Touchscreen
Diagonal touchscreen arrays

In 2015, a new diagonal array, suited to a range of touchscreen and keypad technologies, was invented and patented by Ron Binstead of Binstead Designs Ltd.

The diagram (left) shows how a group of 6 parallel conductive elements, folded back on themselves (at right angles), can create a triangular array of 15 unique intersections. An x/y array, with 6 conductive elements, would only have created a maximum of 9 unique intersections.

Although conductive elements are normally connected to a terminal at one end of the conductor, the left diagram shows that these folded elements can be terminated at the fold, thereby forming split (or bifurcated) elements.

A square/rectangular diagonal array can be formed by double folding the parallel conductors - see diagram on the right. Two connectors could be fitted at the folds, on opposite sides of the array. Alternatively, a single connector can be fitted at one end of the array - as shown in the diagram.

Cylindrical touchscreens.

Diagonal sensing elements can also be formed into a seamless cylindrical array. The diagram on the right shows a split, 9 I/O, bi-state cylindrical layout, with 36 unique intersections - all the I/O lines connected to one end of the cylinder (a standard x/y array would require horizontal I/O lines entering the side of the cylinder). Unsplit diagonal sensing elements can also be formed into cylinders, but 9 I/Os would only create 20 (5x4) unique intersections. These cylinders can be physically transformed into complex 3 dimensional shapes, by a range of different methods, such as blow molding, vacuum forming, etc..

A similar layout is possible for a complementary cylindrical LED display - see Charlieplexing#Diagonal arrays.

Infinitely wide touchscreens.

Touchscreen width is normally restricted by the resistance of the conductive material used. As the width of an x/y touchscreen is increased, eventually the resistance of the horizontal conductors becomes too great for the touchscreen to work properly."Infinitely" wide touchscreens are possible, however, when using diagonal wiring, because track lengths are always 1.414 x the height of the touchscreen ⌈ H 2 ⌋ {\textstyle \left\lceil H{\sqrt {2}}\right\rfloor }, and are independent of touchscreen width (see diagram on right).

There are two types of PCT: mutual capacitance and self-capacitance
length_constraints:number_paragraphs[6], detectable_format:json_format