Wearable device, method for detecting attachment / detachment of wearable device, and program

Abstract

To accurately detect when wearable devices are being attached or detached. [Solution] The CPU 11 of the wearable device 1 derives the tilt of the device 1 based on the acceleration detected by the acceleration sensor 162, and based on this tilt, determines at least one of the first light-emitting unit 1611, second light-emitting unit 1612, third light-emitting unit 1613, and fourth light-emitting unit 1614 (multiple light-emitting units) to emit light, and determines whether or not the device 1 is being worn by user U based on the light reception result of the light received by the light-receiving unit 1615 when light is emitted from the said light-emitting unit.

Description

Technical Field

[0001] The present invention relates to a wearable device, a method for detecting attachment / detachment of a wearable device, and a program.

Background Art

[0002] Conventionally, a blood pressure information measuring device that is worn on the arm of a subject and measures the blood pressure information of the subject has been disclosed (see Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the blood pressure information measuring device disclosed in Patent Document 1 above, it is possible to detect the pulse wave of the subject by a pulse wave detection unit having an optical sensor module including a light emitting unit and a light receiving unit. By the way, it is known that this optical sensor module is also used for detecting attachment / detachment of a wearable device on which the optical sensor module is mounted.

[0005] In the above optical sensor module, when the wearable device is removed from the user's body (for example, the arm), depending on the posture of the wearable device, the light emitted from the light emitting unit may be reflected by a desk or a band attached to the wearable device, and the reflected light may be received by the light receiving unit. As a result, in the above optical sensor module, there may be a case where it is erroneously detected that the user is wearing the wearable device even though the user is not wearing it.

[0006] The present invention has been made in view of such problems, and an object thereof is to accurately detect attachment / detachment of a wearable device. [Means for solving the problem]

[0007] To solve the above problems, the wearable device according to the present invention is a wearable device worn by a user, comprising a plurality of light-emitting units, a light-receiving unit, a tilt acquisition unit, and a control unit, wherein the control unit determines at least one of the plurality of light-emitting units to emit light based on the tilt of the device acquired by the tilt acquisition unit, and determines whether or not the device is being worn by the user based on the light reception result of the light received by the light-receiving unit when light is emitted from the light-emitting unit. [Effects of the Invention]

[0008] According to the present invention, the attachment and detachment of wearable devices can be detected with high accuracy. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the external configuration of the wearable device according to this embodiment. [Figure 2] This is a block diagram showing the functional configuration of wearable devices. [Figure 3] This is a diagram showing the back of the main unit. [Figure 4] This is a flowchart showing the attachment / detachment detection and control process. [Figure 5] Figures (a) to (f) show the method for determining the light-emitting part that emits light. [Figure 6] Figures (a) to (d) show the method for determining the light-emitting part that emits light. [Figure 7] Figures (a) to (f) show the method for determining the light-emitting part that emits light. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. While the embodiments described below are subject to various technically preferred limitations for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples. First, the external configuration of the wearable device 1 of this embodiment will be described with reference to Figure 1. As shown in Figure 1, the wearable device 1 is, for example, a wristwatch, smartwatch, or activity tracker, and comprises a main body 2 and a band 3. The band 3 is for attaching the wearable device 1 to the arm of user U and comprises a main band 3a and a tip band 3b.

[0011] Next, the functional configuration of the wearable device 1 (main unit 2) will be described with reference to Figure 2. As shown in Figure 2, the wearable device 1 comprises a CPU (Central Processing Unit) 11, RAM (Random Access Memory) 12, a storage unit 13, an operation reception unit 14, a display unit 15, and a sensor unit 16. Each part of the wearable device 1 is connected via a bus 17.

[0012] The CPU (control unit) 11 is a hardware processor that performs arithmetic processing and provides overall control over the operation of the wearable device 1. The CPU 11 may be a single processor, or multiple processors may operate in parallel. Alternatively, multiple independent processors may operate separately for each defined purpose. The CPU 11 may also perform calculations such as counting the current date and time and display the current time and date on the display screen of the display unit 15. The RAM 12 provides the CPU 11 with a working memory space and stores temporary data. The storage unit 13 is a non-volatile memory (for example, flash memory). The storage unit 13 stores the program 131 and setting data. The program 131 includes a control program related to the attachment / detachment detection operation control processing (see Figure 4) described later.

[0013] The operation reception unit 14 (see Figures 1 and 3) receives input operations from an external source, such as a user U, generates an input signal, and outputs the input signal to the CPU 11. The operation reception unit 14 has, for example, a push-button switch. In addition to or instead of this, the operation reception unit 14 may have other operation reception members, such as a touch panel positioned over the display screen of the display unit 15. The display unit 15 (see Figure 1) displays information on the display screen in accordance with the control of the CPU 11. The display screen is, for example, a liquid crystal display (LCD), but is not limited to this. The display screen may display numbers, characters, signs, graphics, images, etc., within a range corresponding to its resolution.

[0014] The sensor unit 16 includes an attachment / detachment detection sensor 161, an acceleration sensor 162, and the like. The sensor unit 16 may also have sensors not shown in Figure 2. The attachment / detachment detection sensor 161 measures whether or not the wearable device 1 is attached to the user U's arm and outputs the measurement result to the CPU 11. The attachment / detachment detection sensor 161 includes a first light-emitting unit 1611, a second light-emitting unit 1612, a third light-emitting unit 1613, a fourth light-emitting unit 1614, and a light-receiving unit 1615. The first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 are all infrared LEDs (Light Emitting Diodes). The light-receiving unit 1615 is a photodiode that detects light emitted from the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, or the fourth light-emitting unit 1614, and converts this light into an electrical signal by the photoelectric effect.

[0015] As shown in Figure 3, the light-receiving unit 1615 is positioned in the center of the back surface of the main body 2, that is, in the center of the surface facing the user U's arm when the wearable device 1 is worn. The first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 are each arranged at equal intervals radially around the light-receiving unit 1615 on the back surface of the main body 2. Specifically, the first light-emitting unit 1611 is positioned at the 12 o'clock position on an analog clock with the light-receiving unit 1615 as the center. The second light-emitting unit 1612 is positioned at the 3 o'clock position on an analog clock with the light-receiving unit 1615 as the center. The third light-emitting unit 1613 is positioned at the 6 o'clock position on an analog clock with the light-receiving unit 1615 as the center. The fourth light-emitting section 1614 is positioned at the 9 o'clock position on an analog clock, with the light-receiving section 1615 at its center. In other words, the first light-emitting section 1611, the second light-emitting section 1612, the third light-emitting section 1613, and the fourth light-emitting section 1614 are positioned at predetermined locations in the longitudinal direction of the band 3 and in directions perpendicular to the longitudinal direction.

[0016] Here, we will explain the principle of attachment / detachment detection. The attachment / detachment detection sensor 161 emits light (infrared light) from the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, or the fourth light-emitting unit 1614, and the light-receiving unit 1615 detects the light that is reflected back from the object (user U's arm). At this time, the amount of light detected by the light-receiving unit 1615 is converted into an electrical signal, and the presence or absence of the object (whether it is attached or detached) is determined by the magnitude of this electrical signal. The attachment / detachment detection sensor 161 measures the magnitude of the electrical signal as described above, that is, it measures whether or not the wearable device 1 is attached to user U's arm, and outputs the measurement result (light-receiving result) to the CPU 11.

[0017] Returning to Figure 2, the acceleration sensor 162 (tilt acquisition unit) detects the acceleration of the wearable device 1 in the orthogonal three-axis direction and outputs the detection result to the CPU 11. From the detection result by the acceleration sensor 162, the angles in the orthogonal three-axis direction (roll angle, pitch angle, yaw angle) representing the tilt of the wearable device 1 can be detected.

[0018] Next, referring to FIG. 4, the attachment / detachment detection operation control process executed by the wearable device 1 will be described. The attachment / detachment detection operation control process is executed by the CPU 11 in cooperation with a control program related to the attachment / detachment detection operation control process read from the storage unit 13 and appropriately expanded in the RAM 12. Here, the attachment / detachment detection operation control process is continuously executed, for example,契机として when the wearable device 1 is activated. Also, the acceleration sensor 162 is turned on when the wearable device 1 is activated. The end of the attachment / detachment detection operation control process may be made by an interrupt process when the operation reception unit 14 receives a predetermined operation or when the operation of the wearable device 1 is turned off.

[0019] As shown in FIG. 4, first, the CPU 11 of the wearable device 1 acquires the detection result of the acceleration detected by the acceleration sensor 162 from the acceleration sensor 162 (step S1). Next, the CPU 11 derives the inclination (posture) of the wearable device 1 based on the detection result of the acceleration acquired in step S1 (step S2). Next, the CPU 11 determines, based on the inclination (posture) of the wearable device 1 derived in step S2, the light-emitting unit existing at the highest position (the highest side in the up-down direction (vertical direction)) among the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 as the light-emitting unit to irradiate light (step S3).

[0020] Specifically, as shown in Figure 5(a), when the wearable device 1 is placed on a desk or the like with the main band 3a positioned towards the top and the tip band 3b towards the bottom, as shown in Figure 5(b), the first light-emitting part 1611 is the highest-positioned light-emitting part (the highest point in the vertical direction) among the first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614. Therefore, the first light-emitting part 1611 is determined to be the light-emitting part that emits light. Furthermore, as shown in Figure 5(c), when the wearable device 1 is placed on a desk or the like with the longitudinal direction of the band 3 perpendicular to the vertical direction and the operation reception unit 14 provided on the main body 2 located on the ground side in the vertical direction, as shown in Figure 5(d), the second light-emitting unit 1612 is the highest-positioned light-emitting unit among the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614. Therefore, the second light-emitting unit 1612 is determined to be the light-emitting unit that emits light. Furthermore, as shown in Figure 5(e), when the wearable device 1 is placed on a desk or the like with the tip band 3b positioned on the top side in the vertical direction and the main band 3a positioned on the bottom side, as shown in Figure 5(f), the third light-emitting part 1613 is the highest-positioned light-emitting part among the first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614. Therefore, the third light-emitting part 1613 is determined to be the light-emitting part that emits light. Furthermore, as shown in Figure 6(a), when the wearable device 1 is placed on a desk or the like with the longitudinal direction of the band 3 perpendicular to the vertical direction and the operation reception unit 14 provided on the main body 2 located on the upper side in the vertical direction, as shown in Figure 6(b), the fourth light-emitting unit 1614 is the highest-positioned light-emitting unit among the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614. Therefore, the fourth light-emitting unit 1614 is determined to be the light-emitting unit that emits light. Furthermore, as shown in Figure 6(c), when the wearable device 1 is placed on a desk or the like with the longitudinal direction of the band 3 perpendicular to the vertical direction and the display screen of the display unit 15 provided on the main body 2 facing upwards in the vertical direction, the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 are all at the same height relative to each other in the vertical direction.In such a case, the predetermined second light-emitting unit 1612 is determined as the light-emitting unit that irradiates light. In this case, the light-emitting unit that irradiates light only needs to be able to reduce the reflection value in band 3 of the light irradiated from the light-emitting unit for the purpose of suppressing false detection in which the user U is determined to be wearing the wearable device 1 despite not wearing it. Therefore, in such a case, the fourth light-emitting unit 1614 located at a position far from band 3 compared to the first light-emitting unit 1611 and the third light-emitting unit 1613 may be determined as the light-emitting unit that irradiates light.

[0021] Furthermore, as shown in Figure 7(a), when the wearable device 1 is attached to the arm of user U, with the main band 3a positioned on the upper side in the vertical direction and the tip band 3b positioned on the lower side, as shown in Figure 7(b), the first light-emitting part 1611 is the highest-positioned light-emitting part (the highest point in the vertical direction) among the first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614. Therefore, the first light-emitting part 1611 is determined to be the light-emitting part that emits light. In this case, due to the movement of user U's forearm bones (radius and ulna), the little finger side of the wrist is more likely to come into close contact with the main body 2 than the thumb side. For this reason, in this case, by determining the first light-emitting part 1611, which is located in a position that is more likely to come into close contact with user U's arm, as the light-emitting part that emits light, it is possible to prevent a reduction in the reflection value of the light emitted from the light-emitting part on user U's arm. Furthermore, as shown in Figure 7(c), when the wearable device 1 is attached to the arm of user U, with the tip band 3b positioned on the upper side in the vertical direction and the main band 3a positioned on the lower side, as shown in Figure 7(d), the third light-emitting part 1613 is the highest-positioned light-emitting part among the first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614. Therefore, the third light-emitting part 1613 is determined to be the light-emitting part that emits light. In this case, due to the movement of user U's forearm bones (radius and ulna), the thumb side of the wrist is more likely to come into close contact with the main body 2 than the little finger side. For this reason, in this case, by determining the third light-emitting part 1613, which is located in a position that is more likely to come into close contact with user U's arm, as the light-emitting part that emits light, it is possible to prevent a reduction in the reflection value of the light emitted from the light-emitting part on user U's arm. Furthermore, as shown in Figure 7(e), when the wearable device 1 is attached to the arm of user U, and the display screen of the display unit 15 on the main body 2 is positioned to face upwards in the vertical direction, the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 are all at the same height relative to each other in the vertical direction. In such a case, the predetermined second light-emitting unit 1612 is determined to be the light-emitting unit that emits light.In such cases, the light-emitting unit that emits light should be designed so as not to reduce the reflectance value of the light emitted from the unit on the user U's arm, in order to suppress false detections where the wearable device 1 is being judged as not being worn even though the user U is wearing it. Therefore, in such cases, the fourth light-emitting unit 1614, which is more likely to be in close contact with the user U's arm than the first light-emitting unit 1611 and the third light-emitting unit 1613, may be selected as the light-emitting unit that emits light.

[0022] Returning to Figure 4, the CPU 11 then starts irradiating light from the light-emitting unit determined in step S3 (step S4). The light-emitting unit determined in step S3 is one of the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, or the fourth light-emitting unit 1614, as described above. Next, the CPU 11 acquires the measurement result (receiving result) related to the magnitude of the electrical signal measured by the light-receiving unit 1615 (step S5). This electrical signal is a conversion of the amount of light detected by the light-receiving unit 1615, as described above. This amount of light is the amount of light irradiated from the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, or the fourth light-emitting unit 1614 and reflected back from an object (for example, the arm of user U). Next, the CPU 11 terminates the irradiation of light from the light-emitting unit determined in step S3 (step S6). Next, the CPU 11 determines whether or not the wearable device 1 is attached to the user U's arm (attachment / detachment determination) based on the measurement results obtained in step S6 (step S7). Specifically, if the magnitude of the electrical signal indicated by the measurement results is above a predetermined threshold, the CPU 11 determines that the wearable device 1 is attached to the user U's arm. On the other hand, if the magnitude of the electrical signal indicated by the measurement results is below the predetermined threshold, the CPU 11 determines that the wearable device 1 is not attached to the user U's arm. Then, the CPU 11 returns to step S1 and repeats the subsequent processing.

[0023] As described above, the CPU 11 of the wearable device 1 derives the tilt of the device 1 based on the acceleration detected by the acceleration sensor 162, and based on this tilt, determines at least one light-emitting unit from the first light-emitting unit 1611, second light-emitting unit 1612, third light-emitting unit 1613, and fourth light-emitting unit 1614 (multiple light-emitting units) to emit light, and determines whether or not the device 1 is being worn by user U based on the light reception result of the light received by the light-receiving unit 1615 when light is emitted from that light-emitting unit. Therefore, with the wearable device 1, when not being worn (see Figures 5 and 6), by emitting light from a light-emitting unit located as far away as possible from reflective objects such as the band 3 or the desk on which the device 1 is placed, the reflection value of the light emitted from that light-emitting unit at the reflective object can be reduced. As a result, false detections in which user U is judged to be wearing the wearable device 1 when they are not can be suppressed, and the attachment and detachment detection of the wearable device 1 can be performed with high accuracy. Furthermore, with wearable device 1, by emitting light from a light-emitting part located in a position that is likely to be in close contact with user U's arm when worn (see Figure 7), it is possible to prevent a reduction in the reflected value of the light emitted from the light-emitting part on user U's arm. As a result, false detections in which user U is wearing wearable device 1 but is judged not to be wearing it can be suppressed, and the wearing and removal of wearable device 1 can be detected with high accuracy.

[0024] Furthermore, based on the tilt of the wearable device 1, the CPU 11 determines which of the first light-emitting part 1611, second light-emitting part 1612, third light-emitting part 1613, and fourth light-emitting part 1614 is located at the highest position and will emit light. Therefore, with the wearable device 1, when not being worn, the light-emitting part located as far away as possible from reflective objects such as the band 3 or the desk on which the device 1 is placed can be determined as the light-emitting part to emit light. As a result, the attachment and detachment of the wearable device 1 can be detected with high accuracy. Also, with the wearable device 1, when being worn, the light-emitting part located in a position that is likely to be in close contact with the user U's arm can be determined as the light-emitting part to emit light. As a result, the attachment and detachment of the wearable device 1 can be detected with high accuracy.

[0025] Furthermore, the first light-emitting unit 1611, the second light-emitting unit 1612, the third light-emitting unit 1613, and the fourth light-emitting unit 1614 are each arranged radially at equal intervals on the back surface of the main body 2, with the light-receiving unit 1615 at the center. Therefore, with the wearable device 1, it is possible to smoothly determine which light-emitting unit will emit light, that is, which light-emitting unit is located at the highest position.

[0026] Furthermore, the wearable device 1 includes a band 3 for attaching the device 1 to the user U's arm. The first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614 are arranged at predetermined positions in the longitudinal direction of the band 3 and in directions perpendicular to the longitudinal direction. Therefore, with the wearable device 1, the arrangement of the first light-emitting part 1611, the second light-emitting part 1612, the third light-emitting part 1613, and the fourth light-emitting part 1614 makes it less likely that there will be two light-emitting parts located at the highest position, thus making it easier to determine which light-emitting part should emit light.

[0027] The above description of the embodiment is merely an example of the wearable device, the method for detecting attachment and detachment of the wearable device, and the program according to the present invention, and is not limited thereto. For example, in the above embodiment, one light-emitting unit may be positioned in the center of the back surface of the main body 2, that is, in the center of the surface facing the user U's arm when the wearable device 1 is worn, and the first light-receiving unit, the second light-receiving unit, the third light-receiving unit, and the fourth light-receiving unit may each be positioned at equal intervals radially around the light-emitting unit on the back surface of the main body 2. Specifically, the first light-receiving unit is positioned at the 12 o'clock position on an analog clock with the light-emitting unit as the center. The second light-receiving unit is positioned at the 3 o'clock position on an analog clock with the light-emitting unit as the center. The third light-receiving unit is positioned at the 6 o'clock position on an analog clock with the light-emitting unit as the center. The fourth light-receiving unit is positioned at the 9 o'clock position on an analog clock with the light-emitting unit as the center. In other words, the first, second, third, and fourth light-receiving units are arranged at predetermined positions in the longitudinal direction of the band 3 and in a direction perpendicular to the longitudinal direction. In this case, the CPU 11 of the wearable device 1 derives the tilt of the device 1 based on the acceleration detected by the acceleration sensor 162, and based on this tilt, determines at least one of the first, second, third, and fourth light-receiving units to receive light emitted from the light-emitting unit, and determines whether or not the device 1 is being worn by the user U based on the light reception result of the light received by that light-receiving unit.

[0028] Furthermore, in the above embodiment, an acceleration sensor 162 is used as the tilt acquisition unit according to the present invention, but other sensors may be used as the tilt acquisition unit as long as they can acquire the tilt of the wearable device 1.

[0029] Furthermore, in the above embodiment, the attachment / detachment detection sensor 161 may be used not only to detect the attachment or detachment of the wearable device 1, but also, for example, as a pulse wave sensor to measure the pulse wave of user U.

[0030] Furthermore, while the above description discloses an example in which the flash memory of the storage unit 13 is used as a computer-readable medium for the program according to the present invention, the invention is not limited to this example. Other computer-readable mediums that can be used include information recording media such as HDDs (Hard Disk Drives), SSDs (Solid State Drives), and CD-ROMs. In addition, a carrier wave can also be used as a medium for providing the program data according to the present invention via a communication line.

[0031] Furthermore, it goes without saying that the detailed configuration and operation of each component of the wearable device 1 in the above embodiment can be appropriately modified without departing from the spirit of the present invention. [Explanation of Symbols]

[0032] 1 Wearable device, 11 CPU (control unit), 161 Attachment / detachment detection sensor, 1611 First light-emitting unit, 1612 Second light-emitting unit, 1613 Third light-emitting unit, 1614 Fourth light-emitting unit, 1615 Light-receiving unit, 162 Acceleration sensor (tilt acquisition unit)

Claims

1. A wearable device worn by the user, It comprises multiple light-emitting units, a light-receiving unit, a tilt acquisition unit, and a control unit. The control unit, Based on the tilt of the device acquired by the tilt acquisition unit, at least one of the plurality of light-emitting units to emit light is determined. When light is emitted from the light-emitting unit, the device determines whether or not it is attached to the user based on the light reception result of the light received by the light-receiving unit. A wearable device characterized by the following:

2. The aforementioned tilt acquisition unit is an acceleration sensor, The control unit, The tilt of the device is derived based on the acceleration detected by the aforementioned acceleration sensor. The wearable device according to feature 1.

3. The control unit, Based on the aforementioned inclination, the light-emitting part located at the highest position among the plurality of light-emitting parts is determined to be the light-emitting part that emits light. The wearable device according to feature 1.

4. Each of the plurality of light-emitting units is The light receiving section is arranged radially at equal intervals, The wearable device according to feature 1.

5. The device is equipped with a band for attaching it to the user's arm, The aforementioned plurality of light-emitting units are composed of four light-emitting units. The four light-emitting parts are, The band is provided with predetermined positions in the longitudinal direction and in the direction perpendicular to the longitudinal direction, The wearable device according to feature 4.

6. A wearable device worn by a user, comprising a plurality of light-emitting units, a light-receiving unit, and a tilt acquisition unit, wherein a method for detecting the attachment or detachment of the wearable device is performed by the computer of the wearable device, A determination step of determining at least one of the plurality of light-emitting units to emit light based on the tilt of the device obtained by the tilt acquisition unit, A determination step is to determine whether or not the device is attached to the user based on the light reception result of the light received by the light receiving unit when light is irradiated from the light-emitting unit, A method for detecting the attachment or detachment of a wearable device, characterized by including the following:

7. A wearable device worn by a user, comprising a computer for the wearable device having multiple light-emitting units, a light-receiving unit, and a tilt acquisition unit, A determination means that determines at least one of the plurality of light-emitting units to emit light based on the tilt of the device obtained by the tilt acquisition unit, A determination means for determining whether or not the device is attached to the user, based on the light reception result of the light received by the light receiving unit when light is irradiated from the light-emitting unit. A program characterized by being designed to function as such.

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