CN109856781B

CN109856781B - Optical lens group for imaging

Info

Publication number: CN109856781B
Application number: CN201910266129.XA
Authority: CN
Inventors: 许伯纶; 陈纬彧
Original assignee: Largan Precision Co Ltd
Current assignee: Largan Precision Co Ltd
Priority date: 2016-01-13
Filing date: 2016-01-13
Publication date: 2020-12-29
Anticipated expiration: 2036-01-13
Also published as: CN106970452A; CN109856781A; CN106970452B

Abstract

The invention discloses an optical lens assembly for imaging, which sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side. The first lens element with positive refractive power has a convex object-side surface at paraxial region. The second lens element with negative refractive power has a concave object-side surface at paraxial region. The third lens element has a convex object-side surface at a paraxial region. The fourth lens element with negative refractive power has a concave image-side surface at a paraxial region thereof, and has at least one convex image-side surface at an off-axis region thereof, wherein the object-side surface and the image-side surface of the fourth lens element are aspheric. The object-side surface and the image-side surface of the fifth lens element are aspheric. The imaging optical lens group has five lenses, and an air space is arranged between each two adjacent lenses on an optical axis.

Description

Optical lens group for imaging

The application is a divisional application, and the application date of the original application is as follows: 2016, month 01, and day 13; the application numbers are: 201610020537.3, respectively; the invention has the name: an optical lens assembly for imaging, an image capturing device and an electronic device.

Technical Field

The present invention relates to an optical lens group for imaging.

Background

With the rapid development of the miniaturized camera lens, the demand of the micro image capturing module is gradually increased, and the photosensitive element of the general camera lens is not limited to a photosensitive coupling Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) Device, and the pixel size of the photosensitive element is reduced with the advance of the Semiconductor process, and in addition, the current electronic product is developed with a good function, a light, thin, short and small shape, so the miniaturized camera lens with good imaging quality is the mainstream in the current market.

In recent years, optical lenses with telescopic characteristics are also being mounted on high-end electronic products with reduced weight, so as to satisfy various requirements of high-end electronic products in terms of pixel and imaging quality. However, the conventional telescopic lens has the disadvantages of too long total length, too small aperture, poor imaging quality, and too large volume, and thus it is difficult to meet the requirements of high-specification electronic products. Therefore, it is one of the problems to be solved by the industry at present to provide an optical system having a telescopic characteristic and satisfying the requirement of high imaging quality.

Disclosure of Invention

The present invention provides an optical lens assembly for image formation, wherein the fourth lens element has negative refractive power. In addition, the image-side surface of the fourth lens element has at least one convex surface at the off-axis position, which suppresses a Chief Ray Angle (CRA) around the image, so that the photosensitive device can capture the image more clearly. When the specific conditions are met, the change of the peripheral shape of the second lens is favorably slowed down, and the generation of excessive stray light caused by the excessive bending of the surface shape of the second lens is avoided. In addition, the refractive powers of the second lens element and the fourth lens element are properly matched to avoid the excessive change of the shape of the second lens element. Further, it contributes to improvement of the telescopic characteristic of the optical lens group for imaging.

The invention provides an optical lens assembly for imaging, which sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side. The first lens element with positive refractive power has a convex object-side surface at paraxial region. The second lens element with negative refractive power has a concave object-side surface at paraxial region. The third lens element has a convex object-side surface at a paraxial region, and both object-side and image-side surfaces thereof are aspheric. The fourth lens element with negative refractive power has a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region, and has at least one convex image-side surface at an off-axis region, wherein the object-side surface and the image-side surface are aspheric. The fifth lens element with positive refractive power has an object-side surface and an image-side surface which are both aspheric. The total number of the lenses of the imaging optical lens group is five, and an air interval is arranged between every two adjacent lenses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on an optical axis. A radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, an abbe number of the fourth lens element is V4, an abbe number of the fifth lens element is V5, a focal length of the second lens element is f2, and a focal length of the fourth lens element is f4, which satisfy the following conditions:

(R3+R4)/(R3-R4)<0.50；

1.8< V4/V5< 3.5; and

f4/f2<1.0。

the present invention further provides an optical imaging lens assembly, sequentially including, from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface at paraxial region. The second lens element with negative refractive power has a concave object-side surface at paraxial region. The object-side surface and the image-side surface of the third lens element are aspheric. The fourth lens element with negative refractive power has a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region, and has at least one convex image-side surface at an off-axis region, wherein the object-side surface and the image-side surface are aspheric. The fifth lens element with positive refractive power has an object-side surface and an image-side surface which are both aspheric. The total number of the lenses of the imaging optical lens group is five, and an air interval is arranged between every two adjacent lenses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on an optical axis. A radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, an abbe number of the fourth lens element is V4, and an abbe number of the fifth lens element is V5, which satisfy the following conditions:

(R3+ R4)/(R3-R4) is less than or equal to-0.30; and

1.8<V4/V5<3.5。

the invention also provides an optical lens assembly for imaging, which comprises, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region. The second lens element with negative refractive power has a concave object-side surface at paraxial region. The object-side surface and the image-side surface of the third lens element are aspheric. The fourth lens element with negative refractive power has a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region, and has at least one convex image-side surface at an off-axis region, wherein the object-side surface and the image-side surface are aspheric. The fifth lens element with positive refractive power has an object-side surface and an image-side surface which are both aspheric. The total number of the lenses of the imaging optical lens group is five, and an air interval is arranged between every two adjacent lenses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on an optical axis. The curvature radius of the object side surface of the second lens is R3, the curvature radius of the image side surface of the second lens is R4, the maximum imaging height of the imaging optical lens group is ImgH, and the focal length of the imaging optical lens group is f, which satisfy the following conditions:

(R3+ R4)/(R3-R4) < 0.50; and

0.25<ImgH/f<0.55。

when the (R3+ R4)/(R3-R4) satisfies the above condition, it helps to alleviate the change of the peripheral shape of the second lens and avoid the generation of excessive stray light due to excessive curvature of the second lens surface.

When V4/V5 satisfies the above condition, it helps correct the color difference.

When f4/f2 satisfies the above condition, it is helpful to properly match the refractive powers of the second lens element and the fourth lens element to avoid the shape of the second lens element from being changed too much.

When ImgH/f satisfies the above condition, it contributes to improvement of the telephoto characteristic of the optical lens group for imaging.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

FIG. 1 is a schematic view of an image capturing apparatus according to a first embodiment of the present invention;

FIG. 2 is a graph showing the spherical aberration, astigmatism and distortion of the first embodiment in order from left to right;

FIG. 3 is a schematic view of an image capturing apparatus according to a second embodiment of the present invention;

FIG. 4 is a graph showing the spherical aberration, astigmatism and distortion of the second embodiment in order from left to right;

FIG. 5 is a schematic view of an image capturing apparatus according to a third embodiment of the present invention;

FIG. 6 is a graph showing the spherical aberration, astigmatism and distortion of the third embodiment from left to right;

FIG. 7 is a schematic view of an image capturing apparatus according to a fourth embodiment of the present invention;

FIG. 8 is a graph showing the spherical aberration, astigmatism and distortion of the fourth embodiment in order from left to right;

FIG. 9 is a schematic view of an image capturing apparatus according to a fifth embodiment of the present invention;

FIG. 10 is a graph showing the spherical aberration, astigmatism and distortion of the fifth embodiment in order from left to right;

FIG. 11 is a schematic view of an image capturing apparatus according to a sixth embodiment of the present invention;

FIG. 12 is a graph showing the spherical aberration, astigmatism and distortion of the sixth embodiment in order from left to right;

FIG. 13 is a schematic view of an image capturing apparatus according to a seventh embodiment of the invention;

FIG. 14 is a graph showing the spherical aberration, astigmatism and distortion in order from left to right for the seventh embodiment;

FIG. 15 is a schematic view of an image capturing apparatus according to an eighth embodiment of the present invention;

FIG. 16 is a graph showing the spherical aberration, astigmatism and distortion of the eighth embodiment in order from left to right;

FIG. 17 is a schematic view of an electronic device according to the present invention;

FIG. 18 is a schematic diagram of another electronic device according to the present invention;

FIG. 19 is a schematic diagram of yet another electronic device according to the present invention.

Wherein, the reference numbers:

an image taking device: 10

Aperture: 100. 200, 300, 400, 500, 600, 700, 800

A first lens: 110. 210, 310, 410, 510, 610, 710, 810

An object-side surface: 111. 211, 311, 411, 511, 611, 711, 811

Image-side surface: 112. 212, 312, 412, 512, 612, 712, 812

A second lens: 120. 220, 320, 420, 520, 620, 720, 820

An object-side surface: 121. 221, 321, 421, 521, 621, 721, 821

Image-side surface: 122. 222, 322, 422, 522, 622, 722, 822

A third lens: 130. 230, 330, 430, 530, 630, 730, 830

An object-side surface: 131. 231, 331, 431, 531, 631, 731, 831

Image-side surface: 132. 232, 332, 432, 532, 632, 732, 832

A fourth lens: 140. 240, 340, 440, 540, 640, 740, 840

An object-side surface: 141. 241, 341, 441, 541, 641, 741, 841

Image-side surface: 142. 242, 342, 442, 542, 642, 742, 842

A fifth lens: 150. 250, 350, 450, 550, 650, 750, 850

An object-side surface: 151. 251, 351, 451, 551, 651, 751, 851

Image-side surface: 152. 252, 352, 452, 552, 652, 752, 852

Infrared ray filtering filter element: 160. 260, 360, 460, 560, 660, 760, 860

Imaging surface: 170. 270, 370, 470, 570, 670, 770, 870

An electron-sensitive element: 180. 280, 380, 480, 580, 680, 780, 880

BL: the distance from the image side surface of the fifth lens element to the image plane on the optical axis

Fno: aperture value of imaging optical lens group

f: focal length of optical lens group for imaging

f 2: focal length of the second lens

f 3: focal length of the third lens

f 4: focal length of the fourth lens

HFOV: half of maximum viewing angle in optical lens group for imaging

ImgH: maximum imaging height of optical lens group for imaging

R3: radius of curvature of object-side surface of second lens

R4: radius of curvature of image-side surface of second lens

R7: radius of curvature of object-side surface of fourth lens

R8: radius of curvature of image-side surface of fourth lens

R10: radius of curvature of image-side surface of fifth lens

TL: the distance from the object side surface of the first lens element to the image plane on the optical axis

T12: the first lens and the second lens are spaced apart from each other on the optical axis

T23: the second lens and the third lens are spaced apart from each other on the optical axis

T34: the third lens and the fourth lens are separated by a distance on the optical axis

T45: the fourth lens and the fifth lens are separated by a distance on the optical axis

V1: abbe number of first lens

V2: abbe number of second lens

V3: abbe number of third lens

V4: abbe number of fourth lens

V5: abbe number of fifth lens

Detailed Description

The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:

the imaging optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Wherein, the total number of lenses in the optical lens group for imaging is five.

The optical axis of each two adjacent lenses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens has an air space, that is, the first lens, the second lens, the third lens, the fourth lens and the fifth lens can be five single non-bonded (non-adhesive) lenses. Since the process of the cemented lens is more complicated than that of the non-cemented lens, especially the cemented surface of the two lenses needs to have a curved surface with high accuracy so as to achieve high degree of conformity when the two lenses are cemented, and during the cementing process, the shift defect caused by the offset is more likely to affect the overall optical imaging quality. Therefore, the first lens element to the fifth lens element in the image capturing lens assembly can be configured by five single non-cemented lens elements, thereby effectively improving the problems caused by cemented lens elements.

The first lens element with positive refractive power has a convex object-side surface at paraxial region. Therefore, the optical lens assembly for imaging can provide enough positive refractive power, and is favorable for shortening the total length of the optical lens assembly for imaging.

The second lens element with negative refractive power has a concave object-side surface at paraxial region. Therefore, the aberration generated by the first lens can be corrected to improve the imaging quality.

The object-side surface of the third lens element can have at least one concave surface at an off-axis position, and the image-side surface of the third lens element can also have at least one concave surface at an off-axis position. Therefore, the angle of the light rays of the off-axis field of view incident on the photosensitive element can be suppressed, so that the receiving efficiency of the image photosensitive element is increased, and the aberration of the off-axis field of view is further corrected.

The fourth lens element with negative refractive power has a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region. This helps shorten the back focal length of the imaging optical lens group. In addition, the image side surface of the fourth lens element has at least one convex surface at the off-axis position, which can suppress the angle of the chief ray at the periphery of the image, so that the photosensitive element can more clearly capture the image.

The fifth lens element with positive refractive power has an object-side surface being convex at a paraxial region and an image-side surface being convex at a paraxial region. Therefore, the aberration generated by the first lens element to the fourth lens element due to over-strong refractive power can be corrected.

A radius of curvature of the object-side surface of the second lens element is R3, and a radius of curvature of the image-side surface of the second lens element is R4, which satisfy the following conditions: (R3+ R4)/(R3-R4) < 0.50. Therefore, the change of the peripheral shape of the second lens is favorably slowed down, and the generation of excessive stray light caused by the excessive bending of the surface shape of the second lens is avoided. Preferably, it may further satisfy the following condition: (R3+ R4)/(R3-R4) <0. More preferably, it may further satisfy the following conditions: -2.5< (R3+ R4)/(R3-R4) <0.

The focal length of the imaging optical lens group is f, the curvature radius of the image side surface of the fifth lens is R10, and the following conditions are satisfied: f/| R10| < 1.20. Therefore, the optical lens group for imaging is beneficial to providing a proper back focal length, and the situation that the back focal length is too long or too short due to the excessive bending of the surface shape of the fifth lens is avoided. In detail, when the image-side surface of the fifth lens element is convex at a paraxial region, the above condition can prevent the back focal length from being excessively elongated. When the image-side surface of the fifth lens element is concave at a paraxial region, the above condition can prevent the back focal length from being excessively shortened. Preferably, it may further satisfy the following condition: f/| R10| < 0.75.

The maximum imaging height (namely half of the total diagonal length of the effective sensing area of the electronic photosensitive element) of the imaging optical lens group is ImgH, the focal length of the imaging optical lens group is f, and the following conditions are satisfied: 0.25< ImgH/f < 0.55. This contributes to improvement of the telescopic characteristic of the optical lens group for imaging.

The distance between the first lens and the second lens on the optical axis is T12, the distance between the second lens and the third lens on the optical axis is T23, the distance between the third lens and the fourth lens on the optical axis is T34, and the distance between the fourth lens and the fifth lens on the optical axis is T45, which satisfies the following conditions: 1.0< T34/(T12+ T23+ T45) < 4.0. Therefore, the distance between every two adjacent lenses is favorably distributed to reduce the sensitivity of the imaging optical lens group, and the imaging optical lens group has a telescopic function.

The focal length of the second lens is f2, and the focal length of the fourth lens is f4, which satisfies the following conditions: f4/f2< 1.0. Therefore, the refractive power of the second lens element and the refractive power of the fourth lens element are properly matched, so that the second lens element is prevented from changing too much in shape.

The first lens has an abbe number of V1, the second lens has an abbe number of V2, the third lens has an abbe number of V3, the fourth lens has an abbe number of V4, and the fifth lens has an abbe number of V5, which satisfy the following conditions: 0.45< (V2+ V3+ V5)/(V1+ V4) < 0.75. Thereby, a good balance can be obtained between the chromatic aberration correction and the astigmatism correction.

The distance between the third lens element and the fourth lens element on the optical axis is T34, and the distance between the image-side surface of the fifth lens element and an imaging plane on the optical axis is BL, which satisfies the following conditions: 1.20< T34/BL < 2.5. Therefore, the distribution and the change of the image chief ray angle can be controlled, and the receiving efficiency of the image photosensitive element is effectively improved.

A radius of curvature of the object-side surface of the fourth lens element is R7, and a radius of curvature of the image-side surface of the fourth lens element is R8, wherein the following conditions are satisfied: -1.0< R7/R8< 0. Therefore, the curvature radius of the object side surface and the image side surface of the fourth lens is beneficial to further shortening the back focal length of the optical lens group for imaging.

The distance TL from the object-side surface of the first lens element to the image plane on the optical axis and the focal length f of the imaging optical lens assembly satisfy the following conditions: 0.75< TL/f < 1.10. Therefore, the total length of the optical lens group for imaging can be shortened, and the optical lens group for imaging has the telescopic characteristic.

The focal length of the imaging optical lens group is f, the focal length of the second lens is f2, the focal length of the third lens is f3, and the focal length of the fourth lens is f4, which can satisfy the following conditions: -4.0< (f/f2) + (f/f3) + (f/f4) < -2.0. Therefore, the image curvature caused by the first lens is corrected.

The first lens and the second lens are separated by a distance T12 on the optical axis, and the second lens and the third lens are separated by a distance T23 on the optical axis, which satisfies the following conditions: 0< T23/T12< 1.75. Therefore, the short interval between the first lens and the second lens can be avoided, and the assembly difficulty is reduced to improve the assembly qualified rate.

The fourth lens has an abbe number of V4 and the fifth lens has an abbe number of V5, which satisfy the following conditions: 1.8< V4/V5< 3.5. Therefore, the color difference is corrected.

The focal length of the imaging optical lens group is f, the focal length of the third lens is f3, and the following conditions can be satisfied: -1.2< f/f3 ≦ 0. Therefore, the aberration correction effect can be effectively enhanced, and the imaging quality is improved.

In the imaging optical lens assembly disclosed in the present invention, the aperture may be configured as a front aperture or a middle aperture. The front diaphragm means that the diaphragm is arranged between the object to be shot and the first lens, and the middle diaphragm means that the diaphragm is arranged between the first lens and the imaging surface. If the diaphragm is a front diaphragm, the Exit Pupil (Exit Pupil) of the optical lens group for imaging and the imaging surface can generate a longer distance, so that the optical lens group for imaging has a Telecentric (telecentricity) effect, and the efficiency of receiving images by a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor) of the electronic photosensitive element can be increased; the intermediate diaphragm is advantageous in enlarging the field angle of the imaging optical lens group, and thus the imaging optical lens group has an advantage of a wide-angle lens.

In the imaging optical lens assembly disclosed in the present invention, the lens material may be plastic or glass. When the lens is made of glass, the degree of freedom of the refractive power configuration can be increased. In addition, when the lens is made of plastic, the production cost can be effectively reduced. In addition, an Aspheric Surface (ASP) can be arranged on the surface of the lens, the ASP can be easily made into shapes other than a spherical surface, more control variables are obtained for reducing the aberration, and the number of the lenses required to be used is further reduced, so that the total length of the optical lens assembly for imaging can be effectively reduced.

In the optical lens assembly for imaging disclosed in the present invention, if the lens surface is a convex surface and the position of the convex surface is not defined, it means that the convex surface can be located at a position close to the optical axis of the lens surface; if the lens surface is concave and the position of the concave surface is not defined, it means that the concave surface can be located at the position of the lens surface near the optical axis. If the refractive power or focal length of the lens element does not define the position of the lens region, it means that the refractive power or focal length of the lens element can be the refractive power or focal length of the lens element at the paraxial region.

In the imaging optical lens assembly disclosed in the present invention, the imaging surface of the imaging optical lens assembly may be a plane or a curved surface with any curvature, especially a curved surface with a concave surface facing the object side, depending on the corresponding electronic photosensitive element.

The optical lens assembly for imaging disclosed in the present invention may be disposed with at least one Stop, and the Stop may be disposed in front of the first lens, between the lenses or behind the last lens, and the Stop may be a flare Stop (Glare Stop) or a Field Stop (Field Stop), for reducing stray light and improving image quality.

The present invention further provides an image capturing device, which includes the aforementioned optical lens assembly for imaging and an electronic photosensitive element, wherein the electronic photosensitive element is disposed on an imaging surface of the optical lens assembly for imaging. Preferably, the image capturing device may further include a lens barrel, a Holder Member (Holder Member), or a combination thereof.

Referring to fig. 17, 18 and 19, the image capturing apparatus 10 can be applied to a smart phone (as shown in fig. 17), a tablet computer (as shown in fig. 18), a wearable apparatus (as shown in fig. 19), and the like in many ways. Preferably, the electronic device may further include a control unit, a display unit, a storage unit, a Random Access Memory (RAM), or a combination thereof.

The imaging optical lens group can be applied to a moving focusing optical system according to requirements, and has the characteristics of excellent aberration correction and good imaging quality. The invention can also be applied to electronic devices such as three-dimensional (3D) image acquisition, digital cameras, mobile devices, tablet computers, smart televisions, network monitoring equipment, driving recorders, backing developing devices, motion sensing game machines, wearable devices and the like in many aspects. The electronic device disclosed in the foregoing is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the image capturing device of the present invention.

The following provides a detailed description of the embodiments with reference to the accompanying drawings.

< first embodiment >

Referring to fig. 1 and fig. 2, wherein fig. 1 is a schematic view of an image capturing device according to a first embodiment of the invention, and fig. 2 is a graph of spherical aberration, astigmatism and distortion in the first embodiment from left to right. As shown in fig. 1, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 180. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 100, a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150, an infrared-cut Filter (IR-cut Filter)160, and an image plane 170. The electronic photosensitive element 180 is disposed on the imaging surface 170. The lenses (110-150) of the optical lens group for imaging are five. An air space is formed between two adjacent lenses of the first lens element 110, the second lens element 120, the third lens element 130, the fourth lens element 140 and the fifth lens element 150 on the optical axis.

The first lens element 110 with positive refractive power has a convex object-side surface 111 at a paraxial region and a concave image-side surface 112 at a paraxial region, and is made of plastic material.

The second lens element 120 with negative refractive power has a concave object-side surface 121 at a paraxial region and a convex image-side surface 122 at a paraxial region, and is made of plastic material.

The third lens element 130 is made of plastic material, and has an object-side surface 131 being a flat surface at a paraxial region and an image-side surface 132 being a flat surface at a paraxial region, wherein both surfaces are aspheric, the object-side surface 131 has at least one concave surface at an off-axis region, and the image-side surface 132 has at least one concave surface at an off-axis region.

The fourth lens element 140 with negative refractive power has a concave object-side surface 141 at a paraxial region and a concave image-side surface 142 at a paraxial region, and both surfaces are aspheric, and the image-side surface 142 has at least one convex surface at an off-axis region.

The fifth lens element 150 with positive refractive power has a convex object-side surface 151 at a paraxial region and a planar image-side surface 152 at a paraxial region, and is made of plastic material.

The ir-cut filter 160 is made of glass, and is disposed between the fifth lens element 150 and the image plane 170, and does not affect the focal length of the optical image capturing lens assembly.

The curve equation of the aspherical surface of each lens described above is as follows:

；

wherein:

x: the distance between a point on the aspheric surface, which is Y away from the optical axis, and the relative distance between the point and a tangent plane tangent to the intersection point on the aspheric surface optical axis;

y: the perpendicular distance between a point on the aspheric curve and the optical axis;

r: a radius of curvature;

k: the cone coefficient; and

ai: the ith order aspheric coefficients.

In the optical lens group for image formation of the first embodiment, the focal length of the optical lens group for image formation is F, the aperture value (F-number) of the optical lens group for image formation is Fno, and half of the maximum angle of view in the optical lens group for image formation is HFOV, and the numerical values thereof are as follows: f 6.29 millimeters (mm), Fno 3.00, HFOV 24.9 degrees (deg.).

The abbe number of the first lens 110 is V1, the abbe number of the second lens 120 is V2, the abbe number of the third lens 130 is V3, the abbe number of the fourth lens 140 is V4, and the abbe number of the fifth lens 150 is V5, which satisfy the following conditions: (V2+ V3+ V5)/(V1+ V4) ═ 0.54.

The fourth lens 140 has an abbe number of V4 and the fifth lens 150 has an abbe number of V5, which satisfy the following conditions: V4/V5 is 2.75.

The distance between the first lens 110 and the second lens 120 on the optical axis is T12, and the distance between the second lens 120 and the third lens 130 on the optical axis is T23, which satisfies the following conditions: T23/T12 is 0.32.

The distance between the first lens 110 and the second lens 120 on the optical axis is T12, the distance between the second lens 120 and the third lens 130 on the optical axis is T23, the distance between the third lens 130 and the fourth lens 140 on the optical axis is T34, and the distance between the fourth lens 140 and the fifth lens 150 on the optical axis is T45, which satisfies the following conditions: T34/(T12+ T23+ T45) is 2.73.

An axial distance between the third lens element 130 and the fourth lens element 140 is T34, and an axial distance between the image-side surface 152 of the fifth lens element and the image plane 170 is BL, which satisfy the following conditions: T34/BL is 1.84.

An axial distance TL from the object-side surface 111 of the first lens element to the image plane 170 is, a focal length f of the imaging optical lens assembly satisfies the following conditions: TL/f is 0.89.

The maximum imaging height of the imaging optical lens group is ImgH, the focal length of the imaging optical lens group is f, and the following conditions are satisfied: ImgH/f is 0.47.

A radius of curvature of the second lens object-side surface 121 is R3, and a radius of curvature of the second lens image-side surface 122 is R4, which satisfy the following conditions: (R3+ R4)/(R3-R4) — 1.15.

A radius of curvature of the fourth lens object-side surface 141 is R7, and a radius of curvature of the fourth lens image-side surface 142 is R8, which satisfy the following conditions: R7/R8 ═ 0.06.

The focal length of the imaging optical lens group is f, and the curvature radius of the image side surface 152 of the fifth lens is R10, which satisfies the following conditions: f/| R10| ═ 0.

The focal length of the imaging optical lens group is f, the focal length of the second lens 120 is f2, the focal length of the third lens 130 is f3, and the focal length of the fourth lens 140 is f4, which satisfies the following conditions: (f/f2) + (f/f3) + (f/f4) — 2.55.

The focal length of the imaging optical lens group is f, the focal length of the third lens 130 is f3, and the following conditions are satisfied: f/f3 is 0.

The focal length of the second lens 120 is f2, and the focal length of the fourth lens 140 is f4, which satisfies the following conditions: f4/f2 is 0.80.

The following table one and table two are referred to cooperatively.

The first embodiment shows detailed structural data of the first embodiment in fig. 1, wherein the unit of the radius of curvature, the thickness and the focal length is millimeters (mm), and the surfaces 0 to 14 sequentially represent the surfaces from the object side to the image side. Table two shows the aspheric data of the first embodiment, where k is the cone coefficient in the aspheric curve equation, and a4 to a16 represent the 4 th to 16 th order aspheric coefficients of each surface. In addition, the following tables of the embodiments correspond to the schematic diagrams and aberration graphs of the embodiments, and the definitions of the data in the tables are the same as those of the first and second tables of the first embodiment, which will not be described herein.

< second embodiment >

Referring to fig. 3 and fig. 4, wherein fig. 3 is a schematic view of an image capturing apparatus according to a second embodiment of the invention, and fig. 4 is a graph of spherical aberration, astigmatism and distortion of the second embodiment in order from left to right. As shown in fig. 3, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 280. The imaging optical lens assembly includes, in order from an object side to an image side, a first lens element 210, an aperture stop 200, a second lens element 220, a third lens element 230, a fourth lens element 240, a fifth lens element 250, an ir-cut filter 260 and an image plane 270. The electronic photosensitive element 280 is disposed on the image plane 270. The lenses (210) and (250) of the optical lens group for imaging are five pieces. Each of the first lens element 210, the second lens element 220, the third lens element 230, the fourth lens element 240, and the fifth lens element 250 has an air gap therebetween on the optical axis.

The first lens element 210 with positive refractive power has a convex object-side surface 211 at a paraxial region and a convex image-side surface 212 at a paraxial region, and is made of plastic material.

The second lens element 220 with negative refractive power has a concave object-side surface 221 at a paraxial region and a planar image-side surface 222 at a paraxial region, and is made of plastic material.

The third lens element 230 with negative refractive power has a concave object-side surface 231 at a paraxial region and a convex image-side surface 232 at a paraxial region, and is made of plastic material, wherein both surfaces are aspheric, the object-side surface 231 has at least one concave surface at an off-axis region and the image-side surface 232 has at least one concave surface at an off-axis region.

The fourth lens element 240 with negative refractive power has a concave object-side surface 241 in a paraxial region thereof and a concave image-side surface 242 in a paraxial region thereof, both surfaces being aspheric, and the image-side surface 242 has at least one convex surface in an off-axis region thereof.

The fifth lens element 250 with positive refractive power has a convex object-side surface 251 and a concave image-side surface 252 at a paraxial region, and is made of plastic material.

The ir-cut filter 260 is made of glass, and is disposed between the fifth lens element 250 and the image plane 270, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to table three and table four below.

In the second embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< third embodiment >

Referring to fig. 5 and fig. 6, wherein fig. 5 is a schematic view of an image capturing apparatus according to a third embodiment of the invention, and fig. 6 is a graph showing spherical aberration, astigmatism and distortion in order from left to right in the third embodiment. As shown in fig. 5, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 380. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 300, a first lens element 310, a second lens element 320, a third lens element 330, a fourth lens element 340, a fifth lens element 350, an ir-cut filter element 360 and an image plane 370. The electron sensor 380 is disposed on the image plane 370. The lenses (310 and 350) of the optical lens group for imaging are five pieces. An air space is formed between each two adjacent lenses of the first lens element 310, the second lens element 320, the third lens element 330, the fourth lens element 340 and the fifth lens element 350.

The first lens element 310 with positive refractive power has a convex object-side surface 311 at a paraxial region and a concave image-side surface 312 at a paraxial region, and is made of plastic material.

The second lens element 320 with negative refractive power has a concave object-side surface 321 at a paraxial region and a concave image-side surface 322 at a paraxial region, and is made of plastic material.

The third lens element 330 with negative refractive power has a convex object-side surface 331 at a paraxial region and a concave image-side surface 332 at a paraxial region, and is made of plastic material, wherein both surfaces are aspheric, the object-side surface 331 has at least one concave surface at an off-axis region and the image-side surface 332 has at least one concave surface at an off-axis region.

The fourth lens element 340 with negative refractive power has a concave object-side surface 341 in a paraxial region thereof and a concave image-side surface 342 in a paraxial region thereof, and both surfaces are aspheric, and the image-side surface 342 is convex in an off-axis region thereof.

The fifth lens element 350 with positive refractive power has a convex object-side surface 351 at a paraxial region and a concave image-side surface 352 at a paraxial region, and is made of plastic material.

The ir-cut filter 360 is made of glass, and is disposed between the fifth lens element 350 and the image plane 370, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to table five and table six below in combination.

In the third embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< fourth embodiment >

Referring to fig. 7 and 8, wherein fig. 7 is a schematic view of an image capturing apparatus according to a fourth embodiment of the invention, and fig. 8 is a graph showing spherical aberration, astigmatism and distortion in the fourth embodiment from left to right. As shown in fig. 7, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 480. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 400, a first lens element 410, a second lens element 420, a third lens element 430, a fourth lens element 440, a fifth lens element 450, an ir-cut filter element 460 and an image plane 470. The electron sensor 480 is disposed on the image plane 470. The lenses (410-450) of the optical lens group for imaging are five pieces. Each of the first lens element 410, the second lens element 420, the third lens element 430, the fourth lens element 440, and the fifth lens element 450 has an air gap between two adjacent lens elements on the optical axis.

The first lens element 410 with positive refractive power has a convex object-side surface 411 at a paraxial region and a concave image-side surface 412 at a paraxial region, and is made of plastic material.

The second lens element 420 with negative refractive power has a concave object-side surface 421 at a paraxial region and a convex image-side surface 422 at a paraxial region, and is made of plastic material.

The third lens element 430 with negative refractive power has a concave object-side surface 431 at a paraxial region and a concave image-side surface 432 at a paraxial region, and is made of plastic material, wherein both surfaces are aspheric, the object-side surface 431 has at least one concave surface at an off-axis region, and the image-side surface 432 has at least one concave surface at an off-axis region.

The fourth lens element 440 with negative refractive power has a concave object-side surface 441 at a paraxial region and a concave image-side surface 442 at a paraxial region, and both surfaces are aspheric, and the image-side surface 442 has at least one convex surface at an off-axis region.

The fifth lens element 450 with positive refractive power has a convex object-side surface 451 at a paraxial region and a convex image-side surface 452 at a paraxial region, and is made of plastic material.

The ir-cut filter 460 is made of glass, and is disposed between the fifth lens element 450 and the image plane 470, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to table seven and table eight below in combination.

In the fourth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< fifth embodiment >

Referring to fig. 9 and 10, fig. 9 is a schematic view of an image capturing apparatus according to a fifth embodiment of the invention, and fig. 10 is a graph showing spherical aberration, astigmatism and distortion in the fifth embodiment from left to right. As shown in fig. 9, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 580. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 500, a first lens element 510, a second lens element 520, a third lens element 530, a fourth lens element 540, a fifth lens element 550, an ir-cut filter 560 and an image plane 570. The electron sensor 580 is disposed on the image plane 570. The lenses (510) and 550) of the optical lens group for imaging are five pieces. An air space is formed between each two adjacent lenses of the first lens 510, the second lens 520, the third lens 530, the fourth lens 540 and the fifth lens 550 on the optical axis.

The first lens element 510 with positive refractive power has a convex object-side surface 511 at a paraxial region and a convex image-side surface 512 at a paraxial region, and is made of plastic material.

The second lens element 520 with negative refractive power has a concave object-side surface 521 at a paraxial region and a concave image-side surface 522 at a paraxial region, and is made of plastic material.

The third lens element 530 with negative refractive power has a convex object-side surface 531 at a paraxial region and a concave image-side surface 532 at a paraxial region, and is aspheric, and the object-side surface 531 has at least one concave surface at an off-axis region and the image-side surface 532 has at least one concave surface at an off-axis region.

The fourth lens element 540 with negative refractive power has a concave object-side surface 541 at a paraxial region and a concave image-side surface 542 at a paraxial region, both surfaces being aspheric, and the image-side surface 542 has at least one convex surface at an off-axis region.

The fifth lens element 550 with positive refractive power has a convex object-side surface 551 at a paraxial region and a concave image-side surface 552 at a paraxial region, and is made of plastic material.

The ir-cut filter 560 is made of glass, and is disposed between the fifth lens element 550 and the image plane 570 without affecting the focal length of the optical image capturing lens assembly.

Please refer to table nine and table ten below in combination.

In the fifth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< sixth embodiment >

Referring to fig. 11 and 12, wherein fig. 11 is a schematic view of an image capturing apparatus according to a sixth embodiment of the invention, and fig. 12 is a graph showing spherical aberration, astigmatism and distortion in the sixth embodiment from left to right. As shown in fig. 11, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 680. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 600, a first lens element 610, a second lens element 620, a third lens element 630, a fourth lens element 640, a fifth lens element 650, an ir-cut filter 660 and an image plane 670. The electrophotographic photosensitive member 680 is disposed on the image plane 670. The lenses (610-650) of the optical lens group for imaging are five pieces. An air space is formed between each two adjacent lenses of the first lens 610, the second lens 620, the third lens 630, the fourth lens 640 and the fifth lens 650.

The first lens element 610 with positive refractive power has a convex object-side surface 611 at a paraxial region and a concave image-side surface 612 at a paraxial region, and is made of plastic material.

The second lens element 620 with negative refractive power has a concave object-side surface 621 at a paraxial region and a convex image-side surface 622 at a paraxial region, and is made of plastic material.

The third lens element 630 with negative refractive power has a concave object-side surface 631 at a paraxial region and a convex image-side surface 632 at a paraxial region, and is made of plastic material, wherein both surfaces are aspheric, the object-side surface 631 has at least one concave surface at an off-axis region, and the image-side surface 632 has at least one concave surface at an off-axis region.

The fourth lens element 640 with negative refractive power has a concave object-side surface 641 at a paraxial region and a concave image-side surface 642 at a paraxial region, both surfaces being aspheric, and the image-side surface 642 has at least one convex surface at an off-axis region.

The fifth lens element 650 with positive refractive power has a concave object-side surface 651 at a paraxial region and a convex image-side surface 652 at a paraxial region, and is made of plastic material.

The ir-cut filter 660 is made of glass, and is disposed between the fifth lens element 650 and the image plane 670, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to the following table eleven and table twelve.

In the sixth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< seventh embodiment >

Referring to fig. 13 and 14, wherein fig. 13 is a schematic view of an image capturing apparatus according to a seventh embodiment of the invention, and fig. 14 is a graph showing spherical aberration, astigmatism and distortion in the seventh embodiment from left to right. As shown in fig. 13, the image capturing device includes an optical lens assembly (not labeled) for image formation and an electronic photosensitive element 780. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 700, a first lens element 710, a second lens element 720, a third lens element 730, a fourth lens element 740, a fifth lens element 750, an ir-cut filter element 760 and an image plane 770. The electronic photosensitive element 780 is disposed on the imaging surface 770. The lenses (710 and 750) of the optical lens group for imaging are five pieces. An air space is formed between each two adjacent lenses of the first lens 710, the second lens 720, the third lens 730, the fourth lens 740 and the fifth lens 750 on the optical axis.

The first lens element 710 with positive refractive power has a convex object-side surface 711 at a paraxial region and a convex image-side surface 712 at a paraxial region, and is made of plastic material.

The second lens element 720 with negative refractive power has a concave object-side surface 721 at a paraxial region and a concave image-side surface 722 at a paraxial region, and is made of plastic material.

The third lens element 730 with positive refractive power has a concave object-side surface 731 in a paraxial region thereof and a convex image-side surface 732 in a paraxial region thereof, and is made of plastic material, wherein both surfaces are aspheric, the object-side surface 731 has at least one concave surface in an off-axis region thereof, and the image-side surface 732 has at least one concave surface in an off-axis region thereof.

The fourth lens element 740 with negative refractive power has a concave object-side surface 741 in a paraxial region thereof and a concave image-side surface 742 in a paraxial region thereof, and both surfaces are aspheric, and the image-side surface 742 has at least one convex surface in an off-axis region thereof.

The fifth lens element 750 with positive refractive power has a convex object-side surface 751 at a paraxial region and a concave image-side surface 752 at a paraxial region, and is made of plastic material.

The ir-cut filter 760 is made of glass, and disposed between the fifth lens element 750 and the image plane 770, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to the following thirteen tables and fourteen tables.

In the seventh embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

< eighth embodiment >

Referring to fig. 15 and 16, wherein fig. 15 is a schematic view of an image capturing apparatus according to an eighth embodiment of the present invention, and fig. 16 is a graph showing spherical aberration, astigmatism and distortion in the eighth embodiment from left to right. As shown in fig. 15, the image capturing device includes an optical lens assembly (not shown) for image formation and an electronic photosensitive element 880. The imaging optical lens assembly includes, in order from an object side to an image side, an aperture stop 800, a first lens element 810, a second lens element 820, a third lens element 830, a fourth lens element 840, a fifth lens element 850, an ir-cut filter 860 and an image plane 870. The electronic photosensitive element 880 is disposed on the image plane 870. The lenses (810 and 850) of the optical lens group for imaging are five pieces. An air space is formed between each two adjacent lenses of the first lens 810, the second lens 820, the third lens 830, the fourth lens 840 and the fifth lens 850.

The first lens element 810 with positive refractive power has a convex object-side surface 811 at a paraxial region and a convex image-side surface 812 at a paraxial region, and is made of plastic material.

The second lens element 820 with negative refractive power has a concave object-side surface 821 at a paraxial region and a concave image-side surface 822 at a paraxial region, and is made of plastic material.

The third lens element 830 with negative refractive power has a concave object-side surface 831 at a paraxial region and a convex image-side surface 832 at a paraxial region, and is aspheric, and the object-side surface 831 has at least one concave surface at an off-axis region and the image-side surface 832 has at least one concave surface at an off-axis region.

The fourth lens element 840 with negative refractive power has a concave object-side surface 841 at a paraxial region and a concave image-side surface 842 at a paraxial region, which are both aspheric, and the image-side surface 842 has at least one convex surface at an off-axis region.

The fifth lens element 850 with positive refractive power has a convex object-side surface 851 at a paraxial region and a concave image-side surface 852 at a paraxial region, and is made of plastic material.

The ir-cut filter 860 is made of glass, and is disposed between the fifth lens element 850 and the image plane 870, and does not affect the focal length of the optical image capturing lens assembly.

Please refer to table fifteen and table sixteen below.

In the eighth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the definitions described in the following table are the same as those in the first embodiment, and are not repeated herein.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An optical imaging lens assembly, in order from an object side to an image side, comprising:

a first lens element with positive refractive power having a convex object-side surface at paraxial region;

a second lens element with negative refractive power having a concave object-side surface at paraxial region;

a third lens element with a convex object-side surface at a paraxial region and aspheric object-side and image-side surfaces;

a fourth lens element with negative refractive power having a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region, the image-side surface of the fourth lens element having at least one convex surface at an off-axis region, wherein the object-side surface and the image-side surface are aspheric; and

a fifth lens element with positive refractive power having an object-side surface and an image-side surface which are aspheric;

the total number of the lenses of the imaging optical lens group is five, and an air space is arranged between each two adjacent lenses of the first lens, the second lens, the third lens, the fourth lens and the fifth lens on an optical axis;

wherein a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, an abbe number of the fourth lens element is V4, an abbe number of the fifth lens element is V5, a focal length of the second lens element is f2, and a focal length of the fourth lens element is f4, and the following conditions are satisfied:

(R3+R4)/(R3-R4)<0.50；

1.8< V4/V5< 3.5; and

f4/f2<1.0。

2. the optical lens assembly as claimed in claim 1, wherein the first lens element and the second lens element are separated by a distance T12, the second lens element and the third lens element are separated by a distance T23, the third lens element and the fourth lens element are separated by a distance T34, and the fourth lens element and the fifth lens element are separated by a distance T45, which satisfies the following conditions:

1.0<T34/(T12+T23+T45)<4.0。

3. the imaging optical lens assembly according to claim 1, wherein the first lens element has an abbe number of V1, the second lens element has an abbe number of V2, the third lens element has an abbe number of V3, the fourth lens element has an abbe number of V4, and the fifth lens element has an abbe number of V5, which satisfy the following conditions:

0.45<(V2+V3+V5)/(V1+V4)<0.75。

4. the optical lens assembly for image formation according to claim 1, wherein a focal length of the optical lens assembly for image formation is f, and a radius of curvature of the image-side surface of the fifth lens element is R10, which satisfy the following conditions:

f/|R10|<1.20。

5. an optical lens assembly according to claim 1, wherein a radius of curvature of the object-side surface of the second lens element is R3, and a radius of curvature of the image-side surface of the second lens element is R4, wherein:

(R3+R4)/(R3-R4)<0。

6. the imaging optical lens group according to claim 1, wherein a maximum imaging height of the imaging optical lens group is ImgH, and a focal length of the imaging optical lens group is f, which satisfy the following conditions:

0.25<ImgH/f<0.55。

7. an optical lens assembly according to claim 1, wherein the distance TL from the object-side surface of the first lens element to an imaging plane on the optical axis is shorter than f, and the focal length of the optical lens assembly satisfies the following condition:

0.75<TL/f<1.10。

8. the optical lens assembly as claimed in claim 1, wherein the third lens element and the fourth lens element are separated by a distance T34 along the optical axis, and the distance BL along the optical axis from the image-side surface of the fifth lens element to an image-forming surface satisfies the following conditions:

1.20<T34/BL<2.5。

9. the optical lens assembly for image formation according to claim 1, wherein the focal length of the optical lens assembly for image formation is f, the focal length of the second lens is f2, the focal length of the third lens is f3, and the focal length of the fourth lens is f4, which satisfies the following conditions:

-4.0<(f/f2)+(f/f3)+(f/f4)<-2.0。

10. an optical lens assembly for imaging as claimed in claim 1, wherein the first lens and the second lens are separated by a distance T12 on the optical axis, and the second lens and the third lens are separated by a distance T23 on the optical axis, which satisfies the following conditions:

0<T23/T12<1.75。

11. an optical lens assembly as recited in claim 1, wherein an object-side surface of said fifth lens element is convex at a paraxial region.

12. The imaging optical lens assembly of claim 1, wherein the image-side surface of the fifth lens element is concave at a paraxial region.

13. The imaging optical lens assembly of claim 1, wherein the image-side surface of the third lens element is concave at a paraxial region.

14. An optical imaging lens assembly, in order from an object side to an image side, comprising:

a third lens element, both object-side and image-side surfaces of which are aspheric;

wherein a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, an abbe number of the fourth lens element is V4, and an abbe number of the fifth lens element is V5, and the following conditions are satisfied:

(R3+ R4)/(R3-R4) is less than or equal to-0.30; and

1.8<V4/V5<3.5。

15. the optical lens assembly for image formation according to claim 14, wherein a focal length of the optical lens assembly for image formation is f, and a radius of curvature of the image-side surface of the fifth lens element is R10, which satisfy the following conditions:

f/|R10|<1.20。

16. an optical lens assembly for imaging as claimed in claim 14, wherein a distance between the first lens element and the second lens element on the optical axis is T12, a distance between the second lens element and the third lens element on the optical axis is T23, a distance between the third lens element and the fourth lens element on the optical axis is T34, and a distance between the fourth lens element and the fifth lens element on the optical axis is T45, wherein the following conditions are satisfied:

1.0<T34/(T12+T23+T45)<4.0。

17. an optical lens assembly for imaging as claimed in claim 14, wherein a distance between the first lens element and the second lens element on the optical axis is T12, and a distance between the second lens element and the third lens element on the optical axis is T23, wherein the following conditions are satisfied:

0<T23/T12<1.75。

18. the imaging optical lens group according to claim 14, wherein the focal length of the imaging optical lens group is f, the focal length of the second lens is f2, the focal length of the third lens is f3, and the focal length of the fourth lens is f4, which satisfies the following conditions:

-4.0<(f/f2)+(f/f3)+(f/f4)<-2.0。

19. an optical lens group for image formation according to claim 14, wherein the maximum image formation height of the optical lens group for image formation is ImgH and the focal length of the optical lens group for image formation is f, which satisfy the following conditions:

0.25<ImgH/f<0.55。

20. an optical imaging lens assembly as claimed in claim 14, wherein the distance between the object-side surface of the first lens element and an imaging plane on the optical axis is TL, and the focal length of the optical imaging lens assembly is f, which satisfies the following condition:

0.75<TL/f<1.10。

21. an optical lens assembly for imaging as claimed in claim 14, wherein a distance between the third lens element and the fourth lens element on an optical axis is T34, and a distance between an image side surface of the fifth lens element and an imaging surface on the optical axis is BL, wherein the following conditions are satisfied:

1.20<T34/BL<2.5。

22. an optical imaging lens assembly, in order from an object side to an image side, comprising:

a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface at a paraxial region;

wherein a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, a maximum image height of the optical lens assembly for imaging is ImgH, and a focal length of the optical lens assembly for imaging is f, which satisfy the following conditions:

(R3+ R4)/(R3-R4) < 0.50; and

0.25<ImgH/f<0.55。

23. an optical imaging lens assembly as claimed in claim 22, wherein the distance between the object-side surface of the first lens element and an imaging plane on the optical axis is TL, and the focal length of the optical imaging lens assembly is f, which satisfies the following condition:

0.75<TL/f<1.10。

24. an optical lens assembly for imaging as claimed in claim 22, wherein a distance between the first lens element and the second lens element on the optical axis is T12, a distance between the second lens element and the third lens element on the optical axis is T23, a distance between the third lens element and the fourth lens element on the optical axis is T34, and a distance between the fourth lens element and the fifth lens element on the optical axis is T45, wherein the following conditions are satisfied:

1.0<T34/(T12+T23+T45)<4.0。

25. an optical lens unit for imaging as claimed in claim 22, wherein an abbe number of the fourth lens element is V4, an abbe number of the fifth lens element is V5, and the following conditions are satisfied:

1.8<V4/V5<3.5。

26. an optical lens unit for imaging as claimed in claim 22, wherein 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, and an abbe number of the fifth lens element is V5, and the following conditions are satisfied:

0.45<(V2+V3+V5)/(V1+V4)<0.75。

27. an optical lens assembly for imaging as claimed in claim 22, wherein the first lens element and the second lens element are separated by a distance T12 on the optical axis, and the second lens element and the third lens element are separated by a distance T23 on the optical axis, which satisfies the following conditions:

0<T23/T12<1.75。