All-glass wide-angle optical lens

Abstract

The present application relates to a kind of all glass wide-angle optical lens, the optical system of lens is by the first lens, second lens, third lens, diaphragm, fourth lens, fifth lens and sixth lens in order along the light path of light incidence from left to right sequentially set composition;First lens is meniscus negative lens, second lens is double concave negative lens, third lens is double convex positive lens, fourth lens is double convex positive lens, fifth lens is meniscus negative lens, sixth lens is double convex positive lens, second lens and third lens constitute first cemented lens group, fourth lens and fifth lens constitute second cemented lens group, first lens, second lens, third lens, fourth lens and fifth lens are glass spherical lens, and sixth lens is glass aspheric lens.The present application is realized while 4K ultra-high definition imaging, and the sensitivity to environmental change is low, is not influenced by temperature and humidity and other environmental factors, wide-angle lens aperture value is smaller, relative luminance is high, and dark environment imaging effect is good.

Description

Technical fields:

[0001] This invention belongs to the field of lens technology, and in particular relates to an all-glass wide-angle optical lens. Background technology:

[0002] With the continuous advancement and development of video surveillance technology, high-definition video surveillance technology is constantly redefining its standards and requirements. Users' demands for video surveillance products are also constantly increasing, and functional requirements are continuously being improved and stabilized. Optical lenses play a crucial role in the acquisition phase of video surveillance technology, significantly impacting the clarity of the monitored video. Today's 4K high-definition lenses offer significantly higher clarity compared to ordinary lenses, capable of resolving more subtle details and meeting the demands for higher-definition real-time monitoring. Currently, most 4K high-definition lenses utilize plastic aspherical lenses, which have drawbacks such as poor environmental adaptability and a relatively small aperture. Summary of the Invention:

[0003] The present invention addresses the problems existing in the prior art by providing an all-glass wide-angle optical lens that is reasonably designed to achieve 4K ultra-high-definition imaging, while also having high light transmission capability and excellent environmental stability.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an all-glass wide-angle optical lens, the optical system of which is composed of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light 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 biconvex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a biconvex positive lens; the second and third lenses form a first cemented lens group, and the fourth and fifth lenses form a second cemented lens group; the first, second, third, fourth, and fifth lenses are all glass spherical lenses, and the sixth lens is a glass aspherical lens.

[0005] Furthermore, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the fifth lens is concave, and the image-side surface is convex.

[0006] Furthermore, the air gap between the first lens and the second lens is 4.35–4.55 mm; the air gap between the third lens and the fourth lens is 0.1–0.3 mm; and the air gap between the fifth lens and the sixth lens is 0.55–1.0 mm.

[0007] Furthermore, the focal length of the optical system is f, and the focal lengths of the first, second, third, fourth, fifth, and sixth lenses are f1, f2, f3, f4, f5, and f6, respectively. The ratios of f1, f2, f3, f4, f5, and f6 to f satisfy the following ratio: -2.5 <f1 / f<-1.5,-2.5<f2 / f<-1.5,0.5<f3 / f<1.5,1.5<f4 / f<2.5,-2.5<f5 / f<-1.5,2.0<f6 / f<3.0。

[0008] Furthermore, the first lens satisfies the relationship: 1.5 ≤ N d ≤1.8, V d ≥50.0; The second lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The third lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; where N d V is the refractive index. d Let be Abbe's constant.

[0009] Furthermore, the sixth lens is an aspherical lens, and the equation for the aspherical curve is expressed as follows:

[0010]

[0011] Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0012] Furthermore, the total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 6.0.

[0013] Furthermore, the F-number of the optical system is ≤1.6.

[0014] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f ≥ 2.0.

[0015] Furthermore, the refractive index temperature coefficient of the fourth lens, dn / dt, is less than 0.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed and achieves 4K ultra-high-definition imaging while being less sensitive to environmental changes and unaffected by environmental factors such as temperature and humidity. The wide-angle lens has a smaller aperture value, higher relative illumination, and better imaging effect in dark environments. Attached image description:

[0017] Figure 1 This is a schematic diagram of the optical structure according to an embodiment of the present invention;

[0018] Figure 2 This is an axial chromatic aberration diagram of the entire working band of this invention.

[0019] Figure 3 This is a cross-axis chromatic aberration diagram of the entire working band of this invention.

[0020] Figure 4 This is a field curvature distortion diagram of the entire working band of this invention embodiment;

[0021] Figure 5 This is a defocusing curve of the present invention at a low temperature of -40°C in the visible light band according to an embodiment of the invention;

[0022] Figure 6 This is a defocusing curve of the present invention at room temperature (25°C) in the visible light band according to an embodiment of the invention;

[0023] Figure 7 This is a defocusing curve of the present invention at a high temperature of 85°C in the visible light band.

[0024] In the picture:

[0025] L1 - First lens; L2 - Second lens; L3 - Third lens; STO - Aperture stop; L4 - Fourth lens; L5 - Fifth lens; L6 - Sixth lens; L7 - Equivalent glass plate; IMA - Imaging surface. Detailed implementation method:

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1As shown, this invention discloses an all-glass wide-angle optical lens. The lens's optical system comprises a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path. Without considering the curvature caused by aspherical coefficients, the first lens is a meniscus negative lens, with a convex object-side surface and a concave image-side surface. The second lens is a biconcave negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a meniscus negative lens, with a concave object-side surface and a convex image-side surface. The sixth lens is a biconvex positive lens. The second and third lenses form a first cemented lens group, and the fourth and fifth lenses form a second cemented lens group. All lenses are made of glass, wherein the first, second, third, fourth, and fifth lenses are all spherical glass lenses, and the sixth lens is a glass aspherical lens.

[0028] In this embodiment, the air gap between the first lens and the second lens is 4.35–4.55 mm; the air gap between the third lens and the fourth lens is 0.1–0.3 mm; and the air gap between the fifth lens and the sixth lens is 0.55–1.0 mm.

[0029] In this embodiment, the focal length of the optical system is f, and the focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are f1, f2, f3, f4, f5, and f6, respectively. The ratios of f1, f2, f3, f4, f5, and f6 to f satisfy the following ratio: -2.5 <f1 / f<-1.5,-2.5<f2 / f<-1.5,0.5<f3 / f<1.5,1.5<f4 / f<2.5,-2.5<f5 / f<-1.5,2.0<f6 / f<3.0。

[0030] In this embodiment, the first lens satisfies the relationship: 1.5 ≤ N d ≤1.8, V d ≥50.0; The second lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The third lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; where Nd V is the refractive index. d Let be Abbe's constant.

[0031] In this embodiment, the sixth lens is an aspherical lens, and the equation of the aspherical curve is expressed as follows:

[0032]

[0033] Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0034] The aspherical coefficients of the aspherical lenses in the optical system of this embodiment are shown in the table below:

[0035]

[0036] In this embodiment, the total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 6.0.

[0037] In this embodiment, the F-number of the optical system is ≤1.6.

[0038] In this embodiment, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f≥2.0.

[0039] In this embodiment, the refractive index temperature coefficient dn / dt of the fourth lens is <0.

[0040] In this embodiment, the aperture stop of the optical system is located between the third lens and the fourth lens.

[0041] In this embodiment, an equivalent glass plate is provided on the right side of the sixth lens.

[0042] In this embodiment, the technical specifications achieved by the optical system are as follows:

[0043] (1) Focal length: 3.0≤EFFL≤4.0mm;

[0044] (2) Aperture F≤1.6;

[0045] (3) Field of view: 2w ≥ 100°;

[0046] (4) Operating band: Visible light band.

[0047] To achieve the above design parameters, the specific design of the optical system adopted in this embodiment is shown in the table below:

[0048]

[0049] In this embodiment, the optical system achieves a small size, a large relative aperture, and a thermal design, while also providing good correction for on-axis and off-axis aberrations, enabling the system to achieve 4K image quality.

[0050] In this embodiment, the lens effectively corrects on-axis and off-axis aberrations, enabling the system to achieve 4K image quality with high light transmission capability and excellent environmental stability.

[0051] In this embodiment, as Figures 2 to 4 As shown, by using appropriate lens combinations, various aberrations in the system are effectively optimized, thus improving image quality; for example... Figures 5 to 7 As shown, the optical lens has a small defocus amount at -40℃ and 85℃, which effectively ensures the imaging quality at high and low temperatures.

[0052] The advantages of this invention are as follows: It employs six optical lenses, utilizing the aberration correction characteristics of molded aspherical lenses to ensure 4K resolution imaging while reducing the number of lenses, thus shortening the system size; both the spherical and aspherical lenses are made of glass, ensuring good light transmittance while maintaining image quality, and the larger relative aperture allows for adaptation to different lighting conditions; based on the effect of the refractive index temperature coefficient, the fourth lens of the system has a negative refractive index temperature coefficient, and considering the temperature compensation characteristics of the lens base, the lens exhibits minimal defocusing within a temperature range of -40℃ to 85℃, demonstrating good environmental stability.

[0053] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0054] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0055] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An all-glass wide-angle optical lens, characterized in that: The optical system of the lens consists of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth 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 biconvex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a biconvex positive lens. The second lens and the third lens form a first cemented lens group, and the fourth lens and the fifth lens form a second cemented lens group. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all glass spherical lenses, and the sixth lens is a glass aspherical lens; the air gap between the first lens and the second lens is 4.35 mm to 4.55 mm; the air gap between the third lens and the fourth lens is 0.1 mm to 0.3 mm; the air gap between the fifth lens and the sixth lens is 0.55 mm to 1.0 mm; the focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are f1, f2, f3, f4, f5, f6 respectively, where f1, f2, f3, f4, f5, f6 and f satisfy the following ratios: -2.5 < f1 / f < -1.5, -2.5 < f2 / f < -1.5, 0.5 < f3 / f < 1.5, 1.5 < f4 / f < 2.5, -2.5 < f5 / f < -1.5, 2.0 < f6 / f < 3.0; the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 6.

0.

2. The all-glass wide-angle optical lens according to claim 1, characterized in that: The object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the fifth lens is concave, and the image side surface is convex.

3. The all-glass wide-angle optical lens according to claim 1, characterized in that: The first lens satisfies the relationship: 1.5 ≤ N d ≤1.8, V d ≥50.0; The second lens satisfies the following relationship: N d ≤1.5, V d ≥50.0; The third lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The fourth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.8≤N d ≤2.0, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≤50.0; where N d V is the refractive index. d Let be Abbe's constant.

4. The all-glass wide-angle optical lens according to claim 1, characterized in that: The sixth lens is an aspherical lens, and the expression of the aspherical curve equation is: Where z is the distance from the vertex of the aspherical surface to the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, r=1 / c; k is the conic constant; a1, a2, a3, a4, a5, a6, a7, and a8 are all coefficients of higher-order terms.

5. The all-glass wide-angle optical lens according to claim 1, characterized in that: The F number of the optical system ≤ 1.

6.

6. The all-glass wide-angle optical lens according to claim 1, characterized in that: The image height H of the optical system and the focal length f of the optical system satisfy: H / f ≥ 2.

0.

7. The all-glass wide-angle optical lens according to claim 1, characterized in that: The refractive index temperature coefficient dn / dt of the fourth lens < 0.

Images