WO2013039034A1 - Imaging lens and imaging device - Google Patents

Abstract

Provided are an imaging lens and an imaging device that uses the imaging lens, the imaging lens being endowed with high performance, low cost, and high manufacturing stability, by ensuring the substrate thickness and sensor cover glass thickness that are necessary to ensure manufacturing stability, which becomes an issue when an imaging lens is adapted to a small-sized imaging device, and by realizing aberration performance whereby high resolution can be achieved even at the edges. An optical element provided with a lens unit having a positive or negative power formed on the object-side surface and/or the image-side surface being referred to as a lens block, the imaging lens comprises: a lens substrate which is a parallel plate; and, in order from the object, a first lens block having a positive power, a convex surface of which facing the object and a concave surface of which facing the image; and a second lens block, a convex surface of which facing the object and a concave surface of which facing the image; an aperture diaphragm being provided on the object side of the first lens block or inside the first lens block; the object-side lens unit of the second lens block having a concave shape at the edge thereof; and the imaging lens satisfying conditions (1) and (2). (1): −3.5 < r12/f(1-N13) < -1.1 (2): 0.5 < D/Σd < 0.65 (r12: paraxial curvature radius (mm) of the image-side surface of the first lens block; f: focal length (mm) of the entire imaging lens system; N13: refractive index of the image-side lens unit of the first lens block; D: distance (mm) on the optical axis from the object-side surface of the first lens block to the object-side surface of the second lens block; Σd: distance (mm) on the optical axis from the object-side surface of the first lens block to the image-side surface of the second lens block)

Description

Imaging lens and imaging apparatus

The present invention relates to an imaging lens suitable for an imaging device using a solid-state imaging device such as a CCD (Charge Coupled Devices) type image sensor or a CMOS (Complementary Meta 1-Oxide Semiconductor) type image sensor, and more specifically, a large quantity. The present invention relates to an imaging lens for an optical system using a wafer scale lens suitable for production, and an imaging apparatus using the imaging lens.

Compact and thin imaging devices are now installed in portable terminals that are compact and thin electronic devices such as mobile phones and PDAs (Persona1 Digita1 Assistants), which enables not only audio information but also image information to remote locations. Can also be transmitted to each other.

As an image pickup element used in these image pickup apparatuses, a solid-state image pickup element such as a CCD type image sensor or a CMOS type image sensor is used. In recent years, the number of pixels of an image sensor has been increased, and higher resolution and higher performance have been achieved. Further, as a lens for forming a subject image on these image pickup elements, a lens formed of a resin suitable for mass production has been used for further cost reduction. In particular, a lens made of resin has good workability and can meet the demand for higher performance by adopting an aspherical shape.

As an imaging lens used in such an imaging device built in a portable terminal, a type having a configuration with three plastic lenses and an optical system having a configuration with three glass lenses, one glass lens and two plastic lenses are generally well known. It has been. However, as demands for further downsizing of these imaging lenses and mass productivity required for portable terminals are becoming stricter, it is becoming more difficult to achieve both.

In order to overcome such problems, a large number of lens elements are simultaneously formed on a glass substrate of several inches which is a parallel plate by a replica method, and a glass substrate (lens wafer) on which a large number of these lens elements are formed is used as a sensor wafer. A method of mass-producing lens modules by combining them with each other has been proposed. The lens manufactured by such a manufacturing method is called a wafer scale lens, and the lens module is called a wafer scale lens module.

In addition to the mass production of lens modules, as a method of mounting lens modules on a board at low cost and in large quantities, in recent years, together with ICs (integrated circuit) chips and other electronic components on boards that have been soldered in advance. A method has been proposed in which an electronic component and a lens module are simultaneously mounted on a substrate by reflow treatment (heating treatment) while the lens module is placed and melting the solder, and the heat resistance can withstand the reflow treatment. There is also a need for excellent imaging lenses. By the way, in order to reduce the size of the imaging device, it is conceivable to make the parallel plate of the lens module thin. However, considering the manufacturing stability, there is a limit to making it thin. On the other hand, since the cover glass of the image sensor needs to have a predetermined thickness to give rigidity, a certain degree of lens back must be secured to avoid interference in the relationship between the image pickup lens and the sensor. There is also a problem that it must not be.

As an imaging lens capable of reducing the size of the imaging element, those shown in Patent Documents 1 and 2 having two lens blocks are proposed. However, the imaging lens described in Patent Document 1 has a large sag amount because the radius of curvature of the side surface of the first lens block image is too small, and can secure a sufficient edge thickness enough to insert a substrate when downsizing. There is no problem. On the other hand, in the imaging lens described in Patent Document 2, the side surface of the second lens block image is too close to the imaging device, and a sufficient lens back for inserting the cover glass of the imaging device (sensor) can be secured when downsizing. There is no problem.

Japanese Patent No. 3929479 US Pat. No. 7,457,053

The present invention has been made in view of such a situation, and secures a substrate thickness and a cover glass thickness of a sensor necessary to ensure manufacturing stability, which becomes a problem when dealing with downsizing of an imaging device. In addition, an object of the present invention is to provide an imaging lens having high performance, low cost, and high manufacturing stability, and an imaging apparatus using the imaging lens by realizing aberration performance capable of achieving high resolution up to the periphery.

In the imaging lens according to claim 1, an optical element including a lens substrate that is a parallel plate and a lens unit that is formed on at least one of the object side surface and the image side surface and has positive or negative power is referred to as a lens block. When starting from the object side, the first lens block having a positive power with the convex surface facing the object side and the concave surface facing the image side, and the second lens block having the convex surface facing the object side and the concave surface facing the image side The aperture stop is provided on the object side of the first lens block or inside the first lens block, the object side lens portion of the second lens block has a concave shape in the periphery, and the following conditional expression is satisfied: It is characterized by satisfying.
−3.5 <r12 / f (1-N13) <− 1.1 (1)
0.5 <D / Σd <0.65 (2)
However,
r12: Paraxial radius of curvature (mm) of the side surface of the first lens block image
f: Focal length (mm) of the entire imaging lens system
N13: Refractive index D of the first lens block image side lens part D: Distance on the optical axis from the first lens block object side surface to the second lens block object side surface (mm)
Σd: distance on the optical axis from the first lens block object side surface to the second lens block image side surface (mm)

According to the present invention, by using a lens block having a two-lens configuration, an imaging lens having a higher performance than a single-lens configuration and a lower profile (shorter overall length) than a three-lens configuration can be obtained. Furthermore, since the object side surfaces of the first lens block and the second lens block are convex toward the object side, the image-side principal point position can be made closer to the object side even at the same focal length, thereby reducing the overall length. This is an advantageous configuration. Further, since the image side surfaces of the first lens block and the second lens block are concave on the image side, aberration can be corrected well and the lens back can be lengthened. Enough space for insertion can be secured. Further, since the object side lens portion of the second lens block has negative power at the periphery, it is possible to share correction of field curvature and astigmatism at the image side surface and the peripheral image height of the first lens block. Therefore, it is possible to reduce the sag amount of the image side surface of the first lens block and the object side surface of the second lens block, which is advantageous for securing the plate thickness of the lens substrate. Further, by arranging the aperture stop on the object side of the first lens block or inside the first lens block, the exit pupil position can be made closer to the object side, so that the telecentric characteristics for the sensor are improved. Note that “the object side lens portion of the second lens block has a concave shape at the periphery” means that the cross section including the optical axis is directed toward the image side as the distance from the optical axis increases, and the object side with the inflection point as a boundary. It means that it is a shape toward.

When the value of conditional expression (1) is less than the upper limit, the sag amount on the side surface of the first lens block image can be reduced, so that the lens substrate in the first lens block can easily have a desired thickness. In addition, since the occurrence of coma aberration can be suppressed, good performance can be achieved. On the other hand, if the value of conditional expression (1) exceeds the lower limit, the Petzval sum can be improved and the field curvature can be corrected well, the lens back can be lengthened, and a cover glass for the sensor is inserted. Sufficient space can be secured.

When the value of conditional expression (2) exceeds the lower limit, the height of light incident on the second lens block is increased, and field curvature and astigmatism are caused by a negative lens around the lens part on the second lens block object side. Since the correction can be performed efficiently, the sag amount on the object side surface of the second lens block can be reduced, so that the lens substrate in the second lens block can easily have a desired thickness. On the other hand, when the value of conditional expression (2) is below the upper limit, the lens back can be lengthened, and a sufficient space for inserting the cover glass of the sensor can be secured. In particular, these do not make the sag amount of the image side surface of the first lens block and the object side surface of the second lens block extremely small, but contribute to the overall miniaturization by reducing the sag amount in a balanced manner. .

The imaging lens according to claim 2 is characterized in that, in the invention according to claim 1, the image side surface of the second lens block has a convex shape in the peripheral portion.

By making the peripheral part of the image side surface of the second lens block convex, the resin thickness in the peripheral part of the image side lens part of the second lens block can be reduced, and good telecentricity is ensured. can do. Note that “the image side surface of the second lens block has a convex shape at the peripheral portion” means that the cross section including the optical axis moves toward the image side as the distance from the optical axis increases, and toward the object side with the inflection point as a boundary. It means that it is a shape.

According to a third aspect of the present invention, there is provided the imaging lens according to the first or second aspect, wherein the first lens block satisfies the following conditional expression.
0.3 <DL1 / f <0.6 (3)
However,
DL1: Distance on the optical axis from the object side surface to the image side surface of the first lens block (mm)

When the distance on the optical axis from the object side surface to the image side surface of the first lens block exceeds the lower limit of the conditional expression (3), the lens substrate in the first lens block has a desired thickness. it can. On the other hand, since the distance from the first lens block to the imaging surface of the sensor can be increased when the distance falls below the upper limit of the conditional expression (3), the thickness of the lens substrate of the second lens block is ensured. It becomes easy.

According to a fourth aspect of the present invention, there is provided the imaging lens according to any one of the first to third aspects, wherein the second lens block satisfies the following conditional expression.
0.7 <r21 / r22 <1.8 (4)
However,
r21: Paraxial radius of curvature (mm) of the object side surface of the second lens block
r22: Paraxial radius of curvature (mm) of the side surface of the second lens block image

The relationship between the paraxial radius of curvature of the second lens block object side surface and the paraxial radius of curvature of the image side surface (the centers of the radii are both on the image side) satisfies the conditional expression (4), whereby the second lens It becomes easy to balance the resin amount of the block object side lens portion and the image side lens portion, and even if the thickness of the lens substrate is reduced, it is difficult to warp, so that the manufacturing stability can be improved.

According to a fifth aspect of the present invention, there is provided the imaging lens according to any one of the first to fourth aspects, wherein the first lens block satisfies the following conditional expression.
0.23 <r11 / r12 <0.6 (5)
However,
r11: paraxial radius of curvature (mm) of the object side surface of the first lens block

The relationship between the paraxial curvature radius of the object side surface of the first lens block and the paraxial curvature radius of the image side surface (the centers of the radii are both on the image side) satisfies the conditional expression (5), whereby the first lens Since the block image side lens unit can have an appropriate negative power, it is possible to secure a sufficient lens back for inserting the cover glass of the sensor even when downsizing, and conditional expression (5) Is less than the upper limit, the sag amount on the image side surface of the first lens block is reduced, and the lens substrate thickness is easily secured.

An imaging lens according to a sixth aspect of the present invention is the imaging lens according to any one of the first to fifth aspects, wherein the opening is provided between the object side lens unit or the image side lens unit and the lens substrate in the first lens block. It has a diaphragm.

By providing the aperture stop between the object side lens unit or the image side lens unit and the lens substrate in the first lens block, the effective surface diameter of the first lens block image side lens unit can be reduced. In addition to easily securing the lens substrate thickness, it is easy to secure the lens back.

According to a seventh aspect of the present invention, there is provided the imaging lens according to the sixth aspect of the present invention, wherein the first lens block is between the object side lens unit or the image side lens unit and the lens substrate, and the aperture stop is There are flare cut stops at different positions, and the flare cut stop satisfies the following conditional expression.
φ0 <L (6)
However,
L: Shortest distance (mm) from the optical axis to the flare cut aperture
φ0: Radius radius (mm) of the axial light beam at the flare-cut stop position

FIG. 20 is a diagram showing a relationship between the aperture stop S and the flare cut stop FS, and each symbol corresponds to each diameter. By providing a flare-cut stop separately from the aperture stop, harmful light due to the effective outside diameter on the object side or the image side surface can be suppressed, and the design freedom of the effective outside diameter can be increased. It becomes easy to secure a desired lens substrate thickness.

More preferably, the following conditional expression is satisfied.
φ0 <L <φ (6) '
However,
φ: Distance (mm) from the passing position of the outer light beam with the maximum image height at the flare-cut stop position (see Fig. to)

When the value L falls below the upper limit of the conditional expression (6) ′, the effective lens length can be further reduced, so that it is easy to secure a desired lens substrate thickness and reduce coma aberration generated off-axis. Can do.

An imaging lens according to an eighth aspect is characterized in that, in the invention according to any one of the first to fifth aspects, the aperture stop is provided closer to the object side than the first lens block.

By providing the aperture stop closer to the object side than the first lens block, the height of the light beam reaching the object side surface of the second lens block can be increased, and the aperture stop is disposed in the periphery of the object side surface of the second lens block. Since the aberration can be corrected more efficiently on the concave surface, the sag amount on the side surface of the second lens block object can be further reduced.

The imaging lens according to claim 9 is the invention according to claim 8, wherein the first lens block has a flare-cut stop between the object side lens unit or the image side lens unit and the lens substrate. The flare cut stop satisfies the following conditional expression.
φ0 <L (6)
However,
L: Shortest distance (mm) from the optical axis to the flare cut aperture
φ0: Radius radius (mm) of the axial light beam at the flare-cut stop position

By providing a flare-cut stop separately from the aperture stop, harmful light due to the effective outside diameter on the object side or the image side surface can be suppressed, and the design freedom of the effective outside diameter can be increased. It becomes easy to secure a desired lens substrate thickness.

More preferably, the following conditional expression is satisfied.
φ0 <L <φ (6) '
However,
φ: Distance (mm) from the passing position of the outer light beam with the maximum image height at the flare-cut stop position (see Fig. to)

When the value L falls below the upper limit of the conditional expression (6) ′, the effective lens length can be further reduced, so that it is easy to secure a desired lens substrate thickness and reduce coma aberration generated off-axis. Can do.

The imaging lens according to claim 10 is characterized in that, in the invention according to any one of claims 1 to 9, the object side and image side lens portions of the second lens block satisfy the following conditional expression: .
20 <ν21 <45 (7)
45 <ν23 <65 (8)
However,
ν21: Abbe number with respect to d-line of the second lens block object side lens portion ν23: Abbe number with respect to d line of the second lens block image side lens portion

When the object side and image side lens portions of the second lens block satisfy the conditional expressions (7) and (8), the lateral chromatic aberration can be corrected efficiently, and high performance can be secured up to the periphery.

An imaging lens according to an eleventh aspect is characterized in that, in the invention according to any one of the first to tenth aspects, the lens substrate is formed of a resin material.

Since the lens substrate in the lens block is made of resin, it is difficult to break, so the total optical length can be reduced.

The imaging lens according to a twelfth aspect is characterized in that, in the invention according to any one of the first to tenth aspects, the lens substrate is made of a glass material.

An imaging lens with excellent optical characteristics can be obtained by making the lens substrate in the lens block glass.

According to a thirteenth aspect of the present invention, in the invention according to any one of the first to twelfth aspects, the imaging lens satisfies the following conditional expression.
0.3 <DCG / Ymax <0.7 (9)
However,
DCG: Maximum thickness of sensor cover glass Ymax: Half the diagonal length of the imaging surface of the solid-state imaging device

Miniaturization can be realized by satisfying the upper limit of the conditional expression. By exceeding the lower limit, a desired substrate thickness can be secured and the production stability of the lens is improved.

The imaging lens according to a fourteenth aspect is characterized in that, in the invention according to any one of the first to thirteenth aspects, the imaging lens satisfies the following conditional expression.
1.9 <TL / Ymax <2.5 (10)
However,
TL: Distance (mm) on the optical axis from the lens surface closest to the object side to the image-side focal point of the entire imaging lens system (however, “image-side focal point” means that parallel rays parallel to the optical axis are incident on the imaging lens. This is the image point when

The strength of CG can be secured by exceeding the lower limit of this conditional expression. By lowering the upper limit, a desired substrate thickness can be secured and the production stability of the lens is improved.

An imaging apparatus according to a fifteenth aspect is characterized by using the imaging lens according to any one of the first to fourteenth aspects.

According to the present invention, an aberration capable of securing a substrate thickness and a sensor cover glass thickness necessary for ensuring manufacturing stability, which is a problem when dealing with downsizing of an imaging device, and achieving high resolution to the periphery. By realizing the performance, it is possible to provide an imaging lens having high performance, low cost, and high manufacturing stability, and an imaging device using the imaging lens.

It is a perspective view of imaging device LU concerning this embodiment. FIG. 2 is a cross-sectional view of the configuration of FIG. 1 cut along an arrow II-II line and viewed in the direction of the arrow, where (a) shows an example of forming an aperture stop, a flare cut stop, and a light shielding part; An example is shown. FIGS. 2A and 2B are diagrams showing a mobile phone T, in which FIG. 1A is a view of the folded mobile phone opened and viewed from the inside, and FIG. 2B is a view of the folded mobile phone opened and viewed from the outside. It is a figure which shows an example of the manufacturing process (a)-(e) of an imaging lens. It is a schematic sectional drawing of the imaging lens manufactured by the manufacturing process of FIG. 1 is a cross-sectional view of an imaging lens according to Example 1. FIG. FIG. 6 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion (c) of the imaging lens according to Example 1; 6 is a cross-sectional view of an imaging lens according to Example 2. FIG. FIG. 6 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion (c) of the imaging lens according to Example 2; 6 is a cross-sectional view of an imaging lens according to Example 3. FIG. FIG. 6 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion aberration (c) of the imaging lens according to Example 3; 6 is a cross-sectional view of an imaging lens according to Example 4. FIG. FIG. 6 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion aberration (c) of the imaging lens according to Example 4; 6 is a cross-sectional view of an imaging lens according to Example 5. FIG. FIG. 10 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion aberration (c) of the imaging lens according to Example 5; 6 is a cross-sectional view of an imaging lens according to Example 6. FIG. FIG. 10 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion (c) of the imaging lens according to Example 6; 10 is a cross-sectional view of an imaging lens according to Example 7. FIG. FIG. 10 is an aberration diagram of spherical aberration (a), astigmatism (b), and distortion (c) of the imaging lens according to Example 7; It is a figure which shows the relationship between the aperture stop S and the flare cut stop FS.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an imaging apparatus LU according to the present embodiment, and FIG. 2 is a cross-sectional view of the configuration of FIG. 1 taken along the line II-II and viewed in the direction of the arrow. Is an example in which an aperture stop, a flare cut stop, and a light shielding part are formed on a substrate with a black resin or resin, and (b) is an aperture stop formed by the central opening of the housing, and a flare cut stop and light shield are made with resin or resin. It is an example which forms a part. As shown in FIG. 2, the imaging device LU of FIG. 1 has a CMOS image sensor IM as a solid-state imaging device having a photoelectric conversion unit IMa, and a subject image on the photoelectric conversion unit (light receiving surface) IMa of the image sensor IM. An imaging lens LN for imaging and an external connection terminal (electrode) (not shown) that transmits and receives the electrical signal are provided, and these are integrally formed.

The imaging lens LN includes a first lens block LB1 and a second lens block LB2 in order from the object side (upper side in FIG. 2). The first lens block LB1 includes a lens substrate PP1 that is a parallel plate, a convex lens portion LB1a formed on the object side surface, and a concave lens portion LB1b formed on the image side surface. The second lens block LB2 includes a lens substrate PP2 which is a parallel plate, a convex lens portion LB2a formed on the object side surface, and a concave lens portion LB2b formed on the image side surface. It is desirable to perform IR cut coating on at least one of both surfaces of the lens substrate PP1 and the lens substrate PP2. By attaching the IR cut coat on both sides, it is possible to prevent warping of the lens substrate.

In the example of FIG. 2A, an aperture stop S is further formed between the lens substrate PP1 and the object side lens unit LB1a, and a flare cut stop FS is formed between the lens substrate PP1 and the image side lens unit LB1b. They are formed in between, but these may be reversed. Alternatively, the aperture stop S may be provided on the object side of the first lens block LB1, and the flare cut stop FS may be provided inside the first lens block LB1. The aperture stop S and the flare cut stop FS can be formed by forming a film on a lens substrate with a resin capable of shielding light such as black. Alternatively, it can be formed by depositing a metal such as Cr or CrO or a metal oxide. The aperture stop S is formed from the effective diameter to the outer periphery of the first lens block LB1, and the flare cut stop FS is formed from a position outside the effective diameter to the outer periphery of the first lens block LB1. On the other hand, the light shielding portion SH may be formed on the lens substrate PP2 of the second lens block LB2 by the same method as the aperture stop. However, the spacer may be a transparent material such as resin or glass, and the light shielding portion SH is formed from a position outside the effective diameter to the inside of the spacers SP1 and SP2. This is because, for example, when a spacer is bonded using a UV curable resin or the like, it is necessary to irradiate ultraviolet rays (UV) around the spacer by irradiating from the outside through the second lens block LB2, and this is not blocked. It is for doing so. This is because in the case of a wafer scale lens, irradiation from the side surface is impossible before cutting the lens substrate.

The object side lens portion LB2a of the second lens block LB2 has a concave shape in the periphery and satisfies the following conditional expression.
−3.5 <r12 / f (1-N13) <− 1.1 (1)
0.5 <D / Σd <0.65 (2)
However,
r12: paraxial radius of curvature of the first lens block image side surface (mm)
f: Focal length (mm) of the entire imaging lens system
N13: Refractive index D of the first lens block image side lens portion D: Distance on the optical axis from the first lens block object side surface to the second lens block object side surface (mm)
Σd: distance on the optical axis from the first lens block object side surface to the second lens block image side surface (mm)

In the image sensor IM, a photoelectric conversion unit IMa as a light receiving unit in which pixels (photoelectric conversion elements) are two-dimensionally arranged is formed in the center of a plane on the light receiving side, and signal processing (not shown) is performed. Connected to the circuit. Such a signal processing circuit includes a drive circuit unit that sequentially drives each pixel to obtain a signal charge, an A / D conversion unit that converts each signal charge into a digital signal, and a signal that forms an image signal output using the digital signal. It consists of a processing unit and the like. A number of pads (not shown) are arranged near the outer edge of the light receiving side plane of the image sensor IM, and are connected to the image sensor IM via wires (not shown). The image sensor IM converts a signal charge from the photoelectric conversion unit IMa into an image signal such as a digital YUV signal and outputs the image signal to a predetermined circuit via a wire (not shown). Here, Y is a luminance signal, U (= RY) is a color difference signal between red and the luminance signal, and V (= BY) is a color difference signal between blue and the luminance signal. Note that the solid-state imaging device is not limited to the CMOS image sensor, and other devices such as a CCD may be used.

The image sensor IM is connected to an external circuit (for example, a control circuit included in a host device of a portable terminal mounted with an imaging device) via an external connection terminal, and a voltage or a clock for driving the image sensor IM from the external circuit. It is possible to receive a signal and to output a digital YUV signal to an external circuit.

The upper part of the image sensor IM is sealed with a cover glass CG. Above the cover glass CG (object side), a spacer SP2 is interposed, and the flange portion (outside of the lens portion) of the second lens block LB2 is fixed at a predetermined distance. Further, on the object side, the spacer SP1 Is interposed, and the flange portion (outside of the lens portion) of the first lens block LB1 is fixed. The outer sides of these lens blocks LB1 and LB2 are covered with a housing BX, and the lower surface of the upper flange BXa of the housing BX is in contact with the upper surface of the flange portion (outside of the lens portion) of the first lens block LB1. The lower end of the housing BX is not in contact with the cover glass CG. The spacers SP1 and SP2 are fixed by alignment and are bonded in the air as will be described later. Therefore, the spacer SP1, the first lens block LB1, and the second lens block LB2 are not applied. Thereby, even if the spacers SP1 and the thickness of the lens substrate vary, the distance between the lenses can be accurately defined. Further, a fine concavo-convex structure can be provided as an antireflection structure between the first lens block LB1 and the second lens block LB2. When these uneven structures are provided on the surface, cleaning becomes difficult if dust adheres to the fine unevenness. However, since the space between the first lens block LB1 and the second lens block LB2 is sealed, dust does not enter and cleaning is not necessary.

On the other hand, in the example of FIG. 2B, the lower surface of the upper flange BXa of the housing BX that covers the entire lens blocks LB1 and LB2 is in close contact with the upper surface except within the effective diameter of the lens portion LB1a of the first lens block LB1. is doing. Here, the central opening of the upper flange BXa constitutes the aperture stop S. However, an aperture stop may be applied and formed on the lens surface with a black resin or the like. The imaging lens LN is held in the housing BX by engaging the outer peripheral lower surface of the lens substrate PP2 of the second lens block LB2 with the convex portion BXb formed on the inner periphery of the housing BX. Therefore, the spacer SP2 is not provided. The lower end of the housing BX is in contact with the upper surface of the cover glass CG. The other configuration is the same as the example shown in FIG.

Next, a mobile phone as an example of a mobile terminal equipped with an imaging device will be described based on the external view of FIG. 3A is a view of the folded mobile phone opened from the inside and FIG. 3B is a view of the folded mobile phone opened from the outside.

In FIG. 3, in the mobile phone T, an upper casing 71 as a case having display screens D1 and D2 and a lower casing 72 having an operation button B are connected via a hinge 73. In the present embodiment, the main imaging device MC for photographing a landscape or the like is provided on the surface side of the upper housing 71, and the imaging device LU including the above-described wide-angle imaging lens LN is the upper housing 71. And provided on the display screen D1.

As shown in FIG. 3A, the imaging lens LN can image the upper body of the user himself holding the mobile phone T with his / her hand, with the imaging device LU facing the imaging device LU. By transmitting the image signal to the mobile phone of the other party that is communicating and displaying the image of this user, a so-called videophone can be realized by making a normal call. The mobile phone T is not limited to a folding type.

Next, a method for manufacturing the imaging lens will be described with reference to the drawings. FIG. 4 is a diagram showing the manufacturing process of the imaging lens, but the lens shape is different from the actual one. First, as shown in FIG. 4A, IR cut coating (described above) is performed on both surfaces of a parallel plate 101 made of glass or resin, and a black resist is applied at equal intervals to form a diaphragm 104 (described above). . The thickness of the parallel plate 101 is about 0.2 to 0.7 mm. If the substrate is thinner than this value, the strength is insufficient and the substrate is damaged and cheap. In particular, a large glass substrate such as a wafer level lens such as a wafer level lens is difficult to handle with a thin lens, so a certain thickness is required. On the other hand, if the thickness is 0.7 mm or more, the entire length is increased only by the thickness of the substrate and it is difficult to reduce the size, so the above range is preferable. The two parallel flat plates preferably have substantially the same thickness, and the total thickness of the two parallel flat plates is preferably within a range of 0.5 to 1.0 mm in view of overall miniaturization. Next, as shown in FIG. 4B, for example, a photocurable resin PL is applied to the lower surface of the parallel plate 101. At this time, each lens may be manufactured by individual dropping. For example, as a method for manufacturing a wafer scale lens, in addition to a method in which a resin is applied to the entire surface of the substrate and the resin is dropped on the entire surface of the lens substrate to be molded (the lenses are connected), the lens unit 1 is formed on the lens substrate. There is a method in which resin is dropped by the number of pieces (or a plurality of pieces), and the molding is repeated individually by repeating the molding. This individual dripping is effective in ensuring lens accuracy, such as having no effect on the lens surface during cutting.

Thereafter, the mold 41 is pressed against the parallel plate 101 on the surface on which the resin PL is applied. Thereafter, if the substrate 101 on the parallel plate side is a transparent member (glass or the like), it is irradiated with light from there to be cured. Conversely, the mold 41 may be made of a transparent material, and in that case, it may be cured by irradiating light from the mold 41 side. Thereafter, a lens for releasing the mold 41 is formed. In the above method, the resin is applied to the parallel flat plate 101 by photo-curing, but the resin may be applied to the mold 41 and molded.

Further, as shown in FIG. 4C, a photo-curable resin PL is applied to the surface of the parallel plate 101 opposite to the lens side formed with the mold 41. Thereafter, the mold 42 is pressed against the parallel plate 101 on the surface on which the resin PL is applied. Thereafter, if the substrate 101 on the parallel plate side is a transparent member (glass or the like), it is irradiated with light from there to be cured. Conversely, the mold 42 may be made of a transparent material, and in that case, it may be cured by irradiating light from the mold 42 side. Thereafter, the mold 41 is released to form a lens. In the above method, the resin is applied to the parallel plate 101 by photo-curing, but the resin may be applied to the mold 41 for molding. In this way, the lens block 100 in which the lens portion 11 is formed on one surface and the lens portion 12 is formed on the other surface as shown in FIG. 4D is completed.

The lens block 100 formed in this manner and the lens block 200 formed in the same manner in another process are finally set to have optical axes OA of the lens portions 11 and 12 as shown in FIG. While being held by a holding device (not shown) so as to be aligned, the spacer 105 inserted between the two is adsorbed to the holding device.

Next, a UV adhesive 106 (see FIG. 5) is applied to the upper end of the spacer 105. Application of the UV adhesive 106 to the spacer 105 uses screen printing or dispensing. Thereafter, the holding device is operated to lower the lens block 100. At this time, the position of the lens block 100 is measured by a position sensor. Therefore, the tilt is corrected even when the lens block 100 is lowered.

Next, the lens substrate 101 of the lens block 100 and the lower end of the spacer 105 are held at an interval X. Here, the interval X is a sufficient interval that the outer peripheral portions of the lens portions 11 and 12 do not hit the end face of the spacer 105, but the UV adhesive 106 comes into contact with the lens substrate 101.

Similarly, a UV adhesive 106 is applied to the lower end of the spacer 105. Thereafter, the holding device is operated to lower the lens block 100 together with the spacer 105. At this time, the position of the lens block 100 is measured by a position sensor. Therefore, the tilt is corrected even when the lens block 100 is lowered.

Next, the lens substrate 101 of the lens block 200 and the lower end of the spacer 105 are held at an interval X ′. Here, the interval X ′ is a sufficient interval that the outer peripheral portions of the lens portions 11 and 12 do not hit the end face of the spacer 105, but the UV adhesive 106 comes into contact with the lens substrate 101. X + X ′ = predetermined value.

Further, in the state where the lens substrate 101 of the lens block 100 and the spacer 105 are held at a constant interval X, and the lens substrate 101 of the lens block 200 and the spacer 105 are held at a constant interval X ′, a UV (not shown). The light generator is operated, and the UV adhesive 106 is cured by irradiating UV light from the lens block 200 side. At this time, when the light blocking member is formed in the lens block 200, if the light blocking member is provided so as to exclude the periphery of the spacer 105, the UV light reaches the lower end and the upper end of the spacer 105, and the UV adhesive 106 is effectively cured. Can do. Thereby, the lens block 100 and the lens block 200 can be attached while the spacer 105 is interposed. In the above-described configuration, the two UV blocks are bonded simultaneously by the lens block 100 and the lens block 200. However, after either one is aligned and bonded, the other lens block may be bonded.

Thereafter, the imaging lens LN shown in FIG. 5 is formed by dicing at a position indicated by a dotted line DX in FIG.

(Example)
Next, examples suitable for the above-described embodiment will be described. However, the present invention is not limited to the following examples. The meaning of each code | symbol in an Example is as follows (a unit of length is mm other than a wavelength).
FL: Focal length of the entire imaging lens system (mm)
BF: Back focus (mm) (however, distance to paraxial image plane including cover glass)
Fno: F number w: Half angle of view (?) Ymax: Half length (mm) of diagonal length of imaging surface of solid-state imaging device
TL: Distance (mm) on the optical axis from the lens surface closest to the object side to the image-side focal point of the entire imaging lens system (however, “image-side focal point” means that parallel rays parallel to the optical axis are incident on the imaging lens. This is the image point when
r: radius of curvature of refractive surface (mm)
d: Distance between shaft upper surfaces (mm)
nd: Refractive index of lens material at d-line at room temperature vd: Abbe number of lens material STO: Aperture stop Note that D in the claims is the sum of d of surface numbers 1 to 4, and Σd in the claims Is the sum of d of all surface numbers, and DL1 in the claims is the sum of d of surface numbers 1 to 3.

In each embodiment, the surface described with “*” after each surface number is a surface having an aspheric shape, and the shape of the aspheric surface has the vertex of the surface as the origin and the X axis in the optical axis direction. The height in the direction perpendicular to the optical axis is represented by the following “Equation 1”.

However,
Ai: i-order aspherical coefficient R: reference radius of curvature K: conic constant.

In the following (including the lens data in the table), a power of 10 (for example, 2.5 × 10 ⁻⁰² ) is represented by using E (for example, 2.5e−002). The surface number of the lens data was given in order with the object side of the first lens as one surface. In addition, the unit of the numerical value showing the length as described in an Example shall be mm.

Example 1
Table 1 shows lens data in Example 1. 6 is a sectional view of the lens of Example 1. FIG. The imaging lens of Example 1 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first object side lens unit LB1a and the first lens substrate PP1, and a flare cut stop FS is provided between the first lens substrate PP1 and the first image side lens unit LB1b. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device.
In this embodiment, the lens substrate is glass.

(Table 1)
[Example 1]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 0.6236 0.1500 1.51784 56.10
STO INFINITY 0.3050 1.51690 61.89
3 INFINITY 0.1810 1.51784 56.10
4 * 1.2308 0.1260
5 * 1.5401 0.0580 1.51784 56.10
6 INFINITY 0.3000 1.51690 61.89
7 INFINITY 0.1920 1.51784 56.10
8 * 1.8445 0.1100
9 INFINITY 0.5000 1.47140 66.01
10 INFINITY 0.0193
IMG INFINITY
ASPHERICAL SURFACE
1: K = 1.79120e + 000, A3 = -1.17350e + 000, A4 = 1.81695e + 001, A5 = -1.30023e + 002, A6 = 3.91848e + 002, A7 = 0.00000e + 000, A8 = -4.20685 e + 003, A9 = 0.00000e + 000, A10 = 8.88289e + 004, A11 = 0.00000e + 000, A12 = -1.29992e + 006, A13 = 0.00000e + 000, A14 = 9.68907e + 006, A15 = 0.00000 e + 000, A16 = -2.80628e + 007, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -3.39260e + 001, A3 = 1.52360e + 000, A4 = -1.50040e + 001, A5 = 4.69460e + 001, A6 = 1.05630e + 001, A7 = 0.00000e + 000, A8 = -1.09630 e + 003, A9 = 0.00000e + 000, A10 = 9.43880e + 003, A11 = 0.00000e + 000, A12 = -3.81090e + 004, A13 = 0.00000e + 000, A14 = 5.87560e + 004, A15 = 0.00000 e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -7.58610e + 000, A3 = 9.73190e-001, A4 = -1.53070e + 001, A5 = 5.35330e + 001, A6 = -7.00910e + 001, A7 = 0.00000e + 000, A8 =- 1.44260e + 002, A9 = 0.00000e + 000, A10 = 1.12470e + 003, A11 = 0.00000e + 000, A12 = 6.39880e + 003, A13 = 0.00000e + 000, A14 = -8.66270e + 004, A15 = 0.00000e + 000, A16 = 2.11840e + 005, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -5.00000e + 001, A3 = 0.00000e + 000, A4 = -9.65860e-003, A5 = 0.00000e + 000, A6 = -3.50620e + 000, A7 = 0.00000e + 000, A8 = 1.75210 e + 001, A9 = 0.00000e + 000, A10 = -6.09420e + 001, A11 = 0.00000e + 000, A12 = 1.22910e + 002, A13 = 0.00000e + 000, A14 = -1.34010e + 002, A15 = 0.00000e + 000, A16 = 5.83690e + 001, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.5040
Fno 2.8680
w 30.2300
Ymax 0.8800
BF 0.6293
TL 1.9413
Elem Surfs Focal Length
1 1- 4 1.7982
2 5--8 11.1474

FIG. 7 is an aberration diagram of Example 1 (spherical aberration (a), astigmatism (b), distortion (c)). Here, in the spherical aberration diagram, the solid line represents the spherical aberration amount with respect to the d line and the dotted line, respectively, and in the astigmatism diagram, the solid line represents the sagittal surface and the dotted line represents the meridional surface (hereinafter the same).

(Example 2)
Table 2 shows lens data in Example 2. FIG. 8 is a sectional view of the lens of Example 2. The imaging lens of Example 2 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first object side lens unit LB1a and the first lens substrate PP1, and a flare cut stop FS is provided between the first image side lens unit LB1b and the first lens substrate PP1. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device.
In this embodiment, the lens substrate is glass.

(Table 2)
[Example 2]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 0.5977 0.1490 1.51784 56.10
STO INFINITY 0.3311 1.50990 62.39
3 INFINITY 0.1229 1.51784 56.10
4 * 1.3816 0.1260
5 * 2.7879 0.0550 1.51784 56.10
6 INFINITY 0.3000 1.50990 62.39
7 INFINITY 0.2200 1.51784 56.10
8 * 2.7360 0.0834
9 INFINITY 0.5000 1.47140 66.01
10 INFINITY 0.0274
IMG INFINITY

ASPHERICAL SURFACE
1: K = 1.67974e + 000, A3 = -1.21777e + 000, A4 = 1.74491e + 001, A5 = -1.10779e + 002, A6 = 2.36826e + 002, A7 = 0.00000e + 000, A8 = 1.14714e + 002, A9 = 0.00000e + 000, A10 = -1.05381e + 004, A11 = 0.00000e + 000, A12 = 4.29148e + 003, A13 = 0.00000e + 000, A14 = 9.92036e + 005, A15 = 0.00000e + 000, A16 = -5.44997e + 006, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -5.00000e + 001, A3 = 1.68242e + 000, A4 = -1.39494e + 001, A5 = 3.80393e + 001, A6 = 2.97788e + 001, A7 = 0.00000e + 000, A8 = -1.05083 e + 003, A9 = 0.00000e + 000, A10 = 6.93536e + 003, A11 = 0.00000e + 000, A12 = -1.16186e + 004, A13 = 0.00000e + 000, A14 = -3.00005e + 004, A15 = 0.00000e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -3.50921e + 001, A3 = 1.18652e + 000, A4 = -1.49320e + 001, A5 = 5.06077e + 001, A6 = -6.98651e + 001, A7 = 0.00000e + 000, A8 =- 1.70827e + 002, A9 = 0.00000e + 000, A10 = 1.74684e + 003, A11 = 0.00000e + 000, A12 = 5.07926e + 003, A13 = 0.00000e + 000, A14 = -1.23541e + 005, A15 = 0.00000e + 000, A16 = 3.34176e + 005, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -3.91217e + 001, A3 = 0.00000e + 000, A4 = -1.87915e-001, A5 = 0.00000e + 000, A6 = -2.96471e + 000, A7 = 0.00000e + 000, A8 = 1.60651 e + 001, A9 = 0.00000e + 000, A10 = -6.14734e + 001, A11 = 0.00000e + 000, A12 = 1.42979e + 002, A13 = 0.00000e + 000, A14 = -1.88537e + 002, A15 = 0.00000e + 000, A16 = 1.02474e + 002, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.4899
Fno 2.8400
w 30.2800
Ymax 0.8800
BF 0.6109
TL 1.9149 Elem Surfs Focal Length
1 1- 4 1.6106
2 5--8 101.6982

FIG. 9 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion (c)).

(Example 3)
Table 3 shows lens data in Example 3. FIG. 10 is a sectional view of the lens of Example 3. The imaging lens of Example 3 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided on the object side of the first object side lens unit LB1a, and a flare cut stop FS is provided between the first lens substrate PP1 and the first object side lens unit LB1a or the first image side lens unit LB1b. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device. In this embodiment, the lens substrate is glass.

(Table 3)
[Example 3]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
STO INFINITY -0.0181
2 * 0.6368 0.1463 1.51784 56.10
3 INFINITY 0.4052 1.51690 61.89
4 INFINITY 0.0529 1.56901 34.99
5 * 2.0461 0.1503
6 * 2.7069 0.0567 1.56901 34.99
7 INFINITY 0.3000 1.51690 61.89
8 INFINITY 0.2076 1.51784 56.10
9 * 1.7567 0.0621
10 INFINITY 0.5000 1.47140 66.01
11 INFINITY 0.0675
IMG INFINITY

ASPHERICAL SURFACE
2: K = -2.98000e + 001, A3 = 2.99096e-001, A4 = 1.49660e + 001, A5 = -6.44805e + 001, A6 = 7.86630e + 001, A7 = 0.00000e + 000, A8 = 6.52181e + 002, A9 = 0.00000e + 000, A10 = -1.01880e + 004, A11 = 0.00000e + 000, A12 = 2.64481e + 004, A13 = 0.00000e + 000, A14 = 6.03510e + 005, A15 = 0.00000e + 000, A16 = -4.00315e + 006, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -5.00000e + 001, A3 = 2.08229e + 000, A4 = -1.83693e + 001, A5 = 6.46118e + 001, A6 = -5.79974e + 001, A7 = 0.00000e + 000, A8 =- 4.77355e + 002, A9 = 0.00000e + 000, A10 = 4.69176e + 003, A11 = 0.00000e + 000, A12 = -1.83818e + 004, A13 = 0.00000e + 000, A14 = 2.75073e + 004, A15 = 0.00000e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
6: K = -5.00000e + 001, A3 = 1.13343e + 000, A4 = -1.16073e + 001, A5 = 3.50695e + 001, A6 = -4.67558e + 001, A7 = 0.00000e + 000, A8 =- 1.31428e + 001, A9 = 0.00000e + 000, A10 = 5.45524e + 001, A11 = 0.00000e + 000, A12 = 3.45906e + 003, A13 = 0.00000e + 000, A14 = -2.70589e + 004, A15 = 0.00000e + 000, A16 = 4.72880e + 004, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
9: K = -5.00000e + 001, A4 = 6.64790e-002, A6 = -3.20902e + 000, A8 = 1.57035e + 001, A10 = -5.76839e + 001, A12 = 1.27253e + 002, A14 =- 1.54176e + 002, A16 = 7.74969e + 001, A18 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.5213
Fno 2.9000
w 30.1800
Ymax 0.8800
BF 0.6296
TL 1.9485
Elem Surfs Focal Length
1 2- 5 1.6001
2 6 -9 -16.2328

FIG. 11 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion (c)).

(Example 4)
Table 4 shows lens data in Example 4. 12 is a sectional view of the lens of Example 4. FIG. The imaging lens of Example 4 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first object side lens unit LB1a and the first lens substrate PP1, and a flare cut stop FS is provided between the first lens substrate PP1 and the first image side lens unit LB1b. It has been. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device.
In this embodiment, the lens substrate is glass.

(Table 4)
[Example 4]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 0.7089 0.1400 1.51784 56.10
STO INFINITY 0.4050 1.51690 61.89
3 INFINITY 0.1150 1.56981 34.99
4 * 2.8608 0.1786
5 * 1.9193 0.0614 1.56956 34.99
6 INFINITY 0.3050 1.51690 61.89
7 INFINITY 0.1918 1.51784 56.10
8 * 1.6752 0.0621
9 INFINITY 0.5000 1.47140 66.01
10 INFINITY 0.0429
IMG INFINITY

ASPHERICAL SURFACE
1: K = -9.16377e + 000, A3 = -5.02664e-001, A4 = 1.19113e + 001, A5 = -5.44330e + 001, A6 = 8.43138e + 001, A7 = 0.00000e + 000, A8 = 6.45865 e + 002, A9 = 0.00000e + 000, A10 = -9.05064e + 003, A11 = 0.00000e + 000, A12 = 2.95359e + 003, A13 = 0.00000e + 000, A14 = 3.33251e + 005, A15 = 0.00000 e + 000, A16 = -3.79239e + 005, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -5.00000e + 001, A3 = 1.68690e + 000, A4 = -1.34840e + 001, A5 = 2.70173e + 001, A6 = 3.97745e + 001, A7 = 0.00000e + 000, A8 = -6.74075 e + 002, A9 = 0.00000e + 000, A10 = 2.69408e + 003, A11 = 0.00000e + 000, A12 = 3.07972e + 003, A13 = 0.00000e + 000, A14 = -3.56851e + 004, A15 = 0.00000 e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -5.00000e + 001, A3 = 9.69528e-001, A4 = -9.76840e + 000, A5 = 3.13051e + 001, A6 = -4.60150e + 001, A7 = 0.00000e + 000, A8 = 4.45534 e + 001, A9 = 0.00000e + 000, A10 = -4.28068e + 002, A11 = 0.00000e + 000, A12 = 4.09457e + 003, A13 = 0.00000e + 000, A14 = -1.33475e + 004, A15 = 0.00000e + 000, A16 = 4.01177e + 002, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -2.33504e + 001, A4 = -2.23704e-001, A6 = -8.12366e-001, A8 = 5.26365e + 000, A10 = -3.08347e + 001, A12 = 8.96998e + 001, A14 = -1.28054e + 002, A16 = 7.03246e + 001, A18 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.4840
Fno 2.8800
w 30.1100
Ymax 0.8800
BF 0.6050
TL 2.0017
Elem Surfs Focal Length
1 1- 4 1.6828
2 5--8 47.0511

FIG. 13 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion (c)).

(Example 5)
Table 5 shows lens data in Example 5. FIG. 14 is a sectional view of the lens of Example 5. The imaging lens of Example 5 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first object side lens unit LB1a and the first lens substrate PP1, and a flare cut stop FS is provided between the first lens substrate PP1 and the first image side lens unit LB1b. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device. In this embodiment, the lens substrate is glass.

(Table 5)
[Example 5]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 0.5603 0.1669 1.51784 56.10
STO INFINITY 0.3050 1.50990 62.39
3 INFINITY 0.1254 1.51784 56.10
4 * 0.9956 0.1120
5 * 2.4135 0.0556 1.51784 56.10
6 INFINITY 0.3050 1.50990 62.39
7 INFINITY 0.1900 1.51784 56.10
8 * 3.1380 0.0900
9 INFINITY 0.5000 1.47140 66.01
10 INFINITY 0.0378
IMG INFINITY

ASPHERICAL SURFACE
1: K = 1.86962e + 000, A3 = -1.24922e + 000, A4 = 1.78632e + 001, A5 = -1.12489e + 002, A6 = 2.21917e + 002, A7 = 0.00000e + 000, A8 = 2.85510e + 002, A9 = 0.00000e + 000, A10 = -1.11106e + 004, A11 = 0.00000e + 000, A12 = 3.14678e + 004, A13 = 0.00000e + 000, A14 = 1.87412e + 005, A15 = 0.00000e + 000, A16 = -1.15297e + 006, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -4.85971e + 001, A3 = 1.68877e + 000, A4 = -1.18799e + 001, A5 = 4.43316e + 001, A6 = -4.22401e + 000, A7 = 0.00000e + 000, A8 =- 1.08498e + 003, A9 = 0.00000e + 000, A10 = 1.18942e + 004, A11 = 0.00000e + 000, A12 = -4.22048e + 004, A13 = 0.00000e + 000, A14 = -6.13737e + 004, A15 = 0.00000e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -5.00000e + 001, A3 = 9.19980e-001, A4 = -1.28313e + 001, A5 = 4.51114e + 001, A6 = -7.10848e + 001, A7 = 0.00000e + 000, A8 = 8.19603 e + 001, A9 = 0.00000e + 000, A10 = -1.67745e + 002, A11 = 0.00000e + 000, A12 = 5.70082e + 003, A13 = 0.00000e + 000, A14 = -2.56887e + 004, A15 = 0.00000e + 000, A16 = 2.62756e + 004, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -5.00000e + 001, A3 = 0.00000e + 000, A4 = -3.89939e-001, A5 = 0.00000e + 000, A6 = -2.22374e + 000, A7 = 0.00000e + 000, A8 = 1.18935 e + 001, A9 = 0.00000e + 000, A10 = -4.73271e + 001, A11 = 0.00000e + 000, A12 = 1.27595e + 002, A13 = 0.00000e + 000, A14 = -2.18529e + 002, A15 = 0.00000e + 000, A16 = 1.66740e + 002, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.5040
Fno 2.8800
w 30.2400
Ymax 0.8800
BF 0.6278
TL 1.8878
Elem Surfs Focal Length
1 1- 4 1.6842
2 5--8 16.0204

FIG. 15 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion (c)).

(Example 6)
Table 5 shows lens data in Example 6. FIG. 16 is a sectional view of the lens of Example 6. The imaging lens of Example 6 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first object side lens unit LB1a and the first lens substrate PP1, and a flare cut stop FS is provided between the first lens substrate PP1 and the first image side lens unit LB1b. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device. In this embodiment, the lens substrate is glass.

(Table 6)
[Example 6]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 1.0190 0.1635 1.51784 56.10
STO INFINITY 0.5000 1.50990 62.39
3 INFINITY 0.1800 1.51784 56.10
4 * 2.0353 0.0983
5 * 0.6186 0.0811 1.51784 56.10
6 INFINITY 0.3000 1.50990 62.39
7 INFINITY 0.1376 1.51784 56.10
8 * 0.8966 0.2000
9 INFINITY 0.4000 1.47140 66.01
10 INFINITY 0.0843
IMG INFINITY

ASPHERICAL SURFACE
1: K = -7.65901e-001, A3 = -1.03984e + 000, A4 = 1.73643e + 001, A5 = -1.09530e + 002, A6 = 2.32709e + 002, A7 = 0.00000e + 000, A8 = 3.70648 e + 002, A9 = 0.00000e + 000, A10 = -1.18803e + 004, A11 = 0.00000e + 000, A12 = 1.94072e + 004, A13 = 0.00000e + 000, A14 = 6.10992e + 005, A15 = 0.00000 e + 000, A16 = -2.89470e + 006, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -2.52073e + 001, A3 = 5.17969e-001, A4 = -1.41371e + 001, A5 = 3.31525e + 001, A6 = 2.35750e + 001, A7 = 0.00000e + 000, A8 = -8.40099 e + 002, A9 = 0.00000e + 000, A10 = 5.55424e + 003, A11 = 0.00000e + 000, A12 = -1.58367e + 004, A13 = 0.00000e + 000, A14 = 1.34812e + 004, A15 = 0.00000 e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -5.19710e-002, A3 = 2.36816e-001, A4 = -1.39393e + 001, A5 = 4.52995e + 001, A6 = -7.25373e + 001, A7 = 0.00000e + 000, A8 =- 2.76946e + 001, A9 = 0.00000e + 000, A10 = 8.43713e + 002, A11 = 0.00000e + 000, A12 = 2.45940e + 003, A13 = 0.00000e + 000, A14 = -7.00580e + 004, A15 = 0.00000e + 000, A16 = 2.33427e + 005, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -3.80735e-001, A3 = 0.00000e + 000, A4 = -8.56003e-001, A5 = 0.00000e + 000, A6 = -2.04021e + 000, A7 = 0.00000e + 000, A8 = 1.15051 e + 001, A9 = 0.00000e + 000, A10 = -4.31359e + 001, A11 = 0.00000e + 000, A12 = 1.19219e + 002, A13 = 0.00000e + 000, A14 = -1.96772e + 002, A15 = 0.00000e + 000, A16 = 1.34596e + 002, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.4674
Fno 2.8800
w 30.5600
Ymax 0.8800
BF 0.6843
TL 2.1447
Elem Surfs Focal Length
1 1- 4 3.0689
2 5--8 2.3518

FIG. 17 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion (c)).

(Example 7)
Table 7 shows lens data in Example 7. FIG. 18 is a sectional view of the lens of Example 7. The imaging lens of Example 7 includes, in order from the object side, a first object side lens unit LB1a that is convex on the object side, a first lens substrate PP1 that is a parallel plate, and a first image side lens unit LB1b that is concave on the image side. The first lens block LB1 is composed of: a second object-side lens portion LB2a that is convex on the object side, a second lens substrate PP2 that is a parallel plate, and a second image-side lens portion LB2b that is concave on the image side. And a second lens block LB2. The object side surface of the second image side lens unit LB2b has a concave shape at the periphery, and the image side surface of the second image side lens unit LB2b has a convex shape at the periphery. An aperture stop S is provided between the first lens substrate PP1 and the first image side lens portion LB1b, and a flare cut stop FS is provided between the first object side lens portion LB1a and the first lens substrate PP1. Is provided. CG is a cover glass, and IM is an imaging surface of the solid-state imaging device. In this embodiment, the lens substrate is a resin.

(Table 7)
[Example 7]
Reference Wave Length = 587.56 nm

Construction Data
NUM. R d nd vd
OBJ INFINITY 600.0000
1 * 0.5753 0.1607 1.51784 56.10
2 INFINITY 0.2050 1.52000 52.99
STO INFINITY 0.0868 1.51784 56.10
4 * 1.4103 0.2157
5 * 4.8084 0.1411 1.51784 56.10
6 INFINITY 0.3043 1.52000 52.99
7 INFINITY 0.1900 1.51784 56.10
8 * 6.9686 0.0505
9 INFINITY 0.6000 1.47140 66.01
10 INFINITY -0.0020
IMG INFINITY

ASPHERICAL SURFACE
1: K = 1.78463e + 000, A3 = -9.09226e-001, A4 = 1.67533e + 001, A5 = -1.17480e + 002, A6 = 2.45829e + 002, A7 = 0.00000e + 000, A8 = 4.89080e + 002, A9 = 0.00000e + 000, A10 = -1.34594e + 004, A11 = 0.00000e + 000, A12 = -1.03695e + 004, A13 = 0.00000e + 000, A14 = 9.45808e + 005, A15 = 0.00000 e + 000, A16 = -3.85897e + 006, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
4: K = -2.16762e + 001, A3 = 1.61669e + 000, A4 = -1.35841e + 001, A5 = 4.15560e + 001, A6 = 3.05182e + 001, A7 = 0.00000e + 000, A8 = -1.15455 e + 003, A9 = 0.00000e + 000, A10 = 6.60766e + 003, A11 = 0.00000e + 000, A12 = 6.32076e + 002, A13 = 0.00000e + 000, A14 = -2.79242e + 004, A15 = 0.00000 e + 000, A16 = 0.00000e + 000, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
5: K = -2.89216e + 000, A3 = 1.09562e + 000, A4 = -1.35506e + 001, A5 = 4.75755e + 001, A6 = -6.05885e + 001, A7 = 0.00000e + 000, A8 =- 1.58935e + 002, A9 = 0.00000e + 000, A10 = 6.04866e + 002, A11 = 0.00000e + 000, A12 = 1.50329e + 004, A13 = 0.00000e + 000, A14 = -1.37638e + 005, A15 = 0.00000e + 000, A16 = 3.42243e + 005, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000
8: K = -9.26255e-001, A3 = 0.00000e + 000, A4 = -3.50608e-002, A5 = 0.00000e + 000, A6 = -3.31831e + 000, A7 = 0.00000e + 000, A8 = 1.60609 e + 001, A9 = 0.00000e + 000, A10 = -5.83315e + 001, A11 = 0.00000e + 000, A12 = 1.25609e + 002, A13 = 0.00000e + 000, A14 = -1.44922e + 002, A15 = 0.00000e + 000, A16 = 6.81959e + 001, A17 = 0.00000e + 000, A18 = 0.00000e + 000, A19 = 0.00000e + 000, A20 = 0.00000e + 000

FL 1.4860
Fno 2.8400
w 30.9900
Ymax 0.8800
BF 0.6413
TL 1.9450
Elem Surfs Focal Length
1 1- 4 1.5730
2 5--8 27.0462

FIG. 19 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion (c)).

Table 8 summarizes the values of the examples corresponding to each conditional expression.

The present invention is not limited to the embodiments described in the specification, and includes other embodiments and modifications for those skilled in the art from the embodiments and technical ideas described in the present specification. it is obvious. The description and examples are for illustrative purposes only, and the scope of the invention is indicated by the following claims.

B Operation buttons D1, D2 Display screen L1 First lens L2 Second lens L3 Third lens LN Imaging lens LU Imaging device CG Plate S Aperture stop IM Image sensor IMA Photoelectric conversion unit T Mobile phone

Claims (15)

1. When an optical element including a lens substrate that is a parallel plate and a lens unit that is formed on at least one of the object side surface and the image side surface and has a positive or negative power is called a lens block, in order from the object side to the object side. A first lens block having a positive power with a convex surface facing the concave surface toward the image side, and a second lens block having a convex surface facing the object side and a concave surface facing the image side, the aperture stop being the first lens An imaging lens which is provided on the object side of the block or inside the first lens block, and the object side lens portion of the second lens block has a concave shape in the periphery and satisfies the following conditional expression.
   −3.5 <r12 / f (1-N13) <− 1.1 (1)
   0.5 <D / Σd <0.65 (2)
   However,
   r12: Paraxial radius of curvature (mm) of the side surface of the first lens block image
   f: Focal length (mm) of the entire imaging lens system
   N13: Refractive index D of the first lens block image side lens part D: Distance on the optical axis from the first lens block object side surface to the second lens block object side surface (mm)
   Σd: distance on the optical axis from the first lens block object side surface to the second lens block image side surface (mm)
2. 2. The imaging lens according to claim 1, wherein an image side surface of the second lens block has a convex shape at a peripheral portion.
3. The imaging lens according to claim 1, wherein the first lens block satisfies the following conditional expression.
   0.3 <DL1 / f <0.6 (3)
   However,
   DL1: Distance on the optical axis from the object side surface to the image side surface of the first lens block (mm)
4. The imaging lens according to any one of claims 1 to 3, wherein the second lens block satisfies the following conditional expression.
   0.7 <r21 / r22 <1.8 (4)
   However,
   r21: Paraxial radius of curvature (mm) of the object side surface of the second lens block
   r22: Paraxial radius of curvature (mm) of the side surface of the second lens block image
5. The imaging lens according to any one of claims 1 to 4, wherein the first lens block satisfies the following conditional expression.
   0.23 <r11 / r12 <0.6 (5)
   However,
   r11: paraxial radius of curvature (mm) of the object side surface of the first lens block
6. The imaging lens according to any one of claims 1 to 5, wherein the aperture stop is provided between the object side lens unit or image side lens unit and the lens substrate in the first lens block.
7. In the first lens block, a flare cut stop is provided at a position different from the aperture stop between the object side lens unit or the image side lens unit and the lens substrate, and the flare cut stop has the following conditional expression: The imaging lens according to claim 6, wherein:
   φ0 <L (6)
   However,
   L: Shortest distance (mm) from the optical axis to the flare cut aperture
   φ0: Radius radius (mm) of the axial light beam at the flare-cut stop position
8. The imaging lens according to any one of claims 1 to 5, wherein the aperture stop is provided closer to the object side than the first lens block.
9. The first lens block has a flare cut stop between an object side lens unit or an image side lens unit and the lens substrate, and the flare cut stop satisfies the following conditional expression. 8. The imaging lens according to 8.
   φ0 <L (6)
   However,
   L: Shortest distance (mm) from the optical axis to the flare cut aperture
   φ0: Radius radius (mm) of the axial light beam at the flare-cut stop position
10. The imaging lens according to claim 1, wherein the object side and image side lens portions of the second lens block satisfy the following conditional expression.
    20 <ν21 <45 (7)
    45 <ν23 <65 (8)
    However,
    ν21: Abbe number with respect to d-line of the second lens block object side lens portion ν23: Abbe number with respect to d line of the second lens block image side lens portion
11. The imaging lens according to claim 1, wherein the lens substrate is made of a resin material.
12. The imaging lens according to any one of claims 1 to 10, wherein the lens substrate is made of a glass material.
13. The imaging lens according to any one of claims 1 to 12, wherein the imaging lens satisfies the following conditional expression.
    0.3 <DCG / Ymax <0.7 (9)
    However,
    DCG: Maximum thickness of sensor cover glass Ymax: Half the diagonal length of the imaging surface of the solid-state imaging device
14. The imaging lens according to any one of claims 1 to 13, wherein the imaging lens satisfies the following conditional expression.
    1.9 <TL / Ymax <2.5 (10)
    However,
    TL: Distance (mm) on the optical axis from the lens surface closest to the object side to the image-side focal point of the entire imaging lens system (however, “image-side focal point” means that parallel rays parallel to the optical axis are incident on the imaging lens. This is the image point when
15. An imaging apparatus comprising the imaging lens according to any one of claims 1 to 14.

Images