IP Verse

In-Cell Touch Panel

Patent No. US11126025 (titled "In-Cell Touch Panel") was filed by Paneltouch Technologies Llc on Feb 7, 2020.

What is this patent about?

’025 is related to the field of in-cell touch panels integrated within liquid crystal display (LCD) devices. These panels aim to provide both display and touch-sensing capabilities within a single device layer, offering a more compact and potentially cost-effective solution compared to traditional out-cell touch panels that are attached to the display surface. The background involves capacitive touch sensing, where changes in capacitance are detected to determine touch locations.

The underlying idea behind ’025 is to mitigate image quality degradation in in-cell touch panels caused by the interaction between common electrodes (used for both display and touch) and gate lines or data lines. The key inventive insight is to segment the common electrodes and then use bridge lines to maintain electrical connectivity between the segments, while also introducing dummy lines to create a uniform electrical environment.

The claims of ’025 focus on two primary configurations. One set of claims covers an in-cell touch panel where each common electrode is divided into segments by gate lines, and these segments are connected by bridge lines. Another set of claims covers an in-cell touch panel where common electrodes are separated by data lines, and a dummy touch line is placed in this separation area. Both configurations aim to improve image quality by reducing electrical interference.

In practice, the segmented common electrode design addresses the issue of capacitive coupling between the common electrodes and the gate lines, which can lead to image distortion. By dividing the common electrode and connecting the segments with bridge lines, the capacitive load is distributed more evenly. The dummy touch line, positioned between common electrodes, shields the liquid crystals from electromagnetic fields emanating from the data lines, preventing unwanted rotation and display artifacts.

The differentiation from prior approaches lies in the specific implementation of the bridge lines and dummy touch lines. While prior art may have explored in-cell touch sensing, ’025 provides a practical solution to the image quality problems arising from the close proximity of touch-sensing electrodes and display driving lines. The use of bridge lines in a separate layer from the common electrode, and the strategic placement of dummy touch lines, are key to achieving a uniform and high-quality display.

How does this patent fit in bigger picture?

Technical landscape at the time

In the late 2010s when ’025 was filed, in-cell touch technology was becoming more prevalent in display devices, at a time when touch sensing was typically implemented using capacitive methods. Systems commonly relied on patterned electrodes within the display stack to detect touch events, and hardware or software constraints made it non-trivial to minimize the impact of these touch-sensing electrodes on image quality.

Novelty and Inventive Step

The examiner approved the application because the prior art did not render obvious the specific arrangement of touch lines connected to common electrodes, along with a bridge line laterally connecting segment electrodes across division areas on the gate line. Also, the prior art did not render obvious the inclusion of a dummy touch line in the separation area between common electrodes, where the common electrodes are arranged in a specific direction and separated by a data line.

Claims

This patent contains 18 claims, with independent claims numbered 1, 10, and 18. The independent claims are directed to an in-cell touch panel comprising transistors, pixel electrodes, common electrodes, gate lines, data lines, and touch lines. The dependent claims generally elaborate on specific features and configurations of the in-cell touch panel described in the independent claims.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)Support for SpecificationInterpretation
Common electrodes
(Claim 1, Claim 10, Claim 18)		“In an in-cell touch panel that is an in-cell type liquid crystal display device having a touch function, a plurality of common electrodes are arranged in a matrix to detect a touch position. That is, each of the plurality of common electrodes becomes a unit electrode for detecting the touch position. In this case, two common electrodes (touch electrodes) adjacent in the column direction are separated from each other with an area on a gate line as a separation area.”Electrodes arranged in two directions that face pixel electrodes and are provided separately from each other. They are used for both displaying images and sensing touch.
Division area
(Claim 1, Claim 10)		“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.”An area on the gate line that divides each common electrode into segment electrodes.
Dummy touch line
(Claim 10, Claim 18)		“The in-cell touch panel includes: transistors and pixel electrodes respectively provided in the pixels; common electrodes arranged in the first direction and the second direction, respectively facing one or more of the pixel electrodes and provided separately from each other; gate lines that extend along the first direction and supply gate signals to the transistors respectively; data lines that extend along the second direction and supply data signals to the transistors respectively; touch lines that extend along the second direction and are each connected to a corresponding one of the common electrodes; and 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.”A line that extends along the second direction, is formed in the same layer as the touch lines, and is not electrically connected to any of the common electrodes.
Segment electrodes
(Claim 1, Claim 10)		“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.”Electrodes that make up each common electrode, divided with a division area on the gate line.
Touch lines
(Claim 1, Claim 10, Claim 18)		“The in-cell touch panel includes: transistors and pixel electrodes respectively provided in the pixels; common electrodes arranged in the first direction and the second direction, respectively facing one or more of the pixel electrodes and provided separately from each other; gate lines that extend along the first direction and supply gate signals to the transistors respectively; data lines that extend along the second direction and supply data signals to the transistors respectively; and touch lines that extend along the second direction and are each connected to a corresponding one of the common electrodes.”Lines that extend along the second direction and are each connected to a corresponding one of the common electrodes.

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US11126025

PANELTOUCH TECHNOLOGIES LLC
Application Number
US16784806
Filing Date
Feb 7, 2020
Status
Granted
Expiry Date
Feb 7, 2040
External Links
Slate, USPTO, Google Patents