Obviousness

Obviousness Analysis under 35 U.S.C. § 103

This analysis will consider the obviousness of US patent 8319512 under 35 U.S.C. § 103, identifying combinations of prior art references that would render the claims obvious and explaining the motivation for such combinations by a person having ordinary skill in the art (PHOSITA). A PHOSITA in this field would likely have knowledge in flexible circuit design, integrated circuit testing, and electro-optical device manufacturing.

General Considerations for Obviousness

For a claim to be obvious, there must be a reason for a PHOSITA to combine existing prior art elements in the way claimed, with a reasonable expectation of success. The prior art need not explicitly suggest the combination, but a motivation to combine may be found in the nature of the problem to be solved, the common knowledge in the art, or other extrinsic evidence. Drawings in prior art can anticipate or make claims obvious if they clearly show the claimed structure and how elements are put together.

The patent US8319512 itself refers to JP-A-2005-43418 as related art, acknowledging that an integrated circuit may be formed on a flexible substrate to drive a liquid crystal panel, and that inspecting this integrated circuit by monitoring signals is known. The problem identified in US8319512 is that if an inspection terminal is on the liquid crystal panel, it increases the number of terminals and complicates the device, and cannot monitor internal IC signals.

Analysis of Independent Claims

Claim 1: Flexible substrate with inspection electrode and on/off switching

Claim 1 describes a flexible substrate with a substrate body, lines, connection terminals, an integrated circuit (IC) connected to at least one line, an inspection electrode on the substrate body electrically connected to the IC and capable of outputting a processed signal, and a switching section that turns the inspection electrode's operation on/off.

Combination of Prior Art: JP-A-2005-43418 in view of US5483173A and general knowledge of IC testing.

1. JP-A-2005-43418 (admitted prior art): This reference explicitly teaches forming an integrated circuit on a flexible substrate to drive a liquid crystal panel and inspecting the IC by monitoring processed signals. This establishes the core concept of a flexible substrate with an integrated circuit and the need for signal monitoring. Although not detailed in the provided text, as admitted prior art, a PHOSITA would be aware of its contents regarding flexible substrates and ICs for electro-optical devices.
2. US5483173A (Pellegrini): This patent discloses a "current measuring structure for testing integrated circuits." While the full details of Pellegrini are not provided, the title suggests a means for directly measuring signals within an IC for testing purposes. A PHOSITA would understand that integrated circuits require testing and that test structures are commonly integrated into or around ICs.
3. Motivation to Combine: The problem US8319512 aims to solve is the complication and limitation of monitoring internal IC signals when inspection terminals are on the liquid crystal panel. A PHOSITA, aware of flexible substrates with integrated circuits (JP-A-2005-43418) and existing IC testing structures (US5483173A), would be motivated to integrate the current measuring/inspection functionality directly onto the flexible substrate to address these known limitations. This would reduce external connections and allow for monitoring signals that are not otherwise output from the flexible substrate. The addition of a "switching section" to turn the inspection electrode on/off would be an obvious design choice for managing power consumption or controlling when testing occurs, as switching circuits are fundamental to electronic design. For example, signal monitoring circuits are known to include switching units. This is a common practice in integrated circuit test equipment to control the testing process and manage resources.

Therefore, a PHOSITA would find it obvious to integrate an inspection electrode (as suggested by Pellegrini's current measuring structure) onto the flexible substrate of JP-A-2005-43418 to output processed signals from the integrated circuit, and to further include a switching section to control its operation (on/off) for efficient testing and power management.

Claim 8: Flexible substrate with inspection electrode and signal type switching

Claim 8 is similar to Claim 1 but specifies a "switching section that switches the types of signals that are to be output from the inspection electrode."

Combination of Prior Art: JP-A-2005-43418 in view of US5483173A and JPH07146339A (Integrated circuit emulation test equipment) or general knowledge of multiplexing/signal selection.

1. JP-A-2005-43418 and US5483173A: As discussed for Claim 1, these references establish the flexible substrate with an IC and the concept of an inspection electrode.
2. JPH07146339A (Integrated circuit emulation test equipment): While the full content of this reference is not available, the title "Integrated circuit emulation test equipment" strongly suggests systems for testing ICs. Testing complex ICs often involves monitoring various internal signals. Modern automated test equipment (ATE) for ICs is highly sophisticated and can test complex circuits, including systems-on-chip with many pins and high clock rates, implying the ability to select and monitor different signals.
3. Motivation to Combine: Given the need to monitor different signals within an IC for comprehensive testing (as implied by the existence of IC test equipment like JPH07146339A), a PHOSITA would be motivated to incorporate a switching mechanism to select among different signals to be output by the inspection electrode. This is a common and logical design choice in diagnostic or test circuits (e.g., multiplexers) to allow a single output path (the inspection electrode) to provide access to multiple internal points of interest, especially when space is limited on a flexible substrate. The patent itself notes that a switching section capable of switching signal types allows many signals to be inspected even with a single inspection electrode, efficiently using space. This demonstrates a clear motivation rooted in efficient design and comprehensive testing. The signal selector 252 in US8319512, described as an example of a switching section, explicitly selects one signal from a plurality of signals.

Therefore, a PHOSITA, recognizing the need for versatile IC testing on flexible substrates, would find it obvious to combine the flexible substrate with an inspection electrode (from JP-A-2005-43418 and US5483173A) with a signal switching mechanism (as would be known in the art, potentially exemplified by more detailed disclosures in JPH07146339A or general knowledge of IC test equipment design) to allow selection of different signals for output via the inspection electrode.

Claim 9: Flexible substrate with inspection electrode between wirings and signal type switching

Claim 9 specifies a flexible substrate with wirings, connection terminals, an inspection electrode electrically connected to an IC and capable of outputting a processed signal, a switching section that switches the types of signals, and critically, that "the inspection electrode being disposed between one of the plurality of wirings and another one of the plurality of wirings."

Combination of Prior Art: JP-A-2005-43418 in view of US5483173A, JPH07146339A (or general knowledge of signal selection), and principles of flexible circuit layout.

1. JP-A-2005-43418, US5483173A, and JPH07146339A: These references establish the flexible substrate, IC, inspection electrode, and signal type switching, as discussed for Claim 8.
2. Principles of flexible circuit layout: Flexible substrates are known for their ability to include many lines in a small space, facilitating miniaturization. Efficient routing of traces (wirings) and placement of components are fundamental aspects of flexible printed circuit board (FPCB) design. When designing FPCBs, placing components and test points in available spaces between existing wirings is a common and often necessary practice to optimize space and minimize the overall footprint of the flexible substrate. For example, research discusses the impact of manufacturing processes on the reliability of flexible printed circuits, indicating a mature understanding of their layout and design.
3. Motivation to Combine: A PHOSITA, faced with the space constraints inherent in flexible substrates and the desire to efficiently integrate an inspection electrode (with signal switching capability), would be motivated to place the inspection electrode in an available space, such as "between one of the plurality of wirings and another one of the plurality of wirings." This placement is a logical and common design choice for space optimization on a compact circuit board, especially a flexible one where maximizing the utility of available surface area is crucial. The patent itself highlights that the flexible substrate is capable of including many lines in a small space and that the configuration is effective when a layout of lines or pitch of connection terminals is restricted to reduce the size of the flexible substrate. This underscores the known advantages of compact design in this field.

Therefore, a PHOSITA would find it obvious to combine the elements of Claim 8 with the common design practice of placing an inspection electrode in an interstitial space between existing wirings on a flexible substrate to achieve a compact and efficient layout, driven by the known advantages of flexible substrates in space utilization.

Claim 10: Flexible substrate with inspection electrode between wirings (without explicit switching)

Claim 10 is similar to Claim 9 but does not explicitly include a switching section for the types of signals. It focuses on the flexible substrate having wirings, connection terminals, an inspection electrode electrically connected to an IC and capable of outputting a processed signal, and "the inspection electrode being disposed between one of the plurality of wirings and another one of the plurality of wirings."

Combination of Prior Art: JP-A-2005-43418 in view of US5483173A and principles of flexible circuit layout.

1. JP-A-2005-43418 and US5483173A: These references establish the flexible substrate, IC, and the concept of an inspection electrode for monitoring processed signals, as discussed for Claim 1.
2. Principles of flexible circuit layout: As explained for Claim 9, placing components like inspection electrodes in interstitial spaces between wirings is a common and practical design approach for flexible substrates to optimize space.
3. Motivation to Combine: A PHOSITA would be motivated to combine the flexible substrate with an integrated circuit and an inspection electrode (as taught by JP-A-2005-43418 and US5483173A) with the space-saving placement of the inspection electrode between wirings. This is driven by the continuous industry pressure for miniaturization and efficient use of board space, particularly in flexible electronics. Even without explicit signal-type switching, having a fixed inspection point for a particular signal in a compact location would be a desirable and obvious design choice for initial debugging, quality control, or monitoring of critical internal signals. The problem addressed by US8319512 is precisely the complication of increased terminals and inability to monitor internal signals. Placing an inspection electrode directly on the flexible substrate in a compact manner solves this.

Therefore, a PHOSITA would find it obvious to integrate an inspection electrode onto the flexible substrate containing an IC, capable of outputting a processed signal, and to strategically place this inspection electrode between existing wirings to achieve a compact design. This combination would be driven by the inherent advantages of flexible substrates in minimizing device size and the known need for IC inspection.