Operation detection device

Abstract

To provide an operation detector capable of accurately detecting a pressing operation without being affected by a temperature change even when a dummy gauge is provided in the vicinity of an operation part.SOLUTION: In an operation detector 1, operation parts 10-40 are provided on the front side of an operation panel 100, and active gauges 10A-40A and dummy gauges 10D-40D are arranged on the back side of the operation parts 10-40 so as to be under the same temperature environment. The operation detector includes Wheatstone bridge circuits 210-240 composed of the active gauge in each operation part and the dummy gauge provided in an operation part different from the operation part provided with the active gauge.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an operation detection device. [Background technology]

[0002] A commonly known means for detecting a pressing operation on an operation panel is to provide a strain gauge on the rear side of the face plate of the operation panel and detect the pressing operation on the operation panel from the amount of strain detected by the strain gauge. However, when detecting a pressing operation using a strain gauge, there is a possibility of erroneous detection occurring because the resistance value of the strain gauge changes with temperature. In the piezoelectric element disclosed in Patent Document 1, a bridge circuit is formed by an active gauge, which is a strain gauge for measuring displacement, and a dummy gauge placed in the same temperature environment as the active gauge, and the change in resistance value of the strain gauge due to temperature is offset to prevent erroneous detection. In this case, the dummy gauge is placed in a position where almost no strain occurs even if the active gauge is deformed by receiving a force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 03-235001 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of a flat operation panel that is subjected to a large operating force by the user, it is difficult to arrange a dummy gauge in a position where little distortion occurs due to pressing the operation panel, and further to arrange an active gauge in a position near the dummy gauge where the temperature environment is the same. For example, one location for a dummy gauge where distortion does not occur due to a large operating force applied to the operation panel is the edge of the operation panel. However, because heating elements such as LEDs for illuminating the operation section are provided near the operation section of the operation panel, the temperature environment differs between the operation section where the active gauge is provided and the edge of the operation panel, creating the problem that pressing operations on the operation section cannot be accurately detected.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide an operation detection device equipped with an operation panel that can accurately detect pressing operations without being affected by temperature changes, even when a dummy gauge is provided near the operation unit. [Means for solving the problem]

[0006] Form 1: One or more embodiments of the present invention include an operation panel and a Ta A plurality of operation units; A plurality of heating elements are disposed on a substrate provided on the rear side of the operation panel; an active gauge and a dummy gauge provided on the rear side of each of the plurality of operation units; and a Wheatstone bridge circuit including the active gauge of one of the plurality of operation units and a dummy gauge provided in another operation unit different from the operation unit in which the active gauge is provided. The plurality of heat generating elements that operate at the same timing are arranged so that the distances to the active gauge and the distances to the dummy gauge that are paired with each other are the same, and the interiors of the plurality of operating parts are configured to be in the same temperature environment. An operation detection device is proposed.

[0007] In one or more embodiments of the present invention, the operation detection device includes a plurality of operation units provided on the front side of an operation panel, and an active gauge and a dummy gauge disposed on the rear side of the operation units so as to be in the same temperature environment. The operation detection device further includes a Wheatstone bridge circuit configured with the active gauge of each operation unit and a dummy gauge provided in a different operation unit from the operation unit in which the active gauge is provided. In other words, since the pressing operation is detected based on the output voltage of a Wheatstone bridge circuit composed of an active gauge and a dummy gauge, which are in the same temperature environment, even if the dummy gauge is provided on the back of the operating unit, the pressing operation can be accurately detected without being affected by temperature changes.

[0009] form 2 One or more embodiments of the present invention propose an operation detection device in which the Wheatstone bridge circuit is configured with the active gauge and the dummy gauge, each of which is provided at two operating units that are not adjacent to each other among the multiple operating units. That is, the Wheatstone bridge circuit is composed of non-adjacent active gauges and dummy gauges. Therefore, even when a user performs a pressing operation and a load is applied to the active gauge, the load applied to the dummy gauge can be reduced. With this, when an operating portion is pressed, only the output voltage of the Wheatstone bridge circuit corresponding to the pressed operating portion changes, so that the pressing operation can be accurately detected. Effect of the Invention

[0010] According to one or more embodiments of the present invention, even if a dummy gauge is provided near an operating unit, it is possible to accurately detect a pressing operation without being affected by temperature changes. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing a configuration of an operation detection device according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing an operation panel of an operation detection device according to an embodiment of the present invention; [Diagram 3] 2 is a cross-sectional view showing the AA section of the operation panel of the operation detection device according to the embodiment of the present invention. [Figure 4]2 is a diagram showing a circuit of a Wheatstone bridge circuit unit of the operation detection device according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Embodiment> An operation detection device 1 according to this embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0013] <Configuration of operation detection device 1> The operation detection device 1 according to this embodiment is a device that detects operation instructions from a user, such as changing the strength of an air conditioning fan of a vehicle air conditioner or switching operation modes, and as shown in FIG. 1, is configured to include an operation panel 100, a Wheatstone bridge circuit section 200, and a CPU 300.

[0014] <Configuration of operation panel 100> The operation panel 100 includes operation units 10-40. As shown in FIG. 2, operation unit 10 and operation unit 20 are operation units for changing the strength of the air conditioning fan, and the user changes the strength of the air conditioning fan by pressing near icon 11 on operation unit 10 and icon 21 on operation unit 20. Furthermore, operation units 30 and 40 are operation units for changing the operation mode of the air conditioning, and the user changes the operation mode of the air conditioning by pressing the vicinity of icon 31 on operation unit 30 and icon 41 on operation unit 40.

[0015] An active gauge and a dummy gauge for detecting a user's pressure are disposed on the back surface of each operation section of operation panel 100. Here, active gauge 10A and dummy gauge 10D are disposed in operation section 10. Active gauge 20A and dummy gauge 20D are disposed in operation section 20. Active gauge 30A and dummy gauge 30D are disposed in operation section 30. Active gauge 40A and dummy gauge 40D are disposed in operation section 40. For example, as shown in FIG. 3, on the rear side of the pressing operation area of ​​the operation unit 10, a dummy gauge 10D for detecting a pressing operation and an active gauge 10A (not shown) are disposed. For example, strain gauges are used as the active gauges 10A to 40A and the dummy gauges 10D to 40D. The resistance value of the strain gauge changes when the user applies pressure to it, and the user's pressure can be detected by detecting the change in resistance value. The method of detecting the pressing operation will be described later.

[0016] As shown in FIG. 2, LEDs 10L to 40L are provided directly below the rear surfaces of the icons 11 to 41, respectively, so that the icons 11 to 41 on the operation units 10 to 40 can be recognized even at night. For example, as shown in FIG. 3, the LED 10L is mounted on a board 150 disposed on the back side of the operation panel 100, and illuminates the icon 11. The LEDs 10L to 40L are supplied with the same current value to light up the LEDs 10L to 40L, and are all turned on and off at the same timing.

[0017] Here, since the LEDs 10L to 40L generate heat when turned on, the temperature around the LEDs rises, and further, the temperature around the active gauges 10A to 40A and the dummy gauges 10D to 40D also rises. In the operation detection device 1 of this embodiment, in order to make the temperatures around the active gauges 10A-40A and the dummy gauges 10D-40D all uniform, the distance between the LEDs, which are the heat-generating elements of each operation part, and the active gauges and the distance between the LEDs, which are the heat-generating elements of each operation part, and the dummy gauges are arranged so that they are the same. The effect of changes in the temperature environment of the operation detection device 1 on the detection process will be described later.

[0018] <Configuration of Wheatstone Bridge Circuit Unit 200 and CPU 300> The configurations of the Wheatstone bridge circuit section 200 and the CPU 300 will be described with reference to FIG.

[0019] (Configuration of Wheatstone bridge circuit section 200) The Wheatstone bridge circuit section 200 is configured to include Wheatstone bridge circuits 210-240.

[0020] As shown in FIG. 4, the active gauges and dummy gauges constituting the Wheatstone bridge circuits 210 to 240 are each provided on an operation portion that is not adjacent to each other. For example, the Wheatstone bridge circuit 210 is composed of an active gauge 10A of the operation unit 10 and a dummy gauge 30D of the operation unit 30.

[0021] The Wheatstone bridge circuit 210 includes an active gauge 10A, a dummy gauge 30D, a resistor 211, a resistor 212, and an operational amplifier 213. One end of the active gauge 10A is connected to one end of the dummy gauge 30D and to a circuit power supply (5V). In the case of an operation detection device 1 mounted on a vehicle, after power is supplied to the CPU 300, the CPU 300 controls a switching element (not shown) to supply circuit power (5V) to the Wheatstone bridge circuit section 200. The other end of the active gauge 10 A is connected to one end of a resistor 211 and the positive input terminal of an operational amplifier 213 . The other end of the dummy gauge 30 D is connected to one end of a resistor 212 and the negative input terminal of an operational amplifier 213 . The other end of the resistor 211 is connected to the other end of the resistor 212 and to the ground. The output terminal of the operational amplifier 213 is connected to the CPU 300 .

[0022] The Wheatstone bridge circuit 220 includes an active gauge 20A, a dummy gauge 40D, a resistor 221, a resistor 222, and an operational amplifier 223. One end of the active gauge 20A is connected to one end of the dummy gauge 40D and to a circuit power supply (5V). The other end of the active gauge 20 A is connected to one end of a resistor 221 and the positive input terminal of an operational amplifier 223 . The other end of the dummy gauge 40 D is connected to one end of a resistor 222 and the negative input terminal of an operational amplifier 223 . The other end of the resistor 221 is connected to the other end of the resistor 222 and the ground. The output terminal of the operational amplifier 223 is connected to the CPU 300 .

[0023] The Wheatstone bridge circuit 230 includes an active gauge 30A, a dummy gauge 10D, a resistor 231, a resistor 232, and an operational amplifier 233. One end of the active gauge 30A is connected to one end of the dummy gauge 10D and to a circuit power supply (5V). The other end of the active gauge 30 A is connected to one end of a resistor 231 and the positive input terminal of an operational amplifier 233 . The other end of the dummy gauge 10 D is connected to one end of a resistor 232 and the negative input terminal of an operational amplifier 233 . The other end of the resistor 231 is connected to the other end of the resistor 232 and to the ground. The output terminal of the operational amplifier 233 is connected to the CPU 300 .

[0024] The Wheatstone bridge circuit 240 includes an active gauge 40A, a dummy gauge 20D, a resistor 241, a resistor 242, and an operational amplifier 243. One end of the active gauge 40A is connected to one end of the dummy gauge 20D and to a circuit power supply (5V). The other end of the active gauge 40 A is connected to one end of a resistor 241 and the positive input terminal of an operational amplifier 243 . The other end of the dummy gauge 20 D is connected to one end of a resistor 242 and the negative input terminal of an operational amplifier 243 . The other end of the resistor 241 is connected to the other end of the resistor 242 and to the ground. The output terminal of the operational amplifier 243 is connected to the CPU 300 .

[0025] Here, the active gauges 10A to 40A and the dummy gauges 10D to 40D need to have the same characteristics, and therefore use the same components. Furthermore, resistors 211, 212, 221, 222, 231, 232, 241 and 242 have the same resistance value (resistance value when there is no strain) as that of active gauges 10A to 40A and dummy gauges 10D to 40D.

[0026] The above-mentioned operational amplifiers 213 , 223 , 233 and 243 are differential amplifier circuits that amplify the voltage generated from the change in resistance value of the strain gauge due to the pressing operation by the user, and the output voltage thereof is connected to the CPU 300 . The circuit operation of the Wheatstone bridge circuit section 200 will be described in detail later.

[0027] (CPU300 Configuration) The CPU 300 includes a detection unit 310 . The detection unit 310 is a part of a function of a CPU 300 that includes a well-known RAM, a ROM, an I / O bus, and the like (not shown). The CPU 300 controls the entire operation detection device 1 in accordance with a control program stored in the ROM. A CPU power supply (5V) is supplied to the CPU 300 in conjunction with an ACC (accessory) switch or an IG (ignition) switch. When the CPU power supply (5V) is supplied to the CPU 300, the processing of the operation detection device 1 is started, and when the CPU power supply (5V) is cut off, the processing of the operation detection device 1 is ended. The detection unit 310 detects the output voltage V210 ~V 240 A pressing operation by the user is detected based on the above.

[0028] <Effect of temperature environment change on the Wheatstone bridge circuit section 200> The strain gauges used in the active gauges 10A to 40A and the dummy gauges 10D to 40D are generally made of metal foil, and the metal foil is deformed by the pressure of the pressing operation, causing a change in the resistance value. In addition, since the metal foil of the strain gauge expands and contracts depending on the temperature environment, the resistance value changes in accordance with changes in the temperature environment even when there is no pressing operation. The following describes the effect of changes in temperature environment on the Wheatstone bridge circuit section 200 in the operation detection device 1 according to this embodiment.

[0029] Here, a Wheatstone bridge circuit 210 is illustrated and described. The resistance value of resistor 211 and resistor 212 is R, and the resistance value of active gauge 10A is R 10A , the resistance value of the dummy gauge 30D is R 30D , the voltage at the positive input terminal of the operational amplifier 213 is V A1 , the voltage at the negative input terminal of the operational amplifier 213 is V D1 , the gain of the operational amplifier 213 is G amp When the output voltage V of the Wheatstone bridge circuit 210 is 210 can be expressed by the following equation 1.

[0030]

number

[0031] Here, in the operation detection device 1 according to this embodiment, the distance between the LED 10L, which is the heat source, and the active gauge 10A is the same as the distance between the dummy gauge 30D and the LED 30L, so the active gauge 10A and the dummy gauge 30D are in the same temperature environment. Therefore, the resistance value R of the active gauge 10A 10Aand the resistance value R of the dummy gauge 30D 30D will have the same value. In other words, the output voltage V of the Wheatstone bridge circuit 210 210 is not affected by temperature and always remains near 0V.

[0032] <Operations of the Wheatstone Bridge Circuit Unit 200 and the Detection Unit 310 During Pressing Operation> The following describes the circuit operation of the Wheatstone bridge circuit section 200 when the user presses the operation section 10.

[0033] In the operation detection device 1 according to this embodiment, each operation unit is provided with an active gauge and a dummy gauge, so that when an operation unit is pressed, the resistance values ​​of the active gauge and the dummy gauge change. For example, when the operating unit 10 is pressed, the resistance values ​​of the active gauge 10A and the dummy gauge 10D change.

[0034] The resistance value of the active gauge 10A when the operating unit 10 is pressed is R 10A(push) , the resistance value of the dummy gauge 30D that is not pressed is R 30D , the resistance value of resistor 211 and resistor 212 is R, and the amplification factor of operational amplifier 213 is G amp , the voltage at the positive input terminal of the operational amplifier 213 is V A1 , the voltage at the negative input terminal of the operational amplifier 213 is V D1 When the output voltage V of the Wheatstone bridge circuit 210 is 210 can be expressed by the following equation 2.

[0035]

number

[0036] Here, when the operation unit 10 is pressed, the dummy gauge 30D is not pressed. 30D Let the resistance value of R be R in the formula 2. 30DSubstituting R into the above, the output voltage V of the Wheatstone bridge circuit 210 is 210 can be expressed by the following equation 3.

[0037]

number

[0038] On the other hand, the resistance value of the dummy gauge 10D when the operation unit 10 is pressed is R 10D(push) The resistance value of the active gauge 30A that is not pressed is R 30A , the resistance value of resistor 231 and resistor 232 is R, and the amplification factor of operational amplifier 233 is G amp , the voltage at the positive input terminal of the operational amplifier 233 is V A3 , the voltage at the negative input terminal of the operational amplifier 233 is V D3 When the output voltage V of the Wheatstone bridge circuit 230 is 230 can be expressed by the following equation 4.

[0039]

number

[0040] Here, when the operating unit 10 is pressed, the active gauge 30A is not pressed. 30A Let the resistance value of R be R in the formula 4. 30A Substituting R into the above, the output voltage V of the Wheatstone bridge circuit 230 is 230 can be expressed by the following equation 5.

[0041]

number

[0042] Here, the operational amplifiers 213, 223, 233, and 243 are operational amplifiers that operate on the CPU power supply (5V) with the ground level as a reference, and therefore output a value of 0 to 5V at the output of each operational amplifier. In other words, the above V 230This value does not result in a negative output voltage, and 0V is output to the output of the operational amplifier 233.

[0043] As described above, when none of the operating portions are pressed, 0 V is output to the output of all the Wheatstone bridge circuits, regardless of changes in the temperature environment. Furthermore, when each operating portion is pressed, the resistance values ​​of the active gauge and the dummy gauge change, and the output voltage of the Wheatstone bridge circuit changes. However, in the operation detection device 1 according to this embodiment, the output of each Wheatstone bridge circuit has a value between 0 and 5 V, so that only the output of the Wheatstone bridge circuit including the active gauge arranged in the operation unit that is pressed changes from 0 V. That is, the detection unit 310 detects the output voltage V 210 ~V 240 When the voltage becomes greater than a predetermined value, it is determined that a pressing operation has been performed.

[0044] <Actions and Effects> As described above, the operation detection device 1 of this embodiment includes an operation panel 100, operation units 10-40 formed on the front side of the operation panel 100 and configured to have the same temperature environment inside, active gauges 10A-40A and dummy gauges 10D-40D provided on the back side of each of the operation units 10-40, and a Wheatstone bridge circuit unit 200 composed of an active gauge in one of the operation units 10-40 and a dummy gauge provided in an operation unit other than the operation unit in which the active gauge is provided.

[0045] In the operation detection device 1 according to this embodiment, operation units 10-40 are provided on the front side of an operation panel 100, and active gauges 10A-40A and dummy gauges 10D-40D are arranged on the back side of the operation units 10-40 so as to be in the same temperature environment. Furthermore, the operation detection device 1 includes a Wheatstone bridge circuit section 200 constituted by the active gauges of each operation unit and a dummy gauge provided in an operation unit different from the operation unit in which the active gauge is provided. In other words, since the pressing operation is detected based on the output voltage of the Wheatstone bridge circuit section 200 composed of the active gauges 10A to 40A and the dummy gauges 10D to 40D, which are under the same temperature environment, even if the dummy gauges 10D to 40D are provided on the back side of the operating section 10 to 40, the pressing operation can be accurately detected without being affected by temperature changes.

[0046] In the operation detection device 1 according to this embodiment, heat generating elements that operate at the same timing are provided near the operation units 10 to 40, respectively, so that the insides of the operation units 10 to 40 are in the same temperature environment. The operation detection device 1 according to this embodiment is provided with LEDs 10L to 40L on the back side of the operation panel 100 for illuminating the icons 11 to 41 of the operation units 10 to 40, and the LEDs 10L to 40L are turned on at the same time. In other words, heat generating elements (LEDs 10L-40L) that operate at the same timing are arranged near each of the operating units 10-40, so that the active gauges 10A-40A and dummy gauges 10D-40D arranged in the operating units 10-40 can be placed in the same temperature environment. Therefore, the resistance values ​​of the active gauges 10A to 40A and the dummy gauges 10D to 40D when no pressing operation is being performed are all the same, so that the pressing operation can be accurately detected without being affected by temperature changes.

[0047] In the operation detection device 1 according to this embodiment, the Wheatstone bridge circuit section 200 is composed of an active gauge and a dummy gauge provided in each of two operation sections that are not adjacent to each other among the operation sections 10 to 40. In other words, since each Wheatstone bridge circuit is composed of an active gauge and a dummy gauge that are not adjacent to each other, even when the active gauge is pressed and a load is applied thereto, the load applied to the dummy gauge can be reduced. Therefore, when an operating portion is pressed, the output voltage changes only in the Wheatstone bridge circuit corresponding to the pressed operating portion, so that the pressing operation can be accurately detected.

[0048] <Modification> In the operation detection device 1 described above, the Wheatstone bridge circuit is composed of an active gauge and a dummy gauge provided on two of the multiple operation parts that are not adjacent to each other. However, if there is no effect of the load on the adjacent operation parts when a pressing operation is performed, the Wheatstone bridge circuit may be composed of an active gauge and a dummy gauge provided on two adjacent operation parts. In other words, when the change in resistance between the active gauge and the dummy gauge arranged in an operating section adjacent to the operating section that is pressed is small, a Wheatstone bridge circuit may be formed by the active gauge and the dummy gauge respectively provided in two adjacent operating sections. In addition, the above-mentioned operation detection device 1 is configured to include four operation units and four Wheatstone bridge circuits, but the number is not limited to this as long as the inside of each operation unit is configured to be in the same temperature environment. More specifically, it is sufficient to have at least two operation units and two Wheatstone bridge circuits, and it may be configured to have more than four operation units and Wheatstone bridge circuits. Furthermore, in the above-mentioned operation detection device 1, the operation units are configured to be formed in parallel in the horizontal direction to the operation panel, but as long as the inside of each operation unit is configured to be in the same temperature environment, the configuration is not limited to this, and each operation unit may be configured to be formed in parallel in the vertical or diagonal direction to the operation panel.

[0049] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Explanation of symbols]

[0050] 1; Operation detection device 10~40;Operation unit 10A~40A; Active Gauge 10D~40D; dummy gauge 10L~40L; LED 100;Operation panel 150; Substrate 200; Wheatstone bridge circuit section 210~240; Wheatstone bridge circuit 300;CPU 310: Detection unit

Claims

1. An operation panel; A plurality of operation units formed on a front side of the operation panel; A plurality of heating elements are disposed on a substrate provided on the rear side of the operation panel; an active gauge and a dummy gauge provided on the rear side of each of the plurality of operation units; a Wheatstone bridge circuit including the active gauge of one of the plurality of operation units and a dummy gauge provided in another operation unit different from the operation unit in which the active gauge is provided; Equipped with The multiple heat generating elements which operate at the same time are arranged so that the distance to the active gauge which forms a pair with each of them and the distance to the dummy gauge are the same, and the operation detection device is configured so that the insides of the multiple operating parts are in the same temperature environment.

2. 2. The operation detection device according to claim 1, wherein the Wheatstone bridge circuit is configured with the active gauge and the dummy gauge, each of which is provided in two of the plurality of operation units that are not adjacent to each other.

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