Lens unit, imaging module, imaging device, and method for manufacturing lens unit

Abstract

We provide lens units that can be assembled at low cost and with high precision. [Solution] The lens unit 100 comprises a lens assembly (1, 2, 3, 4, 5) in which a plurality of lenses are fixedly arranged, and a cylindrical part 12 that covers the portion of the lens assembly other than the optically effective part. The plurality of lenses include lens 1, lens 2, and lens 3. Lens 1 has a flange portion 11 that defines a housing space 110 for housing lenses 2 and lens 3. Lenses 2 and lens 3 face the flange portion in a direction PD perpendicular to the optical axis OA of the lens assembly. The inner circumference of the flange portion is provided with a tapered portion 101 and an inner circumferential surface 113 for supporting lenses 2 and lens 3 in the housing space.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a lens unit, an imaging module, an imaging apparatus, and a method for manufacturing the lens unit.

BACKGROUND ART

[0002] In recent years, with higher precision of CMOS sensors and the development of communication technologies, cameras are mounted in various types of equipment, and the demand for small lens units is increasing. Small-diameter plastic lenses are widely used in small lens units.

[0003] The small-diameter lens unit includes a lens barrel and a plurality of imaging lenses. Due to the size relationship of the lens diameters of the plurality of imaging lenses, the assembly of the small lens unit generally starts from assembling the lens on the object side into the lens barrel, and in a state where the plurality of lenses are stacked, the lens on the imaging element side is finally assembled into the lens barrel. As a technique for reducing the number of assembly steps, Patent Document 1 discloses a method of integrally molding the lens positioned closest to the object side with the lens barrel. As a technique for improving assembly accuracy, Patent Document 2 discloses a method of extending the flange portion of a specific lens incorporated inside the lens barrel, and accommodating and assembling an adjacent single lens in the inner peripheral portion of the flange portion.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0004]

PATENT DOCUMENT 1

PATENT DOCUMENT 2

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] In the configuration disclosed in Patent Document 1, the lens and lens barrel located closest to the objective lens are integrated before assembly. The lens material is transparent resin. On the other hand, the lens barrel material is black resin and has a light-shielding function. In order to integrally mold dissimilar materials with high precision, expensive molding equipment for die-slide injection or rotary two-color molding is essential, resulting in high equipment investment costs. Furthermore, during integral molding, the dimensions of the primary molded body may change due to the heat and pressure of the secondary molding resin.

[0006] In the configuration disclosed in Patent Document 2, all of the multiple lenses are housed within the lens barrel to assemble the lens unit. The flange of the lens located closest to the objective lens is extended and bent toward the object, forming a housing space. Only one adjacent lens is housed within this housing space. The accuracy of the inner surface of the lens housing space has shape and dimensional accuracy equivalent to that of the optical surface of the lens. Therefore, when assembling adjacent lenses based on the inner surface of the housing space, the assembly of the lens unit can be made relatively more accurate compared to when assembling based on the inner surface of the lens barrel. However, because the outer shape of the lens located closest to the objective lens is lightly press-fitted into the inner diameter of the lens barrel to position the lens with high precision relative to the lens barrel, the lens may deform. Therefore, there is a need for lens units that can be assembled at low cost and with high precision. [Means for solving the problem]

[0007] The lens unit of this disclosure is A lens assembly in which multiple lenses are fixedly arranged, A light-shielding portion that covers the portion of the lens assembly other than the optically effective portion, Equipped with, The plurality of lenses include a first lens, a second lens, and a third lens. The first lens has a flange portion that defines a housing space for housing the second lens and the third lens. The second lens and the third lens are positioned opposite the flange portion in a direction perpendicular to the optical axis of the lens assembly. The inner circumference of the flange portion is provided with a support portion for supporting the second lens and the third lens within the housing space. It is characterized by the following: [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a lens unit that can be assembled at low cost and with high precision. [Brief explanation of the drawing]

[0009] [Figure 1] A cross-sectional view of the lens unit after assembly according to this embodiment. [Figure 2] A cross-sectional view of the lens unit in its disassembled state according to this embodiment. [Figure 3] A flowchart illustrating the manufacturing method of the lens unit according to this embodiment. [Figure 4] A cross-sectional view of a conventional assembled lens unit. [Figure 5] Cross-sectional view of a conventionally disassembled lens unit. [Figure 6] A cross-sectional view of an imaging device equipped with the lens unit of this embodiment. [Figure 7] A cross-sectional view of another imaging device equipped with the lens unit of this embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are only one embodiment of the invention and are not limited thereto. Common components will be described with reference to multiple drawings, and components with common reference numerals will be omitted from description as appropriate. Different items with the same name can be distinguished by adding "item number ○," such as "item number 1," "item number 2," etc.

[0011] (Lens unit) The optical lens unit (hereinafter referred to as "lens unit") 100 according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view of the assembled lens unit 100 according to this embodiment. Figure 2 is a cross-sectional view of the disassembled lens unit 100 according to this embodiment. The lens unit 100 comprises a lens assembly (1, 2, 3, 4, 5) and a cylindrical part 12 as a light-shielding part. The lens assembly includes lenses 1, 2, 3, 4, and 5. Lens 1 is positioned closest to the object in the lens assembly. Lenses 2, 3, 4, and 5 are positioned on the opposite side of lens 1 from the object side. Lens 1 is the first lens counting from the object side. Lens 2 is the second lens counting from the object side. Lens 3 is the third lens counting from the object side. Lens 4 is the fourth lens counting from the object side. Lens 5 is the fifth lens counting from the object side. In this embodiment, the lens unit 100 includes five lenses, but the number of lenses is not limited to this and may be two, three, four, or six or more.

[0012] As shown in Figure 2, the flange portion 11 of lens 1 is bent and extended toward the sensor side (image side), defining a housing space 110 capable of accommodating other lenses. The flange portion 11 may be made of the same material as the lens portion 13 of lens 1. The lens portion 13 of lens 1 may be made of a resin material. For example, the lens portion 13 and the flange portion 11 of lens 1 may be made of the same transparent resin material. The housing space 110 has a shape like a truncated conical pyramid with multiple circular cross-sections whose diameter decreases toward the object side. However, the shape of the housing space 110 is not limited to this. The tapered portion 201 formed on the object side of the flange portion of the second lens 2 from the object side fits into the tapered portion 101 (tapered fitting portion) formed on the inner circumferential surface (inner circumferential portion) of the flange portion 11 that defines the housing space 110. The tapered portion 101 functions as a support for supporting lens 2 within the housing space 110. Lens 2 faces the flange portion 11 in a direction PD perpendicular to the optical axis OA of the lens assembly. The outer peripheral surface 205 of lens 2, which faces the flange portion 11 in direction PD, may be in contact with the inner peripheral surface (inner peripheral portion) 112 of the flange portion 11. A ring-shaped light-shielding sheet 8 (light-shielding body) is placed between lens 1 and lens 2.

[0013] The tapered portion 302 formed on the object side surface of the flange portion of the third lens 3 counted from the object side fits into the tapered portion 202 formed on the sensor side surface of the flange portion of the lens 2. The lens 3 faces the flange portion 11 in the direction PD perpendicular to the optical axis OA of the lens assembly. The outer peripheral side surface 301 of the lens 3, which is the surface facing the flange portion 11 in the direction PD, may be in contact with the inner peripheral surface (inner peripheral portion) 113 of the flange portion 11. In the present embodiment, the lens 3 is supported by the tapered portion 202 of the lens 2. However, the present embodiment is not limited to this, and the lens 3 may be supported in the accommodation space 110 by a support portion provided on the inner peripheral portion of the flange portion 11 of the lens 1. For example, the outer peripheral side surface 301 of the lens 3 may be configured to fit into the inner peripheral surface 113 (inner peripheral surface fitting portion) of the flange portion 11 that defines the accommodation space 110. The inner peripheral surface 113 may function as a support portion for supporting the lens 3 in the accommodation space 110. The cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 2 is smaller than the cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 3. An annular light shielding sheet 9 (light shielding body) is disposed between the lens 2 and the lens 3.

[0014] The outer peripheral side surface 401 of the fourth lens 4 counted from the object side fits into the inner peripheral surface 104 (inner peripheral surface fitting portion) of the flange portion 11 that defines the accommodation space 110. The inner peripheral surface 104 functions as a support portion for supporting the lens 4 in the accommodation space 110. The lens 4 faces the flange portion 11 in the direction PD perpendicular to the optical axis OA of the lens assembly. The outer peripheral side surface 401 of the lens 4, which is the surface facing the flange portion 11 in the direction PD, may be in contact with the inner peripheral surface (inner peripheral portion) 104 of the flange portion 11. The cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 3 is smaller than the cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 4. An annular light shielding sheet 10 (light shielding body) is disposed between the lens 3 and the lens 4. On the sensor side of the lens 4, an annular spacer 6 for inter-lens adjustment and an annular light shielding sheet 13 (light shielding body) are disposed.

[0015] The fifth lens 5 counted from the object side is located closest to the sensor side. Unlike the other lenses, the lens 5 does not have a fitting surface that directly fits to an adjacent component. During assembly, the lens 5 is placed on the light shielding sheet 13 and arranged in the accommodation space 110. The lens 5 faces the flange portion 11 in the direction PD perpendicular to the optical axis OA of the lens assembly. The outer peripheral side surface 503 of the lens 5, which is the surface facing the flange portion 11 in the direction PD, may be in contact with the inner peripheral surface (inner peripheral portion) 105 of the flange portion 11. The cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 4 is smaller than the cross-sectional area of a cross section perpendicular to the optical axis OA in the accommodation space 110 and including the lens 5. Along the peripheral edge of the lens 5, a fixing member such as an adhesive 7 is applied circumferentially so as to span across the flange portion 501 of the lens 5 and the inner peripheral surface 105 of the flange portion 11 that defines the accommodation space 110. Thereby, the lenses 1 to 5 are fixed as an integrated lens assembly.

[0016] In the lens assembly, the lenses 1 to 5 (the plurality of lenses), the light shielding sheets 8, 9, 10, 13 (light shielding bodies) and the spacer 6 are fixedly arranged. The lens assembly is not limited to this, and may include only the plurality of lenses, or may include light shielding components and / or spacers in addition to the plurality of lenses. The lens 1 is a specific lens provided with an accommodation space 110 that accommodates all other lenses (lenses 2 to 5) except the lens 1. However, the lens 1 is not limited to this, and may be provided with an accommodation space that accommodates at least two or more lenses. The tapered portion 101 and the inner peripheral surface 104 of the flange portion 11 are reference shape portions for arranging at least two or more lenses at predetermined positions in the accommodation space 110 respectively. The reference shape portion is not limited to this, and the reference shape portion preferably includes a tapered fitting portion and / or an inner peripheral surface fitting portion. For example, the reference shape portion may include a plurality of tapered fitting portions and a plurality of inner peripheral surface fitting portions, may include only the tapered fitting portions, or may include only the inner peripheral surface fitting portions.

[0017] Since the lens 1, which occupies the majority of the outer surface of the lens assembly, is a transparent component, it does not have a light-shielding function. Therefore, the lens assembly is housed and fixed in a cylindrical component 12 (light-shielding part), which is an opaque cylindrical light-shielding component that has a light-shielding function. The cylindrical component 12 is a light-shielding material that covers the portion of the lens assembly other than the optically effective portion. This forms a lens unit 100 including the lens assembly and the cylindrical component 12. The lens assembly may also be covered with a member or paint that shields the portion of the lens assembly other than the optically effective portion as a light-shielding material. The light-shielding part that shields the portion of the lens assembly other than the optically effective portion does not necessarily have to be cylindrical and may be composed of multiple members. The light-shielding part may also be a light-shielding film that covers the flange portion 11.

[0018] The material of lens 1 may be, for example, transparent plastics such as optical glass or organic glass. The cylindrical part 12 may be made of resin or metal. The cylindrical part 12 only needs to be able to accommodate the lens assembly and does not require particularly high dimensional accuracy, making it possible to manufacture it inexpensively. In this embodiment, light-shielding sheets 8, 9, 10 and 13 are placed between the lenses as light-shielding components, but the light-shielding means is not limited to this. Instead of light-shielding sheets 8, 9, 10 and 13, the flange portion of each lens may be painted with black paint.

[0019] According to this disclosure, the flange portion 11 of the lens 1 closest to the object is extended to form a housing space 110 that accommodates all the other lenses, so that the inner circumference of the housing space 110 has dimensional accuracy equivalent to that of the lens optical surface. Therefore, the other lenses can be assembled with high precision. Furthermore, it becomes possible to assemble the lens assembly without a lens barrel. According to this disclosure, the assembly process of the lens unit 100 can be reduced and the difficulty of assembly can be simplified, and the manufacturing cost of the lens unit 100 can be reduced. According to this disclosure, a lens unit 100 that can be assembled with high precision at low cost can be provided.

[0020] (Lens unit manufacturing method) The manufacturing method of the lens unit 100 will be described below. Figure 3 is a flowchart showing the manufacturing method of the lens unit 100 according to this embodiment. First, a lens 1 having a bent and extended flange portion 11 that defines a housing space 110 is prepared (S1). Next, lenses 2 to 5 are placed in the housing space 110 (S2). Lenses 2 to 5 are supported by support portions provided on the flange portion 11. Lenses 2 to 5 are positioned facing the flange portion 11 in a direction PD perpendicular to the optical axis OA of the lens assembly. Lenses 2 to 5 may be positioned in the housing space 110 such that, in view of direction PD, the respective sides of lenses 2 to 5 are not exposed from the flange portion 11. In order to make lenses 1 to 5 into an integrated lens assembly, adhesive 7 is applied along the periphery of lens 5 and the lens 5 is fixed to the flange portion 11 with adhesive 7 (S3). In order to form the lens unit 100, the portion of the lens assembly other than the optically effective portion is covered with a cylindrical component 12 (S4).

[0021] According to the lens unit manufacturing method of this embodiment, the manufacturing process for the lens unit 100 can be reduced, thereby lowering manufacturing costs.

[0022] (Conventional lens unit) A conventional lens unit 200 will be explained using Figures 4 and 5. Figure 4 is a cross-sectional view of a conventional assembled lens unit 200. Figure 5 is a cross-sectional view of a conventional disassembled lens unit 200. The lens unit 200 includes lenses 21, 22, 23, 24, 25 and a lens barrel 33. Lens 21 is the first lens counting from the object side. Lens 22 is the second lens counting from the object side. Lens 23 is the third lens counting from the object side. Lens 24 is the fourth lens counting from the object side. Lens 25 is the fifth lens counting from the object side.

[0023] Multiple lenses are assembled inside the lens barrel 33, using the inner circumferential surface of the lens barrel 33 as a reference. As shown in Figure 5, in the first step of assembly, the outer circumferential surface 103 of the lens 21 located closest to the object is fitted to the inner circumferential surface 106 of the lens barrel 33. The tapered portion 203 formed on the object side of the flange of the second lens 22 from the object side fits into the tapered portion 107 formed on the sensor side of the flange of lens 21. An annular light-shielding sheet 28 is placed between lens 21 and lens 22. The tapered portion 303 formed on the object side of the flange of the third lens 23 from the object side fits into the tapered portion 204 formed on the sensor side of the flange of lens 22. An annular light-shielding sheet 29 is placed between lens 22 and lens 23.

[0024] The outer peripheral surface 402 of the fourth lens 24, counting from the object side, fits into the inner peripheral surface 111 of the lens barrel 33. An annular light-shielding sheet 30 is placed between lenses 23 and 24. An annular spacer 26 and an annular light-shielding sheet 31 for lens spacing adjustment are placed on the sensor side of lens 24. The fifth lens 25, counting from the object side, is located closest to the sensor. Unlike the other lenses, lens 25 does not have a mating surface that directly fits into adjacent parts. During assembly, lens 25 is placed on the light-shielding sheet 31 and positioned inside the lens barrel 33. In the final step of assembly, adhesive 27 is applied circumferentially along the periphery of lens 25, spanning the flange portion 502 of lens 25 and the inner peripheral surface (inner circumference) 108 of the lens barrel 33. This fixes lenses 21 through 25 and the lens barrel 33 as an integrated lens unit 200.

[0025] In the lens unit 200, the lens 21, which is located closest to the object, fits into the lens barrel 33 and also fits into the adjacent second lens 22. Therefore, the assembly position accuracy of lens 21 has a significant impact on the overall assembly accuracy of the lens unit 200. In addition, lenses 22 and 23 are assembled by tapered fitting with respect to lens 21, but there is a constraint that lens 21 must not move relative to the lens barrel 33 due to the load applied during assembly.

[0026] To achieve both improved positional accuracy and improved fit strength, it is preferable to press-fit the lens 21 into the lens barrel 33. However, if the press-fit is too strong, the lens 21 will be distorted and the optical accuracy will decrease, so it is necessary to appropriately control the amount of press-fit. However, appropriately controlling the amount of press-fit is not easy, and this leads to the problem of high adjustment costs.

[0027] In contrast to the problems of the conventional configuration described above, the lens 1 located closest to the object in the lens unit 100 of this embodiment has the positioning function of the conventional lens barrel 33, thus eliminating the need for adjustment of the press-fit amount. Lens 1 has a positioning function for positioning lenses 2 and 4 relative to lens 1, for example. Lens 1 may also have a positioning function for positioning lenses 3 and 5 relative to lens 1. The inner circumferential surface 104 of the extended flange portion 11 of lens 1 fits onto the outer circumferential side surface 401 of lens 4, but since lens 4 does not require the same strict positional accuracy as lens 1, control of the press-fit amount is unnecessary. If a certain amount of press-fit is required for fitting lens 4, a constricted portion 109 can be provided on the object side (outer surface) of the extended flange portion 11 of lens 1. In that case, the load when press-fitting lens 4 into lens 1 is absorbed by the deformation of the constricted portion 109, making it possible to achieve both press-fitting of lens 4 and prevention of lens 4 deformation. The constricted portion 109 (the part where the wall thickness is locally reduced) is preferably located in the flange portion 11 between the lens portion 13 of lens 1 and the inner circumferential surface 104 into which lens 4 is press-fitted.

[0028] Since the cylindrical component 12 of this embodiment can be manufactured at low cost, the cost of the cylindrical component 12 is relatively small compared to the conventional cost of adjusting the press-fit amount. Compared with the conventional lens unit 200, the lens unit 100 of this embodiment can achieve relatively high precision and low cost.

[0029] In this embodiment, an example is shown in which the flange portion 11 of the lens 1 located closest to the object is bent and extended toward the sensor side, and all other lenses are housed inside lens 1. However, this embodiment is not limited to this. For example, the flange portion of the second lens located from the object side may be bent and extended, and the third and fourth lenses may be housed in the housing space of the second lens, while the first and fifth lenses are configured independently. Alternatively, the housing relationship may be reversed, and the flange portion of the fourth lens may be bent and extended toward the object side, and the second and third lenses may be housed in the housing space of the fourth lens. As the number of lenses increases, various patterns can be considered, but there are no restrictions on which lens is housed inside which lens.

[0030] (Imaging equipment) Figure 6 is a cross-sectional view of an imaging device 600 equipped with the lens unit 100 of this embodiment. The imaging device 600 includes an imaging module 601 having the lens unit 100 and an image sensor 602 that receives the image formed by the lens unit 100. The imaging device 600 also includes a display element 603 that displays the image captured by the image sensor 602. The imaging device 600 may be, for example, a digital video camera, a digital still camera, a broadcast camera, a surveillance camera, or a communication device such as a smartphone.

[0031] Figure 7 is a cross-sectional view of another imaging device 700 equipped with the lens unit 100 of this embodiment. The imaging device 700 includes an imaging module 701 having the lens unit 100 and an image sensor 702 that receives the image formed by the lens unit 100. The imaging device 700 includes a light-emitting element 703 that illuminates the subject being imaged by the image sensor 702. The light-emitting element 703 may be, for example, a flashing device or a light guide. The imaging device 700 may be, for example, a digital video camera, a digital still camera, a broadcast camera, a surveillance camera, or an endoscope.

[0032] The embodiments described above can be modified as appropriate without departing from the technical concept. For example, multiple embodiments can be combined. Furthermore, some aspects of at least one embodiment can be deleted or replaced. Furthermore, new aspects can be added to at least one embodiment. Note that the disclosures in this specification include not only those explicitly stated herein, but also all matters that can be understood from this specification and the drawings attached thereto.

[0033] (Configuration 1) A lens unit comprising a lens assembly in which a plurality of lenses are fixedly arranged, and a light-shielding portion that covers a portion of the lens assembly other than the optically effective portion, wherein the plurality of lenses include a first lens, a second lens, and a third lens, the first lens has a flange portion that defines a housing space for housing the second lens and the third lens, the second lens and the third lens face the flange portion in a direction perpendicular to the optical axis of the lens assembly, and the inner circumference of the flange portion is provided with a support portion for supporting the second lens and the third lens in the housing space. (Configuration 2) The lens unit according to Configuration 1, characterized in that the surfaces of the second lens and the third lens that face the flange in the aforementioned direction are in contact with the flange. (Configuration 3) The lens unit according to Configuration 1 or 2, characterized in that the first lens is positioned closest to the object among the lens assembly. (Configuration 4) The lens unit according to any one of Configurations 1 to 3, characterized in that the second lens and the third lens are arranged on the opposite side from the object side relative to the first lens. (Configuration 5) The lens unit according to any one of Configurations 1 to 4, characterized in that all of the plurality of lenses except the first lens are housed in the housing space. (Configuration 6) The lens unit according to any one of Configurations 1 to 5, characterized in that the support portion includes a tapered fitting portion and / or an inner circumferential fitting portion. (Configuration 7) The lens unit according to any one of Configurations 1 to 6, characterized in that the support portion includes an inner circumferential fitting portion, and the first lens has a portion between the lens portion of the first lens and the inner circumferential fitting portion in which the thickness is locally reduced. (Configuration 8) The lens unit according to any one of Configurations 1 to 7, characterized in that it includes a light shield and / or a spacer disposed between two lenses of the lens assembly. (Configuration 9) The lens unit according to any one of Configurations 1 to 8, characterized in that the cross-sectional area of ​​the section in the housing space that is perpendicular to the optical axis and includes the second lens is smaller than the cross-sectional area of ​​the section in the housing space that is perpendicular to the optical axis and includes the third lens. (Configuration 10) The lens unit according to any one of Configurations 1 to 9, characterized in that the flange portion is made of the same material as the lens portion of the first lens. (Configuration 11) The lens unit according to any one of Configurations 1 to 10, characterized in that the lens portion of the first lens is made of a resin material. (Configuration 12) The lens unit according to any one of Configurations 1 to 11, characterized in that the light-shielding portion is a cylindrical light-shielding component. (Configuration 13) The lens unit according to any one of Configurations 1 to 12, characterized in that the light-shielding portion is a light-shielding film that covers the flange portion. (Configuration 14) An imaging module comprising a lens unit as described in any one of Configurations 1 to 13 and an image sensor. (Configuration 15) An imaging device comprising the imaging module described in Configuration 14 and a display element for displaying an image captured by the imaging sensor. (Configuration 16) An imaging device comprising the imaging module described in Configuration 14 and a light-emitting element that illuminates a subject to be imaged by the image sensor. (Method 1) A method for manufacturing a lens unit, comprising: providing a first lens having a flange portion that defines a housing space; arranging a second lens and a third lens in the housing space to form a lens assembly; and covering the portion of the lens assembly other than the optically effective portion with a light-shielding material to form a lens unit. (Method 2) The lens unit manufacturing method according to Method 1, characterized in that arranging the second lens and the third lens in the housing space includes supporting the second lens and the third lens with a support provided on the flange. (Method 3) The lens unit manufacturing method according to Method 1 or 2, characterized in that arranging the second lens and the third lens in the housing space includes arranging the second lens and the third lens facing the flange portion in a direction perpendicular to the optical axis of the lens assembly. (Method 4) A method for manufacturing a lens unit according to any one of Methods 1 to 3, further comprising fixing the second lens and the third lens to the flange portion. [Explanation of symbols]

[0034] 1...Lens, 2...Lens, 3...Lens, 4...Lens, 5...Lens, 12...Cylindrical part, 100...Lens unit, 101...Tapered section, 113...Inner circumferential surface, OA...Optical axis, PD...Direction perpendicular to the optical axis OA

Claims

1. A lens assembly in which multiple lenses are fixedly arranged, A light-shielding portion that covers the portion of the lens assembly other than the optically effective portion, Equipped with, The plurality of lenses include a first lens, a second lens, and a third lens. The first lens has a flange portion that defines a housing space for housing the second lens and the third lens. The second lens and the third lens are positioned opposite the flange portion in a direction perpendicular to the optical axis of the lens assembly. The inner circumference of the flange portion is provided with a support portion for supporting the second lens and the third lens within the housing space. A lens unit characterized by the following features.

2. The surfaces of the second lens and the third lens that face the flange in the aforementioned direction are in contact with the flange. The lens unit according to feature 1.

3. The first lens is positioned closest to the object in the lens assembly. The lens unit according to feature 1.

4. The second lens and the third lens are positioned on the side opposite to the object side relative to the first lens. The lens unit according to feature 1.

5. The aforementioned housing space houses all of the multiple lenses except for the first lens. The lens unit according to feature 1.

6. The support portion includes a tapered fitting portion and / or an inner circumferential fitting portion. The lens unit according to feature 1.

7. The support portion includes an inner circumferential fitting portion, The first lens has a portion between the lens portion of the first lens and the inner circumferential fitting portion where the thickness is locally reduced. The lens unit according to feature 1.

8. The lens assembly includes a light shield and / or spacer, positioned between the two lenses of the aforementioned lens assembly. The lens unit according to feature 1.

9. The cross-sectional area of ​​the section in the housing space that is perpendicular to the optical axis and includes the second lens is smaller than the cross-sectional area of ​​the section in the housing space that is perpendicular to the optical axis and includes the third lens. The lens unit according to feature 1.

10. The flange portion is made of the same material as the lens portion of the first lens. The lens unit according to feature 1.

11. The lens portion of the first lens is made of a resin material. The lens unit according to feature 1.

12. The light-shielding part is a cylindrical light-shielding component. The lens unit according to feature 1.

13. The light-shielding portion is a light-shielding film that covers the flange portion. The lens unit according to feature 1.

14. An imaging module comprising a lens unit according to any one of claims 1 to 13 and an image sensor.

15. An imaging device comprising an imaging module according to claim 14 and a display element for displaying an image captured by the imaging element.

16. An imaging device comprising an imaging module according to claim 14 and a light-emitting element for illuminating a subject to be imaged by the image sensor.

17. A first lens having a flange portion that defines the containment space is provided, In order to form a lens assembly, the second lens and the third lens are placed in the housing space, In order to form a lens unit, the portion of the lens assembly other than the optically effective portion is covered with a light-shielding material, A method for manufacturing a lens unit comprising the following features.

18. Arranging the second lens and the third lens in the aforementioned housing space includes supporting the second lens and the third lens with the support portion provided on the flange portion. The method for manufacturing a lens unit according to feature 17.

19. Arranging the second lens and the third lens in the aforementioned housing space includes arranging the second lens and the third lens facing the flange portion in a direction perpendicular to the optical axis of the lens assembly. The method for manufacturing a lens unit according to feature 17.

20. The second lens and the third lens are further fixed to the flange portion. The method for manufacturing a lens unit according to feature 17.

Images