Capacitive sense array for detecting passive touch objects and an active stylus
First Claim
1. An apparatus, comprising:
- a capacitive sense array and a processing device;
wherein;
the capacitive sense array is configured to detect a presence of a passive touch object or a stylus, wherein the capacitive sense array is configured to receive a first transmission signal from the stylus via capacitive coupling between the capacitive sense array and the stylus to detect the presence of the stylus, and receive a second transmission signal from the processing device to detect the presence of the passive touch object;
the processing device is coupled to the capacitive sense array, and configured to wirelessly transmit a synchronization signal to the stylus via a wireless communication link, and determine the stylus location on the capacitive sense array based on the first transmission signal;
the first transmission signal is modulated from the synchronization signal by incorporating additional data associated with the stylus into the synchronization signal, wherein the additional data includes stylus acceleration data; and
in accordance with modulation of the synchronization signal, time periods of the first transmission signal are synchronized to time periods of the second transmission signal, such that the first transmission signal is transmitted to and received at the capacitive sense array during time periods when the second transmission signal is not transmitted by the processing device.
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Accused Products
Abstract
A system comprising a sensing device and a capacitive sense array configured to detect a presence of a passive touch object and a stylus where the capacitive sense array receives a transmit signal from the stylus via capacitive coupling. The system further comprising a processing device configured to determine the stylus location on the capacitive sense array based on the transmit signal and to synchronize the stylus to the capacitive sense array. A system further comprises a demodulation block to extract additional data that is modulated into the transmit signal by the stylus. The demodulation block is configured to extract the additional data by amplitude shift keying. The additional data comprises at least one of an applied force value of the stylus tip, a button status data, a battery status data, or a stylus acceleration data.
68 Citations
20 Claims
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1. An apparatus, comprising:
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a capacitive sense array and a processing device; wherein; the capacitive sense array is configured to detect a presence of a passive touch object or a stylus, wherein the capacitive sense array is configured to receive a first transmission signal from the stylus via capacitive coupling between the capacitive sense array and the stylus to detect the presence of the stylus, and receive a second transmission signal from the processing device to detect the presence of the passive touch object; the processing device is coupled to the capacitive sense array, and configured to wirelessly transmit a synchronization signal to the stylus via a wireless communication link, and determine the stylus location on the capacitive sense array based on the first transmission signal; the first transmission signal is modulated from the synchronization signal by incorporating additional data associated with the stylus into the synchronization signal, wherein the additional data includes stylus acceleration data; and in accordance with modulation of the synchronization signal, time periods of the first transmission signal are synchronized to time periods of the second transmission signal, such that the first transmission signal is transmitted to and received at the capacitive sense array during time periods when the second transmission signal is not transmitted by the processing device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method comprising:
at a processing device coupled to a capacitive sense array that is configured to detect a presence of a passive touch object or a stylus; wirelessly transmitting a synchronization signal to the stylus via a wireless communication link; determining that the capacitive sense array receives a first transmission signal from the stylus via capacitive coupling between the capacitive sense array and the stylus for detecting the presence of the stylus, wherein; the capacitive sense array is further configured to receive a second transmission signal from the processing device to detect the presence of the passive touch object; the first transmission signal is modulated from the synchronization signal by incorporating additional data associated with the stylus into the synchronization signal, wherein the additional data includes stylus acceleration data; and in accordance with modulation of the synchronization signal, time periods of the first transmission signal are synchronized to time periods of the second transmission signal, such that the first transmission signal is transmitted to and received at the capacitive sense array during time periods when the second transmission signal is not transmitted by the processing device; and determining the stylus location on the capacitive sense array based on the first transmission signal. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A system comprising:
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a capacitive sense array, a stylus and a processing device; wherein; the capacitive sense array is configured to detect a presence of a passive touch object or the stylus, wherein the capacitive sense array is configured to receive a first transmission signal from the stylus via capacitive coupling between the capacitive sense array and the stylus to detect the presence of the stylus, and receive a second transmission signal from the processing device to detect the presence of the passive touch object; the processing device is coupled to the capacitive sense array, and configured to wirelessly transmit a synchronization signal to the stylus via a wireless communication link, and determine the stylus location on the capacitive sense array based on the first transmission signal; the first transmission signal is modulated from the synchronization signal by incorporating additional data associated with the stylus into the synchronization signal, wherein the additional data includes stylus acceleration data; and in accordance with modulation of the synchronization signal, time periods of the first transmission signal are synchronized to time periods of the second transmission signal, such that the first transmission signal is transmitted to and received at the capacitive sense array during time periods when the second transmission signal is not transmitted by the processing device.
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Specification