Detection and measurement devices

Abstract

The present invention provides a detection device and a measuring device capable of miniaturizing the device structure. The detection device of the present invention comprises: a first light emitting unit that emits a first light having a green wavelength band; a second light emitting unit that emits a second light having a wavelength band longer than the green wavelength band; a first light receiving unit that receives the first light emitted from the first light emitting unit and emitted from a living organism; and a second light receiving unit that receives the second light emitted from the second light emitting unit and emitted from the living organism. When the direction in which the first and second light emitting units are arranged is defined as a first direction and a direction intersecting the first direction is defined as a second direction, in the second direction, at least a portion of the first light receiving unit is positioned closer to the first light emitting unit than the second light receiving unit, and the area of ​​the first light receiving unit is smaller than the area of ​​the second light receiving unit.

Description

Technical Field

[0001] The present invention relates to a detection device and a measuring device. Background Art

[0002] Various measurement technologies for non-invasively measuring biological information such as pulse have been proposed. For example, Patent Document 1 below discloses a detection device comprising a light-emitting unit that emits light toward a living organism and a light-receiving unit that receives light emitted from the light-emitting unit and then reflected by the living organism. The device improves light utilization efficiency of the light-emitting unit and takes measures to counteract stray light in the light-receiving unit by providing a light-shielding member between the light-emitting unit and the light-receiving unit.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2018-061675

[0004] In the above-mentioned detection device, the inclined surface formed on the light shielding member reflects light, thereby improving the light utilization efficiency of the light emitting unit. However, since space is required to provide the inclined surface on the light shielding member, there is a problem that the device structure cannot be miniaturized. Summary of the Invention

[0005] According to one embodiment of the present invention, a detection device is provided, comprising: a first light-emitting portion that emits a first light having a green wavelength band; a second light-emitting portion that emits a second light having a wavelength band longer than the green wavelength band; a first light-receiving portion that receives the first light emitted from the first light-emitting portion and emitted from a biological body; and a second light-receiving portion that receives the second light emitted from the second light-emitting portion and emitted from the biological body, wherein, when the direction in which the first light-emitting portion and the second light-emitting portion are arranged is a first direction and a direction intersecting the first direction is a second direction, in the second direction, at least a portion of the first light-receiving portion is arranged closer to the first light-emitting portion than the second light-receiving portion, and the area of ​​the first light-receiving portion is smaller than the area of ​​the second light-receiving portion.

[0006] According to one aspect of the present invention, there is provided a measurement device comprising: the detection device of the above aspect; and an information analysis unit for determining biological information based on a detection signal indicating a detection result of the detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a side view of the measuring device according to the first embodiment.

[0008] Figure 2 This is a structural diagram focusing on the functions of the measuring device.

[0009] Figure 3 It is a top view of the detection device.

[0010] Figure 4 is based on Figure 3 Cross-sectional view of the IV-IV line arrow.

[0011] Figure 5 is a graph showing the transmission spectrum of skin.

[0012] Figure 6 It is a graph showing the relationship between the red light-emitting portion and the light-receiving portion.

[0013] Figure 7 It is a diagram for explaining the operation of the detection device.

[0014] Figure 8 It is a cross-sectional view of the detection device according to the second embodiment.

[0015] Figure 9 It is a cross-sectional view of a detection device according to a third embodiment.

[0016] Label Description

[0017] 3, 103, 203: Detection device; 5: Control device (information analysis unit); 41: Light shielding wall; 50: First light-emitting unit; 51, 151, 251: First light-receiving unit; 61: Second light-receiving unit; 60: Second light-emitting unit; 70: Third light-receiving unit; 100: Measuring device; 120: Light-receiving element (first sensor unit); 121: Angle limiting filter (first angle limiting filter); 122: Bandpass filter; 141, 241: First light shielding wall; 142, 242: First 2 light-shielding walls; 1512, 2512: second light-receiving portion; 220: light-receiving element (second sensor portion); 221: angle-limiting filter (second angle-limiting filter); 243: third light-shielding wall; 244: fourth light-shielding wall; 1511, 2511: first light-receiving portion; 2513: third light-receiving portion; 2514: fourth light-receiving portion; LG: green light (first light); LR: red light (second light); LI: near-infrared light (third light); M: measuring part (biological body). DETAILED DESCRIPTION

[0018] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. In the following drawings, the scales and angles of the components are different from the actual ones in order to make the components recognizable.

[0019] (First embodiment)

[0020] Figure 1 It is a side view of the measuring device 100 according to the first embodiment. Figure 1The measuring device 100 of the present embodiment shown is a biological measuring instrument that non-invasively measures biological information of a subject (e.g., a human) as an example of a living body, and is worn on a portion M of the subject's body that serves as a measurement target (hereinafter referred to as the "measurement portion"). The measuring device 100 of the present embodiment is a wristwatch-type portable device having a housing 1 and a strap 2. The measuring device 100 can be worn on the subject's wrist by wrapping the belt-like strap 2 around the wrist, which is an example of the measurement portion (living body) M. In the present embodiment, the subject's pulse (e.g., pulse interval PPI) and oxygen saturation (SpO2) are exemplified as biological information. The pulse refers to the temporal change in the volume within the blood vessels that is linked to the pulsation of the heart. The oxygen saturation refers to the proportion (%) of hemoglobin in the subject's blood that is bound to oxygen, and is an indicator used to evaluate the subject's respiratory function.

[0021] Figure 2 This is a structural diagram focusing on the functions of the measuring device 100. Figure 2 As shown in FIG. 1 , the measuring device 100 of this embodiment includes a control device 5, a storage device 6, a display device 4, and a detection device 3. The control device 5 and the storage device 6 are provided inside the housing 1. Figure 1 As shown, the display device 4 is provided on the surface of the housing 1 on the side opposite to the measurement site M, and displays various images including measurement results under the control of the control device 5. The display device 4 is, for example, a liquid crystal display panel.

[0022] The detection device 3 is an optical sensor module that generates a detection signal S corresponding to the state of the measurement site M. Figure 1 As shown, the detection device 3 is provided on a surface (hereinafter referred to as a detection surface) 16 of the housing 1 that is opposite to the measurement site M. The detection surface 16 is a surface that contacts the measurement site M. Figure 2 As shown, the detection device 3 of this embodiment includes a light-emitting unit 11, a light-receiving unit 12, a drive circuit 13, and an output circuit 14. Alternatively, one or both of the drive circuit 13 and the output circuit 14 may be provided as external circuits to the detection device 3. In other words, the drive circuit 13 and the output circuit 14 may be omitted from the detection device 3.

[0023] Figure 3 It is a top view of the detection device 3. Figure 4 is based on Figure 3 The cross-sectional view of the IV-IV line arrow in FIG. Figure 3 as well as Figure 4 As shown, the detection device 3 of this embodiment includes a housing 40, a light shielding wall 41 and a sealing layer 42 in addition to the light emitting unit 11 and the light receiving unit 12. Figure 3 as well as Figure 4 In the figure, the driving circuit 13 and the output circuit 14 are omitted.

[0024] The following describes the structure of the detection device 3 using an XYZ coordinate system. The X-axis corresponds to an axis along the long side (one side) of the rectangular housing 40, the Y-axis corresponds to an axis perpendicular to the X-axis and along the short side (the other side) of the housing 40, and the Z-axis corresponds to an axis perpendicular to the X-axis and the Y-axis and along the normal to the detection surface 16 in contact with the measurement site M.

[0025] like Figure 3 and Figure 4 As shown, the housing 40 is a component that houses the various elements (light-emitting unit 11 and light-receiving unit 12) that make up the detection device 3. The housing 40 has a box-like shape and includes a rectangular, flat bottom portion 40a and rectangular, frame-shaped side panels 40b that protrude from the periphery of the bottom portion 40a toward the +Z side. The housing 40 is formed, for example, from aluminum. The inner circumferential surface 40b1 of the side panel 40b is colored black to provide light-shielding properties. This suppresses reflections from the inner circumferential surface 40b1 of the side panel 40b.

[0026] The material and manufacturing method of the housing 40 are arbitrary. For example, the housing 40 may be formed by injection molding of a resin material. In addition, it is also preferable to form the housing 40 integrally with the housing portion 1.

[0027] The light-emitting unit 11 and the light-receiving unit 12 are arranged on the bottom portion 40a of the housing 40 in a state of being mounted on a wiring substrate (not shown). The light-shielding wall 41 is arranged between the light-emitting unit 11 and the light-receiving unit 12 in the direction along the X-axis. The light-shielding wall 41 is a flat-plate-shaped component that protrudes from the bottom portion 40a to the +Z side and extends in the Y-axis direction, and separates the storage space in the housing 40 into two in the X-axis direction. That is, the light-shielding wall 41 is a component that separates the space for storing the light-emitting unit 11 and the light-receiving unit 12 in the direction along the X-axis. The light-shielding wall 41 is a light-shielding component that is used to shield light emitted from the light-emitting unit 11 from directly entering the light-receiving unit 12. The light-shielding wall 41 of this embodiment is a flat-plate-shaped component, so that the device structure is not enlarged in the direction along the X-axis.

[0028] In this embodiment, the light shielding wall 41 is provided along the X-axis between the light emitting unit 11 and the light receiving unit 12, including the first light emitting unit 50 and the second light emitting unit 60. The light shielding wall 41 can also be said to be a component that blocks a portion of the green light LG, the red light LR, and the near-infrared light LI.

[0029] The sealing layer 42 is a translucent resin material that fills the gap between the light-emitting unit 11 and the light-receiving unit 12 housed in the housing 40 and the side plate 40b. The sealing layer 42 seals (moldes) the light-emitting unit 11 and the light-receiving unit 12 within the housing 40. The surface of the sealing layer 42 functions as the detection surface 16.

[0030] Alternatively, the upper surface of the side plate portion 40 b of the housing 40 may be covered with a translucent substrate instead of the sealing structure with the sealing layer 42 . In this case, the upper surface of the translucent substrate functions as the detection surface 16 .

[0031] The light emitting unit 11 includes a first light emitting unit 50, a second light emitting unit 60, and a third light emitting unit 70. The first light emitting unit 50, the second light emitting unit 60, and the third light emitting unit 70 are light sources that emit light of different wavelengths toward the measurement site M, respectively.

[0032] The first light emitting unit 50 emits green light (first light) LG having a green wavelength band of 520 nm to 550 nm toward the measurement site M. The green light LG of the present embodiment is light having a peak wavelength of 520 nm, for example.

[0033] The second light emitting unit 60 emits red light (second light) LR having a red wavelength range of, for example, 600 nm to 800 nm toward the measurement site M. The red light LR of the present embodiment is light having a peak wavelength of, for example, 660 nm.

[0034] The third light emitting unit 70 emits near-infrared light (third light) LI having a near-infrared wavelength range of, for example, 800 nm to 1300 nm toward the measurement site M. The near-infrared light LI of the present embodiment is light having a peak wavelength of, for example, 905 nm.

[0035] As the light-emitting elements constituting the first light-emitting unit 50, the second light-emitting unit 60, and the third light-emitting unit 70, for example, bare chip or bullet-shaped LEDs (Light Emitting Diodes) are preferably used. Furthermore, the wavelength of light emitted by each light-emitting unit is not limited to the aforementioned numerical range. Hereinafter, when the first light-emitting unit 50, the second light-emitting unit 60, and the third light-emitting unit 70 are not specifically distinguished, they are collectively referred to as the light-emitting units 50, 60, and 70.

[0036] The light emitting unit 11 is provided in the housing 40 such that the light emitting surface of each light emitting portion 50, 60, 70 is parallel to the XY plane. That is, each light emitting portion 50, 60, 70 emits light toward the +Z side.

[0037] Each light emitting unit 50, 60, 70 is respectively Figure 2The driving circuit 13 shown emits light when supplied with a driving current. In this embodiment, the driving circuit 13 causes each light-emitting unit 50, 60, and 70 to emit light independently and temporally. Hereinafter, causing each light-emitting unit 50, 60, and 70 to emit light independently and temporally will be referred to as the light-emitting units 50, 60, and 70 periodically emitting light in a time-division manner.

[0038] Light emitted from each of the light-emitting units 50, 60, and 70 enters the measurement site M, propagates through the interior of the measurement site M while repeatedly reflecting and scattering, and then exits toward the housing 1 and reaches the light-receiving unit 12. Specifically, the detection device 3 of this embodiment is a reflective optical sensor in which the light-emitting unit 11 and the light-receiving unit 12 are located on one side relative to the measurement site M.

[0039] like Figure 3 As shown, the light-emitting sections 50, 60, and 70 are arranged in a spaced relationship along the Y-axis (first direction). Specifically, the second light-emitting section 60 is located on the +Y side of the first light-emitting section 50, and the third light-emitting section 70 is located on the -Y side of the first light-emitting section 50. In other words, the first light-emitting section 50 is located between the second light-emitting section 60 and the third light-emitting section 70 along the Y-axis. Alternatively, the first light-emitting section 50 can be said to be positioned between the second light-emitting section 60 and the third light-emitting section 70.

[0040] Conventionally, there are known detection devices that can obtain both pulse interval (PPI) and oxygen saturation (SpO2) as biological information of a measured subject. Furthermore, there is a desire for further miniaturization of measurement devices including such detection devices. Against this backdrop, the present inventors have conducted in-depth research on a compact detection device capable of obtaining both pulse interval and oxygen saturation.

[0041] First, the inventors focused on the fact that the transmittance of skin differs for each wavelength band of light.

[0042] Figure 5 is a graph showing the transmission spectrum of skin. Figure 5 In the graph, the horizontal axis represents the wavelength of light, and the vertical axis represents the transmittance (unit: %). Figure 5 As an example, the transmission area when the skin thickness is 0.43 mm is shown.

[0043] like Figure 5 As shown, the transmittance of the green light LG band (for example, 520nm) when incident on the skin is about 30%, the transmittance of the red light LR band (for example, 660nm) when incident on the skin is about 50% to 60%, and the transmittance of the near-infrared light LI band (for example, 905nm) when incident on the skin is about 60%.

[0044] Figure 5 The graph shown in FIG. 1 shows that the distance that can be propagated in the body varies depending on the wavelength of light. Figure 5 As can be seen from the curve, green light LG can only propagate a shorter distance in the body than red light LR or near infrared light LI. In other words, red light LR and near infrared light LI can propagate farther in the body than green light LG. Figure 5 In the example, the case where the skin thickness is 0.43 mm is cited, but when the skin thickness is different, the red light LR and the near-infrared light LI can propagate farther in the biological body than the green light LG.

[0045] The present inventors have obtained the following insights: Figure 5 As shown in the graph, green light LG is more easily attenuated when passing through a living body than red light LR and near-infrared light LI.

[0046] In addition, the present inventors simulated the incident state of green light LG passing through the body of a living being to the light receiving part. In this simulation, a light receiving part of a conventional size was used. Figure 3 The lower part of shows the results of this simulation.

[0047] like Figure 3 As shown, it can be confirmed that: in the light receiving portion 9 of normal size, the side close to the first light emitting portion 50 ( Figure 3 The light receiving surface 9a of the lower left side of the luminous element 50 forms a light incident area 7 where the green light LG is concentratedly incident. However, the green light LG is hardly incident on the side away from the first light emitting portion 50 ( Figure 3 This is because the green light LG is sufficiently attenuated in the living body before entering the light receiving surface 9a away from the first light emitting portion 50.

[0048] The present inventors have found that the device structure can be reduced in size by arranging a green light receiving section having a size corresponding to the light incident area where green light LG that has passed through the biological body is concentrated, near the light emitting section.

[0049] The inventors also noted that the noise components contained in red and near-infrared light that propagate through a living body and enter the light-receiving unit vary depending on the distance from the light-emitting unit to the light-receiving unit. While the following explanation uses red light as an example, the same principle applies to near-infrared light.

[0050] Figure 6 This is a graph showing the relationship between the distance from the red light emitting unit to the light receiving unit, the noise component of the red light, and the current consumption of the red light emitting unit. Figure 6In the figure, the horizontal axis represents the distance from the red light emitting unit to the light receiving unit, the vertical axis on the left represents the noise component of the red light LR, and the vertical axis on the right represents the current consumption of the light emitting unit.

[0051] like Figure 6 As shown, the closer the distance between the light receiving unit and the light emitting unit, the greater the noise component of the red light LR received by the light receiving unit. In other words, the further the light receiving unit is from the light emitting unit, the lower the noise component of the red light LR is, thereby improving the detection accuracy of the red light LR. This is because the red light LR that is reflected by the surface of the living body and does not pass through the blood is incident on the light receiving unit when it is located close to the light emitting unit. This red light LR that does not pass through the blood becomes a noise component in the light receiving unit when determining the blood oxygen concentration.

[0052] Therefore, by placing the light receiving unit away from the red light emitting unit, the noise component contained in the red light LR can be reduced, thereby improving the detection accuracy of the red light LR. On the other hand, when the light receiving unit is placed away from the red light emitting unit, the distance propagated within the organism increases, necessitating an increase in the current supplied to the red light emitting unit to improve the brightness of the red light. In this case, since the current consumption of the red light emitting unit increases, it is preferable to consider the balance between noise components and current consumption when determining the distance between the red light emitting unit and the light receiving unit.

[0053] Regarding near-infrared light LI, similar to red light LR, the accuracy of detecting near-infrared light LI can be improved by placing the near-infrared light emitting unit and the light receiving unit away from each other. The distance between the near-infrared light emitting unit and the light receiving unit is preferably determined by considering the balance between noise components and current consumption.

[0054] The present inventors have found that the detection accuracy of the red light LR or the near-infrared light LI is improved by arranging a light receiving unit that receives the red light LR or the near-infrared light LI away from the light emitting unit.

[0055] Based on the above findings, the present inventors have completed the detection device 3 and the measurement device 100 of the present embodiment. Hereinafter, the configurations of the detection device 3 and the measurement device 100 of the present embodiment will be described in detail.

[0056] The light receiving unit 12 receives light emitted from the measurement site M by the light emitting unit 11. The light receiving unit 12 of this embodiment includes a first light receiving unit 51 and a second light receiving unit 61. The light receiving units 51 and 61 generate detection signals corresponding to the intensity of the received light. Hereinafter, the light receiving units 51 and 61 will be collectively referred to as "light receiving units 51 and 61" unless otherwise specified.

[0057] The light receiving unit 12 is provided in the housing 40 such that the light receiving surfaces of the light receiving portions 51 and 61 are parallel to the XY plane. That is, the light receiving portions 51 and 61 receive light incident from the Z direction.

[0058] like Figure 3 As shown, the light receiving portions 51 and 61 are spaced apart from each other and arranged in the direction (second direction) along the X-axis that intersects (is perpendicular to) the Y-axis. Specifically, the first light receiving portion 51 is located on the +X side of the light emitting unit 11, and the second light receiving portion 61 is located on the +X side of the first light receiving portion 51. The second light receiving portion 61 is arranged on the side opposite to the light emitting unit 11 across the first light receiving portion 51. In the case of this embodiment, the second light receiving portion 61 is provided at a position farther away from the first light emitting portion 50 than the first light receiving portion 51. Specifically, the first light receiving portion 51 is located closer to the first light emitting portion 50 than the second light receiving portion 61 in the direction along the X-axis.

[0059] Here, the distance from the first light-emitting section 50 to the first light-receiving section 51 is denoted as D1, the distance from the second light-emitting section 60 to the second light-receiving section 61 is denoted as D2, and the distance from the third light-emitting section 70 to the second light-receiving section 61 is denoted as D3. Distance D1 corresponds to the distance between the centers of the first light-emitting section 50 and the first light-receiving section 51 when viewed from above in the Z-axis direction. Distance D2 corresponds to the distance between the centers of the second light-emitting section 60 and the second light-receiving section 61 when viewed from above in the Z-axis direction. Distance D3 corresponds to the distance between the centers of the third light-emitting section 70 and the second light-receiving section 61 when viewed from above in the Z-axis direction.

[0060] In the detection device 3 of this embodiment, the distance D1 from the first light-emitting section 50 to the first light-receiving section 51 is shorter than the distance D2 from the second light-emitting section 60 to the second light-receiving section 61. Furthermore, the distance D1 from the first light-emitting section 50 to the first light-receiving section 51 is shorter than the distance D3 from the third light-emitting section 70 to the second light-receiving section 61. Furthermore, the distance D2 and the distance D3 are equal.

[0061] Thus, in the detection device 3 of this embodiment, the first light receiving unit 51 for receiving the green light LG is arranged closest to the first light emitting unit 50 that emits the green light LG. Thus, the first light receiving unit 51 can receive the green light LG that is transmitted through the body without being attenuated.

[0062] In the detection device 3 of this embodiment, the first light receiving unit 51 receives the green light LG emitted from the first light emitting unit 50 and propagated through the measurement site M, and generates a detection signal corresponding to the intensity of the received light. The second light receiving unit 61 receives the red light LR emitted from the second light emitting unit 60 and propagated through the measurement site M, or the near-infrared light LI emitted from the third light emitting unit 70 and propagated through the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0063] In the present embodiment, the light receiving unit 12 receives each light in synchronization with the light emission timing of the light emitting units 50 , 60 , 70 driven in a time-division manner, and generates a detection signal corresponding to each light.

[0064] The light receiving unit 12 transmits the detection signals generated by the light receiving units 51 and 61 to the output circuit 14. The output circuit 14 is configured to include, for example, an A / D converter that converts the detection signals generated by the light receiving units 51 and 61 from analog to digital, and an amplifier circuit that amplifies the converted detection signals (both not shown). The output circuit 14 generates a plurality of detection signals S (S1, S2, S3) corresponding to different wavelengths.

[0065] Here, the detection signal S1 is a signal indicating the intensity of light received by the first light receiving unit 51 when receiving the green light LG emitted from the first light emitting unit 50. The detection signal S2 is a signal indicating the intensity of light received by the second light receiving unit 61 when receiving the red light LR emitted from the second light emitting unit 60. The detection signal S3 is a signal indicating the intensity of light received by the second light receiving unit 61 when receiving the near-infrared light LI emitted from the third light emitting unit 70.

[0066] Generally, the amount of light absorbed by blood differs when a blood vessel dilates and contracts, so each detection signal S becomes a pulse signal including a periodically varying component corresponding to the pulsation component (volume pulse) of the artery inside the measurement site M.

[0067] The drive circuit 13 and the output circuit 14 are mounted on a wiring board in the form of IC chips together with the light emitting unit 11 and the light receiving unit 12. As described above, the drive circuit 13 and the output circuit 14 can also be provided outside the detection device 3.

[0068] The control device 5 is an arithmetic processing device such as a CPU (Central Processing Unit) or an FPGA (Field-Programmable Gate Array), and controls the entire measuring device 100. The storage device 6 is composed of, for example, a non-volatile semiconductor memory, and stores programs executed by the control device 5 and various data used by the control device 5. Alternatively, a structure may be adopted in which the functions of the control device 5 are distributed among a plurality of integrated circuits, or a structure in which a part or all of the functions of the control device 5 are implemented by a dedicated electronic circuit. In addition, in Figure 2 In the figure, the control device 5 and the storage device 6 are shown as separate components, but the control device 5 with a built-in storage device 6 can also be implemented by, for example, an ASIC (Application Specific Integrated Circuit).

[0069] The control device 5 of this embodiment executes a program stored in the storage device 6 to identify the biological information of the person being measured based on the plurality of detection signals S ( S1 , S2 , S3 ) generated by the detection device 3 .

[0070] Specifically, the control device (information analysis unit) 5 determines the subject's pulse based on detection signal S1, which indicates the intensity of green light LG received by the first light receiving unit 51. For example, the control device 5 can determine the subject's pulse interval (PPI) based on detection signal S1. Furthermore, the control device 5 can determine the subject's oxygen saturation (SpO2) by analyzing detection signal S2, which indicates the intensity of red light LR received by the second light receiving unit 61, and detection signal S3, which indicates the intensity of near-infrared light LI received by the second light receiving unit 61.

[0071] As described above, in the measurement device 100, the control device 5 functions as an information analysis unit that determines biological information based on the detection signal S representing the detection result of the detection device 3. The control device 5 causes the display device 4 to display the biological information determined based on the detection signal S. Furthermore, the measurement result can be notified to the user via audio output. It is also preferable to have a configuration that issues a warning (possibility of bodily dysfunction) to the user if the pulse rate or oxygen saturation fluctuates to a value outside a predetermined range.

[0072] like Figure 3As shown in FIG. 1 , the width of the first light receiving portion 51 along the X-axis is smaller than the width of the second light receiving portion 61 along the X-axis. In the case of the detection device 3 of this embodiment, the area of ​​the first light receiving portion 51 is smaller than the area of ​​the second light receiving portion 61. Here, the areas of the first light receiving portion 51 and the second light receiving portion 61 refer to the planar areas when viewed from the +Z side. In the case of this embodiment, the area of ​​the first light receiving portion 51 is set to be equal to the area of ​​the second light receiving portion 61. Figure 3 The simulation results show the size of the light incident area 7 where the green light that has passed through the biological body is concentrated. In the detection device 3 of this embodiment, a structure is adopted in which the size of the first light receiving part 51 that receives the green light LG is smaller than the size of the light receiving part generally used in the past. In the case of this embodiment, the size of the first light receiving part 51 is about half of the size of the light receiving part generally used in the past. In addition, the unit price of the light receiving part depends on the area. Therefore, in the case of this embodiment, by miniaturizing the size of the first light receiving part 51, cost reduction can be achieved.

[0073] According to the light receiving unit 12 of this embodiment, even when the size of the first light receiving unit 51 is reduced, it is still possible to receive a sufficient amount of green light LG after passing through the living body. Therefore, the detection device 3 of this embodiment does not need to increase the current consumption of the first light emitting unit 50 to increase the emission amount of green light LG, thereby achieving low power consumption of the light emitting unit 11.

[0074] Furthermore, in the detection device 3 of this embodiment, a portion of the second light receiving unit 61 that receives red light LR or near-infrared light LI is arranged to overlap a portion of the space created by miniaturizing the first light receiving unit 51 that receives green light LG. Specifically, the detection device 3 of this embodiment employs a structure in which the second light receiving unit 61 is disposed in the space created by miniaturizing the first light receiving unit 51, thereby positioning the second light receiving unit 61 closer to the light emitting unit 11. Therefore, in the detection device 3 of this embodiment, the size of the light receiving unit 12, which includes the first light receiving unit 51 and the second light receiving unit 61, is reduced, enabling the device structure to be miniaturized.

[0075] Furthermore, in the detection device 3 of this embodiment, a second light receiving unit 61 for receiving red light LR or near-infrared light LI is disposed at a position distant from the second light emitting unit 60 or the third light emitting unit 70. In the detection device 3 of this embodiment, the distance (distance D2 or distance D3) between the second light emitting unit 60 or the third light emitting unit 70 and the second light receiving unit 61 is greater than the distance D1 between the first light emitting unit 50 and the first light receiving unit 51. In other words, the distance that the red light LR and the near-infrared light LI propagate within the body before entering the second light receiving unit 61 is greater than the distance that the green light LG propagates within the body before entering the first light receiving unit 51.

[0076] like Figure 5 As shown, the longer the propagation distance of red light LR or near-infrared light LI within a living body, the less noise is generated by components reflected from the surface of the living body and not passing through the blood, i.e., when determining the blood oxygen concentration. The second light receiving unit 61 of this embodiment can achieve a high S / N ratio by suppressing the incidence of noise components. Therefore, the detection device 3 of this embodiment can accurately receive red light LR or near-infrared light LI at the second light receiving unit 61.

[0077] On the other hand, if the propagation distance of red light LR or near-infrared light LI within a living body is too long, it is necessary to increase the light output of the second light-emitting section 60 or the third light-emitting section 70. In this embodiment, the second light-receiving section 61 is provided in the space created by miniaturizing the first light-receiving section 51. This allows the second light-receiving section 61 to be positioned closer to the light-emitting unit 11, thereby arranging the second light-receiving section 61, the second light-emitting section 60, and the third light-emitting section 70 in appropriate positions. This ensures the accuracy of receiving red light LR and near-infrared light LI, while also reducing the power consumption of the second light-receiving section 60 or the third light-emitting section 70, thereby reducing the power consumption of the light-emitting unit 11.

[0078] like Figure 4 As shown, the first light receiving unit 51 includes a light receiving element (first sensor unit) 120, an angle limiting filter (first angle limiting filter) 121, and a bandpass filter 122. The first light receiving unit 51 of this embodiment includes a single light receiving element 120.

[0079] The light receiving element 120 is composed of, for example, a photodiode (PD). The angle limiting filter 121 is provided so as to cover the entire light receiving surface 120a of the light receiving element 120. The angle limiting filter 121 is formed by, for example, embedding a plug 1212 made of a light-shielding material such as tungsten within a light-transmitting silicon oxide layer 1211.

[0080] Silicon oxide layer 1211 forms an optical path that guides light to light-receiving surface 120a of light-receiving element 120. Plug 1212 embedded in silicon oxide layer 1211 limits the angle of incidence of light passing through the optical path (silicon oxide layer 1211). Specifically, when light entering silicon oxide layer 1211 is tilted at a predetermined angle relative to the optical path, the incident light strikes plug 1212, where a portion of the light is absorbed and the remainder is reflected. Furthermore, due to repeated reflections before passing through the optical path, the intensity of the reflected light decreases. Consequently, the light that ultimately passes through angle-limiting filter 121 is essentially limited to light whose tilt relative to the optical path is within the predetermined limiting angle.

[0081] The angle-limiting filter 121 has the following characteristics: it transmits light incident at an angle smaller than a predetermined angle of incidence, while blocking light incident at an angle greater than the predetermined angle of incidence. Thus, the angle-limiting filter 121 can limit the angle of incidence of light incident on the light-receiving element 120. Specifically, the angle-limiting filter 121 transmits light incident at a predetermined angle of incidence (hereinafter referred to as the permitted angle of incidence) due to propagation within the body, while blocking light incident at angles greater than the permitted angle of incidence, such as external light such as sunlight or light not incident within the body.

[0082] The bandpass filter 122 selectively transmits green light LG in the wavelength band and absorbs and blocks red light LR and near-infrared light LI, which are light in other wavelength bands. The bandpass filter 122 is formed, for example, by alternately stacking a plurality of low-refractive-index layers such as silicon oxide and a plurality of high-refractive-index layers such as titanium oxide on the angle limiting filter 121.

[0083] Furthermore, the second light receiving unit 61 includes a light receiving element (second sensor unit) 220 that receives red light LR or near-infrared light LI, and an angle limiting filter (second angle limiting filter) 221 that limits the angle of incidence of the red light LR or near-infrared light LI on the light receiving element 220. Specifically, in the detection device 3 of this embodiment, the second light receiving unit 61 differs from the first light receiving unit 51 in that it does not include a bandpass filter that selectively transmits the red light LR or near-infrared light LI.

[0084] The light receiving element 220 is composed of, for example, a photodiode. An angle limiting filter 221 is provided on the light receiving surface 220a of the light receiving element 220. The angle limiting filter 221 has the same structure as the angle limiting filter 121 and is capable of limiting the angle of incidence of red light LR or near-infrared light LI reaching the light receiving element 220. For example, the angle limiting filter 221 transmits red light LR or near-infrared light LI that propagates within the body and enters at a permissible angle of incidence, while blocking light that enters at an angle greater than the permissible angle of incidence, such as external light such as sunlight, or red light LR or near-infrared light LI that has not passed through the body.

[0085] Here, a portion of the red light LR and near-infrared light LI emitted from the second light-emitting section 60 sometimes passes through the body and enters the light-receiving section 51. In this embodiment, the first light-receiving section 51 includes a bandpass filter 122 that selectively transmits the green light LG. Therefore, the first light-receiving section 51 can block the red light LR and near-infrared light LI having wavelengths different from those of the green light LG. Consequently, the first light-receiving section 51 can efficiently receive the green light LG emitted from the light-emitting section 50.

[0086] Figure 7It is a diagram for explaining the operation of the detection device 3.

[0087] like Figure 7 As shown, in the detection device 3 of this embodiment, a portion of the green light LG emitted from the first light-emitting section 50 is reflected by, for example, the surface of the living body (measurement site M), and may enter the first light-receiving section 51 directly without passing through the living body. Furthermore, external light such as sunlight may enter the first light-receiving section 51 directly through the gap between the living body and the detection surface 16. Hereinafter, the green light LG that does not pass through the living body and enters the first light-receiving section 51 is referred to as "first stray light component SL1," and the external light that directly enters the first light-receiving section 51 is referred to as "second stray light component SL2."

[0088] Since the first stray light component SL1 has a green wavelength band, it passes through the bandpass filter 122 and enters the angle limiting filter 121 provided below the bandpass filter 122. As described above, the angle limiting filter 121 has the characteristic of transmitting light incident at an angle smaller than the permissible incident angle and blocking light incident at an angle larger than the permissible incident angle.

[0089] Because the first stray light component SL1 enters the first light receiving unit 51 without passing through the living body, the angle of incidence of the green light LG with respect to the first light receiving unit 51 is greater than the permissible angle of incidence of the angle limiting filter 121. In other words, the first stray light component SL1 is blocked by the angle limiting filter 121. Thus, the first light receiving unit 51 can suppress the incidence of the first stray light component SL1 on the light receiving surface 120a of the light receiving element 120 through the angle limiting filter 121.

[0090] The second stray light component SL2 is substantially blocked by the bandpass filter 122, but the green-band component included in the second stray light component SL2 passes through the bandpass filter 122. As described above, since the second stray light component SL2 enters the gap between the living body and the detection surface 16, the angle of incidence of the second stray light component SL2 with respect to the first light receiving unit 51 is greater than the permissible angle of incidence of the angle limiting filter 121. Therefore, a portion of the second stray light component SL2 that passes through the bandpass filter 122 (the green-band component) is blocked by the angle limiting filter 121. Thus, the first light receiving unit 51 can suppress the second stray light component SL2 from entering the light receiving surface 120a of the light receiving element 120 through the angle limiting filter 121.

[0091] In this manner, the detection device 3 of this embodiment can efficiently cause the green light LG emitted from the light emitting unit 11 and passing through the living body to enter the light receiving surface 120a of the light receiving element 120. Furthermore, the detection device 3 of this embodiment can prevent the first stray light component SL1 and the second stray light component SL2 from entering the light receiving surface 120a of the light receiving element 120.

[0092] Therefore, the first light receiving unit 51 can achieve a high S / N ratio by suppressing the incidence of the first and second stray light components SL1 and SL2, which constitute noise components. Therefore, the detection device 3 of this embodiment can accurately receive the green light LG in the first light receiving unit 51, thereby suppressing the amount of green light LG emitted by the first light emitting unit 50 and thereby reducing power consumption of the light emitting unit 11.

[0093] In addition, there are cases where a portion of the red light LR emitted from the second light-emitting section 60 or a portion of the near-infrared light LI emitted from the third light-emitting section 70 directly enters the second light-receiving section 61 without passing through the living body. In addition, there are cases where external light such as sunlight directly enters the second light-receiving section 61 through the gap between the living body and the detection surface 16. Hereinafter, the red light LR or near-infrared light LI that directly travels toward the second light-receiving section 61 without passing through the living body will be collectively referred to as the "third stray light component SL3," and the external light that directly travels toward the second light-receiving section 61 will be referred to as the "fourth stray light component SL4."

[0094] Since the third stray light component SL3 does not pass through the living body but enters the angle limiting filter 221, the angle of incidence of the third stray light component SL3 with respect to the second light receiving unit 61 is greater than the permissible angle of incidence of the angle limiting filter 221. Furthermore, since the fourth stray light component SL4 enters from the gap between the living body and the detection surface 16, the angle of incidence of the fourth stray light component SL4 with respect to the second light receiving unit 61 is greater than the permissible angle of incidence of the angle limiting filter 221.

[0095] Therefore, the third and fourth stray light components SL3 and SL4 are well cut off by the angle limiting filter 221. Thus, the second light receiving unit 61 can suppress the third and fourth stray light components SL3 and SL4 from being incident on the light receiving surface 220a of the light receiving element 120 through the angle limiting filter 221.

[0096] In this manner, the detection device 3 of this embodiment can efficiently cause the red light LR or near-infrared light LI emitted from the light-emitting unit 11 and passing through the living body to enter the light-receiving surface 220a of the light-receiving element 220. Furthermore, the detection device 3 of this embodiment can prevent the third stray light component SL3 and the fourth stray light component SL4 from entering the light-receiving surface 220a of the light-receiving element 220.

[0097] Therefore, the second light receiving unit 61 can achieve a high S / N ratio by suppressing the incidence of the third and fourth stray light components SL3 and SL4, which constitute noise components. According to the detection device 3 of this embodiment, since the second light receiving unit 61 efficiently receives the red light LR and the near-infrared light LI, it is possible to suppress the amount of light emitted by the second light emitting unit 60 and the third light emitting unit 70, thereby reducing the power consumption of the light emitting unit 11.

[0098] Furthermore, in this embodiment, since only red light LR and near-infrared light LI enter the second light receiving section 61, a bandpass filter that selectively transmits red light LR and near-infrared light LI and blocks green light LG is not provided in the second light receiving section 61. In other words, the detection device 3 of this embodiment can be configured such that only the first light receiving section 51 includes the bandpass filter 122, while the second light receiving section 61 does not. Therefore, the detection device 3 of this embodiment can achieve cost reduction by omitting the bandpass filter from the second light receiving section 61.

[0099] According to the detection device 3 of this embodiment, even when the light emission of each light-emitting unit 50, 60, and 70 is suppressed to achieve low power consumption of the light-emitting unit 11, the light-receiving unit 12 can still receive light passing through the living body with high accuracy. In addition, in the detection device 3 of this embodiment, by omitting the bandpass filter in the second light-receiving unit 61, cost reduction can be achieved.

[0100] As described above, the detection device 3 of this embodiment includes: a first light-emitting section 50 that emits green light LG; a second light-emitting section 60 that emits red light LR having a wavelength higher than that of the green light LG; a third light-emitting section 70 that emits near-infrared light LI having a wavelength higher than that of the green light LG; a first light-receiving section 51 that receives the green light LG emitted from the first light-emitting section 50 and emitted from the measurement site M; and a second light-receiving section 61 that receives the red light LR or near-infrared light LI emitted from the second light-emitting section 60 or the third light-receiving section 70 and emitted from the measurement site M. In the direction along the X-axis, the first light-receiving section 51 is positioned closer to the first light-emitting section 50 than the second light-receiving section 61, and the area of ​​the first light-receiving section 51 is smaller than that of the second light-receiving section 61. The first light-receiving section 51 includes a single light-receiving element 120, and the width of the first light-receiving section 51 along the X-axis is smaller than the width of the second light-receiving section 61 along the X-axis.

[0101] The detection device 3 of the present embodiment includes a first light receiving portion 51, the size of which corresponds to the light incident area 7 where the green light LG that has passed through the biological body is concentratedly incident. The size of the first light receiving portion 51 is smaller than the size of the light receiving portion generally used in the past. A portion of the second light receiving portion 61 is arranged so as to overlap with a portion of the space generated by miniaturizing the first light receiving portion 51, so that the second light receiving portion 61 and the light emitting unit portion 11 are arranged close to each other. Therefore, according to the detection device 3 of the present embodiment, the size of the light receiving unit portion 12 including the first light receiving portion 51 and the second light receiving portion 61 can be reduced, so that the device structure can be miniaturized. Therefore, a small detection device 3 that can obtain both the pulse interval and the oxygen saturation can be provided. In addition, by miniaturizing the size of the first light receiving portion 51, the cost can be reduced.

[0102] The detection device 3 of this embodiment further includes a flat light-shielding wall 41 . The light-shielding wall 41 is provided between the first light-emitting unit 50 and the first light-receiving unit 51 and blocks at least a portion of the green light LG.

[0103] According to the detection device 3 of this embodiment, since the flat-plate-shaped light-shielding wall 41 is provided, the device structure can be miniaturized in the width direction of the light-shielding wall 41 , that is, in the direction along the X-axis.

[0104] (Second embodiment)

[0105] Next, the detection device of the second embodiment is described. In the first embodiment, the first light receiving unit 51 is constituted by a single light receiving element. However, the detection device of this embodiment differs from the first embodiment in that the first light receiving unit is constituted by two light receiving elements.

[0106] Figure 8 It is a cross-sectional view of the detection device according to this embodiment. Figure 8 This is in contrast to the first embodiment. Figure 3 In addition, the same reference numerals are given to the structures and components that are common to the first embodiment, and detailed descriptions are omitted. Figure 8 , for convenience of explanation, light incident areas 7a and 7b where the green light LG that has passed through the biological body is concentrated are shown on the -Z side of the detection device 103.

[0107] like Figure 8 As shown, the light receiving unit 112 in the detection device 103 of this embodiment includes a first light receiving unit 151 and a second light receiving unit 61. The first light receiving unit 151 of this embodiment includes a first light receiving portion 1511 and a second light receiving portion 1512. The first light receiving portion 1511 and the second light receiving portion 1512 are arranged in the direction along the X-axis with the first light emitting unit 50 therebetween.

[0108] In the present embodiment, the first light receiving portion 1511 is provided on the +X side of the first light emitting portion 50, and the second light receiving portion 1512 is provided on the -X side of the first light emitting portion 50. The first light receiving portion 1511 and the second light receiving portion 1512 have the same structure as the first light receiving portion 51 of the first embodiment, differing only in size. The first light receiving portion 1511 and the second light receiving portion 1512 have the same area as each other. The first light receiving portion 1511 and the second light receiving portion 1512 each have an area obtained by dividing the first light receiving portion 51 of the first embodiment into half. Therefore, in the present embodiment, the total area of ​​the first light receiving portion 1511 and the second light receiving portion 1512 is smaller than the area of ​​the second light receiving portion 61.

[0109] Here, the first light receiving portion 1511 and the second light receiving portion 1512 have an area half that of the first light receiving section 51, and therefore the unit price of the first light receiving portion 1511 and the second light receiving portion 1512 is lower than that of the first light receiving section 51. Therefore, according to this embodiment, by configuring the first light receiving section 151 using the first light receiving portion 1511 and the second light receiving portion 1512, which have a low unit price, the cost of the detection device 103 can be suppressed.

[0110] The detection device 103 of this embodiment further includes a first light-shielding wall 141 and a second light-shielding wall 142 .

[0111] The first light-shielding wall 141 is positioned along the X-axis between the light-emitting unit 11 and the first light-receiving portion 1511. The first light-shielding wall 141 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends in the Y-axis direction. The first light-shielding wall 141 is a light-shielding member that blocks light emitted from the light-emitting unit 11 from directly entering the first light-receiving portion 1511 or the second light-receiving portion 61.

[0112] The second light-shielding wall 142 is positioned along the X-axis between the light-emitting unit 11 and the second light-receiving portion 1512. The second light-shielding wall 142 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends in the Y-axis direction. The second light-shielding wall 142 is a light-shielding member that blocks light emitted from the light-emitting unit 11 from directly entering the second light-receiving portion 1512.

[0113] The detection device 103 of this embodiment includes the first light-shielding wall 141 and the second light-shielding wall 142 , thereby dividing the storage space in the housing 40 into three in the X-axis direction.

[0114] The first light-receiving portion 1511 is provided at a position corresponding to the light incident region 7a, which is formed on the +X side of the first light-emitting portion 50 by the green light LG emitted from the first light-emitting portion 50 and transmitted through the living body. The first light-receiving portion 1511 has an area half that of the light-receiving portion 51 of the first embodiment. In other words, the first light-receiving portion 1511 can receive approximately half the amount of light incident on the light incident region 7a on the +X side of the first light-emitting portion 50.

[0115] In the present embodiment, the second light receiving portion 61 is shifted toward the −X side by the amount by which the width of the first light receiving portion 1511 in the X direction is reduced, thereby suppressing an increase in the size in the X direction.

[0116] Here, the green light LG is emitted radially in various directions from the first light emitting section 50. Therefore, the green light LG having passed through the living body is also concentrated on the -X side of the first light emitting section 50, thereby forming another light incident area 7b.

[0117] The second light-receiving portion 1512 is provided at a position corresponding to the light incident region 7b, which is formed on the -X side of the first light-emitting portion 50 by the green light LG emitted from the first light-emitting portion 50 and transmitted through the living body. Like the first light-receiving portion 1511, the second light-receiving portion 1512 has an area half that of the light-receiving portion 51 of the first embodiment. In other words, the second light-receiving portion 1512 can receive approximately half the amount of light incident on the -X side of the light incident region 7b of the first light-emitting portion 50.

[0118] The total amount of light received by the first light receiving portion 1511 and the second light receiving portion 1512 is equal to the amount of light received by the light receiving unit 51 of the first embodiment. Therefore, according to the detection device 103 of this embodiment, as in the first embodiment, it is possible to efficiently receive green light LG, achieve cost reduction, and reduce the device structure.

[0119] (Third embodiment)

[0120] Next, a detection device according to a third embodiment will be described. The detection device according to this embodiment differs from the other embodiments in that the first light receiving unit is composed of four light receiving elements.

[0121] Figure 9 It is a cross-sectional view of the detection device according to this embodiment. Figure 9 This is in contrast to the first embodiment. Figure 3 Note that the same reference numerals are given to the same structures and components as those in the first embodiment, and detailed description thereof will be omitted.

[0122] like Figure 9As shown, the light receiving unit 212 in the detection device 203 of this embodiment includes a first light receiving unit 251 and a second light receiving unit 61. The first light receiving unit 251 of this embodiment includes a first light receiving portion 2511, a second light receiving portion 2512, a third light receiving portion 2513, and a fourth light receiving portion 2514.

[0123] The first light receiving section 2511 and the second light receiving section 2512 are arranged with the first light emitting section 50 interposed therebetween in the direction along the X axis, and the third light receiving section 2513 and the fourth light receiving section 2514 are arranged with the first light emitting section 50 interposed therebetween in the direction along the Y axis.

[0124] In this embodiment, the first light receiving portion 2511 is provided on the +X side of the first light emitting unit 50, and the second light receiving portion 2512 is provided on the -X side of the first light emitting unit 50. The third light receiving portion 2513 is provided on the +Y side of the first light emitting unit 50, and the fourth light receiving portion 2514 is provided on the -Y side of the first light emitting unit 50.

[0125] The first light receiving portion 2511, the second light receiving portion 2512, the third light receiving portion 2513, and the fourth light receiving portion 2514 have the same structure as the light receiving portion 51 of the first embodiment, differing only in size. Each light receiving portion 2511 to 2514 has the same area as one another. Each light receiving portion 2511 to 2514 has an area obtained by dividing the first light receiving portion 251 of the first embodiment into four parts. Therefore, in this embodiment, the total area of ​​each light receiving portion 2511 to 2514 is smaller than the area of ​​the second light receiving portion 61. The detection device 203 of this embodiment uses the low-priced light receiving portions 2511 to 2514 to form the first light receiving portion 251, thereby achieving cost reduction.

[0126] The detection device 203 of this embodiment further includes a first light-shielding wall 241 , a second light-shielding wall 242 , a third light-shielding wall 243 , and a fourth light-shielding wall 244 .

[0127] The first light-shielding wall 241 is positioned along the X-axis between the light-emitting unit 11 and the first light-receiving portion 2511. The first light-shielding wall 241 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends in the Y-axis direction. The first light-shielding wall 241 is a light-shielding member that blocks light emitted from the light-emitting unit 11 from directly entering the first light-receiving portion 2511 or the second light-receiving portion 61.

[0128] The second light-shielding wall 242 is positioned along the X-axis between the light-emitting unit 11 and the second light-receiving portion 2512. The second light-shielding wall 242 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends in the Y-axis direction. The second light-shielding wall 242 is a light-shielding member that blocks light emitted from the light-emitting unit 11 from directly entering the second light-receiving portion 2512.

[0129] The third light-shielding wall 243 is positioned along the Y-axis between the first light-emitting section 50 and the third light-receiving section 2513. The third light-shielding wall 243 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends along the X-axis. The third light-shielding wall 243 is provided to connect the first light-shielding wall 241 and the second light-shielding wall 242. The third light-shielding wall 243 is a light-shielding member that blocks light emitted from the first light-emitting section 50 from directly entering the third light-receiving section 2513.

[0130] In the case of this embodiment, the third light receiving portion 2513 is provided between the third light shielding wall 243 and the second light emitting unit 60 in the direction along the Y axis.

[0131] The fourth light-shielding wall 244 is positioned along the Y-axis between the first light-emitting section 50 and the fourth light-receiving section 2514. The fourth light-shielding wall 244 is a flat plate-shaped member that protrudes from the bottom portion 40a toward the +Z side and extends along the X-axis. The fourth light-shielding wall 244 is provided to connect the first light-shielding wall 241 and the second light-shielding wall 242. The fourth light-shielding wall 244 is a light-shielding member that blocks light emitted from the first light-emitting section 50 from directly entering the fourth light-receiving section 2514.

[0132] In the case of this embodiment, the fourth light receiving portion 2514 is provided between the fourth light shielding wall 244 and the third light emitting unit 70 in the direction along the Y axis.

[0133] The detection device 203 of this embodiment includes the first light-shielding wall 241 , the second light-shielding wall 242 , the third light-shielding wall 243 , and the fourth light-shielding wall 244 , thereby dividing the storage space in the housing 40 into five spaces.

[0134] The first light-receiving portion 2511 is provided corresponding to the light incident region where the green light LG emitted from the first light-emitting section 50 and transmitted through the living body is concentrated on the +X side of the first light-emitting section 50. The first light-receiving portion 2511 has an area that is one-fourth that of the light-receiving section 51 of the first embodiment. In other words, the first light-receiving portion 2511 can receive approximately one-fourth the amount of light incident on the light incident region on the +X side of the first light-emitting section 50.

[0135] In the present embodiment, the second light receiving portion 61 is shifted toward the −X side by the amount by which the width of the first light receiving portion 2511 in the X direction is reduced, thereby suppressing an increase in the size in the X direction.

[0136] In addition, the green light LG that has passed through the biological body is also concentrated on the -X side, +Y side, and -Y side of the first light emitting section 50, thereby forming light incident areas respectively.

[0137] The second light-receiving portion 2512 is provided to correspond to the light incident region formed on the -X side of the first light-receiving portion 50 by the green light LG emitted from the first light-receiving portion 50 and transmitted through the living body. Like the first light-receiving portion 2511, the second light-receiving portion 2512 has an area that is one-fourth that of the light-receiving portion 51 of the first embodiment. In other words, the second light-receiving portion 2512 can receive approximately one-fourth of the amount of light incident on the -X side of the first light-receiving portion 50.

[0138] The third light receiving portion 2513 is provided corresponding to the light incident area formed on the +Y side of the first light emitting portion 50 by the green light LG emitted from the first light emitting portion 50 and transmitted through the biological body. The third light receiving portion 2513 can receive approximately 1 / 4 of the light incident area on the +Y side of the first light emitting portion 50.

[0139] The fourth light receiving portion 2514 is provided corresponding to the light incident region formed on the -Y side of the first light emitting portion 50 by the green light LG emitted from the first light emitting portion 50 and transmitted through the biological body. The fourth light receiving portion 2514 can receive approximately 1 / 4 of the light incident region on the -Y side of the first light emitting portion 50.

[0140] The total amount of light received by each of the light receiving portions 2511 to 2514 is equal to the amount of light received by the light receiving unit 51 of the first embodiment. Therefore, according to the detection device 203 of this embodiment, as in the first embodiment, it is possible to efficiently receive green light LG, achieve cost reduction, and reduce the device structure.

[0141] As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the said embodiment, It can implement|achieve various forms within the range which does not deviate from the summary.

[0142] For example, in the above-mentioned embodiment, a human is exemplified as a living body, but the present invention can also be applied to the measurement of living body information (eg, pulse) of other animals.

[0143] In addition, in the above embodiment, the case where the first light receiving unit is composed of two or four light receiving elements is cited as an example, but the number of light receiving elements constituting the first light receiving unit is not limited to this. For example, the first light receiving unit may be composed of three, five, or more light receiving elements.

[0144] In the measurement device 100 of the above embodiment, the detection device 3 is provided in the case 1 as an example. However, the installation location of the detection device 3 is not limited thereto, and the detection device 3 may be embedded in the wristband 2, for example.

[0145] In addition, as the measuring device 100 of the above-mentioned embodiment, a watch-type structure is listed as an example, but the present invention can also be applied to, for example, a structure worn on the neck of the person being measured as a necklace type, a structure worn on the body of the person being measured as a sticker type, and a structure worn on the head of the person being measured as a head-mounted display type.

[0146] In the above embodiment, the case where the bandpass filter 122 is provided only in the first light receiving unit 51 is taken as an example. However, a bandpass filter that selectively transmits red light LR or near-infrared light LI may also be provided in the second light receiving unit 61 .

[0147] In addition, in the detection devices 3 and 103 of the above-mentioned embodiments, the case where each light-emitting unit 50, 60, and 70 is made to emit light in a time-sharing manner is cited as an example. However, since there is a first light-receiving unit 51 and 151 corresponding to the green light LG of the light-emitting unit 50 separately, the light-emitting unit 50 can also be made to light up all the time without being time-sharing.

[0148] The detection device according to one embodiment of the present invention may have the following structure.

[0149] A detection device according to one embodiment of the present invention comprises: a first light-emitting portion that emits a first light having a green wavelength band; a second light-emitting portion that emits a second light having a wavelength band longer than the green wavelength band; a first light-receiving portion that receives the first light emitted from the first light-emitting portion and emitted from the biological body; and a second light-receiving portion that receives the second light emitted from the second light-emitting portion and emitted from the biological body. When the direction in which the first light-emitting portion and the second light-emitting portion are arranged is the first direction and the direction intersecting the first direction is the second direction, in the second direction, at least a portion of the first light-receiving portion is arranged closer to the first light-emitting portion than the second light-receiving portion, and the area of ​​the first light-receiving portion is smaller than the area of ​​the second light-receiving portion.

[0150] In the detection device according to one aspect of the present invention, the first light receiving unit may include a bandpass filter that selectively transmits the first light.

[0151] In one embodiment of the detection device of the present invention, the following structure can also be set: the first light receiving part includes: a first sensor part, which receives the first light; and a first angle limiting filter, which limits the incident angle of the first light reaching the first sensor part; the second light receiving part includes: a second sensor part, which receives the second light; and a second angle limiting filter, which limits the incident angle of the second light reaching the second sensor part.

[0152] The detection device according to one embodiment of the present invention may further include a flat light-shielding wall provided between the first light-emitting unit and the first light-receiving unit to shield at least a portion of the first light.

[0153] In the detection device according to one aspect of the present invention, the first light receiving portion may include a single light receiving element, and the width of the first light receiving portion in the second direction may be smaller than the width of the second light receiving portion in the second direction.

[0154] In the detection device according to one embodiment of the present invention, the first light receiving unit may include a first light receiving portion and a second light receiving portion, and the first light receiving portion and the second light receiving portion may be arranged in the second direction with the first light emitting portion interposed therebetween.

[0155] In the detection device according to one aspect of the present invention, a configuration may be adopted in which the total area of ​​the first light receiving portion and the second light receiving portion is smaller than the area of ​​the second light receiving portion.

[0156] In a detection device of one embodiment of the present invention, the following structure can also be set: the first light receiving part includes a first light receiving portion, a second light receiving portion, a third light receiving portion and a fourth light receiving portion, the first light receiving portion and the second light receiving portion are arranged in the second direction with the first light emitting portion separated therefrom, the third light receiving portion and the fourth light receiving portion are arranged in the first direction with the first light emitting portion separated therefrom, a first flat-plate-shaped light-shielding wall that blocks at least a portion of the first light is provided between the first light emitting portion and the first light receiving portion, a second flat-plate-shaped light-shielding wall that blocks at least a portion of the first light is provided between the first light emitting portion and the second light receiving portion, a third flat-plate-shaped light-shielding wall that blocks at least a portion of the first light is provided between the first light emitting portion and the third light receiving portion, and a fourth flat-plate-shaped light-shielding wall that blocks at least a portion of the first light is provided between the first light emitting portion and the fourth light receiving portion.

[0157] In the detection device according to one aspect of the present invention, a configuration may be adopted in which the total area of ​​the first light receiving portion, the second light receiving portion, the third light receiving portion, and the fourth light receiving portion is smaller than the area of ​​the second light receiving portion.

[0158] In one embodiment of the present invention, the detection device can also be set to the following structure: the detection device also has a third light-emitting portion that emits a third light, the third light emitted from the third light-emitting portion and emitted from the biological body is received by the second light-receiving portion, the third light-receiving portion is arranged between the third light-shielding wall and the second light-emitting portion in the first direction, and the fourth light-receiving portion is arranged between the fourth light-shielding wall and the third light-emitting portion in the first direction.

[0159] The measuring device according to one embodiment of the present invention may have the following configuration.

[0160] A measurement device according to one embodiment of the present invention includes: the detection device according to the above embodiment; and an information analysis unit that determines biological information based on a detection signal indicating a detection result of the detection device.

Claims

1. A detection device, wherein: The detection device has: a first light emitting portion emitting a first light having a green wavelength band; a second light emitting portion that emits a second light having a wavelength longer than the green wavelength; a first light receiving unit that receives the first light emitted from the first light emitting unit and emitted from the living body; and a second light receiving unit for receiving the second light emitted from the second light emitting unit and emitted from the living body; When the direction in which the first light emitting portion and the second light emitting portion are arranged is defined as a first direction and a direction intersecting the first direction is defined as a second direction, In the second direction, the first light receiving portion is arranged closer to the first light emitting portion than the second light receiving portion. The area of ​​the first light receiving portion is smaller than the area of ​​the second light receiving portion. By making the distance between the second light emitting unit and the second light receiving unit longer than the distance between the first light emitting unit and the first light receiving unit, the second light of the first light and the second light is made incident on the second light receiving unit. The first light receiving unit includes a bandpass filter. The first light and the second light enter the bandpass filter, and the bandpass filter selectively transmits the first light.

2. The detection device according to claim 1, wherein The first light receiving unit includes: a first sensor unit that receives the first light; and a first angle limiting filter that limits the incident angle of the first light reaching the first sensor unit. The second light receiving unit includes a second sensor unit that receives the second light and a second angle limiting filter that limits an incident angle of the second light reaching the second sensor unit.

3. The detection device according to claim 1, wherein: The detection device further includes a flat light-shielding wall provided between the first light-emitting section and the first light-receiving section for shielding at least a portion of the first light.

4. The detection device according to claim 1, wherein: The first light receiving unit includes a single light receiving element, The width of the first light receiving portion in the second direction is smaller than the width of the second light receiving portion in the second direction.

5. The detection device according to claim 1, wherein: The first light receiving unit includes a first light receiving portion and a second light receiving portion, The first light receiving portion and the second light receiving portion are arranged with the first light emitting portion interposed therebetween in the second direction.

6. The detection device according to claim 5, wherein: The total area of ​​the first light receiving portion and the second light receiving portion is smaller than the area of ​​the second light receiving portion.

7. The detection device according to claim 1, wherein: The first light receiving unit includes a first light receiving portion, a second light receiving portion, a third light receiving portion and a fourth light receiving portion. The first light receiving portion and the second light receiving portion are arranged in the second direction with the first light emitting portion interposed therebetween. The third light receiving portion and the fourth light receiving portion are arranged in the first direction with the first light emitting portion interposed therebetween. A first light-shielding wall having a flat plate shape and shielding at least a portion of the first light is provided between the first light-emitting portion and the first light-receiving portion. A second light-shielding wall having a flat plate shape and shielding at least a portion of the first light is provided between the first light-emitting portion and the second light-receiving portion. A third light-shielding wall having a flat plate shape is provided between the first light-emitting portion and the third light-receiving portion for shielding at least a portion of the first light. A fourth light-shielding wall having a flat plate shape and shielding at least a portion of the first light is provided between the first light-emitting portion and the fourth light-receiving portion.

8. The detection device according to claim 7, wherein: The total area of ​​the first light receiving portion, the second light receiving portion, the third light receiving portion, and the fourth light receiving portion is smaller than the area of ​​the second light receiving portion.

9. The detection device according to claim 7, wherein: The detection device further comprises a third light emitting portion that emits a third light. The third light emitted from the third light emitting unit and emitted from the living body is received by the second light receiving unit. The third light receiving portion is provided between the third light shielding wall and the second light emitting portion in the first direction. The fourth light receiving portion is provided between the fourth light shielding wall and the third light emitting portion in the first direction.

10. A measuring device, wherein: The measuring device has: The detection device according to any one of claims 1 to 9; as well as An information analysis unit determines biological information based on a detection signal indicating a detection result of the detection device.

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