Analog 5-wire Resistive touch screen technology
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In 5-wire resistive touch screens, the bottom sheet has equipotential distribution in both X and Y directions, the voltage of the bottom sheet is measured by the top sheet. The main electronics are based on the glass bottom layer, with a uniform voltage applied to the top plastic layer. A touch causes an electrical contact between the top and bottom layers. Depending on the point of touch, the voltages at the four corners of the glass are different, and are measured by a complex algorithm in the controller to calculate the x-y coordinate of the point of touch.
The advantages of the five wire resistance touch screen are that the glass substrate is relatively firm and not easy to deform, and the ITO attached to it can be fully oxidized. The glass material will not absorb water, and its expansion coefficient is very close to that of ITO. The deformation will not cause damage to ITO. The ITO on the upper layer is only used as the lead electrode, and no current flows. Therefore, it is not necessary to require uniform conductivity. Even if it is damaged due to deformation, it will not cause "drift" of the resistance screen.
The electrodes of the five wire resistance touch screen cannot be led out from the four sides by conductive strips like the four wire resistance screen, which will cause short circuit. The electrodes are dispersed into many resistance patterns distributed around the touch screen, and then led out from the four corners. These patterns are used to make the voltage gradient in X and Y directions of the touch screen linear and facilitate coordinate measurement.
When the five wire resistive touch screen works, UL applies the driving voltage vdrive and LR is grounded. The measurement of the X and Y coordinates of the contact is divided into the following two steps:
1. Calculate the Y coordinate, apply the driving voltage vdrive to the ur electrode, the LL electrode is grounded, and the movable electrode is used as the lead out terminal to measure the voltage at the contact point.
2. Calculate the X coordinate, apply the driving voltage vdrive to the LL electrode, the ur electrode is grounded, and the movable electrode is used as the lead end to measure the voltage at the contact point.
Difference structure of 4-wire and 5-wire technologies
The 5-wire resistive touch screen aims to get rid of the disadvantages of the 4-wire resistive touch screen. The structure adopted by the five wire resistive touch screen is that the X and Y electrodes are all made on the ITO layer attached to the glass substrate, while the ITO on the upper layer is only used as the movable electrode. The X and Y electrodes of the bottom layer ITO lead out UL, ur, ll, LR from four corners, and the upper layer active electrode is added, so there are five lines in total.
Just same as analog 4-wire resistive technology, an analog 5-wire resistive sensor consists of top and bottom sheets which are facing each other with a gap in between. Unlike analog 4-wire resistive technology, electrodes are placed on four corners of the bottom sheet in analog 5-wire technology.
| Specification | 4-wire resistive technologies | 5-wire resistive technologies |
| Speed of response(in milliseconds) | 10 ms maximum | 21 ms at 9600 baud |
| Accuracy | 3 mm maximum error | <= 1.0% within precision area. Outside precision area, linearly increasing to 2% at the edge of the active area |
| Light transmission | 80-85% | 70-78% |
| touch resolution | 1024 x 1024 | 4096 x 4096 |
| life span | > 5 million touches | > 35 million touches |
Resistive Technology : Analog 4-wire Resistive, Analog 5-Wire Resistive, Analog 7-wire Resistive, Analog 8-wire Resistive, Features of resistive technology
Capacitive Technology: Surface Capacitive touch technology, Projected Capacitive touch technology
