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 an object-side surface being convex in a paraxial. The second lens element with refractive power has an object-side surface being concave in a paraxial region. The third lens element with negative refractive power has an object-side surface being convex in a paraxial region and an image-side surface being concave in a paraxial region. The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region and an image-side surface being convex in a paraxial region. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region.

RELATED APPLICATIONS

The application claims priority to Taiwan Application Serial Number 102121155, filed Jun. 14, 2013, which is herein incorporated by reference.

BACKGROUND

1. Technical Field

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

2. Description of Related Art

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

A conventional compact optical system employed in a portable electronic product mainly adopts a structure of four-element lens. Due to the popularity of mobile products with high-end specifications, such as smart phones and PDAs (Personal Digital Assistants), the requirements for high resolution and image quality of modern compact optical systems have been increasing significantly. However, the conventional four-element lens structure cannot satisfy these requirements of the compact optical system.

Although other conventional optical systems with five-element lens structure usually have a rather small axial distance between the first lens element and the second lens element. It is thereby not favorable for disposing the mechanical components, such as an aperture stop or a shutter and causes restrictions in applications.

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 an object-side surface being convex in a paraxial region thereof. The second lens element with refractive power has an object-side surface being concave in a paraxial region thereof. The third lens element with negative refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region. The image lens assembly has a total of five lens elements with refractive power. When a focal length of the second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, an axial distance between the first lens element and the second lens element is T12, and an axial distance between the second lens element and the third lens element is T23, the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<1.15; and
0.75<T12/T23<7.5.

According to another aspect of the present disclosure, an image capturing device includes the image lens assembly according to said aspect and an image sensor. The image sensor located on an image plane side of said image lens assembly.

According to still 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 an object-side surface being convex in a paraxial region thereof. The second lens element with refractive power has an object-side surface being concave in a paraxial region thereof. The third lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The fifth lens element with negative refractive power has an mage-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region. The image lens assembly has a total of five lens elements with refractive power. When a focal length of the second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, a curvature radius of the object-side surface of the first lens element is R1, and a curvature radius of the image-side surface of the first lens element is R2, the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<2.0;
0.75<T12/T23<2.4; and
(R1−R2)/(R1+R2)<0.

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 an object-side surface being convex in a paraxial region thereof. The second lens element with refractive power has an object-side surface being concave in a paraxial region thereof. The third lens element with negative refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region. The image lens assembly has a total of five lens elements with refractive power. When a focal length of the to second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, an axial distance between the first lens element and the second lens element is T12, and an axial distance between the second lens element and the third lens element is T23, the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<2.0; and
0.75<T12/T23<2.4.

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 has a total of five lens elements with refractive power and further includes an image sensor located on an image plane side. More specifically, the image sensor can be located on an image plane.

The first lens element with positive refractive power has an object-side surface being convex in a paraxial region. Therefore, it provides the image lens assembly with the desired positive refractive power which is favorable for reducing the total track length of the image lens assembly.

The second lens element has an object-side surface being concave in a paraxial region thereof and can have an image-side surface being convex in a paraxial region thereof. Therefore, it is favorable for correcting the astigmatism.

The third lens element with negative refractive power can have an object-side surface being convex in a paraxial region thereof and has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface of the third lens element can have at least one convex shape in an off-axis region. It is also favorable for reducing the incident angle of the off-axis on the image plane so as to increase the responding efficiency of the image sensor.

The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, so that it is favorable for reducing the spherical aberration and correcting the astigmatism.

The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface of the fifth lens element has at least one convex shape in an off-axis region. Therefore, the principal point can be positioned away from the image plane so as to reduce both of the back focal length and the total track length of the image lens assembly. It is also favorable for correcting the aberration of the off-axis.

When a focal length of the second lens element is f2, and a focal length of the third lens element is f3, the following relationship is satisfied: −0.90<f3/|f2|<0. Therefore, it is favorable for balancing the refractive powers so as to reduce the aberration. Preferably, the following relationship is satisfied: −0.70<f3/|f2|<0. More preferably, the following relationship is satisfied: −0.45<f3/|f2|<0.

When an axial distance between the first lens element and the second lens element is T12, and a central thickness of the second lens element is CT2, the following relationship is satisfied: 0.65<T12/CT2<2.0. Therefore, the axial distance between the first lens element and the second lens element is proper which is favorable for disposing the mechanical components, such as the aperture stop or the shutter. Preferably, the following relationship is satisfied: 0.65<T12/CT2<1.15.

When the axial distance between the first lens element and the second lens element is T12, and an axial distance between the second lens element and the third lens element is T23, the following relationship is satisfied: 0.75<T12/T23<7.5. Therefore, it is favorable for avoiding rather small axial distance between the lens elements and overcoming difficulties in assembling so as to increase manufacturing yield rate. Preferably, the following relationship is satisfied: 0.75<T12/T23<2.4.

When a curvature radius of the object-side surface of the first lens element is R1, and a curvature radius of an image-side surface of the first lens element is R2, the following relationship is satisfied: (R1−R2)/(R1+R2)<0. Therefore, it is favorable for reducing the spherical aberration and astigmatism of the image lens assembly. Preferably, the following relationship is satisfied: (R1−R2)/(R1+R2)<−0.3. More preferably, the following relationship is satisfied: −2.0<(R1−R2)/(R1+R2)<−0.3.

When a focal length of the image lens assembly is f, and the focal length of the second lens element is f2, the following relationship is satisfied: −0.50<f/f2<0.15. Therefore, it is favorable for balancing the refractive powers and reducing the spherical aberration and correcting the aberration.

When the central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, and a central thickness of the fourth lens element is CT4, the following relationship is satisfied: 1.05<CT4/(CT2+CT3) 2.5. Therefore, it provides favorable moldability and homogeneity for the lens elements during the injection molding process so as to increase manufacturing yield rate

When an Abbe number of the second lens element is V2, and an Abbe number of the third lens element is V3, the following relationship is satisfied: 0.3<V3/V2<0.6. Therefore, the chromatic aberration of the image lens assembly can be corrected.

When a focal length of the first lens element is f1 and the focal length of the third lens element is f3, the following relationship is satisfied: −0.60<f1/f3<0. Therefore, it is favorable for correcting the aberration.

When a curvature radius of the object-side surface of the third lens element is R5, and a curvature radius of the image-side surface of the third lens element is R6, the following relationship is satisfied: 0<R5/R6. Therefore, it is favorable for correcting the astigmatism.

The aforementioned image lens assembly can further include a stop, such as an aperture stop, which is disposed between the first lens element and the second lens element. Therefore, it is favorable for enlarging the field of view of the image lens assembly and thereby provides a wider field of view for the same.

When the focal length of the image lens assembly is f, a focal length of the fourth lens element is f4, and a focal length of the fifth lens element is f5, the following relationship is satisfied: 2.0<f/f4+|f/f5|<5.0. Therefore, it is favorable for balancing the refractive powers so as to keep the image lens assembly more compact.

When the central thickness of the third lens element is CT3, and a distance in parallel with an optical axis from an axial vertex on the image-side surface of the third lens element to a maximum effective diameter position on the image-side surface of the third lens element is SAG32 (when the maximum effective diameter position is closer to the object side of the image lens assembly than the axial vertex, SAG32 has a negative value; and when the maximum effective diameter position is closer to the image side of the image lens assembly than the axial vertex, SAG32 has a positive value), the following relationship is satisfied: −1.5<SAG32/CT3<0. Therefore, it is favorable for processing, manufacturing and assembling the image capturing system so as to keep the image lens assembly more compact.

When the curvature radius of the object-side surface of the third lens element is R5, and the curvature radius of the image-side surface of the third lens element is R6, the following relationship is satisfied: 0<(R5−R6)/(R5+R6)<1. Therefore, it is favorable for further correcting the astigmatism.

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 to design. When the lens elements are made of plastic material, the manufacturing cost can be effectively reduced. Furthermore, surfaces of each lens element can be arranged to be aspheric, because the aspheric surface of the lens element is easy to form a shape other than spherical surface so as to have more controllable variables for eliminating the aberration thereof, and to further decrease the required number of the lens elements. Therefore, the total track length of the image lens assembly can also be reduced.

According to the image lens assembly of the present disclosure, each of an object-side surface and an image-side surface has a paraxial region and an off-axis region. The paraxial region refers to the region of the surface where light rays travel close to an optical axis, and the off-axis region refers to the region of the surface where light rays travel away from the optical axis. Particularly, when the lens element has a convex surface, it indicates that the surface is convex in the paraxial region thereof; and when the lens element has a concave surface, it indicates that the surface is concave in the paraxial region thereof.

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, a glare stop or a field stop. Said glare stop or said field stop is for eliminating the stray light and thereby improving the image resolution thereof.

According to the image lens assembly of the present disclosure, an aperture stop can be configured as a front stop or a middle stop. A front stop disposed between an imaged object and the first lens element can provide a longer distance between an exit pupil of the image lens assembly and an image plane and thereby improves the image-sensing efficiency of an image sensor. A middle stop disposed between the first lens element and the image plane is favorable for enlarging the field of view of the image lens assembly and thereby provides a wider field of view for the same.

According to the image lens assembly of the present disclosure, the image lens assembly is featured with good correction ability and high image quality, and can be applied to 3D (three-dimensional) image capturing applications, in products such as digital cameras, mobile devices and tablets.

According to the present disclosure, an image capturing device is provided. The image capturing device includes the image lens assembly according to the present disclosure, and an image sensor located on an image plane side of said image lens assembly. Accordingly, it is favorable for disposing mechanical components such as the aperture stop or the shutter between the axial distances of the lens elements in the image lens assembly of the image capturing device without restrictions in applications.

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, a first lens element110, an aperture stop100, a second lens element120, a third lens element130, a fourth lens element140, a fifth lens element150, an IR-cut filter170, an image plane160and an image sensor180. The image lens assembly has a total of five lens elements (110-150) with refractive power.

The first lens element110with positive refractive power has an object-side surface111being convex in a paraxial region thereof and an image-side surface112being concave in a paraxial region thereof, and is made of plastic material. The object-side surface111and the image-side surface112of the first lens element110are aspheric.

The second lens element120with positive refractive power has an object-side surface121being concave in a paraxial region thereof and an image-side surface122being convex in a paraxial region thereof, and is made of plastic material. The object-side surface121and the image-side surface122of the second lens element120are aspheric.

The third lens element130with negative refractive power has an object-side surface131being convex in a paraxial region thereof and an image-side surface132being concave in a paraxial region thereof, and is made of plastic material. The object-side surface131and the image-side surface132of the third lens element130are aspheric, wherein the image-side surface132of the third lens element130has one convex shape in an off-axis region.

The fourth lens element140with positive refractive power has an object-side surface141being concave in a paraxial region thereof and an image-side surface142being convex in a paraxial region thereof, and is made of plastic material. The object-side surface141and the image-side surface142of the fourth lens element140are aspheric.

The fifth lens element150with negative refractive power has an object-side surface151being concave in a paraxial region thereof and an image-side surface152being concave in a paraxial region thereof, and is made of plastic material. The object-side surface151and the image-side surface152of the fifth lens element150are aspheric, wherein the image-side surface152of the fifth lens element150has one convex shape in an off-axis region.

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

X is the relative 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 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, 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 of the image lens assembly is HFOV, these parameters have the following values: f=2.85 mm; Fno=2.20; and HFOV=38.0 degrees.

In the image lens assembly according to the 1st embodiment, an Abbe number of the second lens element120is V2, and an Abbe number of the third lens element130is V3, the following relationship is satisfied: V3/V2=0.43.

In the image lens assembly according to the 1st embodiment, a central thickness of the second lens element120is CT2, a central thickness of the third lens element130is CT3, a central thickness of the fourth lens element140is CT4, an axial distance between the first lens element110and the second lens element120is T12, and an axial distance between the second lens element120and the third lens element130is T23, the following relationships are satisfied: T12/CT2=0.83; T12/T23=1.29; and CT4/(CT2+CT3)=1.11.

FIG. 15shows SAG32 of the image-side surface132of the third lens element130of the image lens assembly according to the 1st embodiment. InFIG. 15, the central thickness of the third lens element130is CT3, and a distance in parallel with an optical axis from an axial vertex on the image-side surface132of the third lens element130to a maximum effective diameter position on the image-side surface132of the third lens element130is SAG32, to the following relationship is satisfied: SAG32/CT3=−0.83.

In the image lens assembly according to the 1st embodiment, a curvature radius of the object-side surface111of the first lens element110is R1, a curvature radius of the image-side surface112of the first lens element110is R2, a curvature radius of the object-side surface131of the third lens element130is R5, and a curvature radius of the image-side surface132of the third lens element130is R6, the following relationships are satisfied: (R1−R2)/(R1+R2)=−0.61; (R5−R6)/(R5+R6)=0.78; and R5/R6=8.16.

In the image lens assembly according to the 1st embodiment, the focal length of the image lens assembly is f, a focal length of the first lens element110is f1, a focal length of the second lens element120is f2, a focal length of the third lens element130is f3, a focal length of the fourth lens element140is f4, and a focal length of the fifth lens element150is f5, the following relationships are satisfied: f/f2=0.06; f1/f3=−0.30; f3/|f2|=−0.23; and f/f4+|f/f5|=3.62.

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, a first lens element210, an aperture stop200, a second lens element220, a stop201, a third lens element230, a fourth lens element240, a fifth lens element250, an IR-cut filter270, an image plane260and an image sensor280. The image lens assembly has a total of five lens elements (210-250) with refractive power.

The first lens element210with positive refractive power has an object-side surface211being convex in a paraxial region thereof and an image-side surface212being concave in a paraxial region thereof, 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 an object-side surface221being concave in a paraxial region thereof and an image-side surface222being convex in a paraxial region thereof, and is made of plastic material. The object-side surface221and the image-side surface222of the second lens element220are aspheric.

The third lens element230with negative refractive power has an object-side surface231being convex in a paraxial region thereof and an image-side surface232being concave in a paraxial region thereof, and is made of plastic material. The object-side surface231and the image-side surface232of the third lens element230are aspheric, wherein the image-side surface232of the third lens element230has one convex shape in an off-axis region.

The fourth lens element240with positive refractive power has an object-side surface241being concave in a paraxial region thereof and an image-side surface242being convex in a paraxial region thereof, and is made of plastic material. The object-side surface241and the image-side surface242of the fourth lens element240are aspheric.

The fifth lens element250with negative refractive power has an object-side surface251being convex a paraxial region thereof and an image-side surface252being concave in a paraxial region thereof, and is made of plastic material. The object-side surface251and the image-side surface252of the fifth lens element250are aspheric, wherein the image-side surface252of the fifth lens element250has one convex shape in an off-axis region.

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

In the image lens assembly according to the 2nd embodiment, the definitions of these parameters shown in the following table 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, a first lens element310, an aperture stop300, a second lens element320, a third lens element330, a fourth lens element340, a fifth lens element350, an IR-cut filter370, an image plane360and an image sensor380. The image lens assembly has a total of five lens elements (310-350) with refractive power.

The first lens element310with positive refractive power has an object-side surface311being convex in a paraxial region thereof and an image-side surface312being convex in a paraxial region thereof, and is made of plastic material. The object-side surface311and the image-side surface312of the first lens element310are aspheric.

The second lens element320with positive refractive power has an object-side surface321being concave in a paraxial region thereof and an image-side surface322being convex in a paraxial region thereof, 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 an object-side surface331being convex in a paraxial region thereof and an image-side surface332being concave in a paraxial region thereof, and is made of plastic material. The object-side surface331and the image-side surface332of the third lens element330are aspheric, wherein the image-side surface332of the third lens element330has one convex shape in an off-axis region.

The fourth lens element340with positive refractive power has an object-side surface341being concave in a paraxial region thereof and an image-side surface342being convex in a paraxial region thereof, and is made of plastic material. The object-side surface341and the image-side surface342of the fourth lens element340are aspheric.

The fifth lens element350with negative refractive power has an object-side surface351being convex in a paraxial region thereof and an image-side surface352being concave in a paraxial region thereof, and is made of plastic material. The object-side surface351and the image-side surface352of the fifth lens element350are aspheric, wherein the image-side surface352of the fifth lens element350has one convex shape in an off-axis region.

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

The detailed optical data of the 3rd embodiment are shown in Table 5 and the aspheric surface data shown in Table 6 below.

In the image lens assembly according to the 3rd embodiment, the definitions of these parameters shown in the following table 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, a first lens element410, an aperture stop400, a second lens element420, a third lens element430, a fourth lens element440, a fifth lens element450, an IR-cut filter470, an image plane460and an image sensor480. The image lens assembly has a total of five lens elements (410-450) with refractive power.

The first lens element410with positive refractive power has an object-side surface411being convex in a paraxial region thereof and an image-side surface412being concave in a paraxial region thereof, 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 an object-side surface421being concave in a paraxial region thereof and an image-side surface422being convex in a paraxial region thereof, and is made of plastic material. The object-side surface421and the image-side surface422of the second lens element420are aspheric.

The third lens element430with negative refractive power has an object-side surface431being convex in a paraxial region thereof and an image-side surface432being concave in a paraxial region thereof, and is made of plastic material. The object-side surface431and the image-side surface432of the third lens element430are aspheric, wherein the image-side surface432of the third lens element430has one convex shape in an off-axis region.

The fourth lens element440with positive refractive power has an object-side surface441being concave in a paraxial region thereof and an image-side surface442being convex in a paraxial region thereof, and is made of plastic material. The object-side surface441and the image-side surface442of the fourth lens element440are aspheric.

The fifth lens element450with negative refractive power has an object-side surface451being convex in a paraxial region thereof and an image-side surface452being concave in a paraxial region thereof, and is made of plastic material. The object-side surface451and the image-side surface452of the fifth lens element450are aspheric, wherein the image-side surface452of the fifth lens element450has one convex shape in an off-axis region.

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

In the image lens assembly according to the 4th embodiment, the definitions of these parameters shown in the following table 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, a first lens element510, an aperture stop500, a second lens element520, a third lens element530, a fourth lens element540, a fifth lens element550, an IR-cut filter570, an image plane560and an image sensor580. The image lens assembly has a total of five lens elements (510-550) with refractive power.

The first lens element510with positive refractive power has an object-side surface511being convex in a paraxial region thereof and an image-side surface512being concave in a paraxial region thereof, and is made of plastic material. The object-side surface511and the image-side surface512of the first lens element510are aspheric.

The second lens element520with negative refractive power has an object-side surface521being concave in a paraxial region thereof and an image-side surface522being convex in a paraxial region thereof, 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 an object-side surface531being convex in a paraxial region thereof and an image-side surface532being concave in a paraxial region thereof, and is made of plastic material. The object-side surface531and the image-side surface532of the third lens element530are aspheric, wherein the image-side surface532of the third lens element530has one convex shape in an off-axis region.

The fourth lens element540with positive refractive power has an object-side surface541being concave in a paraxial region thereof and an image-side surface542being convex in a paraxial region thereof, and is made of plastic material. The object-side surface541and the image-side surface542of the fourth lens element540are aspheric.

The fifth lens element550with negative refractive power has an object-side surface551being convex in a paraxial region thereof and an image-side surface552being concave in a paraxial region thereof, and is made of plastic material. The object-side surface551and the image-side surface552of the fifth lens element550are aspheric, wherein the image-side surface552of the fifth lens element550has one convex shape in an off-axis region.

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

In the image lens assembly according to the 5th embodiment, the definitions of these parameters shown in the following table 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, an aperture stop600, a first lens element610, a second lens element620, a third lens element630, a fourth lens element640, a fifth lens element650, an IR-cut filter670, an image plane660and an image sensor680. The image lens assembly has a total of five lens elements (610-650) with refractive power.

The first lens element610with positive refractive power has an object-side surface611being convex in a paraxial region thereof and an image-side surface612being concave in a paraxial region thereof, and is made of plastic material. The object-side surface611and the image-side surface612of the first lens element610are aspheric.

The second lens element620with negative refractive power has an object-side surface621being concave in a paraxial region thereof and an image-side surface622being convex in a paraxial region thereof, 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 an object-side surface631being convex in a paraxial region thereof and an image-side surface632being concave in a paraxial region thereof, 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 an object-side surface641being concave in a paraxial region thereof and an image-side surface642being convex in a paraxial region thereof, and is made of plastic material. The object-side surface641and the image-side surface642of the fourth lens element640are aspheric.

The fifth lens element650with negative refractive power has an object-side surface651being convex in a paraxial region thereof and an image-side surface652being concave in a paraxial region thereof, and is made of plastic material. The object-side surface651and the image-side surface652of the fifth lens element650are aspheric, wherein the image-side surface652of the fifth lens element650has one convex shape in an off-axis region.

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

In the image lens assembly according to the 6th embodiment, the definitions of these parameters shown in the following table 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, a first lens element710, an aperture stop700, a second lens element720, a third lens element730, a fourth lens element740, a fifth lens element750, an IR-cut filter770, an image plane760and an image sensor780. The image lens assembly has a total of five lens elements (710-750) with refractive power.

The first lens element710with positive refractive power has an object-side surface711being convex in a paraxial region thereof and an image-side surface712being concave in a paraxial region thereof, 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 an object-side surface721being concave in a paraxial region thereof and an image-side surface722being convex in a paraxial region thereof, 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 an object-side surface731being concave in a paraxial region thereof and an image-side surface732being concave in a paraxial region thereof, and is made of plastic material. The object-side surface731and the image-side surface732of the third lens element730are aspheric, wherein the image-side surface732of the third lens element730has one convex shape in an off-axis region.

The fourth lens element740with positive refractive power has an object-side surface741being concave in a paraxial region thereof and an image-side surface742being convex in a paraxial region thereof, and is made of plastic material. The object-side surface741and the image-side surface742of the fourth lens element740are aspheric.

The fifth lens element750with negative refractive power has an object-side surface751being convex in a paraxial region thereof and an image-side surface752being concave in a paraxial region thereof, and is made of plastic material. The object-side surface751and the image-side surface752of the fifth lens element750are aspheric, wherein the image-side surface752of the fifth lens element750has one convex shape in an off-axis region.

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

In the image lens assembly according to the 7th embodiment, the definitions of these parameters shown in the following table 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: