CN214845994U - Fixed focus lens - Google Patents
Fixed focus lens Download PDFInfo
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- CN214845994U CN214845994U CN202120567172.2U CN202120567172U CN214845994U CN 214845994 U CN214845994 U CN 214845994U CN 202120567172 U CN202120567172 U CN 202120567172U CN 214845994 U CN214845994 U CN 214845994U
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Abstract
The utility model relates to a prime lens, include along optical axis from the thing side to the image side arrange in proper order: a first lens (L1) having a negative optical power, a second lens (L2) having a positive optical power, a third lens (L3) having a positive optical power, a fourth lens (L4) having a negative optical power, and a fifth lens (L5) having a positive optical power. The utility model discloses a tight shot's imaging performance is better, and simple structure is reasonable, the cost is lower, can realize that visible infrared is confocal and do not have the thermalization.
Description
Technical Field
The utility model relates to an optical imaging technical field especially relates to a tight shot.
Background
The chief ray angle CRA of the small-volume prime lens in the prior art is larger, and the design of the all-glass lens is more, so that the miniaturization is not facilitated, and the cost is increased. The plastic lens can reduce the manufacturing cost to a certain extent, and meanwhile, the plastic aspheric lens also improves the resolving power of the lens, so that the lens competitiveness is improved. However, since the plastic material itself has a side effect of a large thermal expansion coefficient, a lens using the plastic lens has a defect such as defocus even in a high-temperature and low-temperature state.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a better tight shot of formation of image performance.
In order to achieve the above object of the present invention, the present invention provides a fixed focus lens, which includes a plurality of lenses arranged in sequence from an object side to an image side along an optical axis: the lens system includes a first lens having a negative power, a second lens having a positive power, a third lens having a positive power, a fourth lens having a negative power, and a fifth lens having a positive power.
According to an aspect of the present invention, the optical module further comprises a diaphragm located between the first lens and the second lens or between the second lens and the third lens.
According to an aspect of the present invention, the first lens is a convex-concave lens, the second lens is a convex-concave lens, the third lens is a biconvex lens, the fourth lens is a biconcave lens, and the fifth lens is a biconvex lens.
According to the utility model discloses an aspect, first lens fourth lens with fifth lens are plastic aspheric lens, third lens is glass lens, the second lens is plastic aspheric lens or glass lens.
According to an aspect of the present invention, the following relations are satisfied between the rise SAG11 of the first lens object side maximum optical effective diameter and its curvature radius R1 and between the rise SAG12 of the first lens image side maximum optical effective diameter and its curvature radius R2, respectively:
1.0≤R1/SAG11≤1.5；
0.5≤R2/SAG12≤1.0。
according to an aspect of the present invention, the radius of curvature R21 of the object-side surface of the second lens and the radius of curvature R12 of the image-side surface of the first lens satisfy the following relation:
-2.5≤R21/R12≤-1.5。
according to an aspect of the utility model, the chief ray angle CRA of the biggest visual field of tight shot satisfies following condition: CRA is less than or equal to 12 degrees.
According to an aspect of the present invention, the focal power Φ 3 of the third lens and the focal power Φ II of the lens group on the image side of the diaphragm satisfy the following relational expression:
0.7≤φ3/φII≤1.3。
according to an aspect of the present invention, the center on the object side of the first lens and the distance M1 of the diaphragm, the center on the image side of the fifth lens and the distance M2 of the diaphragm and the total optical length TTL of the fixed focus lens satisfy the following relations, respectively:
0.15≤M1/TTL≤0.32；
0.33≤M2/TTL≤0.51。
according to an aspect of the present invention, the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5 and the following relations are satisfied between the effective focal length f of the prime lens respectively:
-4.2≤f1/f≤-2.5；
2≤f2/f≤12；
1≤f3/f≤1.5；
-0.9≤f4/f≤-0.5；
0.5≤f5/f≤0.9。
according to one aspect of the present invention, the lens group on the image side of the diaphragm at least comprises one glass lens made of a low-dispersion-coefficient material having an abbe number Vd > 75.
According to an aspect of the present invention, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy the following relation:
-1.1≤f4/f5≤-0.6。
according to the utility model discloses an aspect, the optics total length TTL and the light ring FNO of tight shot satisfy following condition: TTL is less than or equal to 22.5mm, and FNO is less than or equal to 1.6.
According to the utility model discloses an aspect, the optics total length TTL of tight shot satisfies following relational expression with effective focal length f:
TTL/f≤3.0。
according to the utility model discloses a scheme utilizes the combination of the glass of each lens in the tight shot to mould combined material, concavity and convexity and positive and negative focal power for the imaging performance of tight shot is better, and simple structure is reasonable, the cost is lower, can realize that visible infrared is confocal and do not have the thermalization. The utility model discloses a rationally set up the diaphragm position and make astigmatic, field curvature, coma etc. aberration optimization of camera lens.
According to an aspect of the present invention, the following relations are satisfied between the rise SAG11 of the maximum optical effective diameter of the object side surface of the first lens and the curvature radius R1 thereof, and between the rise SAG12 of the maximum optical effective diameter of the image side surface of the first lens and the curvature radius R2 thereof, respectively: R1/SAG11 is more than or equal to 1.0 and less than or equal to 1.5; R2/SAG12 is more than or equal to 0.5 and less than or equal to 1.0. The relationship between the curvature radius and the rise can effectively control the aperture size of the first lens, so that the incident height of a chief ray entering the optical system can be reduced, the distortion is favorably reduced, the aberration of an off-axis field is corrected, and the number of the lenses is reduced.
According to an aspect of the present invention, the curvature radius R21 of the object-side surface of the second lens and the curvature radius R12 of the image-side surface of the first lens satisfy the following relation: R21/R12 is not less than-1.5 and not more than-2.5. The matching relation among the curvature radiuses can improve the light converging efficiency of the lens and is beneficial to reducing the volume of the lens at the front end of the lens.
According to the utility model discloses a scheme, the chief ray angle CRA of the biggest visual field of tight shot satisfies following condition: CRA is less than or equal to 12 degrees. Therefore, reflected light is reduced, the intensity of light transmitted through the lens to reach the sensor for imaging is increased, and the imaging quality is improved.
According to an aspect of the present invention, the focal power phi 3 of the third lens and the focal power phi II of the lens group located on the image side of the stop STO satisfy the following relation: phi 3/phi II is more than or equal to 0.7 and less than or equal to 1.3. The distribution mode among the focal powers can improve the transmissibility of light rays, reduce the volume of the lens and reduce the production cost.
According to the utility model discloses a scheme, satisfy the following relational expression between the distance M1 of the center on the first lens object side and the diaphragm, the center on the fifth lens image side and the distance M2 of diaphragm STO and the optics total length TTL of tight shot respectively: M1/TTL is more than or equal to 0.15 and less than or equal to 0.32; M2/TTL is more than or equal to 0.33 and less than or equal to 0.51. The position relation among the groups enables the whole lens to be more compact, and the size to be small and exquisite.
According to the utility model discloses a scheme, the focus of first lens is f1, the focus of second lens is f2, the focus of third lens is f3, the focus of fourth lens is f4, the focus of fifth lens is satisfied following relational expression between f5 and the effective focal length f of tight shot respectively: f1/f is not less than 4.2 and not more than-2.5; f2/f is more than or equal to 2 and less than or equal to 12; f3/f is more than or equal to 1 and less than or equal to 1.5; f4/f is more than or equal to-0.9 and less than or equal to-0.5; f5/f is more than or equal to 0.5 and less than or equal to 0.9. The reasonable positive and negative lens focal power distribution mode corrects the aberration of the optical system and ensures that the lens can be imaged clearly.
According to one aspect of the present invention, the lens assembly on the image side of the stop comprises at least one glass lens made of a low-dispersion-coefficient material having an abbe number Vd > 75. The material with low dispersion coefficient can correct chromatic aberration of the lens, so that the lens can clearly image visible and near infrared spectrums, and can balance resolution in high and low temperature states.
According to an aspect of the present invention, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy the following relation: f4/f5 is not less than-1.1 and not more than-0.6. The positive and negative focal powers are matched to improve the image quality and further control the focus drift of the lens in a reasonable range in a high and low temperature state.
According to the utility model discloses a scheme, the optics total length TTL and the light ring FNO of tight shot satisfy following condition: TTL is less than or equal to 22.5mm, and FNO is less than or equal to 1.6. The aperture as large as possible is realized under the condition of a certain total length, so that the imaging can be clear without focusing under the dark room conditions such as night and the like.
According to one scheme of the utility model, the total optical length TTL and the effective focal length f of the fixed-focus lens satisfy the following relational expression that TTL/f is less than or equal to 3.0. The proportional relation between the total optical length and the focal length of the lens reflects the characteristic of small and exquisite lens volume.
Drawings
Fig. 1 is a schematic view showing a construction of a fixed focus lens according to a first embodiment of the present invention;
fig. 2 is a schematic diagram showing a RayFan diagram of a fixed focus lens according to a first embodiment of the present invention;
fig. 3 schematically shows a field curvature-distortion diagram of a prime lens according to a first embodiment of the present invention;
fig. 4 is a schematic diagram showing a construction of a fixed focus lens according to a second embodiment of the present invention;
fig. 5 is a RayFan diagram schematically showing a fixed focus lens according to a second embodiment of the present invention;
fig. 6 schematically shows a field curvature-distortion diagram of a prime lens according to a second embodiment of the present invention;
fig. 7 is a schematic view showing a construction of a fixed focus lens according to a third embodiment of the present invention;
fig. 8 is a RayFan diagram schematically showing a fixed focus lens according to a third embodiment of the present invention;
fig. 9 is a view schematically showing a field curvature-distortion diagram of a prime lens according to a third embodiment of the present invention;
fig. 10 is a schematic diagram showing a construction of a fixed focus lens according to a fourth embodiment of the present invention;
fig. 11 is a RayFan diagram schematically showing a fixed focus lens according to a fourth embodiment of the present invention;
fig. 12 schematically shows a field curvature-distortion diagram of a prime lens according to a fourth embodiment of the present invention.
Detailed Description
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.
In describing embodiments of the present invention, the terms "longitudinal," "lateral," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and other terms are used in an orientation or positional relationship shown in the associated drawings for convenience in describing the invention and for simplicity in description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.
The present invention will be described in detail with reference to the accompanying drawings and specific embodiments, which are not repeated herein, but the present invention is not limited to the following embodiments.
Referring to fig. 1, the fixed focus lens of the present invention includes the following components arranged in sequence from the object side to the image side along the optical axis: a first lens L1 having a negative power, a second lens L2 having a positive power, a third lens L3 having a positive power, a fourth lens L4 having a negative power, and a fifth lens L5 having a positive power. Of course, a stop STO is further included, which may be located between the first lens L1 and the second lens L2 or between the second lens L2 and the third lens L3. The utility model discloses in, first lens L1 is convex-concave lens, and second lens L2 is meniscus lens, and third lens L3 is biconvex lens, and fourth lens L4 is biconcave lens, and fifth lens L5 is biconvex lens. The first lens element L1, the fourth lens element L4, and the fifth lens element L5 are aspheric plastic lenses, the third lens element L3 is a glass lens, and the second lens element L2 is an aspheric plastic lens or a glass lens. Therefore, the utility model discloses a form of glass-plastic hybrid lens collocation more than adopting in the tight shot to and the collocation optimization of positive and negative focal power, corrected the aberration and solved the camera lens at the high low temperature state's of 80 ℃ with-40 ℃ thermal drift problem, increased the use occasion and the environmental condition scope of camera lens.
The utility model discloses in, satisfy the following relational expression respectively between first lens L1 object side (being close to in the aspect of the thing) rise SAG11 of the biggest optical effective diameter and its radius of curvature R1 and first lens L1 look like the height SAG12 of the biggest optical effective diameter of side (being close to in the aspect of the image) and its radius of curvature R2: R1/SAG11 is more than or equal to 1.0 and less than or equal to 1.5; R2/SAG12 is more than or equal to 0.5 and less than or equal to 1.0. Thus, this relationship between the radius of curvature and the rise can effectively control the aperture size of the first lens L1, thereby reducing the incident height of the chief rays entering the optical system to reduce distortion and correct the aberration of the off-axis field. At the same time, this arrangement also reduces the number of lenses required.
The utility model discloses in, the radius of curvature R21 of second lens L2 object side and the radius of curvature R12 of first lens L1 looks side satisfy following relational expression: R21/R12 is not less than-1.5 and not more than-2.5. The matching relation among the curvature radiuses can improve the light converging efficiency of the lens and is beneficial to reducing the volume of the lens at the front end of the lens. The chief ray angle CRA of the maximum field of view of the prime lens satisfies the following condition: CRA is less than or equal to 12 degrees. The arrangement can reduce the generation of reflected light and increase the intensity of light transmitted through the lens to reach the sensor for imaging, thereby improving the imaging quality. The power Φ 3 of the third lens L3 and the power Φ II of the lens group on the image side of the stop STO satisfy the following relationship: phi 3/phi II is more than or equal to 0.7 and less than or equal to 1.3. The optical power distribution mode can improve the transmissibility of light rays in the lens, so that the volume of the lens is reduced, and the production cost is reduced. The following relationships are satisfied between the distance M1 between the center on the object-side surface of the first lens L1 and the stop STO, the distance M2 between the center on the image-side surface of the fifth lens L5 and the stop STO, and the total optical length TTL of the prime lens, respectively: M1/TTL is more than or equal to 0.15 and less than or equal to 0.32; M2/TTL is more than or equal to 0.33 and less than or equal to 0.51. The arrangement ensures that the position relation between the diaphragm object and the image group on the two sides can make the whole lens more compact, and the size of the lens is reduced.
The utility model discloses in, the focus of first lens L1 is f1, the focus of second lens L2 is f2, the focus of third lens L3 is f3, the focus of fourth lens L4 is f4, the focus of fifth lens L5 is f5 and the effective focal length f of tight shot satisfies the following relational expression between respectively: f1/f is not less than 4.2 and not more than-2.5; f2/f is more than or equal to 2 and less than or equal to 12; f3/f is more than or equal to 1 and less than or equal to 1.5; f4/f is more than or equal to-0.9 and less than or equal to-0.5; f5/f is more than or equal to 0.5 and less than or equal to 0.9. The aberration of the fixed-focus lens is corrected according to the positive and negative focal power distribution mode of each lens, and the imaging of the lens is ensured to be clear.
The utility model discloses in, be located the glass lens that contains the low dispersion coefficient material of an abbe number Vd > 75 at least in the battery of lens that diaphragm STO was seen side. The material with low dispersion coefficient can correct chromatic aberration of the lens, so that the lens can clearly image visible and near infrared spectrums, and can balance resolution in high and low temperature states. The focal length f4 of the fourth lens L4 and the focal length f5 of the fifth lens L5 satisfy the following relational expressions: f4/f5 is not less than-1.1 and not more than-0.6. Therefore, the positive and negative focal powers of the fourth lens L4 and the fifth lens L5 are matched to improve the image quality, and the focus drift of the lens in a high and low temperature state is further controlled to be within a reasonable range. The total optical length TTL and the aperture FNO of the fixed-focus lens meet the following conditions: TTL is less than or equal to 22.5mm, and FNO is less than or equal to 1.6. Therefore, the diaphragm as large as possible is realized under the condition of a certain total length, so that the image can be clearly formed without focusing under the dark room condition such as night. The total optical length TTL and the effective focal length f of the fixed-focus lens satisfy the following relational expression that TTL/f is less than or equal to 3.0. The proportional relation between the total optical length and the focal length of the lens realizes the advantage of small volume of the lens.
To sum up, the utility model discloses a total five pieces of lenses of tight shot, wherein plastic aspheric lens can reach four pieces of lens at most to can promote the performance of tight shot, and can make the cost greatly reduced of camera lens, with improvement product competitiveness. Moreover, aberration can be corrected by matching lens materials and focal power, and the problem of thermal drift of the lens at high and low temperatures of 80 ℃ and-40 ℃ is solved, so that the application occasions and the environmental condition range of the lens are enlarged. The arrangement of the lens made of at least one low-dispersion material can balance the purple fringing and high-quality imaging of near infrared light, so that the chromatic aberration of the lens is further corrected, visible infrared confocal is realized, and the market competitiveness of the lens is further improved.
The following describes the fixed focus lens of the present invention in detail with four embodiments. In the following embodiments, the surfaces of the respective lenses are denoted by 1, 2, …, and N, the stop may be denoted by STO, and the image plane located on the image side of the entire fixed focus lens is not shown in the drawings. All aspherical lens surface types of the following respective embodiments satisfy the following formula:
Z＝cy2/{1+[1-(1+k)c2y2]1/2}+a4y4+a6y6+a8y8+a10y10+a12y12+a14y14；
z is the axial distance from the curved surface to the top point at the position which is along the direction of the optical axis and is vertical to the optical axis by the height h; c represents the curvature at the apex of the aspherical surface; y is the radial coordinate of the aspheric lens; k is a conic coefficient; a is4、a6、a8、a10、a12、a14Respectively representing aspheric coefficients of fourth order, sixth order, eighth order, tenth order, twelfth order and fourteenth order.
The parameter settings of the following embodiments satisfy the following table 1:
TABLE 1
The first embodiment:
referring to fig. 1, the stop STO in the present embodiment is located between the first lens L1 and the second lens L2, and the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are aspheric lenses. Wherein, the focal length is: 8.06mm, FNO: 1.45, total length: 22.5 mm.
The parameters relating to each lens in the present embodiment include surface type, radius of curvature, k value, thickness, refractive index, and abbe number, and are shown in table 2:
| surface number | Surface type | Radius of curvature | Thickness of | Refractive index | Abbe number |
| 1 | Aspherical surface | 2.545 | 1.111 | 1.49 | 55.76 |
| 2 | Aspherical surface | 1.876 | 3.713 | ||
| 3(STO) | Spherical surface | Infinity | 1.317 | ||
| 4 | Aspherical surface | -3.869 | 1.764 | 1.62 | 27.78 |
| 5 | Aspherical surface | -3.378 | 0.116 | ||
| 6 | Spherical surface | 7.985 | 3.149 | 1.429 | 95.18 |
| 7 | Spherical surface | -8.226 | 0.115 | ||
| 8 | Aspherical surface | -29.928 | 0.378 | 1.64 | 23.53 |
| 9 | Aspherical surface | 3.316 | 0.155 | ||
| 10 | Aspherical surface | 5.097 | 3.692 | 1.60 | 39.9 |
| 11 | Aspherical surface | -7.427 | 5.99 | ||
| 12 | Spherical surface | Infinity | 0.80 | 1.517 | 64.2 |
| 13 | Spherical surface | Infinity | 0.20 | ||
| Image plane | Spherical surface | Infinity | - |
TABLE 2
The K value and aspherical surface coefficient of this embodiment are shown in tables 3 and 4 below:
TABLE 3
TABLE 4
As can be seen from fig. 2 and 3, the fixed-focus lens of the present embodiment, in combination with fig. 2, can be seen that the aberration of the fixed-focus lens of the present embodiment is better corrected within the spectral bandwidth, and the resolution is greatly improved, so that the definition of the real-shot image of the lens can be increased; fig. 3 shows that the field curvature and distortion can be corrected to a proper range, so that the meridional resolution can be close to the sagittal resolution, and the optimal imaging plane can be located in the vertical plane of the photosensitive surface of the chip, so that the image resolution of the lens is uniform.
The second embodiment:
referring to fig. 4, the stop STO in the present embodiment is located between the second lens L2 and the third lens L3, and the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are aspheric lenses. Wherein, the focal length is: 7.7mm, FNO:1.5, total length: 22.028 mm.
The parameters relating to each lens in the present embodiment include surface type, radius of curvature, k value, thickness, refractive index, and abbe number, and are shown in table 5:
TABLE 5
The K value and aspherical surface coefficient of this embodiment are shown in tables 6 and 7 below:
TABLE 6
| Surface number | a12 | a14 |
| 1 | -1.91588E-008 | -7.25001E-010 |
| 2 | -5.13927E-007 | 3.66901E-011 |
| 3 | 3.86707E-008 | -2.76602E-010 |
| 4 | 9.42359E-008 | 8.51741E-011 |
| 8 | -1.46809E-009 | 1.30402E-009 |
| 9 | -5.20514E-007 | 2.85403E-009 |
| 10 | 1.8910E-007 | -2.93021E-010 |
| 11 | 6.21331E-008 | 4.10703E-010 |
TABLE 7
As can be seen from fig. 5 and 6 in combination, the fixed-focus lens of the present embodiment can better correct the aberration within the spectral bandwidth by combining with fig. 5, so as to increase the sharpness of the real-shot image of the lens; fig. 6 shows that the curvature of field and the distortion can be corrected to a suitable range, so that the resolution in the meridian direction can be close to that in the sagittal direction, and the resolution of the lens is uniform.
Third embodiment:
referring to fig. 7, the stop STO in the present embodiment is located between the first lens L1 and the second lens L2, and the first lens L1, the fourth lens L4, and the fifth lens L5 are aspheric lenses. Wherein, the focal length is: 7.8mm, FNO:1.53, total length: 22.5 mm.
The parameters relating to each lens in the present embodiment include surface type, radius of curvature, k value, thickness, refractive index, and abbe number, and are shown in table 8:
| surface number | Surface type | Radius of curvature | Thickness of | Refractive index | Abbe number |
| 1 | Aspherical surface | 2.627 | 1.145 | 1.597 | 68.4 |
| 2 | Aspherical surface | 1.871 | 2.94 | ||
| 3(STO) | Spherical surface | Infinity | 1.369 | ||
| 4 | Spherical surface | -3.751 | 1.581 | 1.597 | 31.04 |
| 5 | Spherical surface | -4.055 | 0.265 | ||
| 6 | Spherical surface | 7.307 | 3.132 | 1.474 | 89.94 |
| 7 | Spherical surface | -8.164 | 0.121 | ||
| 8 | Aspherical surface | -36.137 | 1.347 | 1.607 | 35.83 |
| 9 | Aspherical surface | 3.771 | 0.294 | ||
| 10 | Aspherical surface | 4.290 | 3.239 | 1.545 | 57.85 |
| 11 | Aspherical surface | -8.049 | 6.067 | ||
| 12 | Spherical surface | Infinity | 0.80 | 1.517 | 64.21 |
| 13 | Spherical surface | Infinity | 0.2 | ||
| Image plane | Spherical surface | Infinity | - |
TABLE 8
The K value and aspherical surface coefficient of this embodiment are shown in tables 9 and 10 below:
TABLE 9
| Surface number | a12 | a14 |
| 1 | -6.27660E-008 | 1.21230E-010 |
| 2 | -4.08135E-007 | 2.64011E-011 |
| 8 | -1.55344E-008 | 1.43125E-008 |
| 9 | -6.78340E-007 | 2.87874E-008 |
| 10 | 2.64851E-007 | -1.06835E-009 |
| 11 | -5.44938E-008 | 4.51668E-009 |
As can be seen from fig. 8 and 9 in combination, the fixed-focus lens of the present embodiment can better correct the aberration within the spectral bandwidth by combining with fig. 8, so as to increase the sharpness of the real-time photographed image of the lens; fig. 9 shows that the curvature of field and the distortion can be corrected to a suitable range, so that the resolution in the meridian direction can be close to that in the sagittal direction, and the resolution of the lens is uniform.
Fourth embodiment:
referring to fig. 10, the stop STO in the present embodiment is located between the first lens L1 and the second lens L2, and the first lens L1, the second lens L2, the fourth lens L4, and the fifth lens L5 are aspheric lenses. Wherein, the focal length is: 7.78mm, FNO:1.57, total length: 22.5 mm.
The parameters relating to each lens in the present embodiment include surface type, radius of curvature, k value, thickness, refractive index, and abbe number, and are shown in table 11:
| surface number | Surface type | Radius of curvature | Thickness of | Refractive index | Abbe number |
| 1 | Aspherical surface | 2.568 | 1.115 | 1.547 | 54.32 |
| 2 | Aspherical surface | 1.791 | 3.264 | ||
| 3(STO) | Spherical surface | Infinity | 1.323 | ||
| 4 | Aspherical surface | -4.041 | 1.681 | 1.637 | 25.17 |
| 5 | Aspherical surface | -3.450 | 0.243 | ||
| 6 | Spherical surface | 8.310 | 3.078 | 1.485 | 82.97 |
| 7 | Spherical surface | -8.069 | 0.14 | ||
| 8 | Aspherical surface | -33.662 | 0.597 | 1.640 | 22.878 |
| 9 | Aspherical surface | 3.532 | 0.686 | ||
| 10 | Aspherical surface | 5.089 | 3.351 | 1.538 | 48.22 |
| 11 | Aspherical surface | -7.894 | 6.022 | ||
| 12 | Spherical surface | Infinity | 0.80 | 1.517 | 64.2 |
| 13 | Spherical surface | Infinity | 0.20 | ||
| Image plane | Spherical surface | Infinity | - |
TABLE 11
The K value and aspherical surface coefficient of this embodiment are shown in tables 12 and 13 below:
TABLE 12
| Surface number | a12 | a14 |
| 1 | -2.08811E-008 | -6.75443E-011 |
| 2 | -4.55921E-007 | 4.30398E-009 |
| 4 | -1.07433E-007 | -4.59649E-009 |
| 5 | -2.47149E-008 | -3.75587E-010 |
| 8 | -6.59045E-009 | 1.28133E-008 |
| 9 | -7.19470E-007 | 2.75872E-008 |
| 10 | 2.77715E-007 | -2.99212E-009 |
| 11 | -5.16489E-008 | 4.30589E-009 |
Watch 13
As can be seen from fig. 11 and 12 in combination, the fixed-focus lens of the present embodiment can better correct the aberration within the spectral bandwidth by combining with fig. 11, so as to increase the sharpness of the real shot image of the lens; fig. 12 shows that the curvature of field and the distortion can be corrected to a suitable range, so that the resolution in the meridional direction can be close to that in the sagittal direction, and the resolution of the lens can be uniform.
The above description is only one embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (14)
1. A fixed focus lens comprising, arranged in order from an object side to an image side along an optical axis: a first lens (L1) having a negative optical power, a second lens (L2) having a positive optical power, a third lens (L3) having a positive optical power, a fourth lens (L4) having a negative optical power, and a fifth lens (L5) having a positive optical power.
2. The prime lens according to claim 1, further comprising a Stop (STO) between the first lens (L1) and the second lens (L2) or between the second lens (L2) and the third lens (L3).
3. The prime lens according to claim 1, wherein the first lens (L1) is a convex-concave lens, the second lens (L2) is a concave-convex lens, the third lens (L3) is a biconvex lens, the fourth lens (L4) is a biconcave lens, and the fifth lens (L5) is a biconvex lens.
4. The prime lens according to claim 1, wherein the first lens (L1), the fourth lens (L4) and the fifth lens (L5) are plastic aspheric lenses, the third lens (L3) is a glass lens, and the second lens (L2) is a plastic aspheric lens or a glass lens.
5. The prime lens according to any of claims 1 to 4, wherein the first lens (L1) has a saggital height SAG11 of the maximum optically effective diameter of the object side and its radius of curvature R1, and the first lens (L1) has a saggital height SAG12 of the maximum optically effective diameter of the image side and its radius of curvature R2, respectively, satisfying the following relationships:
1.0≤R1/SAG11≤1.5；
0.5≤R2/SAG12≤1.0。
6. the prime lens according to any of claims 1 to 4, wherein the radius of curvature R21 of the object-side surface of the second lens (L2) and the radius of curvature R12 of the image-side surface of the first lens (L1) satisfy the following relation:
-2.5≤R21/R12≤-1.5。
7. a fixed focus lens as claimed in any one of claims 1 to 4, wherein the Chief Ray Angle (CRA) of the maximum field of view of the fixed focus lens satisfies the following condition: CRA is less than or equal to 12 degrees.
8. The fixed focus lens according to claim 2, wherein an optical power Φ 3 of the third lens (L3) and an optical power Φ II of a lens group located on the image side of the Stop (STO) satisfy the following relational expression:
0.7≤φ3/φII≤1.3。
9. the prime lens according to claim 2, wherein the distance M1 between the center on the object side of the first lens (L1) and the Stop (STO), the distance M2 between the center on the image side of the fifth lens (L5) and the Stop (STO), and the total optical length TTL of the prime lens satisfy the following relationships, respectively:
0.15≤M1/TTL≤0.32；
0.33≤M2/TTL≤0.51。
10. the prime lens according to any one of claims 1 to 4, wherein the following relationships are satisfied between the focal length of the first lens (L1) being f1, the focal length of the second lens (L2) being f2, the focal length of the third lens (L3) being f3, the focal length of the fourth lens (L4) being f4, the focal length of the fifth lens (L5) being f5, and the effective focal length f of the prime lens, respectively:
-4.2≤f1/f≤-2.5；
2≤f2/f≤12；
1≤f3/f≤1.5；
-0.9≤f4/f≤-0.5；
0.5≤f5/f≤0.9。
11. a prime lens according to claim 2, wherein the lens group on the image side of the Stop (STO) comprises at least one glass lens of low-abbe material with abbe number Vd > 75.
12. The prime lens according to any one of claims 1 to 4, wherein the focal length f4 of the fourth lens (L4) and the focal length f5 of the fifth lens (L5) satisfy the following relation:
-1.1≤f4/f5≤-0.6。
13. the prime lens according to any one of claims 1 to 4, wherein the total optical length TTL and the aperture FNO of the prime lens satisfy the following conditions: TTL is less than or equal to 22.5mm, and FNO is less than or equal to 1.6.
14. The fixed focus lens as claimed in any one of claims 1 to 4, wherein the total optical length TTL and the effective focal length f of the fixed focus lens satisfy the following relation:
TTL/f≤3.0。
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| CN202120567172.2U CN214845994U (en) | 2021-03-19 | 2021-03-19 | Fixed focus lens |
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| CN202120567172.2U CN214845994U (en) | 2021-03-19 | 2021-03-19 | Fixed focus lens |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114397746A (en) * | 2022-01-22 | 2022-04-26 | 深圳融合光学科技有限公司 | Day and night dual-purpose prime lens and imaging method thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114397746A (en) * | 2022-01-22 | 2022-04-26 | 深圳融合光学科技有限公司 | Day and night dual-purpose prime lens and imaging method thereof |
| CN114397746B (en) * | 2022-01-22 | 2023-11-24 | 福建福光天瞳光学有限公司 | Day and night fixed focus lens and imaging method thereof |
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