METHOD OF UPDATING BASELINE OUTPUT VALUES OF TOUCH PANEL

• US 20120262395A1
• Filed: 04/10/2012
• Published: 10/18/2012
• Est. Priority Date: 04/12/2011
• Status: Abandoned Application

• Current Assignee: Raydium Semiconductor Corporation
• Original Assignee: Raydium Semiconductor Corporation
• Inventors: CHAN, CHIEN YU
• Application Number:
  US13/443,425
• Publication Number:
  US 20120262395A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

An updating method for baseline output values of a touch-sensing panel is disclosed. The touch-sensing panel includes a plurality of X-directional lines and a plurality of Y-directional lines. The X-directional lines and Y-directional lines are arranged intersecting one another so as to form a sensing grid with a plurality of sensing nodes. The method includes the following steps: performing a first scan when the touch-sensing panel is not touched so as to obtain a plurality of first baseline output values; performing a second scan after the touch-sensing panel is touched so as to obtain plurality of touch output values; and updating the baseline output values on the sensing nodes based on a threshold, the first baseline output values and the touch output values.

Claims

1. A method of updating baseline output values of a touch-sensing panel, the touch-sensing panel comprising a plurality of first-directional lines and a plurality of second-directional lines, the first-directional line and second-directional lines arranged intersecting one another, so as to form a sensing grid with a plurality of sensing nodes, the method comprising the steps of:

performing a first scan when the touch-sensing panel is not touched, so as to obtain a plurality of first baseline output values on the sensing nodes;

performing a second scan after the touch-sensing panel is touched, so as to obtain a plurality of touch output values on the sensing nodes; and

updating the baseline output values on the sensing nodes based on a threshold, the first baseline output values, and the touch output values.

2. The updating method according to claim 1, wherein the step of updating the baseline output values of the sensing nodes comprises:

obtaining a difference value by subtracting the touch output value by the first baseline output value on each sensing node;

retaining the first baseline output value as the baseline output value on the sensing node when the difference value is greater than the threshold; and

updating the baseline output value with a second baseline output value when the difference value is smaller than the threshold value.

3. The updating method according to claim 2, wherein the second baseline output value is determined by the first baseline output value, the touch output value and a weighted index on the sensing node.

4. The updating method according to claim 3, wherein the second baseline output value is an average of the first baseline output value and the touch output value.

5. The updating method according to claim 3, wherein the weighted index is a temperature factor.

6. A method of updating baseline output values of a touch-sensing panel, the touch-sensing panel comprising a plurality of first-directional lines and a plurality of second-directional lines, the first directional-lines and second-directional lines arranged intersecting one another, so as to form a sensing grid with a plurality of sensing nodes, the method comprising the steps of:

performing a first scan when the touch-sensing panel is not touched, so as to obtain a plurality of first baseline output values on the sensing nodes;

performing a second scan after the touch-sensing panel is touched, so as to obtain a plurality of touch output values on the sensing nodes;

determining a touch node of the touch-sensing panel based on the baseline output values and the touch output values; and

updating the baseline output values based on the touch node.

7. The updating method according to claim 6, wherein the step of determining the touch node of the touch-sensing panel comprises:

obtaining the largest voltage difference value by subtracting the touch output values by the baseline output values; and

determining one of the sensing nodes to be the touch node based on the largest voltage difference value.

8. The updating method according to claim 7, wherein the step of updating the output values on the sensing nodes based on the touch node comprises steps of:

selecting a plurality of first nodes from the sensing nodes with the touch node being a center;

retaining the baseline output values as the voltages on the first nodes; and

updating the voltages of the nodes other than the first nodes with the touch output values.