Knowledge

Projected capacitive panel



The touch technology of the projected capacitive panel the projected capacitive touchscreen is an etching of different ITO conductive circuit modules on a two-layer ito conductive glass coating. The etched graphics on the two modules are perpendicular to each other and can be viewed as a continuous change in the X and y directions. Because the x and Y schemas are on different surfaces, they form a capacitor node at their intersection. A slider can be used as the drive line, and the other slider as a detection line. When the current passes through one of the conductors in the drive line, if the outside has a signal that the capacitance changes, then the capacitance node on the other layer of wire will change.

The change of the capacitance value can be measured by the electronic circuit connected with it, and then the digital signal via A/D controller will make the computer do the arithmetic processing to obtain the (x, y) axis position, and then reach the positioning target. Operation, the controller has a power supply flow to the drive line, so that each node and the conductor form a specific electric field. Then, a row-by-column scanning sensing line measures the capacitance variation between its electrodes to achieve multi-point positioning. When the finger or touch media approaches, the controller quickly changes the capacitance value between the touch node and the wire to confirm the position of the touch control. This axis is driven by a set of AC signals, while the response through the touchscreen is measured by the electrodes on the other axes. Users refer to this as a ' cross-type ' sensing, also known as projective sensing. The sensor is coated with an X, Y axis ito pattern, and when the finger touches the touch screen surface, the capacitance below the touch point increases depending on the proximity of the touch point, the continuous scan on the sensor detects changes in the capacitance value, and the control chip calculates the touch point and returns it to the processor.