Optical lens

Abstract

The application discloses an optical lens, which comprises, along an optical axis from an object side to an imaging surface, a first lens with positive focal power, wherein the object side surface of the first lens is a convex surface; a second lens with positive focal power, wherein the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; a third lens with negative focal power, wherein the image side surface of the third lens is a concave surface; a voltage-driven zoom lens; a fourth lens with negative focal power, wherein the object side surface and the image side surface of the fourth lens are both concave surfaces; and a fifth lens with positive focal power, wherein the object side surface and the image side surface of the fifth lens are both convex surfaces; wherein the voltage-driven zoom lens is provided with a diaphragm. The optical lens has the advantages of fast focusing, small size, high image quality and the like.

Description

Technical Field

[0001] This invention relates to the field of imaging lens technology, and in particular to an optical lens. Background Technology

[0002] Since 2010, my country has experienced explosive growth in the field of machine vision. With the development of camera technology, camera modules have gradually evolved from fixed-focus systems with limited camera conditions to zoom systems that can switch between different camera conditions.

[0003] Current zoom systems typically use a voice coil motor to drive certain lenses, causing relative movement to change the distance between them and thus altering the focal length. This allows for autofocus at various shooting distances, ensuring consistent image quality while adapting to different object distances, depths of field, and shooting range requirements. Furthermore, to achieve even higher image quality, current optical systems are increasingly using image sensors with higher resolution, such as CCDs or CMOS sensors.

[0004] However, in order to match the image quality of the zoom system with the high pixel count of the image sensor, it is usually necessary to add lenses, which increases the weight and size of the lens. At the same time, for high-speed or precision applications that require rapid refocusing, existing zoom systems have difficulty capturing sharp and accurate images, i.e., slow focusing speed and low image quality. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide an optical lens that has at least the advantages of fast focusing, small size, and high image quality.

[0006] The present invention achieves the above objectives through the following technical solutions.

[0007] This invention provides an optical lens comprising, along the optical axis from the object side to the imaging plane: a first lens with positive optical power, the object side of the first lens being convex; a second lens with positive optical power, the object side of the second lens being convex and the image side of the second lens being concave; a third lens with negative optical power, the image side of the third lens being concave; a voltage-driven zoom lens; a fourth lens with negative optical power, the object side and image side of the fourth lens being both concave; and a fifth lens with positive optical power, the object side and image side of the fifth lens being both convex; wherein the voltage-driven zoom lens contains an aperture stop.

[0008] Compared with existing technologies, the optical lens provided by this invention can effectively avoid lens sensitivity problems caused by excessive concentration of optical focal length by reasonably allocating the optical power of each lens, effectively balance chromatic aberration and distortion, improve image quality, and at the same time ensure that the length of the optical system is shortened as much as possible while maintaining a sufficiently large effective focal length, thereby achieving lens miniaturization. Attached Figure Description

[0009] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0010] Figure 1 This is a schematic diagram of the structure of an optical lens provided in the first embodiment of the present invention;

[0011] Figure 2 A transverse chromatic aberration diagram of an optical lens provided in the first embodiment of the present invention;

[0012] Figure 3 The MTF diagram of the optical lens provided in the first embodiment of the present invention;

[0013] Figure 4 The distortion diagram of the optical lens provided in the first embodiment of the present invention;

[0014] Figure 5 This is a schematic diagram of the structure of an optical lens provided in the second embodiment of the present invention;

[0015] Figure 6 A transverse chromatic aberration diagram of an optical lens provided in the second embodiment of the present invention;

[0016] Figure 7 The MTF diagram of the optical lens provided in the second embodiment of the present invention;

[0017] Figure 8 The distortion diagram of the optical lens provided in the second embodiment of the present invention;

[0018] Figure 9 This is a schematic diagram of the structure of an optical lens provided in the third embodiment of the present invention;

[0019] Figure 10 A transverse chromatic aberration diagram of an optical lens provided in the third embodiment of the present invention;

[0020] Figure 11 The MTF diagram of the optical lens provided in the third embodiment of the present invention;

[0021] Figure 12 The distortion diagram of the optical lens provided in the third embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be thorough and complete.

[0023] 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 to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Throughout this specification, the same reference numerals refer to the same elements.

[0024] The present invention proposes an optical lens comprising, in sequence along the optical axis from the object side to the imaging plane: a first lens, a second lens, a third lens, a voltage-driven zoom lens, a fourth lens, a fifth lens, and a filter, wherein the optical centers of each lens are located on the same straight line.

[0025] Among them, the voltage-driven zoom lens has an aperture stop;

[0026] The first lens has positive optical power, the object side of the first lens is convex, and the image side of the first lens is either convex or concave.

[0027] The second lens has positive optical power, the object side of the second lens is convex, and the image side of the second lens is concave.

[0028] The third lens has negative optical power, the object side of the third lens is convex or concave, and the image side of the third lens is concave.

[0029] The fourth lens has negative optical power, and both the object-side and image-side surfaces of the fourth lens are concave.

[0030] The fifth lens has positive optical power, and both the object side and the image side of the fifth lens are convex.

[0031] The optical lens provided by this invention effectively reduces the weight and size of the lens through the reasonable combination of lens elements; at the same time, it uses a voltage-driven zoom lens, which can maintain good image quality at different object distances and can ensure that the voltage-driven zoom lens can be adjusted under different temperature conditions to obtain good image quality.

[0032] In some embodiments, the optical lens satisfies the following condition:

[0033] 0.1 < CT3 / CT13 < 0.4; (1)

[0034] Wherein, CT3 represents the air gap between the third lens and the voltage-driven zoom lens, and CT13 represents the total optical length between the object side of the first lens and the voltage-driven zoom lens. Satisfying the above condition (1) not only facilitates the installation of the voltage-driven zoom lens, but also ensures that the optical lens has good imaging quality.

[0035] In some embodiments, the optical lens satisfies the following condition:

[0036] 2.5 <TTL / IH<4.0; (2)

[0037] Where TTL represents the total optical length of the optical lens, and IH represents the image height of the optical lens. When the TTL / IH value exceeds the upper limit, the total length of the lens is too long, making it difficult to meet the requirements of miniaturization; or, if the total lens length is small enough, the target surface is too small, making it difficult to match a larger chip. When the TTL / IH value exceeds the lower limit, due to the excessive optical focal length of each lens, lens aberration correction is difficult, and the resolving power is significantly reduced.

[0038] In some embodiments, the optical lens satisfies the following condition:

[0039] 3 <f / EPD<4; (3)

[0040] Where f represents the effective focal length of the optical lens, and EPD represents the aperture of the optical lens. By satisfying the above condition (3), it is possible to ensure both good image quality and miniaturization of the optical lens.

[0041] In some embodiments, the optical lens satisfies the following condition:

[0042] -3.5 < f1 / f3 < -1.0; (4)

[0043] Where f1 represents the effective focal length of the first lens, and f3 represents the effective focal length of the third lens. Satisfying the above condition (4) ensures that the distortion of the optical lens increases in the positive direction, and that the correction of the distortion is not difficult.

[0044] In some embodiments, the optical lens satisfies the following condition:

[0045] -3<(R3+R4) / (R3-R4)<-1; (5)

[0046] Where R3 represents the radius of curvature of the object side of the second lens, and R4 represents the radius of curvature of the image side of the second lens. Satisfying the above condition (5) can reduce the eccentricity sensitivity of the second lens and improve the product yield.

[0047] In some embodiments, the optical lens satisfies the following condition:

[0048] -0.8 <f3 / f<-0.1; (6)

[0049] Where f3 represents the effective focal length of the third lens, and f represents the effective focal length of the optical lens. Satisfying the above condition (6) can effectively correct the field curvature of the optical lens, improve resolution, and enhance the brightness of the outer edge field of view.

[0050] In some embodiments, the optical lens satisfies the following condition:

[0051] 1 <Vd5-Vd4<30; (7)

[0052] -15 <f4 / Nd4<-3; (8)

[0053] 3 <f5 / Nd5<8; (9)

[0054] Wherein, Vd4 represents the Abbe number of the fourth lens, Vd5 represents the Abbe number of the fifth lens, Nd4 represents the refractive index of the fourth lens, Nd5 represents the refractive index of the fifth lens, f4 represents the effective focal length of the fourth lens, and f5 represents the effective focal length of the fifth lens. By satisfying the above conditions (7), (8), and (9), and by selecting appropriate lens materials, the fourth and fifth lenses can bear part of the optical power of the optical system, which helps to correct aberrations and improve resolution.

[0055] In some embodiments, the optical lens satisfies the following condition:

[0056] 1.2

[0057] Where U represents the voltage of the voltage-driven zoom lens at the working object distance, and f represents the effective focal length of the optical lens. By satisfying the above condition (10), good image quality can be achieved under different working object distances and different temperature environments.

[0058] In some embodiments, the optical lens satisfies the following condition:

[0059] 27.0mm < TTL < 36.0mm; (11)

[0060] 21.3 mm ≤ f ≤ 25.8 mm; (12)

[0061] ​Where TTL represents the total optical length of the optical lens, and f represents the effective focal length of the optical lens. By satisfying the above conditions (11) and (12), the total optical length and effective focal length of the optical lens can be reasonably controlled, thereby achieving miniaturization of the optical lens.

[0062] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0063] First Embodiment

[0064] Please see Figure 1 The above is a schematic diagram of the structure of the optical lens 100 provided in the first embodiment of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a voltage-driven zoom lens VFL, a fourth lens L4, a fifth lens L5, and a filter L6, and the optical centers of each lens are located on the same straight line.

[0065] The first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens L2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. An aperture stop is provided inside the voltage-driven zoom lens VFL. The fourth lens L4 has negative optical power, with both its object-side surface S7 and image-side surface S8 being concave. The fifth lens L5 has positive optical power, with both its object-side surface S9 and image-side surface S10 being convex. The filter L6 has an object-side surface S11 and an image-side surface S12.

[0066] The relevant parameters of each lens element of the optical lens 100 provided in this embodiment are shown in Table 1.

[0067] Table 1

[0068]

[0069] Please see Figure 2 The figure shows the chromatic aberration diagram of the optical lens 100 in this embodiment. As can be seen from the figure, the offset of the chromatic aberration is controlled within ±1 micrometer, indicating that the optical lens 100 can effectively correct the chromatic aberration.

[0070] Please see Figure 3 The figure shows the MTF diagram of the optical lens 100 in this embodiment. As can be seen from the figure, the MTF value of the lens is above 0.55 at a spatial frequency of 125 lp / mm, indicating that the optical lens 100 has a high resolution.

[0071] Please see Figure 4 The figure shows the F-Theta distortion of the optical lens 100 in this embodiment. As can be seen from the figure, the F-Theta distortion of the lens is small and less than 2%, indicating that the distortion of the optical lens 100 has been well corrected.

[0072] Second Embodiment

[0073] Please see Figure 5 The above is a schematic diagram of the structure of the optical lens 200 provided in the first embodiment of the present invention. The optical lens 200 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a voltage-driven zoom lens VFL, a fourth lens L4, a fifth lens L5, and a filter L6, and the optical centers of each lens are located on the same straight line.

[0074] The first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens L2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. An aperture stop is provided inside the voltage-driven zoom lens VFL. The fourth lens L4 has negative optical power, with both its object-side surface S7 and image-side surface S8 being concave. The fifth lens L5 has positive optical power, with both its object-side surface S9 and image-side surface S10 being convex. The filter L8 has an object-side surface S11 and an image-side surface S12.

[0075] The relevant parameters of each lens element of the optical lens 200 provided in this embodiment are shown in Table 2.

[0076] Table 2

[0077]

[0078]

[0079] Please see Figure 6 The figure shows the chromatic aberration diagram of the optical lens 200 in this embodiment. As can be seen from the figure, the offset of the chromatic aberration is controlled within ±1.2 micrometers, indicating that the optical lens 200 can effectively correct the chromatic aberration.

[0080] Please see Figure 7The figure shows the MTF diagram of the optical lens 200 in this embodiment. As can be seen from the figure, the MTF value of the lens is above 0.55 at a spatial frequency of 125 lp / mm, indicating that the optical lens 200 has a high resolution.

[0081] Please see Figure 8 The figure shows the F-Theta distortion of the optical lens 200 in this embodiment. As can be seen from the figure, the F-Theta distortion of the lens is small and less than 5%, indicating that the distortion of the optical lens 200 has been well corrected.

[0082] Third Embodiment

[0083] Please see Figure 9 The above is a schematic diagram of the structure of the optical lens 300 provided in the first embodiment of the present invention. The optical lens 300 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, a voltage-driven zoom lens VFL, a fourth lens L4, a fifth lens L5, and a filter L6, and the optical centers of each lens are located on the same straight line.

[0084] The first lens L1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens L2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens L3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. An aperture stop is provided inside the voltage-driven zoom lens VFL. The fourth lens L4 has negative optical power, with both its object-side surface S7 and image-side surface S8 being concave. The fifth lens L5 has positive optical power, with both its object-side surface S9 and image-side surface S10 being convex. The filter L8 has an object-side surface S11 and an image-side surface S12.

[0085] The relevant parameters of each lens element of the optical lens 300 provided in this embodiment are shown in Table 3.

[0086] Table 3

[0087]

[0088] Please see Figure 10 The figure shows the chromatic aberration diagram of the optical lens 300 in this embodiment. As can be seen from the figure, the offset of the chromatic aberration is controlled within ±1 micrometer, indicating that the optical lens 300 can effectively correct the chromatic aberration.

[0089] Please see Figure 11The figure shows the MTF diagram of the optical lens 300 in this embodiment. As can be seen from the figure, the MTF value of the lens is above 0.3 at a spatial frequency of 125 lp / mm, indicating that the optical lens 300 has a high resolution.

[0090] Please see Figure 12 The figure shows the F-Theta distortion of the optical lens 300 in this embodiment. As can be seen from the figure, the F-Theta distortion of the lens is small and less than 3%, indicating that the distortion of the optical lens 300 has been well corrected.

[0091] Please refer to Table 4, which shows the optical characteristics of the optical lenses provided in the three embodiments above, including the total optical length TTL, aperture number F#, effective focal length f, field of view FOV, and image height IH of the optical lens, as well as the relevant values ​​corresponding to each condition in the above conditional expressions.

[0092] Table 4

[0093]

[0094]

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens, five pieces of lenses and a piece of voltage-driven zoom lens, characterized in that, sequentially include from the object side to the imaging plane along the optical axis: a first lens with positive refractive power, an object side surface of the first lens being convex; a second lens with positive refractive power, an object side surface of the second lens being convex, an image side surface of the second lens being concave; a third lens with negative refractive power, an image side surface of the third lens being concave; a voltage-driven zoom lens; a fourth lens with negative refractive power, both an object side surface and an image side surface of the fourth lens being concave; a fifth lens with positive refractive power, both an object side surface and an image side surface of the fifth lens being convex; the optical lens satisfies the following conditional expression: 21.3 mm ≤ f ≤ 25.8 mm; wherein f represents an effective focal length of the optical lens.

2. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 0.1 < CT3 / CT13 < 0.4; wherein CT3 represents an air gap between the third lens and the voltage-driven zoom lens, and CT13 represents an optical total length between the object side surface of the first lens and the voltage-driven zoom lens.

3. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 2.5 < TTL / IH < 4.0; wherein TTL represents an optical total length of the optical lens, and IH represents an image height of the optical lens.

4. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 3 < f / EPD < 4; wherein f represents an effective focal length of the optical lens, and EPD represents an entrance pupil diameter of the optical lens.

5. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: -3.5 < f1 / f3 < -1.0; wherein f1 represents an effective focal length of the first lens, and f3 represents an effective focal length of the third lens.

6. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: -3 < (R3+R4) / (R3-R4) < -1; wherein R3 represents a curvature radius of the object side surface of the second lens, and R4 represents a curvature radius of the image side surface of the second lens.

7. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: -0.8 < f3 / f < -0.1; wherein f3 represents an effective focal length of the third lens, and f represents an effective focal length of the optical lens.

8. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 1 < Vd5-Vd4 < 30; -15 mm < f4 / Nd4 < -3 mm; 3 mm < f5 / Nd5 < 8 mm; wherein Vd4 represents an Abbe number of the fourth lens, Vd5 represents an Abbe number of the fifth lens, Nd4 represents a refractive index of the fourth lens, Nd5 represents a refractive index of the fifth lens, f4 represents an effective focal length of the fourth lens, and f5 represents an effective focal length of the fifth lens.

9. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 1.2 V / mm < U / f < 3.0 V / mm; wherein U represents a voltage of the voltage-driven zoom lens at a working object distance, and f represents an effective focal length of the optical lens.

10. The optical lens of claim 1, wherein, the voltage-driven zoom lens is provided with a diaphragm.

11. The optical lens of claim 1, wherein, the optical lens satisfies the following conditional expression: 27.0 mm < TTL < 36.0 mm; 21.8 mm ≤ f ≤ 25.3 mm; wherein TTL represents an optical total length of the optical lens, and f represents an effective focal length of the optical lens.

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