JPS6266524A - Input unit for equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an input device for equipment using a capacitance method used in various equipment.

Conventional technology Conventionally, input devices using a capacitive method as a touch switch use a dielectric material such as tempered glass for the input part, so it is easy to realize a structure that prevents the intrusion of dust and water droplets. is possible, and is increasingly being used to improve reliability.

Hereinafter, a conventional input device using a capacitance method will be explained with reference to the drawings.

In FIG. 4, 1 is a flat panel made of a dielectric material such as tempered glass, 2 is a drive electrode, 21 is a drive signal line connected to the drive electrode 2, 3 is a detection electrode, and 31 is connected to the detection electrode 3. and 4 is a flexible printed circuit board. The drive electrode 2 and the detection electrode 3 are approximately parallel to each other, and the drive signal line 21. Detection electrode 3. A plurality of pairs of detection signal lines 31 are formed on the flexible printed circuit board 4, and the flexible printed circuit board 4 is provided on the back surface of the flat panel 1. Reference numeral 5 denotes a power source that generates an alternating current or pulse-like voltage, and is connected to the drive electrode 2 via a drive signal line 21.

Reference numeral 6 denotes a detection section composed of a comparator, etc., which compares the signal level via each detection signal line 31 with a reference potential "RXF" and outputs the result. Reference numeral 7 indicates a detection section 6.
This is a control unit that includes a microcomputer, etc., which performs predetermined control such as turning on and off a switch based on the output signal of the controller. Reference numeral 8 denotes a touch electrode constructed by depositing a conductive material such as tin oxide on the surface of a flat panel facing the driving electrode 2 and the sensing electrode 3, and the user can touch this touch electrode 8 with his or her finger. become.

FIG. 5 is a sectional view of a pair of drive electrodes 2 and detection electrodes 3 of a conventional example. Here, co is the capacitance of the human body, C1 is the capacitance 1 between the driving electrode 2 and the touch electrode 8, C2 is the capacitance between the sensing electrode 3 and the touch electrode 8, and C is the flat panel panel 1.
C4 is the capacitance between the drive electrode 2 and the detection electrode 3 via the paste material (for example, polyester resin) of the flexible printed circuit board 4.

The operation of the input device configured as above will be explained. Considering the case where the user does not touch the touch electrode 8, the current flowing at this time is the current flowing through '1+'2 which is connected in series via the touch electrode 8, the current flowing through C5, and the current flowing through C4. The potential v1 determined thereby is input to the detection section 6 via the detection signal line 31. On the other hand, when the user touches the touch electrode 8, a current flows to the ground via the capacitance co of the human body with respect to the ground.
The potential v2 determined by this is input to the detection unit via the detection signal line 31, and if the reference potential “RXF” input to the detection unit 6 is set between vl and vl, the touch electrode It is possible to detect the user's settings via the sensor 8, and a predetermined control is performed by inputting a signal corresponding to the user's settings from the detection unit 6 to the control unit.

Problems to be Solved by the Invention As described above, in order to detect the presence or absence of touch on the touch electrode 8 by the user, it is necessary to set the reference potential "R" in the detection section 6.
IF is the potential v1 before the user touches the touch electrode 8
Normally, this type of input device has at least two voltage levels, such as on and off.
0, but more than 7 touch electrodes are required.
When multiple pairs of drive electrodes 2 and detection electrodes 3 and drive signal lines 21 and detection signal lines 31 connected to them are provided on the brake/blunt board 4, one pair of drive electrodes and one to one pair of drive electrodes and one to one pair of detection electrodes are provided. The potential v1 before the user touches the touch electrode 8 and the potential v2 when the user touches the touch electrode 8 differ depending on each electrode pair due to the influence of stray capacitance between each electrode pair or between each signal line. Therefore, for each electrode pair (two reference potentials vitx
If y is set, there is a risk that the solved problem will be 1〒) 1-core configuration or sloppy. Shitaka-・11 (11-East what 11
Like i, rj rabbit moving electrode 2 and sensing electrode 3 (7) child 1-
By changing the 1st bond and adjusting the gap by 6 degrees, each evening, the distance between the driving U1 electrode 2 and the sensing electrode 3 is small. Change the amount 1. ・Chi electrode 8
By shifting the electric potential when not touching the touch electrode 8 and the electric potential v2 when touching the touch electrode 8, the electric potential v1 of the common part is changed.
A reference potential V□2 was set between the potential V2 and the potential V2. In this method, the capacitance is changed by changing the area of the driving electrode 2 and the sensing electrode 3 or adjusting the gap between them, but the area of the input panel is limited, and multiple input keys are arranged on a flat plate. When provided in the shaped panel 1, the area size of the drive electrode 2° and the detection electrode 3 is limited, and there is a risk that there is no space for routing the wiring (pattern) of the drive signal line 21 and the detection signal line 31. .

In addition, by changing the capacitance, the stray capacitance to adjacent electrodes (drive electrode and sensing electrode) increases or decreases, making the design pattern complicated and making it difficult to set a common reference potential vRIEF for each input key. I'm afraid it will become difficult...-1.

The present invention is: '7) J: Eliminates the problems of the conventional eel,
The present invention provides an input device for equipment with improved usability and reliability.

Means for resolving the problem (IW) In order to solve the above problem, the present invention provides a drive electrode portion consisting of a drive electrode and a drive signal line connected thereto, a sensing electrode and a sensing signal line connected thereto. A plurality of pairs of sensing electrode sections are formed on a flexible printed circuit board, a notch is provided in the flexible printed circuit board between the driving electrode section and the sensing electrode section, and the flexible printed circuit board is provided on the back surface of a flat panel made of a dielectric material. Depending on the configuration,
Configure the device's input device.

Effect By having the above-mentioned configuration, it is possible to adjust the stray capacitance between a predetermined drive electrode section and a detection electrode section, with almost no effect on the adjacent electrode section (drive electrode section or detection electrode section). The input potential v1 to the detection part when the user does not touch (no touch) the touch electrode corresponding to the pair of drive electrode part and detection electrode part, and the input potential to the detection part when the user touches (touch) the touch electrode. It becomes possible to shift the input potential v2 throughout. As a result, the drive electrode part and the detection electrode part can have the same area, etc., and therefore the input potential difference (L+'/2) of each electrode part becomes almost the same.

In addition, the input potential v
Since it is possible to shift 71 and vl, it is possible to set 71 and vl almost universally even for a plurality of inputs.

Therefore, even in the case of an input device having a plurality of input keys, the design becomes easy, and the user's settings can be set reliably, thereby achieving usability and reliability.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a flat panel of an input device according to an embodiment of the present invention, viewed from the back side. In Fig. 1, 1 is a flat panel made of dielectric material such as tempered glass;
b is a plurality of drive electrodes, 21 is a drive signal line connected to the drive electrode 2b, and 3b is a plurality of detection electrodes that detect the output from the drive electrode 2b. 31 is a sensing electrode wire connected to each sensing electrode. 4b is a flexible printed circuit board, drive electrode 2b, and detection electrode 3b.

, drive signal line 21. The detection signal line 31 is constructed on a flexible printed circuit board 4b, and the flexible printed circuit board 4b is firmly fixed to the back surface of the flat panel 1.

Reference numeral 9 denotes a cutout portion provided at a predetermined portion between the drive electrode 2b and the detection electrode 3b. It is formed by cutting out part or all of the wood part. That is, the cutout portion 9 forms a recess or a through hole in the flexible substrate 4b. Reference numeral 6 indicates a power source, 6 a detection section, 2 a control section, and 8 a touch electrode, which are the same as the configuration shown in FIG. 4 except for the main parts.

FIG. 2 is a sectional view of an electrode having a notch 9 in the same embodiment. Go is the capacitance of the human body, C1 is the capacitance between the drive electrode 2b and the touch electrode 8, and C2 is the detection electrode 3
b and the capacitance between the touch electrode 6, C3 is the flat panel 1
The capacitance between the driving electrode 2b and the sensing electrode 3b via C
4 is a notch 9 or a flexible printed circuit board 4b
This is the capacitance between the driving electrode 2b and the sensing electrode 3b via the base material portion.

FIG. 3 shows the input potential of the detection unit 6 after adjustment in FIGS. It corresponds to the input key. Here, vl is an input potential to the detection unit 6 when the user does not touch it, vl is an input potential to the detection unit 6 when the user touches it, and VRIF is a common reference potential for each input potential. In addition, the operation of the input device configured as above is explained with the ○ mark and the X mark as vl r vl r· mark without the notch portion 9, and with the mu mark as above. First, considering the case where the user does not touch the touch electrode 8, the current that flows at this time is the current that flows through C2, which is connected in series via the touch electrode 8, the current that flows through C3, and the current that flows through 04. It becomes peace. In other words, a current determined by the synthesis seen from the input section of the detection section e flows into the detection section 6 via the detection signal line 31, and a potential v1 is generated at the input of the detection section 6 due to the internal impedance of the detection section 6.

On the other hand, considering the case where the user touches the touch electrode 8,
At this time, the current flowing into the sensing electrode 3b is divided into a portion of the current flowing into C1 via C2 and a portion of the current flowing into C1 via C2, since most of the current flowing into C1 flows into the ground via the capacitance co of the human body with respect to the ground. This is the sum of the current flowing through 04 and the current flowing through 04. In other words, the combined capacitance C seen from the input section of the detection section 6 is: A current determined by this flows into the detection section 6 via the detection signal line, and a potential v; is applied to the input of the detection section 6 due to the internal impedance of the detection section 6. arise.

Combined capacity 0. Comparing C, when touching the touch electrode 8, the first item 03. The second item C2 remains unchanged. In other words, the difference in potential at the input of the detection unit 6 when the touch electrode 8 is not touched and when it is touched is due to a change in the third item of the combined capacitances c and c', since the internal impedance of the detection unit 6 does not change. You can say that. Here, if the areas of the plurality of driving electrodes 2b are made equal, the areas of the plurality of sensing electrodes 3b are also made equal, and the same user touches the touch electrode 8, then the combined capacitance c, co of c, C1 , C2 does not change, so in the end, the first item C3 and the second item C4 in the combined capacitance C, C when the touch electrode 8 is not touched and when it is touched are as follows.
This is a capacitance that exists regardless of the touch on the touch electrode 8, and is always connected from the drive electrode 2b to the detection electrode 3 via C5 and C:
A leakage current flows through b.

Therefore, the input potential of the detection unit 6 is Cs of the combined capacitances C and C.
It is shifted by the potential determined by +Ca, and the input potential of the detection unit 6 when the user touches or does not touch is determined.

Generally, capacitance is proportional to the permittivity of the dielectric material between the electrodes and inversely proportional to the distance therebetween. Therefore, by providing a notch 9 by cutting out part or all of the base material (polyester etc.) of the flexible printed circuit board 4 between the drive electrode 2b and the detection electrode 3b, it is possible to increase the dielectric constant between the drive electrode 2b and the detection electrode 3b. By making the distance between the notches 9 between the electrodes low, the capacitance C between the driving electrode 2b and the sensing electrode 3b through the base material of the flexible printed circuit board can be reduced.
4 can be changed.

As described above, according to this embodiment, a plurality of pairs of drive electrodes 2b and detection electrodes 3b are configured on a flexible printed circuit board,
A notch 9 is provided in the flexible printed circuit board 4b between a predetermined drive electrode 2b and a detection electrode 3b, and by adjusting the capacitance 1tc4 between the drive electrode 2b and the detection electrode 3b, a predetermined input potential to the detection section 6 can be set. can be shifted to match the input potential levels of all input signals input to the detection unit 6 (Fig. 3), and as a result, the input potential at the detection unit 6 when the user touches the touch electrode and ＼It becomes possible to set a common reference potential VRXF for all input potentials between the input potentials in the detection unit 6 when not touched, and by comparing the input potential and the reference potential,
User settings can be detected.

In addition, there is no restriction on the area of the drive electrode 2b and the detection electrode 3b, and the design of the shape of the drive electrode 2b and the detection electrode 3b becomes simple, and the user's settings can be reliably accepted with a simple structure. This will improve usability and reliability.

In this embodiment, the shape of the drive electrode 2b and the detection electrode 3b is rectangular, but the shape may be approximately E-shaped or approximately H-shaped.The point is that the drive electrode 2b and the detection electrode 3b are electrically It suffices if it is insulated and constructed on the flexible printed circuit board 4b.

Further, although the cutout portion 9 is provided between the drive electrode 2b and the detection electrode 3b, the same effect can be obtained even if the cutout portion is provided between the drive signal line 21 and the detection signal line 31. In short,
It is only necessary to be able to adjust the capacitance between the conductive part connected to the power supply configured on the flexible printed circuit board 4b and the predetermined conductive part connected to the detection part 6. Further, in this embodiment, the touch electrode 8 is provided on the surface of the flat panel 10, but if the touch electrode 8 is not provided, the touch electrode 8 is provided separately so that the user's finger can perform the same role as the touch electrode 8. The same effect can be obtained without it.

Effects of the Invention As described above, the present invention has a plurality of pairs of drive electrode parts each consisting of a drive electrode and a drive signal line connected thereto, and a plurality of pairs of detection electrode parts each consisting of a detection electrode and a detection signal line connected thereto, on a flexible substrate. By providing a notch in the flexible substrate between the drive electrode part and the sensing electrode part, and by providing the 7 lexiple printed circuit board on the back side of the flat panel made of dielectric material, the drive electrode part can be connected to the drive electrode part at the notch part. It is now possible to adjust the capacitance of the sensing electrode part, and as a result, the input potential when the user does not touch a predetermined position on the flat panel surface (no touch) and when the user touches it (touch)
Since the input potentials of the input terminals can be almost matched, a common reference potential for determining user settings can be set for all the plurality of input potentials.

As a result, the user's settings from all flat panels can be reliably detected, thereby improving usability and reliability, which has significant effects.

[Brief explanation of drawings]

FIG. 1 is a plan view of an input device according to an embodiment of the present invention, seen from the back side of a flat panel, FIG. 2 is a sectional view of an input device using the same flat panel, and FIG. 3 is a plan view of the same flat panel. FIG. 4 is a plan view of the conventional input device as seen from the back side of the flat panel, and FIG. 6 is a sectional view of the conventional input device. 1...Flat panel, 2b...Drive electrode, 3b...Detection electrode, 4b...Flexible printed circuit board, 6...Power supply , 6...
...detection section. Name of agent: Patent attorney Toshio Nakao and 1 other person1

1-Ichiko Rokubushi ha 0 Nell 2h--・Kanht food 5 list Iso-1 to school wholesale 1'7-Printing 1'lf-Mh plan 57・
-Know ・Figure 2C. Figure 3

Claims (3)

[Claims] (1) A plurality of pairs of a drive electrode section consisting of a drive electrode and a drive signal line connected thereto, and a detection electrode section consisting of a detection electrode and a detection signal line connected thereto are configured on a flexible printed circuit board, and the drive electrode section and a notch portion for adjusting the capacitance between the electrode portions is provided in a flexible printed circuit board between the sensing electrode portion and the sensing electrode portion, and the flexible printed circuit board is provided on the back side of a flat panel made of a dielectric material. . (2) The input device for an apparatus according to claim 1, wherein the notch is provided in the flexible printed circuit board between the drive electrode and the detection electrode. (3) The input device for a device according to claim 1, wherein the cutout portion is provided on the flexible printed circuit board between the drive signal line and the detection signal line.