Electronic devices, methods for controlling electronic devices, and computer-readable recording media

Abstract

The electronic device worn by the user includes: a light-emitting part that emits light to the user's skin; a light-receiving part that is positioned to receive light reflected from the user's skin when the device is worn by the user and when the light-emitting part emits light; and a control unit that performs a skin determination based on the amount of light received by the light-receiving part to determine whether the user's skin meets a predetermined darkness condition, and performs a wearing determination based at least on the amount of light received by the light-receiving part to determine whether the device is worn by the user. If the skin determination determines that the darkness condition is met, the wearing determination is not performed.

Description

Technical Field

[0001] This invention relates to electronic devices, control methods for electronic devices, and computer-readable recording media containing programs. Background Technology

[0002] Previously, it was known that in electronic devices worn by a user, a light-receiving part receives reflected light from the user's skin and detects the pulse based on changes in the amount of light received (e.g., Patent Document 1). Additionally, it was known that when the user is not wearing the electronic device, the amount of light received by the light-receiving part decreases, and the user determines whether the device is being worn based on the amount of light received.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 4476664 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, when an electronic device is worn by a user, the amount of light reflected from the user's skin and incident on the light-receiving part (i.e., the amount of light received by the light-receiving part) is less when the skin is darker. Therefore, there is a problem: depending on the darkness of the user's skin, even if the user is wearing an electronic device, it may be mistakenly judged as not being worn due to the reduced amount of light received.

[0008] The purpose of this invention is to provide an electronic device for appropriately determining the wearing status, a control method for the electronic device, and a program.

[0009] Methods for solving problems

[0010] To address the aforementioned issues, the electronic device of the present invention is a user-worn electronic device comprising: a light-emitting unit that emits light toward the user's skin; a light-receiving unit disposed at a position capable of receiving light reflected from the user's skin when the device is worn by the user and when the light-emitting unit emits the light; and a control unit that performs a skin determination based on the amount of light received by the light-receiving unit to determine whether the user's skin meets a predetermined darkness condition, and performs a wearing determination based at least on the amount of light received by the light-receiving unit to determine whether the device is worn by the user, wherein if the skin determination determines that the darkness condition is met, the wearing determination is not performed.

[0011] To address the aforementioned problems, the present invention provides a control method for an electronic device worn by a user. The electronic device includes: a light-emitting portion that emits light to the user's skin; and a light-receiving portion disposed at a position capable of receiving light reflected from the user's skin when the device is worn by the user and when the light-emitting portion emits the light. The control method comprises: a skin determination step that determines whether the user's skin meets a predetermined darkness condition based on the amount of light received by the light-receiving portion; and a wearing determination step that determines whether the device is worn by the user, at least based on the amount of light received by the light-receiving portion. If the skin determination determines that the darkness condition is met, the wearing determination step is not performed.

[0012] To address the aforementioned issues, the present invention provides a program executed by a computer installed in an electronic device worn by a user. The electronic device includes: a light-emitting unit that emits light to the user's skin; and a light-receiving unit disposed at a position capable of receiving light reflected from the user's skin when the device is worn by the user and when the light-emitting unit emits the light. The program enables the computer to function as a control unit, which performs a skin determination based on the amount of light received by the light-receiving unit to determine whether the user's skin meets a predetermined darkness condition, and at least performs a wearing determination based on the amount of light received by the light-receiving unit to determine whether the device is worn by the user. If the skin determination determines that the darkness condition is met, the wearing determination is not performed.

[0013] Invention Effects

[0014] According to the present invention, the wearing status can be appropriately determined. Attached Figure Description

[0015] Figure 1 It is a three-dimensional diagram showing the appearance of the electronic watch.

[0016] Figure 2 This is a side view of a digital watch.

[0017] Figure 3 It is a block diagram representing the functional structure of a digital watch.

[0018] Figure 4A This is a diagram illustrating an example of the difference in light received due to the darkness of the skin.

[0019] Figure 4B This is a diagram illustrating an example of the difference in light received due to the darkness of the skin.

[0020] Figure 5 This is a flowchart representing the control steps of pulse rate measurement and processing.

[0021] Figure 6 This is a flowchart representing the control steps that initiate the pulse rate measurement process.

[0022] Figure 7 This is a flowchart illustrating the control steps of skin assessment and treatment.

[0023] Figure 8 This is a flowchart representing the control steps of the wearing determination process.

[0024] Figure 9 This is a flowchart indicating the control steps for restarting pulse rate measurement. Detailed Implementation

[0025] Hereinafter, embodiments of the electronic device, the control method of the electronic device, and the program of the present invention will be described with reference to the accompanying drawings.

[0026] (Structure of a digital watch)

[0027] Figure 1 This is a three-dimensional view showing the appearance of electronic watch 1.

[0028] Electronic watch 1 (electronic device) is a watch worn on a user's wrist. Electronic watch 1 has a main body 2 with a display screen 121 and operation buttons 131, and a watch strap 3 attached to the main body 2. The display screen 121 displays numbers in a dot matrix format. In addition to basic information such as time and date, electronic watch 1 displays the user's pulse rate (heart rate) measurement results on the display screen 121.

[0029] Figure 2 This is a side view of electronic watch 1.

[0030] The electronic watch 1 has a light-emitting part 15 and a light-receiving part 17 for detecting pulse inside the main body 2. The light-emitting part 15 and the light-receiving part 17 are located on the back of the main body 2, near the surface that contacts the user's wrist when worn. The light-emitting part 15 emits light from the back of the main body 2 outwards. When the user wears the electronic watch 1, the light emitted from the light-emitting part 15 is reflected by the user's skin. The light-receiving part 17 is positioned to receive the light reflected from the user's skin. A portion of the light that shines on the user's skin is absorbed by the blood in the blood vessels. Therefore, the amount of light received by the light-receiving part 17 from the skin changes over time according to the change in blood flow accompanying the heartbeat. The pulse is detected based on this change in the amount of light received, and the pulse rate is measured based on the detected pulse.

[0031] Figure 3 This is a block diagram representing the functional structure of electronic watch 1.

[0032] The electronic watch 1 includes a CPU 10 (Central Processing Unit), a memory 11 (storage unit), a display unit 12, an operation receiving unit 13, an oscillation circuit 141, a frequency division circuit 142, a timing circuit 143, a light-emitting unit 15, a light-emitting driving unit 16, a light-receiving unit 17, an acceleration sensor 18, and an A / D converter 19.

[0033] CPU 10 is a processor that performs various calculations and controls the operation of each part of the electronic watch 1. CPU 10 functions as a control unit (control unit) to perform various control actions by reading and executing the program 111 stored in memory 11.

[0034] For example, the CPU 10 causes the display unit 12 to display the date and time counted by the timing circuit 143. Additionally, the CPU 10 detects the pulse based on changes in the amount of light received by the light-receiving unit 17, and displays the measurement result of the pulse rate (pulse count per minute) on the display unit 12. Furthermore, the CPU 10 performs a skin determination based on the amount of light received by the light-receiving unit 17 to determine whether the user's skin meets a predetermined darkness condition. Additionally, the CPU 10 performs a wearing determination based on the amount of light received by the light-receiving unit 17 and the acceleration detection result from the accelerometer 18 to determine whether the electronic watch 1 (this device) is being worn by the user. Skin determination and wearing determination will be described in detail later.

[0035] The memory 11 provides storage space for the CPU 10 to perform operations and stores various types of data. The memory 11 includes, for example, RAM (Random Access Memory) and non-volatile memory. RAM is used for the CPU 10's arithmetic processing and also stores temporary data. Non-volatile memory is a non-temporary recording medium that can be read by the CPU 10, which is a computer. Non-volatile memory is, for example, flash memory, and stores various types of data in addition to the program 111. The program 111 includes, in addition to the control program for controlling the basic operations of the electronic watch 1, an application program for measuring the pulse rate and displaying the result on the display unit 12 (hereinafter referred to as "pulse rate measurement application"). As data stored in the memory 11, there is a wearing determination execution flag 112. The wearing determination execution flag 112 is used to determine whether to execute the wearing determination process described later. The wearing determination execution flag 112 is, for example, a 1-bit data.

[0036] The display unit 12 includes a display screen 121, on which digital displays are performed under the control of the CPU 10. Here, the display screen 121 can display in a dot-matrix format, such as a liquid crystal display screen.

[0037] The operation receiving unit 13 has multiple operation buttons 131. The operation receiving unit 13 accepts user input operations (e.g., pressing) on ​​the operation buttons 131 and outputs them as input signals to the CPU 10. The CPU 10 performs processing corresponding to the function of the operation button 131 that has received the input operation. The functions assigned to each operation button 131 can also be switched according to the operating mode of the electronic watch 1. The operation buttons 131 may also include a crown. Additionally, the operation receiving unit 13 may also have a touch panel that overlaps with the display screen 121.

[0038] The oscillation circuit 141 generates a clock signal with a predetermined oscillation frequency and outputs it to the frequency divider circuit 142. The frequency divider circuit 142 divides the clock signal input from the oscillation circuit 141, converting it into the frequency required for the operation of each part of the electronic watch 1, and outputs it. The output destination of the frequency-divided signal by the frequency divider circuit 142 includes the timing circuit 143.

[0039] The timing circuit 143 counts the signal of a predetermined frequency input from the frequency divider circuit 142, counts the current date and time, and holds it. The format of the date and time held by the timing circuit 143 is not limited to a format expressed in year, month, day, hour, minute, and second, but can also be a suitable format for processing by the CPU 10, etc.

[0040] The light-emitting unit 15 includes a light-emitting element such as an LED (Light Emitting Diode). In this embodiment, the light-emitting unit 15 includes an LED that emits green light, which is easily absorbed by hemoglobin in the blood, for example, light with a peak wavelength of 520nm to 530nm. The LED of the light-emitting unit 15 emits light according to a driving current supplied from the light-emitting driving unit 16.

[0041] The light-emitting drive unit 16 controls the output of the drive current to the light-emitting unit 15 according to the control signal from the CPU 10, thereby causing the LED of the light-emitting unit 15 to light up or turn off.

[0042] The light-receiving unit 17 includes a light-receiving element that detects light and outputs an electrical signal corresponding to the amount of light received. Here, the amount of light received is, for example, the intensity of the incident light. As the light-receiving element, a photodiode or an illuminance sensor can be used, for example.

[0043] Accelerometer 18 detects the acceleration of electronic watch 1 caused by user actions, etc., and outputs an electrical signal corresponding to the acceleration. Accelerometer 18 detects, for example, the acceleration in each of the three axes of an orthogonal coordinate system.

[0044] The A / D converter 19 converts the electrical signals output from the light-receiving unit 17 and the accelerometer 18 into digital data and outputs them to the CPU 10. Therefore, digital data representing the amount of light received by the light-receiving unit 17 is output from the A / D converter 19 to the CPU 10. Additionally, the A / D converter 19 outputs digital data representing the detection result of the acceleration of the accelerometer 18 to the CPU 10. The A / D converter 19 can also be provided separately for the light-receiving unit 17 and the accelerometer 18.

[0045] (The operation of the digital watch)

[0046] Next, the operation of the electronic watch 1 will be explained, focusing on the actions related to pulse rate measurement.

[0047] As described above, the measurement of pulse rate in the electronic watch 1 (and therefore, the detection of pulse) is accompanied by the illumination of the LED of the light-emitting unit 15 (hereinafter referred to as the illumination of the light-emitting unit 15). Therefore, when the electronic watch 1 is removed from the user's wrist during pulse rate measurement, it is preferable to turn off the light-emitting unit 15 and stop the pulse rate measurement from both an aesthetic and power consumption perspective.

[0048] Therefore, in the electronic watch 1 of this embodiment, after starting the pulse rate measurement, a wearing determination is performed to determine whether the device is being worn by the user. This wearing determination is based on whether the amount of light received from the light-receiving unit 17 is greater than a predetermined reference value ( Figure 4A and Figure 4B The second reference value V2 is used. When the electronic watch 1 is worn on the user's wrist, the light emitted from the light-emitting part 15 is reflected off the skin and enters the light-receiving part 17. On the other hand, when the electronic watch 1 is removed from the user's wrist, the light emitted from the light-emitting part 15 diffuses off the skin without reflection and therefore hardly returns to the light-receiving part 17. Therefore, when the electronic watch 1 is not worn by the user, the amount of light received by the light-receiving part 17 is significantly reduced compared to when it is worn. Therefore, it is possible to determine whether the electronic watch 1 is worn by the user based on whether the amount of light received by the light-receiving part 17 is greater than the second reference value V2. The second reference value V2 is set as the value between the amount of light received when the electronic watch 1 is worn by the user and the amount of light received when the electronic watch 1 is not worn by the user. When it is determined that the electronic watch 1 is not worn by the user, the pulse rate measurement is stopped.

[0049] However, the darker the skin (e.g., the more intense the skin color), the smaller the proportion of light emitted from the light-emitting part 15 that is reflected by the user's skin and incident on the light-receiving part 17. Therefore, the amount of light received by the light-receiving part 17 varies greatly depending on the darkness of the user's skin. Thus, depending on the darkness of the skin, even if the electronic watch 1 is being worn by the user, it may sometimes be mistakenly judged as not being worn due to the reduced amount of light received. When such a misjudgment occurs, the pulse rate measurement is stopped at an undesirable moment during the wearing of the electronic watch 1. Here, the darkness of the skin includes not only the darkness caused by the skin color, but also the darkness caused by changes in light reflectivity and diffusion state due to cosmetics or other substances applied to the skin.

[0050] Figure 4A as well as Figure 4B This is a diagram illustrating an example of the difference in light received due to the darkness of the skin.

[0051] Figure 4A This example illustrates the amount of light received by the light-receiving part 17 when a user with bright skin uses the electronic watch 1. Figure 4B This example illustrates the amount of light received by the light-receiving section 17 when a user with dark skin uses the electronic watch 1. In detail, Figure 4A This indicates that users with skin classified as Type I in Fitzpatrick used Table 1. On the other hand, Figure 4B This indicates that a user whose skin is classified as type VI in Fitzpatrick's skin types used Table 1.

[0052] exist Figure 4A and Figure 4B During the period from time t0 to time t1, the user wears electronic watch 1. Furthermore, at time t1, electronic watch 1 is removed from the user's wrist, and at time t2, electronic watch 1 is placed on the table.

[0053] In such a situation, such as Figure 4A As shown, under bright skin conditions, the amount of light received while wearing the watch (time t0-t1) is greater than the second reference value V2, therefore an appropriate determination is made indicating that the watch is being worn. Furthermore, when the watch is removed and left idle (after time t2), the amount of light received is less than the second reference value V2, therefore an appropriate determination is made indicating that the watch is not being worn.

[0054] On the other hand, such as Figure 4B As shown, in the case of dark skin, even when worn (time t0~t1), the amount of light received is below the second reference value V2. Therefore, even if the user is wearing the electronic watch 1, an inappropriate judgment will be made indicating that the watch is not being worn.

[0055] Therefore, in the electronic watch 1 of this embodiment, a skin determination is performed based on the amount of light received by the light-receiving part 17 when worn to determine whether the user's skin meets a predetermined darkness condition. Then, if the darkness condition is not met (i.e., the skin is determined to be bright), a wearing determination is performed. On the other hand, if the darkness condition is met (i.e., the skin is determined to be dark), a wearing determination is not performed. As a result, the undesirable situation of being mistakenly determined not to be worn due to the darkness of the skin can be suppressed. The user's skin, which is the object of skin determination, can be bare skin or skin with cosmetics applied.

[0056] In skin assessment, if the amount of light received by the light-receiving portion 17 is below the first reference value V1, it is determined that the darkness condition is met. Here, as... Figure 4A and Figure 4B As shown, the first reference value V1 is preferably greater than the second reference value V2. Even for the same user, the amount of light received by the light-receiving part 17 when wearing the watch may vary depending on how the watch 1 is worn, the brightness of the environment, etc. Therefore, when using the second reference value V2 for skin determination, even if the skin is determined not to meet the darkness condition (i.e., it is bright skin), the amount of light received when determining whether the watch is worn will be less than the second reference value V2, sometimes resulting in a false determination that the watch is not worn. By using a first reference value V1 with a predetermined margin added to the second reference value V2 for skin determination, such false determinations can be reduced.

[0057] The skin determination method can also be as follows. That is, in the skin determination, based on the amount of light received by the light-receiving part 17 during wear, it is determined whether the user's skin meets a predetermined brightness condition. Then, if it is determined that the brightness condition is met (i.e., the skin is determined to be bright), a wear determination is performed. On the other hand, if it is determined that the brightness condition is not met (i.e., the skin is determined to be dark), a wear determination is not performed. In this case, the skin determination is determined to meet the brightness condition if the amount of light received by the light-receiving part 17 is greater than the first reference value V1.

[0058] In addition, such as Figure 4B As shown, even when the darkness condition is met and the amount of light received during wearing is less than the second reference value V2, the pulse can be detected and the pulse rate can be measured because the change in the amount of light received corresponding to the change in blood flow is detected.

[0059] Next, the pulse count measurement process for making the electronic watch 1 perform the pulse count measurement action, including the skin determination and wearing determination described above, will be explained.

[0060] Figure 5 This is a flowchart representing the control steps of the pulse count measurement process executed by CPU10.

[0061] When the pulse count measurement process begins, the CPU10 executes the pulse count measurement start process (step S101).

[0062] Figure 6 This is a flowchart representing the control steps for starting the pulse count measurement process executed by CPU10.

[0063] When the pulse count measurement start process begins, the CPU 10 determines whether there is a pulse count measurement start request (step S201). For example, if the pulse count measurement application receives a user input operation to start the pulse count measurement, it is determined that there is a pulse count measurement start request. If it is determined that there is no pulse count measurement start request ("No" in step S201), the CPU 10 executes the process of step S201 again.

[0064] If a pulse rate measurement start request is detected ("Yes" in step S201), the CPU 10 obtains the acceleration detection result of the accelerometer 18 (step S202).

[0065] CPU 10 determines whether the change in acceleration in the obtained acceleration detection results is above a predetermined judgment benchmark (step S203). If the change in acceleration is above the judgment benchmark, it is assumed that the user is wearing the electronic watch 1, and then pulse rate measurement is performed. The judgment benchmark is determined to be that the acceleration when the electronic watch 1 is worn by the user is likely to be above the judgment benchmark. That is, the judgment benchmark is set near the lower limit of the range of acceleration changes caused by the user's actions when the electronic watch 1 is worn by the user. If it is determined that the change in acceleration is less than the judgment benchmark ("No" in step S203), it can be determined that the electronic watch 1 is not worn by the user, and it is inappropriate to start pulse rate measurement. Therefore, CPU 10 does not proceed to the next step but executes step S203 again.

[0066] If the change in acceleration is determined to be above the determination threshold ("Yes" in step S203), the CPU 10 begins measuring the pulse count. Specifically, the light-emitting unit 15 is illuminated (step S204), and the detection results of the light received by the light-receiving unit 17 are periodically acquired (step S205). The pulse is detected based on the changes in the acquired light received amount. The frequency of acquiring the light received amount by the light-receiving unit 17 is not particularly limited; for example, it can be set to every 10 ms. The CPU 10 calculates the pulse count based on the pulse detection results and outputs the obtained pulse count (displayed on the display unit 12) (step S206).

[0067] When step S206 ends, CPU10 terminates the pulse count measurement process and returns the process to the previous state. Figure 5 Pulse count measurement and processing.

[0068] exist Figure 5 When the pulse count measurement process ends (step S101), the CPU10 executes the skin determination process (step S102: skin determination step).

[0069] Figure 7 This is a flowchart representing the control steps of the skin determination process performed by CPU10.

[0070] When the skin detection process begins, the CPU 10 determines whether the amount of light received by the light-receiving part 17 is below the first reference value V1 (step S301). Here, any one of the data of the amount of light received by the light-receiving part 17 obtained for pulse detection can be used for the determination.

[0071] If the light received is determined to be below the first reference value V1 ("Yes" in step S301), the CPU10 determines that the skin meets the darkness condition (step S302) and sets the value of the wearing determination execution flag to "0" (step S303).

[0072] If the light received is determined to be greater than the first reference value V1 (in step S301, it is "No"), the CPU10 determines that the skin does not meet the darkness condition (step S304) and sets the value of the wearing determination execution flag to "1" (step S305).

[0073] This skin assessment process is in Figure 6 The pulse rate measurement is performed when the change in acceleration is determined to be above the determination benchmark ("Yes" in step S203) and the pulse rate measurement has started (step S206). That is, skin determination is performed based on the amount of light received by the light-receiving part 17 when the pulse is detected. Thus, when the electronic watch 1 is worn by the user, skin determination can be performed appropriately based on the amount of light received, which reflects the brightness of the skin.

[0074] When step S303 or S305 ends, CPU10 terminates the skin determination process and returns the process to the previous state. Figure 5 Pulse count measurement and processing.

[0075] exist Figure 5 When the skin determination process (step S102) ends, the CPU10 determines whether the wearing determination execution flag is "1" (step S103). If the wearing determination execution flag is determined to be "1" ("Yes" in step S103), the CPU10 executes the wearing determination process (step S104: wearing determination step).

[0076] Figure 8 This is a flowchart representing the control steps of the wear determination process performed by CPU10.

[0077] When the wearing determination process begins, CPU10 substitutes "0" into the variable N, which represents the number of times the device is not worn (step S401).

[0078] The CPU 10 acquires the detection results of the amount of light received by the light-receiving unit 17 and the acceleration detection results of the acceleration sensor 18 (step S402). In addition, the CPU 10 determines whether the change in acceleration is above the aforementioned determination criteria based on the acquired acceleration detection results (step S403).

[0079] If the change in acceleration is determined to be less than the determination reference ("No" in step S403), the CPU 10 determines whether the amount of light received by the light-receiving part 17 is greater than the second reference value V2 (step S404). Here, if the amount of light received is determined to be less than the second reference value V2 ("No" in step S404), since the change in acceleration is less than the determination reference and the amount of light received is less than the second reference value V2 for wearing determination, there is a possibility that the electronic watch 1 is not being worn by the user. Therefore, the CPU 10 increments the variable N, which represents the number of times the watch is not worn, (step S405).

[0080] CPU 10 determines whether variable N is greater than or equal to a reference number (step S406). If variable N is less than the reference number ("No" in step S406), CPU 10 returns the process to step S402 and executes the processing loop of steps S402 to S406 again. If variable N is greater than or equal to the reference number ("Yes" in step S406), CPU 10 determines that the user is not wearing the electronic watch 1 (step S407). Thus, the processing loop of steps S402 to S406 is repeated until variable N reaches the reference number; in other words, if it is continuously determined that the user may not be wearing the watch within a predetermined time during this processing loop, step S407 is entered, and the user is determined not to be wearing the watch. The reference number is determined by the time required for variable N to reach the reference number being the predetermined time mentioned above. The predetermined time can be set arbitrarily, for example, it can be set to about 5 seconds.

[0081] On the other hand, if in step S403 it is determined that the change in acceleration is greater than or equal to a determination reference ("Yes" in step S403), or in step S404 it is determined that the amount of light received is greater than the second reference value V2 ("Yes" in step S404), the CPU 10 determines that the electronic watch 1 is being worn by the user (step S408). According to this determination method, for example, even if the user wearing the electronic watch 1 keeps their wrist still, it is possible to appropriately determine that the watch is being worn by the user based on the amount of light received by the light-receiving part 17 being greater than or equal to the second reference value V2. Therefore, compared with the determination method that only uses the detection results of the acceleration sensor 18, more accurate wearing determination can be performed.

[0082] When step S407 or step S408 ends, CPU10 terminates the wearing determination process and returns the process to the previous state. Figure 5 Pulse count measurement and processing.

[0083] exist Figure 5 When the wearing determination process (step S104) ends, the CPU 10 switches to the next process based on the wearing determination result (step S105). If the determination result is "not worn", the CPU 10 turns off the light-emitting part 15 and stops the pulse detection and pulse count measurement (step S106). Afterwards, the CPU 10 executes the pulse count measurement restart process to restart the pulse count measurement at an appropriate time when the electronic watch 1 is worn again.

[0084] Figure 9 This is a flowchart indicating the control steps for restarting the pulse rate measurement process performed by CPU10.

[0085] When the pulse rate measurement process restarts, the CPU 10 acquires the acceleration detection result from the accelerometer 18 (step S501). The CPU 10 determines whether the change in acceleration in the acquired acceleration detection result is above the aforementioned determination benchmark (step S502). If it determines that the change in acceleration is less than the determination benchmark ("No" in step S502), the process returns to step S501.

[0086] If the change in acceleration is determined to be above the determination benchmark ("Yes" in step S502), the CPU 10 illuminates the light-emitting unit 15 (step S503) and periodically acquires the detection result of the amount of light received by the light-receiving unit 17 (step S504). The frequency of acquiring the amount of light received here can be lower than the detection frequency during pulse detection, for example, it can be around tens of milliseconds.

[0087] CPU 10 determines whether the amount of light received by the light-receiving part 17 is greater than the second reference value V2 (step S505). If it is determined that the amount of light received is less than the second reference value V2 ("No" in step S505), CPU 10 again obtains the acceleration detection result of the acceleration sensor 18 and determines whether the change in acceleration is greater than or equal to the determination reference (step S506). If it is determined that the change in acceleration is less than the reference value ("No" in step S506), it can be determined that the electronic watch 1 is not being worn by the user at this stage, and it is inappropriate to start pulse rate measurement again. Therefore, CPU 10 turns off the light-emitting part 15 (step S507) and returns the process to step S501.

[0088] On the other hand, if it is determined in step S506 that the change in acceleration is above the determination benchmark ("Yes" in step S506), the CPU 10 returns the processing to step S504 and executes the processing loop of steps S504 to S506 again. Within this processing loop, if it is determined in step S505 that the amount of light received is greater than the second benchmark value V2 ("Yes" in step S505), it can be determined that the electronic watch 1 may be worn by the user. Therefore, based on further confirmation that it is being worn by the user, the CPU 10 executes the processing of steps S508 to S511 for restarting pulse rate measurement.

[0089] First, the CPU 10 determines whether the light received by the light-receiving unit 17 is greater than the second reference value V2 and whether a predetermined stability condition is met (step S508). Here, the stability condition is determined, for example, by the following method: If the smaller of the two light received values ​​acquired at the two most recent acquisition times is set as R1 and the larger light received value as R2, then if (R2-R1) / R1 is lower than a predetermined upper limit value, the stability condition is determined to be met. The aforementioned upper limit value can be appropriately set, but the smaller the upper limit value, the less likely it is that pulse rate measurement will be restarted when the device is not worn. Furthermore, the method for determining the stability condition is not limited to the above.

[0090] If it is determined that the light intensity is greater than the second reference value V2 and the stability condition is met ("Yes" in step S508), the CPU 10 begins to acquire periodic light intensity for pulse count measurement (step S509). Here, the light intensity can also be acquired at a higher frequency than that in step S504 (e.g., every 10 ms). The CPU 10 begins pulse detection based on the acquired light intensity.

[0091] CPU 10 again determines whether the amount of light received by the light-receiving part 17 is greater than the second reference value V2 and meets the predetermined stability condition (step S510). If it is determined in step S508 or step S510 that the amount of light received is less than the second reference value V2, or that the amount of light received does not meet the stability condition ("No" in steps S508 and S510), CPU 10 returns to the processing step S504.

[0092] In step S510, if it is determined that the light received is greater than the second reference value V2 and the stability condition is met ("Yes" in step S510), the CPU 10 measures the pulse count based on the pulse detection frequency, etc., outputs the obtained pulse count, and displays it on the display unit 12 (step S511). That is, the pulse count measurement starts again. The same determination as in step S508 is performed again in step S510 to restart the pulse count measurement based on the confirmation that the user has not removed the electronic watch 1 between step S508 and step S510.

[0093] When step S511 ends, CPU10 terminates pulse rate measurement and restarts processing, returning the processing to... Figure 5 Pulse count measurement and processing.

[0094] exist Figure 5 When the pulse rate measurement process ends (step S107), the CPU 10 returns the process to step S103.

[0095] In step S103, if the wearing determination execution flag is "0" ("No" in step S103), the CPU 10 does not execute the processing in steps S104 to S107, and transfers the processing to step S108. Additionally, if the wearing determination result in step S105 is "wearing", the CPU 10 also transfers the processing to step S108.

[0096] In step S108, the CPU 10 determines whether an instruction to end the pulse count measurement has been given. For example, if the pulse count measurement application receives a user input operation to end the pulse count measurement, it is determined that an instruction to end the pulse count measurement has been given. If it is determined that no such instruction has been given ("No" in step S108), the CPU 10 returns the process to step S103. If it is determined that an instruction to end has been given ("Yes" in step S108), the CPU 10 turns off the light-emitting unit 15 and stops the detection of the pulse and the measurement of the pulse count (step S109), ending the pulse count measurement process.

[0097] (Effect)

[0098] As described above, the electronic watch 1, which is an electronic device worn by a user according to this embodiment, includes: a light-emitting unit 15 that emits light to the user's skin; a light-receiving unit 17 that is positioned to receive light reflected from the user's skin when the device is worn by the user and when the light-emitting unit 15 emits light; and a CPU 10 that functions as a control unit. The CPU 10, as the control unit, determines whether the user's skin meets a predetermined darkness condition based on the amount of light received by the light-receiving unit 17. Furthermore, the CPU 10, as the control unit, determines whether the device is being worn by the user based at least on the amount of light received by the light-receiving unit 17; if the darkness condition is met in the skin determination, no wearing determination is performed. Therefore, the wearing status can be appropriately determined. For example, it makes it difficult to misjudge whether the electronic watch 1 is being worn by the user.

[0099] Furthermore, the CPU10, as the control unit, determines whether the wear condition is met during skin detection. Therefore, by performing the wear determination under bright skin conditions, it is less likely to misjudge the wearer as not wearing the skin due to insufficient light reflected from the skin.

[0100] Furthermore, the CPU 10, serving as the control unit, detects the pulse based on changes in the amount of light received by the light-receiving unit 17. In this structure, the light-emitting unit 15 and the light-receiving unit 17 used for pulse detection can be used for skin determination. Therefore, it is possible to avoid complicating the structure of the electronic watch 1 and increasing manufacturing costs, and to perform skin determination without easily generating false readings.

[0101] Furthermore, the CPU 10, which serves as the control unit, determines the skin condition based on the amount of light received by the light-receiving unit 17 when detecting a pulse. Thus, when the electronic watch 1 is worn by the user, the skin condition can be appropriately determined based on the amount of light received, which reflects the brightness of the skin.

[0102] Furthermore, in skin determination, the CPU 10, which serves as the control unit, determines that the darkness condition is met when the amount of light received by the light-receiving unit 17 is below the first reference value V1. Therefore, skin determination can be performed with simple processing.

[0103] Furthermore, in the wear determination process, the CPU 10, as the control unit, determines that the device is being worn by the user if the light received by the light-receiving unit 17 is greater than the second reference value V2, and the first reference value V1 is greater than the second reference value V2. Thus, by using a first reference value V1, which is larger than the second reference value V2 used in the wear determination, skin detection is performed. Even if the light received during the wear determination decreases from the first reference value V1 due to factors such as the wearing method or the brightness of the environment, a false determination that the device is not being worn will not be made immediately.

[0104] Furthermore, the electronic watch 1 is equipped with an accelerometer 18 that detects the acceleration of the device. The CPU 10, as the control unit, performs skin assessment when the change in acceleration detected by the accelerometer 18 is above a predetermined judgment threshold. Thus, when the electronic watch 1 is worn by the user, skin assessment can be appropriately performed based on the amount of light received, which reflects the brightness of the skin.

[0105] Furthermore, the control method for the electronic watch 1 in this embodiment includes: a skin determination step, which determines whether the user's skin meets a predetermined darkness condition based on the amount of light received by the light-receiving part 17; and a wearing determination step, which determines whether the device is being worn by the user based at least on the amount of light received by the light-receiving part 17. If the darkness condition is met in the skin determination step, the wearing determination step is not performed. This allows for appropriate determination of the wearing status. For example, it makes it difficult to misjudge whether the electronic watch 1 is being worn by the user.

[0106] Furthermore, the program 111 of this embodiment enables the CPU 10, which functions as a computer and is installed in the electronic watch 1 as an electronic device, to function as a control unit. This control unit determines whether the user's skin meets a predetermined darkness condition based on the amount of light received by the light-receiving section 17. Additionally, the control unit determines whether the device is being worn by the user, at least based on the amount of light received by the light-receiving section 17. If the darkness condition is determined to be met during the skin determination, no wearing determination is performed. By using this program 111 to operate the electronic watch 1, the wearing status can be appropriately determined. For example, it makes it difficult to misjudge whether the electronic watch 1 is being worn by the user.

[0107] (other)

[0108] Furthermore, the descriptions in the above embodiments are examples of the electronic device, control method, and program of the present invention, and are not limited thereto.

[0109] For example, an electronic watch 1 is exemplified as an electronic device, but it is not limited to this. For example, the electronic device can be various wearable devices such as an activity meter. Furthermore, the electronic device only needs to have a light-emitting part and a light-receiving part for skin detection and wear determination, and is not limited to electronic devices capable of pulse detection. In electronic devices that do not perform pulse detection, for example, if the change in acceleration is greater than or equal to the aforementioned determination condition, it can be considered as being worn by the user for skin detection. Furthermore, the wearing position of the electronic device is not limited to the wrist.

[0110] In addition, as exemplified by electronic watch 1, an electronic watch that displays numbers in a dot matrix format is shown, but it is not limited to this. An analog electronic watch that displays at least a portion of information such as time and pulse count by means of pointers can also be used.

[0111] Furthermore, examples of using pulse detection results for pulse rate measurement have been given and explained, but this is not an limitation. Pulse detection results can also be used, for example, to display heartbeat pulses or to perform flashing displays corresponding to pulsation.

[0112] Furthermore, the example described uses skin determination processing to rewrite the wear determination execution flag 112 each time a pulse count measurement is performed, but it is not limited to this. In cases where it is possible to identify the user currently using the electronic watch 1, or where multiple users are not considered, the skin determination result from the initial pulse count measurement process can be used for subsequent pulse count measurement processes. In this case, the content of the wear determination execution flag 112 determined in the skin determination processing of the initial pulse count measurement process is stored in the memory 11 as setting data corresponding to the user. In subsequent pulse count measurement processes, the wear determination is determined based on this setting data.

[0113] Furthermore, while the above description discloses an example of using non-volatile memory 11 as a computer-readable medium for the program of the present invention, it is not limited to this example. Other computer-readable media include information recording media such as HDDs, SSDs, flash memory, and CD-ROMs. Additionally, a carrier wave is also suitable as a medium for providing data for the program of the present invention via a communication line.

[0114] Furthermore, the detailed structure and operation of each component of the electronic watch 1, which is the electronic device in the above embodiment, can of course be appropriately modified without departing from the spirit of the present invention.

[0115] The embodiments of the present invention have been described, but the scope of the present invention is not limited to the embodiments described above, but includes the scope of the invention as described in the scope of the patent claim and its equivalents.

[0116] This application is based on Japanese Patent Application No. 2021-051401, filed on March 25, 2021. The entire description, claims, and drawings of Japanese Patent Application No. 2021-051401 are incorporated herein by reference.

[0117] Industrial utilization potential

[0118] According to the present invention, the wearing status can be appropriately determined.

[0119] Symbol Explanation

[0120] 1. Electronic watch (electronic device)

[0121] 2 Main body

[0122] 3 watch straps

[0123] 10. CPU (Control Unit, Control Unit)

[0124] 11. Memory

[0125] 111 Program

[0126] 112 Wearing the judgment enforcement badge

[0127] 12 Display Section

[0128] 121 Display Screen

[0129] 13 Operation Receiving Unit

[0130] 131 Operation Button

[0131] 141 Oscillating Circuit

[0132] 142 frequency divider circuit

[0133] 143 Timing Circuit

[0134] 15 Light-emitting parts

[0135] 16 Light-emitting drive unit

[0136] 17. Light-receiving section

[0137] 18 Accelerometers

[0138] 19 A / D converters

[0139] V1 First Reference Value

[0140] V2 Second Baseline Value.

Claims

1. An electronic device worn by a user, characterized in that, The electronic device includes: A light-emitting part that emits light toward the user's skin; A light-receiving part, disposed at a position whereby, when the device is worn by the user and when the light-emitting part emits light, it can receive light reflected from the user's skin; and Control Department The control unit determines whether the user's skin meets a predetermined darkness condition based on the amount of light received by the light-receiving part. If the skin condition is determined not to meet the darkness condition, the control unit determines whether the device is worn by the user based at least on the amount of light received by the light-receiving part. If the skin condition is determined to meet the darkness condition, the wear determination is not performed.

2. The electronic device according to claim 1, characterized in that, If the control unit determines that the skin tone does not meet the darkness condition during the skin tone determination, it will repeat the wearing determination.

3. The electronic device according to claim 1 or 2, characterized in that, The control unit detects the pulse based on changes in the amount of light received by the light-receiving unit.

4. The electronic device according to claim 3, characterized in that, The control unit determines the skin condition based on the amount of light received by the light-receiving part when the pulse is detected.

5. The electronic device according to claim 1 or 2, characterized in that, In the skin determination, the control unit determines that the darkness condition is met when the amount of light received by the light-receiving part is below a first reference value.

6. The electronic device according to claim 5, characterized in that, In the wearing determination, if the amount of light received by the light-receiving part is greater than a second reference value, the control unit determines that the device is being worn by the user. The first benchmark value is greater than the second benchmark value.

7. The electronic device according to claim 1 or 2, characterized in that, The electronic device is equipped with an acceleration sensor that detects the acceleration of the device itself. The control unit performs the skin determination when the change in acceleration detected by the acceleration sensor is above a predetermined determination threshold.

8. A method for controlling an electronic device, the electronic device being worn by a user, the electronic device comprising: a light-emitting portion that emits light toward the user's skin; And a light-receiving part, which is disposed at a position whereby the device can receive the light reflected from the user's skin when the light-emitting part emits the light, characterized in that, The control method includes: Based on the amount of light received by the light-receiving part, a skin determination step is performed to determine whether the user's skin meets the predetermined darkness condition. as well as If the darkness condition is not met in the skin determination step, a wearing determination step is performed to determine whether the device is being worn by the user, based at least on the amount of light received by the light-receiving part. If the skin condition is deemed to meet the darkness requirement during the skin determination step, the wearing determination step will not be performed.

9. A computer-readable recording medium recording a program executed by a computer, the computer being disposed in an electronic device worn by a user, the electronic device comprising: a light-emitting unit that emits light toward the user's skin; and a light-receiving unit disposed at a position capable of receiving light reflected from the user's skin when the device is worn by the user and when the light-emitting unit emits the light, characterized in that, The program enables the computer to function as a control unit. The control unit performs a skin determination based on the amount of light received by the light-receiving part to determine whether the user's skin meets the predetermined darkness condition. If the skin determination determines that the darkness condition is not met, a wearing determination is performed based at least on the amount of light received by the light-receiving part to determine whether the device is worn by the user. If the skin determination determines that the darkness condition is met, the wearing determination is not performed.

Images