Image lens assembly

An image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power is made of plastic material, and has at least one surface being aspheric. The fourth lens element with refractive power is made of plastic material, and has a concave object-side surface and a convex image-side surface, wherein at least one surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface, wherein at least one surface of the fifth lens element is aspheric.

RELATED APPLICATIONS

The application claims priority to Taiwan Application Serial Number 101100474, filed Jan. 5, 2012, which is herein incorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to an image lens assembly. More particularly, the present invention relates to a compact image lens assembly applicable to electronic products.

2. Description of Related Art

In recent years, with the popularity of mobile products with camera functionalities, the demand for miniaturizing an image lens assembly is increasing. The sensor of a conventional photographing camera is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact image lens assemblies have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact image lens assemblies featuring better image quality.

A conventional compact image lens assembly employed in a portable electronic product mainly adopts a four lens elements structure. Due to the popularity of mobile products with high specification, such as smart phones and PDAs (Personal Digital Assistants), the pixel and image quality requirements of the compact image lens assembly have increased rapidly. However, the conventional four lens elements structure cannot satisfy the requirements of the compact image lens assembly.

Another conventional compact image lens assembly provides a five lens elements structure. The image lens assembly with five lens elements can increase the image quality and resolving power thereof. However, the lens element with refractive power which closest to the image side of the image lens assembly is concave which cannot reduce the angle of the incident light on the peripheral region of the fifth lens element, and the photosensitivity would be restricted which lead to image noise.

SUMMARY

According to one aspect of the present disclosure, an image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power is made of plastic material, and has at least one of an object-side surface and an image-side surface being aspheric. The fourth lens element with refractive power is made of plastic material, and has a concave object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fifth lens element is aspheric. When a focal length of the image lens assembly is f, a focal length of the second lens element is f2, an axial distance between the object-side surface of the first lens element and an image plane is TTL, and a maximum image height of the image lens assembly is ImgH, the following relationships are satisfied:
−1.4<f/f2<0; and
TTL/ImgH<2.2.

According to another aspect of the present disclosure, an image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power has at least one of an object-side surface and an image-side surface being aspheric. The fourth lens element with refractive power is made of plastic material, and has a concave object-side surface, wherein at least one of the object-side surface and an image-side surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface is aspheric. The first through fifth lens elements are five independent and non-cemented lens elements. The image lens assembly further includes a stop. When a focal length of the image lens assembly is f, a focal length of the second lens element is f2, an axial distance between the stop and the image-side surface of the fifth lens element is SD, an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, an axial distance between the object-side surface of the first lens element and an image plane is TTL, a maximum image height of the image lens assembly is ImgH, a curvature radius of the image-side surface of the third lens element is R6, and a curvature radius of the object-side surface of the fourth lens element is R7, the following relationships are satisfied:
−1.4<f/f2<0;
0.7<SD/TD<1.1;
TTL/ImgH<2.2; and
|R7/R6|<0.9.

According to yet another aspect of the present disclosure, an image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element with refractive power has at least one of an object-side surface and an image-side surface being aspheric. The fourth lens element with refractive power is made of plastic material and has a concave object-side surface, wherein at least one of the object-side surface and an image-side surface of the fourth lens element is aspheric. The fifth lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fifth lens element is aspheric, and the fifth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof. When an axial distance between the object-side surface of the first lens element and an image plane is TTL, a maximum image height of the image lens assembly is ImgH, a curvature radius of the image-side surface of the third lens element is R6, and a curvature radius of the object-side surface of the fourth lens element is R7, the following relationships are satisfied:
TTL/ImgH<2.2; and
|R7/R6|<0.9.

DETAILED DESCRIPTION

An image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The image lens assembly further includes an image sensor located on an image plane.

The first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element are five independent and non-cemented lens elements. That is, any two lens elements adjacent to each other are not cemented (such as the image-side surface of the first lens element and the object-side surface of the second lens element), and there is an air space between the two lens elements. The manufacture of the cemented lenses is more complex than the manufacture of the non-cemented lenses. Especially, the cemented surfaces of the two lens elements should have accurate curvatures for ensuring the connection between the two lens elements, and the displacement between the cemented surfaces of the two lens elements during cementing the lens elements may affect the optical quality of the image lens assembly. Therefore, the image lens assembly of the present disclosure provides five independent and non-cemented lens elements for improving upon the problem generated by the cemented lens elements.

The first lens element with positive refractive power has a convex object-side surface, so that the total track length of the image lens assembly can be reduced by adjusting the positive refractive power of the first lens element.

The second lens element with negative refractive power can correct the aberration generated from the first lens element with positive refractive power.

The fourth lens element has a concave object-side surface and a convex image-side surface, so that the astigmatism of image lens assembly can be corrected.

The fifth lens element with positive refractive power further reduces the total track length of the image lens assembly. The fifth lens element has a convex object-side surface and a convex image-side surface, and the fifth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof. Therefore, the incident angle of the off-axis field on the image sensor can be effectively minimized and the sensitivity of the image sensor can be enhanced for reducing the image noise.

When a focal length of the image lens assembly is f, and a focal length of the second lens element is f2, the following relationship is satisfied:
−1.4<f/f2<0.

Therefore, the negative refractive power of the second lens element can be adjusted for correcting the aberration generated from the first lens element.

When an axial distance between the object-side surface of the first lens element and an image plane is TTL, and a maximum image height of the image lens assembly is ImgH, the following relationship is satisfied:
TTL/ImgH<2.2.

Therefore, the total track length of the image lens assembly can be reduced so as to maintain the compact size of the image lens assembly for portable electronic products.

Furthermore, TTL and ImgH can satisfy the following relationship:
TTL/ImgH<2.0.

When an axial distance between the image-side surface of the fifth lens element and the image plane is BFL, and the axial distance between the object-side surface of the first lens element and the image plane is TTL, the following relationship is satisfied:
0<BFL/TTL<0.4.

Therefore, the back focal length of the image lens assembly can be adjusted for reducing the total track length of the image lens assembly so as to maintain the compact size of the image lens assembly.

The image lens assembly further includes a stop located between the stop and the second lens element. When an axial distance between the stop and the image-side surface of the fifth lens element is SD, and an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, the following relationship is satisfied:
0.70<SD/TD<1.1.

Therefore, the image lens assembly can have a good balance between the telecentric and wide-angle characteristics, as well as a desirable total track length of the image lens assembly.

When a curvature radius of an image-side surface of the first lens element is R2, and a curvature radius of the object-side surface of the second lens element is R3, the following relationship is satisfied:
|R3/R2|<0.9.

Therefore, the curvatures of the first lens element and the second lens element can correct the astigmatism of the image lens assembly.

When an Abbe number of the first lens element is V1, and an Abbe number of the second lens element is V2, the following relationship is satisfied:
27<V1−V2<40.

Therefore, the chromatic aberration of the image lens assembly can be corrected.

When a central thickness of the fourth lens element is CT4, and a central thickness of the fifth lens element is CT5, the following relationship is satisfied:
0.05<CT4/CT5<0.6.

Therefore, the manufacture of the lens elements and the fabrication of the image lens assembly would be easier.

When a refractive index of the second lens element is N2, the following relationship is satisfied:
1.55<N2<1.7.

Therefore, the proper refractive index of the second lens element can reduce the aberration of the image lens assembly.

When a curvature radius of the image-side surface of the third lens element is R6, and a curvature radius of the object-side surface of the fourth lens element is R7, the following relationship is satisfied:
|R7/R6|<0.9.

Therefore, the aberration of the image lens assembly can be corrected by adjusting the curvatures of the image-side surface of the third lens element and the object-side surface of the fourth lens element.

Furthermore, R7 and R6 can satisfy the following relationship:
|R7/R6|<0.6.

When the focal length of the image lens assembly is f, and a focal length of the fifth lens element is f5, the following relationship is satisfied:
0<f/f5<1.4.

Therefore, the high order aberration of the image lens assembly can be corrected by adjusting the positive refractive power of the fifth lens element.

According to the image lens assembly of the present disclosure, the lens elements thereof can be made of glass or plastic material. When the lens elements are made of glass material, the distribution of the refractive power of the image lens assembly may be more flexible for design. When the lens elements are made of plastic material, the cost of manufacture can be effectively reduced. Furthermore, the surface of each lens element can be aspheric, so that it is easier to make the surface into non-spherical shapes. Consequently, more controllable variables are obtained, and the aberration as well as the number of required lens elements can be reduced while constructing an optical system. Therefore, the total track length of the image lens assembly can also be reduced.

According to the image lens assembly of the present disclosure, when a lens element has a convex surface, it indicates that there is a convex surface at the paraxial region; and when a lens element has a concave surface, indicates that there is a concave surface at the paraxial region.

According to the image lens assembly of the present disclosure, the image lens assembly can include at least one stop, such as an aperture stop, glare stop, field stop, etc. Said glare stop or said field stop is allocated for reducing stray light while retaining high image quality. Furthermore, when a stop is an aperture stop, the position of the aperture stop within an optical system can be arbitrarily placed in front of the entire optical system, within the optical system, or in front of the image plane in accordance with the preference of the optical designer, in order to achieve the desirable optical features or higher image quality produced from the optical system.

According to the above description of the present disclosure, the following 1st-7th specific embodiments are provided for further explanation.

FIG. 1is a schematic view of an image lens assembly according to the 1st embodiment of the present disclosure.FIG. 2shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 1st embodiment. InFIG. 1, the image lens assembly includes, in order from an object side to an image side, an aperture stop100, the first lens element110, the second lens element120, the third lens element130, the fourth lens element140, the fifth lens element150, an IR-cut filter170, an image plane160and an image sensor180.

The first lens element110with positive refractive power has a convex object-side surface111and a concave image-side surface112, and is made of plastic material. The object-side surface111and the image-side surface112of the first lens element110are aspheric.

The second lens element120with negative refractive power has a convex object-side surface121and a concave image-side surface122, and is made of plastic material. The object-side surface121and the image-side surface122of the second lens element120are aspheric.

The third lens element130with positive refractive power has a convex object-side surface131and a convex image-side surface132, and is made of plastic material. The object-side surface131and the image-side surface132of the third lens element130are aspheric.

The fourth lens element140with negative refractive power has a concave object-side surface141and a convex image-side surface142, and is made of plastic material. The object-side surface141and the image-side surface142of the fourth lens element140are aspheric.

The fifth lens element150with positive refractive power has a convex object-side surface151and a convex image-side surface152, and is made of plastic material. The object-side surface151and the image-side surface152of the fifth lens element150are aspheric. Furthermore, the fifth lens element150has inflection points formed on the object-side surface151thereof.

The IR-cut filter170is made of glass, and located between the fifth lens element150and the image plane160, and will not affect the focal length of the image lens assembly.

X is the distance between a point on the aspheric surface spaced at a distance Y from the optical axis and the tangential plane at the aspheric surface vertex on the optical axis;

Y is the distance from the point on the curve of the aspheric surface to the optical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient

In the image lens assembly according to the 1st embodiment, when a focal length of the image lens assembly is f, an f number of the image lens assembly is Fno, and half of the maximal field of view is HFOV, these parameters have the following values:
f=4.61 mm;
Fno=2.80; and
HFOV=31.1 degrees.

In the image lens assembly according to the 1st embodiment, when a refractive index of the second lens element120is N2, the following relationship is satisfied:
N2=1.640.

In the image lens assembly according to the 1st embodiment, when an Abbe number of the first lens element110is V1, and an Abbe number of the second lens element120is V2, the following relationship is satisfied:
V1−V2=32.6.

In the image lens assembly according to the 1st embodiment, when a central thickness of the fourth lens element140is CT4, and a central thickness of the fifth lens element150is CT5, the following relationship is satisfied:
CT4/CT5=0.16.

In the image lens assembly according to the 1st embodiment, when a curvature radius of an image-side surface112of the first lens element110is R2, a curvature radius of the object-side surface121of the second lens element120is R3, a curvature radius of the image-side surface132of the third lens element130is R6 and a curvature radius of the object-side surface141of the fourth lens element140is R7 the following relationships are satisfied:
|R3/R2|=0.47; and
|R7/R6|=0.21.

In the image lens assembly according to the 1st embodiment, when the focal length of the image lens assembly is f, a focal length of the second lens element120is f2, and a focal length of the fifth lens element150is f5, the following relationships are satisfied:
f/f2=−0.87; and
f/f5=0.30.

In the image lens assembly according to the 1st embodiment, when an axial distance between the aperture stop100and the image-side surface152of the fifth lens element150is SD, and an axial distance between the object-side surface111of the first lens element110and the image-side surface152of the fifth lens element150is TD, the following relationship is satisfied:
SD/TD=0.93.

In the image lens assembly according to the 1st embodiment, when an axial distance between the image-side surface152of the fifth lens element150and the image plane160is BFL, an axial distance between the object-side surface111of the first lens element110and the image plane160is TTL, and a maximum image height of the image lens assembly is ImgH which here is a half of the diagonal length of the photosensitive area of the image sensor180on the image plane160, the following relationships are satisfied:
BFL/TTL=0.24; and
TTL/ImgH=1.86.

In Table 1, the curvature radius, the thickness and the focal length are shown in millimeters (mm). Surface numbers 0-14 represent the surfaces sequentially arranged from the object-side to the image-side along the optical axis. In Table 2, k represents the conic coefficient of the equation of the aspheric surface profiles. A1-A16 represent the aspheric coefficients ranging from the 1st order to the 16th order. This information related to Table 1 and Table 2 applies also to the Tables for the remaining embodiments, and so an explanation in this regard will not be provided again.

FIG. 3is a schematic view of an image lens assembly according to the 2nd embodiment of the present disclosure.FIG. 4shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 2nd embodiment. InFIG. 3, the image lens assembly includes, in order from an object side to an image side, an aperture stop200, the first lens element210the second lens element220, the third lens element230, the fourth lens element240, the fifth lens element250, an IR-cut filter270, an image plane260and an image sensor280.

The first lens element210with positive refractive power has a convex object-side surface211and a concave image-side surface212, and is made of plastic material. The object-side surface211and the image-side surface212of the first lens element210are aspheric.

The second lens element220with negative refractive power has a convex object-side surface221and a concave image-side surface222, and is made of plastic material. The object-side surface221and the image-side surface222of the second lens element220are aspheric.

The third lens element230with positive refractive power has a concave object-side surface231and a convex image-side surface232, and is made of plastic material. The object-side surface231and the image-side surface232of the third lens element230are aspheric.

The fourth lens element240with negative refractive power has a concave object-side surface241and a convex image-side surface242, and is made of plastic material. The object-side surface241and the image-side surface242of the fourth lens element240are aspheric.

The fifth lens element250with positive refractive power has a convex object-side surface251and a convex image-side surface252, and is made of plastic material. The object-side surface251and the image-side surface252of the fifth lens element250are aspheric. Furthermore, the fifth lens element250has inflection points formed on the object-side surface251and the image-side surface252thereof.

The IR-cut filter270is made of glass, and located between the fifth lens element250and the image plane260, and will not affect the focal length of the image lens assembly.

In the mage lens assembly according to the 2nd embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3, R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 2nd embodiment. Moreover, these parameters can be calculated from Table 3 and Table 4 as the following values and satisfy the following relationships:

FIG. 5is a schematic view of an image lens assembly according to the 3rd embodiment of the present disclosure.FIG. 6shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 3rd embodiment. InFIG. 5, the image lens assembly includes, in order from an object side to an image side, the first lens element310, an aperture stop300, the second lens element320, the third lens element330, the fourth lens element340, the fifth lens element350, an IR-cut filter370, an image plane360and an image sensor380.

The first lens element310with positive refractive power has a convex object-side surface311and a concave image-side surface312, and is made of glass. The object-side surface311and the image-side surface312of the first lens element310are aspheric.

The second lens element320with negative refractive power has a convex object-side surface321and a concave image-side surface322, and is made of plastic material. The object-side surface321and the image-side surface322of the second lens element320are aspheric.

The third lens element330with negative refractive power has a concave object-side surface331and a convex image-side surface332, and is made of plastic material. The object-side surface331and the image-side surface332of the third lens element330are aspheric.

The fourth lens element340with negative refractive power has a concave object-side surface341and a convex image-side surface342, and is made of plastic material. The object-side surface341and the image-side surface342of the fourth lens element340are aspheric.

The fifth lens element350with positive refractive power has a convex object-side surface351and a convex image-side surface352, and is made of plastic material. The object-side surface351and the image-side surface352of the fifth lens element350are aspheric. Furthermore, the fifth lens element350has inflection points formed on the object-side surface351thereof.

The IR-cut filter370is made of glass, and located between the fifth lens element350and the image plane360, and will not affect the focal length of the image lens assembly.

In the image lens assembly according to the 3rd embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3, R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 3rd embodiment. Moreover, these parameters can be calculated from Table 5 and Table 6 as the following values and satisfy the following relationships:

FIG. 7is a schematic view of an image lens assembly according to the 4th embodiment of the present disclosure.FIG. 8shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 4th embodiment. InFIG. 7, the image lens assembly includes, in order from an object side to an image side, an aperture stop400, the first lens element410the second lens element420, the third lens element430, the fourth lens element440, the fifth lens element450, an IR-cut filter470, an image plane460and an image sensor480.

The first lens element410with positive refractive power has a convex object-side surface411and a concave image-side surface412, and is made of plastic material. The object-side surface411and the image-side surface412of the first lens element410are aspheric.

The second lens element420with negative refractive power has a concave object-side surface421and a concave image-side surface422, and is made of plastic material. The object-side surface421and the image-side surface422of the second lens element420are aspheric.

The third lens element430with positive refractive power has a convex object-side surface431and a concave image-side surface432, and is made of plastic material. The object-side surface431and the image-side surface432of the third lens element430are aspheric.

The fourth lens element440with negative refractive power has a concave object-side surface441and a convex image-side surface442, and is made of plastic material. The object-side surface441and the image-side surface442of the fourth lens element440are aspheric.

The fifth lens element450with positive refractive power has a convex object-side surface451and a convex image-side surface452, and is made of plastic material. The object-side surface451and the image-side surface452of the fifth lens element450are aspheric. Furthermore, the fifth lens element450has inflection points formed on the object-side surface451thereof.

The IR-cut filter470is made of glass, and located between the fifth lens element450and the image plane460, and will not affect the focal length of the image lens assembly.

In the image lens assembly according to the 4th embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3 R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 4th embodiment. Moreover, these parameters can be calculated from Table 7 and Table 8 as the following values and satisfy the following relationships:

FIG. 9is a schematic view of an image lens assembly according to the 5th embodiment of the present disclosure.FIG. 10shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 5th embodiment. InFIG. 9, the image lens assembly includes, in order from an object side to an image side, the first lens element510, an aperture stop500the second lens element520, the third lens element530, the fourth lens element540, the fifth lens element550, an IR-cut filter570, an image plane560and an image sensor580.

The first lens element510with positive refractive power has a convex object-side surface511and a convex object-side surface512, and is made of plastic material. The object-side surface511and the object-side surface512of the first lens element510are aspheric.

The second lens element520with negative refractive power has a convex object-side surface521and a concave image-side surface522, and is made of plastic material. The object-side surface521and the image-side surface522of the second lens element520are aspheric.

The third lens element530with negative refractive power has a concave object-side surface531and a convex image-side surface532, and is made of plastic material. The object-side surface531and the image-side surface532of the third lens element530are aspheric.

The fourth lens element540with negative refractive power has a concave object-side surface541and a convex image-side surface542, and is made of plastic material. The object-side surface541and the image-side surface542of the fourth lens element540are aspheric.

The fifth lens element550with positive refractive power has a convex object-side surface551and a convex image-side surface552, and is made of plastic material. The object-side surface551and the image-side surface552of the fifth lens element550are aspheric. Furthermore, the fifth lens element550has inflection points formed on the object-side surface551thereof.

The IR-cut filter570is made of glass, and located between the fifth lens element550and the image plane560, and will not affect the focal length of the image lens assembly.

In the image lens assembly according to the 5th embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3, R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 5th embodiment. Moreover, these parameters can be calculated from Table 9 and Table 10 as the following values and satisfy the following relationships:

FIG. 11is a schematic view of an image lens assembly according to the 6th embodiment of the present disclosure.FIG. 12shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 6th embodiment. InFIG. 11, the image lens assembly includes, in order from an object side to an image side, the first lens element610, an aperture stop600, the second lens element620, the third lens element630, the fourth lens element640, the fifth lens element650, an IR-cut filter670, an image plane660and an image sensor680.

The first lens element610with positive refractive power has a convex object-side surface611and a convex object-side surface612, and is made of plastic material. The object-side surface611and the object-side surface612of the first lens element610are aspheric.

The second lens element620with negative refractive power has a convex object-side surface621and a concave image-side surface622, and is made of plastic material. The object-side surface621and the image-side surface622of the second lens element620are aspheric.

The third lens element630with negative refractive power has a concave object-side surface631and a convex image-side surface632, and is made of plastic material. The object-side surface631and the image-side surface632of the third lens element630are aspheric.

The fourth lens element640with positive refractive power has a concave object-side surface641and a convex image-side surface642, and is made of plastic material. The object-side surface641and the image-side surface642of the fourth lens element640are aspheric.

The fifth lens element650with positive refractive power has a convex object-side surface651and a convex image-side surface652, and is made of plastic material. The object-side surface651and the image-side surface652of the fifth lens element650are aspheric. Furthermore, the fifth lens element650has inflection points formed on the object-side surface651thereof.

The IR-cut filter670is made of glass, and located between the fifth lens element650and the image plane660, and will not affect the focal length of the image lens assembly.

In the image lens assembly according to the 6th embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3, R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 6th embodiment. Moreover, these parameters can be calculated from Table 11 and Table 12 as the following values and satisfy the following relationships:

FIG. 13is a schematic view of an image lens assembly according to the 7th embodiment of the present disclosure.FIG. 14shows spherical aberration curves, astigmatic field curves and a distortion curve of the image lens assembly according to the 7th embodiment. InFIG. 13, the image lens assembly includes, in order from an object side to an image side, an aperture stop700, the first lens element710the second lens element720, the third lens element730, the fourth lens element740, the fifth lens element750, an IR-cut filter770, an image plane760and an image sensor780.

The first lens element710with positive refractive power has a convex object-side surface711and a concave image-side surface712, and is made of plastic material. The object-side surface711and the image-side surface712of the first lens element710are aspheric.

The second lens element720with negative refractive power has a concave object-side surface721and a convex image-side surface722, and is made of plastic material. The object-side surface721and the image-side surface722of the second lens element720are aspheric.

The third lens element730with negative refractive power has a convex object-side surface731and a concave image-side surface732, and is made of plastic material. The object-side surface731and the image-side surface732of the third lens element730are aspheric.

The fourth lens element740with negative refractive power has a concave object-side surface741and a convex image-side surface742, and is made of plastic material. The object-side surface741and the image-side surface742of the fourth lens element740are aspheric.

The fifth lens element750with positive refractive power has a convex object-side surface751and a convex image-side surface752, and is made of plastic material. The object-side surface751and the image-side surface752of the fifth lens element750are aspheric. Furthermore, the fifth lens element750has inflection points formed on the object-side surface751thereof.

The IR-cut filter770is made of glass, and located between the fifth lens element750and the image plane760, and will not affect the focal length of the image lens assembly.

In the image lens assembly according to the 7th embodiment, the definitions of f, Fno, HFOV, N2, V1, V2, CT4, CT5, R2, R3, R6, R7, f2, f5, SD, TD, BFL, TTL and ImgH are the same as those stated in the 1st embodiment with corresponding values for the 7th embodiment. Moreover, these parameters can be calculated from Table 13 and Table 14 as the following values and satisfy the following relationships: