Large-aperture TOF lens and electronic equipment

Abstract

The utility model discloses a large aperture TOF lens and an electronic device. The large aperture TOF lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along an optical axis from an object side to an image side. The lens provided by the utility model adopts a seven-piece design, and a TOF lens with a focal length of 11.5 mm is realized. The maximum outer diameter of the lens is smaller than 16mm, the total optical length is smaller than 22mm, and the overall structure is compact. The F number of the lens is 1.0, the relative illumination of the full view field is greater than 60%, and the energy utilization rate is effectively improved. The lens can be matched with a 1 / 2 inch sensor for use, and the maximum field angle of the lens can reach 39 degrees. The optical distortion of the lens is less than 1.8%, the image restoration degree is high, and the difficulty of image recognition is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to TOF lens technical field especially, relates to a big aperture TOF lens and electronic equipment. BACKGROUND

[0002] TOF technology is utilizing laser to emit pulse laser, then recording the time of light beam from laser to reach detection lens after reflecting through object surface, thereby deducing the corresponding distance of detection lens to object, wherein detection lens is usually also called TOF lens. Because of its high-precision positioning, measurement and three-dimensional imaging ability, TOF lens has wide application in virtual reality, face recognition, smart home and unmanned driving etc. But most of the existing TOF lens has one or more of the following defects:

[0003] Firstly, the field of view of the existing TOF lens is small, the lens observation range is small, and the capture frame is insufficient;

[0004] Secondly, the existing TOF lens has small lens aperture, low energy utilization rate and poor low-light effect;

[0005] Thirdly, the optical distortion of the existing TOF lens is large, the image restoration degree is poor, and the image recognition difficulty is increased. INVENTION CONTENTS

[0006] Therefore, the purpose of the utility model is to provide a big aperture TOF lens and electronic equipment. The lens can at least solve the technical defects mentioned in the background technology.

[0007] According to one aspect of the utility model, a big aperture TOF lens is provided, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in order along the optical axis from the object side to the image side;

[0008] The first lens has positive refractive power, the object side surface of the first lens is convex, and the image side surface of the first lens is convex;

[0009] The second lens has positive refractive power, the object side surface of the second lens is convex, and the image side surface of the second lens is concave;

[0010] The third lens has negative focal power, the object side surface of the third lens is convex, and the image side surface of the third lens is concave;

[0011] The fourth lens has negative focal power, the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is concave;

[0012] The fifth lens has positive focal power, the object side surface of the fifth lens is flat, and the image side surface of the fifth lens is convex;

[0013] The sixth lens has positive optical power, and the object side of the sixth lens is convex, and the image side of the sixth lens is convex.

[0014] The seventh lens has negative optical power, the object side of the seventh lens is convex, and the image side of the seventh lens is flat.

[0015] This invention utilizes a seven-element design to achieve a TOF lens with a focal length of 11.5mm. The maximum outer diameter of the lens elements is less than 16mm, and the total optical length is less than 22mm, resulting in a compact overall structure. The lens has an f / 1.0 aperture and a relative illumination greater than 60% across the entire field of view, effectively improving energy efficiency. The lens can be used with 1 / 2-inch sensors, and its maximum field of view reaches 39°. The lens exhibits optical distortion of less than 1.8%, resulting in high image fidelity and reducing the difficulty of image recognition.

[0016] According to another aspect of this invention, an electronic device is provided, comprising the aforementioned large-aperture TOF lens; and an image sensor configured to receive an image formed by the large-aperture TOF lens. In this technical solution, the advantage of the electronic device relies on the large-aperture TOF lens, which will not be elaborated upon here. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural diagram of the optical system of the lens in Example 1.

[0019] Figure 2 This is the MTF diagram in the visible light band of Example 1.

[0020] Figure 3 The image shows the distortion and field curvature in the visible light band in Example 1.

[0021] Figure 4 This is a relative illuminance diagram of Example 1 in the visible light band.

[0022] Figure 5 This is a structural diagram of the optical system of the lens in Example 2.

[0023] Figure 6 This is the MTF diagram in the visible light band in Example 2.

[0024] Figure 7 Distortion and field curvature map in the visible light band for Example 2.

[0025] Figure 8 Relative illumination map in the visible light band for Example 2

[0026] Figure 9 It is a structure schematic view of the electronic equipment.

[0027] L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; ST, diaphragm; G, protective glass; IM A, imaging surface. DETAILED DESCRIPTION

[0028] The utility model will be described in further detail below in connection with the drawings and examples. It is particularly pointed out that the following examples are only used for illustrating the utility model, but do not limit the scope of the utility model. Similarly, the following examples are only part of the embodiments of the utility model and not all embodiments, and all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the scope of the utility model protection.

[0029] The utility model discloses a large aperture TOF lens, including the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens that are arranged in sequence along the direction of optical axis from the object side to the direction of image side, the diaphragm is established between second lens and third lens, and the protective glass is established after seventh lens.

[0030] The first lens has positive refractive power, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a convex surface.

[0031] The second lens has positive refractive power, 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.

[0032] The third lens has negative focal power, the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface.

[0033] The fourth lens has negative focal power, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface.

[0034] The fifth lens has positive focal power, the object side surface of the fifth lens is a plane, and the image side surface of the fifth lens is a convex surface.

[0035] The sixth lens has positive focal power, the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface.

[0036] The seventh lens has negative optical power, the object side of the seventh lens is convex, and the image side of the seventh lens is flat.

[0037] This invention utilizes a seven-element design to achieve a TOF lens with a focal length of 11.5mm. The maximum outer diameter of the lens elements is less than 16mm, and the total optical length is less than 22mm, resulting in a compact overall structure. The lens has an f / 1.0 aperture and a relative illumination greater than 60% across the entire field of view, effectively improving energy efficiency. The lens can be used with 1 / 2-inch sensors, and its maximum field of view reaches 39°. The lens exhibits optical distortion of less than 1.8%, resulting in high image fidelity and reducing the difficulty of image recognition.

[0038] Among them, reference Figure 1 and Figure 5 As shown in the figure. The first lens is labeled L1, the second lens is labeled L2, the third lens is labeled L3, the fourth lens is labeled L4, the fifth lens is labeled L5, the sixth lens is labeled L6, the seventh lens is labeled L7, the aperture is labeled ST, the protective glass is labeled G, and the imaging plane is labeled I MA.

[0039] As one embodiment, the lens satisfies the following relationships: 1.6 < Nd1 < 2.2; 34.5 < Vd1 < 36; where Nd1 is the refractive index of the first lens and Vd1 is the Abbe coefficient of the first lens. The beneficial effect of this embodiment is that by satisfying the above relationships, chromatic aberration can be reduced, improving image sharpness and color accuracy.

[0040] As one embodiment, the lens satisfies the following relationships: 1.7 < Nd² < 2.3; 25 < Vd² < 26; where Nd² is the refractive index of the second lens and Vd² is the Abbe coefficient of the second lens. The beneficial effect of this embodiment is that by satisfying the above relationships and rationally selecting the refractive index and Abbe coefficient, better aberration correction can be achieved without increasing the number of lenses, simplifying the lens structure and reducing manufacturing costs.

[0041] As one embodiment, the lens satisfies the following relationships: 1.2 < Nd³ < 1.8; 63.5 < Vd³ < 65; where Nd³ is the refractive index of the third lens, and Vd³ is the Abbe coefficient of the third lens. The beneficial effect of this embodiment is that by satisfying the above relationships, the refractive index between 1.2 and 1.8 can effectively control the lens thickness, while the Abbe coefficient between 63.5 and 65 can significantly reduce chromatic aberration and improve image sharpness and color accuracy.

[0042] As an embodiment, the lens satisfies the following relationship: 1.2Nd4<1.8; 63.5Vd4<65; wherein, Nd4 is the refractive index of the fourth lens, and Vd4 is the Abbe number of the fourth lens. The embodiment has the beneficial effect that by satisfying the above relationship, the refractive index between 1.2 and 1.8 can effectively control the thickness of the lens, while the Abbe number between 63.5 and 65 can significantly reduce the dispersion phenomenon, improve the clarity and color accuracy of imaging.

[0043] As an embodiment, the lens satisfies the following relationship: 1.6Nd5<2.2; 34.5Vd5<36; wherein, Nd5 is the refractive index of the fifth lens, and Vd5 is the Abbe number of the fifth lens. The embodiment has the beneficial effect that by satisfying the above relationship, reasonable refractive index and Abbe number can achieve more uniform and more accurate light spot distribution, improve the processing precision.

[0044] As an embodiment, the lens satisfies the following relationship: 1.7Nd6<2.3; 25Vd6<26; wherein, Nd6 is the refractive index of the sixth lens, and Vd6 is the Abbe number of the sixth lens. The embodiment has the beneficial effect that by satisfying the above relationship, it is helpful to control the thickness and curvature of the lens, so as to better correct aberration and improve the imaging quality.

[0045] As an embodiment, the lens satisfies the following relationship: 1.7Nd7<2.3; 25Vd7<26; wherein, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe number of the seventh lens. The embodiment has the beneficial effect that by satisfying the above relationship, it is beneficial to reduce the tail aperture of the lens.

[0046] The lens satisfies the following relationship: 0.3BFL / TTL<0.5; wherein, BFL is the optical back focal length of the lens, and TTL is the total optical length of the lens. The embodiment has the beneficial effect that by satisfying the above relationship, it is beneficial to balance the purpose of improving the relative luminance of the optical system of the lens and miniaturization design.

[0047] The utility model will be described in more detail below in conjunction with the following table. It should be noted that the following table is only a specific embodiment of the utility model, not a limiting example.

[0048] For convenience of description, surface No. 1 and surface No. 2 in the table are the object side surface and the image side surface of the first lens respectively; surface No. 3 and surface No. 4 are the object side surface and the image side surface of the second lens respectively; surface No. 5 is the surface of the diaphragm; surface No. 6 and surface No. 7 are the object side surface and the image side surface of the third lens respectively; surface No. 8 and surface No. 9 are the object side surface and the image side surface of the fourth lens respectively; surface No. 10 and surface No. 11 are the object side surface and the image side surface of the fifth lens respectively; surface No. 12 and surface No. 13 are the object side surface and the image side surface of the sixth lens respectively; surface No. 14 and surface No. 15 are the object side surface and the image side surface of the seventh lens respectively; surface No. 16 and surface No. 17 are the object side surface and the image side surface of the protective glass respectively; and surface No. 18 is the surface of the imaging plane.

[0049] The optical structure of Example 1 is shown in Fig. 1. Figure 1 The specific parameters of Example 1 are shown in Table 1. In Example 1, the focal length of the lens is f = 11.5 mm, and the total length TTL = 21.85 mm.

[0050] Table 1 - Lens parameter table of Example 1

[0051] Surface No. Surface Radius of curvature Thickness interval Refractive index Abbe number Focal length value 1 First lens 56 2.4 1.9 35.3 30 2 -49.7 0.1 3 Second lens 9.3 2.3 2 25.4 16.1 4 20.4 0.6 5 Stop Infinity 0.1 6 Third lens 92.3 0.56 1.5 64.2 -14.1 7 6.6 2.4 8 Fourth lens -8.1 0.66 1.5 64.2 -11.9 9 25.3 0.44 10 Fifth lens Infinity 2.2 1.9 35.3 13.8 11 -12.3 0.1 12 Sixth lens 35.4 2.51 2 25.4 20.8 13 -45.1 0.17 14 Seventh lens 24.6 2.7 2 25.4 25.5 15 Infinity 3.7 16 Protective glass Infinity 0.3 1.5 64.2 Infinity 17 Infinity 0.61 18 Imaging surface - -

[0052] According to Table 1, the conditional expressions of Example 1 of the present application are as follows:

[0053] (1) the refractive index of the first lens Nd1 = 1.9; and the Abbe number of the first lens Vd1 = 35.3;

[0054] (2) the refractive index of the second lens Nd2 = 2; and the Abbe number of the second lens Vd2 = 25.4;

[0055] (3) the refractive index of the third lens Nd3 = 1.5; and the Abbe number of the third lens Vd3 = 64.2;

[0056] (4) the refractive index of the fourth lens Nd4 = 1.5; and the Abbe number of the fourth lens Vd4 = 64.2;

[0057] (5) the refractive index of the fifth lens Nd5 = 1.9; and the Abbe number of the fifth lens Vd5 = 35.3;

[0058] (6) the refractive index of the sixth lens Nd6 = 2; and the Abbe number of the sixth lens Vd6 = 25.4;

[0059] (7) the refractive index of the seventh lens Nd7 = 2; and the Abbe number of the seventh lens Vd7 = 25.4.

[0060] The optical structure of Example 2 is shown in Fig. 2. Figure 5The specific parameters of this embodiment 2 are shown in Table 2 below. In this embodiment 2, the focal length of the lens f = 11.6 mm, and the total length TTL = 21.2 mm.

[0061] Table 2 - Lens parameter table of embodiment 2

[0062] Surface No. Surface Radius of curvature Thickness interval Refractive index Abbe number Focal length value 1 First lens 33.1 2.2 1.9 35.3 29.4 2 -119.9 0.1 3 Second lens 9.3 2.3 2 25.4 16.5 4 19.6 0.59 5 Stop Infinity 0.18 6 Third lens 40.7 0.58 1.5 64.2 -13.8 7 6 2.8 8 Fourth lens -6.9 0.6 1.5 64.2 -11.8 9 49 0.34 10 Fifth lens -108.5 2.2 1.9 35.3 13.5 11 -10.8 0.06 12 Sixth lens 32.9 1.72 2 25.4 13.5 13 -50 0.13 14 Seventh lens 25.1 2.7 2 25.4 26 15 Infinity 0.1 16 Protective glass Infinity 0.3 1.5 64.2 Infinity 17 Infinity 4.3 18 Imaging surface - -

[0063] According to Table 2, the conditional expressions of the embodiment 2 of the present application are as follows:

[0064] (1) the refractive index of the first lens Nd1 = 1.9; the Abbe number of the first lens Vd1 = 35.3;

[0065] (2) the refractive index of the second lens Nd2 = 2; the Abbe number of the second lens Vd2 = 25.4;

[0066] (3) the refractive index of the third lens Nd3 = 1.5; the Abbe number of the third lens Vd3 = 64.2;

[0067] (4) the refractive index of the fourth lens Nd4 = 1.5; the Abbe number of the fourth lens Vd4 = 64.2;

[0068] (5) the refractive index of the fifth lens Nd5 = 1.9; the Abbe number of the fifth lens Vd5 = 35.3;

[0069] (6) the refractive index of the sixth lens Nd6 = 2; the Abbe number of the sixth lens Vd6 = 25.4;

[0070] (7) the refractive index of the seventh lens Nd7 = 2; the Abbe number of the seventh lens Vd7 = 25.4.

[0071] Table 3 - Lens parameter table of each type

[0072] Example 1 Example 2 Focal length f 11.5 11.6 Back focal length BFL 4.61 4.7 BFL / f 0.400869565 0.405172414 Image surface y 8 8 y / f 0.695652174 0.689655172 Total length TTL 21.85 21.2 BFL / TTL 0.210983982 0.221698113

[0073] The following is an explanation of each figure in embodiments 1 to 2:

[0074] Figure 2 is the MTF diagram of embodiment 1 in the visible light band. As can be seen from the figure, the contrast of the full field of view is greater than 0.52 at 25 l p / mm, the imaging quality is uniform, and the resolving power is high.

[0075] Figure 3 is the distortion and field curvature diagram of embodiment 1 in the visible light band. As can be seen from the figure, the optical distortion is less than 1.6%, the field curvature is well controlled, and the image restoration degree is high.

[0076] Figure 4It is a relative luminance diagram in the visible light band in Example 1. As can be seen from the diagram, the relative luminance in the full field of view is greater than 60%, and the energy utilization rate is high.

[0077] Figure 6 It is an MTF diagram in the visible light band in Example 2. As can be seen from the diagram, the contrast in the full field of view is greater than 0.55 at 25 lp / mm, the imaging quality is uniform, and the resolving power is high.

[0078] Figure 7 It is a distortion diagram in the visible light band in Example 2. As can be seen from the diagram, the optical distortion is less than 1.8%, the field curvature is well controlled, and the image restoration degree is high.

[0079] Figure 8 It is a relative luminance diagram in the visible light band in Example 2. As can be seen from the diagram, the relative luminance in the full field of view is greater than 60%, and the energy utilization rate is high.

[0080] On the other hand, referring now to Figure 9 a structural diagram of an electronic device A according to the present application will be given. Figure 9 is a schematic diagram of an electronic device (camera) to which any one of the large-aperture TOF lenses according to Examples 1 to 2 is applied as an image pickup optical system.

[0081] In Figure 9 , reference sign A2 denotes an electronic device main body, and reference sign Al denotes an image pickup optical system (interchangeable lens) including any one of the large-aperture TOF lenses according to Examples 1 to 3. Reference sign A3 denotes an image sensor (photoelectric conversion element) such as a CMOS image sensor or a CCD image sensor, which is built into the camera main body A2 and receives light (optical image formed through the image pickup optical system Al) from the image pickup optical system Al and performs photoelectric conversion.

[0082] By applying any one of the large-aperture TOF lenses according to Examples 1 to 2 to an electronic device such as a digital still camera, an electronic device having high optical performance can be obtained.

[0083] Each example can provide an electronic device having high optical performance.

[0084] While the present application has been described with reference to typical embodiments, it is to be understood that the application is not limited to the disclosed typical embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all the modifications and equivalent structures and functions.

Claims

1. A large-aperture TOF lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side; The first lens has positive diopter, the object side of the first lens is convex, and the image side of the first lens is convex. The second lens has positive diopter, the object side of the second lens is convex, and the image side of the second lens is concave. The third lens has negative optical power, the object side of the third lens is convex, and the image side of the third lens is concave. The fourth lens has negative optical power, and the object side of the fourth lens is concave, and the image side of the fourth lens is concave. The fifth lens has positive optical power, the object side of the fifth lens is a plane, and the image side of the fifth lens is a convex surface; The sixth lens has positive optical power, and the object side of the sixth lens is convex, and the image side of the sixth lens is convex. The seventh lens has negative optical power, its object-side surface is convex, and its image-side surface is planar. 。 2. The large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.6<Nd1<2.2; 34.5<Vd1<36; Wherein, Nd1 is the refractive index of the first lens, and Vd1 is the Abbe coefficient of the first lens.

3. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.7<Nd2<2.3; 25<Vd2<26; Wherein, Nd2 is the refractive index of the second lens, and Vd2 is the Abbe coefficient of the second lens.

4. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.2<Nd3<1.8; 63.5<Vd3<65; Wherein, Nd3 is the refractive index of the third lens, and Vd3 is the Abbe coefficient of the third lens.

5. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.2<Nd4<1.8; 63.5<Vd4<65; Wherein, Nd4 is the refractive index of the fourth lens, and Vd4 is the Abbe coefficient of the fourth lens.

6. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.6<Nd5<2.2; 34.5<Vd5<36; Wherein, Nd5 is the refractive index of the fifth lens, and Vd5 is the Abbe coefficient of the fifth lens.

7. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.7<Nd6<2.3; 25<Vd6<26; Wherein, Nd6 is the refractive index of the sixth lens, and Vd6 is the Abbe coefficient of the sixth lens.

8. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 1.7<Nd7<2.3; 25<Vd7<26; Wherein, Nd7 is the refractive index of the seventh lens, and Vd7 is the Abbe coefficient of the seventh lens.

9. A large-aperture TOF lens as described in claim 1, characterized in that, The lens satisfies the following relationship: 0.3 < BFL / TTL < 0.5; Where BFL is the optical rear focal length of the lens, and TTL is the optical total length of the lens.

10. An electronic device, characterized in that, A large-aperture TOF lens according to any one of claims 1-9; and An image sensor is configured to receive the image formed by the large-aperture TOF lens.

Images