A human body sensor

Abstract

The present invention provides a human body sensor, comprising: a lens member, a sensing member, and a processing unit. A plurality of lens units are formed on a surface of the lens member facing the sensing member. The lens units at least include a first lens unit disposed opposite to the sensing member, and a second lens unit and a third lens unit sequentially arranged outward along the edge of the first lens unit. Wherein, the center of curvature of the first surface faces the side of the sensing member, and the radius of curvature of the first surface is set as R1; the focal length of the first lens unit is set as f1; the sensing member includes a second surface facing the lens member, and the vertical distance S1 between the first lens unit and the second surface satisfies the relational expression: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1. By reasonably controlling the range of S1, the human body sensor disclosed in the present invention can effectively shorten the distance between the first lens unit and the pyroelectric sensor while satisfying the detection distance, so as to reduce the thickness of the human body sensor.

Description

Technical Field

[0001] This application relates to the field of sensors, and particularly to a human body sensor. Background Art

[0002] Human body sensors are components frequently used in smart homes and security systems. Currently, most human body sensors on the market use pyroelectric infrared sensors as sensing elements. It can output corresponding voltage signals according to the irradiated infrared light, and the human body sensor judges whether someone has passed based on the change of the voltage signal. Pyroelectric materials are cheap, do not emit any beams themselves, and have extremely low power consumption, so they are widely used.

[0003] However, the detection range of pyroelectric infrared sensors is very small, and their effective detection distance is generally only 1m. Therefore, in practical applications, a lens sheet needs to be installed in front of the pyroelectric infrared sensor. Multiple lens units are arranged on the lens sheet, and each lens unit converges the infrared light to the pyroelectric infrared sensor, which can increase the detection distance and resolution of the human body sensor. The lens sheet of the existing human body sensor needs to be provided with more lens units, making the size of the lens sheet larger. Correspondingly, the distance from the lens sheet to the pyroelectric infrared sensor is larger, resulting in a larger thickness of the human body sensor. Summary of the Invention

[0004] In order to solve the problem of the large thickness of the human body sensor in the prior art, the present invention provides a human body sensor, including: a lens member, including a first surface for receiving light; a sensing member, capable of outputting a sensing signal in response to the irradiation of infrared light; a processing unit, electrically connected to the sensing member and configured to detect a human body in response to the sensing signal;

[0005] Wherein, a plurality of lens units are formed on the surface of the lens member facing the sensing member, and the light received by the first surface is converged to the sensing member through the lens units; the lens units at least include a first lens unit disposed opposite to the sensing member, and a second lens unit and a third lens unit sequentially arranged outward along the edge of the first lens unit; the center of curvature of the first surface faces the side of the sensing member, and the radius of curvature of the first surface is set as R1; the focal length of the first lens unit is set as f1; the sensing member includes a second surface facing the lens member, and the vertical distance S1 between the first lens unit and the second surface satisfies the relationship: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1.

[0006] Further, the focal lengths f2 of the second lens unit and f3 of the third lens unit satisfy the relationship: f1 ≤ f2 ≤ f3.

[0007] Further, the focal length f2 of the second lens unit and the focal length f3 of the third lens unit satisfy the relational expressions: f2 ≤ S1 + 0.45 × R1, and f3 ≤ S1 + 0.55 × R1.

[0008] Further, the relationship between the focal length f1 of the first lens unit and the focal length f2 of the second lens unit further satisfies the relational expression: f2 ≤ f1 + 0.2 × f1; the relationship between the focal length f1 of the first lens unit and the focal length f3 of the third lens unit further satisfies the relational expression: f3 ≤ f1 + 0.5 × f1.

[0009] Further, the perpendicular distance between the center of the first surface of the lens member and the second surface of the sensing member is less than the radius of curvature R1 of the first surface.

[0010] Further, the lens unit is configured as a Fresnel lens unit, and the light received by the first surface is converged to the sensing member via the Fresnel lens unit; the Fresnel lens unit is formed with a plurality of concentric annular teeth, and the pitch between adjacent annular teeth is set to 0.2 - 0.6 mm, and the light received by the first surface is refracted by the annular teeth and converged to the sensing member.

[0011] Further, the annular teeth are arranged in a ring around a first central axis; taking the plane where the first central axis is located as a first cross-section, each annular tooth forms a plurality of first generatrices on the first cross-section, and the angle between the first generatrix of each annular tooth and the first central axis gradually decreases from the center to the edge, wherein the first generatrix is a straight line segment.

[0012] Further, the first central axis of the third lens unit is located on the side of the third lens unit close to the first lens unit.

[0013] Further, the first central axis of the third lens unit is located on the side of the third lens unit away from the first lens unit.

[0014] Further, the first central axis of the third lens unit passes through the center of the third lens unit.

[0015] Further, the projected area of the first lens unit projected onto the plane where the second surface is located is set as a first projected area, the projected area of the second lens unit projected onto the plane where the second surface is located is set as a second projected area; the projected area of the third lens unit projected onto the plane where the second surface is located is set as a third projected area; wherein, the third projected area is respectively larger than the first projected area and the second projected area.

[0016] Further, the lens unit is configured as a convex lens unit, and the light received by the first surface is converged to the sensing element via the convex lens unit.

[0017] Further, the sensing element includes two positive temperature sensing units and two negative temperature sensing units. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation. Under the refraction of the convex lens unit, the positive temperature sensing unit and the negative temperature sensing unit form a plurality of detection regions on the side of the convex lens unit away from the sensing element. The light located in any one of the detection regions is converged to the positive temperature sensing unit or the negative temperature sensing unit via the corresponding convex lens unit. The number of the detection regions is greater than or equal to 124.

[0018] Further, the ratio of the radius of curvature R1 of the first surface to the arc height H of the first surface satisfies the relation: H / R1≥0.22.

[0019] Further, the distance between the centers of two adjacent convex lens units is greater than or equal to 2 mm.

[0020] Further, four detection regions are formed by the sensing element under the refraction of any one of the convex lens units. Among them, the number of the convex lens units is greater than or equal to 31.

[0021] Further, the lens units are spliced together.

[0022] Further, there are a plurality of second lens units, which are arranged annularly around the outer edge of the first lens unit; there are a plurality of third lens units, which are arranged annularly around the outer edge of the second lens unit.

[0023] Further, the first surface of the lens member is circular-arch-shaped, and the first lens unit, the second lens unit, and the third lens unit are arranged side by side along the bending direction of the circular-arch shape.

[0024] Further, a positive temperature sensing unit and a negative temperature sensing unit are arranged on the second surface of the sensing element. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation. The projection of the center of the first lens unit on the second surface is located between the positive temperature sensing unit and the negative temperature sensing unit.

[0025] Further, two positive temperature sensing units and two negative temperature sensing units with cross distribution are arranged on the second surface of the sensing element. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation. The projection of the center of the first lens unit on the second surface is surrounded by the positive temperature sensing unit and the negative temperature sensing unit.

[0026] Furthermore, the lens element is integrally formed of a white translucent material or a black transparent material.

[0027] Furthermore, the human body sensor further includes: a housing, the lens element covers the housing to form an accommodation cavity; a wireless communication unit, electrically connected to the processing unit and capable of transmitting wireless signals externally; a power supply unit, electrically connected to the sensing element and the wireless communication unit for providing electrical energy; the sensing element, the wireless communication unit and the power supply unit are accommodated in the accommodation cavity; the housing includes a base, and the base is disposed at one end of the housing away from the lens element for connecting to an external mounting surface.

[0028] The beneficial effects of the present invention at least include:

[0029] (1) For the human body sensor provided by the present invention, the vertical distance S1 between the first lens unit and the second surface satisfies the relationship: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1. By reasonably controlling the range of S1, while the human body sensor meets the detection distance, the distance between the first lens unit and the pyroelectric sensor can be effectively shortened to reduce the thickness of the human body sensor; at the same time, due to the shortening of the length of S1, the lens unit at the edge of the lens element can converge infrared light at a wider angle to the sensing element, further improving the detection angle of the human body sensor;

[0030] (2) In the embodiment of the present invention, by setting f1 ≤ f2 ≤ f3, the focal planes of the second lens unit and the third lens unit are close to the second surface of the sensing element to obtain better light condensing performance;

[0031] (3) By reasonably matching the focal lengths of the first lens unit, the second lens unit and the third lens unit to satisfy the relationship: f2 ≤ f1 + 0.2×f1, and f3 ≤ f1 + 0.5×f1, so that the human body sensor has a wider detection angle and more sensitive detection performance at the wide angle;

[0032] (4) By setting the vertical distance between the center of the first surface and the second surface to be less than the radius of curvature R1 of the first surface, the detection angle of the human body sensor is wider;

[0033] (5) By setting the first central axis of the third lens unit on the side away from the first lens unit, the optical center of the third lens unit can be biased to the side away from the first lens unit, and the refraction angle of the third lens unit becomes wider, thereby broadening the detection angle of the human body sensor;

[0034] (6) By setting the first central axis of the third lens unit on the side closer to the first lens unit, the detection angle of the human body sensor is reduced, facilitating the user to adjust the detection range of the human body sensor; at the same time, the distribution density of the detection area is higher, enhancing the detection sensitivity of the human body sensor.

[0035] (7) In the embodiment of the present invention, the number of detection areas is set to be greater than or equal to 124 (such as 220, 240, etc.). Thus, a sufficient number of detection areas can enable the human body sensor to achieve higher-resolution detection.

[0036] (8) Set the ratio of the radius of curvature R1 of the first surface to the arc height H of the first surface to satisfy the relationship: H / R1 ≥ 0.22, so that the bending radian of the first surface is larger, and correspondingly, the detection angle of the human body sensor is larger. When used in conjunction with a large number of detection areas, it can achieve a wider-angle high-resolution detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a cross-sectional view of an embodiment of the present invention;

[0039] Figure 2 It is a schematic structural diagram of a lens member in an embodiment of the present invention;

[0040] Figure 3 It is a schematic structural diagram of a lens member in an embodiment of the present invention;

[0041] Figure 4 It is a schematic diagram of the principle of convex lens light collection in an embodiment of the present invention;

[0042] Figure 5 It is a schematic structural diagram of an equal pitch Fresnel lens in an embodiment of the present invention;

[0043] Figure 6 It is a schematic structural diagram of an equal tooth height Fresnel lens in an embodiment of the present invention;

[0044] Figure 7 It is a schematic structural diagram of an induction member in an embodiment of the present invention;

[0045] Figure 8 It is a schematic diagram of the principle of forming a detection area in an embodiment of the present invention;

[0046] Figure 9It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0047] Figure 10 It is the Figure 9 amplified view of part A in

[0048] Figure 11 It is the Figure 9 cross-sectional view taken along line B-B in

[0049] Figure 12 It is a schematic diagram of the lens structure in the embodiment of the present invention;

[0050] Figure 13 It is a schematic diagram of the lens structure in the embodiment of the present invention;

[0051] Figure 14 It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0052] Figure 15 It is a schematic diagram of the lens structure in the embodiment of the present invention;

[0053] Figure 16 It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0054] Figure 17 It is a schematic diagram of the lens structure in the embodiment of the present invention;

[0055] Figure 18 It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0056] Figure 19 It is a schematic diagram of the lens structure in the embodiment of the present invention;

[0057] Figure 20 It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0058] Figure 21 It is a schematic diagram of the structure in the embodiment of the present invention;

[0059] Figure 22 It is a schematic diagram of the detection area distribution in the embodiment of the present invention;

[0060] Figure 23 It is a schematic diagram of the structure in the embodiment of the present invention;

[0061] Figure 24 It is a schematic diagram of the structure in the embodiment of the present invention;

[0062] Figure 25 It is a schematic diagram of the lens structure in the embodiment of the present invention.

[0063] Reference numerals:

[0064] 1. Lens element; 11. First surface; 2. Lens unit; 21. First lens unit; 22. Second lens unit; 23. Third lens unit; 24. Fourth lens unit; 25. Fifth lens unit; 26. Fresnel lens unit; 261. Annular teeth; 262. First generatrix; 263. First central axis; 27. Convex lens unit; 271. Optical axis; 3. Sensing element; 31. Second surface; 32. Positive temperature sensing unit; 33. Negative temperature sensing unit; 4. Detection area; 5. Housing; 6. Wireless communication unit; 7. Power supply unit; 8. Base; 81. Magnet; 9. Circuit board; 91. Processing unit. Detailed implementation

[0065] In the description of the present invention, the orientation or positional relationship indicated by terms such as "inner", "outer", "horizontal", "vertical", "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0066] In the description of the specification of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0067] In the description of the specification of the present invention, unless otherwise clearly defined and limited, terms such as "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0069] Based on Figures 1 - 25 , a human body sensor proposed by the present disclosure is specifically explained. Specifically, according to the first aspect of the embodiments of the present invention, a human body sensor is provided, such as Figure 1 , Figure 2 and Figure 3As shown in the figure, it includes: a lens member 1, including a first surface 11 for receiving light illumination; a sensing member 3, capable of outputting a corresponding voltage signal in response to the irradiation of infrared light; a processing unit 91, electrically connected to the sensing member 3 and configured to be capable of detecting a human body in response to the sensing signal; wherein, a plurality of lens units 2 are constructed on one side of the lens member 1 facing the sensing member 3, and the light received by the first surface 11 is converged to the sensing member 3 via the lens units 2; the lens units 2 at least include a first lens unit 21 disposed opposite to the sensing member 3, and a second lens unit 22 and a third lens unit 23 sequentially arranged outward along the edge of the first lens unit 21; the center of curvature of the first surface 11 faces the side of the sensing member 3, and the radius of curvature of the first surface 11 is set as R1; the focal length of the first lens unit 21 is set as f1; the sensing member 3 includes a second surface 31 facing the lens member 1, and the vertical distance S1 between the first lens unit 21 and the second surface 31 satisfies the relationship: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1.

[0070] Wherein, the sensing member 3 can be an infrared pyroelectric sensor, or other electronic components capable of outputting a changing electrical signal according to the change of infrared light irradiation. As Figure 1 shown in the figure, when a human body moves from the position of heat source 1 through the position of heat source 2 to the position of heat source 3, the infrared light emitted by the human body is converged to the sensing member 3 through the corresponding lens unit 2, and an infrared light spot is converged on the second surface 31 of the sensing member 3. The movement of the human body will cause the infrared light spot to move on the second surface 31. The second surface 31 is provided with a positive temperature sensing unit 32 and a negative temperature sensing unit 33, which can output corresponding voltage signals in response to the irradiation of infrared light. The fact that the processing unit 91 is electrically connected to the sensing member 3 can be understood as that the processing unit 91 and the sensing member 3 adopt a conductive connection method, such as welding to a circuit board connection, so that the sensing signal can be transmitted between the two. The fact that the processing unit 91 can detect a human body in response to the sensing signal can be understood as that the processing unit 91 has a voltage amplifier, which can amplify the voltage signal output by the sensing member 3 and judge whether someone has passed according to the change of the voltage signal. The lens unit 2 can be a convex lens, a Fresnel lens or other lenses that have a converging effect on light. Among the first lens units 21 included in the lens unit and disposed opposite to the sensing member 3, the so-called "oppositely disposed" can be understood as that one first lens unit 21 is disposed opposite to the sensing member 3, or multiple first lens units 21 are disposed opposite to the sensing member 3. When there are multiple first lens units 21, the multiple first lens units 21 are combined and disposed opposite to the sensing member 3. In an example, as Figure 23As shown, there are four first lens units 21, and after the four first lens units 21 are combined, they are arranged opposite to the sensing element 3. In another example, as Figure 3 shown, one first lens unit 21 is arranged at the center of the lens member 1 and is arranged opposite to the pyroelectric infrared sensor. Six second lens units 22 are arranged around the first lens unit 21, and twelve third lens units 23 are arranged around the six second lens units 22, so that the lens units 2 are evenly distributed. Correspondingly, the generated detection area 4 is symmetrically distributed around the central axis of the lens member 1. In one example, as Figure 21 and Figure 23 shown, the lens unit 2 is not limited to the first lens unit 21, the second lens unit 22 and the third lens unit 23, and may further include a fourth lens unit 24, a fifth lens unit 25, etc. arranged outside the third lens unit 23. The first surface 11 may be a plane, a curved surface or a spherical surface. When the first surface 11 is a plane, the radius of curvature R1 is infinite. The vertical distance S1 between the first lens unit 21 and the second surface 31 can be understood as the vertical distance between the bottom of the first lens unit 21 and the second surface 31, or the vertical distance between the center of the first lens unit 21 and the second surface 31. The second surface 31 is Figure 1 the upper surface of the sensing element 3 in

[0071] and is set as the side of the sensing element 3 for sensing infrared light.

[0072] To solve this problem, during the optical design, the inventor found through multiple creative experiments that when S1 ≤ f1, although the light condensing performance of the lens unit 2 weakens and the converged infrared light spot becomes larger, according to the principle of light condensation by a convex lens, the larger the object distance, the smaller the infrared light spot converged by the lens. That is, for a relatively distant infrared heat source, even if the distance S1 between the second surface 31 and the first lens unit 21 is shortened, a relatively small infrared light spot will still be converged on the second surface 31, which can successfully trigger the sensing element 3 with little impact on the detection distance. Moreover, the loss of the detection distance can be compensated by increasing the light transmittance of the lens unit 2 and adjusting the amplification factor of the voltage amplifier. Therefore, shortening the S1 has little impact on the detection distance of the human body sensor. When S1 is shortened to S1 < 0.5×f1, the light condensing performance of the lens unit 2 weakens significantly, and a larger and blurred infrared light spot is converged on the second surface 31, which has a greater impact on the detection distance of the human body sensor. When testing a heat source at a long distance, the sensitivity of the human body sensor decreases significantly. Therefore, in the design of the size of S1 in the embodiments of the present invention, f1 ≥ S1 ≥ 0.5×f1 is controlled, so that while the human body sensor meets the detection distance, the distance between the first lens unit and the pyroelectric sensor can be effectively shortened to reduce the thickness of the human body sensor.

[0073] Further, the adjustable range of S1 is directly related to the curvature radius R1 of the first surface 11. When the curvature radius R1 is small, as Figure 23 shown, the bending degree of the first surface 11 is large, and the angular deviation of the optical axes 271 of the lens units is large. At this time, if S1 is reduced too much, the light condensing ability of the lens unit 2 near the edge will be greatly weakened, and it may occur that the lens unit 2 at the edge cannot converge the light to the sensing element 3. Therefore, when R1 is small, the adjustable range of S1 should not be too large; when the curvature radius R1 is large, as Figure 21 shown, the bending degree of the first surface 11 is relatively gentle, and the inclination angle difference of the optical axes 271 of the lens units 2 is small. At this time, shortening S1 has a smaller impact on the difference in the light condensing performance between the lenses, and the lens unit 2 at the edge can converge the infrared light to the sensing element 3 unimpeded. Therefore, when R1 is large, the adjustable range of S1 becomes larger. In summary, the adjustable range of S1 is positively correlated with the curvature radius R1 of the first surface 11. Through multiple creative experiments by the inventor, it is found that an appropriate range for the adjustable range of S1 is 0.4 times of R1.

[0074] Therefore, in the above solution, by setting the vertical distance S1 between the first lens unit 21 and the second surface 31 to satisfy the formula f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1, the range of S1 is reasonably controlled, so that while the human body sensor meets the detection distance, the distance between the first lens unit 21 and the pyroelectric sensor can be effectively shortened, reducing the thickness of the human body sensor; at the same time, as Figure 1 shown, due to the shortening of the length of S1, the lens unit 2 at the edge of the lens member 1 can converge infrared light at a wider angle to the sensing member 3, further improving the detection angle of the human body sensor. As Figure 9 shown, the detection angle can be understood as that all detection areas 4 of the human body sensor combine to form a conical detection range, and the central angle of the detection range is the detection angle. In a specific embodiment, as Figure 1 、 Figure 9 and Figure 10 shown, R1 = 37mm, S1 = 7.8mm, f1 = 10mm, and the detection angle of the human body sensor is 120 degrees.

[0075] In some embodiments, as Figure 2 and Figure 3 shown, the focal length f2 of the second lens unit 22 and the focal length f3 of the third lens unit 23 satisfy the relationship: f1 ≤ f2 ≤ f3. As Figure 4 shown, according to the refraction principle of a convex lens: the light rays parallel to the principal optical axis of the convex lens can be converged by the convex lens to the focal point; the light rays parallel to the secondary optical axis can be converged by the convex lens to the secondary focal point on the focal plane. The principal optical axis is an axis perpendicular to the center of the convex lens, and the focal plane is a plane perpendicular to the principal optical axis and located at the position of the principal focal point; the secondary optical axis can be understood as an axis parallel to the incident light ray and passing through the optical center. According to the above principle, the outgoing light ray corresponding to any incident light ray can be drawn. Thus, the optical path diagram of the infrared light radiated by each heat source in Figure 1 is obtained. From Figure 1 it can be seen that for the lens unit 2 at the edge of the lens member 1, its optical axis deviates from the sensing member 3. In this embodiment, by setting f1 ≤ f2 ≤ f3, the focal planes of the second lens unit 22 and the third lens unit 23 are close to the second surface 31 of the sensing member 3 to obtain better light condensing performance.

[0076] Furthermore, the focal length f2 of the second lens unit 22 and the focal length f3 of the third lens unit 23 satisfy the relationship: f2 ≤ S1 + 0.45×R1, and f3 ≤ S1 + 0.55×R1. By setting the ranges of f2 and f3, the light condensing performance of the second lens unit 22 and the third lens unit 23 is guaranteed, so that the detection distance and sensitivity of the human body sensor meet the requirements.

[0077] Furthermore, the relationship between the focal length f1 of the first lens unit 21 and the focal length f2 of the second lens unit 22 further satisfies the relational expression: f2 ≤ f1 + 0.2×f1; the relationship between the focal length f1 of the first lens unit 21 and the focal length f3 of the third lens unit 23 further satisfies the relational expression: f3 ≤ f1 + 0.5×f1. By reasonably matching the focal lengths of the first lens unit 21, the second lens unit 22, and the third lens unit 23, the human body sensor has a wider detection angle and more sensitive detection performance at wide angles.

[0078] Furthermore, as Figure 1 , Figure 21 , Figure 23 and Figure 24 shown, the vertical distance between the center of the first surface 11 of the lens member 1 and the second surface 31 of the sensing member 3 is less than the radius of curvature R1 of the first surface 11. That is, the center of curvature of the first surface 11 is located below the second surface 31, so that the lens unit 2 at the edge can converge infrared light at a wider angle to the second surface 31. Correspondingly, the detection angle of the human body sensor is wider.

[0079] Furthermore, as Figures 12 - 19 shown, the lens unit 2 is configured as a Fresnel lens unit 26, and the light received by the first surface 11 is converged to the sensing member 3 via the Fresnel lens unit 26; the Fresnel lens unit 26 is formed with a plurality of concentric annular teeth 261, and the pitch between adjacent annular teeth 261 is set to 0.2 - 0.6 mm, and the light received by the first surface 11 is refracted by the annular teeth 261 and converged to the sensing member 3. Among them, the Fresnel lens is also called a threaded lens. Compared with an ordinary lens, its main characteristics are high light transmittance, thinness, and small volume. As Figure 5 and Figure 6 shown, the formation principle of the Fresnel lens is as follows: the effective refraction of a plano-convex lens occurs on its convex surface. The curvature of the convex surface can be retained, the material without optical effect inside can be deleted, and the convex surface with optical effect is cut into circular ring segments and translated downward to the bottom to form a series of annular teeth 261, thus forming a Fresnel lens. The Fresnel lens can be regarded as a thinned convex lens. From its principle, it can be seen that each annular tooth 261 of the Fresnel lens retains the corresponding curvature characteristics of the convex lens, but is thinner and lighter.

[0080] The embodiment of the present invention adopts the Fresnel lens unit 26, which is beneficial to increasing the area of the lens unit 2, thinning the thickness of the lens unit 2, increasing the light transmittance, and improving the light-gathering performance of the lens unit 2, thereby improving the detection distance of the human body sensor. The Fresnel lens adopted in the embodiment of the present invention includes an equal-pitch Fresnel lens ( Figure 5 ) and an equal-tooth-height Fresnel lens (Figure 6 ), the equal pitch Fresnel lens can be understood as that the pitch between two adjacent annular teeth 261 is equal and the annular teeth 261 are evenly spaced. The advantage of such a setting is that it is convenient for design and processing. In order to reduce the processing difficulty, the arc surface of the annular teeth 261 can be simplified to a conical surface for processing. However, the disadvantage of the equal pitch design is that the tooth height of the annular teeth 261 near the edge is greater than that of the annular teeth 261 at the center, resulting in the light transmittance of the annular teeth 261 near the edge being less than that of the annular teeth 261 at the center. The equal tooth height Fresnel lens can be understood as that the tooth height h of two adjacent annular teeth 261 is equal. The advantage of such a design is that the slope of the central part of the lens unit 2 is small, so a large area at the center of the lens unit 2 does not need to cut the annular teeth 261, presenting as a small convex lens, with lower processing difficulty. The central part does not need to simplify the arc surface to a conical surface during processing, so the light condensing performance is better, and the convex surface of the small convex lens is a continuous surface without being cut, having better light condensing property. However, the pitch of the annular teeth 261 of the equal tooth height Fresnel lens is very small near the edge, and the processing difficulty is too high. Therefore, when designing a small equal tooth height Fresnel lens, the number of teeth will not be many, so it is not conducive to making it thin.

[0081] In this embodiment, the pitch range of each annular tooth 261 is designed to be 0.2 - 0.6 mm to ensure easy processability and at the same time avoid the Fraunhofer diffraction having a greater impact on the light condensing performance of the lens unit 2.

[0082] Furthermore, as Figure 5 shown, the annular teeth 261 are arranged in a ring around a first central axis 263; taking the plane where the first central axis 263 is located as the first cross-section, each annular tooth 261 forms a plurality of first generatrices 262 on the first cross-section, and the included angle between the first generatrix 262 of each annular tooth 261 and the first central axis 263 gradually decreases from the center to the edge, where the first generatrix 262 is a straight line segment. Since the Fresnel lens adopted in the embodiment of the present application is not used for imaging technology but only for converging light, in order to reduce the processing difficulty and cost, the first generatrix 262 of the Fresnel lens is simplified from an arc to a straight line segment. Although this has a certain impact on the light condensing performance of the lens unit 2, it can still meet the usage conditions of the human body sensor. For the equal tooth height Fresnel lens, as Figure 6 shown, because the radian of its central part is small, a small convex lens will be formed at the center of the equal tooth height Fresnel lens, and the height of the small convex lens is equal to the tooth height of other annular teeth 261. Since the area of this small convex lens is large and the processing difficulty is not high, when designing the equal tooth height Fresnel lens, only the generatrix of the annular teeth 261 can be simplified without simplifying the small convex lens at its center, so that the Fresnel lens can further improve the light condensing performance on the premise of ensuring easy processing.

[0083] In some embodiments, asFigure 12 , Figure 13 and Figure 15 As shown in Figure 12 , Figure 13 , and Figure 15 , the first central axis 263 of the third lens unit 23 passes through the center of the third lens unit 23. Herein, the center of the third lens unit 23 may be the geometric center of the third lens unit 23 or a position near the center of the third lens unit 23. The first central axis 263 passes through the center of the third lens unit 23, that is, the annular teeth 261 of the third lens unit 23 are arranged with the center of the third lens unit 23 as the center of the circle. The advantage of such an arrangement is that when using a Fresnel lens with equal pitch, it is beneficial to reduce the tooth height of the annular teeth 261 at the edge of the third lens unit 23, so that the tooth heights of the annular teeth 261 at the edges of the first lens unit 21, the second lens unit 22, and the third lens unit 23 are not very different, facilitating the connection at the edges of the three, thereby reducing the processing difficulty and preventing the situation of being forced to increase the focal length in order to reduce the tooth height, which is beneficial to accurately controlling the focal lengths of the respective lens units 2.

[0084] As Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown in Figure 7 , Figure 8 , Figure 9 , and Figure 10 , the sensing member 3 includes two positive temperature sensing units 32 and two negative temperature sensing units 33. The positive temperature sensing unit 32 outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit 33 outputs a negative voltage in response to infrared radiation. Under the refraction of the lens unit 2, the positive temperature sensing unit 32 and the negative temperature sensing unit 33 form a plurality of detection regions 4 on the side of the lens unit 2 away from the sensing member 3. The light located in any one of the detection regions 4 is converged to the positive temperature sensing unit 32 or the negative temperature sensing unit 33 through the corresponding lens unit 2. The detection region 4 can be understood as the region where the infrared light emitted by the heat source can be converged to the positive temperature sensing unit 32 or the negative temperature sensing unit 33 through the lens member 1. As Figure 8As shown, according to the principle of convex lens focusing described above, two fan-shaped regions generated after the positive temperature sensing unit 32 and the negative temperature sensing unit 33 are refracted by the first lens unit 21 can be drawn, namely the bright region and the dark region. The infrared light emitted by the heat source located in the bright region can be at least partially converged to the positive temperature sensing unit 32 through the first lens unit 21, thereby prompting the positive temperature sensing unit 32 to undergo charge transfer and generate a positive voltage; the infrared light emitted by the heat source located in the dark region can be at least partially converged to the negative temperature sensing unit 33 through the first lens unit 21, thereby prompting the negative temperature sensing unit 33 to undergo charge transfer and generate a negative voltage. The overlapping region between the bright region and the dark region is the overlapping area. The infrared light emitted by the heat source located in the overlapping area is partially converged to the positive temperature sensing unit 32 to generate a positive voltage, and the other part is converged to the negative temperature sensing unit 33 to generate a negative voltage. There is a blind area between the bright region and the dark region. The infrared light emitted by the heat source located in the blind area is converged between the positive temperature sensing unit 32 and the negative temperature sensing unit 33, and in this case, the heat source cannot be detected. When a heat source moves from Figure 8 above the dark region in the middle into the dark region, the infrared light emitted by the heat source forms a light spot that converges on the second surface 31 and enters the area where the negative temperature sensing unit 33 is located from below the negative temperature sensing unit 33; when the heat source is located in the dark region, the negative temperature sensing unit 33 senses the infrared radiation and generates a negative voltage. When the heat source moves in a direction away from the lens member 1, the light spot formed by the heat source on the second surface 31 gradually becomes smaller, and when the heat source moves in a direction closer to the lens member 1, the light spot formed by the heat source on the second surface 31 gradually becomes larger. There is a position where the light spot formed by the heat source on the second surface 31 exactly covers the positive temperature sensing unit 32 or the negative temperature sensing unit 33.

[0085] Furthermore, a layer of filter (not shown in the figure) is covered on the surfaces of the positive temperature sensing unit 32 and the negative temperature sensing unit 33 to filter out a part of the light other than infrared light, thereby reducing the interference of other light.

[0086] According to the above principle, as Figure 9 、 Figure 10 and Figure 11As shown, under the refraction of each lens unit 2, the sensing element 3 generates a plurality of bright areas and dark areas, that is, the detection area 4. Specifically, the sensing element 3 is a quad-element pyroelectric sensor or a dual-element pyroelectric sensor or a single-element pyroelectric sensor. Among them, the quad-element pyroelectric sensor has two positive temperature-sensing units 32 and two negative temperature-sensing units 33, the dual-element pyroelectric sensor has one positive temperature-sensing unit 32 and one negative temperature-sensing unit 33, and the single-element pyroelectric sensor only has one positive temperature-sensing unit 32 or one negative temperature-sensing unit 33. If the sensing element 3 uses a dual-element pyroelectric sensor, each lens unit 2 correspondingly generates 2 detection areas 4. If the sensing element 3 uses a single-element pyroelectric sensor, each lens unit 2 correspondingly generates 1 detection area 4; in a preferred embodiment, the sensing element 3 uses a quad-element pyroelectric sensor, and its positive temperature-sensing unit 32 and negative temperature-sensing unit 33 generate 4 detection areas 4 under the refraction of a lens unit 2, so that the number of detection areas 4 increases significantly, thereby improving the detection resolution of the human body sensor and making the detection sensitivity of the human body sensor higher. When the detected human body has a small movement, the human body sensor can also detect it. The lens element 1 used in this embodiment is as Figure 3 shown, which has 19 lens units 2, including 1 first lens unit 21, 6 second lens units 22, and 12 third lens units 23. Under the refraction of the lens unit 2, the sensing element 3 generates 76 detection areas 4, as Figure 11 shown as Figure 9 the B-B cross-sectional view of the detection area 4 shown. It can be seen from the figure that the distribution of the detection area 4 corresponds to the lens unit 2.

[0087] Furthermore, as Figure 7 and Figure 1 shown, the sensing element 3 is a quad-element pyroelectric sensor, and two positive temperature-sensing units 32 and two negative temperature-sensing units 33 are arranged in a cross distribution on the second surface 31. The projection of the center of the first lens unit 21 on the second surface 31 is surrounded by the positive temperature-sensing unit 32 and the negative temperature-sensing unit 33. This makes the detection areas 4 of the human body sensor symmetrically distributed along the central axis of the sensing element 3, and the detection angle is more controllable.

[0088] In some embodiments, the sensing element 3 is a dual-element pyroelectric sensor, and one positive temperature-sensing unit 32 and one negative temperature-sensing unit 33 are arranged on the second surface 31. The projection of the center of the first lens unit 21 on the second surface 31 is located between the positive temperature-sensing unit 32 and the negative temperature-sensing unit 33. This makes the detection areas 4 of the human body sensor symmetrically distributed along the central axis of the sensing element 3, and the detection angle is more controllable.

[0089] Furthermore, as Figure 7As shown, the sensing element 3 is configured as a cylindrical rotating body, and its central axis does not pass through the positive temperature sensing unit 32 and the negative temperature sensing unit 33. During the design and assembly process, aligning the central axis of the sensing element 3 with the center of the first lens unit 21 can make the projection of the center of the first lens unit 21 on the second surface 31 be surrounded between the positive temperature sensing unit 32 and the negative temperature sensing unit 33, so as to control the detection area 4 of the human body sensor to be symmetrically distributed along the central axis of the sensing element 3, reducing the design and assembly difficulty.

[0090] When the lens unit 2 is a Fresnel lens unit 26 as shown in Figure 13 the number of the lens units 2 is 17, including 1 first lens unit 21, 8 second lens units 22, and 8 third lens units 23. Correspondingly, the number of the detection areas 4 is 68. The first central axis 263 of each lens unit 2 passes through its own center. The distribution diagram of the detection areas 4 generated by the sensing element 3 under the refraction of each lens unit 2 is as shown in Figure 14 As can be seen from the figure, the detection area 4 gradually becomes larger from the center to the edge, and the density gradually becomes lower, that is, the detection sensitivity near the center of the lens element 1 is higher, which conforms to the conventional usage habits of the human body sensor. And in this embodiment, the area of the Fresnel lens is relatively large, which is beneficial to improving the detection distance of the human body sensor.

[0091] Furthermore, as shown in Figures 13 - 25 the lens units 2 are spliced together, so that the proportion of the effective refraction surface of the lens element 1 is higher, and the utilization rate of the inner surface of the lens element 1 is higher, thereby improving the detection distance and sensitivity of the human body sensor. Among them, the splicing method between the lens units 2 can be polygon splicing, arc splicing or other implementable splicing methods.

[0092] Furthermore, as shown in Figure 3 Figure 13 Figure 14 and Figure 19 there are multiple second lens units 22, which are arranged annularly around the outer edge of the first lens unit 21; there are multiple third lens units 23, which are arranged annularly around the outer edge of the second lens unit 22. Further, the lens element 1 can be spherical shell-shaped or planar, and the spherical shell-shaped lens element 1 is beneficial to improving the detection angle of the human body sensor. In some embodiments, as shown in Figure 15 Figure 17 Figure 21 and Figure 22 the lens unit 2 is not limited to the first lens unit 21, the second lens unit 22, and the third lens unit 23, and may further include a fourth lens unit 24, a fifth lens unit 25, etc. arranged outside the third lens unit 23. ​​​​

[0093] In another preferred embodiment, as Figure 15 shown, the number of the lens units 2 is 29, including 1 first lens unit 21, 8 second lens units 22, 8 third lens units 23, and 12 fourth lens units 24 surrounding the outside of the third lens units 23. Correspondingly, the number of the detection areas 4 is 116. The first central axis 263 of each lens unit 2 passes through its own center. The distribution diagram of the detection areas 4 is as Figure 16 shown. It can be seen from the figure that the detection areas 4 gradually become larger from the center to the edge, and the density gradually becomes lower, that is, the detection sensitivity near the center of the lens member 1 is higher, which conforms to the conventional usage habits of the human body sensor. Compared with the embodiment where the number of the lens units 2 is 17, the number of the lens units 2 in this embodiment is larger, and the detection sensitivity of the human body sensor is higher, and it is easier to detect the minute movements of the human body. However, compared with the embodiment where the number of the lens units 2 is 17, the area of each single lens unit 2 in this embodiment is smaller, and correspondingly, the infrared light converged by each single lens unit 2 is less, resulting in a shorter detection distance of the human body sensor. Further, as Figure 13 and Figure 19 shown, there is a distance between the outer edge of the third lens unit 23 and the edge of the lens member 1 where no lens unit 2 is provided. The beneficial effect of such a design is that it is convenient for demolding during injection molding, reduces the processing difficulty of the mold; and can narrow the detection angle, making the detection directivity stronger, so as to facilitate the user to adjust the detection range during use.

[0094] In some embodiments, as Figure 17 and Figure 24 shown, the first central axis 263 of the third lens unit 23 is located on the side of the third lens unit 23 away from the first lens unit 21, including that the first central axis 263 of the third lens unit 23 is located outside, inside or at the edge of the third lens unit 23. By setting the first central axis 263 of the third lens unit 23 on the side of the third lens unit 23 away from the first lens unit 21, the optical center of the third lens unit 23 can be biased towards the side away from the first lens unit 21, and the refraction angle of the third lens unit 23 becomes wider, thereby widening the detection angle of the human body sensor. In a specific embodiment, as Figure 17 shown, the first central axis 263 of the third lens unit 23 is located at the edge and on the side away from the first lens unit 21. A plurality of fourth lens units 24 are arranged surrounding the outside of the third lens unit 23. The first central axis 263 of the fourth lens units 24 is located outside and on the side away from the first lens unit 21, so that the lens member 1 can converge the infrared light at a wider angle to the sensing member 3, and can improve the detection angle of the human body sensor. The distribution of the detection areas 4 in this embodiment is as Figure 18As shown, it can be seen from the figure that the detection area 4 near the edge has a larger detection angle and a smaller distribution density, while the detection area 4 at the center has a larger distribution density, that is, the detection sensitivity at the center is higher, which is suitable for detecting heat sources in the distance, and the detection sensitivity near the edge is lower, which is suitable for detecting heat sources nearby. This conforms to the conventional usage habits of human body sensors. When the bending radian of the first surface 11 of the lens member 1 is small, this method can be used to make up for the shortage of the detection angle.

[0095] In this embodiment, as Figure 17 shown, the lens unit 2 covers the inner surface of the lens member 1, and no blank interval is provided between the outermost lens unit 2 and the edge of the lens member 1, so that the detection angle of the human body sensor is further increased.

[0096] In some embodiments, as Figure 19 shown, the first central axis 263 of the third lens unit 23 is located on the side of the third lens unit 23 close to the first lens unit 21. The beneficial effect of this design is that it makes the detection angle of the human body sensor smaller, which is convenient for users to adjust the detection range of the human body sensor. At the same time, the distribution diagram of the detection area 4 of this embodiment is as Figure 20 shown. By setting the first central axis 263 of the third lens unit 23 on the side close to the first lens unit 21, the detection area 4 is more concentrated and the distribution density of the detection area 4 is higher, so that the detection sensitivity of the human body sensor is improved.

[0097] Furthermore, as Figure 13 、 Figure 15 and Figure 17 shown, the projected area of the first lens unit 21 projected onto the plane where the second surface 31 is located is set as the first projected area, and the projected area of the second lens unit 22 projected onto the plane where the second surface 31 is located is set as the second projected area; the projected area of the third lens unit 23 projected onto the plane where the second surface 31 is located is set as the third projected area; wherein, the third projected area is respectively larger than the first projected area and the second projected area. The beneficial effect of this design is: it can enhance the light-gathering ability of the third lens unit 23. As Figure 1 can be seen, the lens unit 2 near the edge of the lens member 1 is inclined relative to the sensing member 3, and the closer to the edge of the lens member 1, the greater the inclination degree and the corresponding worse the light-gathering performance. In this solution, the area of the lens unit 2 near the edge is increased, so as to make up for the loss of light intensity caused by inclined light-gathering and improve the detection distance of the human body sensor at a wide angle.

[0098] Furthermore, as Figure 3 、 Figure 21 、 Figure 23 andFigure 25 As shown, the lens unit 2 is configured as a convex lens unit 27, and the light received by the first surface 11 is converged to the sensing element 3 via the convex lens unit 27. The convex lens unit 27 can be understood as a small convex lens. Compared with the Fresnel lens unit 26, the convex lens unit 27 has the following characteristics: ① lower design difficulty; ② easier to process and lower processing cost; ③ the single lens unit 2 is smaller, so that the number of lens units 2 is larger, and thus the number of detection areas 4 of the human body sensor is larger; ④ the convex lens unit 27 is thicker, which has a greater obstruction to light, and a material with high light transmittance needs to be used to increase the light collection efficiency, so that the light transmissive member becomes more transparent, affecting the aesthetics; ⑤ when the volume of the convex lens unit 27 is large, the thickness is too thick and the obstruction to light is too large, so generally the volume of the convex lens unit 27 is small, and under the same material, the light collection performance is inferior to that of the Fresnel lens.

[0099] In some embodiments, as Figure 21 、 Figure 23 and Figure 25 shown, the number of the detection areas 4 is greater than or equal to 124. Further, four detection areas 4 are formed by the refraction of the sensing element 3 under any convex lens unit 27; wherein, the number of the convex lens units 27 is greater than or equal to 31. When the detection angle of the human body sensor is relatively wide, its detection range will be very large, and sufficient detection areas 4 need to be provided to ensure meeting the requirements of detection sensitivity and avoiding the situation of not detecting the human body. The inventor found that when the number of detection areas 4 is greater than or equal to 124, the detection sensitivity requirement of the detection area 4 greater than 110° can be met. In a specific embodiment, as Figure 25 shown, a four-element pyroelectric sensor is used in combination with a lens member 1 having 31 convex lens units 27 to provide 124 detection areas 4 for the human body sensor. The lens unit 2 includes 1 first lens unit 21 disposed opposite to the sensing element 3, 6 second lens units 22 disposed around the first lens unit 21, 12 third lens units 23 disposed around the second lens unit 22, and 12 fourth lens units 24 disposed around the third lens unit 23. Each lens unit 2 is arranged in a polygon splicing manner, making the overall volume of the lens member 1 smaller.

[0100] In some embodiments, as Figure 21 、 Figure 22 and Figure 23 shown, the number of the detection areas 4 is greater than or equal to 220. As the number of detection areas 4 increases, the detection sensitivity will be further improved, enabling the human body sensor to sense more subtle movements of the human body. In a specific embodiment, as Figure 21As shown in the figure, a four-element pyroelectric sensor is used in combination with a lens unit 1 having 55 convex lens units 27 to provide 220 detection areas 4 for the human body sensor (such as Figure 22 shown). The lens unit 2 includes one first lens unit 21 disposed opposite to the sensing element 3, six second lens units 22 disposed around the first lens unit 21, twelve third lens units 23 disposed around the second lens unit 22, eighteen fourth lens units 24 disposed around the third lens unit 23, and eighteen fifth lens units 25 disposed around the fourth lens unit 24. Each lens unit 2 is arranged in a polygonal splicing manner. In this embodiment, the first surface 11 of the lens unit 1 is spherical shell-shaped, and the vertical distance S1 between the first lens unit 21 and the second surface 31 is set as: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1. By reasonably controlling the range of S1, while the human body sensor meets the detection distance, the distance between the first lens unit 21 and the pyroelectric sensor can be effectively shortened, and the thickness of the human body sensor can be reduced; at the same time, due to the shortening of the length of S1, the lens unit 2 located at the edge of the lens unit 1 can converge infrared light at a wider angle to the sensing element 3, further improving the detection angle of the human body sensor. In this embodiment, the detection angle of the human body sensor can reach 120°, and with 220 detection areas 4, wide-angle high-resolution detection can be achieved.

[0101] In some embodiments, such as Figure 23 shown, the number of the detection areas 4 is greater than or equal to 240. In a specific embodiment, such as Figure 23 shown, a four-element pyroelectric sensor is used in combination with a lens unit 1 having 60 convex lens units 27, so that the human body sensor has 240 detection areas 4. The lens unit 2 includes four first lens units 21 disposed opposite to the sensing element 3, eight second lens units 22 disposed around the first lens unit 21, twelve third lens units 23 disposed around the second lens unit 22, sixteen fourth lens units 24 disposed around the third lens unit 23, and twenty fifth lens units 25 disposed around the fourth lens unit 24. Each lens unit 2 is arranged in an arc-shaped splicing manner. In this embodiment, the first surface 11 of the lens unit 1 is spherical shell-shaped, and its radian is close to a hemisphere, so that the detection angle of the human body sensor is wider. In this embodiment, the detection angle can reach 160°, and with 240 detection areas 4, wider-angle high-resolution detection can be achieved.

[0102] Furthermore, as shown in Figure 21 and Figure 23As shown, the ratio of the curvature radius R1 of the first surface 11 to the arc height H of the first surface 11 satisfies the relationship: H / R1≥0.22. The curvature of the first surface 11 is larger, and the corresponding detection angle of the human body sensor is larger. When used with a large number of detection areas 4, a wider-angle high-resolution detection can be achieved.

[0103] Furthermore, if Figure 21 , Figure 23 and Figure 25 As shown, the distance between the centers of two adjacent convex lens units 27 is greater than or equal to 2 mm, so that a single convex lens unit 27 has a sufficient light receiving area to ensure its light focusing performance, so that the detection distance meets the requirements.

[0104] In some embodiments, Figure 24 As shown, the first surface 11 of the lens component 1 is an arch, wherein the first lens unit 21, the second lens unit 22 and the third lens unit 23 are arranged side by side along the bending direction of the arch. The arch can be understood as a rectangular shell 5 that is bent along the long side to present a certain curvature to form the arch. The parallel arrangement along the bending direction of the arch can be understood as that the first lens unit 21, the second lens unit 22 and the third lens unit 23 are sequentially arranged from the center of the arch toward both sides in the bending direction of the arch. The advantage of such an arrangement is that the detection angle of the human body sensor in the bending direction of the arch can be increased. When in use, the bending direction of the arch is set horizontally so that the detection angle of the human body sensor in the horizontal direction is wider, which meets the most usage scenarios of the human body sensor. At the same time, the bending direction of the arch is set horizontally to avoid detecting heat sources with lower heights, such as small animals, and reduce the occurrence of false triggering. Further, as Figure 24 As shown, the lens unit 2 of the dome-shaped lens element 1 adopts a Fresnel lens unit 26, and the first central axis 263 of each Fresnel lens is located on a side away from the center of the lens element 1, so that the detection range of the human body sensor is wider.

[0105] Furthermore, the lens component 1 is integrally formed of a white translucent material or a black transparent material. The use of a white translucent material can prevent the electronic components inside the human body sensor from being exposed, and the white translucent material has good light transmittance, which has a gain effect on the detection distance. In a specific embodiment, the lens component 1 is integrally injection molded of white translucent HDPE high-density polyethylene. In addition, the lens component 1 is made of a black transparent material, which can conceal the optical texture on the inside of the lens component 1, and at the same time can prevent the electronic components inside the human body sensor from being exposed, and the transparent material has good light transmittance, which has a gain effect on the detection distance.

[0106] Furthermore, ifFigure 1 As shown, the human body sensor further includes: a housing 5, and the lens member 1 covers the housing 5 to form a receiving cavity; a wireless communication unit 6, electrically connected to the processing unit 91, capable of transmitting wireless signals externally; a power supply unit 7, electrically connected to the sensing member 3 and the wireless communication unit, for providing electrical energy; the sensing member 3, the wireless communication unit, and the power supply unit 7 are accommodated in the receiving cavity; the housing 5 includes a base 8, and the base 8 is disposed at one end of the housing 5 away from the lens member 1 for connecting to an external mounting surface. Wherein, the receiving cavity can be a closed receiving cavity or an open receiving cavity; the electrical connection can be understood as a conductive connection method, including soldering through a circuit board 9, wire connection, contact conductive connection, or other implementable methods. When the voltage signal output by the sensing member 3 is greater than a threshold value, the processing unit 91 determines that someone has passed by, and then the wireless communication unit 6 transmits a wireless signal externally. The power supply unit 7 can be powered by a battery module or can be connected to an external power supply by a wiring module. The base 8 is connected to the external mounting surface, which can be a fixed connection or a detachable connection. In a preferred embodiment, as shown in the figure, a magnet 81 is provided inside the bottom case, which can magnetically attract the human body sensor to the external mounting surface or a bracket.

[0107] Further, as Figure 1 shown, when the first surface 11 of the lens member 1 faces outward and the second surface 31 of the lens unit 2 faces inward, it can prevent the lens unit 2 from accumulating dust and being difficult to clean, which affects the light transmittance.

[0108] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed claim.​

Claims

1. A human body sensor, characterized in that, Comprising: A lens member, including a first surface for receiving light illumination; A sensing member capable of outputting a sensing signal in response to the irradiation of infrared light; A processing unit electrically connected to the sensing member and configured to be capable of detecting a human body in response to the sensing signal; Wherein, on one side of the lens member facing the sensing member, a plurality of lens units are constructed, and the light received by the first surface is converged to the sensing member via the lens units; The lens units at least include a first lens unit disposed opposite to the sensing member, and a second lens unit and a third lens unit sequentially arranged outward along the edge of the first lens unit; The center of curvature of the first surface faces the side of the sensing member, and the radius of curvature of the first surface is set as R1; the focal length of the first lens unit is set as f1; the sensing member includes a second surface facing the lens member, and the vertical distance S1 between the first lens unit and the second surface satisfies the relational expression: f1 - 0.4×R1 ≤ S1 ≤ f1, and S1 ≥ 0.5×f1.

2. The human body sensor according to claim 1, characterized in that, The focal length f2 of the second lens unit and the focal length f3 of the third lens unit satisfy the relational expression: f1 ≤ f2 ≤ f3.

3. The human body sensor according to claim 2, characterized in that, The focal length f2 of the second lens unit and the focal length f3 of the third lens unit satisfy the relational expression: f2 ≤ S1 + 0.45×R1, and f3 ≤ S1 + 0.55×R1.

4. The human body sensor according to claim 2, characterized in that, The relationship between the focal length f1 of the first lens unit and the focal length f2 of the second lens unit further satisfies the relational expression: f2 ≤ f1 + 0.2×f1; the relationship between the focal length f1 of the first lens unit and the focal length f3 of the third lens unit further satisfies the relational expression: f3 ≤ f1 + 0.5×f1.

5. The human body sensor according to claim 1, characterized in that, The vertical distance between the center of the first surface of the lens member and the second surface of the sensing member is less than the radius of curvature R1 of the first surface.

6. The human body sensor according to claim 1, characterized in that, The lens units are constructed as Fresnel lens units, and the light received by the first surface is converged to the sensing member via the Fresnel lens units; The Fresnel lens units are formed with a plurality of concentric annular teeth, and the pitch between adjacent annular teeth is set to 0.2 - 0.6 mm, and the light received by the first surface is converged to the sensing member through the refraction of the annular teeth.

7. The human body sensor according to claim 6, characterized in that, The annular teeth are arranged in a ring around a first central axis; taking the plane where the first central axis is located as a first cross-section, each annular tooth forms a plurality of first generatrices on the first cross-section, and the included angle between the first generatrix of each annular tooth and the first central axis gradually decreases from the center to the edge, wherein the first generatrix is a straight line segment.

8. The human body sensor according to claim 7, characterized in that, The first central axis of the third lens unit is located on the side of the third lens unit close to the first lens unit.

9. The human body sensor according to claim 7, characterized in that, The first central axis of the third lens unit is located on the side of the third lens unit far from the first lens unit.

10. The human body sensor according to claim 7, characterized in that, The first central axis of the third lens unit passes through the center of the third lens unit.

11. The human body sensor according to claim 6, characterized in that, The projected area of the first lens unit projected onto the plane where the second surface is located is set as the first projected area, and the projected area of the second lens unit projected onto the plane where the second surface is located is set as the second projected area; the projected area of the third lens unit projected onto the plane where the second surface is located is set as the third projected area; Wherein, the third projected area is respectively larger than the first projected area and the second projected area.

12. The human body sensor according to claim 1, characterized in that, The lens unit is configured as a convex lens unit, and the light received by the first surface is converged to the sensing element through the convex lens unit.

13. The human body sensor according to claim 12, characterized in that, The sensing element includes two positive temperature sensing units and two negative temperature sensing units. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation; Under the refraction of the convex lens unit, the positive temperature sensing unit and the negative temperature sensing unit form a plurality of detection regions on the side of the convex lens unit away from the sensing element. The light located in any one of the detection regions is converged to the positive temperature sensing unit or the negative temperature sensing unit through the corresponding convex lens unit; The number of the detection regions is greater than or equal to 124.

14. The human body sensor according to claim 13, characterized in that, The ratio of the radius of curvature R1 of the first surface to the arc height H of the first surface satisfies the relational expression: H / R1≥0.

22.

15. A human body sensor according to claim 13, characterized in that, The distance between the centers of two adjacent convex lens units is greater than or equal to 2 mm.

16. A human body sensor according to claim 13, characterized in that, The sensing element forms four of the detection regions under the refraction of any one of the convex lens units; Wherein, the number of the convex lens units is greater than or equal to 31.

17. A human body sensor according to any one of claims 1-16, characterized in that, The lens units are spliced and arranged between each other.

18. A human body sensor according to claim 17, characterized in that, There are multiple second lens units, which are arranged annularly around the outer edge of the first lens unit; There are multiple third lens units, which are arranged annularly around the outer edge of the second lens unit.

19. A human body sensor according to claim 17, characterized in that, The first surface of the lens element is arched, wherein the first lens unit, the second lens unit and the third lens unit are arranged side by side along the bending direction of the arch.

20. A human body sensor according to claim 1, characterized in that, The sensing element is provided with a positive temperature sensing unit and a negative temperature sensing unit on the second surface. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation; The projection of the center of the first lens unit on the second surface is located between the positive temperature sensing unit and the negative temperature sensing unit.

21. A human body sensor according to claim 1, characterized in that, The sensing element is provided with two cross-distributed positive temperature sensing units and two negative temperature sensing units on the second surface. The positive temperature sensing unit outputs a positive voltage in response to infrared radiation, and the negative temperature sensing unit outputs a negative voltage in response to infrared radiation; The projection of the center of the first lens unit on the second surface is surrounded between the positive temperature sensing unit and the negative temperature sensing unit.

22. A human body sensor according to claim 1, characterized in that, The lens element is integrally formed of a white translucent material or a black transparent material.

23. A human body sensor according to any one of claims 1-16, 18-22, characterized in that, Further included: A housing, the lens element is covered on the housing to form an accommodation cavity; A wireless communication unit, electrically connected to the processing unit, and capable of transmitting wireless signals externally; A power supply unit, electrically connected to the sensing element and the wireless communication unit, for providing electric energy; The sensing element, the wireless communication unit, and the power supply unit are accommodated in the accommodation cavity; The housing includes a base, and the base is disposed at an end of the housing away from the lens element for connecting to an external mounting surface.

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