JP2017072943A - Detection device and detection program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device that can detect a grasping state while making surrounding people including a user not aware of it.SOLUTION: A detection device (2) comprises a piezoelectric element (10) that generates the ultrasound propagating through a cabinet (1) which can be grasped by a user, and a grasp detection unit (20) that detects whether the user grasps the cabinet from an attenuation factor of a reflection wave of the incident wave generating from the piezoelectric element and entering the cabinet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection device that detects that a user is holding a casing, and a detection program.

  In a device (for example, a mobile phone) that allows the user to grip the casing, it is detected whether the user has gripped the casing, and the state in which the user grips the casing (gripping state) is detected. Various processes are performed as an opportunity. For example, Patent Document 1 discloses a technique that uses vibration sound generated when a mobile phone is vibrated as means for detecting a gripping state.

JP 2014-103545 A (published June 5, 2014)

  However, since the conventional technology as described above vibrates the housing using the vibration function that is generally provided in mobile phones, vibration sounds may reverberate around the user and may cause discomfort. There is a problem. In addition, when the vibration function is stopped, there is a problem that the gripping state cannot be detected.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a detection device that can realize detection of a gripping state without being conscious of surroundings including a user.

  In order to solve the above problems, a detection device according to an aspect of the present invention is provided in a housing that can be held by a user, an ultrasonic wave generation unit that generates an ultrasonic wave that propagates through the housing, and the ultrasonic wave A grip detection unit that detects whether or not the user is gripping the housing from the attenuation rate of the reflected wave with respect to the incident wave that is generated from the generation unit and is incident on the housing.

  The detection device according to one embodiment of the present invention has an effect that the detection of the grip state can be realized without the surroundings including the user being conscious.

It is a block diagram of the detection apparatus which concerns on Embodiment 1 of this invention. (A) is a figure which shows schematic structure of the smart phone provided with the detection apparatus shown in FIG. 1, (b) is a wave form diagram which shows each signal in the detection apparatus with which the smart phone shown to (a) was equipped. is there. (A) is a flowchart which shows the flow of the calibration process in the detection apparatus shown in FIG. 1, (b) is a flowchart which shows the flow of the ultrasonic detection process in the detection apparatus shown in FIG. It is a flowchart which shows the flow of the holding | grip state detection process in the detection apparatus shown in FIG. (A) is a figure which shows schematic structure of the smart phone provided with the detection apparatus which concerns on Embodiment 2 of this invention, (b) is each signal in the detection apparatus with which the smart phone shown to (a) was equipped. FIG. (A) shows the schematic structure of the smart phone provided with the detection apparatus which concerns on Embodiment 3 of this invention, (b) is a figure which shows schematic structure of the modification of the smart phone shown to (a). (A) is a schematic diagram showing that one piezoelectric element is replaced with two of a transmitting piezoelectric element and a receiving piezoelectric element, and (b) to (e) are FIGS. FIG. 7 is a diagram showing a schematic configuration showing an example in which the piezoelectric element is replaced with two of a transmitting piezoelectric element and a receiving piezoelectric element in each of the smartphones shown in (a) and (a) and (b) of FIG. 6.

Embodiment 1
Embodiment 1 of the present invention will be described in detail with reference to FIGS. In the present embodiment, an example will be described in which the detection device of the present invention is mounted on a smartphone having a housing that can be held by a user. The same applies to the following embodiments.

(Smartphone overview)
First, the outline | summary of the smart phone 101 is demonstrated based on Fig.2 (a). The smartphone 101 includes a housing 1 that can be gripped by a user, and a detection device 2 that is provided inside the housing 1 and detects a gripping state of the housing 1 by the user. Here, the thickness (hereinafter referred to as “cavity thickness”) d1 in the gripping direction (horizontal direction in the figure) of the housing 1 is assumed.

  The detection device 2 includes two piezoelectric elements (ultrasonic wave generation units) 10 that generate ultrasonic waves that propagate through the housing 1 and a grip detection unit 20 that detects that the user is gripping the housing 1. It is out. The two piezoelectric elements 10 are arranged so as to face each other in the horizontal direction of the position of the interior 1a of the housing 1 that faces the position of the surface of the housing 1 that the user's hand 3 will hold. The piezoelectric element 10 generates an ultrasonic wave propagating through the casing 1 having a cabinet thickness d1 as an output pulse, and receives a reflected wave reflected from the surface of the casing 1 as a reflected pulse. This reflected pulse is attenuated compared to the output pulse. In addition, the piezoelectric element 10 used in the present embodiment serves both as a transmitting element that generates electricity by receiving electricity and a receiving element that receives electricity and generates electricity. In the detection device 2, an ultrasonic incident wave driving wave is generated in each piezoelectric element 10 by the grip detection unit 20 and transmitted to the housing 1, and the reflected ultrasonic wave reflected from the housing 1 is received. Then, it is detected whether the user is holding the casing 1 from the attenuation rate of the reflected wave with respect to the incident wave of the ultrasonic wave. The attenuation factor is a value indicating how much the signal intensity of the reflected wave is reduced with respect to the signal intensity of the incident wave. Therefore, if the signal intensity of the incident wave is 100 and the signal intensity of the reflected wave is 50, the attenuation rate is 50%. Here, the amplitude (signal intensity) of the reflected wave with respect to the driving wave is 0% to 10% if the surface of the housing 1 is in contact with the air, and is 0% if it is a human body (hand). 50-99%. In other words, if the air that is in contact with the surface of the casing 1 is air, the reflected wave is hardly attenuated. If the human body (hand) is in contact with the surface of the housing 1, the reflected wave is It will be greatly attenuated.

  FIG. 2B shows waveform diagrams of various signals when the detection apparatus 2 shown in FIG. 2A performs the detection operation. Here, the grip detection unit 20 detects the grip state by comparing the amplitude (signal intensity) of the reflected waveform (detected waveform) with respect to the drive waveform as shown in FIG. For example, as shown in FIG. 2B, the amplitude of the drive waveform is A1, the amplitude of the reflected waveform (detected waveform) in the non-gripping state is A2, and the amplitude of the reflected waveform (detected waveform) in the gripped state is A3. In this case, A1> A2> A3 holds.

  The reflected wave will be described using a specific example. When the case 1 is made of polymethyl methacrylate resin (PMMA), the cavity thickness d1 is 2 mm, and the ultrasonic frequency is 9.5 MHz, the velocity of the ultrasonic wave propagating in the case 1 Is 2680 m / s, the time required for the ultrasonic wave to reciprocate through the cavity thickness d1 between the surface of the piezoelectric element 10 and the surface of the housing 1 is 1.5 μs, and the wavelength is 0.1 μs. . Therefore, the ultrasonic wave received on the surface of the piezoelectric element 10 within 1.5 μs after the generation of the driving wave is used as a reflected wave for detecting the gripping state.

(Details of grip detection unit)
Next, the grip detection unit 20 will be described in detail. FIG. 1 is a schematic block diagram of the grip detection unit 20.

  The grip detection unit 20 includes a drive waveform generator 21, an amplifier 22, an amplifier input unit 23, a reflected pulse amplitude comparison unit 24, and a storage unit 25.

  The drive waveform generator 21 generates electricity for the piezoelectric element 10 to generate ultrasonic waves, and the amplifier 22 amplifies electricity. The amplifier input unit 23 performs input to the amplifier 22 at an appropriate timing in order to selectively acquire a reflected wave received by the piezoelectric element 10 and used for detection of a gripping state. The comparison unit 24 compares the amplitude of the driving wave waveform (driving waveform) generated by the driving waveform generator 21 and the reflected wave when the piezoelectric element 10 receives the ultrasonic wave reflected from the surface of the housing 1. The amplitude of the waveform (detected waveform) is compared. The storage unit 25 stores amplitude information and the like in the non-gripping state necessary when the reflected pulse amplitude comparison unit 24 verifies the attenuation rate of the reflected wave.

(Holding state detection process)
In the detection apparatus 2 in the present embodiment, in order to appropriately detect the gripping state by the gripping detection unit 20, (1) calibration processing, (2) ultrasonic detection processing, and (3) gripping state detection processing are performed.

(1) Calibration Process Details of the calibration process will be described with reference to the flowchart shown in FIG. This calibration process is performed by executing a calibration application on the smartphone 101. Therefore, first, when a calibration application is executed by the user, the smartphone 101 displays an initial message indicating the start of calibration on a display unit (not shown) (S1), and obtains a reference value when not gripped. Waiting for acceptance of the start operation (S2). As an initial message, for example, when “Please touch the screen after placing the smartphone on the desk” is displayed, the acceptance of the reference value acquisition start operation when not gripping is accepted by the user on the smartphone screen It will be. That is, the user's operation according to the initial message is an acceptance of the reference value acquisition start operation when not gripping.

  When a reference value acquisition start operation at the time of non-gripping is received (YES in S2), ultrasonic detection processing is performed to acquire the amplitude of the reflected waveform in the non-gripping state (S3). In addition, since the ultrasonic detection process in S3 is performed by placing the smartphone 101 on a desk, curves are provided on both sides (portions gripped by the user) of the housing 1 of the smartphone 101, and the both sides are on the desk. It is preferable to avoid direct contact. Thereby, it is possible to solve the problem that the both sides of the casing 1 of the smartphone 101 are in contact with the desk, for example, the problem that the attenuation rate of the reflected wave when not grasping cannot be obtained accurately.

  Subsequently, the average value of the amplitude (signal intensity) acquired in the ultrasonic detection process (S3) is recorded in the storage unit 25 as a reference value at the time of non-gripping (S4). Thereafter, a confirmation message for acquiring a reference value at the time of gripping is displayed on a display unit (not shown) (S5), and reception of a reference value acquisition start operation at the time of gripping is awaited (S6). For example, when the message “Please touch the screen after gripping the smartphone” is displayed as the confirmation message, the screen is touched by the user while the smartphone is gripped. Will be.

  Then, when a reference value acquisition start operation at the time of gripping is received (YES in S6), the ultrasonic detection process (S3) is performed while the smartphone 101 is gripped, and the average value of the acquired amplitude is referred to at the time of gripping. The value is recorded in the storage unit 25 (S7). The amplitude (reference value) of the reflected waveform obtained when the smartphone 101 is gripped and not gripped by the above processing is used in the gripping state detection process shown in FIG. 4 described later.

  In this way, by performing the calibration process, it is possible to appropriately detect the gripping state of the user without being influenced by the detection accuracy due to the individual difference of the smartphone 101.

(2) Ultrasonic Detection Processing Details of the ultrasonic detection processing will be described with reference to the flowchart shown in FIG. First, a plurality of ultrasonic waves are transmitted from the piezoelectric element 10 (S11). In addition, the ultrasonic wave transmitted at this time is a single pulse wave transmitted at a predetermined interval, such as the drive waveform generated by the drive waveform generator 21 (the drive waveform shown in FIG. 2B). It is a pair. A plurality of transmitted ultrasonic waves are reflected on the surface of the housing 1, and the reflected waves are received by the piezoelectric element 10 (S12). After the reflected wave is received by the piezoelectric element 10, the received ultrasonic wave is amplified by the amplifier 22 (S13), and the average value of the amplitude of the amplified ultrasonic wave is acquired (S14). The received ultrasonic wave is the shortest distance (cavity thickness d1) from the boundary surface with the outside of the housing 1 (hereinafter referred to as “cavity surface”), that is, a straight line extending horizontally from the surface of the piezoelectric element 10. What reciprocates between the straight lines connecting the cavity surface reaches the piezoelectric element 10 in the shortest time. Therefore, in order to selectively acquire this ultrasonic wave, the amplifier input unit 23 switches on / off the amplifier 22 at a timing before and after the reflected wave reaches the piezoelectric element 10.

(3) Holding state detection process Details of the holding state detection process of the smartphone 101 will be described with reference to the flowchart shown in FIG. First, the ultrasonic detection process shown in FIG. 3B is performed (S21), and the amplitude of the ultrasonic wave received by the piezoelectric element 10 in the current smartphone 101 is acquired. Next, the reflected pulse amplitude comparison unit 24 determines whether or not the amplitude of the acquired reflected wave is equal to or less than a predetermined value (S22). Here, as the predetermined value, the reference value of the gripping state and the non-griping state acquired by the calibration process is acquired from the storage unit 25, and the value obtained from this reference value and the amplitude of the reflected wave acquired in S21 Compare. As a specific example, when the amplitude of the reflected wave acquired in the ultrasonic detection process (S21) is A4, the amplitude A2 (reference value of the non-gripping state) and A3 (the gripping state) in the waveform diagram of FIG. It is determined whether a relationship such as A4 <A3 + (A2−A3) / 2 is satisfied with respect to the reference value. That is, the predetermined value in S22 is A3 + (A2-A3) / 2. The above-described relational expression used for determination of the gripping state is an example, and any relational expression can be used as long as the gripping state and the non-grip state can be clearly distinguished. Then, when the average value of the amplitude of the reflected wave is equal to or smaller than the predetermined value (YES in S22), the reflected pulse amplitude comparing unit 24 detects that the smartphone 101 is held (S23), and from the predetermined value If it is larger (NO in S22), it is detected that the smartphone 101 is not gripped (S24).

  Note that when it is detected that the smartphone 101 is gripped, a signal indicating that is sent to a control unit (not shown) of the smartphone 101, and for example, the screen is unlocked and the screen is lit while the user grips the smartphone 101. To be able to perform operations such as incoming calls.

[Embodiment 2]
Embodiment 1 of the present invention will be described in detail with reference to FIG. For convenience of explanation, members having the same functions as those described in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. The same applies to the following embodiments.

(Smartphone overview)
Based on (a) of FIG. 5, the outline | summary of the smart phone 102 which concerns on this Embodiment 2 is demonstrated. The smartphone 102 is structurally different from the smartphone 101 shown in FIG. A part of the housing 1 includes a protruding portion 1 b that protrudes inside the smartphone 102 so that the piezoelectric element 10 is located near the center of the smartphone 102 and maintains contact with the piezoelectric element 10. As a result, the cabinet thickness d2 is longer than the cabinet thickness d1 through which ultrasonic waves propagate in the smartphone 101 shown in FIG. That is, the cavity thickness d2 is a horizontal distance from the surface of the piezoelectric element 10 to the surface of the housing 1 and passing through the protruding portion 1b. Therefore, in the smartphone 102 according to the present embodiment, the detection device 2 determines whether or not the user has gripped from ultrasonic waves that reciprocate through the cavity thickness d2.

  Note that in the smartphone 102 shown in FIG. 5A, the piezoelectric element 10 moves away from the surface of the housing 1 by the amount of the protruding portion 1b, so that a plurality of reflected waves may overlap and the waveform amplitude may fluctuate. Therefore, as shown in FIG. 5B, a set of a plurality of pulses is used as the drive waveform.

  The reflected wave in this case will be described using a specific example as in the first embodiment. If the material of the housing 1 and the frequency of the ultrasonic waves and the sound velocity of the ultrasonic waves propagating inside the housing 1 are the same as in the first embodiment, if the cavity thickness d2 is 20 mm, the ultrasound reciprocates the cavity thickness d2. The time to perform is 14.9 μs. When a set of five pulse waves is used as the drive wave, it takes 0.1 μs from the start time of the first pulse to the end time of the fifth pulse. Therefore, the ultrasonic wave received on the surface of the piezoelectric element 10 within 1 μs after 14.9 μs after the generation of the driving wave can be used as a reflected wave for detecting the gripping state.

  In the case of this embodiment, since a set of a plurality of pulses is used as the drive waveform, the reflected wave also becomes a set of a plurality of pulses. Therefore, in the grip detection unit 20, when the average value of the amplitudes of a set of pulse waves that are reflected waves falls below a preset amplitude (a value obtained from the reference value recorded in the storage unit 25), the user It is detected that the casing 1 is gripped.

[Embodiment 3]
Embodiment 3 of the present invention will be described in detail with reference to FIG.

(Outline of smartphone 103)
Based on (a) of FIG. 6, the outline | summary of the smart phone 103 is demonstrated. The smartphone 103 is structurally different from the smartphone 101 shown in FIG. 2A in the following points. First, there is one piezoelectric element 10, and the piezoelectric element 10 is provided in the upper part of the inside 1 a of the housing 1. That is, the smartphone 103 directly provides the single piezoelectric element 10 at a position other than the position of the interior 1 a corresponding to the portion of the housing 1 that is held by the user.

  Since the smartphone 103 shown in FIG. 6A has a configuration including only one piezoelectric element 10, the cost can be reduced compared to the smartphones 101 and 102 of the first and second embodiments. However, in order to propagate through the housing 1 from the position held by the user's hand 3 and reach the piezoelectric element 10, it is necessary to go around the housing 1, so that a plurality of reflected waves overlap and the amplitude of the waveform varies. There is a fear. For this reason, it is necessary to adjust the input timing, the input period, and the like by the amplifier input unit 23 so that the reflected wave with respect to the portion of the housing 1 held by the user's hand 3 can be selectively acquired.

  Further, as an example in which the piezoelectric element 10 is integrated, there is a smartphone 104 shown in FIG. In the smartphone 104, as shown in FIG. 6B, an angle extending from the upper side of the interior 1 a of the housing 1 in a bowl shape is not directly provided in the interior 1 a of the housing 1. 4 is provided.

  Since the smartphone 104 shown in FIG. 6B has a configuration including one piezoelectric element 10 as in the smartphone 103 shown in FIG. 6A, cost reduction can be realized. Further, in the smartphone 104, the piezoelectric element 10 is connected to an angle 4 extending in a bowl shape from the upper side of the inside 1 a of the housing 1. In this case, since the resonance frequency of the angle 4 can be changed depending on the shape of the angle 4, a drive wave and a reflected wave having a specific frequency can be selectively propagated efficiently. Specifically, with respect to the angle 4, as shown in FIG. 6B, if the width of the portion protruding from the housing 1 is A and the width of the portion after bending the protruding portion in the horizontal direction is B, When A is increased (decreased), the resonance frequency can be increased (lowered), and when B is increased (decreased), the resonance frequency can be decreased (increased).

  In this embodiment, the smartphone 103 shown in FIG. 6A and the smartphone 104 shown in FIG. 6B both have a possibility that a plurality of reflected waves overlap and the waveform amplitude may fluctuate. Although the reflected wave can be selectively acquired using the input unit 23, if there are a plurality of acquired reflected waves, the average value of the amplitudes of the reflected waves is obtained in the gripping state as in the second embodiment. Whether or not there is will be detected.

[Modification]
Hereinafter, modifications of the first to third embodiments will be described with reference to FIG.

  In each of Embodiments 1 to 3, the piezoelectric element 10 has been described using an element that doubles as a transmitting unit that transmits ultrasonic waves and a receiving unit that receives ultrasonic waves. However, the piezoelectric element 10 is illustrated in FIG. As described above, the piezoelectric element 10a for transmission and the piezoelectric element 10b for reception may be used.

  7B to 7E are obtained by replacing the piezoelectric elements 10 of the smartphones 101 to 104 described in the first to third embodiments with a combination of a piezoelectric element 10a for transmission and a piezoelectric element 10b for reception. It is. As for the positional relationship between the transmitting piezoelectric element 10a and the receiving piezoelectric element 10b, if the positional relationship with the portion held by the user's hand 3 is taken into account, the upper, lower, left, and right may be interchanged. Good.

[Example of software implementation]
The control block (particularly the grip detection unit 20) of the detection device 2 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or software using a CPU (Central Processing Unit). It may be realized by.

  In the latter case, the detection device 2 includes a CPU that executes instructions of a detection program, which is software that implements each function, and a ROM (Read Only Memory) in which the detection program and various data are recorded so as to be readable by a computer (or CPU). ) Or a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) that expands the detection program, and the like. Then, the computer (or CPU) reads the detection program from the recording medium and executes it, thereby achieving the object of the present invention. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
The detection apparatus according to aspect 1 of the present invention is provided in a housing (1) that can be gripped by a user, and an ultrasonic wave generation unit (piezoelectric element 10) that generates ultrasonic waves that propagate through the housing (1). Whether or not the user is holding the casing (1) is detected from the attenuation rate of the reflected wave with respect to the incident wave generated from the ultrasonic wave generation unit (piezoelectric element 10) and incident on the casing (1). A grip detection unit (20).

  According to said structure, it is detected whether the user is holding the said housing | casing from the attenuation factor of the reflected wave with respect to the incident wave which generate | occur | produces from an ultrasonic wave generation part and injects into a housing | casing. In other words, since the grasping state is detected using ultrasonic waves of a frequency that cannot be heard by humans, as in the case of using the vibration function, vibration sounds reverberate around the user. No pleasure is given. Therefore, there is an effect that the detection of the gripping state can be realized without the surroundings including the user being conscious.

  In the detection device according to aspect 2 of the present invention, in the aspect 1, the grip detection unit (20) sets in advance the signal intensity of the reflected wave obtained by multiplying the signal intensity of the incident wave by the attenuation factor. It is good also as a structure which detects that the user is holding the said housing | casing, when it falls below signal strength.

  According to the above configuration, since it is possible to detect whether or not the user is holding the casing based on a preset signal strength, it is possible to change the signal strength that is a threshold used for the determination. It is possible to cope with various users having different housing materials and different gripping strengths of the housing.

  In the detection device according to aspect 3 of the present invention, in the aspect 2, the ultrasonic wave generation unit (piezoelectric element 10) generates incident wave ultrasonic waves as pulse waves, and the grip detection unit (20) The signal intensity may be the amplitude of the pulse wave, and when the amplitude of the pulse wave that is the reflected wave falls below a preset amplitude, it may be configured to detect that the user is holding the casing (1).

  According to said structure, since a reflected wave is a pulse wave, even if it is a case where multiple types of reflected waves exist, it becomes possible to selectively acquire a required reflected wave. Therefore, it is possible to accurately detect whether or not the user is holding the casing.

  In the detection device according to aspect 4 of the present invention, in the aspect 2, the ultrasonic wave generation unit generates ultrasonic waves of incident waves as a set of a plurality of pulse waves, and the grip detection unit pulses the signal intensity. It is good also as a structure which detects that the user is holding the said housing | casing, when it is set as the amplitude of a wave and the average value of the amplitude of a set of pulse waves which are reflected waves falls below the preset amplitude.

  According to the above configuration, the average value of the amplitude of a set of pulse waves that are reflected waves is obtained, and it is detected that the user is holding the casing, so that a plurality of reflected waves overlap each other. Even if it is detected by (1), it is possible to accurately detect whether or not the user is holding the casing.

  The detection apparatus according to each aspect of the present invention may be realized by a computer. In this case, the detection apparatus is realized by a computer by operating the computer as each unit (software element) included in the detection apparatus. A detection program of the detection device and a computer-readable recording medium on which the detection program is recorded also fall within the scope of the present invention.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

DESCRIPTION OF SYMBOLS 1 Case, 1a inside, 1b Protrusion part, 2 detection apparatus, 3 hand, 4 angle, 10 Piezoelectric element (ultrasonic wave generation part), 10a Transmission piezoelectric element, 10b Reception piezoelectric element, 20 Grasp detection part, 21 Drive Waveform Generator, 22 Amplifier, 23 Amplifier Input Unit, 24 Reflected Pulse Amplitude Comparison Unit, 25 Storage Unit, 101-104 Smartphone

Claims (5)

An ultrasonic wave generation unit that is provided in a case that can be gripped by a user and generates ultrasonic waves that propagate through the case;
A grip detection unit that detects whether or not the user is gripping the housing from an attenuation rate of a reflected wave with respect to an incident wave that is generated from the ultrasonic wave generation unit and is incident on the housing. A detection device characterized by.   The detection according to claim 1, wherein the grip detection unit detects that the user is gripping the casing when the signal strength of the reflected wave is lower than a preset signal strength. apparatus. The ultrasonic wave generator generates the ultrasonic wave of the incident wave as a pulse wave,
The grip detection unit uses the amplitude of the pulse wave of the reflected wave as the signal intensity of the reflected wave, and when the amplitude of the pulse wave that is the reflected wave falls below a preset amplitude, the user The detection device according to claim 2, wherein the detection device detects that the housing is gripped. The ultrasonic generator generates the ultrasonic wave of the incident wave as a set of a plurality of pulse waves,
The grip detection unit uses the average value of the amplitude of each pulse wave in a set of a plurality of pulse waves of the ultrasonic wave of the reflected wave as the signal intensity of the reflected wave, and the amplitude of the pulse wave set of the reflected wave The detection device according to claim 2, wherein when the average value falls below a preset amplitude, it is detected that the user is holding the casing. A detection program for causing a computer to function as the detection device according to claim 1, wherein the detection program causes the computer to function as the grip detection unit.

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