Electronic device

Abstract

An electronic device according to the present invention is provided with: a secondary battery having a first main surface and a second main surface arranged in a Z-axis direction; a rigid body facing the first principal surface; and a sensor that is attached to the rigid body and that detects elastic deformation of the rigid body caused by application of a force to the rigid body, the sensor not overlapping the secondary battery when viewed in the Z-axis direction, and the sensor being attached to the rigid body when viewed in the Z-axis direction. A first waveform of a signal output by the sensor when a force of the first mode is applied to the rigid body in a state in which the first principal surface is in contact with the rigid body is different from a second waveform of a signal output by the sensor when the force of the first mode is applied to the rigid body in a state in which the first principal surface is not in contact with the rigid body.

Description

Technical Field

[0001] The present invention relates to an electronic device including a secondary battery. Background Art

[0002] As a conventional invention related to electronic devices, for example, there is known a method for measuring battery expansion described in Patent Document 1. In this method, a sensor for detecting battery expansion is attached to a battery.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2021 / 0075068 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In addition, there is a demand for the electronic device capable of detecting battery expansion described in Patent Document 1 to be thinner.

[0008] Therefore, an object of the present invention is to achieve a reduction in the thickness of an electronic device capable of detecting the expansion of a secondary battery.

[0009] Solutions for solving problems

[0010] An electronic device according to one embodiment of the present invention includes:

[0011] A secondary battery having a first main surface and a second main surface arranged in a Z-axis direction;

[0012] a rigid body, which faces the first main surface; and

[0013] a sensor mounted on the rigid body and detecting elastic deformation of the rigid body caused by a force being applied to the rigid body,

[0014] Wherein, when viewed along the Z-axis direction, the sensor does not overlap with the secondary battery,

[0015] A first waveform of a signal output by the sensor when the first principal surface is in contact with the rigid body and the rigid body is imparted with a first mode of force is different from a second waveform of a signal output by the sensor when the first principal surface is not in contact with the rigid body and the rigid body is imparted with the first mode of force.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to achieve a reduction in the thickness of an electronic device capable of detecting the expansion of a secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a top view of the electronic device 1 .

[0019] Figure 2 It is a cross-sectional view of the electronic device 1 taken along the line AA.

[0020] Figure 3 1 is a top view of the sensor 6 and a cross-sectional view at BB.

[0021] Figure 4 It is a waveform diagram of the signal output by the sensor 6.

[0022] Figure 5 It is a cross-sectional view of the electronic device 1 taken along the line AA.

[0023] Figure 6 It is a waveform diagram of the signal output by the sensor 6.

[0024] Figure 7 4 is a front view of the display panel 4 and the sensor 6.

[0025] Figure 8 4 is a front view of the display panel 4 and the sensor 6.

[0026] Fig. 9 4 is a front view of the display panel 4 and the sensor 6.

[0027] Fig.10 4 is a front view of the display panel 4 and the sensor 6.

[0028] Fig.11 is a block diagram of the electronic device 1.

[0029] Fig.12 This is a flowchart executed by the control device 20 of the electronic device 1 .

[0030] Fig.13 is a cross-sectional view of the electronic device 1a.

[0031] Fig.14 is a cross-sectional view of the electronic device 1b. DETAILED DESCRIPTION

[0032] (Implementation Method)

[0033] Hereinafter, an electronic device 1 according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a top view of the electronic device 1 . Figure 2 and Figure 5 It is a cross-sectional view of the electronic device 1 taken along the line AA. Figure 3 1 is a top view of the sensor 6 and a cross-sectional view at BB. Figure 4 and Figure 6It is a waveform diagram of the signal output by the sensor 6. Figure 4 and Figure 6 The vertical axis is voltage. Figure 4 and Figure 6 The horizontal axis is time.

[0034] The electronic device 1 is, for example, a portable communication terminal such as a smart phone. In this specification, the direction in which the main surface of the electronic device 1 is arranged is defined as the up-down direction. The main surface of the electronic device 1 has a rectangular shape. The direction in which the long side of the main surface of the electronic device 1 extends is defined as the front-back direction. The direction in which the short side of the main surface of the electronic device 1 extends is defined as the left-right direction. The up-down direction, the left-right direction, and the front-back direction are orthogonal to each other. Figure 1 and Figure 2 As shown, the electronic device 1 includes a secondary battery 2 , a housing 3 , a display panel 4 , and a sensor 6 .

[0035] The housing 3 has a rectangular parallelepiped shape. Figure 2 As shown, the upper surface of the housing 3 does not exist. Therefore, the housing 3 is open upward.

[0036] like Figure 1 As shown in FIG. 1 , when viewed in the up-down direction, the display panel 4 has a rectangular shape. Figure 2 As shown, the display panel 4 covers the opening of the housing 3. Thus, the housing 3 and the display panel 4 have a box shape. The display panel 4 is a rigid body. The display panel 4 is a liquid crystal display panel or an organic EL panel. In addition, the display panel 4 has a built-in touch panel.

[0037] The secondary battery 2 is, for example, a lithium-ion battery. The secondary battery 2 has a first main surface S1 and a second main surface S2 arranged in the up-down direction (Z-axis direction). The first main surface S1 is located above the second main surface S2. The secondary battery 2 is arranged in a space surrounded by the housing 3 and the display panel 4. The secondary battery 2 is located below the display panel 4. Thus, the display panel 4 (rigid body) faces the first main surface S1. When the secondary battery 2 is not expanded, the distance between the first main surface S1 and the display panel 4 (rigid body) is smaller than the thickness of the sensor 6 in the up-down direction. For example, when the secondary battery 2 is not expanded, the distance between the first main surface S1 and the display panel 4 (rigid body) is greater than 0.3 mm and less than 1.5 mm.

[0038] The sensor 6 is mounted on the display panel 4 (rigid body). In the present embodiment, the sensor 6 is mounted on the lower main surface of the display panel 4. Moreover, when viewed in the up-down direction (Z-axis direction), the sensor 6 does not overlap with the secondary battery 2. The sensor 6 detects elastic deformation of the display panel 4 (rigid body) caused by the force applied to the display panel 4 (rigid body). The sensor 6 is described in detail below.

[0039] When viewed in the up-down direction, the sensor 6 has a rectangular shape. The sensor 6 has a long side extending in the left-right direction. Figure 3 As shown, the sensor 6 includes a piezoelectric film 14, an upper electrode 15a and a lower electrode 15b. The piezoelectric film 14 has a thin sheet shape. Therefore, the piezoelectric film 14 has an upper main surface and a lower main surface. The length of the piezoelectric film 14 in the left-right direction is longer than the length of the piezoelectric film 14 in the front-back direction. In the present embodiment, when viewed in the up-down direction, the piezoelectric film 14 has a rectangular shape having a long side extending in the left-right direction. The piezoelectric film 14 generates an electric charge corresponding to the deformation amount of the piezoelectric film 14. In the present embodiment, the piezoelectric film 14 is a PLA film. Below, the piezoelectric film 14 is described in more detail.

[0040] The piezoelectric film 14 has the following characteristics: the polarity of the charge generated when the piezoelectric film 14 is stretched in the left-right direction is opposite to the polarity of the charge generated when the piezoelectric film 14 is stretched in the front-back direction. Specifically, the piezoelectric film 14 is a film formed of a chiral polymer. The chiral polymer refers to polylactic acid (PLA), especially L-type polylactic acid (PLLA). The main chain of PLLA composed of chiral polymers has a helical structure. PLLA has piezoelectricity in which the molecules are oriented after being uniaxially stretched. The piezoelectric film 14 has a piezoelectric constant of d14. The uniaxial stretching direction (orientation direction) of the piezoelectric film 14 forms an angle of 45 degrees with the front-back direction and the left-right direction, respectively. The 45 degrees, for example, includes an angle of about 45 degrees ± 10 degrees. Thus, the piezoelectric film 14 generates an electric charge by stretching the piezoelectric film 14 in the left-right direction or compressing it in the left-right direction. For example, the piezoelectric film 14 generates a negative charge when it is stretched in the left-right direction. For example, the piezoelectric film 14 generates a positive charge when it is compressed in the left-right direction. The magnitude of the charge depends on the amount of deformation of the piezoelectric film 14 due to tension or compression. More precisely, the magnitude of the charge is proportional to the differential value of the deformation of the piezoelectric film 14 due to tension or compression.

[0041] The upper electrode 15 a is a signal electrode. A detection signal is output from the upper electrode 15 a. The upper electrode 15 a is provided on the upper main surface of the piezoelectric film 14. The lower electrode 15 b is a ground electrode. The lower electrode 15 b is connected to the ground. The lower electrode 15 b is provided on the lower main surface of the piezoelectric film 14.

[0042] The electronic device 1 also includes a current / voltage conversion circuit and an amplifier circuit. However, the current / voltage conversion circuit and the amplifier circuit are common circuits, and thus their description is omitted.

[0043] The upper electrode 15a of the sensor 6 as described above is fixed to the lower main surface of the display panel 4 by double-sided tape or the like. Therefore, when the display panel 4 is pressed downward by the user, the sensor 6 extends in the front-to-back direction. Figure 4 As shown, the sensor 6 outputs a signal having a positive voltage with respect to the reference potential V0.

[0044] In addition, when the secondary battery 2 is repeatedly charged and discharged, Figure 5 As a result, the first main surface S1 of the secondary battery 2 contacts the display panel 4. In this case, Figure 6 As shown, the sensor 6 outputs a signal having a negative voltage relative to the reference potential V0. Thus, when the first main surface S1 is in contact with the display panel 4 (rigid body) and the display panel 4 (rigid body) is given a force of the first pattern, the first waveform P1 (refer to Figure 4 ) is different from the second waveform P2 (refer to FIG. 1 ) of the signal output by the sensor 6 when the display panel 4 (rigid body) is given the first pattern of force in a state where the first main surface S1 is not in contact with the display panel 4 (rigid body). Figure 6 ). In the present embodiment, the polarity of the first waveform P1 with respect to the reference potential V0 is different from the polarity of the second waveform P2 with respect to the reference potential V0.

[0045] Here, the reason why the polarity of the first waveform P1 with respect to the reference potential V0 is different from the polarity of the second waveform P2 with respect to the reference potential V0 will be described with reference to the drawings. Figures 7 to 10 is a front view of the display panel 4 and the sensor 6. Figure 7 and Figure 8 In the embodiment, the first main surface S1 is not in contact with the display panel 4. Fig. 9 and Fig.10 In the embodiment, the first main surface S1 is in contact with the display panel 4 .

[0046] like Figure 7 As shown in FIG. 1 , when the first main surface S1 is not in contact with the display panel 4 and no force is applied to the display panel 4, the display panel 4 has a flat plate shape. Then, when the user presses the display panel 4 downward, as shown in FIG. Figure 8 As shown in FIG. 1 , the display panel 4 is bent in a manner protruding downward. At this time, the sensor 6 is also bent together with the display panel 4. Moreover, the sensor 6 is stretched in the front-back direction. Figure 4 As shown, a signal having a positive voltage with respect to the reference potential V0 is output.

[0047] On the other hand, Fig. 9 As shown, when the first main surface S1 is in contact with the display panel 4, the display panel 4 is bent in a manner of protruding upward. When the user presses the display panel 4 downward in this state, as shown in FIG. Fig.10As shown in FIG. 1 , the display panel 4 is deformed in such a way that the portion pressed by the user protrudes downward and the portion provided with the sensor 6 protrudes upward. At this time, the sensor 6 is also bent together with the display panel 4. Moreover, the sensor 6 is compressed in the front-to-back direction. As a result, as shown in FIG. Figure 6 As shown, a signal having a negative voltage with respect to the reference potential V0 is output.

[0048] As described above, in the electronic device 1, when the first main surface S1 is in contact with the display panel 4 and the display panel 4 is given a first pattern of force, the first waveform P1 of the signal output by the sensor 6 is different from the second waveform P2 of the signal output by the sensor 6 when the display panel 4 is given a first pattern of force when the first main surface S1 is not in contact with the display panel 4. Therefore, the electronic device 1 can determine whether an abnormality has occurred in the secondary battery 2 based on the signal output by the sensor 6. Next, the operation performed by the electronic device 1 is described with reference to the accompanying drawings. Fig.11 is a block diagram of the electronic device 1. Fig.12 This is a flowchart executed by the control device 20 of the electronic device 1 .

[0049] like Fig.11 As shown, the electronic device 1 further includes a control device 20. The control device 20 is, for example, a CPU (Central Processing Unit). The control device 20 executes a program stored in a storage device (not shown). Fig.12 Flowchart shown.

[0050] The control device 20 acquires a signal from the sensor 6 (step S1). Next, the control device 20 determines whether the polarity of the signal acquired in step S1 is negative (step S2). If the polarity of the signal is negative, the process proceeds to step S3. If the polarity of the signal is not negative, the process returns to step S1.

[0051] When the polarity of the signal is negative, it is because the secondary battery 2 has expanded and the first main surface S1 is in contact with the display panel 4. Therefore, the control device 20 determines that an abnormality has occurred in the secondary battery 2 (step S3). The control device 20 stops charging the secondary battery 2 (step S4). Then, the control device 20 causes the display panel 4 to display that an abnormality has occurred (step S5). Thus, this process ends.

[0052] [Effect]

[0053] According to the electronic device 1, it is possible to achieve a thinner electronic device 1 capable of detecting the expansion of the secondary battery 2. More specifically, in the method for measuring the expansion of a battery described in Patent Document 1, a sensor for detecting the expansion of the battery is attached to the battery. In this case, a space having a total thickness of the thickness of the sensor and the thickness of the battery must be present in the housing.

[0054] On the other hand, the electronic device 1 includes a sensor 6 that detects elastic deformation of the display panel 4 caused by the force applied to the display panel 4. Moreover, the first waveform P1 of the signal output by the sensor 6 when the first pattern of force is applied to the display panel 4 in a state where the first main surface S1 is in contact with the display panel 4 is different from the second waveform P2 of the signal output by the sensor 6 when the first pattern of force is applied to the display panel 4 in a state where the first main surface S1 is not in contact with the display panel 4. Thus, the control device 20 can determine whether the first main surface S1 is in contact with the display panel 4 based on the waveform of the signal. That is, the control device 20 can detect the expansion of the secondary battery 2. Moreover, when viewed in the up and down direction, such a sensor 6 does not overlap with the secondary battery 2. Therefore, it is sufficient as long as there is a space having the thickness of the secondary battery 2 in the housing 3. As described above, according to the electronic device 1, it is possible to achieve a thinner electronic device 1 capable of detecting the expansion of the secondary battery 2. That is, the sensor 6 can be provided while maintaining the capacity of the secondary battery 2 of the electronic device 1.

[0055] In addition, according to the electronic device 1, the electronic device 1 can be miniaturized. More specifically, the sensor 6 detects the elastic deformation of the display panel 4. Therefore, the control device 20 can use the signal of the sensor 6 to calculate the magnitude of the force with which the user presses the display panel 4. Therefore, the sensor 6 functions as a pressure sensor and an expansion sensor of the secondary battery 2. As a result, in the electronic device 1, two sensors are not required, so the electronic device 1 can be miniaturized.

[0056] (Variant 1)

[0057] Next, an electronic device 1 a according to a first modification example will be described with reference to the drawings. Fig.13 is a cross-sectional view of the electronic device 1a.

[0058] The electronic device 1a is different from the electronic device 1 in that it further includes a rigid body 5 and a deformation generating device 7. The rigid body 5 is, for example, a part of the housing of the electronic device 1a, a frame, a circuit board, or the like.

[0059] The deformation generating device 7 applies force to the rigid body 5 to elastically deform the rigid body 5. The deformation generating device 7 is a vibrator. Examples of the vibrator are LRA, voice coil motor, eccentric motor, etc. Therefore, the deformation generating device 7 vibrates. The rigid body 5 is elastically deformed by the vibration of the deformation generating device 7.

[0060] The sensor 6 is mounted on the rigid body 5. The distance between the sensor 6 and the secondary battery 2 is shorter than the distance between the sensor 6 and the deformation generating device 7. Moreover, the sensor 6 detects the elastic deformation of the rigid body 5 caused by the force applied to the rigid body 5 by the deformation generating device 7. The first waveform P1 of the signal output by the sensor 6 when the rigid body 5 is applied with the first mode of force in a state where the first main surface S1 is in contact with the rigid body 5 is different from the second waveform P2 of the signal output by the sensor 6 when the rigid body 5 is applied with the first mode of force in a state where the first main surface S1 is not in contact with the rigid body 5. The other structures of the electronic device 1a are the same as those of the electronic device 1, so the description is omitted.

[0061] The distance between the sensor 6 and the secondary battery 2 is shorter than the distance between the sensor 6 and the deformation generating device 7, so the rigid body 5 is Fig.10 Change like that.

[0062] (Variant 2)

[0063] Next, an electronic device 1 b according to a second modification example will be described with reference to the drawings. Fig.14 is a cross-sectional view of the electronic device 1b.

[0064] Electronic device 1b is a wireless headset. Electronic device 1b includes a secondary battery 2, a housing 3, a sensor 6, a deformation generating device 7, and a control device 20. The deformation generating device 7 is a speaker. The deformation generating device 7 causes the housing 3 to vibrate when generating sound. Thus, the deformation generating device 7 causes the housing 3 (rigid body) to generate elastic deformation by applying force to the housing 3 (rigid body). The sensor 6 is mounted on the housing 3 (rigid body) to detect the elastic deformation of the housing 3 (rigid body) caused by the force applied to the housing 3 (rigid body). The other structures of the electronic device 1b are the same as those of the electronic device 1a, so the description is omitted.

[0065] (Other Embodiments)

[0066] The electronic device according to the present invention is not limited to the electronic devices 1, 1a, and 1b, and can be modified within the scope of the gist thereof.

[0067] Furthermore, the structures of the electronic devices 1, 1a, and 1b may be combined arbitrarily.

[0068] In addition, the polarity of the first waveform P1 relative to the reference potential V0 may not be different from the polarity of the second waveform P2 relative to the reference potential V0. Therefore, it is sufficient that the first waveform P1 is different from the second waveform P2. In other words, the polarity of the second waveform P2 relative to the reference potential V0 may be the same as the polarity of the first waveform P1 relative to the reference potential V0.

[0069] Furthermore, when the polarity of the signal is negative, the control device 20 notifies the user of the abnormality of the secondary battery 2. That is, when the polarity of the first waveform P1 with respect to the reference potential V0 is different from the polarity of the second waveform P2 with respect to the reference potential V0, the control device 20 notifies the user of the abnormality of the secondary battery 2. However, when the first waveform P1 is different from the second waveform P2, the control device 20 may notify the user of the abnormality of the secondary battery 2 through the display panel 4 (notification device).

[0070] Furthermore, when the polarity of the signal is negative, the control device 20 stops charging the secondary battery 2. That is, when the polarity of the first waveform P1 with respect to the reference potential V0 is different from the polarity of the second waveform P2 with respect to the reference potential V0, the control device 20 stops charging the secondary battery 2. However, the control device 20 may stop charging the secondary battery 2 when the first waveform P1 is different from the second waveform P2.

[0071] Alternatively, a flexible printed circuit board including wiring of the sensor 6 may be integrated with the sensor 6 .

[0072] In addition, the control device 20 may also notify the user of the abnormality of the secondary battery 2 through the speaker. In addition, the sensor 6 may also be a sensor for detecting that the game controller is grasped by the user. In addition, when the electronic device 1, 1a is a smart watch, the sensor 6 may also be a sensor for detecting the user's pulse.

[0073] The material of the rigid body 5 is, for example, glass, metal, ceramic, or resin.

[0074] The present invention has the following structures. (1)

[0076] An electronic device comprising:

[0077] A secondary battery having a first main surface and a second main surface arranged in a Z-axis direction;

[0078] a rigid body, which faces the first main surface; and

[0079] a sensor mounted on the rigid body and detecting elastic deformation of the rigid body caused by a force being applied to the rigid body,

[0080] Wherein, when viewed along the Z-axis direction, the sensor does not overlap with the secondary battery,

[0081] A first waveform of a signal output by the sensor when the first principal surface is in contact with the rigid body and the rigid body is imparted with a first mode of force is different from a second waveform of a signal output by the sensor when the first principal surface is not in contact with the rigid body and the rigid body is imparted with the first mode of force. (2)

[0083] The electronic device according to (1), wherein:

[0084] The polarity of the first waveform with respect to a reference potential is different from the polarity of the second waveform with respect to the reference potential. (3)

[0086] The electronic device according to (1) or (2), wherein:

[0087] The electronic device further includes a deformation generating device configured to elastically deform the rigid body by applying a force to the rigid body. (4)

[0089] The electronic device according to any one of (1) to (3), wherein:

[0090] The electronic device comprises:

[0091] Control devices; and

[0092] Notification device,

[0093] In a case where the first waveform is different from the second waveform, the control device notifies a user of an abnormality of the secondary battery through the notification device. (5)

[0095] The electronic device according to any one of (1) to (4), wherein:

[0096] The electronic device comprises a control device,

[0097] The control device stops charging of the secondary battery when the first waveform is different from the second waveform. (6)

[0099] The electronic device according to any one of (1) to (5), wherein:

[0100] The distance between the first main surface and the rigid body is smaller than the thickness of the sensor in the Z-axis direction. (7)

[0102] The electronic device according to any one of (1) to (6), wherein:

[0103] The distance between the first main surface and the rigid body is less than 1.5 mm. (8)

[0105] The electronic device according to any one of (1) to (7), wherein:

[0106] The first main surface is in contact with the rigid body due to expansion of the secondary battery.

[0107] Description of Reference Numerals

[0108] 1, 1a, 1b: electronic device; 2: secondary battery; 3: housing; 4: display panel; 5: rigid body; 6: sensor; 7: deformation generating device; 20: control device; S1: first main surface; S2: second main surface.

Claims

1. An electronic device comprising: A secondary battery having a first main surface and a second main surface arranged in a Z-axis direction; a rigid body, which faces the first main surface; and a sensor mounted on the rigid body and detecting elastic deformation of the rigid body caused by a force being applied to the rigid body, in, When viewed along the Z-axis direction, the sensor does not overlap with the secondary battery. A first waveform of a signal output by the sensor when the first principal surface is in contact with the rigid body and the rigid body is imparted with a first mode of force is different from a second waveform of a signal output by the sensor when the first principal surface is not in contact with the rigid body and the rigid body is imparted with the first mode of force.

2. The electronic device according to claim 1, wherein: The polarity of the first waveform with respect to a reference potential is different from the polarity of the second waveform with respect to the reference potential.

3. The electronic device according to claim 1 or 2, wherein: The electronic device further includes a deformation generating device configured to elastically deform the rigid body by applying a force to the rigid body.

4. The electronic device according to any one of claims 1 to 3, wherein: The electronic device comprises: Control devices; as well as Notification device, In a case where the first waveform is different from the second waveform, the control device notifies a user of an abnormality of the secondary battery through the notification device.

5. The electronic device according to any one of claims 1 to 4, wherein: The electronic device comprises a control device, The control device stops charging of the secondary battery when the first waveform is different from the second waveform.

6. The electronic device according to any one of claims 1 to 5, wherein: The distance between the first main surface and the rigid body is smaller than the thickness of the sensor in the Z-axis direction.

7. The electronic device according to any one of claims 1 to 6, wherein: The distance between the first main surface and the rigid body is less than 1.5 mm.

8. The electronic device according to any one of claims 1 to 7, wherein: The first main surface is in contact with the rigid body due to expansion of the secondary battery.

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