CN218298648U - close-up lens - Google Patents

Abstract

The utility model discloses a near-object shooting lens, which comprises a diaphragm, a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially along an optical axis from the object side to the image side, The first lens has negative diopter, the second lens has positive diopter, the third lens has negative diopter, the fourth lens has positive diopter, and the fifth lens has positive diopter. The utility model has the advantages of small volume, low cost, complementary temperature between lenses, and small temperature drift of the lens, so that the lens can still image clearly in high and low temperature environments; it has been subjected to extinction treatment, and the lens can be used normally when there is interference from other light sources ; In addition, the lens tolerance is not sensitive, suitable for mass production.

Description

close-up lens

technical field

The utility model relates to the technical field of optical lenses, in particular to a near-object shooting lens.

Background technique

With the continuous advancement of science and technology and the continuous development of society, optical imaging lenses have also developed rapidly in recent years, and are widely used in various fields such as smart phones, tablet computers, video conferencing, vehicle monitoring, and security monitoring. The requirements for optical imaging lenses are also getting higher and higher.

The existing near-object shooting lens focuses on near-objects for shooting, but it does not consider temperature drift, and when used in high-temperature and cold weather, the definition is reduced; in addition, there is no extinction treatment, and when there is interference from other light sources, The resolution is reduced; at the same time, the tolerance is more sensitive, which is not suitable for mass production.

In view of this, the inventors of the present application have invented a close object shooting lens.

Utility model content

The purpose of the utility model is to provide a near-object shooting lens with small volume, high resolution, small temperature drift and insensitive tolerance.

In order to achieve the above object, the utility model adopts the following technical solutions: a close-object shooting lens, including a diaphragm, a first lens, a second lens, a third lens, a Four lenses, the fifth lens, the first lens to the fifth lens each include an object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through;

The first lens has a negative diopter, and the object side of the first lens is concave, and the image side is concave;

The second lens has a positive diopter, and the object side of the second lens is convex, and the image side is convex;

The third lens has a negative diopter, and the object side of the third lens is concave, and the image side is convex;

The fourth lens has positive diopter, and the object side of the fourth lens is concave, and the image side is convex;

The fifth lens has positive diopter, and the object side of the fifth lens is convex, and the image side is convex.

Further, the lens satisfies: 1<|(f1/f)|<2, 0.5<|(f2/f)|<1.5, 0.5<|(f3/f)|<1.5, 1<|(f4/f )|<2, 1.5<|(f5/f)|<2.5 Wherein, f is the focal length of the lens, f1, f2, f3, f4, f5 are respectively the first lens, the second lens, the third lens, the first lens The focal length of the four lenses and the fifth lens.

Further, the focal length f of the lens satisfies: f=5mm.

Further, the dispersion coefficient vd3 of the third lens satisfies: vd3>70, and the temperature coefficient of refractive index of the third lens is a negative value.

Further, the working object distance of this lens is 670mm.

Further, the total optical length TTL of the lens satisfies: TTL≤10.7mm.

Further, the first lens to the fifth lens are all glass spherical lenses.

Further, the maximum light transmission of the lens is F/NO=2.0.

After adopting the above technical solution, the utility model has the following advantages compared with the prior art:

The utility model has the advantages of small volume, low cost, complementary temperature between lenses, and small temperature drift of the lens, so that the lens can still image clearly in high and low temperature environments; it has been subjected to extinction treatment, and the lens can be used normally when there is interference from other light sources ; In addition, the lens tolerance is not sensitive, suitable for mass production.

Description of drawings

Fig. 1 is the optical path diagram of the utility model embodiment 1;

Fig. 2 is the MTF curve diagram of the lens under visible light in Example 1 of the present utility model;

Fig. 3 is a spot diagram of the lens under visible light in Embodiment 1 of the present utility model;

Fig. 4 is the relative illuminance diagram of the lens under visible light in Embodiment 1 of the utility model;

Fig. 5 is the optical path diagram of the utility model embodiment 1;

Fig. 6 is the MTF curve diagram of the lens under visible light in Example 1 of the present utility model;

Fig. 7 is a spot diagram of the lens under visible light in Example 1 of the present utility model;

Fig. 8 is a relative illuminance diagram of the lens under visible light in Embodiment 1 of the present utility model;

Fig. 9 is the optical path diagram of the utility model embodiment 1;

Fig. 10 is the MTF curve diagram of the lens under visible light in Example 1 of the present utility model;

Fig. 11 is a spot diagram of the lens under visible light in Example 1 of the present utility model;

Fig. 12 is a relative illuminance diagram of the lens under visible light in Embodiment 1 of the present utility model.

Explanation of reference signs:

1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Diaphragm; 7. Protective glass.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Here, "a lens has positive refractive power (or negative refractive power)" means that the paraxial refractive power of the lens calculated by Gaussian optical theory is positive (or negative). The so-called "object side (or image side) of the lens" is defined as a specific range where imaging light passes through the lens surface. The concave-convex of the lens surface can be judged according to the judgment method of ordinary knowledge in this field, that is, the concave-convex of the lens surface can be judged by the positive and negative sign of the radius of curvature (abbreviated as R value). R-values are commonly used in optical design software such as Zemax or CodeV. The R value is also commonly found in the lens data sheet of the optical design software. For the side of the object, when the R value is positive, it is judged that the side of the object is convex; when the value of R is negative, it is judged that the side of the object is concave. Conversely, in terms of the image side, when the R value is positive, it is judged that the image side is concave; when the R value is negative, it is judged that the image side is convex.

The utility model discloses a near-object shooting lens, which comprises a diaphragm 6, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, The fifth lens 5, each of the first lens 1 to the fifth lens 5 includes an object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through;

The first lens 1 has a negative diopter, and the object side of the first lens 1 is concave, and the image side is concave;

The second lens 2 has a positive diopter, and the object side of the second lens 2 is convex, and the image side is convex;

The third lens 3 has a negative diopter, and the object side of the third lens 3 is concave, and the image side is convex;

The fourth lens 4 has a positive diopter, and the object side of the fourth lens 4 is concave, and the image side is convex;

The fifth lens 5 has positive diopter, and the object side of the fifth lens 5 is convex, and the image side is convex.

The lens satisfies: 1<|(f1/f)|<2, 0.5<|(f2/f)|<1.5, 0.5<|(f3/f)|<1.5, 1<|(f4/f)|< 2, 1.5<|(f5/f)|<2.5 Wherein, f is the focal length of the lens, f1, f2, f3, f4, f5 are respectively the first lens 1, the second lens 2, the third lens 3, the first lens The focal length of the four lenses 4 and the fifth lens 5. Reasonably distribute the optical power, improve the optical performance, and meet the needs of use. Specifically, the focal length f of the lens satisfies: f=5mm.

The dispersion coefficient vd3 of the third lens 3 satisfies: vd3>70, and the temperature coefficient of refractive index of the third lens 3 is a negative value. The third lens of the lens, that is, the third lens 3 uses materials with positive refractive index, high Abbe number (Vd) and negative temperature coefficient of refraction index (dn/dt) to offset the temperature change for lens back focus shift The impact of temperature drift is effectively avoided, so that the patented lens can produce clear images when used in the temperature range of -40°C to 105°C.

The working object distance of this lens is 670mm. The working object distance matches the actual use to ensure the best image quality.

The total optical length TTL of the lens satisfies: TTL≤10.7mm. And the maximum light transmission F/NO of the lens is 2.0. Meet the needs of close-up photography.

The first lens 1 to the fifth lens 5 are all glass spherical lenses.

The near-object shooting lens of the present invention will be described in detail below with specific embodiments.

Example 1

Referring to Fig. 1, the utility model discloses a near-object shooting lens, an aperture 6, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a fifth lens 5. Each of a lens 1 to the fifth lens 5 includes an object side facing the object side and allowing the imaging light to pass through and an image side facing the image side and allowing the imaging light to pass through;

The first lens 1 has a negative diopter, and the object side of the first lens 1 is concave, and the image side is concave;

The second lens 2 has a positive diopter, and the object side of the second lens 2 is convex, and the image side is convex;

The third lens 3 has a negative diopter, and the object side of the third lens 3 is concave, and the image side is convex;

The fourth lens 4 has a positive diopter, and the object side of the fourth lens 4 is concave, and the image side is convex;

The fifth lens 5 has positive diopter, and the object side of the fifth lens 5 is convex, and the image side is convex.

The detailed optical data of this specific embodiment are shown in Table 1-1.

Detailed optical data of Table 1-1 Example 1

In this embodiment, please refer to Figure 2 for the MTF curve diagram of the lens under visible light. It can be seen from the figure that when the spatial frequency of this lens reaches 84 lp/mm, the MTF value is greater than 0.2, the imaging quality is excellent, and the resolution of the lens is high. Please refer to Figure 3 for the spot diagram of the lens under visible light. It can be seen from the figure that the RMS of each field of view of this lens under visible light is less than 8.6um, with small aberration and good imaging quality. Please refer to Figure 4 for the relative illuminance diagram of the lens under visible light. It can be seen from the figure that the relative illuminance is greater than 60%, and the imaging is uniform.

Example 2

As shown in FIG. 5 , compared with Embodiment 1, this embodiment differs mainly in that the optical parameters such as the radius of curvature of each lens surface and lens thickness are different.

The detailed optical data of this specific embodiment are shown in Table 2-1.

Detailed optical data of Table 2-1 Example 2

In this embodiment, please refer to Figure 6 for the MTF curve diagram of the lens under visible light. It can be seen from the figure that when the spatial frequency of this lens reaches 84 lp/mm, the MTF value is greater than 0.2, the imaging quality is excellent, and the resolution of the lens high. Please refer to Figure 7 for the spot diagram of the lens under visible light. It can be seen from the figure that the RMS of each field of view of the lens under visible light is less than 10.1um, with small aberration and good imaging quality. Please refer to Figure 8 for the relative illuminance diagram of the lens under visible light. It can be seen from the figure that the relative illuminance is greater than 60%, and the imaging is uniform.

Example 3

As shown in FIG. 9 , compared with Embodiment 1, this embodiment is mainly different in optical parameters such as the radius of curvature of each lens surface and lens thickness.

The detailed optical data of this specific embodiment are shown in Table 3-1.

Detailed optical data of Table 3-1 Example 3

In this embodiment, please refer to Figure 10 for the MTF curve diagram of the lens under visible light. It can be seen from the figure that when the spatial frequency of this lens reaches 84 lp/mm, the MTF value is greater than 0.2, the imaging quality is excellent, and the resolution of the lens is high. Please refer to Figure 11 for the spot diagram of the lens under visible light. It can be seen from the figure that the RMS of each field of view of the lens under visible light is less than 8.8um, with small aberration and good imaging quality. Please refer to Figure 12 for the relative illuminance diagram of the lens under visible light. It can be seen from the figure that the relative illuminance is greater than 60%, and the imaging is uniform.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (8)

1. A near-object shooting lens, characterized in that: comprise a diaphragm, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged successively along an optical axis from the object side to the image side, The first lens to the fifth lens each include an object side facing the object side and allowing the imaging light to pass through, and an image side facing the image side and allowing the imaging light to pass through; The first lens has a negative diopter, and the object side of the first lens is concave, and the image side is concave; The second lens has a positive diopter, and the object side of the second lens is convex, and the image side is convex; The third lens has a negative diopter, and the object side of the third lens is concave, and the image side is convex; The fourth lens has positive diopter, and the object side of the fourth lens is concave, and the image side is convex; The fifth lens has positive diopter, and the object side of the fifth lens is convex, and the image side is convex. 2. A close object shooting lens as claimed in claim 1, characterized in that: the lens satisfies: 1<|(f1/f)|<2, 0.5<|(f2/f)|<1.5, 0.5< |(f3/f)|<1.5, 1<|(f4/f)|<2, 1.5<|(f5/f)|<2.5 Among them, f is the focal length of the lens, f1, f2, f3, f4, f5 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, respectively. 3. A close object shooting lens according to claim 1 or 2, characterized in that: the focal length f of the lens satisfies: f=5mm. 4 . The near-object shooting lens according to claim 1 , wherein the dispersion coefficient vd3 of the third lens satisfies: vd3>70, and the temperature coefficient of refractive index of the third lens is a negative value. 5. A close object shooting lens according to claim 1, characterized in that: the working object distance of the lens is 670 mm. 6 . The near-object shooting lens according to claim 1 , wherein the total optical length TTL of the lens satisfies: TTL≤10.7mm. 7 . The close-object shooting lens according to claim 1 , wherein the first lens to the fifth lens are all glass spherical lenses. 8. A close-object shooting lens according to claim 1, characterized in that: the maximum light transmission of the lens is F/NO=2.0.

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