JP4460566B2 - Optical sensor and biological information measuring device - Google Patents

Description

  The present invention relates to an optical sensor that measures information such as a flow velocity and a flow rate of a fluid using scattered light from a minute scatterer in the fluid, and a biological information measuring device including the optical sensor.

  With the aging of society, there is increasing interest in managing health to prevent lifestyle-related diseases. Biological information measuring device that performs measurement on blood flow using laser light in order to quickly and easily find lifestyle-related diseases such as cerebral thrombosis and myocardial infarction caused by poor blood flow, such as a blood flow meter Has been developed (see, for example, Patent Documents 1 and 2).

  A conventional blood flow meter optical sensor will be described with reference to FIGS. 14, 15, and 16. 14A and 14B show an example of a conventional blood flow meter optical sensor, in which FIG. 14A is a top view and FIG. 14B is a cross-sectional view taken along line A14-A14 '. The conventional optical sensor includes a silicon substrate 221, an electrode 222-1, an electrode 222-2, an electrode 224-1, an electrode 224-2, a light emitting element 223, a light receiving element 225, and a cover substrate 226. The silicon substrate 221 has two concave portions surrounded by an inclined surface, the light emitting element 223 is disposed on one side, and the light receiving element 225 is disposed on the other side. An electrode 222 and an electrode 224 are formed on the silicon substrate 221 from the outside of the recess to the inside of each recess. The light emitting element 223 is connected to the electrode 222-1 and the electrode 222-2, and the light receiving element 225 is connected to the electrode 224-1 and the electrode 224-2. The light emitting element 223 is an edge emitting laser diode, and the light receiving element 225 is a surface incident photodiode. The cover substrate 226 is made of synthetic quartz that transmits light.

  FIG. 15 is a cross-sectional view along B14-B14 '. The light emitting element 223 is bonded to the electrode 222-1 with a solder film. The surface of the light emitting element 223 on the light emitting portion side and the electrode 222-2 are connected by a wire 229. The cover substrate 226 is formed with a binary lens 230 that emits light emitted from the light emitting element 223 upward.

  FIG. 16 is a cross-sectional view taken along the line C14-C14 '. The light receiving element 225 is bonded to the electrode 224-1 with a solder film. The surface of the light receiving element 225 on the light receiving unit side and the electrode 224-2 are connected by a wire 232. A light shielding film 227 is attached to the surface including the inclined surface of the recess where the light receiving element 225 is disposed. On the upper and lower surfaces of the cover substrate 226, a light shielding film 231 that prevents external light from entering the light receiving element 225 is provided. A pinhole 225-1 for allowing scattered light to enter the light receiving element 225 is formed in the light shielding film 231. The light shielding film 231 covers the concave portion where the light receiving element 225 is disposed.

As described with reference to FIGS. 14, 15, and 16, the conventional optical sensor irradiates the external subject with the light from the light emitting element 223 through the binary lens 230, and the scattered light of the light emitted to the subject. Is received by the light receiving element 225 through the pinhole 225-1 formed in the light shielding film 231. The scattered light received by the optical sensor includes reflected light from a stationary living tissue and reflected light from red blood cells (scattering particles) moving in the capillary of the living tissue. The frequency of reflected light by red blood cells is Doppler shifted according to the blood flow, causing interference and interference with stationary biological tissue. A method of measuring biological information such as blood flow volume, blood volume, blood flow velocity, and pulse rate by detecting this interference by heterodyne detection will be described as a Doppler shift method in the following description (for example, see Non-Patent Document 1). ). For example, the blood flow velocity can be measured by frequency analysis of interference light, and the blood flow rate can be measured by the intensity of scattered light. The blood flow velocity can be obtained by dividing the blood flow volume by the blood volume.
JP 2004-229920 A JP 2002-330936 A M.M. D. Stern: In vivo evaluation of microcirculation by coherent light scattering “Nature, Vol. 254, pp. 56-58 (1975)”

  Since the optical sensor of the blood flow meter contains the light emitting element and the light receiving element in the recess of the silicon substrate and is covered with the cover substrate, the recess of the silicon substrate is wet-etched to a depth deeper than the height of the light emitting element and the light receiving element. It was required to etch. Furthermore, the wiring to the concave portion has been required to prevent disconnection at a step in the concave portion. Meeting these requirements complicates the manufacturing process of the optical sensor, and the manufacturing cost of the conventional optical sensor has increased.

  In addition, the optical sensor of the blood flow meter is in contact with the subject so that external light other than scattered light from the subject does not enter. For this reason, the light shielding film of the cover substrate of the optical sensor may be deteriorated and peeled off. The measurement accuracy of the optical sensor was lowered due to the peeling of the light shielding film on the cover substrate.

  Moreover, since the optical sensor of the blood flow meter has a common cover substrate for the light emitting element and the light receiving element, stray light from the light emitting element may pass through the cover substrate and enter the light receiving element. This stray light causes noise in the output signal of the light receiving element, which decreases the measurement accuracy of the optical sensor.

  An object of the present invention is to solve the above-mentioned problems and to provide an optical sensor and a biological information measuring device that can be easily manufactured and have high measurement accuracy.

  In order to achieve the above object, an optical sensor according to the present invention includes a light emitting element and a light receiving element mounted on a single insulating substrate, and only the light receiving element of the light emitting element and the light receiving element has a light shielding property. It is characterized by covering with. The cap for the light receiving element is provided with an incident window through which the scattered light emitted from the light emitting element is scattered and a light deflecting surface for reflecting the light from the light emitting element upward of the insulating substrate.

  Specifically, the optical sensor according to the present invention includes an insulating substrate, a light emitting element mounted on the insulating substrate and emitting light, and mounted on the insulating substrate side by side with the light emitting element. A light receiving element that receives scattered light obtained by scattering the emitted light emitted from the light receiving element, and a light receiving element cap that is formed of a light-shielding member and covers the light receiving element on the insulating substrate. The cap for light is formed with an incident window that allows the scattered light to pass therethrough at a portion that intersects the optical path of the scattered light that is incident on the light receiving element, and the light emitting element is disposed on the side surface on the side where the light emitting element is disposed. A light deflecting surface for deflecting light from the element to the upper side of the insulating substrate is formed.

  The light emitting element and the light receiving element are set on an inexpensive flat insulating substrate provided with an electric wiring pattern, and only the light receiving element is covered with a light receiving element cap. Since the light receiving element cap is formed of a light-shielding member, a light-shielding film forming step like a conventional cover substrate is unnecessary. Furthermore, a process for preventing disconnection of the electric wiring to the light emitting element and the light receiving element is unnecessary. Therefore, the optical sensor according to the present invention can omit the process necessary for manufacturing the conventional optical sensor, and thus can reduce the manufacturing cost.

  Further, since the light receiving element cap is formed of a light shielding member, it is possible to prevent peeling due to deterioration of the light shielding film. For this reason, it is possible to prevent a decrease in measurement accuracy due to peeling of the light shielding film. Further, since the light emitting element is not accommodated in the light receiving element cap and the light deflecting surface is formed on the light receiving element cap, it is possible to prevent the stray light from entering the light receiving element without passing through the subject. Therefore, the optical sensor according to the present invention can reduce signal noise caused by stray light and improve measurement accuracy.

  Therefore, the optical sensor according to the present invention can provide an optical sensor that can be easily manufactured and has high measurement accuracy.

  In the optical sensor according to the present invention, the insulating substrate has an electrical wiring formed on a surface on which the light emitting element and the light receiving element are mounted, the light receiving element cap has conductivity, and the electrical wiring and the It is preferable that the light receiving element cap is in electrical contact directly or via a conductor. The signal of the light receiving element is weak until amplified by an amplifier, and is easily affected by external electromagnetic noise. When the cap for the light receiving element has conductivity, the potential of the cap for the light receiving element can be made the same as that of the light emitting element or the cathode of the light receiving element. As a result, external electromagnetic noise can be prevented and the signal-to-noise ratio of the signal from the light receiving element can be improved.

  In the optical sensor according to the present invention, it is preferable that a protrusion for preventing movement of the light receiving element cap on the insulating substrate is provided at a contact portion of the light receiving element cap with the insulating substrate. When the light receiving element cap is mounted on the insulating substrate, the light receiving element cap is mounted on the insulating substrate by providing a protrusion for preventing the light receiving element cap from moving on the insulating substrate at the contact portion of the light receiving element cap with the insulating substrate. And the relative position of the light deflection surface and the relative position of the light receiving element and the incident window can be easily and accurately adjusted. Since the light emitting element and the light receiving element can be installed close to each other, shallow peripheral circulation blood flow can be observed.

  In the optical sensor according to the present invention, it is preferable that a stage on which the light emitting element is mounted is provided between the light emitting element and the insulating substrate, and the light emitting element emits light toward the light deflection surface. . Since the reflection position on the light deflection surface is the actual light emission position when using the optical sensor, the light emitted from the light emitting element is reflected at a high position from the insulating substrate, so that it is between the light emission position and the light reception position. The distance can be shortened. Since the light emitting position and the light receiving position can be easily brought close to each other, even biological information of a shallow part can be easily obtained.

  In the optical sensor according to the present invention, it is preferable that the light deflection surface is a mirror surface or a diffraction grating. Since it is possible to prevent stray light from being emitted from the light emitting element in the optical sensor and to irradiate the subject with a sufficient amount of light, noise can be reduced.

  In the optical sensor according to the present invention, it is preferable that the light deflection surface deflects light from the light emitting element in a normal direction of a surface of the insulating substrate on which the light emitting element is mounted. Since the deflected light travels perpendicularly from the insulating substrate and the distance between the insulating substrate and the subject changes, the irradiation position of the subject does not depend on the distance from the insulating substrate. Obtainable.

  In the optical sensor according to the present invention, it is preferable that the light emitting element emits light having a wavelength of 0.3 μm or more and 2.0 μm or less. A compound semiconductor with a small size and low power consumption can be used.

  In the optical sensor according to the present invention, it is preferable that the light emitting element emits light having a wavelength of 1.3 μm. The permeability of skin tissue is high, blood flow under the skin can be detected, and a blood flow waveform with a high S / N ratio can be obtained.

  The biological information measuring apparatus according to the present invention calculates any value related to biological information by processing any one of the optical sensors according to the present invention, a light emitting element driving circuit for driving the light emitting element, and a signal from the light receiving element. A biological information calculation circuit. Since any one of the optical sensors according to the present invention is provided, a biological information measuring device that is easy to manufacture and has high measurement accuracy can be provided.

  According to the present invention, an optical sensor and a biological information measuring device according to the present invention include a light receiving element cap that covers only a light receiving element, and includes the light receiving element and the light receiving element on an insulating substrate, and is incident on the light receiving element cap. Since the window and the light deflection surface are provided, the manufacturing can be facilitated by simplifying the process, and the measurement accuracy can be increased by reducing the noise.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a first optical sensor according to the first embodiment, where (a) shows a top view and (b) shows an A1-A1 ′ cross-sectional view. The optical sensor 501 includes an insulating substrate 11, a light receiving element cap 13, a light emitting element 15, and a light receiving element 17.

  The insulating substrate 11 mounts the light emitting element 15 and the light receiving element 17 on the same surface. The insulating substrate 11 is a flat substrate, for example. Since it is not necessary to form a recess for arranging the light emitting element 15 and the light receiving element 17, the light emitting element 15 and the light receiving element 17 can be mounted on the same surface of the flat substrate. Since there is no need to form a recess in the insulating substrate 11, the material of the insulating substrate 11 can be freely selected. For example, the material of the insulating substrate 11 is an insulator such as glass epoxy resin, fluororesin, or ceramic. The insulating substrate 11 may be a silicon substrate having a nitride film or an oxide film laminated on the surface.

  Of the surface of the insulating substrate 11, electrical wirings 21a, 21b, 21c, and 21d are formed on the surface on which the light emitting element 15 and the light receiving element 17 are mounted. Electrical wirings 21 c and 21 d are connected to the light emitting element 15. Electrical wirings 21 a and 21 b are connected to the light receiving element 17. The electrical wirings 21a, 21b, 21c, and 21d are metals that can be wire-bonded, and are, for example, metal films made by plating. The electrical wirings 21a, 21b, 21c, and 21d can be formed by, for example, a known technique for manufacturing a printed circuit board. When the insulating substrate 11 is a silicon substrate, a metal electric wiring pattern can be formed on the surface by a known semiconductor manufacturing method. When the light receiving element cap 13 is formed of a conductive material, an insulating film 25 is preferably provided between the insulating substrate 11 and the light receiving element cap 13.

  The light emitting element 15 is mounted on the insulating substrate 11 and emits light. The light emitting element 15 is, for example, a semiconductor laser. The semiconductor laser is preferably an edge emitting type. The semiconductor laser preferably uses a compound semiconductor. The light emitting element 15 preferably generates light having a wavelength of 0.3 μm to 2.0 μm. In particular, light with a wavelength of 1.3 μm has a higher transmittance of skin tissue and can detect blood flow deep under the skin, compared with light with a wavelength of 780 nm that is often used in conventional commercial products. Flow waveform can be measured.

  The light receiving element 17 is mounted on the insulating substrate 11 and receives scattered light from the outside. The scattered light is scattered light obtained by scattering the outgoing light emitted from the light emitting element 15. The light receiving element 17 is, for example, a photodiode. Since the scattered light is light obtained by scattering the light emitted from the light emitting element 15 within the subject, the type of the photodiode is selected according to the type of the light emitting element 15. The light receiving element 17 receives only light necessary for biological information measurement from the outside through the incident window 19b, converts it into an electrical signal, and outputs it to the electrical wiring 21b. Therefore, the optical sensor 501 outputs an electrical signal corresponding to the light intensity of the scattered light scattered by the external subject from the electrical wiring 21b.

  The light receiving element cap 13 is formed of a light blocking member and covers the light receiving element 17 on the insulating substrate 11. The member having light shielding properties is, for example, opaque plastic or metal. Since the member itself has a light shielding property, it is possible to prevent noise generated by light leakage caused by peeling of the light shielding film. The light receiving element cap 13 is mounted on the insulating substrate 11 so as to cover the light receiving element 17. The position of the light receiving element cap 13 on the insulating substrate 11 is such that light from the light emitting element 15 can irradiate an external subject via the light deflection surface 19a, and light from the outside passes through the incident window 19b and is received. The position where the element 17 can receive light is used. The light receiving element cap 13 prevents the light receiving element 17 from directly receiving the light from the light emitting element 15. The step of bonding the partition plate can be omitted, and the light receiving element cap 13 can be easily manufactured. Furthermore, if a light emitting element cap (not shown) for handling the light emitting element 15 alone is installed, the light emitting element 15 can be prevented from being damaged by an external force. Further, the light receiving element cap 13 and the light emitting element cap (not shown) can be integrated to reduce the manufacturing process.

  The light receiving element cap 13 is formed with an incident window 19b through which scattered light passes. The opening diameter of the incident window 19b is preferably such that outside light does not enter, and is preferably, for example, 100 μm or more and 500 μm or less. Incident light can be blocked from entering the light receiving element 17 and scattered light can be captured. In the present embodiment, description will be made assuming that the thickness is 500 μm. Further, the incident window 19b is provided at a portion that intersects the optical path of the scattered light incident on the light receiving element 17. In the present embodiment, since scattered light is generated above the light deflection surface 19a, an example in which the incident window 19b is formed at the boundary portion between the ceiling portion of the light receiving element cap 13 and the side surface portion on the light emitting element 15 side. Indicated. The incident window 19b may be formed in a ceiling portion of the light receiving element cap 13 or may be formed in a side surface portion of the light receiving element cap 13 on the light emitting element 15 side. Moreover, although the entrance window 19b may be a cavity, a member that is transparent to scattered light may be fitted therein. Since the transparent member is fitted, the light receiving surface of the light receiving element 17 in the light receiving element cap 13 can be protected.

  On the side surface of the light receiving element cap 13 on the side where the light emitting element 15 is disposed, a light deflection surface 19 a for deflecting light from the light emitting element 15 upward of the insulating substrate 11 is formed. Above the insulating substrate 11 is above the substrate surface of the insulating substrate 11 on which the light emitting element 15 is mounted. The light deflection surface 19 a is inclined with respect to the substrate surface of the insulating substrate 11 in order to deflect the light from the light emitting element 15 above the insulating substrate 11. The inclination angle of the light deflection surface 19a is, for example, 10 ° to 80 °. The light deflection surface 19a preferably deflects light from the light emitting element 15 in the normal direction of the substrate surface of the insulating substrate 11 on which the light emitting element 15 is mounted. For example, as shown in FIG. 1, the inclination angle of the light deflection surface 19a is preferably 45 °. When the tilt angle of the light deflection surface 19a is 45 °, the deflected emitted light travels vertically upward from the insulating substrate 11. For this reason, even if the distance between the scatterer in the blood to be irradiated and the insulating substrate 11 changes, there is an advantage that the irradiation position does not depend on the distance from the insulating substrate 11. In particular, the depth of blood vessels from the epidermis varies considerably among individuals due to various factors such as subcutaneous fat. In this case, if the emitted light from the light emitting element 15 can be made perpendicularly incident on the epidermis, the biological information can be stably measured.

  The light deflection surface 19a is preferably a mirror surface or a diffraction grating for deflecting light from the light emitting element 15. When the light receiving element cap 13 is a metal, the mirror surface can be formed by mirror polishing the surface. When the light receiving element cap 13 is made of plastic, the mirror surface can be formed by vapor deposition of gold, which is a highly reflective metal. Since the light deflection surface 19a is the outer surface of the light receiving element cap 13, it is easy to form the light deflection surface 19a. In addition, since the light deflection surface 19a can be formed in advance on the light receiving element cap 13, the manufacturing process of the optical sensor 501 can be simplified.

  The light receiving element cap 13 is preferably conductive. In this case, it is preferable that the electrical wirings 21a, 21b, 21c, 21d and the light receiving element cap 13 are in electrical contact directly or via a conductor. The potential of the light receiving element cap 13 can be the same as that of the light emitting element 15 or the cathode of the light receiving element 17. Thereby, the noise of the light receiving element 17 due to external electromagnetic noise can be prevented, and the SN ratio of the signal from the light receiving element 17 can be improved. For example, a member forming the light receiving element cap 13 is a metal having conductivity. In the present embodiment, the material of the light receiving element cap 13 is described as aluminum. When the light receiving element cap 13 is made of plastic, the surface of the light receiving element cap 13 is covered with a conductive film such as metal. If the light receiving element cap 13 is formed by a plastic injection molding method and the surface is covered with a metal thin film, mass production becomes possible, and the manufacturing cost of the optical sensor 501 can be reduced. Further, the light receiving element cap 13 may be made conductive by making the member forming the light receiving element cap 13 a plastic mixed with conductive particles.

  2, 3, and 4 show specific examples of electric wiring patterns formed on the insulating substrate 11. 2 shows a first pattern of electrical wiring, FIG. 3 shows a second pattern of electrical wiring, and FIG. 4 shows a third pattern of electrical wiring. 2, 3, and 4 indicate the same components as those shown in FIG. 1. 2 and 3, the cathode of the light emitting element 15 is connected to the electric wiring 21c, the anode of the light emitting element 15 is connected to the electric wiring 21d, and the cathode of the light receiving element 17 is connected to the electric wiring 21b. The anode of the light receiving element 17 is connected to the electric wiring 21a. The cathode of the light emitting element 15 is connected to the electric wiring 21c via a solder film. The anode of the light emitting element 15 is connected to the electric wiring 21 d by a wire 23. The cathode of the light receiving element 17 is connected to the electric wiring 21b via a solder film. The anode of the light receiving element 17 is connected to the electric wiring 21 a by a wire 23. In FIG. 2, the light receiving element cap 13 has conductivity, and the electrical wiring 21 b and the light receiving element cap 13 are in contact with each other, so that the cathode of the light receiving element 17 and the light receiving element cap 13 have the same potential. can do. In FIG. 3, the light receiving element cap 13 has conductivity, and the electrical wiring 21 c and the light receiving element cap 13 are in contact with each other, so that the cathode of the light emitting element 15 and the light receiving element cap 13 have the same potential. can do.

  The electric wiring pattern shown in FIG. 4 does not have the electric wiring 21b and the electric wiring 21c, but mounts the electric wiring 21e in which the cathodes of the light emitting element 15 and the light receiving element 17 are in common contact. The light receiving element cap 13 has conductivity, and the electrical wiring 21e and the light receiving element cap 13 are in contact with each other, so that the cathodes of the light emitting element 15 and the light receiving element 17 and the light receiving element cap 13 have the same potential. Become. The cathode of the light emitting element 15 and the cathode of the light receiving element 17 are connected to the electric wiring 21e via a solder film. The anode of the light emitting element 15 is connected to the electric wiring 21 d by a wire 23. The anode of the light receiving element 17 is connected to the electric wiring 21 a by a wire 23.

  2, 3, and 4, when the light receiving element cap 13 has conductivity, the light receiving element cap 13 and the electric wirings 21 a, 21 b, 21 c, 21 d, and 21 e are not electrically connected to each other. The contact portion between the light receiving element cap 13 and each of the electrical wirings 21a, 21b, 21c, 21d, and 21e is preferably covered with an insulating film such as a resist (reference numeral 25 in FIG. 1). When the light receiving element cap 13 is not conductive, the insulating film 25 is unnecessary.

  The optical sensor 501 shown in FIG. 1 is supplied with current from an external drive circuit (not shown) to the electrical wirings 21 a, 21 b, 21 c, 21 d, and 21 e to which the anode of the light emitting element 15 is connected. The light emitting element 15 emits light when current flows from the electrical wiring 21 connected to the drive circuit to the drive circuit, and light can be irradiated to an external subject through the light deflection surface 19a. In order to reduce the light reflected from the light receiving element cap 13 among the light from the light emitting element 15, the side of the light receiving element cap 13 that covers the light receiving element 17 (the inside of the light receiving element cap 13) is also an antireflection film. May be attached.

  As described above, the optical sensor 501 does not require the insulating substrate 11 to be etched and does not require the formation of a light shielding film on the light receiving element cap 13. Furthermore, since there is no step in the insulating substrate 11, it is easy to form an electric wiring pattern on the insulating substrate 11. Accordingly, the light emitting element 15 and the light receiving element 17 are mounted on the inexpensive flat insulating substrate 11 provided with the electrical wiring pattern, and the light receiving element cap 13 is only mounted so as to cover the light receiving element 17. The sensor 501 can be manufactured at low cost.

  Further, in the optical sensor 501, since the light receiving element cap 13 itself has a light shielding property, there is no peeling due to deterioration of the light shielding film, and there is no decrease in measurement accuracy. Further, since the light receiving element cap 13 is opaque, the light from the light emitting element 15 does not pass through the cover substrate unlike the conventional cover substrate, and the optical sensor 501 detects the subject received by the light receiving element 17. Light that does not pass through can be reduced. Therefore, the optical sensor 501 can measure the biological information of the subject with high accuracy.

  5A and 5B are schematic configuration diagrams of the second optical sensor according to the first embodiment, where FIG. 5A is a top view and FIG. 5B is a cross-sectional view taken along line A5-A5 ′. The difference between the optical sensor 505 and the optical sensor 501 in FIG. 1 is that the surface of the electrical wiring 21 b of the optical sensor 505 is not covered with the insulating film 25. In FIG. 5, the same reference numerals as those used in FIG. 1 denote the same components. In addition, an electrical wiring pattern shown in FIG. 2 is formed on the insulating substrate 11. Since the surface of the electric wiring 21b is not covered with the insulating film 25, the light receiving element cap 13 and the electric wiring 21b are in contact with each other. Since the light receiving element cap 13 has the same potential as the cathode of the light receiving element 17, it has the effect of preventing extraneous electromagnetic noise. Since the signal output from the light receiving element 17 is very weak until it is amplified by the amplifier, it is easily affected by external electromagnetic noise. Therefore, the SN ratio of the signal from the light receiving element 17 can be improved by bringing the electric wiring 21b and the light receiving element cap 13 into contact with each other. The optical sensor 505 can be manufactured at a low cost similarly to the optical sensor 501 of FIG. 1, and biological information can be measured with higher accuracy than the optical sensor 501 due to the effect of preventing electromagnetic noise of the light receiving element cap 13.

  6A and 6B are schematic configuration diagrams of a third optical sensor according to the first embodiment, in which FIG. 6A is a top view and FIG. 6B is a cross-sectional view along A6-A6 ′. An optical sensor 506 shown in FIG. 6 is further provided with a light-emitting element cap 13-1 that is formed of a light-shielding member and covers the light-emitting element 15 on the insulating substrate 11 in addition to the optical sensor 501 shown in FIG. In FIG. 6, the same reference numerals as those used in FIG. 1 denote the same components. The light emitting element cap 13-1 is opaque, and the same material as the light receiving element cap 13 can be used. Of the side surfaces of the light emitting element cap 13-1, an opening for allowing the emitted light from the light emitting element 15 to pass is formed on the side surface disposed on the light deflection surface 19 a side. Since the light-emitting element cap 13-1 having one open side surface is provided on the light-emitting element 15, the light from the light-emitting element 15 is emitted to the outside without any trouble, and an unexpected shock from the outside to the light-emitting element 15. For example, an effect of protecting the light emitting element 15 from an accident such as electrical or structural damage caused by touching the skin can be obtained.

  In the optical sensor 506 shown in FIG. 6, the surface of both the electric wiring 21b and the electric wiring 21c is covered with the insulating film 25. However, the surface of either the electric wiring 21b or the electric wiring 21c or the electric wiring is shown. The surfaces of 21b and the electrical wiring 21c may not be covered with the insulating film 25. Electromagnetic noise to the light receiving element 17 can be reduced by bringing the light receiving element cap 13 into contact with the electric wiring 21b or the electric wiring 21c. Even in this case, the same effect as that described in the optical sensor 505 in FIG. 5 can be obtained.

  Furthermore, the insulating substrate 11 may be mounted with the electrical wiring pattern shown in FIG. In this case, as described with reference to the optical sensor 501 in FIG. 1, the contact portion between the electrical wirings 21 a, 21 d, and 21 e and the light receiving element cap 13 may be covered with the insulating film 25. The optical sensor of the insulating substrate 11 on which the electric wiring pattern of FIG. 4 is mounted can obtain the same effect as the optical sensor 501 of FIG. On the other hand, as described with reference to the optical sensor 505 in FIG. 5, the surface of the electric wiring 21 b may not be covered with the insulating film 25 and may be brought into contact with the light receiving element cap 13. The optical sensor of the insulating substrate 11 on which the electric wiring pattern of FIG. 4 is mounted can obtain the same effect as the optical sensor 505 of FIG.

  7A and 7B are schematic configuration diagrams of a fourth optical sensor according to the first embodiment. FIG. 7A is a top view and FIG. 7B is a cross-sectional view taken along line A7-A7 '. The optical sensor 507 shown in FIG. 7 includes an integrated cap 13-2 in which the light receiving element cap 13 shown in FIG. 6 and the light emitting element cap 13-1 shown in FIG. 6 are integrated. 7, the same reference numerals as those used in FIG. 1 denote the same components.

  The integrated cap 13-2 is opaque, and the same material as the light receiving element cap 13 can be used. A space surrounded by the integrated cap 13-2 and the insulating substrate 11 is divided into a small chamber in which the light emitting element 15 is accommodated and a small chamber in which the light receiving element 17 is accommodated by the light deflection surface 19a. By integrating the light receiving element cap 13 and the light emitting element cap 13-1, there is an advantage that the mounting effort is reduced by one.

(Embodiment 2)
8A and 8B are schematic configuration diagrams of a first optical sensor according to the second embodiment. FIG. 8A shows a circuit board, FIG. 8B shows an example of a cross section A8-A8 ′, and FIG. FIG. The optical sensor 508 shown in FIG. 8 is provided with a protrusion 123 that prevents the light receiving element cap 13 from moving on the insulating substrate 11 at the contact portion of the light receiving element cap 13 shown in FIG. . The insulating substrate 11 has a protrusion insertion port 121 into which the protrusion 123 is inserted. 8, the same reference numerals as those used in FIG. 1 denote the same components.

  The protrusion 123 is disposed at a location in contact with the insulating substrate 11 of the light receiving element cap 13. For example, the protrusion 123 is provided on the light receiving element cap 13, and the light receiving element cap 13 is prevented from moving on the insulating substrate 11 by being inserted into the protrusion insertion port 121 provided on the insulating substrate 11. For this reason, the protrusion 123 is formed of a material that does not deform. For example, metal or hard plastic. The protrusion 123 may be formed of the same material as the light receiving element cap 13. The protrusion 123 can be formed simultaneously with the formation of the light receiving element cap 13. Further, the protrusion 123 may be formed on the insulating substrate 11.

  The protrusion 123 is preferably provided at a corner portion of the light receiving element cap 13 in a portion where the light receiving element cap 13 and the insulating substrate 11 are in contact with each other. For example, in FIG. 8A, the surface of the light receiving element cap 13 that is in contact with the insulating substrate 11 (hereinafter referred to as “the surface of the light receiving element cap 13 that is in contact with the insulating substrate 11”) (Abbreviated as “back surface of cap 13”). The shape is rectangular. The protrusions 123 are arranged at the corners of the back surface of the rectangular light receiving element cap 13. The back surface shape of the light receiving element cap 13 is not limited to a rectangle. By disposing the protrusion 123 at the corner of the back surface of the light receiving element cap 13, the light receiving element cap 13 can be easily manufactured, and the strength of the protrusion 123 is increased.

  The protrusion 123 is inserted into the protrusion insertion port 121 when the light receiving element cap 13 is mounted on the insulating substrate 11. The protrusion insertion port 121 has an opening diameter that allows the protrusion 123 to be inserted. The protrusion insertion port 121 is disposed on the insulating substrate 11 at a position where the protrusion 123 is positioned when the light receiving element cap 13 is mounted. FIG. 8C shows an example of a place where the protrusion 123 is arranged. In addition, the protrusion insertion port 121 does not need to penetrate the insulating substrate 11, and the surface on which the light emitting element 15 and the light receiving element 17 of the insulating substrate 11 are mounted (hereinafter referred to as “light emitting element 15 of the insulating substrate 11 and The “surface on which the light receiving element 17 is mounted” may be abbreviated as “the surface of the insulating substrate 11”).

  FIG. 8B schematically shows a cap mounting process for mounting the light receiving element cap 13 on the insulating substrate 11. When the light receiving element cap 13 is mounted on the insulating substrate 11, the protrusion 123 of the light receiving element cap 13 is inserted into the protrusion insertion port 121 of the insulating substrate 11. The relative position can be adjusted easily and with high accuracy. Furthermore, since the positional accuracy of the protrusion 123 and the positional accuracy of the protrusion insertion port 121 are higher than the alignment accuracy of a human or a mounting machine in the cap mounting process, the position reproduction between the light receiving element cap 13 and the insulating substrate 11 is performed in the cap mounting process. Can increase the sex. Therefore, the relative position between the light receiving element 17 and the incident window 19b and the relative position between the light emitting element 15 and the light deflection surface 19a can be adjusted easily and with high accuracy, so that the measurement accuracy of the optical sensor 508 can be adjusted between the optical sensors 508. Can be kept constant. Therefore, it is possible to provide an optical sensor 508 that can be manufactured at low cost and can measure biological information with high accuracy.

  9A and 9B are schematic configuration diagrams of a second optical sensor according to the second embodiment, where FIG. 9A shows a circuit board, FIG. 9B shows an example of a cross section A9-A9 ′, and FIG. The pick-up figure of a cap is shown. The optical sensor 509 shown in FIG. 9 includes an integrated cap 13-2 instead of the light receiving element cap 13 shown in FIG. Moreover, the protrusion 123 is arrange | positioned in the position of the both ends of the optical deflection surface 19a of the integrated cap 13-2. The protrusion insertion port 121 is the same as the protrusion insertion port 121 shown in FIG.

  10A and 10B are schematic configuration diagrams of a third optical sensor according to the second embodiment, where FIG. 10A shows a circuit board, FIG. 10B shows an example of a cross section A10-A10 ′, and FIG. The pick-up figure of a cap is shown. An optical sensor 510 shown in FIG. 10 includes an integrated cap 13-2 instead of the light receiving element cap 13 shown in FIG. Further, the protrusions 123 shown in FIG. 8 are disposed at both ends of the light deflection surface 19a of the integrated cap 13-2 and at the four corners of the integrated cap 13-2. The protrusion insertion port 121 is the same as the protrusion insertion port 121 shown in FIG.

  The optical sensor 508 shown in FIG. 8, the optical sensor 509 shown in FIG. 9, and the optical sensor 510 shown in FIG. 10 accurately place the light deflection surface 19 a between the light emitting element 15 and the light receiving element 17. Can do. Therefore, the optical sensor 510 can accurately determine the position of the light deflection surface 19a. The optical sensor 508 shown in FIG. 8, the optical sensor 509 shown in FIG. 9, and the optical sensor 510 shown in FIG. 10 have little variation in the light deflection surface 19a, so that the light emitting element 15 and the light receiving element 17 are placed close to each other. Can do. Since it is known that a deep region is observed when the distance between the light emitting element 15 and the light receiving element 17 is long, and a shallow region is observed when the distance is short, the optical sensor 508 shown in FIG. 8 and the optical sensor 509 shown in FIG. And the optical sensor 510 shown in FIG. 10 can observe shallow peripheral circulation blood flow.

(Embodiment 3)
11A and 11B are schematic configuration diagrams for explaining the first optical sensor according to the third embodiment. FIG. 11A is a top view of the first optical sensor according to the third embodiment, and FIG. 11B is A11a. -A11a 'sectional drawing is shown, (c) shows the top view of the 1st optical sensor which concerns on Embodiment 1, (b) shows A11c-A11c' sectional drawing. In the present embodiment, an example is shown in which the electrical wiring pattern shown in FIG. 4 is formed on the insulating substrate 11 and the insulating film 25 for preventing the electrical wiring 21a from contacting the light receiving element cap 13 is provided. The optical sensor 511 shown in FIGS. 11A and 11B is provided with a stage 15b on which the light emitting element 15 is mounted between the light emitting element 15 and the insulating substrate 11, and the light emitting element 15 has an optical deflection surface. Light is emitted toward 19a. By increasing the height of the light source position of the light emitting element 15, the reflection position of the light deflection surface 19 a becomes closer to the light receiving element 17. The distance La between the emission position of the emitted light from the optical sensor 511 and the incident window 19b is shorter than the distance Lc when the table 15b is not provided. When viewed from above, the reflected position of the emitted light is the actual light emitting position. Therefore, when viewed from above, the distance between the light emitting position and the light receiving position of the light receiving element 17 on the projection plane parallel to the insulating substrate 11 is more. Equivalent to being close. The distance between the light emitting position and the light receiving position acquires biological information, and the longer the distance is, the deeper the biological information can be acquired. If it is desired to obtain biological information of a shallow portion from the surface, biological information at a desired depth can be obtained by using this embodiment.

(Embodiment 4)
FIG. 12 is a configuration diagram illustrating an example of a biological information measuring apparatus. A biological information measuring device 801 illustrated in FIG. 12 includes an optical sensor 201, a preamplifier 202, a drive arithmetic device 203, and an output unit 204 that displays the obtained blood flow and the like. The biological information measuring device 801 is a device that measures various information of a fluid using scattered light from light scattering particles in the fluid. The various information in the fluid is, for example, blood flow volume, blood flow velocity, pulse, blood pressure, sugar content. The fluid information is preferably a value relating to biological information such as blood flow volume, blood flow velocity, pulse or blood pressure. In this embodiment, the case where the biological information measuring device 801 is a blood flow meter will be described. In the following description, reference numerals used in FIGS. 1 to 11 are also used.

  The optical sensor 201 applies light to a subject located outside the biological information measuring device 801 and receives scattered light scattered in the subject. The optical sensor 201 is, for example, the optical sensor described with reference to FIGS. The optical sensor 201 may be integrated and formed on a semiconductor substrate included in the biological information measuring device 801. The output unit 204 displays data output from the interface 209. The output unit 204 is, for example, a liquid crystal display.

  The drive arithmetic device 203 drives the optical sensor 201, processes signals output from the optical sensor 201, calculates various fluid information, and outputs the calculation result to the output unit 204. In the present embodiment, as an example of measuring the blood flow, the drive arithmetic device 203 drives the light emitting element 15 of the optical sensor 201 and calculates the blood flow by analyzing the scattered light received by the light receiving element 17. Indicates. The drive calculation device 203 includes an A / D converter 205, a light emitting element drive circuit 206, a biological information calculation circuit 207, a power supply unit 208, an interface 209, a signal adjustment circuit 210, and a display unit 211. The drive arithmetic unit 203 can be configured as an LSI as a whole.

  The light emitting element driving circuit 206 is connected to the preamplifier 202 and supplies power to the optical sensor 201 through the preamplifier 202. That is, the light emitting element 15 of the optical sensor described with reference to FIGS. 1, 5, 6, 7, 8, and 9 is turned on and off according to instructions from the light emitting element driving circuit 206. The signal adjustment circuit 210 extracts a specific frequency range including the frequency of the interference component from the analog signal output from the preamplifier 202. The A / D converter 205 performs analog-digital conversion on the signal from the signal adjustment circuit 210 and outputs a digital signal. For example, the A / D converter 205 samples the input analog signal at a predetermined frequency, quantizes it, and outputs it. The sampling frequency is, for example, 200 kHz when measuring the blood flow rate of the subject. The biological information calculation circuit 207 processes the input digital signal according to a predetermined rule. The biological information calculation circuit 207 is a digital signal processor, for example. Since the biological information arithmetic circuit 207 can process a large amount of digital signal data at high speed, the result of processing the input digital signal can be output in real time. The biological information calculation circuit 207 performs a calculation for obtaining biological information such as blood flow from the signal from the A / D converter 205. The interface 209 is an electric circuit that converts an input signal into a signal of a predetermined plan so that the drive arithmetic device 203 and an external peripheral device can communicate with each other. For example, the interface 209 can convert an input signal into an RS-232C standard signal.

  The power supply unit 208 is an electric circuit that supplies power of a predetermined voltage to the outside. A circuit for converting alternating current into direct current, a voltage conversion circuit, and a voltage stabilization circuit are included. Further, the power supply unit 208 may be a battery. The power supply unit 208 supplies power to the A / D converter 205, the light emitting element driving circuit 206, the biological information calculation circuit 207, the interface 209, the signal adjustment circuit 210, and the display unit 211 through an electric wire (not shown).

  The biological information measuring device 801 measures biological information such as blood flow of the subject as follows. The optical sensor 201 that is a sensor chip and the preamplifier 202 are brought close to or in contact with a subject that is a measurement location such as a blood flow. The optical sensor 201 irradiates the subject with light and receives scattered light from the subject. The light emitting element 15 emits irradiated light when current is injected from the light emitting element driving unit 206. Irradiation light from the light emitting element 15 is reduced to a diameter necessary for blood flow measurement by the light deflection surface 19a of the light receiving element cap 13, and is irradiated to the subject. The light emitted from the light deflection surface 19 a is scattered in the subject, and the scattered light reaches the optical sensor 201. Scattered light becomes only light necessary for measurement at the incident window 19 b of the cap 13 and is received by the light receiving element 17.

  The light receiving element 17 receives scattered light, photoelectrically converts it, and outputs it as a scattered light intensity signal. The preamplifier 202 that has received the scattered light intensity signal amplifies the scattered light intensity signal and outputs an analog signal. The signal adjustment circuit 210 extracts a specific frequency including the frequency of the interference component from the analog signal output from the preamplifier 202. The A / D converter 205 converts the signal from the signal adjustment circuit 210 from analog to digital and outputs a digital signal.

  The biological information calculation circuit 207 performs signal processing of the digital signal of the scattered light intensity signal and performs frequency analysis of the interference component of the scattered light. Specifically, the frequency of the interference component of the scattered light S corresponds to the blood flow velocity, the intensity of the scattered light S corresponds to the moving blood flow volume, and the blood flow volume is calculated by the product of the blood flow speed and the blood volume. Desired. Further, the waveform of the scattered light intensity signal includes a modulation component due to the pulse, and the pulse can be detected. The biological information calculation circuit 207 outputs the subject information, which is the result of the frequency analysis of the scattered light intensity signal, as the subject information signal.

  The display unit 211 receives the subject information signal from the biological information calculation circuit 207 and displays the subject information. In addition, the interface 209 converts the subject information signal into a signal that is determined by the standard and used for communication with other devices, such as a wired signal such as the USB standard or the RS-232C standard, the Bluetooth (registered trademark) standard, It is converted into a wireless signal such as ZigBee (registered trademark) standard and output to the output unit 204. As described above, the biological information measuring device 801 can measure biological information such as blood flow.

  FIGS. 13A and 13B are graphs showing blood flow measurement results, where FIG. 13A shows the measurement results obtained by the biological information measuring device, and FIG. 13B shows the measurement results obtained by the conventional blood flow meter. A conventional blood flow meter measurement method uses the Doppler shift method. The living body information measuring device 801 and a conventional blood flow meter are placed adjacent to each other and applied to a finger, blood is blocked by tightening the wrist strongly, the wrist is gradually released, and finally the blood flow is completely released. The time change was measured simultaneously.

  Comparing FIG. 13 (a) and FIG. 13 (b), the increase / decrease tendency of the blood flow volume itself is consistent between the biological information measuring device 801 and the conventional blood flow meter. Although the display value in FIG. 13A is an arbitrary unit, there is no problem because it can be adjusted to the conventional blood flow display value shown in FIG. 13B by using an appropriate linear function conversion formula.

  A conventional blood flow meter couples light from a light emitting element to an optical fiber and irradiates a subject with light output from the optical fiber. Further, in the conventional blood flow meter, scattered light scattered by the subject is received by another optical fiber and coupled to the light receiving element. Since the optical propagation mode of the optical fiber changes due to a change in the bending method or vibration during measurement, it is necessary to limit the operation of the subject when measuring biological information with a conventional blood flow meter. Since the biological information measuring device 801 does not use an optical fiber, it can measure accurate biological information without restricting the operation of the subject. Furthermore, since the biological information measuring device 801 uses the optical sensor described with reference to FIGS. 1 to 12, biological information can be measured with high accuracy, and the manufacturing cost can be reduced.

  The optical sensor and the biological information measuring device of the present invention can be applied to health appliances for health maintenance and health diagnosis. Further, the subject is not limited to a human but may be an animal or a plant. Furthermore, since the flow rate of the liquid flowing inside the tube can be measured as long as it is a tube that can transmit light from the light emitting element, such as a fluororesin tube and a silicon tube, the optical sensor and the biological information measuring device of the present invention are semiconductors. It can be used for flow meters in manufacturing equipment and cooling equipment.

FIG. 2 is a schematic configuration diagram of a first optical sensor according to the first embodiment, where (a) shows a top view and (b) shows an A1-A1 ′ sectional view. It is a schematic diagram which shows the 1st pattern of electrical wiring. It is a schematic diagram which shows the 2nd pattern of electrical wiring. It is a schematic diagram which shows the 3rd pattern of electrical wiring. FIG. 3 is a schematic configuration diagram of a second optical sensor according to the first embodiment, where (a) shows a top view and (b) shows an A5-A5 ′ sectional view. FIG. 4 is a schematic configuration diagram of a third optical sensor according to the first embodiment, where (a) shows a top view and (b) shows an A6-A6 ′ sectional view. FIG. 4 is a schematic configuration diagram of a fourth optical sensor according to the first embodiment, where (a) shows a top view and (b) shows an A7-A7 'sectional view. FIG. 5 is a schematic configuration diagram of a first optical sensor according to Embodiment 2, wherein (a) shows a circuit board, (b) shows an example of an A8-A8 ′ cross section, and (c) is a pickup of a light receiving element cap. The figure is shown. It is a schematic block diagram of the 2nd optical sensor which concerns on Embodiment 2, (a) shows a circuit board, (b) shows an example of A9-A9 'cross section, (c) is a pick-up figure of an integrated cap. Indicates. It is a schematic block diagram of the 3rd optical sensor which concerns on Embodiment 2, (a) shows a circuit board, (b) shows an example of A10-A10 'cross section, (c) is a pick-up figure of an integrated cap. Indicates. It is a schematic block diagram for demonstrating the 1st optical sensor which concerns on Embodiment 3, (a) shows the top view of the 1st optical sensor which concerns on Embodiment 3, (b) is A11a-A11a 'cross section. FIG. 4C is a top view of the first optical sensor according to the first embodiment, and FIG. 4B is a cross-sectional view taken along line A11c-A11c ′. It is a block diagram which shows an example of a biometric information measuring device. It is a graph which shows the measurement result of a blood flow rate, (a) shows the measurement result by a biological information measuring device, (b) shows the measurement result by the conventional blood flow meter. It is an example of the optical sensor of the conventional blood flow meter, (a) is a top view, (b) is A14-A14 'sectional drawing. It is B14-B14 'sectional drawing. It is C14-C14 'sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Insulating board 13 Cap for light receiving elements 13-1 Cap for light emitting elements 13-2 Integrated cap 15 Light emitting element 15b Base on which light emitting elements are mounted 17 Light receiving element 19a Light deflection surface 19b Incident window 21a, 21b, 21c, 21d, 21e Electrical wiring 23 Wire 25 Insulating film 121 Protrusion insertion port 123 Protrusion 201 Optical sensor 202 Preamplifier 203 Drive arithmetic unit 204 Output unit 205 A / D converter 206 Light emitting element driving circuit 207 Biological information arithmetic circuit 208 Power supply unit 209 Interface 210 Signal Conditioning Circuit 211 Display Unit 221 Silicon Substrate 222-1, 222-2, 224-1, 224-2 Electrode 223 Light Emitting Element 225 Light Receiving Element 225-1 Pinhole 226 Cover Substrate 227, 231 Light Shielding Film 229 Wire 230 Binary 'S 232 wire 501,505,506,507,508,509,510,511 optical sensor 801 biological information measurement device

Claims (9)

An insulating substrate;
A light emitting element mounted on the insulating substrate and emitting light;
A light receiving element that is mounted on the insulating substrate along with the light emitting element and receives scattered light obtained by scattering the emitted light emitted from the light emitting element;
A light-receiving element cap that is formed of a light-shielding member and covers the light-receiving element on the insulating substrate;
The light receiving element cap has an incident window that allows the scattered light to pass therethrough at a portion that intersects the optical path of the scattered light that is incident on the light receiving element, and is provided on a side surface on the side where the light emitting element is disposed. An optical sensor, wherein an optical deflection surface for deflecting light from the light emitting element to the upper side of the insulating substrate is formed. The insulating substrate has an electrical wiring formed on a surface on which the light emitting element and the light receiving element are mounted,
The light receiving element cap has conductivity,
The optical sensor according to claim 1, wherein the electrical wiring and the light receiving element cap are in electrical contact with each other directly or through a conductor.   3. The optical device according to claim 1, wherein a protrusion that prevents movement of the light receiving element cap on the insulating substrate is provided at a contact portion of the light receiving element cap with the insulating substrate. Sensor. A stand for mounting the light emitting element is provided between the light emitting element and the insulating substrate,
The optical sensor according to claim 1, wherein the light emitting element emits light toward the light deflection surface.   The optical sensor according to claim 1, wherein the light deflection surface is a mirror surface or a diffraction grating.   The said light deflection surface deflects the light from the said light emitting element in the normal line direction of the surface in which the said light emitting element is mounted among the said insulated substrates. Optical sensor.   The optical sensor according to claim 1, wherein the light emitting element emits light having a wavelength of 0.3 μm or more and 2.0 μm or less.   The optical sensor according to claim 1, wherein the light emitting element emits light having a wavelength of 1.3 μm. An optical sensor according to any one of claims 1 to 8,
A light emitting element driving circuit for driving the light emitting element;
A biological information measuring device comprising: a biological information calculation circuit that processes a signal from the light receiving element and calculates a value related to biological information.

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