JP5839174B2 - Imaging lens, photographing lens unit, and imaging apparatus - Google Patents

Description

  The present invention relates to an imaging lens, a photographic lens unit, and an imaging device, and more particularly to an inner focus imaging lens, a photographic lens unit and an imaging device including the imaging lens.

  In recent years, digital cameras have been widely used in place of silver-salt film type cameras, and there have been various requests from users for digital cameras, and digital cameras rich in individuality have been proposed. Among these digital cameras, improvement in convenience when carried is a high priority as a technical problem to be solved, and a small photographic optical system (imaging lens) is required to realize this.

There are also many users who require that the angle of view of the photographic lens is wide. Conventionally, as a wide-angle lens, many retrofocus lens configurations have been proposed in which a lens group having a negative refractive power as a whole and a lens group having a positive refractive power as a whole are arranged.
However, the retrofocus type wide-angle lens is disadvantageous in reducing the size of the lens because the back focus is longer than the focal length. In addition, since a single-lens reflex camera has a mirror disposed between the lens and the image plane, it is necessary to secure a space for arranging the mirror with a long back focus, which is disadvantageous for miniaturization.

  On the other hand, in recent years, a mirrorless lens-interchangeable camera that does not require a space for arranging a mirror is known, and a miniaturized wide-angle lens has been proposed (for example, see Patent Documents 1 to 3). ).

However, the photographic lens disclosed in Patent Document 1 is a single-focus lens reduced in size, but is disadvantageous for high-speed AF (autofocus) due to focusing by the entire extension.
In addition, the lenses disclosed in Patent Document 2 and Patent Document 3 attempt to reduce the focus group by the rear focus and the optical system, but there is room for further miniaturization because the back focus is long.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an inner focus type wide-angle imaging lens that achieves downsizing and has good optical performance and can correct aberrations that occur during focusing. With the goal.
Another object of the present invention is to provide an imaging lens unit and an imaging apparatus that use the inner focus type wide-angle imaging lens as an imaging optical system.

In order to solve the above problems, the imaging lens according to the present invention is:
In order from the object side to the image side, a first group having positive refractive power, an aperture stop, and a second group having positive refractive power are arranged.
The first group includes, in order from the object side to the image side, a negative lens having a concave surface on the object side, a positive lens, and a negative lens.
The second group includes a G2A group having a positive refractive power and a G2B group having a negative refractive power in order from the object side to the image side, and the G2A group moves from the object side to the image side. The G2B group is composed of two negative lenses, and is composed of a cemented lens composed of one negative lens and one positive lens, and a positive lens.
When focusing from an infinitely distant object to a close object, the G2A group moves to the object side along the optical axis direction and satisfies the following conditional expressions (1), (2), and (3) An imaging lens characterized by the following.
(1) 0.2 <f2A / f2 <0.4
(2) 2.2 <| f · m / ΔX2A | <2.8
(3) 2.2 <TL / Y <3.0
Where f2 is the focal length of the second group, f2A is the focal length of the G2A group, f is the focal length of the entire lens system when focusing on an object at infinity, and m is the lateral magnification when the photographing magnification is -1/20 times. , ΔX2A is the amount of movement from the position of the G2A group at the time of focusing on infinity to the position where the shooting magnification is focused to −1/20, Y is the maximum image height, TL is the object of the lens on the most object side of the lens system The actual distances on the optical axis from the lens surface on the side to the image plane are respectively represented.

In order to solve the above problems, a photographic lens unit according to the present invention is a photographic lens unit comprising the imaging lens of the present invention.
In order to solve the above problems, an imaging apparatus according to the present invention is an imaging apparatus including the imaging lens of the present invention.

According to the imaging lens of the present invention, it is possible to provide an inner focus type wide-angle imaging lens that achieves downsizing and has good optical performance and can correct aberrations that occur during focusing. Can do.
In addition, it is possible to provide an imaging lens unit and an imaging apparatus that include the imaging lens and can be miniaturized.

It is a schematic diagram of the cross section which shows one embodiment of the structure of the imaging lens of this invention. FIG. 2 is an aberration curve diagram showing spherical aberration, astigmatism, distortion aberration, and coma aberration when the imaging lens shown in FIG. 1 is in focus at infinity. FIG. 2 is an aberration curve diagram showing spherical aberration, astigmatism, distortion, and coma aberration when the imaging lens shown in FIG. 1 has an imaging magnification β = −1 / 20 times. It is a schematic diagram of the cross section which shows the other embodiment of the structure of the imaging lens of this invention. FIG. 5 is an aberration curve diagram showing spherical aberration, astigmatism, distortion, and coma aberration in the infinite focus state of the imaging lens shown in FIG. 4. FIG. 5 is an aberration curve diagram showing spherical aberration, astigmatism, distortion, and coma aberration when the imaging lens shown in FIG. 4 has a photographing magnification β = −1 / 20 times. It is a schematic diagram of the cross section which shows other embodiment of the structure of the imaging lens of this invention. FIG. 8 is an aberration curve diagram showing spherical aberration, astigmatism, distortion aberration, and coma aberration when the imaging lens shown in FIG. 7 is in focus at infinity. FIG. 8 is an aberration curve diagram showing spherical aberration, astigmatism, distortion, and coma aberration when the imaging lens shown in FIG. 7 has an imaging magnification β = −1 / 20 times. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the digital camera which shows one Embodiment of the camera (portable information terminal device) provided with the imaging lens of this invention, (A) is the perspective view seen from the front side at the time of carrying (collapsed), (B ) Is a perspective view showing a part of the front side during use (when the lens is extended), and (C) is a perspective view of the back side. It is a block diagram which shows the outline of an example of the system structure of a camera provided with the imaging lens of this invention.

  Hereinafter, an imaging lens, a photographing lens unit, and an imaging device according to the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the embodiments of the examples shown below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art. Any aspect is included in the scope of the present invention as long as the operations and effects of the present invention are exhibited.

In the imaging lens of the present invention, in order from the object side to the image side, a first group having a positive refractive power, an aperture stop, and a second group having a positive refractive power are arranged.
The first group includes, in order from the object side to the image side, a negative lens having a concave surface on the object side, a positive lens, and a negative lens.
The second group includes a G2A group having a positive refractive power and a G2B group having a negative refractive power in order from the object side to the image side, and the G2A group moves from the object side to the image side. The G2B group is composed of two negative lenses, and is composed of a cemented lens composed of one negative lens and one positive lens, and a positive lens.
When focusing from an infinitely distant object to a close object, the G2A group moves to the object side along the optical axis direction and satisfies the following conditional expressions (1), (2), and (3).
(1) 0.2 <f2A / f2 <0.4
(2) 2.2 <| f · m / ΔX2A | <2.8
(3) 2.2 <TL / Y <3.0
However, f2 is the focal length of the second group, f2A is the focal length of the G2A group, f is the focal length of the entire lens system when focusing on an object at infinity (hereinafter simply referred to as the focal length of the entire lens system), m is a lateral magnification at a photographing magnification of −1/20 times, ΔX2A is a movement amount from the position of the G2A group at the time of focusing on infinity to a position at which the photographing magnification is focused at −1/20 times, and Y is a maximum image height. , TL represents the actual distance (hereinafter simply referred to as the total optical length) of the distance on the optical axis from the object-side lens surface of the lens system closest to the object side to the image plane .

  Conditional expression (1) defines the ratio of the focal length f2A of the G2A group to the focal length f2 of the second group. When the value of f2A / f2 is equal to or greater than the upper limit (0.4), the positive refractive power of the focus group becomes weak, and in order to maintain the power of the second group, the negative refractive power of the G2B group becomes weak. It is difficult to correct spherical aberration generated by the positive lens on the object side from the G2B group. In addition, since the amount of movement of the focus group increases, it takes time to focus. On the other hand, when the positive refractive power of the focus group becomes strong below the lower limit (0.2), the spherical aberration increases in the under direction, and the G2B group cannot fully correct the spherical aberration.

  Conditional expression (2) defines the movement amount ΔX2A of the G2A group with respect to the focusing feeding amount F · m by the whole feeding. When focusing on a short distance object, the larger the value of | f · m / ΔX2A |, the smaller the amount of movement of the G2A group. However, if the value of | f · m / ΔX2A | is equal to or greater than the upper limit (2.8), the amount of movement becomes small, but the aberration fluctuation during focusing becomes large and good optical performance cannot be maintained. On the other hand, when the lower limit (2.2) or less is reached, the amount of movement of the focus group increases, and the total lens length increases.

Conditional expression (3) defines the ratio of the optical total length TL to the maximum image height Y.
If the value of TL / Y is equal to or greater than the upper limit (3.0), it means that the optical system becomes large. On the other hand, when the value is lower than the lower limit (2.2), it is advantageous for downsizing the optical system, but it becomes difficult to correct spherical aberration, coma aberration, and field curvature.

In the imaging lens of the present invention, it is preferable that the following conditional expression (4) is satisfied when the focal length of the first group is f1.
(4) 1.0 <f1 / f <2.0
Conditional expression (4) defines the ratio of the focal length f1 of the first group to the focal length f of the entire lens system. When the value of f1 / f is equal to or greater than the upper limit (2.0), the first group The focal length of the lens becomes too long, and the total length also increases. In order not to change the overall length, the focal length of the second lens group must be reduced, so that spherical aberration increases, and field curvature and astigmatism worsen. On the other hand, when the value is lower than the lower limit (1.0), the focal length of the first group becomes too short, and it becomes difficult to correct spherical aberration occurring in the first group. Therefore, a more compact wide-angle lens can be provided by satisfying conditional expression (4).

Furthermore, the imaging lens of the present invention has the following conditional expression when the distance from the most image side surface of the first group to the most object side surface of the second group at the time of focusing on infinity is D12: It is preferable to satisfy (5).
(5) 0.2 <D12 / f <0.3
Conditional expression (5) defines the ratio of D12 to the focal length f of the entire lens system. When the value of D12 / f is equal to or greater than the upper limit (0.3), the first group and the second group This increases the distance, which is disadvantageous for downsizing the entire lens length. On the other hand, when the value is lower than the lower limit (0.2), the distance between the first group and the second group becomes too narrow, and the focusing space by the G2A group is lost. By satisfying conditional expression (5), a further compact wide-angle lens can be provided.

  As illustrated in FIG. 1, in the embodiment of the present invention, the parallel plate FT disposed on the image plane side of the second group includes various filters such as an optical low-pass filter and an infrared cut filter, a CCD sensor, and the like. Assuming a cover glass (seal glass) of the light receiving element, a transparent parallel plate equivalent to these is shown.

Hereinafter, various aberrations and specific numerical data of the imaging lens according to the embodiment of the present invention are shown. The meanings of symbols in each embodiment (Example) are as follows.
f: focal length of entire system F: F number ω: half angle of view (degrees)
R: radius of curvature of lens surface (for aspheric surfaces, paraxial radius of curvature)
D: Surface spacing Nd: Refractive index νd of lens material: Abbe number K of lens material: Aspherical conical constant A4: Fourth-order aspherical constant A6: Sixth-order aspherical constant A8: Eighth-order aspherical constant A10 : 10th-order aspheric constant

Also, the aspherical shape is the reciprocal of the paraxial radius of curvature (paraxial curvature): C, the height from the optical axis: H, the conic constant: K, and the aspherical coefficients of the above orders, where X is the optical axis direction. The aspherical amount in is represented by the following well-known mathematical expression, and a shape is specified by giving a paraxial radius of curvature, a conical constant, and an aspherical coefficient.

[First Embodiment (Example 1)]
FIG. 1 shows a configuration example of an imaging lens according to the first embodiment of the present invention.
A first group G1 having a positive refractive power and a rear second group G2 having a positive refractive power in order from the object side along the optical axis, and further, the second group G2 has a positive refraction in order from the object side. The G2A group has a strong power and the G2B group has a negative refractive power. The G2A group has an aperture stop S between the first group and the second group. It moves in the direction (object side) indicated by the arrow along the optical axis direction.
The first group includes, in order from the object side, a biconcave lens L1, a biconvex lens L2, and a negative meniscus lens L3 having a concave surface facing the object side.
The G2A group is composed of a cemented lens of a biconcave lens L4 and a biconvex lens L5 having a strong concave surface facing the object side, and a biconvex lens L6. The G2B group is a negative meniscus having a biconcave lens L7 and a strong concave surface facing the object side. It consists of a lens L8.
On the further image side of the G2B group, parallel plates FT1 and FT2 are installed. I represents an image plane.

  The optical characteristics (R, D, Nd, νd) in this embodiment are as shown in Table 1 below. In Table 1, a surface with an asterisk “*” in the surface number represents an aspheric surface.

The aspherical conic constant K and the aspherical coefficient Ai (i = 4, 6, 8, 10) are shown below. Note that En is the third surface representing the power of 10.
K = 0
A4 = -2.04311E-005
A6 = 1.33162E-007
A8 = -4.03667E-009
A10 = 2.37536E-010
12th page
K = 0
A4 = 1.49820E-004
A6 = -1.71118E-007
A8 = 2.92811E-009
A10 = -3.21389E-012
16th page
K = 0
A4 = -5.89759E-005
A6 = 5.70307E-007
A8 = -2.52482E-009
A10 = 2.26612E-012

Table 2 below shows the values of the variable surface distances D7 and D16 when the object distance is focused at infinity and when imaging with the imaging magnification β = −1 / 20.

The coefficients of conditional expressions (1) to (5) in the present embodiment are as follows.
(1) f2A / f2 = 0.22
(2) | f · m / ΔX2A | = 2.27
(3) TL / Y = 2.43
(4) f1 / f = 1.24
(5) D12 / f = 0.27

2 and 3 are aberration diagrams in the lens configuration shown in FIG. 1, FIG. 2 is an aberration diagram in an infinitely focused state, and FIG. 3 is a photographing magnification β = −1 / 20 times. It is an aberration diagram.
The broken line in the spherical aberration diagram represents the sine condition, the solid line in the astigmatism diagram represents the sagittal, and the broken line represents the meridional. Further, “g” and “d” represent the g line and the d line, respectively.

[Second Embodiment (Example 2)]
FIG. 4 shows a configuration example of the imaging lens according to the second embodiment of the present invention.
A first group G1 having a positive refractive power and a second group G2 having a positive refractive power in order from the object side along the optical axis, and the second group G2 has a positive refractive power in order from the object side. G2A group, and G2B group having negative refractive power, and has an aperture stop S between the first group and the second group, and focusing from an infinite object to a short-distance object is performed by the G2A group. It moves in the direction indicated by the arrow (object side) along the axial direction.
The first group includes, in order from the object side, a biconcave lens L1, a biconvex lens L2, and a negative meniscus lens L3 having a concave surface facing the object side.
The G2A group includes a cemented lens of a biconcave lens L4 and a biconvex lens L5 having a stronger concave surface directed toward the object side, and a biconvex lens L6. The G2B group includes a biconcave lens L7 and a negative meniscus having a stronger concave surface directed toward the object side. It consists of a lens L8.
On the further image side of the G2B group, parallel plates FT1 and FT2 are installed. I represents an image plane.

  The optical characteristics (R, D, Nd, νd) in this embodiment are as shown in Table 3 below. In Table 3, a surface with an asterisk “*” in the surface number represents an aspherical surface.

The aspherical conic constant K and the aspherical coefficient Ai (i = 4, 6, 8, 10) are shown below. Note that En is the third surface representing the power of 10.
K = 0
A4 = 1.40850E-05
A6 = -2.54437E-07
A8 = 2.23994E-08
A10 = -3.10276E-10
12th page
K = 0
A4 = 1.08130E-04
A6 = -3.97940E-08
A8 = -2.85470E-10
A10 = 1.74853E-11
16th page
K = 0
A4 = -2.40125E-05
A6 = 1.81550E-07
A8 = -3.33462E-10
A10 = -5.75529E-12

Table 4 below shows the values of the variable surface distances D7 and D16 when the object distance is focused at infinity and when imaging with an imaging magnification β = −1 / 20.

The coefficients of conditional expressions (1) to (5) in the second embodiment are as follows.
(1) f2A / f2 = 0.21
(2) | f · m / ΔX2A | = 2.61
(3) TL / Y = 2.43
(4) f1 / f = 1.26
(5) D12 / f = 0.24

FIGS. 5 and 6 are aberration diagrams in the lens configuration shown in FIG. 4. FIG. 5 is an aberration diagram in an infinitely focused state, and FIG. 6 is an image taking magnification β = −1 / 20 times. It is an aberration diagram.
The broken line in the spherical aberration diagram represents the sine condition, the solid line in the astigmatism diagram represents the sagittal, and the broken line represents the meridional. Further, “g” and “d” represent the g line and the d line, respectively.

[Third Embodiment (Example 3)]
FIG. 7 shows a configuration example of an imaging lens according to the third embodiment of the present invention.
A first group G1 having a positive refractive power and a second group G2 having a positive refractive power in order from the object side along the optical axis, and the second group G2 has a positive refractive power in order from the object side. G2A group, and G2B group having negative refractive power, and has an aperture stop S between the first group and the second group, and focusing from an infinite object to a short-distance object is performed by the G2A group. It moves in the direction indicated by the arrow (object side) along the axial direction.
The first group includes a biconcave lens L1, a biconvex lens L2, and a biconcave lens L3 in order from the object side.
The G2A group includes a cemented lens of a biconcave lens L4 and a biconvex lens L5 having a stronger concave surface directed toward the object side, and a biconvex lens L6. The G2B group includes a biconcave lens L7 and a negative meniscus having a stronger concave surface directed toward the object side. It consists of a lens L8.
On the further image side of the G2B group, parallel plates FT1 and FT2 are installed. I represents an image plane.

  The optical characteristics (R, D, Nd, νd) in this embodiment are as shown in Table 5 below. In Table 5, a surface with an asterisk “*” in the surface number represents an aspheric surface.

The aspherical conic constant K and the aspherical coefficient Ai (i = 4, 6, 8, 10) are shown below. Note that En is the third surface representing the power of 10.
K = 0
A4 = 8.54199E-06
A6 = -2.40319E-07
A8 = 2.57028E-08
A10 = -5.39845E-10
12th page
K = 0
A4 = 1.09494E-04
A6 = -2.37444E-07
A8 = 1.52876E-09
A10 = 4.25111E-12
16th page
K = 0
A4 = -4.66795E-05
A6 = 3.82413E-07
A8 = -5.34259E-10
A10 = -5.51254E-12

Table 6 below shows the values of the variable surface distances D7 and D16 when the object distance is focused at infinity and when the imaging magnification β is −1/20.

The coefficients of conditional expressions (1) to (5) in the third embodiment are as follows.
(1) f2A / f2 = 0.30
(2) | f · m / ΔX2A | = 2.56
(3) TL / Y = 2.43
(4) f1 / f = 1.51
(5) D12 / f = 0.24

FIGS. 8 and 9 show aberration diagrams in the lens configuration shown in FIG. 7. FIG. 8 is an aberration diagram in the infinite focus state, and FIG. 9 is when the imaging magnification β = −1 / 20 times. It is an aberration diagram.
The broken line in the spherical aberration diagram represents the sine condition, the solid line in the astigmatism diagram represents the sagittal, and the broken line represents the meridional. Further, “g” and “d” represent the g line and the d line, respectively.

  The inner focus type wide-angle imaging lens of the present invention has good optical performance and can correct aberrations generated during focusing well.

[Photographing lens unit, imaging device]
The photographic lens unit of the present invention includes the imaging lens of the present invention. The imaging apparatus of the present invention includes the imaging lens of the present invention, and includes the photographing lens unit of the present invention as a zoom lens.
An imaging apparatus employing the photographing lens unit of the present invention as a zoom lens will be described with reference to FIGS.

A camera (including a portable information terminal device) as an example of an embodiment of an imaging apparatus of the present invention is shown in FIGS.
FIG. 10A is a perspective view schematically showing the appearance of the retracted state of the camera as viewed from the front side that is the object, that is, the subject side, and FIG. FIG. 11C is a perspective view schematically showing the appearance of the camera as seen from the back side that is the photographer side, and FIG. 12 shows the functional configuration of the camera. It is a block diagram.
In addition, although the camera is demonstrated as an example of embodiment, it is not limited to a camera, You may incorporate a camera function in portable information terminal devices, such as what is called PDA (personal data assistant) and a mobile telephone. Although such a portable information terminal device also has a slightly different appearance, it includes substantially the same functions and configuration as a camera, and the photographing lens unit of the present invention is adopted in such a portable information terminal device. be able to.

As shown in FIGS. 10A, 10B, and 10C, the camera 10 includes a photographing lens 12, a shutter button 13, a zoom lever 14, a viewfinder 15, a strobe 16, a liquid crystal monitor 17, an operation button 18, and a power switch. 19, a memory / communication card slot 20 and the like.
Furthermore, as shown in FIG. 11, the camera 10 also includes a light receiving element 201, a signal processing device 202, an image processing device 203, a central processing unit (CPU) 204, a semiconductor memory 205, a communication card 206, and the like.

  The camera 10 includes a photographing lens 12 that is a photographing optical system and a light receiving element 201 that serves as an area sensor such as a CCD (charge coupled device) imaging element. An image is read by the light receiving element 201. As the photographing lens 12, the imaging lens of the present invention is used. Specifically, the photographing lens unit is configured using a lens or the like that is an optical element constituting the imaging lens of the present invention. This photographic lens unit has a mechanism for holding each lens and the like so that the lens can be moved at least for each lens group. The photographing lens 12 incorporated in the camera is usually incorporated in the form of this photographing lens unit.

The output of the light receiving element 201 is processed by the signal processing device 202 controlled by the central processing unit 204 and converted into digital image information. The image information digitized by the signal processing device 202 is subjected to predetermined image processing in the image processing device 203 which is also controlled by the central processing unit 204, and then recorded in the semiconductor memory 205 such as a nonvolatile memory. In this case, the semiconductor memory 205 may be a memory card loaded in the memory / communication card slot 20 or a semiconductor memory built in the camera body.
The liquid crystal monitor 17 can display an image being photographed, or can display an image recorded in the semiconductor memory 205. The image recorded in the semiconductor memory 205 can also be transmitted to the outside via a communication card 206 or the like loaded in the memory / communication card slot 20.

  When the camera 10 is carried, the photographing lens 12 is in a retracted state and buried in the body of the camera 10 as shown in FIG. 11A. When the user operates the power switch 19 to turn on the power, 11 (B), the lens barrel is extended and protrudes from the body of the camera 10. When the zoom lever 14 is operated, zooming by so-called digital zoom is performed in which the cutout range of the image is changed and pseudo-displacement is performed. At this time, it is desirable that the optical system of the finder 15 is also scaled in conjunction with the change in the angle of view of the photographing lens 12. In many cases, focusing is performed by half-pressing the shutter button 13. When the shutter button 13 is further pressed, shooting is performed, and thereafter, the processing described above is performed.

  When an image recorded in the semiconductor memory 205 is displayed on the liquid crystal monitor 17 or transmitted to the outside using the communication card 206 or the like, the operation button 18 is used. The semiconductor memory 205, the communication card 206, and the like are used by being inserted into dedicated or general-purpose slots 20, respectively.

  As described above, by configuring the photographing lens unit using the inner focus type wide-angle imaging lens of the present invention, the photographing lens unit can be reduced in size, and the imaging apparatus including the photographing lens unit is provided. Can be miniaturized.

G1 1st group G2 2nd group S Aperture L Lens R Radius of curvature of lens surface FT Parallel plate I Image surface

Japanese Patent Application Laid-Open No. 09-258098 JP 2009-258158 A JP 2009-237542 A

Claims (5)

In order from the object side to the image side, a first group having positive refractive power, an aperture stop, and a second group having positive refractive power are arranged.
The first group includes, in order from the object side to the image side, a negative lens having a concave surface on the object side, a positive lens, and a negative lens.
The second group includes a G2A group having a positive refractive power and a G2B group having a negative refractive power in order from the object side to the image side, and the G2A group moves from the object side to the image side. The G2B group is composed of two negative lenses, and is composed of a cemented lens composed of one negative lens and one positive lens, and a positive lens.
When focusing from an infinitely distant object to a close object, the G2A group moves to the object side along the optical axis direction and satisfies the following conditional expressions (1), (2), and (3) An imaging lens characterized by
(1) 0.2 <f2A / f2 <0.4
(2) 2.2 <| f · m / ΔX2A | <2.8
(3) 2.2 <TL / Y <3.0
Where f2 is the focal length of the second group, f2A is the focal length of the G2A group, f is the focal length of the entire lens system when focusing on an object at infinity, and m is the lateral magnification when the photographing magnification is -1/20 times. , ΔX2A is the amount of movement from the position of the G2A group at the time of focusing on infinity to the position where the shooting magnification is focused to −1/20, Y is the maximum image height, TL is the object of the lens on the most object side of the lens system The actual distances on the optical axis from the lens surface on the side to the image plane are respectively represented. 2. The imaging lens according to claim 1, wherein the following conditional expression (4) is satisfied, where f1 is a focal length of the first group.
(4) 1.0 <f1 / f <2.0 When the distance from the most image-side surface of the first group to the most object-side surface of the second group at the time of focusing on infinity is D12, the following conditional expression (5) is satisfied: The imaging lens according to claim 1 or 2.
(5) 0.2 <D12 / f <0.3   A photographic lens unit comprising the imaging lens according to claim 1.   An imaging apparatus comprising the imaging lens according to claim 1.