Correction of parasitic capacitance effect in touch sensor panels

An apparatus for compensating for negative pixel effects on a touch sensor panel, comprising:

• a first stimulation signal source coupled to each of a plurality of drive lines having a first orientation on the touch sensor panel, the first stimulation signal sources configured for being activated to generate first measured pixel touch output values;
• a sense amplifier coupled to each of a plurality of sense lines having a second orientation different from the first orientation on the touch sensor panel, the sense amplifier including a second stimulation signal source coupled to an input of the sense amplifier, the second stimulation signal sources configured for being activated to generate second measured pixel touch output values;
• and
• a panel processor configured for calculating actual pixel touch output values from iterative use of the first measured pixel touch output values and an object-to-ground capacitance.

A system for compensating for negative pixel effects on a touch sensor panel, comprising:

• a touch sensor panel having a plurality of drive lines and a plurality of sense lines;
• a panel subsystem coupled to the touch sensor panel, the panel subsystem including
• driver logic coupled to the drive lines of the touch sensor panel, the driver logic configured for generating first stimulation signals, and
• sense channels coupled to the sense lines of the touch sensor panel, each sense channel including a sense amplifier having a second stimulation signal source coupled to an input of the sense amplifier, the sense channels configured for generating first measured pixel touch output values in response to the first stimulation signals from the driver logic and generating second measured pixel touch output values in response to second stimulation signals from the second stimulation signal sources;
• and
• a panel processor coupled to the panel subsystem and configured for calculating an object-to-ground capacitance associated with an object in contact with the touch sensor panel.

A mobile telephone including a touch sensor panel and configured to provide negative pixel compensation to the touch sensor panel, comprising:

• a first stimulation signal source coupled to each of a plurality of drive lines having a first orientation on the touch sensor panel, the first stimulation signal sources configured for being activated to generate first measured pixel touch output values;
• a sense amplifier coupled to each of a plurality of sense lines having a second orientation different from the first orientation on the touch sensor panel, the sense amplifier including a second stimulation signal source coupled to an input of the sense amplifier, the second stimulation signal sources configured for being activated to generate second measured pixel touch output values;
• and
• a panel processor configured for calculating actual pixel touch output values from iterative use of the first measured pixel touch output values and an object-to-ground capacitance.

A media player including a touch sensor panel and configured to provide negative pixel compensation to a touch sensor panel, comprising:

• the touch sensor panel having a plurality of drive lines and a plurality of sense lines;
• a panel subsystem coupled to the touch sensor panel, the panel subsystem including
• driver logic coupled to the drive lines of the touch sensor panel, the driver logic configured for generating first stimulation signals, and
• sense channels coupled to the sense lines of the touch sensor panel, each sense channel including a sense amplifier having a second stimulation signal source coupled to an input of the sense amplifier, the sense channels configured for generating first measured pixel touch output values in response to the first stimulation signals from the driver logic and generating second measured pixel touch output values in response to second stimulation signals from the second stimulation signal sources;
• and
• a panel processor coupled to the panel subsystem and configured for calculating an object-to-ground capacitance associated with an object in contact with the touch sensor panel.

A computing system including a touch sensor panel and configured to provide negative pixel compensation to the touch sensor panel, comprising:

• a first stimulation signal source coupled to each of a plurality of drive lines having a first orientation on the touch sensor panel, the first stimulation signal sources configured for being activated to generate first measured pixel touch output values;
• a sense amplifier coupled to each of a plurality of sense lines having a second orientation different from the first orientation on the touch sensor panel, the sense amplifier including a second stimulation signal source coupled to an input of the sense amplifier, the second stimulation signal sources configured for being activated to generate second measured pixel touch output values;
• and
• a panel processor configured for calculating actual pixel touch output values from iterative use of the first measured pixel touch output values and an object-to-ground capacitance.