Active integrated touch/display

• US 10,126,850 B2
• Filed: 12/13/2013
• Issued: 11/13/2018
• Est. Priority Date: 08/16/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Yousefpor, Marduke
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): Gupta, Parul
• Application Number:
  US14/106,283
• Publication Number:
  US 20150049045A1
• Time in Patent Office: 1,796 Days
• Field of Search: None
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

An integrated touch sensitive display is provided. The integrated touch sensitive display can include rows and columns of touch electrodes. Various modulation techniques can be applied to one or more of the touch electrodes to allow sense circuitry to individually measure a capacitance associated with each of the touch electrodes. The capacitances can be used to determine a location and/or amount of touch or hover events at or near the integrated touch sensitive display.

Claims

1. A touch sensor panel comprising

a plurality of touch electrodes located in a plurality of regions of the touch sensor panel, wherein:

each of the plurality of touch electrodes is;

located in a respective region of the plurality of regions that corresponds to the respective touch electrode, and

associated with respective circuitry located in the respective region of the touch sensor panel,

the respective circuitry is configured to, in response to receiving at the respective circuitry a code sequence signal, couple in the respective region of the touch sensor panel an associated touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal, and

each respective circuitry is configured to receive a different code sequence signal, wherein sense circuitry is operable to generate a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source.

2. The touch sensor panel of claim 1, further comprising demodulation circuitry operable to demodulate the current sense signal to determine a capacitance at a touch electrode of the plurality of touch electrodes based on a code sequence signal received by respective circuitry associated with the touch electrode of the plurality of touch electrodes.

3. The touch sensor panel of claim 1, wherein code sequence signals received by respective circuitry associated with each of the plurality of touch electrodes comprise the same sequence of values, and wherein each of the code sequence signals received by respective circuitry associated with the plurality of touch electrodes has a different phase offset.

4. The touch sensor panel of claim 1, wherein code sequence signals received by respective circuitry associated with the plurality of touch electrodes each comprise a pseudo inverse code or a Kasami code.

5. The touch sensor panel of claim 1, wherein a length each of the code sequence signals received by respective circuitry associated with the plurality of touch electrodes is greater than or equal to a number of touch electrodes in the plurality of touch electrodes.

6. The touch sensor panel of claim 1, wherein respective circuitry associated with each of the plurality of touch electrodes comprises a latch coupled to receive a code sequence signal associated with the touch electrode.

7. The touch sensor panel of claim 6, wherein the touch electrodes are arranged in rows and columns, and wherein latches of respective circuitry associated with touch electrodes in the same column are coupled in series.

8. The touch sensor panel of claim 1, wherein:

the respective circuitry associated with a touch electrode of the plurality of touch electrodes comprises a transmission gate,

the plurality of touch electrodes, including other touch electrodes, are arranged in rows and columns,

transmission gates of respective circuitry associated with touch electrodes in the same row are operable to couple their associated touch electrode to receive either a first stimulation signal from a first bus, coupled to the first voltage source, of the row or a second stimulation signal from a second bus, coupled to the second voltage source, of the row based on the code sequence signal,

transmission gates of respective circuitry associated with touch electrodes in the same column are coupled to receive the same code sequence signal; and

transmission gates of respective circuitry associated with touch electrodes in each row are coupled to receive a different code sequence signal.

9. The touch sensor panel of claim 8, further comprising sense and demodulation circuitry operable to detect a touch or hover event at a touch electrode in a particular row and in a particular column based at least on a code sequence signal received by respective circuitry associated with the touch electrode in the particular row and in the particular column and a difference between a first current through a first bus for the particular row and a second current through a second bus for the particular row.

10. The touch sensor panel of claim 9, wherein detecting a touch or hover event at the touch electrode in the particular row and in the particular column comprises multiplying the code sequence signal received by respective circuitry associated with the touch electrode in the particular row and in the particular column by the difference between the first current and the second current.

11. The touch sensor panel of claim 8, wherein a length of each of the code sequence signals is greater than or equal to a number of columns of touch electrodes.

12. The touch sensor panel of claim 8, wherein a first stimulation signal for a row is generated by a first stimulation signal generator, and wherein a second stimulation signal for the row is generated by a second stimulation signal generator.

13. The touch sensor panel of claim 12, wherein the first stimulation signal for the row and the second stimulation signal for the row are 180-degrees out of phase from each other.

14. The touch sensor panel of claim 8, wherein a first stimulation signal for a row is generated by a stimulation signal generator, and wherein a second stimulation signal for the row is generated by the stimulation signal generator.

15. A method comprising:

receiving, at a respective circuitry, a code sequence signal, wherein;

the respective circuitry is located in a respective region of a plurality of regions of the touch sensor panel that corresponds to a respective touch electrode of a plurality of touch electrodes of the touch sensor panel, and

the respective touch electrode is located in the respective region of the plurality of regions that corresponds to the respective touch electrode and is associated with the respective circuitry;

in response to receiving the code sequence signal, coupling in the respective region of the touch sensor panel the respective touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal; and

generating a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source.

16. An electronic device comprising:

a touch sensor panel having a plurality of touch electrodes located in a plurality of regions of the touch sensor panel, wherein;

each of the plurality of touch electrodes is;

located in a respective region of the plurality of regions that corresponds to the respective touch electrode, and

associated with respective circuitry located in the respective region of the touch sensor panel,

the respective circuitry is configured to, in response to receiving at the respective circuitry a code sequence signal, couple in the respective region of the touch sensor panel an associated touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal, and

each respective circuitry is configured to receive a different code sequence signal; and

sense circuitry operable to generate a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source.