Dust sensor and control method thereof, and air purifier

Abstract

The present invention discloses a dust sensor and a control method thereof, and an air purifier, wherein the dust sensor is used to detect the dust concentration in the air duct, and comprises a lens barrel, a condenser lens, a light emitter and a light receiver, wherein the lens barrel and the light emitter are arranged on both sides of the air duct, the condenser lens is arranged at the end of the lens barrel, and the light receiver is arranged in the lens barrel, and further comprises a detection component and a detection light source, wherein the detection component is arranged between the condenser lens and the light receiver, and the detection light emitted by the detection light source is received by the detection component through the condenser lens, so as to determine the cleaning time of the condenser lens according to the electrical signal value output by the detection component. The present invention provides a dust sensor and a control method thereof, and an air purifier, wherein the transmittance of the condenser lens is obtained by the detection component, and the cleaning time of the condenser lens is determined according to the transmittance of the condenser lens, so as to ensure the optimal operating performance of the dust sensor and extend the service life of the dust sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of air purification, and in particular to a dust sensor and a control method thereof, and an air purifier. Background Art

[0002] Existing air purifiers widely use dust sensors to detect PM2.5 in the air. Depending on the use environment of the air purifier, the regular cleaning and maintenance of the dust sensor also varies depending on the environment. In general environments, cleaning is required every 1-2 months, and in harsh environments, frequent cleaning is required. If the dust sensor is not cleaned and maintained in time, the dust sensor's dust detection data will be inaccurate.

[0003] Since the dust sensor is inside the machine body and cannot be directly viewed, it is difficult for users to determine whether cleaning and maintenance are needed. Therefore, it is urgent to design a technical solution that can automatically detect the amount of dust attached to the dust sensor to determine the cleaning time of the dust sensor. Summary of the invention

[0004] To solve the technical problems in the background technology, the present invention provides a dust sensor and a control method thereof, and an air purifier, which can detect the amount of attachments on the surface of the focusing lens, thereby determining the cleaning time of the focusing lens, ensuring the optimal operating performance of the dust sensor, and extending the service life of the dust sensor.

[0005] To achieve the above-mentioned purpose, the specific technical solutions of a dust sensor and a control method thereof and an air purifier of the present invention are as follows:

[0006] First of all, the present application provides a dust sensor for detecting the dust concentration in the air duct, including a lens barrel, a focusing lens, a light emitter and a light receiver. The lens barrel and the light emitter are respectively arranged on both sides of the air duct, the focusing lens is arranged at the end of the lens barrel, and the light receiver is arranged in the lens barrel. It also includes a detection component and a detection light source. The detection component is arranged between the focusing lens and the light receiver. The detection light emitted by the detection light source passes through the focusing lens and is received by the detection component to determine the cleaning timing of the focusing lens according to the electrical signal value output by the detection component.

[0007] Furthermore, the detection component includes an infrared photosensor for capturing light emitted by the detection light source, and the infrared photosensor is connected to the controller to output a real-time electrical signal value to the controller.

[0008] Furthermore, the detection component includes a photoresistor and a voltage divider resistor connected in series, one end of the photoresistor is grounded, the connection point between the photoresistor and the voltage divider resistor is the output end, and the other end of the voltage divider resistor is the power input end.

[0009] Furthermore, the top of the detection component is below the light receiver.

[0010] Furthermore, an obtuse angle is formed between the axis of the lens barrel and the optical axis of the light emitter, and the axis of the lens barrel coincides with the optical axis of the detection light source.

[0011] Furthermore, the dust sensor also includes a cleaning component, which delivers washing water to the focusing lens to clean the attachments on the surface of the focusing lens.

[0012] Furthermore, the cleaning component includes an inlet pipe and a drain pipe, which are respectively connected to the air inlet at the bottom of the air duct, and are respectively provided with an inlet solenoid valve and a drain solenoid valve, and a heating component is provided in the inlet pipe.

[0013] Secondly, the present application provides a control method for the above-mentioned dust sensor, comprising the following steps:

[0014] After each use of the dust sensor, turn on the detection light source to obtain the real-time electrical signal value output by the detection component;

[0015] Determining whether the real-time electrical signal value satisfies the condensing lens cleaning condition;

[0016] If it is satisfied, it is determined that the focusing lens needs to be cleaned and a reminder signal is issued.

[0017] Furthermore, before the dust sensor is used for the first time, the detection light source is turned on to obtain the initial electrical signal value output by the detection component;

[0018] The determining whether the real-time electrical signal value satisfies the condenser lens cleaning condition includes:

[0019] Calculate the light transmittance of the focusing lens according to the real-time electrical signal value and the initial electrical signal value;

[0020] If the light transmittance of the focusing lens is less than or equal to a preset light transmittance threshold, the focusing lens cleaning condition is met.

[0021] Furthermore, the determining whether the real-time electrical signal value satisfies the condenser lens cleaning condition includes:

[0022] When the real-time electrical signal value is less than or equal to a preset electrical signal threshold, the focusing lens cleaning condition is met.

[0023] Further, the step of determining whether the focusing lens needs to be cleaned includes:

[0024] Control the water inlet solenoid valve and the heating component to open and inject washing water into the air duct until the water inlet time reaches the preset water inlet time, and then control the water inlet solenoid valve and the heating component to close;

[0025] When the washing water stays in the air duct for a preset time, the water outlet solenoid valve is controlled to open.

[0026] Again, the present application provides an air purifier, comprising an air duct and the above-mentioned dust sensor.

[0027] The present invention provides a dust sensor and a control method thereof, and an air purifier having the following advantages: the transmittance of a focusing lens is obtained by a detection component, and the amount of attachments on the surface of the focusing lens is determined according to the transmittance of the focusing lens, thereby determining the timing for cleaning the focusing lens, thereby ensuring the optimal operating performance of the dust sensor and extending the service life of the dust sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a dust sensor according to a first embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a dust sensor according to a second embodiment of the present invention;

[0030] Figure 3 The figure is a flow chart of the control method of the dust sensor of the present invention.

[0031] Explanation of the numbers in the figure: 1. Air duct; 11. Water inlet pipe; 12. Drainage pipe; 2. Lens barrel; 3. Focusing lens; 4. Light receiver; 5. Light transmitter; 6. Detection component; 7. Detection light source; 8. Heating component. DETAILED DESCRIPTION

[0032] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0033] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined.

[0034] Typically, a dust sensor is used to detect the dust concentration in the air duct 1, including a lens barrel 2, a focusing lens 3, a light emitter 5 and a light receiver 4. The lens barrel 2 and the light emitter 5 are respectively arranged on both sides of the air duct 1, the focusing lens 3 is arranged at the end of the lens barrel 2, and the light receiver 4 is arranged in the lens barrel 2. The axis of the lens barrel 2 intersects with the optical axis of the light emitter 5. When air containing dust is introduced into the air duct 1, when the dust-containing airflow passes through the intersection area of ​​the optical axes, the dust in the airflow will reflect the light emitted by the light emitter 5, and the light is received by the light receiver 4 after reflection, and the intensity of the reflected light is directly proportional to the dust concentration in the airflow, that is, the greater the intensity of the reflected light received by the light receiver 4, the greater the dust concentration in the airflow, thereby obtaining the dust concentration in the air duct 1.

[0035] Usually, there is an obtuse angle between the axis of the lens barrel 2 and the optical axis of the light emitter 5, such as an angle of 135°.

[0036] Specifically, the light transmitter 5 may be an infrared laser, a visible light laser, etc., and the light receiver 4 may be a phototransistor.

[0037] As dust continuously adheres to the surface of the condenser lens 3, the transmittance of the condenser lens 3 gradually decreases, which will affect the detection accuracy of the dust sensor. In order to determine the cleaning and maintenance time of the dust sensor, in this application, Figure 1 As shown, the dust sensor also includes a detection component 6 and a detection light source 7. The detection component 6 is arranged between the focusing lens 3 and the light receiver 4. The detection light emitted by the detection light source 7 passes through the focusing lens 3 and is received by the detection component 6 to determine the cleaning timing of the focusing lens 3 according to the electrical signal value output by the detection component 6.

[0038] Generally, as the number of times or the usage time of the dust sensor increases, the transmittance of the focusing lens 3 gradually decreases. When the electrical signal value output by the detection component 6 is less than or equal to the preset electrical signal threshold, it can be determined that there is excessive attachment on the surface of the focusing lens 3, and the focusing lens 3 needs to be cleaned, and an alarm message is issued to prompt the user to deal with it in time.

[0039] In this embodiment, the detection component 6 includes an infrared photosensor for capturing light emitted by the detection light source 7. The infrared photosensor is connected to the controller to output a real-time electrical signal value to the controller, thereby monitoring the cleanliness of the focusing lens 3 and determining whether the sensor needs cleaning and maintenance.

[0040] In another embodiment, the detection component 6 includes a photoresistor R2 and a voltage-dividing resistor R1 connected in series, one end of the photoresistor R2 is grounded, the connection point between the photoresistor R2 and the voltage-dividing resistor R1 is the output end, and the other end of the voltage-dividing resistor R1 is the power input end. Whether the dust sensor needs to be cleaned is monitored by testing the voltage division on the photoresistor R2. When there is light, the resistance of the photoresistor R2 is very small, which is equivalent to a short circuit. When the light is weakened, the resistance of the photoresistor R2 will increase sharply, thereby realizing the detection of light transmission of the focusing lens 3.

[0041] In this embodiment, the top of the detection component 6 is below the light receiver 4 to prevent the detection component 6 from blocking the detection of the phototransistor, thereby improving the detection quality.

[0042] Furthermore, the axis of the lens barrel 2 coincides with the optical axis of the detection light source 7 , that is, the light emitted by the detection light source 7 is vertically incident on the condenser lens, and after passing through the condenser lens, is captured by the detection component 6 .

[0043] When there are too many attachments on the surface of the focusing lens 3, the dust sensor needs to be maintained, and the dust sensor is set inside the body, which is not convenient for cleaning. Figure 2 As shown, the dust sensor further includes a cleaning component, which delivers washing water to the focusing lens 3 to clean attachments on the surface of the focusing lens 3.

[0044] Specifically, the cleaning component includes an inlet pipe 11 and a drain pipe 12, which are respectively connected to the air inlet at the bottom of the air duct 1, and a water inlet solenoid valve and a drain solenoid valve are respectively provided on the inlet pipe 11 and the drain pipe 12, and a heating component 8 is provided in the inlet pipe 11.

[0045] The dust sensor provided in this embodiment obtains the transmittance of the focusing lens 3 through the detection component 6, and determines the amount of attachments on the surface of the focusing lens 3 according to the transmittance of the focusing lens 3, thereby determining the cleaning timing of the focusing lens 3, thereby ensuring the optimal operating performance of the dust sensor and extending the service life of the dust sensor.

[0046] The present application also provides a control method for the above dust sensor, comprising the following steps:

[0047] S10, after each use of the dust sensor, turn on the detection light source 7 to obtain the real-time electrical signal value output by the detection component 6;

[0048] S20, judging whether the real-time electrical signal value satisfies the cleaning condition of the focusing lens 3;

[0049] S30: If the conditions are met, it is determined that the focusing lens 3 needs to be cleaned and a reminder signal is issued.

[0050] Specifically, by detecting the use status of the light transmitter 5 and / or the light receiver 4, it is determined whether the dust sensor has been used up. For example, when the light transmitter 5 changes from the use state to the stop state and the light receiver 4 changes from the power-on state to the power-off state, it is determined that the dust sensor has been used up.

[0051] In one embodiment, before turning on the detection light source 7 and obtaining the real-time electrical signal value output by the detection component 6 after the dust sensor is used each time, the method further includes:

[0052] Before the dust sensor is used for the first time, the detection light source 7 is turned on to obtain the initial electrical signal value output by the detection component 6;

[0053] The step of judging whether the real-time electrical signal value satisfies the cleaning condition of the focusing lens 3 includes:

[0054] Calculate the light transmittance of the condenser lens 3 according to the real-time electrical signal value and the initial electrical signal value;

[0055] When the light transmittance of the condenser lens 3 is less than or equal to a preset light transmittance threshold, it is determined that there are excessive attachments on the surface of the condenser lens 3 and the condenser lens 3 needs to be cleaned.

[0056] The control method of the dust sensor provided in the present embodiment obtains the initial signal value of the dust sensor before the first use or before the first use after cleaning, so as to calibrate the detection component 6 and improve the detection accuracy.

[0057] In another embodiment, the determining whether the real-time electrical signal value satisfies the cleaning condition of the focusing lens 3 includes:

[0058] When the real-time electrical signal value is less than or equal to the preset electrical signal threshold, the cleaning condition of the focusing lens 3 is met.

[0059] Further, the step of determining whether the focusing lens 3 needs to be cleaned includes:

[0060] Control the water inlet solenoid valve and the heating component 8 to open and inject washing water into the air duct 1 until the water inlet time reaches the preset water inlet time, and then control the water inlet solenoid valve and the heating component 8 to close;

[0061] When the washing water stays in the air duct 1 for a preset time, the water outlet solenoid valve is controlled to open.

[0062] The present application also provides an air purifier, comprising an air duct 1 and the above-mentioned dust sensor.

[0063] The present invention provides a dust sensor and a control method thereof, and an air purifier. The infrared photosensitive sensor behind the condensing lens 3 (or through a photoresistor in conjunction with an external voltage detection circuit) receives infrared rays emitted by the infrared light-emitting tube in front of the lens. During the operation of the air purifier, the dust sensor is also working continuously, and some dust will adhere to the condensing lens 3. When the dust accumulates to a certain extent in the sensor, the light transmittance of the condensing lens 3 will decrease, and the light signal received by the infrared photosensitive sensor or the photoresistor will be weakened (if an infrared photosensitive sensor is used, the received light intensity will be directly sent to the controller after processing, and if an infrared photosensitive sensor is used, the received light intensity will be directly sent to the controller after processing. If it is a photoresistor, it will detect the light intensity through an external detection circuit. When the light signal weakens, the voltage across R2 increases sharply, and the chip I / O port reads the voltage change). The voltage change is read by the chip, and the threshold is set using the program. When the voltage read by the chip I / O port reaches the threshold, the indicator light on the whole machine will light up to remind the user that the performance of the dust sensor has declined and the PM2.5 data is inaccurate and needs to be cleaned up. At the same time, the WiFi on the air purifier will send a reminder message to the user's mobile phone app, and upload a cleaning tutorial to assist the user in cleaning. This linkage between the whole machine prompt and the tutorial on the app greatly improves the user experience.

[0064] Each time the air purifier ends its operation, the detection light source 7 continues to work for a period of time, and at the same time the infrared photosensor or photoresistor R2 starts working and sends a voltage signal to the controller to determine the current state of the dust sensor. This process is used for judgment each time the whole machine ends its operation.

[0065] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A dust sensor for detecting dust concentration in an air duct, characterized in that: The invention comprises a lens barrel, a focusing lens, a light emitter and a light receiver, wherein the lens barrel and the light emitter are arranged on both sides of the air duct, the focusing lens is arranged at the end of the lens barrel, and the light receiver is arranged in the lens barrel. The invention also comprises a detection component and a detection light source, wherein the detection component is arranged between the focusing lens and the light receiver, and the detection light emitted by the detection light source is received by the detection component through the focusing lens, so as to determine the cleaning time of the focusing lens according to the value of the electrical signal output by the detection component; an obtuse angle is formed between the axis of the lens barrel and the optical axis of the light emitter, and the axis of the lens barrel coincides with the optical axis of the detection light source; the dust sensor also comprises a cleaning component, which transports washing water to the focusing lens to clean the attachments on the surface of the focusing lens; the cleaning component comprises a water inlet pipe and a drainage pipe, the water inlet pipe and the drainage pipe are respectively connected to the air inlet at the bottom of the air duct, a water inlet solenoid valve and a drainage solenoid valve are respectively arranged on the water inlet pipe and the drainage pipe, and a heating component is arranged in the water inlet pipe.

2. The dust sensor according to claim 1, characterized in that: The detection component includes an infrared photosensor for capturing light emitted by a detection light source. The infrared photosensor is connected to a controller to output a real-time electrical signal value to the controller.

3. The dust sensor according to claim 1, characterized in that: The detection component comprises a photoresistor and a voltage-dividing resistor connected in series, one end of the photoresistor is grounded, the connection point between the photoresistor and the voltage-dividing resistor is the output end, and the other end of the voltage-dividing resistor is the power input end.

4. The dust sensor according to any one of claims 1 to 3, characterized in that: The top of the detection component is below the light receiver.

5. A method for controlling a dust sensor according to any one of claims 1 to 4, characterized in that: The following steps are involved: After each use of the dust sensor, turn on the detection light source to obtain the real-time electrical signal value output by the detection component; Determining whether the real-time electrical signal value satisfies the condensing lens cleaning condition; If the conditions are met, it is determined that the focusing lens needs to be cleaned and a reminder signal is issued; Before turning on the detection light source and obtaining the real-time electrical signal value output by the detection component after the dust sensor is used each time the dust sensor is used, the method further includes: Before using the dust sensor for the first time, turn on the detection light source to obtain the initial electrical signal value output by the detection component; The determining whether the real-time electrical signal value satisfies the condenser lens cleaning condition includes: Calculate the light transmittance of the focusing lens according to the real-time electrical signal value and the initial electrical signal value; If the light transmittance of the condenser lens is less than or equal to the preset light transmittance threshold, the condenser lens cleaning condition is met; Or judging whether the real-time electrical signal value satisfies the condenser lens cleaning condition, including: When the real-time electrical signal value is less than or equal to a preset electrical signal threshold, the focusing lens cleaning condition is met.

6. The method according to claim 5, characterized in that The step of determining that the condenser lens needs to be cleaned includes: Control the water inlet solenoid valve and the heating component to open and inject washing water into the air duct until the water inlet time reaches the preset water inlet time, and then control the water inlet solenoid valve and the heating component to close; When the washing water stays in the air duct for a preset time, the water outlet solenoid valve is controlled to open.

7. An air purifier, characterized in that: It comprises an air duct and a dust sensor as claimed in any one of claims 1 to 4.

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