Input device and control method for input device

Abstract

To provide an input device whose operation unit includes a plurality of piezoelectric elements, and which appropriately determines a piezoelectric element corresponding to an operated portion on an operation surface.SOLUTION: An input device ID includes an operation unit OU and a control unit CU. The operation unit OU includes an operation surface operated by an operation element and a plurality of piezoelectric elements 14 arranged on a rear side of the operation surface, and outputs, in each of the plurality of piezoelectric elements 14, a signal corresponding to a charge generated in the piezoelectric elements 14. The control unit CU determines, amongst the plurality of piezoelectric elements 14, the piezoelectric element 14 corresponding to an operated portion on the operation surface, on the basis of the signal output from the operation unit OU. The control unit CU determines the piezoelectric element 14 corresponding to the operated portion on the operation surface, on the basis of information regarding a timing at which a value based on the signal transitions from a state greater than a falling threshold to a state equal to or less than the falling threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an input device or a method for controlling an input device. [Background technology]

[0002] A known input device includes an operation unit including an operation surface operated by an operation object and a piezoelectric element disposed on the back side of the operation surface. When the operation object operates the operation surface, the piezoelectric element is displaced in response to an external force applied to the operation surface. When the piezoelectric element is displaced, an electric charge is generated in the piezoelectric element. The operation unit outputs a signal in response to the electric charge generated in the piezoelectric element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-059607 Summary of the Invention [Problem to be solved by the invention]

[0004] When the operation unit includes a plurality of piezoelectric elements, the following problems may occur. For example, when an operating object operates an operating surface, an external force may be applied not only to the piezoelectric element corresponding to the operated portion on the operating surface, but also to piezoelectric elements other than the operated portion. The piezoelectric element corresponding to the operated portion on the operating surface is sometimes referred to as a "corresponding piezoelectric element," and piezoelectric elements other than the piezoelectric element corresponding to the operated portion on the operating surface are sometimes referred to as "non-corresponding piezoelectric elements." When an external force is transmitted to the non-corresponding piezoelectric element, the non-corresponding piezoelectric element is displaced, and an electric charge is generated in the non-corresponding piezoelectric element. The operation unit outputs not only a signal corresponding to the electric charge generated in the corresponding piezoelectric element, but also a signal corresponding to the electric charge generated in the non-corresponding piezoelectric element. When a signal corresponding to the electric charge generated in the non-corresponding piezoelectric element is output from the operation unit, it is difficult for the input device to appropriately determine which of the multiple piezoelectric elements is the corresponding piezoelectric element.

[0005] One aspect of the present invention aims to provide an input device that appropriately determines the piezoelectric element corresponding to the operated portion on the operation surface, even if the operation unit includes a plurality of piezoelectric elements. Another aspect of the present invention aims to provide a control method for an input device having an operation unit including multiple piezoelectric elements, which control method appropriately determines the piezoelectric element corresponding to the operated portion on the operation surface. [Means for solving the problem]

[0006] An input device according to one aspect includes an operation unit and a control unit. The operation unit includes an operation surface operated by an operation object and a plurality of piezoelectric elements arranged on the back side of the operation surface, and outputs a signal corresponding to an electric charge generated in each of the plurality of piezoelectric elements. The control unit determines, based on the signal output from the operation unit, a piezoelectric element among the plurality of piezoelectric elements that corresponds to an operated portion of the operation surface. The control unit determines the piezoelectric element that corresponds to the operated portion of the operation surface based on information regarding the timing at which a value based on the signal transitions from a state greater than a falling threshold to a state equal to or less than the falling threshold.

[0007] As a result of research and study by the present inventors, the following facts have been discovered.

[0008] First, the inventors focused on a configuration in which a corresponding piezoelectric element is determined based on information about the timing at which a signal-based value transitions from a state smaller than a threshold value to a state equal to or greater than the threshold value. When an external force is applied not only to the corresponding piezoelectric element but also to the non-corresponding piezoelectric elements, as described above, the operation unit outputs a signal corresponding to the charge generated in the corresponding piezoelectric element and a signal corresponding to the charge generated in the non-corresponding piezoelectric element. An operation unit including a piezoelectric element has high responsiveness from the time an external force is applied to the piezoelectric element until the operation unit outputs a signal corresponding to the charge generated in the piezoelectric element. Therefore, when comparing the timing at which the signal-based value transitions from a state below the threshold to a state above the threshold for the corresponding piezoelectric element and the non-corresponding piezoelectric element, the interval between these timings is short. It is difficult to distinguish between the timing based on the signal corresponding to the charge generated in the corresponding piezoelectric element and the timing based on the signal corresponding to the charge generated in the non-corresponding piezoelectric element. Therefore, in a configuration in which the corresponding piezoelectric element is determined based on information regarding the timing at which the signal-based value transitions from a state in which it is smaller than the threshold to a state in which it is equal to or greater than the threshold, the corresponding piezoelectric element may not be determined appropriately.

[0009] Next, the inventors have focused on a configuration in which the corresponding piezoelectric element is determined based on information about the timing at which the signal-based value transitions from a state greater than the threshold to a state equal to or less than the threshold. When comparing the values ​​based on the signal corresponding to the charge generated in the piezoelectric body between the corresponding piezoelectric body and the non-corresponding piezoelectric body, the value based on the signal corresponding to the charge generated in the corresponding piezoelectric body is greater than the value based on the signal corresponding to the charge generated in the non-corresponding piezoelectric body. Due to the difference between these values, when comparing the timing at which the value based on the signal changes from a state above the threshold to a state below the threshold between the corresponding piezoelectric body and the non-corresponding piezoelectric body, the interval between these timings is large. Therefore, in a configuration in which the corresponding piezoelectric element is determined based on information regarding the timing at which the signal-based value transitions from a state greater than the threshold to a state equal to or less than the threshold, the corresponding piezoelectric element can be appropriately determined.

[0010] In the above-mentioned one aspect, the control unit determines the piezoelectric element corresponding to the operated portion on the operation surface based on information regarding the timing at which a value based on a signal corresponding to the charge generated in the piezoelectric element transitions from a state where it is greater than the lower threshold to a state where it is equal to or less than the lower threshold. Therefore, in the above-mentioned one aspect, even if the operation unit is configured to include multiple piezoelectric elements, the control unit appropriately determines the piezoelectric element corresponding to the operated portion on the operation surface.

[0011] The control unit may set a flag for each of the plurality of piezoelectric elements based on the timing at which the value based on the signal becomes equal to or greater than an upward threshold, and may clear the flag based on the timing at which the value becomes equal to or greater than a downward threshold, and may acquire the state of the flag as information, or may determine that the piezoelectric element whose flag is cleared latest is the piezoelectric element corresponding to the operated portion on the operating surface. As described above, the control unit is configured to determine the piezoelectric element whose flag is released latest as the piezoelectric element corresponding to the operated portion on the operating surface, thereby appropriately and reliably determining the piezoelectric element corresponding to the operated portion on the operating surface.

[0012] The control unit may set the flag after a predetermined period of time has elapsed since the value based on the signal becomes equal to or greater than the rising threshold. In a configuration in which the control unit sets a flag at the timing when a value based on a signal becomes equal to or greater than the rising threshold, the following problems may occur. Even when an external force due to a disturbance is applied to multiple piezoelectric elements, electric charges are generated in the piezoelectric elements, and the operation unit outputs a signal corresponding to the electric charges generated in the piezoelectric elements. If a value based on the signal output from the operation unit is greater than the rising threshold, the control unit sets a flag. Therefore, even if an external force due to a disturbance is applied to multiple piezoelectric elements, the control unit determines the piezoelectric element corresponding to the operated portion on the operation surface. The disturbance may include, for example, an unintended momentary touch on the operation surface or mechanical vibration transmitted from outside. The control unit sets a flag after a predetermined period of time has elapsed since the signal-based value reaches or exceeds the rising threshold, which makes it difficult to set a flag when an external force due to a disturbance is transmitted to multiple piezoelectric elements, and therefore more appropriately determines the piezoelectric element corresponding to the operated portion on the operation surface.

[0013] The control unit may acquire, for each of the multiple piezoelectric elements, information on the period from when the signal-based value becomes equal to or greater than the rising threshold to when it becomes equal to or less than the falling threshold, and may determine the piezoelectric element with the longest period as the piezoelectric element corresponding to the operated portion on the operating surface. As described above, the control unit is configured to determine the piezoelectric element with the longest period from the time when the signal-based value becomes equal to or greater than the rising threshold to the time when it becomes equal to or less than the falling threshold as the piezoelectric element corresponding to the operated portion on the operating surface, thereby appropriately and reliably determining the piezoelectric element corresponding to the operated portion on the operating surface.

[0014] The operation unit may include a plurality of piezoelectric elements, each of which may include a corresponding one of the plurality of piezoelectric bodies. The operation unit may include a panel having a first main surface including an operation surface and a second main surface opposite to the first main surface, and the plurality of piezoelectric elements may be disposed on the second main surface.

[0015] The control unit may determine that the piezoelectric element that transitions to a state below the falling threshold latest is the piezoelectric element that corresponds to the operated portion on the operation surface. A configuration in which the control unit determines the piezoelectric element that has the latest timing to transition to a state below the descending threshold as the piezoelectric element corresponding to the operated portion on the operating surface appropriately and reliably determines the piezoelectric element corresponding to the operated portion on the operating surface.

[0016] A control method for an input device according to another aspect, wherein the input device is an operation unit including an operation surface operated by an operating body and a plurality of piezoelectric bodies arranged on the back surface of the operation surface, the operation unit outputting a signal based on an electric charge generated in each of the plurality of piezoelectric bodies, and the control method includes acquiring the signal output from the operation unit, acquiring information relating to the timing at which a value based on the acquired signal transitions from a state greater than a lower threshold to a state equal to or less than the lower threshold, and determining, based on the acquired information, a piezoelectric body among the plurality of piezoelectric bodies that corresponds to the operated portion of the operation surface.

[0017] In the above-mentioned another aspect, the piezoelectric element corresponding to the operated portion on the operation surface is determined based on information regarding the timing at which a value based on a signal corresponding to an electric charge generated in the piezoelectric element transitions from a state in which it is greater than the lower threshold to a state in which it is equal to or less than the lower threshold. Therefore, in the above-mentioned another aspect, even if the operation unit is configured to include multiple piezoelectric elements, the piezoelectric element corresponding to the operated portion on the operation surface is appropriately determined.

[0018] The acquiring of the information may include setting a flag for each of the plurality of piezoelectric bodies based on the timing at which a value based on the signal becomes equal to or greater than an increasing threshold, clearing the flag based on the timing at which the value becomes equal to or greater than a decreasing threshold, and acquiring the state of the flag as information. The determining of the piezoelectric bodies may include determining the piezoelectric body whose flag is cleared latest as the piezoelectric body corresponding to the operated portion on the operation surface. As described above, the process of determining the piezoelectric body includes determining the piezoelectric body whose flag is released latest as the piezoelectric body corresponding to the operated portion on the operating surface, thereby appropriately and reliably determining the piezoelectric body corresponding to the operated portion on the operating surface.

[0019] Setting the flag may include setting the flag after a predetermined period of time has elapsed since the value based on the signal becomes equal to or greater than the rising threshold. The process of setting the flag after a predetermined period of time has elapsed since the signal-based value reached or exceeded the rising threshold makes it difficult to set the flag when an external force due to a disturbance is transmitted to multiple piezoelectric elements, and therefore more appropriately determines the piezoelectric element corresponding to the operated portion on the operation surface.

[0020] The acquiring of the information may include acquiring, for each of the plurality of piezoelectric bodies, information on a period from when the signal-based value is equal to or greater than an increasing threshold to when the signal-based value is equal to or less than a decreasing threshold. The determining of the piezoelectric body may include determining the piezoelectric body with the longest period as the piezoelectric body corresponding to the operated portion on the operation surface. As described above, the process of determining the piezoelectric body includes determining the piezoelectric body with the longest period from the time when the signal-based value is above the rising threshold to the time when it is below the falling threshold as the piezoelectric body corresponding to the operated portion on the operating surface, which appropriately and reliably determines the piezoelectric body corresponding to the operated portion on the operating surface.

[0021] Determining the piezoelectric body may include determining the piezoelectric body that transitions to a state below the falling threshold latest as the piezoelectric body that corresponds to the operated portion on the operation surface. The process of determining the piezoelectric body includes determining the piezoelectric body that has the latest timing of transitioning to a state below the falling threshold as the piezoelectric body corresponding to the operated portion on the operation surface, thereby appropriately and reliably determining the piezoelectric body corresponding to the operated portion on the operation surface. [Effects of the Invention]

[0022] One aspect of the present invention provides an input device in which an operation unit includes a plurality of piezoelectric elements, and the input device appropriately determines the piezoelectric element corresponding to an operated portion on the operation surface. Another aspect of the present invention provides a control method for an input device in which an operation unit includes a plurality of piezoelectric elements, the control method appropriately determining the piezoelectric element corresponding to an operated portion on the operation surface. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a plan view of an input device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a cross-sectional configuration of the input device. [Figure 3] FIG. 3 is a block diagram of the input device. [Figure 4] FIG. 4 is a flowchart showing an example of a control process in the input device. [Figure 5] FIG. 5 is a diagram illustrating an example of a control process in the input device. [Figure 6] FIG. 6 is a flowchart showing another example of the control process in the input device. [Figure 7] FIG. 7 is a diagram illustrating another example of the control process in the input device. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be denoted by the same reference numerals, and redundant description will be omitted.

[0025] The configuration of an input device ID according to this embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a plan view of an input device according to this embodiment. Fig. 2 is a diagram showing a cross-sectional configuration of the input device. Fig. 3 is a block diagram of the input device. As shown in FIGS. 1 to 3, the input device ID includes an operation unit OU and a control unit CU. The input device ID is included in, for example, an electric device (not shown). The input device ID is used, for example, to control the operation of the electric device. The operation unit OU includes an operation panel 1 and a plurality of piezoelectric sensors 10.

[0026] The operation panel 1 includes a pair of principal surfaces 1a and 1b facing each other. The principal surface 1a is operated by an operating object. That is, the principal surface 1a includes an operating surface. The operating object includes, for example, a part of a living body, an object covering a part of a living body, or an object held by a living body. The part of a living body includes, for example, a fingertip of a human body. The object covering a part of a living body includes, for example, a glove worn on a human hand. The object held by a living body includes, for example, an operating member. The operation panel 1 may be made of metal or resin. For example, the operation panel 1 may be made of stainless steel. The operation panel 1 may include, for example, a housing included in an electrical device. The operation panel 1 may be a plate-shaped member. The thickness of the operation panel 1 is, for example, 0.8 mm.

[0027] The main surface 1a includes a plurality of operation areas 3 that are operated by an operating body. The operating body can come into contact with each of the plurality of operation areas 3. Each of the plurality of operation areas 3 includes a portion of the operation surface that can be operated by the operating body. When the operating body comes into contact with an operation area 3, a force is applied to the operation area 3 from the operating body. The plurality of operation areas 3 are positioned at a predetermined pitch along a predetermined direction. The plurality of operation areas 3 may be positioned in a line in a one-dimensional direction. The plurality of operation areas 3 may be positioned in a matrix in a two-dimensional direction. The plurality of operation areas 3 may be positioned in a staggered pattern. The multiple operation areas 3 include, for example, five operation areas 3A, 3B, 3C, 3D, and 3E. That is, in the operation panel 1, the main surface 1a includes, for example, five operation areas 3A, 3B, 3C, 3D, and 3E. The number of operation areas 3 is not limited to five. The number of operation areas 3 may be two or more. The five operation areas 3A, 3B, 3C, 3D, and 3E are positioned, for example, in a line. The five operation areas 3A, 3B, 3C, 3D, and 3E are positioned, for example, at intervals of 20 mm.

[0028] The plurality of piezoelectric sensors 10 are arranged on the main surface 1b of the operation panel 1. The plurality of piezoelectric sensors 10 are arranged on the back side of the main surface 1a. Each of the plurality of piezoelectric sensors 10 is fixed to the main surface 1b. Each piezoelectric sensor 10 and the main surface 1b are fixed, for example, by a joining member 7. The joining member 7 includes, for example, a double-sided pressure-sensitive adhesive tape or an adhesive. Fixing each piezoelectric sensor 10 to the main surface 1b includes, for example, bonding each piezoelectric sensor 10 to the main surface 1b. The number of piezoelectric sensors 10 corresponds to the number of operation areas 3. The number of piezoelectric sensors 10 is, for example, the same as the number of operation areas 3. For example, when the main surface 1a includes a first main surface, the main surface 1b includes a second main surface.

[0029] Each of the multiple piezoelectric sensors 10 is arranged to correspond to a corresponding operation area 3 among the multiple operation areas 3. Each of the multiple piezoelectric sensors 10 is arranged on the back side of the corresponding operation area 3. In a configuration in which the multiple operation areas 3 are arranged at a predetermined pitch along a predetermined direction, the multiple piezoelectric sensors 10 are also arranged at a predetermined pitch along the predetermined direction, corresponding to the multiple operation areas 3. In a configuration in which the multiple operation areas 3 are arranged in a line in a one-dimensional direction, the multiple piezoelectric sensors 10 are also arranged in a line in the one-dimensional direction, corresponding to the multiple operation areas 3. In a configuration in which the multiple operation areas 3 are arranged in a matrix in a two-dimensional direction, the multiple piezoelectric sensors 10 are also arranged in a matrix in the two-dimensional direction, corresponding to the multiple operation areas 3. In a configuration in which the multiple operation areas 3 are arranged in a staggered pattern, the multiple piezoelectric sensors 10 are also arranged in a staggered pattern, corresponding to the multiple operation areas 3.

[0030] The plurality of piezoelectric sensors 10 includes, for example, five piezoelectric sensors 10A, 10B, 10C, 10D, and 10E. That is, the operation unit OU includes, for example, five piezoelectric sensors 10A, 10B, 10C, 10D, and 10E. Piezoelectric sensor 10A is arranged to correspond to operation area 3A. Piezoelectric sensor 10A is arranged on the back side of operation area 3A. Piezoelectric sensor 10B is arranged to correspond to operation area 3B. Piezoelectric sensor 10B is arranged on the back side of operation area 3B. Piezoelectric sensor 10C is arranged to correspond to operation area 3C. Piezoelectric sensor 10C is arranged on the back side of operation area 3C. Piezoelectric sensor 10D is arranged to correspond to operation area 3D. Piezoelectric sensor 10D is arranged on the back side of operation area 3D. Piezoelectric sensor 10E is arranged to correspond to operation area 3E. Piezoelectric sensor 10E is arranged on the back side of operation area 3E. The five piezoelectric sensors 10A, 10B, 10C, 10D, and 10E are positioned, for example, in a line. The five piezoelectric sensors 10A, 10B, 10C, 10D, and 10E are arranged, for example, at a pitch of 20 mm.

[0031] Each of the plurality of piezoelectric sensors 10 (10A, 10B, 10C, 10D, 10E) includes, for example, a base plate 11, a piezoelectric element 13, and a wiring member 15. The operation unit OU includes the plurality of piezoelectric elements 13. The plurality of piezoelectric sensors 10 (10A, 10B, 10C, 10D, 10E) have the same configuration. Each of the piezoelectric sensors 10 (10A, 10B, 10C, 10D, 10E) may include, for example, a pressure sensor disclosed in Patent Document 1.

[0032] The base plate 11 is fixed to the main surface 1b. Fixing the base plate 11 to the main surface 1b realizes fixing of the piezoelectric sensor 10 to the main surface 1b. Fixing the base plate 11 to the main surface 1b may include bonding the base plate 11 to the main surface 1b. The base plate 11 is electrically insulated from the operation panel 1. The base plate 11 is made of, for example, a conductive metal material. The base plate 11 is made of, for example, a Ni-Fe alloy, Ni, brass, or stainless steel. The base plate 11 has, for example, a rectangular shape in a plan view. The base plate 11 may have, for example, a square shape in a plan view. The base plate 11 may have, for example, a circular shape in a plan view. The base plate 11 may be configured as a vibration plate. The base plate 11 includes a pair of main surfaces facing each other. One of the main surfaces is fixed to the main surface 1b. A piezoelectric element 13 is disposed on the other main surface.

[0033] The piezoelectric element 13 includes a piezoelectric body 14 and a pair of external electrodes (not shown). Each of the plurality of piezoelectric elements 13 includes a corresponding piezoelectric body 14 from the plurality of piezoelectric bodies 14. The piezoelectric body 14 has, for example, a rectangular parallelepiped shape. The rectangular parallelepiped shape includes a shape with chamfered corners and ridges, or a shape with rounded corners and ridges. The piezoelectric element 13 is disposed on the other main surface of the base plate 11, for example, with the center of the piezoelectric body 14 and the center of the base plate 11 approximately aligned. The base plate 11 and the piezoelectric element 13 are fixed together, for example, by double-sided pressure-sensitive adhesive tape or adhesive. Fixing the base plate 11 and the piezoelectric element 13 includes, for example, bonding the base plate 11 and the piezoelectric element 13 together.

[0034] The piezoelectric body 14 includes a pair of principal surfaces that face each other. One of the pair of principal surfaces included in the piezoelectric body 14 faces the base plate 11. The pair of principal surfaces included in the piezoelectric body 14 have the same shape as each other in a plan view of the piezoelectric element 13. The pair of principal surfaces included in the piezoelectric body 14 have, for example, a square shape with the length of one side shorter than the length of one side of the base plate 11. The piezoelectric body 14 has, for example, a thickness that is greater than the thickness of the base plate 11. In a plan view of the piezoelectric element 13, the center of the piezoelectric body 14 approximately coincides with the center of the base plate 11. In a plan view of the piezoelectric element 13, each side of the piezoelectric body 14 is approximately parallel to a corresponding one of the multiple sides of the base plate 11.

[0035] The piezoelectric body 14 may be formed of, for example, a single piezoelectric layer. In other words, the piezoelectric element 13 does not need to include internal electrodes disposed within the piezoelectric body 14. The piezoelectric body 14 is formed of a piezoelectric ceramic material. Examples of the piezoelectric ceramic material include PZT [Pb(Zr,Ti)O3], PT(PbTiO3), PLZT [(Pb,La)(Zr,Ti)O3], PZN [Pb(Zn,Nb)O3], or barium titanate (BaTiO3). The piezoelectric body 14 may be formed of, for example, a sintered ceramic green sheet containing the above-mentioned piezoelectric ceramic material. An electric charge is generated in the piezoelectric body 14 in response to the displacement of the piezoelectric body 14.

[0036] Each of the pair of external electrodes is disposed on a corresponding one of a pair of principal surfaces of the piezoelectric body 14. Each external electrode is, for example, thin plate-shaped or thin film-shaped. Each external electrode includes a conductive material. The conductive material includes, for example, Ag, Pd, or an Ag-Pd alloy. Each external electrode is formed, for example, from a sintered body of a conductive paste containing the above-described conductive material. One external electrode disposed on one principal surface of the piezoelectric body 14 is in partial direct contact with the base plate 11 when the base plate 11 and the piezoelectric element 13 are fixed together. The direct contact between the base plate 11 and the one external electrode establishes an electrical connection between the base plate 11 and the one external electrode. The base plate 11 and the piezoelectric element 13, i.e., the base plate 11 and the one external electrode, may be fixed together using, for example, a conductive adhesive or a conductive film.

[0037] The wiring member 15 includes a pair of conductors. Each of the pair of conductors is connected to a corresponding one of the pair of external electrodes. Each of the pair of conductors includes one end connected to the corresponding external electrode. One end of each conductor is physically and electrically connected to the corresponding external electrode. The corresponding conductors (one ends) and the external electrode are connected to each other by, for example, a conductive bonding material. The conductive bonding material includes, for example, solder, a conductive paste, or a conductive film. The conductive paste includes, for example, an anisotropic conductive paste. The conductive film includes, for example, an anisotropic conductive film. Each of the pair of conductors is connected to the control unit CU. Each of the pair of conductors includes the other end connected to the control unit CU. The other end of each conductor is electrically connected to the control unit CU. The other end of each conductor may be physically and electrically connected to the control unit CU, for example, via a connecting member. The connecting member includes, for example, a connector.

[0038] The wiring member 15 electrically connects the piezoelectric sensor 10 (piezoelectric element 13) and the control unit CU. The operation unit OU outputs a signal corresponding to the charge generated in the piezoelectric body 14. The signal corresponding to the charge generated in the piezoelectric body 14, output from the operation unit OU, is input to the control unit CU through the wiring member 15. Each conductor is made of, for example, copper. The wiring member 15 may include a base on which the pair of conductors is disposed, and a cover disposed on the base so as to cover the pair of conductors. The base and the cover are made of a non-conductive material. The non-conductive material includes, for example, polyimide resin. The wiring member 15 includes, for example, an FPC (Flexible Printed Circuit).

[0039] The operation unit OU may include a current / voltage converter. The current / voltage converter converts the charge generated in the piezoelectric body 14 into a voltage signal. The operation unit OU outputs, for example, a voltage signal as a signal corresponding to the charge generated in the piezoelectric body 14. The voltage signal is, for example, an analog signal. The operation unit OU may include an amplifier circuit. The amplifier circuit amplifies the voltage signal converted by the current / voltage converter.

[0040] The control unit CU is, for example, configured by a computer system. The computer system physically includes, for example, a processor (arithmetic circuit), a memory, a communication interface, and a data storage unit. The memory includes, for example, a read-only memory (ROM) and a random access memory (RAM). The data storage unit includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). The control unit CU may be, for example, configured by a microcontroller or an integrated circuit.

[0041] The control unit CU, for example, executes a program stored in the memory in the CPU to perform a process of determining the piezoelectric body 14 (piezoelectric sensor 10) corresponding to the operation area 3 operated by the operating object. By this process, the control unit CU includes the functional elements shown in Fig. 3. That is, the control unit CU includes a determination unit 20. The determination unit 20 determines, from among the plurality of piezoelectric sensors 10, the piezoelectric sensor 10 that corresponds to the operation area 3 operated by the operating object, based on the signal output from the operation unit OU. That is, the determination unit 20 determines, from among the piezoelectric bodies 14 included in the plurality of piezoelectric sensors 10, the piezoelectric body 14 that corresponds to the operation area 3 operated by the operating object, based on the signal output from the operation unit OU.

[0042] The control unit CU includes, for example, an A / D converter ADC. The A / D converter ADC converts an analog signal input to the control unit CU into a digital signal. The A / D converter ADC converts a voltage signal corresponding to the charge generated in the piezoelectric body 14, which is output as an analog signal from the operation unit OU, into a digital signal. The A / D converter ADC outputs the converted digital signal to the determination unit 20. Therefore, the determination unit 20 acquires voltage data obtained by converting the voltage signal corresponding to the charge generated in the piezoelectric body 14 into digital data. The voltage data includes, for example, a value based on the signal output from the operation unit OU (the voltage signal corresponding to the charge generated in the piezoelectric body 14).

[0043] The determination unit 20 compares a value based on the signal output from the operation unit OU with a threshold value. The threshold value includes, for example, an upward threshold value and a downward threshold value. The upward threshold value and the downward threshold value may be the same or different. The determination unit 20 determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object, for example, based on information regarding the timing at which the value based on the signal output from the operation unit OU changes from a state where it is greater than the downward threshold value to a state where it is equal to or less than the downward threshold value. The control unit CU recognizes the operation area 3 operated by the operating object based on the determination result of the determination unit 20. The control unit CU controls the operation of the electric device so that the electric device performs an operation corresponding to the operation area 3 operated by the operating object, for example.

[0044] An example of the operation of the control unit CU will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a flowchart showing an example of control processing in the input device. Fig. 5 is a diagram showing an example of control processing in the input device. The control processing shown in Fig. 4 is periodically executed, for example, when the power of the electrical equipment is turned on. This control processing includes executing a flag setting process and executing a flag release process. The determination unit 20 acquires voltage data of each piezoelectric sensor 10 at a predetermined sampling period in a routine separate from the control process shown in Fig. 4. That is, the determination unit 20 acquires voltage data of all piezoelectric sensors 10A, 10B, 10C, 10D, and 10E at a predetermined sampling period.

[0045] The decision unit 20 determines whether or not the flag setting process has been completed (S11 in FIG. 4). When the decision unit 20 determines that the flag setting process has not been completed, i.e., that the flag setting process has not yet been executed, the decision unit 20 compares the acquired voltage data with the rising threshold for each piezoelectric sensor 10, i.e., for each piezoelectric body 14. As a result of the comparison, the decision unit 20 determines whether or not a predetermined period has elapsed since the timing at which any one of the acquired voltage data became equal to or greater than the rising threshold (S12 in FIG. 4). The predetermined period is, for example, 3 msec. To determine whether the flag setting process has been completed, for example, an execution completion flag is used. For example, the determination unit 20 sets the execution completion flag when the flag setting process has been completed, and clears the execution completion flag when the flag clearing process has been completed.

[0046] When the determination unit 20 determines that a predetermined period has elapsed since any one of the voltage data items became equal to or greater than the rising threshold, the determination unit 20 executes a flag setting process (S13 in FIG. 4). In the flag setting process, the determination unit 20 compares the acquired voltage data with the rising threshold for each piezoelectric sensor 10 (piezoelectric body 14). For each piezoelectric sensor 10 (piezoelectric body 14), if the voltage data remains equal to or greater than the rising threshold after a predetermined period has elapsed since the voltage data became equal to or greater than the rising threshold, the determination unit 20 sets a flag at the time the predetermined period has elapsed. In the flag setting process, the determination unit 20 does not set a flag for a piezoelectric sensor 10 whose voltage data does not transition to a state equal to or greater than the rising threshold. The determination unit 20 also does not set a flag for a piezoelectric sensor 10 whose voltage data transitions to a state below the rising threshold before the predetermined period has elapsed since the voltage data became equal to or greater than the rising threshold. The flag setting process is executed, for example, as a routine separate from the control process shown in FIG. 4. For example, when the determination unit 20 completes the flag setting process, it sets an execution completion flag.

[0047] When the determination unit 20 determines that the flag setting process has been completed, the determination unit 20 compares the acquired voltage data with the falling threshold for each piezoelectric sensor 10, i.e., for each piezoelectric body 14. As a result of the comparison, the determination unit 20 determines whether any one of the acquired voltage data has transitioned from a state greater than the falling threshold to a state equal to or less than the falling threshold (S14 in FIG. 4). The falling threshold may be the same as or different from the rising threshold.

[0048] When the determination unit 20 determines that any one of the voltage data will transition from a state greater than the falling threshold to a state equal to or less than the falling threshold, the determination unit 20 performs a flag release process (S15 in FIG. 4). In the flag release process, the determination unit 20 compares the acquired voltage data with the falling threshold for each piezoelectric sensor 10 (piezoelectric body 14). The determination unit 20 releases the flag for each piezoelectric sensor 10 (piezoelectric body 14) at the timing when the voltage data transitions from a state greater than the falling threshold to a state equal to or less than the falling threshold. When all the set flags have been cleared, the decision unit 20 ends the flag clearing process. The flag clearing process is executed, for example, by a routine separate from the control process shown in Fig. 4. When the flag clearing process is completed, the decision unit 20 clears the execution end flag, for example.

[0049] Thereafter, the determination unit 20 determines the piezoelectric sensor 10 corresponding to the operation area 3 operated by the operating object (S16 in FIG. 4). The determination unit 20 determines the piezoelectric sensor 10 (piezoelectric body 14) whose flag is released latest as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. In other words, the determination unit 20 determines the piezoelectric sensor 10 (piezoelectric body 14) whose timing of transitioning to a state equal to or lower than the falling threshold latest as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. The control unit CU determines, based on the determination result of the determination section 20, that the operation area 3 corresponding to the piezoelectric sensor 10 whose flag is released latest is the operation area 3 operated by the operating object. The release of the set flag corresponds to information regarding the timing at which the value based on the signal output from the operation unit OU changes from a state greater than the falling threshold to a state equal to or less than the falling threshold.

[0050] 5 shows an example of a control process in the input device ID when the operation area 3C is operated by the operating object. In this example, the rising threshold and the falling threshold are set to the same threshold Sh. When the operation area 3C is operated by the operation object, an external force is applied to the piezoelectric sensor 10C corresponding to the operation area 3C. The external force is caused by the force applied to the operation area 3C by the operation object. When the external force is applied to the piezoelectric sensor 10C corresponding to the operation area 3C, the piezoelectric element 14 included in the piezoelectric sensor 10C corresponding to the operation area 3C is displaced, and an electric charge is generated in the piezoelectric element 14 of the piezoelectric sensor 10C. The operation unit OU outputs a signal corresponding to the electric charge generated in the piezoelectric element 14 of the piezoelectric sensor 10C. The change in voltage data corresponding to the signal corresponding to the electric charge generated in the piezoelectric element 14 of the piezoelectric sensor 10C is shown by profile P1.

[0051] The external force may also be applied to piezoelectric sensors 10A, 10B, 10D, and 10E other than piezoelectric sensor 10C. When the external force is applied to piezoelectric sensors 10A, 10B, 10D, and 10E other than piezoelectric sensor 10C, the piezoelectric elements 14 included in each of piezoelectric sensors 10A, 10B, 10D, and 10E are displaced, and an electric charge is generated in each piezoelectric element 14. As shown in FIG. 5, the operation unit OU outputs a signal corresponding to the electric charge generated in the piezoelectric element 14 of each piezoelectric sensor 10A, 10B, 10D, and 10E. Profile P2 shows the change in voltage data corresponding to the signal corresponding to the electric charge generated in the piezoelectric element 14 of piezoelectric sensors 10B and 10D. Profile P3 shows the change in voltage data corresponding to the signal corresponding to the electric charge generated in the piezoelectric element 14 of piezoelectric sensors 10A and 10E. The external force tends to decrease the farther away from the operation area 3. The magnitude of the voltage data corresponding to the piezoelectric element 14 of piezoelectric sensor 10C is greater than the magnitude of the voltage data corresponding to the piezoelectric element 14 of each of piezoelectric sensors 10A, 10B, 10D, and 10E. The magnitude of the voltage data corresponding to the piezoelectric element 14 of each of piezoelectric sensors 10A and 10E is smaller than the magnitude of the voltage data corresponding to the piezoelectric element 14 of each of piezoelectric sensors 10B and 10D.

[0052] The determination unit 20 sets a flag for each of the piezoelectric sensors 10A, 10B, 10C, 10D, and 10E when the voltage data remains equal to or greater than the threshold Sh for a predetermined period Tp after the voltage data reaches or exceeds the threshold Sh. The determination unit 20 clears the flag for each of the piezoelectric sensors 10A, 10B, 10C, 10D, and 10E when the voltage data changes from being greater than the threshold Sh to being equal to or less than the threshold Sh. As shown in FIG. 5, the flag is cleared latest for the voltage data corresponding to the piezoelectric sensor 10C (piezoelectric body 14). Therefore, the determination unit 20 determines that the piezoelectric sensor 10C (piezoelectric body 14) is the piezoelectric sensor (piezoelectric body) corresponding to the operation area 3C operated by the operating object. The control unit CU determines that the operation area 3C corresponding to the piezoelectric sensor 10C (piezoelectric body 14) has been operated by the operating object.

[0053] Another example of the operation of the control unit CU will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a flowchart showing another example of the control processing in the input device. Fig. 7 is a diagram showing another example of the control processing in the input device. The control processing shown in Fig. 6 is also executed periodically, for example, when the power of the electrical equipment is turned on, similar to the control processing shown in Fig. 4. The control processing shown in Fig. 6 includes executing a period counting process. The determination unit 20 acquires voltage data of each piezoelectric sensor 10 at a predetermined sampling period in a routine separate from the control process shown in Fig. 6. That is, the determination unit 20 acquires voltage data of all piezoelectric sensors 10A, 10B, 10C, 10D, and 10E at a predetermined sampling period.

[0054] The determination unit 20 compares the acquired voltage data with the rising threshold for each piezoelectric sensor 10, i.e., for each piezoelectric body 14. As a result of the comparison, the determination unit 20 determines whether any one of the acquired voltage data has transitioned from a state where it is smaller than the rising threshold to a state where it is equal to or greater than the rising threshold (S21 in FIG. 6).

[0055] When the determination unit 20 determines that any one of the voltage data will transition from a state smaller than the rising threshold to a state equal to or greater than the rising threshold, the determination unit 20 executes a period counting process (S22 in FIG. 6). In the period counting process, the determination unit 20 compares the acquired voltage data with the rising threshold for each piezoelectric sensor 10 (piezoelectric body 14). For each piezoelectric sensor 10 (piezoelectric body 14), the determination unit 20 starts counting the period that has elapsed since the voltage data became equal to or greater than the rising threshold at the time the voltage data transitions from a state smaller than the rising threshold to a state equal to or greater than the rising threshold. The determination unit 20 does not start counting for piezoelectric sensors 10 whose voltage data does not transition to a state equal to or greater than the rising threshold.

[0056] The determination unit 20 compares the acquired voltage data with the falling threshold for each piezoelectric sensor 10 (piezoelectric body 14) for which counting has started. For each piezoelectric sensor 10 (piezoelectric body 14), the determination unit 20 stops counting the period that has elapsed since the voltage reached or exceeded the rising threshold at the timing when the voltage transitions from being greater than the falling threshold to being equal to or less than the falling threshold. The determination unit 20 stores the counted value for each piezoelectric sensor 10 (piezoelectric body 14) for which counting has been stopped. The larger the counted value, the longer the period that has elapsed since the voltage reached or exceeded the rising threshold. The counted value corresponds to the period from when the value based on the signal output from the operation unit OU reaches or exceeds the rising threshold to when it falls below the falling threshold. When all the counting that has been performed is completed, the determination unit 20 ends the period counting process. The period counting process is executed, for example, in a routine separate from the control process shown in FIG.

[0057] Thereafter, the determination unit 20 determines the piezoelectric sensor 10 corresponding to the operation area 3 operated by the operating object (S23 in FIG. 6). The determination unit 20 determines the piezoelectric sensor 10 (piezoelectric body 14) with the largest count value as the piezoelectric sensor 10 corresponding to the operation area 3 operated by the operating object. In other words, the determination unit 20 determines the piezoelectric sensor 10 (piezoelectric body 14) with the latest timing to transition to a state below the falling threshold as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. Based on the determination result of the determination section 20, the control unit CU determines that the operation area 3 corresponding to the piezoelectric sensor 10 having the longest period from the time when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold to the time when it becomes equal to or less than the falling threshold is the operation area 3 operated by the operating object. The period from the time when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold to the time when it becomes equal to or less than the falling threshold corresponds to information regarding the time when the value based on the signal output from the operation unit OU changes from a state where it is greater than the falling threshold to a state where it is equal to or less than the falling threshold.

[0058] 7 shows an example of control processing by the input device ID when the operation area 3C is operated by the operating object. In this example, the rising threshold and the falling threshold are the same threshold Sh. 7, as in FIG. 5, the change in voltage data corresponding to the signal according to the charge generated in the piezoelectric body 14 of the piezoelectric sensor 10C is shown by profile P1. The change in voltage data corresponding to the signal according to the charge generated in the piezoelectric body 14 of the piezoelectric sensors 10B and 10D is shown by profile P2. The change in voltage data corresponding to the signal according to the charge generated in the piezoelectric body 14 of the piezoelectric sensors 10A and 10E is shown by profile P3.

[0059] The determination unit 20 starts counting the period elapsed from the time when the piezoelectric sensor 10A, 10B, 10C, 10D, and 10E changes from a state below the threshold Sh to a state above the threshold Sh, for each of the piezoelectric sensors 10A, 10B, 10C, 10D, and 10E. The determination unit 20 stops counting the period elapsed from the time when the piezoelectric sensor 10A, 10B, 10C, 10D, and 10E changes from a state above the threshold Sh to a state below the threshold Sh, for each of the piezoelectric sensors 10A, 10B, 10C, 10D, and 10E. As shown in FIG. 7, the counted value is the largest in the voltage data corresponding to the piezoelectric sensor 10C (piezoelectric body 14). Therefore, the determination unit 20 determines that the piezoelectric sensor 10C (piezoelectric body 14) is the piezoelectric sensor (piezoelectric body) corresponding to the operation area 3C operated by the operating object. The control unit CU determines that the operation area 3C corresponding to the piezoelectric sensor 10C (piezoelectric body 14) has been operated by the operating object.

[0060] 5 and 7, the operation unit OU including the piezoelectric sensor 10 (piezoelectric body 14) has high responsiveness from when an external force is applied to the piezoelectric sensor 10 (piezoelectric body 14) until a signal corresponding to the charge generated in the piezoelectric body 14 is output from the operation unit OU. Therefore, when comparing the timing at which the voltage data changes from a state below the threshold Sh to a state above the threshold Sh between the piezoelectric sensor 10C (piezoelectric body 14) and the piezoelectric sensors 10A, 10B, 10D, and 10E (piezoelectric body 14), the interval between these timings is short. It is difficult to distinguish between the timing based on the signal corresponding to the charge generated in the piezoelectric sensor 10C (piezoelectric body 14) and the timing based on the signal corresponding to the charge generated in the piezoelectric sensors 10A, 10B, 10D, and 10E (piezoelectric body 14). Therefore, in a configuration in which the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body is determined based on information regarding the timing at which the voltage data changes from a state below the threshold value Sh to a state above the threshold value Sh, there is a risk that the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body will not be determined appropriately.

[0061] 5 and 7, when comparing the voltage data of piezoelectric sensor 10C with that of piezoelectric sensors 10A, 10B, 10D, and 10E, the voltage data corresponding to piezoelectric sensor 10C (piezoelectric body 14) is greater than the voltage data corresponding to piezoelectric sensors 10A, 10B, 10D, and 10E (piezoelectric body 14). Due to the difference in voltage data, when comparing the timing at which the voltage data changes from a state where it is greater than threshold value Sh to a state where it is equal to or less than threshold value Sh, the interval between these timings is large for piezoelectric sensor 10C (piezoelectric body 14) and piezoelectric sensors 10A, 10B, 10D, and 10E (piezoelectric body 14). Therefore, in a configuration in which the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body is determined based on information regarding the timing at which the voltage data changes from a state greater than the threshold value Sh to a state less than the threshold value Sh, the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body can be appropriately determined.

[0062] Based on the difference in the magnitude of the voltage data, it is possible to determine the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operation object. However, for example, in a configuration in which the control unit CU includes a microcontroller, it is difficult for the microcontroller to obtain voltage data higher than the power supply voltage of the microcontroller. The upper limit of the voltage data obtained by the microcontroller is restricted by the power supply voltage of the microcontroller. Therefore, in a configuration in which the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body is determined based on the difference in the magnitude of the voltage data, there is a risk that the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body will not be determined appropriately.

[0063] The control unit CU (determination section 20) determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object, based on information regarding the timing at which a value based on a signal corresponding to the charge generated in the piezoelectric sensor 10 (piezoelectric body 14) transitions from a state where the value is greater than the lower threshold to a state where the value is equal to or less than the lower threshold. Therefore, even if the operation unit OU is configured to include a plurality of piezoelectric sensors 10 (piezoelectric bodies 14), the input device ID appropriately determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0064] The control unit CU (determination unit 20) may set a flag for each piezoelectric sensor 10 (piezoelectric body 14) based on the timing when a value based on a signal output from the operation unit OU becomes equal to or greater than an increasing threshold, and may clear the flag based on the timing when the value becomes equal to or greater than a decreasing threshold. The control unit CU (determination unit 20) may acquire the state of the flag as information related to the timing when a value based on a signal corresponding to an electric charge generated in the piezoelectric sensor 10 (piezoelectric body 14) changes from a state greater than the decreasing threshold to a state equal to or less than the decreasing threshold. The control unit CU (determination unit 20) may determine the piezoelectric sensor 10 (piezoelectric body 14) whose flag is cleared latest as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. As described above, the control unit CU (determination section 20) is configured to determine the piezoelectric sensor 10 (piezoelectric body 14) whose flag is released latest as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body, thereby appropriately and reliably determining the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body.

[0065] The control unit CU (decision section 20) may set the flag after a predetermined period has elapsed since the time when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold. Even when an external force due to a disturbance is applied to multiple piezoelectric sensors 10 (piezoelectric bodies 14), charges are generated in the piezoelectric bodies 14, and the operation unit OU outputs a signal according to the charges generated in the piezoelectric bodies 14. If a value based on the signal output from the operation unit OU is greater than the rising threshold, the control unit CU sets a flag. Therefore, even though an external force due to a disturbance is applied to multiple piezoelectric sensors 10 (piezoelectric bodies 14), the control unit CU determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. The disturbance includes, for example, an unintended momentary contact with the main surface 1a or a mechanical vibration transmitted to the operation panel 1 from outside. The configuration in which the control unit CU (determination unit 20) sets a flag after a predetermined period has elapsed since the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold makes it difficult to set a flag when an external force due to a disturbance is transmitted to multiple piezoelectric sensors 10 (piezoelectric bodies 14). Therefore, this configuration more appropriately determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0066] The control unit CU (determination unit 20) may acquire, for each piezoelectric sensor 10 (piezoelectric body 14), the period from when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold to when it becomes equal to or less than the falling threshold, as information related to the timing at which the value based on the signal corresponding to the charge generated in the piezoelectric sensor 10 (piezoelectric body 14) changes from a state where it is greater than the falling threshold to a state where it is equal to or less than the falling threshold. The control unit CU (determination unit 20) may determine the piezoelectric sensor 10 (piezoelectric body 14) having the longest period from when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold to when it becomes equal to or less than the falling threshold as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. As described above, the control unit CU (determination section 20) is configured to determine the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body as the piezoelectric sensor 10 (piezoelectric body 14) having the longest period from the time when the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold to the time when it becomes equal to or less than the falling threshold, thereby appropriately and reliably determining the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body.

[0067] The control unit CU (determination section 20) may determine the piezoelectric sensor 10 (piezoelectric body 14) that transitions to a state below the falling threshold latest as the piezoelectric sensor 10 (piezoelectric body 14) that corresponds to the operation area 3 operated by the operating object. A configuration in which the control unit CU (determination unit 20) determines the piezoelectric sensor 10 (piezoelectric body 14) that is latest to transition to a state below the descending threshold as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body appropriately and reliably determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating body.

[0068] As described above, the control process in the input device ID is determined based on information regarding the timing at which the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object changes from a state in which the value based on the signal corresponding to the charge generated in the piezoelectric body 14 is greater than the lower threshold to a state in which the value is equal to or less than the lower threshold. Therefore, even if the operation unit OU is configured to include multiple piezoelectric sensors 10 (piezoelectric bodies 14), the control process in the input device ID appropriately determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0069] In the control process in the input device ID, as described above, determining the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object includes determining the piezoelectric sensor 10 (piezoelectric body 14) whose flag is released latest as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. Therefore, the control process in the input device ID appropriately and reliably determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0070] In the control process in the input device ID, as described above, setting a flag includes setting the flag after a predetermined period has elapsed since the value based on the signal output from the operation unit OU becomes equal to or greater than the rising threshold. Therefore, in the control process in the input device ID, when an external force due to a disturbance is transmitted to multiple piezoelectric sensors 10 (piezoelectric bodies 14), the flag is unlikely to be set. The control process in the input device ID more appropriately determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0071] In the control process in the input device ID, as described above, determining the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object includes determining the piezoelectric sensor 10 (piezoelectric body 14) having the longest period from the time when the value based on the signal corresponding to the charge generated in the piezoelectric sensor 10 (piezoelectric body 14) becomes equal to or greater than the rising threshold to the time when it becomes equal to or less than the falling threshold as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. Therefore, the control process in the input device ID appropriately and reliably determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0072] In the control process in the input device ID, as described above, determining the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object includes determining the piezoelectric sensor 10 (piezoelectric body 14) that is latest to transition to a state below the falling threshold as the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object. Therefore, the control process in the input device ID appropriately and reliably determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0073] The above describes embodiments and modifications of the present invention, but the present invention is not necessarily limited to the above-described embodiments and modifications, and various modifications are possible without departing from the spirit of the present invention.

[0074] The flag may be set at the timing when a value based on a signal corresponding to the charge generated in the piezoelectric sensor 10 (piezoelectric body 14) becomes equal to or greater than the rising threshold value. The configuration in which the flag is set when a predetermined time has elapsed since the value based on the signal corresponding to the charge generated in the piezoelectric sensor 10 (piezoelectric body 14) becomes equal to or greater than the rising threshold is, as described above, less susceptible to the influence of external forces due to disturbances. Therefore, the control unit CU (determination section 20) more appropriately determines the piezoelectric sensor 10 (piezoelectric body 14) corresponding to the operation area 3 operated by the operating object.

[0075] The operation unit OU does not have to include a plurality of piezoelectric sensors 10, i.e., a plurality of piezoelectric elements 13. The operation unit OU may include a piezoelectric sensor array (piezoelectric element array) including a plurality of piezoelectric bodies 14, instead of a plurality of piezoelectric sensors 10 (a plurality of piezoelectric elements 13). The piezoelectric sensor 10 may include a piezoelectric ceramic sensor or a piezoelectric film sensor.

[0076] As can be understood from the above description of the embodiments and modifications, the present specification includes disclosure of the following aspects. (Appendix 1) an operation unit including an operation surface operated by an operation body and a plurality of piezoelectric bodies arranged on the back side of the operation surface, and outputting a signal corresponding to an electric charge generated in each of the plurality of piezoelectric bodies; a control unit that determines, based on the signal output from the operation unit, a piezoelectric element that corresponds to an operated portion on the operation surface among the plurality of piezoelectric elements; The control unit determines the piezoelectric element corresponding to the operated portion on the operation surface based on information regarding the timing at which the value based on the signal transitions from a state greater than a falling threshold to a state less than the falling threshold. (Appendix 2) The control unit setting a flag for each of the plurality of piezoelectric bodies based on the timing at which the value based on the signal becomes equal to or greater than an increasing threshold, resetting the flag based on the timing at which the value becomes equal to or greater than the decreasing threshold, and acquiring the state of the flag as the information; 2. The input device according to claim 1, wherein the piezoelectric element that has the latest flag released is determined to be the piezoelectric element that corresponds to the operated portion on the operation surface. (Appendix 3) 3. The input device according to claim 2, wherein the control unit sets the flag when a predetermined period of time has elapsed since the value based on the signal becomes equal to or greater than the rising threshold. (Appendix 4) The control unit acquiring, for each of the plurality of piezoelectric bodies, a period from when the value based on the signal becomes equal to or greater than an increasing threshold to when the value becomes equal to or less than the decreasing threshold as the information; 2. The input device according to claim 1, wherein the piezoelectric element having the longest period is determined to be the piezoelectric element corresponding to the operated portion on the operation surface. (Appendix 5) the operation unit includes a plurality of piezoelectric elements; 5. The input device according to claim 1, wherein each of the plurality of piezoelectric elements includes a corresponding one of the plurality of piezoelectric bodies. (Appendix 6) the operation unit includes a panel including a first main surface including the operation surface and a second main surface opposite to the first main surface, 6. The input device according to claim 5, wherein the plurality of piezoelectric elements are arranged on the second main surface. (Appendix 7) An input device described in any one of Appendices 1 to 6, wherein the control unit determines the piezoelectric element that has the latest timing to transition to a state below the falling threshold as the piezoelectric element that corresponds to the operated portion on the operation surface. (Appendix 8) A method for controlling an input device, comprising: the input device is provided with an operation unit including an operation surface operated by an operation object and a plurality of piezoelectric bodies arranged on a back surface of the operation surface, the operation unit outputting a signal based on an electric charge generated in each of the plurality of piezoelectric bodies; acquiring the signal output from the operation unit; acquiring information about a timing at which a value based on the acquired signal transitions from a state greater than a falling threshold to a state equal to or less than the falling threshold; determining, based on the acquired information, a piezoelectric element among the plurality of piezoelectric elements that corresponds to the operated portion on the operation surface. (Appendix 9) acquiring the information includes setting a flag for each of the plurality of piezoelectric bodies based on a timing when the value based on the signal becomes equal to or greater than an increasing threshold, resetting the flag based on a timing when the value becomes equal to or greater than the decreasing threshold, and acquiring a state of the flag as the information; 9. The control method for an input device according to claim 8, wherein determining the piezoelectric element includes determining the piezoelectric element whose flag is released the latest as the piezoelectric element corresponding to the operated portion on the operation surface. (Appendix 10) 10. The method for controlling an input device according to claim 9, wherein setting the flag includes setting the flag after a predetermined period of time has elapsed from the timing at which the value based on the signal becomes equal to or greater than the rising threshold. (Appendix 11) acquiring the information includes acquiring, for each of the plurality of piezoelectric bodies, a period from when the value based on the signal becomes equal to or greater than an increasing threshold to when the value becomes equal to or less than the decreasing threshold as the information; 9. The control method for an input device described in Appendix 8, wherein determining the piezoelectric body includes determining the piezoelectric body with the longest period as the piezoelectric body corresponding to the operated portion on the operation surface. (Appendix 12) A control method for an input device described in any one of Appendices 8 to 11, wherein determining the piezoelectric body includes determining the piezoelectric body that has the latest timing to transition to a state below the falling threshold as the piezoelectric body that corresponds to the operated portion on the operation surface. [Explanation of symbols]

[0077] 1...operation panel, 1a, 1b...main surface, 3, 3A, 3B, 3C, 3D, 3E...operation area, 13...piezoelectric element, 14...piezoelectric body, 20...decision section, CU...control unit, ID...input device, OU...operation unit.

Claims

1. an operation unit including an operation surface operated by an operation body and a plurality of piezoelectric bodies arranged on the back side of the operation surface, and outputting a signal corresponding to an electric charge generated in each of the plurality of piezoelectric bodies; a control unit that determines, based on the signal output from the operation unit, a piezoelectric element that corresponds to an operated portion on the operation surface among the plurality of piezoelectric elements; The control unit determines the piezoelectric element corresponding to the operated portion on the operation surface based on information regarding the timing at which the value based on the signal transitions from a state greater than a falling threshold to a state less than the falling threshold.

2. The control unit setting a flag for each of the plurality of piezoelectric bodies based on the timing at which the value based on the signal becomes equal to or greater than an increasing threshold, resetting the flag based on the timing at which the value becomes equal to or greater than the decreasing threshold, and acquiring the state of the flag as the information; The input device according to claim 1 , wherein the piezoelectric element for which the flag is released latest is determined to be the piezoelectric element corresponding to the operated portion on the operation surface.

3. The input device according to claim 2 , wherein the control unit sets the flag when a predetermined period has elapsed since the value based on the signal becomes equal to or greater than the rising threshold.

4. The control unit acquiring, for each of the plurality of piezoelectric bodies, a period from when the value based on the signal becomes equal to or greater than an increasing threshold to when the value becomes equal to or less than the decreasing threshold as the information; The input device according to claim 1 , wherein the piezoelectric element having the longest period is determined as the piezoelectric element corresponding to the operated portion on the operation surface.

5. the operation unit includes a plurality of piezoelectric elements; 5. The input device according to claim 1, wherein each of the plurality of piezoelectric elements includes a corresponding one of the plurality of piezoelectric bodies.

6. the operation unit includes a panel including a first main surface including the operation surface and a second main surface opposite to the first main surface, The input device according to claim 5 , wherein the plurality of piezoelectric elements are arranged on the second main surface.

7. The input device according to claim 1 , wherein the control unit determines the piezoelectric element that has the latest timing of transitioning to a state below the falling threshold as the piezoelectric element that corresponds to the operated portion on the operation surface.

8. A method for controlling an input device, comprising: the input device is provided with an operation unit including an operation surface operated by an operation body and a plurality of piezoelectric bodies arranged on a back surface of the operation surface, the operation unit outputting a signal based on an electric charge generated in each of the plurality of piezoelectric bodies; acquiring the signal output from the operation unit; acquiring information about a timing at which a value based on the acquired signal transitions from a state greater than a falling threshold to a state equal to or less than the falling threshold; determining, based on the acquired information, a piezoelectric element among the plurality of piezoelectric elements that corresponds to the operated portion on the operation surface.

9. acquiring the information includes setting a flag for each of the plurality of piezoelectric bodies based on a timing when the value based on the signal becomes equal to or greater than an increasing threshold, resetting the flag based on a timing when the value becomes equal to or greater than the decreasing threshold, and acquiring a state of the flag as the information; 9. The control method for an input device according to claim 8, wherein determining the piezoelectric element includes determining the piezoelectric element whose flag is released the latest as the piezoelectric element corresponding to the operated portion on the operation surface.

10. 10. The control method for an input device according to claim 9, wherein setting the flag includes setting the flag after a predetermined period has elapsed from the timing at which the value based on the signal becomes equal to or greater than the rising threshold.

11. acquiring the information includes acquiring, for each of the plurality of piezoelectric bodies, a period from when the value based on the signal becomes equal to or greater than an increasing threshold to when the value becomes equal to or less than the decreasing threshold as the information; The control method for an input device according to claim 8 , wherein determining the piezoelectric body includes determining the piezoelectric body with the longest period as the piezoelectric body corresponding to the operated portion on the operation surface.

12. 9. The control method for an input device according to claim 8, wherein determining the piezoelectric body includes determining the piezoelectric body that has the latest timing of transitioning to a state below the falling threshold as the piezoelectric body that corresponds to the operated portion on the operation surface.

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