Double-vision zoom macro optical system

Abstract

The utility model relates to the technical field of optical lenses, and discloses a double-vision zoom micro-distance optical system, which is sequentially provided with a first lens, a second lens and a third lens along an optical axis from an object plane to an aperture diaphragm. The first lens is a negative lens, and the concave surface of the first lens faces the image surface side; the second lens is a positive lens, and the convex surface of the second lens faces the image surface side; the third lens is a positive meniscus lens, and the concave surface of the third lens faces the image surface side; the aperture diaphragm is an exit pupil of the optical system; the aperture diaphragm is connected with a mobile phone lens or human eyes in a plug-in mode. According to the utility model, the optical system is connected with the mobile phone lens in a plug-in manner, so that the optical system can be used as a main camera of the mobile phone and can also be used for telephoto of the mobile phone; the optical system has a zoom function, so that macro shooting of the mobile phone with different distances and different multiples can be realized; the optical system also has the advantages of high light transmission, long exit pupil, low cost, low distortion and better imaging effect; the device can be connected with human eyes to serve as a magnifying lens.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to a dual-view zoom macro optical system. Background Art

[0002] Photography has become a very popular entertainment activity in today's society; with the popularization of smart phones, more and more people choose to use them for taking pictures and videos; and with the continuous development of smart phone camera technology, people have higher expectations for the quality and effect of mobile phone shooting.

[0003] Existing smart phones usually use 3 to 4 cameras to cover more lens focal lengths to meet the needs of different shooting scenarios. However, due to factors such as the size of the mobile phone, the ultra-wide-angle cropped image is often used as a macro, with a close shooting distance of about 5 cm, or the telephoto lens is used as a macro, with a close shooting distance of about 30 cm; for mobile phone macro shooting, either the image is cropped or the distance is not close enough; therefore, the macro shooting ability is not outstanding. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a dual-view zoom macro optical system to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the utility model provides the following technical solutions:

[0006] A dual-view zoom macro optical system is sequentially provided with a first lens, a second lens and a third lens along the optical axis from the object plane to the aperture stop direction; the first lens is a negative lens, and its concave surface faces the image plane side; the second lens is a positive lens, and its convex surface faces the image plane side; the third lens is a positive meniscus lens, and its concave surface faces the image plane side; wherein, the aperture stop is the exit pupil of the optical system; the aperture stop is connected to the mobile phone lens or the human eye in an external connection manner;

[0007] When the aperture stop is connected to the mobile phone lens, the aperture stop is the entrance pupil of the mobile phone lens. By changing the exit pupil distance EPD of the optical system, the additional zoom macro as the mobile phone lens is changed, and macro shooting can be realized through the mobile phone lens; the mobile phone lens includes a lens assembly near the aperture stop position and an image plane far from the aperture stop position. The parallel light beam emitted from the aperture stop is refracted by the lens assembly and imaged on the image plane;

[0008] When the aperture stop is connected to the human eye, the aperture stop is the entrance pupil of the human eye; by changing the exit pupil distance EPD of the optical system, the function of a zoom magnifier is realized;

[0009] Among them, the exit pupil distance EPD of the optical system is the distance between the R6 surface on the third lens and the aperture stop;

[0010] The diameter of the aperture stop is less than 5 mm, and the angle of the parallel light rays emitted from the aperture stop is greater than 50°; the focusing distance of the optical system is 15 - 45 mm, and the focal length of the optical system is 39.6 - 62.7 mm, where the focusing distance is the distance between the object plane and the image plane.

[0011] As a further solution of the present utility model: the refractive indices of the first lens, the second lens, and the third lens are as follows:

[0012] 1.5 < Nd1 < 1.7; 1.49 < Nd2 < 1.65; 1.65 < Nd3 < 1.75;

[0013] In the above formula, Nd1 is the refractive index of the first lens; Nd2 is the refractive index of the second lens; Nd3 is the refractive index of the third lens.

[0014] As a further solution of the present utility model: the Abbe numbers of the first lens, the second lens, and the third lens are as follows:

[0015] 39 < Vd1 < 50; 53 < Vd2 < 65; 50 < Vd3 < 61;

[0016] In the above formula, Vd1 is the refractive index of the first lens; Vd2 is the refractive index of the second lens; Vd3 is the refractive index of the third lens.

[0017] As a further solution of the present utility model: the curvature radii of the first lens, the second lens, and the third lens are as follows:

[0018] -500 < R1 or R1 > 90.8; 11.4 < R2 < 27;

[0019] -445 < R3 < 113.4; -98.5 < R4 < -36;

[0020] 7.2 < R5 < 18.9; 11.2 < R6 < 41.8;

[0021] In the above formula, R1, R3, and R5 are the curvature radii of the first lens, the second lens, and the third lens near the object side, respectively; R2, R4, and R6 are the curvature radii of the first lens, the second lens, and the third lens near the image side, respectively.

[0022] As a further solution of the present utility model: the focal length ratio relationship between the first lens and the second lens and the third lens is as follows:

[0023] -1.5 < f1 / f2 - 3 < -1.1;

[0024] In the above formula, f1 is the focal length of the first lens, and f2-3 is the combined focal length of the second lens and the third lens.

[0025] As a further solution of the utility model: the distance ratio between the object plane and the first lens and between the first lens and the second lens is as follows:

[0026] 0.6<d1 / d2<9;

[0027] In the above formula, d1 is the distance from the object plane to the R1 surface on the first lens, and d2 is the distance between the R2 surface on the first lens and the R3 surface on the second lens; zooming is achieved by changing d1 and d2.

[0028] As a further solution of the utility model: the focusing distance of the optical system is 30-67.5 mm, and the focal length of the optical system is 57.2-89.5 mm.

[0029] Compared with the prior art, the utility model has the following beneficial effects:

[0030] The utility model adopts an external plug-in method to connect the optical system to the mobile phone lens, which can be used not only as the main camera of the mobile phone, but also as a telephoto camera of the mobile phone; and the optical system itself has a variable zoom function, which can realize macro shooting of different distances and different magnifications of the mobile phone; it also has the advantages of large light transmission, long exit pupil, low cost, low distortion and good imaging effect; it can also be connected to the human eye and used as a magnifying glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the optical structure of the utility model;

[0032] Figure 2 This is the layout diagram when the mobile phone lens is connected and the focus distance is 15-45 mm in Example 1;

[0033] Figure 3 This is the layout diagram when the focus distance is 15-45 mm in Embodiment 1.

[0034] Figure 4 This is the MTF curve diagram when the mobile phone lens is connected and the focus distance is 15mm in Example 1;

[0035] Figure 5 This is a diagram of field curvature and distortion when the mobile phone lens is connected and the focus distance is 15 mm in Example 1;

[0036] Figure 6 This is the MTF curve diagram when the mobile phone lens is connected and the focus distance is 45mm in Example 1;

[0037] Figure 7It is the field curvature and distortion diagram when the mobile phone lens is connected in Example 1 and the focusing distance is 45 mm;

[0038] Figure 8 It is the MTF curve graph when the human eye is connected in Example 1 and the focusing distance is 15 mm;

[0039] Figure 9 It is the field curvature and distortion diagram when the human eye is connected in Example 1 and the focusing distance is 15 mm;

[0040] Figure 10 It is the MTF curve graph when the human eye is connected in Example 1 and the focusing distance is 45 mm;

[0041] Figure 11 It is the field curvature and distortion diagram when the human eye is connected in Example 1 and the focusing distance is 45 mm;

[0042] Figure 12 It is the layout diagram when the mobile phone lens is connected in Example 2 and the focusing distance is 30 - 67.5 mm;

[0043] Figure 13 It is the layout diagram when the human eye is connected in Example 2 and the focusing distance is 30 - 67.5 mm;

[0044] Figure 14 It is the MTF curve graph when the mobile phone lens is connected in Example 2 and the focusing distance is 30 mm;

[0045] Figure 15 It is the field curvature and distortion diagram when the mobile phone lens is connected in Example 2 and the focusing distance is 30 mm;

[0046] Figure 16 It is the MTF curve graph when the mobile phone lens is connected in Example 2 and the focusing distance is 67.5 mm;

[0047] Figure 17 It is the field curvature and distortion diagram when the mobile phone lens is connected in Example 2 and the focusing distance is 67.5 mm;

[0048] Figure 18 It is the MTF curve graph when the human eye is connected in Example 2 and the focusing distance is 30 mm;

[0049] Figure 19 It is the field curvature and distortion diagram when the human eye is connected in Example 2 and the focusing distance is 30 mm;

[0050] Figure 20 It is the MTF curve graph when the human eye is connected in Example 2 and the focusing distance is 67.5 mm;

[0051] Figure 21 It is the field curvature and distortion diagram when the human eye is connected in Example 2 and the focusing distance is 67.5 mm.

[0052] In the figure: 1. Object surface; 2. First lens; 3. Second lens; 4. Third lens; 5. Aperture stop. Detailed implementation mode

[0053] Please refer to Figures 1 to 11 , in the embodiment of the present invention, a dual-view zoom macro optical system is provided, in which a first lens 2, a second lens 3, and a third lens 4 are sequentially arranged along the optical axis from the object surface 1 to the aperture stop 5; the first lens 2 is a negative lens, and its concave surface faces the image side; the second lens 3 is a positive lens, and its convex surface faces the image side; the third lens 4 is a positive meniscus lens, and its concave surface faces the image side; wherein, the aperture stop 5 is the exit pupil of the optical system; for the convenience of description, an ideal lens with a focal length of 4 mm is connected after the aperture stop 5 to replace the mobile phone lens or the human eye is connected in an external attachment manner.

[0054] Embodiment 1

[0055] When the aperture stop 5 is connected to the mobile phone lens,

[0056] the diameter of the aperture stop 5 = 3.8 mm, and the angle of the parallel light rays emitted from the aperture stop 5 = 85°, the focusing distance of the optical system is 15 - 45 mm, the focal length of the optical system is 39.6 - 62.7 mm, the exit pupil distance EPD = 6 mm, and the object field diameter is 71.7 - 111.6 mm.

[0057] When the aperture stop 5 is connected to the human eye,

[0058] the diameter of the aperture stop 5 = 3.8 mm, and the angle of the parallel light rays emitted from the aperture stop 5 = 53°, the focusing distance of the optical system is 15 - 45 mm, the focal length of the optical system is 39.6 - 62.7 mm, the exit pupil distance EPD = 10 mm, the object field diameter is 38.4 - 61.1 mm, and the magnification is 6.5X - 4X.

[0059] Among them, the surface type, radius of curvature, lens thickness, lens spacing, lens refractive index, and Abbe number of each lens are shown in Table 1.

[0060] Table 1

[0061] Surface number Radius of curvature Thickness Refractive index Abbe number 1 (object surface) Infinity 45～15 2 Infinity 2 1.57 42.8 3 19.69 6.8～15.3 4 -230.45 2.2 1.62 60.3 5 -74.85 0.1 6 14.3 3 5.35 1.73 54.7 7 31.80 6 or 10 8 (aperture stop) Infinity

[0062] Through experiments, it is obtained that: when the optical system is connected to the mobile phone lens or the human eye respectively, the zoom schematic diagrams at different focusing distances are as shown in Figure 2 and Figure 3 respectively; the corresponding MTF curve diagrams, field curvature and distortion diagrams are as shown in Figures 4 to 11 respectively.

[0063] Embodiment 2

[0064] When the aperture stop 5 is connected to the mobile phone lens,

[0065] The diameter of the aperture stop 5 = 3.8 mm, and the angle of the parallel light rays emitted from the aperture stop 5 = 85°. The focusing distance of the optical system is 30 - 67.5 mm, the focal length of the optical system is 57.2 - 89.5 mm, the exit pupil distance EPD = 6.4 mm, and the object field diameter is 106.4 - 160 mm.

[0066] When the aperture stop 5 is connected to the human eye,

[0067] The diameter of the aperture stop 5 = 3.8 mm, and the angle of the parallel light rays emitted from the aperture stop 5 = 53°. The focusing distance of the optical system is 30 - 67.5 mm, the focal length of the optical system is 57.2 - 89.5 mm, the exit pupil distance EPD = 9.4 mm, the object field diameter is 56.2 - 86.9 mm, and the magnification is 4.4X - 2.8X.

[0068] Among them, the surface type, radius of curvature, lens thickness, lens spacing, lens refractive index, and Abbe number of each lens are shown in Table 2.

[0069] Table 2

[0070] Surface number Radius of curvature Thickness Refractive index Abbe number 1 (object surface) Infinity 67.5～30 2 156.96 1.99 1.66 51.1 3 20.49 6.9～13.7 4 -338.36 2.52 1.59 61.3 5 -62.24 0.11 6 12.37 3.79 1.70 55.5 7 19.34 6.4 or 9.4 8 (aperture stop) Infinity

[0071] Through experiments, it is obtained that when the optical system is connected to the mobile phone lens or the human eye respectively, the zoom schematic diagrams at different focusing distances are as shown in Figure 12 and Figure 13 respectively; the corresponding MTF curve diagrams, field curvature and distortion diagrams are as shown in Figures 14 to 21 respectively.

[0072] The above is only the preferred specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution and the inventive concept of the present utility model, makes equivalent substitutions or changes, and should be covered within the protection scope of the present utility model.

Claims

1. A dual-view zoom macro optical system, characterized in that: A first lens (2), a second lens (3) and a third lens (4) are sequentially arranged along the optical axis from the object plane (1) to the aperture stop (5); the first lens (2) is a negative lens, and its concave surface faces the image plane side; the second lens (3) is a positive lens, and its convex surface faces the image plane side; the third lens (4) is a positive meniscus lens, and its concave surface faces the image plane side; wherein the aperture stop (5) is the exit pupil of the optical system; the aperture stop (5) is connected to the mobile phone lens or the human eye by means of an external plug-in; the diameter of the aperture stop (5) is less than 5 mm, and the angle of the parallel light emitted from the aperture stop (5) is greater than 50°; the focusing distance of the optical system is 15 to 45 mm, and the focal length of the optical system is 39.6 to 62.7 mm, wherein the focusing distance is the distance from the object plane (1) to the image plane.

2. A dual-view zoom macro optical system according to claim 1, characterized in that: The refractive indices of the first lens (2), the second lens (3) and the third lens (4) are as follows: 1.5<Nd1<1.7; 1.49<Nd2<1.65; 1.65<Nd3<1.75; In the above formula, Nd1 is the refractive index of the first lens (2); Nd2 is the refractive index of the second lens (3); and Nd3 is the refractive index of the third lens (4).

3. The dual-view zoom macro optical system according to claim 1, characterized in that: The Abbe numbers of the first lens (2), the second lens (3) and the third lens (4) are as follows: 39<Vd1<50; 53<Vd2<65; 50<Vd3<61; In the above formula, Vd1 is the refractive index of the first lens (2); Vd2 is the refractive index of the second lens (3); and Vd3 is the refractive index of the third lens (4).

4. The dual-view zoom macro optical system according to claim 1, characterized in that: The curvature radii of the first lens (2), the second lens (3) and the third lens (4) are as follows: -500<R1 or R1>90.8;11.4<R2<27; -445<R3<113.4; -98.5<R4<-36; 7.2<R5<18.9; 11.2<R6<41.8; In the above formula, R1, R3 and R5 are respectively the radii of curvature on the object side of the first lens (2), the second lens (3) and the third lens (4); R2, R4 and R6 are respectively the radii of curvature on the image side of the first lens (2), the second lens (3) and the third lens (4).

5. The dual-view zoom macro optical system according to claim 1, characterized in that: The focal length ratio relationship between the first lens (2) and the second lens (3) and the third lens (4) is as follows: -1.5<f1 / f2-3<-1.1; In the above formula, f1 is the focal length of the first lens (2), and f2-3 is the combined focal length of the second lens (3) and the third lens (4).

6. The dual-view zoom macro optical system according to claim 1, characterized in that: The distance ratios between the object plane (1) and the first lens (2) and between the first lens (2) and the second lens (3) are as follows: 0.6<d1 / d2<9; In the above formula, d1 is the distance from the object plane (1) to the R1 surface on the first lens (2), and d2 is the distance between the R2 surface on the first lens (2) and the R3 surface on the second lens (3); zooming is achieved by changing d1 and d2.

7. The dual-view zoom macro optical system according to claim 1, characterized in that: The focusing distance of the optical system is 30 to 67.5 mm, and the focal length of the optical system is 57.2 to 89.5 mm.

Images