JP6752636B2 - Imaging lenses, imaging optics and digital devices - Google Patents

Description

The present invention relates to an image pickup lens, an image pickup optical device, and a digital device. For example, an image sensor (for example, a CCD (Charge Coupled Device) type image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor, etc.) can capture an image of a subject. A compact, wide-angle, large-diameter image sensor suitable for interchangeable-lens digital cameras captured by the image sensor), and an image sensor that outputs the image of the subject captured by the image sensor and the image sensor as an electrical signal. The present invention relates to a digital device with an image input function such as a digital camera equipped with the image pickup optical device.

In recent years, digital cameras have become common as interchangeable lens cameras. With digital cameras, users can view captured images at the same magnification on a monitor, so there is an increasing demand for improved MTF (Modulation Transfer Function) performance and reduction of chromatic aberration. Moreover, due to the demand for expansion of the photographing area, there is a demand for a wide-angle lens having a large aperture of F value: 2 or less while having a wide angle of view of 2ω: 65 degrees or more. In order to meet such demands, an imaging lens as an interchangeable lens for an interchangeable lens digital camera has been proposed in Patent Document 1.

Japanese Unexamined Patent Publication No. 05-034592

While the image pickup lens proposed in Patent Document 1 realizes a wide angle of view, it lacks correction of various aberrations such as distortion, and has an F value of about 2.8.

The present invention has been made in view of such a situation, and an object of the present invention is to suppress distortion while realizing a wide angle of view exceeding a total angle of view of 2ω: 65 degrees and a bright F value, and to suppress distortion in the entire image. An object of the present invention is to provide a small image pickup lens capable of obtaining uniform image quality, an image pickup optical device equipped with the same image pickup lens, and a digital device.

In order to achieve the above object, the image pickup lens of the first invention is composed of a first group and a second group having positive power in order from the object side.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
It is characterized by satisfying the following conditional equations (1) , (2), (3b) and (4) .
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
−2.09 ≦ φ14 / φ15 <−1.5… (3 b )
Nd15> 1.8 ... (4)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Is.

The imaging lens of the second invention is composed of a first group and a second group having positive power in order from the object side.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
It is characterized by satisfying the following conditional equations (1) to (3) and (4a) .
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
-3 <φ14 / φ15 <-1.5 ... (3)
Nd15 ≧ 1.88300… (4a)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Is.

The image pickup lens of the third invention is composed of a first group and a second group having positive power in order from the object side.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
It is characterized by satisfying the following conditional equations (1) to (4) and (6a) .
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
-3 <φ14 / φ15 <-1.5 ... (3)
Nd15> 1.8 ... (4)
Nd13 ≧ 1.84666… (6a)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Nd13: Refractive index with respect to the d-line of the third lens,
Is.

The imaging lens of the fourth invention is composed of a first group and a second group having positive power in order from the object side.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
It is characterized by satisfying the following conditional equations (1), (2) and (3c) .
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
−2.09 ≦ φ14 / φ15 ≦ -1.77… (3c)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Is.

Fifth imaging lens of the present invention, in the above first to fourth any one invention, wherein the lens positioned closest to the image side in the first group to have a positive power.

The imaging lens of the sixth invention is characterized in that, in any one of the first to fifth inventions, the lens located adjacent to the object side of the diaphragm satisfies the following conditional expression (5). ..
θgf- (-0.00162νd + 0.6415) <0.012 ... (5)
However,
θgf: partial dispersion ratio of lens material,
θgf = (Ng-NF) / (NF-NC)
Ng: Refractive index with respect to g-line,
NF: Refractive index for F line,
NC: Refractive index for C line,
νd: Abbe number related to d-line of lens material,
Is.

The imaging lens of the seventh aspect based on the one of the invention of the first to sixth, wherein the first group to have a positive power.

The imaging lens of the eighth invention is characterized in that, in any one of the first to seventh inventions, the second group has two or more positive lenses continuously from the object side.

In the imaging lens of the ninth invention, in any one of the first to eighth aspects, the second group has a positive lens, a positive lens, a positive lens, a negative lens, an aperture, and a negative lens in order from the object side. , A positive lens, a positive lens, and a positive lens.

The image pickup lens of the tenth invention is characterized by having three or more aspherical lenses in any one of the first to ninth inventions.

The imaging optical device of the eleventh invention includes an imaging lens according to any one of the first to tenth inventions and an imaging element that converts an optical image formed on an imaging surface into an electrical signal. It is characterized in that the image pickup lens is provided so that an optical image of a subject is formed on the image pickup surface of the image pickup element.

The digital device of the twelfth invention is characterized in that at least one of a still image shooting and a moving image shooting of a subject is added by providing the imaging optical device according to the eleventh invention.

According to the present invention, a compact image pickup lens and an image pickup optical device capable of achieving a wide angle of view exceeding a total angle of view of 2ω: 65 degrees and a bright F value while suppressing distortion and obtaining uniform image quality over the entire image. It can be realized. By using the image pickup lens or the image pickup optical device in a digital device (for example, a digital camera), it is possible to compactly add a high-performance image input function to the digital device.

The lens block diagram of the 1st Embodiment (Example 1). The lens block diagram of the 2nd Embodiment (Example 2). The lens block diagram of the 3rd Embodiment (Example 3). The lens block diagram of the 4th Embodiment (Example 4). The longitudinal aberration diagram of Example 1. The longitudinal aberration diagram of Example 2. The longitudinal aberration diagram of Example 3. The longitudinal aberration diagram of Example 4. FIG. 5 is a lateral aberration diagram at the first focus position of the first embodiment. FIG. 5 is a lateral aberration diagram at the second focus position of the first embodiment. FIG. 6 is a lateral aberration diagram at the first focus position of the second embodiment. FIG. 5 is a lateral aberration diagram at the second focus position of the second embodiment. FIG. 5 is a lateral aberration diagram at the first focus position of the third embodiment. The lateral aberration diagram at the 2nd focus position of Example 3. FIG. FIG. 6 is a lateral aberration diagram at the first focus position of the fourth embodiment. The lateral aberration diagram at the 2nd focus position of Example 4. FIG. The schematic diagram which shows the schematic configuration example of the digital device equipped with the imaging optical device.

Hereinafter, an imaging lens, an imaging optical device, and a digital device according to an embodiment of the present invention will be described. The imaging lens according to the embodiment of the present invention comprises a first group and a second group having positive power in order from the object side (power: an amount defined by the reciprocal of the focal length), and the first group is described above. In order from the object side, the group has a first lens having negative power, a second lens having negative power, a third lens having positive power, a fourth lens having negative power, and a fifth lens having positive power. Has a lens and. Then, the first lens and the second lens have a meniscus shape that is convex toward the object side, the fourth lens and the fifth lens form a junction lens, and the position of the first group is fixed. By moving the second group to the object side, focusing on a short-range object is performed.

Further, the image pickup lens is characterized in that it satisfies the following conditional equations (1) to (3).
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
-3 <φ14 / φ15 <-1.5 ... (3)
However,
φ14: Power of the 4th lens (that is, the reciprocal of the focal length f14 of the 4th lens constituting the 1st group),
φ15: Power of the 5th lens (that is, the reciprocal of the focal length f15 of the 5th lens constituting the 1st group),
φ: Power of the whole system (that is, the reciprocal of the combined focal length f of the whole system),
Is.

In the first group, by giving negative power to the first lens and the second lens in order from the object side, the respective powers can be weakened, and various aberrations typified by distortion can be reduced. Moreover, by making both the first and second lenses a meniscus shape with the convex surface facing the object side, light rays incident from a wide angle of view are gently bent to prevent curvature of field and coma. , Negative distortion generated in the first lens and the second lens can be appropriately corrected by the third lens having positive power.

By using the 4th and 5th lenses as negative and positive junction lenses and arranging the appropriate power to satisfy the conditional equations (1) to (3), the occurrence of spherical aberration and curvature of field can be reduced and the design performance can be reduced. Not only can the final product performance be improved. The resin layer having a thickness of 1 mm or less on the optical axis does not constitute the bonded lens. Therefore, a lens (for example, a composite aspherical lens) in which a resin is formed on the lens surface with a core thickness of 1 mm or less as a material for forming the lens is considered as one lens instead of a bonded lens.

The conditional expression (1) defines a preferable conditional range regarding the power of the fourth lens. If the lower limit of the conditional expression (1) is exceeded, the negative power does not become too strong, and it is possible to prevent the total length from increasing. On the other hand, when the value falls below the upper limit of the conditional expression (1), the negative power does not become too weak, and various aberrations such as curvature of field and axial chromatic aberration can be satisfactorily corrected.

The conditional expression (2) defines a preferable conditional range regarding the power of the fifth lens. If the lower limit of the conditional expression (2) is exceeded, the positive power does not become too weak and the first group can be brought closer to the afocal optical system, so that the fluctuation of aberration can be suppressed when focusing on a short-distance object. it can. In addition, it is possible to prevent the total length from increasing. On the other hand, if it falls below the upper limit of the conditional expression (2), the positive power does not become too strong, and it is possible to prevent the occurrence of various aberrations including spherical aberration.

In the conditional expression (3), the power defined by the conditional expression (1) and the conditional expression (2) is optimized by the power ratio of the fourth lens and the fifth lens in the first group. When the lower limit of the conditional expression (3) is exceeded, the power of the negative lens does not become too strong with respect to the positive lens, and it is possible to prevent the distortion aberration from becoming too large. If it is less than the upper limit of the conditional expression (3), the power of the negative lens is not too weak with respect to the positive lens, and various aberrations such as curvature of field and axial chromatic aberration can be satisfactorily corrected.

When the power arrangement of the 4th lens and the 5th lens is set so as to satisfy the conditional expressions (1) to (3), uniform image quality and bright F value are realized in the entire image while having a wide angle of view as well as improving aberration. can do. However, when each lens is eccentric, aberrations, particularly coma on the axis, become remarkable, and it may be difficult to exhibit the original performance. In order to solve this problem, a junction lens is composed of a fourth lens and a fifth lens. If the 4th and 5th lenses are bonded lenses, problems caused by the eccentricity of the lenses do not occur, so that not only the design performance but also the final product performance can be improved.

That is, according to the above characteristic configuration, a compact image pickup that suppresses various aberrations such as distortion while realizing a wide angle of view exceeding 65 degrees and a bright F value, and obtains uniform image quality over the entire image. A lens and an imaging optical device including the lens can be realized. By using the image pickup lens or image pickup optical device in a digital device (for example, a digital camera), it is possible to add a high-performance image input function to the digital device in a lightweight and compact manner, making the digital device compact and low. It can contribute to cost improvement, high performance, and high functionality. For example, since the imaging lens having the above characteristic configuration is suitable as an interchangeable lens for a digital camera or a video camera, it is possible to realize a lightweight, compact and high-performance interchangeable lens that is convenient to carry. The conditions for achieving such effects in a well-balanced manner, as well as achieving higher optical performance, lighter weight, smaller size, etc. will be described below.

Regarding the fourth lens, it is desirable to satisfy the following conditional expression (1a), and it is further desirable to satisfy the conditional expression (1b).
-0.6 <φ14 / φ <-0.3 ... (1a)
-0.55 <φ14 / φ <-0.35 ... (1b)
These conditional expressions (1a) and (1b) define a more preferable conditional range based on the above-mentioned viewpoints and the like among the conditional ranges defined by the conditional expression (1). Therefore, the above effect can be further enhanced by preferably satisfying the conditional expression (1a) and more preferably the conditional expression (1b).

Regarding the fifth lens, it is desirable to satisfy the following conditional expression (2a), and it is further desirable to satisfy the conditional expression (2b).
0.2 <φ15 / φ <0.4 ... (2a)
0.2 <φ15 / φ <0.3 ... (2b)
These conditional expressions (2a) and (2b) define a more preferable conditional range based on the above-mentioned viewpoints and the like, among the conditional ranges defined by the conditional expression (2). Therefore, the above effect can be further enhanced by preferably satisfying the conditional expression (2a) and more preferably the conditional expression (2b).

Regarding the 4th and 5th lenses, it is desirable that the following conditional expression (3a) , (3b) or (3c) is satisfied.
-3 <φ14 / φ15 <-2 ... (3a)
−2.09 ≦ φ14 / φ15 <−1.5… (3b)
−2.09 ≦ φ14 / φ15 ≦ -1.77… (3c)
These conditional expressions (3a), (3b) and (3c) are, within the conditional range of the conditional expression (3) defines, defines a further preferable condition range based on the viewpoint, etc. There is. Therefore, preferably, the above effect can be further enhanced by satisfying the conditional expression (3a) , (3b) or (3c) .

It is desirable that the bonded lens composed of the fourth and fifth lenses has a negative synthetic power. If the 4th lens with negative power and the 5th lens with positive power are used as a junction lens and the junction lens has negative power, it is possible to correct curvature of field, so that a good image can be obtained up to the periphery of the screen. it can.

With respect to the fifth lens, it is desirable that the following conditional expression (4) or (4a) is satisfied.
Nd15> 1.8 ... (4)
Nd15 ≧ 1.88300… (4a)
However,
Nd15: Refractive index of the fifth lens of the first group with respect to the d line,
Is.

When the fifth lens constituting the junction lens in the first group satisfies the conditional expression (4) or (4a) , the curvature of the lens surface can be reduced (that is, the curvature can be loosened), and spherical aberration can be achieved. Can be effectively reduced. Further, since the curvature of the joint surface can be reduced, there is an advantage that the joint becomes easy and the reliability is improved.

It is desirable that the lens located closest to the image side in the first group has a positive power. When the lens on the most image side in the first group has a positive power, the height of light incident on the second group can be reduced, so that the focus group can be miniaturized. Further, since the first group can be brought closer to the afocal optical system, the fluctuation of the aberration can be suppressed when focusing on a short-distance object.

It is desirable that the lenses located adjacent to the object side of the diaphragm satisfy the following conditional expression (5).
θgf- (-0.00162νd + 0.6415) <0.012 ... (5)
However,
θgf: partial dispersion ratio of lens material,
θgf = (Ng-NF) / (NF-NC)
Ng: Refractive index with respect to g-line,
NF: Refractive index for F line,
NC: Refractive index for C line,
νd: Abbe number related to d-line of lens material,
Is.

The conditional expression (5) defines a preferable range regarding the partial dispersion ratio of the lenses located adjacent to the object side of the diaphragm. According to this configuration, axial chromatic aberration can be reduced and color bleeding can be prevented.

The lens located adjacent to the object side of the diaphragm preferably satisfies the following conditional expression (5a), and more preferably satisfies the conditional expression (5b).
θgf- (-0.00162νd + 0.6415) <0.006 ... (5a)
θgf- (-0.00162νd + 0.6415) <0.003 ... (5b)
These conditional expressions (5a) and (5b) define a more preferable conditional range based on the above-mentioned viewpoints and the like, among the conditional ranges defined by the conditional expression (5). Therefore, the above effect can be further enhanced by satisfying the conditional expression (5a), more preferably the conditional expression (5b).

The first group preferably has a positive power. By giving the first group positive power, the total length can be shortened.

With respect to the third lens, it is desirable that the following conditional expression (6) or (6a) is satisfied.
Nd13> 1.8 ... (6)
Nd13 ≧ 1.84666… (6a)
However,
Nd13: Refractive index of the third lens of the first group with respect to the d line,
Is.

In order to correct the distortion generated by the first lens and the second lens that have negative power, we want the third lens to have a strong curvature (that is, the curvature with a large absolute value), but the third lens in the first group By satisfying the conditional expression (6) or (6a) , it is possible to loosen the curvature of the lens surface (that is, reduce the absolute value of the curvature). Therefore, the occurrence of spherical aberration can be effectively reduced.

It is desirable that the second group has two or more positive lenses continuously from the object side. According to this configuration, by bearing the positive power with two or more lenses, the light rays incident on the second group can be gently bent, and the occurrence of various aberrations such as spherical aberration is effectively reduced. be able to.

It is desirable that the second group has a positive lens, a positive lens, a positive lens, a negative lens, an aperture, a negative lens, a positive lens, a positive lens, and a positive lens in this order from the object side. According to this configuration, since the power arrangements of the lenses constituting the second group are symmetrical with respect to the diaphragm, it is possible to reduce the occurrence of coma aberration, distortion, chromatic aberration of magnification, and the like.

It is desirable to have three or more aspherical lenses. By having three or more aspherical lenses in the imaging lens having the above-mentioned characteristic configuration, it becomes possible to specialize in specific aberration correction in each aspherical lens, and correction of various aberrations can be performed more effectively. Can be done. For example, when an aspherical lens is arranged on the first to third lenses from the object side in the first group, distortion aberration and curvature aberration can be particularly effectively corrected. When an aspherical lens is placed on the first to third lenses from the aperture, spherical aberration can be effectively corrected. When the aspherical lens is arranged on the first to third lenses from the image side, coma aberration and distortion can be effectively corrected.

The image pickup lens described above is suitable for use as an image pickup lens for a digital device with an image input function (for example, an interchangeable lens digital camera), and by combining this with an image pickup element or the like, the image of the subject is optically captured. It is possible to configure an imaging optical device that captures a lens and outputs it as an electrical signal. The imaging optical device is an optical device that forms a main component of a camera used for still image shooting or moving image shooting of a subject. For example, an imaging lens that forms an optical image of an object in order from the object (that is, the subject) side. It is configured to include an image sensor (image sensor) that converts an optical image formed by the image pickup lens into an electrical signal. Then, by arranging the image pickup lens having the above-mentioned characteristic configuration so that the optical image of the subject is formed on the light receiving surface (that is, the image pickup surface) of the image pickup element, it has high performance at a small size and low cost. It is possible to realize an image sensor and a digital device equipped with the image sensor.

Examples of digital devices with an image input function include cameras such as digital cameras, video cameras, surveillance cameras, security cameras, in-vehicle cameras, and videophone cameras. In addition, personal computers, portable digital devices (for example, mobile phones, smartphones (high-performance mobile phones), tablet terminals, mobile computers, etc.), these peripheral devices (scanners, printers, mice, etc.), and other digital devices (drives). Recorders, defense devices, etc.) with built-in or external camera functions. As can be seen from these examples, not only can a camera be configured by using an imaging optical device, but also a camera function can be added by mounting the imaging optical device on various devices. For example, it is possible to configure a digital device with an image input function such as a mobile phone with a camera.

FIG. 17 shows a schematic configuration example of a digital device DU as an example of a digital device with an image input function in a schematic cross section. The image pickup optical device LU mounted on the digital device DU shown in FIG. 17 includes an image pickup lens LN (AX: optical axis) that forms an optical image (image plane) IM of the object in order from the object (that is, the subject) side. An image pickup element SR that converts an optical image IM formed on a light receiving surface (imaging surface) SS by an image pickup lens LN into an electrical signal is provided, and a parallel flat plate (for example, an image pickup element SR) is provided as needed. Cover glass; corresponds to an optical low-pass filter, an optical filter such as an infrared cut filter, etc., which are arranged as needed.)

When a digital device DU with an image input function is configured by this image pickup optical device LU, the image pickup optical device LU is usually arranged inside the body, but when the camera function is realized, a form as required is adopted. It is possible to do. For example, the unitized imaging optical device LU may be configured to be rotatable with respect to the main body of the digital device DU, and the unitized imaging optical device LU may be used as an interchangeable lens with an image sensor as the digital device DU (that is, a lens). It may be configured to be removable from the main body of the interchangeable camera).

The image pickup lens LN is a wide-angle lens having a two-group configuration, and the second group of positive power is moved along the optical axis AX in a state where the position of the first group is fixed (that is, the position is fixed with respect to the image plane IM). By moving it to the object side, focusing on a short-range object is performed, and an optical image IM is formed on the light receiving surface SS of the image sensor SR. As the image sensor SR, for example, a solid-state image sensor such as a CCD type image sensor or a CMOS type image sensor having a plurality of pixels is used. Since the image pickup lens LN is provided so that the optical image IM of the subject is formed on the light receiving surface SS which is the photoelectric conversion unit of the image pickup element SR, the optical image IM formed by the image pickup lens LN is the image pickup element. It is converted into an electrical signal by SR.

In addition to the imaging optical device LU, the digital device DU includes a signal processing unit 1, a control unit 2, a memory 3, an operation unit 4, a display unit 5, and the like. The signal generated by the image pickup element SR is subjected to predetermined digital image processing, image compression processing, etc. as necessary by the signal processing unit 1, and is recorded in the memory 3 (semiconductor memory, optical disk, etc.) as a digital video signal. In some cases, it is transmitted to other devices via a cable or converted into an infrared signal (for example, the communication function of a mobile phone). The control unit 2 is composed of a microcomputer, and controls functions such as shooting functions (still image shooting function, moving image shooting function, etc.), image reproduction function, etc .; centralizes control of lens movement mechanism for focusing, camera shake correction, etc. Do it. For example, the control unit 2 controls the imaging optical device LU so as to perform at least one of still image shooting and moving image shooting of the subject. The display unit 5 is a portion including a display such as a liquid crystal monitor, and displays an image using an image signal converted by the image sensor SR or image information recorded in the memory 3. The operation unit 4 is a part including operation members such as an operation button (for example, a release button) and an operation dial (for example, a shooting mode dial), and transmits information input by the operator to the control unit 2.

Next, the first to fourth embodiments of the image pickup lens LN will be given, and the specific optical configuration thereof will be described in more detail. 1 to 4 are lens configuration diagrams corresponding to the imaging lens LNs constituting the first to fourth embodiments, and the optical cross section of the lens arrangement at the first focus position POS1 (subject infinity state) is shown. It is shown by. The first to fourth embodiments have a positive two-group configuration consisting of a positive power first group Gr1 and a positive power second group Gr2 in order from the object side, and are compact and wide-angle. -It has a structure suitable for a large-diameter interchangeable lens (focal length 28 mm, F1.4 class). In FIGS. 1 to 4, L1 # (# = 1, 2, ..., 6) is the # th lens from the object side in the first group Gr1, and L2 # (# = 1, 2, ..., 8) is This is the # th lens from the object side in the second group Gr2.

In the first to fourth embodiments, when focusing on a short-distance object, the first group Gr1 is fixed in position with respect to the image plane IM, and the second group Gr2 moves toward the object along the optical axis AX. To do. That is, the second group Gr2, which is a focus group, moves from the first focus position POS1 to the second focus position POS2 (subject short distance state) in focusing from infinity to a short distance toward the object side as shown by the arrow mF. To do. Further, in the third embodiment, it is desirable that the second group Gr2 is divided into a front group and a rear group at the position of the throttle ST, and is fed to the object side with different movement amounts (so-called floating). As a result, it becomes possible to correct the curvature of field caused by the fluctuation of the shooting distance, and the image quality at the shortest shooting distance is further improved. At this time, the aperture ST may move integrally with the front group or may move integrally with the rear group in consideration of the configuration of the lens barrel and the distance from the lens.

In the first to fourth embodiments, the first group Gr1 has a negative power first lens L11, a negative power second lens L12, a positive power third lens L13, and negative in order from the object side. It is composed of a power fourth lens L14, a positive power fifth lens L15, and a positive power sixth lens L16. The first lens L11 and the second lens L12 have a meniscus shape convex toward the object side, and the fourth lens L14 and the fifth lens L15 form a negative power junction lens LS. Then, by appropriately setting the power of the fourth lens L14 and the fifth lens L15, the combined power thereof (the power of the junction lens LS), and the like, good aberration correction is possible. Further, the positive power of the sixth lens L16 makes it possible to reduce the size of the second group Gr2 and improve the focus performance.

In the first embodiment, the second group Gr2 has a positive lens L21, a positive lens L22, a positive lens L23, a negative lens L24, an aperture ST, a negative lens L25, and a positive lens in order from the object side. It is composed of L26, a positive lens L27, and a positive lens L28. In the second to fourth embodiments, the second group Gr2 includes a positive lens L21, a positive lens L22, a negative lens L23, an aperture ST, a negative lens L24, and a positive lens L25 in order from the object side. , A positive lens L26 and a positive lens L27. In the first to fourth embodiments, the aperture (aperture aperture) ST is provided in the second group Gr2, and the lens located adjacent to the object side of the aperture ST is negative in the first embodiment. It is a lens L24, and in the second to fourth embodiments, it is a negative lens L23. If the partial dispersion ratio of the lenses located adjacent to the object side of the aperture ST is set within a predetermined range, it is possible to reduce axial chromatic aberration and prevent the occurrence of color bleeding.

In the image pickup lens LN (FIG. 1) of the first embodiment, each lens group is configured as follows in order from the object side. The first group Gr1 includes a composite aspherical lens (the image side surface is aspherical) composed of a negative meniscus lens L11 convex on the object side, a negative meniscus lens L12 convex on the object side, and a biconvex positive lens L13. It is composed of a negative junction lens LS composed of a biconcave negative lens L14 and a biconvex positive lens L15, and a biconvex positive lens L16 (power arrangement: negative / negative positive / negative positive / positive). The second group Gr2 includes a junction lens consisting of a positive meniscus lens L21 convex to the object side, a biconvex positive lens L22, a biconvex positive lens L23, and a biconcave negative lens L24, an aperture ST, and a biconcave. A junction lens consisting of a negative lens L25 and a biconvex positive lens L26 (image side surfaces are aspherical), a biconvex positive lens L27, and a positive meniscus lens L28 (both sides are aspherical) convex on the image side. It is configured (power arrangement: positive / positive / negative / ST / negative / positive / positive).

In the image pickup lens LN (FIG. 2) of the second embodiment, each lens group is configured as follows in order from the object side. The first group Gr1 is a composite aspherical lens (the image side surface is aspherical) composed of a negative meniscus lens L11 convex on the object side and a negative meniscus lens L12 convex on the object side, and a positive meniscus lens convex on the image side. It is composed of L13, a negative junction lens LS composed of a biconcave negative lens L14 and a positive meniscus lens L15 convex on the object side, and a biconvex positive lens L16 (power arrangement: negative negative positive / negative positive / positive). ). The second group Gr2 includes a junction lens consisting of a biconvex positive lens L21, a biconvex positive lens L22, and a biconcave negative lens L23, an aperture ST, a biconcave negative lens L24, and a biconvex positive lens L25. It is composed of a junction lens (the side surface of the image is aspherical), a biconvex positive lens L26, and a positive meniscus lens L27 (both sides are aspherical) convex on the image side (power arrangement: positive / negative / negative / negative / ST / Negative Positive Positive).

In the image pickup lens LN (FIG. 3) of the third embodiment, each lens group is configured as follows in order from the object side. The first group Gr1 includes a negative meniscus lens L11 convex on the object side, a negative meniscus lens L12 (the image side surface is aspherical) convex on the object side, a positive meniscus lens L13 convex on the image side, and both concaves. It is composed of a negative junction lens LS composed of a lens L14 and a biconvex positive lens L15, and a biconvex positive lens L16 (power arrangement: negative / negative positive / negative positive / positive). The second group Gr2 includes a junction lens consisting of a biconvex positive lens L21, a biconvex positive lens L22, and a biconcave negative lens L23, an aperture ST, a biconcave negative lens L24, and a biconvex positive lens L25. It is composed of a junction lens consisting of, a biconvex positive lens L26, and a positive meniscus lens L27 (both sides are aspherical) convex on the image side (power arrangement: positive / negative / ST / negative positive / positive). ..

In the image pickup lens LN (FIG. 4) of the fourth embodiment, each lens group is configured as follows in order from the object side. The first group Gr1 includes a composite aspherical lens (the image side surface is aspherical) composed of a negative meniscus lens L11 convex on the object side, a negative meniscus lens L12 convex on the object side, and a biconvex positive lens L13. It is composed of a negative junction lens LS composed of a biconcave negative lens L14 and a positive meniscus lens L15 convex on the object side, and a biconvex positive lens L16 (power arrangement: negative negative positive / negative positive / positive). The second group Gr2 includes a junction lens consisting of a biconvex positive lens L21, a biconvex positive lens L22, and a biconcave negative lens L23, an aperture ST, a biconcave negative lens L24, and a biconvex positive lens L25. It is composed of a junction lens consisting of a lens, a biconvex positive lens L26 (both sides are aspherical), and a positive meniscus lens L27 convex on the image side (power arrangement: positive / negative / ST / negative positive / positive). ..

Hereinafter, the configuration and the like of the image pickup lens in which the present invention has been carried out will be described in more detail with reference to construction data and the like of Examples. Examples 1 to 4 (EX1 to 4) given here are numerical examples corresponding to the above-described first to fourth embodiments, respectively, and are lens configuration diagrams representing the first to fourth embodiments. (FIGS. 1 to 4) show the corresponding optical configurations of Examples 1 to 4, respectively.

In the construction data of each embodiment, as the surface data, the surface number i (OB: object surface, ST: aperture, IM: image plane), the radius of curvature Ri (mm) on the paraxial axis, and the axis top surface spacing are in order from the left column. The refractive index Nd for Di (mm) and d-line (wavelength: 587.56 nm), and the Abbe number νd for d-line are shown. The variable shaft upper surface spacing Di (i: surface number, mm) that changes due to focusing is shown for each of the first focus position POS1 and the second focus position POS2.

The surface with * attached to the surface number i is an aspherical surface, and the surface shape is defined by the following equation (AS) using a local Cartesian coordinate system (x, y, z) with the surface vertex as the origin. To. The aspherical coefficient and the like are shown as the aspherical data. In the aspherical data of each embodiment, the coefficient of the term not shown is 0, and ^En = × 10 ^-n for all the data.
z = (c ・ h ² ) / [1 + √ {1- (1 + K) ・ c ²・ h ² }] + Σ (Aj ・ h ^j )… (AS)
However,
h: Height in the direction perpendicular to the z-axis (optical axis AX) (h ² = x ² + y ² ),
z: Sag amount in the optical axis AX direction at the position of height h (based on the surface apex),
c: Curvature at the surface vertex (reciprocal of radius of curvature Ri),
K: Conical constant,
Aj: j-order aspherical coefficient,
Is.

As various data, the focal length f (mm), F number (F value) FNO. , Total angle 2ω (°), maximum image height y'max (mm), total lens length TL (mm), back focal length BF (mm), partial dispersion ratio θgf as related data of conditional expression (5), first group The focal length f1 (mm) of Gr1, the focal length f2 (mm) of the second group Gr2, the focal length f14 (mm) of the fourth lens L4, the focal length f15 (mm) of the fifth lens L5, the fourth and fifth lenses. The focal length f1s (mm) of the junction lens LS composed of the lenses L4 and L5 and the focal length f1i of the lens L16 located closest to the image side in the first group Gr1 are shown. However, in the back focus BF, the distance from the final surface of the lens to the paraxial image plane IM is expressed by the air conversion length, and in the total length TL of the lens, the back focus BF is added to the distance from the frontmost surface of the lens to the final surface of the lens. It is a lens. In addition, Table 1 shows the values corresponding to the conditional expressions of each embodiment.

5 to 8 are longitudinal aberration diagrams corresponding to Examples 1 to 4 (EX1 to EX4), respectively, and (A) to (C) are first focus positions POS1, (D) to (F). Indicates various aberrations at the second focus position POS2, respectively. Further, in FIGS. 5 to 8, (A) and (D) are spherical aberration diagrams, (B) and (E) are astigmatism diagrams, and (C) and (F) are distortion aberration diagrams.

The spherical aberration diagram shows the amount of spherical aberration for the C line (wavelength 656.28 nm) shown by the single point chain line, the amount of spherical aberration for the d line (wavelength 587.56 nm) shown by the solid line, and the g line (wavelength 435.84 nm) shown by the broken line. The amount of spherical aberration is represented by the amount of deviation (mm) in the optical axis AX direction from the near-axis image plane, and the vertical axis represents the F value. In the astigmatism diagram, the broken line M represents the meridional image plane with respect to the d line, and the solid line S represents the sagittal image plane with respect to the d line by the amount of deviation (mm) in the optical axis AX direction from the paraxial image plane. The axis represents the image height Y'(mm). In the distortion diagram, the horizontal axis represents distortion (%) with respect to line d, and the vertical axis represents image height Y'(mm). The image height Y'corresponds to the maximum image height y'max in the image plane IM (half the diagonal length of the light receiving surface SS of the image sensor SR).

9, FIG. 11, FIG. 13 and FIG. 15 are transverse aberration diagrams corresponding to Examples 1 to 4 (EX1 to EX4) at the first focus position POS 1, respectively, and are FIGS. 10, 12, and 14 respectively. And FIG. 16 is a lateral aberration diagram corresponding to Examples 1 to 4 (EX1 to EX4) at the second focus position POS2, respectively. 9 to 16 show meridional coma (mm) in the left column and sagittal coma (mm) in the right column for each image height Y'(mm). As in FIGS. 5 to 8, the alternate long and short dash line is the C line (wavelength 656.28 nm), the solid line is the d line (wavelength 587.56 nm), and the broken line is the g line (wavelength 435.84 nm).

Example 1
Unit: mm
Surface data
i Ri (mm) Di (mm) Nd νd
0 (OB) ∞ ∞ ~ 105.61
1 70.017 2.50 1.68893 31.2
2 29.640 10.58
3 94.105 2.40 1.71300 53.9
4 31.773 0.05 1.51380 53.0
5 * 27.197 9.49
6 164.736 4.94 1.84666 23.8
7 -131.025 4.85
8 -46.832 2.15 1.56883 56.0
9 134.737 4.17 1.88300 40.8
10 -366.912 3.03
11 70.316 7.09 1.77250 49.6
12 -99.338 7.70 ~ 1.42
13 55.349 4.20 1.72916 54.7
14 289.177 0.15
15 111.310 4.00 1.69680 55.5
16 -158.345 0.15
17 322.096 5.79 1.59282 68.6
18 -37.124 1.50 1.73800 32.3
19 37.221 5.60
20 (ST) ∞ 5.78
21 -24.127 1.30 1.80610 33.3
22 47.257 5.35 1.83220 40.1
23 * -131.725 0.30
24 64.397 8.98 1.59282 68.6
25 -28.781 0.15
26 * -280.388 3.71 1.69350 53.2
27 * -55.502 38.47 ~ 44.77
28 (IM) ∞

Aspherical data surface 5
K = -1.81201E + 00
A4 = 5.07910E-06
A6 = -6.20262E-09
A8 = 1.15776E-11
A10 = -2.04179E-14
A12 = 1.90900E-17

Aspherical data page 23
K = 0.00000E + 00
A4 = 3.38686E-06
A6 = -1.03975E-09
A8 = 5.14761E-11
A10 = 1.18111E-14
A12 = -1.11410E-16

Aspherical data surface 26
K = 0.00000E + 00
A4 = -1.45264E-05
A6 = -2.74974E-08
A8 = 4.08509E-11
A10 = -1.22050E-13
A12 = 2.18038E-15
A14 = -3.26000E-18

Aspherical data page 27
K = 1.61294E + 00
A4 = -4.86948E-06
A6 = -2.36249E-08
A8 = 7.19463E-11
A10 = -3.12054E-13
A12 = 2.11838E-15
A14 = -2.42000E-18

Various data
f = 28.41
FNO. = 1.45
2ω = 75.42
y'max = 21.6
TL = 144.38
BF = 38.47
θgF = 0.5899
f1 = 151.32
f2 = 52.75
f14 = -60.83
f15 = 112.04
f1s = -137.42
f1i = 54.29

Example 2
Unit: mm
Surface data
i Ri (mm) Di (mm) Nd νd
0 (OB) ∞ ∞ ~ 107.60
1 66.672 2.50 1.68893 31.2
2 28.712 8.98
3 56.823 2.40 1.71300 53.9
4 28.412 0.05 1.51380 53.0
5 * 24.516 11.59
6 -2348.135 4.07 1.84666 23.8
7 -92.947 4.37
8-43.410 2.15 1.51742 52.2
9 80.132 4.33 1.90366 31.3
10 1085.535 1.91
11 73.043 6.88 1.78590 43.9
12 -91.416 8.54 ~ 2.58
13 46.311 6.62 1.69680 55.5
14 -141.275 0.15
15 194.148 6.41 1.59282 68.6
16 -35.968 1.60 1.69895 30.1
17 35.308 5.75
18 (ST) ∞ 5.93
19 -23.264 1.30 1.80610 33.3
20 136.595 3.84 1.80860 40.4
21 * -106.158 0.30
22 76.607 9.38 1.59282 68.6
23 -27.879 0.15
24 * -1000.000 4.67 1.58313 59.4
25 * -47.677 38.46 ~ 44.47
26 (IM) ∞

Aspherical data surface 5
K = -1.10465E + 00
A4 = 3.19310E-06
A6 = -6.36058E-09
A8 = 2.46244E-11
A10 = -5.90274E-14
A12 = 5.62500E-17

Aspherical data surface 21
K = 0.00000E + 00
A4 = 7.43892E-06
A6 = -1.81682E-09
A8 = 1.12774E-10
A10 = -5.38027E-13
A12 = 1.58865E-15
A14 = -2.11000E-18

Aspherical data surface 24
K = 0.00000E + 00
A4 = -8.53923E-06
A6 = -2.53210E-08
A8 = 1.21664E-10
A10 = -4.87477E-13
A12 = 1.66812E-15
A14 = -1.32000E-18

Aspherical data 25th surface
K = -2.80034 E-02
A4 = -2.22686E-06
A6 = -1.70714E-08
A8 = 4.04178E-11
A10 = -7.22433E-15
A12 = 1.79700E-17
A14 = 8.80000E-19

Various data
f = 28.00
FNO. = 1.45
2ω = 76.22
y'max = 21.6
TL = 142.33
BF = 38.46
θgF = 0.6028
f1 = 196.28
f2 = 51.26
f14 = -54.10
f15 = 95.55
f1s = -126.94
f1i = 52.63

Example 3
Unit: mm
Surface data
i Ri (mm) Di (mm) Nd νd
0 (OB) ∞ ∞ ~ 138.17
1 84.724 2.50 1.83400 37.4
2 28.860 5.07
3 35.391 2.50 1.74320 49.3
4 * 23.788 14.14
5 -106.146 3.20 1.90366 31.3
6 -68.380 3.84
7 -40.703 2.15 1.51680 64.2
8 630.888 4.10 1.84666 23.8
9 -145.820 0.20
10 78.882 7.80 1.83481 42.7
11 -108.522 6.87 ~ 1.92
12 47.354 7.71 1.72916 54.7
13 -130.704 0.15
14 218.659 6.50 1.59282 68.6
15 -39.980 1.76 1.69895 30.1
16 41.230 7.32
17 (ST) ∞ 6.54
18 -24.171 1.30 1.80610 33.3
19 73.665 4.76 1.61800 63.4
20 -88.480 1.00
21 58.034 9.29 1.59282 68.6
22 -35.531 0.15
23 * -591.406 4.54 1.74320 49.3
24 * -51.826 38.45 ~ 43.39
25 (IM) ∞

Aspherical data 4th surface
K = -2.11415E-01
A4 = -3.13492E-06
A6 = -6.95430E-09
A8 = 7.46840E-12
A10 = -2.12227E-14

Aspherical data page 23
K = 0.00000E + 00
A4 = -1.26144E-05
A6 = -8.93725E-09
A8 = -6.31579E-11
A10 = 2.26171E-13
A12 = -1.83200E-16

Aspherical data surface 24
K = 1.10874E + 00
A4 = -2.22064E-06
A6 = -8.29680E-09
A8 = -3.55044E-11
A10 = 1.88045E-13
A12 = -2.13667E-16
A14 = 6.33384E-20

Various data
f = 28.00
FNO. = 1.45
2ω = 76.22
y'max = 21.6
TL = 141.84
BF = 38.45
θgF = 0.6028
f1 = 447.46
f2 = 52.10
f14 = -73.91
f15 = 140.23
f1s = -164.01
f1i = 55.77

Example 4
Unit: mm
Surface data
i Ri (mm) Di (mm) Nd νd
0 (OB) ∞ ∞ ~ 97.87
1 58.571 2.60 1.80610 33.3
2 29.732 6.90
3 43.559 2.50 1.70154 41.2
4 26.564 0.05 1.51380 53.0
5 * 22.956 11.38
6 449.499 4.01 1.84666 23.8
7 -123.672 4.69
8-44.185 2.15 1.51680 64.2
9 61.803 4.61 1.90366 31.3
10 175.163 4.25
11 69.416 6.61 1.78590 43.9
12 -91.544 7.59 ~ 1.19
13 45.255 6.73 1.69680 55.5
14 -130.769 0.15
15 155.733 6.06 1.59282 68.6
16 -37.096 1.75 1.69895 30.1
17 40.187 4.30
18 (ST) ∞ 6.19
19 -23.672 1.30 1.80610 33.3
20 42.685 5.54 1.59282 68.6
21 -86.448 0.35
22 * 74.406 7.03 1.74320 49.3
23 * -40.669 0.15
24-75.737 6.50 1.69680 55.5
25 -30.960 38.44 ~ 45.15
26 (IM) ∞

Aspherical data surface 5
K = -1.12166E + 00
A4 = 4.89075E-06
A6 = -3.96587E-09
A8 = 2.47445E-11
A10 = -6.08112E-14
A12 = 7.08946E-17

Aspherical data surface 22
K = 0.00000E + 00
A4 = -5.15675E-06
A6 = 9.03138E-09
A8 = -1.69741E-11
A10 = 9.37387E-16

Aspherical data page 23
K = -1.38896E + 00
A4 = 6.15995E-06
A6 = -1.84291E-09
A8 = 7.07932E-11
A10 = -4.62572E-13
A12 = 1.30408E-15
A14 = -1.47433E-18

Various data
f = 28.50
FNO. = 1.45
2ω = 75.22
y'max = 21.6
TL = 141.83
BF = 38.44
θgF = 0.6028
f1 = 249.48
f2 = 50.72
f14 = -49.48
f15 = 103.55
f1s = -93.94
f1i = 51.11

DU Digital Equipment LU Imaging Optical Device LN Imaging Lens Gr1 1st Group Gr2 2nd Group L1 # # 1 lens from the object side in the 1st group (# = 1, 2, ..., 6; 1st to 6th lenses)
L2 # # 2nd lens from the object side in the 2nd group (# = 1, 2, ..., 8)
LS junction lens ST aperture SR image sensor SS light receiving surface (imaging surface)
IM image plane (optical image)
AX Optical axis 1 Signal processing unit 2 Control unit 3 Memory 4 Operation unit 5 Display unit

Claims (12)

In order from the object side, it consists of the first group and the second group with positive power.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
An imaging lens characterized by satisfying the following conditional equations (1) , (2), (3b) and (4) ;
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
−2.09 ≦ φ14 / φ15 <−1.5… (3 b )
Nd15> 1.8 ... (4)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Is. In order from the object side, it consists of the first group and the second group with positive power.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
An imaging lens characterized by satisfying the following conditional equations (1) to (3) and (4a);
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
-3 <φ14 / φ15 <-1.5 ... (3)
Nd15 ≧ 1.88300… (4a)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Is. In order from the object side, it consists of the first group and the second group with positive power.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
An imaging lens characterized by satisfying the following conditional equations (1) to (4) and (6a);
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
-3 <φ14 / φ15 <-1.5 ... (3)
Nd15> 1.8 ... (4)
Nd13 ≧ 1.84666… (6a)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Nd15: Refractive index for the d-line of the 5th lens,
Nd13: Refractive index with respect to the d-line of the third lens,
Is. In order from the object side, it consists of the first group and the second group with positive power.
The first group, in order from the object side, has a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a negative power, and a positive power. With a fifth lens,
The first lens and the second lens have a meniscus shape that is convex toward the object.
A junction lens is composed of the fourth lens and the fifth lens.
Focusing on a short-distance object is performed by moving the second group to the object side while the position of the first group is fixed.
An imaging lens characterized by satisfying the following conditional equations (1), (2) and (3c);
-0.7 <φ14 / φ <-0.3 ... (1)
0.1 <φ15 / φ <0.4 ... (2)
−2.09 ≦ φ14 / φ15 ≦ -1.77… (3c)
However,
φ14: Power of the 4th lens,
φ15: Power of the 5th lens,
φ: Power of the whole system,
Is. The imaging lens according to any one of claims 1 to 4 , wherein the lens located closest to the image side in the first group has a positive power. The imaging lens according to any one of claims 1 to 5 , wherein a lens located adjacent to the object side of the diaphragm satisfies the following conditional expression (5);
θgf- (-0.00162νd + 0.6415) <0.012 ... (5)
However,
θgf: partial dispersion ratio of lens material,
θgf = (Ng-NF) / (NF-NC)
Ng: Refractive index with respect to g-line,
NF: Refractive index for F line,
NC: Refractive index for C line,
νd: Abbe number related to d-line of lens material,
Is. The imaging lens according to any one of claims 1 to 6 , wherein the first group has a positive power. The imaging lens according to any one of claims 1 to 7, wherein the second group has two or more positive lenses continuously from the object side. Any of claims 1 to 8, wherein the second group has a positive lens, a positive lens, a positive lens, a negative lens, an aperture, a negative lens, a positive lens, a positive lens, and a positive lens in order from the object side. The imaging lens according to item 1. The imaging lens according to any one of claims 1 to 9, wherein the image pickup lens has three or more aspherical lenses. The image pickup lens according to any one of claims 1 to 10 and an image pickup element for converting an optical image formed on the image pickup surface into an electrical signal are provided, and a subject is provided on the image pickup surface of the image pickup element. An imaging optical device characterized in that the imaging lens is provided so as to form an optical image of the above. A digital device comprising the imaging optical device according to claim 11, wherein at least one of a still image shooting and a moving image shooting of a subject is added.

Images