CAPACITIVE TOUCH DETECTING DEVICE AND METHOD USING LEVEL SHIFT, AND DISPLAY DEVICE USING THE SAME

• US 20150331521A1
• Filed: 07/28/2015
• Published: 11/19/2015
• Est. Priority Date: 09/01/2010
• Status: Active Grant

• Current Assignee: G2touch Co Ltd
• Original Assignee: Sung Ho Lee
• Inventors: LEE, Sung Ho
• Granted Patent: US 9,772,732 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

Provided is a touch detecting device that detects occurrence of a level shift phenomenon of a voltage variation to thus acquire a touch signal, when a touch capacitance due to a touch input is added to a common electrode capacitance formed between a common electrode and a sensor pattern. Accordingly, the touch signal may be stably obtained in spite of external noise, and an influence due to a parasitic capacitance may be minimized.

Claims

1. A capacitive touch detecting device for detecting occurrence of a touch capacitance (Ct) by an approach of a bodily finger or a touch input instrument such as a conductor similar to the bodily finger, the capacitive touch detecting device comprising:

at least one sensor pattern that forms the touch capacitance (Ct) between the touch input instrument and the sensor pattern, and that is disposed at a distance spaced from a common electrode to thus form a common electrode capacitance (Cvcom); and

a level shift detecting unit that is connected to the sensor pattern, and that detects a level shift occurs in a voltage variation in the sensor pattern at the time of occurrence of a touch input, with respect to another voltage variation in the sensor pattern at the time of non-occurrence of a touch input, to thereby acquire a touch signal,

wherein the common electrode has a common voltage (Vcom) level that alternates at a predetermined frequency, and

wherein the level shift detecting unit detects a level shift between the voltage variations arising from the sensor pattern by the common voltage (Vcom) before and after the occurrence of the touch input,

wherein the level shift detecting unit detects the level shift in the sensor pattern at the rising time and/or falling time of the common voltage level.