Plastic film and touch sensor

• US 9,599,451 B2
• Filed: 07/11/2012
• Issued: 03/21/2017
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: PolyIC GmbH & Co. KG (Leonhard KURZ Stiftung & Company KG)
• Original Assignee: PolyIC GmbH & Co. KG (Leonhard KURZ Stiftung & Company KG)
• Inventors: Ullmann, Andreas, Fix, Walter, Laus, Norbert, Katschorek, Haymo
• Primary Examiner(s): Le, Son
• Assistant Examiner(s): FORTICH, ALVARO E
• Application Number:
  US14/241,695
• Publication Number:
  US 20140218053A1
• Time in Patent Office: 1,714 Days
• US Class Current: 1/1
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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

Abstract

Disclosed is a plastic film and to a touch module produced therefrom. The module is constructed from two conductive layers with an insulation layer in between, as are used in capacitive touch pads and/or touch screens, for example. The problem of connecting the respective x or y sensors across two planes in a cost-effective manner employs foldable sensor planes in the plastic film suitable for mass production. The connections and conductor tracks are concentrated on one plane on a sensor side wherein the sensor planes are arranged on flexible materials. The registering of the two planes relative to each other is simplified via a secure mechanical connection of the two planes via a fold in the film.

Claims

1. A capacitive touch sensor comprising:

an electrically insulating plastic film which has at least three areas, at least a first and second transparent area, in which the plastic film has strip conductors at least on one side, wherein the strip conductors of the first transparent area are aligned transverse to the strip conductors of the second transparent area, with the result that, when the plastic film is folded together along a fold line, the strip conductors in the first and second areas form a touch sensor field comprising a touch detecting network of overlying crossover points, and the third area is arranged between the first and the second transparent areas and which third area has the fold line and connection tracks for connecting the strip conductors of the first and/or second transparent areas;

wherein the first and second transparent areas are connected to each other via a transparent and electronically insulating layer by the fold in the plastic film along the fold line;

wherein connections of the strip conductors of the two transparent conductive areas normally coplanar are brought together in an overlying arrangement via the third area comprising the fold line, in that the electrically insulating layer consists of an optical clear adhesive (OCA) forming a capacitive touch sensor of the overlying strip conductors, and in that in the first and/or second transparent area the strip conductors are formed as conductive areas which in each case form the detecting network of conductive tracks each of which with a width smaller than/equal to 20 μ

m, wherein the conductive tracks are arranged at a distance from each other which allows the respective network to appear transparent for the human eye; and

a carrier with conductive material within the transparent conductive areas, wherein the coverage of the carrier with conductive material within the transparent conductive areas amounts to 20% of the surface area or less;

a plurality of the conductive tracks inside the networks are arranged such that their periodicity is interrupted, wherein either the azimuth angle is varied in the case of parallel lines or the periodicity changes in the case of wavy lines or the parallelism of linear or wavy strip conductors in the network is interrupted, with the result that when superimposed, the networks display no moiré

effect;

the conductive areas being spaced apart from each other by the transparent electrically insulation layer.

2. Touch sensor according to claim 1, wherein a protective layer is in a bend area comprising the fold line.

3. Touch sensor according to claim 1, wherein the third area is transparent.

4. Touch sensor according to claim 1 wherein the third area is non-transparent.

5. Touch sensor according to claim 1 wherein electrically conductive layers, the conductive areas, the strip conductors, the connection tracks for connecting the strip conductors, and/or connections on the plastic film are formed from the same conductive material.

6. Touch sensor according to claim 1 wherein at least the third area has an additional reinforcement and/or protective layer between the first and second transparent areas.

7. Touch sensor according to claim 1 wherein the third area has a gap through which the fold line is shortened.

8. Touch sensor according to claim 1 wherein the plastic film is a transparent or partially transparent plastic film and consists of any one of polyethylene terephthalate or polyethylene or polypropylene or polyvinyl chloride or polystyrene or polyester or polycarbonate or PMMA or polyamide or polyimide.

9. Touch sensor according to claim 1 wherein the plastic film comprises a paper or card layer at least in areas, or consists of paper or card.

10. Touch sensor according to claim 1 wherein the plastic film is formed by a multi-layered hybrid material which comprises plastic layers and layers of fibrous material.

11. Touch sensor according to claim 1 wherein the plastic film has at least one fourth area which adjoins the first and/or second transparent area and wherein, after the adhesion of the first and second areas, the fourth area projects beyond an edge thereof.