LED circuit and touch sensing method
The invention discloses a LED circuit and a touch sensing method. Said method, as applied to an array of LEDs, comprises the following steps. First, a driving signal is provided. The driving signal is configured to set at least one of the LEDs in a driven mode or a sensing mode. When a LED is set in the sensing mode, it receives an environmental light, whose intensity is then compared to a first threshold. When said intensity is below that threshold, the location corresponding to the LED is marked as a touch location.
1. A touch sensing method for a LED array, the LED array including a plurality of LEDs, the touch sensing method comprising:
providing a driving signal configured to set at least one of the LEDs in a driven mode or a sensing mode;
receiving, by the at least one of the LEDs, an environmental light when the at least one of the LEDs is set in the sensing mode;
determining whether the intensity of the environmental light is below a first threshold; and
marking the location corresponding to the at least one of the LEDs as a touch location when the intensity of the environmental light is below the first threshold,
wherein the step of determining whether the intensity of the environmental light is below the first threshold further comprises:
obtaining a photocurrent generated by the at least one of the LEDs according to the environmental light; and
determining whether the intensity of the photocurrent is below a second threshold,
wherein the intensity of the environmental light is below the first threshold when the intensity of the photocurrent is below the second threshold.
2. The touch sensing method according to claim 1 , wherein the driven mode corresponds to a first level of the driving signal, and the sensing mode corresponds to a second level of the driving signal.
3. The touch sensing method according to claim 1 , further comprising:
generating, by the at least one of the LEDs, an emitted light when the at least one of the LEDs is set in the driven mode.
4. The touch sensing method according to claim 3 , wherein the spectrum of the environmental light differs from the spectrum of the emitted light.
5. The touch sensing method according to claim 3 , further comprising:
setting concurrently the LEDs of the LED array in the sensing mode during a sensing period.
6. A LED circuit, comprising:
a LED array including a plurality of LEDs;
a driving module coupled to the LED array and providing, subject to a first control signal, a first current path;
a sensing module coupled to the LED array and providing, subject to a second control signal, a second current path; and
a processing module coupled respectively to the driving module and the sensing module and configured to selectively provide the first control signal or the second control signal;
wherein on the first current path at least one of the LEDs is set in a driven mode, and on the second current path at least one of the LEDs is set in a sensing mode;
wherein the sensing module determines whether the intensity of an environmental light is below a first threshold when at least one the LEDs is set in the sensing mode, and marks the location corresponding to at least one of the LEDs as a touch location when the intensity of the environmental light is below the first threshold,
wherein the sensing module further obtains a photocurrent generated by at least one of the LEDs according to the environmental light, and determines whether the intensity of the photocurrent is below a second threshold.
7. The LED circuit according to claim 6 , wherein the first control signal corresponds to a first level of a driving signal, and the second control signal corresponds to a second level of the driving signal.
8. The LED circuit according to claim 6 , wherein at least one of the LEDs is forward biased when set in the driven mode, and reverse biased when set in the sensing mode.
9. The LED circuit according to claim 6 , wherein the sensing module determines that the intensity of the environmental light is below the first threshold when the intensity of the photocurrent is below the second threshold.