Field of the Invention
The present invention relates to a lens assembly.
Description of the Related Art
In recent years, portable electronic products have been gradually developed toward miniaturization and lightweight for people to carry and use conveniently. The lens assemblies that are used for portable electronic products also require miniaturization and lightweight. In addition to miniaturization and lightweight, higher optical performance that can achieve high image quality is desired.
In order to achieve miniaturization, lightweight and high optical performance, the use of aspheric plastic lens for lens design has become a trend. However, only using aspheric plastic lens still has some drawbacks, including a longer total track length of a lens assembly and unsatisfactory resolution. Therefore, there is still a need to solve the aforementioned problems.
The image capturing lens assembly comprises in an order from an object side to an image side thereof: a first lens element with refractive power, a second lens element with refractive power, a third lens element with positive refractive power and having a convex surface facing the image side of the image capturing lens assembly, a fourth lens element with refractive power, wherein −0.967≤f3/f4<−0.5, where f3 is a focal length of the third lens element, and f4 is a focal length of the fourth lens element, a fifth lens element with refractive power, and a sixth lens element with refractive power.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will now be described in detail with reference to the accompanying drawings, wherein the same reference numerals will be used to identify the same or similar elements throughout the several views. It should be noted that the drawings should be viewed in the direction of orientation of the reference numerals.
Detailed structural parameters of the first embodiment of the lens are shown in
where:
Z is the surface sag;
c is curvature;
k is conic constant;
h is the vertical distance from the lens surface to the optical axis; and
A, B, C, D, E, F and G are aspheric coefficients. The aspheric coefficients A, B, C, D, E, F and G are given in Table 2.
The optical filter OF1 is made of glass material. The surface S14 and surface S15 of the optical filter OF1 both are plane surfaces. The image sensor 11 includes a sensor element (not shown).
The image capturing lens assembly 10 of the first embodiment of the present invention is provided with the optical specifications shown in Table 1, which include the focal length, F-number, Total Axial Length, radius of curvature of each lens surface, thickness of each lens, refractive index of each lens and Abbe number of each lens.
V1 is an Abbe number of said first lens element to d light, N1 is a refractivity of said first lens element to d light, wherein d light is a light with a wavelength of 587.6 nm, TTL is a distance along the optical axis from a surface of said first lens element that faces the object side of the image capturing lens assembly to an image sensor, BFL is a distance along the optical axis from a surface of said sixth lens element that faces the image side of the image capturing lens assembly to the image sensor, are shown in
20<V1/N1<35 (1)
0.15<BFL/TTL≤0.218 (2)
−2<f/f6≤−0.991 (3)
−0.967≤f3/f4<−0.5 (4)
By the above arrangements of the lenses and stop STO, the image capturing lens assembly 10 can meet the requirements of optical performance as seen in
It can be seen from
If the value of V1/N1 is greater than 35, the refractive power of the first lens will become less than 1.666, and it will become difficult to shorten the total length of the imaging lens. If the value of V1/N1 is less than 20, the refractive power of the first lens will become greater than 1.666, and it will become difficult to shorten the total length of the imaging lens.
Detailed structural parameters of the second embodiment of the lens are shown in
Where:
Z is the surface sag;
c is curvature of each lens;
k is conic constant;
h is the vertical distance from the lens surface to the optical axis; and
A, B, C, D, E, F and G are aspheric coefficients. The aspheric coefficients A, B, C, D, E, F and G are given in Table 4.
The optical filter OF2 is made of glass material. The surface S214 and surface S215 of the optical filter OF2 both are plane surfaces. The image sensor 21 includes a sensor element (not shown).
The image capturing lens assembly 20 of the second embodiment of the present invention is provided with the optical specifications shown in Table 3, which include the focal length, F-number, Total Axial Length, surface number, radius of curvature of each lens surface, thickness of each lens, refractive index of each lens and Abbe number of each lens.
In the image capturing lens assembly 20, the focal length f=4.488 mm, BFL=1.074 mm, TTL=5.680 mm, f3=12.056 mm, f4=−12.463 mm, f6=−2.784 mm, V1=55.066, and N1=1.666, which can be seen in table 3. As for BFL, 0.2+0.145+0.729133=1.074. The calculated values of various conditions fully satisfy the following requirements:
20<V1/N1<35 (1)
0.15<BFL/TTL≤0.218 (2)
−2<f/f6≤−0.991 (3)
−0.967≤f3/f4<−0.5 (4)
By the above arrangements of the lenses and stop STO, the image capturing lens assembly 20 of the present embodiment can meet the requirements of optical performance as seen in
It can be seen from
Referring to
20<V1/N1<35 (1)
0.15<BFL/TTL≤0.218 (2)
−2<f/f6≤−0.991 (3)
−0.967≤f3/f4<−0.5 (4)
By the above arrangements of the lenses and stop STO, the image capturing lens assembly 30 of the present embodiment can meet the requirements of optical performance as seen in
20<V1/N1<35 (1)
0.15<BFL/TTL≤0.218 (2)
−2<f/f6≤0.991 (3)
−0.967≤f3/f4<−0.5 (4)
By the above arrangements of the lenses and stop STO, the image capturing lens assembly 40 of the present embodiment can meet the requirements of optical performance as seen in
20<V1/N1<35 (1)
0.15<BFL/TTL≤0.218 (2)
−2<f/f6≤−0.991 (3)
−0.967≤f3/f4<−0.5 (4)
By the above arrangements of the lenses and stop STO, the image capturing lens assembly 50 of the present embodiment can meet the requirements of optical performance as seen in
The image capturing lens assembly has satisfied the condition: 20<V1/N1<35. Therefore, the image capturing lens has a shortened total axial length.
The third lens has a convex surface facing the image side of the image capturing lens assembly and the image capturing lens assembly has satisfied the conditions: 0.967≤f3/f4<−0.5, 0.15<BFL/TTL≤0.218 and −2<f/f6≤−0.991. Thus, the image capturing lens has an effectively aberration correction and an improved resolution.
The invention being thus described, it will be clear that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
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2014 1 0742324 | Dec 2014 | CN | national |
Number | Name | Date | Kind |
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8717685 | Tsai | May 2014 | B2 |
20140218582 | Chen | Aug 2014 | A1 |
Number | Date | Country |
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104007532 | Aug 2014 | CN |
201331623 | Aug 2013 | TW |
Number | Date | Country | |
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20160161721 A1 | Jun 2016 | US |