Industrial zoom optical imaging system and camera module applied by same

Abstract

The invention provides an industrial zoom optical imaging system and a camera module applying the same, and the system is composed of eight lenses, the first lens has positive focal power, the second lens has negative focal power, the third lens has negative focal power, the fourth lens has positive focal power, the fifth lens has positive focal power, and the sixth lens has negative focal power. The seventh lens has positive focal power, the eighth lens has positive focal power, the resolution ratio and the imaging definition of the optical imaging system are improved by selecting a proper number of lenses and reasonably configuring the refractive power and the surface shape of each lens, and the fourth lens can move along the optical axis and can realize an internal focusing function under different object distances. Target details can be well shot, so that the requirement of high-definition imaging of an industrial optical lens under a large-range object distance can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging, in particular to an industrial zoom optical imaging system and an application of a camera module thereof. BACKGROUND

[0002] Industrial lenses are the frontmost components for industrial automation systems to obtain image data, determine the accuracy of the obtained information, and play an important role in machine vision systems. High-quality industrial lenses can help industrial equipment complete complex and delicate tasks, thereby improving product quality. With the promotion of intelligent manufacturing, higher requirements are put forward for the efficiency of industrial automation. When dealing with multi- distance camera targets, the use of conventional single-distance camera lenses requires the addition of mechanical moving components to achieve large-range clear imaging, thereby increasing the operation process of automated equipment and production costs.

[0003] Therefore, there is an urgent need to provide a camera lens that takes into account both imaging quality and large-range distance camera imaging. SUMMARY

[0004] The present application aims to provide an industrial zoom optical imaging system that takes into account both imaging quality and large-range distance camera imaging, thereby reducing the physical space required for moving components of automated equipment, and thus improving production efficiency.

[0005] An industrial zoom optical imaging system, sequentially comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens along an optical axis from an object plane to an image plane; The first lens has positive focal power, its object side surface is convex, and its image side surface is concave; The second lens has negative focal power, its object side surface is convex, and its image side surface is concave; The third lens has negative focal power, its object side surface is convex, and its image side surface is concave; The fourth lens has positive focal power, its object side surface is convex, and its image side surface is convex; The fifth lens has positive focal power, its object side surface is concave, and its image side surface is convex; The sixth lens has negative focal power, its object side surface is concave, and its image side surface is convex; The seventh lens has positive focal power, its object side surface is convex, and its image side surface is convex; The eighth lens has positive focal power, and its image side surface is convex.

[0006] Compared with the prior art, the present application has the following advantages: The application provides an industrial zoom optical imaging system and an application of a camera module thereof, which is composed of eight lenses, and the resolution and imaging definition of the optical imaging system are improved by selecting a proper number of lenses and reasonably configuring the refractive power and surface shape of each lens, wherein the fourth lens can be moved along the optical axis to realize an inner focusing function at different object distances, and target details are better captured to meet the requirement of high-definition imaging of the industrial optical lens at a large range of object distances. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced.

[0008] Figures 1-3 is a structural schematic diagram of the optical system or camera module of the embodiment 1 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 4-6 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical system or camera module of the embodiment 1 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 7-9 is a structural schematic diagram of the optical system or camera module of the embodiment 2 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 10-12 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical system or camera module of the embodiment 2 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 13-15 is a structural schematic diagram of the optical system or camera module of the embodiment 3 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 16-18 is an on-axis chromatic aberration, astigmatism and distortion curve of the optical system or camera module of the embodiment 3 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 19-21 is a structural schematic diagram of the optical system or camera module of the embodiment 4 of the present application when the object distance M is 100mm at the near end, 400mm at the near end, and infinity at the far end, respectively; Figures 22-24are axial chromatic aberration, astigmatism and distortion curves of the optical system or camera module of Embodiment 4 of the present application when the object distance M is 100 mm at the near end, 400 mm at the near end, and infinity at the far end, respectively; Figures 25-27 are structural schematic diagrams of the optical system or camera module of Embodiment 5 of the present application when the object distance M is 100 mm at the near end, 400 mm at the near end, and infinity at the far end, respectively; Figures 28-30 are axial chromatic aberration, astigmatism and distortion curves of the optical system or camera module of Embodiment 5 of the present application when the object distance M is 100 mm at the near end, 400 mm at the near end, and infinity at the far end, respectively. DETAILED DESCRIPTION

[0009] The present application provides an industrial zoom optical imaging system, which comprises, in order from the object side to the image side along the optical axis, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, and an optical filter IR. A stop STO is disposed between the fourth lens E4 and the fifth lens E5. The fourth lens E4 is movable along the optical axis. The first lens E1, the second lens E2, the fourth lens E4, and the eighth lens E8 are spherical glass lenses. The third lens E3, the fifth lens E5, the sixth lens E6, and the seventh lens E7 are aspherical plastic lenses, and are all separated by air. The first lens E1 has positive refractive power, and its object side surface is convex and its image side surface is concave. The second lens E2 has negative refractive power, and its object side surface is convex and its image side surface is concave. The third lens E3 has negative refractive power, and its object side surface is convex and its image side surface is concave. The fourth lens E4 has positive refractive power, and its object side surface is convex and its image side surface is convex. The fifth lens E5 has positive refractive power, and its object side surface is concave and its image side surface is convex. The sixth lens E6 has negative refractive power, and its object side surface is concave and its image side surface is convex. The seventh lens E7 has positive refractive power, and its object side surface is convex and its image side surface is convex. The eighth lens E8 has positive refractive power, and its image side surface is convex. The industrial zoom optical imaging system has an object distance range of 100 mm to infinity. The effective focal length f of the industrial zoom optical imaging system can be between 6.8 mm and 9.2 mm. The full field of view FOV of the industrial zoom optical imaging system can be between 63.9° and 79.6°. The distance TTL from the object side surface of the first lens to the image plane on the optical axis is less than 56.6 mm.

[0010] The optical system of the embodiment of the present application is composed of 8 lenses. By selecting a proper number of lenses and reasonably configuring the refractive power and surface shape of each lens, the resolution and imaging clarity of the optical imaging system are improved. The fourth lens can move along the optical axis to realize the inner focusing function at different object distances, and better capture the target details to meet the requirements of high-definition imaging of industrial optical lenses at a wide range of object distances.

[0011] Further, the optical system satisfies the following relationship: 15.9 < TTL*Fnoi / fi < 19.9, 15.4 < TTL*Fnoj / fj < 19.3, 15.2 < TTL*Fnok / fk < 19.1; wherein TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis, Fno is the effective F number of the optical imaging system, f is the effective focal length of the optical imaging system, fi is the effective focal length of the optical imaging system at a near object distance of 100 mm, fj is the effective focal length of the optical imaging system at an intermediate object distance of 400 mm, fk is the effective focal length of the optical imaging system at an infinite object distance, Fnoi is the effective F number of the optical imaging system at a near object distance of 100 mm, Fnoj is the effective F number of the optical imaging system at an intermediate object distance of 400 mm, Fnok is the effective F number of the optical imaging system at an infinite object distance. This relationship reflects the constraints of the optical system on the total optical length, effective focal length and light transmission characteristics, so that the optical system meets the light collection capability while limiting the system length, ensuring that the optical system has good light transmission characteristics and compact structure. When the lower limit of the relationship is exceeded, the Fno / f is further reduced to ensure the compact structure of the optical system, and it is difficult for the optical system to obtain a larger imaging depth of field range; when the upper limit of the relationship is exceeded, it is difficult for the optical system to obtain good light collection capability.

[0012] Further, the optical system satisfies the following relationship: 9.0 < HFOVi / EPDi < 14.2, 8.7 < HFOVj / EPDj < 13.7, 8.6 < HFOVk / EPDk < 13.5; wherein HFOV is half of the maximum field of view angle of the optical imaging system, EPD is the entrance pupil diameter of the optical imaging system, HFOVi is half of the maximum field of view angle of the optical imaging system at the near object distance of 100 mm, HFOVj is half of the maximum field of view angle of the optical imaging system at the intermediate object distance of 400 mm, HFOVk is half of the maximum field of view angle of the optical imaging system at the infinite object distance, EPDi is the entrance pupil diameter of the optical imaging system at the near object distance of 100 mm, EPDj is the entrance pupil diameter of the optical imaging system at the intermediate object distance of 400 mm, and EPDk is the entrance pupil diameter of the optical imaging system at the infinite object distance. The relationship reflects the constraint of the optical system on the field of view angle and the light transmission characteristics, so that the optical system meets the demand of large field of view angle while limiting the light transmission aperture, ensuring that the optical system has the characteristics of large field of view angle and miniaturization. When the lower limit of the relationship is exceeded, on the basis of ensuring that the field of view angle of the optical lens is a large field of view angle, the light transmission aperture is further increased, which increases the aperture of the optical lens and is not conducive to the miniaturization of the optical lens; when the upper limit of the relationship is exceeded, the optical lens is difficult to obtain good light collection capability.

[0013] Further, the optical system satisfies the following relationship: 5.8 < f1*f2 / (f5*f6) < 7.3; wherein f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f5 is the effective focal length of the fifth lens, and f6 is the effective focal length of the sixth lens. By limiting the effective focal lengths of the first lens, the second lens, the fifth lens, and the sixth lens of the optical imaging system within a reasonable range, the contribution of the first lens, the second lens, the fifth lens, and the sixth lens to spherical aberration and coma can be effectively constrained, and after balancing, the sensitivity is at a reasonable level.

[0014] Further, the optical system satisfies the following relationship: 17.8 < R1-R4 / (R2-R3) < 19.4; wherein R1 is the curvature radius of the object side surface of the first lens, R2 is the curvature radius of the image side surface of the first lens, R3 is the curvature radius of the object side surface of the second lens, and R4 is the curvature radius of the image side surface of the second lens. By controlling the curvature radii of the object side surface and the image side surface of the first lens and the curvature radii of the object side surface and the image side surface of the second lens within a reasonable range, the light deflection angle of the optical system can be small, and thus the lens is easy to process.

[0015] Further, the optical system satisfies the following relationship: 6.5 < (R5+R6+R7) / |f3| < 9.4; wherein R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, R7 is the curvature radius of the object side surface of the fourth lens, and f3 is the effective focal length of the third lens. By restricting the curvature radius of the object side surface, the image side surface of the third lens and the object side surface of the fourth lens, the power of the third lens is adjusted to avoid excessive divergence of light rays by the third lens, and at the same time, it is helpful to restrict the surface shape of the image side surface of the third lens to avoid excessive curvature which affects the processability of the third lens. In addition, by satisfying the above relationship, the correction of high-order aberrations can be further enhanced on the basis of reducing the third-order aberrations such as spherical aberration, coma, and field curvature, and the tolerance sensitivity of the optical system is reduced. When the upper limit of the above relationship is exceeded, the third lens diverges the light rays too much, resulting in the surface shape of the image side surface of the third lens being too curved, which is not conducive to the processability of the third lens. When the lower limit of the above relationship is exceeded, the third lens is not sufficient to diverge the light rays, which is not conducive to the correction of aberrations of the optical system and affects the tolerance sensitivity of the optical system.

[0016] Further, the optical system satisfies the following relationship: 2.5 < |(R9+R10) / (2*f4)| < 4.1; wherein R9 is the curvature radius of the object side surface of the fifth lens, R10 is the curvature radius of the image side surface of the fifth lens, and f4 is the effective focal length of the fourth lens. By restricting the curvature radius of the object side surface and the image side surface of the fifth lens, the power of the fourth lens is adjusted to avoid excessive concentration of the power of the fourth lens, and at the same time, it is helpful to restrict the surface shape of the object side surface of the fifth lens to avoid excessive curvature which affects the processability of the fifth lens. When the upper limit of the above relationship is exceeded, the power of the fourth lens is too large, resulting in the surface shape of the image side surface of the fifth lens being too curved, which is not conducive to the processability of the fifth lens. When the lower limit of the above relationship is exceeded, the power of the fourth lens is not sufficient, which is not conducive to the correction of aberrations of the optical system and affects the tolerance sensitivity of the optical system.

[0017] Further, the optical system satisfies the following relationships: 9.4 < (f12-f34i) / f23 < 11.1, 9.6 < (f12-f34j) / f23 < 11.5, 9.7 < (f12-f34k) / f23 < 11.7, where f12 is the combined focal length of the first lens and the second lens, f23 is the combined focal length of the second lens and the third lens, f34 is the combined focal length of the third lens and the fourth lens, f34i is the combined focal length of the third lens and the fourth lens of the optical imaging system at a near object distance of 100 mm, f34j is the combined focal length of the third lens and the fourth lens of the optical imaging system at an intermediate object distance of 400 mm, and f34k is the combined focal length of the third lens and the fourth lens of the optical imaging system at an infinite object distance. The first lens and the fourth lens provide positive refractive power for the optical system, and the second lens and the third lens provide negative refractive power for the optical system. Controlling the relationship between the combined focal lengths of adjacent two lenses within a reasonable range is conducive to mutual correction of aberrations and improves imaging quality.

[0018] Further, the optical system satisfies the following relationships: 4.2 < ΣCT / CT4 < 6.2, where ΣCT is the sum of the central thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens on the optical axis, and CT4 is the central thickness of the fourth lens on the optical axis. By limiting the above conditional expression within a reasonable range, the central thickness of the fourth lens on the optical axis can be effectively distributed, which helps to improve imaging quality and smoothly transition on each lens during light transmission, thereby reducing the manufacturing difficulty of the lens.

[0019] Embodiment One, The following refers to Figures 1-6 An optical imaging system according to Embodiment 1 of the present application is described. Figure 1 , Figure 2 , Figure 3 Structural schematic diagrams of the optical imaging system according to Embodiment 1 of the present application at object distances of 100 mm, 400 mm, and infinity are shown respectively. Figure 4 , Figure 5 , Figure 6 Axial chromatic aberration, astigmatism, and distortion curves of the optical imaging system according to Embodiment 1 of the present application at object distances of 100 mm, 400 mm, and infinity are shown respectively. Axial chromatic aberration represents the deviation of the convergent focal points of light rays of different wavelengths after passing through the lens; astigmatism represents the meridional image surface curvature and sagittal image surface curvature; and distortion represents the distortion size values corresponding to different image heights.

[0020] As Figures 1-3As shown, the optical imaging system according to the exemplary embodiment of the present application comprises, in order from the object side to the image side along the optical axis, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4 movable along the optical axis, an STO, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, and an imaging surface S18.

[0021] The first lens E1 has positive refractive power, the object side surface S1 is convex, and the image side surface S2 is concave.

[0022] The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave.

[0023] The third lens E3 has negative refractive power, the object side surface S5 is convex, and the image side surface S6 is concave.

[0024] The fourth lens E4 has positive refractive power, the object side surface S7 is convex, and the image side surface S8 is convex.

[0025] The fifth lens E5 has positive refractive power, the object side surface S9 is concave, and the image side surface S10 is convex.

[0026] The sixth lens E6 has negative refractive power, the object side surface S10 is concave, and the image side surface S11 is convex.

[0027] The seventh lens E7 has positive refractive power, the object side surface S12 is convex, and the image side surface S13 is convex.

[0028] The eighth lens E8 has positive refractive power, the image side surface S14 is convex, and the image side surface S15 is convex.

[0029] The filter IR has an object side surface S16 and an image side surface S17. Light from the object passes through each surface S1 to S17 in order and is finally imaged on the imaging surface S18.

[0030] Table 1 shows a basic parameter table of the optical imaging system 1001, the optical imaging system 1002, and the optical imaging system 1003 of Embodiment 1, wherein the units of the radius of curvature and the thickness / distance are millimeters (mm).

[0031] Table 1

[0032] In Embodiment 1, as Figures 1-3As shown, the fourth lens E4 can be displaced along the optical axis, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 14.9776 mm, and the sum P+T of the distance T between the image side surface S8 of the fourth lens E4 and the stop surface STO on the optical axis and the distance Q between the image side surface S15 of the eighth lens E8 and the object side surface S16 of the filter IR on the optical axis is 9.4491 mm. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 7.2656 mm when the object distance M of the optical imaging system 1001 is 100 mm at the near end. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.8181 mm when the object distance M of the optical imaging system 1002 is 400 mm at the middle. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.6386 mm when the object distance M of the optical imaging system 1003 is infinite at the far end. Figure 1 As shown, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 7.2656 mm when the object distance M of the optical imaging system 1001 is 100 mm at the near end. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.8181 mm when the object distance M of the optical imaging system 1002 is 400 mm at the middle. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.6386 mm when the object distance M of the optical imaging system 1003 is infinite at the far end. Figure 2 As shown, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 7.2656 mm when the object distance M of the optical imaging system 1001 is 100 mm at the near end. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.8181 mm when the object distance M of the optical imaging system 1002 is 400 mm at the middle. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.6386 mm when the object distance M of the optical imaging system 1003 is infinite at the far end. Figure 3 As shown, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 7.2656 mm when the object distance M of the optical imaging system 1001 is 100 mm at the near end. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.8181 mm when the object distance M of the optical imaging system 1002 is 400 mm at the middle. As shown in Table 1, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 6.6386 mm when the object distance M of the optical imaging system 1003 is infinite at the far end.

[0033] In Table 2, the object side surface and the image side surface of any one of the third lens E3, the fifth lens E5, the sixth lens E6, and the seventh lens E7 are aspherical surfaces, and the surface shape of each aspherical lens can be defined by, but is not limited to, the following aspherical surface formula:

[0034] wherein Z is the sag of the aspherical surface at a position with a radial radius of r along the optical axis direction, from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface, c=1 / R (i.e., the paraxial curvature c is the inverse of the curvature radius R in Table 1); K is the conic coefficient; A n is the aspherical coefficient. Table 2 shows the conic coefficient K and the high-order coefficients A4, A6, A8, A 10 , A 12 , A 14 , A 16 , A 18 , and A 20 that can be used in the first embodiment.

[0035] Table 2

[0036] Embodiment Two, The optical imaging system according to Embodiment 2 of the present application is described below with reference to Figures 7-12 Figure 7 , Figure 8 ,​Figure 9 Schematic diagrams of the optical imaging system according to Embodiment 2 of this application are shown at object distances of 100mm, 400mm, and infinity. Figure 10 , Figure 11 , Figure 12 The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging system according to Embodiment 2 of this application are shown respectively at object distances of 100 mm, 400 mm, and infinity.

[0037] like Figures 7-9 As shown, the optical imaging system according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, STO, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter IR, and an imaging surface S18.

[0038] The first lens E1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0039] The second lens E2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0040] The third lens E3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0041] The fourth lens E4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.

[0042] The fifth lens E5 has positive optical power, its object side S9 is concave, and its image side S10 is convex.

[0043] The sixth lens E6 has negative optical power, its object side S10 is concave, and its image side S11 is convex.

[0044] The seventh lens E7 has positive optical power, its object side S12 is convex, and its image side S13 is convex.

[0045] The eighth lens E8 has positive optical power, and its image-side surface S14 is convex, and its image-side surface S15 is convex.

[0046] The filter IR has an object-side surface S16 and an image-side surface S17. Light from the object passes sequentially through each surface S1 to S17 and is finally imaged onto the imaging surface S18.

[0047] Table 3 shows the basic parameters of optical imaging systems 2001, 2002 and 2003 of Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0048] Table 3

[0049] In embodiment 2, as shown in Figures 7-9 , the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 7.6385 mm, the sum P+T of the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis and the distance T of the image side surface S8 of the fourth lens E4 relative to the diaphragm surface STO on the optical axis is 15.2501 mm, and the sum Q+S of the distance Q of the image side surface S15 of the eighth lens E8 relative to the object side surface S16 of the filter IR on the optical axis and the distance S of the image side surface S17 of the filter IR relative to the imaging surface S18 on the optical axis is 8.8622 mm. As shown in Figure 7 , when the object distance M of the optical imaging system 2001 is 100 mm at the near end, the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 7.6385 mm. As shown in Figure 8 , when the object distance M of the optical imaging system 2002 is 400 mm at the middle, the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 7.2015 mm. As shown in Figure 9 , when the object distance M of the optical imaging system 2003 is infinite at the far end, the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 7.0239 mm.

[0050] Table 4 shows the high-order term coefficients of the aspherical surfaces in embodiment 2, wherein each aspherical surface can be defined by the formula (1) given in embodiment 1.

[0051] Table 4

[0052] In embodiment 3, The optical imaging system according to embodiment 3 of the present application is described below with reference to Figures 13-18 . Figure 13 , Figure 14 , Figure 15 respectively show the structural schematic diagrams of the optical imaging system according to embodiment 3 of the present application when the object distance is 100 mm, 400 mm and infinite. Figure 16 , Figure 17 , Figure 18 respectively show the axial chromatic aberration, astigmatism and distortion curves of the optical imaging system according to embodiment 3 of the present application when the object distance is 100 mm, 400 mm and infinite.

[0053] As shown in Figures 13-15As shown, the optical imaging system according to the exemplary embodiment of the present application comprises, in order from the object side to the image side along the optical axis, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4 movable along the optical axis, an STO, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, and an imaging surface S18.

[0054] The first lens E1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave.

[0055] The second lens E2 has negative refractive power, its object side surface S3 is convex, and its image side surface S4 is concave.

[0056] The third lens E3 has negative refractive power, its object side surface S5 is convex, and its image side surface S6 is concave.

[0057] The fourth lens E4 has positive refractive power, its object side surface S7 is convex, and its image side surface S8 is convex.

[0058] The fifth lens E5 has positive refractive power, its object side surface S9 is concave, and its image side surface S10 is convex.

[0059] The sixth lens E6 has negative refractive power, its object side surface S10 is concave, and its image side surface S11 is convex.

[0060] The seventh lens E7 has positive refractive power, its object side surface S12 is convex, and its image side surface S13 is convex.

[0061] The eighth lens E8 has positive refractive power, its image side surface S14 is convex, and its image side surface S15 is convex.

[0062] The filter IR has an object side surface S16 and an image side surface S17. Light from the object passes through each surface S1 to S17 in order and is finally imaged on the imaging surface S18.

[0063] Table 5 shows the basic parameter table of the optical imaging system 3001, the optical imaging system 3002, and the optical imaging system 3003 of Example 3, wherein the units of the radius of curvature and the thickness / distance are millimeters (mm).

[0064] Table 5

[0065] In Example 3, as Figures 13-15As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end. Figure 13 As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end. Figure 14 As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end. Figure 15 As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end.

[0066] Table 6 shows the high-order term coefficients of the aspherical surfaces used in the embodiment 3, wherein each aspherical surface can be defined by the formula (1) given in the embodiment 1.

[0067] Table 6

[0068] Embodiment Four, The following refers to Figures 19-24 An optical imaging system according to the embodiment 4 of the present application is described. Figure 19 , Figure 20 , Figure 21 FIGS. 9, 10 and 11 respectively show the structure schematic diagrams of the optical imaging system according to the embodiment 4 of the present application when the object distance is 100 mm, 400 mm and infinite. Figure 22 , Figure 23 , Figure 24 FIGS. 12, 13 and 14 respectively show the axial chromatic aberration, astigmatism and distortion curves of the optical imaging system according to the embodiment 4 of the present application when the object distance is 100 mm, 400 mm and infinite.

[0069] As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end. Figures 19-21 As shown in FIG. 6, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.8942 mm when the object distance M of the optical imaging system 3001 is 100 mm at the near end. As shown in FIG. 7, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.4736 mm when the object distance M of the optical imaging system 3002 is 400 mm at the middle. As shown in FIG. 8, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 along the optical axis is 7.3022 mm when the object distance M of the optical imaging system 3003 is infinite at the far end.

[0070] The first lens E1 has positive focal power, its object side surface S1 is convex, and its image side surface S2 is concave.

[0071] The second lens E2 has negative focal power, its object side surface S3 is convex, and its image side surface S4 is concave.

[0072] The third lens E3 has negative focal power, its object side surface S5 is convex, and its image side surface S6 is concave.

[0073] The fourth lens E4 has positive focal power, its object side surface S7 is convex, and its image side surface S8 is convex.

[0074] The fifth lens E5 has positive focal power, its object side surface S9 is concave, and its image side surface S10 is convex.

[0075] The sixth lens E6 has negative focal power, its object side surface S10 is concave, and its image side surface S11 is convex.

[0076] The seventh lens E7 has positive focal power, its object side surface S12 is convex, and its image side surface S13 is convex.

[0077] The eighth lens E8 has positive focal power, its image side surface S14 is concave, and its image side surface S15 is convex.

[0078] The filter IR has an object side surface S16 and an image side surface S17. Light from the object passes sequentially through each surface S1 to S17 and is ultimately imaged on the image plane S18.

[0079] Table 7 shows a table of basic parameters of the optical imaging system 4001, the optical imaging system 4002, and the optical imaging system 4003 of Example 4, wherein the units of the radius of curvature and the thickness / distance are millimeters (mm).

[0080] Table 7

[0081] In Example 4, as shown in Table 7, the fourth lens E4 can be displaced along the optical axis, the distance P between the image side surface S6 of the third lens E3 and the object side surface S7 of the fourth lens E4 on the optical axis is 15.7515 mm, the sum P+T of the distance T between the image side surface S8 of the fourth lens E4 and the stop plane STO on the optical axis and the distance Q between the image side surface S15 of the eighth lens E8 and the object side surface S16 of the filter IR on the optical axis is 8.8059 mm, and the distance S between the image side surface S17 of the filter IR and the image plane S18 on the optical axis is 0.0000 mm. Figures 19-21 Figure 19 ​As shown, when the object distance M of the optical imaging system 4001 is 100mm at the near end, the distance P of the image-side surface S6 of the third lens E3 relative to the object-side surface S7 of the fourth lens E4 on the optical axis is 8.3909mm. Figure 20 As shown, when the object distance M of the optical imaging system 4002 is 400mm at the center, the distance P of the image-side surface S6 of the third lens E3 relative to the object-side surface S7 of the fourth lens E4 on the optical axis is 7.9688mm. Figure 21 As shown, when the object distance M of the optical imaging system 4003 is at infinity at the far end, the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 7.7982 mm.

[0082] Table 8 shows the higher-order coefficients that can be used for each aspherical mirror in Example 4, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0083] Table 8

[0084] Example 5 The following is for reference Figures 25-30 An optical imaging system according to Embodiment 5 of this application is described. Figure 25 , Figure 26 , Figure 27 Schematic diagrams of the optical imaging system according to Embodiment 5 of this application are shown at object distances of 100mm, 400mm, and infinity. Figure 28 , Figure 29 , Figure 30 The on-axis chromatic aberration, astigmatism, and distortion curves of the optical imaging system according to Embodiment 5 of this application are shown respectively at object distances of 100 mm, 400 mm, and infinity.

[0085] like Figures 25-27 As shown, the optical imaging system according to an exemplary embodiment of this application includes, in sequence along the optical axis from the object side to the image side: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, STO, a fifth lens E5, a sixth lens E6, a seventh lens E7, an eighth lens E8, a filter IR, and an imaging surface S18.

[0086] The first lens E1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0087] The second lens E2 has negative optical power, its object side S3 is convex, and its image side S4 is concave.

[0088] The third lens E3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0089] The fourth lens E4 has positive optical power, its object side S7 is convex, and its image side S8 is convex.

[0090] The fifth lens E5 has positive optical power, its object side S9 is concave, and its image side S10 is convex.

[0091] The sixth lens E6 has negative optical power, its object side S10 is concave, and its image side S11 is convex.

[0092] The seventh lens E7 has positive optical power, its object side S12 is convex, and its image side S13 is convex.

[0093] The eighth lens E8 has positive optical power, its image-side surface S14 is concave, and its image-side surface S15 is convex.

[0094] The filter IR has an object-side surface S16 and an image-side surface S17. Light from the object passes sequentially through each surface S1 to S17 and is finally imaged onto the imaging surface S18.

[0095] Table 9 shows the basic parameters of optical imaging systems 5001, 5002 and 5003 of Embodiment 5, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0096] Table 9

[0097] In Example 5, as Figures 25-27 As shown, the fourth lens E4 can be displaced along the optical axis. The sum of the distance P on the optical axis between the image-side surface S6 of the third lens E3 and the object-side surface S7 of the fourth lens E4, and the distance T on the optical axis between the image-side surface S8 of the fourth lens E4 and the aperture stop STO, P+T, is 15.6475 mm. The sum of the distance Q on the optical axis between the image-side surface S15 of the eighth lens E8 and the object-side surface S16 of the filter IR, and the distance S on the optical axis between the image-side surface S17 of the filter IR and the imaging surface S18, Q+S, is 8.9303 mm. Figure 25 As shown, when the object distance M of the optical imaging system 5001 is 100mm at the near end, the distance P of the image-side surface S6 of the third lens E3 relative to the object-side surface S7 of the fourth lens E4 on the optical axis is 8.6361mm. Figure 26 As shown, when the object distance M of the optical imaging system 5002 is 400mm at the center, the distance P of the image-side surface S6 of the third lens E3 relative to the object-side surface S7 of the fourth lens E4 on the optical axis is 8.2271mm. Figure 27 As shown, when the object distance M of the optical imaging system 5003 is at infinity at the far end, the distance P of the image side surface S6 of the third lens E3 relative to the object side surface S7 of the fourth lens E4 on the optical axis is 8.0631 mm.

[0098] Table 10 shows the high order term coefficients of each aspherical mirror surface used in Example 5, wherein each aspherical surface type can be defined by the formula (1) given in Example 1 above.

[0099] Table 10

[0100] In Examples 1-5, the basic data are as follows: Table 11

[0101] In Examples 1-5, each conditional expression satisfies the conditions of the following table: Table 12

[0102] A camera module at least includes an optical lens, and the optical lens is installed with the industrial zoom optical imaging system described above. The industrial zoom optical imaging system configured by the application can meet the demand of a large range of object distance shooting while ensuring the imaging quality, thereby reducing the physical space required when moving the components of the automatic equipment, and further improving the production efficiency.

[0103] The above is one or more embodiments provided in combination with specific content, and does not mean that the specific implementation of the application is limited to these descriptions. Any approximation, similarity, or replacement of the method, structure, etc. of the application, or any technical deduction or replacement under the premise of the concept of the application, should be considered as the protection scope of the application.

Claims

1. An industrial class zoom optical imaging system characterized by: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are arranged along the optical axis from the object side to the image side in sequence; The first lens has positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; The second lens has negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; The third lens has negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; The fourth lens has positive refractive power, the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; The fifth lens has positive refractive power, the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface; The sixth lens has negative refractive power, the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; The seventh lens has positive refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; The eighth lens has positive refractive power, and the image side surface of the eighth lens is a convex surface; The fourth lens is movable along the optical axis; The optical system satisfies the following conditions: 6.8mm≤f<9.2mm, TTL<56.6mm; f is the effective focal length of the optical imaging system, and TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis.

2. The industrial class zoom optical imaging system of claim 1, wherein: The optical imaging system satisfies the following relationship: 15.9<TTL*Fnoi / fi<19.9; and / or 15.4<TTL*Fnoj / fj<19.3; and / or 15.2<TTL*Fnok / fk<19.1; and / or 9.0<HFOVi / EPDi<14.2; and / or 8.7<HFOVj / EPDj<13.7; and / or 8.6<HFOVk / EPDk<13.5; Wherein, TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis, Fno is the effective F number of the optical imaging system, f is the effective focal length of the optical imaging system, HFOV is half of the maximum field of view angle of the optical imaging system, EPD is the entrance pupil diameter of the optical imaging system, fi is the effective focal length of the optical imaging system at the near object distance of 100mm, fj is the effective focal length of the optical imaging system at the intermediate object distance of 400mm, fk is the effective focal length of the optical imaging system at the infinite object distance, Fnoi is the effective F number of the optical imaging system at the near object distance of 100mm, Fnoj is the effective F number of the optical imaging system at the intermediate object distance of 400mm, Fnok is the effective F number of the optical imaging system at the infinite object distance, HFOVi is half of the maximum field of view angle of the optical imaging system at the near object distance of 100mm, HFOVj is half of the maximum field of view angle of the optical imaging system at the intermediate object distance of 400mm, HFOVk is half of the maximum field of view angle of the optical imaging system at the infinite object distance, EPDi is the entrance pupil diameter of the optical imaging system at the near object distance of 100mm, EPDj is the entrance pupil diameter of the optical imaging system at the intermediate object distance of 400mm, EPDk is the entrance pupil diameter of the optical imaging system at the infinite object distance.

3. The industrial class zoom optical imaging system of claim 1, wherein: The optical imaging system satisfies the following relationship: 5.8 < f1*f2 / (f5*f6) < 7.3; and / or 17.8 < R1-R4 / (R2-R3) < 19.4; and / or 6.5 < (R5+R6+R7) / |f3| < 9.4; and / or 2.5 < |(R9+R10) / (2*f4)| < 4.1; wherein f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, R1 is the curvature radius of the object side surface of the first lens, R2 is the curvature radius of the image side surface of the first lens, R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, R7 is the curvature radius of the object side surface of the fourth lens, R9 is the curvature radius of the object side surface of the fifth lens, and R10 is the curvature radius of the image side surface of the fifth lens.

4. The industrial zoom optical imaging system according to any one of claims 1-3, characterized in that: The optical imaging system satisfies the following relationship: 9.4 < (f12-f34i) / f23 < 11.1; and / or 9.6 < (f12-f34j) / f23 < 11.5; and / or 9.7 < (f12-f34k) / f23 < 11.7; wherein f12 is the combined focal length of the first lens and the second lens, f23 is the combined focal length of the second lens and the third lens, f34 is the combined focal length of the third lens and the fourth lens, f34i is the combined focal length of the third lens and the fourth lens of the optical imaging system at a near object distance of 100mm, f34j is the combined focal length of the third lens and the fourth lens of the optical imaging system at an intermediate object distance of 400mm, and f34k is the combined focal length of the third lens and the fourth lens of the optical imaging system at an infinite object distance.

5. The industrial zoom optical imaging system of any of claims 1-3, wherein: The optical imaging system satisfies the following relationship: 4.2 < ΣCT / CT4 < 6.2; wherein ΣCT is the sum of the central thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens on the optical axis, and CT4 is the central thickness of the fourth lens on the optical axis.

6. The industrial zoom optical imaging system of any of claims 1-3, wherein: The industrial zoom optical imaging system has a range of object distances from 100mm to infinity.

7. The industrial zoom optical imaging system according to any one of claims 1-3, wherein: The optical system satisfies the following condition: 63.9° < FOV < 79.6°; wherein FOV is the full field of view of the optical imaging system.

8. The industrial zoom optical imaging system of any of claims 1-3, wherein: The diaphragm is disposed between the fourth lens and the fifth lens.

9. The industrial zoom optical imaging system of any of claims 1-3, wherein: The first lens, the second lens, the fourth lens, and the eighth lens are spherical glass lenses, and the third lens, the fifth lens, the sixth lens, and the seventh lens are aspherical plastic lenses.

10. An image capturing module comprising at least an optical lens, characterized in that: The optical lens has the industrial zoom optical imaging system according to any one of claims 1-9 installed therein.

Images