Wide-angle lens of motion camera

Abstract

The utility model provides a wide-angle lens of a motion camera. A first lens (L1), a second lens (L2), a third lens (L3), a diaphragm (STO), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7) and protective glass (CG) are sequentially arranged from an object plane to an image plane. The seven lenses are all aspheric surfaces, and six glass lenses and one plastic lens are arranged, so that the high temperature resistance is good; the effective clear apertures of the first lens (L1) and the seventh lens (L7) are large, so that the field angle can be increased; a large aperture, namely a small F number, is provided; thickness and air space of all the lenses are small, thereby facilitating control of total length.

Description

TECHNICAL FIELD

[0001] The present application relates to a wide-angle lens for action cameras. BACKGROUND

[0002] With the popularity of outdoor sports, the demand for action cameras has increased. Users expect to record the action scene completely through a wide-angle lens with a large field of view to enhance the spatial sense of the picture. However, the traditional wide-angle lens for action cameras has the following problems: in order to achieve a large field of view, the optical structure of the lens becomes complex, and the total length increases, which not only makes the camera bulky and heavy, affecting the portability and flexible use, but also makes it more vulnerable. At the same time, the traditional lens has poor temperature resistance, and the lens is easy to deform and delaminate in high and low temperature environments, resulting in a decline in imaging quality. Therefore, it is necessary to develop a wide-angle lens for action cameras with short total length, large field of view and good temperature resistance. SUMMARY

[0003] In view of the demand of the existing market and the space for improvement, the present application provides a wide-angle lens for action cameras, which aims to solve the problems of large volume, long total length, insufficient field of view and poor temperature resistance of the current lens.

[0004] To achieve the above-mentioned purpose, the present application provides a wide-angle lens for action cameras, which is provided with a first lens (L1), a second lens (L2), a third lens (L3), a diaphragm (STO), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7) and a protective glass (CG) in order from the object plane to the image plane.

[0005] The first lens (L1) is a negative lens made of glass material, and the focal length satisfies -1.98

[0006] The second lens (L2) is a negative lens made of glass material, and the focal length satisfies -1.31

[0007] The third lens (L3) is a positive lens made of glass material, and the focal length satisfies 1.02

[0008] The fourth lens (L4) is a negative lens made of plastic material, and the focal length satisfies -1.56

[0009] The fifth lens (L5) is a positive lens, made of glass material, and has a focal length f5 / f satisfying 1.32<f5 / f<1.36; the object side surface (S10) is a convex surface and is aspherical, and the image side surface (S11) is a convex surface and is aspherical;

[0010] The sixth lens (L6) is a negative lens, made of glass material, and has a focal length f6 / f satisfying -18.3<f6 / f<-18.25; the object side surface (S12) is a concave surface and is aspherical, and the image side surface (S13) is a concave surface and is aspherical;

[0011] The seventh lens (L7) is a positive lens, made of glass material, and has a focal length f7 / f satisfying 2.53<f7 / f<2.57; the object side surface (S14) is a concave surface and is aspherical, and the image side surface (S15) is a convex surface and is aspherical.

[0012] The motion camera wide-angle lens satisfies the following relationship:

[0013] FNO<3;

[0014] 5.5<TTL / f<6.3;

[0015] Wherein, FNO is the F number of the motion camera wide-angle lens; f1 is the effective focal length of the first lens (L1), f2 is the effective focal length of the second lens (L2), f3 is the effective focal length of the third lens (L3), f4 is the effective focal length of the fourth lens (L4), f5 is the effective focal length of the fifth lens (L5), f6 is the effective focal length of the sixth lens (L6), f7 is the effective focal length of the seventh lens (L7), TTL is the on-axis distance from the object side surface (S1) of the first lens (L1) to the imaging surface (IMG); and f is the effective focal length of the motion camera wide-angle lens.

[0016] Preferably, the motion camera wide-angle lens satisfies the following relationship:

[0017] 4.8<Y1 / f<5;

[0018] 3.1<Y2 / f<3.3;

[0019] 160°<FOV<167°;

[0020] 7.94mm<H<8.26mm;

[0021] Wherein, Y1 is the effective clear aperture of the object side surface (S1) of the first lens (L1), Y2 is the effective clear aperture of the image side surface (S17) of the seventh lens (L7), f is the effective focal length of the motion camera wide-angle lens, FOV is the maximum field of view of the motion camera wide-angle lens, and H is the maximum real image height of the motion camera wide-angle lens.

[0022] Preferably, the wide-angle lens for the action camera is characterized by satisfying the following relationship:

[0023] 1.3 < (T11 + T21) / f < 1.32;

[0024] 0.31 < (T12 + T22) / f < 0.33;

[0025] 1.67 < (T13 + T23) / f < 1.69;

[0026] 0.12 < (T14 + T24) / f < 0.14;

[0027] 0.83 < (T15 + T25) / f < 0.85;

[0028] 0.99 < (T16 + T26) / f < 1.01;

[0029] 0.57 < (T17 + T27) / f < 0.59;

[0030] Wherein, T11 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S2) of the first lens (L1), T12 is the distance on the optical axis between the object-side surface (S3) and the image-side surface (S4) of the second lens (L2), T13 is the distance on the optical axis between the object-side surface (S5) and the image-side surface (S6) of the third lens (L3), T14 is the distance on the optical axis between the object-side surface (S8) and the image-side surface (S9) of the fourth lens (L4), T15 is the distance on the optical axis between the object-side surface (S10) and the image-side surface (S11) of the fifth lens (L5), T16 is the distance on the optical axis between the object-side surface (S12) and the image-side surface (S13) of the sixth lens (L6), and T17 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S13) of the seventh lens (L7). The distance between (S14) and the image side (S15) on the optical axis, T21 is the air gap between the first lens (L1) and the second lens (L2) on the optical axis, T22 is the air gap between the second lens (L2) and the third lens (L3) on the optical axis, T23 is the air gap between the third lens (L3) and the fourth lens (L4) on the optical axis, T24 is the air gap between the fourth lens (L4) and the fifth lens (L5) on the optical axis, T25 is the air gap between the fifth lens (L5) and the sixth lens (L6) on the optical axis, T26 is the air gap between the sixth lens (L6) and the seventh lens (L7) on the optical axis, and T27 is the air gap between the seventh lens (L7) and the protective glass (CG) on the optical axis.

[0031] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0032] 1. The aforementioned wide-angle lens for the action camera has 6 out of 7 lenses made of glass, which has a simple structure, is easy to grind and manufacture, and has good heat resistance. The only plastic lens is also made of OKP series, with a Tg temperature of 145℃, which makes the wide-angle lens of the action camera less prone to defocusing at high temperatures. The sixth lens (L6) has the largest focal length, which is beneficial for correcting higher-order aberrations. The second lens (L2), the third lens (L3), the fourth lens (L4), and the fifth lens (L5) are a combination of negative and positive lenses, which is beneficial for correcting chromatic aberration and field curvature, while also helping to reduce the overall length of the lens.

[0033] 2. The wide-angle lens of the action camera has a relatively large effective light-passing aperture of the first lens (L1) and the seventh lens (L7), which is beneficial to increase the field of view (FOV), which can reach a maximum of 167°.

[0034] 3. The wide-angle lens of the action camera has a small lens thickness and air gap, which helps to reduce aberrations. At the same time, the ratio of its total length to focal length is controlled between 5.5 and 6.3, so that the lens has a good depth of field and can meet the shooting needs from 1m to infinity. The ratio of the sum of lens thickness and air gap to focal length is within 1.7, which makes its total length small and helps to improve convenience and flexibility. [Attached Image Description]

[0035] Figure 1 This is a schematic diagram of the structure of the wide-angle lens of the action camera.

[0036] Figure 2 This is the chromatic aberration diagram (mm) of the wide-angle lens of this action camera.

[0037] Figure 3 This is a field curvature distortion (%) diagram of the wide-angle lens of the action camera.

[0038] Figure 4 This is the MTF diagram of the wide-angle lens of the action camera at a working distance of 1m.

[0039] Figure 5 This is the MTF diagram of the wide-angle lens of the action camera at an infinity working distance.

Detailed Implementation Methods

[0040] 1. A wide-angle lens for an action camera, characterized in that: from the object plane to the image plane, there are sequentially arranged a first lens (L1), a second lens (L2), a third lens (L3), an aperture stop (STO), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and a protective glass (CG);

[0041] The first lens (L1) is a negative lens made of glass, and its focal length satisfies -1.98 < f1 / f < -1.94; the object side (S1) is concave and aspherical, and the image side (S2) is concave and aspherical;

[0042] The second lens (L2) is a negative lens made of glass, and its focal length satisfies -1.31 < f2 / f < -1.27; the object side (S3) is concave and aspherical, and the image side (S4) is concave and aspherical;

[0043] The third lens (L3) is a positive lens made of glass, and its focal length satisfies 1.02 < f3 / f < 1.06; the object side (S5) is convex and aspherical, and the image side (S6) is convex and aspherical;

[0044] The fourth lens (L4) is a negative lens made of plastic, and its focal length satisfies -1.56 < f4 / f < -1.52; the object side (S8) is concave and aspherical, and the image side (S9) is concave and aspherical;

[0045] The fifth lens (L5) is a positive lens made of glass, and its focal length satisfies 1.32 < f5 / f < 1.36; the object side (S10) is convex and aspherical, and the image side (S11) is convex and aspherical;

[0046] The sixth lens (L6) is a negative lens made of glass, and its focal length satisfies -18.3 < f6 / f < -18.25; the object side (S12) is concave and aspherical, and the image side (S13) is concave and aspherical;

[0047] The seventh lens (L7) is a positive lens made of glass, and its focal length satisfies 2.53 < f7 / f < 2.57; the object side (S14) is concave and aspherical, and the image side (S15) is convex and aspherical;

[0048] This wide-angle lens of the action camera satisfies the following relationship:

[0049] FNO < 3;

[0050] 5.5 < TTL / f < 6.3;

[0051] Wherein, FNO is the F-number of the wide-angle lens of the action camera; f1 is the effective focal length of the first lens (L1), f2 is the effective focal length of the second lens (L2), f3 is the effective focal length of the third lens (L3), f4 is the effective focal length of the fourth lens (L4), f5 is the effective focal length of the fifth lens (L5), f6 is the effective focal length of the sixth lens (L6), f7 is the effective focal length of the seventh lens (L7), TTL is the on-axis distance from the object side surface (S1) of the first lens (L1) to the image plane (IMG); and f is the effective focal length of the wide-angle lens of the action camera.

[0052] The lens materials can withstand temperatures above 140°C, exhibiting good temperature resistance, which makes the wide-angle lens of this action camera less prone to defocusing at high temperatures;

[0053] 2. The wide-angle lens for an action camera as described above is characterized by satisfying the following relationship:

[0054] 4.8 <Y1 / f<5;

[0055] 3.1 <Y2 / f<3.3;

[0056] 160° <FOV<167°;

[0057] 7.94mm <H<8.26mm;

[0058] Where Y1 is the effective aperture of the object side (S1) of the first lens (L1), Y2 is the effective aperture of the image side (S17) of the seventh lens (L7), f is the effective focal length of the wide-angle lens of this action camera, FOV is the maximum field of view of the wide-angle lens of this action camera, and H is the maximum true image height of the wide-angle lens of this action camera.

[0059] The apertures of Y1 and Y2 ensure a sufficiently large field of view, while also ensuring a sufficiently large image height, allowing them to adapt to different chip specifications under different conditions.

[0060] 3. The wide-angle lens for an action camera as described above is characterized by satisfying the following relationship:

[0061] 1.3 < (T11 + T21) / f < 1.32;

[0062] 0.31 < (T12 + T22) / f < 0.33;

[0063] 1.67 < (T13 + T23) / f < 1.69;

[0064] 0.12 < (T14 + T24) / f < 0.14;

[0065] 0.83 < (T15 + T25) / f < 0.85;

[0066] 0.99 < (T16 + T26) / f < 1.01;

[0067] 0.57 < (T17 + T27) / f < 0.59;

[0068] Wherein, T11 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S2) of the first lens (L1), T12 is the distance on the optical axis between the object-side surface (S3) and the image-side surface (S4) of the second lens (L2), T13 is the distance on the optical axis between the object-side surface (S5) and the image-side surface (S6) of the third lens (L3), T14 is the distance on the optical axis between the object-side surface (S8) and the image-side surface (S9) of the fourth lens (L4), T15 is the distance on the optical axis between the object-side surface (S10) and the image-side surface (S11) of the fifth lens (L5), T16 is the distance on the optical axis between the object-side surface (S12) and the image-side surface (S13) of the sixth lens (L6), and T17 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S13) of the seventh lens (L7). The distance between (S14) and the image side (S15) on the optical axis, T21 is the air gap between the first lens (L1) and the second lens (L2) on the optical axis, T22 is the air gap between the second lens (L2) and the third lens (L3) on the optical axis, T23 is the air gap between the third lens (L3) and the fourth lens (L4) on the optical axis, T24 is the air gap between the fourth lens (L4) and the fifth lens (L5) on the optical axis, T25 is the air gap between the fifth lens (L5) and the sixth lens (L6) on the optical axis, T26 is the air gap between the sixth lens (L6) and the seventh lens (L7) on the optical axis, and T27 is the air gap between the seventh lens (L7) and the protective glass (CG) on the optical axis.

[0069] Sufficiently small lens thickness and air gaps ensure a small overall lens length.

[0070] Table 1 below is the lens data table for the embodiment.

[0071]

[0072] Table 2 below is a table of aspherical coefficients for the embodiments.

[0073] Surface K A4 A6 A8 A10 1 0 5.8043E-04 2.2063E-06 -3.6282E-07 9.2518E-09 2 0 -3.5089E-04 9.3920E-05 -5.9086E-06 5.9864E-07 3 0 4.2258E-04 7.4854E-05 -1.9849E-05 2.5400E-06 4 0 -8.3495E-04 9.1464E-05 5.2693E-05 -2.0321E-05 5 0 -2.2585E-03 1.4234E-05 3.7145E-05 -1.2067E-05 6 0 2.8818E-03 -5.2566E-04 8.3675E-05 -1.3710E-05 8 0 -7.2813E-03 5.7677E-04 -7.0186E-04 2.4534E-04 9 0 -1.5238E-02 7.4928E-03 -7.0297E-03 5.3284E-03 10 0 -5.9742E-03 5.9285E-03 -5.0263E-03 3.5539E-03 11 0 -1.5304E-03 3.8297E-04 5.6670E-05 -7.2766E-05 12 0 -1.2541E-02 2.0758E-03 -3.9423E-04 8.0137E-05 13 0 -1.3112E-02 2.1329E-03 -3.2718E-04 5.0603E-05 14 0 -1.0859E-03 -2.7311E-04 2.8714E-05 -1.3407E-06 15 0 1.1303E-02 -1.9249E-03 1.5401E-04 -7.3055E-06 Surface A12 A14 A16 A18 A20 1 -1.3017E-10 1.1381E-12 -6.1568E-15 1.8912E-17 -2.5220E-20 2 -4.7419E-08 2.7955E-09 -1.2180E-10 3.2578E-12 -3.8376E-14 3 -1.8653E-07 8.4765E-09 -2.3790E-10 3.8021E-12 -2.6544E-14 4 4.3181E-06 -5.3784E-07 3.9946E-08 -1.6500E-09 2.9107E-11 5 2.2239E-06 -2.5756E-07 1.8188E-08 -7.1942E-10 1.2101E-11 6 1.3764E-06 -5.6100E-08 0.0000E+00 0.0000E+00 0.0000E+00 8 -3.9651E-05 2.5993E-06 0.0000E+00 0.0000E+00 0.0000E+00 9 -2.9291E-03 1.0897E-03 -2.5861E-04 3.5364E-05 -2.1210E-06 10 -1.7727E-03 5.7926E-04 -1.1909E-04 1.4182E-05 -7.5573E-07 11 4.6887E-06 2.3613E-05 -1.2475E-05 2.5509E-06 -1.9077E-07 12 -1.3078E-05 1.4282E-06 -9.9316E-08 4.0338E-09 -7.4491E-11 13 -6.1318E-06 4.8796E-07 -2.3722E-08 6.3852E-10 -7.2852E-12 14 3.6268E-08 -5.9568E-10 5.7854E-12 -2.9696E-14 5.7093E-17 15 2.2072E-07 -4.3135E-09 5.2964E-11 -3.7142E-13 1.1323E-15

[0074] The above content is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications made within the design and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wide-angle lens for an action camera, characterized in that: A first lens (L1), a second lens (L2), a third lens (L3), a stop (STO), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and a protective glass (CG) are sequentially provided from the object surface to the image surface; The first lens (L1) is a negative lens, made of glass, and its focal length satisfies -1.98 < f1 / f < -1.94; the object side surface (S1) is a concave surface and an aspherical surface, and the image side surface (S2) is a concave surface and an aspherical surface; The second lens (L2) is a negative lens, made of glass, and its focal length satisfies -1.31 < f2 / f < -1.27; the object side surface (S3) is a concave surface and an aspherical surface, and the image side surface (S4) is a concave surface and an aspherical surface; The third lens (L3) is a positive lens, made of glass, and its focal length satisfies 1.02 < f3 / f < 1.06; the object side surface (S5) is a convex surface and an aspherical surface, and the image side surface (S6) is a convex surface and an aspherical surface; The fourth lens (L4) is a negative lens, made of plastic, and its focal length satisfies -1.56 < f4 / f < -1.52; the object side surface (S8) is a concave surface and an aspherical surface, and the image side surface (S9) is a concave surface and an aspherical surface; The fifth lens (L5) is a positive lens, made of glass, and its focal length satisfies 1.32 < f5 / f < 1.36; the object side surface (S10) is a convex surface and an aspherical surface, and the image side surface (S11) is a convex surface and an aspherical surface; The sixth lens (L6) is a negative lens, made of glass, and its focal length satisfies -18.3 < f6 / f < -18.25; the object side surface (S12) is a concave surface and an aspherical surface, and the image side surface (S13) is a concave surface and an aspherical surface; The seventh lens (L7) is a positive lens, made of glass, and its focal length satisfies 2.53 < f7 / f < 2.57; the object side surface (S14) is a concave surface and an aspherical surface, and the image side surface (S15) is a convex surface and an aspherical surface; This wide-angle lens of the action camera satisfies the following relationships: ​ ​ ​ 2. The wide-angle lens for an action camera as described in claim 1, characterized in that, ​ ​ ​ ​ ​ Where Y1 is the effective aperture of the object side (S1) of the first lens (L1), Y2 is the effective aperture of the image side (S17) of the seventh lens (L7), f is the effective focal length of the wide-angle lens of this action camera, FOV is the maximum field of view of the wide-angle lens of this action camera, and H is the maximum true image height of the wide-angle lens of this action camera.

3. The wide-angle lens for an action camera as described in claim 1, characterized in that, The following relationship must be satisfied: 1.3 < (T11 + T21) / f < 1.32; 0.31 < (T12 + T22) / f < 0.33; 1.67 < (T13 + T23) / f < 1.69; 0.12 < (T14 + T24) / f < 0.14; 0.83 < (T15 + T25) / f < 0.85; 0.99 < (T16 + T26) / f < 1.01; 0.57 < (T17 + T27) / f < 0.59; Wherein, T11 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S2) of the first lens (L1), T12 is the distance on the optical axis between the object-side surface (S3) and the image-side surface (S4) of the second lens (L2), T13 is the distance on the optical axis between the object-side surface (S5) and the image-side surface (S6) of the third lens (L3), T14 is the distance on the optical axis between the object-side surface (S8) and the image-side surface (S9) of the fourth lens (L4), T15 is the distance on the optical axis between the object-side surface (S10) and the image-side surface (S11) of the fifth lens (L5), T16 is the distance on the optical axis between the object-side surface (S12) and the image-side surface (S13) of the sixth lens (L6), and T17 is the distance on the optical axis between the object-side surface (S1) and the image-side surface (S13) of the seventh lens (L7). The distance between (S14) and the image side (S15) on the optical axis, T21 is the air gap between the first lens (L1) and the second lens (L2) on the optical axis, T22 is the air gap between the second lens (L2) and the third lens (L3) on the optical axis, T23 is the air gap between the third lens (L3) and the fourth lens (L4) on the optical axis, T24 is the air gap between the fourth lens (L4) and the fifth lens (L5) on the optical axis, T25 is the air gap between the fifth lens (L5) and the sixth lens (L6) on the optical axis, T26 is the air gap between the sixth lens (L6) and the seventh lens (L7) on the optical axis, and T27 is the air gap between the seventh lens (L7) and the protective glass (CG) on the optical axis.

Images