A liquid level sensor and apparatus having a liquid container

Abstract

The application provides a liquid level sensor and a device with a liquid container, and relates to the technical field of liquid level measurement. The liquid level sensor comprises a main body structure and a detection structure. The main body structure comprises a closed cavity along a first direction and a plurality of reflection sides. The detection structure is located in the closed cavity and comprises a circuit board, a light emitting element and a light receiving element located on opposite sides of the circuit board. The detection light beams can be reflected to the light receiving element in sequence through the reflection sides, and the transmission direction of the detection light beams transmitted to the light receiving element is parallel to the light incidence direction of the light receiving element or the included angle is small. The liquid level sensor can realize optical isolation of the light emitting element and the light receiving element based on the light-proof circuit board, and realize transmission of the light beams between the light emitting element and the light receiving element based on the plurality of reflection sides of the main body structure, so that the structure is simplified and the precision is high.

Description

Technical Field

[0001] This application relates to the field of liquid level measurement technology, and more particularly to a liquid level sensor and a device having a liquid container. Background Technology

[0002] With the rapid development of intelligent electronic products and the increasing demand for intelligent equipment in various aspects of production and daily life, more and more devices are required to be intelligent. For example, various devices with water containers, such as kettles and dishwashers, have an increasing demand for water level detection, and the requirements are becoming more stringent. Currently, most water level sensors on the market only detect single water levels. How to achieve flexible and simple multi-segment water level detection has become a long-standing and challenging problem in the field of water level detection.

[0003] Currently, most mainstream multi-segment water level detection is based on photoelectric water level detection sensors, but there are a series of problems such as complex processing and assembly and high cost, which affect its practical application. Utility Model Content

[0004] In view of this, this application provides a liquid level sensor and a device with a liquid container, as follows:

[0005] A liquid level sensor, comprising:

[0006] The main structure includes a closed cavity extending along a first direction and a plurality of reflective side surfaces surrounding the closed cavity; wherein the first direction is parallel to the axial direction of the main structure.

[0007] A detection structure is located in the enclosed cavity and includes an opaque circuit board and an optical transceiver unit. The optical transceiver unit includes a light emitting element and a light receiving element located on opposite sides of the circuit board along a second direction. The circuit board extends along a first direction, which is parallel to the plane of the circuit board, and the second direction is perpendicular to the plane of the circuit board.

[0008] The light emitting element emits a detection beam, and the light emission direction of the light emitting element is parallel to the second direction; the light receiving element generates a detection signal based on the detection beam transmitted to it through the plurality of the reflective sides, so as to detect the liquid level of the liquid to be tested based on the detection signal;

[0009] The reflective side corresponding to the light emission direction of the light emitting element has a first preset angle with the light emission direction of the light emitting element, so that if the height of the liquid level of the liquid to be tested is less than the height of the position where the detection beam is transmitted to the reflective side along the first direction, the reflective side corresponding to the light emission direction of the light emitting element will totally reflect the detection beam transmitted thereon.

[0010] The reflective side corresponding to the incident light direction of the light receiving element has a second preset angle with the incident light direction of the light receiving element, so that the transmission direction of the detection beam reflected to the light receiving element by the reflective side corresponding to the incident light direction of the light receiving element is parallel to the incident light direction of the light receiving element, or the angle is less than a first preset value; the incident light direction of the light receiving element is parallel to the second direction.

[0011] Optionally, along the light emission direction of the light emitting element, the plane containing the area of ​​the sidewall of the enclosed cavity corresponding to the light emitting element is perpendicular to the light emission direction of the light emitting element.

[0012] Optionally, along the incident light direction of the light receiving element, the plane containing the area of ​​the sidewall of the enclosed cavity corresponding to the light receiving element is perpendicular to the incident light direction of the light receiving element.

[0013] Optionally, along the direction surrounding the enclosed cavity, there is a third preset angle between adjacent reflective sides, such that if, along the first direction, the height of the liquid level to be tested is less than the height of the position where the detection beam is transmitted to the reflective side, the detection beam is sequentially totally reflected by the reflective side to the light receiving element; and if, along the first direction, the height of the liquid level to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, the reflective side refracts the detection beam transmitted thereon to the liquid to be tested.

[0014] Optionally, the main structure includes at least four reflective side surfaces along its axial direction, with the first preset angle being 45°, the second preset angle being 45°, and the third preset angle being 90°. Along the first direction, if the height of the liquid level to be measured is less than the height of the position where the detection beam is transmitted to the reflective side surface, the detection beam is sequentially totally reflected by the multiple reflective side surfaces to the light receiving element, and the transmission direction of the detection beam transmitted to the light receiving element is parallel to the incident light direction of the light receiving element.

[0015] Optionally, the detection structure includes a plurality of optical transceiver units arranged on the circuit board along the first direction;

[0016] Along the first direction, the height of the liquid level of the liquid to be tested is less than the height of the position where the detection beam is transmitted to the reflective side. The light receiving element generates a first detection signal based on the detection beam transmitted thereto. The first detection signal is not less than a second preset value.

[0017] Along the first direction, the height of the liquid level of the liquid to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, and the light receiving element generates a second detection signal based on the detection beam transmitted thereto, the second detection signal being no greater than a third preset value;

[0018] The second preset value is greater than the third preset value.

[0019] Optionally, along the first direction, the plurality of optical transceiver units include at least one optical transceiver unit located at both ends of the circuit board, and at least one optical transceiver unit located in the middle region of the circuit board;

[0020] The closer to the end of the circuit board, the smaller the distance between adjacent optical transceiver units along the first direction.

[0021] Optionally, the main structure is a transparent prism extending along the first direction.

[0022] Optionally, the light emitting element is an infrared emitting tube, and the light receiving element is an infrared receiving tube.

[0023] A device having a liquid container, including the liquid container and a liquid level sensor;

[0024] The liquid level sensor is located in the liquid container, and the liquid level sensor is any of the liquid level sensors described above.

[0025] Compared with related technologies, the beneficial effects of the technical solution of this application are as follows:

[0026] The liquid level sensor includes a main structure and a detection structure. The main structure includes a closed cavity extending along a first direction and penetrating the main structure, and multiple reflective sides surrounding the closed cavity. The detection structure is located within the closed cavity and includes an opaque circuit board and an optical transceiver unit. The optical transceiver unit includes a light emitting element and a light receiving element located on opposite sides of the circuit board along a second direction. The light emitting element emits a detection beam, and the light emission direction of the light emitting element is parallel to the second direction. The light receiving element generates a detection signal based on the detection beam transmitted to it through the multiple reflective sides, thereby detecting the liquid level of the liquid to be measured. The plane of the reflective side corresponding to the light emission direction of the light emitting element has a first preset angle with the light emission direction of the light emitting element. If the liquid to be measured does not submerge the position where the detection beam is transmitted to the reflective side, the reflective side corresponding to the light emission direction of the light emitting element can totally reflect the detection beam transmitted to it. If the height of the liquid level of the liquid to be measured is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, the reflective side corresponding to the light emission direction of the light emitting element refracts the detection beam transmitted to it into the liquid to be measured. The plane containing the reflective side corresponding to the incident light direction of the light-receiving element has a second preset angle with the incident light direction of the light-receiving element. This ensures that the transmission direction of the detection beam transmitted to the light-receiving element via the reflective side corresponding to the incident light direction is parallel to the incident light direction of the light-receiving element, or the angle is less than a first preset value. Therefore, this liquid level sensor can achieve optical isolation between the light-emitting and light-receiving elements based on an opaque circuit board, and achieve beam transmission between the light-emitting and light-receiving elements based on multiple reflective sides of the main structure. This simplifies the structure of the liquid level sensor and reduces costs, facilitating the practical application of photoelectric liquid level sensors. Simultaneously, the reflective side corresponding to the emitting light direction of the light-emitting element can totally reflect the detection beam transmitted to it along the emitting light direction of the light-emitting element. Furthermore, the detection beams transmitted sequentially to the light-receiving element via the reflective side coincide with or have a small angle with the incident light direction of the light-receiving element, thereby enabling more detection beams to be transmitted to the light-receiving element and ensuring detection accuracy. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0029] Figure 1 This application provides a schematic diagram of the structure of a liquid level sensor;

[0030] Figure 2 A schematic diagram of the main structure of a liquid level sensor provided in this application;

[0031] Figure 3 A schematic diagram of another liquid level sensor provided in this application;

[0032] Figure 4 This is a schematic diagram of another liquid level sensor provided in this application. Detailed Implementation

[0033] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0034] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] As described in the background section, current photoelectric water level detection sensors suffer from problems such as complex processing and assembly, and high cost. Specifically, the mainstream photoelectric water level detection sensors currently utilize infrared photoelectric devices to perform secondary total internal reflection on a prism for detection. This method requires optical isolation between the transmitting and receiving tubes. However, due to the small size of the optical isolation component, its processing and assembly are quite complex, resulting in high costs.

[0036] Based on the above, this application provides a liquid level sensor, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a liquid level sensor provided in this application, specifically a top view of the liquid level sensor, which includes a main structure 100 and a detection structure 200. (See attached diagram.) Figure 2 As shown, Figure 2This is a schematic diagram of the main structure 100. The main structure 100 includes a closed cavity 102 extending along a first direction, and also includes multiple reflective side surfaces 104 surrounding the closed cavity 102. Specifically, the multiple reflective side surfaces 104 are arranged along the axis surrounding the main structure 100 and are located around the closed cavity 102. It should be noted that the axis of the main structure 100 is parallel to the first direction, that is, the main structure 100 includes multiple reflective side surfaces along its extension direction. It should also be noted that, along the first direction, the extension length of the closed cavity 102 is less than the extension length of the main structure 100. The specific preparation process can be as follows: a groove extending inward along the first direction is formed on one side of the main structure 100 along the first direction. The groove does not penetrate the main structure 100. After forming the groove, the detection structure 200 is placed in the groove, and finally the opening of the groove is sealed by means of glue injection to form the closed cavity 102.

[0037] The detection structure 200 is located within the enclosed cavity 102, meaning it is sealed within this cavity. The detection structure 200 includes an opaque circuit board 202 and an optical transceiver unit. The optical transceiver unit includes a light-emitting element 204 and a light-receiving element 206 located on opposite sides of the circuit board 202 along a second direction. It should be noted that the circuit board 202 extends along a first direction, parallel to the plane of the circuit board 202, and the second direction is perpendicular to the plane of the circuit board 202. It is important to note that, to prevent damage to the optical transceiver unit caused by the light-emitting element 204 and / or the light-receiving element 206 colliding with the side of the enclosed cavity during placement of the detection structure 200 in the enclosed cavity 102 and during subsequent use, a gap may exist between the light-emitting element 204 and the side wall of the enclosed cavity 102, and a gap may also exist between the light-receiving element 206 and the side wall of the enclosed cavity 102.

[0038] The light emitting element 204 is used to emit a detection beam, and the light emission direction of the light emitting element 204 is parallel to the second direction. The light receiving element 206 generates a detection signal based on the detection beam transmitted to it through multiple reflective sides 104, so as to detect the liquid level of the liquid to be tested based on the detection signal. That is, the detection signal is used to detect the liquid level of the liquid to be tested, and the liquid level detection can be realized based on the intensity of the detection signal.

[0039] Among the multiple reflective surfaces 104 of the main structure 100, the plane of the reflective surface 104 corresponding to the light emission direction of the light emitting element 204 has a first preset angle A1 with respect to the light emission direction of the light emitting element 204. The purpose is that, along the first direction, if the height of the liquid level to be tested is less than the height of the position where the detection beam is transmitted to the reflective surface 104 (i.e., the liquid to be tested does not submerge the position where the detection beam is transmitted to the reflective surface 104), the reflective surface 104 corresponding to the light emission direction of the light emitting element 204 can totally reflect the detection beam transmitted to it along the light emission direction of the light emitting element 204. Simultaneously, when the height of the liquid level to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective surface 104, the reflective surface 104 corresponding to the light emission direction of the light emitting element 204 refracts the detection beam transmitted to it into the liquid to be tested. The height of the liquid level and the height of the position where the detection beam is transmitted to the reflective surface 104 can both be the height of the liquid level and the position where the detection beam is transmitted to the reflective surface 104 relative to the bottom of the liquid container along the first direction.

[0040] It should be noted that the light emission direction of the light emitting element 204 is the transmission direction of the beam center of the detection beam emitted by the light emitting element 204. Since most of the energy of the beam emitted by the light emitting element 204 is concentrated at the beam center, the light emission direction of the light emitting element 204 can be the transmission direction of the beam center of the detection beam emitted by the light emitting element 204. It should also be noted that, based on the principle of total internal reflection, the aforementioned first preset angle can be determined according to the density of the main structure 100 and the liquid to be tested. Total internal reflection occurs when the position of the detection beam reaching the reflective side 104 is not submerged by the detection liquid, and does not occur when the position of the detection beam reaching the reflective side 104 is submerged by the detection liquid. Therefore, based on this first preset angle, the incident angle of the detection beam reaching the reflective side 104 is greater than or equal to the critical angle for total internal reflection at the interface between the reflective side and the air, and less than the critical angle for total internal reflection at the interface between the reflective side and the liquid to be tested.

[0041] The plane containing the reflective side 104 corresponding to the incident light direction of the light receiving element 206 has a second preset angle with the incident light direction of the light receiving element 206. This ensures that the transmission direction of the detection beam transmitted to the light receiving element 206 via the reflective side 104 is parallel to the incident light direction of the light receiving element 206, or the angle is less than a first preset value. In other words, the detection beam, after total internal reflection via the reflective side 104 corresponding to the emitting light direction of the light emitting element 204, is ultimately reflected by the reflective side 104 corresponding to the incident light direction of the light receiving element 206 and transmitted to the light receiving element 206. The transmission direction of this beam is parallel to the incident light direction of the light receiving element 206, or the angle is less than the first preset value. It should be noted that, similar to the light emitting element 204, the light receiving element 206 is optimal for receiving beams transmitted perpendicularly to it; therefore, the incident light direction of the light receiving element 206 can be the direction perpendicular to the beam transmitted to it.

[0042] As described above, the detection structure 200 of the liquid level sensor is located in the closed cavity 102 of the main structure 100, and the light emitting element 204 and the light receiving element 206 of the detection structure 200 are located on opposite sides of its opaque circuit board 202. If the liquid to be measured does not submerge the position where the detection beam is transmitted to the reflecting side 104, the detection beam emitted by the light emitting element 204 is totally reflected by the corresponding reflecting side 104 after being transmitted to it, and is then reflected sequentially by the other reflecting sides 104 to the light receiving element 206. However, if the liquid to be measured submerges the position where the detection beam is transmitted to the reflecting side 104, the detection beam will be refracted into the liquid to be measured. Therefore, whether the liquid to be measured submerges the position where the detection beam is transmitted to the reflecting side 104 has a significant impact on the intensity of the detection beam transmitted to the light receiving element 206. Generally, the intensity of the detection signal generated by the light receiving element 206 based on the detection beam is related to the intensity of the detection beam it receives. Therefore, the liquid level of the liquid to be measured can be detected based on the detection signal generated by the light receiving element 206. In other words, the light emitting element 204 and the light receiving element 206 in the liquid level sensor are located on opposite sides of its opaque circuit board 202. Furthermore, based on the multiple reflective sides 104 of the main structure 100, the detection beam can be transmitted between the light emitting element 204 and the light receiving element 206, and the intensity of the detection signal generated by the light receiving element 206 is related to whether the liquid to be measured submerges the position of the detection beam transmitted to the reflective side 104, thereby realizing liquid level detection.

[0043] Therefore, this liquid level sensor can achieve optical isolation between the light emitting element 204 and the light receiving element 206 by placing them on opposite sides of an opaque circuit board 202. This eliminates the need for additional optical isolation components between the emitting and receiving tubes, as required in existing technologies. This simplifies the structure of the liquid level sensor, reduces costs, and facilitates the practical application of photoelectric liquid level sensors.

[0044] Furthermore, as described above, if the liquid to be tested does not submerge the detection beam transmitted to the reflective side 104, the reflective side 104, corresponding to the light emission direction of the light emitting element 204, can totally reflect the detection beam transmitted to it along the light emission direction of the light emitting element 204. The detection beam transmitted to the light receiving element 206 via the reflective side coincides with or has a small angle with the incident light direction of the light receiving element 206, thus enabling more detection beams to be transmitted to the light receiving element 206. Therefore, whether the liquid to be tested submerges the detection beam transmitted to the reflective side 104 has a significant impact on the intensity of the detection beam received by the light receiving element 206. That is, if the liquid to be tested does not submerge the detection beam transmitted to the reflective side 104, the intensity of the detection beam received by the light receiving element 206 will differ significantly, resulting in higher accuracy for the liquid level sensor. In other words, this liquid level detector can simplify the structure of the liquid level sensor and reduce costs while ensuring detection accuracy.

[0045] It should be noted that the light emitting element 204 and the light receiving element 206 are located at the same height, and under normal circumstances, the surface of the liquid to be measured is parallel to the second direction. Therefore, the position where the detection beam is transmitted to the reflecting side 104 is usually equal to the height of the optical transceiver unit. The liquid level height can be obtained based on the height of the optical transceiver unit, thus realizing liquid level detection. Furthermore, even if the surface of the liquid to be measured has an angle with the second direction, the liquid level height can still be obtained based on the angle between the liquid surface and the second direction, as well as the height of the optical transceiver unit, thereby realizing liquid level detection. It should also be noted that during liquid level detection, the liquid level can be determined based on the analog signal output by the light receiving element 206, or the analog signal output by the light receiving element 206 can be converted into a digital signal using a microcontroller or similar device for liquid level determination.

[0046] In one embodiment of this application, such as Figure 1As shown, along the light emission direction of the light emitting element 204, the plane containing the area on the sidewall of the enclosed cavity 102 corresponding to the light emitting element 204 is perpendicular to the light emission direction of the light emitting element 204. This allows for less reflection of the detection beam emitted by the light emitting element 204 when it reaches the sidewall of the enclosed cavity 102. More of the detection beam emitted by the light emitting element 204 can reach the reflecting side 104, which in turn helps more of the detection beam reach the light receiving element 206, ensuring the intensity of the detection beam received by the light receiving element 206 and thus guaranteeing detection accuracy.

[0047] In one embodiment of this application, such as Figure 1 As shown, along the incident light direction of the light receiving element 206, the plane containing the area on the sidewall of the enclosed cavity 102 corresponding to the light receiving element 206 is perpendicular to the incident light direction of the light receiving element 206. Similarly, this allows the detection beam to be reflected less by the sidewall of the enclosed cavity 102 when it reaches the sidewall corresponding to the light receiving element 206, resulting in more detection beams reaching the light receiving element 206, thus ensuring the intensity of the detection beam received by the light receiving element 206 and consequently guaranteeing detection accuracy.

[0048] In one embodiment of this application, such as Figure 1 As shown, adjacent reflective surfaces 104 have a third preset included angle A3. If, along the first direction, the height of the liquid level to be measured is less than the height at which the detection beam reaches the reflective surface 104, the detection beam is sequentially totally reflected by the reflective surface 104 to the light receiving element 206. Conversely, if, along the first direction, the height of the liquid level to be measured is greater than or equal to the height at which the detection beam reaches the reflective surface 104, the reflective surface 104 refracts the detection beam transmitted to it to the liquid level to be measured. Therefore, if, along the first direction, the height of the liquid level to be measured is less than the height at which the detection beam reaches the reflective surface 104, the detection beam can be sequentially totally reflected by the reflective surface 104 to the light receiving element 206, thus allowing more detection beams to be transmitted to the light receiving element 206, ensuring the intensity of the detection beam received by the light receiving element 206, and thereby ensuring detection accuracy. It should be noted that, along the first direction, the height of the liquid level of the liquid to be tested is less than the height of the position where the detection beam is transmitted to the reflective side 104. The detection beam is sequentially reflected by the reflective side 104 to the light receiving element 206. It is required that the position where the detection beam is transmitted to each reflective side 104 is submerged by the liquid to be tested.

[0049] Based on the above embodiments, in one embodiment of this application, the main structure 100 includes at least four reflective side surfaces 104 along its axial direction, with a first preset angle of 45°, a second preset angle of 45°, and a third preset angle of 90°, so that the position where the detection beam is transmitted to the reflective side surface 104 is not submerged by the liquid to be tested. The reflective side surface 104 corresponding to the light emission direction of the light emitting element 204 can totally reflect the detection beam transmitted thereto, and after the detection beam is totally reflected by the reflective side surface 104, it will also be totally reflected by the other reflective side surfaces 104 to the light receiving element 206. At the same time, the transmission direction of the detection beam transmitted to the light receiving element 206 is parallel to the incident light direction of the light receiving element 206, so that more detection beams are transmitted to the light receiving element 206, ensuring the intensity of the detection beam received by the light receiving element 206, thereby ensuring detection accuracy.

[0050] If the detection beam is not submerged by the liquid to be measured at the position where it is transmitted to the reflective side 104, the detection beam can undergo at least four total internal reflections within the main structure 100 to be transmitted to the light receiving element 206. This allows for a large-angle twist in the transmission direction of the detection beam based on multiple total internal reflections, enabling the detection beam to be transmitted between the light emitting element 204 and the light receiving element 206 located on opposite sides of the circuit board 202. This ensures that the detection beam emitted by the light emitting element 204 can be transmitted to the light receiving element 206, thereby achieving liquid level detection.

[0051] It should be noted that the first preset angle is 45°, the second preset angle is 45°, and the third preset angle is 90°. This ensures that the detection beam undergoes total internal reflection at each reflecting side 104, while the incident angle and reflection angle of the detection beam at each reflecting side 104 are both 45°. Therefore, the detection beam can be transmitted through total internal reflection within the main structure 100, and the transmission directions of the incident and reflected beams at each reflecting side 104 are perpendicular to each other. This makes the light emission direction of the light emitting element 204 parallel and opposite to the light incident direction of the light receiving element 206. Consequently, the transmission direction of the detection beam transmitted through the sidewall of the enclosed cavity 102 to the light receiving element 206 can be parallel to its incident direction, or the angle is very small. This allows the detection beam to be received by the light receiving element 206 more, ensuring detection accuracy.

[0052] Optionally, for the liquid level sensor described in this application, as follows: Figure 1 As shown, its main structure 100 can be a prism structure with a rectangular cross-section, that is, the main structure 100 can be a rectangular prism, which includes four sides, all of which are reflective sides 104, and the second preset angle between adjacent reflective sides 104 is 90°. This application does not limit this; in other embodiments of this application, the main structure 100 can also be other shapes, for example... Figure 3As shown, the main structure 100 can also be a polyhedron, comprising eight sides, four of which are reflective sides 104. Specifically, the reflective sides 104 are spaced apart, but the included angle between adjacent reflective sides 104 is 90°. It should be noted that the above... Figure 2 and Figure 3 The main structure 100 includes four reflective side surfaces 104 as an example. However, this application does not limit the number of reflective side surfaces 104 of the main structure 100. The specific number depends on the situation.

[0053] In one embodiment of this application, such as Figure 4 As shown, Figure 4 This is a schematic diagram of a liquid level sensor provided in this application. The detection structure 200 includes multiple optical transceiver units arranged along a first direction on a circuit board 202. Specifically, the detection structure 200 includes a pair of light emitting elements 204 and light receiving elements 206 arranged along the first direction on the circuit board 202 to achieve multi-liquid level detection. The liquid level sensor is placed in the liquid to be detected along the first direction, meaning that the liquid level sensor has multiple optical transceiver units arranged vertically relative to the liquid to be detected, thereby enabling multi-liquid level detection.

[0054] Specifically, when the liquid level sensor performs liquid level detection, if the height of the liquid level to be measured is less than the height of the detection beam transmitted to the reflective side 104 (i.e., the liquid level of the liquid to be measured does not exceed the height of the detection beam transmitted to the reflective side 104), the optical receiving element 206 generates a first detection signal based on the detection beam transmitted thereto, and the first detection signal is not less than a second preset value. If the height of the liquid level to be measured is greater than or equal to the height of the detection beam transmitted to the reflective side 104 (i.e., the liquid level of the liquid to be measured does not exceed the height of the detection beam transmitted to the reflective side 104), the optical receiving element 206 generates a second detection signal based on the detection beam transmitted thereto, and the second detection signal is not greater than a third preset value. The second preset value is greater than the third preset value; for example, the second preset value can be 4.7V and the third preset value can be 0.3V, so that liquid level detection can be achieved based on the intensity of the detection signal. Specifically, when the detection signal generated by the optical receiving element 206 in the optical transceiver unit is less than or equal to 0.3V, it indicates that the liquid level has exceeded the position where the detection beam is transmitted to the reflective side 104. Conversely, when the detection signal generated by the optical receiving element 206 in the optical transceiver unit is greater than or equal to 4.7V, it indicates that the liquid level has not exceeded the position where the detection beam is transmitted to the reflective side 104. Therefore, based on the detection signals generated by the optical receiving element 206 in each optical transceiver unit, the position of the liquid level can be determined, thereby achieving liquid level detection.

[0055] It should be noted that the reason why the optical receiving element 206 generates detection signals of different intensities depending on whether the liquid level of the liquid under test exceeds or does not exceed the position where the detection beam is transmitted to the reflecting side has been explained in detail above and will not be repeated here. It should also be noted that the above-mentioned multiple optical transceiver units can operate simultaneously or sequentially according to a set order.

[0056] In one embodiment of this application, such as Figure 4 As shown, along the first direction, the plurality of optical transceiver units include at least one optical transceiver unit located at both ends of the circuit board 202, and at least one optical transceiver unit located in the middle region of the circuit board. Subsequently, along the depth direction of the liquid to be detected, the liquid level sensor includes at least optical transceiver units for bottom liquid level detection, middle liquid level detection, and top liquid level detection, so as to realize bottom, middle, and top liquid level detection, that is, to realize multi-liquid level detection.

[0057] In particular, in this embodiment, as Figure 4 As shown, among the multiple optical transceiver units arranged along the first direction, the closer to the end of the circuit board 202, the smaller the distance between adjacent optical transceiver units along the first direction. In other words, the closer to the bottom and top of the multiple optical transceiver units, the smaller the distance between adjacent units. This allows for more frequent liquid level detection in areas closer to the bottom and top, minimizing the possibility of excessive liquid level and overflow, thus improving the reliability of the liquid level sensor.

[0058] It should be noted that this application does not limit the number of optical transceiver units on the circuit board 202, but depends on the specific circumstances. That is, the number and location of the liquid level detection points of this liquid level sensor can be determined simply by designing the number and location of the optical transceiver units on the circuit board 202. It is ready to use immediately, simple and convenient, and its small integrated design facilitates installation and use. The circuit is simple and low-cost, and there are no moving mechanical parts, so there will be no mechanical failure. It has the advantages of long life, high mechanical strength, and good reliability.

[0059] In one embodiment of this application, the main structure 100 has a transparent prism extending along a first direction, for example... Figure 1The image shows a transparent prism with a rectangular cross-section, or a rectangular prism made of infrared-transmitting material, such as acrylic, PC plastic, PE plastic, PP plastic, or glass. The light emitting element 204 includes an infrared emitting tube, and the light receiving element 206 includes an infrared receiving tube, ensuring that the detection beam is an infrared beam. This prevents the detection beam from being affected by external light, electromagnetic interference, or other disturbances during transmission within the main structure 100, thus reducing the environmental requirements of the liquid level sensor. It should be noted that the light emitting element 204 is an infrared emitting tube, and the light receiving element 206 is an infrared receiving tube. Specifically, the light emitting element 204 includes an infrared emitting tube and a driving circuit, and the light receiving element 206 includes an infrared receiving tube and a driving circuit.

[0060] Based on the liquid level sensor described in any of the above embodiments, this application also provides an apparatus having a liquid container, the apparatus comprising the liquid container and a liquid level sensor. Specifically, the liquid level sensor is located in the liquid container, and the liquid level sensor is the liquid level sensor described in any of the above embodiments.

[0061] In summary, this application provides a liquid level sensor and a device with a liquid container. The liquid level sensor includes a main structure and a detection structure. The main structure includes a closed cavity extending along a first direction and penetrating the main structure, and multiple reflective sides surrounding the closed cavity. The detection structure is located within the closed cavity and includes an opaque circuit board and an optical transceiver unit. The optical transceiver unit includes a light emitting element and a light receiving element located on opposite sides of the circuit board along a second direction. The light emitting element emits a detection beam, and the light emission direction of the light emitting element is parallel to the second direction. The light receiving element generates a detection signal based on the detection beam transmitted to it via the multiple reflective sides, thereby detecting the liquid level of the liquid to be measured. The plane containing the reflective side corresponding to the light emission direction of the light emitting element has a first preset angle with the light emission direction of the light emitting element. If the liquid to be tested does not submerge the position where the detection beam is transmitted to the reflective side, the reflective side corresponding to the light emission direction of the light emitting element can totally reflect the detection beam transmitted thereto. If the height of the liquid level to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, the reflective side corresponding to the light emission direction of the light emitting element refracts the detection beam transmitted thereto into the liquid to be tested. The plane containing the reflective side corresponding to the light incident direction of the light receiving element has a second preset angle with the light incident direction of the light receiving element. This ensures that the transmission direction of the detection beam transmitted to the light receiving element via the reflective side corresponding to the light incident direction of the light receiving element is parallel to the light incident direction of the light receiving element, or the angle is less than the first preset value. Therefore, this liquid level sensor can achieve optical isolation between the light emitting element and the light receiving element based on an opaque circuit board, and realize beam transmission between the light emitting and light receiving elements based on multiple reflective sides of the main structure. This simplifies the structure of the liquid level sensor and reduces costs, thus facilitating the practical application of photoelectric liquid level sensors. Simultaneously, the reflective side corresponding to the light emission direction of the light emitting element can totally reflect the detection beam transmitted to it along the light emission direction. The detection beam transmitted sequentially to the light receiving element via the reflective side coincides with or has a small angle with the incident light direction of the light receiving element, thereby enabling more detection beams to be transmitted to the light receiving element and ensuring detection accuracy.

[0062] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0063] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0064] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0065] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid level sensor, characterized in that, include: The main structure includes a closed cavity extending along a first direction and a plurality of reflective side surfaces surrounding the closed cavity; wherein the first direction is parallel to the axial direction of the main structure. A detection structure is located in the enclosed cavity and includes an opaque circuit board and an optical transceiver unit. The optical transceiver unit includes a light emitting element and a light receiving element located on opposite sides of the circuit board along a second direction. The circuit board extends along a first direction, which is parallel to the plane of the circuit board, and the second direction is perpendicular to the plane of the circuit board. The light emitting element emits a detection beam, and the light emission direction of the light emitting element is parallel to the second direction; the light receiving element generates a detection signal based on the detection beam transmitted to it through the plurality of the reflective sides, so as to detect the liquid level of the liquid to be tested based on the detection signal; The reflective side corresponding to the light emission direction of the light emitting element has a first preset angle with the light emission direction of the light emitting element, so that if the height of the liquid level of the liquid to be tested is less than the height of the position where the detection beam is transmitted to the reflective side along the first direction, the reflective side corresponding to the light emission direction of the light emitting element will totally reflect the detection beam transmitted thereon. The reflective side corresponding to the incident light direction of the light receiving element has a second preset angle with the incident light direction of the light receiving element, so that the transmission direction of the detection beam reflected to the light receiving element by the reflective side corresponding to the incident light direction of the light receiving element is parallel to the incident light direction of the light receiving element, or the angle is less than a first preset value; the incident light direction of the light receiving element is parallel to the second direction.

2. The liquid level sensor according to claim 1, characterized in that, Along the light emission direction of the light emitting element, the plane containing the area of ​​the sidewall of the enclosed cavity corresponding to the light emitting element is perpendicular to the light emission direction of the light emitting element.

3. The liquid level sensor according to claim 1, characterized in that, Along the incident light direction of the light receiving element, the plane containing the area of ​​the sidewall of the enclosed cavity corresponding to the light receiving element is perpendicular to the incident light direction of the light receiving element.

4. The liquid level sensor according to claim 1, characterized in that, Along the direction surrounding the enclosed cavity, there is a third preset angle between adjacent reflective sides, such that if, along the first direction, the height of the liquid level to be tested is less than the height of the position where the detection beam is transmitted to the reflective side, the detection beam is sequentially totally reflected by the reflective side to the light receiving element; and if, along the first direction, the height of the liquid level to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, the reflective side refracts the detection beam transmitted thereon to the liquid to be tested.

5. The liquid level sensor according to claim 4, characterized in that, The main structure includes at least four reflective side surfaces along its axial direction. The first preset angle is 45°, the second preset angle is 45°, and the third preset angle is 90°. Along the first direction, if the height of the liquid level to be tested is less than the height of the position where the detection beam is transmitted to the reflective side surface, the detection beam is sequentially totally reflected by multiple reflective side surfaces to the light receiving element, and the transmission direction of the detection beam transmitted to the light receiving element is parallel to the incident light direction of the light receiving element.

6. The liquid level sensor according to claim 1, characterized in that, The detection structure includes a plurality of optical transceiver units arranged on the circuit board along the first direction; Along the first direction, the height of the liquid level of the liquid to be tested is less than the height of the position where the detection beam is transmitted to the reflective side. The light receiving element generates a first detection signal based on the detection beam transmitted thereto. The first detection signal is not less than a second preset value. Along the first direction, the height of the liquid level of the liquid to be tested is greater than or equal to the height of the position where the detection beam is transmitted to the reflective side, and the light receiving element generates a second detection signal based on the detection beam transmitted thereto, the second detection signal being no greater than a third preset value; The second preset value is greater than the third preset value.

7. The liquid level sensor according to claim 6, characterized in that, Along the first direction, the plurality of optical transceiver units include at least one optical transceiver unit located at both ends of the circuit board, and at least one optical transceiver unit located in the middle region of the circuit board; The closer to the end of the circuit board, the smaller the distance between adjacent optical transceiver units along the first direction.

8. The liquid level sensor according to claim 1, characterized in that, The main structure is a transparent prism extending along the first direction.

9. The liquid level sensor according to claim 1, characterized in that, The light emitting element is an infrared emitting tube, and the light receiving element is an infrared receiving tube.

10. An apparatus having a liquid container, characterized in that, Including liquid containers and level sensors; The liquid level sensor is located in the liquid container, and the liquid level sensor is the liquid level sensor according to any one of claims 1-9.

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