1. Field of the Invention
The disclosure generally relates to a touch apparatus, and more particularly to a touch apparatus with an electrode layer bonded with an optically-clear adhesive (OCA) layer.
2. Description of Related Art
Touch screen input/output devices adopting sensing and display technologies have been widely accepted, and continue to be employed in electronic devices such as portable or hand-held electronic devices.
A capacitor-based touch panel as commonly used harnesses a capacitive coupling effect to detect touch position. Specifically, the change in capacitance corresponding to a given touch position is detected when a finger touches a surface of the touch panel.
The electrode layer of a conventional touch panel is manufactured by first forming indium tin oxide (ITO) on a transparent substrate (e.g., glass), followed by complex processes such as exposure, development and etching to obtain patterned electrodes. As the thickness of the transparent substrate cannot be effectively reduced, an overall thickness of the touch panel thus cannot be reduced in an effective manner.
For the foregoing reasons, a need has thus arisen to propose a novel touch apparatus for substantially overcoming disadvantages of the conventional touch panel.
In view of the foregoing, it is an object of the embodiment of the present invention to provide a touch panel with an electrode layer bonded with an optically-clear adhesive (OCA) layer, thereby effectively reducing an overall thickness of the touch panel and simplifying associated processes.
According to one embodiment, a touch apparatus includes at least one optically-clear adhesive (OCA) layer, a first electrode layer, and a second electrode layer. The second electrode layer is bonded with one of the at least one OCA layer, the OCA layer bonded with the second electrode layer acting as a substrate and an adhesive.
Referring more particularly to the drawings,
Poly styrene (PS), Polymethyl methacrylate (PMMA) or Cyclic olefin copolymer (COC).
A first electrode layer 12, such as a transmit electrode (commonly called Tx electrode), is formed on a top surface of the transparent substrate 11 using a conventional technique and is then patterned using a conventional technique. In the embodiment, the first electrode layer 12 may be made of transparent conductive material such as, but not necessarily, indium tin oxide (ITO), indium zinc oxide (IZO), Al-doped ZnO (AZO) or antimony tin oxide (ATO).
An optically-clear adhesive (OCA) layer 13 is formed above the first electrode layer 12. Then, a second electrode layer 14, such as a receive electrode (commonly called Rx electrode), is bonded with a top surface of the OCA layer 13. In the embodiment, the OCA layer 13 and the second electrode layer 14 compose a transparent conductive transfer film (TCTF), which may be directly bonded with the first electrode layer 12. The OCA layer 13 of the embodiment has a thickness greater than 50 micrometers. The second electrode layer 14 may comprise non-transparent conductive material such as metal nanowires (e.g., silver nanowires or copper nanowires) or metal nanonets (e.g., silver nanonets or copper nanonets). The metal nanowires or nanonets have diameters on the order of nanometers (i.e., a few nanometers to hundreds of nanometers), and may be fixed via a plastic material (e.g., resin). Due to their fineness the metal nanowires/nanonets are unobservable to human eyes, and the second electrode layer 14 made of the metal nanowires/nanonets thus has high light-transmittance. The second electrode layer 14 may further include a photosensitive material, through which electrodes with a required pattern may be directly formed via an exposure development process without using photoresist.
According to one aspect of the embodiment, the OCA layer 13 acts as a substrate (or a spacer) for the second electrode layer 14 to replace a conventional transparent substrate (e.g., glass or PET) and an adhesive. In other words, the OCA layer 13 of the embodiment exhibits at least functions of a substrate and an adhesive. Accordingly, compared with the architecture of a conventional touch panel, the touch apparatus 100 of the embodiment may be substantially reduced in overall thickness to facilitate thinning of the touch apparatus 100.
Above the second electrode layer 14 is an adhesive layer 15 that is bonded between the second electrode layer 14 and a cover layer 16. The adhesive layer 15 may comprise (solid) optically-clear adhesive (OCA) or (liquid) optically-clear resin (OCR). The cover layer 16 may be a two-dimensional cover layer with a planar surface, or a three-dimensional cover layer with a curved surface. The cover layer 16 may comprise flexible or rigid insulating material with high light-transmittance such as, but not necessarily, glass, Polycarbonate (PC), Polyethylene terephthalate (PET), Polymethyl methacrylate (PMMA) or Cyclic olefin copolymer (COC).
The touch apparatus 100 of
According to one aspect of the embodiment, in addition to the (second) OCA layer 13 acting as a substrate for the second electrode layer 14 to replace the conventional transparent substrate and the adhesive, the embodiment further utilizes the first OCA layer 21 acting as a substrate for the first electrode layer 22 to replace the conventional transparent substrate (e.g., the transparent substrate 11 in
On a bottom surface of the first OCA layer 21 of the embodiment may be included a release layer 23. When the release layer 23 is peeled off, the touch apparatus 200 may be bonded with another device, such as a liquid crystal module (LCM) 201, to result in a touch screen as illustrated in
On a bottom surface of the first OCA layer 21 of the embodiment may be included a release layer 23. When the release layer 23 is peeled off, the touch apparatus 300 may be bonded with another device, such as a liquid crystal module (LCM) 201, thereby to result in a touch screen as illustrated in
Although specific embodiments have been illustrated and described, it will be appreciated by those skilled in the art that various modifications may be made without departing from the scope of the present invention, which is intended to be limited solely by the appended claims.
Number | Date | Country | Kind |
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102142997 | Nov 2013 | TW | national |