Optical imaging system and imaging device and electronic device having the same

Abstract

The present invention discloses an optical imaging system and an imaging device and an electronic device having the same, wherein the optical imaging system comprises: an optical lens group, wherein the optical lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence along the axial direction, wherein the object side surface of the first lens is a convex surface at the optical axis, the object side surface of the second lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis, and the object side surface of the fourth lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis; wherein the optical imaging system satisfies: TL / Imgh<1.5, wherein TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis, and Imgh is half the diagonal length of the effective pixel area on the imaging surface. The optical imaging system according to the present invention can have both miniaturization and high-definition shooting, effectively improve the shooting effect, and can meet the shooting needs of users for camera lenses.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to an optical imaging system and an imaging device and an electronic device having the same. Background Art

[0002] With the widespread application of micro cameras in electronic products such as mobile phones, tablets, drones, computers, etc., the innovation of camera lens shooting effects in the improvement of new electronic products has become one of the focuses of people's attention, and it has also become an important part of scientific and technological improvement. At present, people's shooting effects of visible light can no longer meet the shooting needs of modern camera lenses. The latest infrared light wave detection camera can directly record depth information to process photos, and can also blur scenes and people at different depths to different degrees, which has greatly improved the effects of video and photography. Therefore, infrared cameras with high-definition shooting quality have become the focus of design.

[0003] In the related art, micro cameras for infrared band imaging cannot meet the needs of high-definition image capture. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide an optical imaging system that can achieve high-definition photography while achieving miniaturization.

[0005] Another object of the present invention is to provide an imaging device having the above optical imaging system.

[0006] Another object of the present invention is to provide an electronic device having the above-mentioned imaging device.

[0007] According to an embodiment of the first aspect of the present invention, the optical imaging system comprises: an optical lens group, the optical lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence along the axial direction, the first lens, the second lens, the third lens and the fourth lens have a refractive power, the object side surface of the first lens is a convex surface at the optical axis, the object side surface of the second lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis, and the second lens is provided with at least one inflection point, the object side surface of the fourth lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis; wherein the optical imaging system satisfies: TL / Imgh<1.5, wherein TTL is the distance from the object side surface of the first lens to the imaging plane on the optical axis, and Imgh is half of the diagonal length of the effective pixel area on the imaging plane.

[0008] According to the optical imaging system of the embodiment of the present invention, by arranging a first lens, a second lens, a third lens and a fourth lens with refractive power arranged in sequence along the axial direction, and making the distance TTL from the object side of the first lens to the imaging plane on the optical axis and half the diagonal length of the effective pixel area on the imaging plane Imgh satisfy the relationship TTL / Imgh<1.5, the optical lens group can have both miniaturization and high-definition shooting, effectively improving the shooting effect, and meeting the shooting needs of users for camera lenses.

[0009] According to some embodiments of the present invention, the effective aperture diameter of the first lens is L, wherein L satisfies: 0.3<L / Imgh<0.7. Thus, by making 0.3<L / Imgh<0.7, the clarity of the captured image is further guaranteed, fully meeting the needs of users.

[0010] According to some embodiments of the present invention, the aperture number of the optical lens group is Fno, wherein Fno satisfies: Fno / TTL<0.4. Thus, by making Fno / TTL<0.4, the optical imaging system can have both large aperture and miniaturization, providing sufficient light throughput for the optical imaging system, thereby meeting the requirements of high-quality and high-definition shooting.

[0011] According to some embodiments of the present invention, the optical lens group further includes a stop, and the diameter of the stop aperture is D, wherein D satisfies: 1.5<TTL / D<3.0. Thus, by satisfying 1.5<TTL / D<3.0, the optical imaging system can simultaneously meet the requirements of optical performance optimization and structural miniaturization.

[0012] According to some embodiments of the present invention, the total effective focal length of the optical lens group is f, wherein f satisfies: 1.0<TTL / f<2.0. Thus, by making 1.0<TTL / f<2.0, the optical lens can be miniaturized while ensuring that light is better converged on the imaging surface.

[0013] According to some embodiments of the present invention, the optical lens group further includes a stop, the diameter of the stop aperture is D, and the aperture number of the optical lens group is Fno, wherein D and Fno satisfy: 2<D×FNO<3. Thus, by making 2<D×FNO<3, the ratio of the diameter of the stop aperture and the aperture number of the optical lens group is reasonably controlled, and the optical imaging system can be guaranteed to have the best light throughput and picture clarity.

[0014] According to some embodiments of the present invention, the optical effective focal length of the first lens is f1, and the total effective focal length of the optical lens group is f, wherein f1 and f satisfy: -0.35<f / f1<0.35. Such a setting can reduce the sensitivity of the optical imaging system and meet the shooting requirements.

[0015] According to some embodiments of the present invention, the shortest distance from the image side surface of the fourth lens to the imaging surface parallel to the optical axis is FBL, wherein the FBL satisfies: 0.1<FBL / TTL<0.25. With such a configuration, the optical imaging system can take into account the miniaturization of the lens while ensuring that the imaging lens has sufficient focusing space during the installation process of the optical lens group, thereby improving the assembly yield of the optical lens group. Moreover, with the above configuration, the focal depth of the imaging lens can be widened to obtain more depth information.

[0016] According to some embodiments of the present invention, the radius of curvature of the object side surface of the first lens is R1, the radius of curvature of the image side surface of the first lens is R2, and the focal length of the first lens is f1, wherein R1, R2 and f1 satisfy: -1.5<(R1+R2) / f1<2. Thus, by making -1.5<(R1+R2) / f1<2, the imaging effect of the optical imaging system can be further guaranteed, making the captured image clearer.

[0017] According to some embodiments of the present invention, the radius of curvature of the object side surface of the third lens is R6, and the radius of curvature of the image side surface of the third lens is R7, wherein R6 and R7 satisfy: -8<R6 / R7<3.5. Thus, when the lens group satisfies the above formula, the radius of curvature of the object side surface and the radius of curvature of the image side surface of the third lens are more reasonable, the incident angle can be increased to meet the image height requirement of the optical imaging system, and the system sensitivity can be reduced, and the assembly stability can be improved.

[0018] According to some embodiments of the present invention, the optical effective focal length of the third lens is f3, and the total effective focal length of the optical lens group is f, wherein f3 and f satisfy: -40<f3 / f<6. Thus, by making -40<f3 / f<6, the ratio of the optical effective focal length of the third lens to the total effective focal length of the optical lens group can effectively reduce the total length of the optical imaging system, which is beneficial to the convergence of light on the imaging surface.

[0019] According to some embodiments of the present invention, the radius of curvature of the object side surface of the fourth lens is R8, and the radius of curvature of the image side surface of the fourth lens is R9, wherein R8 and R9 satisfy: 0.4<(R8×R9) / (R8+R9)<0.55. Thus, the longitudinal spherical aberration of the optical imaging system can be reasonably corrected, the distortion aberration and astigmatism can be improved, and the sensitivity of the optical imaging system can be reduced, and the assembly stability can be improved.

[0020] According to some embodiments of the present invention, the maximum optical effective area edge thickness of the third lens is ET3, and the thickness of the third lens on the optical axis is CT3, wherein ET3 and CT3 satisfy: 0.2<ET3 / CT3<0.8. Such a setting can ensure sufficient tolerance margin and improve molding yield.

[0021] According to some embodiments of the present invention, the radius of curvature of the object side surface of the second lens is R4, and the radius of curvature of the image side surface of the second lens is R5, wherein R4 and R5 satisfy: -15<(R4+R5) / (R4-R5)<90. Thus, by making -15<(R4+R5) / (R4-R5)<90, the sensitivity of the optical imaging system can be reduced, and the processing yield can be guaranteed.

[0022] An imaging device according to an embodiment of a second aspect of the present invention comprises: a photosensitive element; and an optical imaging system, wherein the optical imaging system is the optical imaging system according to the embodiment of the first aspect of the present invention.

[0023] The imaging device according to the embodiment of the present invention adopts the above optical imaging system, so the number of lenses is small, which is conducive to miniaturization design, and can achieve high-definition shooting, thereby improving the overall performance of the imaging device.

[0024] An electronic device according to an embodiment of a third aspect of the present invention comprises: a housing; and an imaging device, wherein the imaging device is the imaging device according to the embodiment of the second aspect of the present invention.

[0025] The electronic device according to the embodiment of the present invention adopts the above-mentioned imaging device, so that the electronic device has the advantages of both miniaturization and high definition, and fully meets the needs of users.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic structural diagram of an optical imaging system according to a first embodiment of the present invention;

[0029] Figure 2 yes Figure 1 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0030] Figure 3 is a schematic structural diagram of an optical imaging system according to a second embodiment of the present invention;

[0031] Figure 4 yes Figure 3 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0032] Figure 5 is a schematic structural diagram of an optical imaging system according to a third embodiment of the present invention;

[0033] Figure 6 yes Figure 5 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0034] Figure 7 is a schematic structural diagram of an optical imaging system according to a fourth embodiment of the present invention;

[0035] Figure 8 yes Figure 7 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0036] Fig. 9 is a schematic structural diagram of an optical imaging system according to a fifth embodiment of the present invention;

[0037] Fig.10 yes Fig. 9 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0038] Fig.11 is a schematic structural diagram of an optical imaging system according to a sixth embodiment of the present invention;

[0039] Fig.12 yes Fig.11 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0040] Fig.13 is a schematic structural diagram of an optical imaging system according to a seventh embodiment of the present invention;

[0041] Fig.14 yes Fig.13 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0042] Fig.15 is a schematic structural diagram of an optical imaging system according to an eighth embodiment of the present invention;

[0043] Fig.16 yes Fig.15 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0044] Fig.17 is a schematic structural diagram of an optical imaging system according to a ninth embodiment of the present invention;

[0045] Fig.18 yes Fig.17 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in;

[0046] Fig.19 is a schematic structural diagram of an optical imaging system according to a tenth embodiment of the present invention;

[0047] Fig. 20 yes Fig.19 The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system shown in .

[0048] Reference numerals:

[0049] 100: optical imaging system;

[0050] 1: first lens; 2: second lens; 3: third lens;

[0051] 4: fourth lens; 5: aperture; 6: infrared bandpass filter. DETAILED DESCRIPTION

[0052] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0053] Reference below Figure 1-Figure 20 An optical imaging system 100 according to an embodiment of the first aspect of the present invention is described.

[0054] like Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 As shown, the optical imaging system 100 according to an embodiment of the present invention includes an optical lens group.

[0055] Specifically, the optical lens group includes a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 arranged in sequence along the axial direction, the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 have refractive power, the object side surface of the first lens 1 is convex at the optical axis, the object side surface of the second lens 2 is convex at the optical axis, and the image side surface is concave at the optical axis, and the second lens 2 is provided with at least one inflection point, the object side surface of the fourth lens 4 is convex at the optical axis, and the image side surface is concave at the optical axis. Among them, the optical imaging system 100 satisfies: TTL / Imgh<1.5, wherein TTL is the distance from the object side surface of the first lens 1 to the imaging surface on the optical axis, and Imgh is half of the diagonal length of the effective pixel area on the imaging surface.

[0056] For example, in Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 In the example, the photosensitive element is arranged on the image side of the fourth lens 4, the object side of the fourth lens 4 is convex at the optical axis, and the image side of the fourth lens 4 is concave at the optical axis, which can effectively correct the field curvature of the optical imaging system 100, so that the photographed object can be imaged flat on the imaging surface. When the optical imaging system 100 satisfies TTL / Imgh<1.5, it can have both miniaturization and high-definition shooting, and has a larger amount of light intake compared to traditional miniature cameras, which effectively improves the shooting effect and meets the user's shooting needs for camera lenses.

[0057] According to the optical imaging system 100 of the embodiment of the present invention, by arranging a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 with refractive power arranged in sequence along the axial direction, and making the distance TTL from the object side surface of the first lens 1 to the imaging surface on the optical axis and the half of the diagonal length of the effective pixel area on the imaging surface Imgh satisfy the relationship TTL / Imgh<1.5, the optical lens group can have both miniaturization and high-definition shooting, effectively improving the shooting effect, and meeting the shooting needs of users for camera lenses.

[0058] In some embodiments of the present invention, reference Figure 1-Figure 20, the effective aperture diameter of the first lens 1 is L, where L satisfies: 0.3<L / Imgh<0.7. It should be noted that since the effective aperture diameter of the first lens 1 determines the light throughput of the entire optical imaging system 100, and the size of the photosensitive surface determines the picture clarity and pixel size of the entire camera system, a reasonable ratio of the two can ensure sufficient light throughput while ensuring the clarity of the captured image. If L / Imgh>0.7, it will cause overexposure and too high brightness, affecting the picture quality; if L / Imgh<0.3, it will cause insufficient light throughput and insufficient relative brightness of the light, resulting in a decrease in picture clarity. Therefore, by making 0.3<L / Imgh<0.7, the clarity of the captured image is further guaranteed, fully meeting user needs.

[0059] Further, refer to Figure 1-Figure 20 , the aperture number of the optical lens group is Fno, where Fno satisfies: Fno / TTL<0.4. When Fno / TTL>0.4, the optical imaging system 100 satisfies miniaturization, but will result in insufficient light transmission, which reduces the clarity of the captured image. Therefore, by making Fno / TTL<0.4, the optical imaging system 100 can have both a large aperture and miniaturization, providing sufficient light transmission for the optical imaging system 100, thereby meeting the requirements of high-quality and high-definition shooting.

[0060] In a further embodiment of the present invention, Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 As shown, the optical lens group also includes an aperture 5, and the diameter of the aperture of the aperture 5 is D, where D satisfies: 1.5<TTL / D<3.0. When TTL / D<1.5, the aperture diameter will be too large when the miniaturization design is met, causing the edge light to enter the optical imaging system 100, reducing the imaging quality; if TTL / D>3, while meeting the miniaturization, the aperture diameter of the aperture 5 will be too small, unable to meet the system light throughput, and unable to achieve the high-definition shooting requirements of dark light scenes. Therefore, by making 1.5<TTL / D<3.0, the optical imaging system 100 can simultaneously meet the optimization of optical performance and miniaturization of structure.

[0061] Optionally, refer to Figure 1-Figure 20, the total effective focal length of the optical lens group is f, where f satisfies: 1.0<TTL / f<2.0. For example, when TTL / f≤1.0, the optical length of the optical lens group is too short, which increases the sensitivity of the system and is not conducive to the convergence of light on the imaging surface; when TTL / f≥2, the optical length of the optical lens group is too long, which will cause the main ray angle of the light entering the imaging surface to be too large, and the edge light of the imaging surface of the optical imaging system 100 cannot be imaged on the photosensitive surface, resulting in incomplete imaging information. Therefore, by making 1.0<TTL / f<2.0, while realizing the miniaturization of the optical lens, it can ensure that the light is better converged on the imaging surface.

[0062] Alternatively, if Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.15 , Fig.17 and Fig.19 As shown, the optical lens group also includes an aperture 5, the diameter of the aperture 5 is D, and the aperture number of the optical lens group is Fno, wherein D and Fno satisfy: 2<D×FNO<3. For example, when D×FNO<2, it is not conducive to the convergence of light on the imaging surface, and a large amount of stray light is generated, resulting in a decrease in shooting quality; when D×FNO>3, it will cause the aperture to be too large, and the edge light cannot be reasonably intercepted, resulting in increased field curvature and the formation of edge distorted images. Therefore, by making 2<D×FNO<3, the ratio relationship between the diameter of the aperture 5 and the aperture number of the optical lens group is reasonably controlled, which can ensure that the optical imaging system 100 has the best light throughput and picture clarity.

[0063] In some specific embodiments of the present invention, the optical effective focal length of the first lens 1 is f1, and the total effective focal length of the optical lens group is f, wherein f1 and f satisfy: -0.35<f / f1<0.35. It should be noted that the first lens 1 provides all optical information from the object space to the image space for the entire optical lens group, and the aperture size and focal length of the first lens 1 determine the acquisition of the object space light information by the optical imaging system 100. When f / f1≥0.35, the sensitivity of the optical imaging system 100 will increase, the processing will be difficult, and the difficulty of correcting the aberrations generated by the first lens 1 will increase, making it difficult to meet the shooting requirements; when f / f1≤-0.35, the aberrations generated by the first lens 1 cannot be corrected. With such a setting, the sensitivity of the optical imaging system 100 can be reduced and the shooting requirements can be met.

[0064] Further, refer to Figure 1-Figure 20, the shortest distance from the image side surface of the fourth lens 4 to the imaging surface parallel to the optical axis is FBL, wherein FBL satisfies: 0.1<FBL / TTL<0.25. With such a configuration, the optical imaging system 100 can take into account the miniaturization of the lens while ensuring that the imaging lens has sufficient focusing space during the installation process of the optical lens group, thereby improving the assembly yield of the optical lens group. Moreover, with the above configuration, the focal depth of the imaging lens can be widened to obtain more depth information.

[0065] In some embodiments of the present invention, the radius of curvature of the object side surface of the first lens 1 is R1, the radius of curvature of the image side surface of the first lens 1 is R2, and the focal length of the first lens 1 is f1, wherein R1, R2 and f1 satisfy: -1.5<(R1+R2) / f1<2. For example, when (R1+R2) / f1≥2.5, the sensitivity of the optical imaging system 100 will be increased, which is not conducive to processing; when (R3+R4) / f1≤-1.5, it is not conducive to the optical imaging system 100 to obtain the object space light information, and the imaging effect cannot meet the design expectations. In this way, by making -1.5<(R1+R2) / f1<2, the imaging effect of the optical imaging system 100 can be further guaranteed, making the captured picture clearer.

[0066] Furthermore, the radius of curvature of the object side surface of the third lens 3 is R6, and the radius of curvature of the image side surface of the third lens 3 is R7, wherein R6 and R7 satisfy: -8<R6 / R7<3.5. Thus, when the lens group satisfies the above formula, the radius of curvature of the object side surface and the radius of curvature of the image side surface of the third lens 3 are more reasonable, the incident angle can be increased to meet the image height requirement of the optical imaging system 100, and the sensitivity of the optical imaging system 100 can be reduced, and the assembly stability can be improved.

[0067] In some embodiments of the present invention, the optical effective focal length of the third lens 3 is f3, and the total effective focal length of the optical lens group is f, wherein f3 and f satisfy: -40<f3 / f<6. For example, when f3 / f≤-40, the total length of the optical imaging system 100 will be too large, and the assembly sensitivity will increase; when f3 / f≥6, it may cause an increase in lens stray light, affecting the imaging quality. Therefore, by making -40<f3 / f<6, the ratio of the optical effective focal length of the third lens 3 to the total effective focal length of the optical lens group can effectively reduce the total length of the optical imaging system 100, which is beneficial to the convergence of light on the imaging surface.

[0068] In some embodiments of the present invention, the radius of curvature of the object side surface of the fourth lens 4 is R8, and the radius of curvature of the image side surface of the fourth lens 4 is R9, wherein R8 and R9 satisfy: 0.4<(R8×R9) / (R8+R9)<0.55. Thus, the longitudinal spherical aberration of the optical imaging system 100 can be reasonably corrected, the distortion aberration and astigmatism can be improved, and the sensitivity of the optical imaging system 100 can be reduced, and the assembly stability can be improved.

[0069] In some embodiments of the present invention, the maximum optical effective area edge thickness of the third lens 3 is ET3, and the thickness of the third lens 3 on the optical axis is CT3, wherein ET3 and CT3 satisfy: 0.2<ET3 / CT3<0.8. Such a setting can ensure sufficient tolerance margin and improve molding yield.

[0070] In some embodiments of the present invention, the radius of curvature of the object side surface of the second lens 2 is R4, and the radius of curvature of the image side surface of the second lens 2 is R5, wherein R4 and R5 satisfy: -15<(R4+R5) / (R4-R5)<90. For example, when (R4+R5) / (R4-R5)>90, the molding yield of the optical lens group will be reduced, and the sensitivity of the optical imaging system 100 will be increased. When (R4+R5) / (R4-R5)<-15, the tolerance will be too large, and the assembly performance of the optical lens group will be reduced. Therefore, by making -15<(R4+R5) / (R4-R5)<90, the sensitivity of the optical imaging system 100 can be reduced, and the processing yield can be guaranteed.

[0071] Optionally, refer to Figure 1 , Figure 3 , Figure 5 , Figure 7 , Fig. 9 , Fig.11 and Fig.13 , Fig.15 , Fig.17 and Fig.19 The aperture 5 is disposed between the first lens 1 and the second lens 2. Thus, the influence of stray light on the image can be further eliminated, thereby improving the quality of the image and further expanding the field of view of the optical imaging system 100.

[0072] Optionally, the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 may be made of plastic, etc. Thus, the optical lens assembly can be made lighter.

[0073] Reference below Figure 1-Figure 20 An optical imaging system 100 is described according to various embodiments of the present invention.

[0074] Embodiment 1,

[0075] In this embodiment, if Figure 1 As shown, the optical imaging system 100 includes a first lens 1, an aperture 5, a second lens 2, a third lens 3 and a fourth lens 4 from the object side to the image side. The longitudinal spherical aberration, astigmatism and distortion curves of the optical imaging system 100 are shown in FIG. Figure 2 .

[0076] The first lens 1 is made of plastic, has negative refractive power, has an object side surface of convex at the optical axis, has an image side surface of concave at the optical axis, has an object side surface of concave at the circumference, has an image side surface of convex at the circumference, and has an aspheric surface on both the object side and the image side surface of the first lens 1. The second lens 2 is made of plastic, has positive refractive power, has an object side surface of convex at the optical axis, has an image side surface of concave at the optical axis, has an object side surface of concave at the circumference, has an image side surface of convex at the circumference, and has an aspheric surface on both the object side and the image side surface of the second lens 2. The third lens 3 is made of plastic, has positive refractive power, has an object side surface of convex at the optical axis, has an image side surface of convex at the optical axis, has an object side surface of convex at the circumference, has an image side surface of convex at the circumference, and has both an object side surface and an image side surface of aspheric surfaces. The fourth lens 4 is made of plastic, has positive refractive power, has an object side surface of convex at the optical axis, has an image side surface of concave at the optical axis, has an object side surface of concave at the circumference, has an image side surface of convex at the circumference, and has both an object side surface and an image side surface of aspheric surfaces. The imaging surface is provided on the image side of the fourth lens 4, and an infrared bandpass filter 6 is provided between the fourth lens 4 and the imaging surface. The infrared bandpass filter 6 is made of glass and does not affect the focal length, and the photosensitive element is provided on the imaging surface. The optical lens group is only for infrared band imaging, and the infrared bandpass filter 6 will filter the imaging light entering the lens, filter out the ultraviolet band and visible light, and only allow infrared light to pass. For example, referring to Table 1, the reference wavelength of the optical lens group is 940nm, which belongs to infrared light wave.

[0077] The detailed optical data of the first embodiment are shown in Table 1, the aspheric coefficients are shown in Table 2, the units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm. The aspheric surface formula is: z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the aspherical vertex, k is the cone constant, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface shape formula.

[0078]

[0079]

[0080]

[0081] In the first embodiment, the distance from the object side surface of the first lens 1 to the imaging surface on the optical axis is TTL, half of the diagonal length of the effective pixel area of ​​the photosensitive element is Imgh, TTL / Imgh=1.06; the effective aperture diameter of the first lens 1 is L, L / Imgh=0.48; the aperture number of the optical lens group is Fno, Fno / TTL=0.31; the diameter of the aperture of the diaphragm 5 is D, TTL / D=2.5, D×FNO=2.47; the total effective focal length of the optical lens group is f, the optical effective focal length of the first lens 1 is f1, TTL / f=1.77, f / f1=-0.12; the shortest distance from the image side surface of the fourth lens 4 to the imaging surface parallel to the optical axis is FBL, FBL / TTL=0.17; the radius of curvature of the object side surface of the first lens 1 is R1, The radius of curvature of the image side surface of the first lens 1 is R2, (R1+R2) / f1=-0.28; the radius of curvature of the object side surface of the third lens 3 is R6, and the radius of curvature of the image side surface of the third lens 3 is R7, R6 / R7=-2.72; the optical effective focal length of the third lens 3 is f3, f3 / f=3.8; the radius of curvature of the object side surface of the fourth lens 4 is R8, and the radius of curvature of the image side surface of the fourth lens 4 is R9, (R8×R9) / (R8+R9)=0.45; the edge thickness of the third lens 3 is ET3, and the center thickness of the third lens 3 is CT3, ET3 / CT3=0.37, the radius of curvature of the object side surface of the second lens 2 is R4, and the radius of curvature of the image side surface of the second lens 2 is R5, (R4+R5) / (R4-R5)=-14.26. Therefore, through the above arrangement, the optical imaging system 100 is miniaturized while achieving high-definition photography, thereby effectively improving the imaging quality.

[0082] Embodiment 2:

[0083] like Figure 3 and Figure 4 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, except that: the third lens 3 has a negative refractive power,

[0084] Detailed optical data of the second embodiment are shown in Table 3, and its aspheric coefficients are shown in Table 4. The units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0085]

[0086]

[0087]

[0088] In Example 2, TTL / Imgh=1.06, L / Imgh=0.49, Fno / TTL=0.31, TTL / D=2.54, D×FNO=2.44, TTL / f=1.75, f / f1=-0.24, FBL / TTL=0.17, (R1+R2) / f1=-1.27, R6 / R7=3.2, f3 / f=-35.26, (R8×R9) / (R8+R9)=0.44, ET3 / CT3=0.71, (R4+R5) / (R4-R5)=-3.82.

[0089] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0090] Embodiment 3,

[0091] like Figure 5 and Figure 6 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the first lens 1 has a positive refractive power, and the fourth lens 4 has a negative refractive power.

[0092] Detailed optical data of Example 3 are shown in Table 5, and its aspheric coefficients are shown in Table 6. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0093]

[0094]

[0095] In Example 3, TTL / Imgh=1.06, L / Imgh=0.48, Fno / TTL=0.31, TTL / D=2.49, D×FNO=2.47, TTL / f=1.74, f / f1=0.07, FBL / TTL=0.17, (R1+R2) / f1=0.60, R6 / R7=-5.33, f3 / f=1.09, (R8×R9) / (R8+R9)=0.44, ET3 / CT3=0.27, (R4+R5) / (R4-R5)=60.67.

[0096] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0097] Embodiment 4:

[0098] like Figure 7 and Figure 8 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the curvature radius of each surface of the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 is different from that of the first embodiment.

[0099] Detailed optical data of Example 4 are shown in Table 7, its aspheric coefficients are shown in Table 8, the units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0100]

[0101]

[0102]

[0103] In Example 4, TTL / Imgh=1.06, L / Imgh=0.52, Fno / TTL=0.28, TTL / D=2.22, D×FNO=2.48, TTL / f=1.79, f / f1=-0.33, FBL / TTL=0.17, (R1+R2) / f1=-1.32, R6 / R7=-3.49, f3 / f=3.80, (R8×R9) / (R8+R9)=0.45, ET3 / CT3=0.40, (R4+R5) / (R4-R5)=-6.62.

[0104] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0105] Embodiment 5,

[0106] like Fig. 9 and Fig.10 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the curvature radius of each surface of the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 is different from that of the first embodiment.

[0107] Detailed optical data of Example 5 are shown in Table 9, its aspheric coefficients are shown in Table 10, the units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0108]

[0109]

[0110]

[0111] In Example 5, TTL / Imgh=1.06, L / Imgh=0.55, Fno / TTL=0.27, TTL / D=2.10, D×FNO=2.53, TTL / f=1.79, f / f1=-0.26, FBL / TTL=0.17, (R1+R2) / f1=-1.01, R6 / R7=-7.47, f3 / f=4.60, (R8×R9) / (R8+R9)=0.46, ET3 / CT3=0.41, (R4+R5) / (R4-R5)=-4.71.

[0112] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0113] Embodiment 6,

[0114] like Fig.11 and Fig.12 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the curvature radius of each surface of the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4 is different from that of the first embodiment.

[0115] The detailed optical data of Example 6 are shown in Table 11, the aspheric coefficients are shown in Table 12, the units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0116]

[0117]

[0118] In Example 6, TTL / Imgh=1.06, L / Imgh=0.55, Fno / TTL=0.25, TTL / D=2.07, D×FNO=2.35, TTL / f=1.79, f / f1=-0.25, FBL / TTL=0.17, (R1+R2) / f1=-1.04, R6 / R7=-4.76, f3 / f=4.54, (R8×R9) / (R8+R9)=0.46, ET3 / CT3=0.36, (R4+R5) / (R4-R5)=-4.71.

[0119] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0120] Embodiment 7,

[0121] like Fig.13 and Fig.14 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the first lens 1 has positive refractive power, and the object side surface of the first lens 1 is convex at the circumference.

[0122] The detailed optical data of Example 7 are shown in Table 13, the aspheric coefficients are shown in Table 14, the units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0123]

[0124]

[0125]

[0126] In Example 7, TTL / Imgh=1.21, L / Imgh=0.55, Fno / TTL=0.27, TTL / D=2.59, D×FNO=2.70, TTL / f=1.74, f / f1=0.06, FBL / TTL=0.17, (R1+R2) / f1=0.49, R6 / R7=-3.32, f3 / f=1.58, (R8×R9) / (R8+R9)=0.48, ET3 / CT3=0.51, (R4+R5) / (R4-R5)=87.21.

[0127] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0128] Embodiment 8,

[0129] like Fig.15 and Fig.16 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the first lens 1 has a positive refractive power, the third lens 3 has a negative refractive power, the object side surface of the third lens 3 is a concave surface at the optical axis, and the object side surface of the third lens 3 is a concave surface at the circumference.

[0130] The detailed optical data of Example 8 are shown in Table 15, and its aspheric coefficients are shown in Table 16. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0131]

[0132]

[0133]

[0134] In Example 8, TTL / Imgh=1.05, L / Imgh=0.59, Fno / TTL=0.27, TTL / D=1.95, D×FNO=2.68, TTL / f=1.60, f / f1=0.21, FBL / TTL=0.16, (R1+R2) / f1=0.38, R6 / R7=0.80, f3 / f=-14.47, (R8×R9) / (R8+R9)=0.49, ET3 / CT3=0.63, (R4+R5) / (R4-R5)=-4.02.

[0135] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0136] Embodiment 9,

[0137] like Fig.17 and Fig.18 As shown, the structure of this embodiment is substantially the same as that of the first embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the first lens 1 has positive refractive power, and the object side surface of the first lens 1 is convex at the circumference.

[0138] The detailed optical data of Example 9 are shown in Table 17, and its aspheric coefficients are shown in Table 18. The units of the radius of curvature, thickness and focal length are millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0139]

[0140]

[0141] In Example 9, TTL / Imgh=1.06, L / Imgh=0.50, Fno / TTL=0.31, TTL / D=2.60, D×FNO=2.37, TTL / f=1.75, f / f1=0.11, FBL / TTL=0.17, (R1+R2) / f1=1.59, R6 / R7=-3.09, f3 / f=1.58, (R8×R9) / (R8+R9)=0.41, ET3 / CT3=0.48, (R4+R5) / (R4-R5)=35.63.

[0142] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the first embodiment in other structures, and thus will not be described in detail here.

[0143] Embodiment 10,

[0144] like Fig.19 and Fig. 20 As shown, the structure of this embodiment is substantially the same as that of the ninth embodiment, wherein the same components are marked with the same reference numerals, and the difference is that the second lens 2 has a negative refractive power, the image side surface of the first lens 1 is a convex surface at the optical axis, the object side surface of the first lens 1 is a concave surface at the circumference, and the image side surface of the third lens 3 is a concave surface at the circumference.

[0145] The detailed optical data of Example 10 are shown in Table 19, the aspheric coefficients are shown in Table 20, the units of the radius of curvature, thickness and focal length are in millimeters, and the reference wavelength of the optical imaging system 100 is 940 nm.

[0146]

[0147]

[0148]

[0149] In Example 10, TTL / Imgh=1.06, L / Imgh=0.50, Fno / TTL=0.31, TTL / D=2.60, D×FNO=2.37, TTL / f=1.75, f / f1=0.11, FBL / TTL=0.17, (R1+R2) / f1=1.59, R6 / R7=-3.09, f3 / f=1.58, (R8×R9) / (R8+R9)=0.41, ET3 / CT3=0.48, (R4+R5) / (R4-R5)=35.63.

[0150] The optical imaging system 100 of this embodiment is similar to the optical imaging system 100 of the ninth embodiment in other structures, and thus will not be described in detail here.

[0151] The imaging device (not shown) according to the second embodiment of the present invention comprises a photosensitive element and an optical imaging system 100. The optical imaging system 100 is the optical imaging system 100 according to the first embodiment of the present invention.

[0152] The imaging device according to the embodiment of the present invention adopts the above-mentioned optical imaging system 100, so the number of lenses is small, which is conducive to miniaturization design, and can achieve high-definition shooting, thereby improving the overall performance of the imaging device.

[0153] The electronic device (not shown) according to the third aspect of the present invention comprises a housing (not shown) and an imaging device. The imaging device is the imaging device according to the second aspect of the present invention, and the imaging device is mounted on the housing and exposed from the housing.

[0154] The electronic device according to the embodiment of the present invention adopts the above-mentioned imaging device, so that the electronic device has the advantages of both miniaturization and high definition, and fully meets the needs of users.

[0155] Other structures and operations of the electronic device according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0156] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0157] In the description of the present invention, “first feature”, “second feature”, “third feature” and “fourth feature” may include one or more of the features.

[0158] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0159] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An optical imaging system, characterized in that: include: An optical lens group, wherein the optical lens group has four lenses with refractive power, and the optical lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence along the axial direction, wherein the first lens, the second lens, the third lens, and the fourth lens are all plastic lenses, and the first lens, the second lens, the third lens, and the fourth lens all have refractive power, the object side surface of the first lens is a convex surface at the optical axis, the object side surface of the second lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis, and the second lens is provided with at least one inflection point, and the object side surface of the fourth lens is a convex surface at the optical axis, and the image side surface is a concave surface at the optical axis; Wherein, the optical imaging system satisfies: TTL / Imgh<1.5 and 0.3<L / Imgh<0.7; Wherein, TTL is the distance from the object side of the first lens to the imaging plane on the optical axis, Imgh is half the diagonal length of the effective pixel area on the imaging plane, L is the effective aperture diameter of the first lens, and f is the total effective focal length of the optical lens group.

2. The optical imaging system according to claim 1, characterized in that: The aperture number of the optical lens group is Fno, wherein Fno satisfies: Fno / TTL<0.4mm -1 。 3. The optical imaging system according to claim 1, characterized in that: The optical lens group further includes a stop, the diameter of the stop aperture is D, wherein D satisfies: 1.5<TTL / D<3.

0.

4. The optical imaging system according to claim 1, characterized in that: The total effective focal length of the optical lens assembly is f, where f satisfies: 1.0<TTL / f<2.

0.

5. The optical imaging system according to claim 1, characterized in that: The optical lens group further includes a stop, the diameter of the stop aperture is D, and the aperture number of the optical lens group is Fno, wherein D and Fno satisfy: 2mm<D×FNO<3mm.

6. The optical imaging system according to claim 1, characterized in that: The optical effective focal length of the first lens is f1, and the total effective focal length of the optical lens group is f, wherein f1 and f satisfy: -0.35<f / f1<0.

35.

7. The optical imaging system according to claim 1, characterized in that: The shortest distance from the image side surface of the fourth lens to the imaging plane parallel to the optical axis is FBL, where the FBL satisfies: 0.1<FBL / TTL<0.

25.

8. The optical imaging system according to claim 1, characterized in that: The radius of curvature of the object side surface of the first lens is R1, the radius of curvature of the image side surface of the first lens is R2, and the focal length of the first lens is f1, wherein R1, R2 and f1 satisfy: -1.5<(R1+R2) / f1<2.

9. The optical imaging system according to claim 1, characterized in that: The radius of curvature of the object side surface of the third lens is R6, and the radius of curvature of the image side surface of the third lens is R7, wherein R6 and R7 satisfy: -8<R6 / R7<3.

5.

10. The optical imaging system according to claim 1, characterized in that: The optical effective focal length of the third lens is f3, and the total effective focal length of the optical lens group is f, wherein f3 and f satisfy: -40<f3 / f<6.

11. The optical imaging system according to claim 1, characterized in that: The curvature radius of the object side surface of the fourth lens is R8, and the curvature radius of the image side surface of the fourth lens is R9, wherein R8 and R9 satisfy: 0.4<(R8×R9) / (R8+R9)<0.

55.

12. The optical imaging system according to claim 1, characterized in that: The maximum optical effective area edge thickness of the third lens is ET3, and the thickness of the third lens on the optical axis is CT3, wherein ET3 and CT3 satisfy: 0.2<ET3 / CT3<0.

8.

13. The optical imaging system according to claim 1, characterized in that: The radius of curvature of the object side surface of the second lens is R4, and the radius of curvature of the image side surface of the second lens is R5, wherein R4 and R5 satisfy: -15<(R4+R5) / (R4-R5)<90.

14. An imaging device, characterized in that: include: Photosensitive element; An optical imaging system, wherein the optical imaging system is the optical imaging system according to any one of claims 1-13.

15. An electronic device, characterized in that: include: case; An imaging device, wherein the imaging device is the imaging device according to claim 14, and the imaging device is mounted on the housing and exposed from the housing.

Images