Wearable device, attachment determination method, and program

Abstract

To provide a wearable device, a device determination method, and a program capable of correctly determining an attachment state.SOLUTION: An electric device (1) being a wearable device includes a pulse sensor (23) and a CPU (11). The pulse sensor (23) includes: a light emission part (231) that emits light; and a light reception part (232) that detects reflection light of light that has been emitted by the light emission part (231) and reflected on an incident surface, in a plurality of regions arranged side by side. The CPU (11) determines an attachment state with respect to a body according to a change in a light reception pattern of the reflection light in the plurality of regions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a wearable device, a wearing determination method, and a program. [Background technology]

[0002] 2. Description of the Related Art Wearable devices worn on the wrist or the like include those equipped with a body temperature sensor, a pulse sensor, and the like.

[0003] Patent Document 1 discloses a technique for detecting looseness in the wearing state of a device according to the tendency of changes in biological data such as body temperature and heart rate obtained from a body temperature sensor and a pulse sensor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-10881 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with specifications that determine the wearing status based on the changing trends of biometric data, there is a problem in that even if the device is worn correctly, it may be mistakenly determined to be not being worn depending on the user's physical condition.

[0006] An object of the present invention is to provide a wearable device, a method of determining whether the device is being worn, and a program that can more accurately determine the state of wearing of the device. [Means for solving the problem]

[0007] In order to achieve the above object, the present disclosure provides: an optical sensor including a light-emitting unit that emits light and outputs light, and a light-receiving unit that detects reflected light that is the light emitted by the light-emitting unit reflected by an incident surface in a plurality of areas arranged side by side; a processing unit that determines a state of attachment to the body in accordance with a change in a light receiving pattern of the reflected light in the plurality of regions; It is a wearable device equipped with [Effects of the Invention]

[0008] The present disclosure has the effect of enabling the wearing state of a wearable device to be determined more accurately and simply. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing the rear surface of the electronic device. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of the electronic device. [Figure 3] FIG. 10 is a diagram illustrating an example of a relative movement range for matching. [Figure 4] FIG. 10 is a diagram illustrating relative movement. [Figure 5] 10 is a flowchart showing a control procedure for removal detection processing. [Figure 6] 10 is a flowchart showing a control procedure of another example of the removal detection process. [Figure 7] 10 is a flowchart showing a control procedure for operation detection processing. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will now be described with reference to the drawings. Electronic device 1 of this embodiment is a wrist-worn wearable device that can be worn on a user's body, in this case, on the wrist (arm), such as an electronic wristwatch or smartwatch. As shown in FIG. 1 , the back surface, which is the surface that comes into contact with the wrist, is sealed by a back cover 4. Back cover 4 has light exit ports 41G and 41R and a light entrance port 42. Exit ports 41G, 41R, and entrance port 42 are each covered with a light-transmitting member. Green light is emitted from exit port 41G, and red light and infrared light are emitted from exit port 41R. Light from the outside is incident through entrance port 42. When electronic device 1 is worn on the wrist and light is emitted from exit port 41G and / or exit port 41R, the light reflected by the wrist enters through entrance port 42.

[0011] As shown in FIG. 2, the electronic device 1 includes a CPU 11 (Central Processing Unit) (processing unit), a RAM 12 (Random Access Memory), a storage unit 13, a communication unit 14, a display operation unit 15, an operation reception unit 16, an alarm operation unit 17, an oscillation circuit 181, a frequency division circuit 182, a timing circuit 19, a measurement unit 20, and the like.

[0012] The CPU 11 is a processor that performs arithmetic processing and controls the overall operation of the electronic device 1. The CPU 11 may have a single processor, or may have multiple processors that operate in parallel or independently.

[0013] The RAM 12 provides a working memory space for the CPU 11 and stores temporary data. The RAM 12 may be a DRAM or other volatile memory.

[0014] The storage unit 13 is a non-volatile memory and stores a program 131 and various data. The storage unit 13 may be a flash memory or the like.

[0015] The communication unit 14 controls communication with external electronic devices in accordance with a communication protocol. The communication unit 14 may be capable of controlling communication via Bluetooth (registered trademark), for example.

[0016] The display operation unit 15 controls the display under the control of the CPU 11. The display operation unit 15 may have a digital display screen, or may have hands and a gear train or motor for rotating the hands. The digital display screen may be, for example, a liquid crystal display or an organic EL (Electro-Luminescent) display. The hands may have three hands capable of displaying the hour, minute, and second of the time, or may have more hands. Some of the hands may be small hands that rotate on a part of the display surface. The motor may be a stepping motor.

[0017] The operation reception unit 16 includes a push button switch or the like, receives input operations from the user, and outputs an electrical signal corresponding to the received input operation to the CPU 11. The operation reception unit 16 may further include a crown, a touch panel positioned to overlap the digital display screen of the display operation unit 15, or the like.

[0018] The annunciation operation unit 17 performs an annunciation operation such as emitting a beep and / or generating a vibration under the control of the CPU 11. The annunciation operation unit 17 has an operation mechanism corresponding to the possible annunciation operations. The operation mechanism may have a known configuration.

[0019] Oscillator circuit 181 has a quartz crystal element or the like, and oscillates at its resonant frequency to output a clock signal. Divider circuit 182 divides the clock signal to a predetermined appropriate frequency and outputs a divided signal. Divider circuit 182 may have a logical speed reducing / speed adjusting circuit that thins out the output signal at an appropriate rate depending on the wave number of the resonant frequency of the clock signal. Timekeeping circuit 19 counts the output signal from the divided signal and adds up the count number to calculate the current time. The current time may include the date.

[0020] The measurement unit 20 has a plurality of physical sensors, converts the results of measurements by the physical sensors into digital data, and outputs the digital data to the CPU 11. The measurement unit 20 has, for example, an acceleration sensor 21 (acceleration measurement unit), an illuminance sensor 22, a pulse sensor 23, and the like.

[0021] The acceleration sensor 21 measures the acceleration of the electronic device 1. The acceleration may be measured in a total of three axial directions, for example, two axial directions that are orthogonal to each other within the display surface and one axial direction that is perpendicular to the display surface. The acceleration sensor 21 may be a well-known semiconductor sensor. The acceleration is digitized at an appropriate sampling frequency and output to the CPU 11.

[0022] Illuminance sensor 22 measures the amount of light incident on the display surface. Illuminance sensor 22 may have, for example, a semiconductor light-receiving element such as a photodiode. An electrical signal corresponding to the amount of incident light is digitized at an appropriate sampling frequency and output to CPU 11. The measurement results of acceleration sensor 21 and illuminance sensor 22 may be synchronized and output to CPU 11, or may be output to CPU 11 independently. The sampling frequency may be changed or set depending on the operating state of electronic device 1.

[0023] The pulse sensor 23 measures the pulse of the user wearing the electronic device 1. The pulse sensor 23 is a PPG (photoplethysmography) sensor, i.e., an optical sensor. The pulse sensor 23 includes a light-emitting unit 231 and a light-receiving unit 232. When the electronic device 1, i.e., the pulse sensor 23, is fixed and worn on a target body part of the user's body, i.e., the wrist, light emitted from the light-emitting unit 231 and emitted from the light-emitting ports 41G and 41R enters the user's wrist. The light that enters the wrist is reflected by the wrist, which is the incident surface. Note that the incident surface here does not mean a flat surface. In other words, it includes light reflected not only on the surface of the wrist but also inside the wrist. The reflected light reflected by the wrist enters through the light-receiving port 42 and is detected by the light-receiving unit 232. The reflected green light periodically changes in response to blood flow corresponding to the pulse. The pulse can be obtained based on this periodic change. Meanwhile, the infrared light may be used to determine whether the device is worn on the wrist. The red light may be emitted together with the red light and used in conjunction with determining whether the device is worn on the wrist, or may be used to notify whether invisible infrared light is being emitted.

[0024] As described above, the light-emitting unit 231 has a first light-emitting body 231G that emits green light from the emission port 41G and a second light-emitting body 231R that emits red light and infrared light from the emission port 41R. The red light-emitting body and the infrared light-emitting body that emits infrared light may be separate. The light-emitting unit 231 may be a light-emitting diode that emits light at the respective wavelengths. The type of light emitted by the light-emitting unit 231, for example, the emission of green light and red light, may be switchable under the control of the CPU 11 depending on the above-mentioned application.

[0025] The light-receiving unit 232 has a light-receiving element and detects the amount of incident light. That is, when the electronic device 1 is worn on the wrist, the light-receiving unit 232 detects the amount of light reflected from the wrist after light is incident on the wrist from the light-emitting unit 231. The light-receiving element may be common to all wavelengths, or different light-receiving elements may be used for each wavelength. The light-receiving element may be a photodiode. The light-receiving unit 232 can detect the amount of received light in each of multiple regions corresponding to the light-receiving elements arranged in a two-dimensional matrix, for example. That is, each region corresponds to a pixel. The light-receiving unit 232 can obtain a light-receiving pattern, which is a spatial distribution of the amount of received light corresponding to the number of pixels. The regions may be arranged in an array of, for example, approximately 10 x 10. The number of regions may be determined so that the translation of the spatial pattern of the amount of received light can be recognized, as described below, and based on an appropriate processing load. Of the components of the electronic device 1 described above, at least the CPU 11, RAM 12, and storage unit 13 are included in the main body of the computer of this embodiment.

[0026] Next, detection of the wearing / removal operation of the electronic device 1 will be described. As described above, when the electronic device 1 is worn on the user's wrist, the pulse can be measured by the operation of the pulse sensor 23. When the electronic device 1 is not worn on the wrist, the emitted light of the light-emitting unit 231, which is originally intended to be incident light on the wrist, is prevented from irradiating unintended locations. For this reason, the electronic device 1 stops the light-emitting operation of the light-emitting unit 231, particularly the emission of green light, or reduces the amount of light emitted.

[0027] The CPU 11 of this embodiment may simply stop the operation of the light-emitting unit 231 when the amount of light detected by the light-receiving unit 232 decreases due to the disappearance of reflected light, particularly infrared light. However, in this case, light emitted from the light-emitting unit 231 may be reflected by an unintended surface, such as a desk or table, and detected by the light-receiving unit 232, or the amount of detected light may increase due to sunlight, a heating appliance, or a cooking appliance. In addition to or instead of the above, as a wearing determination method of the present embodiment, the CPU 11 acquires a distribution (light-receiving pattern) of the amount of light detected by the light-receiving unit 232 in multiple regions, i.e., at each pixel position. The CPU 11 obtains changes in this light-receiving pattern over time and determines the wearing state of the electronic device on the wrist based on changes in the light-receiving pattern (the amount of light received in multiple regions). More specifically, the CPU 11 may determine that the electronic device 1 is no longer worn on the wrist and has been removed when it detects that the light-receiving pattern has moved in a specific direction (first direction). Note that a single movement alone is difficult to distinguish from accidental misalignment. Therefore, the CPU 11 may determine that the electronic device 1 has been removed when movement in the first direction is continuously detected in the results of multiple comparisons within a specified time, for example, 0.2 seconds.

[0028] Such a change in the light reception pattern may occur intentionally by the user. That is, the user can intentionally inform the CPU 11 that the electronic device 1 has been removed from the wrist by sliding a fingertip or the like in the first direction along the light exit ports 41G, 41R and the light entrance port 42 of the removed electronic device 1. Therefore, relative movement in the opposite direction to the first direction does not need to be detected. Such a simple operation can be easily performed without the user having to visually recognize their own finger or the like, so the emitted light from the light-emitting unit 231 is unlikely to be irradiated onto the user's face, particularly the eyes.

[0029] The first direction may be, for example, the top-to-bottom orientation of the display on the display surface, or the direction from 12 o'clock to 6 o'clock if the hands are capable of displaying time. By detecting parallel movement within a certain angle range relative to this first direction, for example, within a range of ±30 degrees, the detection of movement in an unintended direction is reduced.

[0030] The movement of the fingertip relative to the light entrance 42 may be detected using a conventional technique, such as matching 10 × 10 images taken at two different times while moving the images one pixel at a time in the aforementioned direction. That is, the relative movement of the electronic device 1 relative to the wrist may be determined by calculating the cross-correlation between the two images. When an angular width is set for the first direction as described above, relative movement also occurs within the angular width in a direction perpendicular to the first direction. As shown in FIG. 3, relative movement may occur, and only a positional shift within the 30-degree range indicated by the dashed line L may be detected. For example, if the light reception pattern R1 shown in FIG. 3 is detected, and then the light reception pattern R2 shown in FIG. 4 is detected, the movement indicated by the arrow M will result in the highest degree of match. The light reception patterns R1 and R2 may not have the same shape. Because this movement corresponds to a positional shift within the 30-degree range indicated by the dashed line L, the CPU 11 can identify a parallel movement in the first direction. Furthermore, when the finger is large compared to the exit aperture 41G and the entrance aperture 42, the portion covered by the finger changes more simply in the order of the 12 o'clock side exit aperture 41G, the central entrance aperture 42, and the 6 o'clock side exit aperture 41G. Therefore, a characteristic change over time in the amount of received light corresponding to this change may be detected.

[0031] The relative movement speed is obtained based on the acquisition interval of the light reception data and the speed of the relative deviation amount at which a high correlation is obtained or the speed of the time change of the amount of light reception. The acquisition interval and the range of the deviation amount may be determined so that only relative movement within a speed range determined to be appropriate for user operation is detected.

[0032] 5 is executed by reading out the program 131 every time the CPU 11 acquires light reception data from the light receiving unit 232. The CPU 11 acquires detection data from the light receiving unit 232 (S1).

[0033] The CPU 11 determines the degree of matching between the acquired current detection data and the previous detection data while shifting the data in a specific direction within a set shift range (S2).The CPU 11 determines whether there is high-correlation data between the detection data whose degree of matching is higher than a standard (S3).

[0034] If it is determined that high correlation data was present (S3; Y), the CPU 11 determines that a removal operation was performed (S4). As described above, if the CPU 11 determines in process S3 that high correlation data was present multiple times in succession within a specified time, the process may branch to "Y". The CPU 11 stops the light emitting operation of the light emitting unit 231 (S5). The operation of the light receiving unit 232 may be stopped at the same time, or may be continued. Then, the CPU 11 ends the removal operation detection process. If it is determined that high correlation data was not present (S3; N), the CPU 11 determines that a removal operation was not performed (S5). Then, the CPU 11 ends the removal detection process.

[0035] The processes S2 to S4 correspond to the determination means in the program 131 of this embodiment. Note that, depending on the interval at which light reception data is acquired, comparison may be made not only with the most recent two pieces of light reception data but also with light reception data from two or more previous pieces.

[0036] Alternatively, the result may be compared with a reference value each time a matching operation is performed while changing the amount of relative movement. If highly correlated data is obtained at a certain amount of relative movement, the process of matching based on the amount of relative movement thereafter may be stopped.

[0037] Furthermore, if there is no relative movement, a high correlation is obtained between the images when the shift amount is zero or a very small range, and therefore the CPU 11 may determine that there is no change in the wearing state in this case.

[0038] Note that even if the electronic device 1 is actually removed from the wrist, for example, if the removal is temporary, such as to wipe away sweat, the light-emitting unit 231 does not necessarily have to stop emitting light. In this embodiment, if the electronic device 1 is reattached to the user's wrist without the user intentionally removing the electronic device 1 as described above, the light-emitting unit 231 may maintain its emitting state. Since the pulse rate is not measured while the electronic device 1 is removed from the wrist, an error may be output, or the output of the result may be omitted. Conversely, once removal is detected and the light-emitting unit 231 stops emitting light, the light-emitting unit 231 may be set not to resume emitting light in response to wearing for a reference time. Immediately after removal, the wearing of the electronic device may be erroneously detected due to cleaning, storage, or other operations. The above-mentioned reference time limit reduces the possibility of unnecessary resumption of light emission. The reference time may be, for example, 10 seconds to 1 minute, but is not limited thereto.

[0039] The acceleration sensor 21 and the illuminance sensor 22 may be used to detect whether the electronic device 1 is being worn when the operation of the pulse sensor 23 is stopped. When the user is wearing the electronic device 1, the acceleration sensor 21 detects a change in acceleration, and often detects an illuminance above a certain reference level on the display surface side. Even if the illuminance sensor 22 does not detect an illuminance above the reference level due to the influence of nighttime or the sleeves of clothing, the acceleration sensor 21 detects a change in acceleration. If these detections are not sporadic but are measured continuously for a lower limit time or longer, it may be determined that the electronic device 1 is likely to be worn. The lower limit time may be set to, for example, several seconds to 10 seconds, but is not particularly limited to this range.

[0040] In this case, for example, only the operation of light receiving unit 232 of pulse sensor 23 may be resumed first. Alternatively, the operation of light receiving unit 232 may continue even if the operation of light emitting unit 231 is stopped. For example, if the amount of light detected by light receiving unit 232 when light emitting unit 231 is stopped is greater than the illuminance detected on the display surface by illuminance sensor 22, electronic device 1 may be determined to be not worn on the wrist. Furthermore, if the amount of light detected by light receiving unit 232 does not change by more than a reference value even after the light emitting operation of light emitting unit 231 is resumed, it may be determined that electronic device 1 is being carried without being worn on the wrist.

[0041] In the above description, a change in the amount of light detected by the light receiving unit 232 is used to detect whether the electronic device 1 has been removed from the wrist. In addition, the electronic device 1 may also be capable of detecting whether the electronic device 1 has not been removed but is loosely attached to the wrist due to insufficient fastening. When the electronic device 1 is loosely attached, a change in the spatial distribution of the amount of detected light (light receiving pattern) accompanying the relative movement of the electronic device 1 with respect to the wrist is expected to occur in response to the movement of the arm or body. For example, when the electronic device 1 is loosely attached, it may be unable to keep up with the acceleration of the arm or body and may move in a direction opposite to the directional component of the acceleration along the wrist. As a result, the light receiving unit 232 detects a change in the light receiving pattern of the directional component of the wrist along the wrist. Therefore, when the electronic device 1 detects a change in the light receiving pattern in a direction corresponding to the acceleration detected by the acceleration sensor 21, the electronic device 1 may determine that the electronic device is loosely attached.

[0042] Furthermore, the electronic device 1 may more actively utilize the detection of the amount of light detected by the light receiving unit 232 to accept other input operations by the user when the electronic device 1 is not being worn. For example, relative movement of a finger or the like relative to the light receiving unit 232 in a direction different from the first direction, particularly from the opposite direction, from the 6 o'clock direction to the 12 o'clock direction (second direction), may be utilized to change the amount of light emitted by the light emitting unit 231 or the wavelength of light emitted. Specifically, when movement from the 12 o'clock direction to the 6 o'clock direction (first direction) is detected, the light emitting operation may be stopped, and when movement from the 6 o'clock direction to the 12 o'clock direction (second direction) is detected, the wavelength of light emitted may be switched from green light to red light. In this case, the presence or absence of movement may be determined both in the 6 o'clock direction and the 12 o'clock direction. In this case, when movement in the second direction is detected, the CPU 11 may determine that the amount of light detected by the light receiving unit 232 is utilized to accept other input operations by the user.

[0043] 6, steps S6, S8, and S11 to S13 are added to the above-described removal operation detection process, and steps S2 and S3 are replaced with steps S2a and S3a. The other steps are the same, and the same reference numerals are used to designate them, and detailed descriptions thereof will be omitted.

[0044] After step S1, the CPU 11 compares the received light pattern with the previous detection data to detect relative movement of the received light pattern (S2a). The CPU 11 determines whether movement of the received light pattern has been detected (S3a). If it is determined that movement has not been detected (S3a; N), the CPU 11 proceeds to step S5.

[0045] If it is determined that movement of the light receiving pattern has been detected (S3a; Y), CPU 11 determines whether the movement corresponds to an acceleration change detected by acceleration sensor 21, particularly a movement of the body or arm (S11). If it is determined that the movement does not correspond to an acceleration change (S11; N), CPU 11 proceeds to process S4. If it is determined that the movement corresponds to an acceleration change (S11; Y), CPU 11 determines that electronic device 1 has not been removed, but that loosening of the attachment state to the wrist has been detected (S12). CPU 11 causes notification unit 17 to perform a notification operation to notify of loosening of the attachment state (S13). Then, CPU 11 ends the removal detection process.

[0046] After step S4, CPU 11 determines whether the movement of the light receiving pattern is downward, i.e., from the 12 o'clock direction to the 6 o'clock direction (S6). If it is determined that the movement of the light receiving pattern is downward (S6; Y), the process of CPU 11 proceeds to step S7. If it is determined that the movement of the light receiving pattern is not downward (S6; N), CPU 11 switches the light emission color of light-emitting unit 231 from green to red (S8). At this time, CPU 11 may allow light-emitting unit 231 to continue emitting infrared light. Then, CPU 11 ends the removal operation detection process.

[0047] In the state where the emission of red light is switched to, an input operation corresponding to the direction and / or speed of the relative movement of the user's finger, etc. may be accepted. In this case, the accepted content corresponding to the input operation may be defined in advance or may be determined according to the display content by the display operation unit 15.

[0048] 7 includes the same processes as S1, S2a, and S3a of the above-described removal operation detection process, and also includes processes S21 to S23. The same process contents are assigned the same reference numerals, and detailed explanations will be omitted.

[0049] If it is determined in the determination process of process S3a that relative movement has not been detected (S3a; N), the process of the CPU 11 returns to process S1. If it is determined that relative movement has been detected (S3a; Y), the CPU 11 identifies the movement direction and movement speed (S21). The CPU 11 refers to the processing content corresponding to the content displayed by the display operation unit 15, i.e., the setting of the operation request. The CPU 11 acquires and sets the processing content corresponding to the movement direction and movement speed from the reference setting (S22). The CPU 11 executes the set processing content (S23). Then, the process of the CPU 11 returns to process S1.

[0050] The set process may include the termination of a process related to operation detection. In this case, the operation detection process is terminated by the execution of the process. Other processes may include, for example, setting an alarm notification operation on or off or setting the alarm notification time. For example, the alarm notification time may be changed forward or backward depending on the direction of the movement. Furthermore, the display content may be changed depending on the detected operation. The change in the display content may include the rotation of the hands. The rotation of the hands may indicate, for example, a change in the alarm notification time as described above. Furthermore, for example, when a notification obtained from an external device by the communication unit 14 can be displayed on the digital display screen, the displayed notification may be switched or a long notification may be scrolled depending on the detected operation.

[0051] As described above, the electronic device 1 of this embodiment is a wearable device that can be worn on the body, for example, on the wrist. The electronic device 1 includes a pulse sensor 23 and a CPU 11. The pulse sensor 23 includes a light-emitting unit 231 that emits light and a light-receiving unit 232 that detects light reflected from an incident surface of the light-emitting unit 231 in multiple aligned regions. The CPU 11 determines the attachment state of the electronic device to the body based on changes in the light-receiving pattern of the reflected light in the multiple regions. In this way, the electronic device 1 can detect removal or loosening of the electronic device 1 based not only on the reflection intensity of infrared light, etc., but also on changes in the light-receiving pattern. Such changes in the light-receiving pattern corresponding to clear changes in the relative position between the electronic device 1 and the body are easily detected. This reduces the possibility of false detection and allows the electronic device 1 to more accurately detect the attachment state of the electronic device to the user. Therefore, the electronic device 1 can reduce unnecessary light emission from the light-emitting unit 231 and notify the user of loose attachment.

[0052] Furthermore, the light receiving unit 232 may be capable of detecting the amount of light received reflected from the incident surface in each of the multiple regions. The CPU 11 may detect a change in the light receiving pattern based on a change in the amount of light received reflected from the incident surface in the multiple regions. By obtaining a spatial distribution of the amount of received light using an array of multiple light receiving elements, the electronic device 1 can easily detect a change in the light receiving pattern.

[0053] The electronic device 1 may also include an acceleration sensor 21. The CPU 11 may detect a change in the light reception pattern of the light receiving unit 232, and if this change is detected in correspondence with the detection of body movement by the acceleration sensor 21, determine that the electronic device is not worn loosely. If the electronic device 1 is not worn securely, the accuracy of pulse measurement by the pulse sensor 23 may decrease, or pulse measurement itself may become difficult. Therefore, the electronic device 1 can determine whether the electronic device is worn securely at a required level. In other words, the electronic device 1 can more accurately determine the wearing state through the operation of the light emitting unit 231 and the light receiving unit 232 without requiring any additional configuration.

[0054] Furthermore, the CPU 11 may determine that the electronic device 1 is loosely fitted when a change in the light-receiving pattern is detected at a predetermined cycle while the electronic device 1 is set to a predetermined mode. In some operation modes, for example, operation modes executed while the body, particularly the wrist, is moving periodically, the electronic device 1 is likely to move periodically relative to the body in response to the periodic movement. Therefore, in such operation modes, the electronic device 1 can accurately detect loose fitting.

[0055] Furthermore, the electronic device 1 may include an announcing unit 17. When the CPU 11 determines that the device is loosely attached, the announcing unit 17 may perform an announcing operation indicating that the device is loosely attached. This allows the electronic device 1 to encourage the user to attach the device securely, and allows the pulse sensor 23 to perform measurement with higher accuracy.

[0056] Furthermore, when movement of the light-receiving pattern in the first direction is detected, the CPU 11 may stop light emission from the light-emitting unit 231. The electronic device 1 can quickly stop light emission from the light-emitting unit 231 by a movement action in a specific direction that the user easily and intentionally performs. Therefore, the electronic device 1 can reduce irradiation of light to unintended targets. This also allows the electronic device 1 to reduce power consumption due to unnecessary light emission.

[0057] Furthermore, the CPU 11 may detect movement of the light-receiving pattern, identify at least one of the direction and speed of movement of the light-receiving pattern, and accept a request for an operation according to the identified result. That is, the electronic device 1 may be able to perform operation detection by combining the light-emitting unit 231 and the light-receiving unit 232, in addition to its original function as a pulse sensor 23. For an electronic device 1 worn on the wrist, adding a touch panel tends to increase the device's thickness. It is also difficult for the electronic device 1 to have many button switches. By utilizing the pulse sensor 23 for operation detection, the range of operation acceptance can be expanded more efficiently, and the number of complex combinations of operations involving a limited number of button switches can be reduced.

[0058] Furthermore, CPU 11 identifies at least the direction of movement of the light-receiving pattern. When CPU 11 detects movement of the light-receiving pattern in a second direction different from the first direction, CPU 11 may change at least one of the amount of light and wavelength of light emitted by light-emitting unit 231 to enable acceptance of an operation request. That is, electronic device 1 may change at least one of the amount of light emitted from light-emitting unit 231, i.e., the amount of light incident on the body (wrist or fingers) and wavelength (color), between measuring a pulse and using electronic device 1 as an operation acceptance unit. By appropriately switching between green light used for pulse detection and light such as red or blue that is suitable for accepting operations, pulse sensor 23 can be used more appropriately for multiple operations.

[0059] The electronic device 1 also includes a display operation unit 15. The operation request may include a request to change the display content by the display operation unit 15. The change in the display content may include switching the display content on the digital display screen or rotating the pointer. For example, the operation of this embodiment can be suitably used when quantitatively indicating the amount of change, such as rotating the pointer or scrolling the display content. Furthermore, when there are many display changes or switching, the operation burden tends to be less than repeatedly operating small button switches, etc.

[0060] Furthermore, the wearing determination method for the electronic device 1, which is a wearable device, of this embodiment determines the wearing state of the electronic device 1 relative to the body according to changes in the light receiving pattern of reflected light in multiple regions of the light receiving unit 232. In this way, the wearing determination method can more accurately determine whether the electronic device 1 is fixedly attached to the user, and therefore can quickly stop light emission when the electronic device 1 is removed, or have the user adjust the fitting to ensure that the pulse is measured appropriately.

[0061] Furthermore, by installing and executing the program 131 relating to the above-described wearing determination method on a computer, it becomes possible to easily determine the wearing state of the electronic device 1. Therefore, even if the electronic device 1 does not have a hardware configuration relating to various types of wearing detection, the wearing state of the electronic device 1 on a target body part such as a wrist can be determined more accurately.

[0062] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the pulse sensor 23 may have other functions, particularly functions related to biometric measurement, such as a sensor capable of detecting oxygen saturation (SpO2).

[0063] In the above description, the emission wavelength is switched from green light to red light when switching to operation reception, but this is not limited to this. When red light cannot be emitted, the amount of green light emitted may be reduced. Furthermore, the emitted light is not limited to green and red. Any wavelength other than green may be used as long as it is usable for measuring pulse. Furthermore, any wavelength other than red, for example, blue light, may be emitted as long as it is usable for detecting movement.

[0064] In addition, although the above description has been given using the example of detecting the direction and speed of fingertip movement as an operation detection, either one of these may be used. Furthermore, the movement direction does not have to be limited to a linear direction. Curved or circular movements may also be detectable within the range that the light receiving unit 232 can identify. For example, a circular movement may be accepted as an operation having the same meaning as rotating the crown.

[0065] Furthermore, although the above-described removal detection process does not take into account whether infrared light is detected, this may be taken into account as in the past. That is, if the state in which the detection level of infrared light falls below a reference level continues for a reference time or longer, it may be determined that electronic device 1 has been removed from the wrist, regardless of whether the above-described relative movement has been detected.

[0066] In the above description, the movement direction detected when the light emission is stopped and when the light emission color is changed are different, but this is not limited to this. For example, two-stage detection control may be used, in which the light emission color is first changed when movement in a first direction is detected, and then light emission is stopped if no movement is detected again within a specified time. Furthermore, even if the first direction and the second direction are different, they do not have to be opposite directions.

[0067] In the above description, the illuminance sensor 22 is used to determine whether the electronic device 1 is in use, but this is not limiting. For example, if the electronic device 1 has a solar panel, the illuminance may be calculated according to the amount of power generated by the solar panel. Furthermore, a setting may be made to switch so that the illuminance sensor 22 does not determine whether the electronic device 1 is in use, for example, in areas where light is poor or at night.

[0068] In the above description, it is determined that the electronic device is worn loosely when a change in the light-receiving pattern by the light-receiving unit 232 is detected in correspondence with the detection of body movement by the acceleration sensor 21. However, this is not limited to this. For example, in an operation mode (predetermined mode) such as an activity mode in which the electronic device 1 measures the user's activity, particularly the state related to exercise, if a change in the light-receiving pattern by the light-receiving unit 232 is detected at a specific cycle, it may be determined that the electronic device is worn loosely. Furthermore, for example, when body movement is detected by the acceleration sensor 21, the operation mode may be changed to one that determines the wearing state, particularly whether or not the device is worn loosely. Furthermore, even if looseness is detected, a notification operation does not necessarily have to be performed. It may also be used to generate additional information indicating that the measurement result history may have low accuracy.

[0069] Furthermore, while the above embodiment utilizes the movement of a fingertip, the movement is not limited to relative movement relative to the fingertip as long as a change in the light-receiving pattern can be detected. For example, removal of the electronic device 1 may be detected by moving the electronic device 1 across a patterned desk surface. In this case, the electronic device 1 needs to be moved in the opposite direction to the movement of the fingertip relative to the fixed desk surface. Furthermore, the action of wiping the light entrance 42 with a cloth or the like may also be detected.

[0070] In the above description, the electronic device 1 is described as being an electronic wristwatch or a smartwatch, but is not limited to these. Any wearable device that performs measurements, particularly biometric measurements, using an optical sensor may be used.

[0071] In the above description, the storage unit 13 is described as being composed of a nonvolatile memory such as a flash memory as an example of a computer-readable medium for storing the program 131 related to removal detection of the present invention, but is not limited to this. Other computer-readable media may be used, such as other nonvolatile memories such as MRAM, HDDs (Hard Disk Drives), and portable recording media such as CD-ROMs and DVD discs. Furthermore, a carrier wave may also be used as a medium for providing data of the program related to the present invention via a communication line.

[0072] In addition, the specific configurations, contents and procedures of the processing operations, etc. shown in the above embodiments can be modified as appropriate without departing from the spirit of the present invention. The scope of the present invention includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0073] 1 electronic device, 11 CPU, 23 pulse sensor, 231 light emitting unit, 232 light receiving unit

Claims

1. an optical sensor including a light-emitting unit that emits light and outputs light, and a light-receiving unit that detects reflected light that is the light emitted by the light-emitting unit reflected by an incident surface in a plurality of areas arranged side by side; a processing unit that determines a state of attachment to the body in accordance with a change in a light receiving pattern of the reflected light in the plurality of regions; A wearable device comprising:

2. the light receiving unit is capable of detecting an amount of the reflected light received in each of the plurality of regions, the processing unit detects a change in the light-receiving pattern based on a change in the amount of the reflected light received in the plurality of regions. The wearable device according to claim 1 .

3. Equipped with an acceleration measurement unit, the processing unit detects a change in the light receiving pattern, and determines that the wearing state is loose when the change is detected in correspondence with the detection of the body movement by the acceleration measuring unit. The wearable device according to claim 1 .

4. The processing unit determines that the wearable device is loose when a change in the light-receiving pattern is detected at a predetermined cycle while the wearable device is set to a predetermined mode. The wearable device according to claim 1 .

5. An annunciation operation unit is provided, When the processing unit determines that the wearing state is loose, the processing unit causes the notifying operation unit to perform an notifying operation indicating that the wearing state is loose. The wearable device according to claim 3 or 4.

6. The wearable device according to claim 1 , wherein the processing unit stops the light emission by the light emitting unit when movement of the light receiving pattern in a first direction is detected.

7. the processing unit detects movement of the light-receiving pattern, identifies at least one of a direction and a speed of the movement of the light-receiving pattern, and accepts a request for an operation according to the identified result. The wearable device according to claim 6.

8. The wearable device of claim 7, wherein the processing unit detects movement of the light receiving pattern and identifies at least the direction of movement of the light receiving pattern, and when movement of the light receiving pattern in a second direction different from the first direction is detected, changes at least one of the amount and wavelength of light emitted by the light emitting unit, thereby enabling acceptance of the operation request.

9. A display operation unit is provided, The operation request includes a request to change the display content by the display operation unit. The wearable device according to claim 7.

10. A method for determining whether a wearable device is being worn, the method comprising: an optical sensor having a light-emitting unit that emits light and outputs light; and a light-receiving unit that detects, in a plurality of aligned regions, reflected light that is generated when the light emitted by the light-emitting unit is reflected on an incident surface, the reflected light comprising: determining a state of attachment to the body based on a change in a light-receiving pattern of the reflected light in the plurality of regions; Fitment determination method.

11. A computer of a wearable device equipped with an optical sensor having a light emitting unit that emits light and outputs light, and a light receiving unit that detects reflected light that is reflected from an incident surface of the light emitting unit in a plurality of areas arranged side by side. A determination means for determining the state of attachment to the body based on a change in the light reception pattern of the reflected light in the plurality of areas. A program that functions as a

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