CN115808774A - an optical lens - Google Patents

Abstract

The invention relates to an optical lens, which is a first lens with negative refractive power sequentially from an object side to an image side along an optical axis, wherein the object side is provided with an inflection point, the position of the object side, which is close to a center, is a concave surface, and the image side is a concave surface; a second lens element with positive refractive power; a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a fourth lens element with negative refractive power; a fifth lens element with positive refractive power and convex image-side surface; a sixth lens element with negative refractive power having a convex object-side surface near the center; a diaphragm disposed between the second lens and the third lens or between the third lens and the fourth lens; and satisfies the conditional expression: a1 x F1+ a2 x F2+ a3 x F3+ a4 x F4+ a5 x F5+ a6 x F6<1000; wherein a1-a6 are thermal expansion coefficients of the materials of the first lens element to the sixth lens element of the optical lens, and F1-F6 are focal lengths of the first lens element to the sixth lens element of the optical lens. The wide-angle imaging system can keep a good imaging effect in a high-temperature and low-temperature environment while realizing wide angle, improve the influence of distortion on the lens and improve the illumination of the lens.

Description

an optical lens

technical field

The invention relates to the technical field of optical lenses, in particular to an optical lens.

Background technique

As the market demand for smart electronic products continues to increase, consumers have higher and higher imaging requirements for camera lenses mounted on electronic products. However, the existing wide-angle camera lens Distortion occurs. At the same time, wide-angle camera lenses are often all-plastic lenses, and most of the all-plastic lenses have poor temperature drift effects, which are difficult to meet normal use in high and low temperature environments. Therefore, there is an urgent need to develop an optical lens that can still maintain good imaging effects in high and low temperature environments.

Contents of the invention

In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an optical lens, which uses an all-plastic lens, limits the parameters of the lens, and realizes the effect of low-temperature drift, and can achieve a wide angle while being able to operate in a high-low temperature environment. Keep good image quality.

In order to achieve the above object, the main technical solutions adopted in the present invention include:

An optical lens, the optical lens is composed of six lenses, along the optical axis from the object side to the image side as follows:

The first lens, the first lens has a negative refractive power, the object side has an inflection point, the object side is concave near the center, and the image side is concave;

a second lens having a positive refractive power;

The third lens, the third lens has positive refractive power, the object side is convex, and the image side is convex;

a fourth lens, the fourth lens having a negative refractive power;

The fifth lens, the fifth lens has positive refractive power, and the image side is convex;

A sixth lens, the sixth lens has a negative refractive power, and the side of the object near the center is a convex surface;

and a diaphragm disposed between the second lens and the third lens or between the third lens and the fourth lens;

The aperture being arranged between the second lens and the third lens or between the third lens and the fourth lens is beneficial to improve aberration and temperature drift.

The optical lens satisfies the following conditional formula:

a1*F1+a2*F2+a3*F3+a4*F4+a5*F5+a6*F6<1000;

Wherein a1, a2, a3, a4, a5, a6 are successively the thermal expansion coefficients of the first lens to the sixth lens material of the optical lens, and F1, F2, F3, F4, F5, F6 are successively the first lens of the optical lens to the focal length of the sixth lens.

After satisfying the above conditional formula, the optical lens realizes wide-angle shooting and low temperature drift effect.

Further, the lens satisfies the following conditional formula: 0.25<SSD1/SD1<0.37, wherein, SSD1 is the distance from the inflection point of the object side of the first lens off-axis to the optical axis; SD1 is the distance of the object side of the first lens Optical effective radius.

After the above conditional formula is satisfied, light from multiple angles can enter the optical system, which is conducive to good imaging.

Further, the object side of the second lens is convex, and the image side is concave.

Thereby, it is beneficial to deal with the marginal light, and the illuminance at the edge position of the optical system is improved.

Further, the lens satisfies the following conditional formula: -1.0<(R3+R4)/(R3-R4)<-0.40, wherein, R3 is the radius of curvature of the object side of the second lens, and R4 is the second The radius of curvature of the lens image side.

Thereby, it is beneficial to deal with the marginal light, and the illuminance at the edge position of the optical system is improved.

Further, the lens satisfies the following conditional formula: 0.7<F3/R5<1.2, wherein, F3 is the focal length of the third lens, and R5 is the radius of curvature of the object side surface of the third lens.

After satisfying the above conditional formula, it can help to improve the performance of the optical system.

Further, the lens satisfies the following conditional formula: -0.7<(F3+F5)/(F4+F6)<-0.1, wherein F3, F4, F5, and F6 are the third lens, the fourth lens, The focal length of the fifth lens and the sixth lens.

After the above conditional formula is met, the performance fluctuation caused by the temperature to the lens can be balanced.

Further, the lens satisfies the following conditional formula: -0.7<(R7-R8)/(R7+R8)<0.4, wherein, R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the fourth The radius of curvature of the image side of the lens.

After the above conditional formula is satisfied, the optical performance of the outer ring of the optical system can be effectively improved, and the illuminance of the peripheral field of view can be improved.

Further, the lens satisfies the following conditional formula: 1.4<F1/F6<2.0, wherein F1 is the focal length of the first lens, and F6 is the focal length of the sixth lens.

After the above conditional formula is satisfied, it is beneficial to realize a smaller temperature drift range.

Further, the lens satisfies the following conditional formula:

0.5<(CT1+CT5)/(CT2+CT4)<1.0, wherein CT1 is the distance on the optical axis from the center of the first lens to the center of the second lens, and CT2 is the distance from the center of the second lens to the center of the second lens The distance from the center of the third lens on the optical axis, CT4 is the distance from the center of the fourth lens to the center of the fifth lens on the optical axis, and CT5 is the distance from the center of the fifth lens to the center of the sixth lens. distance on the optical axis.

After the above conditional formula is satisfied, the optical system has better stability characteristics, and the influence of distortion on the lens can be reduced.

Further, the first lens to the sixth lens satisfy the aspheric lens formula, wherein the aspheric coefficient satisfies the following equation:

Z＝cy ² /[1+{1-(1+k)c ² y ² } ^1/2 ]+A4y ⁴ +A6y ⁶ +A8y ⁸ +A10y ¹⁰

+A12y ¹² +A14y ¹⁴ +A16y ¹⁶

Among them, Z is the sagittal height of the aspheric surface, c is the paraxial curvature of the aspheric surface, y is the lens aperture, k is the conic coefficient, A4 is the 4th aspheric coefficient, A6 is the 6th aspheric coefficient, A8 is the 8th aspheric coefficient, A10 is the 10th aspheric coefficient, A12 is the 12th aspheric coefficient, A14 is the 14th aspheric coefficient, and A16 is the 16th aspheric coefficient.

After the above expression is satisfied, the ability to correct aberrations that cannot be achieved by traditional spherical lenses can be realized, and the shooting effect of the lens can be improved.

The beneficial effects of the present invention are: an optical lens provided by the present invention is mainly composed of six aspheric lenses, and through reasonable matching of optical power and surface shape and rational configuration of parameters, the lens has stable characteristics under complex environmental conditions , has a good temperature drift effect (structural compensation), maintains a good imaging effect in high and low temperature environments while achieving a wide angle, and can improve the influence of distortion on the lens, improve the illumination of the lens, and achieve high-quality imaging.

Description of drawings

Fig. 1 is the structural representation of the optical lens in the embodiment 1 of the present invention;

Fig. 2 is the distortion curve diagram of the optical lens of embodiment 1 of the present invention;

Fig. 3 is the illuminance curve figure of the optical lens of embodiment 1 of the present invention;

Fig. 4 is the 20 degree centigrade MTF graph of the optical lens of embodiment 1 of the present invention;

Fig. 5 is the -20 degree centigrade MTF graph of the optical lens of embodiment 1 of the present invention;

Fig. 6 is the 60 degree centigrade MTF graph of the optical lens of embodiment 1 of the present invention;

7 is a schematic structural view of the optical lens in Embodiment 2 of the present invention;

Fig. 8 is the distortion curve diagram of the optical lens of embodiment 2 of the present invention;

Fig. 9 is the illuminance curve diagram of the optical lens of embodiment 2 of the present invention;

Fig. 10 is the 20 degree centigrade MTF graph of the optical lens of embodiment 2 of the present invention;

Fig. 11 is the -20 degree centigrade MTF curve diagram of the optical lens of embodiment 2 of the present invention;

Fig. 12 is the 60 degree centigrade MTF curve diagram of the optical lens of embodiment 2 of the present invention;

13 is a schematic structural view of the optical lens in Embodiment 3 of the present invention;

Fig. 14 is a distortion curve diagram of the optical lens of Embodiment 3 of the present invention;

Fig. 15 is the illuminance curve diagram of the optical lens of embodiment 3 of the present invention;

Fig. 16 is the 20 degree centigrade MTF curve diagram of the optical lens of embodiment 3 of the present invention;

Fig. 17 is the -20 degree centigrade MTF curve diagram of the optical lens of embodiment 3 of the present invention;

FIG. 18 is a 60°C MTF curve of the optical lens according to Example 3 of the present invention.

In the figure: first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, first lens object side S1, first lens image side S2, second lens Object side S3, second lens image side S4, third lens object side S5, third lens image side S6, fourth lens object side S7, fourth lens image side S8, fifth lens object side S9, fifth lens image Side S10, object side S11 of the sixth lens, image side S12 of the sixth lens, diaphragm S13, filter I7.

Detailed ways

In order to better explain the present invention and facilitate understanding, the present invention will be described in detail below through specific embodiments in conjunction with the accompanying drawings.

Example 1

As shown in Figure 1, the present embodiment provides an optical lens, which sequentially includes a first lens L1, a second lens L2, a diaphragm S13, a third lens L3, a first lens L3, and an optical lens along the optical axis from the object side to the image side. Four lenses L4, fifth lens L5 and sixth lens L6. Wherein, the first lens L1 has a negative refractive power, the object side S1 has an inflection point, the object side near the center is a concave surface, and the image side S2 is a concave surface. The second lens L2 has positive refractive power. The third lens L3 has positive refractive power, the object side S5 is convex, and the image side S6 is convex. Fourth lens L4 has negative refractive power. The fifth lens L5 has positive refractive power, and the image side S10 is convex. The sixth lens L6 has a negative refractive power, and the object side S11 is convex near the center. The lens also includes a filter I7, and the filter I7 is arranged between the sixth lens L6 and the image plane.

Table 1 shows the surface type, curvature radius, thickness and material of each lens of the optical lens of Example 1. Wherein, the units of the radius of curvature and the thickness are both millimeters (mm).

Please refer to the following table for the design parameters of the lens group of the present embodiment 1:

The basic parameter list of each lens of the zoom lens involved in the embodiment 1 of table 1

The aspheric coefficient table of each lens in the embodiment 1 of table 2

The value table of each conditional expression of the zoom lens involved in the embodiment 1 of table 3

According to the structural characteristics and material characteristics of the lenses shown in Table 1, Table 2 and Figure 1, the lens shown in Example 1 has a smaller head size, and the light can converge to the image plane.

According to the distortion curves in Figure 3 and Figure 2, it clearly shows that the lens can effectively improve the influence of distortion in the optical system and achieve good imaging after meeting the requirements of the claims.

According to the illuminance curves in Table 3 and Figure 3, it clearly shows that the lens can effectively improve the illuminance of the lens after meeting the requirements of the claims, and realize clear shooting of images.

According to the MTF curves in Table 3, Figure 4, Figure 5 and Figure 6, it clearly shows that the lens can still achieve good imaging at different temperatures.

According to the above information, the optical lens has the characteristics of small head, super wide angle, little influence of temperature, and clear image shooting.

Example 2

As shown in FIG. 7 , this embodiment provides an optical lens, which sequentially includes a first lens L1, a second lens L2, a diaphragm S13, a third lens L3, a first lens L3, and an optical lens along the optical axis from the object side to the image side. Four lenses L4, fifth lens L5 and sixth lens L6. Wherein, the first lens L1 has a negative refractive power, the object side S1 has an inflection point, the object side near the center is a concave surface, and the image side S2 is a concave surface. The second lens L2 has positive refractive power. The third lens L3 has positive refractive power, the object side S5 is convex, and the image side S6 is convex. Fourth lens L4 has negative refractive power. The fifth lens L5 has positive refractive power, and the image side S10 is convex. The sixth lens L6 has a negative refractive power, and the object side S11 is convex near the center. The lens also includes a filter I7, and the filter I7 is arranged between the sixth lens L6 and the image plane.

Table 4 shows the surface type, curvature radius, thickness and material of each lens of the optical lens of Example 2. Wherein, the units of the radius of curvature and the thickness are both millimeters (mm).

Please refer to the following table for the design parameters of the lens group of the present embodiment 2:

The basic parameter list of each lens of the zoom lens involved in the embodiment 2 of table 4

The aspheric coefficient table of each lens in the embodiment 2 of table 5

The value list of each conditional expression of the zoom lens involved in the embodiment 2 of table 6

According to the structural characteristics and material characteristics of the lens shown in Table 4, Table 5 and Figure 7, the lens shown in Example 2 has a smaller head size, and the light can converge to the image plane.

According to the distortion curves in Table 6 and Figure 8, it clearly shows that the lens can effectively improve the influence of distortion in the optical system and achieve good imaging after meeting the requirements of the claims.

According to the illuminance curves in Table 6 and Figure 9, it clearly shows that the lens can effectively improve the illuminance of the lens after meeting the requirements of the claims, and achieve clear image shooting.

According to the MTF curves in Table 6, Figure 10, Figure 11 and Figure 12, it clearly shows that the lens can still achieve good imaging at different temperatures.

According to the above information, the optical lens has the characteristics of small head, super wide angle, little influence of temperature, and clear image shooting.

Example 3

As shown in FIG. 13 , this embodiment provides an optical lens, which sequentially includes a first lens L1, a second lens L2, a third lens L3, a diaphragm S13, a first Four lenses L4, fifth lens L5 and sixth lens L6. Wherein, the first lens L1 has a negative refractive power, the object side S1 has an inflection point, the object side near the center is a concave surface, and the image side S2 is a concave surface. The second lens L2 has positive refractive power. The third lens L3 has positive refractive power, the object side S5 is convex, and the image side S6 is convex. Fourth lens L4 has negative refractive power. The fifth lens L5 has positive refractive power, and the image side S10 is convex. The sixth lens L6 has a negative refractive power, and the object side S11 is convex near the center. The lens also includes a filter I7, and the filter I7 is arranged between the sixth lens L6 and the image plane.

Table 7 shows the surface type, curvature radius, thickness and material of each lens of the optical lens of Example 3. Wherein, the units of the radius of curvature and the thickness are both millimeters (mm).

Please refer to the following table for the design parameters of the lens group of the present embodiment 3:

The basic parameter list of each lens of the zoom lens involved in the embodiment 3 of table 7

The aspheric coefficient table of each lens in table 8 embodiment 3

The value list of each conditional expression of the zoom lens involved in the embodiment 3 of table 9

According to the structural and material characteristics of the lenses shown in Table 7, Table 8 and Figure 13, the lens shown in Example 3 has a smaller head size, and the light can converge to the image plane.

According to the distortion curves in Table 9 and Figure 14, it clearly shows that the lens can effectively improve the influence of distortion in the optical system and achieve good imaging after meeting the requirements of the claims.

According to the illuminance curves in Table 9 and Figure 15, it clearly shows that the lens can effectively improve the illuminance of the lens after meeting the requirements of the claims, and achieve clear image shooting.

According to the MTF curves in Table 9, Figure 16, Figure 17 and Figure 18, it clearly shows that the lens can still achieve good imaging at different temperatures.

According to the above information, the optical lens has the characteristics of small head, super wide angle, little influence of temperature, and clear image shooting.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to alterations, modifications, substitutions and variations.

Claims (10)

1. an optical lens, is characterized in that, described optical lens is made of six lens, along optical axis from object side to image side successively: The first lens, the first lens has a negative refractive power, the object side has an inflection point, the object side is concave near the center, and the image side is concave; a second lens having a positive refractive power; The third lens, the third lens has positive refractive power, the object side is convex, and the image side is convex; a fourth lens, the fourth lens having a negative refractive power; The fifth lens, the fifth lens has positive refractive power, and the image side is convex; A sixth lens, the sixth lens has a negative refractive power, and the side of the object near the center is a convex surface; and a diaphragm disposed between the second lens and the third lens or between the third lens and the fourth lens; The optical lens satisfies the following conditional formula: a1*F1+a2*F2+a3*F3+a4*F4+a5*F5+a6*F6<1000; Wherein a1, a2, a3, a4, a5, a6 are successively the thermal expansion coefficients of the first lens to the sixth lens material of the optical lens, and F1, F2, F3, F4, F5, F6 are successively the first lens of the optical lens to the focal length of the sixth lens. 2. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: 0.25<SSD1/SD1<0.37 Wherein, SSD1 is the distance from the inflection point off-axis of the object side of the first lens to the optical axis, and SD1 is the optical effective radius of the object side of the first lens. 3. The optical lens according to claim 1, wherein the object side of the second lens is convex, and the image side is concave. 4. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: -1.0<(R3+R4)/(R3-R4)<-0.40 Wherein, R3 is the radius of curvature of the object side of the second lens, and R4 is the radius of curvature of the image side of the second lens. 5. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: 0.7<F3/R5<1.2 Wherein, F3 is the focal length of the third lens, and R5 is the radius of curvature of the object side surface of the third lens. 6. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: -0.7<(F3+F5)/(F4+F6)<-0.1 Wherein, F3, F4, F5, and F6 are focal lengths of the third lens, the fourth lens, the fifth lens, and the sixth lens in sequence. 7. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: -0.7<(R7-R8)/(R7+R8)<0.4 Wherein, R7 is the radius of curvature of the object side of the fourth lens, and R8 is the radius of curvature of the image side of the fourth lens. 8. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: 1.4<F1/F6<2.0 Wherein, F1 is the focal length of the first lens, and F6 is the focal length of the sixth lens. 9. optical lens as claimed in claim 1, is characterized in that, described optical lens satisfies the following conditional formula: 0.5<(CT1+CT5)/(CT2+CT4)<1.0 Wherein, CT1 is the distance on the optical axis from the center of the first lens to the center of the second lens, CT2 is the distance on the optical axis from the center of the second lens to the center of the third lens, and CT4 is the distance from the center of the second lens to the center of the third lens. The distance on the optical axis from the center of the fourth lens to the center of the fifth lens, CT5 is the distance on the optical axis from the center of the fifth lens to the center of the sixth lens. 10. optical lens as claimed in claim 1, is characterized in that, described first lens satisfies aspheric lens formula to described the 6th lens, and wherein aspheric coefficient satisfies following equation: Z＝cy ² /[1+{1-(1+k)c ² y ² } ^1/2 ]+A4y ⁴ +A6y ⁶ +A8y ⁸ +A10y ¹⁰ +A12y ¹² +A14y ¹⁴ +A16y ¹⁶ Among them, Z is the sagittal height of the aspheric surface, c is the paraxial curvature of the aspheric surface, y is the lens aperture, k is the conic coefficient, A4 is the 4th aspheric coefficient, A6 is the 6th aspheric coefficient, A8 is the 8th aspheric coefficient, A10 is the 10th aspheric coefficient, A12 is the 12th aspheric coefficient, A14 is the 14th aspheric coefficient, and A16 is the 16th aspheric coefficient.

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