PTAB

IPR2013-00567

Wintek Corp v. TPK Touch Solutions Inc

Key Events

Petition

petition

Title: Conductor Pattern Structure of a Capacitive Touch Panel
Brief Description: The ’902 patent relates to a conductor pattern structure for a capacitive touch panel and its manufacturing method. The structure uses first-axis and second-axis conductor assemblies made of a transparent conductive film, with insulation layers selectively covering conduction lines to simplify the structure and reduce thickness.

Prior Art Relied Upon: Binstead (Patent 6,137,427).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Binstead discloses every element of the challenged claims for a capacitive touchpad. Binstead’s structure includes a first series and a second series of conductor elements formed on a dielectric film, corresponding to the claimed first-axis and second-axis conductor assemblies. Petitioner mapped Binstead's "wider width parts" of the conductor elements to the claimed "conductor cells" and the "narrower width parts" to the "conduction lines." Critically, Binstead teaches depositing insulating material over the narrower conduction lines at their intersections without covering the adjacent wider conductor cells. The second series of conductors extends over this insulation, directly corresponding to the claimed arrangement. For claims requiring transparency, Petitioner asserted Binstead explicitly teaches that when the touchpad is used as a touch screen in front of a display, the conductor elements should consist of a transparent conductive material like indium oxide.

Prior Art Relied Upon: Binstead (Patent 6,137,427) and Honeywell (Japanese Published Patent Application No. 61-84729).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner contended that while Binstead taught the core structure, it did not explicitly disclose that the insulation layer itself is made of a transparent material or that the transparent conductive material is specifically Indium Tin Oxide (ITO), as required by certain dependent claims. Petitioner argued that Honeywell remedies these aspects by disclosing a touch screen that uses transparent materials, including ITO, for both its conductor cells and insulation layers.
- Motivation to Combine: A POSITA would combine these references for predictable results. Since Binstead suggests using its touchpad in front of a display, there is a clear motivation to make all components transparent to enhance visibility and reduce optical distortion. Honeywell teaches the use of transparent insulation material for this exact purpose. Further, substituting the indium oxide of Binstead with the ITO taught by Honeywell was argued to be a predictable substitution of one well-known transparent conductive material for another to achieve the same function.
- Expectation of Success: A POSITA would have had a high expectation of success in making this combination, as it involved applying known transparent materials to a touch screen application for their conventional and intended purpose.

Prior Art Relied Upon: Lambert (Published UK Patent Application GB 2 168 816 A).
Core Argument for this Ground:
- Prior Art Mapping: As an alternative to Binstead, Petitioner argued that Lambert also anticipates the vast majority of the challenged claims. Lambert discloses a transparent touch-sensitive screen comprising a pattern of first conductive strips (X-axis) and second conductive strips (Y-axis) on a rigid glass plate. The non-intersection portions of these strips function as the claimed conductor cells, while the intersection portions function as conduction lines. Lambert further teaches depositing a matrix of insulating material dots over the intersection points of the first strips, with the second strips extending across the surface of these insulating dots. This arrangement directly maps to the claimed structure of the ’902 patent. Lambert explicitly states that the conductive strips are formed of optically transparent material, such as indium-tin compounds.
Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Binstead or Lambert with Bolender (Application # 2005/0030048), Miller (Patent 5,374,787), and Seguine (Application # 2007/0229469) to address specific limitations such as the simultaneous formation of conductors, alternative capacitance measurement techniques, and the use of hexagonal-shaped conductor cells.

Petitioner argued for a specific construction of the term "in a substantially equally-spaced manner" as it applies to the first-axis and second-axis conductor cells.
Proposed Construction: "the distances between the centers of adjacent conductor cells or between the edges of adjacent conductor cells are substantially equal."
Rationale: Petitioner asserted this construction was necessary because the claim language is ambiguous as to whether the spacing is measured from the center or the edge of the cells. The proposed construction, covering both possibilities, was argued to be the broadest reasonable interpretation in light of the patent’s specification, where the disclosed embodiments satisfy both conditions.

Petitioner requests institution of an inter partes review and cancellation of claims 1-68 of Patent 8,217,902 as unpatentable.