CN219143184U

CN219143184U - Imaging system

Info

Publication number: CN219143184U
Application number: CN202223288171.8U
Authority: CN
Inventors: 梁何; 梁伟朝; 应永茂
Original assignee: Sunny Optics Zhongshan Co Ltd
Current assignee: Sunny Optics Zhongshan Co Ltd
Priority date: 2022-12-08
Filing date: 2022-12-08
Publication date: 2023-06-06
Anticipated expiration: 2032-12-08

Abstract

The application discloses an imaging system, it includes in order from the object side to the image side along the optical axis: a first lens group having positive optical power and a second lens group having positive optical power. The first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The second lens group includes a tenth lens. The imaging system further includes a stop located between the fifth lens and the sixth lens; the position of the first lens group along the optical axis is adjustable.

Description

Imaging system

Technical Field

The present application relates to the field of optical elements, and in particular to an imaging system.

Background

Machine vision refers to the measurement and judgment of using a machine instead of the human eye. In machine vision applications, an imaging system (e.g., a lens) mounted on a machine captures a picture, an image capture device (e.g., an industrial camera) converts the picture captured by the imaging system into an image signal, and transmits the converted image signal, such as position, size, appearance, etc., to an image processing system. The image processing system outputs an acquisition result according to preset conditions so as to realize functions of automatic identification, judgment, measurement and the like.

It can be seen that the imaging system plays a critical role in machine vision applications, and its pixel, picture uniformity, distortion, brightness, and color rendition directly affect the quality of the machine vision system. However, the imaging system currently applied to the machine vision system generally has at least one of the problems of smaller imaging frame, larger distortion, uneven image definition, smaller range of working object distance, larger transmittance deviation, larger influence of temperature and the like. Therefore, the application field of the imaging system on the market at present is limited, and particularly, the imaging system cannot well perform the expected functions in some high-precision and high-tech fields.

Disclosure of Invention

An aspect of the present application provides an imaging system comprising, in order from an object side to an image side along an optical axis: a first lens group having positive optical power and a second lens group having positive optical power. The first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The second lens group includes a tenth lens. The imaging system further includes a stop located between the fifth lens and the sixth lens; the position of the first lens group along the optical axis is adjustable.

In one embodiment, the first lens, the fourth lens, the fifth lens, the sixth lens, and the eighth lens each have positive optical power; and the second lens, the third lens, the seventh lens and the ninth lens each have negative optical power.

In one embodiment, the tenth lens has positive optical power.

In one embodiment, the object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is a convex surface, and the image side surface is a concave surface; the object side surface of the third lens is a concave surface, and the image side surface is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface is a convex surface; the object side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a convex surface, and the image side surface is a convex surface; the object side surface of the seventh lens is a concave surface, and the image side surface is a concave surface; the object side surface of the eighth lens is a convex surface, and the image side surface is a convex surface; the object side surface of the ninth lens is a concave surface.

In one embodiment, the image side of the tenth lens is convex.

In one embodiment, the sixth lens and the seventh lens are cemented to form a first cemented lens; and the eighth lens and the ninth lens are cemented to form a second cemented lens.

In one embodiment, the third lens and the fourth lens are cemented to form a third cemented lens.

In one embodiment, the imaging system may satisfy: 0.65.ltoreq.f2/f1.ltoreq.1.86, where f1 is the effective focal length of the first lens group and f2 is the effective focal length of the second lens group.

In one embodiment, the imaging system may satisfy: 1.30.ltoreq.f1/f.ltoreq.1.89, where f1 is the effective focal length of the first lens group, and f is the total effective focal length when the imaging system is in the intermediate state.

In one embodiment, the imaging system may satisfy: f is more than or equal to 0.93 ₁₂ /f ₁₃ Less than or equal to 1.81, wherein f ₁₂ Is the effective focal length of the second lens, f ₁₃ Is the effective focal length of the third lens.

In one embodiment, at least one of the lenses having positive optical power of the first and second cemented lenses may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of at least one lens ₊ Is the refractive index of at least one lens.

In one embodiment, at least one lens of the first, second and third cemented lenses having positive optical power may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is at leastAbbe number, nd, of one lens ₊ Is the refractive index of at least one lens.

In one embodiment, the imaging system may satisfy: nd of 1.62 ∈nd _L2 Vd is not less than 1.92 and not less than 36.4 _L2 Less than or equal to 65.0, wherein Nd _L2 Is the refractive index of the second lens Vd _L2 Is the abbe number of the second lens.

In one embodiment, the imaging system may satisfy: -0.76 +.f9/f +.0.37, where f9 is the effective focal length of the ninth lens and f is the total effective focal length when the imaging system is in the intermediate state.

In one embodiment, the imaging system may satisfy: y is more than or equal to 0.33 and less than or equal to 0.38, wherein Y is the image height corresponding to the maximum field angle when the imaging system is in the intermediate state, and TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the imaging system on the optical axis when the imaging system is in the intermediate state.

In the exemplary embodiment of the application, the imaging system provided by the application has the beneficial effects of at least one of large target surface, low distortion, uniform image quality, wide working distance range, good temperature performance and the like by reasonably setting the lens compositions of the first lens group and the second lens group, the focal power of each lens group and each lens, the position of the first lens group, main technical parameters and the like.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings, in which:

FIG. 1 is a schematic view of the imaging system according to embodiment 1 of the present application in an intermediate state during a transition from an initial state to a final state;

FIGS. 2A to 2C show a Modulation Transfer Function (MTF) curve, an on-axis chromatic aberration curve, a field curvature curve, and a distortion curve, respectively, of the imaging system of embodiment 1 in an intermediate state;

FIG. 3 is a schematic view of the structure of the imaging system according to embodiment 2 of the present application in an intermediate state in the process of switching from an initial state to a final state;

fig. 4A to 4C show a Modulation Transfer Function (MTF) curve, an on-axis chromatic aberration curve, a field curvature curve, and a distortion curve, respectively, when the imaging system of embodiment 2 is in an intermediate state;

FIG. 5 is a schematic view of the structure of the imaging system according to embodiment 3 of the present application in an intermediate state in the process of switching from the initial state to the final state;

fig. 6A to 6C show a Modulation Transfer Function (MTF) curve, an on-axis chromatic aberration curve, a field curvature curve, and a distortion curve, respectively, when the imaging system of embodiment 3 is in an intermediate state;

FIG. 7 is a schematic view of the structure of the imaging system according to embodiment 4 of the present application in an intermediate state in the process of switching from the initial state to the final state; and

Fig. 8A to 8C show a Modulation Transfer Function (MTF) curve, an on-axis chromatic aberration curve, a field curvature curve, and a distortion curve, respectively, when the imaging system of embodiment 4 is in an intermediate state.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed description are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. In particular, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, then the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side of the lens.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the present application, use of "may" means "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The features, principles, and other aspects of the present application are described in detail below.

An imaging system according to an exemplary embodiment of the present application may include two lens groups having optical power, a first lens group and a second lens group, respectively. The two lens groups are sequentially arranged from an object side to an image side along an optical axis. The first lens group may include nine lenses having optical power, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, respectively. The nine lenses are arranged in order from the object side to the image side along the optical axis. The second lens group may include a lens having optical power, such as a tenth lens.

In an exemplary embodiment, the position of the first lens group along the optical axis is adjustable to provide continuous zooming of the imaging system. Specifically, switching the imaging system from the initial state to the final state or from the final state to the initial state is achieved by changing the position of the first lens group on the optical axis to cause the imaging system to perform continuous zooming. By adjusting the interval distance between the ninth lens and the tenth lens on the optical axis, the focal length of the imaging system is adjusted, so that the imaging system has a better imaging position, continuous zooming of the imaging system is realized, and clear imaging can be realized when the imaging system is at different distances from the shot object.

In the present application, the initial state of the imaging system may be a state when the imaging system is closest to the subject (compared to when it is farthest from the subject). The final state of the imaging system may be a state when the imaging system is farthest from the subject (as compared to when it is closest to the subject). The state of the imaging system between the initial state and the final state is then the intermediate state of the imaging system. Illustratively, the initial state of the imaging system may be a state when the imaging system is 700mm from the subject, the intermediate state of the imaging system may be a state when the imaging system is 1000mm from the subject, and the final state of the imaging system may be a state when the imaging system is infinity from the subject.

In an exemplary embodiment, the first lens group may have positive optical power; the second lens group may have positive optical power. Illustratively, the first lens may have a positive optical power; the second lens may have negative optical power; the third lens may have negative optical power; the fourth lens may have positive optical power; the fifth lens may have positive optical power; the sixth lens may have positive optical power; the seventh lens may have negative optical power; the eighth lens may have positive optical power; the ninth lens may have negative optical power; and the tenth lens may have positive optical power. The optical power of each lens is reasonably set, so that the imaging system can have better optical aberration and distortion correcting capability of the system when the imaging system is at different distances from the shot object, the effect that incident light rays can sequentially pass through each surface of each lens at a smaller angle, the tolerance sensitivity of the system is reduced, the uniformity of a picture is improved and the like is facilitated. By means of the imaging system, the first lens is provided with positive focal power, the second lens is provided with negative focal power, the incident angle of light can be effectively controlled, aberration and tolerance of the system are reduced, and imaging quality of the imaging system is improved.

In an exemplary embodiment, the object-side surface of the first lens may be convex, and the image-side surface may be concave; the object side surface of the second lens element may be convex, and the image side surface thereof may be concave; the object side surface of the third lens element may be concave, and the image side surface thereof may be concave; the fourth lens element may have a convex object-side surface and a convex image-side surface; the object side surface of the fifth lens element may be convex, and the image side surface thereof may be convex or concave; the object side surface of the sixth lens element may be convex, and the image side surface thereof may be convex; the object side surface of the seventh lens element may be concave, and the image side surface thereof may be concave; the object side surface of the eighth lens element may be convex, and the image side surface thereof may be convex; the object side surface of the ninth lens element can be concave, and the image side surface can be convex or concave; and the object-side surface of the tenth lens element may be convex or concave, and the image-side surface may be convex. The optical power and the surface type characteristics of each lens are reasonably arranged, so that the distortion and the aberration of the system can be corrected, and the imaging quality of the system can be improved.

In an exemplary embodiment, at least two lenses of the first lens group may be cemented to form a cemented lens. The first lens group may include at least two cemented lenses. In an exemplary embodiment, the first lens group may include a first cemented lens formed by a sixth lens cemented with a seventh lens, and a second cemented lens formed by an eighth lens cemented with a ninth lens. In another exemplary embodiment, the first lens group may include a first cemented lens formed by a sixth lens cemented with a seventh lens, a second cemented lens formed by an eighth lens cemented with a ninth lens, and a third cemented lens formed by a third lens cemented with a fourth lens. In the application, by arranging the cemented lens, various aberrations of an imaging system are corrected, the matching sensitivity of each lens is reduced, and the resolution is improved. By way of example, the fifth lens and the first cemented lens cooperate to form a gaussian structure, so that the incident angle of light can be effectively reduced, the sensitivity of tolerance can be reduced, and distortion can be well corrected.

In an exemplary embodiment, an imaging system according to the present application may satisfy: 0.65.ltoreq.f2/f1.ltoreq.1.86, where f1 is the effective focal length of the first lens group and f2 is the effective focal length of the second lens group. According to the imaging system, f2 and f1 are reasonably arranged, the focal length of the imaging system can be adjusted at different distances from the shot object, so that the imaging system can clearly image at different distances from the shot object, the field curvature of the system is reduced, the imaging quality is ensured, and the tolerance sensitivity between the first lens group and the second lens group is balanced.

In an exemplary embodiment, an imaging system according to the present application may satisfy: 1.30.ltoreq.f1/f.ltoreq.1.89, where f1 is the effective focal length of the first lens group, and f is the total effective focal length when the imaging system is in the intermediate state. According to the imaging system, f and f1 are reasonably arranged, the focal length of the imaging system can be adjusted at different distances from the shot object, so that the imaging system can clearly image at different distances from the shot object, the field curvature of the system is reduced, the imaging quality is ensured, and the tolerance sensitivity between the first lens group and the second lens group is balanced.

In an exemplary embodiment, an imaging system according to the present application may satisfy: f is more than or equal to 0.93 ₁₂ /f ₁₃ Less than or equal to 1.81, wherein f ₁₂ Is the effective focal length of the second lens, f ₁₃ Is the effective focal length of the third lens. The application reasonably arranges f ₁₂ And f ₁₃ The deflection angle of the incident light is reduced, and the tolerance sensitivity is reduced.

In an exemplary embodiment, at least one lens (e.g., a sixth lens and an eighth lens) having positive power among the first cemented lens and the second cemented lens may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of at least one lens ₊ Is the refractive index of at least one lens. For example, the eighth lens may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of the eighth lens ₊ Is the refractive index of the eighth lens. According to the imaging system, the refractive index and the Abbe number of at least one lens in the sixth lens and the eighth lens are reasonably set to meet the range, so that the chromatic aberration of the imaging system can be effectively corrected, the imaging quality of the imaging system is improved, meanwhile, the temperature correction capability of the system can be improved, and the imaging system can clearly image in a larger temperature range.

In an exemplary embodiment, at least one lens (e.g., fourth, sixth, and eighth lenses) having positive optical power among the first, second, and third cemented lenses may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of at least one lens ₊ Is the refractive index of at least one lens. For example, the eighth lens may satisfy: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of the eighth lens ₊ Is the refractive index of the eighth lens. According to the imaging system, the refractive index and the Abbe number of at least one lens among the fourth lens, the sixth lens and the eighth lens are reasonably set to meet the range, so that the chromatic aberration of the imaging system can be effectively corrected, the imaging quality of the imaging system is improved, meanwhile, the temperature correction capability of the system can be improved, and the imaging system can clearly image in a larger temperature range.

In an exemplary embodiment, an imaging system according to the present application may satisfy: nd of 1.62 ∈nd _L2 Vd is not less than 1.92 and not less than 36.4 _L2 Less than or equal to 65.0, wherein Nd _L2 Is the refractive index of the second lens Vd _L2 Is the firstAbbe number of the two lenses. According to the imaging system, the refractive index and the Abbe number of the second lens are reasonably set, so that the on-axis aberration of the imaging system can be better compensated, and the imaging quality can be further improved.

In an exemplary embodiment, an imaging system according to the present application may satisfy: -0.76 +.f9/f +.0.37, where f9 is the effective focal length of the ninth lens and f is the total effective focal length when the imaging system is in the intermediate state. Through reasonable setting of f9 and f, the imaging system has the characteristics of larger back focus, larger target surface and the like.

In an exemplary embodiment, an imaging system according to the present application may satisfy: y is more than or equal to 0.33 and less than or equal to 0.38, wherein Y is the image height corresponding to the maximum field angle when the imaging system is in the intermediate state, and TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the imaging system on the optical axis when the imaging system is in the intermediate state. The imaging quality of a large target surface is facilitated by reasonably setting Y and TTL. Otherwise, if Y/TTL is too large, it is difficult to ensure the image quality of the large target surface; if Y/TTL is too small, the imaging image plane is smaller.

In an exemplary embodiment, the imaging system according to the present application further comprises a stop arranged between the fifth lens and the sixth lens. Optionally, the image system may further include a filter for correcting color deviation and/or a protective glass for protecting the photosensitive element located on the imaging surface. According to the imaging system, the distance between the ninth lens and the tenth lens on the optical axis can be adjusted, so that the focal length of the imaging system can be adjusted, the imaging system has a better imaging position, continuous zooming of the imaging system is realized, and imaging can be clearly performed when the imaging system is at different distances from a shot object. The application provides an imaging system with the characteristics of continuous zooming, smooth transition of pictures in the zooming process, large target surface, small distortion, uniform image quality, wide working object distance range, good temperature performance, high imaging quality and the like. For example, the imaging system provided by the application can clearly image at 700 mm-infinity distance from the shot object and can clearly image at-20-70 ℃ temperature range. The imaging system according to the above-described embodiments of the present application may employ multiple lenses, such as the ten lenses described above. By reasonably distributing the focal power, the surface shape, the center thickness of each lens, the axial spacing between each lens and the like of each lens, incident light rays can be effectively converged, the optical total length of the imaging lens is reduced, and the processability of the imaging lens is improved, so that the imaging system is more beneficial to production and processing.

However, those skilled in the art will appreciate that the number of lenses making up the imaging system can be varied to achieve the various results and advantages described in the specification without departing from the technical solutions claimed herein. For example, although the description is given by taking ten lenses as an example in the embodiment, the imaging system is not limited to include ten lenses. The imaging system may also include other numbers of lenses, if desired.

Specific examples of imaging systems applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

Example 1

An imaging system according to embodiment 1 of the present application is described below with reference to fig. 1 to 2C. Fig. 1 is a schematic configuration diagram of an imaging system according to embodiment 1 of the present application in an intermediate state (e.g., 1000mm from a subject) in the process of switching from an initial state to a final state.

As shown in fig. 1, the imaging system sequentially includes, from an object side to an image side: the first lens group G1 (first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, stop STO, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9), the second lens group G2 (tenth lens L10), optical filter and/or cover glass CG, and an imaging plane.

The first lens element L1 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The second lens element L2 has negative refractive power, and has a convex object-side surface and a concave image-side surface. The third lens element L3 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The fourth lens element L4 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The fifth lens element L5 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens element L6 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The seventh lens element L7 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The eighth lens element L8 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The ninth lens element L9 has negative refractive power, and has a concave object-side surface and a convex image-side surface. The tenth lens element L10 has positive refractive power, and has a concave object-side surface and a convex image-side surface. The sixth lens L6 and the seventh lens L7 may be cemented to form a first cemented lens. The eighth lens L8 and the ninth lens L9 may be cemented to form a second cemented lens. Light from the object sequentially passes through the surfaces (i.e. sequentially passes through the object side of the first lens L1 to the image side of the filter and/or the cover glass CG) and is finally imaged on an imaging plane, where an image sensing chip IMA may be arranged. The filter and/or cover glass may be used to correct color deviations and/or to protect the image sensing chip IMA located on the imaging plane.

Table 1 shows the basic parameter table of the imaging system of example 1, in which the radius of curvature and the thickness/distance are each in millimeters (mm).

TABLE 1

In this example, the surface 11 is the object side of the first lens and the surface 12 is the image side of the first lens. The surface 21 is the object side of the second lens and the surface 22 is the image side of the second lens. The surface 31 is the object side of the third lens element and the surface 32 is the image side of the third lens element. The surface 41 is the object side of the fourth lens element and the surface 42 is the image side of the fourth lens element. The surface 51 is the object side of the fifth lens element, and the surface 52 is the image side of the fifth lens element. The surface 61 is the object side of the sixth lens and the surface 62 is the image side of the sixth lens. The surface 71 is the object side of the seventh lens and the surface 72 is the image side of the seventh lens. The surface 81 is the object side of the eighth lens element and the surface 82 is the image side of the eighth lens element. Surface 91 is the object side of the ninth lens and surface 92 is the image side of the ninth lens. Surface 101 is the object side of the tenth lens and surface 102 is the image side of the tenth lens. Surface 111 is the object side of the filter and surface 112 is the image side of the filter.

In this example, by changing the position of the first lens group on the optical axis, the total effective focal length of the imaging system can be changed with a change in distance from the subject, thereby realizing continuous zooming of the imaging system. In other words, the imaging system is sequentially switched from the initial state to the intermediate state, the final state, or from the final state to the intermediate state, the initial state by changing the separation distance D of the first lens group and the second lens group on the optical axis (i.e., the air separation of the ninth lens L9 and the tenth lens L10 on the optical axis). The total effective focal length f, the maximum half field angle HFOV, and the aperture value Fno of the imaging system change as the imaging system sequentially switches from an initial state to an intermediate state, a final state, or from the final state to the intermediate state, the initial state. In this example, the initial state of the imaging system may be a state of the imaging system at 700mm from the subject, the intermediate state of the imaging system may be a state of the imaging system at 1000mm from the subject, and the final state of the imaging system may be a state of the imaging system at infinity from the subject.

Table 2 shows specific parameter values of the total effective focal length f of the imaging system, the maximum half field angle HFOV of the imaging system, the aperture value Fno of the imaging system, and the air interval D on the optical axis of the ninth and tenth lenses when the imaging system of embodiment 1 is in the intermediate state, where f and D are each in millimeters (mm), and HFOV is in degrees (°).

Status/parameters	f	HFOV	Fno	D
					Intermediate state	34.77	31.39	4.06	15.05

TABLE 2

In this example, when the imaging system is in the initial state, the air interval D of the ninth lens and the tenth lens on the optical axis is 16.21mm; when the imaging system is in the final state, the air space D on the optical axis of the ninth and tenth lenses is 12.34mm.

Fig. 2A shows a Modulation Transfer Function (MTF) curve of the imaging system in the range of 0.449 μm to 0.680 μm band, which represents the meridional field of view and the pixel size over the sagittal field of view at different frequencies, when the imaging system of embodiment 1 is in an intermediate state (i.e., 1000mm from the subject). Fig. 2B shows an on-axis chromatic aberration curve of the imaging system in the range of 0.449 μm to 0.680 μm when the imaging system of embodiment 1 is in an intermediate state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 2C shows a field curvature curve and a distortion curve of the imaging system in a band range of 0.449 μm to 0.680 μm when the imaging system of embodiment 1 is in an intermediate state, wherein the field curvature curve represents meridional image plane curvature and sagittal image plane curvature, and the distortion curve represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 2A to 2C, the imaging system according to embodiment 1 can achieve good imaging quality in the intermediate state.

Example 1 illustrates only the MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the intermediate state, to avoid lengthy unrecited MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the initial state and the final state. It should be understood that the imaging system provided in embodiment 1 provided in the present application can achieve good imaging quality in each state.

Example 2

An imaging system according to embodiment 2 of the present application is described below with reference to fig. 3 to 4C. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 3 shows a schematic configuration diagram of an intermediate state (e.g., 1000mm from a subject) in the process of switching from an initial state to a final state of the imaging system according to embodiment 2 of the present application.

As shown in fig. 3, the imaging system sequentially includes, from an object side to an image side: the first lens group G1 (first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, stop STO, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9), the second lens group G2 (tenth lens L10), optical filter and/or cover glass CG, and an imaging plane.

The first lens element L1 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The second lens element L2 has negative refractive power, and has a convex object-side surface and a concave image-side surface. The third lens element L3 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The fourth lens element L4 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The fifth lens element L5 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The sixth lens element L6 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The seventh lens element L7 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The eighth lens element L8 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The ninth lens element L9 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The tenth lens element L10 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens L6 and the seventh lens L7 may be cemented to form a first cemented lens. The eighth lens L8 and the ninth lens L9 may be cemented to form a second cemented lens. The third lens L3 and the fourth lens L4 may be cemented to form a third cemented lens. Light from the object sequentially passes through the surfaces (i.e. sequentially passes through the object side of the first lens L1 to the image side of the filter and/or the cover glass CG) and is finally imaged on an imaging plane, where an image sensing chip IMA may be arranged. The filter and/or cover glass may be used to correct color deviations and/or to protect the image sensing chip IMA located on the imaging plane.

Table 3 shows a basic parameter table of the imaging system of example 2, in which the radius of curvature and the thickness/distance are each in millimeters (mm).

TABLE 3 Table 3

Table 4 shows specific parameter values of the total effective focal length f of the imaging system, the maximum half field angle HFOV of the imaging system, the aperture value Fno of the imaging system, and the air interval D on the optical axis of the ninth and tenth lenses when the imaging system of embodiment 2 is in the intermediate state, where f and D are each in millimeters (mm), and HFOV is in degrees (°).

Status/parameters	f	HFOV	Fno	D
					Intermediate state	34.62	31.53	4.07	13.02

TABLE 4 Table 4

In this example, when the imaging system is in the initial state, the air interval D of the ninth lens and the tenth lens on the optical axis is 14.77mm; when the imaging system is in the final state, the air space D on the optical axis of the ninth lens and the tenth lens is 8.94mm.

Fig. 4A shows a Modulation Transfer Function (MTF) curve of the imaging system in a band range of 0.449 μm to 0.680 μm, which represents the pixel sizes over the meridional field of view and the sagittal field of view at different frequencies, when the imaging system of embodiment 2 is in an intermediate state (i.e., 1000mm from the subject). Fig. 4B shows an on-axis chromatic aberration curve of the imaging system in the range of 0.449 μm to 0.680 μm when the imaging system of embodiment 2 is in an intermediate state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 4C shows a field curvature curve and a distortion curve of the imaging system in a band range of 0.449 μm to 0.680 μm when the imaging system of embodiment 2 is in an intermediate state, wherein the field curvature curve represents meridional image plane curvature and sagittal image plane curvature, and the distortion curve represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 4A to 4C, the imaging system according to embodiment 2 can achieve good imaging quality in the intermediate state.

Example 2 illustrates only the MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the intermediate state, to avoid lengthy unrecited MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the initial state and the final state. It should be understood that the imaging system provided in embodiment 1 provided in the present application can achieve good imaging quality in each state.

Example 3

An imaging system according to embodiment 3 of the present application is described below with reference to fig. 5 to 6C. Fig. 5 is a schematic structural view of an imaging system according to embodiment 3 of the present application in an intermediate state (e.g., 1000mm from a subject) in the process of switching from an initial state to a final state.

As shown in fig. 5, the imaging system sequentially includes, from an object side to an image side: the first lens group G1 (first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, stop STO, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9), the second lens group G2 (tenth lens L10), optical filter and/or cover glass CG, and an imaging plane.

The first lens element L1 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The second lens element L2 has negative refractive power, and has a convex object-side surface and a concave image-side surface. The third lens element L3 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The fourth lens element L4 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The fifth lens element L5 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The sixth lens element L6 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The seventh lens element L7 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The eighth lens element L8 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The ninth lens element L9 has negative refractive power, and has a concave object-side surface and a convex image-side surface. The tenth lens element L10 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The sixth lens L6 and the seventh lens L7 may be cemented to form a first cemented lens. The eighth lens L8 and the ninth lens L9 may be cemented to form a second cemented lens. The third lens L3 and the fourth lens L4 may be cemented to form a third cemented lens. Light from the object sequentially passes through the surfaces (i.e. sequentially passes through the object side of the first lens L1 to the image side of the filter and/or the cover glass CG) and is finally imaged on an imaging plane, where an image sensing chip IMA may be arranged. The filter and/or cover glass may be used to correct color deviations and/or to protect the image sensing chip IMA located on the imaging plane.

Table 5 shows a basic parameter table of the imaging system of example 3, in which the radius of curvature and the thickness/distance are each in millimeters (mm).

TABLE 5

Table 6 shows specific parameter values of the total effective focal length f of the imaging system, the maximum half field angle HFOV of the imaging system, the aperture value Fno of the imaging system, and the air interval D on the optical axis of the ninth and tenth lenses when the imaging system of embodiment 3 is in the intermediate state, where f and D are each in millimeters (mm), and HFOV is in degrees (°).

Status/parameters	f	HFOV	Fno	D
					Intermediate state	34.68	31.46	4.06	12.49

TABLE 6

In this example, when the imaging system is in the initial state, the air interval D of the ninth lens and the tenth lens on the optical axis is 14.22mm; when the imaging system is in the final state, the air space D of the ninth lens and the tenth lens on the optical axis is 9.02mm.

Fig. 6A shows a Modulation Transfer Function (MTF) curve of the imaging system of example 3 in a band range of 0.449 μm to 0.680 μm, which represents the meridional field of view and the pixel size over the sagittal field of view at different frequencies, when the imaging system is in an intermediate state (i.e., 1000mm from the subject). Fig. 6B shows an on-axis chromatic aberration curve of the imaging system in the range of 0.449 μm to 0.680 μm when the imaging system of embodiment 3 is in an intermediate state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 6C shows a field curvature curve and a distortion curve of the imaging system in a band range of 0.449 μm to 0.680 μm when the imaging system of embodiment 3 is in an intermediate state, wherein the field curvature curve represents meridional image plane curvature and sagittal image plane curvature, and the distortion curve represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 6A to 6C, the imaging system according to embodiment 3 can achieve good imaging quality in the intermediate state.

Example 3 illustrates only the MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the intermediate state, to avoid lengthy unrecited MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the initial state and the final state. It should be understood that the imaging system provided in embodiment 1 provided in the present application can achieve good imaging quality in each state.

Example 4

An imaging system according to embodiment 4 of the present application is described below with reference to fig. 7 to 8C. Fig. 7 shows a schematic configuration diagram of an intermediate state (e.g., 1000mm from a subject) in the process of switching from an initial state to a final state of the imaging system according to embodiment 4 of the present application.

As shown in fig. 7, the imaging system sequentially includes, from an object side to an image side: the first lens group G1 (first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, stop STO, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9), the second lens group G2 (tenth lens L10), optical filter and/or cover glass CG, and an imaging plane.

The first lens element L1 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The second lens element L2 has negative refractive power, and has a convex object-side surface and a concave image-side surface. The third lens element L3 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The fourth lens element L4 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The fifth lens element L5 has positive refractive power, and has a convex object-side surface and a concave image-side surface. The sixth lens element L6 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The seventh lens element L7 has negative refractive power, and has a concave object-side surface and a concave image-side surface. The eighth lens element L8 has positive refractive power, and has a convex object-side surface and a convex image-side surface. The ninth lens element L9 has negative refractive power, and has a concave object-side surface and a convex image-side surface. The tenth lens element L10 has positive refractive power, and has a concave object-side surface and a convex image-side surface. The sixth lens L6 and the seventh lens L7 may be cemented to form a first cemented lens. The eighth lens L8 and the ninth lens L9 may be cemented to form a second cemented lens. The third lens L3 and the fourth lens L4 may be cemented to form a third cemented lens. Light from the object sequentially passes through the surfaces (i.e. sequentially passes through the object side of the first lens L1 to the image side of the filter and/or the cover glass CG) and is finally imaged on an imaging plane, where an image sensing chip IMA may be arranged. The filter and/or cover glass may be used to correct color deviations and/or to protect the image sensing chip IMA located on the imaging plane.

Table 7 shows a basic parameter table of the imaging system of example 4, in which the radius of curvature and the thickness/distance are each in millimeters (mm).

TABLE 7

Table 8 shows specific parameter values of the total effective focal length f of the imaging system, the maximum half field angle HFOV of the imaging system, the aperture value Fno of the imaging system, and the air space D on the optical axis of the ninth lens and the tenth lens in units of millimeters (mm) and HFOV in degrees (°) when the imaging system of example 4 is in the initial state, the intermediate state, and the final state.

Status/parameters	f	HFOV	Fno	D
					Intermediate state	34.76	31.37	4.06	15.17

TABLE 8

In this example, when the imaging system is in the initial state, the air interval D of the ninth lens and the tenth lens on the optical axis is 16.37mm; when the imaging system is in the final state, the air space D of the ninth and tenth lenses on the optical axis is 12.32mm.

Fig. 8A shows a Modulation Transfer Function (MTF) curve of the imaging system in the band range of 0.449 μm to 0.680 μm, which represents the pixel sizes over the meridional field of view and the sagittal field of view at different frequencies, when the imaging system of embodiment 4 is in an intermediate state (i.e., 1000mm from the subject). Fig. 8B shows an on-axis chromatic aberration curve of the imaging system in the range of 0.449 μm to 0.680 μm when the imaging system of embodiment 4 is in an intermediate state, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the lens. Fig. 8C shows a field curvature curve and a distortion curve of the imaging system in a band range of 0.449 μm to 0.680 μm when the imaging system of embodiment 4 is in an intermediate state, wherein the field curvature curve represents meridional image plane curvature and sagittal image plane curvature, and the distortion curve represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 8A to 8C, the imaging system according to embodiment 4 can achieve good imaging quality in the intermediate state.

Example 4 illustrates only the MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the intermediate state, to avoid lengthy unrecited MTF profile, on-axis color difference profile, field curvature profile, and distortion profile when the imaging system is in the initial state and the final state. It should be understood that the imaging system provided in embodiment 1 provided in the present application can achieve good imaging quality in each state.

In summary, examples 1 to 4 satisfy the relationships shown in table 9, respectively.

Condition/example	1	2	3	4
					f2/f1	1.455	0.851	0.985	1.302
f1/f	1.450	1.791	1.700	1.500
					f ₁₂ /f ₁₃	0.710	1.076	1.215	1.245
Y/TTL	0.339	0.360	0.369	0.366
					f9/f	-0.689	-0.442	-0.434	-0.547

TABLE 9

The present application also provides an imaging device, the electron-sensitive element of which may be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device may be a stand alone imaging device such as a machine vision system or may be an imaging module integrated on a mobile electronic device such as a machine vision system. The imaging device is equipped with the imaging system described above.

The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the invention referred to in this application is not limited to the specific combinations of features described above, but it is intended to cover other embodiments in which any combination of features described above or equivalents thereof is possible without departing from the spirit of the invention. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims

1. The imaging system is characterized by comprising, in order from an object side to an image side along an optical axis:

a first lens group having positive optical power, the first lens group including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens;

a second lens group having positive optical power, including a tenth lens;

the imaging system further includes a stop located between the fifth lens and the sixth lens; and

the position of the first lens group along the optical axis is adjustable.

2. The imaging system of claim 1, wherein the imaging system comprises a plurality of imaging devices,

the sixth lens and the seventh lens are glued to form a first glued lens; and

the eighth lens and the ninth lens are cemented to form a second cemented lens.

3. The imaging system of claim 2, wherein the third lens and the fourth lens are cemented to form a third cemented lens.

4. The imaging system of claim 1, wherein the imaging system satisfies: and f2/f1 is more than or equal to 0.65 and less than or equal to 1.86, wherein f1 is the effective focal length of the first lens group, and f2 is the effective focal length of the second lens group.

5. The imaging system of claim 1, wherein the imaging system satisfies: 1.30.ltoreq.f1/f.ltoreq.1.89, wherein f1 is an effective focal length of the first lens group, and f is a total effective focal length when the imaging system is in an intermediate state.

6. The imaging system of claim 1, wherein the imaging system satisfies: f is more than or equal to 0.93 ₁₂ /f ₁₃ Less than or equal to 1.81, wherein f ₁₂ Is the effective focal length, f, of the second lens ₁₃ Is the effective focal length of the third lens.

7. The imaging system of claim 2, wherein at least one of the lenses of the first cemented lens and the second cemented lens having positive optical power satisfies: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of the at least one lens ₊ Is the refractive index of the at least one lens.

8. The imaging system of claim 3, whereinIn that at least one lens of the lenses having positive optical power among the first cemented lens, the second cemented lens, and the third cemented lens satisfies: vd of 59.3 or less ₊ 86.1 and Nd 1.47 ₊ Not more than 1.65, wherein Vd ₊ Is the Abbe number, nd, of the at least one lens ₊ Is the refractive index of the at least one lens.

9. The imaging system of claim 1, wherein the imaging system satisfies: nd of 1.62 ∈nd _L2 Vd is not less than 1.92 and not less than 36.4 _L2 Less than or equal to 65.0, wherein Nd _L2 Is the refractive index, vd, of the second lens _L2 Is the abbe number of the second lens.

10. The imaging system of claim 1, wherein the imaging system satisfies: -0.76 +.f9/f +.0.37, where f9 is the effective focal length of the ninth lens and f is the total effective focal length of the imaging system in the intermediate state.

11. The imaging system of any of claims 1-10, wherein the imaging system satisfies: y is more than or equal to 0.33 and less than or equal to 0.38, wherein Y is the image height corresponding to the maximum field angle when the imaging system is in the middle state, and TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the imaging system on the optical axis when the imaging system is in the middle state.

12. The imaging system of any of claims 1-10, wherein,

the first lens, the fourth lens, the fifth lens, the sixth lens, and the eighth lens each have positive optical power; and

The second lens, the third lens, the seventh lens, and the ninth lens each have negative optical power.

13. The imaging system of any of claims 1-10, wherein the tenth lens has positive optical power.

14. The imaging system of any of claims 1-10, wherein,

the object side surface of the first lens is a convex surface, and the image side surface is a concave surface;

the object side surface of the second lens is a convex surface, and the image side surface is a concave surface;

the object side surface of the third lens is a concave surface, and the image side surface is a concave surface;

the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface;

the object side surface of the fifth lens is a convex surface;

the object side surface of the sixth lens is a convex surface, and the image side surface is a convex surface;

the object side surface of the seventh lens is a concave surface, and the image side surface is a concave surface;

the object side surface of the eighth lens is a convex surface, and the image side surface is a convex surface; and

the object side surface of the ninth lens is a concave surface.

15. The imaging system of any of claims 1-10, wherein an image side of the tenth lens is convex.