TWI650589B - Optical imaging system (2) - Google Patents

Abstract

An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens in this order from the object side to the image side. At least one of the first to sixth lenses has a positive refractive power. The seventh lens may have a negative refractive power, and both surfaces thereof are aspherical, and at least one surface of the seventh lens has a point of inflection. The lenses with refractive power in the optical imaging system are the first lens to the seventh lens. When certain conditions are met, it can have greater light collection and better light path adjustment capabilities to improve imaging quality.

Description

Optical imaging system (2)

The invention relates to an optical imaging system group, and more particularly to a miniaturized optical imaging system group applied to electronic products.

In recent years, with the rise of portable electronic products with photographic functions, the demand for optical systems has been increasing. The photosensitive elements of general optical systems are nothing more than two types: photosensitive coupled device (CCD) or complementary metal-Oxide Semiconductor sensor (CMOS sensor), and with the advancement of semiconductor process technology, The pixel size of the photosensitive element is reduced, and the optical system is gradually developed in the high pixel field, so the requirements for imaging quality are also increasing.

Traditionally, the optical system mounted on portable devices mainly uses five or six lens structures. However, as portable devices continue to improve pixel quality and end consumers ’demands for large apertures such as low light and night light Shooting function, the conventional optical imaging system has been unable to meet higher-level photography requirements.

Therefore, how to effectively increase the amount of light entering the optical imaging lens and further improve the imaging quality has become a very important issue.

The aspect of the embodiment of the present invention is directed to an optical imaging system and an optical image capturing lens, which can use the combination of the refractive power of seven lenses, a convex surface, and a concave surface (the convex surface or concave surface in the present invention refers to the object side of each lens in principle). Or like the description of the change of the geometric shape at different heights from the optical axis to the side), which can effectively increase the amount of light entering the optical imaging system and improve the imaging quality at the same time, so that it can be applied to small electronic products.

In addition, in specific optical imaging applications, there is a need to target both visible light and Light sources with infrared wavelengths, such as IP video surveillance cameras. The "Day & Night" feature of IP video surveillance cameras is mainly because human visible light is located in the spectrum of 400-700nm, but the imaging of the sensor includes human invisible infrared light, so in order to ensure that The sensor finally retains only the visible light of the human eye. If necessary, a removable IR cut filter (ICR) is set in front of the lens to increase the "realism" of the image, which can eliminate infrared during the daytime. Light and avoid color shift; let infrared light come in at night to increase brightness. However, the ICR element itself occupies a considerable volume and is expensive, which is disadvantageous for the design and manufacture of future miniature surveillance cameras.

The aspect of the embodiment of the present invention is directed to an optical imaging system and an optical image capturing lens. The refractive power of seven lenses, the combination of convex and concave surfaces, and the selection of materials can be used to make the optical imaging system focus on visible light and infrared light. The gap between the imaging focal lengths is reduced, that is, it is close to the "confocal" effect, so there is no need to use ICR components.

The terms of the lens parameters and their codes related to the embodiments of the present invention are listed in detail below as a reference for subsequent descriptions:

Lens parameters related to the magnification of optical imaging systems and optical image capture lenses

The optical imaging system and the optical image capturing lens of the present invention can also be designed for biometric identification, such as facial recognition. If the embodiment of the present invention is used for image capture of face recognition, infrared light may be used as the working wavelength. At the same time, for faces with a distance of about 25 to 30 cm and a width of about 15 cm, it can be applied to the photosensitive element (pixel size 1.4 micrometers (μm)) at least 30 horizontal pixels are imaged in the horizontal direction. The linear magnification of the infrared imaging surface is LM, which meets the following conditions: LM = (30 horizontal pixels) multiplied by (pixel size of 1.4 microns) divided by the width of the subject 15 cm; LM ≧ 0.0003. At the same time, visible light is used as the working wavelength. At the same time, at least 50 faces with a distance of about 25 to 30 cm and a width of about 15 cm can be imaged horizontally on a photosensitive element (pixel size is 1.4 micrometers (μm)). Horizontal pixels.

Lens parameters related to length or height

In the present invention, a wavelength of 555 nm can be selected as a main reference wavelength and a reference for measuring focus shift in the visible light spectrum, and a wavelength of 850 nm can be selected as a main reference wavelength and a reference for measuring focus shift in the infrared light spectrum (700 nm to 1300 nm).

The optical imaging system has a first imaging plane and a second imaging plane. The first imaging plane is a visible light image plane perpendicular to the optical axis, and the central field of view is a defocus modulation conversion contrast transfer rate at a first spatial frequency. (MTF) has a maximum value; and the second imaging plane is a specific perpendicular to the light The infrared light image plane of the axis and its central field of view at the first spatial frequency have a maximum defocus modulation conversion contrast transfer rate (MTF). The optical imaging system further has a first average imaging plane and a second average imaging plane. The first average imaging plane is a visible light image plane perpendicular to the optical axis and is set in the central field of view of the optical imaging system. The average position of the defocus position of the field and the 0.7 field of view each having the maximum MTF value of the field of view at the first spatial frequency; and the second average imaging plane is a specific infrared light image plane perpendicular to the optical axis and is set at The central field of view, the 0.3 field of view, and the 0.7 field of view of the optical imaging system each have an average position of an out-of-focus position having a maximum MTF value of each of the fields at a first spatial frequency.

The aforementioned first spatial frequency is set to a half of the spatial frequency (half frequency) of the photosensitive element (sensor) used in the present invention. For example, the pixel size is a photosensitive element containing 1.12 micrometers or less, and its modulation conversion function characteristic is The quarter space frequency, half space frequency (half frequency) and full space frequency (full frequency) of the figure are at least 110 cycles / mm, 220 cycles / mm, and 440 cycles / mm, respectively. The light in any field of view can be further divided into sagittal ray and tangential ray.

The focus offsets of the maximum defocus MTF of the sagittal rays of the visible light center field of view, 0.3 field of view, and 0.7 field of view of the optical imaging system of the present invention are respectively represented by VSFS0, VSFS3, and VSFS7 (unit of measurement: mm); visible light center The maximum defocus MTF of the sagittal plane rays of the field of view, 0.3 field of view, and 0.7 field of view are represented by VSMTF0, VSMTF3, and VSMTF7, respectively; the maximum defocus MTF of the meridional rays of the central field of view, 0.3 field of view, and 0.7 field of view The value of the focus offset is represented by VTFS0, VTFS3, and VTFS7 (measurement unit: mm); the maximum defocus MTF of the meridional rays of the central field of view, 0.3 field of view, and 0.7 field of view is VTMTF0, VTMTF3, and VTMTF7, respectively. Means. The average focus shift amount (position) of the aforementioned focus shift amounts of the sagittal view field of the visible light arc and the three view fields of the visible meridian plane is represented by AVFS (measurement unit: mm).

The focus offset of the maximum defocus MTF of the sagittal plane rays of the central field, the 0.3 field of view, and the 0.7 field of vision of the optical imaging system of the present invention is represented by ISFS0, ISFS3, and ISFS7, respectively. The average focus offset (position) of the focus offset is expressed in AISFS (measurement unit: mm); the maximum defocus MTF of the sagittal rays of the infrared central field, 0.3 field of view, and 0.7 field of view is ISMTF0, ISMTF3 and ISMTF7 are indicated; the focus offset of the maximum defocus MTF of the meridional rays of the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light is represented by ITFS0, ITFS3, and ITFS7 (unit of measurement: mm), the aforementioned meridian The average focus offset (position) of the focus offset of the three fields of view is represented by AITFS (unit of measurement: mm); the center of view of the infrared light, 0.3 field of view, The maximum out-of-focus MTF of the meridional light in the 0.7 field of view is represented by IMTTF0, IMTTF3, and IMTTF7, respectively. The average focus shift amount (position) of the aforementioned focus shift amounts of the sagittal three-field of the infrared light arc and the three fields of the meridional infrared light plane is represented by AIFS (unit of measurement: mm).

The focus offset between the visible light center field focus point and the infrared light center field focus point (RGB / IR) of the entire optical imaging system is represented by FS (ie, wavelength 850nm vs. wavelength 555nm, unit of measurement: mm); the entire optical The difference between the visible focus three-field average focus offset and the infrared light three-field average focus offset (RGB / IR) of the imaging system (focus offset) is expressed in AFS (that is, a wavelength of 850 nm to a wavelength of 555 nm, Unit of measurement: mm).

The maximum imaging height of the optical imaging system is represented by HOI; the height of the optical imaging system is represented by HOS; the distance between the first lens object side and the seventh lens image side of the optical imaging system is represented by InTL; the fixed light bar of the optical imaging system ( The distance from the aperture to the first imaging surface is represented by InS; the distance between the first lens and the second lens of the optical imaging system is represented by IN12 (example); the thickness of the first lens of the optical imaging system on the optical axis is represented by TP1 Display (example).

Lens parameters related to materials

The dispersion coefficient of the first lens of the optical imaging system is represented by NA1 (illustration); the refraction law of the first lens is represented by Nd1 (illustration).

Angle-dependent lens parameters

The angle of view is represented by AF; half of the angle of view is represented by HAF; the principal ray angle is represented by MRA.

Lens parameters related to exit pupil

The diameter of the entrance pupil of an optical imaging system is represented by HEP; the maximum effective radius of any surface of a single lens refers to the point where the system ’s maximum viewing angle of incident light passes through the edge of the entrance pupil at the lens surface (Effective Half Diameter; EHD), The vertical height between the intersection and the optical axis. For example, the maximum effective radius of the object side of the first lens is represented by EHD11, and the maximum effective radius of the image side of the first lens is represented by EHD12. The maximum effective radius of the object side of the second lens is represented by EHD21, and the maximum effective radius of the image side of the second lens is represented by EHD22. The maximum effective radius of any surface of the remaining lenses in the optical imaging system is expressed in the same manner.

Parameters related to lens surface depth

The intersection of the seventh lens object side on the optical axis to the end of the maximum effective radius of the seventh lens object side. The distance between the two points horizontal to the optical axis is represented by InRS71 (the maximum effective radius Depth); the intersection of the seventh lens image side on the optical axis to the end of the maximum effective radius of the seventh lens image side, the distance between the two points horizontal to the optical axis is represented by InRS72 (maximum effective radius depth). The depth (sinking amount) of the maximum effective radius of the object side or image side of other lenses is expressed in the same manner as described above.

Parameters related to lens shape

The critical point C refers to a point on a specific lens surface that is tangent to a tangent plane that is perpendicular to the optical axis except for the intersection with the optical axis. For example, the vertical distance between the critical point C51 on the object side of the fifth lens and the optical axis is HVT51 (example), the vertical distance between the critical point C52 on the image side of the fifth lens and the optical axis is HVT52 (example), and the sixth lens object The vertical distance between the critical point C61 on the side and the optical axis is HVT61 (illustrated), and the vertical distance between the critical point C62 on the side of the sixth lens image and the optical axis is HVT62 (illustrated). The critical points on the object side or the image side of other lenses, such as the seventh lens, and the vertical distance from the optical axis are expressed in the same manner as described above.

The inflection point closest to the optical axis on the object side of the seventh lens is IF711. This point has a subsidence of SGI711 (example). SGI711 is the intersection of the object side of the seventh lens on the optical axis and the closest optical axis of the object side of the seventh lens. The horizontal displacement distance between the inflection points is parallel to the optical axis. The vertical distance between this point and the optical axis is IF711 (illustration). The inflection point on the image side of the seventh lens that is closest to the optical axis is IF721. This point sinks SGI721 (for example). SGI711 is the intersection of the seventh lens image side on the optical axis and the closest optical axis of the seventh lens image side. The horizontal displacement distance between the inflection points parallel to the optical axis, and the vertical distance between this point of IF721 and the optical axis is HIF721 (illustration).

The second inflection point on the object side of the seventh lens approaching the optical axis is IF712. This point has a subsidence of SGI712 (for example). SGI712, that is, the intersection of the object side of the seventh lens on the optical axis, is the second closest to the object side of the seventh lens. The horizontal displacement distance between the inflection points of the optical axis and the optical axis is parallel. The vertical distance between this point of the IF712 and the optical axis is HIF712 (example). The second inflection point on the seventh lens image side that is close to the optical axis is IF722. This point has a subsidence of SGI722 (for example). SGI722 is the intersection of the seventh lens image side on the optical axis and the seventh lens image side is the second closest. The horizontal displacement distance between the inflection points of the optical axis and the optical axis is parallel, and the vertical distance between this point and the optical axis of IF722 is HIF722 (illustration).

The third inflection point on the object side of the seventh lens approaching the optical axis is IF713. This point has a subsidence of SGI713 (for example). SGI713, that is, the intersection of the object side of the seventh lens on the optical axis is the third closest to the object side of the seventh lens The horizontal displacement distance between the inflection points of the optical axis and the optical axis is parallel, and the vertical distance between this point and the optical axis of IF713 is HIF713 (illustration). The inflection point of the third lens close to the optical axis on the image side of the seventh lens is IF723, this point subsidence SGI723 (for example), SGI723 is the horizontal displacement distance parallel to the optical axis between the intersection of the seventh lens image side on the optical axis and the third lens image side third inflection point close to the optical axis The vertical distance between this point of IF723 and the optical axis is HIF723 (example).

The inflection point of the fourth lens close to the optical axis on the seventh lens object side is IF714. This point has a subsidence of SGI714 (for example). SGI714, that is, the intersection of the seventh lens object side on the optical axis and the seventh lens object side is fourth closer. The horizontal displacement distance between the inflection points of the optical axis is parallel to the optical axis. The vertical distance between this point and the optical axis of IF714 is HIF714 (illustration). The inflection point on the seventh lens image side close to the optical axis is IF724, which is the amount of subsidence SGI724 (for example). SGI724, that is, the intersection of the seventh lens image side on the optical axis to the seventh lens image side fourth approach The horizontal displacement distance between the inflection points of the optical axis and the optical axis is parallel. The vertical distance between this point and the optical axis of IF724 is HIF724 (illustration).

The inflection points on the object side or image side of other lenses and their vertical distance from the optical axis or the amount of their subsidence are expressed in the same manner as described above.

Aberration-related variables

Optical Distortion of an optical imaging system is represented by ODT; its TV Distortion is represented by TDT, and the degree of aberration shift between 50% and 100% of the field of view can be further defined; spherical aberration bias The amount of shift is expressed in DFS; the amount of comet aberration shift is expressed in DFC.

The Modulation Transfer Function (MTF) of the optical imaging system is used to test and evaluate the contrast and sharpness of the imaging system. The vertical coordinate axis of the modulation transfer function characteristic graph represents the contrast transfer rate (values from 0 to 1), and the horizontal coordinate axis represents the spatial frequency (cycles / mm; lp / mm; line pairs per mm). The perfect imaging system can theoretically show the line contrast of the subject. However, the actual imaging system has a contrast ratio of less than 1 on the vertical axis. In addition, generally, it is more difficult to obtain a fine degree of reduction in the edge area of the imaging than in the center area. The visible light spectrum is on the first imaging plane. The optical axis, 0.3 field of view, and 0.7 field of view are at the spatial frequency of 55 cycles / mm. The contrast transfer rates (MTF values) are respectively expressed as MTFE0, MTFE3, and MTFE7. The optical axis, 0.3 field of view, and The contrast transfer rate (MTF value) of 0.7 field of view III at the spatial frequency of 110 cycles / mm is represented by MTFQ0, MTFQ3, and MTFQ7, respectively. (Values) are expressed as MTFH0, MTFH3, and MTFH7, respectively. The contrast transfer rates (MTF values) of the optical axis, 0.3 field of view, and 0.7 field of view at the spatial frequency of 440 cycles / mm are expressed as MTF0, MTF3, and MTF7, respectively. These three fields of view are representative of the center of the lens, the inner field of view, and the outer field of view, so they can be used to evaluate whether the performance of a particular optical imaging system is excellent. If the design of the optical imaging system corresponds to a pixel size with a photosensitive element below 1.12 microns, the quarter space frequency, half space frequency (half frequency), and full space frequency ( Full frequency) are at least 110 cycles / mm, 220 cycles / mm and 440 cycles / mm.

If the optical imaging system must also meet the imaging for the infrared spectrum, such as night vision for low light sources, the working wavelength can be 850nm or 800nm. Since the main function is to identify the contours of objects formed by black and white, there is no need for high resolution Therefore, it is only necessary to select a spatial frequency of less than 110 cycles / mm to evaluate whether the performance of a specific optical imaging system in the infrared spectrum is excellent. When the working wavelength of 850 nm is focused on the second imaging surface, the contrast transfer rates (MTF values) of the image at the optical axis, 0.3 field of view, and 0.7 field of view at a spatial frequency of 55 cycles / mm are represented by MTFI0, MTFI3, and MTFI7, respectively. However, because the working wavelength of infrared light at 850nm or 800nm is far from the wavelength of visible light, if the optical imaging system needs to be able to focus both visible light and infrared (dual-mode) at the same time and achieve certain performance, it is quite difficult to design.

The invention provides an optical imaging system, which can simultaneously focus visible light and infrared (dual-mode) and achieve a certain performance, and the seventh lens has an inflection point on the object or image side, which can effectively adjust the incidence of each field of view. The angle of the seventh lens is corrected for optical distortion and TV distortion. In addition, the surface of the seventh lens may have better light path adjustment capabilities to improve imaging quality.

According to the present invention, an optical imaging system is provided, which includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a first imaging surface in this order from the object side to the image side. And a second imaging plane. The first imaging plane is a specific visible light image plane perpendicular to the optical axis, and the central field of view has a maximum defocus modulation conversion contrast transfer rate (MTF) at the first spatial frequency; the second imaging plane is a specific vertical The defocus modulation conversion contrast transfer rate (MTF) of the infrared light image plane at the optical axis and its central field of view at the first spatial frequency has a maximum value. Each of the first to seventh lenses has a refractive power. The focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, f7, the focal length of the optical imaging system is f, and the entrance pupil diameter of the optical imaging system is HEP. There is a distance HOS on the optical axis from the side of the lens object to the first imaging plane. Half of the maximum viewing angle of the optical imaging system is HAF. The optical imaging system has a maximum imaging perpendicular to the optical axis on the first imaging plane. Height HOI, the first imaging plane and the The distance between the second imaging plane on the optical axis is FS, and the thicknesses of the first lens to the seventh lens at a height of 1/2 HEP and parallel to the optical axis are ETP1, ETP2, ETP3, ETP4, ETP5, ETP6 and ETP7, the sum of the aforementioned ETP1 to ETP7 is SETP, the thicknesses of the first lens to the seventh lens on the optical axis are TP1, TP2, TP3, TP4, TP5, TP6 and TP7, and the sum of the aforementioned TP1 to TP7 is STP, It satisfies the following conditions: 1.0 ≦ f / HEP ≦ 10.0; 0deg <HAF ≦ 150deg; 0.2 ≦ SETP / STP <1, and | FS | ≦ 60 μm.

According to the present invention, there is also provided an optical imaging system, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a first image from the object side to the image side. Surface and a second imaging surface. The first imaging plane is a specific visible light image plane perpendicular to the optical axis, and the central field of view has a maximum defocus modulation conversion contrast transfer rate (MTF) at the first spatial frequency; the second imaging plane is a specific vertical The defocus modulation conversion contrast transfer rate (MTF) of the infrared light image plane at the optical axis and its central field of view at the first spatial frequency has a maximum value. The first lens has a refractive power, and the object side may be a convex surface near the optical axis. The second lens has a refractive power. The third lens has a refractive power. The fourth lens has a refractive power. The fifth lens has a refractive power. The sixth lens has a refractive power. The seventh lens has a refractive power. The optical imaging system has a maximum imaging height HOI perpendicular to the optical axis on the first imaging surface, and at least one of the first lens to the seventh lens is made of glass, and the first lens to the seventh lens are made of glass. At least one of the lenses has a positive refractive power, and the focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, and f7, the focal length of the optical imaging system is f, and the optical imaging system The entrance pupil diameter is HEP, the distance from the object side of the first lens to the first imaging plane is HOS on the optical axis, half of the maximum viewing angle of the optical imaging system is HAF, and the optical imaging system is on the first imaging The plane has a maximum imaging height HOI perpendicular to the optical axis, the distance between the first imaging plane and the second imaging plane on the optical axis is FS, and the coordinate point on the object side of the first lens at a height of 1/2 HEP The horizontal distance from the first imaging plane parallel to the optical axis is ETL, the coordinate point on the object side of the first lens at a height of 1/2 HEP to the coordinate point on the image side of the seventh lens at a height of 1/2 HEP The horizontal distance between two parallel to the optical axis is EIN, the first At least one of the mirror to the seventh lens is made of glass, which satisfies the following conditions: it satisfies the following conditions: 1 ≦ f / HEP ≦ 10; 0deg <HAF ≦ 150deg; 0.2 ≦ EIN / ETL <1 and | FS ｜ ≦ 60 μm.

According to the present invention, there is further provided an optical imaging system, which sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a first average from the object side to the image side. An imaging plane and a second average imaging plane. The first average imaging plane is a visible light image plane perpendicular to the optical axis and is arranged in the central field of view, the field of view of 0.3, and the field of view of 0.7 of the optical imaging system. Each of the first spatial frequencies has a maximum MTF of the field of view. The average position of the defocus position of the value; the second average imaging plane is a specific infrared light image plane perpendicular to the optical axis and is set in the central field of view, 0.3 field of view, and 0.7 field of view of the optical imaging system. The spatial frequencies all have an average position of the out-of-focus position of the maximum MTF value of the field of view. The optical imaging system has seven lenses having a refractive power, and the optical imaging system has a maximum imaging height HOI perpendicular to the optical axis on the first average imaging plane. The first lens has a refractive power. The second lens has a refractive power. The third lens has a refractive power. The fourth lens has a refractive power. The fifth lens has a refractive power. The sixth lens has a refractive power. The seventh lens has a refractive power. The focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, f7, the focal length of the optical imaging system is f, and the entrance pupil diameter of the optical imaging system is HEP. There is a distance HOS on the optical axis from the side of the lens object to the first average imaging plane. Half of the maximum viewing angle of the optical imaging system is HAF. The optical imaging system has a distance perpendicular to the optical axis on the first average imaging plane. Maximum imaging height HOI, the intersection of any surface of any of these lenses with the optical axis is the starting point, and extends the contour of the surface to the coordinate point on the surface at a vertical height of 1/2 of the entrance pupil diameter from the optical axis So far, the length of the contour curve between the two points is ARE, the distance between the first average imaging surface and the second average imaging surface is AFS, and the first lens to the seventh lens are at a height of 1/2 HEP and parallel to The thickness of the optical axis is ETP1, ETP2, ETP3, ETP4, ETP5, ETP6, and ETP7. The sum of the aforementioned ETP1 to ETP7 is SETP. The thicknesses of the first lens to the seventh lens on the optical axis are TP1, TP2, TP3. , TP4, TP5, TP6, and TP7, the aforementioned TP The sum of 1 to TP7 is STP. At least one of the first lens to the seventh lens is made of glass, which meets the following conditions: 1.0 ≦ f / HEP ≦ 10.0; 0deg <HAF ≦ 150deg; 0.2 ≦ SETP / STP < 1 and | AFS | ≦ 60 μm.

The infrared light has a wavelength between 700 nm and 1300 nm and the first spatial frequency is represented by SP1, which meets the following conditions: SP1 ≦ 440 cycles / mm.

The thickness of a single lens at the height of 1/2 incident pupil diameter (HEP), especially affects the correction aberrations of the common field of each ray field of view within the range of the 1/2 incident pupil diameter (HEP) and the optical path difference between the rays of each field of view. The greater the thickness, the greater the ability to correct aberrations. However, it will also increase the difficulty of production. Therefore, it is necessary to control the thickness of a single lens at a height of 1/2 incident pupil diameter (HEP), especially to control the lens at The proportional relationship (ETP / TP) between the thickness (ETP) of the 1/2 entrance pupil diameter (HEP) height and the thickness (TP) on the optical axis of the lens to which the surface belongs. For example, the thickness of the first lens at a height of 1/2 the entrance pupil diameter (HEP) is represented by ETP1. The thickness of the second lens at a height of 1/2 the entrance pupil diameter (HEP) is expressed as ETP2. The thickness of the remaining lenses in the optical imaging system at a height of ½ the entrance pupil diameter (HEP), and so on. The sum of the aforementioned ETP1 to ETP7 is SETP, and the embodiment of the present invention can satisfy the following formula: 0.3 ≦ SETP / EIN <1.

In order to balance the ability to correct aberrations and reduce manufacturing difficulties, it is particularly necessary to control the thickness (ETP) of the lens at 1/2 the height of the entrance pupil diameter (HEP) and the thickness of the lens on the optical axis (TP ) (ETP / TP). For example, the thickness of the first lens at 1/2 the height of the entrance pupil diameter (HEP) is represented by ETP1, the thickness of the first lens on the optical axis is TP1, and the ratio between the two is ETP1 / TP1. The thickness of the second lens at 1/2 the height of the entrance pupil diameter (HEP) is represented by ETP2, the thickness of the second lens on the optical axis is TP2, and the ratio between the two is ETP2 / TP2. The proportional relationship between the thickness of the other lenses in the optical imaging system at the height of 1/2 of the entrance pupil diameter (HEP) and the thickness (TP) of the lens on the optical axis, and the expressions are deduced by analogy. The embodiment of the present invention can satisfy the following formula: 0.2 ≦ ETP / TP ≦ 3.

The horizontal distance between two adjacent lenses at a height of 1/2 incident pupil diameter (HEP) is represented by ED. The aforementioned horizontal distance (ED) is parallel to the optical axis of the optical imaging system, and particularly affects the 1/2 incident pupil diameter (HEP). The ability to correct aberrations in the common area of the field of view of each ray and the optical path difference between the rays of each field of view. The greater the horizontal distance, the greater the possibility of correcting the aberration, but at the same time it will increase production difficulties And the degree to which the length of the optical imaging system is "miniaturized", it is necessary to control the horizontal distance (ED) of the two adjacent lenses at 1/2 the height of the entrance pupil diameter (HEP).

In order to balance the ability to improve the ability to correct aberrations and reduce the difficulty of the "miniaturization" of the length of the optical imaging system, it is particularly necessary to control the horizontal distance (ED) of the two adjacent lenses at the height of 1/2 incident pupil diameter (HEP) and the The proportional relationship (ED / IN) between the horizontal distance (IN) of two adjacent lenses on the optical axis. For example, the horizontal distance between the first lens and the second lens at a height of 1/2 incident pupil diameter (HEP) is represented by ED12, and the horizontal distance between the first lens and the second lens on the optical axis is IN12, and the ratio between the two is ED12. / IN12. The horizontal distance between the second lens and the third lens at 1/2 the height of the entrance pupil diameter (HEP) is represented by ED23. The horizontal distance between the second lens and the third lens on the optical axis is IN23, and the ratio between the two is ED23 / IN23. The proportional relationship between the horizontal distance of the remaining two adjacent lenses at the height of 1/2 incident pupil diameter (HEP) and the horizontal distance of the adjacent two lenses on the optical axis in the optical imaging system, and the expressions are deduced by analogy.

The horizontal distance from the coordinate point on the image side of the seventh lens at a height of 1/2 HEP to the first imaging plane parallel to the optical axis is EBL, and the intersection of the seventh lens image side and the optical axis to the first imaging plane The horizontal distance of the plane parallel to the optical axis is BL. In the embodiment of the present invention, the ability to correct aberrations and reserve the space for other optical elements are weighed at the same time, which can satisfy the following formula: 0.2 ≦ EBL / BL <1.5. The optical imaging system may further include a filter element, the filter element is located between the seventh lens and the first imaging surface, and the coordinate point on the image side of the seventh lens at a height of 1/2 HEP to the filter element The distance between the seventh lens parallel to the optical axis and the optical axis is PIR. The distance between the seventh lens and the optical element parallel to the optical axis is PIR. The embodiment of the present invention can satisfy the following formula: 0.1 ≦ EIR /PIR≦1.1.

When | f1 |> | f7 |, the total height of the optical imaging system (HOS; Height of Optic System) can be appropriately shortened to achieve the purpose of miniaturization.

At least one of the second lens to the sixth lens has a weak positive refractive power or a weak negative refractive power. The so-called weak refractive power means that the absolute value of the focal length of a particular lens is greater than 10mm. When at least one of the second to sixth lenses of the present invention has a weak positive refractive power, it can effectively share the positive refractive power of the first lens and prevent unnecessary aberrations from appearing prematurely. If at least one of the six lenses has a weak negative refractive power, the aberrations of the correction system can be fine-tuned.

In addition, the seventh lens may have a negative refractive power, and its image side may be concave. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, at least one surface of the seventh lens may have at least one inflection point, which can effectively suppress the incident angle of the off-axis field of view, and further correct the aberration of the off-axis field of view.

10, 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

114, 214, 314, 414, 514, 614‧‧‧ like side

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

122, 222, 322, 422, 522, 622

124, 224, 324, 424, 524, 624‧‧‧ like side

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

132, 232, 332, 432, 532, 632

134, 234, 334, 434, 534, 634 ‧ ‧ like side

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

142, 242, 342, 442, 542, 642

144, 244, 344, 444, 544, 644‧‧‧ like side

150, 250, 350, 450, 550, 650‧‧‧ fifth lens

152, 252, 352, 452, 552, 652

154, 254, 354, 454, 554, 654‧‧‧ like side

160, 260, 360, 460, 560, 660‧‧‧ Sixth lens

162, 262, 362, 462, 562, 662

164, 264, 364, 464, 564, 664‧‧‧ like side

170, 270, 370, 470, 570, 670‧‧‧ seventh lens

172, 272, 372, 472, 572, 672

174, 274, 374, 474, 574, 674‧‧‧

180, 280, 380, 480, 580, 680‧‧‧ infrared filter

190, 290, 390, 490, 590, 690‧‧‧ first imaging plane

192, 292, 392, 492, 592, 692‧‧‧ image sensor

f‧‧‧ focal length of optical imaging system

f1‧‧‧ focal length of the first lens

f2‧‧‧ focal length of the second lens

f3‧‧‧ focal length of the third lens

f4‧‧‧ focal length of the fourth lens

f5‧‧‧ the focal length of the fifth lens

f6‧‧‧ focal length of the sixth lens

f7‧‧‧ focal length of the seventh lens

f / HEP; Fno; F # ‧‧‧ aperture value of optical imaging system

HAF‧‧‧half of the maximum viewing angle of optical imaging system

NA1‧‧‧The dispersion coefficient of the first lens

NA2, NA3, NA4, NA5, NA6, NA7‧The dispersion coefficient of the second lens to the seventh lens

R1, R2‧The curvature radius of the object side and the image side of the first lens

R3, R4‧The curvature radius of the object side and the image side of the second lens

R5, R6‧The curvature radius of the object side and image side of the third lens

R7, R8‧The curvature radius of the object side and image side of the fourth lens

R9, R10‧The curvature radius of the object side and image side of the fifth lens

R11, R12‧The curvature radius of the object side and image side of the sixth lens

R13, R14‧‧‧ seventh lens object side surface and a ^{radius of} curvature of the image side surface

TP1‧‧‧thickness of the first lens on the optical axis

TP2, TP3, TP4, TP5, TP6, TP7‧thickness of the second to seventh lenses on the optical axis

Σ TP‧‧‧ Total thickness of all refractive lenses

IN12‧‧‧ The distance between the first lens and the second lens on the optical axis

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

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

IN45‧‧‧ The distance between the fourth lens and the fifth lens on the optical axis

IN56‧‧‧The distance between the fifth lens and the sixth lens on the optical axis

IN67‧‧‧ The distance between the sixth lens and the seventh lens on the optical axis

InRS71‧‧‧ Horizontal displacement distance from the intersection of the seventh lens object side on the optical axis to the maximum effective radius position of the seventh lens object side on the optical axis

IF711‧‧‧The inflection point closest to the optical axis on the object side of the seventh lens

SGI711‧‧‧The amount of subsidence at this point

HIF711‧‧‧The vertical distance between the inflection point closest to the optical axis on the object side of the seventh lens and the optical axis

IF721‧‧‧The closest inflection point on the image side of the seventh lens closest to the optical axis

SGI721‧‧‧The amount of subsidence at this point

HIF721‧The vertical distance between the inflection point of the seventh lens image closest to the optical axis and the optical axis

IF712‧‧‧The second inflection point on the object side of the seventh lens near the optical axis

SGI712‧‧‧ Subsidence at this point

HIF712‧‧‧The vertical distance between the second curved point near the optical axis and the optical axis on the object side of the seventh lens

IF722‧‧‧The second inflection point on the image side of the seventh lens close to the optical axis

SGI722‧‧‧ Subsidence

HIF722‧‧‧ The vertical distance between the second curved point near the optical axis of the seventh lens image side and the optical axis

C71‧‧‧ critical point of the object side of the seventh lens

C72‧‧‧ critical point of the image side of the seventh lens

SGC71‧‧‧Horizontal displacement distance between the critical point of the object side of the seventh lens and the optical axis

SGC72‧The critical distance of the image side of the seventh lens and the horizontal displacement distance of the optical axis

HVT71‧‧‧The vertical distance between the critical point of the seventh lens and the optical axis

HVT72‧‧‧ The vertical distance between the critical point of the image side of the seventh lens and the optical axis

HOS‧‧‧ total system height (distance from the first lens object side to the first imaging plane on the optical axis)

InS‧‧‧ Distance from aperture to first imaging plane

InTL‧‧‧The distance from the object side of the first lens to the image side of the seventh lens

InB‧‧‧The distance from the image side of the seventh lens to the first imaging plane

HOI‧‧‧ half of the diagonal length of the effective sensing area of the image sensing element (maximum image height)

TDT‧‧‧TV Distortion of Optical Imaging System

ODT‧‧‧Optical Distortion of Optical Imaging System

The above and other features of the present invention will be described in detail with reference to the drawings.

FIG. 1A is a schematic diagram illustrating an optical imaging system according to a first embodiment of the present invention; FIG. Figure 1B shows the spherical aberration, astigmatism, and optical distortion of the optical imaging system of the first embodiment of the present invention in order from left to right. Figure 1C shows the optical imaging system of the first embodiment of the present invention. Visible light spectrum modulation conversion characteristic diagram; FIG. 1D is a diagram illustrating the defocus modulation conversion contrast transfer rate (Through Focus MTF) of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum of the first embodiment of the present invention; Figure 1E is a diagram showing the center-of-field, 0.3-field, and 0.7-field defocus modulation conversion contrast transfer rates of the first embodiment of the present invention; and Figure 2A is a diagram showing the second embodiment of the present invention. Schematic diagram of an optical imaging system; FIG. 2B shows the spherical aberration, astigmatism, and optical distortion curves of the optical imaging system of the second embodiment of the present invention in order from left to right; FIG. 2C shows the second embodiment of the present invention. The characteristic chart of visible light spectrum modulation conversion of the optical imaging system of the embodiment; FIG. 2D is a diagram showing the defocus modulation conversion contrast transfer rate of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum of the second embodiment of the present invention; Figure 2E illustrates the invention The center field of view, 0.3 field of view, and 0.7 field of view of the second embodiment of the defocus modulation conversion contrast transfer rate diagram; FIG. 3A is a schematic diagram showing the optical imaging system of the third embodiment of the present invention; Figure 3B shows the spherical aberration, astigmatism, and optical distortion of the optical imaging system of the third embodiment of the present invention in order from left to right. Figure 3C shows visible light of the optical imaging system of the third embodiment of the present invention. Characteristic diagram of spectrum modulation conversion; FIG. 3D is a diagram showing the defocus modulation conversion contrast transfer rate of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum of the third embodiment of the present invention; FIG. 3E is a diagram showing the defocus modulation conversion contrast transfer rate of the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light spectrum according to the third embodiment of the present invention; FIG. 4A is a view showing the fourth embodiment of the present invention A schematic diagram of an optical imaging system; FIG. 4B shows the spherical aberration, astigmatism, and optical distortion curves of the fourth embodiment of the optical imaging system in order from left to right; FIG. 4C shows the first embodiment of the present invention. The characteristic diagram of visible light spectrum modulation conversion of the optical imaging system of the fourth embodiment; FIG. 4D is a diagram showing the defocus modulation conversion contrast transfer rate of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum of the fourth embodiment of the present invention Figure 4E is a diagram showing the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light spectrum in accordance with the fourth embodiment of the present invention with defocus modulation conversion contrast transfer rate; Figure 5A is a diagram showing the fifth implementation of the present invention A schematic diagram of the optical imaging system of the example; FIG. 5B shows the spherical aberration, astigmatism, and optical distortion of the optical imaging system of the fifth embodiment of the present invention in order from left to right; FIG. 5C shows the present invention Fifth Embodiment Visible of Optical Imaging System Characteristic diagram of spectral modulation conversion; FIG. 5D is a diagram showing the contrast ratio of defocus modulation conversion of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum of the fifth embodiment of the present invention; FIG. 5E is a drawing In the fifth embodiment of the invention, the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light spectrum are compared with the defocus modulation conversion and transfer rate diagram; FIG. 6A is a schematic diagram showing an optical imaging system according to a sixth embodiment of the present invention; FIG. 6B shows the spherical aberration, astigmatism, and optical distortion of the optical imaging system of the sixth embodiment of the present invention in order from left to right. FIG. 6C shows the optical imaging system of the sixth embodiment of the present invention. Visible light spectrum modulation conversion characteristics Figure 6D is a diagram showing the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum in accordance with the sixth embodiment of the present invention with defocus modulation conversion contrast transfer rate; Figure 6E is a sixth embodiment of the present invention Example: Defocus modulation conversion vs. transfer rate graph for the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light spectrum.

An optical imaging system group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and a first lens having a refractive power in order from the object side to the image side. Imaging surface. The optical imaging system may further include an image sensing element disposed on the first imaging plane, and the imaging height approaches 3.91 mm in the following embodiments.

The optical imaging system can be designed using three working wavelengths, which are 486.1nm, 587.5nm, and 656.2nm, of which 587.5nm is the main reference wavelength and the reference wavelength for the main extraction technical features. The optical imaging system can also be designed using five working wavelengths, which are 470nm, 510nm, 555nm, 610nm, and 650nm, of which 555nm is the main reference wavelength and the reference wavelength for the main extraction technical features.

The ratio of the focal length f of the optical imaging system to the focal length fp of each lens with positive refractive power PPR, the ratio of the focal length f of the optical imaging system to the focal length fn of each lens with negative refractive power NPR, all lenses with positive refractive power The sum of PPR is Σ PPR, and the sum of NPR of all lenses with negative refractive power is Σ NPR. It helps to control the total refractive power and total length of the optical imaging system when the following conditions are met: 0.5 ≦ Σ PPR / ｜ Σ NPR ｜ ≦ 15. Preferably, the following conditions can be satisfied: 1 ≦ Σ PPR / | Σ NPR | ≦ 3.0.

The optical imaging system may further include an image sensing element disposed on the first imaging surface. The half of the diagonal length of the effective sensing area of the image sensing element (that is, the imaging height or maximum image height of the optical imaging system) is HOI, and the distance from the first lens object side to the first imaging surface on the optical axis is HOS , Which satisfies the following conditions: HOS / HOI ≦ 10; and 0.5 ≦ HOS / f ≦ 10. Preferably, the following conditions can be satisfied: 1 ≦ HOS / HOI ≦ 5; and 1 ≦ HOS / f ≦ 7. Thereby, the miniaturization of the optical imaging system can be maintained to be mounted on a thin and light portable electronic product.

In addition, in the optical imaging system of the present invention, at least one aperture can be set as required, To reduce stray light, help improve image quality.

In the optical imaging system of the present invention, the aperture configuration may be a front aperture or a middle aperture, wherein the front aperture means that the aperture is set between the subject and the first lens, and the middle aperture means that the aperture is set between the first lens and the first lens. Between the first imaging planes. If the aperture is a front aperture, the exit pupil of the optical imaging system and the first imaging plane can have a longer distance to accommodate more optical elements, and increase the efficiency of the image sensing element to receive images; if the aperture is a middle aperture This system can help to expand the field of view of the system, so that the optical imaging system has the advantages of a wide-angle lens. The distance from the aforementioned aperture to the image side of the sixth lens is InS, which satisfies the following conditions: 0.2 ≦ InS / HOS ≦ 1.1. This makes it possible to achieve both the miniaturization of the optical imaging system and the characteristics of having a wide angle.

In the optical imaging system of the present invention, the distance between the object side of the first lens and the image side of the seventh lens is InTL, and the total thickness of all lenses with refractive power on the optical axis is Σ TP, which satisfies the following conditions: 0.1 ≦ Σ TP / InTL ≦ 0.9. Thereby, the contrast of the system imaging and the yield of lens manufacturing can be taken into account at the same time, and an appropriate back focus can be provided to accommodate other components.

The curvature radius of the object side of the first lens is R1, and the curvature radius of the image side of the first lens is R2, which satisfies the following conditions: 0.001 ≦ | R1 / R2 | ≦ 20. Thereby, the first lens has an appropriate positive refractive power strength, and avoids an increase in spherical aberration from overspeed. Preferably, the following conditions can be satisfied: 0.01 ≦ | R1 / R2 | <10.

The curvature radius of the object side of the seventh lens is R13, and the curvature radius of the image side of the seventh lens is R14, which satisfies the following conditions: -7 <(R11-R12) / (R11 + R12) <50. This is beneficial to correct the astigmatism generated by the optical imaging system.

The distance between the first lens and the second lens on the optical axis is IN12, which satisfies the following conditions: IN12 / f ≦ 3.0. This helps to improve the chromatic aberration of the lens to improve its performance.

The distance between the sixth lens and the seventh lens on the optical axis is IN67, which satisfies the following conditions: IN67 / f ≦ 0.8. This helps to improve the chromatic aberration of the lens to improve its performance.

The thicknesses of the first lens and the second lens on the optical axis are respectively TP1 and TP2, which satisfy the following conditions: 0.1 ≦ (TP1 + IN12) / TP2 ≦ 10. This helps to control the sensitivity of the optical imaging system manufacturing and improve its performance.

The thicknesses of the sixth lens and the seventh lens on the optical axis are TP6 and TP7, respectively. The distance between the two lenses on the optical axis is IN67, which satisfies the following conditions: 0.1 ≦ (TP7 + IN67) / TP6 ≦ 10. This helps to control the sensitivity of the optical imaging system manufacturing and reduce the overall system height.

The thicknesses of the third lens, the fourth lens, and the fifth lens on the optical axis are TP3, TP4, and TP5, respectively. The distance between the third lens and the fourth lens on the optical axis is IN34, and the fourth lens and the fifth lens are on the optical axis. The separation distance on the optical axis is IN45, and the distance from the object side of the first lens to the image side of the seventh lens is InTL, which satisfies the following conditions: 0.1 ≦ TP4 / (IN34 + TP4 + IN45) <1. This helps the layers to slightly correct the aberrations generated by the incident light and reduces the overall system height.

In the optical imaging system of the present invention, the vertical distance between the critical point C71 of the seventh lens object side and the optical axis is HVT71, the vertical distance of the critical point C72 of the seventh lens image side and the optical axis is HVT72, and the seventh lens object side is at The horizontal displacement distance from the intersection point on the optical axis to the critical point C71 on the optical axis is SGC71. The horizontal displacement distance from the intersection point on the optical axis of the seventh lens image side to the critical point C72 on the optical axis is SGC72, which can meet the following conditions. : 0mm ≦ HVT71 ≦ 3mm; 0mm <HVT72 ≦ 6mm; 0 ≦ HVT71 / HVT72; 0mm ≦ ｜ SGC71 ｜ ≦ 0.5mm; 0mm <｜ SGC72 ｜ ≦ 2mm; and 0 <｜ SGC72 ｜ / (｜ SGC72 ｜ + TP7) ≦ 0.9. This can effectively correct aberrations in the off-axis field of view.

The optical imaging system of the present invention satisfies the following conditions: 0.2 ≦ HVT72 / HOI ≦ 0.9. Preferably, the following conditions can be satisfied: 0.3 ≦ HVT72 / HOI ≦ 0.8. This is helpful for aberration correction of the peripheral field of view of the optical imaging system.

The optical imaging system of the present invention satisfies the following conditions: 0 ≦ HVT72 / HOS ≦ 0.5. Preferably, the following conditions can be satisfied: 0.2 ≦ HVT72 / HOS ≦ 0.45. This is helpful for aberration correction of the peripheral field of view of the optical imaging system.

In the optical imaging system of the present invention, the horizontal displacement distance parallel to the optical axis between the intersection point of the seventh lens object side on the optical axis and the closest optical axis inflection point of the seventh lens object side is represented by SGI711. The seventh lens image The horizontal displacement distance parallel to the optical axis between the intersection of the side on the optical axis and the closest optical axis of the seventh lens image side is expressed as SGI721, which satisfies the following conditions: 0 <SGI711 / (SGI711 + TP7) ≦ 0.9 ; 0 <SGI721 / (SGI721 + TP7) ≦ 0.9. Preferably, the following conditions can be satisfied: 0.1 ≦ SGI711 / (SGI711 + TP7) ≦ 0.6; 0.1 ≦ SGI721 / (SGI721 + TP7) ≦ 0.6.

The horizontal displacement distance parallel to the optical axis between the intersection of the seventh lens object side on the optical axis and the second curved point near the optical axis of the seventh lens object side is represented by SGI712. The horizontal displacement distance parallel to the optical axis between the intersection point and the inflection point of the seventh lens image on the second side close to the optical axis is represented by SGI722, which meets the following conditions: 0 <SGI712 / (SGI712 + TP7) ≦ 0.9; 0 <SGI722 /(SGI722+TP7)≦0.9. Preferably, the following conditions can be satisfied: 0.1 ≦ SGI712 /(SGI712+TP7)≦0.6; 0.1 ≦ SGI722 / (SGI722 + TP7) ≦ 0.6.

The vertical distance between the inflection point of the closest optical axis of the seventh lens object side and the optical axis is represented by HIF711. The intersection of the seventh lens image side on the optical axis to the closest optical axis of the seventh lens image side and the inflection point of the optical axis The vertical distance between them is represented by HIF721, which satisfies the following conditions: 0.001mm ≦ | HIF711 | ≦ 5mm; 0.001mm ≦ | HIF721 | ≦ 5mm. Preferably, the following conditions can be satisfied: 0.1mm ≦ | HIF711 | ≦ 3.5mm; 1.5mm ≦ | HIF721 | ≦ 3.5mm.

The vertical distance between the second curved point near the optical axis of the seventh lens object side and the optical axis is represented by HIF712. The intersection of the seventh lens image side on the optical axis to the seventh lens image side second curve near the optical axis The vertical distance between the point and the optical axis is represented by HIF722, which satisfies the following conditions: 0.001mm ≦ | HIF712 | ≦ 5mm; 0.001mm ≦ | HIF722 | ≦ 5mm. Preferably, the following conditions can be satisfied: 0.1mm ≦ | HIF722 | ≦ 3.5mm; 0.1mm ≦ | HIF712 | ≦ 3.5mm.

The vertical distance between the inflection point of the seventh lens object side close to the optical axis and the optical axis is represented by HIF713. The intersection of the seventh lens image side on the optical axis and the seventh lens image side is the third curve close to the optical axis. The vertical distance between the point and the optical axis is represented by HIF723, which satisfies the following conditions: 0.001mm ≦ | HIF713 | ≦ 5mm; 0.001mm ≦ | HIF723 | ≦ 5mm. Preferably, the following conditions can be satisfied: 0.1mm ≦ | HIF723 | ≦ 3.5mm; 0.1mm ≦ | HIF713 | ≦ 3.5mm.

The vertical distance between the inflection point of the seventh lens object side close to the optical axis and the optical axis is represented by HIF714. The intersection of the seventh lens image side on the optical axis to the seventh lens image side is the fourth curve close to the optical axis. The vertical distance between the point and the optical axis is represented by HIF724, which satisfies the following conditions: 0.001mm ≦ | HIF714 | ≦ 5mm; 0.001mm ≦ | HIF724 | ≦ 5mm. Preferably, the following conditions can be satisfied: 0.1mm ≦ | HIF724 | ≦ 3.5mm; 0.1mm ≦ | HIF714 | ≦ 3.5mm.

According to an embodiment of the optical imaging system of the present invention, the lenses with high dispersion coefficient and low dispersion coefficient can be staggered to help correct the chromatic aberration of the optical imaging system.

The equation of the above aspheric surface is: z = ch ² / [1+ | 1- (k + 1) c ² h ² ] ^0.5 ] + A4h ⁴ + A6h ⁶ + A8h ⁸ + A10h ¹⁰ + A12h ¹² + A14h ¹⁴ + A16h ¹⁶ + A18h ¹⁸ + A20h ²⁰ +… (1)

Among them, z is the position value with the surface vertex as the reference at the position of height h along the optical axis direction, k is the cone surface coefficient, c is the inverse of the radius of curvature, and A4, A6, A8, A10, A12, A14, A16 , A18 and A20 are high-order aspheric coefficients.

In the optical imaging system provided by the present invention, the material of the lens may be plastic or glass. When the lens is made of plastic, it can effectively reduce production costs and weight. In addition, when the material of the lens is glass, the thermal effect can be controlled and the design space of the refractive power configuration of the optical imaging system can be increased. In addition, the object side and the image side of the first to seventh lenses in the optical imaging system can be aspheric, which can obtain more control variables. In addition to reducing aberrations, compared with the use of traditional glass lenses, The number of lenses used can be reduced, so the overall height of the optical imaging system of the present invention can be effectively reduced.

Furthermore, in the optical imaging system provided by the present invention, if the lens surface is convex, in principle, the lens surface is convex at the near optical axis; if the lens surface is concave, in principle, the lens surface is at the near optical axis. Concave.

The optical imaging system of the present invention can be applied to an optical system for mobile focusing as required, and has both the characteristics of excellent aberration correction and good imaging quality, thereby expanding the application level.

The optical imaging system of the present invention may further include a driving module as required. The driving module may be coupled to the lenses and cause the lenses to be displaced. The aforementioned driving module may be a voice coil motor (VCM) for driving the lens to focus, or an optical anti-shake element (OIS) for reducing the frequency of out-of-focus caused by lens vibration during shooting.

According to the optical imaging system of the present invention, at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens may be a light filtering element with a wavelength less than 500 nm according to the needs. It can be achieved by coating on at least one surface of the specific lens with a filtering function or the lens itself is made of a material with a filterable short wavelength.

The first imaging surface of the optical imaging system of the present invention may be selected as a plane or a curved surface as required. When the first imaging surface is a curved surface (such as a spherical surface with a radius of curvature), it is helpful to reduce the incident angle required to focus the light on the first imaging surface. In addition to helping to achieve the length of the miniature optical imaging system (TTL) , And also help to improve the contrast.

According to the foregoing implementation manners, specific examples are provided below and described in detail with reference to the drawings.

First embodiment

Please refer to FIG. 1A and FIG. 1B, wherein FIG. 1A shows a schematic diagram of an optical imaging system according to the first embodiment of the present invention, and FIG. 1B shows the optical imaging system of the first embodiment in order from left to right. Spherical aberration, astigmatism and optical distortion curves. FIG. 1C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. FIG. 1D is a diagram illustrating the defocus modulation conversion contrast transfer rate (Through Focus MTF) of the central field of view, 0.3 field of view, and 0.7 field of view of the visible light spectrum according to the embodiment of the present invention; FIG. 1E is a graph showing the defocus modulation conversion contrast transfer rate of the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light spectrum according to the first embodiment of the present invention. As can be seen from FIG. 1A, the optical imaging system includes a first lens 110, an aperture 100, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, and a sixth lens 160 in this order from the object side to the image side. And a seventh lens 170, an infrared filter 180, a first imaging surface 190, and an image sensing element 192.

The first lens 110 has a negative refractive power and is made of plastic. Its object side 112 is concave, its image side 114 is concave and both are aspheric, and its object side 112 has an inflection point and the image side 114 has two Inflection point. The thickness of the first lens on the optical axis is TP1, and the thickness of the first lens at a height of 1/2 the entrance pupil diameter (HEP) is expressed as ETP1.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the first lens on the optical axis and the closest optical axis inflection point of the object side of the first lens is represented by SGI111. The intersection of the image side of the first lens on the optical axis to The horizontal displacement distance between the inflection points of the closest optical axis of the first lens image side parallel to the optical axis is represented by SGI121, which satisfies the following conditions: SGI111 = -0.1110mm; SGI121 = 2.7120mm; TP1 = 2.2761mm; | SGI111 ｜ /(｜SGI111|+TP1)=0.0465; | SGI121 ｜ / (｜ SGI121 | + TP1) = 0.5437.

The horizontal displacement distance parallel to the optical axis between the intersection point of the first lens image side on the optical axis and the second curved point close to the optical axis of the first lens image side is represented by SGI122, which satisfies the following conditions: SGI122 = 4.2315mm; | SGI122 | / (| SGI122 | + TP1) = 0.6502.

The vertical distance between the inflection point of the closest optical axis of the object side of the first lens and the optical axis is represented by HIF111. The intersection point of the first lens image side on the optical axis to the inflection point of the closest optical axis of the first lens image side and the optical axis The vertical distance between them is represented by HIF121, which meets the following conditions: HIF111 = 12.8432mm; HIF111 / HOI = 1.7127; HIF121 = 7.1744mm; HIF121 / HOI = 0.9567.

The vertical distance between the intersection of the first lens image side on the optical axis and the second lens image side closest to the inflection point closest to the optical axis and the optical axis is represented by HIF122, which meets the following conditions: HIF122 = 9.8592mm; HIF122 /HOI=1.3147.

The second lens 120 has a positive refractive power and is made of plastic. The object side surface 122 is a convex surface, and the image side surface 124 is a concave surface. The thickness of the second lens on the optical axis is TP2, and the thickness of the second lens at a height of 1/2 the entrance pupil diameter (HEP) is expressed as ETP2.

The horizontal displacement distance parallel to the optical axis between the intersection of the object lens's side surface on the optical axis and the closest optical axis's inflection point on the object side of the second lens is represented by SGI211. The horizontal displacement distance parallel to the optical axis between the intersection point on the axis and the inflection point of the closest optical axis on the image side of the second lens is represented by SGI221.

The vertical distance between the inflection point of the closest optical axis of the second lens object side and the optical axis is represented by HIF211. The intersection of the second lens image side on the optical axis to the closest optical axis of the second lens image side and the inflection point of the optical axis The vertical distance between them is indicated by HIF221.

The third lens 130 has a negative refractive power and is made of plastic material. Its object side surface 132 is convex, its image side surface 134 is concave, and all of them are aspheric. The thickness of the third lens on the optical axis is TP3, and the thickness of the third lens at the height of 1/2 of the entrance pupil diameter (HEP) is expressed as ETP3.

The horizontal displacement distance parallel to the optical axis between the intersection point of the third lens object side on the optical axis and the closest optical axis inflection point of the third lens object side is represented by SGI311. The intersection point of the third lens image side on the optical axis is The horizontal displacement distance between the inflection points of the closest optical axis of the third lens image side parallel to the optical axis is represented by SGI321.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the third lens on the optical axis and the second inflection point of the object side of the third lens close to the optical axis is represented by SGI312. The image side of the third lens on the optical axis The horizontal displacement distance from the intersection point to the inflection point of the third lens image side close to the optical axis parallel to the optical axis is represented by SGI322.

The vertical distance between the inflection point of the closest optical axis of the third lens object side and the optical axis is represented by HIF311. The intersection of the third lens image side on the optical axis to the closest optical axis of the third lens image side and the inflection point of the optical axis The vertical distance between them is indicated by HIF321.

The vertical distance between the second inflection point of the third lens object side close to the optical axis and the optical axis is represented by HIF312. The intersection of the third lens image side on the optical axis to the second lens image side second inflection near the optical axis The vertical distance between the point and the optical axis is represented by HIF322.

The fourth lens 140 has a positive refractive power and is made of a plastic material. Its object side surface 142 is convex, its image side surface 144 is convex, and both are aspheric. The object side surface 142 has an inflection point. The thickness of the fourth lens on the optical axis is TP4, and the thickness of the fourth lens at a height of 1/2 of the entrance pupil diameter (HEP) is expressed as ETP4.

The horizontal displacement distance parallel to the optical axis between the intersection point of the fourth lens object side on the optical axis and the closest optical axis inflection point of the fourth lens object side is represented by SGI411. The intersection point of the fourth lens image side on the optical axis is The horizontal displacement distance between the inflection points of the closest optical axis of the fourth lens image side parallel to the optical axis is represented by SGI421, which satisfies the following conditions: SGI411 = 0.0018mm; ｜ SGI411 ｜ / (｜ SGI411 | + TP4) = 0.0009.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the fourth lens on the optical axis and the second inflection point of the object side of the fourth lens close to the optical axis is represented by SGI412. The image side of the fourth lens on the optical axis The horizontal displacement distance parallel to the optical axis between the intersection point and the inflection point of the fourth lens image side close to the optical axis is represented by SGI422.

The vertical distance between the inflection point of the closest optical axis of the fourth lens object side and the optical axis is represented by HIF411. The intersection point of the fourth lens image side on the optical axis to the closest optical axis of the fourth lens image side and the inflection point of the optical axis The vertical distance between them is represented by HIF421, which meets the following conditions: HIF411 = 0.7191mm; HIF411 / HOI = 0.0959.

The vertical distance between the second inflection point of the fourth lens object side close to the optical axis and the optical axis is represented by HIF412. The intersection of the fourth lens image side on the optical axis to the second lens image side second inflection near the optical axis The vertical distance between the point and the optical axis is represented by HIF422.

The fifth lens 150 has a positive refractive power and is made of plastic. The object side surface 152 is concave, the image side 154 is convex, and both are aspheric. The object side 152 and the image side 154 each have an inflection point. The thickness of the fifth lens on the optical axis is TP5, and the thickness of the fifth lens at a height of 1/2 the entrance pupil diameter (HEP) is expressed as ETP5.

The horizontal displacement distance parallel to the optical axis between the intersection of the fifth lens's object side on the optical axis and the closest optical axis's inflection point on the fifth lens's object side is represented by SGI511. The intersection of the fifth lens's image side on the optical axis to The horizontal displacement distance between the inflection points of the closest optical axis of the fifth lens image side parallel to the optical axis is represented by SGI521, which satisfies the following conditions: SGI511 = -0.1246mm; SGI521 = -2.1477mm; | SGI511 | + TP5) = 0.0284; | SGI521 ｜ / (｜ SGI521 | + TP5) = 0.3346.

The horizontal displacement distance parallel to the optical axis between the intersection point of the fifth lens object side on the optical axis and the second inflection point of the fifth lens object side close to the optical axis is represented by SGI512. The horizontal displacement distance parallel to the optical axis between the intersection point and the inflection point of the fifth lens image side close to the optical axis is represented by SGI522.

The vertical distance between the inflection point of the closest optical axis on the object side of the fifth lens and the optical axis is represented by HIF511, and the vertical distance between the inflection point of the closest optical axis on the side of the fifth lens image and the optical axis is represented by HIF521. : HIF511 = 3.8179mm; HIF521 = 4.5480mm; HIF511 / HOI = 0.5091; HIF521 / HOI = 0.6065.

The vertical distance between the second inflection point of the fifth lens surface close to the optical axis and the optical axis is represented by HIF512, and the vertical distance between the second inflection point of the fifth lens image side close to the optical axis and the optical axis is HIF522.

The sixth lens 160 has a negative refractive power and is made of plastic material. Its object side surface 162 is convex, its image side 164 is concave, and both its object side 162 and image side 164 have an inflection point. This can effectively adjust the angle of incidence of each field of view on the sixth lens to improve aberrations. The thickness of the sixth lens on the optical axis is TP6, and the thickness of the sixth lens at the height of 1/2 of the entrance pupil diameter (HEP) is expressed as ETP6.

The horizontal displacement distance parallel to the optical axis between the intersection point of the sixth lens object side on the optical axis and the closest optical axis inflection point of the sixth lens object side is represented by SGI611. The intersection point of the sixth lens image side on the optical axis is The horizontal displacement distance between the inflection points of the closest optical axis of the sixth lens image side parallel to the optical axis is represented by SGI621, which satisfies the following conditions: SGI611 = 0.3208mm; SGI621 = 0.5937mm; | SGI611 ｜ / (｜ SGI611 ｜ + TP6) = 0.5167; | SGI621 ｜ / (｜ SGI621 | + TP6) = 0.6643.

The vertical distance between the inflection point of the closest optical axis on the object side of the sixth lens and the optical axis is represented by HIE611, and the vertical distance between the inflection point of the closest optical axis on the side of the sixth lens image and the optical axis is represented by HIF621, which satisfies the following conditions : HIF611 = 1.9655mm; HIF621 = 2.0041mm; HIF611 / HOI = 0.2621; HIF621 / HOI = 0.2672.

The seventh lens 170 has a positive refractive power and is made of plastic. The object side surface 172 is a convex surface and the image side surface 174 is a concave surface. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, each of the object side surface 172 and the image side surface 174 has an inflection point. The thickness of the seventh lens on the optical axis is TP7, and the thickness of the seventh lens at a height of 1/2 of the entrance pupil diameter (HEP) is represented by ETP7.

The horizontal displacement distance parallel to the optical axis between the intersection point of the seventh lens object side on the optical axis and the closest optical axis inflection point of the seventh lens object side is represented by SGI711. The intersection point of the seventh lens image side on the optical axis is The horizontal displacement distance between the inflection points of the closest optical axis of the seventh lens image parallel to the optical axis is represented by SGI721, which satisfies the following conditions: SGI711 = 0.5212mm; SGI721 = 0.5668mm; ｜ SGI711 ｜ / (｜ SGI711 ｜ + TP7) = 0.3179; | SGI721 | / (｜ SGI721 | + TP7) = 0.3364.

The vertical distance between the inflection point of the closest optical axis on the object side of the seventh lens and the optical axis is represented by HIF711, and the vertical distance between the inflection point of the closest optical axis on the image side of the seventh lens and the optical axis is represented by HIF721, which satisfies the following conditions : HIF711 = 1.6707mm; HIF721 = 1.8616mm; HIF711 / HOI = 0.2228; HIF721 / HOI = 0.2482.

In this embodiment, the distance from the coordinate point on the object side of the first lens at a height of 1/2 HEP to the first imaging plane parallel to the optical axis is ETL, and the coordinate point on the object side of the first lens at a height of 1/2 HEP to The horizontal distance between the coordinate points on the image side of the seventh lens at a height of 1/2 HEP parallel to the optical axis is EIN, which meets the following conditions: ETL = 26.980mm; EIN = 24.999mm; EIN / ETL = 0.927.

This embodiment satisfies the following conditions, ETP1 = 2.470mm; ETP2 = 5.144mm; ETP3 = 0.898mm; ETP4 = 1.706mm; ETP5 = 3.901mm; ETP6 = 0.528mm; ETP7 = 1.077mm. The sum of the aforementioned ETP1 to ETP7 SETP = 15.723mm. TP1 = 2.276mm; TP2 = 5.240mm; TP3 = 0.837mm; TP4 = 2.002mm; TP5 = 4.271mm; TP6 = 0.300mm; TP7 = 1.118mm; the sum of the aforementioned TP1 to TP7 STP = 16.044mm. SETP / STP = 0.980. SETP / EIN = 0.629.

This embodiment specifically controls the proportional relationship (ETP / TP) between the thickness (ETP) of each of the lenses at a height of 1/2 the entrance pupil diameter (HEP) and the thickness (TP) of the lens on the optical axis to which the surface belongs. To achieve a balance between manufacturability and ability to correct aberrations, it meets the following conditions: ETP1 / TP1 = 1.085; ETP2 / TP2 = 0.982; ETP3 / TP3 = 1.073; ETP4 / TP4 = 0.852; ETP5 / TP5 = 0.914; ETP6 /TP6=1.759; ETP7 / TP7 = 0.963.

In this embodiment, the horizontal distance between two adjacent lenses at a height of 1/2 incident pupil diameter (HEP) is controlled so as to achieve a balance between the “shrinking” degree of the length of the optical imaging system HOS, manufacturability, and the ability to correct aberrations. , Especially controlling the proportional relationship between the horizontal distance (ED) of the two adjacent lenses at the height of 1/2 incident pupil diameter (HEP) and the horizontal distance (IN) of the two adjacent lenses on the optical axis (ED / IN ), Which meets the following conditions, the horizontal distance between the first lens and the second lens at a height of 1/2 of the entrance pupil diameter (HEP) parallel to the optical axis is ED12 = 4.474mm; the distance between the second lens and the third lens is 1 The horizontal distance parallel to the optical axis of the / 2 incidence pupil diameter (HEP) height is ED23 = 0.349mm; the horizontal distance parallel to the optical axis between the third lens and the fourth lens at 1/2 of the entrance pupil diameter (HEP) height ED34 = 1.660mm; the horizontal distance between the fourth lens and the fifth lens at a height of 1/2 incident pupil diameter (HEP) parallel to the optical axis is ED45 = 1.794mm; the fifth lens and the sixth lens are at 1 / 2 The horizontal distance of the entrance pupil diameter (HEP) height parallel to the optical axis is ED56 = 0.714mm. The horizontal distance between the sixth lens and the seventh lens parallel to the optical axis at a height of 1/2 incident pupil diameter (HEP) is ED67 = 0.284mm. The sum of the aforementioned ED12 to ED67 is represented by SED and SED = 9.276mm.

The horizontal distance between the first lens and the second lens on the optical axis is IN12 = 4.552mm, and ED12 / IN12 = 0.983. The horizontal distance between the second lens and the third lens on the optical axis is IN23 = 0.162 mm, ED23 / IN23 = 2.153. The horizontal distance between the third lens and the fourth lens on the optical axis is IN34 = 1.927mm, and ED34 / IN34 = 0.862. The horizontal distance between the fourth lens and the fifth lens on the optical axis is IN45 = 1.515mm, and ED45 / IN45 = 1.184. The horizontal distance between the fifth lens and the sixth lens on the optical axis is IN56 = 0.050mm, and ED56 / IN56 = 14.285. The horizontal distance between the sixth lens and the seventh lens on the optical axis is IN67 = 0.211mm, and ED67 / IN67 = 1.345. The sum of the aforementioned IN12 to IN67 is represented by SIN and SIN = 8.418mm. SED / SIN = 1.102.

This implementation also meets the following conditions: ED12 / ED23 = 12.816; ED23 / ED34 = 0.210; ED34 / ED45 = 0.925; ED45 / ED56 = 2.512; ED56 / ED67 = 2.512; IN12 / IN23 = 28.080; IN23 / IN34 = 0.084; IN34 /IN45=1.272; IN45 / IN56 = 30.305; IN56 / IN67 = 0.236.

The horizontal distance from the coordinate point on the image side of the seventh lens at a height of 1/2 HEP to the first imaging plane parallel to the optical axis is EBL = 1.982mm, and the point of intersection of the image side of the seventh lens and the optical axis to the first The horizontal distance between the imaging planes parallel to the optical axis is BL = 2.517mm. The embodiment of the present invention can satisfy the following formula: EBL / BL = 0.7874. In this embodiment, the distance from the coordinate point on the image side of the seventh lens at a height of 1/2 HEP to the infrared filter parallel to the optical axis is EIR = 0.865mm. The intersection point of the image side of the seventh lens with the optical axis is to the infrared. The distance between the filters parallel to the optical axis is PIR = 1.400mm and satisfies the following formula: EIR / PIR = 0.618.

The features described below in this embodiment and the inflection point are obtained based on the main reference wavelength of 555 nm.

The infrared filter 180 is made of glass and is disposed between the seventh lens 170 and the first imaging surface 190 without affecting the focal length of the optical imaging system.

In the optical imaging system of this embodiment, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, and the half of the maximum viewing angle in the optical imaging system is HAF, and the value is as follows: f = 4.3019mm; f / HEP = 1.2; and HAF = 59.9968 degrees and tan (HAF) = 1.7318.

In the optical imaging system of this embodiment, the focal length of the first lens 110 is f1, and the focal length of the seventh lens 170 is f7, which satisfies the following conditions: f1 = -14.5286mm; | f / f1 | = 0.2961; f7 = 8.2933mm ; | F1 |> f7; and | f1 / f7 | = 1.7519.

In the optical imaging system of this embodiment, the focal lengths of the second lens 120 to the sixth lens 160 are f2, f3, f4, f5, and f6, respectively, which satisfy the following conditions: | f2 | + | f3 | + | f4 | + | f5 ｜ + ｜ f6 ｜ = 144.7494mm; ｜ f1 ｜ + ｜ f7 ｜ = 22.8219mm And | f2 | + | f3 | + | f4 | + | f5 | + | f6 |> | f1 | + | f7 |.

The ratio of the focal length f of the optical imaging system to the focal length fp of each lens with a positive refractive power, PPR, and the ratio of the focal length f of the optical imaging system to the focal length fn of each lens with a negative refractive power, NPR. The optical imaging of this embodiment In the system, the sum of PPR of all positive refractive lenses is Σ PPR = f / f2 + f / f4 + f / f5 + f / f7 = 1.7384, and the sum of NPR of all negative refractive lenses is Σ NPR = f / f1 + f / f3 + f / f6 = -0.9999, Σ PPR / | Σ NPR | = 1.7386. The following conditions are also met: f / f2 ｜ = 0.1774; f / f3 ｜ = 0.0443; f / f4 ｜ = 0.4411; f / f5 ｜ = 0.6012; f / f6 ｜ = 0.6595; f / f7 | = 0.5187.

In the optical imaging system of this embodiment, the distance between the first lens object side 112 to the seventh lens image side 174 is InTL, the distance between the first lens object side 112 to the first imaging surface 190 is HOS, and the aperture 100 to the first The distance between an imaging surface 190 is InS, half of the diagonal length of the effective sensing area of the image sensing element 192 is HOI, and the distance from the image side 174 of the seventh lens to the first imaging surface 190 is BFL, which meets the following conditions : InTL + BFL = HOS; HOS = 26.9789mm; HOI = 7.5mm; HOS / HOI = 3.5977; HOS / f = 6.2715; InS = 12.4615mm; and InS / HOS = 0.4619.

In the optical imaging system of this embodiment, the sum of the thicknesses of all the lenses with refractive power on the optical axis is Σ TP, which satisfies the following conditions: Σ TP = 16.0446mm; and Σ TP / InTL = 0.6559. Thereby, the contrast of the system imaging and the yield of lens manufacturing can be taken into account at the same time, and an appropriate back focus can be provided to accommodate other components.

In the optical imaging system of this embodiment, the curvature radius of the object side surface 112 of the first lens is R1, and the curvature radius of the image side 114 of the first lens is R2, which satisfies the following conditions: | R1 / R2 | = 129.9952. Thereby, the first lens has an appropriate positive refractive power strength, and avoids an increase in spherical aberration from overspeed.

In the optical imaging system of this embodiment, the curvature radius of the object side surface 172 of the seventh lens is R13, and the curvature radius of the image side 174 of the seventh lens is R14, which satisfies the following conditions: (R13-R14) / (R13 + R14) = -0.0806. This is beneficial to correct the astigmatism generated by the optical imaging system.

In the optical imaging system of this embodiment, the sum of the focal lengths of all lenses with positive refractive power is Σ PP, which satisfies the following conditions: Σ PP = f2 + f4 + f5 + f7 = 49.4535mm; and f4 / (f2 + f4 + f5 + f7) = 0.1972. Therefore, it is helpful to appropriately allocate the positive refractive power of the fourth lens 140 to other positive lenses, so as to suppress the occurrence of significant aberrations during the traveling process of incident light.

In the optical imaging system of this embodiment, the total focal length of all lenses with negative refractive power The sum is Σ NP, which satisfies the following conditions: Σ NP = f1 + f3 + f6 = -118.1178mm; and f1 / (f1 + f3 + f6) = 0.1677. Therefore, it is helpful to appropriately allocate the negative refractive power of the first lens to other negative lenses, so as to suppress the occurrence of significant aberrations during the traveling process of incident light.

In the optical imaging system of this embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis is IN12, which satisfies the following conditions: IN12 = 4.5524mm; IN12 / f = 1.0582. This helps to improve the chromatic aberration of the lens to improve its performance.

In the optical imaging system of this 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: TP1 = 2.2761mm; TP2 = 0.2398mm; and (TP1 + IN12 ) /TP2=1.3032. This helps to control the sensitivity of the optical imaging system manufacturing and improve its performance.

In the optical imaging system of this embodiment, the thicknesses of the sixth lens 160 and the seventh lens 170 on the optical axis are TP6 and TP7, respectively. The distance between the two lenses on the optical axis is IN67, which meets the following conditions: TP6 = 0.3000mm; TP7 = 1.1182mm; and (TP7 + IN67) /TP6=4.4322. This helps to control the sensitivity of the optical imaging system manufacturing and reduce the overall system height.

In the optical imaging system of this embodiment, the thicknesses of the third lens 130, the fourth lens 140, and the fifth lens 150 on the optical axis are TP3, TP4, and TP5, respectively. The third lens 130 and the fourth lens 140 are on the optical axis. The separation distance of the lens is IN34, the separation distance of the fourth lens 140 and the fifth lens 150 on the optical axis is IN45, and the distance between the object side 112 of the first lens and the image side 174 of the seventh lens is InTL, which meets the following conditions: TP3 = 0.8369mm; TP4 = 2.0022mm; TP5 = 4.2706mm; IN34 = 1.9268mm; IN45 = 1.5153mm; and TP4 / (IN34 + TP4 + IN45) = 0.3678. This helps to correct the aberrations produced by the incident light and to reduce the total height of the system.

In the optical imaging system of this embodiment, the horizontal displacement distance from the intersection of the sixth lens object side 162 on the optical axis to the maximum effective radius position of the sixth lens object side 162 on the optical axis is InRS61, and the sixth lens image side 164 is on The horizontal displacement distance from the intersection point on the optical axis to the maximum effective radius position of the sixth lens image side 164 on the optical axis is InRS62, and the thickness of the sixth lens 160 on the optical axis is TP6, which meets the following conditions: InRS61 = -0.7823mm ; InRS62 = -0.2166mm; and | InRS62 | /TP6=0.722. This helps to make and shape the lens, and effectively maintains its miniaturization.

In the optical imaging system of this embodiment, the vertical distance between the critical point of the sixth lens surface 162 and the optical axis is HVT61, and the vertical distance between the critical point of the sixth lens image side 164 and the optical axis is HVT62, which satisfies the following conditions: HVT61 = 3.3498mm; HVT62 = 3.9860mm; and HVT61 / HVT62 = 0.8404.

In the optical imaging system of this embodiment, the horizontal displacement distance from the intersection of the seventh lens object side 172 on the optical axis to the maximum effective radius position of the seventh lens object side 172 on the optical axis is InRS71, and the seventh lens image side 174 is on The horizontal displacement distance from the intersection point on the optical axis to the maximum effective radius position of the seventh lens image side 174 on the optical axis is InRS72, and the thickness of the seventh lens 170 on the optical axis is TP7, which meets the following conditions: InRS71 = -0.2756mm ; InRS72 = -0.0938mm; and | InRS72 | /TP7=0.0839. This helps to make and shape the lens, and effectively maintains its miniaturization.

In the optical imaging system of this embodiment, the vertical distance between the critical point of the seventh lens object side 172 and the optical axis is HVT71, and the vertical distance between the critical point of the seventh lens image side 174 and the optical axis is HVT72, which satisfies the following conditions: HVT71 = 3.6822mm; HVT72 = 4.0606mm; and HVT71 / HVT72 = 0.9068. This can effectively correct aberrations in the off-axis field of view.

In the optical imaging system of this embodiment, it satisfies the following conditions: HVT72 / HOI = 0.5414. This is helpful for aberration correction of the peripheral field of view of the optical imaging system.

In the optical imaging system of this embodiment, it satisfies the following conditions: HVT72 / HOS = 0.1505. This is helpful for aberration correction of the peripheral field of view of the optical imaging system.

In the optical imaging system of this embodiment, the second lens, the third lens, and the seventh lens have negative refractive power, the dispersion coefficient of the second lens is NA2, the dispersion coefficient of the third lens is NA3, and the dispersion coefficient of the seventh lens is NA7, which satisfies the following conditions: 1 ≦ NA7 / NA2. This helps to correct the chromatic aberration of the optical imaging system.

In the optical imaging system of this embodiment, the TV distortion of the optical imaging system during the image formation is TDT, and the optical distortion during the image formation is ODT, which satisfies the following conditions: | TDT | = 2.5678%; | ODT | = 2.1302%.

The light in any field of view of the embodiment of the present invention can be further divided into sagittal ray and tangential ray, and the evaluation basis of the focus offset and MTF value is a spatial frequency of 110 cycles / mm. The focus offsets of the maximum defocus MTF of the sagittal rays of the central field of view, 0.3 fields of view, and 0.7 fields of view are represented by VSFS0, VSFS3, and VSFS7 (measurement units: mm), and the values are 0.000mm,- 0.005mm, 0.000mm; the maximum defocus MTF of the sagittal rays of the visible central field of view, 0.3 field of view, and 0.7 field of view is VSMTF0, VSMTF3 and VSMTF7 indicate that the values are 0.886, 0.885, and 0.863 respectively; the focal shifts of the maximum out-of-focus MTF of the meridional rays in the central field of view, 0.3 field of view, and 0.7 field of view are represented by VTFS0, VTFS3, and VTFS7 (Unit of measurement: mm), the values of which are 0.000mm, 0.001mm, and -0.005mm respectively; the maximum defocus MTF of the meridional rays of the central field of view, 0.3 field of view, and 0.7 field of view is VTMTF0, VTMTF3, VTMTF7 Indicates that the values are 0.886, 0.868, 0.796. The average focus shift amount (position) of the focus shift amounts of the aforementioned sagittal three-view field of the visible arc and the meridional three-view field of visible light is represented by AVFS (measurement unit: mm), which satisfies the absolute value | (VSFS0 + VSFS3 + VSFS7 + VTFS0 + VTFS3 + VTFS7) / 6 ｜ = ｜ 0.000mm ｜.

In this embodiment, the focus offsets of the maximum defocus MTF of the sagittal rays of the central field of view, the field of view of 0.3, and the field of view of 0.7 are represented by ISFS0, ISFS3, and ISFS7 (unit of measurement: mm), and the values are respectively It is 0.025mm, 0.020mm, 0.020mm. The average focus offset (position) of the aforementioned three focus fields of the sagittal plane is represented by AISFS; the center of the infrared light field, the 0.3 field of view, and the sagittal plane of the 0.7 field of view The maximum defocus MTF of the light is represented by ISMTF0, ISMTF3, and ISMTF7, and the values are 0.787, 0.802, and 0.772 respectively; the maximum defocus MTF of the meridional rays of the central field, 0.3 field, and 0.7 field of infrared light The focus offsets are respectively represented by ITFS0, ITFS3, and ITFS7 (units of measurement: mm), and their values are 0.025, 0.035, and 0.035, respectively. The average focus offset (position) of the focus offsets of the three fields of view of the meridian plane is AITFS (measurement unit: mm); the maximum defocus MTF of the meridional rays of the central field of view, 0.3 field of view, and 0.7 field of view of the infrared light is represented by IMTTF0, IMTTF3, and IMTTF7, and the values are 0.787, 0.805, 0.721, respectively . The average focus offset (position) of the aforementioned infrared light sagittal three-field and infrared light meridional three-field is represented by AIFS (unit of measurement: mm), which satisfies the absolute value | (ISFS0 + ISFS3 + ISFS7 + ITFS0 + ITFS3 + ITFS7) / 6 ｜ = ｜ 0.02667mm ｜.

The focus offset between the visible light center field focus point and the infrared light center field focus point (RGB / IR) of the entire optical imaging system in this embodiment is represented by FS (that is, a wavelength of 850 nm to a wavelength of 555 nm, a unit of measurement: mm) , Which satisfies the absolute value ｜ (VSFS0 + VTFS0) / 2- (ISFS0 + ITFS0) / 2 ｜ = ｜ 0.025mm ｜; the average focus offset of visible light three field of view and the average focus of infrared three field of view of the entire optical imaging system The difference between the offsets (RGB / IR) (focus offset) is expressed in AFS (that is, wavelength 850nm vs. wavelength 555nm, unit of measurement: mm), which satisfies the absolute value | AIFS-AVFS | = | 0.02667mm | .

In the optical imaging system of this embodiment, the light of visible light on the first imaging surface The modulation conversion contrast transfer rate (MTF value) of the axis, 0.3HOI and 0.7HOI at the spatial frequency of 55cycles / mm is represented by MTFE0, MTFE3, and MTFE7, respectively, which meet the following conditions: MTFE0 is about 0.35; MTFE3 is about 0.14; and MTFE7 About 0.28. The optical axis of visible light on the first imaging surface, 0.3HOI, and 0.7HOI at the spatial frequency of 110 cycles / mm. The modulation conversion contrast transfer rates (MTF values) are expressed as MTFQ0, MTFQ3, and MTFQ7, respectively, which meet the following conditions: Are 0.126; MTFQ3 is approximately 0.075; and MTFQ7 is approximately 0.177. The optical axis, 0.3HOI, and 0.7HOI on the first imaging plane of the modulation conversion contrast transfer rate (MTF value) at a spatial frequency of 220 cycles / mm are respectively expressed as MTFH0, MTFH3, and MTFH7, which meet the following conditions: 0.01; MTFH3 is about 0.01; and MTFH7 is about 0.01.

In the optical imaging system of this embodiment, when the infrared working wavelength of 850nm is focused on the second imaging surface, the optical axis of the image on the second imaging surface, 0.3HOI, and 0.7HOI are three spatial frequency (55cycles / mm) modulation. The conversion contrast transfer rate (MTF value) is represented by MTFI0, MTFI3, and MTFI7, which meet the following conditions: MTFI0 is about 0.01; MTFI3 is about 0.01; and MTFI7 is about 0.01.

Refer to Tables 1 and 2 below for further cooperation.

Table 1 shows the detailed structural data of the first embodiment in FIG. 1, where the units of the radius of curvature, thickness, distance, and focal length are mm, and the surface 0-16 sequentially represents the surface from the object side to the image side. Table 2 shows the aspheric data in the first embodiment, where k represents the cone coefficient in the aspheric curve equation, and A1-A20 represents the aspherical coefficients of order 1-20 on each surface. In addition, the tables of the following embodiments are schematic diagrams and aberration curves corresponding to the embodiments. The definitions of the data in the tables are the same as those of the first embodiment. The definitions in Table 1 and Table 2 are the same, and will not be repeated here.

Second embodiment

Please refer to FIG. 2A and FIG. 2B, wherein FIG. 2A shows a schematic diagram of an optical imaging system according to a second embodiment of the present invention, and FIG. 2B shows the optical imaging system of the second embodiment in order from left to right. Spherical aberration, astigmatism and optical distortion curves. FIG. 2C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. Figure 2D is a diagram showing the center-of-view, 0.3-field, and 0.7-field defocus modulation conversion contrast transfer rates of the visible light spectrum of this embodiment; Figure 2E is a diagram of the infrared light spectrum of the second embodiment of the present invention Defocus modulation conversion vs. transfer rate graph for the center field of view, 0.3 field of view, and 0.7 field of view. As can be seen from FIG. 2A, the optical imaging system includes the first lens 210, the second lens 220, the aperture 200, the third lens 230, the fourth lens 240, the fifth lens 250, and the sixth lens 260 in this order from the object side to the image side. And a seventh lens 270, an infrared filter 280, a first imaging surface 290, and an image sensing element 292.

The first lens 210 has a negative refractive power and is made of glass. The object side surface 212 is a convex surface, and the image side surface 214 is a concave surface. Both are aspherical surfaces.

The second lens 220 has a positive refractive power and is made of glass. Its object side surface 222 is a concave surface, and its image side surface 224 is a convex surface, and both of them are aspherical surfaces.

The third lens 230 has a positive refractive power and is made of glass. Its object-side surface 232 is convex, its image-side 234 is convex, and both are aspherical. Its object-side 232 has an inflection point.

The fourth lens 240 has a negative refractive power and is made of glass. Its object side surface 242 is a concave surface, and its image side surface 244 is a concave surface, which are all aspheric surfaces.

The fifth lens 250 has a positive refractive power and is made of glass. Its object side surface 252 is convex, its image side 254 is concave, and both are aspheric, and its image side 254 has an inflection point.

The sixth lens 260 has a positive refractive power and is made of glass. The object side surface 262 is a concave surface, the image side surface 264 is a convex surface, and they are all aspheric surfaces. Accordingly, the angle of incidence of each field of view on the sixth lens 260 can be effectively adjusted to improve aberrations.

The seventh lens 270 has a negative refractive power and is made of glass. Its object side surface 272 is convex and its image side surface 274 is concave. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, both the object side surface 272 and the image side surface 274 of the seventh lens have an inflection point, which can effectively suppress the incident angle of the off-axis field of view and further correct the aberration of the off-axis field of view.

The infrared filter 280 is made of glass and is disposed on the seventh lens 270 and the first lens The imaging planes 290 do not affect the focal length of the optical imaging system.

Please refer to Tables 3 and 4 below.

In the second embodiment, the aspherical curve equation is expressed as the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

According to Table 3 and Table 4, the following conditional formula values can be obtained:

According to Table 3 and Table 4, the following conditional formula values can be obtained:

Third embodiment

Please refer to FIG. 3A and FIG. 3B, wherein FIG. 3A shows a schematic diagram of an optical imaging system according to a third embodiment of the present invention, and FIG. 3B shows the optical imaging system of the third embodiment in order from left to right. Spherical aberration, astigmatism and optical distortion curves. FIG. 3C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. Fig. 3D is a diagram showing the central field of view, 0.3 field of view, and 0.7 field of view of the visible spectrum of the present embodiment with defocus modulation conversion and transfer rate; Fig. 3E is a diagram illustrating the infrared spectrum of the second embodiment of the present invention Defocus modulation conversion of the center field of view, 0.3 field of view, 0.7 field of view Mobility chart. As can be seen from FIG. 3A, the optical imaging system includes a first lens 310, a second lens 320, an aperture 300, a third lens 330, a fourth lens 340, a fifth lens 350, and a sixth lens 360 in this order from the object side to the image side. And a seventh lens 370, an infrared filter 380, a first imaging surface 390, and an image sensing element 392.

The first lens 310 has a negative refractive power and is made of glass. The object side surface 312 is a convex surface, and the image side surface 314 is a concave surface, and they are all aspheric surfaces.

The second lens 320 has a positive refractive power and is made of glass. Its object side surface 322 is a concave surface, and its image side surface 324 is a convex surface, and all of them are aspherical.

The third lens 330 has a positive refractive power and is made of glass. Its object side surface 332 is convex, its image side surface 334 is convex, and both are aspheric. Its object side surface 322 has a point of inflection.

The fourth lens 340 has a negative refractive power and is made of glass. Its object side surface 342 is concave, its image side 344 is concave, and both are aspheric. Its image side 344 has an inflection point.

The fifth lens 350 has a positive refractive power and is made of glass. Its object side 352 is concave, its image side 354 is convex, and all of them are aspheric. The object side 352 has a point of inflection.

The sixth lens 360 has a positive refractive power and is made of glass. The object side 362 is concave, the image side 364 is convex, and both are aspheric. The image side 364 has two inflection points. This can effectively adjust the angle of incidence of each field of view on the sixth lens 360 to improve aberrations.

The seventh lens 370 has a negative refractive power and is made of glass. Its object-side surface 372 is convex, its image-side 374 is concave, and both are aspherical. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, the image side 374 has two inflection points, which can effectively suppress the incident angle of the off-axis field of view and further correct the aberration of the off-axis field of view.

The infrared filter 380 is made of glass and is disposed between the seventh lens 370 and the first imaging surface 390 without affecting the focal length of the optical imaging system.

Please refer to Table 5 and Table 6 below.

In the third embodiment, the aspherical curve equation is expressed as the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

According to Table 5 and Table 6, the following conditional formula values can be obtained:

According to Table 5 and Table 6, the following conditional formula values can be obtained:

Fourth embodiment

Please refer to FIG. 4A and FIG. 4B. FIG. 4A shows a schematic diagram of an optical imaging system according to a fourth embodiment of the present invention. FIG. Spherical aberration, astigmatism and optical distortion curves. FIG. 4C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. FIG. 4D is a diagram showing the center-of-view, 0.3-field, and 0.7-field defocus modulation conversion contrast transfer ratio of the visible light spectrum of this embodiment; FIG. 4E is a diagram of the infrared light spectrum of the second embodiment of the present invention Defocus modulation conversion vs. transfer rate graph for the center field of view, 0.3 field of view, and 0.7 field of view. As can be seen from FIG. 4A, the optical imaging system includes a first lens 410, a second lens 420, a third lens 430, an aperture 400, a fourth lens 440, a fifth lens 450, and a sixth lens 460 in order from the object side to the image side. And a seventh lens 470, an infrared filter 480, a first imaging surface 490, and an image sensor Piece 492.

The first lens 410 has a negative refractive power and is made of glass. The object side surface 412 is a convex surface, and the image side surface 414 is a concave surface. Both are aspherical surfaces.

The second lens 420 has a negative refractive power and is made of glass. Its object side 422 is concave, its image side 424 is concave, and both are aspheric.

The third lens 430 has a positive refractive power and is made of glass. Its object side 432 is convex, and its image side 434 is convex, and all of them are aspheric.

The fourth lens 440 has a positive refractive power and is made of glass. The object side 442 is convex, and the image side 444 is convex, and all of them are aspheric.

The fifth lens 450 has a positive refractive power and is made of glass. Its object-side surface 452 is convex, and its image-side 454 is convex, and all of them are aspheric.

The sixth lens 460 has a negative refractive power and is made of glass. Its object side 462 is convex, its image side 464 is concave, and all of them are aspheric. Thereby, the angle of incidence of each field of view on the sixth lens 460 can be effectively adjusted to improve aberrations.

The seventh lens 470 has a positive refractive power and is made of glass. Its object-side surface 472 is convex, and its image-side 474 is convex, and all of them are aspheric. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, it can effectively suppress the incident angle of the off-axis field of view, and further correct the aberration of the off-axis field of view.

The infrared filter 480 is made of glass and is disposed between the seventh lens 470 and the first imaging surface 490 without affecting the focal length of the optical imaging system.

Please refer to Table 7 and Table 8 below.

In the fourth embodiment, the aspherical curve equation represents the shape of the first embodiment formula. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

According to Table 7 and Table 8, the following conditional formula values can be obtained:

According to Table 7 and Table 8, the following conditional formula values can be obtained:

Fifth Embodiment

Please refer to FIG. 5A and FIG. 5B, wherein FIG. 5A shows a schematic diagram of an optical imaging system according to a fifth embodiment of the present invention, and FIG. 5B shows the optical imaging system of the fifth embodiment in order from left to right. Spherical aberration, astigmatism and optical distortion curves. FIG. 5C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. Fig. 5D is a diagram showing the central field of view, 0.3 field of view, and 0.7 field of view of the visible spectrum of the present embodiment with defocus modulation conversion and transfer rate; Fig. 5E is a diagram illustrating the infrared spectrum of the second embodiment of the present invention Defocus modulation conversion vs. transfer rate graph for the center field of view, 0.3 field of view, and 0.7 field of view. It can be seen from FIG. 5A that the optical imaging system includes a first lens 510, a second lens 520, a third lens 530, an aperture 500, a fourth lens 540, a fifth lens 550, and a sixth lens 560 in order from the object side to the image side. And a seventh lens 570, an infrared filter 580, a first imaging surface 590, and an image sensing element 592.

The first lens 510 has a negative refractive power and is made of glass. Its object side 512 is convex, its image side 514 is concave, and both are aspheric.

The second lens 520 has a negative refractive power and is made of glass. The object side 522 is concave, the image side 524 is concave, and both are aspheric. The object side 522 has a point of inflection.

The third lens 530 has a positive refractive power and is made of glass. Its object side 532 is convex, its image side 534 is convex, and both are aspheric. Its object side 532 has a point of inflection.

The fourth lens 540 has a positive refractive power and is made of glass. The convex surface, the image side surface 544 of which is convex and are all aspheric surfaces, and the object side surface 542 of the convex surface has an inflection point.

The fifth lens 550 has a positive refractive power and is made of glass. The object side surface 552 is a convex surface, and the image side surface 554 is a convex surface, and they are all aspheric surfaces.

The sixth lens 560 has a negative refractive power and is made of glass. Its object side 562 is concave, its image side 564 is concave, and both are aspheric. The object side 562 has an inflection point. Thereby, the angle of incidence of each field of view on the sixth lens 560 can be effectively adjusted to improve aberrations.

The seventh lens 570 has a positive refractive power and is made of glass. Its object side 572 is convex, its image side 574 is concave, and its object side 572 and image side 574 each have a point of inflection. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, it can effectively suppress the incident angle of the off-axis field of view and correct the aberrations of the off-axis field of view.

The infrared filter 580 is made of glass and is disposed between the seventh lens 570 and the first imaging surface 590 without affecting the focal length of the optical imaging system.

Please refer to Tables 9 and 10 below.

In the fifth embodiment, the aspherical curve equation is expressed as the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

According to Table 9 and Table 10, the following conditional formula values can be obtained:

According to Table 9 and Table 10, the following conditional formula values can be obtained:

Sixth embodiment

Please refer to FIG. 6A and FIG. 6B. FIG. 6A shows a schematic diagram of an optical imaging system according to a sixth embodiment of the present invention. FIG. Spherical aberration, astigmatism and optical distortion curves. FIG. 6C is a characteristic diagram of the visible light spectrum modulation conversion in this embodiment. FIG. 6D is a diagram showing the center-of-view, 0.3-field, and 0.7-field defocus modulation conversion contrast transfer ratio of the visible light spectrum of this embodiment; FIG. 6E is a diagram of the infrared light spectrum of the second embodiment of the present invention Defocus modulation conversion vs. transfer rate graph for the center field of view, 0.3 field of view, and 0.7 field of view. It can be seen from FIG. 6A that the optical imaging system includes a first lens 610, a second lens 620, a third lens 630, an aperture 600, a fourth lens 640, a fifth lens 650, and a sixth lens 660 in order from the object side to the image side. , A seventh lens 670, an infrared filter 680, a first imaging surface 690, and an image sensing element 692.

The first lens 610 has a negative refractive power and is made of glass. Its object-side surface 612 is convex, its image-side 614 is concave, and both are aspherical.

The second lens 620 has a negative refractive power and is made of glass. The object side 622 is concave, and the image side 624 is concave.

The third lens 630 has a positive refractive power and is made of glass. Its object side 632 is convex, its image side 634 is convex, and both are aspheric. Its object side 632 has a point of inflection.

The fourth lens 640 has a positive refractive power and is made of glass. Its object side 642 is convex, its image side 644 is convex, and all are aspheric. Its object side 642 has a point of inflection.

The fifth lens 650 has a positive refractive power and is made of glass. Its object side 652 is convex, its image side 654 is convex, and both are aspheric. Its object side 652 has a point of inflection.

The sixth lens 660 has a negative refractive power and is made of glass. Its object side 662 is convex, its image side 664 is concave, and its object side 662 has one inflection point and the image side 664 has two inflection points. This can effectively adjust the angle of incidence of each field of view on the sixth lens 660 to improve aberrations.

The seventh lens 670 has a positive refractive power and is made of glass. Its object side 672 is convex, its image side 674 is concave, and both its object side 672 and image side 674 have a point of inflection. Thereby, it is advantageous to shorten the back focal length to maintain miniaturization. In addition, it can also effectively suppress the angle of incidence of the off-axis field of view, and further correct the aberration of the off-axis field of view.

The infrared filter 680 is made of glass and is disposed between the seventh lens 670 and the first imaging surface 690 without affecting the focal length of the optical imaging system.

Please refer to Table 11 and Table 12 below.

In the sixth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

According to Table 11 and Table 12, the following conditional formula values can be obtained:

According to Table 11 and Table 12, the following conditional formula values can be obtained:

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the attached patent application.

Although the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those having ordinary knowledge in the art that the spirit of the present invention as defined by the scope of the following patent applications and their equivalents will be understood Various changes in form and detail can be made under the categories.

Claims (24)

An optical imaging system includes: a first lens having a refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power A fifth lens with a refractive power; a sixth lens with a refractive power; a seventh lens with a refractive power; a first imaging plane; a visible light image plane perpendicular to the optical axis and its center The defocus modulation conversion contrast ratio (MTF) of the field of view at the first spatial frequency has a maximum value; and a second imaging plane; it is a specific infrared light image plane perpendicular to the optical axis and its central field of view is The defocus modulation conversion contrast ratio (MTF) of a spatial frequency has a maximum value. Among the seven lenses of the optical imaging system having a refractive power, at least one of the first lens to the seventh lens has a positive refractive power. The focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, f7, the focal length of the optical imaging system is f, and the entrance pupil diameter of the optical imaging system is HEP. Lens object side to this The first imaging surface has a distance HOS on the optical axis, the object side of the first lens to the seventh lens image side has a distance InTL on the optical axis, half of the maximum viewing angle of the optical imaging system is HAF, and the optical The imaging system has a maximum imaging height HOI perpendicular to the optical axis on the first imaging plane, and the thicknesses of the first lens to the seventh lens at a height of 1/2 HEP and parallel to the optical axis are ETP1, ETP2, ETP3, ETP4, ETP5, ETP6, and ETP7, the sum of the aforementioned ETP1 to ETP7 is SETP, and the thicknesses of the first lens to the seventh lens on the optical axis are TP1, TP2, TP3, TP4, TP5, TP6, and TP7, and the aforementioned TP1 to The total of TP7 is STP, and the distance between the first imaging surface and the second imaging surface on the optical axis is FS, which satisfies the following conditions: 1.0 ≦ f / HEP ≦ 10.0; 0deg <HAF ≦ 150deg; 0.5 ≦ SETP / STP <1 and | FS | ≦ 60 μm. The optical imaging system according to claim 1, wherein the infrared light has a wavelength between 700 nm and 1300 nm and the first spatial frequency is expressed by SP1, which satisfies the following conditions: SP1 ≦ 440 cycles / mm. The optical imaging system according to claim 1, wherein the horizontal distance from the coordinate point on the object side of the first lens at a height of 1/2 HEP to the first imaging plane and parallel to the optical axis is ETL, the first lens object The horizontal distance from the coordinate point at the 1/2 HEP height on the side to the coordinate point at the 1/2 HEP height on the side of the image of the seventh lens parallel to the optical axis is EIN, which satisfies the following conditions: 0.2 ≦ EIN / ETL < 1. The optical imaging system according to claim 1, wherein a material of at least one of the first lens to the seventh lens is glass. The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditions: HOS / HOI ≧ 1.2. The optical imaging system according to claim 1, wherein at least one surface of each of at least one of the first lens to the seventh lens has at least one inflection point. The optical imaging system according to claim 1, wherein the coordinate points on the object side of the first lens at a height of 1/2 HEP to the coordinate points on the image side of the seventh lens at a height of 1/2 HEP are parallel to the optical axis The horizontal distance is EIN; the thicknesses of the first lens to the seventh lens at a height of 1/2 HEP and parallel to the optical axis are ETP1, ETP2, ETP3, ETP4, ETP5, ETP6, and ETP7, the sum of the aforementioned ETP1 to ETP6 Is SETP, which satisfies the following formula: 0.2 ≦ SETP / EIN <1. The optical imaging system according to claim 1, wherein the horizontal distance from the coordinate point on the side of the seventh lens image at a height of 1/2 HEP to the first imaging surface parallel to the optical axis is EBL, and the seventh lens image The horizontal distance from the intersection between the side surface and the optical axis to the first imaging plane parallel to the optical axis is BL, which satisfies the following formula: 0.1 ≦ EBL / BL ≦ 1.5. The optical imaging system according to claim 1, further comprising an aperture, and a distance InS on the optical axis from the aperture to the first imaging plane, which satisfies the following formula: 0.2 ≦ InS / HOS ≦ 1.1. An optical imaging system includes: a first lens having a refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power A fifth lens with a refractive power; a sixth lens with a refractive power; a seventh lens with a refractive power; a first imaging plane; a visible light image plane perpendicular to the optical axis and its center The field of view has a maximum defocus modulation conversion contrast transfer ratio (MTF) at the first spatial frequency (110 cycles / mm); and a second imaging plane; it is a specific infrared light image plane perpendicular to the optical axis and its The central field of view has a maximum defocus modulation conversion contrast transfer rate (MTF) at the first spatial frequency (110 cycles / mm), where the optical imaging system has seven lenses with refractive power, and the optical imaging system is at the first The imaging plane has a maximum imaging height HOI perpendicular to the optical axis, at least one of the first lens to the seventh lens has a positive refractive power, and the focal lengths of the first lens to the seventh lens are f1, f2, f3, respectively. , F4, f5, f6 f7, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, the object lens side to the first imaging plane has a distance HOS on the optical axis, and the object side of the first lens to The image side of the seventh lens has a distance InTL on the optical axis, half of the maximum viewing angle of the optical imaging system is HAF, and the distance between the first imaging plane and the second imaging plane on the optical axis is FS. The horizontal distance from the coordinate point on the object side of the first lens at a height of 1/2 HEP to the first imaging plane parallel to the optical axis is ETL, and the coordinate point on the object side of the first lens at a height of 1/2 HEP to the The horizontal distance between the coordinate points on the image side of the seventh lens at a height of 1/2 HEP parallel to the optical axis is EIN, which meets the following conditions: 1.0 ≦ f / HEP ≦ 10.0; 0deg <HAF ≦ 150deg; | FS | ≦ 60μm And 0.2 ≦ EIN / ETL <1. The optical imaging system according to claim 10, wherein the modulation axis of the visible light on the first imaging surface, 0.3HOI, and 0.7HOI at a spatial frequency of 110 cycles / mm, and the modulation conversion contrast transfer rate (MTF value) are respectively MTFQ0, MTFQ3 and MTFQ7 indicate that it meets the following conditions: MTFQ0 ≧ 0.2; MTFQ3 ≧ 0.01; and MTFQ7 ≧ 0.01. The optical imaging system according to claim 10, wherein each of the lenses has an air gap. The optical imaging system according to claim 10, wherein a distance on the optical axis between the fourth lens and the fifth lens is IN45 and satisfies the following formula: 0 <IN45 / f ≦ 3.0. The optical imaging system according to claim 10, wherein a distance on the optical axis between the fifth lens and the sixth lens is IN56 and satisfies the following formula: 0 <IN56 / f ≦ 5. The optical imaging system according to claim 10, wherein the optical imaging system satisfies the following conditions: HOS / HOI ≧ 1.2. The optical imaging system according to claim 10, wherein at least one of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens has a wavelength smaller than 500nm light filter element. The optical imaging system according to claim 10, wherein a material of at least one of the first lens to the seventh lens is glass. The optical imaging system according to claim 10, wherein the distance between the sixth lens and the seventh lens on the optical axis is IN67, and the thicknesses of the sixth lens and the seventh lens on the optical axis are TP6 and TP7, which satisfies the following conditions: 0.1 ≦ (TP7 + IN67) / TP6 ≦ 50. An optical imaging system includes: a first lens having a refractive power; a second lens having a refractive power; a third lens having a refractive power; a fourth lens having a refractive power A fifth lens having a refractive power; a sixth lens having a refractive power; a seventh lens having a refractive power; a first average imaging plane; a visible light image plane perpendicular to the optical axis and set The average position of the out-of-focus position of each of the central field of view, 0.3 field of view, and 0.7 field of view of the optical imaging system at the first spatial frequency (110 cycles / mm) with the maximum MTF value of the field of view; and a second average Imaging plane; it is a specific infrared light image plane perpendicular to the optical axis and is set in the central field of view, 0.3 field of view, and 0.7 field of view of the optical imaging system, each of which has a first space frequency (110 cycles / mm). The average position of the out-of-focus position of the maximum MTF value of the field of view, where the optical imaging system has seven lenses with refractive power, and the optical imaging system has a maximum imaging height perpendicular to the optical axis on the first average imaging plane HOI, the focal lengths of the first lens to the seventh lens are f1, f2, f3, f4, f5, f6, f7, the focal length of the optical imaging system is f, and the entrance pupil diameter of the optical imaging system is HEP. The half of the maximum viewing angle of the optical imaging system is HAF. The distance from the object side of the first lens to the first average imaging plane is HOS on the optical axis. The object side of the first lens to the image side of the seventh lens are on the optical axis. With a distance InTL, the distance between the first average imaging surface and the second average imaging surface is AFS, and the thicknesses of the first lens to the seventh lens at a height of 1/2 HEP and parallel to the optical axis are ETP1, respectively. ETP2, ETP3, ETP4, ETP5, ETP6 and ETP7. The sum of the aforementioned ETP1 to ETP7 is SETP. The thicknesses of the first lens to the seventh lens on the optical axis are TP1, TP2, TP3, TP4, TP5, TP6 and TP7 The sum of the aforementioned TP1 to TP7 is STP, and at least one of the first lens to the seventh lens is made of glass, which satisfies the following conditions: 1 ≦ f / HEP ≦ 10; 0deg <HAF ≦ 150deg; | AFS | ≦ 60 μm and 0.5 ≦ SETP / STP <1. The optical imaging system according to claim 19, wherein the horizontal distance from the coordinate point on the object side of the first lens at a height of 1/2 HEP to the first average imaging plane and parallel to the optical axis is ETL, the first lens The horizontal distance between the coordinate point at the 1/2 HEP height on the object side and the coordinate point at the 1/2 HEP height on the seventh lens image side parallel to the optical axis is EIN, which satisfies the following conditions: 0.2 ≦ EIN / ETL <1. The optical imaging system according to claim 19, wherein each of the lenses has an air gap. The optical imaging system according to claim 19, wherein the optical imaging system satisfies the following conditions: HOS / HOI ≧ 1.6. The optical imaging system according to claim 19, wherein a linear magnification of the optical imaging system on the second average imaging plane is LM, which satisfies the following condition: LM ≧ 0.0003. The optical imaging system according to claim 19, wherein the optical imaging system further includes an aperture and an image sensing element, the image sensing element is disposed behind the first average imaging surface and at least 100,000 pixels, and There is a distance InS on the optical axis from the aperture to the first average imaging plane, which satisfies the following formula: 0.2 ≦ InS / HOS ≦ 1.1.