Optical camera lens

The present disclosure relates to the field of optical lens and, particularly, relates to an optical camera lens adapted for portable terminal devices such as smart cellphone, digital camera etc. and for camera devices such as monitor, PC lens etc.

In recent years, as the booming development of the smart cellphone, the need on miniaturized camera lens is increasing gradually. However, the photosensitive component of a conventional camera lens is either a charge coupled device (Charge Coupled Device, CCD) or a complementary metallic-oxide semiconductor sensor (Complementary Metal-Oxide Semiconductor Sensor, CMOS Sensor). With the development of semiconductor processing technique, pixel size of the photosensitive component is reduced. In addition, the electronic product at present is developed to have better functions and a lighter and thinner configuration. Therefore, a miniaturized camera lens with better imaging quality has already become the mainstream in the current market.

In order to obtain better imaging quality, a traditional lens carried in a cellphone camera usually adopts a three-lens or four-lens structure. As the development of techniques and increasing of user's diversified needs, in the situation of the pixel area of the photosensitive component being reduced, and the requirements of the system on imaging quality being increased constantly, a five-lens structure appears in the lens design gradually. However, a five-lens camera lens satisfying requirements on long focal length generally has a relative large total track length (Total Track Length, TTL), and a relative small aperture, which cannot satisfy the design needs on low TTL and large aperture, thus is not suitable for micro camera devices, and the ability of background weakening thereof is poor and the object cannot be highlighted.

Many aspects of the exemplary embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a structural schematic diagram of an optical camera lens according to an exemplary embodiment of the present disclosure;

FIG. 2 is a schematic diagram of axial chromatic aberration of an optical camera lens shown in FIG. 1 ;

FIG. 3 is a schematic diagram of ratio chromatic aberration of an optical camera lens shown in FIG. 1 ;

FIG. 4 is a schematic diagram of astigmatism field curvature and distortion of an optical camera lens shown in FIG. 1 .

In order to make objectives, technical solutions and advantages of the present disclosure more clearly, embodiments of the present disclosure will be illustrated in detail with reference to the accompanying drawings. Those skilled in the art should understand, in each implementing manner of the present disclosure, in order to make the reader understand the present disclosure, a plurality of technical details have been proposed. However, the technical solutions protected by the present disclosure shall also be implemented without these technical details and the various modifications and variations presented in the embodiments.

Referring to the figures, the present disclosure provides an optical camera lens. FIG. 1 shows an optical camera lens 10 according to an exemplary embodiment of the present disclosure, the optical camera lens 10 includes five lenses. Specifically, the optical camera lens 10 , from the object side to the image side, successively includes: an aperture St, a first lens L 1 , a second lens L 2 , a third lens L 3 , a fourth lens L 4 and a fifth lens L 5 . An optical component such as an optical filter GF can be arranged between the fifth lens L 5 and an imaging surface Si.

The first lens L 1 has positive refraction power, an object-side surface thereof bulges outward to be a convex surface, an aperture St is arranged between the object and the first lens L 1 . The second lens L 2 has negative refraction power, in the present embodiment, an image-side surface of the second lens L 2 is a concave surface. The third lens L 3 has positive refraction power, in the present embodiment, an object-side surface of the third lens L 3 is a convex surface. The fourth lens L 4 has negative refraction power, in the present embodiment, an object-side surface of the fourth lens L 4 is a concave surface. The fifth lens L 5 has negative refraction power, which can effectively reduce field curvature of the system. In the present embodiment, an object-side surface of the fifth lens L 5 is a concave surface.

Herein, a focal length of the integral optical camera lens 10 is defined as f, a focal length of the first lens L 1 is defined as f 1 , a focal length of the second lens L 2 is defined as f 2 , a focal length of the third lens L 3 is defined as f 3 , a focal length of the fourth lens L 4 is defined as f 4 and a focal length of the fifth lens L 5 is defined as f 5 . The f, f 1 , f 2 , f 3 , f 4 and f 5 satisfy the following relational expressions: 0.4<f 1 /f<0.55, −0.8<f 2 /f<−0.7, 2.0<f 3 /f<2.3, −1.9<f 4 /f<−1.7, −1.6<f 5 /f<−1.2, 0.3<f 2 /f 4 <0.45.

When the focal lengths of the optical camera lens 10 and each lens meet the above relational expressions, the refraction power configuration of each lens can be controlled/adjusted, which is adaptive to effectively control the total track length of the system while correcting image difference, reducing field curvature so as to guarantee imaging quality and, at the same time, meet the design requirements on large aperture, thereby achieving good sensitivity performance, and can effectively weaken the background and highlight the focusing object.

Specifically, in an embodiment of the present disclosure, the focal length f 1 of the first lens, the focal length f 2 of the second lens, the focal length f 3 of the third lens, the focal length f 4 of the fourth lens and the focal length f 5 of the fifth lens can be designed so as to satisfy the following relational expressions: 2.4<f 1 <2.7, −4.1<f 2 <−3.6, 11<f 3 <12, −10<f 4 <−9, −8<f 5 <−7, unit: millimeter (mm). Such a design can further shorten the total track length TLL of the integral optical camera lens 10 , so as to maintain the characteristics of miniaturization.

Optionally, the total track length TTL of the optical camera lens 10 according to an embodiment of the present disclosure is equal to or less than 5.0 mm. Such a design is more advantageous to achieve the miniaturized design of the optical camera lens 10 . Optionally, in an embodiment of the present disclosure, a value F of the aperture of the optical camera lens is equal to or less than 2.4, the optical camera lens 10 is an optical system with a relative large aperture, which can improve imaging performance in a low irradiance environment.

In the optical camera lens 10 of the present disclosure, each lens can be made of glass or plastic, if the lens is made of glass, which can increase the freedom of the refraction power configuration of the optical system of the present disclosure, if the lens is made of plastic, which can effectively reduce production cost.

Optionally, in an embodiment of the present disclosure, the focal length f of the integral optical camera lens 10 satisfies relational expression: f>5.3 mm, the optical camera lens 10 is a long focus optical system, which can effectively weaken the background and highlight the focusing object.

Besides, in an embodiment of the present disclosure, a field of view (Field of View, FOV) of the optical camera lens 10 satisfies relational expression: 47°<FOV<52°.

In an embodiment of the present disclosure, all lenses are plastic lenses. Further, in a preferred embodiment of the present disclosure, a refractive index n 1 of the first lens, a refractive index n 2 of the second lens, a refractive index n 3 of the third lens, a refractive index n 4 of the fourth lens and a refractive index n 5 of the fifth lens satisfy the following conditional expressions: 1.52<n 1 <1.56, 1.62<n 2 <1.68, 1.62<n 3 <1.68, 1.52<n 4 <1.56, 1.52<n 5 <1.56. Such a design is advantageous for an appropriate matching of the lenses with the material, so that the optical camera lens 10 can obtain better imaging quality.

It should be noted that, in an embodiment of the present disclosure, an abbe number v 1 of the first lens, an abbe number v 2 of the second lens, an abbe number v 3 of the third lens, an abbe number v 4 of the fourth lens and an abbe number v 5 of the fifth lens can be designed to satisfy the following relational expressions: 50<v 1 <60, 20<v 2 <23, 20<v 3 <23, 50<v 4 <60, 50<v 5 <60. Such a design can suppress the phenomenon of optical chromatic aberration during imaging by the optical camera lens 10 .

It should be understood that, the design solution of the refractive index of each lens and the design solution of the abbe number of each lens can be combined with each other so as to be applied to the design of the optical camera lens 10 . Thus, the second lens L 2 and the third lens L 3 adopt an optical material with high a refractive index and a low abbe number, which can effectively reduce chromatic aberration of the system, and significantly improve imaging quality of the optical camera lens 10 .

Besides, the surface of the lens can be an aspheric surface, the aspheric surface can be easily made into shapes other than spherical surface, so as to obtain more controlling varieties, which are used to eliminate aberration so as to reduce the number of the lens used, thereby can reduce the total track length of the optical camera lens of the present disclosure effectively. In an embodiment of the present disclosure, the object-side surface and the image-side surface of each lens are all aspheric surfaces.

Optionally, an inflection point and/or a stationary point can be provided on the object-side surface and/or the image-side surface of the lens, so as to satisfy the imaging needs on high quality, the specific implementing solution is as follows.

The design data of the optical camera lens 10 according to Embodiment 1 of the present disclosure is shown as follows.

Table 1 and Table 2 show data of the lens in the optical camera lens 10 according to Embodiment 1 of the present disclosure.

in which, meaning of each symbol is as follows.

f: focal length of the optical camera lens 10 ;

f 1 : focal length of the first lens L 1 ;

f 2 : focal length of the second lens L 2 ;

f 3 : focal length of the third lens L 3 ;

f 4 : focal length of the fourth lens L 4 ;

f 5 : focal length of the fifth lens L 5 .

R 1 , R 2 are the object-side surface and the image-side surface of the first lens L 1 , respectively; R 3 , R 4 are the object-side surface and the image-side surface of the second lens L 2 , respectively; R 5 , R 6 are the object-side surface and the image-side surface of the third lens L 3 , respectively; R 7 , R 8 are the object-side surface and the image-side surface of the fourth lens L 4 , respectively; R 9 , R 10 are the object-side surface and the image-side surface of the fifth lens L 5 , respectively; R 11 , R 12 are the object-side surface and the image-side surface of the optical filter GF, respectively. Meanings of other symbols are as follows.

d 0 : axial distance from the aperture St to the object-side surface of the first lens L 1 ;

d 1 : axial thickness of the first lens L 1 ;

d 2 : axial distance from the image-side surface of the first lens L 1 to the object-side surface of the second lens L 2 ;

d 3 : axial thickness of the second lens L 2 ;

d 4 : axial distance from the image-side surface of the second lens L 2 to the object-side surface of the third lens L 3 ;

d 5 : axial thickness of the third lens L 3 ;

d 6 : axial distance from the image-side surface of the third lens L 3 to the object-side surface of the fourth lens L 4 ;

d 7 : axial thickness of the fourth lens L 4 ;

d 8 : axial distance from the image-side surface of the fourth lens L 4 to the object-side surface of the fifth lens L 5 ;

d 9 : axial thickness of the fifth lens L 5 ;

d 10 : axial distance from the image-side surface of the fifth lens L 5 to the object-side surface of the optical filter GF;

d 11 : axial thickness of the optical filter GF;

d 12 : axial distance from the image-side surface of the optical filter GF to the imaging surface;

nd 1 : refractive index of the first lens L 1 ;

nd 2 : refractive index of the second lens L 2 ;

nd 3 : refractive index of the third lens L 3 ;

nd 4 : refractive index of the fourth lens L 4 ;

nd 5 : refractive index of the fifth lens L 5 ;

ndg: refractive index of the optical filter GF;

v 1 : abbe number of the first lens L 1 ;

v 2 : abbe number of the second lens L 2 ;

v 3 : abbe number of the third lens L 3 ;

v 4 : abbe number of the fourth lens L 4 ;

v 5 : abbe number of the fifth lens L 5 ;

vg: abbe number of the optical filter GF.

Table 3 shows aspheric surface data of each lens in the optical camera lens 10 according to Embodiment 1 of the present disclosure.

Table 4 and Table 5 show the design data of inflection point and stationary point of each lens in the optical camera lens 10 according to Embodiment 1 of the present disclosure. R 1 , R 2 respectively represent the object-side surface and the image-side surface of the first lens L 1 ; R 3 , R 4 respectively represent the object-side surface and the image-side surface of the second lens L 2 ; R 5 , R 6 respectively represent the object-side surface and the image-side surface of the third lens L 3 ; R 7 , R 8 respectively represent the object-side surface and the image-side surface of the fourth lens L 4 ; R 9 , R 10 respectively represent the object-side surface and the image-side surface of the fifth lens L 5 . The data corresponding to the ‘position of inflection point’ column is the vertical distance from the inflection point disposed on each lens surface to the optical axis of the optical camera lens 10 . The data corresponding to the ‘position of stationary point’ column is the vertical distance from the stationary point disposed on each lens surface to the optical axis of the optical camera lens 10 .

FIG. 2 and FIG. 3 respectively show the schematic diagram of the axial chromatic aberration and ratio chromatic aberration of the optical camera lens 10 according to Embodiment 1 after light with a respective wave length of 486 nm, 588 nm and 656 nm passing through the optical camera lens 10 . FIG. 4 shows the schematic diagram of the astigmatism field curvature and distortion of the optical camera lens 10 according to Embodiment 1 after light with a wave length of 588 nm passing through the optical camera lens 10 .

The following table 6 lists values with respect to each conditional expression in the present embodiment according to the above conditional expressions. Obviously, the optical camera system of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the image height of full field of view of the optical camera lens is 2.619 mm, the field of view angle in the diagonal direction is 51.10°

Person skilled in the art shall understand, the above implementing manners are detailed embodiments of the present disclosure, however, in practical application, various modifications may be made to the forms and details thereof, without departing from the spirit and scope of the present disclosure.