TOUCH PANEL WITH REDUCED CHARGE TIME
First Claim
1. A touch panel, comprising:
- a sensing region having an equivalent capacitance at a predetermined location and including;
a first end for receiving a pulse signal;
a second end for providing a first signal before the touch panel receives a touch signal, and for providing a second signal after the touch panel receives the touch signal; and
a touch detection circuit comprising;
a storage unit for providing a third signal by storing energy corresponding to the first signal, or for providing a fourth signal by storing energy corresponding to the second signal; and
a precision rectifier circuit having an input end coupled to the predetermined location and an output end coupled to the storage unit for controlling a signal transmission path between the predetermined location and the storage unit according to voltage levels of the input and output ends in a charge period of the storage unit.
1 Assignment
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Accused Products
Abstract
A touch panel includes a sensing region, a storage unit, a precision rectifier circuit and a comparing circuit. There exists an equivalent capacitance at a predetermined location in the sensing region. At the predetermined location, the sensing region can provide a first signal before a touch action occurs and a second signal after the touch action occurs. The precision rectifier circuit can control the signal transmission path between the predetermined location and the storage unit. After being charged by the first and second signals, the storage unit can respectively provide corresponding third and fourth signals. The comparing circuit can thus determine whether the touch action occurs at the predetermined location according to the third and fourth signals.
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Citations
20 Claims
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1. A touch panel, comprising:
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a sensing region having an equivalent capacitance at a predetermined location and including; a first end for receiving a pulse signal; a second end for providing a first signal before the touch panel receives a touch signal, and for providing a second signal after the touch panel receives the touch signal; and a touch detection circuit comprising; a storage unit for providing a third signal by storing energy corresponding to the first signal, or for providing a fourth signal by storing energy corresponding to the second signal; and a precision rectifier circuit having an input end coupled to the predetermined location and an output end coupled to the storage unit for controlling a signal transmission path between the predetermined location and the storage unit according to voltage levels of the input and output ends in a charge period of the storage unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A touch panel comprising:
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a sensing region having an equivalent capacitance at a predetermined location and including; a first end for receiving a pulse signal; a second end for providing a first signal before the touch panel receives a touch signal and for providing a second signal after the touch panel receives the touch signal; and a touch detection circuit comprising; a storage unit for providing a third signal by storing energy corresponding to the first signal, or for providing a fourth signal by storing energy corresponding to the second signal; and a precision rectifier circuit comprising; an input end coupled to the predetermined location; an output end coupled to the storage unit; and an operational amplifier including; an output end coupled to the output end of the precision rectifier circuit; a first input end coupled to the input end of the precision rectifier circuit; and a second input end coupled to the output end of the operational amplifier. - View Dependent Claims (14, 15)
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16. A method for determining where a touch signal occurs, comprising:
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providing a storage unit; providing a pulse signal for charging a sensing region at a predetermined location having an equivalent capacitance; providing a precision rectifier circuit for controlling a signal transmission path between the predetermined location and the storage unit, wherein the precision rectifier circuit includes an input end coupled to the predetermined location and an output end coupled to the storage unit; turning on the precision rectifier circuit for charging the storage unit when the precision rectifier circuit has a higher voltage level at the input end than at the output end during a charge period of the storage unit; and turning off the precision rectifier circuit when the precision rectifier circuit does not have a higher voltage level at the input end than at the output end during the charge period of the storage unit. - View Dependent Claims (17, 18, 19, 20)
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Specification