1. Structure
Analog 8-wire resistive technology is similar to analog 4-wire resistive and was developed as an advanced version of it.
The structure and sensing method of 8-wire resistive technology is same as 4-wire resistive technology. Two transparent conductive sheets are facing. One sheet has electrodes on right and left sides, and the other sheet has electrodes on top and bottom sides. Voltage is imposed on the sheet with electrodes on right and left sides, then a touched point in X direction is detected as the voltage is measured by the other sheet. Then, voltage is imposed on the sheet with electrodes on top and bottom sides, then a touched point in Y direction is detected as the voltage is measured by the other sheet.
It seems the same as the analog 4-wire resistive technology, but there are additional wirings connected to each electrode in analog 8-wire resistive technology. Each electrode is added with one more wiring. These added wirings work as supplemental electrodes and measure the voltage on each electrode, then feedback the information to the controller.
Advantage of analog 8-wire to analog 4-wire resistive technology
Resistive technology requires a task called “calibration” before using it. It is the task to match the touched points on the touch screen with positional data of cursor on the display.
Analog 4-wire resistive technology required calibration not only at the beginning but regularly because touch detecting points are gradually going off the alignment due to change of resistance value on wiring and/or connector parts with the passage of time. In analog 8-wire resistive technology, supplemental electrodes measure the voltage on each electrode automatically, and feedback the measured values to the controller. The voltage detected at touching is transformed into locational information in the relative ratio with the feedback voltage. In this way, the effects of voltage change at electrodes can be cancelled, thus recalibration would not be required.
Analog 8-wire resistive technology is better than analog 4-wire resistive technology because it corrects the alignment automatically and saves the trouble of recalibration. But, the demand for 8-wire resistive sensors is decreased after 1990s. This is because the design and materials of resistive touch screens have been improved, and the recent 4-wire resistive touch screens can be used for long enough without recalibration in many applications.
2. Sensing Method
The sensing method of analog 8-wire resistive is the same as analog 4-wire resistive technology
Touch Technologies
- Resistive Touch Technology
- Capacitive Touch Technology
- Surface Acoustic Wave Touch Technology
- Infrared Touch Technology
