Glass-plastic hybrid athermal optical lens and its working method
By combining glass spherical and plastic aspherical lenses in optical lenses, the temperature drifting problem of optical lenses in the high-temperature and low-temperature environments in the prior art is solved, 4K high-resolution and wide-angle imaging are achieved, and day and night confocal needs are met. Optimize aberration problems and improve the wear resistance and environmental stability of the lens.
Patent Information
- Application Number
- CN202211155190.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-22
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-09-22
AI Technical Summary
Existing optical lenses have a large temperature drift in high and low temperature environments, which is difficult to meet the needs of 4K high-resolution and wide-angle imaging. The number of lenses and sizes are large, which affects the imaging quality.
Using glass-plastic hybrid thermal-free optical lens, the number of lenses is controlled by combining glass spherical lenses and plastic aspherical lenses to achieve 4K high-resolution, wide-angle, day and night confocal optical performance, and using high-refractive index glass spherical lenses and negative refractive The rate temperature coefficient of plastic lens optimizes aberration problem.
It realizes 4K definition imaging, reduces the lens head size, improves wear resistance, reduces the focal difference in high and low temperatures, adapts to different lighting conditions, and ensures imaging quality and environmental stability.
Smart Images
Figure CN115453720B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a glass-plastic hybrid athermal optical lens and a working method thereof. Background Art
[0002] As the most basic component for image capture, optical lens is one of the most critical components of optoelectronic equipment. It is used in all aspects of daily life, including smart phones, automobiles, security monitoring, automation industry and other fields. However, the optical lenses currently used generally have the following shortcomings: insufficient optical imaging quality, which makes it difficult to meet the 4K clarity required by the market; poor environmental adaptability, large temperature drift at high and low temperatures, affecting imaging quality; while improving image quality, the number of lenses is large and the size is large; plastic lenses have good plasticity and can be designed into aspheric lenses of various shapes, and are widely used in high-definition optical lenses. Summary of the invention
[0003] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a glass-plastic hybrid athermal optical lens and a working method thereof. The glass-plastic hybrid athermal optical lens is matched with a glass spherical lens and a plastic aspherical lens, which can meet the optical performance of 4K high resolution, wide angle, and day and night confocality while controlling the number of lenses.
[0004] In order to solve the above technical problems, the technical solution of the present invention is:
[0005] A glass-plastic hybrid athermalized optical lens comprises a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along a light incident path; the first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a double convex positive lens, the fourth lens is a meniscus positive lens, the fifth lens is a double convex positive lens, the sixth lens is a double concave negative lens, and the seventh lens is a double convex positive lens; the object plane and the image plane of the first lens are both facing the object side, and the object plane and the image plane of the fourth lens are both facing the image side, and the lenses are made of glass and plastic materials, wherein the first and fifth lenses are glass spherical lenses, and the second, third, fourth, sixth and seventh lenses are all plastic aspherical lenses.
[0006] Preferably, the first lens is a glass spherical lens with a high refractive index, and the fifth lens has a negative refractive index temperature coefficient; the focal length of the optical system is , the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are respectively ,, , , , , ,in , , , , , , and Meet the following ratio: -3.5< / <-1.5, -3.5< / <-1.5, 3.0< / <5.0, 18.0< / <20.0, 1.5< / <3.5, -2.5< / <-0.5, 0.5< / <2.5.
[0007] Preferably, the first lens satisfies the relationship: ≥1.5, ≤50.0; the second lens satisfies the relationship: ≥1.5, ≥50.0; the third lens satisfies the relationship: ≥1.5, ≤50.0; the fourth lens satisfies the relationship: ≥1.5, ≥50.0; the fifth lens satisfies the relationship: ≤1.5, ≥50.0; the sixth lens satisfies the relationship: ≥1.5, ≤50.0; the seventh lens satisfies the relationship: ≥1.5, ≥50.0; is the refractive index, is the Abbe constant.
[0008] Preferably, the second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are aspherical lenses, and the aspherical curve equation is expressed as:
[0009]
[0010] Wherein, Z is the height of the aspheric surface from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; , , , , , , , All are high-order coefficients.
[0011] Preferably, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤10.0; the F number of the optical system ≤2.0; the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥2.5; the refractive index of the first lens ; The refractive index temperature coefficient of the fifth lens .
[0012] Preferably, the technical indicators achieved by the optical system are as follows:
[0013] (1) Focal length: 2.0≤EFFL≤4.0mm; (2) Aperture F≤2.0; (3) Field of view: 2w≥150°; (4) Working band: visible light band and 850nm band.
[0014] The specific parameters used in the above technical indicators are as follows:
[0015]
[0016] The aspheric coefficients of each aspheric lens are as follows:
[0017]
[0018] The present invention discloses a working method of a glass-plastic hybrid athermal optical lens. The optical lens comprises a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along the incident light path of the light. The first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a double convex positive lens, the fourth lens is a meniscus positive lens, the fifth lens is a double convex positive lens, the sixth lens is a double concave negative lens and the seventh lens is a double convex positive lens. The object plane and the image plane of the first lens are both facing the object side, and the object plane and the image plane of the fourth lens are both facing the image side. The lens is made of glass and plastic materials, wherein the first and fifth lenses are glass spherical lenses, and the second, third, fourth, sixth and seventh lenses are all plastic aspherical lenses. The optical lens realizes a focal length of: 2.0≤EFFL≤4.0mm; (2) an aperture F≤2.0; (3) a field of view angle of: 2w≥150°; and (4) an operating band of: a visible light band and an 850nm band.
[0019] When light is incident, it enters the first lens, the second lens, the third lens, the fourth lens, the aperture, the fifth lens, the sixth lens, the seventh lens and the equivalent glass plate in sequence along the optical path and forms an image on the IMA imaging surface.
[0020] Compared with the prior art, the present invention has the following advantages:
[0021] 1. The glass-plastic hybrid athermal optical lens provided by the present invention adopts seven optical lenses. By reasonably matching spherical lenses and aspherical lenses, various axial chromatic aberrations, vertical axis chromatic aberrations and high-order chromatic aberrations are corrected, so that the optical system achieves 4K clarity.
[0022] 2. The first lens is a high-refractive-index glass spherical lens, which reduces the size of the head while improving the wear resistance of the lens.
[0023] 3. The difference in back focus between the lens in the visible light band and the infrared band is small, meeting the requirements of day and night confocality.
[0024] 4. While ensuring the imaging quality, it has a high relative illumination and can adapt to different lighting conditions.
[0025] 5. The fifth lens has a negative refractive index temperature coefficient, which ensures that the lens has a small defocusing amount and good environmental stability at -40℃ to 80℃.
[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 is a schematic diagram of the optical structure of the present invention;
[0028] Figure 2 It is the full working band axial chromatic aberration diagram of the present invention;
[0029] Figure 3 It is the vertical axis chromatic aberration diagram of the full working band of the present invention;
[0030] Figure 4 It is the field curvature distortion diagram of the full working band of the present invention;
[0031] Figure 5 It is a defocus curve diagram of the present invention at a low temperature of -40°C in the visible light band;
[0032] Figure 6 It is a defocus curve diagram of the present invention at room temperature 25° C. in the visible light band;
[0033] Figure 7 This is a defocus curve diagram of the present invention at a high temperature of 80°C in the visible light band;
[0034] In the figure: L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; STO-aperture; L5-fifth lens; L6-fifth lens; L7-seventh lens; L8-equivalent glass plate; IMA-imaging surface. DETAILED DESCRIPTION
[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods;
[0036] like Figure 1 As shown, a glass-plastic hybrid athermalized optical lens is provided with a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an equivalent glass plate L8 and an IMA-imaging surface in sequence from the object side to the image side; without considering the backcurvature caused by the aspheric coefficient, the first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a double convex positive lens, the fourth lens is a meniscus positive lens, the fifth lens is a double convex positive lens, the sixth lens is a double concave negative lens, and the seventh lens is a double convex positive lens; the object plane and the image plane of the first lens are both facing the object side, and the object plane and the image plane of the fourth lens are both facing the image side, and the lenses are made of glass and plastic materials, wherein the first and fifth lenses are glass spherical lenses, and the second, third, fourth, sixth and seventh lenses are all plastic aspheric lenses.
[0037] The focal length of the optical system is , the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are respectively ,, , , , , ,in , , , , , , and Meet the following ratio: -3.5< / <-1.5, -3.5< / <-1.5, 3.0< / <5.0, 18.0< / <20.0, 1.5< / <3.5, -2.5< / <-0.5, 0.5< / <2.5.
[0038] The first lens satisfies the relationship: ≥1.5, ≤50.0; the second lens satisfies the relationship: ≥1.5, ≥50.0; the third lens satisfies the relationship: ≥1.5, ≤50.0; the fourth lens satisfies the relationship: ≥1.5, ≥50.0; the fifth lens satisfies the relationship: ≤1.5, ≥50.0; the sixth lens satisfies the relationship: ≥1.5, ≤50.0; the seventh lens satisfies the relationship: ≥1.5, ≥50.0; is the refractive index, is the Abbe constant.
[0039] The second lens, the third lens, the fourth lens, the sixth lens and the seventh lens are aspherical lenses, and the aspherical curve equation is expressed as:
[0040]
[0041] Z is the height of the aspheric surface from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; , , , , , , , All are high-order coefficients.
[0042] The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤10.0; the F number of the optical system ≤2.0; the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥2.5; the refractive index of the first lens ; The refractive index temperature coefficient of the fifth lens .
[0043] like Figures 2 to 4 As shown in the figure, through the reasonable lens combination of the present application, various aberration problems of the system are effectively optimized and the imaging quality is improved; Figures 5 to 7 As shown, the optical lens has a smaller defocus at -40°C, 25°C and 80°C, which effectively ensures the imaging quality at high and low temperatures.
[0044] The technical indicators achieved by the optical system of this embodiment are as follows:
[0045] (1) Focal length: 2.0≤EFFL≤4.0mm; (2) Aperture F≤2.0; (3) Field of view: 2w≥150°; (4) Working band: visible light band and 850nm band.
[0046] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:
[0047] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:
[0048] When light is incident, it enters the first lens, the second lens, the third lens, the fourth lens, the aperture, the fifth lens, the sixth lens, the seventh lens and the equivalent glass plate in sequence along the optical path and forms an image on the IMA imaging surface.
[0049] Compared with the prior art, the present invention has the following advantages:
[0050] 1. The glass-plastic hybrid athermal optical lens provided by the present invention adopts seven optical lenses. By reasonably matching spherical lenses and aspherical lenses, various axial chromatic aberrations, vertical axis chromatic aberrations and high-order chromatic aberrations are corrected, so that the optical system achieves 4K clarity.
[0051] 2. The first lens is a high-refractive-index glass spherical lens, which reduces the size of the head while improving the wear resistance of the lens.
[0052] 3. The difference in back focus between the lens in the visible light band and the infrared band is small, meeting the requirements of day and night confocality.
[0053] 4. While ensuring the imaging quality, it has a high relative illumination and can adapt to different lighting conditions.
[0054] 5. The fifth lens has a negative refractive index temperature coefficient, which ensures that the lens has a small defocusing amount and good environmental stability at -40℃ to 80℃.
[0055] In summary, the optical system of the present application achieves a small overall length, wide angle, and athermal design, while also providing good corrections for on-axis and off-axis aberrations.
[0056] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.
Claims
1. A glass-plastic hybrid athermal optical lens, characterized in that: The optical lens includes a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from left to right along the light incident optical path; the first lens is a meniscus negative lens, the second lens is a biconcave negative lens, the third lens is a biconvex positive lens, the fourth lens is a meniscus positive lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconcave negative lens, and the seventh lens is a biconvex positive lens; the object surface and the image surface of the first lens both face the object side, the object surface and the image surface of the fourth lens both face the image side, and the lenses are made of glass and plastic materials, wherein the first and fifth lenses are glass spherical lenses, and the second, third, fourth, sixth, and seventh lenses are all plastic aspherical lenses; the focal length of the optical lens optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens are f1, f2, f3, f4, f5, f6, and f7 respectively, where f1, f2, f3, f4, f5, f6, and f7 satisfy the following ratios with f: -3.5 < f1 / f < -1.5, -3.5 < f2 / f < -1.5, 3.0 < f3 / f < 5.0, 18.0 < f4 / f < 20.0, 1.5 < f5 / f < 3.5, -2.5 < f6 / f < -0.5, 0.5 < f7 / f < 2.5; the second lens, the third lens, the fourth lens, the sixth lens, and the seventh lens are aspherical lenses, and the expression of the aspherical curve equation is: where Z is the sagitta height from the vertex of the aspherical surface when the aspherical surface is at a position with a height of h along the optical axis direction; c is the paraxial curvature of the aspherical surface; k is the conic constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order term coefficients, and there are only 7 lenses with optical power.