BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an optical imaging lens set and an electronic device which includes such optical imaging lens set. Specifically speaking, the present invention is directed to an optical imaging lens set of six lens elements and an electronic device which includes such optical imaging lens set of six lens elements.

2. Description of the Prior Art

In recent years, the popularity of mobile phones and digital cameras makes photography modules (including optical imaging lens set, holder and sensor, etc) well developed. Mobile phones and digital cameras become lighter and thinner, so that the miniaturization demands of photography modules get higher and higher. As the charge coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) technologies advance, the size of the photography modules can be shrunk too, but these photography modules still need to maintain good imaging quality.

Conventional optical imaging lens sets are mostly with only four lens elements, and since they have fewer lens elements, the total length of the optical imaging lens set is relatively short. However, as the requirements of good imaging quality increase, the conventional optical imaging lens set of four lens elements can hardly satisfy these requirements. U.S. Pat. Nos. 7,663,814 and 8,040,618 disclose an optical imaging lens set of six lens elements respectively, and all of the total length (the distance between the first object surface of the first lens element to an image plane) of the optical imaging lens sets are over 21 mm. The size of the optical imaging lens set is too big to satisfy the specification requirements of consumer electronics products. Therefore, a novel optical imaging lens set with small total length and good imaging quality is needed.

SUMMARY OF THE INVENTION

In light of the above, the present invention proposes an optical imaging lens set that is lightweight has a low production cost, an enlarged half of field of view, a high resolution and high image quality. The optical imaging lens set of six lens elements of the present invention has a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element sequentially from an object side to an image side along an optical axis.

The present invention provides an optical imaging lens set, from an object side toward an image side in order along an optical axis comprising: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element has an image-side surface with a concave part in a vicinity of its periphery. The second lens element has an image-side surface with a concave part in a vicinity of the optical axis. The third lens element has positive refractive power. The fourth lens element has an object-side surface with a convex part in a vicinity of its circular periphery. The fifth lens element has an object-side surface with a concave part in a vicinity of the optical axis. The sixth lens element having an image-side surface with a concave part in a vicinity of the optical axis. Wherein the optical imaging lens set does not include any lens element with refractive power other than said first, second, third, fourth, fifth and sixth lens elements.

In the optical imaging lens set of six lens elements of the present invention, an air gap G12 along the optical axis is disposed between the first lens element and the second lens element, an air gap G23 along the optical axis is disposed between the second lens element and the third lens element, an air gap G34 along the optical axis is disposed between the third lens element and the fourth lens element, an air gap G45 along the optical axis is disposed between the fourth lens element and the fifth lens element, an air gap G56 along the optical axis is disposed between the fifth lens element and the sixth lens element, and the sum of total five air gaps between adjacent lens elements from the first lens element to the sixth lens element along the optical axis is AAG, AAG=G12+G23+G34+G45+G56.

In the optical imaging lens set of six lens elements of the present invention, the first lens element has a first lens element thickness T1 along the optical axis, the second lens element has a second lens element thickness T2 along the optical axis, the third lens element has a third lens element thickness T3 along the optical axis, the fourth lens element has a fourth lens element thickness T4 along the optical axis, the fifth lens element has a fifth lens element thickness T5 along the optical axis, the sixth lens element has a sixth lens element thickness T6 along the optical axis, and the total thickness of all the lens elements in the optical imaging lens set along the optical axis is ALT, ALT=T1+T2+T3+T4+T5+T6.

In addition, the distance between the image-side surface of the sixth lens element to an image plane along the optical axis is BFL (back focal length); the effective focal length of the optical imaging lens set is EFL.

In the optical imaging lens set of six lens elements of the present invention, the relationship (G12+G34)/T6≤1.7 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship T2/T3≤1.5 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 3≤EFL/G23≤11 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 0.9≤EFL/AAG≤2.6 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship AAG/BFL≤2.1 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 2.8≤EFL/T2 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 1.88≤BFL/(G34+G45) is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship AAG/BFL≤2.1 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 1.5≤BFL/T1 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 1.4≤BFL/T2 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 1.9≤BFL/T2 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship AAG/T3≤3.3 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 4.7≤EFL/T1 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 1.1≤T6/T2 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship AAG/T4≤2.8 is satisfied.

In the optical imaging lens set of six lens elements of the present invention, the relationship 3.5≤EFL/G23≤11 is satisfied.

The present invention also proposes an electronic device which includes the optical imaging lens set as described above. The electronic device includes a case and an image module disposed in the case. The image module includes an optical imaging lens set as described above, a barrel for the installation of the optical imaging lens set, a module housing unit for the installation of the barrel, a substrate for the installation of the module housing unit, and an image sensor disposed on the substrate and at an image side of the optical imaging lens set.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

