Detection device and measuring device

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 higher 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, the first light-receiving unit including a bandpass filter that selectively transmits the first light, and a distance from the first light-emitting unit to the first light-receiving unit being shorter than a distance from the second light-emitting unit to 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 reflected by the living organism. The device improves light utilization efficiency of the light-emitting unit and counteracts 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] However, in the above-mentioned detection device, since a thick light shielding member needs to be provided between the plurality of light receiving units, there is a problem in 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 higher 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, the first light-receiving portion including a band-pass filter that selectively transmits the first light, and a distance from the first light-emitting portion to the first light-receiving portion is shorter than a distance from the second light-emitting portion to the second light-receiving portion.

[0006] According to one embodiment of the present invention, a detection device is provided, which 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 higher 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; a second light-receiving portion that receives the second light emitted from the second light-emitting portion and emitted from the biological body; an angle-limiting filter that is arranged on the light-receiving element of the first light-receiving portion and limits the incident angle of the first light reaching the first light-receiving portion; and a band-pass filter that is arranged on the angle-limiting filter and selectively transmits the first light, the distance from the first light-emitting portion to the first light-receiving portion is shorter than the distance from the second light-emitting portion to the second light-receiving portion, and the second light-receiving portion does not have an angle-limiting filter that limits the incident angle of the second light reaching the second light-receiving portion, and a band-pass filter that selectively transmits the second light.

[0007] 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

[0008] Figure 1 It is a side view of the measuring device according to the first embodiment.

[0009] Figure 2 This is a structural diagram focusing on the functions of the measuring device.

[0010] Figure 3 It is a top view of the detection device.

[0011] Figure 4 is based on Figure 3 Cross-sectional view of the IV-IV line arrow.

[0012] Figure 5 is a graph showing the transmission spectrum of skin.

[0013] Figure 6 It is a diagram for explaining the operation of the detection device.

[0014] Figure 7 It is a top view of the detection device according to the second embodiment.

[0015] Figure 8 is based on Figure 7 Cross-sectional view along the VIII-VIII line arrow.

[0016] Figure 9 It is a side view of the measuring device of the third embodiment.

[0017] Figure 10 This is a structural diagram focusing on the functions of the measuring device.

[0018] Figure 11 It is a top view of the detection device.

[0019] Figure 12 is based on Figure 11 Cross-sectional view indicated by the arrows on line IX-IX.

[0020] Figure 13 It is a diagram for explaining the operation of the detection device.

[0021] Figure 14 It is a cross-sectional view of the detection device according to the first modification.

[0022] Figure 15 It is a cross-sectional view of a detection device according to a second modified example.

[0023] Figure 16It is a cross-sectional view of a detection device according to a fourth embodiment.

[0024] Figure 17 This is a diagram showing conditions when a stray light component enters the light receiving section.

[0025] Figure 18 It is a top view of the detection device according to the fifth embodiment.

[0026] Figure 19 is based on Figure 18 Cross-sectional view along the XII-XII line arrow.

[0027] Label Description

[0028] 1: Housing; θ1: Incident angle; 40b1: Inner circumferential surface; 2: Band; 3, 3A, 3B, 3C, 3D, 3E, 3F: Detection device; 4: Display device; 5: Control device; 6: Storage device; 11: Light-emitting unit; 12, 12B: Light-receiving unit; 13: Drive circuit; 14: Output circuit; 16: Detection surface; 40: Housing; 40a: Bottom; 40b: Side panel. 41: Light-shielding wall; 41a: End portion; 42: Sealing layer; 50, 60, 70: Light-emitting portion; 51, 51B, 51F, 61, 61F, 71F: Light-receiving portion; 55: Light-emitting surface; 55a: End surface; 56: Lens; 100, 100B: Measuring device; 112: Light-receiving unit; 140, 141: First light-shielding wall; 141b: End portion; 143: Second light-shielding wall; 143 a: upper end surface; 151, 161, 171: light receiving portion; 212: light receiving unit portion; 251, 261: light receiving portion; 261a: end portion; 510: light receiving element; 510a: light receiving surface; 511: angle limiting filter; 512: silicon oxide layer; 513: plug; 515: bandpass filter; 610: light receiving element; 610a: light receiving surface; 611: angle limiting filter; 61 2: Silicon oxide layer; 613: Plug; 1610: Light receiving element; 1611: Angle limiting filter; 1710: Light receiving element; 1711: Angle limiting filter; 1715: Bandpass filter; D1, D2, D3, D4, D5, D6: Distance; LG: Green light (1st light); LI: Near-infrared light (2nd light); LR: Red light (3rd light); M: Measurement site (biological body). DETAILED DESCRIPTION

[0029] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. In the following drawings, each component is assumed to be of a size that allows for identification, and therefore the scale and angle of each component are different from the actual ones.

[0030] In the following description of each embodiment, the same reference numerals are given to common configurations and components, and detailed description thereof will be omitted.

[0031] (First embodiment)

[0032] Figure 1 It is a side view of the measuring device 100 according to the first embodiment. Figure 1 The 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 organism, 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 organism) M. In the present embodiment, the subject's pulse (e.g., pulse rate) 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.

[0033] 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.

[0034] 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.

[0035] The light emitting unit 11 includes a light emitting unit (first light emitting unit) 50, a light emitting unit (third light emitting unit) 60, and a light emitting unit (second light emitting unit) 70. The light emitting units 50, 60, and 70 are light sources that emit light of different wavelengths toward the measurement site M.

[0036] The 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 in the present embodiment is light having a peak wavelength of 520 nm, for example.

[0037] The light emitting unit 60 emits red light (third light) LR having a red wavelength band 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.

[0038] The light emitting unit 70 emits near-infrared light (second 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 has a peak wavelength of, for example, 905 nm.

[0039] As the light-emitting elements constituting these light-emitting units 50, 60, and 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 light-emitting units 50, 60, and 70 are not specifically distinguished, they are collectively referred to as light-emitting units 50, 60, and 70.

[0040] The drive circuit 13 supplies a drive current to each of the light-emitting units 50, 60, and 70. The drive circuit 13 of this embodiment causes each of the light-emitting units 50, 60, and 70 to periodically emit light in a time-sharing manner. 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 with the light-emitting unit 11 and the light-receiving unit 12 positioned to one side of the measurement site M.

[0041] The light receiving unit 12 receives light arriving from the measurement site M via the light emitting unit 11. The light receiving unit 12 of this embodiment includes a light receiving unit (first light receiving unit) 51 and a light receiving unit (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.

[0042] The light receiving unit 51 receives the green light LG emitted from the 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 light receiving unit 61 receives the red light LR emitted from the light emitting unit 60 and propagated through the measurement site M, or the near-infrared light LI emitted from the light emitting unit 70 and propagated through the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0043] The output circuit 14 is configured to include, for example: an A / D converter that converts the detection signals generated by each light receiving unit 51, 61 from analog to digital; and an amplifier circuit that amplifies the converted detection signals (both omitted in the figure) to generate multiple detection signals S (S1, S2, S3) corresponding to different wavelengths.

[0044] Detection signal S1 is a signal indicating the intensity of light received by light receiving unit 51 when receiving green light LG emitted from light emitting unit 50. Detection signal S2 is a signal indicating the intensity of light received by light receiving unit 61 when receiving red light LR emitted from light emitting unit 60. Detection signal S3 is a signal indicating the intensity of light received by light receiving unit 61 when receiving near-infrared light LI emitted from light emitting unit 70.

[0045] Generally, the amount of light absorbed by blood differs when a blood vessel dilates and contracts. Therefore, each detection signal S becomes a pulse signal including a periodic variation component corresponding to the pulsation component (volume pulse) of the artery inside the measurement site M.

[0046] 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.

[0047] 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).

[0048] The control device 5 of this embodiment determines the biological information of the measured person based on the multiple detection signals S (S1, S2, S3) generated by the detection device 3 by executing a program stored in the storage device 6. Specifically, the control device 5 determines the pulse of the measured person based on the detection signal S1 indicating the light intensity of the green light LG received by the light receiving unit 51. The control device 5 can, for example, determine the pulse rate of the measured person based on the detection signal S1. In addition, the control device 5 can determine the oxygen saturation of the measured person by analyzing the detection signal S2 indicating the light intensity of the red light LR received by the light receiving unit 61 and the detection signal S3 indicating the light intensity of the near-infrared light LI received by the light receiving unit 61.

[0049] As described above, 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 (information analysis unit) 5 causes the display device 4 to display the biological information determined based on the detection signal S. Furthermore, the measurement results can be notified to the user via audio output. A configuration is also preferred that provides a warning (possibility of bodily dysfunction) to the user if the pulse rate or oxygen saturation fluctuates to a value outside a predetermined range.

[0050] 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.

[0051] 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.

[0052] like Figure 3 and Figure 4As 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.

[0053] 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, a structure in which the housing 40 is formed integrally with the housing portion 1 is also preferable.

[0054] The light-emitting unit 11 and the light-receiving unit 12 are mounted on a wiring substrate (not shown) on the bottom portion 40a of the housing 40. 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 plate-shaped component that protrudes from the bottom portion 40a toward 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. In other words, the light-shielding wall 41 is a component that separates the space that accommodates 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.

[0055] In this embodiment, light-shielding wall 41 is provided along the X-axis between light-emitting unit 11 including light-emitting sections 50, 60, and 70 and light-receiving section 51. Light-shielding wall 41 can also be said to be a component that blocks a portion of green light LG, red light LR, and near-infrared light LI.

[0056] 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.

[0057] 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 .

[0058] 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.

[0059] 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 light-emitting section 60 is arranged on the +Y side of the light-emitting section 50, and the light-emitting section 70 is arranged on the -Y side of the light-emitting section 50. In other words, the light-emitting section 50 is arranged between the light-emitting section 60 and the light-emitting section 70 along the Y-axis. Alternatively, the light-emitting section 50 can be said to be located between the light-emitting section 60 and the light-emitting section 70.

[0060] On the other hand, 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.

[0061] like Figure 3 As shown, the light receiving sections 51 and 61 are spaced apart from each other and arranged in a direction (second direction) along the X-axis that intersects (is perpendicular to) the Y-axis. Specifically, the light receiving section 51 is arranged on the +X side of the light emitting unit 11, and the light receiving section 61 is arranged on the +X side of the light receiving section 51. In other words, the light receiving section 61 is arranged on the opposite side of the light emitting unit 11 across the light receiving section 51.

[0062] Here, the distance from the light-emitting section 50 to the light-receiving section 51 is denoted as D1, the distance from the light-emitting section 60 to the light-receiving section 61 is denoted as D2, and the distance from the light-emitting section 70 to the light-receiving section 61 is denoted as D3. Distance D1 corresponds to the distance between the centers of the light-emitting section 50 and the light-receiving section 51 when viewed from above in the Z-axis direction. Distance D2 corresponds to the distance between the centers of the light-emitting section 60 and the light-receiving section 61 when viewed from above in the Z-axis direction. Distance D3 corresponds to the distance between the centers of the light-emitting section 70 and the light-receiving section 61 when viewed from above in the Z-axis direction.

[0063] In the detection device 3 of this embodiment, the distance D1 from the light emitting unit 50 to the light receiving unit 51 is shorter than the distance D2 from the light emitting unit 60 to the light receiving unit 61. Furthermore, the distance D1 from the light emitting unit 50 to the light receiving unit 51 is shorter than the distance D3 from the light emitting unit 70 to the light receiving unit 61. Furthermore, the distance D2 is equal to the distance D3.

[0064] As described above, in the detection device 3 of the present embodiment, a configuration is adopted in which the light receiving unit 51 for receiving the green light LG is arranged at the nearest position to the light emitting unit 50 that emits the green light LG.

[0065] like Figure 4As shown, the light receiving unit 51 includes: a light receiving element (first sensor unit) 510, which receives the green light LG; an angle limiting filter (first angle limiting filter) 511, which limits the incident angle of the green light LG reaching the light receiving element 510; and a bandpass filter 515, which selectively allows the green light LG to pass through.

[0066] The light receiving element 510 is composed of, for example, a photodiode (PD). The angle limiting filter 511 is provided on the light receiving surface 510a of the light receiving element 510. The angle limiting filter 511 is formed by embedding a plug 513 made of a light-shielding material such as tungsten in a light-transmitting silicon oxide layer 512.

[0067] Silicon oxide layer 512 forms an optical path that guides light to light-receiving surface 510a of light-receiving element 510. A plug 513 embedded in silicon oxide layer 512 limits the angle of incidence of light passing through the optical path (silicon oxide layer 512). Specifically, when light entering silicon oxide layer 512 is tilted at a predetermined angle relative to the optical path, the incident light strikes plug 513, partially absorbed by plug 513, and the remainder reflected. Furthermore, due to repeated reflections before passing through the optical path, the intensity of the reflected light decreases. Therefore, the light that ultimately passes through angle-limiting filter 511 is essentially limited to light whose tilt relative to the optical path is within the predetermined limit angle.

[0068] The angle-limiting filter 511 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 511 can limit the angle of incidence of light incident on the light-receiving element 510. Specifically, the angle-limiting filter 511 transmits green light LG incident at a predetermined angle of incidence (hereinafter referred to as the permitted angle of incidence) by propagating 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.

[0069] The bandpass filter 515 selectively transmits green light LG in the wavelength band and absorbs and blocks red light LR and near-infrared light LI in the other wavelength bands. The bandpass filter 515 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 511.

[0070] On the other hand, the light receiving unit 61 includes a light receiving element (second sensor unit) 610 that receives red light LR or near-infrared light LI, and an angle limiting filter (second angle limiting filter) 611 that limits the angle of incidence of the red light LR or near-infrared light LI reaching the light receiving element 610. Specifically, in the detection device 3 of this embodiment, the light receiving unit 61 has a different structure from the 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.

[0071] The light receiving element 610 is composed of, for example, a photodiode. An angle limiting filter 611 is provided on the light receiving surface 610a of the light receiving element 610. The angle limiting filter 611 has the same structure as the angle limiting filter 511 and is capable of limiting the angle of incidence of the red light LR or near-infrared light LI reaching the light receiving element 610. The angle limiting filter 611, for example, transmits the 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.

[0072] Figure 5 It 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.

[0073] like Figure 5 As shown, the transmittance when the wavelength band of green light LG (for example, 520nm) is incident on the skin is about 30%, the transmittance when the wavelength band of red light LR (for example, 660nm) is incident on the skin is about 45%, and the transmittance when the wavelength band of near-infrared light LI (for example, 905nm) is incident on the skin is about 60%.

[0074] 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.

[0075] Hereinafter, the operation of the detection device 3 according to this embodiment will be described.

[0076] The detection device 3 of this embodiment includes a light-emitting section 50 that emits green light LG; a light-emitting section 60 that emits red light LR having a wavelength higher than that of the green light LG; a light-emitting section 70 that emits near-infrared light LI having a wavelength higher than that of the green light LG; a light-receiving section 51 that receives the green light LG emitted from the light-emitting section 50 and emitted from the measurement site M; a light-receiving section 61 that receives the red light LR emitted from the light-emitting section 60 and emitted from the measurement site M; and a light-receiving section 61 that receives the near-infrared light LI emitted from the light-emitting section 70 and emitted from the measurement site M. The light-receiving section 51 includes a bandpass filter 515 that selectively transmits the green light LG. The distance D1 from the light-emitting section 50 to the light-receiving section 51 is shorter than the distance D2 from the light-emitting section 60 to the light-receiving section 61. In this embodiment, the distance D1 from the light-emitting section 50 to the light-receiving section 51 is shorter than the distance D3 from the light-emitting section 70 to the light-receiving section 61.

[0077] That is, in the detection device 3 of this embodiment, the light receiving unit 51 is arranged at the position closest to the light emitting unit 50 that emits the green light LG. When the light receiving unit 51 and the light emitting unit 50 are arranged close to each other, the green light LG emitted from the light emitting unit 50 travels a short distance in the body and enters the light receiving unit 51. Figure 5 As shown in the curve graph, the green light LG can only propagate a short distance in the biological body as described above. Therefore, if the distance between the light-emitting part 50 that emits the green light LG and the light-receiving part 51 that receives the green light LG is short, the green light LG emitted from the biological body can be incident on the light-receiving part 51 with a higher intensity.

[0078] In this embodiment, since the light receiving unit 51 is disposed closest to the light emitting unit 50, the amount of green light LG that propagates within the living body and enters the light receiving unit 51 can be maximized. Therefore, even when the amount of green light LG emitted by the light emitting unit 50 is suppressed, the detection device 3 can still sufficiently detect the green light LG that has propagated within the living body at the light receiving unit 51.

[0079] Therefore, the detection device 3 of this embodiment can detect the green light LG with high accuracy using the light receiving unit 51 while suppressing the emission amount of the green light LG emitted from the light emitting unit 50 to reduce the power consumption of the light emitting unit 11 .

[0080] Here, a portion of the red light LR and near-infrared light LI emitted from the light-emitting section 60 sometimes passes through the body and enters the light-receiving section 51. In this embodiment, the light-receiving section 51 includes a bandpass filter 515 that selectively transmits the green light LG. Therefore, the light-receiving section 51 can block the red light LR and near-infrared light LI, which have different wavelengths from the green light LG. Consequently, the light-receiving section 51 can efficiently receive the green light LG emitted from the light-emitting section 50.

[0081] Figure 6 It is a diagram for explaining the operation of the detection device 3.

[0082] like Figure 6 As shown, a portion of the green light LG emitted from the light-emitting unit 50 is reflected by, for example, the surface of the living body (measurement site M), and may enter the light-receiving unit 51 directly without passing through the living body. Furthermore, external light such as sunlight may enter the light-receiving unit 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 light-receiving unit 51 is referred to as the "first stray light component SL1," and the external light that directly enters the light-receiving unit 51 is referred to as the "second stray light component SL2."

[0083] Since the first stray light component SL1 has a green wavelength band, it passes through the bandpass filter 515 and is incident on the angle limiting filter 511 provided below the bandpass filter 515. As described above, the angle limiting filter 511 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.

[0084] Because the first stray light component SL1 enters the light receiving unit 51 without passing through the living body, the angle of incidence of the green light LG on the light receiving unit 51 is greater than the permissible angle of incidence of the angle limiting filter 511. In other words, the first stray light component SL1 is blocked by the angle limiting filter 511. Thus, the light receiving unit 51 can suppress the incidence of the first stray light component SL1 on the light receiving surface 510a of the light receiving element 510 through the angle limiting filter 511.

[0085] The second stray light component SL2 is substantially blocked by the bandpass filter 515, but the green-band component included in the second stray light component SL2 passes through the bandpass filter 515. 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 light receiving unit 51 is greater than the permissible angle of incidence of the angle limiting filter 511. Therefore, a portion of the second stray light component SL2 that passes through the bandpass filter 515 (the green-band component) is blocked by the angle limiting filter 511. Thus, the angle limiting filter 511 allows the light receiving unit 51 to suppress the second stray light component SL2 from entering the light receiving surface 510a of the light receiving element 510.

[0086] 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 510a of the light receiving element 510. 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 510a of the light receiving element 510.

[0087] Therefore, the light receiving unit 51 can achieve a high S / N ratio by suppressing the incidence of the first stray light component SL1 and the second stray light component SL2, which are noise sources. Therefore, the detection device 3 of this embodiment can accurately receive the green light LG in the light receiving unit 51. Therefore, by suppressing the amount of green light LG emitted by the light emitting unit 50, the power consumption of the light emitting unit 11 can be reduced.

[0088] Furthermore, in the detection device 3 of this embodiment, the distance (distance D2 or distance D3) between the light-emitting section 60 and the light-emitting section 70 and the light-receiving section 61 is greater than the distance D1 between the light-emitting section 50 and the light-receiving section 51. In other words, the distance that the red light LR and the near-infrared light LI propagate within the body before entering the light-receiving section 61 is greater than the distance that the green light LG propagates within the body before entering the light-receiving section 51.

[0089] like Figure 5 As shown, green light LG can only propagate a shorter distance within a living body than red light LR or near-infrared light LI. Therefore, even if green light LG propagates within the body to reach light receiving unit 61, the green light LG will be sufficiently attenuated while passing through the body. Consequently, the green light LG will not be incident on light receiving unit 61.

[0090] On the other hand, the red light LR and the near-infrared light LI can propagate farther within the body than the green light LG. Therefore, even if the red light LR and the near-infrared light LI propagate farther within the body than the green light LG, they can still enter the light receiving portion 61 farther away from the light emitting unit 11 with sufficient light intensity.

[0091] In this embodiment, since only red light LR and near-infrared light LI enter the light receiving unit 61, there is no need to provide the light receiving unit 61 with a bandpass filter that selectively transmits the red light LR and near-infrared light LI and blocks the green light LG. In other words, the detection device 3 of this embodiment can adopt the above-described structure in which only the light receiving unit 51 includes the bandpass filter 515, while the light receiving unit 61 does not include a bandpass filter. Therefore, the detection device 3 of this embodiment can achieve cost reduction by omitting the bandpass filter in the light receiving unit 61.

[0092] Furthermore, there are cases where a portion of the red light LR emitted from the light-emitting section 60 or a portion of the near-infrared light LI emitted from the light-emitting section 70 directly enters the light-receiving section 61 without passing through the living body. Furthermore, there are cases where external light such as sunlight directly enters the 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 enters the 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 enters the light-receiving section 61 will be referred to as the "fourth stray light component SL4."

[0093] Since the third stray light component SL3 does not pass through the living body but enters the angle limiting filter 611, the angle of incidence of the third stray light component SL3 with respect to the light receiving unit 61 is greater than the permissible angle of incidence of the angle limiting filter 611. 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 light receiving unit 61 is greater than the permissible angle of incidence of the angle limiting filter 611.

[0094] Therefore, the third and fourth stray light components SL3 and SL4 are well cut by the angle limiting filter 611. Thus, the light receiving unit 61 can suppress the third and fourth stray light components SL3 and SL4 from being incident on the light receiving surface 610a of the light receiving element 610 through the angle limiting filter 611.

[0095] 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 610a of the light-receiving element 610. 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 610a of the light-receiving element 610.

[0096] Therefore, the light receiving unit 61 can achieve a high S / N ratio by suppressing the incidence of the third stray light component SL3 and the fourth stray light component SL4, which are noise sources. According to the detection device 3 of this embodiment, since the red light LR and the near-infrared light LI are efficiently received by the light receiving unit 61, the light emission amount of each of the light emitting unit 60 and the light emitting unit 70 can be suppressed, thereby reducing the power consumption of the light emitting unit 11.

[0097] As described above, according to the detection device 3 of this embodiment, even when the light emission of the light-emitting units 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 that has passed through the living body with high accuracy. Furthermore, in the detection device 3 of this embodiment, by omitting the bandpass filter in the light-receiving unit 61, cost reduction can be achieved.

[0098] In addition, in the detection device 3 of this embodiment, as a countermeasure against stray light, there is no need to set a shading component between the light receiving part 51 and the light receiving part 61 as in the past, so there is no need for space for setting the shading component. By suppressing the enlargement of the detection device 3, the miniaturization of the device structure can be achieved.

[0099] (Second embodiment)

[0100] Next, the detection device of the second embodiment is described. In the first embodiment, the light receiving unit 61 receives both red light LR and near-infrared light LI. However, the detection device 3A of this embodiment differs from the detection device 3 of the first embodiment in that a light receiving unit is provided to receive both red light LR and near-infrared light LI.

[0101] Figure 7 It is a top view of the detection device of this embodiment. Figure 8 is based on Figure 7 Cross-sectional view along the VIII-VIII line arrow.

[0102] like Figure 7 as well as Figure 8 As shown, the light receiving unit 112 in the detection device 3A of this embodiment includes a light receiving section (first light receiving section) 151 , a light receiving section (second light receiving section) 161 , and a light receiving section (third light receiving section) 171 .

[0103] The light receiving unit 151 receives the green light LG emitted from the light emitting unit 50 and propagated inside the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0104] The light receiving unit 161 receives the near-infrared light LI emitted from the light emitting unit 70 and propagated inside the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0105] The light receiving unit 171 receives the red light LR emitted from the light emitting unit 60 and propagated inside the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0106] That is, in this embodiment, light emitting section 50 corresponds to the "first light emitting section," and the green light LG emitted from light emitting section 50 corresponds to the "first light." Furthermore, light emitting section 70 corresponds to the "second light emitting section," and the near-infrared light LI emitted from light emitting section 70 corresponds to the "second light." Furthermore, light emitting section 60 corresponds to the "third light emitting section," and the red light LR emitted from light emitting section 60 corresponds to the "third light."

[0107] The detection device 3A of this embodiment is different from the detection device 3 of the above embodiment in that two light receiving units (the light receiving unit 171 and the light receiving unit 161 ) receive the red light LR and the near-infrared light LI, respectively.

[0108] The light receiving unit 112 is disposed within the housing 40 such that the light receiving surfaces of the light receiving units 151, 171, and 161 are parallel to the XY plane. Specifically, the light receiving unit 151 is disposed on the +X side of the light emitting unit 112, the light receiving unit 171 is disposed on the +X side of the light receiving unit 151, and the light receiving unit 161 is disposed on the +X side of the light receiving unit 171. In other words, the light receiving unit 171 is disposed between the light receiving units 151 and 161.

[0109] In this embodiment, the distance from the light emitting unit 50 to the light receiving unit 151 is referred to as D4. The distance D4 corresponds to the distance between the center portions of the light emitting unit 50 and the light receiving unit 151 when viewed from the Z-axis direction.

[0110] Furthermore, let D5 be the distance from the light emitting unit 70 to the light receiving unit 161. The distance D5 corresponds to the distance between the center portions of the light emitting unit 70 and the light receiving unit 161 when viewed from the Z-axis direction.

[0111] Furthermore, let D6 be the distance from the light emitting unit 60 to the light receiving unit 171. The distance D6 corresponds to the distance between the center portions of the light emitting unit 60 and the light receiving unit 171 when viewed from the Z-axis direction.

[0112] In the detection device 3A of this embodiment, the distance D4 from the light emitting unit 50 to the light receiving unit 151 is shorter than the distance D5 from the light emitting unit 70 to the light receiving unit 161. Furthermore, the distance D4 from the light emitting unit 50 to the light receiving unit 151 is shorter than the distance D6 from the light emitting unit 60 to the light receiving unit 171. Furthermore, the distance D6 is shorter than the distance D5.

[0113] In the detection device 3A of this embodiment, similarly to the above-described embodiment, a light receiving unit 151 for receiving the green light LG is arranged at a position closest to the light emitting unit 50 that emits the green light LG.

[0114] The light receiving unit 151 has the same structure as the light receiving unit 51 of the above embodiment. Specifically, the light receiving unit 151 includes a light receiving element 510 for receiving green light LG, an angle limiting filter 511 , and a bandpass filter 515 .

[0115] In the detection device 3A of this embodiment, a light receiving unit 161 that receives near-infrared light LI is configured at a position farthest from the light emitting unit 11. The light receiving unit 161 has the same structure as the light receiving unit 61 of the above-described embodiment. The light receiving unit 161 includes a light receiving element (second sensor unit) 1610 that receives near-infrared light LI, and an angle limiting filter (second angle limiting filter) 1611 that limits the angle of incidence of near-infrared light LI reaching the light receiving element 1610.

[0116] Green light LG can only propagate a shorter distance in the body than red light LR or near infrared light LI. Therefore, green light LG does not reach the light receiving part 161. Figure 5 As shown, red light LR can propagate within a living body for a shorter distance than near-infrared light LI. Therefore, red light LR is fully attenuated within the body before reaching light receiving unit 161, resulting in a smaller amount of red light LR entering light receiving unit 161. Therefore, according to the detection device 3A of this embodiment, the bandpass filter that selectively transmits near-infrared light LI can be omitted from light receiving unit 161. Therefore, by omitting the bandpass filter from light receiving unit 161, the detection device 3A of this embodiment can achieve cost reduction.

[0117] Light receiving unit 171 has the same structure as light receiving unit 151. Specifically, light receiving unit 171 includes a light receiving element 1710 that receives red light LR; an angle limiting filter 1711 that limits the angle of incidence of red light LR on light receiving element 1710; and a bandpass filter 1715 that selectively transmits red light LR. Bandpass filter 1715 selectively transmits a wavelength range of red light LR, while absorbing and blocking green light LG and near-infrared light LI.

[0118] In the detection device 3A of this embodiment, the distance (distance D6) between the light emitting unit 60 that emits red light LR and the light receiving unit 171 that receives the red light LR is shorter than the distance (distance D5) between the light emitting unit 70 that emits near-infrared light LI and the light receiving unit 161 that receives the near-infrared light LI. Therefore, the green light LG propagating within the body may enter the light receiving unit 171 in an insufficiently attenuated state.

[0119] Furthermore, since near-infrared light LI can propagate within the body over a longer distance than green light LG, it is possible that near-infrared light LI can enter light receiving unit 171 with a higher intensity than green light LG. To address this issue, in this embodiment, light receiving unit 171 includes a bandpass filter 1715, enabling red light LR to efficiently enter light receiving element 1710.

[0120] According to the detection device 3A of this embodiment, stray light components are less likely to enter the light receiving section 151 , and the green light LG emitted from the light emitting unit 11 and passing through the living body can be efficiently entered into the light receiving section 151 .

[0121] Furthermore, according to the detection device 3A of this embodiment, stray light components are less likely to enter the light receiving portion 171, and red light LR emitted from the light emitting unit 11 and passing through the living body can be efficiently incident on the light receiving portion 171. Furthermore, stray light components are less likely to enter the light receiving portion 161, and near-infrared light LI emitted from the light emitting unit 11 and passing through the living body can be efficiently incident on the light receiving portion 161.

[0122] As described above, according to the detection device 3A of this embodiment, light can be efficiently received by each of the light receiving units 151, 161, and 171. Therefore, the amount of light emitted by the light emitting units 50, 60, and 70 can be suppressed, thereby reducing the power consumption of the light emitting unit 11. Furthermore, according to the detection device 3A of this embodiment, a light shielding member as a countermeasure against stray light is not required, thereby enabling a more compact device structure.

[0123] (Third embodiment)

[0124] Next, a measurement device 100B according to a third embodiment will be described. The measurement device 100B according to this embodiment differs from the measurement device 100 according to the first embodiment in that a detection device 3B is provided instead of the detection device 3 .

[0125] Figure 9 It is a side view of the measuring device 100B according to the third embodiment. Figure 9The measurement device 100B of the present embodiment shown is a biological measuring instrument that non-invasively measures biological information of a subject (eg, a human) as an example of a living body, and is worn on a measurement target site M (hereinafter referred to as a "measurement site") on the subject's body.

[0126] Figure 10 This is a structural diagram focusing on the functions of the measuring device 100B. Figure 10 As shown, the measuring device 100B of this embodiment includes a control device 5 , a storage device 6 , a display device 4 , and a detection device 3B.

[0127] The detection device 3B is an optical sensor module that generates a detection signal S corresponding to the state of the measurement site M. Figure 9 As shown, the detection device 3B is provided on, for example, a surface (hereinafter referred to as a detection surface) 16 of the housing 1 that faces the measurement site M. Figure 10 As shown, the detection device 3B of this embodiment includes a light-emitting unit 11, a light-receiving unit 12B, 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 3B. In other words, the drive circuit 13 and the output circuit 14 may be omitted from the detection device 3B.

[0128] In the detection device 3B of this embodiment, 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 to reach the light-receiving unit 12B. Specifically, the detection device 3B of this embodiment is a reflective optical sensor in which the light-emitting unit 11 and the light-receiving unit 12B are positioned to one side of the measurement site M.

[0129] The light receiving unit 12B receives light arriving from the measurement site M via the light emitting unit 11. The light receiving unit 12B of this embodiment includes a light receiving unit (first light receiving unit) 51B and a light receiving unit (second light receiving unit) 61. The light receiving units 51B and 61 generate detection signals corresponding to the intensity of the received light. Hereinafter, the light receiving units 51B and 61 will be collectively referred to as "light receiving units 51B and 61" unless otherwise specified.

[0130] The light receiving unit 51B receives the green light LG emitted from the 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 light receiving unit 61 receives the red light LR emitted from the light emitting unit 60 and propagated through the measurement site M, or the near-infrared light LI emitted from the light emitting unit 70 and propagated through the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0131] The output circuit 14 is configured to include, for example: an A / D converter that converts the detection signals generated by each light receiving unit 51B, 61 from analog to digital; and an amplifier circuit that amplifies the converted detection signals (both are omitted in the figure). The output circuit 14 generates multiple detection signals S (S1, S2, S3) corresponding to different wavelengths.

[0132] In this embodiment, detection signal S1 is a signal indicating the intensity of light received by light receiving unit 51B when receiving green light LG emitted from light emitting unit 50. Detection signal S2 is a signal indicating the intensity of light received by light receiving unit 61 when receiving red light LR emitted from light emitting unit 60. Detection signal S3 is a signal indicating the intensity of light received by light receiving unit 61 when receiving near-infrared light LI emitted from light emitting unit 70.

[0133] The drive circuit 13 and the output circuit 14 are mounted on a wiring board together with the light emitting unit 11 and the light receiving unit 12B in the form of IC chips.

[0134] The control device 5 is a calculation processing device such as a CPU (Central Processing Unit) or an FPGA (Field-Programmable Gate Array), and controls the entire measuring device 100B.

[0135] In the control device 5 of this embodiment, the program stored in the storage device 6 is also executed to determine the biological information of the measured person based on the multiple detection signals S (S1, S2, S3) generated by the detection device 3B. Specifically, the control device 5 determines the pulse of the measured person based on the detection signal S1 indicating the light intensity of the green light LG received by the light receiving unit 51B. The control device 5 can, for example, determine the pulse rate of the measured person based on the detection signal S1. In addition, the control device 5 can determine the oxygen saturation of the measured person by analyzing the detection signal S2 indicating the light intensity of the red light LR received by the light receiving unit 61 and the detection signal S3 indicating the light intensity of the near-infrared light LI received by the light receiving unit 61.

[0136] As described above, the control device 5 functions as an information analysis unit that determines biological information based on the detection signal S representing the detection results of the detection device 3B. The control device (information analysis unit) 5 causes the display device 4 to display the biological information determined based on the detection signal S. Furthermore, the measurement results can be notified to the user via audio output. A configuration is also preferred that warns the user (possibility of bodily dysfunction) if the pulse rate or oxygen saturation fluctuates outside a predetermined range.

[0137] Figure 11 It is a top view of the detection device 3B. Figure 12 is based on Figure 11 The cross-sectional view of the arrow line IX-IX in FIG. Figure 11 as well as Figure 12 As shown in FIG. 1 , the detection device 3B of this embodiment includes, in addition to the light emitting unit 11 and the light receiving unit 12B, a housing 40, a first light shielding wall 140, and a sealing layer 42. Figure 11 as well as Figure 12 In the figure, the driving circuit 13 and the output circuit 14 are omitted.

[0138] The following describes the structure of the detection device 3B 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.

[0139] like Figure 11 and Figure 12 As shown, the housing 40 is a component that houses the various elements (light-emitting unit 11 and light-receiving unit 12B) that make up the detection device 3B. The housing 40 has a box shape and includes a rectangular flat bottom portion 40a and a rectangular frame-shaped side plate portion 40b that protrudes from the periphery of the bottom portion 40a toward the +Z side.

[0140] The light-emitting unit 11 and the light-receiving unit 12B are arranged on the bottom portion 40a of the housing 40 in a state of being mounted on a wiring substrate (not shown). The first light-shielding wall 140 is arranged between the light-emitting unit 11 and the light-receiving unit 12B in the direction along the X-axis. The first light-shielding wall 140 is a 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. In other words, the first light-shielding wall 140 is a component that separates the space for storing the light-emitting unit 11 and the light-receiving unit 12B in the direction along the X-axis. The first light-shielding wall 140 is a light-shielding component that is used to shield light so that light emitted from the light-emitting unit 11 does not directly enter the light-receiving unit 12B.

[0141] In this embodiment, first light-shielding wall 140 is provided along the X-axis between light-emitting unit 11 (including light-emitting sections 50, 60, and 70) and light-receiving section 51B. In other words, first light-shielding wall 140 blocks a portion of green light LG, red light LR, and near-infrared light LI.

[0142] The sealing layer 42 is a translucent resin material that fills the gap between the light-emitting unit 11 and the light-receiving unit 12B housed within the housing 40 and the side plate 40b. In this embodiment, the sealing layer 42 seals the light-emitting units 50, 60, and 70 and the light-receiving units 51B and 61. The sealing layer 42 seals (moldes) the light-emitting unit 11 and the light-receiving unit 12B within the housing 40. The surface of the sealing layer 42 functions as the detection surface 16.

[0143] In this embodiment, the distal end 41a of the first light-shielding wall 140 protrudes from the surface (detection surface 16) of the sealing layer 42. The protrusion height of the distal end 41a of the first light-shielding wall 140 from the sealing layer 42 is set, for example, so that the distal end 41a abuts the measurement site M when the measurement device 100B is worn on the measurement site M of the person being measured.

[0144] Alternatively, instead of sealing with the sealing layer 42, a structure may be employed in which the upper surface of the side plate portion 40b of the housing 40 is covered with a light-transmitting substrate. In this case, the upper surface of the light-transmitting substrate functions as the detection surface 16. Furthermore, the distal end portion 41a of the first light-shielding wall 140 protrudes from the upper surface of the light-transmitting substrate.

[0145] The light emitting unit 11 is the same as that in the above embodiment, and therefore its description is omitted.

[0146] The light receiving unit 12B is provided in the housing 40 so that the light receiving surfaces of the light receiving parts 51B and 61 are parallel to the XY plane. That is, the light receiving parts 51B and 61 receive light incident from the Z direction.

[0147] like Figure 11 As shown, the light receiving sections 51B and 61 are spaced apart from each other and arranged in a direction (second direction) along the X-axis that intersects (is perpendicular to) the Y-axis. Specifically, the light receiving section 51B is arranged on the +X side of the light emitting unit 11, and the light receiving section 61 is arranged on the +X side of the light receiving section 51B. In other words, the light receiving section 61 is arranged on the opposite side of the light emitting unit 11 across the light receiving section 51B.

[0148] Here, the distance from the light-emitting section 50 to the light-receiving section 51B is D1, the distance from the light-emitting section 60 to the light-receiving section 61 is D2, and the distance from the light-emitting section 70 to the light-receiving section 61 is D3. Distance D1 corresponds to the distance between the centers of the light-emitting section 50 and the light-receiving section 51B when viewed from above in the Z-axis direction. Distance D2 corresponds to the distance between the centers of the light-emitting section 60 and the light-receiving section 61 when viewed from above in the Z-axis direction. Distance D3 corresponds to the distance between the centers of the light-emitting section 70 and the light-receiving section 61 when viewed from above in the Z-axis direction.

[0149] In the detection device 3B of this embodiment, the distance D1 from the light emitting unit 50 to the light receiving unit 51B is shorter than the distance D2 from the light emitting unit 60 to the light receiving unit 61. Furthermore, the distance D1 from the light emitting unit 50 to the light receiving unit 51B is shorter than the distance D3 from the light emitting unit 70 to the light receiving unit 61. Furthermore, the distance D2 and the distance D3 are equal.

[0150] As described above, in the detection device 3B of the present embodiment, a configuration is adopted in which the light receiving unit 51B for receiving the green light LG is arranged at the nearest position to the light emitting unit 50 that emits the green light LG.

[0151] like Figure 12 As shown, light receiving unit 51B includes a light receiving element 510 that receives green light LG, and a bandpass filter 515 disposed on light receiving element 510 to selectively transmit green light LG. In other words, detection device 3B of this embodiment includes bandpass filter 515 disposed on light receiving element 510 to selectively transmit green light LG.

[0152] The light receiving element 510 is composed of, for example, a photodiode (PD).

[0153] The bandpass filter 515 selectively transmits green light LG in the wavelength band and absorbs and blocks red light LR and near-infrared light LI in the other wavelength bands. The bandpass filter 515 is formed, for example, by alternately stacking multiple low-refractive-index layers such as silicon oxide and high-refractive-index layers such as titanium oxide on the light-receiving element 510.

[0154] On the other hand, the light receiving unit 61 includes a light receiving element 610 that receives red light LR or near-infrared light LI, and an angle limiting filter 611 that limits the angle of incidence of the red light LR or near-infrared light LI reaching the light receiving element 610. Specifically, the detection device 3B of this embodiment differs from the light receiving unit 51B in that the light receiving unit 61 includes the angle limiting filter 611, rather than a bandpass filter that selectively transmits the red light LR or near-infrared light LI.

[0155] The light receiving element 610 is formed of, for example, a photodiode. The angle limiting filter 611 is provided on the light receiving surface 610a of the light receiving element 610. The angle limiting filter 611 is formed by embedding a plug 613 made of a light-shielding material such as tungsten in a light-transmitting silicon oxide layer 612.

[0156] Silicon oxide layer 612 forms an optical path that guides light to light-receiving surface 610a of light-receiving element 610. Plug 613 embedded in silicon oxide layer 612 limits the angle of incidence of light passing through the optical path (silicon oxide layer 612). Specifically, when light entering silicon oxide layer 612 is tilted at a predetermined angle relative to the optical path, the incident light strikes plug 613, partially absorbed by plug 613, and the remainder reflected. Furthermore, due to repeated reflections before passing through the optical path, the intensity of the reflected light decreases. Therefore, the light that ultimately passes through angle-limiting filter 611 is essentially limited to light whose tilt relative to the optical path is within the predetermined limiting angle.

[0157] The angle limiting filter 611 has the following characteristics: it transmits light incident at an angle smaller than a predetermined incident angle, and blocks light incident at an angle greater than the predetermined incident angle. Here, the predetermined incident angle refers to the angle formed with respect to the normal to the light receiving surface 610a of the light receiving element 610.

[0158] Thus, the angle limiting filter 611 can limit the angle of incidence of light incident on the light receiving element 610. Specifically, the angle limiting filter 611 transmits red light LR and near-infrared light LI that propagate through the body and enter at a predetermined angle of incidence (hereinafter referred to as the permitted angle of incidence), while blocking light that enters at an angle larger than the permitted angle of incidence, such as external light such as sunlight or light that has not entered the body.

[0159] Next, the operation of the detection device 3B according to this embodiment will be described.

[0160] The detection device 3B of this embodiment includes: a light-emitting section 50 that emits green light LG; a light-emitting section 60 that emits red light LR having a wavelength higher than that of the green light LG; a light-emitting section 70 that emits near-infrared light LI having a wavelength higher than that of the green light LG; a light-receiving section 51B that receives the green light LG emitted from the light-emitting section 50 and emitted from the measurement site M; a light-receiving section 61 that receives the red light LR emitted from the light-emitting section 60 and emitted from the measurement site M and the near-infrared light LI emitted from the light-emitting section 70 and emitted from the measurement site M; and a bandpass filter 515 provided on the light-receiving element 510 of the light-receiving section 51B that selectively transmits the green light LG. The distance D1 from the light-emitting section 50 to the light-receiving section 51B is shorter than the distance D2 from the light-emitting section 60 to the light-receiving section 61. In this embodiment, the distance D1 from the light-emitting section 50 to the light-receiving section 51B is shorter than the distance D3 from the light-emitting section 70 to the light-receiving section 61.

[0161] That is, in the detection device 3B of this embodiment, the light receiving unit 51B is arranged at the position closest to the light emitting unit 50 that emits the green light LG. When the light receiving unit 51B and the light emitting unit 50 are arranged close to each other, the green light LG emitted from the light emitting unit 50 travels a short distance in the body and enters the light receiving unit 51B. Figure 5 As shown in the curve graph, the green light LG can only propagate a short distance in the biological body as described above. Therefore, if the distance between the light-emitting part 50 that emits the green light LG and the light-receiving part 51B that receives the green light LG is short, the green light LG emitted from the biological body can be incident on the light-receiving part 51B with a higher intensity.

[0162] In this embodiment, since light receiving unit 51B is positioned closest to light emitting unit 50, the amount of green light LG that propagates within the body and enters light receiving unit 51B can be maximized. Therefore, even when the amount of green light LG emitted by light emitting unit 50 is suppressed, detection device 3B can still sufficiently detect green light LG that has propagated within the body at light receiving unit 51B.

[0163] Therefore, the detection device 3B of this embodiment can detect the green light LG with high accuracy using the light receiving unit 51B while suppressing the emission amount of the green light LG emitted from the light emitting unit 50 to reduce the power consumption of the light emitting unit 11 .

[0164] Here, a portion of the red light LR and near-infrared light LI emitted from the light-emitting section 60 sometimes passes through the body and enters the light-receiving section 51B. In this embodiment, a bandpass filter 515 that selectively transmits green light LG is provided on the light-receiving element 510 of the light-receiving section 51B. Therefore, the light-receiving section 51B can block the red light LR and near-infrared light LI, which have wavelengths different from those of the green light LG. Consequently, the light-receiving section 51B can efficiently receive the green light LG emitted from the light-emitting section 50.

[0165] Furthermore, a portion of the green light LG emitted from the light emitting section 50 may be reflected by, for example, the surface of the living body (measurement site M), thereby directly entering the light receiving section 51B without passing through the living body. Furthermore, external light such as sunlight may directly enter the light receiving section 51B through the gap between the living body and the detection surface 16. Similarly, a portion of the red light LR emitted from the light emitting section 60 or a portion of the near-infrared light LI emitted from the light emitting section 70 may be reflected by the measurement site M, thereby directly entering the light receiving section 61 without passing through the living body.

[0166] Hereinafter, the green light LG that does not pass through the body but heads toward the light receiving unit 51B is referred to as “stray light component SL1 ”, and the red light LR or near-infrared light LI that does not pass through the body but heads toward the light receiving unit 61 is collectively referred to as “stray light component SL3 ”.

[0167] Figure 13 It is a diagram for explaining the operation of the detection device 3B.

[0168] like Figure 13 As shown, in the detection device 3B of this embodiment, the distal end 41a of the first light-shielding wall 140 protrudes beyond the detection surface 16, thereby contacting the measurement site M. This eliminates the gaps between the light-emitting unit 50 and the light-receiving unit 51B, and between the measurement site M and the detection surface 16. The stray light component SL1 and the stray light component SL3 are blocked by the distal end 41a. Therefore, the detection device 3B of this embodiment can suppress the stray light component SL1 from entering the light-receiving surface 510a of the light-receiving element 510 and the stray light component SL3 from entering the light-receiving unit 61.

[0169] Thus, in the detection device 3B of this embodiment, the green light LG emitted from the light emitting unit 11 and passing through the living body can be efficiently incident on the light receiving surface 510a of the light receiving element 510. Furthermore, in the detection device 3B of this embodiment, since the distal end 41a of the first light shielding wall 140 protruding from the detection surface 16 contacts the measurement site M, the incidence of the stray light component SL1 on the light receiving surface 510a of the light receiving element 510 and the incidence of the stray light component SL3 on the light receiving surface 510a of the light receiving element 510 can be suppressed.

[0170] Therefore, light receiving unit 51B can achieve a high S / N ratio by suppressing the incidence of stray light component SL1, which is a noise source. Therefore, detection device 3B of this embodiment can accurately receive green light LG in light receiving unit 51B. Therefore, by suppressing the amount of green light LG emitted by light emitting unit 50, power consumption of light emitting unit 11 can be reduced.

[0171] Furthermore, in the detection device 3B of this embodiment, the distance (distance D2 or distance D3) between the light-emitting unit 60 and the light-emitting unit 70 and the light-receiving unit 61 is greater than the distance D1 between the light-emitting unit 50 and the light-receiving unit 51B. In other words, the distance that the red light LR and the near-infrared light LI propagate within the body before entering the light-receiving unit 61 is greater than the distance that the green light LG propagates within the body before entering the light-receiving unit 51B.

[0172] like Figure 5As also shown in FIG, green light LG can only propagate a shorter distance within a living body than red light LR or near-infrared light LI. Therefore, assuming that green light LG propagates within the body to reach light receiving unit 61, the green light LG will be sufficiently attenuated while passing through the body. Consequently, the green light LG will not be incident on light receiving unit 61.

[0173] On the other hand, the red light LR and the near-infrared light LI can propagate farther within the body than the green light LG. Therefore, even if the red light LR and the near-infrared light LI propagate farther within the body than the green light LG, they can still enter the light receiving portion 61 farther away from the light emitting unit 11 with sufficient light intensity.

[0174] In this embodiment, since only red light LR and near-infrared light LI enter the light receiving unit 61, there is no need to provide a bandpass filter in the light receiving unit 61 that selectively transmits the red light LR and near-infrared light LI and blocks the green light LG. In other words, the detection device 3B of this embodiment can adopt the above-described structure in which only the light receiving unit 51B includes the bandpass filter 515, while the light receiving unit 61 does not include a bandpass filter. Therefore, the detection device 3B of this embodiment can achieve cost reduction by omitting the bandpass filter in the light receiving unit 61.

[0175] Furthermore, in the detection device 3B of this embodiment, the light receiving unit 61 is arranged closer to the side plate portion 40b of the housing 40 than the light receiving unit 51B. Therefore, external light such as sunlight may directly enter the light receiving unit 61 through the gap between the measurement site M and the detection surface 16. Hereinafter, the external light that directly enters the light receiving unit 61 is referred to as "stray light component SL4."

[0176] Since the stray light component SL4 enters the gap between the measurement site M and the detection surface 16, the angle of incidence of the stray light component SL4 with respect to the light receiving unit 61 is greater than the permissible angle of incidence of the angle limiting filter 611. Therefore, the stray light component SL4 is effectively blocked by the angle limiting filter 611. Thus, the light receiving unit 61 can suppress the stray light component SL4 from entering the light receiving surface 610a of the light receiving element 610 through the angle limiting filter 611.

[0177] In this manner, the detection device 3B of this embodiment allows the red light LR or near-infrared light LI emitted from the light-emitting unit 11 and passing through the living body to be efficiently incident on the light-receiving surface 610a of the light-receiving element 610. Furthermore, in the detection device 3B of this embodiment, since the angle-limiting filter 611 is provided on the light-receiving surface 610a of the light-receiving element 610, the incidence of the stray light component SL4 on the light-receiving surface 610a of the light-receiving element 610 can be suppressed.

[0178] According to the light receiving unit 61 of this embodiment, a high S / N ratio can be achieved by suppressing the incidence of stray light components SL3 and SL4, which can become noise sources. According to the detection device 3B of this embodiment, the red light LR and near-infrared light LI are efficiently received by the light receiving unit 61, thereby suppressing the amount of light emitted by the light emitting unit 60 and the light emitting unit 70, thereby reducing the power consumption of the light emitting unit 11.

[0179] As described above, according to the detection device 3B of this embodiment, even when the light emission of the light-emitting units 50, 60, and 70 is suppressed to achieve low power consumption of the light-emitting unit 11, the light-receiving unit 12B can still receive light that has passed through the living body with high precision. Furthermore, in the detection device 3B of this embodiment, by omitting the bandpass filter in the light-receiving unit 61, cost reduction can be achieved. Furthermore, in the detection device 3B of this embodiment, the angle-limiting filter 611, as required in the light-receiving unit 61, is not required, and the stray light component SL1 can be suppressed from entering the light-receiving unit 51B.

[0180] In addition, in the detection device 3B of this embodiment, as a countermeasure against stray light, there is no need to set a thick shading component between the light receiving portion 51B and the light receiving portion 61 as in the past, so there is no need for space for setting the shading component. By suppressing the enlargement of the detection device 3B, the miniaturization of the device structure can be achieved.

[0181] (First Modification)

[0182] Next, a first modification of the detection device will be described. This modification is a modification of the detection device 3B of the third embodiment. Hereinafter, the same reference numerals are assigned to common configurations and components with those of the third embodiment, and detailed reference numerals are omitted.

[0183] Figure 14 It is a cross-sectional view of the detection device of this modification.

[0184] like Figure 14 As shown, the detection device 3C of this modification includes the light-emitting unit 11, the light-receiving unit 12B, the housing 40, the first light-shielding wall 141, and the sealing layer 42. The distal end of the first light-shielding wall 141 of this modification is formed flush with the detection surface 16. That is, in this modification, the distal end of the first light-shielding wall 141 does not protrude from the detection surface 16.

[0185] In the X direction, the distance D12 from the first light-shielding wall 141 to the light-receiving portion 51B is longer than the distance D11 from the first light-shielding wall 141 to the light-emitting portion 50. That is, the light-receiving portion 51B is located farther from the first light-shielding wall 141 than the light-emitting portion 50. Furthermore, the light-emitting portion 60 and the light-emitting portion 70 are arranged side by side with the light-emitting portion 50 in the Y direction.

[0186] Here, if Figure 14 As shown in FIG. 1 , consider the path of green light LG1 emitted from the end surface 55a on the light receiving unit 51B side (+X side) of the light emitting surface 55 of the light emitting unit 50 and passing through the end 141b on the light emitting unit 50 side of the first light shielding wall 141. When this green light LG1 is regularly reflected by the surface of the living body (measurement site M), it reaches the position farthest from the first light shielding wall 141 in the X direction.

[0187] Assuming that the distance D12 from the first light-shielding wall 141 to the light-receiving portion 51B is the same as the distance D11 from the first light-shielding wall 141 to the light-emitting portion 50, the green light LG1 described above enters the light-receiving portion 51B as the stray light component SL1. Specifically, when the light-receiving portion 51B and the light-emitting portion 50 are arranged equidistantly on either side of the first light-shielding wall 141, the stray light component SL1 enters the light-receiving portion 51B.

[0188] In contrast, in the detection device 3C of this modified example, as described above, the light receiving unit 51B is arranged farther from the first light shielding wall 141 than the light emitting unit 50 , thereby suppressing the incidence of the stray light component SL1 (green light LG1 ) on the light receiving surface 510 a of the light receiving element 510 .

[0189] Therefore, according to the detection device 3C of this modification, by replacing the first light-shielding wall 140 of the third embodiment with a configuration in which the distance D12 from the first light-shielding wall 141 to the light-receiving portion 51B is longer than the distance D11 from the first light-shielding wall 141 to the light-emitting portion 50, it is possible to suppress the incidence of stray light component SL1, a noise source, on the light-receiving portion 51B without providing the angle-limiting filter 611 required for the light-receiving portion 61. Therefore, as in the third embodiment, by suppressing the amount of green light LG emitted by the light-emitting portion 50, it is possible to suppress power consumption of the light-emitting unit 11.

[0190] (Second Modification)

[0191] Next, a second modification of the detection device will be described. This modification is another modification of the detection device 3B of the third embodiment. Hereinafter, common configurations and components with the third embodiment and the first modification are denoted by the same reference numerals, and detailed reference numerals are omitted.

[0192] Figure 15 It is a cross-sectional view of the detection device of this modification.

[0193] like Figure 15 As shown, the detection device 3D of this modification includes the light emitting unit 11, the light receiving unit 12B, the housing 40, the first light shielding wall 141, and the sealing layer 42. The distal end of the first light shielding wall 141 is formed flush with the detection surface 16.

[0194] The light-emitting unit 50 of this modified example includes a lens (optical element) 56, which is disposed on the light-emitting surface 55 and deflects the emission direction of the green light LG toward the normal direction (Z direction) of the light-emitting surface 55. Furthermore, the light-emitting units 60 and 70 may or may not include a lens on the light-emitting surface. Furthermore, a diffraction element may be used as the optical element for deflecting the green light LG, instead of a lens.

[0195] Here, a description will be given of a case where the lens 56 is not provided. Normally, green light LG is emitted radially from the light-emitting surface 55 of the light-emitting unit 50. Therefore, if the lens 56 is not provided, green light LG2, which is a portion of the green light LG, may be reflected by the surface of the living body (measurement site M) and, as a result, may not pass through the living body but enter the light-receiving unit 51B as stray light component SL1.

[0196] In contrast, in the light emitting unit 50 of this modified example, the green light LG is emitted in the normal direction of the light emitting surface 55 by the lens 56. Therefore, the green light LG is incident perpendicularly to the measurement site M. Therefore, by suppressing the reflection of the green light LG2 on the surface of the measurement site M, the green light LG2 reflected from the surface of the measurement site M can be suppressed from being incident on the light receiving surface 510a of the light receiving element 510 as the stray light component SL1.

[0197] Therefore, according to the detection device 3D of this modification, by providing a lens 56 on the light-emitting surface 55 of the light-emitting unit 50 in place of the first light-shielding wall 140 of the third embodiment, it is possible to suppress the incidence of stray light component SL1, which is a noise source, on the light-receiving unit 51B without providing an angle-limiting filter 611 as is required in the light-receiving unit 61. Therefore, as in the third embodiment, by suppressing the amount of green light LG emitted by the light-emitting unit 50, it is possible to suppress the power consumption of the light-emitting unit 11.

[0198] (Fourth embodiment)

[0199] Next, the detection device of the fourth embodiment will be described. While the third embodiment and the aforementioned modifications illustrate the case where the light receiving unit 61 includes the angle limiting filter 611, the detection device of this embodiment differs in that the light receiving unit 261 does not include the angle limiting filter. Hereinafter, common structures and components with the aforementioned embodiments and modifications are denoted by the same reference numerals, and detailed reference numerals are omitted.

[0200] Figure 16 It is a cross-sectional view of the detection device according to this embodiment.

[0201] like Figure 16As shown, the detection device 3E of this embodiment includes the light emitting unit 11, the light receiving unit 212, the housing 40, the first light shielding wall 141, the sealing layer 42, and the second light shielding wall 143. The distal end of the first light shielding wall 141 is formed flush with the detection surface 16.

[0202] The light receiving unit 212 of this embodiment includes a light receiving unit (first light receiving unit) 251 and a light receiving unit (second light receiving unit) 261. Hereinafter, the light receiving unit 251 and the light receiving unit 261 are collectively referred to as "light receiving units 251, 261" unless otherwise specified.

[0203] The second light-shielding wall 143 is provided on the side of the light-receiving portion 261 opposite to the light-receiving portion 251 (the +X side). As described later, the second light-shielding wall 143 is a light-shielding component that blocks external light, such as sunlight, from directly entering the light-receiving unit 212 through the gap between the measurement portion M and the detection surface 16. In this embodiment, the second light-shielding wall 143 is formed by a portion of the side plate 40b of the housing 40 that is located on the side of the light-receiving portion 261 opposite to the light-receiving portion 251 (the +X side). Alternatively, the second light-shielding wall 143 may be formed by a component separate from the side plate 40b of the housing 40.

[0204] The light receiving unit 251 includes: a light receiving element 510, which receives the green light LG; an angle limiting filter 511, which is arranged on the light receiving element 510 and limits the incident angle of the green light LG reaching the light receiving element 510; and a bandpass filter 515, which is arranged on the angle limiting filter 511 and allows the green light LG to selectively pass through.

[0205] Angle limiting filter 511 has the same structure as angle limiting filter 611 and is capable of limiting the angle of incidence of green light LG reaching light receiving element 510. For example, angle limiting filter 511 transmits green light LG that propagates within the body and enters at an allowable angle of incidence, while blocking light that enters at an angle greater than the allowable angle of incidence, such as external light such as sunlight or green light LG that has not passed through the body.

[0206] On the other hand, light receiving unit 261 is composed only of a light receiving element 610 that receives red light LR or near-infrared light LI. That is, in the detection device 3E of this embodiment, light receiving unit 261 differs from the structure of light receiving unit 251 in that it does not include either an angle limiting filter or a bandpass filter.

[0207] like Figure 16As shown, a portion of the green light LG emitted from the light emitting unit 50 is reflected by, for example, the surface of the living body (measurement site M), and may not pass through the living body but directly enter the light receiving unit 251 as stray light component SL1. Furthermore, external light such as sunlight may directly enter the light receiving unit 251 through the gap between the living body and the detection surface 16. Hereinafter, external light that does not pass through the living body and travels toward the light receiving unit 251 is referred to as "stray light component SL1."

[0208] Since the stray light component SL1 has a green wavelength, it passes through the bandpass filter 515 and enters the angle limiting filter 511 provided below the bandpass filter 515. As described above, the angle limiting filter 511 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.

[0209] Since the stray light component SL1 does not pass through the living body but enters the light receiving unit 251, the angle of incidence of the green light LG with respect to the light receiving unit 251 is greater than the permissible angle of incidence of the angle limiting filter 511. In other words, the stray light component SL1 is blocked by the angle limiting filter 511. Thus, the light receiving unit 251 can suppress the stray light component SL1 from entering the light receiving surface 510a of the light receiving element 510 through the angle limiting filter 511.

[0210] The stray light component SL1 is largely blocked by the bandpass filter 515, but the green-band component included in the stray light component SL1 passes through the bandpass filter 515. As described above, the stray light component SL1 enters the gap between the living body and the detection surface 16, so the angle of incidence of the stray light component SL1 with respect to the light receiving unit 251 is greater than the permissible angle of incidence of the angle limiting filter 511. Therefore, a portion of the stray light component SL1 that passes through the bandpass filter 515 (the green-band component) is blocked by the angle limiting filter 511. Thus, the light receiving unit 251 can suppress the stray light component SL1 from entering the light receiving surface 510a of the light receiving element 510 through the angle limiting filter 511.

[0211] As described above, the detection device 3E of this embodiment can make it difficult for the stray light component SL1 to enter the light receiving surface 510a of the light receiving element 510. Therefore, the detection device 3E of this embodiment can receive the green light LG in the light receiving unit 251 with higher accuracy.

[0212] On the other hand, in the detection device 3E of this embodiment, the light receiving unit 261 is arranged closer to the side plate portion 40b (second light shielding wall 143) of the housing 40 than the light receiving unit 251. Therefore, a portion of the stray light component SL2 may also be directly incident on the light receiving unit 261 from the gap between the measurement site M and the detection surface 16.

[0213] In the detection device 3E of the present embodiment, by satisfying the design conditions described later, external light such as sunlight is suppressed from entering the light receiving unit 261 as a stray light component.

[0214] Figure 17 3 is a diagram showing conditions when the stray light component SL2 enters the light receiving unit 261 .

[0215] exist Figure 17 In the figure, the height from the light receiving surface 610a of the light receiving portion 261 (light receiving element 610) to the end of the second light shielding wall 143 is denoted as H, the width of the light receiving portion 261 in the X direction in which the light receiving portion 251 and the light receiving portion 261 are arranged is denoted as W, and the angle formed between the imaginary line LL connecting the end 261a of the light receiving surface 610a of the light receiving portion 261 on the light receiving portion 251 side and the upper end surface 143a of the second light shielding wall 143 on the light receiving portion 261 side and the light receiving surface 610a of the light receiving portion 261 is denoted as θ. Furthermore, the gap between the light receiving portion 261 and the second light shielding wall 143 is denoted as L.

[0216] like Figure 17 As shown, in the case where a portion of the stray light component SL2 that can barely enter the light receiving surface 610a of the light receiving portion 261 configured with a gap L set between the light receiving portion 261 and the second light shielding wall 143 is called a limit component, the limit component enters the light receiving surface 610a at an angle θ along the imaginary line LL.

[0217] exist Figure 17 In the case where the position of the light receiving portion 261 is shifted toward the +X side, the limit component of the stray light component SL2 cannot be incident on the light receiving surface 610a of the light receiving portion 261. Figure 16 In the detection device 3E of the illustrated embodiment, the gap L between the light receiving unit 261 and the second light shielding wall 143 is set to a value that satisfies the following formula.

[0218] [Formula 1]

[0219] L<H / tanθ-W

[0220] In addition, Figure 17 In the equation , if the incident angle θ1 of the imaginary line LL through which the limit component passes with respect to the light receiving surface 610a is defined as the angle with respect to the normal line of the light receiving surface 610a, it is defined by the following equation.

[0221] [Formula 2]

[0222]

[0223] According to the detection device 3E of this embodiment, Figure 17Compared to the state shown, the light receiving surface 610a of the light receiving unit 261 (light receiving element 610) is offset toward the +X side, thereby suppressing the incidence of the stray light component SL2 on the light receiving unit 261. According to the detection device 3E of this embodiment, the stray light component SL2 can be suppressed from entering the light receiving unit 261 without providing the angle limiting filter 511 as in the light receiving unit 251.

[0224] In this embodiment, the green light LG is attenuated, and only the red light LR and the near-infrared light LI enter the light receiving portion 261. Therefore, it is not necessary to provide a bandpass filter in the light receiving portion 261 that selectively transmits the red light LR and the near-infrared light LI and blocks the green light LG. In addition, by optimizing the position of the light receiving portion 261 relative to the second light-shielding wall 143 as described above, it is possible to suppress the incidence of stray light components on the light receiving portion 261 without using an angle-limiting filter.

[0225] Therefore, according to the detection device 3E of this embodiment, it is possible to adopt the above-described structure in which only the light receiving unit 251 includes the angle limiting filter 511 and the bandpass filter 515, while the light receiving unit 261 includes neither the angle limiting filter nor the bandpass filter. Therefore, the detection device 3E of this embodiment can achieve cost reduction by omitting the angle limiting filter and the bandpass filter in the light receiving unit 261.

[0226] (Fifth embodiment)

[0227] Next, the detection device of the fifth embodiment is described. While the third embodiment, the first variant, the second variant, and the fourth embodiment illustrate the use of a light receiving unit that simultaneously receives red light LR and near-infrared light LI, the detection device of this embodiment differs from the third embodiment in that a light receiving unit is provided that receives both red light LR and near-infrared light LI.

[0228] Figure 18 It is a top view of the detection device of this embodiment. Figure 19 is based on Figure 18 sectional view taken along line XII-XII in FIG. In addition, the same reference numerals are given to the same structures and components as those in the third embodiment, and detailed description thereof will be omitted.

[0229] like Figure 18 as well as Figure 19 As shown in FIG. 1 , the light receiving unit 112 in the detection device 3F of this embodiment includes a light receiving unit (first light receiving unit) 51F, a light receiving unit (second light receiving unit) 61F, and a light receiving unit (third light receiving unit) 71F. Figure 19 As shown, in the detection device 3F of this embodiment, the distal end portion 41 a of the first light shielding wall 140 also protrudes beyond the detection surface 16 .

[0230] The light receiving unit 51F receives the green light LG emitted from the light emitting unit 50 and propagated inside the measurement site M, and generates a detection signal corresponding to the intensity of the received light.

[0231] The light receiving unit 61F receives the near-infrared light LI emitted from the light emitting unit 70 and propagated inside the measurement site M, and generates a detection signal according to the intensity of the received light.

[0232] The light receiving unit 71F receives the red light LR emitted from the light emitting unit 60 and propagated inside the measurement site M, and generates a detection signal according to the intensity of the received light.

[0233] That is, in this embodiment, light emitting section 50 corresponds to the "first light emitting section," and the green light LG emitted from light emitting section 50 corresponds to the "first light." Furthermore, light emitting section 70 corresponds to the "second light emitting section," and the near-infrared light LI emitted from light emitting section 70 corresponds to the "second light." Furthermore, light emitting section 60 corresponds to the "third light emitting section," and the red light LR emitted from light emitting section 60 corresponds to the "third light."

[0234] The detection device 3F of this embodiment is different from the detection device 3B of the third embodiment in that the red light LR and the near-infrared light LI are received by two light receiving units (the light receiving unit 71F and the light receiving unit 61F), respectively.

[0235] The light receiving unit 112 is disposed within the housing 40 such that the light receiving surfaces of the light receiving units 51F, 71F, and 61F are parallel to the XY plane. Specifically, the light receiving unit 51F is disposed on the +X side of the light emitting unit 11, the light receiving unit 71F is disposed on the +X side of the light receiving unit 51F, and the light receiving unit 61F is disposed on the +X side of the light receiving unit 71F. In other words, the light receiving unit 71F is disposed between the light receiving units 51F and 61F.

[0236] In this embodiment, the distance from the light emitting unit 50 to the light receiving unit 51F is referred to as D4. The distance D4 corresponds to the distance between the center portions of the light emitting unit 50 and the light receiving unit 51F when viewed from the Z-axis direction.

[0237] Furthermore, the distance from the light emitting unit 70 to the light receiving unit 61F is referred to as D5. The distance D5 corresponds to the distance between the center portions of the light emitting unit 70 and the light receiving unit 61F when viewed from the Z-axis direction.

[0238] Furthermore, the distance from the light emitting unit 60 to the light receiving unit 71F is referred to as D6. The distance D6 corresponds to the distance between the center portions of the light emitting unit 60 and the light receiving unit 71F when viewed from above in the Z-axis direction.

[0239] In the detection device 3F of this embodiment, the distance D4 from the light emitting unit 50 to the light receiving unit 51F is shorter than the distance D5 from the light emitting unit 70 to the light receiving unit 61F. Furthermore, the distance D4 from the light emitting unit 50 to the light receiving unit 51F is shorter than the distance D6 from the light emitting unit 60 to the light receiving unit 71F. Furthermore, the distance D6 is shorter than the distance D5.

[0240] In the detection device 3F of this embodiment, similarly to the first embodiment, a light receiving unit 51F for receiving the green light LG is arranged at the nearest position to the light emitting unit 50 that emits the green light LG.

[0241] The light receiving unit 51F has the same structure as the light receiving unit 51B of the third embodiment. That is, the light receiving unit 51F includes a light receiving element 510 for receiving green light LG and a band pass filter 515 .

[0242] In the detection device 3F of this embodiment, a light receiving unit 61F that receives near-infrared light LI is located at a position farthest from the light emitting unit 11. The light receiving unit 61F has the same structure as the light receiving unit 61 of the third embodiment. The light receiving unit 61F includes a light receiving element 1610 that receives near-infrared light LI and an angle limiting filter 1611 that limits the angle of incidence of the near-infrared light LI that reaches the light receiving element 1610.

[0243] Green light LG can only propagate a shorter distance in the body than red light LR or near infrared light LI. Therefore, green light LG does not reach the light receiving part 61F. Figure 5 As shown, red light LR can propagate within a living body for a shorter distance than near-infrared light LI. Therefore, red light LR is fully attenuated within the living body before reaching light receiving unit 61F, resulting in a smaller amount of red light LR entering light receiving unit 61F. Therefore, according to the detection device 3F of this embodiment, the bandpass filter that selectively transmits near-infrared light LI can be omitted from light receiving unit 61F. Therefore, the detection device 3F of this embodiment can achieve cost reduction by omitting the bandpass filter from light receiving unit 61F.

[0244] The light receiving unit 71F has the same structure as the light receiving unit 51F. Specifically, the light receiving unit 71F includes a light receiving element 1710 that receives red light LR and a bandpass filter 1715 that selectively transmits red light LR. The bandpass filter 1715 selectively transmits red light LR within a certain wavelength range, while absorbing and blocking green light LG and near-infrared light LI. Furthermore, in this embodiment, the light receiving unit 71F may be provided with an angle limiting filter that limits the angle of incidence of red light LR reaching the light receiving element 1710.

[0245] In the detection device 3F of this embodiment, the distance (distance D6) between the light emitting unit 60 that emits red light LR and the light receiving unit 71F that receives the red light LR is shorter than the distance (distance D5) between the light emitting unit 70 that emits near-infrared light LI and the light receiving unit 61F that receives the near-infrared light LI. Therefore, the green light LG propagating within the body may enter the light receiving unit 71F in an insufficiently attenuated state.

[0246] Furthermore, since near-infrared light LI can propagate within the body over a longer distance than green light LG, it is possible that near-infrared light LI enters the light receiving unit 71F with a higher intensity than the green light LG. To address this issue, in this embodiment, the light receiving unit 71F includes a bandpass filter 1715, which allows the red light LR to efficiently enter the light receiving element 1710.

[0247] According to the detection device 3F of this embodiment, by making the terminal end 41a of the first light-shielding wall 140 protrude from the detection surface 16, it is difficult for stray light components to enter the light receiving part 51F, and the green light LG emitted from the light-emitting unit part 11 and passing through the biological body can be efficiently incident on the light receiving part 51F.

[0248] Furthermore, according to the detection device 3F of this embodiment, the distal end 41a of the first light-shielding wall 140 protrudes beyond the detection surface 16, thereby making it difficult for stray light components to enter the light receiving portion 71F, and allowing red light LR emitted from the light-emitting unit 11 and passing through the living body to efficiently enter the light receiving portion 71F. Furthermore, by providing the angle-limiting filter 1611, it is possible to make it difficult for stray light components to enter the light receiving portion 61F, and allowing near-infrared light LI emitted from the light-emitting unit 11 and passing through the living body to efficiently enter the light receiving portion 61F.

[0249] As described above, according to the detection device 3F of this embodiment, light can be efficiently received by each of the light receiving units 51F, 61F, and 71F, thereby reducing the amount of light emitted by the light emitting units 50, 60, and 70 and thereby reducing the power consumption of the light emitting unit 11. Furthermore, according to the detection device 3F of this embodiment, as a measure against stray light, a thick light shielding member is not required, thereby enabling a more compact device structure.

[0250] 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.

[0251] For example, in the above-described 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.

[0252] In the measurement devices 100 and 100B of the above embodiments, the detection devices 3 and 3B are installed in the case 1 as an example. However, the installation location of the detection devices 3 and 3B is not limited to this, and they may be embedded in the watch band 2, for example.

[0253] In addition, the measuring devices 100 and 100B of the above-mentioned embodiments are listed as watch-type structures, 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.

[0254] In addition, in the detection devices 3 and 3B of the above-mentioned first embodiment, 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, but since a light-receiving unit 61 corresponding to the green light LG of the light-emitting unit 50 is separately provided, the light-emitting unit 50 can also be made to light up all the time without being time-sharing.

[0255] Furthermore, the configuration of the first or second modified example can also be applied to the detection device 3F of the fifth embodiment. Furthermore, the configuration of the fifth embodiment can also be applied to the detection device 3E of the fourth embodiment. Specifically, the detection device 3E of the fourth embodiment can also be provided with light receiving units that receive the red light LR and the near-infrared light LI, respectively.

[0256] In the detection device 3B of the third embodiment, the angle limiting filter 611 of the light receiving unit 61 may be omitted. In this case, by applying the configuration of the fourth embodiment, it is possible to suppress stray light components from entering the light receiving unit 61 without providing the angle limiting filter 611.

[0257] The detection device according to one embodiment of the present invention may have the following structure.

[0258] 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 higher 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, the first light-receiving portion including a band-pass filter that selectively transmits the first light, and a distance from the first light-emitting portion to the first light-receiving portion is shorter than a distance from the second light-emitting portion to the second light-receiving portion.

[0259] 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, and the second light receiving unit may not include a bandpass filter that selectively transmits the second light.

[0260] In the detection device of one embodiment of the present invention, it can also be constructed that 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.

[0261] The detection device according to one embodiment of the present invention may further include a light-shielding wall provided between the first and second light-emitting sections and the first light-receiving section to shield a portion of the first and second lights.

[0262] In one embodiment of the present invention, the detection device can also be constructed to include: a first light-emitting portion, which emits a first light having a green band; a second light-emitting portion, which emits a second light having a band higher than the green band; a first light-receiving portion, which receives the first light emitted from the first light-emitting portion and emitted from the biological body; a second light-receiving portion, which receives the second light emitted from the second light-emitting portion and emitted from the biological body; and a bandpass filter, which is arranged on the light-receiving element of the first light-receiving portion, so that the first light is selectively transmitted, and the distance from the first light-emitting portion to the first light-receiving portion is shorter than the distance from the second light-emitting portion to the second light-receiving portion.

[0263] The detection device according to one embodiment of the present invention may further include a first light-shielding wall provided between the first and second light-emitting sections and the first light-receiving section to shield a portion of the first and second lights.

[0264] The detection device according to one embodiment of the present invention may further include a sealing layer that seals the first and second light-emitting sections and the first and second light-receiving sections, and the distal end of the first light-shielding wall may protrude from the sealing layer.

[0265] In the detection device according to one aspect of the present invention, a distance from the first light shielding wall to the first light receiving unit may be longer than a distance from the first light shielding wall to the first light emitting unit.

[0266] In the detection device according to one aspect of the present invention, the first light emitting unit may include an optical element provided on the light emitting surface to deflect the emission direction of the first light toward a normal direction of the light emitting surface.

[0267] Another embodiment of the detection device of the present invention comprises: a first light-emitting part, which emits a first light having a green band; a second light-emitting part, which emits a second light having a band higher than the green band; a first light-receiving part, which receives the first light emitted from the first light-emitting part and emitted from the biological body; a second light-receiving part, which receives the second light emitted from the second light-emitting part and emitted from the biological body; an angle-limiting filter, which is arranged on the light-receiving element of the first light-receiving part and limits the incident angle of the first light reaching the first light-receiving part; and a band-pass filter, which is arranged on the angle-limiting filter and selectively transmits the first light, the distance from the first light-emitting part to the first light-receiving part is shorter than the distance from the second light-emitting part to the second light-receiving part, and the second light-receiving part does not have an angle-limiting filter that limits the incident angle of the second light reaching the second light-receiving part, and a band-pass filter that selectively transmits the second light.

[0268] In the detection device according to another aspect of the present invention, a configuration may be further provided with a second light-shielding wall provided on the side of the second light-receiving portion opposite to the first light-receiving portion.

[0269] In another embodiment of the detection device of the present invention, the height from the light receiving surface of the second light receiving part to the end of the second light shading wall is set to H, the width of the second light receiving part in the direction in which the first light receiving part and the second light receiving part are arranged is set to W, and the angle formed by the imaginary line connecting the end of the light receiving surface of the second light receiving part on the side of the first light receiving part and the upper end surface of the second light shading wall on the side of the second light receiving part and the light receiving surface of the second light receiving part is set to θ. At this time, the gap L between the second light receiving part and the second light shading wall is set to a value that satisfies the following formula.

[0270] [Formula 1]

[0271] L<H / tanθ-W

[0272] In another aspect of the detection device of the present invention, the first light emitting unit and the second light emitting unit may be arranged side by side in a first direction, and the first light receiving unit and the second light receiving unit may be arranged side by side in a second direction intersecting the first direction.

[0273] In another embodiment of the detection device of the present invention, the detection device can also be constructed as follows: the detection device further has a third light-emitting portion that emits a third light, the second light-emitting portion emits light in one of the red band and the near-infrared band as the second light, the third light-emitting portion emits light in the other of the red band and the near-infrared band as the third light, the second light-receiving portion receives the third light and the second light emitted from the third light-emitting portion and emitted from the biological body, and the distance from the first light-emitting portion to the first light-receiving portion is shorter than the distance from the third light-emitting portion to the second light-receiving portion.

[0274] In another embodiment of the detection device of the present invention, it can also be constructed to further include: a third light-emitting unit, which emits a third light; and a third light-receiving unit, which receives the third light emitted from the third light-emitting unit and emitted from the biological body, the second light-emitting unit emits light of one band between the red band and the near-infrared band as the second light, and the third light-emitting unit emits light of the other band between the red band and the near-infrared band as the third light, and the distance from the first light-emitting unit to the first light-receiving unit is shorter than the distance from the third light-emitting unit to the third light-receiving unit.

[0275] In the detection device according to another aspect of the present invention, the first light emitting section may be arranged between the second light emitting section and the third light emitting section in the first direction.

[0276] The measuring device according to one embodiment of the present invention may have the following configuration.

[0277] 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 configured to emit a second light having a wavelength higher 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 portion for receiving the second light emitted from the second light emitting portion and emitted from the biological body; The first light receiving unit includes: a first sensor unit that receives the first light; a first angle limiting filter that limits the incident angle of the first light reaching the first sensor unit; and a bandpass filter that selectively transmits the first light. The first angle limiting filter is provided between the first sensor unit and the band pass filter. The second light receiving unit includes: a second sensor unit that receives the second light; and a second angle limiting filter that limits the incident angle of the second light reaching the second sensor unit. The second light receiving unit does not include a bandpass filter for selectively transmitting the second light. The distance from the first light emitting unit to the first light receiving unit is shorter than the distance from the second light emitting unit to the second light receiving unit. The distance from the second light emitting unit to the second light receiving unit is longer than the distance that the first light can propagate in the living body. The second angle limiting filter has the same structure as the first angle limiting filter.

2. The detection device according to claim 1, wherein The detection device further includes a light shielding wall provided between the first light emitting section, the second light emitting section, and the first light receiving section, and shielding a portion of the first light and the second light.

3. The detection device according to claim 1, wherein: The detection device further comprises a third light emitting portion that emits a third light. The second light emitting portion emits light in one of a red wavelength band and a near infrared wavelength band as the second light. The third light emitting portion emits light in the other wavelength band of the red wavelength band and the near infrared wavelength band as the third light. The second light receiving unit receives the third light and the second light emitted from the third light emitting unit and emitted from the living body. A distance from the first light emitting section to the first light receiving section is shorter than a distance from the third light emitting section to the second light receiving section.

4. The detection device according to claim 1, wherein: The detection device also has: a third light emitting portion that emits a third light; and a third light receiving unit for receiving the third light emitted from the third light emitting unit and emitted from the living body; The second light emitting portion emits light in one of a red wavelength band and a near infrared wavelength band as the second light. The third light emitting portion emits light in the other wavelength band of the red wavelength band and the near infrared wavelength band as the third light. A distance from the first light emitting section to the first light receiving section is shorter than a distance from the third light emitting section to the third light receiving section.

5. The detection device according to claim 3 or 4, wherein: The first light emitting portion and the second light emitting portion are arranged in a first direction, The first light receiving section and the second light receiving section are arranged side by side in a second direction intersecting the first direction.

6. The detection device according to claim 5, wherein: The first light emitting portion is arranged between the second light emitting portion and the third light emitting portion in the first direction.

7. The detection device according to claim 2, wherein: The detection device further includes a sealing layer, which seals the first light emitting unit, the second light emitting unit, and the first light receiving unit and the second light receiving unit. A distal end portion of the light shielding wall protrudes from the sealing layer.

8. The detection device according to claim 2 or 7, wherein: A distance from the light shielding wall to the first light receiving portion is longer than a distance from the light shielding wall to the first light emitting portion.

9. The detection device according to claim 1, wherein: The first light emitting portion includes an optical element, and the optical element is provided on a light emitting surface to deflect a light emitting direction of the first light toward a normal direction of the light emitting surface.

10. 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 configured to emit a second light having a wavelength higher than the green wavelength; a first light receiving portion for receiving the first light emitted from the first light emitting portion and emitted from the living body; a second light receiving portion for receiving the second light emitted from the second light emitting portion and emitted from the living body; an angle limiting filter provided on the light receiving element of the first light receiving portion and limiting the incident angle of the first light reaching the first light receiving portion; and a bandpass filter provided on the angle limiting filter to selectively transmit the first light; The distance from the first light emitting unit to the first light receiving unit is shorter than the distance from the second light emitting unit to the second light receiving unit. The second light receiving unit does not include an angle limiting filter for limiting the incident angle of the second light reaching the second light receiving unit and a band pass filter for selectively transmitting the second light. The detection device further comprises a second light shielding wall provided on a side of the second light receiving portion opposite to the first light receiving portion. The height from the light receiving surface of the second light receiving portion to the end of the second light shielding wall is defined as H. The width of the second light receiving portion in the direction in which the first light receiving portion and the second light receiving portion are arranged is set to W. The angle formed by an imaginary line connecting the end portion of the light receiving surface of the second light receiving portion on the side of the first light receiving portion and the upper end surface of the second light shielding wall on the side of the second light receiving portion and the light receiving surface of the second light receiving portion is θ, At this time, the gap L between the second light receiving portion and the second light shielding wall is set to a value that satisfies the following equation: [Equation 1] L <H / tanθ-W。 11. A measuring device, wherein: The measuring device has: The detection device according to any one of claims 1 to 10; 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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