RC matching in a touch screen

• US 10,345,972 B2
• Filed: 06/10/2016
• Issued: 07/09/2019
• Est. Priority Date: 05/23/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lee, Szu-Hsien, Yang, Byung Duk, Huang, Chun-Yao, Kim, Kyung-Wook, Chang, Shih-Chang
• Primary Examiner(s): Okebato, Sahlu
• Application Number:
  US15/179,763
• Publication Number:
  US 20160282997A1
• Time in Patent Office: 1,124 Days
• 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
• CPC Class Codes: Y10T 29/49107 Fuse making

Abstract

A touch screen. In some examples, the touch screen can comprise a first element coupled to a first sense connection, and a second element coupled to a second sense connection. In some examples, the first and second sense connections can be configured such that a load presented by the first sense connection and the first element is substantially equal to a load presented by the second sense connection and the second element. In some examples, the first and second sense connections can comprise detour routing configured such that a resistance of the first sense connection is substantially equal to a resistance of the second sense connection. In some examples, the first and second sense connections can be coupled to dummy routing configured such that a first capacitance presented by the first sense connection is substantially equal to a second capacitance presented by the second sense connection.

Claims

1. A touch screen comprising:

a first touch electrode coupled to a first sense connection at a first connection point, wherein the first sense connection comprises a plurality of conductive lines, and first subset of the plurality of conductive lines of the first sense connection are coupled to the first touch electrode at the first connection point; and

a second touch electrode coupled to a second sense connection at a second connection point, wherein the second sense connection comprises a plurality of conductive lines, and a second subset of the plurality of conductive lines of the second sense connection are coupled to the second touch electrode at the second connection point,

wherein;

the first sense connection comprises a first bridge at which a third subset of the conductive lines of the first sense connection are coupled in parallel, the third subset having a different number of conductive lines than the first subset, the first bridge disposed a first distance from the first connection point,

the second sense connection comprises a second bridge at which a fourth subset of the conductive lines of the second sense connection are coupled in parallel, the fourth subset having a different number of conductive lines than the second subset, the second bridge disposed a second distance, different from the first distance, from the second connection point, and

the first sense connection and the second sense connection have a same resistance.

2. The touch screen of claim 1, wherein:

the first sense connection and the second sense connection are configured to couple the first touch electrode and the second touch electrode, respectively, to a location on the touch screen, and

the first touch electrode is disposed a fifth distance from the location on the touch screen, and the second touch electrode is disposed a sixth distance from the location on the touch screen, the fifth distance being different than the sixth distance.

3. The touch screen of claim 2 wherein the location comprises a flex circuit connection area.

4. The touch screen of claim 1, further comprising first dummy routing coupled to the first sense connection and second dummy routing coupled to the second sense connection, wherein:

the first sense connection is configured to carry a signal between sense circuitry and the first touch electrode,

the first dummy routing is configured not to carry a signal between the sense circuitry and the first touch electrode,

the second sense connection is configured to carry a signal between the sense circuitry and the second touch electrode, and

the second dummy routing is configured not to carry a signal between the sense circuitry and the second touch electrode.

5. The touch screen of claim 4, wherein a number of conductive lines in the first dummy routing is equal to a number of conductive lines of the first sense connection, and a number of conductive lines has a number of conductive lines in the second dummy routing is equal to a number of conductive lines of the second sense connection.

6. The touch screen of claim 1, wherein the first bridge is disposed on a signal path between a flex circuit of the touch screen and the first touch electrode.

7. The touch screen of claim 1, wherein:

the touch screen comprises a self-capacitance touch screen, and

the first and second touch electrodes are distinct touch pixel electrodes of the self-capacitance touch screen.

8. The touch screen of claim 1, wherein the first touch electrode and the second touch electrode overlap a same number of conductive lines of sense connections coupled to respective touch electrodes on the touch screen.

9. The touch screen of claim 1, wherein:

the first sense connection and the second sense connection are configured to couple the first touch electrode and the second touch electrode, respectively, to a location on the touch screen, and

the first bridge is disposed a seventh distance from the location on the touch screen, and the second bridge is disposed an eighth distance from the location on the touch screen, the seventh distance being different than the eighth distance.

10. The touch screen of claim 1, wherein the first sense connection and the second sense connection have a same capacitance.

11. The touch screen of claim 1, wherein:

the first sense connection and the second sense connection are configured to couple the first touch electrode and the second touch electrode, respectively, to a location on the touch screen,

the first sense connection includes a first portion between the first bridge and the location,

the second sense connection includes a second portion between the second bridge and the location, and

the first portion and the second portion have different resistances.

12. The touch screen of claim 1, wherein:

the conductive lines coupled at the first bridge comprise one or more continuous conductive lines also coupled at the first connection point; and

the conductive lines coupled at the second bridge comprise one or more continuous conductive lines also coupled at the second connection point.

13. A method for sensing touch at a touch screen, the method comprising:

sensing touch at a first touch electrode coupled to a first sense connection at a first connection point, wherein the first sense connection comprises a plurality of conductive lines, and first subset of the plurality of conductive lines of the first sense connection are coupled to the first touch electrode at the first connection point; and

sensing touch at a second touch electrode coupled to a second sense connection at a second connection point, wherein the second sense connection comprises a plurality of conductive lines, and a second subset of the plurality of conductive lines of the second sense connection are coupled to the second touch electrode at the second connection point,

wherein;

the first sense connection comprises a first bridge at which a third subset of the conductive lines of the first sense connection are coupled in parallel, the third subset having a different number of conductive lines than the first subset, the first bridge disposed a first distance from the first connection point,

the second sense connection comprises a second bridge at which a fourth subset of the conductive lines of the second sense connection are coupled in parallel, the fourth subset having a different number of conductive lines than the second subset, the second bridge disposed a second distance, different from the first distance, from the second connection point, and

the first sense connection and the second sense connection have a same resistance.

14. The method of claim 13, wherein the touch screen further comprises first dummy routing coupled to the first sense connection and second dummy routing coupled to the second sense connection, and the method further comprises:

carrying, with the first sense connection, a signal between sense circuitry and the first touch electrode,

not carrying, with the first dummy routing, a signal between the sense circuitry and the first touch electrode,

carrying, with the second sense connection, a signal between the sense circuitry and the second touch electrode, and

not carrying, with the second dummy routing, a signal between the sense circuitry and the second touch electrode.

15. The method of claim 13, wherein the first touch electrode and the second touch electrode overlap a same number of conductive lines of sense connections coupled to respective touch electrodes on the touch screen.

16. The method of claim 13, wherein the first sense connection and the second sense connection have a same capacitance.

17. The method of claim 13, wherein:

the first sense connection and the second sense connection are configured to couple the first touch electrode and the second touch electrode, respectively, to a location on the touch screen,

the first sense connection includes a first portion between the first bridge and the location,

the second sense connection includes a second portion between the second bridge and the location, and

the first portion and the second portion have different resistances.

18. The method of claim 13, wherein:

the conductive lines coupled at the first bridge comprise one or more continuous conductive lines coupled at the first connection point; and

the conductive lines coupled at the second bridge comprise one or more continuous conductive lines coupled at the second connection point.