Obviousness

Analysis of Obviousness for U.S. Patent No. 11,251,394

An analysis of U.S. Patent No. 11,251,394 ("the '394 patent") in light of publicly available prior art indicates that its claims may be vulnerable to an obviousness challenge under 35 U.S.C. § 103. The core concept of the '394 patent, which involves integrating touch-sensitive electrodes within the encapsulation layers of an Organic Light Emitting Diode (OLED) display, appears to be a predictable combination of known elements in the art.

Key Claim of the '394 Patent:

The '394 patent claims an organic light emitting display that includes:

• Light-emitting elements on a substrate.
• An encapsulation unit on the light-emitting elements, comprising multiple inorganic layers and at least one organic layer between them.
• Touch sensing lines and touch driving lines that intersect, with at least one of the encapsulation layers acting as the dielectric insulator between them.

Prior Art Analysis and Obviousness Combinations:

A person of ordinary skill in the art of display technology at the time of the invention would have been familiar with both OLED display manufacturing and the integration of touch sensors into display panels. Several prior art references disclose the key elements of the '394 patent, and their combination would have been a logical and predictable step to achieve a thinner, more integrated touch-sensitive display.

Combination 1: US Patent Application Publication No. 2018/0088726 A1 (US '726) in view of Industry Knowledge of Thin-Film Encapsulation (TFE)

• US '726: This application explicitly discloses an organic light-emitting display panel with an encapsulation layer and touch electrodes located on that encapsulation layer. It further describes that the encapsulation layer can be a multi-layer structure. The '726 application, therefore, teaches the fundamental concept of placing touch sensor components directly onto the protective layers of an OLED display.

• Industry Knowledge of TFE: It is well-established in the art that Thin-Film Encapsulation (TFE) for OLEDs commonly consists of alternating inorganic and organic layers to provide a robust barrier against moisture and oxygen while maintaining flexibility. This multi-layer structure is designed to protect the sensitive organic materials in the OLED.

• Motivation to Combine: A person of ordinary skill in the art, seeking to implement the in-cell touch concept of US '726, would naturally look to the standard TFE structures used in the industry. The multi-layer TFE structure, with its inherent insulating layers (both organic and inorganic), provides a convenient and pre-existing platform to form the intersecting touch-sensitive lines. Using these existing layers as the dielectric for the touch sensor would eliminate the need for a separate, dedicated insulating layer, thereby simplifying the manufacturing process, reducing thickness, and lowering costs. This is a strong motivation for combining the teachings of US '726 with the known principles of TFE construction. The combination directly leads to the structure claimed in the '394 patent, where touch lines are separated by one or more of the encapsulation layers.

Combination 2: General Knowledge of On-Cell and In-Cell Touch Integration with Specific Encapsulation Structures

• General Knowledge of "On-Cell" and "In-Cell" Touch: The industry has long pursued the integration of touch sensors directly into display panels to create thinner and lighter devices. This has led to the development of "on-cell" approaches, where the touch sensor is formed on top of the display's encapsulation layer, and "in-cell" approaches, where the touch sensor components are integrated within the display's pixel stackup.

• Knowledge of TFE Structure and Materials: As established, the use of multi-layer inorganic and organic films for OLED encapsulation was common knowledge. These layers, such as silicon nitride (SiNx) and silicon oxide (SiOx) for the inorganic barriers and various polymers for the organic planarization layers, are known to have dielectric properties suitable for insulating conductive lines.

• Motivation to Combine: A person skilled in the art, tasked with designing a more integrated and cost-effective OLED display with touch functionality, would have recognized the potential of the existing TFE layers to serve a dual purpose. Instead of adding a separate touch panel on top of the completed display (a less integrated approach), it would have been an obvious design choice to pattern the touch electrodes directly onto one of the TFE's inorganic layers and then deposit the subsequent organic and inorganic layers over them. This would leverage the existing manufacturing steps and materials to create the necessary insulating separation between the driving and sensing lines of the touch sensor. The goal of achieving a thinner, more flexible, and less complex device would have provided the clear motivation to combine the known principles of on-cell/in-cell touch with the standard multi-layer TFE structure, resulting in the invention claimed in the '394 patent.

Conclusion:

Based on the foregoing analysis, the claims of US Patent 11,251,394 appear to be obvious over the combination of prior art references. The key inventive concept of utilizing the existing encapsulation layers of an OLED display as the dielectric for an integrated touch sensor represents a predictable and logical extension of known technologies in the fields of OLED manufacturing and touch sensor integration. The motivation to simplify the manufacturing process, reduce device thickness, and lower costs would have led a person of ordinary skill in the art to combine these known elements to arrive at the claimed invention.