MULTI-TOUCH DETECTING METHOD FOR DETECTING LOCATIONS OF TOUCHED POINTS ON A TOUCH PANEL

• US 20110007027A1
• Filed: 06/29/2010
• Published: 01/13/2011
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: SHIH, PO-SHENG, CHEN, PO-YANG
• Granted Patent: US 8,564,542 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A multi-touch detecting method is adapted for detecting touched points on a touch panel that includes first and second conductive films. The first conductive film exhibits electric anisotropy, and has a lower resistivity in a first direction. The multi-touch detecting method includes: applying a first voltage to the first conductive film; applying a second voltage greater than the first voltage to the second conductive film; measuring sequentially voltages at different measuring points of the first conductive film; obtaining a first local maximum voltage, a second local maximum voltage and a local minimum voltage from the measured voltages; determining a first location of the touched points based on a location of the measuring point corresponding to the first local maximum voltage; and determining a second location of the touched points based on a location of the measuring point corresponding to the second local maximum voltage.

Claims

1. A multi-touch detecting method adapted for detecting touched points on a touch panel, the touch panel including first and second conductive films insulated from each other and coupled electrically to each other through touch, the first conductive film exhibiting electric anisotropy, and having a lower resistivity in a first direction, the multi-touch detecting method comprising:

applying a first voltage to the first conductive film;

applying a second voltage greater than the first voltage to the second conductive film;

obtaining a first local maximum voltage, a second local maximum voltage and a local minimum voltage from voltages measured at a plurality of different measuring points of the first conductive film, the measuring point corresponding to the local minimum voltage being located between the measuring point corresponding to the first local maximum voltage and the measuring point corresponding to the second local maximum voltage;

determining a first location of the touched points in a second direction transverse to the first direction based on a location of the measuring point corresponding to the first local maximum voltage in the second direction; and

determining a second location of the touched points in the second direction based on a location of the measuring point corresponding to the second local maximum voltage in the second direction.

2. The multi-touch detecting method of claim 1, wherein the voltages are measured in such a manner that while each of the plurality of measuring points is measured, the first voltage is applied to the rest of the plurality of measuring points.

3. The multi-touch detecting method of claim 1, wherein the first local maximum voltage V_n is measured at the n^th measuring point, the first location of the touched points X_a being determined by one of the following equations according to a respective one of the following conditions:

4. The multi-touch detecting method of claim 3, wherein the second local maximum voltage V_m is measured at the m^th measuring point, the second location of the touched points X_b being determined by one of the following equations according to a respective one of the following conditions:

5. The multi-touch detecting method of claim 1, wherein the first local maximum voltage V_n is measured at the n^th measuring point, the second local maximum voltage V_m being measured at the m^th measuring point, the first location of the touched points X_a and the second location of the touched points X_b being determined by the following equations according to respective ones of the following conditions:

6. The multi-touch detecting method of claim 1, the second conductive film exhibiting electric anisotropy, and having a lower resistivity in the second direction, the multi-touch detecting method further comprising:

measuring sequentially voltages at a plurality of different measuring points of the second conductive film;

obtaining a first local minimum voltage, a second local minimum voltage and a local maximum voltage from the voltages measured at the different measuring points of the second conductive film, the measuring point corresponding to the local maximum voltage being located between the measuring point corresponding to the first local minimum voltage and the measuring point corresponding to the second local minimum voltage;

determining a first location of the touched points in the first direction based on a location of the measuring point corresponding to the first local minimum voltage in the first direction; and

determining a second location of the touched points in the first direction based on a location of the measuring point corresponding to the second local minimum voltage in the first direction.

7. The multi-touch detecting method of claim 6, wherein the voltages measured at the different measuring points of the second conductive film are measured in such a manner that while each of the plurality of measuring points is measured, the second voltage is applied to the rest of the plurality of measuring points.

8. The multi-touch detecting method of claim 6, wherein the first local minimum voltage V_s is measured at the s^th measuring point of the second conductive film, the first location of the touched points in the first direction Y_a being determined by one of the following equations according to a respective one of the following conditions:

9. The multi-touch detecting method of claim 8, wherein the second local minimum voltage V_t is measured at the t^th measuring point of the second conductive film, the second location of the touched points in the first direction Y_b being determined by one of the following equations according to a respective one of the following conditions:

10. The multi-touch detecting method of claim 6, wherein the first local minimum voltage V_s is measured at the s^th measuring point of the second conductive film, the second local minimum voltage V_t being measured at the t^th measuring point of the second conductive film, the first location of the touched points in the first direction Y_a and the second location of the touched points in the first direction Y_b being determined by the following equations according to respective ones of the following conditions:

11. A multi-touch detecting method adapted for detecting touched points on a touch panel, the touch panel including first and second conductive films insulated from each other and coupled electrically to each other through touch, the second conductive film exhibiting electric anisotropy, and having a lower resistivity in a certain direction, the multi-touch detecting method comprising:

applying a first voltage to the first conductive film;

applying a second voltage greater than the first voltage to the second conductive film;

measuring sequentially voltages at different measuring points of the second conductive film;

obtaining a first local minimum voltage, a second local minimum voltage and a local maximum voltage from the voltages measured at the different measuring points of the second conductive film, the measuring point corresponding to the local maximum voltage being located between the measuring point corresponding to the first local minimum voltage and the measuring point corresponding to the second local minimum voltage;

determining a first location of the touched points based on a location of the measuring point corresponding to the first local minimum voltage; and

determining a second location of the touched points based on a location of the measuring point corresponding to the second local minimum voltage.

12. The multi-touch detecting method of claim 11, wherein the first local minimum voltage V_s is measured at the s^th measuring point, the first location of the touched points Y_a being determined by one of the following equations according to a respective one of the following conditions:

13. The multi-touch detecting method of claim 12, wherein the second local minimum voltage V_t is measured at the t^th measuring point, the second location of the touched points Y_b being determined by one of the following equations according to a respective one of the following conditions:

14. The multi-touch detecting method of claim 11, wherein the first local minimum voltage V_s is measured at the s^th measuring point, the second local minimum voltage V_t being measured at the t^th measuring point, the first location of the touched points Y_a and the second location of the touched points Y_b being determined by the following equations according to respective ones of the following conditions: