JP5301618B2 - Optical sensor and sensor chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sensor and a sensor chip which can be easily manufactured and with which the low cost and the high accuracy can be achieved. <P>SOLUTION: A light generating element is of a surface light generating type which generates emission light in a normal direction of an insulation substrate. A light receiving element is of a front surface incident type which receives scattered light from a horizontal direction with respect to a surface of the insulation substrate at a front surface. A cap is further provided with a light path conversion element which converts the direction of the emission light of the light generating element into the horizontal direction with respect to the surface of the insulation substrate. A first opening of the cap exists in an optical path direction converted by the light path conversion element of the cap with respect to the emission light of the light generating element. A second opening of the cap exists in a direction in which the light receiving element can receive the scattered light with respect to the light receiving element. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

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

  With the aging of society, there is increasing interest in managing health to prevent lifestyle-related diseases. A biological information measuring device, for example, a blood flow meter, that measures blood flow using laser light in order to quickly and easily find lifestyle-related diseases such as cerebral thrombosis and myocardial infarction caused by blood flow deterioration It has been developed (see, for example, Patent Document 1 and Patent Document 2).

  22 and FIG. 23 are diagrams showing the configuration of the optical sensor of the conventional blood flow meter shown in Patent Document 1, FIG. 22 (a) is a top view, and FIG. 22 (b) is an A- in FIG. 22 (a). FIG. 23A is a sectional view taken along the line BB ′ of FIG. 22A, and FIG. 23B is a sectional view taken along the line CC ′ of FIG. 22A. As shown in FIGS. 22A and 22B, the conventional optical sensor includes a silicon substrate 321, an electrode 322, an electrode 324, a laser diode 361, a photodiode 325, and a cover substrate 326.

  The silicon substrate 321 has two recesses surrounded by an inclined surface. An electrode 322 and an electrode 324 are formed on the silicon substrate 321 from the outside of the recess to the inside of the recess. The laser diode 361 is a surface emitting laser diode, and the photodiode 325 is a surface incident type photodiode. The cover substrate 326 is made of synthetic quartz that transmits light. As shown in FIG. 23, the cover substrate 326 has a refractive lens 362 and a light shielding film 331. The light shielding film 331 has pinholes formed on both surfaces of the cover substrate 326 and allowing light to pass through the cover substrate.

The laser diode 361 is disposed in one of the concave portions of the silicon substrate 321. The laser diode 361 is bonded to the electrode 322 with a solder film (not shown). Furthermore, the light emitting portion side surface of the laser diode 361 and the electrode 322 are connected by a wire 329.
Similarly, the photodiode 325 is also arranged on the other side of the concave portion of the silicon substrate 321 and connected to the electrode 324. A light shielding film 327 is affixed to the surface including the inclined surface of the recess where the photodiode 325 is disposed.

  As shown in FIG. 23, the cover substrate 326 is disposed on the silicon substrate 321 so that the refractive lens 362 covers the recess where the laser diode 361 is disposed and the light shielding film 331 covers the recess where the photodiode 325 is disposed. .

  As shown in FIG. 23A, the conventional optical sensor irradiates light from the laser diode 361 to an external subject through the refractive lens 362 of the cover substrate 326. On the other hand, as shown in FIG. 23B, the conventional optical sensor receives the scattered light of the light irradiated to the subject by the photodiode 325 through the pinhole formed in the light shielding film 331.

  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 from red blood cells is Doppler shifted according to the blood flow, causing interference with the reflected light from stationary biological tissue. By detecting the interference (heterodyne detection), biological information such as blood flow volume, blood volume, blood flow velocity, and pulse can be measured. Thus, a method for measuring biological information using light interference will be described as a Doppler shift method in the following description. The measurement principle of the Doppler shift method is described in Non-Patent Document 1, for example. Specifically, the blood flow velocity can be measured by frequency analysis of the interference light, and the blood flow rate can be measured by the intensity of the scattered light. Further, the blood flow volume is obtained by the product of the blood flow velocity and the blood volume.

JP 2004-229920 A JP 2002-330936 A

M.M. D. Stern: “In vivo evolution of microcirculation by coherent light scattering” Nature, vol. 254, pp. 56-58 (1975)

  However, since the optical sensor of the blood flow meter is in contact with the subject, if the light shielding film on the cover substrate of the optical sensor is deteriorated and peeled off, the measurement accuracy is lowered. For this reason, the light-shielding film is required to have such durability that it does not deteriorate and peel off even when it comes into contact with the subject. Further, since the laser diode and the photodiode are accommodated in the concave portion of the silicon substrate and covered with the cover substrate, the concave portion of the silicon substrate is required to be etched by wet anisotropic etching to a depth deeper than the height of the laser diode and the photodiode. . Furthermore, the wiring to the concave portion has been required to prevent disconnection at a step in the concave portion. In order to satisfy these requirements, the manufacturing process of the optical sensor becomes complicated, and the conventional optical sensor has a problem that the manufacturing cost increases.

  On the other hand, the laser diode and the photodiode share the same cover substrate, and a part of the light from the laser diode passes through the cover substrate, and the laser diode receives the light so that the output signal of the laser diode Was producing noise. The conventional optical sensor has a problem that the noise must be reduced in order to measure biological information with high accuracy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical sensor and a biological information measuring apparatus that can be easily manufactured at low cost and can perform high-accuracy measurement.

  In order to achieve the above object, an optical sensor according to the present invention covers a light emitting element and a light receiving element mounted on an insulating substrate with a cap having two openings through which light passes.

  Specifically, the present invention includes a light emitting element that generates outgoing light to the outside, a light receiving element that receives scattered light from the outside, an insulating substrate on which the light emitting element and the light receiving element are mounted, And an opaque cap that covers the light emitting element and the light receiving element on an insulating substrate, wherein the cap allows a part of the light emitted from the light emitting element to pass outside the optical sensor. An optical sensor comprising: a first opening and a second opening for allowing the light receiving element to receive a part of the scattered light scattered from outside the optical sensor through the light from the light emitting element.

  In the optical sensor according to the present invention, the light-emitting element and the light-receiving element are installed on an inexpensive flat substrate provided with an electric wiring pattern, and the cap is installed so as to cover the light-emitting element and the light-receiving element. Structure.

  Since the cap is opaque, there is no need for a light shielding film forming step as in a conventional cover substrate. In addition, since the cap is disposed so as to cover the light emitting element and the light receiving element disposed on the insulating substrate, a step of forming a recess in the insulating substrate by etching is not necessary. Furthermore, since the insulating substrate does not have a concave portion, a step of preventing disconnection of the electric wiring to the light emitting element and the light receiving element is unnecessary. Therefore, the manufacturing of the optical sensor according to the present invention can omit the steps necessary for manufacturing the conventional optical sensor and can reduce the manufacturing cost.

  On the other hand, since the cap does not have a light shielding film, there is no peeling due to deterioration of the light shielding film, and there is no decrease in measurement accuracy. Further, in the cap, since light from the light emitting element does not pass through the cover substrate unlike a conventional cover substrate, light that does not pass through the subject received by the light receiving element can be reduced. Therefore, the optical sensor according to the present invention can reduce the noise of the signal from the light receiving element, and the measurement accuracy is improved.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  The light emitting element of the optical sensor according to the present invention is a surface-emitting type that emits outgoing light in a normal direction of the insulating substrate, and the light receiving element receives scattered light from the normal direction of the insulating substrate. It is a surface incident type, and the first opening of the cap is a first hole in the emission direction of the emitted light of the light emitting element, and the second opening of the cap is the first opening with respect to the light receiving element. The light receiving element is a second hole in a direction in which scattered light can be received.

  The present invention can provide an optical sensor that is equipped with a surface-emitting light-emitting element and a surface-incident light-receiving element, can be easily manufactured at low cost, and can perform highly accurate measurement.

  In the optical sensor according to the present invention, it is preferable that the cap has a rotationally symmetric shape with a perpendicular of the insulating substrate passing through an intermediate point between the center of the first hole and the center of the second hole as a two-fold axis. The rotationally symmetric shape with respect to the two-fold axis means a shape that does not change even if it is rotated 180 degrees around the axis. In the following description, “a rotationally symmetric shape with respect to the two-fold axis” is indicated as “a two-fold rotationally symmetric shape”.

  The mounting process of mounting the cap on the insulating substrate includes a front / back confirmation step for aligning the front and back of the cap and a direction confirmation step for aligning the direction of the cap. If the shape of the cap viewed from the insulating substrate side is not a rotationally symmetric shape twice, it is necessary to rotate the cap 180 degrees at the maximum in order to correctly align the cap and the insulating substrate in the direction confirmation step. . On the other hand, if the shape of the cap viewed from the insulating substrate side is a two-fold rotationally symmetric shape, the cap can be mounted on the insulating substrate at a maximum of 90 degrees.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  In the optical sensor according to the present invention, the cap may have a rotationally symmetric shape with a parallel line parallel to the insulating substrate passing through an intermediate point between the center of the first hole and the center of the second hole as a two-fold axis. preferable.

  If the shape of the cap viewed from a direction parallel to the surface of the insulating substrate is not a rotationally symmetric shape twice, it is necessary to rotate the cap by 180 degrees at the front and back confirmation step. On the other hand, if the shape of the cap viewed from a direction parallel to the surface of the insulating substrate is rotationally symmetrical twice, the cap can be mounted on the insulating substrate with a maximum rotation of 90 degrees.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  The light emitting element of the optical sensor according to the present invention is an end face light emitting type that emits outgoing light from an end face in a direction parallel to the surface of the insulating substrate, and the light receiving element is from a direction parallel to the surface of the insulating substrate. The first opening of the cap is in the emission direction of the emitted light of the light emitting element with respect to the light emitting element, and the second opening of the cap Is characterized in that the light receiving element is in a direction capable of receiving scattered light with respect to the light receiving element.

  The light emitting element of the optical sensor according to the present invention is a surface-emitting type that emits outgoing light in a normal direction of the insulating substrate, and the light receiving element emits scattered light from a direction parallel to the surface of the insulating substrate. The cap is of an end surface incident type that receives light at an end surface, and the cap further includes an optical path conversion element that converts a direction of emitted light of the light emitting element into a direction parallel to a surface of the insulating substrate, The one opening is in an optical path direction in which the light emitted from the light emitting element is converted by the optical path conversion element of the cap, and the second opening of the cap has the light receiving element scattered light with respect to the light receiving element. It is in the direction which can receive light.

  The light emitting element of the optical sensor according to the present invention is an end face light emitting type that emits outgoing light from an end face in a direction parallel to the surface of the insulating substrate, and the light receiving element is scattered from the normal direction of the insulating substrate. It is a surface incidence type that receives light, and the cap further includes an optical path conversion element that converts the direction of scattered light, which is a direction parallel to the surface of the insulating substrate, into the normal direction of the insulating substrate, The first opening of the cap is in an emission direction of emitted light of the light emitting element with respect to the light emitting element, and the second opening of the cap is with respect to the optical path conversion element of the cap. The optical path conversion element of the cap is in a direction in which scattered light can be irradiated, and the optical path conversion element of the cap converts the optical path of the scattered light that has passed through the second opening and causes the light receiving element to receive the light. .

  The present invention provides an optical sensor that emits outgoing light in a horizontal direction on the insulating substrate, receives scattered light from the horizontal direction on the insulating substrate, can be easily manufactured at low cost, and can perform highly accurate measurement. Can be provided. In addition, a surface light emitting element or a surface incident light receiving element can also be used by appropriately using an optical path conversion element.

  The cap of the optical sensor according to the present invention further includes a partition plate that partitions between the light emitting element and the light receiving element and prevents the light receiving element from directly receiving light emitted from the light emitting element. Also good.

  Since the partition plate partitions the light emitting element and the light receiving element in the cap, it is possible to prevent the light receiving element from receiving light from the light emitting element reflected in the cap. The light receiving element can output a signal in which noise due to light from the light emitting element reflected in the cap is reduced. In addition, since the partition plate is simply bonded to the insulating substrate side of the cap, the cap can be easily manufactured. Or the cap which has a partition plate from the beginning can also be manufactured. The step of bonding the partition plate can be omitted, and the cap can be easily manufactured.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  In the optical sensor according to the present invention, the insulating substrate further includes an electrical wiring on a surface on which the light emitting element and the light receiving element are mounted, the cap is formed of a conductive material, and the insulator substrate It may be in contact with the electrical wiring connected to the cathode of the light receiving element among the electrical wirings above, and may have the same potential as the cathode of the light receiving element.

  In the optical sensor according to the present invention, the insulating substrate further includes an electrical wiring on a surface on which the light emitting element and the light receiving element are mounted, the cap is formed of a conductive material, and the insulating substrate The electrical wiring on the body substrate may be in contact with the electrical wiring connected to the cathode of the light emitting element, and may have the same potential as the cathode of the light emitting element.

  The signal of the light receiving element is weak until amplified by an amplifier, and is easily affected by external electromagnetic noise. Since the conductive cap has the same potential as the light emitting element and / or the cathode of the light receiving element, it is possible to prevent external electromagnetic noise and improve the signal-to-noise ratio of the signal from the light receiving element.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  The optical sensor according to the present invention further includes an amplification circuit for amplifying a signal output from the light receiving element on the surface of the insulating substrate covered with the cap, and the cathode of the amplification circuit is the cathode of the light receiving element. The length of the wiring connected to the electric wiring to be connected and coupling the signal output from the light receiving element to the amplifier circuit may be 0.1 mm or more and 10 mm or less.

  The signal of the light receiving element is weak until amplified by an amplifier, and is easily affected by external electromagnetic noise. Therefore, the amplifier circuit is disposed adjacent to the light receiving element in the cap. The signal-to-noise ratio of the signal from the amplifier can be improved by shortening the distance from the light receiving element to the amplifier circuit that is greatly affected by external electromagnetic noise and amplifying the signal from the light receiving element in the cap. Since the amplifier circuit is only disposed on the insulating substrate in the same manner as the light emitting element and the light receiving element, the optical sensor according to the present invention can be easily manufactured.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  In the optical sensor according to the present invention, the cap has a protrusion on the insulator substrate side, and the insulator substrate has a hole or a hole into which the protrusion of the cap is inserted to position the cap. preferable.

  When the relative position between the cap and the insulating substrate changes, the relative position between the light emitting element and the first hole and the relative position between the light receiving element and the second hole change. Make a difference. Therefore, the positioning projections are provided in advance on the cap, and the positioning holes or holes are provided in advance on the insulator substrate. When the cap is mounted on the insulator substrate, the protrusions of the cap are inserted into the holes or the holes of the insulating substrate, so that the position between the two can be adjusted easily and with high accuracy. In addition, since the protrusion and the hole or the hole are provided at a predetermined location, the relative position between the cap and the insulating substrate is constant between the optical sensors, so that the measurement accuracy of the optical sensor is kept constant. Can do.

  Therefore, the present invention can provide an optical sensor that can be easily manufactured at low cost and can perform high-precision measurement.

  In order to achieve the object, a biological information measuring apparatus according to the present invention includes the optical sensor.

  Specifically, the present invention includes an integrated circuit including the optical sensor, a circuit that drives the light emitting element, and a digital signal processor that processes a signal from the optical sensor and calculates a value related to biological information. It is a biological information measuring device provided.

  Since the biological information measuring device according to the present invention uses the optical sensor according to the present invention, biological information can be measured with high accuracy. Furthermore, the biological information measuring device according to the present invention can be manufactured at low cost because it uses an optical sensor that is easy to manufacture.

  A sensor chip according to the present invention is a sensor chip comprising: an optical sensor having a first opening and a second opening on a side surface of a cap; and a strip-shaped circuit board on which the optical sensor is mounted at one end in a longitudinal direction. The optical sensor emits light emitted from the light emitting element in the direction from the other end to the one end of the circuit board.

  In addition, a sensor chip according to the present invention includes an optical sensor having a first opening and a second opening on a side surface of a cap, and a strip-shaped circuit board on which the optical sensor is mounted at one end in a longitudinal direction. The optical sensor emits light emitted from the light emitting element in a direction parallel to the surface of the circuit board and perpendicular to the longitudinal direction of the circuit board.

  If a strip-shaped circuit board is used as a probe, the optical sensor can be placed in the back or narrow part of the subject, and biological information of the part can be acquired.

  As described above, the present invention can provide an optical sensor and a biological information measuring apparatus that can be easily manufactured at low cost and can perform high-accuracy measurement.

It is the schematic of the optical sensor which concerns on one Embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the electrical wiring pattern on an insulating substrate. It is an example of the electrical wiring pattern on an insulating substrate. It is an example of the electrical wiring pattern on an insulating substrate. It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is a top view seen from the cap side, (b) is a figure of the cut surface in A-A 'of (a). It is the schematic of the sensor chip carrying the optical sensor which concerns on this invention. It is the schematic of the sensor chip carrying the optical sensor which concerns on this invention. It is the schematic of the sensor chip carrying the optical sensor which concerns on this invention. It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is the schematic of a cap back surface, (c) is an example of the position of the hole on an insulated substrate. (B) schematically shows a cap mounting step of mounting the cap on the insulating substrate. It is an example of the shape of a cap. (A) is the figure seen from the cap back surface, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the shape of a cap. (A) is the figure seen from the cap back surface, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the shape of a cap. (A) is the figure seen from the cap back surface, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the shape of a cap. (A) is the figure seen from the cap back surface, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the shape of a cap. (A) is the figure seen from the cap back surface, (b) is a figure of the cut surface in A-A 'of (a). It is an example of the shape of a cap. (A) is a top view, (c) is a rear view. (B) shows the cut surface cut by A-A ′ in (a). It is a block diagram which shows the structure of the blood flow meter as one Embodiment of the biometric information measuring apparatus which concerns on this invention. It is a measurement result of the blood flow meter concerning the present invention. The graph of (a) is the data of the temporal transition of the blood flow measured by the blood flow meter according to the present invention, and the graph of (b) is the data measured simultaneously by the commercial blood flow meter. It is a figure which shows the structure of the optical sensor of the conventional blood flow meter. (A) is a top view, FIG.22 (b) is sectional drawing in the A-A 'line of Fig.22 (a). It is a figure which shows the structure of the optical sensor of the conventional blood flow meter. (A) is sectional drawing in the B-B 'line of Fig.22 (a), (b) is sectional drawing in the C-C'line of Fig.22 (a). It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is the top view seen from the cap side, (b) is the side view seen from the 1st opening part and the 2nd opening part side. It is an example of the electrical wiring pattern on an insulating substrate. It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is the top view seen from the cap side, (b) is the side view seen from the 1st opening part and the 2nd opening part side, (c) is in DD 'line of (a). It is the figure which showed the cross section. It is the schematic of the optical sensor which concerns on other embodiment of this invention. (A) is the top view seen from the cap side, (b) is the side view seen from the 1st opening part and the 2nd opening part side, (c) is in DD 'line of (a). It is the figure which showed the cross section. It is the schematic of the sensor chip carrying the optical sensor which concerns on this invention. It is the schematic of the sensor chip carrying the optical sensor which concerns on this invention.

  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. In the present specification and drawings, the same reference numerals denote the same ones.

(Embodiment 1)
In the present embodiment, a light emitting element that generates outgoing light, a light receiving element that receives scattered light from the outside, an insulating substrate on which the light emitting element and the light receiving element are mounted, and an insulating substrate An opaque cap that covers the light emitting element and the light receiving element, wherein the cap has a first hole through which a part of light emitted from the light emitting element passes outside the optical sensor; and An optical sensor comprising a second hole through which a part of scattered light scattered from the outside of the optical sensor is received by the light receiving element.

  A schematic diagram of an optical sensor 501 according to this embodiment is shown in FIG. The optical sensor 501 includes an insulating substrate 11, a cap 13, a light emitting element 15, and a light receiving element 17. 1A is a top view of the optical sensor 501 viewed from the cap 13 side, and FIG. 1B is a cross-sectional view taken along line A-A ′ of FIG. The same applies to FIGS.

  Examples of the material of the insulating substrate 11 include insulators such as glass epoxy resin, fluororesin, and ceramic. On the surface of the insulating substrate 11, electrical wiring patterns from the electrical wiring 21a to the electrical wiring 21e shown in FIGS. 2 to 4 are formed. The reference numerals used in FIGS. 2 to 4 indicate the same parts as those described in FIG. The electric wiring 21a to the electric wiring 21e are metal capable of wire bonding, and examples thereof include a metal film such as a two-layer structure in which Au having a thickness of 0.3 μm is laminated on Ni having a thickness of 5 μm produced by plating. The insulating substrate 11 can be manufactured by a technique for manufacturing a known printed circuit board. The insulating substrate 11 may be a silicon substrate having a nitride film or an oxide film laminated on the surface. When the insulating substrate 11 is the silicon substrate, a metal electric wiring pattern can be formed on the surface by a known semiconductor manufacturing method. The electrical wiring pattern of the insulating substrate 11 in FIG. 1 is the electrical wiring pattern shown in FIG.

  The light emitting element 15 generates outgoing light. The light emitting element 15 is preferably a surface emitting semiconductor laser. As the semiconductor laser, a compound semiconductor that generates light having a wavelength of 0.6 μm to 1.6 μm can be used. In particular, light with a wavelength of 1.3 μm has 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 widely used in conventional commercial products. Flow waveform can be measured.

  The light receiving element 17 receives scattered light from the outside, and outputs a scattered light intensity signal corresponding to the light intensity of the scattered light. A photodiode is exemplified as the light receiving element 17. Since the scattered light is light obtained by scattering the laser light from the light emitting element 15 in the subject, the type of the photodiode is selected according to the type of the light emitting element 15.

  The cap 13 has a first hole 19a and a second hole 19b. The size of the first hole 19a is about 300 μm to 1000 μm, and the size of the second hole 19b is about 100 μm to 500 μm. In the present embodiment, both are described as 500 μm. The cap 13 is made of opaque plastic or metal. When the cap 13 is formed of plastic, the surface may be covered with a conductive film such as metal. If the 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 can be reduced. In this embodiment, the material of the cap 13 is described as aluminum.

  As shown in FIG. 2, the cathode (the side opposite to the light emitting surface) of the light emitting element 15 is connected to the electric wiring 21b via a solder film, and the light emitting element 15 is mounted on the insulating substrate 11. The anode (light emitting surface side) of the light emitting element 15 is connected to the electric wiring 21 a by a wire 23. The light receiving element 17 is also mounted on the insulating substrate 11 like the light emitting element 15. The anode of the light receiving element 17 is the electric wiring 21d, and the cathode is the electric wiring 21c.

  The cap 13 is mounted on the insulating substrate 11 so as to cover the light emitting element 15 and the light receiving element 17. The position of the cap 13 on the insulating substrate 11 allows light from the light emitting element 15 to pass through the first hole 19a and irradiate an external subject, and light from the outside passes through the second hole 19b to receive the light receiving element 17. Is a position where light can be received.

  Since the cap 13 has conductivity, the contact point between the cap 13 and the electric wiring 21a to the electric wiring 21d is covered with an insulating film 25 such as a resist so that the cap 13 and the electric wiring 21 are not electrically connected. When the cap 13 does not have conductivity, the insulating film 25 is not necessary.

  In the optical sensor 501, current is supplied from an external drive circuit (not shown) to the electrical wiring 21 to which the anode of the light emitting element 15 is connected, and current is supplied from the electrical wiring 21 to which the cathode of the light emitting element 15 is connected to the drive circuit. By going out, the light emitting element 15 emits light, and light can be irradiated to an external subject through the first hole 19a. In addition, in order to reduce the light reflected in the cap 13 among the light from the light emitting element 15, an antireflection film may be provided on the side of the cap 13 that covers the light emitting element 15 (inside the cap 13).

  On the other hand, the light receiving element 17 receives only light necessary for biological information measurement from the outside through the second hole 19b, converts it into an electrical signal, and outputs it to the electrical wiring 21c. Therefore, the optical sensor 501 outputs an electrical signal corresponding to the scattered light scattered by the external subject from the electrical wiring 21c.

  In the manufacture of the optical sensor 501, it is not necessary to etch the insulating substrate 11, and it is not necessary to form a light shielding film on the cap 13. Further, since there is no step on the insulating substrate 11, it is easy to form an electric wiring pattern. Therefore, the light-emitting element 15 and the light-receiving element 17 are mounted on an inexpensive flat insulating substrate 11 provided with an electric wiring pattern, and the cap 13 is only mounted so as to cover the light-emitting element 15 and the light-receiving element 17. The optical sensor 501 can be manufactured at low cost.

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

  FIG. 5 shows a schematic diagram of the optical sensor 505 according to the present embodiment. The difference between the optical sensor 501 and the optical sensor 501 of FIG. 1 is that the surface of the electrical wiring 21 c of the optical sensor 501 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. Since the surface of the electric wiring 21 c is not covered with the insulating film 25, the cap 13 and the electric wiring 21 c come into contact with each other, and the potential of the cap 13 becomes equal to the potential of the cathode of the light receiving element 17. Since the cap 13 has the same potential as the cathode of the light receiving element 17, it has an effect of preventing external electromagnetic noise. Since the signal output from the light receiving element 17 is very weak until amplified by an 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 21c and the 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 the electromagnetic noise of the cap 13.

  FIG. 6 shows a schematic diagram of the optical sensor 506 according to the present embodiment. The difference between the optical sensor 501 and the optical sensor 501 in FIG. 1 is that the electrical wiring pattern of the insulating substrate 11 is the electrical wiring pattern shown in FIG. 3 and the surface of the electrical wiring 21b of the optical sensor 501 is covered with the insulating film 25. That is not the point. In FIG. 6, the same reference numerals as those used in FIG. 1 denote the same components. As shown in FIG. 6, since the surface of the electric wiring 21 b is not covered with the insulating film 25, the cap 13 has the same potential as the cathode of the light emitting element 15, which is the same as the effect described in the optical sensor 505 of FIG. 5. The effect can be obtained.

  5 and 6 show the case where the surface of either the electric wiring 21b or the electric wiring 21c is not covered with the insulating film 25. However, both surfaces of the electric wiring 21b and the electric wiring 21c are covered with the insulating film 25. It does not have to be. Even in this case, the same effect as that described in the optical sensor 505 in FIG. 5 can be obtained.

  Further, the insulating substrate 11 may be mounted with the electric wiring pattern shown in FIG. The electric wiring pattern of FIG. 4 does not have the electric wiring 21b and the electric wiring 21c, but has an electric wiring 21e in which the cathodes of the light emitting element 15 and the light receiving element 17 are in common contact. When the cap 13 is mounted on the insulating substrate 11 on which the electric wiring pattern of FIG. 4 is mounted, the insulating film 25 is used to contact the electric wirings 21a, 21d and 21e with the cap 13 as described in the optical sensor 501 of FIG. It may be coated. The optical sensor of the insulating substrate 11 on which the electrical 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. The optical sensor of the insulating substrate 11 on which the electrical wiring pattern of FIG. 4 is mounted can obtain the same effect as the optical sensor 505 of FIG.

  The cap 13 may further include a partition plate 75 that partitions the light emitting element 15 and the light receiving element 17 and prevents the light receiving element 17 from directly receiving the light emitted from the light emitting element 15. FIG. 7 shows an optical sensor 507 including a cap 13 having a partition plate 75. 7, the same reference numerals as those used in FIG. 1 denote the same components.

  The partition plate 75 is the same material as the cap 13 and is opaque. The partition plate 75 is disposed inside the cap 13 so as to partition between the light emitting element 15 and the light receiving element 17 on the insulating substrate 11. A space surrounded by the cap 13 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 partition plate 75.

  Among the light received by the light receiving element 17, the interference component by the Doppler shift method is very weak, about several hundred pW. Therefore, if the light receiving element 17 receives light from the light emitting element 15 reflected in the space formed by the cap 13 and the insulating substrate 11, the intensity of the interference component is buried in the intensity of the light, and the light receiving element 17 outputs the light. The signal-to-noise ratio of the interference component signal deteriorates. Therefore, the optical sensor 507 can block the light from the light emitting element 15 by separating the small chamber of the light emitting element 15 and the small chamber of the light receiving element 17 by the partition plate 75 and improve the SN ratio of the signal output from the light receiving element 17. The biological information can be measured with high accuracy.

  An amplification circuit 85 that amplifies the signal output from the light receiving element 17 may be further provided on the surface of the insulating substrate 11 covered with the cap 13. The cathode of the amplifier circuit 85 is connected to the electrical wiring 21c to which the cathode of the light receiving element 17 is connected, and the length of the wire 83 that couples the signal output from the light receiving element 17 to the amplifier circuit 85 is 0.1 mm or more and 10 mm or less. . FIG. 8 shows an optical sensor 508 provided with an amplifier circuit 85. 8, the same reference numerals as those used in FIG. 1 denote the same parts, and a part of the cap 13 is omitted for explanation.

  The optical sensor 508 uses the electrical wiring pattern of FIG. 4, and the cathode of the light receiving element 17 and the ground of the amplifier circuit 85 share the electrical wiring 21c. The electrical wiring 81a and the electrical wiring 81b are power supply wirings for the amplifier circuit 85, and the electrical wiring 81c and the electrical wiring 81d are two terminals for outputting an amplified signal. Further, the output from the light receiving element 17 is input to the amplifier circuit 85 through the wire 83. Thus, the signal from the light receiving element 17 is amplified by the amplifier circuit 85 without passing through the electric wiring pattern on the insulating substrate 11, and is output from the electric wiring 81c and the electric wiring 81d.

  Since the light receiving element 17, the wire 83, and the amplifier circuit 85 are covered with the cap 13 that is conductive with the cathode of the light receiving element 17, the amplifier circuit 85 amplifies the signal from the light receiving element 17 before receiving electromagnetic noise from the outside. be able to.

  Furthermore, since the signals output from the amplifier circuit 85 to the electric wiring 81c and the electric wiring 81d through the wires 87a and 87b have already been amplified, the signal-to-noise ratio can be improved without being easily influenced by external noise. . Therefore, the optical sensor 508 can measure biological information with high accuracy.

  In addition, since a signal related to biological information from the optical sensor 508 is amplified, a signal with less noise can be obtained in an amplifier outside the optical sensor 508, and the amplifier can be simplified.

  FIG. 9 shows an optical sensor 509. 9, the same reference numerals as those used in FIG. 1 denote the same parts, and a part of the cap 13 is omitted for the sake of explanation. The insulating substrate 11 of the optical sensor 509 carries the electrical wiring pattern shown in FIG. The ground of the amplifier circuit 85 and the cathode of the light receiving element 17 are common electric wiring. The cathode of the light emitting element 15 and the cathode of the light receiving element 17 are connected to different electrical wirings, and the ground of the amplifier circuit 85 and the cathode of the light emitting element 15 can be separated. Since the amplification circuit 85 of the optical sensor 509 is not affected by noise caused by the power source of the light emitting element 15, the SN ratio can be improved. Therefore, the optical sensor 509 can measure biological information with high accuracy.

  FIG. 10 shows a sensor chip 610 on which an optical sensor and an external amplifier circuit are mounted. The sensor chip 610 includes a printed circuit board 91, an amplifier circuit 95, and an optical sensor 501.

  The sensor chip 610 is obtained by installing an optical sensor 501 on a printed circuit board 91 on which an amplifier circuit 95 is formed, using an insulating adhesive such as epoxy. The sensor chip 610 is not limited to the optical sensor 501, and the optical sensor 505 to the optical sensor 507 can be mounted. The amplifier circuit 95 requires a large amplification factor to amplify a weak signal from the optical sensor 501 and uses two operational amplifier ICs (an operational amplifier 95a and an operational amplifier 95b).

  The printed circuit board 91 includes electrode pads 93a to 93d. The electrode pad 93a to the electrode pad 93d are electrically connected by the wire 97 from the electric wiring 21a to the electric wiring 21d of the optical sensor, respectively. Further, an electrical wiring 99 is connected from the electrode pad 93d to which the anode of the light receiving element 17 is connected to the amplifier circuit 95 (the operational amplifier 95a).

  A signal output from the light receiving element 17 passes through the electric wiring 21d, the wire 97, the electrode pad 93d, and the electric wiring 99, is amplified by the operational amplifier 95a and then the operational amplifier 95b, and is output to the outside.

  In FIG. 10, the optical sensor 501 and the amplifier circuit 95 are mounted on one surface of the printed circuit board 91, but the optical sensor 501 is mounted on one surface of the printed circuit board 91 and the amplifier circuit 95 is mounted on the other surface. May be. By using both sides of the printed circuit board 91, the printed circuit board 91 can be downsized, and the sensor chip 610 can be downsized.

  FIG. 11 shows a sensor chip 611 in which the electrical wiring pattern shown in FIG. 2 is formed on the printed circuit board 91 and the light emitting element 15, the light receiving element 17 and the cap 13 are directly mounted on the printed wiring board 91. Similar to the description of the optical sensor 501 in FIG. 1, the light emitting element 15, the light receiving element 17, and the cap 13 are mounted on the printed wiring board 91. The sensor chip 611 operates in the same manner as the sensor chip 610 in FIG. Compared to the sensor chip 610 of FIG. 10, the sensor chip 611 includes a process of attaching the optical sensor 501 to the printed circuit board 91 and a process of wire bonding the electrical wiring 21a to the electrical wiring 21d and the electrode pad 93a to the electrode pad 93d. This eliminates the need for manufacturing costs. The electrical wiring pattern formed on the printed circuit board 91 is not limited to FIG. 2 and may be the electrical wiring pattern described in FIG.

  FIG. 12 shows a sensor chip 612 in which the optical sensor 509 described in FIG. 9 is mounted on the printed circuit board 91. Since the sensor chip 612 outputs the signal already amplified by the optical sensor 509, the amplifier circuit 95 can be the only operational amplifier 95b, and the printed circuit board 91 can be downsized. The sensor chip 612 may be equipped with the optical sensor 508 shown in FIG.

  As described with reference to FIGS. 10 to 12, the optical sensor 501 and any one of the optical sensors 505 to 509 are mounted on the printed circuit board 91, or an electrical wiring pattern is directly formed on the printed circuit board 91 to perform optical processing. By configuring any one of the sensor 501 and the optical sensors 505 to 509, it is possible to realize a sensor chip with high measurement accuracy that is easy to mount and has a reduced manufacturing cost.

(Embodiment 2)
In this embodiment, the cap has a projection on the insulator substrate side, and the insulator substrate has a hole or a hole for positioning the cap by inserting the projection of the cap. It is an optical sensor.

  FIG. 13 shows an optical sensor according to another embodiment. The reference numerals used in FIG. 13 indicate the same parts as the reference numerals described in FIG. A difference between the optical sensor of FIG. 13 and the optical sensor 501 of FIG. 1 is that the cap 13 has at least two protrusions 123 and the insulating substrate 11 has holes 121.

  The protrusion 123 is disposed at a location where the cap 13 contacts the insulating substrate 11. The protrusion 123 is formed of a material that does not deform. The cap 13 may be made of the same material. In FIG. 13A, the surface of the cap 13 that contacts the insulating substrate 11 (hereinafter, “the surface of the cap 13 that contacts the insulating substrate 11” is abbreviated as “the back surface of the cap 13”). Is a rectangle. The back surface shape of the cap 13 is not limited to a rectangle. The protrusion 123 may be disposed at any position as long as it is in contact with the insulating substrate 11 on the back surface of the cap 13. In the cap 13 of FIG. 13, the protrusions 123 are arranged at the corners of the rectangle. By arranging the protrusions 123 at the corners of the back surface of the cap 13 as shown in FIG.

  The hole 121 is a hole into which the protrusion 123 is inserted when the cap 13 is mounted on the insulating substrate 11, and has a size that allows the protrusion 123 to be inserted. The hole 121 is disposed on the insulating substrate 11 at a position where the protrusion 123 is positioned when the cap 13 is mounted. FIG. 13C shows an example of a place where the hole 121 is arranged. The hole 121 is abbreviated as “the surface of the insulating substrate 11 on the side of the light emitting element 15 and the light receiving element 17” (hereinafter referred to as “the surface of the insulating substrate 11”). ) Hole.

  FIG. 13B schematically shows a cap mounting process for mounting the cap 13 on the insulating substrate 11. By inserting the protrusion 123 into the hole 121, the cap 13 and the insulating substrate 11 can be easily aligned. Furthermore, since the positional accuracy of the protrusion 123 and the positional accuracy of the hole 121 are higher than the positioning accuracy of a human or a mounting machine in the cap mounting process, the position reproducibility between the cap 13 and the insulating substrate 11 is improved in the cap mounting process. Can do. Therefore, the positional reproducibility of the relative position between the first hole 19a and the light emitting element 15 of the cap 13 and the relative position between the second hole 19b and the light receiving element 17 is increased, and an optical sensor with high measurement accuracy can be manufactured.

  Therefore, the present invention can provide an optical sensor that can be manufactured at low cost and can measure biological information with high accuracy.

  In the optical sensor according to the present embodiment, the cap 13 is an imaginary line connecting the center of the first hole 19a and the center of the second hole 19b, that is, the center of the first hole 19a and the center of the second hole 19b. It is desirable to have a rotationally symmetric shape with the perpendicular of the insulating substrate 11 passing through the midpoint of the minute as the two-fold axis.

  FIG. 14 shows an example of the shape of the cap 13. 14A is a view as seen from the back surface of the cap 13, and FIG. 14B is a cross-sectional view taken along line A-A 'of FIG. 14A. The same applies to FIGS. 15 to 18. In the cap mounting process, a front / back confirmation step in which the back surface of the cap 13 faces the insulating substrate 11 and a direction confirmation step in which the cap 13 is rotated to determine a predetermined direction are necessary. Therefore, the amount of rotation of the cap 13 in the direction confirmation step can be reduced by making the shape viewed from the back surface of the cap 13 highly symmetrical. Furthermore, when the cap 13 has the protrusion 123, the protrusion 123 is also arranged at a position that is twice rotationally symmetric. Since the first hole 19a and the second hole 19b have the same size and are arranged at positions that are rotationally symmetrical with each other twice, the holes for the optical element 15 and the holes for the light receiving element 17 are interchanged when rotated 180 degrees. It will be.

  Therefore, by making the back surface shape of the cap 13 rotationally symmetrical twice, the direction of the cap 13 can be aligned only by rotating at most 90 degrees in the direction confirmation step, and the manufacturing cost of the optical sensor is reduced. be able to.

  FIGS. 15 to 18 show examples of the structure of the cap 13 whose shape viewed from the back surface of the cap 13 is a rotationally symmetric shape twice. FIG. 15 shows a cap 13 having a partition plate 75. FIG. 15A is a view as seen from the back surface of the cap 13, and FIG. 15B shows a cross-sectional view taken along A-A ′ in FIG. The same applies to FIGS. 16 to 18. The cap 13 of FIG. 15 has protrusions 123 at the four corners, so that a rotation error with respect to the insulating substrate 11 hardly occurs. Therefore, the amount of error in the relative position between the light emitting element 15 and the first hole 19a and the relative position between the light receiving element 17 and the second hole 19b is small, and the measurement accuracy of the optical sensor is improved. FIG. 16 is a view in the case where the protrusions 123 are arranged at two diagonal positions of the back surface shape of the cap 13. FIG. 17 is a diagram in the case where the protrusions 123 are arranged at both ends of the partition plate 75. When the cap 13 shown in FIG. 17 is mounted on the insulating substrate 11, the position of the partition plate 75 is exactly between the light emitting element 15 and the light receiving element 17. Therefore, the position of the partition plate 75 can be determined more accurately than the cap 13 shown in FIG. Further, since the position variation of the partition plate 75 is small, the optical sensor using the cap 13 shown in FIG. 17 brings the light emitting element 15 and the light receiving element 17 closer to each other than the optical sensor using the cap 13 shown in FIG. Can be installed. 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 using the cap 13 shown in FIG. Blood flow can be observed. FIG. 18 is a diagram in the case where the protrusions 123 are arranged at all the positions described with reference to FIGS. 15 and 17. Therefore, the cap 13 shown in FIG. 18 has both the effects described with reference to the cap 13 in FIG. 15 and the effects described with reference to the cap 13 in FIG.

  The optical sensor according to this embodiment may include a cap 193. The cap 193 is an insulating substrate 11 passing through an intermediate point between the center of the first hole 19a and the center of the second hole 19b, that is, the midpoint of an imaginary line segment connecting the center of the first hole 19a and the center of the second hole 19b. Is a rotationally symmetric shape with a parallel line parallel to the two-axis.

  FIG. 19 shows an example of the shape of the cap 193. FIG. 19A is a top view, and FIG. 19C is a rear view. FIG. 19B shows a cut surface cut along A-A ′ of FIG. The cap 193 is rotationally symmetrical twice with respect to the center position (the midpoint of the imaginary line segment), and is symmetrical with respect to the surface on which the first hole 19a and the second hole 19b exist, and has a structure with no front and back. It has become.

In the case of the shape of the cap 13 shown in FIGS. 14 to 18, the direction confirmation step can be omitted in the mounting process, but the front and back confirmation step is necessary. By using a structure in which the front and back sides are not distinguished like the cap 193 in FIG. 19, the front and back confirmation step can be omitted, and the manufacturing cost of the optical sensor can be reduced. The cap 193 may have a protrusion 123. Since the cap 193 has the protrusion 123, the alignment accuracy between the cap 193 and the insulating substrate 11 is improved as described with reference to FIGS. Although the cap 193 has the partition plate 75, the same effect can be obtained without the partition plate 75.

(Embodiment 3)
The present embodiment is a biological information measuring device including an integrated circuit including an optical sensor, a circuit that drives a light emitting element, and a digital signal processor that processes a signal from the optical sensor and calculates a value related to biological information. is there.

  FIG. 20 is a diagram showing a configuration of a blood flow meter 801 as an embodiment of the biological information measuring device according to the present invention. As shown in the figure, the blood flow meter of the present embodiment includes an optical sensor 201, a preamplifier 202, a driving / calculating device 203, and an output unit 204 that displays the obtained blood flow. In the following description, reference numerals used in FIGS. 1 to 19 are also used.

  The optical sensor 201 applies light to an external subject and receives scattered light scattered in the subject. The optical sensor 201 may be integrated on a semiconductor substrate, or the optical sensor described with reference to FIGS. 1 and 5 to 9 may be used.

  The preamplifier 202 amplifies and outputs the output from the optical sensor 201. As described in the sensor chip of FIGS. 10 to 12, the optical sensor 201 can be mounted on the substrate of the preamplifier 202. The sensor chip 620 integrated with the optical sensor 201 and the preamplifier 202 makes it possible to configure the sensor chip 620 so that it can be easily attached to a human body or the like. The preamplifier 202 is connected to the signal adjustment circuit 210 and receives the signal from the light receiving element 17 amplified by the amplification circuit 95 as described with reference to FIGS.

  The drive / arithmetic unit 203 includes an A / D converter 205, a light emitting element drive circuit 206, a digital signal processor (DSP) 207, a power supply unit 208, an interface 209, a signal adjustment circuit 210, and a display unit 211, and is a small liquid crystal display. Or the like. The entire drive / arithmetic unit 203 can be configured as an LSI. The drive / arithmetic unit 203 drives the light emitting element (LD) and determines the blood flow by analyzing the scattered light.

  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 and 5 to 9 irradiates and extinguishes light according to instructions from the light emitting element driving circuit 206.

  The A / D converter 205 samples the input analog signal at a predetermined frequency, quantizes it, and outputs it. It can be exemplified that the sampling frequency when measuring the blood flow or the like of the subject is 200 kHz.

  The DSP 207 is an electric circuit that processes an input digital signal according to a predetermined rule. Since the DSP 207 can process a large amount of digital signal data at high speed, the processing result of the input digital signal can be output in real time. The DSP 207 performs calculations 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 standard so that the drive / arithmetic unit 203 and an external peripheral device can communicate with each other. For example, the interface 209 can exemplify converting 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 DSP 207, the interface 209, the signal adjustment circuit 210, and the display unit 211 through electric lines (not shown).

  The output unit 204 displays data output from the interface 209. A small liquid crystal display can be exemplified.

  The blood flow meter 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 sensor chip irradiates the subject with light and receives scattered light from the subject as follows. The light emitting element 15 is injected with current from the light emitting element driving circuit 206 and emits irradiation light. Irradiation light from the light emitting element 15 is narrowed to a diameter necessary for blood flow measurement through the first hole 19a of the cap 13, and is irradiated to the subject. The light emitted from the first hole 19 a is scattered in the subject, and the scattered light reaches the optical sensor 201. The scattered light becomes only light necessary for measurement in the second hole 19 b of the cap 13 and is received by the light receiving element 17.

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

  The DSP 17 performs signal processing of the digital 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, and the intensity of the scattered light S corresponds to the moving blood volume. A flow rate is required. Furthermore, the scattered signal waveform also has a modulation component due to the pulse, and the pulse can be detected. The DSP 207 outputs subject information as a result of the frequency analysis as a subject information signal.

  The display unit 211 displays the subject information signal from the DSP 207. Further, the interface 209 converts the subject information signal into a signal of the RS-232C standard and outputs it to the display unit 204. As described above, the blood flow meter 801 measures biological information such as blood flow of the subject.

  The measurement result of the blood flow meter according to the present invention will be described with reference to FIG. The graph of FIG. 21A is data of the temporal transition of the blood flow measured by the blood flow meter 801, and the graph of FIG. 21B is a commercially available standard blood flow meter (commercial blood flow meter). It is the data measured simultaneously by. The measurement method of a commercially available blood flow meter is the same as the measurement method of the blood flow meter 801 (Doppler shift method).

  Each blood flow meter shows the blood flow rate when the device is applied to a finger, the blood is blocked by tightening the wrist strongly, gradually opened, and finally completely opened. In the measurement result of the blood flow meter 801, the pulse wave shape is averaged due to the difference in the response characteristics of the amplification circuit as compared with the measurement result of the commercial blood flow meter, but the increase / decrease tendency of the blood flow rate itself is the same.

  The commercially available 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. Furthermore, the commercially available blood flow meter receives scattered light scattered by the subject with another optical fiber and couples it to the light receiving element. Since the optical fiber changes its light propagation mode due to changes in bending, vibration during measurement, and the like, it is necessary to limit the operation of the subject when measuring biological information with a commercially available blood flow meter. Since the blood flow meter 801 does not use an optical fiber, accurate biological information can be measured without restricting the operation of the subject.

  Furthermore, since the blood flow meter 801 uses the optical sensor described with reference to FIGS. 1 and 5 to 9, biological information can be measured with high accuracy, and the manufacturing cost can be reduced.

  In the first to third embodiments, the optical sensor, the sensor chip, and the biological information measuring apparatus using the surface emitting semiconductor laser as the light emitting element and using the surface incident type photodiode as the light receiving element have been described. The light emitting element may be an end face light emitting type, and the light receiving element may be an end face incident type. An embodiment using an edge-emitting light emitting element and an edge-incident light receiving element will be described below.

(Embodiment 4)
The light emitting element of the optical sensor of the present embodiment is an end surface light emitting type that emits outgoing light from the end face in a direction parallel to the surface of the insulating substrate, and the light receiving element is from a direction horizontal to the surface of the insulating substrate. The first opening of the cap is in the emission direction of the emitted light of the light emitting element with respect to the light emitting element, and the second opening of the cap Is characterized in that the light receiving element is in a direction capable of receiving scattered light with respect to the light receiving element.

  FIG. 24 is a schematic diagram of an optical sensor 524 that uses an edge-emitting light-emitting element and an edge-incident light-receiving element. 24A is a top view of the optical sensor 524 viewed from the cap 13 side, and FIG. 24B is a side view of the optical sensor 524 viewed from the opening side. The same applies to FIGS. 26 and 27.

  The light emitting element 245 is an edge emitting semiconductor laser. The light emitting element 245 is mounted on the insulating substrate 11 so that the emitted light L can be emitted in a direction horizontal to the surface of the insulating substrate 11. The light receiving element 247 is an end face incident type photodiode. The light receiving element 247 is mounted so as to receive the scattered light S from a direction horizontal to the surface of the insulating substrate 11. Here, the scattered light S is light that is emitted light L scattered by an external subject. Therefore, the light receiving element 247 is mounted in a direction that can receive the scattered light S with high sensitivity. In FIG. 24, the optical axes of the outgoing light L and the scattered light S are shown as parallel.

  The cap 13 has a first opening 249a and a second opening 249b on the side surface. The light emitting element 245 emits the emitted light L through the first opening 249a. The light receiving element 247 receives the scattered light S through the second opening 249b. The first opening 249a and the second opening 249b are arranged in parallel.

  FIG. 25 shows electrical wiring formed on the insulating substrate 11 of the optical sensor 524. Connections between the respective electric wirings and the light emitting element 245 and the light receiving element 247 are the same as in the description of FIG.

  The optical sensor 524 can be manufactured at a low cost similarly to the description of the optical sensor 501 in FIG. 1, and can measure biological information of a subject with high accuracy.

(Embodiment 5)
The light emitting element of the optical sensor of this embodiment is a surface-emitting type that emits outgoing light in the normal direction of the insulating substrate, and the light receiving element emits scattered light from a direction parallel to the surface of the insulating substrate. The cap is of an end surface incident type that receives light at an end surface, and the cap further includes an optical path conversion element that converts a direction of emitted light of the light emitting element into a direction parallel to a surface of the insulating substrate, The one opening is in an optical path direction in which the light emitted from the light emitting element is converted by the optical path conversion element of the cap, and the second opening of the cap has the light receiving element scattered light with respect to the light receiving element. It is in the direction which can receive light.

  FIG. 26 is a schematic diagram of an optical sensor 526 that uses a surface-emitting light-emitting element and an end-face incident light-receiving element. The difference between the optical sensor 526 and the optical sensor 524 of FIG. 24 is that the light-emitting element uses a surface-emitting type instead of an edge-emitting type. In addition, since the light emitting element 15 emits the emitted light L upward, the cap 13 includes an optical path conversion element 262 that converts the optical path toward the first opening 249a. The optical path conversion element 262 is a mirror, for example. FIG. 26C is a cross-sectional view taken along D-D ′ in FIG.

  The optical path conversion element 262 converts the emitted light L emitted upward from the light emitting element 15 into the first opening 249a. Therefore, the optical sensor 526 can obtain the same effect as the optical sensor 524 described with reference to FIG.

(Embodiment 6)
The light emitting element of the optical sensor of the present embodiment is an end surface light emitting type that emits outgoing light from the end face in a direction parallel to the surface of the insulating substrate, and the light receiving element is scattered from the normal direction of the insulating substrate. It is a surface incidence type that receives light, and the cap further includes an optical path conversion element that converts the direction of scattered light, which is a direction parallel to the surface of the insulating substrate, into the normal direction of the insulating substrate The first opening of the cap is in an emission direction of emitted light of the light emitting element with respect to the light emitting element, and the second opening of the cap is with respect to the optical path conversion element of the cap. The optical path conversion element of the cap is in a direction in which scattered light can be irradiated, and the optical path conversion element of the cap converts the optical path of the scattered light that has passed through the second opening and causes the light receiving element to receive the light. .

  FIG. 27 is a schematic diagram of an optical sensor 527 that uses an edge-emitting light-emitting element and a surface-incident light-receiving element. The difference between the optical sensor 527 and the optical sensor 524 of FIG. 24 is that the light receiving element uses a surface incident type instead of an end face incident type. Further, since the light receiving element 17 emits scattered light S from above, the cap 13 has an optical path conversion element 272 that converts the optical path of the scattered light S incident from the second opening 249b toward the light receiving surface of the light receiving element 17. Have. The optical path conversion element 272 is, for example, a mirror. FIG. 27C is a cross-sectional view taken along D-D ′ in FIG.

  The optical path conversion element 272 converts the optical axis of the scattered light S so that the light receiving element 17 can receive the scattered light S incident from the second opening 249b horizontally on the surface of the insulating substrate 11. Therefore, the optical sensor 527 can obtain the same effect as the optical sensor 524 described with reference to FIG.

(Embodiment 7)
The optical sensor described in FIG. 24, FIG. 26 or FIG. 27 can be mounted on a circuit board on which an amplifier is mounted to form a sensor chip.

  The sensor chip of the present embodiment is a sensor chip comprising the optical sensor described in FIG. 24, FIG. 26 or FIG. 27 and a strip-shaped circuit board on which the optical sensor is mounted at one end in the longitudinal direction. The optical sensor emits light emitted from the light emitting element in the direction from the other end to the one end of the circuit board.

  FIG. 28 shows the sensor chip 628. The sensor chip 628 mounts the optical sensor 524 of FIG. 24 on one end of a strip-shaped circuit board 491. The optical sensor 524 is mounted on the circuit board 491 so that the first opening 249a and the second opening 249b face the opposite side of the other end side of the circuit board 491. The sensor chip 628 also includes a power supply circuit and an amplifier (not shown). The sensor chip 628 can be substituted for the sensor chip 620 of the blood flow meter 801 of FIG.

  When measuring biological information, one end of the sensor chip 628 is brought close to the subject 900. By emitting the emitted light L from the light emitting element 245 described in FIG. 24, the optical sensor 524 of the sensor chip 628 emits the emitted light L of the light emitting element 245 from the other end of the circuit board 491 to one end. Irradiate the subject 900 at the tip of one end of the substrate 491. Further, the optical sensor 524 of the sensor chip 628 receives the scattered light S scattered by the emitted light L inside the subject 900 by the light receiving element 247 described with reference to FIG. 24 through the second opening 249b described with reference to FIG. The blood flow meter 801 can measure blood flow as biological information as described with reference to FIG. 20 even when the sensor chip 628 is used.

  Furthermore, since the sensor chip 628 mounts the optical sensor 524 at the tip of the strip-shaped circuit board 491, biological information can be measured even when the subject 900 is in the back or in a narrow place. For example, the sensor chip 628 can measure the blood flow of the subject 900 in the back of the nose, in the oral cavity, or in the intestine.

  Further, an optical sensor 524 may be mounted on the circuit board 491 as in a sensor chip 629 in FIG. Specifically, the sensor chip 629 is a sensor chip including an optical sensor 524 and a strip-shaped circuit board 491 on which the optical sensor 524 is mounted at one end in the longitudinal direction. The optical sensor 524 is illustrated in FIG. The emitted light L of the light emitting element 245 described above is emitted in a direction parallel to the surface of the circuit board 491 and perpendicular to the longitudinal direction of the circuit board 491. The sensor chip 629 has the same configuration as that of the sensor chip 628 of FIG. 28, and the same effect can be obtained.

  In the sensor chip 628 and the sensor chip 629, the optical sensor mounted on the circuit board 491 may be the optical sensor 526 in FIG. 26 or the optical sensor 527 in FIG. 27 in addition to the optical sensor 524 in FIG.

  The biological information measuring apparatus and optical sensor 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 the tube can transmit light from the light emitting element, such as a fluororesin tube and a silicon tube, the biological information measuring device and the optical sensor of the present invention are manufactured by a semiconductor It can be used for flowmeters of equipment and cooling devices.

501, 505-509, 524, 526, 527 Optical sensor 610-612, 620, 628, 629 Sensor chip 801 Blood flow meter 11 Insulating substrate 13 Cap 15, 245 Light emitting element 17, 247 Light receiving element 19a First hole 249a First Opening 249b Second opening 19b Second hole 21a-e Electrical wiring 23 Wire 25 Insulating film 75 Partition plate 81a-d Electrical wiring 83 Wire 87a, b Wire 88a, b Wire 85 Amplifier circuit 91 Printed circuit board 93a-d Electrode Pad 95 Amplifier circuit 95a, b Operational amplifier 97 Wire 99 Electrical wiring 121 Hole 123 Protrusion 201 Optical sensor 202 Preamplifier 203 Drive / arithmetic unit 204 Output unit 205 A / D converter 206 Light emitting element drive circuit 207 DSP
208 Power supply unit 209 Interface 210 Signal adjustment circuit 211 Display unit 262, 272 Optical path conversion element 321 Silicon substrate 322, 324 Electrode 361 Laser diode 325 Photo diode 326 Cover substrate 362 Refractive lens 327 331 Light shielding film 329 Wire 491 Circuit substrate L Emitted light S scattered light

Claims (3)

A light emitting element for generating outgoing light;
A light receiving element for receiving scattered light from the outside;
An insulating substrate on which the light emitting element and the light receiving element are mounted;
An opaque cap that covers the light emitting element and the light receiving element on the insulating substrate;
An optical sensor comprising:
The cap passes through a first opening that allows a part of the light emitted from the light emitting element to pass outside the optical sensor and a part of the scattered light that is scattered from outside the optical sensor. A second opening for allowing the light receiving element to receive light,
The light-emitting element is a surface-emitting type that emits outgoing light in a normal direction of the insulating substrate,
The light receiving element is an end face incident type that receives scattered light from a direction parallel to the surface of the insulating substrate at an end face;
The cap further includes an optical path conversion element that converts the direction of the emitted light of the light emitting element into a direction horizontal to the surface of the insulating substrate;
The first opening of the cap is in an optical path direction in which emitted light of the light emitting element is converted by the optical path conversion element of the cap,
The optical sensor, wherein the second opening of the cap is in a direction in which the light receiving element can receive scattered light with respect to the light receiving element. The optical sensor of claim 1;
A strip-shaped circuit board on which the optical sensor is mounted at one end in the longitudinal direction;
A sensor chip comprising:
The optical sensor emits light emitted from the light emitting element in the direction from the other end to the one end of the circuit board. The optical sensor of claim 1;
A strip-shaped circuit board on which the optical sensor is mounted at one end in the longitudinal direction;
A sensor chip comprising:
The optical sensor emits light emitted from the light emitting element in a direction parallel to the surface of the circuit board and perpendicular to the longitudinal direction of the circuit board.

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