Imaging lens, recognition device, and information processing device

Abstract

Provided are an imaging lens, an identification device, and an information processing device which are capable of having a wide angle of view, and which are bright, high-performance, and compact. An imaging lens (100) is provided with first to fourth lenses (L1-L4) and an aperture stop (S) closest to the object side, which are arranged in this order from the object side to the image side. The first lens (L1) is a positive lens having a convex surface facing the object side, the second lens (L2) is a negative lens having an inflection point on at least one surface and having a small deviation ratio, the third lens (L3) is a positive lens having a convex surface facing the image surface side and having an inflection point at a lens peripheral portion on the object side surface, the fourth lens (L4) is a concave surface on the image surface side, and the fifth lens (L5) is a convex surface facing the object side. And a negative lens having an inflection point at a peripheral portion thereof.

Description

Technical Field

[0001] The present disclosure relates to a photographing lens, an identification device, and an information processing device. Background Art

[0002] In recent years, in society, in order to prevent data leakage from information terminals, the need for information security has increased. As a countermeasure for users, in order to prevent the outflow of information from information terminals or to restrict the use of information terminals, passwords are made more complex. However, in conventional information security countermeasures, if passwords are made more complex, it becomes difficult for users to use them, so security enhancements of devices such as fingerprint recognition or face recognition using near-infrared rays are also carried out simultaneously.

[0003] Moreover, in order to establish identification higher than motion sensing, high pixelization of these devices for near-infrared rays is also carried out.

[0004] In addition, in recent years, a face recognition device of a user has been mounted on a laptop computer. Therefore, in the identification device, miniaturization considering portability has also been achieved. The identification device required by the market is mainly a device that not only has face authentication at the time of login but also has functions such as motion sensing. There is a known technology in which not only the lens of an infrared camera is made highly performant but also the number of lenses is reduced (for example, refer to Patent Document 1 and Patent Document 2).

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-018162;

[0006] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2016-139093.

[0007] However, in recent years, as an infrared camera, there has appeared a camera capable of photographing a near-infrared band with a main wavelength of 850 nm or 940 nm, and a camera capable of photographing a monochromatic (visible light) wavelength characteristic of 450 nm in addition to the near-infrared band. Therefore, there is a desire for an optical performance that satisfies not only the near-infrared band but also the visible light wavelength band, and a photographing lens that is smaller than conventional infrared photographing lenses, has a wide field of view angle, is bright, and has high performance. Summary of the Invention

[0008] The present disclosure has been made in view of the above, and an object thereof is to provide a photographing lens, a photographing device, and an information processing device having a wide field of view angle, being bright, having high performance, and being small.

[0009] To solve the above problems and achieve the object, the imaging lens according to the first aspect of the present disclosure includes: a first lens to a fourth lens, arranged in order from the object side; and an aperture stop, arranged closest to the object side. The first lens is a positive lens with a convex surface facing the object side, the second lens is a negative lens having an inflection point on at least one surface and a relatively small deviation ratio, the third lens is a positive lens with a convex surface facing the image side and having an inflection point at the lens peripheral portion on the object side, and the fourth lens is a negative lens with a concave surface on the image side and having an inflection point at the peripheral portion. When the focal length of the first lens is set as f1, the focal length of the fourth lens is set as f4, and the focal length of the entire optical system is set as f, the conditions (1) and (2) are satisfied:

[0010] 0.50 < |f / f1| < 1.40 ··· (1)

[0011] 0.40 < |f4 / f1| < 2.0 ··· (2).

[0012] In addition, the recognition device according to the second aspect of the present disclosure includes the above imaging lens and a single imaging element that receives the image formed by the above imaging lens and generates an imaging signal.

[0013] In addition, the information processing device according to the third aspect of the present disclosure includes the above imaging device and a display unit that displays an image corresponding to the above imaging signal generated by the above imaging device.

[0014] According to the present disclosure, there is an effect that an imaging lens with a wide field of view angle, bright, high-performance and small size can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram showing the lens configuration of the imaging lens according to Embodiment 1 of the present disclosure.

[0016] Figure 2A It is an aberration diagram of the imaging lens according to Embodiment 1 of the present disclosure.

[0017] Figure 2B It is the MTF of the imaging lens according to Embodiment 1 of the present disclosure.

[0018] Figure 2C It is the distortion grid of the imaging lens according to Embodiment 1 of the present disclosure.

[0019] Figure 3 It is a diagram showing the lens configuration of the imaging lens according to Embodiment 2 of the present disclosure.

[0020] Figure 4A It is an aberration diagram of the imaging lens according to Embodiment 2 of the present disclosure.

[0021] Figure 4Bis the MTF of the imaging lens according to Embodiment 2 of the present disclosure.

[0022] Figure 4C is the distortion grid of the imaging lens according to Embodiment 2 of the present disclosure.

[0023] Figure 5 is a diagram showing the lens configuration of the imaging lens according to Embodiment 3 of the present disclosure.

[0024] Figure 6A is the aberration diagram of the imaging lens according to Embodiment 3 of the present disclosure.

[0025] Figure 6B is the MTF of the imaging lens according to Embodiment 3 of the present disclosure.

[0026] Figure 6C is the distortion grid of the imaging lens according to Embodiment 3 of the present disclosure.

[0027] Figure 7 is a diagram showing the lens configuration of the imaging lens according to Embodiment 4 of the present disclosure.

[0028] Figure 8A is the aberration diagram of the imaging lens according to Embodiment 4 of the present disclosure.

[0029] Figure 8B is the MTF of the imaging lens according to Embodiment 4 of the present disclosure.

[0030] Figure 8C is the distortion grid of the imaging lens according to Embodiment 4 of the present disclosure.

[0031] Figure 9 is a diagram showing the lens configuration of the imaging lens according to Embodiment 5 of the present disclosure.

[0032] Figure 10A is the aberration diagram of the imaging lens according to Embodiment 5 of the present disclosure.

[0033] Figure 10B is the MTF of the imaging lens according to Embodiment 5 of the present disclosure.

[0034] Figure 10C is the distortion grid of the imaging lens according to Embodiment 5 of the present disclosure.

[0035] Figure 11 is a diagram showing the lens configuration of the imaging lens according to Embodiment 6 of the present disclosure.

[0036] Figure 12A is the aberration diagram of the imaging lens according to Embodiment 6 of the present disclosure.

[0037] Figure 12B is the MTF of the imaging lens according to Embodiment 6 of the present disclosure.

[0038] Figure 12C It is the distortion grid of the photographing lens according to Embodiment 6 of the present disclosure.

[0039] Figure 13 It is the reflectance characteristic of an example of the near-infrared region corresponding coating on the lens surfaces of the first lens to the fourth lens of the photographing lens according to Embodiments 1 to 6 of the present disclosure.

[0040] Figure 14 It is a diagram showing a schematic configuration of an information processing apparatus including an identification apparatus having the photographing lens according to each embodiment of the present disclosure.

[0041] Figure 15 It shows Figure 14 a schematic configuration of the identification apparatus.

[0042] Figure 16 It is a block diagram showing a functional configuration of an information processing apparatus including an identification apparatus having the photographing lens according to each embodiment of the present disclosure.

[0043] 30... Information processing apparatus, 31... Identification apparatus, 100... Photographing lens, L1... First lens, L2... Second lens, L3... Third lens, L4... Fourth lens, S... Aperture stop, CG... Glass cover. Detailed implementation mode

[0044] Hereinafter, the photographing lens, the identification apparatus, and the information processing apparatus of the present disclosure will be described with reference to the drawings. In addition, the present disclosure is not limited by the following embodiments. In the following description, the respective drawings referred to schematically show the shape, size, and positional relationship only to the extent that the content of the present disclosure can be understood. That is, the present disclosure is not limited only to the shape, size, and positional relationship illustrated in the respective drawings. In addition, the same reference numerals are given to the same parts and detailed description thereof is omitted.

[0045] [Embodiment]

[0046] Figure 1 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 are cross-sectional views showing the lens configurations of the photographing lenses according to Embodiments 1 to 6, respectively. In each cross-sectional view, the left side is the object side (front), and the right side is the image side (rear).

[0047] The photographing lens 100 of each embodiment includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged in order from the object side to the image side. In addition, the photographing lens 100 includes an aperture stop S (STOP) arranged on the object side compared to the first lens L1.

[0048] In addition, in Figure 1 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 , the additional reference numerals 1 to 9 attached to any one of the first lens L1 to the fourth lens L4 and the aperture stop S represent the surfaces of the respective lenses or the aperture stop. Hereinafter, these surfaces will be referred to as surfaces 1 to 9 in order from the object side toward the image side. Surface 1 is the surface of the aperture stop S. And, in Figure 1 , Figure 3 , Figure 5 , Figure 7 , Figure 9 and Figure 11 , the reference numeral CG represents an infrared parallel plate equivalent to a component composed of at least one or more of the cover glass of the single imaging element and various filters. The incident side surface of the infrared parallel plate CG is referred to as surface 10, and the image side surface is referred to as surface 11.

[0049] The imaging lens 100 is arranged with an aperture stop, a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 in order from the closest to the object side. In the imaging lens 100, the first lens L1 is composed of a positive lens, the second lens L2 is composed of a negative lens having a negative power, the third lens L3 is composed of a positive lens, and the fourth lens is composed of a negative lens, and the positive and negative lenses are arranged in sequence. In this configuration, it is possible to facilitate the correction of spherical aberration and coma aberration, and good telecentricity can also be achieved on the image side.

[0050] The first lens L1 is a positive lens with the convex surface facing the object side, and it can be a meniscus lens or a biconvex lens. As in the embodiments described later, the material of the first lens L1 can be either plastic or glass.

[0051] The second lens L2 is composed of a negative lens having at least one inflection point on one surface and a relatively small deviation ratio, but it can also have inflection points on both surfaces. Here, the inflection point on one surface refers to a region from the optical axis to the outer edge at a position of six-tenths to eight-tenths of the diameter of the second lens L2 on the side of surface 4 or surface 5.

[0052] The third lens L3 is composed of a positive lens with the convex surface facing the image side and having an inflection point in the lens peripheral portion of the surface on the object side. Here, the inflection point in the lens peripheral portion refers to a region from the optical axis to the outer edge at a position of eight-tenths to nine-tenths of the diameter of the third lens L3 on the side of surface 7.

[0053] The fourth lens L4 is a negative lens having a concave surface on the image side and an inflection point at the periphery. The inflection point at the periphery refers to a region at a position of 6 / 10 to 8 / 10 from the optical axis toward the outer edge relative to the aperture of the fourth lens L4 on the surface 8 side.

[0054] The first lens L1 to the fourth lens L4 thus constructed may have an aspherical surface or a spherical surface, but the second lens L2, the third lens L3, and the fourth lens L4 are all aspherical lenses, each having an aspherical shape feature. Furthermore, by making the second lens L2, the third lens L3, and the fourth lens L4 have an inflection point, it is possible to highly correct aberrations while making the thickness (total length) of the photographing lens 100 in the light direction thin.

[0055] In addition, as for the material of the lens, as shown in the embodiment, an optical plastic material or a glass material is used.

[0056] Figures 2A - 2C , Figures 4A - 4C , Figures 6A - 6C , Figures 8A - 8C , Figures 10A - 10C as well as Figures 12A - 12C They are respectively the longitudinal aberration diagram, MTF, and distortion grid of the shooting lens 100 of embodiments 1 to 6. In the spherical aberration diagram, the spherical aberration amounts for the d-line (yellow: wavelength 587.6nm), g-line (blue: wavelength 435.8nm), C-line (red: 653.3nm), and near-infrared ray I940 (940nm) are shown. In addition, in the astigmatism diagram, the solid line S represents the astigmatism amount on the sagittal image plane, and the dotted line T represents the astigmatism amount on the tangential image plane. And, in the distortion aberration diagram, only the distortion aberration amount for the d-line is shown. In addition, Angle (deg) represents the shooting half field angle (°). In MTF, when the frequency is 1 / 4Ny and 1 / 2Ny, the five-dot dash line represents the MTF of the sagittal image plane at 1 / 4Ny, the thick dashed line represents the MTF of the tangential image plane at 1 / 4Ny, the three-dot dash line represents the MTF of the sagittal image plane at 1 / 2Ny, and the thin dashed line represents the MTF of the tangential image plane at 1 / 2Ny. In addition, regarding the distortion grid, the thin line represents the paraxial FOV (ideal) grid, and the thick line represents the actual FOV (real) grid.

[0057] Next, the conditions of the imaging lens 100 in each embodiment will be described.

[0058] The imaging lens 100 of each embodiment satisfies the following conditions (1) and (2) when the focal length of the first lens L1 is f1, the focal length of the fourth lens L4 is f4, and the focal length of the entire optical system is f.

[0059] 0.50 < |f / f1| < 1.40 ··· (1)

[0060] 0.40 < |f4 / f1| < 2.0 ··· (2)

[0061] Condition (1) is a conditional expression related to the overall focal length of the photographing lens 100 and the lens power of the first lens L1.

[0062] When f / f1 is below the lower limit of condition (1), there is a tendency for the overall focal length to become shorter. Therefore, it is advantageous for a wider angle of view, but since astigmatism tends to become excessive and distortion aberration also tends to increase, it is difficult to achieve the desired performance. In addition, when f / f1 is above the upper limit of condition (1), there is a tendency to improve spherical aberration and astigmatism, but since the field angle tends to become narrow, the performance desired by the present invention cannot be achieved, so it is not preferred. Therefore, by satisfying condition (1), the photographing lens 100 can achieve a balance between short form (low profile) and high performance.

[0063] Condition (2) is a conditional expression related to the positive power of the first lens L1 and the negative power of the fourth lens L4.

[0064] When |f4 / f1| is below the lower limit of condition (2), astigmatism tends to be excessive and spherical aberration is also generated relatively largely, so it is difficult to achieve the desired performance. In addition, when |f4 / f1| is above the upper limit of condition (2), spherical aberration tends to be too small, so the balance with astigmatism is broken and it is difficult to achieve the desired performance.

[0065] That is, by satisfying condition (1) and condition (2), the photographing lens 100 can achieve a balance between spherical aberration and astigmatism, and realize a bright, high-performance and small (compact) photographing lens 100. Here, small means reducing the thickness by shortening the overall length of the photographing lens 100 in the optical axis direction and reducing the aperture of the photographing lens 100.

[0066] In addition, when the refractive index of the material of the first lens L1 with respect to the d-line is set to N1 and the refractive index of the material of the fourth lens L4 with respect to the d-line is set to N4 in the photographing lens 100 of each embodiment, condition (3) is satisfied.

[0067] N1 < N4 ··· (3)

[0068] Condition (3) is a condition that defines the relationship between the refractive index N1 of the material of the first lens L1 and the refractive index N4 of the material of the fourth lens L4.

[0069] The first lens L1 is a positive lens. Additionally, the fourth lens L4 is a negative lens. In the embodiments of the present disclosure, in order to make the chromatic aberration appropriate and balance miniaturization, it is formed of a material with a refractive index such that the refractive index N1 of the first lens L1 is smaller than the refractive index N4 of the fourth lens L4, and it satisfies condition (3), thereby enabling the desired good chromatic aberration to be achieved.

[0070] Additionally, when the refractive index of the material of the first lens L1 with respect to the d-line is set as N1, the imaging lens 100 of each embodiment satisfies condition (4).

[0071] 1.49 < N1 < 1.55 ··· (4)

[0072] When the refractive index N1 is below the lower limit of condition (4), the optical performance is further improved, but the cost becomes high, so it is not preferred. Additionally, when the refractive index N1 is above the upper limit of condition (4), the optical performance affects the chromatic aberration, so it is not preferred. Thus, by making the imaging lens 100 satisfy condition (4), a balance between cost and chromatic aberration is achieved, and a bright, high-performance, and small (compact) imaging lens 100 can be realized.

[0073] Additionally, when the refractive index of the material of the fourth lens L4 with respect to the d-line is set as N4, the imaging lens 100 of each embodiment satisfies condition (5).

[0074] 1.63 < N4 < 1.67 ··· (5)

[0075] When the refractive index N4 is below the lower limit of condition (5), or when the refractive index N4 is above the upper limit of condition (5), the balance of chromatic aberration is broken. Considering the balance between cost and chromatic aberration, by satisfying condition (5), a bright, high-performance, and small imaging lens 100 can be realized.

[0076] Additionally, when the focal length of the entire optical system (imaging lens 100) is set as f and the overall length of the optical system (the long side direction of the imaging lens 100) is set as OAL, the imaging lens 100 of each embodiment satisfies condition (6).

[0077] 0.60 < f / OAL < 0.90 ··· (6)

[0078] Condition (6) is a condition for achieving the balance between the focal length f of the entire optical system and the overall length OAL.

[0079] In the photographing lens 100 of each embodiment, when f / OAL is below the lower limit of condition (6), further wide-angleization can be achieved, but there is a tendency for the front spherical diameter to increase, so there is a concern about an increase in size. On the other hand, when f / OAL is above the upper limit of condition (6), the overall length of the optical system becomes smaller, but it is difficult to widen the field angle. The photographing lens 100 that satisfies condition (6) can achieve miniaturization of size and wide-angleization of the field angle.

[0080] In addition, the photographing lens 100 of each embodiment satisfies condition (7) when the overall length of the optical system is set to OAL and the effective optical diameter of the lens (first lens L1) disposed closest to the object side is set to EfD1.

[0081] 2.2 < OAL / EfD1 < 3.2 ··· (7)

[0082] Condition (7) is a condition for achieving a balance between the overall length of the lens and the front spherical diameter of the lens (first lens L1).

[0083] When OAL / EfD1 is below the lower limit of condition (7), miniaturization of the optical system (shortening in the optical axis direction) is achieved, but it is difficult to achieve a wide field angle. When OAL / EfD1 is above the upper limit of condition (7), the performance of the optical system is improved, but it is difficult to achieve miniaturization (shortening in the optical axis direction). The photographing lens 100 can achieve miniaturization (shortening in the optical axis direction) and high performance by satisfying condition (7).

[0084] In addition, the photographing lens of each embodiment satisfies condition (8) when the exit pupil position is set to EXP and the image height is set to IH.

[0085] −1.3 < EXP / IH < −0.9 ··· (8)

[0086] Condition (8) is a condition for optimizing the light incident angle on the image plane.

[0087] When EXP / IH is below the lower limit of condition (8), there is a tendency for the light incident angle to become lower, but there is a tendency for it to be difficult to shorten the overall length of the optical system to miniaturize it. On the other hand, when EXP / IH is above the upper limit of condition (8), there is a tendency for the light incident angle to become higher. Therefore, the photographing lens 100 can achieve miniaturization by satisfying condition (8).

[0088] In addition, the photographing lens of each embodiment satisfies condition (9) when the focal length of the first lens L1 is set to f1 and the focal length of the second lens L2 is set to f2.

[0089] 0.40 < |f1 / f2| < 0.71 ··· (9)

[0090] Condition (9) is a condition related to the balance of the focal lengths of the first lens L1 and the second lens L2.

[0091] When |f1 / f2| is below the lower limit of condition (9), the lens power of f2 becomes weaker relative to f1, so it is easy for spherical aberration and distortion aberration to become insufficiently corrected, making it difficult to achieve high performance. Additionally, when |f1 / f2| is above the upper limit of condition (9), astigmatism tends to increase, so it is not preferred. Therefore, the imaging lens 100 can achieve high performance by satisfying condition (9).

[0092] In addition, when the imaging lens 100 of each embodiment sets the focal length of the first lens L1 as f1 and the focal length of the third lens L3 as f3, it satisfies condition (10).

[0093] 0.3 < f3 / f1 < 2.8 ··· (10)

[0094] Condition (10) is a conditional expression related to the positive power of the first lens L1 and the positive power of the third lens L3.

[0095] When f3 / f1 is below the lower limit of condition (10), astigmatism tends to be excessive, and distortion aberration and coma aberration are also generated relatively large, making it difficult to achieve the desired performance. Additionally, when f3 / f1 is above the upper limit of condition (10), spherical aberration tends to be too small, so the balance with astigmatism is broken, making it difficult to achieve the desired performance.

[0096] In addition, when the imaging lens 100 of each embodiment sets the focal length of the third lens L3 as f3 and the focal length of the fourth lens L4 as f4, it satisfies condition (11).

[0097] 0.5 < |f3 / f4| < 2.0 ··· (11)

[0098] Condition (11) is a conditional expression related to the lens power of the third lens L3 and the lens power of the fourth lens L4.

[0099] When f3 / f4 is below the lower limit of condition (11), astigmatism tends to be excessive, and distortion aberration also tends to increase, so it is difficult to achieve the desired performance. Additionally, when f3 / f4 is above the upper limit of condition (11), the overall focal length becomes larger, tending to have a narrow field angle, so there is a tendency to improve astigmatism and distortion aberration, but since spherical aberration tends to increase, it is difficult to achieve the desired performance. Therefore, the imaging lens 100 can achieve a balance between short form (low profile) and high performance by satisfying condition (11).

[0100] In addition, the first lens L1 to the fourth lens L4 of the imaging lens 100 of each embodiment each have a near-infrared region corresponding coating (laminated coating) covering the lens surface. The near-infrared region corresponding coating corresponding to near-infrared rays transmits light in the frequency band of 450 to 940 nm, and the reflectance in the frequency band of at least 850 nm to 940 nm in the near-infrared region is 2% or less.

[0101] Figure 13 This is the reflectance characteristic of an example of the near-infrared region corresponding coating implemented on at least one surface or more of the lens surfaces of the first lens L1 to the fourth lens L4 of the imaging lens 100 in Embodiments 1 to 6. In Figure 13 it, the horizontal axis represents the wavelength band, and the vertical axis represents the reflectance. In Figure 13 it, the curve K1 represents the reflectance characteristic of a general multi-coating, and the curve K2 represents the reflectance characteristic of the near-infrared region corresponding coating (near-infrared region corresponding multi-coating).

[0102] On the lens surfaces of the first lens L1 to the fourth lens L4 of the imaging lens 100, a near-infrared region corresponding coating (solid line) having the reflectance characteristic shown by the curve K1 of Figure 13 is covered (coated or laminated) on the lens. By covering (coating or laminating) such a near-infrared region corresponding coating on the lens, an imaging lens corresponding to near-infrared rays and an imaging device including the imaging lens can be realized. In addition, the near-infrared region corresponding coating is attached and formed on the lens surfaces of the first lens L1 to the fourth lens L4 by using a known technique. Of course, a thin sheet of the near-infrared region corresponding coating may be pasted on the lens surfaces of the first lens L1 to the fourth lens L4.

[0103] The imaging lens 100 of the embodiment of the present disclosure has a four-lens structure, and the lens surfaces are eight surfaces. The transmittance of the imaging lens 100 is also an important factor for an imaging device and an identification device.

[0104] Here, if the transmittance of the four-lens structure imaging lens 100 in Embodiments 1 to 6 of the present disclosure at a near-infrared ray of 940 nm is simply calculated, in the case of the four-lens structure, since there are eight reflecting surfaces, it becomes the eighth power of (1 - reflectance). Thus, if the reflectance at 940 nm is 33%, then in the case of the general multi-coating (dotted line) shown by the curve K1 of Figure 13 covered (coated), the transmittance at 940 nm is transmittance at 940 nm = (1 - 0.33) ^ 8 = 4.1%, which is not preferable.

[0105] On the other hand, as Figure 13As shown by the curve K2, when the transmittance at 940 nm for the multi-coating corresponding to the near-infrared region (curve K2) was also calculated, when the reflectance at 940 nm was 2% (refer to the straight line H1), the transmittance at 940 nm = (1 - 0.02)^8 = 85.1%, enabling good transmittance, and it is suitable as the photographing lens 100 of a photographing device capable of performing near-infrared photographing.

[0106] Thus, the photographing lenses 100 of the respective Embodiments 1 to 6 each cover the first lens L1 to the fourth lens L4 with a multi-coating corresponding to the near-infrared region corresponding to the near-infrared on the lens surface, transmit light in the frequency band of 450 to 940 nm, and furthermore, the reflectance in the frequency band of at least 850 to 940 nm in the near-infrared region is 2% or less. As Figure 13 shown by the curve K2, in the multi-coating corresponding to the near-infrared region, the reflectance in the frequency band of the visible light region of 450 to 650 nm is also low, but considering the sensor characteristics (image sensor characteristics) of the near-infrared photographing device, the reflectance in the visible light region may also be 2% or more.

[0107] In addition, regarding the glass covers described in the respective Embodiments 1 to 6, they are also covered (coated) Figure 13 with an infrared multi-coating having a reflectance in the frequency band of nearly 850 to 940 nm of 2% or less, corresponding to the near-infrared photographing device.

[0108] 〔Photographing Device〕

[0109] Next, an embodiment of an information processing device (PC) having an identification device using the photographing lens 100 of each embodiment as a photographing optical system will be described.

[0110] Figure 14 is a diagram showing a schematic configuration of an information processing device having an identification device having the photographing lens 100 of each embodiment. Figure 15 is showing Figure 14 the schematic configuration of the identification device. Figure 16 is a block diagram showing a functional configuration of an information processing device having an identification device having the photographing lens of each embodiment.

[0111] Figures 14 - 16 The information processing device 30 shown at least includes an identification device 31, a signal processing unit 32, an image processing unit 33, a control unit 34, a display unit 35, a storage unit 36, a communication unit 37, an input unit 38, a voice input / output unit 39, and a photographing device 40.

[0112] The identification device 31, under the control of the control unit 34, generates a photographing signal by photographing a prescribed field-of-view area, and outputs the photographing signal to the signal processing unit 32. The identification device 31, asFigure 15 As shown, it has at least a cover 311, the imaging lens 100 of each embodiment, and a single imaging element 312. The recognition device 31 is arranged on the front side of the information processing device 30. Specifically, the recognition device 31 is arranged at a position juxtaposed with the imaging device 40.

[0113] The cover 311 is constituted by a glass cover or the like which is a component for preventing dirt and dust on the imaging lens 100.

[0114] The single imaging element 312 receives the image of the object to be imaged by the imaging lens 100, and generates an imaging signal through photoelectric conversion. The single imaging element 312 is constituted by a CCD sensor, a CMOS sensor, or the like. Preferably, the single imaging element 312 arranges effective pixels of more than 300,000 pixels, that is, VGA or higher (640×480 or higher) in a two-dimensional matrix shape.

[0115] Under the control of the control unit 34, the signal processing unit 32 performs A / D conversion processing or the like on the imaging signal input from the single imaging element 312 to convert it into a digital imaging signal and outputs it to the image processing unit 33. For example, the signal processing unit 32 is constituted by a DSP (Digital Signal Processor). In addition, under the control of the control unit 34, the signal processing unit 32 performs A / D conversion processing or the like on the imaging signal input from the imaging device 40 to convert it into a digital imaging signal and outputs it to the image processing unit 33.

[0116] Under the control of the control unit 34, the image processing unit 33 performs prescribed image processing on the digital imaging signal input from the signal processing unit 32 and outputs it to the display unit 35 or the storage unit 36. For example, the image processing unit 33 is constituted by a GPU (Graphics Processing Unit).

[0117] The control unit 34 controls each unit constituting the information processing device 30. The control unit 34 includes a processor and a memory. The processor is constituted by a CPU or an FPGA (Field-Programmable Gate Array). The memory is constituted by a RAM (Random Access Memory) or a ROM (Read Only Memory).

[0118] Under the control of the control unit 34, the display unit 35 displays the video during imaging on which the image processing unit 33 has performed image processing, the captured image, the still image corresponding to the image signal stored in the storage unit 36, and various information related to the information processing device 30.

[0119] The storage unit 36 stores various information related to the information processing device 30, programs executed by the information processing device 30, and shooting signals (RAW data or JPEG data) shot by the shooting device 40. The storage unit 36 is constituted by, for example, a flash memory, an SSD (Solid State Drive), an HDD (Hard Disk Drive), and a memory card.

[0120] Under the control of the control unit 34, the communication unit 37 transmits the shooting signal shot by the shooting device 40 to the outside via a network according to a prescribed communication standard, and receives various information input from the outside. The communication unit 37 uses, for example, communication standards based on 3GPP (registered trademark), 4G, LTE, 5G, WiMAX, and Wi-Fi (registered trademark) established by IEEE.

[0121] The input unit 38 accepts operation inputs from the user and outputs operation information corresponding to the accepted operations to the control unit 34. The input unit 38 is constituted by, for example, a touch panel, a keyboard, and a mouse.

[0122] Under the control of the control unit 34, the audio input / output unit 39 accepts the input of external sound, converts it into an audio signal, and outputs it to the storage unit 36 or the communication unit 37. Further, under the control of the control unit 34, the audio input / output unit 39 converts the audio signal input from the storage unit 36 or the communication unit 37 and outputs it to the outside. The audio input / output unit 39 is constituted by, for example, a microphone and a speaker.

[0123] Under the control of the control unit 34, the shooting device 40 generates a shooting signal by shooting a prescribed field of view area, and outputs the shooting signal to the signal processing unit 32. The shooting device 40 is disposed on the front side of the information processing device 30. Specifically, the shooting device 40 is disposed at a position where the user of the information processing device 30 can be shot. Of course, the shooting device 40 can appropriately change the disposed position according to the shape, size, and usage mode of the information processing device 30.

[0124] The information processing device 30 configured as described above can perform face recognition and the like with a high image quality of 300,000 pixels or more with an external device using the recognition device 31 having a shooting lens 100, and can perform communication based on Web communication via a network.

[0125] In addition, in the embodiment, a PC is described as an example of the information processing device 30, but the recognition device 31 can be applied to, for example, a shooting device of a tablet terminal, a mobile phone, or the like. Of course, the recognition device 31 can also be applied to a Web camera or the like that can communicate with a PC or the like by wire or wirelessly.

[0126] According to the embodiments described above, an information processing apparatus with a wide-angle field of view, which is bright, high-performance, and small-sized, can be realized.

[0127] In addition, according to the embodiment, a half field of view of approximately 38.5° can be achieved with four lenses.

[0128] In addition, according to the embodiment, since the photographing lens 100 can achieve a wide-angle field of view, has a small F-number, is high-performance, and is small-sized, in the case of video shooting, it can cope with shooting in various environments such as a dark environment and high-speed shooting speed.

[0129] In addition, according to the embodiment, since a wide-angle field of view, a bright, high-performance, and small-sized photographing lens can be realized, the matching between the incident angle in the light-receiving element of the single photographing element and the light incident on the light-receiving surface can be improved on the image side.

[0130] In addition, according to the embodiment, since a photographing lens with a bright, high-performance, and small-sized half field of view of approximately 38.5° can be formed by four lenses, for example, it can be used as a single-focus lens for mobile phones such as smartphones and PCs. Therefore, in the case of video shooting requiring a high pixel count of VGA or higher (640×480 or higher), compared with conventional photographing lenses, sufficient aberration correction can be performed, and the required performance can be satisfied.

[0131] In addition, according to the embodiment, since a photographing lens with a bright, high-performance, and small-sized half field of view of approximately 38.5° can be formed by four lenses, the overall length in the optical axis direction of the photographing lens 100 can be shortened, and the lens diameter can also be reduced, enabling miniaturization. As a result, the refractive power of the miniaturized lens becomes smaller, and the influence of manufacturing errors and assembly errors can be reduced. As a result, productivity can be improved, and production costs can be suppressed.

[0132] In addition, by appropriately combining a plurality of constituent elements disclosed in the information processing apparatus according to the embodiments of the present disclosure, various inventions can be formed. For example, several constituent elements may be deleted from all the constituent elements described in the information processing apparatus according to the embodiments of the present disclosure above. Also, the constituent elements described in the information processing apparatus according to the embodiments of the present disclosure above may be appropriately combined.

[0133] In addition, in the information processing apparatus according to the embodiments of the present disclosure, the above-mentioned "section" can be replaced with "unit" or "circuit", etc. For example, the control section can be replaced with a control unit or a control circuit.

[0134] In addition, a program executed by the information processing apparatus according to an embodiment of the present disclosure is recorded as file data in a format that can be installed or a format that can be executed on a computer-readable recording medium such as a CD-ROM, a floppy disk (FD), a CD-R, a DVD (Digital Versatile Disk), a USB medium, or a flash memory and provided.

[0135] In addition, a program executed by the information processing apparatus according to an embodiment of the present disclosure may also be configured to be stored on a computer connected to a network such as the Internet and provided by downloading it via the network.

[0136]

Embodiment

[0137] Hereinafter, Embodiments 1 to 6 of the photographing lens 100 corresponding to Embodiments 1 to 6 are shown.

[0138] The meanings of the symbols in each embodiment are as follows.

[0139] f: Focal length of the entire lens system

[0140] fl: Focal length of each lens

[0141] FNo.: Numerical aperture (F-number)

[0142] R: Curvature radius of the surface

[0143] D: Surface interval

[0144] Nd: Refractive index for d-line

[0145] Vd: Abbe number for d-line

[0146] SD: Effective radius

[0147] When the depth in the optical axis direction is set to X, the height from the optical axis is set to H, the paraxial curvature radius is set to R, the conic constant is set to k, and the high-order aspherical coefficient is set to CN (N is an even number of 4 or more), the aspherical surface is represented by the following well-known formula (15) using the aspherical coefficient.

[0148] X = (H 2 / R) / [1 + {1 - k(H / r) 2} 1 / 2

[0149] + Σ N＝4:even CNH N ···(15)

[0150] Here, Σ N≧4:even means the sum for even numbers of N of 4 or more.

[0151] [Embodiment 1]

[0152] f = 1.4 mm, FNo. = 2.0, HFOV = 40°

[0153] The data of Example 1 are shown in Table 1.

[0154]

[0155] The data of the aspherical surface are as follows.

[0156]

Table 2

[0157]

[0158] In the above description of the aspherical surface, for example, "2.1143.E-02" means "2.1143 * 10 －2 ". The same applies to the following other examples.

[0159] The parameter values of each condition are as follows. In addition, EP: entrance pupil position is also described in Table 3.

[0160]

Table 3

[0161] Item Value f 1.40 Fno 2.00 OAL 2.12 IH 1.18 EfD1 0.70 Half FOV 40.15 EP 0.00 EXP -1.46 f12 2.72 f3 -5.37 f4 0.85 f5 -1.19 N1 1.5365 N2 1.6328 N3 1.5365 N4 1.6328

[0162] In this table, in addition to conditional expressions (1) to (11), (12) to (14) are also described for reference.

[0163]

Table 4

[0164] Condition formula Value Lower limit Upper limit (1) f / f1 0.512 0.5 1.4 (2) |f4 / f1| 0.435 0.4 2.0 (3) N1 < N4 Refer to Table 3 (4) N1 1.536 1.49 1.55 (5) N4 1.633 1.63 1.67 (6) f / OAL 0.658 0.6 0.9 (7) OAL / EfD1 3.038 2.2 3.2 (8) EXP / IH -1.237 -1.3 -0.9 (9) |f1 / f2| 0.507 0.40 0.71 (10) f3 / f1 0.314 0.30 2.80 (11) |f3 / f4| 0.721 0.5 2.0 (12) |f4 / f2| 0.221 0.20 1.30 (13) |f3 / f2| 0.159 0.10 1.50 (14) OAL / 2 * IH 0.898 0.70 1.00

[0165] In addition, the meanings of the conditional expressions (12) to (14) are as follows.

[0166] 0.2 < |f4 / f2| < 1.3 ··· (12)

[0167] Regarding conditional expression (12), f2 represents the focal length of the second lens L2, f4 represents the focal length of the fourth lens L4, and it is a condition for the balance of the focal lengths of the second lens L2 and the fourth lens L4. Within the range of conditional expression (12), high performance can be achieved. When it is below the lower limit of the conditional expression, astigmatism becomes larger, and when it is above the upper limit of conditional expression (12), spherical aberration becomes larger. Therefore, it is preferably within the range that satisfies the conditional expression.

[0168] 0.10 < |f3 / f2| < 1.5 ··· (13)

[0169] Regarding conditional expression (13), f2 represents the focal length of the second lens L2, and f3 represents the focal length of the third lens L3, which is the condition for the balance of the focal lengths of the second lens L2 and the third lens L3. Within the range of conditional expression (13), high performance can be achieved. When it is below the lower limit of the conditional expression, astigmatism increases, and when it is above the upper limit of conditional expression (13), spherical aberration increases. Therefore, it is preferably within the range that satisfies the conditional expression.

[0170] The feature of the present invention is that the power of the second lens L2 is weaker compared to the power of other lenses. However, in the present invention, by disposing a positive or negative lens with relatively weaker power compared to other lenses in the second lens, astigmatism, spherical aberration, and distortion aberration can be effectively corrected.

[0171] 0.7 < OAL / 2 * IH < 1.0 ··· (14)

[0172] Regarding conditional expression (14), OAL represents the overall optical length, and IH represents the image height, that is, the image circle of the so-called optical system, showing the ratio of the overall optical length to the image circle. As in conditional expression (14), the overall optical length is 0.7 to 1.0 with respect to the image circle, and it can be seen that the photographing lens of the present invention is low-profile.

[0173] In addition, regarding these conditional expressions, they are also applied after Example 2.

[0174] In addition, aspherical surfaces are used in the first lens L1 to the fourth lens L4 in each embodiment, and aberrations are well corrected by the aspherical surfaces.

[0175] The aberration diagrams, MTF, and distortion grids related to the above-mentioned Example 1 are as Figures 2A - 2C shown, but as is clear from each figure, the performance is good.

[0176] [Example 2]

[0177] f = 1.5 mm, FNo. = 2.0, HFOV = 38.5°

[0178] The data of Example 2 are shown in Table 5.

[0179]

Table 5

[0180]

[0181] The data of the aspherical surfaces are as follows.

[0182]

Table 6

[0183]

[0184] The values of the parameters of each condition are as follows.

[0185]

Table 7

[0186] Item Value f 1.47 Fno 2.00 OAL 2.12 IH 1.18 EfD1 0.74 Half FOV 38.45 EP 0.00 EXP -1.40 f12 2.37 f3 -5.54 f4 1.16 f5 -1.75 N1 1.5350 N2 1.6652 N3 1.5350 N4 1.6652

[0187]

Table 8

[0188] Condition formula Value Lower limit Upper limit (1) f / f1 0.622 0.5 1.4 (2) |f4 / f1| 0.737 0.4 2.0 (3) N1 < N4 Refer to Table 7 (4) N1 1.535 1.49 1.55 (5) N4 1.665 1.63 1.67 (6) f / OAL 0.694 0.6 0.9 (7) OAL / EfD1 2.881 2.2 3.2 (8) EXP / 1H -1.182 -1.3 -0.9 (9) |f1 / f2| 0.427 0.40 0.71 (10) f3 / f1 0.492 0.30 2.80 (11) |f3 / f4| 0.667 0.5 2.0 (12) |f4 / f2| 0.315 0.20 1.30 (13) |f3 / f2| 0.210 0.10 1.50 (14) OAL / 2 * IH 0.898 0.70 1.00

[0189] These aberration diagrams, MTF, and distortion grids are as Figures 4A - 4C shown, but as is clear from each diagram, the performance is good.

[0190] [Example 3]

[0191] f = 1.5 mm, FNo. = 2.0, HFOV = 38.5°

[0192] The data of Example 3 are shown in Table 9.

[0193]

Table 9

[0194]

[0195] The data of the aspherical surface are as follows.

[0196]

Table 10

[0197]

[0198] The parameter values for each condition are as follows.

[0199]

Table 11

[0200] Item Value f 1.46 Fno 2.00 OAL 1.90 IH 118 EfD1 0.73 Half FOV 38.45 EP 0.00 EXP -1.17 f12 1.26 f3 -1.97 f4 0.95 f5 -0.97 N1 1.5350 N2 1.6652 N3 1.6652 N4 1.6652

[0201]

Table 12

[0202] Condition formula Value Lower limit Upper limit (1) f / f1 1.158 0.5 1.4 (2) |f4 / f1| 0.770 0.4 2.0 (3) N1 < N4 Refer to Table 11 (4) N1 1.535 1.49 1.55 (5) N4 1.665 1.63 1.67 (6) f / OAL 0.770 0.6 0.9 (7) OAL / EfD1 2.598 2.2 3.2 (8) EXP / IH -0.992 -1.3 -0.9 (9) |f1 / f2| 0.643 0.40 0.71 (10) f3 / f1 0.753 0.30 2.80 (11) |f3 / f4| 0.979 0.5 2.0 (12) |f4 / f2| 0.495 0.20 1.30 (13) |f3 / f2| 0.485 0.10 1.50 (14) OAL / 2 * IH 0.806 0.70 1.00

[0203] These aberration diagrams, MTF, and distortion grids are as Figures 6A - 6C shown, but as is clear from each diagram, the performance is good.

[0204] [Example 4]

[0205] f = 1.5 mm, FNo. = 2.0, HFOV = 38.5°

[0206] The data of Example 4 are shown in Table 13.

[0207]

Table 13

[0208]

[0209] The data of the aspherical surface are as follows.

[0210]

Table 14

[0211]

[0212] The parameter values for each condition are as follows.

[0213]

Table 15

[0214] Item Value f 1.46 Fno 2.00 OAL 1.95 IH 1.18 EfD1 0.73 Half FOV 38.45 EP 0.00 EXP -1.17 f12 1.47 f3 -2.12 f4 1.32 f5 -1.95 N1 1.5350 N2 1.6328 N3 1.6328 N4 1.6328

[0215]

Table 16

[0216] Condition formula Value Lower limit Upper limit (1) f / f1 0.999 0.5 1.4 (2) |f4 / f1| 1.329 0.4 2.0 (3) N1 < N4 Refer to Table 15 (4) N1 1.535 1.49 1.55 (5) N4 1.633 1.63 1.67 (6) f / OAL 0.752 0.6 0.9 (7) OAL / EfD1 2.660 2.2 3.2 (8) EXP / IH -0.989 -1.3 -0.9 (9) |f1 / f2| 0.690 0.40 0.71 (10) f3 / f1 0.901 0.30 2.80 (11) |f3 / f4| 0.678 0.5 2.0 (12) |f4 / f2| 0.917 0.20 1.30 (13) |f3 / f2| 0.622 0.10 1.50 (14) OAL / 2 * IH 0.825 0.70 1.00

[0217] These aberration diagrams, MTF, and distortion grids are as Figures 8A - 8C shown, but as is clear from each aberration diagram, the performance is good.

[0218] [Example 5]

[0219] f = 1.4 mm, FNo. = 2.0, HFOV = 38.5°

[0220] The data for Example 5 are shown in Table 17.

[0221]

Table 17

[0222]

[0223] The data for the aspherical surface are as follows.

[0224]

Table 18

[0225]

[0226] The parameter values for each condition are as follows.

[0227]

Table 19

[0228] Item Value f 1.44 Fno 2.00 OAL 1.94 IH 1.18 EfD1 0.72 Half FOV 38.45 EP 0.00 EXP -1.21 f12 1.47 f3 -2.56 f4 1.64 f5 -2.79 N1 1.5168 N2 1.6328 N3 1.6328 N4 1.6328

[0229]

Table 20

[0230] Condition formula Value Lower limit Upper limit (1) f / f1 0.982 0.5 1.4 (2) |f4 / f1| 1.902 0.4 2.0 (3) N1 < N4 Refer to Table 19 (4) N1 1.517 1.49 1.55 (5) N4 1.633 1.63 1.67 (6) f / OAL 0.742 0.6 0.9 (7) 0AL / EfD1 2.695 2.2 3.2 (8) EXP / IH -1.025 -1.3 -0.9 (9) |f1 / f2| 0.573 0.40 0.71 (10) f3 / f1 1.121 0.30 2.80 (11) |f3 / f4| 0.589 0.5 2.0 (12) |f4 / f2| 1.090 0.20 1.30 (13) |f3 / f2| 0.643 0.10 1.50 (14) OAL / 2 * IH 0.822 0.70 1.00

[0231] These aberration diagrams, MTF, and distortion grids are as Figures 10A - 10C shown, but as is clear from each aberration diagram, the performance is good.

[0232] [Example 6]

[0233] f = 1.9 mm, FNo. = 2.0, HFOV = 32.4°

[0234] The data for Example 6 are shown in Table 21.

[0235]

Table 21

[0236]

[0237] The data of the aspherical surface is as follows.

[0238]

Table 22

[0239]

[0240] The parameter values of each condition are as follows.

[0241]

Table 23

[0242] Item Value f 1.83 Fno 2.00 OAL 2.12 IH 1.19 EfD1 0.91 Half FOV 32.42 EP 0.00 EXP -1.13 f12 1.43 f3 -3.40 f4 3.95 f5 -2.62 N1 1.5168 N2 1.6328 N3 1.6328 N4 1.6328

[0243]

Table 24

[0244] Condition formula Value Lower limit Upper limit (1) f / f1 1.278 0.5 1.4 (2) |f4 / f1| 1.831 0.4 2.0 (3) N1 < N4 Refer to Table 23 (4) N1 1.517 1.49 1.55 (5) N4 1.633 1.63 1.67 (6) f / OAL 0.863 0.6 0.9 (7) OAL / EfD1 2.317 2.2 3.2 (8) EXP / IH -0.949 -1.3 -0.9 (9) |f1 / f2| 0.421 0.40 0.71 (10) f3 / f1 2.761 0.30 2.80 (11) |f3 / f4| 1.508 0.5 2.0 (12) |f4 / f2| 0.770 0.20 1.30 (13) |f3 / f2| 1.162 0.10 1.50 (14) OAL / 2 * IH 0.892 0.70 1.00

[0245] These aberration diagrams, MTF, and distortion grids are as Figures 12A - 12C shown, but as is clear from each aberration diagram, the performance is good.

[0246] As described above, as in Embodiments 1 to 6, Figures 2A - 2C , Figures 4A - 4C , Figures 6A - 6C , Figures 8A - 8C , Figures 10A - 10C and Figures 12A - 12C shown, the photographing lens 100 of the present disclosure is bright, high-performance, and miniaturized (shortened in the optical axis direction), and the semi-field angle is approximately 50° realized by four lenses, and it is clear that it is suitable as a photographing device, particularly for a photographing device for a laptop PC.

[0247] As described above, several embodiments of the present application have been described in detail with reference to the drawings, but these embodiments are examples, and the present invention can be implemented in other ways in which various modifications and improvements are made based on the knowledge of those skilled in the art, starting from the manner described in the disclosure column of the present invention.

Claims

1. A photographing lens, wherein: have: The first to fourth lenses are arranged in order from the object side; and The aperture stop is located closest to the object. The first lens is a positive lens with its convex surface facing the object side. The second lens is a negative lens having an inflection point on at least one surface and a small deviation ratio. The third lens is a positive lens having a convex surface facing the image plane and a surface on the object side having an inflection point at the periphery of the lens. The fourth lens is a negative lens having a concave surface on the image side and an inflection point at the periphery. When the focal length of the first lens is set to f1, the focal length of the fourth lens is set to f4, and the focal length of the entire optical system is set to f, conditions (1) and (2) are satisfied, that is: 0.50<|f / f1|<1.40···(1) 0.40<|f4 / f1|<2.0···(2).

2. The imaging lens according to claim 1, wherein: The first to fourth lenses each have a near-infrared region corresponding coating covering the lens surface and covering at least one surface thereof, The coating layer corresponding to the near-infrared region transmits light in a band of 450 to 940 nm, and has a reflectivity of at least 2% or less in a band of 850 to 940 nm in the near-infrared region.

3. The imaging lens according to claim 1, wherein: When the refractive index of the material of the first lens for the d-line is set to N1, and the refractive index of the material of the fourth lens for the d-line is set to N4, condition (3) is satisfied, that is: N1<N4···(3).

4. The imaging lens according to claim 1, wherein: When the refractive index of the material of the first lens for the d-line is set to N1, condition (4) is satisfied, that is: 1.49＜N1＜1.55···(4)。 5. The photographing lens according to claim 1, wherein: When the refractive index of the material of the fourth lens for d-line is set to N4, condition (5) is satisfied, that is: 1.63＜N4＜1.67···(5)。 6. The photographing lens according to claim 1, wherein: When the focal length of the entire optical system is set to f and the total length of the optical system is set to OAL, condition (6) is satisfied, that is: 0.60<f / OAL<0.90···(6).

7. The photographing lens according to claim 1, wherein: When the total optical length is set to OAL and the optical effective diameter of the lens closest to the object is set to EfD1, condition (7) is satisfied, that is: 2.2<OAL / EfD1<3.2···(7).

8. The photographing lens according to claim 1, wherein: When the exit pupil position is set to EXP and the image height is set to IH, condition (8) is satisfied, that is: -1.3<EXP / IH<-0.90···(8).

9. The photographing lens according to claim 1, wherein: When the focal length of the first lens is set to f1 and the focal length of the second lens is set to f2, condition (9) is satisfied, that is: 0.40<|f1 / f2|<0.71···(9).

10. The photographing lens according to claim 1, wherein: When the focal length of the first lens is set to f1 and the focal length of the third lens is set to f3, condition (10) is satisfied: 0.3<f3 / f1<2.8···(10).

11. The photographing lens according to claim 1, wherein: When the focal length of the third lens is set to f3 and the focal length of the fourth lens is set to f4, condition (11) is satisfied, that is: 0.5<|f3 / f4|<2.0···(11).

12. An identification device, wherein: have: The imaging lens according to claim 2; and The single-body imaging element receives the image formed by the imaging lens and generates an imaging signal.

13. An information processing device, wherein: A recognition device according to claim 12 is provided.

Images