High-sensitivity linear light beam smoke fire detector

Abstract

A light source transmitting end and a signal receiving end are respectively arranged at the focal points of a first convex lens and a second convex lens, and an emitted light source is emitted outwards parallel to an optical axis when penetrating through the first convex lens, so that signal intensity reduction caused by light divergence is avoided; the signal receiving end can receive more signals focused by the second convex lens, so that the signal sensitivity of the signal receiving end is improved, the capability of capturing weak signals is enhanced, the probability of missing report caused by insufficient light convergence is reduced, and the detection accuracy of the smoke fire detector is integrally improved; the step surface and the clamping structure are arranged at the lens barrel, so that the first convex lens and the second convex lens can be quickly and stably fixed and quickly mounted, and the problem that the light source transmitting end and the signal receiving end cannot be accurately positioned at the focal points of the first convex lens and the second convex lens due to position deviation of the first convex lens and the second convex lens is avoided.

Description

Technical Field

[0001] This utility model belongs to the technical field of linear beam smoke detectors, and particularly relates to a high-sensitivity linear beam smoke detector. Background Technology

[0002] Linear beam smoke detectors are devices that use infrared technology to detect smoke. When smoke obscures the infrared light emitted by the smoke detector and the received infrared signal attenuates to a certain level, the alarm will sound. Current linear beam smoke detectors experience false alarms and missed alarms when the environment, smoke type, and concentration change. This is mainly due to insufficient focusing sensitivity of the linear smoke sensor, leading to significant attenuation of the infrared beam during long-distance transmission and reception, thus affecting the accuracy of smoke detection. Therefore, there is an urgent need for a technology to improve the focusing performance of linear beam smoke detectors to solve these problems. Utility Model Content

[0003] (I) Purpose of the utility model

[0004] To overcome the above shortcomings, the purpose of this utility model is to provide a high-sensitivity linear beam smoke detector to solve the technical problem that the existing linear beam smoke detectors have insufficient focusing sensitivity and are prone to false alarms and missed alarms.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the technical solution provided in this application is as follows:

[0007] A highly sensitive linear beam smoke detector includes: a housing, a main control board disposed within the housing, a light source emitting end disposed on the main control board for emitting infrared light, a signal receiving end for receiving reflected infrared light, two lens tubes respectively covering the front of the light source emitting end and the signal receiving end, a first convex lens disposed on the lens tube corresponding to the light source emitting end, the focal point of the first convex lens coinciding with the light source emitting end, and a second convex lens disposed on the lens tube corresponding to the signal receiving end, the focal point of the second convex lens coinciding with the signal receiving end. Each of the two lens tubes has a stepped surface at one end corresponding to the first and second convex lenses, abutting against the edges of the first and second convex lenses, and each edge has multiple elastic locking structures for engaging the edges of the convex lenses.

[0008] This application places the light source emitting end and the signal receiving end at the focal points of the first and second convex lenses, respectively. When the emitted light source passes through the first convex lens, it is emitted outward parallel to the optical axis, avoiding the signal intensity reduction caused by light divergence. The signal receiving end can receive more of the signal focused by the second convex lens, improving the signal sensitivity of the signal receiving end, enhancing the ability to capture weak signals, and reducing the probability of missed detection due to insufficient light convergence. Overall, it improves the detection accuracy of the smoke detector. In addition, by setting a stepped surface and a locking structure at the lens barrel, the first and second convex lenses can be fixed quickly and stably. This not only allows for quick installation of the first and second convex lenses, but also avoids the light source emitting end and the signal receiving end being unable to be accurately located at the focal points of the first and second convex lenses due to the positional misalignment of the first and second convex lenses, thus ensuring signal sensitivity.

[0009] In some embodiments, the engaging structure includes: an elastic portion connected at one end to the edge of the lens barrel and a limiting block protruding at the other end of the elastic portion.

[0010] In some embodiments, the radius of curvature of the first convex lens is R1 = 20 mm, and the focal length is f1 = 50 mm;

[0011] The optimized radius of curvature (R1 = 20mm) and focal length (f1 = 50mm) achieve the best match between the radius of curvature and the focal length, ensuring that the light rays are more parallel to the optical axis after passing through the lens, thus enhancing the signal strength and stability during long-distance transmission.

[0012] In some embodiments, the radius of curvature of the second convex lens is R2 = 30 mm, and the focal length is f2 = 60 mm;

[0013] The optimized radius of curvature (R2 = 30mm) and focal length (f2 = 60mm) achieve the best match between the ratio of radius of curvature to focal length, ensuring that light can be uniformly focused on the signal receiver, improving the ability to capture weak signals, and thus reducing the probability of missed detection.

[0014] In some embodiments, the surfaces of the first convex lens and the second convex lens are coated with an anti-reflective coating, wherein the thickness of the anti-reflective coating is approximately 0.2 μm;

[0015] The addition of an anti-reflective coating significantly reduces light reflection loss as it passes through the lens surface, improving light transmittance. The coating thickness (approximately 0.2 μm) is designed to ensure optimal optical performance (reflectivity reduced to less than 1%), further enhancing the detector's sensitivity and accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the high-sensitivity linear beam smoke detector of this utility model;

[0017] Figure 2 This is a cross-sectional view of the high-sensitivity linear beam smoke detector of this utility model.

[0018] Figure 3 This is a cross-sectional view of the faceplate of the high-sensitivity linear beam smoke detector of this utility model.

[0019] Figure 4 yes Figure 3 A magnified view of part A in the middle;

[0020] Figure 5 This is a schematic diagram of the optical path of a high-sensitivity linear beam smoke detector.

[0021] Figure label:

[0022] 1. Outer shell; 101. Face cover; 102. Engaging structure; 1021. Elastic part; 1022. Limiting block; 103. Stepped surface; 104. Bottom cover; 2. Lens barrel; 3. First convex lens; 4. Second convex lens; 5. Light source emitting end; 6. Signal receiving end. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0024] This utility model provides a high-sensitivity linear beam smoke detector, comprising: a housing 1, a main control board disposed within the housing 1, a light source emitting end 5 disposed on the main control board for emitting infrared light, a signal receiving end 6 disposed on the main control board for receiving reflected infrared light, two lens tubes 2 respectively covering the front of the light source emitting end 5 and the signal receiving end 6, a first convex lens 3 disposed on the lens tube 2 corresponding to the light source emitting end 5, the focal point of the first convex lens 3 coinciding with the light source emitting end 5, and a second convex lens 4 disposed on the lens tube 2 corresponding to the signal receiving end 6, the focal point of the second convex lens 4 coinciding with the signal receiving end 6. Each of the two lens tubes 2 has a stepped surface 103 at one end corresponding to the first convex lens 3 and the second convex lens 4, which abuts against the edge of the convex lens, and multiple elastic locking structures 102 are provided on the edges of each lens tube for engaging the edge of the convex lens.

[0025] Specifically, the outer casing 1 includes a front cover 101 and a bottom cover 104. The front of the front cover 101 is a transparent panel that allows infrared light to pass through. Specifically, the lens barrel 2 can be integrally formed with the front cover 101.

[0026] Specifically, after receiving the infrared optical signal, the main control board can determine whether there is smoke and thus determine if there is a fire.

[0027] Specifically, smoke detectors are equipped with batteries or connected to external power sources via wires. The existing internal structure of smoke detectors will not be described in detail here.

[0028] Specifically, the light source emitting end 5 is located at the focal point of the first convex lens 3. With this design, the light emitted by the light source emitting end 5 can propagate outward parallel to the optical axis after passing through the first convex lens 3. This design effectively reduces the degree of light divergence during transmission and ensures the intensity and stability of the infrared signal light.

[0029] The signal receiver 6 is located at the focal point of the second convex lens 4. Through this design, all the light rays passing through the second convex lens 4 can be concentrated to the signal receiver 6 in large quantities, which significantly enhances the signal receiving capability of the receiver.

[0030] Specifically, the engaging structure 102 includes: an elastic part 1021 connected to the edge of the lens barrel 2 at one end and a limiting block 1022 protruding from the other end of the elastic part 1021. The limiting block 1022 cooperates with the stepped surface 103 to limit the first and second convex lenses 3 and 4.

[0031] Preferably, the lens can be made of modified polymethyl methacrylate (PMMA) material with an optical transmittance >92% and a coefficient of thermal expansion <7×10^-5 / ℃. It has a low coefficient of thermal expansion and good weather resistance.

[0032] Preferably, in this application, the radius of curvature of the first convex lens 3 is set to R1 = 20mm, and the focal length is set to f1 = 50mm;

[0033] After optimizing the parameters of the first convex lens 3, the following technical effects are achieved:

[0034] Optimize the radius of curvature (R1 = 20mm):

[0035] Improved focusing accuracy: This enables the light rays from the light source emitting end 5 to form a highly parallel beam;

[0036] Adaptable to long-distance transmission: A smaller radius of curvature helps reduce light divergence, ensuring that infrared signals maintain high intensity and stability during long-distance transmission;

[0037] Focal length setting (f1 = 50mm)

[0038] Matching detector requirements: The 50mm focal length design can match the overall size of the detector, ensuring that the light has optimal parallelism after passing through the lens.

[0039] Preferably, in this application, the radius of curvature of the second convex lens 4 is R2 = 30 mm, and the focal length is f2 = 60 mm.

[0040] After optimizing the parameters of the second convex lens 4, the following technical effects are achieved:

[0041] Enhanced signal strength: The 60mm focal length design can concentrate more light onto the signal receiver, significantly improving the received signal strength.

[0042] Reduce false alarm rate: By optimizing the focal length, the receiver can more accurately identify smoke signals, thereby reducing the probability of false alarms and missed alarms.

[0043] Balancing Focus and Sensitivity: The 30mm radius of curvature design ensures focusing performance while also meeting the sensitivity requirements of the receiver.

[0044] Adaptable to various smoke conditions: A larger radius of curvature helps the receiver better capture smoke signals of different concentrations, improving the applicability of the detector.

[0045] Specifically, this application aims to minimize lens size and reduce material usage while ensuring unaffected focusing performance. For example:

[0046] The diameter of the first convex lens 3 is optimized to D1 = 40mm, and the thickness is T1 = 5mm;

[0047] The diameter of the second convex lens 4 is optimized to D2 = 50mm, and the thickness is T2 = 6mm.

[0048] By simplifying the structural design and optimizing the production process, production costs can be reduced by approximately 20%.

[0049] Preferably, the present application has an anti-reflective coating on the surfaces of the first convex lens 3 and the second convex lens 4, wherein the thickness of the anti-reflective coating is about 0.2 μm.

[0050] Specifically, the anti-reflective coating can be: MgF2 (magnesium fluoride): with a refractive index of approximately 1.38. Alternatively, the anti-reflective coating can be SiO2 (silicon dioxide): with a refractive index of approximately 1.46, exhibiting good chemical stability and weather resistance.

[0051] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A highly sensitive linear beam smoke detector, characterized in that, include: The enclosure (1) includes a main control board inside the enclosure (1), a light source emitting end (5) for emitting infrared light on the main control board, a signal receiving end (6) for receiving reflected infrared light, two lens barrels (2) respectively covering the front of the light source emitting end (5) and the signal receiving end (6), a first convex lens (3) on the lens barrel (2) corresponding to the light source emitting end (5), the focal point of the first convex lens (3) coinciding with the light source emitting end (5), and a second convex lens (4) on the lens barrel (2) corresponding to the signal receiving end (6), the focal point of the second convex lens (4) coinciding with the signal receiving end (6). Each of the two lens barrels (2) has a stepped surface (103) at one end corresponding to the first and second convex lenses (3, 4) that abuts against the edges of the first and second convex lenses (3, 4), and multiple elastic locking structures (102) for locking the edges of the first and second convex lenses (3, 4) are provided on the edges.

2. The high-sensitivity linear beam smoke detector according to claim 1, characterized in that, The engaging structure (102) includes: an elastic part (1021) connected at one end to the edge of the lens barrel (2) and a limiting block (1022) protruding at the other end of the elastic part (1021).

3. The high-sensitivity linear beam smoke detector according to claim 1, characterized in that, The radius of curvature of the first convex lens (3) is R1 = 20 mm, and the focal length is f1 = 50 mm.

4. The high-sensitivity linear beam smoke detector according to claim 1, characterized in that, The radius of curvature of the second convex lens (4) is R2 = 30 mm, and the focal length is f2 = 60 mm.

5. The high-sensitivity linear beam smoke detector according to any one of claims 1-4, characterized in that, The surfaces of the first convex lens (3) and the second convex lens (4) are coated with an anti-reflective coating, wherein the thickness of the anti-reflective coating is approximately 0.2 μm.

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