Optical path structure of dust sensor

Abstract

The utility model relates to an optical path structure of a dust sensor. The dust sensor light path structure comprises a light-emitting element, a light-receiving element and a shielding rod, the light-emitting element emits direct light which directly irradiates the light-receiving element; the shielding rod is arranged between the light-emitting element and the light-receiving element and shields direct light emitted by the light-emitting element. According to the utility model, the light-emitting element directly irradiates the light-receiving element, and the shielding rod is arranged between the light-emitting element and the light-receiving element; the shielding rod can shield direct light which is directly irradiated to the light receiving element by the light emitting element, so that scattered light can be smoothly irradiated to the light receiving element, and the detection precision of the dust sensor is ensured; the dust sensor using the optical path structure is more compact in structure and lower in manufacturing cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of dust sensor accessories, in particular to a dust sensor light path structure. BACKGROUND

[0002] The dust sensor is a device based on the scattering principle of light to detect dust in the air. When the dust in the air passes through the light generated by the light emitting element, the scattering phenomenon of light occurs. The intensity of the scattered light is proportional to the concentration of particulate matter, and the light element receives the scattered light and converts it into an electrical signal, thereby obtaining the concentration of particulate matter. Therefore, in the existing dust sensor, the light emitting element and the light receiving element are diagonally arranged; the light path emitted by the light emitting element and the light path received by the light receiving element intersect at a point; the intersection point coincides with the air flow channel. This is because if the light path emitted by the light emitting element and the light path received by the light receiving element are coaxial, the direct light of the light emitting element will mix with the scattered light and be received by the light receiving element. This results in the need for a larger space for the dust sensor to set up the intersecting light path, or the use of a separate lens to filter the direct light. The existing dust sensor is either very large or increases the production cost due to the separate lens. SUMMARY

[0003] The utility model aims at solving the above problems, and provides a dust sensor light path structure.

[0004] The technical scheme of the utility model is: a dust sensor light path structure comprises a light emitting element, a light receiving element and a shielding rod; the light emitting element emits direct light to the light receiving element; the shielding rod is arranged between the light emitting element and the light receiving element and shields the direct light emitted by the light emitting element; the shielding rod can shield the direct light emitted by the light emitting element to the light receiving element, so that the scattered light can smoothly reach the light receiving element and ensure the detection accuracy of the dust sensor; the dust sensor structure using the light path structure is more compact and has lower manufacturing cost.

[0005] Preferably, the side of the shielding rod facing the light receiving element is a circular arc surface, which can eliminate stray light caused by reflected light and achieve good S / N detection. The receiving signal of the scattered light is S, and the noise generated by the scattered light is N.

[0006] Further, the shielding rod is arranged in the air flow channel, which can realize smooth airflow without interfering with the internal airflow and improve the detection accuracy of the dust sensor.

[0007] Preferably, the dust sensor light path structure further comprises a lens A; the lens A is arranged between the light emitting element and the shielding rod; the light emitting element is at the focal point position of the lens A; the light emitted by the light emitting element forms parallel light through the lens A, which is conducive to dust detection.

[0008] Preferably, the dust sensor light path structure further comprises a lens B; the lens B is arranged between the shielding rod and the light receiving element; the light receiving element is located at the focal point of the lens B; the lens B can help the light receiving element to converge light, thereby ensuring the detection accuracy of the dust sensor.

[0009] Preferably, the lens A is provided with a horn A and a horn B coaxial with the lens A on both sides respectively; the lens B is provided with a horn C and a horn D coaxial with the lens B on both sides respectively; the horn A and the horn C are located on the side where the light emitting element is arranged and are arranged towards the light receiving element; the horn B and the horn D are located on the side where the light receiving element is arranged and are arranged towards the light emitting element; the horn A is conducive to guiding the light generated by the light emitting element to the lens A; the horn B can reduce the light emitted to the lens A; the horn C is conducive to guiding the light to the lens B; and the horn D reduces the light rebounding to the lens B.

[0010] Preferably, the horn B > horn A, which is conducive to guiding the light emitted by the light emitting element to the light receiving element; and the horn C > horn D, which is conducive to guiding the light to the light receiving element.

[0011] Further, a slit structure is arranged between the horn B and the shielding rod and is arranged towards the light receiving element; the slit structure is coaxial with the lens A; and the stray light emitted by the light emitting element is diffusely reflected in the slit structure, thereby reducing the stray light incident on the light receiving element.

[0012] The dust sensor light path structure of the utility model has the following advantages:

[0013] (1) The light emitting element of the utility model directly irradiates the light receiving element, and a shielding rod is arranged between the light emitting element and the light receiving element; the shielding rod can shield the direct light directly irradiated by the light emitting element to the light receiving element, so that the scattered light can smoothly irradiate the light receiving element, thereby ensuring the detection accuracy of the dust sensor; the dust sensor structure using the light path structure is more compact, and the manufacturing cost is lower;

[0014] (2) The side of the shielding rod towards the light receiving element is a circular arc surface, which can eliminate the stray light caused by the reflected light and realize good S / N detection; the receiving signal of the scattered light is S, and the noise generated by the scattered light is N; the shielding rod is arranged in the air circulation channel, so that smooth airflow can be realized without interfering with the internal airflow, and the detection accuracy of the dust sensor can be improved;

[0015] (3) The stray light emitted by the light emitting element is diffusely reflected in the slit structure, thereby reducing the stray light incident on the light receiving element. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1is the structure diagram of the dust sensor light path structure of the utility model in example one;

[0017] Figure 2 is the working principle diagram of the dust sensor light path structure of the utility model in example two;

[0018] Figure 3 is the working principle diagram of the dust sensor light path structure of the utility model in example three;

[0019] Figure 4 is the A-A sectional view of Figure 3 ;

[0020] Figure 5 is the B-B sectional view of Figure 4 ;

[0021] In the figure: 01. light, 02. dust particles, 03. air flow direction,

[0022] Light emitting element, 2. light receiving element, 3. shielding rod, 4. horn A, 5. horn B, 6. horn C, 7. horn D, 8. slit structure, 9. lens A, 10. lens B. DETAILED DESCRIPTION

[0023] Example one: refer to Figure 1 A dust sensor light path structure includes light emitting element 1, light receiving element 2, shielding rod 3; Light emitting element 1 emits direct light 01 to light receiving element 2; Shielding rod 3 is arranged between light emitting element 1 and light receiving element 2, and the direct light 01 emitted by light emitting element 1 is shielded; Shielding rod 3 can shield the direct light of light emitting element 1 to light receiving element 2, so that the scattered light can smoothly illuminate light receiving element 2, and the detection accuracy of the dust sensor is guaranteed; The dust sensor structure using the light path structure is more compact, and the manufacturing cost is lower.

[0024] Compared with the prior art, the utility model discloses that light emitting element 1 directly receives light receiving element 2, and shielding rod 3 is arranged between light emitting element 1 and light receiving element 2; The shielding rod 3 can shield the direct light of light emitting element 1 to light receiving element 2, so that the scattered light can smoothly illuminate light receiving element 2, and the detection accuracy of the dust sensor is guaranteed; The dust sensor structure using the light path structure is more compact, and the manufacturing cost is lower.

[0025] The shielding rod 3 is arranged in the air flow channel, can realize smooth airflow without interfering with the internal airflow, and can improve the detection accuracy of the dust sensor.

[0026] The dust sensor light path structure further comprises a lens A 9; the lens A 9 is arranged between the light emitting element 1 and the shielding rod 3; the light emitting element 1 is located at the focal point of the lens A 9; the light rays 01 emitted by the light emitting element 1 form parallel light rays 01 through the lens A 9, which is conducive to dust detection.

[0027] The dust sensor light path structure further comprises a lens B 10; the lens B 10 is arranged between the shielding rod 3 and the light receiving element 2; the light receiving element 2 is located at the focal point of the lens B 10; the lens B 10 can help the light receiving element 2 converge the light rays 01, ensuring the detection accuracy of the dust sensor.

[0028] The working principle of the embodiment is as follows: the light emitting element 1 directly irradiates the light receiving element 2, and the shielding rod 3 is arranged between the light emitting element 1 and the light receiving element 2; the shielding rod 3 can shield the direct light from the light emitting element 1 to the light receiving element 2, so that the scattered light can smoothly irradiate the light receiving element 2, ensuring the detection accuracy of the dust sensor; the dust sensor structure using the light path structure is more compact, and the manufacturing cost is lower.

[0029] Embodiment two: refer to Figure 2 Embodiment two is basically the same as embodiment one, and the same parts will not be repeated. The difference is that: the side of the shielding rod 3 facing the light receiving element 2 is a circular arc surface, which can eliminate stray light caused by reflected light and achieve good S / N detection. The receiving signal of the scattered light is S, and the noise generated by the scattered light is N.

[0030] Embodiment three: refer to Figures 3-5 Embodiment three is basically the same as embodiment two, and the same parts will not be repeated. The difference is:

[0031] The lens A 9 is provided with a horn mouth A 4 and a horn mouth B 5 coaxial with the lens A 9 on both sides; the lens B 10 is provided with a horn mouth C 6 and a horn mouth D 7 coaxial with the lens B 10 on both sides; the horn mouth A 4 and the horn mouth C 6 are located on the side of the light emitting element 1 and are arranged towards the light receiving element 2; the horn mouth B 5 and the horn mouth D 7 are located on the side of the light receiving element 2 and are arranged towards the light emitting element 1; the horn mouth A 4 is conducive to guiding the light rays 01 generated by the light emitting element 1 to the lens A 9; the horn mouth B 5 can reduce the emission of the light rays 01 through the lens A 9; the horn mouth C 6 is conducive to guiding the light rays 01 to the lens B 10; and the horn mouth D 7 reduces the rebound of the light rays 01 through the lens B 10.

[0032] The horn mouth B 5 and the shielding rod 3 are further provided with a slit structure 8 arranged towards the light receiving element 2; the slit structure 8 is coaxially arranged with the lens A 9; the stray light emitted by the light emitting element 1 is diffusely reflected in the slit structure 8, which can reduce the stray light incident on the light receiving element 2.

[0033] The horn mouth B 5 > horn mouth A 4, conducive to light emitting element 1 light 01 to the light receiving element 2 guide; horn mouth C 6 > horn mouth D 7, conducive to light 01 to the light receiving element 2 guide.

[0034] The working principle of the embodiment: the side of the shielding rod 3 towards the light receiving element 2 is a circular arc surface, which can eliminate the stray light caused by reflected light and achieve good S / N detection. The receiving signal of the scattered light is S, and the noise generated by the scattered light is N. The shielding rod 3 is arranged in the air flow channel, which can realize smooth airflow without interfering with the internal airflow, and can improve the detection accuracy of the dust sensor. The stray light emitted by the light emitting element 1 is diffusely reflected in the slit structure 8, which can reduce the stray light incident on the light receiving element 2.

[0035] Example four: example four and example one are basically the same, the same place is not repeated, the difference is: the light emitting element 1, the light receiving element 2 are provided with lens structure; the lens structure of the light emitting element 1 and the lens structure of the light receiving element 2 are coaxially arranged, the structure is more compact, and the cost is reduced.

[0036] The light emitting element 1 and the light receiving element 2 are surface mounted on the circuit board, which can eliminate the welding operation, reduce material loss and assembly time, and reduce production cost.

Claims

1. A dust sensor optical path structure, characterized in that: It includes a light-emitting element, a light-receiving element, and a shielding rod; the light-emitting element emits direct light to the light-receiving element; the shielding rod is arranged between the light-emitting element and the light-receiving element to block the direct light emitted by the light-emitting element.

2. The dust sensor optical path structure according to claim 1, characterized in that: The side of the shielding rod facing the light receiving element is an arc surface.

3. The dust sensor optical path structure according to claim 1, characterized in that: It also includes a lens A; the lens A is arranged between the light-emitting element and the shielding rod; the light-emitting element is at the focal position of the lens A.

4. The dust sensor optical path structure according to claim 1, characterized in that: It also includes a lens B; the lens B is arranged between the shielding rod and the light receiving element; the light receiving element is located at the focus position of the lens B.

5. The dust sensor optical path structure according to claim 1, characterized in that: Lens A is provided with a bell mouth A and a bell mouth B coaxial with lens A on both sides; lens B is provided with a bell mouth C and a bell mouth D coaxial with lens B on both sides; bell mouth A and bell mouth C are located on the side where the light-emitting element is located and are arranged toward the light-receiving element; bell mouth B and bell mouth D are located on the side where the light-receiving element is located and are arranged toward the light-emitting element.

6. The dust sensor optical path structure according to claim 1, characterized in that: Bell-mouth B > Bell-mouth A; Bell-mouth C > Bell-mouth D.

7. The dust sensor optical path structure according to claim 5, characterized in that: A slit structure is also provided between the horn mouth B and the shielding rod and is arranged toward the light receiving element; the slit structure is coaxially arranged with the lens A.

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