WO2012114970A1 - Imaging lens, imaging device, and portable terminal - Google Patents

Abstract

Provided is an imaging lens that, by means of using a solid-state imaging element having a curved imaging surface, has an F value of less than F3.0, is able to suppress shading, has a high performance, and is compact. Further provided are a portable terminal and an imaging device using the imaging lens. The imaging lens is of an imaging device having: a solid-state imaging element provided with a photoelectric conversion section; and an imaging lens that forms an image of an imaging subject at the photoelectric conversion section of the solid-state imaging element. The imaging surface of the solid-state imaging element is curved. The imaging lens, in order from the object side, comprises a first lens having a positive refractive power, a second lens having a positive refractive power, and a third lens having a negative refractive power. The following conditional expressions are satisfied: -1.1 < f12/f3 < 0 …(1), 0.11 < D5/f < 0.7 …(2), and -10.0 < RI/Y < -2.0 …(3), where f12 is the combined focal distance (mm) of the first lens and the second lens, f3 is the focal distance (mm) of the third lens, D5 is the on-axis thickness (mm) of the third lens, f is the focal distance (mm) of the entire imaging lens system, RI is the radius (mm) of curvature of the imaging surface of the solid-state imaging element, and Y is the maximum image height (mm).

Description

Imaging lens, imaging device, and portable terminal

The present invention relates to an imaging lens, an imaging apparatus, and a portable terminal, and in particular, the present invention is a solid-state imaging device such as a CCD-type image sensor or a CMOS-type image sensor and suitable for a solid-state imaging device having a curved imaging surface. The present invention relates to a lens, an imaging device, and a portable terminal using the same.

In recent years, small and thin imaging devices have come to be installed in portable terminals that are small and thin electronic devices such as mobile phones and PDAs (Personal Digital Assistants). Information can also be transmitted between each other.

As an image pickup element used in these image pickup apparatuses, a solid-state image pickup element such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor is used. In recent years, the pixel pitch of the image sensor has been reduced, and higher resolution and higher performance have been achieved by increasing the number of pixels. On the other hand, downsizing of the image sensor has been achieved while maintaining high pixels. Furthermore, an attempt has been made to curve the imaging surface of the imaging element. There is a need for a compact and high-performance imaging lens suitable for such an imaging device.

Here, a three-lens configuration is suitable as a small and high-performance imaging lens. Patent Documents 1 to 3 disclose an imaging lens having a three-lens configuration with a curved imaging surface. An imaging lens having a single lens configuration in which the imaging surface of a solid-state imaging device is curved is disclosed in Patent Document 4.

JP 2006-47944 A Japanese Patent Application Laid-Open No. 08-68935 JP 2000-292688 A JP 2004-356175 A

Patent Document 1 describes a photographing lens that is suitable for a compact camera or a lens-equipped film unit, has a wide photographing angle of view of about 80 degrees, and has a brightness of F3.5 to F4. The lens configuration includes a positive first lens, an aperture stop, a positive second lens, and a negative third lens, or a negative first lens, an aperture stop, a positive second lens, and a negative third lens.

Here, an imaging lens used for a solid-state imaging device having a small pixel size needs to have a different characteristic from a lens for a film camera that requires high resolution in order to cope with a highly thinned pixel. . However, the resolving power of the lens is limited by the F value, and a bright lens having a small F value can obtain a high resolving power. Therefore, as in Patent Document 1, sufficient performance can be obtained with an F value of about F3.5. I can't.

Next, Patent Document 2 and Patent Document 3 describe a photographing lens that is suitable for a compact camera or a lens-equipped film unit, and has a photographing field angle of about 77 degrees and a brightness of F 5.7 to F6.2. Has been. The lens configuration is a rear stop triplet type lens including a positive first lens, a negative second lens, a positive third lens, and an aperture stop.

Since the lenses of Patent Document 2 and Patent Document 3 have an F value that is darker than F5, higher resolution than the lens of Patent Document 1 cannot be obtained. Furthermore, the triplet type has a problem that the back focus tends to be long, so that the photographic lens and the imaging device are increased in size.

Further, Patent Documents 1 to 3 disclose photographic lenses for film cameras, which improve performance by curving the film surface (imaging surface) in accordance with the curvature of field generated by the lens. It is intended. However, since both are camera-use photographic lenses that use a roll film, the film surface is a so-called cylindrical imaging surface that curves only in the direction of the long side of the screen due to the structure of the camera. Therefore, although good performance can be obtained in the long side direction of the screen, the imaging surface in the short side direction of the screen remains flat, so performance cannot be improved and deterioration may occur depending on the correction status of field curvature. obtain. That is, it can be said that it is difficult to obtain high performance over the entire screen by bending only the long side direction of the imaging surface as in Patent Documents 1 to 3.

Further, as disclosed in Patent Documents 1 to 3, since it is a photographing lens for a film camera as described above, the chief ray incident angle of the light beam incident on the imaging surface is not necessarily small at the periphery of the imaging surface. It is not designed. In an imaging lens for forming a subject image on the photoelectric conversion unit of a solid-state image sensor, when the chief ray incident angle of the light beam incident on the imaging surface, so-called telecentric characteristics, deteriorates, the light beam enters the solid-state image sensor obliquely. A phenomenon (shading) in which the substantial aperture efficiency decreases in the periphery of the imaging surface may occur, resulting in insufficient peripheral light amount.

On the other hand, Patent Document 4 discloses a photographing device such as a cellular phone, which corrects the curvature of field and distortion generated by a lens in a well-balanced manner by curving a solid-state imaging device into a polynomial surface shape, and is small in size and resolution. An imaging device having a high value is disclosed. However, since the solid-state image sensor has a CIF size (352 pixels × 288 pixels), the image pickup lens has a single lens configuration, and thus the chromatic aberration is not sufficiently corrected. If there is, it is not possible to obtain a high-quality image suitable for it.

The present invention has been made in view of such a problem. By utilizing the fact that the projection surface such as the imaging surface is curved, the present invention is small, has high performance, can suppress shading, An object is to obtain an imaging lens having a value smaller than F3.0, an imaging device using the imaging lens, and a portable terminal.

The imaging lens according to claim 1 is an imaging lens for forming a subject image on a projection surface provided in an imaging device,
The projection surface is curved with an arbitrary cross section toward the periphery of the screen,
The imaging lens includes a first lens having a positive refractive power in order from the object side, a second lens having a positive refractive power, and a third lens having a negative refractive power,
The following conditional expression is satisfied.
-1.1 <f12 / f3 <0 (1)
0.11 <D5 / f <0.7 (2)
-10.0 <RI / Y <-2.0 (3)
However,
f12: Composite focal length (mm) of the first lens and the second lens
f3: focal length (mm) of the third lens
D5: Axial thickness (mm) of the third lens
f: Focal length (mm) of the entire imaging lens system
RI: radius of curvature (mm) of the imaging surface of the solid-state imaging device
Y: Maximum image height (mm)

The imaging lens of the present invention is based on the premise that the projection surface is not a curved surface only in the long side direction as in a conventional film camera, but a curved surface curved in an arbitrary cross section toward the periphery of the screen. Since the projection surface is curved in this way, it is possible to achieve both downsizing and high performance of the imaging apparatus. More specifically, when the projection surface is curved toward the imaging lens side, it becomes advantageous to correct the chief ray incident angle of the light beam incident on the projection surface, so-called telecentric characteristics. When the projection surface is curved, the chief ray incident angle of the light beam incident on the projection surface is smaller when the projection surface is curved, so that the imaging lens can sufficiently correct the telecentric characteristics. Even if it is not performed, the aperture efficiency does not decrease and the occurrence of shading can be suppressed. Further, distortion and coma can be easily corrected, and the image pickup apparatus can be downsized. Further, the projection surface is preferably curved into a spherical shape. When curved in a spherical shape, both the long side direction and the short side direction of the screen are curved in the same manner and can be adjusted to the curvature of field of the imaging lens, so that the performance can be improved over the entire screen. Furthermore, since it is not necessary to sufficiently correct the curvature of field with the imaging lens, it is not necessary to reduce the Petzval sum, and the refractive power of each surface can be set relatively weak, so that the occurrence of chromatic aberration and coma is also suppressed. be able to.

The imaging lens includes, in order from the object side, a first lens having a positive refractive power, a second lens having a positive refractive power, and a third lens having a negative refractive power. This lens configuration of a so-called telephoto type in which a positive group consisting of a first lens and a second lens and a negative group consisting of a third lens are arranged is advantageous in reducing the overall length of the imaging lens. In addition, since positive refractive power is shared by the first lens and the second lens, it is possible to suppress the occurrence of spherical aberration and coma. Furthermore, it is possible to realize a lens that has few factors of decentration error and high productivity.

Conditional expression (1) is a conditional expression for appropriately setting the focal length of the positive lens group of the first lens and the second lens and the negative focal length of the third lens, and achieving a good balance between downsizing and aberration correction. It is. When the value of conditional expression (1) is less than the upper limit, it is possible to satisfactorily reduce the overall lens length and correct field curvature and off-axis aberrations. On the other hand, when the value of conditional expression (1) exceeds the lower limit, the focal length of the third lens does not become too small, and distortion and coma can be corrected well. More preferably, the range of the following formula is good.
−1.0 <f12 / f3 <−0.1 (1 ′)
Furthermore, the range of the following formula is desirable.
-0.95 <f12 / f3 <-0.1 (1 ")

Conditional expression (2) is a conditional expression for appropriately setting the thickness of the third lens. When the value of conditional expression (2) exceeds the lower limit, it is possible to prevent the third lens from becoming too thin and increase the difficulty of workability. On the other hand, if the value of conditional expression (2) is below the upper limit, the third lens will not be too thick, the occurrence of lateral chromatic aberration can be suppressed, the overall length of the lens can be easily reduced, and the imaging lens and imaging apparatus can be made smaller. Can be planned. More preferably, the range of the following formula is good.
0.12 <D5 / f <0.6 (2 ′)
Furthermore, the range of the following formula is desirable.
0.13 <D5 / f <0.5 (2 ")

Conditional expression (3) is a conditional expression for appropriately setting the curvature of the projection surface. If the value of conditional expression (3) is less than the upper limit, the curvature of the projection surface becomes large, and it is possible to prevent an increase in the telecentric characteristics and the correction burden of the field curvature in the imaging lens, so the Petzval sum does not become too small. The coma and chromatic aberration can be corrected well. On the other hand, when the value of conditional expression (3) exceeds the lower limit, the curvature of the projection surface becomes small, and it is possible to prevent overcorrection of the curvature of field. Further, it is possible to prevent the final surface of the imaging lens from being too close to the projection surface, and to sufficiently secure an air space for inserting an IR cut filter or the like. More preferably, the range of the following formula is good.
-9.0 <RI / Y <-2.0 (3 ')

According to a second aspect of the present invention, there is provided the imaging lens according to the first aspect, wherein the first lens has a shape with a convex surface facing the object side, and satisfies the following conditional expression.
0.7 <f1 / f <1.7 (4)
However,
f1: Focal length (mm) of the first lens

When the first lens has a convex surface facing the object side, it is advantageous for downsizing the imaging lens. Since the first surface of the imaging lens has a positive refractive power, the principal point position can be arranged close to the object side, and the telephoto type can be maintained, so that the size can be easily reduced.

Conditional expression (4) is a conditional expression for appropriately setting the focal length of the first lens. When the value of conditional expression (4) is less than the upper limit, the focal length of the first lens does not become too large, and it is possible to avoid that the principal point position of the entire imaging lens system is too close to the image side. The total lens length of the system can be kept small. On the other hand, when the value of conditional expression (4) exceeds the lower limit, the focal length of the first lens does not become too small, and coma and distortion can be corrected well. More preferably, the range of the following formula is good.
0.8 <f1 / f <1.6 (4 ′)

According to a third aspect of the present invention, in the image pickup lens according to the first or second aspect, the second lens has a shape with a convex surface facing the image side, and satisfies the following conditional expression: .
−5 <R4 / ((n2-1) * f) <− 0.4 (5)
Where R4: radius of curvature of the image side surface of the second lens (mm)
n2: refractive index of the second lens with respect to d-line

When the second lens is shaped so that its convex surface faces the image side, the image side surface of the second lens has a positive refractive power, so that the peripheral luminous flux incident on the third lens is converged on the optical axis. Pass close. As a result, off-axis aberrations that occur around the lens can be kept small.

Conditional expression (5) is a conditional expression for appropriately setting the positive refractive power of the image side surface of the second lens. When the value of conditional expression (5) is less than the upper limit, the positive refractive power on the side surface of the second lens image does not increase more than necessary, and the occurrence of coma flare of off-axis light flux and distortion is suppressed. And good performance can be obtained. On the other hand, when the value of conditional expression (5) exceeds the lower limit, the positive refractive power of the side surface of the second lens image can be appropriately maintained. Therefore, the Petzval sum is prevented from becoming too large, and the effect of the curved image surface is obtained. In addition, the field curvature can be corrected well. More preferably, the range of the following formula is good.
-4 <R4 / ((n2-1) * f) <-0.5 (5 ')

The imaging lens according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, an aperture stop is disposed between the first lens and the second lens.

When the aperture stop is disposed between the first lens and the second lens, the positive first lens and the positive second lens have a symmetrical configuration with the aperture stop interposed therebetween, so that the chromatic aberration of magnification And distortion can be easily corrected.

An imaging lens according to a fifth aspect of the present invention is the imaging lens according to any one of the first to third aspects, wherein the aperture stop is located closer to the object side than the object side surface position of the periphery of the first lens within the effective diameter of the first lens. It is characterized by arranging.

When a so-called front stop, in which the aperture stop is arranged on the object side of the first lens, the exit pupil position is separated from the image plane, which is advantageous for correcting the telecentric characteristics. Even in an imaging lens where the telecentric characteristic does not need to be sufficiently corrected by curving the projection surface as in the present invention, if the front diaphragm configuration is used, the correction of the telecentric characteristic is almost unnecessary. Therefore, high performance can be realized. Furthermore, even when a mechanical shutter is required, it can be advantageously arranged at the most object side.

The imaging lens described in claim 6 is characterized in that in the invention described in any one of claims 1 to 5, the imaging lens further includes a lens having substantially no power. That is, even when a dummy lens having substantially no power is added to the configuration of claim 1, it is within the scope of application of the present invention.

An imaging device according to claim 7 is a solid-state imaging device including a photoelectric conversion unit, a substrate on which the solid-state imaging device is held and a connection terminal unit for transmitting and receiving electrical signals is formed, and Item 6. The image pickup lens according to any one of Items 1 to 6, and a housing made of a light-shielding material that includes the image pickup lens and has an opening for light incidence from the object side. .

By using the imaging lens of the present invention, a smaller and higher performance imaging device can be obtained.

A portable terminal according to an eighth aspect includes the imaging device according to the seventh aspect.

By using the imaging device of the present invention, a smaller and higher performance portable terminal can be obtained.

According to the present invention, since the projection surface is curved, the imaging lens is small, has high performance, can suppress shading, and has an F value smaller than F3.0, and an imaging apparatus using the imaging lens, and A portable terminal can be obtained.

It is a perspective view of the imaging device concerning this embodiment. It is the figure which showed the cross section along the optical axis of the imaging lens of the imaging device which concerns on this Embodiment in duplicate. It is an external view of the mobile telephone which is an example of the portable terminal provided with the imaging device which concerns on this Embodiment. 2 is a cross-sectional view of an imaging lens of Example 1. FIG. FIG. 4 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 1. 6 is a cross-sectional view of an imaging lens of Example 2. FIG. FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 2. 6 is a cross-sectional view of an imaging lens of Example 3. FIG. FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 3. 6 is a cross-sectional view of an imaging lens of Example 4. FIG. FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 4. 6 is a cross-sectional view of an imaging lens of Example 5. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 5. 6 is a cross-sectional view of an imaging lens of Example 6. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 6. 10 is a cross-sectional view of an imaging lens of Example 7. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 7. 10 is a cross-sectional view of an imaging lens of Example 8. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 8. 10 is a cross-sectional view of an imaging lens of Example 9. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 9. 10 is a cross-sectional view of an imaging lens of Example 10. FIG. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) of the imaging lens of Example 10.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a top view of an imaging apparatus 50 according to the present embodiment, and FIG. 2 is a cross-sectional view obtained by cutting the configuration of FIG. 1 along a cross section including an optical axis.

As illustrated in FIG. 1 or FIG. 2, the imaging device 50 includes a CMOS type imaging device 51 as a solid-state imaging device having a photoelectric conversion unit 51 a and an imaging lens that captures a subject image on the photoelectric conversion unit 51 a on the imaging device 51. 10 and a casing 53 made of a light shielding member having an opening for light incidence from the object side, and these are integrally formed.

As shown in FIG. 2, the image sensor 51 is spherically curved with a predetermined radius of curvature, and a pixel (photoelectric conversion element) is two-dimensionally arranged at the center of the curved light receiving side surface (projection surface). A photoelectric conversion unit 51a as a light receiving unit is formed, and a signal processing circuit 51b is formed around the photoelectric conversion unit 51a. The signal processing circuit 51b includes a driving 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. Note that the image pickup element is not limited to the above-described CMOS type image sensor, and may be one to which another one such as a CCD is applied.

The seal glass C is fixed to the photoelectric conversion unit 51 a side of the image sensor 51 through the spacer B, and the seal glass C or the side surface of the image sensor 51 is fixed to the housing 53. The seal glass C is a flat plate here, but may be curved in accordance with the photoelectric conversion unit 51a.

A plurality of external electrodes 52 used for connection to an external circuit are formed on the other surface of the image sensor 51 (surface opposite to the photoelectric conversion unit 51a). The external electrode 52 and an external circuit (not shown) (for example, a control circuit included in a host device on which the imaging device is mounted) are connected to receive a voltage or a clock signal for driving the imaging device 51 from the external circuit. In addition, it is possible to output a digital YUV signal to an external circuit.

Although not shown, a substrate is disposed on the surface opposite to the photoelectric conversion unit 51a of the image sensor 51, the substrate and the image sensor 51 are connected by wire bonding, and an external surface is connected to the surface of the substrate opposite to the image sensor. A plurality of external electrodes used for connection with a circuit may be formed.

As shown in FIG. 2, the housing 53 made of a light-shielding member is screwed into a lens frame 55 that holds the imaging lens 10 on the photoelectric conversion unit 51 a side of the imaging element 51, whereby the imaging lens 10 is Adjustable in the optical axis direction.

The imaging lens 10 includes, in order from the object side, a positive first lens L1, an aperture stop S, a positive second lens L2, and a negative third lens L3. A subject image is captured on the photoelectric conversion surface 51a of the imaging element 51. It is configured to form an image. 2 are the optical axes of the lenses L1 to L3.

Any one of the first lens L1, the second lens L2, the third lens L3, and the seal glass C is coated with an infrared light cut coat. Although not shown, an infrared light cut filter may be disposed in front of the seal glass instead of the infrared cut coat.

The lenses L1 to L3 constituting the imaging lens 10 are held by a lens frame 55 made of a light shielding member. Each of the lenses L1 to L3 has an outer diameter that increases from the object side toward the image side, and a disc-shaped light shielding member SH1 having an aperture stop S formed in the center between the flange portions of the lenses L1 and L2. Is arranged. Further, the light shielding member SH2 is fixed to the lens frame 55 so as to contact the image side flange portion of the lens L2. The surfaces of the light shielding members SH1 and SH2 that cut unnecessary light may be stepped or roughened. Further, a light shielding member may be disposed between the third lens L3 and the seal glass C. By arranging the light shielding member outside the light beam path, it is possible to suppress the occurrence of ghost and flare. In the case of the imaging apparatus shown in FIG. 2, H in the figure is the height of the imaging lens in the optical axis direction of the imaging apparatus.

FIG. 3 is an external view of a mobile phone 100 which is an example of a mobile terminal provided with the imaging device 50 according to the present embodiment. In the mobile phone 100 shown in the figure, an upper casing 71 as a case having display screens D1 and D2 and a lower casing 72 having an operation button 60 as an input unit are connected via a hinge 73. Yes. The imaging device 50 is built below the display screen D <b> 2 in the upper casing 71, and is arranged so that the imaging device 50 can capture light from the outer surface side of the upper casing 71. Note that the position of the imaging device may be disposed above or on the side of the display screen D2 in the upper casing 71. Of course, the mobile phone is not limited to a folding type.

(Example)
Next, examples suitable for the above-described embodiment will be described. However, the present invention is not limited to the following examples. Symbols used in each example are as follows.
f: focal length of the entire imaging lens system fB: back focus F: F number Y: imaging surface (projected surface) diagonal maximum image height R of solid-state imaging device R: radius of curvature D: axial upper surface distance Nd: d of lens material Refractive index νd for line: Abbe number of lens material
ENTP: Entrance pupil position (distance from first surface to entrance pupil position)
EXTP: Exit pupil position (distance from imaging surface to exit pupil position)
H1: Front principal point position (distance from the first surface to the front principal point position)
H2: Rear principal point position (distance from the final surface to the rear principal point position)

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”.

ただし、
Ａｉ：ｉ次の非球面係数
Ｒ　：曲率半径
Ｋ　：円錐定数

However,
Ai: i-order aspheric coefficient R: radius of curvature K: conic constant

Example 1
Lens data is shown in Table 1. In the following (including the lens data in the table), a power of 10 (for example, 2.5 × 10 ⁻⁰² ) is expressed using E (for example, 2.5E-02). 4 is a sectional view of the lens of Example 1. FIG. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 5A is a spherical aberration diagram of Example 1, FIG. 5B is an astigmatism diagram, and FIG. 5C is a distortion diagram. Here, in the spherical aberration diagram and the coma aberration diagram, g represents the amount of spherical aberration with respect to the g line, and d represents the amount of spherical aberration with respect to the d line. In the astigmatism diagram, the solid line S represents the sagittal plane, and the dotted line M represents the meridional plane (the same applies hereinafter). The aperture stop S is between the first lens L1 and the second lens L2.

[Table 1]
Example 1
f = 4.53mm fB = 0.96mm F = 2.5 Y = 2.85mm
ENTP = 0.67mm EXTP = -2.47mm H1 = -0.79mm H2 = -3.58mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.727 0.72 1.54400 55.9 1.10
2 * 4.197 0.08 0.82
3 (Aperture) ∞ 0.35 0.80
4 * 10.551 0.66 1.54400 55.9 0.94
5 * -5.158 0.65 1.07
6 * -2.772 1.50 1.63200 23.4 1.09
7 * -14.872 0.15 2.10
8 ∞ 0.15 1.51630 64.1 2.51
9 ∞ 0.96 2.56
Imaging surface -15.000 2.85

Aspheric coefficient 1st surface 5th surface
K = -0.12298E + 01 K = -0.15350E + 00
A4 = 0.23416E-01 A4 = -0.53310E-01
A6 = 0.41569E-03 A6 = -0.17789E-01
A8 = -0.60793E-03 A8 = -0.76264E-02
A10 = -0.13455E-02 A10 = -0.52446E-02
2nd side 6th side
K = 0.16932E + 02 K = 0.49127E + 01
A4 = -0.33538E-01 A4 = -0.96753E-01
A6 = -0.84783E-02 A6 = 0.33487E-01
A8 = -0.34741E-01 A8 = -0.10316E + 00
A10 = -0.34757E-02 A10 = 0.74701E-01
A12 = -0.41087E-01
4th surface 7th surface
K = 0.30000E + 02 K = -0.30000E + 02
A4 = -0.30255E-01 A4 = -0.26805E-01
A6 = -0.28440E-01 A6 = 0.53224E-03
A8 = 0.16145E-01 A8 = -0.16008E-03
A10 = -0.23326E-01 A10 = -0.45517E-04
A12 = 0.91186E-05

Single lens data
Lens Start surface Focal length (mm)
1 1 4.891
2 4 6.464
3 6 -5.663

(Example 2)
Table 2 shows the lens data. 6 is a sectional view of the lens of Example 2. FIG. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 7A is a spherical aberration diagram of Example 2, FIG. 7B is an astigmatism diagram, and FIG. 7C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 2]
Example 2
f = 3.63mm fB = 0.94mm F = 2.6 Y = 2.85mm
ENTP = 0.55mm EXTP = -2.02mm H1 = -0.28mm H2 = -2.7mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.907 0.62 1.54400 55.9 0.99
2 * 4.601 0.08 0.71
3 (Aperture) ∞ 0.06 0.64
4 * 4.284 0.96 1.54400 55.9 0.64
5 * -3.271 0.45 0.92
6 * -2.234 1.50 1.63200 23.4 0.96
7 * -12.247 0.94 2.10
Imaging surface -8.000 2.85

Aspheric coefficient
1st side 5th side
K = -0.22087E + 01 K = 0.93377E + 01
A4 = 0.37899E-02 A4 = -0.27020E-01
A6 = -0.18913E-01 A6 = 0.43137E-01
A8 = -0.21174E-01 A8 = -0.92446E-01
A10 = 0.47534E-02 A10 = 0.52133E-01
2nd side 6th side
K = 0.67817E + 01 K = 0.41049E + 01
A4 = -0.73037E-01 A4 = -0.11481E + 00
A6 = -0.53993E-01 A6 = 0.10527E + 00
A8 = 0.13046E-01 A8 = -0.34848E + 00
A10 = 0.17663E-01 A10 = 0.40501E + 00
A12 = -0.25153E + 00
4th surface 7th surface
K = -0.50699E + 01 K = 0.13833E + 02
A4 = -0.23486E-01 A4 = -0.21544E-01
A6 = -0.31836E-01 A6 = 0.41624E-02
A8 = 0.28013E-01 A8 = -0.17492E-02
A10 = -0.18584E-01 A10 = 0.28673E-03
A12 = -0.15571E-04

Single lens Data lens Start surface Focal length (mm)
1 1 5.540
2 4 3.570
3 6 -4.589

(Example 3)
Table 3 shows lens data. FIG. 8 is a sectional view of the lens of Example 3. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 9A is a spherical aberration diagram of Example 3, FIG. 9B is an astigmatism diagram, and FIG. 9C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 3]
Example 3
f = 4.51mm fB = 0.55mm F = 2.5 Y = 2.85mm
ENTP = 0.71mm EXTP = -2.65mm H1 = -1.12mm H2 = -3.96mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.763 0.78 1.53180 56.0 1.10
2 * 5.312 0.08 0.78
3 (Aperture) ∞ 0.72 0.77
4 * -2.710 0.53 1.53180 56.0 0.97
5 * -2.034 1.22 1.16
6 * -11.618 1.00 1.58300 30.0 1.93
7 * 7.648 0.20 2.45
8 ∞ 0.15 1.51630 64.2 2.70
9 ∞ 0.55 2.74
Imaging surface -15.500 2.85

Aspheric coefficient 1st surface 5th surface
K = -0.10300E + 00 K = -0.63405E + 01
A4 = 0.57388E-02 A4 = -0.85472E-01
A6 = 0.11203E-01 A6 = 0.34677E-01
A8 = -0.60016E-02 A8 = 0.11532E-01
A10 = 0.38959E-02 A10 = 0.16985E-01
A12 = 0.28993E-02 A12 = -0.79811E-02
A14 = -0.52019E-03
2nd side 6th side
K = 0.72402E + 01 K = 0.11593E + 02
A4 = 0.14728E-01 A4 = -0.41744E-01
A6 = 0.61533E-02 A6 = 0.60810E-02
A8 = 0.48855E-02 A8 = 0.56582E-03
A10 = 0.19220E-01 A10 = -0.78299E-04
A12 = -0.96923E-02 A12 = -0.41656E-05
A14 = 0.42255E-06
4th surface 7th surface
K = -0.58888E + 00 K = -0.14482E + 02
A4 = -0.26283E-01 A4 = -0.32779E-01
A6 = -0.62607E-01 A6 = 0.40717E-02
A8 = 0.18085E + 00 A8 = -0.60845E-03
A10 = -0.11535E + 00 A10 = 0.59961E-04
A12 = 0.25859E-01 A12 = -0.43949E-05
A14 = 0.23589E-06

Single lens data
Lens Start surface Focal length (mm)
1 1 4.614
2 4 12.044
3 6 -7.763

Example 4
Table 4 shows the lens data. FIG. 10 is a sectional view of the lens of Example 4. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 11A is a spherical aberration diagram of Example 4, FIG. 11B is an astigmatism diagram, and FIG. 11C is a distortion diagram. The aperture stop S is located closer to the object side than the object side surface position around the first lens L1 within the effective diameter of the first lens L1.

[Table 4]
Example 4
f = 4.57mm fB = 0.55mm F = 2.8 Y = 2.85mm
ENTP = 0mm EXTP = -2.65mm H1 = -1.97mm H2 = -4.02mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.18 0.82
2 * 1.722 1.24 1.54400 56.0 0.84
3 * 3.582 0.61 0.95
4 * 254.008 0.94 1.54400 56.0 1.25
5 * -2.681 0.43 1.41
6 * -3.391 0.94 1.61400 25.6 1.43
7 * 7.185 0.40 2.22
8 ∞ 0.15 1.51630 64.2 2.64
9 ∞ 0.55 2.68
Imaging surface -22.500 2.85

Aspheric coefficient 2nd surface 5th surface
K = -0.32237E + 01 K = -0.10982E + 01
A4 = 0.79745E-01 A4 = -0.17645E-01
A6 = -0.11421E-01 A6 = 0.42941E-02
A8 = 0.85483E-02 A8 = -0.44654E-02
A10 = -0.31533E-02 A10 = 0.79384E-03
3rd side 6th side
K = -0.61704E + 01 K = 0.39953E + 01
A4 = 0.66347E-01 A4 = -0.92294E-01
A6 = -0.58990E-02 A6 = 0.23502E-01
A8 = 0.24002E-01 A8 = -0.37718E-02
A10 = 0.24244E-02 A10 = -0.78052E-03
4th surface 7th surface
K = 0.30000E + 02 K = 0.39216E + 01
A4 = 0.91414E-03 A4 = -0.69071E-01
A6 = -0.37165E-03 A6 = 0.15638E-01
A8 = -0.64264E-02 A8 = -0.26100E-02
A10 = 0.43920E-02 A10 = 0.19385E-03
A12 = -0.60189E-05

Single lens Data lens Start surface Focal length (mm)
1 2 4.934
2 4 4.884
3 6 -3.630

(Example 5)
Table 5 shows the lens data. 12 is a sectional view of the lens of Example 5. FIG. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 13A is a spherical aberration diagram of Example 5, FIG. 13B is an astigmatism diagram, and FIG. 13C is a distortion diagram. The aperture stop S is located closer to the object side than the object side surface position around the first lens L1 within the effective diameter of the first lens L1.

[Table 5]
Example 5
f = 4.53mm fB = 0.71mm F = 2.6 Y = 2.85mm
ENTP = 0mm EXTP = -2.8mm H1 = -1.31mm H2 = -3.82mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.19 0.87
2 * 1.723 0.52 1.51400 57.0 0.93
3 * 3.249 0.72 0.95
4 * 5.031 0.83 1.51400 57.0 1.27
5 * -6.748 0.79 1.32
6 * -4.807 1.10 1.58300 30.0 1.31
7 * 11.482 0.40 2.14
8 ∞ 0.15 1.51630 64.2 2.58
9 ∞ 0.71 2.62
Imaging surface -14.700 2.85

Aspheric coefficient 2nd surface 5th surface
K = -0.30759E + 01 K = 0.31088E + 01
A4 = 0.82119E-01 A4 = -0.29938E-01
A6 = -0.85498E-02 A6 = 0.57524E-02
A8 = 0.12815E-01 A8 = -0.61047E-02
A10 = -0.45406E-03 A10 = 0.23419E-02
3rd side 6th side
K = -0.11322E + 02 K = 0.10880E + 02
A4 = 0.71131E-01 A4 = -0.10155E + 00
A6 = 0.30050E-02 A6 = 0.22382E-02
A8 = 0.36246E-02 A8 = -0.61655E-02
A10 = 0.11895E-01 A10 = -0.41040E-02
4th surface 7th surface
K = 0.93123E + 01 K = 0.72383E-01
A4 = -0.11423E-01 A4 = -0.49003E-01
A6 = 0.98056E-03 A6 = 0.91790E-02
A8 = -0.35459E-03 A8 = -0.22127E-02
A10 = 0.42755E-03 A10 = 0.31750E-03
A12 = -0.17564E-04

Single lens Data lens Start surface Focal length (mm)
1 2 6.403
2 4 5.745
3 6 -5.671

(Example 6)
Table 6 shows the lens data. FIG. 14 is a sectional view of the lens of Example 6. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 15A is a spherical aberration diagram of Example 6, FIG. 15B is an astigmatism diagram, and FIG. 15C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 6]
Example 6
f = 2.78mm fB = 0.31mm F = 2.6 Y = 1.85mm
ENTP = 0.49mm EXTP = -1.53mm H1 = -0.94mm H2 = -2.48mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.114 0.56 1.54400 55.9 0.71
2 * 6.628 0.03 0.48
3 (Aperture) ∞ 0.28 0.45
4 * -4.461 0.41 1.54400 55.9 0.55
5 * -2.412 0.32 0.68
6 * -3.092 1.00 1.63200 23.4 0.76
7 * 6.657 0.20 1.45
8 ∞ 0.15 1.51630 64.1 1.72
9 ∞ 0.31 1.77
Imaging surface -14.500 1.85

Aspheric coefficient 1st surface 5th surface
K = -0.12160E + 01 K = 0.86872E + 00
A4 = 0.94733E-01 A4 = -0.21433E + 00
A6 = -0.72356E-01 A6 = 0.13674E + 00
A8 = 0.17466E + 00 A8 = 0.59389E + 00
A10 = -0.30757E + 00 A10 = -0.40714E-02
2nd side 6th side
K = -0.18249E + 02 K = 0.25968E + 01
A4 = -0.65971E-01 A4 = -0.54892E + 00
A6 = 0.12690E + 00 A6 = 0.82821E + 00
A8 = -0.15307E + 01 A8 = -0.30187E + 01
A10 = 0.30224E + 01 A10 = 0.50289E + 01
A12 = -0.35674E + 01
4th surface 7th surface
K = -0.30000E + 02 K = -0.30000E + 02
A4 = -0.25260E + 00 A4 = -0.12703E + 00
A6 = -0.14956E + 00 A6 = 0.26689E-01
A8 = 0.19670E + 01 A8 = -0.74497E-02
A10 = -0.42322E + 01 A10 = 0.38231E-03
A12 = -0.29639E-03

Single lens Data lens Start surface Focal length (mm)
1 1 2.377
2 4 9.021
3 6 -3.213

(Example 7)
Table 7 shows the lens data. FIG. 16 is a sectional view of the lens of Example 7. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 17A is a spherical aberration diagram of Example 7, FIG. 17B is an astigmatism diagram, and FIG. 17C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 7]
Example 7
f = 2.84mm fB = 0.51mm F = 2.45 Y = 1.85mm
ENTP = 0.5mm EXTP = -1.6mm H1 = -0.47mm H2 = -2.33mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.056 0.54 1.54400 55.9 0.73
2 * 2.659 0.05 0.52
3 (Aperture) ∞ 0.08 0.50
4 * 5.234 0.39 1.54400 55.9 0.55
5 * -4.951 0.41 0.61
6 * -1.638 0.98 1.63200 23.4 0.67
7 * -5.913 0.16 1.32
8 ∞ 0.15 1.51630 64.1 1.65
9 ∞ 0.51 1.70
Imaging surface -9.200 1.85

Aspheric coefficient 1st surface 5th surface
K = -0.12970E + 01 K = -0.30000E + 02
A4 = 0.87396E-01 A4 = -0.40949E-01
A6 = -0.70388E-01 A6 = 0.20259E + 00
A8 = -0.19094E-01 A8 = -0.75062E + 00
A10 = -0.29963E + 00 A10 = 0.39252E + 01
2nd side 6th side
K = -0.57801E + 01 K = -0.31221E + 01
A4 = -0.84894E-01 A4 = -0.52366E + 00
A6 = -0.10270E + 00 A6 = 0.30140E + 00
A8 = -0.14552E + 01 A8 = -0.28530E + 01
A10 = 0.32416E + 01 A10 = 0.49562E + 01
A12 = -0.70845E + 01
4th surface 7th surface
K = 0.30000E + 02 K = -0.18618E + 02
A4 = -0.71909E-01 A4 = -0.94743E-01
A6 = -0.26170E + 00 A6 = 0.51780E-02
A8 = 0.12775E + 01 A8 = -0.15523E-01
A10 = -0.78859E + 00 A10 = 0.80049E-02
A12 = -0.29617E-02

Single lens data
Lens Start surface Focal length (mm)
1 1 2.882
2 4 4.741
3 6 -3.934

(Example 8)
Table 8 shows the lens data. FIG. 18 is a sectional view of the lens of Example 8. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 19A is a spherical aberration diagram of Example 8, FIG. 19B is an astigmatism diagram, and FIG. 19C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 8]
Example 8
f = 2.82mm fB = 0.31mm F = 2.5 Y = 1.85mm
ENTP = 0.51mm EXTP = -1.74mm H1 = -0.54mm H2 = -2.51mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.060 0.57 1.52560 56.4 0.72
2 * 6.690 0.03 0.51
3 (Aperture) ∞ 0.37 0.47
4 * -1.198 0.45 1.68890 31.1 0.55
5 * -1.241 0.73 0.76
6 * -4.261 0.47 1.52560 56.4 1.39
7 * 7.616 0.20 1.56
8 ∞ 0.15 1.51630 64.1 1.77
9 ∞ 0.31 1.80
Imaging surface -12.000 1.85

Aspheric coefficient 1st surface 5th surface
K = -0.20405E + 00 K = -0.14199E + 01
A4 = 0.15472E-01 A4 = 0.26853E-01
A6 = -0.53246E-01 A6 = -0.38923E-01
A8 = 0.22743E + 00 A8 = 0.94315E + 00
A10 = -0.55416E + 00 A10 = -0.65671E + 00
2nd side 6th side
K = -0.30000E + 02 K = 0.27916E + 01
A4 = -0.54684E-01 A4 = -0.90905E-01
A6 = 0.85229E-01 A6 = 0.57165E-01
A8 = -0.18595E + 01 A8 = 0.35930E-02
A10 = 0.32894E + 01 A10 = -0.41914E-02
A12 = 0.36349E-03
4th surface 7th surface
K = 0.20062E + 01 K = -0.30000E + 02
A4 = 0.28065E-01 A4 = -0.11507E + 00
A6 = 0.43035E-01 A6 = 0.31803E-01
A8 = 0.24585E + 01 A8 = -0.11649E-01
A10 = -0.46406E + 01 A10 = -0.77435E-03
A12 = 0.10178E-02

Single lens Data lens Start surface Focal length (mm)
1 1 2.314
2 4 15.553
3 6 -5.129

Example 9
Table 9 shows the lens data. FIG. 20 is a sectional view of the lens of Example 9. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. 21A is a spherical aberration diagram of Example 9, FIG. 21B is an astigmatism diagram, and FIG. 21C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 9]
Example 9
f = 2.15mm fB = 0.53mm F = 2.7 Y = 1.85mm
ENTP = 0.43mm EXTP = -1.38mm H1 = 0.15mm H2 = -1.63mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.946 0.57 1.5305 56 0.67
2 * -7.773 0.01 0.42
3 (Aperture) ∞ 0.21 0.37
4 * -4.748 0.49 1.5305 56 0.51
5 * -1.782 0.46 0.69
6 * 2.189 0.37 1.5830 30 0.98
7 * 1.598 0.23 1.28
8 ∞ 0.15 1.51680 64.2 1.57
9 ∞ 0.53 1.70
Imaging surface -5.400 1.85

Aspheric surface 1st surface 5th surface K = -0.20705E + 02
K = -0.30859E + 01 A4 = -0.74685E + 00
A4 = -0.63738E-01 A6 = 0.12707E + 01
A6 = -0.21677E-01 A8 = -0.13822E + 01
A8 = 0.43099E-01 A10 = -0.12890E + 01
A10 = -0.84565E + 00 A12 = 0.77216E + 01
A12 = 0.19609E + 01 A14 = -0.63070E + 01
A14 = -0.16028E + 01 A16 = 0.85192E + 00
2nd surface 6th surface K = -0.26273E + 02
K = -0.23392E + 02 A4 = -0.35594E + 00
A4 = -0.15652E + 00 A6 = -0.11098E + 00
A6 = 0.49971E-01 A8 = -0.91070E-02
A8 = -0.16521E + 01 A10 = 0.34150E-01
A10 = 0.19524E + 02 A12 = 0.24985E-01
A12 = -0.68324E + 02 A14 = 0.24679E-01
A16 = -0.13432E-01
4th surface 7th surface K = -0.26446E + 01
K = -0.30000E + 02 A4 = -0.34892E + 00
A4 = -0.23909E + 00 A6 = 0.17369E + 00
A6 = -0.46531E + 00 A8 = -0.81864E-01
A8 = 0.53053E + 01 A10 = 0.17254E-01
A10 = -0.15667E + 02 A12 = 0.38116E-02
A12 = 0.23459E + 02 A14 = -0.15397E-02
A16 = -0.54356E-04

Single lens Data lens Start surface Focal length (mm)
1 1 2.994
2 4 5.087
3 6 -13.234

(Example 10)
Table 10 shows the lens data. FIG. 22 is a sectional view of the lens of Example 10. In the figure, L1 is a first lens, L2 is a second lens, L3 is a third lens, S is an aperture stop, F is a seal glass or an infrared cut filter, and I is an imaging surface. FIG. 23A is a spherical aberration diagram of Example 10, FIG. 23B is an astigmatism diagram, and FIG. 23C is a distortion diagram. The aperture stop S is between the first lens L1 and the second lens L2.

[Table 10]
Example 10
f = 2.18mm fB = 0.48mm F = 2.7 Y = 1.85mm
ENTP = 0.40mm EXTP = -1.46mm H1 = 0.13mm H2 = -1.70mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.771 0.53 1.5305 56 0.67
2 * -11.638 0.01 0.42
3 (Aperture) ∞ 0.22 0.37
4 * -3.777 0.47 1.5305 56 0.51
5 * -1.812 0.43 0.69
6 * 1.387 0.30 1.5830 30 0.98
7 * 1.141 0.25 1.28
8 ∞ 0.30 1.51680 64.2 1.57
9 ∞ 0.48 1.70
Imaging surface -6.200 1.85

Aspheric coefficient 1st surface 5th surface K = -0.17379E + 02
K = -0.24212E + 01 A4 = -0.74662E + 00
A4 = -0.55857E-01 A6 = 0.12807E + 01
A6 = -0.29554E-01 A8 = -0.13593E + 01
A8 = 0.28142E-01 A10 = -0.12036E + 01
A10 = -0.87063E + 00 A12 = 0.79257E + 01
A12 = 0.19318E + 01 A14 = -0.61277E + 01
A14 = -0.16036E + 01 A16 = 0.65826E-01
2nd surface 6th surface K = -0.10865E + 02
K = -0.11103E + 02 A4 = -0.40718E + 00
A4 = -0.16085E + 00 A6 = -0.10357E + 00
A6 = 0.24540E-01 A8 = 0.17616E-01
A8 = -0.20127E + 01 A10 = 0.48897E-01
A10 = 0.21137E + 02 A12 = 0.24349E-01
A12 = -0.68324E + 02 A14 = 0.17439E-01
A16 = -0.18742E-01
4th surface 7th surface K = -0.42990E + 01
K = -0.21507E + 02 A4 = -0.35933E + 00
A4 = -0.28647E + 00 A6 = 0.17796E + 00
A6 = -0.47144E + 00 A8 = -0.81725E-01
A8 = 0.55395E + 01 A10 = 0.17288E-01
A10 = -0.15782E + 02 A12 = 0.40614E-02
A12 = 0.23459E + 02 A14 = -0.14986E-02
A16 = -0.21027E-03

Single lens data
Lens Start surface Focal length (mm)
1 1 2.938
2 4 6.059
3 6 -19.948

Table 11 summarizes the values of the conditional expressions described in the claims.

Regarding the meaning of the paraxial radius of curvature described in the claims and the examples, in the actual lens measurement scene, the vicinity of the center of the lens (specifically, the central region within 10% of the lens outer diameter) It can be considered that the approximate radius of curvature when the shape measurement value at is fitted by the least square method is the paraxial radius of curvature. For example, when a secondary aspherical coefficient is used, a curvature radius that takes into account the secondary aspherical coefficient in the reference curvature radius of the aspherical definition formula can be regarded as a paraxial curvature radius (for example, reference literature). (See pages 41-42 of “Lens Design Method” written by Yoshiya Matsui (Kyoritsu Publishing Co., Ltd.)).

The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are apparent to those skilled in the art from the embodiments and ideas described in the present specification. It is. For example, even when a dummy lens having substantially no power is further provided, it is within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Imaging lens 50 Imaging device 51a Photoelectric conversion part 51b Signal processing circuit 52 External electrode 53 Housing | casing 55 Mirror frame 60 Operation button 71 Upper housing | casing 72 Lower housing | casing 73 Hinge 100 Mobile phone B Spacer C Seal glass D1, D2 Display screen L1 First lens L2 Second lens L3 Third lens S Aperture stop SH1 Light blocking member SH2 Light blocking member

Claims (8)

An imaging lens for forming a subject image on a projection surface provided in an imaging device,
The projection surface is curved with an arbitrary cross section toward the periphery of the screen,
The imaging lens includes a first lens having a positive refractive power in order from the object side, a second lens having a positive refractive power, and a third lens having a negative refractive power,
An imaging lens satisfying the following conditional expression:
-1.1 <f12 / f3 <0 (1)
0.11 <D5 / f <0.7 (2)
-10.0 <RI / Y <-2.0 (3)
However,
f12: Composite focal length (mm) of the first lens and the second lens
f3: focal length (mm) of the third lens
D5: Axial thickness (mm) of the third lens
f: Focal length (mm) of the entire imaging lens system
RI: radius of curvature (mm) of the imaging surface of the solid-state imaging device
Y: Maximum image height (mm) The imaging lens according to claim 1, wherein the first lens has a shape with a convex surface facing the object side, and satisfies the following conditional expression.
0.7 <f1 / f <1.7 (4)
However,
f1: Focal length (mm) of the first lens The imaging lens according to claim 1, wherein the second lens has a shape with a convex surface facing the image side, and satisfies the following conditional expression.
−5 <R4 / ((n2-1) * f) <− 0.4 (5)
Where R4: radius of curvature of the image side surface of the second lens (mm)
n2: refractive index of the second lens with respect to d-line The imaging lens according to any one of claims 1 to 3, wherein an aperture stop is disposed between the first lens and the second lens. The imaging lens according to any one of claims 1 to 3, wherein an aperture stop is disposed closer to the object side than an object side surface position of the periphery of the first lens within an effective diameter of the first lens. The imaging lens according to any one of claims 1 to 5, further comprising a lens having substantially no power. 7. A solid-state image pickup device including a photoelectric conversion unit, a substrate on which the solid-state image pickup device is held and a connection terminal unit for transmitting and receiving an electric signal is formed, and any one of claims 1 to 6 An image pickup apparatus comprising: the image pickup lens described above; and a housing formed of a light-shielding material that includes the image pickup lens and has an opening for light incidence from the object side. A portable terminal comprising the imaging device according to claim 7.

Images