JP2011099900A - Lens unit, image pickup device using the same, and method for connecting optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain errors due to adhesion in a lens unit composed of multiple sheets of optical elements. <P>SOLUTION: A first group unit 2 is formed by connecting a plurality of optical elements 21, 22 and 23 having holding parts 212, 222 and 232 in lens parts 211, 221 and 231 which form an optical path. In this case, an adhesive 28 is applied to the adhesive-applying faces 212d, 222d; 222e; and 232e of the holding parts 212, 222 and 232, and, when they are mutually bonded, groove parts 212f; 222f, 222g; and 232g are formed between the contacting faces 212b; 222b, 222c; and 232c, which stipulate the intervals of the optical elements 21, 22 and 23, and the adhesive-applying faces 212d, 222d; 222e; and 232e. Accordingly, when the optical elements are pressed, the excessive adhesive flows into the groove parts 212f; 222f, 222g; and 232g as shown by a reference code 28a, and the adhesive 28 is prevented from protruding out to the contacting faces 212b; 222b, 222c; and 232c. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a small lens unit suitably used for an imaging device of a mobile phone, particularly using a plastic lens, an imaging device using the same, and a method for joining optical elements.

  In a small lens unit used for an imaging device of a cellular phone, the plastic lens suitable for miniaturization and weight reduction is used and fixed to a lens holding frame such as a housing by adhesion. At that time, it is necessary to take measures to prevent the adhesive from flowing into the effective diameter of the lens. Therefore, in Patent Document 1, when mounting the lens on the stepped surface on the tip side of the cylindrical holding frame, an annular groove is formed on the bottom surface of the stepped surface, and the outer peripheral side of the edge of the groove is formed. Is formed one step lower, an annular groove is formed on the bottom surface of the lens, and the inner wall of the groove is inclined so that the groove is filled with an adhesive. Is mounted on the step surface, and the overflowing adhesive is released to the lens outer peripheral side and fixed.

JP 2002-303773 A

  In the above-described prior art, since the adhesive is applied to the groove, if the groove width cannot be widened with a small diameter lens, the adhesive strength cannot be obtained, and it is difficult to apply the adhesive only to the groove part. There is a problem that the adhesive eventually protrudes into the effective diameter of the lens. As a result, the air gap error and tilt error increase due to the thickness variation of the protruding adhesive, which is one of the factors that hinder the optical performance. On the other hand, if the amount of the adhesive is reduced in consideration of the protrusion, the adhesive is present only at the bottom of the groove, and a portion that does not come into contact with the bottom surface of the lens is generated, and the entire circumference is uniform and sufficient. Adhesive strength cannot be obtained.

  An object of the present invention is to provide a lens unit capable of ensuring optical performance while simply and firmly joining optical elements including a lens portion, an imaging apparatus using the lens unit, and a method for joining optical elements. .

  The lens unit of the present invention is a lens unit in which a plurality of optical elements are joined to each other, and each optical element includes a lens part that forms an optical path and a holding part that holds the lens part from the outer peripheral side. The holding portion has an abutment surface that defines an interval between the lens portions of optical elements adjacent to each other, and an adhesive application surface that opposes at a predetermined interval, and is adjacent to each other. In the holding portion of at least one of the optical elements, the circumferential direction is used to prevent the adhesive from entering the contact surface side from the adhesive application surface at the boundary between the contact surface and the adhesive application surface. An extending groove is formed.

  According to the above configuration, in a lens unit formed by joining a plurality of optical elements to each other, each optical element is a plastic lens or the like, and each optical element forms an optical path and at least a part of the outer peripheral edge of the lens part. In the case where it is configured with a holding portion made of a holding piece or the like extending from or from a glass lens, etc. When the adhesive is applied to the adhesive application surface that is opened and opposed, the abutment surface is brought into contact with each other and the distance between the lens portions is regulated and fixed to each other, at least one of the optical elements adjacent to each other In the holding portion, in order to prevent the adhesive from entering from the adhesive application surface to the contact surface side, a groove portion extending in the circumferential direction is formed at the boundary between them.

  Therefore, the adhesive is applied to the adhesive application surface of at least one holding part, the adjacent optical elements are pressed against each other, and the adhesive is cured by heating, ultraviolet irradiation, etc. Therefore, it is possible to join easily and firmly. Further, the excess adhesive flows into the groove during the pressing, thereby preventing the adhesive from protruding to the contact surface, and an extra error in the distance between the lenses. Optical performance can be ensured without riding.

  In the lens unit of the present invention, in the holding portion, the contact surface is disposed on the outer peripheral side, and the adhesive application surface is disposed on the inner peripheral side.

  According to said structure, by defining the space | interval of the said lens parts on the outer peripheral side of the said holding | maintenance part, the space | interval (span) of the said contact surface is expanded rather than prescribing | regulating on the inner peripheral side, and it depends on manufacturing error The distance error (including inclination) and eccentricity can be further reduced, and excess adhesive can be prevented from protruding from the outer peripheral side of the holding portion. Assembly to the holder can be performed accurately.

  Furthermore, in the lens unit of the present invention, the groove portion is also formed on the lens portion side of the holding portion.

  According to said structure, by forming the said groove part also in the innermost periphery vicinity of the said holding | maintenance part, the protrusion of the excess adhesive agent to the said lens part side can be prevented, and optical performance is ensured. be able to.

  In the lens unit of the present invention, the optical element is made of a plastic lens, and the lens portion and the holding portion are integrally molded.

  According to the above configuration, when the lens portion is made of a glass lens as described above, the holding frame serving as the holding portion is often provided as a separate body, and the holding frame is bonded and fixed as described above. On the other hand, when the lens portion is made of a plastic lens, the holding portion is made of a holding piece extending from at least a part of the outer peripheral edge of the lens portion. Thus, there is no need to use a separate holding frame for bonding between the optical elements.

  Furthermore, in the lens unit of the present invention, among the holding portions of the optical elements adjacent to each other, one of the groove portions is formed in an annular shape, and the other is formed with a protrusion or protrusion that loosely fits in the groove portion. The inner diameter of the groove is larger than the outer diameter of the protrusion or protrusion by a predetermined dimension.

  According to the above configuration, when mounting the optical elements, the groove into which the excess adhesive flows is formed in one of the holding parts of the optical elements adjacent to each other in a large ring shape, and on the other side. By forming protrusions or ridges on the small side, when the two are bonded, the protrusions or ridges fit into the grooves while preventing the excess adhesive from overflowing the grooves by the protrusions or ridges. To. The relationship between the protrusions or ridges and the grooves is formed by making the inner diameter of the grooves larger than the outer diameter of the protrusions or ridges by a predetermined dimension, thereby providing play, that is, adjacent to each other. A deviation between the optical elements in the direction orthogonal to the optical axis is allowed.

  Therefore, by adjusting the deviation, alignment between optical elements can be performed, and after the alignment, the adhesive is cured and fixed, so that an alignment lens frame that has been conventionally used can be obtained. Can be abolished.

  In addition, the lens unit of the present invention is a lens unit formed by joining an optical element having a lens part, an outer edge part extending to the outer peripheral side of the lens part, and a holding member that holds the optical element. The member has a contact surface that contacts the outer edge portion and performs positioning in the optical axis direction, and an adhesive application surface on which the adhesive is to be applied, facing the outer edge portion at a predetermined interval. A groove extending in the circumferential direction is formed at the boundary between the contact surface and the adhesive application surface in order to prevent entry of the adhesive from the adhesive application surface to the contact surface side. To do.

  According to said structure, the lens unit formed by joining the optical element which has a lens part and the outer edge part extended to the outer peripheral side of the lens part to holding members, such as a lens-barrel and a lens frame which hold | maintains it. In this case, an adhesive is applied to the adhesive application surfaces facing each other at a predetermined interval, and the contact surfaces are brought into contact with each other to perform positioning in the optical axis direction with respect to the holding member of the optical element. In order to adhere and fix each other, in the holding member, in order to prevent the adhesive from entering the contact surface side from the adhesive application surface, a groove portion extending in the circumferential direction is formed at the boundary between them.

  Therefore, after applying an adhesive to at least one of the outer edge portion of the optical element and the holding member, the adhesive is cured by applying pressure to each other and heating or irradiating ultraviolet rays, so that the optical element is attached to the holding member. At the time of the pressing, the excess adhesive flows into the groove, thereby preventing the adhesive from protruding to the contact surface, and the optical element holding member. The optical performance can be ensured without adding an extra error to the mounting.

  Furthermore, the image pickup apparatus of the present invention includes the image pickup device using the lens unit as at least one of an object side lens unit movable in the optical axis direction and a fixed image side lens unit. It is characterized by.

  According to said structure, the imaging device which can ensure optical performance can be implement | achieved, joining between lenses simply and firmly.

  As described above, the lens unit of the present invention is a lens unit in which a plurality of optical elements are joined to each other, and each optical element is integrally formed with a lens portion that forms an optical path with a plastic lens or the like. When configured with a holding unit, or when configured with a glass lens or the like and a holding unit made of a lens unit and a holding frame, an adhesive is applied to the adhesive application surface of the holding unit. When the contact surfaces are brought into contact with each other and the distance between the lens portions is regulated and fixed to each other, at least one of the holding portions of the optical elements adjacent to each other, the contact from the adhesive application surface In order to prevent the adhesive from entering the surface side, circumferentially extending grooves are formed at the boundary between them.

  Therefore, the optical elements can be easily and firmly joined to each other by mounting. Furthermore, the surplus adhesive at the time of bonding flows into the groove portion, thereby preventing the adhesive from protruding to the contact surface, and an extra error is added to the distance between the lens portions. And optical performance can be ensured.

  In addition, as described above, the lens unit of the present invention is a holding member such as a lens barrel or a lens frame that holds an optical element having a lens portion and an outer edge portion extending to the outer peripheral side of the lens portion. In the lens unit formed by bonding to each other, the adhesive is applied to the adhesive application surface at the joint, and the contact surface is contacted to position the optical element on the holding member in the optical axis direction. In order to prevent the adhesive from penetrating from the adhesive application surface to the contact surface side, a groove extending in the circumferential direction is formed at the boundary of the holding member.

  Therefore, the excess adhesive during the bonding flows into the groove, thereby preventing the adhesive from protruding to the abutting surface, which is unnecessary for attaching the optical element to the holding member. Optical performance can be ensured without any error.

  Furthermore, as described above, the imaging apparatus of the present invention uses the lens unit as at least one of an object side lens unit movable in the optical axis direction and a fixed image side lens unit.

  Therefore, it is possible to realize an imaging apparatus that can ensure optical performance while simply and firmly joining the lenses.

It is a longitudinal cross-sectional view of the imaging device which concerns on one Embodiment of this invention. It is a disassembled perspective view of the said imaging device. It is the perspective view which decomposed | disassembled FIG. 2 further finely. It is a figure which expands and shows the cross section in the cutting surface line IV-IV of FIG. 1, and shows the joining structure with respect to the holding member of the lens unit which concerns on one Embodiment of this invention. FIG. 5 is a cross-sectional view showing the structure when there are two lenses with respect to FIG. 4. FIG. 5 is a cross-sectional view showing a structure when the present embodiment is used for bonding a lens and a ball frame to FIG. 4. It is sectional drawing which expands and shows the part shown with the referential mark (alpha) in FIG. 1, and shows the ventilation structure which concerns on one Embodiment of this invention. It is a figure of some optical elements. It is a perspective view which shows the application | coating state of the adhesive agent for implement | achieving the said ventilation | gas_flowing structure. It is a perspective view which shows the assembly state of the flame | frame before and behind except an internal structure. It is a figure of a back frame. It is a figure of a front frame. It is sectional drawing which shows the structure of the jig | tool which adheres while adjusting the attachment angle of an ultrasonic linear actuator. It is typical sectional drawing which expands and shows the mode at the time of shaping | molding of a back frame. It is a typical top view which shows the mode at the time of shaping | molding of a back frame. It is a typical top view which shows the mode at the time of shaping | molding of a back frame. It is sectional drawing at the time of the other frame structure and its shaping | molding. It is typical sectional drawing which expands and shows the mode at the time of shaping | molding of a front frame. It is sectional drawing which shows typically the mode at the time of the assembly | attachment of the ultrasonic linear actuator with respect to the said front frame. It is sectional drawing for demonstrating routing of the lead wire of an ultrasonic linear actuator. It is sectional drawing seen from the cut surface line XXI-XXI of FIG. It is a front view for demonstrating the holding structure of 1st group unit. FIG. 23 is an exploded perspective view of FIG. 22. It is a front view which shows the holding structure by the other press member corresponding to FIG. It is sectional drawing seen from the cut surface line XXV-XXV of FIG. It is a front view which shows the holding structure by the other holding member and press member corresponding to FIG. FIG. 26 shows a holding structure with another pressing member corresponding to FIG. 25. FIG. 26 shows a holding structure with still another pressing member corresponding to FIG. 25.

  FIG. 1 is a longitudinal sectional view of an imaging apparatus 1 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a further exploded perspective view. This imaging apparatus 1 includes a first group unit 2 that is a moving lens unit, a second group unit 3 that is a fixed lens unit, an ultrasonic linear actuator 4 that drives the first group unit 2 in the optical axis direction, and these units. 2 and 3, and a housing 5 that accommodates the ultrasonic linear actuator 4, a filter 6, and an image sensor 7.

  The image pickup apparatus 1 is mounted on a terminal device of a mobile phone, and the image pickup element 7 is composed of a CCD type or CMOS type image sensor and is mounted on a printed circuit board on the terminal device side. The filter 6 is an infrared cut filter that is integrally attached to the image sensor 7. For this reason, the filter 6 and the image sensor 7 are omitted from FIG. 2 and FIG.

  The units 2 and 3 constitute two groups of five fixed-focus lens units, and the ultrasonic linear actuator 4 drives the first group unit 2 in order to realize autofocus. The first group unit 2 includes three optical elements 21, 22, and 23, a holding member 24 that holds the optical elements 21, 22, and 23, light shielding plates 25 and 26, and a pressing member 30 that will be described later. Configured. The second group unit 3 includes two optical elements 31 and 32 and light shielding plates 33 and 34. The optical elements 31 and 32 are held by a rear frame 51 that is a holding member.

  The optical elements 21, 22, 23; 31, 32 are made of plastic lenses, and include lens portions 211, 221, 231; 311, 321, and lens portions 211, 221, 231, 311, 321 that form an optical path. And holding portions 212, 222, 232; 312 and 322, which are held from the outer peripheral side, and are integrally molded. The light shielding plates 25, 26, 33, and 34 for blocking unnecessary light are provided between the lens portions 211, 221, 231, 311, and 321, respectively.

  The ultrasonic linear actuator 4 which is a driving mechanism of the first group unit 2 which is a moving lens group is an actuator suitable for miniaturization, which was previously proposed by the applicant in Japanese Patent Laid-Open No. 2001-268951, for example. It is called a SIDM (Smooth Impact Drive Mechanism (registered trademark)) actuator. In this ultrasonic linear actuator 4, a rod 42 is connected to one end of a piezoelectric element 41 that expands and contracts in the axial direction, a weight 43 is connected to the other end, and the rod 42 reciprocates by the expansion and contraction of the piezoelectric element 41. Since the holding member 24 of the group unit 2 is engaged with the rod 42 with a predetermined frictional force, the first group unit 2 is moved in the optical axis direction.

  Specifically, the drive mechanism of the ultrasonic linear actuator 4 is that when a rectangular wave is applied to the piezoelectric element 41, the displacement of the piezoelectric element 41 appears in a triangular wave shape, and the duty of the rectangular wave is changed to increase the amplitude. This is based on the fact that triangular waves with different slopes are generated when descending. For example, when the rod 42 is slowly extended, the first group unit 2 that is frictionally engaged with the rod 42 is also moved. When the rod 42 is instantaneously reduced to exceed the predetermined friction force, the first group unit 2 is moved. It is possible to move the first group unit 2 in the axial direction of the rod by repeatedly performing that 2 is left in the extended position.

  The weight 43 is for generating a displacement due to expansion and contraction of the piezoelectric element 41 only on the rod 42 side, and when the other end of the piezoelectric element 41 is attached to the housing 5 and the like can be exhibited. May be omitted. The engagement of the holding member 24 with the rod 42 is performed using a frictional force generated as described later, but a magnetic force may be used.

  The piezoelectric element 41 of the ultrasonic actuator 4 is formed by laminating a plurality of piezoelectric layers and drawing out electrodes of each piezoelectric layer in common on a pair of side surfaces. The side electrodes 411 and 412 are connected to external connection terminals 46 and 47 via individual lead wires 44 and 45, respectively. The distal ends 461 and 471 of the external connection terminals 46 and 47 are soldered to a printed circuit board on the terminal side of the mobile phone, or are fitted into a connector mounted on the printed circuit board. The mounting of the ultrasonic actuator 4 and the wiring routing will be described in detail later.

  The casing 5 is formed of a rear frame 51 that is a resin-molded product, a front frame 52 that is combined with the frame 51 to form a box, and is formed by sheet metal processing. A front cover 53 is provided. The structure of the housing 5 will also be described in detail later.

  FIG. 4 is an enlarged view showing a cross section taken along section line IV-IV in FIG. FIG. 4 is a diagram for explaining in detail the joint structure between the optical elements 21, 22 and 23 in the first group unit 2 and the joint structure of the lens block formed by the joint to the holding member 24. In assembling the first group unit 2, first, the light shielding plate 26 is sandwiched between the optical elements 22, 23, the optical elements 22, 23 are attached to each other, and the light shielding plate 25 is interposed between the optical elements 21, 22. Is sandwiched, and after the optical element 21 is aligned, the optical elements 21 and 22 are attached to each other by a body to complete the lens block.

  Next, the lens block is fitted into the cylindrical holding member 24 from the optical element 21 side, and the front end surface 212a of the holding portion 212 is formed in an inward flange shape on the front end (object) side of the holding member 24. In the state where the outer peripheral surface 222a of the holding portion 222 of the optical element 22 is in contact with the inner peripheral surface 242a of the cylindrical portion 242 of the holding member 24. The outer peripheral surface 232a of the holding portion 232 of the optical element 23 on the rear (image) side and the end surface 242b of the cylindrical portion 242 are bonded and fixed by the adhesive 27 to complete the first group unit 2.

  It should be noted that in the first group unit 2 in which a plurality of optical elements 21, 22, and 23 are bonded to each other in this way, the holding portions 212, 222, and 232 are adjacent to each other. , 22, 23, contact surfaces 212 b; 222 b, 222 c; 232 c that define the distance between the lens portions 211, 221, 231, and adhesive application surfaces 212 d; 222 d, facing each other with predetermined distances d 1, d 2. 222e; 232e, and in order to prevent penetration of the adhesive 28 from the adhesive application surface 212d; 222d, 222e; 232e to the abutment surface 212b; 222b, 222c; Grooves 212f; 222f, 222g; 232g extending in the direction are formed. The contact surfaces 212b, 222b; 222c, 232c facing each other are formed in an annular shape with radial widths W11, W12, respectively, and the adhesive application surfaces 212d, 222d; 222e, 232e are radial widths. Are formed annularly at W21 and W22, respectively. The distances d1 and d2 are set to 0.005 to 0.01 mm, for example, and the widths W21 and W22 are set to 0.4 mm, for example.

  With this configuration, the adhesive 28 is applied to at least one of the adhesive application surfaces 212d, 222d; 222e; 232e facing each other in each of the holding portions 212, 222, 232, and the adjacent optical element 21 is applied. , 22, 23 are pressed against each other and the adhesive 28 is cured by heating, ultraviolet irradiation, or the like, so that the optical elements 21, 22, 23 can be easily and firmly joined to each other by mounting. Further, during the pressing, as shown by reference numeral 28a, the surplus adhesive flows into the groove portions 212f; 222f, 222g; 232g, thereby to the contact surfaces 212b; 222b, 222c; 232c. The adhesive 28 can be prevented from sticking out, and the optical performance can be ensured without adding an extra error to the distance between the lens portions 21, 22, and 23.

  In the holding portions 212, 222, 232, the holding surfaces 212b; 222b, 222c; 232c are arranged on the outer peripheral side, and the adhesive application surfaces 212d; 222d, 222e; The distance between the lens parts 211, 221, 231 is defined on the outer peripheral side of the parts 212, 222, 232, and the distance between the contact surfaces 212b, 222b; 222c, 232c rather than the inner peripheral side. (Span) is expanded, and the error (including inclination) and eccentricity of the gap due to manufacturing errors can be further reduced, and the excess adhesive 28a from the outer peripheral side of the holding portions 212, 222, 232 can be reduced. Protrusion can be prevented, and the assembled optical elements 21, 22, and 23 can be accurately assembled to the holding member 24.

  Furthermore, in the holding portions 212 and 222, groove portions 212h and 222h are also formed on the lens portions 211, 221, and 231 side of the adhesive application surfaces 212d, 222d; 222e; Thus, by forming the groove portions 212h and 222h also in the vicinity of the innermost periphery of the holding portions 212 and 222, the excess adhesive indicated by reference numeral 28a also protrudes toward the lens portions 211, 211, and 231 side. Therefore, optical performance can be ensured.

  In addition, a protrusion or protrusion 222k that loosely fits into the groove 212h is formed in the holding part 222 that faces the groove 212h that is formed in an annular shape in the holding part 212, and the protrusion or protrusion 222k The inner diameter of the groove 212h is larger than the outer diameter by a predetermined dimension. That is, when the optical elements 21 and 22 are mounted together, the groove portion 212h into which the excess adhesive indicated by reference numeral 28a flows is formed in one of them in a large annular shape, and the other is a small protrusion or protrusion. When forming 222k and bonding them together, the protrusion or protrusion 222k prevents the excess adhesive 28a from overflowing from the groove 212h, and the protrusion or protrusion 222k fits into the groove 212h. Yes. The relationship between the protrusions or protrusions 222k and the groove part 212h is that the inner diameter of the groove part 212h is larger than the outer diameter of the protrusions or protrusions 222k by a predetermined dimension. Deviations in the direction orthogonal to the optical axis are allowed between 22.

  Therefore, by adjusting the deviation, the optical element 21 can be aligned as described in detail later, and after the alignment, the adhesive 28 is cured to fix the optical elements 21 and 22 together. This makes it possible to eliminate the alignment ball frame that has been used conventionally.

  Furthermore, the optical elements 21, 22, and 23 are made of plastic lenses, and the holding portions 212, 222, and 232 are formed from holding pieces that extend from at least a part of the outer periphery of the lens portions 211, 221, and 231. They are formed as a single piece, and the holding portions 212, 222, and 232 are barreled together as described above. Here, when the lens portion is made of a glass lens, the holding frame serving as the holding portion is often provided as a separate body, and this holding frame is bonded and fixed as described above. By attaching the optical elements 21, 22, and 23 to each other as described above, it is not necessary to use a separate component holding frame for bonding between the optical elements 21, 22, and 23.

  On the other hand, in the first group unit 2 as described above, it should be noted that a plurality of optical elements 21, 22, and 23 are held by the cylindrical holding member 24 to form a lens unit in advance. , 22 and 23 are bonded and fixed to form the lens block, so that the optical element 22 fitted to the holding member 24 and the optical element 23 to be bonded can be separated. Utilizing this, in addition to the adhesive reservoir portion 27b having a normal thickness of the adhesive 27, between the optical element 23 to be bonded and the holding member 24, a minute gap d3 is formed between them. An adhesive layer 27a is provided.

  Specifically, when the optical elements 21, 22, and 23 made of the plastic lens are fitted into the holding member 24, at least one optical element, preferably the optical element 22 made of a material having a small linear expansion coefficient, is held in a cylindrical shape. The member 24 is fitted to the inner peripheral surface 242 a, that is, engaged in the radial direction of the holding member 24. On the other hand, the remaining optical elements 21 and 23 are bonded to the optical element 22 in advance to form the lens block, whereby positioning such as optical axis alignment and tilt adjustment is performed. Then, at least some of the remaining optical elements 21 and 23, preferably the optical element 23 on the rear (image) side that is finally fitted into the cylindrical holding member 24, includes an inner portion of the holding member 24. An outer peripheral surface 232a is formed in parallel with the circumferential surface 242a with a predetermined minute interval d3, and an adhesive 27 is filled between the inner peripheral surface 242a and the outer peripheral surface 232a, so that the lens block is Adhere to the holding member 24.

  Thus, the adhesive 27 filled between the optical element 23 and the holding member 24 forms an adhesive layer 27a between the inner peripheral surface 242a and the outer peripheral surface 232a, and the cylindrical portion 242 Between the end surface 242b and the outer peripheral surface 232a is an adhesive reservoir 27b. With such a configuration, the inner members of the holding members 24 that are parallel to each other can be formed without using a separate member such as a lens presser and without generating an extra space in the depth direction like the lens presser or the caulking. The adhesive layer 27a formed at the minute distance d3 between the peripheral surface 242a and the outer peripheral surface 232a of the optical element 23 can improve the adhesive strength by utilizing the holding force in the shear direction. As a result, it is possible to reduce the size and height while improving the reliability against vibration and impact.

  The minute distance d3 is preferably 0.1 mm or less. If the thickness is 0.1 mm or less, the adhesive layer 27a can generate a large shearing direction holding force, that is, a large shearing force is required to release the adhesive layer 27a. This is because the lens block can be hardly detached from the holding member 24.

  Further, when the three optical elements 21, 22, and 23 are joined to each other as described above, the holding portions 222 and 232 of the intermediate optical element 22 and the rear (image) side optical element 23 are fitted to each other. In addition, there are provided steps 222i and 232i in the optical axis direction that prevent displacement in the direction perpendicular to the optical axis of each other. Accordingly, by simply bonding the adhesive application surfaces 222e and 232e to each other, displacement in the direction perpendicular to the optical axis (diameter) between the holding portions 222 and 232 is prevented, and alignment can be performed.

  On the other hand, in the holding portions 222 and 212 between the intermediate optical element 22 and the front (object) optical element 21, the contact surfaces 222b and 212b and the adhesive application surfaces 222d and 212d are perpendicular to each other's optical axis. A smooth surface that allows directional displacement is formed, and the optical elements 22 and 21 can be aligned within a range allowed by the groove 212h and the protrusions or protrusions 222k. Therefore, after the optical elements 22 and 23 are bonded, when the optical element 21 is bonded, an ultraviolet curable adhesive is applied as the adhesive 28 to the adhesive application surfaces 222d and 212d, and alignment is performed. Then, the adhesive 28 is solidified by irradiation with ultraviolet rays.

  At the time of bonding of the optical element 21 to the optical elements 22 and 23, the optical elements 22 and 23 are temporarily assembled together with members corresponding to the optical elements 24 and 25 and the image pickup element 7 in one jig. Alignment is performed by adjusting the positions of the two jigs while being attached to the other jig and confirming the imaging output of the imaging device 7 (while viewing the optical performance). Specifically, a chart placed on the object side is photographed by the image sensor 7 through the temporary optical elements 21 to 25 described above, and the optical element 21 (the other side) is selected according to the state of the photographed image (one blur etc.). ) Is moved in a direction perpendicular to the optical axis. In this way, the optical elements 21, 22, and 23 can be integrated while adjusting so as to obtain predetermined optical performance.

  Of the optical elements 21, 22, and 23 integrated as the lens block, the intermediate optical element 22 is fitted to the inner peripheral surface 242a of the cylindrical holding member 24 as described above, and the rear (image) By adhering the outer peripheral surface 232a of the optical element 23 on the side to the inner peripheral surface 242a of the holding member 24, the reliability against vibration and impact can be improved. In the configuration of the three optical elements 21, 22, and 23 as described above, conventionally, when the alignment is performed, the optical element 21 is adjusted with respect to a ball frame that integrally holds the optical elements 22 and 23. The ball frame is held by the core ball frame, and after the position adjustment, the ball frames are bonded to each other. However, in the present embodiment, the optical element 21 is bonded to the optical element 22 by the body as described above. The alignment ball frame can be reduced, and the size and height can be reduced.

  In the above-described example, the retaining plate 241, which is a retainer, is formed on the front end (object) side of the holding member 24, and the optical elements 21, 22, and 23 integrated as the lens block are located behind the holding member 24 (image). Although the presser plate 241 is provided on the rear end (image) side and the optical elements 21, 22, and 23 are fitted from the front (object side), the optical element 21 on the front (object) side is inserted. Is bonded to the holding member 24.

  Further, although the number of optical elements 21, 22, and 23 constituting the first unit 2 is three, it may be two or four or more. When two sheets are fitted from the rear (image side) of the holding member 24, as shown in FIG. 5, the optical element 21 ′ on the front (object) side is fitted to the holding member 24 ′, and the rear (image side) is fitted. The optical element 23 ′ is bonded to the holding member 24 ′. When there are four or more optical elements, it is preferable that at least a substantially intermediate optical element is fitted to the holding member 24.

  Furthermore, in the above-described embodiment, the optical elements 21, 22, and 23 are configured to include the lens portions 211, 221, and 231 and the holding portions 212, 222, and 232 formed to extend from the outer peripheral edge portions thereof. In this configuration, the groove portions 212f; 222f, 222g; and the contact surfaces 212b; 222b, 222c; 232c and the adhesive application surfaces 212d; 222d, 222e; 232e of the holding portions 212, 222, 232; Although an example in which 232g is formed is shown, as shown in FIG. 6, it may be used when the single lens 20 is bonded to a holding member 29 such as a lens barrel or a lens frame.

  That is, in the lens unit 2 ′ formed by joining the single lens 20 having the lens portion 20a and the outer edge portion 20b extending to the outer peripheral side of the lens portion 20a and the holding member 29 holding the lens 20a, The holding member 29 is opposed to the abutting surface 29a that abuts on the outer edge portion 20b and performs positioning in the optical axis direction, and is opposed to the outer edge portion 20b with a predetermined interval d4, and an adhesive 28 'should be applied thereto. A groove 29c extending in the circumferential direction is formed at the boundary between the contact surface 29a and the adhesive application surface 29b. Even with this configuration, it is possible to prevent the adhesive 28 ′ from protruding from the adhesive application surface 29 b to the contact surface 29 a side, and it is unnecessary to attach the single lens 20 to the holding member 29. Optical performance can be ensured without additional errors.

  On the other hand, in the second group unit 3, the optical element 32, the light shielding plate 34, and the optical element 31 are sequentially fitted in the fitting holes 511 formed in the rear frame 51, and are bonded and fixed by the adhesive 35. What should be noted here is the fixed lens group, and in the second group unit 3 including the imaging element 7 on the rear (image) side, the holding member 322 of the optical element 32 on the rear (image) side has its holding member. That is, a step 324 is formed in a part of the contact surface 323 with the rear frame 51 in the circumferential direction, and a notch 326 continuous with the step 324 is formed in the outer peripheral surface 325. Correspondingly, a notch 316 is also formed on the outer peripheral surface 315 of the holding portion 312 of the optical element 31 on the front (object) side, and the second group unit is only passed through the step 324 and the notches 326 and 316. 3 and the image sensor 7 communicate with the outside.

  FIG. 7 is an enlarged cross-sectional view of a portion indicated by reference numeral α in FIG. FIG. 8A is a front view of the optical element 32, and FIG. 8B is an enlarged sectional view showing the vicinity of the peripheral edge of the holding portion 322. As shown in FIG. The fitting hole 511 of the rear frame 51 is provided with a presser plate 511 a formed in an inward flange shape on the rear end (image) side, and the holding portion 322 of the optical element 32 is provided. The contact surface 323 is held. Accordingly, the step 324 formed in a part of the contact surface 323 forms a gap d5 between the pressing plate 511a.

  Further, after the optical elements 32 and 31 made of plastic lenses are molded by injection molding, the gate position is D-cut in the deburring process. The notches 326 and 316 are formed by this D cut, and the range due to the D cut is indicated by a section d6 in FIG. 8A, and the range of the diameter variation due to the D cut is shown in FIG. 7 and FIG. 8B. Then, it shades and shows. In FIG. 8, the step 324 is highlighted. Then, after assembling the optical elements 32 and 31 to the rear frame 51, as shown in FIG. 9, the adhesive 35 is not applied only in the section D6 of the D cut, and the gap 317 due to the notches 326 and 316 is formed. Open to the outside. When caulking or welding is used in place of the adhesive 35, it is only necessary to prevent such fixing (blocking) only in the section d6. The section d6 is, for example, about 0.3 to 0.8 mm.

  Here, in a small imaging device in which lenses cannot be replaced, the periphery of the moving lens group for autofocus and zooming is open to the outside air (communication with the outside) so as not to obstruct the movement of the moving lens group. However, the space between the image pickup elements provided on the image (rear) side from the fixed lens group that does not move is usually a sealed space, or the temperature or pressure of In order to cope with the expansion / contraction of the air in the space due to the change, a filter or the like is provided in the passage to the space, and the inflow of the outside air is restricted.

  In contrast, in the present embodiment, the structure of the optical elements 32 and 31 in the second group unit, which is an existing component, and the rear frame 51, which is the holding member, is devised as described above (review of clearance). 7), an air passage as shown by reference symbol F in FIG. 7 is formed to cope with the expansion / contraction of the air in the space 8 due to the change in the temperature or the atmospheric pressure. That is, the air passage is formed by communicating the step 324 and the notch 326 in the holding portion 322 of the optical element 32 and the notch 316 in the holding portion 312 of the optical element 31. And the width, height, and diameter of the air passage are formed narrower than the diameter of the dust. Specifically, the distance d5 between the contact surface 323 and the presser plate 511a due to the step 324 is set to 0.02 mm or less, which is the minimum size of dust that causes image smearing.

  By configuring in this way, the step 324 and the notches 326, 316 portions realize a labyrinth structure that dust cannot enter, and the structure is an existing component part without causing an increase in the number of parts, In addition, no separate parts are required, and this can be realized easily and at low cost.

  Further, by using the D cut formed at the gate position at the time of injection molding of the optical elements 32, 31 in the notches 326, 316, the D cut is formed in a process such as deburring at the time of molding. And increase in the number of processes can be eliminated.

  It should be noted that at least a part of the step 324 and the notches 326 and 316 forming the air passage may be formed narrower than the minimum size of the dust. Further, the step 324 and the notch 326 provided in the same optical element 32 need to communicate with each other at the same position in the circumferential direction, that is, as described above. 316 does not necessarily need to coincide with the circumferential position. However, if they match, an air escape passage can be surely formed.

  Furthermore, the step 324 and the notches 326 and 316 may be formed on any of the optical elements 32 and 31 and the rear frame 51. However, if the step 324 and the notches 326 and 316 are formed on the optical elements 32 and 31 side as described above, they are retained. The core processing of the rear frame 51, which is a member, is facilitated, and when formed on the rear frame 51 side, the core processing of the optical elements 32 and 31 is facilitated, and the accuracy of each component can be improved.

  Next, the configuration of the housing 5 will be described. Referring to FIGS. 2 and 3, among the members constituting the housing 5, the front cover 53 is a sheet metal processed product provided on the electromagnetic shield and appearance (design), and the frames 51 and 52 are assembled. After that, the latching claws 531a provided on the side wall 531 are covered with the latching recesses 512a formed on the side wall 512 of the rear frame 51 so as to be fixed to the rear frame 51. Just do. Therefore, the structure of the frames 51 and 52 will be specifically described below.

  As described above, the frames 51 and 52 are combined with each other to form a box, and at least the first group unit 2 and the second group unit 3 and the ultrasonic linear actuator 4 are accommodated therein. It should be noted that the frames 51 and 52 are formed of a resin molded product having a shape divided into two before and after the box is in the optical axis direction, and the side walls 512 and 521 of the box have through holes. This means that the box body is formed in an airtight manner (the locking recess 512a is not a through hole but a recess with a closed bottom).

  FIG. 10 is a perspective view showing a state in which only the frames 51 and 52 are combined except for the first group unit 2 and the second group unit 3 and the ultrasonic linear actuator 4. 11 is a view of the rear frame 51, (a) and (b) are perspective views as viewed from the front surface (object) side, (c) is a perspective view as viewed from the rear surface (image) side, and (d). FIG. 3 is a front view seen from the front (object) side. Similarly, FIG. 12 is a view of the front frame 52, (a) is a perspective view seen from the front (object) side, (b) and (c) are perspective views seen from the rear (image) side, (d) ) Is a front view seen from the rear (image) side.

  10 and 12 together with FIGS. 1 and 2, the rear frame 51 is generally configured such that the side wall 512 is erected from the outer peripheral side of the rectangular base 513, and the inner peripheral A holding cylinder 514 is erected on the side. The inner peripheral side of the holding cylinder 514 serves as the fitting hole 511 and holds the second group unit 3. In the side wall 512, all four side walls have locking recesses 512a into which the locking claws 531a of the front cover 53 are fitted on the rear end (image) side, and a pair of side walls parallel to each other. Are formed with locking projections 512b that fit into locking holes 521a formed in the side wall 521 of the front frame 52. As a result, the front frame 52 and the front cover 53 can be attached to the rear frame 51 simply by fitting without performing a special fixing operation.

  In addition, a plurality of positioning bosses 515 are appropriately distributed on the rear frame 51. By fitting into the corresponding positioning holes 525 on the front frame 52 side, the frames 51, 52 Deviation in the direction orthogonal to the optical axis is prevented.

  Furthermore, a storage recess 516 for storing the ultrasonic linear actuator 4 is formed in one corner of the rear frame 51, and the first group unit 2 is mounted in a diagonal corner. A pair of guide walls 517 for guiding is formed. Furthermore, mounting recesses 518 and 519 corresponding to the external connection terminals 46 and 47 are formed on the side wall away from the storage recess 516.

  In the front frame 52, the side wall 521 is erected from the outer peripheral side of the rectangular front plate 522, and an opening 523 is formed on the inner peripheral side so that the first group unit 2 faces the outside. In addition, a fitting hole 526 into which the tip of the rod 42 of the ultrasonic linear actuator 4 is fitted is formed at one corner of the front frame 52, and the corner 1 on the diagonal line has the 1 A pair of guide walls 527 for guiding the group unit 2 is formed.

  In assembling these frames 51 and 52, first, as described above, the optical element 32, the light shielding plate 34, and the optical element 31 are sequentially fitted in the fitting holes 511 of the rear frame 52 and bonded and fixed by the adhesive 35. Thus, the second group unit 3 is completed. Next, the ultrasonic linear actuator 4 is incorporated into the housing recess 516 of the rear frame 51, the external connection terminals 46 and 47 of the ultrasonic linear actuator 4 are fitted into the mounting recesses 518 and 519, and the pair of lead wires 44 and 45 is drawn around the second group unit 3 and is held down by the light shielding plate 33. Subsequently, after the first group unit 2 assembled as described above is engaged with the rod 42 of the ultrasonic linear actuator 4, the front end portion thereof is fitted into the fitting hole 526, and the two frames 51. , 52 are combined, and the locking projections 512b are fitted into the locking holes 521a, so that the frames 51, 52 are fixed to each other.

  However, in this state, the ultrasonic linear actuator 4 is only fixed at one point of the tip of the rod 42, and the piezoelectric element 41 side can be displaced. This is because the attachment angle (tilt angle) of the ultrasonic linear actuator 4 with respect to the frames 51 and 52 can be adjusted. After adjustment, the back surface 43a of the weight 43 is bonded to the base 513 of the rear frame 51. Then, the piezoelectric element 41 is fixed. Therefore, the base 513 is formed with an adjustment hole 516 a that continues to the storage recess 516. The adjustment hole 516a is formed to have a smaller diameter than the weight 43.

  FIG. 13 is a cross-sectional view showing the structure of the jig 9 for adjusting the attachment angle (tilt angle) of the ultrasonic linear actuator 4 and performing adhesion. The jig 9 is generally configured to include a first jig 91, a second jig 92, and an adhesive filling means 93. The first jig 91 serves as a mounting reference plane for the image sensor 7 in the rear frame 51 to which the second group unit 3 is mounted, and is therefore parallel to the element surface of the image sensor 7 and the second group unit 3. And has a contact surface 911 that is in contact with a rear surface 513a of the base 513 formed perpendicular to the optical axis, and grips the rear frame 51. The second jig 92 serves as a reference surface of the first group unit 2 and abuts against the front surface 241b of the presser plate 241 formed perpendicular to the optical axis of the first group unit 2, thereby the first jig. It has a contact surface 921 parallel to the contact surface 911 on the tool 91 side.

  Therefore, the second jig 92 adsorbs the first group unit 2 so that the angle of the optical axis of the first group unit 2 with respect to the element surface of the image sensor 7 can be adjusted vertically. The adhesive filling means 93 has a discharge port 931 in the vicinity of the adjustment hole 516a, and after the optical axis adjustment of the first unit 2 is performed as described above, the rear end surface of the weight 43 from the discharge port 931. When the ultraviolet curable adhesive 48 is discharged toward 43 a and irradiated with ultraviolet rays, the weight 43 is fixed to the base 513.

  FIG. 1 shows a state in which the front cover 53 is fitted after being assembled from the jig 9 after being assembled in this manner. By using such a jig 9, it is possible to easily adjust the inclination of the first group unit 2, which is a moving lens group, and adhere and fix the ultrasonic linear actuator 4 to the rear frame 51.

  Here, in the jig 92, the positioning pin 922 that abuts the tip end portion 42a of the rod 42 of the ultrasonic linear actuator 4 and defines the mounting height of the ultrasonic linear actuator 4 is the shape of the abutting portion 922a. Is formed in a spherical shape. Therefore, the abutting portion 922a comes into contact with the center of the tip end portion 42a of the rod 42, and the tilt adjustment can be stabilized.

  In addition, after assembling the imaging device 7 to the rear frame 51, while monitoring the captured image, the simple operation of moving the back surface 43a of the weight 43 from the adjustment hole 516a to the place where the image quality is the best, After adjusting the inclination of the ultrasonic linear actuator 4 and further adjusting the position of the image sensor 7 with respect to the second group unit 3, the ultrasonic linear actuator 4 may be fixed to the frame. In that case, with the lens configuration of a plurality of groups, it is possible to cancel the performance degradation factors other than the first group unit 2 which is the moving lens group, and it is possible to achieve the performance as the total imaging apparatus.

  As described above, in the imaging apparatus 1 in which the first group unit 2 is moved in the optical axis direction using the ultrasonic linear actuator 4 for autofocusing, the frame that forms the generally outer shape of the imaging apparatus 1 51, 52 are formed in a shape in which the box is divided into two in the front and rear directions in the optical axis direction, and the front end plate 522 of the front frame 52 is used to connect the tip of the rod 42 of the ultrasonic linear actuator 4 to the base 513 of the rear frame 51 By holding the piezoelectric element 42 via the weight 43, the side walls 512 and 521 of the frames 51 and 52 can be formed in an airtight shape, that is, without a through hole. As a result, intrusion of dust can be prevented, the rigidity of the frames 51 and 52 such as the push-proof strength from the front surface is increased, and the ultrasonic linear actuator 4 is prevented from being destroyed by the pressure applied to the frames 51 and 52. You can also.

  Further, a front end portion 42a of the rod 42 of the ultrasonic linear actuator 4 is fitted into the front plate 522 of the front frame 52, and the front end portion is supported so that the ultrasonic linear actuator 4 can tilt (tilt) within a predetermined range. The base 513 of the rear frame 51 is provided with an adjustment hole 516a that faces the back surface 43a of the weight 43 and is narrower than the back surface 43a. Since the position of the weight 43 is adjusted with respect to the adjustment hole 516a so that the angle of the imaging element 7 with respect to the element surface is vertical, the weight 43 is fixed by filling the adjustment hole 516a with the adhesive 48. The angle at which the ultrasonic linear actuator 4 is attached to the frames 51 and 52 can be adjusted, and the inclination accuracy of the first group unit 2 that is the moving lens group depends on the component accuracy. It can be improved without. Further, the fitting hole 526 is closed by the tip 42a of the rod 42, and the adjustment hole 516a is closed by the back surface 43a of the weight 43 and the adhesive 48, so that dust does not enter, and the fitting hole 526 Therefore, the molded product (front frame 52) is not required to be thick, and the height can be reduced.

  In addition, since the rod 42 of the ultrasonic linear actuator 4 is only supported by the front plate 522, the length of the rod 42 is approximately that of the portion supported by the front frame 52. The length can be reduced to the length obtained by adding the moving length of the first group unit 2, that is, only two shaft support portions are required for the shaft fitting length. The height of the apparatus can be reduced, and the height can be reduced. Furthermore, even if the adjustment hole 516a is formed so as to adjust the inclination of the first group unit 2, the adjustment hole 516a is filled with the adhesive 48 and closed with the weight 43, so that intrusion of dust Can also prevent.

  The rod 42 of the ultrasonic linear actuator 4 may be supported by the base 513 of the rear frame 51, and the weight 43 may be supported by the front plate 522 of the front frame 52.

  Here, FIG. 14 shows a state when the rear frame 51 is molded (for convenience, the top and bottom are reversed). The frames 51 and 52 are structurally not formed with a member protruding in the front-rear (optical axis) direction, that is, in a direction orthogonal to the mold drawing direction. Accordingly, as a mold for molding the frame 51, a fixed core 94 and a movable core 95 that can move close to and away from the fixed core 94 in the pulling direction are provided, and movable in a direction orthogonal to the pulling direction. The slide core 96 is provided, and the die is punched into arrows 94a, 95a, and 96a, respectively. At this time, when forming the locking recess 512a and the locking projection 512b, as shown in FIG. 14, the movable core 95 is formed as it is by the arrow 95a, that is, the front and rear. It can be punched in the (optical axis) direction.

  When the side surfaces of the frames 51 and 52 are formed by the left and right slide cores 961 and 962 as shown in FIG. 15, the portions that become the locking recesses 512a and the locking projections 512b, A tapered surface is formed along the drawing direction 96a as indicated by reference numeral 512a1. An angle β between the tapered surface 512a1 and the side surfaces of the frames 51 and 52 is within 45 °. Accordingly, the left and right slide cores 961 and 962 can form irregularities on the side surfaces of the frames 51 and 52 (in the front view of the rear frame 51 shown in FIG. 11D, the external connection terminals 46 and 47). In the mounting recesses 518 and 519 corresponding to the above.

  With this configuration, it is easy to remove the mold, and there is no core in the mold configuration, so that a box body with no through-holes can be formed on the side walls 512 and 521 as described above, and dust can enter. Can be prevented, and the rigidity of the frames 51 and 52 can be increased.

  FIG. 16 shows an example in which a plurality (four in the example of FIG. 16) of frames 51 are formed using the slide cores 961 and 962 as shown in FIG. In this way, the unevenness on the side surfaces of the frames 51 and 52 can be formed only by the left and right slide cores 961 and 962, so that the molded product (frames 51 and 52) can be formed close to each other, and the number of parts to be taken increases. , Can reduce the cost.

  As shown in FIG. 17A, when the frame 52 ′ and the front frame 53 (not shown) are fixed to the frame 51 ′ by bonding, the side surfaces of the frames 51 ′ and 52 ′ are not uneven, It is possible to mold only with the cores 97 and 98 that are punched back and forth as shown in 17 (b), and the number of removal can be increased.

  On the other hand, FIG. 18 shows a state when the front frame 52 is molded. The front frame 52 is formed with a fitting hole 526 for the rod 42 in the front plate 522. The fitting hole 526 is formed by the movable core 100, and a taper 526a is formed on the outer periphery of the fitting hole 526 on the side to be the back surface of the front plate 522. Therefore, when the mold is clamped with the fixed core 99 and molded, the touch burr (whisker) is formed on the outer surface side of the frame 52 even if it is formed.

  Therefore, as shown in FIG. 19, when the rod 42 is fitted into the fitting hole 526, there is no influence of burrs and the engagement of the moving member 24 without entering the airtight frames 51 and 52. It does not bite into the joint portion 243. Thereby, the ultrasonic linear actuator 4 can perform a smooth operation. Further, the rod 42 only needs to be fitted into the fitting hole 526 at one place, and the taper 526a is formed at the inlet, so that the rod 42 can be easily assembled.

  20 and 21 are diagrams for explaining the routing of the lead wires 44 and 45, FIG. 20 is a cross-sectional view of the imaging device 1, and FIG. 21 is a cross-sectional line XXI- of FIG. It is sectional drawing seen from XXI. 20 and 21, the lead wires 44 and 45 are soldered. In the configuration of the frames 51 and 52 as described above, it should be noted that in this embodiment, the lead wires 44 and 45 are routed to the ultrasonic linear actuator 4 and the external connection terminals 46 and 47 are attached. It is to devise.

  Specifically, first, the electrodes 411 and 412 of the piezoelectric element 41 of the ultrasonic actuator 4 have one ends 441 and 451 of individual lead wires 44 and 45 that are easily deformed and are routed through the frames 51 and 52. Are soldered as indicated by reference numerals 481 and 491, respectively. The other ends 442 and 452 of the lead wires 44 and 45 are soldered to the external connection terminals 46 and 47 as indicated by reference numerals 482 and 492, respectively.

  Here, the external connection terminals 46 and 47 are generally formed in a J shape by sheet metal, as shown in FIG. 3 and FIG. 20, and the lead wires 44 and 472 are connected to the J-shaped short pieces 462 and 472, respectively. The other ends 442 and 452 of 45 are soldered. Further, the tips 461 and 471 of the J-shaped long pieces 463 and 473 are conductively connected to an external substrate or the like, or fitted into a connector or the like.

  On the other hand, as described above, the frames 51 and 52 that accommodate at least the first group unit 2 and the second group unit 3 and the ultrasonic linear actuator 4 are formed by dividing the box into two, and the external connection terminals 46, 47, the bent portions 464 and 474 are sandwiched between the butted surfaces 519 and 529 of the two divided frames 51 and 52, and the side wall 512 of the frame 51 is connected to the sheet metal of the external connection terminals 46 and 47. Is fixed by being sandwiched between the inner peripheral surfaces 465 and 475 of the J-shape.

  By configuring in this way, by using inexpensive parts with high versatility individually for the configuration for driving the ultrasonic linear actuator 4, such as the external connection terminals 46, 47 and the lead wires 44, 45, Cost reduction can be achieved compared to insert molding. Further, the thickness of the side wall 512 of the frame 51 may be minimal, and the connection method of the lead wires 44 and 45 to the electrodes 411 and 412 of the ultrasonic linear actuator 4 is simply soldering, and the reference numerals 481 and 491 are used. The projected area of the soldered portion shown can be reduced, and downsizing can be achieved. Furthermore, in realizing the free routing of the lead wires 44 and 45, by using the metal external connection terminals 46 and 47, the abutment surfaces 520 and 530 of the frames 51 and 52 can be compared with the flexible substrate. It is easy to obtain accuracy when sandwiched, so that the airtightness can be maintained and the invasion of dust becomes strong.

  Furthermore, using the ultrasonic linear actuator 4 as described above as a driving mechanism for the first group unit 2 is not only suitable for downsizing, but also the driving mechanism applies a rectangular wave to the piezoelectric element 41 as described above. As just indicated, the number of terminals (electrodes) may be two as indicated by reference numerals 411 and 412. Therefore, even if the lead wires 44 and 45 are used for the individual external connection terminals 46 and 47 as described above, the number of terminals and the number of wires are minimized, and it is particularly suitable for the above-described configuration using these. .

  In addition, the lens units 2 and 3 are arranged in the center of the rectangular frames 51 and 52, and the ultrasonic linear actuator 4 is installed at the corners of the frames 51 and 52. By providing the terminals 46 and 47 on the side wall 5121 that is not adjacent to the ultrasonic linear actuator 4 out of the four side walls 512, the positional relationship between the external connection terminals 46 and 47 and the ultrasonic linear actuator 4 can be improved. The imaging apparatus 1 can be disposed so as to be the farthest in the projection plane. As a result, when the ultrasonic linear actuator 4 is fixed, the influence of the stiffness of the lead wires 44 and 45 is minimized, and the optical performance is easily secured.

  Further, as described above, it can be driven by the two electrodes 411 and 412, and the ultrasonic linear actuator 4 formed by disposing the electrodes 411 and 412 on the opposing surface of the piezoelectric element 41 is used for the frames 51 and 52. 21 and 3, the two lead wires 44 and 45 are routed in opposite directions from the ultrasonic linear actuator 4 to correspond to the external connection terminals. Taking advantage of the fact that the lead wires 46 and 47 are reached, bare wires without insulating clothing are used for the lead wires 44 and 45. Accordingly, the process of removing the clothes in the soldering process can be omitted, the assembly can be simplified, the workability can be improved, and the lead wire can be removed when the ultrasonic linear actuator 4 is fixed. The stiffness of 44 and 45 is further reduced, and the optical performance is more easily secured.

  Further, by routing the lead wires 44 and 45 around the second group unit 3 that is a fixed lens group, it is not necessary to secure a dedicated space for routing the lead wires 44 and 45. Efficiency can be improved and miniaturization can be achieved. Further, since it is around the second group unit 3 which is a fixed lens group, there is no possibility of malfunction of the first group unit 2 which is a moving lens group, and the lead wires 44 and 45 themselves may be broken or broken. The reliability can be reduced and the reliability can be improved.

  Furthermore, the lead wires 44 and 45 are isolated from the space where the first group unit 3 as the moving lens group is disposed by a light shielding plate 33 for the purpose of blocking the incidence of harmful rays on the lens. Thus, contact with the lead wires 44 and 45 of the first group unit 2 can be prevented, and reliability can be improved.

  The external connection terminals 46 and 47 are J-shaped short pieces 462 and 472 to be soldered to a base material made of a material having relatively poor solder wettability such as SUS and a J-shaped long length. The tips 461 and 471 of the pieces 463 and 473 are subjected to any one of solder plating, gold plating, silver plating, nickel plating, and zinc plating to improve solder wettability. Therefore, good conductivity can be obtained in the soldered portion, and interference with other components due to undesired wraparound of the solder other than the portion to be soldered can be prevented, thereby improving reliability. Can do.

  Furthermore, the external connection terminals 46 and 47 are preferably made of a magnetic material. This makes it easy to set (adsorb) on a jig for soldering and improve workability. In this embodiment, austenitic stainless steel (SUS304) is used for the external connection terminals 46 and 47. Austenitic stainless steel is generally a non-magnetic material, but in this embodiment, weak magnetism generated by bending is used. The external connection terminals 46 and 47 may be made of ferritic stainless steel, which is a magnetic material. Note that, as described above, the portion to be soldered may be plated using the magnetic material as a base material.

  Next, the holding structure of the first group unit 2 will be described. FIG. 22 is a front view of the first group unit 2, and FIG. 23 is an exploded perspective view thereof. FIG. 22 also shows the rod 42 of the ultrasonic linear actuator 4. The first group unit 2 is configured by assembling the pressing member 30 to the holding member 24 that holds the optical elements 21 to 23 and the like mounted as described above, and is moved in the axial direction of the rod 42. It becomes a moving body. The pressing member 30 faces the holding member 24 which is a moving body, holds the rod 42 between the pressing member 30, and engages the holding member 24 with the rod 42 with a predetermined frictional force. It is something to be made.

  The holding member 24 is formed in a substantially rectangular shape, and the vicinity of one corner of the holding member 24 becomes an engaging portion 243 to the rod 42 of the ultrasonic linear actuator 4 arranged in the vicinity of the corner, and is diagonally Guide pieces 244 are formed in the vicinity of the corners. The guide piece 244 is fitted between a pair of guide walls 517 and 527 (see FIGS. 11 and 12) in the frames 51 and 52, whereby rotation of the holding member 24 around the rod 42 is prevented, and the rod 42 is movable in the axial direction. On the other hand, a pair of front and rear bosses 245 serving as the engaging portions of the pressing member 30 are erected on one of the corner portions adjacent to the engaging portion 243.

  On the other hand, it should be noted that the pressing member 30 is formed by forming a leaf spring member exhibiting elasticity into a substantially U shape by sheet metal processing, and the bending of the U shape which is a substantially central portion thereof. The point is an engaging portion 301 that engages with the boss 245 and can swing freely as indicated by reference numeral R. In this pressing member 30, the two sides of the dogleg are used as leaf spring members, the tip of one side 302 becomes a pressing portion 302 a that presses the rod 42 in the direction of the arrow H 1, and the tip of the other side 303 is Abutting on the abutting portion 246 of the holding member 24, the receiving portion 303a receives the reaction force in the direction of the arrow H2 generated by the pressing portion 302a pressing the rod 42.

  With this configuration, even if the pressing member 30 is supported at the substantially central portion, the elasticity can be exerted over substantially the entire length of the pressing member 30 beyond its swinging fulcrum (engaging portion 301). The length of the force point (receiving part 303a) to the action point (pressing part 302a) of the pressing member 30 can be increased.

Here, in general, the amount of deflection of the leaf spring member is proportional to the cube of the distance from the fixed point to the action point, and is proportional to the force. Therefore, as is widely used in the past, one end is fixed to the holding member. In the case of a leaf spring that presses the rod at the other end, when the distance from the fixed point to the pressing point is L and the generated force is F, the deflection amount y is
y = L ³ × F / (3EI) (I: secondary moment of section, E: Young's modulus)
It is represented by

On the other hand, in the case of the present embodiment, the distance from the fixed point (engagement portion 301) to the action point (pressing portion 302a) is also L, and the fixed point (engagement portion 301) to the reaction force support portion ( When the distance to the receiving portion 303a) is L1, the deflection amount y1 when the same force F is generated is
y1 = (L ³ + L1 ² × L) × F / (3EI)
It becomes.

Therefore, when y is compared with y1, since L1 ² is a positive value, y1 becomes larger as L1 ² × L is added. Therefore, in the case of this embodiment, when the same amount of deflection is changed in the plate wave spring member, the amount of force, that is, the frictional force (clamping force) F of the moving body with respect to the rod 42 is changed by the longer distance. Can be small. Thus, the spring sensitivity of the pressing member 30 can be reduced, variation in the frictional force (clamping force) of the ultrasonic linear actuator 4 can be suppressed, and the driving performance can be stabilized.

  Further, when the substantially central portion of the pressing member made of a leaf spring member is supported so as to be swingable, a straight line corresponding to the component layout around the holding member 24 ′, such as the pressing member 30 ′ shown in FIG. A plate spring member may be used. However, like the pressing member 30, the leaf spring portion exhibiting elasticity can be lengthened by using a substantially U-shaped leaf spring member extending over almost two sides of the holding member 24 formed in a substantially rectangular shape. The spring sensitivity can be further reduced.

  Furthermore, the engaging portion 301 of the pressing member 30 to the holding member 24 includes a pair of engaging pieces 3011 and 3012 that sandwich the plate-like holding member 24 from the thickness direction (front and rear). Engagement holes 3011a and 3012a formed in the pieces 3011 and 3012 are respectively engaged with a pair of bosses 245 erected on the front and rear sides of the holding member 24, so that the pressing member 30 is as described above. As indicated by the reference symbol R, it is supported in a swingable manner. The boss 245 is formed in a columnar shape, the engagement holes 3011a and 3012a are formed in a quadrangle into which the boss is gently fitted, and two sides V11 and V12; Each of the pressing members 30 is arranged in parallel with one side 302 on the pressing portion 302a side and another side 303 on the receiving portion 303a side.

  Therefore, when the pressing member 30 exerts an elastic force and a force in a direction in which the character is closed, that is, a direction in which the boss 245 indicated by the arrow H3 is about to come off from the engagement holes 3011a and 3012a, The cylindrical boss 245 comes into contact with two adjacent sides V11 and V21 of the rectangular engagement holes 3011a and 3012a. Thereby, even if the tolerances of the boss 245 and the engagement holes 3011a and 3012a are loose (even if they are slightly deviated or the shape is broken), the pressing member 30 can exhibit a stable elasticity.

  Further, since the pressing member 30 is attached to the holding member 24 by engaging the protrusions and recesses, a separate part for attachment is not required, the assembly can be facilitated, and the pair of engaging pieces 3011 and 3012 can hold the holding member. By sandwiching 24, a stable swinging operation can also be realized. Further, the boss 245 has a cylindrical shape on the inner side 245a of the holding member 24, whereas the outer side 245b has a guide slope, and the boss 245 extends from the boss 245 of the engagement pieces 3011 and 3012. Assembling can be easily performed while preventing the detachment. The bosses 245 may be formed on the engagement pieces 3011 and 3012, and the engagement holes 3011 a and 3012 a may be formed on the holding member 24.

  Further, in the holding member 24, in the vicinity of the ultrasonic linear actuator 4, the pressing portion 302 a of the pressing member 30 engages with the rod 42 of the ultrasonic linear actuator 4 and moves in the axial direction of the rod 42. A pair of restricting members 2471 and 2472 for restricting the operation are provided. Similarly, a pair of restricting members 2481 and 2482 are also provided on the engaging portion 301 side.

  With this configuration, in the pressing member 30 made of a leaf spring member, one side 302 of the pressing portion 302 a side from the engaging portion 301 is engaged with the rod 42 of the ultrasonic linear actuator 4. Therefore, while the holding member 24 is moved, twisting and bending may occur. On the other hand, a pair of regulating members 2471, 2472; 2481, 2482 holding the side 302 from both sides in the moving direction. By providing the above, it is possible to suppress the twisting and bending and to suppress the fluctuation of the frictional force (holding force) F of the ultrasonic linear actuator 4.

  In the above example, a pair of restricting members 2471, 2472; 2481, 2482 that are held from both sides in the moving direction are used as members that restrict the movement of the one side 302. For example, one locking hole is provided on the one side 302. A pin or the like that is gently fitted into the locking hole may be used.

  Then, the structure of the engaging part with respect to the rod 42 of the 1st group unit 2 is demonstrated. FIG. 25 is a cross-sectional view of the engaging portion, as viewed from the section line XXV-XXV in FIG. Referring to FIGS. 22 and 23, it should be noted that the rod 42 is formed in a columnar shape, and the engaging portion 243 that is a contact portion of the holding member 24 to the rod 42 is The V-shaped contact pieces 243a and 243b are configured to be provided in two sets at intervals in the axial direction of the rod 42.

  The contact pieces 243a and 243b may not be continuously formed in the V shape so as to surround the outer periphery of the rod 42, and actually contact the rod 42 as shown by the contact pieces 243c and 243d in FIG. It may be composed of four chips. Moreover, since the said pressing member faces the other side, what is necessary is just to arrange | position with the space | interval of less than 180 degrees in the circumferential direction of the rod 42. FIG. The rod 42 may be a cylinder instead of a prism, and the cross section perpendicular to the axis may be a perfect circle or an ellipse.

  Furthermore, since the V-shaped contact pieces 243a and 243b and the individual contact pieces 243c and 243d slide on the rod 42, the material thereof may be liquid crystal polymer (LCP) or polyphenylene sulfide resin (PPS). It is desirable to use an additive with increased hardness. As the additive, glass fiber, carbon fiber, titanium oxide, or potassium titanate is preferably used. The polyphenylene sulfide resin and the liquid crystal polymer have good fluidity and are suitable for precision molding, and the driving performance (speed) can be improved by adding an additive to increase the hardness.

  With this configuration, the rod 42 including the pressing member 30 is supported at three points as shown in FIG. As a result, even if the relative position between the holding member 24 and the pressing member 30 is slightly shifted, the pressing member 30 is opposite to the contact pieces 243a and 243b with respect to the rod 42, and the contact pieces 243a. , 243b, the pressing force is exerted substantially evenly. Therefore, when the engagement portion 243 is a U-groove or a V-groove continuous in the axial direction of the rod 42, the engagement at four points is more than the contact at a surface or a pair of lines. The tolerance for variation due to molding or processing of the joint portion 243 is increased, variation in the frictional force (holding force) of the holding member 24 can be suppressed, and driving performance can be stabilized.

  Preferably, the length in the axial direction of the rod 42 in each of the contact pieces 243a and 243b, that is, the contact lengths K1 and K2 is equal to or less than 1/3 of the width K0 of the engaging portion 243, and thus the two sets of contact pieces 243a, 243 The interval K3 of 243b is set to 1/3 or more. By comprising in this way, each said contact piece 243a, 243b hits the rod 42, and it can heighten said effect.

  Further, as shown in FIG. 22, the interval θ1 between the contact points of the pair of contact pieces 243a and 243b is 120 ° in the circumferential direction, that is, the angle θ2 at which the tangents N1 and N2 at the pair of contact points intersect each other is 60. You may arrange | position so that it may become. In this case, the pressing portion 302a of the pressing member 30 is formed of a flat plate spring as described above, so that the three points on the cross section perpendicular to the axis are approximately 120 ° apart, and the pressing force from the pressing member 30 is reduced to a pair. It can give equally to the contact location of contact piece 243a, 243b.

  Further, as shown in FIG. 26, the pressing portion 302a 'of the pressing member 30' may also be formed from a plate-like body having a V-shaped cross section perpendicular to the axis. In this case, the pressing portion 302 a ′ comes into contact with the rod 42 with two lines. Therefore, the pressing force can be dispersed.

  Furthermore, as shown by a pressing portion 302a ″ in FIG. 27, the central portion in the axial direction of the rod 42 may be raised to form a contact portion 304 that actually contacts the rod 42. In this way, the pressing portion 302a '' side is also point-contacted, so that the pressing force can be applied substantially evenly to the two contact pieces 243a and 243b provided at intervals in the axial direction of the rod 42. it can.

  Alternatively, the contact portion 304 is not a point (protrusion) but a protrusion, and the contact length thereof is ½ or less of the width of the pressing portion 302a ″, so that two sets of contact pieces 243a as described above. , 243b can be given a substantially uniform pressing force, the pressing force per unit area can be reduced, and the wear resistance can be improved.

  Further, in the above-described pressing portion 302a ′ shown in FIG. 26, the pair of contact pieces 305a and 305b are spaced apart from each other in the axial direction of the rod 42 as shown in FIG. Two sets of contact pieces 305c and 305d may be provided. In this case, the outer peripheral surface of the rod 42 is supported at four points on the holding member 24 side and at four points on the pressing portion 302a 'side. Thereby, the pressing force per unit area can be reduced and the wear resistance can be improved.

DESCRIPTION OF SYMBOLS 1 Imaging device 2 1 group unit 20 Lens 20a Lens part 20b Outer edge part 21,22,23 Optical element 211,221,231 Lens part 212b; 222b, 222c; 232c Contact surface 212d; 222d, 222e; 232e Adhesive application surface 212f; 222f, 222g; 232g; 212h, 222h Groove portion 212, 222, 232 Holding portion 222k Projection or protrusion 222i, 232i Step 24, 24 'Holding member 243 Engaging portion 243a, 243b; 243c, 243d Contact piece 244 Guide piece 245 Boss 246 Abutting portion 2471, 2472; 2481, 2482 Restriction member 25, 26 Light shielding plate 27, 28, 28 ', 35, 48 Adhesive 29 Holding member 29a Abutting surface 29b Adhesive application surface 30, 30' Pressing member 301 engaging portion 3011, 3012 engaging piece 3 2, 303 Side 302a, 302a ′, 302a ″ Pressing portion 303a Receiving portion 304 Contact portion 305a, 305b; 305c, 305d Contact piece 3 Second group unit 31, 32 Optical element 311, 321 Lens portion 312, 322 Holding portion 316 326 Notch 324 Step 33, 34 Light shielding plate 4 Ultrasonic linear actuator 41 Piezoelectric element 411, 412 Electrode 42 Rod 43 Weight 44, 45 Lead wire 46, 47 External connection terminal 462, 472 Short piece 463, 473 Long piece 464, 474 Bending Portions 465, 475 Inner peripheral surface 5 Housing 51 Rear frame 511 Fitting hole 512, 521 Side wall 513 Base 514 Holding cylinder 516 Storage recess 516a Adjustment hole 517, 527 Guide wall 518, 519 Mounting recess 52 Front frame 520, 530 Abutting surface 526 Fitting hole 53 Front cover Filter 7 Image sensor 8 Space 9 Jig 91 First jig 911, 921 Abutting surface 92 Second jig 922 Positioning pin 93 Adhesive filling means 94, 97, 99 Fixed core 95, 98, 100 Fixed core 96 961, 962 slide core

Claims (8)

In a lens unit formed by bonding a plurality of optical elements to each other,
Each of the optical elements includes a lens portion that forms an optical path, and a holding portion that holds the lens portion from the outer peripheral side,
The holding portion has an abutment surface that defines an interval between the lens portions in optical elements adjacent to each other, and an adhesive application surface that is opposed with a predetermined interval therebetween,
In order to prevent intrusion of the adhesive from the adhesive application surface to the contact surface side at the boundary between the contact surface and the adhesive application surface in the holding part of at least one of the optical elements adjacent to each other. A lens unit having a groove extending in the circumferential direction.   2. The lens unit according to claim 1, wherein in the holding portion, the contact surface is disposed on an outer peripheral side, and an adhesive application surface is disposed on an inner peripheral side.   The lens unit according to claim 1, wherein the groove portion is also formed on the lens portion side of the holding portion.   The lens unit according to claim 1, wherein the optical element is made of a plastic lens, and the lens part and the holding part are integrally molded.   Of the holding portions of the optical elements adjacent to each other, one of the groove portions is formed in an annular shape, and the other is formed with a protrusion or protrusion that loosely fits in the groove portion, and has an outer diameter of the protrusion or protrusion. On the other hand, the lens unit according to any one of claims 1 to 4, wherein an inner diameter of the groove portion is formed larger by a predetermined dimension. In a lens unit formed by joining an optical element having a lens part and an outer edge part extending to the outer peripheral side of the lens part, and a holding member that holds the optical element,
The holding member has a contact surface that contacts the outer edge portion and performs positioning in the optical axis direction, and is opposed to the outer edge portion with a predetermined interval, and an adhesive application surface on which an adhesive is to be applied. Have
A groove extending in the circumferential direction is formed at the boundary between the contact surface and the adhesive application surface to prevent the adhesive from entering the contact surface side from the adhesive application surface. Lens unit.   The lens unit according to any one of claims 1 to 5 is used for at least one of an object side lens unit movable in the optical axis direction or a fixed image side lens unit, and an imaging device is provided. An imaging device characterized by comprising: In a method for joining optical elements or optical elements to a holding member,
The lens unit structure according to claim 1 or 6,
Applying an adhesive to the adhesive application surface in at least one member of the optical elements or in the holding member of the optical element and the holding member;
A step of positioning the abutting surfaces or the outer edge portions in contact with the abutting surfaces;
A step of curing the adhesive, and a method for bonding optical elements.

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