Imaging lens, imaging device, and information processing apparatus

Abstract

To provide a bright, high-performance, and small-sized imaging lens having a wide angle of view, an imaging device, and an information processing apparatus.SOLUTION: An imaging lens 100 includes: a first lens L1 to a fifth lens L5 arranged in order from an object side to an image side; and an aperture diaphragm S arranged between the first lens L1 and the second lens L2. The first lens L1 is a positive lens, in which a surface on the image side or the object side is a convex surface and the surface on the image side or the object side has an inflection point in the periphery and which has a small thickness deviation ratio, the second lens L2 is a biconvex positive lens, in which each surface on the image side and the object side is a convex surface or a surface on an image surface side is a convex positive lens, the third lens L3 is a negative lens in which a surface on the image side is a concave surface and the surface on the image side has an inflection point in the periphery, the fourth lens L4 is a positive lens in which a surface on the image side is a convex surface having strong curvature, and the fifth lens L5 is a negative lens in which a surface on the object side is a convex surface and has an inflection point in the periphery and a surface on the image side is a concave surface and has an inflection point in the periphery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an imaging lens, an imaging device, and an information processing device. [Background technology]

[0002] 2. Description of the Related Art In recent years, imaging devices such as digital still cameras, digital camcorders, and smartphone cameras that include solid-state imaging elements such as CCDs (Charge Coupled Devices) and CMOSs ​​(Complementary Metal Oxide Semiconductors) and imaging lenses have become widespread.

[0003] The solid-state imaging elements used in these imaging devices are becoming increasingly high-pixelated, and as the solid-state imaging elements become more highly pixelated, imaging lenses are also being required to have higher optical performance.

[0004] In recent years, PCs (Personal Computers) equipped with imaging devices are used to distribute videos and perform communication over the Web. For this reason, imaging devices are being made smaller in size with portability in mind. The imaging devices required in the market are mainly those that combine high performance and small size, and imaging lenses are also required to be not only high performance but also small in size. For this reason, imaging lenses that combine high performance and small size are known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2017-513034 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, in the case of video distribution via the Web, there has been a demand for imaging lenses that can capture images with a wider angle of view than conventional imaging lenses. For this reason, there has been a demand for imaging lenses that have a wider angle of view than conventional imaging lenses, are brighter, have higher performance, and are more compact.

[0007] The present disclosure has been made in consideration of the above, and has an object to provide an imaging lens, an imaging device, and an information processing device that have a wide angle of view, are bright, have high performance, and are small in size. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, an imaging lens according to a first aspect of the present disclosure includes a first lens to a fifth lens arranged in order from the object side to the image side, and an aperture stop arranged between the first lens and the second lens, the first lens being a positive lens whose image side or object side surface is convex and whose image side or object side surface has an inflection point at a periphery and has a small thickness deviation ratio, and the second lens being a biconvex positive lens whose image side and object side surfaces are both convex, or a positive lens whose image side surface is convex. the third lens is a negative lens whose image-side surface is concave and whose image-side surface has an inflection point at its periphery, the fourth lens is a positive lens whose image-side surface is a convex surface with a strong curvature, the fifth lens is a negative lens whose object-side surface is convex and has an inflection point at its periphery, and whose image-side surface is concave and has an inflection point at its periphery, and -15.0 <f1 / f5<-1.5 ···(1) 0.5<|f1 / G2|<13.0 (2) Satisfy.

[0009] An imaging device according to a second aspect of the present disclosure includes the imaging lens described above, and a solid-state imaging element that receives an image formed by the imaging lens and generates an imaging signal.

[0010] Moreover, an information processing device according to a third aspect of the present disclosure includes the imaging device described above, and a display unit that displays an image corresponding to the imaging signal generated by the imaging device. Effect of the Invention

[0011] The present disclosure has an effect of providing an imaging lens that has a wide angle of view, is bright, has high performance, and is small in size. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a lens configuration of an imaging lens according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is an aberration diagram of the imaging lens according to the first embodiment of the present disclosure. [Diagram 3] FIG. 3 is a diagram showing a lens configuration of an imaging lens according to a second embodiment of the present disclosure. [Figure 4] FIG. 4 is an aberration diagram of the imaging lens according to the second embodiment of the present disclosure. [Diagram 5] FIG. 5 is a diagram showing a lens configuration of an imaging lens according to the third embodiment of the present disclosure. [Figure 6] FIG. 6 is an aberration diagram of the imaging lens according to the third embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing a lens configuration of an imaging lens according to a fourth embodiment of the present disclosure. [Figure 8] FIG. 8 is an aberration diagram of the imaging lens according to the fourth embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram showing a lens configuration of an imaging lens according to a fifth embodiment of the present disclosure. [Figure 10] FIG. 10 is an aberration diagram of the imaging lens according to the fifth embodiment of the present disclosure. [Figure 11] FIG. 11 is a diagram showing a lens configuration of an imaging lens according to the sixth embodiment of the present disclosure. [Figure 12] FIG. 12 is an aberration diagram of the imaging lens according to the sixth embodiment of the present disclosure. [Figure 13]FIG. 13 is a diagram showing a schematic configuration of an information processing device including an imaging device having the imaging lens according to each embodiment of the present disclosure. [Figure 14] FIG. 14 is a diagram showing a schematic configuration of the imaging device of FIG. [Figure 15] FIG. 15 is a block diagram showing a functional configuration of an information processing device including an imaging device having the imaging lens according to each embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an imaging lens, an imaging device, and an information processing device according to the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following embodiments. Also, each drawing referred to in the following description merely shows the shape, size, and positional relationship in a schematic manner to the extent that the contents of the present disclosure can be understood. That is, the present disclosure is not limited to only the shape, size, and positional relationship exemplified in each drawing. Also, the same parts are given the same reference numerals, and detailed description will be omitted.

[0014] [Embodiment Mode] 1, 3, 5, 7, 9, and 11 are cross-sectional views showing the lens configurations of the imaging lenses of Embodiments 1 to 6. In each cross-sectional view, the left side is the object side (front) and the right side is the image side (rear).

[0015] The imaging lens 100 of each embodiment includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5, which are arranged in this order from the object side to the image side. Furthermore, the imaging lens 100 includes an aperture stop S(STOP) arranged between the first lens L1 and the second lens L2.

[0016] In addition, in Fig. 1, Fig. 3, Fig. 5, Fig. 7, Fig. 9 and Fig. 11, the reference characters 1 to 11 attached to any of the first lens L1 to the fifth lens L5 and the aperture stop S represent the surfaces of the respective lenses or the aperture. Hereinafter, these surfaces are successively referred to as surfaces 1 to 11 from the object side to the image side. Surface 3 is the surface of the aperture stop S. Furthermore, in Fig. 1, Fig. 3, Fig. 5 and Fig. 7, the reference character CG represents a transparent parallel plate equivalent to a cover glass of a solid-state imaging element and at least one or more of various filters. The entrance side of the transparent parallel plate CG is referred to as surface 12, and the image side is referred to as surface 13.

[0017] The imaging lens 100 is composed of a positive first group consisting of only the first lens L1, and a positive second group consisting of the second lens L2 to the fifth lens L5. By disposing an aperture stop S between the first and second groups, the imaging lens 100 can ensure a sufficient distance between the exit pupil and the image plane, achieve good telecentricity on the image side, and facilitate correction of spherical aberration and distortion.

[0018] The first lens L1 is a convex lens with a convex surface 1 on the object side or a convex surface 2 on the image side, and the object side surface 1 is configured using a positive lens with a small thickness deviation ratio (aspect ratio) that has an inflection point in the peripheral portion. Here, the thickness deviation ratio is approximately 0.6 to 1.0. The peripheral portion refers to a region that includes 30 to 60 percent of the aperture of the first lens L1 on the surface 1 side or the surface 2 side from the optical axis toward the outer edge.

[0019] The second lens L2 is configured using a biconvex positive lens in which the image-side surface 5 and the object-side surface 4 are both convex, or a positive lens in which the image-side surface 5 is convex.

[0020] The third lens L3 is configured using a negative lens whose image-side surface 6 is a concave surface, and whose image-side surface 6 has an inflection point at its periphery. Here, the periphery of the image-side surface 6 refers to an area that includes 50 to 80 percent of the position from the optical axis toward the outer edge with respect to the aperture of the third lens L3 on the surface 6 side.

[0021] The fourth lens L4 is constructed using a positive lens whose image-side surface 9 is a convex surface with a strong curvature.

[0022] The fifth lens L5 is configured using a negative lens in which the object-side surface 10 is a convex surface, the object-side surface 10 has an inflection point at its periphery, and the image-side surface 11 is a concave surface, the image-side surface 11 has an inflection point at its periphery. Here, the peripheral portion of the object-side surface 10 refers to a region including 60% to 80% of the aperture of the fifth lens L5 on the surface 10 side from the optical axis toward the outer edge. Also, the image-side surface 11 is a concave surface, and the peripheral portion refers to a region including 70% to the outermost position from the optical axis toward the outer edge with respect to the aperture of the fifth lens L5 on the surface 11 side.

[0023] The first lens L1 to the fifth lens L5 thus configured are all aspheric lenses, each characterized by its aspheric shape. Furthermore, by making the first lens L1 and the fifth lens L5 have a shape with an inflection point, it is possible to highly correct aberrations while keeping the thickness (total length) of the imaging lens 100 in the light direction thin. Furthermore, by making the thickness deviation ratio of the first lens L1 approximately 0.6 to 1.0, it is possible to reduce the sensitivity to manufacturing errors in the imaging lens 100.

[0024] 2, 4, 6, 8, 10, and 12 are longitudinal aberration diagrams of the imaging lens 100 of the first to sixth embodiments, respectively. In the spherical aberration diagrams, the amount of spherical aberration is shown for each of the d-line (yellow: wavelength 587.6 nm), g-line (blue: wavelength 435.8 nm), and C-line (red: 653.3 nm). In the astigmatism diagrams, the solid line S indicates the amount of astigmatism on the sagittal image plane, and the dashed line T indicates the amount of astigmatism on the tangential image plane. Furthermore, in the distortion diagrams, only the d-line is used, and the amount of distortion for the d-line is shown. In addition, Angle (deg) indicates the imaging half angle of view (°).

[0025] Next, the conditions of the imaging lens 100 in each embodiment will be described. The imaging lens 100 in 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 fifth lens L5 is f5, and the composite focal length of the lens on the image side from the aperture stop S is G2. -15.0 <f1 / f5<-1.5 ···(1) 0.5<|f1 / G2|<13.0 (2)

[0026] The condition (1) is a condition for balancing the negative power of the first lens L1 and the negative power of the fifth lens L5.

[0027] If f1 / f5 is equal to or less than the lower limit of condition (1), the astigmatism tends to be excessive, and distortion and coma also occur significantly, making it difficult to achieve the desired performance.If f1 / f5 is equal to or more than the upper limit of condition (1), the spherical aberration tends to be excessive, destroying the balance with the astigmatism and making it difficult to achieve the desired performance.

[0028] The condition (2) is a condition for balancing the positive power of the first lens L1 and the composite positive power of the second group consisting of the lenses (second lens L2 to fifth lens L5) on the image side from the aperture stop S.

[0029] When |f1 / G2| is equal to or less than the lower limit of condition (2), the positive power of the first lens L1 becomes relatively large compared to the composite power of the second group (second lens L2 to fifth lens L5), so that astigmatism becomes excessive, distortion becomes strongly barrel-shaped, and coma tends to be overcorrected. On the other hand, when |f1 / G2| is equal to or more than the upper limit of condition (2), the positive power of the first lens L1 becomes relatively small compared to the composite power of the second group, so that the balance between spherical aberration and astigmatism tends to be lost.

[0030] That is, when the imaging lens 100 satisfies the conditions (1) and (2), it is possible to achieve a balance between spherical aberration and astigmatism, and to realize a bright, high-performance, small-sized (compact) wide-angle imaging lens 100. Here, "small size" means reducing the thickness by shortening the overall length of the imaging lens 100 in the optical axis direction, and reducing the aperture of the imaging lens 100.

[0031] Furthermore, the imaging lens 100 of each embodiment satisfies condition (3) when the refractive index of the material of the first lens L1 to the d-line is N1 and the refractive index of the material of the fifth lens L5 to the d-line is N5. N1 <N5 ···(3)

[0032] Condition (3) is a condition that restricts the refractive index N1 of the material of the first lens L1 and the refractive index N5 of the material of the fifth lens L5.

[0033] The first lens L1 is a positive lens, and the fifth lens L5 is a negative lens. In order to correct chromatic aberration, it is common to use a low refractive index, low dispersion glass (optical material) for a positive convex lens, and a high refractive index, high dispersion glass (optical material) for a negative concave lens as an achromatic lens. For this reason, if condition (3) is not satisfied, chromatic aberration tends to become large, which is not preferable. In contrast, in the present disclosure, the refractive index N1 of the first lens L1 is formed from a material having a smaller refractive index than the refractive index N5 of the fifth lens L5, and by satisfying condition (3), chromatic aberration can be effectively corrected, and desired good chromatic aberration can be realized.

[0034] In the imaging lens 100 of each embodiment, the refractive index N1 of the material of the first lens L1 with respect to the d-line satisfies the condition (4). 1.49 <N1<1.55 ···(4)

[0035] If the refractive index N1 is equal to or less than the lower limit of condition (4), the optical performance is further improved, but the cost increases, which is not preferable. Also, if the refractive index N1 is equal to or greater than the upper limit of condition (4), the chromatic aberration is affected, which is not preferable. Therefore, by making the imaging lens 100 satisfy condition (4), a balance between cost and chromatic aberration can be achieved, and a bright, high-performance, and small (compact) imaging lens 100 can be realized.

[0036] In addition, in the imaging lens 100 of each embodiment, the refractive index N5 of the material of the fifth lens L5 with respect to the d-line satisfies the condition (5): 1.63 <N5<1.67 ···(5)

[0037] The condition (5) is a condition for the refractive index N5 of the fifth lens L5.

[0038] If the refractive index N5 is equal to or lower than the lower limit of the condition (5), or if the refractive index N5 is equal to or higher than the upper limit of the condition (5), the balance of chromatic aberration is lost. In consideration of the balance between cost and chromatic aberration, satisfying the condition (5) makes it possible to realize a bright, high-performance, and compact imaging lens 100.

[0039] Furthermore, the imaging lens 100 of each embodiment satisfies condition (6), where the focal length of the entire optical system (imaging lens 100) is f and the overall length of the optical system (in the longitudinal direction of imaging lens 100) is OAL. 0.3 <f / OAL<0.7 ···(6)

[0040] Condition (6) is a condition for achieving a balance between the focal length f of the entire optical system and the total length OAL.

[0041] In imaging lens 100 of each embodiment, if f / OAL is equal to or less than the lower limit of condition (6), a wider angle can be achieved, but the front lens diameter tends to be larger, which may lead to an increase in size. If f / OAL is equal to or greater than the upper limit of condition (6), the overall length of the optical system becomes smaller, but it becomes difficult to achieve a wider angle of view. Imaging lens 100 that satisfies condition (6) can achieve a smaller size and a wider angle of view.

[0042] Moreover, the imaging lens of each embodiment satisfies the condition (7), where OAL is the total length of the optical system, and SDo is the effective optical diameter of the lens (first lens L1) arranged closest to the object side. 1.5 <OAL / SDo<3.0 ···(7)

[0043] The condition (7) is a condition for achieving a balance between the overall lens length and the front lens diameter of the first lens element L1.

[0044] If OAL / SDo is equal to or less than the lower limit of condition (7), the optical system will be compact (shortened in the optical axis direction), but it will be difficult to achieve a wide angle of view. If OAL / SDo is equal to or greater than the upper limit of condition (7), the performance of the optical system will improve, but it will be difficult to achieve compactness (shortened in the optical axis direction). By satisfying condition (7), imaging lens 100 can achieve compactness (shortened in the optical axis direction) and high performance.

[0045] Furthermore, the imaging lens 100 of each embodiment satisfies the condition (8) when the focal length of the fourth lens L4 is f4 and the focal length of the fifth lens L5 is f5. 0.5<|f4 / f5|<1.0 (8)

[0046] The condition (8) is a condition for placing distortion in an optimum range.

[0047] If |f4 / f5| is equal to or less than the lower limit of condition (8), the optical system will tend to have pincushion distortion, and if |f4 / f5| is equal to or greater than the upper limit of condition (8), the optical system will tend to have barrel distortion. Therefore, by satisfying condition (8), imaging lens 100 can achieve distortion within an optimal range.

[0048] Furthermore, the imaging lens of each embodiment satisfies condition (9), where EXP is the exit pupil position and IH is the image height. -2.0 <EXP / IH<-0.5 ···(9)

[0049] Condition (9) is a condition for optimizing the angle of incidence of a light ray on the image plane.

[0050] When EXP / IH is equal to or less than the lower limit of condition (9), the light incidence angle tends to be low, but it tends to be difficult to reduce the overall length of the optical system and thereby achieve compactness. When EXP / IH is equal to or greater than the upper limit of condition (9), the light incidence angle tends to be high. For this reason, imaging lens 100 can achieve compactness by satisfying condition (9). Therefore, it is preferable that imaging lens 100 satisfy condition (9).

[0051] Moreover, the imaging lens 100 of each embodiment satisfies the condition (10) when the optical effective diameter of the lens closest to the object is SDo and the entrance pupil diameter of the optical system is ENP_D. 1.0 <SDo / ENP_D<3.0 ···(10)

[0052] The condition (10) is a condition for achieving both a wide angle of view and brightness.

[0053] When SDo / ENP_D is equal to or less than the lower limit of condition (10), the optical system becomes brighter but tends to have larger spherical aberration, whereas when SDo / ENP_D is equal to or greater than the upper limit of condition (10), the optical system tends to have corrected spherical aberration but tends to become darker. Here, brightness refers to F-number. Also, darker brightness refers to a larger F-number.

[0054] Furthermore, the imaging lens 100 of each embodiment satisfies the condition (11), where OAL is the total optical length and IH is the image height. 0.5 <OAL / (2*IH)<1.1 ···(11)

[0055] Condition (11) defines the relationship between the overall length of imaging lens 100 and the image height.

[0056] When OAL / (2*IH) is equal to or less than the lower limit of condition (11), the overall length of the optical system tends to be short, but when OAL / (2*IH) is equal to or greater than the upper limit of condition (11), the overall length of the optical system becomes long. For this reason, by satisfying condition (11), imaging lens 100 can achieve a balance between a short shape (low height) and high performance.

[0057] [Imaging device] Next, an embodiment of an information processing device (PC) including an imaging device using the imaging lens 100 of each embodiment as an imaging optical system will be described.

[0058] Fig. 13 is a diagram showing a schematic configuration of an information processing device including an imaging device having the imaging lens 100 of each embodiment. Fig. 14 is a diagram showing a schematic configuration of the imaging device of Fig. 13. Fig. 15 is a block diagram showing a functional configuration of an information processing device including an imaging device having the imaging lens of each embodiment.

[0059] 13 to 15 includes at least an imaging 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 and an audio input / output unit 39.

[0060] The imaging device 31 generates an imaging signal by capturing an image of a predetermined field of view under the control of the control unit 34, and outputs the imaging signal to the signal processing unit 32. As shown in Fig. 10, the imaging device 31 includes at least a cover 311, the imaging lens 100 of each embodiment, and a solid-state imaging element 312. The imaging device 31 is disposed on the front side of the information processing device 30. Specifically, the imaging device 31 is disposed at a position where the imaging device 31 can capture an image of the user of the information processing device 30. Of course, the position of the imaging device 31 can be appropriately changed depending on the shape, size, and usage mode of the information processing device 30.

[0061] The cover 311 is configured using a cover glass or the like that is a member for preventing dirt and dust from being generated on the imaging lens 100. Note that the information processing device 30 may further provide the cover 311 with a lid or the like that opens and closes in response to a user's operation.

[0062] The solid-state imaging element 312 receives an image of an object formed by the imaging lens 100 and generates an imaging signal by performing photoelectric conversion. The solid-state imaging element 312 is configured using a CCD sensor, a CMOS sensor, or the like. The solid-state imaging element 312 preferably has 8 million or more effective pixels, so-called 4K or more (3840×2160 or more), arranged in a two-dimensional matrix.

[0063] Under the control of the control unit 34, the signal processing unit 32 performs A / D conversion processing and the like on the imaging signal input from the solid-state imaging element 312 to convert it into a digital imaging signal and outputs it to the image processing unit 33. The signal processing unit 32 is configured using, for example, a DSP (Digital Signal Processor) or the like.

[0064] Under the control of the control unit 34, the image processing unit 33 performs predetermined image processing on the digital imaging signal input from the signal processing unit 32, and outputs the result to the display unit 35 or the storage unit 36. The image processing unit 33 is configured using, for example, a GPU (Graphics Processing Unit) or the like. Here, the predetermined image processing includes electrical shading correction processing, white balance adjustment processing, image center trimming processing, noise reduction processing, and the like.

[0065] 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 configured using a CPU, a Field-Programmable Gate Array (FPGA), etc. The memory is configured using a Random Access Memory (RAM), a Read Only Memory (ROM), etc.

[0066] Under the control of the control unit 34, the display unit 35 displays the video being shot that has been image-processed by the image processing unit 33, the captured image, the still image corresponding to the image signal stored in the memory unit 36, and various information related to the information processing device 30.

[0067] The storage unit 36 ​​stores various information related to the information processing device 30, programs executed by the information processing device 30, and imaging signals (RAW data and JPEG data) captured by the imaging device 31. The storage unit 36 ​​is configured using a flash memory, an SSD (Solid State Drive), an HDD (Hard Disk Drive), a memory card, etc.

[0068] The communication unit 37 transmits an imaging signal captured by the imaging device 31 to the outside via a network in accordance with a predetermined communication standard under the control of the control unit 34, and receives various information input from the outside. The communication unit 37 uses a communication standard that complies with communication standards such as 3GPP (registered trademark), 4G established by IEEE, LTE, 5G, WiMAX, and Wi-Fi (registered trademark), etc.

[0069] The input unit 38 receives an operation input from the user, and outputs operation information corresponding to the received operation to the control unit 34. The input unit 38 is configured using, for example, a touch panel, a keyboard, a mouse, and the like.

[0070] Under the control of the control unit 34, the audio input / output unit 39 receives an input of an external sound, converts it into an audio signal, and outputs it to the storage unit 36 ​​or the communication unit 37. Also, under the control of the control unit 34, the audio input / output unit 39 converts an 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 configured using a microphone, a speaker, and the like.

[0071] The information processing device 30 configured in this manner can use the imaging device 31 having the imaging lens 100 to communicate with an external device in high-quality 4K by Web communication via a network.

[0072] In the embodiment, a PC has been described as an example of the information processing device 30, but the imaging device 31 can be applied to imaging devices such as tablet terminals, mobile phones, etc. Of course, the imaging device 31 can also be applied to a Web camera or the like that can communicate with a PC or the like via wired or wireless communication.

[0073] According to the embodiment described above, it is possible to realize a wide-angle of view, bright, high-performance, and compact camera.

[0074] Moreover, according to the embodiment, a half angle of view of 40° to 55° can be achieved with five lenses.

[0075] Furthermore, according to the embodiment, imaging lens 100 can be realized that has a wide angle of view, a small F-number, high performance, and a small size. Therefore, in the case of shooting moving images, it is possible to handle shooting in various environments such as dark environments and to increase the shooting speed.

[0076] Furthermore, according to the embodiment, it is possible to realize a wide-angle, bright, high-performance, and compact device, thereby improving the matching between the angle of incidence at the light receiving element of the solid-state imaging element on the image side and the light rays incident on the light receiving surface.

[0077] Furthermore, according to the embodiment, a bright, high-performance, and compact lens with a half angle of view of 40° to 50° can be constructed from five lenses, and therefore it can be used as a fixed focal length lens for use in mobile phones such as smartphones and PCs, for example. Therefore, when there is a demand for high-pixel video capture of 4K or more (3840 x 2160 or more), sufficient aberration correction can be performed compared to conventional imaging lenses, and the required performance can be met.

[0078] Furthermore, according to the embodiment, a bright, high-performance, and compact half angle of view of 40° to 50° can be configured with five lenses, so that the overall length of the imaging lens 100 in the optical axis direction can be shortened, and the lens diameter can be reduced, realizing miniaturization. This reduces the refractive power of the miniaturized lens, and also reduces the effects of manufacturing errors and assembly errors. As a result, productivity can be improved, and production costs can be reduced. EXAMPLES

[0079] Examples 1 to 6 of the imaging lens 100 corresponding to the first to sixth embodiments, respectively, are given below. The meanings of symbols in each example are as follows: f: focal length of the entire lens system Lensf: focal length of each lens Groupf: Focal length of each group FNo.: Aperture (F number) R: Radius of curvature of the surface D: Surface spacing Nd: Refractive index for the d line Vd: Abbe number for d line IP: Inflection Point The inflection point indicates the position of the inflection point when the effective radius is 1.0. For example, "0.6" indicates that the inflection point is located at 60% of the effective radius. A hyphen (-) indicates that the inflection point is not within the clear diameter. A hyphen is also used to indicate that the inflection point is outside the clear diameter. TP: Uneven thickness ratio (Thickness Point=peripheral thickness / center thickness) The thickness deviation ratio is the ratio of the peripheral thickness to the central thickness. For example, "1.5" indicates that the peripheral thickness is 1.5 times thicker than the central thickness. An aspheric surface is expressed by the well-known formula (12) below, using aspheric coefficients, where X is the depth in the optical axis direction, H is the height from the optical axis, R is the paraxial radius of curvature, k is the conic constant, and CN is a higher-order aspheric coefficient (N=4 or more even number). X=(H 2 / R) / [1+{1-k(H / r) 2} 1 / 2 ] +Σ N=4:even CNH N (12) Here, Σ N≧4:even means the sum for N being an even number greater than or equal to 4.

[0080] [Example 1] f=1.9mm, FNo.=2.0, HFOV=40° The data for Example 1 is shown in Table 1.

[0081] [Table 1]

[0082] The aspheric data is shown below. [Table 2] In the above notation of aspheric surfaces, for example, "1.3366E-04" is "1.3366*10 -4 This also applies to the other examples described below.

[0083] The parameter values ​​for each condition are as follows: [Table 3]

[0084] [Table 4]

[0085] In each embodiment, the first lens L1 to the fifth lens L5 have aspheric surfaces, and the aspheric surfaces effectively correct aberrations.

[0086] FIG. 2 shows aberration diagrams relating to the above-mentioned Example 1, and as is clear from each aberration diagram, the performance is excellent.

[0087] [Example 2] f=1.6mm, FNo.=2.0, HFOV=45° The data for Numerical Example 2 is shown in Table 5.

[0088] [Table 5]

[0089] The aspheric data is shown below. [Table 6]

[0090] The parameter values ​​for each condition are as follows: [Table 7] [Table 8]

[0091] These aberration diagrams are shown in FIG. 4, and as is clear from each aberration diagram, the performance is excellent.

[0092] [Example 3] f=1.4mm, FNo.=2.0, HFOV=50° The data for Example 3 is shown in Table 9.

[0093] [Table 9]

[0094] The aspheric data is shown below. [Table 10]

[0095] The parameter values ​​for each condition are as follows: [Table 11]

[0096] [Table 12]

[0097] These aberration diagrams are shown in FIG. 6, and as is clear from each aberration diagram, the performance is excellent.

[0098] [Example 4] f=2.6mm, FNo.=2.4, HFOV=50.5° The data for Example 4 is shown in Table 13. [Table 13]

[0099] The aspheric data is shown below. [Table 14]

[0100] The parameter values ​​for each condition are as follows: [Table 15]

[0101] [Table 16]

[0102] These aberration diagrams are shown in FIG. 8, and as is clear from each aberration diagram, the performance is excellent.

[0103] [Example 5] f=2.7mm, FNo.=2.0, HFOV=49° The data for Example 5 is shown in Table 17. [Table 17]

[0104] The aspheric data is shown below. [Table 18]

[0105] The parameter values ​​for each condition are as follows: [Table 19]

[0106] [Table 20]

[0107] These aberration diagrams are shown in FIG. 10, and as is clear from each aberration diagram, the performance is excellent.

[0108] [Example 6] f=2.1mm, FNo.=2.4, HFOV=55° The data for Example 6 is shown in Table 21. [Table 21]

[0109] The aspheric data is shown below. [Table 22]

[0110] The parameter values ​​for each condition are as follows: [Table 23]

[0111] [Table 24]

[0112] These aberration diagrams are shown in FIG. 12, and as is clear from each aberration diagram, the performance is excellent.

[0113] As described above, as shown in Examples 1 to 6 and FIGS. 2, 4, 6, 8, 10, and 12, the imaging lens 100 of the present disclosure is bright, has high performance, is compact (shortened in the optical axis direction), has little distortion, and achieves a half angle of view of 40° to 55° with a five-lens configuration, and is clearly suitable as an imaging device, particularly an imaging device for laptop PCs.

[0114] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be embodied in other forms that incorporate various modifications and improvements based on the knowledge of those skilled in the art, including the forms described in the disclosure of the present invention. [Explanation of symbols]

[0115] 30 Information processing device 31 Imaging device 100 Imaging Lens L1 First lens L2 Second lens L3 Third lens L4 4th lens L5 5th lens S aperture stop CG cover glass

Claims

1. a first lens to a fifth lens arranged in order from the object side to the image side; an aperture stop disposed between the first lens and the second lens; Equipped with The first lens is a positive lens having a convex surface on the image side or the object side, the surface on the image side or the object side having an inflection point at a periphery and a small thickness deviation ratio; The second lens is A biconvex positive lens whose image-side and object-side surfaces are both convex, or a positive lens whose image-side surface is convex, The third lens is a negative lens having a concave image-side surface and an inflection point at a periphery thereof; The fourth lens is The image-side surface is a positive lens with a strong convex curvature. The fifth lens is a negative lens having a convex surface on the object side with an inflection point at the periphery and a concave surface on the image side with an inflection point at the periphery, When the focal length of the entire system is F, the focal length of the first lens is f1, the focal length of the fifth lens is f5, and the composite focal length of the lens on the image side from the aperture stop is G2, conditions (1) and (2) are satisfied: -15.0<f1 / f5<-1.5...(1) 0.5<|f1 / G2|<13.0...(2) An imaging lens that satisfies the above requirements.

2. The imaging lens according to claim 1 , When the refractive index of the material of the first lens with respect to the d line is N1 and the refractive index of the material of the fifth lens with respect to the d line is N5, condition (3) is satisfied. N1<N5...(3) An imaging lens that satisfies the above requirements.

3. The imaging lens according to claim 1 , The refractive index N1 of the material of the first lens with respect to the d line satisfies the condition (4), 1.49<N1<1.55 (4) An imaging lens that satisfies the above requirements.

4. The imaging lens according to claim 1 , The refractive index N5 of the material of the fifth lens with respect to the d line satisfies the condition (5), 1.63<N5<1.67...(5) An imaging lens that satisfies the above requirements.

5. The imaging lens according to claim 1 , When the focal length of the entire optical system is f and the total length of the optical system is OAL, condition (6) is satisfied. 0.3<f / OAL<0.7...(6) An imaging lens that satisfies the above requirements.

6. The imaging lens according to claim 1 , When the total length of the optical system is OAL and the optical effective diameter of the fifth lens arranged closest to the image side is SDo, the condition (7) is satisfied, 1.5<OAL / SDo<3.0...(7) An imaging lens that satisfies the above requirements.

7. The imaging lens according to claim 1 , When the focal length of the fourth lens is f4 and the focal length of the fifth lens is f5, condition (8) is satisfied. 0.5<|f4 / f5|<1.0...(8) An imaging lens that satisfies the above requirements.

8. The imaging lens according to claim 1 , When the exit pupil position is EXP and the image height is IH, condition (9) is satisfied. -2.0<EXP / IH<-0.5...(9) An imaging lens that satisfies the above requirements.

9. The imaging lens according to claim 1 , When the optical effective diameter of the lens closest to the object is SDo and the entrance pupil diameter of the optical system is ENP_D, condition (10) is satisfied. 1.0<SDo / ENP_D<3.0 (10) An imaging lens that satisfies the above requirements.

10. The imaging lens according to claim 1 , When the total optical length is OAL and the image height is IH, condition (11) is satisfied. 0.5<OAL / (2*IH)<1.1...(11) An imaging lens that satisfies the above requirements.

11. The imaging lens according to claim 1 ; a solid-state image sensor that receives an image formed by the imaging lens and generates an image signal; Equipped with Imaging device.

12. The imaging device according to claim 11 ; a display unit that displays an image corresponding to the imaging signal generated by the imaging device; Equipped with Information processing device.

Images