Light uniformizing structure of integrating sphere cooperating with secondary light uniformizing element

Abstract

The invention discloses a dodging structure with an integrating sphere cooperating with a secondary dodging element, the dodging structure comprises the integrating sphere, a light source and the secondary dodging element, and the integrating sphere comprises a front hemisphere, a rear hemisphere and a light outlet; a plurality of light sources are mounted in the circumferential direction of the front hemisphere at equal intervals in an array manner, and all face the center of the integrating sphere; the light outlet is formed in the rear hemisphere; the light outlet and the light source are arranged on the same side of the integrating sphere, and the light outlet is located on the central vertical axis of the light source around the circumference; the surface roughness of the secondary dodging element is non-uniformly distributed, and the secondary dodging element is installed behind the light outlet. A special secondary dodging element is arranged at the light outlet of the integrating sphere, so that large-dynamic-range uniform radiation output under the condition of small volume can be realized, and the problems of poor angle uniformity of an infrared band black body and large volume of a large-dynamic-range integrating sphere are solved; the device is suitable for the fields of photoelectric system testing, guided weapon semi-physical simulation and the like which have certain volume and weight requirements on the device.

Description

Technical Field

[0001] The present invention belongs to the technical fields of optoelectronic system testing and semi-physical simulation of guided weapons, and relates to a light homogenizing structure, specifically to a light homogenizing structure integrating a integrating sphere and a special secondary light homogenizing element. Background Art

[0002] In actual optoelectronic system testing or semi-physical simulation of guided weapons, a light source with high illuminance uniformity and large dynamic range needs to be provided, and there are certain requirements for the volume and weight of the device. Currently, a blackbody can only be used as an infrared radiation source, and the uniformity of the blackbody is poor, especially the angular uniformity; the common light source components that can cover the visible and infrared bands are an integrating sphere and a high-temperature incandescent lamp, and the light homogenization of the high-temperature incandescent lamp is achieved through the diffuse reflection of the inner surface of the integrating sphere. However, the high-power incandescent lamp has a large volume. To achieve a good light homogenization effect, it is required that the volume of the integrating sphere increases correspondingly, which does not meet the requirement of lightweight of the device in optoelectronic system testing or semi-physical simulation of guided weapons. Summary of the Invention

[0003] The present invention provides a light homogenizing structure integrating an integrating sphere and a secondary light homogenizing element. By placing a special secondary light homogenizing element at the light outlet of the integrating sphere, uniform radiation output with a large dynamic range can be achieved under the condition of a small volume, solving the problems of poor angular uniformity of the blackbody in the infrared band and large volume of the integrating sphere with a large dynamic range, and being applicable to optoelectronic system testing and semi-physical simulation of guided weapons and other fields where there are certain requirements for the volume and weight of the device. At the same time, a special secondary light homogenizing element with a non-uniform surface roughness distribution designed according to the incident energy distribution can select appropriate materials according to the wavelength band, and is not limited to light homogenization after the integrating sphere, and can be applied to different types of light homogenizing devices in various wavelength bands.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A light homogenizing structure integrating an integrating sphere and a secondary light homogenizing element, comprising an integrating sphere, a light source, and a secondary light homogenizing element, wherein:

[0006] The integrating sphere includes a front hemisphere, a rear hemisphere, and a light outlet;

[0007] A plurality of light sources are installed on the front hemisphere in a circumferentially equally spaced array, and all the light sources are directed towards the center of the integrating sphere;

[0008] The light outlet is arranged on the rear hemisphere;

[0009] The light outlet and the light source are arranged on the same side of the integrating sphere, and the light outlet is located on the vertical axis of the circumferential center of the light source;

[0010] The surface roughness of the secondary light homogenizing element is non-uniformly distributed, and it is installed behind the light outlet to further homogenize the diffuse reflection light beam of the integrating sphere.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] The present invention creatively proposes a light homogenization structure of an integrating sphere cooperating with a special secondary light homogenizing element. The special secondary light homogenizing element is formed by grinding or sandblasting a double-polished optical substrate with fine particles. The surface roughness is set according to the energy distribution of the light emitted from the integrating sphere, with a deeper grinding degree in the high-energy region and a shallower degree in the low-energy region. The substrate can be made of different materials according to the wavelength band. Usually, K9 glass is used in the visible light band, and silicon wafers are used in the infrared band. Therefore, it is applicable to integrating sphere light homogenization devices in multiple wavelength bands. The combination of a conventional integrating sphere and a special secondary light homogenizing element can achieve the emission of a beam with a large dynamic range and high uniformity with a smaller volume and weight when the light source has high energy and a large volume. The present invention has the advantages of simple structure and low cost, which can facilitate the design of light homogenization devices in optoelectronic system testing or semi-physical simulation of guided weapons, and solve the problems in the prior art such as poor angular uniformity when using a blackbody as an infrared light homogenization device, poor output radiation uniformity of a small-volume and high-power integrating sphere, and the lightweight requirement for a large-dynamic-range light homogenization device in optoelectronic system testing or semi-physical simulation of guided weapons. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional view of the infrared light homogenization device of the present invention;

[0014] Figure 2 is a schematic diagram of the light source distribution of the infrared light homogenization device of the present invention;

[0015] In the figure: 100, integrating sphere; 200, light source; 300, secondary light homogenizing element; 400, heat dissipation device; 500, support device; 110, front hemisphere; 111, rear hemisphere; 112, light outlet; 210, reflecting bowl; 211, power supply; 212, wire. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The technical solutions of the present invention will be further described below in conjunction with the drawings, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0017] The present invention provides a light homogenization structure of an integrating sphere cooperating with a secondary light homogenizing element. The light homogenization structure includes an integrating sphere, a light source, and a secondary light homogenizing element, wherein:

[0018] The integrating sphere includes a front hemisphere, a rear hemisphere, and a light outlet;

[0019] A plurality of light sources are installed in a circumferentially equally spaced array on the front hemisphere. All the light sources are directed towards the center of the integrating sphere. The plane where the plurality of light sources are located is parallel to the cross-sectional plane of the integrating sphere and is as far away from the light outlet as possible;

[0020] The light-emitting port is arranged on the rear hemisphere;

[0021] The light-emitting port and the light source are arranged on the same side of the integrating sphere, and the light-emitting port is located on the vertical axis of the circumferential center of the light source;

[0022] The surface roughness of the secondary light homogenizing element is non-uniformly distributed, and it is installed behind the light-emitting port to further homogenize the diffused reflection light beam of the integrating sphere.

[0023] In the present invention, the integrating sphere is made of aluminum alloy, and the front hemisphere and the rear hemisphere are integrally formed or connected and combined to form an integrating sphere cavity sphere. The inner wall of the cavity sphere is uniformly coated with a diffuse reflection coating with a high reflectivity, and the joint between the front and rear spheres should not be visible from the inside of the integrating sphere cavity sphere.

[0024] In the present invention, the diffuse reflection coating is selected according to the wavelength range. The diffuse reflection coating in the visible light band is usually barium sulfate BaSO4, and the diffuse reflection coating in the infrared band is usually gold Au.

[0025] In the present invention, the surface roughness of the secondary light homogenizing element is non-uniformly distributed. According to the light energy distribution at the light-emitting port of the integrating sphere, it is ground or sandblasted with fine particles on a double-polished optical substrate. The grinding degree in the area with high incident energy is deeper, resulting in strong scattering, and the grinding degree in the area with low energy is shallower, resulting in weak scattering. Since the energy in the central area of the light-emitting port of the integrating sphere is relatively high, the grinding degree in the central area is deeper, and it gradually becomes shallower towards the periphery.

[0026] In the present invention, the double-polished optical substrate can be made of different materials according to the wavelength range. It is usually K9 glass in the visible light band and silicon wafer in the infrared band.

[0027] In the present invention, the light source can adopt a high-power halogen tungsten lamp.

[0028] Example:

[0029] Figure 1Shown is an infrared light homogenization device that applies the light homogenization structure of the integrating sphere of the present invention in cooperation with a special secondary light homogenization element to the hardware-in-the-loop simulation of a guided weapon. The infrared light homogenization device includes an integrating sphere 100, a light source 200, a secondary light homogenization element 300, and a heat dissipation device 400, where: The integrating sphere is composed of a front hemisphere 110, a rear hemisphere 111, and a light outlet 112; The light source 200 selects a high-power halogen tungsten lamp, is used in cooperation with a reflector bowl 210, and is connected in series by a wire 212 and uniformly powered by a power supply 211, and can output mid-wave infrared radiation with an equivalent blackbody temperature ≥ 300 °C and non-uniformity ≤ 1.5%; Five high-power halogen tungsten lamps are installed in a circumferentially equally spaced array on the front hemisphere 110, all facing the center of the integrating sphere 100; The light outlet 112 is arranged on the rear hemisphere 111, and the light outlet 112 is located on the vertical axis of the circumferential center of the light source 200; A secondary light homogenization element 300 is placed behind the light outlet 112 of the integrating sphere; The integrating sphere 100 is equipped with a heat dissipation device 400. The outer shell of the rear hemisphere 111 is designed with a special water-cooling pipeline to keep cold water circulating all the time, and air cooling is used on the front hemisphere 110, and a cooling fan is set up.

[0030] In this embodiment, the inner surface diameter of the integrating sphere 100 of the spherical cavity is 150 mm, the thickness of the shell is 8 mm, the diameter of the light outlet 112 is 26 mm, the front hemisphere 110 and the rear hemisphere 111 are integrally formed, and the shell material is aluminum alloy.

[0031] In the present invention, the inner surface of the integrating sphere 100 is aluminum alloy after sandblasting treatment. Therefore, the light beam undergoes multiple diffuse reflections inside, and finally forms a uniform effect on the light beam, and the radiation exits from the light outlet 112.

[0032] In this embodiment, the diameter of the secondary light homogenization element 300 is 26 mm, and the roughness is non-uniformly distributed. It is ground from a double-polished silicon wafer with sandpaper. Since the energy in the central area of the light outlet of the integrating sphere is relatively high, the grinding degree in the central area is deeper, and it gradually becomes shallower around.

[0033] In this embodiment, the rated voltage of the halogen tungsten lamp is 36 V, the power is 400 W, the total length is 60 mm, the diameter is 18 mm, and it can achieve a light flux output of 12200 lm. The plane where all the halogen tungsten lamps are located is parallel to the cross-section of the integrating sphere 100 and is as far away from the light outlet 112 as possible.

[0034] In this embodiment, the inner surface of the integrating sphere 100 is aluminum alloy after sandblasting treatment. Therefore, the light beam undergoes multiple diffuse reflections inside, and finally forms a uniform effect on the light beam, and the radiation exits from the light outlet 112; It is also possible to evenly apply a reflective material with high reflectivity, such as gold Au.

[0035] In this embodiment, the light source 200 is used in conjunction with the reflective bowl 210, and the reflective bowl 210 is not coated to prevent the film layer from falling off due to high temperature; the surface of the reflective bowl 210 is a quadratic surface or a free-form surface; the quadratic surface is usually a parabola, a hyperbolic surface, etc.; the size design should avoid the light source 200 from emitting light directly from the light outlet 112.

[0036] In this embodiment, the infrared radiation equivalent black body temperature at the light outlet 112 is calculated according to the following formula:

[0037]

[0038] Where M(T) is the black body at λ 1 -λ 2 Spectral radiant emittance within the band (W / m 2 ), λ is the wavelength (μm), T is the absolute temperature (K), c 1 is the first radiation constant, c 1 =3.7415×10^8(W·m -2 μm -1 );c 2 is the second radiation constant, c 2 =1.4388×10^4(μm·K).

[0039] In this embodiment, the non-uniformity at the light outlet 112 is calculated according to the following formula:

[0040] u=SDevT / AvgT×100%

[0041] Where u is the non-uniformity, AvgT is the average value of the equivalent blackbody temperature within the range, and SDevT is the standard deviation of the equivalent blackbody temperature at different positions.

[0042] In this embodiment, when the infrared homogenizing device is in use, its working process is: start the heat dissipation device 400; start the power supply 211 of the light source 200, and after a few minutes, stably emit uniform infrared radiation; perform a comprehensive optoelectronic system performance test; after use, turn off the power supply 211; after complete cooling, turn off the heat dissipation device 400.

[0043] In this embodiment, the light homogenization structure of the integrating sphere cooperating with the special secondary light homogenizing element is different from the common solution that only uses the integrating sphere as the light homogenizing element. Combining the secondary light homogenizing element can reduce the volume of the integrating sphere for primary light homogenization. The structure is simple, stable, and has a lower cost. Through the primary light homogenization of the high-power light source by the small-volume integrating sphere and further light homogenization by combining the special secondary light homogenizing element with non-uniform surface roughness distribution, they cooperate with each other to achieve a high-uniformity homogenization effect for high-power and large-volume light sources under lightweight conditions. It is applicable to lightweight light homogenization devices in fields such as precision optical measurement and semi-physical simulation of guided weapons. At the same time, the secondary light homogenizing element can change the light source type and the substrate material of the secondary light homogenizing element according to the usage requirements, and is applied to light homogenization devices in various bands such as visible light and infrared. It can also design the surface roughness according to the energy distribution before the light enters the element. In the area with high energy, the surface is relatively rough, and in the area with low energy, the surface is relatively smooth. Therefore, it is not limited to the further light homogenization of the integrating sphere and is applicable to various devices with light homogenization requirements to further improve the uniformity.

Claims

1. A light homogenization structure using an integrating sphere and a secondary light homogenization element, characterized in that The light homogenization structure includes an integrating sphere, a light source, and a secondary light homogenization element, wherein: The integrating sphere comprises a front hemisphere, a rear hemisphere and a light outlet; The front hemisphere is provided with a plurality of light sources in an equidistant array around the circumference, and the plurality of light sources are all directed toward the center of the integrating sphere; The light outlet is arranged on the rear hemisphere; The surface roughness of the secondary light homogenizing element is non-uniformly distributed, and it is installed behind the light outlet to further homogenize the diffusely reflected light beam of the integrating sphere.

2. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1 is characterized in that The light outlet and the light source are arranged on the same side of the integrating sphere.

3. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1 or 2, characterized in that The light outlet is located on a vertical axis around the center of the circle of the light source.

4. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1 is characterized in that The integrating sphere is made of aluminum alloy, and the front hemisphere and the rear hemisphere are integrally formed or connected to form an integrating sphere cavity sphere.

5. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 4 is characterized in that The inner wall of the cavity sphere is evenly coated with a diffuse reflection coating with high reflectivity.

6. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 5 is characterized in that The diffuse reflection coating is selected according to the wavelength range. The diffuse reflection coating in the visible light band is barium sulfate BaSO4, and the diffuse reflection coating in the infrared band is gold Au.

7. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1, characterized in that The surface roughness of the secondary light homogenizing element is non-uniformly distributed. According to the light energy distribution at the light outlet of the integrating sphere, the double-polished chemical substrate is ground or sandblasted with fine particles. The area with high incident energy is deeply polished, resulting in strong scattering, and the area with low energy is shallowly polished, resulting in weak scattering.

8. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 7 is characterized in that The double-glazed optical substrate is made of different materials according to the waveband, K9 glass is used for the visible light band, and silicon wafer is used for the infrared light band.

9. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1, characterized in that The light source adopts a halogen tungsten lamp.

10. The light homogenization structure of the integrating sphere and the secondary light homogenization element according to claim 1, characterized in that The infrared radiation equivalent blackbody temperature at the light outlet is calculated according to the following formula: Where M(T) is the spectral radiation emittance of the black body in the λ1-λ2 band; λ is the wavelength; T is the absolute temperature; c1 is the first radiation constant, c2 is the second radiation constant; The non-uniformity at the light outlet is calculated according to the following formula: u=SDevT / AvgT×100% Where u is the non-uniformity, AvgT is the average value of the equivalent blackbody temperature within the range, and SDevT is the standard deviation of the equivalent blackbody temperature at different positions.

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