JP2007304085A - Pressure detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem with a conventional linear pressure detector in which it can detect presence/absence of pressure application, but cannot detect a place to which pressure application is performed. <P>SOLUTION: This pressure detector comprises two linear pressure response means 9a and 9b adjacently disposed, the pressure response means having different sensitivities for each longitudinal position of a pressure sensing means. When an external pressure is applied, the place to which the pressure application is performed can be specified from the ratio of response voltage of the pressure response means 9a and 9b since the ratio is differed for each place coordinate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pressure detection device that detects pressure from the outside using a flexible pressure sensitive body.

  Conventionally, there is such a pressure detection device as shown in FIG. As shown in a cross-sectional view in FIG. 22, the electrode 2 is formed on the upper and lower sides of the flexible pressure-sensitive body 1, and the sheet-like laminated structure is covered with the protective layer 3. In FIG. 22, the direction of remanent polarization in the flexible pressure-sensitive body 1 is not shown, but normally, in order to perform a polarization operation by applying a high voltage between the electrodes 2, the direction is perpendicular to the surface of the electrode 2. Residual polarization is formed.

  As the flexible pressure-sensitive body 1, a composite in which a piezoelectric ceramic powder such as lead titanate or lead zirconate titanate is added to synthetic rubber or synthetic resin is used. The electrode 2 is configured by bonding a metal foil such as copper, aluminum, or gold to the flexible pressure-sensitive body 1 with an adhesive or the like, or depositing the above metal.

  When pressure is applied to the pressure detection device from the outside, the flexible pressure-sensitive body 1 is distorted with acceleration, and at the same time, a voltage is generated due to the piezoelectric effect. This voltage is applied to the response voltage via the two electrodes 2. As a result, the pressure is detected.

  Moreover, there exists a cable-shaped thing as shown in FIG. 23 as a conventionally known pressure detection apparatus (for example, refer patent document 1). 23A shows a cross section in the longitudinal direction of the cable, and FIG. 23B shows a cross section taken along the line AA in FIG. Specifically, the inner electrode 4 is formed at the center, the flexible pressure-sensitive body 1 is formed around the inner electrode 4, and the outer electrode 5 and the protective layer 3 are sequentially formed on the outer side. In FIG. 23, the direction of remanent polarization in the flexible pressure-sensitive body 1 is not shown. Usually, in order to perform a polarization operation by applying a high voltage between the internal electrode 4 and the external electrode 5, the internal electrode Residual polarization is formed radially from 2 to the external electrode 5.

  For the flexible pressure-sensitive body 1 in FIG. 23, a composite using the same material as that of the sheet-like flexible pressure-sensitive element is used. For the internal electrode 4, a linear conductive material in which a conductor such as metal is linear is used. Further, the external electrode 5 is formed by applying a conductive paint such as a silver-based rubber paint on the surface of the flexible pressure-sensitive body 1. Similar to the sheet-like flexible pressure sensitive element, the pressure is detected by measuring, as a response voltage, a potential difference generated due to strain accompanying acceleration due to application of dynamic pressure.

  Here, the definition of the pressure used in this specification will be described. The pressure includes a dynamic pressure and a static pressure. Unless otherwise specified, “pressure” as used herein means a dynamic pressure. Hereinafter, the difference between the dynamic pressure and the static pressure will be described by focusing on the difference in generated voltage when applied to the flexible pressure sensitive body.

  The dynamic pressure is a pressure that is not balanced with the stress from the applied object. As a result, the object to which the dynamic pressure is applied is deformed with acceleration. On the other hand, the static pressure is a pressure that perfectly balances the stress from the applied object, and as a result, the object to which the static pressure is applied is not deformed with acceleration.

For this reason, only when dynamic pressure is applied, the flexible pressure-sensitive body is distorted with acceleration and changes in voltage due to the piezoelectric effect.
JP-A-62-230071

  However, the conventional pressure detection device has a problem that the location where the pressure is applied cannot be detected because the same voltage change occurs regardless of which portion of the flexible pressure sensitive body is applied with the pressure.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a pressure detection device capable of detecting a place where pressure is applied in addition to detecting the presence or absence of external pressure application. .

  In order to solve the conventional problems, the pressure detection device of the present invention measures a potential difference generated in the flexible pressure sensitive body and the flexible pressure sensitive body as a response voltage when pressure is applied from the outside. A linear pressure response means including an electrode for pressure and a pressure determination means for determining whether external pressure is applied to the pressure response means. A plurality of the pressure response means are arranged adjacent to each other. And the plurality of pressure response means have a plurality of response voltages different from each other at different locations when a constant pressure is applied from the outside.

  Since the sensitivities of the plurality of pressure response means are different from each other at each place where the pressure is applied, the place where the pressure is applied is determined from the relationship of the magnitude of the response voltage generated in the plurality of pressure response means when a pressure is applied. It becomes possible to specify.

  According to the pressure detection device of the present invention, in addition to the presence or absence of external pressure application, it is possible to detect the place where the pressure is applied.

  A pressure detection device according to a first aspect of the invention includes a linear pressure sensor and an electrode for measuring a potential difference generated in the flexible pressure sensor as a response voltage when pressure is applied from the outside. Pressure response means, and pressure determination means for determining the presence or absence of external pressure application to the pressure response means, a plurality of the pressure response means being arranged adjacent to each other, The response voltage of the pressure response means has different location coordinate dependence when a constant pressure is applied from the outside, and the pressure determination means has a magnitude of response voltage having the different location coordinate dependence. From this relationship, it has a configuration for determining the location coordinates to which the external pressure is applied.

  Since the response voltages of the plurality of pressure response means have different location coordinate dependencies, when the pressure is applied from the outside, the magnitude of the response voltage generated in the plurality of pressure response means is compared to The effect of being able to specify the applied location coordinates is obtained.

  The pressure detection device according to a second invention is the pressure detection device according to the first invention, particularly in the first invention, wherein the pressure response means includes a plurality of flexible pressure sensitive bodies and a plurality of electrodes for measuring response voltages generated in the flexible pressure sensitive bodies. And the pressure response means has response voltages having different location coordinate dependencies corresponding to the plurality of flexible pressure sensitive bodies when a constant pressure is applied from the outside. Have

  Even when the number of pressure response means is small and there is only one, it is possible to determine the presence / absence of pressure application and the coordinates of the application location, and the effect of facilitating manufacture and arrangement can be obtained.

  In the pressure detection device of the third invention, in particular, in either the first or second invention, a response voltage generated when a constant pressure is applied to the pressure response means from the outside is one of the pressure response means. It has a configuration that changes monotonically from one end to the other end.

  By combining the ones whose response voltage changes monotonously, it is possible to easily realize a configuration in which the relationship of the response voltage at each location coordinate is different. In addition, manufacturing a device whose response voltage changes monotonously is simpler than manufacturing a device having a response voltage that varies in a complicated manner for each location coordinate, so that an effect of facilitating manufacturing can be obtained.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the invention, the piezoelectric constants of the plurality of flexible pressure-sensitive bodies constituting the pressure response means have different location coordinate dependencies. The plurality of response voltages of the pressure response means have different location coordinate dependencies.

  Since changing the piezoelectric constant for each location coordinate is easy by adjusting the polarization voltage and time, the effect of easily obtaining the pressure response means of the present invention can be obtained.

  In the pressure detection device of the fifth invention, in particular, in any one of the first to fourth inventions, a protective layer is formed to protect the pressure response means, and the thickness of the protective layer has location coordinate dependency. The plurality of response voltages of the pressure response means have different location coordinate dependencies.

  Even when a flexible pressure-sensitive body has already been manufactured, the response voltage at each location coordinate can be changed due to the difference in the protective layer, so that an effect of facilitating the change of the specification can be obtained.

  The pressure detection device according to a sixth aspect of the present invention is the pressure detection device according to any one of the first to fifth aspects, wherein the pressure determination means has different location coordinate dependencies when determining the location coordinates to which pressure is applied from the outside. The determination is made by calculating a response voltage ratio from a plurality of different response voltages.

  The response voltage ratio can be obtained by simple calculation, and the effect of reducing the cost of the pressure determination means by reducing the load of the pressure determination means can be obtained. In addition, the response voltage varies depending on moisture and temperature, but by taking the ratio of the response voltages, they are canceled out, and the effect of more accurately determining the location coordinates where the pressure is applied can be obtained.

  The pressure detection device according to a seventh aspect of the invention has a configuration in which the pressure response means is a cable-like pressure response means, particularly in any one of the first to sixth inventions.

  Since the production can be performed by a continuous extrusion process, an effect of facilitating the production can be obtained.

  In the pressure detection device according to the eighth invention, in particular, in the seventh invention, the cable-like pressure response means may be in close contact with the internal electrode located at the approximate center of the cable-like pressure response means and the internal electrode. A flexible pressure-sensitive body and an external electrode in close contact with the flexible pressure-sensitive body are included, and the internal electrode and the external electrode are used for measuring a response voltage.

  Since it is cable-shaped and symmetrical with respect to the center, the remanent polarization is formed radially from the center. For this reason, isotropic detection is possible with respect to pressure application from any direction. Therefore, even when the pressure response means is rotated or twisted during installation, the response voltage hardly changes. As a result, the degree of freedom of arrangement is increased, and the effect of enabling stable pressure application and stable location coordinate detection can be obtained.

  The pressure detection device according to a ninth aspect of the present invention is the pressure detection device according to any one of the first to eighth aspects, further comprising a pressure transmission unit that transmits a pressure from the outside to the plurality of pressure response means, and each pressure response of the pressure transmission unit. The elastic modulus of the portion in contact with the means has a configuration having location coordinate dependency.

  Since the elastic modulus of the portion in contact with each pressure response means varies depending on the location coordinates, the force transmitted to each pressure response means varies depending on the location when pressure is applied from the outside. As a result, the response voltage generated in each pressure response means has a different location coordinate dependency, and by comparing the magnitude of the response voltage generated in multiple pressure response means, the place where pressure is applied An effect that allows the coordinates to be specified is obtained.

  There is no need to adjust the piezoelectric constant of the flexible pressure-sensitive body of the pressure response means for each location or to adjust the thickness of the protective layer. Therefore, an effect that the manufacture of the pressure response means is facilitated can be obtained. By adjusting the elastic modulus of the portion in contact with the pressure response means, it is possible to obtain the location dependence of the desired response voltage, so that the degree of freedom in design is increased and the effect of being easily adaptable to changes in specifications is also obtained.

  A pressure detection device according to a tenth aspect of the invention has a configuration in which, in particular, in any one of the first to ninth aspects, the plurality of pressure response means are the same type of pressure response means.

  Since the pressure response means having the same shape and the same size, material, and manufacturing process can be used, the manufacturing efficiency of the pressure response means is significantly improved.

  The pressure detection device according to an eleventh aspect of the present invention has a configuration in which, in particular, in any one of the first to tenth aspects, a plurality of pressure transmission parts are provided at different location coordinates separated from each other on the pressure response means. Since the interaction between the pressure transmission part existing at a certain place coordinate and the pressure transmission part existing at another place coordinate becomes small, the independence of the place coordinate is increased and the effect of increasing the accuracy of the place determination is obtained. It is done.

  A pressure detection device according to a twelfth aspect of the present invention is the pressure detection device according to any one of the first to eleventh aspects, particularly in which the pressure transmission unit is integrated with the pressure transmission unit and the direction is fixed in order to maintain a certain level of horizontality. It has the structure which has a part support part.

  Since it is integrated with the pressure support fixing portion whose direction is fixed, the level of the pressure transmission portion does not change. For this reason, the variation of the response voltage generated when pressure is applied from the outside is reduced, and the effect of increasing the accuracy of location detection can be obtained.

  A pressure detection device according to a thirteenth aspect of the present invention is the support fixing portion partition wall in which the support fixing portion for fixing the pressure response means fixes the plurality of pressure response means without contacting, particularly in any one of the first to twelfth inventions. It has the composition which has.

  By having the support fixing part partition wall, the positional deviation of the pressure response means is suppressed, the variation of the response voltage is reduced, and the location detection accuracy is increased.

  Further, since the pressure response means is not excessively compressed by the partition wall, an effect of suppressing deterioration such as plastic deformation of the pressure response means is obtained when an excessive pressure is applied from the outside.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic diagram of a pressure detection device according to a first embodiment of the present invention. First, the configuration and the outline of the operation will be described using this. FIG. 1A is a schematic view seen from above, and FIG. 1B is a cross-sectional view taken along the line BB.

  As shown in FIG. 1, the pressure detection device 8 includes two pressure response means 9 a and 9 b and one pressure determination means 10. The two pressure response means 9a and 9b are installed adjacent to each other. At this time, it is preferable that the pressure response means 9a and 9b be installed adjacent to a narrower range than the region to which the pressure is applied so that the pressure from the outside is applied in the same manner. Further, if necessary, a pressure transmission unit 6 that receives pressure from the outside and transmits the pressure to the pressure response means 9a and 9b is provided on the two pressure response means 9 shown in FIG. It has the action of transmitting pressure evenly to the pressure response means. In this state, when pressure is applied from the outside, the pressure is transmitted to the pressure response means 9a, 9b through the pressure transmission unit 6, and a voltage difference is generated between the electrodes corresponding to the pressure response means 9a, 9b. Using this potential difference as a response voltage, the pressure determination means 10 independently measures the presence / absence of pressure application and the location coordinates where the pressure is applied.

  The pressure response means 9 shown in FIG. 1 is a linear pressure response means, and a cable-like one is described as an example, but in addition, depending on the shape of the flexible pressure-sensitive body and how to take the electrodes Further, a tape-like form corresponding to FIG. 22 can be taken, and the form is not particularly limited thereto.

  However, in the following embodiment, as shown in FIG. 1, a cable-like linear pressure response means will be described as an example. This is because the following effects can be obtained.

  Since the cable-like linear pressure response means can be manufactured in a continuous extrusion process, the effect of facilitating the manufacture can be obtained. Further, since the cable has a centrally symmetric structure, the remanent polarization is formed radially from the center. For this reason, isotropic detection is possible with respect to pressure application from any direction. Therefore, even when the pressure response means rotates or twists during installation, the response voltage hardly changes. As a result, the degree of freedom of arrangement is increased, and the effect of enabling the determination of the presence or absence of stable pressure application and the stable location coordinate determination can be obtained.

  FIG. 2 is a detailed cross-sectional view corresponding to FIG. 1 of the pressure detection device 8 according to the first embodiment of the present invention. 2A is a diagram showing a cross-sectional view in the longitudinal direction of the pressure response means 9 configured in a cable shape and a pressure calculation means, and FIG. 2B is a position along the line CC in FIG. FIG. In FIG. 2A, for simplicity, only one cross section of the two pressure response means 9a and 9b is shown, but the other cross section has a similar structure.

  As can be seen from FIG. 2, each of the pressure response means 9 a and 9 b is provided with a flexible pressure-sensitive body 11 around the internal electrode 14, an external electrode 12 on the outside thereof, and a protective layer 13 on the outside thereof. Configured. Above the pressure response means 9a, 9b, the pressure transmission unit 6 already described is provided. In addition, a support fixing portion 7 is provided in the lower portion to support and fix the whole. Of course, when sufficient strength is ensured, the protective layer 13 is not necessarily required, and Po in the figure indicates the pressure applied from the outside.

The flexible pressure sensitive body 11 is configured by dispersing piezoelectric ceramic powder in synthetic rubber or synthetic resin. As the synthetic rubber or synthetic resin, a thermoplastic resin such as vinyl chloride, a thermoplastic elastomer such as chlorinated polyethylene, a vulcanized rubber such as EPDM, or the like is used. Also, as piezoelectric ceramics, lead titanate, lead zircon, lead zirconate titanate, barium titanate, bismuth sodium sodium titanate, bismuth sodium titanate-barium titanate,
A ceramic material exhibiting piezoelectricity such as a compound having a perovskite structure such as alkali niobate, a compound having a bismuth layer structure, or a compound having a tungsten bronze structure is used.

  The protective layer 13 is made of a synthetic rubber or a synthetic resin used for the flexible pressure-sensitive body 11, and is made of at least one of a thermoplastic resin, a thermoplastic elastomer, and a vulcanized rubber, but wear and charge leakage are reduced. If it is, it is not particularly necessary.

  As the external electrode 12, a wire material such as C, Pt, Au, Pd, Ag, Cu, Al, Ni, stainless steel, or the like obtained by rolling a wire material into a flat tape shape or the like is used. Alternatively, if the tape-like polymer film laminated with the metal wire or the tape-like wire is used, a more flexible external electrode can be obtained. Moreover, the electrode which covered the flexible pressure-sensitive body 11 by knitting a metal fine wire independently can also be used.

  As the internal electrode 14, one or a plurality of fine metal wires used in the external electrode 12, a plurality of fibers such as polyester wound around the metal wire, or the like is used.

  Further, regarding the flexible pressure-sensitive body 11, the protective layer 13, and the external electrode 12, the same can be applied to the following embodiments.

  Next, a general example will be described regarding the manufacturing method of the cable-like pressure response means.

  First, a piezoelectric ceramic powder and a thermoplastic elastomer as a synthetic rubber or a synthetic resin are kneaded to form a composite. Next, the composite is extruded together with the internal electrode using an extruder, thereby obtaining a cable having the flexible electrode 11 made of the composite formed around the internal electrode 14. Further, a polarization electrode covering the periphery of the cable is prepared, and by applying a voltage between this electrode and the internal electrode 14 in the cable, an electric field is formed radially from the internal electrode, and a ceramic piezoelectric body in a corresponding direction Form polarization inside. Further, after removing the electrode for polarization, the external electrode 12 is formed by winding a tape-shaped metal wire, a tape-shaped metal, or a tape laminated with a tape-shaped metal and a tape-shaped polymer around the cable. To do. Next, a pressure response means is obtained by forming a protective layer 13 of the cable by extruding a thermoplastic resin, a thermoplastic elastomer, rubber or the like with an extruder around the cable on which the external electrode 12 is formed. . Polarization can also be performed by applying a voltage between the external electrode 12 and the internal electrode 14 after the external electrode 12 is formed.

  As described in the above-described polarization method, polarization can be performed by preparing a polarization electrode covering the periphery of the cable and applying a voltage between the electrode and the internal electrode 14 in the cable. This method provides an effect of facilitating the introduction of the location dependence of different response voltages for the plurality of pressure response means 9. With respect to the pressure response means 9 of the present embodiment described below, the dependence of the response voltage V on the location coordinates is introduced by this polarization method.

  Specifically, when applying the voltage at the time of polarization, the residual polarization is increased by increasing the voltage applied at each location, increasing the application time, or increasing the temperature at the time of application. Can do. Therefore, by adjusting these parameters, it is possible to adjust the dependence of the remanent polarization on the location coordinates. On the other hand, since the magnitude of the remanent polarization is proportional to the piezoelectric constant of the flexible pressure-sensitive body 11 and the piezoelectric constant is proportional to the response voltage V, the location of the piezoelectric constant of the flexible pressure-sensitive body 11 is determined by the polarization operation described above. It is possible to control the coordinate dependency and further control the location coordinate dependency of the response voltage V of the pressure response means 9.

  The piezoelectric constant can be measured as the piezoelectric constant d33 using, for example, a commercially available d33 meter. The measurement can be performed after the polarization operation and before the external electrode 12 is formed.

About the pressure detection apparatus 8 comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.
First, a description will be given with reference to FIG. FIG. 3A shows the location coordinate dependence of the response voltage when a constant pressure is applied to the pressure response means from the outside. FIG. 3B shows the location coordinates of the pressure response means. It is a definition. The feature of the pressure response means of the present invention is that there are a plurality of pressure response means, and each response voltage is different for each location coordinate. The pressure response means shown in FIG. 3 is a simple and preferable example, and has two pressure response means, and the response voltages V (in this case, Va and Vb) corresponding to each pressure response means define the location. As the coordinate X increases, Va increases monotonously and Vb decreases monotonously. For this reason, the location coordinate dependency of each response voltage Va and Vb is different. For example, with respect to Va, the response voltage Va is Va1 at the location coordinate X1, the response voltage Va is Vm at the location coordinate Xm, and the response voltage Va also monotonously increases as the location coordinate X increases.

  The determination of the presence or absence of pressure application using this is made as follows. The pressure is applied when the response voltage V (Va, Vb in order corresponding to 9a, 9b) with respect to the applied pressure P0 is equal to or higher than the threshold voltage Vx (Vxa, Vxb in order corresponding to 9a, 9b). When it is less than Vx, it is determined that no pressure is applied. On the other hand, FIG. 4 is a diagram showing the relationship between the threshold voltage Vxa for 9a and the location coordinates, and it can be seen from this that the threshold voltage Vxa has coordinate coordinate dependency. Specifically, the threshold voltage Vxa is Vxa1 at the location coordinate X1, and the threshold voltage Vxa is Vxm at the location coordinate Xm. This is because the response voltage Va when a constant pressure is applied changes for each location coordinate X as shown in FIG. Although not specifically shown here, the threshold voltage Vxb monotonously decreases as the location coordinate X increases corresponding to Vb in FIG.

  Next, a method for obtaining the location coordinate X to which the pressure P0 is applied based on the response voltage V will be described. FIG. 5 shows the response voltage ratio Vb / Va (ratio of response voltages Vb and Va) at the location coordinate X. As can be seen from FIG. 5, the response voltage ratio Vb / Va monotonously decreases as the location coordinate X increases. Therefore, one location coordinate X corresponds to one response voltage ratio Vb / Va. That is, the location coordinate X can be specified from the response voltage ratio Vb / Va.

  The detection of the location coordinates is very effective because it can identify the intrusion location in addition to the presence or absence of intruders when installed and used on the outer periphery of a house such as a balcony or fence for security purposes. .

  In addition, when applied to an information input device, for example, a device that is installed on a steering wheel of an automobile and operates an electrical component in the vehicle, in addition to the pressure level, it is possible to input the location coordinates where pressure is applied with a simple structure. Therefore, the effect becomes large.

  In this way, by using the pressure response means 9 whose response voltage changes monotonously, it becomes easy to make the location coordinates uniquely correspond to the response voltage ratio, which means that the design becomes easy. To do. In addition, as described above, in the method for controlling the parameters during the polarization operation, the pressure response means in which the response voltage changes monotonously is manufactured with a response voltage that changes in a complicated manner for each location coordinate. This is also easier from the viewpoint of manufacturing cost.

On the other hand, since the pressure response means whose response voltage changes monotonously may be arranged adjacent to each other in the opposite direction, only one type of pressure response means may be manufactured, and the effect of reducing the manufacturing cost from this point is obtained. It is done.

  Here, the response voltage ratio Vb / Va is used when obtaining the location coordinate X to which the pressure P0 is applied based on the response voltage V. However, the present invention is not limited to this. .

  For example, αVa + βVb + γ (α, β, and γ are constants) can be used instead of the response voltage ratio Vb / Va as the relationship between the magnitudes of the plurality of response voltages of the pressure response means.

  Incidentally, the response voltage V of the pressure response means 9 generally has temperature dependency and humidity dependency. In particular, when bismuth / sodium titanate containing alkali metal, bismuth titanate / sodium-barium titanate, alkali niobate, or the like is used as the piezoelectric ceramic, the response voltage easily changes due to moisture absorption. In such a case, the method of obtaining the location coordinate X to which the pressure P0 is applied based on the response voltage ratio Vb / Va as described above is very effective.

  The reason is as follows. The response voltage V of the plurality of pressure sensitive response means 9 varies at the same rate depending on the humidity and temperature. For example, in a plurality of pressure sensitive response means, the same amount of water is absorbed by the increase in humidity, and the response voltage increases at substantially the same rate. For this reason, by taking the ratio of the response voltages, fluctuations due to moisture and temperature are offset, and the effect of more accurately determining the location coordinates X to which pressure is applied can be obtained.

  Further, the response voltage ratio can be obtained by simple calculation, and an effect of reducing the cost of the pressure determination unit by reducing the load of the pressure determination unit can be obtained.

  Although the case where the response voltages Va and Vb change monotonously with respect to the place slip X is considered here, if the response voltage ratio Vb / Va changes monotonously with respect to the place coordinate X, it is not always necessary. The response voltages Va and Vb do not need to change monotonously with respect to the location coordinate X.

  Finally, the procedure for determining the presence / absence of external pressure application and the determination of the location coordinates where the pressure is applied by the pressure detection apparatus will be described with reference to FIG.

  First, response voltages Va and Vb are generated in the pressure response means 9a and 9b by the external application of the pressure P0, and the pressure determination means 10 measures them (ST1). Next, the response voltage ratio Vb / Va is calculated by the pressure determination means 10 (ST2). Subsequently, the location coordinate X corresponding to the response voltage ratio Vb / Va is read from the memory included in the pressure determination means 10 (ST3). The relationship between the response voltage ratio and the location coordinate X can be experimentally measured in advance and recorded in a memory included in the pressure determination unit 10.

  On the other hand, the threshold voltage Vxa corresponding to the response voltage Va at the location coordinate X is read from the memory included in the pressure determination means 10 (ST4). The relationship between the location coordinate X and the threshold voltage Vxa corresponding to the response voltage Va at the location coordinate X can be experimentally measured in advance and recorded in the memory of the pressure determination means 10.

  Subsequently, the pressure determination means 10 compares Vxa read from the memory with the measured Va, and determines the magnitude (ST5).

If Va ≧ Vxa according to the above determination, the location coordinate X and the determination of the presence of pressure application are output (ST6). Although not shown in the drawing, preferred means such as a display and a speaker can be used as the output destination. If Va <Vxa, nothing is output (ST7).
.

  Therefore, only when the response voltage Va equal to or higher than the threshold voltage Vxa is generated by the application of the pressure P0 to the pressure response means 9, the location coordinates X of the pressure application and the determination of the presence of pressure application are output.

  In FIG. 6, Vxa corresponding to Va is used for determination of pressure application, but Vxb may be used instead, or both of them may be used. For example, it can be determined that pressure is applied when Vb ≧ Vxb and Va ≧ Vxa.

  In addition, the piezoelectric ceramic in the flexible pressure-sensitive body of the pressure detecting means of the present invention is preferably one that does not contain lead in consideration of the disposal process. For example, barium titanate, bismuth / sodium titanate, bismuth / sodium titanate-barium titanate, alkali niobate, etc. are preferably used. Furthermore, when used outdoors, such as for security purposes, or in environments using water such as toilets, baths, and kitchens, it is more preferable that the piezoelectric ceramic powder is subjected to a water repellent treatment to prevent moisture from entering. This is because the piezoelectric ceramic containing the above alkali metal easily absorbs moisture, and the performance easily fluctuates accordingly.

  Note that the materials and methods described in this embodiment can also be suitably applied to the following embodiments.

(Embodiment 2)
The feature of the present embodiment is that the pressure detection device 10 has three pressure response means.

  FIG. 7A shows the location coordinate dependence of the response voltages Va, Vb, Vc corresponding to the pressure response means 9a, 9b, 9c of the pressure detection device 10 in the present embodiment. FIG. 7B is an overview of the pressure detection device 10 according to the present embodiment as viewed from above, and shows the definition of location coordinates. Although the sectional view of the pressure response means 9, 9b, 9c is not shown, it has the cable-like structure shown in FIG. 2 of the first embodiment.

  From FIG. 7A, Va takes a constant value V0. Vb is V0 at the location coordinate 0, but monotonously decreases and becomes 0 at X0 (= 5Xu). Further, Vc repeats monotonous decrease from V0 to 0 for each unit of Xu of the location coordinate X.

  Due to the location coordinate dependency of the response voltage shown in FIG. 7A, the response voltage ratios Vb / Va and Vc / Va show the location coordinate dependency shown in FIG. By using such a plurality of response voltage ratios, the location coordinate X to which the pressure P0 is applied can be determined more accurately.

Specifically, when Vb / Va in FIG. 8 is Vb1 / Va1, it is possible to determine X1, which is the corresponding location coordinate X. However, Vc1 / Va1 is always measured with a certain accuracy. If the accuracy is assumed to be 5%, the accuracy of the determined X1 is also considered to be about 5% with respect to X0 (= 5Xu). Therefore, it is further considered to determine the location coordinate X using Vc1 / Va1. In the case of Vc / Va = Vc1 / Va1, as shown in FIG. 8, the corresponding location coordinates X are 5 in one place in each section of 0 to Xu, Xu to 2Xu, 2Xu to 3Xu, 3Xu to 4Xu, 4Xu to 5Xu. Exists. However, from Vb / Va = Vb1 / Va1, since it is known that the location coordinate X is in 3Xu to 4Xu, it can be determined to one of the five. Here, if the measurement accuracy of Vc / Va is 5%, which is about the same as the measurement accuracy of Vb / Va, the location coordinates in the 3Xu to 4Xu interval from the value of Vc / Va is 5% accuracy relative to Xu. It can be decided by. Therefore, it can be seen that X can be determined with five times higher accuracy than the case where the location coordinate X is determined only from Vb / Va.

  Finally, the procedure for determining the presence / absence of external pressure application and the determination of the location coordinates where the pressure is applied by the pressure detection apparatus will be described with reference to FIG.

  First, response voltages Va, Vb, and Vc are generated in the pressure response means 9a, 9b, and 9c by the external application of the pressure P0, and the pressure determination means 10 measures them (ST1). Next, the response voltage ratios Vb / Va and Vc / Va are calculated by the pressure determination means 10 (ST2). Subsequently, the location coordinate Xba corresponding to the response voltage ratio Vb / Va is read from the memory of the pressure determination means 10 (ST3). Further, the location coordinates Xca1, Xca2, Xca3, Xca4, Xca5 corresponding to the response voltage ratio Vc / Va are read from the memory included in the pressure determination means 10 (ST4). Here, the five location coordinates are read because Vc monotonously decreases periodically five times as described above.

  Next, among the location coordinates Xca1, Xca2, Xca3, Xca4, and Xca5, the one closest to Xba is set as the position coordinate X to be obtained (ST5). In this manner, the position coordinate table X with higher accuracy than Xba can be determined as the location coordinates to which the external pressure P0 is applied.

  Thereafter, in the same manner as in the first embodiment, the threshold voltage output Vxa corresponding to the response voltage Va at the pressure application location coordinate X is read from the memory included in the pressure determination means 10 (ST6) and read from the memory. The pressure determination means 10 compares Vxa with the measured Va, and determines the magnitude (ST7). Then, if Va ≧ Vxa, the position coordinate X and the determination of presence of pressure are output (ST8). If Va <Vxa, no output is performed (ST9).

  The relationship between the location coordinate X and the response voltage V and the relationship between the location coordinate X and the threshold voltage Vx can be experimentally measured in advance and recorded in the memory of the pressure determination means 10.

  In this embodiment, the case where there are three pressure determination means is considered, and the case where the cycle of the response voltage of the third pressure determination means is 1/5 of the length of the pressure response means. By increasing the number of pressure determination means or by shortening the cycle of the response voltage of the pressure response means, it is possible to further improve the accuracy of location coordinate detection.

(Embodiment 3)
The feature of this embodiment is that the response voltage realizes location dependence with respect to the application of a constant pressure from the outside, because the thickness of the protective layer of the pressure response means varies from location to location.

  FIG. 10 shows the definition of location coordinates for the two pressure response means 9a, 9b of the pressure detection device 8 in the present embodiment. In FIG. 9, the pressure response means 9a and 9b are divided into n + 1 portions for each location coordinate.

FIG. 11 (a) shows a longitudinal section of the pressure response means 9a. In the pressure response means 9a, the thickness of the protective layer 13 increases from the left end portion toward the right end portion. Further, it can be seen that the thicknesses of the pressure transmitting portion 6 and the support fixing portion 7 are adjusted so that the pressure P0 from the outside is equally applied to the pressure response means 9a and 9b. However, for the sake of simplicity, in particular, both ends and the m-th part are cut out and the other parts are omitted. The cross section of the pressure response means 9b is not shown because it is shaded by 9a. However, with respect to 9b, there is no change in the thickness of the protective layer 13 due to the location coordinates, and the pressure transmission section 6 shown in FIG. And the thickness of the pressure response means 9b portion of the support fixing portion 7 is n + 1th from the first (right end) portion (
The leftmost part is constant in all parts.

  FIG. 11B described above shows a cross section at the DD line position in the first (right end) portion of the pressure response means 9a, 9b. Both have the structure of a coaxial cable, and have a configuration in which the upper part is sandwiched between the pressure transmission part 6 and the lower part is sandwiched between the support fixing parts 7.

  Thus, the pressure response means 9a has different thicknesses of the protective layer 13 for each portion, so that a different response voltage Va is generated for each portion in response to a constant external pressure application. This is shown in FIG. In the pressure response means 9a, the response voltage Va decreases step by step for each portion corresponding to the thickness of the protective layer 13 increasing from the left end portion to the right end portion shown in FIG. Recognize. This is because as the protective layer 13 becomes thicker, the proportion of the external pressure P0 that is transmitted to the flexible pressure sensitive body 11 decreases. On the other hand, since the thickness of the protective layer 13 is constant, the pressure response means 9b has the same response voltage V0 in all parts.

  The response voltage ratio Va / Vb also has a different value for each portion because of the dependence of the response voltage on the position coordinates of each pressure response means 9a, 9b described in FIG. Although not specifically shown here, since the response voltage Vb is constant, the response voltage ratio Va / Vb is a discontinuous value exactly as Va in FIG. In the meantime, it decreases in steps from the left to the right.

  Thus, since the response voltage ratio Va / Vb is different for each portion, the portion to which the pressure P0 is applied can be specified from the response voltage ratio Va / Vb according to the procedure described in the first embodiment.

  As shown in the present embodiment, the response voltage ratio Va / Vb can be adjusted by changing the thickness of the protective layer 13. This means that the response voltage V at each location (part) can be adjusted by the difference in the protective layer 13 even when the flexible pressure-sensitive body 11 has already been formed and polarization has ended. To do. In other words, this means that it is easy to cope with changes in specifications, and the effect of increasing the design margin is obtained.

  Further, by using the flexible pressure-sensitive body 11 having different remanent polarization for each location coordinate, and further adding a change in the thickness of the protective layer 13, the change in the response voltage ratio can be further increased. As a result, it is possible to obtain an effect that enables more accurate location detection.

  Further, since the response voltage ratio Va / Vb has a discontinuous value, the response voltage ratio Va / Vb does not necessarily need to be monotonously increased or decreased. When the response voltage ratio changes continuously, if the response voltage ratio Va / Vb increases and then decreases, there are two location coordinates having the same response voltage ratio, so that these location coordinates cannot be distinguished. However, in the case of taking a discontinuous value for each part as in the case of the present embodiment, even if it decreases after the increase, if the value is slightly different, it becomes possible to distinguish each part. Because. For this reason, the degree of freedom is widened in the design of the pressure response means, and the effect of facilitating the production can be obtained.

  On the other hand, due to the discontinuous response voltage ratio Va / Vb of the present invention, the difference in the response voltage ratio Va / Vb becomes larger at the boundary between the portions. For this reason, the effect which can judge more correctly which part pressure P0 was applied is acquired. Further, even when there is variation in the residual polarization and thickness of the flexible pressure-sensitive body 11, an effect of accurately detecting the portion to which the pressure P0 is applied can be obtained.

11 shows an example in which the thickness of the protective layer 13 is constant in each part of the pressure response means 9a, but it is also possible to change the thickness continuously in each part. In this case, since the response voltage ratio is not constant and has a different value in each part, it is possible to detect a location coordinate that can be represented by a point instead of a part having a width.

  In the present embodiment, the response voltage is adjusted by changing the thickness for each location coordinate of the protective layer 13, but the same effect can be obtained by changing the elastic modulus of the protection layer 13 for each location coordinate. It is done.

(Embodiment 4)
A feature of the present embodiment is that a single pressure response means 9a has a plurality of flexible pressure sensitive bodies 11, internal electrodes 14 and external electrodes 12 corresponding to them.

  FIG. 13 is an overview of the pressure detection device 8 according to the present embodiment as viewed from above. It can be seen that there is only one pressure response means 9a.

  FIG. 14A shows a cross section in the longitudinal direction of the pressure response means 9 a that exists only one in the pressure detection device 8. Further, among the flexible pressure-sensitive body 11, the external electrode 12, and the internal electrode 14 that exist in two sets in the pressure response means 9a, one set at the back is not shown because it overlaps with the previous one. .

  On the other hand, FIG. 14B shows a cross section taken along the line DD in FIG. The two sets of the flexible pressure sensitive body 11, the internal electrode 14, and the external electrode 12 all have a coaxial cable structure. Two sets are wrapped in one protective layer 13, and the upper part is a pressure transmitting portion. 6. The lower part is sandwiched between the support fixing parts 7.

  A plurality of flexible pressure sensitive bodies 11, internal electrodes 14, and external electrodes 12 are wrapped in one protective layer 13 to form one pressure response means 9a, and the number of pressure response means is small. 6 and the support fixing part 7, the effect that arrangement | positioning to an apparatus or an installation becomes easy is acquired. Moreover, since the protective layer 13 becomes one, the process is simplified, and the effect of reducing the manufacturing cost can be obtained.

  In FIG. 13, the external electrode 12 and the flexible pressure sensitive body 11 are provided separately, but it is also possible to provide two internal electrodes 11 in common. In this case, the manufacturing process is further simplified and the manufacturing cost can be reduced.

  Note that the determination of whether or not the pressure P0 is applied and the detection of the location coordinates to which the pressure P0 is applied can be performed in the same manner as the procedure described in the first embodiment.

(Embodiment 5)
The feature of the present embodiment is that, with respect to the pressure transmission unit 6 having an action of transmitting the pressure P0 from the outside to the plurality of pressure response units 9, the elastic modulus of the portion in contact with the pressure response unit 9 varies for each location coordinate. Is a point.

  Hereinafter, the outline of the configuration and operation of the present embodiment will be described with reference to FIGS. 15 to 19, but is not limited thereto.

  FIG. 15A is a cross-sectional view including a longitudinal section of 9a among the two pressure response means 9a and 9b existing in the pressure detecting device 8. FIG. In FIG. 15A, for the sake of simplicity, only one cross section of the two pressure response means 9a and 9b is shown, but the other cross section has a similar structure.

  FIG. 15B shows a cross section taken along the line F-F in FIG.

  Further, at this time, it is assumed that the general view of the pressure detection device 8 of the present embodiment viewed from the upper part parallel to the longitudinal direction of the pressure response means is the same as FIG. 1 of the embodiment.

  As can be seen from FIG. 15 (b), the pressure transmission part 6 at the upper part of the two pressure response means is composed of the pressure transmission part main part 6c and the pressure transmission part contact parts 6a and 6b formed at the lower part. Is formed. It is important that the elastic moduli of the pressure transmission contact portions 6a and 6b have different location coordinate dependencies. Here, the location coordinates of the present embodiment are defined in the same manner as that shown in FIG. 10 of the third embodiment.

  Next, the outline of the operation will be described with reference to FIG. FIG. 16 (a) is the same as FIG. 15 (a), and the change from FIG. 16 (a) to FIG. 16 (b) shows the change when the external pressure P0 is applied. Is. In FIG. 16 (b), the pressure transmission units 6a and 6b are greatly compressed by the pressure P0 from the outside, and the pressures Fa and Fb are respectively applied to the pressure response means 9a and 9b via the pressure transmission units 6a and 6b. It can be seen that the pressure response means 9a and 9b are distorted in the vertical direction.

  By the way, as described in the lower part of FIG. 16B, the elastic moduli of the pressure transmission part contact parts 6a and 6b are Ga and Gb in this order, and the magnitude relationship is Gb> Ga. Here, considering that the strain γ of the pressure transmission unit contact portions 6a and 6b is the same, the forces applied to the pressure response means 9a and 9b are Fa = Ga × γ and Fb = Gb × γ in this order, When attention is paid to Gb> Ga, it can be seen that Fa <Fb. Accordingly, the response voltages corresponding to the pressure response means 9a and 9b are different and Vb> Va.

  Furthermore, the force applied to the pressure transmission part contact portions 6a and 6b and the pressure response means 9a and 9b for each location coordinate and the response voltage generated by this force will be described with reference to FIGS.

  First, with reference to FIG. 17, the dependence of the elastic modulus of the pressure transmission portion contact portions 6a and 6b on each location coordinate will be described.

  FIG. 17 shows that Gb is constant regardless of the location coordinates, Ga is different in each location coordinate section, and the value decreases monotonically as the location coordinates increase from 0 to X0.

  FIG. 18 shows the location dependency of the forces Fa and Fb applied to the pressure response means 9a and 9b corresponding to the elastic modulus.

  FIG. 18 shows that Fb is constant regardless of the location coordinates, Fa is different in each location coordinate section, and the value decreases monotonously as the location coordinates increase from 0 to X0. This is because the corresponding elastic modulus changes similarly as shown in FIG.

  FIG. 19 shows the location dependence of the response voltage ratio Va / Vb generated in the pressure response means 9a, 9b corresponding to the above force.

  From FIG. 19, it can be seen that Va / Vb is different in each location coordinate section, and the value decreases monotonously as the location coordinate increases from 0 to X0. This is because the generated voltages Va and Vb proportional to the corresponding forces Fa and Fb are generated as shown in FIG. Using the location coordinate dependency of Va / Vb, location coordinates can be detected in the same manner as the procedure described in the first embodiment.

  As described above, the location detection can be performed without changing the piezoelectric constant, the thickness of the protective layer, and the elastic modulus of the flexible pressure-sensitive body in the pressure response means 9 only by changing the elastic modulus of the support fixing portion contact portions 6a and 6b. Is possible. As a result, it is possible to obtain an effect that the manufacture of the pressure response means becomes much easier. In particular, the pressure response means of the present embodiment is preferably of the same type. Here, the same type means that the dimensions, the above-described piezoelectric constant, and the constitution represented by the thickness elastic modulus of the protective layer are the same. Thus, by using the same type of pressure response means manufactured by the same manufacturing process, the supply of the stress response means becomes much easier. Further, even if the same type of pressure response means is used, a desired generated voltage can be obtained simply by adjusting the elastic modulus of the supporting and fixing portion contact portions 6a and 6b, so that the effect of facilitating the design according to the application is also obtained. It is done.

  In addition, regarding the support fixing portion contact portions 6a and 6b of the present embodiment, any material may be used as long as the elastic modulus can be adjusted. For example, the elastic modulus can be adjusted by foaming a resin such as rubber. It is also possible to adjust the elastic modulus by using a spring-like member for the rubber support fixing portion contact portion.

  Further, since the support fixing main part 6c is preferably bent to some extent in the longitudinal direction of the pressure response means, a flexible resin sheet, tape, cloth, nonwoven fabric, or the like is used.

(Embodiment 6)
The feature of this embodiment is that the pressure transmission part that transmits the pressure P0 from the outside to the pressure response means is integrated with the pressure transmission part support part having a fixed direction.

  20 and 21, the configuration of the present embodiment and the outline of the operation of the pressure detection apparatus having two pressure response means will be described, but the present invention is not limited to this.

  Further, here, as the location coordinates, those defined in the same manner as those shown in FIG. 10 of the third embodiment are used.

  Moreover, the general view of the pressure detection device 8 of the present embodiment as viewed from the top parallel to the longitudinal direction of the pressure response means 9 is the same as FIG. 1 of the embodiment.

  FIG. 20 is a cross-sectional view taken along a plane perpendicular to the longitudinal direction of the pressure response means 9 of the pressure detection device 8 of the present embodiment.

  From FIG. 20, the pressure transmission part 6 is the same as FIG. 15 of Embodiment 5 in that the pressure transmission part main part 6c and the pressure transmission part contact parts 6a and 6b are formed in the lower part. I understand that. The difference is that the pressure transmission part main part 6c is formed by being coupled to the pressure transmission part support part 6d, and this pressure transmission part support part 6d is inserted into the hollow pressure transmission part support fixing part 6e, The lower pressure transmission portion support fixing portion 6e is fixed to the support fixing portion main portion 7a.

  The direction of the pressure transmission part support fixing part lower 6e is fixed because the pressure transmission part support fixing part lower 6e is fixed to the support fixing part main part 7a. Further, the direction of the pressure transmission unit support portion 6d is fixed by inserting the pressure transmission unit support portion 6d into the pressure transmission unit support fixing portion 6e. In this way, the direction of the pressure transmission part main part 6c formed by coupling to the pressure transmission part support part 6d is fixed, and finally the horizontality of the pressure transmission parts 6a and 6b is fixed.

  As a result, the variation in force applied to the pressure response means 9a and 9b is further reduced, and as a result, an effect of enabling highly accurate location detection is obtained.

  Here, it is preferable to reduce friction by using a bearing or a lubricant at a portion where the upper pressure transmission portion support fixing portion 6d is inserted into the lower pressure transmission portion support portion 6e.

  In addition, here, the pressure transmitting portion supporting and fixing portion lower 6e is fixed to the supporting and fixing portion main portion 7a. However, as long as the pressure transmitting portion supporting and fixing portion main portion 7a is fixed, the place to be fixed need not be the supporting and fixing portion main portion 7a. .

  Further, as shown in FIG. 20, the difference from the fifth embodiment is that the support fixing portion partition wall 7b is formed continuously with the support fixing portion main portion 7a.

  By forming the support fixing portion partition wall 7b, the pressure response means 9a and 9b are separated and fixed, the positional deviation of the pressure response means is suppressed, and the force between the pressure response means 9a and 9b is reduced. By suppressing the transmission, the variation in the pressure response means response voltages Va and Vb is reduced, and the effect of suppressing the variation in the location detection can be obtained.

  Further, it can be seen that the compression width of the pressure response means 9a, 9b becomes the maximum h2 due to the presence of the figure support fixing part partition wall 7b. As a result, even when an excessive pressure P0 is applied from the outside, it is possible to suppress excessive deformation of the pressure response means and to minimize deterioration such as plastic deformation occurring in the pressure response means 9.

  This effect also occurs in the gap h1 formed by inserting the upper pressure transmission part support 6d into the lower pressure transmission part support 6e. That is, even when an excessive pressure P0 is applied from the outside, the compression width of the pressure response means is suppressed to h1 or less, and deterioration such as plastic deformation occurring in the pressure response means is suppressed to a minimum.

  Next, the configuration and operation of the pressure transmission unit 6 in the longitudinal direction of the pressure response means 9 in the present embodiment will be described with reference to FIG.

  Further, from FIG. 21, the point different from the fifth embodiment is that the pressure response transmission unit 6 is discontinuous at the boundary of each position coordinate section. In FIG. 21, for the sake of simplicity, only the cross section corresponding to 9a of the two pressure response means 9a and 9b is shown, but the pressure response means 9a and 9b are equivalent as shown in FIG. The cross section corresponding to the pressure hammering means 9b has a similar structure.

  Thus, the pressure transmission means 6 is formed separately for each position coordinate section, and a gap is formed between them, so that it is possible to apply force independently to each section. It becomes. As a result, when P0 is applied to a certain coordinate section, the force applied to the pressure response means in the other coordinate section via the pressure transmission unit 6 decreases. For this reason, the response voltages Va and Vb in each coordinate section are obtained independently and accurately, and the effect of increasing the accuracy of location detection is obtained.

  Note that the determination of whether or not the pressure P0 is applied and the detection of the location coordinates to which the pressure P0 is applied can be performed in the same manner as the procedure described in the first embodiment.

  In addition, the structure of the pressure transmission part support part of this Embodiment and a support fixing | fixed part partition is applicable also to other embodiment of this invention.

As described above, the pressure detection device of the present invention makes a determination regarding the location of pressure application in addition to the determination of whether or not pressure is applied, and therefore, particularly for security applications, such as the outer periphery of a house such as a balcony or a fence. It is preferably used by being installed in a long part. Moreover, since the pressure application location can be used as input information in addition to the pressure level, it can be suitably used for an information input device, for example, a device that is installed on a steering wheel of a car and operates electrical components in the car.

(A) The schematic diagram showing the structure of the pressure detection apparatus of Embodiment 1 of this invention (b) Sectional drawing of the same pressure detection apparatus BB line position (A) Cross-sectional view of the pressure detection device according to the first embodiment of the present invention (b) Cross-sectional view of the pressure detection device CC line position (A) Graph showing the dependence of the response voltage on the location coordinates in the pressure response means according to the first embodiment of the present invention (b) An explanatory diagram defining the location coordinates of the pressure response means The graph which showed the place coordinate dependence of the threshold voltage with respect to the pressure response means in Embodiment 1 of this invention The graph which showed the place coordinate dependence of the response voltage ratio of the pressure response means in Embodiment 1 of this invention The flowchart which showed the procedure of the judgment of the place coordinate to which the pressure was applied in Embodiment 1 of this invention, and the pressure application presence / absence (A) A graph showing the dependency of the response voltage of the pressure response means in the second embodiment of the present invention on the location coordinates (b) An explanatory diagram defining the location coordinates of the pressure response means The graph which showed the place coordinate dependence of the response voltage ratio of the pressure response means in Embodiment 2 of this invention The flowchart which showed the procedure of the judgment of the place coordinate to which the pressure was applied in Embodiment 2 of this invention, and the pressure application presence / absence Explanatory drawing which defined the place coordinate of the pressure response means in Embodiment 3 of this invention (A) Cross-sectional view of the pressure detection device of Embodiment 3 of the present invention (b) Cross-sectional view of the pressure detection device DD line position The graph showing the location coordinate dependence of the response voltage in the pressure response means of Embodiment 3 of this invention The schematic diagram showing the structure of the pressure detection apparatus of Embodiment 4 of this invention (A) Cross-sectional view of the pressure detection device according to the fourth embodiment of the present invention (b) Cross-sectional view of the pressure detection device EE line position (A) Cross-sectional view of the pressure detection device of Embodiment 5 of the present invention (b) Cross-sectional view of the pressure detection device FF line position (A) Cross-sectional view of the pressure response means of the pressure detection device according to the fifth embodiment of the present invention in a plane perpendicular to the longitudinal direction (b) When pressure is applied to the pressure detection device and the pressure response means is greatly distorted The same sectional view The graph which showed the place coordinate dependence of the elasticity modulus of the support fixing | fixed part contact part in Embodiment 5 of this invention The graph which showed the place coordinate dependence of the force added to the pressure response means in Embodiment 5 of this invention The graph which showed the place coordinate dependence of the response voltage ratio of the pressure response means in Embodiment 5 of this invention Sectional drawing in the surface perpendicular | vertical to the longitudinal direction of the pressure response means of the pressure detection apparatus of Embodiment 6 of this invention Sectional drawing in the surface parallel to the longitudinal direction of the pressure response means of the pressure detection apparatus of Embodiment 6 of this invention Sectional view of a conventional sheet-like pressure response means (A) Cross-sectional view of a conventional cable-like pressure response means (b) Cross-sectional view of the AA line position

Explanation of symbols

6 pressure transmission part 6a pressure transmission part contact part 6b pressure transmission part contact part 6c pressure transmission part main part 6d pressure transmission part support part 6e pressure transmission part support part 7 support fixing part 7a support fixing part main part 7b support fixing part partition DESCRIPTION OF SYMBOLS 8 Pressure detection apparatus 9a Pressure response means 9b Pressure response means 9c Pressure response means 10 Pressure determination means 11 Flexible pressure sensitive body 12 External electrode 13 Protective layer 14 Internal electrode

Claims (13)

Linear pressure response means including a flexible pressure sensitive body and an electrode for measuring a potential difference generated in the flexible pressure sensitive body as a response voltage when pressure is applied from the outside;
Pressure determining means for determining the presence or absence of external pressure application to the pressure response means,
A plurality of the pressure response means are disposed adjacent to each other;
The response voltages of the plurality of pressure response means have different location coordinate dependencies when a constant pressure is applied from the outside,
The pressure detection device in which the pressure determination unit determines a location coordinate to which the pressure from the outside is applied based on a relationship between the magnitudes of a plurality of response voltages of the pressure response unit. The pressure response means includes a plurality of flexible pressure sensitive bodies and a plurality of electrodes for measuring a response voltage generated in the flexible pressure sensitive bodies.
2. The pressure according to claim 1, wherein the pressure response means generates response voltages having different location coordinate dependencies corresponding to the plurality of flexible pressure sensitive bodies when a constant pressure is applied from the outside. Detection device. The pressure detection according to claim 1 or 2, wherein a response voltage generated when a constant pressure is applied to the pressure response means from outside changes monotonously from one end of the pressure response means to the other end. apparatus. The piezoelectric constants of the plurality of flexible pressure-sensitive bodies constituting the pressure response means have different location coordinate dependencies, so that the plurality of response voltages of the pressure response means have different location coordinate dependencies. The pressure detection apparatus of any one of 1-3. The protective layer is formed to protect the pressure response means, and the thickness of the protective layer has location coordinate dependence, so that the plurality of response voltages of the pressure response means have different location coordinate dependence. The pressure detection apparatus of any one of -4. The pressure determination means calculates the response voltage ratio from a plurality of different response voltages having different location coordinate dependencies when determining the location coordinates to which pressure is applied from the outside, and makes the determination. The pressure detection device according to any one of 5. The pressure detection device according to any one of claims 1 to 6, wherein the linear pressure response means is a cable-like pressure response means, and the plurality of cable-like pressure response means are disposed adjacent to each other. The cable-like pressure response means includes an internal electrode located at a substantially central portion of the cable-like pressure response means, a flexible pressure sensitive body in close contact with the internal electrode, and an external electrode in close contact with the flexible pressure sensitive body. The pressure detection device according to claim 7, wherein the internal electrode and the external electrode are used for response voltage measurement. It has a pressure transmission part that transmits pressure from the outside to a plurality of pressure response means,
The pressure detection device according to any one of claims 1 to 8, wherein an elastic modulus of a portion of the pressure transmission unit that is in contact with each pressure response unit has a location coordinate dependency that is different for each pressure response unit. The pressure detection device according to any one of claims 1 to 9, wherein the plurality of pressure response means are pressure response means of the same type. The pressure detection device according to any one of claims 1 to 10, wherein a plurality of pressure transmission units are provided at different location coordinates apart from each other on the pressure response means. The pressure detection device according to any one of claims 1 to 11, further comprising a pressure transmission unit support unit that is integral with the pressure transmission unit and has a fixed direction in order to maintain the level of the pressure transmission unit. The pressure detection device according to any one of claims 1 to 12, wherein a support fixing portion that fixes the pressure response means includes a support fixing portion partition wall that fixes the plurality of pressure response means without contact.

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