Biological detection device

Abstract

To miniaturize the device. [Solution] The biological detection device 100 includes a light-emitting unit 10 that emits a first light L1, a light-receiving unit 30 that receives a second light L2 which is the first light L1 reflected by the biological body OB to be detected, and a transmission-reflection unit 20 into which the first light L1 is incident, reflecting a portion of the first light L1 toward the biological body OB to be detected, and into which the second light L2 is incident, transmitting a portion of the second light L2. The second light L2 that has passed through the transmission-reflection unit 20 is incident on the light-receiving unit 30.

Description

Technical Field

[0001] The present invention relates to a biological detection device that optically detects biological information.

Background Art

[0002] There is a known self-luminous sensor device that includes an irradiation unit that irradiates a plurality of lights with different wavelengths onto a subject so as to be at least partially overlapped with each other, and a light receiving unit that detects light from the subject caused by the irradiated plurality of lights for each wavelength (Patent Document 1). Here, the irradiation unit is, for example, a laser diode having a plurality of wavelengths, and emission points are arranged side by side in a vertical direction corresponding to the thickness of a substrate on a substrate extending in a direction substantially orthogonal to the light emission direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above device, since it is a so-called end-face light-emitting type irradiation unit, when making it multicolor, it is necessary to stack the emission points, and further miniaturization cannot be achieved.

Means for Solving the Problems

[0005] A biological detection device according to one aspect of the present invention includes a light emitting unit that emits a first light, a light receiving unit that receives a second light reflected by a biological body to be detected by the first light, and a transmission reflection unit that allows the first light to enter, reflects a part of the first light toward the biological body to be detected, allows the second light to enter, and transmits a part of the second light. The second light transmitted through the transmission reflection unit enters the light receiving unit.

[0006] One aspect of the present invention is a biological detection device comprising: a light-emitting unit that emits a first light; a light-receiving unit that receives a second light which is the first light reflected by the biological body to be detected; and a transmission-reflection unit into which the first light is incident, a portion of the first light is transmitted toward the biological body to be detected, and the second light is incident, a portion of the second light is reflected, and the second light reflected by the transmission-reflection unit is incident on the light-receiving unit. [Brief explanation of the drawing]

[0007] [Figure 1] This is a conceptual lateral cross-sectional view illustrating the biodetection device of the first embodiment. [Figure 2] This is a conceptual AA cross-sectional view illustrating a biodetection device. [Figure 3] This is a conceptual lateral cross-sectional view illustrating a modified example of the biodetector shown in Figure 1. [Figure 4] This is a conceptual lateral cross-sectional view illustrating a biological information measurement device. [Figure 5] This is a conceptual lateral cross-sectional view illustrating a biodetection device according to a second embodiment. [Figure 6] This is a conceptual BB cross-sectional view illustrating a biodetection device. [Figure 7] This is a conceptual lateral cross-sectional view illustrating a biodetection device according to a third embodiment. [Figure 8] This is a conceptual cross-sectional view of a biodetection device. [Figure 9] This is a conceptual lateral cross-sectional view illustrating a biodetection device according to the fourth embodiment. [Figure 10] This is a conceptual DD cross-sectional view illustrating a biodetection device. [Figure 11] This is a conceptual lateral cross-sectional view illustrating a biodetection device according to the fifth embodiment. [Figure 12] This is a conceptual EE cross-sectional view illustrating a biodetection device. [Figure 13] This is a conceptual cross-sectional view illustrating a modified example of the biodetector shown in Figure 11. [Figure 14] This is a conceptual lateral cross-sectional view illustrating the biodetection device of the sixth embodiment. [Figure 15]It is a conceptual F-F cross-sectional view for explaining a biological detection device. [Figure 16] It is a conceptual side cross-sectional view for explaining a modification example of the biological detection device of FIG. 14. [Figure 17] It is a conceptual G-G cross-sectional view for explaining the biological detection device of FIG. 16. [Figure 18] It is a conceptual side cross-sectional view for explaining another modification example of the biological detection device of FIG. 14. [Figure 19] It is a conceptual side cross-sectional view for explaining yet another modification example of the biological detection device of FIG. 14.

Embodiments for Carrying Out the Invention

[0008] 〔First Embodiment〕 Hereinafter, referring to the drawings, the biological detection device according to the first embodiment of the present invention will be described.

[0009] FIG. 1 is a conceptual side cross-sectional view for explaining a biological detection device 100. FIG. 2 is a conceptual A-A cross-sectional view for explaining the biological detection device 100.

[0010] The biological detection device 100 shown in FIGS. 1 and 2 is a device that detects biological information of a biological object OB to be detected by optical and non-invasive methods. Examples of the biological object OB to be detected include a human, an animal, etc. Examples of the biological information include a pulse, blood oxygen saturation (blood oxygen concentration), etc. The biological detection device 100 is, for example, a PPG (Photoplethysmography) sensor and is incorporated into vital devices and the like.

[0011] In the following embodiments, a biological detection device 100 for detecting human biological information will be described. The biological detection device 100 is pressed against a person's skin and emits a first light L1, which is light in a predetermined wavelength band, toward the skin. The biological detection device 100 receives a second light L2, which is the reflected light of the first light L1 on the skin, and detects a pulse, blood oxygen saturation, etc. based on the temporal change in the amount of received second light L2. Here, substances that reflect the first light L1 in the human body are, for example, hemoglobin in capillaries, etc.

[0012] As shown in FIGS. 1 and 2, the biological detection device 100 generally has a substantially hexahedral outer shape. The biological detection device 100 includes a first substrate BK1, a second substrate BK2, a light emitting unit 10, a transmission and reflection unit 20, a light receiving unit 30, and a light absorption layer 40. The biological detection device 100 also includes a circuit board W that operates the light emitting unit 10 and the light receiving unit 30 as a part incorporated in the first substrate BK1 or the second substrate BK2. The biological detection device 100 may or may not be housed in a housing member 50 having an opening OP. Further, a window (not shown) may be provided in the opening OP.

[0013] The first substrate BK1 is a plate-like member extending in a first direction D1 in a side cross-sectional view parallel to the light transmission and reception direction. The second substrate BK2 is a plate-like member extending in a second direction D2 intersecting the first direction D1 in a similar side cross-sectional view. In the present embodiment, the first direction Dl is the Y direction corresponding to the left-right direction on the paper surface of FIG. 1. Also, the second direction D2 is the Z direction corresponding to the up-down direction on the paper surface of FIG. 1. In the illustrated example, the second substrate BK2 extends vertically from one end B1 of the first substrate BK1 in the first direction D1. By intersecting the first substrate BK1 and the second substrate BK2, the light emitting unit 10 and the light receiving unit 30 can be efficiently arranged. The first substrate BK1 and the second substrate BK2 are formed of a material having low thermal conductivity and light shielding properties.

[0014] The light-emitting unit 10 is provided on the second substrate BK2. The light-receiving unit 30 is provided on the first substrate BK1. The transmission and reflection unit 20 is provided at an inclined position where the first light L1 incident from the light-emitting unit 10 and the second light L2 incident on the light-receiving unit 30 intersect.

[0015] In the biodetector 100, the internal space other than the first substrate BK1, the second substrate BK2, the light-emitting section 10, the transmission and reflection section 20, the light-receiving section 30, and the light-absorbing layer 40 is provided with a light-transmitting member LL. The transmission and reflection section 20 is surrounded by the light-transmitting member LL in an inclined state. The light-emitting section 10 and the light-receiving section 30 are arranged to be embedded outside the light-transmitting member LL. The first substrate BK1, the second substrate BK2, and the light-absorbing layer 40 are arranged to cover the outside of the light-transmitting member LL.

[0016] The light-emitting unit 10 emits a first light L1. The first light L1 emitted from the light-emitting unit 10 is incident on the transmission / reflection unit 20. The light-emitting unit 10 has a surface-emitting (surface-emitting) light-emitting element 10a. This eliminates the need to stack multiple wavelengths even if the light-emitting unit 10 is multi-colored, allowing for miniaturization of the light-emitting unit 10. The light-emitting unit 10 is positioned in the first direction D1 of the transmission / reflection unit 20, specifically in the +Y direction or to the right side of the paper in Figure 1.

[0017] The light-emitting unit 10 has one or more light-emitting units 11 to 13. In the illustrated example, the light-emitting unit 10 has three light-emitting units 11 to 13. The light-emitting units 11 to 13 are arranged in the same direction, specifically in the X direction. Specifically, the light-emitting unit 10 has a first light-emitting unit 11 that emits light in the first wavelength band, a second light-emitting unit 12 that emits light in the second wavelength band, and a third light-emitting unit 13 that emits light in the third wavelength band. By controlling the driving of each light-emitting unit 11 to 13, multiple pieces of biological information can be detected. The first wavelength band is, for example, the green wavelength band and is used for pulse rate measurement. The green wavelength band is, for example, 500 nm to 570 nm, preferably 520 nm. The second wavelength band is, for example, the red wavelength band and is used for blood oxygen saturation measurement. The red wavelength band is, for example, 630 nm to 680 nm, preferably 660 nm. The third wavelength band is, for example, the infrared wavelength band, and is used for measuring blood oxygen saturation. The infrared wavelength band is, for example, 850 nm to 1000 nm, preferably 905 nm.

[0018] Examples of light-emitting units 10 include LEDs (light-emitting diodes), OLEDs (organic light-emitting diodes), micro-LEDs, and VCSELs (Vertical Cavity Surface Emitting Lasers).

[0019] The transmission-reflecting section 20 receives the first light L1 from the light-emitting section 10, reflects a portion of the first light L1 toward the biological tissue OB to be detected, and receives the second light L2 from the biological tissue OB to be detected, transmitting a portion of the second light L2. The second light L2 that has passed through the transmission-reflecting section 20 is incident on the light-receiving section 30. In the transmission-reflecting section 20, the transmittance or reflectance of the first light L1 is, for example, 50%. That is, the transmission-reflecting section 20 transmits 50% of the first light L1 and reflects 50%. The transmittance or reflectance of the second light L2 is, for example, 50%. That is, the transmission-reflecting section 20 transmits 50% of the second light L2 and reflects 50%. The reflectance of the first light L1 and the transmittance of the second light L2 can be changed as appropriate.

[0020] The transmission-reflecting section 20 is positioned at an angle with respect to the emission direction of the light-emitting section 10 so as to irradiate the first light L1 toward the biological tissue OB to be detected. The inclination angle of the transmission-reflecting section 20 is, for example, 45°. The inclination angle of the transmission-reflecting section 20 can be changed as appropriate. The transmission-reflecting section 20 is, for example, a film-like, plate-like member and is formed on the inclined surface Ks of the light-transmitting member LL, which will be described later and is provided below the transmission-reflecting section 20. The transmission-reflecting section 20 is made of, for example, a material with about 50% transmittance, and is specifically made of a metal thin film, a cell-cast acrylic plate, a semi-transparent liquid crystal panel, etc. The transmission-reflecting section 20 is manufactured by methods such as photolithography, electron beam lithography, nanoimprint, etc.

[0021] Furthermore, the light-transmitting member LL on the lower side of the light-transmitting member 20 may be replaced with a triangular prism-shaped member having an inclined surface Ks. In this case, the material of the light-transmitting member 20 may be a material having about 50% transparency, specifically polycarbonate, acrylic, and polyester.

[0022] The light-receiving unit 30 receives the second light L2, which is the first light L1 reflected by the biological object OB to be detected. In this embodiment, the light-receiving unit 30 is positioned in the second direction D2 of the transmission / reflection unit 20, specifically in the -Z direction or on the lower side of the paper in Figure 1.

[0023] The light-receiving unit 30 corresponds to the wavelength band of the first light L1 emitted from the light-emitting unit 10. Specifically, the light-receiving unit 30 detects light in the first wavelength band, light in the second wavelength band, and light in the third wavelength band.

[0024] The light-receiving unit 30 may be, for example, a photodiode.

[0025] The light-absorbing layer 40 is positioned on the opposite side of the light-emitting unit 10, with the transmission-reflecting unit 20 in between. The light-absorbing layer 40 absorbs the first light L1 that has passed through the transmission-reflecting unit 20. The light-absorbing layer 40 prevents the first light L1 emitted from the light-emitting unit 10 and passed through the transmission-reflecting unit 20 from directly entering the light-receiving unit 30. This suppresses noise. The light-absorbing layer 40 is formed of, for example, a black resin material, has low thermal conductivity, and has light-shielding properties.

[0026] The light-transmitting member LL is made of resin, glass, or the like. The light-transmitting member LL efficiently transmits the first light L1 and the second light L2.

[0027] The circuit board W is mounted on, for example, the first board BK1. In addition to the light-receiving unit 30, the circuit board W has a light-emitting unit 10 and a drive circuit P that operates the light-receiving unit 30. The drive circuit P outputs information regarding the optical response of the biological body OB to be detected, specifically information such as pulse rate and blood oxygen saturation, to the control circuit device 202 of the biological information measurement device 200, which will be described later and incorporates, for example, the biological detection device 100 (see Figure 4). The circuit board W may be mounted on the second board BK2, on both the first board BK1 and the second board BK2, or it may be a separate component from the first board BK1 and the second board BK2.

[0028] In the biological detection device 100, the member that comes into contact with the biological organism OB to be detected has insulating properties to prevent electrical conductivity. In this embodiment, the member that comes into contact with the biological organism OB to be detected is a light-transmitting member LL that is exposed on the side of the opening 101 of the biological detection device 100 or the opening OP of the housing member 50.

[0029] The following describes an example of a method for manufacturing the biological detection device 100. The biological detection device 100 is manufactured by, for example, dividing it into three blocks BC1 to BC3, manufacturing each block BC1 to BC3, and then joining and assembling these blocks BC1 to BC3. Specifically, the biological detection device 100 consists of a first block BC1 including a light-emitting unit 10 and a second substrate BK2, a second block BC2 including a transmission / reflection unit 20 and a light-absorbing layer 40, and a third block BC3 including a light-receiving unit 30 and a first substrate BK1. The components included in each block BC1 to BC3 can be changed as appropriate. The shape of each block BC1 to BC3 and the number of blocks can also be changed as appropriate.

[0030] As shown in Figure 3, in the first block BC1, the entire structure may be covered with a light-transmitting member LL without exposing the second substrate BK2, and the lengths of the second block BC2 and the third block BC3 in the Y direction may be made equal.

[0031] The light-transmitting members LL included in each block BC1 to BC3 are formed, for example, by molding using a mold. It is desirable that the light-transmitting members LL included in each block BC1 to BC3 be formed from the same material.

[0032] The optical path of the biological detection device 100 will be described below. As shown in Figure 1, the light-emitting unit 10 emits a first light, L1 which is the irradiation light DL, towards the biological body OB to be detected through the aperture 101 or aperture OP. Approximately 50% of the first light L1 emitted from the light-emitting unit 10 is reflected by the transmission-reflection unit 20 and incident on the biological body OB to be detected. The remaining 50% of the first light L1 passes through the transmission-reflection unit 20 and is absorbed by the light-absorbing layer 40. The first light L1 incident on the biological body OB to be detected is reflected by the biological body OB to become the second light L2.

[0033] The second light L2 reflected from the biological object OB being detected is transmitted through the transmission / reflection unit 20 by about 50% and received by the light receiving unit 30. The light receiving unit 30 receives the second light L2, which is the reflected light SL that has returned from the biological object OB being detected, through the aperture 101 or aperture OP, and outputs a signal corresponding to the intensity of the second light L2.

[0034] The following describes an example of the operation of the biodetector 100. When the biodetector 100 has two or more light-emitting units 10, the drive circuit P drives the light-emitting units 10, specifically, the light-emitting units 11 to 13, separately. The drive circuit P acquires a signal from the light-receiving unit 30 in synchronization with the separate driving of the light-emitting units 10. For example, when measuring pulse rate, the biodetector 100 drives only the first light-emitting unit 11 of the first wavelength (green) and receives the light with the light-receiving unit 30. Also, when measuring blood oxygen saturation, the biodetector 100 drives the second light-emitting unit 12 of the second wavelength (red) and the third light-emitting unit 13 of the third wavelength (infrared) and receives the light with the light-receiving unit 30. This prevents the first light L1 from different light-emitting units 10 from becoming noise. Furthermore, by driving each of the light-emitting units 11 to 13, power consumption can be reduced.

[0035] The following describes examples of vital signs devices into which the biometric detection device 100 is incorporated. Examples of vital signs devices worn on the body include smartwatches, activity trackers, smart rings, and pulse oximeters. Examples of vital signs devices attached to objects that people touch include wireless mice, door handle sensors, and car steering wheel sensors.

[0036] Figure 4 is a conceptual lateral cross-sectional view illustrating an example of a biological information measurement device 200 incorporating a biological detection device 100.

[0037] The biometric information measuring device 200 is a wearable device, has the appearance of a wristwatch, and can be attached to the arm, which is part of the human body, i.e., the biological HB. The biometric information measuring device 200 comprises a main unit 200a and a pair of wristbands 200b attached to the main unit 200a and extending in opposite directions. Here, the main unit 200a includes a biometric detection device 100, a main board 201, a control circuit device 202, a battery 203, a display 204, and a case 205.

[0038] The main circuit board 201 supports the biological detection device 100 on the side of the biological organism OB to be detected. The main circuit board 201 also supports the control circuit device 202 and the battery 203 on the opposite side of the biological detection device 100.

[0039] The biological detection device 100 is located inside the case 205 and is covered by a light-transmitting plate-shaped window member 205i fixed to the opening 205p. In the illustrated example, the window member 205i is slightly curved so as to be convex toward the biological body OB to be detected.

[0040] The control circuit 202 is an arithmetic processing circuit including a microprocessor, which operates the biological detection device 100 and measures biological information based on the detected value of the light receiving unit 30. The control circuit 202 and the circuit board W together are called the control unit CT. The control circuit 202 may also be integrated into the circuit board W. The control circuit 202 or the control unit CT acquires biological information such as the pulse rate and blood oxygen saturation of the biological body OB to be detected based on the second light L2 received by the light receiving unit 30, for example. In this case, the control circuit 202 can also perform corrections to the detected value of the light receiving unit 30. The control circuit 202 can display the measurement results from the biological detection device 100 on the display 204. The control circuit 202 may also include a communication circuit and an antenna that enable digital communication with external devices.

[0041] The battery 203 supplies power to the biodetection device 100 and the control circuit device 202, and operates the biodetection device 100 and the control circuit device 202.

[0042] The display 204 is a liquid crystal panel or an organic EL display, and performs display operations under the control of the control circuit device 202, displaying various information such as measurement results. The display 204 is located inside the case 205, on the opposite side of the biological detection device 100 with respect to the main circuit board 201, and is covered by a light-transmitting plate-shaped window member 205w fixed to the opening 205o.

[0043] The biological detection device 100 described above comprises a light-emitting unit 10 that emits a first light L1, a light-receiving unit 30 that receives a second light L2 which is the first light L1 reflected by the biological body OB to be detected, and a transmission-reflection unit 20 into which the first light L1 is incident, reflecting a portion of the first light L1 toward the biological body OB to be detected, and into which the second light L2 is incident, transmitting a portion of the second light L2. The second light L2 that has passed through the transmission-reflection unit 20 is incident on the light-receiving unit 30.

[0044] According to the above-described biological detection device 100, the light-emitting unit 10 is positioned in the reflection direction of the transmission-reflecting unit 20, and the light-receiving unit 30 is positioned in the transmission direction of the transmission-reflecting unit 20. As a result, there is only one light entry and exit point (specifically, an opening 101), which reduces the contact surface area of ​​the device with the biological body OB to be detected. This allows the device to be made smaller.

[0045] [Second Embodiment] The following describes a second embodiment of the biological detection device according to the present invention. Note that the biological detection device of the second embodiment is a partial modification of the biological detection device of the first embodiment, and the parts common to the biological detection device of the first embodiment will not be described.

[0046] As shown in Figures 5 and 6, in the biological detection device 100 of this embodiment, the light-receiving unit 30 has a plurality of light-receiving units 31 to 33. Preferably, the number of light-receiving units 30 is the same as the number of light-emitting units 10.

[0047] Specifically, the light-receiving unit 30 includes a first light-receiving unit 31 that receives light in the first wavelength band, a second light-receiving unit 32 that receives light in the second wavelength band, and a third light-receiving unit 33 that receives light in the third wavelength band. This eliminates the need to drive the light-emitting unit 10 separately, thereby reducing power consumption. Furthermore, it improves the light-receiving accuracy of the light-receiving unit 30.

[0048] It is preferable that the first to third light-emitting units 11 to 13 and the first to third light-receiving units 31 to 33 be arranged to form the shortest optical path at their respective wavelengths. Specifically, in the BB cross-sectional view shown in Figure 6, the light-emitting units 10 are arranged in the order of second light-emitting unit 12, first light-emitting unit 11, and third light-emitting unit 13 in the X direction. The light-receiving units 30 are arranged in the order of second light-receiving unit 32, first light-receiving unit 31, and third light-receiving unit 33 in the X direction. Furthermore, in the lateral cross-sectional view shown in Figure 5, the plane parallel to the lateral cross-section intersects between the first light-emitting unit 11 and the first light-receiving unit 31, between the second light-emitting unit 12 and the second light-receiving unit 32, and between the third light-emitting unit 13 and the third light-receiving unit 33.

[0049] [Third Embodiment] The third embodiment of the biological detection device according to the present invention will be described below. The biological detection device of the third embodiment is a partial modification of the biological detection device of the first embodiment, and the parts common to the biological detection device of the first embodiment will not be described.

[0050] As shown in Figures 7 and 8, the biological detection device 100 of this embodiment has a reference light receiving unit 60 that receives the first light L1 transmitted through the transmission and reflection unit 20, instead of the light absorption layer 40 shown in Figure 1. By using the detection information of the first light L1 at the reference light receiving unit 60 to correct the detection information at the light receiving unit 30, noise can be suppressed and the detection accuracy of biological information can be improved.

[0051] [Fourth Embodiment] The following describes a fourth embodiment of the biological detection device according to the present invention. The biological detection device of the fourth embodiment is a partial modification of the biological detection devices of the second and third embodiments, and the parts common to the biological detection devices of the second embodiment and the like will not be described.

[0052] As shown in Figures 9 and 10, in the biological detection device 100 of this embodiment, the reference light receiving unit 60 has a plurality of reference light receiving units. Preferably, the number of reference light receiving units 60 is the same as the number of light emitting units 10 and light receiving units 30.

[0053] Specifically, the reference light receiving unit 60 includes a first reference light receiving unit 61 that receives light in the first wavelength band, a second reference light receiving unit 62 that receives light in the second wavelength band, and a third reference light receiving unit 63 that receives light in the third wavelength band. This eliminates the need to drive the light-emitting unit 10 separately, thereby reducing power consumption. Furthermore, it improves the light reception accuracy of the reference light receiving unit 60.

[0054] It is preferable that the first to third light-emitting sections 11 to 13, the first to third light-receiving sections 31 to 33, and the first to third reference light-receiving sections 61 to 63 are arranged to form the shortest possible optical path at their respective wavelengths.

[0055] [Fifth Embodiment] The following describes a fifth embodiment of the biological detection device according to the present invention. Note that the fifth embodiment of the biological detection device is a partial modification of the first embodiment of the biological detection device, and the parts common to the first embodiment of the biological detection device will not be described.

[0056] As shown in Figures 11 and 12, the biodetector 100 of this embodiment comprises a first substrate BK1, a second substrate BK2, a light-emitting unit 10, a transmission / reflection unit 20, a light-receiving unit 30, a light-absorbing layer 40, a quarter-wave plate 70, and a polarizing member 80.

[0057] The transmission-reflecting section 20 is, for example, a reflective polarizer or a polarizing beam splitter having P-polarization reflection characteristics. The transmission-reflecting section 20 transmits the first polarization component (specifically, S-polarization Ls) and reflects the second polarization component (specifically, P-polarization Lp). The transmission-reflecting section 20 is formed, for example, from a dielectric multilayer film. When the first light L1 or the second light L2 contains P-polarization Lp, the transmission-reflecting section 20 efficiently reflects P-polarization Lp, and when the first light L1 or the second light L2 contains S-polarization Ls, it efficiently transmits S-polarization Ls. The transmission-reflecting section 20 only needs to selectively reflect the first light L1 or the second light L2 according to the polarization direction, and may be, for example, a multilayer film, a wire grid type polarizer such as a wire grid film, or a reflective polarizing element utilizing film stretching.

[0058] Although not shown in the diagram, the transmission-reflecting section 20 may be a reflective polarizer having S-polarization reflection characteristics. In this case, the first polarization component becomes P-polarization Lp, and the second polarization component becomes S-polarization Ls. That is, the transmission-reflecting section 20 transmits the first polarization component (P-polarization Lp) and reflects the second polarization component (S-polarization Ls).

[0059] The polarizing member 80 is provided in the optical path between the light-emitting unit 10 and the transmission / reflection unit 20. The polarizing member 80 transmits the first light L1 emitted from the light-emitting unit 10 and extracts a second polarizing component, which is a predetermined polarizing component, from the first light L1 and reflected by the transmission / reflection unit 20. The polarizing member 80 is, for example, a wire grid type polarizing plate, in which a fine grid of metal such as aluminum is formed on a flat plate such as glass.

[0060] The quarter-wave plate 70 is provided at the opening OP on the side of the biological tissue OB to be detected. The quarter-wave plate 70 converts the second polarization component, P-polarized light Lp, reflected by the transmission-reflection section 20, into left-handed circularly polarized light Le, and converts the right-handed circularly polarized light Li reflected by the biological tissue OB to be detected into the first polarization component, S-polarized light Ls. In the illustrated example, the quarter-wave plate 70 is a film member or a flat plate member formed of a crystal or the like having an optical axis between the X direction and the Z direction.

[0061] The optical path of the biological detection device 100 will be described below. As shown in Figure 11, the light-emitting unit 10 emits a first light, L1 which is the irradiation light DL, towards the biological body OB to be detected through the aperture 101 or aperture OP. The first light L1 emitted from the light-emitting unit 10 passes through the polarizing member 80 to extract a second polarization component, specifically P-polarized light Lp, which is then incident on the transmission-reflecting unit 20. The first light L1 with P-polarized light Lp incident on the transmission-reflecting unit 20 is reflected by the transmission-reflecting unit 20 and incident on the quarter-wave plate 70. The P-polarized light Lp incident on the quarter-wave plate 70 is converted to counterclockwise circularly polarized light Le by the quarter-wave plate 70. The first light L1 with circularly polarized light Le is incident on the biological body OB to be detected. The first light L1 incident on the biological body OB to be detected is reflected by the biological body OB to become the second light L2. In this case, the second light, L2, becomes right-handed circularly polarized Li due to reflection from the biological target OB, particularly hemoglobin.

[0062] The second light, L2, which is right-handed circularly polarized Li reflected from the biological tissue OB being detected, is incident on the quarter-wave plate 70. The circularly polarized Li incident on the quarter-wave plate 70 is converted to S-polarized Ls by the quarter-wave plate 70. The second light, L2, which is S-polarized Ls, is transmitted through the transmission / reflection section 20 and received by the light receiving section 30. The light receiving section 30 receives the second light, L2, which is the reflected light SL that has returned from the biological tissue OB being detected, through the aperture 101 or aperture OP, and outputs a signal corresponding to the intensity of the second light, L2.

[0063] According to the biodetector 100 of this embodiment, a specific polarization is used as the first light L1 by the quarter-wave plate 70, and the polarization is separated in the transmission / reflection section 20, thereby preventing a decrease in light intensity and further reducing power consumption. The polarizing member 80 can extract a specific polarization from the first light L1.

[0064] Furthermore, if the first light L1 incident from the light-emitting section 10 through the polarizing member 80 to the transmission / reflection section 20 is of a specific polarization, for example, P-polarization Lp, then the light-absorbing layer 40 may be omitted.

[0065] Furthermore, the polarizing member 80 may be omitted. Even if the first light L1 emitted from the light-emitting part 10 is unpolarized, the S-polarized Ls of the first light L1 that passes through the transmission-reflection part 20 is absorbed by the light-absorbing layer 40, thus suppressing noise.

[0066] Furthermore, the light-emitting part 10 may emit a specific polarization. In this case, a half-wave plate may be provided instead of the polarizing member 80 to convert the first light L1 to a predetermined polarization direction.

[0067] Furthermore, as shown in Figure 13, the biodetector 100 may have multiple light-receiving units 31 to 33.

[0068] [Sixth Embodiment] The following describes a sixth embodiment of the biological detection device according to the present invention. Note that the sixth embodiment of the biological detection device is a partial modification of the first embodiment of the biological detection device, and the parts common to both the first embodiment and the biological detection device will not be described.

[0069] As shown in Figures 14 and 15, the biological detection device 100 of this embodiment has the arrangement of the light-emitting unit 10 and the light-receiving unit 30 reversed compared to the biological detection device 100 shown in Figure 1.

[0070] The biodetector 100 comprises a first substrate BK1, a second substrate BK2, a light-emitting unit 10, a transmission / reflection unit 20, a light-receiving unit 30, and a light-absorbing layer 40.

[0071] In this embodiment, the first direction D1 is the Z direction, which corresponds to the vertical direction on the plane of Figure 14. The second direction D2 is the Y direction, which corresponds to the horizontal direction on the plane of Figure 14. In the illustrated example, the first substrate BK1 extends perpendicularly from one end B2 of the second substrate BK2 in the second direction D2.

[0072] The light-emitting unit 10 is provided on the second substrate BK2. The light-receiving unit 30 is provided on the first substrate BK1. The transmission and reflection unit 20 is provided at an inclined position where the first light L1 incident from the light-emitting unit 10 and the second light L2 incident on the light-receiving unit 30 intersect.

[0073] In the biodetector 100, the internal space other than the first substrate BK1, the second substrate BK2, the light-emitting section 10, the transmission and reflection section 20, the light-receiving section 30, and the light-absorbing layer 40 is provided with a light-transmitting member LL. The transmission and reflection section 20 is surrounded by the light-transmitting member LL in an inclined state. The light-emitting section 10 and the light-receiving section 30 are arranged to be embedded outside the light-transmitting member LL. The first substrate BK1, the second substrate BK2, and the light-absorbing layer 40 are arranged to cover the outside of the light-transmitting member LL.

[0074] In this embodiment, the transmission-reflecting section 20 receives the first light L1 from the light-emitting section 10, transmits a portion of the first light L1 toward the biological body OB to be detected, and receives the second light L2 from the biological body OB to be detected, reflecting a portion of the second light L2. The second light L2 reflected by the transmission-reflecting section 20 is then incident on the light-receiving section 30.

[0075] In this embodiment, the light-emitting unit 10 is positioned in the first direction D1 of the transmission-reflection unit 20, specifically in the -Z direction or on the lower side of the paper in Figure 14. The light-receiving unit 30 is positioned in the second direction D2 of the transmission-reflection unit 20, specifically in the +Y direction or on the right side of the paper in Figure 14.

[0076] The light-absorbing layer 40 is positioned on the opposite side of the light-receiving section 30, with the transmission-reflection section 20 in between. The light-absorbing layer 40 absorbs the first light L1 reflected by the transmission-reflection section 20. The light-absorbing layer 40 prevents the first light L1 emitted from the light-emitting section 10 and reflected by the transmission-reflection section 20 from being re-entered by the transmission-reflection section 20. This suppresses noise. In this embodiment, the light-absorbing layer 40 may be omitted.

[0077] The circuit board W is mounted on, for example, the second board BK2. The circuit board W may also be mounted on the first board BK1, on both the first board BK1 and the second board BK2, or it may be separate from the first board BK1 and the second board BK2.

[0078] The optical path of the biological detection device 100 will be described below. As shown in Figure 14, the light-emitting unit 10 emits the first light L1, which is the irradiation light DL, towards the biological body OB to be detected through the aperture 101 or aperture OP. Approximately 50% of the first light L1 emitted from the light-emitting unit 10 is transmitted through the transmission and reflection unit 20 and incident on the biological body OB to be detected. The remaining 50% of the first light L1 is reflected by the transmission and reflection unit 20 and absorbed by the light absorption layer 40. The first light L1 incident on the biological body OB to be detected is reflected by the biological body OB to become the second light L2.

[0079] The second light L2 reflected from the biological object OB being detected is reflected by about 50% by the transmission / reflection unit 20 and received by the light receiving unit 30. The light receiving unit 30 receives the second light L2, which is the return light SL that has returned from the biological object OB being detected, through the aperture 101 or aperture OP, and outputs a signal corresponding to the intensity of the second light L2.

[0080] According to the above-described biological detection device 100, the light-emitting unit 10 is positioned in the transmission direction of the transmission-reflecting unit 20, and the light-receiving unit 30 is positioned in the reflection direction of the transmission-reflecting unit 20. As a result, there is only one light entry and exit point (specifically, an opening 101), which reduces the contact surface area of ​​the device with the biological body OB to be detected. This allows the device to be made smaller.

[0081] As shown in Figures 16 and 17, the biodetector 100 may have multiple light-receiving units 31 to 33.

[0082] Furthermore, as shown in Figure 18, the biodetector 100 may have one or more reference light receiving units 60 that receive the first light L1 reflected from the transmission and reflection unit 20.

[0083] Furthermore, as shown in Figure 19, the biodetector 100 may have a reflective polarizer as the transmission-reflecting section 20, and may also have a quarter-wave plate 70 and a polarizing member 80. In the illustrated example, the transmission-reflecting section 20 is, for example, a reflective polarizer having P-polarization reflection characteristics. The transmission-reflecting section 20 transmits the first polarization component (specifically, S-polarization Ls) and reflects the second polarization component (specifically, P-polarization Lp).

[0084] [Other matters] The structure described above is an example, and can be modified in various ways as long as similar functionality can be achieved.

[0085] For example, the size, shape, number, and arrangement of the light-emitting unit 10, light-receiving unit 30, reference light-receiving unit 60, etc., can be changed as appropriate.

[0086] The polarization characteristics, first polarization component, and second polarization component of the transmission / reflection portion 20 are illustrative examples and can be changed as appropriate.

[0087] The interior of the biodetector 100 may have an air layer instead of the light-transmitting member LL. In this case, the side of the transmission-reflection section 20 is fixed to the housing member 50 or the like.

[0088] [Summary of this disclosure] A summary of this disclosure is provided below.

[0089] (Note 1) A light-emitting part that emits first light, A light-receiving unit that receives the second light reflected by the biological object to be detected from the first light, A transmission and reflection section into which the first light is incident and a portion of the first light is reflected toward the biological object to be detected, and into which the second light is incident and a portion of the second light is transmitted, Equipped with, The second light that has passed through the transmission and reflection section is incident on the light receiving section. Biological detection device. By positioning the light-emitting element in the reflection direction of the transmission-reflecting element and the light-receiving element in the transmission direction of the transmission-reflecting element, there is only one light entry and exit point, which reduces the contact surface area of ​​the device with the target organism being detected. This allows for a smaller device size.

[0090] (Note 2) A light-emitting part that emits first light, A light-receiving unit that receives the second light reflected by the biological object to be detected from the first light, A transmission and reflection section into which the first light is incident and a portion of the first light is transmitted toward the biological object to be detected, and into which the second light is incident and a portion of the second light is reflected, Equipped with, The second light reflected by the transmission / reflection section is incident on the light receiving section. Biological detection device. By positioning the light-emitting element in the transmission direction of the transmission-reflecting element and the light-receiving element in the reflection direction of the transmission-reflecting element, there is only one light entry and exit point, which reduces the contact surface area of ​​the device with the target organism being detected. This allows for a smaller device size.

[0091] (Note 3) The light-emitting unit comprises a first light-emitting unit that emits light in the first wavelength band and a second light-emitting unit that emits light in the second wavelength band. It has a light-emitting part and a third light-emitting part that emits light in the third wavelength band, A biological detection device as described in either Appendix 1 or 2. By controlling the operation of each light-emitting unit, multiple pieces of biological information can be detected.

[0092] (Note 4) The light-receiving unit includes a first light-receiving unit that receives light in the first wavelength band, a second light-receiving unit that receives light in the second wavelength band, and a third light-receiving unit that receives light in the third wavelength band. The biological detection device described in Appendix 3. This eliminates the need to drive the light-emitting section separately, thus reducing power consumption. Furthermore, it improves the light-receiving accuracy of the light-receiving section.

[0093] (Note 5) The invention further comprises a first substrate extending in a first direction and a second substrate extending in a second direction intersecting the first direction. The light-receiving unit is provided on the first substrate, and the light-emitting unit is provided on the second substrate. A biological detection device described in any one of the appendices 1 to 4. By crossing the first and second substrates, the light-emitting and light-receiving sections can be efficiently arranged.

[0094] (Note 6) The system further comprises a light-absorbing layer that absorbs the first light transmitted through the aforementioned transmission and reflection portion. A biological detection device as described in any one of the appendices 1 to 5. The light-absorbing layer absorbs the first light that has passed through the transmission and reflection layer, thereby suppressing noise.

[0095] (Note 7) The system further comprises a light-absorbing layer that absorbs the first light reflected from the aforementioned transmission and reflection portion. A biological detection device as described in any one of the appendices 1 to 5. The light-absorbing layer absorbs the first light reflected from the transmission / reflection layer, thereby suppressing noise.

[0096] (Note 8) The system further includes a reference light receiving unit that receives the first light transmitted through the aforementioned transmission and reflection unit. A biological detection device as described in any one of the appendices 1 to 5. By using the detection information of the first light from the reference light receiving unit to correct the detection information from the light receiving unit, noise can be suppressed, and the detection accuracy of biological information can be improved.

[0097] (Note 9) The system further includes a reference light receiving unit that receives the first light reflected by the aforementioned transmission and reflection unit. A biological detection device as described in any one of the appendices 1 to 5. By using the detection information of the first light from the reference light receiving unit to correct the detection information from the light receiving unit, noise can be suppressed, and the detection accuracy of biological information can be improved.

[0098] (Note 10) The aforementioned reference light receiving unit includes a first reference light receiving unit that receives light in the first wavelength band, a second reference light receiving unit that receives light in the second wavelength band, and a third reference light receiving unit that receives light in the third wavelength band. A biological detection device as described in either Appendix 8 or 9. This eliminates the need to drive the light-emitting section in separate units, thus reducing power consumption. Furthermore, it improves the light-receiving accuracy of the reference light receiver.

[0099] (Note 11) The system further comprises a quarter-wave plate provided at the opening on the side of the biological object to be detected, The aforementioned transmission and reflection portion transmits the first polarization component and reflects the second polarization component. A biological detection device as described in any one of the appendices 1 to 7. This allows for the use of a specific polarization as the first light source, and by separating the polarization in the transmission and reflection section, a decrease in light intensity can be prevented, and power consumption can be further reduced.

[0100] (Note 12) The system further includes a polarizing member provided in the optical path between the light-emitting portion and the light-transmitting and reflecting portion. The biological detection device described in Appendix 11. This allows for the extraction of specific polarizations from the first light.

[0101] (Note 13) The light-emitting unit has a surface-emitting type light-emitting element. A biological detection device described in any one of the appendices 1 to 12. This eliminates the need to create multiple wavelengths by stacking multiple light-emitting elements, even if the light-emitting part is multi-colored, allowing for miniaturization of the light-emitting part. [Explanation of Symbols]

[0102] 10,11~13…Light-emitting section, 10a…Light-emitting element, 20…Transmission and reflection section, 30,31~33…Light-receiving section, 40…Light-absorbing layer, 50…Housing member, 60,61~63…Reference light-receiving section, 70…Quarter wave plate, 80…Polarizing member, 100…Biological detection device, 101…Aperture, 200…Biological information measurement device, 200a…Main unit, 200b…Wristband, BK1…First substrate, BK2…Second substrate, D1…First direction, D2…Second direction, DL…Irradiated light, HB…Biological organism, L1…First light, L2…Second light, LL…Light-transmitting member, Le…Counterclockwise circular polarization, Li…Clockwise circular polarization, Lp…P polarization, Ls…S polarization, OB…Biological organism to be detected, OP…Aperture, P…Drive circuit, SL…Reflected light, W…Circuit board

Claims

1. A light-emitting part that emits first light, A light-receiving unit that receives the second light reflected by the biological object to be detected from the first light, A transmission and reflection section into which the first light is incident and a portion of the first light is reflected toward the biological object to be detected, and into which the second light is incident and a portion of the second light is transmitted, Equipped with, The second light that has passed through the transmission and reflection section is incident on the light receiving section. Biological detection device.

2. A light-emitting part that emits first light, A light-receiving unit that receives the second light reflected by the biological object to be detected from the first light, A transmission and reflection section into which the first light is incident and a portion of the first light is transmitted toward the biological object to be detected, and into which the second light is incident and a portion of the second light is reflected, Equipped with, The second light reflected by the transmission / reflection section is incident on the light receiving section. Biological detection device.

3. The light-emitting unit comprises a first light-emitting unit that emits light in the first wavelength band and a second light-emitting unit that emits light in the second wavelength band. It has a light-emitting part and a third light-emitting part that emits light in the third wavelength band, A biological detection device according to either claim 1 or 2.

4. The light-receiving unit includes a first light-receiving unit that receives light in a first wavelength band, a second light-receiving unit that receives light in a second wavelength band, and a third light-receiving unit that receives light in a third wavelength band. The biological detection device according to claim 3.

5. The invention further comprises a first substrate extending in a first direction and a second substrate extending in a second direction intersecting the first direction. The light-receiving unit is provided on the first substrate, and the light-emitting unit is provided on the second substrate. A biological detection device according to either claim 1 or 2.

6. The system further comprises a light-absorbing layer that absorbs the first light transmitted through the aforementioned transmission and reflection portion. The biological detection device according to claim 1.

7. The system further comprises a light-absorbing layer that absorbs the first light reflected from the aforementioned transmission and reflection portion. The biological detection device according to claim 2.

8. The system further includes a reference light receiving unit that receives the first light transmitted through the aforementioned transmission and reflection unit. The biological detection device according to claim 1.

9. The system further includes a reference light receiving unit that receives the first light reflected by the aforementioned transmission and reflection unit. The biological detection device according to claim 2.

10. The reference light receiving unit includes a first reference light receiving unit that receives light in a first wavelength band, a second reference light receiving unit that receives light in a second wavelength band, and a third reference light receiving unit that receives light in a third wavelength band. A biological detection device according to any one of claims 8 and 9.

11. The system further comprises a quarter-wave plate provided at the opening on the side of the biological object to be detected, The aforementioned transmission and reflection portion transmits the first polarization component and reflects the second polarization component. A biological detection device according to either claim 1 or 2.

12. The system further includes a polarizing member provided in the optical path between the light-emitting portion and the light-transmitting and reflecting portion. The biological detection device according to claim 11.

13. The light-emitting unit has a surface-emitting type light-emitting element. A biological detection device according to either claim 1 or 2.

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