Folding and super hybrid lens for partitioned color temperature test

Abstract

The utility model relates to a refraction and super hybrid lens for a partitioned color temperature test, which belongs to the technical field of optical devices and comprises a diaphragm, a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from an object plane to an image plane along an optical axis, wherein at least one of the first lens, the second lens, the third lens and the fourth lens is a metasurface lens. The folding and super hybrid lens can test the color temperatures of a plurality of areas of an object at the same time, and has higher test efficiency compared with a common single-point or small-area color temperature tester.

Description

Technical Field

[0001] This application belongs to the field of optical devices, and particularly relates to a catadioptric hybrid lens for zonal color temperature measurement. Background Art

[0002] With the continuous improvement of people's requirements for lighting quality and color performance, the accurate measurement of the color temperature of light sources has become increasingly important. Traditional global color temperature measurement methods may not be able to capture the true color temperature of local light sources within a specific area. Therefore, the emergence of zonal color temperature measurement technology has filled this gap. By measuring the color temperature in zones, we can more precisely understand the color temperature differences of light sources in different areas, and adjust the lighting scheme or photographic parameters accordingly to achieve more accurate color performance.

[0003] However, although zonal color temperature measurement technology has significant advantages in improving the accuracy of color performance, there are also some limitations. For example, current color temperature meters use long-focus lenses or optical sensors to receive light signals, which results in a small measurement range and a large size, limiting their application in certain scenarios. In addition, when performing global color temperature measurement, it is necessary to repeatedly measure the color temperature of each zone, resulting in low efficiency, especially in large-scale lighting environments.

[0004] To overcome these challenges, future development directions may include optimizing the design of color temperature meters to make them more compact, portable, and capable of achieving a wider measurement range. Summary of the Utility Model

[0005] This application provides a catadioptric hybrid lens for zonal color temperature measurement to at least solve the above technical problems existing in the prior art.

[0006] An embodiment of this application provides a catadioptric hybrid lens for zonal color temperature measurement, the

[0007] In an implementable manner, it includes a diaphragm, a first lens, a second lens, a third lens, and a fourth lens sequentially arranged along the optical axis from the object plane to the image plane;

[0008] Among them, at least one of the first lens, the second lens, the third lens, and the fourth lens is a metasurface lens.

[0009] In an implementable manner, the catadioptric hybrid lens satisfies:

[0010]

[0011] Among them, Y d is the maximum image height of the catadioptric hybrid long-wave infrared lens, Fno is the f-number, EFL is the focal length, and FOV is the diagonal field of view.

[0012] In an implementable embodiment, the field of view angle of the refractive - diffractive hybrid lens satisfies FOV≥90°, the size of the imaging area satisfies 0<Y≤Y d , and the working wavelength range is the entire visible light range.

[0013] In an implementable embodiment, the aperture stop is the aperture diaphragm, and its aperture size satisfies 1.5≤D*Fno≤1.6.

[0014] In an implementable embodiment, the first lens and the second lens are spherical lenses, the third lens is an aspherical lens, and the fourth lens is a metasurface lens.

[0015] In an implementable embodiment, the first lens is a positive lens with positive optical power. Both the object side and the image side of the first lens are spherical surfaces; its object side is a convex surface, and the radius of curvature satisfies: 0.7≤R1≤0.8; the image side is a concave surface, and the radius of curvature satisfies: 1.8≤R2≤1.9; the thickness satisfies: (R1 + R2) / T1=13.

[0016] In an implementable embodiment, the second lens is a lens with positive optical power. Both its object side and image side are spherical surfaces; the distance between the second lens and the first lens satisfies: 0.2mm≤T2≤0.3mm; the radius of curvature of its object side satisfies 1.5≤R3≤1.7; the radius of curvature of its image side satisfies - 1.1≤R4≤ - 0.9; the thickness satisfies: (R3 + R4) / T3=3.5.

[0017] In an implementable embodiment, both the object side and the image side of the third lens are aspherical surfaces; the distance between the third lens and the second lens satisfies: 0.19mm≤T4≤0.21mm; the radius of curvature of its object side satisfies: - 0.2≤R4≤ - 0.3; the radius of curvature of the image side satisfies: - 0.5≤R5≤ - 0.6.

[0018] In an implementable embodiment, the object side of the metasurface lens is a plane, and the image side is a micro - structured surface; the distance between the metasurface lens and the fourth lens satisfies: 0.4mm≤T5≤0.5mm.

[0019] In an implementable embodiment, the thickness of the metasurface lens is one of 0.21mm, 0.5mm, 0.7mm, and 1.1mm.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1. The refractive - diffractive hybrid lens of the present application can simultaneously measure the color temperature of multiple regions of an object. Compared with the commonly used single - point or small - area color temperature testers, it has higher testing efficiency;

[0022] 2. The refractive-diffractive hybrid lens of the present application uses a metasurface to replace the refractive lens, effectively reducing the volume of the optical system. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of the refractive-diffractive hybrid lens in an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of the phase distribution of the metasurface lens in an embodiment of the present application;

[0025] Figure 3 is the spot diagram of the refractive-diffractive hybrid lens in an embodiment of the present application;

[0026] Figure 4 is the ray trace diagram of the refractive-diffractive hybrid lens in an embodiment of the present application. Detailed Description of the Embodiments

[0027] The present application will be further described in detail below with reference to the drawings.

[0028] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0029] The present application discloses a refractive-diffractive hybrid lens for zonal color temperature testing, including a diaphragm, a first lens, a second lens, a third lens, and a fourth lens arranged in sequence along the optical axis from the object plane to the image plane. Among them, at least one of the first lens, the second lens, the third lens, and the fourth lens is a metasurface lens.

[0030] Any of the above refractive-diffractive hybrid lenses satisfies the following formula:

[0031]

[0032] where Y d is the maximum image height of the refractive-diffractive long-wave infrared lens, Fno is the f-number, EFL is the focal length, and FOV is the diagonal field of view.

[0033] The field of view of the refractive-diffractive hybrid lens satisfies: FOV ≥ 90°, and the size of the imaging area of the refractive-diffractive hybrid lens satisfies 0 < Y ≤ Y d, the working wavelength band of the refractive-diffractive hybrid lens covers the entire visible light range. The refractive-diffractive hybrid lens can integrate light at different angles into light spots with consistent root mean square radii in different regions of the image plane. The light spots in different regions of the image plane are used for the back-end algorithm to calculate the color temperature of each region of the object plane. The aperture stop is the aperture diaphragm, which is located in front of the first lens, and its aperture size satisfies: 1.5 ≤ D*Fno ≤ 1.6.

[0034] Taking only the fourth lens as the metasurface lens as an example, the first and second lenses are spherical lenses, the third lens is an aspherical lens, and the fourth lens is a metasurface lens.

[0035] The first lens is a positive lens with positive optical power. Both the object side and the image side of the first lens are spherical surfaces; its object side is a convex surface, and the radius of curvature satisfies: 0.7 ≤ R1 ≤ 0.8; its image side is a concave surface, and the radius of curvature satisfies: 1.8 ≤ R2 ≤ 1.9; the thickness satisfies: (R1 + R2) / T1 = 13.

[0036] The second lens is located between the first lens and the third lens, and its interval from the first lens satisfies: 0.2 mm ≤ T2 ≤ 0.3 mm; the second lens is a lens with positive optical power, and both its object side and image side are spherical surfaces; the radius of curvature of its object side satisfies 1.5 ≤ R3 ≤ 1.7; the radius of curvature of its image side satisfies -1.1 ≤ R4 ≤ -0.9; the thickness satisfies: (R3 + R4) / T3 = 3.5.

[0037] The third lens is located between the second lens and the fourth lens, and both its object side and image side are aspherical surfaces; its interval from the second lens satisfies: 0.19 mm ≤ T4 ≤ 0.21 mm. The radius of curvature of its object side satisfies: -0.2 ≤ R4 ≤ -0.3, and the radius of curvature of its image side satisfies: -0.5 ≤ R5 ≤ -0.6.

[0038] The metasurface lens is located behind the third lens and in front of the image plane, and its interval from the fourth lens satisfies: 0.4 mm ≤ T5 ≤ 0.5 mm; its object side is a plane, and its image side is a microstructured surface. Optionally, the thickness of the metasurface lens can be 0.21 mm, 0.5 mm, 0.7 mm, or 1.1 mm.

[0039] The materials of the first lens, the second lens, and the third lens can be glass or plastic. The fourth lens is composed of two parts, namely a glass substrate and a microstructured array; the material of the glass substrate is glass, and the microstructured array is specifically a micro-nano pillar array, and the micro-nano pillar array can be in a square distribution or a hexagonal distribution. The material of the nano pillars can be titanium dioxide or gallium nitride.

[0040] As Figure 1 shown, the incident light enters through the aperture stop 1, and after being modulated by the first lens 2, the second lens 3, the third lens 4, and the fourth lens 5, it finally irradiates on the image plane 6.

[0041] Exemplarily, Table 1 details the specific optical data parameters of each lens in the refractive-diffractive hybrid lens provided by the present invention in a feasible implementation manner. The optical data parameters in Table 1 correspond to Figure 1 the refractive-diffractive hybrid lens shown.

[0042] Table 1

[0043]

[0044] For the aspheric surfaces in Table 1, the aspheric surface equation is:

[0045]

[0046] where Z is the distance from the corresponding point on the aspheric surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspheric surface to the optical axis, c represents the curvature of the surface at the vertex, K represents the conic constant, and A4, A6, A8, A10, A12, A14, A16

[0047] respectively represent the aspheric coefficients of the corresponding orders of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th orders.

[0048] In the embodiments of the present application, the conic constant K and the aspheric coefficients corresponding to the surfaces of the aspheric surfaces are shown in Table 2:

[0049] Table 2

[0050] Surface number K A4 A6 A8 A10 A12 A14 A16 S5 -349.000 -0.444 -3.272 -4.375 -2.137 -38.702 -268.8666 -1495.588 S6 -42.573 -0.114 -0.544 -1.235 -2.346 -3.438 -2.477 10.839

[0051] In the embodiments of the present application, the phase distribution of the binary surface is the phase distribution of the diffractive lens, and the nano-pillar array is used to implement this phase.

[0052] The equation satisfied by this phase distribution is:

[0053] φ = a 1 r 2 + a 2 r 4 + a 3 r 6 + a 4 r 8 + a 5 r 10

[0054] The polynomial coefficients of this binary surface are shown in Table 3:

[0055] Table 3

[0056] Surface serial number R1 a1 a2 a3 a4 a5 S8 1 125.594 -0.160 -0.859 1.720 2.459

[0057] Where R1 is the normalized radius. All the light intercept points are divided by this number to determine the x and y coordinates for polynomial evaluation. a1, a2, a3, a4, and a5 are the polynomial coefficients corresponding to the 2nd order, 4th order, 6th order, 8th order, and 10th order respectively.

[0058] Figure 2 is the phase distribution of the metasurface lens in the embodiment of the present invention, Figure 3 is the spot diagram of the embodiment of the present invention, and the root mean square radius is about 0.39 mm. Figure 4 is the light trace diagram of the embodiment of the present invention. The light at each angle partially overlaps, which is convenient for the later algorithm to calculate the color temperature.

[0059] The above is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present disclosure, and all of them should be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A hybrid lens for zoned color temperature testing, characterized by: It includes an aperture, a first lens, a second lens, a third lens, and a fourth lens which are sequentially arranged along the optical axis from the object plane to the image plane; Among them, at least one of the first lens, the second lens, the third lens, and the fourth lens is a metasurface lens.

2. The hybrid lens according to claim 1, characterized in that: The hybrid lens meets the following requirements: Among them, Y d is the maximum image height of the super hybrid long-wave infrared lens, Fno is the aperture number, EFL is the focal length, and FOV is the diagonal field of view.

3. The hybrid lens according to claim 1, characterized in that: The field of view of the hybrid lens satisfies FOV≥90°, and the imaging area size satisfies 0<Y≤Y d , the working band is the entire visible light range.

4. The hybrid lens according to claim 1, characterized in that: The diaphragm is an aperture diaphragm, and its aperture size satisfies 1.5≤D*Fno≤1.

6.

5. The hybrid lens according to claim 1, characterized in that: The first lens and the second lens are spherical lenses, the third lens is an aspherical lens, and the fourth lens is a hypersurface lens.

6. The hybrid lens according to claim 5, characterized in that: The first lens is a positive lens with positive refractive power, and both the object side surface and the image side surface of the first lens are spherical surfaces; The object side surface is convex, and the radius of curvature satisfies: 0.7≤R1≤0.8; The image side surface is concave, and the radius of curvature satisfies: 1.8≤R2≤1.9; The thickness satisfies: (R1+R2) / T1=13.

7. The hybrid lens according to claim 5, characterized in that: The second lens is a lens with positive refractive power, and both the object side surface and the image side surface thereof are spherical surfaces; The distance between the second lens and the first lens satisfies: 0.2mm≤T2≤0.3mm; the radius of curvature of the object side surface satisfies: 1.5≤R3≤1.7; The image side curvature radius satisfies -1.1≤R4≤-0.9; The thickness satisfies: (R3+R4) / T3=3.

5.

8. The hybrid lens according to claim 5, characterized in that: The object side surface and the image side surface of the third lens are both aspherical surfaces; The distance between the third lens and the second lens satisfies: 0.19mm≤T4≤0.21mm; The radius of curvature of the object side surface satisfies: -0.2≤R4≤-0.3; The image side curvature radius satisfies: -0.5≤R5≤-0.

6.

9. The hybrid lens according to claim 5, characterized in that: The object side of the metasurface lens is a plane, and the image side is a microstructured surface; The distance between the metasurface lens and the fourth lens satisfies: 0.4mm≤T5≤0.5mm.

10. The hybrid lens according to claim 9, characterized in that: The thickness of the metasurface lens is one of 0.21 mm, 0.5 mm, 0.7 mm, and 1.1 mm.

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