Capacitive -inductive touch screen

Abstract

A touch screen uses a combination of capacitive sensing and inductive sensing applied to the same sensor pattern. A capacitive sensor uses the electric field formed by the columns and rows of the sensor matrix. An inductive sensor uses the magnetic field formed by current flowing in column and row lines to induce an inductive pen. Using the same sensor lines, the magnetic field created by the oscillating inductive pen is detected. Both methods require no moving elements in the sensor and it is possible to combine both method of detections in the same sensor pattern. Using switch matrices, thesensor lines are operated in an open loop fashion for the capacitive detection mode, and are operated in a closed loop fashion for the inductive detection mode.

Description

technical field [0001] The present invention relates to touch screens, and more particularly, to touch screens capable of operating in both capacitive and inductive modes using the same sensor panel. Background technique [0002] The capacitive touch screen can only receive input from fingers, but it can give users a different experience and supports multi-touch input. Resistive touch screens are capable of receiving input from both a finger and a stylus. However, the resistive touch screen requires a large pressure to activate the detection, and the traditional 4 / 5 / 8 wire resistive touch screen only allows single point detection. Although capacitive touch screens give a better experience (sensitivity, multi-touch, and other advantages), some users still prefer to use a stylus, especially for handwriting recognition applications. [0003] Figure 1A A schematic diagram of a prior art inductive touch screen 100 is shown in . In the prior art, interleaved closed-loop curren...

AI Technical Summary

Problems solved by technology

However, resistive touch screens require greater pressure to activate detection, and traditional 4 / 5 / 8-wire resistive touch screens only allow single-point detection

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