INTEGRATED DISPLAY AND TOUCH SCREEN

• US 20140139457A1
• Filed: 10/07/2013
• Published: 05/22/2014
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: HOTELLING, Steve Porter, Chen, Wei, Krah, Christoph Horst, Elias, John Greer, Yao, Wei Hsin, Zhong, John Z., Hodge, Andrew Bert, Land, Brian Richards, den Boer, Willem
• Granted Patent: US 9,268,429 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: 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 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• 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: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0478 related to liquid crystal pixels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Liquid crystal display (LCD) touch screens integrate touch sensing elements with display circuitry and may include in-plane-switching (IPS) LCDs. A method of operating the integrated touch sensing elements with the display circuitry includes dividing touch-sensing circuitry of the touch screen into a plurality of drive segments, each drive segment overlapping one or more display rows; updating the display at a predetermined refresh rate; stimulating the plurality of drive segments at a predetermined scan rate; and changing the sequence of stimulating the plurality of drive segments as required to prevent simultaneously stimulating a drive segment that overlaps a display row currently being updated.

Claims

1. A method of operating an integrated liquid crystal display touch screen whereby updating of the display can be done concurrently with touch scanning, the method comprising:

dividing touch-sensing circuitry of the touch screen into a plurality of drive segments,

each drive segment overlapping one or more display rows;

updating the display at a predetermined refresh rate;

stimulating the plurality of drive segments at a predetermined scan rate; and

changing the sequence of stimulating the plurality of drive segments as required to prevent simultaneously stimulating a drive segment that overlaps a display row currently being updated.

2. The method of claim 1 wherein the scan rate is the same as the refresh rate.

3. The method of claim 1 wherein the scan rate is an integer multiple of the refresh rate.

4. The method of claim 3 wherein the scan rate is twice the refresh rate.

5. The method of claim 1 further comprising changing the sequence of stimulating the plurality of drive segments as required to prevent concurrently stimulating a drive segment that is adjacent a display row currently being updated.

6. A method of manufacturing an integrated liquid crystal display touch screen, the method comprising:

processing a first substrate, wherein processing the first substrate comprises;

applying a first ITO layer to the first substrate;

etching the first ITO layer;

applying a second ITO layer;

processing a second substrate,

wherein processing the second substrate comprises;

forming one or more touch-sensing structures on the second substrate;

affixing the first substrate to the second substrate to form an LCD assembly; and

affixing one or more touch-sensing elements to the LCD assembly.

7. The method of claim 6 wherein the one or more touch-sensing structures on the second substrate comprise one or more drive circuits.

8. The method of claim 6 wherein the one or more touch-sensing structures on the second substrate comprise one or more sense circuits.

9. The method of claim 6 wherein the one or more touch-sensing elements affixed to the LCD assembly are selected from the group consisting of integrated circuits, flexible printed circuits, and discrete components.

10. The method of claim 6 wherein processing the first substrate further comprises patterning the second ITO layer photolithography.

11. The method of claim 6 wherein processing the first substrate further comprises etching the second ITO layer.

12. The method of claim 6 wherein processing the first substrate further comprises applying a third ITO layer.

13. The method of claim 12 wherein a resistance of the third ITO layer is reduced by adding metal traces aligned with a black matrix of the LCD.