JPH061651B2 - Transparent flat switch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transparent flat switch that opens and closes contacts by displacing a sheet by touching a pen, and particularly performs a precise coordinate detection operation by eliminating a dead zone due to a spacer. Regarding things.

[Conventional technology]

The pressed position coordinate detection method can be classified into analog, digital, and digital analog, but since the basic configuration and operation are the same, analog will be described here as an example.

As a conventional analog type transparent flat switch of this kind in which the electrodes are opened and closed by utilizing the displacement of the elastic insulating sheet in the thickness direction, for example, one shown in FIG. 14 has been proposed. ing. This is described in Chapter 7 Transparent Taichi Panel of "Points of Development, Design and Application of Input Device" issued by Japan Industrial Technology Center, and Figs. 8 to 14 are diagrams for explaining each configuration. is there. Hereinafter, the conventional transparent flat switch will be described with reference to FIGS.
It will be described with reference to the drawings. Incidentally, these FIG. 8 to FIG.
Although FIG. 4 is originally described for finger touch, it can be used for pen touch, and the fact is that it is practically not used for pen touch. Therefore, the description will be given here by replacing it with the one for pen touch.

In each figure, 5 indicates a movable electrode sheet. This is one in which an electrode layer 2 made of a transparent conductive material is added to the inner surface of a transparent insulating sheet 1 having elasticity, and a narrow width which is an electrode for signal extraction is provided on the electrode layer 2. Movable leads 3 and 4 are provided. Reference numeral 10 indicates a fixed electrode sheet. This is one in which an electrode layer 7 made of a transparent conductive material is added to the inner surface of a transparent insulating sheet 6, and thin fixed leads 8 and 9 are provided on the electrode layer 7 (eleventh eleventh). (See Fig. 12). The movable leads 3 and 4 and the fixed leads 8 and 9 are provided at both ends or upper and lower ends of the insulating sheets 1 and 6, respectively.
When stacking, the movable leads 3 and 4 and the fixed leads 8 and 9
Are provided so that their positions are displaced by 90 °. On the electrode layer 7, a plurality of spacers 11 are provided as protrusion insulating dots. The movable electrode sheet 5 and the fixed electrode sheet 10 are laminated via the spacer 11 as shown in FIG. 8 to form a transparent flat switch.

Next, the operation of the analog transparent flat switch configured as described above will be described.

When a pressure is applied from the insulating sheet 1 side of the movable electrode sheet 5 as shown in FIG. 13 using a pen P such as a ballpoint pen, the movable electrode sheet 5 is pushed downward, and accordingly the electrode layer 2 also. Bends downward through the spacer 11. As a result, as shown in FIG. 13, the electrode layer 2 and the electrode layer 7 of the fixed electrode sheet 10 are brought into contact with each other, and the switch is brought into conduction.

When the pressure of the pen P is reduced, the movable electrode sheet 5 starts to return to its original state due to the elasticity of the insulating sheet 1, the electrode layer 2 is separated from the electrode layer 7, and the switch becomes non-conductive. . As the electrode layer 2 and the electrode layer 7 are brought into contact with each other and separated from each other, the switch is turned on and off, and the coordinates are input by operating the switch with the pen P.

By the way, since the resistance distributions of the electrode layers 2 and 7 are uniform, the coordinates are detected by connecting a switch to a constant current source as shown in FIG.
And a current ratio (X coordinate) flowing into the movable lead 4 and a current ratio (Y coordinate) flowing out from the fixed lead 8 and the fixed lead 9 of the fixed electrode sheet 10 are obtained, and the coordinates are determined by A / D conversion. To be done.

In other words, the X and Y coordinates are obtained from equations (1) and (2), The total current equation is shown by the relation of the equation (3), and I = i ₁ + i ₂ = i ₃ + i (3) Is.

Also, the coordinates can be similarly obtained by connecting a switch to the constant voltage source.

[Problems to be solved by the invention]

However, in the conventional analog type transparent flat switch as described above, since the spacer 11 made of an insulating material is interposed between the electrode layers 2 and 7, the shaded area in FIG. Thus, the dead zone E in which the electrode layer 2 and the electrode layer 7 cannot be dissolved due to the height of the spacer 11 itself is generated. The dead band E divided by the switch mounting density (the number of bits of the A / D converter) is
It is the number of switches that do not actually work. That is, if the switch mounting density is increased even if the dead band E is the same,
The higher this increases the number of non-operational switches. As a countermeasure against this, it is conceivable to reduce the shape of the spacer 11 to narrow the dead zone E, but this also causes the adhesion of the spacer 11 itself to the base material and the manufacturing problem. Even if the shape is made small, there is a dead zone E, so that there is a problem that it is not a fundamental solution.

The present invention has been made to solve the above problems, and an object thereof is to obtain a highly reliable transparent flat switch without the dead zone E.

[Means for solving problems]

The transparent flat switch of the present invention comprises a movable electrode sheet 13 formed by coating an electrode layer 2a made of a conductive material on the inner surface of an insulating sheet 1, and an electrode layer 7a made of a conductive material on the inner surface of an insulating sheet 6. Fixed electrode sheet 1 formed by coating
5 and at least one spacer layer interposed between the electrode layers 2a and 7a so as to make mechanical surface contact with the inner surfaces of the electrode layers 2a and 7a. It was formed by a coating film of transparent conductive paint.

[Action]

The electrode layers 2a and 7a are mechanically in contact with each other via the spacer layer, but the switch is in an OFF state because there is a large contact resistance electrically, and the movable electrode sheet 13 is pen-shaped. When the external stress is applied at, the contact resistance of the spacer layer decreases, and the switch is turned on to detect the coordinates. Further, since the spacer layer is provided over the entire surface between the electrode layers 2a and 7a, no protruding spacer is interposed between the electrode sheets 13 and 15, and the dead zone E is provided only at a specific portion when the coordinate is input. Therefore, accurate coordinates can be input.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. The same parts as those of the conventional example shown in FIGS. 8 to 14 are designated by the same reference numerals, and the description thereof will be omitted.

In each drawing, 13 is a movable electrode sheet of the present invention,
This is an electrode layer 2a composed of a coating layer coated with a conductive paint.
A spacer layer 12 made of a coating layer coated with a conductive coating is further provided on the top. Reference numeral 15 is a fixed electrode sheet of the present invention, in which a spacer 14 composed of a coating layer coated with a conductive coating is further provided on an electrode layer 7a composed of a coating coated with a conductive coating. The spacer layer 1
The resistances of 2 and 14 are reduced by receiving pressure.
The above-mentioned electrode sheets 13 and 15 are formed into the spacer layers 12 and 14
Are stacked through. That is, the spacer layers 12 and 14 on the inner surfaces of the electrode layers 2a and 7a are in mechanical surface contact, and the electrode layers 2a and 7a and the spacer layers 12 and 14 are all in mechanical surface contact. Thus, the transparent flat switch of the present invention is constructed. In addition, the both electrode layers 2
Since a and 7a and the spacer layers 12 and 14 are both made of a transparent conductive paint having excellent scratch resistance,
The reliability as a switch is also high.

Next, the operation will be described.

When inputting the coordinates, the insulating sheet 1 is pressed with the pen P or the like. As a result, the contact resistance between the electrode sheets 13 and 15 gradually decreases as shown in FIG. 7, and finally reaches a stable value of 2 to 3 kΩ. The conduction state of the switch can be defined by detecting this stable inter-electrode resistance. The change in the resistance between the electrode sheets 13 and 15 is due to the change in the contact resistance (which accounts for most of the resistance between the electrode sheets 13 and 15) generated by providing the spacer layers 12 and 14, and the switch has an external stress. The resistance between the electrode sheets 13 and 15 is changed by.
That is, by providing the spacer layers 12 and 14, the pressure sensitive characteristics are provided between the electrode sheets 13 and 15. Further, when the external stress due to the pen or the like decreases, the spacer layers 12 and 14 start to restore, and the electrode sheets 13 and 15
Resistance gradually increases, and finally the original number of 10 kΩ
It becomes a specific conduction state of.

Although the analog transparent flat switch has been described in the above embodiment, a digital or digital analog type switch may be used. Further, the same effect can be obtained by providing the spacer layer on only one of the electrodes.

〔The invention's effect〕

As described above, according to the present invention, by providing the electrode layers 2a and 7a made of a coating film of a transparent conductive material and the spacer layer, a pressure sensitive characteristic is generated between the electrode sheets 13 and 15. Then, the ON / OFF state of the switch is defined by the magnitude of the electrical contact resistance of the spacer layer thereby, but the two electrode sheets 13, 15 are in mechanical contact with each other by the spacer layer, and the electrode sheet 13, Since the dead zone disappears between 15 and continuous accurate coordinate data can be output, it can be used for drawing input, and a transparent flat switch with high reliability can be obtained even if the switch density is increased. You can In addition, since the electrode layers 2a and 7a and the spacer layer are both printed by using a transparent conductive paint having excellent scratch resistance, they are not scratched during handling and assembly work, and the yield is improved. It is possible to obtain highly reliable products. Further, since various operations are performed only by a series of printing steps, there is an effect that manufacturing cost can be reduced.

[Brief description of drawings]

1 to 1 show one embodiment of the transparent flat switch of the present invention. FIG. 1 is a plan view of a movable electrode sheet, FIG. 2 is a sectional view taken along the line II of FIG. 1, and FIG. A plan view of the fixed electrode sheet, FIG. 4 is a sectional view taken along line II-II of FIG. 3, FIG. 5 is a configuration diagram of a transparent flat switch, FIG. 6 is an equivalent circuit diagram of a transparent flat switch, and FIG. 7 is a transparent flat switch. A characteristic curve diagram showing the change of contact resistance with respect to the applied pressure of the switch, FIGS. 8 to 14 show an example of a conventional transparent flat switch, FIG. 8 is a configuration diagram of the transparent flat switch, and FIG. 9 is movable. A plan view of the electrode sheet, FIG. 10 is II of FIG.
I-III sectional view, FIG. 11 is a plan view of the fixed electrode sheet, FIG. 12 is a sectional view taken along line IV-IV of FIG. 11, FIG. 13 is an operation state diagram, and FIG. 14 is a diagram when connected to a constant power source. It is explanatory drawing which showed the equivalent circuit. 1, 6 ... Insulating sheet, 2a, 7a ... Electrode layer,
12, 14 ... Spacer layer, 13 ... Movable electrode sheet, 15 ... Fixed electrode sheet.

Claims (2)

[Claims] 1. A movable electrode sheet 13 formed by depositing an electrode layer 2a made of a conductive material on the inner surface of an insulating sheet 1, and an electrode layer 7a made of a conductive material on the inner surface of an insulating sheet 6. The fixed electrode sheet 15 and the electrode layer 2a,
Both electrode layers 2a, so as to make mechanical surface contact with each inner surface of 7a,
A transparent flat switch, comprising at least one spacer layer interposed between 7a, wherein the electrode layers 2a, 7a and the spacer layer are formed by a coating film of a transparent conductive paint. 2. A patent characterized in that a spacer layer made of a coating film of a transparent conductive paint is provided on each inner surface of each electrode layer 2a, 7a, and each spacer layer 12, 14 is mechanically brought into surface contact with each other. The transparent flat switch according to claim 1.