JP2013092584A - Imaging lens, imaging apparatus and portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small type imaging lens with an image angle of 70 degrees or more, F2.4 level and in a four piece composition, and an imaging apparatus and a portable terminal using the same.SOLUTION: The imaging lens includes: a first lens L1 having positive refractive power with a convex surface facing an object side; a second lens L2 having negative refractive power with a concave surface facing the object side; a third lens L3 having positive refractive power with a convex surface faxing an image side; and a fourth lens L4 having negative refractive power with a biconcave shape, in this order from the object side. The fourth lens L4 has an aspheric surface of a configuration having the negative refractive force become weaker as an object side surface and an image side surface go toward the periphery from the vicinity of an optical axis and an aperture diaphragm S arranged more on the object side than the second lens L2, and satisfies the following conditional expressions. -10<f1/f4<-1(1), -200<f2/f<-1.4(2), and 35<νd4<85(3) where f1: focal distance of the first lens L1, f4: focal distance of the fourth lens L4, f2: focal distance of the second lens L2, f: focal distance of the whole imaging system, and νd4: Abbe number for the fourth lens L4.

Description

  The present invention relates to an imaging lens, and more particularly to an imaging lens that uses a solid-state imaging device such as a CCD type image sensor or a CMOS type image sensor to obtain a high resolution, an imaging device including the imaging lens, and a portable terminal.

  In recent years, with the widespread use of mobile terminals equipped with solid-state imaging devices such as CCD (Charged Coupled Device) type image sensors or CMOS (Complementary Metal Oxide Semiconductor) type image sensors, higher quality images In order to obtain the above, those equipped with an imaging device using an imaging device having a high number of pixels have been supplied to the market. Conventional image pickup devices having a high number of pixels have been accompanied by an increase in size, but in recent years, pixels have become increasingly thinner and image pickup devices have become smaller. An imaging lens used for a highly thinned image sensor is required to have a high resolving power in order to cope with a highly thinned pixel. On the other hand, the resolving power of the lens is limited by the F value, and a bright imaging lens is required because a bright lens having a small F value can obtain a high resolving power.

  On the other hand, in order to further reduce the size of the imaging apparatus, it is required to further reduce the overall length of the imaging lens. There is a limit to downsizing the imaging lens by power (refractive power) arrangement, lens thickness and air spacing, and in recent years, by using a wide-angle lens with a shorter focal length, the optical system Attempts have been made to reduce the overall length. As an imaging lens for such applications, a four-lens imaging lens has been proposed because it can achieve higher performance than a three-lens lens.

  As such a four-lens imaging lens, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, and a negative refractive power in order from the object side. A so-called telephoto type imaging lens composed of a fourth lens has been developed. The telephoto type is advantageous for miniaturization of the entire length of the imaging lens (distance 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). Yes.

JP 2009-258286 JP JP 2009-282223 A JP 2009-192820 JP 2006-293324 A JP 2008-129506 A JP 2010-49113 A

  Patent Documents 1 to 3 describe an imaging lens brighter than F2.4. However, since the second lens is a negative meniscus lens having a concave surface facing the image side, the negative refractive power of the second lens must be borne only by the image side surface, so coma aberration occurs due to off-axis light flux, It is not possible to ensure good performance at the periphery of the screen.

  The imaging lenses described in Patent Documents 1 and 2 have a shooting angle of view of about 65 degrees, and it is difficult to say that the angle of view is wide. Further, when the angle of view is further increased, the influence of various aberrations, particularly the influence of coma aberration, becomes large, so that it is impossible to obtain a high resolution even though it is small.

  Furthermore, the imaging lens described in Patent Document 3 has a wide angle with a shooting field angle of about 75 degrees, but has a shape in which the peripheral portion of the fourth lens projects greatly in the image plane direction. Back focus to avoid contact with parallel flat plates such as optical low-pass filters, infrared cut filters, or solid-state image sensor package seal glass, and solid-state image sensor substrates, etc. Therefore, the size cannot be sufficiently reduced.

  On the other hand, the imaging lenses described in Patent Documents 4 to 6 are negative lenses in which the second lens has a concave surface directed toward the object side, and correction of off-axis aberrations is sufficient, but the pixel is about F2.8. In a portable terminal that is becoming increasingly thin, it is not possible to cope with an F value that can achieve high resolution. In addition, the total lens length is large, and sufficient size reduction cannot be achieved.

  The present invention has been made in view of such problems, and has a wide angle of 70 ° or more, a brightness of about F2.4, and various aberrations despite being small in size. It is an object of the present invention to provide a four-lens imaging lens, an imaging device using the same, and a portable terminal.

Here, although it is a scale of a small imaging lens, the present invention aims at miniaturization at a level satisfying the following expression. By satisfying this range, the entire imaging apparatus can be reduced in size and weight.
TL / 2Y <0.9 (13)
However,
TL: Distance 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 2Y: diagonal length of the imaging plane (diagonal length of the rectangular effective pixel area of the solid-state imaging device)
Here, the image-side focal point refers to an image point when a parallel light beam parallel to the optical axis is incident on the imaging lens.

When a parallel plate such as an optical low-pass filter, an infrared cut filter, or a seal glass of a solid-state image sensor package is disposed between the image-side surface of the imaging lens and the image-side focal position, the imaging lens is parallel. The flat plate portion is calculated as the TL value after the air conversion distance. More preferably, the range of the following formula is good.
TL / 2Y <0.8 (13) '

The imaging lens according to claim 1,
From the object side,
A first lens having positive refractive power and having a convex surface facing the object side;
A second lens having negative refractive power and having a concave surface facing the object side;
A third lens having positive refractive power and having a convex surface facing the image side;
A fourth lens having negative refractive power and a biconcave shape,
The fourth lens has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery,
An aperture stop is disposed closer to the object side than the second lens;
An imaging lens satisfying the following conditional expression:
−10 <f1 / f4 <−0.8 (1)
−200 <f2 / f <−1.4 (2)
35 <νd4 <85 (3)
However,
f1: focal length of the first lens f4: focal length of the fourth lens f2: focal length of the second lens f: focal length νd4 of the entire imaging lens system: Abbe number of the fourth lens

  The structure of the present invention for obtaining a small imaging lens with good aberration correction includes, in order from the object side, a first lens having a positive refractive power, a second lens having a negative refractive power, and a positive refractive power. This is a so-called telephoto type configuration comprising a third lens having a fourth lens and a fourth lens having a negative refractive power. This lens configuration is advantageous in reducing the overall length of the imaging lens.

  Since the first lens has a shape with a convex surface facing the object side, the principal point position of the optical system can be arranged on the object side, which is advantageous in reducing the overall length of the imaging lens.

  By forming the second lens with a concave surface facing the object side, the negative refracting power can be relatively disposed on the object side in the entire imaging lens, which is advantageous for widening the angle of the imaging lens.

  The third lens has a shape with a convex surface facing the image side, so that the chief ray incident angle of the peripheral light beam can be reduced by the convergence effect of the surface, and the fourth lens while suppressing the refraction angle of off-axis rays. Thus, off-axis aberrations can be satisfactorily suppressed.

  By making the fourth lens biconcave, the negative refracting power can be divided into the object side surface and the image side surface, so that the occurrence of aberration can be suppressed even if a strong negative refracting power is arranged on the fourth lens. This is advantageous in reducing the overall length of the imaging lens. Further, the fourth lens has an aspheric object side surface and an image side surface, and its negative refractive power becomes weaker from the optical axis to the periphery, so that the telecentric characteristics of the image side light beam can be easily secured.

  Furthermore, by arranging the aperture stop on the object side of the second lens, the exit pupil can be further distant from each other, so that the chief ray incident angle of the light beam that forms an image on the periphery of the imaging surface of the solid-state imaging device is kept small. It becomes possible.

  Conditional expression (1) is a conditional expression for appropriately reducing the focal length ratio between the first lens and the fourth lens to achieve a reduction in size and an increase in aperture due to a wide angle. Since the value of conditional expression (1) is less than the upper limit, the focal length of the first lens can be prevented from becoming too short, so the configuration is close to a retrofocus type, and it is easy to secure an incident angle of view. The imaging lens can be widened. Furthermore, since the generation of spherical aberration can be suppressed, a large aperture can be achieved. In addition, since it is possible to suppress the focal length of the fourth lens from becoming too long, it is possible to prevent the back focus from becoming long and to reduce the size of the imaging lens.

On the other hand, when the value of conditional expression (1) exceeds the lower limit, the focal length of the first lens can be prevented from becoming too long, and the principal point position of the imaging lens can be arranged on the object side, so that the imaging lens can be downsized. It becomes easy. In addition, the focal length of the fourth lens can be prevented from becoming too short, and the occurrence of distortion can be suppressed. More preferably, the range of the following formula is good.
−6 <f1 / f4 <−1.0 (1 ′)
More desirably, the range is within the following formula.
-3 <f1 / f4 <-1.1 (1 ")

  Conditional expression (2) is a conditional expression for achieving a wide angle and high performance by appropriately setting the focal length of the second lens. When the value of conditional expression (2) is less than the upper limit, the negative focal length of the second lens becomes too short, and the principal point position of the imaging lens can be prevented from being arranged on the image side. Telecentric characteristics can be obtained. Furthermore, the occurrence of spherical aberration and coma can be suppressed, and high performance can be achieved.

On the other hand, when the value of conditional expression (2) exceeds the lower limit, the focal length of the second lens can be prevented from becoming too long, and the negative refractive power can be appropriately maintained. A negative refractive power can be arranged on the object side, and a wide angle can be achieved. More preferably, the range of the following formula is good.
−100 <f2 / f <−1.5 (2 ′)
The range of the following formula is more desirable.
-50 <f2 / f <-1.6 (2 ")

Conditional expression (3) is a conditional expression for appropriately setting the dispersion characteristic of the fourth lens and appropriately correcting chromatic aberration. Since the fourth lens has an aspherical shape in which negative refractive power decreases as it goes from the vicinity of the optical axis to the periphery, it is possible to correct axial chromatic aberration and lateral chromatic aberration in a balanced manner by satisfying the conditional expression. Become. More specifically, when the value of conditional expression (3) is less than the upper limit, it is possible to suppress further deterioration of longitudinal chromatic aberration. On the other hand, when the value of conditional expression (3) exceeds the lower limit, it is possible to suppress deterioration of lateral chromatic aberration. More preferably, the range of the following formula is good.
35 <νd4 <75 (3 ′)
The range of the following formula is more desirable.
35 <νd4 <65 (3 “)

  More desirably, if the image side surface of the fourth lens has an aspherical shape having an inflection point at a position other than the intersection with the optical axis, the telecentric characteristics of the image-side light beam can be easily secured. Here, the “inflection point” is a point on the aspheric surface where the tangent plane of the aspherical vertex is a plane perpendicular to the optical axis in the curve of the lens cross-sectional shape within the effective radius.

The imaging lens described in claim 2 is characterized in that, in the invention described in claim 1, the following conditional expression is satisfied.
0.1 <T12 / T23 <2.5 (4)
However,
T12: Air spacing on the optical axis of the first lens and the second lens T23: Air spacing on the optical axis of the second lens and the third lens

  Conditional expression (4) is a conditional expression for satisfactorily correcting aberrations by determining the distance between the first lens and the second lens and the ratio of the distance between the second lens and the third lens. When the value of conditional expression (4) is less than the upper limit, it is possible to suppress the negative refractive power of the second lens from being excessive on the image side, and thus it is possible to widen the imaging lens. Furthermore, since the second lens and the third lens can be arranged at a suitable distance, a difference in the height of the off-axis light beam passing therethrough can be provided, and correction of coma aberration is facilitated.

On the other hand, when the value of conditional expression (4) exceeds the lower limit, an aperture stop can be disposed between the first lens and the second lens. Furthermore, since the first lens and the second lens can be arranged at a suitable distance, a difference in the height of the axial light flux passing through the first lens and the second lens can be provided, and the correction of the spherical aberration is easy. Therefore, a large aperture can be achieved. More preferably, the range of the following formula is good.
0.15 <T12 / T23 <2.0 (4 ′)
The range of the following formula is more desirable.
0.20 <T12 / T23 <1.5 (4 ")

The imaging lens described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the following conditional expression is satisfied.
0.6 <f1 / f <5.0 (5)
However,
f1: Focal length of the first lens f: Focal length of the entire imaging lens system

  Conditional expression (5) is a conditional expression for appropriately setting the focal length of the first lens to achieve miniaturization and high performance. When the value of conditional expression (5) is less than the upper limit, the focal length of the first lens does not become too long, and the principal point position of the entire imaging lens system can be suppressed from being on the image side. It becomes possible.

On the other hand, if the value of conditional expression (5) exceeds the lower limit, the focal length of the first lens is not too short, and the occurrence of spherical aberration and coma generated in the first lens can be suppressed. Large diameter and wide angle can be achieved while maintaining. More preferably, the range of the following formula is good.
0.65 <f1 / f <3.0 (5)
The range of the following formula is more desirable.
0.75 <f1 / f <2.0 (5 ")

Furthermore, it is desirable that the first lens has a shape that satisfies the following conditional expression.
−6 <(r1 + r2) / (r1−r2) ≦ −1 (14)
However,
r1: radius of curvature of the object side surface of the first lens r2: radius of curvature of the image side surface of the first lens

Conditional expression (14) is a conditional expression for setting the shape of the first lens appropriately to achieve both shortening of the entire length of the imaging lens and suppression of coma generated in the first lens. Conditional expression (14) defines a so-called shaping factor that represents the shape of the first lens. In the range of the conditional expression, the first lens is set in a meniscus range with the convex surface facing the object side from the plano-convex lens. The When the value of conditional expression (14) is below the upper limit, the first lens has a meniscus shape, so that the principal point position of the entire imaging lens system can be moved closer to the object side. Shortening can be performed. On the other hand, when the value of conditional expression (14) exceeds the lower limit, the radius of curvature of the side surface of the first lens object does not become too small, and coma aberration with respect to ambient light with a large angle of view can be suppressed to a small value. More preferably, the range of the following formula is good.
−5 <(r1 + r2) / (r1−r2) ≦ −1 (14 ′)
The range of the following formula is more desirable.
-4 <(r1 + r2) / (r1-r2) ≤-1 (14 ")

The imaging lens of Claim 4 satisfies the following conditional expressions in the invention of any one of Claims 1-3.
0.3 <f3 / f <1.5 (6)
However,
f3: focal length of the third lens f: focal length of the entire imaging lens system

  Conditional expression (6) is a conditional expression for setting the focal length of the third lens appropriately to achieve both miniaturization and good aberration correction. When the value of conditional expression (6) is less than the upper limit, it is possible to prevent the positive refractive power of the third lens from becoming weak due to a long focal distance, so that the positive refractive power can be appropriately maintained. As a result, the exit pupil position can be moved away from the solid-state image sensor to the object side, so that the chief ray incident angle (the angle formed between the principal ray and the optical axis) If the optical axis or the optical axis is parallel, O °) can be kept small. As a result, it is possible to suppress a phenomenon (shading) in which the substantial aperture efficiency decreases in the periphery of the imaging surface.

On the other hand, since the value of conditional expression (6) exceeds the lower limit, the focal length is shortened and the positive refractive power of the third lens can be suppressed from becoming stronger than necessary. Arranged on the object side, the total lens length can be shortened. Further, it is possible to satisfactorily correct off-axis aberrations such as field curvature and distortion. More preferably, the range of the following formula is good.
0.3 <f3 / f <1.3 (6 ′)
The range of the following formula is more desirable.
0.35 <f3 / f <1.1 (6 ")

Furthermore, it is desirable that the third lens has a shape that satisfies the following conditional expression.
1.0 ≦ (r5 + r6) / (r5-r6) <6.0 (15)
However,
r5: radius of curvature of the object side surface of the third lens r6: radius of curvature of the image side surface of the third lens

Conditional expression (15) defines a so-called shaping factor that represents the shape of the third lens. In the range of the conditional expression, the third lens is set to a meniscus-shaped range with the convex surface facing the image side from the plano-convex lens. The When the value of conditional expression (15) is less than the upper limit, the third lens has a meniscus shape, so that the object side surface has a concave shape, and the angle of light incident on the object side surface can be reduced, thereby suppressing the occurrence of aberrations. be able to. On the other hand, since the value of conditional expression (15) exceeds the lower limit, the curvature radius of the third lens object side surface can be suppressed from becoming too small. Therefore, the total lens length can be shortened. More preferably, the range of the following formula is good.
1.2 <(r5 + r6) / (r5-r6) <4.0 (15 ′)
The range of the following formula is more desirable.
1.4 <(r5 + r6) / (r5-r6) <3.0 (15 ")

The imaging lens of Claim 5 satisfies the following conditional expressions in the invention in any one of Claims 1-4, It is characterized by the above-mentioned.
0.001 <T34 / f <0.3 (7)
However,
T34: Air space on the optical axis of the third lens and the fourth lens

  Conditional expression (7) is a conditional expression for achieving both miniaturization and good aberration correction by appropriately setting the distance between the third lens and the fourth lens. When the value of conditional expression (7) is less than the upper limit, it is possible to prevent the entire length of the imaging lens from increasing. Furthermore, it is possible to suppress the back focus from becoming too short and increase the effective radius of the fourth lens, and to reduce the size of the imaging lens.

On the other hand, if the value of conditional expression (7) exceeds the lower limit, the distance between the third lens and the fourth lens can be maintained moderately, so the positive refractive power on the image side surface of the third lens is set stronger than necessary. This makes it easier to correct coma and curvature of field, and enables widening the angle while maintaining high performance. More preferably, the range of the following formula is good.
0.005 <T34 / f <0.25 (7 ')

The imaging lens of Claim 6 satisfies the following conditional expressions in the invention in any one of Claims 1-5, It is characterized by the above-mentioned.
−1.0 <(r7 + r8) / (r7−r8) <1.0 (8)
However,
r7: radius of curvature of the object side surface of the fourth lens r8: radius of curvature of the image side surface of the fourth lens

  Conditional expression (8) is a conditional expression for appropriately setting the shape of the fourth lens and achieving shortening of the optical total length. Within the range of the conditional expression, the fourth lens is biconcave. When the value of conditional expression (8) is less than the upper limit, the negative refractive power of the image side surface becomes too strong and the light rays do not diverge too much, and the telecentricity can be improved while shortening the total length.

On the other hand, if the value of conditional expression (8) exceeds the lower limit, the negative refracting power on the object side surface becomes too strong, and the refracting power does not become too weak on the image side surface. Thus, the back focus of the imaging lens can be sufficiently secured while shortening the overall length. More preferably, the range of the following formula is good.
−0.5 <(r7 + r8) / (r7−r8) <1.0 (8 ′)

Within the range of the conditional expression, the fourth lens has a biconcave shape having a strong negative refractive power on the image side surface. Satisfying conditional expression (8 ′) suppresses an increase in the effective radius of the fourth lens, because the divergence of light rays on the side surface of the image is maintained moderately and the back focus is secured while being too short. The total length can be shortened. The range of the following formula is more desirable.
0 <(r7 + r8) / (r7-r8) <1.0 (8 ")

The imaging lens of Claim 7 satisfies the following conditional expressions in the invention in any one of Claims 1-6, It is characterized by the above-mentioned.
-5.0 <P _air12 /P<-0.1 (9)
However,
P: refractive power of the entire imaging lens system (reciprocal of focal length)
P _air12 : Refractive power of a so-called air lens formed by the image side surface of the first lens and the object side surface of the second lens, which is obtained by the following conditional expression.
P _air12 = (1-N1) / R2 + (N2-1) / R3-{((1-N1) · (N2-1)) / (R2 · R3)} · D2 (10)
However,
N1: Refractive index with respect to d line of the first lens N2: Refractive index with respect to d line of the second lens R2: Radius of curvature of the image side surface of the first lens R3: Radius of curvature of the object side surface of the second lens D2: Air spacing on the optical axis of the first lens and the second lens

  Conditional expression (9) is a conditional expression for improving the image plane correction and lens processability by making the refractive power of the air lens formed by the first lens and the second lens appropriate. When the value of conditional expression (9) is less than the upper limit, the negative refractive power of the air lens can be maintained, so that the Petzval sum does not become too large and the image plane can be flattened.

On the other hand, if the value of conditional expression (9) exceeds the lower limit, the negative refractive power by the air lens does not become too strong, so when a relative axial misalignment between the first lens and the second lens occurs during manufacturing, A good image with little performance deterioration can be obtained. More preferably, the range of the following formula is good.
−3.5 <P _air12 /P<−0.2 (9 ′)
The range of the following formula is more desirable.
-2.5 <P _air12 /P<-0.3 (9 ")

An imaging lens according to an eighth aspect of the invention according to any one of the first to seventh aspects satisfies the following conditional expression.
50 <νd1 <97 (11)
15 <νd2 <29 (12)
However,
νd1: Abbe number of the first lens νd2: Abbe number of the second lens

  Conditional expressions (11) and (12) are conditional expressions for appropriately setting the Abbe numbers of the first lens and the second lens and correcting chromatic aberration satisfactorily. By using a low-dispersion lens material that satisfies the conditional expression (11) for the first lens, the longitudinal chromatic aberration can be sufficiently corrected. Further, by using a highly dispersed lens material that satisfies the conditional expression (12) for the second lens, it is possible to correct axial chromatic aberration and lateral chromatic aberration in a balanced manner.

  An imaging lens according to a ninth aspect is characterized in that, in the invention according to any one of the first to eighth aspects, the aperture stop is disposed closer to the object side than the object side surface of the first lens.

  Arranging the aperture stop closer to the object side than the object side surface of the first lens is advantageous in ensuring good telecentric characteristics because the exit pupil can be further distant.

  According to a tenth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the aperture stop is disposed between the first lens and the second lens.

  If an aperture stop is disposed between the first lens and the second lens, it becomes easy to correct distortion aberration and coma aberration, which is advantageous for high performance.

  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 has substantially no refractive power. That is, even when a dummy lens having substantially no refractive power is added to the configuration of claim 1, it is within the scope of application of the present invention.

  An imaging apparatus according to a twelfth aspect includes a solid-state imaging element that photoelectrically converts a subject image and the imaging lens according to any one of the first to eleventh aspects. By using the imaging lens of the present invention, a smaller and higher performance imaging device can be obtained.

  According to a thirteenth aspect of the present invention, there is provided a mobile terminal including the imaging device according to the twelfth 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, a four-lens imaging lens having a wide field of view of 70 degrees or more, a brightness of about F2.4, and various aberrations corrected satisfactorily while being small in size. And an imaging device and a portable terminal using the same can be provided.

It is a perspective view of the imaging unit 50 concerning this Embodiment. 3 is a diagram schematically showing a cross section along the optical axis of an imaging optical system of the imaging unit 50. FIG. It is the front view (a) of the mobile phone to which the imaging unit is applied, and the rear view (b) of the mobile phone to which the imaging unit is applied. It is a control block diagram of the smart phone of FIG. 3 is a cross-sectional view in the optical axis direction of the imaging lens of Example 1. FIG. FIG. 4 is an aberration diagram of Example 1 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). FIG. 6 is a cross-sectional view in the optical axis direction of the imaging lens of Example 2. FIG. 6 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 6 is a cross-sectional view in the optical axis direction of the imaging lens of Embodiment 3. FIG. FIG. 6 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 6 is a cross-sectional view in the optical axis direction of an imaging lens of Example 4. FIG. FIG. 6 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 6 is a cross-sectional view in the optical axis direction of the imaging lens of Example 5. FIG. FIG. 6 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 7 is a cross-sectional view in the optical axis direction of an imaging lens of Example 6. FIG. FIG. 10 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 10 is a cross-sectional view in the optical axis direction of an imaging lens of Example 7. FIG. FIG. 6 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). FIG. 10 is a cross-sectional view in the optical axis direction of the imaging lens of Example 8. FIG. 10 is an aberration diagram of Example 8 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). 10 is a cross-sectional view in the optical axis direction of an imaging lens of Example 9. FIG. FIG. 10 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). FIG. 12 is a cross-sectional view in the optical axis direction of the imaging lens of Example 10. FIG. 10 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 14 is a cross-sectional view in the optical axis direction of the imaging lens of Example 11. FIG. FIG. 10 is an aberration diagram of Example 11 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 14 is a cross-sectional view in the optical axis direction of the imaging lens of Example 12. FIG. FIG. 10 is an aberration diagram of Example 12 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). FIG. 16 is a cross-sectional view in the optical axis direction of the imaging lens of Example 13. FIG. 10 is an aberration diagram of Example 13 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). FIG. 22 is a cross-sectional view in the optical axis direction of the imaging lens of Example 14; FIG. 10 is an aberration diagram of Example 14 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). 18 is a cross-sectional view in the optical axis direction of the imaging lens of Example 15. FIG. FIG. 10 is an aberration diagram of Example 15 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 18 is a cross-sectional view in the optical axis direction of the imaging lens of Example 16. FIG. FIG. 10 is an aberration diagram of Example 16 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). 18 is a cross-sectional view in the optical axis direction of the imaging lens of Example 17. FIG. FIG. 10 is an aberration diagram of Example 17 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). FIG. 22 is a cross-sectional view in the optical axis direction of the imaging lens of Example 18; FIG. 10 is an aberration diagram of Example 18 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). FIG. 25 is a cross-sectional view in the optical axis direction of the imaging lens of Example 19; FIG. 10 is an aberration diagram of Example 18 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). FIG. 22 is a cross-sectional view in the optical axis direction of the imaging lens of Example 20; FIG. 10 is an aberration diagram of Example 20 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an imaging unit 50 according to the present embodiment, and FIG. 2 is a diagram schematically showing a cross section along the optical axis of the imaging optical system of the imaging unit 50.

  As shown in FIG. 1, the imaging unit 50 includes a CMOS type imaging device 51 as a solid-state imaging device having a photoelectric conversion unit 51a, an imaging lens 10 that causes the photoelectric conversion unit 51a of the imaging device 51 to capture a subject image, A substrate 52 connected to an external connection terminal (also referred to as an external connection terminal) 54 that holds the image sensor 51 and transmits / receives an electric signal thereof, and has an opening for light incidence from the object side. And a case 53 as a lens barrel, which are integrally formed.

  As shown in FIG. 2, the imaging element 51 has a photoelectric conversion part 51 a as a light receiving part in which pixels (photoelectric conversion elements) are two-dimensionally arranged at the center of the plane on the light receiving side. A signal processing circuit (not shown) is formed around the periphery. 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 in the vicinity of the outer edge of the plane on the light receiving side of the image sensor 51, and are connected to the substrate 52 via wires (not shown). The image sensor 51 converts the signal charge from the photoelectric conversion unit 51 a into an image signal such as a digital YUV signal, and outputs it to a predetermined circuit on the substrate 52 via the wire W. Here, Y is a luminance signal, U (= R−Y) 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 image sensor is not limited to the above CMOS image sensor, and other devices such as a CCD may be used.

  The substrate 52 includes a support flat plate 52a that supports the image sensor 51 and the housing 53 on the upper surface thereof, and a flexible substrate 52b having one end connected to the lower surface of the support flat plate 52a (the surface opposite to the image sensor 51). It has.

  Although not shown, the support flat plate 52a has a large number of signal transmission pads, and is connected to the image sensor 51 via a wiring (not shown).

  In FIG. 1, as described above, one end of the flexible substrate 52b is connected to the support flat plate 52a, and the support flat plate 52a and an external circuit (for example, an image pickup unit are mounted) via an external connection terminal 54 provided at the other end. Connected to the control circuit of the host device, and can be supplied with a voltage and a clock signal for driving the imaging device 51 from an external circuit, or can output a digital YUV signal to the external circuit. And Furthermore, the intermediate portion in the longitudinal direction of the flexible substrate 52b has flexibility or deformability, and the deformation gives the freedom to the orientation and arrangement of the external connection terminals 54 with respect to the support flat plate 52a.

  In FIG. 2, the housing 53 is fixedly disposed on the surface of the support plate 52 a of the substrate 52 on which the image sensor 51 is provided so as to cover the image sensor 51. That is, the casing 53 is wide open so that the part on the image sensor 51 side surrounds the image sensor 51, and the other end (object side end) forms a flange 53a having a small opening. An end on the image sensor 51 side (image side end) is abutted and fixed on the support flat plate 52a. Note that the end of the housing 53 on the image sensor 51 side may be fixed in contact with the periphery of the photoelectric conversion unit 51 a on the image sensor 51.

  A cover glass CG is fixed between the imaging lens 10 and the imaging element 51 inside the housing 53 in which the flange portion 53a provided with a small opening (an opening for light incidence) is directed toward the object side. Has been placed. Besides this, an IR (infrared) cut filter may be provided.

The imaging lens 10 disposed in the housing 53 has, in order from the object side, a first lens L1 having a positive refractive power and a convex surface facing the object side, and a negative lens having a negative refractive power and a concave surface facing the object side. The second lens L2, the third lens L3 having a positive refractive power and having a convex surface facing the image side, and the fourth lens L4 having a negative refractive power and a biconcave shape. The lenses L1 to L4 are held at predetermined intervals by spacers SP arranged between adjacent lenses. The fourth lens L4 has an aspheric object side surface and an image side surface, has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is more object-oriented than the second lens L2. The following conditional expression is satisfied.
−10 <f1 / f4 <−1 (1)
−200 <f2 / f <−1.4 (2)
35 <νd4 <85 (3)
However,
f1: focal length of the first lens L1 f4: focal length of the fourth lens L4 f2: focal length of the second lens L2 f: focal length νd4 of the entire imaging lens system: Abbe number of the fourth lens L4 FIG. 2, the upper side is the object side and the lower side is the image side.

  Although illustration is omitted, an external light shielding mask for minimizing the incidence of unnecessary light from outside may be provided on the object side further than the first lens L1. The aperture stop S is a member that determines the F number of the entire imaging lens system. A spacer SP is also disposed between the fourth lens L4 and the cover glass CG.

  The operation of the imaging unit 50 described above will be described. FIG. 3 shows a state in which the imaging unit 50 is installed in a smartphone 100 as a mobile terminal. FIG. 4 is a control block diagram of the smartphone 100.

  For example, the object-side end surface of the housing 53 is provided on the back surface of the smartphone 100 (see FIG. 3B), and the imaging unit 50 is disposed at a position corresponding to the lower side of the liquid crystal display unit.

  The external connection terminal 54 (arrow in FIG. 4) of the imaging unit 50 is connected to the control unit 101 of the smartphone 100, and outputs an image signal such as a luminance signal or a color difference signal to the control unit 101 side.

  On the other hand, as shown in FIG. 4, the smartphone 100 performs overall control of each unit, and also inputs a control unit (CPU) 101 that executes a program corresponding to each process, and inputs a number and the like with a key. Unit 60, a liquid crystal display unit 70 for displaying captured images in addition to predetermined data, a wireless communication unit 80 for realizing various information communication with an external server, a system program for mobile phone 100, Obtained by a storage unit (ROM) 91 storing various processing programs and necessary data such as a terminal ID, and various processing programs and data executed by the control unit 101, or processing data, or the imaging unit 50 And a temporary storage unit (RAM) 92 that is used as a work area for temporarily storing imaging data and the like.

The smartphone 100 operates by operating the input key unit 60, and can touch the icon 71 and the like displayed on the touch panel 70 to operate the imaging unit 50 to perform imaging. The image signal input from the imaging unit 50 is stored in the storage unit 92 or displayed on the touch panel 70 by the control system of the smartphone 100, and further transmitted to the outside as video information via the wireless communication unit 80. Is done.
[Example]

Examples of the imaging lens of the present invention will be shown below. Symbols used in each example are as follows.
f: Focal length of the entire imaging lens fB: Back focus F: F number 2ω: Shooting angle of view 2Y: Diagonal length of the imaging surface of the solid-state imaging device
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)
R: radius of curvature D: axial distance Nd: refractive index νd of lens material with respect to d-line: Abbe number of lens material

  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 aspheric coefficient R: radius of curvature K: conic constant

  Regarding the meaning of the paraxial radius of curvature described in the claims and the examples, in the actual lens measurement scene, in the vicinity of the center of the lens (specifically, the central region within 10% of the lens outer diameter) ) Can be regarded as the paraxial curvature radius when fitting the shape measurement value in the least square method. For example, when a secondary aspherical coefficient is used, a radius of curvature that takes into account the secondary aspherical coefficient in the reference curvature radius of the aspherical definition formula can be regarded as the paraxial curvature radius. (For example, refer to P41-42 of “Lens Design Method” written by Yoshiya Matsui (Kyoritsu Publishing Co., Ltd.) as a reference)

Example 1
Table 1 shows lens data of Example 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).

[Table 1]
Example 1

f = 3.06mm fB = 0.11mm F = 2.1 2ω = 86 ° 2Y = 5.8mm
ENTP = 0mm EXTP = -2.47mm H1 = -0.57mm H2 = -2.95mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.11 0.73
2 * 1.500 0.59 1.5447 56 0.75
3 * 5.179 0.33 0.81
4 * -4.186 0.29 1.6510 21 0.81
5 * -6.296 0.32 0.92
6 * -3.125 0.66 1.5447 56 1.21
7 * -0.883 0.41 1.38
8 * -8.744 0.32 1.5447 56 1.97
9 * 1.213 0.64 2.41
10 ∞ 0.35 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.30147E-01 K = 0.3272E + 01
A4 = -0.83898E-02 A4 = -0.52583E-02
A6 = 0.18863E-01 A6 = 0.97220E-01
A8 = -0.81677E-01 A8 = -0.35544E-01
A10 = 0.14043E + 00 A10 = -0.61285E-01
A12 = -0.19535E + 00 A12 = 0.70343E-01
A14 = -0.22057E-01

3rd surface 7th surface
K = -0.14555E + 02 K = -0.37223E + 01
A4 = -0.38994E-01 A4 = -0.20371E + 00
A6 = -0.83415E-01 A6 = 0.24172E + 00
A8 = -0.29394E-02 A8 = -0.12840E + 00
A10 = -0.14923E + 00 A10 = 0.27103E-01
A12 = -0.88531E-01 A12 = 0.88721E-02
A14 = -0.41419E-02

4th side 8th side
K = 0.18655E + 02 K = 0.32099E + 01
A4 = -0.17851E + 00 A4 = -0.87650E-02
A6 = -0.39578E-01 A6 = -0.13975E-01
A8 = -0.35103E-01 A8 = 0.26627E-02
A10 = 0.64043E-01 A10 = 0.37524E-03
A12 = 0.14813E + 00 A12 = -0.23856E-04
A14 = -0.18705E + 00 A14 = -0.89056E-05

5th surface 9th surface
K = 0.22455E + 02 K = -0.72583E + 01
A4 = -0.85770E-01 A4 = -0.54241E-01
A6 = 0.66954E-01 A6 = 0.23451E-01
A8 = -0.72231E-01 A8 = -0.99389E-02
A10 = 0.16317E + 00 A10 = 0.25085E-02
A12 = -0.15548E-01 A12 = -0.34235E-03
A14 = -0.70478E-02 A14 = 0.18872E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.67
2 4 -20.27
3 6 2.05
4 8 -1.93

  5 is a sectional view of the lens of Example 1. FIG. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 6 is an aberration diagram of Example 1 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the following aberration diagrams, in the spherical aberration diagram, the solid line represents the d-line and the dotted line represents the g-line, and in the astigmatism diagram, the solid line S represents the sagittal image plane, and the dotted line M represents the meridional image plane. In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 2)
Table 2 shows lens data of the imaging lens of Example 2.

[Table 2]
Example 2

f = 3.78mm fB = 0.07mm F = 2.4 2ω = 78 ° 2Y = 6.2mm
ENTP = 0mm EXTP = -3.34mm H1 = -0.41mm H2 = -3.71mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.11 0.79
2 * 1.656 0.52 1.5447 56 0.80
3 * 6.104 0.46 0.83
4 * -8.344 0.23 1.6347 24 0.85
5 * -39.968 0.54 0.97
6 * -2.555 0.72 1.5447 56 1.21
7 * -0.719 0.05 1.44
8 * -369.984 0.50 1.5489 50 1.92
9 * 0.864 1.16 2.27
10 ∞ 0.50 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = -0.38615E-01 K = 0.10572E + 01
A4 = -0.16380E-01 A4 = -0.17795E-01
A6 = 0.32061E-01 A6 = 0.11006E + 00
A8 = -0.15407E + 00 A8 = -0.48581E-01
A10 = 0.19403E + 00 A10 = -0.86865E-01
A12 = -0.13145E + 00 A12 = 0.99059E-01
A14 = -0.28809E-01

3rd surface 7th surface
K = -0.12663E + 02 K = -0.41123E + 01
A4 = -0.34636E-01 A4 = -0.20929E + 00
A6 = -0.76570E-01 A6 = 0.27156E + 00
A8 = 0.50155E-01 A8 = -0.17056E + 00
A10 = -0.69382E-01 A10 = 0.34477E-01
A12 = 0.38352E-02 A12 = 0.13503E-01
A14 = -0.50239E-02

4th side 8th side
K = -0.34162E + 02 K = -0.10000E + 02
A4 = -0.15159E + 00 A4 = -0.12640E-01
A6 = 0.91415E-02 A6 = -0.18877E-01
A8 = -0.59791E-01 A8 = 0.35112E-02
A10 = 0.55533E-01 A10 = 0.69765E-03
A12 = 0.24474E + 00 A12 = -0.36370E-05
A14 = -0.18975E + 00 A14 = -0.27996E-04

5th side 9th side
K = 0.50,000E + 02 K = -0.76680E + 01
A4 = -0.73359E-01 A4 = -0.68937E-01
A6 = 0.54724E-01 A6 = 0.28326E-01
A8 = -0.10062E + 00 A8 = -0.12150E-01
A10 = 0.18834E + 00 A10 = 0.31889E-02
A12 = -0.50482E-01 A12 = -0.47433E-03
A14 = -0.64678E-02 A14 = 0.30108E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 4.01
2 4 -16.66
3 6 1.61
4 8 -1.57

  FIG. 7 is a sectional view of the lens of Example 2. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 8 is an aberration diagram of Example 2 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 3)
Table 3 shows lens data of the imaging lens of Example 3.

[Table 3]
Example 3

f = 3.84mm fB = 0.09mm F = 2.4 2ω = 76 ° 2Y = 6mm
ENTP = 0mm EXTP = -3.20mm H1 = -0.65mm H2 = -3.75mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.13 0.80
2 * 1.488 0.62 1.5447 56 0.84
3 * 4.861 0.32 0.87
4 * -6.700 0.23 1.6347 24 0.87
5 * -127.558 0.56 0.94
6 * -3.078 0.81 1.5447 56 1.17
7 * -0.915 0.22 1.45
8 * -400.000 0.43 1.5447 56 2.07
9 * 1.138 1.12 2.38
10 ∞ 0.30 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = -0.13773E + 00 K = 0.30827E + 00
A4 = 0.86507E-02 A4 = -0.13349E-01
A6 = 0.20416E-01 A6 = 0.38107E-02
A8 = -0.61096E-01 A8 = 0.14070E-02
A10 = 0.96096E-01 A10 = -0.25548E-01
A12 = -0.81283E-01 A12 = 0.17669E-01
A14 = -0.41764E-02

3rd surface 7th surface
K = -0.65991E + 01 K = -0.40584E + 01
A4 = -0.14594E-01 A4 = -0.17770E + 00
A6 = -0.10386E + 00 A6 = 0.15300E + 00
A8 = 0.12528E + 00 A8 = -0.990314E-01
A10 = -0.31111E + 00 A10 = 0.25444E-01
A12 = 0.15734E + 00 A12 = 0.37283E-02
A14 = -0.22399E-02

4th side 8th side
K = 0.48750E + 02 K = 0.55229E-10
A4 = -0.10327E + 00 A4 = -0.92393E-01
A6 = -0.24522E-01 A6 = 0.26945E-01
A8 = -0.10408E + 00 A8 = -0.16748E-02
A10 = -0.39045E-01 A10 = -0.15538E-03
A12 = 0.22110E + 00 A12 = -0.10630E-04
A14 = 0.37626E-05

5th side 9th side
K = 0.00000E + 00 K = -0.777711E + 01
A4 = -0.20742E-01 A4 = -0.74947E-01
A6 = -0.28921E-01 A6 = 0.22787E-01
A8 = 0.67774E-01 A8 = -0.54415E-02
A10 = -0.74503E-01 A10 = 0.73767E-03
A12 = 0.11875E + 00 A12 = -0.50761E-04
A14 = 0.13325E-05

Single lens data

Lens Start surface Focal length (mm)
1 2 3.70
2 4 -11.15
3 6 2.11
4 8 -2.08

  FIG. 9 is a sectional view of the lens of Example 3. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 10 is an aberration diagram of Example 3 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

Example 4
Table 4 shows lens data of the imaging lens of Example 4.

[Table 4]
Example 4

f = 3.06mm fB = 0.10mm F = 2.1 2ω = 86 ° 2Y = 5.8mm
ENTP = 0.50mm EXTP = -2.31mm H1 = -0.32mm H2 = -2.95mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.410 0.49 1.5447 56 0.86
2 * 4.016 0.10 0.71
3 (Aperture) ∞ 0.31 0.65
4 * -4.078 0.26 1.6510 21 0.74
5 * -4.898 0.31 0.89
6 * -2.814 0.67 1.5447 56 1.21
7 * -0.868 0.38 1.45
8 * -6.276 0.31 1.5447 56 2.00
9 * 1.318 0.66 2.38
10 ∞ 0.40 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

1st side 6th side
K = 0.99692E-01 K = 0.18574E + 01
A4 = -0.26783E-02 A4 = -0.20977E-01
A6 = 0.26894E-01 A6 = 0.10071E + 00
A8 = -0.83089E-01 A8 = -0.31422E-01
A10 = 0.15472E + 00 A10 = -0.59314E-01
A12 = -0.17570E + 00 A12 = 0.70731E-01
A14 = -0.21695E-01

2nd surface 7th surface
K = 0.54948E + 01 K = -0.36845E + 01
A4 = -0.16236E-01 A4 = -0.21987E + 00
A6 = -0.71824E-01 A6 = 0.24034E + 00
A8 = 0.17011E-01 A8 = -0.12553E + 00
A10 = -0.12224E + 00 A10 = 0.28158E-01
A12 = -0.45981E-01 A12 = 0.89338E-02
A14 = -0.42701E-02

4th side 8th side
K = 0.17958E + 02 K = -0.39931E + 01
A4 = -0.15624E + 00 A4 = -0.60568E-02
A6 = -0.65068E-01 A6 = -0.12494E-01
A8 = -0.47143E-01 A8 = 0.25998E-02
A10 = 0.82095E-01 A10 = 0.32591E-03
A12 = 0.18875E + 00 A12 = -0.32742E-04
A14 = -0.11447E + 00 A14 = -0.74188E-05

5th side 9th side
K = 0.13197E + 02 K = -0.83586E + 01
A4 = -0.86630E-01 A4 = -0.56349E-01
A6 = 0.51756E-01 A6 = 0.24474E-01
A8 = -0.95635E-01 A8 = -0.10101E-01
A10 = 0.16034E + 00 A10 = 0.24830E-02
A12 = 0.85307E-02 A12 = -0.33960E-03
A14 = 0.32451E-01 A14 = 0.19230E-04

Single lens data

Lens Start surface Focal length (mm)
1 1 3.74
2 4 -42.72
3 6 2.05
4 8 -1.97

  FIG. 11 is a sectional view of the lens of Example 4. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 12 is an aberration diagram of Example 4 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. It is disposed between the first lens L1 and the second lens L1.

(Example 5)
Table 5 shows lens data of the imaging lens of Example 5.

[Table 5]
Example 5

f = 2.67mm fB = 0.14mm F = 2.4 2ω = 94 ° 2Y = 5.8mm
ENTP = 0mm EXTP = -2.35mm H1 = -0.18mm H2 = -2.52mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.06 0.56
2 * 1.415 0.35 1.5447 56 0.56
3 * 3.746 0.28 0.64
4 * -7.258 0.23 1.6347 24 0.70
5 * -8.831 0.38 0.81
6 * -3.015 0.60 1.5447 56 1.14
7 * -0.788 0.32 1.29
8 * -20.000 0.35 1.5447 56 1.94
9 * 1.058 0.75 2.38
10 ∞ 0.15 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.14348E + 00 K = 0.12662E + 01
A4 = -0.32717E-02 A4 = -0.26222E-02
A6 = 0.29191E-01 A6 = 0.95001E-01
A8 = -0.13327E + 00 A8 = -0.35151E-01
A10 = -0.35761E-01 A10 = -0.59584E-01
A12 = -0.17836E + 00 A12 = 0.70789E-01
A14 = -0.23606E-01

3rd surface 7th surface
K = -0.57384E + 01 K = -0.33367E + 01
A4 = -0.23392E-01 A4 = -0.20870E + 00
A6 = -0.448463E-01 A6 = 0.26111E + 00
A8 = -0.50428E-01 A8 = -0.12434E + 00
A10 = -0.32318E + 00 A10 = 0.26306E-01
A12 = -0.41912E + 00 A12 = 0.79188E-02
A14 = -0.44961E-02

4th side 8th side
K = 0.49474E + 02 K = 0.10000E + 02
A4 = -0.18580E + 00 A4 = -0.95526E-02
A6 = -0.53863E-02 A6 = -0.14596E-01
A8 = 0.75224E-02 A8 = 0.28209E-02
A10 = 0.122428E + 00 A10 = 0.38867E-03
A12 = 0.18933E + 00 A12 = -0.32980E-04
A14 = -0.32429E + 00 A14 = -0.87067E-05

5th surface 9th surface
K = 0.45142E + 02 K = -0.69072E + 01
A4 = -0.94858E-01 A4 = -0.56709E-01
A6 = 0.79143E-01 A6 = 0.23824E-01
A8 = -0.42475E-01 A8 = -0.98111E-02
A10 = 0.20169E + 00 A10 = 0.24867E-02
A12 = 0.40499E-01 A12 = -0.34367E-03
A14 = 0.91278E-01 A14 = 0.19116E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.96
2 4 -67.98
3 6 1.79
4 8 -1.83

  FIG. 13 is a sectional view of the lens of Example 5. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 14 is an aberration diagram of Example 5 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 6)
Table 6 shows lens data of the imaging lens of Example 6.

[Table 6]
Example 6

f = 2.85mm fB = 0.13mm F = 2.4 2ω = 90 ° 2Y = 5.8mm
ENTP = 0mm EXTP = -2.44mm H1 = -0.31mm H2 = -2.72mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.06 0.59
2 * 1.503 0.37 1.5447 56 0.61
3 * 5.047 0.33 0.68
4 * -6.323 0.27 1.6347 24 0.76
5 * -12.402 0.39 0.88
6 * -3.337 0.60 1.5447 56 1.19
7 * -0.850 0.37 1.34
8 * -20.000 0.35 1.5447 56 1.97
9 * 1.118 0.78 2.41
10 ∞ 0.15 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = -0.15370E-01 K = 0.85181E + 00
A4 = -0.11492E-01 A4 = 0.54124E-03
A6 = 0.21397E-01 A6 = 0.95316E-01
A8 = -0.12059E + 00 A8 = -0.38017E-01
A10 = 0.60804E-01 A10 = -0.62814E-01
A12 = -0.17836E + 00 A12 = 0.70374E-01
A14 = -0.21335E-01

3rd surface 7th surface
K = -0.14652E + 02 K = -0.34764E + 01
A4 = -0.31025E-01 A4 = -0.18949E + 00
A6 = -0.55233E-01 A6 = 0.25167E + 00
A8 = -0.41642E-02 A8 = -0.12854E + 00
A10 = -0.17304E + 00 A10 = 0.26181E-01
A12 = -0.81275E-01 A12 = 0.85962E-02
A14 = -0.41463E-02

4th side 8th side
K = 0.11379E + 02 K = 0.61855E + 00
A4 = -0.16313E + 00 A4 = -0.92964E-02
A6 = 0.24857E-01 A6 = -0.14938E-01
A8 = 0.16295E-01 A8 = 0.26285E-02
A10 = 0.10170E + 00 A10 = 0.39591E-03
A12 = 0.17228E + 00 A12 = -0.17987E-04
A14 = -0.20959E + 00 A14 = -0.10182E-04

5th side 9th side
K = 0.30621E + 02 K = -0.65136E + 01
A4 = -0.72777E-01 A4 = -0.54395E-01
A6 = 0.81336E-01 A6 = 0.23402E-01
A8 = -0.59775E-01 A8 = -0.98289E-02
A10 = 0.16537E + 00 A10 = 0.24915E-02
A12 = -0.18433E-01 A12 = -0.34215E-03
A14 = 0.33570E-02 A14 = 0.18859E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.79
2 4 -20.68
3 6 1.93
4 8 -1.93

  FIG. 15 is a sectional view of the lens of Example 6. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 16 is an aberration diagram of Example 6 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 7)
Table 7 shows lens data of the imaging lens of Example 7.

[Table 7]
Example 7

f = 3.86mm fB = 0.10mm F = 2.4 2ω = 76 ° 2Y = 6.2mm
ENTP = 0 mm EXTP = -3.48 mm H1 = -0.29 mm H2 = -3.76 mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.10 0.80
2 * 1.599 0.57 1.5447 56 0.86
3 * 9.283 0.45 0.92
4 * -1.766 0.23 1.6347 24 0.94
5 * -2.550 0.48 0.97
6 * -2.240 0.65 1.5447 56 1.17
7 * -0.751 0.05 1.39
8 * -72.997 0.50 1.5624 44 1.87
9 * 1.035 1.38 2.20
10 ∞ 0.30 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = -0.59949E-01 K = 0.62633E + 00
A4 = -0.10243E-01 A4 = -0.38756E-01
A6 = 0.17847E-01 A6 = 0.14479E + 00
A8 = -0.16046E + 00 A8 = -0.52039E-01
A10 = 0.24073E + 00 A10 = -0.97251E-01
A12 = -0.20531E + 00 A12 = 0.10059E + 00
A14 = -0.28105E-01

3rd surface 7th surface
K = -0.24893E + 02 K = -0.40221E + 01
A4 = -0.47590E-01 A4 = -0.21770E + 00
A6 = -0.10240E + 00 A6 = 0.28255E + 00
A8 = 0.41818E-01 A8 = -0.16584E + 00
A10 = -0.12889E + 00 A10 = 0.32402E-01
A12 = 0.65945E-01 A12 = 0.12266E-01
A14 = -0.47838E-02

4th side 8th side
K = -0.44200E + 01 K = -0.10000E + 02
A4 = -0.14767E + 00 A4 = 0.17542E-02
A6 = 0.68624E-01 A6 = -0.15572E-01
A8 = -0.33964E-01 A8 = 0.38795E-02
A10 = 0.45578E-01 A10 = 0.14421E-03
A12 = 0.16418E + 00 A12 = -0.86800E-04
A14 = -0.10481E + 00 A14 = 0.24730E-05

5th surface 9th surface
K = -0.40416E + 01 K = -0.96676E + 01
A4 = -0.16354E-01 A4 = -0.65060E-01
A6 = 0.13897E + 00 A6 = 0.27582E-01
A8 = -0.11442E + 00 A8 = -0.10768E-01
A10 = 0.16257E + 00 A10 = 0.25746E-02
A12 = -0.42166E-01 A12 = -0.35198E-03
A14 = 0.69704E-02 A14 = 0.20871E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.46
2 4 -10.22
3 6 1.80
4 8 -1.81

  FIG. 17 is a sectional view of the lens of Example 7. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 18 is an aberration diagram of Example 7 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 8)
Table 8 shows lens data of the imaging lens of Example 8.

[Table 8]
Example 8

f = 2.68mm fB = 0.13mm F = 2.4 2ω = 94 ° 2Y = 5.8mm
ENTP = 0mm EXTP = -2.33mm H1 = -0.23mm H2 = -2.54mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.06 0.56
2 * 1.389 0.35 1.5447 56 0.57
3 * 3.543 0.28 0.64
4 * -7.394 0.21 1.6320 23 0.70
5 * -8.481 0.40 0.80
6 * -2.968 0.61 1.5447 56 1.14
7 * -0.803 0.37 1.31
8 * -20.000 0.30 1.5447 56 1.98
9 * 1.067 0.72 2.41
10 ∞ 0.15 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.15013E + 00 K = 0.69005E + 01
A4 = -0.29642E-02 A4 = -0.88427E-02
A6 = 0.29278E-01 A6 = 0.96810E-01
A8 = -0.13014E + 00 A8 = -0.35338E-01
A10 = -0.17196E-01 A10 = -0.58921E-01
A12 = -0.17836E + 00 A12 = 0.71341E-01
A14 = -0.23925E-01

3rd surface 7th surface
K = -0.47261E + 01 K = -0.34218E + 01
A4 = -0.21699E-01 A4 = -0.21826E + 00
A6 = -0.53721E-01 A6 = 0.25966E + 00
A8 = -0.58171E-01 A8 = -0.12408E + 00
A10 = -0.32125E + 00 A10 = 0.26297E-01
A12 = -0.45663E + 00 A12 = 0.78947E-02
A14 = -0.43985E-02

4th side 8th side
K = 0.50000E + 02 K = 0.63597E + 01
A4 = -0.19716E + 00 A4 = -0.11381E-01
A6 = -0.23317E-01 A6 = -0.14739E-01
A8 = -0.76042E-02 A8 = 0.28427E-02
A10 = 0.12223E + 00 A10 = 0.37260E-03
A12 = 0.20547E + 00 A12 = -0.38292E-04
A14 = -0.32951E + 00 A14 = -0.67301E-05

5th side 9th side
K = 0.41560E + 02 K = -0.666946E + 01
A4 = -0.10204E + 00 A4 = -0.54654E-01
A6 = 0.72751E-01 A6 = 0.23162E-01
A8 = -0.40773E-01 A8 = -0.97879E-02
A10 = 0.21239E + 00 A10 = 0.24938E-02
A12 = 0.60078E-01 A12 = -0.34408E-03
A14 = 0.11905E + 00 A14 = 0.19086E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.96
2 4 -98.80
3 6 1.84
4 8 -1.85

  FIG. 19 is a sectional view of the lens of Example 8. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 20 is an aberration diagram of Example 8 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

Example 9
Table 9 shows lens data of the imaging lens of Example 9.

[Table 9]
Example 9

f = 3.74mm fB = 0.06mm F = 2.4 2ω = 76 ° 2Y = 6mm
ENTP = 0mm EXTP = -3.44mm H1 = -0.27mm H2 = -3.69mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.13 0.78
2 * 1.586 0.53 1.5447 56 0.80
3 * 5.603 0.39 0.86
4 * -8.648 0.23 1.6347 24 0.89
5 * 76.652 0.53 0.97
6 * -2.609 0.72 1.5447 56 1.20
7 * -0.712 0.05 1.44
8 * -400.000 0.46 1.5447 56 1.91
9 * 0.886 1.37 2.21
10 ∞ 0.30 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.11572E-01 K = 0.10455E + 01
A4 = -0.13767E-01 A4 = -0.20266E-01
A6 = 0.33973E-01 A6 = 0.11402E + 00
A8 = -0.15110E + 00 A8 = -0.48914E-01
A10 = 0.19686E + 00 A10 = -0.86805E-01
A12 = -0.14520E + 00 A12 = 0.99168E-01
A14 = -0.29336E-01

3rd surface 7th surface
K = -0.11408E + 02 K = -0.41959E + 01
A4 = -0.35541E-01 A4 = -0.21310E + 00
A6 = -0.83653E-01 A6 = 0.27535E + 00
A8 = 0.41062E-01 A8 = -0.16926E + 00
A10 = -0.74162E-01 A10 = 0.34574E-01
A12 = 0.58004E-02 A12 = 0.13338E-01
A14 = -0.51640E-02

4th side 8th side
K = -0.82900E + 01 K = -0.10000E + 02
A4 = -0.15536E + 00 A4 = -0.70033E-02
A6 = 0.22389E-02 A6 = -0.18607E-01
A8 = -0.64413E-01 A8 = 0.33867E-02
A10 = 0.60276E-01 A10 = 0.602127E-03
A12 = 0.25267E + 00 A12 = -0.14689E-04
A14 = -0.19672E + 00 A14 = -0.22929E-04

5th side 9th side
K = 0.50000E + 02 K = -0.83848E + 01
A4 = -0.69429E-01 A4 = -0.69588E-01
A6 = 0.60864E-01 A6 = 0.28184E-01
A8 = -0.94340E-01 A8 = -0.12047E-01
A10 = 0.18969E + 00 A10 = 0.31635E-02
A12 = -0.49295E-01 A12 = -0.48154E-03
A14 = -0.52681E-02 A14 = 0.31990E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.88
2 4 -12.23
3 6 1.58
4 8 -1.62

  FIG. 21 is a sectional view of the lens of Example 9. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 22 is an aberration diagram of Example 9 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. Two lenses L1 are disposed on the object side.

(Example 10)
Table 10 shows lens data of the imaging lens of Example 10.

[Table 10]
Example 10

f = 3.74mm fB = 0.07mm F = 2.4 2ω = 76 ° 2Y = 6mm
ENTP = 0.47mm EXTP = -3.09mm H1 = -0.23mm H2 = -3.68mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.592 0.55 1.5447 56 0.90
2 * 7.300 0.05 0.75
3 (Aperture) ∞ 0.44 0.71
4 * -2.394 0.23 1.6347 24 0.80
5 * -4.034 0.47 0.92
6 * -2.672 0.68 1.5447 56 1.19
7 * -0.802 0.08 1.43
8 * -399.112 0.54 1.5447 56 2.07
9 * 1.038 1.25 2.35
10 ∞ 0.30 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

1st side 6th side
K = -0.16546E-01 K = 0.11024E + 01
A4 = -0.10768E-01 A4 = -0.26205E-01
A6 = 0.14588E-01 A6 = 0.98230E-01
A8 = -0.12101E + 00 A8 = -0.38766E-01
A10 = 0.16782E + 00 A10 = -0.67015E-01
A12 = -0.14822E + 00 A12 = 0.66590E-01
A14 = -0.17424E-01

2nd surface 7th surface
K = -0.27699E + 02 K = -0.40898E + 01
A4 = -0.38562E-01 A4 = -0.19048E + 00
A6 = -0.76661E-01 A6 = 0.23934E + 00
A8 = 0.20031E-01 A8 = -0.13091E + 00
A10 = -0.10134E + 00 A10 = 0.22294E-01
A12 = 0.42691E-01 A12 = 0.86886E-02
A14 = -0.29554E-02

4th side 8th side
K = -0.15830E + 01 K = 0.10000E + 02
A4 = -0.15893E + 00 A4 = -0.97367E-03
A6 = 0.24116E-01 A6 = -0.11842E-01
A8 = -0.11529E-01 A8 = 0.33098E-02
A10 = 0.55473E-01 A10 = 0.31862E-04
A12 = 0.20643E + 00 A12 = -0.81974E-04
A14 = -0.15777E + 00 A14 = 0.66559E-05

5th side 9th side
K = 0.27793E + 01 K = -0.82674E + 01
A4 = -0.56831E-01 A4 = -0.59184E-01
A6 = 0.72718E-01 A6 = 0.23979E-01
A8 = -0.45919E-01 A8 = -0.93016E-02
A10 = 0.14639E + 00 A10 = 0.21940E-02
A12 = -0.44515E-01 A12 = -0.29518E-03
A14 = 0.59961E-02 A14 = 0.17032E-04

Single lens data

Lens Start surface Focal length (mm)
1 1 3.62
2 4 -9.81
3 6 1.87
4 8 -1.90

  FIG. 23 is a sectional view of the lens of Example 10. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 24 is an aberration diagram of Example 10 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. It is disposed between the first lens L1 and the second lens L2.

(Example 11)
Table 11 shows lens data of the imaging lens of Example 11.

[Table 11]
Example 11

f = 3.56mm fB = 0.09mm F = 2.4 2ω = 78 ° 2Y = 6mm
ENTP = 0mm EXTP = -3.26mm H1 = -0.22mm H2 = -3.46mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.06 0.75
2 * 1.984 0.55 1.5447 56 0.77
3 * 14.154 0.51 0.87
4 * -6.863 0.23 1.6347 24 0.97
5 * -21.750 0.48 1.07
6 * -2.781 0.66 1.5447 56 1.24
7 * -0.813 0.22 1.40
8 * -935.549 0.45 1.5862 37 1.99
9 * 1.120 1.12 2.37
10 ∞ 0.30 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = -0.29133E + 00 K = 0.13176E + 01
A4 = -0.17626E-01 A4 = -0.19538E-01
A6 = 0.33279E-02 A6 = 0.89230E-01
A8 = -0.12130E + 00 A8 = -0.39503E-01
A10 = 0.17526E + 00 A10 = -0.60784E-01
A12 = -0.12342E + 00 A12 = 0.72694E-01
A14 = -0.21504E-01

3rd surface 7th surface
K = -0.17249E + 02 K = -0.37241E + 01
A4 = -0.57123E-01 A4 = -0.19999E + 00
A6 = -0.62571E-01 A6 = 0.23588E + 00
A8 = 0.57193E-01 A8 = -0.13508E + 00
A10 = -0.50699E-01 A10 = 0.27305E-01
A12 = -0.17113E-01 A12 = 0.97445E-02
A14 = -0.35590E-02

4th side 8th side
K = 0.84903E + 01 K = -0.24888E + 01
A4 = -0.16379E + 00 A4 = -0.38904E-02
A6 = 0.33401E-01 A6 = -0.10810E-01
A8 = -0.22027E-01 A8 = 0.17636E-02
A10 = 0.50100E-01 A10 = 0.19910E-03
A12 = 0.16089E + 00 A12 = -0.12422E-04
A14 = -0.14706E + 00 A14 = -0.42476E-05

5th side 9th side
K = -0.40819E + 02 K = -0.81146E + 01
A4 = -0.99704E-01 A4 = -0.44956E-01
A6 = 0.53055E-01 A6 = 0.16051E-01
A8 = -0.80428E-01 A8 = -0.60616E-02
A10 = 0.14804E + 00 A10 = 0.13601E-02
A12 = -0.34123E-01 A12 = -0.16726E-03
A14 = -0.19387E-01 A14 = 0.85109E-05

Single lens data

Lens Start surface Focal length (mm)
1 2 4.17
2 4 -15.89
3 6 1.89
4 8 -1.91

  FIG. 25 is a sectional view of the lens of Example 11. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 26 is an aberration diagram of Example 11 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 12)
Table 12 shows lens data of the imaging lens of Example 12.

[Table 12]
Example 12

f = 3.20mm fB = 0.12mm F = 2.2 2ω = 84 ° 2Y = 5.8mm
ENTP = 0mm EXTP = -2.77mm H1 = -0.35mm H2 = -3.09mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.13 0.73
2 * 1.394 0.47 1.5891 61 0.76
3 * 3.257 0.36 0.78
4 * -5.648 0.21 1.6347 24 0.77
5 * -11.656 0.44 0.85
6 * -2.552 0.60 1.5447 56 1.25
7 * -0.784 0.20 1.37
8 * -17.876 0.45 1.5447 56 1.95
9 * 1.117 1.02 2.32
10 ∞ 0.15 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.15513E + 00 K = 0.11210E + 01
A4 = -0.40487E-02 A4 = -0.77046E-02
A6 = 0.25119E-01 A6 = 0.11237E + 00
A8 = -0.73266E-01 A8 = -0.41853E-01
A10 = 0.14276E + 00 A10 = -0.64116E-01
A12 = -0.22744E + 00 A12 = 0.72032E-01
A14 = -0.19788E-01

3rd surface 7th surface
K = -0.10238E + 01 K = -0.34411E + 01
A4 = -0.15494E-01 A4 = -0.21255E + 00
A6 = -0.87481E-01 A6 = 0.24550E + 00
A8 = 0.11841E-01 A8 = -0.12552E + 00
A10 = -0.14371E + 00 A10 = 0.27726E-01
A12 = -0.23837E + 00 A12 = 0.87314E-02
A14 = -0.41362E-02

4th side 8th side
K = 0.44402E + 02 K = 0.14629E + 01
A4 = -0.17265E + 00 A4 = -0.88500E-02
A6 = -0.90660E-01 A6 = -0.11185E-01
A8 = -0.99547E-01 A8 = 0.27765E-02
A10 = 0.39095E-01 A10 = 0.24707E-03
A12 = 0.22236E + 00 A12 = -0.54203E-04
A14 = -0.23186E-01 A14 = -0.32121E-05

5th side 9th side
K = 0.49987E + 02 K = -0.85978E + 01
A4 = -0.88605E-01 A4 = -0.62564E-01
A6 = 0.28372E-01 A6 = 0.25896E-01
A8 = -0.88042E-01 A8 = -0.10176E-01
A10 = 0.18618E + 00 A10 = 0.24708E-02
A12 = 0.42285E-01 A12 = -0.34085E-03
A14 = 0.59687E-01 A14 = 0.19746E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 3.78
2 4 -17.50
3 6 1.85
4 8 -1.91

  FIG. 27 is a sectional view of the lens of Example 12. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 28 is an aberration diagram of Example 12 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 13)
Table 13 shows lens data of the imaging lens of Example 13.

[Table 13]
Example 13

f = 3.75mm fB = 0.09mm F = 2.4 2ω = 76 ° 2Y = 6mm
ENTP = 0mm EXTP = -2.73mm H1 = -1.25mm H2 = -3.66mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.22 0.78
2 * 1.285 0.60 1.4970 82 0.78
3 * 4.162 0.35 0.74
4 * -6.008 0.23 1.6347 24 0.78
5 * -16.637 0.51 0.88
6 * -3.040 0.79 1.5447 56 1.14
7 * -0.888 0.25 1.46
8 * -4.599 0.41 1.5447 56 2.03
9 * 1.237 0.92 2.38
10 ∞ 0.25 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.29484E-01 K = -0.778103E + 00
A4 = 0.91431E-02 A4 = -0.12222E-01
A6 = 0.49269E-01 A6 = 0.21749E-01
A8 = -0.66730E-01 A8 = -0.11855E-01
A10 = 0.78168E-01 A10 = -0.42380E-01
A12 = 0.32799E-01 A12 = 0.33038E-01
A14 = -0.63781E-02

3rd surface 7th surface
K = 0.15331E + 02 K = -0.40121E + 01
A4 = 0.72053E-02 A4 = -0.17664E + 00
A6 = -0.26130E-01 A6 = 0.18299E + 00
A8 = 0.16847E + 00 A8 = -0.10012E + 00
A10 = -0.33593E + 00 A10 = 0.24353E-01
A12 = 0.38601E + 00 A12 = 0.31056E-02
A14 = -0.19064E-02

4th side 8th side
K = 0.49993E + 02 K = -0.10000E + 02
A4 = -0.39726E-02 A4 = -0.70466E-01
A6 = -0.29688E-01 A6 = 0.28758E-01
A8 = 0.17329E-01 A8 = -0.30190E-02
A10 = 0.68944E-01 A10 = -0.12482E-03
A12 = 0.60907E-01 A12 = 0.17603E-04
A14 = 0.12433E-05

5th side 9th side
K = 0.00000E + 00 K = -0.10000E + 02
A4 = 0.56402E-01 A4 = -0.75423E-01
A6 = -0.778150E-01 A6 = 0.25067E-01
A8 = 0.12778E + 00 A8 = -0.59760E-02
A10 = -0.58150E-01 A10 = 0.75217E-03
A12 = 0.63053E-01 A12 = -0.43817E-04
A14 = 0.57626E-06

Single lens data

Lens Start surface Focal length (mm)
1 2 3.50
2 4 -14.94
3 6 2.04
4 8 -1.75

  FIG. 29 is a sectional view of the lens of Example 13. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 30 is an aberration diagram of Example 13 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. It is arranged on the object side of one lens L1.

(Example 14)
Table 14 shows lens data of the imaging lens of Example 14.

[Table 14]
Example 14

f = 3.76mm fB = 0.40mm F = 2.4 2ω = 76 ° 2Y = 6mm
ENTP = 0.55mm EXTP = -2.58mm H1 = -0.44mm H2 = -3.37mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 * 1.416 0.56 1.5690 71 0.80
2 * 3.925 0.10 0.70
3 (Aperture) ∞ 0.23 0.68
4 * -6.461 0.20 1.6347 24 0.74
5 * -44.230 0.57 0.84
6 * -2.774 0.76 1.5447 56 1.12
7 * -0.892 0.21 1.39
8 * -2000.0 0.39 1.5447 56 2.05
9 * 1.150 0.84 2.30
10 ∞ 0.25 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

1st side 6th side
K = -0.25566E-01 K = 0.10364E + 01
A4 = 0.56675E-02 A4 = -0.14432E-01
A6 = 0.38771E-01 A6 = -0.73508E-02
A8 = -0.669636E-01 A8 = 0.19913E-01
A10 = 0.70836E-01 A10 = -0.37585E-01
A12 = -0.39800E-01 A12 = 0.22811E-01
A14 = -0.50129E-02

2nd surface 7th surface
K = 0.37310E + 01 K = -0.40340E + 01
A4 = -0.92571E-02 A4 = -0.19058E + 00
A6 = -0.98911E-01 A6 = 0.16226E + 00
A8 = 0.15909E + 00 A8 = -0.10287E + 00
A10 = -0.31790E + 00 A10 = 0.31654E-01
A12 = 0.13744E + 00 A12 = 0.56232E-02
A14 = -0.35184E-02

4th side 8th side
K = 0.50000E + 02 K = -0.10000E + 02
A4 = -0.61005E-01 A4 = -0.10178E + 00
A6 = -0.47523E-01 A6 = 0.31961E-01
A8 = -0.51814E-01 A8 = -0.23137E-02
A10 = 0.20797E-01 A10 = -0.18122E-03
A12 = 0.12939E + 00 A12 = -0.49515E-05
A14 = 0.43005E-05

5th side 9th side
K = 0.00000E + 00 K = -0.86941E + 01
A4 = 0.69414E-02 A4 = -0.81876E-01
A6 = -0.20410E-01 A6 = 0.24872E-01
A8 = 0.86559E-01 A8 = -0.59560E-02
A10 = -0.11271E + 00 A10 = 0.80272E-03
A12 = 0.17893E + 00 A12 = -0.54814E-04
A14 = 0.18445E-05

Single lens data

Lens Start surface Focal length (mm)
1 1 3.60
2 4 -11.94
3 6 2.11
4 8 -2.11

  FIG. 31 is a sectional view of the lens of Example 14. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 32 is an aberration diagram of Example 14 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. It is disposed between the first lens L1 and the second lens L2.

(Example 15)
Table 15 shows lens data of the imaging lens of Example 15.

[Table 15]
Example 15

f = 3.51mm fB = 0.10mm F = 2.4 2ω = 80 ° 2Y = 6mm
ENTP = 0mm EXTP = -3.07mm H1 = -0.37mm H2 = -3.40mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.14 0.73
2 * 1.415 0.41 1.5891 61 0.73
3 * 3.135 0.34 0.76
4 * -6.913 0.42 1.6347 24 0.78
5 * 74.053 0.43 0.94
6 * ∞ 0.69 1.5447 56 1.33
7 * -0.801 0.13 1.48
8 * -4.273 0.30 1.5447 56 1.82
9 * 1.025 1.33 2.13
10 ∞ 0.15 1.5163 64 3.00
11 ∞ 3.00

Aspheric coefficient

2nd side 6th side
K = 0.12315E + 00 K = 0.50,000E + 02
A4 = -0.42607E-02 A4 = -0.87796E-01
A6 = 0.11361E-01 A6 = 0.97312E-01
A8 = -0.82737E-01 A8 = -0.43882E-01
A10 = 0.17610E + 00 A10 = -0.64485E-01
A12 = -0.22614E + 00 A12 = 0.72205E-01
A14 = -0.18910E-01

3rd surface 7th surface
K = -0.39391E + 01 K = -0.46801E + 01
A4 = -0.24045E-01 A4 = -0.15446E + 00
A6 = -0.74788E-01 A6 = 0.22907E + 00
A8 = -0.79797E-02 A8 = -0.13398E + 00
A10 = -0.95377E-01 A10 = 0.25603E-01
A12 = -0.97403E-01 A12 = 0.88683E-02
A14 = -0.33587E-02

4th side 8th side
K = 0.49142E + 02 K = -0.38751E + 01
A4 = -0.17968E + 00 A4 = 0.50682E-02
A6 = -0.36950E-01 A6 = -0.61988E-02
A8 = -0.83918E-01 A8 = 0.28707E-02
A10 = 0.27813E-01 A10 = 0.10703E-03
A12 = 0.22963E + 00 A12 = -0.98210E-04
A14 = -0.11819E + 00 A14 = 0.19974E-05

5th side 9th side
K = -0.50000E + 02 K = -0.98427E + 01
A4 = -0.13592E + 00 A4 = -0.63450E-01
A6 = 0.73084E-01 A6 = 0.28736E-01
A8 = -0.98764E-01 A8 = -0.10575E-01
A10 = 0.13711E + 00 A10 = 0.24563E-02
A12 = -0.13061E-01 A12 = -0.33013E-03
A14 = 0.41119E-01 A14 = 0.20407E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 4.02
2 4 -9.94
3 6 1.47
4 8 -1.49

  FIG. 33 is a sectional view of the lens of Example 15. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 34 is an aberration diagram of Example 15 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 16)
Table 16 shows lens data of the imaging lens of Example 16.

[Table 16]
Example 16

f = 2.39mm fB = 0.10mm F = 2.4 2ω = 88 ° 2Y = 4.8mm
ENTP = 0mm EXTP = -1.85mm H1 = -0.55mm H2 = -2.29mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.06 0.50
2 * 1.046 0.32 1.5447 56 0.53
3 * 2.999 0.26 0.56
4 * -3.404 0.15 1.6347 24 0.57
5 * -8.253 0.32 0.66
6 * -2.757 0.53 1.5447 56 1.04
7 * -0.773 0.41 1.15
8 * -6.706 0.35 1.5447 56 1.67
9 * 1.111 0.50 2.02
10 ∞ 0.11 1.5163 64 2.50
11 ∞ 2.50

Aspheric coefficient

2nd side 6th side
K = 0.19441E + 00 K = -0.66604E + 01
A4 = 0.29866E-02 A4 = 0.22176E-01
A6 = 0.74244E-01 A6 = 0.17005E + 00
A8 = -0.23775E + 00 A8 = -0.10632E + 00
A10 = 0.19427E-01 A10 = -0.18216E + 00
A12 = -0.23132E + 01 A12 = 0.32064E + 00
A14 = -0.13576E + 00

3rd surface 7th surface
K = -0.39652E + 01 K = -0.36659E + 01
A4 = -0.43167E-01 A4 = -0.33422E + 00
A6 = -0.27024E + 00 A6 = 0.52592E + 00
A8 = -0.15200E + 00 A8 = -0.28727E + 00
A10 = -0.12380E + 01 A10 = 0.92534E-01
A12 = -0.668070E + 01 A12 = 0.26576E-01
A14 = -0.27325E-01

4th side 8th side
K = 0.26847E + 02 K = 0.26083E + 01
A4 = -0.38433E + 00 A4 = -0.33465E-01
A6 = -0.26864E + 00 A6 = -0.19756E-01
A8 = -0.68342E-01 A8 = 0.91832E-02
A10 = 0.10333E + 01 A10 = 0.15174E-02
A12 = 0.14198E + 01 A12 = -0.31982E-03
A14 = -0.18528E + 01 A14 = -0.70457E-04

5th side 9th side
K = 0.30,000E + 02 K = -0.71739E + 01
A4 = -0.16952E + 00 A4 = -0.89354E-01
A6 = 0.11937E + 00 A6 = 0.50592E-01
A8 = 0.29565E-01 A8 = -0.25723E-01
A10 = 0.11424E + 01 A10 = 0.78591E-02
A12 = 0.13544E + 01 A12 = -0.14929E-02
A14 = 0.90897E + 00 A14 = 0.12763E-03

Single lens data

Lens Start surface Focal length (mm)
1 2 2.79
2 4 -9.24
3 6 1.80
4 8 -1.72

  FIG. 35 is a sectional view of the lens of Example 16. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 36 is an aberration diagram of Example 16 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 17)
Table 17 shows lens data of the imaging lens of Example 17.

[Table 17]
Example 17

f = 2.55mm fB = 0.12mm F = 2.4 2ω = 84 ° 2Y = 4.8mm
ENTP = 0mm EXTP = -1.79mm H1 = 0.86mm H2 = -2.43mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.10 0.53
2 * 0.988 0.36 1.5250 70 0.56
3 * 2.827 0.28 0.57
4 * -3.159 0.15 1.6347 24 0.59
5 * -6.326 0.36 0.65
6 * -2.956 0.44 1.5447 56 1.06
7 * -0.872 0.42 1.19
8 * -4.093 0.35 1.5447 56 1.59
9 * 1.355 0.47 1.92
10 ∞ 0.11 1.5163 64 2.50
11 ∞ 2.50

Aspheric coefficient

2nd side 6th side
K = 0.20249E + 00 K = -0.15691E + 02
A4 = 0.55519E-02 A4 = 0.12215E-01
A6 = 0.51176E-01 A6 = 0.13733E + 00
A8 = -0.26477E + 00 A8 = -0.15990E + 00
A10 = 0.71746E + 00 A10 = -0.22397E + 00
A12 = -0.12118E + 01 A12 = 0.48009E + 00
A14 = -0.20752E + 00

3rd surface 7th surface
K = -0.20389E + 01 K = -0.39995E + 01
A4 = -0.25313E-01 A4 = -0.23949E + 00
A6 = -0.94856E-01 A6 = 0.55907E + 00
A8 = -0.52310E + 00 A8 = -0.39794E + 00
A10 = -0.21449E + 00 A10 = 0.10321E + 00
A12 = -0.15706E + 01 A12 = 0.38631E-01
A14 = -0.24691E-01

4th side 8th side
K = 0.24387E + 02 K = 0.28499E + 01
A4 = -0.34329E + 00 A4 = -0.50638E-01
A6 = -0.44254E + 00 A6 = -0.54852E-02
A8 = 0.38295E + 00 A8 = 0.12196E-01
A10 = 0.25698E + 01 A10 = 0.10337E-02
A12 = 0.54055E + 01 A12 = -0.68985E-03
A14 = -0.27209E + 01 A14 = -0.45429E-04

5th side 9th side
K = 0.30000E + 02 K = -0.887363E + 01
A4 = -0.18885E + 00 A4 = -0.10697E + 00
A6 = -0.20656E-01 A6 = 0.58263E-01
A8 = 0.29769E-01 A8 = -0.29896E-01
A10 = 0.22362E + 01 A10 = 0.98114E-02
A12 = 0.20177E + 01 A12 = -0.22220E-02
A14 = 0.30519E + 00 A14 = 0.33332E-03

Single lens data

Lens Start surface Focal length (mm)
1 2 2.71
2 4 -10.13
3 6 2.11
4 8 -1.83

  FIG. 37 is a sectional view of the lens of Example 17. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 38 is an aberration diagram of Example 17 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 18)
Table 18 shows lens data of the imaging lens of Example 18.

[Table 18]
Example 18

f = 2.55mm fB = 0.12mm F = 2.4 2ω = 84 ° 2Y = 4.8mm
ENTP = 0mm EXTP = -1.81mm H1 = -0.83mm H2 = -2.43mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.08 0.53
2 * 1.005 0.33 1.5447 56 0.57
3 * 2.934 0.25 0.59
4 * -3.272 0.16 1.6347 24 0.59
5 * -7.434 0.38 0.65
6 * -2.604 0.44 1.5447 56 1.04
7 * -0.838 0.41 1.15
8 * -5.169 0.35 1.5447 56 1.57
9 * 1.240 0.49 1.91
10 ∞ 0.11 1.5163 64 2.50
11 ∞ 2.50

Aspheric coefficient

2nd side 6th side
K = 0.17574E + 00 K = -0.11074E + 02
A4 = 0.14632E-01 A4 = 0.19975E-01
A6 = -0.89682E-01 A6 = 0.15534E + 00
A8 = 0.27596E-01 A8 = -0.15587E + 00
A10 = 0.11537E + 01 A10 = -0.23078E + 00
A12 = -0.58377E + 01 A12 = 0.47334E + 00
A14 = -0.20299E + 00

3rd surface 7th surface
K = -0.65697E + 01 K = -0.39350E + 01
A4 = -0.50725E-01 A4 = -0.26389E + 00
A6 = -0.22999E + 00 A6 = 0.57349E + 00
A8 = -0.71452E + 00 A8 = -0.39045E + 00
A10 = -0.10521E + 01 A10 = 0.10513E + 00
A12 = -0.28908E + 01 A12 = 0.38586E-01
A14 = -0.26867E-01

4th side 8th side
K = 0.22148E + 02 K = 0.51930E + 01
A4 = -0.31115E + 00 A4 = -0.59058E-01
A6 = -0.49357E + 00 A6 = -0.10395E-01
A8 = 0.92771E-01 A8 = 0.12891E-01
A10 = 0.17284E + 01 A10 = 0.15369E-02
A12 = 0.46089E + 01 A12 = -0.52781E-03
A14 = -0.27209E + 01 A14 = -0.12570E-03

5th side 9th side
K = -0.30000E + 02 K = -0.80616E + 01
A4 = -0.12274E + 00 A4 = -0.10774E + 00
A6 = 0.17239E-01 A6 = 0.58656E-01
A8 = -0.17457E-01 A8 = -0.30491E-01
A10 = 0.22454E + 01 A10 = 0.98738E-02
A12 = 0.23445E + 01 A12 = -0.21573E-02
A14 = 0.11152E-01 A14 = 0.22162E-03

Single lens data

Lens Start surface Focal length (mm)
1 2 2.65
2 4 -9.35
3 6 2.08
4 8 -1.80

  FIG. 39 is a sectional view of the lens of Example 18. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. 40 is an aberration diagram of Example 18 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 19)
Table 19 shows lens data of the imaging lens of Example 19.

[Table 19]
Example 19

f = 2.78mm fB = 0.11mm F = 2.4 2ω = 80 ° 2Y = 4.8mm
ENTP = 0mm EXTP = -2.28mm H1 = -0.45mm H2 = -2.67mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.03 0.62
2 * 1.386 0.57 1.5447 56 0.64
3 * ∞ 0.12 0.72
4 * -5.516 0.26 1.6347 24 0.73
5 * 14.322 0.49 0.78
6 * -2.835 0.43 1.5447 56 0.90
7 * -0.778 0.07 1.04
8 * -500.000 0.54 1.5447 56 1.56
9 * 0.974 0.68 1.97
10 ∞ 0.30 1.5163 64 2.50
11 ∞ 2.50

Aspheric coefficient

2nd side 6th side
K = -0.39397E + 00 K = 0.38522E + 01
A4 = -0.13313E-01 A4 = -0.36491E-01
A6 = 0.40182E-01 A6 = -0.17691E-01
A8 = -0.42969E + 00 A8 = -0.25460E-01
A10 = 0.59331E + 00 A10 = -0.11116E + 00
A12 = -0.96894E + 00 A12 = 0.19761E + 00
A14 = -0.19146E + 00

3rd surface 7th surface
K = -0.50000E + 02 K = -0.40883E + 01
A4 = -0.22080E + 00 A4 = -0.31162E + 00
A6 = -0.36881E + 00 A6 = 0.43524E + 00
A8 = 0.73250E + 00 A8 = -0.43275E + 00
A10 = -0.19244E + 01 A10 = 0.18884E + 00
A12 = 0.20186E + 01 A12 = 0.49393E-01
A14 = -0.38984E-01

4th side 8th side
K = 0.47376E + 02 K = -0.17133E + 07
A4 = -0.22239E + 00 A4 = -0.13177E + 00
A6 = 0.22316E-01 A6 = 0.62728E-01
A8 = 0.10800E + 00 A8 = -0.49037E-02
A10 = 0.63320E-01 A10 = -0.87303E-03
A12 = 0.10497E + 01 A12 = -0.52575E-03
A14 = 0.15697E-03

5th side 9th side
K = 0.00000E + 00 K = -0.71362E + 01
A4 = -0.28280E-01 A4 = -0.10981E + 00
A6 = 0.69485E-01 A6 = 0.57839E-01
A8 = 0.33803E + 00 A8 = -0.23851E-01
A10 = -0.59392E + 00 A10 = 0.57259E-02
A12 = 0.62530E + 00 A12 = -0.779339E-03
A14 = 0.48958E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 2.54
2 4 -6.24
3 6 1.83
4 8 -1.78

  FIG. 41 is a sectional view of the lens of Example 19. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. FIG. 42 is an aberration diagram of Example 19 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

(Example 20)
Table 20 shows lens data of the imaging lens of Example 20.

[Table 20]
Example 20

f = 2.77mm fB = 0.11mm F = 2.4 2ω = 72 ° 2Y = 4.8mm
ENTP = 0mm EXTP = -2.24mm H1 = -0.51mm H2 = -2.67mm

Surface number R (mm) D (mm) Nd νd Effective radius (mm)
1 (Aperture) ∞ -0.04 0.58
2 * 1.336 0.89 1.5250 70 0.58
3 * 11.976 0.25 0.71
4 * -4.794 0.22 1.6347 24 0.73
5 * -9.004 0.46 0.80
6 * -2.713 0.42 1.5447 56 0.94
7 * -0.760 0.05 1.10
8 * -833.333 0.39 1.5447 56 1.40
9 * 0.898 0.58 1.91
10 ∞ 0.15 1.5163 64 2.50
11 ∞ 2.50

Aspheric coefficient

2nd side 6th side
K = -0.26554E + 00 K = 0.28575E + 01
A4 = -0.48213E-02 A4 = -0.23466E + 00
A6 = 0.29221E-01 A6 = 0.20924E + 00
A8 = -0.33601E + 00 A8 = 0.14533E-01
A10 = 0.87231E + 00 A10 = -0.23013E + 00
A12 = -0.86333E + 00 A12 = 0.13597E + 00
A14 = -0.17583E-01

3rd surface 7th surface
K = -0.50000E + 02 K = -0.41582E + 01
A4 = -0.11095E + 00 A4 = -0.37034E + 00
A6 = -0.26247E + 00 A6 = 0.53231E + 00
A8 = 0.68642E + 00 A8 = -0.43430E + 00
A10 = -0.220472E + 01 A10 = 0.19971E + 00
A12 = 0.20935E + 01 A12 = 0.40280E-01
A14 = -0.47995E-01

4th side 8th side
K = 0.33422E + 02 K = -0.26153E + 06
A4 = -0.27513E + 00 A4 = -0.13633E + 00
A6 = 0.41033E-01 A6 = 0.19749E-01
A8 = 0.38304E-01 A8 = 0.37847E-02
A10 = -0.49873E-01 A10 = 0.40256E-02
A12 = 0.10226E + 01 A12 = -0.10035E-03
A14 = -0.57465E-03

5th side 9th side
K = 0.00000E + 00 K = -0.57240E + 01
A4 = -0.17889E + 00 A4 = -0.13143E + 00
A6 = 0.65597E-01 A6 = 0.67390E-01
A8 = 0.40672E + 00 A8 = -0.26471E-01
A10 = -0.50693E + 00 A10 = 0.63600E-02
A12 = 0.61780E + 00 A12 = -0.88042E-03
A14 = 0.46830E-04

Single lens data

Lens Start surface Focal length (mm)
1 2 2.78
2 4 -16.48
3 6 1.80
4 8 -1.65

  43 is a sectional view of the lens of Example 20. FIG. In the figure, L1 is a first lens having a positive refractive power and having a convex surface facing the object side, L2 is a second lens having a negative refractive power and having a concave surface facing the object side, and L3 has a positive refractive power. And a fourth lens having a negative refractive power and a biconcave shape, S is an aperture stop, and I is an imaging surface. Further, F is a parallel plate assuming an optical low-pass filter, an IR cut filter, a seal glass of a solid-state image sensor, or the like. 44 is an aberration diagram of Example 20 (spherical aberration (a), astigmatism (b), distortion (c), and meridional coma aberration (d)). In the present embodiment, the fourth lens L4 has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery, and the aperture stop S is the first one. One lens L1 is disposed on the object side.

  Table 21 shows values of the respective examples corresponding to the respective conditional expressions.

  Further, the present invention is not limited to the embodiments described in the specification, and it is understood that other embodiments and modifications are included in the art from the embodiments and ideas described in the present specification. It is obvious to For example, even when a dummy lens having substantially no refractive power is further provided, it is within the scope of application of the present invention.

  The present invention can provide an imaging lens suitable for a small portable terminal.

DESCRIPTION OF SYMBOLS 10 Imaging lens 50 Imaging unit 51 Imaging element 51a Photoelectric conversion part 52 Board | substrate 52a Support flat plate 52b Flexible board 53 Case 53a Flange part 54 External connection terminal 55 Diaphragm member 60 Input part 70 Touch panel 80 Wireless communication part 91 Storage part 92 Temporary storage part DESCRIPTION OF SYMBOLS 100 Smartphone 101 Control part I Imaging surface F Parallel flat plate L1-L4 Lens S Aperture stop

Claims (13)

From the object side,
A first lens having positive refractive power and having a convex surface facing the object side;
A second lens having negative refractive power and having a concave surface facing the object side;
A third lens having positive refractive power and having a convex surface facing the image side;
A fourth lens having negative refractive power and a biconcave shape,
The fourth lens has an aspheric object side surface and an image side surface, and has a shape in which the negative refractive power becomes weaker from the vicinity of the optical axis toward the periphery,
An aperture stop is disposed closer to the object side than the second lens;
An imaging lens satisfying the following conditional expression:
−10 <f1 / f4 <−0.8 (1)
−200 <f2 / f <−1.4 (2)
35 <νd4 <85 (3)
However,
f1: focal length of the first lens f4: focal length of the fourth lens f2: focal length of the second lens f: focal length νd4 of the entire imaging lens system: Abbe number of the fourth lens The imaging lens according to claim 1, wherein the following conditional expression is satisfied.
0.1 <T12 / T23 <2.5 (4)
However,
T12: Air spacing on the optical axis of the first lens and the second lens T23: Air spacing on the optical axis of the second lens and the third lens The imaging lens according to claim 1, wherein the following conditional expression is satisfied.
0.6 <f1 / f <5.0 (5)
However,
f1: Focal length of the first lens f: Focal length of the entire imaging lens system The imaging lens according to any one of claims 1 to 3, wherein the following conditional expression is satisfied.
0.3 <f3 / f <1.5 (6)
However,
f3: focal length of the third lens f: focal length of the entire imaging lens system The imaging lens according to any one of claims 1 to 4, wherein the following conditional expression is satisfied.
0.001 <T34 / f <0.3 (7)
However,
T34: Air space on the optical axis of the third lens and the fourth lens The imaging lens according to claim 1, wherein the following conditional expression is satisfied.
−1.0 <(r7 + r8) / (r7−r8) <1.0 (8)
However,
r7: radius of curvature of the object side surface of the fourth lens r8: radius of curvature of the image side surface of the fourth lens The imaging lens according to any one of claims 1 to 6, wherein the following conditional expression is satisfied.
-5.0 <P _air12 /P<-0.1 (9)
However,
P: refractive power of the entire imaging lens system (reciprocal of focal length)
P _air12 : Refractive power of a so-called air lens formed by the image side surface of the first lens and the object side surface of the second lens, which is obtained by the following conditional expression.
P _air12 = (1-N1) / R2 + (N2-1) / R3-{((1-N1) · (N2-1)) / (R2 · R3)} · D2 (10)
However,
N1: Refractive index with respect to d line of the first lens N2: Refractive index with respect to d line of the second lens R2: Radius of curvature of the image side surface of the first lens R3: Radius of curvature of the object side surface of the second lens D2: Air spacing on the optical axis of the first lens and the second lens The imaging lens according to any one of claims 1 to 7, wherein the following conditional expression is satisfied.
50 <νd1 <97 (11)
15 <νd2 <29 (12)
However,
νd1: Abbe number of the first lens νd2: Abbe number of the second lens   9. The imaging lens according to claim 1, wherein the aperture stop is disposed closer to an object side than an object side surface of the first lens.   The imaging lens according to any one of claims 1 to 8, wherein the aperture stop is disposed between the first lens and the second lens.   The imaging lens according to claim 1, comprising a lens having substantially no refractive power.   An imaging apparatus comprising: a solid-state imaging device that photoelectrically converts a subject image; and the imaging lens according to claim 1.   A portable terminal comprising the imaging device according to claim 12.