Grip load detection device

Abstract

This grip load detection device comprises: a housing that has elasticity; a sensor that is attached to the housing and has an electrical characteristic that changes due to deformation; a notification unit that has a plurality of notification patterns corresponding to the size of a load applied to the housing; and a control circuit that switches the notification pattern on the basis of an output signal from the sensor. The plurality of notification patterns include a no load notification pattern corresponding to no load and a maximum load notification pattern corresponding to the maximum load. The control circuit switches the notification pattern in a stepwise manner from the no load notification pattern to the maximum load notification pattern in accordance with the value of the output signal, and stops the notification from the notification unit when the value of the output signal has continuously been greater than or equal to a threshold value for a prescribed period or longer.

Description

Gripping load detection device

[0001] The present invention relates to a grip load detection device.

[0002] A known example of a conventional grip load detection device is the grip load detection device described in Patent Document 1. The grip load detection device described in Patent Document 1 includes a cylindrical housing that is held by a user, a sensor attached to the housing that detects a load applied to the housing due to the user's grip, and a display unit that visually indicates the load applied to the housing. The display unit is disposed inside the housing.

[0003] Patent No. 6954483

[0004] In the grip load detection device described in Patent Document 1, if a user grips the housing and continues to twist the grip load detection device with a strong force, the housing may be damaged.

[0005] Therefore, an object of the present invention is to provide a grip load detection device that can prevent excessive load from being continuously applied to the grip load detection device.

[0006] A grip load detection device according to one embodiment of the present invention comprises: an elastic housing; a sensor attached to the housing and whose electrical characteristics change with deformation; a notification unit having a plurality of notification patterns according to the magnitude of the load on the housing; and a control circuit that switches the notification pattern based on an output signal of the sensor, wherein the plurality of notification patterns include a no-load notification pattern corresponding to no load and a maximum load notification pattern corresponding to a maximum load, and the control circuit switches the notification pattern in stages from the no-load notification pattern to the maximum load notification pattern according to the value of the output signal, and stops notification from the notification unit when the value of the output signal remains above a threshold for a predetermined period of time or more.

[0007] The control circuit switches the notification pattern of the notification unit in stages from a no-load notification pattern to a maximum-load notification pattern according to the value of the output signal of the sensor, and when the value of the output signal remains above a threshold for a predetermined period of time or more, the control circuit stops the notification from the notification unit, thereby making the user aware of an abnormality in the grip load detection device. This allows the user to reduce the load applied to the grip load detection device.

[0008] According to the present invention, it is possible to prevent an excessive load from being continuously applied to the grip load detection device.

[0009] FIG. 1 is a perspective view of the grip load detection device 1. FIG. 2 is a cross-sectional view showing a portion of the grip load detection device 1 in a first section S1. FIG. 3 is a cross-sectional view showing a portion of the grip load detection device 1 in a second section S2. FIG. 4 is an exploded perspective view of the sensor 5 before being attached to the outer surface OS2 of the housing 2. FIG. 5 is a block diagram of the grip load detection device 1. FIG. 6 is a diagram showing an example of a lighting pattern of the light-emitting body 6. FIG. 7 is a diagram showing an example of a change in the voltage signal SigV over time. FIG. 8 is a diagram showing an example of a change in the voltage signal SigV over time. FIG. 9 is a diagram showing an example of a thirteenth threshold TH13 having hysteresis. FIG. 10 is a diagram showing an example of a change in the voltage signal SigV over time. FIG. 11 is a diagram showing an example of a change in the voltage signal SigV over time.

[0010] [First Embodiment] A gripping load detection device 1 according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the gripping load detection device 1. FIG. 2 is a cross-sectional view showing a part of the gripping load detection device 1 in a first section S1. FIG. 3 is a cross-sectional view showing a part of the gripping load detection device 1 in a second section S2. FIG. 4 is an exploded perspective view of the sensor 5 before it is attached to the outer surface OS2 of the housing 2. FIG. 5 is a block diagram of the gripping load detection device 1. FIG. 6 shows an example of a lighting pattern of the light-emitting body 6.

[0011] In this specification, directions are defined as follows, for example. As shown in Fig. 1 , one of the directions in which the central axis CA of the housing 2 extends is defined as a first direction DIR1. One of the radial directions centered on the central axis CA of the housing 2 is defined as a second direction DIR2. The first direction DIR1 and the second direction DIR2 are perpendicular to each other.

[0012] As shown in FIG. 4 , before the sensor 5 is attached to the outer surface OS2 of the housing 2, the direction in which the long side of the upper main surface US51 of the piezoelectric film 51 extends is defined as the left-right direction. Before the sensor 5 is attached to the outer surface OS2 of the housing 2, the direction in which the short side of the upper main surface US51 of the piezoelectric film 51 extends is defined as the front-rear direction. Before the sensor 5 is attached to the outer surface OS2 of the housing 2, the direction in which the upper main surface US51 and the lower main surface DS51 of the piezoelectric film 51 are aligned is defined as the up-down direction. The left-right direction, front-rear direction, and up-down direction are perpendicular to each other. Viewing in the up or down direction corresponds to the planar view according to the present invention. However, the left-right direction, front-rear direction, and up-down direction in this specification are defined for convenience of explanation and may not coincide with the left-right direction, front-rear direction, and up-down direction in the state after the sensor 5 is attached to the outer surface OS2 of the housing 2. In addition, in FIG. 4, the left and right directions may be interchanged, the front and rear directions may be interchanged, and the up and down directions may be interchanged.

[0013] The grip load detection device 1 is used by a user as a fitness tool. As shown in Figures 1 to 3, the grip load detection device 1 includes a housing 2, a cover 3, a grip 4, a sensor 5, a light emitter 6, a circuit board 7, and an adhesive member 8. The user holds the grip 4 and applies a twisting motion to the grip load detection device 1. The light emitter 6 corresponds to a notification unit according to the present invention.

[0014] The housing 2 has elasticity. As shown in FIG. 1 , the housing 2 has a cylindrical shape extending along the first direction DIR1. In this embodiment, the housing 2 is a polygonal tube. That is, the housing 2 has an outer surface OS2 and an inner surface IS2. In this embodiment, the housing 2 has transparency. Note that the housing 2 does not have to be cylindrical. When the housing 2 is cylindrical, it may have a cylindrical shape or the like. Furthermore, the housing 2 does not have to be transparent.

[0015] A cover 3 covering the outer surface OS2 of the housing 2 is provided in the center of the housing 2 in the first direction DIR1. Here, the section where the housing 2 and the cover 3 overlap as viewed in the second direction DIR2 is defined as a first section S1. The cover 3 has a tubular shape extending along the first direction DIR1. In this embodiment, the cover 3 is a cylinder. The cover 3 is also transparent. Note that the cover 3 may be a cylindrical shape, such as a square tube, as long as it is cylindrical. The cover 3 does not have to be transparent.

[0016] Grips 4 are provided at both ends of the housing 2 in the first direction DIR1, covering the outer surface OS2 of the housing 2. Here, the section where the housing 2 and the grip 4 overlap when viewed in the second direction DIR2 is defined as a second section S2. The grip 4 has a tubular shape extending along the first direction DIR1. In this embodiment, the grip 4 is cylindrical. More specifically, the cross section of the outer surface of the grip 4 along the first direction DIR1 is circular. The cross section of the inner surface of the grip 4 along the first direction DIR1 is polygonal. The static friction coefficient of the outer surface of the grip 4 is greater than the static friction coefficient of the outer surface OS2 of the housing 2. In other words, the static friction coefficient of the surface of the grip 4 is greater than the static friction coefficient of the surface of the housing 2. In other words, the surface of the grip 4 is less slippery than the surface of the housing 2. The material of the grip 4 is, for example, silicone rubber. The grip 4 is not transparent. In this embodiment, the end of the grip 4 on the end side of the grip load detection device 1 in the first direction DIR1 is closed. The grip 4 may be any cylindrical shape, such as a rectangular tube. The material of the grip 4 is not limited to silicone rubber. The grip 4 may also be transparent. The end of the grip 4 on the end side of the grip load detection device 1 in the first direction DIR1 may also be open.

[0017] As shown in FIG. 2 , a transparent sensor 5 is attached to the outer surface OS2 of the housing 2 in the first section S1 using an adhesive (not shown). That is, the sensor 5 is attached to the housing 2. Furthermore, a light emitter 6 is provided on the inner surface IS2 of the housing 2 in the first section S1. In this embodiment, the light emitter 6 is a light-emitting diode (LED) and includes three three-color LEDs. Hereinafter, the three three-color LEDs are referred to as a first LED 61, a second LED 62, and a third LED 63. The first LED 61, the second LED 62, and the third LED 63 are aligned along the first direction DIR1. A user visually recognizes the light emitted by the light emitter 6 through the transparent housing 2, the sensor 5, and the cover 3. Note that the light emitter 6 does not necessarily have to include three three-color LEDs. Furthermore, the light emitter 6 is not limited to an LED.

[0018] 4, the sensor 5 includes a piezoelectric film 51, a first electrode 52, a first adhesive material 53, a second adhesive material 54, and a second electrode 55.

[0019] The piezoelectric film 51 is flat. When unfolded on a plane, the piezoelectric film 51 has an upper principal surface US51 and a lower principal surface DS51 that are aligned in the vertical direction. The piezoelectric film 51 in the unfolded state will be described below.

[0020] Each of the upper principal surface US51 and the lower principal surface DS51 has a rectangular shape with two long sides extending in the left-right direction and two short sides extending in the front-rear direction. The left-right direction corresponds to the longitudinal direction according to the present invention.

[0021] The piezoelectric film 51 has a piezoelectric body. The piezoelectric body is polarized by deformation, generating electric charges on the upper principal surface US51 and the lower principal surface DS51. That is, the electrical characteristics of the piezoelectric film 51 change as the piezoelectric film 51 is deformed.

[0022] The piezoelectric material is, for example, a chiral polymer. The chiral polymer is, for example, polylactic acid (PLA), such as poly-L-lactic acid (PLLA) and poly-D-lactic acid (PDLA). The main chain of PLA has a helical structure. PLA has a piezoelectric constant of d14. The piezoelectric material may also be polyvinylidene fluoride.

[0023] The PLA is stretched in at least one axial direction OD. In this embodiment, the axial direction OD forms an angle of 0 degrees with respect to the left-right direction when viewed from the top-bottom direction. This 0 degrees includes approximately 0 degrees ±10 degrees. When the piezoelectric film 51 is stretched or compressed in a direction at 45 degrees to the left-right direction, electric charges are generated on the upper principal surface US51 and the lower principal surface DS51. Similarly, when the piezoelectric film 51 is stretched or compressed in a direction at 135 degrees to the left-right direction, electric charges are generated on the upper principal surface US51 and the lower principal surface DS51. In other words, when the piezoelectric film 51 is twisted, electric charges are generated. The electric charges generated on the upper principal surface US51 and the lower principal surface DS51 depend on the amount of twist of the piezoelectric film 51. Note that the polarity of the electric charges generated when the piezoelectric film 51 is stretched in a direction at 45 degrees to the left-right direction is opposite to the polarity of the electric charges generated when the piezoelectric film 51 is stretched in a direction at 135 degrees to the left-right direction. In this embodiment, the magnitude of the amount of charge generated on the upper principal surface US51 and the lower principal surface DS51 is proportional to the amount of twist of the piezoelectric film 51. Furthermore, the uniaxial direction OD may form an angle of 90 degrees with respect to the left-right direction when viewed in the up-down direction. This 90 degrees includes approximately 90 degrees ±10 degrees.

[0024] The first electrode 52 is a ground electrode. The first electrode 52 is provided on the upper main surface US51 of the piezoelectric film 51 with a first adhesive 53. The first electrode 52 is electrically connected to the ground potential, thereby functioning as a reference electrode and a shield conductor. More specifically, the first electrode 52 has a first substrate 521 and a first conductive film 522. The first conductive film 522 covers the lower main surface of the first substrate 521. The first conductive film 522 is electrically connected to the ground potential. The first conductive film 522 covers the upper main surface US51 of the piezoelectric film 51 with the first adhesive 53 interposed therebetween.

[0025] The second electrode 55 is a signal electrode. The second electrode 55 is provided on the lower main surface DS51 of the piezoelectric film 51 by the second adhesive 54. The second electrode 55 outputs a signal SigO corresponding to the charge generated by the piezoelectric film 51. More specifically, the second electrode 55 has a second base material 551 and a second conductive film 552. The second conductive film 552 covers the upper main surface of the second base material 551. The second conductive film 552 covers the lower main surface DS51 of the piezoelectric film 51 via the second adhesive 54.

[0026] In this embodiment, the sensor 5 is attached to the outer surface OS2 of the housing 2 so that the long sides of the upper principal surface US51 and the lower principal surface DS51 of the piezoelectric film 51 extend along the first direction DIR1. Note that the sensor 5 may also be attached to the outer surface OS2 of the housing 2 so that the short sides of the upper principal surface US51 and the lower principal surface DS51 of the piezoelectric film 51 extend along the first direction DIR1.

[0027] As shown in Fig. 3, the grip 4 is attached to the outer surface OS2 of the housing 2 in the second section S2 with an adhesive member 8. In addition, a circuit board 7 is provided on the inner surface IS2 of the housing 2 in the second section S2. As shown in Fig. 5, the circuit board 7 has a detection circuit 71 and an MPU 72.

[0028] The detection circuit 71 is electrically connected to the first electrode 52 and the second electrode 55 of the sensor 5. The detection circuit 71 converts the signal SigO output by the second electrode 55 into a voltage signal and amplifies the voltage signal. The detection circuit 71 outputs the amplified voltage signal SigV. That is, the voltage signal SigV is based on the signal SigO. The signal SigO corresponds to the output signal of the sensor 5 according to the present invention.

[0029] The MPU 72 is electrically connected to the detection circuit 71. The MPU 72 is, for example, a Micro Processing Unit (MPU). More specifically, the MPU 72 has a control circuit 721 and a memory 722. The voltage signal SigV output by the detection circuit 71 is input to the control circuit 721. The control circuit 721 outputs control signals SigC1 to SigC3 based on the voltage signal SigV, and reads out a program for processing to control the turning on and off of the light emitter 6 from the memory 722. The memory 722 has, for example, a read-only memory (ROM) and a random access memory (RAM). The control circuit 721 reads out the program stored in the ROM into the RAM. As a result, the control circuit 721 outputs control signals SigC1 to SigC3 based on the voltage signal SigV and performs processing to control the turning on and off of the light-emitting body 6. That is, the control circuit 721 switches the lighting pattern of the light-emitting body 6 based on the output signal of the sensor 5. The lighting pattern of the light-emitting body 6 corresponds to the notification pattern according to the present invention.

[0030] As shown in FIG. 6 , the light emitter 6 has multiple lighting patterns corresponding to the magnitude of the load on the housing 2. In this embodiment, the multiple lighting patterns include a no-load lighting pattern corresponding to no load, 12 intermediate load lighting patterns corresponding to intermediate loads, and a maximum load lighting pattern corresponding to maximum load. An intermediate load is greater than no load and less than maximum load. The number of intermediate load lighting patterns does not have to be 12. The multiple lighting patterns do not have to include the intermediate load lighting pattern. The no-load lighting pattern corresponds to the no-load notification pattern of the present invention. The intermediate load lighting pattern corresponds to the intermediate load notification pattern of the present invention. The maximum load lighting pattern corresponds to the maximum load notification pattern of the present invention. Note that "no load" does not only refer to a case where the load is completely zero, but may also be set to include a value equal to or less than the load magnitude corresponding to a value set as a threshold value (corresponding to the first threshold value described below) corresponding to the first intermediate load notification pattern.

[0031] When the user is not twisting the grip load detection device 1 and there is no load, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63. That is, in this embodiment, the no-load lighting pattern is one in which the first LED 61, the second LED 62, and the third LED 63 are all turned off. When the user grips the grip 4 and twists the grip load detection device 1, the piezoelectric film 51 is twisted as the housing 2 twists. This causes the piezoelectric film 51 to generate an electric charge. Therefore, the signal SigO changes when the user twists the grip load detection device 1.

[0032] First, a case where a user continues to twist the grip load detection device 1 with strong force from a no-load state will be described. Next, a case where a user continues to twist the grip load detection device 1 with strong force from a medium-load state will be described. FIG. 7 is a diagram showing an example of the change in voltage signal SigV over time. The horizontal axis in FIG. 7 represents time t. The vertical axis in FIG. 7 represents the voltage signal SigV.

[0033] When the user continues to twist the grip load detection device 1 with strong force from a no-load state, the value of the voltage signal SigV gradually increases. When the value of the voltage signal SigV exceeds a first threshold, the control circuit 721 turns on the first LED 61 while keeping the second LED 62 and the third LED 63 off (medium load first lighting pattern). Next, when the value of the voltage signal SigV exceeds a second threshold (greater than the first threshold), the control circuit 721 turns on the second LED 62 while keeping the first LED 61 emitting white light and the third LED 63 off (medium load second lighting pattern). Next, when the value of the voltage signal SigV exceeds a third threshold (greater than the second threshold), the control circuit 721 turns on the third LED 63 while keeping the first LED 61 emitting white light (medium load third lighting pattern).

[0034] Subsequently, when the value of the voltage signal SigV becomes equal to or greater than a fourth threshold (greater than the third threshold), the control circuit 721 changes the emission color of the first LED 61 from white to light blue while maintaining the second LED 62 and the third LED 63 emitting white light (medium-load fourth lighting pattern). Next, when the value of the voltage signal SigV becomes equal to or greater than a fifth threshold (greater than the fourth threshold), the control circuit 721 changes the emission color of the second LED 62 from white to light blue while maintaining the first LED 61 emitting light blue light and the third LED 63 emitting white light (medium-load fifth lighting pattern). Next, when the value of the voltage signal SigV becomes equal to or greater than a sixth threshold (greater than the fifth threshold), the control circuit 721 changes the emission color of the third LED 63 from white to light blue while maintaining the first LED 61 and the second LED 62 emitting light blue light (medium-load sixth lighting pattern).

[0035] 6 , the control circuit 721 changes the light color of the first LED 61, the second LED 62, or the third LED 63 based on the voltage signal SigV. When the value of the voltage signal SigV becomes equal to or greater than a thirteenth threshold TH13 corresponding to the maximum load, the control circuit 721 causes the first LED 61, the second LED 62, and the third LED 63 to emit red light (maximum load lighting pattern). Note that the thirteenth threshold TH13 is greater than any of the first to twelfth thresholds.

[0036] That is, the control circuit 721 switches the lighting pattern of the light emitter 6 in stages from a no-load lighting pattern to a maximum-load lighting pattern in accordance with the value of the voltage signal SigV. The shortest processing time required to switch in stages from the no-load lighting pattern to the maximum-load lighting pattern is defined as a first shortest processing time T1. If the shortest processing time required for each switching of the lighting pattern is defined as T0, then T1 = 13 × T0.

[0037] As shown in FIG. 7 , assume that the value of the voltage signal SigV exceeds the thirteenth threshold value TH13 at time TI1. If the user continues to twist the grip load detection device 1 with a strong force corresponding to an output greater than the load magnitude corresponding to the thirteenth threshold value TH13, the lighting pattern of the light emitter 6 will change from the medium load lighting pattern to the maximum load lighting pattern at the latest between time TI1 and the first shortest processing time T1. That is, between time TI1 and the first shortest processing time T1, the first LED 61, the second LED 62, and the third LED 63 emit red light. Therefore, the light emitter 6 is lit in the maximum load lighting pattern.

[0038] When the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63. That is, when the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting body 6. In this embodiment, the predetermined time is the sum of a first shortest processing time T1 required to gradually switch from the no-load lighting pattern to the maximum-load lighting pattern and a predetermined standby time T2.

[0039] When the light-emitting body 6 goes out even though the user continues to twist the grip load detection device 1, the user recognizes that something is wrong with the grip load detection device 1 and reduces the force with which the user twists the grip load detection device 1. Note that the control circuit 721 may turn off the power to the grip load detection device 1 when the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold value TH13 for a predetermined period of time or more. In this case, the light-emitting body 6 also goes out.

[0040] Next, a case where a user continues to twist the grip load detection device 1 with strong force from an intermediate load state will be described. As an example of an intermediate load state, a case where a user continues to twist the grip load detection device 1 with strong force from an intermediate load tenth lighting pattern state will be described. FIG. 8 is a diagram showing an example of a change in the voltage signal SigV over time. The horizontal axis in FIG. 8 represents time t. The vertical axis in FIG. 8 represents the voltage signal SigV. Note that the intermediate load state is not limited to the intermediate load tenth lighting pattern state, and may be any of the intermediate load first lighting pattern to the intermediate load ninth lighting pattern, the intermediate load eleventh lighting pattern, and the intermediate load twelfth lighting pattern.

[0041] In the state of the medium load tenth lighting pattern, the value of the voltage signal SigV is greater than the tenth threshold and less than the eleventh threshold. In the state of the medium load tenth lighting pattern, the control circuit 721 causes the first LED 61 to emit pink light and the second LED 62 and the third LED 63 to emit green light.

[0042] When the user continues to twist the grip load detection device 1 from the medium load 10th lighting pattern state with a strong force equivalent to an output greater than the load magnitude corresponding to the 13th threshold TH13, the value of the voltage signal SigV gradually increases.

[0043] 8 , assume that the value of the voltage signal SigV becomes equal to or greater than the thirteenth threshold value TH13 at time TI2. The control circuit 721 gradually switches the lighting pattern of the light-emitting body 6 from the medium-load tenth lighting pattern to the maximum-load lighting pattern in accordance with the value of the voltage signal SigV. If the user continues to twist the grip load detection device 1 with a strong force corresponding to an output greater than or equal to the load magnitude corresponding to the thirteenth threshold value TH13, the lighting pattern of the light-emitting body 6 will transition from the medium-load lighting pattern to the maximum-load lighting pattern at the latest within the first shortest processing time T1 from time TI2.

[0044] When the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63. That is, when the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting body 6. As described above, in this embodiment, the predetermined time is the sum of the first shortest processing time T1 required to gradually switch from the no-load lighting pattern to the maximum-load lighting pattern and the predetermined standby time T2.

[0045] Even though the user continues to twist the grip load detection device 1, the light-emitting element 6 goes out, causing the user to realize that something is wrong with the grip load detection device 1 and reduce the force with which the user twists the grip load detection device 1.

[0046] When the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting body 6. As a result, even though the user continues to twist the grip load detection device 1, the user recognizes that there is something wrong with the grip load detection device 1 because the light-emitting body 6 has turned off, and reduces the force with which the user twists the grip load detection device 1. Therefore, the grip load detection device 1 can prevent excessive load from being continuously applied to the grip load detection device 1.

[0047] Furthermore, the control circuit 721 gradually switches the lighting pattern of the light-emitting body 6 from a no-load lighting pattern to a maximum-load lighting pattern according to the value of the voltage signal SigV. As a result, if the user is twisting the grip load detection device 1 correctly, the lighting pattern of the light-emitting body 6 changes as the user expects, depending on the magnitude of the load on the housing 2. Therefore, the user can recognize that they are twisting the grip load detection device 1 correctly. Furthermore, if the user is not twisting the grip load detection device 1 correctly, the load on the housing 2 is not applied correctly, and the lighting pattern of the light-emitting body 6 does not change as the user expects. Therefore, the user can recognize that they are not twisting the grip load detection device 1 correctly. As a result, the grip load detection device 1 allows the user to recognize whether they are twisting the grip load detection device 1 correctly.

[0048] Furthermore, even if a user continues to twist the grip load detection device 1 with a strong force equivalent to an output greater than or equal to the load magnitude corresponding to the thirteenth threshold TH13, the lighting pattern of the light-emitting element 6 will change from the medium-load lighting pattern to the maximum-load lighting pattern at the latest between time TI1 or TI2 when the value of the voltage signal SigV becomes equal to or greater than the thirteenth threshold TH13 and the first shortest processing time T1. Therefore, if the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting element 6. The predetermined time is the sum of the first shortest processing time T1 required to gradually switch from the no-load lighting pattern to the maximum-load lighting pattern and the predetermined waiting time T2. This allows the user to more reliably determine whether the grip load detection device 1 is being twisted correctly and prevents the grip load detection device 1 from being continuously subjected to excessive load.

[0049] It should be noted that each of the first to thirteenth thresholds TH13 may be a value having hysteresis. Fig. 9 is a diagram showing an example of the thirteenth threshold TH13 having hysteresis. Fig. 10 is a diagram showing an example of the change over time of the voltage signal SigV. The horizontal axis in Fig. 9 represents the voltage signal SigV. The vertical axis in Fig. 9 represents the lighting pattern of the light-emitting body 6. The horizontal axis in Fig. 10 represents time t. The vertical axis in Fig. 10 represents the voltage signal SigV. Below, a case where hysteresis is provided in the thirteenth threshold TH13 will be described.

[0050] When the value of the voltage signal SigV fluctuates near the threshold value in a short period of time, the lighting pattern of the light-emitting element 6 is frequently switched, causing fluctuations in the lighting of the light-emitting element 6. The fluctuations in the lighting of the light-emitting element 6 mean that the light-emitting element 6 repeatedly turns on and off in a short period of time, or that the light color of the light-emitting element 6 changes in a short period of time.

[0051] 9 , the thirteenth threshold TH13 has a thirteenth upper threshold TH13U and a thirteenth lower threshold TH13D. The thirteenth upper threshold TH13U is greater than the thirteenth lower threshold TH13D. The lighting pattern of the light emitter 6 does not switch from the medium-load twelfth lighting pattern to the maximum-load lighting pattern even when the voltage signal SigV becomes equal to or greater than the thirteenth lower threshold TH13D. However, when the voltage signal SigV becomes equal to or greater than the thirteenth upper threshold TH13U, the lighting pattern of the light emitter 6 switches from the medium-load twelfth lighting pattern to the maximum-load lighting pattern.

[0052] Furthermore, even if the voltage signal SigV falls below the 13th upper threshold TH13U, the light emitter 6 does not switch from the maximum load lighting pattern to the medium load 12th lighting pattern, but switches from the maximum load lighting pattern to the medium load 12th lighting pattern when the voltage signal SigV falls below the 13th lower threshold TH13D.

[0053] Therefore, even if the value of the voltage signal SigV fluctuates near the 13th upper threshold TH13U or near the 13th lower threshold TH13D in a short period of time, the lighting pattern of the light emitter 6 does not change frequently, and fluctuations in the lighting of the light emitter 6 can be suppressed.

[0054] 10 , assume that the value of the voltage signal SigV becomes equal to or greater than the thirteenth upper threshold TH13U at time TI3. ​​When the value of the voltage signal SigV becomes equal to or greater than the thirteenth upper threshold TH13U, the control circuit 721 gradually switches the lighting pattern of the light-emitting element 6 from the no-load lighting pattern to the maximum-load lighting pattern. If the user continues to twist the grip load detection device 1 with a strong force corresponding to an output greater than or equal to the load magnitude corresponding to the thirteenth lower threshold TH13D, the lighting pattern of the light-emitting element 6 will transition through the intermediate-load lighting pattern and then to the maximum-load lighting pattern at the latest within the first shortest processing time T1 from time TI3.

[0055] When the value of the voltage signal SigV remains equal to or greater than the thirteenth lower threshold TH13D for a predetermined time or longer, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63. In other words, when the value of the voltage signal SigV remains equal to or greater than the thirteenth lower threshold TH13D for a predetermined time or longer, the control circuit 721 turns off the light-emitting element 6.

[0056] Even though the user continues to twist the grip load detection device 1, the light-emitting element 6 goes out, causing the user to realize that something is wrong with the grip load detection device 1 and reduce the force with which the user twists the grip load detection device 1.

[0057] When the thirteenth threshold TH13 has a hysteresis value, after the value of the voltage signal SigV becomes equal to or greater than the thirteenth upper threshold TH13U, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63, even if the value of the voltage signal SigV remains below the thirteenth upper threshold TH13U and equal to or greater than the thirteenth lower threshold TH13D for a predetermined period of time or more. Therefore, compared to when the thirteenth threshold TH13 has only the thirteenth upper threshold TH13U, even if the user continues to twist the grip load detection device 1 with weak force, the user recognizes an abnormality in the grip load detection device 1 when the light-emitting body 6 is turned off and reduces the force with which they twist the grip load detection device 1. Therefore, when the thirteenth threshold TH13 has a hysteresis value, continuous application of excessive load to the grip load detection device 1 can be more effectively prevented.

[0058] Furthermore, since the notification unit includes an LED, the user can visually recognize an abnormality in the grip load detection device 1. Therefore, the user can easily recognize an abnormality in the grip load detection device 1. As a result, the grip load detection device 1 can more reliably prevent an excessive load from being continuously applied to the grip load detection device 1.

[0059] The sensor 5 also includes a piezoelectric film 51. Piezoelectric films are excellent at detecting dynamic strain. Therefore, even if a user twists the grip load detection device 1 with a strong force in a short period of time, the piezoelectric film 51 generates an electric charge immediately due to deformation. Therefore, the grip load detection device 1 can detect even an excessive load that lasts for a short period of time.

[0060] Furthermore, the signal SigO, which is the output signal of the sensor 5, changes when the user twists the grip load detection device 1. Therefore, the user can use the grip load detection device 1 as a fitness tool that applies a twisting motion.

[0061] Furthermore, the static friction coefficient of the surface of the grip 4 is greater than the static friction coefficient of the surface of the housing 2. In other words, the surface of the grip 4 is less slippery than the surface of the housing 2. Therefore, the user can easily grip the grip 4 compared to gripping the housing 2. Silicone rubber, which is less likely to react or deteriorate when it comes into contact with the user's skin, can be considered as a material for the non-slip grip 4. However, silicone rubber has the characteristic of being difficult to bond or adhere. Therefore, if the grip 4 is provided at both ends of the housing 2 in the first direction DIR1, continuous application of excessive load to the grip load detection device 1 may cause the grip 4 to detach from the housing 2 and spin freely. However, the grip load detection device 1 can prevent continuous application of excessive load to the grip load detection device 1, thereby preventing the grip 4 from detaching from the housing 2. As a result, silicone rubber can be used as the material for the grip 4.

[0062] [First Modification] A grip load detection device 1a according to a first modification of the present invention will be described below with reference to the drawings. Fig. 11 is a diagram showing an example of a change in voltage signal SigV over time. The horizontal axis in Fig. 11 represents time t. The vertical axis in Fig. 11 represents voltage signal SigV. Note that with regard to the grip load detection device 1a, only the differences from the grip load detection device 1 will be described, and the rest will be omitted.

[0063] The grip load detection device 1a differs from the grip load detection device 1 in that the specified time is the sum of a second shortest processing time T3 required to gradually switch from the medium load lighting pattern to the maximum load lighting pattern and a specified waiting time T2.

[0064] A case where a user continues to twist the grip load detection device 1a with strong force from a medium load state will be described. As an example of a medium load state, a case where a user continues to twist the grip load detection device 1a with strong force from a medium load state of the tenth lighting pattern will be described.

[0065] As shown in FIG. 11 , if the user continues to twist the grip load detection device 1a after time TI2 with a strong force equivalent to an output greater than or equal to the load magnitude corresponding to the thirteenth threshold TH13, the lighting pattern of the light-emitting element 6 will change from the medium-load lighting pattern to the maximum-load lighting pattern at the latest between time TI2 and the second shortest processing time T3. In this modification, the second shortest processing time T3 is the time required to gradually switch from the medium-load tenth lighting pattern, which is the lighting pattern at time TI2, to the maximum-load lighting pattern. The lighting pattern is switched three times to gradually switch from the medium-load tenth lighting pattern to the maximum-load lighting pattern. That is, when the second shortest processing time T3 is expressed using the shortest switching processing time T0 required for each switching of the lighting pattern, T3 = 3 × T0. In addition, if the lighting pattern at time TI2 is an intermediate load lighting pattern other than the intermediate load 10th lighting pattern, the second shortest processing time T3 may be the time required to gradually switch from the intermediate load lighting pattern to the maximum load lighting pattern.

[0066] When the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the first LED 61, the second LED 62, and the third LED 63. That is, when the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting element 6. In this modification, the predetermined time is the sum of the second shortest processing time T3 required for gradually switching from the medium-load tenth lighting pattern, which is the lighting pattern at time TI2, to the maximum-load lighting pattern, and the predetermined standby time T2.

[0067] The grip load detection device 1a achieves the same effect as the grip load detection device 1. Furthermore, even if a user continues to twist the grip load detection device 1a with strong force, the lighting pattern of the light-emitting element 6 will change from the intermediate load lighting pattern to the maximum load lighting pattern at the latest between time TI2 when the value of the voltage signal SigV becomes equal to or greater than the thirteenth threshold value TH13 and the second shortest processing time T3. Therefore, if the value of the voltage signal SigV remains equal to or greater than the thirteenth threshold value TH13 for a predetermined time or longer, the control circuit 721 turns off the light-emitting element 6. The predetermined time is the sum of the second shortest processing time T3 required to gradually switch from the intermediate load tenth lighting pattern to the maximum load lighting pattern and the predetermined waiting time T2. The second shortest processing time T3 is shorter than the first shortest processing time T1. Therefore, the grip load detection device 1a turns off the light-emitting element 6 earlier than the grip load detection device 1. This allows the user to more quickly recognize an abnormality in the grip load detection device 1 a and reduce the force with which the grip load detection device 1 a is twisted, thereby more effectively preventing excessive load from being continuously applied to the grip load detection device 1 a.

[0068] Other Embodiments The grip load detection device according to the present invention is not limited to the grip load detection device 1, 1a, and can be modified within the scope of the gist thereof.

[0069] The predetermined time according to the present invention is not limited to the above-mentioned time.

[0070] For example, if the lighting pattern of the light-emitting element 6 is the medium load 12th lighting pattern at time TI1, TI2 or TI3, the lighting pattern of the light-emitting element 6 may be only the maximum load lighting pattern from time TI1, TI2 or TI3 onwards.

[0071] The lighting pattern of the light-emitting element 6 is not limited to the above-described embodiment and modified examples. For example, the control circuit 721 may cause the light-emitting element 6 to flash as a maximum load notification pattern when the value of the voltage signal SigV exceeds a threshold corresponding to the maximum load. The notification unit according to the present invention is not limited to an LED, but may also be a sound-producing element such as a buzzer. For example, the sound-producing element may have multiple sound-producing patterns corresponding to the magnitude of the load on the housing 2. For example, the greater the load on the housing 2, the higher the frequency of the sound produced by the sound-producing element. For example, the control circuit 721 may gradually increase the frequency of the sound produced by the sound-producing element when the value of the voltage signal SigV exceeds a threshold corresponding to the maximum load, and stop the sound produced by the sound-producing element when the value of the voltage signal SigV remains above the threshold for a predetermined period of time. The notification unit according to the present invention may be a combination of a light-emitting element and a sound-producing element.

[0072] Since the grip load detection device 1, 1a is a fitness tool for a user to apply a twisting motion, the uniaxial direction OD of the piezoelectric body is set to an angle for detecting the twist of the piezoelectric film 51. The grip load detection device according to the present invention may be used by a user to apply a bending motion. In this case, the uniaxial direction OD may form an angle of 45 degrees with respect to the left-right direction when viewed in the up-down direction. This 45 degrees includes approximately 45 degrees ±10 degrees.

[0073] The sensor according to the present invention is not limited to the sensor 5, but may be any sensor whose electrical characteristics change with deformation. An example of a sensor whose electrical characteristics change with deformation is a strain gauge. The electrical resistance value of a strain gauge changes with deformation. That is, the electrical characteristics of a strain gauge change with deformation.

[0074] The present invention has the following configuration.

[0075] (1) A grip load detection device comprising: an elastic housing; a sensor attached to the housing and whose electrical characteristics change with deformation; a notification unit having a plurality of notification patterns according to the magnitude of the load on the housing; and a control circuit that switches the notification pattern based on an output signal of the sensor, wherein the plurality of notification patterns include a no-load notification pattern corresponding to no load and a maximum load notification pattern corresponding to a maximum load, and the control circuit switches the notification pattern in stages from the no-load notification pattern to the maximum load notification pattern according to the value of the output signal, and stops notification from the notification unit when the value of the output signal remains above a threshold for a predetermined time or more.

[0076] (2) The grip load detection device according to (1), wherein the predetermined time is the sum of a first shortest processing time T1 required to gradually switch from the no-load notification pattern to the maximum-load notification pattern and a predetermined waiting time T2.

[0077] (3) The grip load detection device described in (1), wherein the plurality of notification patterns include an intermediate load notification pattern corresponding to an intermediate load that is greater than no load and less than the maximum load, and the predetermined time is the sum of a second shortest processing time T3 required to gradually switch from the intermediate load notification pattern to the maximum load notification pattern and a predetermined waiting time T2.

[0078] (4) The grip load detection device according to any one of (1) to (3), wherein the threshold value is a value having hysteresis.

[0079] (5) The grip load detection device according to any one of (1) to (4), wherein the notification unit includes an LED, the maximum load notification pattern is lighting up the LED, and the control circuit turns off the LED when the value of the output signal remains equal to or greater than the threshold value for a predetermined period of time.

[0080] (6) The grip load detection device according to any one of (1) to (5), wherein the sensor includes a piezoelectric film, the piezoelectric film has polylactic acid stretched in at least one axial direction, the piezoelectric film has a rectangular main surface when unfolded on a plane, and the one axial direction forms an angle of 0 degrees or 90 degrees with respect to the longitudinal direction of the main surface when viewed from above when the piezoelectric film is unfolded on a plane.

[0081] (7) The grip load detection device according to any one of (1) to (6), wherein the output signal changes when a user twists the housing.

[0082] (8) The grip load detection device according to (7), further comprising a grip, wherein the static friction coefficient of the surface of the grip is greater than the static friction coefficient of the surface of the housing, the housing has a shape extending along a first direction, and the grip is provided at both ends of the housing in the first direction.

[0083] 1, 1a: grip load detection device 2: housing 3: cover 4: grip 5: sensor 6: light emitting body 7: circuit board 8: adhesive member 51: piezoelectric film 52: first electrode 53: first adhesive 54: second adhesive 55: second electrode 61: first LED 62: second LED 63: third LED 71: detection circuit 72: MPU 521: first base material 522: first conductive film 551: second base material 552: second conductive film 721: control circuit 722: memory CA: central axis DIR1: first direction DIR2: second direction DS51: lower main surface IS2: inner surface OD: uniaxial direction OS2: outer surface S1: first section S2: second section SigC1 to SigC3: control signal SigO: signal SigV: voltage signal TH13: 13th threshold TH13D: 13th lower threshold TH13U: 13th upper threshold US51: upper principal surface

Claims

1. A grip load detection device comprising: an elastic housing; a sensor attached to the housing and whose electrical characteristics change with deformation; a notification unit having a plurality of notification patterns according to the magnitude of the load on the housing; and a control circuit that switches the notification pattern based on an output signal of the sensor, wherein the plurality of notification patterns include a no-load notification pattern corresponding to no load and a maximum load notification pattern corresponding to a maximum load, and the control circuit switches the notification pattern in stages from the no-load notification pattern to the maximum load notification pattern according to the value of the output signal, and stops notification from the notification unit when the value of the output signal remains above a threshold for a predetermined period of time or more.

2. The grip load detection device according to claim 1, wherein the predetermined time is the sum of a first shortest processing time T1 required to gradually switch from the no-load notification pattern to the maximum load notification pattern and a predetermined waiting time T2.

3. The grip load detection device of claim 1, wherein the plurality of notification patterns include an intermediate load notification pattern corresponding to an intermediate load greater than no load and less than the maximum load, and the predetermined time is the sum of a second shortest processing time T3 required to gradually switch from the intermediate load notification pattern to the maximum load notification pattern and a predetermined waiting time T2.

4. The grip load detection device according to any one of claims 1 to 3, wherein the threshold value is a value having hysteresis.

5. A grip load detection device as described in any one of claims 1 to 4, wherein the notification unit includes an LED, the maximum load notification pattern is lighting up the LED, and the control circuit turns off the LED when the value of the output signal remains above the threshold for a predetermined period of time or more.

6. A grip load detection device as described in any one of claims 1 to 5, wherein the sensor includes a piezoelectric film, the piezoelectric film having polylactic acid stretched in at least one axial direction, the piezoelectric film having a rectangular main surface when unfolded on a plane, and the one axial direction forms an angle of 0 degrees or 90 degrees with respect to the longitudinal direction of the main surface when viewed in a plane, when the piezoelectric film is unfolded on a plane.

7. The grip load detection device according to any one of claims 1 to 6, wherein the output signal changes when a user twists the housing.

8. A grip load detection device as described in claim 7, further comprising a grip, the static friction coefficient of the surface of the grip being greater than the static friction coefficient of the surface of the housing, the housing having a shape extending along a first direction, and the grips being provided at both ends of the housing in the first direction.

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