Heart rate detection module and electronic device

Abstract

The application provides a heart rate detection module and an electronic device; wherein the heart rate detection module comprises a light emitting element, a light receiving element and a Fresnel film; the light emitting element and the light receiving element are arranged in optical isolation, the Fresnel film is located on the same side of the light emitting element and the light receiving element, and the light emitting surface of the light emitting element faces the Fresnel film; the Fresnel film has a light absorbing medium therein, and the light absorbing medium is located between the light emitting element and the light receiving element in the direction perpendicular to the Fresnel film. According to the heart rate detection module and the electronic device provided by the application, the crosstalk phenomenon of the detection light emitted by the light emitting element in the Fresnel film can be reduced / attenuated, that is, the light leakage in the Fresnel film can be effectively inhibited to weaken the light noise of the heart rate measurement, and the signal-to-noise ratio of the heart rate detection module can be improved.

Description

Technical Field

[0001] This application relates to the field of heart rate detection equipment technology, and in particular to a heart rate detection module and electronic device. Background Technology

[0002] Photoplethysmography (PPG), also known as photoplethysmography, is a method that uses photoelectric technology to detect changes in blood volume caused by heartbeats under human skin tissue. These changes in blood volume reflect the morphology of the pulse wave and heart rate information. Heart rate detection modules (also known as PPG modules) use the PPG principle to detect the pulse and heart rate of living organisms.

[0003] Generally, a heart rate detection module includes spaced-apart light-emitting elements (such as light-emitting diodes) and photodiodes (PDs). The light-emitting elements emit a detection beam of a specific wavelength, and the PD receives the beam reflected or scattered by human tissue. By analyzing the beam carrying blood information, corresponding physiological parameters such as heart rate and blood oxygen are obtained. In addition, a Fresnel membrane is arranged on the same side of the light-emitting elements and the photodiode, and the Fresnel membrane faces the light-emitting surface of the light-emitting elements. The Fresnel membrane is used to focus the beam to enhance the intensity of the detection beam.

[0004] However, the detection beam emitted by the light-emitting element will cause crosstalk within the Fresnel membrane, causing part of the detection beam to enter the photodetector before reaching the human tissue, thus affecting the detection accuracy of the heart rate detection module. Summary of the Invention

[0005] This application provides a heart rate detection module and electronic device that can solve the problem in traditional technology where the light beam emitted by the light source causes crosstalk in the Fresnel membrane, thus directly passing through the Fresnel membrane to reach the photoelectric detector and affecting the accuracy of the heart rate detection module.

[0006] According to a first aspect of the embodiments of this application, a heart rate detection module is provided, including a light-emitting element, a light-receiving element, and a Fresnel membrane;

[0007] An optical isolation arrangement is provided between the light-emitting element and the light-receiving element, with the Fresnel film located on the same side of the light-emitting element and the light-receiving element, and the light-emitting surface of the light-emitting element facing the Fresnel film;

[0008] The Fresnel membrane contains a light-absorbing medium, which is located between the light-emitting element and the light-receiving element along a direction perpendicular to the Fresnel membrane.

[0009] In this embodiment, a Fresnel film is disposed on the same side of the light-emitting element and the light-receiving element, and the Fresnel film is positioned on one side of the light-emitting surface of the light-emitting element. This allows the light emitted by the light-emitting element to be focused by the Fresnel film, thus enhancing the intensity of the detection beam. A light-absorbing medium is disposed within the Fresnel film, and along a direction perpendicular to the Fresnel film, the light-absorbing medium is located between the light-emitting element and the light-receiving element. In other words, the light-absorbing medium disposed within the Fresnel film is located along the light propagation path of the light-emitting element and the light-receiving element along the Fresnel film. Therefore, the light emitted by the light-emitting element... When the emitted light propagates along the extension direction of the Fresnel membrane, some large-angle light emitted by the light-emitting element can be absorbed or blocked by the light-absorbing medium after being focused by the Fresnel membrane. This cuts off, blocks, isolates, or isolates the light path from the light-emitting element to the light receiver, thus reducing or weakening the crosstalk phenomenon of the detection light emitted by the light-emitting element within the Fresnel membrane. In other words, it can effectively suppress the light leakage within the Fresnel membrane, which weakens the optical noise of heart rate measurement and helps improve the signal-to-noise ratio of the heart rate detection module. In other words, it can improve the accuracy of heart rate detection.

[0010] Furthermore, compared to current methods that place components such as gratings on one side of the Fresnel membrane, the heart rate detection module of this application embodiment does not require additional components, thereby reducing the number of components in the heart rate detection module, simplifying the assembly process, improving the manufacturing efficiency of the heart rate detection module, and saving costs. In addition, compared to the current method of setting the Fresnel membrane into two parts with a toothed structure and a non-toothed structure, aligning the toothed part with the light-emitting surface of the light-emitting element and the non-toothed part with the light-receiving surface of the light-receiving element, the Fresnel membrane of this application embodiment does not require precise assembly to the light-emitting element and the light-receiving element, thereby reducing the assembly precision of the Fresnel membrane and improving the assembly efficiency of the Fresnel membrane of this application embodiment. Furthermore, this application embodiment optimizes the light leakage path, thereby reducing the light emission range of the Fresnel membrane. For example, this application embodiment can reduce the brightness of the Fresnel membrane on the light-receiving surface side of the light-receiving element, thereby improving the aesthetics of the Fresnel membrane.

[0011] In one alternative design, the light-absorbing medium's projection along a direction parallel to the Fresnel membrane covers a region of the Fresnel membrane's thickness.

[0012] In this way, the light-absorbing medium can cut off, block, isolate, or isolate the light propagation path in the thickness direction of the Fresnel film, thereby preventing the detection beam emitted by the light-emitting element from leaking light in the thickness direction of the Fresnel film (i.e., parallel to the extension direction of the Fresnel film). This can effectively suppress the flow of light in the Fresnel film to reduce the optical noise of heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate measurement module.

[0013] In one alternative design, a cavity is formed within the Fresnel membrane, and the light-absorbing medium is located within the cavity.

[0014] By forming a cavity within the Fresnel membrane, the light-absorbing medium can be placed within this cavity, facilitating its connection and adhesion to the membrane. In other words, it allows the light-absorbing medium to adhere easily to the Fresnel membrane, effectively absorbing or blocking light leakage. Furthermore, the cavity ensures the integrity of the Fresnel membrane, simplifying its assembly.

[0015] In one alternative design, there are multiple accommodating cavities, which are spaced apart within the Fresnel membrane.

[0016] By spaced out multiple cavities within the Fresnel membrane, the light leakage from the detection beam emitted by the light-emitting element can be absorbed / blocked by the light-absorbing medium within these cavities, or sequentially absorbed / blocked by the light-absorbing medium. This effectively reduces / attenuates the amount of light leakage within the Fresnel membrane, thus effectively suppressing the light noise in heart rate measurement caused by light leakage and improving the signal-to-noise ratio of the heart rate detection module. Furthermore, the spaced arrangement of multiple cavities within the Fresnel membrane also ensures its structural stability; for example, the area between two adjacent cavities ensures the structural stability of the Fresnel membrane.

[0017] In one alternative design, perforations are formed on the Fresnel membrane, extending to both sides of the Fresnel membrane along its thickness direction; the inner cavity of the perforation is configured as a receiving cavity.

[0018] In this way, forming perforations in the Fresnel membrane and configuring the inner cavity of the perforations as a receiving cavity facilitates the formation of receiving cavities on the Fresnel membrane, improves the formation efficiency of the receiving cavities, and simplifies the processing technology of the receiving cavities. Furthermore, by configuring the inner cavity of the perforations as a receiving cavity, the light-absorbing medium placed within the receiving cavity covers the entire thickness direction of the Fresnel membrane, thereby effectively reducing / attenuating the amount of light leakage within the Fresnel membrane.

[0019] In one alternative design, the Fresnel membrane is provided with a plurality of perforations spaced apart along a first direction; wherein the first direction is the direction from the self-emitting element to the light-receiving element.

[0020] In this way, the light leakage of the detection beam emitted by the light-emitting element within the Fresnel membrane can be absorbed / blocked layer by layer by the light-absorbing medium in the multiple spaced-apart cavities, or it can be absorbed / blocked sequentially by the light-absorbing medium in the multiple spaced-apart cavities. In other words, when the light leakage of the detection beam emitted by the light-emitting element within the Fresnel membrane passes through the first layer of light-absorbing medium, a portion is absorbed, and the amount of light leakage is reduced to a certain extent. When it passes through the next layer of light-absorbing medium, it can be absorbed again, and the amount of light leakage can be reduced layer by layer. This can effectively reduce / attenuate the amount of light leakage within the Fresnel membrane. That is to say, it can effectively suppress the light leakage within the Fresnel membrane from reducing the optical noise of heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate detection module.

[0021] In one alternative design, along the first direction, two adjacent perforations have overlapping areas.

[0022] Two adjacent perforations along the first direction (i.e., the direction from the light-emitting element to the light-receiving element) are configured to have a certain overlap area. In this way, at the overlap area, the light-absorbing medium in the two adjacent perforations can absorb the leakage light in the Fresnel membrane multiple times, thereby effectively reducing / attenuating the amount of leakage light in the Fresnel membrane. In other words, it can effectively suppress the light leakage light in the Fresnel membrane from weakening the optical noise of heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate detection module.

[0023] In one alternative design, two adjacent perforations overlap along a first direction.

[0024] Two adjacent perforations can overlap, allowing the perforation to extend in the direction perpendicular to the first direction. This enables the light-absorbing medium inside the perforation to cover or block a larger light leakage area, effectively reducing or weakening the amount of light leakage in the Fresnel membrane. In addition, this ensures that a single perforation in the direction perpendicular to the first direction does not need to cut or separate the entire Fresnel membrane, thus maintaining the integrity and strength of the Fresnel membrane.

[0025] In one alternative design, the heart rate detection module further includes a light-blocking element; the light-blocking element is positioned between the light-emitting element and the light-receiving element, and the light-blocking element is used to support the Fresnel membrane; the accommodating cavity and the light-blocking element have an overlapping area along a direction perpendicular to the Fresnel membrane.

[0026] This configuration allows for an overlap between the light-absorbing medium and the light-blocking element within the accommodating cavity in the direction perpendicular to the Fresnel membrane. This reduces the gap between the light-absorbing medium and the light-blocking element, effectively preventing light leakage from the Fresnel membrane through the gap between them. In other words, it effectively suppresses light leakage from the Fresnel membrane, thus reducing the optical noise in heart rate measurement and improving the signal-to-noise ratio of the heart rate detection module.

[0027] In one alternative design, the accommodating cavity is perforated, and at least part of the perforation contacts the light-blocking element along the direction parallel to the Fresnel membrane.

[0028] By configuring at least a portion of the perforation to contact a light-blocking element along a direction parallel to the Fresnel membrane, the light-absorbing medium within the perforation can achieve seamless contact with the light-blocking element in the thickness direction of the Fresnel membrane. That is, in the direction parallel to the Fresnel membrane, there are no gaps between the light-absorbing medium and the light-blocking element, thus preventing light leakage from the Fresnel membrane through the gap between the light-absorbing medium and the light-blocking element. Furthermore, since at least a portion of the perforation contacts the light-blocking element, the light-blocking element can support the perforation, thereby ensuring the strength of the Fresnel membrane.

[0029] In one alternative design, there are multiple light receivers, which are spaced apart around the light emitter; multiple accommodating cavities are spaced apart around the light emitter inside the Fresnel membrane, and along the first direction, the light receivers and at least a portion of the accommodating cavities have overlapping areas.

[0030] In other words, when the heart rate detection module has multiple light receivers spaced around the light-emitting element, the number of cavities can also be multiple, and at least part of the cavities are located between the light-emitting element and the light receiver. In this way, at least part of the light leakage occurring within the Fresnel membrane can be absorbed or blocked by the light-absorbing medium within the cavities, thereby reducing / attenuating the amount of light leakage within the Fresnel membrane. That is, it can effectively suppress the light leakage within the Fresnel membrane from reducing the optical noise in heart rate measurement, which is beneficial for improving the signal-to-noise ratio of the heart rate detection module.

[0031] In one alternative design, the light-absorbing medium is ink. This allows the light-absorbing medium to be sprayed using a spray gun that sprays ink onto the Fresnel membrane during manufacturing, simplifying the Fresnel membrane processing and reducing the required processing equipment, thereby improving production efficiency and saving production costs.

[0032] In one alternative design, the ink is adhered to the inner wall of the cavity. This means that only a single layer of light-absorbing medium needs to be applied to the inner wall of the cavity, eliminating the need to fill the entire cavity with it. This saves on the amount of light-absorbing medium used and thus reduces production costs.

[0033] In one alternative design approach, the radial cross-sectional shape of the accommodating cavity includes any one of circular, polygonal, and arc shapes.

[0034] According to a second aspect of the embodiments of this application, an electronic device is provided, including a heart rate detection module provided by any optional design of the embodiments of the first aspect of this application.

[0035] This application embodiment provides a light-absorbing medium within the Fresnel membrane of the heart rate detection module in an electronic device. When the electronic device detects heart rate, the large-angle light formed by crosstalk in the Fresnel membrane caused by the light-emitting element is absorbed / blocked by the light-absorbing medium. This reduces / weakens the crosstalk phenomenon of the detection light emitted by the light-emitting element within the Fresnel membrane, effectively suppressing light leakage within the Fresnel membrane and reducing the optical noise in heart rate measurement. This improves the signal-to-noise ratio of the heart rate detection module, or in other words, enhances the accuracy of the heart rate detection module, thereby improving the accuracy of the electronic device in heart rate detection. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0037] Figure 2 This is an exploded structural diagram of a heart rate detection module provided in an embodiment of this application;

[0038] Figure 3 It is along Figure 2 Sectional view of line AA in the middle;

[0039] Figure 4 This is a cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0040] Figure 5 This is another cross-sectional view of a heart rate detection module provided in one embodiment of this application;

[0041] Figure 6 This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0042] Figure 7 This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0043] Figure 8 This is another exploded structural diagram of a heart rate detection module provided in one embodiment of this application;

[0044] Figure 9 It is along Figure 8 Sectional view of the middle BB line;

[0045] Figure 10 yes Figure 9 A magnified view of a portion of point C in the middle;

[0046] Figure 11This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0047] Figure 12 This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0048] Figure 13 This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application;

[0049] Figure 14 This is a top view of a heart rate detection module provided in an embodiment of this application;

[0050] Figure 15 This is another top view of a heart rate detection module provided in one embodiment of this application;

[0051] Figure 16 This is another exploded structural diagram of a heart rate detection module provided in one embodiment of this application;

[0052] Figure 17 It is along Figure 16 Sectional view of the DD line;

[0053] Figure 18 This is another exploded structural diagram of a heart rate detection module provided in one embodiment of this application;

[0054] Figure 19 It is along Figure 18 Sectional view of the middle EE line;

[0055] Figure 20 This is another top view of a heart rate detection module provided in an embodiment of this application;

[0056] Figure 21 This is another top view of a heart rate detection module provided in an embodiment of this application;

[0057] Figure 22 This is another top view of a heart rate detection module provided in an embodiment of this application;

[0058] Figure 23 This is another top view of a heart rate detection module provided in an embodiment of this application;

[0059] Figure 24 This is another cross-sectional view of a heart rate detection module provided in another embodiment of this application.

[0060] Explanation of reference numerals in the attached figures:

[0061] 10-Electronic devices;

[0062] 100 - Device body; 200 - Wearing structure; 300 - Skin tissue;

[0063] 110 - Heart Rate Detection Module;

[0064] 111-Light emitting element; 112-Light receiving element; 113-Lens; 114-Fresnel film; 115-Light blocking element; 116-Grating; 117-Light absorbing medium; 118-Air gap;

[0065] 1141 - Receptacle; 1142 - Overlapping area. Detailed Implementation

[0066] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0067] Figure 1 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. (Refer to...) Figure 1 As shown, the electronic device 10 provided in this application embodiment can be a wearable electronic device 10, such as a watch, bracelet, or ring, which can be worn on a human body or living organism. Figure 1 The example of a watch is used to illustrate this, and it is understood that this is not intended to limit the specific type of electronic device 10. It should be noted that... Figure 1 The watch shown is illustrated with a round dial as an example. It should be understood that a watch dial can also be rectangular, square, or other polygonal shapes. Figure 1 The circular dial shown is only one specific example and is not a specific limitation on the shape of the dial.

[0068] Understandably, referring to Figure 1 As shown, the electronic device 10 typically includes a main body and a wearing component, with the main body connected to the wearing component to facilitate wearing the electronic device 10. The wearing structure 200 can be... Figure 1 The wristband shown is an example. In some possible examples, the wearing structure 200 could also be a ring buckle, a neckband, etc.

[0069] Currently, wearable electronic devices 10 typically integrate functions such as making phone calls and playing music. Due to their portability and good skin contact, wearable electronic devices 10 can also be used to detect parameters such as heart rate, pulse, and blood oxygenation in living organisms. Specifically, photoplethysmography can be used to detect heart rate, pulse, and other parameters in living organisms.

[0070] Among them, photoplethysmography (PPG), also known as photoplethysmography, is a method that uses photoelectric technology to detect the blood volume changes caused by heartbeats in human skin tissue at a depth of 300 nm. Changes in blood volume typically reflect the morphology of the pulse wave and heart rate information. With the development of modern medicine, disease prevention and early detection have become increasingly important issues. To detect abnormalities in the body as early as possible, a heart rate detection module 110 (also known as a PPG module) is typically used to detect the pulse and heart rate of a living organism using the PPG principle. In other words, the device body 100 of the electronic device 10 provided in this application embodiment includes a heart rate detection module 110.

[0071] Figure 2 This is an exploded structural diagram of a heart rate detection module provided in one embodiment of this application. Figure 3 It is along Figure 2 Cross-sectional view along line AA. (Refer to...) Figure 2 and Figure 3 As shown, a heart rate detection module 110 provided in one embodiment of this application typically includes a light-emitting element 111 and a light-receiving element 112.

[0072] The light-emitting element 111 can be a light-emitting diode (LED). In a specific configuration, the light-emitting element 111 can be placed on a circuit board (not labeled in the figure). The circuit board can be a printed circuit board (PCB) or an integrated circuit board. Multiple circuits are printed or integrated on the circuit board, and the LED can be electrically connected to the circuits on the circuit board.

[0073] It is understood that the electronic device 10 may also include a power supply battery (not shown in the figure), which is connected to the circuit on the circuit board to provide power to various electronic components (such as LEDs and light receivers 112) on the circuit board.

[0074] In practical use, refer to Figure 3 As shown, the light emitted by the light-emitting element 111 shines on the skin tissue 300 of a living organism (such as a human body). After the light is absorbed, reflected and scattered by the blood, the light signal carries blood flow information (such as heart rate, pulse and blood oxygen). It is reflected by the skin tissue 300 to the light receiver 112. The light receiver 112 processes the reflected light to obtain the blood flow information.

[0075] The light receiver 112 can be an optical detector (PD). During use, to ensure the working performance of the light emitter 111 and the light receiver 112, and to prevent sweat from the living body or dust and rain from the external environment from affecting or damaging the light emitter 111, the light receiver 112, and the components of the circuit board, a lens 113 is usually provided on the side of the electronic device 10 facing the living body (i.e., the side closer to the living body's skin when the electronic device 10 is worn). This lens 113 can be a component that directly contacts the skin, and it is usually a transparent structural component. It is understood that the lens 113 can be transparent glass; in some alternative examples, the lens 113 can also be transparent resin.

[0076] In practical use, the detection beam emitted by the light-emitting element 111 shines on the skin tissue 300 of the living body through the lens 113. After absorption, reflection and scattering by the blood, the reflected light returns to the electronic device 10 after passing through the lens 113 and is received by the light receiver 112 in the electronic device 10. The light receiver 112 analyzes the received light signal (for example, transmits / transmits the received light signal to the processor for analysis and processing) to obtain blood flow information.

[0077] Understandably, the detection beam emitted by the light-emitting element 111 typically propagates outward in a divergent pattern. To increase the amount of light emitted by the light-emitting element 111 that illuminates the skin tissue 300, i.e., to increase the amount of light in the effective detection beam, thereby increasing the amount of light that the light receiver 112 can receive, and improving the accuracy of the detection, [further details are needed]. (Refer to...) Figure 2 and Figure 3 As shown, the heart rate detection module 110 typically also includes a Fresnel membrane 114, which is located on the same side of the light-emitting element 111 and the light-receiving element 112, and the light-emitting surface of the light-emitting element 111 faces / is directed toward the Fresnel membrane 114; in other words, the detection beam emitted by the light-emitting element 111 propagates toward the detection of the Fresnel membrane 114.

[0078] As described above, the Fresnel film 114 is located between the light-emitting element 111 or the light-receiving element 112 and the lens 113. (Refer to...) Figure 3 As shown, the detection beam emitted by the light-emitting element 111 passes through the Fresnel membrane 114 and the lens 113 in sequence and irradiates the skin tissue 300 of the living organism. After passing through the tissue of the living organism and other reflections or scattering, the beam passes through the lens 113 and the Fresnel membrane 114 in sequence and is then received by the light receiver 112.

[0079] It should be noted that, in order to reduce, lower, or avoid the detection beam emitted by the light-emitting element 111 directly irradiating the light receiver 112, thereby reducing useless light signals and improving the signal-to-noise ratio of the heart rate detection module 110, refer to Figure 2 and Figure 3 As shown, the light-emitting element 111 and the light-receiving element 112 are usually optically isolated. For example, a light-blocking element 115 or an optical barrier is provided between the light-emitting element 111 and the light-receiving element 112. The light-blocking element 115 can be made of light-absorbing material, such as foam or other black or dark materials.

[0080] The Fresnel membrane 114 is usually mounted on the light-blocking member 115. In other words, the light-blocking member 115 can also provide some support for the Fresnel membrane 114.

[0081] Below, in conjunction with Figure 3 The light propagation path (i.e., optical path) of the detection beam emitted by the light-emitting element 111 in the heart rate detection module 110 provided in this application embodiment is analyzed.

[0082] It is understandable that the light emitted by the light-emitting element 111 usually propagates outward in a divergent manner, that is, in Figure 3 In the middle, one of the propagation paths of the detection beam emitted by the light-emitting element 111 ( Figure 3 In the first optical path a), the light-emitting element 111 can directly illuminate the light receiver 112. It is understood that the detection beam of the first optical path a does not undergo reflection or scattering from the skin tissue 300 of a living organism; that is, the detection beam of the first optical path a does not carry blood flow information (such as pulse, heart rate, and blood oxygenation), and is therefore a useless light signal. As mentioned above, in this embodiment, a light-blocking element 115 is provided between the light-emitting element 111 and the light receiver 112. The first optical path a is cut off by the light-blocking element 115, thereby effectively reducing / weakening the direct illumination of the detection beam emitted by the light-emitting element 111 onto the light receiver 112, reducing the interference of the useless light signal of the first optical path a on the detection beam, and effectively improving the signal-to-noise ratio of the heart rate detection module 110.

[0083] Reference Figure 3 As shown, after the detection beam emitted by the light-emitting element 111 enters the Fresnel membrane 114, due to the focusing effect of the Fresnel membrane 114, some large-angle light may be generated within the Fresnel membrane 114. This large-angle light can propagate along the Fresnel membrane 114 (i.e., along...). Figure 3 The second optical path b) propagates along the Fresnel membrane 114 and is received by the light receiver 112. It can be seen that the detection beam of the second optical path b, which propagates along the Fresnel membrane 114, does not pass through the reflection or scattering of the skin tissue 300 of the living organism, that is, the detection beam of the second optical path b does not carry blood flow information and is a useless light signal.

[0084] Figure 4 This is a cross-sectional view of a heart rate detection module provided in another embodiment of this application. (Refer to...) Figure 4As shown, to reduce light leakage in the Fresnel membrane 114, i.e., to reduce / weaken the interference of the second optical path b on the detection beam, and improve the signal-to-noise ratio of the heart rate detection module 110, an embodiment of this application provides a heart rate detection module 110. This module 110 has a toothed microstructure on the portion of the Fresnel membrane 114 opposite to the light-emitting element 111, while the portion opposite to the light-receiving element 112 is a standard Fresnel membrane 114 (i.e., without the toothed microstructure). A grating 116 (i.e., an optical device formed by a large number of parallel slits of equal width and spacing) is provided on the side of the Fresnel membrane 114 facing / towards the light-receiving element 112 to filter out light leakage from the Fresnel membrane 114. This reduces the interference of light leakage from the Fresnel membrane 114 on the detection beam, effectively improving the signal-to-noise ratio of the heart rate detection module 110, i.e., improving the accuracy of the measurement.

[0085] However, as can be seen from the preceding description, when using the grating 116 to filter the light leakage from the Fresnel membrane 114, the grating 116 and the Fresnel membrane 114 need to be used in conjunction. That is, the grating 116 needs to be accurately attached to the area without the toothed microstructure, which places high precision requirements on the manufacturing and assembly process of the heart rate detection module 110, making assembly difficult. In addition, adding the grating 116 to filter the light leakage from the Fresnel membrane 114 also increases the structural complexity of the heart rate detection module 110.

[0086] In view of this, this application provides a heart rate detection module 110. The main concept is that a light-absorbing medium 117 is disposed within a Fresnel membrane 114, and the light-absorbing medium 117 is disposed between the light-emitting element 111 and the receiving element along a direction perpendicular to the Fresnel membrane 114. In other words, by disposing of the light-absorbing medium 117 within the Fresnel membrane 114, the light leakage path of the Fresnel membrane 114 (i.e., the aforementioned second optical path) is isolated, thereby reducing, weakening, or eliminating light leakage present in the Fresnel membrane 114. This effectively reduces light leakage of the detection beam emitted by the light-emitting element 111 through the Fresnel membrane 114, thereby improving the signal-to-noise ratio of the heart rate detection module 110 and enhancing its detection accuracy. Furthermore, in this embodiment, a light-absorbing medium 117 is provided on the light leakage path of the Fresnel membrane 114 to isolate the light leakage path, thereby eliminating the need for partitioning the Fresnel membrane 114. This simplifies the processing of the Fresnel membrane 114, improves its production efficiency, and consequently increases the production efficiency of the heart rate detection module 110, saving costs. In addition, by providing a light-absorbing medium 117 on the light leakage path of the Fresnel membrane 114 to isolate the light leakage path, it is unnecessary to attach a grating 116 to the surface of the Fresnel membrane 114 facing / towards the light receiver 112. This simplifies the overall structure of the heart rate detection module 110, thereby simplifying the assembly process and accuracy requirements, and saving production costs.

[0087] Figure 5 This is a cross-sectional view of a heart rate detection module provided in another embodiment of this application. (Refer to...) Figure 5 As shown, this application provides a heart rate detection module 110, including a light-emitting element 111, a light-receiving element 112, and a Fresnel membrane 114.

[0088] Specifically, in this embodiment, the light-emitting element 111 can be the aforementioned LED lamp, wherein the detection beam emitted by the LED can be red light, and in some possible examples, the detection beam emitted by the LED can also be green light. In this embodiment, there is no limitation on the specific color of light used as the detection light.

[0089] The light-emitting element 111 and the light-receiving element 112 are optically isolated. For example, see reference... Figure 3 and Figure 5 As described above, a light-blocking component 115 or an optical barrier can be provided between the light-emitting component 111 and the light-receiving component 112, that is, a sheet-like or columnar structural component made of opaque or light-absorbing material, thereby blocking the light. Figure 3 The first optical path in the middle is blocked.

[0090] It is understandable that since the light-emitting element 111 and the light-receiving element 112 are mounted on a circuit board, multiple traces are typically formed on the circuit board through printing or deposition. Therefore, when the light-blocking element 115 or the optical barrier is mounted on the circuit board, there may be a small gap between the light-blocking element 115 or the optical barrier and the surface of the circuit board. To address this, in this embodiment, the light-blocking element 115 or the optical barrier can be made of a material with a certain deformation, such as light-absorbing materials like foam. This minimizes the gap between the light-blocking element 115 or the optical barrier and the circuit board, reducing light leakage in the first optical path, thereby improving the optical isolation between the light-emitting element 111 and the light-receiving element 112 and increasing the signal-to-noise ratio of the heart rate detection module 110.

[0091] The Fresnel membrane 114 is located on the same side of the light-emitting element 111 and the light-receiving element 112, and the light-emitting surface of the light-emitting element 111 faces the Fresnel membrane 114.

[0092] In this embodiment, the Fresnel membrane 114 has a light-absorbing medium 117, which is located between the light-emitting element 111 and the light-receiving element 112 along a direction perpendicular to the Fresnel membrane 114.

[0093] The light-absorbing medium 117 can be made of an opaque material, such as a dark or black material. In some possible examples, the light-absorbing medium 117 can be made of the same material as the light-blocking member 115 or the optical barrier.

[0094] In the embodiments of this application, the light-absorbing medium 117 can be formed in the Fresnel film 114 by means of vapor deposition, deposition or spraying. For example, when making the Fresnel film 114, grooves / pits can be formed on the Fresnel film 114, and then the light-absorbing medium 117 can be formed on the inner wall of the grooves / pits by the above-mentioned means.

[0095] It is understood that in some possible embodiments, the light-absorbing medium 117 may also be filled in the aforementioned groove or pit.

[0096] Below, in conjunction with Figure 3 and Figure 5 As shown, the propagation path of the detection beam emitted by the light-emitting element 111 in this embodiment of the application is analyzed.

[0097] First, the light emitted by the light-emitting element 111 propagates outward in a divergent manner. During its propagation along the aforementioned first optical path a, the first optical path a is isolated by the light-blocking element 115 or an optical barrier, which can reduce, weaken, or eliminate the detection beam propagated by the light-emitting element 111 along the first optical path a. Then, after the detection beam enters the Fresnel membrane 114, most of the light is focused by the Fresnel membrane 114 and passes through the lens 113 to irradiate the skin tissue 300 of the living organism, and is absorbed, reflected, and scattered by the blood. In addition, a small portion of the detection light forms a large-angle light under the reflection of the Fresnel membrane 114 and propagates along the Fresnel membrane 114. When it propagates to the light-absorbing medium 117, this portion of the detection light is absorbed and blocked by the light-absorbing medium 117, and thus will not be received by the light receiver 112. In other words, the light-absorbing medium 117 effectively reduces / attenuates the light leakage of the Fresnel membrane 114, reduces the impact of the light leakage of the Fresnel membrane 114 on the light signal received by the light receiver 112, and thus improves the signal-to-noise ratio of the heart rate detection module 110.

[0098] In this embodiment, a Fresnel film 114 is disposed on the same side of the light-emitting element 111 and the light-receiving element 112, and the Fresnel film 114 is disposed on one side of the light-emitting surface of the light-emitting element 111. This allows the light emitted by the light-emitting element 111 to be focused by the Fresnel film 114, thereby enhancing the intensity of the detection beam. A light-absorbing medium 117 is disposed within the Fresnel film 114, and along a direction perpendicular to the Fresnel film 114, the light-absorbing medium 117 is located between the light-emitting element 111 and the light-receiving element 112. In other words, the light-absorbing medium 117 disposed within the Fresnel film 114 is located between the light-emitting element 111 and the light-receiving element 112 along the light propagation path of the Fresnel film 114. Along the path; thus, when the light emitted by the light-emitting element 111 propagates along the extension direction of the Fresnel membrane 114, that is, when the light emitted by the light-emitting element 111 is focused by the Fresnel membrane 114, some large-angle light can be absorbed or blocked by the light-absorbing medium 117, thereby cutting off, blocking, isolating or isolating the light emitted by the light-emitting element 111 from the Fresnel membrane 114 to the light receiver 112. In other words, it can reduce / weaken the crosstalk phenomenon of the detection light emitted by the light-emitting element 111 in the Fresnel membrane 114, that is, it can effectively suppress the light leakage in the Fresnel membrane 114 to weaken the light noise of heart rate measurement, which is beneficial to improve the signal-to-noise ratio of the heart rate detection module 110. In other words, it can improve the detection accuracy of the heart rate detection module 110.

[0099] Furthermore, compared to setting components such as the grating 116 on one side of the Fresnel membrane 114, the heart rate detection module 110 of this embodiment does not require additional components, thereby reducing the number of components in the heart rate detection module 110, simplifying the assembly process of the heart rate detection module 110, improving the manufacturing efficiency of the heart rate detection module 110, and saving costs. In addition, compared to setting the Fresnel membrane 114 into two parts with a toothed structure and a toothless structure, and aligning the toothed part with the light-emitting surface of the light-emitting element 111 and the toothless part with the light-receiving surface of the light-receiving element 112, the Fresnel membrane 114 of this embodiment does not need to be precisely assembled on the light-emitting element 111 and the light-receiving element 112, thereby reducing the assembly accuracy of the Fresnel membrane 114 and improving the assembly efficiency of the Fresnel membrane 114 of this embodiment. In other words, in this embodiment of the application, a light-absorbing medium 117 is provided on the light leakage path of the Fresnel membrane 114 to isolate the light leakage path, thereby eliminating the need to partition the Fresnel membrane 114. This simplifies the processing technology of the Fresnel membrane 114, improves the production efficiency of the Fresnel membrane 114, and thus improves the production efficiency of the heart rate detection module 110, saving costs.

[0100] Furthermore, in this embodiment, by providing a light-absorbing medium 117 on the light leakage path of the Fresnel membrane 114, the light leakage path is isolated. In this way, it is not necessary to attach a grating 116 to the surface of the Fresnel membrane 114 facing / towards the light receiver 112, thereby simplifying the overall structure of the heart rate detection module 110, which in turn simplifies the assembly process and accuracy requirements of the heart rate detection module 110, and saves production costs.

[0101] In addition, the embodiments of this application have optimized the light leakage path of the Fresnel film 114, thereby reducing the light emission range of the Fresnel film 114. For example, the embodiments of this application can reduce the brightness of the Fresnel film 114 on the light incident surface side of the light receiver 112, thereby improving the aesthetics of the Fresnel film 114.

[0102] Figure 6 This is another cross-sectional view of a heart rate detection module provided in another embodiment of this application. Figure 7 This is another cross-sectional view of a heart rate detection module provided in yet another embodiment of this application. (Refer to...) Figure 6 and Figure 7 As shown in the embodiment of this application, the projection of the light-absorbing medium 117 along the direction parallel to the Fresnel membrane 114 covers the thickness region of the Fresnel membrane 114.

[0103] In other words, in this embodiment, the light-absorbing medium 117 is disposed throughout the thickness region of the Fresnel film 114. For example, in some examples, the Fresnel film 114 can be cut, and the light-absorbing medium 117 can be disposed on both sidewalls in the thickness direction of the cut Fresnel film 114. Of course, in other possible examples, it can also be disposed on the upper and lower surfaces of the Fresnel film 114 (e.g., Figure 7 As shown, grooves are formed by recessing, and light-absorbing medium 117 is filled or sprayed into the grooves.

[0104] Since large-angle light leakage within the Fresnel membrane 114 typically occurs along the thickness direction of the Fresnel membrane 114, the light-absorbing medium 117 can cut off, block, isolate, or shut off the light propagation path along the thickness direction of the Fresnel membrane 114. This prevents the detection beam emitted by the light-emitting element 111 from leaking light along the thickness direction of the Fresnel membrane 114 (i.e., parallel to the extension direction of the Fresnel membrane 114). This effectively suppresses the light flow within the Fresnel membrane 114, which weakens the optical noise in heart rate measurement and helps improve the signal-to-noise ratio of the heart rate measurement module.

[0105] Figure 8 This is an exploded structural diagram of a heart rate detection module provided in another embodiment of this application. Figure 9 It is along Figure 8 Sectional view of the middle BB line. Figure 10 yes Figure 9 A magnified view of point C in the middle. (Refer to...) Figures 8-10 As shown, in an optional example of the embodiments of this application, a receiving cavity 1141 is formed in the Fresnel membrane 114, and the light-absorbing medium 117 is located in the receiving cavity 1141.

[0106] It should be noted that the accommodating cavity 1141 can be formed inside the Fresnel membrane 114, or it can be formed on two surfaces in the thickness direction of the Fresnel membrane 114. The following will describe the two cases of the accommodating cavity 1141 being formed inside the Fresnel membrane and on the Fresnel surface respectively.

[0107] When specifically setting the accommodating cavity 1141, during the molding process of the Fresnel membrane 114, for example, during the injection molding process of the Fresnel membrane 114, after the Fresnel membrane 114 is partially formed, the light-absorbing medium 117 is placed on the already formed part of the Fresnel membrane 114, and then the Fresnel membrane 114 is continued to be injection molded, thereby forming the accommodating cavity 1141 inside the Fresnel membrane 114. In addition, the light-absorbing medium 117 is also formed inside the Fresnel membrane 114.

[0108] In addition, when the accommodating cavity 1141 is formed on the surface of the Fresnel membrane 114, grooves / pits can be etched on the two surfaces of the formed Fresnel membrane 114 along the thickness direction, and then the light-absorbing medium 117 is sprayed or filled into the grooves or pits.

[0109] By forming a receiving cavity 1141 in the Fresnel membrane 114, the light-absorbing medium 117 can be placed within this cavity 1141, facilitating its connection with the Fresnel membrane 114. In other words, it allows the light-absorbing medium 117 to adhere easily within the Fresnel membrane 114, effectively absorbing or blocking light leakage within the membrane. Furthermore, the receiving cavity 1141 ensures the integrity of the Fresnel membrane 114, thus facilitating its assembly.

[0110] It is understood that in the embodiments of this application, after a receiving cavity 1141 is formed in the Fresnel membrane 114 and the light-absorbing medium 117 is placed in the receiving cavity 1141, the light-absorbing medium 117 in the receiving cavity 1141 can block the light leakage of the Fresnel membrane 114, that is, the light leakage that occurs along the aforementioned second optical path. Its blocking effect depends on the material and quality of the light-absorbing medium 117.

[0111] Figure 11 This is another cross-sectional view of a heart rate detection module provided in another embodiment of this application. Figure 12 This is another cross-sectional view of a heart rate detection module provided in yet another embodiment of this application. (Refer to...) Figure 11 and Figure 12 As shown, in one optional design, there are multiple accommodating cavities 1141, which are spaced apart within the Fresnel membrane 114.

[0112] It is understood that in the embodiments of this application, the plurality of accommodating cavities 1141 may be arranged at intervals along the extension direction of the Fresnel membrane 114, for example... Figure 11 The x-direction in the first direction. In other words, the Fresnel membrane 114 is provided with a plurality of perforations at intervals along the first direction; wherein, the first direction is the direction from the self-emitting element 111 to the light receiver 112.

[0113] In this way, the light leakage of the detection beam emitted by the light-emitting element 111 within the Fresnel membrane 114 can be absorbed / blocked layer by layer by the light-absorbing medium 117 in the multiple spaced-apart accommodating cavities 1141, or can be absorbed / blocked sequentially by the light-absorbing medium 117 in the multiple spaced-apart accommodating cavities 1141. In other words, when the light leakage of the detection beam emitted by the light-emitting element 111 within the Fresnel membrane 114 passes through the first layer of light-absorbing medium 117, a portion is absorbed, and the amount of light leakage is reduced to a certain extent. When passing through the next layer of light-absorbing medium 117, it can be absorbed again, and the amount of light leakage can be reduced layer by layer, thereby effectively reducing / attenuating the amount of light leakage within the Fresnel membrane 114. That is to say, it can effectively suppress the light leakage within the Fresnel membrane 114 from weakening the optical noise of heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate detection module 110.

[0114] Of course, in some possible examples, the multiple accommodating cavities 1141 can also be arranged at intervals along the thickness direction of the Fresnel membrane 114. In this way, it can be ensured that the Fresnel membrane 114 still has sufficient strength after the accommodating cavities 1141 are provided.

[0115] Multiple accommodating cavities 1141 are spaced apart within the Fresnel membrane 114. In this way, the light leakage of the detection beam emitted by the light-emitting element 111 within the Fresnel membrane 114 can be absorbed / blocked by the light-absorbing medium 117 within the multiple spaced accommodating cavities 1141, or can be absorbed / blocked sequentially by the light-absorbing medium 117 within the multiple spaced accommodating cavities 1141. This effectively reduces / weakens the amount of light leakage within the Fresnel membrane 114. In other words, it effectively suppresses the light noise of light leakage within the Fresnel membrane 114 that weakens heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate detection module 110.

[0116] Reference Figures 8-10 As shown, in an optional design embodiment of this application, a perforation is formed on the Fresnel membrane 114, and the perforation extends to both sides of the Fresnel membrane 114 along the thickness direction; the inner cavity of the perforation is configured as a receiving cavity 1141.

[0117] In other words, in this embodiment of the application, the accommodating cavity 1141 directly penetrates the two surfaces of the Fresnel membrane 114 along the thickness direction. Thus, after the light-absorbing medium 117 is placed in the accommodating cavity 1141, the light-absorbing medium 117 can block the light leakage of the Fresnel membrane 114 in the thickness direction, thereby blocking / blocking the light leakage of the Fresnel membrane 114.

[0118] It is understood that, in the embodiments of this application, the shape of the perforation can be a circular hole, a rectangular hole, a polygonal hole, a strip hole, or an arc-shaped hole, etc.; wherein, Figure 8 The example shown uses a circular hole; it should be understood that... Figure 8The circular hole shown is merely a specific example and does not limit the specific shape of the perforation. In the actual formation of the perforation, the Fresnel membrane 114 can be integrally formed during injection molding by designing the mold. Alternatively, in some possible examples, the perforation can be obtained after the Fresnel membrane 114 has been formed by secondary processing such as punching or grooving. For instance, when cutting the Fresnel membrane 114, the shape of the cut can be designed to create the perforation.

[0119] In this way, forming perforations in the Fresnel membrane 114 and configuring the inner cavity of the perforations as a receiving cavity 1141 facilitates the formation of the receiving cavity 1141 on the Fresnel membrane 114, improves the formation efficiency of the receiving cavity 1141, and simplifies the processing technology of the receiving cavity 1141. Furthermore, by configuring the inner cavity of the perforations as a receiving cavity 1141, the light-absorbing medium 117 placed within the receiving cavity 1141 covers the entire thickness direction of the Fresnel membrane 114, thereby effectively reducing / attenuating the amount of light leakage within the Fresnel membrane 114.

[0120] Figure 13 This is another cross-sectional view of a heart rate detection module provided in an embodiment of this application. Figure 14 This is a top view of a heart rate detection module provided in an embodiment of this application. (Refer to...) Figure 13 and Figure 14 As shown, in an optional design embodiment of this application, the accommodating cavity 1141 and the light-blocking member 115 have an overlapping area 1142 along the direction perpendicular to the Fresnel membrane 114.

[0121] In other words, in this embodiment of the application, after the Fresnel membrane 114 is installed on the light-blocking member 115, the receiving cavity 1141 on the Fresnel membrane 114 is at least partially located above the light-blocking member 115.

[0122] The following is combined with Figure 13 The light leakage in the Fresnel membrane 114 of the heart rate module provided in this application embodiment is analyzed.

[0123] Reference Figure 13 The second optical path b, when propagating along the Fresnel membrane 114, is partially absorbed or blocked by the light-absorbing medium 117 within the accommodating cavity 1141. This is because the accommodating cavity 1141 and the light-blocking member 115 are in a direction perpendicular to the Fresnel membrane 114 (i.e.,...). Figure 13 There is an overlapping region 1142 in the y-direction, thereby eliminating the overlap between the light-absorbing medium 117 and the light-blocking element 115 in the direction parallel to Fresnel (i.e., Figure 13In other words, in this embodiment, the accommodating cavity 1141 is configured to overlap with the light-blocking member 115 in a direction perpendicular to the Fresnel film 114, thereby eliminating the gap between the light-absorbing medium 117 and the light-blocking member 115 in the second optical path b in a direction parallel to the Fresnel film (i.e., in the x-direction). Figure 13 The light leakage that occurs in the gap (in the x direction) can effectively suppress the light leakage in the Fresnel membrane 114, which weakens the optical noise of heart rate measurement and is beneficial to improving the signal-to-noise ratio of the heart rate detection module 110.

[0124] Figure 15 This is a top view of a heart rate detection module provided in an embodiment of this application. It is understood that, to facilitate the installation of the Fresnel membrane 114, i.e., direct installation on the aforementioned light-blocking member 115 or optical barrier, and to improve the installation efficiency of the Fresnel membrane 114, the perforation typically does not directly cut the Fresnel membrane 114. In other words, along the first direction, the radial dimension of the perforation is smaller than the dimension of the Fresnel membrane 114. Thus, there must be areas on the Fresnel membrane 114 that are not covered by the perforation, that is, areas that are not covered by the light-absorbing medium 117. Therefore, referring to... Figure 15 As shown, in an optional design embodiment of this application, along the first direction, two adjacent perforations have an overlapping area 1142.

[0125] Specifically, the first direction refers to the extension direction of the Fresnel membrane 114 or the propagation direction of the second optical path in the Fresnel membrane 114, for example... Figure 15 The x-direction in the figure refers to the direction of light leakage of the detection beam within the Fresnel membrane 114.

[0126] Two adjacent perforations along the first direction (i.e., the direction from the light-emitting element 111 to the light-receiving element 112) are configured to have a certain overlap area 1142. In this way, at the overlap area 1142, the light-absorbing medium 117 in the two adjacent perforations can absorb the light leakage in the Fresnel membrane 114 multiple times, thereby effectively reducing / attenuating the amount of light leakage in the Fresnel membrane 114. In other words, it can effectively suppress the light leakage in the Fresnel membrane 114 from weakening the optical noise of heart rate measurement, which is beneficial to improving the signal-to-noise ratio of the heart rate detection module 110.

[0127] In one specific example, along the first direction, two adjacent perforations partially overlap. That is, in this embodiment, two adjacent perforations along the first direction are staggered, and the two staggered perforations have overlapping portions. Here, staggering refers to a direction perpendicular to the first direction, for example... Figure 14 In the y-direction, there is a misalignment between the two perforations.

[0128] Two adjacent perforations can overlap, which allows the perforation to extend in the direction perpendicular to the first direction. This allows the light-absorbing medium 117 inside the perforation to cover or block a larger light leakage area. In other words, it can effectively reduce / reduce the amount of light leakage in the Fresnel membrane 114.

[0129] Furthermore, this design ensures that a single perforation perpendicular to the first direction does not require cutting or severing the entire Fresnel membrane 114, thus guaranteeing the integrity and strength of the Fresnel membrane 114. It also facilitates the installation of the Fresnel membrane 114, simplifying the installation process and improving the production efficiency of the heart rate detection module 110.

[0130] Figure 16 This is another exploded structural diagram of a heart rate detection module provided in another embodiment of this application. Figure 17 It is along Figure 16 Cross-sectional view along line DD. (Refer to...) Figure 16 and Figure 17 As shown, the accommodating cavity 1141 is a perforation, and at least part of the perforation contacts the light-blocking member 115 along the direction parallel to the Fresnel membrane 114.

[0131] It is understood that in this embodiment, after the perforation penetrates the Fresnel membrane 114, the edge or opening of the perforation is in contact with the light-blocking member 115. Specifically, it may be in contact with the end of the light-blocking member 115 facing / oriented towards the Fresnel membrane 114. In this way, after the light-absorbing medium 117 is provided inside the perforation, the light-absorbing medium 117 can be seamlessly connected with the light-blocking member 115, thereby reducing, weakening or minimizing light leakage from the Fresnel membrane 114.

[0132] By configuring at least a portion of the perforation to contact the light-blocking member 115 along a direction parallel to the Fresnel membrane 114, the light-absorbing medium 117 located within the perforation can achieve seamless contact with the light-blocking member 115 in the thickness direction of the Fresnel membrane 114. That is, in the direction parallel to the Fresnel membrane 114, there is no gap between the light-absorbing medium 117 and the light-blocking member 115, thereby preventing light leakage within the Fresnel membrane 114 from occurring through the gap between the light-absorbing medium 117 and the light-blocking member 115. Furthermore, since at least a portion of the perforation contacts the light-blocking member 115, the light-blocking member 115 can support the perforation, thus ensuring the strength of the Fresnel membrane 114.

[0133] Figure 18 This is another exploded structural diagram of a heart rate detection module provided in one embodiment of this application. Figure 19 This is another top view of the heart rate detection module provided in one embodiment of this application. Figure 18 and Figure 19As shown, it should be noted that, in order to improve the accuracy of the heart rate detection module 110, multiple light receivers 112 are typically set in the heart rate detection module 110. In specific settings, to ensure that the multiple light receivers 112 receive uniform detection light signals, they are usually arranged at intervals around the light emitter 111, that is, the multiple light receivers 112 can be arranged around the light emitter 111. In this way, after the detection light beam emitted by the light emitter 111 is reflected by the skin tissue 300 of the living organism, each light receiver 112 can receive the reflected detection light signal. By combining the detection light signals received by the multiple light receivers 112, blood flow information is analyzed.

[0134] It should be noted here that... Figure 19 The example shown in the accompanying drawings uses eight optical receivers 112. It is understood that the number of optical receivers 112 can also be other numbers, such as six, nine, or more / fewer. The number of optical receivers 112 shown in the accompanying drawings of this application is for illustrative purposes only and is not a specific limitation on the number of optical receivers 112.

[0135] It is understandable that, in order to avoid light leakage in all directions of the Fresnel membrane 114 and thus affect the various light receivers 112, refer to... Figure 19 As shown in the embodiment of this application, a plurality of accommodating cavities 1141 are provided at intervals around the light-emitting element 111 in the Fresnel membrane 114, and along the first direction, the light-receiving element 112 and at least a portion of the accommodating cavities 1141 have an overlapping area 1142.

[0136] In other words, when the heart rate detection module 110 has multiple light receivers 112 spaced around the light-emitting element 111, the number of accommodating cavities 1141 can also be multiple, and at least a portion of the accommodating cavity 1141 is located between the light-emitting element 111 and the light receiver 112. Thus, at least a portion of the light leakage occurring within the Fresnel membrane 114 can be absorbed or blocked by the light-absorbing medium 117 within the accommodating cavity 1141, thereby reducing / attenuating the amount of light leakage within the Fresnel membrane 114. In other words, it can effectively suppress the light leakage within the Fresnel membrane 114 from weakening the optical noise of heart rate measurement, which is beneficial for improving the signal-to-noise ratio of the heart rate detection module 110.

[0137] It is readily understood that, in this embodiment of the application, when multiple light receivers 112 are spaced around the light emitter 111, the light blocker 115 or optical barrier can be arranged around the light emitter 111 and located between the light emitter 111 and the light receiver 112. In specific configurations, the light blocker 115 or optical barrier can be a circular ring, a rectangular ring, or other ring-shaped structures.

[0138] It should be noted that, as mentioned earlier, to facilitate the installation of the Fresnel membrane 114 and improve the installation efficiency of the heart rate detection module 110, the perforation typically does not sever the Fresnel membrane 114; that is, after a perforation is formed in the Fresnel membrane, the Fresnel membrane 114 remains a complete Fresnel membrane 114. (Refer to...) Figure 19 As shown, multiple perforations can be arranged circumferentially around the light-emitting element 111 on the Fresnel membrane 114. In this way, the portion between two adjacent perforations connects the Fresnel membrane 114 into a whole, which can ensure the integrity and strength of the Fresnel membrane 114.

[0139] Understandably, in practical design, it is necessary to ensure that the light-absorbing medium 117 filling or attached to the perforations can absorb or block as much light leakage as possible from the Fresnel membrane 114. This requires the perforation diameter to be as large as possible. Figure 19 With the center of the light-emitting element 111 as the corner point, the first included angle θ1 extending from both sides of the perforation needs to be as large as possible.

[0140] It is understandable that when the first included angle θ1 becomes large enough, adjacent perforations may become interconnected, causing the Fresnel membrane 114 to be divided into two parts. This is detrimental to the installation of the Fresnel membrane 114 and will also affect its strength. Therefore, referring to... Figure 20 As shown, there is a second included angle θ2 between two adjacent perforations. It can be seen that the size of the second included angle θ2 determines the strength of the Fresnel membrane 114.

[0141] It should be noted that the numerical values ​​and ranges involved in the embodiments of this application are approximate values. Due to the influence of the manufacturing process, there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0142] The following is combined with Figure 19 An analysis of the optical path within the Fresnel membrane 114 reveals that the detection beam emitted by the light-emitting element 111, after entering the Fresnel membrane 114, may generate some large-angle light due to the focusing effect of the Fresnel membrane 114. This large-angle light propagates along the Fresnel membrane 114, and a portion of it reaches the perforation, where it is absorbed or blocked by the light-absorbing medium 117 disposed within the perforation (e.g., ...). Figure 19 The third optical path (c) in the middle; another part of the light passes through the gap between two adjacent perforations (e.g., Figure 19 The fourth optical path d). It can be seen that in the embodiments of this application, the reduction in light leakage of the Fresnel membrane 114 is θ1 / (θ1+θ2). Of course, in some possible determination methods, it can also be n*θ1 / 360°, where n is the number of perforations.

[0143] Figure 20This is another top view of the heart rate detection module provided in one embodiment of this application.

[0144] It should be noted that, referring to Figure 20 As shown, in some optional examples of embodiments of this application, the heart rate detection module 110 may also include multiple light-emitting elements 111, wherein each of the multiple light-emitting elements 111 can emit a detection beam, and the multiple light-emitting elements 111 have an equivalent center / equivalent axis, and the distances from the multiple light-emitting elements 111 to the equivalent center / equivalent axis are equal, close, or approximately. This ensures that the light emitted by the multiple light-emitting elements 111 is uniformly dispersed outward around the equivalent center / equivalent axis. Of course, Figure 20 The number of light-emitting elements 111 shown is merely an illustrative example and not a specific limitation on the number of light-emitting elements 111.

[0145] Figure 21 This is another top view of a heart rate detection module provided in one embodiment of this application. Figure 22 This is another top view of a heart rate detection module provided in one embodiment of this application. (Refer to...) Figure 21 and Figure 22 As shown in the embodiments of this application, the perforations can also be arc-shaped holes, V-shaped holes, or other shapes. The perforations are arranged in multiple layers / rounds along a direction parallel to the Fresnel membrane 114. Figure 21 and Figure 22 It can be seen that along the first direction (e.g., the direction from the self-emitting element 111 to the light receiver 112), adjacent perforations are staggered, and there is partial overlap between adjacent perforations. From Figure 20 As can be seen from the data, the two parameters affecting the structural strength and light leakage of the Fresnel membrane 114 are the included angle θ3 of the overlapping area 1142 between two adjacent perforations and the distance L between two adjacent perforations.

[0146] The specific analysis is as follows: If θ3 = 0, it means that the inner and outer light-absorbing arc holes are exactly aligned head-to-head, without overlap or misalignment; if θ3 > 0, it means that there is an overlapping region 1142 with an angle of θ3 between the inner and outer light-absorbing arc holes; if θ3 < 0, then there is a misalignment of θ between the inner and outer light-absorbing arc holes. Taking the number of misalignments of the inner and outer arc holes as n, the light leakage is reduced to n*θ3 / 360° of the original value. Therefore, when θ3 is greater than or equal to 0, the perforation can completely block the light leakage of the Fresnel membrane 114.

[0147] In addition, if L is too small, the Fresnel membrane 114 in the corresponding area of ​​the light-emitting element 111 is prone to deformation, which is not conducive to the assembly of the Fresnel membrane 114. In practical applications, θ3 and L can be adjusted according to actual needs.

[0148] It should be noted that in some possible examples, perforations can also be set in multiple rows, such as 3, 4 or more rows. The specific setup method can be found in [reference needed]. Figure 21 and Figure 22 Configure it using the settings provided.

[0149] The following is combined with Figure 21 The light leakage in the Fresnel membrane 114, i.e., the optical path, was analyzed. It can be seen that when there is an overlapping area 1142 between the two rows of perforations, the light leakage in the Fresnel membrane 114 is completely blocked, which improves the signal-to-noise ratio of the heart rate detection module 110.

[0150] It should be noted that, in this embodiment, perforations are formed on the Fresnel membrane 114, and the inner cavity of the perforation is configured as a receiving cavity 1141. Thus, after the Fresnel membrane 114 is processed, only the structural shape of the cut Fresnel membrane 114 needs to be modified. For example, the aforementioned perforation shape (e.g., a circular hole, an arc-shaped hole, a polygonal hole, or a V-shaped hole) can be added to the original cutting shape, and then the Fresnel membrane 114 can be cut. Therefore, no new processing technology is required when processing the Fresnel membrane 114, saving processing time and improving manufacturing efficiency.

[0151] Figure 23 This is another top view of a heart rate detection module provided in one embodiment of this application. Figure 24 This is another cross-sectional view of a heart rate detection module provided in another embodiment of this application.

[0152] Reference Figure 23 and Figure 24 As shown, in other examples, the accommodating cavity 1141 may also be an annular groove surrounding the light-emitting element 111. The annular groove may also be two concentric rings arranged along a first direction. The two concentric annular grooves may be formed from two separate surfaces of the Fresnel membrane 114, and the two annular grooves have an overlapping region 1142 along the first direction. In other words, the depth of the annular groove is greater than or equal to half the thickness of the Fresnel membrane 114.

[0153] In some alternative examples, the light-absorbing medium 117 can be ink for easier configuration. Specifically, the ink can be a light-absorbing ink. This allows the light-absorbing medium 117 to be sprayed using a spray gun that sprays ink onto the Fresnel membrane 114 during manufacturing, simplifying the processing of the Fresnel membrane 114, reducing the required processing equipment, improving production efficiency, and saving production costs.

[0154] In addition, the ink adheres to the inner wall of the accommodating cavity 1141. In this way, only a layer of light-absorbing medium 117 needs to be adhered to the inner wall of the accommodating cavity 1141, instead of filling the entire accommodating cavity 1141 with light-absorbing medium 117, which can save the amount of light-absorbing medium 117 used, thereby saving production costs.

[0155] In actual manufacturing, ink can be sprayed onto the inner wall of the perforations during the ink spraying process of the Fresnel membrane 114, so that the light-absorbing ink adheres to the inner sidewall of the perforations, thereby isolating the light leakage inside the Fresnel membrane 114. In this way, no additional processing steps are required, which can save production costs.

[0156] Additionally, it should be noted that after the detection beam emitted by the light-emitting element 111 passes through the Fresnel membrane 114 and enters the lens 113, crosstalk occurs in the lens 113, meaning light leakage also occurs. Some of this leaked light is received by the light receiver 112. This portion of light does not pass through the skin tissue 300 of the living organism and is therefore useless light. In some optional examples of the embodiments of this application, refer to... Figure 3 As shown, a certain gap is reserved between the Fresnel film 114 and the lens 113 to form an air gap 118. By changing the optical value, the corresponding light is refracted, thereby reducing optical crosstalk in the lens 113. In the air gap 118, a light-blocking element 115 or an optical barrier is also provided in front of the light-emitting element 111 and the light-receiving element 112.

[0157] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0158] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Claims

1. A heart rate detection module, characterized in that, Includes light-emitting components, light-receiving components, and Fresnel films; The light-emitting element and the light-receiving element are optically isolated from each other, the Fresnel film is located on the same side of the light-emitting element and the light-receiving element, and the light-emitting surface of the light-emitting element faces the Fresnel film; The Fresnel membrane contains a light-absorbing medium, which is located between the light-emitting element and the light-receiving element along a direction perpendicular to the Fresnel membrane. The light-absorbing medium, when projected along a direction parallel to the Fresnel film, covers the thickness region of the Fresnel film; The Fresnel membrane is provided with a plurality of perforations spaced apart along a first direction, the perforations extending to both sides of the Fresnel membrane along the thickness direction, and the light-absorbing medium is located inside the cavity of the perforations; Along the first direction, two adjacent perforated portions overlap.

2. The heart rate detection module according to claim 1, characterized in that, The heart rate detection module also includes a light-blocking component; The light-blocking member is disposed between the light-emitting member and the light-receiving member, and the light-blocking member is used to support the Fresnel membrane; Along a direction perpendicular to the Fresnel membrane, the perforation and the light-blocking element have an overlapping area.

3. The heart rate detection module according to claim 1, characterized in that, Along a direction parallel to the Fresnel membrane, at least a portion of the perforation contacts the light-blocking element of the heart rate detection module.

4. The heart rate detection module according to any one of claims 2-3, characterized in that, The number of light receivers is multiple, and the multiple light receivers are arranged at intervals around the light emitter; The Fresnel membrane has a plurality of perforations spaced around the light-emitting element, and along the first direction, the light-receiving element has an overlapping area with at least a portion of the perforations.

5. The heart rate detection module according to any one of claims 2-3, characterized in that, The light-absorbing medium is ink.

6. The heart rate detection module according to claim 5, characterized in that, The ink adheres to the inner wall of the perforation.

7. The heart rate detection module according to any one of claims 2-3 and 6, characterized in that, The radial cross-sectional shape of the perforation includes any one of the following: circular, polygonal, and arc-shaped.

8. An electronic device, characterized in that, Includes the heart rate detection module as described in any one of claims 1-7.

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