Integrated touch screen

• US 8,711,292 B2
• Filed: 03/16/2012
• Issued: 04/29/2014
• Est. Priority Date: 11/22/2011
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Guard, David Brent, Yilmaz, Esat
• Primary Examiner(s): CALEY, MICHAEL H
• Application Number:
  US13/422,410
• Publication Number:
  US 20130127776A1
• Time in Patent Office: 774 Days
• Field of Search: 349/12
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/1343 Electrodes reflective electrodes G02F1/133553
• CPC Class Codes: G06F 1/1652 the display being flexible, e.g. mimicking a sheet of paper, or rollable
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• 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 3/0445 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: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

In one embodiment, an apparatus includes a display stack for a touch-sensitive screen. The display stack comprises a plurality of layers in which a top layer comprises a substantially transparent cover layer. The display stack is configured to display a color image. The apparatus also includes a touch sensor provided within the display stack. The touch sensor comprises a plurality of first conductive electrodes contacting a layer of a subset of the plurality of layers of the display stack. The subset of the plurality of layers is below the substantially transparent cover layer. The touch sensor also includes a plurality of second conductive electrodes contacting a layer of the subset of the plurality of layers.

Claims

1. An apparatus comprising:

a display stack for a touch-sensitive screen, the display stack comprising a plurality of layers in which a top layer comprises a substantially transparent cover layer, the plurality of layers further comprising a first polarizer that is below the substantially transparent cover layer and a second polarizer that is below the substantially transparent cover layer and a liquid crystal layer, the display stack being configured to display a color image; and

a touch sensor within the display stack, the touch sensor comprising;

a plurality of first conductive electrodes contacting a layer of a subset of the plurality of layers, the subset being below the substantially transparent cover layer; and

a plurality of second conductive electrodes contacting the layer of the subset of the plurality of layers;

wherein the plurality of first conductive electrodes and the plurality of second conductive electrodes are located between the first polarizer and the second polarizer;

wherein the display stack is devoid of a polarizing layer between the first and second polarizers;

wherein the plurality of first conductive electrodes and the plurality of second conductive electrodes are also in contact with the first polarizer; and

wherein;

the plurality of first conductive electrodes comprise a plurality of drive electrodes;

the plurality of second conductive electrodes comprise a plurality of sense electrodes; and

the plurality of drive electrodes and the plurality of sense electrodes are also in contact with a same side of the first polarizer.

2. The apparatus of claim 1, wherein:

the display stack further comprises a color filter layer that is below the substantially transparent cover layer; and

the subset of the plurality of layers is between the substantially transparent cover layer and the color filter layer.

3. The apparatus of claim 1, wherein:

the display stack further comprises a color filter layer that is below the substantially transparent cover layer; and

the subset of the plurality of layers is below both the substantially transparent cover layer and the color filter layer.

4. The apparatus of claim 1, wherein the subset of the plurality of layers comprises a layer of non-birefringent material.

5. The apparatus of claim 1, wherein the display stack is a liquid crystal display stack.

6. The apparatus of claim 1, wherein the plurality of first conductive electrodes and the plurality of second conductive electrodes comprise fine line metal electrodes.

7. The apparatus of claim 1, wherein:

the subset of the plurality of layers comprises one layer; and

the plurality of first conductive electrodes and the plurality of second conductive electrodes contact a same side of the one layer.

8. The apparatus of claim 1, wherein the display stack comprises a flexible display stack and the touch sensor comprises a flexible touch sensor.

9. The apparatus of claim 1, wherein the display stack with the touch sensor provided therein is substantially free of air gaps.

10. An apparatus, comprising:

a first polarizer disposed as a lower layer of a display stack for a touch-sensitive screen, the first polarizer being configured to polarize light from a light source prior to that light reaching a liquid crystal layer of the display stack, the liquid crystal layer located above the first polarizer in the display stack;

a substantially transparent cover layer disposed as a top layer of the display stack, the substantially transparent cover layer being configured to receive a touch input;

a second polarizer disposed between the first polarizer and the substantially transparent cover layer;

a touch sensor located in the display stack between the first polarizer and the cover layer;

wherein a plurality of electrodes of the touch sensor are located between the first polarizer and the second polarizer;

wherein the display stack is devoid of a polarizing layer between the first and second polarizers;

wherein the plurality of electrodes of the touch sensor are in contact with the second polarizer; and

wherein;

the plurality of electrodes of the touch sensor comprise a plurality of drive electrodes and a plurality of sense electrodes; and

the plurality of drive electrodes and the plurality of sense electrodes are also in contact with a same side of the second polarizer.

11. The apparatus of claim 10, wherein the layer of the display stack on which the plurality of electrodes of the touch sensor are located comprises a layer of non-birefringent material.