Detection Device

Abstract

A detection device (1) comprises: a housing (200); a light source (60) that is provided to the housing (200) so as to enable an irradiation side which is outside of the housing (200) to be irradiated; a light sensor (10) that is provided in the housing (200) so as to be aligned with the light source (60) in a first direction of the housing (200) and that is capable of detecting light incident from the irradiation side of the light source (60); and a reflection member (80) that is provided in the housing (200) so as to be positioned between the light source (60) and the light sensor (10) and that is capable of reflecting the incident light towards the irradiation side of the light source (60).

Description

[Technical Field]

[0001] The present invention relates to a detection device. [Background technology]

[0002] Optical sensors capable of detecting fingerprint patterns and vein patterns are known (for example, Patent Document 1). Among such optical sensors, sensors having multiple photodiodes in which an organic semiconductor material is used as an active layer are known. The organic semiconductor material is disposed between a lower electrode and an upper electrode, and a signal line for outputting a detection signal to a detection circuit is electrically connected to the lower electrode of the photodiode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-32005 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, the amount of light reaching the optical sensor decreases exponentially as the distance between the light source and the optical sensor increases. For this reason, there is a need for arranging the light source and the optical sensor inside the housing of conventional detection devices to improve detection accuracy.

[0005] An object of the present invention is to provide a detection device that can improve detection accuracy using a light source and an optical sensor housed inside a housing. [Means for solving the problem]

[0006] A detection device according to one embodiment of the present invention includes a housing, a light source provided in the housing so as to be able to illuminate an illumination side outside the housing, an optical sensor provided in the housing so as to be aligned with the light source in a first direction of the housing and capable of detecting light incident from the illumination side of the light source, and a reflective member provided in the housing so as to be positioned between the light source and the optical sensor and capable of reflecting the incident light toward the illumination side of the light source.

[0007] A detection device according to one embodiment of the present invention comprises a housing, a light source provided in the housing so as to be capable of irradiating an illumination side outside the housing, an optical sensor provided in the housing so as to be aligned with the light source in a first direction of the housing and capable of detecting light incident from the illumination side of the light source, and a cover provided on the housing so as to protrude from the housing while covering the light source, wherein the cover comprises: a cover body protruding from the housing and capable of contacting an object to be measured; an opening formed in a part of the cover body that comes into contact with the object to be measured, through which light emitted by the light source is emitted toward the outside of the cover body; and a reflective layer provided on the inner surface of the cover body that is capable of reflecting the light emitted by the light source and focusing it on the opening. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of the appearance of a detection device according to the first embodiment when a finger is placed inside the detection device as viewed from the side of a housing. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along the line AA shown in FIG. [Figure 3] FIG. 3 is a schematic diagram showing an example of the configuration of the optical sensor and light source of the detection device shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view schematically illustrating an example of a laminated structure of the optical sensor taken along the line BB shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view schematically illustrating a configuration example of the detection device taken along the CC cross section shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view illustrating an example of the action of light in the comparative detection device according to the first embodiment. [Figure 7]FIG. 7 is a cross-sectional schematic diagram of the detection device according to the second embodiment taken along the line AA shown in FIG. [Figure 8] FIG. 8 is a schematic diagram showing an example of the configuration of the optical sensor and light source of the detection device shown in FIG. [Figure 9] FIG. 9 is a cross-sectional schematic diagram of the light source and the cover taken along the line DD shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view schematically illustrating a configuration example of the detection device in the E-E cross section shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view illustrating an example of the action of light in the comparative detection device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Modes for carrying out the invention (embodiments) will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, for clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each figure, elements similar to those previously described with reference to the preceding figures are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0010] In this specification and claims, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0011] (Embodiment 1) [Detection device] Fig. 1 is a schematic diagram showing an example of the appearance of the detection device according to embodiment 1 when a finger is placed inside the detection device as viewed from the side of the housing. Fig. 2 is a schematic cross-sectional view taken along the line AA shown in Fig. 1. Fig. 3 is a schematic diagram showing an example of the configuration of the optical sensor and light source of the detection device shown in Fig. 1. Fig. 4 is a schematic cross-sectional view taken along the line BB shown in Fig. 3, showing an example of the stacked configuration of the optical sensor. Note that Fig. 2 shows only the basic configuration of the detection device according to embodiment 1, and omits other configurations.

[0012] The detection device 1 shown in FIG. 1 is a ring-shaped device that can be attached to and detached from the human body, and is worn on a finger Fg of the human body. The finger Fg includes the thumb, index finger, middle finger, ring finger, little finger, etc. The human body is a person to be authenticated, whose identity is verified by the detection device 1. The detection device 1 can detect biometric information about a living body from the finger Fg on which it is worn. The finger Fg is an example of a measurement target. The measurement target is a living body or a part of a living body, and is a measurement target. The detection device 1 is made into a ring or wristband, making it easy for a user to carry. In the following description, it is assumed that the detection device 1 is used as a ring. The detection device 1 can use the detected biometric information to authenticate the person to be authenticated.

[0013] 2, the detection device 1 includes a housing 200, a light source 60, an optical sensor 10, and a reflective member 80. The detection device 1 includes a battery (not shown) inside the housing 200 and is a device that operates using power from the battery.

[0014] The housing 200 is formed in a ring shape (annular shape) that can be worn on a finger Fg, and is a wearable member that is worn on a living body. In the example shown in FIG. 2, the housing 200 includes a first housing 210 and a second housing 220. The first housing 210 and the second housing 220 are integrally formed into a ring shape. The first housing 210 is a member that comes into contact with the human body on which the housing 200 is worn. The first housing 210 houses the light source 60, the optical sensor 10, the reflective member 80, etc. The first housing 210 is formed in a ring shape using a housing material such as a transparent synthetic resin or silicone. The second housing 220 has a surface of the housing 200 that covers the outer peripheral surface 210A of the first housing 210. The second housing 220 is formed in a ring shape using a material such as a metal or a non-transparent synthetic resin. The housing 200 accommodates a flexible printed circuit board 70, on which the light source 60, the optical sensor 10, etc. are mounted, inside the first housing 210. The flexible printed circuit board 70 is accommodated inside the housing 200, for example, by forming the housing 200 in a ring shape in a mold and filling a filling material around the flexible printed circuit board 70.

[0015] 3, the flexible printed circuit board 70 is formed in a deformable band shape. The flexible printed circuit board 70 has a first mounting area 73 and a second mounting area 74. The first mounting area 73 is provided on the front side of the flexible printed circuit board 70 and is an area where the light source 60 and the like are mounted. The second mounting area 74 is provided on the back side of the flexible printed circuit board 70 and is an area where the control circuit 122, the power supply circuit 123, and the like are mounted. The flexible printed circuit board 70 electrically connects the light source 60, the optical sensor 10, and the like to the control circuit 122 and the power supply circuit 123.

[0016] In the following description, the first direction Dx is a direction in a plane parallel to the flexible printed circuit board 70 and is the same direction as the circumferential direction 200C. The second direction Dy is a direction in a plane parallel to the flexible printed circuit board 70 and is a direction perpendicular to the first direction Dx. The second direction Dy may intersect with the first direction Dx without being perpendicular thereto. The third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy. The third direction Dz is a normal direction to the flexible printed circuit board 70. In addition, "plan view" refers to the positional relationship when viewed from a direction perpendicular to the flexible printed circuit board 70 and the sensor substrate 21.

[0017] In this embodiment, the optical sensor 10 is provided on the flexible printed circuit board 70 alongside the light source 60 in the circumferential direction 200C along the first direction Dx. By being disposed close to the light source 60 in the circumferential direction 200C, the optical sensor 10 is able to detect light emitted by the light source 60 and reflected by the finger Fg (human body).

[0018] The sensor substrate 21 is an insulating substrate, and is formed in a strip shape using, for example, a film-like resin. The sensor substrate 21 is a deformable substrate on which the optical sensor 10 is mounted. The sensor substrate 21 is attached to the flexible printed circuit board 70, thereby positioning the optical sensor 10 near the light source 60 in the circumferential direction 200C of the housing 200. The sensor substrate 21 has an area on which the optical sensor 10 is mounted.

[0019] 2, the flexible printed circuit board 70 is housed inside the housing 200 so that the surface on which the optical sensor 10, the reflective member 80, and the light source 60 are mounted faces the inner circumferential surface 210B of the housing 200. If the flexible printed circuit board 70 is light-transmitting, the optical sensor 10, the reflective member 80, and the light source 60 may be mounted on the back surface opposite to the front surface. In this case, the light source 60 may be disposed so that it emits light toward the flexible printed circuit board 70 and the light that has passed through the flexible printed circuit board 70 is emitted toward the outside of the housing 200.

[0020] As shown in FIG. 2, the light source 60 is provided inside the first housing 210 of the housing 200 and is configured to be able to irradiate light toward the center of the housing 200. For example, an inorganic LED (Light Emitting Diode) or an organic EL (Organic Light Emitting Diode) is used as the light source 60. The light source 60 irradiates light of a predetermined wavelength. In this embodiment, the light source 60 has a plurality of light sources so as to be able to irradiate near-infrared light, red light, and green light.

[0021] Light emitted from the light source 60 is reflected by the surface of the object to be detected, such as a finger Fg, and enters the optical sensor 10. Alternatively, the light emitted from the light source 60 may be reflected inside the finger Fg or pass through the finger Fg and then enter the multiple photodiodes PD of the optical sensor 10. This allows the detection device 1 to detect information about the living body inside the finger Fg or the like. The information about the living body includes, for example, the pulse wave and pulse rate of the finger or palm. In other words, the detection device 1 may be configured as a vein detection device that detects biological information such as veins. When detecting a fingerprint or vein pattern of the object to be detected, the detection device 1 has multiple photodiodes PD of the optical sensor 10 arranged in a matrix.

[0022] The optical sensor 10 is provided inside the first housing 210 of the housing 200, and is a sensor capable of detecting light incident from the irradiation side of the light source 60. The irradiation side of the light source 60 is inside the ring-shaped housing 200, and is the side that irradiates the finger Fg of the measurement target wearing the housing 200. The optical sensor 10 detects light that is irradiated by the light source 60 and reflected by the finger Fg, etc., and light that directly enters the housing 200. The optical sensor 10 is an organic photodiode (OPD). The sensor substrate 21 is attached to the flexible printed circuit board 70, and the optical sensor 10 is provided inside the housing 200 so as to be aligned with the light source 60 in the circumferential direction 200C of the housing 200 (first direction Dx).

[0023] As shown in FIG. 3, the optical sensor 10 has a photodiode PD, which is an organic photodiode. The optical sensor 10 has two lower electrodes 11 aligned along the circumferential direction 200C. The optical sensor 10 is mounted on a single sensor substrate 21 and electrically connected to a flexible printed circuit board 70 via the sensor substrate 21. The optical sensor 10 has a stacked configuration in which two lower electrodes 11 aligned in a first direction Dx and one upper electrode 15 are stacked. The upper electrode 15 covers the two lower electrodes 11 in a plan view.

[0024] The sensor substrate 21 has a connection portion 212. The connection portion 212 is electrically connected to the control circuit 122, the power supply circuit 123, etc. The connection portion 212 is electrically connected to a wiring 26 provided on the sensor substrate 21. The wiring 26 is a shield layer, and is formed, for example, of a metal wiring, made of a material having better conductivity than the lower electrode 11 of the photodiode PD. The wiring 26 is provided in a layer between the sensor substrate 21 and the photodiode PD in the third direction Dz. The sensor substrate 21 electrically connects the connection portion 212 and the upper electrode 15 via a power supply line (not shown), and supplies a sensor power supply signal from the power supply circuit 123 to the upper electrode 15 via the connection portion 212. As a result, the upper electrode 15 of the optical sensor 10 is supplied with a sensor power supply signal from the power supply circuit 123 via the power supply electrode 211.

[0025] As shown in Fig. 4, the optical sensor 10 includes a sensor substrate 21 and a photodiode PD. In this embodiment, the optical sensor 10 further includes wiring 26 and an insulating layer 27. The insulating layer 27 is provided on the sensor substrate 21 to cover the wiring 26. The insulating layer 27 may be an inorganic insulating film or an organic insulating film. The wiring 26 may be formed in the same layer as the lower electrode 11.

[0026] The photodiode PD is provided on the insulating layer 27. The photodiode PD has a lower electrode 11, a lower buffer layer 12, an active layer 13, an upper buffer layer 14, and an upper electrode 15. In the photodiode PD, the lower electrode 11, the lower buffer layer 12 (hole transport layer), the active layer 13, the upper buffer layer 14 (electron transport layer), and the upper electrode 15 are stacked in this order in a third direction Dz perpendicular to the sensor substrate 21.

[0027] The lower electrode 11 is an anode electrode of the photodiode PD and is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide). The active layer 13 changes its characteristics (for example, voltage-current characteristics and resistance value) depending on the light irradiated thereon. An organic material is used as the material for the active layer 13. Specifically, the active layer 13 has a bulk heterostructure in which a p-type organic semiconductor and an n-type fullerene derivative (PCBM), which is an n-type organic semiconductor, are mixed. The active layer 13 can be made of, for example, a low molecular weight organic material such as C60 (fullerene), PCBM (phenyl C61-butyric acid methyl ester), CuPc (copper phthalocyanine), F16CuPc (fluorinated copper phthalocyanine), rubrene (5,6,11,12-tetraphenyltetracene), or PDI (a perylene derivative).

[0028] The active layer 13 can be formed by a vapor deposition method (dry process) using these low-molecular-weight organic materials. In this case, the active layer 13 may be, for example, a laminated film of CuPc and F16CuPc, or a laminated film of rubrene and C60. The active layer 13 can also be formed by a coating method (wet process). In this case, the active layer 13 is made of a material that combines the above-mentioned low-molecular-weight organic material with a high-molecular-weight organic material. Examples of high-molecular-weight organic materials that can be used include P3HT (poly(3-hexylthiophene)) and F8BT (F8-alt-benzothiadiazole). The active layer 13 can be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0029] The lower buffer layer 12 is a hole transport layer. The upper buffer layer 14 is an electron transport layer. The lower buffer layer 12 and the upper buffer layer 14 are provided to facilitate the holes and electrons generated in the active layer 13 reaching the lower electrode 11 or the upper electrode 15. The lower buffer layer 12 (hole transport layer) is directly in contact with the lower electrode 11 and is also provided in the region between adjacent lower electrodes 11. The active layer 13 is directly in contact with the lower buffer layer 12. The material of the hole transport layer is a metal oxide layer. Tungsten oxide (WO3), molybdenum oxide, etc. are used as the metal oxide layer.

[0030] The upper buffer layer 14 (electron transport layer) is directly on and in contact with the active layer 13, and the upper electrode 15 is directly on and in contact with the upper buffer layer 14. Ethoxylated polyethyleneimine (PEIE) is used as the material for the electron transport layer.

[0031] The materials and manufacturing methods of the lower buffer layer 12, the active layer 13, and the upper buffer layer 14 are merely examples, and other materials and manufacturing methods may be used. For example, the lower buffer layer 12 and the upper buffer layer 14 are not limited to single-layer films, and may be formed as multilayer films including an electron blocking layer and a hole blocking layer.

[0032] The upper electrode 15 is provided on the upper buffer layer 14. The upper electrode 15 is a cathode electrode of the photodiode PD and is continuously formed over the entire first optical sensor 10A and the second optical sensor 10B. In other words, the upper electrode 15 is continuously provided on the multiple photodiodes PD. The upper electrode 15 faces the multiple lower electrodes 11, with the lower buffer layer 12, the active layer 13, and the upper buffer layer 14 sandwiched between them. The upper electrode 15 is formed of a light-transmitting conductive material such as ITO or IZO. The upper electrode 15 is electrically connected to the power supply circuit 123 via a connection portion 212. In the first optical sensor 10A, the photodiode PD is well sealed by providing a first housing 210 on the upper electrode 15 and other components.

[0033] As shown in FIG. 3, the reflective member 80 is disposed between the light source 60 and the optical sensor 10 in the circumferential direction 200C (first direction Dx) of the housing 200 and is capable of reflecting incident light toward the irradiation side of the light source 60. The incident light includes, for example, light (reflected light) incident from the finger Fg and light directly incident from the light source 60. In the example shown in FIG. 3, the reflective member 80 reflects the incident light toward the inner circumferential surface 210B (inside) of the housing 200. In this embodiment, the reflective member 80 is formed as a reflective layer having a reflectance of 50% or more between the light source 60 and the optical sensor 10 on the flexible printed circuit board 70. The reflective member 80 can be formed as a reflective layer using, for example, a highly reflective metal material such as Al or Ag, or a dielectric multilayer film that reflects light in the light source wavelength range. The reflective member 80 may be, for example, a reflector made of a metal such as Al or an Al alloy with metallic luster, paint, a mirror, or the like, and provided on the flexible printed circuit board 70. The reflective member 80 is provided on the flexible printed circuit board 70 so as to cover a region 75 between the light source 60 and the photodiode PD. The region 75 is a rectangular region of the flexible printed circuit board 70 that is defined by the distance D in the first direction Dx and the width of the flexible printed circuit board 70 in the second direction Dy.

[0034] In this embodiment, the distance D is the distance from the center of the light source 60 to one end of the lower electrode 11 of the nearest photodiode PD, but is not limited to this. For example, the distance D may be the distance from the end of the light source 60 to the opposite end of the optical sensor 10, or the distance from the center or end of the light source 60 to the opposite end of the sensor substrate 21, etc.

[0035] The reflective member 80 may be provided so as to cover the entire region 75, or may be provided so as to cover a portion of the region 75. In this embodiment, the length of the reflective member 80 in the first direction Dx is equal to the distance D. The length of the reflective member 80 in the second direction Dy is smaller than the length (width) of the flexible printed circuit board 70 and larger than the length of the sensor substrate 21. Note that the length of the reflective member 80 in the second direction Dy may be smaller than the length (width) of the flexible printed circuit board 70 and larger than or equal to the length of the photodiode PD.

[0036] The multiple wirings 26 of the sensor substrate 21 are connected to the detection circuit 48 of the control circuit 122 via multiple signal lines of the flexible printed circuit board 70. In other words, the detection circuit 48 is electrically connected to the lower electrode 11 of the optical sensor 10 via multiple signal lines. Note that the detection circuit 48 may be formed as a circuit separate from the control circuit 122.

[0037] The control circuit 122 is a circuit that supplies control signals to the multiple photodiodes PD to control the detection operation. The multiple photodiodes PD output electrical signals corresponding to the light irradiated thereon as detection signals Vdet to the detection circuit 48. In this embodiment, the detection signals Vdet of the multiple photodiodes PD are output to the detection circuit 48 sequentially in a time-division manner. In other words, the multiple signal lines are electrically connected to the detection circuit 48 sequentially in a time-division manner. As a result, the detection device 1 detects information about the object to be detected based on the detection signals Vdet from the multiple photodiodes PD. The control circuit 122 operates using power supplied from the power supply circuit 123.

[0038] The detection circuit 48 is, for example, an analog front end (AFE). The detection circuit 48 is a signal processing circuit having at least the functions of a detection signal amplifier and an A / D converter. The detection signal amplifier amplifies the detection signal Vdet. The A / D converter converts the analog signal output from the detection signal amplifier into a digital signal.

[0039] The above describes an example of the configuration of the detection device 1 according to this embodiment. Note that the configuration described above using Figures 1 to 4 is merely an example, and the configuration of the detection device 1 according to this embodiment is not limited to this example. The configuration of the detection device 1 according to this embodiment can be flexibly modified depending on the specifications and operation.

[0040] [Distance between the light source and the optical sensor of the detection device] Next, the distance D between the light source 60 and the optical sensor 10 of the detection device 1 will be described. For example, if the light source 60 and the optical sensor 10 are too close to each other, a larger proportion of the light reaching the optical sensor 10 will pass through the vicinity of the surface of the finger Fg, which has a small amount of blood vessels, causing a decrease in the signal level of the biometric information and preventing normal sensing. For this reason, the distance between the light source 60 and the optical sensor 10 typically needs to be approximately 5 mm or more. Furthermore, the farther the light source 60 and the optical sensor 10 are from each other, the greater the amount of light absorbed by the human body, and the greater the amount of light reaching the optical sensor 10, resulting in an exponential decrease in the amount of light required from the light source.

[0041] FIG. 5 is a cross-sectional view showing a configuration example of the detection device 1 taken along the CC cross section shown in FIG. 3. In the detection device 1 shown in FIG. 5, the distance D between the light source 60 and the optical sensor 10 is 5 mm. In the detection device 1, a reflective member 80 is disposed so as to cover the surface of the sensor substrate 21 between the light source 60 and the optical sensor 10. When the detection device 1 is worn on a finger Fg, the light source 60 emits light L1, which passes through the housing 200 and illuminates the finger Fg. The light L1 enters the inside of the finger Fg through the skin and passes through or is reflected by muscle tissue, arteries Fg-a, veins Fg-v, etc. The reflected light L2, which is light L1 reflected inside the finger Fg, travels toward the inside of the finger Fg and toward the detection device 1. When the reflected light L2 is emitted toward the outside of the finger Fg and reaches the optical sensor 10 of the detection device 1, the photodiode PD of the detection device 1 receives the reflected light L2. Furthermore, when the reflected light L2 is emitted toward the outside of the finger Fg and encounters the reflecting member 80 of the detection device 1, it is incident on the reflecting member 80, is reflected by the reflecting member 80, and is then incident back into the finger Fg. The reflected light L2 is reflected inside the finger Fg, and becomes reflected light L3, which may head toward the inside of the finger Fg or toward the detection device 1. When the reflected light L3 is emitted toward the outside of the finger Fg and encounters the optical sensor 10 of the detection device 1, the photodiode PD of the detection device 1 receives the reflected light L2. This allows the detection device 1 to receive the reflected light L2 and the reflected light L3 reflected by the reflecting member 80 with the photodiode PD of the optical sensor 10.

[0042] In contrast, a case will be described where the detection device 1 does not include the reflecting member 80. Fig. 6 is a cross-sectional schematic diagram for explaining an example of the action of light in the comparative detection device 1000 according to embodiment 1. The comparative detection device 1000 shown in Fig. 6 has the same basic configuration as the detection device 1 of embodiment 1, but differs from the detection device 1 in that it does not include the reflecting member 80.

[0043] In the comparative detecting device 1000 shown in FIG. 6 , the distance D between the light source 60 and the optical sensor 10 is 5 mm. In the comparative detecting device 1000, the surface of the sensor substrate 21 between the light source 60 and the optical sensor 10 is exposed. When the comparative detecting device 1000 is worn on a finger Fg, the light source 60 emits light L1, which passes through the housing 200 and illuminates the finger Fg. The light L1 enters the inside of the finger Fg through the skin and passes through or is reflected by muscle tissue, arteries Fg-a, and veins Fg-v. The reflected light L2, which is light L1 reflected inside the finger Fg, travels toward the inside of the finger Fg or toward the comparative detecting device 1000. When the reflected light L2 travels toward the outside of the finger Fg and encounters the optical sensor 10 of the comparative detecting device 1000, the photodiode PD of the comparative detecting device 1000 receives the reflected light L2. However, the reflected light L4 from the finger Fg toward the sensor substrate 21 between the light source 60 and the optical sensor 10 is not received by the optical sensor 10. Therefore, the comparative detection device 1000 is unable to receive the reflected light L4 reflected inside the finger Fg with the optical sensor 10, and the reflected light L4 is lost.

[0044] The detection device 1 according to the first embodiment is compared with the comparative detection device 1000. The detection device 1 can receive, with the optical sensor 10, reflected light L2 and reflected light L3 reflected by the reflecting member 80, of the light L1 emitted from the light source 60 to the inside of the finger Fg. In contrast, the comparative detection device 1000 does not include the reflecting member 80, and therefore receives only reflected light L2 and cannot receive reflected light L4, of the light L1 emitted from the light source 60 to the inside of the finger Fg. Therefore, the detection device 1 can receive a larger amount of reflected light L3 reflected by the reflecting member 80 than the comparative detection device 1000. As a result, by providing the reflecting member 80 between the light source 60 and the optical sensor 10, the detection device 1 can reduce light loss between the light source 60 and the optical sensor 10. As a result, the detection device 1 can improve the detection accuracy using the light source 60 and the optical sensor 10 housed inside the housing 200.

[0045] Since the detection device 1 can suppress loss of the amount of light reaching the optical sensor 10 even when the distance D between the light source 60 and the optical sensor 10 is 5 mm or more, it is possible to improve the accuracy of detecting light from the light source 60 in the ring-shaped housing 200. As a result, the detection device 1 can detect a peak in the PI value when the distance D between the light source 60 and the optical sensor 10 is between 5 mm and 15 mm, thereby further improving the detection accuracy.

[0046] In the detection device 1, the reflectance of the reflective member 80 is 50% or higher. For example, because veins Fg-v and the like are present inside the finger Fg, light L1 that enters the inside of the finger Fg is reflected in various directions. Even if the reflected light L2 from the finger Fg is incident on the reflective member 80 at various angles of incidence, the detection device 1 can reflect the reflected light L2 toward the finger Fg. This allows the detection device 1 to improve the accuracy of detecting light from the light source 60 even when the housing 200 is attached to a measurement target such as a finger Fg.

[0047] The optical sensor 10 of the detection device 1 is an organic photodiode, which allows the detection device 1 to detect light reflected by the finger Fg with high accuracy using the optical sensor 10.

[0048] In the detection device 1, the optical sensor 10 and the light source 60 are provided on a flexible printed circuit board 70, the lower electrode 11 of the optical sensor 10 is electrically connected to a wiring 26, and the wiring 26 is electrically connected to the flexible printed circuit board 70. This allows the detection device 1 to be manufactured with the flexible printed circuit board 70 housed inside the housing 200, thereby improving productivity.

[0049] The detection device 1 has a ring-shaped housing 200. As a result, even if a gap is provided between the light source 60 and the optical sensor 10 inside the ring-shaped housing 200, the presence of the reflective member 80 between them improves the accuracy of detecting light emitted from the light source 60 toward the finger Fg.

[0050] (Embodiment 2) If the distance D between the light source 60 and the optical sensor 10 is too small, the photodiode PD closest to the light source of the optical sensor 10 will detect less blood vessel information than the photodiodes PD at other locations, making it difficult to measure the pulse wave. Furthermore, the optical absorptivity of human tissue is high, and the amount of transmitted light decreases exponentially according to the distance D between the light source 60 and the optical sensor 10. For this reason, the detection device according to the second embodiment will be described with a configuration in which the light source 60 and the optical sensor 10 are closer than those in the first embodiment.

[0051] [Detection device according to embodiment 2] Fig. 7 is a cross-sectional schematic diagram of a detection device according to embodiment 2 taken along the line AA in Fig. 1. Fig. 7 shows only the basic configuration of the detection device according to embodiment 2, and omits other configurations. Fig. 8 is a schematic diagram showing an example configuration of an optical sensor and a light source of the detection device 1A shown in Fig. 7. Fig. 9 is a cross-sectional schematic diagram of a light source and a cover taken along the line DD in Fig. 8.

[0052] 7 is a ring-shaped device that can be attached to and detached from the human body, similar to the detection device 1 of the first embodiment, and is worn on a finger Fg of the human body. The detection device 1A can detect biological information about the living body from the finger Fg on which it is worn. The detection device 1A includes a housing 200, a light source 60, an optical sensor 10, and a cover 90.

[0053] Similar to the housing 200 according to the first embodiment, the housing 200 includes a first housing 210 and a second housing 220. The housing 200 is formed by integrating the first housing 210 and the second housing 220 into a ring shape. The first housing 210 is a member that comes into contact with the human body on which the housing 200 is worn. The first housing 210 accommodates the light source 60, the optical sensor 10, and the like inside. The first housing 210 accommodates a portion of the cover 90 inside, with the other portion of the cover 90 protruding from the inner circumferential surface 210B to the outside. That is, the first housing 210 is configured such that a portion of the cover 90 protrudes from the inner circumferential surface 210B, and the cover 90 can be pressed against the finger Fg when the housing 200 is worn on the finger Fg.

[0054] As shown in FIG. 8 , the flexible printed circuit board 70 is formed in a deformable band shape. The flexible printed circuit board 70 has a second mounting area 74 and a third mounting area 76. The second mounting area 74 is provided on the back side of the flexible printed circuit board 70 and is an area where the control circuit 122, the power supply circuit 123, etc. are mounted. The third mounting area 76 is provided on the front side of the flexible printed circuit board 70 and is an area where the light source 60, etc. are mounted and where the cover 90 is provided. The flexible printed circuit board 70 electrically connects the light source 60, the optical sensor 10, etc. to the control circuit 122 and the power supply circuit 123. The flexible printed circuit board 70 is housed inside the housing 200 so that the back side faces the inner circumferential surface 210B of the housing 200. That is, the flexible printed circuit board 70 is housed inside the housing 200 so that a portion of the cover 90 protrudes from the inner circumferential surface 210B.

[0055] The optical sensor 10 is provided in the housing 200 so as to be aligned with the light source 60 in the circumferential direction 200C (first direction Dx) of the housing 200, and is a sensor capable of detecting light incident from the irradiation side of the light source 60. The optical sensor 10 is provided on the flexible printed circuit board 70 so as to be aligned with the light source 60 in the circumferential direction 200C along the first direction Dx. By being disposed close to the light source 60 in the circumferential direction 200C, the optical sensor 10 is capable of detecting light emitted by the light source 60 and reflected by a finger Fg (human body). In the detection device 1A, a distance D between the light source 60 and the optical sensor 10 is set to 5 mm or less, thereby suppressing a decrease in the amount of light reaching the optical sensor 10 from the light source 60.

[0056] The optical sensor 10 detects light emitted by the light source 60 and reflected by a finger Fg or the like, directly incident light, etc. The optical sensor 10 is an organic photodiode. The optical sensor 10 is provided inside the housing 200 so as to be aligned with the light source 60 in the circumferential direction 200C (first direction Dx) of the housing 200 by mounting the sensor substrate 21 on a flexible printed circuit board 70. As in the first embodiment, the optical sensor 10 has a photodiode PD which is an organic photodiode (see FIG. 3).

[0057] 4, the optical sensor 10 includes a sensor substrate 21 and a photodiode PD. The photodiode PD includes a lower electrode 11, a lower buffer layer 12 (hole transport layer), an active layer 13, an upper buffer layer 14 (electron transport layer), and an upper electrode 15 stacked in this order in a third direction Dz perpendicular to the sensor substrate 21. In this embodiment, the optical sensor 10 further includes wiring 26 and an insulating layer 27.

[0058] The sensor board 21 is a deformable board on which the optical sensor 10 is mounted. The sensor board 21 is attached to the flexible printed circuit board 70, thereby positioning the optical sensor 10 near the cover 90 in the circumferential direction 200C of the housing 200. The sensor board 21 arranges the optical sensor 10 on the flexible printed circuit board 70 so that the distance D between the optical sensor 10 and the light source 60 covered by the cover 90 is 5 mm or less.

[0059] The light source 60 is covered by a cover 90 on the sensor substrate 21 so that the emitted light does not directly reach the optical sensor 10. The light source 60 has multiple light sources that can emit near-infrared light, red light, and green light. The light emitted from the light source 60 is emitted to the outside of the housing 200 from an opening 92 in a cover body 91 of the cover 90, reflected by the surface of the object to be detected such as a finger Fg, and enters the optical sensor 10. Of the light emitted from the light source 60, the light heading toward the optical sensor 10 is blocked by the cover 90.

[0060] The sensor board 21 has the same configuration as in embodiment 1. In embodiment 2, the sensor board 21 is arranged such that a portion of the sensor board 21 overlaps the third mounting area 76 of the flexible printed circuit board 70 so that the optical sensor 10 is closer to the cover 90. As a result, in the detection device 1A, the distance D between the light source 60 and the optical sensor 10 is 5 mm or less.

[0061] As shown in FIG. 9 , the cover 90 is provided to protrude from the housing 20 while covering the light source 60. The cover 90 includes a cover main body 91, an opening 92, and a reflective layer 93. The cover main body 91 is formed into a hollow hemispherical shape using a light-blocking material such as synthetic resin or metal. In this embodiment, the cover main body 91 is described as being circular in plan view, but may be formed into a rectangular, triangular, polygonal, or other shape. That is, the cover main body 91 may be formed into a cylindrical, triangular prism, polygonal prism, or other shape. The cover main body 91 is formed to have a strength sufficient to withstand contact with, for example, a finger Fg. In this embodiment, the cover main body 91 has a fixing portion 91A formed at an end portion thereof fixed to the light source 60, but this is not limiting. The fixing portion 91A of the cover main body 91 may be fixed to the sensor substrate 21 or provided to the housing 200.

[0062] The opening 92 is formed in a portion of the cover body 91 that comes into contact with the finger Fg to be measured, and emits light emitted by the light source 60 toward the outside of the cover body 91. The opening 92 is a through-hole in the cover body 91 that emits light emitted by the optical sensor 10 to the outside of the housing 200. The opening 92 is formed in the top portion of the cover body 91 that faces the light source 60. The top portion of the cover body 91 is the portion that comes into contact with the finger Fg to be measured. In this embodiment, the opening 92 is formed in a circular shape, but it may also be in the shape of, for example, a rectangle, a triangle, a polygon, or the like. The cover 90 may close the opening 92 with a light-transmitting member.

[0063] The reflective layer 93 is a reflective member provided on the inner surface of the cover main body 91 and capable of reflecting light emitted by the light source 60 and focusing the light on the opening 92. The reflective layer 93 is provided on the inner surface so as to reflect the light emitted by the light source 60. The reflective layer 93 is formed on the inner surface of the cover main body 91 using a highly reflective metal material such as Al or Ag, or a dielectric multilayer film that reflects the light source wavelength range. The reflective layer 93 has a reflectivity of 50% or more. When the reflective layer 93 is totally reflective, the cover main body 91 may be formed of a translucent material. The reflective layer 93 can increase the amount of light emitted from the opening 92 by reflecting the light emitted by the light source 60. Note that if the cover main body 91 is formed of a reflective metal, the reflective layer 93 may be on the inner surface of the cover main body 91.

[0064] 8, the distance D is the distance from the center of the light source 60 to one end of the lower electrode 11 of the nearest photodiode PD. The distance D between the light source 60 and the optical sensor 10 is 5 mm or less. Although the light source 60 and the optical sensor 10 are separated from each other, the distance D can be reduced in the circumferential direction 200C by bringing the optical sensor 10 into contact with the cover 90.

[0065] The multiple wirings 26 of the sensor substrate 21 are connected to the detection circuit 48 of the control circuit 122 via multiple signal lines of the flexible printed circuit board 70. In other words, the detection circuit 48 is electrically connected to the lower electrode 11 of the optical sensor 10 via multiple signal lines. Note that the detection circuit 48 may be formed as a circuit separate from the control circuit 122.

[0066] The detection device 1A includes the control circuit 122 and power supply circuit 123 described in the first embodiment. The control circuit 122 has a detection circuit 48. The detection device 1A detects information about the object to be detected based on detection signals Vdet from multiple photodiodes PD. The control circuit 122 operates using power supplied from the power supply circuit 123.

[0067] The above describes an example of the configuration of the detection device 1A according to embodiment 2. Note that the above configuration described using Figures 8 to 10 is merely an example, and the configuration of the detection device 1A according to this embodiment is not limited to this example. The configuration of the detection device 1A according to this embodiment can be flexibly modified depending on the specifications and operation.

[0068] [Distance between the light source and the optical sensor of the detection device] Next, an example of the action of light in the detection device 1A according to embodiment 2 will be described. Fig. 10 is a cross-sectional schematic diagram showing an example of the configuration of the detection device 1A in the E-E cross section shown in Fig. 8. In the detection device 1A shown in Fig. 10, the distance D between the light source 60 and the optical sensor 10 is 5 mm or less. The detection device 1A is housed in the first housing 210 of the housing 200, with the detection device 1A mounted on the sensor substrate 21 with the optical sensor 10 and the cover 90 close to each other.

[0069] When the light source 60 emits light L1 while the detection device 1A is attached to a finger Fg, the light L1, including light reflected by the reflective layer 93 inside the cover 90, is emitted from the opening 92 of the cover 90 toward the finger Fg. The light L1 enters the interior of the finger Fg through the skin and passes through or is reflected by muscle tissue, arteries Fg-a, and veins Fg-v. The reflected light L2, which is light L1 reflected inside the finger Fg, travels toward the inside of the finger Fg and toward the detection device 1A. When the reflected light L2 is emitted toward the outside of the finger Fg and reaches the optical sensor 10 of the detection device 1A, the photodiode PD of the optical sensor 10 receives the reflected light L2. Furthermore, when the light L1 emitted by the light source 60 travels toward the optical sensor 10 of the detection device 1A, the light L1 is blocked by the cover 90 and is not detected by the optical sensor 10. Furthermore, in the detection device 1A, the cover 90 is pressed against the surface of the finger Fg, and the opening 92 of the cover 90 can be brought close to the artery Fg-a located deep inside the finger Fg, so the luminous flux of the light L1 from the light source 60 can be focused on the artery Fg-a. This allows the detection device 1A to detect information about the inside of a living body such as the finger Fg based on the reflected light L2 received by the photodiode PD of the optical sensor 10, thereby improving the proportion of arterial information.

[0070] In contrast, a case where the detection device 1A does not have the cover 90 will be described. Fig. 11 is a cross-sectional schematic diagram for explaining an example of the action of light in a comparative detection device 1100 according to embodiment 2. The comparative detection device 1100 shown in Fig. 11 has the same basic configuration as the detection device 1A of embodiment 2, but differs from the detection device 1A in that it does not have the cover 90.

[0071] 11, the distance D between the light source 60 and the optical sensor 10 is 5 mm or less (for example, 4 mm). In the comparative detection device 1100, there is no light-blocking object between the light source 60 and the optical sensor 10 on the sensor board 21. When the comparative detection device 1100 is worn on a finger Fg, the light source 60 emits light L1, which passes through the housing 200 and illuminates the finger Fg, with part of the light L1 traveling toward the adjacent optical sensor 10. Therefore, in the comparative detection device 1100, the reflected light L2 reflected by the optical sensor 10 from the finger Fg includes reflected light L5 not reflected by the artery Fg-a and direct light from the light source 60, reducing the accuracy of detecting information about a living body based on the light received by the optical sensor 10.

[0072] The detecting device 1A according to the second embodiment is compared with the comparative detecting device 1100. The detecting device 1A can increase the amount of reflected light L2 reflected by the artery Fg-a from the light source 60, which is part of the light L1 emitted from the light source 60 to the inside of the finger Fg. In contrast, the comparative detecting device 1100 does not include the cover 90, and therefore receives only the reflected light L2 and the reflected light L5 from the light source 60 to the inside of the finger Fg. Therefore, the detecting device 1A can increase the amount of reflected light L2 reflected by the artery Fg-a compared to the comparative detecting device 1100. Furthermore, the detecting device 1A can house the light source 60 and the optical sensor 10 close to each other within the housing 200, thereby improving light utilization efficiency. As a result, even if the distance D between the light source 60 and the optical sensor 10 is set to 5 mm or less, the detecting device 1A can suppress loss of the amount of light reaching the optical sensor 10, thereby improving the accuracy of detecting light from the light source 60 using the ring-shaped housing 200.

[0073] In the detection device 1A, the reflectance of the reflective layer 93 of the cover 90 is 50% or more. This allows the detection device 1A to direct more light emitted by the light source 60 toward the opening 92, thereby increasing the amount of light emitted from the opening 92 of the cover 90 pressed against the finger Fg (living body), thereby improving the detection accuracy of information related to the living body.

[0074] The detection device 1A has an optical sensor 10 that is an organic photodiode, which allows the detection device 1 to detect light reflected by the finger Fg with high accuracy using the optical sensor 10.

[0075] In the detection device 1A, the optical sensor 10 and the light source 60 are provided on a flexible printed circuit board 70, the lower electrode 11 of the optical sensor 10 is electrically connected to the wiring 26, and the wiring 26 is electrically connected to the flexible printed circuit board 70. This allows the detection device 1 to be manufactured with the flexible printed circuit board 70 housed inside the housing 200, thereby improving productivity.

[0076] The detection device 1A has a ring-shaped housing 200. As a result, even if the light source 60 and the optical sensor 10 are provided close to each other inside the ring-shaped housing 200, the cover 90 exists between them, so that the detection device 1 can improve the accuracy of detecting light emitted from the light source 60 toward the finger Fg.

[0077] In the above-described embodiment, the detection device 1, 1A is described as using a ring-shaped housing 200, but is not limited thereto. For example, the detection device 1, 1A may have a card-shaped, band-shaped, or other housing. In this case, the side of the detection device 1, 1A that comes into contact with the housing and the human body is the side illuminated by the light source. Furthermore, the detection device 1, 1A may have an optical sensor implemented by a silicon photodiode.

[0078] In the above-described embodiment, the detection device 1 includes the reflective member 80, and the detection device 1A includes the cover 90. However, the present invention is not limited to this. For example, when a plurality of optical sensors 10 are provided adjacent to the light source 60 in the circumferential direction 200C of the housing 200, one detection device may be configured to include the reflective member 80 and the cover 90 according to the distance D between the light source 60 and the optical sensor 10.

[0079] The components of each of the above-described embodiments can be combined as appropriate. Furthermore, other effects and advantages brought about by the aspects described in the present embodiments that are obvious from the description in this specification or that can be conceived by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0080] 1,1A detection device 10. Optical Sensor 11 Lower electrode 12 Lower buffer layer 13 Active layer 14 Upper buffer layer 15 Upper electrode 21 Sensor board 26 Wiring 27 Insulating layer 60 light source 70 Flexible Printed Circuit Board 80 Reflective material 90 Cover 91 Cover body 92 Opening 93 Reflective layer 200 cabinets 200C circumferential direction 210 1st cabinet 211 Power electrode 212 Connection 220 Second cabinet Fg finger PD photodiode

Claims

1. The housing and a light source provided in the housing so as to be able to illuminate an illumination side outside the housing; an optical sensor provided in the housing so as to be aligned with the light source in a first direction of the housing and capable of detecting light incident from an illumination side of the light source; a reflecting member provided in the housing so as to be disposed between the light source and the optical sensor, the reflecting member being capable of reflecting incident light toward an irradiation side of the light source; Equipped with The distance between the light source and the light sensor is 5 mm or more; The reflecting member has a reflectance of 50% or more, the light source emits any one of near-infrared light, red light, and green light; The optical sensor is an organic photodiode having a sensor substrate, a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode.

2. A housing, a light source provided in the housing so as to be able to illuminate an illumination side outside the housing; an optical sensor provided in the housing so as to be aligned with the light source in a first direction of the housing and capable of detecting light incident from an illumination side of the light source; a reflecting member provided in the housing so as to be disposed between the light source and the optical sensor, the reflecting member being capable of reflecting incident light toward an irradiation side of the light source; Equipped with The photosensor is an organic photodiode having a sensor substrate, a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode. Detection device.

3. The distance between the light source and the light sensor is 5 mm or more. The detection device according to claim 2 .

4. The reflecting member has a reflectance of 50% or more. The detection device according to claim 3 .

5. The housing and a light source provided in the housing so as to be able to illuminate an illumination side outside the housing; an optical sensor provided in the housing so as to be aligned with the light source in a first direction of the housing and capable of detecting light incident from an illumination side of the light source; a cover provided on the housing so as to protrude from the housing while covering the light source; Equipped with The cover is a cover body that protrudes from the housing and is capable of coming into contact with the object to be measured; an opening formed in a portion of the cover body that comes into contact with a measurement object and through which light emitted by the light source is emitted toward the outside of the cover body; a reflective layer provided on the inner surface of the cover body, the reflective layer being capable of reflecting light emitted from the light source and condensing the light onto the opening; Equipped with The optical sensor is an organic photodiode having a sensor substrate, a lower electrode, a lower buffer layer, an active layer, an upper buffer layer, and an upper electrode.

6. The distance between the light source and the light sensor is 5 mm or less. The detection device according to claim 5 .

7. The reflective layer has a reflectance of 50% or more. The detection device according to claim 6.

8. The light source emits any one of near-infrared light, red light, and green light.

8. The detection device according to claim 4 or 7.

9. the light source and the optical sensor are provided on a flexible printed circuit board; the optical sensor is laminated on the sensor substrate in the following order: wiring, an insulating layer, the lower electrode, the lower buffer layer, the active layer, the upper buffer layer, and the upper electrode; The lower electrode is electrically connected to the wiring, and the wiring is electrically connected to the flexible printed circuit board.

6. A detection device according to any one of claims 1, 2 and 5.

10. The housing is formed in a ring shape. The detection device according to claim 9.

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