A single-source composite sensor

Abstract

This invention discloses a single-light-source composite sensor, comprising a housing with an air inlet and an air outlet, a control circuit board disposed within the housing, and a broadband light source, an infrared detector, and a photodetector disposed on the control circuit board. An inclined first filter is positioned in front of the broadband light source. This invention employs a broadband light source capable of emitting different wavelengths as a common light source, and places a first filter in front of the broadband light source. The first filter selectively reflects and transmits the light emitted by the broadband light source, selecting appropriate wavelengths for the detection of particulate matter and gases. This invention effectively reduces the size of the composite sensor and lowers power consumption.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, specifically relating to a single-light source composite sensor. Background Technology

[0002] As people's demands for miniaturized devices and environmental safety continue to increase, the demand for multi-functional sensors is also growing, as is the demand for multi-functional sensors that integrate different detection objects.

[0003] Existing integrated particulate and gas sensing modules are implemented by hardware connection of single particulate and gas sensors that already have sensing functions. The particulate sensor is based on the principle of light scattering and has an internal light source; while the gas sensor is based on the principle of non-dispersive infrared (NDIR) and also has an internal light source. In other words, the existing sensing modules have two light sources, which not only occupy a lot of space but also result in high power consumption. Summary of the Invention

[0004] The main objective of this invention is to provide a single-light source composite sensor to solve the problems of large size and high power consumption of existing integrated particulate matter and gas detection modules.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A single-light source composite sensor includes a housing with an air inlet and an air outlet, a control circuit board disposed within the housing, and a broadband light source, an infrared detector, and a photodetector disposed on the control circuit board. An inclined first filter is disposed in front of the broadband light source. Light emitted by the broadband light source within a specific wavelength range passes through the first filter and the gas to be measured and then enters the infrared detector. Light emitted by the broadband light source outside the specific wavelength range is reflected by the filter and scattered by particulate matter in the aerosol to be measured before entering the photodetector.

[0007] In one possible implementation, the housing includes a base plate and a top cover, the air inlet is disposed on the top cover, the air outlet is disposed on the base plate, the control circuit board is fixed on the base plate and has a through hole, the photodetector is disposed on one side of the through hole, and the air inlet, the through hole and the air outlet are coaxially arranged.

[0008] In one possible implementation, the circuit board is provided with an air chamber having an air inlet and an air outlet, and the broadband light source, the filter and the infrared detector are all disposed in the air chamber. The side wall of the air chamber is provided with a window for the light reflected by the first filter to pass through.

[0009] In one possible implementation, the air inlet and outlet of the air chamber are both provided with waterproof and breathable membranes.

[0010] In one possible implementation, the window is provided with a second filter.

[0011] In one possible implementation, the second filter can only allow light outside a specific wavelength range to pass through.

[0012] In one possible implementation, the air chamber is provided with at least one reflective inner wall, and the light passing through the first filter is reflected by the reflective inner wall onto the infrared detector.

[0013] In one possible implementation, the angle between the first filter and the broadband light source is 45°.

[0014] In one possible implementation, the specific wavelength range is greater than 1 μm.

[0015] In one possible implementation, the infrared detector is a single-channel or multi-channel infrared sensor.

[0016] The beneficial effects of adopting the above technical solution are as follows: This invention uses a broadband light source capable of emitting light of different wavelengths as a common light source, and places a first filter in front of the broadband light source. The first filter selectively reflects and allows the light emitted by the broadband light source to pass through, selecting appropriate wavelengths of light for the detection of particulate matter and gas respectively. This invention effectively reduces the size of the composite sensor and lowers power consumption. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the structure of a single-light source composite sensor provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is an exploded view of a single-light source composite sensor provided in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the control circuit board and air chamber in a single-light source composite sensor provided in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram of the layout of the gas chamber, broadband light source, infrared detector, photodetector, etc. in a single-light source composite sensor provided in Embodiment 1 of the present invention.

[0022] in:

[0023] 1. Housing; 11. Base plate; 111. Exhaust vent; 12. Top cover; 121. Air inlet; 2. Control circuit board; 21. Through hole; 3. Broadband light source; 4. Infrared detector; 5. Photodetector; 6. First filter; 7. Air chamber; 71. Air inlet; 72. Air outlet; 73. Window; 74. Reflective inner wall; 8. Waterproof and breathable membrane; 9. Second filter. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] In the description of this invention, it should be clearly stated that the terms "vertical," "lateral," "longitudinal," "front," "rear," "left," "right," "up," "down," and "horizontal," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are merely for the convenience of describing this invention. They do not imply that the device or element referred to must have a specific orientation or position, and therefore should not be construed as a limitation of this invention. The term "quantity" should also not be construed as a limitation of this invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] It should be understood that each element of the apparatus or each step of the method can be described using apparatus terminology or method terminology. Such terms can be replaced where necessary to clarify the implicit broad scope of the invention. By way of example only, it should be understood that all steps of a method can be disclosed as actions, means of taking said actions, or elements causing said actions. Similarly, each element of the apparatus can be disclosed as a physical element or an action facilitated by said physical element. By way of example only, the disclosure of "connector" should be understood to cover the disclosure of the "connection" action, whether or not it is explicitly discussed—and conversely, if the "connection" action is disclosed, this disclosure should be understood to cover the disclosure of "connector" and even "means for connection." These alternative terms used for each element or step should be understood to be explicitly included in the specification.

[0028] Example 1

[0029] Embodiment 1 of the present invention provides a single-light source composite sensor, such as... Figure 1-4 As shown, the device includes a housing 1 with an air inlet 121 and an air outlet 111, a control circuit board 2 disposed inside the housing 1, and a broadband light source 3, an infrared detector 4, and a photodetector 5 disposed on the control circuit board 2. An inclined first filter 6 is disposed in front of the broadband light source 3. Light emitted by the broadband light source 3 within a specific wavelength range passes through the first filter 6 and the gas to be tested and then enters the infrared detector 4. Light emitted by the broadband light source 3 outside the specific wavelength range is reflected by the filter and scattered by the particulate matter in the aerosol to be tested before entering the photodetector 5.

[0030] By adopting the above technical solution, this invention uses a broadband light source 3 that can emit light of different wavelengths as a common light source, and sets a first filter 6 in front of the broadband light source 3. The first filter 6 selectively reflects and allows the light emitted by the broadband light source 3 to pass through, selecting appropriate wavelengths of light for the detection of particulate matter and gas respectively. This invention effectively reduces the size of the composite sensor and lowers power consumption.

[0031] Specifically, the specific wavelength range is greater than 1 μm (1000 nm). That is to say, light emitted by the broadband light source 3 with a wavelength greater than 1000 nm will pass through the first filter 6 for gas detection; light emitted by the broadband light source 3 with a wavelength less than or equal to 1000 nm will be reflected by the first filter 6 for particulate matter detection.

[0032] The first filter 6 is inclinedly disposed in front of the broadband light source 3, and the angle between the first filter 6 and the light emitted by the broadband light source 3 is preferably 45°.

[0033] In one embodiment, such as Figure 1-2 As shown, the housing 1 includes a base plate 11 and a top cover 12. An air inlet 121 is disposed on the top cover 12, and an exhaust vent 111 is disposed on the base plate 11. The control circuit board 2 is fixed to the base plate 11 and has a through hole 21. The photodetector 5 is disposed on one side of the through hole 21. The air inlet 121, the through hole 21, and the exhaust vent 111 are coaxially arranged, forming a flow path from the external environment → air inlet 121 → through hole 21 → exhaust vent 111 → external environment.

[0034] Furthermore, the circuit board is provided with an air chamber 7, which has an air inlet 71 and an air outlet 72. The broadband light source 3, the first filter 6 and the infrared detector 4 are all disposed in the air chamber 7. The side wall of the air chamber 7 is provided with a window 73 for the light reflected by the first filter 6 to pass through.

[0035] In addition, a second filter 9 is provided on the window 73. The second filter 9 can only allow light outside a specific wavelength range (i.e., light reflected by the first filter 6).

[0036] Preferably, the wavelength of the light passing through the second filter 9 is 650nm, 850nm or 940nm.

[0037] Preferably, when the infrared detector 4 does not integrate an infrared filter, the light passing through the first filter 6 is narrowband infrared light with a wavelength greater than 1 μm and a half-width of no more than 200 nm; when the infrared detector 4 integrates an infrared filter, the light passing through the first filter 6 is all light with a wavelength greater than 1 μm emitted by the broadband light source 3.

[0038] like Figure 4 As shown, the air chamber 7 contains a reflective inner wall 74 at a certain angle to the infrared detector 4 and the broadband light source 3. There can be one or more such inner walls to ensure that the light passing through the first filter 6 is reflected by the reflective inner wall 74 before illuminating the infrared detector 4. Furthermore, the reflective inner wall 74 of the air chamber 7 is provided with a high-reflectivity mirror coating, such as silver or copper.

[0039] Furthermore, the air inlet 71 and air outlet 72 of the gas chamber 7 are both provided with waterproof and breathable membranes 8 to prevent particulate matter from entering the gas and affecting gas detection.

[0040] Gases and aerosols from the external environment diffuse into the composite sensor through the air inlet 121 and the through-hole 21 on the control circuit board 2, filling the space between the photodetector 5 and the second filter 9 with aerosols. At the same time, gas enters the air chamber 7 through the waterproof and breathable membrane 8 on the air inlet 71 of the air chamber 7.

[0041] The light emitted by the broadband light source 3 with a wavelength greater than 1000nm passes through the first filter 6 and the gas in the gas chamber 7, and is reflected by the inner wall of the gas chamber 7 to the infrared detector 4. The infrared detector 4 converts the received light signal into an electrical signal, and the signal processing module on the control circuit board 2 analyzes and processes the electrical signal to obtain the gas concentration.

[0042] The light emitted by the broadband light source 3 with a wavelength of less than or equal to 1000nm is reflected by the first filter 6, passes through the second filter 9, and then illuminates the aerosol between the photodetector 5 and the second filter 9. After being scattered by the particles in the aerosol, the light is received by the photodetector 5, which generates an electrical signal. The signal processing module on the control circuit board 2 analyzes and processes the electrical signal to obtain the particle concentration.

[0043] This invention employs a broadband light source 3 capable of emitting light of different wavelengths as a common light source, and places a first filter 6 in front of the broadband light source 3. The first filter 6 selectively reflects and allows the light emitted by the broadband light source 3 to pass through, selecting appropriate wavelengths of light for the detection of particulate matter and gas. Because there is only one light source, the size of the composite sensor is effectively reduced, and power consumption is lowered.

[0044] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A single-light source composite sensor, characterized in that, The device includes a housing with an air inlet and an air outlet, a control circuit board disposed within the housing, and a broadband light source, an infrared detector, and a photodetector disposed on the control circuit board. An inclined first filter is disposed in front of the broadband light source. Light emitted by the broadband light source within a specific wavelength range passes through the first filter and the gas to be tested before entering the infrared detector. Light emitted by the broadband light source outside the specific wavelength range is reflected by the filter and scattered by the particulate matter in the aerosol to be tested before entering the photodetector. The housing includes a bottom plate and a top cover. The air inlet is located on the top cover, and the air outlet is located on the bottom plate. The control circuit board is fixed on the bottom plate and has a through hole. The photodetector is located on one side of the through hole. The air inlet, the through hole, and the air outlet are coaxially arranged.

2. The single-light source composite sensor according to claim 1, characterized in that, The circuit board is provided with an air chamber having an air inlet and an air outlet. The broadband light source, the filter and the infrared detector are all located in the air chamber. The side wall of the air chamber is provided with a window for the light reflected by the first filter to pass through.

3. A single-light source composite sensor according to claim 2, characterized in that, The air chamber is equipped with waterproof and breathable membranes at both the air inlet and outlet.

4. A single-light source composite sensor according to claim 2, characterized in that, The window is equipped with a second filter.

5. A single-light source composite sensor according to claim 4, characterized in that, The second filter can only allow light outside a specific wavelength range to pass through.

6. A single-light source composite sensor according to claim 4, characterized in that, The air chamber is provided with at least one reflective inner wall, and the light passing through the first filter is reflected by the reflective inner wall onto the infrared detector.

7. A single-light source composite sensor according to claim 1, characterized in that, The angle between the first filter and the broadband light source is 45°.

8. A single-light source composite sensor according to claim 1, characterized in that, The specific wavelength range is greater than 1 μm.

9. A single-light source composite sensor according to claim 1, characterized in that, The infrared detector is a single-channel or multi-channel infrared sensor.

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