BACKGROUND
Field of the Invention

The present invention relates to an optical lens assembly and photographing module, and more particularly to an optical lens assembly and photographing module applicable to electronic products.

Description of Related Art

Miniaturized photographing modules with high image resolution have been the standard equipment for various mobile devices, and as the advanced semiconductor manufacturing technologies have allowed the pixel size of image sensors to be reduced and compact, there's an increasing demand for photographing modules featuring finer image resolution and better image quality. However, conventional photographing modules used in mobile devices, such as, mobile phones, tablet computers, and other wearable electronic devices, are often accompanied by the sense of manufacturing and assembly in large optical aperture, which makes mass production difficult and increases the cost of mass production. Or in order to reduce the assembly tolerance, the peripheral image quality must be sacrificed, making the peripheral image blurred or deformed.

The present invention mitigates and/or obviates the aforementioned disadvantages.

SUMMARY

The primary objective of the present invention is to provide an optical lens assembly and photographing module. When a specific condition is satisfied, the optical lens assembly of the present invention can provide a large optical aperture, a large field of view and high image resolution, and has assembly tolerance with low accuracy.

Therefore, an optical lens assembly in accordance with the present invention comprises, in order from an object side to an image side: a stop; a first lens with positive refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the first lens being convex near an optical axis and the image-side surface of the first lens being concave near the optical axis, and the object-side surface and the image-side surface of the first lens being aspheric; a second lens with negative refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the second lens being convex near the optical axis and the image-side surface of the second lens being concave near the optical axis, and the object-side surface and the image-side surface of the second lens being aspheric; a third lens with positive refractive power, comprising an object-side surface and an image-side surface, the image-side surface of the third lens being convex near the optical axis, and the object-side surface and the image-side surface of the third lens being aspheric; a fourth lens with positive refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the fourth lens being concave near the optical axis and the image-side surface of the fourth lens being convex near the optical axis, and the object-side surface and the image-side surface of the fourth lens being aspheric; and a fifth lens with negative refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the fifth lens being concave near the optical axis and the image-side surface of the fifth lens being concave near the optical axis, and the object-side surface and the image-side surface of the fifth lens being aspheric.

Wherein half of a maximum view angle (field of view) of the optical lens assembly is HFOV, a radius of curvature of the object-side surface of the fifth lens is R9, a focal length of the optical lens assembly is f, and following condition is satisfied: −79.81<HFOV*R9/f<−38.47.

The present invention has the following effect: if the above five lenses with refractive power satisfy the condition −79.81<HFOV*R9/f<−38.47, it is favorable to adjust the balance between the focal length of the optical lens assembly and the collection light in large angle, so as to improve the image quality of the optical lens assembly.

Preferably, the optical lens assembly has a total of five lenses with refractive power.

Preferably, the optical lens assembly has the maximum view angle (field of view) FOV, a f-number of the optical lens assembly is Fno, and following condition is satisfied: 34.79<FOV/Fno<58.02, which can effectively collect light in large angle, increase the range receiving area and maintain high image resolution.

Preferably, the optical lens assembly has the maximum view angle (field of view) FOV, an entrance pupil diameter of the optical lens assembly is EPD, and following condition is satisfied: 28.83<FOV/EPD<49.92, which can effectively collect light in large angle and increase the image receiving area.

Preferably, a radius of curvature of the object-side surface of the second lens is R3, a radius of curvature of the object-side surface of the first lens is R1, and following condition is satisfied: 5.37<R3/R1<14.28, which can control the surface changes of the object-side surface of the first lens and the object-side surface of the second lens, so as to correct the aberration.

Preferably, an IR-cut filter is located between the fifth lens and an image plane, the radius of curvature of the object-side surface of the second lens is R3, a radius of curvature of the image-side surface of the fifth lens is R10, a distance from the fifth lens to the IR-cut filter along the optical axis is T5F, and following condition is satisfied: 19.76<(R3/R10)/T5F<46.84, which can reduce the spherical aberration and astigmatism of the optical lens assembly effectively.

Preferably, a radius of curvature of the image-side surface of the first lens is R2, a radius of curvature of the image-side surface of the fourth lens is R8, and following condition is satisfied: −6.11<R2/R8<−3.46, which can reduce the spherical aberration and astigmatism of the optical lens assembly effectively.

Preferably, the radius of curvature of the image-side surface of the first lens is R2, the radius of curvature of the image-side surface of the fifth lens is R10, and following condition is satisfied: 3.09<R2/R10<5.81, which can reduce the spherical aberration and astigmatism of the optical lens assembly effectively.

Preferably, the radius of curvature of the object-side surface of the second lens is R3, a radius of curvature of the image-side surface of the second lens is R4, and following condition is satisfied: 2.32<R3/R4<4.46, which can reduce the spherical aberration and astigmatism of the optical lens assembly effectively.

Preferably, the radius of curvature of the object-side surface of the second lens is R3, the radius of curvature of the image-side surface of the fourth lens is R8, a distance from the image-side surface of the third lens to the object-side surface of the fourth lens along the optical axis is T34, and following condition is satisfied: −41.59<(R3/R8)/T34<−11.45, which is favorable to meet the requirement of miniaturization while reducing the spherical aberration and astigmatism of the optical lens assembly.

Preferably, the radius of curvature of the object-side surface of the fifth lens is R9, a focal length of the fifth lens is f5, and following condition is satisfied: 1.74<R9/f5<3.58, which is favorable to the correction of the high order aberrations and astigmatism of the assembly.

Preferably, a focal length of the second lens is f2, a focal length of the fourth lens is f4, and following condition is satisfied: −5.56<f2/f4<−2.66, so that the distribution of the refractive power of the lens assembly will be appropriate, it will be favorable to correct the aberration of the optical lens assembly and improve the image quality.

Preferably, the focal length of the second lens is f2, the focal length of the fifth lens is f5, and following condition is satisfied: 3.59<f2/f5<7, so that the distribution of the refractive power of the lens assembly will be appropriate, it will be favorable to correct the aberration of the optical lens assembly and improve the image quality.

Preferably, a distance from the object-side surface of the first lens to the image plane along the optical axis is TL, the distance from the image-side surface of the third lens to the object-side surface of the fourth lens along the optical axis is T34, and following condition is satisfied: 7.12<TL/T34<13.93, which is favorable to meet the requirement of miniaturization while balancing the spatial configuration between the third lens and the fourth lens, so as to reduce the sensitivity of the optical lens assembly and the impact of the assembly tolerance.

Preferably, a distance from the image-side surface of the fifth lens to the image plane along the optical axis is BFL, a central thickness of the fifth lens along the optical axis is CT5, and following condition is satisfied: 1.93<BFL/CT5<3.34, which is favorable to balance the miniaturization and the back focal length of the optical lens assembly.

Preferably, the distance from the object-side surface of the first lens to the image plane along the optical axis is TL, a distance from the image-side surface of the fourth lens to the object-side surface of the fifth lens along the optical axis is T45, and following condition is satisfied: 8.88<TL/T45<20, which is favorable to meet the requirement of miniaturization while balancing the spatial configuration between the fourth lens and the fifth lens, so as to reduce the sensitivity of the optical lens assembly and the impact of the assembly tolerance.

A photographing module in accordance with the present invention comprises a lens barrel, an optical lens assembly disposed in the lens barrel, and an image sensor disposed on an image plane of the optical lens assembly.

The optical lens assembly comprises, in order from an object side to an image side: a stop; a first lens with positive refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the first lens being convex near an optical axis and the image-side surface of the first lens being concave near the optical axis, and the object-side surface and the image-side surface of the first lens being aspheric; a second lens with negative refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the second lens being convex near the optical axis and the image-side surface of the second lens being concave near the optical axis, and the object-side surface and the image-side surface of the second lens being aspheric; a third lens with positive refractive power, comprising an object-side surface and an image-side surface, the image-side surface of the third lens being convex near the optical axis, and the object-side surface and the image-side surface of the third lens being aspheric; a fourth lens with positive refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the fourth lens being concave near the optical axis and the image-side surface of the fourth lens being convex near the optical axis, and the object-side surface and the image-side surface of the fourth lens being aspheric; and a fifth lens with negative refractive power, comprising an object-side surface and an image-side surface, the object-side surface of the fifth lens being concave near the optical axis and the image-side surface of the fifth lens being concave near the optical axis, and the object-side surface and the image-side surface of the fifth lens being aspheric.

Wherein half of a maximum view angle (field of view) of the optical lens assembly is HFOV, a radius of curvature of the object-side surface of the fifth lens is R9, a focal length of the optical lens assembly is f, and following condition is satisfied: −79.81<HFOV*R9/f<−38.47.

The present invention has the following effect: if the above five lenses with refractive power satisfy the condition −79.81<HFOV*R9/f<−38.47, it is favorable to adjust the balance between the focal length of the optical lens assembly and the light collection with large angle, so as to improve the image quality of the optical lens assembly.

Preferably, the optical lens assembly has a total of five lenses with refractive power.

Preferably, the optical lens assembly has the maximum view angle (field of view) FOV, a f-number of the optical lens assembly is Fno, and following condition is satisfied: 34.79<FOV/Fno<58.02, which can effectively collect light in large angle, increase the image receiving area and maintain high image resolution.