CN216083243U - 25mm focal length lens - Google Patents
25mm focal length lens Download PDFInfo
- Publication number
- CN216083243U CN216083243U CN202122734038.XU CN202122734038U CN216083243U CN 216083243 U CN216083243 U CN 216083243U CN 202122734038 U CN202122734038 U CN 202122734038U CN 216083243 U CN216083243 U CN 216083243U
- Authority
- CN
- China
- Prior art keywords
- lens
- object side
- image side
- focal length
- diopter
- 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.)
- Active
Links
Images
Landscapes
- Lenses (AREA)
Abstract
The utility model discloses a 25mm focal length lens, which comprises a first lens, a second lens, a third lens, an iris diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along an optical axis from an object side to an image side, wherein the first lens has positive diopter, the second lens has positive diopter, the third lens has negative diopter, the fourth lens has negative diopter, the fifth lens has positive diopter, the sixth lens has positive diopter, the seventh lens has negative diopter, and only the lens with the diopter has the above 7 lenses. The 25mm focal length lens adopts 7 glass lenses, has the characteristics of high resolution, wide range of working object distance, wide light passing range and the like, can not lose focus within the temperature range of-40-80 ℃, ensures high image quality, can support the use in the spectrum range of 435-656nm, and has wider applicable spectrum range.
Description
Technical Field
The utility model relates to the technical field of optical lenses, in particular to a 25mm focal length lens.
Background
With the continuous progress of science and technology and the continuous development of society, in recent years, optical imaging lenses are widely applied to various fields and are rapidly developed, and the requirements on the optical imaging lenses are higher and higher.
At present, the lens for machine vision mainly has the following defects: because the back focus is greatly influenced by temperature, the lens is only limited to be used at the temperature of minus 20-60 ℃ in order to ensure the imaging quality, more than 7 lenses are usually adopted in order to obtain high-definition image quality, the light passing is also limited to be F2.5-F16, in addition, the working object distance range is small, the optimal working object distance of the lens is not matched with the object distance used by machine vision, the optimal performance of the lens cannot be exerted in practical use, and the spectral range only supports 460-650 nm.
In view of this, the inventor of the present application invented a 25mm focal length lens.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a 25mm focal length lens which is high in resolution, wide in working object distance range, stable in high and low temperature imaging and wide in light passing range.
In order to achieve the purpose, the utility model adopts the following technical scheme: a25 mm focal length lens comprises a first lens, a second lens, a third lens, an iris diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along an optical axis from an object side to an image side, wherein the first lens to the seventh lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass and an image side surface facing the image side and allowing the imaging light rays to pass;
the first lens has positive diopter, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a plane;
the second lens has positive diopter, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface;
the third lens has negative diopter, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a concave surface;
the fourth lens has negative diopter, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface;
the fifth lens has positive diopter, and the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface;
the sixth lens has positive diopter, and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface;
the seventh lens has negative diopter, and the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a concave surface.
The lens with the refractive index only has the 7 lenses.
Further, the lens satisfies: 1.1< | (f1/f) | <1.2, 0.6< | (f2/f) | <0.7, 0.3< | (f3/f) | <0.4, 0.3< | (f4/f) | <0.4, 0.3< | (f5/f) | <0.4, 0.65< | (f6/f) | <0.7, 0.75< | (f7/f) | <0.85,
wherein f is 25mm and is the focal length of the lens, and f1, f2, f3, f4, f5, f6 and f7 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, respectively.
Further, the image side surface of the second lens and the object side surface of the third lens are mutually glued, and the difference value of the dispersion coefficients of the second lens and the third lens is larger than 50.
Further, the image side surface of the fourth lens and the object side surface of the fifth lens are mutually glued.
Further, the temperature coefficient of the refractive index of the second lens is a negative value.
Further, the first to seventh lenses are all glass spherical lenses.
After the technical scheme is adopted, the utility model has the following advantages:
the 25mm focal length lens adopts 7 glass lenses, has the characteristics of high resolution, wide range of working object distance, wide light passing range and the like, can not lose focus within the temperature range of-40-80 ℃, ensures high image quality, can support the use in the spectrum range of 435-656nm, and has wider applicable spectrum range.
Drawings
FIG. 1 is a light path diagram of embodiment 1 of the present invention;
fig. 2 is a graph of MTF under visible light of the lens in embodiment 1 of the present invention;
FIG. 3 is a lateral chromatic aberration curve under visible light for the lens of embodiment 1 of the present invention;
fig. 4 is a graph of relative illuminance of the lens under visible light in embodiment 1 of the present invention;
FIG. 5 is a light path diagram of embodiment 2 of the present invention;
fig. 6 is a graph of MTF under visible light of the lens in embodiment 2 of the present invention;
FIG. 7 is a lateral chromatic aberration curve under visible light for the lens of embodiment 2 of the present invention;
fig. 8 is a graph of relative illuminance of the lens under visible light in embodiment 2 of the present invention;
FIG. 9 is a light path diagram of embodiment 3 of the present invention;
fig. 10 is a graph of MTF under visible light for a lens in embodiment 3 of the present invention;
fig. 11 is a lateral chromatic aberration curve of the lens in embodiment 3 of the present invention under visible light;
fig. 12 is a graph of relative illuminance of the lens under visible light in embodiment 3 of the present invention;
FIG. 13 is a light path diagram of embodiment 4 of the present invention;
fig. 14 is a graph of MTF under visible light for a lens in embodiment 4 of the present invention;
FIG. 15 is a graph of lateral chromatic aberration of a lens in visible light according to embodiment 4 of the present invention;
fig. 16 is a graph of relative illuminance of the lens under visible light in embodiment 4 of the present invention.
Description of reference numerals:
1. a first lens; 2. a second lens; 3. a third lens; 4. a fourth lens; 5. a fifth lens; 6. A sixth lens; 7. a seventh lens; 8. a diaphragm; 9. and (4) protecting the glass.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.
In the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the apparatus or element of the present invention must have a specific orientation, and thus, should not be construed as limiting the present invention.
As used herein, the term "a lens element having a positive refractive index (or a negative refractive index)" means that the paraxial refractive index of the lens element calculated by Gaussian optics is positive (or negative). The term "object-side (or image-side) of a lens" is defined as the specific range of imaging light rays passing through the lens surface. The determination of the surface shape of the lens can be performed by the judgment method of a person skilled in the art, i.e., by the sign of the curvature radius (abbreviated as R value). The R value may be commonly used in optical design software, such as Zemax or CodeV. The R value is also commonly found in lens data sheets (lens data sheets) of optical design software. When the R value is positive, the object side is judged to be a convex surface; and when the R value is negative, judging that the object side surface is a concave surface. On the contrary, regarding the image side surface, when the R value is positive, the image side surface is judged to be a concave surface; when the R value is negative, the image side surface is judged to be convex.
The utility model discloses a 25mm focal length lens which is mainly suitable for machine vision and can be used for other available scenes without limitation. The zoom lens specifically comprises a first lens 1, a second lens 2, a third lens 3, an iris diaphragm 8, a fourth lens 4, a fifth lens 5, a sixth lens 6 and a seventh lens 7 which are sequentially arranged along an optical axis from an object side to an image side, wherein the first lens 1 to the seventh lens 7 respectively comprise an object side surface facing the object side and allowing imaging light rays to pass through and an image side surface facing the image side and allowing the imaging light rays to pass through;
the first lens 1 has positive diopter, the object side surface of the first lens 1 is a convex surface, and the image side surface is a plane;
the second lens element 2 has positive diopter, and the object-side surface of the second lens element 2 is a convex surface and the image-side surface is a convex surface;
the third lens 3 has negative diopter, and the object side surface of the third lens 3 is a concave surface, and the image side surface is a concave surface;
the fourth lens 4 has negative diopter, and the object side surface of the fourth lens 4 is a concave surface, and the image side surface is a concave surface;
the fifth lens 5 has positive diopter, and the object side surface of the fifth lens 5 is a convex surface, and the image side surface is a convex surface;
the sixth lens element 6 has a positive refractive power, and an object-side surface of the sixth lens element 6 is a convex surface and an image-side surface thereof is a convex surface;
the seventh lens element 7 has a negative refractive power, and the object-side surface of the seventh lens element 7 is a concave surface and the image-side surface is a concave surface.
The lens with the refractive index only has the above 7 lenses, and the first to seventh lenses 7 are all glass spherical lenses.
The lens satisfies the following conditions: 1.1< | (f1/f) | <1.2, 0.6< | (f2/f) | <0.7, 0.3< | (f3/f) | <0.4, 0.3< | (f4/f) | <0.4, 0.3< | (f5/f) | <0.4, 0.65< | (f6/f) | <0.7, 0.75< | (f7/f) | <0.85,
where f is 25mm and is the focal length of the lens, and f1, f2, f3, f4, f5, f6, and f7 are the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7, respectively. The focal power is reasonably distributed, and the optical performance is improved.
The image side surface of the second lens 2 and the object side surface of the third lens 3 are mutually glued, and the difference value of the dispersion coefficients of the second lens 2 and the third lens 3 is larger than 50. The difference value of the dispersion coefficients of the two lenses of the group of cemented lenses is large, and the chromatic aberration of the system can be effectively corrected, so that the transverse chromatic aberration of the lens is controlled within 1.4um, the blue-violet chromatic aberration of the picture is avoided, and the image color reducibility is high.
The image side surface of the fourth lens 4 and the object side surface of the fifth lens 5 are mutually glued. The cemented lens group consisting of the fourth lens 4 and the fifth lens 5 and the cemented lens group consisting of the second lens 2 and the third lens 3 form a double-gauss symmetrical structure, so that high-level aberration of the system can be effectively corrected, and the imaging quality is ensured.
The temperature coefficient of the refractive index of the second lens 2 is negative, and specifically, the material of the second lens 2 is H-FK 61. The material of the second lens 2 is selected to offset the influence of temperature change on the back focal offset of the lens, so that the lens can clearly image when being used in a temperature range of-40 ℃ to 80 ℃, thereby effectively ensuring the imaging quality.
The nearest working object distance of the lens is 0.2m, the optimal working object distance of the lens is 0.5m, and the lens is matched with the actual object distance used by machine vision, so that the optimal imaging quality can be ensured.
The lens is matched with an 2/3 sensor for use, the MTF value can reach 200lp/mm, the resolution of 10M can be supported, and the imaging quality is high.
The lens can change the light transmission and can support the light transmission in the range of F1.8-F32.
The lens can support the spectrum range of 435-656nm for use.
The mini infrared imaging lens of the present invention will be described in detail with specific embodiments.
Example 1
Referring to fig. 1, the present invention discloses a 25mm focal length lens, which includes a first lens element 1, a second lens element 2, a third lens element 3, an iris 8, a fourth lens element 4, a fifth lens element 5, a sixth lens element 6, and a seventh lens element 7, which are sequentially disposed along an optical axis from an object side to an image side, wherein each of the first lens element 1 to the seventh lens element 7 includes an object side surface facing the object side and allowing an imaging light to pass therethrough, and an image side surface facing the image side and allowing the imaging light to pass therethrough;
the first lens 1 has positive diopter, the object side surface of the first lens 1 is a convex surface, and the image side surface is a plane;
the second lens element 2 has positive diopter, and the object-side surface of the second lens element 2 is a convex surface and the image-side surface is a convex surface;
the third lens 3 has negative diopter, and the object side surface of the third lens 3 is a concave surface, and the image side surface is a concave surface;
the fourth lens 4 has negative diopter, and the object side surface of the fourth lens 4 is a concave surface, and the image side surface is a concave surface;
the fifth lens 5 has positive diopter, and the object side surface of the fifth lens 5 is a convex surface, and the image side surface is a convex surface;
the sixth lens element 6 has a positive refractive power, and an object-side surface of the sixth lens element 6 is a convex surface and an image-side surface thereof is a convex surface;
the seventh lens element 7 has a negative refractive power, and the object-side surface of the seventh lens element 7 is a concave surface and the image-side surface is a concave surface.
The lens with the refractive index only has the above 7 lenses, and the first to seventh lenses 7 are all glass spherical lenses.
In this embodiment, the image-side surface of the second lens element 2 and the object-side surface of the third lens element 3 are cemented with each other, and the image-side surface of the fourth lens element 4 and the object-side surface of the fifth lens element 5 are cemented with each other.
The detailed optical data of this embodiment are shown in Table 1-1.
Table 1-1 detailed optical data for example 1
In this embodiment, the focal length F of the lens is 25mm, the lens pass light is F1.83, the total optical length TTL of the lens is 40.32mm, and the chief ray angle CRA is 11.3 °.
In this embodiment, please refer to fig. 2 for an MTF graph of the lens under visible light, and it can be seen from the graph that when the spatial frequency of the lens reaches 200lp/mm, the MTF value still remains about 0.3, the imaging quality is good, the resolution of the lens is high, and the lens can support 10M resolution. Please refer to fig. 3, which shows that the chromatic aberration is controlled within 1.4um, and the chromatic aberration is corrected properly, so that the blue-violet edge phenomenon is avoided and the color reducibility is high. Referring to fig. 4, it can be seen that the relative illumination of the lens under visible light is greater than 75%, the edge illumination value is high, the overall illumination of the image is uniform, and the imaging quality is good.
Example 2
As shown in fig. 5, this embodiment is different from embodiment 1 mainly in the optical parameters such as the curvature radius of each lens surface and the lens thickness.
The detailed optical data of this embodiment is shown in Table 2-1.
Table 2-1 detailed optical data for example 2
In this embodiment, the focal length F of the lens is 25mm, the lens pass light is F1.83, the total optical length TTL of the lens is 40.32mm, and the chief ray angle CRA is 11.4 °.
In this embodiment, please refer to fig. 6 for an MTF graph of the lens under visible light, and it can be seen from the graph that when the spatial frequency of the lens reaches 200lp/mm, the MTF value still remains about 0.3, the imaging quality is good, the resolution of the lens is high, and the lens can support 10M resolution. Please refer to fig. 7, which shows that the chromatic aberration is controlled within 1.5um, and the chromatic aberration is corrected properly, so that the blue-violet edge phenomenon is avoided and the color reducibility is high. Referring to fig. 8, it can be seen that the relative illuminance of the lens under visible light is greater than 75%, the edge illuminance value is high, the overall illuminance of the image is uniform, and the imaging quality is good.
Example 3
As shown in fig. 9, this embodiment is different from embodiment 1 mainly in the optical parameters such as the curvature radius of each lens surface and the lens thickness.
The detailed optical data of this embodiment is shown in Table 3-1.
Table 3-1 detailed optical data for example 3
In this embodiment, the focal length F of the lens is 25mm, the lens pass light is F1.83, the total optical length TTL of the lens is 40.32mm, and the chief ray angle CRA is 12.5 °.
In this embodiment, please refer to fig. 10 for an MTF graph of the lens under visible light, and it can be seen from the graph that when the spatial frequency of the lens reaches 200lp/mm, the MTF value still remains about 0.3, the imaging quality is good, the resolution of the lens is high, and the lens can support 10M resolution. Please refer to fig. 11, which shows that the chromatic aberration is controlled within 1.0um, and the chromatic aberration is corrected properly, so that the blue-violet edge phenomenon is avoided and the color reducibility is high. Referring to fig. 12, it can be seen that the relative illuminance of the lens under visible light is greater than 75%, the edge illuminance value is high, the overall illuminance of the image is uniform, and the imaging quality is good.
Example 4
As shown in fig. 13, this embodiment is different from embodiment 1 mainly in the optical parameters such as the curvature radius of each lens surface and the lens thickness.
The detailed optical data of this embodiment is shown in Table 4-1.
Table 4-1 detailed optical data for example 4
In this embodiment, the focal length F of the lens is 25mm, the lens pass light is F1.83, the total optical length TTL of the lens is 40.31mm, and the chief ray angle CRA is 11.5 °.
In this embodiment, please refer to fig. 14 for the MTF graph of the lens under visible light, and it can be seen from the graph that when the spatial frequency of the lens reaches 200lp/mm, the MTF value still remains about 0.3, the imaging quality is excellent, the resolution of the lens is high, and the lens can support 10M resolution. Please refer to fig. 15, which shows that the chromatic aberration is controlled within 1.4um, and the chromatic aberration is corrected properly, so that the blue-violet edge phenomenon is avoided and the color reducibility is high. Referring to fig. 16, it can be seen that the relative illuminance of the lens under visible light is greater than 75%, the edge illuminance value is high, the overall illuminance of the image is uniform, and the imaging quality is good.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (6)
1. A25 mm focal length lens, its characterized in that: the zoom lens comprises a first lens, a second lens, a third lens, an iris diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an object side to an image side along an optical axis, wherein the first lens to the seventh lens respectively comprise an object side surface facing the object side and allowing imaging light rays to pass and an image side surface facing the image side and allowing the imaging light rays to pass;
the first lens has positive diopter, the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a plane;
the second lens has positive diopter, and the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a convex surface;
the third lens has negative diopter, the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a concave surface;
the fourth lens has negative diopter, the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a concave surface;
the fifth lens has positive diopter, and the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface;
the sixth lens has positive diopter, and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface;
the seventh lens has negative diopter, the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a concave surface;
the lens with the refractive index only has the 7 lenses.
2. A 25mm focal length lens as claimed in claim 1, wherein: the lens satisfies the following conditions: 1.1< | (f1/f) | <1.2, 0.6< | (f2/f) | <0.7, 0.3< | (f3/f) | <0.4, 0.3< | (f4/f) | <0.4, 0.3< | (f5/f) | <0.4, 0.65< | (f6/f) | <0.7, 0.75< | (f7/f) | <0.85,
wherein f is 25mm and is the focal length of the lens, and f1, f2, f3, f4, f5, f6 and f7 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens, respectively.
3. A 25mm focal length lens as claimed in claim 1, wherein: the image side surface of the second lens and the object side surface of the third lens are mutually glued, and the difference value of the dispersion coefficients of the second lens and the third lens is larger than 50.
4. A 25mm focal length lens as claimed in claim 3, wherein: and the image side surface of the fourth lens and the object side surface of the fifth lens are mutually glued.
5. A 25mm focal length lens as claimed in claim 1, wherein: the temperature coefficient of the refractive index of the second lens is a negative value.
6. A 25mm focal length lens as claimed in claim 1, wherein: the first lens, the second lens, the third lens and the fourth lens are all glass spherical lenses.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122734038.XU CN216083243U (en) | 2021-11-09 | 2021-11-09 | 25mm focal length lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122734038.XU CN216083243U (en) | 2021-11-09 | 2021-11-09 | 25mm focal length lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216083243U true CN216083243U (en) | 2022-03-18 |
Family
ID=80660224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122734038.XU Active CN216083243U (en) | 2021-11-09 | 2021-11-09 | 25mm focal length lens |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216083243U (en) |
-
2021
- 2021-11-09 CN CN202122734038.XU patent/CN216083243U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110361833B (en) | Optical imaging lens | |
| CN110596857B (en) | Wide-angle lens and imaging apparatus | |
| CN110456486B (en) | Optical imaging lens | |
| CN108445608B (en) | High-pixel wide-angle infrared optical system and camera module applying same | |
| CN109870787A (en) | A kind of optical imaging lens | |
| CN111722378A (en) | Large-image-plane high-resolution fisheye lens | |
| CN113253434B (en) | Optical lens and imaging apparatus | |
| CN210294655U (en) | Optical imaging lens | |
| CN112612115A (en) | Optical imaging lens | |
| CN111638586A (en) | Glass-plastic mixed infrared confocal lens | |
| CN216526495U (en) | Focus-adjustable scanning lens containing liquid lens | |
| CN213814107U (en) | Optical imaging lens | |
| CN216434516U (en) | Wide-angle video transmission lens matched with liquid lens | |
| CN216083243U (en) | 25mm focal length lens | |
| CN213780519U (en) | Optical imaging lens | |
| CN213780517U (en) | Optical imaging lens | |
| CN213482550U (en) | Wide-angle optical imaging lens | |
| CN212321962U (en) | Glass-plastic mixed infrared confocal lens | |
| CN112433344A (en) | Optical imaging lens | |
| CN211955958U (en) | Ultrashort high definition wide-angle lens | |
| CN212321968U (en) | Large-image-plane high-resolution fisheye lens | |
| CN212321969U (en) | Wide-angle low-distortion optical imaging lens | |
| CN209842203U (en) | Optical imaging lens | |
| CN109683279B (en) | Large aperture infrared confocal optical system | |
| CN112612116A (en) | Optical imaging lens |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |