. 4D is an exploded perspective view in which the urging spring member 272 for the piezoelectric element and the flexible substrate 273 are further removed. FIG. 5E is an exploded perspective view in which the second lens group holder 37 is further removed.

  FIG. 9A shows the piezoelectric element 10, the first shaft member (motor shaft) 28, and the second shaft member (guide) except for the second lens holding frame main body 271 and the flexible substrate 273 from the second lens holding frame 27. (Shaft) 29, the second lens group holder 37, the sliding portion 271h provided on the second lens holding frame 27 and abutting on the first shaft member 28, and the piezoelectric element biasing spring member 272 are shown. 9B is a cross-sectional view showing a state where the operating portion 15 and the sliding portion 271h of the piezo element 10 are in contact with the first shaft member 28 in the same manner.

  As shown in FIGS. 7D and 9A, the piezo element urging spring member 272 makes the piezo element 10 held by the second lens holding frame main body 271 substantially orthogonal to the optical axis direction. A first elastic member 272a that urges the piezo element 10 in the direction of the optical axis, and a second elastic member 272b that urges the piezo element 10 in the optical axis direction. And the insulating member 272c using resin etc., and the insulating member for latching the insulating member 272c to the second elastic member 272b so that the second elastic member 272b and the piezo element 10 do not come into contact with each other The insulating member 262c is fixed to the second elastic member 262b by inserting the insulating member locking pin 262d through holes provided in the second elastic member 262b and the insulating member 262c. Squeezing stop Either, to create these second elastic members 262b and the insulating member 262c at outsert molding. The first elastic member 272a is bent on an extension line of the notch 272e provided on one side, is formed by a piece that urges the piezo element 10 toward the first shaft member 28, and the second elastic member 272b is The other side extends in the direction of the piezo element holding portion 271c, and is formed by a piece that urges the piezo element 10 in the optical axis direction. The first elastic member 272a and the second elastic member 272b are integrally formed. It is comprised with the formed elastic member.

  The piezoelectric element biasing spring member 272 is a first claw 271m (see FIGS. 7D and 8B) for fixing the piezoelectric element biasing spring member provided on the lens holding frame main body 271. ) Is engaged with the engaging portion 272f of the first elastic member 272a to the first claw, and the second claw 271n for fixing the piezo element urging spring member (see FIG. 7C). The engaging portion 272g of the piezo element urging spring member to the second pawl is locked and fixed to the second lens holding frame main body 271 in a fitting manner as shown in FIG. 7D. The In the embodiment shown in FIG. 7D and FIG. 9A, the piezoelectric element 10 is configured to be pressed from the top to the bottom by the piezoelectric element biasing spring member 272 in the drawing. Of course, this may be configured so that it can be pressed from the opposite direction, or can be pressed both vertically.

  7D, the end portion 273a of the flexible substrate 273 is fixed to the camera module main body 24, and the portion 273b expands and contracts with the top and bottom of the second lens holding frame 27. As shown in the sectional view of B), the operating portion 15 of the piezoelectric element 10 is bypassed by the U-shaped portion of 273c, bypassing the second elastic member 272b of the piezoelectric element biasing spring member 272. It is connected to a terminal (not shown) on the side to supply power. Since the flexible substrate 273 is obtained by covering the wiring member with an insulating film, the insulating member 272c needs to be used when passing between the piezoelectric element 10 and the second elastic member 272b. Therefore, the piezoelectric element position restricting portions 271f and 271g may be provided directly on the second elastic member 272b so that the insulating member 272c is not used. The flexible substrate 273 may be provided not only on the piezoelectric element biasing spring member 272 side but also on the opposite piezoelectric element fixing portion 271p side.

  8A is a plan view, FIG. 8B is a perspective view of the second lens holding frame 27 viewed from the piezoelectric element side with the flexible substrate 273 removed, and FIG. 9A is a first axis. FIG. 9B is a perspective view showing the relationship between the member 28 (motor shaft) and the second shaft member 29 (guide shaft). FIG. 9B shows the contact between the actuator 15 in the piezo element 10 and the first shaft member 28 (motor shaft). As shown in the sectional view of the contact state, the first shaft member 28 (motor shaft) is substantially symmetrical with respect to the optical axis of the first bearing portion 271a. The second shaft member 29 (guide shaft) is inserted through the second bearing portion 271b provided at the position, and the holder 37 of the second lens group 3 is inserted and fixed as shown in FIG. 7 (E). Then, the operating portion 1 in the piezo element 10 is attached to the first shaft member 28 (motor shaft). There is in contact, FIG. 13 is driven as described in raising and lowering the second lens holding frame 27. In addition, although the 1st bearing part 271a and the 2nd bearing part 271b were shown as a hole shape (1st bearing part 271a) and the open hole shape (2nd bearing part 271b) on the figure, it should not stick to this shape. Is self-explanatory.

  As shown in FIGS. 8B and 9B, the piezo element 10 itself is provided on the second lens holding frame 27 and is opened on the side opposite to the first shaft member 28 (motor shaft). The element 10 can be inserted, and the side surface parallel to the optical axis is guided by a fixed wall, and the upper and lower surfaces in the optical axis direction are as shown in FIG. 13C by the piezo element 10. The piezoelectric element position restricting portions 271d and 271e corresponding to the support members 171 and 172 shown in FIG. 13 are pressed so as to press the position of the vibration node provided in the piezoelectric element fixing portion 271p so as to be easily deformed. The piezoelectric element holding portion 271c provided with piezoelectric element position restricting portions 271f and 271g having the spring as the second elastic member 272b, which corresponds to the spring-supported body indicated by 173 and 174 in FIG. (Fig. 8 (B The first elastic member 272a is energized in the direction substantially perpendicular to the optical axis direction in the direction in which the operating portion 15 of the piezo element 10 contacts the first shaft member 28, and The second elastic member 272b is urged and held in the optical axis direction.

  The first shaft member (motor shaft) 28 side of the piezo element holding portion 271c is provided with the first bearing portion 271a as described above, and the first shaft member 28 is inserted therethrough and the first shaft The side of the member 28 opposite to the side where the operating portion 15 of the piezo element 10 is in contact is formed using a resin material or the like having low friction using fluorine-containing polycarbonate or PPS, and the shape is V-shaped. A sliding portion 271h having a first sliding portion 271ha that is a first V-shaped portion and a second sliding portion 271hb that is a second V-shaped portion is supported by a shaft 271hc. The first shaft member (motor shaft) 28 with which the operating portion 15 of the piezo element 10 abuts has a friction coefficient on the abutting side of the sliding portion 271h opposite to the side with which the operating portion 15 abuts. In addition to reducing the size, for example, the surface on the side on which the operating portion 15 abuts is rougher than the surface on which the sliding portion 271h abuts, the surface on the side on which the sliding portion 271h abuts is lubricated, etc. Thus, the operation of the piezo element 10 may be ensured and the sliding of the sliding portion 271h may be improved.

  The first sliding portion 271ha and the second sliding portion 271hb in the sliding portion 271h are arranged at a predetermined distance in the axial direction of the first shaft member 28 with respect to the operating portion 15 in the piezoelectric element 10 and are operated. The portion 15 is positioned approximately in the middle of the first sliding portion 271ha and the second sliding portion 271hb, and the operating portion 15 of the piezoelectric element 10 is positioned approximately in the middle of the thickness of the second lens holding frame 27. A piezo element holding portion 271c is formed.

  Therefore, the sliding portion 271h is biased in the direction in which the operating portion 15 of the piezoelectric element 10 contacts the first shaft member 28 by the first elastic member 272a of the above-described piezoelectric element biasing spring member 272. The first shaft member 28 is pressed and held by reaction, and the first shaft member (motor shaft) 28 and the sliding portion 271h, which is a V-shaped portion, are in line contact with each other. Combined with the low friction material, the second lens holding frame 27 can be smoothly moved up and down, and the piezo element holding portion 271c and the second lens holding frame 27 are provided with the first shaft member. The second lens holding frame 27 can be held more securely without causing any tilting, and the contact of the actuating portion 15 of the piezo element 10 with the first shaft member 28 can be more reliably performed without bending or biasing. Move up and down Can.

  Further, as shown in FIG. 8A, the second lens holding frame 27 is provided in parallel with the optical axis at a position that is substantially symmetrical with respect to the optical axis of the first bearing portion 271a. A second bearing portion 271b through which the biaxial member (guide shaft) 29 is inserted is provided using a resin material or the like having low friction using a fluorine-containing polycarbonate, PPS, or the like, and the second shaft member (guide shaft) 29 is provided. Thus, the second lens holding frame 27 is prevented from rotating, and the second lens holding frame 27 is prevented from being bent so that it can be smoothly moved up and down. As shown in FIG. 8A, the first bearing portion 272a and the second bearing portion 271b are configured such that the sliding portion 271h of the first bearing portion 272a has a substantially V-shape, and the second bearing portion 271b has a second shape. Although the shape corresponds to the outer shape of the shaft member (guide shaft) 29, for example, the sliding portion 272h of the first bearing portion 272a and the second bearing portion 271b may be configured using a substantially V-shaped roller. As shown in FIG. 14, the cylindrical flat rollers 40 and 41 are configured to be accommodated in the bearing portion 42 so as to be V-shaped with respect to the first shaft member 28 and the second shaft member 29. May be.

  FIG. 14A is a plan view of the bearing portion 42, and FIGS. 14B and 14C are a side view and a perspective view of the bearing portion 42, respectively. 40 and 41 are held in a V-shaped notch 43 provided in the bearing portion 42 so as to be V-shaped with respect to the shaft members 28 and 29 by a bearing 44 provided in a U-shape. Yes. By configuring the bearing portion 42 in this way, manufacturing errors occur in the first lens holding frame 26 and the second lens holding frame 27, and the second bearing portion is caused by thrust backlash in each of the orthogonal flat rollers 40 and 41. Even if the position of 271b deviates from the normal position, the flat rollers 40 and 41 are brought into contact with the V-shaped valleys formed when the flat rollers 40 and 41 are orthogonally crossed. This thrust backlash does not affect the optical axes of the first lens holding frame 26 and the second lens holding frame 27.

  Since the piezo element 10 is of a friction drive type as described above, scraping scraps are generated when the operating portion 15 comes into contact with the first shaft member (motor shaft) 28, and the scraping scraps form a lens as dust. Dirty and may cause ghosts and flares. In order to prevent this, FIG. 10 shows an example in which the scraps are collected or adhered and prevented from scattering. In the example shown in FIG. 10, the case of applying to the second lens holding frame 27 described above will be described. However, it is obvious that the first lens holding frame 26 can be configured in exactly the same manner.

  FIG. 10A is a plan view of the second lens holding frame 27 that holds the second lens group 3, and FIG. 10B is an abutment between the piezo element 10 and the first shaft member (motor shaft) 28. It is sectional drawing which showed the dust collection member 271r and adhesive member 271s which were provided in the state and the 1st bearing part 271a. In the figure, 271q is composed of a first sliding portion 271qa and a second sliding portion 271qb, and is a sliding portion that contacts the first shaft member (motor shaft) 28 inserted in the first bearing portion 271a. Unlike the first bearing portion 271a shown in FIGS. 8 and 9, the structure is such that the sliding portion 271h is not an independent part, but the sliding portion 271q constitutes a part of the first bearing portion 271a. The number of parts is being reduced. Reference numeral 271qc denotes a sliding base portion that connects the first sliding portion 271qa and the second sliding portion 271qb. Reference numeral 271r denotes that the operating portion 15 of the piezoelectric element 10 contacts the first shaft member (motor shaft) 28. A dust collecting member that collects the scraps generated in step 271, and 271 s indicated by a dotted line is an adhesive member.

  Of these, the dust collecting member 271r is, as is apparent from FIG. 10B, a piezo on the side where the operating portion 15 of the piezo element 10 in the first bearing portion 271a contacts the first shaft member (motor shaft) 28. The first sliding part 271qa and the second sliding part 271qb are provided on the opposite side where they are in contact with the first shaft member (motor shaft) 28, with a part of the element holding part 271c extending. The adhesive member 271s includes a sliding portion base portion 271qc that connects the first sliding portion 271qa and the second sliding portion 271qb, and a lens side of the piezo element holding portion 271c and respective side walls substantially opposed to the lens side. Is provided.

  Further, the sliding portion base portion 271qc in which the adhesive member 271s is disposed is provided so as to be at a position substantially corresponding to the position in the optical axis direction of the piezo element 10 disposed on the opposite side across the first shaft member 28. Thus, by arranging the dust collecting member 271r and the adhesive member 271s in the vicinity where the shavings are generated, the shavings are collected by the dust collecting member 271r on the piezo element 10 side, and the shavings that are not collected are provided on the side wall. The shaving residue on the first sliding portion 271qa and the second sliding portion 271qb side adheres to the member 271s and adheres to the adhesive member 271s provided on the sliding portion base portion 271qc, thereby effectively preventing scattering. .

  Further, it is important not only to collect the generated scraps but also to prevent the scraps from being generated, and the operating portion 15 of the piezo element 10 in the first shaft member (motor shaft) 28 is applied. As described above, the surface of the contact portion is processed to be rougher than the non-contact surface, or the portion where the first shaft member (motor shaft) 28 contacts the first sliding portion 271qa and the second sliding portion 271qb. The friction coefficient is processed to be lower than the side on which the operating unit 15 abuts, and the surface on which the first sliding portion 271qa and the second sliding portion 271qb of the first shaft member (motor shaft) 28 slide is lubricated. The operating portion 15 side of the piezo element 10 is omitted from the lubrication process so that the piezo element 10 can be driven more effectively, and the first sliding portion 271qa and the second sliding portion 271qb are provided. Smoother sliding When set to be as effective.

  FIG. 11 is an exploded perspective view of the first lens holding frame 26 that holds the third lens group. The first lens holding frame 26 holds the third lens group 4 integrally, and the first lens holding frame 26 The position of the third lens group holder 38 attached to the main body 261, the urging spring member 262 of the piezo element held by the main body 261 of the first lens holding frame 26, the flexible substrate 263, and the position of the first lens holding frame 26. The position detection member 264 and the like for detection are configured, and these structural members are substantially the same as the structural members of the second lens holding frame 27 shown in FIG.

  Among them, the piezo element urging spring member 262 is similar to the piezo element urging spring member 272 in the second lens holding frame 27, and the piezo element 10 held by the main body 261 of the first lens holding frame is in the optical axis direction. A first elastic member 262a that urges the piezo element 10 in the direction of the optical axis, and a first elastic member 262a that urges the piezo element 10 in the optical axis direction. The second elastic member 272b and the second elastic member 262b and the piezoelectric element 10 are in contact with each other so that they do not conduct and the insulating member 262c using resin or the like is engaged with the second elastic member 262b. The insulating member locking pin 262d is configured to be fixed, and the insulating member 262c is fixed to the second elastic member 262b by insulating the insulating member locking pin 262d from the second elastic member 262b. The second elastic member 262b and the insulating member 262c are formed by outsert molding by penetrating through a hole provided in the material 262c, and the piezo element is urged to the second lens holding frame material main body 261 The spring member 262 is fixed in the same manner as described in the second lens holding frame 27.

  The other components are also the same as those of the second lens holding frame 27, and the flexible substrate 263 has an end 263a fixed to the camera module main body 24 and the flexible substrate 263 of the second lens holding frame 27. Upside down, the portion of 263b is on the lower side, and can be expanded and contracted along with the upper and lower sides of the first lens holding frame 26. As shown in the sectional view of FIG. By bypassing the portion of the second elastic member 262b in the piezo element biasing spring member 262, the piezo element urging spring member 262 is connected to a terminal (not shown) on the operating portion 15 side of the piezo element 10 to supply power.

  Further, the main body 261 of the first lens holding frame is provided with a first bearing portion 261a and a second bearing portion 261b, and the first shaft member 28 (motor shaft) and the second shaft member 29 (guide shaft) are inserted therethrough. The holder 38 of the third lens group 4 is inserted and fixed. Then, the operating portion 15 of the piezo element 10 is brought into contact with the first shaft member 28 (motor shaft), and the second lens holding frame 27 is moved up and down by driving as described in FIG. The configuration of the piezo element holding portion 261c, the first bearing portion 261a, the second bearing portion 261b, etc. is exactly the same as that of the second lens holding frame 27 described above.

  In the camera module 1 of the embodiment configured as described above, a driving current composed of a driving signal is applied to each of the piezo elements 10 provided in the first lens holding frame 26 and the second lens holding frame 27 by a control circuit (not shown). By applying, the spacer 15 vibrates and the reciprocating motion is excited as described above, and the first lens holding frame 26 and the second lens holding frame 27 holding the piezo element 10 move upward or downward, It is possible to change the focal length including zooming and focus (focus).

  Thus, the camera module 1 is configured by inserting the first lens holding frame 26 and the second lens holding frame 27 through the common first shaft member (motor shaft) 28 and second shaft portion (guide shaft) 29. The camera module 1 can be configured to be small and light, and the autofocus (AF) and the focal length can be changed only by applying a signal current to the piezo element 10, and the piezo element 10 is configured as described above. Although it is low speed, it has high torque, excellent response and controllability, fine positioning is possible, and it is compact and lightweight, so it is compact and lightweight, and it can perform focal length change and focusing in a short time. Can be provided.

  FIG. 15 is an example of a portable terminal incorporating the camera module 1 described above. The mobile terminal shown in FIG. 17 shows a case of a mobile phone 50 as an example. In the figure, 51 is an operation unit (operation member), 52 is a display (display member), and FIG. 17 is a plan view showing the operation unit (operation member) 51 and the display (display member) 52 visible (open state). In the illustrated mobile phone 50, a first case portion 53 on which an operation portion 51 is mounted and a second case portion 54 on which a display 52 is mounted are connected by a hinge mechanism 55, and the first and first case portions are connected. The two case portions 53 and 54 are rotatable around the hinge mechanism 55. 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 1 as shown by a broken double circle in the figure, and when a predetermined button of the operation unit 51 is operated, the camera module 1 takes an image, The captured image is displayed on the display 52, for example. The camera module 1 has the upper side shown in FIG. 1A facing the outside of the second case portion 54. That is, the second case portion 54 is formed with an opening for exposing the first lens group 2 in the camera module 1, and although not shown, the first case portion 53 has a battery, a communication portion, and the like. Further, the thickness dimension of the second case portion 54 is substantially regulated to the height of the camera module 1.

  As described above, according to the present embodiment, it is possible to provide a small and lightweight camera module incorporating an autofocus (AF) function and a zoom function, and a portable terminal equipped with the camera module. .

  Built-in auto focus (AF) function and zoom function using a friction drive type drive source such as a piezo element, making it compact and lightweight, and for scraps generated by frictional contact between the piezo element and the driven member It is possible to cope with it, and it is optimal as a camera module in various small portable terminals.

4A is an external perspective view of the camera module of the embodiment as viewed from the subject side lens direction, and FIG. 5B is an external perspective view of the camera module as viewed from the image sensor side. FIG. 2B is a perspective view of the camera module according to the embodiment as viewed from the image sensor side in FIG. 1, in which FIG. 1A is a perspective view with the image sensor module removed, and FIG. It is an exploded view which shows the structure of an image pick-up element module. In the camera module of the embodiment, (A) is a perspective view with the image sensor side lower cover removed, (B) is a perspective view with the first lens holding frame holding the third lens group removed, and (C). Furthermore, it is the perspective view which removed the 2nd lens holding frame which hold | maintains a 2nd lens group. It is the perspective view which showed the attachment state of electrical components, such as an inductor, a sensor, and a capacitor | condenser. It is the perspective view which showed the attachment state of the 1st shaft member (motor shaft), the 2nd shaft member (guide shaft), and a to-be-photographed object side lens. It is an exploded view of the 2nd lens holding frame holding a 2nd lens group. FIG. 5A is a plan view of a second lens holding frame that holds a second lens group, and FIG. 7B is a perspective view of the second lens holding frame as viewed from the piezoelectric element side with the flexible substrate removed. The perspective view (A) which showed the relationship between the 1st shaft member (motor shaft) and the 2nd shaft member (guide shaft) of the 2nd lens holding frame which hold | maintains a 2nd lens group, a piezo element, and a 1st shaft member It is sectional drawing (B) which showed the contact state of (motor shaft). (A) is a top view in the other Example of the 2nd lens holding frame which hold | maintains a 2nd lens group, (B) is the contact state of a piezoelectric element and a 1st shaft member (motor shaft), and 1st. It is sectional drawing which showed the dust collection member and adhesive member which were provided in the bearing part. It is an exploded view of the 1st lens holding frame holding a 3rd lens group. The lens and imaging device which comprise the optical system in the camera module of embodiment are shown, (A) shows the state which has a lens in a wide angle (wide) side, (B) has shown the state which has a telephoto (tele) side It is. (A) of the piezo element used for the camera module which becomes embodiment is a perspective view, (B), (C) is a figure for demonstrating an operation principle. An example in which two rollers having a flat surface with respect to the second shaft member (guide shaft) in the guide contact portion of the lens holding frame are arranged in a V shape, (A) is a sectional view, (B ) Is a side view seen from the second shaft member (guide shaft) side, and (C) is a perspective view. It is a figure which shows roughly an example of the mobile telephone with which the camera module of embodiment was incorporated.

Explanation of symbols

1: Camera module 2: First lens group 3: Second lens group 4: Third lens group 5: Image sensor 10: Piezo element 15: Spacer 27: Second lens holding for holding the second lens group Frame 271: Second lens holding frame body 271a: First bearing portion 271b: Second bearing portion 271c: Piezo element holding portion 271d, 271e, 271f, 271g: Piezo element position restricting portion 271p: Piezo element fixing portion 271q: Sliding Part 271qa: First sliding part 271qb: Second sliding part 271qc: Sliding part base 271r: Dust collecting member 271s: Adhesive member 272: Piezo element biasing spring member 272a: First elastic member 272b: Second Elastic member 272c: insulating member 272d: insulating member locking pin

Claims (9)

A lens holding unit that holds at least one optical lens and includes a shaft hole;
A shaft member inserted into the shaft hole portion and disposed substantially parallel to the optical axis;
A piezoelectric element that includes an operating portion that contacts the shaft member at an end portion and is disposed in the vicinity of the shaft hole portion of the lens holding portion;
The shaft hole portion is formed to surround the shaft member, with a dust collecting member on one side and a sliding portion with the shaft member on the opposite side of the shaft member with respect to the dust collecting member. A camera module characterized by that.   2. The camera module according to claim 1, wherein the dust collecting member is disposed on a side of the shaft hole where the operating portion of the piezo element comes into contact with the shaft member.   The sliding portion has two locations on the side facing the operating portion of the piezo element across the shaft member, and the dust collecting members are respectively provided on the contact position side corresponding to the two sliding portions. The camera module according to claim 2, wherein the camera module is arranged.   4. The camera module according to claim 1, wherein a surface of the shaft member that is in contact with the operating portion is rougher than a non-contact surface. 5.   The friction coefficient of the said shaft member and the said sliding part in the position substantially opposite to the said contact position of the said action | operation part was processed lower than the friction coefficient of the said action | operation part and the said shaft member. Camera module.   6. The surface of the shaft member that slides with the sliding portion is lubricated, and the surface of the shaft member that contacts the operating portion is omitted from the lubrication treatment. The camera module.   A first elastic member that urges the piezo element in a direction substantially perpendicular to the optical axis direction in the lens holding portion and a direction in which the operating portion abuts the shaft member; and an optical axis direction The camera module according to claim 1, further comprising a second elastic member to be urged.   The first elastic member and the second elastic member are pieces that are fitted around the lens holding portion and bent along an extension line of a notch provided on one side, and bias the piezoelectric element toward the shaft member. And another side that is different from the one side extends in the direction of the piezoelectric element holding portion, and is formed of an elastic member integrally provided with a piece that urges the piezoelectric element in the optical axis direction. The camera module according to claim 7. A lens holding unit that holds at least one optical lens and includes a shaft hole;
A shaft member inserted into the shaft hole portion and disposed substantially parallel to the optical axis;
A piezoelectric element that includes an operating portion that contacts the shaft member at an end portion and is disposed in the vicinity of the shaft hole portion of the lens holding portion;
The shaft hole portion is formed to surround the shaft member, with a dust collecting member on one side and a sliding portion with the shaft member on the opposite side of the shaft member with respect to the dust collecting member. Camera module,
An operation member, a display member, a battery, a communication unit,
A housing that houses the camera module, the operation member, the display member, the battery, and the communication unit, and that regulates the thickness of the housing to a height of the camera module. A mobile terminal characterized by.

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