IMAGING OPTICAL LENS SYSTEM, IMAGE CAPTURING UNIT AND ELECTRONIC DEVICE

An imaging optical lens system includes eleven lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, an eighth lens element, a ninth lens element, a tenth lens element and an eleventh lens element. There is an air gap in a paraxial region between each of all adjacent lens elements of the imaging optical lens system. At least one of an object-side surface and an image-side surface of each of at least two lens elements located between an aperture stop and an image surface of the imaging optical lens system is concave in a paraxial region thereof and has at least one convex critical point in an off-axis region thereof.

BACKGROUND

Technical Field

The present disclosure relates to an imaging optical lens system, an image capturing unit and an electronic device, more particularly to an imaging optical lens system and an image capturing unit applicable to an electronic device.

Description of Related Art

With the development of semiconductor manufacturing technology, the performance of image sensors has improved, and the pixel size thereof has been scaled down. Therefore, featuring high image quality becomes one of the indispensable features of an optical system nowadays.

Furthermore, due to the rapid changes in technology, electronic devices equipped with optical systems are trending towards multi-functionality for various applications, and therefore the functionality requirements for the optical systems have been increasing. However, it is difficult for a conventional optical system to obtain a balance among the requirements such as high image quality, low sensitivity, a proper aperture size, miniaturization and a desirable field of view.

SUMMARY

According to one aspect of the present disclosure, an imaging optical lens system includes eleven lens elements. The eleven lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, an eighth lens element, a ninth lens element, a tenth lens element and an eleventh lens element. There is an air gap in a paraxial region between each of all adjacent lens elements of the imaging optical lens system. The imaging optical lens system further includes an aperture stop, and at least one of an object-side surface and an image-side surface of each of at least two lens elements located between the aperture stop and an image surface of the imaging optical lens system is concave in a paraxial region thereof and has at least one convex critical point in an off-axis region thereof.

According to another aspect of the present disclosure, an imaging optical lens system includes eleven lens elements. The eleven lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, an eighth lens element, a ninth lens element, a tenth lens element and an eleventh lens element. The first lens element has positive refractive power. At least one of an object-side surface of the eighth lens element and an image-side surface of the eighth lens element is aspheric. The eleventh lens element has an object-side surface having at least one inflection point in an off-axis region thereof, and the eleventh lens element has an image-side surface being concave in a paraxial region thereof and having at least one convex critical point in an off-axis region thereof.

According to another aspect of the present disclosure, an image capturing unit includes one of the aforementioned imaging optical lens systems and an image sensor, wherein the image sensor is disposed on the image surface of the imaging optical lens system.

According to another aspect of the present disclosure, an electronic device includes the aforementioned image capturing unit.

DETAILED DESCRIPTION

An imaging optical lens system includes eleven lens elements. The eleven lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, an eighth lens element, a ninth lens element, a tenth lens element and an eleventh lens element.

There can be an air gap in a paraxial region between each of all adjacent lens elements of the imaging optical lens system. Therefore, it is favorable for reducing the assembling difficulty of the imaging optical lens system so as to increase the assembly yield rate. In detail, each of the eleven lens elements can be a single and non-cemented lens element. The manufacturing process of cemented lenses is more complex than the non-cemented lenses, particularly when an image-side surface of one lens element and an object-side surface of the following lens element need to have accurate curvatures to ensure both lenses being properly cemented. In addition, during the cementing process, those two lens elements might not be well cemented due to misalignment, which is not favorable for the image quality. Therefore, having an air gap in a paraxial region between each of all adjacent lens elements of the imaging optical lens system in the present disclosure is favorable for avoiding the problems of the cemented lens elements so as to increase flexibility in designing the surface shapes of lens elements, thereby reducing the size of the imaging optical lens system and correcting aberrations.

The first lens element can have positive refractive power. Therefore, it is favorable for providing significant light convergence so as to effectively reduce the total track length of the imaging optical lens system for the requirement of compactness.

At least one of an object-side surface of the eighth lens element and an image-side surface of the eighth lens element can be aspheric. Therefore, it is favorable for effectively correcting aberrations and controlling the thickness of the eighth lens element so as to prevent occupying too much space.

The eleventh lens element can have an object-side surface having at least one inflection point in an off-axis region thereof. Therefore, it is favorable for correcting off-axis aberrations and reducing the size of imaging optical lens system. Please refer toFIG. 25, which shows a schematic view of an inflection point P of the object-side surface197of the eleventh lens element196according to the 1st embodiment of the present disclosure. The inflection point on the object-side surface of the eleventh lens element inFIG. 25is only exemplary. The other lens elements may also have one or more inflection points.

The imaging optical lens system can further include an aperture stop, and the aperture stop can be located between an imaged object and the fourth lens element. At least one of an object-side surface and an image-side surface of each of at least two lens elements located between the aperture stop and an image surface of the imaging optical lens system can be concave in a paraxial region thereof and can have at least one convex critical point in an off-axis region thereof. Therefore, it is favorable for correcting aberrations of the periphery image and increasing relative illuminance. Moreover, at least one of an object-side surface and an image-side surface of each of at least three lens elements of the imaging optical lens system can be concave in a paraxial region thereof and can have at least one convex critical point in an off-axis region thereof. Moreover, each of at least two of an image-side surface of the ninth lens element, an image-side surface of the tenth lens element and an image-side surface of the eleventh lens element can be concave in a paraxial region thereof and can have at least one convex critical point in an off-axis region thereof. Moreover, the image-side surface of the eleventh lens element can be concave in a paraxial region thereof and can have at least one convex critical point in an off-axis region thereof. Please refer toFIG. 25, which shows a schematic view of several convex critical points C1of the image-side surface142of the fourth lens element140, the object-side surface151of the fifth lens element150, the image-side surface152of the fifth lens element150, the image-side surface182of the eighth lens element180, the image-side surface192of the ninth lens element190, the image-side surface195of the tenth lens element193and the image-side surface198of the eleventh lens element196according to the 1st embodiment of the present disclosure. The convex critical points on the image-side surface of the fourth lens element, the object-side surface of the fifth lens element, the image-side surface of the fifth lens element, the image-side surface of the eighth lens element, the image-side surface of the ninth lens element, the image-side surface of the tenth lens element and the image-side surface of the eleventh lens element inFIG. 25are only exemplary. The other lens elements may also have one or more convex critical points.

Each of the at least two lens elements located between the aperture stop and the image surface of the imaging optical lens system can have negative refractive power. Therefore, it is favorable for balancing overall refractive power of the imaging optical lens system and correcting various aberrations.

At least one of an object-side surface and an image-side surface of each of at least two lens elements of the imaging optical lens system can be convex in a paraxial region thereof and can have at least one concave critical point in an off-axis region thereof. Therefore, it is favorable for enhancing aberration corrections of the periphery image and increasing relative illuminance by coordinating with the lens surface that is concave in the paraxial region thereof and has at least one convex critical point in the off-axis region thereof; and it is also favorable for forming a proper shape of the lens surface. Moreover, the tenth lens element can have an object-side surface being convex in a paraxial region thereof and having at least one concave critical point in an off-axis region thereof. Please refer toFIG. 25, which shows a schematic view of several concave critical points C2of the object-side surface141of the fourth lens element140, the image-side surface142of the fourth lens element140, the object-side surface151of the fifth lens element150, the object-side surface181of the eighth lens element180, the object-side surface191of the ninth lens element190and the object-side surface194of the tenth lens element193according to the 1st embodiment of the present disclosure. The concave critical points on the object-side surface of the fourth lens element, the image-side surface of the fourth lens element, the object-side surface of the fifth lens element, the object-side surface of the eighth lens element, the object-side surface of the ninth lens element and the object-side surface of the tenth lens element inFIG. 25are only exemplary. The other lens elements may also have one or more concave critical points.

When a vertical distance between a critical point on the image-side surface of the tenth lens element and an optical axis is Yc10R2, and a vertical distance between a critical point on the image-side surface of the eleventh lens element and the optical axis is Yc11R2, the following condition can be satisfied: 0.5<Yc11R2/Yc10R2<2.0. Therefore, it is favorable for correcting aberrations of the periphery image and increasing relative illuminance. Please refer toFIG. 25, which shows a schematic view of Yc10R2, Yc11R2 and several convex critical points C1on the image-side surface195of the tenth lens element193and the image-side surface198of the eleventh lens element196according to the 1st embodiment of the present disclosure.

When the vertical distance between the critical point on the image-side surface of the eleventh lens element and the optical axis is Yc11R2, and a focal length of the imaging optical lens system is f, the following condition can be satisfied: Yc11R2/f<0.50. Therefore, it is favorable for further correcting aberrations of the periphery image at the image side of the imaging optical lens system and increasing relative illuminance.

The aforementioned air gaps between respective pairs of adjacent lens elements of the imaging optical lens system include a maximum spacing distance; that is, at least one of the air gaps, with the maximum spacing distance, is larger than the rest of air gaps. A lens surface located at an object side of the maximum spacing distance can be concave in a paraxial region thereof. Therefore, it is favorable for utilizing air in the maximum spacing distance as the transmission medium for light convergence and aberration corrections of the periphery image. Moreover, when the focal length of the imaging optical lens system is f, and a curvature radius of a lens surface located at an image side of the maximum spacing distance is Ri, the following condition can be satisfied: f/|Ri|<0.80. Therefore, it is favorable for adjusting the ratio of the focal length to the curvature radius of the refractive surface at the image side of the maximum spacing distance so as to enable light converging in different fields of view, thereby optimizing the focusing on the image surface.

According to the present disclosure, at least six lens elements of the imaging optical lens system can be made of plastic material. Therefore, it is favorable for increasing mass production capacity and reducing the weight of the imaging optical lens system.

When a maximum image height of the imaging optical lens system (which can be half of a diagonal length of an effective photosensitive area of the image sensor) is ImgH, and an axial distance between the image-side surface of the eleventh lens element and the image surface is BL, the following condition can be satisfied: 2.0<ImgH/BL<12.0. Therefore, it is favorable for obtaining a proper balance between miniaturization and module manufacturability of the imaging optical lens system. Moreover, the following condition can also be satisfied: 4.0<ImgH/BL<10.0.

When a total number of lens elements having an Abbe number smaller than 24 in the imaging optical lens system is V24, the following condition can be satisfied: 2≤V24. Therefore, it is favorable for enhancing chromatic aberration corrections. Moreover, the following condition can also be satisfied: 3≤V24. Moreover, when a total number of lens elements having an Abbe number smaller than 20 in the imaging optical lens system is V20, the following condition can be satisfied: 2 V20.

When a minimum value among Abbe numbers of all lens elements of the imaging optical lens system is Vmin, the following condition can be satisfied: Vmin<20. Therefore, it is favorable for enhancing chromatic aberration corrections.

When a maximum value among axial distances between each of all adjacent lens elements of the imaging optical lens system is ATmax, and a minimum value among axial distances between each of all adjacent lens elements of the imaging optical lens system is ATmin, the following condition can be satisfied: 2.0<ATmax/ATmin<120. Therefore, it is favorable for enhancing efficiency in space utilization of lens elements so as to prevent poor space utilization due to an overly dense or sparse arrangement of lens elements.

When an axial distance between an object-side surface of the first lens element and the image surface is TL, and an entrance pupil diameter of the imaging optical lens system is EPD, the following condition can be satisfied: 0.5<TL/EPD<3.0. Therefore, it is favorable for further featuring a large aperture stop so as to provide a sufficient amount of incident light. Moreover, the following condition can also be satisfied: 0.75<TL/EPD<2.75.

When an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, an Abbe number of the seventh lens element is V7, an Abbe number of the eighth lens element is V8, an Abbe number of the ninth lens element is V9, an Abbe number of the tenth lens element is V10, an Abbe number of the eleventh lens element is V11, an Abbe number of the i-th lens element is Vi, a refractive index of the first lens element is N1, a refractive index of the second lens element is N2, a refractive index of the third lens element is N3, a refractive index of the fourth lens element is N4, a refractive index of the fifth lens element is N5, a refractive index of the sixth lens element is N6, a refractive index of the seventh lens element is N7, a refractive index of the eighth lens element is N8, a refractive index of the ninth lens element is N9, a refractive index of the tenth lens element is N10, a refractive index of the eleventh lens element is N11, and a refractive index of the i-th lens element is Ni, at least one lens element of the imaging optical lens system can satisfy the following condition: 6.0<Vi/Ni<12.0, wherein i=1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11. Therefore, it is favorable for enhancing chromatic aberration corrections. Moreover, at least one lens element of the imaging optical lens system can also satisfy the following condition: 8.0<Vi/Ni<12.0, wherein i=1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11. Moreover, at least one lens element of the imaging optical lens system can also satisfy the following condition: 6.0<Vi/Ni<11.2, wherein i=1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11. Moreover, at least one lens element of the imaging optical lens system can also satisfy the following condition: 7.5<Vi/Ni<10, wherein i=1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, and the maximum image height of the imaging optical lens system is ImgH, the following condition can be satisfied: TL/ImgH<2.50. Therefore, it is favorable for miniaturizing the imaging optical lens system. Moreover, the following condition can also be satisfied: TL/ImgH<1.80. Moreover, the following condition can also be satisfied: TL/ImgH<1.60.

When the focal length of the imaging optical lens system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and a focal length of the third lens element is f3, the following condition can be satisfied: 0.75<|f/f1|+|f/f2|+|f/f3|<2.50. Therefore, it is favorable for effectively ensuring sufficient positive refractive power at the object side of the imaging optical lens system so as to further reduce the total track length.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, and a maximum effective radius of the image-side surface of the eleventh lens element is Y11R2, the following condition can be satisfied: TLN11R2<3.50. Therefore, it is favorable for controlling the size of the imaging optical lens system so as to fit in a high-resolution miniaturized image capturing unit. Please refer toFIG. 25, which shows a schematic view of Y11R2 according to the 1st embodiment of the present disclosure.

When an axial distance between the object-side surface of the first lens element and the image-side surface of the eleventh lens element is Td, and an axial distance between an object-side surface of the fifth lens element and the image-side surface of the eighth lens element is Dr9r16, the following condition can be satisfied: 3.0<Td/Dr9r16<6.0. Therefore, it is favorable for enhancing efficiency in space utilization of lens elements at the middle portion of the imaging optical lens system so as to prevent poor space utilization due to an overly dense or sparse arrangement of lens elements.

When the axial distance between the object-side surface of the first lens element and the image-side surface of the eleventh lens element is Td, and a sum of central thicknesses of all lens elements of the imaging optical lens system is ΣCT, the following condition can be satisfied: Td/ΣCT<1.75. Therefore, it is favorable for balancing the thicknesses and space arrangement among lens elements so as to optimize the space utilization of the imaging optical lens system.

When the focal length of the imaging optical lens system is f, and a focal length of the i-th lens element is fi, at least two lens elements of the imaging optical lens system can satisfy the following condition: |f/f1|<0.20, wherein i=1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11. Therefore, it is favorable for preventing excessive image corrections or generation of ghost images due to overly large differences of refractive power among lens elements.

When an axial distance between the aperture stop and the image-side surface of the eleventh lens element is Sd, and the axial distance between the object-side surface of the first lens element and the image-side surface of the eleventh lens element is Td, the following condition can be satisfied: 0.60<Sd/Td<1.20. Therefore, it is favorable for adjusting the position of the aperture stop, thereby featuring a large aperture stop, a large field of view and miniaturization. Moreover, the following condition can also be satisfied: 0.75<Sd/Td<1.0.

When an f-number of the imaging optical lens system is Fno, the following condition can be satisfied: 1.0<Fno<2.20. Therefore, it is favorable for further featuring a large aperture stop so as to provide a sufficient amount of incident light. Moreover, the following condition can also be satisfied: 1.0<Fno<2.10. Moreover, the following condition can also be satisfied: 1.20<Fno<2.10.

When a maximum effective radius of the object-side surface of the first lens element is Y1R1, and the maximum effective radius of the image-side surface of the eleventh lens element is Y11R2, the following condition can be satisfied: Y1R1N11R2<0.80. Therefore, it is favorable for effectively controlling optical path ranges at the object side and the image side of the imaging optical lens system so as to enhance space utilization while providing high-resolution image quality. Moreover, the following condition can also be satisfied: Y1R1/Y11R2<0.60. Please refer toFIG. 25, which shows a schematic view of Y1R1 and Y11R2 according to the 1st embodiment of the present disclosure.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, the following condition can be satisfied: 5.0 [mm]<TL<16.0 [mm]. Therefore, it is favorable for controlling the total track length so as to expand product application range and meet market requirements nowadays.

When half of a maximum field of view of the imaging optical lens system is HFOV, the following condition can be satisfied: 35.0 [deg.]<HFOV<100.0 [deg.]. Therefore, it is favorable for having sufficiently large fields of view of the imaging optical lens system so as to meet various usage requirements.

When the maximum image height of the imaging optical lens system is ImgH, the following condition can be satisfied: 5.50 [mm]<ImgH<10.0 [mm]. Therefore, it is favorable for ensuring a sufficient light receiving area and image brightness while balancing with specification requirements.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, and the focal length of the imaging optical lens system is f, the following condition can be satisfied: 0.75<TL/f<1.50. Therefore, it is favorable for effectively adjusting the total track length of the imaging optical lens system so as to satisfy requirements of various applications.

When a maximum value among Abbe numbers of all lens elements of the imaging optical lens system is Vmax, the following condition can be satisfied: 50.0<Vmax<60.0. Therefore, it is favorable for increasing flexibility in arranging lens materials.

When a curvature radius of the image-side surface of the eleventh lens element is R22, and the maximum image height of the imaging optical lens system is ImgH, the following condition can be satisfied: R22/ImgH<1.20. Therefore, it is favorable for further reducing the back focal length, such that the imaging optical lens system can properly utilize the limited space.

When the focal length of the imaging optical lens system is f, a focal length of the tenth lens element is f10, and a focal length of the eleventh lens element is f11, the following condition can be satisfied: 1.20<|f/f10|+|f/f11|<4.0. Therefore, it is favorable for correcting aberrations of the periphery image and reducing the back focal length by lens elements at the image side of the imaging optical lens system.

When a maximum value among central thicknesses of all lens elements of the imaging optical lens system is CTmax, and a minimum value among central thicknesses of all lens elements of the imaging optical lens system is CTmin, the following condition can be satisfied: 1.25<CTmax/CTmin<6.0. Therefore, it is favorable for enhancing manufacturability of lens elements so as to prevent breakage due to an overly small thickness or being poorly molded due to an overly large thickness. Moreover, the following condition can also be satisfied: 1.5<CTmax/CTmin<5.0.

According to the present disclosure, the aforementioned features and conditions can be utilized in numerous combinations so as to achieve corresponding effects.

According to the present disclosure, the lens elements of the imaging optical lens system can be made of either glass or plastic material. When the lens elements are made of glass material, the refractive power distribution of the imaging optical lens system may be more flexible, and the influence on imaging caused by external environment temperature change may be reduced. The glass lens element can either be made by grinding or molding. When the lens elements are made of plastic material, the manufacturing costs can be effectively reduced. Furthermore, surfaces of each lens element can be arranged to be spherical or aspheric. Spherical lens elements are simple in manufacture. Aspheric lens element design allows more control variables for eliminating aberrations thereof and reducing the required number of lens elements, and the total track length of the imaging optical lens system can therefore be effectively shortened. Additionally, the aspheric surfaces may be formed by plastic injection molding or glass molding.

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

According to the present disclosure, one or more of the lens elements' material may optionally include an additive which generates light absorption and interference effects and alters the lens elements' transmittance in a specific range of wavelength for a reduction in unwanted stray light or color deviation. For example, the additive may optionally filter out light in the wavelength range of 600 nm to 800 nm to reduce excessive red light and/or near infrared light; or may optionally filter out light in the wavelength range of 350 nm to 450 nm to reduce excessive blue light and/or near ultraviolet light from interfering the final image. The additive may be homogeneously mixed with a plastic material to be used in manufacturing a mixed-material lens element by injection molding. In addition, the additive may also be coated on the lens surfaces so as to provide abovementioned effects.

According to 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 the optical axis, and the off-axis region refers to the region of the surface away from the paraxial region. Particularly, unless otherwise stated, when the lens element has a convex surface, it indicates that the surface is convex in the paraxial region thereof; when the lens element has a concave surface, it indicates that the surface is concave in the paraxial region thereof. Moreover, when a region of refractive power or focus of a lens element is not defined, it indicates that the region of refractive power or focus of the lens element is in the paraxial region thereof.

According to the present disclosure, an inflection point is a point on the surface of the lens element at which the surface changes from concave to convex, or vice versa. A critical point is a non-axial point of the lens surface where its tangent is perpendicular to the optical axis.

According to the present disclosure, the image surface of the imaging optical lens system, based on the corresponding image sensor, can be flat or curved, especially a curved surface being concave facing towards the object side of the imaging optical lens system.

According to the present disclosure, an image correction unit, such as a field flattener, can be optionally disposed between the lens element closest to the image side of the imaging optical lens system along the optical path and the image surface for correction of aberrations such as field curvature. The optical properties of the image correction unit, such as curvature, thickness, index of refraction, position and surface shape (convex or concave surface with spherical, aspheric, diffractive or Fresnel types), can be adjusted according to the design of the image capturing unit. In general, a preferable image correction unit is, for example, a thin transparent element having a concave object-side surface and a planar image-side surface, and the thin transparent element is disposed near the image surface.

According to the present disclosure, at least one light-folding element, such as a prism or a mirror, can be optionally disposed between an imaged object and the image surface on the imaging optical path, such that the imaging optical lens system can be more flexible in space arrangement, and therefore the dimensions of an electronic device is not restricted by the total track length of the imaging optical lens system. Specifically, please refer toFIG. 26andFIG. 27.FIG. 26shows a schematic view of a configuration of a light-folding element in an imaging optical lens system according to one embodiment of the present disclosure, andFIG. 27shows a schematic view of another configuration of a light-folding element in an imaging optical lens system according to one embodiment of the present disclosure. InFIG. 26andFIG. 27, the imaging optical lens system can have, in order from an imaged object (not shown in the figures) to an image surface IM along an optical path, a first optical axis OA1, a light-folding element LF and a second optical axis OA2. The light-folding element LF can be disposed between the imaged object and a lens group LG of the imaging optical lens system as shown inFIG. 26or disposed between a lens group LG of the imaging optical lens system and the image surface IM as shown inFIG. 27. Furthermore, please refer toFIG. 28, which shows a schematic view of a configuration of two light-folding elements in an imaging optical lens system according to one embodiment of the present disclosure. InFIG. 28, the imaging optical lens system can have, in order from an imaged object (not shown in the figure) to an image surface IM along an optical path, a first optical axis OA1, a first light-folding element LF1, a second optical axis OA2, a second light-folding element LF2and a third optical axis OA3. The first light-folding element LF1is disposed between the imaged object and a lens group LG of the imaging optical lens system, the second light-folding element LF2is disposed between the lens group LG of the imaging optical lens system and the image surface IM, and the travelling direction of light on the first optical axis OA1can be the same direction as the travelling direction of light on the third optical axis OA3as shown inFIG. 28. The imaging optical lens system can be optionally provided with three or more light-folding elements, and the present disclosure is not limited to the type, amount and position of the light-folding elements of the embodiments disclosed in the aforementioned figures.

According to the present disclosure, the imaging optical lens system 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 set for eliminating the stray light and thereby improving image quality thereof.

According to 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 imaging optical lens system and the image surface to produce a telecentric effect, and thereby improves the image-sensing efficiency of an image sensor (for example, CCD or CMOS). A middle stop disposed between the first lens element and the image surface is favorable for enlarging the viewing angle of the imaging optical lens system and thereby provides a wider field of view for the same.

According to the present disclosure, the imaging optical lens system can include an aperture control unit. The aperture control unit may be a mechanical component or a light modulator, which can control the size and shape of the aperture through electricity or electrical signals. The mechanical component can include a movable member, such as a blade assembly or a light shielding sheet. The light modulator can include a shielding element, such as a filter, an electrochromic material or a liquid-crystal layer. The aperture control unit controls the amount of incident light or exposure time to enhance the capability of image quality adjustment. In addition, the aperture control unit can be the aperture stop of the present disclosure, which changes the f-number to obtain different image effects, such as the depth of field or lens speed.

FIG. 1is a schematic view of an image capturing unit according to the 1st embodiment of the present disclosure.FIG. 2shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 1st embodiment. InFIG. 1, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS1. The imaging optical lens system includes, in order from an object side to an image side along an optical path, an aperture stop100, a first lens element110, a second lens element120, a third lens element130, a fourth lens element140, a fifth lens element150, a sixth lens element160, a seventh lens element170, a stop101, an eighth lens element180, a ninth lens element190, a tenth lens element193, an eleventh lens element196, an IR-cut filter FT1and an image surface IM1. The imaging optical lens system includes eleven lens elements (110,120,130,140,150,160,170,180,190,193and196) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements. In this embodiment, an air gap in a paraxial region between two adjacent lens elements means the two adjacent lens elements are two non-cemented lens elements in paraxial regions thereof.

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. The first lens element110is made of plastic material and has the object-side surface111and the image-side surface112being both aspheric.

The second lens element120with positive refractive power has an object-side surface121being convex in a paraxial region thereof and an image-side surface122being concave in a paraxial region thereof. The second lens element120is made of plastic material and has the object-side surface121and the image-side surface122being both 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. The third lens element130is made of plastic material and has the object-side surface131and the image-side surface132being both aspheric.

The fourth lens element140with negative refractive power has an object-side surface141being convex in a paraxial region thereof and an image-side surface142being concave in a paraxial region thereof. The fourth lens element140is made of plastic material and has the object-side surface141and the image-side surface142being both aspheric. The object-side surface141of the fourth lens element140has at least one concave critical point in an off-axis region thereof. The image-side surface142of the fourth lens element140has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The fifth lens element150with negative refractive power has an object-side surface151being convex in a paraxial region thereof and an image-side surface152being concave in a paraxial region thereof. The fifth lens element150is made of plastic material and has the object-side surface151and the image-side surface152being both aspheric. The object-side surface151of the fifth lens element150has at least one convex critical point and at least one concave critical point in an off-axis region thereof. The image-side surface152of the fifth lens element150has at least one convex critical point in an off-axis region thereof.

The sixth lens element160with positive refractive power has an object-side surface161being convex in a paraxial region thereof and an image-side surface162being convex in a paraxial region thereof. The sixth lens element160is made of plastic material and has the object-side surface161and the image-side surface162being both aspheric.

The seventh lens element170with negative refractive power has an object-side surface171being concave in a paraxial region thereof and an image-side surface172being convex in a paraxial region thereof. The seventh lens element170is made of plastic material and has the object-side surface171and the image-side surface172being both aspheric.

The eighth lens element180with positive refractive power has an object-side surface181being convex in a paraxial region thereof and an image-side surface182being concave in a paraxial region thereof. The eighth lens element180is made of plastic material and has the object-side surface181and the image-side surface182being both aspheric. The object-side surface181of the eighth lens element180has at least one concave critical point in an off-axis region thereof. The image-side surface182of the eighth lens element180has at least one convex critical point in an off-axis region thereof.

The ninth lens element190with negative refractive power has an object-side surface191being convex in a paraxial region thereof and an image-side surface192being concave in a paraxial region thereof. The ninth lens element190is made of plastic material and has the object-side surface191and the image-side surface192being both aspheric. The object-side surface191of the ninth lens element190has at least one concave critical point in an off-axis region thereof. The image-side surface192of the ninth lens element190has at least one convex critical point in an off-axis region thereof.

The tenth lens element193with positive refractive power has an object-side surface194being convex in a paraxial region thereof and an image-side surface195being concave in a paraxial region thereof. The tenth lens element193is made of plastic material and has the object-side surface194and the image-side surface195being both aspheric. The object-side surface194of the tenth lens element193has at least one concave critical point in an off-axis region thereof. The image-side surface195of the tenth lens element193has at least one convex critical point in an off-axis region thereof.

The eleventh lens element196with negative refractive power has an object-side surface197being concave in a paraxial region thereof and an image-side surface198being concave in a paraxial region thereof. The eleventh lens element196is made of plastic material and has the object-side surface197and the image-side surface198being both aspheric. The object-side surface197of the eleventh lens element196has at least one inflection point in an off-axis region thereof. The image-side surface198of the eleventh lens element196has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT1is made of glass material and located between the eleventh lens element196and the image surface IM1, and will not affect the focal length of the imaging optical lens system. The image sensor IS1is disposed on or near the image surface IM1of the imaging optical lens system.

X is the displacement in parallel with an optical axis from the intersection point of the aspheric surface and the optical axis to a point at a distance of Y from the optical axis on the aspheric surface;

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

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14, 16, 18 and 20.

In the imaging optical lens system of the image capturing unit according to the 1st embodiment, when a focal length of the imaging optical lens system is f, an f-number of the imaging optical lens system is Fno, and half of a maximum field of view of the imaging optical lens system is HFOV, these parameters have the following values: f=6.35 millimeters (mm), Fno=1.85, HFOV=44.1 degrees (deg.).

When an axial distance between the object-side surface111of the first lens element110and the image surface IM1is TL, the following condition is satisfied: TL=8.58 [mm].

When a maximum image height of the imaging optical lens system is ImgH, the following condition is satisfied: ImgH=6.02 [mm].

When an Abbe number of the first lens element110is V1, an Abbe number of the second lens element120is V2, an Abbe number of the third lens element130is V3, an Abbe number of the fourth lens element140is V4, an Abbe number of the fifth lens element150is V5, an Abbe number of the sixth lens element160is V6, an Abbe number of the seventh lens element170is V7, an Abbe number of the eighth lens element180is V8, an Abbe number of the ninth lens element190is V9, an Abbe number of the tenth lens element193is V10, an Abbe number of the eleventh lens element196is V11, a refractive index of the first lens element110is N1, a refractive index of the second lens element120is N2, a refractive index of the third lens element130is N3, a refractive index of the fourth lens element140is N4, a refractive index of the fifth lens element150is N5, a refractive index of the sixth lens element160is N6, a refractive index of the seventh lens element170is N7, a refractive index of the eighth lens element180is N8, a refractive index of the ninth lens element190is N9, a refractive index of the tenth lens element193is N10, and a refractive index of the eleventh lens element196is N11, the following conditions are satisfied: V1/N1=23.91; V2/N2=36.26; V3/N3=16.09; V4/N4=10.90; V5/N5=13.21; V6/N6=36.26; V7/N7=36.26; V8/N8=36.26; V9/N9=23.91; V10/N10=36.26; and V11/N11=36.26.

When a total number of lens elements having an Abbe number smaller than 20 in the imaging optical lens system is V20, the following condition is satisfied: V20=1.

When a total number of lens elements having an Abbe number smaller than 24 in the imaging optical lens system is V24, the following condition is satisfied: V24=2.

When a minimum value among Abbe numbers of all lens elements of the imaging optical lens system is Vmin, the following condition is satisfied: Vmin=18.4. In this embodiment, among the first through eleventh lens elements (110-196), the Abbe number of the fourth lens element140is smaller than Abbe numbers of the other lens elements, and Vmin is equal to the Abbe number of the fourth lens element140.

When a maximum value among Abbe numbers of all lens elements of the imaging optical lens system is Vmax, the following condition is satisfied: Vmax=56.0. In this embodiment, among the first through eleventh lens elements (110-196), the Abbe number of the second lens element120is substantially equal to the Abbe number of the sixth lens element160, the Abbe number of the seventh lens element170, the Abbe number of the eighth lens element180, the Abbe number of the tenth lens element193and the Abbe number of the eleventh lens element196and is larger than Abbe numbers of the other lens elements, and Vmax is equal to the Abbe number of the second lens element120, the Abbe number of the sixth lens element160, the Abbe number of the seventh lens element170, the Abbe number of the eighth lens element180, the Abbe number of the tenth lens element193or the Abbe number of the eleventh lens element196.

When a maximum effective radius of the object-side surface111of the first lens element110is Y1R1, and a maximum effective radius of the image-side surface198of the eleventh lens element196is Y11R2, the following condition is satisfied: Y1R1N11R2=0.35.

When a vertical distance between a critical point on the image-side surface195of the tenth lens element193and the optical axis is Yc10R2, the following condition is satisfied: Yc10R2=1.99 [mm].

When a vertical distance between a critical point on the image-side surface198of the eleventh lens element196and the optical axis is Yc11R2, the following condition is satisfied: Yc11R2=1.38 [mm].

When the vertical distance between the critical point on the image-side surface195of the tenth lens element193and the optical axis is Yc10R2, and the vertical distance between the critical point on the image-side surface198of the eleventh lens element196and the optical axis is Yc11R2, the following condition is satisfied: Yc11R2Nc10R2=0.69.

When the vertical distance between the critical point on the image-side surface198of the eleventh lens element196and the optical axis is Yc11R2, and the focal length of the imaging optical lens system is f, the following condition is satisfied: Yc11R2/f=0.22.

When a curvature radius of the image-side surface198of the eleventh lens element196is R22, and the maximum image height of the imaging optical lens system is ImgH, the following condition is satisfied: R22/ImgH=1.16. When the focal length of the imaging optical lens system is f, and a curvature radius of a lens surface located at an image side of a maximum spacing distance is Ri, the following condition is satisfied: f/|Ri|=0.69. In this embodiment, a maximum spacing distance is a maximum distance in a paraxial region between two adjacent lens surfaces of two adjacent lens elements. In this embodiment, among distances between adjacent two of the first through eleventh lens elements (110-196), the maximum spacing distance is located between the tenth lens element193and the eleventh lens element196. Therefore, a lens surface located at an object side of the maximum spacing distance is the image-side surface195of the tenth lens element193, the lens surface located at the image side of the maximum spacing distance is the object-side surface197of the eleventh lens element196, and Ri is a curvature radius of the object-side surface197of the eleventh lens element196.

When a maximum value among central thicknesses of all lens elements of the imaging optical lens system is CTmax, and a minimum value among central thicknesses of all lens elements of the imaging optical lens system is CTmin, the following condition is satisfied: CTmax/CTmin=2.73. In this embodiment, among the first through eleventh lens elements (110-196), a central thickness of the second lens element120is larger than central thicknesses of the other lens elements of the imaging optical lens system, and CTmax is equal to the central thickness of the second lens element120. In this embodiment, among the first through eleventh lens elements (110-196), a central thickness of the third lens element130is smaller than central thicknesses of the other lens elements of the imaging optical lens system, and CTmin is equal to the central thickness of the third lens element130.

When a maximum value among axial distances between each of all adjacent lens elements of the imaging optical lens system is ATmax, and a minimum value among axial distances between each of all adjacent lens elements of the imaging optical lens system is ATmin, the following condition is satisfied: ATmax/ATmin=52.13. In this embodiment, an axial distance between two adjacent lens elements is a distance in a paraxial region between two adjacent lens surfaces of the two adjacent lens elements. In this embodiment, among the first through eleventh lens elements (110-196), an axial distance between the tenth lens element193and the eleventh lens element196is larger than the axial distances between all the other two adjacent lens elements of the imaging optical lens system, and ATmax is equal to the axial distance between the tenth lens element193and the eleventh lens element196. In this embodiment, among the first through eleventh lens elements (110-196), an axial distance between the second lens element120and the third lens element130is smaller than the axial distances between all the other two adjacent lens elements of the imaging optical lens system, and ATmin is equal to the axial distance between the second lens element120and the third lens element130.

When an axial distance between the object-side surface111of the first lens element110and the image-side surface198of the eleventh lens element196is Td, and a sum of central thicknesses of all lens elements of the imaging optical lens system is ΣCT, the following condition is satisfied: Td/ΣCT=1.51. In this embodiment, ΣCT is a sum of central thicknesses of the first lens element110, the second lens element120, the third lens element130, the fourth lens element140, the fifth lens element150, the sixth lens element160, the seventh lens element170, the eighth lens element180, the ninth lens element190, the tenth lens element193and the eleventh lens element196.

When an axial distance between the aperture stop100and the image-side surface198of the eleventh lens element196is Sd, and the axial distance between the object-side surface111of the first lens element110and the image-side surface198of the eleventh lens element196is Td, the following condition is satisfied: Sd/Td=0.93.

When the axial distance between the object-side surface111of the first lens element110and the image-side surface198of the eleventh lens element196is Td, and an axial distance between the object-side surface151of the fifth lens element150and the image-side surface182of the eighth lens element180is Dr9r16, the following condition is satisfied: Td/Dr9r16=3.77.

When the axial distance between the object-side surface111of the first lens element110and the image surface IM1is TL, and an entrance pupil diameter of the imaging optical lens system is EPD, the following condition is satisfied: TL/EPD=2.50.

When the axial distance between the object-side surface111of the first lens element110and the image surface IM1is TL, and the maximum image height of the imaging optical lens system is ImgH, the following condition is satisfied: TL/ImgH=1.43.

When the axial distance between the object-side surface111of the first lens element110and the image surface IM1is TL, and the focal length of the imaging optical lens system is f, the following condition is satisfied: TL/f=1.35.

When the axial distance between the object-side surface111of the first lens element110and the image surface IM1is TL, and the maximum effective radius of the image-side surface198of the eleventh lens element196is Y11R2, the following condition is satisfied: TLN11R2=1.73.

When the focal length of the imaging optical lens system 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, a focal length of the fifth lens element150is f5, a focal length of the sixth lens element160is f6, a focal length of the seventh lens element170is f7, a focal length of the eighth lens element180is f8, a focal length of the ninth lens element190is f9, a focal length of the tenth lens element193is f10, and a focal length of the eleventh lens element196is f11, the following conditions are satisfied: |f/f1|=0.09; |f/f2|=0.97; |f/f3|=0.33; |f/f4|=0.17; |f/f5|=0.08; |f/f6|=0.53; |f/f7|=0.30; |f/f8|=0.14; |f/f9|=0.16; |f/f10|=0.63; and |f/f11|=0.88.

When the focal length of the imaging optical lens system is f, the focal length of the second lens element120is f2, and the focal length of the third lens element130is f3, the following condition is satisfied: |f/f1|+|f/f2|+|f/f3|=1.39.

When the focal length of the imaging optical lens system is f, the focal length of the tenth lens element193is f10, and the focal length of the eleventh lens element196is f11, the following condition is satisfied: |f/f10|+|f/f11|=1.51.

When the maximum image height of the imaging optical lens system is ImgH, and an axial distance between the image-side surface198of the eleventh lens element196and the image surface IM1is BL, the following condition is satisfied: ImgH/BL=8.72.

FIG. 3is a schematic view of an image capturing unit according to the 2nd embodiment of the present disclosure.FIG. 4shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 2nd embodiment. InFIG. 3, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS2. The imaging optical lens system includes, in order from an object side to an image side along an optical path, an aperture stop200, a first lens element210, a second lens element220, a third lens element230, a fourth lens element240, a fifth lens element250, a sixth lens element260, a seventh lens element270, a stop201, an eighth lens element280, a ninth lens element290, a tenth lens element293, a stop202, an eleventh lens element296, an IR-cut filter FT2and an image surface IM2. The imaging optical lens system includes eleven lens elements (210,220,230,240,250,260,270,280,290,293and296) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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. The first lens element210is made of plastic material and has the object-side surface211and the image-side surface212being both aspheric.

The second lens element220with positive refractive power has an object-side surface221being convex in a paraxial region thereof and an image-side surface222being concave in a paraxial region thereof. The second lens element220is made of plastic material and has the object-side surface221and the image-side surface222being both aspheric. The image-side surface222of the second lens element220has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

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

The fourth lens element240with positive refractive power has an object-side surface241being convex in a paraxial region thereof and an image-side surface242being concave in a paraxial region thereof. The fourth lens element240is made of plastic material and has the object-side surface241and the image-side surface242being both aspheric. The object-side surface241of the fourth lens element240has at least one concave critical point in an off-axis region thereof. The image-side surface242of the fourth lens element240has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The fifth lens element250with negative refractive power has an object-side surface251being concave in a paraxial region thereof and an image-side surface252being concave in a paraxial region thereof. The fifth lens element250is made of plastic material and has the object-side surface251and the image-side surface252being both aspheric.

The sixth lens element260with positive refractive power has an object-side surface261being convex in a paraxial region thereof and an image-side surface262being convex in a paraxial region thereof. The sixth lens element260is made of plastic material and has the object-side surface261and the image-side surface262being both aspheric.

The seventh lens element270with negative refractive power has an object-side surface271being concave in a paraxial region thereof and an image-side surface272being convex in a paraxial region thereof. The seventh lens element270is made of plastic material and has the object-side surface271and the image-side surface272being both aspheric.

The eighth lens element280with positive refractive power has an object-side surface281being convex in a paraxial region thereof and an image-side surface282being concave in a paraxial region thereof. The eighth lens element280is made of plastic material and has the object-side surface281and the image-side surface282being both aspheric. The object-side surface281of the eighth lens element280has at least one concave critical point in an off-axis region thereof. The image-side surface282of the eighth lens element280has at least one convex critical point in an off-axis region thereof.

The ninth lens element290with negative refractive power has an object-side surface291being convex in a paraxial region thereof and an image-side surface292being concave in a paraxial region thereof. The ninth lens element290is made of plastic material and has the object-side surface291and the image-side surface292being both aspheric. The object-side surface291of the ninth lens element290has at least one concave critical point in an off-axis region thereof. The image-side surface292of the ninth lens element290has at least one convex critical point in an off-axis region thereof.

The tenth lens element293with positive refractive power has an object-side surface294being convex in a paraxial region thereof and an image-side surface295being convex in a paraxial region thereof. The tenth lens element293is made of plastic material and has the object-side surface294and the image-side surface295being both aspheric. The object-side surface294of the tenth lens element293has at least one concave critical point in an off-axis region thereof. The image-side surface295of the tenth lens element293has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The eleventh lens element296with negative refractive power has an object-side surface297being convex in a paraxial region thereof and an image-side surface298being concave in a paraxial region thereof. The eleventh lens element296is made of plastic material and has the object-side surface297and the image-side surface298being both aspheric. The object-side surface297of the eleventh lens element296has at least one inflection point in an off-axis region thereof. The object-side surface297of the eleventh lens element296has at least one concave critical point in the off-axis region thereof. The image-side surface298of the eleventh lens element296has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT2is made of glass material and located between the eleventh lens element296and the image surface IM2, and will not affect the focal length of the imaging optical lens system. The image sensor IS2is disposed on or near the image surface IM2of the imaging optical lens system.

FIG. 5is a schematic view of an image capturing unit according to the 3rd embodiment of the present disclosure.FIG. 6shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 3rd embodiment. InFIG. 5, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS3. The imaging optical lens system includes, in order from an object side to an image side along an optical path, an aperture stop300, a first lens element310, a second lens element320, a third lens element330, a stop301, a fourth lens element340, a fifth lens element350, a sixth lens element360, a seventh lens element370, an eighth lens element380, a ninth lens element390, a tenth lens element393, a stop302, an eleventh lens element396, an IR-cut filter FT3and an image surface IM3. The imaging optical lens system includes eleven lens elements (310,320,330,340,350,360,370,380,390,393and396) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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

The second lens element320with positive refractive power has an object-side surface321being convex in a paraxial region thereof and an image-side surface322being concave in a paraxial region thereof. The second lens element320is made of plastic material and has the object-side surface321and the image-side surface322being both aspheric. The image-side surface322of the second lens element320has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

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. The third lens element330is made of plastic material and has the object-side surface331and the image-side surface332being both aspheric. The image-side surface332of the third lens element330has at least one convex critical point in an off-axis region thereof.

The fourth lens element340with positive refractive power has an object-side surface341being convex in a paraxial region thereof and an image-side surface342being concave in a paraxial region thereof. The fourth lens element340is made of plastic material and has the object-side surface341and the image-side surface342being both aspheric. The object-side surface341of the fourth lens element340has at least one concave critical point in an off-axis region thereof. The image-side surface342of the fourth lens element340has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The fifth lens element350with negative refractive power has an object-side surface351being concave in a paraxial region thereof and an image-side surface352being concave in a paraxial region thereof. The fifth lens element350is made of plastic material and has the object-side surface351and the image-side surface352being both aspheric. The object-side surface351of the fifth lens element350has at least one convex critical point in an off-axis region thereof.

The sixth lens element360with positive refractive power has an object-side surface361being convex in a paraxial region thereof and an image-side surface362being convex in a paraxial region thereof. The sixth lens element360is made of plastic material and has the object-side surface361and the image-side surface362being both aspheric.

The seventh lens element370with negative refractive power has an object-side surface371being concave in a paraxial region thereof and an image-side surface372being convex in a paraxial region thereof. The seventh lens element370is made of plastic material and has the object-side surface371and the image-side surface372being both aspheric.

The eighth lens element380with positive refractive power has an object-side surface381being convex in a paraxial region thereof and an image-side surface382being concave in a paraxial region thereof. The eighth lens element380is made of plastic material and has the object-side surface381and the image-side surface382being both aspheric. The object-side surface381of the eighth lens element380has at least one concave critical point in an off-axis region thereof. The image-side surface382of the eighth lens element380has at least one convex critical point in an off-axis region thereof.

The ninth lens element390with positive refractive power has an object-side surface391being convex in a paraxial region thereof and an image-side surface392being concave in a paraxial region thereof. The ninth lens element390is made of plastic material and has the object-side surface391and the image-side surface392being both aspheric. The object-side surface391of the ninth lens element390has at least one concave critical point in an off-axis region thereof. The image-side surface392of the ninth lens element390has at least one convex critical point in an off-axis region thereof.

The tenth lens element393with positive refractive power has an object-side surface394being convex in a paraxial region thereof and an image-side surface395being concave in a paraxial region thereof. The tenth lens element393is made of plastic material and has the object-side surface394and the image-side surface395being both aspheric. The object-side surface394of the tenth lens element393has at least one concave critical point in an off-axis region thereof. The image-side surface395of the tenth lens element393has at least one convex critical point in an off-axis region thereof.

The eleventh lens element396with negative refractive power has an object-side surface397being convex in a paraxial region thereof and an image-side surface398being concave in a paraxial region thereof. The eleventh lens element396is made of plastic material and has the object-side surface397and the image-side surface398being both aspheric. The object-side surface397of the eleventh lens element396has at least one inflection point in an off-axis region thereof. The object-side surface397of the eleventh lens element396has at least one concave critical point in the off-axis region thereof. The image-side surface398of the eleventh lens element396has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT3is made of glass material and located between the eleventh lens element396and the image surface IM3, and will not affect the focal length of the imaging optical lens system. The image sensor IS3is disposed on or near the image surface IM3of the imaging optical lens system.

FIG. 7is a schematic view of an image capturing unit according to the 4th embodiment of the present disclosure.FIG. 8shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 4th embodiment. InFIG. 7, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS4. The imaging optical lens system includes, in order from an object side to an image side along an optical path, a first lens element410, an aperture stop400, a second lens element420, a third lens element430, a fourth lens element440, a fifth lens element450, a sixth lens element460, a seventh lens element470, a stop401, an eighth lens element480, a ninth lens element490, a tenth lens element493, an eleventh lens element496, an IR-cut filter FT4and an image surface IM4. The imaging optical lens system includes eleven lens elements (410,420,430,440,450,460,470,480,490,493and496) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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. The first lens element410is made of plastic material and has the object-side surface411and the image-side surface412being both aspheric.

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

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

The fourth lens element440with negative refractive power has an object-side surface441being convex in a paraxial region thereof and an image-side surface442being concave in a paraxial region thereof. The fourth lens element440is made of plastic material and has the object-side surface441and the image-side surface442being both 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. The fifth lens element450is made of plastic material and has the object-side surface451and the image-side surface452being both aspheric. The object-side surface451of the fifth lens element450has at least one concave critical point in an off-axis region thereof. The image-side surface452of the fifth lens element450has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The sixth lens element460with positive refractive power has an object-side surface461being concave in a paraxial region thereof and an image-side surface462being convex in a paraxial region thereof. The sixth lens element460is made of plastic material and has the object-side surface461and the image-side surface462being both aspheric.

The seventh lens element470with negative refractive power has an object-side surface471being concave in a paraxial region thereof and an image-side surface472being convex in a paraxial region thereof. The seventh lens element470is made of plastic material and has the object-side surface471and the image-side surface472being both aspheric.

The eighth lens element480with positive refractive power has an object-side surface481being convex in a paraxial region thereof and an image-side surface482being concave in a paraxial region thereof. The eighth lens element480is made of plastic material and has the object-side surface481and the image-side surface482being both aspheric. The object-side surface481of the eighth lens element480has at least one concave critical point in an off-axis region thereof. The image-side surface482of the eighth lens element480has at least one convex critical point in an off-axis region thereof.

The ninth lens element490with negative refractive power has an object-side surface491being convex in a paraxial region thereof and an image-side surface492being concave in a paraxial region thereof. The ninth lens element490is made of plastic material and has the object-side surface491and the image-side surface492being both aspheric. The object-side surface491of the ninth lens element490has at least one concave critical point in an off-axis region thereof. The image-side surface492of the ninth lens element490has at least one convex critical point in an off-axis region thereof.

The tenth lens element493with positive refractive power has an object-side surface494being convex in a paraxial region thereof and an image-side surface495being concave in a paraxial region thereof. The tenth lens element493is made of plastic material and has the object-side surface494and the image-side surface495being both aspheric. The object-side surface494of the tenth lens element493has at least one concave critical point in an off-axis region thereof. The image-side surface495of the tenth lens element493has at least one convex critical point in an off-axis region thereof.

The eleventh lens element496with negative refractive power has an object-side surface497being concave in a paraxial region thereof and an image-side surface498being concave in a paraxial region thereof. The eleventh lens element496is made of plastic material and has the object-side surface497and the image-side surface498being both aspheric. The object-side surface497of the eleventh lens element496has at least one inflection point in an off-axis region thereof. The object-side surface497of the eleventh lens element496has at least one convex critical point in the off-axis region thereof. The image-side surface498of the eleventh lens element496has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT4is made of glass material and located between the eleventh lens element496and the image surface IM4, and will not affect the focal length of the imaging optical lens system. The image sensor IS4is disposed on or near the image surface IM4of the imaging optical lens system.

FIG. 9is a schematic view of an image capturing unit according to the 5th embodiment of the present disclosure.FIG. 10shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 5th embodiment. InFIG. 9, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS5. The imaging optical lens system includes, in order from an object side to an image side along an optical path, an aperture stop500, a first lens element510, a second lens element520, a third lens element530, a fourth lens element540, a stop501, a fifth lens element550, a sixth lens element560, a seventh lens element570, a stop502, an eighth lens element580, a ninth lens element590, a tenth lens element593, an eleventh lens element596, an IR-cut filter FT5and an image surface IM5. The imaging optical lens system includes eleven lens elements (510,520,530,540,550,560,570,580,590,593and596) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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. The first lens element510is made of plastic material and has the object-side surface511and the image-side surface512being both aspheric.

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

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

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

The fifth lens element550with positive refractive power has an object-side surface551being convex in a paraxial region thereof and an image-side surface552being convex in a paraxial region thereof. The fifth lens element550is made of plastic material and has the object-side surface551and the image-side surface552being both aspheric. The object-side surface551of the fifth lens element550has at least one concave critical point in an off-axis region thereof. The image-side surface552of the fifth lens element550has at least one concave critical point in an off-axis region thereof.

The sixth lens element560with positive refractive power has an object-side surface561being concave in a paraxial region thereof and an image-side surface562being convex in a paraxial region thereof. The sixth lens element560is made of plastic material and has the object-side surface561and the image-side surface562being both aspheric.

The seventh lens element570with negative refractive power has an object-side surface571being concave in a paraxial region thereof and an image-side surface572being convex in a paraxial region thereof. The seventh lens element570is made of plastic material and has the object-side surface571and the image-side surface572being both aspheric.

The eighth lens element580with positive refractive power has an object-side surface581being convex in a paraxial region thereof and an image-side surface582being concave in a paraxial region thereof. The eighth lens element580is made of plastic material and has the object-side surface581and the image-side surface582being both aspheric. The object-side surface581of the eighth lens element580has at least one concave critical point in an off-axis region thereof. The image-side surface582of the eighth lens element580has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The ninth lens element590with negative refractive power has an object-side surface591being convex in a paraxial region thereof and an image-side surface592being concave in a paraxial region thereof. The ninth lens element590is made of plastic material and has the object-side surface591and the image-side surface592being both aspheric. The object-side surface591of the ninth lens element590has at least one concave critical point in an off-axis region thereof. The image-side surface592of the ninth lens element590has at least one convex critical point in an off-axis region thereof.

The tenth lens element593with positive refractive power has an object-side surface594being convex in a paraxial region thereof and an image-side surface595being concave in a paraxial region thereof. The tenth lens element593is made of plastic material and has the object-side surface594and the image-side surface595being both aspheric. The object-side surface594of the tenth lens element593has at least one concave critical point in an off-axis region thereof. The image-side surface595of the tenth lens element593has at least one convex critical point in an off-axis region thereof.

The eleventh lens element596with negative refractive power has an object-side surface597being concave in a paraxial region thereof and an image-side surface598being concave in a paraxial region thereof. The eleventh lens element596is made of plastic material and has the object-side surface597and the image-side surface598being both aspheric. The object-side surface597of the eleventh lens element596has at least one inflection point in an off-axis region thereof. The image-side surface598of the eleventh lens element596has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT5is made of glass material and located between the eleventh lens element596and the image surface IM5, and will not affect the focal length of the imaging optical lens system. The image sensor IS5is disposed on or near the image surface IM5of the imaging optical lens system.

FIG. 11is a schematic view of an image capturing unit according to the 6th embodiment of the present disclosure.FIG. 12shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 6th embodiment. InFIG. 11, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS6. The imaging optical lens system includes, in order from an object side to an image side along an optical path, an aperture stop600, a first lens element610, a second lens element620, a third lens element630, a stop601, a fourth lens element640, a fifth lens element650, a sixth lens element660, a seventh lens element670, an eighth lens element680, a ninth lens element690, a tenth lens element693, an eleventh lens element696, an IR-cut filter FT6and an image surface IM6. The imaging optical lens system includes eleven lens elements (610,620,630,640,650,660,670,680,690,693and696) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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. The first lens element610is made of plastic material and has the object-side surface611and the image-side surface612being both aspheric.

The second lens element620with negative refractive power has an object-side surface621being convex in a paraxial region thereof and an image-side surface622being concave in a paraxial region thereof. The second lens element620is made of plastic material and has the object-side surface621and the image-side surface622being both 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. The third lens element630is made of plastic material and has the object-side surface631and the image-side surface632being both aspheric. The object-side surface631of the third lens element630has at least one concave critical point in an off-axis region thereof.

The fourth lens element640with positive refractive power has an object-side surface641being convex in a paraxial region thereof and an image-side surface642being convex in a paraxial region thereof. The fourth lens element640is made of plastic material and has the object-side surface641and the image-side surface642being both aspheric. The object-side surface641of the fourth lens element640has at least one concave critical point in an off-axis region thereof.

The fifth lens element650with negative refractive power has an object-side surface651being concave in a paraxial region thereof and an image-side surface652being convex in a paraxial region thereof. The fifth lens element650is made of plastic material and has the object-side surface651and the image-side surface652being both aspheric.

The sixth lens element660with negative refractive power has an object-side surface661being concave in a paraxial region thereof and an image-side surface662being concave in a paraxial region thereof. The sixth lens element660is made of plastic material and has the object-side surface661and the image-side surface662being both aspheric. The object-side surface661of the sixth lens element660has at least one convex critical point in an off-axis region thereof. The image-side surface662of the sixth lens element660has at least one convex critical point in an off-axis region thereof.

The seventh lens element670with positive refractive power has an object-side surface671being convex in a paraxial region thereof and an image-side surface672being convex in a paraxial region thereof. The seventh lens element670is made of plastic material and has the object-side surface671and the image-side surface672being both aspheric. The object-side surface671of the seventh lens element670has at least one concave critical point in an off-axis region thereof.

The eighth lens element680with negative refractive power has an object-side surface681being convex in a paraxial region thereof and an image-side surface682being concave in a paraxial region thereof. The eighth lens element680is made of plastic material and has the object-side surface681and the image-side surface682being both aspheric. The object-side surface681of the eighth lens element680has at least one concave critical point in an off-axis region thereof. The image-side surface682of the eighth lens element680has at least one convex critical point in an off-axis region thereof.

The ninth lens element690with positive refractive power has an object-side surface691being convex in a paraxial region thereof and an image-side surface692being concave in a paraxial region thereof. The ninth lens element690is made of plastic material and has the object-side surface691and the image-side surface692being both aspheric. The object-side surface691of the ninth lens element690has at least one concave critical point in an off-axis region thereof. The image-side surface692of the ninth lens element690has at least one convex critical point in an off-axis region thereof.

The tenth lens element693with positive refractive power has an object-side surface694being convex in a paraxial region thereof and an image-side surface695being concave in a paraxial region thereof. The tenth lens element693is made of plastic material and has the object-side surface694and the image-side surface695being both aspheric. The object-side surface694of the tenth lens element693has at least one concave critical point in an off-axis region thereof. The image-side surface695of the tenth lens element693has at least one convex critical point in an off-axis region thereof.

The eleventh lens element696with negative refractive power has an object-side surface697being concave in a paraxial region thereof and an image-side surface698being concave in a paraxial region thereof. The eleventh lens element696is made of plastic material and has the object-side surface697and the image-side surface698being both aspheric. The object-side surface697of the eleventh lens element696has at least one inflection point in an off-axis region thereof. The object-side surface697of the eleventh lens element696has at least one convex critical point in the off-axis region thereof. The image-side surface698of the eleventh lens element696has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT6is made of glass material and located between the eleventh lens element696and the image surface IM6, and will not affect the focal length of the imaging optical lens system. The image sensor IS6is disposed on or near the image surface IM6of the imaging optical lens system.

FIG. 13is a schematic view of an image capturing unit according to the 7th embodiment of the present disclosure.FIG. 14shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 7th embodiment. InFIG. 13, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS7. The imaging optical lens system includes, in order from an object side to an image side along an optical path, a first lens element710, an aperture stop700, a second lens element720, a third lens element730, a fourth lens element740, a fifth lens element750, a sixth lens element760, a seventh lens element770, an eighth lens element780, a ninth lens element790, a tenth lens element793, an eleventh lens element796, an IR-cut filter FT7and an image surface IM7. The imaging optical lens system includes eleven lens elements (710,720,730,740,750,760,770,780,790,793and796) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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. The first lens element710is made of plastic material and has the object-side surface711and the image-side surface712being both aspheric.

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

The third lens element730with negative refractive power has an object-side surface731being convex in a paraxial region thereof and an image-side surface732being concave in a paraxial region thereof. The third lens element730is made of plastic material and has the object-side surface731and the image-side surface732being both aspheric. The object-side surface731of the third lens element730has at least one concave critical point in an off-axis region thereof.

The fourth lens element740with positive refractive power has an object-side surface741being convex in a paraxial region thereof and an image-side surface742being convex in a paraxial region thereof. The fourth lens element740is made of plastic material and has the object-side surface741and the image-side surface742being both aspheric. The object-side surface741of the fourth lens element740has at least one concave critical point in an off-axis region thereof.

The fifth lens element750with positive refractive power has an object-side surface751being concave in a paraxial region thereof and an image-side surface752being convex in a paraxial region thereof. The fifth lens element750is made of plastic material and has the object-side surface751and the image-side surface752being both aspheric.

The sixth lens element760with negative refractive power has an object-side surface761being concave in a paraxial region thereof and an image-side surface762being convex in a paraxial region thereof. The sixth lens element760is made of plastic material and has the object-side surface761and the image-side surface762being both aspheric.

The seventh lens element770with positive refractive power has an object-side surface771being concave in a paraxial region thereof and an image-side surface772being convex in a paraxial region thereof. The seventh lens element770is made of plastic material and has the object-side surface771and the image-side surface772being both aspheric.

The eighth lens element780with negative refractive power has an object-side surface781being concave in a paraxial region thereof and an image-side surface782being concave in a paraxial region thereof. The eighth lens element780is made of plastic material and has the object-side surface781and the image-side surface782being both aspheric. The image-side surface782of the eighth lens element780has at least one convex critical point in an off-axis region thereof.

The ninth lens element790with positive refractive power has an object-side surface791being convex in a paraxial region thereof and an image-side surface792being concave in a paraxial region thereof. The ninth lens element790is made of plastic material and has the object-side surface791and the image-side surface792being both aspheric. The object-side surface791of the ninth lens element790has at least one concave critical point in an off-axis region thereof. The image-side surface792of the ninth lens element790has at least one convex critical point in an off-axis region thereof.

The tenth lens element793with positive refractive power has an object-side surface794being convex in a paraxial region thereof and an image-side surface795being concave in a paraxial region thereof. The tenth lens element793is made of plastic material and has the object-side surface794and the image-side surface795being both aspheric. The object-side surface794of the tenth lens element793has at least one concave critical point in an off-axis region thereof. The image-side surface795of the tenth lens element793has at least one convex critical point in an off-axis region thereof.

The eleventh lens element796with negative refractive power has an object-side surface797being concave in a paraxial region thereof and an image-side surface798being concave in a paraxial region thereof. The eleventh lens element796is made of plastic material and has the object-side surface797and the image-side surface798being both aspheric. The object-side surface797of the eleventh lens element796has at least one inflection point in an off-axis region thereof. The object-side surface797of the eleventh lens element796has at least one convex critical point in the off-axis region thereof. The image-side surface798of the eleventh lens element796has at least one convex critical point in an off-axis region thereof.

The IR-cut filter FT7is made of glass material and located between the eleventh lens element796and the image surface IM7, and will not affect the focal length of the imaging optical lens system. The image sensor IS7is disposed on or near the image surface IM7of the imaging optical lens system.

FIG. 15is a schematic view of an image capturing unit according to the 8th embodiment of the present disclosure.FIG. 16shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 8th embodiment. InFIG. 15, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS8. The imaging optical lens system includes, in order from an object side to an image side along an optical path, a first lens element810, a second lens element820, an aperture stop800, a third lens element830, a fourth lens element840, a fifth lens element850, a sixth lens element860, a seventh lens element870, an eighth lens element880, a ninth lens element890, a tenth lens element893, an eleventh lens element896, an IR-cut filter FT8and an image surface IM8. The imaging optical lens system includes eleven lens elements (810,820,830,840,850,860,870,880,890,893and896) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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

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

The third lens element830with negative refractive power has an object-side surface831being concave in a paraxial region thereof and an image-side surface832being concave in a paraxial region thereof. The third lens element830is made of plastic material and has the object-side surface831and the image-side surface832being both aspheric. The image-side surface832of the third lens element830has at least one convex critical point in an off-axis region thereof.

The fourth lens element840with positive refractive power has an object-side surface841being convex in a paraxial region thereof and an image-side surface842being convex in a paraxial region thereof. The fourth lens element840is made of plastic material and has the object-side surface841and the image-side surface842being both aspheric. The object-side surface841of the fourth lens element840has at least one concave critical point in an off-axis region thereof.

The fifth lens element850with negative refractive power has an object-side surface851being concave in a paraxial region thereof and an image-side surface852being concave in a paraxial region thereof. The fifth lens element850is made of plastic material and has the object-side surface851and the image-side surface852being both aspheric. The image-side surface852of the fifth lens element850has at least one convex critical point in an off-axis region thereof.

The sixth lens element860with positive refractive power has an object-side surface861being concave in a paraxial region thereof and an image-side surface862being convex in a paraxial region thereof. The sixth lens element860is made of plastic material and has the object-side surface861and the image-side surface862being both aspheric. The object-side surface861of the sixth lens element860has at least one convex critical point in an off-axis region thereof.

The seventh lens element870with positive refractive power has an object-side surface871being concave in a paraxial region thereof and an image-side surface872being convex in a paraxial region thereof. The seventh lens element870is made of plastic material and has the object-side surface871and the image-side surface872being both aspheric.

The eighth lens element880with negative refractive power has an object-side surface881being convex in a paraxial region thereof and an image-side surface882being concave in a paraxial region thereof. The eighth lens element880is made of plastic material and has the object-side surface881and the image-side surface882being both aspheric. The object-side surface881of the eighth lens element880has at least one concave critical point in an off-axis region thereof. The image-side surface882of the eighth lens element880has at least one convex critical point in an off-axis region thereof.

The ninth lens element890with positive refractive power has an object-side surface891being convex in a paraxial region thereof and an image-side surface892being concave in a paraxial region thereof. The ninth lens element890is made of plastic material and has the object-side surface891and the image-side surface892being both aspheric. The object-side surface891of the ninth lens element890has at least one concave critical point in an off-axis region thereof. The image-side surface892of the ninth lens element890has at least one convex critical point in an off-axis region thereof.

The tenth lens element893with positive refractive power has an object-side surface894being convex in a paraxial region thereof and an image-side surface895being concave in a paraxial region thereof. The tenth lens element893is made of plastic material and has the object-side surface894and the image-side surface895being both aspheric. The object-side surface894of the tenth lens element893has at least one concave critical point in an off-axis region thereof. The image-side surface895of the tenth lens element893has at least one convex critical point in an off-axis region thereof.

The eleventh lens element896with negative refractive power has an object-side surface897being concave in a paraxial region thereof and an image-side surface898being concave in a paraxial region thereof. The eleventh lens element896is made of plastic material and has the object-side surface897and the image-side surface898being both aspheric. The object-side surface897of the eleventh lens element896has at least one inflection point in an off-axis region thereof. The image-side surface898of the eleventh lens element896has at least one convex critical point and at least one concave critical point in an off-axis region thereof.

The IR-cut filter FT8is made of glass material and located between the eleventh lens element896and the image surface IM8, and will not affect the focal length of the imaging optical lens system. The image sensor IS8is disposed on or near the image surface IM8of the imaging optical lens system.

Moreover, these parameters can be calculated from Table 15 and Table 16 as the following values and satisfy the following conditions:

FIG. 17is a schematic view of an image capturing unit according to the 9th embodiment of the present disclosure.FIG. 18shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 9th embodiment. InFIG. 17, the image capturing unit includes the imaging optical lens system (its reference numeral is omitted) of the present disclosure and an image sensor IS9. The imaging optical lens system includes, in order from an object side to an image side along an optical path, a first lens element910, a second lens element920, an aperture stop900, a third lens element930, a fourth lens element940, a fifth lens element950, a sixth lens element960, a seventh lens element970, an eighth lens element980, a ninth lens element990, a tenth lens element993, an eleventh lens element996, an IR-cut filter FT9and an image surface IM9. The imaging optical lens system includes eleven lens elements (910,920,930,940,950,960,970,980,990,993and996) with no additional lens element disposed between each of the adjacent eleven lens elements, wherein there is an air gap in a paraxial region between each of all adjacent lens elements.

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

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

The third lens element930with negative refractive power has an object-side surface931being convex in a paraxial region thereof and an image-side surface932being concave in a paraxial region thereof. The third lens element930is made of plastic material and has the object-side surface931and the image-side surface932being both aspheric. The object-side surface931of the third lens element930has at least one concave critical point in an off-axis region thereof. The image-side surface932of the third lens element930has at least one convex critical point in an off-axis region thereof.

The fourth lens element940with positive refractive power has an object-side surface941being convex in a paraxial region thereof and an image-side surface942being convex in a paraxial region thereof. The fourth lens element940is made of plastic material and has the object-side surface941and the image-side surface942being both aspheric. The object-side surface941of the fourth lens element940has at least one concave critical point in an off-axis region thereof.

The fifth lens element950with negative refractive power has an object-side surface951being concave in a paraxial region thereof and an image-side surface952being concave in a paraxial region thereof. The fifth lens element950is made of plastic material and has the object-side surface951and the image-side surface952being both aspheric. The image-side surface952of the fifth lens element950has at least one convex critical point in an off-axis region thereof.

The sixth lens element960with positive refractive power has an object-side surface961being concave in a paraxial region thereof and an image-side surface962being convex in a paraxial region thereof. The sixth lens element960is made of plastic material and has the object-side surface961and the image-side surface962being both aspheric. The object-side surface961of the sixth lens element960has at least one convex critical point in an off-axis region thereof.

The seventh lens element970with positive refractive power has an object-side surface971being concave in a paraxial region thereof and an image-side surface972being convex in a paraxial region thereof. The seventh lens element970is made of plastic material and has the object-side surface971and the image-side surface972being both aspheric.

The eighth lens element980with negative refractive power has an object-side surface981being convex in a paraxial region thereof and an image-side surface982being concave in a paraxial region thereof. The eighth lens element980is made of plastic material and has the object-side surface981and the image-side surface982being both aspheric. The object-side surface981of the eighth lens element980has at least one concave critical point in an off-axis region thereof. The image-side surface982of the eighth lens element980has at least one convex critical point in an off-axis region thereof.

The ninth lens element990with positive refractive power has an object-side surface991being convex in a paraxial region thereof and an image-side surface992being convex in a paraxial region thereof. The ninth lens element990is made of plastic material and has the object-side surface991and the image-side surface992being both aspheric. The object-side surface991of the ninth lens element990has at least one concave critical point in an off-axis region thereof.

The tenth lens element993with negative refractive power has an object-side surface994being convex in a paraxial region thereof and an image-side surface995being concave in a paraxial region thereof. The tenth lens element993is made of plastic material and has the object-side surface994and the image-side surface995being both aspheric. The object-side surface994of the tenth lens element993has at least one concave critical point in an off-axis region thereof. The image-side surface995of the tenth lens element993has at least one convex critical point in an off-axis region thereof.

The eleventh lens element996with negative refractive power has an object-side surface997being concave in a paraxial region thereof and an image-side surface998being concave in a paraxial region thereof. The eleventh lens element996is made of plastic material and has the object-side surface997and the image-side surface998being both aspheric. The object-side surface997of the eleventh lens element996has at least one inflection point in an off-axis region thereof. The image-side surface998of the eleventh lens element996has at least one convex critical point.

The IR-cut filter FT9is made of glass material and located between the eleventh lens element996and the image surface IM9, and will not affect the focal length of the imaging optical lens system. The image sensor IS9is disposed on or near the image surface IM9of the imaging optical lens system.

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

Moreover, these parameters can be calculated from Table 17 and Table 18 as the following values and satisfy the following conditions:

FIG. 19is a perspective view of an image capturing unit according to the 10th embodiment of the present disclosure. In this embodiment, an image capturing unit10is a camera module including a lens unit11, a driving device12, an image sensor13and an image stabilizer14. The lens unit11includes the imaging optical lens system disclosed in the 1st embodiment, a barrel and a holder member (their reference numerals are omitted) for holding the imaging optical lens system. However, the lens unit11may alternatively be provided with the imaging optical lens system disclosed in other abovementioned embodiments, and the present disclosure is not limited thereto. The imaging light converges in the lens unit11of the image capturing unit10to generate an image with the driving device12utilized for image focusing on the image sensor13, and the generated image is then digitally transmitted to other electronic component for further processing.

The driving device12can have auto focusing functionality, and different driving configurations can be obtained through the usages of voice coil motors (VCM), micro electro-mechanical systems (MEMS), piezoelectric systems, or shape memory alloy materials. The driving device12is favorable for obtaining a better imaging position of the lens unit11, so that a clear image of the imaged object can be captured by the lens unit11with different object distances. The image sensor13(for example, CCD or CMOS), which can feature high photosensitivity and low noise, is disposed on the image surface of the imaging optical lens system to provide higher image quality.

The image stabilizer14, such as an accelerometer, a gyro sensor and a Hall Effect sensor, is configured to work with the driving device12to provide optical image stabilization (01S). The driving device12working with the image stabilizer14is favorable for compensating for pan and tilt of the lens unit11to reduce blurring associated with motion during exposure. In some cases, the compensation can be provided by electronic image stabilization (EIS) with image processing software, thereby improving image quality while in motion or low-light conditions.

FIG. 20is one perspective view of an electronic device according to the 11th embodiment of the present disclosure.FIG. 21is another perspective view of the electronic device inFIG. 20.FIG. 22is a block diagram of the electronic device inFIG. 20.

In this embodiment, an electronic device20is a smartphone including the image capturing unit10disclosed in the 10th embodiment, an image capturing unit10a, an image capturing unit10b, an image capturing unit10c, an image capturing unit10d, a flash module21, a focus assist module22, an image signal processor23, a user interface24and an image software processor25. The image capturing unit10and the image capturing unit10aare disposed on the same side of the electronic device20and each of the image capturing units10and10ahas a single focal point. The image capturing unit10b, the image capturing unit10c, the image capturing unit10dand the user interface24are disposed on the opposite side of the electronic device20and the user interface24is a display unit, such that the image capturing units10b,10c,10dcan be front-facing cameras of the electronic device20for taking selfies, but the present disclosure is not limited thereto. Furthermore, each of the image capturing units10a,10b,10cand10dcan include the imaging optical lens system of the present disclosure and can have a configuration similar to that of the image capturing unit10. In detail, each of the image capturing units10a,10b,10cand10dcan include a lens unit, a driving device, an image sensor and an image stabilizer, and each of the lens unit can include an optical lens assembly such as the imaging optical lens system of the present disclosure, a barrel and a holder member for holding the optical lens assembly.

The image capturing unit10is a wide-angle image capturing unit, the image capturing unit10ais an ultra-wide-angle image capturing unit, the image capturing unit10bis a wide-angle image capturing unit, the image capturing unit10cis an ultra-wide-angle image capturing unit, and the image capturing unit10dis a ToF (time of flight) image capturing unit. In this embodiment, the image capturing units10,10ahave different fields of view, such that the electronic device20can have various magnification ratios so as to meet the requirement of optical zoom functionality. In addition, the image capturing unit10dcan determine depth information of the imaged object. In this embodiment, the electronic device20includes multiple image capturing units10,10a,10b,10cand10d, but the present disclosure is not limited to the number and arrangement of image capturing units.

When a user captures images of an object26, the light rays converge in the image capturing unit10or the image capturing unit10ato generate images, and the flash module21is activated for light supplement. The focus assist module22detects the object distance of the imaged object26to achieve fast auto focusing. The image signal processor23is configured to optimize the captured image to improve image quality. The light beam emitted from the focus assist module22can be either conventional infrared or laser. In addition, the light rays may converge in the image capturing unit10b,10cor10dto generate images. The user interface24can include a touch screen, and the user is able to interact with the user interface24and the image software processor25having multiple functions to capture images and complete image processing. Alternatively, the user may capture images via a physical button. The image processed by the image software processor25can be displayed on the user interface24.

FIG. 23is one perspective view of an electronic device according to the 12th embodiment of the present disclosure.

In this embodiment, an electronic device30is a smartphone including the image capturing unit10disclosed in the 10th embodiment, an image capturing unit10e, an image capturing unit10f, a flash module31, a focus assist module, an image signal processor, a display unit and an image software processor (not shown). The image capturing unit10, the image capturing unit10eand the image capturing unit10fare disposed on the same side of the electronic device30, while the display unit is disposed on the opposite side of the electronic device30. Furthermore, each of the image capturing units10eand10fcan include the imaging optical lens system of the present disclosure and can have a configuration similar to that of the image capturing unit10, so the details in this regard will not be provided again.

The image capturing unit10is a wide-angle image capturing unit, the image capturing unit10eis a telephoto image capturing unit, and the image capturing unit10fis an ultra-wide-angle image capturing unit. In this embodiment, the image capturing units10,10eand10fhave different fields of view, such that the electronic device30can have various magnification ratios so as to meet the requirement of optical zoom functionality. Moreover, the image capturing unit10ecan be a telephoto image capturing unit having a light-folding element configuration, such that the total track length of the image capturing unit10eis not limited by the thickness of the electronic device30. Moreover, the light-folding element configuration of the image capturing unit10ecan be similar to, for example, one of the structures shown inFIG. 26toFIG. 28which can be referred to foregoing descriptions corresponding toFIG. 26toFIG. 28so the details in this regard will not be provided again. In this embodiment, the electronic device30includes multiple image capturing units10,10eand10f, but the present disclosure is not limited to the number and arrangement of image capturing units. When a user captures images of an object, light rays converge in the image capturing unit10,10eor10fto generate images, and the flash module31is activated for light supplement. Further, the subsequent processes are performed in a manner similar to the abovementioned embodiment, so the details in this regard will not be provided again.

FIG. 24is one perspective view of an electronic device according to the 13th embodiment of the present disclosure.

In this embodiment, an electronic device40is a smartphone including the image capturing unit10disclosed in the 10th embodiment, an image capturing unit10g, an image capturing unit10h, an image capturing unit10i, an image capturing unit10j, an image capturing unit10k, an image capturing unit10m, an image capturing unit10n, an image capturing unit10p, a flash module41, a focus assist module, an image signal processor, a display unit and an image software processor (not shown). The image capturing units10,10g,10h,10i,10j,10k,10m,10nand10pare disposed on the same side of the electronic device40, while the display unit is disposed on the opposite side of the electronic device40. Furthermore, each of the image capturing units10g,10h,10i,10j,10k,10m,10nand10pcan include the imaging optical lens system of the present disclosure and can have a configuration similar to that of the image capturing unit10, so the details in this regard will not be provided again.

The image capturing unit10is a wide-angle image capturing unit, the image capturing unit10gis a telephoto image capturing unit, the image capturing unit10his a telephoto image capturing unit, the image capturing unit10iis a wide-angle image capturing unit, the image capturing unit10jis an ultra-wide-angle image capturing unit, the image capturing unit10kis an ultra-wide-angle image capturing unit, the image capturing unit10mis a telephoto image capturing unit, the image capturing unit10nis a telephoto image capturing unit, and the image capturing unit10pis a ToF image capturing unit. In this embodiment, the image capturing units10,10g,10h,10i,10j,10k,10mand10nhave different fields of view, such that the electronic device40can have various magnification ratios so as to meet the requirement of optical zoom functionality. Moreover, each of the image capturing units10gand10hcan be a telephoto image capturing unit having a light-folding element configuration. Moreover, the light-folding element configuration of each of the image capturing unit10gand10hcan be similar to, for example, one of the structures shown inFIG. 26toFIG. 28which can be referred to foregoing descriptions corresponding toFIG. 26toFIG. 28so the details in this regard will not be provided again. In addition, the image capturing unit10pcan determine depth information of the imaged object. In this embodiment, the electronic device40includes multiple image capturing units10,10g,10h,10i,10j,10k,10m,10nand10p, but the present disclosure is not limited to the number and arrangement of image capturing units. When a user captures images of an object, the light rays converge in the image capturing unit10,10g,10h,10i,10j,10k,10m,10nor10pto generate images, and the flash module41is activated for light supplement. Further, the subsequent processes are performed in a manner similar to the abovementioned embodiments, so the details in this regard will not be provided again.

The smartphone in this embodiment is only exemplary for showing the image capturing unit10of the present disclosure installed in an electronic device, and the present disclosure is not limited thereto. The image capturing unit10can be optionally applied to optical systems with a movable focus. Furthermore, the imaging optical lens system of the image capturing unit10features good capability in aberration corrections and high image quality, and can be applied to 3D (three-dimensional) image capturing applications, in products such as digital cameras, mobile devices, digital tablets, smart televisions, network surveillance devices, dashboard cameras, vehicle backup cameras, multi-camera devices, image recognition systems, motion sensing input devices, wearable devices and other electronic imaging devices.