Infrared camera device

Abstract

The utility model provides an infrared camera device. The infrared camera device sequentially comprises a first surface, a first diffraction surface, a second diffraction surface, a second surface and an imaging chip from a first side to a second side, the first diffraction surface and the second diffraction surface have positive diopters, the focal lengths of the first diffraction surface and the second diffraction surface are different, and the first diffraction surface and the second diffraction surface are super surfaces. According to the utility model, the problem of poor imaging quality of an infrared camera device in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging devices, and more particularly, to an infrared imaging device. Background Art

[0002] With the rapid development of augmented reality technology, eye tracking technology, as a key link, has also made remarkable progress. Eye tracking technology captures the movement trajectory of the human eye in three-dimensional space, revealing the process of people's visual focus and cognition, thus playing a crucial role in AR interaction.

[0003] In eye tracking technology, infrared imaging devices play an indispensable and important role. However, traditional infrared imaging devices generally use plastic aspherical lenses. Although such lenses meet the basic imaging requirements, there are some inherent problems, such as difficulty in miniaturization and large aberration, resulting in poor imaging quality of infrared imaging devices.

[0004] That is to say, the infrared imaging devices in the prior art have the problem of poor imaging quality. Summary of the Utility Model

[0005] The main object of the utility model is to provide an infrared imaging device to solve the problem of poor imaging quality of infrared imaging devices in the prior art.

[0006] To achieve the above object, the utility model provides an infrared imaging device, which sequentially includes a first surface, a first diffractive surface, a second diffractive surface, a second surface and an imaging chip from the first side to the second side. Among them, both the first diffractive surface and the second diffractive surface have positive diopters, and the focal lengths of the first diffractive surface and the second diffractive surface are different. Both the first diffractive surface and the second diffractive surface are metasurfaces.

[0007] Furthermore, the infrared imaging device further includes a diaphragm, and the diaphragm is disposed on the first surface.

[0008] Furthermore, the on-axis distance d between the first diffractive surface and the second diffractive surface and the distance TTL from the first surface to the imaging chip on the optical axis satisfy: 0.5 < d / TTL < 0.7.

[0009] Furthermore, the focal length f1 of the first diffractive surface is greater than the focal length f2 of the second diffractive surface, and / or the focal length f1 of the first diffractive surface and the focal length f2 of the second diffractive surface satisfy: 1.26 < f1 / f2 < 1.99.

[0010] Furthermore, the focal length f1 of the first diffractive surface and the total focal length f of the infrared imaging device satisfy: 1.60 < f1 / f < 2.20; and / or the focal length f2 of the second diffractive surface and the total focal length f of the infrared imaging device satisfy: 1.00 < f2 / f < 1.40.

[0011] Furthermore, the distance TTL from the first surface to the imaging chip on the optical axis and the image height Imgh of the infrared imaging device satisfy: 2.4 < TTL / Imgh < 3.2; and / or the maximum field of view FOV of the infrared imaging device satisfies: 90° ≤ FOV ≤ 105.7°.

[0012] Furthermore, the metasurface includes a plurality of column structures, and the plurality of column structures are arranged in an array to form an array structure, and at least one of the period, density of the array structure of the first diffractive surface and the array structure of the second diffractive surface, and the size of the column structure is different.

[0013] Furthermore, the height of the column structure is greater than or equal to 300 nm and less than or equal to 500 nm.

[0014] Furthermore, both the first surface and the second surface are flat, and / or the infrared imaging device further includes a narrowband bandpass filter film, and the narrowband bandpass filter film is disposed on at least one of the first surface and the second surface.

[0015] Furthermore, the infrared imaging device further includes a substrate, a first protective layer, and a second protective layer. The two side surfaces of the substrate are respectively the first diffractive surface and the second diffractive surface. The first protective layer is disposed on the first diffractive surface, and the surface of the first protective layer away from the first diffractive surface is the first surface. The second protective layer is disposed on the second surface, and the surface of the second protective layer away from the second diffractive surface is the second surface.

[0016] Applying the technical solution of the present utility model, the infrared imaging device sequentially includes a first surface, a first diffractive surface, a second diffractive surface, a second surface, and an imaging chip from the first side to the second side. Among them, both the first diffractive surface and the second diffractive surface have positive refractive power, and the focal lengths of the first diffractive surface and the second diffractive surface are different. Both the first diffractive surface and the second diffractive surface are metasurfaces.

[0017] The present application sets a first diffraction surface and a second diffraction surface, and plans that both the first diffraction surface and the second diffraction surface have positive refractive power, and sets the focal lengths of the first diffraction surface and the second diffraction surface to be different, so that the first diffraction surface can phase modulate the light, play a role in turning the angle of the light, which is equivalent to a lens with positive refractive power, and the second diffraction surface further phase modulates the light, turns the light and images it on the imaging chip, and the second diffraction surface is equivalent to a lens with positive refractive power. This setting can ensure that the light can accurately fall into the imaging chip after passing through the first diffraction surface and the second diffraction surface, and can effectively correct the aberration, so that the infrared camera device has good optical performance and imaging quality, and sets the first diffraction surface and the second diffraction surface at the same time, on the premise of being able to effectively turn the light and meet specific imaging requirements, avoid the situation of using multiple lenses, help to compress the total optical length of the infrared camera device, and help to achieve lightweight and miniaturization. In addition, the first surface not only provides effective protection for the first diffraction surface, but also ensures that the light can propagate smoothly; the second surface also provides necessary protection for the second diffraction surface, while ensuring that the light can be transmitted stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0019] Figure 1 A schematic structural diagram of an infrared camera device according to an optional embodiment of the utility model is shown;

[0020] Figure 2 Shows Figure 1 Aberration diagram of light rays of the infrared camera device in FIG.

[0021] Figure 3 A partial schematic diagram showing an array structure of a metasurface of an infrared camera device according to an optional embodiment of the utility model is shown;

[0022] Figure 4 Shows Figure 3 Schematic diagram of the structure of the column structure of the metasurface.

[0023] The above drawings include the following reference numerals:

[0024] 11. First surface; 21. First diffraction surface; 22. Second diffraction surface; 12. Second surface; 30. Imaging chip; 40. Array area; 41. Column structure. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0027] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0028] In order to solve the problem of poor imaging quality of infrared camera devices in the prior art, the present invention provides an infrared camera device.

[0029] like Figures 1 to 4 As shown, the infrared camera device includes a first surface 11, a first diffraction surface 21, a second diffraction surface 22, a second surface 12 and an imaging chip 30 from the first side to the second side, wherein the first diffraction surface 21 and the second diffraction surface 22 both have positive refractive power, and the focal lengths of the first diffraction surface 21 and the second diffraction surface 22 are different, and the first diffraction surface 21 and the second diffraction surface 22 are both metasurfaces.

[0030] The present application sets a first diffraction surface 21 and a second diffraction surface 22, and plans that both the first diffraction surface 21 and the second diffraction surface 22 have positive refractive power, and sets the focal lengths of the first diffraction surface 21 and the second diffraction surface 22 to be different, so that the first diffraction surface 21 can phase modulate the light, play a role in turning the angle of the light, which is equivalent to a lens with positive refractive power, and the second diffraction surface 22 further phase modulates the light, turns the light and forms an image on the imaging chip 30, and the second diffraction surface 22 is equivalent to a lens with positive refractive power. Such a setting can ensure that the light can accurately fall into the imaging chip 30 after passing through the first diffraction surface 21 and the second diffraction surface 22, and can effectively correct the aberration, so that the infrared camera device has good optical performance and imaging quality, and the first diffraction surface 21 and the second diffraction surface 22 are set at the same time, and on the premise of being able to effectively turn the light and meet specific imaging requirements, it avoids the situation of using multiple lenses, which helps to compress the total optical length of the infrared camera device and helps to achieve lightweight and miniaturization. In addition, the first surface 11 not only provides effective protection for the first diffraction surface 21, but also ensures that the light can propagate smoothly; the second surface 12 also provides necessary protection for the second diffraction surface 22, while ensuring that the light can be transmitted stably.

[0031] It should be noted that the first side of the infrared camera device is the light incident side of the infrared camera device, and the second side is the imaging side of the infrared camera device.

[0032] also, Figure 2 The light aberration diagram of the infrared camera device of the present application is shown. It can be seen from the figure that the overlap degree of light of each wavelength in the imaging process is significantly improved, indicating that the aberration is effectively controlled, indicating that the infrared camera device of the present application is better in reducing aberration.

[0033] Specifically, the infrared camera device further includes an aperture, which is arranged on the first surface 11. By reasonably setting the position of the aperture, effective convergence of the light beam is achieved, which can not only effectively constrain the incident light beam and field of view of the infrared camera device, but also help to make the layout of various components of the infrared camera device more compact and meet the requirements of miniaturization.

[0034] Specifically, the on-axis distance d between the first diffraction surface 21 and the second diffraction surface 22 and the distance TTL from the first surface 11 to the imaging chip 30 on the optical axis satisfy: 0.5<d / TTL<0.7. By constraining the ratio of the on-axis distance d between the first diffraction surface 21 and the second diffraction surface 22 and the distance TTL from the first surface 11 to the imaging chip 30 on the optical axis, it is beneficial to shorten the overall length of the infrared camera device as much as possible while ensuring the imaging quality, thereby meeting the miniaturization requirements. In an optional embodiment of the present application, d / TTL=0.5. In another optional embodiment of the present application, d / TTL=0.7.

[0035] Specifically, the focal length f1 of the first diffraction surface 21 is greater than the focal length f2 of the second diffraction surface 22, and the focal length f1 of the first diffraction surface 21 and the focal length f2 of the second diffraction surface 22 satisfy: 1.26<f1 / f2<1.99. By constraining the ratio of the focal length of the first diffraction surface 21 to the focal length of the second diffraction surface 22, the overall optical power of the infrared camera device can be reasonably distributed, thereby ensuring the rationality of f1 and f2, which is conducive to correcting the aberration of the optical system and ensuring the imaging quality.

[0036] Specifically, the focal length f1 of the first diffractive surface 21 and the total focal length f of the infrared imaging device satisfy: 1.60 < f1 / f < 2.20; the focal length f2 of the second diffractive surface 22 and the total focal length f of the infrared imaging device satisfy: 1.00 < f2 / f < 1.40. By restricting the ratio of the focal length of the first diffractive surface 21 to the total focal length of the infrared imaging device and the ratio of the focal length of the second diffractive surface 22 to the total focal length of the infrared imaging device, it is beneficial to control the proportion of the focal length f1 of the first diffractive surface 21 and the focal length f2 of the second diffractive surface 22 in the total focal length f of the infrared imaging device, ensure the reasonable distribution of f1 and f2, facilitate controlling the focusing position and imaging size of the light after passing through the first diffractive surface 21 and the second diffractive surface 22, cooperate with the imaging chip 30 to ensure the imaging quality, and simultaneously correct the aberration of the optical system. By optimizing the ratio of each focal length, it is also possible to make the structure of the infrared imaging device more compact while ensuring the imaging quality, meeting the miniaturization requirements.

[0037] Specifically, the distance TTL from the first surface 11 to the imaging chip 30 on the optical axis and the image height Imgh of the infrared imaging device satisfy: 2.4 < TTL / Imgh < 3.2. In alternative embodiments of the present application, TTL / Imgh = 2.435, TTL / Imgh = 3.043, TTL / Imgh = 2.634, TTL / Imgh = 2.639. When the image height remains unchanged, the smaller the TTL / Imgh, the smaller the total optical length of the infrared imaging device. Therefore, restricting the ratio of TTL to Imgh helps to achieve the miniaturization of the infrared imaging device.

[0038] In addition, the maximum field of view FOV of the infrared imaging device satisfies: 90° ≤ FOV ≤ 105.7°. By restricting the range of the maximum field of view of the infrared imaging device, it helps to ensure that the infrared imaging device has the property of a large field of view.

[0039] As Figure 3 and Figure 4 shown, the metasurface includes a plurality of column structures 41. The plurality of column structures 41 are arranged in an array to form an array structure. At least one of the period, density of the array structure of the first diffractive surface 21 and the array structure of the second diffractive surface 22, and the size of the column structure 41 is different. The shape of one column structure 41 can be one of a cylinder, a prism, and an elliptical cylinder. By adjusting at least one of the period, density of the array structure of the first diffractive surface 21 and the array structure of the second diffractive surface 22, and the size of the column structure 41 to be different, it is possible to adjust the first diffractive surface 21 and the second diffractive surface 22 to have different optical phase modulation effects, so that the first diffractive surface 21 and the second diffractive surface 22 have different diopters.

[0040] Figure 3A partial top view of a metasurface in an optional embodiment of the present application is shown. It can be seen from the figure that the multiple column structures 41 of the metasurface are divided into three array areas 40. The three array areas 40 are arranged sequentially from left to right. The multiple column structures 41 in each array area 40 are arranged in a periodic array. The diameters of the multiple column structures 41 in the same array area 40 gradually increase from left to right, and the diameter variation patterns of the column structures 41 in different array areas 40 are the same or different. Figure 4 Shows Figure 3 The structural diagram of the column structure 41 in FIG. 4 is a cylindrical column. Of course, Figure 3 The metasurface in the embodiment may be the first diffraction surface 21 or the second diffraction surface 22, and may be set according to actual conditions.

[0041] Specifically, the column structure 41 is a nanostructure. Specifically, the height of the column structure 41 is greater than or equal to 300 nm and less than or equal to 500 nm. The size of the column structure 41 is determined based on the phase distribution of the light wave passing through the metasurface. By controlling the height of the column structure 41, it is helpful for the phase distribution of light waves of different wavelengths to meet the imaging requirements after passing through the metasurface, while meeting the current processing technology capabilities, ensuring the manufacturing feasibility of the column structure 41.

[0042] In a specific embodiment of the present application, the first surface 11 and the second surface 12 are both planes, and the infrared camera device further includes a narrowband bandpass filter film, and the narrowband bandpass filter film is arranged on at least one of the first surface 11 and the second surface 12. The narrowband bandpass filter film can be arranged only on the first surface 11, or only on the second surface 12, or on both the first surface 11 and the second surface 12. The narrowband bandpass filter film only allows light signals of a specific band to pass through, and blocks light signals outside the band. By setting the narrowband bandpass filter film, infrared light can be effectively captured and stray light interference of other bands can be reduced, the sensitivity and capture ability of the infrared camera device to infrared light can be enhanced, and the imaging quality can be guaranteed. At the same time, the narrowband bandpass filter film is arranged on at least one of the first surface 11 and the second surface 12 instead of adding a narrowband bandpass filter, which can reduce components, simplify the structure, and is conducive to miniaturization and easy production.

[0043] It should be noted that in the specific embodiments of the present application, the surface of the array structure that supports the first diffraction surface 21 and the surface of the array structure that supports the second diffraction surface 22 are both planes, but in other optional embodiments of the present application, the surface of the array structure that supports the first diffraction surface 21 and the surface of the array structure that supports the second diffraction surface 22 can be set as curved surfaces, specifically, they can be set to be one of spherical surfaces, aspherical surfaces and free-form surfaces.

[0044] Specifically, the infrared camera device further includes a substrate, a first protective layer and a second protective layer. The two side surfaces of the substrate are respectively the first diffraction surface 21 and the second diffraction surface 22. Specifically, the above-mentioned array structure is arranged on both side surfaces of the substrate to form the first diffraction surface 21 and the second diffraction surface 22. The first protective layer is covered on the first diffraction surface 21. The thickness of the first protective layer is greater than the height of the array structure of the first diffraction surface 21. The side surface of the first protective layer away from the first diffraction surface 21 is the first surface 11. The second protective layer is arranged on the second surface 12. The thickness of the second protective layer is greater than the height of the array structure of the second diffraction surface 22. The side surface of the second protective layer away from the second diffraction surface 22 is the second surface 12. By reasonably arranging the structure of the infrared camera device, the layout of each component is made more compact to meet the miniaturization requirements.

[0045] It should be noted that the infrared camera device of the present application is mainly used to detect and image light signals in the infrared band. Therefore, in the optional embodiments of the present application, the wavelength of the incident light is 0.94um, which belongs to the near-infrared band and is close to the wavelength of light signals in actual application scenarios.

[0046] The infrared camera device of the present application is described below in conjunction with specific embodiments.

[0047] Embodiment 1

[0048] The infrared camera device of this embodiment includes a first surface 11, a first diffraction surface 21, a second diffraction surface 22, a second surface 12 and an imaging chip 30 from the first side to the second side. The first surface 11 and the second surface 12 are both planes, and the first diffraction surface 21 and the second diffraction surface 22 are metasurfaces.

[0049] In this embodiment, the distance TTL from the first surface 11 of the infrared camera device to the imaging chip 30 on the optical axis is 2.80 mm, the image height Imgh of the infrared camera device is 1.15 mm, the aperture coefficient Fno of the infrared camera device is 1.37, the maximum field of view FOV of the infrared camera device is 120.01 deg, the focal length f1 of the first diffraction surface 21 is 2.07 mm, the focal length f2 of the second diffraction surface 22 is 1.64 mm, the total effective focal length f of the infrared camera device is 1.23 mm, and the wavelength of the incident light is 0.94 um.

[0050] Table 1 shows the basic structural parameters of the infrared camera device of this embodiment.

[0051] surface Surface type Radius of curvature Thickness(mm) Refractive index Nd Abbe number Vd Physical surface Standard surface unlimited infinity / / First surface 11 Spherical unlimited 0.555593945 1.52 54.51 First diffraction surface 21 Two-dimensional surface unlimited 1.4447074 1.52 54.51 The second diffraction surface 22 Two-dimensional surface unlimited 0.399914674 1.52 54.51 Second surface 12 Spherical unlimited 0.399871075 / / Imaging chip 30 Standard surface unlimited / / /

[0052] Table 1

[0053] Table 2 shows the diffraction parameters of the first diffraction surface 21 and the second diffraction surface 22 in this embodiment, which are given by formula (1).

[0054] Surface / diffraction parameters <![CDATA[m0]]> <![CDATA[λ0(um)]]> M Norm Radius <![CDATA[ρ 2 ]]> <![CDATA[ρ 4 ]]> First diffraction surface 21 1 0.94 8 1 -1613.37 691.4798 The second diffraction surface 22 1 0.94 8 1 -2040.86 667.2036 Surface / diffraction parameters <![CDATA[ρ 6 ]]> <![CDATA[ρ 8 ]]> <![CDATA[ρ 10 ]]> <![CDATA[ρ 12 ]]> <![CDATA[ρ 14 ]]> <![CDATA[ρ 16 ]]> First diffraction surface 21 -4537.55 10681.89 -12253.2 5565.824 -4.60508 -2.98875 The second diffraction surface 22 -709.578 708.861 -307.821 50.57227 0.102916 0.12034

[0055] Table 2

[0056]

[0057] Where M is the designed diffraction order, A i is the coefficient of ρ raised to the 2ith power, and n is the number of polynomial coefficients in the series.

[0058] Embodiment 2

[0059] The infrared camera device of this embodiment includes a first surface 11, a first diffraction surface 21, a second diffraction surface 22, a second surface 12 and an imaging chip 30 from the first side to the second side. The first surface 11 and the second surface 12 are both planes, and the first diffraction surface 21 and the second diffraction surface 22 are metasurfaces.

[0060] In this embodiment, the distance TTL from the first surface 11 of the infrared camera device to the imaging chip 30 on the optical axis is 3.50 mm, the image height Imgh of the infrared camera device is 1.15 mm, the aperture coefficient Fno of the infrared camera device is 1.38, the maximum field of view FOV of the infrared camera device is 90.00 deg, the focal length f1 of the first diffraction surface 21 is 3.23 mm, the focal length f2 of the second diffraction surface 22 is 1.63 mm, the total effective focal length f of the infrared camera device is 1.48 mm, and the wavelength of the incident light is 0.94 um.

[0061] Table 3 shows the basic structural parameters of the infrared camera device of this embodiment.

[0062]

[0063]

[0064] Table 3

[0065] Table 4 shows the diffraction parameters of the first diffraction surface 21 and the second diffraction surface 22 in this embodiment.

[0066] Surface / diffraction parameters m0 λ0(um) M Norm Radius ρ2 ρ4 First diffraction surface 21 1 0.94 8 1 -1033.17971 294.34933 The second diffraction surface 22 1 0.94 8 1 -2055.65831 508.90266 Surface / diffraction parameters ρ6 ρ8 ρ10 ρ12 ρ14 ρ16 First diffraction surface 21 -2681.53399 15058.32073 -47436.62815 78168.97915 -61303.83327 16686.72399 The second diffraction surface 22 -1475.63120 2517.37682 -2451.55671 1377.28503 -415.29213 51.99246

[0067] Table 4

[0068] Embodiment 3

[0069] The infrared camera device of this embodiment includes a first surface 11, a first diffraction surface 21, a second diffraction surface 22, a second surface 12 and an imaging chip 30 from the first side to the second side. The first surface 11 and the second surface 12 are both planes, and the first diffraction surface 21 and the second diffraction surface 22 are metasurfaces.

[0070] In this embodiment, the distance TTL from the first surface 11 of the infrared camera device to the imaging chip 30 on the optical axis is 3.03 mm, the image height Imgh of the infrared camera device is 1.15 mm, the aperture coefficient Fno of the infrared camera device is 1.37, the maximum field of view FOV of the infrared camera device is 97.17 degrees, the focal length f1 of the first diffraction surface 21 is 2.58 mm, the focal length f2 of the second diffraction surface 22 is 1.50 mm, the total effective focal length f of the infrared camera device is 1.34 mm, and the wavelength of the incident light is 0.94 um.

[0071] Table 5 shows the basic structural parameters of the infrared camera device of this embodiment.

[0072] surface Surface type Radius of curvature Thickness(mm) Refractive index Nd Abbe number Vd Physical surface Standard surface unlimited infinity / / First surface 11 Spherical unlimited 0.40153 1.52 54.51 First diffraction surface 21 Two-dimensional surface unlimited 1.81445 1.52 54.51 The second diffraction surface 22 Two-dimensional surface unlimited 0.29999 1.52 54.51 Second surface 12 Spherical unlimited 0.51889 / / Imaging chip 30 Standard surface unlimited / / /

[0073] Table 5

[0074] Table 6 shows the diffraction parameters of the first diffraction surface 21 and the second diffraction surface 22 in this embodiment, which are given by formula (1).

[0075] Surface / diffraction parameters m0 λ0(um) M Norm Radius ρ2 ρ4 First diffraction surface 21 1 0.94 8 1 -1297.90496 640.44553 The second diffraction surface 22 1 0.94 8 1 -2232.40737 548.34384 Surface / diffraction parameters ρ6 ρ8 ρ10 ρ12 ρ14 ρ16 First diffraction surface 21 -4593.85698 18549.54665 -47802.64399 73155.05070 -60972.54632 22087.71667 The second diffraction surface 22 -1463.92229 2523.15721 -2451.94403 1376.71276 -414.96467 51.83665

[0076] Table 6

[0077] Embodiment 4

[0078] The infrared camera device of this embodiment includes a first surface 11, a first diffraction surface 21, a second diffraction surface 22, a second surface 12 and an imaging chip 30 from the first side to the second side. The first surface 11 and the second surface 12 are both planes, and the first diffraction surface 21 and the second diffraction surface 22 are metasurfaces.

[0079] In this embodiment, the distance TTL from the first surface 11 of the infrared camera device to the imaging chip 30 on the optical axis is 3.03 mm, the image height Imgh of the infrared camera device is 1.15 mm, the aperture coefficient Fno of the infrared camera device is 1.37, the maximum field of view FOV of the infrared camera device is 105.70 deg, the focal length f1 of the first diffraction surface 21 is 2.42 mm, the focal length f2 of the second diffraction surface 22 is 1.40 mm, the total effective focal length f of the infrared camera device is 1.24 mm, and the wavelength of the incident light is 0.94 um.

[0080] Table 7 shows the basic structural parameters of the infrared camera device of this embodiment.

[0081] surface Surface type Radius of curvature Thickness(mm) Refractive index Nd Abbe number Vd Physical surface Standard surface unlimited infinity / / First surface 11 Spherical unlimited 0.49400 1.52 54.51 First diffraction surface 21 Two-dimensional surface unlimited 1.66574 1.52 54.51 The second diffraction surface 22 Two-dimensional surface unlimited 0.57506 1.52 54.51 Second surface 12 Spherical unlimited 0.29999 / / Imaging chip 30 Standard surface unlimited / /

[0082] Table 7

[0083] Table 8 shows the diffraction parameters of the first diffraction surface 21 and the second diffraction surface 22 in this embodiment, which are given by formula (1).

[0084] Surface / diffraction parameters m0 λ0(um) M Norm Radius ρ2 ρ4 First diffraction surface 21 1 0.94 8 1 -1378.23416 607.17608 The second diffraction surface 22 1 0.94 8 1 -2392.16895 591.73315 Surface / diffraction parameters ρ6 ρ8 ρ10 ρ12 ρ14 ρ16 First diffraction surface 21 -5100.82368 21683.74063 -53546.24104 70508.66164 -40994.58943 5032.99625 The second diffraction surface 22 -1482.42665 2524.29285 -2449.57164 1377.50069 -415.07405 51.65629

[0085] Table 8

[0086] Table 9 below describes the field of view angle values ​​corresponding to the infrared camera devices of the above-mentioned embodiments 1 to 4 at different image heights.

[0087]

[0088]

[0089] Table 9

[0090] In summary, Embodiments 1 to 4 respectively satisfy the relationship shown in Table 10.

[0091] Conditional / Example Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 d / TTL 0.516 0.562 0.6 0.549 f1 / f2 1.262 1.982 1.720 1.729 TTL / Imgh 2.435 3.043 2.634 2.639 f1 / f 1.683 2.182 1.925 1.952 f2 / f 1.333 1.101 1.119 1.129

[0092] Table 10

[0093] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0094] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0095] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0096] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An infrared camera device, characterized in that: It sequentially includes a first surface (11), a first diffractive surface (21), a second diffractive surface (22), a second surface (12), and an imaging chip (30) from the first side to the second side. Among them, both the first diffractive surface (21) and the second diffractive surface (22) have positive refractive power, and the focal lengths of the first diffractive surface (21) and the second diffractive surface (22) are different. Both the first diffractive surface (21) and the second diffractive surface (22) are metasurfaces.

2. The infrared camera device according to claim 1, characterized in that: The infrared imaging device further includes a diaphragm, and the diaphragm is disposed on the first surface (11).

3. The infrared camera device according to claim 1, characterized in that: The on-axis distance d between the first diffractive surface (21) and the second diffractive surface (22) and the distance TTL from the first surface (11) to the imaging chip (30) on the optical axis satisfy: 0.5 < d / TTL < 0.

7.

4. The infrared camera device according to claim 1, characterized in that: The focal length f1 of the first diffractive surface (21) is greater than the focal length f2 of the second diffractive surface (22), and / or the focal lengths f1 of the first diffractive surface (21) and f2 of the second diffractive surface (22) satisfy: 1.26 < f1 / f2 < 1.

99.

5. The infrared camera device according to claim 1, characterized in that: The focal length f1 of the first diffractive surface (21) and the total focal length f of the infrared imaging device satisfy: 1.60 < f1 / f < 2.20; and / or The focal length f2 of the second diffractive surface (22) and the total focal length f of the infrared imaging device satisfy: 1.00 < f2 / f < 1.

40.

6. The infrared camera device according to any one of claims 1 to 5, characterized in that: The distance TTL from the first surface (11) to the imaging chip (30) on the optical axis and the image height Imgh of the infrared imaging device satisfy: 2.4 < TTL / Imgh < 3.2; and / or the maximum field of view FOV of the infrared imaging device satisfies: 90° ≤ FOV ≤ 105.7°.

7. The infrared camera device according to any one of claims 1 to 5, characterized in that: The metasurface includes a plurality of column structures (41), and the plurality of column structures (41) are arranged in an array to form an array structure. At least one of the period, density of the array structure of the first diffractive surface (21) and the array structure of the second diffractive surface (22), and the size of the column structure (41) is different.

8. The infrared camera device according to claim 7, characterized in that: The height of the column structure (41) is greater than or equal to 300 nm and less than or equal to 500 nm.

9. The infrared camera device according to any one of claims 1 to 5, characterized in that: Both the first surface (11) and the second surface (12) are flat surfaces, and / or the infrared imaging device further includes a narrowband bandpass filter film, and the narrowband bandpass filter film is disposed on at least one of the first surface (11) and the second surface (12).

10. The infrared camera device according to any one of claims 1 to 5, characterized in that: The infrared imaging device further includes a substrate, a first protective layer, and a second protective layer. The two side surfaces of the substrate are respectively the first diffractive surface (21) and the second diffractive surface (22). The first protective layer is disposed on the first diffractive surface (21), and the side surface of the first protective layer away from the first diffractive surface (21) is the first surface (11). The second protective layer is disposed on the second surface (12), and the side surface of the second protective layer away from the second diffractive surface (22) is the second surface (12).

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