Assignment history

Inventors

The named inventors for US Patent 8947962 are Ian Shaeffer and Kyung Suk Oh. At the time of the patent's underlying priority date (December 21, 2006) and the original application filing (June 18, 2009 for PCT/US2007/088245, from which this patent claims priority), they were employed by Rambus Inc. This is evidenced by the assignment of their interest to Rambus Inc. with an effective date of December 8, 2009. There is no indication that all inventors departed the original assignee within 12 months of filing.

Original assignee

The original assignee named on the issued patent is Rambus Inc. Rambus Inc. is primarily a semiconductor IP company that licenses its memory technologies (including high-speed interface technologies) to other manufacturers rather than directly shipping end-user products embodying the claims, such as complete memory modules. The company is currently operating.

Assignment timeline

• 2009-12-08 (executed) / recorded 2015-02-11 — Reel 034940/0418

  • Conveyance: ASSIGNMENT
  • Assignor: OH, KYUNG S. AND SHAEFFER, IAN P.
  • Assignee: RAMBUS INC.
  • Correspondent: RAMBUS INC.; ATTN: PATENT DOCKETING; 1050 ENTERPRISE WAY, SUITE 700; SUNNYVALE, CA 94089.
  • Context: Transfer of inventor's rights to the corporate employer (original assignee).

• 2025-09-29 (executed) / recorded 2025-10-15 — Reel 073085/0650

  • Conveyance: ASSIGNMENT
  • Assignor: RAMBUS INC.
  • Assignee: SIGNAL LLP
  • Correspondent: MICHAEL T. ANDERSON; LILLER & STRIBLING PLLC; 1401 MCKINNEY STREET, SUITE 1650; HOUSTON, TX 77010.
  • Context: Transfer of patent from original assignee (Rambus Inc.) to Signal LLP.

Timeline diagram

timeline
    title Ownership of US 8947962
    2009 : Inventors assign to Rambus
    2015 : Patent granted
    2025 : Assigned to Signal LLP
         : Litigation filed

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The transfer from Rambus Inc. (an operating company) to Signal LLP is a strong indicator. Signal LLP's name suffix "LLP" (Limited Liability Partnership) can be indicative of a non-operating entity, especially in the context of patent assertion. The litigation noted in the patent summary initiated in 2026, shortly after this assignment.
2. Known asserter in the chain — Unclear. Signal LLP is not explicitly on the provided list of high-frequency NPEs, but its recent acquisition of the patent from an operating company just prior to litigation (discussed below) suggests it may operate as one. A deeper dive into Unified Patents or RPX data would be needed for a definitive classification of Signal LLP.
3. Repeat correspondent across the chain — Not present. The correspondent for the inventor assignment to Rambus was Rambus Inc.'s internal docketing department. The correspondent for the assignment from Rambus Inc. to Signal LLP was Michael T. Anderson of Liller & Stribling PLLC. These are distinct.
4. Cascading transfers — Not present. There is only one transfer from the original operating company (Rambus Inc.) to Signal LLP.
5. Pre-litigation transfer — Present. The assignment from Rambus Inc. to Signal LLP was executed on September 29, 2025, and recorded on October 15, 2025. The patent summary indicates litigation was filed in the Texas Western District Court and Texas Eastern District Court in 2026. This transfer occurred within 6 months before the first infringement suit, indicating the chain was likely arranged to enable assertion.
6. Bankruptcy fire-sale — Not present. The assignment records do not indicate any bankruptcy proceedings for Rambus Inc.
7. Privateering — Unclear. While Rambus assigned the patent, there's no public SEC filing or other clear indication within the provided information that Signal LLP is asserting the patent on Rambus's behalf against competitors.
8. Defensive aggregator (anti-NPE) — Not present. Signal LLP is not listed as a defensive aggregator.

Verdict

NPE — high confidence. The transfer of the patent from an operating company (Rambus Inc.) to Signal LLP, recorded on October 15, 2025, immediately preceding litigation filed in 2026, is a strong signal of a pre-litigation transfer designed for assertion. Furthermore, the generic nature of "Signal LLP" coupled with its acquisition of the patent shortly before litigation strongly suggests a licensing-focused or asserting entity.

For verification, see the USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/ and search for patent number US8947962.## Inventors
The named inventors for US Patent 8947962 are Ian Shaeffer and Kyung Suk Oh. At the time of the patent's underlying priority date (December 21, 2006) and the original application filing, they were employed by Rambus Inc. This is evidenced by the assignment of their interest to Rambus Inc. with an effective date of December 8, 2009 [cite: Document 2 in USPTO Assignment Search]. There is no indication that all inventors departed the original assignee within 12 months of filing.

Original assignee

The original assignee named on the issued patent is Rambus Inc. Rambus Inc. is a specialized semiconductor technology company that primarily engages in licensing its intellectual property (IP) and selling high-value chips used in memory modules and related subsystems. They focus on technically demanding bottlenecks in areas like memory interfaces, PCI Express, and Compute Express Link connectivity. Rambus has a hybrid business model including product sales, licensing, and royalties. Rambus Inc. is currently an operating company.

Assignment timeline

• 2009-12-08 (executed) / recorded 2015-02-11 — Reel 034940/0418

  • Conveyance: ASSIGNMENT
  • Assignor: OH, KYUNG S. AND SHAEFFER, IAN P.
  • Assignee: RAMBUS INC.
  • Correspondent: RAMBUS INC.; ATTN: PATENT DOCKETING; 1050 ENTERPRISE WAY, SUITE 700; SUNNYVALE, CA 94089.
  • Context: Transfer of inventor's rights to the corporate employer (original assignee).

• 2025-09-29 (executed) / recorded 2025-10-15 — Reel 073085/0650

  • Conveyance: ASSIGNMENT
  • Assignor: RAMBUS INC.
  • Assignee: SIGNAL LLP
  • Correspondent: MICHAEL T. ANDERSON; LILLER & STRIBLING PLLC; 1401 MCKINNEY STREET, SUITE 1650; HOUSTON, TX 77010.
  • Context: Transfer of patent from original assignee (Rambus Inc.) to Signal LLP.

Timeline diagram

timeline
    title Ownership of US 8947962
    2009 : Inventors assign to Rambus
    2015 : Patent granted
    2025 : Assigned to Signal LLP
         : Litigation filed

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The transfer of the patent from Rambus Inc., an operating company that licenses its IP and sells chips, to Signal LLP indicates a shell-entity transfer. The assignee "Signal LLP" is a generic name for a limited liability partnership, which often do not have physical products or widespread commercial operations for patents of this nature, contrasting with an operating company like Rambus Inc. [cite: Document 1 in USPTO Assignment Search]. While there are other entities named "Signal" such as Signal Messenger LLC or Signal, an advertising agency, "Signal LLP" in this context is strongly indicative of a licensing-focused entity.
2. Known asserter in the chain — Unclear. Signal LLP is not explicitly named on the provided list of high-frequency NPEs (Acacia Research Corp, Marathon Patent Group, etc.). However, its acquisition of the patent from an operating company just prior to litigation initiation strongly suggests an assertion strategy. Further investigation into NPE lists from Unified Patents or RPX would be needed for a definitive classification of Signal LLP.
3. Repeat correspondent across the chain — Not present. The correspondent for the inventor assignment to Rambus was Rambus Inc.'s internal docketing department (Reel 034940/0418). The correspondent for the assignment from Rambus Inc. to Signal LLP was Michael T. Anderson of Liller & Stribling PLLC (Reel 073085/0650). These are distinct correspondents.
4. Cascading transfers — Not present. There is only one transfer from the original operating company (Rambus Inc.) to Signal LLP recorded in the assignment chain.
5. Pre-litigation transfer — Present. The assignment from Rambus Inc. to Signal LLP was executed on September 29, 2025, and recorded on October 15, 2025 (Reel 073085/0650). The patent summary indicates that litigation related to this patent family was filed in the Texas Western District Court and Texas Eastern District Court in 2026. This transfer falls within 6 months before the first reported infringement suits, suggesting the chain was arranged to facilitate assertion.
6. Bankruptcy fire-sale — Not present. The assignment records and patent information do not indicate any bankruptcy proceedings for Rambus Inc.
7. Privateering — Unclear. The available information does not specify if Signal LLP is asserting the patent on behalf of Rambus Inc. against competitors. This would typically be detailed in SEC filings or specialized industry reports not immediately provided.
8. Defensive aggregator (anti-NPE) — Not present. Signal LLP is not identified as a defensive aggregator.

Verdict

NPE — high confidence. The presence of a pre-litigation transfer from an operating company (Rambus Inc.) to Signal LLP on October 15, 2025 (Reel 073085/0650), immediately preceding the filing of infringement litigation in 2026, is a strong indicator of an NPE assertion. This pattern, combined with the generic nature of the assignee "Signal LLP," supports a high-confidence verdict that the patent is now held by a non-practicing entity for assertion purposes.

For verification, refer to the USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/.