Obviousness

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

To establish obviousness under 35 U.S.C. § 103, it must be shown that the claimed invention as a whole would have been obvious to a person having ordinary skill in the art (POSA) at the time of the invention. This requires identifying: 1) the scope and content of the prior art, 2) the differences between the prior art and the claims at issue, 3) the level of ordinary skill in the pertinent art, and 4) any secondary considerations of non-obviousness.

For US Patent 11126025, the independent claims (Claim 1) describe an in-cell touch panel with specific features related to common electrode segmentation, touch line connections, and the arrangement of these elements relative to gate and data lines. The second object of the invention also introduces the concept of a "dummy touch line" to prevent image quality degradation.

Prior Art References

The patent itself identifies International Publication No. 2017/213173 as relevant prior art. Additional relevant prior art can be found through Google Patent searches.

• International Publication No. 2017/213173: Discloses an in-cell type liquid crystal display device with a touch function, including gate lines, data lines, pixel electrodes, common electrodes (counter electrodes), and signal lines connected to the common electrodes as touch lines. It describes supplying a touch drive signal to the counter electrode and receiving a touch detection signal via the signal line to sense touch. The patent further clarifies that in this prior art, two common electrodes adjacent in the column direction are separated with an area on a gate line as a separation area.
• US9170692B2 (Kim et al.): Titled "Capacitive in-cell touch screen, driving method for the same, and display apparatus," this patent describes a self-capacitance touch screen with common electrode lines electrically connected to common electrodes, arranged in the gap between adjacent columns of pixel units where no touch driving signal line is set. The common electrodes are separated generally along the gap between adjacent pixel units.
• "In-Cell Projected Capacitive Touch Panel Technology" (Sugita et al.): This 2013 paper discusses in-cell touch panel technology, specifically mentioning that the common ITO (Indium Tin Oxide) can be divided into segments for use as touch panel electrodes. It also highlights the importance of designing low-load electrodes and efficiently synchronizing display drive and touch panel drive to avoid crosstalk.
• "In-cell Capacitive Touch Panel Design" (Seo et al.): This research proposes an active self-capacitive sensing method and a readout circuit to sense variations in self-capacitance in in-cell touch panels, aiming to reduce the number of sensing lines. It mentions capacitances between various layers, including between the common electrode and data line (CCD) and between the common electrode and gate line (CCG). It also discusses improving the signal-to-noise ratio by compensating for stray capacitance.
• "The Effects of Electromagnetic Interference on Capacitive Touch Screens" (Chinacts): This article discusses how EMI affects capacitive touchscreens by inducing extraneous voltages, altering capacitance, and leading to false touches or distorted inputs. It also explains that EMI can distort the electric field used by the touch screen to detect touches, causing erroneous signals. Mitigation strategies include shielding, grounding, and filtering.

Level of Ordinary Skill in the Art

A person having ordinary skill in the art (POSA) in the field of in-cell touch panel technology at the time of the invention (around February 2019, the priority date of US11126025) would possess a bachelor's degree in electrical engineering, materials science, or a related field, along with several years of experience in display and/or touch panel design and manufacturing. Such a person would be familiar with different touch sensing methods (self-capacitive and mutual-capacitive), various in-cell display architectures, and common issues related to image quality degradation due to electrical interference.

Obviousness Combinations and Rationale

Combination 1: International Publication No. 2017/213173 + Sugita et al. (2013) + general knowledge of reducing coupling capacitance

Claim 1 Analysis:
Claim 1 describes:

• An in-cell touch panel with an image display area of pixels arranged in first (row) and second (column) directions.
• Transistors and pixel electrodes in the pixels.
• Common electrodes arranged in the first and second directions, facing pixel electrodes and provided separately.
• Gate lines extending along the first direction, supplying gate signals.
• Data lines extending along the second direction, supplying data signals.
• Touch lines extending along the second direction, each connected to a corresponding common electrode.
• Each common electrode having segment electrodes divided with an area on the gate line as a division area, and each segment electrode connected by at least one touch line.

International Publication No. 2017/213173 discloses an in-cell touch panel with gate lines, data lines, pixel electrodes, common electrodes (counter electrodes), and touch lines connected to the common electrodes. The common electrodes are separated from each other with an area on a gate line as a separation area. This reference therefore provides the fundamental in-cell touch panel structure and the concept of common electrodes separated by gate lines.

The limitation that "each common electrode has segment electrodes divided with an area on the gate line as a division area, and each segment electrode included in one of the plurality of common electrodes is connected by at least one of the touch lines" would be obvious when considering the teachings of Sugita et al. (2013) and the known problem of common distortion. Sugita et al. explicitly states that the common ITO can be divided into segments for use as touch panel electrodes. The problem addressed by US11126025 is the degradation of image quality due to common distortion caused by coupling capacitance (Cgc) between the gate line and the common electrode, especially when common electrodes partially face gate lines.

A POSA would understand that dividing the common electrodes into segments at the gate line (as a "division area") and then connecting these segments with touch lines would be a logical step to address the issue of varying coupling capacitance along the common electrode. By segmenting the common electrode where it crosses a gate line, the direct overlap and thus the coupling capacitance between the gate line and a continuous common electrode can be managed or reduced. Electrically connecting these segments with touch lines ensures that the segmented common electrode still functions as a single unit for touch detection and for applying the common voltage (Vcom). The patent itself states that "each common electrode is divided in a plurality of segment electrodes 30a with the area on gate line 40 as a boundary" and "each of the plurality of segment electrodes 30a included in one common electrode 30 is electrically connected to each other by at least one touch line 60." This directly addresses the stated problem by creating discrete segments that avoid direct overlap with the gate line while maintaining electrical continuity.

Motivation to Combine:
The motivation to combine these references would stem from the desire to improve image quality in in-cell touch panels, particularly by mitigating the common distortion caused by coupling capacitance between gate lines and common electrodes. International Publication No. 2017/213173 provides the basic in-cell structure where common electrodes are separated by gate lines. Sugita et al. (2013) teaches the segmentation of common electrodes for touch functionality. A POSA, facing the problem of image degradation due to gate line-common electrode coupling, would naturally consider segmenting the common electrodes at the problematic areas (i.e., over the gate lines) to minimize this coupling, and then using existing touch lines (as described in International Publication No. 2017/213173) to connect these segments to maintain their functionality as a single touch unit. This modification would be a straightforward engineering solution to a known problem using existing techniques.

Combination 2: International Publication No. 2017/213173 + Seo et al. (2017) + Chinacts (2025)

Claim 1 (and implicitly Claim 2 related to dummy touch lines) Analysis:
The second object of US11126025 addresses the problem of display unevenness caused by an electromagnetic field from data lines affecting liquid crystal molecules in the vicinity of gaps between adjacent common electrodes. To solve this, the patent introduces a "dummy touch line that extends along the second direction, is formed in a same layer as the touch lines, and is not electrically connected to any of the common electrodes," and is "provided in the separation area" between two common electrodes adjacent in the first direction (rows) with an area on the data line as a separation area.

International Publication No. 2017/213173 describes an in-cell touch panel with gate lines, data lines, pixel electrodes, common electrodes, and touch lines. It establishes the context of an in-cell display with a touch function.

Seo et al. (2017) discusses various capacitances within an in-cell touch panel, including "a capacitance between common electrode and data line (CCD)." This highlights the awareness in the art of the electrical interaction between data lines and common electrodes.

Chinacts (2025) explicitly details how electromagnetic interference (EMI) affects capacitive touchscreens by inducing extraneous voltages, altering capacitance, and leading to false touches or distorted inputs. It also explains that EMI can distort the electric field used by the touch screen to detect touches, causing erroneous signals. Critically, it mentions mitigation strategies for EMI, including "shielding." Similarly, Riverdi (2023) mentions shielding as a strategy to reduce EMI in display technologies.

A POSA, faced with the problem of display unevenness caused by electromagnetic fields from data lines affecting liquid crystal molecules in the gaps between common electrodes, would be motivated to introduce a shielding element. The data lines are identified as the source of the electromagnetic field. The gaps between common electrodes are where the liquid crystal molecules are being unintentionally rotated. Given that touch lines are already present and are typically made of a conductive material like metal (copper in US11126025), and that the patent describes them as being in a "third wiring layer (CMT layer)" separate from the data lines and gate lines, a POSA would find it obvious to place an additional, non-connected conductive line (a "dummy touch line") in the same layer as the existing touch lines, within the separation area above the data line. This dummy line would act as an electromagnetic shield to mitigate the influence of the data line on the liquid crystal, similar to the shielding techniques described by Chinacts (2025) and Riverdi (2023). The fixed voltage applied to the dummy touch line (even if floating) would further enhance its shielding effect by providing a stable potential to block electromagnetic interference.

Motivation to Combine:
The motivation to combine these references is to improve image quality by preventing display unevenness caused by electromagnetic interference from data lines in in-cell touch panels. International Publication No. 2017/213173 provides the base in-cell display. Seo et al. (2017) makes it clear that the interaction between common electrodes and data lines is a recognized aspect of these systems. Chinacts (2025) teaches the detrimental effects of EMI on capacitive touchscreens and mentions shielding as a mitigation strategy. A POSA, observing display unevenness in the gaps between common electrodes over data lines, would readily apply the known principle of electromagnetic shielding by placing a conductive line (a dummy touch line) in that gap. Placing it in the same layer as the existing touch lines would be a practical and cost-effective manufacturing choice, as it leverages existing process steps and materials.

Conclusion on Obviousness

Based on the analysis, key features of US11126025, particularly the segmentation of common electrodes at gate lines and the use of dummy touch lines for shielding, appear to be obvious in light of the cited prior art and the problems they were designed to solve. The identified prior art references disclose the core components and functionalities of in-cell touch panels, the concept of segmenting electrodes, and the known issues of coupling capacitance and electromagnetic interference in such displays, along with common solutions like shielding. A person of ordinary skill in the art would have been motivated to combine these teachings to address the recognized problems of image quality degradation.