JPS62147520A - Input device - Google Patents

Abstract

PURPOSE:To widen an effective range where the position of a push point can be detected with high accuracy by reducing the surface resistance produced at a part where a pair of parallel electrode terminals cross with each other on a substrate to smaller than the surface resistance of the parallel electrode terminals. CONSTITUTION:An electrode 2 is formed on a substrate 4 together with an electrode terminal 1 having the surface resistance smaller than that of the electrode 2. While an electrode 6 is formed on another substrate 7. Both substrates 4 and 7 are bond with each other via a spacer 8 and plural convex spacers 9 so that both electrodes 2 and 6 are set opposite to each other. Thus an input device is obtained. Then the 2nd electrode terminal 5 is provided at a point where both terminals 1 in the X and Y directions cross each other. The surface resistance of the element 5 is reduced to smaller than that of the terminal 1. Thus the potential is fixed on both lines A and B and therefore a pushed position can be detected with high accuracy.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a high precision input device.

[Conventional technology]

Conventional devices of this type include two sets of parallel strips each having a predetermined interval on a substrate having electrodes having a constant resistance value, as shown in JP-A-59-13227 and JP-A-59-132237. a first panel with electrode terminals arranged perpendicular to each other; and a second panel that has a sheet resistance that is the same as or different from that of the first panel and that is easily deformed in the direction perpendicular to the surface by applying an external force. 2 panels with their electrode surfaces facing each other, Il! The first panel and the second panel are bonded together via several insulating spacers, and the contact position of the first panel and the second panel is determined from the second panel when a voltage is applied to each of the two sets of parallel electrode terminals at fixed time intervals. The configuration is such that a determination is made based on the potential obtained for each @ [Problem to be solved by the invention] However, in the above-mentioned conventional technology, the uniformity of the electrodes having a constant resistance value and the In the vicinity of the point where the parallel electrode terminals intersect, the linearity of the potential appearing on the electrode with a certain resistance value is impaired, widening the effective range in which the position of the pressed point on the sword device can be detected with high precision. [Means for solving the problems] The input device of the present invention has electrodes formed almost uniformly on the surface,
A first substrate on which two sets of strip-shaped parallel electrode terminals having a sheet resistance smaller than that of the electrodes are disposed to intersect with each other, and a flexible second substrate on which electrodes are formed on the surface thereof are separated by a plurality of spacers. In an input device formed such that the electrodes face each other through a wire, a sheet resistance number of a portion where two sets of parallel electrode terminals on the first substrate intersect is set to have a sheet resistance smaller than that of the parallel electrode terminals. Characteristic 〇〔work
Figures 1 to 3 show the basic structure of the present invention, which explains the operation of the present invention in detail based on the drawings.
In (6), the electrode 2 and the ilt electrode terminal 1 having a smaller sheet resistance than the electrode 2 are formed on the substrate 4.

Next, as shown in FIGS. 2(a) and 2(b), an electrode 6 is formed on the other substrate 7, and these are connected through a spacer 8 and a plurality of convex spacers 9 as shown in FIG. They are pasted together so that the electrodes face each other to form an input device.

Here, as shown in FIG. 1 (α), i! By forming electrode terminals, it is possible to widen the effective range in which the position of the pressed point can be detected with high precision.This principle will be explained below.

In order to detect the X direction in the input device of the present invention, as shown in FIG. 4, switch groups 10 and 10' are set to 0, IF7.
11 and 11' are turned on. At this time, the equivalent circuit in the X direction is as shown in FIG. In FIG. 5, R(
What is R (electrode terminal), R (second electrode terminal), and R (electrode)?
The sheet resistance values of electrode terminal 1, second electrode terminal 5, and electrode s2 are shown, respectively. AI from this equivalent circuit! ! Upper a point C
The potential at the point V 6 sV b s V 6 is Vα =V.

Here, in order for the potentials on AM to be the same, R (second electrode terminal) only needs to satisfy R (second 1! pole terminal).

In other words, the second
By providing the electrode terminals, the potentials on All1I and B line become constant, so if the voltage Wt2 and electrode terminal 1 are uniform, highly accurate position detection is possible at any position on electrode 2. .

It is clear that the above also applies to the Y direction.

〔Example〕

(Example 1) In FIGS. 1 to 3, the substrate 4 includes 1.1 glass of glass,
For the electrode 2, a carbon paste with a sheet resistance of 1 to 4 Ω was used. For the electrode terminal 1, a carbon paste with a sheet resistance of 100 Ω was used. For the substrate 7, a 188μ PKT film was used. For the MIL pole 6, a sheet resistance of 500 Ω was used. Also, the board size is 138 mm in the X direction and 138 mm in the Y direction.
The direction was 80M.

First, unlike the conventional example, without providing the second electrode terminal 5,
When this portion was also formed using only carbon paste, the linearity error in the X direction was 4.3%.

Here, the linearity error is defined as ◎ In addition, the equipotential lines at this time are shown in Figure 6, and it can be seen that the linearity is broken at the four ends of the Hanel. 101EIX10 Inside the intestine 0 Also, the dashed-dotted line 12 in the figure is an ideal equipotential line calculated from the distance from AIs, which is the boundary line between electrode 2 and electrode terminal 1, and the actual $120 is the measured value. ) Next, when silver paste with a sheet resistance of 3 Ω was printed on the 5 parts of the second 1-electrode terminal on this panel, the linearity error was 2.0%, and at this time The equipotential lines are shown in Figure 7. Here, since the surface resistance value of the second electrode terminal 50 is considerably lower than the value determined by the above-mentioned equation (2), some error due to this is seen as shown in FIG.

(Example 2) In Example 1, the film thickness of the silver paste forming the second electrode terminal 5 was reduced to have a sheet resistance of 7Ω/. At this time,
The linearity error of 3.5% before providing the second electrode terminal 5 became 0.6%.

(Example 5) In Example 1, the electrode terminal 1 was plated with nickel. This sheet resistance is 10Ω.

The second electrode terminal 5 was made of α4Ω4 silver paste. At this time, the linearity error of 3.7% before providing the second electrode terminal 5 became 0.8%.

In addition, in Examples 1 to 3, electrode 2, electrode terminal 1
, the material and sheet resistance value of the second electrode terminal 5 are as described in (2) above.
The one that satisfies the formula was the best from the experiment, but even if this is not completely satisfied, the linearity error can be reduced by forming a second electrode terminal with a smaller sheet resistance value than the electrode terminal. It was confirmed.

〔Effect of the invention〕

As described above, according to the present invention, the provision of the second electrode terminal has the effect of widening the effective range in which the position of the pressed point on the input device can be detected with high precision. Because it is wider, the external shape of the input device can be made much smaller than conventional ones.

[Brief explanation of drawings]

1 to 3 are diagrams showing the basic structure of the input device of the present invention, and FIGS. 4 and 5 are diagrams showing the principle of the input device of the present invention. Also, FIG. 6 shows equipotential lines of the conventional input device, and FIG. 7 shows equipotential lines of the input device of the present invention. In the figure, 1... Electrode terminal, 2... Electrode 4... Substrate, 5... Second electrode terminal. Applicant: Seiko Epson Co., Ltd. Agent: Tsutomu Mogami, Patent Attorney, and one other person''. Figure 1 (α) C) Figure aa2

Claims (1)

[Claims] A first substrate on which electrodes are formed almost uniformly on the surface thereof, and two sets of strip-shaped parallel electrode terminals having a sheet resistance smaller than the electrodes are provided on the electrodes so as to intersect with each other, and a flexible substrate on which electrodes are formed on the surface thereof. In an input device in which a second substrate is formed such that the electrodes face each other via a plurality of spacers, the sheet resistance of the intersection of two sets of parallel electrode terminals on the first substrate is An input device characterized by having a sheet resistance smaller than that of an electrode terminal.