A long and narrow wide-angle temperature measurement lens

Abstract

This invention discloses a narrow, wide-angle temperature measuring lens, belonging to the field of optical lens technology. It includes a first lens with negative optical power, a second lens with negative optical power, an aperture stop, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged sequentially along the optical axis. Among the eighth, ninth, tenth, and eleventh lenses, two lenses have positive optical power and two lenses have negative optical power. By rationally setting the ratio of the optical back focal length to the total optical length, and the range of the optical back focal length, a narrow, wide-angle temperature measuring lens with a small front diameter is formed. This facilitates invasive detection, ensures low cost while improving imaging quality, and achieves high and low temperature stability.

Description

Technical Field

[0001] This invention belongs to the field of optical lens technology, specifically relating to a narrow, wide-angle temperature measuring lens. Background Technology

[0002] In the fields of industrial high-temperature production and equipment condition monitoring, high-temperature temperature measuring lenses, as core components of optical temperature measuring equipment, directly determine the overall performance and scenario adaptability of the temperature measuring system through their temperature measurement accuracy and environmental adaptability. In recent years, the increased use of high-temperature temperature measuring lenses in industry has exposed their shortcomings in environmental interference resistance under visible light wavelengths. To address this, multispectral fusion temperature measurement technology has become a research hotspot in the industrial temperature measurement field. This technology, by fusing multi-band spectral temperature measurement data, can effectively avoid the problem of single visible light bands being susceptible to environmental interference, significantly suppressing temperature measurement errors caused by smoke, stray light, and thermal radiation, and solving the problems of low accuracy and weak anti-interference capability in traditional visible light temperature measurement. Furthermore, with the advancement of refined industrial monitoring, the demand for precise temperature measurement in special spaces such as narrow, enclosed cavities, the interiors of tubular equipment, and narrow high-temperature channels continues to grow, placing higher demands on the performance and size of high-temperature temperature measuring lenses. Existing multispectral fusion temperature measurement lenses are still generally large in size and have low image quality, making them unsuitable for narrow and long tubular temperature measurement scenarios. Furthermore, their temperature resistance is generally poor, and they are prone to problems such as thermal deformation of optical components when operating in high-temperature and narrow conditions for a long time, which is not conducive to ensuring stability and service life. In addition, the temperature measurement lens angle is usually small, resulting in incomplete shooting scenarios.

[0003] Therefore, there is an urgent need for a compact, high-temperature-resistance, wide-angle, long and narrow tubular temperature measurement optical system that combines high temperature measurement accuracy with strong environmental interference resistance. Summary of the Invention

[0004] The purpose of this invention is to address the above-mentioned problems by proposing a narrow and elongated wide-angle temperature measuring lens, which has a small diameter, a large field of view, a wide spectral response of 435nm-960nm, and an ultra-long back focal length. This facilitates the implementation of a narrow and elongated temperature measuring lens layout, has high resolution, maintains clear and sharp image imaging, and has low ghosting levels.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention proposes a narrow, wide-angle temperature measuring lens, comprising, sequentially arranged along the optical axis, a first lens with negative optical power, a second lens with negative optical power, an aperture stop, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens, wherein two of the eighth, ninth, tenth, and eleventh lenses have positive optical power and two lenses have negative optical power, and the following conditions are satisfied:

[0007]

[0008] 38≤ ≤46

[0009] in, The distance on the axis from the object surface of the first lens to the image plane; This represents the axial distance from the image-side surface of the eleventh lens to the image plane, in mm.

[0010] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0011]

[0012] in, The combined effective focal length of the first to sixth lenses. This is the combined effective focal length of lenses seven through eleven. The effective focal length of the seventh lens. The combined effective focal length of lenses 8 through 11 is given in mm.

[0013] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0014]

[0015] in, Let be the radius of curvature of the image-side surface of the second lens. The distance between the image-side surface of the second lens and the object-side surface of the third lens is on the axis, both in mm.

[0016] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0017]

[0018] in, This is the maximum effective half-aperture of the seventh lens. The effective focal length of the narrow, wide-angle temperature measuring lens is in mm.

[0019] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0020]

[0021] in, The maximum effective half-aperture of the first lens. This represents the maximum effective half-aperture of the eleventh lens, in mm.

[0022] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0023]

[0024] in, The distance between the image-side surface of the seventh lens and the object-side surface of the eighth lens is on the axis, both in mm.

[0025] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0026]

[0027] in, abv9 is the Abbe number of the eighth lens, abv10 is the Abbe number of the ninth lens, abv10 is the Abbe number of the tenth lens, and abv11 is the Abbe number of the eleventh lens.

[0028] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0029] ; or ;

[0030] in, This is the axial distance from the image-side surface of the seventh lens to the object-side surface of the eighth lens. The effective focal length of the narrow, wide-angle temperature measuring lens. denoted as the radius of curvature of the object-side surface of the second lens, both in mm.

[0031] Preferably, the narrow, wide-angle temperature measuring lens also meets the following conditions:

[0032] ; ;

[0033] ; ;

[0034] in, The effective focal length of the narrow, wide-angle temperature measuring lens. The effective focal length of the seventh lens. The combined effective focal length of the first to sixth lenses. The combined effective focal length of the ninth to tenth lenses is in mm.

[0035] Preferably, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the third lens is a concave-convex lens, the fourth lens is a biconvex lens, the fifth lens is a convex-concave lens, the sixth lens is a biconvex lens, the seventh lens is a concave-convex lens, the eighth lens is a convex-concave lens or a concave-convex lens, the ninth lens is a biconvex lens or a convex-concave lens, the tenth lens is a biconvex lens or a concave-convex lens, and the eleventh lens is a biconvex lens or a concave-convex lens.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] This narrow, wide-angle temperature measurement lens employs an eleven-lens architecture with a large back focal length, facilitating the placement of a beam splitter system (such as a prism). The six front lenses utilize a small-diameter design, allowing for assembly into the narrow lens barrel for invasive detection. Through a rational combination of positive and negative lenses and focal lengths, tolerance-sensitive lenses are cemented together, significantly reducing broad-spectrum chromatic and spherical aberrations and minimizing local sensitivity. This ensures minimal infrared defocus and low risk of short-wavelength purple fringing. The preferred all-glass lens architecture reduces costs while improving image quality and stability. Furthermore, the optimized materials and cementing schemes in the rear five lenses achieve passive, heat-free focusing with high and low temperature stability, ensuring back focal stability regardless of temperature changes and eliminating the need for additional focusing mechanisms, thus reducing structural complexity. By limiting the lens curvature radius, ghosting energy levels are minimized, resulting in high contrast. It is compatible with 1 / 2.8” chips, has a field of view (FOV) ≥ 120°, and a 90mm < With a diameter of less than 200mm, it can capture more effective information in confined spaces, meeting the high and low temperature range of -40 to +120℃. Its small size and good imaging quality meet the needs of continuous and accurate temperature measurement in high-temperature and narrow industrial spaces. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the narrow wide-angle temperature measuring lens in Embodiment 1 of the present invention;

[0039] Figure 2 The longitudinal spherical aberration diagram and field curvature diagram of the narrow wide-angle temperature measuring lens of Embodiment 1 of the present invention are shown.

[0040] Figure 3 This is a schematic diagram of the structure of the narrow wide-angle temperature measuring lens in Embodiment 2 of the present invention;

[0041] Figure 4 The longitudinal spherical aberration diagram and field curvature diagram of the narrow wide-angle temperature measuring lens of Embodiment 2 of the present invention are shown.

[0042] Figure 5This is a schematic diagram of the structure of the narrow wide-angle temperature measuring lens in Embodiment 3 of the present invention;

[0043] Figure 6 The longitudinal spherical aberration diagram and field curvature diagram of the narrow wide-angle temperature measuring lens of Embodiment 3 of the present invention;

[0044] Figure 7 This is a schematic diagram of the structure of the narrow wide-angle temperature measuring lens in Embodiment 4 of the present invention;

[0045] Figure 8 The diagram shows the longitudinal spherical aberration and field curvature of the narrow wide-angle temperature measuring lens in Embodiment 4 of the present invention.

[0046] Explanation of reference numerals in the attached diagram: L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; L8, eighth lens; L9, ninth lens; L10, tenth lens; L11, eleventh lens; STO, aperture stop; J1, first prism; J2, second prism; CG, protective glass; IMA, image plane. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may be an intervening component. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application.

[0049] like Figures 1-8 As shown, a narrow, wide-angle temperature measuring lens includes, sequentially arranged along the optical axis, a first lens L1 with negative optical power, a second lens L2 with negative optical power, an aperture stop STO, a third lens L3 with positive optical power, a fourth lens L4 with positive optical power, a fifth lens L5 with negative optical power, a sixth lens L6 with positive optical power, a seventh lens L7 with positive optical power, an eighth lens L8, a ninth lens L9, a tenth lens L10, and an eleventh lens L11. Among the eighth lens L8, ninth lens L9, tenth lens L10, and eleventh lens L11, two lenses have positive optical power and two lenses have negative optical power, satisfying the following condition:

[0050]

[0051] 38≤ ≤46

[0052] in, The distance from the object surface of the first lens L1 to the image surface is on the axis. , where L11 is the axial distance from the image-side surface to the image plane, in mm.

[0053] The first lens L1 has negative optical power and a convex-concave shape, providing excellent ability to quickly compress wide-angle light rays and reduce the incident angle of the second lens L2. The second lens L2, also with negative optical power, further compresses the light beam height, fully utilizing the two negative optical power lenses (first lens L1 and second lens L2) to reduce the light beam height, thereby reducing the lens diameter and enhancing miniaturization. An aperture stop STO is positioned between the second lens L2 and the third lens L3, close to the object side. This, combined with the optical power distribution of the first lens L1 and the second lens L2, helps maintain a small size. Features: The third lens L3 has positive optical power, which helps diffuse light, forming a positive and negative lens combination scheme and optimizing spherical aberration; the fourth lens L4, which also has positive optical power, can further reduce the axial and transverse chromatic aberration of the front group lenses (first lens L1 to sixth lens L6) through the use of high Abbe number materials; the fifth lens L5, which has negative optical power, and the sixth lens L6, which has positive optical power, combine to form a cemented doublet lens, further correcting chromatic aberration, while using cementation to smooth the light and reasonably reduce the sensitivity to eccentricity tolerance, improving assembly tolerance; between the sixth lens L6 and the seventh lens L7 For the intermediate image plane, a segmented imaging scheme is used to expand the optical back focal length, while an aberration compensation scheme is allocated to improve the compensation effect. The seventh lens L7, with positive optical power, receives the subsequent light rays from the intermediate image of the intermediate image plane. By setting a high refractive index, the surface concavity and convexity tendency and the light ray height are reduced, further limiting the effective diameter of the lens. The eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 all have positive or negative optical power. The four lenses are arranged with two lenses with positive optical power and two lenses with negative optical power, preferably in an alternating positive and negative arrangement. This design achieves a better chromatic aberration compensation configuration, which helps optimize spherical aberration field curvature. Furthermore, it allows for the reasonable implementation of double-cemented and triple-cemented schemes, further enhancing aberration correction capabilities and reducing tolerance sensitivity. Additionally, the appropriate material combinations allow for a passive high / low temperature compensation optical scheme that does not affect resolution, improving the environmental adaptability of the elongated wide-angle temperature measuring lens under ultra-long optical back focal lengths. The eleventh lens, L11, emits smooth light with a small incident angle at the image plane. When a prism is placed between the eleventh lens L11 and the image plane, the angle at which light enters the rear prism is small, which helps improve the prism's beam splitting effect. Through these settings, the elongated wide-angle temperature measuring lens (hereinafter referred to as the temperature measuring lens) does not require vignetting, exhibits high image plane uniformity and good resolution, and the lens can be installed in a elongated tubular lens barrel, facilitating deep penetration into industrial equipment for detection.

[0054] Specifically, The possible values ​​are: 0.46, 0.41, 0.40, and 0.47. Meeting the above conditions, the temperature measuring lens has a long optical back focus (FBL). By setting a long optical back focus, a prism can be installed at the rear to split the light paths of different wavelengths, further enabling multispectral fusion of a single temperature measuring lens. If the upper limit is exceeded, the optical back focus FBL becomes too large, which is detrimental to overall aberration compensation; if the lower limit is exceeded, the optical back focus FBL becomes too small, insufficient for arranging structural components such as prisms, attenuators, and filters.

[0055] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0056]

[0057] in, The combined effective focal length of lenses L1 through L6 is [missing information]. The combined effective focal length of lenses L7 (seventh lens) to L11 (eleventh lens) The effective focal length of the seventh lens. The combined effective focal length of lenses 8 through 11 is given in mm.

[0058] Specifically, The possible values ​​are: 9.96, 9.95, 10.08, and 10.06. The temperature-measuring lens is divided into two subsystems from the center image plane. The first subsystem consists of lenses L1, L2, L3, L4, L5, and L6; the second subsystem consists of lenses L7, L8, L9, L10, and L11. Satisfying the above conditions, the optical power distribution between the first and second subsystems is reasonable. The optical power of the first subsystem is approximately 1 / 10 that of the second subsystem. The first subsystem is equivalent to a short focal length ultra-wide-angle lens, which can effectively compress the light beam height. The first subsystem reduces the effective diameter of the lens, while the second subsystem is equivalent to a telephoto finite-distance lens. It fully utilizes the advantage of the flatness of the telephoto light and can obtain a larger optical back focal length (FBL) to meet the requirements of the beam splitting system. If the lower limit is exceeded, the optical power ratio of the first subsystem increases and the light aperture becomes larger, which is not conducive to maintaining the small effective aperture characteristics of the first lens L1 to the sixth lens L6. If the upper limit is exceeded, the optical power ratio of the first subsystem is too small and the optical power ratio of the second subsystem is too large, which can easily lead to an increase in the aperture of the seventh lens L7 to the eleventh lens L11, which is not conducive to overall miniaturization.

[0059] The values ​​can be: 0.82, 1.28, 1.5, and 1.02. Meeting the above conditions, the ratio of the focal length of the seventh lens L7 and the combined effective focal length of the eighth lens L8 to the eleventh lens L11 within the second subsystem is within a reasonable range. The focal length of the seventh lens L7 is positive, and the combined effective focal length of the eighth lens L8 to the eleventh lens L11 is positive. This reasonable ratio ensures even distribution of optical power, avoiding excessive concentration of optical power in either the seventh lens L7 or the eighth lens L8 to the eleventh lens L11. This helps reduce tolerance sensitivity. Furthermore, the optimal combination of optical power from the eighth lens L8 to the eleventh lens L11 facilitates the design of double-cemented or triple-cemented schemes, further improving chromatic aberration correction and reducing tolerance sensitivity. If this range is exceeded, the ratio of the focal length of the seventh lens L7 to the combined effective focal length of the eighth lens L8 to the eleventh lens L11 will be abnormal. The optical power will tend to concentrate on the seventh lens L7 or the eighth lens L8 to the eleventh lens L11, resulting in abnormal fluctuations in light height. In particular, the light height of the seventh lens L7 is likely to be significantly higher than that of the four lenses from the eighth lens L8 to the eleventh lens L11, which will cause abnormal sensitivity to eccentricity and tilt tolerance, which is not conducive to improving assembly yield and reducing costs.

[0060] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0061]

[0062] in, Let be the radius of curvature of the image-side surface of the second lens L2. The distance is the axial distance from the image side of the second lens L2 to the object side of the third lens L3, both in mm.

[0063] Specifically, The possible values ​​are: 12.45, 59.55, 16.92, and 26.82. The aperture stop STO is positioned between the second lens L2 and the third lens L3. The STO location receives dense full-field rays, which are energy-intensive and prone to ghosting. To satisfy the above conditions, the radius of curvature of the image-side surface of the second lens L2 and the axial distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3 must maintain a reasonable ratio. This constraint increases the distance between the second lens L2 and the third lens L3, and also limits the distance between the second lens L2 and the aperture stop STO, keeping the second lens L2 away from the area of ​​dense light and simultaneously limiting the radius of curvature of the image-side surface of the second lens L2. This causes light to scatter at different angles, reducing the radius of curvature of the image side of the second lens L2. The planar reflection ghost image of the rear prism, attenuator, filter and other structural components; beyond this range, it is difficult to limit the radius of curvature of the image side surface of the second lens L2. 2. The axial distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3 This can easily lead to high ghosting energy levels, affecting image quality.

[0064] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0065]

[0066] in, This is the maximum effective half-aperture of the seventh lens, L7. The effective focal length of the narrow, wide-angle temperature measuring lens is in mm.

[0067] Specifically, The possible values ​​are: -2.31, -2.22, -2.39, and -2.15. Satisfying the above conditions limits the effective aperture of the seventh lens L7 to a reasonable range. As the position with the largest light aperture of the temperature measuring lens, the seventh lens L7 limits the overall lens aperture, thus ensuring the advantage of the small aperture and facilitating its installation in a narrow, elongated lens barrel. Exceeding the upper limit results in excessive compression of the seventh lens L7, making it difficult to compensate for spherical aberration and field curvature, thus reducing resolution. Exceeding the lower limit results in insufficient limitation of the maximum effective half-aperture of the seventh lens L7; an excessively large maximum effective half-aperture negates the advantage of a small aperture and is insufficient to solve the existing technical problems.

[0068] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0069]

[0070] in, The maximum effective half-aperture of the first lens L1, This refers to the maximum effective half-aperture of the eleventh lens, L11, in mm.

[0071] Specifically, The possible values ​​are: 0.37, 0.5, 0.48, and 0.42. Meeting the above conditions, the ratio of the maximum effective half-aperture of the first lens L1 to the maximum effective half-aperture of the eleventh lens L11 is appropriate. This indicates that the maximum effective half-aperture of the first lens L1 is significantly smaller than that of the eleventh lens L11. Depending on the lens installation and positioning method, the lens size of the first subsystem will be larger than the effective aperture of the first lens L1, but will generally not exceed the effective aperture of the second subsystem. This maintains an overall layout scheme with a small object-side aperture at the front end and a large image-side aperture at the rear end, thus achieving a narrow and elongated layout that meets the reasonable requirements of industrial detection. Exceeding the upper limit, the maximum effective half-aperture of the first lens L1 becomes too large, making it difficult to achieve the characteristic of a small front-end diameter; exceeding the lower limit, the maximum effective half-aperture of the first lens L1 becomes too small, making lens processing and assembly difficult.

[0072] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0073]

[0074] in, The distance between the image-side surface of the seventh lens L7 and the object-side surface of the eighth lens L8 is on the axis, in mm.

[0075] Specifically, The possible values ​​are 13.05, 7.45, 5.7, and 14.18. These satisfy the above conditions, ensuring the on-axis air gap between the seventh lens L7 and the eighth lens L8 remains within a reasonable range. The total length and optical back focal length of the temperature-measuring lens are adjusted by dividing the lens into left and right sides using an aperture stop. Adjusting and further limiting the light beam height, lens aperture, and light beam pattern to a reasonable range can help reduce the tolerance sensitivity and manufacturing / assembly difficulty of the temperature measuring lens. Exceeding the upper limit results in small on-axis air gaps for the seventh lens (L7) and eighth lens (L8), easily leading to an increase in their apertures and diminishing the advantage of the small diameter of the temperature measuring lens. Exceeding the lower limit results in large on-axis air gaps for the seventh lens (L7) and eighth lens (L8), causing flattened light beams that cannot effectively balance aberrations and achieve good resolution.

[0076] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0077]

[0078] in, abv9 is the Abbe number of the eighth lens L8, abv10 is the Abbe number of the ninth lens L9, abv10 is the Abbe number of the tenth lens L10, and abv11 is the Abbe number of the eleventh lens L11.

[0079] Specifically, The possible values ​​are: 164.8, 194.4, 187.6, and 186.1. Meeting the above conditions ensures that the Abbe numbers of the eighth lens L8, ninth lens L9, tenth lens L10, and eleventh lens L11 are within a reasonable range. This allows the use of a combination of materials with higher and lower Abbe numbers for the four lenses, such as HZPK, HFK, and HZF series materials. This fully utilizes the anomalous dispersion characteristics of the materials, combining positive and negative combinations with cemented composites to quickly reduce on-axis chromatic aberration and spherical aberration in telephoto lenses. Simultaneously, it compensates for broad-spectrum chromatic aberration from 435nm to 940nm, achieving low infrared defocus and excellent purple fringing performance. Furthermore, the appropriate selection of high Abbe materials can further compensate for temperature drift of the ultra-long optical back focal length (FBL) at high and low temperatures, achieving passive compensation and reducing structural design complexity. Beyond this range, the Abbe numbers of the eighth lens L8, the ninth lens L9, the tenth lens L10, and the eleventh lens L11 are far from achieving a reasonable allocation for the temperature measurement lens. This can easily lead to difficulties in compensating for chromatic aberration and spherical aberration across the wide spectrum, increasing design complexity, reducing aberration compensation effects, and affecting overall image quality.

[0080] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0081] ; or ;

[0082] in, This is the axial distance from the image-side surface of the seventh lens L7 to the object-side surface of the eighth lens L8. The effective focal length of the narrow, wide-angle temperature measuring lens. denoted as the radius of curvature of the object-side surface of the second lens L2, both in mm.

[0083] In one embodiment, the elongated wide-angle temperature measuring lens also satisfies the following condition:

[0084] ; ;

[0085] ; ;

[0086] in, The effective focal length of the narrow, wide-angle temperature measuring lens. The effective focal length of the seventh lens L7. The combined effective focal length of lenses L1 through L6 is [missing information]. The combined effective focal length of lenses L9 to L10 is in mm.

[0087] In one embodiment, the first lens L1 is a convex-concave lens, the second lens L2 is a convex-concave lens, the third lens L3 is a concave-convex lens, the fourth lens L4 is a biconvex lens, the fifth lens L5 is a convex-concave lens, the sixth lens L6 is a biconvex lens, the seventh lens L7 is a concave-convex lens, the eighth lens L8 is a convex-concave lens or a concave-convex lens, the ninth lens L9 is a biconvex lens or a convex-concave lens, the tenth lens L10 is a biconvex lens or a concave-convex lens, and the eleventh lens L11 is a biconvex lens or a concave-convex lens.

[0088] For ease of understanding, the following detailed embodiments are provided. The reference wavelength for the effective focal length, Abbe number, and refractive index in each embodiment is 546 nm.

[0089] Example 1:

[0090] like Figure 1 As shown, in this embodiment, a narrow wide-angle temperature measuring lens includes a first lens L1, a second lens L2, an aperture STO, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a first prism J1, a second prism J2, and a protective glass CG, arranged sequentially along the optical axis (from the object plane S0 to the image plane IMA). The fifth lens L5 and the sixth lens L6 form a cemented doublet, and the ninth lens L9 and the tenth lens L10 also form a cemented doublet. The first prism J1 and the second prism J2 are beam-splitting prisms, enabling optical path refraction. This temperature measuring lens has an effective focal length of f = -2.93 mm and an aperture number Fno = 4.2, indicating that it achieves long back focal length, narrow shape, miniaturization, and multispectral characteristics.

[0091] Specifically, the optical parameters of this embodiment are shown in Table 1 below:

[0092] Table 1

[0093]

[0094] As shown in Table 1, surface number S0 represents the object surface, and surface numbers S1, S3, S5, S7, S9, S10, S12, S14, S16, S17, S19, S21, S23, and S25 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. S2, S4, S6, S8, S10, S11, S13, S15, S17, S18, S20, S22, S24, and S26 represent the image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop.

[0095] Figure 2 The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) includes the temperature-sensing lens, which shows the deviation of the convergence focal point after light of different wavelengths passes through the temperature-sensing lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, in this embodiment, the deviation of the convergence focal point for each wavelength of light tends to be consistent and is all within 0.1 mm, effectively suppressing blur spots or color halos in the image. Figure 2 The data also includes astigmatic field curves of the temperature measuring lens, where the X-curve represents the sagittal field curve at 546 nm and the Y-curve represents the meridional field curve at 546 nm. As shown in the figures, the field curvature of the temperature measuring lens is within 0.05 mm, and both field curvature and astigmatism in each field of view are well corrected, with clear imaging at both the center and edges of the field of view. In summary, the temperature measuring lens exhibits good control over longitudinal spherical aberration and field curvature, possesses excellent imaging quality, and has a field of view (FOV) ≥ 130°.

[0096] Example 2:

[0097] like Figure 3As shown, in this embodiment, a narrow wide-angle temperature measuring lens includes a first lens L1, a second lens L2, an aperture STO, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a first prism J1, a second prism J2, and a protective glass CG, arranged sequentially along the optical axis (from the object plane S0 to the image plane IMA). The fifth lens L5 and the sixth lens L6 form a cemented doublet, the eighth lens L8 and the ninth lens L9 form a cemented doublet, and the tenth lens L10 and the eleventh lens L11 form a cemented doublet. This temperature measuring lens has an effective focal length of f = -2.85mm and an aperture number Fno = 5.0, indicating that it achieves long back focal length, narrow shape, miniaturization, and multispectral characteristics.

[0098] Specifically, the optical parameters of this embodiment are shown in Table 2 below:

[0099] Table 2

[0100]

[0101] As shown in Table 2, surface number S0 represents the object surface, and surface numbers S1, S3, S5, S7, S9, S10, S12, S14, S15, S17, S18, S20, S22, and S24 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. S2, S4, S6, S8, S10, S11, S13, S15, S16, S18, S19, S21, S23, and S25 represent the image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop.

[0102] Figure 4The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) including the temperature-measuring lens shows the deviation of the convergence point of light of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, the deviation of the convergence point of light of different wavelengths in this embodiment tends to be consistent and is all within 0.08 mm, effectively suppressing blur spots or color halos in the image. Figure 4 The data also includes astigmatic field curves of the temperature measuring lens, where the X-curve represents the sagittal field curve at 546 nm and the Y-curve represents the meridional field curve at 546 nm. As shown in the figures, the field curvature of the temperature measuring lens is within 0.025 mm, and both field curvature and astigmatism in each field of view are well corrected, with clear imaging at both the center and edges of the field of view. In summary, the temperature measuring lens exhibits good control over longitudinal spherical aberration and field curvature, possesses excellent imaging quality, and has a field of view (FOV) ≥ 130°.

[0103] Example 3:

[0104] like Figure 5 As shown, in this embodiment, a narrow wide-angle temperature measuring lens includes a first lens L1, a second lens L2, an aperture STO, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a first prism J1, a second prism J2, and a protective glass CG, arranged sequentially along the optical axis (from the object plane S0 to the image plane IMA). The fifth lens L5 and the sixth lens L6 form a cemented doublet lens, and the ninth lens L9, the tenth lens L10, and the eleventh lens L11 form a cemented triplicate lens. This temperature measuring lens has an effective focal length of f = -2.95mm and an aperture number Fno = 5.0, indicating that it achieves long back focal length, narrow shape, miniaturization, and multispectral characteristics.

[0105] Specifically, the optical parameters of this embodiment are shown in Table 3 below:

[0106] Table 3

[0107]

[0108] As shown in Table 3, surface number S0 represents the object surface, and surface numbers S1, S3, S5, S7, S9, S10, S12, S14, S16, S17, S18, S20, S22, and S24 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. S2, S4, S6, S8, S10, S11, S13, S15, S17, S18, S19, S21, S23, and S25 represent the image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop.

[0109] Figure 6 The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) including the temperature-measuring lens shows the deviation of the convergence point of light of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, the deviation of the convergence point of light of different wavelengths in this embodiment tends to be consistent and is all within 0.08 mm, effectively suppressing blur spots or color halos in the image. Figure 6 The data also includes astigmatic field curves of the temperature measuring lens, where the X-curve represents the sagittal field curve at 546 nm and the Y-curve represents the meridional field curve at 546 nm. As shown in the figures, the field curvature of the temperature measuring lens is within 0.025 mm, and both field curvature and astigmatism in each field of view are well corrected, with clear imaging at both the center and edges of the field of view. In summary, the temperature measuring lens exhibits good control over longitudinal spherical aberration and field curvature, possesses excellent imaging quality, and has a field of view (FOV) ≥ 130°.

[0110] Example 4:

[0111] like Figure 7As shown, in this embodiment, a narrow wide-angle temperature measuring lens includes a first lens L1, a second lens L2, an aperture STO, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a first prism J1, a second prism J2, and a protective glass CG, arranged sequentially along the optical axis (from the object plane S0 to the image plane IMA). The fifth lens L5 and the sixth lens L6 form a cemented doublet, and the tenth lens L10 and the eleventh lens L11 also form a cemented doublet. This temperature measuring lens has an effective focal length of f = -2.96 mm and an aperture number Fno = 4.6, indicating that it achieves long back focal length, narrow shape, miniaturization, and multispectral characteristics.

[0112] Specifically, the optical parameters of this embodiment are shown in Table 4 below:

[0113] Table 4

[0114]

[0115] As shown in Table 4, surface number S0 represents the object surface, and surface numbers S1, S3, S5, S7, S9, S10, S12, S14, S16, S18, S19, S21, S23, and S25 represent the object surface of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. S2, S4, S6, S8, S10, S11, S13, S15, S17, S19, S20, S22, S24, and S26 represent the image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the first prism J1, the second prism J2, and the protective glass CG, respectively. The cemented surface of the cemented lens assembly is considered as one surface. STO represents the aperture stop.

[0116] Figure 8The longitudinal spherical aberration diagram (LONGITUD INAL SPHERICAL ABER.) including the temperature-measuring lens shows the deviation of the convergence focal point of light of different wavelengths after passing through the lens. The vertical axis of the LONGITUD spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the image plane to the intersection of the ray and the optical axis. As shown in the LONGITUD spherical aberration diagram, the deviation of the convergence focal point of light of different wavelengths in this embodiment tends to be consistent and is all within 0.1 mm, effectively suppressing blur spots or color halos in the image. Figure 8 The data also includes astigmatic field curves of the temperature measuring lens, where the X-curve represents the sagittal field curve at 546 nm and the Y-curve represents the meridional field curve at 546 nm. As shown in the figures, the field curvature of the temperature measuring lens is within 0.025 mm, and both field curvature and astigmatism in each field of view are well corrected, with clear imaging at both the center and edges of the field of view. In summary, the temperature measuring lens exhibits good control over longitudinal spherical aberration and field curvature, possesses excellent imaging quality, and has a field of view (FOV) ≥ 130°.

[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] The embodiments described above are merely specific and detailed examples of the embodiments described in this application, and should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A narrow, wide-angle temperature measuring lens, characterized in that: The system comprises, sequentially arranged along the optical axis, a first lens (L1) with negative optical power, a second lens (L2) with negative optical power, an aperture stop (STO), a third lens (L3) with positive optical power, a fourth lens (L4) with positive optical power, a fifth lens (L5) with negative optical power, a sixth lens (L6) with positive optical power, a seventh lens (L7) with positive optical power, an eighth lens (L8), a ninth lens (L9), a tenth lens (L10), and an eleventh lens (L11), wherein among the eighth lens (L8), the ninth lens (L9), the tenth lens (L10), and the eleventh lens (L11), two lenses have positive optical power and two lenses have negative optical power, and the following conditions are satisfied: 38≤ ≤46 in, The distance from the object surface of the first lens (L1) to the image surface is on the axis. The distance between the image-side surface and the image plane of the eleventh lens (L11) is measured in mm.

2. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, The combined effective focal length of the first lens (L1) to the sixth lens (L6) is... The combined effective focal length of the seventh lens (L7) to the eleventh lens (L11) is... The effective focal length of the seventh lens (L7) is... The combined effective focal length of the eighth lens (L8) to the eleventh lens (L11) is in mm.

3. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, Let be the radius of curvature of the image-side surface of the second lens (L2). The distance is the axial distance from the image side of the second lens (L2) to the object side of the third lens (L3), both in mm.

4. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, This is the maximum effective half-aperture of the seventh lens (L7). The effective focal length of the elongated wide-angle temperature measuring lens is in mm.

5. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, This is the maximum effective half-aperture of the first lens (L1). The maximum effective half-aperture of the eleventh lens (L11) is expressed in mm.

6. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, The distance between the image-side surface of the seventh lens (L7) and the object-side surface of the eighth lens (L8) is on the axis, in mm.

7. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: in, abv9 is the Abbe number of the eighth lens (L8), abv10 is the Abbe number of the ninth lens (L9), abv10 is the Abbe number of the tenth lens (L10), and abv11 is the Abbe number of the eleventh lens (L11).

8. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: ; or ; in, The distance on the axis from the image side of the seventh lens (L7) to the object side of the eighth lens (L8) is denoted as L7. The effective focal length of the elongated wide-angle temperature measuring lens is... denoted as the radius of curvature of the object-side surface of the second lens (L2), both in mm.

9. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The narrow, wide-angle temperature measuring lens also meets the following conditions: ； ； ； ； in, The effective focal length of the elongated wide-angle temperature measuring lens is... The effective focal length of the seventh lens (L7) is... The combined effective focal length of the first lens (L1) to the sixth lens (L6) is... The combined effective focal length of the ninth lens (L9) to the tenth lens (L10) is in mm.

10. The narrow, wide-angle temperature measuring lens as described in claim 1, characterized in that: The first lens (L1) is a convex-concave lens, the second lens (L2) is a convex-concave lens, the third lens (L3) is a concave-convex lens, the fourth lens (L4) is a biconvex lens, the fifth lens (L5) is a convex-concave lens, the sixth lens (L6) is a biconvex lens, the seventh lens (L7) is a concave-convex lens, the eighth lens (L8) is a convex-concave lens or a concave-convex lens, the ninth lens (L9) is a biconvex lens or a convex-concave lens, the tenth lens (L10) is a biconvex lens or a concave-convex lens, and the eleventh lens (L11) is a biconvex lens or a concave-convex lens.

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