Touch Screen Border Regions

• US 20110074705A1
• Filed: 12/11/2009
• Published: 03/31/2011
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: YOUSEFPOR, Marduke, White, Kevin J., Hotelling, Steven Porter, Chang, Shih Chang
• Granted Patent: US 8,982,058 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G06F 1/16 Constructional details or arrangements
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

Touch screens with more compact border regions can include an active area that includes touch sensing circuitry including drive lines, and a border region around the active area. The border region can include an area of sealant deposited on conductive lines, and transistor circuitry, such as gate drivers, between the active area and the sealant. The conductive lines can extend from the sealant to the active area without electrically connecting to the transistor circuitry. The conductive lines can have equal impedances and can connect the drive lines to a touch controller off of the touch screen. A set of drive signal characteristics for the drive lines can be obtained by determining a transfer function associated with each drive line, obtaining an inverse of each transfer function, and applying a set of individual sense signal characteristics to the inverse transfer functions to obtain the corresponding set of drive signal characteristics.

Claims

1. A method of forming a touch screen, comprising:

forming transistor circuitry in an unconstrained region within a border region bordering an active area of the touch screen, the unconstrained region between the active area and a restricted structure region within the border region; and

forming conductive lines in the border region, the conductive lines including a first portion formed in the restricted structure region and a second portion extending to the active area without electrically connecting to the transistor circuitry.

2. The method of claim 1, wherein the restricted structure region is a sealant region and forming the conductive lines includes forming the first portion of the conductive lines as a perforated structure.

3. The method of claim 1, wherein forming the transistor circuitry includes forming gate drivers that drive gates of display circuitry in the active area.

4. The method of claim 3, wherein forming the conductive lines includes forming the second portion of the conductive lines to electrically connect with touch sensing circuitry in the active area.

5. A touch screen comprising:

an active area that senses touch; and

a border region that borders the active area, the border region including

conductive lines having first and second portions,

sealant deposited on the first portion of the conductive lines, and

transistor circuitry between the active area and the sealant,

wherein the second portion of the conductive lines extends from the sealant to the active area while remaining electrically disconnected from the transistor circuitry.

6. The touch screen of claim 5, wherein the first portion of the conductive lines includes perforated material.

7. The touch screen of claim 5, wherein the transistor circuitry includes gate drivers that drive gates of display circuitry in the active area.

8. The touch screen of claim 5, wherein the conductive lines are electrically connected to touch sensing circuitry in the active area.

19. The touch screen of claim 5, the touch screen incorporated in a touch screen device that further comprises:

a processor; and

a memory.

20. The touch screen of claim 19, wherein the touch screen device is one of a digital media player, a mobile telephone, and a personal computer.

9. A method of determining a set of drive signal characteristics for a touch screen including a plurality of drive lines and a sense line, the method comprising:

determining a transfer function associated with each drive line;

obtaining an inverse of each transfer function;

applying a set of individual sense signal characteristics to the inverse transfer functions to obtain a corresponding set of drive signal characteristics; and

storing the set of drive signal characteristics in a computer-readable storage medium.

10. The method of claim 9, wherein each transfer function includes a transfer function associated with one of the drive lines and a corresponding gate line of the touch screen.

11. The method of claim 9, wherein the individual sense signal characteristics include a pair of individual sense signal characteristics with the same magnitude and frequency and 180 degrees out of phase.

12. A touch screen comprising:

an active area that senses touch and displays an image;

a plurality of gate drivers in a border region of the touch screen;

a display driver; and

a system of conductive paths, each conductive path connecting a gate driver and the display driver, wherein the impedances of the conductive paths are substantially the same.

13. The touch screen of claim 12, wherein the system of conductive paths includes a common node that is included in all of the conductive paths.

14. The touch screen of claim 13, wherein the system of conductive paths further includes another node that is included in two or more of the conductive paths, but less than all of the conductive paths.

15. The touch screen of claim 14, wherein the system of conductive paths includes a binary tree structure having a plurality of branches of substantially the same impedance.

16. The touch screen of claim 12, wherein the conductive paths are substantially the same length.

17. The touch screen of claim 12, wherein the conductive paths include conductive lines, and wherein a conductive line of one of the conductive paths has a different width than a conductive line of another of the conductive paths.

21. The touch screen of claim 12, the touch screen incorporated in a touch screen device that further comprises:

a processor; and

a memory.

22. The touch screen of claim 21, wherein the touch screen device is one of a digital media player, a mobile telephone, and a personal computer.

18. A touch screen including an active area, the active area including a plurality of display pixels and touch sensing circuitry, the touch screen comprising:

a plurality of gate drivers including a first group of gate drivers disposed one side of the active area, the first group of gate drivers driving some of the display pixels, and a second group of gate drivers disposed on an opposing side of the active area, the second group of gate drivers driving other of the display pixels; and

conductive lines connected to the touch sensing circuitry in the active area, each conductive line extending from the active area through a gap between an adjacent pair of gate drivers.

23. The touch screen of claim 18, the touch screen incorporated in a touch screen device that further comprises:

a processor; and

a memory.

24. The touch screen of claim 23, wherein the touch screen device is one of a digital media player, a mobile telephone, and a personal computer.