Patent ID: 8890820

Claim:
A control apparatus which controls a touch panel comprising a first resistive film comprising a first terminal and a second terminal on respective opposite end sides and a second resistive film comprising a third terminal and a fourth terminal on respective opposite end sides which are orthogonal to the opposite end sides of the first resistive film, the first and second resistive films being laid on top of each other with a gap between the resistive films in such a manner that the resistive films come into contact with each other at a point at which the touch panel has been touched, the apparatus comprising: an application unit configured to apply a voltage between the first terminal and the second terminal at a first timing; a measurement unit configured to measure a voltage of each of the third and fourth terminals at the first timing; and a calculation unit configured to derive a relative positional relationship between two points at which the touch panel has been touched based on the voltages of the third and fourth terminals measured at the first timing; wherein the relative positional relationship includes a first relationship in which a straight line joining coordinates of the two points slopes upwards when going from left to right and a second relationship in which the straight line joining the coordinates of the two points slopes downwards when going from left to right; the calculation unit derives the relative positional relationship between the two points based on a magnitude relationship between the voltages of the third and fourth terminals measured at the first timing; the application unit further applies a voltage between the third terminal and the fourth terminal at a second timing; the measurement unit further measures the voltage of at least one of the first and second terminals at the first timing, and measures the voltage of at least one of the third and fourth terminals, the voltage of the first terminal, and the voltage of the second terminal at the second timing; and the calculation unit further calculates central coordinates of the two points and at least one of a first inter-coordinates distance between the two points and a second inter-coordinates distance between the central coordinates and each of the two points, based on the voltages of the terminals measured at the first and second timings, and calculates the coordinates of the two points based on the central coordinates of the two points, at least one of the first and second inter-coordinates distances, and the relative positional relationship between the two points.