JP2009251210A - Imaging lens, imaging apparatus, electronic apparatus, portable terminal, and method for manufacturing imaging lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging lens and the like, which are compact, can be mass-produced and have high performance,. <P>SOLUTION: The imaging lens LN includes at least one lens block BK having: a lens substrate LS which is a parallel flat plate; and a lens L with positive or negative power connected to at least the object-side or image-side substrate face of the lens substrate LS. In such an imaging lens LN, the lens L is made of a resin, which is different from the material of the lens substrate LS. Further, at least one of the lenses L satisfies a predetermined conditional expression relating to a refractive index. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging lens, an imaging device, an electronic device, a mobile terminal, and a manufacturing method of the imaging lens.

  Nowadays, a compact and thin imaging device is mounted on a portable terminal (for example, a mobile phone or a PDA (Personal Digital Assistant)) which is a compact and thin electronic device. Information such as audio information and image information obtained from the image sensor is transmitted bidirectionally between such a portable terminal and, for example, a remote electronic device.

  Examples of the image pickup element used in the image pickup apparatus include a solid-state image pickup element such as a charge coupled device (CCD) image sensor and a complementary metal-oxide semiconductor (CMOS) image sensor. The increase in the number of pixels of these image pickup devices is remarkable, and accordingly, the need for higher resolution and higher performance of an image pickup lens that forms a subject image on the image pickup device is increasing. For example, it has high aberration correction capability).

  Therefore, recently, the imaging lens is molded with resin. This is because the resin-made imaging lens is not only easily processed, but also a complicated aspherical shape is accurately transferred to achieve high resolution and high performance. In addition, since the resin imaging lens can be mass-produced, the cost of the imaging lens can be reduced. Furthermore, when mass-producing imaging lenses at a low cost, an energy curable resin (a resin that cures with energy such as light) is selected as compared with a thermoplastic resin lens that requires a heating process and a cooling process. Many.

  Further, in order to mount the imaging lens on a small portable terminal or the like, it is required to be further downsized while achieving high resolution and high performance. However, it is difficult to achieve both compactness and mass production of the imaging lens due to technical limitations.

As a countermeasure for overcoming such problems, Patent Documents 1 and 2 include a replica method in which a large number of lenses (lens elements) are simultaneously formed on one lens flat plate (wafer). With this method, the imaging lens is produced in large quantities while being compact.
JP 2006-323365 A Japanese Patent No. 3929479

  However, when the resin is a curable resin that is cured by light energy such as ultraviolet rays or a thermosetting resin that is cured by thermal energy, the energy must be uniformly applied to the resin (lens resin) that becomes the lens. This is because if the energy is not uniformly applied to the lens resin, uneven curing occurs, and a refractive index distribution occurs in the lens, and a homogeneous lens is not completed.

  In addition, in an ultra-small imaging lens for a mobile phone that is subject to severe restrictions on size and the like, the aspherical shape of the lens surface is likely to be complicated and the thickness difference between the lenses tends to be large in order to improve optical performance. Further, when such an imaging lens is formed of an energy curable resin, the problem of uneven curing and insufficient curing appears remarkably.

  And in the case of the refractive index which the lens resin of patent document 1 and 2 has, the thickness of a lens becomes comparatively thick easily and energy is hard to be given to lens resin uniformly. Therefore, the lenses described in Patent Documents 1 and 2 are difficult to be a homogeneous lens (that is, a high-performance lens is not completed).

  In addition, in order to manufacture a homogeneous lens, it is assumed that the thicknesses of the lenses described in Patent Documents 1 and 2 are relatively thin and energy is uniformly applied to the lens resin. However, in such a case, since the thickness of the lens is reduced, the power of the lens is weakened, and the distance between the axial upper surfaces of the lenses may be increased (in short, the optical total length of the imaging lens is increased). In addition, since the lens power is weakened, the aberration correction capability is also lowered, and it is difficult to complete a high-performance imaging lens.

  The present invention has been made in view of the above situation. An object of the present invention is to provide an imaging lens or the like having high performance in addition to being compact and capable of mass production.

  The imaging lens includes a lens block including a lens substrate that is a parallel plate, and a lens having positive power or negative power that is continuous with at least one of the object-side substrate surface and the image-side substrate surface of the lens substrate. Contains at least one or more. In this imaging lens, the lens is made of a resin (resin material) different from the material of the lens substrate, and at least one of the lenses is a specific lens that satisfies the following conditional expression (A1).

1.61 ≦ Nd [L] (A1)
However,
Nd [L]: Refractive index of the resin serving as the specific lens with respect to the d-line.

  Moreover, it is desirable that at least one of the lens substrates satisfies the following conditional expression (A2).

1.58 ≦ Nd [LS] (A2)
However,
Nd [LS]: Refractive index of the material to be the specific lens substrate with respect to the d-line.

  In addition, it is desirable that at least one of the specific lenses has an aspheric lens surface in contact with air.

  In the imaging lens, it is preferable that the following conditional expression (A3) is satisfied.

0.4 ≦ | f [L] / f [all] | ≦ 1.1 (A3)
However,
f [L]: When it is assumed that the object side lens surface and the image side lens surface are in contact with air
The focal length of a specific lens at f [all] is the focal length of the entire imaging lens system.

  In the imaging lens, it is preferable that the following conditional expression (A4) is satisfied.

| Nd [L] −Nd [LS-L] | ≦ 0.25 (A4)
However,
Nd [L]: Refractive index of resin for specific lens with respect to d-line Nd [LS-L]: Material for lens substrate connected to specific lens for d-line
Refractive index.

  In the lens block, it is desirable that an optical thin film is interposed between the lens and the lens substrate, and the lens is in direct contact or indirect contact with the optical thin film.

  Moreover, it is desirable that the resin to be a lens is an energy curable resin.

  Further, it is desirable that inorganic fine particles having a particle diameter of 30 nm or less are dispersed in the energy curable resin to be a lens.

  Note that an imaging apparatus including the imaging lens as described above and an imaging element that captures light passing through the imaging lens can be said to be the present invention. An electronic apparatus including the imaging device and a control unit that controls the imaging operation of the imaging device to at least one of still image shooting and moving image shooting can be said to be the present invention. In addition, it is desirable that such an electronic device is a portable terminal.

  Further, in the method for manufacturing an imaging lens as described above, if a unit including a plurality of lens blocks arranged side by side is a lens block unit, it is preferable that the following steps are included. That is, it includes a connecting step of arranging a spacer on at least a part of the periphery of the lens block and connecting a plurality of lens block units with the spacer interposed therebetween, and a cutting step of cutting the connected lens block unit along the spacer. An imaging lens manufacturing method is desirable.

  According to the present invention, the lens becomes relatively thin by designing the refractive index of the resin to be the lens to be a certain level or more. Therefore, if the thin lens is formed of a resin that is cured by light energy or thermal energy, the energy is uniformly applied to the entire resin, and the lens is completed without including uneven curing. As a result, this lens is not affected by uneven curing and has high performance.

[Embodiment 1]
[About imaging devices and mobile terminals]
Usually, the imaging lens is suitable for use in a digital device (electronic device) with an image input function. This is because a digital device including a combination of an imaging lens and an imaging element is equipped with an imaging device that optically captures a subject image and outputs it as an electrical signal.

  The imaging device is a main component (optical device) of a camera that captures still images and moving images of a subject. For example, an imaging lens that forms an optical image of an object in order from the object (that is, subject) side, and the imaging lens And an image sensor that converts the optical image formed by the method into an electrical signal.

  Examples of the camera include a digital camera, a video camera, a surveillance camera, an in-vehicle camera, and a video phone camera. Cameras are built into personal computers, mobile terminals (for example, compact and portable information device terminals such as mobile phones and mobile computers), peripheral devices (scanners, printers, etc.), and other digital devices. Or it may be externally attached.

  As can be seen from these examples, not only a camera is configured by mounting an imaging apparatus, but also various devices having a camera function are configured by mounting the imaging apparatus. For example, a digital device with an image input function such as a mobile phone with a camera is configured.

  FIG. 14 is a block diagram of a mobile terminal CU that is an example of a digital device with an image input function. The imaging device LU mounted on the portable terminal CU in this figure includes an imaging lens LN, a plane parallel plate PT, and an imaging element SR (sometimes referred to as an imaging lens LN including the parallel plate PT).

  The imaging lens LN forms an optical image (image plane) IM of the object in order from the object (namely, subject) side. Specifically, the imaging lens LN includes, for example, a lens block BK (details will be described later), and forms an optical image IM on the light receiving surface SS of the imaging element SR.

  Note that the optical image IM to be formed by the imaging lens LN passes, for example, an optical low-pass filter (parallel plane plate PT in FIG. 14) having a predetermined cutoff frequency characteristic determined by the pixel pitch of the imaging element SR. To do. By this passage, the spatial frequency characteristics are adjusted so that so-called aliasing noise that occurs when converted into an electrical signal is minimized.

  The adjustment of the spatial frequency characteristics can suppress the occurrence of color moire. However, if the performance around the resolution limit frequency is suppressed, no noise is generated even if an optical low-pass filter is not used. Further, when a user performs shooting or viewing using a display system (for example, a liquid crystal screen of a mobile phone) that is not very noticeable, an optical low-pass filter is not necessary.

  The plane parallel plate PT is, for example, an optical filter such as an optical low-pass filter or an infrared cut filter disposed as necessary (the parallel plate PT may also correspond to a cover glass of the image sensor SR). is there).

  The imaging element SR converts the optical image IM formed on the light receiving surface SS by the imaging lens LN into an electrical signal. For example, a CCD (Charge Coupled Device) type image sensor having a plurality of pixels and a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor can be cited as the imaging device (solid-state imaging device). The imaging lens LN is positioned so as to form an optical image IM of the subject on the light receiving surface SS of the imaging element SR. Therefore, the optical image IM formed by the imaging lens LN is efficiently converted into an electrical signal by the imaging element SR.

  In addition, when such an imaging device LU is mounted on a portable terminal CU with an image input function, the imaging device LU is usually arranged inside the body of the portable terminal CU. However, when the mobile terminal CU exhibits the camera function, the imaging device LU takes a form as necessary. For example, the unitized imaging device LU may be detachable or rotatable with respect to the main body of the mobile terminal CU.

  By the way, the mobile terminal CU includes a signal processing unit 1, a control unit 2, a memory 3, an operation unit 4, and a display unit 5 in addition to the imaging device LU.

  The signal processing unit 1 performs, for example, predetermined digital image processing and image compression processing on the signal generated by the image sensor SR as necessary. The processed signal is recorded as a digital video signal in the memory 3 (semiconductor memory, optical disc, etc.), or converted into an infrared signal via a cable and transmitted to another device.

  The control unit 2 is a microcomputer and performs function control such as a photographing function and an image reproduction function, that is, control of a lens moving mechanism for focusing, and the like. For example, the control unit 2 controls the imaging device LU so as to perform at least one of still image shooting and moving image shooting of a subject.

  The memory 3 stores, for example, a signal generated by the image sensor SR and processed by the signal processing unit 1.

  The operation unit 4 includes operation members such as operation buttons (for example, a release button) and operation dials (for example, a shooting mode dial), and transmits information input by the operator to the control unit 2.

  The display unit 5 includes a display such as a liquid crystal monitor, and displays an image using an image signal converted by the imaging element SR or image information recorded in the memory 3.

[About imaging lens]
Here, the imaging lens LN will be described in detail. The imaging lens LN includes a lens block BK in which a plurality of optical elements are connected (see FIG. 1 and the like described later). The lens block BK, for example, connects the lens L to at least one of the two surfaces (object-side substrate surface and image-side substrate surface) facing each other on the lens substrate LS (note that the lens L is Have positive power or negative power).

  Note that “continuous” means that the substrate surface of the lens substrate LS and the lens L are in a directly adhered state, or that the substrate surface of the lens substrate LS and the lens L are in an indirectly bonded state through another member. Means.

[■ Imaging lens manufacturing method]
By the way, as shown in the cross-sectional view of FIG. 15A, the lens block unit UT including a plurality of lens blocks BK arranged side by side is manufactured by, for example, a reflow method or a replica method that can simultaneously produce a large number of lenses L and is low in cost. (Note that the number of lens blocks BK included in the lens block unit UT may be singular or plural).

  In the reflow method, a low softening point glass is formed on a glass substrate by a CVD (Chemical Vapor Deposition) method. The low softening point glass film is finely processed by lithography and dry etching. Further, by heating, the low softening point glass film is melted into a lens shape. That is, in this reflow method, a large number of lenses are simultaneously produced on a glass substrate.

  In the replica method, a curable resin is transferred onto a lens wafer in a lens shape using a mold. Thus, in this replica method, a large number of lenses are simultaneously produced on the lens wafer.

  And the imaging lens LN is manufactured from the lens block unit UT manufactured by these methods. An example of the manufacturing process of this imaging lens is shown in the schematic cross-sectional view of FIG. 15B.

  The first lens block unit UT1 includes a first lens substrate LS1 that is a parallel plate, a plurality of first lenses L1 that are bonded to one plane, and a plurality of second lenses L2 that are bonded to the other plane. , Composed of.

  The second lens block unit UT2 includes a second lens substrate LS2 that is a parallel plate, a plurality of third lenses L3 bonded to one plane, and a plurality of fourth lenses L4 bonded to the other plane. , Composed of.

  The lattice-shaped spacer member (spacer) B1 is between the first lens block unit UT1 and the second lens block unit UT2 (specifically, between the first lens substrate LS1 and the second lens substrate LS2). The distance between the lens block units UT1 and UT2 is kept constant. Further, the spacer member B1 is interposed between the substrate 2 and the second lens block unit 2, and the distance between the substrate 2 and the lens block unit UT2 is kept constant (that is, the spacer member B1 can be said to be a two-stage lattice). ). And each lens L is located in the part of the hole of the grating | lattice of spacer member B1.

  The substrate B2 is a wafer-scale sensor chip size package including a microlens array, or a parallel flat plate such as a sensor cover glass or an IR cut filter (corresponding to the parallel flat plate PT in FIG. 14).

  Then, the spacer member B1 is interposed between the first lens block unit UT1 and the first lens block unit UT2, and between the second lens unit UT2 and the second substrate B2, so that the lens substrate The LSs (the first lens substrate LS1 and the second lens substrate LS2) are sealed and integrated.

  Then, when the integrated first lens substrate LS1, second lens substrate LS2, spacer member B1, and substrate 2 are cut along the lattice frame (the position of the broken line Q) of the spacer member B1, it is shown in FIG. 15C. As described above, a plurality of imaging lenses LN having a two-lens configuration are obtained.

  As described above, when the imaging lens LN is manufactured by separating the members in which the plurality of lens blocks BK (the first lens block BK1 and the second lens block BK2) are incorporated, the lens interval of each imaging lens LN is increased. Adjustment and assembly are not required. Therefore, mass production of the imaging lens LN is possible.

  Moreover, the spacer member B1 has a lattice shape. Therefore, the spacer member B1 also serves as a mark when the imaging lens LN is separated from the member in which the plurality of lens blocks BK are incorporated. Therefore, the imaging lens LN is easily separated from the member in which the plurality of lens blocks BK are incorporated, and it does not take time and effort. As a result, imaging lenses can be mass-produced at low cost.

  Based on the above, the manufacturing method of the imaging lens LN is connected to the connecting step of arranging the spacer member B1 on at least a part of the periphery of the lens block BK and connecting the plurality of lens block units UT with the spacer member B1 interposed therebetween. A cutting step of cutting the lens block unit UT along the spacer member B1. Such a manufacturing method is suitable for mass production of an inexpensive lens system.

[■ Lens configuration for imaging lens]
Next, lens configurations relating to the imaging lenses LN of Examples (EX) 1 to 5 and Comparative Example (CEX) will be described with reference to optical cross-sectional views of FIGS. The comparative examples are listed for comparison with, for example, Example 3 (details will be described later).

About the member code | symbol in an optical cross section etc., it is as follows.
Li: Lens L
LSi: Lens substrate LS (The lens substrate LS in all the examples is a parallel plate)
・ BKi: Lens block BK
PTi: Parallel flat plate (Note that PTi is attached only to a parallel flat plate without the lens L being connected)
Si: Lens surface and substrate surface i: Number given to "Li" etc., from object side to image side in each member
Order.
*: Aspherical surface (Note that the lens surface that is not adjacent to the lens substrate LS and is in contact with air is aspherical.
Surface)
#: Aperture stop AX: Optical axis

[● Example 1] to [● Example 3] and [● Comparison example]
As shown in FIGS. 1 to 3 and FIG. 6, the imaging lenses LN of Examples 1 to 3 and the comparative example include three lens blocks BK1 to BK3 arranged from the object side to the image side, and an aperture stop # And a parallel plate PT1.

  The first lens block BK1 located closest to the object side includes a first lens substrate LS1. The first lens L1 is connected to the object side substrate surface of the first lens substrate LS1, and the second lens L2 is connected to the image side substrate surface of the first lens substrate LS1. Specifically, the first lens L1 and the second lens L2 are as follows. The aperture stop # is formed on the boundary surface between the first lens L1 and the first lens substrate LS1.

First lens L1: Plano-convex lens convex on the object side Second lens L2: Plano-concave lens concave on the image side

  The second lens block BK2 is located on the image side of the first lens block BK1, and includes a second lens substrate LS2. The third lens L3 is connected to the object side substrate surface of the second lens substrate LS2, and the fourth lens L4 is connected to the image side substrate surface of the second lens substrate LS2. Specifically, the third lens L3 and the fourth lens L4 are as follows.

Third lens L3: Plano-concave lens concave on the object side Fourth lens L4: Plano-convex lens convex on the image side

  The third lens block BK3 is located on the image side of the second lens block BK2, and includes a third lens substrate LS3. The fifth lens L5 is connected to the object side substrate surface of the third lens substrate LS3, and the sixth lens L6 is connected to the image side substrate surface of the third lens substrate LS3. Specifically, the fifth lens L5 and the sixth lens L6 are as follows.

-5th lens L5: Plano-convex lens convex on the object side-6th lens L6: Plano-concave lens on the image side

  The parallel plate PT1 has a flat object side surface and image side surface. And this parallel plate PT1 may protect the image pick-up surface (light-receiving surface) of image pick-up element SR (In short, the parallel plate PT1 may become a cover glass). In addition, the parallel plate PT1 in the following embodiments is the same as the parallel plate PT1 in these embodiments.

[Example 4]
As shown in FIG. 4, the imaging lens LN of Example 4 includes a first lens block BK1 and a second lens block BK2, an aperture stop #, and a parallel plate PT1.

  In the first lens block BK1, the first lens L1 connected to the object side substrate surface of the first lens substrate LS1 and the second lens L2 connected to the image side substrate surface are as follows. The aperture stop # is formed on the boundary surface between the first lens L1 and the first lens substrate LS1.

First lens L1: Plano-convex lens convex on the object side Second lens L2: Plano-concave lens concave on the image side

  In the second lens block BK2, the third lens L3 connected to the object side substrate surface of the second lens substrate LS2 and the fourth lens L4 connected to the image side substrate surface are as follows.

Third lens L3: Plano-concave lens concave on the object side Fourth lens L4: Plano-concave lens concave on the image side

[Example 5]
As shown in FIG. 5, the imaging lens LN of Example 5 includes a first lens block BK1 to a fourth lens block BK4, an aperture stop #, and a parallel plate PT1.

  In the first lens block BK1, the first lens L1 connected to the object side substrate surface of the first lens substrate LS1 and the second lens L2 connected to the image side substrate surface are as follows. The aperture stop # is formed on the boundary surface between the first lens L1 and the first lens substrate LS1.

First lens L1: Plano-convex lens convex on the object side Second lens L2: Plano-convex lens convex on the image side

  In the second lens block BK2, the third lens L3 connected to the object side substrate surface of the second lens substrate LS2 and the fourth lens L4 connected to the image side substrate surface are as follows.

Third lens L3: Plano-convex lens convex on the object side Fourth lens L4: Plano-concave lens concave on the image side

  In the third lens block BK3, the fifth lens L5 connected to the object side substrate surface of the third lens substrate LS3 and the sixth lens L6 connected to the image side substrate surface are as follows.

Fifth lens L5: Plano-convex lens convex on the object side Sixth lens L6: Plano-convex lens convex on the image side

  The fourth lens block BK4 is located on the image side of the third lens block BK3 and includes a fourth lens substrate LS4. The seventh lens L7 is connected to the object side substrate surface of the fourth lens substrate LS4, and the eighth lens L8 is connected to the image side substrate surface of the fourth lens substrate LS4. Specifically, the seventh lens L7 and the eighth lens L8 are as follows.

Seventh lens L7: Plano-concave lens concave on the object side Eighth lens L8: Plano-concave lens concave on the image side

[■ Lens data related to imaging lenses]
Next, various data, construction data, and aspheric data in the imaging lenses LN of Examples (EX) 1 to 5 and Comparative Example (CEX) are shown below.

In addition, about the code | symbol in various data, it is as follows. Further, the F number, the half field angle, the total length of the imaging lens LN, and the back focus are effective values at a finite object distance.
F: Focal length [unit: mm]
Note that f [all] is the focal length of the entire imaging lens LN system, and f [BK1] to f [BK4].
Is the focal length of the lens blocks BK1 to BK4.
-Fno: F number-ω: Half angle of view [unit: °]
Y ′: image height (diagonal length of image plane) [unit: mm]
TL: Total length of the imaging lens LN [unit: mm]
Note that the lens from the foremost lens to the last lens in the imaging lens LN
Value obtained by adding the back focus distance to the distance at.
-BF: Back focus [unit: mm]
However, the distance from the last lens surface to the paraxial image surface is expressed in air equivalent length.

The codes in the construction data are as follows.
Si: Lens surface and substrate surface i: Number given to "si" etc., in order from the object side to the image side.
*: Aspheric surface #: Position of aperture stop r: Paraxial radius of curvature of lens surface or substrate surface [unit: mm]
・ D: Distance between shaft upper surfaces [unit: mm]
Nd: Refractive index of medium with respect to d-line (wavelength 587.56 nm) νd: Abbe number of medium with respect to d-line

The aspheric data is defined by the following equation (AS) using a local orthogonal coordinate system (x, y, z) with the surface vertex of the aspheric surface as the origin. The following K and A _j for each aspheric surface (si) are shown. For all data, “e−n” = “× 10 ⁻ⁿ ”.

z = (h ² / r) / (1 + √ [1- (1 + K) · h ² / r ² ]) + ΣA _j h ^j (AS)
However,
h: height in a direction perpendicular to the z-axis (optical axis AX) (h ² = x ² + y ² )
z: Sag amount in the optical axis AX direction at the position of height h (based on the surface vertex)
r: radius of curvature
K: Conical constant
A _j : j-th order aspheric coefficient (4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th order)
It is.

[Example 1]
f [all] 2.817
f [BK1] 2.239
f [BK2] -16.220
f [BK3] -3.924
Fno. 2.880
ω 31.968
Y '1.782
TL 2.927
BF 0.536

si rd nd vd
1 * 0.912 0.203 1.69350 53.20
2 # infinity 0.300 1.62889 35.48
3 infinity 0.050 1.67595 31.70
4 * 1.608 0.301
5 * -2.317 0.050 1.72624 28.87
6 infinity 0.300 1.48749 70.40
7 infinity 0.162 1.60366 46.96
8 * -2.647 0.508
9 * 2.081 0.050 1.48787 70.29
10 infinity 0.300 1.48996 70.09
11 infinity 0.166 1.75520 27.58
12 * 1.424 0.237
13 infinity 0.300 1.51633 64.14
14 infinity 0.101
15 infinity

s1 *
K = 4.32480e-001,
A4 = -5.00453e-002, A6 = 1.87923e-001, A8 = -1.09402e + 000, A10 = 1.51777e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s4 *
K = 6.53557e + 000,
A4 = -6.21007e-003, A6 = -5.49128e-001, A8 = 2.57413e + 000, A10 = -1.24149e + 001,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s5 *
K = 1.83249e + 001,
A4 = -9.27053e-002, A6 = 1.58635e-001, A8 = -4.56495e-001, A10 = 5.24505e-001,
A12 = -1.31438e + 001, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s8 *
K = -2.98953e + 001,
A4 = -2.78706e-001, A6 = 4.55647e-001, A8 = -9.61226e-002, A10 = -1.01586e-001,
A12 = -7.40595e-002, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s9 *
K = -3.43586e-001,
A4 = -5.97969e-001, A6 = 3.44436e-001, A8 = -2.40342e-003, A10 = -5.10024e-002,
A12 = 1.14958e-002, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s12 *
K = -8.58696e + 000,
A4 = -2.31197e-001, A6 = 1.12173e-001, A8 = -4.12474e-002, A10 = 1.14387e-002,
A12 = -1.38595e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000

[Example 2]
f [all] 2.913
f [BK1] 2.306
f [BK2] -12.382
f [BK3] -5.464
Fno. 2.880
ω 31.069
Y '1.782
TL 3.060
BF 0.599

si rd nd vd
1 * 0.921 0.203 1.69350 53.20
2 # infinity 0.300 1.68025 31.51
3 infinity 0.050 1.68247 31.94
4 * 1.607 0.315
5 * -2.357 0.065 1.74377 28.24
6 infinity 0.300 1.48749 70.40
7 infinity 0.161 1.58016 45.35
8 * -2.736 0.519
9 * 2.086 0.065 1.48896 70.24
10 infinity 0.300 1.53228 66.07
11 infinity 0.183 1.73627 35.89
12 * 1.622 0.294
13 infinity 0.300 1.51633 64.14
14 infinity 0.108
15 infinity

s1 *
K = 4.47429e-001,
A4 = -4.40213e-002, A6 = 1.96296e-001, A8 = -1.07750e + 000, A10 = 1.55680e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s4 *
K = 6.59829e + 000,
A4 = -7.80317e-003, A6 = -4.98890e-001, A8 = 2.91586e + 000, A10 = -1.08446e + 001,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s5 *
K = 1.81064e + 001,
A4 = -9.47022e-002, A6 = 1.87314e-001, A8 = -2.36577e-001, A10 = 1.57776e + 000,
A12 = -8.52434e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s8 *
K = -2.12261e + 001,
A4 = -2.82843e-001, A6 = 4.62668e-001, A8 = -7.89735e-002, A10 = -7.22225e-002,
A12 = -8.06610e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
S9 *
K = -3.33106e-001,
A4 = -5.97928e-001, A6 = 3.44574e-001, A8 = -2.30062e-003, A10 = -5.09403e-002,
A12 = 1.15280e-002, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
S12 *
K = -9.33450e + 000,
A4 = -2.29975e-001, A6 = 1.12452e-001, A8 = -4.12186e-002, A10 = 1.14282e-002,
A12 = -1.39461e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000

[Example 3]
f [all] 2.892
f [BK1] 2.541
f [BK2] -9.153
f [BK3] -35.240
Fno. 2.880
ω 31.527
Y '1.782
TL 3.135
BF 0.802

si rd nd vd
1 * 1.113 0.168 1.69350 53.20
2 # infinity 0.300 1.47400 56.40
3 infinity 0.050 1.55000 32.00
4 * 1.897 0.357
5 * -2.352 0.050 1.55000 32.00
6 infinity 0.300 1.47400 56.40
7 infinity 0.134 1.52000 57.00
8 * -4.491 0.370
9 * 1.585 0.166 1.52000 57.00
10 infinity 0.300 1.47400 56.40
11 infinity 0.138 1.52000 57.00
12 * 1.266 0.467
13 infinity 0.300 1.51633 64.14
14 infinity 0.137
15 infinity

s1 *
K = 4.81252e-001
A4 = -8.46713e-002, A6 = 4.42939e-001, A8 = -2.42173e + 000, A10 = 3.67714e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s4 *
K = 6.25290e + 000,
A4 = -1.06694e-001, A6 = -9.16678e-001, A8 = 3.32842e + 000, A10 = -1.39051e + 001,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s5 *
K = 1.68000e + 001,
A4 = -7.19030e-002, A6 = -6.43093e-001, A8 = 1.47488e + 000, A10 = 6.93178e + 000,
A12 = -3.47592e + 001, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s8 *
K = -2.89666e + 001,
A4 = -3.54705e-001, A6 = 5.04362e-001, A8 = 4.52042e-002, A10 = -8.94817e-002,
A12 = -1.21045e-001, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s9 *
K = -6.04152e-001,
A4 = -6.00377e-001, A6 = 3.40918e-001, A8 = -4.90848e-003, A10 = -5.14114e-002,
A12 = 1.22341e-002, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s12 *
K = -5.11406e + 000,
A4 = -2.46760e-001, A6 = 1.03749e-001, A8 = -4.08545e-002, A10 = 1.19155e-002, A12 = -1.14274e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000

[Example 4]
f [all] 1.854
f [BK1] 1.428
f [BK2] -2.253
Fno. 2.880
ω 29.935
Y '1.100
TL 1.925
BF 0.425

si rd nd vd
1 * 0.599 0.160 1.52000 57.00
2 # infinity 0.300 1.47400 56.40
3 infinity 0.050 1.55000 32.00
4 * 2.303 0.352
5 * -1.991 0.089 1.55000 32.00
6 infinity 0.300 1.47400 56.40
7 infinity 0.250 1.82115 24.06
8 * 5.438 0.153
9 infinity 0.300 1.47400 56.40
10 infinity 0.069
11 infinity

s1 *
K = -1.20563e-001,
A4 = -1.22511e-001, A6 = 1.85519e + 000, A8 = -6.25197e + 000, A10 = -9.26492e + 001,
A12 = 1.32976e + 002, A14 = 8.25087e + 003, A16 = -8.62144e + 003, A18 = -2.02812e + 005,
A20 = -6.47024e + 004
s4 *
K = 2.66164e + 001,
A4 = -3.82483e-002, A6 = -5.61625e + 000, A8 = 9.59873e + 001, A10 = -1.03725e + 002,
A12 = -9.08830e + 003, A14 = 3.71547e + 004, A16 = 1.25060e + 005, A18 = -1.10524e + 005,
A20 = -1.30788e + 006
s5 *
K = 6.34011e + 000,
A4 = -1.69688e + 000, A6 = -4.64079e + 000, A8 = -1.05807e + 002, A10 = 5.63832e + 002,
A12 = -6.54467e + 002, A14 = -1.74308e + 004, A16 = 1.79836e + 005, A18 = 5.85012e + 005,
A20 = -1.09295e + 007
s8 *
K = -2.25159e + 001,
A4 = -3.99296e-001, A6 = -1.45561e-001, A8 = -4.12123e-001, A10 = 1.76460e + 000,
A12 = -7.36025e-001, A14 = -2.06278e + 000, A16 = 1.00620e + 000, A18 = 1.68861e + 000,
A20 = -1.09532e + 000

[Example 5]
f [all] 3.695
f [BK1] 2.731
f [BK2] -3.806
f [BK3] 3.346
f [BK4] -2.958
Fno. 2.470
ω 31.879
Y '2.354
TL 4.332
BF 0.709

si rd nd vd
1 * 1.626 0.248 1.52000 57.00
2 # infinity 0.400 1.47400 56.40
3 infinity 0.111 1.52000 57.00
4 * -9.387 0.117
5 * 26.887 0.051 1.52000 57.00
6 infinity 0.400 1.47400 56.40
7 infinity 0.078 1.63550 23.00
8 * 2.237 0.364
9 * 154.758 0.051 1.52000 57.00
10 infinity 0.400 1.47400 56.40
11 infinity 0.300 1.52000 57.00
12 * -1.757 0.480
13 * -9.866 0.063 1.52000 57.00
14 infinity 0.400 1.47400 56.40
15 infinity 0.161 1.52000 57.00
16 * 1.862 0.477
17 infinity 0.300 1.51633 64.14
18 infinity 0.033
19 infinity

s1 *
K = -1.52692e-001,
A4 = -8.35933e-003, A6 = 1.87627e-002, A8 = -3.15654e-002, A10 = 0.00000e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s4 *
K = -2.69077e + 001,
A4 = -3.83769e-002, A6 = -7.60393e-003, A8 = -1.46442e-002, A10 = 0.00000e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s5 *
K = -3.00000e + 001,
A4 = -9.46707e-002, A6 = -2.99656e-002, A8 = 7.02903e-002, A10 = -1.99546e-002,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s8 *
K = 7.71871e-002,
A4 = -4.30880e-002, A6 = 1.39855e-002, A8 = -2.10002e-002, A10 = 4.03360e-002,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s9 *
K = 3.00000e + 001,
A4 = 4.40707e-005, A6 = -1.49922e-002, A8 = 1.51644e-002, A10 = -2.29754e-002,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s12 *
K = -8.26796e + 000,
A4 = -9.74831e-002, A6 = 8.10669e-002, A8 = -1.89838e-003, A10 = 3.74246e-003,
A12 = -4.35185e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s13 *
K = 2.87169e + 001,
A4 = -1.34291e-001, A6 = 4.33820e-002, A8 = 2.26107e-002, A10 = -1.20573e-002,
A12 = 1.56751e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s16 *
K = -7.21907e + 000,
A4 = -8.99635e-002, A6 = 3.41522e-002, A8 = -1.24440e-002, A10 = 2.57011e-003,
A12 = -2.03166e-004, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000

[Comparison example]
f [all] 2.782
f [BK1] 2.334
f [BK2] -4.217
f [BK3] 17.527
Fno. 2.880
ω 32.715
Y '1.782
TL 3.075
BF 0.644

si rd nd vd
1 * 0.820 0.233 1.52000 57.00
2 # infinity 0.300 1.47400 56.40
3 infinity 0.050 1.55000 32.00
4 * 2.017 0.369
5 * -2.302 0.113 1.55000 32.00
6 infinity 0.300 1.47400 56.40
7 infinity 0.250 1.52000 57.00
8 * -324.731 0.151
9 * 1.397 0.250 1.52000 57.00
10 infinity 0.300 1.47400 56.40
11 infinity 0.114 1.52000 57.00
12 * 1.377 0.369
13 infinity 0.300 1.51633 64.14
14 infinity 0.077
15 infinity

s1 *
K = 3.73152e-001,
A4 = -9.68164e-002, A6 = 3.72196e-001, A8 = -1.99063e + 000, A10 = 2.40355e + 000,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s4 *
K = 1.09740e + 001,
A4 = 1.20631e-001, A6 = -5.65709e-001, A8 = 2.05594e + 000, A10 = -3.08693e-001,
A12 = 0.00000e + 000, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s5 *
K = 1.58738e + 001,
A4 = 2.49412e-002, A6 = -1.24422e + 000, A8 = 1.21845e + 000, A10 = 6.70729e + 000,
A12 = -2.42298e + 001, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s8 *
K = 3.00000e + 001,
A4 = -4.03455e-001, A6 = 2.86939e-001, A8 = -2.11221e-002, A10 = -5.88122e-002,
A12 = 5.25114e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s9 *
K = -7.95379e-001,
A4 = -6.14020e-001, A6 = 3.36619e-001, A8 = -6.97994e-003, A10 = -5.17831e-002,
A12 = 1.27885e-002, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000
s12 *
K = -2.46781e + 000,
A4 = -2.46795e-001, A6 = 9.87225e-002, A8 = -3.89304e-002, A10 = 1.15247e-002,
A12 = -1.37518e-003, A14 = 0.00000e + 000, A16 = 0.00000e + 000, A18 = 0.00000e + 000,
A20 = 0.00000e + 000

[■ About aberrations related to imaging lenses]
The aberrations relating to the imaging lenses LN of Examples 1 to 5 and the comparative example are shown in FIGS. 7A to 12C. In the aberration diagram, spherical aberration (LONGITUDINAL SPHERICAL ABER.), Astigmatism (ASTIGMATIC FIELD CURVES), and distortion (DISTORTION) are shown.

  The spherical aberration diagram shows the amount of spherical aberration for the d-line (wavelength 587.56 nm), the amount of spherical aberration for the C-line (wavelength 656.28 nm), and the amount of spherical aberration for the g-line (wavelength 435.84 nm), respectively. The amount of deviation [unit: mm] in the optical axis AX direction is indicated. In addition, the vertical axis in the spherical aberration diagram indicates a value obtained by normalizing the incident height to the pupil by the maximum height (that is, the relative pupil height). In addition, refer to each figure for the line types indicating the d-line, C-line, and g-line.

  The astigmatism diagram shows the tangential image plane with respect to the d-line and the sagittal image plane with respect to the d-line in terms of the deviation [unit: mm] in the optical axis AX direction from the paraxial image plane. The line labeled “T” corresponds to the tangential image plane, and the line labeled “S” corresponds to the sagittal image plane. The vertical axis in the astigmatism diagram is the image height (IMG HT) [unit: mm].

  In the distortion diagram, the horizontal axis indicates distortion [unit;%] with respect to the d-line, and the vertical axis indicates image height [unit; mm]. The image height corresponds to the maximum image height Y ′ (half the diagonal length of the light receiving surface SS of the image sensor SR) on the imaging surface.

[■ Details of imaging lens]
The details of the above imaging lens LN are as follows.

  The imaging lens LN includes a lens block BK. The lens block BK is mass-produced at a low cost as described above. In this production, in order to increase the choice of materials, for example, in order to be able to select a material that is easy to process or an inexpensive material (to produce a simple and low-cost imaging lens LN), the lens block BK is a lens substrate. LS and a lens L formed of a resin different from the material of the lens substrate LS (the lens substrate LS may be a resin or glass).

  In addition, as shown in FIGS. 15B and 15C, the imaging lens LN is arranged between the lens block units UT in which a large number of lenses L molded on the lens substrate LS are arranged via the spacer member B1, and further to the sensor cover. After connecting the possible substrate B2, it is manufactured by cutting along the spacer member B1.

  Therefore, if the lens substrate LS is a parallel plate, not only the processing for the lens substrate LS is simplified or unnecessary in the manufacturing process of the imaging lens LN, but also the lens L is formed on the substrate plane, so that the lens substrate LS is stable. Therefore, the parallel flat lens substrate LS reduces the manufacturing burden of the imaging lens LN.

  Furthermore, when the lens substrate LS is a parallel plate, the boundary surface between the substrate surface and the lens L has no power. For this reason, for example, the surface accuracy of the lens substrate LS on the substrate surface hardly affects the focus position on the image surface of the imaging lens LN. Therefore, the imaging lens LN has high performance.

  In particular, if the thickness of the parallel flat plates used as the lens substrate LS is the same, the polishing conditions for the lens substrate LS are the same in the manufacturing process of the imaging lens LN, and the lens substrate LS is manufactured in large quantities at low cost. As a result, the cost of the imaging lens LN is reduced.

  In the imaging lens LN, the following conditional expression (A1) is satisfied. This conditional expression (A1) indicates that at least one lens L in the imaging lens LN has a relatively high refractive index (Nd [L]). The lens L that satisfies the following conditional expression (A1) may be referred to as a specific lens L.

1.61 ≦ Nd [L] (A1)
However,
Nd [L]: Refractive index of the resin that becomes the lens (specific lens) L with respect to the d-line.

  In this case, the thickness of the lens L is relatively thin due to the resin having a relatively high refractive index. For example, using the comparative example and the example 3 in detail, in the comparative example, the first lens L1 is formed of a resin having a refractive index of 1.52 and has a thickness of 0.233 mm. The first lens L1 is made of a resin having a refractive index of 1.69 and has a thickness of 0.168 mm.

  That is, although the first lens L1 of the comparative example and the third embodiment has substantially the same power, the thickness of the first lens L1 of the third embodiment is about 70% of the thickness of the first lens L1 of the comparative example. {Note that in the above, the first lens L1 that is an object-side convex plano-convex lens has been described as an example. }.

  If the thin lens L is formed of a resin (energy curable resin) that is cured by energy such as heat or ultraviolet rays, the energy required for curing is uniformly applied to the entire thin lens L. Therefore, the lens L is uniformly cured as a whole and does not include curing unevenness. When such uneven curing is not included in the lens L, the curvature distribution in the lens L is uniform, and the quality of the lens L is improved (in short, a homogeneous lens as designed is completed).

  Furthermore, if the lens L has a relatively high refractive index, the lens L itself is thinned, thereby shortening the overall length of the imaging lens LN. Further, if the lens L has a relatively high refractive index, the lens L tends to have a relatively high power even if it is thin. Therefore, for example, the lens blocks BK may be located relatively densely, thereby shortening the overall length of the imaging lens LN. Of course, the entire length of the imaging lens LN may be shortened by making the lens L itself thin and the lens blocks BK being positioned relatively densely.

Of the conditional ranges of conditional expression (A1), it is desirable that conditional expression (A1a) that defines the following conditional ranges is satisfied, and more desirably, conditional expression (A1b) is satisfied. This is because, when such a condition is satisfied, a higher quality lens L is formed, and the entire length of the imaging lens LN is shortened.
1.64 ≦ Nd [L] (A1a)
1.69 ≦ Nd [L] (A1b)

  By the way, examples of such a high refractive index resin include polymethyl methacrylate [Nd = 1.50], polycarbonate [Nd = 1.59], polystyrene [Nd = 1.59], di (meta). ) Acrylates. These resins are generally known, and among them, those having a high refractive index, transparency and impact resistance are used for transparent films, optical lenses and the like.

  Further, resins containing sulfur atoms as disclosed in JP-A-62-195357 and JP-A-60-199016, and JP-A-59-87123 and JP-A-59-87126 It is also known that a resin containing an aromatic group as disclosed in a gazette has a high refractive index {note that the refractive index (Nd) of a resin containing a sulfur atom is about 1.60} .

  Furthermore, in recent years, as disclosed in JP-A-5-178929, by using a pyridine derivative as a raw material, it is transparent, has a high refractive index [Nd = 1.66 to 1.79], and has high impact resistance. Excellent resins have also been developed.

  In some of these resins, the degree of color dispersion increased due to the relatively high refractive index. However, when a technique of co-adding various metal ions to a rare earth element such as La (lanthanum) as disclosed in Japanese Patent Laid-Open No. 2007-178921 is adopted, both high refractive index and low dispersion are achieved. An optical resin (an optical resin using rare earth-metal nanoclusters) is generated. With such a resin, the problem of increased chromatic dispersion is solved.

  In addition, the above resin is an example employable as a material of the specific lens L, and is not limited thereto. Therefore, resins other than these and resins made by other methods can be used as the material for the specific lens L.

  Next, the lens substrate LS in the imaging lens LN will be described. Although the imaging lens LN includes a plurality of lens substrates LS, it is desirable that at least one of the lens substrates LS satisfies the following conditional expression (A2). This conditional expression (A2) indicates that the lens substrate LS has a relatively high refractive index. A lens substrate LS that satisfies the following conditional expression (A2) may be referred to as a specific lens substrate LS.

1.58 ≦ Nd [LS] (A2)
However,
Nd [LS]: The material that becomes the lens substrate (specific lens substrate) LS is present for the d-line.
Is the refractive index.

  In general, the lens substrate LS formed of a material having a high refractive index tends to be thin (plate thickness) (for example, formed of a material having a high refractive index out of two lens substrates having the same air-converted optical path length). The thickness of the lens substrate is smaller than the thickness of the lens substrate formed of a low refractive index material). Therefore, the overall length of the imaging lens LN including the lens substrate LS formed of a material that satisfies the conditional expression (A2) is shortened.

  In addition, the total length of the imaging lens LS using the lens substrate LS made of a high refractive index material is the same as the total length of the imaging lens LS adopting the lens substrate LS made of a low refractive index material, although it can be shortened. It may be.

  This is because, by adopting the lens substrate LS made of a high refractive index material, the length that can be shortened can be assigned to the shape of another optical element (lens L or the like). For example, even when the lens L has to be relatively thick for aberration correction, the entire length of the imaging lens LN is unlikely to be long because the lens substrate LS is relatively thin.

  Of course, by adopting a relatively thin lens substrate LS made of a high refractive index material, a certain amount of the thickness of the lens L can be secured for aberration correction while suppressing the increase in the imaging lens LN. Good. In short, when the conditional expression (A2) is satisfied, a balance between a relatively high aberration correction capability and a relatively short total length in the imaging lens LN can be achieved.

Of the conditional ranges of conditional expression (A2), it is desirable that conditional expression (A2a) that defines the following conditional ranges is satisfied. This is because, if such a condition is satisfied, the imaging lens LN that further balances the aberration correction capability and the overall length is completed.
1.66 ≦ Nd [LS] (A2a)

  In the imaging lens LN, it is desirable that at least one lens L among the lenses (specific lenses) L satisfying the conditional expression (A1) is an aspherical lens surface in contact with air.

  Usually, the difference between the refractive index of air and the refractive index of the resin of the specific lens L is relatively large. For this reason, if the lens surface in contact with air is aspherical, aberrations are efficiently corrected. In other words, the effect of the aspheric surface appears to the maximum. Of course, the occurrence of various aberrations is suppressed only by the presence of an aspheric lens surface in the imaging lens LN, and the imaging lens LN has high performance (for example, high aberration correction capability).

  In particular, as shown in FIGS. 13A and 13B in which the paraxial curvature PX is also shown, it is desirable that the aspherical surface has a shape that weakens the peripheral power of the lens L.

  If it becomes like this, the lens L becomes thin by the shape of a periphery, making the power near optical axis AX the same level as the power near optical axis AX calculated from paraxial curvature PX. In addition, if the thinned lens L is formed of a resin that is cured by energy such as heat or ultraviolet rays, the energy required for curing is uniformly applied to the entire thin lens L. Therefore, the lens L is a homogeneous lens as designed without curing unevenness.

  In the imaging lens LN, it is preferable that the following conditional expression (A3) is satisfied. This conditional expression (A3) is obtained by normalizing the focal length of the specific lens L with the focal length of the entire imaging lens LN system.

0.4 ≦ | f [L] / f [all] | ≦ 1.1 (A3)
However,
f [L]: When it is assumed that the object side lens surface and the image side lens surface are in contact with air
The focal length f [all] at the specific lens L in FIG. 5 is the focal length of the entire imaging lens LN system.

  When the value of conditional expression (A3) is lower than the lower limit value, for example, the focal length of the specific lens L is relatively short, and the power of the specific lens L becomes strong. Therefore, although the entire length of the imaging lens LN tends to be shortened, various aberrations are likely to occur due to the strong power.

  On the other hand, when the value of conditional expression (A3) exceeds the upper limit value, for example, the focal length of the specific lens L is relatively long, and the power of the specific lens L becomes weak. Therefore, although various aberrations due to power are less likely to occur, the entire length of the imaging lens LN tends to be long.

  From the above, if the value of conditional expression (A3) falls within the range from the lower limit value to the upper limit value, the power of the specific lens L is not excessively strong, and the imaging lens LN is relatively compact while suppressing various aberrations. Become.

Of the conditional ranges of conditional expression (A3), it is desirable that conditional expression (A3a) that defines the following conditional ranges is satisfied, and more desirably, conditional expression (A3b) is satisfied. This is because, if such a condition is satisfied, the imaging lens LN becomes relatively compact while suppressing various aberrations.
0.4 ≦ | f [L] / f [all] | ≦ 0.8 (A3a)
0.4 ≦ | f [L] / f [all] | ≦ 0.6 (A3b)

  The imaging lens LN preferably satisfies the following conditional expression (A4). This conditional expression (A4) is the difference between the refractive index of the resin that becomes the specific lens L with respect to the d-line and the refractive index of the material that becomes the lens substrate LS connected to the specific lens L with respect to the d-line (however, , Absolute value), which indicates that the difference in refractive index between the specific lens L and the lens substrate LS connected thereto is relatively small.

| Nd [L] −Nd [LS-L] | ≦ 0.25 (A4)
However,
Nd [L]: Refractive index of resin for specific lens L with respect to d-line Nd [LS-L]: Material for lens substrate LS connected to specific lens L with respect to d-line
It has a refractive index.

  Usually, light hardly reflects at the boundary surface between optical elements having a small difference in refractive index. Therefore, if the refractive index difference between the specific lens L and the lens substrate LS connected to the specific lens L (whether the specific lens substrate LS or the non-specific lens substrate LS) is small by satisfying the conditional expression (A4), Light is not easily reflected even at the interface between optical elements. If reflection at the boundary surface is difficult to occur, a ghost-like phenomenon caused by reflected light from the boundary surface is less likely to occur.

Of the conditional ranges of conditional expression (A4), it is desirable that conditional expression (A4a) that defines the following conditional range is satisfied, and more desirably, conditional expression (A4b) is satisfied. This is because, if such a condition is satisfied, reflected light that becomes a ghost is less likely to be generated in the imaging lens LN.
| Nd [L] −Nd [LS-L] | ≦ 0.15 (A4a)
| Nd [L] −Nd [LS-L] | ≦ 0.10 (A4b)

  Needless to say, embodiments obtained by appropriately combining the above conditional expressions (A1) to (A4) are also included in the technical scope of the present invention.

  Incidentally, in the lens block BK in the imaging lens LN, it is desirable that the lens L and the lens substrate LS are indirectly bonded via an optical thin film (for example, an antireflection film, an infrared cut filter, and an aperture stop #). For example, it is desirable that the lens L is adhered to the antireflection film after the antireflection film that suppresses reflection generated at the boundary surface between the lens L and the lens substrate LS is formed on the lens L.

  In this case, the presence of the antireflection film not only increases the light use efficiency but also suppresses stray light. Further, in the imaging lens LN, another member such as an infrared cut filter that is not included in the lens block BK is eliminated. Therefore, the configuration of the imaging lens LN is simplified and the cost is further reduced. In short, it is desirable that an optical thin film is interposed between the lens L and the lens substrate LS in the lens block BK, and the lens L is in direct contact or indirect contact with the optical thin film.

  In addition, in the lens block BK in the imaging lens LN, it is desirable that the lens L and the lens substrate LS are indirectly bonded via an adhesive.

  With this configuration, the lens block BK is completed even if the adhesiveness of the resin that becomes the lens L and the adhesiveness of the material that becomes the lens substrate LS are low. In addition, the number of selections for connecting the lens L and the lens substrate LS increases. For example, direct bonding or indirect bonding can be selected by giving priority to the optical characteristics of the imaging lens LN. Therefore, it is easy to complete a high-performance imaging lens LN.

  In addition, the result of conditional expression (A1-A4) in an Example (EX) is shown below. However, “◯” means that the conditional expression is satisfied, and “×” means that the conditional expression is not satisfied. Note that the numbers given to L of Nd [L] and f [L] indicate the first lens L1 to the eighth lens L8. In addition, the numerals attached to LS of Nd [LS] indicate the first lens substrate LS1 to the fourth lens substrate LS4. Of course, the numbers given to L and LS of Nd [LS-L] also indicate the first lens L1 to the eighth lens L8 and the first lens substrate LS1 to the fourth lens substrate LS4.

[● Example 1]
Regarding conditional expression (A1): The lens corresponding to (O) is a specific lens.
Nd [L1] = 1.69350 (○)
Nd [L2] = 1.67595 (○)
Nd [L3] = 1.72624 (○)
Nd [L4] = 1.60366 (×)
Nd [L5] = 1.48787 (×)
Nd [L6] = 1.75520 (○)
Regarding conditional expression (A2): The lens substrate corresponding to (◯) is the specific lens substrate.
Nd [LS1] = 1.62889 (○)
Nd [LS2] = 1.48749 (×)
Nd [LS3] = 1.48996 (×)
・ Regarding conditional expression (A3) | f [L1] / f [all] | = 0.47 (○)
｜ f [L2] / f [all] | = 0.84 (○)
｜ f [L3] / f [all] | = 1.13 (×)
｜ f [L4] / f [all] | = 1.56 * Because the fourth lens L4 is a non-specific lens (×)
| F [L5] / f [all] | = 1.51 * Because the fifth lens L5 is a non-specific lens (×)
｜ f [L6] / f [all] | = 0.67 (○)
・ Regarding conditional expression (A4) | Nd [L1] -Nd [LS1-L1] | = 0.065 (○)
| Nd [L2] -Nd [LS1-L2] | = 0.047 (○)
| Nd [L3] -Nd [LS2-L3] | = 0.239 (○)
| Nd [L4] -Nd [LS2-L4] | = 0.116 * Because the fourth lens L4 is a non-specific lens (×)
| Nd [L5] -Nd [LS3-L5] | = 0.002 * Because the fifth lens L5 is a non-specific lens (×)
| Nd [L6] -Nd [LS3-L6] | = 0.265 (×)

[● Example 2]
Regarding conditional expression (A1): The lens corresponding to (O) is a specific lens.
Nd [L1] = 1.69350 (○)
Nd [L2] = 1.68247 (○)
Nd [L3] = 1.74377 (○)
Nd [L4] = 1.58016 (×)
Nd [L5] = 1.48896 (×)
Nd [L6] = 1.73627 (○)
Regarding conditional expression (A2): The lens substrate corresponding to (◯) is the specific lens substrate.
Nd [LS1] = 1.68025 (○)
Nd [LS2] = 1.48749 (×)
Nd [LS3] = 1.53228 (x)
・ Regarding conditional expression (A3) | f [L1] / f [all] | = 0.46 (○)
｜ f [L2] / f [all] | = 0.81 (○)
｜ f [L3] / f [all] | = 1.09 (○)
| F [L4] / f [all] | = 1.62 * Because the fourth lens L4 is a non-specific lens (×)
｜ f [L5] / f [all] | = 1.46 * Because the fifth lens L5 is a non-specific lens (×)
｜ f [L6] / f [all] | = 0.76 (○)
・ Regarding conditional expression (A4) | Nd [L1] -Nd [LS1-L1] | = 0.013 (○)
| Nd [L2] -Nd [LS1-L2] | = 0.002 (○)
| Nd [L3] -Nd [LS2-L3] | = 0.256 (×)
| Nd [L4] -Nd [LS2-L4] | = 0.093 * Because the fourth lens L4 is a non-specific lens (×)
| Nd [L5] -Nd [LS3-L5] | = 0.043 * Because the fifth lens L5 is a non-specific lens (×)
| Nd [L6] -Nd [LS3-L6] | = 0.204 (○)

[● Example 3]
Regarding conditional expression (A1): The lens corresponding to (O) is a specific lens.
Nd [L1] = 1.69350 (○)
Nd [L2] = 1.55000 (×)
Nd [L3] = 1.55000 (×)
Nd [L4] = 1.52000 (×)
Nd [L5] = 1.52000 (×)
Nd [L6] = 1.52000 (×)
Regarding conditional expression (A2): The lens substrate corresponding to (◯) is the specific lens substrate.
Nd [LS1] = 1.47400 (×)
Nd [LS2] = 1.47400 (×)
Nd [LS3] = 1.47400 (×)
・ Regarding conditional expression (A3) | f [L1] / f [all] | = 0.55 (○)
| F [L2] / f [all] | = 1.19 * Because the second lens L2 is a non-specific lens (×)
| F [L3] / f [all] | = 1.48 * Because the third lens L3 is a non-specific lens (×)
｜ f [L4] / f [all] | = 2.99 * Because the fourth lens L4 is a non-specific lens (×)
| F [L5] / f [all] | = 1.05 * Because the fifth lens L5 is a non-specific lens (×)
| F [L6] / f [all] | = 0.84 * Since the sixth lens L6 is a non-specific lens (×)
・ Regarding conditional expression (A4) | Nd [L1] -Nd [LS1-L1] | = 0.220 (○)
| Nd [L2] -Nd [LS1-L2] | = 0.076 * Because the second lens L2 is a non-specific lens (×)
| Nd [L3] -Nd [LS2-L3] | = 0.076 * Because the third lens L3 is a non-specific lens (×)
| Nd [L4] -Nd [LS2-L4] | = 0.046 * Because the fourth lens L4 is a non-specific lens (×)
| Nd [L5] -Nd [LS3-L5] | = 0.046 * Because the fifth lens L5 is a non-specific lens (×)
| Nd [L6] -Nd [LS3-L6] | = 0.046 * Since the sixth lens L6 is a non-specific lens (×)

[● Example 4]
Regarding conditional expression (A1): The lens corresponding to (O) is a specific lens.
Nd [L1] = 1.52000 (×)
Nd [L2] = 1.55000 (×)
Nd [L3] = 1.55000 (×)
Nd [L4] = 1.82115 (○)
Regarding conditional expression (A2): The lens substrate corresponding to (◯) is the specific lens substrate.
Nd [LS1] = 1.47400 (×)
Nd [LS2] = 1.47400 (×)
Conditional expression (A3) | f [L1] / f [all] | = 0.62 * Because the first lens L1 is a non-specific lens (×)
| F [L2] / f [all] | = 2.26 * Because the second lens L2 is a non-specific lens (×)
| F [L3] / f [all] | = 1.95 * Because the third lens L3 is a non-specific lens (×)
｜ f [L4] / f [all] | = 3.57 (×)
・ Regarding conditional expression (A4) | Nd [L1] -Nd [LS1-L1] | = 0.046 * Because the first lens L1 is a non-specific lens (×)
| Nd [L2] -Nd [LS1-L2] | = 0.076 * Because the second lens L2 is a non-specific lens (×)
| Nd [L3] -Nd [LS2-L3] | = 0.076 * Because the third lens L3 is a non-specific lens (×)
｜ Nd [L4] −Nd [LS2-L4] | = 0.347 (×)
[● Example 5]
Regarding conditional expression (A1): The lens corresponding to (O) is a specific lens.
Nd [L1] = 1.52000 (×)
Nd [L2] = 1.52000 (×)
Nd [L3] = 1.52000 (×)
Nd [L4] = 1.63550 (○)
Nd [L5] = 1.52000 (×)
Nd [L6] = 1.52000 (×)
Nd [L7] = 1.52000 (×)
Nd [L8] = 1.52000 (×)
Regarding conditional expression (A2): The lens substrate corresponding to (◯) is the specific lens substrate.
Nd [LS1] = 1.47400 (×)
Nd [LS2] = 1.47400 (×)
Nd [LS3] = 1.47400 (×)
Nd [LS4] = 1.47400 (×)
・ Regarding conditional expression (A3) | f [L1] / f [all] | = 0.85 * Because the first lens L1 is a non-specific lens (×)
| F [L2] / f [all] | = 4.89 * Because the second lens L2 is a non-specific lens (×)
| F [L3] / f [all] | = 13.99 * Since the third lens L3 is a non-specific lens (×)
｜ f [L4] / f [all] | = 0.95 (○)
| F [L5] / f [all] | = 80.54 * Because the fifth lens L5 is a non-specific lens (×)
| F [L6] / f [all] | = 0.91 * Since the sixth lens L6 is a non-specific lens (×)
| F [L7] / f [all] | = 5.13 * Since the seventh lens L7 is a non-specific lens (×)
｜ f [L8] / f [all] | = 0.97 * Because the eighth lens L8 is a non-specific lens (×)
・ Regarding conditional expression (A4) | Nd [L1] -Nd [LS1-L1] | = 0.046 * Because the first lens L1 is a non-specific lens (×)
| Nd [L2] -Nd [LS1-L2] | = 0.046 * Because the second lens L2 is a non-specific lens (×)
| Nd [L3] -Nd [LS2-L3] | = 0.046 * Because the third lens L3 is a non-specific lens (×)
| Nd [L4] -Nd [LS2-L4] | = 0.162 (○)
| Nd [L5] -Nd [LS3-L5] | = 0.046 * Because the fifth lens L5 is a non-specific lens (×)
| Nd [L6] -Nd [LS3-L6] | = 0.046 * Since the sixth lens L6 is a non-specific lens (×)
| Nd [L7] -Nd [LS4-L7] | = 0.046 * Because the fifth lens L5 is a non-specific lens (×)
| Nd [L8] -Nd [LS4-L8] | = 0.046 * Since the sixth lens L6 is a non-specific lens (×)

[Embodiment 2]
A second embodiment will be described. In addition, about the member which has the same function as the member used in Embodiment 1, the same code | symbol is attached and the description is abbreviate | omitted. In this embodiment, the resin forming the lens L will be described.

  The resin is excellent in processability. Therefore, when the lens L enumerated in the first embodiment is formed of a resin, an aspheric lens surface is easily formed with a mold or the like.

  However, usually, when fine particles are mixed in a transparent resin (polymethyl methacrylate or the like), light is scattered in the resin, and the transmittance is lowered. Therefore, it can be said that a resin containing fine particles is not suitable as an optical material.

ただし、
ｎ ：樹脂の屈折率
ｔ ：温度
α ：線膨張係数（なお、ＰＭＭＡの場合、α＝７×１０^-5である）
［Ｒ］ ：分子屈折
である。 Also, the resin changes the refractive index depending on the temperature. For example, the temperature dependence of the refractive index of polymethyl methacrylate (PMMA), that is, the temperature-dependent refractive index change (dn / dt) is obtained by the following Lorentz-Lorentz equation (LL).

However,
n: Refractive index of resin t: Temperature α: Linear expansion coefficient (in the case of PMMA, α = 7 × 10 ⁻⁵ )
[R]: Molecular refraction.

Then, in the case of PMMA, the refractive index change is “−1.2 × 10 ⁻⁴ [/ ° C.]”. This numerical value almost coincides with the actual measurement value. Therefore, when the lens L is formed only from resin (plastic), the refractive index change of the lens L must be dependent on temperature. Moreover, when a lens L is formed by simply mixing fine particles in such a resin, the lens L not only scatters light but also changes the refractive index according to temperature.

  However, recently, it has been found that the resin can be used as an optical material by including appropriately designed fine particles. This is because, in a resin (mixed resin) containing fine particles, light scattering does not occur if the particle size of the fine particles is smaller than the wavelength of the transmitted light beam.

  In addition, if the fine particles are inorganic fine particles, the inorganic fine particles increase the refractive index as the temperature rises. Therefore, in the mixed resin, a decrease in the refractive index of the resin with an increase in temperature and an increase in the refractive index of the inorganic fine particles with an increase in temperature occur simultaneously. Then, both temperature dependencies (refractive index decrease / refractive index increase) are offset, and as a result, the refractive index change of the mixed resin hardly occurs depending on the temperature (for example, the lens L causes a change in the surface shape). The change in refractive index can be suppressed to the same extent as the effect on the position of the paraxial image point due to this).

As an example of the mixed resin described above, inorganic fine particles {child material: aluminum oxide (Al ₂ O ₃ ), lithium niobate (LiNbO ₃ , etc.)} having a maximum length of 30 nm or less are dispersed in the resin (base material). And mixed resin. In such a mixed resin, it is desirable that the refractive index change is suppressed to “8 × 10 ⁻⁵ [/ ° C.].

  Based on the above, when the lens L is formed of a resin (mixed resin) in which inorganic fine particles of 30 nm or less are dispersed, the imaging lens LN including the lens L has high durability against temperature. Further, for example, the ratio of the resin to the inorganic fine particles in the mixed resin, the length of the particle size of the inorganic fine particles (for example, the maximum length is 20 nm or less, more desirably 15 nm or less), the type of the resin serving as the base material, and the child material When the kind of inorganic fine particles to be adjusted is appropriately adjusted, the lens L has a high refractive index. Then, when the lens L is formed with the mixed resin, the imaging lens LN including the lens L becomes compact, or the molding difficulty of the lens L is reduced.

  In addition, when inorganic fine particles are dispersed in the resin, the contribution of the second term of the Lorentz-Lorentz equation (LL) is increased. Further, by strengthening the contribution of the second term, the base resin and Can also have the opposite temperature characteristics. That is, it is possible to design a mixed resin in which the refractive index does not decrease but increases as the temperature increases. Similarly, normally, the mixed resin increases the refractive index by absorbing water, but conversely, it is possible to design a mixed resin that decreases the refractive index.

  That is, the ratio of the inorganic fine particles in the mixed resin may be appropriately changed in order to control the temperature dependency of the refractive index. A plurality of types of nano-sized inorganic fine particles may be mixed with the resin.

  The resin as described above is desirably a curable resin. This is because with such a curable resin, a lens L including an aspheric surface can be easily manufactured by a mold or the like. Further, if the resin has adhesiveness (or if an adhesive is mixed in the resin), the resin lens L is easily bonded to the lens substrate LS. That is, the lens block BK block including the lens substrate LS and the lens L that are directly bonded is easily manufactured.

  Furthermore, it is preferable that the resin as described above has heat resistance. For example, a module (camera module) in which the imaging lens LN and the imaging element SR are integrated is attached to a printed circuit board (circuit board) on which paste-like solder is printed, and then heated (reflow processing). Mounted on the printed circuit board. In particular, such implementation is done by automation. Then, if the lens L is a heat-resistant curable resin, it can withstand the reflow process and is suitable for automation (of course, the lens substrate LS is also preferably a heat-resistant material such as glass).

  Examples of the curable resin include a thermosetting resin that is cured with thermal energy and an ultraviolet (UV) curable resin that is cured with optical energy (such a resin is also referred to as an energy curable resin). ).

  Finally, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 is an optical cross-sectional view of the imaging lens of Example 1. FIG. These are optical sectional views of the imaging lens of Example 2. FIG. These are optical sectional views of the imaging lens of Example 3. These are optical sectional views of the imaging lens of Example 4. These are optical sectional views of the imaging lens of Example 5. These are optical sectional views of an imaging lens of a comparative example. FIG. 4A shows aberration diagrams of the imaging lens of Example 1. (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. FIG. 4A shows aberration diagrams of the imaging lens of Example 2, (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. FIG. 4A shows aberration diagrams of the imaging lens of Example 3. (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. FIG. 4A shows aberration diagrams of the imaging lens of Example 4. (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. FIG. 4A shows aberration diagrams of the imaging lens of Example 5. (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. FIG. 4A shows aberration diagrams of the imaging lens of the comparative example, in which (A) is a spherical aberration diagram, (B) is an astigmatism diagram, and (C) is a distortion aberration diagram. (A) is an optical sectional view of a lens block in which a convex lens and a lens substrate are connected together with a paraxial curvature, and (B) is a lens block in which a concave lens and a lens substrate are combined with a paraxial curvature. It is optical sectional drawing. FIG. 3 is a block diagram of a mobile terminal. (A) is a cross-sectional view of the lens block unit, (B) is a cross-sectional view showing a manufacturing process of the imaging lens, and (C) is a cross-sectional view of the imaging lens.

Explanation of symbols

BK lens block L lens LS lens substrate # aperture stop s lens surface / substrate surface * aspherical PT parallel plate LN imaging lens SR imaging element IM image surface SS light receiving surface AX optical axis LU imaging device CU portable terminal 1 signal processing unit 2 control Section 3 Memory 4 Operation section 5 Display section

Claims (12)

At least one lens block comprising: a lens substrate that is a parallel plate; and a lens having a positive power or a negative power connected to at least one of the object-side substrate surface and the image-side substrate surface of the lens substrate. Included
The lens is formed of a resin different from the material of the lens substrate,
An imaging lens in which at least one of the lenses is a specific lens that satisfies the following conditional expression (A1).
1.61 ≦ Nd [L] (A1)
However,
Nd [L]: Refractive index of the resin serving as the specific lens with respect to the d-line. The imaging lens according to claim 1, wherein at least one of the lens substrates is a specific lens substrate that satisfies the following conditional expression (A2).
1.58 ≦ Nd [LS] (A2)
However,
Nd [LS]: Refractive index of the material to be the specific lens substrate with respect to the d-line.   The imaging lens according to claim 1, wherein at least one of the specific lenses has an aspheric lens surface in contact with air. The imaging lens of any one of Claims 1-3 which satisfy | fills the following conditional expression (A3).
0.4 ≦ | f [L] / f [all] | ≦ 1.1 (A3)
However,
f [L]: When it is assumed that the object side lens surface and the image side lens surface are in contact with air
The focal length of a specific lens at f [all] is the focal length of the entire imaging lens system. The imaging lens of any one of Claims 1-4 which satisfy | fills the following conditional expression (A4).
| Nd [L] −Nd [LS-L] | ≦ 0.25 (A4)
However,
Nd [L]: Refractive index of resin for specific lens with respect to d-line Nd [LS-L]: Material for lens substrate connected to specific lens for d-line
Refractive index.   6. The lens according to claim 1, wherein an optical thin film is interposed between the lens and the lens substrate in the lens block, and the lens is in direct contact or indirect contact with the optical thin film. Imaging lens.   The imaging lens according to claim 1, wherein the resin serving as the lens is an energy curable resin.   The imaging lens according to claim 7, wherein inorganic fine particles having a particle size of 30 nm or less are dispersed in the energy curable resin serving as the lens. The imaging lens according to any one of claims 1 to 8,
An image sensor that images light passing through the imaging lens;
An imaging apparatus including: An imaging device according to claim 9,
A control unit for controlling the imaging operation of the imaging device to at least one of still image shooting and moving image shooting;
Including electronic equipment.   The electronic device according to claim 10 is a portable terminal. In the manufacturing method of the imaging lens of any one of Claims 1-8,
When a unit including a plurality of lens blocks arranged side by side is a lens block unit,
A connecting step of arranging a spacer on at least a part of the periphery of the lens block, and connecting a plurality of the lens block units with the spacer interposed therebetween;
A cutting step of cutting the connected lens block unit along the spacer;
A method for manufacturing an imaging lens.

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