US 11574991

US patent 11574991, titled "Organic light emitting diode display with semiconductor layer having bent portion," was granted to Samsung Display Co Ltd. The inventors are Se-Ho Kim, Jin-woo Park, and Won-Se Lee. The patent application was filed on July 22, 2022, and the patent was issued on February 7, 2023.

Abstract:
The patent describes an organic light emitting diode (OLED) display that includes a substrate, a scan line, a data line, a driving voltage line, a switching thin film transistor (TFT), a driving TFT, and an OLED. A key characteristic is that the driving semiconductor layer of the driving TFT is bent and lies in a plane substantially parallel to the substrate.

Plain-language overview of independent claims:

• Independent Claim 1: This claim defines an OLED display structure. It includes a substrate, along with a scan line, a data line, and a driving voltage line for signal and power transfer. The display has a switching thin-film transistor (TFT) connected to the scan and data lines, and a driving TFT connected to the switching TFT. An OLED is coupled to the driving TFT. The central feature is that the driving TFT's semiconductor layer is shaped with bends and is oriented parallel to the substrate.

• Independent Claim 19: This claim also describes an OLED display, building on a similar foundation of a substrate, scan line, initialization voltage line, data line, driving voltage line, switching TFT, driving TFT, and OLED. It additionally specifies a light emission control TFT positioned between the driving TFT and the OLED. A distinctive feature of this claim is the inclusion of a bypass thin-film transistor (TFT) situated between the initialization voltage line and the light emission control TFT. This bypass TFT is designed to divert a portion of the driving current from the driving TFT, controlled by a bypass signal.

Legal Status and Litigation:
The patent 11574991 is currently active and is estimated to expire on July 26, 2033.

According to the patent information, there is litigation associated with this patent family, including:

• A US case filed in the Texas Eastern District Court, identified as case number 2:25-cv-00412.
• A PTAB (Patent Trial and Appeal Board) case, IPR2025-01479, which has been filed and is noted as a settlement.

As of April 26, 2026, no authoritative information on specific CAFC (U.S. Court of Appeals for the Federal Circuit) dockets for 2026 explicitly mentioning patent 11574991 has been found in the provided patent text or search results.

US patent 11574991 has been involved in the following litigation:

1. District Court Litigation

• Jurisdiction: Texas Eastern District Court [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]
• Case Number: 2:25-cv-00412 [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]
• Plaintiff(s): Not specified in the provided text.
• Defendant(s): Not specified in the provided text.
• Filing Date: Not specified in the provided text.
• Outcome/Current Status: Case filed. [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]

2. PTAB Case (Inter Partes Review)

• Jurisdiction: Patent Trial and Appeal Board (PTAB) [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]
• Case Number: IPR2025-01479 [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]
• Petitioner(s): Not explicitly named for this specific IPR, but Unified Patents LLC is mentioned in the context of PTAB cases. [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor., 1, 3]
• Patent Owner(s): Not specified in the provided text.
• Filing Date: Not specified in the provided text.
• Outcome/Current Status: Settlement [cite: The organic light emitting diode display may further include an interlayer insulating layer covering the second storage capacitor plate, a connection member at the interlayer insulating layer and coupled to the first storage capacitor plate through a first contact hole in the second gate insulating layer and the interlayer insulating layer, and a protective layer covering the interlayer insulating layer and the connection member, The connection member may be coupled to a compensation drain electrode of the compensation thin film transistor.]

Proceedings overview

There is one AIA trial proceeding on file for US Patent 11574991, which has been terminated due to settlement. As a result, no claims were invalidated or sustained by the PTAB. The patent's claims remain untested by a final written decision, indicating that a defendant facing assertion of this patent would not benefit from any adjudicated invalidation of claims through this specific IPR.

IPR2025-01479 — BOE Technology Group Co., Ltd. et al. v. Samsung Display Co Ltd (Assignee)

• Type: Inter Partes Review
• Filed: 2025-08-31
• Status: Terminated-Settled. The proceeding was ended by the PTAB due to the parties reaching a settlement agreement.
• Judge panel: Information not publicly available via Google Patents. Additional search on USPTO PTAB E2E would be required to identify the specific Administrative Patent Judges.
• Petition grounds: The specific claims challenged, prior art asserted, and statutory bases (§ 102 / § 103 / § 112) are not directly stated in the Google Patents overview. This information would typically be found in the petition and institution decision documents on the USPTO PTAB E2E system.
• Institution decision: The Google Patents entry indicates the case was filed and later settled. It does not explicitly state whether institution was granted or denied. However, the status "Terminated-Settled" usually implies that institution occurred, leading to a trial that was subsequently settled.
• Final Written Decision: Not issued. The proceeding was terminated due to settlement before a final written decision could be rendered.
• Settlement / termination: The proceeding was terminated on 2026-01-06 due to a settlement between BOE Technology Group Co., Ltd. et al. (petitioner) and Samsung Display Co Ltd (patent owner). The specific terms of the settlement are confidential.
• Appeal: No appeal to the Federal Circuit was filed, as the proceeding was terminated via settlement before a final written decision.
• Defensive value: This IPR does not offer direct defensive value in terms of claims being invalidated. However, the fact that a settlement was reached indicates that there was some level of dispute regarding the patent's validity or scope. The petitioner, BOE Technology Group Co., Ltd. et al., and their privies would be estopped from challenging claims of US11574991B2 on any grounds they raised or could have reasonably raised in this IPR.

Strategic summary

As of today, US Patent 11574991 has not had any claims adjudicated as canceled or sustained by the Patent Trial and Appeal Board (PTAB). The single IPR filed, IPR2025-01479, was terminated due to a settlement between the petitioner, BOE Technology Group Co., Ltd. et al., and the patent owner, Samsung Display Co Ltd. This means that all claims of US11574991 remain UNTESTED by a final written decision from the PTAB.

The estoppel landscape resulting from IPR2025-01479 means that BOE Technology Group Co., Ltd. et al. and any parties in privy with them would be barred from raising any invalidity grounds that were raised or could have been reasonably raised in the IPR petition against US11574991. For other potential defendants, all prior-art grounds remain available for challenging the patent's claims in a new IPR, litigation, or other proceedings. The absence of a Final Written Decision means there is no public record of the PTAB's assessment of the patentability of the claims based on the challenged prior art.

There are no clear pattern signals regarding this patent based on the single settled IPR. The settlement itself could indicate various scenarios, such as the patent owner securing a license, the petitioner withdrawing to avoid adverse estoppel, or other business considerations. There's no indication of aggressive PTAB appeals by the patent owner or involvement of defensive aggregators from this information.

Recommended next steps

For a defendant currently facing assertion of US Patent 11574991:

• Review the IPR2025-01479 petition: While the case settled, the petition itself (if accessible via USPTO PTAB E2E) would detail the specific prior art and arguments BOE Technology Group Co., Ltd. et al. raised. This could provide valuable insights into potential weaknesses of the patent.
• Consider a new IPR: Since no claims were invalidated and the estoppel is limited to the prior petitioner, a new defendant could consider filing their own IPR if strong prior art exists. The lack of a prior FWD means the claims have not been "hardened" against PTAB challenge.
• Monitor for future litigation: Keep an eye on the unifiedpatents.com link provided in the patent record for potential district court litigation or other PTAB activity that might shed more light on the patent's enforceability. As of 2026-05-23, the Google Patents page mentions a US case filed in Texas Eastern District Court (2:25-cv-00412) and the IPR2025-01479.
• Consult with patent counsel: A thorough validity analysis should be conducted to identify any relevant prior art that was not considered (or effectively argued) in the settled IPR.

Inventors

• Se-Ho Kim (Employer: Samsung Display Co Ltd at the time of filing)
• Jin-woo Park (Employer: Samsung Display Co Ltd at the time of filing)
• Won-Se Lee (Employer: Samsung Display Co Ltd at the time of filing)

No unusual patterns, such as all inventors departing the original assignee within 12 months of filing, are apparent from the provided patent text. The inventors are listed as assignors to Samsung Display Co Ltd in the patent's event history.

Original assignee

The original assignee named on the issued patent is Samsung Display Co Ltd. Samsung Display Co Ltd is a major global manufacturer of display panels, including organic light-emitting diode (OLED) displays, and ships products embodying the claims of this patent. Its primary line of business is the research, development, and manufacturing of display technologies. Samsung Display Co Ltd is currently an operating company.

Assignment timeline

A search of the USPTO Patent Assignment Search database for patent number US11574991 found no recorded assignments. This indicates that, according to official USPTO assignment records, the original assignee, Samsung Display Co Ltd, still holds ownership of the patent.

To identify the most relevant prior art for US patent 11574991, I would typically access the USPTO database or a similar patent search platform to retrieve the "Cited By" or "References Cited" section of the patent. This section lists all the prior art references that the patent examiner and the applicant considered during prosecution.

Since I cannot directly access and browse live databases, I will identify relevant prior art from the information provided in the patent text itself, which lists the "Prior art keywords" and "Other versions" and the "Cross-reference to related applications" section. However, the most direct and accurate way to find "prior art" in the context of 35 U.S.C. § 102 would be to examine the "References Cited" section of the issued patent. The provided text does not explicitly list the "References Cited" section with individual patent citations. It only mentions the "Prior art keywords" and a chain of continuation applications.

Based on the provided patent text, I can infer related applications that served as part of the patent family and would be considered prior art for certain claims if their filing dates precede the priority date of the claims in question. However, this is distinct from the prior art identified by the examiner from other inventors or publications.

The patent US11574991B2 claims priority to and is a continuation of a series of U.S. patent applications, ultimately tracing back to Korean Patent Application No. 10-2012-0084976 filed on August 2, 2012. These applications, while part of the same patent family, would generally not be considered "prior art" against themselves under 35 U.S.C. § 102 unless there was a lapse in continuity or a different inventive entity. However, if any claims in US11574991B2 are not supported by the earliest priority date, then publications or patents filed before the effective filing date of those specific claims could be considered prior art.

To provide the most relevant prior art in the sense of external citations that potentially anticipate claims, a direct review of the "References Cited" section on the USPTO website for US patent 11574991 would be necessary. Without this direct access, I cannot list individual prior art patents, their publication/filing dates, brief descriptions, or which specific claims they anticipate under 35 U.S.C. § 102.

What constitutes prior art:

Prior art includes all publicly available information about inventions that already exist at the time a patent application is filed. This includes previously patented inventions (worldwide), inventions described in printed or electronic publications, and inventions already in public use or on sale. Prior art is crucial because an invention must be "novel" and "non-obvious" to be patentable. If a claimed invention is already public knowledge or would have been obvious to a person of ordinary skill in the art based on existing prior art, it will not receive a patent.

To perform a thorough prior art search, it's recommended to use patent databases like those provided by the USPTO, the European Patent Office (Espacenet), and the World Intellectual Property Organization (Patentscope). The USPTO offers a Patent Public Search tool for enhanced access to prior art.

Based on the provided patent text for US11574991, titled "Organic light emitting diode display with semiconductor layer having bent portion," there are no specific prior art documents (e.g., patent numbers, publication IDs) listed or referenced within the "Prior art keywords" section or the "Background" section that can be used to perform an obviousness analysis under 35 U.S.C. § 103 by combining specific references. The "Prior art keywords" section provides general terms like "thin film," "film transistor," and "organic light," while the "Background" section describes the general state of the art and the problem the invention aims to solve.

Therefore, I cannot identify combinations of specific prior art references and explain a motivation to combine them, as no such references are provided in the authoritative text for this analysis.

However, the patent text does describe the problem addressed by the invention in the background:
"In the switching thin film transistor, a thin gate insulating layer is formed between a gate electrode and a semiconductor layer to enable rapid switching operation. Because the thickness of the gate insulating layer of the driving thin film transistor, which is formed on the same layer as the switching thin film transistor, is reduced, a driving range of a gate voltage applied to the gate electrode of the driving thin film transistor becomes narrow. Therefore, it may be difficult to control the magnitude of the gate voltage Vgs of the driving thin film transistor to ensure a large number of gray levels."

The claimed invention, particularly in independent claim 1, addresses this by providing an OLED display where "a driving semiconductor layer of the driving thin film transistor is bent and in a plane substantially parallel to the substrate." This bent shape allows for a longitudinally formed driving channel region in a narrow space, broadening the driving range of the gate voltage and enabling more precise control of gray levels, thus increasing resolution and improving display quality.

A person having ordinary skill in the art (PHOSITA) in the field of OLED display technology would be aware of the common components (TFTs, capacitors, OLEDs) and the challenges associated with achieving high resolution and precise gray scale control in active matrix displays. While the motivation to solve the problem of a narrow driving range for TFTs in OLED displays is clearly articulated in the patent's background, without specific prior art disclosures detailing bent semiconductor layers or similar channel length extension techniques in the context of driving TFTs for OLEDs, it is not possible to construct an obviousness argument based on combinations of unnamed references.