JP2006128020A - Electrostatic capacity type switching arrangement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem about maintenance of a sense of beauty, security, and privacy without deteriorating detection sensitivity. <P>SOLUTION: A detection electrode 2 composed of a transparent electrode to detect approach of a human body is arranged on the rear face of a design plate 1, and this detection electrode 2 is opposed to a backlight 6. A mask plate 3 for display in which a light transmission pattern 3a is formed is installed on the backlight 6. A second light source 7 is arranged on the rear side of the backlight 6. The mask plate 3 for the display, the backlight 6, or the second light source 7 cannot be recognized visually in a normal state because they are covered by the design plate 1. When a finger of an operator approaches the detection electrode 2, the backlight 6 is switched on and the light transmission pattern 3a looms up on a surface 1a of the design plate 1. If the finger is contacted with that part, the second light source 7 is lighted on, and because brightness and color or the like of the light transmission pattern 3a which has loomed up on the design plate 1 are changed, it is confirmed by this that the switch is turned to be ON state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a capacitive switch device used for home appliances, industrial equipment, transportation equipment, buildings, and the like.

Conventionally, as an electrostatic capacitance type switch for detecting a change in electrostatic capacitance, for example, one disclosed in Patent Document 1 is known. The device disclosed in Patent Document 1 is provided with a transparent electrode for capacitance detection and a display element under a transparent protective film, and the capacitance at the transparent electrode is detected by detection means, and based on the detection result. The control means drives the display element. Further, this Patent Document 1 also discloses that a mask is provided on the display surface of the display element to display characters and pictures. As a result, not only a touch switch without a mechanical drive part is realized, but also the operator can be notified by a display function that the switch has been turned on.
Japanese Patent Laid-Open No. 5-29879, paragraphs 0012-0013, 0019, FIG.

  In the conventional capacitive switch described above, the position of the switch can be visually recognized from the outside only by the presence of the transparent electrode and the protective sheet between the switch surface and the display means. In other words, from the viewpoint of operation, it is a premise that the position of the switch is clearly shown, and it can be said that this is technical common sense.

  On the other hand, however, there is a demand to make the position of the switch invisible from the outside, for example, due to design reasons or security and privacy issues. In such applications, the prior art cannot be applied as it is.

  The present invention has been made in view of these points, and an object of the present invention is to provide a capacitance type switch that can maintain aesthetics and solve security and privacy problems without any loss of operability. And

  The capacitance type switch device according to the present invention detects a capacitance corresponding to a detection electrode, an illumination means arranged in the vicinity of the detection electrode, and a capacitance between the detection electrode and the ground. A capacitance detection circuit that outputs a value; a control unit that controls the illumination unit based on a detection value output from the capacitance detection circuit; and the illumination unit is externally covered, and the illumination unit is not lit. Sometimes the illumination means is made invisible from the outside, and when the illumination means is turned on, the illumination means has a covering material having a light transmittance that floats on the external surface, and the detection electrode is transparent It is formed by an electrode, and is arranged between the covering material and the illuminating means or on the surface of the covering material opposite to the illuminating means.

  According to the present invention, the illuminating means is covered from the outside with the covering material, the covering material makes the illuminating means invisible from the outside when the illuminating means is not lit, and the light from the illuminating means is externally exposed when the illuminating means is lit. It has a light transmittance that floats on the surface of the surface, so that the presence of the switch can be hidden from the outside, and the detection electrode is formed of a transparent electrode, between the covering material and the illumination means or between the covering material Since it is arrange | positioned on the surface on the opposite side to an illumination means, the distance from the surface of a coating | covering material is near, and detection sensitivity does not fall.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an exploded perspective view showing the configuration of the capacitive switch device according to the first embodiment of the present invention.

  In this switch device, a rectangular detection electrode 2 made of a transparent electrode for detecting the approach of a human body is arranged on the back side of a design plate 1 as a covering material, and the back side of the design plate 1 is interposed via the detection electrode 2. A display mask plate 3, a backlight 6 including a backlight light guide plate 4 and a first light source 5, and a second light source 7 are sequentially arranged. Here, the design plate 1 is formed of a material such as a light-transmitting resin or glass, and, for example, a desired pattern or color sheet is pasted on the surface 1a of the colorless and transparent plate. %, For example, adjusted to a light transmittance of 10 to 50%. The display mask plate 3 is formed by forming a predetermined light transmission pattern 3a such as predetermined characters, symbols and figures in order to indicate the type and position of the switch, and masking the other portions. It is sometimes provided to float the light transmission pattern 3a on the surface 1a of the design board 1.

  FIG. 2 is a circuit diagram showing a circuit configuration of the switch device.

  The detection electrode 2 is connected to the capacitance detection circuit 11. The capacitance detection circuit 11 outputs a detection value corresponding to the capacitance between the detection electrode 2 and the ground. The detection circuit 11 includes an oscillation circuit, for example, and generates a signal whose oscillation frequency or duty ratio changes according to the capacitance Cx generated by the detection electrode 2. The detection value output from the detection circuit 11 is input to the determination circuit 12 constituting the control means. The determination circuit 12 includes two comparators 121 and 122. The comparator 121 inputs the detection value from the capacitance detection circuit 11 to one input terminal, and inputs the first determination voltage generated by the determination voltage generation circuit 123 to the other input terminal. A first detection signal is output when the determination voltage exceeds one. The comparator 122 inputs the detection value from the capacitance detection circuit 11 to one input terminal, and inputs the second determination voltage generated by the determination voltage generation circuit 124 to the other input terminal. 2 The second detection signal is output when the determination voltage is exceeded. Here, the second determination voltage is larger than the first determination voltage, and is set to a voltage that exceeds when the human body almost touches the design plate 1. The light source driving circuit 13 drives the first light source 5 composed of an LED or the like by the first detection signal. Further, the light source driving circuit 14 drives the second light source 7 composed of an LED or the like by the second detection signal.

  Next, the operation of the switch device according to this embodiment configured as described above will be described.

  When a human body, for example, a finger, approaches the detection electrode 2, the grounding capacitance of the detection electrode 2 through the human body changes, and as a result, the detection value output from the capacitance detection circuit 11 increases as shown in FIG. . When the detection value from the capacitance detection circuit 11 exceeds the first determination voltage, the determination circuit 12 drives the light driving circuit 13 to turn on the first light source 5 for backlight. When the backlight 6 is turned on in this way, the light passes through the light transmission pattern 3a of the display mask plate 3 and the transparent detection electrode 2 and irradiates the back surface of the design plate 1, so that the surface of the design plate 1 In 1a, the light transmission pattern 3a appears to float up.

  When the operator confirms this and brings his / her finger into contact with the portion where the light transmission pattern 3a of the design board 1 is raised, the detection value from the capacitance detection circuit 11 exceeds the second determination voltage. 12 drives the light driving circuit 14 to turn on the second light source 7 and outputs a switch ON signal to a circuit (not shown). When the second light source 7 is turned on, the brightness, color, and the like of the light transmission pattern 3a floating on the design plate 1 change, so that the operator can be notified that the switch operation has become effective.

  FIG. 4 is a perspective view showing a configuration of a capacitive switch device according to a second embodiment of the present invention, and FIG. 5 is a sectional view of the same.

  This embodiment is an example in which one backlight is shared for a plurality of different types of switches.

  The design component 21 as a covering material forming a part of the device is subjected to design processing such as a pattern and a color according to the purpose on the surface 21a. For example, if a transparent member obtained by transferring a woodgrain print is used, it becomes a woodgrain switch, and if a member having a magic mirror function is used, a metallic switch can be realized. A groove 21 b is formed on the back surface of the design component 21. In addition, detection electrodes 24 made up of a plurality of transparent electrodes are formed along the groove 21b in the groove 21b, and a capacitive switch module 22 is mounted.

  The capacitive switch module 22 is configured as follows. That is, an integrated circuit component 25 in which a circuit such as a capacitance detection circuit is integrated is mounted on the substrate 23 extending along the groove 21b. A second light source 26 for operation display is attached. On the substrate 23, a backlight 27 and a display mask plate 28 are mounted in this order so as to cover the entire plurality of detection electrodes 24. The backlight 27 has a backlight reflecting sheet 30 attached to the surface of the backlight light guide plate 29 on the substrate 23 side, and a first light source 31 for backlight is attached to the side edge of the backlight light guide plate 29 as a backlight. It is mounted toward the light guide plate 29. The display mask plate 28 is formed by forming a light transmission pattern 28 a indicating the position of the switch at each detection electrode 24.

  FIG. 6 is a block diagram showing an electrical configuration of the capacitive switch device according to the present embodiment.

  In this embodiment, the capacitance detection circuit 11, the determination circuit 12, the light source driving circuit, and the second light source 26 described above are used as the switch circuits 41 and 42 corresponding to each detection electrode 24, and the plurality of switch circuits 41, 42 are used. By applying the first detection signal from 42 to the light source drive circuit 13 via the OR gate 15, the first light source 31 is turned on when any one of the plurality of switch circuits 41, 42 is turned on. It is what I did.

  In this apparatus, when an operator's finger approaches any one of the plurality of detection electrodes 24, the first light source 31 is turned on, and the light of the plurality of light transmission patterns 28a floats on the surface 21a of the design component 21. When the operator touches a desired switch portion with a finger from the floating pattern, the second detection signal from the determination circuit 12 corresponding to the detection electrode 24 in the vicinity of the portion is turned on. The two light sources 26 are turned on and the luminance changes. Thereby, it can be seen that the switch is turned on.

  Thus, according to the switch device of the present embodiment, the backlight 27 including the first light source 31 can be shared by a plurality of switches, so that the unit price and the number of assembly steps can be reduced, and the cost can be reduced. You can plan.

  Further, if each switch circuit 41, 42 is provided with setting means such as a switch circuit capable of setting the validity / invalidity of the function, the same switch module 22 can be used for a plurality of applications. Become.

  In addition, this invention is not limited to embodiment mentioned above. For example, FIG. 7 shows the simplest embodiment in which the illumination means is composed of one light source 8. In this embodiment, the light source 8 is turned on when the human body approaches the detection electrode 2 (first state), and when the human body further approaches the detection electrode 2 (for example, contact with the design plate 1), The lighting brightness changes or blinks (second state).

  The embodiment of FIG. 8 is an example in which the illumination means is constituted by two light sources, that is, the first light source 5 and the second light source 7 instead of the light source 8 of FIG. In this case, the light source 5 is turned on when the human body approaches the detection electrode 2, and the light source 7 is turned on when the human body approaches the detection electrode 2. If the emission colors of the two are changed, it becomes easier to confirm the operation.

  The embodiment of FIG. 9 is an example in which a backlight light guide plate 4 is provided between the design plate 1 of FIG. 8 and the light sources 5 and 7. According to this embodiment, the shape of the switch can be projected more clearly on the surface of the design plate 1.

  In the embodiment of FIG. 10, the first light source 5 is disposed on the side edge of the backlight light guide plate 4, and the display mask plate 3 is omitted from the embodiment of FIG.

  In this case, the design plate 1 can transmit uniform light.

  In the above embodiment, the lighting state is controlled to have different luminance and / or color as the first and second states by one or two light sources. However, the first and second states are other than this. Alternatively, one may be lit, the other blinked, one may be lit, and the other may be extinguished. In short, if the position of the switch can be confirmed in the first state and it can be confirmed that the switch is turned on in the second state, the effect of the present invention can be achieved.

  Moreover, in the above embodiment, although the detection electrode was arrange | positioned on the back surface of coating | covering materials, such as a design board, since a detection electrode is a transparent electrode, you may arrange | position to the surface side of a coating | covering material. In this case, since the distance to the object to be detected can be further shortened, there is an advantage that the detection sensitivity is further improved.

It is a disassembled perspective view which shows the structure of the electrostatic capacitance type switch apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the electric constitution of the apparatus. It is a graph which shows the relationship between the distance between the human body in the same apparatus and a detection electrode, and the detected value of an electrostatic capacitance detection circuit. It is the perspective view which notched a part which shows the structure of the electrostatic capacitance type switch apparatus which concerns on other embodiment of this invention. It is sectional drawing of the same apparatus. It is a block diagram which shows the electric constitution of the apparatus. It is a disassembled perspective view which shows other embodiment of this invention. It is a disassembled perspective view which shows other embodiment of this invention. It is a disassembled perspective view which shows other embodiment of this invention. It is a disassembled perspective view which shows other embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Design plate, 2, 24 ... Detection electrode, 3, 28 ... Display mask plate, 4 ... Back light guide plate, 5, 31 ... First light source, 6, 27 ... Back light, 7, 26 ... Second light source , 8 ... light source, 11 ... electrostatic capacity detection circuit, 12 ... determination circuit, 13, 14 ... light source drive circuit.

Claims (14)

A sensing electrode;
Illumination means disposed in the vicinity of the detection electrode;
A capacitance detection circuit that detects a capacitance between the detection electrode and the ground and outputs a detection value corresponding to the capacitance;
Control means for controlling the illumination means based on a detection value output from the capacitance detection circuit;
Light transmittance that covers the illumination means from the outside, makes the illumination means invisible from the outside when the illumination means is not lit, and causes light from the illumination means to float on the external surface when the illumination means is lit. And having a covering material
The detection electrode is formed of a transparent electrode, and is disposed between the covering material and the illuminating means or on the surface of the covering material opposite to the illuminating means. apparatus. The covering material is a plate-like body,
The capacitance switch device according to claim 1, wherein the detection electrode is formed on a back surface of the covering material. The covering material is a plate-like body,
The capacitance switch device according to claim 1, wherein the detection electrode is formed on a surface of the covering material. The control means includes
When the detection value output from the capacitance detection circuit exceeds a first threshold value, the illumination means is set to the first state, and the detection value is larger than the first threshold value. The electrostatic capacitance type switch device according to claim 1, wherein the illumination means is set to the second state when the threshold value of the capacitance is exceeded. One of the first and second states is a lighting state with the first luminance of the illumination means, and the other is a lighting state with a second luminance larger than the first luminance of the illumination means. The capacitance type switch device according to claim 4, wherein the capacitance type switch device is provided. The one of the first and second states is a lighting state by the first color of the illuminating means, and the other is a lighting state by the second color of the illuminating means. Capacitive switch device. The capacitance type switch device according to claim 4, wherein one of the first and second states is a lighting state of the illumination means, and the other is a blinking state of the illumination means. 5. The capacitance type switch device according to claim 4, wherein one of the first and second states is a lighting state of the illumination means, and the other is a light extinction state of the illumination means. The illumination means includes a first light source and a second light source,
The first light source is turned on when a detection value output from the capacitance detection circuit exceeds a first threshold value,
The capacitance type switch device according to claim 4, wherein the second light source is turned on when a detection value output from the capacitance detection circuit exceeds a second threshold value.   2. The capacitive switch device according to claim 1, wherein the illumination means includes a light source and a light guide plate that guides light from the light source to the detection electrode.   The capacitive switch according to claim 9, further comprising a backlight light guide plate that irradiates light from the first light source as a backlight to the back surface of the covering material through the detection electrode. apparatus.   A mask material interposed between the illuminating means and the covering material to partially mask the light from the illuminating means so as to float a predetermined pattern on the surface of the covering material; The capacitance type switch device according to claim 1. The detection electrode, the capacitance detection circuit, the determination circuit, and the second light source constitute a switch circuit,
A plurality of the switch circuits are provided,
The first light source is provided in common to the plurality of switch circuits, and is turned on when the detection value of any one switch circuit exceeds the first threshold value,
The capacitance type switch device according to claim 9, wherein only the second light source provided in a switch circuit whose detected value exceeds the second threshold value is turned on. 14. The capacitance type switch device according to claim 13, wherein each of the switch circuits has setting means capable of setting whether the function is valid / invalid.

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