Patent ID: 7236160

Claim:
A touch panel driving apparatus, comprising: a first resistive layer having first and second electrodes formed facing each other along opposing edges of the first resistive layer in a first direction; a second resistive layer having third and fourth electrodes formed facing each other along opposing edges of the second resistive layer in a second direction, wherein the second resistive layer faces the first resistive layer and is separated from the first resistive layer with a gap therebetween; a first variable resistor for variably reducing a high potential voltage supplied from a high potential voltage source; a second variable resistor for variably reducing a high potential voltage supplied from the high potential voltage source; a high potential controller for selectively connecting the first electrode to the high potential voltage source via the first variable resistor and for selectively connecting the third electrode to the high potential voltage source via the second variable resistor; a low potential controller for selectively connecting one of the second and fourth electrodes to a low potential voltage; an analog to digital converter for converting voltages at the second and fourth electrodes into digital data; and a controller for controlling the high potential controller and the low potential controller, wherein the resistance value of the first variable resistor is set based on a first voltage between the first and second electrodes, and the resistance value of the second variable resistor is set based on a second voltage between the third and fourth electrodes.