JP6502718B2 - Biometric information sensor - Google Patents

Description

  The present invention relates to a biometric information sensor, and more particularly to a wearable biometric information sensor.

  2. Description of the Related Art Wearable living body information sensors are conventionally known. For example, a wearable biological information sensor is disclosed in Japanese Patent Application Laid-Open No. 2012-143316 (Patent Document 1). The biological information sensor includes first and second light sensors and an arithmetic circuit. The first light sensor receives a first light receiving portion that emits light of a first light emission intensity to a living body, and light emitted from the first light emitting portion is reflected by the inside of the living body to receive a first light reception signal. And a first light receiving unit to generate. The second light sensor includes a second light emitting unit that emits light of a second light emission intensity that is weaker than the first light emission intensity to the living body, and light emitted from the second light emitting unit that is reflected in the living body And a second light receiving unit that receives and generates a second light reception signal. The arithmetic circuit subtracts the second light reception signal from the first light reception signal to acquire pulse wave data.

JP, 2012-143316, A

  When a biological information sensor is attached to the body and biological information such as blood pulse saturation or blood oxygen saturation concentration is measured while exercising outdoors, etc., sunlight containing infrared light is incident on the biological information sensor Measurement errors can occur.

  Therefore, the main object of the present invention is to provide a biological information sensor capable of enhancing the measurement accuracy.

  A biological information sensor according to the present invention includes a light receiving unit, and generates information on a living body based on a signal from the light receiving unit. The light receiving unit includes a first light sensor that converts the first light into a first signal. The first light sensor has a first photoelectric conversion element and a first color filter. The first photoelectric conversion element converts the first light into a first signal. The first color filter is formed on the light path to the first photoelectric conversion element, and transmits the first light. The biological information sensor further includes an infrared light removal layer formed on the light path to the first photoelectric conversion element.

  The color filter is a color resist film containing pigments such as red, green and blue. For the color resist, a pigment dispersed resist in which a pigment is finely dispersed as a coloring material in addition to the resist component is used.

  With such a configuration, light from which infrared light has been removed by the infrared light removal layer is incident on the first light sensor. Since the first color filter transmits the first light contained in the light transmitted through the infrared light removal layer, most of the light received by the first photoelectric conversion element is the first light. As a result, the biological information sensor can generate information on the living body with little influence of infrared light. That is, according to the biological information sensor of the present invention, the measurement accuracy can be increased.

  Preferably, the biological information sensor further includes an arithmetic control unit. The arithmetic control unit generates information on the living body based on the signal from the light receiving unit. The light receiving unit further includes a second light sensor. The second light sensor converts the second light into a second signal. The second light sensor has a second photoelectric conversion element and a second color filter. The second photoelectric conversion element converts the second light into a second signal. The second color filter is formed on the light path to the second photoelectric conversion element and transmits the second light. The infrared light removal layer is also formed on the light path to the second photoelectric conversion element. The arithmetic control unit receives the first signal and the second signal from the light receiving unit, and generates information on the living body based on the first signal and the second signal.

  Preferably, the light receiving unit further includes a first substrate on which the first light sensor and the second light sensor are formed. The infrared light removal layer is formed on the surface of the first substrate.

The level of the signal may include, for example, the voltage value or current value of the electrical signal.
Preferably, the infrared light removal layer includes an infrared cut filter. The infrared cut filter covers the first color filter and the second color filter.

  The infrared cut filter is a multilayer film in which a plurality of thin films having different refractive indexes are stacked and light having a shorter wavelength than infrared light is transmitted. As a plurality of thin films having different refractive indexes, one obtained by periodically laminating a TiO 2 film and an SiO 2 film by a sputtering method can be mentioned.

  Preferably, the infrared light removal layer contains an infrared cut resin. The infrared cut resin covers the first substrate.

  The infrared cut resin is a resin containing a material that absorbs infrared light (for example, light having a wavelength of 750 nm or more).

  Preferably, the infrared light removal layer includes an infrared cut filter and an infrared cut resin. The infrared cut filter covers the first color filter and the second color filter. The infrared cut resin is laminated on the infrared cut filter to cover the first substrate.

  Preferably, the biological information sensor further includes a light emitting unit, a second substrate, a first light shielding wall, and a second light shielding wall. The light emitting unit emits light including the first light and the second light. The second substrate is provided with a light emitting unit, a light receiving unit, and an arithmetic control unit. The first light shielding wall is formed along the outer periphery of the second substrate so as to surround the light emitting unit and the light receiving unit. The second light shielding wall divides the space formed by the second substrate and the first light shielding wall into a space on the light emitting portion side and a space on the light receiving portion side. When the biological information sensor is attached to the living body, light reflected by the inside of the living body among the light emitted from the light emitting unit is incident on the light receiving unit.

Preferably, the light emitting unit is a light emitting diode that emits white light.
Preferably, the first light is green light. The second light is red light.

  Preferably, the operation control unit generates information on the living body based on the difference between the level of the first signal and the level of the second signal.

Preferably, the information on the living body is a heart rate.
The arithmetic control unit generates information on the living body based on a ratio of the level of the first signal to the level of the second signal.

  Preferably, the information on the living body is blood oxygen saturation level.

  According to the biological information sensor according to the present invention, it is possible to increase the measurement accuracy by removing the infrared light contained in the light incident on the biological information sensor by the infrared light removal layer.

It is a sectional view showing the composition of the living body information sensor according to a 1st embodiment. It is sectional drawing which shows the structure of the light-receiving part with which the biometric information sensor according to 1st Embodiment is equipped. It is a figure which shows the spectral characteristic of an infrared cut filter, G filter, R filter, and a photodiode. It is a functional block diagram of the biometric information sensor according to 1st Embodiment. It is a time chart which illustrates operation of a living body information sensor according to a 1st embodiment. It is sectional drawing which shows the structure of the light-receiving part with which the biometric information sensor according to 2nd Embodiment is provided. It is sectional drawing which shows the structure of the light-receiving part with which the biometric information sensor according to 3rd Embodiment is provided. It is a functional block diagram of the biometric information sensor according to 4th Embodiment. It is a figure which shows the relationship between the wavelength of light, the molar absorption coefficient of hemoglobin, the spectral sensitivity of G filter, and the spectral sensitivity of R filter. It is a functional block diagram of the calculating part with which the biometric information sensor according to 4th Embodiment is provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference characters and description thereof will not be repeated.

First Embodiment
FIG. 1 is a cross-sectional view showing a configuration of a biological information sensor 1 according to the first embodiment. Below, the case where a heart rate is measured as information on a living body by the biological information sensor 1 will be described.

  Referring to FIG. 1, the biological information sensor includes a light emitting unit 10 which is a white LED, a light receiving unit 11 which is an integrated circuit, light shielding walls 13 and 14, lenses 15 and 16, a transparent plate 17 and a substrate 18. And the arithmetic control unit 200.

  A light emitting unit 10, a light receiving unit 11, and an arithmetic control unit 200 are formed on the surface of the substrate 18. The light receiving unit 11 includes a silicon substrate 12 and a G sensor 111 and an R sensor 112 formed on the silicon substrate 12. The arithmetic control unit 200 may be formed on the silicon substrate 12.

  At the edge of the surface of the substrate 18, a light shielding wall 14 is formed to surround the light emitting unit 10 and the light receiving unit 11 to prevent external light from entering the light receiving unit 11. At the center of the surface of the substrate 18, a light shielding wall 13 is formed to prevent white light emitted from the light emitting unit 10 from being directly incident on the light receiving unit 11. That is, the space formed by the light shielding wall 14 is divided by the light shielding wall 13 into a space on the light emitting portion 10 side and a space on the light receiving portion 11 side.

  A lens 15 is provided in the emitting direction of the light emitting unit 10, and a lens 16 is provided in the light receiving direction of the light receiving unit 11. The opening at the lower end of the light shielding walls 13 and 14 is closed by the transparent plate 17. When the heart rate is detected, the surface of the transparent plate 17 is in close contact with the surface of the human body 50.

  The white light emitted from the light emitting unit 10 is irradiated to the human body 50 through the lens 15 and the transparent plate 17. Of the white light, light α reflected in the body is incident on the light receiving unit 11 through the transparent plate 17 and the lens 15. The green light intensity of the light α is converted into a signal by the G sensor 111. The intensity of red light in the light α is converted into a signal by the R sensor 112. The arithmetic control unit 200 generates a signal indicating a heart rate based on the signal from the G sensor 111 and the signal from the R sensor 112.

  When the user wears the biological information sensor 1 on the human body 50 and measures the heart rate outdoors or the like, there is a case where light β transmitted or reflected in the human body 50 in sunlight is incident on the light receiving unit 11. The light β derived from sunlight contains infrared light. The G sensor 111 and the R sensor 112 show the strongest sensitivities to green light and red light, respectively, but the sensitivity to infrared light is also not zero. Therefore, the light β may be noise when the biological information sensor 1 measures the heart rate, and may cause an error in the measured heart rate.

  Therefore, in the first embodiment, the infrared light is removed by the infrared light removal layer including the infrared cut filter.

  FIG. 2 is a cross-sectional view showing the configuration of the light receiving unit 11 provided in the biological information sensor 1 according to the first embodiment. Referring to FIG. 2, light receiving unit 11 includes a silicon substrate 12, a G (green light) sensor 111, an R (red light) sensor 112, and an infrared cut filter 101.

  The G sensor 111 includes a photodiode 111A and a G filter 111B, and the R sensor 112 includes a photodiode 112A and an R filter 112B. The G filter 111B transmits green light. The photodiode 111A converts the green light transmitted through the G filter 111B into a signal S1. The R filter 112B transmits red light. The photodiode 112A converts the red light transmitted through the R filter 112B into a signal S2.

  The silicon substrate 12 is divided into an upper layer 12A and a lower layer 12B. A G filter 111B and an R filter 112B are formed on the surface of the upper layer 12A. At the boundary between the upper layer 12A and the lower layer 12B, the photodiodes 111A and 112A are provided on the lower layer 12B side. The G filter 111B and the R filter 112B face the photodiodes 111A and 112A, respectively. Therefore, light incident on the photodiode 111A passes through the G filter 111B, and light incident on the photodiode 112A passes through the R filter 112B. That is, the G filter 111B is formed on the light path to the photodiode 111A, and the R filter 112B is formed on the light path to the photodiode 112A.

  The infrared cut filter 101 is formed on the surface of the upper layer 12A and covers the G filter 111B and the R filter 112B. Therefore, light incident on the photodiode 111A and the photodiode 112A is transmitted through the infrared cut filter. That is, the infrared cut filter 101 is formed on the light path to the photodiode 111A, and is also formed on the light path to the photodiode 112A.

  With such a configuration, most of the light input to the photodiode 111A is green light, and most of the light input to the photodiode 112A is red light. Such a result is due to the difference in spectral characteristics of the infrared cut filter 101, the G filter 111B, and the R filter 112B. Therefore, in the following, focusing on the respective spectral characteristics, it will be described that most of the light input to the photodiode 111A and the photodiode 112A is green light and red light, respectively.

  FIG. 3 is a diagram showing spectral characteristics of the infrared cut filter 101, the G filter 111B, the R filter 112B, and the photodiode 111A (112A). In FIG. 3, Cir represents the spectral characteristics of the infrared cut filter 101, Cg represents the spectral characteristics of the G filter 111B, Cr represents the spectral characteristics of the R filter 112B, and C0 represents the spectral characteristics of the photodiode 111A (112A). Indicates

  When light enters the light receiving unit 11, first, the light passes through the infrared cut filter 101. Referring to FIG. 3, since the sensitivity of the near infrared region of the infrared cut filter 101 is substantially zero, infrared light contained in the light can not be transmitted through the infrared cut filter 101. The light transmitted through the infrared cut filter 101 is transmitted through the G filter 111B or the R filter 112B. The G filter 111B transmits green light because it exhibits the highest sensitivity in the green region. The R filter 112B transmits red light because it exhibits the highest sensitivity in the red region. As a result, most of the light input to the photodiode 111A is green light, and most of the light input to the photodiode 112A is red light.

  Next, the calculation of the heart rate by the calculation control unit 200 will be described. FIG. 4 is a functional block diagram of the biological information sensor 1. The arithmetic control unit 200 outputs a signal S0, which is a control signal, to the light emitting unit 10 in response to a measurement start instruction from the user. The light emitting unit 10 emits light in response to the signal S0, and emits white light to the human body. The white light emitted from the light emitting unit 10 is reflected in the human body and enters the G sensor 111 and the R sensor 112. At this time, the white light is absorbed by the skin, blood and the like, and the intensity of the reflected light fluctuates according to the pulse wave and body movement of the human body. Specifically, the intensity of green light contained in the reflected light fluctuates according to the pulse wave and body movement of the human body. The intensity of the red light contained in the reflected light fluctuates according to the movement of the human body, but hardly fluctuates according to the pulsation of the human body.

  The G sensor 111 receives light emitted from the light emitting unit 10 and reflected in the human body, and converts green light of the light into a signal S1. The level (for example, voltage) of the signal S1 increases in response to the light intensity of the incident green light. As mentioned above, the level of the signal S1 changes according to the pulsation and body movement of the human body.

  The R sensor 112 is emitted from the light emitting unit 10, receives light reflected in the human body, and converts red light of the light into a signal S2. The level (for example, voltage) of the signal S2 increases in accordance with the light intensity of the incident red light. As described above, the signal S2 changes according to the movement of the human body, but hardly changes according to the pulsation of the human body.

  The arithmetic control unit 200 may amplify at least one of the signals S1 and S2 such that the amplitudes of the body motion components that fluctuate in the same cycle among the signals S1 and S2 become substantially the same. The arithmetic and control unit 200 obtains a signal indicating the difference in level between the signal S1 and the signal obtained by amplifying the signal S2, and obtains a pulse wave of the human body based on the signal indicating the level difference.

  FIGS. 5A and 5B are time charts illustrating the operation of the biological information sensor 1. FIG. 5A illustrates the waveforms of the signals S1 and S2, and FIG. 5B illustrates the waveform of the signal S12 indicating the level difference between the signals S1 and S2. In FIGS. 5 (a) and 5 (b), the signal S1 includes a body motion component that fluctuates with a relatively large cycle and amplitude, and a pulse wave component that fluctuates with a relatively small cycle and amplitude, It contains the same body movement component. Signal S12 includes only pulse wave components.

  Referring back to FIG. 4, operation control unit 200 obtains a heart rate by counting the number of pulses per minute from signal S12, and displays signal S4 indicating the heart rate, for example, as a monitor of a wearable device. Output to unit 400. The display unit 400 displays characters, an image, and the like indicating the heart rate on the screen in accordance with the signal S4 from the calculation control unit 200. Communication with the display unit 400 may be performed by wire or may be performed wirelessly.

  As described above, according to the biological information sensor 1 according to the first embodiment, the infrared light contained in the light incident on the light receiving unit 11 is removed by the infrared light removal layer including the infrared cut filter 101. Therefore, the measurement accuracy of the heart rate measurement can be increased.

Second Embodiment
In the first embodiment, the case where the infrared light removal layer includes the infrared cut filter has been described. The infrared light removal layer is not limited to the case including the infrared cut filter. In the second embodiment, the case where the infrared light removal layer includes an infrared cut resin will be described.

  The second embodiment is different from the first embodiment only in that the infrared light removal layer includes an infrared cut resin instead of the infrared cut filter. The other configuration is the same as that of the first embodiment, and therefore the description of the same configuration will not be repeated.

  FIG. 6 is a cross-sectional view showing the configuration of the light receiving unit 11 provided in the biological information sensor 2 according to the second embodiment. Referring to FIG. 6, silicon substrate 12 is entirely covered with infrared cut resin 102. The spectral characteristics of the infrared cut resin 102 are substantially the same as those of the infrared cut filter. Therefore, as in the first embodiment, the infrared light contained in the light incident on the light receiving unit 11 can not pass through the infrared cut resin, and most of the light input to the photodiode 111A is green light, Most of the light input to the photodiode 112A is red light.

  As described above, according to the biological information sensor 2 according to the second embodiment, the infrared light contained in the light incident on the light receiving unit 11 is removed by the infrared light removal layer including the infrared cut resin 102 Therefore, the measurement accuracy of the heart rate measurement can be increased.

Third Embodiment
In the first embodiment, the case where the infrared light removal layer includes the infrared cut filter has been described, and in the second embodiment, the case where the infrared light removal layer includes the infrared cut resin has been described. That is, in the first and second embodiments, the case where the infrared light removal layer is one layer has been described. The infrared light removal layer is not limited to a single layer. In the third embodiment, a case will be described in which the infrared light removal layer includes an infrared cut filter and an infrared cut resin and has two layers.

  The third embodiment differs from the first embodiment only in that the infrared light removing layer includes an infrared cut resin in addition to the infrared cut filter. The other configuration is the same as that of the first embodiment, and therefore the description of the same configuration will not be repeated.

  FIG. 7 is a cross-sectional view showing the configuration of the light receiving unit 11 provided in the biological information sensor 3 according to the third embodiment. Referring to FIG. 7, in the third embodiment as well as in the first embodiment, infrared cut filter 101 is formed on the surface of upper layer 12A of silicon substrate 12, and G filter 111B and R filter 112B are provided. And Furthermore, in the third embodiment, the infrared cut resin 102 is laminated on the infrared cut filter 101. The infrared cut resin 102 covers the entire silicon substrate 12.

  With such a configuration, the infrared light contained in the light incident on the light receiving unit 11 can not pass through the infrared cut resin and the infrared cut filter, and most of the light input to the photodiode 111A is green light. Most of the light input to the diode 112A is red light.

  As described above, according to the biological information sensor 3 according to the third embodiment, the infrared light contained in the light incident on the light receiving unit 11 includes the infrared cut filter 101 and the infrared cut resin 102. Since it is removed by the light removal layer, it is possible to increase the measurement accuracy of the heart rate measurement.

  Further, since the infrared light removal layer is two layers, more infrared light can be removed as compared with the first embodiment and the second embodiment. As a result, it is possible to further improve the measurement accuracy of heart rate measurement.

Fourth Embodiment
In the first to third embodiments, the case of improving the measurement accuracy of the heart rate by using the infrared light removal layer has been described. Conventionally, since the blood oxygen saturation concentration (SpO2) has been measured using red light and infrared light, the infrared light is removed by the infrared light removing layer according to the first to third embodiments. In the embodiment, it is difficult to measure the blood oxygen saturation concentration living body (SpO2) by the conventional method. So, below, 4th Embodiment which can measure blood oxygen saturation concentration (SpO2) is provided, using an infrared-light removal layer by using green light.

  In the fourth embodiment, as in the first embodiment, the infrared light removal layer includes an infrared cut filter. In addition, the operation control unit 200 in the first embodiment is replaced with the operation control unit 300. Since the other configuration is the same as that of the first embodiment, the description of the same configuration will not be repeated.

  FIG. 8 is a functional block diagram of the biological information sensor 4 according to the fourth embodiment. Referring to FIG. 8, the operation control unit 300 includes a control unit 310, amplifiers 311 and 321, AD (Analog-to-Digital) converters 312 and 322, and a high-pass filter (HPF: High-Pass Filter). 313 and 323, low-pass filters (LPF: Low-Pass Filter) 314 and 324, and an operation unit 30.

  Control unit 310 outputs signal S0 as a control signal to light emitting unit 10 and operation unit 30 in response to a measurement start instruction from the user. Arithmetic unit 30 performs an operation necessary for calculating the blood oxygen saturation concentration in response to signal S0.

  The amplifier 311 amplifies the signal S1 output from the G sensor 111. The AD converter 312 converts the output signal of the amplifier 311 into a digital signal. The high pass filter 313 removes the DC component of the output signal of the AD converter 312. The low pass filter 314 removes noise components of the signal transmitted through the high pass filter 313. The signal transmitted through the low pass filter 314 is output to the computing unit 30 as a digital signal D1.

  The amplifier 321 amplifies the signal S2 output from the R sensor 112. The AD converter 322 converts the output signal of the amplifier 321 into a digital signal. The high pass filter 323 removes the DC component of the output signal of the AD converter 322. The low pass filter 324 removes noise components of the signal transmitted through the high pass filter 323. The signal transmitted through the low pass filter 324 is output to the computing unit 30 as a digital signal D2.

  Below, although operation part 30 which computes blood oxygen saturation concentration is explained, a calculation method of blood oxygen saturation concentration is explained roughly prior to the explanation concerned.

  FIG. 9 is a view showing the relationship between the wavelength [nm] of light, the molar absorption coefficient of hemoglobin [cm-1 / M], and the spectral sensitivity of the G filter 111B and the spectral sensitivity of the R filter 112B. In FIG. 9, H1 indicates the molar absorption coefficient of oxyhemoglobin, and H2 indicates the molar absorption coefficient of reduced hemoglobin. Further, Cg represents the spectral characteristic of the G filter 111B, and Cr represents the spectral characteristic of the R filter 112B. Oxidized hemoglobin is contained in blood in arteries, and reduced hemoglobin is contained in blood in veins.

  The blood oxygen saturation concentration is the ratio of the concentration of oxygenated hemoglobin to the concentration of oxygenated hemoglobin and the concentration and sum of oxygenated hemoglobin. Infrared light absorbs oxygenated hemoglobin more easily than reduced hemoglobin. This means that the molar absorption coefficient of oxygenated hemoglobin to infrared light is larger than the molar absorption coefficient of reduced hemoglobin to infrared light. Red light is more likely to absorb reduced hemoglobin than oxygenated hemoglobin. This means that the molar absorption coefficient of reduced hemoglobin to red light is larger than the molar absorption coefficient of oxyhemoglobin to red light. Conventionally, the blood oxygen saturation concentration has been determined using the difference between the properties of infrared light and red light. Referring to FIG. 9, although the molar absorption coefficient of oxyhemoglobin for infrared light having a wavelength of about 800 [nm] and the molar absorption coefficient of reduced hemoglobin are almost equal, the infrared light of the wavelength concerned is The blood oxygen saturation concentration can be determined by the calculation method. That is, if the light has a wavelength such that the molar absorption coefficient of oxyhemoglobin and the molar absorption coefficient of reduced hemoglobin are equal, the blood oxygen saturation concentration can be determined by the conventional calculation method.

  In the fourth embodiment, infrared light can not be used because infrared light is removed by the infrared light removing layer including the infrared cut filter. However, the molar absorption coefficient of oxyhemoglobin for green light of wavelength λ1 near 540 [nm] and the molar absorption coefficient of reduced hemoglobin are approximately equal. Therefore, in the fourth embodiment, the blood oxygen saturation concentration is calculated by using green light instead of infrared light.

  Next, the functional configuration of the calculation unit 30 will be described using FIG. Referring to FIG. 10, operation unit 30 has amplitude extraction units 31 and 32, signal ratio calculation unit 33, and SpO2 calculation unit 34.

  The amplitude extraction unit 31 extracts an amplitude value of the intensity of green light from the digital signal D1 from the G sensor 111, and outputs the amplitude value to the signal ratio calculation unit 33 as a digital signal D1L. The amplitude extraction unit 32 extracts an amplitude value of the intensity of red light from the digital signal D2 from the R sensor 112, and outputs the amplitude value to the signal ratio calculation unit 33 as a digital signal D2L. When the amplitude extractors 31 and 32 extract the amplitude value of the light intensity from the digital signal, the amplitude value may be amplified at a predetermined rate. The signal ratio calculation unit 33 calculates a ratio R (= V1 / V2) of the voltage value V1 of the digital signal D1L and the voltage value V2 of the digital signal D2L, and outputs the ratio R to the SpO2 calculation unit 34. The smaller the ratio between the voltage value V1 of the digital signal D1L and the voltage value V2 of the digital signal D2L, the larger the blood oxygen saturation concentration.

  The SpO2 calculation unit 34 obtains the blood oxygen saturation concentration based on the correspondence table of the ratio R and the blood oxygen saturation concentration, which is prepared in advance, and outputs the blood oxygen saturation concentration to the display unit 400. The correspondence table can be obtained in advance by actual machine experiments or simulations.

  As described above, according to the biological information sensor 4 according to the fourth embodiment, the blood oxygen saturation concentration can be measured while being provided with the infrared light removal layer. That is, according to the biological information sensor 4, the blood oxygen saturation concentration is measured while the measurement accuracy of heart rate measurement is increased by removing the infrared light which becomes noise when measuring the heart rate by the infrared light removal layer. It can also be done.

  In the fourth embodiment, the case where the infrared cut filter is included in the infrared light removal layer has been described. The infrared light removal layer in the case of measuring the blood oxygen saturation concentration is not limited to the case where the infrared cut filter is included. The infrared light removal layer in the case of measuring the blood oxygen saturation concentration can include, for example, an infrared cut resin as in the second embodiment, or an infrared light as in the third embodiment. A cut filter and an infrared cut resin can be included.

  In the first to fourth embodiments, the light emitting unit 10 that emits white light is used. However, since only green light and red light of white light are used, the light emitting unit 10 is replaced with green light. A green LED for emitting light and a red LED for emitting red light may be provided.

  In the first to fourth embodiments, although one light emitting unit 10 and one light receiving unit 11 are used, a plurality of light emitting units 10 and one light receiving unit 11 are used. Alternatively, one light receiving unit 11 may be provided at the center of the plurality of light emitting units 10.

  In the first to fourth embodiments, the infrared light removal layer is bonded to the silicon substrate 12. The infrared light removal layer does not necessarily have to be bonded to the silicon substrate 12, and may be formed anywhere as long as it is located on the optical path to the photodiode 111A and located on the optical path to the photodiode 112A. Absent. For example, it may be formed inside G sensor 111 and R sensor 112 which are optical sensors, and may be formed at a position away from silicon substrate 12.

  What is contained in the infrared light removal layer is not limited to the infrared cut filter and the infrared cut resin. If infrared light can be removed, it can be included in the infrared light removal layer.

  In the first embodiment, the second embodiment and the fourth embodiment, the case where the infrared light removing layer is one layer will be described, and in the third embodiment, the infrared light removing layer The case where the layer is two layers has been described. The infrared light removal layer is not limited to these cases, and may have three or more layers.

  In the first to fourth embodiments, the infrared light removing layer removes infrared light from light incident on the light receiving portion. For example, it can be said that infrared light is removed not only by an infrared cut filter or an infrared light removal layer containing an infrared cut resin but also by a color filter that transmits light of a predetermined wavelength. It can be said that the infrared light removing layer in the present invention further enhances the removal of infrared light which has been performed by the color filter.

  It goes without saying that according to the biological information sensor according to the embodiment, it is possible to detect the heart rate or the blood oxygen saturation concentration of a living body including humans and animals as well as the human body.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  1, 2, 3, 4 biometric information sensor, 10 light emitting unit, 11 light receiving unit, 12 silicon substrate, 12A upper layer, 12B lower layer, 13, 14 light shielding wall, 15, 16 lens, 17 transparent plate, 18 substrate, 30 arithmetic unit 31, 32 amplitude extraction unit, 33 signal ratio calculation unit, 34 SpO2 calculation unit, 50 human body, 101 infrared cut filter, 102 infrared cut resin, 111 G sensor, 112 R sensor, 111 A, 112 A photodiode, 111 B G Filter, 112 B R filter, 200, 300 arithmetic control unit, 310 control unit, 311, 321 amplifier, 312, 322 AD converter, 313, 323 high pass filter, 314, 324 low pass filter, 400 display unit, D1, D1L, D2L, D2 Digital signals, S0, S1, S2, S4, 12 signal, V1, V2 voltage value.

Claims (9)

A biological information sensor including a light receiving unit and generating information on a living body based on a signal from the light receiving unit,
The light receiving unit is
A first light sensor for converting a first light into a first signal ;
A second light sensor for converting the second light into a second signal;
A first substrate on which the first light sensor and the second light sensor are formed ;
The first light sensor is
A first photoelectric conversion element that converts the first light into the first signal;
And a first color filter formed on the light path to the first photoelectric conversion element and transmitting the first light.
The second light sensor is
A second photoelectric conversion element that converts the second light into the second signal;
And a second color filter formed on the light path to the second photoelectric conversion element and transmitting the second light.
The biological information sensor is
An infrared light removal layer formed on the optical path to the first photoelectric conversion element and formed on the optical path to the second photoelectric conversion element ;
And a calculation control unit that generates information related to the living body based on a signal from the light receiving unit.
The arithmetic control unit receives the first signal and the second signal from the light receiving unit, and generates information on the living body based on the first signal and the second signal.
The infrared light removal layer is formed on the surface of the first substrate,
The infrared light removal layer contains an infrared cut resin,
The biological information sensor, wherein the infrared cut resin covers the first substrate. A biological information sensor including a light receiving unit and generating information on a living body based on a signal from the light receiving unit,
The light receiving unit is
A first light sensor for converting a first light into a first signal;
A second light sensor for converting the second light into a second signal;
A first substrate on which the first light sensor and the second light sensor are formed;
The first light sensor is
A first photoelectric conversion element that converts the first light into the first signal;
And a first color filter formed on the light path to the first photoelectric conversion element and transmitting the first light.
The second light sensor is
A second photoelectric conversion element that converts the second light into the second signal;
And a second color filter formed on the light path to the second photoelectric conversion element and transmitting the second light.
The biological information sensor is
An infrared light removal layer formed on the optical path to the first photoelectric conversion element and formed on the optical path to the second photoelectric conversion element;
And a calculation control unit that generates information related to the living body based on a signal from the light receiving unit.
The arithmetic control unit receives the first signal and the second signal from the light receiving unit, and generates information on the living body based on the first signal and the second signal.
The infrared light removal layer is formed on the surface of the first substrate,
The infrared light removal layer includes an infrared cut filter and an infrared cut resin,
The infrared cut filter covers the first color filter and the second color filter.
The biological information sensor, wherein the infrared cut resin is laminated on the infrared cut filter and covers the first substrate. A light emitting unit that emits light including the first light and the second light;
A second substrate on which the light emitting unit, the light receiving unit, and the arithmetic control unit are formed;
A first light shielding wall formed to surround the light emitting unit and the light receiving unit along the outer periphery of the second substrate;
It further comprises a second light shielding wall that divides the space formed by the second substrate and the first light shielding wall into a space on the side where the light emitting portion is located and a space on the side where the light receiving portion is located;
The biological information sensor according to claim 1 or 2, wherein when the biological information sensor is attached to a living body, light reflected by the inside of the living body among the light enters the light receiving unit. The biological information sensor according to claim 3 , wherein the light emitting unit is a light emitting diode that emits white light. The first light is green light,
It said second light is a red light, the biometric information sensor according to claim 1 or 2. The arithmetic control unit generates information about the living body based on a difference between the level of the first signal level and the second signal, the biological information sensor according to claim 1 or 2. The biological information sensor according to claim 6 , wherein the information on the living body is a heart rate. The arithmetic control unit generates information about the living body on the basis of the ratio of the level of said first signal level and the second signal, the biological information sensor according to claim 1 or 2. The biological information sensor according to claim 8 , wherein the information on the living body is a blood oxygen saturation level.

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