Lens unit and camera unit having same

Abstract

The maintainability of a lens unit and a camera unit is improved, and the waterproof performance is stabilized. The technical problem is solved by a lens unit and a camera unit provided with the lens unit. The lens unit is provided with: a first lens as a lens; a cylindrical lens holder that holds the first lens; and an O-ring as a sealing member, the first lens being fixed to the lens holder by a fixing mechanism using a threaded structure, the O-ring being sandwiched between the first lens and the lens holder in an optical axis direction.

Description

Technical Field

[0001] The present invention relates to a lens unit and a camera unit including the lens unit, and more particularly to a technique for fixing a lens to a support body such as a lens holder. Background Art

[0002] Patent Document 1 listed below discloses a lens unit in which a lens is fixed to a lens holder by heating and pressurizing a resin claw or protrusion to plastically deform the claw or protrusion. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-210334 Summary of the invention

[0004] Technical problem to be solved by the invention When the lens is fixed to the lens holder by thermally deforming the resin claws or the like as in the lens unit of Patent Document 1, the claws or the like are inevitably damaged when the lens is removed after fixing. That is, the lens fixed to the lens holder cannot be replaced afterwards.

[0005] In addition, if the lens is a lens that presses the O-ring in the optical axis direction, the lens may float due to the repulsive force of the O-ring before the claws deformed by heat cool and solidify. This floating reduces the flattening rate of the O-ring and may damage the waterproof performance of the lens unit.

[0006] In view of the above problems, the technical problem to be solved by the present invention is to improve the maintainability and serviceability of the lens unit and the camera unit and to stabilize their waterproof performance. Technical solutions adopted to solve technical problems

[0007] In order to solve the above-mentioned technical problems, the main purpose of the lens unit of the present invention is to include: a first lens as a lens; a cylindrical lens holding frame that holds the first lens; and an O-ring as a sealing component, wherein the first lens is fixed to the lens holding frame by a fixing mechanism using a threaded structure, and the O-ring is clamped by the first lens and the lens holding frame in the optical axis direction.

[0008] By fixing the lens holder and the first lens using a fixing mechanism with a screw structure, the first lens can be removed without damaging the lens holder even after fixing. In addition, the first lens is prevented from floating due to the repulsive force of the O-ring.

[0009] In this case, the first lens is preferably a plastic lens, and the fixing mechanism is composed of an external thread formed on the outer peripheral surface of the first lens and an internal thread formed on the inner peripheral surface of the lens holder. By using a plastic lens, an external thread with high molding accuracy can be formed on the first lens itself, and a fixing mechanism using a threaded structure can be realized with a simple structure.

[0010] In addition, at this time, it is preferred that the first lens and the lens holder have an optical axis direction positioning portion that is different from the fixing mechanism, abuts against each other in the optical axis direction and determines the position of the first lens relative to the optical axis direction of the lens holder. When the direction orthogonal to the optical axis direction is referred to as the radial direction, the first lens has a flange portion that extends radially outward from the position of the external thread at a position closer to the object side than the external thread, and the optical axis direction positioning portion is composed of the image side surface of the flange portion and the surface of the lens holder opposite thereto. In the case of fixing the lens by using a fixing mechanism with a threaded structure, a corresponding clearance (tooth gap) is required in order to smoothly screw the thread. This clearance may cause the shaking of the lens in the optical axis direction or the individual differences and disturbances in the lens position. By providing the optical axis direction positioning portion separately from the threaded structure, this disadvantage can be suppressed and the optical quality of the lens unit can be stabilized.

[0011] In addition, at this time, it is preferred that the first lens and the lens holder have a radial positioning portion that is different from the fixing mechanism, abuts against each other in the radial direction and determines the radial position of the first lens relative to the lens holder, and the first lens has a cylindrical or columnar fitting portion at a position closer to the image side than the external thread, and the radial positioning portion is composed of the outer peripheral surface of the fitting portion and the surface of the lens holder opposite thereto. In the case of fixing the lens by using a fixing mechanism with a threaded structure, a corresponding clearance (difference in effective diameter) is required in order to allow the thread to be screwed smoothly. This clearance may cause the shaking of the lens in the radial direction or the individual differences and disorder of the lens position. By providing the radial positioning portion separately from the threaded structure, this disadvantage can be suppressed and the optical quality of the lens unit can be stabilized. In addition, it is also possible that the first lens has a cylindrical or columnar fitting portion at a position closer to the object side than the external thread, and the radial positioning portion is composed of the outer peripheral surface of the fitting portion and the surface of the lens holder opposite thereto.

[0012] In addition, the outer peripheral surface of the fitting portion is preferably arranged at a position radially outward of the position of the O-ring. The external thread of the first lens is screwed with the inner peripheral surface of the lens holder, and therefore is usually arranged at a position (radially) outward of the O-ring. In order to eliminate the disadvantages caused by the play of the thread structure, it is appropriate for the fitting portion to be continuously arranged with the external thread, that is, to be arranged at a position outward of the position of the O-ring. In addition, in this way, a part of the forming surface of the external thread can be processed to provide a radial positioning portion, thereby reducing the complexity of the structure caused by having a radial positioning portion.

[0013] In addition, in the lens unit of the present invention, the first lens may be a plastic lens having a cylindrical portion, and the fixing mechanism may be composed of an external thread formed on the outer peripheral surface of the lens holder and an internal thread formed on the inner peripheral surface of the cylindrical portion. The effect of providing a thread structure in the first lens itself by using a plastic lens is as described above.

[0014] At this time, it is preferred that the first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, an annular groove portion is formed on the image side surface of the first lens, the internal thread is formed on the radially outer wall surface of the groove portion, and the optical axis direction positioning portion is composed of the bottom surface of the groove portion and the surface of the lens holder opposite thereto. The effect obtained by providing the optical axis direction positioning portion separately from the thread structure is as described above.

[0015] In addition, at this time, it is preferred that the first lens and the lens holder have a radial positioning portion different from the fixing mechanism, and the radial positioning portion is composed of a radial inner wall surface of the groove portion and a surface of the lens holder opposite thereto. The effect obtained by providing the radial positioning portion separately from the thread structure is as described above.

[0016] In addition, in the lens unit of the present invention, it is preferred that a concave portion, a convex portion, a notch, a knurling, a serration, a spline or other concave-convex portion that allows a fixture, a tool or a finger to engage in a circumferential direction is provided on the outer surface of the first lens at a position that is irrelevant to its optical performance. Thus, the replacement of the first lens becomes easy. In particular, in the case where the lens unit is ultra-small or ultra-large, and it is difficult to rotate the first lens without using a certain tool, the existence of such a concave-convex portion can achieve the purpose of replacing the first lens.

[0017] In addition, in the lens unit of the present invention, it is also possible that the first lens has a lens portion that determines its optical performance and a non-lens portion that extends radially outward from the lens portion. A plurality of holes are formed in the non-lens portion, and the first lens is fixed to the lens holder by passing screws through the holes in the non-lens portion. The effect of fixing the lens holder and the first lens using a fixing mechanism with a threaded structure is as described above. In addition, the holes in the non-lens portion can also be holes without threaded grooves (so-called loose holes (Japanese: バカ穴), drilled holes), and it can also be applied to glass lenses where it is difficult to form threads.

[0018] At this time, it is preferable that the first lens and the lens holder have a positioning portion in the optical axis direction different from the fixing mechanism, and the positioning portion in the optical axis direction is constituted by the image side surface of the non-lens portion and the surface of the lens holder opposite thereto. The effect obtained by separately providing the positioning portion in the optical axis direction from the threaded structure is as described above.

[0019] In addition, at this time, it is preferable that the first lens and the lens holder have a radial positioning portion different from the fixing mechanism. The first lens has a cylindrical or columnar fitting portion disposed at a position radially inward of the O-ring, and the radial positioning portion is constituted by the outer peripheral surface of the fitting portion and the surface of the lens holder opposite thereto. The effect obtained by separately providing the radial positioning portion from the threaded structure is as described above.

[0020] Thus, in the lens unit of the present invention, it is preferable that the first lens and the lens holder have a positioning portion in the optical axis direction different from the fixing mechanism, which abuts against each other in the optical axis direction and determines the position of the first lens relative to the lens holder in the optical axis direction. In addition, it is preferable to have a radial positioning portion different from the fixing mechanism, which abuts against each other in the radial direction and determines the radial position of the first lens relative to the lens holder.

[0021] In addition, in the lens unit of the present invention, it is also possible that the first lens and the lens holder are joined by an adhesive. In addition to using a fixing mechanism with a threaded structure, by joining them with an adhesive, loosening of the threads after fixing can be prevented.

[0022] At this time, it is preferable that the adhesive is a disassembly adhesive that can be disassembled by performing a specific treatment on the joint portion after bonding. Thereby, it is possible to take into account both prevention of loosening of the threads and ease of replacement of the first lens.

[0023] In addition, in the lens unit of the present invention, it is preferred to have a plurality of lenses arranged along the optical axis direction, the first lens is a lens arranged at a position closest to the object side among the plurality of lenses, and a lens arranged closer to the image side than the first lens is fixed to the lens holder by riveting. By selecting the best fixing method according to the properties of each lens and the use environment, the optical quality, maintainability, maintenance, assembly, cost efficiency, etc. of the lens unit can be improved in a well-balanced manner.

[0024] In addition, in order to solve the above-mentioned technical problems, the camera unit of the present invention comprises: a plurality of lenses arranged along the optical axis direction; a cylindrical lens holder; an O-ring as a sealing component; a camera module; and a camera housing that accommodates the camera module, wherein when the lens closest to the object side among the plurality of lenses is referred to as the first lens, the lens holder holds a lens that is arranged closer to the image side than the first lens, the first lens having a lens portion that determines the optical performance of the first lens and a non-lens portion that extends radially outward from the lens portion, the non-lens portion having a plurality of holes, the first lens being fixed to the object side surface of the camera housing by passing a screw through the hole of the non-lens portion, and the O-ring being clamped in the optical axis direction by the first lens and the camera housing or the lens holder.

[0025] The effect of fixing the first lens by using a fixing mechanism with a threaded structure is as described above. In addition, the effect obtained by fixing the non-lens portion of the first lens by screws is also as described above. Here, in order to fix the non-lens portion of the first lens with screws, the non-lens portion requires a corresponding area. That is, the disadvantage of a large-scale unit may occur. In the present invention, the first lens is not fixed to the lens holder but is directly fixed to the camera housing, thereby achieving the effect of using a fixing mechanism with a threaded structure and alleviating the above-mentioned disadvantages. Effects of the Invention

[0026] As described above, according to the present invention, the maintainability and serviceability of the lens unit and the camera unit are improved, and the waterproof performance thereof is stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a side cross-sectional view showing the internal structure of the lens unit according to the first embodiment. Figure 2 yes Figure 1 An enlarged view of the portion surrounded by the dot-dash line. Figure 3 It is a perspective view showing the structure of the cutout portion of the first lens. Figure 4 This is a partially enlarged view showing a modified example of the lens unit according to the first embodiment. Figure 5It is a side cross-sectional view showing the internal structure of the lens unit according to the second embodiment. Figure 6 yes Figure 5 An enlarged view of the portion surrounded by the dot-dash line. Figure 7 It is a side cross-sectional view showing the internal structure of the camera unit according to the third embodiment. Figure 8 yes Figure 7 An enlarged view of the portion surrounded by the dot-dash line. Fig. 9 is a top view of the lens unit. Fig.10 (a) and (b) are a side cross-sectional view showing the internal structure of a lens unit according to a fourth embodiment. Fig.11 It is a side view showing a modification of the lens unit according to the fourth embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the lens unit and the camera unit according to the present invention will be described with reference to the drawings.

[0029] The lens unit and the camera unit described below are characterized by a method for fixing the lens, particularly the lens disposed closest to the object. Specifically, by fixing the lens using a fixing mechanism using a screw structure or a fixing mechanism using an elastically deformable arm and a hook, the lens can be removed after fixing, and positional displacement of the lens caused by the reaction force of the O-ring can be prevented. These features and their accompanying features are described below based on various embodiments.

[0030] <First embodiment> (Overall structure) The lens unit U1 of this embodiment is a general-purpose small lens unit used in various imaging devices. Figure 1 1 is a side cross-sectional view showing the internal structure of the lens unit U1 according to the first embodiment. Figure 1 The overall structure of the lens unit U1 will be described.

[0031] Figure 1 The double-dotted dashed line L1-L2 shown shows the optical axis of the lens unit U1, the L1 side is the object side (subject side), and the L2 side is the image side. For the convenience of explanation according to the drawings, the L1 side is sometimes referred to as "upper" and the L2 side is sometimes referred to as "lower". In addition, the direction orthogonal to the optical axis direction is referred to as "radial", and for convenience, it is sometimes referred to as "horizontal". In addition, in the following description, "circumferential direction" refers to the direction around the optical axis.

[0032] The lens unit U1 includes: five lenses arranged along the optical axis L1-L2, namely, the first lens 10 to the fifth lens 95; and the lens holder 20 that holds these lenses. The light shielding plate 97 is provided between the second lens 92 and the third lens 93, and the aperture 98 is provided between the third lens 93 and the fourth lens 94. In addition, an optical filter 96 is arranged on the end surface of the lens holder 20 closest to the image side, and the optical filter 96 is fixed to the end surface of the lens holder 20 by riveting through a resin claw 961. In addition, the second lens 92 is fixed by riveting through a resin annular rib 921 provided on the lens holder 20.

[0033] All lenses in this embodiment are plastic lenses, and the fifth lens 95 and the fourth lens 94 on the most image side form a cemented lens. The number and type of lenses held by the lens holder 20 are not limited to the structure of this embodiment and can be appropriately changed according to the purpose of the lens unit and the subject.

[0034] The lens holder 20 is a lens barrel / lens frame that holds these lenses, and has a cylindrical small diameter portion 21 and a large diameter portion 22 having an inner diameter larger than the small diameter portion 21. The large diameter portion 22 and the small diameter portion 21 are connected by a circular ring-shaped flat surface portion that extends horizontally from the upper end of the small diameter portion 21. The first lens 10 is held in the large diameter portion 22, and the second lens 92 to the fifth lens 95, the light shielding plate 97, and the aperture 98 are held in the small diameter portion 21. The structure of the lens holder 20 is not limited to the present embodiment, and any structure of the lens holder may be used as long as it has a threaded structure or a hook structure described later.

[0035] An O-ring 91 is placed on the plane portion connecting the small diameter portion 21 and the large diameter portion 22 of the lens holder 20. The O-ring 91 is a sealing member that prevents water from entering the lens unit U1 from the object side. The O-ring 91 is sandwiched between the plane portion on which it is placed and the lower surface of the first lens 10, and is compressed in the optical axis direction.

[0036] (Fixed structure of the first lens) Figure 2 yes Figure 1 The enlarged view of the portion surrounded by the dashed line is a view showing the details of the fixing structure of the first lens 10. Figure 2 , the fixing structure of the first lens 10 in this embodiment is described.

[0037] The first lens 10 is a plastic lens having negative optical power. Figure 1) is engraved with an external thread 111 on its outer circumferential surface. A flange portion 12 in the shape of an annulus is provided on the external thread 111 and extends radially outward from the external thread 111. A cylindrical fitting portion 13a, which is a lens-side fitting portion, is provided below the external thread 111 and protrudes downward.

[0038] The large diameter portion 22 of the lens holder 20 is a cylindrical portion. An internal thread 221 corresponding to the external thread 111 of the first lens 10 is engraved on the inner circumference of the large diameter portion 22. A holder side fitting portion 23a is provided below the internal thread 221. The holder side fitting portion 23a is an inner circumference extending radially inward from the top of the thread teeth of the internal thread 221.

[0039] like Figure 2 As shown, the first lens 10 is fixed to the lens holder 20 by a fixing mechanism using a threaded structure. Specifically, the first lens 10 is fixed to the lens holder 20 by screwing its external thread 111 with the internal thread 221 of the lens holder 20. As described above, the first lens 10 of the present embodiment is a plastic lens. By using a plastic lens, it is possible to form an external thread 111 with high molding accuracy on the first lens 10 itself, and realize a fixing mechanism using a threaded structure with a simple structure. Moreover, by screwing the lens holder 20 and the first lens 10, it is possible to remove the lens holder 20 without damaging it even after the first lens 10 is fixed. In addition, the lifting of the first lens 10 due to the repulsive force of the O-ring 91 is also prevented. Plastic lenses are cheaper than glass lenses, but are less hard than glass lenses, and are therefore easily damaged. According to the lens unit U1, when the performance of the first lens 10 is impaired due to damage, the first lens 10 can be easily replaced.

[0040] In addition to the above-mentioned threaded structure, the first lens 10 and the lens holder 20 of this embodiment further have an optical axis direction positioning portion, which abuts against each other in the optical axis direction to determine the position of the first lens 10 in the optical axis direction relative to the lens holder 20. The optical axis direction positioning portion of this embodiment is composed of the lower surface 12a of the flange portion 12 of the first lens 10 and the upper surface 22a of the large diameter portion 22a opposite thereto.

[0041] In addition, the first lens 10 and the lens holder 20 of the present embodiment have radial positioning portions in addition to the above-mentioned threaded structure, and the radial positioning portions abut against each other in the radial direction to determine the radial position of the first lens 10 relative to the lens holder 20. The radial positioning portion of the present embodiment is composed of the outer peripheral surface of the lens-side fitting portion 13a of the first lens 10 and the holder-side fitting portion 23a of the large-diameter portion 22 opposite thereto.

[0042] When the lens is fixed by a fixing mechanism using a threaded structure, a corresponding clearance (tooth gap or difference in effective diameter) is required to make the thread smoothly screwed. This clearance may cause the shaking of the lens in the optical axis direction and radial direction, and the individual differences and disorder of the lens position. In addition to the threaded structure, the lens unit U1 of this embodiment also has an optical axis direction positioning part and a radial positioning part, thereby suppressing such disadvantages and stabilizing the optical quality of the lens unit U1.

[0043] In addition, if Figure 1 As shown, in the lens unit U1, the first lens 10 and the lens holding frame 20 are also bonded by the adhesive 99. In addition to the fixing mechanism using the screw structure, by bonding them with the adhesive 99, loosening of the screw after fixing is prevented.

[0044] Here, the adhesive 99 of this embodiment is a thermoplastic adhesive, and after bonding, the bonding can be released by reheating the joint. In this way, the loosening of the thread and the ease of replacement of the first lens 10 are achieved at the same time. In addition, the adhesive that can be used is not limited to thermoplastic adhesives, as long as it is an adhesive that can be released by performing specific treatment on its joint after bonding (so-called disassembly adhesive). Alternatively, it can also be an adhesive that has a degree of bonding strength that can prevent the thread from loosening, and if it is desired to peel it off, it can be peeled off without damaging the first lens 10 and the lens holder 20. In addition, the bonding of the adhesive 99 can also be adopted in the second to fourth embodiments later.

[0045] (First lens replacement auxiliary structure) Figure 3 1 is a perspective view showing the structure of the cutout portion 14 of the first lens 10. Figure 3 As shown, the first lens 10 has three cutouts 14 arranged at equal intervals in the circumferential direction on the outer edge of the flange 12 thereof.

[0046] As described above, the lens unit U1 of the present embodiment is a small lens unit, and its diameter size is about 15 to 16 mm. In a small lens unit such as the lens unit U1, or conversely, in an extra-large lens unit, it may be difficult to replace the first lens 10 with fingers. In the lens unit U1, the first lens 10 has a cutout portion 14, so that the first lens 10 can be easily and safely replaced using a special tool. In addition, the shape and structure of the cutout portion 14 are not limited to the form of the lens unit U1. The cutout portion 14 can be provided in a portion that is not related to the optical performance of the lens, such as a concave portion, a convex portion, a knurling, a serration, a spline, or other concave-convex portion that allows a fixture, a tool, or a finger to engage in a circumferential direction. In the case where it is difficult to rotate the first lens 10 without using any tool, only the existence of such a concave-convex portion can achieve the purpose of replacing the first lens 10.

[0047] (Variation Example) Figure 4 1 is a partial enlarged view showing a modification of the lens unit U1. The modification described below is mainly a modification of the lens-side fitting portion 13a and the holder-side fitting portion 23a constituting the radial positioning portion of the lens unit U1.

[0048] like Figure 2 As shown, the lens-side fitting portion 13a of the above embodiment is formed from the main body portion 11 of the first lens 10 (see Figure 1 ) is a cylindrical portion whose lower end further protrudes downward. Figure 4 In the modified example (a), the outer diameter of the lower end of the main body 11 is made smaller than the diameter of the bottom of the thread groove of the external thread 111, and the lens side fitting portion 13b is provided on the main body 11 itself. On the other hand, the lens holder 20 side is substantially the same as the holder side fitting portion 23a of the above-mentioned embodiment, and a holder side fitting portion 23b is provided below the internal thread 221 and extends radially inwardly from the top of the thread teeth of the internal thread 221.

[0049] exist Figure 4 In the modified example (b), the outer diameter of the upper end of the main body 11 is made larger than the diameter of the top of the thread of the external thread 111, and the lens side fitting portion 13c is also provided on the main body 11 itself. On the lens holder 20, a holder side fitting portion 23c is provided on the internal thread 221, and the holder side fitting portion 23c is an inner peripheral surface that extends radially outward from the bottom of the thread groove of the internal thread 221.

[0050] In the above-mentioned embodiment and the above-mentioned modification, the outer peripheral surfaces of the lens-side fitting parts 13a, 13b, and 13c are all arranged at positions radially outward from the position of the O-ring 91. The external thread 111 of the first lens 10 is screwed with the inner peripheral surface of the lens holder 20, and therefore, it is usually arranged at a position (radially) outward from the O-ring 91. From the purpose of eliminating the disadvantages caused by the clearance of the thread structure, it is appropriate for the lens-side fitting parts 13a, 13b, and 13c to be provided continuously with the external thread 111, that is, to be arranged at a position outward from the position of the O-ring 91. In addition, by doing so, a radial positioning part can be provided by processing a part of the forming surface of the external thread 111 (that is, the outer peripheral surface of the main body 11) or its vicinity, thereby reducing the complexity of the structure caused by having a radial positioning part.

[0051] <Second embodiment> Figure 5 1 is a side cross-sectional view showing the internal structure of the lens unit U2 according to the second embodiment. Figure 6 yes Figure 5 The enlarged view of the portion surrounded by the dashed line is a view showing the details of the fixing structure of the first lens 15. Figure 5 and Figure 6 The characteristics of the lens unit U2 are described. In addition, in the following description, for the same structure as the first embodiment, the same symbols as the previous embodiment are marked, and the detailed description is omitted. In addition, the structure with the same name as the structure of the first embodiment can be considered as a positioning structure equivalent to the structure of the first embodiment. The same applies to the description of the third embodiment and later.

[0052] In the lens unit U1 of the first embodiment, an external thread 111 is provided on the first lens 10 and an internal thread 221 is provided on the lens holding frame 20 , but in the lens unit U2 of this embodiment, on the contrary, an internal thread 17 is provided on the first lens 15 and an external thread 28 is provided on the lens holding frame 25 .

[0053] The first lens 15 is formed with an annular groove 16 on its lower surface. The groove 16 is composed of a bottom surface 16a, an outer wall surface 16b as a radially outer wall surface, and an inner wall surface 16c as a radially inner wall surface. An internal thread 17 is formed on the outer wall surface 16b of the groove 16, and an external thread 28 is formed on the outer peripheral surface 27b of the large diameter portion 27 of the lens holder 25. The effect of providing a thread structure on the first lens itself by using a plastic lens is the same as that described in the first embodiment. In addition, the lens unit U2 can also have the same cutout portion 14 as the lens unit U1.

[0054] The optical axis direction positioning portion of the lens unit U2 is composed of the bottom surface 16a of the groove portion 16 and the upper surface 27a of the large diameter portion 27 opposite thereto. In addition, the radial direction positioning portion of the lens unit U2 is composed of the inner wall surface 16c of the groove portion 16 and the inner peripheral surface 27c of the large diameter portion 27 opposite thereto. The effect obtained by providing the optical axis direction positioning portion and the radial direction positioning portion separately from the thread structure is the same as that described in the first embodiment.

[0055] In addition, in the present embodiment, in order to set the radial positioning portion using the inner circumferential surface 27c of the large diameter portion 27, the groove portion 16 is adopted. However, when the radial positioning portion is not required, or when the radial positioning portion is set using a method different from that of the present embodiment, the groove portion 16 may not be provided, and for example, only a simple cylindrical portion (equivalent to the structure of the outer circumferential surface of the first lens 15 and the inner wall surface 16b of the groove portion 16) may be provided on the first lens 15, and an internal thread 17 may be formed on its inner circumferential surface.

[0056] <Third Embodiment> Figure 7 It is a side cross-sectional view showing the internal structure of the camera unit U3 according to the third embodiment. Figure 8 yes Figure 7The enlarged view of the portion surrounded by the dashed line is a view showing details of the fixing structure of the first lens 30 . Fig. 9 is a top view of the camera unit U3. Figures 7 to 9 The features of the camera unit U3 are described.

[0057] The camera unit U3 is a small camera unit mainly used as a vehicle-mounted camera. The camera unit U3 has a built-in camera module 46, and has a cylindrical lens holder 45 that holds the second lens 92 to the fifth lens 95, the light shielding plate 97, the aperture 98, and the optical filter 96. These components are stored in the camera housing 40 that is the housing of the camera unit U3.

[0058] The first lens 30 of the camera unit U3 is a plastic lens. The first lens 30 has a lens portion 31 that determines its optical performance and a main body portion 311 extending from the lens portion 31 (see Figure 7 ) The non-lens portion 32 extends radially outward. Fig. 9 As shown, the planar shape of the non-lens portion 32 is a rounded rectangle, and its four corners are fixed by screws 49. Figure 8 As shown, the first lens 30 is fixed to the upper surface of the camera housing 40 by inserting a screw 49 into the hole 321 of the non-lens portion 32 and tightening the screw 49 into the threaded hole 41 of the camera housing 40. The hole 321 of the non-lens portion 32 is a hole without a thread groove (so-called loose hole, drilled hole). Therefore, the first lens 30 can be a glass lens. The O-ring 91 is sandwiched between the lower surface 32a of the non-lens portion 32 and the upper surface of the camera housing 40 (the O-ring mounting surface 43 described later) and is compressed in the optical axis direction. The effect of fixing the first lens 30 to the camera housing 40 by using a fixing mechanism with a threaded structure is the same as that described in the first embodiment.

[0059] like Figure 8 As shown, the upper surface of the camera housing 40 is formed so that its surface position decreases in a step-like manner from the outer edge of the camera housing 40 toward the center (lens holder portion 45). On the upper surface of the camera housing 40, from the outer edge side to the center side, there are formed in order: a lens mounting surface 42 whose surface position is recessed in the same shape as the first lens 30 (non-lens portion 32); an O-ring mounting surface 43 on which an O-ring 91 is arranged; and an upper surface 45a of the lens holder portion 45.

[0060] like Figure 8As shown in FIG. 1 , the optical axis direction positioning portion of the camera unit U3 is composed of the lower surface 32a of the non-lens portion 32 and the lens mounting surface 42 of the camera housing 40 that is opposite to the lower surface 32a. The radial positioning portion of the camera unit U3 is composed of the lens side fitting portion 33 of the first lens 30 and the housing side fitting portion 44 of the camera housing 40, and the housing side fitting portion 44 is opposite to the lens side fitting portion 33. The lens side fitting portion 33 is a main body portion 311 of the first lens 30 (see FIG. 1 ). Figure 7 ). The housing side fitting portion 44 is a vertical surface between the O-ring mounting surface 43 and the upper surface 45a of the lens holder. The effect obtained by providing the optical axis direction positioning portion and the radial positioning portion separately from the thread structure is the same as that described in the first embodiment.

[0061] Here, in order to fix the non-lens portion 32 of the first lens 30 with the screw 49, the non-lens portion 32 requires a corresponding area. That is, the disadvantage of enlarging the unit may occur. In the camera unit U3, the first lens 30 is directly fixed to the camera housing 40 instead of being fixed to the lens holder 45, thereby obtaining the effect of the fixing mechanism using a threaded structure while reducing the above-mentioned disadvantages. In addition, when the enlargement of the unit does not occur, or when the enlargement of the unit is not a problem, the lens holder portion 45 can also be made larger, and the first lens 30 can be screwed to the lens holder portion 45.

[0062] <Fourth embodiment>> Fig.10 1 and 1 are a side cross-sectional view (a) and a side view (b) showing the internal structure of the lens unit U4 according to the fourth embodiment. Fig.10 The features of the lens unit U4 will be described.

[0063] In the above-mentioned embodiments, the structure of fixing the first lens to the lens holder or the camera housing by using a fixing mechanism with a screw structure is described, but the fixing mechanism that can remove the fixed lens and prevent the positional displacement of the lens caused by the repulsive force of the O-ring is not limited to the unit using a screw structure. In the lens unit U4 described below, this problem is solved by using an elastically deformable arm and a hook instead of a fixing mechanism with a screw structure.

[0064] The first lens 50 of the lens unit U4 is a plastic lens, and an annular groove 51 is formed on its lower surface. In addition, a plurality of elastic arms 52 extend downward from the outer peripheral portion (the portion radially outward of the groove 51) of the first lens 50. In this embodiment, three elastic arms 52 are arranged at equal intervals in the circumferential direction. A hook 521 is provided at the lower end of each elastic arm 52, and the hook 521 engages with the lower surface 62a of the large diameter portion 62 of the lens holder 60.

[0065] In the lens unit U4, by using a plastic lens as the first lens 50, the first lens 50 and the elastic arm 52 can be integrally formed. Moreover, since the first lens 50 is fixed to the lens holder 60 by the hook 521 of the elastic arm 52, even after the first lens 50 is fixed, it is possible to remove it without damaging the lens holder 60. In addition, the first lens 50 is prevented from floating due to the repulsive force of the O-ring 91. In addition, when the performance of the first lens 50 is impaired due to damage, the first lens 50 can be easily and inexpensively replaced.

[0066] In addition, the position of the first lens 50 in the lens unit U4 in the optical axis direction is determined by the hook 521 of the elastic arm 52 and the lower surface 62a of the large diameter portion 62 (this is because the first lens 50 is always pushed to the object side by the repulsive force of the O-ring 91). In addition, the radial position of the first lens 50 is determined by the radial inner surface of the wall surface of the groove portion 51, that is, the inner wall surface 51c and the inner peripheral surface 62b of the large diameter portion 62 opposite thereto.

[0067] (Variation Example) Fig.11 1 is a side view showing a modified example of the lens unit U4. Fig.11 As shown, the elastic arm 52 and the hook 521 may be provided with a hook 63 on the lens holder 60 side, and a hole 531 for fitting and engaging with the hook 63 may be provided on the elastic arm 52 .

[0068] <Other> Additionally, the present technology can adopt the following configurations. (1) A lens unit comprising: a first lens, which is a lens; a cylindrical lens holding frame that holds the first lens; and O-ring, which is a sealing component, The first lens is fixed to the lens holder by using a fixing mechanism with a thread structure. The O-ring is sandwiched by the first lens and the lens holding frame in the optical axis direction. (2) The lens unit according to (1), wherein: The first lens is a plastic lens, The fixing mechanism is composed of an external thread formed on the outer peripheral surface of the first lens and an internal thread formed on the inner peripheral surface of the lens holding frame. (3) The lens unit according to (2), wherein: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. The direction perpendicular to the optical axis is called the radial direction. The first lens has a flange portion extending radially outward from the position of the external thread at a position closer to the object side than the external thread. The optical axis direction positioning portion is composed of the image side surface of the flange portion and a surface of the lens holding frame facing the image side surface. (4) The lens unit according to (2) or (3), wherein: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have radial positioning parts different from the fixing mechanism, the radial positioning parts abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion at a position closer to the image side than the external thread. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface of the fitting portion. (5) The lens unit according to (2) or (3), wherein: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have radial positioning parts different from the fixing mechanism, the radial positioning parts abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion at a position closer to the object side than the external thread. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface of the fitting portion. (6) The lens unit according to (4) or (5), wherein: The outer peripheral surface of the fitting portion is arranged radially outward of the O-ring. (7) The lens unit according to (1), wherein: The first lens is a plastic lens having a cylindrical portion, The fixing mechanism is composed of an external thread formed on the outer peripheral surface of the lens holding frame and an internal thread formed on the inner peripheral surface of the cylindrical portion. (8) The lens unit according to (7), wherein: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. An annular groove is formed on the image side surface of the first lens. The direction perpendicular to the optical axis is called the radial direction. The internal thread is formed on the radially outer wall surface of the groove portion. The optical axis direction positioning portion is composed of a bottom surface of the groove portion and a surface of the lens holding frame facing the bottom surface of the groove portion. (9) The lens unit according to (8), wherein: The first lens and the lens holder have radial positioning parts different from the fixing mechanism, the radial positioning parts abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The radial positioning portion is constituted by a radially inner wall surface of the groove portion and a surface of the lens holding frame facing the radially inner wall surface. (10) The lens unit according to any one of (1) to (9), wherein: On the outer surface of the first lens, a concave portion, a convex portion, a cut, a knurling, a serration, a spline, or other concave-convex portions that enable a clamp, a tool or a finger to engage in a circumferential direction are provided at a position irrelevant to its optical performance. (11) The lens unit according to (1), wherein: The direction perpendicular to the optical axis is called the radial direction. The first lens has: a lens portion that determines the optical performance of the first lens; and a non-lens portion extending radially outward from the lens portion, A plurality of holes are formed in the non-lens portion, The first lens is fixed to the lens holding frame by passing a screw through the hole of the non-lens portion. (12) The lens unit according to (11), wherein: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. The optical axis direction positioning portion is composed of the image-side surface of the non-lens portion and a surface of the lens holding frame facing the image-side surface. (13) The lens unit according to (11) or (12), wherein: The first lens and the lens holder have radial positioning parts different from the fixing mechanism, the radial positioning parts abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion disposed radially inward of the O-ring. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface of the fitting portion. (14) The lens unit according to any one of (1) to (13), wherein: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. (15) The lens unit according to any one of (1) to (14), wherein: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have radial positioning parts different from the fixing mechanism, and the radial positioning parts abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder. (16) The lens unit according to any one of (1) to (15), wherein: The first lens and the lens holding frame are bonded together by an adhesive. (17) The lens unit according to (16), wherein: The adhesive is a disassembly adhesive that can be released by subjecting the bonding portion thereof to a specific treatment after bonding. (18) The lens unit according to any one of (1) to (17), wherein: It has a plurality of lenses arranged along the optical axis. The first lens is a lens disposed closest to the object among the plurality of lenses. A lens disposed on the image side of the first lens is fixed to the lens holding frame by caulking. (19) A camera unit comprising: A plurality of lenses arranged along the optical axis; A cylindrical lens holder; O-ring as a sealing component; camera module; and a camera housing for housing the camera module; When the lens closest to the object among the plurality of lenses is referred to as the first lens, The lens holding frame holds the lens disposed on the image side relative to the first lens. The direction perpendicular to the optical axis is called the radial direction. The first lens has: a lens portion that determines the optical performance of the first lens; and a non-lens portion extending radially outward from the lens portion, A plurality of holes are formed in the non-lens portion, The first lens is fixed to the surface of the object side of the camera housing by passing a screw through the hole of the non-lens portion, The O-ring is sandwiched by the first lens and the camera housing or the lens holding frame in the optical axis direction.

[0069] As mentioned above, although embodiment of this invention was demonstrated in detail, this invention is not limited to the said embodiment at all, Various changes are possible within the range which does not deviate from the summary of this invention. Explanation of symbols

[0070] U1: lens unit, 10: first lens, 11: main body, 111: external thread (fixing mechanism), 12: flange, 12a: lower surface (optical axis direction positioning portion), 13a~13c: lens side fitting portion (radial positioning portion), 14: cutout, 20: lens holder, 21: small diameter portion, 22: large diameter portion, 221: internal thread (fixing mechanism), 22a: upper surface (optical axis direction positioning portion), 23a~23c: holder side fitting portion (radial positioning portion), U2: Lens unit, 15: First lens, 16: Groove, 16a: Bottom surface (radial positioning portion), 16b: Outer wall surface, 16c: Inner wall surface (optical axis direction positioning portion), 17: Internal thread (fixing mechanism), 25: Lens holder, 27: Large diameter portion, 27a: Upper surface (optical axis direction positioning portion), 27b: Outer peripheral surface, 27c: Inner peripheral surface (radial positioning portion), 28: External thread (fixing mechanism), U3: Camera unit, 30: First lens, 31: Lens portion, 31 1: Main body, 32: Non-lens part, 32a: Image side (positioning part in the optical axis direction), 321: Hole, 33: Lens side fitting part (radial positioning part), 40: Camera housing, 41: Threaded hole (fixing mechanism), 42: Lens mounting surface (positioning part in the optical axis direction), 43: O-ring mounting surface, 44: Housing side fitting part (radial positioning part), 45: Lens holder, 45a: Upper surface, 46: Camera module, 49: Screw (fixing mechanism), U4: Lens unit, 5 0: first lens, 51: groove portion, 51c: inner wall surface, 52: elastic arm, 521: hook, 531: hook hole, 60: lens holder, 61: small diameter portion, 62: large diameter portion, 62a: bottom surface, 62b: inner peripheral surface, 63: hook, 91: O-ring, 92: second lens, 921: rivet portion, 93: third lens, 94: fourth lens, 95: fifth lens, 96: optical filter, 961: rivet portion, 97: shading plate, 98: aperture, 99: adhesive.

Claims

1. A lens unit, characterized in that: have: As the first lens of the lens; a cylindrical lens holding frame holding the first lens; and As a sealing component, the O-ring The first lens is fixed to the lens holder by using a fixing mechanism with a thread structure. The O-ring is sandwiched by the first lens and the lens holding frame in the optical axis direction.

2. The lens unit according to claim 1, characterized in that: The first lens is a plastic lens, The fixing mechanism is composed of an external thread formed on the outer peripheral surface of the first lens and an internal thread formed on the inner peripheral surface of the lens holding frame.

3. The lens unit according to claim 2, characterized in that: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions of the first lens and the lens holder abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. The direction perpendicular to the optical axis is called the radial direction. The first lens has a flange portion extending radially outward from the position of the external thread at a position closer to the object side than the external thread. The optical axis direction positioning portion is composed of an image side surface of the flange portion and a surface of the lens holding frame that faces the image side surface.

4. The lens unit according to claim 2, characterized in that: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have a radial positioning portion different from the fixing mechanism, the radial positioning portions of the first lens and the lens holder abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion at a position closer to the image side than the external thread. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface.

5. The lens unit according to claim 2, characterized in that: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have a radial positioning portion different from the fixing mechanism, the radial positioning portions of the first lens and the lens holder abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion at a position closer to the object side than the external thread. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface.

6. The lens unit according to claim 4 or 5, characterized in that: The outer peripheral surface of the fitting portion is arranged radially outward of the O-ring.

7. The lens unit according to claim 1, characterized in that: The first lens is a plastic lens having a cylindrical portion, The fixing mechanism is composed of an external thread formed on the outer peripheral surface of the lens holding frame and an internal thread formed on the inner peripheral surface of the cylindrical portion.

8. The lens unit according to claim 7, characterized in that: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions of the first lens and the lens holder abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. An annular groove is formed on the image side surface of the first lens. The direction perpendicular to the optical axis is called the radial direction. The internal thread is formed on the radially outer wall surface of the groove portion. The optical axis direction positioning portion is composed of a bottom surface of the groove portion and a surface of the lens holding frame facing the bottom surface.

9. The lens unit according to claim 8, characterized in that: The first lens and the lens holder have a radial positioning portion different from the fixing mechanism, the radial positioning portions of the first lens and the lens holder abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The radial positioning portion is constituted by a radially inner wall surface of the groove portion and a surface of the lens holding frame facing the wall surface.

10. The lens unit according to claim 2 or 7, characterized in that: On the outer surface of the first lens, a concave portion, a convex portion, a cut, a knurling, a serration, a spline, or other concave and convex portions that enable a clamp, a tool or a finger to engage in a circumferential direction are provided at a position that is unrelated to the optical performance of the first lens.

11. The lens unit according to claim 1, characterized in that: The direction perpendicular to the optical axis is called the radial direction. The first lens has: a lens portion, the lens portion determining the optical performance of the first lens; and a non-lens portion extending radially outward from the lens portion, A plurality of holes are formed in the non-lens portion, The first lens is fixed to the lens holding frame by passing a screw through the hole of the non-lens portion.

12. The lens unit according to claim 11, characterized in that: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism, the optical axis direction positioning portions of the first lens and the lens holder abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction. The optical axis direction positioning portion is composed of an image side surface of the non-lens portion and a surface of the lens holding frame that faces the image side surface.

13. The lens unit according to claim 11, characterized in that: The first lens and the lens holder have a radial positioning portion different from the fixing mechanism, the radial positioning portions of the first lens and the lens holder abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder, The first lens has a cylindrical or columnar fitting portion disposed radially inward of the O-ring. The radial positioning portion is constituted by an outer peripheral surface of the fitting portion and a surface of the lens holding frame facing the outer peripheral surface.

14. The lens unit according to claim 1, wherein: The first lens and the lens holder have an optical axis direction positioning portion different from the fixing mechanism. The optical axis direction positioning portions of the first lens and the lens holder abut against each other in the optical axis direction and determine the position of the first lens relative to the lens holder in the optical axis direction.

15. The lens unit according to claim 1, characterized in that: The direction perpendicular to the optical axis is called the radial direction. The first lens and the lens holder have radial positioning parts different from the fixing mechanism. The radial positioning parts of the first lens and the lens holder abut against each other in the radial direction and determine the radial position of the first lens relative to the lens holder.

16. The lens unit according to claim 1, characterized in that The first lens and the lens holding frame are bonded together by an adhesive.

17. The lens unit according to claim 16, characterized in that: The adhesive is a disassembly adhesive that can be released by subjecting the bonding portion of the adhesive to a specific treatment after bonding.

18. The lens unit according to claim 1, wherein: It has a plurality of lenses arranged along the optical axis. The first lens is a lens disposed closest to the object among the plurality of lenses. A lens disposed on the image side of the first lens is fixed to the lens holding frame by caulking.

19. A camera unit, characterized in that: have: A plurality of lenses arranged along the optical axis; A cylindrical lens holder; O-ring as a sealing component; camera module; and a camera housing for housing the camera module, When the lens closest to the object among the plurality of lenses is referred to as the first lens, The lens holding frame holds the lens disposed on the image side of the first lens. The direction perpendicular to the optical axis is called the radial direction. The first lens has: a lens portion, the lens portion determining the optical performance of the first lens; and a non-lens portion extending radially outward from the lens portion, A plurality of holes are formed in the non-lens portion, The first lens is fixed to the object side surface of the camera housing by inserting a screw through the hole of the non-lens portion. The O-ring is sandwiched by the first lens and the camera housing or the lens holding frame in the optical axis direction.

Images