CN112788204B

CN112788204B - Lens group, camera module and imaging system

Info

Publication number: CN112788204B
Application number: CN201911086821.0A
Authority: CN
Inventors: 王一峰; 谢前森
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2022-07-22
Anticipated expiration: 2039-11-08
Also published as: CN112788204A

Abstract

The application discloses a lens group, a camera module and an imaging system. A lens group according to an exemplary embodiment is to be coupled with an image sensor, and light from the outside passing through the lens group forms an image on the image sensor, wherein the lens group includes a free-form lens having a non-rotationally symmetric mirror surface, so that the image formed on the image sensor has a first imaging area and a second imaging area having different zoom magnifications from each other. A camera module according to an exemplary embodiment includes a lens group as described above. The imaging system includes a camera module having a lens group and a display module.

Description

Lens group, camera module and imaging system

Technical Field

The present invention relates to the field of optical lenses, and more particularly, to a camera module suitable for a vehicle rearview mirror and a vehicle imaging system including the same.

Background

As the driving support technology has become mature, a vehicle driving support function for supporting parking or the like has become widespread. In order to acquire information on road conditions around a vehicle, pedestrians, and the like, it is necessary to capture image information of the ground and objects on the ground within a certain range using an optical lens such as a rearview mirror, a round-looking lens, and the like. In particular, the parking assist function requires a strong attention to the situation of a somewhat distant object or pedestrian in order to avoid an unexpected collision. Therefore, the image sharpness and the scaling of the corresponding imaged parts on the chip are important.

However, the conventional optical lens has a large-size and small-size characteristic when imaging. Whereas a vehicle rearview mirror is usually mounted obliquely downwards, fig. 1 schematically shows an application scenario of the vehicle rearview mirror. The application of a conventional optical lens to a rearview lens for a parking assist function causes a captured image to have such characteristics: the ground adjacent the vehicle is magnified and occupies a large portion of the area on the imaging surface, while objects or pedestrians at a greater distance are compressed. Such images are extremely disadvantageous for the driver to effectively recognize a somewhat distant object or pedestrian.

However, the mirror surface of the conventional optical lens has a rotationally symmetric structure, and the image height angle curve in the ideal state is as shown in fig. 2, and it can be seen that the image plane is symmetric. Further, fig. 3 schematically shows a schematic diagram of an ideal imaging region of a lens barrel to which a rotationally symmetric lens is applied. It is obvious that the lens barrel using the conventional optical lens has a symmetrical property in an image formed on an image forming surface, and thus does not have a capability of correcting the above-mentioned situation.

In view of the above, there is a need to develop a rear-view lens that can specifically enlarge or compress the field of view to improve the driver's effective recognition of a slightly distant object or pedestrian, thereby avoiding an unexpected collision during parking.

Disclosure of Invention

The technical solution provided by the present application at least partially solves the technical problems described above.

According to one aspect of the present application, there is provided an imaging system for vehicle assisted driving, the imaging system comprising a camera module having one or more lenses and a display module, wherein the camera module further comprises an image sensor for receiving light from outside through the one or more lenses, the light forming an image on the image sensor, the image sensor being configured to convert the image into an electrical signal, and wherein the display module receives the electrical signal from the image sensor and displays an image based on the electrical signal. Wherein the one or more lenses comprise a free-form lens having a non-rotationally symmetric mirror surface such that the image formed on the image sensor has a first imaging area and a second imaging area, the first imaging area and the second imaging area having different zoom magnifications from each other.

In one exemplary embodiment, the free-form surface lens is symmetrical in a first direction perpendicular to an optical axis thereof, and is asymmetrical in a second direction perpendicular to the optical axis and the first direction.

In one exemplary embodiment, the number of optical systems of the free-form-surface lens is selected such that an image in the first imaging region is enlarged and an image in the second imaging region is reduced.

In an exemplary embodiment, the first imaging region has an area larger than an area of the second imaging region.

In an exemplary embodiment, an area of the first imaging region is smaller than an area of the second imaging region.

In an exemplary embodiment, the area of the first imaging region is equal to the area of the second imaging region.

In an exemplary embodiment, the first imaging zone and the second imaging zone are distributed in a first direction perpendicular to an optical axis of the one or more lenses.

In one exemplary embodiment, the first imaging region includes a first magnification region and a second magnification region, and the second imaging region includes a first demagnification region, wherein the first magnification region, the first demagnification region and the second magnification region are sequentially arranged in a first direction perpendicular to an optical axis of the one or more lenses.

In an exemplary embodiment, the first imaging region includes a first zoom-in region, and the second imaging region includes a first zoom-out region and a second zoom-out region, wherein the first zoom-out region, the first zoom-in region, and the second zoom-out region are sequentially arranged in a first direction perpendicular to an optical axis of the one or more lenses.

In an exemplary embodiment, the first imaging region includes a first magnification region and a second magnification region, and the second imaging region includes a first demagnification region and a second demagnification region, wherein the first magnification region, the first demagnification region, the second magnification region, and the second demagnification region are sequentially arranged in a first direction perpendicular to an optical axis of the one or more lenses.

In an exemplary embodiment, the first imaging region includes at least two enlargement regions, and the second imaging region includes at least two reduction regions, wherein the at least two enlargement regions and the at least two second reduction regions are alternately arranged in a first direction perpendicular to an optical axis of the one or more lenses such that any two of the at least two enlargement regions are not adjacent and any two of the at least two reduction regions are not adjacent.

In one exemplary embodiment, the angular resolution of the camera module satisfies: (angular resolution max-angular resolution min)/angular resolution max is less than or equal to 0.99, wherein angular resolution max is the maximum angular resolution of the camera module, and angular resolution min is the minimum angular resolution of the camera module.

In an exemplary embodiment, the imaging system further comprises a control module coupled to the image sensor and configured to identify a target object based on the imagery, and to send an alert instruction to the display module upon determining that the belonging vehicle is in danger of collision with the identified target object.

According to another aspect of the present application, there is provided a lens group for coupling with an image sensor and forming an image on the image sensor by light from outside passing through the lens group, wherein the lens group includes a free-form surface lens having a non-rotationally symmetric mirror surface so that the image formed on the image sensor has a first imaging area and a second imaging area, the first imaging area and the second imaging area having different zoom magnifications from each other.

In one exemplary embodiment, the free-form surface lens has a convex object-side surface and a concave image-side surface.

In an exemplary embodiment, the first imaging region and the second imaging region are distributed in a first direction perpendicular to an optical axis of the lens group.

In an exemplary embodiment, the first imaging region includes a first magnification region and a second magnification region, and the second imaging region includes a first demagnification region, wherein the first magnification region, the first demagnification region, and the second magnification region are sequentially arranged in a first direction perpendicular to an optical axis of the lens group.

In an exemplary embodiment, the first imaging region includes a first zoom-in region, and the second imaging region includes a first zoom-out region and a second zoom-out region, wherein the first zoom-in region, the first zoom-out region, and the second zoom-out region are sequentially arranged in a first direction perpendicular to an optical axis of the lens group.

In an exemplary embodiment, the first imaging region includes a first zoom-in region and a second zoom-out region, and the second imaging region includes a first zoom-out region and a second zoom-out region, wherein the first zoom-in region, the first zoom-out region, the second zoom-in region, and the second zoom-out region are sequentially arranged in a first direction perpendicular to an optical axis of the lens group.

In an exemplary embodiment, the first imaging region includes at least two magnification regions, and the second imaging region includes at least two demagnification regions, wherein the at least two magnification regions and the at least two second demagnification regions are alternately arranged in a first direction perpendicular to an optical axis of the lens group such that any two of the at least two magnification regions are not adjacent and any two of the at least two demagnification regions are not adjacent.

In one exemplary embodiment, the lens group includes at least five lenses, and a lens closest to a subject among the at least five lenses is a free-form lens having a non-rotationally symmetric mirror surface.

In one exemplary embodiment, the lens group has at least one cemented lens.

According to another aspect of the present application, there is provided a camera module comprising a lens assembly as described above.

In one exemplary embodiment, the angular resolution of the camera module satisfies: (angular resolution max-angular resolution min)/angular resolution max is less than or equal to 0.99, wherein angular resolution max is the maximum angular resolution of the camera module and angular resolution min is the minimum angular resolution of the camera module.

The free-form surface lens with the non-rotationally symmetrical mirror surface is utilized, and the image height angle curves of the upper half area and the lower half area of the image surface are adjusted by adjusting the specific structure of the free-form surface lens, so that the objects in different areas can be amplified or reduced. When the camera module of the free-form surface lens comprising the non-rotation symmetrical mirror surface is applied to an imaging system for vehicle-assisted driving, a specific area (such as a slightly distant object or a pedestrian) can be selectively enlarged, and other specific areas (such as the ground close to a vehicle) can be compressed, so that the effective recognition of the slightly distant object or the pedestrian by a driver can be effectively improved, the reliability of system recognition can be improved, and further, an unexpected collision can be avoided during parking.

Drawings

Other features, objects, and advantages of the present application will become apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The same or similar elements in different drawings are denoted by the same reference numerals. In the drawings:

fig. 1 schematically shows an application scenario of a vehicle-mounted rearview mirror.

Fig. 2 schematically shows an image height angle curve of a camera module using a conventional optical lens.

Fig. 3 schematically shows a schematic view of an ideal imaging area of a camera module using a conventional optical lens.

Fig. 4 schematically shows a block diagram of an imaging system according to the present application. Fig. 5A schematically shows an image height angle diagram of a camera module according to an exemplary embodiment.

Fig. 5B shows a schematic image area diagram of a camera module according to an exemplary embodiment. Fig. 6A schematically shows an imaging effect diagram using an ideal linearly distributed lens.

Fig. 6B schematically shows an imaging effect diagram using a camera module according to an embodiment of the present application.

Fig. 7A schematically shows an image height angle diagram of a camera module according to another exemplary embodiment.

Fig. 7B shows a schematic image area diagram of a camera module according to another exemplary embodiment.

Fig. 8A schematically shows an image height angle diagram of a camera module according to another exemplary embodiment.

Fig. 8B shows a schematic image area diagram of a camera module according to another exemplary embodiment.

Fig. 9A schematically shows an image height angle diagram of a camera module according to another exemplary embodiment.

Fig. 9B shows a schematic image area diagram of a camera module according to another exemplary embodiment.

Fig. 10A and 10B schematically show a configuration diagram of a lens group according to an embodiment viewed from a first direction and a second direction, respectively.

Fig. 11 schematically shows an image height angle graph of an ideal linearly distributed lens and an image pickup module including the lens groups of fig. 10A and 10B.

Fig. 12 schematically shows an angular resolution plot of an ideal linearly distributed lens and a camera module comprising the lens groups of fig. 10A and 10B.

Fig. 13A and 13B schematically show structural diagrams of a lens group according to another embodiment viewed from a first direction and a second direction, respectively.

Fig. 14 schematically shows an image height angle graph of an ideal linearly distributed lens and a camera module including the lens groups of fig. 13A and 13B.

Fig. 15 schematically shows angular resolution plots of an ideal linearly distributed lens and a camera module comprising the lens groups of fig. 13A and 13B.

Fig. 16A and 16B schematically show structural diagrams of a lens group according to another embodiment viewed from a first direction and a second direction, respectively.

Fig. 17 schematically shows an image height angle graph of an ideal linearly distributed lens and an image pickup module including the lens groups of fig. 16A and 16B.

Fig. 18 schematically shows an angular resolution plot of an ideal linearly distributed lens and a camera module comprising the lens groups of fig. 16A and 16B.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings.

It will be understood that when an element or layer is referred to herein as being "on," "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. When an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term "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, expressions such as first, second, etc. are used only for distinguishing one feature from another feature, and do not indicate any limitation on the features. Thus, the first imaging zone discussed below may also be referred to as the second imaging zone, and similarly, the second imaging zone may also be referred to as the first imaging zone, without departing from the teachings of the present application.

Spatially relative terms, such as "under," "below," "under," "over," "upper," and the like, may be used herein for convenience of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" may encompass both an orientation above.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, features that are not limited to a single plural form are also intended to include plural forms of features unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, do not preclude the presence or addition of one or more other features, steps, elements, components, and/or groups thereof. Furthermore, when describing embodiments of the present application, the use of "may" mean "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to examples or illustrations.

As used herein, the terms "substantially," "about," and the like are used as terms of table approximation and not as terms of table degree, and are intended to account for inherent deviations in measured or calculated values that will be recognized by those of ordinary skill in the art.

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 present application, the embodiments and features of the embodiments may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Hereinafter, specific embodiments according to the present application will be described in detail with reference to the accompanying drawings.

Fig. 4 schematically shows a block diagram of an imaging system 10 according to the present application.

Referring to fig. 4, the imaging system 10 may include a camera module 100 and a display module 200. The camera module 100 is used to capture an image of a subject (e.g., a pedestrian or an object behind a vehicle). The camera module 100 may include a lens group 110, the lens group 110 having one or more lenses. The lens group 110 may include a free-form lens having a non-rotationally symmetric mirror surface. For example, the lens closest to the object side in the lens group 110 may be a free-form surface lens having a non-rotationally symmetric mirror surface. The non-rotationally symmetric mirror surface of the free-form surface lens may be disposed to be symmetric in a first direction perpendicular to the optical axis thereof and asymmetric in a second direction perpendicular to the optical axis and the first direction, but the present application is not limited thereto. In an alternative embodiment, the non-rotationally symmetric mirror surface of the free-form surface lens may also be arranged to be asymmetric in both a first direction perpendicular to its optical axis and a second direction perpendicular to the optical axis and the first direction.

In an exemplary embodiment, the imaging system 10 may be a rearview system for assisting in reversing the vehicle, and the camera module 100 may be a rearview lens for capturing images behind the vehicle.

In an exemplary embodiment, the lens group 110 may include seven lenses, and at least one of the seven lenses may be a free-form surface lens having a non-rotationally symmetric mirror surface, but the present application is not limited thereto. For example, the lens group 110 may include any number of lenses, such as five or six, and the optical parameters of the lenses are appropriately set, so that the lens group 110 can achieve effective enlargement or reduction of a specific area (compared to the imaging effect of an ideal linear distribution lens), and thus can improve the recognition reliability of the imaging system 10, which is included in the scope of the present application.

The camera module 100 may further include an image sensor 120, wherein the image sensor 120 is configured to receive light incident through the lens assembly 110, and the light incident through the lens assembly 110 forms an image on the image sensor, and the image may be converted into an electrical signal by the image sensor 120.

Since the lens group 110 has a free-form surface lens, a first imaging area and a second imaging area are formed on the image sensor 120, wherein an image in the first imaging area and an image in the second imaging area may have different zoom magnifications from each other. In an exemplary embodiment, the number of optical systems of the free-form-surface lens is selected such that the image in the first imaging region is enlarged and the image in the second imaging region is reduced. In application, the first imaging zone may correspond to an image of an object or pedestrian at a distance, while the second imaging zone may correspond to an image of the ground near the vehicle. The arrangement can effectively improve the reliability of system identification, and improve the effective identification of the driver to objects or pedestrians at a distance, thereby avoiding collision.

In some embodiments, the area of the first imaging region may be larger than the area of the second imaging region. In other embodiments, the area of the first imaging region may also be less than or equal to the area of the second imaging region. The area of the first imaging area and the area of the second imaging area can be set according to specific application conditions by adjusting the optical coefficient of the free-form-surface lens.

The display module 200 may be coupled with the image sensor 120 of the camera module 100, for receiving an electrical signal from the image sensor 120, and displaying an image based on the received electrical signal. The display module 200 may include a display screen for displaying images to a user, and the display screen may be, for example, a liquid crystal display screen, an electrophoretic display screen, an electrowetting display screen, and the like, but the application is not limited thereto.

In some exemplary embodiments, the imaging system 10 may further include a control module 300, and the control module 300 may be coupled with the image sensor 120 and the display module 200. The control module 300 may identify the subject based on the image received by the image sensor 120, and when it is determined that the belonging vehicle is in danger of collision with the identified subject, the control module 300 may send an alarm instruction to the display module 200. Alternatively, the control module 300 may be integrated with the display module 200.

Camera module

Specific examples of the camera module applicable to the above-described embodiments will be further described below with reference to the drawings.

Example 1

The camera module 100 according to embodiment 1 of the present application is described below with reference to fig. 5A to 6B.

The camera module 100 may include a lens group 110, the lens group 110 having one or more lenses. Lens group 110 may include a free-form lens having a non-rotationally symmetric mirror surface. By adjusting the structure and optical parameters of the free-form surface lens, the camera module 100 has an image height angle curve as shown in fig. 5A.

The imaging area of the camera module 100 is shown in fig. 5B. The imaging area is divided into an imaging area I and an imaging area II. The imaging regions i and ii are sequentially distributed in a first direction perpendicular to the optical axis of the lens group 110. In the imaging area I, the slope of the image high-angle curve is reduced, and the image is reduced; in imaging region II, the image height-angle curve slope increases and the image is magnified.

In this embodiment, the camera module 100 can enlarge one region (imaging region ii) and compress the other region (imaging region i).

The angular resolution of the camera module 100 of embodiment 1 can satisfy:

(angular resolution max-angular resolution min)/angular resolution max is less than or equal to 0.99.

Where angular resolution refers to the resolving power of an imaging system or a component of the system, i.e., the ability of the imaging system or system element to differentially distinguish between the minimum separation of two adjacent objects. The angular resolution is the product of the derivative of the image height angle and the pixel size, i.e.:

fig. 6A schematically shows an imaging effect diagram using an ideal linear distribution lens. Fig. 6B schematically shows an imaging effect diagram using the camera module of embodiment 1.

Referring to fig. 6A and 6B, the ideal linearly distributed lens has the characteristics of large size and small size during imaging, and has no targeted enlargement or reduction on the imaging area. Images obtained using a camera module of the free-form surface scheme can achieve targeted magnification of, for example, the area a, compared to images obtained using a linear distribution lens. Therefore, the camera module according to the present application can improve the magnification of a specific area. When the camera module according to the present application is applied to a parking assist function or the like, it is possible to improve the magnification of, for example, an object or a pedestrian at a distance, thereby improving the recognition reliability of the system.

Example 2

A camera module 100 according to embodiment 2 of the present application is described below with reference to fig. 7A and 7B. In this embodiment and the following embodiments, descriptions of parts similar to those of embodiment 1 will be omitted for the sake of brevity.

The camera module 100 may include a lens group 110, the lens group 110 having one or more lenses. The lens group 110 may include a free-form lens having a non-rotationally symmetric mirror surface. By adjusting the structure and optical parameters of the free-form surface lens, the camera module 100 has an image height angle curve as shown in fig. 7A.

The imaging area of the camera module 100 is shown in fig. 7B. The imaging area is divided into an imaging area I, an imaging area II, and an imaging area III. In the imaging area I, the slope of the image height angle curve is reduced, and the image is reduced; in the imaging area II, the slope of the image high-angle curve is increased, and the image is amplified; in the imaging region III, the slope of the image height angle curve is reduced, and the image is reduced. The imaging region i, the imaging region ii, and the imaging region iii are sequentially arranged in a first direction perpendicular to the optical axis of the lens group 110.

In this embodiment, the camera module 100 can enlarge one region (i.e., ii) and compress two regions (i.e., iii).

The angular resolution of the camera module 100 may be such that:

Example 3

A camera module 100 according to embodiment 3 of the present application is described below with reference to fig. 8A and 8B.

The camera module 100 may include a lens group 110, the lens group 110 having one or more lenses. The lens group 110 may include a free-form lens having a non-rotationally symmetric mirror surface. By adjusting the structure and optical parameters of the free-form surface lens, the camera module 100 has an image height angle curve as shown in fig. 8A.

The imaging area of the camera module 100 is shown in fig. 8B. The imaging area is divided into an imaging area I, an imaging area II, and an imaging area III. In the imaging area I, the slope of an image high-angle curve is increased, and an image is amplified; in the imaging area II, the slope of the image height angle curve is reduced, and the image is reduced; and in the imaging area III, the slope of the image height angle curve is increased, and the image is amplified. The imaging region i, the imaging region ii, and the imaging region iii are sequentially arranged in a first direction perpendicular to the optical axis of the lens group 110.

In the present embodiment, the camera module 100 can achieve the enlargement of two areas (imaging area i and imaging area iii) while compressing one area (imaging area ii).

The angular resolution of the camera module 100 may satisfy:

Example 4

A camera module 100 according to embodiment 4 of the present application is described below with reference to fig. 9A and 9B.

The camera module 100 may include a lens group 110, the lens group 110 having one or more lenses. The lens group 110 may include a free-form lens having a non-rotationally symmetric mirror surface. By adjusting the structure and optical parameters of the free-form surface lens, the camera module 100 has an image height angle curve as shown in fig. 9A.

The imaging area of the camera module 100 is shown in fig. 9B. The imaging area is divided into an imaging area I, an imaging area II, an imaging area III, and an imaging area IV. In the imaging area I, the slope of the image high-angle curve is increased, and the image is amplified; in the imaging area II, the slope of the image height angle curve is reduced, and the image is reduced; in the imaging area III, the slope of the image high-angle curve is increased, and the image is amplified; in the imaging region iv, the image height-angle curve slope decreases and the image is narrowed. The imaging region i, the imaging region ii, the imaging region iii, and the imaging region iv are sequentially arranged in a first direction perpendicular to the optical axis of the lens group 110.

In the present embodiment, the camera module 100 can perform enlargement of two regions (imaging region i and imaging region iii) while compressing one region (imaging region ii and imaging region iv).

The angular resolution of the camera module 100 may satisfy:

Note that the arrangement of the enlargement area and the reduction area is not limited to the above embodiments. In some alternative embodiments, the first imaging region may include at least two enlargement regions, and the second imaging region may include at least two reduction regions. The at least two magnification areas and the at least two second reduction areas are alternately arranged in a first direction perpendicular to the optical axis of the lens group such that any two magnification areas of the at least two magnification areas are not adjacent and any two reduction areas of the at least two reduction areas are not adjacent.

Lens group

Specific examples of lens groups applicable to the above-described embodiments will be further described below with reference to the drawings. It is to be understood that the imaging effect described in any of embodiments 1 to 4 above can be exhibited by a camera module equipped with the lens group described in any of embodiments 5 to 7 below by appropriately setting the optical parameters of a free-form surface lens having a non-rotationally symmetrical mirror surface and adaptively adjusting the optical parameters of other lenses.

Example 5

A lens group 110-1 according to embodiment 5 of the present application is described below with reference to fig. 10A to 12. Fig. 10A and 10B schematically show a configuration diagram of a lens group 110-1 of example 5 viewed from a first direction and a second direction, respectively. Wherein fig. 10A shows a structural view of the lens group 110-1 viewed in a first direction perpendicular to a plane defined by an optical axis (Z axis) and a first axis (X axis) of the lens group 110-1; fig. 10B shows a structural diagram of the lens group 110-1 viewed in a second direction perpendicular to a plane defined by the optical axis (Z axis) and the second axis (Y axis). The first axis (X axis) direction, the optical axis (Z axis) direction and the second axis (Y axis) direction are vertical to each other.

Referring to fig. 10A and 10B, the lens group 110-1 may include seven lenses, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7, respectively, which are sequentially arranged along the optical axis (Z axis). Optionally, the lens group 110-1 may further include a stop STO disposed between the fourth lens L4 and the fifth lens L5. The stop STO can be used to limit the light to improve the image clarity of the optical system.

The object-side surface of the first lens element L1 is convex, and the image-side surface thereof is concave. The object-side surface of the second lens element L2 is convex, and the image-side surface thereof is concave. The object-side surface of the third lens element L3 is concave, and the image-side surface thereof is convex. The object-side surface of the fourth lens element L4 is convex, and the image-side surface thereof is convex. The object-side surface of the fifth lens element L5 is convex, and the image-side surface thereof is convex. The object-side surface of the sixth lens element L6 is concave, and the image-side surface thereof is concave. The object-side surface of the seventh lens element L7 is convex, and the image-side surface thereof is convex. Alternatively, the fifth lens L5 and the sixth lens L6 may form a cemented lens.

Table 1 shows a basic parameter table of the lens group 110-1 of example 5 in which the unit of the radius of curvature and the thickness/distance are millimeters (mm).

Noodle number	Radius of curvature	Thickness/distance	Refractive index Nd	Abbe number Vd
					1	12.4126	0.900216	1.77	49.61
2	4.105061	2.19839
					3	7.391853	0.591153	1.51	54.57
4	2.290188	2.505745
					5	-3.32184	1.880377	1.59	61.12
6	-31.2268	0.178553
					7	5.068945	2.478768	1.74	49.36
8	-18.7405	-0.0235
					STO	Infinity(s)	0.142695
10	3.338292	2.439261	1.50	81.59
					11	-2.13279	0.619512	1.78	25.72
12	8.152591	0.242686
					13	4.973172	1.601856	1.59	61.12
14	-5.1805	0.1

TABLE 1

The total focal length EFL of the lens group 110-1 is 1.78mm, the maximum field angle FOV of the lens group 110-1 is 97.5 °, the distance TTL on the optical axis from the center of the object-side surface of the first lens L1 to the image plane (not shown) is 18.31mm, and the image height H on the image plane is 2.88 mm.

In the present embodiment, the first lens L1 may be a free-form surface lens having a non-rotationally symmetric mirror surface. The first lens L1 may be disposed to be symmetrical in the first axis (X axis) direction and asymmetrical in the second axis (Y axis) direction.

Wherein the surface shape of the non-rotationally symmetric mirror surface can be defined using, but not limited to, the following formula:

when the free-form surface is at the position with the height of r along the optical axis direction, the Z is the distance rise from the vertex of the free-form surface; c is the paraxial curvature of the free-form surface, and c is 1/R (namely, the paraxial curvature c is the reciprocal of the curvature radius R); k is the conic coefficient conc; ei is XⁿY^mAi is X_nY_mThe corresponding numerical value. Table 2 below shows the high-order term coefficients of each non-rotationally symmetric mirror surface that can be used in example 5.

Noodle numbering	X⁰Y¹	X²Y¹	X⁰Y³	X⁴Y¹	X²Y³
						1	0.026138	-0.00761	-0.00219	4.6254E-05	0.000394778
2	-0.09147	-0.0088	0.006357	-0.00085481	-0.000549442

Noodle numbering	X⁰Y⁵	X⁶Y¹	X⁴Y³	X²Y⁵	X⁰Y⁷
						1	2.71078E-05	1.22402E-06	-1.53618E-06	-5.73824E-06	4.88177E-07
2	-0.001392029	-1.30E-05	2.59E-05	1.58E-05	4.82E-05

TABLE 2

In the present embodiment, the third lens L3, the fourth lens L4, and the seventh lens L7 may be aspheric lenses having rotationally symmetric mirror surfaces. The profile x of each aspheric lens can be defined using, but not limited to, the following aspheric equation:

z is the distance rise from the vertex of the aspheric surface 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 inverse of the radius of curvature in table 1 above); k is the conic coefficient conc; A. b, C, D, E are all high order term coefficients. Table 3 below shows the conic coefficients K and the high-order term coefficients A, B, C, D and E of each aspherical lens surface that can be used in example 5.

TABLE 3

By applying a free-form surface lens (e.g., the first lens L1) in the lens group 110-1, a specific imaging region can be enlarged or reduced (compared with the imaging effect of an ideal linearly distributed lens) by reasonably adjusting the structure and optical coefficient of the free-form surface, and the imaging sharpness of the specific region can be effectively improved.

Fig. 11 schematically shows an image height angle graph of an ideal linearly distributed lens and a camera module including the lens group 110-1 of embodiment 5. Fig. 12 schematically shows an angular resolution graph of an ideal linearly distributed lens and a camera module including the lens group 110-1 of embodiment 5.

Referring to fig. 11, an ideal linear profile lens has an image height angle curve with a constant slope. The linear distribution lens has the characteristics of large distance and small distance during imaging, and has no targeted amplification or reduction on an imaging area. Compared with a linearly distributed lens, the camera module including the lens group 110-1 of embodiment 5 has a decreased slope in the imaging zone i so that the image in the imaging zone i is compressed, and has an increased slope in the imaging zone ii so that the image in the imaging zone ii is enlarged.

Referring to fig. 12, an ideal linear distribution lens has a constant angular resolution that is symmetric about the longitudinal axis. In contrast to the linear distribution lens, the image pickup module including the lens group 110-1 of example 5, in which the angular resolution is not symmetrical about the longitudinal axis, has an angular resolution maximum (angular resolution max) of 11.996 and an angular resolution minimum (angular resolution min) of 8.081, satisfying (angular resolution max-angular resolution min)/angular resolution max of 0.327.

Example 6

A lens group 110-2 according to embodiment 6 of the present application is described below with reference to fig. 13A to 15. Fig. 13A and 13B schematically show a configuration diagram of a lens group 110-2 of example 6 viewed from a first direction and a second direction, respectively. Wherein fig. 13A shows a structural view of the lens group 110-2 viewed in a first direction perpendicular to a plane defined by an optical axis (Z axis) and a first axis (X axis) of the lens group 110-2; fig. 13B shows a structural view of the lens group 110-2 viewed in a second direction perpendicular to a plane defined by the optical axis (Z axis) and the second axis (Y axis). The first axis (X axis) direction, the optical axis (Z axis) direction and the second axis (Y axis) direction are vertical to each other.

Referring to fig. 13A and 13B, the lens group 110-2 may include six lenses, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6, which are sequentially arranged along an optical axis (Z axis). Optionally, the lens group 110-2 may further include a stop STO (not shown) disposed between the third lens L3 and the fourth lens L4. The stop STO can be used to limit the light to improve the image clarity of the optical system.

The object-side surface of the first lens element L1 is convex, and the image-side surface thereof is concave. The object-side surface of the second lens element L2 is concave, and the image-side surface thereof is concave. The object-side surface of the third lens element L3 is convex, and the image-side surface thereof is convex. The object-side surface of the fourth lens element L4 is convex, and the image-side surface thereof is convex. The fifth lens element L5 has a concave object-side surface and a concave image-side surface. The object-side surface of the sixth lens element L6 is convex, and the image-side surface thereof is convex. Alternatively, the fourth lens L4 and the fifth lens L5 may form a cemented lens.

Table 4 shows a basic parameter table of the lens group 110-2 of example 6, in which the unit of the radius of curvature and the thickness/distance are both millimeters (mm).

Noodle numbering	Radius of curvature	Thickness/distance	Refractive index Nd	Abbe number Vd
					1	16.09987	1.002159	1.77	49.6
2	4.424192	4.166034
					3	-69.6696	0.891153	1.51	57.0
4	1.703737	1.768486
					5	4.715727	4.250079	1.90	31.3
6	-52.1502	0.541539
					STO	Infinity(s)	-0.17514
8	3.145302	1.489979	1.54	56.1
					9	-3.375	0.6	1.64	23.5
10	4.841975	0.220777
					11	3.217852	1.879284	1.54	56.1
12	-4.4953	0.1

TABLE 4

The total focal length EFL of the lens group 110-2 is 1.96mm, the maximum field angle FOV of the lens group 110-1 is 195 °, the distance TTL from the center of the object-side surface of the first lens L1 to the image plane (not shown) on the optical axis is 19.43mm, and the image height H on the image plane is 2.88 mm.

In the present embodiment, the first lens L1 may be a free-form surface lens having a non-rotationally symmetric mirror surface. The first lens L1 may be disposed symmetrically in the first axis (X-axis) direction and asymmetrically in the second axis (Y-axis) direction. The surface shape of each non-rotationally symmetric mirror surface can be defined using, but not limited to, formula (1) in example 5. Table 5 below shows the conic coefficient K and the high-order term coefficient of each non-rotationally symmetric mirror surface that can be used in example 6.

Noodle number	K	X¹Y⁰	X²Y⁰	X⁰Y²	X³Y⁰
						1	0.147384924	0.080691	-0.010555107	-0.003080755	-0.004554506
2	-0.217068251	0.075741	-0.053730419	-0.04514053	-0.004523278

Noodle number	X³Y²	X¹Y⁴	X⁶Y⁰	X⁴Y²	X²Y⁴
						1	3.05598E-05	4.78E-05	-3.14681E-06	-4.24738E-05	-9.88839E-06
2	-0.000154398	0.00011	-4.49965E-05	-0.000415324	-0.000190816

Noodle numbering	X⁰Y⁶	X⁷Y⁰	X⁵Y²	X³Y⁴	X¹Y⁶
						1	-3.55559E-08	-1.8E-07	-5.46698E-07	-2.78013E-07	-2.49225E-07
2	1.42465E-05	-4.8E-06	-9.38305E-06	-2.19038E-05	-1.18365E-05

TABLE 5

In the present embodiment, the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 may be aspherical lenses having rotationally symmetric mirror surfaces. The surface type of each aspherical lens can be defined using, but not limited to, formula (2) in example 5. Table 6 below shows the conic coefficient K and the high-order term coefficients A, B, C, D and E for each aspherical lens surface that can be used in example 6.

Noodle number	K	A	B	C	D	E
								3	121.1177244	-0.00705	0.000807354	-5.99283E-05	2.62578E-06	-4.81093E-08
4	-1.021798351	-0.00952	0.000904664	7.93159E-07	-4.14268E-06	8.19792E-07
							8	-1.402315416	0.006195	-0.000689279	0.001168004	-0.000267341	-3.71957E-05
9	-45.74140153	-0.34365	0.178736846	-0.083647103	0.018881497	-0.001011533
							10	-37.53947404	-0.01396	0.014915853	-0.00343264	0.000428026	5.54877E-06
11	-13.85333837	-0.01133	0.001592146	-6.57732E-05	0.000212803	-3.0785E-05
							12	0.742919327	0.004226	-0.000685825	0.000431752	-6.8974E-05	1.30483E-05

TABLE 6

By applying a free-form surface lens (e.g., the first lens L1) in the lens group 110-2, it is possible to enlarge or reduce a specific imaging region and effectively improve the imaging sharpness of the specific region by appropriately adjusting the structure and optical coefficient of the free-form surface.

Fig. 14 schematically shows an image height angle graph of an ideal linearly distributed lens and a camera module including the lens group 110-2 of embodiment 6. Fig. 15 schematically shows an angular resolution graph of an ideal linearly distributed lens and a camera module including the lens group 110-2 of embodiment 6.

Referring to fig. 14, an ideal linear distribution lens has an image height angle curve with a constant slope. Compared with a linear distribution lens, the camera module including the lens group 110-2 of embodiment 6 has a reduced slope in the imaging region i, so that an image in the imaging region i is compressed; the slope is increased in the imaging area II, so that the image in the imaging area II is amplified; and the slope is decreased in the imaging zone iii so that the image in the imaging zone iii is compressed.

Referring to fig. 15, an ideal linear distribution lens has a constant angular resolution that is symmetric about the longitudinal axis. In contrast to the linear distribution lens, the image pickup module including the lens group 110-2 of example 6, in which the angular resolution is not symmetrical about the longitudinal axis, has an angular resolution maximum value (angular resolution max) of 11.339 and an angular resolution minimum value (angular resolution min) of 3.895, and satisfies (angular resolution max-angular resolution min)/angular resolution max of 0.657.

Example 7

A lens group 110-3 according to embodiment 7 of the present application is described below with reference to fig. 16A to 18. Fig. 16A and 16B schematically show the configuration of the lens group 110-3 of example 7 viewed from a first direction and a second direction, respectively. Wherein fig. 16A shows a structural view of the lens group 110-3 viewed in a first direction perpendicular to a plane defined by an optical axis (Z axis) and a first axis (X axis) of the lens group 110-3; fig. 16B shows a structural diagram of the lens group 110-3 viewed in a second direction perpendicular to a plane defined by the optical axis (Z axis) and the second axis (Y axis). The first axis (X axis) direction, the optical axis (Z axis) direction and the second axis (Y axis) direction are vertical to each other.

Referring to fig. 16A and 16B, the lens group 110-3 may include five lenses, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5, which are sequentially arranged along the optical axis (Z axis). Optionally, the lens group 110-3 may further include a stop STO (not shown) disposed between the third lens L3 and the fourth lens L4. The stop STO can be used to limit the light to improve the image clarity of the optical system.

The object-side surface of the first lens element L1 is convex, and the image-side surface thereof is concave. The object-side surface of the second lens element L2 is convex, and the image-side surface thereof is concave. The object-side surface of the third lens element L3 is convex, and the image-side surface thereof is convex. The object-side surface of the fourth lens element L4 is concave, and the image-side surface thereof is concave. The object-side surface of the fifth lens element L5 is convex, and the image-side surface thereof is convex. Alternatively, the fourth lens L4 and the fifth lens L5 may form a cemented lens.

Table 7 shows a basic parameter table of the lens group 110-3 of example 7 in which the units of the radius of curvature and the thickness/distance are millimeters (mm).

Noodle number	Radius of curvature	Thickness/distance	Refractive index Nd	Abbe number Vd
					1	12.13484	1.219123	1.77	49.6
2	3.156693	1.296049
					3	4.671986	0.924609	1.51	56.3
4	1.02523	1.373236
					5	3.007588	3.103649	1.58	30.2
6	-2.46798	0.235533
					STO	Infinity	0.023903
8	-6.17764	0.617891	1.58	30.2
					9	0.76586	1.825402	1.54	56.0
10	-1.62038	0.187

TABLE 5

The total focal length EFL of the lens group 110-3 is 1.34mm, the maximum field angle FOV of the lens group 110-1 is 60 °, the distance TTL on the optical axis from the center of the object-side surface of the first lens L1 to the imaging surface (not shown) is 13.27mm, and the image height H on the imaging surface is 1.789 mm.

In the present embodiment, the first lens L1 may be a free-form surface lens having a non-rotationally symmetric mirror surface. The first lens L1 may be disposed to be symmetrical in the first axis (X axis) direction and asymmetrical in the second axis (Y axis) direction. The surface shape of each non-rotationally symmetric mirror surface can be defined using, but not limited to, formula (1) in example 5. Table 8 below shows the conic coefficient K and the high-order term coefficient of each non-rotationally symmetric mirror surface that can be used in example 7.

Noodle numbering	K	X⁰Y¹	X²Y⁰	X⁰Y²
					1	0.511247039	0.104484	0.004881141	0.003382697
2	-0.03693151	-0.05744	-0.014895503	-0.016855535

Noodle number	X²Y¹	X⁰Y³	X⁴Y⁰	X²Y²
					1	-0.018343283	-0.01521	4.58645E-06	0.00339128
2	-0.027099576	-0.02101	0.000512196	0.015114437

Noodle number	X⁰Y⁴	X⁴Y¹	X²Y³	X⁰Y⁵
					1	0.000250532	0.000449	0.000391984	0.000342481
2	0.004853067	-0.00206	-0.007684383	-0.002320289

Noodle numbering	X⁶Y⁰	X⁴Y²	X²Y⁴	X⁰Y⁶
					1	7.47668E-08	-0.00012	-0.000118143	3.07475E-06
2	6.42526E-05	-0.00019	0.000564183	0.000125093

TABLE 8

In the present embodiment, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 may be aspherical lenses having rotationally symmetric mirror surfaces. The surface type of each aspherical lens can be defined using, but not limited to, formula (2) in example 5. Table 9 below shows the conic coefficients K and the high-order term coefficients A, B, C, D and E of each aspherical lens surface that can be used in example 7.

Noodle numbering	K	A	B	C	D	E
							3	-0.796525516	0.00104	-0.000825184	3.1906E-06	8.72932E-06	-9.73986E-07
4	-1.056710894	0.036496	0.00261949	-0.001112415	-0.000298471	9.94041E-06
							5	-1.731307667	0.023773	0.003888712	-0.000736568	0.000323182	-5.66298E-05
6	-21.78908402	-0.14944	0.166892183	-0.281134499	0.274441768	-0.108611636
							9	-0.441603511	0.717901	-2.511277803	2.541098753	-1.04619967	-0.122467524

TABLE 9

By applying a free-form surface lens (e.g., the first lens L1) in the lens group 110-3, it is possible to achieve enlargement or reduction of a specific imaging region and effectively improve the imaging sharpness of the specific region by appropriately adjusting the structure and optical coefficient of the free-form surface.

Fig. 17 schematically shows a graph of image height angle of an ideal linearly distributed lens and a camera module including the lens group 110-3 of embodiment 7. Fig. 18 schematically shows an angular resolution graph of an ideal linearly distributed lens and a camera module including the lens group 110-3 of embodiment 7.

Referring to fig. 17, an ideal linear profile lens has an image height angle curve with a constant slope. The camera module including the lens group 110-3 of embodiment 7 has an increased slope in the imaging region i compared to the linear distribution lens, so that the image in the imaging region i is enlarged; the slope is reduced in the imaging area II, so that the image in the imaging area II is compressed; and the slope increases in the imaging zone iii so that the image in the imaging zone iii is magnified.

Referring to fig. 18, an ideal linear distribution lens has a constant angular resolution that is symmetric about the longitudinal axis. In contrast to the linear distribution lens, the image pickup module including the lens group 110-3 of example 7, in which the angular resolution is not symmetrical about the longitudinal axis, has an angular resolution maximum value (angular resolution max) of 16.487 and an angular resolution minimum value (angular resolution min) of 7.112, satisfying (angular resolution max-angular resolution min)/angular resolution max of 0.569.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A camera module includes a lens group coupled with an image sensor, and light from the outside passing through the lens group forms an image on the image sensor,

the lens group comprises a free-form surface lens with a non-rotation symmetrical mirror surface, and the specific structure of the free-form surface lens is adjusted to be an image height angle curve of an upper half area and a lower half area of an image surface, so that the image formed on the image sensor is provided with a first imaging area and a second imaging area, and the first imaging area and the second imaging area have different scaling magnifications;

the angular resolution of the camera module satisfies: the angular resolution max-angular resolution min/angular resolution max is more than or equal to 0.327 and less than or equal to 0.99,

wherein the angular resolution max is a maximum angular resolution of the camera module and the angular resolution min is a minimum angular resolution of the camera module.

2. The camera module of claim 1, wherein the free-form surface lens is symmetric in a first direction perpendicular to an optical axis thereof and asymmetric in a second direction perpendicular to the optical axis and the first direction.

3. The image pickup module according to claim 1 or 2, wherein the number of optical systems of the free-form-surface lens is selected such that an image in the first imaging region is enlarged and an image in the second imaging region is reduced.

4. The camera module of claim 3, wherein the area of the first imaging region is larger than the area of the second imaging region.

5. A camera module according to claim 3, wherein the area of the first imaging zone is less than or equal to the area of the second imaging zone.

6. The camera module of claim 3, wherein the first and second imaging regions are distributed in a first direction perpendicular to an optical axis of the lens group.

7. The camera module of claim 3, wherein the first imaging region includes a first zoom-in region and a second zoom-in region, and the second imaging region includes a first zoom-out region,

wherein the first magnification area, the first demagnification area, and the second magnification area are sequentially arranged in a first direction perpendicular to an optical axis of the lens assembly.

8. The camera module of claim 3, wherein the first imaging region comprises a first zoom-in region and the second imaging region comprises a first zoom-out region and a second zoom-out region,

wherein the first zoom-out region, the first zoom-in region, and the second zoom-out region are sequentially arranged in a first direction perpendicular to an optical axis of the lens group.

9. The camera module of claim 3, wherein the first imaging region includes a first zoom-in region and a second zoom-in region, and the second imaging region includes a first zoom-out region and a second zoom-out region,

wherein the first magnification area, the first demagnification area, the second magnification area and the second demagnification area are arranged in sequence in a first direction perpendicular to an optical axis of the lens assembly.

10. The camera module of claim 3, wherein said first imaging region comprises at least two zoom-in regions and said second imaging region comprises at least two zoom-out regions,

wherein the at least two magnification areas and the at least two second demagnification areas are alternately arranged in a first direction perpendicular to the optical axis of the lens group such that any two of the at least two magnification areas are not adjacent and any two of the at least two demagnification areas are not adjacent.

11. An imaging system for vehicle driver assistance, the imaging system comprising a camera module having one or more lenses and a display module,

wherein the camera module further comprises an image sensor for receiving light from outside through the one or more lenses, the light forming an image on the image sensor, the image sensor being configured to convert the image into an electrical signal, and

wherein the display module receives the electrical signal from the image sensor and displays an image based on the electrical signal,

it is characterized in that the preparation method is characterized in that,

the one or more lenses comprise a free-form surface lens with a non-rotational symmetric mirror surface, and the specific structure of the free-form surface lens is adjusted to adjust the image height angle curve of the upper half area and the lower half area of the image surface, so that the image formed on the image sensor has a first imaging area and a second imaging area, and the first imaging area and the second imaging area have different zoom magnifications;

12. The imaging system of claim 11, wherein the free-form surface lens is symmetric in a first direction perpendicular to an optical axis thereof and asymmetric in a second direction perpendicular to the optical axis and the first direction.

13. The imaging system according to claim 11 or 12, wherein the optical number of the free-form surface lens is selected such that the image in the first imaging region is enlarged and the image in the second imaging region is reduced.

14. The imaging system of claim 13, wherein the area of the first imaging zone is greater than the area of the second imaging zone.

15. The imaging system of claim 13, wherein the area of the first imaging zone is less than or equal to the area of the second imaging zone.

16. The imaging system of claim 13, wherein the first imaging zone and the second imaging zone are distributed in a first direction perpendicular to an optical axis of the one or more lenses.

17. The imaging system of claim 13, wherein the first imaging region includes a first magnified region and a second magnified region and the second imaging region includes a first demagnified region,

wherein the first magnification region, the first demagnification region and the second magnification region are arranged sequentially in a first direction perpendicular to an optical axis of the one or more lenses.

18. The imaging system of claim 13, wherein the first imaging region comprises a first zoomed-in region and the second imaging region comprises a first zoomed-out region and a second zoomed-out region,

wherein the first reduction region, the first enlargement region, and the second reduction region are sequentially arranged in a first direction perpendicular to an optical axis of the one or more lenses.

19. The imaging system of claim 13, wherein the first imaging region includes a first zoomed-in region and a second zoomed-in region, and the second imaging region includes a first zoomed-out region and a second zoomed-out region,

wherein the first magnification area, the first demagnification area, the second magnification area and the second demagnification area are arranged sequentially in a first direction perpendicular to an optical axis of the one or more lenses.

20. The imaging system of claim 13, wherein the first imaging region includes at least two magnification regions and the second imaging region includes at least two demagnification regions,

wherein the at least two magnification regions and the at least two second demagnification regions are alternately arranged in a first direction perpendicular to the optical axis of the one or more lenses such that any two magnification regions of the at least two magnification regions are not adjacent and any two demagnification regions of the at least two demagnification regions are not adjacent.

21. The imaging system of claim 11, wherein the imaging system further comprises a control module,

the control module is coupled with the image sensor and configured to identify a target object based on the image and send an alarm instruction to the display module when the belonging vehicle is determined to have a collision risk with the identified target object.