CN115542516A - Fixed focus lens - Google Patents

Fixed focus lens Download PDF

Info

Publication number
CN115542516A
CN115542516A CN202211145666.7A CN202211145666A CN115542516A CN 115542516 A CN115542516 A CN 115542516A CN 202211145666 A CN202211145666 A CN 202211145666A CN 115542516 A CN115542516 A CN 115542516A
Authority
CN
China
Prior art keywords
lens
equal
fixed
focus
focal power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211145666.7A
Other languages
Chinese (zh)
Inventor
翟林燕
梁伟朝
应永茂
张圆
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sunny Optics Zhongshan Co Ltd
Original Assignee
Sunny Optics Zhongshan Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sunny Optics Zhongshan Co Ltd filed Critical Sunny Optics Zhongshan Co Ltd
Priority to CN202211145666.7A priority Critical patent/CN115542516A/en
Publication of CN115542516A publication Critical patent/CN115542516A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
    • G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
    • G02B13/0045—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having five or more lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0055—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element
    • G02B13/006—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element at least one element being a compound optical element, e.g. cemented elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/008—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras designed for infrared light
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/14—Optical objectives specially designed for the purposes specified below for use with infrared or ultraviolet radiation

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Lenses (AREA)

Abstract

The invention relates to a fixed focus lens, which comprises the following components in sequence along the direction from an object side to an image side along an optical axis: the optical lens comprises a first lens (L1) with negative focal power, a second lens (L2) with positive focal power, a third lens (L3) with positive focal power, a diaphragm (STO), a fourth lens (L4) with positive focal power, a fifth lens (L5) with negative focal power, a sixth lens (L6) with positive focal power, a seventh lens (L7) with positive focal power and an eighth lens (L8) with negative focal power, wherein the shape of the object side surface of the fifth lens (L5) is concave, the sixth lens (L6) is a convex lens, and the eighth lens (L8) is a paraxial region concave-convex lens. The fixed-focus lens has the characteristics of large target surface, ultra-large aperture, large light flux, low cost, miniaturization and high imaging performance, and can clearly image within the temperature range of-40 ℃ to +80 ℃.

Description

Fixed focus lens
Technical Field
The invention relates to the technical field of optical lenses, in particular to a fixed-focus lens.
Background
With the rapid development of work in the fields of security and public security, the demand for monitoring fixed focus lenses is also gradually rising. In order to have higher light transmission quantity at night, the ultra-large aperture lens better meets the market demand, so that the research and development design of the ultra-large aperture lens is necessary. However, most of the lenses in the lens market firstly ensure the imaging quality in the daytime, and the imaging quality at night is obviously reduced in the practical aperture. Therefore, aiming at the defects of the prior art, the ultra-large aperture security lens which has a large target surface, is low in cost and does not have virtual focus within the temperature range of-40 ℃ to 80 ℃ is needed.
Disclosure of Invention
The invention aims to provide a fixed-focus lens with an ultra-large aperture, which has a large target surface, is low in cost and does not have virtual focus within the temperature range of-40-80 ℃.
To achieve the above object, the present invention provides a fixed focus lens, sequentially including, in a direction from an object side to an image side along an optical axis: the negative power lens comprises a first lens with negative power, a second lens with positive power, a third lens with positive power, a diaphragm, a fourth lens with positive power, a fifth lens with negative power, a sixth lens with positive power, a seventh lens with positive power and an eighth lens with negative power.
According to an aspect of the present invention, in a direction from an object side to an image side along an optical axis,
the first lens is a paraxial region convex-concave lens;
the second lens is a concave-convex lens;
the paraxial region of the object side surface of the third lens is convex;
the shape of the image side surface of the fourth lens is convex;
the object side surface of the fifth lens is concave;
the sixth lens is a convex lens;
the seventh lens is a convex lens;
the eighth lens is a paraxial region meniscus lens.
According to an aspect of the present invention, the first lens, the second lens, the third lens, the seventh lens, and the eighth lens are aspherical lenses;
the fourth lens, the fifth lens and the sixth lens are spherical lenses.
According to an aspect of the present invention, the first lens, the second lens, the third lens, the seventh lens, and the eighth lens are plastic lenses;
the fourth lens, the fifth lens and the sixth lens are glass lenses.
According to an aspect of the present invention, the fourth lens and the fifth lens are cemented to form a cemented lens group.
According to an aspect of the present invention, a focal length F45 of the cemented lens group and an effective focal length F of the prime lens satisfy: F45/F is more than or equal to-4.0 and less than or equal to 16.5.
According to an aspect of the present invention, the focal length F45 of the cemented lens group and the back group focal length FB of the fixed-focus lens satisfy: F45/FB of-2.2 is less than or equal to 10.5.
According to one aspect of the invention, the total optical length TTL of the fixed-focus lens and the back focal length BFL of the fixed-focus lens satisfy: TTL/BFL is more than or equal to 5.8 and less than or equal to 8.0.
According to one aspect of the invention, the effective focal length F of the fixed-focus lens and the back focal length BFL of the fixed-focus lens satisfy: F/BFL is more than or equal to 1.0 and less than or equal to 1.5.
According to an aspect of the present invention, the effective focal length F of the fixed-focus lens and the maximum image height IH of the fixed-focus lens satisfy: F/IH is more than or equal to 0.4 and less than or equal to 0.8.
According to an aspect of the present invention, a focal length F1 of the first lens and an effective focal length F of the prime lens satisfy: F1/F is more than or equal to minus 2.2 and less than or equal to minus 1.6.
According to an aspect of the present invention, a center distance D12 on an optical axis from the first lens to the second lens and a total optical length TTL of the prime lens satisfy: D12/TTL is more than or equal to 0.1 and less than or equal to 0.3.
According to an aspect of the present invention, the refractive index Nd3 and the abbe number Vd3 of the third lens respectively satisfy: nd3 is more than or equal to 1.6 and less than or equal to 1.7; vd3 is more than or equal to 20 and less than or equal to 30.
According to an aspect of the present invention, the refractive index Nd4 and the abbe number Vd4 of the fourth lens respectively satisfy: nd4 is more than or equal to 1.70 and less than or equal to 1.8; vd4 is more than or equal to 50 and less than or equal to 60;
the refractive index Nd5 and the Abbe number Vd5 of the fifth lens respectively satisfy the following conditions: nd5 is more than or equal to 1.70 and less than or equal to 1.9; vd5 is more than or equal to 20 and less than or equal to 30.
According to an aspect of the present invention, the refractive index Nd6 and the abbe number Vd6 of the sixth lens respectively satisfy: nd6 is more than or equal to 1.40 and less than or equal to 1.5; vd6 is more than or equal to 90 and less than or equal to 95.
According to an aspect of the present invention, a focal length F6 of the sixth lens and an effective focal length F of the prime lens satisfy: F6/F is more than or equal to 2.6 and less than or equal to 4.5.
According to an aspect of the invention, the edge thickness ET8 of the eighth lens and the center thickness CT8 of the eighth lens satisfy: ET8/CT8 is more than or equal to 1.6 and less than or equal to 2.6.
According to an aspect of the present invention, a focal length F8 of the eighth lens and an effective focal length F of the prime lens satisfy: F8/F is less than or equal to-2.6 and is less than or equal to-5.6.
According to one aspect of the present invention, the prime lens further includes an optical filter,
the optical effective aperture SDF of the optical filter and the optical effective semi-aperture SD1 of the first lens meet the following requirements: SDF/SD1 is more than or equal to 0.6 and less than or equal to 0.9.
According to an aspect of the invention, the optical effective diameter SDS of the diaphragm and the optical effective half-aperture SD1 of the first lens satisfy: SDS/SD1 is more than or equal to 0.5 and less than or equal to 0.9.
According to the scheme of the invention, the arrangement mode of eight lenses is adopted, and the focal power, different shapes, specific materials, focal length relation and various parameter indexes of the lens are optimally configured and matched, so that the fixed-focus lens has high-quality imaging performance, can clearly image within the temperature range of-40 ℃ to +80 ℃, has large target surface, super-large aperture, large light transmission amount, low cost and miniaturization, and is particularly suitable for 1/1.8' large target surface chips. Moreover, through the design of the two-gear type variable diaphragm, the fixed-focus lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic structural diagram of a fixed-focus lens according to a first embodiment of the present invention;
fig. 2 is a schematic view of a light fan of a fixed focus lens according to a first embodiment of the invention;
fig. 3 is a schematic structural diagram of a fixed-focus lens according to a second embodiment of the present invention;
fig. 4 is a schematic view of a light fan of a fixed-focus lens according to a second embodiment of the present invention;
fig. 5 is a schematic structural diagram of a fixed-focus lens according to a third embodiment of the present invention;
fig. 6 is a schematic view of a light fan of a fixed-focus lens according to a third embodiment of the present invention;
fig. 7 is a schematic structural diagram of a fixed-focus lens according to a fourth embodiment of the present invention;
fig. 8 schematically shows a light fan diagram of a fixed-focus lens according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
The embodiments described in this specification are to be considered in all respects as illustrative and not restrictive, and the appended drawings are intended to be part of the entire specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and simplified or conveniently indicated. Further, the components of the structures in the drawings are described separately, and it should be noted that the components not shown or described in the drawings are well known to those skilled in the art.
Any reference to directions and orientations to the description of the embodiments herein is merely for convenience of description and should not be construed as limiting the scope of the invention in any way. The following description of the preferred embodiments refers to combinations of features which may be present independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.
As shown in fig. 1, the present invention provides a fixed focus lens, sequentially including, along an optical axis from an object side to an image side: a first lens L1, a second lens L2, a third lens L3, a stop STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8. Among them, the first lens L1, the fifth lens L5, and the eighth lens L8 are all negative power lenses, and the second lens L2, the third lens L3, the fourth lens L4, the sixth lens L6, and the seventh lens L7 are all positive power lenses.
In the direction from the object side to the image side along the optical axis, the first lens L1 is a paraxial region convex-concave lens, the second lens L2 is a concave-convex lens, the paraxial region of the object-side surface of the third lens L3 is convex, the image-side surface of the fourth lens L4 is convex, the object-side surface of the fifth lens L5 is concave, both the sixth lens L6 and the seventh lens L7 are convex-convex lenses, and the eighth lens L8 is a paraxial region convex-concave lens.
According to the technical scheme, the eight lenses in the arrangement mode are adopted, the focal power, the object side and the image side of each lens are optimally configured to be different in shape, so that the prime lens has high-quality imaging performance, can clearly image within the temperature range of minus 40 ℃ to plus 80 ℃, realizes large target surface and ultra-large aperture, and can be suitable for a large target surface chip of 1/1.8'. Moreover, through the design of the two-gear type variable diaphragm STO, the fixed-focus lens can support two gears F1.0/F1.6 under visible light, and under the gear F1.6, the lens can realize the day and night confocal function.
In the embodiment of the present invention, the first lens L1, the second lens L2, the third lens L3, the seventh lens L7, and the eighth lens L8 are all aspheric lenses, and the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all spherical lenses. By adopting the aspheric lens and the combination thereof, the aberration of the fixed-focus lens optical system can be efficiently adjusted, and the performance of the lens is further improved.
In the embodiment of the present invention, the first lens L1, the second lens L2, the third lens L3, the seventh lens L7, and the eighth lens L8 are all plastic lenses, and the fourth lens L4, the fifth lens L5, and the sixth lens L6 are all glass lenses. Through the optimized mixed arrangement of the lens glass and the plastic material, the unstable correction of high and low temperature imaging and the compensation of temperature drift can be realized, so that the cost of the lens is reduced, and the cost of the lens is reduced.
In the embodiment of the present invention, the fourth lens element L4 and the fifth lens element L5 are cemented together to form a cemented lens group. The cemented lens can correct the external aberrations such as field curvature, coma aberration and astigmatism, and further improve the imaging performance of the lens. Preferably, the focal length F45 of the cemented lens group and the effective focal length F of the prime lens satisfy: F45/F is more than or equal to-4.0 and less than or equal to 16.5. Preferably, in the cemented lens group, the refractive index Nd4 and the abbe number Vd4 of the fourth lens L4 satisfy the following conditional expressions, respectively: nd4 is more than or equal to 1.70 and less than or equal to 1.8; vd4 is more than or equal to 50 and less than or equal to 60. The refractive index Nd5 and the abbe number Vd5 of the fifth lens L5 satisfy the following conditional expressions, respectively: nd5 is more than or equal to 1.70 and less than or equal to 1.9; vd5 is more than or equal to 20 and less than or equal to 30. Thus, by arranging the cemented doublet reasonably, and designing the refractive index and the abbe number of the fourth lens L4 and the fifth lens L5, the aberration in the lens optical system can be effectively reduced.
Preferably, the focal length F45 of the cemented mirror group and the back group focal length FB of the fixed focus lens satisfy: F45/FB of-2.2 is less than or equal to 10.5. The back group focal length FB here refers to a combined focal length of the fourth lens L4 to the eighth lens L8 from the object side to the image side. By designing the focal length ratio of the cemented lens group and the rear lens group, the aberration of incident light entering the optical system can be balanced.
In the embodiment of the invention, the total optical length TTL of the fixed-focus lens, the effective focal length F of the fixed-focus lens and the back focal length BFL of the fixed-focus lens respectively satisfy the following conditional expressions: TTL/BFL is more than or equal to 5.8 and less than or equal to 8.0; F/BFL is more than or equal to 1.0 and less than or equal to 1.5. By reasonably and optimally designing the parameter indexes of the total optical length, the focal length and the back focal length of the lens, the miniaturization can be realized, and the performance requirement of small volume can be met. It should be noted that the back focal length BFL of the fixed-focus lens in the embodiment of the present invention refers to a distance from the image side of the last lens, i.e., the eighth lens L8, to the image plane IMA.
In the embodiment of the invention, the effective focal length F of the fixed-focus lens and the maximum image height IH of the fixed-focus lens meet the following requirements: F/IH is more than or equal to 0.4 and less than or equal to 0.8, which is beneficial to improving the resolving power of the fixed-focus lens and reducing the sensitivity of the lens.
In the embodiment of the present invention, the focal length F1 of the first lens L1 and the effective focal length F of the fixed-focus lens satisfy: F1/F is more than or equal to-2.2 and less than or equal to-1.6, so that light can correctly and stably enter the rear optical structure of the lens, the light flux is increased, and the resolution performance is improved.
In the embodiment of the present invention, the central distance D12 between the first lens L1 and the second lens L2 on the optical axis and the total optical length TTL of the fixed-focus lens satisfy: D12/TTL is more than or equal to 0.1 and less than or equal to 0.3, and the deflection angle of light emergent from the image side surface of the first lens L1 can be effectively controlled, so that the main light angle CRA of the lens can be effectively controlled.
In the embodiment of the invention, the refractive index Nd3 and the abbe number Vd3 of the third lens L3 respectively satisfy the following conditional expressions: nd3 is more than or equal to 1.6 and less than or equal to 1.7; vd3 is more than or equal to 20 and less than or equal to 30. Through carrying out this setting to the refracting index and the dispersion coefficient of plastic lens, can enough reduce cost, be favorable to promoting the resolution quality under the lens high low temperature state again.
In the embodiment of the present invention, the refractive index Nd6 and the abbe number Vd6 of the sixth lens L6 respectively satisfy the following conditional expressions: nd6 is more than or equal to 1.40 and less than or equal to 1.5; vd6 is more than or equal to 90 and less than or equal to 95. The focal length F6 of the sixth lens L6 and the effective focal length F of the fixed-focus lens meet the following conditions: F6/F is more than or equal to 2.6 and less than or equal to 4.5. By satisfying the two conditional expressions, the confocal state of the lens in the visible light and infrared states can be balanced.
In the embodiment of the present invention, the edge thickness ET8 of the eighth lens L8 and the center thickness CT8 of the eighth lens L8 satisfy: ET8/CT8 is more than or equal to 1.6 and less than or equal to 2.6. Through carrying out reasonable setting to eighth lens L8's thickness index, can reduce the production degree of difficulty of plastic lens. The focal length F8 of the eighth lens L8 and the effective focal length F of the fixed-focus lens satisfy: F8/F is more than or equal to-5.6 and less than or equal to-2.6, light can smoothly enter the image plane IMA, a defocusing curve is concentrated, and the resolution performance of the lens is improved.
In the embodiment of the present invention, the fixed-focus lens further includes an optical filter (in fig. 1 to 4, the optical filter is denoted as one surface S13), and an optical effective aperture SDF of the optical filter and an optical effective semi-aperture SD1 of the first lens L1 satisfy: SDF/SD1 is more than or equal to 0.6 and less than or equal to 0.9, and can filter light, further improve the resolution performance and ensure the maximum light flux.
In the embodiment of the present invention, the optical effective diameter SDS of the stop STO and the optical effective half-aperture SD1 of the first lens L1 satisfy: SDS/SD1 is more than or equal to 0.5 and less than or equal to 0.9, so that the aperture is large enough, and the ultra-large aperture function of the infrared state of the lens is realized by changing the aperture.
In conclusion, by adopting the technical scheme, the fixed focus lens with the large target surface, the ultra-large aperture, the low cost, the miniaturization and the high imaging performance is obtained, the imaging is clear within the temperature range of minus 40 ℃ to plus 80 ℃, and the fixed focus lens can be suitable for a large target surface chip of 1/1.8'. Meanwhile, the lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
The following describes four embodiments of the fixed focus lens of the present invention with reference to the drawings and tables. In the following embodiments, the present invention designates the stop STO as one surface, the cemented surface of the cemented lens group as one surface, the optical filter as one surface, the parallel plate CG as two surfaces, and the image plane IMA as one surface.
The parameters of each example specifically satisfying the above conditional expressions are shown in table 1 below:
Figure BDA0003855153640000071
Figure BDA0003855153640000081
TABLE 1
In an embodiment of the present invention, the aspheric lens of the fixed-focus lens satisfies the following formula:
Figure BDA0003855153640000082
in the above formula, z is the axial distance from the curved surface to the vertex at the position of the height h perpendicular to the optical axis along the optical axis direction; c represents a curvature at the vertex of the aspherical surface; k is a conic coefficient; a. The 4 、A 6 、A 8 、A 10 、A 12 、A 14 、A 16 ··And represents the aspheric coefficients of fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders, respectively.
Example one
Referring to fig. 1, the parameters of the fixed-focus lens of the present embodiment are as follows:
fno:1.09; total optical length TTL:30.30mm. The third lens L3 is a paraxial convex-concave lens, the fourth lens L4 is a convex-concave lens, and the fifth lens L5 is a concave-concave lens.
The relevant parameters of each lens in the fixed-focus lens of the embodiment include: surface type, radius of curvature, thickness, refractive index of the material and abbe number, as shown in table 2 below.
Figure BDA0003855153640000083
Figure BDA0003855153640000091
TABLE 2
The aspheric surface coefficients of the aspheric surface lenses of the prime lens of the embodiment include: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface 4 Sixth order aspherical surface coefficient A 6 Eighth order aspheric surface coefficient A 8 Ten-order aspheric surface coefficient A 10 Twelve-order aspheric surface coefficient A 12 Fourteen-order aspheric surface coefficient A 14 And a sixteen-order aspheric coefficient A 16 As shown in table 3 below.
Figure BDA0003855153640000092
Figure BDA0003855153640000101
TABLE 3
As shown in fig. 1 and fig. 2 and tables 1 to 3, the fixed focus lens of the present embodiment has the characteristics of large target surface, ultra-large aperture, low cost, miniaturization and high imaging performance, can clearly image in the temperature range of-40 ℃ to +80 ℃, and is applicable to 1/1.8' large target surface chips. Meanwhile, the lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
Example two
Referring to fig. 3, the parameters of the fixed-focus lens of the present embodiment are as follows:
fno:1.10; total optical length TTL:30.30mm. The third lens L3 is a paraxial region convex-concave lens, the fourth lens L4 is a convex-concave lens, and the fifth lens L5 is a concave-concave lens.
The relevant parameters of each lens in the fixed-focus lens of the embodiment include: surface type, radius of curvature, thickness, refractive index of the material and abbe number are shown in table 4 below.
Figure BDA0003855153640000102
Figure BDA0003855153640000111
TABLE 4
The aspheric coefficients of the aspheric lenses of the fixed-focus lens of the present embodiment include: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface 4 Sixth order aspherical surface coefficient A 6 Eighth order aspheric surface coefficient A 8 Ten-order aspheric surface coefficient A 10 Twelve-order aspheric surface coefficient A 12 Fourteen-order aspheric surface coefficient A 14 And a sixteen-order aspheric surface coefficient A 16 As shown in table 5 below.
Figure BDA0003855153640000112
Figure BDA0003855153640000121
TABLE 5
As shown in fig. 3 and 4 and tables 1, 4 and 5, the fixed focus lens of the present embodiment has the characteristics of large target surface, ultra-large aperture, low cost, miniaturization and high imaging performance, can clearly image in the temperature range of-40 ℃ to +80 ℃, and is suitable for 1/1.8' large target surface chips. Meanwhile, the lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
EXAMPLE III
Referring to fig. 5, the parameters of the fixed focus lens of the present embodiment are as follows:
fno:1.07; total optical length TTL:28.51mm. The third lens L3 is a paraxial region convex-concave lens, the fourth lens L4 is a convex-concave lens, and the fifth lens L5 is a concave-concave lens.
The relevant parameters of each lens in the fixed-focus lens of the embodiment include: surface type, radius of curvature, thickness, refractive index of the material and abbe number are shown in table 6 below.
Figure BDA0003855153640000122
Figure BDA0003855153640000131
TABLE 6
The aspheric surface coefficients of the aspheric surface lenses of the prime lens of the embodiment include: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface 4 Sixth order aspherical surface coefficient A 6 Eighth order aspheric surface coefficient A 8 Ten-order aspheric surface coefficient A 10 Twelve-order aspheric surface coefficient A 12 Fourteen-order aspheric surface coefficient A 14 And a sixteen-order aspheric coefficient A 16 As shown in table 7 below.
Figure BDA0003855153640000132
TABLE 7
As shown in fig. 5 and fig. 6 and tables 1, 6, and 7, the fixed-focus lens of the present embodiment has the characteristics of a large target surface, an ultra-large aperture, low cost, miniaturization, and high imaging performance, and can clearly image in a temperature range of-40 ℃ to +80 ℃, and is applicable to a 1/1.8' large target surface chip. Meanwhile, the lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
Example four
Referring to fig. 7, the parameters of the fixed-focus lens of the present embodiment are as follows:
fno:1.07; total optical length TTL:30.30mm. The third lens L3 is a paraxial convex-concave lens, the fourth lens L4 is a convex-convex lens, and the fifth lens L5 is a concave-convex lens.
The relevant parameters of each lens in the fixed-focus lens of the embodiment include: surface type, radius of curvature, thickness, refractive index of the material and abbe number, as shown in table 8 below.
Figure BDA0003855153640000141
Figure BDA0003855153640000151
TABLE 8
The aspheric surface coefficients of the aspheric surface lenses of the prime lens of the embodiment include: the quadric surface constant K and the fourth-order aspheric surface coefficient A of the surface 4 Sixth order aspherical surface coefficient A 6 Eighth order aspheric surface coefficient A 8 Ten-order aspheric surface coefficient A 10 Twelve-order aspheric surface coefficient A 12 Fourteen-order aspheric surface coefficient A 14 And a sixteen-order aspheric coefficient A 16 As shown in table 9 below.
Figure BDA0003855153640000152
TABLE 9
As shown in fig. 7 and fig. 8 and tables 1, 8 and 9, the fixed focus lens of the present embodiment has the characteristics of large target surface, ultra-large aperture, low cost, miniaturization and high imaging performance, can image clearly in the temperature range of-40 ℃ to +80 ℃, and is applicable to 1/1.8' large target surface chips. Meanwhile, the lens can support two gears of F1.0/F1.6 under visible light, and the day and night confocal function is realized under the gear of F1.6.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A fixed focus lens, comprising, in order from an object side to an image side along an optical axis: a first lens (L1) with negative focal power, a second lens (L2) with positive focal power, a third lens (L3) with positive focal power, a diaphragm (STO), a fourth lens (L4) with positive focal power, a fifth lens (L5) with negative focal power, a sixth lens (L6) with positive focal power, a seventh lens (L7) with positive focal power and an eighth lens (L8) with negative focal power,
the shape of the object side surface of the fifth lens (L5) is concave, the sixth lens (L6) is a convex lens, and the eighth lens (L8) is a paraxial region concave-convex lens.
2. The prime lens according to claim 1, wherein in a direction from an object side to an image side along an optical axis,
the first lens (L1) is a paraxial region convex-concave lens;
the second lens (L2) is a meniscus lens;
the paraxial region of the object side surface of the third lens (L3) is convex;
the shape of the image side surface of the fourth lens (L4) is convex;
the seventh lens (L7) is a convex lens.
3. The prime lens according to claim 1, wherein the first lens (L1), the second lens (L2), the third lens (L3), the seventh lens (L7), and the eighth lens (L8) are aspheric lenses;
the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are spherical lenses.
4. The prime lens according to claim 1, wherein the first lens (L1), the second lens (L2), the third lens (L3), the seventh lens (L7) and the eighth lens (L8) are plastic lenses;
the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are glass lenses.
5. Prime lens according to claim 1, characterized in that the fourth lens (L4) and the fifth lens (L5) are cemented to form a cemented lens group.
6. The prime lens according to claim 5, wherein the focal length F45 of the cemented lens group and the effective focal length F of the prime lens satisfy: F45/F is more than or equal to-4.0 and less than or equal to 16.5.
7. The fixed-focus lens according to claim 5, wherein the focal length F45 of the cemented lens group and the back group focal length FB of the fixed-focus lens satisfy: F45/FB of-2.2 is less than or equal to 10.5.
8. The fixed-focus lens according to any one of claims 1 to 7, wherein an optical total length TTL of the fixed-focus lens and a back focal length BFL of the fixed-focus lens satisfy: TTL/BFL is more than or equal to 5.8 and less than or equal to 8.0.
9. The fixed-focus lens according to any one of claims 1 to 7, wherein an effective focal length F of the fixed-focus lens and a back focal length BFL of the fixed-focus lens satisfy: F/BFL is more than or equal to 1.0 and less than or equal to 1.5.
10. The fixed-focus lens according to any one of claims 1 to 7, wherein an effective focal length F of the fixed-focus lens and a maximum image height IH of the fixed-focus lens satisfy: F/IH is more than or equal to 0.4 and less than or equal to 0.8.
CN202211145666.7A 2022-09-20 2022-09-20 Fixed focus lens Pending CN115542516A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211145666.7A CN115542516A (en) 2022-09-20 2022-09-20 Fixed focus lens

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211145666.7A CN115542516A (en) 2022-09-20 2022-09-20 Fixed focus lens

Publications (1)

Publication Number Publication Date
CN115542516A true CN115542516A (en) 2022-12-30

Family

ID=84727437

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211145666.7A Pending CN115542516A (en) 2022-09-20 2022-09-20 Fixed focus lens

Country Status (1)

Country Link
CN (1) CN115542516A (en)

Similar Documents

Publication Publication Date Title
WO2023143239A1 (en) Optical lens
US8699143B2 (en) Wide-angle lens, imaging apparatus, and method for manufacturing wide-angle lens
CN114675404B (en) Optical lens
CN114265186B (en) Optical lens
CN114509859A (en) Optical lens and electronic device
CN109683291B (en) Optical lens and imaging apparatus
CN114675406A (en) Optical lens
CN218158525U (en) Fixed focus lens
CN216696829U (en) Vehicle-mounted optical lens
CN115494627A (en) Fixed focus lens
JP4210876B2 (en) Zoom lens
CN217879791U (en) Fixed focus lens
CN214845994U (en) Fixed focus lens
CN115542516A (en) Fixed focus lens
CN113534414A (en) Fixed focus lens
CN114488468A (en) Optical lens and electronic device
CN218956904U (en) Optical lens
CN114879350B (en) Fixed focus lens
CN114265185B (en) Optical lens and imaging device
CN218332133U (en) Fixed focus lens
CN114690383B (en) Optical lens
CN114815186B (en) Optical lens
CN221056744U (en) Day and night confocal lens
CN219533496U (en) Image pickup lens
CN117310944B (en) Optical lens

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination