JP2014238696A - Electronic apparatus and tap operation detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus, a tap operation detection method, and the like that perform appropriate detection processing of tap operation by setting a sampling frequency and a threshold value interlockingly.SOLUTION: An electronic apparatus includes: a setting unit 110 for setting a sampling frequency to detect acceleration at an acceleration sensor 10 and a threshold value for determining tap operation; and a processing unit 120 for determining tap operation on the basis of sensor information from the acceleration sensor. The setting unit 110 sets the sampling frequency to F1 and the threshold value to Th1 in a first setting mode of the acceleration sensor 10, and sets the sampling frequency to F2 higher than F1 and the threshold value to Th2 larger than Th1 in a second setting mode of the acceleration sensor 10.

Description

  The present invention relates to an electronic device, a tap operation detection method, and the like.

  There are various types of interfaces for the user to input to the electronic device. For example, the interface may be an operation unit having keys, buttons, or the like, or may be a touch panel also serving as a display unit. A technique using a tap operation (tap operation) as another input interface is also widely known. Here, the tap operation is an operation in which the user strikes the electronic device using his / her hand or the like, and in a broad sense, is an operation that gives an impact to the electronic device. The tap operation represents an operation input by the tap operation.

  The tap operation is a useful user interface in an electronic device where input devices such as buttons are limited. For example, a wristwatch-type electronic device is required to be small and light, or a simple configuration is required to realize an interface that is easy for the user to understand.

  However, in order to detect a tap operation, it is necessary to capture a very short change in acceleration. For example, if sampling of an acceleration signal is not performed with a resolution of about 200 Hz, the possibility of erroneous detection increases. However, if the resolution is made finer, power consumption increases accordingly. That is, accuracy and power consumption are inversely related, and it is very difficult to find a good balance between usability and device battery life.

  For example, Patent Literature 1 discloses a method of calculating an activity amount and changing the detection cycle of the acceleration sensor based on the calculated activity amount. In patent document 1, the effect of reducing the power consumption of an active mass meter by the said method is described.

JP 2006-288970 A

  The method of Patent Document 1 is intended to reduce the power consumption of the activity meter, and does not consider the detection of the tap operation using the acceleration sensor. As described above, in the tap operation, when the sampling frequency is lowered, the detection accuracy is lowered. That is, the sampling frequency in the tap operation should be set not only from the viewpoint of power consumption but also from the viewpoint of detection accuracy, but Patent Document 1 does not disclose this point. In particular, Patent Document 1 does not disclose such a technique, although an effect can be expected by setting an acceleration threshold value used for detecting a tap operation in conjunction with a sampling frequency.

  According to some aspects of the present invention, it is possible to provide an electronic device, a tap operation detection method, and the like that perform an appropriate detection process of a tap operation by setting the sampling frequency and the threshold in conjunction with each other.

  One aspect of the present invention includes a setting unit that sets a sampling frequency for acceleration detection of an acceleration sensor and a threshold value for determination of a tap operation, a processing unit that determines the tap operation based on sensor information from the acceleration sensor, The setting unit sets the sampling frequency to F1 and sets the threshold to Th1 in the first setting mode of the acceleration sensor, and sets the threshold to Th1 in the second setting mode of the acceleration sensor. The present invention relates to an electronic device that sets the sampling frequency to F2, which is a frequency higher than F1, and sets the threshold value to Th2, which is a value larger than Th1.

  In one embodiment of the present invention, when the acceleration sensor used for detecting the tap operation is set, when the sampling frequency is increased, the threshold value is also set to a large value. As a result, an appropriate threshold value can be set corresponding to the difference in waveform of the acceleration detection value accompanying the difference in sampling frequency, so that it is possible to set the acceleration sensor in consideration of the detection accuracy of the tap operation.

  Moreover, in one aspect of the present invention, a biological information detection sensor that detects biological information is included, and the processing unit receives from the biological information detection sensor based on body motion information that is the sensor information from the acceleration sensor. A correction process may be performed on the biological information, and the tap operation may be determined based on the sensor information from the acceleration sensor.

  This makes it possible to perform a tap operation detection process, a biological information noise reduction process, and the like using a common acceleration sensor.

  In the aspect of the invention, the setting unit may set the setting mode of the acceleration sensor to the second setting mode when it is determined that the user wearing the electronic device is in an exercise state. Also good.

  Thereby, when the user is in an exercise state, it is possible to set the second mode in which the sampling frequency is relatively high and the threshold is relatively large.

  In one aspect of the present invention, the setting unit sets the first setting mode in an information display mode for displaying information, and the second setting in an information input mode for accepting external information input. The mode may be set.

  Thereby, it becomes possible to use an appropriate setting mode for each of the information display mode and the information input mode.

  According to another aspect of the present invention, the display unit includes a display control unit that performs display control of information on the display unit, and the setting unit sets the acceleration sensor to the second setting mode corresponding to the information input mode. In this case, the processing unit determines the tap operation based on the sensor information from the acceleration sensor in which the sampling frequency is set to F2 and the threshold is set to Th2, and the display control unit When the tap operation is detected by the processing unit, the display control for changing the display image displayed on the display unit may be performed.

  Thereby, when a tap operation is detected in the information input mode, it is possible to perform a transition of a display image based on the tap operation.

  In one aspect of the present invention, the processing unit compares the signal value in the positive direction in the predetermined axis direction of the acceleration sensor with the threshold value Th + in the positive direction, and the acceleration sensor. The tap operation may be determined based on at least one of comparison processing of the signal value in the negative direction in the predetermined axis direction and the threshold value Th- in the negative direction. .

  Accordingly, it is possible to detect the tap operation based on the comparison process between the vertical movement of the waveform of the acceleration detection value by the tap operation and the set threshold value.

  In one aspect of the present invention, the electronic device includes a mounting determination unit that determines a mounting state of the electronic device, and the setting unit determines that the electronic device is in a non-wearing state by the mounting determination unit. The acceleration sensor may be set to a third setting mode in which the value of the sampling frequency is F0 that is a frequency lower than F1.

  Accordingly, when the electronic device is not attached, it is possible to set the third setting mode in which the sampling frequency is a lower frequency than the first setting mode.

  Another aspect of the present invention performs setting processing for setting a sampling frequency for acceleration detection of the acceleration sensor and a threshold value for determination of tap operation, and is based on sensor information from the acceleration sensor based on the set sampling frequency and the threshold value. In the first setting mode of the acceleration sensor, the sampling frequency is set to F1, and the threshold is set to Th1, as the setting process. In the second setting mode of the acceleration sensor, the sampling frequency is set to F2, which is a frequency higher than F1, and the threshold value is set to Th2, which is a value larger than Th1. To do.

Explanatory drawing of tap operation. 1 is a system configuration example of an electronic apparatus according to an embodiment. Example of setting the axis of the acceleration sensor. The structural example of a biometric information detection sensor. An example of body motion noise reduction processing using an adaptive filter. 6A to 6C show examples of a pulse wave detection signal, a body motion detection signal, and a waveform and a frequency spectrum of a signal after body motion noise reduction processing based on the pulse wave detection signal and the body motion detection signal. FIG. 7A shows an example of a waveform of an acceleration detection value, and FIG. 7B shows an example of a waveform representing a detection result of a tap operation based on the acceleration detection value. 8A and 8B are examples of operations in which the waveform of the acceleration detection value is similar to a tap operation. FIGS. 9A to 9C show waveform examples of acceleration detection values obtained by a tap operation at different sampling frequencies. FIGS. 10A to 10C are waveform examples of acceleration detection values obtained by wrist rotation operations at different sampling frequencies. FIG. 11A to FIG. 11C show examples of waveforms of acceleration detection values obtained by shaking the wrist at different sampling frequencies. 12A to 12C are waveform examples of acceleration detection values by a tap operation, a wrist rotation operation, and a wrist swing operation in a relatively short period. The figure explaining the difference in the acceleration detection value by sampling timing. 14A and 14B show examples of waveforms at a low sampling frequency. FIGS. 15A and 15B show examples of waveforms at a medium sampling frequency. 16A and 16B show examples of waveforms at a high sampling frequency. Specific examples of mode switching processing and screen transition.

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

1. First, the method of this embodiment will be described. There are various types of interfaces for the user to input to the electronic device. In electronic devices such as home appliances, buttons and keys that are physically provided are generally used. In recent years, a touch panel is often used as a user interface and is often used in electronic devices such as smartphones.

  However, in an electronic device whose size is restricted, it may be difficult to provide the above-described button, touch panel, or the like. For example, wristwatch-type electronic devices are often required to be smaller and lighter. In that case, a sufficient number of physical buttons cannot be provided, and the touch panel is also limited in area and does not become a useful interface.

  Furthermore, even if such an electronic device is provided with a physical button, it is difficult to present the functions of each button to the user in an easily understandable manner. For example, in the case of an electronic device such as a television, each button provided on the main unit or the remote controller is indicated by characters or a picture, such as whether the button is for power operation, playback operation, or volume adjustment. This allows the user to properly operate many buttons. On the other hand, in a wristwatch-type electronic device or the like, it is necessary to make the buttons themselves small, and when a plurality of buttons are provided, it is difficult to clearly indicate to the user what functions each has. As a solution to this, it is considered to realize an interface that is easy to understand for the user by reducing the number of buttons, but the types of operations that the user can perform are reduced.

  Therefore, a tap operation is useful. The tap operation is an operation of tapping an electronic device. For example, in the case of a wristwatch-type electronic device, the electronic device is tapped with a hand opposite to the hand wearing the electronic device as shown in FIG. It becomes operation. In addition, although the operation | movement which taps with a finger | toe is shown in FIG. 1, operation which taps an electronic device by other methods, such as using a palm, is also contained in tap operation.

  Since the tap operation detects that the device has been hit based on the sensor information of the acceleration sensor, it is not necessary to separately provide a structure for detecting the tap operation in the electronic device, and it can also be used in the above-described wristwatch-type electronic device and the like. Is possible.

  However, in order to detect a tap operation, it is necessary to detect a change in acceleration in a very short period. Although details will be described later, for example, as shown in FIG. 14B, it is necessary to detect the vertical movement of the acceleration signal waveform within 20 ms. According to the study conducted by the present applicant, it is known that a sampling frequency of about 200 Hz is required as a specific numerical value. In addition, as the sampling frequency is increased, the detection accuracy of the tap operation is improved. According to the study conducted by the present applicant, it is known that the false detection of the tap operation can be sufficiently reduced if the sampling frequency is about 1620 Hz. .

  In other words, within a certain numerical range, there is a merit that the detection accuracy of the tap operation is improved as the sampling frequency is increased, but there is also a demerit that the power consumption is increased. In particular, electronic devices that are useful for tapping operations are small and portable electronic devices as described above. Considering restrictions on battery capacity and the like, a large power consumption is a problem that cannot be ignored. . In other words, detection accuracy and power consumption are inversely related, and it is necessary to find a good balance between usability and device battery life.

  Patent Document 1 discloses a method of calculating an activity amount and changing the detection cycle of the acceleration sensor based on the calculated activity amount. However, the method of Patent Document 1 is intended to reduce the power consumption of the activity meter, and does not consider the detection of the tap operation using the acceleration sensor. As described above, in the tap operation, when the sampling frequency is lowered, the detection accuracy is lowered. In other words, the sampling frequency in the tap operation is set not only from the viewpoint of power consumption, but also from the viewpoint of detection accuracy, such as whether the detection status of the tap operation requires high accuracy or low accuracy is sufficient. However, Patent Document 1 does not disclose this point.

  Therefore, the present applicant proposes a method of appropriately controlling the detection accuracy of the tap operation and the power consumption required for detecting the tap operation by setting the sampling frequency in consideration of the possibility of the tap operation. Further, in conjunction with the sampling frequency, a threshold value used for detecting the tap operation is also set. By setting the threshold corresponding to the sampling frequency, tap operation detection processing suitable for each sampling frequency can be performed. Specifically, when the sampling frequency is high, the possibility that the acceleration detection value caused by other than the tap operation is erroneously detected as a tap operation is suppressed by increasing the threshold value. In addition, when the sampling frequency is low, the possibility of erroneous detection that the tap operation is performed but not the tap operation is suppressed by lowering the threshold value.

  In the following, a method for setting the sampling frequency using the operation information, the reception status of the communication unit, etc. as a trigger will be described. However, the present embodiment is not limited to this. The method of the present embodiment sets the sampling frequency and the threshold in association with each other, and any method can be applied to determine how the sampling frequency is determined.

  Hereinafter, a system configuration example of the electronic apparatus according to the present embodiment will be described, and then a tap operation detection method using an acceleration sensor will be described. Thereafter, an example of a sampling frequency setting method will be described, a method of setting a tap operation detection threshold in accordance with the setting of the sampling frequency will be described, and finally a specific example of this embodiment will be summarized.

2. System Configuration Example FIG. 2 shows a system configuration example of an electronic apparatus according to the present embodiment. As shown in FIG. 2, the electronic device includes an acceleration sensor 10, a biological information detection sensor 20, a setting unit 110, a processing unit 120, an operation information acquisition unit 130, an operation unit 140, a communication unit 150, A mounting determination unit 160, a display control unit 170, and a display unit 180 are included. However, the electronic apparatus is not limited to the configuration shown in FIG. 2, and various modifications such as omitting some of these components or adding other components are possible.

  The acceleration sensor 10 is a sensor that acquires information related to acceleration. The acceleration sensor 10 may be, for example, a three-axis acceleration sensor. More specifically, the acceleration sensor 10 is provided in a wristwatch-type electronic device, and the acceleration value on each of the X, Y, and Z axes shown in FIG. It may be a sensor that detects. A specific example of the acceleration detection value on a given axis is as will be described later with reference to FIG. However, the acceleration sensor 10 of the present embodiment is not limited to the one that directly outputs the value of FIG. 7A or the like, and is based on the value of FIG. 7A and the parameters set by the setting unit 110 described later. You may perform the detection process of a tap operation and output the result of the said detection process. Note that the result of the tap operation detection process may be a pulse waveform in which a signal rises at a timing corresponding to the detection timing, as shown in FIG. 7B, for example.

  The biological information detection sensor 20 may be, for example, a pulse wave sensor that detects a pulse wave signal, and more specifically, a photoelectric sensor or the like can be considered. The electronic device of the present embodiment may have not only a simple clock display function but also a function of detecting biological information such as a wearer's pulse wave information, and the biological information detection sensor 20 is used in such a case. It is done. In that case, the electronic device of the present embodiment corresponds to, for example, a pulse meter. When targeting an electronic device not intended for detection of biological information, the biological information detection sensor 20 can be omitted.

  FIG. 4 is an enlarged schematic view of a part including a biological information detection sensor in the electronic device. As shown in FIG. 4, the biological information detection sensor 20 includes an LED 21 that emits light, a photodiode (PD) 22 that receives reflected light when the irradiated light is reflected by the living body, and a living body. And a convex portion 23 serving as a contact portion. The living body information detection sensor 20 of the present embodiment has a convex portion 23 shown in FIG. 4 and efficiently applies pressure (pressing) to the living body. Here, it is known that when detecting pulse wave information, it is possible to improve the detection accuracy by adjusting the pressure representing the pressure on the living body in the vicinity of the pulse wave sensor. Although the convex part 23 of FIG. 4 is a structure which considered press adjustment, since the method regarding the said press adjustment differs from the main point of the method of this embodiment, detailed description is abbreviate | omitted.

  The setting unit 110 sets parameters in a tap operation detection process using the acceleration sensor 10 based on information from an operation information acquisition unit 130, a communication unit 150, a mounting determination unit 160, and the like, which will be described later. Specifically, the sampling frequency and threshold value of the acceleration signal are set. Details of the setting process in the setting unit 110 will be described later.

  The processing unit 120 performs various processes based on the sensor information from the acceleration sensor 10. Specifically, the processing unit 120 performs a tap operation detection process, a noise reduction process for biological information from the biological information detection sensor 20, and a mode switching process for switching the operation mode of the electronic device. It should be noted that the detection process of the tap operation does not prevent the comparison process between an acceleration signal value and a threshold value which will be described later. However, when the pulse signal as shown in FIG. 7B is output from the acceleration sensor 10 as described above, the comparison process with the threshold value is performed by the acceleration sensor 10, and thus the processing by the processing unit 120 is performed. Is a process for determining whether or not there is a pulse in the sensor information from the acceleration sensor 10.

  In addition, when the electronic device performs detection processing of biological information, it is known that sensor information (biological information detection signal) from the biological information detection sensor 20 includes body movement noise due to user's movement or the like. Yes. Therefore, the processing unit 120 may perform a process of reducing body movement noise from the biological information detection signal using the sensor information from the acceleration sensor 10 as the body movement detection signal. In this case, it is assumed that the sensor information from the acceleration sensor 10 is not FIG. 7B but a signal value shown in FIG. 7A.

  A specific example of noise reduction processing using an adaptive filter is shown in FIG. The sensor information (pulse wave detection signal in a narrow sense) acquired from the biological information detection sensor 20 includes a component caused by body movement in addition to a component caused by heartbeat. Among these components, components useful for the calculation of the pulse rate and the like are components caused by the heartbeat, and the components caused by body movement hinder the calculation. Therefore, the acceleration sensor 10 is used as a body motion sensor to acquire a signal (body motion detection signal) due to body motion, and a signal component (estimated body motion noise component and correlation) with the body motion detection signal from the pulse wave detection signal. Body motion noise included in the pulse wave detection signal is reduced. However, even if the body motion noise in the pulse wave detection signal and the body motion detection signal from the body motion sensor are signals resulting from the same body motion, the signal level is not necessarily the same. Therefore, the estimated body motion noise component is calculated by performing filter processing in which the filter coefficient is adaptively determined for the body motion detection signal, and the difference between the pulse wave detection signal and the estimated body motion noise component is calculated. To do.

  FIG. 6A to FIG. 6C illustrate the above processing in terms of a frequency spectrum. FIG. 6A shows the time-varying waveform of the signal at the top and the frequency spectrum at the bottom. FIG. 6A shows a pulse wave detection signal before body motion noise reduction. As shown in A1 and A2, two frequencies having large values appear in the spectrum. One of these is caused by heartbeat, and the other is caused by body movement. Note that although there are some frequencies that are higher than A1, they are not considered here because they are high frequency components corresponding to integer multiples of A1 and A2. Hereinafter, high-frequency components are also seen in FIGS. 6B and 6C, but are not considered here as well.

  On the other hand, FIG. 6B shows a body motion detection signal. If there is only one type of body motion that causes the body motion detection signal, a frequency having a large value as shown in B1. One appears. Here, the frequency of B1 corresponds to A2 in FIG. In such a case, the signal shown in FIG. 6C is obtained by taking the difference between the pulse wave detection signal and the estimated body motion noise component by the method shown in FIG. As apparent from the figure, pulse wave detection is performed by subtracting an estimated body motion noise component having a peak B1 due to body motion from a pulse wave detection signal having two peaks A1 and A2 due to heartbeat and body motion. The body motion component (corresponding to A2) in the signal is removed, and as a result, the peak C1 (frequency corresponds to A1) due to the heartbeat remains.

  The operation information acquisition unit 130 acquires operation information from the operation unit 140. The operation unit 140 represents a user interface such as a button, a key, or a touch panel, and the tap operation targeted in the present embodiment is not included in the operation by the operation unit 140. The operation information here is information indicating a user's operation on the operation unit 140. For example, the operation information may be information indicating which button is pressed, or an electronic information created based on a specific key operation. It may be a control signal that causes the device to execute specific control.

  The communication unit 150 performs information communication processing with other electronic devices and the like via a network. The network here may be wired or wireless. For example, when the electronic device of the present embodiment is a wristwatch type device, the wristwatch type device and a smartphone or the like may be connected via a network such as short-range wireless and operate in conjunction with each other while communicating information. Conceivable. The communication unit 150 serves as an interface at that time, and acquires, for example, information related to operation of the smartphone by the user, reception of information by the smartphone, and the like from the smartphone.

  The mounting determination unit 160 determines the mounting state of the electronic device and outputs the determination result to the setting unit 110. For example, as shown in FIG. 4, when the biological information detection sensor 20 having the photodiode 22 is included in the electronic device, the attachment determination may be performed based on the light amount detected by the photodiode 22. Normally, when detecting a pulse signal, the external light is blocked, or even if a small amount of external light is detected, the value is made small enough to cancel the reflected light and the transmitted light from the LED 21. To detect. However, this assumes the case where the biological information detection sensor 20 is used in close contact with the subject as shown in FIG. Therefore, for example, when the electronic device is in a non-wearing state, such as when the wristwatch type device is removed from the arm, external light is detected by the photodiode 22. And it is known that this external light is very strong light compared with the reflected light and transmitted light of light from LED21. In other words, the amount of light detected by the photodiode 22 is much larger in the non-wearing state than in the wearing state, and it is possible to make a wearing determination by paying attention to this point. However, other methods may be used for mounting determination, and various modifications can be made. As an example, an acceleration detection value from the acceleration sensor 10 may be used. For example, a large value due to walking or arm swinging is detected when worn, while values other than gravitational acceleration are hardly detected when left on a desk or the like when not worn. The attachment determination may be performed based on the difference.

  The display control unit 170 controls the display unit 180. The display unit 180 is for displaying various display screens, and can be realized by, for example, a liquid crystal display or an organic EL display. Note that the display unit 180 is not limited to the one included in the electronic device, and may be provided in another device connected to the electronic device such as a smartphone.

3. Next, a basic method for detecting a tap operation based on an acceleration detection value detected by the acceleration sensor 10 will be described. In the tap operation, a tapping operation as shown in FIG. 1 is performed, so that the acceleration sensor 10 detects an impact due to the operation.

  It has been found that the impact due to the tap operation is detected as the vertical movement of the signal waveform as shown in FIG. Therefore, in the present embodiment, the tap operation is detected based on the comparison process between the signal value in the downward direction and the threshold value, the comparison process between the signal value in the upward direction and the threshold value, or both comparison processes. In the following description, a downward signal value is used, but the same processing can be performed for an upward signal value. When both the upper and lower sides are used, the tap operation may be detected when a threshold value is exceeded in both of them, or the tap operation may be detected when at least one of the threshold values is exceeded.

3.1 Setting of Acceleration Sensor in Predetermined Axis Direction The waveform shown in FIG. 7A shows the change in signal value of the acceleration sensor 10 in the predetermined axis direction. Here, it is considered that the impact caused by the tap operation is detected most strongly on the axis in the direction in which the impact is applied. For example, as shown in FIG. 1, when the dial portion of the timepiece device is struck from above, a strong impact is applied to the axis extending through the dial portion from top to bottom. Therefore, the axis in the impact direction may be used as the axis for detecting the tap operation.

  For example, it is assumed that the acceleration sensor 10 detects at least triaxial acceleration, and the three axes are set in a direction as shown in FIG. 3 with respect to the timepiece device. In that case, since the impact is applied in the negative direction of the Z-axis, a change in the signal value of the Z-axis may be used. Specifically, the signal waveform on the Z-axis is shown in FIG. It is thought that it will become. However, the impact is not necessarily applied only in the negative direction of the Z-axis, and an acceleration detection value representing the impact may be acquired for the X-axis and the Y-axis. Therefore, the tap operation may be detected using not only the Z axis but also other axes. In this case, determination processing using the X axis, determination processing using the Y axis, and determination processing using the Z axis may be performed independently, and final detection determination may be performed based on the results. The determination processing may be performed by combining the values of the Y-axis and the Z-axis (for example, by generating a combined vector representing acceleration and using the magnitude of the combined vector).

  Further, the relationship between the direction of each axis of the acceleration sensor 10 and the electronic device is not necessarily the one shown in FIG. 3, but depends on the direction in which the acceleration sensor 10 is attached in the electronic device. In this case, none of the axes of the acceleration sensor 10 coincides with an axis that is assumed to be the direction of impact (in a narrow sense, an axis that penetrates the dial portion from top to bottom). There are various types of processing in this case. For example, using the values of the X-axis, Y-axis, and Z-axis, the acceleration value in the axis that is assumed to be the direction of the impact is calculated, and the determination processing is performed using the result of the calculation. Can be done. In this case, the three acceleration vectors represented by the respective values of the X axis, the Y axis, and the Z axis are combined to obtain one combined vector, and the magnitude of the projection vector obtained by projecting the combined vector in the direction of the impact. This corresponds to performing processing using the length. Alternatively, the determination process may be performed using the size of the combined vector as it is regardless of the direction of impact. Alternatively, as described above, the determination process may be performed independently for each axis, and the final determination process may be performed based on the result.

  The “predetermined axis direction of the acceleration sensor” in the present specification may be an axis direction specified by any of the various methods described above. For convenience, in the following description, it is assumed that the direction of the Z axis shown in FIG. 3 is the “predetermined axis direction of the acceleration sensor”, but is not limited thereto.

3.2 Judgment processing between tap operation and similar operation As shown in FIG. 7A, since a large acceleration change appears in the tap operation, the change may be detected. However, in addition to the tap operation, there is an operation in which a change in acceleration appears up and down. Specifically, it is an operation of rotating the wrist as shown in FIG. 8A or an operation of shaking the wrist as shown in FIG.

  FIGS. 9A to 9C show changes in the acceleration detection value of the tap operation at different sampling frequencies. Specific sampling frequencies are 200 Hz in FIG. 9A, 400 Hz in FIG. 9B, and 1620 Hz in FIG. 9C, and FIG. 10A to FIG. 10C and FIG. The same applies to FIG. 11C. 10A to 10C show changes in the acceleration detection value of the wrist rotation operation, and FIGS. 11A to 11C show changes in the acceleration detection value of the operation of shaking the wrist. is there. As can be seen from FIGS. 9 (A) to 11 (C), the acceleration detection value changes up and down in the same way. Therefore, in order to accurately detect the tap operation, the wrist rotation operation, the wrist It is necessary to appropriately distinguish the shaking operation from the tap operation.

  FIGS. 12A to 12C show acceleration changes in a relatively short period of each of the tap operation, the wrist rotation operation, and the wrist swing operation. The sampling frequency in FIGS. 12A to 12C is 400 Hz.

  FIG. 12A shows a waveform of the acceleration detection value by the tap operation, and it can be seen that the vertical movement of the acceleration is about −6 G to +5.7 G in the tap operation. Here, the acceleration value in the state where there is no tap operation is described as 0G. Further, as can be seen from the region surrounded by the dotted line in FIG. 12A, the acceleration change in one direction is about 10 to 13 ms long, and one cycle of the vertical movement is about 20 to 26 ms long. It becomes.

  In consideration of this point, when compared with the waveform change of the wrist rotation operation of FIG. 12B, the width of the vertical movement is relatively small in the wrist rotation operation, which is about −2.4 G to +1.9 G. In other words, a threshold value is provided between -6G and -2.4G when determining in the negative direction, and between + 1.9G and + 5.7G when determining in the positive direction. Based on the comparison processing, it can be said that the tap operation and the wrist rotation operation can be distinguished.

  On the other hand, when the tap operation is compared with the change in the waveform of the wrist swinging motion in FIG. 12C, the vertical movement width of the acceleration detection value is slightly larger in the tap operation, but the tap operation and the wrist rotation motion are The difference in value is small compared with the comparison of the above, and it is considered that it is difficult to distinguish with high accuracy by the determination by the threshold value. However, as can be seen from a comparison between FIG. 12A and FIG. 12C in which the horizontal axis (time) has the same scale, the movement of the wrist has a much longer waveform period than the tap operation. As described above, since the half period is about 10 to 13 ms in the tap operation, a value corresponding to the amplitude of the waveform can be obtained by using the signal value within 10 to 13 ms. On the other hand, in the operation of shaking the wrist, even if the signal value within 10 to 13 ms is used as shown in FIG. 12C, the change in the signal value during that period is very small, and the value corresponding to the amplitude is It cannot be acquired. In other words, by setting the waveform used for detecting the tap operation to 10 to 13 ms (in a broad sense, a given period set based on the period of the waveform of the tap operation), the tap operation and the operation of shaking the wrist are performed. It can be said that it can be properly distinguished.

  From the above, it is possible to detect a tap operation without being confused with a similar operation by appropriately setting a period and a threshold value used for detecting the tap operation.

3.3 Range of Sampling Frequency As described above, in order to distinguish a wrist operation from a motion of shaking a wrist, the waveform in a given period set based on the period of the waveform of the tap operation is processed. set to target. In that case, if the sampling frequency is set too low, there is a possibility that no signal value can be acquired within the period, and comparison processing with a threshold value cannot be performed in the first place. For example, when a sampling frequency of 100 Hz or less, which is a frequency corresponding to 10 ms, is used, and a target period of 10 ms is targeted, there is a possibility that no signal value may be acquired within the target period, which is inappropriate.

  Further, the range of the acceleration detection value in the tap operation of about −6G to + 5.7G described above with reference to FIG. 12A corresponds to the minimum value and the maximum value (or values close thereto) of the vertical movement of the waveform. Is. Therefore, when the sampling frequency is low and acceleration at the timing corresponding to the minimum value or the maximum value is not acquired as the acceleration detection value, the acceleration detection detected by the acceleration sensor 10 is compared with the acceleration inherent in the impact caused by the tap operation. The value will be small. For example, when the acceleration waveform inherent in the tap operation is as shown in FIG. 13, only one value can be acquired within 10 ms at the above-described sampling frequency of about 100 Hz. Therefore, a desired process can be performed if the timing indicated by t1 is the sampling timing, but if the timing such as t2 or t3 is the sampling timing, the acceleration detection value becomes small. As a result, the possibility that the acceleration detection value by the tap operation becomes smaller than about −2.4 G to +1.9 G which is the change width of the acceleration detection value of the wrist rotation operation cannot be denied. In the determination process using the threshold value, the tap operation cannot be detected.

  In other words, the detection accuracy of the tap operation depends on the possibility of sampling the peak of the signal waveform or a value close thereto, in other words, the detection accuracy of the tap operation improves as the sampling frequency is increased. That is none other than. Specific examples are shown in FIGS. 14A to 16B. FIG. 14A shows a waveform of an acceleration detection value by a tap operation when the sampling frequency is 200 Hz, and FIG. 14B is an enlarged view of a part of FIG. Similarly, FIGS. 15A and 15B are signal waveforms obtained by a tap operation at a sampling frequency of 400 Hz, and FIGS. 16A and 16B are 1620 Hz. In FIG. 14B and the like, 20 ms corresponding to one cycle is targeted, but the concept is the same even when ½ cycle is targeted.

  As shown in FIG. 14B, by using 200 Hz, which is expected to be sampled at about two points per mountain, as the sampling frequency, it is possible to detect a certain level of vertical movement of the signal value during the target period. It becomes. Specifically, the tap operation can be detected with an accuracy of about 70% by setting the sampling frequency to 200 Hz.

  In addition, as illustrated in FIG. 15B, by setting the sampling frequency to 400 Hz, it is possible to obtain more detailed changes in the signal waveform within the target period than in the case of 200 Hz. For this reason, it is possible to increase the possibility of acquiring a larger value than the case of 200 Hz for the absolute value of the acceleration detection value and the absolute value of the minimum value, and the possibility of erroneous detection in the determination using the comparison process with the threshold value. Can be suppressed. Specifically, the tap operation can be detected with an accuracy of about 80% by setting the sampling frequency to 400 Hz.

  Similarly, as shown in FIG. 16B, by setting the sampling frequency to 1620 Hz, a more detailed signal waveform can be acquired as compared with the case of 400 Hz. As shown in FIG. 16 (B), at the sampling frequency of 1620 Hz, it is possible to almost certainly obtain the peak value of the peak, and the value is shown in FIG. 12 (A) and FIG. 15 (B). Its absolute value is larger than the minimum and maximum values at 400 Hz. That is, the tap operation can be detected more reliably than in the case of 400 Hz, and specifically, the tap operation can be detected with an accuracy of about 100%.

4). Setting method of sampling frequency As described above, a tap operation can be detected by setting an appropriate processing target period (tap determination period in FIG. 7A) and a threshold, and the detection accuracy is determined by the sampling frequency. The higher it is, the higher it is. However, increasing the sampling frequency increases the power consumption of the acceleration sensor 10. For example, the current amount when the sampling frequency is 200 Hz is about 18 μA, but is 36 μA at 400 Hz and 100 μA at 1620 Hz.

  Therefore, in the present embodiment, the setting unit 110 sets the sampling frequency, and the acceleration sensor 10 is operated using the set sampling frequency. Specifically, the sampling frequency is increased in a scene where there is a high possibility that a tap operation will be performed, or where a detection of a tap operation with high accuracy is required. This is based on the idea that the tap operation is one of user interfaces, and the possibility of the tap operation and the required accuracy can be estimated from the use case of the electronic device. Hereinafter, more specific examples will be described.

4.1 Detection of Operation Information Acquisition or Reception by Communication Unit As a sampling frequency setting timing, the operation information acquisition unit 130 may acquire operation information or the communication unit 150 may receive information. .

  The case where the operation information is acquired is specifically a case where the operation unit 140 is operated by the user. The operation of the operation unit 140 includes pressing a button or key, touching the touch panel, or the like. These operations are generally less likely to be erroneous operations than tap operations. This is because the buttons and keys are assumed to be physically pressed and are provided in some areas of the electronic device. Since the default operation is performed, it is difficult to think about an erroneous operation. Regarding the touch panel, the possibility of touching a position different from the intended position cannot be denied, but at least an operation based on the user's visual recognition is expected. On the other hand, in the tap operation, which part of the electronic device is hit is not particularly limited. For this reason, the operation is performed in a situation where the electronic device of the wristwatch type is not visible, such as under the sleeve of clothes, or the operation is performed without looking at the electronic device. Can happen. In addition, unlike buttons and the like, there is a possibility that there are individual differences in operation methods (tap position, direction, strength, etc.), and even the same user may have differences in operation.

  For this reason, when performing a series of operations such as information input, it is possible to consider a use case in which a tap operation is not performed from the beginning, but an input by a key operation or the like is performed first, followed by a tap operation.

  For example, a wristwatch-type electronic device is likely to have a plurality of operation modes of an information display mode for displaying information such as a clock and an information input mode for inputting some information. In this case, information input in the information input mode is stored or used for some processing in the electronic device itself or another system. Therefore, it is not preferable that the operation mode transitions to the information input mode and inappropriate information is input even though the user does not intend to input information. In that case, switching of the operation mode from the information display mode to the information input mode is performed by operating the operation unit 140 with a low possibility of an erroneous operation, and a tap operation is used for information input after shifting to the information input mode. Good. In such a use case, it can be said that the tap operation is highly likely to be performed after the operation of the operation unit 140, and therefore, the sampling frequency may be set high.

  A specific example of mode switching is shown in FIG. The display screen shown by D1 in FIG. 17 corresponds to the information display mode, and here, information such as date, time, remaining battery level, and network environment is displayed. In the information display mode for displaying D1, when the operation information indicating that the key operation on the operation unit 140 has been received is acquired, the processing unit 120 switches the operation mode to the information input mode, and accordingly the display control unit 170 is switched. Displays an information input screen on the display unit 180. The information input screen here is, for example, the screen shown in D2a. In this example, information regarding the amount of meal is input as information regarding calorie intake. Since there are a plurality of input candidates such as “less”, “normal”, and “more” for the amount of meal, the tap operation is accepted in this phase in the example of FIG. 17 every time one tap operation is accepted. The meal amount in the selected state is transitioned, and the display screen is transitioned accordingly. For example, if the amount of meal is two, “small” and “large”, the screens of D2a and D2b may be displayed alternately each time a tap operation is performed, and if there are three or more meals For example, they may be displayed sequentially. In the example of FIG. 17, it is considered that an erroneous operation is not preferable for the determination operation (decision operation) of the meal amount, and the determination operation is performed by key input. That is, when acquisition of operation information is detected in the information input mode, a mode switching process to the information display mode is performed as indicated by D3 (same as D1).

  In addition, the electronic device may be operated in conjunction with another device such as a smartphone. For example, interlocking such as operating an electronic device using an operation unit of a smartphone or transferring some simple information among detailed information held by the smartphone to the electronic device and displaying it on the display unit 180 of the electronic device. Can be considered. More specifically, when a smartphone receives information such as an e-mail, the user can operate the electronic device to convert the e-mail simple information (information such as sender name, title, received date, etc.) or e-mail text to the electronic device. May be displayed. Alternatively, when the smartphone detects an incoming call, the ringing tone may be stopped by operating the electronic device.

  In such a case, some information from the smartphone, such as information indicating reception of an e-mail or an incoming call, is received by the communication unit 150 of the electronic device. In other words, the reception of information at the communication unit 150 indicates that there is a high possibility that a tap operation will be performed thereafter, as in the case of the operation information acquisition at the operation information acquisition unit 130. When the reception of information is detected, the sampling frequency may be set high. In particular, in consideration of the ring tone stoppage described above, a quicker operation is required, so there is a high possibility of a tap operation that can be easily performed compared to a key operation or the like, and there is an advantage of increasing the sampling frequency. It can be said that it is big.

  Note that the sampling frequency may be increased by acquiring operation information or receiving information by the communication unit 150 within a predetermined period. In this way, it is possible to suppress an increase in power consumption due to a high sampling frequency for a long time. Further, when the acquisition of operation information or the reception of information is newly detected during the predetermined period, the predetermined period may be set again with the detection timing as a starting point. In this way, it is possible to prevent the sampling frequency from returning to a low state despite the high possibility that a tap operation will be performed.

4.2 Discrimination of wearing state The sampling frequency may be set based on the wearing state of the electronic device by the user. As described above, the mounting determination unit 160 can determine whether the electronic device is in a mounted state or a non-mounted state by using the detection value of the photodiode 22 or the acceleration detection value of the acceleration sensor 10.

  If it is a wristwatch-type electronic device, the operation with respect to the electronic device is likely to be performed in the mounted state, and if it is not mounted, the possibility of the operation is low. In particular, the tap operation is preferably performed in a situation where the impact is sufficiently transmitted as if the electronic device is fixed to the arm or the like, because the impact due to the tap is detected using the acceleration sensor 10, and is held by the hand. It is difficult to assume a tap operation on the electronic devices or electronic devices placed on the desk.

  Therefore, when the electronic device is not attached, the sampling frequency may be set lower than that when the electronic device is attached. It should be noted that the sampling frequency in the non-wearing state does not prevent the tap operation from being detected with a certain degree of accuracy, such as 200 Hz. For example, the frequency may be set to 200 Hz, which is 400 Hz or 1620 Hz in the mounted state. However, as described above, since it is difficult to detect the tap operation in the non-wearing state, the tap operation detection process itself may not be performed. In other words, the sampling frequency in the non-wearing state may be a frequency at which sufficient detection accuracy cannot be obtained, for example, lower than 200 Hz, and this makes it possible to further reduce power consumption. Become.

4.3 Modification The setting timing of the sampling frequency is not limited to that described above. For example, when a tap operation is detected in a state where the sampling frequency is low, the sampling frequency may be increased for a predetermined period (in the narrow sense, it is set to a maximum frequency such as 1620 Hz).

  This is useful, for example, when detecting a double tap operation. The double-tap operation is performed twice in a short period of time, similar to the double-click on the mouse. The double-tap operation is interpreted as one user input and is different from the single-tap operation. It is something to handle. If a double tap operation is allowed, there is a possibility that the tap operation will be performed again immediately after a single tap operation. Therefore, a higher sampling frequency may be set to detect the second tap operation. . In particular, according to the data analysis of the present applicant, it has been found that the acceleration detection value in the second tap operation of the double tap operation is smaller than the acceleration detection value of the first tap operation or the single tap operation. Therefore, since the possibility of erroneous determination is increased in the tap operation detection process that is a comparison process with the threshold value, it is desirable to increase the sampling frequency in order to ensure sufficient detection accuracy.

  Further, the user's behavior analysis may be performed, and the sampling frequency may be set based on the result of the behavior analysis. Specifically, when it is determined that the user is in an exercise state, the sampling frequency is set higher than in the case where it is determined that the user is in a non-exercise state.

  In the motion state, the acceleration due to the motion is included in the acceleration detection value of the acceleration sensor 10, the ratio of the signal value of the impact due to the tap operation in the acceleration detection value is reduced, and the detection accuracy of the tap operation is also reduced. . Therefore, it is desirable to increase the detection accuracy by setting the sampling frequency high in the exercise state.

  As an example of the determination method of the exercise state, the acceleration detection value of the acceleration sensor 10 may be used, and the exercise state may be determined when the acceleration detection value is larger than normal. Alternatively, since the movement has periodicity in walking, running, etc., the acceleration detection value also has a given periodicity. That is, it may be determined whether or not the exercise state is based on the presence or absence of periodicity of the acceleration detection value. Various methods are known for analyzing the user's behavior, and any method can be applied in the present embodiment, and thus further detailed description is omitted.

5. In the above description, the setting unit 110 sets the sampling frequency. However, the present invention is not limited to this. The setting unit 110 changes the sampling frequency and performs setting to change the tap operation detection threshold in conjunction with the sampling frequency.

  Specifically, the setting unit 110 performs setting such that the threshold value increases as the sampling frequency increases. For example, when the sampling frequency is changed from F1 to F2 (> F1), the threshold is also set from Th1 to Th2 (> Th1).

  As described above, in order to appropriately detect the tap operation, it is necessary to perform a discrimination process from the wrist rotation operation. In addition, acceleration due to motion or the like may be included as noise in the acceleration detection value. In the present embodiment, the acceleration detection value by the tap operation is larger than the upper limit of the acceleration detection value assumed as the wrist rotation operation or noise based on the idea that the acceleration detection value by the wrist rotation operation or noise is larger. Set the value as a threshold. As for the negative acceleration detection value, a value smaller than the lower limit of the acceleration detection value assumed as wrist rotation or noise is set as a threshold value. It is possible to think in the same way.

  In the example of FIG. 12B, since the absolute value of the acceleration detection value in the negative direction assumed in the rotation operation is about 2.4G, a value larger than that is set as a threshold and detected. When the absolute value of the acceleration detection value is larger than the threshold value, it is determined that a tap operation has been detected. However, it is unlikely that the same movement will always be performed for the wrist, and the acceleration detection value will be different for each movement. Therefore, it is difficult to clearly determine the upper limit of the absolute value of the detected acceleration value of the rotational motion. Therefore, it is desirable that the threshold is set with a certain margin with respect to a value assumed as an acceleration detection value by an operation other than the tap operation. In the example of FIG. 12B, if a threshold value of 2.5G is set, an acceleration detection value having a larger absolute value may appear depending on the rotation operation. In that case, the rotation operation is performed. Will be erroneously detected as a tap operation. That is, it can be said that the larger the absolute value of the threshold is, the better, from the viewpoint of suppressing the possibility of erroneously detecting an operation other than the tap operation as a tap operation. For example, if the threshold value is about 4.0 G, the possibility of erroneous detection that the rotation operation is a tap operation can be sufficiently reduced.

  However, as described above with reference to FIGS. 14A to 16B, the lower the sampling frequency, the higher the possibility that the value of the peak of the peak in the waveform cannot be detected, resulting in a smaller acceleration detection value. The possibility of becoming will increase. For this reason, if the absolute value of the threshold value is too large, the acceleration detection value cannot exceed the set threshold value in spite of the tap operation, that is, the tap operation is erroneous but not the tap operation. There is a risk of detection.

  In view of the above points, as long as the acceleration detection value tends to change according to the sampling frequency, the threshold value is dynamically changed according to the sampling frequency instead of setting the same threshold value at all sampling frequencies. It can be said that it is preferable to do.

  For example, when the sampling frequency is a sufficiently high frequency such as 1620 Hz, it is considered that the acceleration detection value by the tap operation is sufficiently large, and the threshold value is also set to a high value. In this way, it is possible to suppress the possibility of erroneously detecting an operation other than a tap operation such as a rotation operation or noise as a tap operation. For example, what is necessary is just to set the value shown to Th3 + of FIG. 16 (B), or Th3- as a threshold value.

  On the other hand, when the sampling frequency is a low frequency such as 200 Hz, the threshold value is small compared to the case where the sampling frequency is high in order to suppress the possibility of misdetection that the tap operation is not a tap operation. Set to value. In this case, compared with 1620 Hz or the like, there is a higher possibility that an operation other than the tap operation is erroneously detected as a tap operation, but this point is allowed. This is because the situation in which the tap operation is not recognized by the electronic device even though the user performs the tap operation with a clear intention is not preferable because it causes great stress to the user. is there. For example, as shown in FIG. 14B, Th1 + or Th1- having an absolute value smaller than Th3 + or Th3- may be set as the threshold value.

  Since it is assumed that the acceleration detection value is also an intermediate value at an intermediate sampling frequency such as 400 Hz, the threshold value satisfies Th1 + <Th2 + <Th3 + as shown in FIG. 15B. Th2 + or Th2- satisfying | Th1- | <| Th2- | <| Th3- | may be used.

6). Specific Example of the Present Embodiment In the present embodiment described above, as shown in FIG. 2, the electronic apparatus sets the acceleration detection sampling frequency of the acceleration sensor 10 and the tap operation determination threshold, and the acceleration sensor. 10 includes a processing unit 120 that determines a tap operation based on the sensor information from 10. The setting unit 110 sets the sampling frequency to F1 and sets the threshold to Th1 in the first setting mode of the acceleration sensor 10, and sets the sampling frequency to F1 in the second setting mode of the acceleration sensor 10. Is set to F2, which is a higher frequency, and the threshold is set to Th2, which is a value larger than Th1.

  Here, the threshold value for determining the tap operation is a value used for the comparison process with the peak value of the acceleration detection value, as shown in FIG. 7A, Th1 + in FIG. 14B, and the like. As described above, the tap operation detection process may use a downward change in the waveform, an upward change, or both. In this case, if the reference value of the waveform (the center of the vertical axis in FIG. 7 etc.) is 0G, the acceleration detection value in the upward direction is a positive value, and the acceleration detection value in the downward direction is a negative value. However, the magnitude of the threshold value here can be considered as the magnitude of the fluctuation range with respect to the reference value. That is, the threshold value having a larger difference from the reference value may be considered to be larger, and as described above, if the waveform reference value is 0 G, the threshold value of this embodiment can be considered using the absolute value of the acceleration detection value. That's fine.

  Thereby, it becomes possible to set a threshold appropriately according to the sampling frequency. Specifically, as shown in FIG. 16B, if the sampling frequency is high and the waveform of the acceleration detection value accurately reflects the acceleration waveform due to the impact of the tap operation, the threshold can be set large. The possibility of erroneously detecting an operation other than the tap operation as a tap operation can be suppressed. Conversely, as shown in FIG. 14B, when the waveform of the acceleration detection value is rough with respect to the acceleration waveform due to the impact of the tap operation, the tap operation is performed because the threshold can be set low. This suppresses the possibility of false detections that are not tapping operations.

  The electronic device may include a biological information detection sensor 20 that detects biological information as shown in FIG. Then, the processing unit 120 performs a correction process on the biological information from the biological information detection sensor 20 based on the body motion information that is sensor information from the acceleration sensor 10, and based on the sensor information from the acceleration sensor 10, Determine the tap operation.

  As a result, the acceleration sensor 10 can be commonly used for both body motion noise reduction processing and tap operation detection processing. It is known that sensor information of the biological information detection sensor 20 (pulse wave sensor in a narrow sense) includes body movement noise caused by a user's exercise or the like. Therefore, in an electronic device that detects biological information such as a pulse meter, it is common to perform noise reduction processing based on sensor information of a body motion sensor as described above with reference to FIGS. Further, as described above, the tap operation is a useful interface in an electronic device such as a wristwatch type device. That is, even in an arm-mounted pulse meter or the like, the tap operation is useful, but the tap operation can be detected using the acceleration sensor 10 as shown in the signal waveform of FIG. From the above, by applying the method of the present embodiment to an electronic device such as a pulse meter, it is possible to realize appropriate detection of a tap operation and removal of body motion noise from biological information by the common acceleration sensor 10. , Space saving and cost reduction can be realized.

  The setting unit 110 may set the setting mode of the acceleration sensor 10 to the second setting mode when it is determined that the user wearing the electronic device is in an exercise state.

  Thereby, when it is determined that the user is in an exercise state, the sampling frequency and the threshold can be set high. In the exercise state, the sensor information from the acceleration sensor 10 includes noise due to the exercise. However, since the threshold can be set high as shown in FIG. 16B, the noise is caused by the noise and the tap operation. It is possible to accurately determine the acceleration detection value.

  The setting unit 110 may set the first setting mode in the information display mode in which information is displayed, and may set the second setting mode in the information input mode that accepts input of information from the outside.

  Thereby, in the information display mode and the information input mode, it is possible to set the sampling frequency and threshold value suitable for each mode. As in the use case shown in FIG. 17, it is sufficiently conceivable that the information input mode is more likely to be tapped than the information display mode. Therefore, in the information input mode, the tap operation can be detected with high accuracy by using the second setting mode. On the other hand, in the information display mode in which the possibility of a tap operation is relatively low, the power consumption can be reduced by setting the first setting mode with a low sampling frequency.

  In addition, as illustrated in FIG. 2, the electronic device may include a display control unit 170 that performs display control of information on the display unit 180. Then, when the acceleration sensor 10 is set to the second setting mode corresponding to the information input mode by the setting unit 110, the processing unit 120 determines that the sampling frequency is set to F2 and the threshold is set to Th2. Based on the sensor information from the sensor 10, the tap operation is determined, and the display control unit 170 transitions the display image displayed on the display unit 180 when the processing unit 120 detects the tap operation. I do.

  Accordingly, it is possible to use the tap operation for the screen transition and to set the second setting mode with a high sampling frequency in order to detect the tap operation with high accuracy. In a wristwatch type device or the like, since the area of the display unit 180 is often limited, it is not realistic to include a lot of information in one display image. As a result, it is considered natural to present information by preparing a plurality of display images as shown in the meal amount input screen of FIG. 17 and transitioning the screen between them. Since the electronic device assumed in this embodiment has a limited number of buttons and keys, the types of operations that can be input are limited, and a transition from a given display screen to any other display screen is performed. Such complicated operations are difficult. Therefore, as shown in FIG. 17, the screen transition is such that a display image arranged in order is selected and displayed one by one from the top, and a plurality of operations are required until a desired screen is displayed. It is likely to be required. That is, in the information input mode, it is preferable to realize an interface that assumes a plurality of operations by the user, and from this point of view, it can be said that the possibility of a tap operation that can be easily operated is sufficiently high.

  Further, the processing unit 120 has a signal value in the positive direction in the predetermined axis direction of the acceleration sensor 10 (upward in a narrow sense if the Z axis shown in FIG. 3 is considered) and a threshold value Th + that is a threshold value in the positive direction. , A signal value in the negative direction in the predetermined axis direction of the acceleration sensor (downwardly in a narrow sense if the Z axis shown in FIG. 3 is considered), and a threshold value Th− The tap operation may be determined based on at least one of the comparison processes.

  Accordingly, as described above with reference to FIG. 7A and the like, it is possible to determine the tap operation based on the comparison process between the vertical movement of the acceleration detection value and the threshold value. In addition, although it described separately in Th + and Th- here, it is not necessary to set two types of threshold values. For example, since the threshold value may be information corresponding to an absolute value as described above, one threshold value Th that is a positive value is set, and the signal value in the positive direction is compared with Th. The negative signal value may be compared with -Th (or a comparison process between the absolute value of the negative signal value and Th). However, as described above with reference to FIG. 12A, when comparing acceleration detection values in the positive and negative directions, the negative direction value corresponding to the impact direction of the tap operation is greater in the impact direction. In many cases, the value is slightly larger than the value in the positive direction corresponding to the opposite direction. Considering this difference, different threshold values may be set in the positive direction and the negative direction.

  Further, as shown in FIG. 2, the electronic device may include a mounting determination unit 160 that determines a mounting state of the electronic device. Then, when the mounting determination unit 160 determines that the electronic device is not mounted, the setting unit 110 sets the acceleration sensor 10 to a third sampling frequency F0 that is a frequency lower than F1. Set to setting mode.

  Thereby, the sampling frequency can be set based on the determination result of the mounting state of the electronic device. The non-wearing state corresponds to a state in which the belt is removed, for example, in the case of a wristwatch type electronic device. Therefore, the state in which the belt is removed with the user's hand held is also a non-wearing state, and the state in which the belt is completely separated from the user's hand and left on the desk is also a non-wearing state. . In any case, since it is difficult to detect the impact caused by the user's tap operation by the acceleration sensor 10 in the non-wearing state, it may be determined that the possibility of the tap operation is low, and the sampling frequency is also set low.

  The reason why the acceleration sensor 10 is set to the third setting mode in the non-wearing state is assumed to be the first setting mode in the information display mode and the second setting mode in the information input mode, for example. Is. In the information display mode, although the possibility of a tap operation is lower than that in the information input mode, it cannot be completely stated that there is no tap operation. For example, in the first setting mode, it is preferable to secure a detection accuracy of about 70% with a sampling frequency of about 200 Hz. On the other hand, in the non-wearing state, as described above, even if the tap operation cannot be detected at all, the problem is not so great that the sampling frequency as high as the information display mode is not required. That is, since a sampling frequency smaller than 200 Hz may be used, the third setting mode different from the first setting mode is set in the non-wearing state. In this case, since the detection of the tap operation is not necessary in the first place, the threshold for detecting the tap operation need not be set.

10 acceleration sensor, 20 biological information detection sensor, 21 LED,
22 photodiodes, 23 convex parts, 110 setting parts, 120 processing parts,
130 operation information acquisition unit, 140 operation unit, 150 communication unit, 160 wearing determination unit,
170 display control unit, 180 display unit

Claims (8)

A setting unit for setting a sampling frequency for acceleration detection of the acceleration sensor and a threshold value for determining a tap operation;
A processing unit that determines the tap operation based on sensor information from the acceleration sensor;
Including
The setting unit
In the first setting mode of the acceleration sensor, the sampling frequency is set to F1, the threshold is set to Th1,
In the second setting mode of the acceleration sensor, the sampling frequency is set to F2, which is a frequency higher than F1, and the threshold is set to Th2, which is a value larger than Th1. In claim 1,
Including a biological information detection sensor for detecting biological information,
The processor is
Based on body motion information that is the sensor information from the acceleration sensor, while performing correction processing for the biological information from the biological information detection sensor,
An electronic device, wherein the tap operation is determined based on the sensor information from the acceleration sensor. In claim 1 or 2,
The setting unit
An electronic device, wherein when it is determined that a user wearing the electronic device is in an exercise state, the setting mode of the acceleration sensor is set to the second setting mode. In any one of Claims 1 thru | or 3,
The setting unit
The electronic device is set to the first setting mode in an information display mode for displaying information, and is set to the second setting mode in an information input mode for receiving input of information from the outside. In claim 4,
Including a display control unit that performs display control of information in the display unit,
When the acceleration sensor is set to the second setting mode corresponding to the information input mode by the setting unit,
The processor is
The tap operation is determined based on the sensor information from the acceleration sensor in which the sampling frequency is set to F2 and the threshold is set to Th2.
The display control unit
An electronic apparatus that performs the display control for transitioning a display image displayed on the display unit when the tap operation is detected by the processing unit. In any one of Claims 1 thru | or 5,
The processor is
Comparison processing between a positive signal value in the predetermined axis direction of the acceleration sensor and the threshold value Th + in the positive direction, and the negative signal value in the predetermined axis direction of the acceleration sensor The electronic device is characterized in that the tap operation is determined based on at least one of comparison processes with Th- which is the threshold value in the negative direction. In any one of Claims 1 thru | or 6.
Including a mounting determination unit that determines a mounting state of the electronic device;
The setting unit
When the mounting determination unit determines that the electronic device is not mounted, the acceleration sensor is set to a third setting mode in which the value of the sampling frequency is F0 which is a frequency lower than F1. An electronic device characterized by that. Perform the setting process to set the acceleration detection sampling frequency of the acceleration sensor and the threshold for tap operation determination,
Based on the sensor information from the acceleration sensor by the set sampling frequency and the threshold value, performing a tap determination process for determining the tap operation,
As the setting process,
In the first setting mode of the acceleration sensor, the sampling frequency is set to F1, the threshold is set to Th1,
In the second setting mode of the acceleration sensor, the sampling frequency is set to F2, which is a frequency higher than F1, and the threshold is set to Th2, which is a value larger than Th1. Tap operation detection method.

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