Projection scan multi-touch sensor array

A method for forming a single-surface touch sensor panel, comprising:

• forming each of a plurality of distributed resistor-capacitor (RC) lines by alternating connected transistors and metal pads on a single surface of a sensor panel substrate, each transistor having drain and source terminals connected to adjacent metal pads;
• arranging the plurality of distributed RC lines in an array of rows and columns;
• connecting a column enable line to a gate terminal of every transistor in the distributed RC lines oriented in a column;
• and
• connecting a row enable line to a gate terminal of every transistor in the distributed RC lines oriented in a row.

A method for detecting one or more touches on a single-surface touch sensor panel having columns and rows of distributed resistor-capacitor (RC) lines formed from alternating transistors and metal pads on a single surface of a sensor panel substrate, comprising:

• for every row, enabling the transistors in that row while disabling the transistors in all columns, sending a pulse left-to-right and then right-to-left through the row, measuring left-to-right and right-to-left pulse travel times through the row, and computing an equalized pulse travel time for that row as the sum of the left-to-right and right-to-left travel times;
• for every column, enabling the transistors in that column while disabling the transistors in all rows, sending a pulse top-to-bottom and then bottom-to-top through the column, measuring top-to-bottom and bottom-to-top pulse travel times through the column, and computing an equalized pulse travel time for that column as the sum of the top-to-bottom and bottom-to-top travel times;
• and
• identifying the rows and columns having touches as those rows and columns having equalized pulse travel times greater than a no-touch equalized pulse travel time.

A system for detecting one or more touches on a single-surface touch sensor panel having columns and rows of distributed resistor-capacitor (RC) lines formed from alternating transistors and metal pads on a single surface of a sensor panel substrate, the system including a processor programmed for causing performance of a method comprising:

• for every row, enabling the transistors in that row while disabling the transistors in all columns, sending a pulse left-to-right and then right-to-left through the row, measuring left-to-right and right-to-left pulse travel times through the row, and computing an equalized pulse travel time for that row as the sum of the left-to-right and right-to-left travel times;
• for every column, enabling the transistors in that column while disabling the transistors in all rows, sending a pulse top-to-bottom and then bottom-to-top through the column, measuring top-to-bottom and bottom-to-top pulse travel times through the column, and computing an equalized pulse travel time for that column as the sum of the top-to-bottom and bottom-to-top travel times;
• and
• identifying the rows and columns having touches as those rows and columns having equalized pulse travel times greater than a no-touch equalized pulse travel time.

An apparatus for detecting one or more touches on a single-surface touch sensor panel having columns and rows of distributed resistor-capacitor (RC) lines formed from alternating transistors and metal pads on a single surface of a sensor panel substrate, comprising:

• means for enabling the transistors in every row while disabling the transistors in all columns, means for sending a pulse left-to-right and then right-to-left through each row, means for measuring left-to-right and right-to-left pulse travel times through each row, and means for computing an equalized pulse travel time for each row as the sum of the left-to-right and right-to-left travel times for each row;
• means for enabling the transistors in every column while disabling the transistors in all rows, means for sending a pulse top-to-bottom and then bottom-to-top through each column, means for measuring top-to-bottom and bottom-to-top pulse travel times through each column, and means for computing an equalized pulse travel time for each column as the sum of the top-to-bottom and bottom-to-top travel times for each column;
• and
• means for identifying the rows and columns having touches as those rows and columns having equalized pulse travel times greater than a no-touch equalized pulse travel time.

A mobile telephone including a single-surface touch sensor panel, the single-surface touch sensor panel comprising:

• a plurality of distributed resistor-capacitor (RC) lines arranged in an array of rows and columns, the distributed RC lines including alternating connected transistors and metal pads formed on a single surface of a sensor panel substrate, each transistor having drain and source terminals connected to adjacent metal pads;
• a column enable line connected to a gate terminal of every transistor in the distributed RC lines oriented in a column;
• and
• a row enable line connected to a gate terminal of every transistor in the distributed RC lines oriented in a row.

A digital audio player including a single-surface touch sensor panel, the single-surface touch sensor panel comprising:

• a plurality of distributed resistor-capacitor (RC) lines arranged in an array of rows and columns, the distributed RC lines including alternating connected transistors and metal pads formed on a single surface of a sensor panel substrate, each transistor having drain and source terminals connected to adjacent metal pads;
• a column enable line connected to a gate terminal of every transistor in the distributed RC lines oriented in a column;
• and
• a row enable line connected to a gate terminal of every transistor in the distributed RC lines oriented in a row.