JP6115847B2 - Camera module drive mechanism and leaf spring - Google Patents

Description

  The present invention relates to a camera module drive mechanism and a leaf spring, and more particularly to a camera module drive mechanism and a leaf spring that can be used in a small electronic device with a camera such as a camera-equipped mobile phone.

  Interaction between the current flowing in the coil and the magnetic field of the magnetic circuit composed of the yoke and magnet for the purpose of autofocusing and zooming in small electronic devices with cameras such as mobile phones, smartphones, tablet terminals, notebook PCs, etc. There is known a camera module drive mechanism (voice coil motor) that can displace the lens unit in the optical axis direction.

  A plate spring for supporting the holder holding the lens unit so as to be displaceable in the optical axis direction of the lens unit is used in such a camera module drive mechanism.

  By the way, the leaf spring is attached to a holder and a housing for holding the lens unit. For this reason, the leaf spring is provided with a positioning hole for attachment to the holder and the housing. By inserting positioning protrusions provided on the holder and the housing into the positioning holes, the leaf spring can be positioned on the holder and the housing, and the leaf spring is bonded to the holder and the housing with an adhesive.

  Further, the leaf spring is required to have a function of holding the holder for holding the lens unit movably with a stable spring constant with respect to the housing, but depending on the shape, adhesion strength and position of the adhesion portion of the leaf spring. The spring constant of the leaf spring may not be stable, and the holder that holds the lens unit may not be stably moved with respect to the housing.

  In general, the spring constant of a leaf spring is considered to be determined by factors such as the thickness, shape, length, and rigidity of the material constituting the leaf spring. However, in order for the leaf spring to have a stable spring constant after being mounted (the spring constant of each leaf spring product mounted on the voice coil motor is uniform), it is necessary in addition to the above factors. There are factors. In other words, it is necessary to reduce the variation of the part to which the leaf spring is bonded (the part to which the adhesive is attached) during mounting, to accurately align the length of the leaf spring arm (movable part), and the leaf spring is firmly fixed. It is necessary to be.

JP 2009-122360 A

  The present invention has been made in consideration of such points, and a holder for holding the lens unit can be obtained by firmly bonding the leaf spring to the housing or the holder, stabilizing the spring constant of the leaf spring. It is an object of the present invention to provide a camera module drive mechanism and a leaf spring that can move stably with respect to a housing.

  The present invention includes a housing, a lens unit that constitutes an optical system, a holder that is disposed in the housing, accommodates the lens unit, and is movable in the optical axis direction of the lens unit, a coil provided in the holder, A yoke and a magnet piece that are provided in the housing and provide a magnetic field to the coil, and are interposed between the housing and the holder, and include an outer frame portion on the housing side, an inner frame portion on the holder side, an inner frame portion, and an outer frame. A leaf spring having a spring portion between the inner portion and the outer portion of the leaf spring. The inner frame portion or the outer frame portion of the leaf spring has an adhesive portion for attaching the leaf spring to the housing or the holder, and the adhesive portion is opened. And a concave portion provided around the opening and recessed from one surface of the leaf spring toward the other surface.

  According to the present invention, there is provided a drive mechanism for a camera module, wherein a plurality of adhesive portions are provided at predetermined intervals, and the concave portions of the adhesive portions have the same area.

  The present invention is the camera module drive mechanism in which the adhesive portion is provided in the vicinity of the connecting portion with the spring portion of the inner frame portion or the outer frame portion of the leaf spring.

  The present invention is a camera module drive mechanism characterized in that a recess is roughened.

  The present invention is the camera module drive mechanism in which the bonding portion of the leaf spring is formed in one step together with the inner frame portion, the outer frame portion, and the spring portion.

  The present invention provides a leaf spring for use in a camera module drive mechanism, provided between an outer frame portion, an inner frame portion disposed inside the outer frame portion, and an inner frame portion and an outer frame portion. A spring part that expands and contracts the frame part and the inner frame part in the normal direction of the leaf spring, and the inner frame part or the outer frame part is an adhesive for attaching the leaf spring to the housing or holder of the drive mechanism of the camera module. The adhesive portion is a leaf spring characterized by having an opening and a recess provided around the opening and recessed from one surface of the leaf spring toward the other surface.

  The present invention is a leaf spring characterized in that a plurality of adhesive portions are provided at predetermined intervals, and the concave portions of the adhesive portions have the same area.

  The present invention is the leaf spring characterized in that the bonding portion is provided in the vicinity of the connecting portion with the spring portion of the inner frame portion or the outer frame portion of the leaf spring.

  The present invention is a leaf spring characterized in that the concave portion is roughened.

  The present invention is the leaf spring characterized in that the bonding portion of the leaf spring is formed in one step together with the inner frame portion, the outer frame portion and the spring portion.

  According to the present invention, the inner frame portion or the outer frame portion of the leaf spring has an adhesive portion for attaching the leaf spring to the housing or the holder, and the adhesive portion is provided around the opening portion and the opening portion. And a recess recessed from one surface of the leaf spring toward the other surface. Accordingly, the leaf spring can be firmly bonded to the housing or the holder, the spring constant of the leaf spring can be stabilized, and the holder that holds the lens unit can be stably moved with respect to the housing.

FIG. 1 is an exploded perspective view showing a drive mechanism of a camera module. FIG. 2 is a schematic side view showing the camera module. FIG. 3 is a plan view showing an upper leaf spring incorporated in the drive mechanism of the camera module. FIG. 4 is a plan view showing a lower leaf spring incorporated in the drive mechanism of the camera module. FIG. 5 is an enlarged view showing an adhesive portion of the upper leaf spring. 6 is a cross-sectional view showing a bonding portion of the upper leaf spring (a cross-sectional view taken along line AA in FIG. 5). FIG. 7 is an enlarged view showing an adhesive portion of the lower leaf spring. FIG. 8 is a cross-sectional view showing a bonding portion of the lower leaf spring (a cross-sectional view taken along line BB in FIG. 7). FIGS. 9A to 9C are enlarged views showing a modification of the bonding portion between the upper leaf spring and the lower leaf spring.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the camera module drive mechanism 1 according to the present invention includes a housing 2A composed of a cover 2 and a base 13, a lens unit 26A composed of a plurality of lenses 26 constituting an optical system, A holder 9 which is disposed in the housing 2A and accommodates the lens unit 26A and is movable in the optical axis direction of the lens unit 26A, a coil 8 provided on the outer periphery of the holder 9, and a base 13 of the housing 2A. A yoke 6 and a magnet piece 7 for providing a magnetic field to the coil 8 are provided.

  An upper leaf spring 5 is interposed between the cover 2 of the housing 2A and the upper portion of the holder 9, and a lower leaf spring 11 is interposed between the base 13 of the housing 2A and the lower portion of the holder 9.

  Then, when an electric current is passed through the coil 8 via the lower leaf spring 11, an upward force acts on the holder 9, and the lens unit 26A moves upward as a whole against the forces of the upper leaf spring 5 and the lower leaf spring 11. Can be lifted (see FIG. 2).

  Also, by adjusting the amount of current to be input, the force that moves the holder 9 upward is changed, and the balance between the force of the upper leaf spring 5 and the lower leaf spring 11 allows the holder 9 to move up and down. Position adjustment can be performed.

  As shown in FIG. 2, the housing 2 </ b> A is fixed above the base 20 via the intermediate support 21, and a glass plate 24 that holds an infrared cut glass 22 is supported on the intermediate support 21. An image sensor 25 is disposed above.

  Thus, the camera module 1A is configured by the drive mechanism 1 of the camera module having the housing 2A, the intermediate support 21 that supports the infrared cut glass 22 and the glass plate 24, and the base body 20 on which the imaging element 25 is disposed. Has been.

  In the above configuration, as shown in FIG. 3, the upper leaf spring 5 includes an outer frame portion 5a on the housing 2A side, an inner frame portion 5b on the holder 9 side, an outer frame portion 5a, and an inner frame portion 5b. And a spring portion 5c having a spring property provided between them. As shown in FIG. 4, the lower leaf spring 11 is provided between the outer frame portion 11a on the housing 2A side, the inner frame portion 11b on the holder 9 side, and between the outer frame portion 11a and the inner frame portion 11b. And a spring portion 11c having a spring property.

  Next, each component of the camera module drive mechanism 1 will be further described.

  As described above, the holder 9 holding the lens unit 26A is accommodated in the space in the housing 2A composed of the cover 2 and the base 13 so as to be displaceable in the optical axis direction of the lens unit 26A.

  An inner frame portion 5b of the upper leaf spring 5 and an inner frame portion 11b of the lower leaf spring 11 are attached to the upper and lower cylindrical edge portions of the holder 9, respectively, and the outer frame portion 5a of the upper leaf spring 5 (FIG. 3). Is attached to the upper surface of the yoke 6 fixed to the base 13 of the housing 2A, and the outer frame portion 11a (see FIG. 4) of the lower leaf spring 11 is attached to the base 13 of the housing 2A.

  A plurality of magnet pieces 7 are bonded to the yoke 6 to constitute a magnetic circuit of the drive mechanism 1 of the camera module. A coil 8 is disposed in the magnetic field formed by this magnetic circuit. The coil 8 is wound around the outer periphery of the holder 9, and the holder 9 can be displaced in the optical axis direction of the lens unit 26 </ b> A by supplying a current to the coil 8. In FIG. 2, a member indicated by reference numeral 12 is a conductor (flexible printed circuit board or the like) for supplying a current from an external power source to the coil 8, and a member indicated by reference numeral 4 is attached to the upper surface of the upper leaf spring 5. It is an adjustment plate.

  Next, the upper leaf spring 5 and the lower leaf spring 11 will be further described with reference to FIGS.

  As shown in FIG. 3, the upper leaf spring 5 includes a rectangular outer frame portion 5a, a ring-shaped inner frame portion 5b disposed on the holder 9 side and inside the outer frame portion 5a, an outer frame portion 5a, A spring portion 5c is provided between the inner frame portion 5b and has a spring property that expands and contracts the outer frame portion 5a and the inner frame portion 5b in the normal direction of the upper leaf spring 5.

  Positioning holes 17 for attaching the upper leaf springs 5 to the upper surface of the yoke 6 fixed to the base 13 of the housing 2A are provided in three of the four corners of the outer frame portion 5a. The positioning hole 17 is engaged with a positioning protrusion (not shown) provided on the upper surface side of the yoke 6 to accurately position the upper leaf spring 5 on the upper surface side of the yoke 6.

  Further, the outer frame portion 5a is provided with an adhesive portion 30A for attaching the upper leaf spring 5 to the housing 2A. The adhesive portions 30A are provided at the four corners of the outer frame portion 5a and in the vicinity of the connecting portion between the outer frame portion 5a and each spring portion 5c. A plurality (four) of the bonding portions 30A are provided at predetermined intervals in the circumferential direction of the outer frame portion 5a.

  As shown in FIGS. 5 and 6, each adhesive portion 30 </ b> A is provided so as to surround a circular opening 31 </ b> A and the periphery of the opening 31 </ b> A, and is fixed to the back surface of the upper leaf spring 5 (the base 13 of the housing 2 </ b> A). A recessed portion 32A that is recessed from the surface on the yoke 6 side) to the surface (the surface opposite to the yoke 6 fixed to the base 13 of the housing 2A). The recess 32A has an annular top surface 33A and a cylindrical side surface 34A extending from the top surface 33A. The recess 32A is formed of a thin portion formed thinner than the entire thickness of the upper leaf spring 5. In each bonding part 30 </ b> A, an adhesive (not shown) flows from the opening 31 </ b> A and spreads inside the recess 32 </ b> A, whereby the upper leaf spring 5 is bonded to the upper surface of the yoke 6.

  The planar shape of the recess 32A may be a circle as shown in FIG. 5, but is not limited to this, and is not limited to a triangle (FIG. 9A), a rectangle (FIG. 9B), or the like. A polygon, an ellipse, etc. may be sufficient. Alternatively, the planar shape of the recess 32A may be a shape including a circular portion and a rectangular portion connected to the circular portion (FIG. 9C). Moreover, the recessed part 32A should just be connected with the opening part 31A, and you may arrange | position the recessed part 32A which has arbitrary shapes in the place which kept fixed positional relationship (distance, direction, etc.) from the opening part 31A.

  Thus, as a method of forming the thin-walled recess 32A around the back surface of the opening 31A, for example, half-etching can be mentioned. In this case, the opening 31A and the recess 32A of the bonding part 30A are simultaneously formed in one process together with the inner frame part 5b, the outer frame part 5a, and the spring part 5c.

  When the recess 32A is formed by half-etching, it can be processed using the same plate making as the outer frame portion 5a, the inner frame portion 5b, and the spring portion 5c of the upper leaf spring 5. The positional relationship among the frame portion 5a, the inner frame portion 5b, the spring portion 5c, and the bonding portion 30A can be strictly matched. As a result, it is possible to prevent the spring constants of the upper leaf spring 5 and the lower leaf spring 11 from fluctuating as the plate-making fixing position is shifted.

In FIG. 6, the thickness d ₁ of the entire upper leaf spring 5 can be set to 20 μm or more and 150 μm or less, for example. In particular, the thickness d ₁ is preferably 20 μm to 50 μm. The thickness _{d 2} of the upper plate spring 5 in凹部32A may be, for example, 20% to 60% of the upper leaf spring 5 the total thickness _{d 1.} In FIG. 6, the upper leaf spring 5 is drawn exaggerated in the thickness direction.

  The top surface 33A of the recess 32A may be smooth, or may be roughened. As a method for roughening the top surface 33A of the recess 32A, for example, a microetching method can be exemplified. Thus, when the top surface 33A of the recess 32A is roughened, the adhesive strength between the upper leaf spring 5 and the housing 2A can be further increased.

  Note that the opening 31 </ b> A of each bonding portion 30 </ b> A may function as a positioning hole when the upper leaf spring 5 is attached to the holder 9. In this case, the opening 31 </ b> A can engage with a positioning protrusion (not shown) provided on the holder 9 side to accurately position the upper leaf spring 5 on the holder 9 side. Alternatively, a positioning hole (not shown) may be separately provided around each adhesive portion 30A in addition to the opening portion 31A.

  Furthermore, it is preferable that the concave portions 32A of the four adhesive portions 30A have the same shape and the same area. As a result, the spring constant of the upper leaf spring 5 determined by the four spring portions 5c can be further stabilized.

  On the other hand, the inner frame portion 5 b is provided with an adhesive portion 30 </ b> B for attaching the upper leaf spring 5 to the holder 9. The adhesive portions 30B are provided at the four corners of the inner frame portion 5b and in the vicinity of the connecting portion between the inner frame portion 5b and each spring portion 5c. A plurality (four) of the bonding portions 30B are provided at predetermined intervals in the circumferential direction of the inner frame portion 5b.

  As shown in FIGS. 5 and 6, each bonding portion 30 </ b> B is provided so as to surround the circular opening 31 </ b> B and the periphery of the opening 31 </ b> B, and from the back surface (the surface on the holder 9 side) of the upper leaf spring 5 ( It has a recess 32B that is recessed toward the holder 9 and the opposite surface. The recess 32B has an annular top surface 33B and a cylindrical side surface 34B extending from the top surface 33B. The recess 32B is formed of a thin part formed thinner than the entire thickness of the upper leaf spring 5. In each bonding portion 30B, an adhesive (not shown) flows from the opening 31B and expands inside the recess 32B of the opening 31B, whereby the upper leaf spring 5 is bonded to the holder 9.

  The planar shape of the recess 32B may be circular as shown in FIG. 5, but is not limited thereto, and may be a polygon such as a triangle or a rectangle, an ellipse, or the like. Moreover, the recessed part 32B should just be connected with the opening part 31B, and you may arrange | position the recessed part 32B which has arbitrary shapes in the place which kept fixed positional relationship (distance, direction, etc.) from the opening part 31B.

  As a method for forming the thin-walled recess 32B around the back surface of the opening 31B in this way, for example, half-etching can be mentioned. In this case, the opening 31B and the recess 32B of the bonding part 30B are simultaneously formed in one step together with the inner frame part 5b, the outer frame part 5a, and the spring part 5c.

  When the concave portion 32B is formed by half-etching, it can be processed using the same plate making as the outer frame portion 5a, the inner frame portion 5b, and the spring portion 5c of the upper leaf spring 5, and the outer leaf spring 5 The positional relationship among the frame portion 5a, the inner frame portion 5b, the spring portion 5c, and the bonding portion 30B can be strictly matched. As a result, it is possible to prevent fluctuations in the spring constants of the upper leaf spring 5 and the lower leaf spring 11 due to the shift of the fixed position of the plate making.

In FIG. 6, the thickness d ₃ of the upper leaf spring 5 in the recess 32 </ b> B can be set to, for example, 20% to 60% of the thickness d ₁ of the entire upper leaf spring 5.

  The top surface 33B of the recess 32B may be smooth, or may be roughened. As a method for roughening the top surface 33B of the recess 32B, for example, a microetching method can be exemplified. Thus, when the top surface 33B of the recess 32B is roughened, the adhesive strength between the upper leaf spring 5 and the holder 9 can be further increased.

  Furthermore, it is preferable that the concave portions 32B of the four bonding portions 30B have the same shape and the same area. As a result, the spring constant of the upper leaf spring 5 determined by the four spring portions 5c can be further stabilized.

  The opening 31B of each bonding portion 30B may function as a positioning hole when the upper leaf spring 5 is attached to the holder 9. In this case, the opening 31 </ b> B can engage with a positioning protrusion (not shown) provided on the holder 9 side to accurately position the upper leaf spring 5 on the holder 9 side. Or you may provide a positioning hole (not shown) separately around each adhesion part 30B other than the opening part 31B.

  As described above, the adhesive portions 30A and 30B of the upper leaf spring 5 are provided around the openings 31A and 31B and the back surfaces of the openings 31A and 31B, respectively, and are recessed portions 32A that are recessed from the rear surface of the upper leaf spring 5 toward the front surface side. , 32B. Thus, both end portions of the spring portion 5c having spring properties can be firmly fixed to the housing 2A and the holder 9 respectively. That is, since the recesses 32A and 32B are provided on the back surfaces around the openings 31A and 31B, the adhesive flowing in from the openings 31A and 31B spreads into the recesses 32A and 32B. The bonding area between the body 2A and the holder 9 can be increased, and the bonding strength between the upper leaf spring 5, the housing 2A and the holder 9 can be increased.

  Moreover, the spring constant of the spring part 5c can be stabilized by fixing the both ends of the spring part 5c of the upper leaf spring 5 to the housing 2A and the holder 9 with high strength in this way. Further, a plurality of adhesive portions 30A and 30B are provided at predetermined intervals, and the recesses 32A and 32B of the adhesive portions 30A and 30B have the same area, thereby further stabilizing the spring constant of the spring portion 5c. it can.

  Next, the lower leaf spring 11 will be described with reference to FIGS. 4, 7 and 8. In this case, the lower leaf spring 11 has substantially the same shape as the upper leaf spring 5 except that the direction of the opening 32B of the bonding portion 30B is reversed. In the lower leaf spring 11 shown in FIGS. 4, 7, and 8, the same components as those of the upper leaf spring 5 shown in FIGS. 3, 5, and 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the lower leaf spring 11 includes a rectangular outer frame portion 11a, a ring-shaped inner frame portion 11b disposed on the holder 9 side and inside the outer frame portion 11a, and an outer frame portion 11a. A spring portion 11c is provided between the inner frame portion 11b and has a spring property that expands and contracts the outer frame portion 11a and the inner frame portion 11b in the normal direction of the lower leaf spring 11.

  Among these, the outer frame portion 11a is provided with an adhesive portion 30A for attaching the lower leaf spring 11 to the base 13 of the housing 2A. The adhesive portions 30A are provided at the four corners of the outer frame portion 11a and in the vicinity of the connecting portion between the outer frame portion 11a and the spring portion 5c. A plurality (four) of the bonding portions 30A are provided at predetermined intervals in the circumferential direction of the outer frame portion 11a.

  As shown in FIGS. 7 and 8, each adhesive portion 30A is provided so as to surround the circular opening 31A and the periphery of the opening 31A, and the back surface of the lower leaf spring 11 (the surface on the base 13 side of the housing 2A). ) To the front surface (surface opposite to the base 13 of the housing 2A) side. In each bonding portion 30A, an adhesive (not shown) flows from the opening 31A and spreads inside the recess 32A, whereby the lower leaf spring 11 is bonded to the base 13 of the housing 2A.

  On the other hand, the inner frame portion 11 b is provided with an adhesive portion 30 </ b> B for attaching the lower leaf spring 11 to the holder 9. The adhesive portion 30B is provided in the vicinity of the connecting portion with the spring portion 11c in the inner frame portion 11b. A plurality (four) of the bonding portions 30B are provided at predetermined intervals in the circumferential direction of the inner frame portion 11b.

  As shown in FIGS. 7 and 8, each bonding portion 30B is provided so as to surround a circular opening 31B and the periphery of the opening 31B, from the surface of the lower leaf spring 11 (the surface on the holder 9 side) to the back surface (the surface of the holder 9). It has a recess 32B that is recessed toward the holder 9 and the opposite surface. In each bonding portion 30B, an adhesive (not shown) flows from the opening 31B and spreads inside the recess 32B of the opening 31B, whereby the lower leaf spring 11 is bonded to the holder 9.

  The configurations of the bonding portion 30A and the bonding portion 30B of the lower leaf spring 11 are the bonding portion 30A and the bonding portion 30B of the upper leaf spring 5 described above, respectively, except that the direction of the opening 32B of the bonding portion 30B is reversed. Therefore, detailed description thereof is omitted here.

  As described above, the bonding portion 30A of the lower leaf spring 11 includes the opening portion 31A and the recess portion 32A that is provided around the back surface of the opening portion 31A and is recessed from the back surface of the lower leaf spring 11 toward the front surface side. The bonding portion 30B of the lower leaf spring 11 includes an opening 31B and a recess 32B that is provided around the surface of the opening 31B and is recessed from the surface of the lower leaf spring 11 toward the back surface. Thus, both end portions of the spring portion 11c having spring properties can be firmly fixed to the base 13 and the holder 9 of the housing 2A. That is, since the recesses 32A and 32B are provided around the openings 31A and 31B, the adhesive flowing in from the openings 31A and 31B spreads into the recesses 32A and 32B. The bonding area between the base 13 and the holder 9 can be increased, and the bonding strength between the lower leaf spring 11 and the base 13 and the holder 9 of the housing 2A can be increased.

  Moreover, the spring constant of the spring part 11c can be stabilized by fixing both ends of the spring part 11c of the lower leaf spring 11 to the housing 2A and the holder 9 with high strength in this way. Further, a plurality of bonding portions 30A and 30B are provided at predetermined intervals, and the recesses 32A and 32B of the bonding portions 30A and 30B have the same area, thereby further stabilizing the spring constant of the spring portion 11c. it can.

  In FIG. 4, the outer frame portion 11a of the lower leaf spring 11 is provided with a pair of connection terminals 11e and 11e connected to an external power source. Further, the inner frame portion 11b is provided with a pair of connection terminals 11d and 11d connected to the coil 8 side, and current can flow from the external power source to the coil 8 side via the lower leaf spring 11.

As shown in FIG. 4, the outer frame portion 11a is composed of a pair of outer frame members 11a ₁ and 11a ₂ spaced apart from each other, so that the connection terminals 11e and 11e are not short-circuited. The inner frame portion 11b is composed of a pair of inner frame members 11b ₁ and 11b ₂ that are spaced apart from each other, so that the connection terminals 11d and 11d are not short-circuited.

  Next, materials for the upper leaf spring 5 and the lower leaf spring 11 will be described. Both the upper leaf spring 5 and the lower leaf spring 11 are produced by etching or punching a metal plate made of a copper alloy (beryllium copper, nickel tin copper, titanium copper, or other copper alloy). When using it as a part of conductor which sends the electric current from an external power supply to the coil 8, a material with good electrical conductivity is preferable. From the viewpoint of spring characteristics, hardness or tensile strength may be emphasized. When not used as part of a conductor for supplying current from an external power source to the coil 8, stainless steel alloys (SUS304, SUS316, TS- The upper leaf spring 5 and the lower leaf spring 11 may be made from a hard metal plate such as 4).

(Operation of this embodiment)
Next, the operation of the present embodiment having such a configuration will be described.

  First, a current is passed through the coil 8 through the lower leaf spring 11. As a result, an upward force acts on the holder 9, and the lens unit 26A can be lifted upward as a whole against the forces of the upper leaf spring 5 and the lower leaf spring 11 (see FIG. 2).

  Further, by adjusting the amount of current flowing through the coil 8, the force that moves the holder 9 upward is changed, and the balance between the force of the upper leaf spring 5 and the lower leaf spring 11 is made, so that the holder 9 moves up and down. And its position can be adjusted.

  In this case, an adhesive portion 30A is provided in the vicinity of the connecting portion with the spring portions 5c and 11c of the outer frame portions 5a and 11a of the upper plate spring 5 and the lower plate spring 11, and the spring portions 5c and 11b of the inner frame portions 5b and 11b. An adhesive portion 30B is provided in the vicinity of the connecting portion with 11c. Furthermore, the bonding portions 30A and 30B include openings 31A and 31B and recesses 32A and 32B that are provided around the openings 31A and 31B and are recessed from one surface of the upper leaf spring 5 toward the other surface. As a result, the bonding area when the upper plate spring 5 and the lower plate spring 11 are bonded to each of the yoke 6, the base 13 and the holder 9 fixed to the base 13 of the housing 2A can be increased. The spring 5 and the lower leaf spring 11 can be firmly fixed to each of the yoke 6, the base 13 and the holder 9 fixed to the base 13 of the housing 2A.

  Thus, by firmly fixing both ends of the spring portions 5c and 11c of the upper leaf spring 5 and the lower leaf spring 11 to each of the yoke 6, the base 13 and the holder 9 fixed to the base 13 of the housing 2A, The spring constant of the spring parts 5c and 11c can be stabilized.

  Thus, a camera module drive mechanism having stable spring characteristics can be obtained.

  Specifically, when a current is passed through the coil 8 via the lower leaf spring 11, an interaction occurs between the current and the magnetic field of the magnet 7, and the holder 9 moves up and down. At this time, the upper leaf spring 5 and the lower leaf spring 11 suppress the movement of the holder 9 according to the spring constant k.

  In this case, three elements (i) (ii) (iii) consisting of (i) a current flowing through the coil 8, (ii) a magnetic force of the magnet 7, and (iii) a spring constant of the upper leaf spring 5 and the lower leaf spring 11 ), The focus of the lens unit 26A can be adjusted by moving the holder 9 up and down and adjusting its position.

  Therefore, in order to perform the adjustment with the lens unit 26A with high accuracy, it is required to determine the above three elements (i), (ii), and (iii), particularly the element (iii) with high accuracy and to design stably. Yes.

  According to the present invention, among the above three elements (i), (ii), and (iii), by stabilizing the spring constant of the spring portions 5c and 11c as described above, in particular, (iii) the upper leaf spring 5 In addition, the spring constant of the lower leaf spring 11 can be stabilized. Accordingly, the vertical movement of the holder 9 and the position adjustment thereof can be performed with high accuracy, and the focal point by the lens unit 26A can be adjusted with high accuracy.

  That is, according to the present invention, the positional relationship (distance and direction, etc.) between the connecting portions of the spring portions 5c and 11c and the outer frame portions 5a and 11a (inner frame portions 5b and 11b) and the bonding portions 30A and 30B. ) Is made uniform, the substantial length of each spring portion 5c, 11c can be made uniform, and fluctuations in the spring constant can be suppressed. Thereby, the quality dispersion | variation for every product of camera module 1A can be suppressed.

DESCRIPTION OF SYMBOLS 1 Camera module drive mechanism 1A Camera module 2 Cover 2A Housing | casing 3 Stopper 4 Bridge | crosslinking part support member 5 Upper leaf | plate spring 5a Outer frame part 5b Inner frame part 5c Spring part 6 Yoke 7 Magnet piece 8 Coil 9 Holder 11 Lower leaf | plate spring 11a Outer frame portion 11b Inner frame portion 11c Spring portion 12 Flexible printed circuit board 13 Base 17 Positioning hole 20 Base 21 Intermediate support 22 Infrared cut glass 24 Glass plate 25 Imaging element 26 Lens 26A Lens unit 30A, 30B Bonding portion 31A, 31B Opening portion 32A, 32B Recess 33A, 33B Top surface 34A, 34B Side surface

Claims (5)

In the leaf spring used for the drive mechanism of the camera module,
An outer frame,
An inner frame disposed inside the outer frame,
A spring part provided between the inner frame part and the outer frame part, and extending and contracting the outer frame part and the inner frame part in the normal direction of the leaf spring;
The inner frame part or the outer frame part has an adhesive part for attaching the leaf spring to the housing or holder of the drive mechanism of the camera module,
Adhesive portion includes a opening therethrough in the thickness direction of the plate spring, it is provided in communication with Oite opening around the opening, of one of the two surfaces of the leaf spring perpendicular to the thickness direction of the plate spring seen concave toward the surface on the other side, a leaf spring, characterized in that consists of a concave portion is thinly formed thin portion than the thickness of the leaf spring.   2. The leaf spring according to claim 1, wherein a plurality of adhesive portions are provided at predetermined intervals, and the concave portions of the adhesive portions have the same area.   The leaf spring according to claim 1 or 2, wherein the bonding portion is provided in the vicinity of a connecting portion with the spring portion of the inner frame portion or the outer frame portion of the leaf spring.   The leaf spring according to any one of claims 1 to 3, wherein the concave portion is roughened.   5. The leaf spring according to claim 1, wherein the bonding portion of the leaf spring is formed in one step together with the inner frame portion, the outer frame portion, and the spring portion.

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