CN214278525U

CN214278525U - Optical imaging system

Info

Publication number: CN214278525U
Application number: CN202021285111.9U
Authority: CN
Inventors: 张永明; 赖建勋; 刘燿维
Original assignee: Ability Opto Electronics Technology Co Ltd
Current assignee: Ability Opto Electronics Technology Co Ltd
Priority date: 2020-04-20
Filing date: 2020-07-03
Publication date: 2021-09-24
Anticipated expiration: 2030-07-03
Also published as: TWM598956U

Abstract

The utility model provides an optical imaging system contains first lens, second lens, third lens and fourth lens by thing side to picture side in proper order. The first lens element with positive refractive power has a convex object-side surface. The second lens element to the third lens element have refractive power, and both surfaces of the lens elements may be aspheric. The fourth lens element with negative refractive power has a concave image-side surface, wherein both surfaces of the fourth lens element are aspheric, and at least one surface of the fourth lens element has an inflection point. The lens elements with refractive power in the optical imaging system are the first lens element to the fourth lens element. When the specific conditions are met, the optical imaging device can have larger light receiving capacity and better optical path adjusting capacity so as to improve the imaging quality.

Description

Optical imaging system

Technical Field

The utility model relates to an optical imaging system, concretely relates to be applied to miniaturized optical imaging system on electronic product.

Background

In recent years, with the rise of portable electronic products with a photographing function, the demand of an optical system is increasing. The photosensitive devices of a typical optical system are not limited to a Charge Coupled Device (CCD) or a Complementary Metal-Oxide semiconductor (CMOS) Device, and with the refinement of semiconductor process technology, the pixel size of the photosensitive Device is reduced, and the optical system is gradually developed in the high pixel field, so that the requirements for imaging quality are increased.

The conventional optical system mounted on the portable device mainly adopts a two-piece or three-piece lens structure, however, the portable device is continuously lifting pixels and the end consumer needs a large aperture, such as a low light and night photographing function, or a wide viewing angle, such as a self-photographing function of a front lens. The optical system with only large aperture is usually subject to the situation of generating more aberration, which causes the degradation of peripheral imaging quality and the difficulty of manufacturing, while the optical system with wide viewing angle is subject to the increase of imaging distortion (distortion), and the conventional optical imaging system cannot meet the requirement of higher order photography.

Therefore, how to effectively increase the light-entering amount of the optical imaging system and increase the viewing angle of the optical imaging system, not only further increase the total pixel and quality of the image, but also consider the balance design of the miniaturized optical imaging system, becomes a very important issue.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an optical imaging system, its combination that can utilize the refractive power of four lenses, convex surface and concave surface (convex surface or concave surface mean the object side or the image side of each lens in principle in the epaxial geometry description of light), and then effectively improve optical imaging system's the light inlet and increase optical imaging system's visual angle, improve the total pixel and the quality of formation of image simultaneously to be applied to on the miniature electronic product.

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes:

an optical imaging system, comprising, in order from an object side to an image side:

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power; and

an imaging surface;

wherein the optical imaging system has four lenses with refractive power, at least one of the first to fourth lenses has positive refractive power, the focal lengths of the first to fourth lenses ARE f1, f2, f3 and f4, respectively, the focal length of the optical imaging system is f, the diameter of the entrance pupil of the optical imaging system is HEP, a distance HOS is provided on the optical axis from the object-side surface of the first lens to the image-side surface of the fourth lens, a distance idtl is provided on the optical axis from the object-side surface of the first lens to the image-side surface of the fourth lens, half of the maximum viewing angle of the optical imaging system is HAF, the intersection point of any surface of any lens in each lens and the optical axis is a starting point, a coordinate point at a vertical height from the contour of the surface to the diameter of the entrance pupil of the optical axis 1/2 is an ending point on the surface, and the length of the contour curve between the two points is ARE AREs, it satisfies the following conditions: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

Preferably, the TV distortion of the optical imaging system at the time of image combination is TDT, wherein the optical imaging system has a maximum imaging height HOI on the imaging plane perpendicular to the optical axis, the lateral aberration of the optical imaging system at 0.7HOI passing through the entrance pupil edge and incident on the imaging plane at the longest operating wavelength of the positive meridian fan is represented by PLTA, the lateral aberration of the optical imaging system at 0.7HOI passing through the entrance pupil edge and incident on the imaging plane at the shortest operating wavelength of the positive meridian fan is represented by PSTA, the lateral aberration of the optical imaging system at 0.7HOI passing through the entrance pupil edge and incident on the imaging plane at the longest operating wavelength of the negative meridian fan is represented by NLTA, the lateral aberration of the optical imaging system at 0.7HOI passing through the entrance pupil edge and incident on the imaging plane at the longest operating wavelength of the sagittal plane fan is represented by NSTA, and the lateral image at 0.7HOI passing through the entrance pupil edge and incident on the imaging plane at the longest operating wavelength of the sagittal plane is represented by PLTA The difference is expressed in SLTA and the lateral aberration of the sagittal plane light fan, which has the shortest operating wavelength passing through the entrance pupil edge and incident at 0.7HOI on the imaging plane, is expressed in SSTA, which satisfies the following condition: PLTA is less than or equal to 100 microns; PSTA not more than 100 microns; NLTA is less than or equal to 100 micrometers; NSTA is less than or equal to 100 microns; SLTA is less than or equal to 100 microns; and SSTA of less than or equal to 100 microns; TDT | is < 100%.

Preferably, the maximum effective radius of any one surface of any one of the lenses is expressed by EHD, the intersection point of any one surface of any one of the lenses with the optical axis is a starting point, the contour of the surface is followed up to the maximum effective radius of the surface thereof is an end point, the length of the contour curve between the two points is ARS, which satisfies the following formula: 0.9-2.0 of ARS/EHD.

Preferably, the optical imaging system satisfies the following formula: HOS is more than 0mm and less than or equal to 50 mm.

Preferably, the imaging surface can be selected to be a plane or a curved surface.

Preferably, an intersection point of the object-side surface of the fourth lens on the optical axis is a starting point, a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 along the contour of the surface is a terminal point, a contour curve length between the two points is ARE41, an intersection point of the image-side surface of the fourth lens on the optical axis is a starting point, a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 along the contour of the surface is a terminal point, a contour curve length between the two points is ARE42, and a thickness of the fourth lens on the optical axis is TP4, which satisfy the following conditions: ARE41/TP4 of 0.05-25; and 0.05. ltoreq. ARE42/TP 4. ltoreq.25.

Preferably, an intersection point of the object-side surface of the third lens on the optical axis is a starting point, a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 along the contour of the surface is a terminal point, a contour curve length between the two points is ARE31, an intersection point of the image-side surface of the third lens on the optical axis is a starting point, a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 along the contour of the surface is a terminal point, a contour curve length between the two points is ARE32, and a thickness of the third lens on the optical axis is TP3, which satisfy the following conditions: ARE31/TP3 of 0.05-25; and 0.05. ltoreq. ARE32/TP 3. ltoreq.25.

Preferably, the first lens element with negative refractive power.

Preferably, the optical lens further comprises an aperture, and a distance InS on the optical axis from the aperture to the imaging surface satisfies the following formula: 0.2-1.1 of InS/HOS.

Preferably, an optical imaging system comprises, in order from an object side to an image side:

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power; and

an imaging surface;

wherein the optical imaging system has four lenses with refractive power, at least one surface of at least one of the first lens element to the fourth lens element has at least one inflection point, at least one of the second lens element to the fourth lens element has positive refractive power, focal lengths of the first lens element to the fourth lens element are f1, f2, f3 and f4, respectively, the focal length of the optical imaging system is f, an entrance pupil diameter of the optical imaging system is HEP, a distance HOS is provided on an optical axis from an object-side surface of the first lens element to an image-forming surface of the fourth lens element, a distance idtl is provided on an optical axis from the object-side surface of the first lens element to the image-side surface of the fourth lens element, half of a maximum visible angle of the optical imaging system is HAF, an intersection point of any one of the lenses with the optical axis is a starting point, and a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 along a contour of the surface is a final point, the length of the profile curve between the two points is ARE, which satisfies the following condition: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

Preferably, the maximum effective radius of any one surface of any one of the lenses is expressed by EHD, the intersection point of any one surface of any one of the lenses with the optical axis is a starting point, the contour of the surface is followed up to the maximum effective radius of the surface is an end point, and the length of the contour curve between the two points is ARS, which satisfies the following formula: 0.9-2.0 of ARS/EHD.

Preferably, at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point.

Preferably, the optical imaging system has a maximum imaging height HOI perpendicular to the optical axis on the imaging plane, the maximum operating wavelength of a positive meridian plane fan of the optical imaging system passing through the entrance pupil edge and being incident at 0.7HOI on the imaging plane is denoted by PLTA, the minimum operating wavelength of a positive meridian plane fan thereof passing through the entrance pupil edge and being incident at 0.7HOI on the imaging plane is denoted by PSTA, the maximum operating wavelength of a negative meridian plane fan passing through the entrance pupil edge and being incident at 0.7HOI on the imaging plane is denoted by NLTA, the minimum operating wavelength of a negative meridian plane fan passing through the entrance pupil edge and being incident at 0.7HOI on the imaging plane is denoted by NSTA, the maximum operating wavelength of a sagittal plane fan passing through the entrance pupil edge and being incident at 0.7HOI on the imaging plane is denoted by SLTA, the transverse aberration of the sagittal plane light fan, at a shortest operating wavelength of 0.7HOI through the entrance pupil edge and incident on the imaging plane, is denoted SSTA, which satisfies the following condition: PLTA is less than or equal to 50 microns; PSTA not more than 50 microns; NLTA is less than or equal to 50 microns; NSTA is less than or equal to 50 microns; SLTA is less than or equal to 50 microns; and SSTA of less than or equal to 50 microns.

Preferably, the first lens element with negative refractive power.

Preferably, the distance between the first lens and the second lens on the optical axis is IN12, and satisfies the following formula: 0< IN12/f is less than or equal to 60.

Preferably, a distance between the third lens and the fourth lens on the optical axis is IN34, and satisfies the following formula: 0< IN34/f is less than or equal to 5.

Preferably, the distance between the third lens and the fourth lens on the optical axis is IN34, and the thicknesses of the third lens and the fourth lens on the optical axis are TP3 and TP4, respectively, which satisfy the following conditions: (TP4+ IN34)/TP3 is more than or equal to 1 and less than or equal to 10.

Preferably, the distance between the first lens and the second lens on the optical axis is IN12, and the thicknesses of the first lens and the second lens on the optical axis are TP1 and TP2, respectively, which satisfy the following conditions: (TP1+ IN12)/TP2 is more than or equal to 1 and less than or equal to 10.

Preferably, at least one of the first lens, the second lens, the third lens and the fourth lens is a light filtering component with a wavelength less than 500 nm.

a first lens element with negative refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power having at least one inflection point on at least one of an object-side surface and an image-side surface thereof; and

an imaging surface;

wherein the optical imaging system has four lenses with refractive power and at least one surface of at least one of the first lens to the third lens has at least one inflection point, the focal lengths of the first lens to the fourth lens are f1, f2, f3 and f4, respectively, the focal length of the optical imaging system is f, the diameter of the entrance pupil of the optical imaging system is HEP, a distance HOS is provided on the optical axis from the object-side surface of the first lens to the image-forming surface, a distance idtl is provided on the optical axis from the object-side surface of the first lens to the image-side surface of the fourth lens, half of the maximum viewing angle of the optical imaging system is HAF, the intersection point of any one surface of any one lens among the lenses and the optical axis is a starting point, and the coordinate point along the contour of the surfaces up to the vertical height on the surface from the diameter of the entrance pupil of the optical axis 1/2 is an end point, the length of the profile curve between the two points is ARE, which satisfies the following condition: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

Preferably, the optical imaging system further includes an aperture, an image sensor disposed on the image plane and having a distance InS from the aperture to the image plane, and a driving module coupled to each lens for displacing each lens, wherein the following formula is satisfied: 0.2-1.1 of InS/HOS.

Compared with the prior art, the utility model has the following advantage:

the utility model provides a pair of optical imaging system, the object side or the image side of its fourth lens are provided with anti-curved point, can effectively adjust each visual field and incide in the angle of fourth lens to revise to optics distortion and TV distortion. In addition, the surface of the fourth lens can have better optical path adjusting capability so as to improve the imaging quality.

The profile curve length of any surface of a single lens in the maximum effective radius range affects the ability of the surface to correct aberrations and optical path differences between the light beams of each field, and the longer the profile curve length, the higher the aberration correction ability, but at the same time, the difficulty in manufacturing is increased, so that the profile curve length of any surface of a single lens in the maximum effective radius range must be controlled, and particularly, the proportional relationship (ARS/TP) between the profile curve length (ARS) of the surface in the maximum effective radius range and the Thickness (TP) of the lens on the optical axis to which the surface belongs must be controlled. For example, the length of the profile curve of the maximum effective radius of the object-side surface of the first lens is represented by ARS11, the thickness of the first lens on the optical axis is TP1, the ratio of the two is ARS11/TP1, the length of the profile curve of the maximum effective radius of the image-side surface of the first lens is represented by ARS12, and the ratio of the length of the profile curve of the maximum effective radius of the image-side surface of the first lens to TP1 is ARS12/TP 1. The length of the profile curve of the maximum effective radius of the object-side surface of the second lens is shown as ARS21, the thickness of the second lens on the optical axis is TP2, the ratio of the two is ARS21/TP2, the length of the profile curve of the maximum effective radius of the image-side surface of the second lens is shown as ARS22, and the ratio of the length of the profile curve of the maximum effective radius of the image-side surface of the second lens to TP2 is ARS22/TP 2. The proportion of the length of the profile curve of the maximum effective radius of any surface of the rest of the lenses in the optical imaging system to the Thickness (TP) of the lens to which the surface belongs on the optical axis is expressed in the same way.

The profile length of any surface of the single lens in the height range of 1/2 entrance pupil diameter (HEP) particularly affects the ability of the surface to correct aberrations in the shared area of each field of view and the optical path difference between the light beams of each field of view, and the longer the profile length, the higher the ability to correct aberrations, but also increases the difficulty of manufacturing, so the ratio (ARE/TP) between the profile length of any surface of the single lens in the height range of 1/2 entrance pupil diameter (HEP), particularly between the profile length (ARE) in the height range of 1/2 entrance pupil diameter (HEP) of the surface and the Thickness (TP) of the lens on the optical axis to which the surface belongs must be controlled. For example, the length of the profile curve of the 1/2 entrance pupil diameter (HEP) height of the object-side surface of the first lens is ARE11, the thickness of the first lens on the optical axis is TP1, the ratio of the two is ARE11/TP1, the length of the profile curve of the 1/2 entrance pupil diameter (HEP) height of the image-side surface of the first lens is ARE12, and the ratio of the length of the profile curve to the TP1 is ARE12/TP 1. The length of the profile curve of the 1/2 entrance pupil diameter (HEP) height of the object-side surface of the second lens is represented by ARE21, the thickness of the second lens on the optical axis is TP2, the ratio of the two is ARE21/TP2, the length of the profile curve of the 1/2 entrance pupil diameter (HEP) height of the image-side surface of the second lens is represented by ARE22, and the ratio of the length of the profile curve to TP2 is ARE22/TP 2. The relationship between the length of the profile curve of 1/2 entrance pupil diameter (HEP) height of any surface of the remaining lenses in the optical imaging system and the Thickness (TP) of the lens on the optical axis to which that surface belongs is expressed by analogy.

The optical imaging system can be used to image an image sensor with a diagonal dimension of 1/1.2 inch or less, wherein the image sensor preferably has a dimension of 1/2.3 inch, the image sensor preferably has a pixel dimension of less than 1.4 micrometers (μm), more preferably has a pixel dimension of less than 1.12 micrometers (μm), and most preferably has a pixel dimension of less than 0.9 micrometers (μm). Furthermore, the optical imaging system may be adapted for use with an aspect ratio of 16: 9 image sensor assembly.

The optical imaging system can be suitable for the video recording requirement (such as 4K2K or UHD and QHD) of more than million or ten million pixels and has good imaging quality.

When f1 | > f4, the total Height (HOS) of the optical imaging System can be reduced to achieve miniaturization.

When | f2 | + -f 3 | f1 | + | f4 |, at least one of the second lens element and the third lens element has weak positive refractive power or weak negative refractive power. The term "weak refractive power" refers to the absolute value of the focal length of a particular lens element greater than 10 mm. When the present invention is used, at least one of the second lens element and the third lens element has weak positive refractive power, which effectively shares the positive refractive power of the first lens element to avoid the occurrence of unnecessary aberration too early, otherwise, if at least one of the second lens element and the third lens element has weak negative refractive power, the aberration of the correction system can be finely adjusted.

The fourth lens element with negative refractive power has a concave image-side surface. Thereby, the back focal length is advantageously shortened to maintain miniaturization. In addition, at least one surface of the fourth lens element can have at least one point of inflection, which can effectively suppress the incident angle of the light in the off-axis field of view, and further correct the aberration in the off-axis field of view.

Drawings

The above and other features of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic view of an optical imaging system according to a first embodiment of the present invention;

fig. 2 is a graph showing spherical aberration, astigmatism and optical distortion of the optical imaging system according to the first embodiment of the present invention;

fig. 3 is a transverse aberration diagram of the meridional and sagittal fans of the optical imaging system of the first embodiment of the invention, the longest operating wavelength and the shortest operating wavelength passing through the aperture edge at 0.7 field of view;

fig. 4 is a schematic diagram of an optical imaging system according to a second embodiment of the present invention;

fig. 5 is a graph showing a spherical aberration, astigmatism and optical distortion of the optical imaging system according to the second embodiment of the present invention from left to right;

fig. 6 is a transverse aberration diagram of the meridional and sagittal fans of the optical imaging system of the second embodiment of the invention, the longest operating wavelength and the shortest operating wavelength passing through the aperture edge at 0.7 field of view;

fig. 7 is a schematic diagram of an optical imaging system according to a third embodiment of the present invention;

fig. 8 is a graph showing a spherical aberration, astigmatism and optical distortion of the optical imaging system according to the third embodiment of the present invention from left to right;

fig. 9 is a lateral aberration diagram of the meridional and sagittal fans of the optical imaging system of the third embodiment of the invention, with the longest and shortest operating wavelengths passing through the aperture edge at 0.7 field of view;

fig. 10 is a schematic view of an optical imaging system according to a fourth embodiment of the present invention;

fig. 11 is a graph showing spherical aberration, astigmatism and optical distortion of the optical imaging system according to the fourth embodiment of the present invention from left to right;

fig. 12 is a transverse aberration diagram of the meridional and sagittal fans of the optical imaging system of the fourth embodiment of the invention, with the longest and shortest operating wavelengths passing through the aperture edge at 0.7 field of view;

fig. 13 is a schematic view of an optical imaging system according to a fifth embodiment of the present invention;

fig. 14 is a graph showing a spherical aberration, astigmatism and optical distortion of the optical imaging system according to the fifth embodiment of the present invention from left to right;

fig. 15 is a lateral aberration diagram of the meridional and sagittal fans of the optical imaging system of the fifth embodiment of the invention, with the longest operating wavelength and the shortest operating wavelength passing through the aperture edge at the 0.7 field of view;

fig. 16 is a schematic view of an optical imaging system according to a sixth embodiment of the present invention;

fig. 17 is a graph showing a spherical aberration, astigmatism and optical distortion of the optical imaging system according to the sixth embodiment of the present invention from left to right in sequence;

fig. 18 is a lateral aberration diagram of the meridional and sagittal fans of the optical imaging system of the sixth embodiment of the invention, with the longest and shortest operating wavelengths passing through the aperture edge at the 0.7 field of view.

[ notation ] to show

1,20,30,40,50,60 optical imaging system

100,200,300,400,500,600 aperture

110,210,310,410,510,610 first lens

112,212,312,412,512,612 object side

114,214,314,414,514,614 image side

120,220,320,420,520,620 second lens

122,222,322,422,522,622 object side

124,224,324,424,524,624 image side

130,230,330,430,530,630 third lens

132,232,332,432,532,632 object side

134,234,334,434,534,634 image side

140,240,340,440,540,640 fourth lens

142,242,342,442,542,642 object side

144,244,344,444,544,644 image side

170,270,370,470,570,670 infrared filter

180,280,380,480,580,680 image plane

190,290,390,490,590,690 image sensor assembly

f focal length of optical imaging system

f1, f2, f3, f4 focal lengths of the first to fourth lenses

F/HEP, Fno, F # (aperture value of optical imaging system)

HAF half of maximum viewing angle of optical imaging system

NA1 Abbe number of first lens

NA2, NA3, NA4 Abbe numbers of second to fourth lenses

R1, R2 radius of curvature of object-side and image-side surfaces of first lens

R3, R4 radius of curvature of object-side and image-side surfaces of second lens

R5, R6 radius of curvature of object-side and image-side surfaces of third lens

R7, R8 radius of curvature of object-side and image-side surfaces of fourth lens

TP1 thickness of first lens on optical axis

TP2, TP3, TP4 thicknesses of the second to fourth lenses on the optical axis

Sigma TP, sum of thicknesses of all lenses with refractive power

IN12 optical axis distance between the first and second lenses

IN23 distance between the second lens and the third lens on optical axis

IN34 distance between the third lens and the fourth lens on optical axis

inRS41 maximum effective distance from the intersection of the fourth lens object-side surface on the optical axis to the fourth lens object-side surface

Horizontal displacement distance of radius position on optical axis

IF411, the point of inflection on the object-side surface of the fourth lens closest to the optical axis; SGI411 amount of sinking of this Point

HIF411 vertical distance between inflection point closest to optical axis on object-side surface of fourth lens and optical axis

IF421, the point of inflection closest to the optical axis on the image-side surface of the fourth lens; SGI421 amount of subsidence of this point

HIF421, vertical distance between the inflection point closest to optical axis on image-side surface of fourth lens and optical axis

IF412, a second point of inflection near the optical axis on the object-side surface of the fourth lens; SGI412 amount of subsidence of this point

HIF412 vertical distance between second inflection point near optical axis on object side of fourth lens and optical axis

IF422, a second inflection point near the optical axis on the image-side surface of the fourth lens; SGI422 amount of subsidence at this point

HIF422 vertical distance between the second inflection point near the optical axis on the image-side surface of the fourth lens and the optical axis

IF413 the third point of inflection near the optical axis on the object-side of the fourth lens; SGI413 amount of subsidence at this point

HIF413 vertical distance between optical axis and third inflection point near optical axis on object-side surface of fourth lens

An IF423, a third inflection point on the image-side surface of the fourth lens, which is close to the optical axis; SGI423 amount of sinking of this Point

HIF423 vertical distance between the third inflection point close to the optical axis on the image side of the fourth lens and the optical axis

An inflection point on an object-side surface of the fourth lens of the IF414 near the optical axis; SGI414 amount of subsidence at this point

HIF414 vertical distance between fourth inflection point near optical axis on object side of fourth lens and optical axis

IF424, fourth inflection point near the optical axis on the image-side surface of the fourth lens; SGI424 amount of subsidence of this point

HIF424 vertical distance between fourth inflection point near optical axis on image side of fourth lens and optical axis

C41 critical point of object side of the fourth lens; c42 critical point of image side surface of fourth lens

SGC41 horizontal displacement distance of critical point of object side surface of fourth lens and optical axis

SGC42 horizontal displacement distance between critical point of image side surface of fourth lens and optical axis

HVT41 perpendicular distance between critical point of object side surface of fourth lens and optical axis

HVT42 vertical distance between critical point of image side surface of fourth lens and optical axis

HOS total height (distance on optical axis from object side surface of first lens to image plane)

Dg is the length of the diagonal line of the image sensing component; InS is the distance from the aperture to the image plane

InTL is the distance from the object side surface of the first lens to the image side surface of the fourth lens

InB is the distance from the image side surface of the fourth lens to the imaging surface

HOI half of diagonal length of effective sensing area of image sensing component (maximum image height)

TDT TV Distortion (TV Distortion) of optical imaging system in image formation

ODT Optical Distortion (Optical Distortion) of an Optical imaging system at the time of image formation.

The embodiment of the present invention relates to the following terms and their code numbers of the lens parameters, which are used as the reference for the following description:

lens parameters related to length or height:

the imaging height of the optical imaging system is represented by HOI; the height of the optical imaging system is denoted by HOS; the distance between the object side surface of the first lens and the image side surface of the fourth lens of the optical imaging system is represented by InTL; the distance between the image side surface of the fourth lens of the optical imaging system and the imaging surface is represented by InB; instl + InB ═ HOS; the distance between a fixed diaphragm (aperture) of the optical imaging system and an imaging surface is represented by InS; the distance between the first lens and the second lens of the optical imaging system is denoted (example) by IN 12; the thickness of the first lens of the optical imaging system on the optical axis is denoted by TP1 (example).

Material dependent lens parameters:

the abbe number of the first lens of the optical imaging system is denoted (example) by NA 1; the refractive index of the first lens is denoted by Nd1 (example).

Viewing angle-dependent lens parameters:

the viewing angle is denoted AF; half of the viewing angle is denoted by HAF; the chief ray angle is denoted MRA.

Lens parameters related to entrance and exit pupils:

the entrance pupil diameter of the optical imaging system is denoted by HEP; the maximum Effective radius of any surface of a single lens refers to the vertical height between the intersection point (Effective halo Diameter; EHD) of the lens surface where the rays of the incident light passing through the extreme edge of the entrance pupil at the maximum viewing angle of the system meet the optical axis. For example, the maximum effective radius of the object-side surface of the first lens is indicated by EHD11 and the maximum effective radius of the image-side surface of the first lens is indicated by EHD 12. The maximum effective radius of the object-side surface of the second lens is indicated by EHD21 and the maximum effective radius of the image-side surface of the second lens is indicated by EHD 22. The maximum effective radius of any surface of the remaining lenses in the optical imaging system is expressed and so on.

Parameters related to the lens surface profile arc length and surface profile:

the maximum effective radius profile curve length of any surface of a single lens refers to the curve length of the maximum effective radius, which is expressed by ARS, from the starting point along the surface profile of the lens to the end point of the maximum effective radius, wherein the intersection point of the surface of the lens and the optical axis of the optical imaging system is the starting point, and the curve arc length between the two points is the maximum effective radius profile curve length. For example, the profile curve length for the maximum effective radius of the object-side surface of the first lens is shown as ARS11 and the profile curve length for the maximum effective radius of the image-side surface of the first lens is shown as ARS 12. The profile curve length for the maximum effective radius of the object-side surface of the second lens is denoted as ARS21 and the profile curve length for the maximum effective radius of the image-side surface of the second lens is denoted as ARS 22. The length of the profile curve of the maximum effective radius of any surface of the remaining lenses in the optical imaging system is expressed in analogy.

The contour curve length of 1/2 entrance pupil diameter (HEP) of any surface of a single lens means that the intersection point of the surface of the lens and the optical axis of the optical imaging system is a starting point, a coordinate point from the starting point along the contour of the surface of the lens to the vertical height from the optical axis 1/2 entrance pupil diameter on the surface is an end point, and the curve arc length between the two points is the contour curve length of 1/2 entrance pupil diameter (HEP) and is expressed by ARE. For example, the contour curve length for the 1/2 entrance pupil diameter (HEP) of the object-side surface of the first lens is denoted as ARE11, and the contour curve length for the 1/2 entrance pupil diameter (HEP) of the image-side surface of the first lens is denoted as ARE 12. The contour curve length for the 1/2 entrance pupil diameter (HEP) of the object-side surface of the second lens is denoted as ARE21, and the contour curve length for the 1/2 entrance pupil diameter (HEP) of the image-side surface of the second lens is denoted as ARE 22. The profile curve length representation of 1/2 entrance pupil diameter (HEP) for either surface of the remaining lenses in the optical imaging system, and so on.

Parameters related to lens profile depth:

the horizontal displacement distance on the optical axis from the intersection point of the object-side surface of the fourth lens on the optical axis to the maximum effective radius position of the object-side surface of the fourth lens is represented by InRS41 (example); the horizontal displacement distance on the optical axis from the intersection point of the image side surface of the fourth lens on the optical axis to the maximum effective radius position of the image side surface of the fourth lens is denoted by InRS42 (example).

Parameters related to lens surface shape:

the critical point C is a point on the surface of the particular lens that is tangent to a tangent plane perpendicular to the optical axis, except for the intersection with the optical axis. As described above, for example, the perpendicular distance between the critical point C31 of the object-side surface of the third lens and the optical axis is HVT31 (example), the perpendicular distance between the critical point C32 of the image-side surface of the third lens and the optical axis is HVT32 (example), the perpendicular distance between the critical point C41 of the object-side surface of the fourth lens and the optical axis is HVT41 (example), and the perpendicular distance between the critical point C42 of the image-side surface of the fourth lens and the optical axis is HVT42 (example). The representation of the critical point on the object-side or image-side surface of the other lens and its perpendicular distance from the optical axis and so on.

The inflection point on the object-side surface of the fourth lens closest to the optical axis is IF411, the depression of the inflection point is SGI411 (for example), SGI411 is the horizontal displacement distance parallel to the optical axis between the intersection point of the object-side surface of the fourth lens on the optical axis and the inflection point on the object-side surface of the fourth lens closest to the optical axis, and the vertical distance between the point of IF411 and the optical axis is HIF411 (for example). The inflection point closest to the optical axis on the image-side surface of the fourth lens is IF421, the depression amount SGI421 (for example), SGI411 is the horizontal displacement distance parallel to the optical axis between the intersection point of the image-side surface of the fourth lens on the optical axis and the inflection point closest to the optical axis on the image-side surface of the fourth lens, and the vertical distance between the point of the IF421 and the optical axis is HIF421 (for example).

The second inflection point on the object-side surface of the fourth lens near the optical axis is IF412, the depression amount SGI412 (for example), SGI412 is the horizontal displacement distance parallel to the optical axis from the intersection point of the object-side surface of the fourth lens on the optical axis to the second inflection point on the object-side surface of the fourth lens near the optical axis, and the vertical distance between the point of the IF412 and the optical axis is HIF412 (for example). The second inflection point on the image-side surface of the fourth lens near the optical axis is IF422, the depression amount SGI422 (for example), SGI422 is the horizontal displacement distance parallel to the optical axis from the intersection point of the image-side surface of the fourth lens on the optical axis to the second inflection point on the image-side surface of the fourth lens near the optical axis, and the vertical distance between the point of the IF422 and the optical axis is HIF422 (for example).

The third inflection point on the object-side surface of the fourth lens near the optical axis is IF413, the depression amount SGI413 (for example), SGI413 is the horizontal displacement distance parallel to the optical axis from the intersection point of the object-side surface of the fourth lens on the optical axis to the third inflection point on the object-side surface of the fourth lens near the optical axis, and the vertical distance between the point of IF4132 and the optical axis is HIF413 (for example). The third inflection point on the image side surface of the fourth lens close to the optical axis is IF423, the depression amount SGI423 (for example), SGI423 is a horizontal displacement distance parallel to the optical axis from the intersection point of the image side surface of the fourth lens on the optical axis to the third inflection point on the image side surface of the fourth lens close to the optical axis, and the vertical distance between the point of the IF423 and the optical axis is HIF423 (for example).

A fourth inflection point on the object-side surface of the fourth lens, which is close to the optical axis, is IF414, which is a depression amount SGI414 (for example), SGI414 is a horizontal displacement distance parallel to the optical axis from an intersection point of the object-side surface of the fourth lens on the optical axis to the fourth inflection point on the object-side surface of the fourth lens, which is close to the optical axis, and a vertical distance between the point of the IF414 and the optical axis is HIF414 (for example). The fourth inflection point on the image-side surface of the fourth lens near the optical axis is IF424, the depression amount SGI424 (for example), SGI424 is the horizontal displacement distance parallel to the optical axis from the intersection point of the image-side surface of the fourth lens on the optical axis to the fourth inflection point on the image-side surface of the fourth lens near the optical axis, and the vertical distance between the point of IF424 and the optical axis is HIF424 (for example).

The other lens 'object or image side surface's inflection point and its perpendicular distance from the optical axis or its amount of depression, and so on.

Aberration-related variables:

optical Distortion (Optical Distortion) of an Optical imaging system is expressed in ODT; its TV Distortion (TV Distortion) is expressed in TDT and can further define the degree of aberration shift described between imaging 50% to 100% field of view; the spherical aberration offset is expressed as DFS; the coma aberration offset is denoted by DFC.

The lateral aberration at the aperture edge is represented by sta (stop Transverse aberration), and the performance of a specific optical imaging system can be evaluated by calculating the lateral aberration of light in any field of view on a meridian fan (tangential fan) or a sagittal fan (sagittal fan), and particularly calculating the lateral aberration magnitude passing through the aperture edge at the longest operating wavelength (for example, 650NM) and the shortest operating wavelength (for example, 470NM) respectively as the criterion of excellent performance. The coordinate directions of the meridian plane sectors can be further divided into positive (upward rays) and negative (downward rays). The lateral aberration of the longest operating wavelength passing through the aperture edge, which is defined as the difference between the distance between the longest operating wavelength passing through the aperture edge and the imaging position of the specified field of view on the imaging plane, and the distance between the reference wavelength chief ray (e.g., wavelength of 555NM) and the imaging position of the field of view on the imaging plane, the lateral aberration of the shortest operating wavelength passing through the aperture edge, which is defined as the imaging position of the shortest operating wavelength passing through the aperture edge and the imaging position of the specified field of view on the imaging plane, and the distance between the reference wavelength chief ray and the imaging position of the field of view on the imaging plane, can be evaluated as excellent performance of the specified optical imaging system, and the lateral aberrations of the shortest and longest operating wavelengths of 0.7 field of view (i.e., 0.7 imaging height HOI) incident through the aperture edge and the imaging plane can be both less than 100 micrometers (μm) as a check mode, and even further the lateral aberrations of the 0.7 field of view on the imaging plane, which the shortest and longest operating wavelength passes through the aperture edge and the imaging plane All less than 80 micrometers (mum) are used as a check mode.

The optical imaging system has a maximum imaging height HOI on an imaging plane perpendicular to an optical axis, a transverse aberration at 0.7HOI on the imaging plane and passing through an edge of the entrance pupil is denoted by PLTA, a visible shortest operating wavelength of a positive meridional fan thereof passes through the edge of the entrance pupil and is incident on the imaging plane at 0.7HOI is denoted by PSTA, a transverse aberration at 0.7HOI on the imaging plane and passes through the edge of the entrance pupil is denoted by NLTA, a visible shortest operating wavelength of a negative meridional fan passes through the edge of the entrance pupil and is incident on the imaging plane at 0.7HOI is denoted by NSTA, a transverse aberration at 0.7HOI on the imaging plane and passes through the edge of the entrance pupil and is incident on the imaging plane at 0.7HOI is denoted by SLTA, the transverse aberration at 0.7HOI incident on the imaging plane at the shortest operating wavelength of visible light of the sagittal plane light fan passing through the entrance pupil edge is denoted SSTA.

Detailed Description

An optical imaging system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element with refractive power. The optical imaging system further comprises an image sensing component which is arranged on the imaging surface.

The optical imaging system can be designed using three operating wavelengths, 486.1nm, 587.5nm, 656.2nm, wherein 587.5nm is the reference wavelength for which the main reference wavelength is the main technical feature. The optical imaging system can also be designed using five operating wavelengths, 470nm, 510nm, 555nm, 610nm, 650nm, respectively, where 555nm is the reference wavelength for which the main reference wavelength is the main technical feature.

The ratio PPR of the focal length f of the optical imaging system to the focal length fp of each lens with positive refractive power, the ratio NPR of the focal length f of the optical imaging system to the focal length fn of each lens with negative refractive power, the sum of the PPRs of all the lenses with positive refractive power is Σ PPR, and the sum of the NPRs of all the lenses with negative refractive power is Σ NPR, which is helpful to control the total refractive power and the total length of the optical imaging system when the following conditions are satisfied: 0.5 ≦ Σ PPR/| Σ NPR ≦ 4.5, preferably, the following condition may be satisfied: 1 ≦ Σ PPR/| Σ NPR | < 3.5.

The optical imaging system has a height of HOS, and when the HOS/f ratio approaches to 1, the optical imaging system is advantageous for manufacturing a miniaturized optical imaging system capable of imaging ultrahigh pixels.

The total sum fp of the focal length of each lens with positive refractive power of the optical imaging system is Σ PP, and the total sum of the focal length of each lens with negative refractive power is Σ NP, the utility model discloses an embodiment of the optical imaging system, it satisfies the following condition: 0< sigma PP is less than or equal to 200; and f 1/Sigma PP is less than or equal to 0.85. Preferably, the following conditions may be satisfied: 0< sigma PP is less than or equal to 150; and f 1/Sigma PP is more than or equal to 0.01 and less than or equal to 0.7. Thereby, it is helpful to control the focusing ability of the optical imaging system and properly distribute the positive refractive power of the system to suppress the premature generation of significant aberrations.

The first lens element with positive refractive power has a convex object-side surface. Therefore, the positive refractive power strength of the first lens element can be properly adjusted, which is beneficial to shortening the total track length of the optical imaging system.

The second lens element has negative refractive power. Therefore, the aberration generated by the first lens can be corrected.

The third lens element can have positive refractive power. Therefore, the positive refractive power of the first lens element can be shared.

The fourth lens element with negative refractive power has a concave image-side surface. Thereby, the back focal length is advantageously shortened to maintain miniaturization. In addition, at least one surface of the fourth lens element can have at least one point of inflection, which can effectively suppress the incident angle of the light in the off-axis field of view, and further correct the aberration in the off-axis field of view. Preferably, the object side and the image side of the image sensor have at least one inflection point.

The optical imaging system may further include an image sensor disposed on the imaging surface. Half of the diagonal length of the effective sensing area of the image sensing element (i.e. the imaging height of the optical imaging system or the maximum image height) is HOI, and the distance from the object-side surface of the first lens to the imaging surface on the optical axis is HOS, which satisfies the following conditions: HOS/HOI is less than or equal to 3; and HOS/f is more than or equal to 0.5 and less than or equal to 3.0. Preferably, the following conditions may be satisfied: HOS/HOI is more than or equal to 1 and less than or equal to 2.5; and HOS/f is more than or equal to 1 and less than or equal to 2. Therefore, the miniaturization of the optical imaging system can be maintained, and the optical imaging system can be carried on light and thin portable electronic products.

Additionally, the utility model discloses an among the optical imaging system, can set up an at least light ring according to the demand to reduce stray light, help promoting image quality.

The utility model discloses an among the optical imaging system, the diaphragm configuration can be leading light ring or put the light ring, and wherein leading light ring is the light ring and sets up between shot object and first lens promptly, and the middle-placed light ring then shows that the light ring sets up between first lens and imaging surface. If the diaphragm is a front diaphragm, the exit pupil of the optical imaging system can generate a longer distance with the imaging surface to accommodate more optical components, and the image receiving efficiency of the image sensing component can be increased; if the diaphragm is arranged in the middle, the wide-angle lens is beneficial to expanding the field angle of the system, so that the optical imaging system has the advantage of a wide-angle lens. The distance between the diaphragm and the imaging surface is InS, which satisfies the following conditions: 0.2-1.1 of InS/HOS. Preferably, the following conditions may be satisfied: 0.8-1 of InS/HOS. This makes it possible to maintain both the miniaturization of the optical imaging system and the wide-angle characteristic.

The utility model discloses an among the optical imaging system, the distance between first lens objective face to fourth lens image side face is the InTL, and the thickness sum of all lens that have refractive power on the optical axis is sigma TP, and it satisfies the following condition: the Sigma TP/InTL ratio is more than or equal to 0.45 and less than or equal to 0.95. Preferably, the following conditions may be satisfied: sigma TP/InTL is more than or equal to 0.6 and less than or equal to 0.9. Therefore, the contrast of system imaging and the yield of lens manufacturing can be considered simultaneously, and a proper back focal length is provided for accommodating other components.

The radius of curvature of the object-side surface of the first lens is R1, and the radius of curvature of the image-side surface of the first lens is R2, which satisfies the following conditions: the | R1/R2 | is not less than 0.01 and not more than 0.5. Therefore, the first lens element has proper positive refractive power strength, and the spherical aberration is prevented from increasing and speeding up. Preferably, the following conditions may be satisfied: the | R1/R2 | is not less than 0.01 and not more than 0.4.

The radius of curvature of the object-side surface of the fourth lens is R7, and the radius of curvature of the image-side surface of the fourth lens is R8, which satisfies the following conditions: -200< (R7-R8)/(R7+ R8) < 30. Therefore, astigmatism generated by the optical imaging system is favorably corrected.

The first lens and the second lens are separated by a distance IN12 on the optical axis, which satisfies the following condition: 0< IN12/f is less than or equal to 60. Preferably, the following conditions may be satisfied: IN12/f is more than or equal to 0.01 and less than or equal to 0.20. Therefore, the chromatic aberration of the lens is improved to improve the performance of the lens.

The second lens and the third lens are spaced apart by a distance IN23 on the optical axis, which satisfies the following condition: 0< IN23/f is less than or equal to 0.25. Preferably, the following conditions may be satisfied: IN23/f is more than or equal to 0.01 and less than or equal to 0.20. Thereby contributing to improved lens performance.

The third lens and the fourth lens are separated by a distance IN34 on the optical axis, which satisfies the following condition: 0< IN34/f is less than or equal to 5. Preferably, the following conditions may be satisfied: IN34/f is more than or equal to 0.001 and less than or equal to 0.20. Thereby contributing to improved lens performance.

The thicknesses of the first lens and the second lens on the optical axis are TP1 and TP2 respectively, which satisfy the following conditions: (TP1+ IN12)/TP2 is more than or equal to 1 and less than or equal to 10. Therefore, the method helps to control the manufacturing sensitivity of the optical imaging system and improve the performance of the optical imaging system.

The thicknesses of the third lens and the fourth lens on the optical axis are TP3 and TP4, respectively, and the distance between the two lenses on the optical axis is IN34, which satisfies the following conditions: (TP4+ IN34)/TP3 is more than or equal to 1 and less than or equal to 10. Thereby, it is helpful to control the sensitivity of the optical imaging system and reduce the total height of the system.

The second lens and the third lens are separated by a distance IN23 on the optical axis, and the total distance between the first lens and the fourth lens on the optical axis is Σ TP, which satisfies the following condition: IN23/(TP2+ IN23+ TP3) is not less than 0.01 but not more than 0.5. Preferably, the following conditions may be satisfied: IN23/(TP2+ IN23+ TP3) is not less than 0.05 but not more than 0.4. Therefore, the aberration generated in the process of incident light advancing is slightly corrected layer by layer, and the total height of the system is reduced.

The utility model discloses an among the optical imaging system, fourth lens object side 142 is at the horizontal displacement distance of the optical axis at the maximum effective radius position of the on-axis point of intersect to fourth lens object side 142 and is inRS41 (if horizontal displacement is towards the image side, inRS41 is the positive value; if horizontal displacement is towards the thing side, inRS41 is the negative value), fourth lens is like the point of intersect to fourth lens of image side 144 on the optical axis and is inRS42 at the horizontal displacement distance of the optical axis to the maximum effective radius position of fourth lens of image side 144, fourth lens 140 is TP4 at the on-axis thickness, it satisfies following condition: -1 mm. ltoreq. InRS 41. ltoreq.1 mm; -1 mm. ltoreq. InRS 42. ltoreq.1 mm; more than or equal to 1mm | InRS41 | + | InRS42 | is less than or equal to 2 mm; 0.01-10 of InRS 41/TP 4; 0.01-InRS 42-TP 4-10. Therefore, the maximum effective radius position between the two surfaces of the fourth lens can be controlled, and the aberration correction of the peripheral field of view of the optical imaging system is facilitated and the miniaturization of the optical imaging system is effectively maintained.

The utility model discloses an among the optical imaging system, fourth lens object side represents with SGI411 with the parallel horizontal displacement distance of optical axis between the point of inflection of the most recent optical axis of the nodical of the on-axis of optical axis to fourth lens object side, fourth lens image side represents with SGI421 with the parallel horizontal displacement distance of optical axis between the point of inflection of the most recent optical axis of the nodical of the on-axis of optical axis to fourth lens image side, and it satisfies the following condition: 0< SGI411/(SGI411+ TP4) < 0.9; 0< SGI421/(SGI421+ TP4) ≦ 0.9. Preferably, the following conditions may be satisfied: 0.01< SGI411/(SGI411+ TP4) < 0.7; 0.01< SGI421/(SGI421+ TP4) ≦ 0.7.

A horizontal displacement distance parallel to the optical axis between an intersection point of the object-side surface of the fourth lens on the optical axis and an inflection point of the object-side surface of the fourth lens second near the optical axis is represented by SGI412, and a horizontal displacement distance parallel to the optical axis between an intersection point of the image-side surface of the fourth lens on the optical axis and an inflection point of the image-side surface of the fourth lens second near the optical axis is represented by SGI422, which satisfies the following conditions: 0< SGI412/(SGI412+ TP4) ≦ 0.9; 0< SGI422/(SGI422+ TP4) ≦ 0.9. Preferably, the following conditions may be satisfied: SGI412/(SGI412+ TP4) is more than or equal to 0.1 and less than or equal to 0.8; SGI422/(SGI422+ TP4) is more than or equal to 0.1 and less than or equal to 0.8.

The vertical distance between the inflection point of the nearest optical axis of the object side surface of the fourth lens and the optical axis is represented by HIF411, the vertical distance between the inflection point of the nearest optical axis of the image side surface of the fourth lens and the optical axis from the intersection point of the image side surface of the fourth lens on the optical axis to the image side surface of the fourth lens is represented by HIF421, and the following conditions are satisfied: HIF411/HOI is more than or equal to 0.01 and less than or equal to 0.9; HIF421/HOI is more than or equal to 0.01 and less than or equal to 0.9. Preferably, the following conditions may be satisfied: HIF411/HOI is more than or equal to 0.09 and less than or equal to 0.5; HIF421/HOI is more than or equal to 0.09 and less than or equal to 0.5.

The vertical distance between the second near-optical-axis inflection point of the object-side surface of the fourth lens and the optical axis is denoted by HIF412, and the vertical distance between the second near-optical-axis inflection point of the image-side surface of the fourth lens on the optical axis and the optical axis from the intersection point of the image-side surface of the fourth lens to the image-side surface of the fourth lens is denoted by HIF422, which satisfies the following conditions: HIF412/HOI 0.01 ≤ 0.9; HIF422/HOI is not less than 0.01 but not more than 0.9. Preferably, the following conditions may be satisfied: HIF412/HOI is more than or equal to 0.09 and less than or equal to 0.8; HIF422/HOI is more than or equal to 0.09 and less than or equal to 0.8.

The vertical distance between the third inflection point near the optical axis of the object-side surface of the fourth lens and the optical axis is HIF413, and the vertical distance between the intersection point on the optical axis of the image-side surface of the fourth lens and the third inflection point near the optical axis of the image-side surface of the fourth lens and the optical axis is HIF423, which satisfies the following conditions: 0.001mm ≦ HIF413 ≦ 5 mm; 0.001mm ≦ HIF423 ≦ 5 mm. Preferably, the following conditions may be satisfied: 0.1mm < l HIF423 > 3.5 mm; and | HIF413 | of 0.1mm is less than or equal to 3.5 mm.

The vertical distance between the fourth optical axis-approaching inflection point of the object-side surface of the fourth lens element and the optical axis is denoted by HIF414, and the vertical distance between the fourth optical axis-approaching inflection point of the image-side surface of the fourth lens element and the optical axis from the intersection point of the image-side surface of the fourth lens element and the optical axis is denoted by HIF424, wherein the following conditions are satisfied: 0.001mm ≦ HIF414 ≦ 5 mm; 0.001mm ≦ HIF424 ≦ 5 mm. Preferably, the following conditions may be satisfied: 0.1mm ≦ HIF424 ≦ 3.5 mm; 0.1mm ≦ HIF414 ≦ 3.5 mm.

The present invention provides an optical imaging system, which can be used to correct chromatic aberration of the optical imaging system by staggering the lenses with high and low dispersion coefficients.

The equation for the above aspheric surface is:

z＝ch²/[1+[1-(k+1)c²h²]^0.5]+A4h⁴+A6h⁶+A8h⁸+A10h¹⁰+A12h¹²+A14h¹⁴+A16h¹⁶+ A18h¹⁸+A20h²⁰+…(1)

where z is a position value referenced to a surface vertex at a position of height h in the optical axis direction, k is a cone coefficient, c is an inverse of a curvature radius, and a4, a6, A8, a10, a12, a14, a16, a18, and a20 are high-order aspheric coefficients.

The utility model provides an among the optical imaging system, the material of lens can be for plastics (plastic) or glass. When the lens is made of plastic, the production cost and the weight can be effectively reduced. In addition, when the lens is made of glass, the thermal effect can be controlled and the design space for the refractive power configuration of the optical imaging system can be increased. In addition, the object side and the image side of first lens to fourth lens among the optical imaging system can be the aspheric surface, and it can obtain more control variable, except that being used for subducing the aberration, compare in the use of traditional glass lens and can reduce the number that the lens used even, consequently can effectively reduce the utility model discloses optical imaging system's overall height.

In addition, in the optical imaging system provided by the present invention, if the lens surface is a convex surface, it means that the lens surface is a convex surface at the paraxial region; if the lens surface is concave, it means that the lens surface is concave at the paraxial region.

Additionally, the utility model discloses an among the optical imaging system, can set up an at least diaphragm according to the demand to reduce stray light, help promoting image quality.

The utility model discloses an optical imaging system more visual demand is applied to in the optical system that removes and focus to have good aberration concurrently and revise and good imaging quality's characteristic, thereby enlarge the application aspect.

The utility model discloses a more visual demand of optical imaging system includes a drive module, and this drive module can be coupled with each lens and make each lens produce the displacement. The driving module may be a Voice Coil Motor (VCM) for driving the lens to focus, or an optical hand vibration prevention assembly (OIS) for reducing the frequency of out-of-focus caused by lens vibration during the photographing process.

The utility model discloses a more visual demand of optical imaging system makes in first lens, second lens, third lens, the fourth lens at least one lens be the light filtering subassembly that the wavelength is less than 500nm, and it can borrow by the at least one coating film on the surface of the lens of this specific utensil filtering function or this lens itself by the utensil can filter out short wavelength's material and make and reach.

The utility model discloses a more visual demand of imaging surface of optical imaging system selects to a plane or a curved surface. The imaging plane is a curved surface (e.g., a spherical surface with a radius of curvature), which helps to reduce the incident angle required for focusing light on the imaging plane, and helps to improve the relative illumination in addition To The Length (TTL) of the miniature optical imaging system.

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

First embodiment

Referring to fig. 1 to fig. 3, wherein fig. 1 is a schematic diagram of an optical imaging system according to a first embodiment of the present invention, and fig. 2 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the first embodiment from left to right. Fig. 3 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan, the longest operating wavelength and the shortest operating wavelength of the optical imaging system of the first embodiment passing through the aperture edge at the 0.7 field. In fig. 1, the optical imaging system 10 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, an ir-filter 170, an image plane 180, and an image sensor 190.

The first lens element 110 with positive refractive power has a convex object-side surface 112 and a concave image-side surface 114, and is aspheric, and the object-side surface 112 and the image-side surface 114 both have an inflection point. The profile curve length for the maximum effective radius of the object-side surface of the first lens is denoted as ARS11 and the profile curve length for the maximum effective radius of the image-side surface of the first lens is denoted as ARS 12. The contour curve length for the 1/2 entrance pupil diameter (HEP) of the object-side surface of the first lens is denoted as ARE11, and the contour curve length for the 1/2 entrance pupil diameter (HEP) of the image-side surface of the first lens is denoted as ARE 12. The first lens has a thickness TP1 on the optical axis.

The horizontal displacement distance parallel to the optical axis between the intersection point of the object-side surface of the first lens on the optical axis and the inflection point of the nearest optical axis of the object-side surface of the first lens is represented by SGI111, and the horizontal displacement distance parallel to the optical axis between the intersection point of the image-side surface of the first lens on the optical axis and the inflection point of the nearest optical axis of the image-side surface of the first lens is represented by SGI121, which satisfies the following conditions: SGI 111-0.2008 mm; SGI121 ═ 0.0113 mm; -SGI 111 |/(| SGI111 | + TP1) | -0.3018; | SGI121 |/(| SGI121 | + TP1) | 0.0238.

The vertical distance between the optical axis and the inflection point of the optical axis intersection point of the object-side surface of the first lens to the nearest optical axis of the object-side surface of the first lens is represented by HIF111, and the vertical distance between the optical axis and the inflection point of the optical axis intersection point of the optical axis of the image-side surface of the first lens to the nearest optical axis of the image-side surface of the first lens is represented by HIF121, which satisfies the following conditions: HIF 111-0.7488 mm; HIF 121-0.4451 mm; HIF111/HOI 0.2552; HIF121/HOI 0.1517.

The second lens element 120 with positive refractive power has a concave object-side surface 122 and a convex image-side surface 124, and is aspheric, and the object-side surface 122 has an inflection point. The profile curve length for the maximum effective radius of the object-side surface of the second lens is denoted as ARS21 and the profile curve length for the maximum effective radius of the image-side surface of the second lens is denoted as ARS 22. The contour curve length for the 1/2 entrance pupil diameter (HEP) of the object-side surface of the second lens is denoted as ARE21, and the contour curve length for the 1/2 entrance pupil diameter (HEP) of the image-side surface of the second lens is denoted as ARE 22. The second lens has a thickness TP2 on the optical axis.

The horizontal displacement distance parallel to the optical axis between the intersection point of the object-side surface of the second lens on the optical axis and the inflection point of the nearest optical axis of the object-side surface of the second lens is represented by SGI211, and the horizontal displacement distance parallel to the optical axis between the intersection point of the image-side surface of the second lens on the optical axis and the inflection point of the nearest optical axis of the image-side surface of the second lens is represented by SGI221, which satisfies the following conditions: SGI211 ═ -0.1791 mm; | SGI211 |/(| SGI211 | + TP2) | -0.3109.

The vertical distance between the optical axis and the inflection point of the optical axis intersection point of the object-side surface of the second lens to the nearest optical axis of the object-side surface of the second lens is represented by HIF211, and the vertical distance between the optical axis and the inflection point of the optical axis intersection point of the image-side surface of the second lens to the nearest optical axis of the image-side surface of the second lens is represented by HIF221, which satisfies the following conditions: HIF 211-0.8147 mm; HIF211/HOI 0.2777.

The third lens element 130 with negative refractive power has a concave object-side surface 132 and a convex image-side surface 134, and is aspheric, and the image-side surface 134 has an inflection point. The maximum effective radius of the object-side surface of the third lens has a profile curve length represented by ARS31 and the maximum effective radius of the image-side surface of the third lens has a profile curve length represented by ARS 32. The contour curve length for the 1/2 entrance pupil diameter (HEP) of the object-side surface of the third lens is denoted as ARE31, and the contour curve length for the 1/2 entrance pupil diameter (HEP) of the image-side surface of the third lens is denoted as ARE 32. The third lens has a thickness TP3 on the optical axis.

The horizontal displacement distance parallel to the optical axis between the intersection point of the object-side surface of the third lens on the optical axis and the inflection point of the nearest optical axis of the object-side surface of the third lens is represented by SGI311, and the horizontal displacement distance parallel to the optical axis between the intersection point of the image-side surface of the third lens on the optical axis and the inflection point of the nearest optical axis of the image-side surface of the third lens is represented by SGI321, which satisfies the following conditions: SGI 321-0.1647 mm; -SGI 321 |/(| SGI321 | + TP3) — 0.1884.

The vertical distance between the inflection point of the nearest optical axis of the object-side surface of the third lens and the optical axis is represented by HIF311, the vertical distance between the inflection point of the nearest optical axis of the image-side surface of the third lens and the optical axis is represented by HIF321, and the following conditions are satisfied: HIF 321-0.7269 mm; HIF321/HOI 0.2477.

The fourth lens element 140 with negative refractive power has a convex object-side surface 142 and a concave image-side surface 144, and is aspheric, wherein the object-side surface 142 has two inflection points and the image-side surface 144 has one inflection point. The profile curve length for the maximum effective radius of the object-side surface of the fourth lens is denoted as ARS41 and the profile curve length for the maximum effective radius of the image-side surface of the fourth lens is denoted as ARS 42. The contour curve length of the 1/2 entrance pupil diameter (HEP) of the object-side surface of the fourth lens is denoted as ARE41, and the contour curve length of the 1/2 entrance pupil diameter (HEP) of the image-side surface of the fourth lens is denoted as ARE 42. The thickness of the fourth lens on the optical axis is TP 4.

The horizontal displacement distance parallel to the optical axis between the intersection point of the object-side surface of the fourth lens on the optical axis and the inflection point of the nearest optical axis of the object-side surface of the fourth lens is represented by SGI411, and the horizontal displacement distance parallel to the optical axis between the intersection point of the image-side surface of the fourth lens on the optical axis and the inflection point of the nearest optical axis of the image-side surface of the fourth lens is represented by SGI421, which satisfies the following conditions: SGI411 ═ 0.0137 mm; SGI421 ═ 0.0922 mm; -SGI 411 |/(| SGI411 | + TP4) ═ 0.0155; | SGI421 |/(| SGI421 | + TP4) | -0.0956.

A horizontal displacement distance parallel to the optical axis between an intersection of the fourth lens object-side surface on the optical axis to a second inflection point of the fourth lens object-side surface proximate the optical axis is indicated at SGI412, which satisfies the following condition: SGI412 ═ -0.1518 mm; | SGI412 |/(| SGI412 | + TP4) | -0.1482.

The vertical distance between the inflection point of the nearest optical axis of the object-side surface of the fourth lens and the optical axis is represented by HIF411, and the vertical distance between the inflection point of the nearest optical axis of the image-side surface of the fourth lens and the optical axis is represented by HIF411, which satisfies the following conditions: HIF411 mm 0.2890 mm; HIF421 of 0.5794 mm; HIF411/HOI ═ 0.0985; HIF421/HOI 0.1975.

The vertical distance between the inflection point of the second paraxial region of the object-side surface of the fourth lens and the optical axis is denoted by HIF412, which satisfies the following conditions: HIF412 ═ 1.3328 mm; HIF412/HOI 0.4543.

The infrared filter 170 is made of glass, and is disposed between the fourth lens element 140 and the image plane 180 without affecting the focal length of the optical imaging system.

In the optical imaging system of the first embodiment, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, and half of the maximum angle of view in the optical imaging system is HAF, which has the following values: 3.4375 mm; f/HEP is 2.23; and HAF 39.69 degrees and tan (HAF) 0.8299.

In the optical imaging system of the first embodiment, the focal length of the first lens 110 is f1, and the focal length of the fourth lens 140 is f4, which satisfies the following conditions: f1 is 3.2736 mm; | f/f1 | -1.0501; f 4-8.3381 mm; and | f1/f4 | -0.3926.

In the optical imaging system of the first embodiment, the focal lengths of the second lens 120 to the third lens 130 are f2 and f3, respectively, which satisfy the following conditions: | f2 | + -f 3 | -10.0976 mm; | f1 | + | f4 | _ 11.6116mm and | f2 | + f3 | f1 | + | f4 |.

In the optical imaging system of the first embodiment, the sum of the PPRs of all the lenses with positive refractive power is Σ PPR | f/f1 | + | f/f2 | -1.95585, and the sum of the NPRs of all the lenses with negative refractive power is Σ NPR | -f/f 3 | + | f/f4 | -0.95770, and Σ PPR/| NPR | -2.04224. The following conditions are also satisfied: | f/f1 | -1.05009; | f/f2 | -0.90576; | f/f3 | -0.54543; | f/f4 | -0.41227.

In the optical imaging system of the first embodiment, a distance between the object-side surface 112 of the first lens element and the image-side surface 144 of the fourth lens element is InTL, a distance between the object-side surface 112 of the first lens element and the image plane 180 of the first lens element is HOS, a distance between the aperture stop 100 and the image plane 180 of the first lens element is InS, a half of a diagonal length of an effective sensing area of the image sensor 190 is HOI, and a distance between the image-side surface 144 of the fourth lens element and the image plane 180 of the fourth lens element is InB, which satisfies the following conditions: instl + InB ═ HOS; HOS 4.4250 mm; HOI 2.9340 mm; HOS/HOI 1.5082; HOS/f 1.2873; 0.7191 for InTL/HOS; 4.2128mm for InS; and InS/HOS 0.95204.

In the optical imaging system of the first embodiment, the sum of the thicknesses of all the lenses with refractive power on the optical axis is Σ TP, which satisfies the following condition: Σ TP is 2.4437 mm; and Σ TP/intil 0.76793. Therefore, the contrast of system imaging and the yield of lens manufacturing can be considered simultaneously, and a proper back focal length is provided for accommodating other components.

In the optical imaging system of the first embodiment, the radius of curvature of the object-side surface 112 of the first lens is R1, and the radius of curvature of the image-side surface 114 of the first lens is R2, which satisfies the following conditions: R1/R2 | -0.1853. Therefore, the first lens element has proper positive refractive power strength, and the spherical aberration is prevented from increasing and speeding up.

In the optical imaging system of the first embodiment, the radius of curvature of the object-side surface 142 of the fourth lens is R7, and the radius of curvature of the image-side surface 144 of the fourth lens is R8, which satisfies the following conditions: (R7-R8)/(R7+ R8) ═ 0.2756. Therefore, astigmatism generated by the optical imaging system is favorably corrected.

In the optical imaging system of the first embodiment, the respective focal lengths of the first lens element 110 and the second lens element 120 are f1 and f2, respectively, and the sum of the focal lengths of all the lens elements with positive refractive power is Σ PP, which satisfies the following condition: f1+ f2 is 7.0688 mm; and f1/(f1+ f2) ═ 0.4631. Therefore, the positive refractive power of the first lens element 110 can be properly distributed to other positive lens elements, so as to suppress the occurrence of significant aberration during the incident light traveling process.

In the optical imaging system of the first embodiment, the respective focal lengths of the third lens element 130 and the fourth lens element 140 are f3 and f4, respectively, and the sum of the focal lengths of all the lens elements with negative refractive power is Σ NP, which satisfies the following condition: Σ NP ═ f3+ f4 ═ -14.6405 mm; and f4/(f2+ f4) ═ 0.5695. Therefore, the negative refractive power of the fourth lens element can be properly distributed to the other negative lens elements, so as to suppress the occurrence of significant aberration during the incident light beam traveling process.

IN the optical imaging system of the first embodiment, the first lens 110 and the second lens 120 are separated by a distance IN12 on the optical axis, which satisfies the following condition: IN 12-0.3817 mm; IN12/f 0.11105. Therefore, the chromatic aberration of the lens is improved to improve the performance of the lens.

IN the optical imaging system of the first embodiment, the second lens 120 is separated from the third lens 130 by the distance IN23 on the optical axis, which satisfies the following condition: IN 23-0.0704 mm; IN23/f 0.02048. Therefore, the chromatic aberration of the lens is improved to improve the performance of the lens.

IN the optical imaging system of the first embodiment, the third lens 130 and the fourth lens 140 are separated by a distance IN34 on the optical axis, which satisfies the following condition: IN 34-0.2863 mm; IN34/f 0.08330. Therefore, the chromatic aberration of the lens is improved to improve the performance of the lens.

In the optical imaging system of the first embodiment, the thicknesses of the first lens 110 and the second lens 120 on the optical axis are TP1 and TP2, respectively, which satisfy the following conditions: TP 1-0.46442 mm; TP 2-0.39686 mm; TP1/TP2 ═ 1.17023 and (TP1+ IN12)/TP2 ═ 2.13213. Therefore, the method helps to control the manufacturing sensitivity of the optical imaging system and improve the performance of the optical imaging system.

IN the optical imaging system of the first embodiment, the thicknesses of the third lens 130 and the fourth lens 140 on the optical axis are TP3 and TP4, respectively, and the distance between the two lenses on the optical axis is IN34, which satisfies the following conditions: TP 3-0.70989 mm; TP 4-0.87253 mm; TP3/TP4 ═ 0.81359 and (TP4+ IN34)/TP3 ═ 1.63248. Thereby, it is helpful to control the sensitivity of the optical imaging system and reduce the total height of the system.

In the optical imaging system of the first embodiment, the following conditions are satisfied: IN23/(TP2+ IN23+ TP3) 0.05980. Therefore, the optical fiber is beneficial to slightly correcting aberration generated in the process of incident light advancing layer by layer and reducing the total height of the system.

In the optical imaging system of the first embodiment, the horizontal displacement distance on the optical axis from the intersection point of the fourth lens object-side surface 142 on the optical axis to the maximum effective radius position of the fourth lens object-side surface 142 is InRS41, the horizontal displacement distance on the optical axis from the intersection point of the fourth lens image-side surface 144 on the optical axis to the maximum effective radius position of the fourth lens image-side surface 144 is InRS42, and the thickness of the fourth lens 140 on the optical axis is TP4, which satisfies the following conditions: InRS 41-0.23761 mm; InRS 42-0.20206 mm; | InRS41 | + | InRS42 | 0.43967 mm; | InRS41 |/TP 4 ═ 0.27232; and | InRS42 |/TP 4 ═ 0.23158. Therefore, the lens is beneficial to manufacturing and molding and effectively maintains the miniaturization.

In the optical imaging system of the present embodiment, the perpendicular distance between the critical point C41 of the object-side surface 142 of the fourth lens element and the optical axis is HVT41, and the perpendicular distance between the critical point C42 of the image-side surface 144 of the fourth lens element and the optical axis is HVT42, which satisfies the following conditions: HVT41 ═ 0.5695 mm; HVT42 ═ 1.3556 mm; HVT41/HVT 42-0.4201. Therefore, the aberration of the off-axis field can be effectively corrected.

The optical imaging system of the embodiment satisfies the following conditions: HVT42/HOI 0.4620. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

The optical imaging system of the embodiment satisfies the following conditions: HVT42/HOS 0.3063. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

In the optical imaging system of the first embodiment, the first lens has an abbe number NA1, the second lens has an abbe number NA2, the third lens has an abbe number NA3, and the fourth lens has an abbe number NA4, and the following conditions are satisfied: -NA 1-NA 2-0; NA3/NA2 0.39921. Therefore, the correction of the chromatic aberration of the optical imaging system is facilitated.

In the optical imaging system of the first embodiment, the TV distortion at the time of image formation of the optical imaging system is TDT, and the optical distortion at the time of image formation is ODT, which satisfy the following conditions: | TDT | -0.4%; and | ODT | -2.5%.

In the optical imaging system of the present embodiment, the lateral aberration of 0.7 field of view incident on the imaging plane through the aperture edge at the longest operating wavelength of the positive meridional fan map is represented by PLTA, which is 0.001mm (Pixel Size is 1.12 μm), the lateral aberration of 0.7 field of view incident on the imaging plane through the aperture edge at the shortest operating wavelength of the positive meridional fan map is represented by PSTA, which is 0.004mm (Pixel Size is 1.12 μm), the lateral aberration of 0.7 field of view incident on the imaging plane through the aperture edge at the longest operating wavelength of the negative meridional fan map is represented by NLTA, which is 0.003mm (Pixel Size is 1.12 μm), and the lateral aberration of 0.7 field of view incident on the imaging plane through the aperture edge at the shortest operating wavelength of the negative meridional fan map is represented by NSTA, which is-0.003 mm (Pixel Size is 1.12 μm). The lateral aberration of the 0.7 field of view of the longest operating wavelength of the sagittal fan map incident on the imaging plane through the aperture edge is denoted by SLTA and is 0.003mm (Pixel Size is 1.12 μm), and the lateral aberration of the 0.7 field of view of the shortest operating wavelength of the sagittal fan map incident on the imaging plane through the aperture edge is denoted by SSTA and is 0.004mm (Pixel Size is 1.12 μm).

The following list I and list II are referred to cooperatively.

TABLE II aspherical coefficients of the first example

Values associated with the profile curve length can be obtained according to table one and table two:

the first embodiment is a detailed structural data of the first embodiment, wherein the units of the radius of curvature, the thickness, the distance, and the focal length are mm, and the surfaces 0-14 sequentially represent the surfaces from the object side to the image side. Table II shows aspheric data of the first embodiment, where k represents the cone coefficients in the aspheric curve equation, and A1-A20 represents the aspheric coefficients of order 1-20 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 is not repeated herein.

Second embodiment

Referring to fig. 4 to 6, wherein fig. 4 is a schematic view of an optical imaging system according to a second embodiment of the present invention, and fig. 5 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the second embodiment from left to right. Fig. 6 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan, the longest operating wavelength and the shortest operating wavelength of the optical imaging system of the second embodiment passing through the aperture edge at the 0.7 field. In fig. 4, the optical imaging system 20 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, an ir-filter 270, an image plane 280 and an image sensor 290.

The first lens element 210 with negative refractive power has a concave object-side surface 212 and a concave image-side surface 214, and is aspheric, and the object-side surface 212 has an inflection point.

The second lens element 220 with positive refractive power has a convex object-side surface 222 and a concave image-side surface 224, and is aspheric, and the object-side surface 222 has an inflection point.

The third lens element 230 with positive refractive power has a convex object-side surface 232 and a convex image-side surface 234, and is aspheric, and the object-side surface 232 has an inflection point.

The fourth lens element 240 with negative refractive power has a convex object-side surface 242 and a concave image-side surface 244, and is aspheric, and the object-side surface 242 has an inflection point.

The infrared filter 270 is made of glass, and is disposed between the fourth lens element 240 and the image plane 280 without affecting the focal length of the optical imaging system.

Please refer to the following table three and table four.

TABLE IV aspheric coefficients of the second embodiment

In the second embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment, and are not described herein again.

According to the third table and the fourth table, the following conditional expressions can be obtained:

the values associated with the profile curve length can be obtained according to table three and table four:

third embodiment

Referring to fig. 7 to 9, wherein fig. 7 is a schematic view of an optical imaging system according to a third embodiment of the present invention, and fig. 8 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the third embodiment from left to right. Fig. 9 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan, the longest operating wavelength and the shortest operating wavelength of the optical imaging system of the third embodiment passing through the aperture edge at the 0.7 field. In fig. 7, the optical imaging system 30 includes, in order from an object side to an image side, a first lens element 310, an aperture stop 300, a second lens element 320, a third lens element 330, a fourth lens element 340, an ir-filter 370, an image plane 380, and an image sensor assembly 390.

The first lens element 310 with negative refractive power has a convex object-side surface 312 and a concave image-side surface 314.

The second lens element 320 with positive refractive power has a convex object-side surface 322 and a convex image-side surface 324.

The third lens element 330 with positive refractive power has a concave object-side surface 332 and a convex image-side surface 334, and is made of glass.

The fourth lens element 340 with positive refractive power has a convex object-side surface 342 and a concave image-side surface 344.

The infrared filter 370 is made of glass, and is disposed between the fourth lens element 340 and the image plane 380 without affecting the focal length of the optical imaging system.

Please refer to table five and table six below.

TABLE sixth, aspherical coefficients of the third example

In the third embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment, and are not described herein again.

According to table five and table six, the following conditional values can be obtained:

the values related to the profile curve length can be obtained according to table five and table six:

fourth embodiment

Referring to fig. 10 to 12, wherein fig. 10 is a schematic view of an optical imaging system according to a fourth embodiment of the present invention, and fig. 11 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the fourth embodiment from left to right. Fig. 12 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan, the longest operating wavelength and the shortest operating wavelength of the optical imaging system of the fourth embodiment passing through the aperture edge at the 0.7 field. In fig. 10, the optical imaging system 40 includes, in order from an object side to an image side, a first lens element 410, an aperture stop 400, a second lens element 420, a third lens element 430, a fourth lens element 440, an ir-filter 470, an image plane 480 and an image sensor 490.

The first lens element 410 with negative refractive power has a concave object-side surface 412 and a concave image-side surface 414, which are both aspheric, and has an inflection point on an object-side surface 442.

The second lens element 420 with positive refractive power has a convex object-side surface 422 and a convex image-side surface 424, and is aspheric, and the object-side surface 422 has an inflection point.

The third lens element 430 with negative refractive power has a convex object-side surface 432 and a concave image-side surface 434, and is aspheric, and the object-side surface 432 has two inflection points.

The fourth lens element 440 with positive refractive power has a concave object-side surface 442 and a convex image-side surface 444, and both the object-side surface 442 and the image-side surface 444 have inflection points.

The ir filter 470 is made of glass, and is disposed between the fourth lens element 440 and the image plane 480 without affecting the focal length of the optical imaging system.

Please refer to table seven and table eight below.

TABLE eighth, fourth example aspherical surface coefficients

In the fourth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment, and are not described herein again.

According to the seventh and eighth tables, the following conditional values can be obtained:

values related to the profile curve length can be obtained according to table seven and table eight:

fifth embodiment

Referring to fig. 13 to 15, wherein fig. 13 is a schematic view of an optical imaging system according to a fifth embodiment of the present invention, and fig. 14 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the fifth embodiment from left to right. Fig. 15 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan of the optical imaging system of the fifth embodiment, the longest operating wavelength and the shortest operating wavelength passing through the aperture edge at 0.7 field. In fig. 13, the optical imaging system includes, in order from an object side to an image side, a first lens element 510, an aperture stop 500, a second lens element 520, a third lens element 530, a fourth lens element 540, an ir-pass filter 570, an image plane 580, and an image sensor 590.

The first lens element 510 with negative refractive power has a convex object-side surface 512 and a concave image-side surface 514, and is made of glass.

The second lens element 520 with positive refractive power has a convex object-side surface 522 and a concave image-side surface 524, and is made of glass.

The third lens element 530 with positive refractive power has a convex object-side surface 532 and a convex image-side surface 534 and is made of glass.

The fourth lens element 540 with positive refractive power has a convex object-side surface 542 and a convex image-side surface 544, and is made of glass.

The infrared filter 570 is made of glass, and is disposed between the fourth lens element 540 and the image plane 580 without affecting the focal length of the optical imaging system.

Please refer to table nine and table ten below.

Aspherical surface coefficients of Table ten and fifth example

In the fifth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment, and are not described herein again.

The following conditional values are obtained according to table nine and table ten:

values associated with the profile curve length can be obtained according to table nine and table ten:

sixth embodiment

Referring to fig. 16 to 18, wherein fig. 16 is a schematic view of an optical imaging system according to a sixth embodiment of the present invention, and fig. 17 is a graph sequentially showing a spherical aberration, an astigmatism and an optical distortion of the optical imaging system of the sixth embodiment from left to right. Fig. 18 is a lateral aberration diagram of the meridional plane fan and sagittal plane fan, the longest operating wavelength and the shortest operating wavelength of the optical imaging system of the sixth embodiment passing through the aperture edge at the 0.7 field. In fig. 16, the optical imaging system 60 includes, in order from an object side to an image side, a first lens element 610, an aperture stop 600, a second lens element 620, a third lens element 630, a fourth lens element 640, an ir-filter 670, an image plane 680 and an image sensor assembly 690.

The first lens element 610 with negative refractive power has a convex object-side surface 612 and a concave image-side surface 614, and is aspheric, and the object-side surface 612 has an inflection point.

The second lens element 620 with positive refractive power has a convex object-side surface 622 and a convex image-side surface 624, and is aspheric, and the object-side surface 622 has an inflection point.

The third lens element 630 with positive refractive power has a concave object-side surface 632, a convex image-side surface 634, and an inflection point on both the object-side surface 632 and the image-side surface 634.

The fourth lens element 640 with negative refractive power has a convex object-side surface 642 and a concave image-side surface 644, which are both aspheric, and has an inflection point on an object-side surface 632 and two inflection points on an image-side surface 634.

The infrared filter 670 is made of glass, and is disposed between the fourth lens element 640 and the image plane 680 without affecting the focal length of the optical imaging system.

Please refer to the following table eleven and table twelve.

TABLE twelfth and sixth examples of aspherical surface coefficients

In the sixth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment, and are not described herein again.

The following conditional values were obtained according to table eleven and table twelve:

values associated with the profile curve length are obtained according to table eleven and table twelve:

although the present invention has been described with reference to the above embodiments, it is not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and therefore the scope of the present invention should be determined by the scope of the appended claims.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Claims

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

a first lens element with negative refractive power;

a second lens element with positive refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power; and

an imaging plane;

wherein the number of the optical imaging system having four lens elements with refractive power is four, and the third lens element or the fourth lens element has negative refractive power, focal lengths of the first to fourth lenses are f1, f2, f3, f4, respectively, the focal length of the optical imaging system is f, the diameter of the entrance pupil of the optical imaging system is HEP, the first lens object-side surface has a distance HOS on the optical axis to the image plane, the first lens object-side surface has a distance InTL on the optical axis to the fourth lens image-side surface, half of the maximum viewing angle of the optical imaging system is HAF, the intersection of any surface of any one of the lenses with the optical axis is a starting point, a coordinate point along the contour of the surface up to a vertical height on the surface from the diameter of the entrance pupil of the optical axis 1/2 is an end point, and the length of the contour curve between the two points is ARE, which satisfies the following conditions: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

2. The optical imaging system of claim 1,

the optical imaging system has a TV distortion at the time of image-combining of TDT, wherein the optical imaging system has a maximum imaging height HOI on the imaging plane perpendicular to the optical axis, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by PLTA, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by PSTA, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by NLTA, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by NSTA, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by SLTA, a transverse aberration at 0.7HOI on the imaging plane through the entrance pupil edge is denoted by sagittal fan through SLTA, the transverse aberration of the sagittal plane light fan, at a shortest operating wavelength of 0.7HOI through the entrance pupil edge and incident on the imaging plane, is denoted SSTA, which satisfies the following condition: PLTA is less than or equal to 100 microns; PSTA not more than 100 microns; NLTA is less than or equal to 100 micrometers; NSTA is less than or equal to 100 microns; SLTA is less than or equal to 100 microns; and SSTA of less than or equal to 100 microns; TDT | is < 100%.

3. The optical imaging system of claim 1,

the maximum effective radius of any surface of any one of the lenses is expressed by EHD, the intersection point of any surface of any one of the lenses and the optical axis is taken as a starting point, the contour of the surface is taken as an end point until the maximum effective radius of the surface, the length of the contour curve between the two points is ARS, and the following formula is satisfied: 0.9-2.0 of ARS/EHD.

4. The optical imaging system of claim 1,

the optical imaging system satisfies the following formula: HOS is more than 0mm and less than or equal to 50 mm.

5. The optical imaging system of claim 1,

the imaging surface is selected to be a plane or a curved surface.

6. The optical imaging system of claim 1,

an intersection point of an object-side surface of the fourth lens on the optical axis is a starting point, an intersection point of an image-side surface of the fourth lens on the optical axis along a contour of the surface up to a coordinate point on the surface at a vertical height from an entrance pupil diameter of an optical axis 1/2 is an end point, a contour curve length between the two points is ARE41, an intersection point of an image-side surface of the fourth lens on the optical axis is a starting point, an intersection point of an image-side surface of the fourth lens on the surface up to a coordinate point on the surface at a vertical height from an entrance pupil diameter of an optical axis 1/2 is an end point, a contour curve length between the two points is ARE42, and a thickness of the fourth lens on the optical axis is TP4, which satisfy the following conditions: ARE41/TP4 of 0.05-25; and 0.05. ltoreq. ARE42/TP 4. ltoreq.25.

7. The optical imaging system of claim 1,

an intersection point of the object-side surface of the third lens on the optical axis is a starting point, an intersection point of the image-side surface of the third lens on the optical axis along the contour of the surface up to a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 is an end point, a contour curve length between the two points is ARE31, an intersection point of the image-side surface of the third lens on the optical axis along the contour of the surface up to a coordinate point on the surface at a vertical height from the entrance pupil diameter of the optical axis 1/2 is an end point, a contour curve length between the two points is ARE32, and a thickness of the third lens on the optical axis is TP3, which satisfy the following conditions: ARE31/TP3 of 0.05-25; and 0.05. ltoreq. ARE32/TP 3. ltoreq.25.

8. The optical imaging system of claim 1,

further comprising an aperture and having a distance InS on the optical axis from the aperture to the image plane, which satisfies the following formula: 0.2-1.1 of InS/HOS.

9. An optical imaging system, comprising, in order from an object side to an image side:

a first lens element with negative refractive power;

a second lens element with positive refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power; and

an imaging plane;

wherein the optical imaging system has four lenses with refractive power, at least one surface of at least one of the first lens element to the fourth lens element has at least one inflection point, and the third lens element or the fourth lens element has negative refractive power, focal lengths of the first lens element to the fourth lens element are f1, f2, f3 and f4, respectively, the focal length of the optical imaging system is f, an entrance pupil diameter of the optical imaging system is HEP, a distance HOS is provided on an optical axis from an object-side surface of the first lens element to an image-side surface of the fourth lens element, a distance inll is provided on the optical axis from the object-side surface of the first lens element to the image-side surface of the fourth lens element, half of a maximum viewing angle of the optical imaging system is HAF, an intersection point of any one of the lenses with the optical axis is a starting point, and a coordinate point along a contour of the surfaces up to a vertical height on the surface from the entrance pupil diameter of the optical axis 1/2 is an end point, the length of the profile curve between the two points is ARE, which satisfies the following condition: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

10. The optical imaging system of claim 9,

the maximum effective radius of any surface of any lens in each lens is expressed by EHD, the intersection point of any surface of any lens in each lens and the optical axis is taken as a starting point, the contour of the surface is taken as an end point until the maximum effective radius of the surface, the length of the contour curve between the two points is ARS, and the following formula is satisfied: 0.9-2.0 of ARS/EHD.

11. The optical imaging system of claim 9,

at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point.

12. The optical imaging system of claim 9,

the optical imaging system has a maximum imaging height HOI perpendicular to an optical axis on the imaging plane, a lateral aberration at 0.7HOI through the entrance pupil edge and incident on the imaging plane of a positive meridional light fan of the optical imaging system is denoted by PLTA, a lateral aberration at 0.7HOI through the entrance pupil edge and incident on the imaging plane of a shortest operating wavelength of a negative meridional light fan is denoted by PSTA, a lateral aberration at 0.7HOI through the entrance pupil edge and incident on the imaging plane of a longest operating wavelength of a negative meridional light fan is denoted by NLTA, a lateral aberration at 0.7HOI through the entrance pupil edge and incident on the imaging plane of a shortest operating wavelength of a negative meridional light fan is denoted by NSTA, a lateral aberration at 0.7HOI through the entrance pupil edge and incident on the imaging plane of a longest operating wavelength of a sagittal light fan is denoted by SLTA, the transverse aberration of the sagittal plane light fan, at a shortest operating wavelength of 0.7HOI through the entrance pupil edge and incident on the imaging plane, is denoted SSTA, which satisfies the following condition: PLTA is less than or equal to 50 microns; PSTA not more than 50 microns; NLTA is less than or equal to 50 microns; NSTA is less than or equal to 50 microns; SLTA is less than or equal to 50 microns; and SSTA of less than or equal to 50 microns.

13. The optical imaging system of claim 9,

a distance on an optical axis between the first lens and the second lens is IN12, and satisfies the following formula: 0< IN12/f is less than or equal to 60.

14. The optical imaging system of claim 9,

a distance on an optical axis between the third lens and the fourth lens is IN34, and satisfies the following formula: 0< IN34/f is less than or equal to 5.

15. The optical imaging system of claim 9,

the distance between the third lens and the fourth lens on the optical axis is IN34, the thicknesses of the third lens and the fourth lens on the optical axis are TP3 and TP4 respectively, and the following conditions are satisfied: (TP4+ IN34)/TP3 is more than or equal to 1 and less than or equal to 10.

16. The optical imaging system of claim 9,

the distance between the first lens and the second lens on the optical axis is IN12, the thicknesses of the first lens and the second lens on the optical axis are TP1 and TP2 respectively, and the following conditions are satisfied: (TP1+ IN12)/TP2 is more than or equal to 1 and less than or equal to 10.

17. The optical imaging system of claim 9,

at least one of the first lens, the second lens, the third lens and the fourth lens is a light filtering component with the wavelength less than 500 nm.

18. An optical imaging system, comprising, in order from an object side to an image side:

a first lens element with negative refractive power;

a second lens element with positive refractive power;

a third lens element with refractive power;

the fourth lens element with refractive power has at least one inflection point on at least one of an object-side surface and an image-side surface thereof; and

an imaging plane;

wherein the optical imaging system has four lenses with refractive power and the third lens or the fourth lens has negative refractive power, at least one surface of at least one of the first lens to the third lens has at least one inflection point, focal lengths of the first lens to the fourth lens are f1, f2, f3 and f4, respectively, the focal length of the optical imaging system is f, an entrance pupil diameter of the optical imaging system is HEP, a distance HOS is provided on an optical axis from the object side surface of the first lens to the image side surface of the fourth lens, a distance InTL is provided on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens, a half of a maximum visual angle of the optical imaging system is HAF, an intersection point of any surface of any lens in each lens and the optical axis is a starting point, a coordinate point along a contour of the surface up to a vertical height on the surface from the entrance pupil diameter of the optical axis 1/2 is an end point, the length of the profile curve between the two points is ARE, which satisfies the following condition: f/HEP is more than or equal to 1 and less than or equal to 10; HAF less than 0deg and less than or equal to 150deg and ARE/HEP less than or equal to 0.9 and less than or equal to 2.0.

19. The optical imaging system of claim 18,

20. The optical imaging system of claim 18,

21. The optical imaging system of claim 18,

22. The optical imaging system of claim 18,

23. The optical imaging system of claim 18,

the optical imaging system further comprises an aperture, an image sensing element and a driving module, wherein the image sensing element is arranged on the imaging surface, a distance InS is formed between the aperture and the imaging surface, and the driving module is coupled with each lens and enables each lens to generate displacement, and the following formulas are satisfied: 0.2-1.1 of InS/HOS.