JP2014232190A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device in which a larger diameter of a lens can be achieved without enlarging the entire imaging device.SOLUTION: An imaging device includes: a lens barrel 9 that holds a lens 12; and a barrel holder 5. The barrel holder 5 includes: a female screw portion 51 of a triple-thread screw; and an abutting stop portion 52 that abuts and stops the lens barrel 9. The lens barrel 9 includes a male screw portion 91 of a triple-thread screw that is screwed to the female screw portion 51. The male screw portion 91 of a triple-thread screw includes at one end a multiple-thread screw contact portion 91b that is in contact with the abutting stop portion 52, and the multiple-thread screw contact portion 91b is formed so that one end of the male screw portion 91 of a triple-thread screw is substantially perpendicular to an optical axis direction.

Description

  The present invention relates to an imaging apparatus that can be mounted on a mobile phone or the like.

  2. Description of the Related Art Conventionally, a small imaging device (camera module) that can be mounted on a mobile phone, a personal computer, an in-vehicle device, a security application, or the like is known. In recent years, with the spread of smartphones and tablet terminals, there is an increasing demand for advanced camera functions. For this reason, for example, the size of the camera is reduced, the height is lowered, the aperture is increased due to the lower F-number of the lens for higher image quality, and the tilt (tilt) of the lens is reduced when the imaging sensor is narrowed (higher pixels). The demand for higher size and higher image quality is increasing. Furthermore, there is an increasing demand for reduction in tact time for mass production and cost reduction.

  In such a camera module, for example, in Patent Document 1, a lens barrel (lens housing member) that holds a lens and has a male screw portion formed on the outer periphery, and a female screw that is screwed into the male screw portion on the inner periphery. There is disclosed a camera module including a formed barrel holder and a ring-shaped lens fixing washer having elasticity as a lens housing member fixing means disposed on one end side of the barrel holder. And in this patent document 1, while a lens barrel is screwed together with a barrel holder and the one end surface of the lens barrel in the axial direction is abutted against the lens fixing washer, the lens barrel is fixed by the elastic force of the lens fixing washer. Secure the barrel holder.

JP 2011-77927 A

  However, in Patent Document 1, a lens fixing washer is disposed on one end surface side in the axial direction of the lens barrel holding the lens. For this reason, for example, if the lens barrel is made thin in the radial direction and a large-diameter lens is held on the inner peripheral side, there is a high possibility that the lens fixing washer becomes a restriction on the optical path. As a result, there is a problem that it is difficult to increase the diameter of the lens without increasing the size of the entire imaging apparatus.

  An object of the present invention is to provide an imaging apparatus capable of increasing the diameter of a lens without increasing the size of the entire imaging apparatus.

  An imaging apparatus according to the present invention includes a lens barrel that holds one or more lenses, and a cylindrical barrel holder that holds the lens barrel, and the barrel holder is a multi-thread screw formed on the inner periphery thereof. A plurality of female threads, and an abutment portion formed on one end side in the axial direction of the barrel holder for retaining the lens barrel, wherein the lens barrel is formed on an outer periphery thereof and is threaded into the female screw. A male screw portion of the screw, and a stopper portion that contacts and stops against the stopper portion, and the stopper portion has a vertical surface in which one end of the male screw portion is substantially perpendicular to the optical axis direction. The multi-thread screw contact portion formed at one end of the male screw portion is provided.

  According to this configuration, it is possible to increase the aperture diameter of the stopper, and to increase the lens diameter (designing a lens with a low F number) without increasing the size of the entire imaging apparatus, or to reduce the size of the entire imaging apparatus. Can be achieved.

  In this case, the multi-threaded screw contact portion is formed so that one end of the male thread portion of the multi-threaded screw is a vertical surface substantially perpendicular to the optical axis direction. Accordingly, the lens barrel is held by the barrel holder so that the position and posture in the optical axis direction with respect to the imaging sensor can be determined, and the image quality of the imaging apparatus can be improved.

  Further, since the barrel holder and the lens barrel are screwed together by the male screw portion and the female screw of the multi-threaded screw, the screwing torque can be reduced and the rotation amount can be reduced, thereby improving the productivity.

  In another aspect, the female screw portion and the male screw portion are three or more multi-thread screws.

  According to this configuration, the multi-thread screw contact portions are formed at equal intervals in at least three locations in the circumferential direction, whereby the lens barrel can more accurately and accurately determine the position and posture in the optical axis direction with respect to the image sensor. It is held by the barrel holder in the state, and the image quality of the imaging device can be further improved.

  In another aspect, the female screw portion and the male screw portion are square screws or trapezoidal screws.

  According to this configuration, the area of the multi-thread screw abutting portion is larger than that of, for example, a triangular screw, whereby the lens barrel is more stably positioned and held by the barrel holder.

  In another aspect, the apparatus further includes a drive member that moves the barrel holder in the optical axis direction.

  According to this configuration, when a lens of a certain size is used, a barrel holder with a small outer diameter is used, so that a space for arranging the driving device can be increased, and driving force and straightness can be ensured. Can contribute.

  The imaging device of the present invention can increase the diameter of the lens without increasing the size of the entire imaging device.

1 is an exploded perspective view of an imaging apparatus according to an embodiment of the present invention. It is sectional drawing of the imaging device of FIG. It is a disassembled perspective view of the apparatus main body used for the imaging device of FIG. It is a perspective view of the actuator used for the imaging device of FIG. It is a perspective view of the actuator holder used for the imaging device of FIG. It is a principal part expanded sectional view of the connection part of the electrode terminal and piezoelectric element which are used for the imaging device of FIG. (A) is a perspective view from the right rear side of the elastic member used for the imaging device of FIG. 1, (b) is a perspective view from the left front side of the elastic member of FIG. 7 (a), (c) is. FIG. 8 is a plan view of the elastic member of FIG. It is a perspective view of the barrel holder used for the imaging device of FIG. (A) is a perspective view of the lens holder used for the imaging device of FIG. 1, (b) is a top view of FIG. 9 (a). FIG. 9A is a side view in which the male screw portion of the lens holder in FIG. 9A is in an unfolded state, and FIG. 9B is a bottom view in which the lens holder in FIG. It is sectional drawing of the state in which the lens holder was hold | maintained at the barrel holder. (A) is a cross-sectional view of a lens holder and a barrel holder of another embodiment, (b) is a side view in which the male screw portion of the lens holder of FIG. FIG. 13 is a bottom view of the lens holder in FIG. (A) is a sectional view of a lens holder and a barrel holder of still another embodiment, (b) is a side view of the lens holder of FIG. 13 (a) in a developed state, and (c) is a side view. FIG. 14 is a bottom view of the lens holder of FIG. FIG. 14A is a plan view of a lens holder and a barrel holder according to still another embodiment, FIG. 14B is a cross-sectional view taken along the line XIV-XIV in FIG. 14A, and FIG. FIG. 15A is a side view of the lens holder of FIG. 14A in a developed state, and FIG. 14D is a bottom view of the lens holder in FIG. FIG. 16A is a cross-sectional view of a comparative example, and FIG. 15B is a cross-sectional view of a state in which a lens holder is fastened to a barrel holder from the state of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of an imaging apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the imaging apparatus of FIG. In the following description, the X direction in FIGS. 1 to 4 and 6 to 15 will be described as the upper side (object side), and the Y direction will be described as the lower side (image side).

  The imaging device 1 of the present invention is used by being mounted on, for example, a mobile phone. As shown in FIGS. 1 and 2, the imaging apparatus 1 of this embodiment includes an apparatus main body 1 a and a lens barrel 9 held by the apparatus main body 1 a.

  As shown in FIG. 3, the apparatus main body 1a includes an actuator holder 2, an actuator (driving member) 3 held by the actuator holder 2, a barrel holder 5 held by the actuator 3 via an elastic member 6, and a cover. 8 and.

  As shown in FIG. 5, the actuator holder 2 is made of a resin material such as LCP (liquid crystal polymer), and is formed by injection molding with a part of electrode terminals 22 and 23 described later inserted. The actuator holder 2 of this embodiment is a cylindrical body having a rectangular outer periphery and a circular through hole 20g serving as an optical path at the center.

  The actuator holder 2 includes a first support column 20a at the first corner 2a on the left front side. The actuator holder 2 includes an actuator fixing portion 21 that holds the actuator 3 inside the first support column 20a in the first corner portion 2a.

  The actuator fixing portion 21 is formed so as to be recessed in a cylindrical shape with a predetermined depth from the upper surface 2 e of the actuator holder 2, and the upper side is opened.

  Further, the actuator holder 2 has the tip 22a of the first electrode terminal 22 and the tip 23a of the second electrode terminal 23 on the upper side of the actuator holder 2 on both sides of the actuator fixing portion 21 in the first corner 2a. It is arrange | positioned so that it may protrude.

  As shown in FIG. 6, the first electrode terminal 22 and the second electrode terminal 23 have an intermediate portion embedded in the actuator holder 2 and a proximal end projecting from the outer surface of the actuator holder 2. External connection terminals 22b and 23b are formed. And the circuit board and connector of the mobile phone which are not shown in which this imaging device 1 is mounted, and these external connection terminals 22b and 23b are connected.

  Further, in this embodiment, as shown in FIG. 6, the external connection terminals 22b of the first electrode terminals 22 and the external connection terminals 23b of the second electrode terminals 23 are respectively arranged such that the lower surfaces of the external connection terminals 22b and 22b are the same. It is bent through a step so as to be flush with each other. Thereby, each of the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b of the second electrode terminal 23 can be connected to the circuit board so as to be energized by being placed on the circuit board of the mobile phone, for example. ing.

  Further, as shown in FIG. 3, the actuator holder 2 has a second support column 20b, a third support column 20c, a second support column 20c, a second corner 2c, a third corner 2c, and a fourth corner 2d, respectively. 4 support pillars 20d are provided.

  Further, as shown in FIG. 2, the actuator holder 2 has an image sensor mounting reference surface 19a on the lower surface when the image sensor is mounted. In this embodiment, substantially the entire lower surface of the actuator holder 2 forms an image sensor attachment reference surface 19a, and a sensor substrate 7 having an image sensor 72 described later is attached to the image sensor attachment reference surface 19a. The optical surface of the element 72 is arranged in parallel with the imaging element attachment reference surface 19a.

  As shown in FIG. 4, the actuator 3 includes a piezoelectric element 31 that is an electromechanical conversion element that expands and contracts in the axial direction, a drive shaft 32 that is joined to one end of the piezoelectric element 31, and a joint that is joined to the other end of the piezoelectric element 31. A weight 33 is provided.

  The weight 33 is for generating a larger displacement on the drive shaft 32 side due to the expansion and contraction of the piezoelectric element 31. In this embodiment, the weight 33 is made of a material having a high specific gravity such as tungsten or a tungsten alloy.

  Further, the weight 33 is formed of a columnar shape whose outer diameter protrudes from the outer periphery of the piezoelectric element 31 over the entire periphery in the outer peripheral direction.

  The weight 33 may be omitted when the other end of the piezoelectric element 31 is attached to the actuator holder 2 and can exhibit the same function as the function of the weight 33.

  The piezoelectric element 31 is an element that converts input electric energy into mechanical energy that expands and contracts, that is, mechanical motion. For example, a piezoelectric element that converts input electric energy into mechanical elastic motion by a piezoelectric effect, or the like It is. Such a piezoelectric element includes, for example, a laminated body and a pair of external electrodes.

  The laminated body is formed by alternately laminating a plurality of thin film (layered) piezoelectric layers made of a piezoelectric material and a conductive thin film (layered) internal electrode layer. In the present embodiment, the laminate has a quadrangular prism shape, but is not limited to this, and may be, for example, a polygonal column shape or a cylindrical shape.

  Each of the plurality of internal electrode layers is configured to face the outside with a pair of outer peripheral side surfaces facing each other. The pair of external electrodes are formed along the stacking direction on the pair of outer peripheral side surfaces in the stacked body, and supply the electric energy to the stacked body, and are sequentially and alternately connected to the plurality of internal electrodes. .

Examples of the piezoelectric material include so-called PZT, lithium niobate (LiNbO ₃ ), potassium niobate tantalate (K (Ta, Nb) O ₃ ), barium titanate (BaTiO ₃ ), lithium tantalate (LiTaO ₃ ), and titanium. An inorganic piezoelectric material such as strontium acid (SrTiO ₃ ).

  The piezoelectric element 31 is formed by sputtering silver or the like on the two side surfaces facing the external electrodes 31a that connect the electrodes between the layers in parallel.

  The lower end surface of the piezoelectric element 31 is bonded to the upper end surface of the weight 33 with a bonding adhesive such as an epoxy adhesive. In this embodiment, a bonding adhesive is used in which resinous beads are mixed in an epoxy adhesive in order to prevent a short circuit with the weight and stabilize the thickness of the adhesive layer.

  The drive shaft 32 is made of CFRP molded in a cylindrical shape with resin so that carbon fibers are arranged in the axial direction. The drive shaft 32 of this embodiment is formed so that the outer diameter protrudes from the outer periphery of the piezoelectric element 31 to the outer periphery over the entire periphery.

  The lower end surface of the drive shaft 32 is bonded to the upper end surface of the piezoelectric element 31 with a bonding adhesive. This bonding adhesive is the same as the bonding adhesive obtained by bonding the piezoelectric element 31 and the weight 33.

  Also, the bonding adhesive (fillet) that protrudes from the bonding surface between the drive shaft 32 and the piezoelectric element 31 is formed on the piezoelectric element side, so that the entire area of the drive shaft 32 can be transferred to the barrel holder. 5, and a large stroke can be realized with a short drive shaft 32.

  As shown in FIG. 2, the actuator 3 configured as described above is arranged so that the weight 33 side (one end side) is downward and is fitted and inserted into the actuator fixing portion 21 of the actuator holder 2 from above. The actuator fixing portion 21 and the weight 33 are bonded and fixed by a fixing adhesive.

  In addition, the actuator 3 held in the actuator fixing portion 21 of the actuator holder 2 in this way is connected to the external electrode 31a of the piezoelectric element 31 via the first electrode connecting spring 24a and the second electrode connecting spring 24b, and the second electrode connecting spring 24b. Each of the tip 22a of the first electrode terminal 22 and the tip 23a of the second electrode terminal 23 is connected so as to be energized.

  Specifically, as shown in FIG. 6, the first electrode connection spring 24a and the second electrode connection spring 24b have the same configuration, and each of them is plated with gold or platinum, and the coil portion 25a. And a torsion coil spring provided with a first foot portion 25b and a second foot portion 25c projecting radially outward from the coil portion 25a.

  The first electrode connecting spring 24a is configured such that the tip 22a of the first electrode terminal 22 is pushed into the coil portion 25a, the first foot portion 25b is in contact with one external electrode 31a of the piezoelectric element 31, and the second The foot portion 25 c is locked to a spring locking portion 26 (shown in FIG. 9) provided on the actuator holder 2. In this state, a torsional force is accumulated in the coil portion 25a, and the first foot 25b presses the external electrode 31a of the piezoelectric element 31 by the torsional force.

  The second electrode connection spring 24b is such that the tip 23a of the second electrode terminal 23 is pushed into the coil portion 25a, the first foot portion 25b contacts the other external electrode 31a of the piezoelectric element 31, and the second The foot portion 25c is locked to the spring locking portion 26 (see FIG. 9) of the actuator holder 2. In this state, a torsional force is accumulated in the coil portion 25a, and the first leg 25b presses the external electrode 31a of the piezoelectric element 31 by the torsional force.

  In this embodiment, the conductive adhesive is applied from the contact portion between the first foot portion 25b of each of the first electrode connecting spring 24a and the second electrode connecting spring 24b and the external electrode 31a of the piezoelectric element 31 to the coil portion 25a. 27 is interposed. Thereby, in addition to the 1st electrode connection spring 24a and the 2nd electrode connection spring 24b, the conductive adhesive 27 can energize the external electrode 31a of the piezoelectric element 31, and the 1st electrode terminal 22 and the 2nd electrode terminal 23. Connected to ensure a secure connection between the two.

  In this embodiment, the surface of the conductive adhesive 27 is covered with the reinforcing adhesive 28 so that the adhesive strength of the conductive adhesive 27 is reinforced.

  Next, the barrel holder 5 will be described. In this embodiment, the barrel holder 5 is made of a synthetic resin such as liquid crystal polymer (LCP), and is formed in a cylindrical shape by injection molding as shown in FIG.

  The barrel holder 5 includes a female thread portion 51 of a multi-threaded screw formed on the inner periphery, and a stopper 52 formed at the lower end (one end) in the axial direction on the inner periphery.

  The female thread portion 51 is for connecting the lens barrel 9, and in this embodiment, similar to the male thread portion 91 of the lens barrel 9 to be described later, the female thread portion 51 is composed of a three-thread screw whose lead is three times the pitch. Has been. The female screw portion 51 is formed of a triangular screw having a triangular thread cross section (see FIG. 11).

  The stopper 52 is for stopping the lens barrel 9 and is formed on the inner periphery of the lower end of the barrel holder 5 over the entire circumference as shown in FIG. The inner diameter of the stopper 52 is set to be smaller than the outer diameter of the male thread 91 of the lens barrel 9 described later. In this embodiment, the stopper 52 is formed so that its inner diameter is slightly smaller than the diameter of the valley of the male screw portion 91.

  As shown in FIGS. 3 and 7, the elastic member 6 is formed by forming a leaf spring into a substantially ring shape. The elastic member 6 includes an elastic ring-shaped holding part 63 that holds the outer periphery of the barrel holder 5, a first clamping part 61 disposed at one end of the holding part 63, and the holding part 63. And a second clamping unit 62 disposed at the other end.

  The 1st clamping part 61 is formed so that it may protrude on the diameter outer side. On the other hand, the 2nd clamping part 62 is formed so that it may protrude inside a diameter. The first sandwiching portion 61 is disposed on the radially outer side (outer peripheral side) of the second sandwiching portion 62, so that the axial direction of the drive shaft 32 is between the first sandwiching portion 61 and the second sandwiching portion 62. A clamping portion 64 that clamps (frictionally engages) the drive shaft 32 so as to be slidable and immovable in the radial direction is defined.

  As shown in FIG. 7C, the holding portion 64 does not hold the drive shaft 32, and the distance L5 between the inner surface of the first holding portion 61 and the outer surface of the second holding portion 62 is as follows. It is formed to be smaller than the outer diameter of the drive shaft 42.

  The elastic member 6 configured as described above is disposed so that the holding portion 63 is wound around the outer periphery of the barrel holder 5 and holds the barrel holder 5 by its elasticity, and also includes the first holding portion 61 and the first holding portion 61. The drive shaft 32 is clamped between the two clamping parts 62. Thereby, the barrel holder 5 is movably held on the drive shaft 32 of the actuator 3.

  Next, the cover 8 will be described with reference to FIGS. The cover 8 of this embodiment is formed by drawing and pressing a stainless steel thin plate of 0.1 mm to 0.2 mm, and includes a through hole 82 serving as an optical path in the upper wall 81.

  Further, the cover 8 is provided with a locking hole 84 for locking to a locking projection 20 f provided on the side surface of the actuator holder 2 on each of the four side walls 83. In this embodiment, the number of the locking projections 20f is two, and the locking projections 20f are locked with the two locking holes 84 facing each other.

  The cover 8 is placed on the mounting table 20e provided on the upper surface of each of the first support column 20a, the third support column 20c, and the fourth support column 20d of the actuator holder 2, and on the upper surface of the second support column 20b. In the state where the inner surface of the upper wall 81 of the cover 8 is in contact, the locking hole 84 and the locking projection 20f are locked.

  Further, in this locked state, the upper surface of the mounting table 20e and the second support pillar 20b and the inner surface of the upper wall 81 of the cover 8 are bonded and bonded together with an adhesive.

  Further, as shown in FIG. 2, the apparatus main body 1 a is provided with a sensor substrate 7 having an IR cut filter 71 and an image sensor 72 on the lower side of the actuator holder 2.

  The image sensor 72 is an image of each component of R (red), G (green), and B (blue) according to the amount of light in an optical image of an object (subject) imaged by an imaging optical system (not shown) as a whole. It is an element that photoelectrically converts a signal and outputs it to a predetermined image processing circuit (not shown). The imaging element 72 is, for example, a CCD type image sensor, a CMOS type image sensor, or the like.

  Next, the lens barrel 9 will be described. As shown in FIGS. 1, 9, and 11, the lens barrel 9 includes a cylindrical barrel main body 90 and a lens 12 held by the barrel main body 90. In this embodiment, the barrel main body 90 is formed by injection molding or the like with a material such as LCP mixed with glass fiber or the like as necessary.

  The barrel main body 90 includes a male screw portion 91 that is screwed into the female screw portion 51 of the barrel holder 5 on the outer peripheral surface thereof. The male screw portion 91 is a three-thread screw whose lead L is three times the pitch P. Each thread 91 a of the triple thread is composed of a triangular screw having the same shape as the thread of the female thread portion 51 of the barrel holder 5.

  Further, the barrel main body 90 has, at its lower end (one end), held stopper portions 91b and 92a (the shaded portions in FIG. 10) which are contacted and held against the stopper portion 52 of the barrel holder 5. I have. The stoppers 91b and 92a are formed on a vertical surface substantially perpendicular to the axial direction (optical axis direction) of the barrel holder 5.

  The stopper portion of this embodiment is composed of a multi-thread screw contact portion 91b formed on the male screw portion 91, and an end surface contact portion 92a formed on a part of the lower end surface 92 of the barrel main body 90. ing.

  Specifically, the lower end surface 92 of the barrel main body 90 is formed in a vertical plane substantially perpendicular to the axial direction (optical axis direction). The entire circumference of the radially outer portion of the lower end surface 92 forms an end surface abutting portion 92a.

  Each thread 91a of the male thread portion 91 is formed so as to spirally extend from the respective lower ends 92 of the barrel main body 90 to the upper end (the other end) in the axial direction. ing. And the whole of those start ends constitutes a multi-thread screw contact portion 91b. In addition, the multi-thread screw contact portions 91b are arranged at three equal intervals in the circumferential direction on the radially outer side of the lower end surface 92 of the barrel body 90 so that two adjacent central angles α are 120 °. ing.

  Moreover, as shown in FIG. 1, the barrel main body 90 is provided with a tool engaging portion 91c on the upper surface that is detachably engaged with the tool. The tool engaging portion 91c of this embodiment is formed so as to be recessed from the upper surface at three locations in the circumferential direction on the upper surface.

  The lens 12 forms an optical image of the object on the light receiving surface of the image sensor 72. The lens 12 may be a single lens or may include a plurality of lenses. The lens 12 may be, for example, a lens that moves along the optical axis to perform focusing (focusing), or a lens that moves along the optical axis to perform zooming (magnification), for example. It's okay. An optical image of the object is guided by the imaging optical system including the lens 12 to the light receiving surface of the imaging device 72 along the optical axis thereof, and the optical image of the object is captured by the imaging device 72. .

  The lens 12 is bonded to the inner peripheral side of the barrel main body 90 with, for example, an adhesive.

  In the lens barrel 9 configured as described above, the male screw portion 91 is screwed into the female screw portion 51 of the barrel holder 5. Then, the screwed lens barrel 9 is rotated with respect to the barrel holder 5 via a tool (not shown) engaged with the tool engaging portion 91c, for example.

  Then, the rotating operation is performed until the stoppers 91 b and 92 a of the lens barrel 9 come into contact with the stopper 52 of the barrel holder 5.

  At that time, since the male threaded portion 91 of the lens barrel 9 and the female threaded portion 51 of the barrel holder 5 are composed of three-threaded screws, the lead angle is higher than that of the single-threaded screw, so the amount of rotation is small. It can be screwed in, and the tact time of the assembling process can be shortened.

  Further, the stoppers 91b and 92a of the lens barrel 9 are provided with a multi-thread screw contact portion 91b composed of the start ends of three screw threads 91a arranged at equal intervals along the circumferential direction. The barrel 9 is positioned in parallel without the axial direction being inclined with respect to the axial direction of the barrel holder 5.

  For example, as shown in FIG. 15A, in the case of a comparative example provided with a lens barrel 109 having a single threaded male threaded portion 191 and a barrel holder 105 having a female threaded portion 151 screwed into the male threaded portion 191. The abutting stopper 152 has an opening inner diameter smaller than the inner diameter of the female screw portion 151 in order to stably abut the lens barrel 109 on the circumference, and the abutting stopper 191 a formed at one end of the lens barrel 109. Is configured to abut against the stopper 152.

  The comparative example having such a configuration has the following problems. That is, if the engagement allowance L6 (the length in the radial direction of the abutting part) of the stopper part 152 with the stopper part 191a is increased, the inner diameter of the opening of the stopper part 152 becomes small, and the optical path is restricted. In addition, since the outer diameter of the lens becomes small, it becomes difficult to design the F number to be small.

  On the other hand, when the engagement allowance L6 of the stopper portion 152 is decreased in order to increase the lens outer diameter, the contact stopper portion 191a of the lens barrel 109 comes into contact with the stopper portion 152 as shown in FIG. Will be screwed excessively and cannot be fixed in place. This is because the arm length of the stopper portion 152 (screw height L7 + engagement allowance L6, shown in FIG. 15A) is long with respect to the propelling force of the lens barrel 109 due to the torque when screwing the lens barrel 109. This occurs because the contact stopper 152 of the barrel holder 105 is easily deformed and the engagement allowance L6 is small, so that the torque change at the time of contact is small and the operator or the screwing device cannot be detected. For example, when the male screw portion 191 and the female screw portion 151 are M6P0.3, when the thread height L7 is set to 0.16 mm and the engagement allowance L6 is set to 0.2 mm, the arm length (screw height L7 + engagement allowance L6). Is 0.36 mm, and the lens outer diameter is 5.28 mm at the maximum.

  In that case, increasing the outer diameter itself of the barrel holder 105 leads to increasing the overall external dimensions of the imaging apparatus. Alternatively, the size of the actuator 3 is restricted, leading to insufficient driving force and deterioration of straightness.

  Further, in the case of forming a contact stop portion on the screw thread itself of the male screw portion 191 of the lens barrel 109 and bringing it into contact with the stop stop portion 152, the contact portion is only at one place on the circumference with a single thread screw. Therefore, the lens barrel 109 cannot be stably fixed, and the lens barrel 109 is inclined (tilt deterioration).

  In addition, it is possible to hold the lens position at a predetermined position by screwing rotation amount without providing the stopper part 152, and to fix the adhesive after inspection, but it is necessary to control the rotation amount and generate holding force. Therefore, there is a possibility that the lens barrel may rotate during the inspection and bonding process, and the posture of the lens barrel may be inclined due to the backlash between the female screw and the male screw part.

  On the other hand, in the present embodiment, as shown in FIG. 12, the engagement allowance L <b> 2 of the stopper portion 52 is substantially the same as the height L <b> 3 of the thread 91 a of the male screw portion 91, and the arm of the stopper portion 52. The length of is only the engagement margin L2, and the inner diameter L1 of the stopper 52 is increased and the length of the arm is shortened as compared with the comparative example shown in FIG. Therefore, when the lens barrel 9 is rotated, it is possible to reduce the risk that the stopper 52 is deformed. In addition, the axial direction of the lens barrel 9 is not inclined with respect to the axial direction of the barrel holder 5 by the three multi-thread screw contact portions 91 b arranged at equal intervals in the circumferential direction.

  For example, when the male thread portion 91 is an M6P0.3 screw and the engagement allowance L2 is set to 0.2 mm, in the comparative example, as described above, the arm length (screw height L7 + engagement allowance L6, FIG. Reference) is 0.36 mm and the maximum lens outer diameter is 5.28 mm. However, in this embodiment, the arm length can be 0.2 mm and the maximum lens outer diameter can be 5.6 mm. For a micro camera module, this difference has a great influence on image quality, size, or production stability as a design margin.

  In this way, the adhesive is filled in the vicinity of the tool engaging portion 91c in a state where the stoppers 91b and 92b of the lens barrel 9 and the stopper 52 of the barrel holder 5 are in contact with each other. 9 and the barrel holder 5 are bonded together.

  The image pickup apparatus 1 of the present invention configured as described above is provided, for example, on a circuit board of a cellular phone, on an external connection terminal 22b of the first electrode terminal 22 and an external connection terminal 23b of the second electrode terminal 23 (see FIG. 1 and the like). Is placed in the casing of the mobile phone.

  When electric power is supplied from the drive circuit to the external connection terminal 22b of the first electrode terminal 22 and the external connection terminal 23b of the second electrode terminal 23, the piezoelectric element 31 of the actuator 3 vibrates in the axial direction, and the vibration The drive shaft 32 reciprocates, and the barrel holder 5 moves in the axial direction (optical axis direction) of the drive shaft 32 by the reciprocation.

  More specifically, when a rectangular wave having a predetermined duty ratio is applied to the piezoelectric element 31, the displacement of the piezoelectric element 31 becomes a triangular wave, and the amplitude ratio is increased and decreased by changing the duty ratio of the rectangular wave. Triangular waves with different slopes are generated. The drive mechanism of the actuator 3 utilizes this.

  For example, when the drive shaft 32 is vibrated slowly, the barrel holder 5 that is frictionally engaged with the drive shaft 32 also moves in response to the vibration, and is driven instantaneously enough to exceed the frictionally engaged friction force. When the shaft 32 is vibrated, the barrel holder 5 is left as it is. By repeatedly performing such vibration in the axial direction of the drive shaft 32, the barrel holder 5 moves in the axial direction of the drive shaft 32.

  In the above embodiment, the stopper portion of the lens barrel 9 is composed of the multi-thread screw contact portion 91b and the end surface contact portion 92a. The stopper part may be constituted only by the multi-thread screw contact part 91b. Even in this case, the multi-thread screw contact portion 91b can clearly contact the barrel holder 5 at three equally spaced intervals on the circumference and can be positioned in parallel without inclination.

  In the above-described embodiment, the female screw portion 51 of the barrel holder 5 and the male screw portion 91 of the lens barrel 9 screwed to the barrel holder 5 are each constituted by a triangular screw having a triangular cross section. It can change suitably not only in a thing.

  For example, as shown in FIGS. 12 (a) and 12 (b), the female threaded portion 251 of the barrel holder 205 and the male threaded portion 291 of the lens barrel 209 screwed thereto have a thread cross section that conforms to, for example, JIS standards. It may be composed of trapezoidal trapezoidal screws as specified.

  With such a trapezoidal screw, as shown in FIG. 12 (c), the multiple threaded screw contact portion 291b formed from the start end of the thread 291a of the male threaded portion 291 and the end surface 292 in the radial outer side The area of the multi-thread screw abutting portion 291b in the to-be-stopped portion (shaded portion) composed of the contact portion 292a is larger than that in the case of the male screw portion 91 of the triangular screw of the above embodiment. Thereby, the lens barrel 209 is positioned and held in the barrel holder 205 more stably.

  In this case as well, the to-be-stopped portion may be composed only of the multi-thread screw abutting portion 291b.

  Further, as shown in FIGS. 13 (a) and 13 (b), the female threaded portion 351 of the barrel holder 305 and the male threaded portion 391 of the lens barrel 309 screwed thereto have a thread cross section, for example, JIS. It may be composed of rectangular square screws as defined in the standard.

  With such a square screw, as shown in FIG. 13 (c), a multi-thread screw abutting portion 391b that is the starting end of the thread 391a of the male screw portion 391, and an end face contact on the radially outer end face 392 are provided. The area of the multi-thread screw abutting portion 391b in the to-be-stopped portion (shaded portion) composed of the contact portion 392a is larger than that of the triangular screw male screw portion 91 or the trapezoidal screw male screw portion 391. growing. Thereby, the lens barrel 309 is positioned and held by the barrel holder 305 more stably.

  In this case as well, the to-be-stopped portion may be composed only of the multi-thread screw abutting portion 391b.

  Moreover, in the said embodiment, although the internal thread part 51 of the barrel holder 5 and the external thread part 91 of the lens barrel 9 screwed together were each comprised from the triple thread, it is not restricted to the thing of this form, It can be changed appropriately.

  For example, as shown in FIGS. 14A and 14B, the female threaded portion 451 of the barrel holder 405 and the male threaded portion 491 of the lens barrel 409 screwed to the barrel holder 405 are each composed of two threads, or 4 It may be composed of multiple or more threads (in FIG. 14, the case is composed of two threads).

  Even in this case, the multi-thread screw contact portion 491b formed from the start end of the screw thread 491a is formed at two places or four places or more in the circumferential direction, whereby the barrel holder 405 is positioned and positioned in the optical axis direction with respect to the image sensor. Are maintained in an accurate state, and the image quality of the imaging device can be improved. Further, the screwing torque of the lens barrel 409 with respect to the barrel holder 405 is smaller than that of the single thread screw and the amount of rotation is reduced, thereby improving the productivity.

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Actuator holder 3 Actuator 5,205,305,405 Barrel holder 6 Elastic member 8 Cover 9,209,309,409 Lens barrel 51,251,351,451 Female thread part (female thread part of a multi-threaded screw)
91,291,391,491 Male threaded part (Male threaded part of multiple threads)
91b, 291b, 391b, 491b Multi-thread screw contact part

Claims (4)

A lens barrel holding one or more lenses;
A cylindrical barrel holder holding the lens barrel;
The barrel holder includes a female thread portion of a multi-thread screw formed on an inner periphery thereof, and a stopper portion that is formed on one end side in the axial direction of the barrel holder and stops the lens barrel.
The lens barrel includes a male thread portion of a multi-threaded screw that is formed on an outer periphery of the lens barrel and is engaged with the female screw, and a stopper portion that contacts and stops against the stopper portion,
The abutted stopper includes a multi-thread screw contact portion formed at one end of the male screw portion so that one end of the male screw portion is a vertical surface substantially perpendicular to the optical axis direction. An imaging device that is characterized.   The imaging apparatus according to claim 1, wherein the female screw portion and the male screw portion are three or more multi-thread screws.   The imaging device according to claim 1, wherein the female screw portion and the male screw portion are square screws or trapezoidal screws.   The imaging apparatus according to claim 1, further comprising a drive member that moves the barrel holder in the optical axis direction.

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