CN213957728U

CN213957728U - Optical system, camera module and electronic equipment

Info

Publication number: CN213957728U
Application number: CN202023100505.5U
Authority: CN
Inventors: 华露; 杨健; 李明
Original assignee: Jiangxi Jingchao Optical Co Ltd
Current assignee: Jiangxi Jingchao Optical Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-08-13
Anticipated expiration: 2030-12-21

Abstract

An optical system, a camera module and an electronic device, the optical system sequentially comprises, from an object side to an image side along an optical axis direction: the right-angle prism comprises a light incident surface, a reflecting surface and a light emergent surface, and light rays vertically enter the light incident surface and are totally reflected by the reflecting surface to be emitted from the light emergent surface; first to eighth lenses, at least one of which is an aspherical plastic lens; the first lens element and the second lens element form a first lens assembly with negative refractive power, the third lens element to the fifth lens element form a second lens assembly with positive refractive power, and the sixth lens element to the eighth lens element form a third lens assembly with positive refractive power. The right-angle prism is arranged to deflect light rays to form a folding periscopic structure, and the refractive power from the first lens to the eighth lens is reasonably set, so that the transverse distance is shortened, and the occupied space of an optical system is reduced; on the other hand, sufficient length is provided for the optical system to achieve a wide range of zoom.

Description

Optical system, camera module and electronic equipment

Technical Field

The utility model belongs to the technical field of optical imaging, especially, relate to an optical system, module and electronic equipment make a video recording.

Background

In recent years, many mobile phones having 3-camera and 4-camera lenses are available, and such mobile phones can achieve the effects of ultra-clear shooting, wide-angle shooting, telephoto shooting, and the like by switching different lenses. On one hand, the lens configuration meets the photographing requirements of users in different scenes, and on the other hand, there are some disadvantages, for example, to obtain a high zoom ratio characteristic, the total length of the optical system is also correspondingly lengthened, but limited mobile phone space is still available, so how to further shorten the total length of the optical system, and realizing large-range zooming while realizing miniaturization becomes one of the problems to be solved in the industry at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an optical system, module and electronic equipment make a video recording can satisfy simultaneously and zoom on a large scale and miniaturized requirement.

For realizing the purpose of the utility model, the utility model provides a following technical scheme:

in a first aspect, the present invention provides an optical system, which includes, in order from an object side to an image side along an optical axis: the right-angle prism comprises a light incident surface, a reflecting surface and a light emitting surface, the light incident surface is vertically connected with the light emitting surface, the reflecting surface is connected with the light incident surface and the light emitting surface, and light rays vertically enter the light incident surface and are emitted from the light emitting surface after being totally reflected by the reflecting surface; the first lens group is opposite to the light emergent surface, has negative refractive power and comprises a first lens and a second lens which are sequentially arranged along the optical axis; the second lens group has positive refractive power and comprises a third lens, a fourth lens and a fifth lens which are sequentially arranged along the optical axis; the third lens group has positive refractive power and comprises a sixth lens, a seventh lens and an eighth lens which are sequentially arranged along the optical axis; the first lens to the eighth lens include at least one aspherical plastic lens.

The right-angle prism is arranged to deflect light rays to form a folding periscopic structure, and the folding periscopic structure is reasonably arranged through the refractive power from the first lens to the eighth lens, so that the transverse 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 wide range of zoom.

In one embodiment, the optical system is a zoom optical system having a long focal end and a short focal end. By enabling the optical system to be in two states of a long-focus end and a short-focus end respectively, relevant parameters of the optical system can be designed and adjusted, and the purpose of improving the imaging quality of the optical system is achieved.

In one embodiment, the optical system satisfies the conditional expression: Fc/Fd is more than or equal to 2.2; and Fc is the effective focal length of the optical system at the long focal end, and Fd is the effective focal length of the optical system at the short focal end. The optical system can obtain a higher zoom ratio by reasonably configuring the ratio of the effective focal length of the long focal end to the effective focal length of the short focal end, thereby realizing large-range shooting magnification, realizing the characteristic of continuous zooming of the zoom lens group and ensuring that the zoom lens group obtains good imaging quality. When Fc/Fd <2.2, the continuous zoom range is not sufficient to meet the user's higher requirements for the shooting experience.

In one embodiment, the optical system satisfies the conditional expression: FOVc/ImgH < 3.9; the FOVc is a full field angle of the optical system at the telephoto end, and the ImgH is half of a diagonal length of an effective photosensitive area on an imaging surface, namely half of an image height. The ratio of the full field angle of the telephoto end to the half-image height is configured to be within a reasonable range, thereby being beneficial to realizing the telephoto characteristic of the telephoto end of the optical system, and simultaneously being capable of matching with a chip with higher pixels to realize high-definition shooting.

In one embodiment, the optical system satisfies the conditional expression: 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 between the image-side surface of the fifth lens and the image-side surface of the sixth lens on the optical axis when the optical system is at the short focal end. Satisfy above-mentioned relational expression, when being in long focus end and short focus end through control optical system the image side of fifth lens with the ratio of the object side of sixth lens and the distance of image side on the optical axis is favorable to making optical system obtains bigger zoom range, realizes the shooting effect of bigger multiplying power, and is reasonable in addition the image side of fifth lens with the distance control of the image side of sixth lens on the optical axis also can reduce optical system's processing equipment degree of difficulty, further promotes the processability. When D2c/D2D is less than or equal to 5.5, the zoom range of the optical system is not widened; when D2c/D2D is equal to or greater than 14, the distance between the second lens group and the third lens group in the short focus state is too small, which increases the difficulty of assembly and also makes it easy for the lens to be out of the way or collide with the lens when continuous zooming is performed.

In one embodiment, the optical system satisfies the conditional expression: 2.5< et12/ct12< 7.5; wherein et12 is a horizontal distance from the image-side surface of the second lens to the object-side surface of the third lens at the effective diameter, and ct12 is a distance from the image-side surface of the second lens to the object-side surface of the third lens on the optical axis. Satisfying above-mentioned relational expression, through making the ratio of first lens battery and second lens battery middle and marginal interval keep in reasonable scope, be favorable to marginal light with less reasonable angle from first lens battery transition to the second lens battery, be favorable to the second lens battery rectifies the aberration of first lens battery simultaneously, still is favorable to the molding manufacturing and processing equipment in addition. When et12/ct12 is less than or equal to 2.5, the distance between the first lens group and the second lens group at the effective diameter is too large, so that the deflection angle of light rays entering the second lens group is too large; et12/ct12 is more than or equal to 7.5, the distance between the effective diameters of the first lens group and the second lens group is too small, processing and assembling are not facilitated, and assembling difficulty is increased.

In one embodiment, the optical system satisfies the conditional expression: 4< fg3/g3< 7.5; wherein fg3 is an effective focal length of the third lens group, and g3 is a distance on an optical axis from an object-side surface of the sixth lens to an image-side surface of the eighth lens. The third lens group bears part of positive refractive power, the proportion of the positive refractive power contributed by the third lens group to the optical system is controlled, the aberration generated by the first lens group with the negative refractive power is corrected, and the imaging quality of the optical system is improved; in addition, the total length of the third lens group is controlled, so that the total length of the optical system can be shortened, and the miniaturization of the optical system can be realized. When fg3/g3 is greater than or equal to 7.5, the third lens group does not provide enough positive refractive power, which is not beneficial to correcting the aberration generated by the front lens group and influences the imaging quality; when fg3/g3 is less than or equal to 4, the total length of the third lens group is too long, which is not beneficial to shortening the total length of the optical system.

In one embodiment, the optical system satisfies the conditional expression: 1< Fc/(f3+ fjh2) < 1.3; wherein Fc is an effective focal length of the optical system at the tele end, and f3 is an 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 cemented to form a cemented lens. When the above relation is satisfied, the ratio of the effective focal length of the telephoto end to the sum of the effective focal lengths of the third lens and the cemented lens is reasonably configured, which is beneficial to realizing the telephoto characteristic and expanding the zoom ratio of the optical system; in addition, the second lens group bears positive refractive power required by the optical system, so that spherical aberration generated by the front lens group can be effectively corrected, and the resolution power of the optical system can be improved.

In one embodiment, the optical system satisfies the conditional expression: 1.2< | R71|/R82< 5.2; wherein R71 is a curvature radius value of an object-side surface of the seventh lens element on an optical axis, and R82 is a curvature radius value of an image-side surface of the eighth lens element on the optical axis. 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 is controlled within a reasonable range, so that the shapes of the seventh lens and the eighth lens can be effectively constrained, the seventh lens and the eighth lens are mutually matched to contribute to aberration together, and the imaging quality of the optical system is improved. When the absolute value of R71/R82 is less than or equal to 1.2 or the absolute value of R71/R82 is more than or equal to 5.2, the aberration provided by the combination of the shapes of the seventh lens and the eighth lens can not enable the whole aberration of the optical system to reach a reasonable balance state.

In one embodiment, the optical system satisfies the conditional expression: 5< f8/ct8< 50; wherein f8 is an effective focal length of the eighth lens, and ct8 is a thickness of the eighth lens on an optical axis, i.e., a middle thickness. Satisfying the above relation, by reasonably configuring the ratio of the effective focal length of the eighth lens to the thickness of the eighth lens, on one hand, the aberration distributed to the eighth lens by the whole optical system can be controlled, so that the aberration of the optical system is in a reasonable horizontal state and good imaging quality is obtained, and on the other hand, the total length of the optical system can be further shortened, the shape of the eighth lens is constrained, so that the optical system has good processing performance.

In a second aspect, the present invention further provides a camera module, the camera module includes a lens barrel, an electronic photosensitive element and the optical system as in the above embodiments, the optical system has the first lens to the eighth lens installed in the lens barrel, the electronic photosensitive element is installed on the image side of the optical system, and the right-angle prism is used to pass through the light beam of the object on the electronic photosensitive element incident to the eighth lens, and the light beam is converted into an electrical signal of an image. The utility model discloses an install this optical system's rectangular prism to eighth lens in the module of making a video recording, the face type and the power of refracting of each lens of the first lens of rational configuration to eighth lens can be so that the module of making a video recording satisfies simultaneously on a large scale zoom and miniaturized requirement.

A third aspect, the utility model also provides an electronic equipment, this electronic equipment include casing and second aspect the module of making a video recording, the module setting of making a video recording is in the casing. Through adding in electronic equipment the utility model provides a module of making a video recording for electronic equipment satisfies simultaneously and zooms on a large scale and miniaturized requirement.

To sum up, the utility model discloses a right angle prism that the light path trend can be changed in the setting to can transversely arrange the module of making a video recording in the electronic equipment shell during the installation, can reduce the horizontal length and the whole height of the module of making a video recording, satisfy pixel quantity increase gradually, the scope of zooming enlarges gradually and optics gets for instance the miniaturized requirement of camera lens, and then realize electronic equipment's miniaturized requirement.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1a is a schematic diagram of the optical system of the first embodiment at the short focal end;

FIG. 1b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the first embodiment at the short focal end;

FIG. 1c is a schematic diagram of the optical system of the first embodiment at the mid-focal end;

FIG. 1d is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the first embodiment at the mid-focal end;

FIG. 1e is a schematic diagram of the optical system of the first embodiment at the tele end;

FIG. 1f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the first embodiment at the tele end;

FIG. 2a is a schematic diagram of the optical system of the second embodiment at the short focal end;

FIG. 2b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the second embodiment at the short focal end;

FIG. 2c is a schematic diagram of the optical system of the second embodiment at the mid-focal end;

FIG. 2d is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the second embodiment at the middle focal end;

FIG. 2e is a schematic diagram of the optical system of the second embodiment at the tele end;

FIG. 2f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the second embodiment at the tele end;

FIG. 3a is a schematic diagram of the optical system of the third embodiment at the short focal end;

FIG. 3b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the third embodiment at the short focal end;

FIG. 3c is a schematic diagram of the optical system of the third embodiment at the mid-focal end;

FIG. 3d is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the third embodiment at the middle focal end;

FIG. 3e is a schematic diagram of the optical system of the third embodiment at the tele end;

FIG. 3f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the third embodiment at the tele end;

FIG. 4a is a schematic diagram of the optical system of the fourth embodiment at the short focal end;

FIG. 4b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fourth embodiment at the short focal end;

FIG. 4c is a schematic diagram of the optical system of the fourth embodiment at the mid-focal end;

FIG. 4d is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fourth embodiment at the middle focal end;

FIG. 4e is a schematic diagram of the optical system of the fourth embodiment at the tele end;

FIG. 4f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the fourth embodiment at the tele end;

FIG. 5a is a schematic diagram of the optical system of the fifth embodiment at the short focal end;

FIG. 5b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fifth embodiment at the short focal end;

FIG. 5c is a schematic diagram of the optical system of the fifth embodiment at the mid-focal end;

FIG. 5d is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fifth embodiment at the middle focal end;

FIG. 5e is a schematic diagram of the optical system of the fifth embodiment at the tele end;

FIG. 5f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the fifth embodiment at the tele end;

FIG. 6a is a schematic diagram of the optical system of the sixth embodiment at the short focal end;

FIG. 6b is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the sixth embodiment at the short focal end;

FIG. 6c is a schematic diagram of the optical system of the sixth embodiment at the mid-focal end;

FIG. 6d is a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the sixth embodiment at the middle focal end;

FIG. 6e is a schematic diagram of the optical system of the sixth embodiment at the tele end;

fig. 6f is a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the sixth embodiment at the telephoto end.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention.

The utility model provides an optical system, follow the object side to the image side and contain in proper order along the optical axis: the right-angle prism comprises a light incident surface, a reflecting surface and a light emitting surface, the light incident surface is vertically connected with the light emitting surface, the reflecting surface is connected with the light incident surface and the light emitting surface, and light rays vertically enter the light incident surface and are emitted from the light emitting surface after being totally reflected by the reflecting surface; the first lens group is opposite to the light emergent surface, has negative refractive power and comprises a first lens and a second lens which are sequentially arranged along an optical axis; the second lens group has positive refractive power and comprises a third lens, a fourth lens and a fifth lens which are sequentially arranged along an optical axis; the third lens group has positive refractive power and comprises a sixth lens, a seventh lens and an eighth lens which are sequentially arranged along an optical axis; the first lens to the eighth lens include at least one aspherical plastic lens.

The right-angle prism is arranged to deflect light rays to form a folding periscopic structure, and the refractive power from the first lens to the eighth lens is reasonably set, so that the transverse distance is shortened, and the occupied space of an optical system is reduced; on the other hand, sufficient length is provided for the optical system to achieve a wide range of zoom.

In one embodiment, the optical system is a zoom optical system, and the zoom optical system is provided with a long focal end and a short focal end. Wherein the long focus end is a state when the focal length of the optical system is maximum, and the short focus end is a state when the focal length of the optical system is minimum. By enabling the optical system to be in two states of a long-focus end and a short-focus end, relevant parameters of the optical system can be designed and adjusted, and the purpose of improving the imaging quality of the optical system is achieved.

In one embodiment, the optical system satisfies the conditional expression: FOVc/ImgH < 3.9; wherein, FOVc is the full field 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 plane, i.e. half the image height. The relation is satisfied, the ratio of the full field angle of the telephoto end to the half-image height is configured to be within a reasonable range, the telephoto characteristic of the optical system at the telephoto end is facilitated, and meanwhile, a chip with higher pixels can be matched, and high-definition shooting is achieved.

In one embodiment, the optical system satisfies the conditional expression: 5.5< D2c/D2D < 14; wherein D2c is the distance between the image-side surface of the fifth lens and the object-side surface of the sixth lens on the optical axis when the optical system is at the telephoto end; D2D is the distance between the image side surface of the fifth lens and the image side surface of the sixth lens on the optical axis when the optical system is at the short focal end. Satisfy above-mentioned relational expression, through the ratio of the distance on the optical axis of the image side face of control optical system at long focal end and short focal end time fifth lens and the object side face and the image side face of sixth lens, be favorable to making optical system obtain bigger zoom range, realize the shooting effect of bigger multiplying power, reasonable distance control on the optical axis of the image side face of fifth lens and the image side face of sixth lens in addition also can reduce optical system's processing equipment degree of difficulty, further promote the processability. When D2c/D2D is less than or equal to 5.5, the zoom range of the optical system is not widened; when D2c/D2D is equal to or greater than 14, the distance between the second lens group and the third lens group in the short focus state is too small, which increases the difficulty of assembly and tends to cause a problem of a failure or lens collision in continuous zooming.

In one embodiment, the optical system satisfies the conditional expression: 2.5< et12/ct12< 7.5; where et12 is the horizontal distance from the image-side surface of the second lens to the object-side surface of the third lens at the effective diameter, and ct12 is the distance from the image-side surface of the second lens to the object-side surface of the third lens on the optical axis. Satisfy above-mentioned relational expression, through make first lens battery and second lens battery middle and marginal interval's ratio keep in reasonable within range, be favorable to marginal light to pass through to the second lens battery from first lens battery with less reasonable angle, be favorable to the second lens battery to rectify the aberration of first lens battery simultaneously, still be favorable to the shaping manufacturing and process the equipment in addition. When et12/ct12 is less than or equal to 2.5, the distance between the effective diameters of the first lens group and the second lens group is too large, so that the deflection angle of light rays entering the second lens group is too large; when et12/ct12 is larger than or equal to 7.5, the distance between the effective diameters of the first lens group and the second lens group is too small, processing and assembling are not facilitated, and assembling difficulty is increased. The distance between the first lens group and the second lens group at the effective diameter is the distance from the effective diameter of the image side surface of the second lens to the effective diameter of the object side surface of the third lens in the optical axis direction.

In one embodiment, the optical system satisfies the conditional expression: 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 from the object-side surface of the sixth lens element to the image-side surface of the eighth lens element. The third lens group bears part of positive refractive power, the proportion of the positive refractive power contributed by the third lens group to the optical system is controlled, the aberration generated by the first lens group with the negative refractive power is corrected, and the imaging quality of the optical system is improved; in addition, the total length of the third lens group is controlled, so that the total length of the optical system can be shortened, and the miniaturization of the optical system can be realized. When fg3/g3 is greater than or equal to 7.5, the third lens group does not provide enough positive refractive power, which is not favorable for correcting the aberration generated by the front lens group and influences the imaging quality; when fg3/g3 is less than or equal to 4, the total length of the third lens group is too long, which is not favorable for shortening the total length of the optical system.

In one embodiment, the optical system satisfies the conditional expression: 1< Fc/(f3+ fjh2) < 1.3; wherein Fc is an effective focal length of the optical system at the telephoto end, and f3 is an 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 cemented to form a cemented lens. When the relation is satisfied, the ratio of the effective focal length of the telephoto end to the sum of the effective focal lengths of the third lens and the cemented lens is reasonably configured, so that the realization of the telephoto characteristic is facilitated, and the zoom ratio of the optical system is also facilitated to be enlarged; in addition, the second lens group bears positive refractive power required by the optical system, so that spherical aberration generated by the front lens group can be effectively corrected, and the resolution power of the optical system can be improved.

In one embodiment, the optical system satisfies the conditional expression: 1.2< | R71|/R82< 5.2; wherein, R71 is a curvature radius value of the object-side surface of the seventh lens element on the optical axis, and R82 is a curvature radius value of the image-side surface of the eighth lens element on the optical axis. 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 is controlled within a reasonable range, so that effective constraint on the shapes of the seventh lens and the eighth lens can be realized, the seventh lens and the eighth lens are mutually matched to jointly contribute to aberration, and the imaging quality of the optical system is improved. When the absolute value of R71/R82 is less than or equal to 1.2 or the absolute value of R71/R82 is more than or equal to 5.2, the aberration provided by the combination of the shapes of the seventh lens and the eighth lens can not enable the whole aberration of the optical system to reach a reasonable balance state.

In one embodiment, the optical system satisfies the conditional expression: 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 thickness of the middle lens. Satisfying above-mentioned relational expression, through the effective focal length of rational configuration eighth lens and the thick ratio in the eighth lens, can control the aberration that whole optical system distributes to the eighth lens on the one hand, make optical system aberration be in reasonable horizontality and then obtain good image quality, on the other hand can help further shortening optical system's overall length, retrain the shape of eighth lens, make optical system have good processing performance.

The embodiment of the utility model provides a camera module, this camera module include lens cone, electron photosensitive element and the utility model provides an optical system, first lens to eighth lens are all installed in the lens cone, and electron photosensitive element sets up the image side at optical system for the signal of telecommunication that the light that will pass the object that right angle prism to eighth lens incide on the electron photosensitive element converts the image into. The electron sensor may be a Complementary Metal Oxide Semiconductor (CMOS) or a Charge-coupled Device (CCD). The camera module can be an independent lens of a digital camera and also can be an imaging module integrated on electronic equipment such as a smart phone. The utility model discloses an install this optical system's rectangular prism to eighth lens in the module of making a video recording, the face type and the power of refracting of each lens of the first lens of rational configuration to eighth lens can be so that the module of making a video recording satisfies simultaneously on a large scale zoom and miniaturized requirement.

The embodiment of the utility model provides an electronic equipment, this electronic equipment include the casing with the embodiment of the utility model provides a module of making a video recording. The camera module and the electronic photosensitive element are arranged in the shell. The electronic device can be a smart phone, a Personal Digital Assistant (PDA), a tablet computer, a smart watch, an unmanned aerial vehicle, an electronic book reader, a vehicle event data recorder, a wearable device and the like. Through adding in electronic equipment the utility model provides a module of making a video recording for electronic equipment satisfies simultaneously and zooms on a large scale and miniaturized requirement.

First embodiment

Referring to fig. 1a to fig. 1f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

a right angle prism E having an entrance face a1, a reflection face a2, and an exit face A3. It is understood that, when light from a subject vertically enters the prism E via the incident surface a1, it can be totally reflected by the reflecting surface a2 to the exit surface A3 to exit in the direction of the optical axis and enter the lens portion;

the first lens element L1, the first lens element L1 with negative refractive power, the object-side surface S1 and the image-side surface S2 of the first lens element L1 are both concave at the paraxial region; the object-side surface S1 and the image-side surface S2 of the first lens element L1 are convex near the circumference.

The second lens element L2 with positive refractive power is cemented with the first lens element L1 by a second lens element L2. Since the second lens L2 is cemented with the first lens L1, the object-side surface of the second lens L2 coincides with the image-side surface S2 of the first lens L1, and in this embodiment and other embodiments, the object-side surface of the second lens L2 is still denoted by S2. The object-side surface S2 and the image-side surface S3 of the second lens element L2 are convex at the paraxial region; the object-side surface S2 of the second lens element L2 is concave at the near circumference, and the image-side surface S3 is convex at the near circumference.

The third lens element L3 with positive refractive power has a convex object-side surface S4 and an convex image-side surface S5 at paraxial region of the third lens element L3; the object-side surface S4 of the third lens element L3 is convex near the circumference, and the image-side surface S5 is concave near the circumference.

The fourth lens element L4 with positive refractive power has a convex object-side surface S6 and a convex image-side surface S7 at paraxial region; the object-side surface S6 and the image-side surface S7 of the fourth lens L4 are both concave near the circumference.

The fifth lens element L5 with negative refractive power has the object-side surface of the fifth lens element L5 coinciding with the image-side surface S7 of the fourth lens element L4 because the fifth lens element L5 is cemented with the fourth lens element L4, and in this embodiment and other embodiments, the object-side surface of the fifth lens element L5 is still indicated as S7. The object-side surface S7 and the image-side surface S8 of the fifth lens element L5 are both concave at the paraxial region; the object-side surface S7 and the image-side surface S8 of the fifth lens L5 are convex near the circumference.

The sixth lens element L6 with negative refractive power has a concave object-side surface S9 and a concave image-side surface S10 at a paraxial region; the object-side surface S9 and the image-side surface S10 of the sixth lens L6 are both concave near the circumference.

The seventh lens element L7 with negative refractive power has a convex object-side surface S11 at a paraxial region and a concave image-side surface S12 at a paraxial region of the seventh lens element L7; the object-side surface S11 of the seventh lens element L7 is concave at the near circumference, and the image-side surface S12 is convex at the near circumference.

The eighth lens element L8 with positive refractive power has a convex object-side surface S13 and an convex image-side surface S14 at paraxial region of the eighth lens element L8; the object-side surface S13 of the eighth lens element L8 is convex near the circumference, and the image-side surface S14 is concave near the circumference.

The first lens L1 to the eighth lens L8 are made of plastic or glass. At least one lens of the first lens L1 to the eighth lens L8 is an aspherical plastic lens.

Further, the optical system includes a stop STO, an infrared cut filter IR, and an imaging surface IMG. The stop STO in the present embodiment is provided between the second lens L2 and the third lens L3 for controlling the amount of light entering. In other embodiments, the stop STO can be disposed between two adjacent lenses or on other lenses. The infrared cut filter IR is disposed between the image side surface S14 and the image side surface IMG of the eighth lens L8, and includes an object side surface S15 and an image side surface S16, and is configured to filter infrared light, so that the light incident on the image side surface IMG is visible light, and the wavelength of the visible light is 380nm to 780 nm. The infrared cut-off filter is made of GLASS (GLASS), and can be coated with a film on the GLASS. The effective pixel area of the electronic photosensitive element is positioned on the imaging surface IMG.

Tables 1a (1) -1 a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are all millimeters (mm), and the positive and negative of the thickness value represent directions only.

TABLE 1a (1)

TABLE 1a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	9.7871	1.3209	5.5264	13.00	2.80	26.47	33.20
Position of middle focus	5.5359	5.4542	4.3427	17.82	3.43	19.21	31.90
								Position of long focus	0.1000	12.9164	3.0176	29.75	4.83	11.55	32.60

D1, D2, and D3 are all on-axis distances from the current surface to the next surface, EFL is an effective focal length of the optical system, FNO is an f-number of the optical system, FOV is a maximum field angle of the optical system, and TTL is an on-axis distance from the object-side surface S1 of the first lens L1 to the image plane IMG.

In the present embodiment, the object-side surface and the image-side surface of the first lens element L1 through the eighth lens element L8 are aspheric surfaces, and the aspheric surface x can be defined by, but is not limited to, the following aspheric surface formula:

wherein x is the rise of the distance from the aspheric surface vertex to the aspheric surface vertex when the aspheric surface is at the position with the height of h along the optical axis direction; c is the paraxial curvature of the aspheric surface, c being 1/R (i.e., paraxial curvature c is the reciprocal of the radius R of Y in table 1a (1) above); k is a conic coefficient; ai is a correction coefficient of the i-th order of the aspherical surface. Table 1b shows the high-order term coefficients a4, a6, A8, a10, a12, a14, a16, a18, and a20 that can be used for the aspherical mirrors S1 through S14 in the first embodiment.

TABLE 1b

Fig. 1a shows a schematic configuration of the optical system of the first embodiment at the short focal end. Fig. 1b shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the first embodiment at the short focal end. The longitudinal spherical aberration curve represents the deviation of the convergence focus of the light rays with different wavelengths after passing through each lens of the optical system; the astigmatism curves represent meridional image surface curvature and sagittal image surface curvature; the distortion curve represents the distortion magnitude values corresponding to different angles of view. As can be seen from fig. 1b, the optical system according to the first embodiment can achieve good imaging quality.

Fig. 1c shows a schematic configuration of the optical system of the first embodiment at the mid-focal end. Fig. 1d shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment at the mid-focal end. The longitudinal spherical aberration curve represents the deviation of the convergence focus of the light rays with different wavelengths after passing through each lens of the optical system; the astigmatism curves represent meridional image surface curvature and sagittal image surface curvature; the distortion curve represents the distortion magnitude values corresponding to different angles of view. As can be seen from fig. 1d, the optical system according to the first embodiment can achieve good imaging quality.

Fig. 1e shows a schematic configuration of the optical system of the first embodiment at the tele end. Fig. 1f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the first embodiment at the tele end. The longitudinal spherical aberration curve represents the deviation of the convergence focus of the light rays with different wavelengths after passing through each lens of the optical system; the astigmatism curves represent meridional image surface curvature and sagittal image surface curvature; the distortion curve represents the distortion magnitude values corresponding to different angles of view. As can be seen from fig. 1f, the optical system according to the first embodiment can achieve good imaging quality.

Second embodiment

Referring to fig. 2a to 2f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

The second lens element L2 with positive refractive power is cemented with the first lens element L1 by a second lens element L2. The object-side surface S2 and the image-side surface S3 of the second lens element L2 are convex at the paraxial region; the object-side surface S2 of the second lens element L2 is concave at the near circumference, and the image-side surface S3 is convex at the near circumference.

The fifth lens element L5 with negative refractive power has a concave object-side surface S7 and a concave image-side surface S8 at paraxial region of the fifth lens element L5; the object-side surface S7 and the image-side surface S8 of the fifth lens L5 are convex near the circumference.

The seventh lens element L7 with negative refractive power has a convex object-side surface S11 and an convex image-side surface S12 at paraxial region of the seventh lens element L7; the object-side surface S11 of the seventh lens element L7 is convex near the circumference, and the image-side surface S12 is concave near the circumference.

The eighth lens element L8 with positive refractive power has a concave object-side surface S13 at a paraxial region and a convex image-side surface S14 at a paraxial region in the eighth lens element L8; the object-side surface S13 of the eighth lens element L8 is convex near the circumference, and the image-side surface S14 is concave near the circumference.

Other structures of the second embodiment are the same as those of the first embodiment, and reference may be made thereto.

Tables 2a (1) -2 a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are all millimeters (mm), and the positive and negative values of the thickness value represent directions only.

TABLE 2a (1)

TABLE 2a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	9.6326	1.9173	5.6317	13.51	2.91	25.37	33.20
Position of middle focus	5.7509	5.6390	4.4897	17.82	3.45	19.13	31.90
								Position of long focus	0.1000	13.3843	2.8640	30.00	4.89	11.42	32.37

Wherein the values of the parameters in Table 2a (2) are the same as those of the first embodiment.

Table 2b gives the coefficients of high order terms that can be used for each aspherical mirror in the second embodiment, wherein each aspherical mirror type can be defined by the formula given in the first embodiment.

TABLE 2b

Fig. 2a shows a schematic structural view of the optical system of the second embodiment at the short focal end. Fig. 2b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment at the short focal end. As can be seen from fig. 2b, the optical system according to the second embodiment can achieve good imaging quality.

Fig. 2c shows a schematic configuration of the optical system of the second embodiment at the mid-focal end. Fig. 2d shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment at the mid-focal end. As can be seen from fig. 2d, the optical system according to the second embodiment can achieve good imaging quality.

Fig. 2e shows a schematic configuration of the optical system of the second embodiment at the tele end. Fig. 2f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the second embodiment at the tele end. As can be seen from fig. 2f, the optical system according to the second embodiment can achieve good imaging quality.

Third embodiment

Referring to fig. 3a to fig. 3f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

The sixth lens element L6 with negative refractive power has a concave object-side surface S9 and a concave image-side surface S10 at a paraxial region; the object-side surface S9 of the sixth lens element L6 is convex near the circumference, and the image-side surface S10 is concave near the circumference.

Other structures of the third embodiment are the same as those of the first embodiment, and reference may be made thereto.

Tables 3a (1) to 3a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are millimeters (mm), and the positive and negative of the thickness value represent directions only.

TABLE 3a (1)

TABLE 3a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	10.3179	0.9641	5.5421	12.51	2.77	27.54	33.20
Position of middle focus	6.1787	4.9911	4.3433	17.00	3.32	20.13	31.89
								Position of long focus	0.0938	13.1015	2.9798	30.00	4.84	11.45	32.55

Wherein the values of the parameters in Table 3a (2) are the same as those of the first embodiment.

Table 3b gives the coefficients of high-order terms that can be used for each aspherical mirror surface in the third embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 3b

Fig. 3a shows a schematic structure diagram of the optical system of the third embodiment at the short focal end. Fig. 3b shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment at the short focal end. As can be seen from fig. 3b, the optical system according to the third embodiment can achieve good imaging quality.

Fig. 3c shows a schematic configuration of the optical system of the third embodiment at the mid-focal end. Fig. 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. As can be seen from fig. 3d, the optical system according to the third embodiment can achieve good imaging quality.

Fig. 3e shows a schematic configuration of the optical system of the third embodiment at the tele end. Fig. 3f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the third embodiment at the tele end. As can be seen from fig. 3f, the optical system according to the third embodiment can achieve good imaging quality.

Fourth embodiment

Referring to fig. 4a to 4f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

The seventh lens element L7 with negative refractive power has a convex object-side surface S11 at a paraxial region and a concave image-side surface S12 at a paraxial region of the seventh lens element L7; the object-side surface S11 of the seventh lens element L7 is convex near the circumference, and the image-side surface S12 is concave near the circumference.

The eighth lens element L8 with positive refractive power has a concave object-side surface S13 and a convex image-side surface S14 at a paraxial region of the eighth lens element L8; the object-side surface S13 of the eighth lens element L8 is convex near the circumference, and the image-side surface S14 is concave near the circumference.

Other structures of the fourth embodiment are the same as those of the first embodiment, and reference may be made thereto.

Tables 4a (1) -4 a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are all millimeters (mm), and the positive and negative values of the thickness value represent directions only.

TABLE 4a (1)

TABLE 4a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	8.4385	0.9456	5.9131	13.87	2.85	24.61	30.40
Position of middle focus	5.4981	3.2466	5.4528	16.99	3.22	20.03	29.30
								Position of long focus	0.0800	12.7536	2.4637	30.49	4.85	11.24	30.40

Wherein, the values of the parameters in Table 4a (2) are the same as those of the first embodiment.

Table 4b gives the coefficients of high-order terms that can be used for each aspherical mirror surface in the fourth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 4b

Fig. 4a shows a schematic structural view of the optical system of the fourth embodiment at the short focal end. Fig. 4b shows a longitudinal spherical aberration curve, an astigmatism curve and a distortion curve of the optical system of the fourth embodiment at the short focal end. As can be seen from fig. 4b, the optical system according to the fourth embodiment can achieve good imaging quality.

Fig. 4c shows a schematic structural view of the optical system of the fourth embodiment at the mid-focal end. Fig. 4d shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment at the mid-focal end. As can be seen from fig. 4d, the optical system according to the fourth embodiment can achieve good imaging quality.

Fig. 4e shows a schematic configuration of the optical system of the fourth embodiment at the tele end. Fig. 4f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fourth embodiment at the tele end. As can be seen from fig. 4f, the optical system according to the fourth embodiment can achieve good imaging quality.

Fifth embodiment

Referring to fig. 5a to 5f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

The seventh lens element L7 with negative refractive power has a concave object-side surface S11 and a concave image-side surface S12 at paraxial region of the seventh lens element L7; the object-side surface S11 of the seventh lens element L7 is convex near the circumference, and the image-side surface S12 is concave near the circumference.

The eighth lens element L8 with positive refractive power has a concave object-side surface S13 and a convex image-side surface S14 at a paraxial region of the eighth lens element L8; the object-side surface S13 and the image-side surface S14 of the eighth lens element L8 are convex in the near-circumference direction.

The other structure of the fifth embodiment is the same as that of the first embodiment, and reference may be made thereto.

Tables 5a (1) -5 a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are all millimeters (mm), and the positive and negative values of the thickness value represent directions only.

TABLE 5a (1)

TABLE 5a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	9.8696	2.2813	5.1712	13.87	2.99	24.63	33.50
Position of middle focus	6.3765	5.1016	4.5441	17.55	3.44	19.42	32.20
								Position of long focus	0.2054	13.4899	3.4080	31.01	5.00	11.09	33.28

Wherein, the values of the parameters in Table 5a (2) are the same as those of the first embodiment.

Table 5b shows the high-order term coefficients that can be used for each aspherical mirror surface in the fifth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 5b

Fig. 5a shows a schematic structural view of the optical system of the fifth embodiment at the short focal end. Fig. 5b shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the fifth embodiment at the short focal end. As can be seen from fig. 5b, the optical system according to the fifth embodiment can achieve good image quality.

Fig. 5c shows a schematic configuration of the optical system of the fifth embodiment at the mid-focal end. Fig. 5d shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment at the mid-focal end. As can be seen from fig. 5d, the optical system according to the fifth embodiment can achieve good image quality.

Fig. 5e shows a schematic configuration of the optical system of the fifth embodiment at the tele end. Fig. 5f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the fifth embodiment at the tele end. As can be seen from fig. 5f, the optical system according to the fifth embodiment can achieve good imaging quality.

Sixth embodiment

Referring to fig. 6a to 6f, the optical system of the present embodiment, in order from an object side to an image side along an optical axis direction, includes:

Other structures of the sixth embodiment are the same as those of the first embodiment, and reference may be made thereto.

Tables 6a (1) -6 a (2) show tables of characteristics of the optical system of the present embodiment in which the focal length, the material refractive index, and the abbe number are all obtained from visible light having a reference wavelength of 587.6nm, the units of the Y radius, the thickness, and the effective focal length are all millimeters (mm), and the positive and negative values of the thickness value represent directions only.

TABLE 6a (1)

TABLE 6a (2)

Variable distance	D1	D2	D3	EFL(mm)	FNO	FOV(°)	TTL(mm)
								Short focal length position	9.3622	1.1774	6.1297	14.51	3.11	23.59	33.50
Position of middle focus	5.6181	5.2911	4.6349	19.18	3.70	17.78	32.37
								Position of long focus	0.0800	13.9728	2.6165	32.98	5.33	10.39	33.50

Wherein, the values of the parameters in Table 6a (2) are the same as those of the first embodiment.

Table 6b shows the high-order term coefficients that can be used for each aspherical mirror surface in the sixth embodiment, wherein each aspherical mirror surface type can be defined by the formula given in the first embodiment.

TABLE 6b

Fig. 6a shows a schematic structural view of the optical system of the sixth embodiment at the short focal end. Fig. 6b shows a longitudinal spherical aberration curve, an astigmatism curve, and a distortion curve of the optical system of the sixth embodiment at the short focal end. As can be seen from fig. 6b, the optical system according to the sixth embodiment can achieve good image quality.

Fig. 6c shows a schematic structural view of the optical system of the sixth embodiment at the mid-focal end. Fig. 6d shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the sixth embodiment at the mid-focal end. As can be seen from fig. 6d, the optical system according to the sixth embodiment can achieve good image quality.

Fig. 6e shows a schematic configuration of the optical system of the sixth embodiment at the tele end. Fig. 6f shows the longitudinal spherical aberration curve, astigmatism curve and distortion curve of the optical system of the sixth embodiment at the tele end. As can be seen from fig. 6f, the optical system according to the sixth embodiment can achieve good imaging quality.

Table 7 shows values of Fc/Fd, focc/ImgH, D2c/D2D, et12/ct12, fg3/g3, Fc/(f3+ fjh2), | R71|/R82, f8/ct8 in the optical systems of the first to sixth embodiments.

TABLE 7

As can be seen from table 7, the optical systems of the first to sixth embodiments all satisfy the following conditional expressions: Fc/Fd is more than or equal to 2.2, FOVc/ImgH is less than 3.9, 5.5 is less than D2c/D2D is less than 14, 2.5 is less than et12/ct12 is less than 7.5, 4 is less than fg3/g3 is less than 7.5, 1 is less than Fc/(f3+ fjh2) is less than 1.3, 1.2 is less than R71/R82 is less than 5.2, and 5 is less than f8/ct8 is less than 50.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. An optical system comprising, in order from an object side to an image side along an optical axis:

the right-angle prism comprises a light incident surface, a reflecting surface and a light emitting surface, the light incident surface is vertically connected with the light emitting surface, the reflecting surface is connected with the light incident surface and the light emitting surface, and light rays vertically enter the light incident surface and are emitted from the light emitting surface after being totally reflected by the reflecting surface;

the first lens group is opposite to the light emergent surface, has negative refractive power and comprises a first lens and a second lens which are sequentially arranged along the optical axis;

the second lens group has positive refractive power and comprises a third lens, a fourth lens and a fifth lens which are sequentially arranged along the optical axis;

the third lens group has positive refractive power and comprises a sixth lens, a seventh lens and an eighth lens which are sequentially arranged along the optical axis;

the first lens to the eighth lens include at least one aspherical plastic lens.

2. The optical system of claim 1 wherein the optical system is a zoom optical system having a long focal end and a short focal end.

3. The optical system according to claim 2, wherein the optical system satisfies the conditional expression:

Fc/Fd≥2.2；

and Fc is the effective focal length of the optical system at the long focal end, and Fd is the effective focal length of the optical system at the short focal end.

4. The optical system according to claim 2, wherein the optical system satisfies the conditional expression:

FOVc/ImgH<3.9；

and the FOVc is the maximum field angle of the optical system at the telephoto end, and the ImgH is half of the length of the diagonal of the effective photosensitive area on the imaging surface.

5. The optical system according to claim 2, wherein the optical system satisfies the conditional expression:

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 between the image-side surface of the fifth lens and the image-side surface of the sixth lens on the optical axis when the optical system is at the short focal end.

6. The optical system according to claim 1, wherein the optical system satisfies a conditional expression:

2.5<et12/ct12<7.5；

wherein et12 is a horizontal distance from the image-side surface of the second lens to the object-side surface of the third lens at the effective diameter, and ct12 is a distance from the image-side surface of the second lens to the object-side surface of the third lens on the optical axis.

7. The optical system according to claim 1, wherein the optical system satisfies a conditional expression:

4<fg3/g3<7.5；

wherein fg3 is an effective focal length of the third lens group, and g3 is a distance on an optical axis from an object-side surface of the sixth lens to an image-side surface of the eighth lens.

8. The optical system according to claim 2, wherein the optical system satisfies the conditional expression:

1<Fc/(f3+fjh2)<1.3；

wherein Fc is an effective focal length of the optical system at the tele end, and f3 is an 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 cemented to form a cemented lens.

9. The optical system according to claim 1, wherein the optical system satisfies a conditional expression:

1.2<|R71|/R82<5.2；

wherein R71 is a curvature radius value of the object-side surface of the seventh lens element on the optical axis, and R82 is a curvature radius of the image-side surface of the eighth lens element on the optical axis.

10. The optical system according to claim 1, wherein the optical system satisfies a conditional expression:

5<f8/ct8<50；

wherein f8 is an effective focal length of the eighth lens, and ct8 is a thickness of the eighth lens on an optical axis.

11. An image pickup module comprising a lens barrel, an electro-optic sensing element, and the optical system according to any one of claims 1 to 10, wherein the first to eighth lenses of the optical system are all mounted in the lens barrel, and the electro-optic sensing element is disposed on an image side of the optical system.

12. An electronic device comprising a housing and the camera module of claim 11, the camera module being disposed within the housing.