Vehicle-mounted lens and vehicle-mounted camera system
By designing a staged zoom vehicle lens, using positive and negative power lenses and aspherical lenses, the problem of vehicle lenses being unable to adjust the image size was solved, achieving flexible imaging adaptation and high-quality imaging effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING JINGWEI HIRAIN TECH CO INC
- Filing Date
- 2022-11-16
- Publication Date
- 2026-07-07
AI Technical Summary
Existing vehicle-mounted lenses cannot adjust the size of the image they project onto the detector target surface according to the location, distance, and size of the target outside the vehicle, resulting in a fixed observation range that cannot meet the imaging needs of different situations.
Design a vehicle-mounted lens that uses a staged zoom method. By configuring positive and negative power lenses and aspherical lenses, it can achieve zoom between 22 mm, 115 mm and 450 mm. The lens group is slidably connected on the optical axis to avoid complex nonlinear zoom curves and cam grooves, thus ensuring image quality.
It enables the magnification or reduction of targets outside the vehicle as needed while keeping the detection location unchanged, meeting the imaging requirements for large-scale search and detailed investigation, while avoiding changes in imaging quality due to processing errors, and improving aberration correction and imaging quality.
Smart Images
Figure CN115755353B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of optical imaging and detection technology, and in particular relates to a vehicle-mounted lens and a vehicle-mounted camera system. Background Technology
[0002] Vehicle-mounted cameras can be used to collect road condition information, such as pedestrians crossing the road, road geometry, road surface conditions, road hazards, and traffic conditions. Existing vehicle-mounted cameras are generally fixed-focal-length lenses. Based on the relationship between focal length, field of view, and image height, once the focal length and image height are determined, the field of view is also fixed, and the observation range is thus fixed. This makes it impossible to adjust the size of the image projected onto the detector target surface according to the location, distance, and size of targets outside the vehicle. Summary of the Invention
[0003] The purpose of this application is to provide a vehicle-mounted lens and a vehicle-mounted camera system, which aims to solve the problem that existing vehicle-mounted lenses cannot adjust the size of the image they produce on the detector target surface according to the location, distance, and size of the target outside the vehicle.
[0004] The first aspect of this application provides a vehicle-mounted lens, which, from the object side to the image side, comprises: a first lens with positive optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, and an eighth lens with negative optical power. The vehicle-mounted lens is configured to perform staged zooming between focal lengths of 22 mm, 115 mm, and 450 mm. The second, third, and fourth lenses are configured to move simultaneously along the optical axis during zooming, the fifth and sixth lenses are configured to move simultaneously along the optical axis during zooming, and the first, seventh, and eighth lenses are configured to remain in their original positions during zooming. At least two lenses in the vehicle-mounted lens are aspherical lenses.
[0005] In some embodiments, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all aspherical lenses.
[0006] In some embodiments, the vehicle-mounted lens further includes an aperture stop disposed on the object side of the fifth lens.
[0007] In some embodiments, the vehicle-mounted lens further includes a lens barrel, in which a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens are located. A straight groove is provided on the inner wall surface of the lens barrel. The second lens, the third lens, and the fourth lens are slidably connected to the straight groove as a whole, and the fifth lens and the sixth lens are slidably connected to the straight groove as a whole.
[0008] In some embodiments, the angle between the principal ray and the optical axis in each field of view during zooming of the vehicle-mounted lens is less than 6.5°.
[0009] In some embodiments, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the eighth lens are all germanium lenses, and the second lens and the seventh lens are zinc selenide lenses.
[0010] In some embodiments, the first lens includes a first arc surface and a second arc surface arranged sequentially along the optical axis, and both the first arc surface and the second arc surface are convex surfaces relative to the incident light side.
[0011] The second lens includes a third arc surface and a fourth arc surface arranged sequentially along the optical axis, and both the third arc surface and the fourth arc surface are convex surfaces relative to the incident side of the light.
[0012] The third lens includes a fifth arc surface and a sixth arc surface arranged sequentially along the optical axis. Both the fifth and sixth arc surfaces are convex surfaces relative to the incident side of the light.
[0013] The fourth lens includes a seventh arc surface and an eighth arc surface arranged sequentially along the optical axis. The seventh arc surface is concave on the side where the light is incident, and the eighth arc surface is convex on the side where the light is incident.
[0014] The fifth lens includes a ninth and a tenth arc surface arranged sequentially along the optical axis, both of which are convex surfaces relative to the incident side of the light rays;
[0015] The sixth lens includes an eleventh arc surface and a twelfth arc surface arranged sequentially along the optical axis. The eleventh arc surface is convex on the side opposite to the incident light, and the twelfth arc surface is concave on the side opposite to the incident light.
[0016] The seventh lens includes a thirteenth and a fourteenth arc surface arranged sequentially along the optical axis, both of which are concave on the side opposite to the incident light.
[0017] The eighth lens includes a fifteenth and a sixteenth arc surface arranged sequentially along the optical axis. Both the fifteenth and sixteenth arc surfaces are concave on the side opposite to the incident light.
[0018] In some embodiments, the fourth, sixth, eighth, ninth, eleventh, thirteenth, and fifteenth arc surfaces are all aspherical surfaces.
[0019] A second aspect of this application provides a vehicle-mounted camera system, including a vehicle-mounted lens according to any of the above embodiments.
[0020] Compared with existing technologies, the vehicle-mounted lens provided in this application embodiment can magnify or reduce the size of targets outside the vehicle as needed while keeping the detection location unchanged, achieving the purpose of wide-range searching and detailed investigation of targets outside the vehicle. Moreover, compared with traditional continuous zoom, the lens in this application embodiment uses staged zoom between focal lengths of 22 mm, 115 mm, and 450 mm, avoiding the design of complex nonlinear zoom curves and the machining of complex nonlinear zoom cam grooves. Furthermore, at least two lenses in the vehicle-mounted lens are aspherical lenses, which can maintain good aberration correction to achieve the required performance. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 A schematic diagram of the optical system of a vehicle-mounted lens with a focal length of 22mm provided in some embodiments of this application;
[0023] Figure 2 for Figure 1 A schematic diagram of light propagation from a vehicle-mounted camera.
[0024] Figure 3 A schematic diagram of light propagation in an optical system of a vehicle-mounted lens with a focal length of 115mm, provided in some embodiments of this application;
[0025] Figure 4 A schematic diagram of light propagation in an optical system of a vehicle-mounted lens with a focal length of 450mm, provided for some embodiments of this application;
[0026] Figures 5a-5c The diagrams show the focal lengths of the vehicle-mounted lens in Example 1, which are 22mm, 115mm, and 450mm, respectively.
[0027] Figures 6a-6c The wavelet aberration root mean square plots of the vehicle-mounted lens in Example 1 with focal lengths of 22mm, 115mm, and 450mm are shown respectively.
[0028] Figures 7a-7c The distortion images are for the vehicle-mounted lens of Example 1 with focal lengths of 22mm, 115mm, and 450mm, respectively.
[0029] Figures 8a-8cThe MTF (Modulation Transfer Function) curves for the vehicle-mounted lens of Example 1 with focal lengths of 22mm, 115mm, and 450mm are shown respectively.
[0030] Figures 9a-9c The diagrams show the focal lengths of the vehicle-mounted lens in Example 2, which are 22mm, 115mm, and 450mm, respectively.
[0031] Figures 10a-10c The wavefront aberration root mean square plots of the vehicle-mounted lens in Example 2 with focal lengths of 22mm, 115mm, and 450mm are shown respectively.
[0032] Figures 11a-11c The images show distortion figures for the vehicle-mounted lens in Example 2 with focal lengths of 22mm, 115mm, and 450mm, respectively.
[0033] Figures 12a-12c The MTF curves are for the vehicle-mounted lens of Example 2 with focal lengths of 22mm, 115mm, and 450mm, respectively.
[0034] The attached icons are numbered as follows:
[0035] Detector 500; Aperture 600; First lens 10; First arc surface S11; Second arc surface S12; Second lens 20; Third arc surface S21; Fourth arc surface S22; Third lens 30; Fifth arc surface S31; Sixth arc surface S32; Fourth lens 40; Seventh arc surface S41; Eighth arc surface S42; Fifth lens 50; Ninth arc surface S51; Tenth arc surface S52; Sixth lens 60; Eleventh arc surface S61; Twelfth arc surface S62; Seventh lens 70; Thirteenth arc surface S71; Fourteenth arc surface S72; Eighth lens 80; Fifteenth arc surface S81; Sixteenth arc surface S82. Detailed Implementation
[0036] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.
[0037] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.
[0038] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.
[0039] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0040] Figure 1 A schematic diagram of the optical system of a vehicle-mounted lens with a focal length of 22 mm, provided in some embodiments of this application; Figure 2 for Figure 1 A schematic diagram of light propagation from a vehicle-mounted camera. Figure 3 A schematic diagram of light propagation in an optical system for a vehicle-mounted lens with a focal length of 115 mm, provided in some embodiments of this application; Figure 4 This is a schematic diagram illustrating light propagation in an optical system for a vehicle-mounted lens with a focal length of 450mm, provided in some embodiments of this application. Please refer to the following... Figures 1-4This application provides a vehicle-mounted lens, which, from the object side to the image side, comprises: a first lens 10 with positive optical power, a second lens 20 with negative optical power, a third lens 30 with negative optical power, a fourth lens 40 with negative optical power, a fifth lens 50 with positive optical power, a sixth lens 60 with positive optical power, a seventh lens 70 with negative optical power, and an eighth lens 80 with negative optical power. The vehicle-mounted lens is configured to perform staged zooming between focal lengths of 22 mm, 115 mm, and 450 mm. The second lens 20, third lens 30, and fourth lens 40 are configured to move simultaneously along the optical axis during zooming. The fifth lens 50 and sixth lens 60 are configured to move simultaneously along the optical axis during zooming. The first lens 10, seventh lens 70, and eighth lens 80 are configured to remain in their original positions during zooming. At least two lenses in the vehicle-mounted lens are aspherical lenses.
[0041] In this embodiment, the vehicle-mounted lens can be a CCD (Charge-coupled Device) camera lens, which is used in the vehicle-mounted infrared detection system. The CCD camera lens transmits real-time images of targets outside the vehicle to the photoelectric receiver CCD photosensitive chip. The system processes the real-time images of targets outside the vehicle and provides them to the vehicle system and the driver.
[0042] The vehicle-mounted lens may also include a detector 500, located on the side of the eighth lens 80 opposite to the seventh lens 70 and spaced apart from it. During zooming, the first lens 10, the seventh lens 70, the eighth lens 80, and the detector 500 remain stationary. The first lens 10 images the observed target onto the object-side surface of the second lens 20. The second lens 20, the third lens 30, and the fourth lens 40 move together along the optical axis to change the focal length and magnification during the movement. The fifth lens 50 and the sixth lens 60 move together along the optical axis to pull the image plane back, so that an image can ultimately be formed on the target surface of the detector 500. The seventh lens 70 and the eighth lens 80 are used to project the image formed by the fifth lens 50 and the sixth lens 60 onto the target surface of the detector 500, which can shorten the overall lens length and compensate for aberrations.
[0043] The vehicle-mounted lens in this embodiment is a long-wavelength, staged zoom lens. It employs a staged zoom method, magnifying or reducing the size of targets outside the vehicle as needed while keeping the detection location constant, achieving a wide-range search and detailed examination of these targets. When the focal length is short, the field of view is large, allowing for a wide search of targets. When the focal length changes to medium or long, the focal length becomes very long, resulting in high magnification, enabling detailed examination of targets outside the vehicle. The vehicle-mounted lens in this embodiment has a short focal length of 22mm, a medium focal length of 115mm, and a long focal length of 450mm.
[0044] Furthermore, traditional zoom optical systems typically employ continuous zoom, requiring the design of complex nonlinear zoom curves and the machining of intricate nonlinear zoom cam grooves. During zooming, image quality fluctuates due to variations in the machining precision of the nonlinear zoom cam groove. In contrast, the automotive lens of this embodiment performs staged zooming between 22mm (short focal length), 115mm (medium focal length), and 450mm (telephoto), eliminating the need for a zoom curve design. This staged zoom method avoids the need for complex nonlinear zoom curves and the machining of intricate nonlinear zoom cam grooves, and also prevents image quality from changing due to machining errors in the nonlinear zoom cam groove during zooming.
[0045] In some embodiments, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60, the seventh lens 70, and the eighth lens 80 are all aspherical lenses.
[0046] The first lens 10 is a spherical lens. Since the aperture of the first lens 10 increases when it changes from a short focal length to a medium or long focal length, especially when the aperture of the first lens 10 at a long focal length is very large, it increases the difficulty of aspherical processing. Therefore, the first lens 10 in this embodiment is designed as a spherical lens, which can reduce the processing difficulty.
[0047] In the above approach, aspherical lenses have a better radius of curvature, which can maintain good aberration correction to achieve the desired performance. The application of aspherical lenses brings excellent sharpness and higher resolution, while also enabling lens miniaturization.
[0048] In some embodiments, the vehicle-mounted lens further includes an aperture stop 600, which is disposed on the object-side surface of the fifth lens 50. The aperture stop 600 has the function of adjusting the intensity of the transmitted light beam, which not only makes the shape of the vehicle-mounted lens more uniform and aesthetically pleasing, thus achieving the best lens shape, but also corrects aberrations. Furthermore, placing the aperture stop 600 on the object-side surface of the fifth lens 50 provides the best aberration correction effect.
[0049] In some embodiments, the vehicle-mounted lens further includes a lens barrel, in which a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70, and an eighth lens 80 are located. A straight groove is provided on the inner wall surface of the lens barrel. The second lens 20, the third lens 30, and the fourth lens 40 are slidably connected to the straight groove as a whole, and the fifth lens 50 and the sixth lens 60 are slidably connected to the straight groove as a whole.
[0050] In the above scheme, the second lens 20, the third lens 30, and the fourth lens 40 are slidably connected to the straight groove as a lens group, and the fifth lens 50 and the sixth lens 60 are slidably connected to the straight groove as a lens group. Compared with the traditional zoom lens which requires the design and processing of a complex nonlinear zoom cam groove, this embodiment does not require the design of a zoom curve. A straight groove is directly used when processing the cam groove. The staged zoom method of this application embodiment avoids the design of a complex nonlinear zoom curve and the processing of a complex nonlinear zoom cam groove. It also avoids the image quality from changing with the processing error of the nonlinear zoom cam groove during the zoom process.
[0051] In some embodiments, the angle between the principal ray and the optical axis in each field of view during zooming of the vehicle-mounted lens is less than 6.5°.
[0052] Traditional zoom systems do not consider the matching requirements with the detector's Chief Ray Angle (CRA). For zoom automotive lenses, as the focal length changes, the aperture stop position (60°) also changes, resulting in a large CRA between the chief ray and the optical axis in each field of view. This CRA exceeds the CRA angle required by the CCD sensor. Increased CRA angles in each field of view prevent light from reaching the sensor at the edges, causing vignetting, reduced energy, and uneven energy distribution on the image plane. However, the automotive lens in this application considers the matching requirements with the detector's Chief Ray Angle (CRA). During phased zooming, the angle between the chief ray and the optical axis in each field of view is less than 6.5°, which is less than the CRA value required by the CCD sensor manufacturer, preventing vignetting, reduced energy, and uneven energy distribution on the image plane.
[0053] In some embodiments, the first lens 10, the third lens 30, the fourth lens 40, the fifth lens 50, the sixth lens 60 and the eighth lens 80 are all germanium lenses, and the second lens 20 and the seventh lens 70 are zinc selenide lenses.
[0054] The lenses in this embodiment are all made of infrared-transmitting materials, and the corresponding detector is an infrared detector. The vehicle-mounted lens in this embodiment is a vehicle-mounted long-wave infrared stage zoom lens, suitable for searching and inspecting vehicles, obstacles, and pedestrians outside the vehicle at night or in poor lighting conditions, thus avoiding traffic accidents. Germanium lenses, in particular, have high hardness, good thermal conductivity, and are insoluble in water, exhibiting excellent infrared light transmission performance and low cost. This not only improves the infrared transmission effect of the vehicle-mounted lens but also reduces costs. Using as many germanium lenses as possible enhances the infrared transmission effect of the vehicle-mounted lens and reduces costs. Furthermore, the combination of germanium and zinc selenide lenses allows for the transmission of long-wave infrared beams of different wavelengths, effectively correcting aberrations and further improving the transmission effect of the infrared beam.
[0055] In some embodiments, the first lens 10 includes a first arc surface S11 and a second arc surface S12 arranged sequentially along the optical axis, and both the first arc surface S11 and the second arc surface S12 are convex surfaces relative to the light incident side.
[0056] The second lens 20 includes a third arc surface S21 and a fourth arc surface S22 arranged sequentially along the optical axis. Both the third arc surface S21 and the fourth arc surface S22 are convex surfaces relative to the incident side of the light.
[0057] The third lens 30 includes a fifth arc surface S31 and a sixth arc surface S32 arranged sequentially along the optical axis. Both the fifth arc surface S31 and the sixth arc surface S32 are convex surfaces relative to the incident side of the light.
[0058] The fourth lens 40 includes a seventh arc surface S41 and an eighth arc surface S42 arranged sequentially along the optical axis. The seventh arc surface S41 is concave on the side where the light is incident, and the eighth arc surface S42 is convex on the side where the light is incident.
[0059] The fifth lens 50 includes a ninth arc surface S51 and a tenth arc surface S52 arranged sequentially along the optical axis. Both the ninth arc surface S51 and the tenth arc surface S52 are convex surfaces relative to the incident side of the light.
[0060] The sixth lens 60 includes an eleventh arc surface S61 and a twelfth arc surface S62 arranged sequentially along the optical axis. The eleventh arc surface S61 is convex relative to the incident side of the light, and the twelfth arc surface S62 is concave relative to the incident side of the light.
[0061] The seventh lens 70 includes a thirteenth arc surface S71 and a fourteenth arc surface S72 arranged sequentially along the optical axis. Both the thirteenth arc surface S71 and the fourteenth arc surface S72 are concave on the side opposite to the incident light.
[0062] The eighth lens 80 includes a fifteenth arc surface S81 and a sixteenth arc surface S82 arranged sequentially along the optical axis. Both the fifteenth arc surface S81 and the sixteenth arc surface S82 are concave on the side opposite to the incident light.
[0063] It should be noted that a convex surface relative to the side where light is incident refers to a surface that bulges away from the side where light is incident, while a concave surface relative to the side where light is incident refers to a surface that is recessed towards the side where light is incident. For example... Figure 1 The left side of the first lens 10 to the eighth lens 80 is the light incident side.
[0064] In some embodiments, the fourth arc surface S22, the sixth arc surface S32, the eighth arc surface S42, the ninth arc surface S51, the eleventh arc surface S61, the thirteenth arc surface S71, and the fifteenth arc surface S81 are all aspherical surfaces, which can satisfy aberration correction, facilitate processing, and reduce costs.
[0065] A second aspect of this application provides a vehicle-mounted camera system, including a vehicle-mounted lens according to any of the above embodiments. Since this vehicle-mounted camera system employs all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.
[0066] Example
[0067] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0068] Example 1
[0069] The vehicle-mounted lens of Embodiment 1 includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 50, a sixth lens 60, a seventh lens 70, and an eighth lens 80 arranged sequentially along the light incident path. An aperture stop 600 is located on the object-side surface of the fifth lens 50. The second lens 20, third lens 30, fourth lens 40, fifth lens 50, sixth lens 60, seventh lens 70, and eighth lens 80 are aspherical lenses. The surface shape of each aspherical surface is represented by an even-order aspherical surface, which is described by adding a polynomial increment to a sphere (or an aspherical surface defined by a quadratic surface). The even-order aspherical surface is described by an even power of the radial coordinate value, and the standard base plane is determined by the radius of curvature and the quadratic surface coefficient. The surface shape coordinates are determined by the following formula:
[0070]
[0071] in, Radial radius Here, k represents the higher-order aspherical coefficients, and k represents the quadratic surface coefficients. Let be the curvature, and R be the radius of curvature.
[0072] The specific parameters of the vehicle-mounted camera in Example 1 are shown in Table 1.
[0073]
[0074] In Table 1 above, the sign of the radius of curvature is relative to the light-emitting side, with the origin being the convex side (positive) and the concave side (negative). AIR represents air, that is, the air medium between the lenses; GERMANIUM represents germanium glass; and ZNSE represents zinc selenide.
[0075] Other aspherical coefficients for even-order aspherical surfaces are shown in Table 2 below:
[0076]
[0077] The vehicle-mounted lens of Example 1 has a short focal length of 22mm, a medium focal length of 115mm, and a telephoto focal length of 450mm. The angle of reference (CRA) between the principal ray and the optical axis in each field of view is shown in Tables 3-5. As can be seen from Tables 3-5, the CRA between the principal ray and the optical axis in each field of view of the vehicle-mounted lens of Example 1 is less than 6.5° during zooming, which is much smaller than the CRA value required by the CCD detector image sensor chip manufacturer, and thus meets the requirements and will not cause vignetting.
[0078] Table 3. CRA of the vehicle-mounted lens with a focal length of 22mm in Example 1
[0079]
[0080] Table 4. CRA of the vehicle-mounted lens with a focal length of 115mm in Example 1
[0081]
[0082] Table 5. CRA of the vehicle-mounted lens with a focal length of 450mm in Example 1
[0083]
[0084] like Figures 5a-5c As shown in the dot plot, the light rays emitted from the object point in each field of view, under different temperatures, result in a blur pattern on the image plane that is almost entirely within the Airy disk, except for telephoto lenses. The Airy disk represents the optimal state achievable by an ideal optical system. At telephoto lenses, the relative aperture increases, and the blur pattern slightly enlarges, but the image quality remains excellent. Figures 6a-6c As shown in the root mean square wavefront aberration, the wavefront aberration of the system is less than 0.1 wavelength under different focal lengths. Generally, a wavefront aberration less than 1 / 4 wavelength is considered to indicate very good imaging quality. Figures 7a-7c As shown in the distortion curve, the system exhibits significant distortion at short focal lengths due to the short focal length and very large field of view. However, as the focal length increases, the distortion decreases rapidly, reducing to 1.2% at medium focal lengths and 0.2% at long focal lengths, which fully meets the requirements.
[0085] For automotive lenses, the most important image quality metric is MTF (Mean Transmission Frequency), such as... Figures 8a-8c In this embodiment, at a sampling frequency of 16 line pairs / mm, the MTF values at short and medium focal lengths are mostly greater than 0.4 and 0.3, respectively. At a sampling frequency of 16 line pairs / mm, the MTF values at long focal lengths are mostly greater than 0.26. This indicates that the imaging quality of this embodiment is sufficient to meet the imaging quality requirements.
[0086] Example 2
[0087] The difference between Example 2 and Example 1 lies in the specific parameters of the vehicle-mounted camera, as shown in Table 6 below:
[0088]
[0089] Other aspherical coefficients for even-order aspherical surfaces are shown in Table 7 below:
[0090]
[0091] like Figures 9a-9c As shown in the dot plot, the light rays emitted from the object point in each field of view, under different focal lengths, produce a blur pattern on the image plane that is almost entirely within the Airy disk. The Airy disk represents the optimal state achievable by an ideal optical system. At longer focal lengths, the relative aperture increases, and the blur pattern slightly enlarges, but the image quality remains excellent. Figures 10a-10c As shown by the root mean square wavefront aberration, the wavefront aberration of the system under different temperatures is less than 0.18 wavelengths. Generally, a wavefront aberration less than 1 / 4 wavelength is considered to indicate very good imaging quality. Figures 11a-11c As shown in the distortion curve, the system exhibits significant distortion at short focal lengths due to the short focal length and very large field of view. However, the distortion decreases rapidly with increasing focal length, reducing to 0.85% at medium focal lengths and 0.3% at long focal lengths, which fully meets the requirements.
[0092] like Figures 12a-12c In this embodiment, at a sampling frequency of 16 line pairs / mm at both short and medium focal lengths, the MTF value is generally greater than 0.3, and at a sampling frequency of 16 line pairs / mm at the telephoto focal length, the MTF value is generally greater than 0.22. This indicates that the imaging quality of this embodiment meets the imaging quality requirements.
[0093] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A vehicle-mounted lens, characterized in that, The vehicle-mounted lens, from the object side to the image side, comprises, in sequence: a first lens with positive optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with positive optical power, a seventh lens with negative optical power, and an eighth lens with negative optical power. The vehicle-mounted lens is configured to perform staged zoom between focal lengths of 22 mm, 115 mm, and 450 mm. The short focal length of the vehicle-mounted lens is 22 mm, the medium focal length is 115 mm, and the long focal length is 450 mm. The second, third, and fourth lenses are configured to move simultaneously along the optical axis during zooming, and the fifth and sixth lenses are configured to move simultaneously along the optical axis during zooming. The first, seventh, and eighth lenses are configured to remain in their original positions during zooming. At least two lenses in the vehicle-mounted lens are aspherical lenses.
2. The vehicle-mounted lens according to claim 1, characterized in that, The second, third, fourth, fifth, sixth, seventh, and eighth lenses are all aspherical lenses.
3. The vehicle-mounted lens according to claim 1, characterized in that, The vehicle-mounted lens also includes an aperture stop, which is disposed on the object side of the fifth lens.
4. The vehicle-mounted lens according to claim 1, characterized in that, The vehicle-mounted lens also includes a lens barrel, in which the second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens and eighth lens are located. The inner wall of the lens barrel is provided with a straight groove. The second lens, third lens and fourth lens are slidably connected to the straight groove as a whole, and the fifth lens and sixth lens are slidably connected to the straight groove as a whole.
5. The vehicle-mounted lens according to claim 1, characterized in that, During zooming, the angle between the principal ray and the optical axis of the vehicle-mounted lens in each field of view is less than 6.5°.
6. The vehicle-mounted lens according to claim 1, characterized in that, The first, third, fourth, fifth, sixth, and eighth lenses are all germanium lenses, while the second and seventh lenses are zinc selenide lenses.
7. The vehicle-mounted lens according to any one of claims 1-6, characterized in that, The first lens includes a first arc surface and a second arc surface arranged sequentially along the optical axis, and both the first arc surface and the second arc surface are convex surfaces relative to the incident side of the light. The second lens includes a third arc surface and a fourth arc surface arranged sequentially along the optical axis, wherein both the third arc surface and the fourth arc surface are convex surfaces relative to the incident side of the light. The third lens includes a fifth arc surface and a sixth arc surface arranged sequentially along the optical axis, and both the fifth arc surface and the sixth arc surface are convex surfaces relative to the incident side of the light. The fourth lens includes a seventh arc surface and an eighth arc surface arranged sequentially along the optical axis. The seventh arc surface is concave relative to the incident side of the light, and the eighth arc surface is convex relative to the incident side of the light. The fifth lens includes a ninth arc surface and a tenth arc surface arranged sequentially along the optical axis, and both the ninth arc surface and the tenth arc surface are convex surfaces relative to the incident side of the light rays; The sixth lens includes an eleventh arc surface and a twelfth arc surface arranged sequentially along the optical axis. The eleventh arc surface is convex relative to the light incident side, and the twelfth arc surface is concave relative to the light incident side. The seventh lens includes a thirteenth arc surface and a fourteenth arc surface arranged sequentially along the optical axis, and both the thirteenth arc surface and the fourteenth arc surface are concave surfaces relative to the incident side of the light. The eighth lens includes a fifteenth arc surface and a sixteenth arc surface arranged sequentially along the optical axis, both of which are concave relative to the incident side of the light.
8. The vehicle-mounted lens according to claim 7, characterized in that, The fourth, sixth, eighth, ninth, eleventh, thirteenth, and fifteenth arc surfaces are all aspherical surfaces.
9. A vehicle-mounted camera system, characterized in that, Including the vehicle-mounted camera as described in any one of claims 1-8.