Abstract:
An imaging device having a lens group having lenses; a lens frame that holds said lens group; a base that holds said lens frame; an imaging element that has an imaging area; and a compression coil spring that prescribes the position of the lens frame relative to the imaging element so as to keep the optical axis of the lens group perpendicular to the imaging area of the imaging element. The imaging-element side of the lens frame has an orthogonal surface that is orthogonal to the optical axis of the lens group. The compression coil spring keeps said orthogonal surface in surface contact with an area that surrounds and is parallel to the imaging area of the imaging element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a U.S. national phase application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2015/071480, filed Jul. 29, 2015, and claims benefit of priority to Japanese Patent Application Nos. 2014-158248, filed Aug. 1, 2014, 2014-257330, filed Dec. 19, 2014 and 2015-015724, filed Jan. 29, 2015. The entire contents of these applications are hereby incorporated by reference. 
     
    
     FIELD OF TECHNOLOGY 
       [0002]    The present invention relates to an imaging device, an optical device, an electronic device, a vehicle, and a method for manufacturing an imaging device. 
       BACKGROUND 
       [0003]    An imaging device comprising a lens, a lens frame for holding the lens, a front case to which the lens frame is secured, and a circuit board on which an imaging element is mounted has been proposed (See, for example, Japanese Unexamined Patent Application Publication No. 2012-074934). In the imaging device disclosed in Japanese Unexamined Patent Application Publication No. 2012-074934, a circuit board on which an imaging element is mounted is secured through a plurality of screws to a lens frame that holds a lens, and the position of the imaging element relative to the optical axis of the lens is set through adjusting the amounts to which the individual screws are screwed into the front case. 
       SUMMARY 
       [0004]    However, in the imaging device set forth in Patent Document 1, if a screw is screwed in too far, the circuit board may become tilted, so that the position of the imaging element relative to the optical axis of the lens will not be set properly. 
         [0005]    The present invention was created in contemplation of the causes set forth above, and the object thereof is to provide an imaging device, an optical device, an electronic device, a vehicle, and a method for manufacturing an imaging device, wherein the position of an imaging element relative to the optical axis of the lens group can be set properly. 
         [0006]    In order to achieve the object set forth above, an imaging device according to an aspect of the present invention comprises: 
         [0007]    a lens group; 
         [0008]    a lens frame for holding the lens group; 
         [0009]    a lens frame holding member for holding the lens frame; 
         [0010]    an imaging element having an imaging surface; and 
         [0011]    a perpendicularity maintaining portion for maintaining the optical axis of the lens group in a state that is perpendicular to the imaging surface of the imaging element through setting the position of the lens frame in relation to the imaging element. 
         [0012]    Moreover, the lens frame may have, on the imaging element side, a perpendicular face that is perpendicular to the optical axis of the lens group; and 
         [0013]    the perpendicularity maintaining portion may have a contact maintaining portion for maintaining a state wherein the perpendicular face is in surface contact with a position of the imaging element that is parallel to the imaging surface in the outer peripheral portion of the imaging surface. 
         [0014]    Moreover, the lens frame may have a main unit portion that is cylindrical, and, at one end portion in the cylinder axial direction of the main unit portion, a large-diameter portion that is perpendicular to the cylinder axis and that extends in a direction away from the cylinder axis; and 
         [0015]    the lens frame holding member may have a lens frame holding portion that is provided with an opening portion into which the main unit portion is fitted. 
         [0016]    Moreover, the contact maintaining portion may be structured from an elastic member for biasing the lens frame in the direction that presses the perpendicular face to the imaging surface. 
         [0017]    Moreover, the elastic member may be structured from a coil compression spring. 
         [0018]    Moreover, the lens frame may have a movement constraining portion, in the vicinity of the perpendicular face of the lens frame, for constraining movement of the lens frame in a direction that is perpendicular to the optical axis of the lens group. 
         [0019]    Additionally, the image device may further have: 
         [0020]    a flexible printed circuit board that is shaped as a sheet, and wherein the imaging element is mounted on one surface side thereof and an electronic component is mounted on the other surface side thereof, with the one surface side facing the lens frame holding member; and 
         [0021]    a securing frame, interposed between the lens frame holding member and the flexible printed circuit board, for securing the imaging element to the lens frame holding member, in which case: 
         [0022]    the perpendicularity maintaining portion may be interposed between the lens frame holding member and the flexible printed circuit board and the securing plate, and may be structured from an adhesive agent for bonding the lens frame holding member to the flexible printed circuit board and the securing plate in a state wherein the optical axis of the lens group is perpendicular to the imaging surface of the imaging element. 
         [0023]    Moreover, the electronic component maybe mounted on the other surface side of a facing location, of the flexible printed circuit board, that faces the lens frame holding member in the optical axial direction of the lens group. 
         [0024]    Moreover, the flexible printed circuit board may have an extended portion that extends from the facing location; and 
         [0025]    an adhesive agent may be interposed between the lens frame holding member and the extended portion. 
         [0026]    Additionally, the image device may further include: 
         [0027]    a connecting member that is long and thin, connected to the lens frame holding member in a state protruding to the imaging element side of the lens frame holding member, in which case: 
         [0028]    the securing plate may have a through hole, in a position that corresponds to the connecting member that is connected to the lens frame holding member, into which the connecting member is inserted in a state wherein the inner edge portion is away from a side face of the connecting member; and 
         [0029]    an adhesive agent may be interposed between the connecting member and the inner edge of the through hole. 
         [0030]    Additionally, the image device may further have: 
         [0031]    a circuit board whereon the imaging element and an electronic component are mounted on the same surface side; and 
         [0032]    a heat dissipating grease, interposed between the lens frame holding member and the electronic component, for carrying, to the lens frame holding member, heat that is produced by the electronic component, in which case: 
         [0033]    the lens frame holding member may be disposed so as to cover the surface side of the circuit board on which the imaging element and the electronic components are mounted, may maintain a state wherein the optical axis of the lens group is perpendicular to the imaging surface of the imaging element, and may have a grease filling duct for filling the heat dissipating grease between the lens frame holding member and the electronic component. 
         [0034]    Moreover, the grease filling duct may be structured from a through hole that is formed in a position that faces the electronic component, in the direction that is perpendicular to the face of the circuit board whereon the imaging element and the electronic component are mounted, in the lens frame holding member. 
         [0035]    Moreover, an optical device according to another aspect according to the present invention is provided with an imaging device as set forth above. 
         [0036]    Moreover, an electronic device according to a further aspect according to the present invention is provided with an imaging device as set forth above. 
         [0037]    Moreover, a vehicle according to a yet further aspect according to the present invention is provided with an imaging device as set forth above. 
         [0038]    Moreover, a method for manufacturing and imaging device according to an even further aspect according to the present invention includes: 
         [0039]    a step for securing the lens group to the lens frame; 
         [0040]    a step for securing the lens frame to the lens frame holding member; and 
         [0041]    a step for supporting a state wherein the optical axis of the lens group is caused to be perpendicular to the imaging surface of the imaging element through setting the position the position of the lens frame relative to the imaging element. 
       Effects of the Invention 
       [0042]    The present invention enables the position of an imaging element relative to the optical axis of a lens to be set properly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0043]      FIG. 1  is an assembly perspective diagram of an imaging device according to an example according to the present invention. 
           [0044]      FIG. 2A  is a top view of the exterior of an imaging device  1000  according to the example. 
           [0045]      FIG. 2B  is a back view of the exterior of an imaging device  1000  according to the example. 
           [0046]      FIG. 2C  is a left side view of the exterior of an imaging device  1000  according to the example. 
           [0047]      FIG. 2D  is a front view of the exterior of an imaging device  1000  according to the example. 
           [0048]      FIG. 2E  is a right side view of the exterior of an imaging device  1000  according to the example. 
           [0049]      FIG. 3  is a partial cross-sectional view along the section A-A in  FIG. 2B , for the example. 
           [0050]      FIG. 4  is a plan view of the circuit board in the example. 
           [0051]      FIG. 5  is a schematic side view of the circuit board in the example. 
           [0052]      FIG. 6  is an assembly perspective diagram of an imaging device according to another example according to the present invention. 
           [0053]      FIG. 7  is an assembly perspective diagram of an imaging device according to the other example. 
           [0054]      FIG. 8  is a perspective diagram of an imaging device according to the other example. 
           [0055]      FIG. 9  is a side view of an imaging device according to the other example. 
           [0056]      FIG. 10  is an assembly perspective diagram of an imaging device according to a further example according to the present invention. 
           [0057]      FIG. 11A  is a front view of an imaging device according to the further example. 
           [0058]      FIG. 11B  is a cross-sectional diagram along the section B-B in  FIG. 11A . 
           [0059]      FIG. 12  is a perspective diagram of a camera according to a yet further example according to the present invention. 
           [0060]      FIG. 13  is cross-sectional diagram of an imaging device according to a modified example. 
           [0061]      FIG. 14  is cross-sectional diagram of an imaging device according to a modified example. 
       
    
    
     DETAILED DESCRIPTION 
       [0062]    Imaging devices according to various examples according to the present invention will be explained in detail below in reference to the drawings. 
       Example 1 
       [0063]    An imaging device  1000  according to the present example, as illustrated in  FIG. 1 , comprises a lens  1 , a lens frame  2 , a base (a lens frame holding member)  3 , an imaging element  4 , a circuit board  5 , a coil compression spring (a contact maintaining portion)  6 , and screws  7 . This imaging device  1000  has an external appearance as shown in  FIG. 2A  through  FIG. 2E . 
         [0064]    The lens  1  is structured from a convex lens, as illustrated in  FIG. 3 , for example. There are two lenses  1 , structuring a single lens group. In one example, the two lenses can be plano-convex and bi-convex. 
         [0065]    The lens frame  2  has, on the imaging element  4  side, a perpendicular face  2   b  that is perpendicular to the optical axis of the lens group that is formed from the two lenses  1 . The lens frame  2  has a cylindrical main unit portion  2   e , and a flange-shaped large diameter portion  2   a  that extends out in the direction away from the cylinder axis, perpendicular to the cylinder axis, connected to one end, in the cylinder axial direction, of the main unit portion  2   e . The lenses  1  are disposed within the main unit portion  2   e . The imaging element  4  side, in the cylinder axial direction, of the large diameter portion  2   a  structures the perpendicular face  2   b . The lens frame  2  is disposed in a state wherein the perpendicular face  2   b  of the large diameter portion  2   a  contacts the imaging surface  4   a  of the imaging element  4 . The lens frame  2  is formed from, for example, a resin material or a metal material such as aluminum. When the lens  1  is secured to the lens frame  2  through, for example, a method such as heat caulking, preferably the lens frame  2  is formed from a resin material that is suitable for heat caulking. Resin materials that are suitable for heat caulking include, for example, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene (ABS), polyamide resin (PA), and the like. 
         [0066]    The base  3  holds the lens frame  2 . The base  3  has a lens frame holding portion  3   d  that is provided with an opening portion  3   e  into which is fitted an end portion of the lens frame  2  on the side that is opposite from the one end portion that is on the large diameter portion  2   a  side of the main unit portion  2   e  thereof. Positioning protrusions  3   a  and  3   b  (referencing  FIG. 2B ) for determining the position of the circuit board  5  protrude on the circuit board  5  side of the base  3 . This base  3  is formed from, for example, a resin material or a metal material such as aluminum. The resin material may be, for example, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylonitrile butadiene styrene (ABS), polyamide resin (PA), or the like. 
         [0067]    The imaging element  4  captures an image of the photographic subject that is focused onto the imaging surface  4   a  through the lens group that is formed from the two lenses  1 . The imaging surface  4   a  corresponds to the part in the package, of the imaging element  4 , that receives light from the outside. The imaging element  4  is provided with a solid-state imaging element such as a CCD (charge-coupled device), a CMOS (complementary metal oxide semiconductor), or the like, for capturing an image of the photographic subject that is focused onto the imaging surface  4   a  through the lens group. Moreover, the position of contact of the lens frame  2  on the outer peripheral portion of the imaging surface  4   a  in the package of the imaging device  4  is flat, and is parallel to the imaging surface  4   a . The imaging element  4  is secured to the circuit board  5 . The imaging element  4  is mounted on the circuit board  5  through a conductive material (not shown) that is provided on the circuit board  5 . The conductive material may be, for example, solder. 
         [0068]    As illustrated in  FIG. 1 , the circuit board  5  has through holes  5   a  and  5   b  for positioning of the circuit board  5 , and through holes  5   c  and  5   d  for insertion of screws  7  for securing the circuit board  5  to the base  3 . The circuit board  5 , as illustrated in  FIG. 2B , is screwed to a securing portion  3   c  of the base  3  through screws  7  that are inserted into the through holes  5   c  and  5   d  in a state wherein the positioning protrusions  3   a  and  3   b  of the base  3  are fitted into the two through holes  5   a  and  5   b  for positioning. 
         [0069]    Note that when the imaging element  4  is mounted on the circuit board  5 , as illustrated in  FIG. 5 , the circuit board  5  may be warped, through heating, or the like, to the side that is the surface where the imaging element  4  is provided, as illustrated in  FIG. 5  (referencing the dotted line  5 A). In the present example, as illustrated in  FIG. 4  and  FIG. 5 , the conductive materials  8  are provided on the face of the circuit board  5  that is on the side that is opposite from the face wherein the imaging element  4  is provided. As illustrated in  FIG. 4 , the conductive materials  8  are provided at positions that correspond to the peripheral edge portion of the imaging element  4  on the face that is on the side opposite from the face of the circuit board  5  whereon the imaging element  4  is mounted. The conductive material  8  may be, for example, solder. Doing so enables suppression of the warping of the circuit board  5  that is produced when the imaging element  4  is mounted on the circuit board  5 . 
         [0070]    The coil compression spring  6  is an elastic member for biasing the lens frame  2  in the direction in which the perpendicular face  2   b  is pressed against the imaging surface  4   a  of the imaging element  4 . The coil compression spring  6 , in a state wherein it is wound onto the main unit portion  2   e  of the lens frame  2 , is held between the face  2   c  of the large diameter portion  2   a  on the main unit portion  2   e  side and the outer peripheral portion of the opening portion  3   e  of the base  3 . The coil compression spring  6 , when disposed in a compressed state, produces a force in the direction that presses the lens frame  2  against the imaging element  4 , through the force of restitution of the coil compression spring  6 . 
         [0071]    Through this force, a state is preserved wherein the perpendicular face  2   b  of the lens frame  2  makes surface contact with a position that is parallel to the imaging surface  4   a  on the outer peripheral portion of the imaging surface  4   a  of the imaging element  4 . Through this, the base  3  can hold the lens frame  2  so that the optical axis L 1  of the lens group that is structured from the two lenses  1  will be perpendicular to the imaging surface  4   a  of the imaging element  4 . In this way, the coil compression spring  6  produces a force that presses the lens frame  2  against the imaging element  4 , to maintain a state wherein the perpendicular face  2   b  of the lens frame  2  is in surface contact with a position that is parallel to the imaging surface  4   a  on the outer peripheral portion of the imaging surface  4   a  of the imaging element  4 . That is, the coil compression spring  6  structures a perpendicularity maintaining portion, for maintaining the optical axis L 1  of the lens group that is structured from the two lenses  1  in a state that is perpendicular to the imaging surface  4   a  of the imaging element  4 , through causing the perpendicular face  2   b  of the lens frame  2  to make surface contact with a position that is parallel to the imaging surface  4   a , on an outer peripheral portion of the imaging surface  4   a  of the imaging element  4 . 
         [0072]    In assembling the imaging device, typically the position of the imaging element is adjusted using the position of the lens frame as the reference. However, the method wherein the position of the imaging element is adjusted using the position of the lens frame as the reference requires adjustments that take into consideration the variability of the slope of the imaging element relative to the circuit board, causing the adjusting operation to be complex. 
         [0073]    In contrast, with the imaging device  1000  according to the present example, even if there is variability in the slope of the imaging element  4  in relation to the circuit board  5 , a surface contact can be made between the perpendicular face  2   b  of the lens frame  2  and a position that is parallel to the imaging surface  4   a , on the outer peripheral portion of the imaging surface  4   a  of the imaging element  4 , making it possible to preserve a state wherein the optical axis L 1  of the lens group that is structured from the two lenses  1  is perpendicular to the imaging surface  4   a  of the imaging element  4 . This enables prevention of a negative effect on the resolution, or a reduction in guaranteed resolution in the design, in the image or video captured through imaging with the imaging device  1000  that would be caused by the optical axis L 1  of the lens group that is structured from the two lenses  1  being at an angle relative to the direction that is perpendicular to the imaging surface  4   a  of the imaging element  4 . 
         [0074]    Moreover, in the imaging device  1000  according to the present example, the lens frame  2  has a main unit portion  2   e  and a large diameter portion  2   a , and the base  3  has a lens frame holding portion  3   d  that is provided with an opening portion  3   e  into which the main unit portion  2   e  fits. Through this, the lens frame  2  is held by the lens frame holding portion  3   d , making it possible to prevent the optical axis L 1  of the lens group that is structured from the two lenses  1  from being off-axis. 
         [0075]    Moreover, in the imaging device  1000  according to the present example, the elastic force of the coil compression spring  6  can be used to cause the imaging surface  4   a  of the imaging element  4  to always make contact with the perpendicular face  2   b  of the lens frame  2 . 
         [0076]    Moreover, the coil compression spring  6  can produce the desired elastic force more easily than a leaf spring, or the like, and has a simple structure, and thus has the benefit of being incorporated into the imaging device  1000  easily. 
       Example 2 
       [0077]    An imaging device  2000  according to the present example, as illustrated in  FIG. 6  and  FIG. 7 , comprises a lens barrel (lens frame)  10 , a lens barrel holding member (lens frame holding member)  20 , an imaging element  4 , a flexible printed circuit board  40 , a securing plate  50 , screws  60 , and an adhesive agent. Note that structures that are identical to those in the first example are assigned reference symbols that are the same as those in  FIG. 1 . The imaging device  2000  will be explained as that which is attached to a vehicle. Here “vehicle” refers to, for example, a vehicle for transporting passengers or cargo, such as a train or an automobile. 
         [0078]    A lens  1  that has an optical axis L 1  is secured to the lens barrel  10 . The lens barrel  10  is formed from a resin material, or the like, into a cylinder, and the lens  1  is held therein. Male threads, for securing the lens barrel  10  to the lens barrel holding member  20 , are formed on the outer peripheral surface of the lens barrel  10 . 
         [0079]    The lens barrel holding member  20  holds the lens barrel  10  in a state wherein the lens barrel  10  is secured by a locking screw  2003 . The lens barrel holding member  20  is formed from a resin material, or the like. The lens barrel holding member  20  has a lens barrel holding portion (lens frame holding portion)  21  that is provided with a through hole  21   a  into which the lens barrel  10  is inserted, and a through hole  22  that extends in a direction that is essentially perpendicular to the axis of the through hole  21   a . Female threads (not shown), for screwing together with the male threads  10   a  of the lens barrel  10 , are formed in the through hole  21   a . Female threads for screwing together with the locking screw  2003  are formed on the inner peripheral surface of the through hole  22 . In the through hole  21   a , the axis thereof is essentially coaxial with the optical axis L 1 . The lens barrel holding member  20  is provided with a sidewall portion  24  that protrudes toward the securing plate  50  side from the peripheral portion of the back face  23  that faces the securing plate  50 , two screw holes  25  that are open in the back face  23 , and two flange portions  26  for attaching to the vehicle. The sidewall portion  24  defines a region for holding an adhesive agent between the sidewall portion  24  and the securing plate  50 . Screws  60  are screwed into the screw holes  25 . The lens barrel holding member  20  holds the lens barrel  10  in a state wherein the tip end portion of the locking screw  2003  that is inserted into the through hole  22  makes pressing contact against the outer peripheral side face of the lens barrel  10  that is screwed into the through hole  21   a.    
         [0080]    A flexible printed circuit board  40  is shaped as a sheet, with the imaging element  4  mounted on one surface side thereof, and electronic components  43 , such as IC chips, resistors, capacitors, and the like, mounted on the other surface side thereof, where the one surface side whereon the imaging element  4  is mounted faces the lens barrel holding member  20 . The flexible printed circuit board  40  has, in the direction of the optical axis L 1  of the lens group that is structured from the two lenses  1 , a facing location  45  that faces the lens barrel holding member  20 , and an extended portion  44  that extends from the facing location  45 . Two through holes  42 , into which screws  60  are inserted, are provided in the facing location  45 . An interconnection (not shown) that is connected to the imaging element  4  is provided at a forward region  41   a  of the surface side on which the imaging element  4  is mounted in the facing location  45 . Moreover, an interconnection (not shown) that is connected to the electronic component  43  is provided at a rearward region  41   b  of the surface side on which the electronic component  43  is mounted on the facing location  45 . Both of the through holes  42  have inner diameters that are larger than the outer diameters of the shaft portions of the screws  60 . The extended portion  44  corresponds to the part that is connected to the connector on the vehicle side when the imaging device  2000  is attached to the vehicle. 
         [0081]    The securing plate  50  is interposed between the lens barrel holding member  20  and the flexible printed circuit board  40 , and is for securing the position of the imaging element  4 . The securing plate  50  has two through holes  52  into which are inserted respective two screws, in a state wherein the inner edge portions are away from the side surfaces of the screws  60 , at positions corresponding to the screws  60  that are connected to the lens barrel holding member  20 . Moreover, an essentially rectangular opening portion  51  that is slightly larger than the external dimension of the imaging element  4 , in the plan view, is provided in the securing plate  50 . The securing plate  50  is made from metal, or the like. Each of the through holes  52  have inner diameters that are larger than the outer diameters of the shaft portions of the screws  60 . The securing plate  50 , in a state wherein the imaging element  4  is disposed within the opening portion  51 , secures the imaging element  4 , through an adhesive agent (not shown) that is filled into the region between the outer edge portions of the imaging element  4  and the inner edge portions of the opening portion  51 . 
         [0082]    The screws  60  are screwed into the lens barrel holding member  20 , and in a state wherein they protrude on the imaging element  4  side of the lens barrel holding member  20 , they structure a connecting member that is connected to the lens barrel holding member  20 . Each screw  60  is provided with a shaft portion wherein threads are cut, and a head portion that has an outer diameter that is larger than the outer diameter of the shaft portion. The shaft portion of the screw  60  partitions the total thread wherein threads are cut along the axial direction as a whole, and the outer diameter thereof is smaller than the inner diameter of the through holes  52  of the securing plate  50  and smaller than the inner diameter of the through holes  42  of the flexible printed circuit board  40 . In the head portion of the screw  60 , a plus-shaped hole, to which the tool is applied when the screw is screwed in, is formed in the surface thereof, and the outer dimensions are larger than the inner diameter of the through holes  52  of the securing plate  50  and larger than the inner diameter of the through holes  42  of the flexible printed circuit board  40 . The screws  60  are to prevent the securing plate  50  and the flexible printed circuit board  40  from becoming detached from the lens barrel holding member  20 . 
         [0083]    Moreover, in a state wherein the screws  60  are screwed into the screw holes  25  and the tip end portions of the shaft portions of the screws  60  are in contact with the bottoms of the screw holes  25 , uniform gaps are secured between the back face  23  of the lens barrel holding member  20  and the front face  53  of the securing plate  50 , and between the flexible printed circuit board  40  and the head portions of the screws  60 . Here the securing plate  50  is formed with dimensions to produce the prescribed gap between the flexible printed circuit board  40 , which is disposed on the back face thereof, and the head portions of the screws  60 . 
         [0084]    An adhesive agent  70  is filled between the lens barrel holding member  20  and the securing plate  50 . The adhesive agent  70 , as illustrated in  FIG. 8 , is interposed between the lens barrel holding member  20  and the securing plate  50 , to secure them both in a non-contact state. The adhesive agent  70  is provided (either filled or coated) between the sidewall portion  24  of the back face  23  side of the lens barrel holding member  20  and the outer peripheral edge portion of the securing plate  50 , in a state wherein the front face  53  of the securing plate  50  is facing the back face  23  of the lens barrel holding member  20 , without making contact, with a prescribed gap therebetween. The adhesive agent  70  is cured through, for example, exposure to ultraviolet radiation. Here the adhesive agent  70  may be filled between the lens barrel holding member  20  and the securing plate  50  after they have been disposed facing each other at the time of assembly, or may be coated onto the back face  23  side of the lens barrel holding member  20 , or onto the outer edge portion of the securing plate  50 , prior to the lens barrel holding member  20  being disposed facing the securing plate  50 . 
         [0085]    The position in the adhesive agent  80  that is positioned on the inside of the through hole  52  of the securing plate  50  is interposed between the screw  60  and the inner edge of the through hole  52  of the securing plate  50 . Moreover, the position in the adhesive agent  80  that is positioned on the back surface side of the flexible printed circuit board  40  is interposed between the head portion of the screw  60  and the back face of the flexible printed circuit board  40 . The adhesive agent  80  is filled or coated between the screw  60  and the inner edge of the through hole  52  of the securing plate  50  and between the head portion of the screw  60  and the rearward region  41   b  of the flexible printed circuit board  40 , in a state wherein the screw  60  is screwed into the screw hole  25  of the lens barrel holding member  20 . In this case, the state will be one wherein the back face  23  of the lens barrel holding member  20  is away from the front face  53  of the securing plate  50 , a state wherein the securing plate  50  is away from the flexible printed circuit board  40 . The adhesive agent  80  is structured from an adhesive agent that is, for example, cured through exposure to ultraviolet radiation. 
         [0086]    An adhesive agent  90 , as illustrated in  FIG. 9 , is interposed between the outer edge portion of the lens barrel holding member  20  and the extended portion  44  of the flexible printed circuit board  40 . The existence of this adhesive agent  90  enables avoidance of damage to the connecting portions wherein the electronic components  43  are connected electrically to the interconnections that are provided on the flexible printed circuit board  40 , even if the extended portion  44  of the flexible printed circuit board  40  is bent when, for example, the imaging device  2000  is attached to the vehicle. That is, interconnections that are provided on a rearward region  41   b  of the flexible printed circuit board that are wider than the region defined by the back face  23  of the lens barrel holding member  20  that faces the front face  53  of the securing plate  50  are connected to a plurality of electronic components  43  through a conductive material, such as solder. 
         [0087]    Moreover, the adhesive agent  90  is provided along the outer edge of the lens barrel holding member  20  in the vicinity of the boundary between the rearward region  41   b  of the flexible printed circuit board  40  and the extended portion  44 . The adhesive agent  90  is provided at the end of a region that is wider than the rearward region  41   b  wherein the plurality of electronic components  43  is disposed. In this way, the adhesive agent  90  is provided (filled or coated) between the lens barrel holding member  20  and the forward region  41   a  of the flexible printed circuit board  40 . The adhesive agent  90  is structured from an adhesive agent that is, for example, cured through exposure to ultraviolet radiation. 
         [0088]    The method for assembling the imaging device  2000  according to the present example will be explained next. First the flexible printed circuit board  40  and the securing plate  50  are disposed facing each other with a prescribed gap (in a non-contact state) to the rear of the lens barrel holding member  20  that holds the lens barrel  10 . In this case, the flexible printed circuit board  40  and the securing plate  50  are maintained in space by a prescribed holding mechanism. Following this, the shaft portions of the screws  60  are inserted into the through holes  52  of the securing plate  50  and into the through holes  42  of the flexible printed circuit board  40 , from the rear of the flexible printed circuit board  40 . 
         [0089]    Following this, the tip end portions of the shaft portions of the screws  60  are screwed into the screw holes  25  of the lens barrel holding member  20 . In this case, the securing plate  50  and the flexible printed circuit board  40  are held in a non-contact state. 
         [0090]    Thereafter, the adhesive agent  70  is filled between the sidewall portion  24  of the back surface side of the lens barrel holding member  20  and the outer edge portion of the securing plate  50 . Here the adhesive agent  70  may be coated instead in advance onto the back surface side of the lens barrel holding member  20  or onto the outer edge portions of the securing plate  50 . 
         [0091]    Following this, the adhesive agent  80  is filled between the screws  60 , the fastening plate  50 , and the flexible printed circuit board  40 , and the adhesive agent  90  is filled between the lens barrel holding member  20  and the flexible printed circuit board  40 . 
         [0092]    Following this, a prescribed optical axis adjusting apparatus (not shown) is used to adjust the optical axial position (to adjust the position in the direction of the optical axis L 1 , the position in the direction perpendicular to the optical axis L 1 , and the slope relative to the optical axis L 1 ), after which the adhesive agents  70 ,  80 , and  90  are exposed to ultraviolet radiation to cure the adhesive agents  70 ,  80 , and  90 . The assembly of the imaging device  2000  is completed thereby. In this way, in a state wherein the adhesive agents  70 ,  80 , and  90  have been cured, the lens barrel holding member  20  will function as a perpendicularity maintaining portion that is bonded to the flexible printed circuit board  40  and the securing plate  50 , in a state wherein the optical axis L 1  of the lens group that is structured from the two lenses  1  is perpendicular to the imaging surface  4   a  of the imaging element  4 . 
         [0093]    As explained above, given the imaging device  2000  according to the present example, the adhesive agent  70  that is interposed between the lens barrel holding member  20  and the securing plate  50 , and the adhesive agent  80  that is interposed between the head portions of the screws  60  and the flexible printed circuit board  40 , are cured after setting of the optical axis of the imaging element  4 . Here the position of the optical axis of the imaging element  4  in the direction of the optical axis L 1  of the lens group, the position thereof in the direction that is perpendicular to the optical axis L 1  and the slope relative to the optical axis are set by adjusting the optical axis L 1  of the imaging element  4 . This makes it possible to prevent a shift in the optical axis of the imaging element  4  after the optical axis adjustment has been completed. Moreover, detachment of the securing plate  50  and the imaging element  4 , even if, for example, the adhesive agent  70  between the lens barrel holding member  20  and the securing plate  50  were to come off due to a physical shock from the outside, is prevented by the adhesive agent  80  that is interposed between the head portions of the screws  60 , the shafts of the screws  60 , and the securing plate  50 . 
         [0094]    Moreover, in the imaging device  2000  according to the present example, an adhesive agent  90  is provided interposed between the lens barrel holding member  20  and the flexible printed circuit board  40 . This enables avoidance of damage to the connecting portions between the electronic components  43  and the interconnections, through the ability to prevent bending of the connecting portions between the electronic components  43  and the interconnections when the imaging device  2000  is equipped in the vehicle. This enables production of an imaging device  2000  that can achieve a simplification in structure, and that is able to improve manufacturability, and improve reliability in functioning through resisting positional shift through securing after adjustment of the position of the imaging element  4  in relation to the optical axis L, and with no reduction in durability to mechanical shock in the event of a physical shock such as dropping, and without damaging the connecting portions between the electronic components and the interconnections, through merely providing the adhesive agent  90 . 
       Example 3 
       [0095]    As illustrated in  FIG. 10 , the imaging device  3000  according to the present example is provided with a lens barrel (lens frame)  3010 , a lens barrel holding member (a lens frame holding member)  3020 , an imaging element  4 , a communicating module  3042 , a circuit board  3040 , and a securing plate  3050 . Moreover, the imaging device  3000  is further provided with adhesive agents  3061 ,  3062 , and  3063 , screws, and heat dissipating grease  3090 . Note that structures that are identical to those in the first example are assigned reference symbols that are the same as those in  FIG. 1 . In the imaging device  3000 , as illustrated in  FIG. 11A , the lens barrel  3010  is secured to a position that is offsetted to one side from the center portion in the lengthwise direction of the lens barrel holding member  3020  that is long when viewed from the front face side. Moreover, as illustrated in  FIG. 11B , the imaging element  4  and the communicating module  3042  are disposed, on the circuit board  3040 , lined up in the lengthwise direction of the lens barrel holding member  3020 . 
         [0096]    Returning to  FIG. 10 , a lens  1  that has an optical axis L 1  is secured to a lens barrel  3010 . The lens barrel  3010  is formed from a resin material, or the like, into a cylinder, and the lens  1  is held therein. 
         [0097]    The imaging element  4  and the communicating module (an electronic component)  3042  are mounted on the same side of the circuit board  3040 . Two through holes  3043 , into which screws  3060  (referencing  FIG. 11B ) are inserted, are formed on both sides of the imaging element  4  in the circuit board  3040 . The circuit board  3040  is disposed so that the side whereon the imaging element  4  and the communicating module  3042  are mounted faces the lens barrel  3010  side. 
         [0098]    The lens barrel holding member  3020  holds the lens barrel  3010  in a state wherein the lens barrel  3010  is secured by a locking screw  3002 . This lens barrel holding member  3020  is disposed so as to cover the surface side of the circuit board  3040  wherein the imaging element  4  and the communicating module  3042  are mounted. The lens barrel holding member  3020  is formed from a material with relatively high thermal conductivity, such as metal. The lens barrel holding member  3020  is provided with a lens barrel holding portion (a lens frame holding portion)  3021  for holding a lens barrel  3010 , and a module covering portion  3029 , provided adjacent to the lens barrel holding portion  3021 , for covering the communicating module  3042 . The lens barrel holding portion  3021  is provided with a through hole  3021   a  into which the lens barrel  3010  fits, and a through hole  3022  that extends in a direction that is essentially perpendicular to the axis of the through hole  3021   a . The through hole  3022  has female threads, for screwing together with the locking screw  3002 , formed in the inner peripheral surface thereof. The lens barrel holding member  3020  holds the lens barrel  3010  in a state wherein the tip end portion of the locking screw  3002  that is inserted into the through hole  3022  is in contact with the outer peripheral side face of the lens barrel  3010  that is fitted into the through hole  3021   a . In this case, the axis of the through hole  3021   a  is essentially coincident with the optical axis L 1  of a lens group that is structured from two lenses  1 . Moreover, the lens barrel holding member  3020 , as illustrated in  FIG. 11B , is provided with screw holes  3025  into which screws  3060  are screwed. Moreover, the lens barrel holding member  3020  maintains the optical axis L 1  of the lens group that is structured from the two lenses  1  in a state that is perpendicular relative to the imaging surface  4   a  of the imaging element  4 , and has a through hole (a grease filling duct)  3023  for filling heat dissipating grease  3090  between the lens barrel holding member  3020  and the communicating module  3042 . This through hole  3023  is formed, in the lens barrel holding member  3020 , in a position that faces the communicating module  3042  in a direction that is perpendicular to the surface of the circuit board  3040  on which the imaging element  4  and the communicating module  3042  are mounted. 
         [0099]    The securing plate  3050  is for securing the imaging element  4 . The securing plate  3050  is formed in a plate shape from metal, or the like. An essentially rectangular opening portion  3051  that is slightly larger than the external dimension of the imaging element  4 , in the plan view, and two through holes  3052 , through which screws  3060  are passed, are provided in the securing plate  3050 . The securing plate  3050 , in a state wherein the imaging element  4  is disposed within the opening portion  51 , secures the imaging element  4 , through an adhesive agent  3062  that is filled into the region between the outer edge portions of the imaging element  4  and the inner edge portions of the opening portion  3051 . The adhesive agent  3062  is cured through, for example, exposure to ultraviolet radiation. 
         [0100]    As illustrated in  FIG. 11B , screws  3060  are screwed into the lens barrel holding member  3020 . The screws  3060  are to prevent the securing plate  3050  and the circuit board  3040  from becoming detached from the lens barrel holding member  3020 . Moreover, in a state wherein the screws  3060  are screwed into the screw holes  3025  and the tip end portions of the shaft portions of the screws  3060  are in contact with the bottoms of the screw holes  3025 , a gap is secured between the lens barrel holding member  3020  and the securing plate  3050 . 
         [0101]    Returning to  FIG. 10 , an adhesive agent  3061  is filled between the lens barrel holding member  3020  and the securing plate  3050 . The adhesive agent  3061  is filled between the lens barrel holding member  3020  and the securing plate  3050  in a state wherein the lens barrel holding member  3020  is in contact with the securing plate  3050 . The adhesive agent  3061  is cured through, for example, exposure to ultraviolet radiation. 
         [0102]    An adhesive agent  3062  is filled between the lens barrel holding member  3020  and the circuit board  3040 , on the side of the circuit board  3040  with the communicating module  3042 . The adhesive agent  3062  is cured through, for example, exposure to ultraviolet radiation. 
         [0103]    The heat dissipating grease  3090 , as illustrated in  FIG. 11B , is interposed between the lens barrel holding member  3020  and the communicating module  3042 , and is for carrying, to the lens barrel holding member  3020 , the heat that is produced in the communicating module  3042 . The heat dissipating grease  3090  is filled or coated between the lens barrel holding member  3020  and the circuit board  3040  through the through hole  3023  of the lens barrel holding member  3020  in a state wherein the screws  3060  that have been inserted through the through holes  3043  of the circuit board  3040  and the through holes  3052  of the securing plate  3050  have been screwed into the screw holes  3025  of the lens barrel holding member  3020 . 
         [0104]    The method for assembling the imaging device  3000  according to the present example will be explained next. First the securing plate  3050  and the circuit board  3040  are disposed behind the lens barrel holding member  3020  that is holding the lens barrel  3010 . Following this, the shaft portions of the screws  3060  are inserted into the through holes  3052  of the securing plate  3050  and into the through holes  3043  of the flexible printed circuit board  3040 , from the rear of the circuit board  3040 . 
         [0105]    Following this, the tip end portions of the shaft portions of the screws  3060  are screwed into the screw holes  3025  of the lens barrel holding member  3020 . 
         [0106]    Following this, the adhesive agents  3061  and  3062  are filled between back face side of the lens barrel holding member  3020  and the securing plate  3050 , and the adhesive agent  3063  is filled between the lens barrel holding member  3020  and the circuit board  3040  on the circuit board  3040  side. 
         [0107]    Following this, a prescribed optical axis adjusting apparatus (not shown) is used to adjust the optical axial position (to adjust the position in the direction of the optical axis L 1 , the position in the direction perpendicular to the optical axis L 1 , and the slope relative to the optical axis L 1 ), after which the adhesive agents  3061 ,  3062 , and  3063  are exposed to ultraviolet radiation to cure the adhesive agents  3061 ,  3062 , and  3063 . 
         [0108]    Finally, the heat dissipating grease  3090  is filled into the lens barrel holding member  3020  through the through hole  3023 . In this case, a syringe (not shown), for example, that is filled with heat dissipating grease is inserted into the through hole  3023 , and the heat dissipating grease  3090  is filled between the lens barrel holding member  3020  and the circuit board  3040 . The assembly of the imaging device  3000  is completed thereby. 
         [0109]    Conventionally, the coating of the heat dissipating grease onto the circuit board typically is performed prior to adjusting the optical axis of the imaging element  4 . In such a case, the heat dissipating grease that has been coated onto the circuit board interferes with the lens barrel holding member  20 , and the like, when the optical axis of the imaging element  4  is adjusted, which may reduce the accuracy of the adjustment of the optical axis. 
         [0110]    In contrast, in the imaging device  3000  according to the present example, the adhesive agents  3061  and  3062  that are interposed between the lens barrel holding member  3020  and the securing plate  3050  are cured after adjustment of the optical axis of the imaging element  4 , after which the heat dissipating grease  3090  is filled. Because the adhesive agents  3061  and  3062  have been cured, this enables prevention of shifting of the optical axis of the imaging element  4  when the heat dissipating grease  3090  is filled. 
       Example 4 
       [0111]    As illustrated in  FIG. 12 , the imaging devices  1000 ,  2000 , and  3000  of the various examples described above were built into cameras  100  according to the present example. The camera at  100  may be, for example, a consumer camera, such as a digital camera, a vehicle-mounted camera, a monitoring camera, a camera mounted for medical treatment (such as an endoscope camera), a camcorder (a movie camera) for capturing video, various types of inspection cameras, a camera for a robot, or the like. 
       Modified Examples 
       [0112]    While examples according the present invention have been explained above, the present invention is not limited to the examples set forth above. For example, as illustrated in  FIG. 13 , it may be an imaging device  4000  wherein the lens frame holding portion  3   d  of the base  3  has been designed in consideration of the lens frame  4002  being tilted within the lens frame holding portion  3   d . In the imaging device  4000 , as illustrated in  FIG. 14 , the lens frame holding portion  3   d  is designed so as to hold the lens frame  4002  with a gap that allows the optical axis L 2  of the lens group, which is structured from two lenses  1 , to tilt relative to the optical axis L 1  in the design. With this imaging device  4000 , if the imaging surface  4   a  of the imaging element  4  is inclined relative to the optical axis L 1  in the design, then the lens frame  4002  may be tilted to cause the optical axis of the lens group L 2  that is structured from the two lenses  1  to be perpendicular relative to the imaging surface  4   a  of the imaging element  4 . 
         [0113]    Moreover, in this imaging device  4000 , a coil compression spring  6  that is wound onto the main unit portion  2   e  of the lens frame  4002  is disposed in a state wherein it is compressed between a face  2   c  that is on the side opposite from a perpendicular face  2   b  of a large diameter portion  2   a , and a lens frame holding portion  3   d  of a base  3 . Because of this, a force constantly acts on the lens frame  4002  pressing it against the imaging surface  4   a  of the imaging element  4 . Through this, a position that is parallel to the imaging surface  4   a  in the outer peripheral portion of the imaging surface  4   a  of the imaging element  4  makes surface contact with the perpendicular face  2   b  of the lens frame  4002 , to cause the optical axis L 2  of the lens group that is structured from the two lenses  1  to be perpendicular relative to the imaging surface  4   a  of the imaging element  4 . This enables the optical axis L 2  of the lens group to be set to be perpendicular to the imaging surface  4   a  of the imaging element  4 , without adjusting the slope of the optical axis L 2  of the lens group relative to the imaging surface  4   a  of the imaging element  4 , even if there is variability in, for example, the tilt of the imaging element  4  relative to the circuit board  5 . 
         [0114]    This structure enables prevention of a negative effect on the resolution, or a reduction in guaranteed resolution in the design, in the image or video captured through imaging using the imaging device  4000 , that would be caused by a tilt in the optical axis L 2  of the lens group that is structured from the two lenses  1  in relation to the imaging surface  4   a  of the imaging element  4 . 
         [0115]    Moreover, the lens frame  4002  has a movement constraining portion  4002   f  for constraining movement in the direction that is perpendicular to the optical axis L 1  in the design of the lens frame  4002 , on the periphery of the perpendicular face  2   b  of the lens frame  4002 . Specifically, the movement constraining portion  4002   f  is provided at the tip end portion of a large diameter portion  2   a . Given this, as illustrated in  FIG. 14 , the lens frame  4002  tilts, rotating centered on the vicinity P of the center of the optical axis of the imaging element  4 . This enables elimination of the misalignment of the optical axis L 2  of the lens group that is structured from the two lenses  1  with the axis of the imaging element  4  on the imaging surface  4   a  of the imaging element  4 , produced when the lens frame  4002  is tilted. This enables prevention of a negative effect on the resolution, or a reduction in guaranteed resolution in the design, for an image or video that is captured by the imaging device  4000  that would be caused by misalignment of the axis of the imaging element  4  from the optical axis L 2  of the lens group on the imaging surface  4   a  of the imaging element  4  when the lens frame  4002  is tilted. 
         [0116]    In Example 2, described above, the explanation was for an example wherein a portion of the electronic components  43  were disposed on the periphery of a boundary part with the facing portion  45  in the extended portion  44  of the flexible printed circuit board  40 , but the arrangement of the electronic components  43  is not limited thereto. For example, the structure may be one wherein all of the electronic components  43  are disposed in the rearward region  41   b  of the facing location  45 . 
         [0117]    While in each of the examples described above the explanations were for examples wherein the imaging devices  1000 ,  2000 , and  3000  were provided with lens groups that were structured from two lenses  1 , the number of lenses  1  for structuring the lens group is not limited to 2. The lens group may be structured from a single lens  1 , or may be structured from three or more lenses  1 . 
         [0118]    While in the various examples set forth above the explanations were for examples wherein the imaging devices  1000 ,  2000 , and  3000  were each provided with at least one convex lens  1 , the number of lenses, the materials of the lenses, and the shapes of the lenses do not matter insofar as the desired physical properties (for example, refractive index, Abbe number, partial dispersion ratio, and coefficient of linear expansion), and durability, and the like, are produced. Moreover, the lens surface of the lens  1  may be formed from a spherical surface or a flat surface, or may be formed from an aspherical surface. The case wherein the lens surface is a spherical surface or a flat surface is preferred in that this makes lens processing and assembly adjustments easy, and prevents variation in optical performance due to processing or assembly adjustment tolerance error. Moreover, if the lens surface is an aspherical surface, the aspherical surface may be formed into an aspherical surface through a grinding process, a glass molding aspherical surface wherein glass is formed into an aspherical surface shape through molding, or a complex aspherical surface wherein resin is formed into an aspherical surface shape on the surface of the glass. Moreover, the lens surface may be a diffractive surface, and the lens may of a type with a distributed refractive index (a GRIN lens), or a plastic lens. 
         [0119]    Furthermore, in the lens surface of the lens  1 , the surface of the lens unit, as necessary, may be subjected to various types of treatments. Examples of such treatments include, for example, using a photocatalyst, or the like, to cause the surface portion to be hydrophilic in order to prevent clouding of the lens unit and to prevent formation of water droplets thereon. For example, when the camera explained in Example 4 is used, it may be, for example, a treatment such as a photocatalyst, or the like, to produce hydrophilia, to prevent fogging of the lens  1  and to prevent formation of water droplets, on locations that on the lens  1  that might be exposed to the outside. 
         [0120]    The lens frame  2  according to Example 1, described above, may be structured so that the lens will not come out of the lens frame through an external physical shock, or the like. Moreover, the shape of the lens frame  2  may be a round cylinder, may be a polygonal cylindrical body, a closed-bottom round cylinder, a closed-bottom polygonal cylindrical body, or the like. 
         [0121]    While in Example 1, described above, the explanation was for an example wherein the lens frame  2  was pressed against the imaging element  4  by a coil compression spring  6 , the lens frame  2  may be pressed against the imaging element  4  through, for example, a leaf spring or some other elastic member instead. Conversely, the structure may be one wherein the lens frame  2  is held against the imaging element  4  through a method such as thermocompression bonding or a method that uses an adhesive agent. 
         [0122]    Moreover, if necessary, the imaging element  4  that is provided in the imaging device  1000 ,  2000 , or  3000  of an example described above may include another member, such as, for example, a covering member such as a cover glass. Note that in the Specification and Patent Claims in the present example, the term “imaging element” is used not just for an imaging element that does not include other members, such as a covering member, but also means imaging elements that include other members, such as covering members. 
         [0123]    The imaging devices  1000 ,  2000 , and  3000  in the various examples set forth above, may be provided not just with a lens  1 , but, if necessary, members for preventing ghosting of the image that is imaged through the imaging device, or members for adjusting the cumulative tolerance of the lens unit in the optical axial direction (the thickness of the lens unit in the optical axial direction), waterproofing members for waterproofing, and IR-cut filters. 
         [0124]    While in Example 4, described above, the explanation was for an example of a camera  100  that incorporates any of the imaging devices  1000 ,  2000 , or  3000  according to Examples 1 through 3, described above, the optical device that incorporates the imaging device  1000 ,  2000 , or  3000  is not limited to being a camera. For example, it may be an electronic device such as a mobile telephone, a tablet terminal, a personal computer, or the like, wherein the imaging device  1000 ,  2000 , or  3000  is installed. It may instead be a vehicle wherein the imaging device  1000 ,  2000 , or  3000  is installed. 
         [0125]    The present invention may be embodied and modified in a variety of ways without deviating from the spirit or intent of the present invention, as broadly defined. Moreover, the examples set forth above are to explain this invention, and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the examples. Moreover, various modifications carried out within the scope of meaning of the invention within the claims or equivalents thereto are considered to be within the scope of the present invention.