Optical System, Camera Module, and Electronic Device

Abstract

An optical system, a camera module, and an electronic device. The optical system sequentially includes, from the object side to the image side along the optical axis direction: a right-angle prism, the right-angle prism includes an incident light surface, a reflecting surface, and an emergent light surface. Light enters the incident light surface perpendicularly and is totally reflected by the reflecting surface and then exits from the emergent light surface; the first lens to the eighth lens, where at least one of them is an aspherical plastic lens; the first lens and the second lens form a first lens group with negative refractive power, the third lens to the fifth lens form a second lens group with positive refractive power, and the sixth lens to the eighth lens form a third lens group with positive refractive power. By setting the right-angle prism to deflect light, a folded periscope structure is formed, and by reasonably setting the refractive power of the first lens to the eighth lens, on the one hand, the lateral distance is shortened and the occupied space of the optical system is reduced; on the other hand, sufficient length is provided for the optical system to achieve a large range of zoom.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical imaging, and in particular relates to an optical system, a camera module and an electronic device. Background Art

[0002] In recent years, many mobile phones with triple or quadruple cameras have emerged on the market. Such mobile phones achieve effects such as ultra-clear shooting, wide-angle shooting, and telephoto shooting by switching different lenses. On the one hand, this lens configuration meets the user's photography needs in different scenarios. On the other hand, there are also some drawbacks. For example, to obtain a high zoom ratio characteristic, the total length of the optical system will also increase accordingly, but it is restricted by the limited space of the mobile phone. Therefore, how to further shorten the total length of the optical system and achieve a large range of zoom while realizing miniaturization has become one of the problems to be solved in the industry currently. Summary of the Invention

[0003] The purpose of the present invention is to provide an optical system, a camera module and an electronic device, which can meet the requirements of large range of zoom and miniaturization at the same time.

[0004] To achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides an optical system, which sequentially includes, along the optical axis from the object side to the image side: a right-angle prism, the right-angle prism includes an incident surface, a reflecting surface and an exit surface, the incident surface and the exit surface are perpendicularly connected, the reflecting surface connects the incident surface and the exit surface, light enters the incident surface perpendicularly and is totally reflected by the reflecting surface and then exits from the exit surface; a first lens group, opposite to the exit surface and having a negative refractive power, including a first lens and a second lens sequentially arranged along the optical axis; a second lens group, having a positive refractive power, including a third lens, a fourth lens and a fifth lens sequentially arranged along the optical axis; a third lens group, having a positive refractive power, including a sixth lens, a seventh lens and an eighth lens sequentially arranged along the optical axis; at least one aspherical plastic lens is included in the first lens to the eighth lens.

[0006] By setting the right-angle prism to deflect light, a folded periscope structure is formed, and by reasonably setting the refractive powers of the first lens to the eighth lens, on the one hand, the lateral distance is shortened and the occupied space of the optical system is reduced; on the other hand, sufficient length is provided for the optical system to achieve a large range of zoom.

[0007] In one embodiment, the optical system is a zoom optical system, and the zoom optical system is provided with a telephoto end and a wide-angle end. By making the optical system be in the two states of the telephoto end and the wide-angle end respectively, relevant parameters of the optical system can be designed and adjusted to achieve the purpose of improving the imaging quality of the optical system.

[0008] In one embodiment, the optical system satisfies the conditional formula: Fc / Fd≥2.2; where Fc is the effective focal length of the optical system at the telephoto end, and Fd is the effective focal length of the optical system at the wide-angle end. By satisfying the above relational formula, by reasonably configuring the ratio of the effective focal length at the telephoto end to the effective focal length at the wide-angle end, the optical system can obtain a higher zoom ratio, so as to achieve a large shooting magnification range, so as to achieve the continuous zoom characteristic of the zoom lens group, and the zoom lens group can obtain good imaging quality. When Fc / Fd < 2.2, the continuous zoom range is not sufficient to meet the higher requirements of users for the shooting experience.

[0009] In one embodiment, the optical system satisfies the conditional formula: FOVc / ImgH < 3.9; where FOVc is the full field of view angle of the optical system at the telephoto end, and ImgH is half of the diagonal length of the effective photosensitive area on the imaging surface, that is, the semi-image height. By satisfying the above relational formula, by configuring the ratio of the full field of view angle at the telephoto end to the semi-image height within a reasonable range, it is beneficial to realize the telephoto characteristic of the telephoto end of the optical system, and at the same time, a higher pixel chip can be matched to achieve high-definition shooting.

[0010] In one embodiment, the optical system satisfies the conditional formula: 5.5 < D2c / D2d < 14; where D2c is the distance on the optical axis between the image side of the fifth lens and the object side of the sixth lens when the optical system is at the telephoto end; D2d is the distance on the optical axis between the image side of the fifth lens and the image side of the sixth lens when the optical system is at the wide-angle end. By satisfying the above relational formula, by controlling the ratio of the distance on the optical axis between the image side of the fifth lens and the object side and the image side of the sixth lens when the optical system is at the telephoto end and the wide-angle end, it is beneficial for the optical system to obtain a larger zoom range and achieve a larger magnification shooting effect. In addition, reasonable control of the distance on the optical axis between the image side of the fifth lens and the image side of the sixth lens can also reduce the processing and assembly difficulty of the optical system and further improve the processing performance. When D2c / D2d ≤ 5.5, it is not conducive to broadening the zoom range of the optical system; when D2c / D2d ≥ 14, the distance between the second lens group and the third lens group in the wide-angle state is too small, which will increase the assembly difficulty and is also prone to unsmoothness or lens collision during continuous zoom.

[0011] In one embodiment, the optical system satisfies the conditional formula: 2.5 < et12 / ct12 < 7.5; where et12 is the horizontal distance from the image side of the second lens to the object side of the third lens at the effective diameter, and ct12 is the distance from the image side of the second lens to the object side of the third lens on the optical axis. By satisfying the above relational formula, by keeping the ratio of the intermediate and edge spacings of the first lens group and the second lens group within a reasonable range, it is beneficial for the marginal rays to transition from the first lens group to the second lens group at a relatively small and reasonable angle. At the same time, it is beneficial for the second lens group to correct the aberration of the first lens group. Additionally, it is also beneficial for forming manufacturing and processing assembly. When et12 / ct12 ≤ 2.5, the spacing at the effective diameter between the first lens group and the second lens group is too large, which will cause the deflection angle of the light rays entering the second lens group to be too large; when et12 / ct12 ≥ 7.5, the distance at the effective diameter between the first lens group and the second lens group is too small, which is not conducive to processing assembly and increases the assembly difficulty.

[0012] In one embodiment, the optical system satisfies the conditional formula: 4 < fg3 / g3 < 7.5; where fg3 is the effective focal length of the third lens group, and g3 is the distance from the object side of the sixth lens to the image side of the eighth lens on the optical axis. By satisfying the above relational formula, the third lens group undertakes part of the positive refractive power, and controlling the proportion of the positive refractive power contributed by the third lens group to the optical system is beneficial for correcting the aberration generated by the first lens group with negative refractive power, thereby improving the imaging quality of the optical system; additionally, controlling the total length of the third lens group is beneficial for shortening the total length of the optical system and realizing the miniaturization of the optical system. When fg3 / g3 ≥ 7.5, the third lens group does not provide sufficient positive refractive power, which is not conducive to correcting the aberration generated by the front lens group and affects the imaging quality; when fg3 / g3 ≤ 4, the total length of the third lens group is too long, which is not conducive to shortening the total length of the optical system.

[0013] In one embodiment, the optical system satisfies the conditional formula: 1 < Fc / (f3 + |fjh2|) < 1.3; where Fc is the effective focal length of the optical system at the telephoto end, f3 is the effective focal length of the third lens; fjh2 is the effective focal length of the fourth lens and the fifth lens, and the fourth lens and the fifth lens are glued together to form a cemented lens. When the above relational formula is satisfied, reasonably configuring the ratio of the effective focal length at the telephoto end to the sum of the effective focal lengths of the third lens and the cemented lens is beneficial for realizing the telephoto characteristic, and at the same time is also helpful for expanding the zoom ratio of the optical system; additionally, the second lens group undertakes the positive refractive power required by the optical system, which can effectively correct the spherical aberration generated by the front lens group and is beneficial for improving the resolution of the optical system.

[0014] In one embodiment, the optical system satisfies the conditional formula: -1.2 > |R71| / R82 > -5.2; where R71 is the radius of curvature value of the object side surface of the seventh lens on the optical axis, and R82 is the radius of curvature value of the image side surface of the eighth lens on the optical axis. By satisfying the above relational expression and controlling the ratio of the radius of curvature value of the object side surface of the seventh lens on the optical axis to the radius of curvature value of the image side surface of the eighth lens on the optical axis within a reasonable range, effective constraints on the shapes of the seventh lens and the eighth lens can be achieved, enabling the seventh lens and the eighth lens to cooperate with each other to jointly contribute to aberration, thereby improving the imaging quality of the optical system. When |R71| / R82 ≥ -1.2 or |R71| / R82 ≤ -5.2, the aberration provided by the shape combination of the seventh lens and the eighth lens cannot bring the overall aberration of the optical system to a reasonable balance state.

[0015] In one embodiment, the optical system satisfies the conditional formula: 5 < f8 / ct8 < 50; where f8 is the effective focal length of the eighth lens, and ct8 is the thickness of the eighth lens on the optical axis, i.e., the central thickness. By satisfying the above relational expression and reasonably configuring the ratio of the effective focal length of the eighth lens to the central thickness of the eighth lens, on the one hand, the aberration allocated to the eighth lens by the entire optical system can be controlled, enabling the aberration of the optical system to be in a reasonable level state and thus obtaining good imaging quality. On the other hand, it can help further shorten the overall length of the optical system, constrain the shape of the eighth lens, and enable the optical system to have good processing performance.

[0016] In a second aspect, the present invention further provides an imaging module, which includes a lens barrel, an electronic photosensitive element, and the optical system as described in the above embodiments. The first lens to the eighth lens of the optical system are all installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light of the object incident on the electronic photosensitive element through the right-angle prism to the eighth lens into an electrical signal of an image. By installing the right-angle prism to the eighth lens of the optical system in the imaging module and reasonably configuring the surface types and refractive powers of the lenses from the first lens to the eighth lens, the imaging module can simultaneously meet the requirements of large-range zoom and miniaturization.

[0017] In a third aspect, the present invention further provides an electronic device, which includes a housing and the imaging module described in the second aspect, and the imaging module is arranged in the housing. By incorporating the imaging module provided by the present invention into the electronic device, the electronic device can simultaneously meet the requirements of large-range zoom and miniaturization.

[0018] In summary, the present invention reduces the lateral length and overall height of the camera module by providing a right-angle prism capable of changing the optical path direction and horizontally placing the camera module in the electronic device housing during installation, meeting the requirements of gradually increasing pixel count, gradually expanding zoom range, and miniaturization of the optical imaging lens, thereby achieving the miniaturization requirement of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0020] Figure 1a is a schematic structural diagram of the optical system of the first embodiment at the short focal end;

[0021] Figure 1b is the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the short focal end;

[0022] Figure 1c A schematic structural diagram of the optical system of the first embodiment at the medium focal end;

[0023] Figure 1d is the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the medium focal end;

[0024] Figure 1e is a schematic structural diagram of the optical system of the first embodiment at the long focal end;

[0025] Figure 1f is the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the long focal end;

[0026] Figure 2a is a schematic structural diagram of the optical system of the second embodiment at the short focal end;

[0027] Figure 2b is the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment at the short focal end;

[0028] Figure 2c A schematic structural diagram of the optical system of the second embodiment at the medium focal end;

[0029] Figure 2d is the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment at the medium focal end;

[0030] Figure 2eIt is a schematic structural diagram of the optical system of the second embodiment at the telephoto end;

[0031] Figure 2f It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment at the telephoto end;

[0032] Figure 3a It is a schematic structural diagram of the optical system of the third embodiment at the wide-angle end;

[0033] Figure 3b It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment at the wide-angle end;

[0034] Figure 3c Schematic structural diagram of the optical system of the third embodiment at the mid-focal length end;

[0035] Figure 3d It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment at the mid-focal length end;

[0036] Figure 3e It is a schematic structural diagram of the optical system of the third embodiment at the telephoto end;

[0037] Figure 3f It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment at the telephoto end;

[0038] Figure 4a It is a schematic structural diagram of the optical system of the fourth embodiment at the wide-angle end;

[0039] Figure 4b It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment at the wide-angle end;

[0040] Figure 4c Schematic structural diagram of the optical system of the fourth embodiment at the mid-focal length end;

[0041] Figure 4d It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment at the mid-focal length end;

[0042] Figure 4e It is a schematic structural diagram of the optical system of the fourth embodiment at the telephoto end;

[0043] Figure 4f It is the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment at the telephoto end;

[0044] Figure 5a It is a schematic structural diagram of the optical system of the fifth embodiment at the wide-angle end;

[0045] Figure 5b The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the short focal end;

[0046] Figure 5c The schematic structural diagram of the optical system of the fifth embodiment at the medium focal end;

[0047] Figure 5d The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the medium focal end;

[0048] Figure 5e The schematic structural diagram of the optical system of the fifth embodiment at the long focal end;

[0049] Figure 5f The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the long focal end;

[0050] Figure 6a The schematic structural diagram of the optical system of the sixth embodiment at the short focal end;

[0051] Figure 6b The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the short focal end;

[0052] Figure 6c The schematic structural diagram of the optical system of the sixth embodiment at the medium focal end;

[0053] Figure 6d The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the medium focal end;

[0054] Figure 6e The schematic structural diagram of the optical system of the sixth embodiment at the long focal end;

[0055] Figure 6f The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the long focal end. Detailed implementation manners

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] The present invention provides an optical system, which sequentially includes, along the optical axis from the object side to the image side: a right-angle prism, the right-angle prism includes an incident light surface, a reflection surface, and an emergent light surface, the incident light surface and the emergent light surface are perpendicularly connected, the reflection surface connects the incident light surface and the emergent light surface, light enters the incident light surface perpendicularly and is totally reflected by the reflection surface and then exits from the emergent light surface; a first lens group, opposite to the emergent light surface and having a negative refractive power, including a first lens and a second lens sequentially arranged along the optical axis; a second lens group, having a positive refractive power, including a third lens, a fourth lens, and a fifth lens sequentially arranged along the optical axis; a third lens group, having a positive refractive power, including a sixth lens, a seventh lens, and an eighth lens sequentially arranged along the optical axis; the first lens to the eighth lens include at least one aspherical plastic lens.

[0058] By providing a right-angle prism to deflect light rays, a folded periscope structure is formed, and by reasonably setting the refractive powers of the first lens to the eighth lens, on the one hand, the lateral distance is shortened and the occupied space of the optical system is reduced; on the other hand, sufficient length is provided for the optical system to achieve a large range of zoom.

[0059] In one embodiment, the optical system is a zoom optical system, and the zoom optical system is provided with a telephoto end and a wide-angle end. Among them, the telephoto end is the state when the focal length of the optical system is the largest, and the wide-angle end is the state when the focal length of the optical system is the smallest. By making the optical system be in the two states of the telephoto end and the wide-angle end, relevant parameters of the optical system can be designed and adjusted to achieve the purpose of improving the imaging quality of the optical system.

[0060] In one embodiment, the optical system satisfies the conditional formula: Fc / Fd≥2.2; where Fc is the effective focal length of the optical system at the telephoto end, and Fd is the effective focal length of the optical system at the wide-angle end. By satisfying the above relational formula, by reasonably configuring the ratio of the effective focal length at the telephoto end to the effective focal length at the wide-angle end, the optical system can obtain a high zoom ratio, so as to achieve a large range of shooting magnifications, to realize the continuous zoom characteristic of the zoom lens group, and to make the zoom lens group obtain good imaging quality. When Fc / Fd<2.2, the continuous zoom range is not sufficient to meet the higher requirements of users for the shooting experience.

[0061] In one embodiment, the optical system satisfies the conditional formula: FOVc / ImgH<3.9; where FOVc is the full field of view angle of the optical system at the telephoto end, and ImgH is half of the diagonal length of the effective photosensitive area on the imaging surface, that is, the half image height. By satisfying the above relational formula, by configuring the ratio of the full field of view angle at the telephoto end to the half image height within a reasonable range, it is beneficial to realize the telephoto characteristic of the optical system at the telephoto end, and at the same time, a higher pixel chip can be matched to achieve high-definition shooting.

[0062] In one embodiment, the optical system satisfies the conditional formula: 5.5 < D2c / D2d < 14; where D2c is the distance on the optical axis between the image side of the fifth lens and the object side of the sixth lens when the optical system is at the telephoto end; D2d is the distance on the optical axis between the image side of the fifth lens and the image side of the sixth lens when the optical system is at the wide-angle end. By satisfying the above relational expression and controlling the ratio of the distances on the optical axis between the image side of the fifth lens and the object side and the image side of the sixth lens when the optical system is at the telephoto end and the wide-angle end, it is beneficial for the optical system to obtain a larger zoom range and achieve a larger magnification shooting effect. In addition, reasonable control of the distance on the optical axis between the image side of the fifth lens and the image side of the sixth lens can also reduce the processing and assembly difficulty of the optical system and further improve the processing performance. When D2c / D2d ≤ 5.5, it is not conducive to broadening the zoom range of the optical system; when D2c / D2d ≥ 14, the distance between the second lens group and the third lens group in the wide-angle state is too small, which will increase the assembly difficulty and is also likely to cause unsmoothness or lens collision during continuous zooming.

[0063] In one embodiment, the optical system satisfies the conditional formula: 2.5 < et12 / ct12 < 7.5; where et12 is the horizontal distance between the image side of the second lens and the object side of the third lens at the effective diameter, and ct12 is the distance on the optical axis between the image side of the second lens and the object side of the third lens. By satisfying the above relational expression and keeping the ratio of the middle and edge spacings between the first lens group and the second lens group within a reasonable range, it is beneficial for the marginal rays to transition from the first lens group to the second lens group at a relatively small and reasonable angle, and at the same time, it is beneficial for the second lens group to correct the aberration of the first lens group. In addition, it is also beneficial for forming manufacturing and processing and assembly. When et12 / ct12 ≤ 2.5, the spacing at the effective diameter between the first lens group and the second lens group is too large, which will cause the deflection angle of the light rays entering the second lens group to be too large; when et12 / ct12 ≥ 7.5, the distance at the effective diameter between the first lens group and the second lens group is too small, which is not conducive to processing and assembly and increases the assembly difficulty. Among them, the distance at the effective diameter between the first lens group and the second lens group is the distance on the optical axis direction from the effective diameter of the image side of the second lens to the effective diameter of the object side of the third lens.

[0064] In one embodiment, the optical system satisfies the conditional formula: 4 < fg3 / g3 < 7.5; where fg3 is the effective focal length of the third lens group, and g3 is the distance on the optical axis from the object side surface of the sixth lens to the image side surface of the eighth lens. By satisfying the above relational expression, the third lens group undertakes part of the positive refractive power, and controlling the proportion of the positive refractive power contributed by the third lens group to the optical system is beneficial to correcting the aberration generated by the first lens group with negative refractive power, thereby improving the imaging quality of the optical system; in addition, controlling the total length of the third lens group is beneficial to shortening the total length of the optical system and realizing the miniaturization of the optical system. When fg3 / g3 ≥ 7.5, the third lens group does not provide sufficient positive refractive power, which is not conducive to correcting the aberration generated by the front lens group and affects the imaging quality; when fg3 / g3 ≤ 4, the total length of the third lens group is too long, which is not conducive to shortening the total length of the optical system.

[0065] In one embodiment, the optical system satisfies the conditional formula: 1 < Fc / (f3 + |fjh2|) < 1.3; where Fc is the effective focal length of the optical system at the telephoto end, f3 is the effective focal length of the third lens; fjh2 is the effective focal length of the fourth lens and the fifth lens, and the fourth lens and the fifth lens are glued together to form a cemented lens. When the above relational expression is satisfied, reasonably configuring the ratio of the effective focal length at the telephoto end to the sum of the effective focal lengths of the third lens and the cemented lens is beneficial to achieving the telephoto characteristic and also helps to expand the zoom ratio of the optical system; in addition, the second lens group undertakes the positive refractive power required by the optical system, and can effectively correct the spherical aberration generated by the front lens group, which is beneficial to improving the resolving power of the optical system.

[0066] In one embodiment, the optical system satisfies the conditional formula: -1.2 > |R71| / R82 > -5.2; where R71 is the curvature radius value of the object side surface of the seventh lens on the optical axis, and R82 is the curvature radius value of the image side surface of the eighth lens on the optical axis. By satisfying the above relational expression, controlling the ratio of the curvature radius value of the object side surface of the seventh lens on the optical axis to the curvature radius value of the image side surface of the eighth lens on the optical axis within a reasonable range can effectively constrain the shapes of the seventh lens and the eighth lens, enabling the seventh lens and the eighth lens to cooperate with each other to jointly contribute to the aberration, thereby improving the imaging quality of the optical system. When |R71| / R82 ≥ -1.2 or |R71| / R82 ≤ -5.2, the aberration provided by the shape combination of the seventh lens and the eighth lens cannot make the overall aberration of the optical system reach a reasonable balance state.

[0067] In one embodiment, the optical system satisfies the conditional formula: 5 < f8 / ct8 < 50; where f8 is the effective focal length of the eighth lens, and ct8 is the thickness of the eighth lens on the optical axis, i.e., the center thickness. By satisfying the above relational expression, by reasonably configuring the ratio of the effective focal length of the eighth lens to the center thickness of the eighth lens, on the one hand, the aberration allocated to the eighth lens by the entire optical system can be controlled, so that the aberration of the optical system is in a reasonable level state and thus good imaging quality can be obtained. On the other hand, it can help to further shorten the overall length of the optical system, restrict the shape of the eighth lens, and enable the optical system to have good processing performance.

[0068] An embodiment of the present invention provides an imaging module, which includes a lens barrel, an electronic photosensitive element, and the optical system provided by the embodiment of the present invention. The first lens to the eighth lens are all installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system, and is used to convert the light of the object incident on the electronic photosensitive element through the right-angle prism to the eighth lens into an electrical signal of an image. The electronic photosensitive element can be a Complementary Metal Oxide Semiconductor (CMOS) or a Charge-coupled Device (CCD). The imaging module can be an independent lens of a digital camera or an imaging module integrated on an electronic device such as a smart phone. By installing the right-angle prism to the eighth lens of the optical system in the imaging module and reasonably configuring the surface shape and refractive power of each lens from the first lens to the eighth lens, the imaging module can simultaneously meet the requirements of large-range zoom and miniaturization.

[0069] An embodiment of the present invention provides an electronic device, which includes a housing and the imaging module provided by the embodiment of the present invention. The imaging module and the electronic photosensitive element are arranged in the housing. The electronic device can be a smart phone, a Personal Digital Assistant (PDA), a tablet computer, a smart watch, a drone, an e-book reader, a driving recorder, a wearable device, etc. By adding the imaging module provided by the present invention to the electronic device, the electronic device can simultaneously meet the requirements of large-range zoom and miniaturization.

[0070] The first embodiment

[0071] Please refer to Figures 1a to 1f , the optical system of this embodiment includes, in order from the object side to the image side along the optical axis direction:

[0072] A right-angle prism E, the prism E has an incident surface A1, a reflecting surface A2, and an exit surface A3. It can be understood that when the light from the object to be photographed enters the prism E perpendicularly through the incident surface A1, it can be totally reflected by the reflecting surface A2 and turned to the exit surface A3 to exit along the direction of the optical axis and enter the lens part;

[0073] The first lens L1 has a negative refractive power. The object side S1 and the image side S2 of the first lens L1 are both concave near the optical axis; the object side S1 and the image side S2 of the first lens L1 are both convex near the circumference.

[0074] The second lens L2 has a positive refractive power and is cemented to the first lens L1. Since the second lens L2 is cemented to the first lens L1, the object side of the second lens L2 coincides with the image side S2 of the first lens L1. In this embodiment and other embodiments, the object side of the second lens L2 is still denoted as S2. The object side S2 and the image side S3 of the second lens L2 are both convex near the optical axis; the object side S2 of the second lens L2 is concave near the circumference, and the image side S3 is convex near the circumference.

[0075] The third lens L3 has a positive refractive power. The object side S4 and the image side S5 of the third lens L3 are both convex near the optical axis; the object side S4 of the third lens L3 is convex near the circumference, and the image side S5 is concave near the circumference.

[0076] The fourth lens L4 has a positive refractive power. The object side S6 and the image side S7 of the fourth lens are both convex near the optical axis; the object side S6 and the image side S7 of the fourth lens L4 are both concave near the circumference.

[0077] The fifth lens L5 has a negative refractive power. Since the fifth lens L5 is cemented to the fourth lens L4, the object side of the fifth lens L5 coincides with the image side S7 of the fourth lens L4. In this embodiment and other embodiments, the object side of the fifth lens L5 is still denoted as S7. The object side S7 and the image side S8 of the fifth lens L5 are both concave near the optical axis; the object side S7 and the image side S8 of the fifth lens L5 are both convex near the circumference.

[0078] The sixth lens L6 has a negative refractive power. The object side S9 and the image side S10 of the sixth lens are both concave near the optical axis; the object side S9 and the image side S10 of the sixth lens L6 are both concave near the circumference.

[0079] The seventh lens L7 has a negative refractive power. The object side S11 of the seventh lens L7 is convex near the optical axis, and the image side S12 is concave near the optical axis; the object side S11 of the seventh lens L7 is concave near the circumference, and the image side S12 is convex near the circumference.

[0080] The eighth lens L8 has a positive refractive power. The object side S13 and the image side S14 of the eighth lens L8 are both convex near the optical axis; the object side S13 of the eighth lens L8 is convex near the circumference, and the image side S14 is concave near the circumference.

[0081] The materials of the above-mentioned first lens L1 to eighth lens L8 are plastic or glass. At least one of the first lens L1 to eighth lens L8 is an aspherical plastic lens.

[0082] In addition, the optical system further includes a diaphragm STO, an infrared cut-off filter IR, and an imaging surface IMG. In this embodiment, the diaphragm STO is disposed between the second lens L2 and the third lens L3 to control the amount of incident light. In other embodiments, the diaphragm STO can also be disposed between other adjacent two lenses, or on other lenses. The infrared cut-off filter IR is disposed between the image side S14 of the eighth lens L8 and the imaging surface IMG, and it includes an object side S15 and an image side S16. The infrared cut-off filter IR is used to filter out infrared light so that the light incident on the imaging surface IMG is visible light, and the wavelength of the visible light is 380nm - 780nm. The material of the infrared cut-off filter is glass (GLASS), and a film can be coated on the glass. The effective pixel region of the electronic photosensitive element is located on the imaging surface IMG.

[0083] Tables 1a(1) - 1a(2) show the table of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative of the thickness value only represent the direction.

[0084] Table 1a(1)

[0085]

[0086]

[0087] Table 1a(2)

[0088] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 9.7871 1.3209 5.5264 13.00 2.80 26.47 33.20 Medium focus position 5.5359 5.4542 4.3427 17.82 3.43 19.21 31.90 Telephoto position 0.1000 12.9164 3.0176 29.75 4.83 11.55 32.60

[0089] Among them, D1, D2, and D3 are all the on-axis distances from the current surface to the next surface, EFL is the effective focal length of the optical system, FNO is the aperture number of the optical system, FOV is the maximum field of view angle of the optical system, and TTL is the distance on the optical axis from the object side S1 of the first lens L1 to the imaging surface IMG.

[0090] In this embodiment, both the object side and the image side of the first lens L1 to eighth lens L8 are aspherical surfaces, and the surface profile x of the aspherical surface can be defined by, but not limited to, the following aspherical formula:

[0091]

[0092] Wherein, x is the sagitta, which is the distance from the vertex of the aspheric surface to the position at height h along the optical axis direction of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the Y radius R in Table 1a(1) above); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 1b gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 for the aspheric mirrors S1 to S14 that can be used in the first embodiment.

[0093] Table 1b

[0094]

[0095] Figure 1a Fig. shows a schematic structural diagram of the optical system of the first embodiment at the short focal end. Figure 1b Fig. shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the short focal end. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; the astigmatism curve represents the meridional image plane curvature and sagittal image plane curvature; the distortion curve represents the distortion magnitude values corresponding to different field angles. According to Figure 1b It can be seen that the optical system given in the first embodiment can achieve good imaging quality.

[0096] Figure 1c Fig. shows a schematic structural diagram of the optical system of the first embodiment at the medium focal end. Figure 1d Fig. shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the medium focal end. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; the astigmatism curve represents the meridional image plane curvature and sagittal image plane curvature; the distortion curve represents the distortion magnitude values corresponding to different field angles. According to Figure 1d It can be seen that the optical system given in the first embodiment can achieve good imaging quality.

[0097] Figure 1e Fig. shows a schematic structural diagram of the optical system of the first embodiment at the long focal end. Figure 1f Fig. shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the first embodiment at the long focal end. Among them, the longitudinal spherical aberration curve represents the deviation of the convergence points of light rays of different wavelengths after passing through each lens of the optical system; the astigmatism curve represents the meridional image plane curvature and sagittal image plane curvature; the distortion curve represents the distortion magnitude values corresponding to different field angles. According to Figure 1f It can be seen that the optical system given in the first embodiment can achieve good imaging quality.

[0098] Second Embodiment

[0099] Please refer toFigures 2a to 2f , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0100] A right-angled prism E, the prism E has an incident surface A1, a reflecting surface A2, and an exit surface A3. It can be understood that when the light from the object to be photographed enters the prism E perpendicularly through the incident surface A1, it can be totally reflected by the reflecting surface A2 and turned to the exit surface A3 to exit along the direction of the optical axis and enter the lens part;

[0101] The first lens L1, the first lens L1 has a negative refractive power. The object side surface S1 and the image side surface S2 of the first lens L1 are both concave surfaces near the optical axis; the object side surface S1 and the image side surface S2 of the first lens L1 are both convex surfaces near the circumference.

[0102] The second lens L2, the second lens L2 has a positive refractive power, and the second lens L2 is glued to the first lens L1. The object side surface S2 and the image side surface S3 of the second lens L2 are both convex surfaces near the optical axis; the object side surface S2 of the second lens L2 is concave near the circumference, and the image side surface S3 is convex near the circumference.

[0103] The third lens L3, the third lens L3 has a positive refractive power. The object side surface S4 and the image side surface S5 of the third lens L3 are both convex surfaces near the optical axis; the object side surface S4 of the third lens L3 is convex near the circumference, and the image side surface S5 is concave near the circumference.

[0104] The fourth lens L4, the fourth lens has a positive refractive power. The object side surface S6 and the image side surface S7 of the fourth lens are both convex surfaces near the optical axis; the object side surface S6 and the image side surface S7 of the fourth lens L4 are both concave surfaces near the circumference.

[0105] The fifth lens L5, the fifth lens L5 has a negative refractive power. The object side surface S7 and the image side surface S8 of the fifth lens L5 are both concave surfaces near the optical axis; the object side surface S7 and the image side surface S8 of the fifth lens L5 are both convex surfaces near the circumference.

[0106] The sixth lens L6, the sixth lens has a negative refractive power. The object side surface S9 and the image side surface S10 of the sixth lens are both concave surfaces near the optical axis; the object side surface S9 and the image side surface S10 of the sixth lens L6 are both concave surfaces near the circumference.

[0107] The seventh lens L7, the seventh lens L7 has a negative refractive power. The object side surface S11 and the image side surface S12 of the seventh lens L7 are both convex surfaces near the optical axis; the object side surface S11 of the seventh lens L7 is convex near the circumference, and the image side surface S12 is concave near the circumference.

[0108] The eighth lens L8, the eighth lens L8 has a positive refractive power. The object side surface S13 of the eighth lens L8 is concave near the optical axis, and the image side surface S14 is convex near the optical axis; the object side surface S13 of the eighth lens L8 is convex near the circumference, and the image side surface S14 is concave near the circumference.

[0109] The other structures of the second embodiment are the same as those of the first embodiment, and can be referred to accordingly.

[0110] Table 2a(1) - Table 2a(2) shows a table of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative values of the thickness only represent directions.

[0111] Table 2a(1)

[0112]

[0113]

[0114] Table 2a(2)

[0115] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 9.6326 1.9173 5.6317 13.51 2.91 25.37 33.20 Medium focus position 5.7509 5.6390 4.4897 17.82 3.45 19.13 31.90 Telephoto position 0.1000 13.3843 2.8640 30.00 4.89 11.42 32.37

[0116] Among them, the meanings of the parameters in Table 2a(2) are the same as those of the parameters in the first embodiment.

[0117] Table 2b gives the high-order term coefficients that can be used for each aspherical mirror surface in the second embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0118] Table 2b

[0119]

[0120]

[0121] Figure 2a Shows a schematic structural diagram of the optical system of the second embodiment at the short focal length end. Figure 2b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment at the short focal length end. According to Figure 2b It can be seen that the optical system given in the second embodiment can achieve good imaging quality.

[0122] Figure 2c Shows a schematic structural diagram of the optical system of the second embodiment at the medium focal length end. Figure 2d Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment at the medium focal length end. According to Figure 2d It can be seen that the optical system given in the second embodiment can achieve good imaging quality.

[0123] Figure 2e Shows a schematic structural diagram of the optical system of the second embodiment at the long focal length end. Figure 2fShows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the second embodiment at the telephoto end. According to Figure 2f it can be known that the optical system given by the second embodiment can achieve good imaging quality.

[0124] Third Embodiment

[0125] Please refer to Figures 3a to 3f , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0126] Right-angle prism E, the prism E has an incident surface A1, a reflecting surface A2, and an exit surface A3. It can be understood that when the light from the object to be photographed enters the prism E vertically through the incident surface A1, it can be totally reflected by the reflecting surface A2 and turned to the exit surface A3 to exit along the direction of the optical axis, and enter the lens part;

[0127] The first lens L1, the first lens L1 has a negative refractive power, and the object side surface S1 and the image side surface S2 of the first lens L1 are both concave surfaces near the optical axis; the object side surface S1 and the image side surface S2 of the first lens L1 are both convex surfaces near the circumference.

[0128] The second lens L2, the second lens L2 has a positive refractive power, and the second lens L2 is glued to the first lens L1. The object side surface S2 and the image side surface S3 of the second lens L2 are both convex surfaces near the optical axis; the object side surface S2 of the second lens L2 is concave near the circumference, and the image side surface S3 is convex near the circumference.

[0129] The third lens L3, the third lens L3 has a positive refractive power, and the object side surface S4 and the image side surface S5 of the third lens L3 are both convex surfaces near the optical axis; the object side surface S4 of the third lens L3 is convex near the circumference, and the image side surface S5 is concave near the circumference.

[0130] The fourth lens L4, the fourth lens has a positive refractive power, and the object side surface S6 and the image side surface S7 of the fourth lens are both convex surfaces near the optical axis; the object side surface S6 and the image side surface S7 of the fourth lens L4 are both concave surfaces near the circumference.

[0131] The fifth lens L5, the fifth lens L5 has a negative refractive power, and the object side surface S7 and the image side surface S8 of the fifth lens L5 are both concave surfaces near the optical axis; the object side surface S7 and the image side surface S8 of the fifth lens L5 are both convex surfaces near the circumference.

[0132] The sixth lens L6, the sixth lens has a negative refractive power, and the object side surface S9 and the image side surface S10 of the sixth lens are both concave surfaces near the optical axis; the object side surface S9 of the sixth lens L6 is convex near the circumference, and the image side surface S10 is concave near the circumference.

[0133] The seventh lens L7 has a negative refractive power. The object side surface S11 of the seventh lens L7 is convex near the optical axis, and the image side surface S12 is concave near the optical axis; the object side surface S11 of the seventh lens L7 is concave near the circumference, and the image side surface S12 is convex near the circumference.

[0134] The eighth lens L8 has a positive refractive power. Both the object side surface S13 and the image side surface S14 of the eighth lens L8 are convex near the optical axis; the object side surface S13 of the eighth lens L8 is convex near the circumference, and the image side surface S14 is concave near the circumference.

[0135] The other structures of the third embodiment are the same as those of the first embodiment, and can be referred to.

[0136] Tables 3a(1) to 3a(2) show the tables of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative values of the thickness only represent the direction.

[0137] Table 3a(1)

[0138]

[0139]

[0140] Table 3a(2)

[0141] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 10.3179 0.9641 5.5421 12.51 2.77 27.54 33.20 Medium focus position 6.1787 4.9911 4.3433 17.00 3.32 20.13 31.89 Telephoto position 0.0938 13.1015 2.9798 30.00 4.84 11.45 32.55

[0142] Among them, the meanings of the parameters in Table 3a(2) are the same as those of the parameters in the first embodiment.

[0143] Table 3b gives the high-order term coefficients that can be used for each aspherical mirror surface in the third embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0144] Table 3b

[0145]

[0146]

[0147] Figure 3a Shows a schematic structural diagram of the optical system of the third embodiment at the short focal length end. Figure 3b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the third embodiment at the short focal length end. According to Figure 3b It can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0148] Figure 3cShows a schematic structural diagram of the optical system of the third embodiment at the mid-focal end. Figure 3d Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the third embodiment at the mid-focal end. According to Figure 3d it can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0149] Figure 3e Shows a schematic structural diagram of the optical system of the third embodiment at the long-focal end. Figure 3f Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the third embodiment at the long-focal end. According to Figure 3f it can be seen that the optical system given in the third embodiment can achieve good imaging quality.

[0150] Fourth Embodiment

[0151] Please refer to Figures 4a to 4f , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0152] Right-angle prism E, prism E has an incident surface A1, a reflection surface A2, and an exit surface A3. It can be understood that when the light from the object to be photographed enters prism E perpendicularly through the incident surface A1, it can be totally reflected by the reflection surface A2 and turned to the exit surface A3 to exit along the direction of the optical axis and enter the lens part;

[0153] The first lens L1, the first lens L1 has a negative refractive power, and the object side surface S1 and the image side surface S2 of the first lens L1 are both concave surfaces near the optical axis; the object side surface S1 and the image side surface S2 of the first lens L1 are both convex surfaces near the circumference.

[0154] The second lens L2, the second lens L2 has a positive refractive power, and the second lens L2 is glued to the first lens L1. The object side surface S2 and the image side surface S3 of the second lens L2 are both convex surfaces near the optical axis; the object side surface S2 of the second lens L2 is concave near the circumference, and the image side surface S3 is convex near the circumference.

[0155] The third lens L3, the third lens L3 has a positive refractive power, and the object side surface S4 and the image side surface S5 of the third lens L3 are both convex surfaces near the optical axis; the object side surface S4 of the third lens L3 is convex near the circumference, and the image side surface S5 is concave near the circumference.

[0156] The fourth lens L4, the fourth lens has a positive refractive power, and the object side surface S6 and the image side surface S7 of the fourth lens are both convex surfaces near the optical axis; the object side surface S6 and the image side surface S7 of the fourth lens L4 are both concave surfaces near the circumference.

[0157] The fifth lens L5 has a negative refractive power. The object side S7 and the image side S8 of the fifth lens L5 are both concave near the optical axis; the object side S7 and the image side S8 of the fifth lens L5 are both convex near the circumference.

[0158] The sixth lens L6 has a negative refractive power. The object side S9 and the image side S10 of the sixth lens are both concave near the optical axis; the object side S9 and the image side S10 of the sixth lens L6 are both concave near the circumference.

[0159] The seventh lens L7 has a negative refractive power. The object side S11 of the seventh lens L7 is convex near the optical axis, and the image side S12 is concave near the optical axis; the object side S11 of the seventh lens L7 is convex near the circumference, and the image side S12 is concave near the circumference.

[0160] The eighth lens L8 has a positive refractive power. The object side S13 of the eighth lens L8 is concave near the optical axis, and the image side S14 is convex near the optical axis; the object side S13 of the eighth lens L8 is convex near the circumference, and the image side S14 is concave near the circumference.

[0161] The other structures of the fourth embodiment are the same as those of the first embodiment, and can be referred to.

[0162] Tables 4a(1) - 4a(2) show the tables of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative of the thickness value only represent the direction.

[0163] Table 4a(1)

[0164]

[0165]

[0166] Table 4a(2)

[0167] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 8.4385 0.9456 5.9131 13.87 2.85 24.61 30.40 Medium focus position 5.4981 3.2466 5.4528 16.99 3.22 20.03 29.30 Telephoto position 0.0800 12.7536 2.4637 30.49 4.85 11.24 30.40

[0168] Among them, the meanings of the parameters in Table 4a(2) are the same as those of the parameters in the first embodiment.

[0169] Table 4b gives the high-order term coefficients that can be used for each aspherical mirror surface in the fourth embodiment. Among them, each aspherical surface type can be defined by the formula given in the first embodiment.

[0170] Table 4b

[0171]

[0172] Figure 4aShows a schematic structural diagram of the optical system of the fourth embodiment at the short focal end. Figure 4b Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fourth embodiment at the short focal end. According to Figure 4b it can be seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0173] Figure 4c Shows a schematic structural diagram of the optical system of the fourth embodiment at the middle focal end. Figure 4d Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fourth embodiment at the middle focal end. According to Figure 4d it can be seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0174] Figure 4e Shows a schematic structural diagram of the optical system of the fourth embodiment at the long focal end. Figure 4f Shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fourth embodiment at the long focal end. According to Figure 4f it can be seen that the optical system given in the fourth embodiment can achieve good imaging quality.

[0175] Fifth Embodiment

[0176] Please refer to Figures 5a to 5f , the optical system of this embodiment sequentially includes, from the object side to the image side along the optical axis direction:

[0177] A right-angled prism E, the prism E has an incident surface A1, a reflecting surface A2, and an exit surface A3. It can be understood that when the light from the object enters the prism E perpendicularly through the incident surface A1, it can be totally reflected by the reflecting surface A2 and turned to the exit surface A3 to exit along the direction of the optical axis and enter the lens part;

[0178] The first lens L1, the first lens L1 has a negative refractive power, and the object side surface S1 and the image side surface S2 of the first lens L1 are both concave surfaces near the optical axis; the object side surface S1 and the image side surface S2 of the first lens L1 are both convex surfaces near the circumference.

[0179] The second lens L2, the second lens L2 has a positive refractive power, and the second lens L2 is glued to the first lens L1. The object side surface S2 and the image side surface S3 of the second lens L2 are both convex surfaces near the optical axis; the object side surface S2 of the second lens L2 is concave near the circumference, and the image side surface S3 of the second lens L2 is convex near the circumference.

[0180] The third lens L3, the third lens L3 has a positive refractive power, and the object side surface S4 and the image side surface S5 of the third lens L3 are both convex surfaces near the optical axis; the object side surface S4 of the third lens L3 is convex near the circumference, and the image side surface S5 of the third lens L3 is concave near the circumference.

[0181] The fourth lens L4 has a positive refractive power. The object side S6 and the image side S7 of the fourth lens are both convex near the optical axis; the object side S6 and the image side S7 of the fourth lens are both concave near the circumference.

[0182] The fifth lens L5 has a negative refractive power. The object side S7 and the image side S8 of the fifth lens are both concave near the optical axis; the object side S7 and the image side S8 of the fifth lens are both convex near the circumference.

[0183] The sixth lens L6 has a negative refractive power. The object side S9 and the image side S10 of the sixth lens are both concave near the optical axis; the object side S9 and the image side S10 of the sixth lens are both concave near the circumference.

[0184] The seventh lens L7 has a negative refractive power. The object side S11 and the image side S12 of the seventh lens are both concave near the optical axis; the object side S11 of the seventh lens is convex near the circumference, and the image side S12 of the seventh lens is concave near the circumference.

[0185] The eighth lens L8 has a positive refractive power. The object side S13 of the eighth lens is concave near the optical axis, and the image side S14 of the eighth lens is convex near the optical axis; the object side S13 and the image side S14 of the eighth lens are both convex near the circumference.

[0186] The other structures of the fifth embodiment are the same as those of the first embodiment, and can be referred to.

[0187] Tables 5a(1) - 5a(2) show the tables of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative of the thickness value only represent the direction.

[0188] Table 5a(1)

[0189]

[0190] Table 5a(2)

[0191] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 9.8696 2.2813 5.1712 13.87 2.99 24.63 33.50 Medium focus position 6.3765 5.1016 4.5441 17.55 3.44 19.42 32.20 Telephoto position 0.2054 13.4899 3.4080 31.01 5.00 11.09 33.28

[0192] Among them, the meanings of the parameters in Table 5a(2) are the same as those of the parameters in the first embodiment.

[0193] Table 5b gives the high-order term coefficients of the aspherical mirrors that can be used in the fifth embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0194] Table 5b

[0195]

[0196] Figure 5a The structural schematic diagram of the optical system of the fifth embodiment at the short focal end is shown. Figure 5b The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the short focal end are shown. According to Figure 5b it can be known that the optical system given in the fifth embodiment can achieve good imaging quality.

[0197] Figure 5c The structural schematic diagram of the optical system of the fifth embodiment at the middle focal end is shown. Figure 5d The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the middle focal end are shown. According to Figure 5d it can be known that the optical system given in the fifth embodiment can achieve good imaging quality.

[0198] Figure 5e The structural schematic diagram of the optical system of the fifth embodiment at the long focal end is shown. Figure 5f The longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the fifth embodiment at the long focal end are shown. According to Figure 5f it can be known that the optical system given in the fifth embodiment can achieve good imaging quality.

[0199] Sixth Embodiment

[0200] Please refer to Figures 6a to 6f In the optical system of this embodiment, from the object side to the image side along the optical axis direction, it sequentially includes:

[0201] A right-angled prism E, the prism E has an incident surface A1, a reflecting surface A2, and an exit surface A3. It can be understood that when the light from the object to be photographed enters the prism E perpendicularly through the incident surface A1, it can be totally reflected by the reflecting surface A2 and turned to the exit surface A3 to be emitted along the direction of the optical axis and enter the lens part;

[0202] The first lens L1, the first lens L1 has a negative refractive power, and the object side surface S1 and the image side surface S2 of the first lens L1 are both concave near the optical axis; the object side surface S1 and the image side surface S2 of the first lens L1 are both convex near the circumference.

[0203] The second lens L2, the second lens L2 has a positive refractive power, and the second lens L2 is glued to the first lens L1. The object side surface S2 and the image side surface S3 of the second lens L2 are both convex near the optical axis; the object side surface S2 of the second lens L2 is concave near the circumference, and the image side surface S3 is convex near the circumference.

[0204] The third lens L3 has a positive refractive power. The object side S4 and the image side S5 of the third lens L3 are both convex near the optical axis; the object side S4 of the third lens L3 is convex near the circumference, and the image side S5 is concave near the circumference.

[0205] The fourth lens L4 has a positive refractive power. The object side S6 and the image side S7 of the fourth lens are both convex near the optical axis; the object side S6 and the image side S7 of the fourth lens are both concave near the circumference.

[0206] The fifth lens L5 has a negative refractive power. The object side S7 and the image side S8 of the fifth lens L5 are both concave near the optical axis; the object side S7 and the image side S8 of the fifth lens L5 are both convex near the circumference.

[0207] The sixth lens L6 has a negative refractive power. The object side S9 and the image side S10 of the sixth lens are both concave near the optical axis; the object side S9 of the sixth lens is convex near the circumference, and the image side S10 is concave near the circumference.

[0208] The seventh lens L7 has a negative refractive power. The object side S11 of the seventh lens L7 is convex near the optical axis, and the image side S12 is concave near the optical axis; the object side S11 of the seventh lens L7 is concave near the circumference, and the image side S12 is convex near the circumference.

[0209] The eighth lens L8 has a positive refractive power. The object side S13 and the image side S14 of the eighth lens L8 are both convex near the optical axis; the object side S13 of the eighth lens L8 is convex near the circumference, and the image side S14 is concave near the circumference.

[0210] The other structures of the sixth embodiment are the same as those of the first embodiment, and can be referred to.

[0211] Tables 6a(1) - 6a(2) show the tables of the characteristics of the optical system of this embodiment. Among them, the focal length, material refractive index, and Abbe number are all obtained from visible light with a reference wavelength of 587.6 nm. The units of the Y radius, thickness, and effective focal length are all millimeters (mm), and the positive and negative of the thickness value only represent the direction.

[0212] Table 6a(1)

[0213]

[0214]

[0215] Table 6a(2)

[0216] Variable distance D1 D2 D3 EFL (mm) FNO FOV (°) TTL (mm) Short focus position 9.3622 1.1774 6.1297 14.51 3.11 23.59 33.50 Medium focus position 5.6181 5.2911 4.6349 19.18 3.70 17.78 32.37 Telephoto position 0.0800 13.9728 2.6165 32.98 5.33 10.39 33.50

[0217] Among them, the meanings of the parameters in Table 6a(2) are the same as those of the parameters in the first embodiment.

[0218] Table 6b gives the high-order term coefficients of the aspherical mirrors that can be used in the sixth embodiment. Among them, the aspherical surface types can be defined by the formulas given in the first embodiment.

[0219] Table 6b

[0220]

[0221]

[0222] Figure 6a shows a schematic structural diagram of the optical system of the sixth embodiment at the short focal end. Figure 6b shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the short focal end. According to Figure 6b it can be known that the optical system given in the sixth embodiment can achieve good imaging quality.

[0223] Figure 6c shows a schematic structural diagram of the optical system of the sixth embodiment at the medium focal end. Figure 6d shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the medium focal end. According to Figure 6d it can be known that the optical system given in the sixth embodiment can achieve good imaging quality.

[0224] Figure 6e shows a schematic structural diagram of the optical system of the sixth embodiment at the long focal end. Figure 6f shows the longitudinal spherical aberration curve, astigmatism curve, and distortion curve of the optical system of the sixth embodiment at the long focal end. According to Figure 6f it can be known that the optical system given in the sixth embodiment can achieve good imaging quality.

[0225] Table 7 shows the values of Fc / Fd, FOVc / ImgH, D2c / D2d, et12 / ct12, fg3 / g3, Fc / (f3 + |fjh2|), |R71| / R82, and f8 / ct8 in the optical systems of the first to sixth embodiments.

[0226] Table 7

[0227] Fc / Fd FOVc / ImgH D2c / D2d et12 / ct12 First embodiment 2.29 3.85 9.78 4.21 Second embodiment 2.22 3.81 6.98 3.95 Third embodiment 2.40 3.82 13.59 7.11 Fourth embodiment 2.20 3.75 13.49 4.88 Fifth embodiment 2.24 3.70 5.91 2.84 Sixth embodiment 2.27 3.46 11.87 4.90 fg3 / g3 Fc / (f3 + |fjh2|) |R71| / R82 f8 / ct8 First embodiment 4.21 1.09 -1.52 8.14 Second embodiment 5.87 1.09 -2.01 48.87 Third embodiment 4.09 1.10 -1.76 7.51 Fourth embodiment 6.64 1.15 -5.05 24.43 Fifth embodiment 5.10 1.16 -1.86 5.19 Sixth embodiment 7.01 1.25 -1.34 11.61

[0228] As can be seen from Table 7, the optical systems of the first to sixth embodiments all satisfy the following conditional expressions: Fc / Fd≥2.2, FOVc / ImgH<3.9, 5.5<D2c / D2d<14, 2.5<et12 / ct12<7.5, 4<fg3 / g3<7.5, 1<Fc / (f3+|fjh2|)<1.3, -1.2>|R71| / R82>-5.2, 5<f8 / ct8<50.

[0229] The above-disclosed is only a preferred embodiment of the present invention. Of course, the scope of rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. An optical system, characterized in that, The number of lenses with refractive power in the optical system is eight, which sequentially includes along the optical axis from the object side to the image side: A right-angle prism, the right-angle prism includes an incident light surface, a reflection surface, and an exit light surface, the incident light surface and the exit light surface are perpendicularly connected, the reflection surface connects the incident light surface and the exit light surface, light enters the incident light surface perpendicularly and is totally reflected by the reflection surface and then exits from the exit light surface; A first lens group, opposite to the exit light surface and having a negative refractive power, includes a first lens and a second lens sequentially arranged along the optical axis, the first lens has a negative refractive power, and the second lens has a positive refractive power; A second lens group, having a positive refractive power, includes a third lens, a fourth lens, and a fifth lens sequentially arranged along the optical axis, the third lens has a positive refractive power, the fourth lens has a positive refractive power, and the fifth lens has a negative refractive power; A third lens group, having a positive refractive power, includes a sixth lens, a seventh lens, and an eighth lens sequentially arranged along the optical axis, the sixth lens has a negative refractive power, and the eighth lens has a positive refractive power; The first lens to the eighth lens include at least one aspherical plastic lens; The optical system is a zoom optical system, and the zoom optical system is provided with a telephoto end and a wide-angle end; The optical system satisfies the conditional formula: 5.5 < D2c / D2d < 14; Wherein, D2c is the distance on the optical axis between the image side surface of the fifth lens and the object side surface of the sixth lens when the optical system is at the telephoto end; D2d is the distance on the optical axis between the image side surface of the fifth lens and the image side surface of the sixth lens when the optical system is at the wide-angle end.

2. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 2.4 ≥ Fc / Fd ≥ 2.2; Wherein, Fc is the effective focal length of the optical system at the telephoto end, and Fd is the effective focal length of the optical system at the wide-angle end.

3. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: FOVc / ImgH < 3.9; Wherein, FOVc is the maximum field of view angle of the optical system at the telephoto end, and ImgH is half of the diagonal length of the effective photosensitive area on the imaging surface.

4. The optical system according to claim 1, characterized in that The optical system satisfies the conditional formula: 2.5 < et12 / ct12 < 7.5; Wherein, et12 is the horizontal distance at the effective diameter between the image side surface of the second lens and the object side surface of the third lens, and ct12 is the distance on the optical axis between the image side surface of the second lens and the object side surface of the third lens.

5. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 4 < fg3 / g3 < 7.5; Wherein, fg3 is the effective focal length of the third lens group, and g3 is the distance on the optical axis between the object side surface of the sixth lens and the image side surface of the eighth lens.

6. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 1 < Fc / (f3 + |fjh2|) < 1.3; Wherein, Fc is the effective focal length of the optical system at the telephoto end, f3 is the effective focal length of the third lens; fjh2 is the combined effective focal length of the fourth lens and the fifth lens, and the fourth lens and the fifth lens are glued together to form a glued lens.

7. The optical system according to claim 1, wherein The optical system satisfies the conditional formula: -1.2 > |R71| / R82 > -5.2; Wherein, R71 is the curvature radius value of the object side surface of the seventh lens on the optical axis, and R82 is the curvature radius of the image side surface of the eighth lens on the optical axis.

8. The optical system according to claim 1, characterized in that, The optical system satisfies the conditional formula: 5 < f8 / ct8 < 50; Wherein, f8 is the effective focal length of the eighth lens, and ct8 is the thickness of the eighth lens on the optical axis.

9. An imaging module, characterized in that, It includes a lens barrel, an electronic photosensitive element, and the optical system according to any one of claims 1 to 8. The first lens to the eighth lens of the optical system are all installed in the lens barrel, and the electronic photosensitive element is arranged on the image side of the optical system.

10. An electronic device, characterized in that, It includes a housing and the imaging module according to claim 9. The imaging module is arranged in the housing.

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