JP2015173698A - Light detection unit and biological information detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light detection unit and a biological information detection device or the like that have high sensitivity and allow size reduction by mounting a light emission part properly on a substrate.SOLUTION: A light detection unit comprises a substrate 160, a light emission part 150 that emits light to an object, and a light receiving part 140 that is attached to the substrate 160 and receives light from the object. The substrate 160 is provided with a hole 169. The light emission part 150 is attached to the hole 169 of the substrate 160.

Description

  The present invention relates to a light detection unit, a biological information detection device, and the like.

  2. Description of the Related Art Conventionally, a biological information detection apparatus that detects biological information such as a human pulse wave is known. Patent Documents 1 and 2 disclose conventional techniques of a pulse meter which is an example of such a biological information detection apparatus. The pulse meter is attached to, for example, an arm, a wrist, a finger, or the like, and detects a pulsation derived from a heartbeat of a human body to measure a pulse rate.

  The pulsometers disclosed in Patent Documents 1 and 2 are photoelectric pulsometers, and the light detection unit includes a light emitting unit that emits light toward a subject that is an object, and light from the subject ( A light receiving portion that receives light having biological information). In this pulse meter, a pulse wave is detected by detecting a change in blood flow as a change in the amount of received light. Patent Document 1 discloses a pulse meter that is worn on the wrist, and Patent Document 2 discloses a pulse meter that is worn on a finger. Patent Document 3 discloses an optical sensor in which a light-shielding member is provided for a light receiving unit.

JP2011-139725A JP 2009-201919 A JP-A-6-273229

  In such a detection apparatus such as biological information, the light emitting unit of the light detection unit emits light to the object, and the light receiving unit receives light from the object, based on the detection signal obtained. Various information is detected. For this reason, improvement of the signal quality of a detection signal becomes an important subject.

  For such a problem, it is sufficient to improve the sensitivity of the light detection unit (sensor). For that purpose, it is effective to use an LED having a higher luminance and a narrower luminous flux angle as the light emitting unit. Conceivable. However, such an LED has a larger element than a conventional LED having a relatively low luminance and a wide luminous flux angle, and is particularly high in height. Therefore, there is a problem that it is difficult to downsize the module.

  According to some aspects of the present invention, it is possible to provide a light detection unit, a biological information detection device, and the like that are highly sensitive and can be miniaturized by appropriately mounting the light emitting unit on a substrate.

  One embodiment of the present invention includes a substrate, a light emitting unit that emits light to the object, and a light receiving unit that is attached to the substrate and receives light from the object, and the substrate has a hole. The light emitting unit is related to a light detection unit attached to the hole of the substrate.

  In one embodiment of the present invention, in a light detection unit having a light emitting part and a light receiving part, the light emitting part is attached to a hole provided in the substrate. As a result, even when the size of the light emitting unit is large, the light detection unit can be downsized.

  In the aspect of the invention, the light receiving unit is attached to the first surface of the substrate, and the light emitting unit is formed on the hole from the second surface side of the substrate that is the back surface of the first surface. It may be inserted into the part.

  This makes it possible to efficiently reduce the size of the light detection unit by utilizing the thickness of the substrate.

  In the aspect of the invention, the light emitting unit may include a lens unit that collects light, and the light emitting unit may be formed in the hole so that the lens unit protrudes toward the first surface. It may be inserted.

  This makes it possible to efficiently reduce the size of the light detection unit by utilizing the thickness of the substrate.

  In one embodiment of the present invention, the light emitting unit includes a light emitting element, an encapsulating part in which the light emitting element is enclosed, and a pedestal part that serves as a pedestal of the enclosing part, and the pedestal part includes: The light emitting unit may be provided on the second surface side in a state in which the light emitting unit is inserted into the hole.

  Thereby, it is possible to appropriately fix the light emitting unit to the substrate while realizing miniaturization.

  In the aspect of the invention, the pedestal portion includes a terminal electrically connected to the light emitting element, and the terminal is electrically connected to a wiring provided on the second surface of the substrate. May be.

  Thereby, it is possible to appropriately connect the light emitting unit to the substrate while realizing miniaturization.

  In one embodiment of the present invention, the substrate may be provided with a light shielding member that shields at least the light receiving portion.

  This makes it possible to suppress the incidence of light, which becomes a noise factor, on the light receiving unit.

  In the aspect of the invention, the light blocking member includes a light blocking wall that blocks light from the light emitting unit from entering the light receiving unit, and the height of the light blocking wall is h1. When the height of the light emitting unit is h2, h1 ≧ h2 may be satisfied.

  Accordingly, it is possible to shield direct light from the light emitting unit to the light receiving unit using the light shielding wall.

  In one embodiment of the present invention, when the height of the light receiving unit is h3, h1 ≧ h2> h3 may be satisfied.

  Accordingly, it is possible to shield direct light from the light emitting unit to the light receiving unit using the light shielding wall.

  In the aspect of the invention, the light shielding member may further include a diaphragm portion.

  This makes it possible to suppress the incidence of light, which becomes a noise factor, on the light receiving unit.

  In the aspect of the invention, the light shielding wall may be formed by sheet metal processing, and the narrowed portion may be formed by the sheet metal processing or injection molding.

  As a result, it is possible to form the light shielding wall and the stop portion by appropriate methods, respectively.

  Moreover, the other aspect of this invention is related with the biometric information detection apparatus containing said optical detection unit.

1A and 1B are comparative examples of the method of the present embodiment, and FIG. 1C is a side view illustrating a configuration example of the light detection unit of the present embodiment. The perspective view which shows the structural example of the photon detection unit of this embodiment. The figure explaining the difference of the detection signal level of the photon detection unit by the presence or absence of a lens part. 4A to 4E are a plan view and a side view showing a configuration example of the light detection unit of the present embodiment. FIGS. 5A and 5B are other side views showing a configuration example of the light detection unit of the present embodiment. The top view which shows the detailed shape of the member for light shielding, a side view, a front view, and a rear view. Explanatory drawing of the height of a light emission part, a light-receiving part, and a light-shielding wall. The figure which shows the relationship between the distance between a light emission part and a light-receiving part, and the signal strength of a detection signal. Explanatory drawing about the relationship between the distance of a light emission part and a light-receiving part, and the measurement distance in a depth direction. FIG. 10A and FIG. 10B are external views of the biological information detection apparatus of this embodiment. The external view of the biological information detection apparatus of this embodiment. Explanatory drawing about mounting | wearing with a biometric information detection apparatus, and communication with a terminal device. The functional block diagram of a biometric information detection apparatus. 14A and 14B are explanatory diagrams of the sensor unit.

  Hereinafter, this embodiment will be described. In addition, this embodiment demonstrated below does not unduly limit the content of this invention described in the claim. In addition, all the configurations described in the present embodiment are not necessarily essential configuration requirements of the present invention.

1. First, the method of this embodiment will be described. As described above, in the detection apparatus for biological information and the like, it is necessary to detect a high-quality signal in the light detection unit. For this purpose, it is effective to use a high-performance light emitting unit (for example, LED). Various viewpoints for evaluating the performance of the light emitting unit are conceivable. Here, it is assumed that the luminance is high and the light beam angle is narrow. In such a light emitting unit, strong light is irradiated to a more limited range, so that the intensity of reflected light reflected by, for example, a living body becomes strong, and as a result, the intensity of light received by the light receiving unit is increased. It can be strengthened.

  However, such a light emitting unit is larger in size than a light emitting unit with relatively low performance. In particular, when the direction perpendicular to the substrate surface is the height direction, the height is increased. 1A and 1B show an example of a light detection unit of a comparative example.

  1A is a cross-sectional view of the light detection unit of the first comparative example, and FIG. 1B is a cross-sectional view of the light detection unit of the second comparative example. The second comparative example is an example in which a high-performance light emitting unit is provided as compared with the first comparative example. As shown in FIGS. 1A and 1B, in any case, the light detection unit is provided with a substrate 160, a light receiving unit 140, a light emitting unit 150, and a light blocking member 70. In FIG. 1A and the like, the light shielding wall 100 of the light shielding member 70 is illustrated, but the light shielding member 70 may include the aperture portion 80 and the like. The light shielding member 70 blocks noise in the detection signal by shielding direct light from the light emitting unit 150 to the light receiving unit 140 and disturbance light.

  1A and 1B includes a lens 151, an enclosing portion 153 in which the light emitting element is enclosed, and a pedestal portion 155 that serves as a pedestal for the enclosing portion 153. However, as described above, the high-performance light-emitting portion 150 in FIG. 1B is larger in size and particularly high in comparison with FIG. Here, the height represents a length in a direction intersecting the substrate surface (a direction orthogonal in a narrow sense).

  Therefore, even in the first comparative example shown in FIG. 1A, the height is higher than that in the example using the light emitting part that does not have the lens part 151, as shown in FIG. In the light emitting unit 150 of the second comparative example, the height is further increased. There are two major disadvantages. First, since the light detection unit (and the device including the light detection unit) has a thickness, it is difficult to reduce the size. As will be described later with reference to FIG. 10A and the like, the biological information detection apparatus including the light detection unit is assumed to be a wearable device such as a wristwatch. In this case, since it is necessary for the user to keep wearing the device during the measurement period, it is a big problem that downsizing is difficult from the viewpoint of not discomforting the user or hindering the user's behavior. Become.

  Second, the difference in height between the light emitting unit 150 and the light receiving unit 140 is increased. How much the light detection unit can be brought closer to the object (a light irradiation target and a living body in a narrow sense) depends on the highest part of the light detection unit. In other words, if the height of the light emitting unit 150 is increased and the height of the light receiving unit 140 is too high, the light receiving unit 140 is sufficiently close to the target, no matter how close the light detection unit is to the target. I can't. As a result, the optical path until the reflected light from the object is received by the light receiving unit 140 becomes longer, and the level of the detection signal at the light receiving unit 140 decreases. Strictly speaking, it is assumed that the highest part of the light detection unit is not the light emitting unit 150 but the light shielding member 70. However, since the height of the light shielding member 70 is set to be equal to or higher than the height of the light emitting unit 150, the difference in height between the light emitting unit 150 and the light receiving unit 140 becomes a problem. .

  Here, the problem due to the difference in height can be solved by increasing the height of the light receiving unit 140, such as by providing a portion serving as a base in the light receiving unit 140. However, even in such a case, the problem that the light detection unit cannot be reduced in size cannot be dealt with.

  Therefore, the present applicant proposes a method of mounting the light emitting unit 150 on the substrate 160 as shown in FIG. Specifically, the light detection unit includes a substrate 160, a light emitting unit 150 that emits light to the object, and a light receiving unit 140 that is attached to the substrate 160 and receives light from the object. The hole 169 is provided, and the light emitting unit 150 is attached to the hole 169 of the substrate 160.

  In this way, the height of the light emitting unit 150 can be absorbed by an amount corresponding to the depth of the hole. Therefore, it is possible to reduce the size by suppressing the thickness (height) of the light detection unit itself, and as is clear from the comparison between FIGS. 1C and 1B, the light emitting unit 150 and the light receiving unit. The difference in height from 140 can also be reduced.

  Hereinafter, this embodiment will be described in detail. Specifically, a configuration example of the light detection unit will be described first, and then the light shielding member 70 will be described in detail. Finally, a specific example of a biological information detection apparatus including a light detection unit will be described.

2. Photodetection Unit FIG. 2 is a perspective view showing a configuration example of the photodetection unit of the present embodiment. As described above, the light detection unit of the present embodiment includes the substrate 160, the light receiving unit 140, the light emitting unit 150, and the light blocking member 70. 2 shows an example in which the enclosing portion 153 of the light emitting unit 150 protrudes toward the first surface (the surface on which the light receiving unit 140 is mounted). This is because, for example, when the thickness (height) of the enclosing portion 153 is thicker than that of the substrate 160, or as described later with reference to FIG. This corresponds to a case where the total thickness of the portion 155 is thick. However, as shown in FIG. 1C, the enclosing portion 153 may not protrude toward the first surface.

  The light emitting unit 150 emits light to an object (such as a subject), and the light receiving unit 140 receives light from the object. For example, when the light emitting unit 150 emits light and the light is reflected by the object, the light receiving unit 140 receives the reflected light. The light receiving unit 140 can be realized by a light receiving element such as a photodiode. The light emitting unit 150 can be realized by a light emitting element such as an LED. For example, the light receiving unit 140 can be realized by a PN junction diode element or the like formed on a semiconductor substrate. In this case, an angle limiting filter for narrowing the light receiving angle and a wavelength limiting filter for limiting the wavelength of light incident on the light receiving element may be formed on the diode element.

  For example, when applied to a biological information detection device such as a pulse meter, light from the light emitting unit 150 travels inside the subject, which is the object, and diffuses or scatters in the epidermis, dermis, subcutaneous tissue, and the like. Thereafter, this light reaches the blood vessel (detected site) and is reflected. At this time, part of the light is absorbed by the blood vessels. Then, the light absorption rate in the blood vessel changes due to the influence of the pulse, and the amount of reflected light also changes. Therefore, the light receiving unit 140 receives this reflected light and detects the change in the amount of light, thereby detecting biological information. It becomes possible to detect the pulse rate and the like.

  Note that a dome-shaped lens 151 (which is a condensing lens in a broad sense and is also referred to as a lens unit in the following) provided in the light emitting unit 150 is an LED chip that is resin-sealed (sealed with a light-transmitting resin) in the light emitting unit 150 It is a lens for collecting light from a light emitting element chip (hereinafter also referred to as a light emitting element in a broad sense). That is, in the surface-mounted light emitting unit 150, the LED chip is disposed below the dome-shaped lens 151, and the light from the LED chip is condensed by the dome-shaped lens 151 and emitted to the object. Thereby, the optical efficiency of the light detection unit can be improved.

  FIG. 3 shows the difference in the level of the detection signal of the light detection unit (here, the AC power of the pulse signal) depending on the presence or absence of the lens unit 151. Here, for each of three different users, the signal level was measured when the lens unit 151 was provided and when the lens unit 151 was not provided. As is clear from FIG. 3, although there is a difference in the degree of improvement in signal level, it was confirmed that the signal level was improved by providing the lens unit 151 for any user.

  A cross-sectional view of the light detection unit is as shown in FIG. 1C, the light receiving unit 140 is attached to the first surface of the substrate 160, and the light emitting unit 150 is connected to the back surface (opposite side) of the first surface. Is inserted into the hole 169 from the second surface side of the substrate.

  Here, since the substrate 160 has a thickness, even if it is a flat plate-shaped substrate, it is strictly a rectangular parallelepiped having six surfaces. However, the surface in the height direction (the surface expressed as the substrate 160 in FIG. 1C) has a very small area, and the arrangement of elements is not assumed. That is, when the flat substrate which is a rectangular parallelepiped has a width W × depth D × height H (W, D >> H here), the first and second surfaces have an area of W × D. Surface. In addition, there may be a substrate that is not a flat plate, such as a flexible substrate, but the first and second surfaces in this case (in this case, not necessarily a flat surface) are similarly areas in which elements are assumed to be arranged. It is sufficient to consider two broad aspects.

  As described above, the first surface here is a surface on the substrate 160 where the light receiving unit 140 is arranged, and is an upper surface in FIG. FIG. 4A shows the positional relationship between the light receiving unit 140 and the light emitting unit 150 on the first surface. In this case, the second surface is the lower surface in FIG. 1C, and the light emitting portion 150 is mounted from the lower side to the upper side of the hole 169 as shown in FIG. 1C. become. In this way, since the hole 169 having a depth corresponding to the thickness of the substrate is used, the height of the light emitting portion 150 can be absorbed by the thickness of the substrate.

  FIG. 4B shows an arrangement example of the light emitting units 150 on the second surface. As described above, since the light receiver 140 is provided on the first surface, it is not visually recognized from the second surface side. In the example of FIG. 4B, a connection land 168 is provided on the substrate 160, and the light emitting unit 150 is fixed to the land 168 by soldering.

  In addition, the light emitting unit 150 includes a lens unit 151 that collects light (the dome-shaped lens in the narrow sense), and the light emitting unit 150 has a hole so that the lens unit 151 protrudes toward the first surface side. It may be inserted into the part 169.

  For example, in FIG. 1C, most of the lens portion 151 protrudes to the upper surface of the substrate 160, that is, the first surface side. As described above, suppressing the height of the light emitting unit 150 is important in considering downsizing, but if it is too low, a difference in height between the light emitting unit 150 and the light receiving unit 140 becomes a problem. For example, when the tip of the lens unit 151 does not come out from the hole 169 to the first surface side, it is contrary to the above-described example, and the optical path length cannot be shortened because the light emitting unit 150 is lower than the light receiving unit 140. Challenges can arise. In consideration of the current thickness of the substrate 160 and the size of the light emitting unit 150, the lens unit 151 is naturally mounted so as to penetrate the substrate 160. That is, when the lens unit 151 is inserted into the hole 169 from the second surface side, the lens unit 151 protrudes to the first surface side.

  However, the mounting method of the light emitting unit 150 of the present embodiment is such that the hole 169 is provided so as to penetrate the substrate, and the light emitting unit 150 is inserted from the second surface side and protrudes to the first surface side. It is not limited. For example, as illustrated in FIG. 5A, a non-penetrating hole 169 is provided on the first surface side of the substrate 160, and the light emitting unit 150 is formed from the first surface side with respect to the hole 169. It may be inserted. In this case, although the absorbable height is smaller than that in FIG. 1C, there is an effect of suppressing the height of the light emitting unit 150 without projecting the pedestal 155 on the back surface.

  Further, as shown in FIG. 5B, the width of the pedestal portion 155 and the enclosing portion 153 in the cross-sectional view may be the same. With this configuration, the size of the hole 169 formed in the substrate 160 can be kept to the minimum necessary.

  5A or 5B, in the light-emitting portion 150, a terminal electrically connected to the light-emitting element may be provided on the bottom surface of the pedestal portion 155 or on the side surface. May be. The land 168 on the substrate 160 side is configured to be provided at a position corresponding to the terminal of the light emitting element, that is, at the bottom or side of the hole 169. Specifically, when the terminal and the land 168 are provided on the side surface, the connection is made in the region indicated by C1 in FIG. 5B, and when the terminal and the land 168 are provided on the bottom surface, FIG. ) In the area indicated by C2. By comprising in this way, the effect which suppresses the height of the light emission part 150 can be acquired, without making the base part 155 protrude on a back surface.

  Further, as shown in FIG. 1C, the light emitting unit 150 includes a light emitting element (not shown), an enclosing unit 153 in which the light emitting element is enclosed, and a pedestal unit 155 that serves as a base for the enclosing unit. May be. The pedestal 155 is provided on the second surface side in a state where the light emitting unit 150 is inserted into the hole 169. In particular, the base portion 155 may include a terminal that is electrically connected to the light emitting element, and the terminal may be electrically connected to a wiring provided on the second surface of the substrate 160.

  A specific example will be described with reference to the drawings. Since the enclosing portion 153 is a portion in which the light emitting element is encapsulated, the lens portion 151 is positioned closer to the object than the enclosing portion. Moreover, since the base part 155 becomes a base of the enclosure part 153, it is located in the direction side different from a target object. That is, as shown in FIG. 1C and the like, the light emitting unit 150 is arranged in the order of the lens unit 151, the enclosing unit 153, and the pedestal unit 155 along the direction from the object side to the substrate 160, and the element is mounted. In consideration of the stability at the time, the sectional area of each part is generally such that the lens part 151 <the enclosed part 153 <the pedestal part 155 as shown in FIG.

  And when inserting such a light emission part 150 into the hole part 169 from the 2nd surface side, it is not prevented that the whole including the base part 155 is inserted into the hole part 169, but to FIG.1 (C). As shown, the pedestal 155 may be left on the second surface side. In this way, the light emitting unit 150 can be easily fixed to the substrate 160, and the portion of the light emitting unit 150 that protrudes to the first surface side can be reduced. Therefore, the height of the light emitting unit 150 and the light receiving unit 140 can be increased. The difference in thickness can be reduced.

  In such a light-emitting portion 150, it is common to provide terminals that are electrically connected to the light-emitting elements in the pedestal portion 155. For example, among the pedestal portions 155, the terminals are indicated by P1 and P2 in FIG. A terminal is provided at the position. When the terminals P1 and P2 have terminals, the light-emitting portion 150 is inserted in the state of FIG. 1C, so that P1 and P2 are in contact with the second surface of the substrate 160 as shown in FIG. Position. That is, if wiring is provided at an appropriate position on the second surface side of the substrate 160, connection with the terminal of the light emitting unit 150 is easy.

  For example, FIG. 4D is a view of the substrate 160 in a state where the light emitting portion 150 is not inserted, as viewed from the second surface side, but is connected to the periphery of the hole portion 169 as shown in FIG. A land 168 is provided. FIG. 4E is a cross-sectional view of the substrate 160 in a state where the light emitting unit 150 is not inserted. In such an arrangement, if the light emitting unit 150 is inserted into the hole 169 as shown in FIG. 4C, the terminals P1 and P2 provided with terminals and the land 168 appropriately correspond to each other. Therefore, the light emitting unit 150 can be easily mounted on the substrate 160 by soldering as shown in FIG.

  The light blocking member 70 is a member for blocking light. For example, in FIG. 2, the light blocking member 70 blocks the light receiving unit 140. That is, the light blocking member 70 is not provided on the light emitting unit 150 side, but is provided on the light receiving unit 140 side. For example, the light blocking member 70 is provided so as to cover the light receiving unit 140 and blocks light incident on the light receiving unit 140, but the light emitting unit 150 is not shielded. However, a modification in which the light shielding member 70 is provided on the light emitting unit 150 side is also possible.

  It is desirable to perform reflection suppression processing on at least the inner surface of the light shielding member 70. For example, the color of the surface (inner side surface, etc.) of the light shielding member 70 is set to a predetermined color such as black so as to prevent irregular reflection of light. Alternatively, the surface of the light shielding member 70 may have a moth-eye structure. For example, an uneven structure having a period of several tens to several hundreds of nanometers is formed on the surface to form an antireflection structure. By performing such reflection suppression processing, for example, it is possible to effectively suppress the situation where reflected light on the surface of the light shielding member 70 becomes stray light and becomes a noise component of the detection signal.

  The light receiving unit 140, the light emitting unit 150, and the light shielding member 70 are mounted on the substrate 160. The substrate 160 is, for example, a rigid substrate. The board 160 is provided with a terminal 162 for connecting to a signal / power terminal 142 of the light receiving unit 140 and a terminal 164 for connecting a signal / power to an external main board. For example, the terminal 142 of the light receiving unit 140 and the terminal 162 of the substrate 160 are connected by wire bonding or the like.

  In this embodiment, the light shielding member 70 is formed by, for example, sheet metal processing of a metal (for example, an alloy of tin and copper). For example, the light shielding member 70 having a shape as shown in FIG. 2 is formed by processing a single metal plate. The light shielding member 70 includes a light shielding wall 100 provided between the light emitting unit 150 and the light receiving unit 140. The light shielding wall 100 shields light (direct light or the like) from the light emitting unit 150 from entering the light receiving unit 140. The light shielding wall 100 is formed by the first metal surface 71 of the light shielding member 70 formed by sheet metal processing. That is, the first metal surface 71 to be the light shielding wall 100 is provided between the light receiving unit 140 and the light emitting unit 150, thereby suppressing the light from the light emitting unit 150 from entering the light receiving unit 140. Is done.

  The light shielding member 70 has second and third metal surfaces 72 and 73. These second and third metal surfaces 72 and 73 are provided along a direction intersecting (for example, orthogonal to) the first metal surface 71. For example, when the first metal surface 71 is a front-side metal surface, the second and third metal surfaces 72 and 73 are side-side metal surfaces and serve as side-side light shielding walls.

  As shown in FIG. 2, the first end surface (left end surface) indicated by D <b> 1 of the first metal surface 71 is the second metal in the front view when the first metal surface 71 is viewed from the light emitting unit 150 side. It protrudes to one side (left side) from the end surface indicated by D3 of the surface 72. On the other hand, the second end surface (the right end surface) indicated by D2 that faces the first end surface of the first metal surface 71 is more than the end surface indicated by D4 of the third metal surface 73 in the front view. It protrudes on the other side (right side) different from one side. That is, the end surfaces indicated by D1 and D2 of the first metal surface 71 protrude on both sides from the end surfaces indicated by D3 and D4 of the second and third metal surfaces.

  For example, the first metal surface 71 and the second metal surface 72 are provided adjacent to each other via a first gap region indicated by E1 in FIG. The first metal surface 71 and the third metal surface 73 are provided adjacent to each other through the second gap region. That is, the back surface of the first metal surface 71 is not in contact with the end surfaces indicated by D3 and D4 of the second and third metal surfaces, and there is a gap region between the back surface and the end surface. .

  If such a gap region exists, there is a possibility that light from the light emitting unit 150 may enter the light receiving unit 140 through the gap region as will be described in detail later. However, in the present embodiment, since the end surfaces indicated by D1 and D2 of the first metal surface 71 protrude from the second and third metal surfaces 72 and 73 on both sides in the front view as described above, Such a situation where the light from the light emitting unit 150 is incident on the light receiving unit 140 can be effectively suppressed.

  The light blocking member 70 includes a fourth metal surface 74 that is provided along a direction intersecting (for example, orthogonal to) the first metal surface 71 and blocks light incident on the light receiving unit 140. The fourth metal surface 74 is a metal surface on the upper surface of the light shielding member 70, for example.

  The fourth metal surface 74 is formed with a diaphragm portion 80 that restricts light (reflected light or the like) from the object in the optical path between the object and the light receiving unit 140. In other words, the opening 81 of the aperture 80 is formed in the fourth metal surface 74. The light shielding member 70 is also provided with a fifth metal surface 75 serving as a light shielding wall on the back surface, and shields light incident from the back surface side.

3. Light Shielding Member As shown in FIGS. 1C and 2, the substrate 160 is provided with a light shielding member 70 that shields at least the light receiving portion 140. Hereinafter, the light shielding member 70 will be described.

3.1 Sheet Metal Processing In the light detection unit of the present embodiment, as shown in FIG. 2, a light blocking member 70 for blocking the light receiving unit 140 and the like from external light is provided. The light shielding member 70 is formed by processing a metal sheet metal, and the light shielding wall 100 is realized by, for example, the metal surface 71 of the light shielding member 70. In addition, for example, the metal surface 74 of the light blocking member 70 realizes the aperture 80 having the opening 81. Here, the light shielding wall 100 has, for example, a wall surface along a direction intersecting (orthogonal) with a line segment connecting the center position of the light receiving unit 140 and the center position of the light emitting unit 150. By providing such a light shielding wall 100, the light (direct light) from the light emitting unit 150 is prevented from entering the light receiving unit 140, and the reliability of the detection data can be improved.

  As will be described in detail later, as the distance between the light emitting unit 150 and the light receiving unit 140 is shorter, the optical efficiency and performance of the light detection unit is improved. For example, the optical efficiency / performance decreases in inverse proportion to the square of the distance. Therefore, it is desirable to make the distance between the light emitting unit 150 and the light receiving unit 140 as close as possible.

  On the other hand, when the distance between the light emitting unit 150 and the light receiving unit 140 is shortened, direct light from the light emitting unit 150 enters the light receiving unit 140, causing an increase in DC component and the like, resulting in a decrease in performance. For this reason, in the light detection unit of this embodiment, the light shielding wall 100 is provided between the light receiving unit 140 and the light emitting unit 150.

  In this case, as a method of the comparative example of the present embodiment, a method of forming the light shielding wall 100 of the light shielding member 70 by injection molding can be considered. The method of the comparative example using injection molding is an advantageous method from the viewpoint of mass productivity of equipment.

  However, when the light shielding wall 100 is formed by injection molding, the wall thickness of the light shielding wall 100 is increased. That is, if the wall thickness of the light shielding wall 100 is designed to be thin, the portion of the light shielding wall 100 is not sufficiently filled during injection molding, and the light shielding wall 100 having sufficient strength cannot be realized. For this reason, in the method of the comparative example using injection molding, the thickness of the light shielding wall 100 becomes, for example, 0.4 mm or more.

  And when the light shielding wall 100 becomes thick in this way, the distance between the light emission part 150 and the light-receiving part 140 will also become long. Accordingly, for example, the optical path length through the object between the light emitting unit 150 and the light receiving unit 140 becomes long, and the optical efficiency and performance of the light detection unit are lowered.

  Therefore, in this embodiment, the light shielding member 70 is formed by metal sheet metal processing. For example, FIG. 6 is a plan view, a side view, a front view, and a rear view showing the detailed shape of the light shielding member 70. For example, a light shielding member 70 composed of the metal surfaces 71, 72, 73, 74, and 75 is formed by bending a single metal plate by sheet metal processing. Specifically, the light shielding member 70 is formed by bending the metal surfaces 71, 72, 73, and 75 at right angles (substantially right angles) with respect to the metal surface 74 that is the upper surface.

  In FIG. 2, the metal surface 71 facing the light emitting unit 150 serves as a light shielding wall 100 that blocks direct light from the light emitting unit 150 from entering the light receiving unit 140. In addition, the upper metal surface 74 is formed with a diaphragm unit 80 that squeezes light from the object in the optical path between the object and the light receiving unit 140. That is, the aperture 80 having the opening 81 is formed.

  Thus, if the light shielding wall 100 is realized using the metal surface 71 by sheet metal processing, the thickness of the light shielding wall 100 can be reduced as compared with the method of the comparative example using injection molding. For example, when sheet metal processing is used, the light shielding member 70 having sufficient strength can be realized even if the thickness of the metal surface is about 0.1 mm, for example. For this reason, the thickness of the metal surface 71 used as the light shielding wall 100 can also be made into about 0.1 mm, for example. Therefore, compared with the method of the comparative example using the injection molding in which the thickness of the light shielding wall 100 becomes, for example, 0.4 mm or more, the thickness of the light shielding wall 100 can be sufficiently reduced. The distance between the light receiving units 140 can also be shortened. Therefore, the light path length of the light through the object from the light emitting unit 150 to the light receiving unit 140 can be shortened while suppressing the direct light from the light emitting unit 150 from being incident on the light receiving unit 140 by the light shielding wall 100. The detection performance of the light detection unit can be improved.

  In particular, in FIG. 2, a chip package type light emitting unit 150 is used. In the chip package type light emitting unit 150, for example, the dome-shaped lens 151 is arranged on the LED chip, so that the light emission efficiency to the object is increased and the detection sensitivity of the light detection unit can be increased. .

  However, the chip package type light emitting unit 150 has a larger layout occupation area compared to, for example, a type realized by arranging an LED chip on a reflector. Therefore, there is a problem that the distance between the light emitting unit 150 and the light receiving unit 140 is increased accordingly. In this respect, according to the present embodiment, since the thickness of the light shielding wall 100 can be sufficiently reduced as described above, even when such a light emitting unit 150 of the chip package type is used, this can be dealt with. This makes it possible to improve the detection performance such as the sensitivity of the light detection unit.

  In FIG. 2, the light blocking member 70 is not provided on the light emitting unit 150 side but is provided only on the light receiving unit 140 side. That is, the light shielding member 70 covers the light receiving unit 140 and shields it, but does not cover the light emitting unit 150.

  For example, when the light shielding member 70 is shaped so as to also shield the light emitting unit 150, part of the light traveling from the light emitting unit 150 to the target is blocked by the light shielding member 70, and the target is irradiated. The amount of light emitted may decrease, and the detection performance such as sensitivity may decrease.

  In this regard, as shown in FIG. 2, if the shape of the light shielding member 70 is made such that only the light receiving portion 140 side is shielded, the light emitted from the light emitting portion 150 is blocked by the light shielding member 70 and the object. It is possible to suppress the occurrence of a situation where the amount of light to the light decreases.

  In addition, the configuration in which the light blocking member 70 is not provided on the light emitting unit 150 side but only on the light receiving unit 140 side is advantageous from the viewpoint of reducing the thickness of the light detection unit. As described above, the height of the light emitting unit 150 having the dome-shaped lens 151 (particularly, the light emitting unit 150 having high brightness and a narrow beam angle) is higher than that of the light receiving unit 140. And even if it mounts with respect to the hole part 169 shown in FIG.1 (C) etc., it is common that the height of the light emission part 150 becomes higher than the light-receiving part 140. FIG. Therefore, when the light blocking member 70 is provided on the light emitting unit 150 side, the height on the light emitting unit 150 side is increased accordingly, which hinders the thinning of the light detection unit.

  In this regard, if the light blocking member 70 is provided only on the light receiving unit 140 side, the light blocking unit 70 does not exist on the light emitting unit 150 side. It is possible to align the height. Therefore, the height of the light detection unit as a whole can be reduced as compared with the method of providing the light blocking member 70 on the light emitting unit 150 side, and the light detection unit can be easily made thin.

  Further, as described above, the light blocking member 70 is provided with the aperture portion 80. That is, the opening 81 is formed in the metal surface 74 on the upper surface of the light shielding member 70, and the aperture 80 is realized by the opening 81. In this case, the opening 81 of the aperture 80 is wider as it is closer to the light emitting unit 150. For example, the opening 81 has a semicircular shape (substantially semicircular shape), and the diameter of the semicircle is located on the light emitting unit 150 side. If the opening 81 of the aperture 80 is formed in such a shape, the light emitted from the light emitting unit 150 and reflected by the object can be efficiently incident on the light receiving unit 140, and the sensitivity and the like can be detected. Performance can be improved. Details of the aperture 80 will be described later.

  The relationship between the height of the light shielding wall 100 and the height of the light receiving unit 140 and the light emitting unit 150 in the light shielding member 70 will be described. As described above, the light blocking member 70 includes the light blocking wall 100 that blocks light from the light emitting unit 150 from entering the light receiving unit 140. When the height of the light shielding wall 100 is h1 and the height of the light emitting unit 150 is h2, h1 ≧ h2.

  The height here refers to a length in a height direction from the reference (a direction intersecting the substrate 160 and, in a narrow sense, an orthogonal direction) with a given point as a reference. For example, when the first surface of the substrate 160 is used as a reference, the height h1 of the light shielding wall 100 and the height h2 of the light emitting unit 150 are the heights shown in FIG. That is, the height here does not represent the thickness of the light emitting unit 150 itself (h2 'in FIG. 7).

  The light shielding wall 100 here shields direct light from the light emitting unit 150 to the light receiving unit 140. The minimum height of the light shielding wall 100 necessary for directly shielding light depends on the height of the light receiving unit 140, the distance between the light emitting unit 150 and the light receiving unit 140, etc., but at least the light emitting unit. If the height is 150 or more, direct light can be blocked. Therefore, the height relationship is set here so that h1 ≧ h2. At this time, when the height of the light receiving unit 140 is h3, it is preferable that h1 ≧ h2> h3. This condition can be realized by using the light emitting unit 150 and the light receiving unit 140 having a general size. However, in order to eliminate the height difference as described above, a pedestal is provided in the light emitting unit 150. If you take action, it is not necessarily guaranteed. However, when h2 ≦ h3, depending on the arrangement position and angle, even if the requirement of h1 ≧ h2 is satisfied, the light may not be directly shielded. In that respect, if h1 ≧ h2> h3, it is possible to satisfy the condition that light is easily shielded directly.

  In the above description, the light shielding member 70 is formed by sheet metal processing for both the light shielding wall 100 and other portions (for example, the aperture 80), but is not limited thereto. For example, the light shielding wall 100 may be formed by sheet metal processing, and the aperture 80 may be formed by sheet metal processing or injection molding.

  As will be described later, the distance between the light emitting unit 150 and the light receiving unit 140 is preferably within a predetermined range. Therefore, in order to be able to set the distance flexibly, the thickness of the light shielding wall 100 provided between the light emitting unit 150 and the light receiving unit 140 is preferably thin. In the above-described sheet metal processing, since the member can be formed thin, the light shielding wall 100 may be formed by sheet metal processing.

  However, the diaphragm 80 provided on the light-shielding member 70 above the light-receiving unit 140 (when the user is worn, on the living body side of the light-receiving unit 140) does not cause a big problem even if the thickness is slightly increased. This is because although the increase in thickness leads to an increase in the height of the device, the height of the light emitting unit 150 is generally higher than the height of the light receiving unit 140 as described above. Therefore, the size of the light detection unit should be determined based on the light emitting unit 150 when the diaphragm 80 provided on the light receiving unit 140 side becomes thick. In consideration of the above, the narrowed portion 80 may be formed by sheet metal processing, but may be formed by injection molding that increases the thickness as compared with sheet metal processing.

3.2 Distance between Light Emitting Unit and Light Receiving Unit FIG. 8 is a diagram illustrating the relationship between the distance LD between the light emitting unit 150 and the light receiving unit 140 and the signal intensity. Here, the signal intensity is the intensity of the detection signal of the detection apparatus to which the light detection unit of the present embodiment is applied. For example, when a light detection unit is applied to a biological information detection device such as a pulse wave, which will be described later, the intensity of a biological information detection signal such as a pulse wave. The distance LD between the light emitting unit 150 and the light receiving unit 140 is, for example, the distance between the light emitting unit 150 and the center position (representative position) of the light receiving unit 140. For example, when the light receiving unit 140 has a rectangular shape (substantially rectangular shape), the position of the light receiving unit 140 is the center position of the rectangular shape. In addition, when the light emitting unit 150 includes the dome-shaped lens 151 as described above, the position of the light emitting unit 150 is, for example, the center position of the dome-shaped lens 151 (the position of the LED chip).

  As is apparent from FIG. 8, the closer the distance LD between the light emitting unit 150 and the light receiving unit 140 is, the higher the signal intensity of the detection signal is and the detection performance such as sensitivity is improved. Accordingly, it is desirable that the distance LD between the light emitting unit 150 and the light receiving unit 140 is as short as possible.

  In this regard, in this embodiment, as shown in FIGS. 2 and 6 described above, the light shielding member 70 is formed by processing a metal sheet metal, and the light shielding wall 100 is realized by the metal surface 71. Therefore, compared with the case where the light shielding member 70 is realized by injection molding, the thickness of the light shielding wall 100 can be reduced, for example, about 0.1 mm. Therefore, the distance LD between the light-emitting unit 150 and the light-receiving unit 140 can be made closer by the reduction in the thickness of the light shielding wall 100, and the detection performance of the detection device can be improved as is apparent from FIG.

  In this case, as shown in FIG. 8, the distance between the light receiving unit 140 and the light emitting unit 150 is preferably LD <3 mm. For example, as is apparent from the tangent line G2 on the longer distance side in the characteristic curve G1 in FIG. 8, the characteristic curve G1 is saturated in the range where LD ≧ 3 mm. On the other hand, in the range of LD <3 mm, the signal intensity greatly increases as the distance LD becomes shorter. Therefore, in this sense, it is desirable that LD <3 mm.

  Further, it is desirable that the distance LD is LD <2.5 mm. For example, as can be understood from the relationship between the tangent line G2 on the larger side and the tangent line G3 on the smaller side, the rate of increase in signal strength with respect to the distance is even higher in the range where the distance is LD <2.5 mm (2.4 mm). It has become. Therefore, in this sense, it is more desirable that LD <2.5 mm.

  In the light detection unit of the present embodiment shown in FIGS. 2 and 6, for example, the distance LD is about LD = 2.0 mm. Therefore, as shown in FIG. 8, the detection performance can be greatly improved as compared with the conventional light detection unit in which LD ≧ 3 mm.

  There is also a lower limit for the distance LD, and it is not desirable to make the distance LD too close. For example, FIG. 9 is a diagram illustrating a case where the light detection unit of the present embodiment is applied to a detection apparatus for biological information such as pulse waves. In this case, the light from the light emitting unit 150 is diffused or scattered in the blood vessel or the like of the subject, and the light is incident on the light receiving unit 140 to detect a pulse wave. In FIG. 9, a relationship of LD = 2 × LB is generally established between the distance LD between the light emitting unit 150 and the light receiving unit 140 and the measurement distance LB in the depth direction. For example, the measurement limit distance by the light detection unit composed of the light emitting unit 150 and the light receiving unit 140 separated by the distance LD is about LB = LD / 2. In the range where the distance LB is, for example, 100 μm to 150 μm, there is no blood vessel serving as a pulse wave detection target. Therefore, when the distance LD becomes LD ≦ 2 × LB = 2 × 100 μm to 2 × 150 μm) = 0.2 mm to 0.3 mm, the pulse wave detection signal is expected to be extremely small. That is, as the distance LD becomes shorter, the measurement distance LB in the depth direction also becomes smaller accordingly, and if there is no detection target in the range of the distance LB, the detection signal becomes extremely small. That is, the closer the distance LD is, the better the detection performance is, but there is also a limit, and there is a lower limit value. Therefore, in this sense, it is desirable that LD> 0.3 mm. That is, it is desirable that 0.3 mm <LD <2.5 mm (or 0.3 mm <LD <3.0 mm).

4). 4. Biological Information Detection Device 4.1 Overall Configuration Example of Biological Information Detection Device FIGS. 10A, 10B, and 11 are external views of the biological information detection device (biological information measurement device) of this embodiment. 10A is a diagram of the biological information detection device viewed from the front side, FIG. 10B is a diagram viewed from the upper side, and FIG. 11 is a diagram viewed from the side.

  As shown in FIGS. 10A to 11, the biological information detection apparatus of this embodiment includes a band unit 10, a case unit 30, and a sensor unit 40. The case part 30 is attached to the band part 10. The sensor unit 40 is provided in the case unit 30. In addition, the biological information detection apparatus includes a processing unit 200 as shown in FIG. The processing unit 200 is provided in the case unit 30 and detects biological information based on a detection signal from the sensor unit 40. In addition, the biological information detection apparatus of this embodiment is not limited to the structure of FIG. 10 (A)-FIG. 11, A part of the component is abbreviate | omitted, it replaces with another component, Other components are replaced. Various modifications such as addition are possible.

  Note that the above-described light detection unit is included in the sensor unit 40. For example, the sensor unit 40 includes a substrate 160, a light emitting unit 150, a light receiving unit 140, a light shielding member 70, and a diaphragm unit 80 (80-1 and 80-2), as will be described later with reference to FIG. It is comprised from a photon detection unit and another member. In the example of FIG. 14, the other members are a convex portion 52, a groove portion 54, a concave portion 56, a pressing suppression portion 58, and the like realized by the light transmissive member 50. However, the light detection unit according to the present embodiment includes these members, that is, the sensor unit 40 as a whole can correspond to the light detection unit.

  The band unit 10 is for wrapping around the wrist of the user and mounting the biological information detection device. The band part 10 has a band hole 12 and a buckle part 14. The buckle portion 14 has a band insertion portion 15 and a projection portion 16. The user inserts one end side of the band unit 10 into the band insertion unit 15 of the buckle unit 14, and inserts the projection 16 of the buckle unit 14 into the band hole 12 of the band unit 10, so that the biological information detection device is attached to the wrist. Attach to. In this case, depending on which band hole 12 the protrusion 16 is inserted into, the magnitude of the pressing (pressing on the wrist surface) of the sensor unit 40 described later is adjusted.

  The case part 30 corresponds to a main body part of the biological information detection device. Various components of the biological information detection device such as the sensor unit 40 and the processing unit 200 are provided inside the case unit 30. That is, the case part 30 is a housing for housing these components. The case portion 30 includes, for example, a top case 34 and a bottom case 36. The case portion 30 may not be separated from the top case 34 and the bottom case 36.

  The case part 30 is provided with a light emitting window part 32. The light emitting window 32 is formed of a light transmissive member. The case unit 30 is provided with a light emitting unit (LED, a light emitting unit for notification different from the light emitting unit 150 of the light detection unit) mounted on the flexible substrate, and light from the light emitting unit is transmitted to the light emitting window. The light is emitted to the outside of the case part 30 through the part 32.

  As shown in FIG. 11, the case portion 30 is provided with a terminal portion 35. When the biological information detection device is mounted on a cradle (not shown), the terminal part of the cradle and the terminal part 35 of the case part 30 are electrically connected. Thereby, the secondary battery (battery) provided in the case part 30 can be charged.

  The sensor unit 40 detects biological information such as a pulse wave of the subject. For example, the sensor unit 40 includes a light receiving unit 140 and a light emitting unit 150 as shown in FIGS. 13 and 14A described later. The sensor unit 40 includes a convex portion 52 that is formed of a translucent member and that makes contact with the skin surface of the subject to apply pressure. In this state, the light emitting unit 150 emits light with the convex portion 52 pressing against the skin surface, and the light receiving unit 140 receives the light reflected by the subject (blood vessel), and the light reception result. Is output to the processing unit 200 as a detection signal. The processing unit 200 detects biological information such as a pulse wave based on the detection signal from the sensor unit 40. The biological information to be detected by the biological information detection device of the present embodiment is not limited to the pulse wave (pulse rate), and the biological information detection device can detect biological information other than the pulse wave (for example, oxygen saturation in blood). , Body temperature, heart rate, etc.).

  FIG. 12 is an explanatory diagram regarding the mounting of the biological information detection device 400 and the communication with the terminal device 420.

  As shown in FIG. 12, the user who is the subject wears the biological information detecting device 400 on the wrist 410 like a watch. As shown in FIG. 11, a sensor unit 40 is provided on the surface of the case unit 30 on the subject side. Therefore, when the biological information detection device 400 is attached, the convex portion 52 of the sensor unit 40 contacts and presses the skin surface of the wrist 410, and in this state, the light emitting unit 150 of the sensor unit 40 emits light, When the light receiving unit 140 receives the reflected light, biological information such as a pulse wave is detected.

  The biological information detection device 400 and the terminal device 420 are connected for communication so that data can be exchanged. The terminal device 420 is a portable communication terminal such as a smartphone, a mobile phone, or a future phone. Alternatively, the terminal device 420 may be an information processing terminal such as a tablet computer. As a communication connection between the biological information detection device 400 and the terminal device 420, proximity wireless communication such as Bluetooth (registered trademark) can be employed. In this way, the biological information detection device 400 and the terminal device 420 are communicatively connected, so that various information such as the pulse rate and calorie consumption can be displayed on the display unit 430 (LCD or the like) of the terminal device 420. That is, various information obtained based on the detection signal of the sensor unit 40 can be displayed. Note that the calculation processing of information such as the pulse rate and calorie consumption may be executed by the biological information detection device 400, or at least a part thereof may be executed by the terminal device 420.

  The biological information detection apparatus 400 is provided with a light emitting window 32, and notifies various types of information to the user by light emission (lighting and blinking) of the light emitting unit for notification. For example, when entering the fat combustion zone or exiting from the fat combustion zone, this is notified by the light emission of the light emitting part through the light emission window part 32. When the terminal device 420 receives a mail or the like, the terminal device 420 notifies the biological information detection device 400 of it. Then, the light emitting unit of the biological information detecting device 400 emits light, so that the user is notified of reception of e-mail or the like.

  In this way, in FIG. 12, the biological information detection device 400 is not provided with a display unit such as an LCD, and information that needs to be notified with characters, numbers, or the like is displayed on the display unit 430 of the terminal device 420. . As described above, in FIG. 12, the living body information detection apparatus 400 is reduced in size by notifying a user of necessary minimum information by light emission of the light emitting unit without providing a display unit such as an LCD. In addition, since the display unit is not provided in the biological information detection apparatus 400, the appearance of the biological information detection apparatus 400 can be improved.

  FIG. 13 shows a functional block diagram of the biological information detection apparatus of this embodiment. In FIG. 13, the biological information detection apparatus includes a sensor unit 40, a body motion sensor unit 170, a vibration generation unit 180, a processing unit 200, a storage unit 240, a communication unit 250, an antenna 252, and a notification unit 260. Note that the biological information detection apparatus according to the present embodiment is not limited to the configuration shown in FIG. 13, and various modifications such as omitting some of the components, replacing them with other components, and adding other components. Implementation is possible.

  The sensor unit 40 detects biological information such as a pulse wave, and includes a light receiving unit 140 and a light emitting unit 150. A pulse wave sensor (photoelectric sensor) is realized by the light receiving unit 140, the light emitting unit 150, and the like. The sensor unit 40 outputs a signal detected by the pulse wave sensor as a pulse wave detection signal.

  The body motion sensor unit 170 outputs a body motion detection signal that is a signal that changes according to body motion, based on sensor information of various sensors. The body motion sensor unit 170 includes, for example, an acceleration sensor 172 as a body motion sensor. The body motion sensor unit 170 may include a pressure sensor, a gyro sensor, or the like as the body motion sensor.

  The processing unit 200 performs various signal processing and control processing using the storage unit 240 as a work area, for example, and can be realized by a processor such as a CPU or a logic circuit such as an ASIC. The processing unit 200 includes a signal processing unit 210, a pulsation information calculation unit 220, and a notification control unit 230.

  The signal processing unit 210 performs various types of signal processing (filter processing and the like). For example, the signal processing unit 210 performs signal processing on a pulse wave detection signal from the sensor unit 40, a body motion detection signal from the body motion sensor unit 170, and the like. Do. For example, the signal processing unit 210 includes a body movement noise reduction unit 212. Based on the body motion detection signal from the body motion sensor unit 170, the body motion noise reduction unit 212 performs a process of reducing (removing) body motion noise that is noise caused by body motion from the pulse wave detection signal. Specifically, for example, noise reduction processing using an adaptive filter or the like is performed.

  The pulsation information calculation unit 220 performs pulsation information calculation processing based on the signal from the signal processing unit 210 and the like. The pulsation information is information such as the pulse rate. Specifically, the pulsation information calculation unit 220 obtains a spectrum by performing frequency analysis processing such as FFT on the pulse wave detection signal after the noise reduction processing in the body motion noise reduction unit 212, and obtains the spectrum. In FIG. 5, processing is performed in which a representative frequency is a heartbeat frequency. A value obtained by multiplying the obtained frequency by 60 is a commonly used pulse rate (heart rate). Note that the pulsation information is not limited to the pulse rate itself, and may be other various information (for example, the frequency or cycle of the heartbeat) representing the pulse rate, for example. Moreover, the information which represents the state of pulsation may be sufficient, for example, it is good also considering the value showing the blood volume itself as pulsation information.

  The notification control unit 230 controls the notification unit 260. The notification unit 260 (notification device) notifies the user of various types of information under the control of the notification control unit 230. As the notification unit 260, for example, a notification light emitting unit can be used. In this case, the notification control unit 230 controls lighting, blinking, and the like of the light emitting unit by controlling the current flowing through the LED. Note that the notification unit 260 may be a display unit such as an LCD, a buzzer, or the like.

  The notification control unit 230 controls the vibration generation unit 180. The vibration generator 180 notifies the user of various types of information by vibration. The vibration generator 180 can be realized by a vibration motor (vibrator), for example. For example, the vibration motor generates vibration by rotating an eccentric weight. Specifically, eccentric weights are attached to both ends of the drive shaft (rotor shaft) so that the motor itself swings. The vibration of the vibration generator 180 is controlled by the notification controller 230. The vibration generator 180 is not limited to such a vibration motor, and various modifications can be made. For example, the vibration generating unit 180 may be realized by a piezo element or the like.

  For example, a start-up notification when the power is turned on, a notification of the success of the first pulse wave detection, a warning when a pulse wave cannot be detected continues for a certain period of time, a notification when the fat burning zone moves, In addition, a warning at the time of battery voltage drop, a notification of a wake-up alarm, or a notification such as an email or a phone call from a terminal device such as a smartphone can be performed. These pieces of information may be notified by a notification light emitting unit, or may be notified by both the vibration generating unit 180 and the light emitting unit.

  The communication unit 250 performs communication processing with the external terminal device 420 as described with reference to FIG. For example, a wireless communication process is performed according to a standard such as Bluetooth (registered trademark). Specifically, the communication unit 250 performs a signal reception process from the antenna 252 and a signal transmission process to the antenna 252. The function of the communication unit 250 can be realized by a logic circuit such as a communication processor or ASIC.

4.2 Configuration Example of Sensor Unit FIG. 14A shows a detailed configuration example of the sensor unit 40. The sensor unit 40 includes a light receiving unit 140 and a light emitting unit 150. The light receiving unit 140 and the light emitting unit 150 are mounted on a substrate 160 (sensor substrate). The light receiving unit 140 receives light (reflected light, transmitted light, etc.) from the subject. The light emitting unit 150 emits light to the subject. For example, when the light emitting unit 150 emits light to the subject and the light is reflected by the subject (blood vessel), the light receiving unit 140 receives and detects the reflected light. The light receiving unit 140 can be realized by a light receiving element such as a photodiode. The light emitting unit 150 can be realized by a light emitting element such as an LED. For example, the light receiving unit 140 can be realized by a PN junction diode element or the like formed on a semiconductor substrate. In this case, an angle limiting filter for narrowing the light receiving angle and a wavelength limiting filter for limiting the wavelength of light incident on the light receiving element may be formed on the diode element.

  Taking a pulse meter as an example, the light from the light emitting unit 150 travels inside the subject and diffuses or scatters in the epidermis, dermis, subcutaneous tissue, and the like. Thereafter, this light reaches the blood vessel (detected site) and is reflected. At this time, part of the light is absorbed by the blood vessels. Then, the light absorption rate in the blood vessel changes due to the influence of the pulse, and the amount of reflected light also changes. Therefore, the light receiving unit 140 receives this reflected light and detects the change in the amount of light, thereby detecting biological information. It becomes possible to detect the pulse rate and the like.

  A light shielding member 70 (light shielding wall 100) is provided between the light receiving unit 140 and the light emitting unit 150. For example, the light shielding member 70 shields light from the light emitting unit 150 from directly entering the light receiving unit 140.

  The sensor unit 40 is provided with a diaphragm unit 80 (80-1, 80-2). The diaphragm unit 80 squeezes light from the subject or light from the light emitting unit 150 in the optical path between the subject and the sensor unit 40. In FIG. 14A, the diaphragm unit 80 is provided between the translucent member 50 and the sensor unit 40. However, the aperture 80 may be provided between the translucent member 50 and the subject or in the translucent member 50. Further, the light shielding member 70 and the aperture 80 may be integrally formed by, for example, processing a metal sheet.

  The translucent member 50 is provided on the surface of the biological information detection apparatus that is in contact with the subject, and transmits light from the subject. The translucent member 50 contacts the subject when measuring the biological information of the subject. For example, the convex part 52 (detection window) of the translucent member 50 contacts the subject. The surface shape of the convex portion 52 is desirably a curved surface shape (spherical shape), but is not limited to this, and various shapes can be adopted. Moreover, the translucent member 50 should just be transparent with respect to the wavelength of the light from a subject, and may use a transparent material and may use a colored material.

  Around the convex portion 52 of the translucent member 50, a groove portion 54 is provided for suppressing pressure fluctuation and the like. Further, when the surface on the side where the convex portion 52 is provided in the translucent member 50 is the first surface, the translucent member 50 corresponds to the convex portion 52 on the second surface on the back side of the first surface. A recessed portion 56 is provided at a position to be used. In the space of the recess 56, a light receiving unit 140, a light emitting unit 150, a light blocking member 70, and a diaphragm unit 80 are provided.

  Further, on the surface on the subject side of the biological information detecting device, a pressure suppressing portion 58 that suppresses the pressure applied by the convex portion 52 to the subject (the wrist skin) is provided. In FIG. 14A, the pressing suppression portion 58 is provided so as to surround the convex portion 52 of the translucent member 50.

  In FIG. 14A, the height of the convex portion 52 in the direction orthogonal to the surface on the subject side of the biological information detecting device is HA (for example, the height of the apex of the curved surface shape of the convex portion 52), and pressure suppression is performed. When the height of the portion 58 is HB (for example, the height at the highest place) and the value obtained by subtracting the height HB from the height HA (difference between the heights HA and HB) is Δh, Δh = HA− The relationship of HB> 0 is established. For example, the convex part 52 protrudes from the pressing suppression part 58 to the subject side so that Δh> 0. That is, the convex portion 52 protrudes toward the subject side by Δh from the pressure suppression portion (pressure suppression surface) 58.

  Thus, by providing the convex part 52 that satisfies Δh> 0, for example, it is possible to apply an initial pressure to the subject to exceed the venous vanishing point, for example. In addition, by providing the pressure suppression unit 58 for suppressing the pressure applied to the subject by the convex portion 52, it is possible to minimize the pressure fluctuation in the usage range in which the biological information is measured by the biological information detection device. Therefore, noise components and the like can be reduced. Further, if the convex portion 52 protrudes from the pressing suppression portion 58 so as to satisfy Δh> 0, the pressing suppression portion 58 contacts the subject after the convex portion 52 contacts the subject and gives an initial pressure. Thus, the pressure applied to the subject by the convex portion 52 can be suppressed. Here, the vein vanishing point is reduced to such an extent that the signal caused by the vein superimposed on the pulse wave signal disappears or does not affect the pulse wave measurement when the convex portion 52 is brought into contact with the subject and the pressure is gradually increased. It is a point.

  For example, in FIG. 14B, the horizontal axis represents the load generated by the load mechanism (mechanism composed of a band part, a buckle part, etc.) of the biological information detection device, and the vertical axis represents the convex portion 52 covered. It represents the pressure applied to the specimen (pressure applied to the blood vessel). Then, it is assumed that the amount of change in the pressing of the convex portion 52 with respect to the load by the load mechanism that generates the pressing of the convex portion 52 is a pressing change amount. This amount of change in pressure corresponds to the inclination of the change characteristic of pressure against the load.

  In this case, the pressure suppression unit 58 has a second load range in which the load of the load mechanism is greater than FL1 with respect to the pressure change amount VF1 in the first load range RF1 in which the load of the load mechanism is 0 to FL1. The pressure applied to the subject by the convex portion 52 is suppressed so that the pressure change amount VF2 at RF2 is reduced. That is, in the first load range RF1 that is the initial pressing range, the pressing change amount VF1 is increased, while in the second load range RF2 that is the usage range of the biological information detecting device, the pressing change amount VF2 is decreased.

  That is, in the first load range RF1, the pressure change amount VF1 is increased to increase the inclination of the pressure change characteristic with respect to the load. Such a pressing with a large gradient of the change characteristic is realized by Δh corresponding to the protruding amount of the convex portion 52. That is, by providing the convex portion 52 that satisfies Δh> 0, even when the load by the load mechanism is small, it is possible to give the subject an initial pressure necessary and sufficient to exceed the venous vanishing point. become.

  On the other hand, in the second load range RF2, the pressure change amount VF2 is reduced to reduce the inclination of the pressure change characteristic with respect to the load. Such a pressing with a small inclination of the change characteristic is realized by pressing suppression by the pressing suppressing unit 58. In other words, the pressure suppression unit 58 suppresses the pressure applied to the subject by the convex portion 52, so that the variation in the pressure is minimized even when there is a load variation or the like in the usage range of the biological information detection device. It becomes possible to suppress. As a result, noise components can be reduced.

  In this way, it is possible to obtain a pulse wave detection signal having a higher M / N ratio (S / N ratio) by applying an optimized pressure (for example, about 16 kPa) to the subject. . That is, the signal component of the pulse wave sensor can be increased and the noise component can be reduced. Here, M represents the signal level of the pulse wave detection signal, and N represents the noise level.

  In addition, by setting the pressure range used for pulse wave measurement to a range corresponding to the second load range RF2, it is possible to suppress a minimum pressure fluctuation (for example, about ± 4 kPa), and a noise component Can be reduced.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. In addition, the configurations and operations of the light detection unit, the biological information detection device, and the like are not limited to those described in the present embodiment, and various modifications can be made.

10 band part, 12 band hole, 14 buckle part, 15 band insertion part,
16 Projection, 30 Case, 32 Light emitting window, 34 Top case, 35 Terminal,
36 bottom case, 40 sensor part, 50 translucent member, 52 convex part, 54 groove part,
56 concave portion, 58 pressure suppressing portion, 70 light shielding member, 71 metal surface, 72 metal surface,
73 metal surface, 74 metal surface, 75 metal surface, 80 aperture, 81 aperture,
100 light shielding wall, 140 light receiving part, 142 terminal, 150 light emitting part, 151 lens part,
153 Enclosing part, 155 pedestal part, 160 substrate, 162 terminal, 164 terminal,
168 lands, 169 holes, 170 body motion sensors, 172 acceleration sensors,
180 vibration generating unit, 200 processing unit, 210 signal processing unit,
212 body motion noise reduction unit, 220 pulsation information calculation unit, 230 notification control unit,
240 storage unit, 250 communication unit, 252 antenna, 260 notification unit,
400 biological information detection device, 410 wrist, 420 terminal device, 430 display unit

Claims (11)

A substrate,
A light emitting unit that emits light to an object;
A light receiving unit attached to the substrate and receiving light from the object;
Including
The substrate is provided with a hole,
The light detection unit, wherein the light emitting unit is attached to the hole of the substrate. In claim 1,
The light receiving unit is
Attached to the first side of the substrate;
The light emitting unit
The photodetecting unit, wherein the photodetecting unit is inserted into the hole from the second surface side of the substrate which is the back surface of the first surface. In claim 2,
The light emitting unit has a lens unit that collects light,
The light emitting unit
The light detection unit, wherein the lens portion is inserted into the hole so as to protrude toward the first surface. In claim 2 or 3,
The light emitting unit
A light emitting element;
An enclosing portion in which the light emitting element is encapsulated;
A pedestal part to be a pedestal of the enclosure part,
The pedestal is
The light detection unit is provided on the second surface side in a state where the light emitting unit is inserted into the hole. In claim 4,
The pedestal portion has a terminal electrically connected to the light emitting element,
The terminal is
A light detection unit, wherein the light detection unit is electrically connected to a wiring provided on the second surface of the substrate. In any one of Claims 1 thru | or 5,
The light detection unit, wherein the substrate is provided with a light shielding member that shields at least the light receiving portion. In claim 6,
The light shielding member has a light shielding wall that shields light from the light emitting part from being incident on the light receiving part,
The light detection unit according to claim 1, wherein h1 ≧ h2 when h1 is the height of the light shielding wall and h2 is the height of the light emitting portion. In claim 7,
When the height of the light receiving portion is h3, h1 ≧ h2> h3 is satisfied. In claim 7 or 8,
The light detection unit, wherein the light shielding member further includes a diaphragm portion. In claim 9,
The light shielding wall is formed by sheet metal processing,
The aperture unit is formed by the sheet metal processing or injection molding.   A biological information detection apparatus comprising the light detection unit according to claim 1.