CN211506002U - Optical imaging system - Google Patents

Abstract

The utility model provides an optical imaging system contains first lens, second lens, third lens, fourth lens, fifth lens and sixth lens by thing side to picture side in proper order. At least one of the first lens element to the fifth lens element has positive refractive power. The sixth lens element with negative refractive power has two aspheric surfaces, and at least one of the surfaces of the sixth lens element has an inflection point. The lenses with refractive power in the optical imaging system are the first lens to the sixth lens. When the specific conditions are met, the optical imaging device can have larger light receiving capacity and better optical path adjusting capacity so as to improve the imaging quality.

Description

Optical imaging system

technical field

The utility model relates to an optical imaging system, and particularly relates to a miniaturized optical imaging system applied to electronic products.

Background technique

In recent years, with the rise of portable electronic products with photographic functions, the demand for optical systems is increasing day by day. The photosensitive components of general optical systems are nothing more than two types of photosensitive coupling components (Charge Coupled Device; CCD) or complementary metal-oxide semiconductor (Complementary Metal-Oxide Semiconductor Sensor; CMOS Sensor), and with the advancement of semiconductor process technology, The pixel size of the photosensitive component is reduced, and the optical system is gradually developed to the high-pixel field, so the requirements for image quality are also increasing.

Traditional optical systems mounted on portable devices mostly use four or five lens structures. However, due to the continuous improvement of pixels in portable devices and the demand for large apertures by end consumers, such as low-light and night shooting functions, conventional The optical imaging system has been unable to meet the requirements of higher-order photography.

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

Utility model content

The aspect of the embodiment of the present invention is directed to an optical imaging system, which can utilize the refractive power of six lenses and the combination of the convex and concave surfaces (the convex surface or the concave surface of the present invention refers to the distance between the object side or the image side of each lens in principle). The description of the geometric shape changes at different heights of the optical axis), thereby effectively improving the amount of light entering the optical imaging system, and at the same time improving the imaging quality, so that it can be applied to small electronic products.

The terms of the lens parameters related to the embodiments of the present utility model and their code numbers are listed as follows, as a reference for the subsequent description:

Lens parameters related to length or height

The utility model can select wavelength 555nm as the main reference wavelength and benchmark for measuring focus shift in visible light spectrum, and select wavelength 940nm as the main reference wavelength and benchmark for measuring focus shift in infrared light spectrum (700nm to 1300nm).

The optical imaging system has an infrared light imaging surface, and the infrared light imaging surface is a specific infrared light image plane perpendicular to the optical axis and its center field of view has a maximum defocus modulation conversion ratio (MTF) at the first spatial frequency. value.

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 object side of the first lens and the image side of the sixth lens of the optical imaging system is represented by InTL; the fixed aperture of the optical imaging system ( The distance between the aperture) and the infrared light 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 to indicate (instantiate).

Material Dependent Lens Parameters

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

Lens parameters related to viewing angle

The angle of view is expressed in AF; the half of the angle of view is expressed in HAF; the chief ray angle is expressed in MRA.

Lens parameters related to entrance and exit pupils

The entrance pupil diameter of the optical imaging system is represented by HEP; the exit pupil diameter of the sixth lens is represented by HXP; the maximum effective radius of any surface of a single lens refers to the maximum angle of view of the system. Surface intersection (Effective Half Diameter; EHD), the vertical height between this 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 a similar manner.

Parameters related to the depth of the lens surface

From the intersection of the object side of the sixth lens on the optical axis to the end point of the maximum effective radius of the object side of the sixth lens, the distance between the aforementioned two points horizontal to the optical axis is represented by InRS61 (the depth of the maximum effective radius); the image side of the sixth lens From the intersection point on the optical axis to the end point of the maximum effective radius of the image side surface of the sixth lens, the distance between the aforementioned two points horizontal to the optical axis is represented by InRS62 (maximum effective radius depth). The representation of the depth (sinking amount) of the maximum effective radius of the object side or image side of other lenses is as described above.

Parameters related to the lens surface

The critical point C refers to a point on the surface of a specific lens that is tangent to a tangent plane perpendicular to the optical axis, except for the intersection with the optical axis. On the other hand, 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 surface and the optical axis is HVT61 (illustration), and the vertical distance between the critical point C62 on the side of the sixth lens image and the optical axis is HVT62 (illustration). The representations of the critical points on the object side or image side of other lenses and their vertical distances from the optical axis are as described above.

The inflection point closest to the optical axis on the object side of the sixth lens is IF611, the subsidence of this point is SGI611 (example), SGI611 is the intersection of the sixth lens object side on the optical axis to the sixth lens object side The closest optical axis The horizontal displacement distance between the inflection points parallel to the optical axis, IF611, the vertical distance between this point and the optical axis is HIF611 (example). The inflection point closest to the optical axis on the image side of the sixth lens is IF621, the subsidence at this point is SGI621 (example), and SGI611 is the intersection of the image side of the sixth lens on the optical axis to the closest optical axis of the image side of the sixth lens. The horizontal displacement distance between the inflection points and the optical axis parallel to the optical axis, IF621 The vertical distance between this point and the optical axis is HIF621 (example).

The second inflection point on the object side of the sixth lens close to the optical axis is IF612, the subsidence of this point is SGI612 (example), SGI612 is the intersection of the object side of the sixth lens on the optical axis to the second closest point on the object side of the sixth lens The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, IF612 The vertical distance between this point and the optical axis is HIF612 (example). The second inflection point on the image side of the sixth lens close to the optical axis is IF622, the subsidence of this point is SGI622 (example), SGI622 is the intersection of the image side of the sixth lens on the optical axis to the second close to the image side of the sixth lens The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, IF622 The vertical distance between this point and the optical axis is HIF622 (example).

The third inflection point on the object side of the sixth lens close to the optical axis is IF613, the subsidence of this point is SGI613 (example), SGI613 is the intersection of the sixth lens object side on the optical axis to the sixth lens object side The third closest point The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, IF613 The vertical distance between this point and the optical axis is HIF613 (example). The third inflection point on the image side of the sixth lens close to the optical axis is IF623, the subsidence of this point is SGI623 (example), and SGI623 is the intersection of the image side of the sixth lens on the optical axis to the third closest to the image side of the sixth lens. The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, IF623 The vertical distance between this point and the optical axis is HIF623 (example).

The fourth inflection point on the object side of the sixth lens close to the optical axis is IF614, the subsidence of this point is SGI614 (example), SGI614 is the intersection of the sixth lens object side on the optical axis to the sixth lens object side The fourth closest point The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, the vertical distance between this point and the optical axis of IF614 is HIF614 (example). The inflection point of the fourth close to the optical axis on the image side of the sixth lens is IF624, and the subsidence of this point is SGI624 (example), SGI624 is the intersection of the sixth lens image side on the optical axis to the sixth lens image side fourth close The horizontal displacement distance between the inflection points of the optical axis parallel to the optical axis, IF624 The vertical distance between this point and the optical axis is HIF624 (example).

The inflection points on the object side or image side of other lenses and their vertical distances from the optical axis or their subsidences are expressed in the same way as described above.

variables related to aberrations

The optical distortion (Optical Distortion) of the optical imaging system is represented by ODT; its TV distortion (TVDistortion) is represented by TDT, and can be further defined to describe the degree of aberration shift between 50% and 100% of the imaging field; spherical aberration shift The amount is expressed in DFS; the comet aberration offset 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 axis of the modulation transfer function characteristic graph represents the contrast transfer rate (values from 0 to 1), and the horizontal axis represents the spatial frequency (cycles/mm; lp/mm; line pairs permm). A perfect imaging system can theoretically present 100% of the line contrast of the subject. However, in an actual imaging system, the value of the contrast transfer rate on the vertical axis is less than 1. In addition, it is generally more difficult to obtain a fine degree of restoration in the edge area of the image than in the center area. Infrared light spectrum On the infrared light imaging plane, the optical axis, 0.3 field of view and 0.7 field of view three contrast transfer rates (MTF values) at a spatial frequency of 55 cycles/mm are represented by MTFE0, MTFE3 and MTFE7, respectively. The optical axis, 0.3 field of view And the contrast transfer rate (MTF value) of 0.7 field of view three at a spatial frequency of 110cycles/mm is represented by MTFQ0, MTFQ3 and MTFQ7, respectively, and the optical axis, 0.3 field of view and 0.7 field of view. MTF value) are represented by MTFH0, MTFH3 and MTFH7 respectively, and the contrast transfer rate (MTF value) of the optical axis, 0.3 field of view and 0.7 field of view at a spatial frequency of 440 cycles/mm are represented by MTF0, MTF3 and MTF7 respectively. The field of view is representative of the center of the lens, the inner field of view, and the outer field of view, so it can be used to evaluate the performance of a particular optical imaging system. If the design of the optical imaging system corresponds to the pixel size (Pixel Size) containing photosensitive components below 1.12 microns, the quarter spatial frequency, half spatial frequency (half frequency) and full spatial frequency (full spatial frequency) of the modulation transfer function characteristic diagram frequency) at least 110cycles/mm, 220cycles/mm and 440cycles/mm respectively.

If the optical imaging system also needs to meet the imaging of the infrared spectrum, such as for night vision with low light sources, the working wavelength used can be 840nm to 960nm. Since the main function is to identify the outline of objects formed by black and white light and shade, high resolution is not required. Therefore, it is only necessary to select a spatial frequency less than 110 cycles/mm to evaluate whether a specific optical imaging system has excellent performance in the infrared spectrum. When the working wavelength of 940nm is focused on the infrared imaging surface, the contrast transfer rate (MTF value) of the image on the optical axis, 0.3 field of view and 0.7 field of view at a spatial frequency of 55 cycles/mm is represented by MTFE0, MTFE3 and MTFE7, respectively.

The utility model provides an optical imaging system, wherein the object side or the image side of the sixth lens can be provided with an inflection point, which can effectively adjust the angle of each field of view incident on the sixth lens, and correct the optical distortion and TV distortion. . In addition, the surface of the sixth lens may have better optical path adjustment capability to improve image quality.

According to the utility model, an optical imaging system is provided, which sequentially includes a first lens with refractive power from an object side to an image side; a second lens with refractive power; a third lens with refractive power; and a fourth lens with refractive power ; the fifth lens, with refractive power; the sixth lens, with refractive power; and the infrared imaging surface; wherein, the optical imaging system has six lenses with refractive power, and the first lens to the At least one lens in the sixth lens has a positive refractive power, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, the image side exit pupil diameter of the sixth lens is HXP, The half of the maximum viewing angle of the optical imaging system is HAF, and the thicknesses of the first lens to the sixth lens at 1/2HXP height and parallel to the optical axis are ETP1, ETP2, ETP3, ETP4 respectively , ETP5 and ETP6, the sum of the aforementioned ETP1 to ETP6 is SETP, the thicknesses of the first lens to the sixth lens on the optical axis are TP1, TP2, TP3, TP4, TP5 and TP6 respectively, the aforementioned TP1 to TP6 The sum of is STP, which satisfies the following conditions: 0.5≤f/HEP≤1.8; 0deg<HAF≤50deg, and 0.2≤SETP/STP<1.

Preferably, the wavelength of the infrared light is between 700 nm and 1300 nm and the first spatial frequency is represented by SP1, which satisfies the following condition: SP1≤440cycles/mm.

Preferably, the wavelength of the infrared light is between 850 nm and 960 nm and the first spatial frequency is represented by SP1, which satisfies the following condition: SP1≤220cycles/mm.

Preferably, the horizontal distance parallel to the optical axis between the coordinate point on the object side of the first lens at 1/2 HEP height and the infrared imaging plane is ETL, and the object side of the first lens is 1 The horizontal distance parallel to the optical axis between the coordinate point at /2HEP height and the coordinate point at 1/2HEP height on the image side of the sixth lens is EIN, which satisfies the following conditions: 0.2≤EIN/ETL<1.

Preferably, the horizontal distance parallel to the optical axis between the coordinate point on the object side of the first lens at 1/2HEP height to the coordinate point on the image side of the sixth lens at 1/2HEP height is EIN, which is The following formula is satisfied: 0.2≤SETP/EIN<1.

Preferably, the distance on the optical axis between the first lens and the second lens is IN12, and the distance on the optical axis between the third lens and the fourth lens is IN34 , which satisfies the following conditions: IN12>IN34.

Preferably, the distance on the optical axis between the fourth lens and the fifth lens is IN45, and the distance on the optical axis between the fifth lens and the sixth lens is IN56 , which satisfies the following conditions: IN56>IN45.

Preferably, the distance on the optical axis between the third lens and the fourth lens is IN34, and the distance on the optical axis between the fourth lens and the fifth lens is IN45 , which satisfies the following conditions: IN45>IN34.

Preferably, it further includes an aperture, and there is a distance InS between the aperture and the infrared light imaging surface on the optical axis, and the object side of the first lens to the infrared light imaging surface is on the optical axis There is a distance HOS that satisfies the following formula: 0.2≤InS/HOS≤1.1.

According to the present invention, an optical imaging system is further provided, which includes a first lens with a refractive power, a second lens with a refractive power, a third lens with a refractive power, and a fourth lens with a refractive power in order from the object side to the image side. a fifth lens with refractive power; a sixth lens with refractive power; and an infrared imaging surface; wherein, the optical imaging system has six lenses with refractive power, and the first lens to the At least one surface of at least one lens in the sixth lens has at least one inflection point, at least one lens in the first lens to the sixth lens has a positive refractive power, and the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, the exit pupil diameter of the sixth lens is HXP, the half of the maximum viewing angle of the optical imaging system is HAF, and the sixth lens is HAF. The horizontal distance parallel to the optical axis between the coordinate point on the object side of a lens at 1/2HXP height and the infrared imaging surface is ETL, and the coordinate point on the object side of the first lens at 1/2HXP height to The horizontal distance parallel to the optical axis between the coordinate points on the image side of the sixth lens at a height of 1/2HXP is EIN, which satisfies the following conditions: 0.5≤f/HEP≤1.5; 0deg<HAF≤50deg and 0.2≤EIN /ETL<1.

Preferably, the optical imaging system has a maximum imaging height HOI on the infrared light imaging plane perpendicular to the optical axis, and the optical axis, 0.3HOI and 0.7HOI of the infrared light on the infrared light imaging plane are three The modulation conversion versus transfer ratio at a spatial frequency of 110 cycles/mm is represented by MTFQ0, MTFQ3, and MTFQ7, respectively, which satisfy the following conditions: MTFQ0≥0.01; MTFQ3≥0.01; and MTFQ7≥0.01.

Preferably, the optical imaging system has a maximum imaging height HOI on the infrared light imaging surface perpendicular to the optical axis, and the first lens object side to the infrared light imaging surface has a maximum imaging height on the optical axis. A distance HOS that satisfies the following conditions: 0.5≤HOS/HOI≤6.

Preferably, it further includes an aperture, and the aperture is located in front of the image side surface of the third lens.

Preferably, the image side of the second lens is convex on the optical axis.

Preferably, the object side of the fifth lens is convex on the optical axis.

Preferably, the object side of the fourth lens is convex on the optical axis and the image side is convex on the optical axis.

Preferably, the image side of the fourth lens is convex on the optical axis.

Preferably, all the lenses in the first lens to the sixth lens are made of plastic material.

Preferably, the optical imaging system satisfies the following conditions: 0.5≤f/HEP≤1.4.

According to the present utility model, an optical imaging system is further provided, which sequentially includes a first lens having a refractive power from an object side to an image side; a second lens having a refractive power; a third lens having a refractive power; and a fourth lens having a refractive power a fifth lens with refractive power; a sixth lens with refractive power; and an infrared imaging surface; wherein, the optical imaging system has six lenses with refractive power, and the first lens to the At least two of the fifth lenses have at least one inflection point on their respective surfaces, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, and the first The diameter of the exit pupil of the six-lens image side is HXP, the half of the maximum viewing angle of the optical imaging system is HAF, and the thickness of the first lens to the sixth lens is 1/2HEP height and parallel to the optical axis, respectively. are ETP1, ETP2, ETP3, ETP4, ETP5 and ETP6, the sum of the aforementioned ETP1 to ETP6 is SETP, and the thicknesses of the first lens to the sixth lens on the optical axis are respectively TP1, TP2, TP3, TP4, TP5 and TP6, the sum of the aforementioned TP1 to TP6 is STP, which satisfies the following conditions: 0.5≤f/HEP≤1.3; 0deg<HAF≤45deg; and 0.2≤SETP/STP<1.

Preferably, there is a distance HOS on the optical axis between the object side of the first lens and the infrared imaging surface, and the optical imaging system satisfies the following formula: 0mm<HOS≤20mm.

Preferably, the wavelength of the infrared light is between 850 nm and 960 nm and the first spatial frequency is represented by SP1, which satisfies the following condition: SP1≤220cycles/mm.

Preferably, the materials of the first lens to the fifth lens are all plastic.

Preferably, the distance on the optical axis between the first lens and the second lens is IN12, and the distance on the optical axis between the second lens and the third lens is IN23 , the distance on the optical axis between the third lens and the fourth lens is IN34, the distance between the fourth lens and the fifth lens on the optical axis is IN45, so The distance on the optical axis between the fifth lens element and the sixth lens element is IN56, which satisfies the following conditions: IN12>IN34; IN45>IN34; and IN56>IN45.

Preferably, the optical imaging system further includes an aperture and an image sensing component, and the image sensing component is disposed behind the infrared light imaging surface and has at least 100,000 pixels, and is located between the aperture and the aperture. The infrared light imaging surface has a distance InS on the optical axis, and the first lens object side to the infrared light imaging surface has a distance HOS on the optical axis, which satisfies the following formula: 0.2≤InS/ HOS≤1.1.

The thickness of a single lens at the height of 1/2 entrance pupil diameter (HEP) especially affects the correction aberration in the shared area of each light field within the 1/2 entrance pupil diameter (HEP) range and the optical path difference between the rays of each field of view. The greater the thickness, the better the ability to correct aberrations. However, at the same time, it will increase the difficulty of production. Therefore, it is necessary to control the thickness of a single lens at the height of 1/2 entrance pupil diameter (HEP). The ratio (ETP/TP) between the thickness (ETP) of the 1/2 entrance pupil diameter (HEP) height and the thickness (TP) of the lens on the optical axis to which the surface belongs. For example, the thickness of the first lens at 1/2 entrance pupil diameter (HEP) height is denoted by ETP1. The thickness of the second lens at 1/2 entrance pupil diameter (HEP) height is denoted by ETP2. The thickness of the remaining lenses in the optical imaging system at 1/2 entrance pupil diameter (HEP) height, and so on. The sum of the aforementioned ETP1 to ETP6 is SETP, and the embodiment of the present invention can satisfy the following formula: 0.2≤SETP/EIN<1.

In order to balance the ability to improve the ability to correct aberrations and reduce the difficulty in manufacturing, it is particularly necessary to control the thickness (ETP) of the lens at the height of 1/2 entrance pupil diameter (HEP) and the thickness of the lens on the optical axis (TP). ) proportional relationship (ETP/TP). For example, the thickness of the first lens at 1/2 entrance pupil diameter (HEP) height 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 entrance pupil diameter (HEP) height 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 remaining lenses in the optical imaging system at the height of 1/2 entrance pupil diameter (HEP) and the thickness of the lens on the optical axis (TP), and so on. The embodiment of the present invention can satisfy the following formula: 0.2≤ETP/TP≤3.

The horizontal distance between two adjacent lenses at the height of 1/2 entrance 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 entrance pupil diameter (HEP). ) The ability to correct aberrations in the shared area of each field of view and the optical path difference between each field of view. The greater the horizontal distance, the more likely the ability to correct aberrations will be. However, it will also increase the difficulty in manufacturing. Therefore, the horizontal distance (ED) at 1/2 entrance pupil diameter (HEP) height of specific adjacent two lenses must be controlled.

In order to balance the ability to improve the ability to correct aberrations and reduce the difficulty of "miniaturizing" 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 entrance 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 1/2 entrance pupil diameter (HEP) height is represented by ED12, 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 entrance pupil diameter (HEP) height 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 in the optical imaging system at 1/2 entrance pupil diameter (HEP) height and the horizontal distance of the adjacent two lenses on the optical axis, and so on.

The horizontal distance parallel to the optical axis between the coordinate point on the image side of the sixth lens at 1/2HEP height and the infrared light imaging surface is EBL, and the intersection of the sixth lens image side and the optical axis to the infrared light imaging surface The horizontal distance parallel to the optical axis is BL, and the embodiment of the present invention can satisfy the following formula: 0.2≤SETP/EIN<1 in order to balance the ability to improve the correction of aberrations and reserve the accommodation space of other optical components at the same time. The optical imaging system may further include a filter element, the filter element is located between the sixth lens and the infrared light imaging surface, and the sixth lens image side of the coordinate point at 1/2HEP height is between the filter element The distance parallel to the optical axis is EIR, and the distance parallel to the optical axis between the intersection of the sixth lens image side and the optical axis to the filter assembly is PIR, and the embodiment of the present utility model can satisfy the following formula: 0.1≤EIR /PIR≤1.1.

When ∣f1∣>∣f6∣, the overall height of the optical imaging system (HOS; Height of Optic System) can be appropriately shortened to achieve the purpose of miniaturization.

When ∣f2∣+∣f3∣+∣f4∣+∣f5∣>∣f1∣+∣f6∣ meets the above conditions, at least one lens from the second lens to the fifth lens has a weak positive refractive power or a weak Negative bending force. The so-called weak refractive power means that the absolute value of the focal length of a specific lens is greater than 10mm. When at least one lens among the second lens to the fifth lens of the present invention has a weak positive refractive power, it can effectively share the positive refractive power of the first lens and avoid unnecessary aberrations from appearing prematurely. If at least one lens in the fifth lens has a weak negative refractive power, the aberration of the system can be fine-tuned and corrected.

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

Description of drawings

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

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

2 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the first embodiment of the present invention in sequence from left to right;

FIG. 3 is a characteristic diagram of visible light spectrum modulation and conversion of the optical imaging system of the present embodiment;

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

5 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the second embodiment of the present invention from left to right;

FIG. 6 is a characteristic diagram of infrared spectrum modulation and conversion of the optical imaging system of the present embodiment;

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

8 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the third embodiment of the present invention from left to right;

FIG. 9 is a characteristic diagram of infrared spectrum modulation and conversion of the optical imaging system of the present embodiment;

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

11 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the fourth embodiment of the present invention from left to right;

FIG. 12 is a characteristic diagram of infrared spectrum modulation conversion of the optical imaging system of the present embodiment;

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

14 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the fifth embodiment of the present invention from left to right;

FIG. 15 is a characteristic diagram of infrared spectrum modulation conversion of the optical imaging system of this embodiment;

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

FIG. 17 shows graphs of spherical aberration, astigmatism and optical distortion of the optical imaging system according to the sixth embodiment of the present invention from left to right;

FIG. 18 is a characteristic diagram of infrared spectrum modulation and conversion of the optical imaging system of this embodiment.

Symbol Description

10, 20, 30, 40, 50, 60: Optical Imaging Systems

100, 200, 300, 400, 500, 600: Aperture

110, 210, 310, 410, 510, 610: First lens

112, 212, 312, 412, 512, 612: Object side

114, 214, 314, 414, 514, 614: like the side

120, 220, 320, 420, 520, 620: Second lens

122, 222, 322, 422, 522, 622: Object side

124, 224, 324, 424, 524, 624: like the side

130, 230, 330, 430, 530, 630: Third lens

132,232,332,432,532,632: Object side

134, 234, 334, 434, 534, 634: like the side

140, 240, 340, 440, 540, 640: Fourth lens

142,242,342,442,542,642: Object side

144, 244, 344, 444, 544, 644: like the side

150, 250, 350, 450, 550, 650: Fifth lens

152,252,352,452,552,652: Object side

154, 254, 354, 454, 554, 654: like the side

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

162,262,362,462,562,662: Object side

164, 264, 364, 464, 564, 664: like the side

180, 280, 380, 480, 580, 680: Infrared filter

190,290,390,490,590,690: Infrared imaging surface

192,292,392,492,592,692: Image Sensing Components

f: The focal length of the optical imaging system

f1f2f3f4f5f6: The focal length of the first lens to the sixth lens

f/HEP, Fno, F#: Aperture value of optical imaging system

HAF: Half of the maximum viewing angle of the optical imaging system

NA1, NA2, NA3, NA4, NA5, NA6: Dispersion coefficients of the first lens to the sixth lens

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

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

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

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

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

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

TP1, TP2, TP3, TP4, TP5, TP6: the thickness of the first lens to the sixth lens on the optical axis

ΣTP: the sum of the thicknesses of all lenses with refractive power

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

InRS61: The horizontal displacement distance from the intersection of the object side of the sixth lens on the optical axis to the maximum effective radius of the object side of the sixth lens on the optical axis

IF611: The inflection point closest to the optical axis on the object side of the sixth lens; SGI611: The amount of subsidence at this point

HIF611: The vertical distance between the inflection point closest to the optical axis on the object side of the sixth lens and the optical axis

IF621: The inflection point closest to the optical axis on the image side of the sixth lens; SGI621: The amount of subsidence at this point

HIF621: The vertical distance between the inflection point closest to the optical axis on the image side of the sixth lens and the optical axis

IF612: The second inflection point on the object side of the sixth lens close to the optical axis; SGI612: The amount of subsidence at this point

HIF612: The vertical distance between the second inflection point close to the optical axis on the object side of the sixth lens and the optical axis

IF622: The second inflection point on the image side of the sixth lens that is close to the optical axis; SGI622: The amount of subsidence at this point

HIF622: The vertical distance between the second inflection point close to the optical axis on the image side of the sixth lens and the optical axis

C61: Critical point on the object side of the sixth lens

C62: Critical point on the image side of the sixth lens

SGC61: The horizontal displacement distance between the critical point on the object side of the sixth lens and the optical axis

SGC62: The horizontal displacement distance between the critical point on the image side of the sixth lens and the optical axis

HVT61: The vertical distance between the critical point on the object side of the sixth lens and the optical axis

HVT62: The vertical distance between the critical point on the image side of the sixth lens and the optical axis

HOS: total height of the system (the distance from the object side of the first lens to the infrared imaging surface on the optical axis)

Dg: the diagonal length of the image sensing element

InS: the distance from the aperture to the infrared light imaging surface

InTL: the distance from the object side of the first lens to the image side of the sixth lens

InB: the distance from the image side of the sixth lens to the infrared imaging surface

HOI: Half of the diagonal length of the effective sensing area of the image sensing component (maximum image height)

TDT: TV Distortion of Optical Imaging System in Imaging

ODT: Optical Distortion of the Optical Imaging System During Imaging

Detailed ways

An optical imaging system includes a first lens with refractive power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and an infrared imaging surface in sequence from the object side to the image side. The optical imaging system may further include an image sensing element disposed on the infrared light imaging surface.

The optical imaging system can be designed using three infrared operating wavelengths, namely 850nm, 940nm, and 960nm, of which 960nm is the main reference wavelength and is the reference wavelength for the main extraction technical features.

The optical imaging system can be designed with three working wavelengths of visible light, 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 with five working wavelengths, 470nm, 510nm, 555nm, 610nm, and 650nm, of which 555nm is the main reference wavelength, which is the reference wavelength for extracting visible light 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 ΣPPR, and the sum of NPR of all lenses with negative refractive power is ΣNPR, which helps to control the total refractive power and total length of the optical imaging system when the following conditions are met: 0.5≤ΣPPR/∣ΣNPR∣≤15, preferably , which can satisfy the following conditions: 1≤ΣPPR/∣ΣNPR∣≤3.0.

The optical imaging system may further include an image sensing component disposed on the infrared light imaging surface. The half of the diagonal length of the effective sensing area of the image sensing element (that is, the imaging height or the maximum image height of the optical imaging system) is HOI, and the distance from the object side of the first lens to the infrared imaging surface on the optical axis is HOS , which satisfies the following conditions: HOS/HOI≤50; and 0.5≤HOS/f≤150. Preferably, the following conditions may be satisfied: 0.5≤HOS/HOI≤6; and 1≤HOS/f≤140. In this way, the miniaturization of the optical imaging system can be maintained so as to be mounted on thin and light portable electronic products.

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

In the optical imaging system of the present invention, the aperture configuration can 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 infrared light imaging surface. If the aperture is a front aperture, a longer distance between the exit pupil of the optical imaging system and the infrared light imaging surface can be created to accommodate more optical components, and the efficiency of the image sensing component to receive images can be increased; if it is a central aperture , the system helps 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 aperture to the infrared light imaging surface is InS, which satisfies the following conditions: 0.2≤InS/HOS≤1.1. Thereby, the miniaturization of the optical imaging system and the characteristics of having a wide angle can be maintained at the same time.

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 sixth lens is InTL, and the sum of the thicknesses of all lenses with refractive power on the optical axis is ΣTP, which satisfies the following conditions: 0.1≤ΣTP /InTL≤0.9. In this way, the contrast of system imaging and the yield of lens manufacturing can be taken into account at the same time, and an appropriate back focal length can be provided to accommodate other components.

The radius of curvature of the object side of the first lens is R1, and the radius of curvature of the image side of the first lens is R2, which satisfy the following conditions: 0.001≤∣R1/R2∣≤25. In this way, the first lens has an appropriate positive refractive power to prevent the spherical aberration from increasing too quickly. Preferably, the following conditions can be satisfied: 0.01≤∣R1/R2∣<12.

The radius of curvature of the object side of the sixth lens is R11, and the radius of curvature of the image side of the sixth lens is R12, which satisfy the following conditions: -7<(R11-R12)/(R11+R12)<50. Thereby, it 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 condition: IN12/f≤60. Thereby, it helps to improve the chromatic aberration of the lens to improve its performance.

The distance between the fifth lens and the sixth lens on the optical axis is IN56, which satisfies the following condition: IN56/f≤3.0, which helps to improve the chromatic aberration of the lens and 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. Thereby, it is helpful to control the sensitivity and improve the performance of the optical imaging system manufacturing.

The thicknesses of the fifth lens and the sixth lens on the optical axis are TP5 and TP6 respectively, and the distance between the two lenses on the optical axis is IN56, which satisfies the following conditions: 0.1≤(TP6+IN56)/TP5≤15. Thereby, it helps to control the sensitivity of the optical imaging system manufacture and reduce the overall height of the system.

The thickness of the fourth lens on the optical axis is TP4, the distance between the third lens and the fourth lens on the optical axis is IN34, and the distance between the fourth lens and the fifth lens on the optical axis is IN45, which meets the following conditions : 0.1≤TP4/(IN34+TP4+IN45)<1. Thereby, it helps to slightly correct the aberration caused by the traveling process of the incident light layer by layer and reduce the overall height of the system.

In the optical imaging system of the present invention, the vertical distance between the critical point C61 on the object side of the sixth lens and the optical axis is HVT61, the vertical distance between the critical point C62 on the image side of the sixth lens and the optical axis is HVT62, and the object side of the sixth lens is HVT62. The horizontal displacement distance from the intersection on the optical axis to the critical point C61 on the optical axis is SGC61, and the horizontal displacement distance from the intersection of the image side of the sixth lens on the optical axis to the critical point C62 on the optical axis is SGC62, which can satisfy the following Conditions: 0mm≤HVT61≤3mm; 0mm<HVT62≤6mm; 0≤HVT61/HVT62; 0mm≤∣SGC61∣≤0.5mm; 0mm<∣SGC62∣≤2mm; and 0<∣SGC62∣/(∣SGC62∣+TP6 )≤0.9. Thereby, the aberration of the off-axis field of view can be effectively corrected.

The optical imaging system of the utility model satisfies the following conditions: 0.2≤HVT62/HOI≤0.9. Preferably, the following conditions may be satisfied: 0.3≤HVT62/HOI≤0.8. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

The optical imaging system of the utility model satisfies the following conditions: 0≤HVT62/HOS≤0.5. Preferably, the following conditions may be satisfied: 0.2≤HVT62/HOS≤0.45. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

In the optical imaging system of the present invention, the horizontal displacement distance parallel to the optical axis between the intersection of the object side of the sixth lens on the optical axis and the inflection point of the closest optical axis on the object side of the sixth lens is represented by SGI611, and the sixth lens is represented by SGI611. The horizontal displacement distance parallel to the optical axis between the intersection of the mirror image side on the optical axis and the inflection point of the nearest optical axis on the image side of the sixth lens is represented by SGI621, which satisfies the following conditions: 0<SGI611/(SGI611+TP6)≤ 0.9; 0<SGI621/(SGI621+TP6)≤0.9. Preferably, the following conditions may be satisfied: 0.1≤SGI611/(SGI611+TP6)≤0.6; 0.1≤SGI621/(SGI621+TP6)≤0.6.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the sixth lens on the optical axis and the second inflection point of the object side of the sixth lens close to the optical axis is represented by SGI612. The image side of the sixth lens is on the optical axis. The horizontal displacement distance parallel to the optical axis between the intersection point and the second inflection point on the image side of the sixth lens close to the optical axis is represented by SGI622, which satisfies the following conditions: 0<SGI612/(SGI612+TP6)≤0.9; 0<SGI622 /(SGI622+TP6)≤0.9. Preferably, the following conditions may be satisfied: 0.1≤SGI612/(SGI612+TP6)≤0.6; 0.1≤SGI622/(SGI622+TP6)≤0.6.

The vertical distance between the inflection point of the nearest optical axis on the object side of the sixth lens and the optical axis is represented by HIF611, the intersection point of the sixth lens' image side on the optical axis to the inflection point of the sixth lens' image side of the nearest optical axis and the optical axis The vertical distance between them is represented by HIF621, which meets the following conditions: 0.001mm≤∣HIF611∣≤5mm; 0.001mm≤∣HIF621∣≤5mm. Preferably, the following conditions can be satisfied: 0.1mm≤∣HIF611∣≤3.5mm; 1.5mm≤∣HIF621∣≤3.5mm.

The vertical distance between the second inflection point on the object side of the sixth lens close to the optical axis and the optical axis is represented by HIF612. The vertical distance between the point and the optical axis is represented by HIF622, which meets the following conditions: 0.001mm≤∣HIF612∣≤5mm; 0.001mm≤∣HIF622∣≤5mm. Preferably, the following conditions can be satisfied: 0.1mm≤∣HIF622∣≤3.5mm; 0.1mm≤∣HIF612∣≤3.5mm.

The vertical distance between the third inflection point on the object side of the sixth lens close to the optical axis and the optical axis is represented by HIF613. The vertical distance between the point and the optical axis is represented by HIF623, which meets the following conditions: 0.001mm≤∣HIF613∣≤5mm; 0.001mm≤∣HIF623∣≤5mm. Preferably, the following conditions can be satisfied: 0.1mm≤∣HIF623∣≤3.5mm; 0.1mm≤∣HIF613∣≤3.5mm.

The vertical distance between the fourth inflection point on the object side of the sixth lens close to the optical axis and the optical axis is represented by HIF614. The vertical distance between the point and the optical axis is represented by HIF624, which meets the following conditions: 0.001mm≤∣HIF614∣≤5mm; 0.001mm≤∣HIF624∣≤5mm. Preferably, the following conditions can be satisfied: 0.1mm≤∣HIF624∣≤3.5mm; 0.1mm≤∣HIF614∣≤3.5mm.

In one embodiment of the optical imaging system of the present invention, lenses with high dispersion coefficient and low dispersion coefficient can be arranged alternately to help correct the chromatic aberration of the optical imaging system.

The equation system for 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 along the optical axis at the position of height h with the surface vertex as a reference, k is the cone coefficient, c is the reciprocal 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 utility model, the material of the lens can be plastic or glass. When the lens material is plastic, the production cost and weight can be effectively reduced. 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 lens to the sixth lens in the optical imaging system can be aspherical, which can obtain more control variables. In addition to reducing aberrations, compared with the use of traditional glass lenses, even 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, it means that the lens surface is convex at the near-optical axis; if the lens surface is concave, in principle, it means that the lens surface is concave at the near-optical axis. .

The optical imaging system of the utility model can be applied to the optical system of moving focusing according to the requirements, and has the characteristics of excellent aberration correction and good imaging quality, thereby expanding the application level.

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

In the optical imaging system of the present invention, at least one lens among the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens can be a light filtering component with a wavelength of less than 500 nm according to the requirements. This can be achieved by coating at least one surface of the specific lens with filtering function or the lens itself is made of a material that can filter short wavelengths.

The infrared light imaging surface of the optical imaging system of the present invention can be selected as a plane or a curved surface according to requirements. When the infrared light imaging surface is a curved surface (such as a spherical surface with a radius of curvature), it helps to reduce the incident angle required to focus light on the infrared light imaging surface, in addition to helping to achieve the length of the miniature optical imaging system (TTL) , which is helpful for improving the relative illumination at the same time.

The optical imaging system of the present invention can be applied to three-dimensional image capture, through which light with specific characteristics is projected onto an object, and after being reflected on the surface of the object, it is received by the lens and analyzed by calculation to obtain the distance between each position of the object and the lens, Further, the information of the stereoscopic image is determined. The projected light mostly uses infrared rays in a specific band to reduce interference and achieve more accurate measurement. The aforementioned 3D sensing method of stereoscopic image capture may use technology such as time-of-flight (TOF) or structured light, but is not limited thereto.

According to the above-mentioned embodiments, specific embodiments are provided below and described in detail with reference to the drawings.

first embodiment

Please refer to FIG. 1 , FIG. 2 and FIG. 3 , wherein FIG. 1 is a schematic diagram of an optical imaging system according to the first embodiment of the present invention, and FIG. 2 shows the optical imaging system of the first embodiment from left to right. Curves of spherical aberration, astigmatism and optical distortion. FIG. 3 is a characteristic diagram of visible light spectrum modulation and conversion of the optical imaging system of the present embodiment. 1 , the optical imaging system 10 includes a first lens 110, an aperture 100, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, The infrared filter 180 , the infrared light imaging surface 190 and the image sensing component 192 .

The first lens 110 has a negative refractive power and is made of plastic material. The object side 112 is concave, the image side 114 is concave, and both are aspherical, and the object side 112 has two inflection points. The thickness of the first lens on the optical axis is TP1, and the thickness of the first lens at the height of 1/2 entrance pupil diameter (HEP) is represented by 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 inflection point of the closest optical axis on 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 parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the first lens is represented by SGI121, which satisfies the following conditions: SGI111=-0.0031mm; ∣SGI111∣/(∣SGI111∣+TP1)=0.0016 .

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 second inflection point close to the optical axis on the object side of the first lens is represented by SGI112. The image side of the first lens is on the optical axis. The horizontal displacement distance parallel to the optical axis between the intersection point and the second inflection point close to the optical axis on the image side of the first lens is represented by SGI122, which satisfies the following conditions: SGI112=1.3178mm; ∣SGI112∣/(∣SGI112∣+TP1 )=0.4052.

The vertical distance between the inflection point of the closest optical axis on the object side of the first lens and the optical axis is represented by HIF111. The vertical distance between them is represented by HIF121, which satisfies the following conditions: HIF111=0.5557mm; HIF111/HOI=0.1111.

The vertical distance between the second inflection point on the object side of the first lens close to the optical axis and the optical axis is represented by HIF112. The vertical distance between the point and the optical axis is represented by HIF122, which satisfies the following conditions: HIF112=5.3732mm; HIF112/HOI=1.0746.

The second lens 120 has a positive refractive power and is made of plastic material. The object side 122 is convex, the image side 124 is convex, and both are aspherical, and the object side 122 has an inflection point. The thickness of the second lens on the optical axis is TP2, and the thickness of the second lens at the height of 1/2 entrance pupil diameter (HEP) is represented by ETP2.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the second lens on the optical axis and the inflection point of the closest optical axis on the object side of the second lens is represented by SGI211. The intersection of the image side of the second lens on the optical axis to The horizontal displacement distance parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the second lens is represented by SGI221, which satisfies the following conditions: SGI211=0.1069mm; ∣SGI211∣/(∣SGI211∣+TP2)=0.0412; SGI221=0mm; ∣SGI221∣/(∣SGI221∣+TP2)=0.

The vertical distance between the inflection point of the closest optical axis on the object side of the second lens and the optical axis is represented by HIF211, the intersection of the image side of the second lens on the optical axis to the inflection point of the closest optical axis on the image side of the second lens and the optical axis The vertical distance between them is represented by HIF221, which satisfies the following conditions: HIF211=1.1264mm; HIF211/HOI=0.2253; HIF221=0mm; HIF221/HOI=0.

The third lens 130 has a negative refractive power and is made of plastic material. The object side surface 132 is concave, the image side surface 134 is convex, and both are aspherical, and both the object side surface 132 and the image side surface 134 have an inflection point. 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 entrance pupil diameter (HEP) is represented by ETP3. 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 inflection point of the closest optical axis on the object side of the third lens is represented by SGI311. The intersection of the image side of the third lens on the optical axis to The horizontal displacement distance parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the third lens is represented by SGI321, which satisfies the following conditions: SGI311=-0.3041mm; ∣SGI311∣/(∣SGI311∣+TP3)=0.4445 ; SGI321=-0.1172mm; ∣SGI321∣/(∣SGI321∣+TP3)=0.2357.

The vertical distance between the inflection point of the closest optical axis on the object side of the third lens and the optical axis is represented by HIF311. The vertical distance between them is represented by HIF321, which satisfies the following conditions: HIF311=1.5907mm; HIF311/HOI=0.3181; HIF321=1.3380mm; HIF321/HOI=0.2676.

The fourth lens 140 has a positive refractive power and is made of plastic material. The object side 142 is convex, the image side 144 is concave, and both are aspherical, and the object side 142 has two inflection points and the image side 144 has a Inflection point. The thickness of the fourth lens on the optical axis is TP4, and the thickness of the fourth lens at the height of 1/2 entrance pupil diameter (HEP) is represented by ETP4.

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 inflection point of the closest optical axis on the object side of the fourth lens is represented by SGI411. The intersection of the image side of the fourth lens on the optical axis to The horizontal displacement distance parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the fourth lens is represented by SGI421, which satisfies the following conditions: SGI411=0.0070mm; ∣SGI411∣/(∣SGI411∣+TP4)=0.0056; SGI421=0.0006mm; ∣SGI421∣/(∣SGI421∣+TP4)=0.0005.

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 is on the optical axis. The horizontal displacement distance parallel to the optical axis between the intersection point and the second inflection point close to the optical axis on the image side of the fourth lens is represented by SGI422, which satisfies the following conditions: SGI412=-0.2078mm; ∣SGI412∣/(∣SGI412∣+ TP4)=0.1439.

The vertical distance between the inflection point of the nearest optical axis on the object side of the fourth lens and the optical axis is represented by HIF411, the intersection of the fourth lens image side on the optical axis to the inverse inflection point and the optical axis of the nearest optical axis on the fourth lens image side The vertical distance between them is represented by HIF421, which satisfies the following conditions: HIF411=0.4706mm; HIF411/HOI=0.0941; HIF421=0.1721mm; HIF421/HOI=0.0344.

The vertical distance between the second inflection point on the object side of the fourth lens close to the optical axis and the optical axis is represented by HIF412. The vertical distance between the point and the optical axis is represented by HIF422, which satisfies the following conditions: HIF412=2.0421mm; HIF412/HOI=0.4084.

The fifth lens 150 has a positive refractive power and is made of plastic material, the object side 152 is convex, the image side 154 is convex, and both are aspherical, and the object side 152 has two inflection points and the image side 154 has a Inflection point. The thickness of the fifth lens on the optical axis is TP5, and the thickness of the fifth lens at the height of 1/2 entrance pupil diameter (HEP) is represented by ETP5.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the fifth lens on the optical axis and the inflection point of the closest optical axis on the object side of the fifth lens is represented by SGI511. The intersection of the image side of the fifth lens on the optical axis to The horizontal displacement distance parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the fifth lens is represented by SGI521, which satisfies the following conditions: SGI511=0.00364mm; ∣SGI511∣/(∣SGI511∣+TP5)=0.00338; SGI521=-0.63365mm; ∣SGI521∣/(∣SGI521∣+TP5)=0.37154.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the fifth lens on the optical axis and the second inflection point of the object side of the fifth lens close to the optical axis is represented by SGI512. The image side of the fifth lens is on the optical axis. The horizontal displacement distance parallel to the optical axis between the intersection point and the second inflection point on the image side of the fifth lens close to the optical axis is represented by SGI522, which satisfies the following conditions: SGI512=-0.32032mm; ∣SGI512∣/(∣SGI512∣+ TP5)=0.23009.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the fifth lens on the optical axis and the third inflection point on the object side of the fifth lens close to the optical axis is represented by SGI513. The image side of the fifth lens is on the optical axis. The horizontal displacement distance from the intersection to the third inflection point on the image side of the fifth lens that is parallel to the optical axis is represented by SGI523, which satisfies the following conditions: SGI513=0mm; ∣SGI513∣/(∣SGI513∣+TP5) =0; SGI523=0mm; ∣SGI523∣/(∣SGI523∣+TP5)=0.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the fifth lens on the optical axis and the fourth inflection point close to the optical axis on the object side of the fifth lens is represented by SGI514. The image side of the fifth lens is on the optical axis. The horizontal displacement distance between the intersection point and the fourth inflection point close to the optical axis on the image side of the fifth lens is represented by SGI524, which satisfies the following conditions: SGI514=0mm; ∣SGI514∣/(∣SGI514∣+TP5) =0; SGI524=0mm; ∣SGI524∣/(∣SGI524∣+TP5)=0.

The vertical distance between the inflection point of the nearest 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 nearest optical axis on the image side of the fifth lens and the optical axis is represented by HIF521, which satisfies the following conditions : HIF511=0.28212mm; HIF511/HOI=0.05642; HIF521=2.13850mm; HIF521/HOI=0.42770.

The vertical distance between the second inflection point close to the optical axis on the object side of the fifth lens and the optical axis is represented by HIF512, and the vertical distance between the second inflection point close to the optical axis on the image side of the fifth lens and the optical axis is represented by HIF522, It satisfies the following conditions: HIF512=2.51384mm; HIF512/HOI=0.50277.

The vertical distance between the third inflection point close to the optical axis on the object side of the fifth lens and the optical axis is represented by HIF513, and the vertical distance between the third inflection point close to the optical axis on the image side of the fifth lens and the optical axis is represented by HIF523, It satisfies the following conditions: HIF513=0mm; HIF513/HOI=0; HIF523=0mm; HIF523/HOI=0.

The vertical distance between the fourth inflection point close to the optical axis on the object side of the fifth lens and the optical axis is represented by HIF514, and the vertical distance between the fourth inflection point close to the optical axis on the image side of the fifth lens and the optical axis is represented by HIF524, It satisfies the following conditions: HIF514=0mm; HIF514/HOI=0; HIF524=0mm; HIF524/HOI=0.

The sixth lens 160 has negative refractive power and is made of plastic material. The object side 162 is concave, the image side 164 is concave, and the object side 162 has two inflection points and the image side 164 has one inflection point. In this way, the angle at which each field of view is incident on the sixth lens can be effectively adjusted 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 entrance pupil diameter (HEP) is represented by ETP6.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the sixth lens on the optical axis and the inflection point of the closest optical axis on the object side of the sixth lens is represented by SGI611. The intersection of the image side of the sixth lens on the optical axis to The horizontal displacement distance parallel to the optical axis between the inflection points of the nearest optical axis on the image side of the sixth lens is represented by SGI621, which satisfies the following conditions: SGI611=-0.38558mm; ∣SGI611∣/(∣SGI611∣+TP6)=0.27212 ; SGI621=0.12386mm; ∣SGI621∣/(∣SGI621∣+TP6)=0.10722.

The horizontal displacement distance parallel to the optical axis between the intersection of the object side of the sixth lens on the optical axis and the second inflection point of the object side of the sixth lens close to the optical axis is represented by SGI612. The image side of the sixth lens is on the optical axis. The horizontal displacement distance parallel to the optical axis between the intersection point and the second inflection point on the image side of the sixth lens close to the optical axis is represented by SGI621, which satisfies the following conditions: SGI612=-0.47400mm; ∣SGI612∣/(∣SGI612∣+ TP6)=0.31488; SGI622=0mm; ∣SGI622∣/(∣SGI622∣+TP6)=0.

The vertical distance between the inflection point of the nearest optical axis on the object side of the sixth lens and the optical axis is represented by HIF611, and the vertical distance between the inflection point of the nearest optical axis on the image side of the sixth lens and the optical axis is represented by HIF621, which satisfies the following conditions : HIF611=2.24283mm; HIF611/HOI=0.44857; HIF621=1.07376mm; HIF621/HOI=0.21475.

The vertical distance between the second inflection point close to the optical axis on the object side of the sixth lens and the optical axis is represented by HIF612, and the vertical distance between the second inflection point close to the optical axis on the image side of the sixth lens and the optical axis is represented by HIF622, It satisfies the following conditions: HIF612=2.48895mm; HIF612/HOI=0.49779.

The vertical distance between the third inflection point on the object side of the sixth lens close to the optical axis and the optical axis is represented by HIF613, and the vertical distance between the third inflection point on the image side of the sixth lens near the optical axis and the optical axis is represented by HIF623, It satisfies the following conditions: HIF613=0mm; HIF613/HOI=0; HIF623=0mm; HIF623/HOI=0.

The vertical distance between the fourth inflection point close to the optical axis on the object side of the sixth lens and the optical axis is represented by HIF614, and the vertical distance between the fourth inflection point close to the optical axis on the image side of the sixth lens and the optical axis is represented by HIF624, It satisfies the following conditions: HIF614=0mm; HIF614/HOI=0; HIF624=0mm; HIF624/HOI=0.

In this embodiment, the distance between the coordinate point on the object side of the first lens at 1/2HEP height and the infrared light imaging surface parallel to the optical axis is ETL, and the coordinate point on the object side of the first lens at 1/2HEP height to the The horizontal distance parallel to the optical axis between the coordinate points on the six-lens image side at 1/2HEP height is EIN, which satisfies the following conditions: ETL=19.304mm; EIN=15.733mm; EIN/ETL=0.815.

This embodiment satisfies the following conditions: ETP1=2.371mm; ETP2=2.134mm; ETP3=0.497mm; ETP4=1.111mm; ETP5=1.783mm; ETP6=1.404mm. The sum of the aforementioned ETP1 to ETP6 is SETP=9.300 mm. TP1=2.064mm; TP2=2.500mm; TP3=0.380mm; TP4=1.186mm; TP5=2.184mm; TP6=1.105mm; SETP/STP=0.987. SETP/EIN=0.5911.

This embodiment specifically controls the proportional relationship (ETP/TP) between the thickness (ETP) of each lens at 1/2 entrance pupil diameter (HEP) height and the thickness (TP) of the lens on the optical axis to which the surface belongs , to strike a balance between manufacturability and ability to correct aberrations, which satisfies the following conditions, ETP1/TP1=1.149; ETP2/TP2=0.854; ETP3/TP3=1.308; ETP4/TP4=0.936; ETP5/TP5=0.817; ETP6 /TP6=1.271.

In this embodiment, the horizontal distance of each adjacent two lenses at 1/2 entrance pupil diameter (HEP) height is controlled, so as to achieve a balance between the length of the optical imaging system HOS "miniature", the manufacturability and the ability to correct aberrations , especially control the proportional relationship (ED/IN) between the horizontal distance (ED) of the adjacent two lenses at 1/2 entrance pupil diameter (HEP) height and the horizontal distance (IN) of the adjacent two lenses on the optical axis ), which satisfies the following conditions, the horizontal distance parallel to the optical axis at 1/2 entrance pupil diameter (HEP) height between the first lens and the second lens is ED12=5.285mm; the distance between the second lens and the third lens is 1 The horizontal distance parallel to the optical axis at /2 entrance pupil diameter (HEP) height is ED23=0.283mm; the horizontal distance between the third lens and the fourth lens at 1/2 entrance pupil diameter (HEP) height parallel to the optical axis is ED34=0.330mm; the horizontal distance parallel to the optical axis at 1/2 entrance pupil diameter (HEP) height between the fourth lens and the fifth lens is ED45=0.348mm; the distance between the fifth lens and the sixth lens is 1/ 2 The horizontal distance parallel to the optical axis of the entrance pupil diameter (HEP) height is ED56=0.187mm. The sum of the aforementioned ED12 to ED56 is expressed in SED and SED=6.433 mm.

The horizontal distance between the first lens and the second lens on the optical axis is IN12=5.470mm, and ED12/IN12=0.966. The horizontal distance between the second lens and the third lens on the optical axis is IN23=0.178mm, and ED23/IN23=1.590. The horizontal distance between the third lens and the fourth lens on the optical axis is IN34=0.259mm, and ED34/IN34=1.273. The horizontal distance between the fourth lens and the fifth lens on the optical axis is IN45=0.209mm, and ED45/IN45=1.664. The horizontal distance between the fifth lens and the sixth lens on the optical axis is IN56=0.034mm, and ED56/IN56=5.557. The sum of the aforementioned IN12 to IN56 is expressed in SIN and SIN=6.150 mm. SED/SIN=1.046.

This implementation also meets the following conditions: ED12/ED23=18.685; ED23/ED34=0.857; ED34/ED45=0.947; ED45/ED56=1.859; IN12/IN23=30.746; IN23/IN34=0.686; IN34/IN45=1.239; IN45 /IN56=6.207.

The horizontal distance parallel to the optical axis between the coordinate point on the image side of the sixth lens at 1/2HEP height and the infrared light imaging surface is EBL=3.570mm, and the intersection of the sixth lens image side and the optical axis to the infrared light imaging The horizontal distance between the surfaces parallel to the optical axis is BL=4.032mm, and the embodiment of the present invention can satisfy the following formula: EBL/BL=0.8854. In this embodiment, the distance between the coordinate point on the image side of the sixth lens at 1/2HEP height and the infrared filter parallel to the optical axis is EIR=1.950mm, and the intersection point with the optical axis on the image side of the sixth lens to the infrared filter The distance between the light sheets parallel to the optical axis is PIR=2.121 mm, and satisfies the following formula: EIR/PIR=0.920.

The infrared filter 180 is made of glass, and is disposed between the sixth lens 160 and the infrared imaging surface 190 and does not affect 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 values are as follows: f=4.075mm; f/HEP = 1.4; and HAF = 50.000 degrees and tan(HAF) = 1.1918.

In the optical imaging system of this embodiment, the focal length of the first lens 110 is f1, and the focal length of the sixth lens 160 is f6, which satisfy the following conditions: f1=-7.828mm; ∣f/f1∣=0.52060; f6=-4.886 ; and ∣f1∣>∣f6∣.

In the optical imaging system of this embodiment, the focal lengths of the second lens 120 to the fifth lens 150 are f2, f3, f4, and f5, respectively, which satisfy the following conditions: ∣f2∣+∣f3∣+∣f4∣+∣f5∣ =95.50815mm; ∣f1∣+∣f6∣=12.71352mm and ∣f2∣+∣f3∣+∣f4∣+∣f5∣>∣f1∣+∣f6∣.

The ratio PPR of the focal length f of the optical imaging system to the focal length fp of each lens with positive refractive power, the ratio of the focal length f of the optical imaging system to the focal length fn of each lens with negative refractive power NPR, the optical imaging of this embodiment In the system, the sum of PPR of all lenses with positive refractive power is ΣPPR=f/f2+f/f4+f/f5=1.63290, and the sum of NPR of all lenses with negative refractive power is ΣNPR=∣f/f1∣+∣f/ f3∣+∣f/f6∣=1.51305, ΣPPR/∣ΣNPR∣=1.07921. At the same time, the following conditions are also met: ∣f/f2∣=0.69101; ∣f/f3∣=0.15834; ∣f/f4∣=0.06883; ∣f/f5∣=0.87305; ∣f/f6∣=0.83412.

In the optical imaging system of this embodiment, the distance from the object side 112 of the first lens to the image side 164 of the sixth lens is InTL, the distance from the object side 112 of the first lens to the infrared imaging surface 190 is HOS, the aperture 100 to the infrared The distance between the optical imaging surfaces 190 is InS, the half of the diagonal length of the effective sensing area of the image sensing element 192 is HOI, and the distance between the image side 164 of the sixth lens and the infrared imaging surface 190 is BFL, which satisfies the following conditions : InTL+BFL=HOS; HOS=19.54120mm; HOI=5.0mm; HOS/HOI=3.90824; HOS/f=4.7952; InS=11.685mm; and InS/HOS=0.59794.

In the optical imaging system of this embodiment, the sum of the thicknesses of all lenses with refractive power on the optical axis is ΣTP, which satisfies the following conditions: ΣTP=8.13899 mm; and ΣTP/InTL=0.52477. In this way, the contrast of system imaging and the yield of lens manufacturing can be taken into account at the same time, and an appropriate back focal length can be provided to accommodate other components.

In the optical imaging system of this embodiment, the radius of curvature of the object side 112 of the first lens is R1, and the radius of curvature of the image side 114 of the first lens is R2, which satisfy the following conditions: ∣R1/R2∣=8.99987. In this way, the first lens has an appropriate positive refractive power to prevent the spherical aberration from increasing too quickly.

In the optical imaging system of this embodiment, the radius of curvature of the object side surface 162 of the sixth lens is R11, and the radius of curvature of the image side surface 164 of the sixth lens is R12, which satisfy the following conditions: (R11-R12)/(R11+R12)= 1.27780. Thereby, it 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 ΣPP, which satisfies the following conditions: ΣPP=f2+f4+f5=69.770mm; and f5/(f2+f4+f5)=0.067 . Thereby, it is helpful to properly distribute the positive refractive power of a single lens to other positive lenses, so as to suppress the generation of significant aberrations in the traveling process of the incident light.

In the optical imaging system of this embodiment, the sum of the focal lengths of all lenses with negative refractive power is ΣNP, which satisfies the following conditions: ΣNP=f1+f3+f6=-38.451mm; and f6/(f1+f3+f6)= 0.127. Thereby, it is helpful to properly distribute the negative refractive power of the sixth lens to other negative lenses, so as to suppress the generation of significant aberrations in the traveling process of the 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=6.418mm; IN12/f=1.57491. Thereby, it helps to improve the chromatic aberration of the lens to improve its performance.

In the optical imaging system of this embodiment, the distance between the fifth lens 150 and the sixth lens 160 on the optical axis is IN56, which satisfies the following conditions: IN56=0.025mm; IN56/f=0.00613. Thereby, it 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 respectively TP1 and TP2, which satisfy the following conditions: TP1=1.934mm; TP2=2.486mm; and (TP1+IN12 )/TP2=3.36005. Thereby, it is helpful to control the sensitivity and improve the performance of the optical imaging system manufacturing.

In the optical imaging system of this embodiment, the thicknesses of the fifth lens 150 and the sixth lens 160 on the optical axis are TP5 and TP6 respectively, and the distance between the two lenses on the optical axis is IN56, which satisfies the following conditions: TP5= 1.072mm; TP6=1.031mm; and (TP6+IN56)/TP5=0.98555. Thereby, it helps to control the sensitivity of the optical imaging system manufacture and reduce the overall height of the system.

In the optical imaging system of this embodiment, the distance between the third lens 130 and the fourth lens 140 on the optical axis is IN34, and the distance between the fourth lens 140 and the fifth lens 150 on the optical axis is IN45, which satisfies the following Conditions: IN34=0.401mm; IN45=0.025mm; and TP4/(IN34+TP4+IN45)=0.74376. Thereby, it is helpful to slightly correct the aberration caused by the traveling process of the incident light layer by layer and reduce the overall height of the system.

In the optical imaging system of this embodiment, the horizontal displacement distance from the intersection of the object side surface 152 of the fifth lens on the optical axis to the position of the maximum effective radius of the object side surface 152 of the fifth lens on the optical axis is InRS51, and the image side surface 154 of the fifth lens is located at a distance of InRS51. The horizontal displacement distance from the intersection on the optical axis to the position of the maximum effective radius of the image side 154 of the fifth lens on the optical axis is InRS52, and the thickness of the fifth lens 150 on the optical axis is TP5, which satisfies the following conditions: InRS51=-0.34789mm ;InRS52=-0.88185mm; ∣InRS51∣/TP5=0.32458 and ∣InRS52∣/TP5=0.82276. Thereby, the manufacture and molding of the lens are facilitated, and the miniaturization of the lens is effectively maintained.

In the optical imaging system of the present embodiment, the vertical distance between the critical point of the object side surface 152 of the fifth lens and the optical axis is HVT51, and the vertical distance between the critical point and the optical axis of the fifth lens image side surface 154 is HVT52, which satisfies the following conditions: HVT51=0.515349mm; HVT52=0mm.

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 position of the maximum effective radius of the sixth lens object side 162 on the optical axis is InRS61, and the sixth lens image side 164 is in The horizontal displacement distance from the intersection on the optical axis to the position of the maximum effective radius of the image side 164 of the sixth lens on the optical axis is InRS62, and the thickness of the sixth lens 160 on the optical axis is TP6, which satisfies the following conditions: InRS61=-0.58390mm ; InRS62=0.41976mm; ∣InRS61∣/TP6=0.56616 and ∣InRS62∣/TP6=0.40700. Thereby, the manufacture and molding of the lens are facilitated, and the miniaturization of the lens is effectively maintained.

In the optical imaging system of the present embodiment, the vertical distance between the critical point and the optical axis of the object side surface 162 of the sixth lens is HVT61, and the vertical distance between the critical point and the optical axis of the sixth lens image side surface 164 is HVT62, which satisfies the following conditions: HVT61=0mm; HVT62=0mm.

In the optical imaging system of this embodiment, the following conditions are satisfied: HVT51/HOI=0.1031. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

In the optical imaging system of this embodiment, the following conditions are satisfied: HVT51/HOS=0.02634. Thereby, aberration correction of the peripheral field of view of the optical imaging system is facilitated.

In the optical imaging system of this embodiment, the third lens and the sixth lens have negative refractive power, the dispersion coefficient of the third lens is NA3, and the dispersion coefficient of the sixth lens is NA6, which satisfy the following conditions: NA6/NA3≤1. Thereby, the correction of the chromatic aberration of the optical imaging system is facilitated.

In the optical imaging system of this embodiment, the TV distortion of the optical imaging system during imaging is TDT, and the optical distortion during imaging is ODT, which satisfy the following conditions: TDT=2.124%; ODT=5.076%.

In the optical imaging system of this embodiment, the optical axis of visible light on the infrared light imaging surface, 0.3HOI and 0.7HOI at the spatial frequency of 55cycles/mm, the modulation conversion contrast transfer rate (MTF value) are respectively MTFE0, MTFE3 and MTFE7 means that it satisfies the following conditions: MTFE0 is about 0.84; MTFE3 is about 0.84; and MTFE7 is about 0.75. The optical axis of visible light on the infrared light imaging surface, 0.3HOI and 0.7HOI at the spatial frequency of 110cycles/mm, the modulation conversion contrast transfer rate (MTF value) are represented by MTFQ0, MTFQ3 and MTFQ7 respectively, which satisfy the following conditions: MTFQ0 is about is 0.66; MTFQ3 is about 0.65; and MTFQ7 is about 0.51. The optical axis, 0.3HOI and 0.7HOI on the infrared light imaging surface are represented by MTFH0, MTFH3 and MTFH7 respectively at the spatial frequency of 220cycles/mm and the modulation conversion contrast transfer rate (MTF value), which satisfies the following conditions: MTFH0 is approximately 0.17; about 0.07 for MTFH3; and about 0.14 for MTFH7.

In the optical imaging system of this embodiment, when the infrared operating wavelength of 850 nm is focused on the infrared light imaging surface, the optical axis, 0.3HOI and 0.7HOI of the image on the infrared light imaging surface are modulated at the spatial frequency (55cycles/mm) The conversion versus transfer ratios (MTF values) are expressed as MTFI0, MTFI3, and MTFI7, respectively, which satisfy the following conditions: MTFI0 is about 0.81; MTFI3 is about 0.8; and MTFI7 is about 0.15.

Please refer to Table 1 and Table 2 below.

Table 2. Aspheric coefficients of the first embodiment

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

Second Embodiment

Please refer to FIG. 4 , FIG. 5 and FIG. 6 , wherein FIG. 4 is a schematic diagram of an optical imaging system according to the second embodiment of the present invention, and FIG. 5 shows the optical imaging system of the second embodiment from left to right. Curves of spherical aberration, astigmatism and optical distortion. FIG. 6 is a characteristic diagram of infrared spectrum modulation and conversion of the present embodiment. It can be seen from FIG. 4 that the optical imaging system 20 includes an aperture 200, a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, a sixth lens 260, Infrared filter 280 , infrared light imaging surface 290 and image sensing component 292 .

The first lens 210 has a positive refractive power and is made of plastic material. The object side 212 is convex, the image side 214 is concave, and both are aspherical, and the object side 212 has an inflection point and the image side 214 has two Inflection point.

The second lens 220 has a positive refractive power and is made of plastic material, the object side 222 is concave, the image side 224 is convex, and both are aspherical, and the object side 232 has an inflection point and the image side 224 has two Inflection point.

The third lens 230 has a positive refractive power and is made of plastic material. The object side 232 is concave, the image side 234 is convex, and both are aspherical, and both the object side 232 and the image side 234 have two inflection points.

The fourth lens 240 has a negative refractive power and is made of plastic material. The object side 242 is convex, and the image side 244 is concave, both of which are aspherical, and both the object side 242 and the image side 244 have an inflection point.

The fifth lens 250 has a positive refractive power and is made of plastic material, the object side 252 is convex, the image side 254 is concave, and both are aspherical, and the object side 252 has an inflection point and the image side 254 has three Inflection point.

The sixth lens 260 has a negative refractive power and is made of plastic material. The object side surface 262 is convex, the image side surface 264 is concave, and both are aspherical. Inflection point. Thereby, it is beneficial to shorten the back focus to maintain the miniaturization. In addition, it can effectively suppress the incident angle of light in 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 between the sixth lens 260 and the infrared imaging surface 290 and does not affect the focal length of the optical imaging system.

Please refer to Table 3 and Table 4 below.

Table 4. Aspheric coefficients of the second embodiment

In the second embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not 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 values can be obtained:

Third Embodiment

Please refer to FIG. 7 , FIG. 8 and FIG. 9 , wherein FIG. 7 is a schematic diagram of an optical imaging system according to a third embodiment of the present invention, and FIG. 8 is from left to right of the optical imaging system of the third embodiment. Curves of spherical aberration, astigmatism and optical distortion. FIG. 9 is a characteristic diagram of infrared spectrum modulation and conversion of the present embodiment. As can be seen from FIG. 7 , the optical imaging system 30 sequentially includes a first lens 310 , a second lens 320 , an aperture 300 , a third lens 330 , a fourth lens 340 , a fifth lens 350 , a sixth lens 360 , Infrared filter 380 , infrared light imaging surface 390 and image sensing component 392 .

The first lens 310 has a positive refractive power and is made of plastic material. The object side 312 is concave, the image side 314 is convex, and both are aspherical, and both the object side 312 and the image side 314 have an inflection point.

The second lens 320 has a negative refractive power and is made of plastic material. The object side 322 is concave, the image side 324 is convex, and both are aspherical, and both the object side 322 and the image side 324 have an inflection point.

The third lens 330 has a negative refractive power and is made of plastic material. The object side 332 is concave, the image side 334 is concave, and both are aspherical, and the object side 332 has an inflection point and the image side 334 has three Inflection point.

The fourth lens 340 has a positive refractive power and is made of plastic material. The object side surface 342 is convex, the image side surface 344 is concave, and both are aspherical, and both the object side surface 342 and the image side surface 344 have an inflection point.

The fifth lens 350 has a positive refractive power and is made of plastic material. The object side surface 352 is convex, the image side surface 354 is convex, and both are aspherical, and both the object side surface 352 and the image side surface 354 have two inflection points.

The sixth lens 360 has a negative refractive power and is made of plastic material, the object side 362 is concave, the image side 364 is concave, and both are aspherical, and the object side 362 has two inflection points and the image side 364 has a Inflection point. Thereby, it is beneficial to shorten the back focus to maintain the miniaturization. In addition, it can effectively suppress the incident angle of light in 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 sixth lens 360 and the infrared imaging surface 390 and does not affect the focal length of the optical imaging system.

Please refer to Table 5 and Table 6 below.

Table 6. Aspheric coefficients of the third embodiment

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

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

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

Fourth Embodiment

Please refer to FIG. 10 , FIG. 11 and FIG. 12 , wherein FIG. 10 is a schematic diagram of an optical imaging system according to a fourth embodiment of the present invention, and FIG. 11 is from left to right of the optical imaging system of the fourth embodiment. Curves of spherical aberration, astigmatism and optical distortion. FIG. 12 is a characteristic diagram of infrared spectrum modulation and conversion of the present embodiment. It can be seen from FIG. 10 that the optical imaging system 40 includes a first lens 410, an aperture 400, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, a sixth lens 460, Infrared filter 480 , infrared light imaging surface 490 and image sensing component 492 .

The first lens 410 has a negative refractive power and is made of plastic material. The object side surface 412 is concave, the image side surface 414 is convex, and both are aspherical, and both the object side surface 412 and the image side surface 414 have an inflection point.

The second lens 420 has a positive refractive power and is made of plastic material. The object side surface 422 is convex, the image side surface 424 is convex, and both are aspherical, and the object side surface 422 has an inflection point.

The third lens 430 has negative refractive power and is made of plastic material. The object side surface 432 is concave, the image side surface 434 is convex, and both are aspherical, and the object side surface 432 has two inflection points.

The fourth lens 440 has a positive refractive power and is made of plastic material. The object side 442 is convex, and the image side 444 is concave, both of which are aspherical, and both the object side 442 and the image side 444 have an inflection point.

The fifth lens 450 has a positive refractive power and is made of plastic material. The object side surface 452 is convex, the image side surface 454 is convex, and both are aspherical, and both the object side surface 452 and the image side surface 454 have an inflection point.

The sixth lens 460 has a negative refractive power and is made of plastic material, its object side 462 is convex, its image side 464 is concave, and both are aspherical, and its object side 462 has an inflection point and its image side 464 has two Inflection point. Thereby, it is beneficial to shorten the back focus to maintain the miniaturization. In addition, it can effectively suppress the incident angle of light in 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, which is disposed between the sixth lens 460 and the infrared imaging surface 490 and does not affect the focal length of the optical imaging system.

Please refer to Table 7 and Table 8 below.

Table 8. Aspheric coefficients of the fourth embodiment

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

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

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

Fifth Embodiment

Please refer to FIG. 13 , FIG. 14 and FIG. 15 , wherein FIG. 13 is a schematic diagram of an optical imaging system according to a fifth embodiment of the present invention, and FIG. 14 is from left to right of the optical imaging system of the fifth embodiment. Curves of spherical aberration, astigmatism and optical distortion. FIG. 15 is a characteristic diagram of infrared spectrum modulation and conversion of the present embodiment. As can be seen from FIG. 13 , the optical imaging system 50 sequentially includes a first lens 510 , an aperture 500 , a second lens 520 , a third lens 530 , a fourth lens 540 , a fifth lens 550 , a sixth lens 560 , Infrared filter 580 , infrared light imaging surface 590 and image sensing component 592 .

The first lens 510 has a negative refractive power and is made of plastic material. The object side 512 is convex, the image side 514 is concave, and both are aspherical, and both the object side 512 and the image side 514 have an inflection point.

The second lens 520 has a negative refractive power and is made of plastic material. The object side 522 is concave, the image side 524 is convex, and both are aspherical, and the object side 522 has an inflection point.

The third lens 530 has a positive refractive power and is made of plastic material. The object side surface 532 is convex, the image side surface 534 is concave, and both are aspherical, and the object side surface 522 has two inflection points.

The fourth lens 540 has a negative refractive power and is made of plastic material. The object side surface 542 is convex and the image side surface 544 is concave, both of which are aspherical, and the object side surface 542 has two inflection points.

The fifth lens 550 has a positive refractive power and is made of plastic material. The object side 552 is convex, the image side 554 is convex, and both are aspherical, and both the object side 552 and the image side 554 have an inflection point.

The sixth lens 560 has a negative refractive power and is made of plastic material, its object side 562 is concave, its image side 564 is convex, and both are aspherical, and its object side 562 has an inflection point and its image side 564 has two Inflection point. Thereby, it is beneficial to shorten the back focus to maintain the miniaturization. In addition, it can effectively suppress the incident angle of light in the off-axis field of view, and correct the aberration of the off-axis field of view.

The infrared filter 580 is made of glass, and is disposed between the sixth lens 560 and the infrared imaging surface 590 and does not affect the focal length of the optical imaging system.

Please refer to Table 9 and Table 10 below.

Table 10. Aspheric coefficients of the fifth embodiment

In the fifth embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not 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. 16 , FIG. 17 and FIG. 18 , wherein FIG. 16 is a schematic diagram of an optical imaging system according to the sixth embodiment of the present invention, and FIG. 17 is from left to right of the optical imaging system of the sixth embodiment. Curves of spherical aberration, astigmatism and optical distortion. FIG. 18 is a characteristic diagram of infrared spectrum modulation conversion of this embodiment. It can be seen from FIG. 16 that the optical imaging system 60 includes a first lens 610, a second lens 620, an aperture 600, a third lens 630, a fourth lens 640, a fifth lens 650, a sixth lens 660, Infrared filter 680 , infrared light imaging surface 690 and image sensing component 692 .

The first lens 610 has a negative refractive power and is made of plastic material. The object side 612 is concave, the image side 614 is convex, and both are aspherical, and both the object side 612 and the image side 614 have an inflection point.

The second lens 620 has a positive refractive power and is made of plastic material, the object side 622 is convex, the image side 624 is convex, and both are aspherical, and the object side 622 has two inflection points and the image side 624 has a Inflection point.

The third lens 630 has a negative refractive power and is made of plastic material. The object side surface 632 is concave, the image side surface 634 is convex, and both are aspherical, and the object side surface 632 has an inflection point.

The fourth lens 640 has a positive refractive power and is made of plastic material. The object side 642 is convex, and the image side 644 is concave, both of which are aspherical, and both the object side 642 and the image side 644 have an inflection point.

The fifth lens 650 has a positive refractive power and is made of plastic material. The object side 652 is convex, the image side 654 is convex, and both are aspherical, and the object side 652 has three inflection points and the image side 654 has a Inflection point.

The sixth lens 660 has a negative refractive power and is made of plastic material. Its object side 662 is convex, its image side 664 is concave, and both are aspherical, and its object side 662 has two inflection points and its image side 664 has a Inflection point. In this way, it is beneficial to shorten the back focal length to maintain the miniaturization, and can also effectively suppress the incident angle of the light in 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 sixth lens 660 and the infrared imaging surface 690 and does not affect the focal length of the optical imaging system.

Please refer to Table 11 and Table 12 below.

Table 12. Aspheric coefficients of the sixth embodiment

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

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

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

Although the present utility model has been disclosed as above in the embodiments, it is not intended to limit the present utility model. Anyone who is familiar with this technique can make various changes and modifications without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model shall be determined by those defined by the claims.

Although the present invention has been particularly shown and described with reference to its exemplary embodiments, it will be understood by those skilled in the art that the present invention is not deviated from the spirit and scope of the present invention as defined by the claims and their equivalents Various changes in form and detail may be made hereunder.

Claims (25)

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

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power;

a fifth lens element with refractive power;

a sixth lens element with refractive power; and

an infrared light imaging plane;

wherein the optical imaging system has six lenses with refractive power, at least one of the first lens element to the sixth lens element has positive refractive power, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, the exit pupil diameter of the image-side surface of the sixth lens element is HXP, half of the maximum viewing angle of the optical imaging system is HAF, the first lens element to the sixth lens element have a height of 1/2HXP and thicknesses parallel to the optical axis of 539p 1, ETP 7, ETP3, ETP4, ETP5 and ETP6, the sum of the ETP1 to ETP6 is SETP, the sum of the thicknesses of the first lens element to the sixth lens element have thicknesses of 1, 2,3, TP4, TP5 and TP6, the sum of the TP 8985 to TP6 satisfies the following conditions: f/HEP is more than or equal to 0.5 and less than or equal to 1.8; 0deg < HAF <50 deg and 0.2 < SETP/STP < 1.

2. The optical imaging system of claim 1, wherein the infrared light has a wavelength between 700nm and 1300nm and the first spatial frequency is represented by SP1, satisfying the following condition: SP1 is less than or equal to 440 cycles/mm.

3. The optical imaging system of claim 1, wherein the infrared light has a wavelength of 850nm to 960nm and the first spatial frequency is represented by SP1, satisfying the following condition: SP1 is less than or equal to 220 cycles/mm.

4. The optical imaging system of claim 3, wherein the horizontal distance parallel to the optical axis between the coordinate point on the object-side surface of the first lens element at a height of 1/2HEP and the infrared light image plane is ETL, and the horizontal distance parallel to the optical axis between the coordinate point on the object-side surface of the first lens element at a height of 1/2HEP and the coordinate point on the image-side surface of the sixth lens element at a height of 1/2HEP is EIN, wherein the following conditions are satisfied: EIN/ETL is more than or equal to 0.2 and less than 1.

5. The optical imaging system of claim 1, wherein the horizontal distance from a coordinate point on the object-side surface of the first lens element at a HEP height of 1/2 to a coordinate point on the image-side surface of the sixth lens element at a HEP height of 1/2, parallel to the optical axis, is EIN, which satisfies the following equation: SETP/EIN is more than or equal to 0.2 and less than 1.

6. The optical imaging system of claim 1, wherein an axial distance between the first lens and the second lens is IN12, and an axial distance between the third lens and the fourth lens is IN34, wherein the following conditions are satisfied: IN12> IN 34.

7. The optical imaging system of claim 1, wherein an axial distance between the fourth lens element and the fifth lens element is IN45, and an axial distance between the fifth lens element and the sixth lens element is IN56, which satisfies the following conditions: IN56> IN 45.

8. The optical imaging system of claim 1, wherein an axial distance between the third lens and the fourth lens is IN34, and an axial distance between the fourth lens and the fifth lens is IN45, which satisfies the following conditions: IN45> IN 34.

9. The optical imaging system of claim 1, further comprising an aperture stop, wherein a distance InS is provided on an optical axis from the aperture stop to the infrared light image plane, and a distance HOS is provided on an optical axis from the object side surface of the first lens element to the infrared light image plane, wherein the following formula is satisfied: 0.2-1.1 of InS/HOS.

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

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power;

a fifth lens element with refractive power;

a sixth lens element with refractive power; and

an infrared light imaging plane;

wherein the optical imaging system has six lens elements with refractive power, at least one surface of at least one lens element from the first lens element to the sixth lens element has at least one inflection point, at least one lens element from the first lens element to the sixth lens element has positive refractive power, the focal length of the optical imaging system is f, the entrance pupil diameter of the optical imaging system is HEP, the exit pupil diameter of the image side surface of the sixth lens element is HXP, half of the maximum visible angle of the optical imaging system is HAF, the horizontal distance from the coordinate point of the height of 1/2HXP on the object side surface of the first lens element to the infrared light imaging surface in parallel to the optical axis is ETL, the horizontal distance from the coordinate point of the height of 1/2HXP on the object side surface of the first lens element to the coordinate point of the height of 1/2HXP on the image side surface of the sixth lens element in parallel to the optical axis is EIN, it satisfies the following conditions: f/HEP is more than or equal to 0.5 and less than or equal to 1.5; 0deg < HAF <50 deg and 0.2 < EIN/ETL < 1.

11. The optical imaging system of claim 10, wherein the optical imaging system has a maximum imaging height HOI perpendicular to the optical axis on the infrared light imaging plane, and the optical axis, 0.3HOI and 0.7HOI of the infrared light on the infrared light imaging plane have modulation conversion contrast transfer rates at a spatial frequency of 110cycles/mm, respectively expressed as MTFQ0, MTFQ3 and MTFQ7, which satisfy the following conditions: MTFQ0 is more than or equal to 0.01; MTFQ3 is more than or equal to 0.01; and MTFQ7 is more than or equal to 0.01.

12. The optical imaging system of claim 10, wherein the optical imaging system has a maximum imaging height HOI perpendicular to the optical axis on the infrared imaging plane, and the distance HOS from the object-side surface of the first lens element to the infrared imaging plane on the optical axis satisfies the following condition: HOS/HOI is more than or equal to 0.5 and less than or equal to 6.

13. The optical imaging system of claim 10, further comprising an aperture, the aperture positioned in front of the image side surface of the third lens element.

14. The optical imaging system of claim 10, wherein the image-side surface of the second lens element is convex along the optical axis.

15. The optical imaging system of claim 10, wherein the object-side surface of the fifth lens element is convex on the optical axis.

16. The optical imaging system of claim 10, wherein the fourth lens element has a convex object-side surface and a convex image-side surface.

17. The optical imaging system of claim 10, wherein the image-side surface of the fourth lens element is convex along the optical axis.

18. The optical imaging system of claim 10, wherein all of the first through sixth lenses are plastic.

19. The optical imaging system of claim 10, characterized in that it satisfies the following condition: f/HEP is more than or equal to 0.5 and less than or equal to 1.4.

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

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power;

a fifth lens element with refractive power;

a sixth lens element with refractive power; and

an infrared light imaging plane;

wherein the optical imaging system has six lenses with refractive power, at least one surface of each of at least two lenses of the first lens to the fifth lens has at least one inflection point, a focal length of the optical imaging system is f, an entrance pupil diameter of the optical imaging system is HEP, an image side exit pupil diameter of the sixth lens is HXP, a half of a maximum angle of view of the optical imaging system is HAF, thicknesses of the first lens to the sixth lens in 1/2HEP height and parallel to an optical axis are ETP1, ETP2, ETP3, ETP4, ETP5 and ETP6, respectively, a sum of the ETP1 to ETP6 is SETP, thicknesses of the first lens to the sixth lens in the optical axis are 1, TP2, TP3, TP 36, TP5 and TP6, a sum of the TP 398938 and a total sum of the TP 398938 satisfies the following conditions: f/HEP is more than or equal to 0.5 and less than or equal to 1.3; 0deg < HAF ≤ 45 deg; and 0.2 is less than or equal to SETP/STP < 1.

21. The optical imaging system of claim 20, wherein the first lens element has a distance HOS from the object-side surface to the infrared imaging surface on the optical axis, and wherein the optical imaging system satisfies the following equation: HOS is more than 0mm and less than or equal to 20 mm.

22. The optical imaging system of claim 20, wherein the infrared light has a wavelength of 850nm to 960nm and the first spatial frequency is represented by SP1, satisfying the following condition: SP1 is less than or equal to 220 cycles/mm.

23. The optical imaging system of claim 20, wherein the first lens element to the fifth lens element are all made of plastic.

24. The optical imaging system of claim 20, wherein an axial distance between the first lens element and the second lens element is IN12, an axial distance between the second lens element and the third lens element is IN23, an axial distance between the third lens element and the fourth lens element is IN34, an axial distance between the fourth lens element and the fifth lens element is IN45, and an axial distance between the fifth lens element and the sixth lens element is IN56, wherein the following conditions are satisfied: IN12> IN 34; IN45> IN 34; and IN56> IN 45.

25. The optical imaging system of claim 20, further comprising an aperture stop and an image sensor disposed behind the infrared imaging plane and having at least 10 ten thousand pixels, wherein a distance InS is provided on an optical axis from the aperture stop to the infrared imaging plane, and a distance HOS is provided on an optical axis from the object side surface of the first lens element to the infrared imaging plane, wherein the following formula is satisfied: 0.2-1.1 of InS/HOS.

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