Touch screen and method for compensating sensing capacitance variations and offset variations thereof
First Claim
1. A touch screen comprising:
- a touch panel having a plurality of driving lines and a plurality of sensing lines intersecting with the plurality of driving lines, respectively;
a driving unit configured to activate the driving lines sequentially;
an input unit configured to measure a sensing capacitance formed in a sensing line corresponding to an activated driving line;
a multiplexer configured to sequentially output the measured sensing capacitance;
an analog-to-digital converter configured to sample the measured sensing capacitance outputted from the multiplexer using an initial sensing capacitance as an offset and perform analog-to-digital conversion on the sampling result; and
a host processor configured to determine a touch event in response to the analog-to-digital conversion result,wherein the analog-to-digital conversion result corresponds to a difference between the measured sensing capacitance and the initial sensing capacitance.
1 Assignment
0 Petitions
Accused Products
Abstract
Provided are a touch screen and a method for compensating sensing capacitance variations and offset variations thereof. The touch screen includes: a touch panel where a plurality of driving lines and a plurality of sensing lines intersect and are wired; a driving unit for activating the driving lines sequentially; an input unit for measuring a sensing capacitance formed in a sensing line corresponding to an activated driving line; a multiplexer for serializing and outputting the measured sensing capacitance; an analog-to-digital converter for sampling the sensing capacitance outputted from the multiplexer by reflecting an initial sensing capacitance as an offset and performing analog-to-digital conversion for the sampling result; and a host processor for determining a touch event in response to the analog-to-digital conversion result.
4 Citations
20 Claims
-
1. A touch screen comprising:
-
a touch panel having a plurality of driving lines and a plurality of sensing lines intersecting with the plurality of driving lines, respectively; a driving unit configured to activate the driving lines sequentially; an input unit configured to measure a sensing capacitance formed in a sensing line corresponding to an activated driving line; a multiplexer configured to sequentially output the measured sensing capacitance; an analog-to-digital converter configured to sample the measured sensing capacitance outputted from the multiplexer using an initial sensing capacitance as an offset and perform analog-to-digital conversion on the sampling result; and a host processor configured to determine a touch event in response to the analog-to-digital conversion result, wherein the analog-to-digital conversion result corresponds to a difference between the measured sensing capacitance and the initial sensing capacitance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 17)
-
-
10. A method for compensating for sensing capacitance variations and offset variations of a touch screen, the method comprising:
-
storing first data measured from a sensing capacitor when the touch screen is not touched; and converting second data measured from the sensing capacitor when the touch panel is touched into digital data, wherein the first data is used to adjust a level of a sampling voltage of the second data when the second data is converted into the digital data, wherein the digital data corresponds to a difference between the first data and the second data, wherein the converting of the second data into the digital data comprises; selectively connecting a plurality of capacitors of a capacitor array to a ground or a first reference voltage based on the first data; sampling the second data in the capacitor array; and converting the sampling result into N-bit digital data, N being a positive integer, and wherein the converting of the sampling result into the N-bit digital data comprises; sequentially generating N scan signals corresponding to bits of the N-bit digital data, respectively; sequentially inputting voltages corresponding to the bits of the N-bit digital data, respectively, among the sampling result into a comparator; and determining each of the bits of the N-bit digital data by comparing a voltage inputted into the comparator with a second reference voltage. - View Dependent Claims (12, 13, 14, 15, 16, 18)
-
-
11. The method of claimer 10, wherein the sampling result is inputted into an inverting input of the comparator.
-
19. A method for compensating for sensing capacitance variations and offset variations of a touch screen, the method comprising:
-
storing first data measured from a sensing capacitor when the touch screen is not touched; and converting second data measured from the sensing capacitor when the touch panel is touched into digital data, wherein the first data is used to adjust a level of a sampling voltage of the second data when the second data is converted into the digital data, wherein the digital data corresponds to a difference between the first data and the second data, wherein the converting of the second data into the digital data comprises; selectively connecting a plurality of capacitors of a capacitor array to a ground or a first reference voltage based on the first data; sampling the second data in the capacitor array; and converting the sampling result into N-bit digital data, N being a positive integer, wherein the capacitor array samples a voltage corresponding to a difference between a second reference voltage and a compensation voltage, the compensation voltage corresponding to the first data, and wherein when the second reference voltage is VREF and bits of the first data are COMP1, COMP2, . . . , and COMPN, respectively, the compensation voltage VCOMP is determined as follows; - View Dependent Claims (20)
-
Specification