Capacitance sensor, sense method, and manufacturing method
A touch screen may include pixel elements formed in a display substrate that are spaced from one another by an element spacing. A plurality of capacitance sense pads may be formed from a same conductive transparent layer in an array over the display substrate. Each sense pad may be separated from an adjacent sense pad by a pad spacing aligned within element spacing for a uniform light path for the pixel elements.
1. A touch screen contact position determination method, comprising:
detecting a change in capacitance at an intersection of at least two groups of sense pads disposed in different diagonal directions with respect to orthogonal directions of a touch screen area;
translating a point of intersection of the two groups of sense pads into coordinates of the orthogonal directions, wherein each group of sense pads has a first intercept value and a second intercept value, the first intercept value corresponding to a position where the diagonal of the group of sense pads intersects a first axis of the orthogonal directions, and the second intercept value corresponding to a position where the diagonal of the group of sense pads intersects a second axis of the orthogonal directions; and
translating the point of intersection includes one arithmetic operation between the first intercept values and one arithmetic operation between the second intercept values of the intersecting sense pad groups.
2. The method of claim 1 , wherein:
the arithmetic operation includes a subtraction operation.
3. The method of claim 1 , wherein:
each first intercept value is a coordinate value that is about one half of the coordinate where the diagonal intersects the first axis, and
each second intercept value is a coordinate value that is about one half of the coordinate where the diagonal intersects the second.
4. The method of claim 1 , wherein:
detecting a change in capacitance at an intersection of two groups of sense pads includes
activating each of a plurality of first groups of sense pads, each first group of sense pads having diagonals parallel to one another,
activating each of a plurality of second groups of sense pads, each second group of sense pads having diagonals parallel to one another but not parallel to the diagonals of the first groups of sense pads.
5. The method of claim 1 , further including:
transmitting light through the sense pads with a display having pixel elements arranged in an array that extends in the orthogonal directions,
the pixel elements comprising pixels having positions indicated by the coordinates of the orthogonal direction.