Imaging optical lens, imaging apparatus and electronic device

An imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side: a first lens element; a second lens element having an image-side surface being concave in a paraxial region thereof, a third lens element having an object-side surface being convex in a paraxial region thereof, a fourth lens element, a fifth lens element, and a sixth lens element having negative refractive power.

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number 106135318, filed on Oct. 16, 2017, which is incorporated by reference herein in its entirety.

BACKGROUND

Technical Field

The present disclosure relates to an imaging optical lens and an imaging apparatus, and more particularly, to an imaging optical lens and an imaging apparatus applicable to electronic devices.

Description of Related Art

With rapid developments in technology, shooting lenses are even wildly utilized in various fields such that demands to the shooting lenses with wide angle of view and high image quality are increasing. Meanwhile, for scenes such as dynamic photography and night shooting, shooting lenses with large aperture are indispensible. Also, with growing popularities of portable devices, requirements to the size of the shooting lenses are becoming even harsher.

Due to shapes and interspacing of lens elements of conventional shooting lenses not being properly arranged, balances among image qualities, view angles, apertures, and sizes cannot be easily obtained. Thus, miniaturized shooting lenses with high image quality, wide angle of view and large aperture are required.

SUMMARY

According to one aspect of the present disclosure, an imaging optical lens, includes six lens elements, the six lens elements being, in order from an object side to an image side: a first lens element having positive refractive power; a second lens element having an image-side surface being concave in a paraxial region thereof; a third lens element having an object-side surface being convex in a paraxial region thereof; a fourth lens element; a fifth lens element; and a sixth lens element having negative refractive power,wherein at least one of an object-side surface of the sixth lens element and an image-side surface of the sixth lens element has at least one critical point in an off-axis region thereof, 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, a focal length of the imaging optical lens is f, a curvature radius of an object-side surface of the fourth lens element is R7, a curvature radius of an image-side surface of the fourth lens element is R8, a curvature radius of an image-side surface of the fifth lens element is R10, and the following conditions are satisfied:
0<CT2/T12<1.75;
0≤f/|R7|+f/|R8|<1.32; and
0≤f/R10.

According to another aspect of the present disclosure, an imaging apparatus includes the aforementioned imaging optical lens and an image sensor disposed on an image surface of the imaging optical lens.

According to another aspect of the present disclosure, an electronic device includes the aforementioned imaging apparatus.

According to another aspect of the present disclosure, an imaging optical lens, includes six lens elements, the six lens elements being, in order from an object side to an image side: a first lens element having positive refractive power; a second lens element having negative refractive power; a third lens element having an object side-surface being convex in a paraxial region thereof; a fourth lens element; a fifth lens element having positive refractive power; and a sixth lens element,wherein at least one of an object-side surface of the fifth lens element, an image-side surface of the fifth lens element, an object-side surface of the sixth lens element, and an image-side surface of the sixth lens element has at least one critical point in an off-axis region thereof, 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, a focal length of the imaging optical lens is f, a curvature radius of an object-side surface of the fourth lens element is R7, a curvature radius of an image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, a focal length of the first lens element is f1, a focal length of the sixth lens element is f6, and the following conditions are satisfied:
0<CT2/T12<4.25;
0≤f/|R7|+f/|R8|<1.32;
0≤f/R9; and
0.30<|f1/f6|<0.90.

According to another aspect of the present disclosure, an imaging optical lens, includes six lens elements, the six lens elements being, in order from an object side to an image side: a first lens element having positive refractive power; a second lens element having an object-side surface being convex in a paraxial region thereof; a third lens element having an object-side surface being convex in a paraxial region thereof; a fourth lens element; a fifth lens element; and a sixth lens element,wherein 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, a focal length of the imaging optical lens is f, a curvature radius of an object-side surface of the fourth lens element is R7, a curvature radius of an image-side surface of the fourth lens element is R8, a curvature radius of an image-side surface of the fifth lens element is R10, a focal length of the first lens element is f1, a focal length of the sixth lens element is f6, and the following conditions are satisfied:
0<CT2/T12<2.15;
0≤f/|R7|+f/|R8|≤1.00;
0≤f/R10; and
0.30<|f1/f6|<0.90.

DETAILED DESCRIPTION

The present disclosure provides an imaging optical lens including six lens elements, the six lens elements being, 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, a fifth lens element, and a sixth lens element.

The first lens element has positive refractive power such that a total track length of the lens can be reduced for miniaturization.

The second lens element may have negative refractive power such that aberrations resulted from the first lens element can be balanced. The second lens element may have an object-side surface being convex in a paraxial region thereof such that incident angle of light onto the second lens element can be reduced so as to reduce surface reflections and further reduce occurrences of stray light. The second lens element may have an image-side surface being concave such that corrections of astigmatisms can be enhanced.

The third lens element has an object-side surface being convex in a paraxial region such that occurrences of spherical aberrations can be reduced. Besides, the third lens element may have positive refractive power such that positive refractive power of the lens can be distributed for avoiding excess spherical aberrations due to a reduction of the total track length and reducing the sensitivity. The third lens element may have an image-side surface being concave in a paraxial region such that a principal point can be shifted toward the object side and the total track length can be favorably reduced.

The fifth lens element may have positive refractive power such that the distribution of the refractive power of the lens can be balanced for reducing aberrations and the sensitivity.

The sixth lens element may have negative refractive power for correcting Petzval sum of the lens so as to make an image surface more flat. The sixth lens element may have an object-side surface being convex in a paraxial region so as to favorably correct field curvature in an off-axis region and increase the image quality in a peripheral region. The sixth lens element may have an image-side surface being concave in a paraxial region so as to favorably reduce a back focal length and further reduce the total track length.

At least one of an object-side surface of the fifth lens element, an image-side surface of the fifth lens element, the object-side surface of the sixth lens element and the image-side surface of the sixth lens element has at least one critical point in an off-axis region thereof so as to correct off-axis aberrations and favorably adjust incident and exit angles of light in a peripheral region for reducing surface reflections. Incident angles of light onto the image surface can also be reduced such that response efficiency of an image sensor can be increased. Preferably, at least one of the object-side surface of the sixth lens element and the image-side surface of the sixth lens element has at least one critical point in the off-axis region thereof so as to further correct off-axis aberrations. Preferably, the image-side surface of the sixth lens element has at least one critical point in the off-axis region thereof.

When 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 the following condition can be satisfied: 0<CT2/T12<4.25, sufficient space can be provided between the first lens element and the second lens element and the second lens element can have suitable thickness thereby so as to correct aberrations resulted from the first lens element due to a reduction of the total track length and make the image sharper. Preferably, the following condition can be satisfied: 0<CT2/T12<2.15. Preferably, the following condition can be satisfied: 0<CT2/T12<1.75.

When a focal length of the imaging optical lens is f, a curvature radius of an object-side surface of the fourth lens element is R7, a curvature radius of an image-side surface of the fourth lens element is R8, and the following condition can be satisfied: 0≤f/|R7|+f/|R8|<1.32, the shape of the fourth lens element can be adjusted so as to correct off-axis aberrations and suitable incident and exit angles of light onto the fourth lens element can be obtained such that area of the image surface can be favorably increased and outer diameters of lens elements located in the front end of the imaging optical lens can be reduced. Preferably, the following condition can be satisfied: 0≤f/|R7|+f/|R8|≤1.00. Preferably, the following condition can be satisfied: 0≤f/|R7|+f/|R8|<0.90. Preferably, the following condition can be satisfied: 0≤f/|R7|+f/|R8|<0.50.

When the focal length of the imaging optical lens is f, a curvature radius of the object-side surface of the fifth lens element is R9, and the following condition can be satisfied: 0≤f/R9, aberrations can be corrected while avoiding the shape of the fifth lens element from being overly curved such that difficulties in forming and assembling the lens elements can be decreased and a yield rate can be favorably increased.

When the focal length of the imaging optical lens is f, a curvature radius of the image-side surface of the fifth lens element is R10, and the following condition can be satisfied: 0≤f/R10, shapes of the fifth lens element and the sixth lens element can function corporately for correcting off-axis aberrations.

When a focal length of the first lens element is f1, a focal length of the sixth lens element is f6, and the following condition can be satisfied: |f1/f6|<1.10, distributions of the refractive power of the lens can be adjusted such that the total track length can be suitably reduced for miniaturization. Preferably, the following condition can be satisfied: |f1/f6|<0.90. Preferably, the following condition can be satisfied: 0.30<|f1/f6|<0.90.

When a maximum refractive index among refractive indices of the six lens element is Nmax, and the following condition can be satisfied: 1.650≤Nmax<1.750, distributions of the refractive power of the lens can be adjusted such that light can be refracted more easily so as to favorably correct aberrations and reduce volume.

When an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, and the following condition can satisfied: 58.0<V3+V4<103.0, arrangements of materials of the third lens element and the fourth lens element can be adjusted so as to favorably reduce aberrations such as chromatic aberrations.

When the Abbe number of the third lens element is V3, the Abbe number of the fourth lens element is V4, and the following conditions can be satisfied: |V3−V4|<24.0, the third lens element and the fourth lens element can function corporately with each other for favorably reducing off-axis aberrations.

When the 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, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, and the following conditions can be satisfied: T12/T56<1.0, T23/T56<1.0, T34/T56<1.0, and T45/T56<1.0, arrangements of spacing between the lens element can be suitably adjusted so as to favorably correct off-axis aberrations and reduce the total track length.

When the axial distance between the first lens element and the second lens element is T12, the axial distance between the third lens element and the fourth lens element is T34, and the following condition can be satisfied: 1.21<T34/T12<5.70, spacing between the lens elements can be maintained in suitable ratio so as to favorably reduce the size and increase angle of view of the lens.

When a maximum axial distance between any two adjacent lens elements among the six lens elements is ATmax, a minimum axial distance between any two adjacent lens elements among the six lens elements is ATmin, and the following condition can be satisfied: 1.0<ATmax/ATmin<5.0, a certain spacing can be maintained between the lens elements so as to favorably correct off-axis aberrations.

When the focal length of the imaging optical lens is f, a curvature radius of the object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, and the following condition can be satisfied: 1.05<f/|R5|+f/|R6|<6.00, shape of the third lens element can be adjusted so as to favorably correct off-axis aberrations and reduce volume.

When the focal length of the imaging optical lens is f, a composite focal length of the third lens element and the fourth lens element is f34, and the following condition can be satisfied: 0<f34/f<10.0, the third lens element and the fourth lens element can function cooperatively with each other such that the refractive power can be maintained in a suitable strength so as to favorably reduce the total track length and adjust optical path for increasing illuminations onto the image surface.

When the focal length of the imaging optical lens is f, a composite focal length of the fourth lens element and the fifth lens element is f45, and the following condition can be satisfied: 0<f45/f<6.60, the fourth lens element and the fifth lens element can function corporately with each other for reducing off-axis aberrations.

When an axial distance between an object-side surface of the first lens element and the image surface is TL, an entrance pupil diameter of the imaging optical lens is EPD, and the following condition can be satisfied: 0.8<TL/EPD<2.4, the total track length can be reduced and the aperture can be enlarged such that a suitable ratio can be maintained so as to reduce difficulties while manufacturing.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, a maximum image height of the imaging optical lens is ImgH, and the following condition can be satisfied: 0.8<TL/ImgH<1.5, the total track length can be reduced, the area of the image surface can be increased and incident angle of light onto the image surface can be suitable adjusted so as to maintain the response efficiency of the image sensor.

When at least five lens elements among the sixth lens elements have both a curvature radius of an object-side surface and a curvature radius of an image-side surface thereof being positive, the lens can be suitably utilized in the design of large aperture and short total track length.

When the focal length of the imaging optical lens is f, a focal length of the fifth lens element is f5, and the following condition can be satisfied: 1.6<f5/f<10, the fifth lens element can have suitable amount of positive refractive power so as to favorably reduce the total track length.

When three consecutive lens elements among the six lens elements have Abbe numbers lower than 48, functions of the lens to correct chromatic aberration can be distributed so as to reduce sensitivities of the lens elements and increase a yield rate while manufacturing and assembling.

Each of the aforementioned features of the imaging optical lens can be utilized in numerous combinations, so as to achieve the corresponding effects.

According to the imaging optical lens of the present disclosure, the critical point is a non-axial point on the surface of the lens element where a tangential plane of the point is perpendicular to an optical axis.

According to the imaging optical lens 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 imaging optical lens 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 (ASP). Since these aspheric surfaces can be easily formed into shapes other than spherical shapes so as to have more controllable variables for eliminating aberrations and to further decrease the required quantity of lens elements, the total track length of the imaging optical lens can be effectively reduced.

According to the imaging optical lens of the present disclosure, if a surface of a lens element is aspheric, it means that the surface has an aspheric shape throughout its optically effective area, or a portion(s) thereof.

According to the imaging optical lens of the present disclosure, the imaging optical lens can include at least one stop, such as an aperture stop, a glare stop or a field stop, so as to favorably reduce the amount of stray light and thereby improving the image quality.

According to the imaging optical lens of the present disclosure, the aperture stop can be configured as a front stop or a middle stop. The front stop disposed between an imaged object and the first lens element can provide a longer distance between the exit pupil and the image surface so that there is a telecentric effect for improving the image-sensing efficiency of an image sensor, such as a CCD or CMOS sensor. The middle stop disposed between the first lens element and the image surface is favorable for enlarging the field of view, thereby providing the imaging optical lens with the advantage of a wide-angle lens.

According to the imaging optical lens of the present disclosure, when the lens element has a convex surface and the region of convex shape is not defined, it indicates that the surface can be convex in the paraxial region thereof. When the lens element has a concave surface and the region of concave shape is not defined, it indicates that the surface can be concave in the paraxial region thereof. Likewise, when the region of refractive power or focal length of a lens element is not defined, it indicates that the region of refractive power or focal length of the lens element can be in the paraxial region thereof.

According to the imaging optical lens of the present disclosure, the image surface of the imaging optical lens, based on the corresponding image sensor, can be a plane or a curved surface with an arbitrary curvature, especially a curved surface being concave facing towards the object side. Meanwhile, the imaging optical lens of the present disclosure may optionally include one or more image correction components (such as a field flattener) between the image surface and the most nearing lens element to the image surface so as to achieve the effect of image correction (such as the field curvature). The optical properties of the image correction components such as curvatures, thicknesses, indices, positions and shapes (convex or concave, spherical or aspheric, diffractive surface and Fresnel surface, etc.) can be adjusted according to the requirement of the imaging apparatus. In general, a preferred image correction component may be a thin plano-concave component having a surface being concave toward the object side and be arranged near to the image surface.

According to the above descriptions of the present disclosure, the following 1st-12th specific embodiments are provided for further explanation.

FIG. 1Ais a schematic view of an imaging apparatus according to the 1st embodiment of the present disclosure.FIG. 1Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 1st embodiment.

InFIG. 1A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor190. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element110, a second lens element120, a third lens element130, a fourth lens element140, a fifth lens element150, and a sixth lens element160and no other lens elements are inserted between the first lens element110and the sixth lens element160.

The first lens element110with positive refractive power has an object-side surface111being convex in a paraxial region thereof, an image-side surface112being concave in a paraxial region thereof, and both the object-side surface111and the image-side surface112being aspheric. The first lens element110is made of plastic material.

The second lens element120with negative refractive power has an object-side surface121being convex in a paraxial region thereof, an image-side surface122being concave in a paraxial region thereof, and both the object-side surface121and the image-side surface122being aspheric. The second lens element120is made of plastic material.

The third lens element130with positive refractive power has an object-side surface131being convex in a paraxial region thereof, an image-side surface132being concave in a paraxial region thereof, and both the object-side surface131and the image-side surface132being aspheric. The third lens element130is made of plastic material.

The fourth lens element140has an object-side surface141being planar in a paraxial region thereof, an image-side surface142being planar in a paraxial region thereof, and both the object-side surface141and the image-side surface142being aspheric. The fourth lens element140is made of plastic material.

The fifth lens element150with positive refractive power has an object-side surface151being convex in a paraxial region thereof, an image-side surface152being concave in a paraxial region thereof, both the object-side surface151and the image-side surface152being aspheric, and at least one critical point in both an off-axis region of the object-side surface151and an off-axis region of the image-side surface152thereof. The fifth lens element150is made of plastic material.

The sixth lens element160with negative refractive power has an object-side surface161being convex in a paraxial region thereof, an image-side surface162being concave in a paraxial region thereof, both the object-side surface161and the image-side surface162being aspheric, and at least one critical point in both an off-axis region of the object-side surface161and an off-axis region of the image-side surface162thereof. The sixth lens element160is made of plastic material.

In the imaging optical lens, each of the first lens element110, the second lens element120, the third lens element130, the fifth lens element150and the sixth lens element160has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element120, the third lens element130, and the fourth lens element140, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop100disposed at an object side of the first lens element110, a stop101disposed between the second lens element120and the third lens element130, and a filter170disposed between the sixth lens element160and an image surface180. The filter170is made of glass material and will not affect a focal length of the imaging optical lens. The image sensor190is disposed on or near the image surface180of the imaging optical lens.

Please refer toFIG. 11, which is a schematic view showing the at least one critical point of the 1st embodiment of the present disclosure as an example. Please note the definitions of these characters exemplarily shown inFIG. 11are also applicable to any one of the other embodiments of the present disclosure. The fifth lens element150has the at least one critical point CP51in the off-axis region of the object-side surface151thereof and the at least one critical point CP52in the off-axis region of the image-side surface152thereof. The sixth lens element160has the at least one critical point CP61a, CP61bin the off-axis region of the object-side surface161thereof and the at least one critical point CP62in the off-axis region of the image-side surface162thereof.

The detailed optical data of the 1st embodiment are shown in TABLE 1, and the aspheric surface data are shown in TABLE 2, wherein the units of the curvature radius, the thickness and the focal length are expressed in mm, f is the focal length of the imaging optical lens, Fno is an f-number of the imaging optical lens, and HFOV is half of a maximal field of view, and surfaces #1 to #17 refer to the surfaces in order from the object side to the image side. The aspheric surface data are shown in TABLE 2, wherein k is the conic coefficient in the equation of the aspheric surface profiles, and A4-A20 refer to the 4th to 20th order aspheric coefficients.

Further, it should be noted that the tables shown in each of the following embodiments are associated with the schematic view and diagrams of longitudinal spherical aberration curves, astigmatic field curves and a distortion curve for the respective embodiment. Also, the definitions of the parameters presented in later tables are the same as those of the parameters presented in TABLE 1 and TABLE 2 for the 1st embodiment. Explanations in this regard will not be provided again.

The equation of the aspheric surface profiles is expressed as follows:

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 vertical distance from the point on the aspheric surface profile to the optical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient.

In the 1st embodiment, the focal length of the imaging optical lens is f, the f-number of the imaging optical lens is Fno, half of the maximal field of view of the imaging optical lens is HFOV, and these parameters have the following values: f=5.25 mm; Fno=1.90; and HFOV=41.1 degrees.

In the 1st embodiment, a maximum refractive index among refractive indices of the six lens element is Nmax, and it satisfies the condition: Nmax=1.660, which is the refractive index of the second lens element120.

In the 1st embodiment, an Abbe number of the third lens element130is V3, an Abbe number of the fourth lens element140is V4, and they satisfy the condition: V3+V4=80.9.

In the 1st embodiment, the Abbe number of the third lens element130is V3, the Abbe number of the fourth lens element140is V4, and they satisfy the condition: |V3-V4|=0.

In the 1st embodiment, a maximum axial distance between any two adjacent lens elements among the six lens elements is ATmax, a minimum axial distance between any two adjacent lens elements among the six lens elements is ATmin, and they satisfy the condition: ATmax/ATmin=3.09. In the present embodiment, ATmax=0.756 (mm), which is an axial distance between the fifth lens element150and the sixth lens element160, and ATmin=0.245 (mm), which is an axial distance between the fourth lens element140and the fifth lens element150.

In the 1st embodiment, a central thickness of the second lens element120is CT2, an axial distance between the first lens element110and the second lens element120is T12, and they satisfy the condition: CT2/T12=0.43.

In the 1st embodiment, the axial distance between the first lens element110and the second lens element120is T12, the axial distance between the fifth lens element150and the sixth lens element160is T56, and they satisfy the condition: T12/T56=0.37.

In the 1st embodiment, an axial distance between the second lens element120and the third lens element130is T23, the axial distance between the fifth lens element150and the sixth lens element160is T56, and they satisfy the condition: T23/T56=0.42.

In the 1st embodiment, the axial distance between the first lens element110and the second lens element120is T12, an axial distance between the third lens element130and the fourth lens element140is T34, and they satisfy the condition: T34/T12=1.75.

In the 1st embodiment, the axial distance between the third lens element130and the fourth lens element140is T34, the axial distance between the fifth lens element150and the sixth lens element160is T56, and they satisfy the condition: T34/T56=0.64.

In the 1st embodiment, the axial distance between the fourth lens element140and the fifth lens element150is T45, the axial distance between the fifth lens element150and the sixth lens element160is T56, and they satisfy the condition: T45/T56=0.32.

In the 1st embodiment, the focal length of the imaging optical lens is f, a curvature radius of the object-side surface131of the third lens element130is R5, a curvature radius of the image-side surface132of the third lens element130is R6, and they satisfy the condition: f/|R5|+f/R6|=1.26.

In the 1st embodiment, the focal length of the imaging optical lens is f, a curvature radius of the object-side surface141of the fourth lens element140is R7, a curvature radius of the image-side surface142of the fourth lens element140is R8, and they satisfy the condition: f/R7|+f/|R8|=0.00.

In the 1st embodiment, the focal length of the imaging optical lens is f, a curvature radius of the object-side surface151of the fifth lens element150is R9, and they satisfy the condition: f/R9=2.10.

In the 1st embodiment, the focal length of the imaging optical lens is f, a curvature radius of the image-side surface152of the fifth lens element150is R10, and they satisfy the condition: f/R10=1.49.

In the 1st embodiment, a focal length of the first lens element110is f1, a focal length of the sixth lens element160is f6, and they satisfy the condition: |f1/f6|=0.68.

In the 1st embodiment, the focal length of the imaging optical lens is f, a composite focal length of the third lens element130and the fourth lens element140is f34, and they satisfy the condition: f34/f=2.97.

In the 1st embodiment, the focal length of the imaging optical lens is f, a composite focal length of the fourth lens element140and the fifth lens element150is f45, and they satisfy the condition: f45/f=2.52.

In the 1st embodiment, the focal length of the imaging optical lens is f, a focal length of the fifth lens element150is f5, and they satisfy the condition: f5/f=2.52.

In the 1st embodiment, an axial distance between the object-side surface111of the first lens element110and the image surface180is TL, an entrance pupil diameter of the imaging optical lens is EPD, and they satisfy the condition: TL/EPD=2.31.

In the 1st embodiment, the axial distance between the object-side surface111of the first lens element110and the image surface180is TL, a maximum image height of the imaging optical lens is ImgH, and they satisfy the condition: TL/ImgH=1.39.

FIG. 2Ais a schematic view of an imaging apparatus according to the 2nd embodiment of the present disclosure.FIG. 2Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 2nd embodiment.

InFIG. 2A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor290. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element210, a second lens element220, a third lens element230, a fourth lens element240, a fifth lens element250, and a sixth lens element260and no other lens elements are inserted between the first lens element210and the sixth lens element260.

The first lens element210with positive refractive power has an object-side surface211being convex in a paraxial region thereof, an image-side surface212being concave in a paraxial region thereof, and both the object-side surface211and the image-side surface212being aspheric. The first lens element210is made of plastic material.

The second lens element220with negative refractive power has an object-side surface221being convex in a paraxial region thereof, an image-side surface222being concave in a paraxial region thereof, and both the object-side surface221and the image-side surface222being aspheric. The second lens element220is made of plastic material.

The third lens element230with positive refractive power has an object-side surface231being convex in a paraxial region thereof, an image-side surface232being convex in a paraxial region thereof, and both the object-side surface231and the image-side surface232being aspheric. The third lens element230is made of plastic material.

The fourth lens element240with negative refractive power has an object-side surface241being concave in a paraxial region thereof, an image-side surface242being convex in a paraxial region thereof, and both the object-side surface241and the image-side surface242being aspheric. The fourth lens element240is made of plastic material.

The fifth lens element250with positive refractive power has an object-side surface251being convex in a paraxial region thereof, an image-side surface252being concave in a paraxial region thereof, both the object-side surface251and the image-side surface252being aspheric, and at least one critical point in both an off-axis region of the object-side surface251and an off-axis region of the image-side surface252thereof. The fifth lens element250is made of plastic material.

The sixth lens element260with negative refractive power has an object-side surface261being convex in a paraxial region thereof, an image-side surface262being concave in a paraxial region thereof, both the object-side surface261and the image-side surface262being aspheric, and at least one critical point in both an off-axis region of the object-side surface261and an off-axis region of the image-side surface262thereof. The sixth lens element260is made of plastic material.

In the imaging optical lens, three consecutive lens elements, the second lens element220, the third lens element230, and the fourth lens element240, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop200disposed at an object side of the first lens element210, a stop201disposed between the second lens element220and the third lens element230, and a filter270disposed between the sixth lens element260and an image surface280. The filter270is made of glass material and will not affect a focal length of the imaging optical lens. The image sensor290is disposed on or near the image surface280of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 3 and TABLE 4 and satisfy the conditions stated in table below.

FIG. 3Ais a schematic view of an imaging apparatus according to the 3rd embodiment of the present disclosure.FIG. 3Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 3rd embodiment.

InFIG. 3A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor390. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element310, a second lens element320, a third lens element330, a fourth lens element340, a fifth lens element350, and a sixth lens element360and no other lens elements are inserted between the first lens element310and the sixth lens element360.

The first lens element310with positive refractive power has an object-side surface311being convex in a paraxial region thereof, an image-side surface312being concave in a paraxial region thereof, and both the object-side surface311and the image-side surface312being aspheric. The first lens element310is made of plastic material.

The second lens element320with negative refractive power has an object-side surface321being convex in a paraxial region thereof, an image-side surface322being concave in a paraxial region thereof, and both the object-side surface321and the image-side surface322being aspheric. The second lens element320is made of plastic material.

The third lens element330with positive refractive power has an object-side surface331being convex in a paraxial region thereof, an image-side surface332being concave in a paraxial region thereof, and both the object-side surface331and the image-side surface332being aspheric. The third lens element330is made of plastic material.

The fourth lens element340with positive refractive power has an object-side surface341being convex in a paraxial region thereof, an image-side surface342being convex in a paraxial region thereof, and both the object-side surface341and the image-side surface342being aspheric. The fourth lens element340is made of plastic material.

The fifth lens element350with positive refractive power has an object-side surface351being convex in a paraxial region thereof, an image-side surface352being concave in a paraxial region thereof, both the object-side surface351and the image-side surface352being aspheric, and at least one critical point in both an off-axis region of the object-side surface351and an off-axis region of the image-side surface352thereof. The fifth lens element350is made of plastic material.

The sixth lens element360with negative refractive power has an object-side surface361being convex in a paraxial region thereof, an image-side surface362being concave in a paraxial region thereof, both the object-side surface361and the image-side surface362being aspheric, and at least one critical point in both an off-axis region of the object-side surface361and an off-axis region of the image-side surface362thereof. The sixth lens element360is made of plastic material.

In the imaging optical lens, each of the first lens element310, the second lens element320, the third lens element330, the fifth lens element350and the sixth lens element360has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive.

The imaging optical lens further includes an aperture stop300disposed at an object side of the first lens element310, a stop301disposed between the second lens element320and the third lens element330, and a filter370disposed between the sixth lens element360and an image surface380. The filter370is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor390is disposed on or near the image surface380of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 5 and TABLE 6 and satisfy the conditions stated in table below.

FIG. 4Ais a schematic view of an imaging apparatus according to the 4th embodiment of the present disclosure.FIG. 4Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 4th embodiment.

InFIG. 4A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor490. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element410a second lens element420, a third lens element430, a fourth lens element440, a fifth lens element450, and a sixth lens element460and no other lens elements are inserted between the first lens element410and the sixth lens element460.

The first lens element410with positive refractive power has an object-side surface411being convex in a paraxial region thereof, an image-side surface412being concave in a paraxial region thereof, and both the object-side surface411and the image-side surface412being aspheric. The first lens element410is made of plastic material.

The second lens element420with negative refractive power has an object-side surface421being convex in a paraxial region thereof, an image-side surface422being concave in a paraxial region thereof, and both the object-side surface421and the image-side surface422being aspheric. The second lens element420is made of plastic material.

The third lens element430with positive 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 both the object-side surface431and the image-side surface432being aspheric. The third lens element430is made of plastic material.

The fourth lens element440with negative refractive power has an object-side surface441being convex in a paraxial region thereof, an image-side surface442being concave in a paraxial region thereof, and both the object-side surface441and the image-side surface442being aspheric. The fourth lens element440is made of plastic material.

The fifth lens element450with positive refractive power has an object-side surface451being convex in a paraxial region thereof, an image-side surface452being concave in a paraxial region thereof, both the object-side surface451and the image-side surface452being aspheric, and at least one critical point in both an off-axis region of the object-side surface451and an off-axis region of the image-side surface452thereof. The fifth lens element450is made of plastic material.

The sixth lens element460with negative refractive power has an object-side surface461being convex in a paraxial region thereof, an image-side surface462being concave in a paraxial region thereof, both the object-side surface461and the image-side surface462being aspheric, and at least one critical point in both an off-axis region of the object-side surface461and an off-axis region of the image-side surface462thereof. The sixth lens element460is made of plastic material.

In the imaging optical lens, each of the first lens element410, the second lens element420, the third lens element430, the fourth lens element440, the fifth lens element450and the sixth lens element460has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element420, the third lens element430, and the fourth lens element440, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop400disposed at an object side of the first lens element410, a stop401disposed between the second lens element420and the third lens element430, and a filter470disposed between the sixth lens element460and an image surface480. The filter470is made of glass material and will not affect a focal length of the imaging optical lens. The image sensor490is disposed on or near the image surface480of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 7 and TABLE 8 and satisfy the conditions stated in table below.

FIG. 5Ais a schematic view of an imaging apparatus according to the 5th embodiment of the present disclosure.FIG. 5Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 5th embodiment.

InFIG. 5A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor590. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element510, a second lens element520, a third lens element530, a fourth lens element540, a fifth lens element550, and a sixth lens element560and no other lens elements are inserted between the first lens element510and the sixth lens element560.

The first lens element510with positive refractive power has an object-side surface511being convex in a paraxial region thereof, an image-side surface512being concave in a paraxial region thereof, and both the object-side surface511and the image-side surface512being aspheric. The first lens element510is made of plastic material.

The second lens element520with negative refractive power has an object-side surface521being convex in a paraxial region thereof, an image-side surface522being concave in a paraxial region thereof, and both the object-side surface521and the image-side surface522being aspheric. The second lens element520is made of plastic material.

The third lens element530with positive refractive power has an object-side surface531being convex in a paraxial region thereof, an image-side surface532being concave in a paraxial region thereof, and both the object-side surface531and the image-side surface532being aspheric. The third lens element530is made of plastic material.

The fourth lens element540with negative refractive power has an object-side surface541being convex in a paraxial region thereof, an image-side surface542being concave in a paraxial region thereof, and both the object-side surface541and the image-side surface542being aspheric. The fourth lens element540is made of plastic material.

The fifth lens element550with positive refractive power has an object-side surface551being convex in a paraxial region thereof, an image-side surface552being concave in a paraxial region thereof, both the object-side surface551and the image-side surface552being aspheric, and at least one critical point in both an off-axis region of the object-side surface551and an off-axis region of the image-side surface552thereof. The fifth lens element550is made of plastic material.

The sixth lens element560with negative refractive power has an object-side surface561being convex in a paraxial region thereof, an image-side surface562being concave in a paraxial region thereof, both the object-side surface561and the image-side surface562being aspheric, and at least one critical point in both an off-axis region of the object-side surface561and an off-axis region of the image-side surface562thereof. The sixth lens element560is made of plastic material.

In the imaging optical lens, each of the first lens element510, the second lens element520, the third lens element530, the fourth lens element540, the fifth lens element550and the sixth lens element560has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element520, the third lens element530, and the fourth lens element540, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop500disposed at an object side of the first lens element510, a stop501disposed between the second lens element520and the third lens element530, and a filter570disposed between the sixth lens element560and an image surface580. The filter570is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor590is disposed on or near the image surface580of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 9 and TABLE 10 and satisfy the conditions stated in table below.

FIG. 6Ais a schematic view of an imaging apparatus according to the 6th embodiment of the present disclosure.FIG. 6Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 6th embodiment.

InFIG. 6A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor690. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element610, a second lens element620, a third lens element630, a fourth lens element640, a fifth lens element650, and a sixth lens element660and no other lens elements are inserted between the first lens element610and the sixth lens element660.

The first lens element610with positive refractive power has an object-side surface611being convex in a paraxial region thereof, an image-side surface612being concave in a paraxial region thereof, and both the object-side surface611and the image-side surface612being aspheric. The first lens element610is made of glass material.

The second lens element620with negative refractive power has an object-side surface621being concave in a paraxial region thereof, an image-side surface622being concave in a paraxial region thereof, and both the object-side surface621and the image-side surface622being aspheric. The second lens element620is made of plastic material.

The third lens element630with positive refractive power has an object-side surface631being convex in a paraxial region thereof, an image-side surface632being concave in a paraxial region thereof, and both the object-side surface631and the image-side surface632being aspheric. The third lens element630is made of plastic material.

The fourth lens element640with positive refractive power has an object-side surface641being convex in a paraxial region thereof, an image-side surface642being concave in a paraxial region thereof, and both the object-side surface641and the image-side surface642being aspheric. The fourth lens element640is made of plastic material.

The fifth lens element650with positive refractive power has an object-side surface651being convex in a paraxial region thereof, an image-side surface652being concave in a paraxial region thereof, both the object-side surface651and the image-side surface652being aspheric, and at least one critical point in both an off-axis region of the object-side surface651and an off-axis region of the image-side surface652thereof. The fifth lens element650is made of plastic material.

The sixth lens element660with negative refractive power has an object-side surface661being convex in a paraxial region thereof, an image-side surface662being concave in a paraxial region thereof, both the object-side surface661and the image-side surface662being aspheric, and at least one critical point in both an off-axis region of the object-side surface661and an off-axis region of the image-side surface662thereof. The sixth lens element660is made of plastic material.

In the imaging optical lens, each of the first lens element610, the third lens element630, the fourth lens element640, the fifth lens element650and the sixth lens element660has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive.

The imaging optical lens further includes an aperture stop600disposed at an object side of the first lens element610, a stop601disposed between the second lens element620and the third lens element630, and a filter670disposed between the sixth lens element660and an image surface680. The filter670is made of glass material and will not affect a focal length of the imaging optical lens. The image sensor690is disposed on or near the image surface680of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 11 and TABLE 12 and satisfy the conditions stated in table below.

FIG. 7Ais a schematic view of an imaging apparatus according to the 7th embodiment of the present disclosure.FIG. 7Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 7th embodiment.

InFIG. 7A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor790. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element710, a second lens element720, a third lens element730, a fourth lens element740, a fifth lens element750, and a sixth lens element760and no other lens elements are inserted between the first lens element710and the sixth lens element760.

The first lens element710with positive refractive power has an object-side surface711being convex in a paraxial region thereof, an image-side surface712being convex in a paraxial region thereof, and both the object-side surface711and the image-side surface712being aspheric. The first lens element710is made of plastic material.

The second lens element720with negative refractive power has an object-side surface721being convex in a paraxial region thereof, an image-side surface722being concave in a paraxial region thereof, and both the object-side surface721and the image-side surface722being aspheric. The second lens element720is made of plastic material.

The third lens element730with positive refractive power has an object-side surface731being convex in a paraxial region thereof, an image-side surface732being convex in a paraxial region thereof, and both the object-side surface731and the image-side surface732being aspheric. The third lens element730is made of plastic material.

The fourth lens element740with negative refractive power has an object-side surface741being concave in a paraxial region thereof, an image-side surface742being concave in a paraxial region thereof, and both the object-side surface741and the image-side surface742being aspheric. The fourth lens element740is made of plastic material.

The fifth lens element750with positive refractive power has an object-side surface751being convex in a paraxial region thereof, an image-side surface752being concave in a paraxial region thereof, both the object-side surface751and the image-side surface752being aspheric, and at least one critical point in both an off-axis region of the object-side surface751and an off-axis region of the image-side surface752thereof. The fifth lens element750is made of plastic material.

The sixth lens element760with negative refractive power has an object-side surface761being convex in a paraxial region thereof, an image-side surface762being concave in a paraxial region thereof, both the object-side surface761and the image-side surface762being aspheric, and at least one critical point in both an off-axis region of the object-side surface761and an off-axis region of the image-side surface762thereof. The sixth lens element760is made of plastic material.

The imaging optical lens further includes an aperture stop700disposed at an object side of the first lens element710, a stop701disposed between the second lens element720and the third lens element730, and a filter770disposed between the sixth lens element760and an image surface780. The filter770is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor790is disposed on or near the image surface780of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 13 and TABLE 14 and satisfy the conditions stated in table below.

FIG. 8Ais a schematic view of an imaging apparatus according to the 8th embodiment of the present disclosure.FIG. 8Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 8th embodiment.

InFIG. 8A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor890. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element810, a second lens element820, a third lens element830, a fourth lens element840, a fifth lens element850, and a sixth lens element860and no other lens elements are inserted between the first lens element810and the sixth lens element860.

The first lens element810with positive refractive power has an object-side surface811being convex in a paraxial region thereof, an image-side surface812being concave in a paraxial region thereof, and both the object-side surface811and the image-side surface812being aspheric. The first lens element810is made of plastic material.

The second lens element820with negative refractive power has an object-side surface821being convex in a paraxial region thereof, an image-side surface822being concave in a paraxial region thereof, and both the object-side surface821and the image-side surface822being aspheric. The second lens element820is made of plastic material.

The third lens element830with positive refractive power has an object-side surface831being convex in a paraxial region thereof, an image-side surface832being concave in a paraxial region thereof, and both the object-side surface831and the image-side surface832being aspheric. The third lens element830is made of plastic material.

The fourth lens element840with positive refractive power has an object-side surface841being concave in a paraxial region thereof, an image-side surface842being convex in a paraxial region thereof, and both the object-side surface841and the image-side surface842being aspheric. The fourth lens element840is made of plastic material.

The fifth lens element850with positive refractive power has an object-side surface851being convex in a paraxial region thereof, an image-side surface852being concave in a paraxial region thereof, both the object-side surface851and the image-side surface852being aspheric, and at least one critical point in both an off-axis region of the object-side surface851and an off-axis region of the image-side surface852thereof. The fifth lens element850is made of plastic material.

The sixth lens element860with negative refractive power has an object-side surface861being convex in a paraxial region thereof, an image-side surface862being concave in a paraxial region thereof, both the object-side surface861and the image-side surface862being aspheric, and at least one critical point in both an off-axis region of the object-side surface861and an off-axis region of the image-side surface862thereof. The sixth lens element860is made of plastic material.

In the imaging optical lens, each of the first lens element810, the second lens element820, the third lens element830, the fifth lens element850and the sixth lens element860has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element820, the third lens element830, and the fourth lens element840, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop800disposed at an object side of the first lens element810, a stop801disposed between the second lens element820and the third lens element830, and a filter870disposed between the sixth lens element860and an image surface880. The filter870is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor890is disposed on or near the image surface880of the imaging optical lens.

Moreover, these parameters can be calculated from TABLE 15 and TABLE 16 and satisfy the conditions stated in table below.

FIG. 9Ais a schematic view of an imaging apparatus according to the 9th embodiment of the present disclosure.FIG. 9Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 9th embodiment.

InFIG. 9A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor990. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element910, a second lens element920, a third lens element930, a fourth lens element940, a fifth lens element950, and a sixth lens element960and no other lens elements are inserted between the first lens element910and the sixth lens element960.

The first lens element910with positive refractive power has an object-side surface911being convex in a paraxial region thereof, an image-side surface912being concave in a paraxial region thereof, and both the object-side surface911and the image-side surface912being aspheric. The first lens element910is made of plastic material.

The second lens element920with negative refractive power has an object-side surface921being convex in a paraxial region thereof, an image-side surface922being concave in a paraxial region thereof, and both the object-side surface921and the image-side surface922being aspheric. The second lens element920is made of plastic material.

The third lens element930with negative refractive power has an object-side surface931being convex in a paraxial region thereof, an image-side surface932being concave in a paraxial region thereof, and both the object-side surface931and the image-side surface932being aspheric. The third lens element930is made of plastic material.

The fourth lens element940with positive refractive power has an object-side surface941being convex in a paraxial region thereof, an image-side surface942being concave in a paraxial region thereof, and both the object-side surface941and the image-side surface942being aspheric. The fourth lens element940is made of plastic material.

The fifth lens element950with positive refractive power has an object-side surface951being convex in a paraxial region thereof, an image-side surface952being concave in a paraxial region thereof, both the object-side surface951and the image-side surface952being aspheric, and at least one critical point in both an off-axis region of the object-side surface951and an off-axis region of the image-side surface952thereof. The fifth lens element950is made of plastic material.

The sixth lens element960with negative refractive power has an object-side surface961being convex in a paraxial region thereof, an image-side surface962being concave in a paraxial region thereof, both the object-side surface961and the image-side surface962being aspheric, and at least one critical point in both an off-axis region of the object-side surface961and an off-axis region of the image-side surface962thereof. The sixth lens element960is made of plastic material.

In the imaging optical lens, each of the first lens element910, the second lens element920, the third lens element930, the fourth lens element940, the fifth lens element950and the sixth lens element960has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element920, the third lens element930, and the fourth lens element940, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop900disposed at an object side of the first lens element910, a stop901disposed between the second lens element920and the third lens element930, and a filter970disposed between the sixth lens element960and an image surface980. The filter970is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor990is disposed on or near the image surface980of the imaging optical lens.

The detailed optical data of the 9th embodiment are shown in TABLE 17, and the aspheric surface data are shown in TABLE 18.

Moreover, these parameters can be calculated from TABLE 17 and TABLE 18 and satisfy the conditions stated in table below.

FIG. 10Ais a schematic view of an imaging apparatus according to the 10th embodiment of the present disclosure.FIG. 10Bshows, in order from left to right, longitudinal spherical aberration curves, astigmatic field curves and a distortion curve of the imaging apparatus according to the 10th embodiment.

InFIG. 10A, the imaging apparatus includes an imaging optical lens (not otherwise herein labeled) of the present disclosure and an image sensor1090. The imaging optical lens includes six lens elements, the six lens elements being, in order from an object side to an image side, a first lens element1010, a second lens element1020, a third lens element1030, a fourth lens element1040, a fifth lens element1050, and a sixth lens element1060and no other lens elements are inserted between the first lens element1010and the sixth lens element1060.

The first lens element1010with positive refractive power has an object-side surface1011being convex in a paraxial region thereof, an image-side surface1012being concave in a paraxial region thereof, and both the object-side surface1011and the image-side surface1012being aspheric. The first lens element1010is made of plastic material.

The second lens element1020with negative refractive power has an object-side surface1021being convex in a paraxial region thereof, an image-side surface1022being concave in a paraxial region thereof, and both the object-side surface1021and the image-side surface1022being aspheric. The second lens element1020is made of plastic material.

The third lens element1030with positive refractive power has an object-side surface1031being convex in a paraxial region thereof, an image-side surface1032being concave in a paraxial region thereof, and both the object-side surface1031and the image-side surface1032being aspheric. The third lens element1030is made of plastic material.

The fourth lens element1040with negative refractive power has an object-side surface1041being convex in a paraxial region thereof, an image-side surface1042being concave in a paraxial region thereof, and both the object-side surface1041and the image-side surface1042being aspheric. The fourth lens element1040is made of plastic material.

The fifth lens element1050with positive refractive power has an object-side surface1051being convex in a paraxial region thereof, an image-side surface1052being concave in a paraxial region thereof, both the object-side surface1051and the image-side surface1052being aspheric, and at least one critical point in both an off-axis region of the object-side surface1051and an off-axis region of the image-side surface1052thereof. The fifth lens element1050is made of plastic material.

The sixth lens element1060with negative refractive power has an object-side surface1061being convex in a paraxial region thereof, an image-side surface1062being concave in a paraxial region thereof, both the object-side surface1061and the image-side surface1062being aspheric, and at least one critical point in both an off-axis region of the object-side surface1061and an off-axis region of the image-side surface1062thereof. The sixth lens element1060is made of plastic material.

In the imaging optical lens, each of the first lens element1010, the second lens element1020, the third lens element1030, the fourth lens element1040, the fifth lens element1050and the sixth lens element1060has both a curvature radius of the object-side surface and a curvature radius of the image-side surface thereof being positive. Three consecutive lens elements, the second lens element1020, the third lens element1030, and the fourth lens element1040, have Abbe numbers lower than 48.

The imaging optical lens further includes an aperture stop1000disposed at an object side of the first lens element1010, a stop1001disposed between the second lens element1020and the third lens element1030, and a filter1070disposed between the sixth lens element1060and an image surface1080. The filter1070is made of glass material and will not affect the focal length of the imaging optical lens. The image sensor1090is disposed on or near the image surface1080of the imaging optical lens.

The detailed optical data of the 10th embodiment are shown in TABLE 19, and the aspheric surface data are shown in TABLE 20.

Moreover, these parameters can be calculated from TABLE 19 and TABLE 20 and satisfy the conditions stated in table below.

FIG. 12is a 3-dimensional schematic view of an imaging apparatus10according to the 11th embodiment of the present disclosure. In the present embodiment, the imaging apparatus10is a camera module. The imaging apparatus10includes a lens unit11, a driving device12, and an image sensor13. The lens unit11includes the imaging optical lens of the 1st embodiment described above and a lens barrel (not otherwise herein labeled) for carrying the imaging optical lens. The imaging apparatus10retrieves light and generates an image by using the lens unit11, using the driving device12to adjust the focus to photograph on the image sensor13and outputs the image data thereafter.

The driving device12may be an auto-focus model that can be driven by a voice coil motor (VCM), a micro electro-mechanical system (MEMS), a piezoelectric system, shape memory metal or other driving systems. The driving device12allows the lens unit11to obtain a better imaging position, providing a clear image wherever an imaged object30(Please refer toFIG. 13B) being positioned with different object distances.

The imaging apparatus10may be configured to equip the image sensor13(e.g., CMOS, CCD) with high sensitivity and low noise on the image surface of the imaging optical lens to truly provide the satisfactory image quality obtained from the imaging optical lens.

In addition, the imaging apparatus10may further include an image stabilizer14, which may be a dynamic sensing element such as accelerometer, a gyroscope or a Hall Effect sensor. The image stabilizer14in the 11th embodiment is a gyroscope but not limited. By adjusting the imaging optical lens in different axial directions to provide a compensation for image blurs due to motion during exposures, the image quality under dynamic and low-light circumstances can be further improved and enhanced image compensation functions such as optical image stabilization (OIS) or electronic image stabilization (EIS) can also be provided.

Please refer toFIG. 13AandFIG. 13B.FIG. 13Ais a 3-dimensional schematic view of an electronic device20according to the 12th embodiment of the present disclosure.FIG. 13Bis a schematic view of the electronic device20shown in theFIG. 13A. In the present embodiment, the electronic device20is a smart phone. The electronic device20includes the imaging apparatus10of the 11th embodiment, a flash module21, a focus assist module22, an image signal processor23, a user interface24, and an image software processor25(Please refer toFIG. 13B).

When a user utilizes the user interface24to capture images of the object30(Please refer toFIG. 13B), the electronic device20retrieves the light and captures an image via the imaging apparatuses10, triggering the flash module21to compensate insufficient light level, and focuses instantly according to the distance information of the object30provided by the focus assist module22. The images are further optimized by the image signal processor23to further enhance the image quality generated by the imaging optical lens. The focus assist module22may adopt an infrared ray or laser focus assist system to achieve quick focusing. The user interface24may use a touch screen or a physical shooting button cooperated with various functions of the image software processor25to perform image capturing and image processing.

The imaging apparatus10of the present disclosure is not limited to be applied to the smart phone. The imaging apparatus10may be used in a system of moving focus and features in both excellent aberration correction and satisfactory image quality. For example, the imaging apparatus10may be applied to a variety of applications such as car electronics, drones, smart electronic products, tablet computers, wearable devices, medical devices, precision instruments, surveillance cameras, portable video recorders, identification systems, multi-lens devices, somatosensory detections, virtual realities, motion devices, home intelligent auxiliary systems and other electronic devices. The aforementioned electronic apparatus is merely exemplary of practical use of the present disclosure and does not limit the scope of application of the imaging apparatus of the present disclosure.

The aforementioned exemplary figures of different electronic devices are only exemplary for showing the imaging apparatus of the present disclosure installed in an electronic device, and the present disclosure is not limited thereto. Preferably, the electronic device can further include a control unit, a display unit, a storage unit, a random access memory unit (RAM) or a combination thereof.