Electronic device, touch detection circuit, and method for updating reference value of touch screen

Abstract

An electronic device, a touch detection circuit and a method for updating a reference value of a touch screen (2). The method for updating the reference value of the touch screen (2) comprises: acquiring a temperature value (101) of the environment where the touch screen (2) is located; when it is determined that the acquired temperature value is less than a preset temperature threshold (102), and determining that the touch screen (2) When there is a continuous touch area (103) on the device, collect N data frames of the continuous touch area (104); calculate N eigenvalues ​​of the N data frames (105); update the N corresponding to the N data frames according to the N eigenvalues reference values ​​(106); where N>1 and N is an integer. By adopting the above solution, the difference between the reference value and the sensing value of the continuous touch area can be prevented from decreasing with the temperature rise caused by the heat transferred by the touch object, thereby avoiding the phenomenon of low temperature extinction.

Description

technical field [0001] The present application relates to the technical field of touch screens, and in particular, to an electronic device, a touch detection circuit, and a method for updating a reference value of a touch screen. Background technique [0002] At present, most electronic terminal devices on the market (for example, mobile phones, tablet computers, etc.) use capacitive touch screens to realize human-computer interaction. The capacitive touch screens detect user's touch operations through capacitive sensors. Before detecting user operations on the touch screen, the touch screen generally establishes a reference original value, which is obtained by coding and sampling on the touch control chip, and the reference original value reflects the initial state of each sensing node of the capacitive sensor. When a touch object (such as a finger, a stylus, and other objects that can change the inductive capacitance) clicks or draws a line on the touch screen, the capacit...

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Problems solved by technology

[0003] In the process of implementing the present application, the inventor found that at least the following problems exist in the prior art: when the temperature rises or falls, due to the temperature drift characteristic of the capacitive sensor, the original value of the capacitive touch screen will also change accordingly; When the capacitive touch screen is used in the environment, when the user's finger is continuously placed on a certain position on the touch screen, the touch coordinates will be reported normally at the beginning, but then there will be a disappearance phenomenon; where the disappearance phenomenon refers to the touch object on the touch screen. operation but the touch control chip does not report the coordinates; the reason for the disappearance phenomenon is that when the user just puts the finger on the touch screen, the original value of the capacitive sensing node at the position of the finger will decrease, and the current original value is subtracted from the base original value. The value can get a positive difference. When the difference exceeds a certain threshold, the touch control chip will calculate and report the coordinates; however, in a severe cold environment, the temperature of the touch screen is much lower than the temperature of the human finger. When the finger is continuously placed on the same position of the touch screen , the temperature at this position will gradually increase due to the heat conducted by the finger, which will cause the original value of the capacitive sensing node at this position to gradually increase, so that the difference will gradually decrease. When the difference is less than a certain threshold, the finger There will be disappearing dots at the touched position

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