Touch sensor controller, operating method of touch sensor controller, and touch screen driving circuit
A touch sensor controller for driving a touch sensor that is stacked on a display panel and includes driving electrodes and receiving electrodes crossing the driving electrodes, the touch sensor controller including: a driving circuit configured to sequentially provide driving signals to the driving electrodes; a read-out circuit configured to, in response to the driving signals, generate touch data based on first sensing signals received from the receiving electrodes and generate display noise data based on a second sensing signal received from a first driving electrode to which a driving signal of the driving signals is not applied from among the driving electrodes; and a touch processor configured to determine whether a touch input has occurred on the touch sensor based on the touch data and the display noise data.
1. A touch sensor controller for driving a touch sensor that is stacked on a display panel and includes driving electrodes and receiving electrodes crossing the driving electrodes, the touch sensor controller comprising:
a driving circuit configured to sequentially provide driving signals to the driving electrodes;
a read-out circuit configured to, in response to the driving signals, generate touch data based on first sensing signals received from the receiving electrodes and generate display noise data based on a second sensing signal received from a first driving electrode to which a driving signal of the driving signals is not applied from among the driving electrodes;
a touch processor configured to determine whether a touch input has occurred on the touch sensor based on the touch data and the display noise data;
first receivers respectively connected to the receiving electrodes to receive the first sensing signals;
a second receiver connected to the first driving electrode to receive the second sensing signal;
wherein:
the second receiver includes a second current amplifier including a first input terminal and a second input terminal,
the second sensing signal is applied from the first driving electrode to the first input terminal of the second current amplifier, and
a third sensing signal is received at the second input terminal of the second current amplifier from a second driving electrode to which the driving signal is not applied from among the driving electrodes.
2. The touch sensor controller as claimed in claim 1 , further comprising: an analog-digital converter configured to generate the touch data and the display noise data by analog-digital conversion of outputs of the first receivers and an output of the second receiver, respectively.
3. The touch sensor controller as claimed in claim 2 , wherein: the first receivers each include a first current amplifier including a first input terminal and a second input terminal, a corresponding first sensing signal is received at the first input terminal of the first current amplifier, and the third sensing signal is received at the second input terminal of the first current amplifier from the second driving electrode to.
4. The touch sensor controller as claimed in claim 2 , wherein the first receivers each further include: a first filter configured to filter a frequency of an output signal of a first current amplifier based on a first frequency; and a first gain amplifier configured to amplify an output signal of the first filter.
5. The touch sensor controller as claimed in claim 2 , wherein the second receiver further includes: a second filter configured to filter a frequency of an output signal of the second current amplifier based on a second frequency; and a second gain amplifier configured to amplify an output signal of the second filter.
6. The touch sensor controller as claimed in claim 1 , wherein: the first driving electrode includes at least one channel of driving electrodes spaced apart from at least one driving electrode to which the driving signal is applied from among the driving electrodes, and the first driving electrode is changed as a driving signal is sequentially applied to the driving electrodes.
7. The touch sensor controller as claimed in claim 6 , further comprising a switching circuit configured to select another driving electrode to which a driving signals is not applied from among the driving electrodes as the first driving electrode as the driving signals are sequentially applied to the driving electrodes.
8. The touch sensor controller as claimed in claim 1 , wherein the touch processor is configured to generate compensated touch data by removing the display noise data from the touch data, and determine whether the touch input has occurred based on the compensated touch data.
9. The touch sensor controller as claimed in claim 1 , wherein the touch processor is configured to discard the touch data when the display noise data is equal to or greater than a predetermined value.
10. An operating method of a touch sensor controller for driving a touch sensor that is stacked on a display panel and includes driving electrodes and receiving electrodes crossing the driving electrodes, the operating method comprising:
applying a driving signal to at least one driving electrode from among the driving electrodes;
performing, by first receivers provided in the touch sensor controller, touch sensing; and
performing, by at least one second receiver provided in the touch sensor controller, display noise sensing simultaneously as the touch sensing is performed;
wherein:
each of the first receivers receives a first sensing signal including a touch signal generated based on the driving signal from the receiving electrodes,
the at least one second receiver receives a second sensing signal including display noise from at least one other driving electrode to which the driving signal is not applied from among the driving electrodes,
the at least one second receiver includes a second current amplifier including a first input terminal and a second input terminal,
the second sensing signal is applied from the first driving electrode to the first input terminal of the second current amplifier, and
a third sensing signal is received at the second input terminal of the second current amplifier from a second driving electrode to which the driving signal is not applied from among the driving electrodes.
11. The operating method as claimed in claim 10 , wherein the performing of the touch sensing includes: receiving, by each of the first receivers, the first sensing signal; generating a touch sensing signal by processing the first sensing signal; and generating a compensated touch sensing signal by removing, from the touch sensing signal, a display noise reference signal generated by the display noise sensing.
12. The operating method as claimed in claim 10 , wherein the display noise sensing and the touch sensing are performed during a display period in which an image is displayed on the display panel.