CN210639334U

CN210639334U - Ultrathin lens of single lens reflex

Info

Publication number: CN210639334U
Application number: CN201921648868.7U
Authority: CN
Inventors: 吴强华; 胡长涛; 张福美
Original assignee: Jiangxi Telaisi Optical Co ltd
Current assignee: Jiangxi Telaisi Optical Co ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2020-05-29
Anticipated expiration: 2029-09-30

Abstract

The utility model relates to an ultrathin lens of a single lens reflex, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are arranged in sequence from an object side to an image side; the first lens is a biconcave lens with a negative focal length; the second lens is a meniscus lens with positive focal length, and the convex surface faces the object side; the third lens is a biconvex lens with positive focal length; the fourth lens is a biconvex lens with positive focal length; the fifth lens is a biconcave lens with a negative focal length; the sixth lens is a meniscus lens with positive focal length, and one surface facing the object side is a concave surface; the seventh lens is a biconcave lens with a negative focal length; the eighth lens is a biconvex lens with a positive focal length; the ninth lens is a biconvex lens with positive focal length; the tenth lens is a biconcave lens with a negative focal length. The utility model discloses a camera lens has ultrahigh resolution, big light ring, ultra-thin advantage.

Description

Ultrathin lens of single lens reflex

Technical Field

The utility model relates to an ultra-thin camera lens of single opposition machine belongs to optical imaging technology field.

Background

In digital camera equipment, a certain gap exists in the production design of domestic lenses, and the number of photographing enthusiasts is increased along with the improvement of living standard of people, so that the demand of the aspect is increased. In the design of the existing full-width lens, such as a 35mm lens produced by manufacturers such as Nikon, Canon and horse, the maximum aperture is only F1.4, the cost performance is low, the design of domestic manufacturers generally mainly adopts a full-glass spherical surface, the aberration can not be well corrected, the using effect can be achieved only by widening the length of the lens and increasing the number of lenses, and the lens has the defects of large volume and inconvenient carrying due to overweight. Just disclose a single opposition machine super aperture wide-angle lens as patent 201610346001, its technical scheme exists the shortcoming has: the length of the lens is too long to reach 135 mm; the diameter of the lens is larger, and is generally 40-50 mm; the number of the lenses is large. Therefore, it is necessary to design an ultra-thin full-frame lens with large light flux.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an ultra-thin camera lens of single lens reflex, concrete scheme is:

a single lens reflex ultrathin lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are arranged in sequence from an object side to an image side; the first lens is a biconcave lens with a negative focal length; the second lens is a meniscus lens with positive focal length, and the convex surface faces the object side; the third lens is a biconvex lens with positive focal length; the fourth lens is a biconvex lens with positive focal length; the fifth lens is a biconcave lens with a negative focal length; the sixth lens is a meniscus lens with positive focal length, and one surface facing the object side is a concave surface; the seventh lens is a biconcave lens with a negative focal length; the eighth lens is a biconvex lens with a positive focal length; the ninth lens is a biconvex lens with positive focal length; the tenth lens is a biconcave lens with a negative focal length; the third lens and the sixth lens are glass aspheric lenses, and the other lenses are glass spherical lenses; the focal length of the third lens is f3, the focal length of the sixth lens is f6, the overall focal length of the lens is f, and the relation is satisfied:

1.08<(f3/f)<1.5(1)

4.5<(f6/f)<6.5(2)。

preferably, the refractive index of the material of the third lens is ND3, the refractive index of the material of the sixth lens is ND6, and the relationship is satisfied: ND3 ═ ND6> 1.85.

Preferably, the first lens and the second lens are a set of double-cemented lens, the fourth lens and the fifth lens are a set of double-cemented lens, the seventh lens and the eighth lens are a set of double-cemented lens, and the ninth lens and the tenth lens are a set of double-cemented lens.

Preferably, in the double cemented lens, the refractive index of the lens with the positive focal length is larger than 1.88, and the abbe number of the lens with the negative focal length is smaller than 35.

Preferably, a diaphragm device is arranged between the fifth lens and the sixth lens.

The utility model discloses a reasonable use glass aspheric surface and two cemented lens group, inject structure, focal power, the arrangement order etc. of every lens, the effectual overall length that has reduced the camera lens to the effect of making a video recording has been improved. This patent has ultrahigh resolution, big light ring, ultra-thin characteristics, for prior art, the utility model has the following beneficial points:

1. the length is ultra-thin and is controlled below 70 mm.

2. The diameter of the lens is small and is controlled below 30 mm.

3. The number of lenses is small.

Drawings

Fig. 1 is a schematic view of a lens according to an embodiment of the present invention;

fig. 2 is an analytic view of an embodiment of the present invention;

fig. 3 is a distortion diagram of the embodiment of the present invention;

fig. 4 is a relative illuminance diagram according to an embodiment of the present invention.

Detailed Description

As shown in fig. 1, an embodiment of the present invention provides an optical lens, sequentially from an object side to an image side along an optical axis direction, comprising: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, and a tenth lens 10. The first lens 1 is a biconcave lens with a negative focal length, the second lens 2 is a meniscus lens with a positive focal length, the convex surface faces the object, the third lens 3 is a biconvex lens with a positive focal length, the fourth lens 4 is a biconvex lens with a positive focal length, the fifth lens 5 is a biconcave lens with a negative focal length, the sixth lens 6 is a meniscus lens with a positive focal length, the side of the meniscus lens facing the object side is a concave surface, the seventh lens 7 is a biconcave lens with a negative focal length, the eighth lens 8 is a biconvex lens with a positive focal length, the ninth lens 9 is a biconvex lens with a positive focal length, and the tenth lens 10 is a biconcave lens with a negative focal length. The third lens and the sixth lens are glass aspheric lenses, and the other lenses are glass spherical lenses. The third lens and the sixth lens are glass aspheric lenses, and the other lenses are glass spherical lenses. Through reasonable use glass aspheric surface and two cemented lens group, the effectual overall length that reduces the camera lens to the effect of making a video recording has been improved. The lens has the characteristics of ultrahigh resolution, large aperture and ultra-thin, and overcomes the defects in the prior art.

Adopt the utility model provides an optical lens system's structural shape, the abbe coefficient isoparametric of optical glass material and imaging condition match the preferred for the spherical aberration of lens system, coma, astigmatism, field curvature, multiplying power colour difference, position colour difference obtain fine correction, satisfy the operation requirement and the overall dimension of single lens reflex camera and be convenient for carry.

In particular, the embodiment of the present invention provides an optical lens assembly, as shown in fig. 1, the first lens and the second lens are a set of double-cemented lens a, the fourth lens and the fifth lens are a set of double-cemented lens B, the seventh lens and the eighth lens are a set of double-cemented lens C, the ninth lens and the tenth lens are a set of double-cemented lens D, and a diaphragm device ST is disposed between the fifth lens and the sixth lens. Because the lens with positive focal power has negative chromatic aberration, and the lens with negative focal power has positive chromatic aberration, the chromatic aberration is compensated and eliminated by forming the cemented lens group through the seamless cementing of the lens with positive focal power and the lens with negative focal power. The embodiment of the utility model provides a tight shot contains four group's cemented lens, contains a focus respectively and is positive lens and a focus for the lens of burden, realizes that the colour difference compensates each other, eliminates the colour difference, optimizes the definition of formation of image, improves optical system's image quality, improves resolution ratio.

Further, in the above optical lens system provided by the embodiment of the present invention, as shown in fig. 1, the refractive index of the positive lens, ND2, ND4, ND8, and ND9 are all greater than 1.88, the larger the refractive index of the lens is, the larger the light deflection angle is, the shorter the optical path is, and the total length of the system can be effectively reduced by using a high refractive index material for the positive lens.

Further, in the above optical lens system provided in the embodiment of the present invention, the focal length of the third lens is f3, the focal length of the sixth lens is f6, the overall focal length of the lens is f, and the following relation is satisfied: 1.08< (f3/f) <1.5 (1); 4.5< (f6/f) <6.5 (2).

When the value of | f3/f | exceeds the upper limit of 1.5, f3 is relatively large, namely, the focal power is relatively small, so that the optical back focus is insufficient, and the structural space is difficult to arrange parts such as an automatic switching device of the red filter; when the value of | f3/f | is below the lower limit of 6.75, f3 becomes relatively small, i.e., the power becomes relatively large, which causes an increase in high-order aberration. Therefore, the optical lens in the embodiment of the present invention can achieve better imaging quality and a reasonable structural space form when the condition 1.08< (f3/f) <1.5 is satisfied.

Further, when the value of | f6/f | exceeds the upper limit of 6.5, f6 becomes relatively large, i.e., the focal power becomes relatively small, so that the optical back focus is insufficient, and the structural space is difficult to arrange components such as an automatic switching device of the red filter; when the value of | f6/f | is lower than the lower limit of 4.5, f6 becomes relatively small, i.e., the power becomes relatively large, which causes an increase in high-order aberration, so that a large number of lenses are required, making it difficult to realize an optical system with good imaging performance by a small number of lens structures. Therefore, the optical lens in the embodiment of the present invention can achieve better imaging quality when the condition 4.5< (f6/f) <6.5 is satisfied.

The following will be mentioned, in the embodiments of the optical lens of the present invention, the total focal length f is 35.4mm, the FNO is 1.2, the field angle FOV is 64 °, the lens distortion is-2%, and the total length 65mm of the ultra-thin digital single lens reflex super-large aperture full-width lens, and the parameters of the lens set are listed in table 1 in sequence:

TABLE 1

In table 1, surface is a surface number, Thickness is a Thickness parameter, glass name is a glass material, Index is a refractive Index, ABB is an abbe constant, Radius is a curvature Radius, and EFL-E is focal lengths f1 to f10 of the first lens to the tenth lens in this order.

In table 1,

mirror numbers

1, 2, and 3 sequentially represent three mirror surfaces of the cemented lens group a in the light incidence direction, wherein 2 represents the cemented surfaces of the lens 1 and the lens 2,

mirror numbers

4 and 5 represent two mirror surfaces of the lens 3 in the light incidence direction, mirror number 4 represents a mirror surface of the lens 3 facing the object, mirror number 5 represents a mirror surface of the lens 3 facing the image,

mirror numbers

6, 7, and 8 sequentially represent three mirror surfaces of the cemented lens group B in the light incidence direction, wherein 7 represents the cemented surfaces of the lens 4 and the lens 5,

mirror numbers

9, 10 represent two mirror surfaces of the lens 6 in the light incidence direction, mirror number 9 represents a mirror surface of the lens 6 toward the object side, mirror number 10 represents a mirror surface of the lens 6 toward the image side, mirror numbers 11, 12, 13 represent three mirror surfaces of the cemented lens group C in the light incidence direction in order, wherein 12 represents a cemented surface of the lens 7 and the lens 8, mirror numbers 14, 15, 16 represent three mirror surfaces of the cemented lens group D in the light incidence direction in order, wherein 15 represents a cemented surface of the lens 9 and the lens 10,

in the embodiment of the present invention, f3/f is 45.928366/35.4 is 1.297, and 1.08< (f3/f) <1.5 is satisfied. In the embodiment of the present invention, f6/f is 196.0935/35.4 is 5.54, and satisfies 4.5< (f6/f) < 6.5.

In the embodiment of the present invention, the third lens and the sixth lens are glass aspheric lenses, the material is M-TAFD307, the material refractive index ND3 is ND6 is 1.882023, and high refractive materials are all adopted, which satisfy the following relation: ND3 ═ ND6> 1.85.

In the embodiment of the present invention, ND2 ═ 1.953747, ND4 ═ 1.883, ND8 ═ 1.883, ND9 ═ 1.883, all are greater than 1.88, VD1 ═ 33.842283, VD5 ═ 31.160527, VD7 ═ 28.315013, VD10 ═ 33.842283, all are less than 35, and all satisfy the requirements.

In this embodiment, the third lens element and the sixth lens element are glass aspheric lens elements, and the aspheric values thereof are listed in table 2 in sequence:

TABLE 2

SURFACE:4	SURFACE:5
		K＝-4.427041343	K＝171119.702277300
E4＝-0.000004440658146468	E4＝-0.000009357608530060
		E6＝-0.000000052134992337	E6＝-0.000000046762800032
E8＝-0.000000000023607920	E8＝-0.000000000078832522
		E10＝-0.000000000000641100	E10＝-0.000000000000174200
R1＝40.238326956	R2＝5620.021630922

SURFACE:9	SURFACE:10
		K＝25.615371731	K＝12.490803098
E4＝-0.000033915993811870	E4＝-0.000002343772665113
		E6＝-0.000000235083498050	E6＝-0.000000159653338750
E8＝0.000000000129358261	E8＝0.000000000491574246
		E10＝0.000000000001967100	E10＝0.000000000001638900
R1＝-75.714027656	R2＝-53.301652968

In the embodiment of the present invention, it can be calculated from table 1 that the field angle 2w of the optical lens is 64 degrees, and the relative aperture is 1.2. The embodiment of the utility model provides an in, the camera lens overall length is 65mm, and the structure is compacter. Fig. 2 is a graph of Modulation Transfer Function (MTF) of the visible band, representing the integrated resolving power of the optical system, where the horizontal axis represents spatial frequency in units: the number of turns is per millimeter (cycles/mm), the pixel of a single lens reflex chip is large, the evaluation is carried out for 40lp/mm, the longitudinal axis represents the numerical value of a Modulation Transfer Function (MTF), the numerical value of the MTF is used for evaluating the imaging quality of a lens, the value range is 0-1, particularly, the optical transfer function is used for evaluating the imaging quality of an optical system in a more accurate, visual and common mode, the higher and smoother curve is, the better the imaging quality of the system is, and the stronger the restoring capability to a real image is; as can be seen from FIG. 2, when the spatial frequency of the visible light band is 40lp/mm, the MTF of the main field is greater than 0.2, and the digital single lens reflex super-large aperture full-frame lens has the advantages of being ultrathin, having a super-large aperture, correcting various aberrations, compact in structure, good in imaging effect and high in cost performance.

Fig. 2 is a distortion graph corresponding to the visible light part of the lens system, wherein the distortion rate is smaller as the curve is closer to the y-axis. As shown in FIG. 3, in which the optical distortion ratio is controlled within the range of-2% to 0%, no significant distortion is observed in the image. As shown in fig. 4, the single-lens reflex camera has a large pixel, good light sensitivity, and a relative illumination greater than 20%, and meets the use requirements.

Claims

1. The utility model provides an ultra-thin camera lens of single opposition machine which characterized in that: the zoom lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are arranged in sequence from the object side to the image side; the first lens is a biconcave lens with a negative focal length; the second lens is a meniscus lens with positive focal length, and the convex surface faces the object side; the third lens is a biconvex lens with positive focal length; the fourth lens is a biconvex lens with positive focal length; the fifth lens is a biconcave lens with a negative focal length; the sixth lens is a meniscus lens with positive focal length, and one surface facing the object side is a concave surface; the seventh lens is a biconcave lens with a negative focal length; the eighth lens is a biconvex lens with a positive focal length; the ninth lens is a biconvex lens with positive focal length; the tenth lens is a biconcave lens with a negative focal length; the third lens and the sixth lens are glass aspheric lenses, and the other lenses are glass spherical lenses; the focal length of the third lens is f3, the focal length of the sixth lens is f6, the overall focal length of the lens is f, and the relation is satisfied:

1.08<(f3/f)<1.5(1)

4.5<(f6/f)<6.5(2)。

2. the lens barrel according to claim 1, characterized in that: the refractive index of the material of the third lens is ND3, the refractive index of the material of the sixth lens is ND6, and the relation is satisfied: ND3 ═ ND6> 1.85.

3. The lens barrel according to claim 1, characterized in that: the first lens and the second lens are a group of double-cemented lenses, the fourth lens and the fifth lens are a group of double-cemented lenses, the seventh lens and the eighth lens are a group of double-cemented lenses, and the ninth lens and the tenth lens are a group of double-cemented lenses.

4. The lens barrel according to claim 3, characterized in that: in the double-cemented lens, the refractive index of the lens with the positive focal length is larger than 1.88, and the dispersion coefficient of the lens with the negative focal length is smaller than 35.

5. The lens barrel according to claim 1, characterized in that: and a diaphragm device is arranged between the fifth lens and the sixth lens.