Infrared detector system with low shielding and high response rate

Abstract

The invention relates to an infrared detector system with low shielding and high response rate. The infrared detector system comprises a concave reflecting mirror, a reflecting rotating mirror, an elliptical reflecting mirror and an infrared sensor, a set angle is formed between the reflecting rotating mirror and the incident light, and a concave reflecting mirror opposite to the emergent range of the emergent light of the reflecting rotating mirror is arranged at a position which is separated from the reflecting rotating mirror by a set distance; the elliptical reflecting mirror is arranged at the center L2 away from the concave reflecting mirror; and an infrared sensor is fixedly arranged at the same height as the center of the elliptical reflecting mirror and is L1 away from the elliptical reflecting mirror. The infrared detection equipment has the beneficial effects that the window on the infrared detection equipment is made of the sapphire material, the infrared transmittance of the window made of the sapphire material is greater than 95%, the structural strength is excellent, and the durability is good; the clamping mechanism has low clamping force, so that deviation generated when the light rays are converged is avoided; the elliptical reflecting mirror deflects the light path to the side face in the converging process, shielding of the light path between the reflecting rotating mirror and the infrared sensor is reduced, and the response rate of effective light energy is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of infrared detection, and particularly relates to an infrared detector system with low occlusion and high response rate. Background Art

[0002] In the field of forest and grassland fire prevention and control, spectral sensors are mostly used to measure radiation signals for flame detection. However, when existing integrated spectral detectors operate in the imaging mode, due to the insufficient light transmission frequency bandwidth of the light-transmitting waveguide window, the information required for generating images is insufficient, and finally, a sufficiently clear spectral image cannot be generated. In addition, the manufacturing accuracy requirements for optical lenses are high, the requirements for optical path design are high, and the imaging field area is limited by the sensor area size and the optical path characteristics of optical components, and a 360-degree panoramic view cannot be directly formed.

[0003] In addition, some cutting-edge technologies have also proposed technical solutions that can obtain panoramic views, but:

[0004] Germanium / silicon materials are mostly used for the window glass of infrared monitoring devices. The light-transmitting area is small, the structural strength requirements are not high, and the cost is also low. However, due to the need for 360-degree panoramic detection of fire sentinels, there is currently no glass with a large area and high infrared transmittance that meets the requirements on the market.

[0005] When implementing 360-degree panoramic detection, existing technologies mostly use rotatable reflectors. However, the force exerted by the clamping device for the rotatable reflector on the reflector will cause slight deformation of the rotating mirror assembly. This deformation directly leads to deviation when light rays converge, affecting the data response accuracy at the sensor end.

[0006] The optical path convergence focus of the concave mirror is located directly above the mirror surface. In a previous patent application of the inventor, an infrared sensor was arranged at the focus of the concave mirror for spectral collection. However, the infrared sensor will physically block the optical path, resulting in most of the light rays of the optical path being blocked, and the response rate of the effective light energy is low, making the effect of infrared detection poor. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an infrared detector system with low occlusion and high response rate.

[0008] An elliptical mirror has a minor axis ranging from 35.9 mm to 36.1 mm, a major axis ranging from 50.82 mm to 60.02 mm, and a thickness ranging from 12 mm to 13 mm; a 20 nm to 100 nm gold reflective film is coated on the surface of the elliptical mirror, and a 20 nm to 100 nm silica reflective film is coated on the surface of the gold reflective film; the elliptical mirror has a chamfer with an angle of 45° and a width of 0.2 to 0.5 mm, and the chamfer is an inclined 45° edge with a width between 0.2 and 0.5 mm formed by removing a part of the mirror body from the edge of the elliptical mirror; the wavelength of the light passing through the elliptical mirror is 1 to 20 um.

[0009] Preferably, the elliptical mirror has a minor axis of 36 mm, a major axis of 50.92 mm, and a thickness of 12.5 mm; a 40 nm to 60 nm gold reflective film is coated on the surface of the elliptical mirror, and a 40 nm to 60 nm silica reflective film is coated on the surface of the gold reflective film; the surface finish of the elliptical mirror is 10 / 5.

[0010] This low-obstruction and high-response-rate infrared detector system using an elliptical mirror is installed inside an infrared detection device. There is a window on the infrared detection device, and it also includes: a concave mirror, a reflecting rotating mirror, and an infrared sensor; the reflecting rotating mirror forms a set angle with the incident light, and a concave mirror opposite to the outgoing light range of the reflecting rotating mirror is provided at a set distance from the reflecting rotating mirror; the elliptical mirror is set at a center distance L2 from the concave mirror; an infrared sensor is fixedly provided at a distance L1 from the elliptical mirror and at the same height as the center of the elliptical mirror;

[0011] The focal length of the concave mirror is λ and the radius is r; the total distance between the optical path centers of the elliptical mirror and the concave mirror is L2; the infrared sensor, the elliptical mirror, and the concave mirror meet the following conditions:

[0012] L1 > r;

[0013] L1 + L2 = λ;

[0014] The reflecting rotating mirror is laminated inside the clamping mechanism through an annular pressing layer. The clamping mechanism is a two-piece upper and lower split structure. The contour of the clamping mechanism matches the contour of the reflecting rotating mirror. The annular pressing layer is provided between the inner side wall of the clamping mechanism and the reflecting rotating mirror. Fixing parts integrated with the side edges are provided on both side edges of the upper and lower split bodies of the clamping mechanism. The fixing parts fix the upper and lower split bodies of the clamping mechanism while fixing the reflecting rotating mirror inside the clamping mechanism. The clamping mechanism has a low clamping force; the clamping mechanism is rotationally connected to a horizontal turntable located outside the clamping mechanism through a rotating shaft.

[0015] The elliptical mirror is installed on a fixed base. There are limiting protrusions on the fixed base. A groove is formed between the limiting protrusions and the fixed base, and the groove clamps the edge of the elliptical mirror. The fixed base is a hollow structure, fixed at the optical path center with low occlusion to the optical path. The central axis of the elliptical mirror is horizontal, and the fixed base enables the elliptical mirror to rotate at a certain initial angle benchmark in the vertical direction.

[0016] Preferably, the clamping mechanism is electrically connected to a motor, and the motor is also electrically connected to an encoder and a driving device. The encoder and the driving device are electrically connected to a host computer. The driving device is used to drive the motor to drive the clamping mechanism to rotate a set angle after receiving the control instruction from the host computer. The encoder is used to measure the rotation angle and position of the motor and send the measured rotation angle and position to the host computer.

[0017] Preferably, the fixed base includes a cross-shaped frame and a cylindrical-like mirror mounting part fixed at the center of the cross-shaped frame. A stepped step is formed between the outer wall and the inner wall of the cylindrical-like mirror mounting part. The elliptical mirror is inclined and clamped inside the step. The part between the longest end and the shortest end of the barrel wall of the cylindrical-like mirror mounting part is the accommodating space for the elliptical mirror. A limiting protrusion is fixedly provided at the center of the longest end of the barrel wall of the cylindrical-like mirror mounting part, and the part of the limiting protrusion higher than the mirror surface limits the edge of the elliptical mirror to prevent it from accidentally falling.

[0018] Preferably, the window on the infrared detection device is made of sapphire. The infrared transmittance of the sapphire window is greater than 95%, with excellent structural strength and good durability.

[0019] Preferably, a 20nm - 100nm gold reflective film is coated on the surfaces of both the concave mirror and the reflecting rotating mirror, and a 20nm - 100nm silica reflective film is coated on the surface of the gold reflective film.

[0020] Preferably, the concave mirror is the component with the highest requirement in the entire optical system and needs to have a very accurate focal length. After repeatedly testing the requirements of different focal lengths for the converging optical path, the diameter of the concave mirror is 100mm and the focal length is 200mm.

[0021] Preferably:

[0022] During the rotation period when the reflecting rotating mirror rotates downward, the horizontal turntable is in a stationary state. During the rotation period, the infrared sensor is used for spectral data sampling. During the rotation period when the reflecting rotating mirror rotates upward, the horizontal turntable is in a starting state. During the rotation period, the horizontal turntable is used to rotate a set angle in the horizontal direction.

[0023] The beneficial effects of the present invention are:

[0024] The window on the infrared detection device of the present invention is made of sapphire. The infrared transmittance of the sapphire window is greater than 95%, with excellent structural strength and good durability.

[0025] The present invention laminates a reflecting turret within a clamping mechanism through an annular pressing layer. The clamping mechanism has a low clamping force and hardly causes deformation of the reflecting turret, avoiding deviation during light convergence and not affecting the data response accuracy at the sensor end.

[0026] The present invention provides an elliptical mirror at a specific position between the optical path of the reflecting turret and the concave mirror. The elliptical mirror is installed on a fixed base, and the fixed base is fixed at the optical path center with low occlusion to the optical path. The central axis of the elliptical mirror is horizontal, and the fixed base enables the elliptical mirror to rotate at a certain starting angle reference in the vertical direction. The elliptical mirror deflects the light path convergence process to the side, reducing occlusion and greatly improving the response rate of effective light energy. Description of the Drawings

[0027] Figure 1 Is a perspective view of the installed elliptical mirror;

[0028] Figure 2 Is a side view of the installed elliptical mirror;

[0029] Figure 3 Is a diagram showing the positional relationship among the elliptical mirror, the sensor, and the concave mirror;

[0030] Figure 4 Is the optical path schematic diagram of the infrared detector system of the present invention;

[0031] Figure 5 Is a cross-sectional view of the installation components of the reflecting turret;

[0032] Figure 6 Is a schematic diagram showing the relationship between the surface reflectance of the gold reflection film - silica reflection film on the surfaces of the elliptical mirror, the concave mirror, and the reflecting turret and the wavelength;

[0033] Figure 7 Is a schematic diagram showing the linkage state of the vertical turret and the horizontal turntable.

[0034] Description of the reference numerals: elliptical mirror 1, concave mirror 2, reflecting turret 3, infrared sensor 4, clamping mechanism 5, horizontal turntable 6, encoder 7, fixing part 8, annular pressing layer 9, limiting protrusion 10, fixed base 11. Detailed Embodiments

[0035] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0036] As an embodiment, as Figure 4 shown, an infrared detector system with low occlusion and high response rate, the infrared detector system is arranged in an infrared detection device, and a window made of sapphire material (infrared transmittance is greater than 95%, excellent in structural strength and good in durability) is arranged on the infrared detection device, including: an elliptical mirror 1, a concave mirror 2, a reflecting rotating mirror 3, and an infrared sensor 4; the reflecting rotating mirror 3 forms a set angle with the incident light, and a concave mirror 2 opposite to the outgoing light range of the reflecting rotating mirror 3 is arranged at a set distance from the reflecting rotating mirror 3; the elliptical mirror 1 is arranged at an L2 from the center of the concave mirror 2; an infrared sensor 4 is fixedly arranged at a height where the center of the elliptical mirror 1 is located and at an L1 from the elliptical mirror 1;

[0037] As Figure 3 shown, the focal length of the concave mirror 2 is λ and the radius is r; the total distance between the optical path centers of the elliptical mirror 1 and the concave mirror 2 is L2; the infrared sensor 4, the elliptical mirror 1, and the concave mirror 2 meet the following conditions:

[0038] L1>r;

[0039] L1 + L2 = λ;

[0040] As Figure 5 shown, the reflecting rotating mirror 3 is pressed into the clamping mechanism 5 through an annular pressing layer 9, the clamping mechanism 5 is a two-piece upper and lower split structure, the contour of the clamping mechanism 5 matches the contour of the reflecting rotating mirror 3, the annular pressing layer 9 is arranged between the inner side wall of the clamping mechanism 5 and the reflecting rotating mirror 3, and fixing parts 8 integrated with the side edges are arranged on both side edges of the upper and lower split parts of the clamping mechanism 5. The fixing parts 8 fix the upper and lower split parts of the clamping mechanism 5 and at the same time fix the reflecting rotating mirror 3 inside the clamping mechanism 5, and the clamping mechanism has a low clamping force; the clamping mechanism 5 is rotationally connected to a horizontal turntable 6 located outside the clamping mechanism 5 through a rotating shaft; the clamping mechanism 5 is electrically connected to a motor, the motor is also electrically connected to an encoder 7 and a driving device, and the encoder 7 and the driving device are electrically connected to a host computer; the driving device is used to drive the motor to drive the clamping mechanism 5 to rotate a set angle after receiving a control instruction from the host computer; the encoder 7 is used to measure the rotation angle and position of the motor and send the measured rotation angle and position to the host computer; As Figure 7As shown, during the rotation period when the reflecting rotating mirror 3 rotates downward, the horizontal turntable 6 is in a stationary state. During the rotation period, the infrared sensor 4 is used for spectral data sampling. During the rotation period when the reflecting rotating mirror 3 rotates upward, the horizontal turntable 6 is in a starting state. During the rotation period, the horizontal turntable 6 is used to rotate by a set angle in the horizontal direction.

[0041] As Figure 1 and Figure 2 shown, the elliptical reflecting mirror 1 is installed on the fixed base 11. The fixed base 11 is a hollow structure, fixed at the optical path center and with low obstruction to the optical path. The fixed base 11 includes a cross-shaped frame and a cylindrical mirror mounting part fixed at the center of the cross-shaped frame. A stepped step is formed between the outer wall and the inner wall of the cylindrical mirror mounting part. The elliptical reflecting mirror 1 is inclined and clamped in the step. The part between the longest end and the shortest end of the cylindrical wall of the cylindrical mirror mounting part is the accommodating space for the elliptical reflecting mirror 1. A limiting protrusion 10 is fixedly arranged at the center of the longest end of the cylindrical wall of the cylindrical mirror mounting part. The part of the limiting protrusion 10 higher than the mirror surface limits the edge of the elliptical reflecting mirror 1 to prevent it from accidentally falling. The central axis of the elliptical reflecting mirror 1 is horizontal. The fixed base 11 enables the elliptical reflecting mirror to rotate at a certain starting angle reference in the vertical direction.

[0042] The short axis of the elliptical reflecting mirror 1 is 36 mm, the long axis is 50.92 mm, and the thickness is 12.5 mm. As Figure 6 shown, a 50-nm gold reflecting film is plated on the surface of the elliptical reflecting mirror 1, and a 50-nm silicon dioxide reflecting film is plated on the surface of the gold reflecting film. The surface finish of the elliptical reflecting mirror is 10 / 5. The elliptical reflecting mirror has a chamfer with an angle of 45° and a width of 0.3 mm. The chamfer is an inclined 45° edge with a width of 0.3 mm formed by removing part of the mirror body from the edge of the elliptical reflecting mirror. The wavelength of the light passing through the elliptical reflecting mirror is 1 - 20 μm. The elliptical reflecting mirror is made of precision annealed H-K9L optical glass material.

[0043] The concave reflecting mirror 2 (D100mm - f200) has a diameter of 100 mm (tolerance +0.0 / -0.1), an effective focal length of 200 mm (tolerance ±2%), a central thickness of 5 mm (central thickness tolerance ±0.2), is made of precision annealed H-K9L optical glass material, and has a 20-nm to 100-nm gold reflecting film plated on its surface, and a 20-nm to 100-nm silicon dioxide reflecting film plated on the surface of the gold reflecting film (as Figure 6As shown in the figure); the concave mirror is the component with the highest requirements in the entire optical system and needs to have a very accurate focal length. After repeatedly testing the requirements of different focal lengths for the converging optical path, the diameter of the concave mirror 2 is 100 mm and the focal length is 200 mm; the reflected light wavelength is 587.6 nm, and the surface finish of the concave mirror 2 is 40 / 20 to 60 / 40; the concave mirror 2 has a chamfer with an angle of 45° and a width of 0.2 mm;

[0044] The size of the reflecting rotating mirror 3 is 150 mm * 100 mm * 2.3 mm (size tolerance -0.1 mm, thickness tolerance 0.5 mm), and it is made of precision annealed H-K9L optical glass material with a 3 mm thick chamfer at the edge; as Figure 6 shown, the surface of the reflecting rotating mirror 3 is coated with a gold reflecting film with a thickness of 20 nm to 100 nm, and a silica reflecting film with a thickness of 20 nm to 100 nm is coated on the surface of the gold reflecting film; the wavelength of the light passing through the reflecting rotating mirror 3 is 1 to 20 μm, and the surface finish of the reflecting rotating mirror 3 is 40 / 20 to 60 / 40; the reflecting rotating mirror 3 has a chamfer with an angle of 45° and a width of 0.2 mm;

[0045] In order to optimize the fine-tuning ability of the infrared sensor for the converging focal point of the optical path, the infrared sensor 4 is fixed on the micrometer table (used to adjust the size), and the ability of the sensor to receive the optical path focal point is adjusted by adjusting the three axes of x, y, and z, so that the infrared sensor 4 receives the maximum energy source signal, and the focal point can be maximally aligned with the detection point of the infrared sensor 4 during the production process. (Energy source: fixed distance, fixed energy, fixed direction.) (Because even a slight difference in the size of the optical device will result in a large data deviation, and there will be deviations during actual production even if the design value is fixed, so a micro-adjustment table is used for verification.).

Claims

1. An elliptical reflector, characterized in that: The short axis of the elliptical reflector is 35.9mm~36.1mm, the long axis is 50.82mm~60.02mm, and the thickness is 12mm~13mm; the surface of the elliptical reflector is coated with a layer of 20nm~100nm gold reflective film, and the surface of the gold reflective film is coated with a layer of 20nm~100nm silicon dioxide reflective film; the elliptical reflector has a chamfer with an angle of 45° and a width of 0.2~0.5mm, and the chamfer is an edge with an inclination of 45° and a width of 0.2~0.5mm formed by removing part of the mirror body from the edge of the elliptical reflector; the wavelength of light passing through the elliptical reflector is 1~20um.

2. The elliptical reflector according to claim 1, characterized in that: The short axis of the elliptical reflector is 36 mm, the long axis is 50.92 mm, and the thickness is 12.5 mm; the surface of the elliptical reflector is coated with a 40nm-60nm gold reflective film, and the surface of the gold reflective film is coated with a 40nm-60nm silicon dioxide reflective film; the surface finish of the elliptical reflector is 10 / 5.

3. An infrared detector system with low shading and high response rate using the elliptical reflector as claimed in claim 1 or 2, wherein the infrared detector system is arranged in an infrared detection device, and a window is arranged on the infrared detection device, wherein: It also comprises: a concave reflector (2), a reflective rotating mirror (3), and an infrared sensor (4); the reflective rotating mirror (3) forms a set angle with the incident light, and the concave reflector (2) is provided at a set distance from the reflective rotating mirror (3) and is opposite to the emission range of the emitted light of the reflective rotating mirror (3); the elliptical reflector (1) is provided at a center distance of L2 from the concave reflector (2); the infrared sensor (4) is fixedly provided at the same height as the center of the elliptical reflector (1) and at a distance of L1 from the elliptical reflector (1); The focal length of the concave reflector (2) is λ and the radius is r; the total distance between the optical path centers of the elliptical reflector (1) and the concave reflector (2) is L2; ​​the infrared sensor (4), the elliptical reflector (1) and the concave reflector (2) meet the following conditions: L1＞r； L1+L2=λ; The reflective rotating mirror (3) is pressed into the clamping mechanism (5) through an annular pressing layer (9); the clamping mechanism (5) is a two-piece upper and lower split structure; the contour of the clamping mechanism (5) matches the contour of the reflective rotating mirror (3); the annular pressing layer (9) is arranged between the inner side wall of the clamping mechanism (5) and the reflective rotating mirror (3); both sides of the upper split and the lower split of the clamping mechanism (5) are provided with fixing parts (8) which are integral with the side edges; the fixing parts (8) fix the upper split and the lower split of the clamping mechanism (5) and fix the reflective rotating mirror (3) inside the clamping mechanism (5); the clamping mechanism (5) is rotatably connected to a horizontal turntable (6) located outside the clamping mechanism (5) through a rotating shaft; The elliptical reflector (1) is mounted on the fixed base (11); a limiting protrusion (10) is provided on the fixed base (11); a groove is formed between the limiting protrusion (10) and the fixed base (11); the groove locks the edge of the elliptical reflector (1); the fixed base (11) is a hollow structure; the fixed base (11) is fixed at the center of the optical path and has low shielding for the optical path; the central axis of the elliptical reflector (1) is horizontal; the fixed base (11) enables the elliptical reflector to rotate in a vertical direction at a certain starting angle reference.

4. The infrared detector system according to claim 3, characterized in that: The clamping mechanism (5) is electrically connected to a motor, and the motor is also electrically connected to an encoder (7) and a drive device, and the encoder (7) and the drive device are electrically connected to a host computer; the drive device is used to drive the motor to drive the clamping mechanism (5) to rotate to a set angle after receiving a control instruction from the host computer; the encoder (7) is used to measure the rotation angle and position of the motor and send the measured rotation angle and position to the host computer.

5. The infrared detector system according to claim 3, characterized in that: The fixed base (11) comprises a field-shaped frame and a cylindrical reflector mounting portion fixed at the center of the field-shaped frame; a stepped step is formed between the outer wall and the inner wall of the cylindrical reflector mounting portion; the elliptical reflector (1) is obliquely clamped in the step; the portion between the longest end and the shortest end of the cylindrical wall of the cylindrical reflector mounting portion is the accommodating space for the elliptical reflector (1); the limiting protrusion (10) is fixedly provided at the center of the longest end of the cylindrical wall of the cylindrical reflector mounting portion; the portion of the limiting protrusion (10) that is higher than the mirror surface limits the edge of the elliptical reflector (1).

6. The infrared detector system according to claim 3, characterized in that: The window on the infrared detection device is made of sapphire material, and the infrared transmittance of the sapphire window is greater than 95%.

7. The infrared detector system according to claim 3, characterized in that: The surfaces of the concave reflective mirror (2) and the reflective rotating mirror (3) are both coated with a layer of gold reflective film with a thickness of 20nm to 100nm, and the surface of the gold reflective film is coated with a layer of silicon dioxide reflective film with a thickness of 20nm to 100nm.

8. The infrared detector system according to claim 3, characterized in that: The concave reflecting mirror (2) has a diameter of 100 mm and a focal length of 200 mm.

9. The infrared detector system according to claim 3, characterized in that: During the rotation period of the reflective mirror (3) rotating downward, the horizontal turntable (6) is in a stationary state, and during the rotation period, the infrared sensor (4) is used to perform spectral data sampling; During the rotation period in which the reflective mirror (3) rotates upward, the horizontal turntable (6) is in a start-up state. During the rotation period, the horizontal turntable (6) is used to rotate at a set angle in the horizontal direction.

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