Touch sensor, air conditioning, or lighting device

Abstract

To improve an operability of a touch sensor of a self capacity detection type driven by an insulation power supply.SOLUTION: A touch area T that has to be touched by a user with one operation, is divided into an electrode pattern S111 of a region of a part and a GND pattern S112 of a residual region. Then at the time of a touch operation by a user 5, a GND potential GND2 of a parasitic capacitance Cp on a touch sensor S side can be matched to a GND potential GND1 of an electrostatic capacity Cm on the user side by coupling the GND pattern S112 with the user 5 in a capacitance Csg. Thus, a sensor value is stabilized; a touch operation can be detected at a sufficient sensibility; and a good operability can be obtained.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a touch sensor, an air conditioning device, or a lighting device. [Background technology]

[0002] Touch sensors are now being used not only in touch panels such as those found in smartphones, but also in home appliances, facility equipment, etc. In such equipment applications, touch sensors are used because they are less likely to get dirty or damaged than conventional membrane switches, and because they are more durable and have better design.

[0003] In the above-mentioned touch panel applications, it is necessary to detect where on the panel the user has touched, and whether multiple places are being touched at the same time, and therefore a mutual capacitance type touch sensor is used. On the other hand, in the above-mentioned device applications, a self-capacitance detection type touch sensor has been used for some time. A self-capacitance detection type touch sensor is shown in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-211898 A

[0005] [overview] In a self-capacitance detection touch sensor, when a human body touches an electrode pattern formed in a specified touch area with one operation (one touch), the electrode pattern is connected to the GND through the human body, and a capacitance (Cm) is generated between the two, detecting the contact of the human body. In more detail, in a self-capacitance detection touch sensor, the electrode pattern forms a parasitic capacitance (Cp) between it and the GND electrode, which also serves as a shield on the back, and when the human body touches it, the capacitance Cm is connected in parallel, and the contact is detected from the change in capacitance.

[0006] Here, in the case of air conditioners and lighting equipment, for example, the touch sensor is provided on an operation panel on a wall, and the user who operates it is connected to the GND relatively well. On the other hand, the GND electrode on the equipment side, i.e., the touch sensor, is connected to the GND of the power supply. In that case, if the GND on the power supply side is not obtained (if it is not connected to the neutral line), the GND potential of the touch sensor will deviate from the GND potential of the human body. Specifically, such a deviation in GND potential is likely to occur when the power supply of the touch sensor is an insulated power supply, that is, a power supply having an insulating transformer between it and the commercial power supply side. If the GND potential deviates, the increase in the capacitance Cm caused by the human body is not detected, and as a result, the sensor value of the touch sensor becomes unstable or it becomes difficult to obtain sufficient sensitivity, resulting in poor operability, i.e., a state in which the touch sensor does not react even when touched.

[0007] An object of the present disclosure is to provide a self-capacitance detection touch sensor driven by an isolated power supply that can provide good operability, and to provide an air conditioning or lighting device that uses the same.

[0008] In order to solve the above-mentioned problems, the touch sensor of the present disclosure is a self-capacitance detection type touch sensor driven by an isolated power supply, which has a touch area that a user must touch in one operation to achieve a desired function, and the touch area has an electrode pattern formed by partitioning off a portion of the touch area, and a GND pattern formed in the remaining area of ​​the partitioned touch area, spaced apart from the electrode pattern, and electrically insulated from the electrode pattern, and when the user touches the touch area, the GND pattern is capacitively coupled to the user, thereby matching the GND potential between the electrostatic capacitance on the user side and the parasitic capacitance on the touch sensor side. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the electrical configuration of an air conditioner using a touch sensor according to an embodiment. [Diagram 2]FIG. 2 is a diagram illustrating a cross-sectional structure of a touch sensor of a reference example. [Diagram 3] FIG. 3 is an equivalent circuit diagram of the touch sensor of FIG. [Figure 4] FIG. 4 is a front view showing an example of an electrode pattern of a touch sensor of a reference example. [Diagram 5] FIG. 5 is a front view showing another example of the electrode pattern of the touch sensor of the reference example. [Figure 6] FIG. 6 is a waveform diagram showing an example of a touch sensor output of a reference example. [Figure 7] FIG. 7 is a diagram illustrating a cross-sectional structure of the touch sensor according to the embodiment. [Figure 8] FIG. 8 is an equivalent circuit diagram of the touch sensor of FIG. [Figure 9] FIG. 9 is a front view showing an example of an electrode pattern of the touch sensor according to the embodiment. [Figure 10] FIG. 10 is a front view showing another example of the electrode pattern of the touch sensor according to the embodiment. [Figure 11] FIG. 11 is a waveform diagram showing an example of a touch sensor output according to the embodiment. [Figure 12] FIG. 12 is a waveform diagram showing an example of a touch sensor output of the comparative example.

[0010] [Detailed Description] Next, the present embodiment will be described with reference to the drawings. In the description of the drawings described below, the same or similar parts are given the same or similar reference numerals. However, it should be noted that the drawings are schematic and may differ from the actual ones. Therefore, the specific structure, dimensions, etc. should be appropriately determined by taking into consideration the following description.

[0011] The following embodiments are merely examples of devices and methods for embodying the technical ideas, and do not specify the materials, shapes, structures, arrangements, etc. of the components. Various modifications can be made to the present embodiments within the scope of the claims.

[0012] 1 is a block diagram showing the electrical configuration of an air conditioner 1 that uses touch sensors S1, S2, and S3 (hereinafter, collectively referred to as S) according to an embodiment. The touch sensor S of this embodiment can be used not only in air conditioners 1 but also in a wide range of equipment such as lighting equipment, particularly in its operation panels P1, P2, P3, ... (hereinafter, collectively referred to as P). Compared to membrane switches and the like, the touch sensor S is less likely to get dirty or damaged, and is also preferable in terms of design.

[0013] The touch sensor S is a self-capacity detection type touch sensor that includes touch areas T1, T2, and T3 (hereinafter collectively referred to as T) that the user touches in one operation to realize a desired function, and detects the touch operation by a change in capacitance. In the example of Fig. 1, the touch sensor S1 indicates the desired function for turning the power on or off, and the touch sensors S2 and S3 indicate the desired functions for decreasing or increasing the temperature, respectively.

[0014] The operation panel P is installed (or embedded) on a wall surface 2 in one or more rooms or in some sections thereof. The operation panel P is connected to a host controller U via a LAN (Local Area Network) cable 3. The host controller U causes a display device 11 of the operation panel P to display the control state of the corresponding load (air conditioner), and controls the load (air conditioner) via a load control panel (not shown) in response to a touch operation on a touch sensor S.

[0015] For this reason, the operation panel P is provided with a control device 12 configured with a microcomputer and its peripheral circuits, and the upper controller U is also provided with a control device 21 configured with a microcomputer and its peripheral circuits. The control device 12 drives the display device 11, detects touch operations on the touch sensor S, and communicates with the control device 21 of the controller U via a signal line 31 of the LAN cable 3.

[0016] In air conditioners 1 configured in this manner, the operation panel P may have its own power supply, but when it is not directly connected to the air conditioner main body but is controlled via a host controller U, it is often powered by the host controller U. Such control by the host controller U is preferable especially when multiple air conditioner main bodies and operation panels P are provided. In this embodiment, the operation panel P is connected to the host controller U by a LAN cable 3, and therefore power can be supplied to the operation panel P via the power lines 32, 33 of this LAN cable 3, which is preferable as it makes it possible to omit a separate power supply.

[0017] In the upper controller U, AC current, for example 100V, from the commercial power source 4 is stepped down to a predetermined low-voltage DC current by a rectifier circuit 22 and a DC-DC converter 23, and power is supplied. The output current of the DC-DC converter 23 is stepped down to a predetermined low voltage by an LDO (Low Drop Out) regulator (also called a low-loss linear regulator or a low-saturation linear regulator) 25, and used in the upper controller U. The output current of the DC-DC converter 23 is also supplied to the operation panel P via the power lines 32 and 33 of the LAN cable 3, and is stepped down to a predetermined low voltage by the LDO regulator 13, and power is supplied to the control circuit 12, the display device 11, and the like.

[0018] Here, the host controller U must supply power to many operation panels P, and in relation to the power supply capacity, etc., the DC-DC converter 23 is often an isolated power supply equipped with an isolation transformer 24 such as an LLC converter. In this case, the GND potential GND2 of the operation panel P is separated from the actual GND (neutral line) potential GND1 of the commercial power supply 4 on the host controller U side from the power line 33. Therefore, even if the LDO regulator 13 is a non-isolated power supply, it ends up being an isolated power supply.

[0019] Fig. 2 is a diagram showing a schematic cross-sectional structure of a touch sensor S0 of a reference example, and Fig. 3 is an equivalent circuit diagram of the touch sensor S0 of Fig. 2. The touch sensor S0 is configured such that the surface side of a substrate S01 is covered with a covering material S02 that serves as a housing, and a GND electrode S03 that also serves as a shield is formed on the back side. An electrode pattern S011 is formed in a touch area T of the substrate S01, and an electrically insulated GND pattern S012 is formed on the periphery of the touch area T. Examples of the electrode pattern S011 and the GND pattern S012 are as shown in Figs. 4 and 5. In the example of Fig. 4, the electrode pattern S011 is rectangular, and in the example of Fig. 5, it is circular.

[0020] When the human body 5 touches the electrode pattern S011 formed on the touch area T, the self-capacitance detection touch sensor S0 detects the contact of the human body by connecting the electrode pattern S011 to the GND (GND1) through the human body 5 and generating a capacitance Cm between the two. That is, when the human body 5 touches the electrode pattern S011, the electrode pattern S011 is grounded through the capacitance Cm. In the example of FIG. 2, a covering material S02 is interposed between the electrode pattern S011 and the human body 5, so that a parasitic capacitance Cs of the covering material S02 is generated, and a series capacitance Cs+Cm is connected between the electrode pattern S011 and the GND (GND1). The parasitic capacitance Cs is determined by the material of the covering material S02, such as plastic, and the thickness. Meanwhile, a parasitic capacitance Cp is formed between the electrode pattern S011 and the GND electrode S03 (GND2). Therefore, when the human body 5 is not in contact with the electrode pattern S011, only the parasitic capacitance Cp is connected to the sensor input terminal Sin of the control circuit 12, and when contact is made, the series capacitance Cs+Cm is connected in parallel to the parasitic capacitance Cp, making it possible to detect the contact.

[0021] However, since the operation panel P is driven by an insulated power supply as described above, a deviation may occur between the GND potential GND1 on the human body 5 side and the GND potential GND2 on the operation panel P side as shown in FIG. 1. Then, even if the human body 5 touches the electrode pattern S011, the sensor value may not be stable or sufficient sensitivity may be difficult to obtain, as shown in FIG. 6. FIG. 6 is a waveform diagram showing an example of the sensor output when the human body 5 touches the electrode pattern S01. In FIG. 6, the vertical axis indicates the sensor output, and the horizontal axis indicates the time, and the experimental results of four subjects are shown. The sensor output is at a level below the contact detection threshold Vth for all four subjects. In addition, the sensor output is large at the time of contact when the capacitance changes due to the characteristics of the capacitance sensor, but then decreases and fluctuates. Therefore, it can be understood that if the sensitivity is increased, that is, the threshold Vth is lowered, even if the contact can be detected once, the fluctuation may cause the sensor to erroneously detect non-contact.

[0022] Therefore, in this embodiment, the self-capacitance detection type touch sensor S driven by an insulated power supply as described above is configured as follows. Fig. 7 is a diagram showing a schematic cross-sectional structure of the touch sensor S of this embodiment, and Fig. 8 is an equivalent circuit diagram of the touch sensor S of Fig. 7. Figs. 7 and 8 correspond to Figs. 2 and 3, respectively. The touch sensor S of this embodiment is configured such that the surface side of the substrate S01 is covered with a covering material S02 that serves as a housing, and a GND electrode S03 that also serves as a shield or the like is formed on the back side. This touch sensor S is similar to the touch sensor S0 shown in Figs. 2, 4, and 5 in that a predetermined touch area T is set on the substrate S01, and a GND pattern S12 is formed on the periphery of the touch area T.

[0023] However, in the touch sensor S of this embodiment, as shown in Fig. 9 and Fig. 10, the touch area T is divided, a part of the area is the electrode pattern S111, and the remaining area is the GND pattern S112. As shown in Fig. 7, the GND pattern S112 is separated from and electrically insulated from the electrode pattern S111. Then, when the user 5 touches the touch area T, the GND pattern S112 is capacitively coupled with the user 5 by the electrostatic capacitance Csg formed between the GND pattern S112 and the user 5.

[0024] Therefore, in a situation where the human body 5 is not in contact with the electrode pattern S111, only a parasitic capacitance Cp is formed between the electrode pattern S111 and the GND electrode S3 (GND2) at the sensor input terminal Sin of the control circuit 12. On the other hand, when the human body 5 comes into contact, as shown in FIG. 8, a series circuit of the parasitic capacitance Cs of the covering material S02 interposed between the electrode pattern S111 and the human body 5 and the capacitance Cm of the human body 5 is connected to the sensor input terminal Sin, and the capacitance Csg is connected in parallel to the capacitance Cm. This allows the GND potential GND2 of the parasitic capacitance Cp on the touch sensor S side to match the GND potential GND1 of the capacitance Cm on the human body 5 side. Therefore, it is possible to accurately detect whether the capacitance Cm is connected, that is, whether the human body 5 is in contact.

[0025] FIG. 11 is a waveform diagram showing an example of a sensor output when the human body 5 touches the electrode pattern S111 of FIG. 9. In FIG. 11, as in FIG. 6, the vertical axis indicates the sensor output, and the horizontal axis indicates the time, showing the experimental results of four subjects. The sensor output of all four subjects is at a level equal to or higher than the contact detection threshold Vth. In addition, since the GND potential GND2 is approximately equal to the GND potential GND1 and is stable, it is understood that the sensor value is also stable during the contact period. Therefore, in the touch sensor S of this embodiment, it is possible to accurately detect contact without increasing the sensitivity unnecessarily, that is, without lowering the threshold Vth. For reference, FIG. 12 shows waveforms in the case where the DC-DC converter 23 of the upper controller U is a non-insulated power supply. The waveform of FIG. 11 in the touch sensor S of this embodiment using an insulating power supply is comparable to the waveform of the non-insulated power supply in FIG. 12, and therefore it is understood that the detection accuracy of the touch sensor S of this embodiment is comparable to the detection accuracy of a touch sensor using a non-insulated power supply.

[0026] 9 and 10 are front views showing an example of the electrode pattern S111 and the GND patterns S112 and S12. In Fig. 9 and Fig. 10, the GND pattern S12 surrounds a rectangular touch area T. The shape of the electrode pattern S111 formed in the rectangular touch area T is different between Fig. 9 and Fig. 10.

[0027] As described above, when dividing the touch area T into the electrode pattern S111 in a partial region and the GND pattern S112 in the remaining region, in the example of Fig. 9, the electrode pattern S111 is formed in a C-shape or a U-shape. Therefore, the GND patterns S112, S12 are formed so as to fill the inside and outside of the C-shape or the U-shape.

[0028] This increases the likelihood that a user will come into contact (touch) across the two patterns S111, S112, and even if the free ends S111a, S111b of the C-shape or U-shape are spaced apart from each other, they are electrically connected at the connecting portion S111c, allowing the use of a single wiring to the electrode pattern S111.

[0029] 10, the electrode pattern S111 is formed in a comb shape. Therefore, the GND pattern S112 is formed to fill the spaces between the teeth S111d of the comb. Even with this configuration, the possibility that the user will touch the two patterns S111 and S112 across each other increases, and even if the teeth S111d are spaced apart from each other, they are electrically connected at the tooth base S111e, making it possible to reduce the number of wiring lines to the electrode pattern S111 to one.

[0030] Since the touch area T is determined in advance, the electrode pattern S111 and the GND pattern S112 may be divided relatively arbitrarily without affecting the touch operation of the user 5. However, it is preferable that the division is not so extreme that either area is only a corner or a corner portion, and that a predetermined capacitance is obtained for the parasitic capacitance Cp and the electrostatic capacitance Csg. It is also preferable that the division of the electrode pattern S111 and the GND pattern S112 is such that the user 5 only needs to be aware of the touch area T, and does not need to be aware that he or she must touch (touch) both patterns S111 and S112. The division of the electrode pattern S111 and the GND pattern S112 may be determined in the above-mentioned preferable manner while taking into consideration the wiring arrangement and design.

[0031] The technical ideas that can be understood from this disclosure are described in the following appendices. Note that, for the purpose of aiding understanding, and not for the purpose of limiting the scope of the invention, the components described in the appendices are given the reference symbols of the corresponding components in the embodiments. The reference symbols are shown as examples for the purpose of aiding understanding, and the components described in each appendix should not be limited to the components indicated by the reference symbols.

[0032] <Appendix 1> The touch sensor (S) described in Appendix 1 is In a self-capacitance detection type touch sensor (S) driven by an isolated power supply (23, 13), The touch sensor (S) has a touch area (T) that a user (5) should touch in one operation to realize a desired function, and the touch area (T) is An electrode pattern (S111) formed by partitioning a part of the touch area (T); a GND pattern (S112) formed in a remaining area of ​​the touch area (T) and spaced apart from the electrode pattern (S111) and electrically insulated from the electrode pattern (S111); When a user (5) touches the touch area (T), the GND pattern (S112) is capacitively coupled (Csg) to the user (5), thereby matching the GND potential (GND1, GND2) between the electrostatic capacitance (Cm) on the user (5) side and the parasitic capacitance (Cp) on the touch sensor (S) side.

[0033] Therefore, the sensor value can be stabilized and a touch operation can be detected with sufficient sensitivity, resulting in good operability.

[0034] <Appendix 2> The touch sensor (S) according to claim 2 is the touch sensor (S) according to claim 1, The electrode pattern (S111) is formed in a C-shape or a U-shape.

[0035] Therefore, the user (5) is more likely to come into contact (touch) across the two patterns (S111, S112). Even if the free ends (S111a, S111b) of the C-shape or U-shape are spaced apart from each other, they are electrically connected at the connecting portion (S111c), and the number of wires to the electrode pattern (S111) can be reduced to one.

[0036] <Appendix 3> The touch sensor (S) according to claim 3 is the touch sensor (S) according to claim 1, The electrode pattern (S111) is formed in a comb shape.

[0037] Therefore, the user (5) is more likely to come into contact (touch) across the two patterns (S111, S112). Even if the comb teeth (S111d) are separated from each other, they are electrically connected at the base of the teeth (S111e), and the number of wires to the electrode pattern (S111) can be reduced to one.

[0038] <Appendix 4> The touch sensor (S) according to Supplementary Note 4 is the touch sensor (S) according to any one of Supplementary Notes 1 to 3, It is used in the control panel (P) of air conditioning or lighting equipment (1).

[0039] According to the above configuration, the operation panel (P) of the air conditioning or lighting equipment (1) is different from the touch panels of smartphones, tablet terminals, etc. in that the touch area (T) is predefined like an operation button, and the area of ​​the touch area (T) is relatively large.

[0040] Therefore, the touch sensor of the present disclosure, which divides the touch area (T) into the electrode pattern (S111) and the GND pattern (S112), can be suitably used.

[0041] <Appendix 5> The touch sensor (S) according to claim 5 is the touch sensor (S) according to any one of claims 1 to 4, Used as a wall switch.

[0042] According to the above configuration, the air conditioning or lighting operation panel (P) is often embedded in the wall surface (2). In such a case, the user (5) who operates it is well connected to the GND, but unlike the touch panels of smartphones, tablet terminals, etc., the operation panel (P) is only touched by the fingertip (5) to the sensor (S) surface, and there is little possibility of the housing (S2) being touched over a wide area.

[0043] Therefore, the present disclosure, which allows the GND (GND2) of the operation panel (5) to coincide with the user's GND (GND1), is extremely useful for wall switches.

[0044] <Appendix 6> An air conditioning or lighting device (1) according to Supplementary Note 6 uses a touch sensor (S) according to any one of Supplementary Notes 1 to 5.

[0045] According to the above configuration, even if a touch sensor that is resistant to dirt and damage is used for the operation panel (P) of the air conditioning or lighting device (1), which is often installed on a wall surface (2), the touch sensor (S) disclosed herein can stabilize the sensor value and detect touch operations with sufficient sensitivity.

[0046] <Appendix 7> The air conditioning or lighting equipment (1) according to Appendix 7 is the air conditioning or lighting equipment (1) according to Appendix 6, The insulated power supply (23) is provided in the upper controller (U), and the operation panel (P) is equipped with a non-insulated power supply (13).

[0047] Therefore, even if the operation panel (P) is a non-insulated power supply, the present disclosure is suitable when the upper controller (U) is an insulated power supply. [Explanation of symbols]

[0048] 1 Air conditioning equipment 11 Display device 12, 21 Control device 13, 25 LDO regulator 2. Wall 22 Rectifier circuit 23 DC-DC converter 24 Isolation transformer 3 LAN cable 31 Signal Line 32, 33 Power line 4 Commercial power supply 5 human body P1, P2, P3 Operation Panel S, S1, S2, S3 touch sensors S01 Board S02 Covering material S03 GND electrode S111 Electrode pattern S112, S12 GND pattern S111a, S111b Free end S111c connection part S111d Teeth S111e Tooth root area U Upper controller

Claims

1. In a self-capacitance detection touch sensor driven by an isolated power supply, The touch sensor has a touch area that a user should touch in one operation to realize a desired function, and the touch area includes: An electrode pattern formed by partitioning a part of the touch area; a GND pattern formed in a remaining area partitioning the touch area and spaced apart from the electrode pattern and electrically insulated from the electrode pattern; When the user touches the touch area, the GND pattern is capacitively coupled to the user, thereby matching the GND potential between the electrostatic capacitance on the user side and the parasitic capacitance on the touch sensor side. Touch sensor.

2. The touch sensor according to claim 1 , wherein the electrode pattern is formed in a C-shape or a U-shape.

3. The touch sensor according to claim 1 , wherein the electrode pattern is formed in a comb shape.

4. The touch sensor according to any one of claims 1 to 3, which is used in an operation panel of an air conditioning or lighting device.

5. The touch sensor of claim 4 used as a wall switch.

6. An air conditioning or lighting device using the touch sensor according to claim 5.

7. 7. The air conditioning or lighting equipment according to claim 6, wherein the insulated power supply is provided in a host controller, and the operation panel includes a non-insulated power supply.

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