Lens structure and large-light-transmission athermalization under-wing lens
By designing a lens structure with multiple lens combination, the problems of poor performance and insufficient light transmission of the lens on the aircraft at high and low temperatures are solved, and high definition image output and high reliability in high altitude environments are achieved, which meets the needs of complex high altitude environments. .
Patent Information
- Application Number
- CN202421203382.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-05-29
AI Technical Summary
When used on aircraft, the existing lenses have poor performance at high and low temperatures, low light transmission, low energy utilization, low edge brightness, and insufficient reliability, which cannot meet the needs of complex environments at high altitudes.
A lens structure is designed, consisting of multiple lenses, including convex and concave lenses, adopting a thermally-free design and surface support method, using specific glass materials to correct temperature drifts, and by reasonably distributing the power and refractive index. Improve stability and light transmission.
It realizes the output of high-definition images at an operating temperature of -55℃ to 100℃, with large light passes, good low light effects, uniform brightness from center to edge, high color reduction, and can work stably under huge vibration and high altitude temperature impact.
Smart Images
Figure CN222354126U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of underwing lenses, and in particular to a lens structure and a high-throughput athermal underwing lens. Background Art
[0002] Existing lenses are used more and more widely on aircraft, and the requirements for the operating environment of lenses are getting higher and higher. Currently, the performance of lenses is poor under high and low temperatures, and they are easily out of focus at high and low temperatures; the lenses currently used for monitoring on aircraft have low light transmittance, low energy utilization, and low edge brightness; and the lenses used for monitoring on aircraft have low reliability requirements and cannot meet the complex environment at high altitudes; lenses used for monitoring on aircraft are prone to blue-purple fringing and poor color reproduction. Utility Model Content
[0003] The purpose of the utility model is to solve the above-mentioned problems and provide a lens structure and a high-throughput athermal underwing lens.
[0004] The technical solution of the present disclosure is achieved as follows:
[0005] In a first aspect, the present disclosure provides a lens structure, wherein the lens comprises the following lenses in order from the object side to the image side:
[0006] A first lens, wherein the object side surface of the first lens is convex, and the image side surface of the first lens is concave;
[0007] A second lens, wherein the second lens has a negative refractive power, and the object side surface of the second lens is convex, and the image side surface of the second lens is concave;
[0008] A third lens, wherein the third lens has a negative refractive power; and the object side surface of the third lens is a concave surface;
[0009] a fourth lens having positive refractive power;
[0010] a fifth lens having positive refractive power, an object-side surface of the fifth lens being convex, and an image-side surface of the fifth lens being convex;
[0011] a sixth lens having a positive refractive power, an object-side surface of the sixth lens being a convex surface, and an image-side surface of the sixth lens being a convex surface;
[0012] a seventh lens having positive refractive power, and an image-side surface of the seventh lens being a convex surface;
[0013] an eighth lens having positive refractive power, an object-side surface of the eighth lens being concave, and an image-side surface of the eighth lens being concave;
[0014] A ninth lens has positive refractive power, an object side surface of the ninth lens is convex, and an image side surface is convex.
[0015] The advantages or beneficial effects of the above technical solution include at least:
[0016] 1. The lens of this solution takes into account the temperature changes of the aircraft at high altitudes, has a non-thermal design, meets the operating temperature requirements of -55℃ to 100℃, and outputs high-definition images;
[0017] 2. The lens of this solution has a large light transmission, an aperture of Fno1.4, good low-light effect, high relative illumination, and uniform brightness from the center to the edge of the field of view;
[0018] 3. The lens of this scheme takes into account the huge vibration of aircraft operation and the high-altitude temperature shock. The design adopts the surface support method and there is no glued lens to ensure that there is no risk of debonding and glue failure under huge temperature shock;
[0019] 4. The lens of this solution has high color reproduction, small color difference, and delicate monitoring images.
[0020] In a second aspect, the present disclosure further provides a high-throughput athermal under-wing lens, wherein the lens adopts any one of the above-mentioned lens structures.
[0021] The advantages or beneficial effects of the above technical solution include at least:
[0022] The beneficial effects of this lens have been explained clearly above and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings illustrate exemplary embodiments of the present disclosure of embodiments of the utility model and, together with the description, are used to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure, and the accompanying drawings are included in and constitute a part of this specification.
[0024] Figure 1 A schematic diagram of the optical structure diagram of Example 1 is shown;
[0025] Figure 2 A schematic diagram of the optical structure diagram of Example 2 is shown;
[0026] Figure 3 A schematic diagram of an optical structure diagram of Example 3 is shown;
[0027] Figure 4 The off-axis chromatic aberration curve of Example 1 is shown;
[0028] Figure 5 The relative illumination curve of Example 1 is shown;
[0029] Figure 6 The focusing curve of Example 1 at a low temperature of -55°C is shown;
[0030] Figure 7The focusing curve of Example 1 at room temperature 25°C is shown;
[0031] Figure 8 The focusing curve of Example 1 at a high temperature of 100°C is shown;
[0032] Fig. 9 The off-axis chromatic aberration curve of Example 2 is shown;
[0033] Fig.10 The relative illumination curve of Example 2 is shown;
[0034] Fig.11 The focusing curve of Example 2 at a low temperature of -55°C is shown;
[0035] Fig.12 The focusing curve of Example 2 at room temperature 25°C is shown;
[0036] Fig.13 The focusing curve of Example 2 at a high temperature of 100°C is shown;
[0037] Fig.14 The off-axis chromatic aberration curve of Example 3 is shown;
[0038] Fig.15 The relative illumination curve of Example 3 is shown;
[0039] Fig.16 The focusing curve of Example 3 at low temperature -55°C is shown.
[0040] Fig.17 The focusing curve of Example 3 at room temperature 25°C is shown.
[0041] Fig.18 The focusing curve of Example 3 at a high temperature of 100°C is shown;
[0042] Reference numerals: 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens. DETAILED DESCRIPTION
[0043] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.
[0044] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0045] It should be understood that the term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc. mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.
[0046] The names of the messages or information exchanged between multiple devices in the embodiments of the present disclosure are only used for illustrative purposes and are not used to limit the scope of these messages or information.
[0047] Reference Figure 1 , Figure 2 and Figure 3 , a lens structure, the lens comprises the following lenses in order from the object side to the image side:
[0048] A first lens 1, wherein the object side surface of the first lens 1 is convex, and the image side surface of the first lens 1 is concave; a second lens 2, wherein the second lens 2 has negative refractive power, and the object side surface of the second lens 2 is convex, and the image side surface is concave; a third lens 3, wherein the third lens 3 has negative refractive power, and the object side surface of the third lens 3 is concave; a fourth lens 4, wherein the fourth lens 4 has positive refractive power; a fifth lens 5, wherein the fifth lens 5 has positive refractive power, and the object side surface of the fifth lens 5 is convex, and the image side surface is convex; a sixth lens 6, wherein the sixth lens 6 has positive refractive power, and the object side surface of the sixth lens 6 is convex, and the image side surface is convex; a seventh lens 7, wherein the seventh lens 7 has positive refractive power, and the image side surface of the seventh lens 7 is convex; an eighth lens 8, wherein the eighth lens 8 has positive refractive power, and the object side surface of the eighth lens 8 is concave, and the image side surface is concave; a ninth lens 9, wherein the ninth lens 9 has positive refractive power, and the object side surface of the ninth lens 9 is convex, and the image side surface is convex.
[0049] Based on the above, the glass material of the sixth lens 6 is selected as a material with a negative relative refractive index temperature coefficient Dn / dt. With its positive optical power, it can correct the temperature drift and achieve athermal design. The glass material of the seventh lens 7 needs to meet the requirement of a material with a negative relative refractive index temperature coefficient Dn / dt. The eighth lens 8 needs to meet the requirement of a material with a positive relative refractive index temperature coefficient Dn / dt. The combination of materials is used to correct the temperature drift and achieve athermal design.
[0050] Further, the lens satisfies the following relationship: 1.5 < fa / fb < 2.5; where fa is the focal length of the front lens group composed of the first lens 1 to the fifth lens 5, and fb is the focal length of the rear lens group composed of the sixth lens 6 to the ninth lens 9. By reasonably distributing the optical power, the structural stability of the front and rear groups is high.
[0051] Further, the lens structure also satisfies the following relationship: nd4 > 1.8; where nd4 is the refractive index of the fourth lens 4. The fourth lens 4 uses a high refractive index, which can reduce the outer diameter of the lens, make the edge thickness larger, and is beneficial to the vibration and temperature shock reliability.
[0052] As a further improvement of the above, the lens structure satisfies the following relationship: nd9 > 1.8; where nd9 is the refractive index of the ninth lens 9. The ninth lens 9 uses a high refractive index, which makes the light transition smoothly to the image plane and is beneficial to improving the resolution.
[0053] As a further improvement of the above, the lens structure satisfies the following relationship: 0.7 < T9 / BFL < 1.5, where T9 is the central thickness of the ninth lens and BFL is the optical back focal length of the lens; this is beneficial to structural stability, shock resistance and vibration resistance.
[0054] And the lens structure leaves enough margin in design and adopts the surface support method to make the lens more stable.
[0055] The radii, thicknesses, refractive indices, Abbe numbers and focal lengths of the nine lenses of the lens structure of the present utility model all have three embodiments:
[0056] In the first embodiment, as shown in Table 1:
[0057]
[0058] Table 1
[0059] Figure 4This is the off-axis chromatic aberration curve of Example 1, the horizontal axis represents the chromatic aberration value of different wavelengths, and the vertical axis represents the size of the field of view; it can be seen from the figure that the wavelength ranges from 435nm to 650nm, the chromatic aberration value is 3.2um, and the chromatic aberration curves of different wavelengths intersect with each other, so that the system has an achromatic effect and high color reproduction.
[0060] Figure 5 This is the relative illumination curve of Example 1. The horizontal axis represents different fields of view, and the vertical axis represents the relative illumination size. It can be seen from the figure that the curve is relatively flat, and the RI at the edge of the field of view is greater than 85%. The system has a large light transmission, which makes the system have a good low-light effect, high brightness from the center to the edge, and uniform.
[0061] Figures 6 to 8 It is the focusing curve of low temperature -55℃ / normal temperature 25℃ / high temperature 100℃ of Example 1, the horizontal axis represents the focusing position, and the vertical axis represents the MTF value. It can be seen from the figure that at different temperatures, the difference in focusing curves is less than 3um, the focusing position is almost unchanged, and the MTF value does not decrease compared to normal temperature. The non-thermal design enables the system to output high-definition images without loss of focus at operating temperatures of -55℃ to 100℃.
[0062] In the second embodiment, as shown in Table 2:
[0063]
[0064] Table 2
[0065] Fig. 9 This is the off-axis chromatic aberration curve of Example 2, where the horizontal axis represents the chromatic aberration value of different wavelengths, and the vertical axis represents the size of the field of view; as can be seen from the figure, the wavelength ranges from 435nm to 650nm, the chromatic aberration value is 2.1um, and the chromatic aberration curves of different wavelengths intersect with each other, so that the system has an achromatic effect and high color reproduction.
[0066] Fig.10 This is the relative illumination curve of Example 2, where the horizontal axis represents different fields of view, and the vertical axis represents the relative illumination size. It can be seen from the figure that the curve is relatively flat, and the RI is greater than 87% at the edge of the field of view. The system has a large light transmittance, which makes the system have good low-light effect, high and uniform brightness from the center to the edge.
[0067] Figure 11 to Figure 13 It is the focusing curve of low temperature -55℃ / normal temperature 25℃ / high temperature 100℃ of Example 2, the horizontal axis represents the focusing position, and the vertical axis represents the MTF value. It can be seen from the figure that at different temperatures, the difference in focusing curves is less than 3um, the focusing position is almost unchanged, and the MTF value does not decrease compared to normal temperature. The non-thermal design enables the system to output high-definition images without loss of focus at operating temperatures of -55℃ to 100℃.
[0068] In the third embodiment, as shown in Table 3:
[0069]
[0070] Table 3
[0071] Fig.14 This is the off-axis chromatic aberration curve of Example 3, where the horizontal axis represents the chromatic aberration value of different wavelengths, and the vertical axis represents the size of the field of view. It can be seen from the figure that the wavelength ranges from 435nm to 650nm, the chromatic aberration value is 2.5um, and the chromatic aberration curves of different wavelengths intersect with each other, so that the system has an achromatic effect and high color reproduction.
[0072] Fig.15 This is the relative illumination curve of Example 3, where the horizontal axis represents different fields of view, and the vertical axis represents the relative illumination size. It can be seen from the figure that the curve is relatively flat, and the RI is greater than 83% at the edge of the field of view. The system has a large light transmittance, which makes the system have good low-light effect, high and uniform brightness from the center to the edge.
[0073] Figure 16 to Figure 18 The focusing curves of Example 3 at low temperature of -55°C / normal temperature of 25°C / high temperature of 100°C, the horizontal axis represents the focusing position, and the vertical axis represents the MTF value. It can be seen from the figure that at different temperatures, the difference in the focusing curves is less than 3um, the focusing position is almost unchanged, and the MTF value does not decrease compared to normal temperature. The non-thermal design enables the system to output high-definition images without loss of focus at operating temperatures of -55°C to 100°C.
[0074] An embodiment of the utility model also provides a large-light-through athermal under-wing lens, characterized in that: the lens adopts a lens structure as described in any of the above-mentioned ones. The implementation effect of this embodiment is consistent with the implementation effect of the above-mentioned lens structure and will not be repeated here.
[0075] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.
Claims
1. A lens structure, characterized in that: The lens includes the following lenses in order from the object side to the image side: A first lens (1), wherein the object side surface of the first lens (1) is a convex surface, and the image side surface of the first lens (1) is a concave surface; A second lens (2), wherein the second lens (2) has a negative refractive power, and the object side surface of the second lens (2) is a convex surface, and the image side surface is a concave surface; A third lens (3), the third lens (3) having a negative refractive power; the object side surface of the third lens (3) being a concave surface; a fourth lens (4), wherein the fourth lens (4) has a positive refractive power; a fifth lens (5), the fifth lens (5) having a positive refractive power, the object side surface of the fifth lens (5) being a convex surface, and the image side surface being a convex surface; a sixth lens (6), the sixth lens (6) having a positive refractive power, the object side surface of the sixth lens (6) being a convex surface, and the image side surface being a convex surface; A seventh lens (7), the seventh lens (7) having positive refractive power, and the image side surface of the seventh lens (7) being a convex surface; an eighth lens (8), the eighth lens (8) having a positive refractive power, the object side surface of the eighth lens (8) being a concave surface, and the image side surface being a concave surface; A ninth lens (9), the ninth lens (9) has a positive refractive power, the object side surface of the ninth lens (9) is a convex surface, and the image side surface is a convex surface.
2. The lens structure according to claim 1, characterized in that: The glass material of the sixth lens (6) is selected to be a material with a negative relative refractive index temperature coefficient Dn / dt; The glass material of the seventh lens (7) needs to be a material that satisfies the requirement that the relative refractive index temperature coefficient Dn / dt is a negative value; The eighth lens (8) needs to be made of a material satisfying that the relative refractive index temperature coefficient Dn / dt is a positive value.
3. The lens structure according to claim 1, characterized in that: The lens satisfies the following relationship: 1.5<fa / fb<2.5; Wherein, fa is the focal length of the front lens group composed of the first lens (1) to the fifth lens (5); Wherein, fb is the focal length of the rear lens group composed of the sixth lens (6) to the ninth lens (9).
4. The lens structure according to claim 1, characterized in that: The lens structure also satisfies the following relationship: nd4>1.8; wherein nd4 is the refractive index of the fourth lens (4).
5. The lens structure according to claim 1, characterized in that: The lens structure satisfies the following relationship: nd9>1.8; Wherein nd9 is the refractive index of the ninth lens (9).
6. The lens structure according to claim 1, characterized in that: The lens structure satisfies the following relationship: 0.7 <T9 / BFL<1.5; Wherein, T9 is the center thickness of the ninth lens (9), and BFL is the optical back focus of the lens.
7. A high-throughput athermal underwing lens, characterized by: The lens adopts the lens structure as claimed in any one of claims 1-6.