Scan method for a touch panel and touch device

• US 20160077667A1
• Filed: 01/21/2015
• Published: 03/17/2016
• Est. Priority Date: 09/12/2014
• Status: Abandoned Application

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: CHIANG, CHIA-CHANG, TSENG, Yao-Chin
• Application Number:
  US14/601,430
• Publication Number:
  US 20160077667A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G06F 1/3228 Monitoring task completion, e.g. by use of idle timers, stop commands or wait commands
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means
• 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

The present invention relates to a scan method for a touch panel and a touch device. It operates two different Analog-to-Digital Converter calibrations to have different baselines and thresholds corresponding respectively to a cursory scan mode and a fine scan mode. In cursory scan mode, multiple traces are driven simultaneously and the signals from the traces are received simultaneously to enlarge the sensing value so that a touch object with a lower sensing signal is also detected. Further, the cursory scan mode with less electricity cost is used to first determine whether touch objects exists. When the touch objects do exist, the fine scan mode with more electricity cost is then operated. Therefore, the present invention can further reduce the electricity waste.

Claims

1. A scan method for a touch panel comprising steps of:

executing a first Analog-to-Digital Converter calibration (ADC calibration) for a cursory scan mode to get a first baseline and setting a first threshold based on the first baseline;

executing a second ADC calibration for a fine scan mode to get a second baseline, and setting a second threshold based on the second baseline;

entering in the cursory mode or the fine scan mode;

in the cursory mode, driving i traces and receiving multiple first sensing signals of j traces simultaneously and comparing the first sensing signals with the first threshold to determine whether at least one touch object exists;

if the at least one touch object exists, then entering the fine scan mode, wherein “

i” and

“

j”

are positive integers that are bigger than one;

in the fine scan mode, driving multiple first groups of the traces in sequence, wherein each first group of the traces includes k traces;

receiving multiple second sensing signals from multiple second groups of the traces, wherein each second group of the traces includes h traces; and

determining a coordinate of each one of the at least one touch object by the second sensing signals and the second threshold, “

k”

is a positive integer that is smaller than “

i”

but is bigger than one, and “

h”

is a positive integer that is bigger than or equal to one.

2. The scan method for a touch panel as claimed in claim 1, wherein the fine scan mode has steps of:

acquiring the second sensing signals and determining whether at least touch object exists by comparing the second sensing signals with the second threshold;

if the at least one touch object exists, then further determining the coordinate of each one of the at least one touch object and reporting the coordinate of each one of the at least one touch object; and

then back to the step of driving multiple first groups of traces.

3. The scan method for a touch panel as claimed in claim 2, wherein

the k traces of the first groups of the traces and the h traces of the second groups of the traces are the same traces;

when the second ADC calibration is executed under self-capacitance scanning, the k traces of the first groups of the traces is driven and the first sensing signals of the k traces of the first groups of the traces are received; and

under self-capacitance scanning, the k traces are driven in sequence and the second sensing signals of the k traces of corresponding second groups of the traces are received until receiving the second sensing signals of all of the traces.

4. The scan method for a touch panel as claimed in claim 3, wherein “

k”

is equal to one.

5. The scan method for a touch panel as claimed in claim 3, wherein “

k”

is bigger than one and when the second sensing signals of each second group of the traces are received in the fine scan mode, the second sensing signals of each second group of the traces are received in a driving sequence, whereby the second sensing signals of the k traces in each second group of the traces are received simultaneously.

6. The scan method for a touch panel as claimed in claim 2, wherein

the traces of the touch panel include multiple first-axis traces and multiple second-axis traces, the k traces of the first groups of the traces are the first-axis traces and h traces of the second groups of the traces are the second-axis traces;

when the second ADC calibration is executed under mutual-capacitance scanning, the k traces of the first groups of the traces are driven and the second sensing signals of the h traces of the second groups of the traces are received;

in the fine scan mode under mutual-capacitance scanning, the k traces of the first groups of the first-axis traces are driven in sequence and the k traces of each first group of the first-axis traces are driven at each time and the second sensing signals of a corresponding second group of the second-axis traces are received in sequence until all of the first-axis traces are driven.

7. The scan method for a touch panel as claimed in claim 6, wherein “

h”

is equal to one and when the second sensing signals of the corresponding second group of the second-axis traces are received, the second sensing signals of all second-axis traces are received in sequence.

8. The scan method for a touch panel as claimed in claim 6, wherein “

h”

is bigger than one and the second sensing signals of the h traces of each second group are received simultaneously in the fine scan mode.

9. The scan method for a touch panel as claimed in claim 1, wherein

the i traces and the j traces are the same traces;

when the first ADC calibration is executed under self-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the i traces are received simultaneously; and

in the cursory scan mode under self-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the i traces are received simultaneously.

10. The scan method for a touch panel as claimed in claim 1, wherein

the traces of touch panels include multiple first-axis traces and multiple second-axis traces;

the i traces are included in the first-axis traces and the j traces are included in the second-axis traces;

when the first ADC calibration is executed under mutual-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the j traces are received simultaneously; and

in the cursory scan mode under mutual-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the j traces are received simultaneously.

11. The scan method for a touch panel as claimed in claim 1 further comprising steps of:

comparing the first sensing signals with the first baseline when no touch object exists in the cursory scan mode; and

adjusting the first baseline or the first threshold based on the comparison result.

12. The scan method for a touch panel as claimed in claim 11 further comprising steps of:

determining whether the first baseline or the first threshold is adjusted before acquiring the second sensing signals in the fine scan mode; and

if the first baseline or the first threshold has been adjusted, adjusting the second baseline or the second threshold based on the adjusted first baseline or the adjusted first threshold.

13. A scan method for a touch panel comprising steps of:

executing a first Analog-to-Digital Converter calibration (ADC calibration) to get a first baseline and setting a first threshold based on the first baseline;

driving i traces and receiving multiple first sensing signals of j traces simultaneously, wherein “

i” and

“

j”

are positive integers that are bigger than one;

comparing the first sensing signals with the first threshold to determine whether at least one touch object exists;

if the at least one touch object do exist, determining a coordinate of each one of the at least one touch object and going back to the step of driving the i traces.

14. The scan method for a touch panel as claimed in claim 13, wherein

the i traces and the j traces are the same traces;

when the first ADC calibration is executed under self-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the i traces are received simultaneously; and

when the i traces are driven and received under self-capacitance scanning, the i traces are driven simultaneously and the first sensing signal of the i traces are received simultaneously.

15. The scan method for a touch panel as claimed in claim 13, wherein

the traces of touch panels include multiple first-axis traces and multiple second-axis traces;

the i traces and the j traces are the different traces, the i traces are included in the first-axis traces and the j traces are included in the second-axis traces;

when the first ADC calibration is executed under mutual-capacitance scanning, the i traces are driven simultaneously and the first sensing signal of the j traces are received simultaneously; and

when the i traces are driven and the first sensing signal of the j traces are received under mutual-capacitance scanning, the i traces are driven simultaneously and the first sensing signal of the j traces are received simultaneously.

16. A touch device comprising:

a touch panel having p traces;

a controller connecting to the touch panel and having

a driving unit;

a receiving unit having at least one sub-receiving unit to receive sensing signals simultaneously;

a memory unit saving a first ADC calibration, a second ADC calibration, a cursory scan mode and a fine scan mode; and

a processor executing following steps when started;

controlling the driving unit to execute the first ADC calibration for the cursory scan mode, obtaining a first baseline by the receiving unit, setting a first threshold based on the first baseline, and storing the first baseline and the first threshold in the memory unit;

controlling the driving unit to execute the second ADC calibration for the fine scan mode, obtaining a second baseline by the receiving unit, setting a second threshold based on the second baseline, and storing the second baseline and the second threshold in the memory unit.

entering in the cursory mode or the fine scan mode;

receiving multiple first sensing signals of j traces simultaneously by the at least one sub-receiving unit in the cursory mode and determining whether at least one touch object exists by the first sensing signals, wherein “

j”

is a positive integer that is bigger than one;

receiving at least one second sensing signal of h traces simultaneously by the at least one sub-receiving unit in the fine scan mode and determining a coordinate of each one of the at least one touch object by the at least one second sensing signal, wherein “

h”

is a positive integer that is bigger than or equal to one.

17. The touch device as claimed in claim 16, wherein

in the cursory scan mode, the processor executes following steps:

controlling the driving unit by the processor to drive i traces simultaneously, wherein “

i”

is a positive integer that is bigger than one;

receiving the first sensing signals of the j traces simultaneously by the at least one sub-receiving unit to acquire the first sensing signals;

comparing the first sensing signals with the first threshold to determine whether the at least one touch object exists; and

if the at least one touch object exists, then entering the fine scan mode; and

in the fine scan mode, the processor executes following steps;

controlling the driving unit by the processor to drive multiple first groups of the traces in sequence, wherein each first group of the traces includes k traces;

receiving the second sensing signals from multiple second groups of the traces by the at least one sub-receiving unit, wherein each second group of the traces includes h traces; and

determining a coordinate of each one of the at least one touch object by the second sensing signals and the second threshold, wherein “

k”

is a positive integer that is smaller than “

i”

but is bigger than one.

18. The touch device as claimed in claim 17, wherein

the k traces of the first groups of the traces and the h traces of the second groups of the traces are the same traces;

when the processor executes the second ADC calibration under self-capacitance scanning, the driving unit drives the k traces of the first groups of the traces, and the second sensing signals of the k traces of the first groups of the traces are received by the at least one sub-receiving unit; and

when the processor executes the fine scan mode under self-capacitance scanning, the driving unit drives the k traces of the first groups of the traces and the second sensing signals of the k traces of the corresponding second groups of the traces are received by the at least one sub-receiving unit until the second sensing signals of all of the traces are received.

19. The touch device as claimed in claim 17, wherein

the p traces of touch panel include multiple first-axis traces and multiple second-axis traces;

the k traces of the first groups of the traces are the first-axis traces and the h traces of the second groups of the traces are the second-axis traces;

when the processor executes the second ADC calibration under mutual-capacitance scanning, the driving unit drives the k traces of the first groups of the traces, and the second sensing signals of the h traces of the second groups of the traces are received by the at least one sub-receiving unit; and

when the processor executes the fine scan mode under mutual-capacitance scanning, the driving unit drives the k traces of the first groups of the first-axis traces in sequence wherein the k traces of each first group of the first-axis traces are driven in sequence at each time, and the second sensing signals of the corresponding second group of the second-axis traces are received in sequence by the at least one sub-receiving unit until all of the first-axis traces are driven.

20. The touch device as claimed in claim 17, wherein

the i traces and the j traces are the same traces and the receiving unit has one sub-receiving unit;

when the processor executes the first ADC calibration under self-capacitance scanning, the driving unit drives the i traces simultaneously, the first sensing signals of the i traces are received simultaneously by the sub-receiving unit; and

when the processor executes the cursory scan mode under self-capacitance scanning, the i traces are driven simultaneously and the first sensing signals of the i traces are received simultaneously by the sub-receiving unit.

21. The touch device as claimed in claim 17, wherein

the p traces of touch panel include multiple first-axis traces and multiple second-axis trace;

the i traces are included in the first-axis traces, the j traces are included in the second-axis traces and the receiving unit has one sub-receiving unit;

when the processor executes the first ADC calibration under mutual-capacitance scanning, the driving unit drives the i traces simultaneously, and the first sensing signals of the j traces are received simultaneously by the sub-receiving unit; and

when the processor executes the cursory scan mode under mutual-capacitance scanning, the driving unit drives the i traces simultaneously and the first sensing signals of the j traces are received simultaneously by the sub-receiving unit.

22. The touch device as claimed in claim 16, wherein the processor further executes following steps:

comparing the first sensing signals with the first baseline when no touch object exists in the cursory scan mode; and

adjusting the first baseline or the first threshold based on the comparison result and storing the adjusted first baseline or the adjusted first threshold back to the memory unit.

23. A touch device comprising:

a touch panel having p traces;

a controller connecting to the touch panel and having

a driving unit;

a receiving unit having at least one sub-receiving unit to receive sensing signals simultaneously; and

a processor; and

a detecting circuit connecting to the touch panel and the controller and having

a memory having

a first register saving a first baseline; and

a second register saving a first threshold;

an ADC having an input connecting to the p traces of the touch panel to receive the sensing signals of the p traces simultaneously and to convert the sensing signals to corresponding sensing values; and

a comparator having

a first input connecting to an output of the ADC to acquire the sensing values;

a second input connecting to the second register of the memory to acquire the first threshold; and

an output of the comparator connecting to the processor,

wherein the comparator compares the sensing values with the first threshold to determine whether the processor should be waked up.

24. The touch device as claimed in claim 23, wherein

the controller have a memory unit saving a first ADC calibration, a second ADC calibration, a cursory scan mode and a fine scan mode;

and

the processor execute following steps when started;

controlling the driving unit to execute the first ADC calibration, obtaining the first baseline for the cursory scan mode by the at least one sub-receiving unit, setting the first threshold based on the first baseline, and storing the first baseline and the first threshold into the first and second register of the memory unit; and

controlling the driving unit to execute the second ADC calibration, obtaining a second baseline for the fine scan mode by the at least one sub-receiving unit, setting a second threshold based on the second baseline, and storing the second baseline and the second threshold into the memory unit of the controller.

25. The touch device as claimed in claim 24, wherein

in the cursory mode, the processor executes following steps:

controlling the driving unit by the processor to drive i traces simultaneously;

controlling the ADC of the detecting circuit to receive multiple sensing signals of j traces simultaneously to obtain the first sensing signals;

comparing the first sensing signals with the first threshold by the comparator of the detecting circuit to determine whether at least one touch object exists;

if the at least one touch object exists, then entering the fine scan mode, wherein “

i” and

“

j”

are positive integers that are bigger than one; and

in the fine scan mode, the processor executes following steps;

controlling the driving unit by the processor to drive multiple first groups of the traces in sequence, wherein each first group of the traces includes k traces;

controlling the at least one sub-receiving unit to receive multiple second sensing signals from multiple second groups of the traces, wherein each second group of the traces includes h traces; and

determining a coordinate of each one of the at least one touch object by the second sensing signals and the second threshold, wherein “

k”

is a positive integer that is smaller than “

i”

but is bigger than one, and “

h”

is a positive integer that is bigger than or equal to one.

26. The touch device as claimed in claim 25, wherein

the k traces of the first groups of the traces and the h traces of the second groups of the traces are the same traces:

when the processor executes the second ADC calibration under self-capacitance scanning, the driving unit drives the k traces of the first groups of the traces, and the second sensing signals of the k traces of the first groups of the traces are received by the at least one sub-receiving unit; and

when the processor executes the fine scan mode under self-capacitance scanning, the driving unit drives the k traces of the first groups of the traces in sequence and the second sensing signals of the k traces of corresponding second groups of the traces are received by the at least one sub-receiving unit until the second sensing signals of all of the traces are received.

27. The touch device as claimed in claim 25, wherein

the p traces of touch panel include multiple first-axis traces and multiple second-axis traces;

the k traces of the first groups of the traces are the first-axis traces and the h traces of the second groups of the traces are the second-axis traces;

when the processor executes the second ADC calibration under mutual-capacitance scanning, the driving unit drives the k traces of the first groups of the traces, and the second sensing signals of the h traces of the second groups of the traces are received by the at least one sub-receiving unit; and

when the processor executes in the fine scan mode under mutual-capacitance scanning, the driving unit drives the k traces of the first group of the first-axis traces in sequence wherein the k traces of the first group of the first-axis traces are driven in sequence at each time, and the second sensing signals of the corresponding second group of the second-axis traces are received in sequence by the at least one sub-receiving unit until all of the first-axis traces are driven.

28. The touch device as claimed in claim 25, wherein

the i traces and the j traces are the same traces;

when the processor executes the first ADC calibration under self-capacitance scanning, the driving unit drives the i traces simultaneously, the first sensing signals of the i traces are received simultaneously by the ADC; and

when the processor executes in the cursory scan mode under self-capacitance scanning, the driving unit drives the i traces simultaneously and the first sensing signals of the i traces are received simultaneously by the ADC.

29. The touch device as claimed in claim 25, wherein

the p traces of touch panel include multiple first-axis traces and multiple second-axis traces, the i traces are included in the first-axis traces the j traces are included in the second-axis traces;

when the processor executes the first ADC calibration under mutual-capacitance scanning, the driving unit drives the i traces simultaneously, and the first sensing signals of the j traces are received simultaneously by the ADC; and

when the processor executes the cursory scan mode under mutual-capacitance scanning, the driving unit drives the i traces simultaneously and the first sensing signals of the j traces are received simultaneously by the ADC.

30. The touch device as claimed in claim 24, wherein the processor further executes following steps:

comparing the first sensing signals with the first baseline by the processor when no touch object exists in the cursory scan mode; and

adjusting the first baseline or the first threshold based on the comparison result and storing the adjusted first baseline or the adjusted first threshold back to the first register or the second register of the memory unit of the detecting circuit.