Control unit, sensing device for a capacitive touch panel and method therefor
First Claim
1. A sensing device for a capacitive touch panel, the capacitive touch panel being rectangular and having a transparent substrate and a sensing layer on the transparent substrate, the sensing layer being transparent and electrically conductive, the capacitive touch panel further having a first X side, a second X side, a first Y side and a second Y side, the sensing device comprising:
- a first X side switch circuit, respectively electronically connected to the first X side;
a second X side switch circuit, respectively electronically connected to the second X side;
a first Y side switch circuit, respectively electrically connected to the first Y side;
a second Y side switch circuit, respectively electrically connected to the second Y side;
a sensing source, providing a sensing signal to the first X side switch circuit, the second X side switch circuit, the first Y side switch circuit and the second Y side switch circuit; and
a control circuit, receiving the sensing signal generated by the sensing source, the control circuit further comprising;
a first current measurement circuit, receiving a first X side current signal generated by the first X side switch circuit or a first Y side current signal generated by the first Y side switch circuit;
a second current measurement circuit, receiving a second X side current signal generated by the second X side switch circuit or a second Y side current signal generated by the second Y side switch circuit;
a control unit, comprising;
a first analogue/digital conversion circuit, converting a first X side analogue signal generated by the first X side current signal into a first X side digital signal, or converting a first Y side analogue signal generated by the first Y side current signal into a Y side digital signal; and
a second analogue/digital conversion circuit, converting a second X side analogue signal generated by the second X side current signal into a second X side digital signal, or converting a second Y side analogue signal generated by the second Y side current signal into a second Y side digital signal; and
a location determining unit, electrically connected to the first analogue/digital conversion circuit and the second analogue/digital conversion circuit, and comprising;
an X coordinate determining device, receiving the first X side digital current signal and the second X side digital current signal, and determining the X coordinate of the touch point after calculations of the first X side digital current signal and the second X side digital current signal have been carried out;
a Y coordinate determining device, receiving the first Y side digital current signal and the second Y side digital current signal, and determining the Y coordinate of the touch point after calculations of the first Y side digital current signal and the second Y side digital current signal have been carried out.
1 Assignment
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Accused Products
Abstract
A noise reducing device for a capacitive touch panel and a method of reducing noise for a capacitive touch panel are disclosed to solve problems related to noise generated by a conventional filter circuit and an integrating circuit or external noise. In the invention, at least one switch circuit is used so that the conventional filter circuit and integrating circuit used in the prior are omitted. Signals output from a current measurement circuit are transmitting to a control unit to calculate the location of a touch point, reducing any noise.
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Citations
70 Claims
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1. A sensing device for a capacitive touch panel, the capacitive touch panel being rectangular and having a transparent substrate and a sensing layer on the transparent substrate, the sensing layer being transparent and electrically conductive, the capacitive touch panel further having a first X side, a second X side, a first Y side and a second Y side, the sensing device comprising:
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a first X side switch circuit, respectively electronically connected to the first X side; a second X side switch circuit, respectively electronically connected to the second X side; a first Y side switch circuit, respectively electrically connected to the first Y side; a second Y side switch circuit, respectively electrically connected to the second Y side; a sensing source, providing a sensing signal to the first X side switch circuit, the second X side switch circuit, the first Y side switch circuit and the second Y side switch circuit; and a control circuit, receiving the sensing signal generated by the sensing source, the control circuit further comprising; a first current measurement circuit, receiving a first X side current signal generated by the first X side switch circuit or a first Y side current signal generated by the first Y side switch circuit; a second current measurement circuit, receiving a second X side current signal generated by the second X side switch circuit or a second Y side current signal generated by the second Y side switch circuit; a control unit, comprising; a first analogue/digital conversion circuit, converting a first X side analogue signal generated by the first X side current signal into a first X side digital signal, or converting a first Y side analogue signal generated by the first Y side current signal into a Y side digital signal; and a second analogue/digital conversion circuit, converting a second X side analogue signal generated by the second X side current signal into a second X side digital signal, or converting a second Y side analogue signal generated by the second Y side current signal into a second Y side digital signal; and a location determining unit, electrically connected to the first analogue/digital conversion circuit and the second analogue/digital conversion circuit, and comprising; an X coordinate determining device, receiving the first X side digital current signal and the second X side digital current signal, and determining the X coordinate of the touch point after calculations of the first X side digital current signal and the second X side digital current signal have been carried out; a Y coordinate determining device, receiving the first Y side digital current signal and the second Y side digital current signal, and determining the Y coordinate of the touch point after calculations of the first Y side digital current signal and the second Y side digital current signal have been carried out. - View Dependent Claims (2, 3, 4)
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5. A sensing device for a capacitive touch panel, the capacitive touch panel being rectangular and having a transparent substrate and a sensing layer on the transparent substrate, the sensing layer being transparent and electrically conductive, the capacitive touch panel further having a first X side, a second X side, a first Y side and a second Y side, the sensing device comprising:
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a first X side switch circuit, respectively electronically connected to the first X side; a second X side switch circuit, respectively electronically connected to the second X side; a first Y side switch circuit, respectively electrically connected to the first Y side; a second Y side switch circuit, respectively electrically connected to the second Y side; a sensing source, comprising a first sensing signal source and a second sensing signal source; and a control circuit, receiving at least one first sensing signal generated by the first sensing signal source and at least one second sensing signal generated by the second sensing signal source, the control circuit further comprising; a first current measurement circuit, receiving a first X side current signal generated by the first X side switch circuit or a first Y side current signal generated by the first Y side switch circuit; a second current measurement circuit, receiving a second X side current signal generated by the second X side switch circuit or a second Y side current signal generated by the second Y side switch circuit; a first sample and hold circuit, electrically connected to the first current measurement circuit to receive signal sampling, thereby reducing any noise generated by the first X side switch circuit or the first Y side switch circuit; a second sample and hold circuit, arranged between the first current measurement circuit and the second analogue/digital conversion circuit to receive the second X side current signal or the second Y side current signal for signal sampling, thereby reducing any noise generated by the second X side switch circuit or the second Y side switch circuit; an electronic switch, electrically connected to the first sample and hold circuit and the second sample and hold circuit to switch to one of them according to the received first sensing signal or the second sensing signal to obtain the first X side current signal and the first Y side current signal or the second X side current signal and the second Y side current signal; a control unit, comprising; a analogue/digital conversion circuit, electrically connected to the electronic switch to receive a first X side analogue signal generated by the first X side current signal, a first Y side analogue signal generated by the first Y side current signal, a second X side analogue signal generated by the second X side current signal and a second Y side analogue signal generated by the second Y side current signal, and correspondingly converting them into a first X side digital signal, a second X side digital signal, a first Y side digital signal and a second Y side digital signal; and a location determining unit, electrically connected to the analogue/digital conversion circuit, and comprising; an X coordinate determining device, determining the X coordinate of the touch point according to the first X side digital current signal and the second X side digital current signal; a Y coordinate determining device, determining the Y coordinate of the touch point according to the first Y side digital current signal and the second Y side digital current signal.
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6. A sensing method for a capacitive touch panel, the capacitive touch panel being rectangular and having a transparent substrate and a sensing layer on the transparent substrate, the sensing layer being transparent and electrically conductive, the capacitive touch panel further having a first X side, a second X side, a first Y side and a second Y side, the method comprising:
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providing a first sensing signal source and a second sensing signal source;
respectively transmitting the first sensing signal and the second sensing signal to the first X side, the first Y side, the second X side and the second Y side;
obtaining a first X side analogue current signal, a first Y side analogue current signal, a second X side analogue current signal and a second Y side analogue current signal;respectively converting the first X side analogue current signal, the first Y side analogue current signal, the second X side analogue current signal and the second Y side analogue current signal into a first side digital current signal, a first Y side analogue signal, a second X side digital current signal and a second Y side digital signal; and transmitting the first X side digital current signal, the first Y side digital current, the second X side digital current signal and the second Y side digital current signal to a location determining unit for calculating the X and Y coordinates of a touch point. - View Dependent Claims (7, 8, 9, 10)
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11. A sensing device for a capacitive touch panel, comprising:
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a sensing signal source, providing a sensing signal to a plurality of contacts of the capacitive touch panel; a plurality of connection circuits, each connection circuit connecting to at least one of the contacts; a plurality of digital synchronization circuits, each digital synchronization 10 circuit generating a digital signal from an analogue signal from one of the connection circuits, and all of the digital synchronization circuits receive the analogue signal simultaneously; and a location determining unit, calculating a coordinate according to a plurality of digital signals. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 46, 47)
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31. A sensing method of a capacitive touch panel, comprising:
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providing a sensing signal to a plurality of contacts of the capacitive touch panel; selectively connecting a plurality of connection circuits with at least one part of the contacts; selectively connecting a plurality of digital synchronization circuits with at least one part of the contacts; separately generating an analog signal according to the contact of each connection circuit; separately generating a digital signal according to whether each digital synchronization circuit has received the analog signal from one of connection circuits; and calculating a coordinate according to the digital signals. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 48, 49)
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50. A control unit of a capacitive touch panel, comprising:
a plurality of digital integration circuits, each the digital integration circuit comprising; an analogue/digital converter for converting a plurality of sampled analogue signals into a plurality of digital signals continuously when the analogue signal receives a signal source in an added cycle; an adder for generating an integration value according to the summary of the digital signals in the added cycle; and a coordinate calculation unit for calculating a coordinate according to the integration value. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61)
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62. A control unit of a capacitive touch panel, comprising:
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a plurality of digital integration circuits, each the digital integration circuits comprising; an analogue/digital converter for converting a plurality of sampled analogue signals into a plurality of digital signals continuously when the analogue signals receives one part of an analogue signal, each digital integration circuit receives a part of different analogue signal respectively; an adder for generating an integration value of the part of the analogue signal according to the summary of the digital signals; and a coordinate calculation unit for obtaining a summary value of the analogue signal from every part of the same analogue signal summary respectively and for calculating a coordinate according to the summary values. - View Dependent Claims (63, 64, 65, 66, 67, 68, 69, 70)
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Specification