Positioning method and device for self-capacitance touch screen, touch system

Abstract

The invention discloses a positioning method for a self-capacitance touch screen, comprising the following steps of: receiving frame data from the self-capacitance touch screen and analyzing the current frame data to obtain a transverse channel of the self-capacitance touch screen and a capacitance variable amount of a vertical channel; obtaining the quantity of objects contacting with the self-capacitance touch screen according to the current frame data; when the quantity of the objects is less than or equal to two, calculating coordinates of the objects; or continually receiving the next frame of data. The invention further discloses a positioning device for the self-capacitance touch screen as well as a touch control system with the positioning device. According to the positioning method and device for the self-capacitance touch screen as well as the touch control system disclosed by the invention, the stable and accurate coordinates of two touch objects in two-point touch can be obtained, the change of a coordinate point between a real point and a ghost shadow is avoided, and the precision of the coordinates is improved.

Description

technical field [0001] The invention relates to the field of touch technology, in particular to a positioning method and device for a self-capacitance touch screen, and a touch system. Background technique [0002] The touch screen has been widely used in various electronic products due to its small mechanical loss and small size. Touch screens include resistive touch screens and capacitive touch screens. With the advancement of technology, self-capacitive touch screens are more and more widely used in various devices. During touch detection, the self-capacitance screen detects the horizontal and vertical electrode arrays in turn, and determines the abscissa and ordinate of the touch position according to the change in capacitance before and after the touch, and then combines them into plane coordinates. The self-capacitance scanning method is equivalent to projecting the touch points on the touch screen to the X-axis (horizontal) and Y-axis (longitudinal) directions, and ...

AI Technical Summary

Problems solved by technology

However, if there are two touch points on the touch screen and the two points touch the screen in sequence, the calculated coordinates of the two points will be jittery and unstable points, such as image 3 shown

These two points will switch back and forth between the real point and the ghost image, making the two points very unstable

[0008] 3) When two points are touched, when the two points are too close, it will be misjudged as one point

[0009] like Figure 4 As shown, if the distance between the two objects is too close when the two points are touched, the channel with capacitance change will be continuous, which will cause the two-point touch to be misjudged as a one-point touch for processing.

Images