Combination touch and transducer input system and method
A combination touch and transducer input system is provided, which facilitates user input into an electronic system with a finger and/or a transducer (e.g., a stylus). The system includes a transducer configured to generate an electric field, and a sensor including an array of electrodes and a controller. The transducer is configured to transmit digital data, such as pen pressure data and switch status data, to the sensor. For example, the transducer comprises electronic circuitry configured to encode the digital data in a signal for transmission to the sensor. The sensor controller is configured to operate both in a touch sensing mode and in a transducer sensing mode. During the touch sensing mode, the controller determines a position of a proximate object (e.g., a finger) by capacitively sensing the object with the array of electrodes. During the transducer sensing mode, the controller determines a position of the transducer based on a signal received by the array of electrodes from the transducer, and also receives and decodes the digital data encoded in the received signal. Digital data can be encoded in a signal using any suitable digital modulation techniques, such as a Frequency-Shift Keying (FSK) technique.
1. A method of controlling a position input system which includes an array of electrodes, the method comprising:
time-divisionally controlling the array of electrodes in a touch sensing mode and in a stylus sensing mode,
in the touch sensing mode, supplying defined signals to the array of electrodes and measuring attributes of signals capacitively sensed by the array of electrodes to detect an object positioned on the array of electrodes, and
in the stylus sensing mode, controlling the array of electrodes to selectively form loop electrodes in which signals are electromagnetically induced by stylus signals transmitted from a stylus and measuring attributes of the electromagnetically induced signals to detect the stylus positioned on the array of electrodes.
2. The method of claim 1 , comprising:
remaining in the stylus sensing mode while the stylus is detected on the array of electrodes.
3. The method of claim 1 , wherein the array of electrodes include first electrodes disposed along a first direction and second electrodes disposed along a second direction different from the first direction.
4. A position input system, comprising:
an array of electrodes; and
an integrated circuit configured to:
time-divisionally control the array of electrodes in a touch sensing mode and in a stylus sensing mode,
in the touch sensing mode, supply defined signals to the array of electrodes and measure attributes of signals capacitively sensed by the array of electrodes to detect an object positioned on the array of electrodes, and
in the stylus sensing mode, control the array of electrodes to selectively form loop electrodes in which signals are electromagnetically induced by stylus signals transmitted from a stylus and measure attributes of the electromagnetically induced signals to detect the stylus positioned on the array of electrodes.
5. The position input system of claim 4 , wherein the integrated circuit is configured to:
remain in the stylus sensing mode while the stylus is detected on the array of electrodes.
6. The position input system of claim 4 , wherein the array of electrodes include first electrodes disposed along a first direction and second electrodes disposed along a second direction different from the first direction.
7. A controller for use with a position input system, the position input system including an array of electrodes, the controller comprising:
an integrated circuit, which is coupled to the array of electrodes and configured to:
time-divisionally control the array of electrodes in a touch sensing mode and in a stylus sensing mode,
in the touch sensing mode, supply defined signals to the array of electrodes and measure attributes of signals capacitively sensed by the array of electrodes to detect an object positioned on the array of electrodes, and
in the stylus sensing mode, control the array of electrodes to selectively form loop electrodes in which signals are electromagnetically induced by stylus signals transmitted from a stylus and measure attributes of the electromagnetically induced signals to detect the stylus positioned on the array of electrodes.
8. The controller of claim 7 , wherein the integrated circuit is configured to:
remain in the stylus sensing mode while the stylus is detected on the array of electrodes.
9. The controller of claim 7 , wherein the array of electrodes include first electrodes disposed along a first direction and second electrodes disposed along a second direction different from the first direction.