Foreign matter detection sensor and air purifier
By designing the light source components and beam adjustment devices, and utilizing collimation and total reflection technologies, the false alarm problem of detecting clogging in the primary filter of indoor air purifiers has been solved, achieving high-precision and efficient foreign object detection while reducing costs and light loss.
Patent Information
- Application Number
- CN202520587455.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2026-01-20
- Estimated Expiration
- 2035-03-31
AI Technical Summary
Existing indoor air purifiers are prone to false alarms when detecting a clogged primary filter, and adding an infrared LED and PD receiver combination will increase costs and cause light interference.
It employs a light source assembly, a photosensitive assembly, and first and second beam adjustment components. The first beam adjustment component adjusts the light into a strip-shaped parallel beam. By utilizing collimation and total internal reflection technology, the detection range is expanded and false alarms are reduced.
It improves the accuracy and range of foreign object detection, reduces false alarms, reduces light loss, facilitates maintenance, and enhances the reliability of detection.
Smart Images
Figure CN223815440U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to sensor technical field especially relates to a foreign matter detection sensor and air purifier. BACKGROUND
[0002] The indoor air purifier is a kind of equipment for improving indoor air quality, its inside is usually provided with primary filter screen, for filtering out the bulk foreign matter visible to naked eye in air, such as pet hair, clothing hair and debris etc.
[0003] With the long time use of indoor air purifier, when the foreign matter on primary filter screen accumulates to certain thickness, thereby affecting the purification effect of primary filter screen, the existing indoor air purifier is generally provided with infrared LED and PD receiver at both ends of primary filter screen, whether primary filter screen is blocked is judged according to whether the infrared signal of infrared LED can be received by PD receiver.This mode has the disadvantage that the light emitted by infrared LED is linear, and the coverage is very limited, if only a part of the area of primary filter screen is blocked by the foreign matter with larger volume, and the light emitted by infrared LED is just blocked, then PD receiver will still judge that primary filter screen is completely blocked, thereby leading to false alarm.Some indoor air purifiers select to install multiple groups of infrared LED and PD receiver to solve this problem, but this will lead to significant increase in cost, and since light is scattered and reflected on foreign matter, mutual interference between each group of sensors occurs. SUMMARY
[0004] In order to overcome the shortcomings mentioned in the background art, the present application provides a foreign matter detection sensor and air purifier.
[0005] A foreign matter detection sensor, characterized in that it comprises a light source assembly, a photosensitive assembly, a first light beam adjusting member and a second light beam adjusting member, the photosensitive assembly is used for receiving light signals, the first light beam adjusting member is used for adjusting the light emitted by the light source assembly into a strip-shaped parallel light beam, the first light beam adjusting member comprises a convex surface, the convex surface is used for collimating the light emitted by the light source assembly to form a collimated light beam, the light emitted by the light source assembly directly irradiates on the convex surface, and the second light beam adjusting member is used for adjusting the strip-shaped parallel light beam into a light spot irradiating on the photosensitive assembly.
[0006] Further, the light source assembly is arranged opposite to the convex surface, and the light source assembly is arranged at the focal point position of the convex surface.
[0007] Further, the first light beam adjusting member and the second light beam adjusting member are both solid lenses, the first light beam adjusting member further comprises a first optical surface and a second optical surface, the first optical surface is used for reflecting the collimated light beam, the collimated light beam passes through the second optical surface after being reflected by the first optical surface to form the strip-shaped parallel light beam, the first light beam adjusting member as a whole has a triangular structure, wherein the convex surface, the first optical surface and the second optical surface are respectively three sides of the triangle, the first optical surface is provided with a stepped structure, the stepped structure comprises connecting surfaces and reflection inclined surfaces, the connecting surfaces connect adjacent reflection inclined surfaces, the reflection inclined surfaces are used for reflecting the collimated light beam, and an incident angle β of the collimated light beam on the reflection inclined surface is greater than a critical angle.
[0008] Further, an angle θ between an axis of the convex surface and the first optical surface is less than 45°.
[0009] Further, a direction of the collimated light beam is a first direction, a direction of light after being reflected by the first optical surface is a second direction, a projection of the first optical surface on a plane perpendicular to the first direction can completely cover the collimated light, and a projection of the second optical surface on a plane perpendicular to the second direction can completely cover the light beam after being reflected by the first optical surface.
[0010] Further, the incident angle β of the collimated light beam on the reflection inclined surface is equal to 45°.
[0011] Further, after being reflected by the reflection inclined surface of the first optical surface, a direction of the collimated light beam is perpendicular to the second optical surface.
[0012] Further, the first light beam adjusting member and the second light beam adjusting member have the same structure, and are arranged in mirror symmetry or central symmetry.
[0013] Further, the first light beam adjusting member and the second light beam adjusting member have the same structure, and are arranged in mirror symmetry or central symmetry.
[0014] An air purifier comprising a primary filter screen and the foreign matter detection sensor of any one of the preceding claims, the light source assembly and the first light beam adjusting member being located at one end of the primary filter screen, the photosensitive assembly and the second light beam adjusting member being located at the other end of the primary filter screen, and the first light beam adjusting member and the second light beam adjusting member being located at the air inlet side of the primary filter screen.
[0015] Advantages of the present application:
[0016] 1、The first light beam adjusting member adjusts the light emitted by the light source assembly into a strip-shaped parallel light beam, so that the detection range is increased without increasing the light source assembly and the photosensitive assembly, the detection accuracy of the foreign matter detection sensor is improved, and false reporting of the sensor is effectively avoided.
[0017] The other technical solutions of the present application can also achieve the following technical effects:
[0018] 2、The incident angle β of the parallel light beam on the reflection inclined surface is greater than the critical angle, so that total reflection of the light occurs, light loss is reduced, the intensity and irradiation distance of the light are ensured, and the light can cross the screen, thereby providing a guarantee for signal reception of the photosensitive assembly.
[0019] 3、The included angle θ between the collimated light beam and the first light beam adjusting member is less than 45°, so that the irradiation width of the light beam is increased after reflection of the collimated light beam on the reflection inclined surface, the detection range is improved, and false reporting of the sensor is reduced.
[0020] 4、The incident angle β of the collimated light beam on the reflection inclined surface of the first light beam adjusting member is equal to 45°, so that the collimated light beam is reflected perpendicularly after being irradiated on the reflection inclined surface, and the light is vertically redirected.
[0021] 5、The first shell and the second shell are convenient to disassemble, so that internal parts are convenient to overhaul and replace, and the maintenance efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 is a perspective view of the foreign matter detection sensor disclosed by the present application in a use state;
[0023] Figure 2 is an explosion schematic view of the present application;
[0024] Figure 3 is a schematic view of the light source assembly irradiating light and light reflection of the present application;
[0025] Figure 4 is a perspective view of the present application Figure 3 is an enlarged schematic view of the perspective structure at A of the present application.
[0026] In the attached figures, the following are the reference numerals: 1. Light source assembly; 2. Photosensitive assembly; 3. First beam adjustment component; 301. Convex surface; 302. First optical surface; 303. Second optical surface; 4. Second beam adjustment component; 5. First housing; 501. Mounting plate; 502. First cover plate; 503. Second cover plate; 6. Second housing; 601. Fixing plate; 602. Third cover plate; 603. Fourth cover plate. Detailed Implementation
[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0028] A foreign object detection sensor, such as Figures 2-3 As shown, the air purifier includes a light source assembly 1, a photosensitive assembly 2, a first beam adjuster 3, and a second beam adjuster 4. The photosensitive assembly 2 receives light signals. When the photosensitive assembly 2 receives a light signal emitted by the light source assembly 1, and the intensity of the received light signal exceeds a set value, the foreign object detection sensor determines that the air purifier's filter does not need cleaning and can continue to be used. When the intensity of the light signal emitted by the light source assembly 1 received by the photosensitive assembly 2 is lower than the set value, the foreign object detection sensor determines that the air purifier's filter is severely clogged, and at this time, the sensor issues an alarm to remind the user to clean the filter in time. The first beam adjuster 3 is used to adjust the light emitted by the light source assembly 1 into a strip-shaped parallel beam. The first beam adjuster 3 includes a convex surface 301, which is used to collimate the light emitted by the light source assembly 1, so that the light forms a collimated beam. The light source assembly 1 is arranged directly opposite the convex surface 301, and the light source assembly 1 is located at the focal position of the convex surface 301, so that the light emitted by the light source assembly 1 can form a parallel collimated beam after passing through the convex surface 301. The light emitted by the light source assembly 1 directly illuminates the convex surface 301. "Direct illumination" means that only air exists between the light source assembly 1 and the convex surface 301. The light emitted by the light source assembly 1 passes only through the air medium when it illuminates the convex surface 301, and is then collimated into a beam. The first beam adjuster 3 and the second beam adjuster 4 are identical and mirror-symmetrical solid lenses. The second beam adjuster 4 is used to adjust the strip-shaped parallel beam to form a light spot illuminating the photosensitive assembly 2. The first beam adjuster 3 expands the illumination range of the beam, while the second beam adjuster 4 can receive the expanded beam and transmit the light signal to the photosensitive assembly 2. This allows for an expansion of the beam detection range at the screen without increasing the number of first beam adjusters 3 and second beam adjusters 4, improving detection accuracy and effectively avoiding false alarms from the sensor.
[0029] like Figure 3 As shown, the first beam adjustment element 3 also includes a first optical surface 302 and a second optical surface 303. The first optical surface 302 is tilted downward to the left overall. The term "downward to the left" is used for ease of description and is based on... Figure 3The description of the component directions is shown in the figure. The first light beam adjusting member 3 is in a triangular structure as a whole, the convex surface 301, the first optical surface 302 and the second optical surface 303 can be regarded as three sides of the triangle, and it should be noted that the above-mentioned "triangular structure" is actually not a standard triangle, but a triangle-like structure, wherein the first optical surface 302 is the longest side of the triangle. The first optical surface 302 is used to reflect the collimated light beam adjusted by the convex surface 301, and the collimated light beam passes through the second optical surface 303 after being reflected by the first optical surface 302 and forms a strip-shaped parallel light beam. Among them, the collimated light beam is towards the first optical surface 302, the direction of the collimated light beam is called the first direction, and the direction of the collimated light beam changes after being reflected by the first optical surface 302. The projection of the first optical surface 302 in the direction perpendicular to the first direction can completely cover the collimated light, and the projection of the second optical surface 303 in the direction perpendicular to the second direction can completely cover the light beam reflected by the first optical surface 302, that is, the first optical surface 302 can receive all the light passing through the convex surface 301, and the second optical surface 303 can receive all the light reflected by the first optical surface 302, which ensures the utilization rate of light. Moreover, the irradiation direction of the collimated light beam adjusted by the convex surface 301 after being reflected by the first optical surface 302 is perpendicular to the second optical surface 303, thereby reducing the loss caused by the refraction of light at the second optical surface 303, and further ensuring the utilization rate of light.
[0030] Reference Figure 3 And Figure 4 The first optical surface 302 is provided with a stepped structure, the stepped structure includes a connecting surface and a reflection inclined surface, the connecting surface and the reflection inclined surface have different inclination angles, the connecting surface connects adjacent reflection inclined surfaces, and the collimated light beam is only irradiated on the reflection inclined surface of the first optical surface 302 and is reflected by the reflection inclined surface. The incidence angle β of the collimated light beam on the reflection inclined surface is greater than the critical angle, and the external air and the solid lens are respectively the optical rare medium and the optical dense medium, so that the light beam is totally reflected on the reflection inclined surface, thereby reducing the loss of light. Moreover, the incidence angle β of the collimated light beam on the reflection inclined surface of the first optical surface 302 is equal to 45°, that is, the incidence angle β of the collimated light beam on the reflection inclined surface is equal to 45° and greater than the critical angle, so that the collimated light beam can be perpendicularly reflected by 90° after being irradiated on the reflection inclined surface of the first optical surface 302, and the reflection belongs to total reflection.
[0031] Reference Figure 3As shown, the angle θ between the collimated light beam and the first optical surface 302 is less than 45°, because the width of the collimated light beam depends on the length of the area where the convex surface 301 receives the light rays, and as long as the angle θ between the collimated light beam and the first optical surface 302 is less than 45°, the width of the light beam after being reflected by the reflecting slope of the first optical surface 302 is necessarily greater than that before being reflected by the reflecting slope, so that the angle θ between the collimated light beam and the first optical surface 302 is less than 45°, which can increase the width of the light rays reflected by the first optical surface 302, thereby increasing the detection range and improving the detection accuracy. Since the size of the critical angle depends on the refractive index of the lens material, as long as a lens with appropriate material is selected, the incident angle β of the collimated light beam on the reflecting slope can be equal to 45° or greater than the critical angle, and the angle θ between the collimated light beam and the first optical surface 302 is also less than 45°, that is, the light rays not only undergo perpendicular reflection and total reflection, thereby reducing light loss, but also increase the detection range and improve the detection accuracy.
[0032] The sensor of the present application is applied to an air purifier, and in use, the light source assembly 1 and the photosensitive assembly 2 are in an open state, at which time the light source assembly 1 emits light and irradiates the convex surface 301. When the light contacts the convex surface 301, the convex surface 301 shapes the scattered light rays, so that the light rays are adjusted to be collimated light beams after passing through the convex surface 301, which irradiate on the stepped structure of the first optical surface 302. At this time, since the incident angle β of the collimated light beam on the reflecting slope is greater than the critical angle, the reflecting slope of the stepped structure totally reflects the collimated light beam, and when the light undergoes total reflection, refraction does not occur, thereby reducing light loss. Moreover, since the angle θ between the collimated light beam and the first optical surface 302 is less than 45°, and the incident angle β of the collimated light beam on the reflecting slope is not only greater than the critical angle but also equal to 45°, the collimated light beam is perpendicularly reflected after irradiating on the reflecting slope of the first optical surface 302, and the reflection is not only total reflection but also makes the width of the reflected light rays greater, that is, the light rays are 90° turned and the width of the light rays is widened at the same time of total reflection, thereby improving the detection range.
[0033] When the strip-shaped parallel light beam passes through the second optical surface 303, the strip-shaped parallel light beam is located at the air inlet side of the screen of the air purifier, and detects foreign matters on the screen, wherein the strip-shaped parallel light beam vertically penetrates into the second light beam adjusting member 4 when irradiated, contacts the stepped structure of the second light beam adjusting member 4 and is reflected again, the reflected light rays pass out of the second light beam adjusting member 4 and converge on the photosensitive assembly 2 to form a light spot, and the photosensitive assembly 2 detects the intensity of the light signal, so that the foreign matter detection sensor judges whether the filter screen needs to be cleaned.
[0034] Because the light at the screen of the air purifier is a strip parallel light beam, the light beam covers the air inlet side of the screen, when the light sensitive component 2 detects the light signal, if the screen of the air purifier has larger foreign matters in a local range, the strip parallel light beam will not be completely blocked by the foreign matters, and the light sensitive component 2 can still receive the light signal, if the light signal intensity received by the light sensitive component 2 is still higher than the set value, the sensor will not issue an alarm to remind the user to clean the filter screen, avoiding the occurrence of false alarm and improving the detection accuracy; when the filter screen of the air purifier is used for a long time, the filter screen is seriously blocked by foreign matters, causing the light signal intensity received by the light sensitive component 2 to be lower than the set value, the foreign matter detection sensor judges that the filter screen needs to be cleaned in time, and the foreign matter detection sensor will immediately issue an alarm to remind the user to clean the filter screen, avoiding that the filter screen is seriously blocked to affect the normal use of the air purifier.
[0035] In one of the embodiments, the first light beam adjusting piece 3 and the second light beam adjusting piece 4 are arranged in a central symmetry, at this time, the second shell 6, the light sensitive component 2 and the second light beam adjusting piece 4 are inverted, and the sensor can still be used normally.
[0036] In one of the embodiments, the first light beam adjusting piece 3 and the second light beam adjusting piece 4 are offset in the horizontal direction, but still have an overlapping area, at this time, the strip parallel light beam passing through the first optical surface 302 vertically passes through and enters the second light beam adjusting piece 4.
[0037] In one of the embodiments, as shown in Figure 1 and Figure 2 , the first shell 5 and the second shell 6 are further included, the first shell 5 includes a mounting plate 501, a first cover plate 502 and a second cover plate 503, the first cover plate 502 and the second cover plate 503 are respectively detachably installed at the lower part and the upper part of the mounting plate 501, the light source component 1 is located between the mounting plate 501 and the first cover plate 502, and the first light beam adjusting piece 3 is located between the mounting plate 501 and the second cover plate 503; the second shell 6 includes a fixed plate 601, a third cover plate 602 and a fourth cover plate 603, the third cover plate 602 and the fourth cover plate 603 are respectively detachably installed at the lower part and the upper part of the fixed plate 601, the light sensitive component 2 is located between the fixed plate 601 and the third cover plate 602, and the second light beam adjusting piece 4 is located between the fixed plate 601 and the fourth cover plate 603.
[0038] If it is necessary to repair and replace parts, the maintenance personnel can directly remove the first cover plate 502, the second cover plate 503, the third cover plate 602 and the fourth cover plate 603, or only remove a cover plate and replace and repair the internal parts, which is convenient to disassemble and assemble, and removing a cover plate will not affect the parts in other cover plates, reducing the difficulty of repair and disassembly.
[0039] As shown in Figure 1As shown, an air purifier comprises a primary filter screen and the foreign matter detection sensor, the light source assembly 1 and the first light beam adjusting member 3 are located at one end of the primary filter screen, the photosensitive assembly 2 and the second light beam adjusting member 4 are located at the other end of the primary filter screen, and the first light beam adjusting member 3 and the second light beam adjusting member 4 are located at the air inlet side of the primary filter screen for detecting the foreign matter blocked on the primary filter screen.
[0040] The above is only the preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A foreign object detection sensor, characterized by, The application relates to a light source assembly (1), a photosensitive assembly (2), a first light beam adjusting member (3) and a second light beam adjusting member (4), wherein the photosensitive assembly (2) is used for receiving light signals, the first light beam adjusting member (3) is used for adjusting the light emitted by the light source assembly (1) into a strip-shaped parallel light beam, the first light beam adjusting member (3) comprises a convex surface (301) used for collimating the light emitted by the light source assembly (1) to form a collimated light beam, the light emitted by the light source assembly (1) directly irradiates on the convex surface (301), and the second light beam adjusting member (4) is used for adjusting the strip-shaped parallel light beam into a light spot irradiating on the photosensitive assembly (2).
2. The foreign object detection sensor of claim 1, wherein, The light source assembly (1) is arranged opposite to the convex surface (301), and the light source assembly (1) is arranged at a focal point position of the convex surface (301).
3. The foreign object detection sensor of claim 1, wherein, The first light beam adjusting member (3) and the second light beam adjusting member (4) are both solid lenses, the first light beam adjusting member (3) further comprises a first optical surface (302) and a second optical surface (303), the first optical surface (302) is used for reflecting the collimated light beam, the collimated light beam passes through the second optical surface (303) to form the strip-shaped parallel light beam after being reflected by the first optical surface (302), and the first light beam adjusting member (3) is in a triangular structure as a whole, wherein the convex surface (301), the first optical surface (302) and the second optical surface (303) are respectively three sides of the triangle, the first optical surface (302) is provided with a stepped structure, the stepped structure comprises connecting surfaces and reflection inclined surfaces, the connecting surfaces are connected with adjacent reflection inclined surfaces, the reflection inclined surfaces are used for reflecting the collimated light beam, and the incident angle beta of the collimated light beam on the reflection inclined surfaces is greater than a critical angle.
4. The foreign object detection sensor of claim 3, wherein, An angle exists between the axis of the convex surface (301) and the first optical surface (302), and the angle theta is less than 45 degrees.
5. The foreign object detection sensor of claim 3, wherein, The direction of the collimated light beam is a first direction, the direction of the light reflected by the first optical surface (302) is a second direction, the projection of the first optical surface (302) on a plane perpendicular to the first direction can completely cover the collimated light, and the projection of the second optical surface (303) on a plane perpendicular to the second direction can completely cover the light beam reflected by the first optical surface (302).
6. The foreign object detection sensor of claim 3, wherein, The incident angle beta of the collimated light beam on the reflection inclined surface is equal to 45 degrees.
7. A foreign object detection sensor according to any one of claims 3-6, characterized in that, After the collimated light beam is reflected by the reflection inclined surface of the first optical surface (302), the irradiation direction of the collimated light beam is perpendicular to the second optical surface (303).
8. A foreign object detection sensor according to any one of claims 1-6, characterized in that, The first light beam adjusting member (3) and the second light beam adjusting member (4) are structurally identical, and are arranged in mirror symmetry or in central symmetry.
9. A foreign object detection sensor according to any one of claims 1-6, wherein, The first shell (5) comprises a mounting plate (501), a first cover plate (502) and a second cover plate (503), the first cover plate (502) and the second cover plate (503) are detachably mounted on the lower part and the upper part of the mounting plate (501) respectively, the light source assembly (1) is located between the mounting plate (501) and the first cover plate (502), the first light beam adjusting part (3) is located between the mounting plate (501) and the second cover plate (503), the second shell (6) comprises a fixed plate (601), a third cover plate (602) and a fourth cover plate (603), the third cover plate (602) and the fourth cover plate (603) are detachably mounted on the lower part and the upper part of the fixed plate (601) respectively, the light sensitive assembly (2) is located between the fixed plate (601) and the third cover plate (602), and the second light beam adjusting part (4) is located between the fixed plate (601) and the fourth cover plate (603).
10. An air cleaner comprising a primary filter and the foreign matter detection sensor according to any one of claims 1 to 9, characterized by The light source assembly (1) and the first light beam adjusting part (3) are located at one end of the primary filter screen, the light sensitive assembly (2) and the second light beam adjusting part (4) are located at the other end of the primary filter screen, and the first light beam adjusting part (3) and the second light beam adjusting part (4) are located on the air inlet side of the primary filter screen.