JPS60198021A - Sheet keyboard - 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 The present invention comprises a lower support sheet and an upper support sheet each supporting one strip-shaped conductive coat, and a spacer sheet between these support sheets, The spacer sheet forms at least one switch chamber, in which conductive conductive sheets r, The present invention relates to a sheet keyboard in which the keyboard contacts at least one letter position.

Various sheet keyboards are known on the market. In this known sheet keyboard, both conductive coats are each formed by a circular ring and a plurality of parallel strings contained therein. These parallel chords of both circular rings are orthogonal to each other. In the switch chamber, therefore, the double ring and the string face each other at the point where they intersect. Overall, only a few areas of the adhesive on both support sheets in the switch compartment and small areas with respect to the switch compartment surface are free of electrically conductive coating.

In other sheet keyboards, the conductive coats are each formed by one circular surface. These circular surfaces must not be made too small, since otherwise the desired contact will not be ensured when pressed.

It was found that the support sheet deforms inside the switch room under the influence of various environmental factors such as fluctuations in air humidity and changes in ambient temperature. Furthermore, it is necessary to consider particles that form flat spots in the conductive coating. Particularly if the spacer sheet is thin, the above-mentioned fact can lead to uncontrollable short circuits even without suppression operations. These shorts in the conductive coat are therefore particularly troublesome, since they appear and disappear again from time to time, and therefore they are often elusive.

Through various experiments, it has been found that the larger the surface of the conductive coat facing inside the switch chamber, the more likely such short circuits will occur. The object of the invention is therefore to construct a sheet keyboard of the type mentioned at the outset in such a way that the surface of the conductive coat facing into the switch chamber is small with respect to the switch chamber surface, but which is capable of suppressing operation. The structure should be such that contact is not likely to be uncertain even if such procedures are carried out.

According to the invention, in a sheet keyboard of the type mentioned at the outset, the above-mentioned problem is solved in the following way: in the switch compartment, the upper support sheet is coated with a conductive layer, or the upper support sheet is coated with a conductive layer other than at several intersection points. The conductive coating of the lower support sheet faces the upper support sheet only in areas where there is no conductive coating other than at or at multiple intersections within the switch chamber. It will be resolved as appropriate. This limits the locations where the regions of the conductive coat face each other to the locations where they intersect. The crossover point itself is very small compared to the interior of the switch chamber. The provision of at least two, particularly preferably several, crossing points ensures that the required contact takes place when the suppression operation is carried out. In contrast to a flat contact circular surface in the center of the switch chamber, in the present invention the contact area is divided into several limited intersection points. The final result is that the probability of an undesirable short circuit occurring is very small. This is because it is unlikely that the particles forming the flat large area would be located exactly at the intersection. A further advantage is that for the silver-containing electrically conductive coat, a lower application amount is actually required than for an electrically conductive coat that covers the entire switch chamber surface.

In an embodiment of the invention, the conductive coat is led from the switch chamber in the connection region, both connection regions are at different points in the switch chamber, and the conductive coat is connected to the intersection point. It is one that extends beyond the point of intersection with the region facing the region. This arrangement of the two support sheets to create the crossover point is advantageous since no narrow tolerances have to be adhered to.

Further reducing the probability of short circuits and reducing the amount of conductive paste required without causing contact deterioration can be achieved by increasing the strip width of the conductive conite in strip form. In any case, this is achieved by K being narrower than the width of the conductor track of the support sheet. It is particularly preferred that the strip width be approximately 19 times the width of the conductor track.

Further particularly advantageous embodiments of the invention emerge from the following description of the exemplary embodiments and from the dependent claims.

The sheet keyboard comprises a lower support sheet l and an upper support sheet 2. Both sheets 1 and 2 are attached to a spacer sheet 8. The spacer sheet 8 is provided with holes forming the switch chamber 4.

Inside the switch chamber 4, the lower support sheet 1 is provided with a conductive coating 5 in the form of a wrist strip. Inside the switch chamber 4, on the upper support sheet 2, there is a conductive coat 6 in the form of a strip. These electrically conductive coats 5 and 6 are connected to conductor tracks 7 and 8 of the lower and upper support sheet. The conductor tracks 7 and 8 extend outside the switching chamber 4.

When pressed on the upper support sheet 2 in the direction of the arrow 9, the conductive coats 5 and 6 come into contact with each other, thereby causing the conductor tracks 7 and 8
are electrically connected. Strip-shaped conductive coat 5
and 6 face each other so as to intersect within the switch chamber 4. The intersection point of these O's is indicated by 10 in FIGS. 2 to 1. These electrically conductive coats 5 and 6 have a connecting region 11 located between the crossing point 10 and the conductor track 80, and a crossing region 1 located between the individual crossing points 10.
2, and a protruding region 18 which is opposite the connecting region 11 to the intersection point 10 and which extends beyond the intersection point 10. The strip-shaped conductive coatings 5.6 are arranged in such a way that they do not face each other in the connection area 11 and the projecting area 18. Within the crossover region 12, the conductive coats face each other only at the crossover point 10. Even if there are some irregularities in the conductive coat layer, such as deposited particles, these will be removed if the conductive coats 5 and 6 are mutually arranged as selected. 6 is not short-circuited, since these conductive coats 5 and 6 face each other support sheet 2 or 1 exactly in the lick area of the conductive coat.

The width B of the strips forming the conductive coats 5 and 6 is actually narrower than the width H of the conductor tracks 7 and 8. This width B is approximately half of the width H. The width B is, for example, 0.5 mm. As a whole, the entire area having the conductive coats 5 and 6 is very small compared to the area of the switch chamber 4. The I/-=L6 surface of these conductive coats 5 is about 5 to 15% of the area of the switch chamber 4.

In the embodiment according to FIG. 2, the conductive coat 5 and the conductive coat 6 each comprise a pair of parallel straight strips 1.
4.15 and 16.17. Strips 14,15 extend at right angles to strips 16 and 17. Said strips 14 and 15 or 1
The distance A between 6 and 17 is approximately the same width as the strip width B. The crossing point 10 is therefore concentric with the switching chamber 4 and its diameter is very small compared to the diameter of the switching chamber 4. For example, the diameter of this circle is 15% of the diameter of the switch chamber 4. For example, the switch chamber diameter is 1
It is about 0 mm.

In the embodiment according to FIG. 3, the conductive coats 5 and 6 are each formed by an elliptical ring 18 or 19. The long axes of the elliptical rings 18 and 19 are substantially perpendicular to each other. In any case, four crossover points 10 occur.

In the embodiment according to FIG. 4, the conductive coat 5 is formed by a circular ring 20. In the embodiment according to FIG. Strips 16 and 17 form conductive coat 6. circular ring 20
is larger than the distance A between the strips 16 and 17. Four crossing points 10 occur on the circle formed by the circular ring 20.

The width B of the circular ring 20 and the oval rings 18 and 19 is the same as the width B of the strips 16 and 17.

In the embodiment according to FIG. 5, the strips 14, 15 intersect the strips 16, 17 at an acute angle. Furthermore, the difference from FIG. 2 is that the strips 14 and 15
16 and 17 are connected to the web 2 in the protruding area 18.
1 and 22. In this example as well, four crossover points 10 occur.

In the embodiment according to FIG. 6, the electrically conductive coat 5 is formed by two strips 23, 24, which run away from the conductor track 7 in a V-shape in the switching chamber 4. It is extending. The conductive coat 6 is formed from eight strips 25, 26, 27, which extend away from the conductor track 8 in a V-shape in the switching chamber 4. In this example 6 crossing sides.

There are 10 locations.

In the embodiment according to FIG. 7, the electrically conductive coat 6 is formed from a cross with two mutually intersecting strips 28 and 29. The conductive coat 5 is formed in the same manner as in FIG.

The intersection of strips 28 and 29 is located approximately 11 in the center of the 2° circular ring. These strips 28 and 2
9 crosses the circular ring 20, so that four crossing points 1o result.

In the embodiment according to FIG. 8, the conductive coat 5 is constructed in the same way as in FIG. The conductive coat 6 is shaped like a star 2
It branches into two branch roads 80 and 31. In this example, three crossover points 10 occur. It is also possible to provide a large number of crossing points with a large number of branching paths.

In the embodiment according to FIG. 9, the electrically conductive coats 5 and 6 are each formed by one individual strip 82 to 88. In this example, only one crossover point 10 occurs.

In the embodiment according to FIG. 10, the conductive coat 6 is provided with branches 80 and 81 corresponding to FIG.

In this example, two crossover points 10 occur. When two crossing points 10 are sufficient, these can also be obtained in the following way, i.e. both the conductive coat 6 and the conductive coat 5 are used strips with branches 80, 81, which are connected to the branches 80. It can also be obtained by making the angles 81 and 81 face each other so as to intersect with each other. The two crossover points 10 can also be made as follows, ie one conductive coat is a circular ring 2.
0 and the other conductive coat can be formed by one individual strip 88.

The support sheets 1 and 2, printed with conductive coatings 5 and 6 and conductor tracks 7 and 8, are applied to the spacer sheet 3. No high precision is required for the tolerance when providing the upper support sheet 2 with respect to the lower support sheet 1. This is because the protruding region 18 thereby allows a displacement in the directions D and E without eliminating the crossing point 10. When pushed in the direction of the arrow 9, the conductive coats 5 and 6 come into contact at 1 to 2, 3, 4 or 6 intersection points 10. This will ensure reliable contact.

The crossover area 12 distributes the crossover points within the switch chamber 4.
This can be changed as required by making it larger or smaller in size. If, for example, in the embodiment according to FIG. 2 it is desired that the crossing point lO be located closer to the edge of the switching chamber 4 than is shown, said distance A is selected to be correspondingly large. Conductive coats 5 and 6
Substantially increasing the total area of -1 has nothing to do with the above, and as a result the probability of short circuits is also not high.

There are numerous further embodiments within the scope of the invention. It is also possible to attach the conductive coat 5 of one drawing to the conductive coat 6 of another drawing.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional view of the sheet keyboard;
The figure is a plan view of the sheet keyboard in the area of the switch compartment, and FIGS. 8 to 10 are plan views corresponding to FIG. 2, showing further embodiments of the sheet keyboard. Reference number in the figure 1...Lower support sheet 2...Upper support sheet 3.
・・Spacer sheet 4・Senken switch chamber 5.6・・
- Conductive coat 7.8...Conductor path 10...Cross point 11...Connection area 12...Cross area 18...
Projection area 14, 15.16.17--Strip 1
8.19-...Oval ring 20...Circular ring 21
．． 22... Web agent Hikaru Esaki Good agent Mitsushi Ezaki JP-A-60-1aao21 (6) JP-A-198-198 (J21 (7) Continuation of page 1 @ Inventor Jürgen-Hersch R4- Germany Federal Republic, Hohenroth, Saalebrig (
(No street address) @Inventor Berthold Stülmel, Federal Republic of Germany, Part, Neustadt/Saale,
Berliner Strasse, 41

Claims (1)

[Scope of Claims] [Scope of Claims] A lower support sheet and an upper support sheet that support a block-shaped conductive coat, and a spacer sheet between these support sheets; The sheets form at least one switch chamber in which the conductive coats in the form of wrist strips are arranged in a cross-opposed manner, and when one support sheet is pressed, the conductive coats are arranged in the at least one cross-section. In the seat/keyboard, the upper supporting seat (
The conductive coat (6) of 2) has a plurality of intersection points (
10) but only in areas without conductive coating facing the lower support "x'-) Q) and in the switch chamber (4) the conductive coat (5) of the lower support sheet (1)
A sheet keyboard, characterized in that it faces the upper support sheet (2) only in areas without an electrically conductive coating, except at the large and plurality of intersection points (10). 2. The conductive two wires (5, 6) are connected to the connection area (11
) from the switch chamber (4), both connection regions (11) are located at different points of the switch chamber (4), and these conductive coats (5, 6) are connected at the intersection point ( 10) Sheet Φ keyboard according to claim 1, characterized in that the protruding area (18) facing the connecting area (11) extends beyond the intersection point (10). 3. Sheet keyboard according to claim 1 or 2, characterized in that all crossing points (10) are located on a closed line. 4. The sheet keyboard according to claim 8, wherein the line is a circle. 5° The inner part is located concentrically with respect to the switch chamber (4), and its diameter is about 15 to 20 times the diameter of the switch chamber (4).
% sheet keyboard according to claim 4. 6. One of the conductive coats (5, 6) is a circular ring (2
A sheet keyboard according to claim 4 or claim 5, characterized in that it corresponds to the circle mentioned above as 0). 7. One of the preceding claims, characterized in that the strip-shaped conductive cords (5, 6) have a consistently the same width (B) in the switch chamber (4). Sheet keyboard by. 8. It is noted that the strip width (B) of the strip-shaped conductive cord (5, 6) is in any case narrower than the conductor path (7, 8) of the support sheet (1, 2). A sheet keyboard according to one of the preceding claims characterized in: Ritsu 9 The width of the strip (B) is the width (H) of the conductor path (7, 8).
) Sheet keyboard according to claim 8, characterized in that the sheet keyboard is half of ). 10, conductive coat (5, 6) is a pair of strips〉-'
Synit keyboard according to one of the preceding claims, characterized in that it is formed by: 14°15:16.17). 11, both of the bare strips (14, 15 or 16, 17) are in the web (18) in the protruding area (18).
21, 22). A sheet keyboard according to claim 10, characterized in that the sheet keyboard is connected by 21, 22). 12, the conductive coat (5, 6) is attached to the oval ring (18, 1
9) Sheet keyboard according to one of the preceding claims, characterized in that it is formed by: 13. The preceding claims are characterized in that the conductive cores (5, 6) are formed in the cross region (12) in the form of a star (30, 81) or a cross (28, 29). A sheet keyboard according to one of the following items.