Light trap

Abstract

The light trap comprises an incidence cavity, a reflection cavity and a reflection surface, the reflecting surface is arranged at the joint of the incident cavity and the reflecting cavity and is used for reflecting the incident light entering the incident cavity and then enabling the incident light to enter the reflecting cavity; the surface of the reflection cavity is provided with a light absorption surface or / and a reflection layer, the reflection layer is used for reflecting light, and the light absorption surface is used for absorbing light.

Description

Technical Field

[0001] The invention belongs to the technical field of laser absorption processing, and in particular relates to a light trap. Background Art

[0002] Laser forward scattering dust meter is a dust concentration measurement device based on the principle of laser scattering. It mainly calculates the dust concentration by detecting the scattered light intensity after the interaction between laser and dust particles.

[0003] like Figure 4 , Laser forward scattering dust meter, the laser emits a laser beam, and the dust particles will produce scattered light after passing through the beam. The photodetector measures the dust concentration by detecting the weak scattered light. The laser beam emitted by the laser must be absorbed by the light trap, otherwise it will produce strong background light and affect the dust concentration measurement.

[0004] The existing light trap is usually a cavity structure with a black inner wall, such as Figure 3 As shown, it is hoped that the laser beam emitted by the laser can be absorbed by the cavity after it is shot in. However, due to the processing technology of the cavity, the center point is usually a surface, and the laser will be directly reflected when it hits it, and the effect of dissipating the beam will be greatly reduced. Due to structural problems in this area, the blackening effect of this type will be poor, forming a bright spot, and the reflection effect will be aggravated, further affecting the light absorption efficiency. The inclination angle of the reflective surface around the center point is entirely controlled by the drill bit in the processing technology. When the beam hits it, the reflection path cannot be controlled. Summary of the invention

[0005] The object of the present invention is to provide a light trap for absorbing the target laser beam of the laser forward-scattering dust monitor, comprising two cavities, an incident cavity and a reflection cavity;

[0006] A reflecting surface is provided at the junction of the incident cavity and the reflecting cavity, for reflecting the incident light entering the incident cavity and then entering the reflecting cavity;

[0007] The surface of the reflective cavity is provided with a light absorbing surface and / or a reflective layer, the reflective layer is used to reflect light, and the light absorbing surface is used to absorb light.

[0008] A technical solution provided by this application also has the following technical features:

[0009] Preferably, in one embodiment of the present application, the reflective surface is obtained by setting a reflector to reflect the incident light entering the incident cavity into the reflective cavity, and the direction of the reflected light is controlled by the inclination angle of the reflector to ensure that the reflected light can hit the inner wall of the reflective cavity;

[0010] The inclination angle of the reflector is the angle between the incident direction of the laser and the reflecting surface, and is an acute angle; twice the complementary angle of the inclination angle, that is, the angle between the incident laser and the reflected laser, is the angle for achieving incident laser reflection adjustment.

[0011] Preferably, in an embodiment of the present application, the width H of the incident cavity intercepted on the plane where any straight line path of the incident light ray and the straight line path of the reflected light ray of the incident light ray are located is less than or equal to the width L of the reflective cavity.

[0012] Preferably, in an embodiment of the present application, a reflective layer is disposed on the surface of the reflective cavity for reflecting incoming reflected light.

[0013] Preferably, in an embodiment of the present application, a light absorbing surface is provided on the surface of the reflective cavity, and the light absorbing surface is used to absorb light.

[0014] Preferably, in an embodiment of the present application, the reflective surface is a plane or a concave surface.

[0015] Preferably, in an embodiment of the present application, the plane on which the straight line path of any incident light ray and the straight line path of the reflected light ray of the incident light ray are located, the width H of the intercepted incident cavity, the width L of the reflected cavity, the inclination angle α of the reflector, H>0, α is a radian value, and satisfies the following relationship:

[0016] when hour:

[0017]

[0018] when hour:

[0019] L≥H

[0020] when hour:

[0021]

[0022] Where:

[0023] The inclination angle α of the reflector is: the angle between the reflecting surface and the straight path of the incident light.

[0024] Preferably, in one embodiment of the present application, the straight path of the incident light along the central axis of the incident cavity and the straight path of the reflected light of the incident light, on the plane where the width H of the incident cavity and the width L of the reflection cavity are intercepted, the inclination angle α of the reflector, H>0, α is a radian value, satisfies the following relationship:

[0025] when hour:

[0026]

[0027] when hour:

[0028] L≥H

[0029] when hour:

[0030]

[0031] Where:

[0032] The inclination angle α of the reflector is: the angle between the reflecting surface and the straight path of the incident light.

[0033] Preferably, in one embodiment of the present application, the inclination angle of the reflective surface ranges from 55° to 67.5° to ensure that as much incident light as possible can enter the reflective cavity.

[0034] Preferably, in one embodiment of the present application, the inclination angle of the reflection surface is 60°.

[0035] Preferably, in an embodiment of the present application, the diameter of the reflective cavity is larger than the diameter of the incident cavity, so as to ensure that all the incident light enters the reflective cavity.

[0036] Preferably, in an embodiment of the present application, the depth of the reflection cavity should be as deep as possible to ensure a sufficient number of reflections.

[0037] Preferably, in an embodiment of the present application, the inclination angle of the reflector can be controlled by a groove or by a slope.

[0038] Preferably, in one embodiment of the present application, the inner wall of the incident cavity and / or the reflection cavity adopts a blackened thread structure to improve the diffuse reflection and light absorption effect;

[0039] Blackening treatment: By forming a thin film containing metal oxides, the surface has strong light absorption; for thread structures, the blackened surface will reduce the intensity of reflected light, especially in the visible light range;

[0040] Lower reflectivity: Blackening can make the metal surface appear darker (such as black or dark gray), thereby reducing the reflection of light, especially light from the front or at a shallow angle; the reflectivity of the black surface to visible light will be reduced to 5%-10%;

[0041] Enhanced light absorption: Black surfaces generally absorb more light energy, especially in the visible and near-infrared regions; therefore, a blackened threaded surface has a stronger light absorption capacity than an untreated smooth metal surface.

[0042] Preferably, in one embodiment of the present application, the reflective lens is preferably a lens with a light-absorbing coating, or an ordinary silver-plated lens can be used; if a blackened frosted metal sheet is to be used, the depth of the incident cavity should be as deep as possible.

[0043] Preferably, in one embodiment of the present application, the inclination angle α of the reflector refers to the angle between the reflective surface and the incident light, and the incident light is parallel to the inner surface and the center line or the center plane of the incident cavity;

[0044] On the vertical cross section, that is, the plane perpendicular to the reflection surface, and the plane divides the incident cavity and the reflection cavity, the width of the incident cavity is H, and the width of the reflection cavity is L; the width H of the incident cavity is less than or equal to the width L of the reflection cavity.

[0045] Preferably, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0046]

[0047] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0048] Preferably, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0049] L≥H

[0050] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0051] Preferably, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0052]

[0053] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0054] Preferably, in one embodiment of the present application, an optical fiber bundle is provided at the inlet or outlet of the reflection cavity.

[0055] Preferably, in an embodiment of the present application, an absorption layer composed of a black body material is disposed at the end of the incident cavity and / or the reflection cavity.

[0056] Preferably, in an embodiment of the present application, the reflective cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the reflective cavity is adjustable.

[0057] Preferably, in one embodiment of the present application, the incident cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the incident cavity is adjustable.

[0058] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0060] Figure 1 is a schematic diagram of a light trap of the present invention;

[0061] Figure 2 is a schematic AA cross-sectional view of a light trap of the present invention;

[0062] Figure 3 is a schematic diagram of an existing light trap;

[0063] Figure 4 is a schematic diagram of an existing light trap structure;

[0064] Figure 5 A schematic diagram of light incidence and reflection of a light trap of the present invention;

[0065] Figure 6 A schematic diagram of light incidence and reflection of a light trap of the present invention;

[0066] Figure 7 A schematic diagram of light incidence and reflection of a light trap of the present invention;

[0067] Components in the picture:

[0068] 1. Ontology

[0069] 2. Incident cavity

[0070] 3. Reflection cavity

[0071] 4. Reflective surface. DETAILED DESCRIPTION

[0072] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings. These implementation methods are only used to illustrate the present application, and are not intended to limit the present invention.

[0073] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0074] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0076] like Figure 1-2 , an optical trap for absorbing a target laser beam of a laser forward-scattered dust meter, wherein a main body 1 comprises two cavities, an incident cavity 2 and a reflection cavity 3;

[0077] A transparent window is provided at the entrance side of the incident cavity 2 to prevent dust from entering;

[0078] The incident cavity 2 and / or the reflection cavity 3 are connected to a dust blowing port, through which the dust accumulated inside for a long time is blown out by the injection of high-pressure gas after dust removal, thereby extending the service life and preventing the diffuse reflection of dust from affecting the laser absorption and guidance;

[0079] The shape and size of the body 1 are selected according to the calculation and experimental requirements of engineers in combination with specific applications, and the present invention does not limit this.

[0080] But at least: the volume space of the body 1 should have the size requirements that the space lock for setting the incident cavity 2 and the reflection cavity 3 meets;

[0081] The body is the main part of the light trap, designed as a closed or semi-closed structure that can accommodate the incident cavity and the reflection cavity; the main function of the body is to provide a stable environment for laser absorption and scattering;

[0082] According to the general requirements of opaque materials, it isolates external light interference to ensure that the laser can be absorbed to the maximum extent and reduce the impact of background light;

[0083] The function of the incident cavity is to introduce the light beam emitted by the laser after scattering, and guide the light beam to the inner wall of the reflective cavity through the reflective surface 4;

[0084] The incident cavity is designed to be circular or to match the structure required by the shape of the laser beam, so as to make full use of the space of the incident cavity and reduce the volume of the light trap; the inner wall is coated with a high light absorption rate, such as a black ceramic coating, to absorb the primary scattered light as much as possible;

[0085] A reflecting surface 4 is provided at the junction of the incident cavity 2 and the reflecting cavity 3;

[0086] If a reflector is provided, the incident light entering the incident cavity 2 is reflected into the reflecting cavity 3, and the direction of the reflected light is controlled by the inclination angle of the reflector to ensure that the reflected light can hit the inner wall of the reflecting cavity;

[0087] The reflector is set between the incident cavity and the reflective cavity. Its inclination angle is precisely calculated, which can guide the light beam to the inner wall of the reflective cavity in the best path to ensure the controllable light path. The addition of the reflector can prevent the light from escaping due to structural errors.

[0088] The function of the reflection cavity is to gradually guide the energy of the light beam to the absorption area or to the area that does not interfere with the instrument through multiple reflections; the inner wall material of the reflection cavity adopts multi-layer high light absorption coating and combines nanostructures (such as micro grooves) to further enhance the light absorption efficiency;

[0089] The incident cavity and the reflection cavity are opened on the body, and the optical path design forms a continuous light absorption channel; the incident cavity is responsible for receiving the guided light beam, and the reflection cavity guides it to the outside through multiple reflections;

[0090] This application can significantly reduce the background interference of light, improve the absorption efficiency of the light trap, and enhance the measurement accuracy of the laser forward scattering dust meter.

[0091] The inclination angle of the reflector is the angle between the incident direction of the laser and the reflecting surface, and is an acute angle; twice the complementary angle of the inclination angle, that is, the angle between the incident laser and the reflected laser, is the angle for achieving the reflection adjustment of the incident laser;

[0092] The light absorption efficiency of the present application is high, and all the laser light in the incident cavity enters the reflection cavity, and the absorption rate reaches 100%;

[0093] The inclination angle of the reflective surface of this application is adjustable to meet different application scenarios, match the use requirements of the laser forward scattering dust meter, and meet the absorption requirements under different technical requirements;

[0094] In particular: To improve the measurement accuracy, the influence of non-scattered light should be minimized, while the measurement target is the scattered light generated by the interaction between the laser beam and the dust particles;

[0095] The measurement of non-scattered light is difficult, or it is difficult to capture this target. In order to improve the measurement accuracy, multiple tests can be performed to compare the numerical differences:

[0096] The fluctuation of the numerical difference under the same inclination angle and the same working condition reflects the measurement accuracy of a single inclination angle, and this data is obtained under multiple inclination angles;

[0097] For the same working condition, the fluctuation of numerical values ​​at different inclination angles reflects the measurement accuracy at different inclination angles;

[0098] According to the accuracy requirements, the optimal value range of single inclination measurement accuracy is screened out;

[0099] The optical trap of the present application achieves an overall technical effect through incidence, reflection, and absorption. The cavity processing and setting cost is low, and the damage to the original structure is small, which is suitable for existing structural modification applications.

[0100] Specifically, in one embodiment of the present application, the width H of the incident cavity intercepted on the plane where any straight-line path of the incident light ray and the straight-line path of the reflected light ray of the incident light ray are located is less than or equal to the width L of the reflection cavity, thereby ensuring that the light beam can be effectively reflected and fully absorbed in the reflection cavity, reducing the possibility of reflected light escaping, and maximizing the light absorption efficiency of the laser beam, thereby improving the signal-to-noise ratio of scattered light and background light, thereby accurately measuring dust concentration.

[0101] Specifically, in one embodiment of the present application, a reflective layer is provided on the surface of the reflective cavity to reflect the reflected light entering; the reflected light is reflected and returned to the cavity multiple times to prevent the reflected light from escaping directly, thereby maximizing the utilization rate of the reflected light. The function of the reflective layer is to guide and control the path of the reflected light so that it is reflected and propagated in the reflective cavity until it is finally absorbed or scattered, thereby reducing unnecessary light loss and ensuring that the light passes through an appropriate path to improve the accuracy of the measurement.

[0102] Through the configuration of the high-reflective layer, the interference of background light is effectively reduced, the signal-to-noise ratio of the photoelectric detector is significantly improved, higher measurement accuracy and stability are achieved, and the high requirements of the laser forward-scattering dust meter for accuracy and reliability are met.

[0103] Specifically, in one embodiment of the present application, a light absorbing surface is provided on the surface of the reflective cavity, and the light absorbing surface is used to absorb light;

[0104] The light absorption surface is made of materials with high absorption performance, such as black anodized aluminum, black paint or silicon carbide coating, which can effectively absorb reflected light and prevent the light from being reflected back to the outside of the cavity again in the reflection cavity, thereby avoiding the interference of reflected light on the measurement signal; the light absorption surface completely absorbs the light entering the reflection cavity, thereby reducing the influence of light on the dust concentration measurement result;

[0105] During the implementation process, the light absorption surface can ensure that the reflected light can be completely absorbed after multiple reflections in the cavity, and no longer affect the external photoelectric detector; by absorbing these reflected lights, the interference of background light is avoided, the contrast between scattered light and background light is significantly improved, and the measurement accuracy and sensitivity of the laser forward scattering dust meter are effectively improved; in addition, this design can also reduce the optical loss caused by the reflected light not being effectively absorbed, and improve the overall light absorption efficiency of the light trap;

[0106] In terms of technical effects, the setting of the light absorption surface effectively reduces the excess light reflection in the cavity, ensures the signal-to-noise ratio during the measurement process, and reduces noise interference; improves the accuracy of dust concentration measurement, and enhances the stability and reliability of the equipment; enables the laser forward scattering dust meter to more accurately capture the scattered light generated by the interaction between dust particles and lasers, meeting the measurement needs in different working environments and dust concentration ranges.

[0107] Specifically, in one embodiment of the present application, the reflective surface is a plane or a concave surface;

[0108] The flat reflective surface can ensure that the laser light is reflected in a predetermined direction and ensure that the reflected light can be evenly propagated along the path inside the cavity;

[0109] The concave curved reflective surface can focus the incident light more closely, and by utilizing this focusing effect, the size requirement for the reflective cavity can be reduced, especially when the beam width of the incident cavity is large, which is particularly helpful in reducing the required width of the reflective cavity.

[0110] Enhance the reflection efficiency of light, so that the reflected light can be concentrated and sent into the reflection cavity, thereby improving the absorption and guidance of the light beam, and further enhancing the absorption effect of light;

[0111] In the implementation of the plane reflective surface, since its surface is a flat geometric shape, the reflection angle is accurately calculated according to the incident angle, which can effectively guide the light into the reflective cavity, thereby avoiding unnecessary light loss; the plane reflective surface is particularly suitable for guiding the laser beam, ensuring that the beam is transmitted in the reflective cavity according to the predetermined path;

[0112] The concave curved reflective surface design changes the propagation path of the reflected light through the bending effect of the curved surface, so that the reflected light can be guided to a specific direction or area; by reasonably designing the shape of the concave curved surface, the incident light can be effectively concentrated or dispersed; by setting the focusing point inside the reflective cavity or on the inner wall of the reflective cavity, the required size of the reflective cavity can be reduced; ensuring that the light enters the reflective cavity and is absorbed or guided to the external area after multiple reflections;

[0113] By setting a flat or concave reflecting surface, the direction and path of the reflected light can be adjusted according to specific application requirements; the flat reflecting surface can efficiently guide the incident light into the reflecting cavity, while the concave reflecting surface can further improve the reflection efficiency and light absorption effect by concentrating the light or changing the propagation path of the light, effectively improving the light absorption capacity, ensuring that the reflected light can be reflected multiple times in the reflecting cavity and finally absorbed, reducing the escape of reflected light, avoiding the influence of interference light on the measurement results, and significantly improving the measurement accuracy and signal-to-noise ratio of the laser forward scattering dust meter.

[0114] Specifically, in one embodiment of the present application, the inclination angle of the reflective surface ranges from 55° to 67.5° to ensure that as much incident light as possible can enter the reflective cavity.

[0115] Specifically, in one embodiment of the present application, the inclination angle of the reflection surface is 60°.

[0116] Specifically, in one embodiment of the present application, the diameter of the reflection cavity is larger than the diameter of the incident cavity, ensuring that all incident light enters the reflection cavity. This example is a simple and convenient application embodiment that does not require precise size calculations, such as selecting an inclination angle of 45°.

[0117] Specifically, in one embodiment of the present application, the depth of the reflection cavity should be as deep as possible to ensure a sufficient number of reflections so that the light beam can be absorbed by the combined absorption surface.

[0118] Specifically, in one embodiment of the present application, the inclination angle of the reflector can be controlled by a groove or by a slope.

[0119] Specifically, in one embodiment of the present application, the inner wall of the incident cavity and / or the reflection cavity adopts a blackened thread structure to improve the diffuse reflection and light absorption effect;

[0120] Blackening treatment: By forming a thin film containing metal oxides, the surface has strong light absorption; for thread structures, the blackened surface will reduce the intensity of reflected light, especially in the visible light range;

[0121] Lower reflectivity: Blackening can make the metal surface appear darker (such as black or dark gray), thereby reducing the reflection of light, especially light from the front or at a shallow angle; the reflectivity of the black surface to visible light will be reduced to 5%-10%;

[0122] Enhanced light absorption: Black surfaces generally absorb more light energy, especially in the visible and near-infrared regions; therefore, a blackened threaded surface has a stronger light absorption capacity than an untreated smooth metal surface.

[0123] Specifically, in one embodiment of the present application, the reflective lens is preferably a lens with a light-absorbing coating, or an ordinary silver-plated lens can be used; if a blackened frosted metal sheet is to be used, the depth of the incident cavity should be as deep as possible.

[0124] Specifically, in one embodiment of the present application, the inclination angle α of the reflector refers to the angle between the reflective surface and the incident light, and the incident light is parallel to the inner surface and the center line or the center plane of the incident cavity;

[0125] On the vertical cross section, that is, the plane perpendicular to the reflection surface, and the plane divides the incident cavity and the reflection cavity, the width of the incident cavity is H, and the width of the reflection cavity is L; the width H of the incident cavity is less than or equal to the width L of the reflection cavity.

[0126] Specifically, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0127]

[0128] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0129] Specifically, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0130] L≥H

[0131] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0132] Specifically, in one embodiment of the present application, the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflecting cavity is L, and the inclination angle α is expressed in radians. H>0, L value range is as follows:

[0133]

[0134] This means that all the incident light rays of the incident cavity enter the reflecting cavity.

[0135] Specifically, in one embodiment of the present application, an absorption layer composed of a black body material is provided at the end of the incident cavity or / and the reflection cavity;

[0136] Blackbody materials have excellent light absorption properties and can absorb almost all wavelengths of light, especially laser beams. By setting blackbody materials as absorption layers at the end of the incident cavity or the reflection cavity, the absorption efficiency of the laser beam can be further improved to ensure that the light does not escape from the cavity due to reflection or refraction, thereby reducing the interference of background light and improving the accuracy of dust concentration measurement.

[0137] In specific implementation, the setting of black body material as an absorption layer can play an important role in the following aspects:

[0138] Thorough absorption of light: Blackbody materials can efficiently absorb light incident into the cavity, ensuring that the light beam will not be reflected or refracted twice in the cavity, preventing the light from returning to the detector again, thereby reducing the impact of background light and ensuring the accuracy of the measurement data;

[0139] Reduce the escape of reflected light: Setting a black body material absorption layer at the end of the reflective cavity can effectively prevent light from escaping the cavity after multiple reflections in the reflective cavity, especially those that pass through complex paths; by absorbing these reflected lights, the black body material ensures that the light in the cavity is completely absorbed, reducing the error caused by the light not being effectively absorbed;

[0140] Improve light absorption efficiency: The black body material itself has extremely high light absorption, which can greatly improve the absorption efficiency of the light beam, making the light management of the reflection cavity and the incident cavity more effective; the introduction of highly absorbent materials can minimize the loss of light energy, thereby improving the overall performance of the laser forward scattered dust monitor, especially in low-concentration dust environments, and can more accurately detect weak scattered light;

[0141] By arranging a black body material absorption layer at the end of the incident cavity or the reflection cavity, the present invention can ensure that the laser light is completely absorbed after being reflected and scattered inside the cavity, and no light escapes, which greatly reduces the interference of background light on the photodetector and improves the signal-to-noise ratio and accuracy of the measurement; the high absorption characteristics of the black body material effectively prevent the influence of reflected light or scattered light in the cavity on the measurement signal, and significantly improves the accuracy and stability of the laser forward scattering dust meter in the dust concentration measurement process; in addition, the design of the black body material absorption layer enables the equipment to provide stable and reliable measurement results in various application scenarios, meet the needs of different dust concentrations and working environments, thereby achieving a significant improvement in measurement accuracy and optimization of background light suppression.

[0142] Specifically, in one embodiment of the present application, Figure 5-7 , the inclination angle α of the reflector refers to the angle between the reflection surface and the incident light, and the incident light is parallel to the inner surface and the center line or center plane of the incident cavity;

[0143] The width of the incident cavity is H, and the width of the reflection cavity is L, which is on the vertical section, that is, on the vertical plane of the reflection surface, and this plane divides the incident cavity and the reflection cavity.

[0144] Specifically, in one embodiment of the present application, Figure 5 , the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflection cavity is L, H>0, L value range is as follows:

[0145]

[0146] In this embodiment, the incident light of the upper limit has the minimum requirement to enter the reflective cavity after reflection;

[0147] The incident light near the lower limit enters the reflection cavity;

[0148] The incident light at the lower limit is considered to have no reflection or just enter the reflection cavity.

[0149] Specifically, in one embodiment of the present application, Figure 6 , the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflection cavity is L, H>0, L value range is as follows:

[0150] L≥H

[0151] In this embodiment, the incident light and the reflected light are perpendicular, and the incident cavity and the reflective cavity are also arranged perpendicularly, so that the incident light is guided into the reflective cavity.

[0152] Specifically, in one embodiment of the present application, Figure 7 , the inclination angle of the reflector is α, the width of the incident cavity is H, the width of the reflection cavity is L, H>0, L value range is as follows:

[0153]

[0154] In this embodiment, the incident light of the upper limit has the minimum requirement to enter the reflective cavity after reflection;

[0155] The incident light near the lower limit enters the reflection cavity;

[0156] The incident light at the lower limit is considered to have no reflection or just enter the reflection cavity.

[0157] Specifically, in one embodiment of the present application, the reflective cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the reflective cavity is adjustable;

[0158] The gap between the two sides of the split body, that is, the gap caused by the movement, is provided with a matching reflecting surface or absorbing layer, which is consistent with the structure of the inner wall of the reflecting cavity;

[0159] By controlling the size of the gap, the technical requirements for adjustment can be met;

[0160] The size of the reflection cavity can be flexibly adjusted according to specific application requirements, thereby optimizing the reflection path and absorption efficiency of the light. By adjusting the position of the side wall of the reflection cavity, the reflection angle and propagation path of the light inside the cavity can be changed, ensuring the effective management of the incident light and the reflected light, thereby improving the measurement accuracy of the laser forward scattering dust monitor in different working environments.

[0161] During implementation, the side wall of the reflective cavity is designed with an adjustable structure, and the position of the side wall can usually be easily adjusted by mechanical means, such as screw adjustment, slide rails, etc. This adjustment mechanism can provide an optimized reflective cavity size in different dust concentration ranges and application scenarios, thereby achieving more precise light control; for example, when the dust concentration is low, the size of the reflective cavity can be adjusted to increase the number of light reflections in the cavity;

[0162] The size of the reflective cavity increases: the total path length of the reflected light increases, and the number of reflections decreases;

[0163] The size of the reflective cavity increases: the total path length of the reflected light decreases, and the number of reflections increases;

[0164] Improve signal strength and signal-to-noise ratio; in high-concentration dust environments, the size of the reflective cavity can be adjusted to avoid interference from excessive reflected light and ensure the accuracy of the measurement results;

[0165] By designing the reflection cavity as a split structure and setting an adjustable side wall, the size of the reflection cavity can be flexibly adjusted in different application environments, thereby optimizing the path of the reflected light and the light absorption effect; the adjustable structure enables the reflection cavity to dynamically adapt to changes in dust concentration according to actual needs, improving the measurement adaptability and accuracy of the equipment under different working conditions; in addition, the adjustability of the reflection cavity size enhances the stability of the system, avoids measurement errors caused by too much or too little reflected light, and ensures the long-term stable operation of the laser forward scattering dust monitor;

[0166] This embodiment: can ensure that the laser forward scattering dust monitor can achieve the best background light suppression effect under various working conditions and provide accurate and stable dust concentration measurement data;

[0167] Realization of split structure and size adjustment of injection cavity:

[0168] 1. Split structure reflection cavity

[0169] The split structure of the reflective cavity means that the two side walls or multiple parts of the reflective cavity can be mechanically connected, disassembled or adjusted, which can flexibly meet the measurement requirements in different laser beam and scattered dust environments. Through the split structure, the size of the reflective cavity can be adjusted as needed to optimize the path and absorption efficiency of the reflected light.

[0170] The two side walls of the reflective cavity are composed of adjustable connecting parts, such as slide rails, spiral adjustment screws or other mechanical structures, so that the side walls can move within a certain range, thereby adjusting the width or height of the reflective cavity;

[0171] Use high-strength and sufficiently rigid materials (such as aluminum alloy, steel or plastic) to ensure structural stability during adjustment and to withstand stress from reflected light and mechanical adjustment;

[0172] The split cavity structure is manufactured using precision processing technology (such as CNC machining or laser cutting) to ensure the flatness and reflection efficiency of the cavity inner wall; the adjustment device needs to be precisely manufactured according to the design requirements to ensure that each adjustment component does not deviate during adjustment and maintain the light management accuracy inside the reflective cavity;

[0173] Adjusting the size of the sidewall gap can improve the reflection efficiency of the reflection cavity and optimize the path of the laser in the cavity, thereby improving the measurement accuracy;

[0174] During the processing, it is necessary to ensure the smoothness and reflective effect of the cavity surface to avoid uneven light scattering due to surface unevenness, which will affect the measurement results;

[0175] The design of the sidewall adjustment structure needs to ensure the matching accuracy between the moving parts to avoid unstable optical performance caused by too large or too small gaps;

[0176] 2. Reflective surface and its supporting absorption layer

[0177] The two side walls of the reflective cavity need matching reflective surfaces or absorption layers in the split structure to ensure effective reflection or absorption of light in the cavity, thereby reducing background light interference;

[0178] The inner wall of the reflective cavity is coated with a highly reflective material (such as aluminum, silver or gold-plated material) to ensure that the light can be efficiently reflected and propagated multiple times; the reflective surface can be made by spraying, filming or direct casting, and the material needs to have a high reflectivity to reduce the loss of reflected light;

[0179] An absorption layer is set in the reflection cavity, usually using black paint or black body material with high light absorption to absorb the unreflected light to the greatest extent and avoid background light from interfering with the measurement. The thickness and material type of the absorption layer should be adjusted according to the actual light intensity and beam path to achieve the best light absorption effect.

[0180] High reflectivity and high light absorption: The reflective surface can ensure that the light is fully reflected in the reflective cavity, while the absorption layer can effectively absorb the light to prevent the reflected light from interfering with the measuring instrument;

[0181] The design of the reflective surface and the absorption layer should be consistent. Whether it is a flat reflective cavity or a split structure reflective cavity, the layout and configuration of these layers should be ensured not to be affected by adjustments.

[0182] The selection of materials for the reflective surface and the absorption layer is crucial to the overall effect; the reflective layer should be made of metal materials with high reflectivity, while the absorption layer should be made of black coating or black body materials with high light absorption; the thickness of the materials and the coating process need to be strictly controlled;

[0183] When applying the absorption layer and the reflective surface coating, it is necessary to ensure that the coating is uniform, free of bubbles and cracks; otherwise, uneven coating may lead to inconsistent light reflection and absorption effects, thus affecting the measurement accuracy;

[0184] 3. Gap control and matching of reflective surface or absorption layer

[0185] The gaps on both sides of the split structure of the reflective cavity are an important factor in adjusting the size of the reflective cavity. By controlling the size of the gap, the size of the reflective cavity can be accurately adjusted to meet the needs of laser absorption and light reflection under different technical requirements; by reasonably setting the matching reflective surface or absorption layer of the gap, it can be ensured that the propagation path of the light is not unnecessarily affected;

[0186] The size of the gap should be adjusted according to the size of the reflective cavity, and ensure that the light is not accidentally reflected or scattered at the gap; the reflective surface or absorption layer on both sides of the gap needs to be consistent with the inner wall structure of other parts of the cavity to ensure uniform reflection or absorption of light;

[0187] The reflective surface or absorption layer designed at the gap must be consistent with the geometric shape of the inner wall of the cavity, so as to avoid the light being reflected or absorbed incorrectly at the gap and ensure the continuity and consistency of the light management inside the cavity;

[0188] By controlling the gap between the two sides of the reflective cavity, the reflective characteristics of the cavity can be flexibly adjusted so that the light can be fully reflected and absorbed in the cavity, thereby improving the accuracy of the measurement.

[0189] The reflective surface or absorption layer at the gap is consistent with the inner wall structure of the reflective cavity, ensuring that the light management is not affected and avoiding performance fluctuations caused by inconsistent structures;

[0190] During the manufacturing process, it is critical to ensure the accuracy of the adjustment gap of the reflective cavity; gaps that are too large or too small will affect the control of light in the reflective cavity, causing light loss or excessive reflection;

[0191] The matching reflective surface or absorption layer needs to match the structure of the rest of the cavity to avoid fluctuations in optical performance due to inconsistent coating thickness or material differences;

[0192] By designing the reflection cavity as a split structure and setting adjustable gaps on both sides, combined with highly reflective and highly light-absorbing materials, the size of the reflection cavity can be precisely adjusted to optimize the reflection path and absorption effect of light; this not only improves the measurement accuracy of the laser forward-scattering dust meter, but also enhances the adaptability and stability of the system; during the manufacturing process, it is necessary to precisely control the size of each component and the uniformity of the coating to ensure the efficiency of the reflective surface, absorption layer and adjustment mechanism in order to achieve the expected technical effect.

[0193] Specifically, in one embodiment of the present application, the incident cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the incident cavity is adjustable;

[0194] The gap between the two sides of the split body, that is, the gap caused by the movement, can be consistent with the structure of the inner wall of the incident cavity;

[0195] By controlling the size of the gap, the technical requirements for adjustment can be met;

[0196] Similarly, the gap of the incident cavity can also be adjusted accordingly; since the incident cavity is mainly used for beam guidance, the requirements are lower than those of the reflection cavity;

[0197] The split structure of the incident cavity can be composed of two or more units, which are assembled by mechanical connections such as screws, buckles, slide rails, etc. The side wall of each unit is adjustable, and the size of the incident cavity can be changed by controlling the change of its relative position; the adjustment mechanism of the side wall can adopt CNC screw drive, gear rack transmission, sliding and slot matching, etc.

[0198] In order to ensure that the side wall is adjustable, a design structure with precision threads or slide rails is usually adopted; through a rotating or sliding mechanism, the movement of the side wall within a certain range is controlled to change the effective width or height of the incident cavity; this design requires high precision to ensure the accuracy of adjustment;

[0199] By setting up the adjustment device, it is ensured that the movement of the two side walls can be precisely controlled, and the cavity size can be fine-tuned to meet the technical requirements of beam control and scattered light intensity measurement;

[0200] The adjustability of the split structure of the incident cavity enables the device to flexibly adjust the size of the cavity according to the dust concentration or the characteristics of the laser beam in different environments. For example, when the laser beam size is large, the size of the incident cavity can be enlarged to capture more light; when the dust concentration is low, the cavity size can be reduced to improve the measurement sensitivity.

[0201] The side wall part can be made of aluminum alloy, steel or high-strength plastic material, and the dimensional accuracy can be ensured by precision CNC machining; the mechanical connection part needs to be processed with high precision to ensure that the split structure can be adjusted smoothly after assembly;

[0202] The manufacture of the adjustment mechanism requires high-precision processing technology, and the tolerance of the thread or slide rail part should be controlled at the micron level to ensure that there is no jamming or deviation during adjustment;

[0203] The design and selection of connectors such as rails, threads, slots, etc. should ensure that the structure is stable and can withstand the wear after long-term use to avoid affecting the adjustment accuracy due to loose connections;

[0204] The adjustment accuracy of the side wall is crucial to the optical performance of the entire incident cavity. During the processing, it is necessary to ensure the processing accuracy of each adjustment component and conduct strict matching tests to avoid unevenness during the adjustment process.

[0205] The adjustment mechanism may shift due to vibration or friction during long-term use; therefore, the design should ensure that the adjustment mechanism has sufficient locking devices to avoid position drift after long-term use;

[0206] In order to avoid deformation of the side wall during adjustment, materials with higher rigidity and wear resistance can be selected, such as aluminum alloy, steel or composite materials;

[0207] 2. Clearance and consistency requirements on both sides of the split structure

[0208] In this embodiment, the gaps on both sides of the split structure are generated by adjusting the side walls; the size of the gaps directly affects the propagation and scattering of light in the incident cavity, so very precise design and manufacturing are required to ensure the uniformity and consistency of the gaps;

[0209] The gap between the two side walls is controlled by an adjustment device, and the accuracy of the gap needs to be ensured during the manufacturing process; the side walls can be processed by CNC machine tools so that the matching surface of each side wall reaches sufficient adjustment accuracy to ensure that the gap size does not change too much or unevenly during adjustment;

[0210] This consistent design not only improves light management efficiency, but also keeps the optical performance stable at different adjustment positions, effectively reducing errors caused by light scattering.

[0211] In order to ensure the gap accuracy, the size of the side wall and the size of the gap can be accurately controlled by CNC machining equipment and laser cutting technology during the manufacturing process;

[0212] When adjusting the sidewall, it is necessary to ensure that the change in the gap does not cause abnormal reflection or leakage of light; therefore, the friction and wear during the adjustment process should be considered in the design to ensure the stability of the adjustment device;

[0213] The design of the gap needs to ensure sufficient structural strength to avoid deformation due to material fatigue or long-term use, which may affect the optical performance;

[0214] By designing a split structure of the incident cavity with adjustable side walls and precisely controlling the gap between the two sides, the size of the incident cavity can be flexibly adjusted to meet the laser scattering measurement requirements in different application environments. During the manufacturing process, special attention should be paid to gap control, coating uniformity, and the accuracy of the adjustment device to ensure long-term stable operation and achieve the expected optical effect.

[0215] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A light trap for absorbing the target laser beam of a laser forward scattered dust monitor, characterized in that: It includes an incident cavity, a reflection cavity and a reflection surface; The reflecting surface is located at the junction of the incident cavity and the reflecting cavity, and is used to reflect the incident light entering the incident cavity and then enter the reflecting cavity; The surface of the reflective cavity is provided with a light absorbing surface and / or a reflective layer, the reflective layer is used to reflect light, and the light absorbing surface is used to absorb light.

2. A light trap as claimed in claim 1, characterized in that: The reflecting surface is a plane or a concave curved surface; the inner wall of the incident cavity and / or the reflecting cavity is provided with a blackened thread structure.

3. The light trap according to claim 1, characterized in that: The straight line path of any incident light ray and the straight line path of the reflected light ray of the incident light ray, on the plane where they are located, the width H of the intercepted incident cavity, the width L of the reflected cavity, the inclination angle α of the reflector, H>0, α is the radian value, and satisfy the following relationship: when hour: when hour: L≥H when hour: Where: The inclination angle α of the reflector is: the angle between the reflecting surface and the straight path of the incident light.

4. The light trap according to claim 1, characterized in that: The straight line path of the incident light along the central axis of the incident cavity and the straight line path of the reflected light of the incident light, on the plane where they are located, the width H of the incident cavity, the width L of the reflection cavity, the inclination angle α of the reflector, H>0, α is the radian value, and satisfy the following relationship: when hour: when hour: L≥H when hour: Where: The inclination angle α of the reflector is: the angle between the reflecting surface and the straight path of the incident light.

5. The light trap according to claim 1, characterized in that: The reflecting surface is obtained by setting a reflecting mirror, and the reflecting mirror is matched with a tilt adjustment column. The tilt angle is adjusted accordingly by moving the adjusting column.

6. The light trap according to claim 1, characterized in that: The inclination angle of the reflecting surface is in the range of 55°≦α≦67.5°.

7. The light trap according to claim 1, characterized in that: The inclination angle of the reflecting surface, in radians 8. The light trap according to claim 7, characterized in that: An optical fiber bundle is arranged at the entrance or the exit of the reflection cavity; an absorption layer composed of a black body material is arranged at the end of the incident cavity or / and the reflection cavity.

9. The light trap according to claim 1, characterized in that: The reflective cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the reflective cavity is adjustable.

10. The light trap according to claim 1, characterized in that: The incident cavity is a split structure, and at least one side wall of the split is adjustable, so that a size of the incident cavity is adjustable.

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