DCT
8:25-cv-00786
Mr Tech GmbH v. Toshiba America Electronic Components Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Mr Technologies GmbH (Austria)
- Defendant: Toshiba America Electronic Components, Inc. (California) and TOSHIBA ELECTRONICS DEVICES AND STORAGE CORPORATION (Japan)
- Plaintiff’s Counsel: Russ August & Kabat
- Case Identification: 8:25-cv-00786, C.D. Cal., 04/15/2025
- Venue Allegations: Venue is alleged to be proper in the Central District of California because Defendant Toshiba America Electronic Components, Inc. has transacted business and committed acts of infringement in the District, and Defendant TOSHIBA ELECTRONICS DEVICES AND STORAGE CORPORATION is a foreign corporation.
- Core Dispute: Plaintiff alleges that Defendants’ perpendicular magnetic recording (PMR) hard disk drives (HDDs) infringe three patents related to multilayer exchange spring recording media technology.
- Technical Context: The technology addresses the "superparamagnetic limit" in magnetic storage by using a multilayer media with graded magnetic properties to enable higher data density while maintaining the ability to write data reliably.
- Key Procedural History: The complaint heavily references a prior lawsuit filed by the Plaintiff against Western Digital (MRT-I), which resulted in a July 2024 jury verdict finding two of the same patents-in-suit (’864 and ’997) infringed and not invalid, with a substantial damages award. The complaint also alleges that Plaintiff provided notice to Defendants in March 2012 by sending the patent applications that led to the asserted patents.
Case Timeline
| Date | Event |
|---|---|
| 2006-05-01 | Dr. Suess's alleged timeframe of discovery |
| 2006-06-17 | Earliest Priority Date for '864, '997, and ’734 Patents |
| 2012-03-21 | Plaintiff allegedly sends parent applications to Toshiba |
| 2018-03-27 | U.S. Patent No. 9,928,864 Issues |
| 2021-10-05 | U.S. Patent No. 11,138,997 Issues |
| 2024-06-25 | U.S. Patent No. 12,020,734 Issues |
| 2024-07-26 | Jury verdict in MR Techs. v. Western Digital (MRT-I) |
| 2024-08-14 | Court enters judgment in MRT-I |
| 2025-04-15 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,928,864 - “Multilayer exchange spring recording media”
Issued March 27, 2018
The Invention Explained
- Problem Addressed: The patent describes a fundamental challenge in hard disk drive technology known as the "superparamagnetic limit." As magnetic bits (grains) are made smaller to increase data density, they risk becoming thermally unstable, causing data loss. A conventional solution—increasing the magnetic "hardness" (anisotropy) to stabilize the grains—makes it prohibitively difficult to write new data with existing recording heads (Compl. ¶11; ’864 Patent, col. 1:11-28).
- The Patented Solution: The invention proposes a multilayer magnetic medium that decouples thermal stability from writability. It consists of a magnetically "hard" storage layer, which ensures data stability, and an adjacent "nucleation host." This host is composed of multiple, softer ferromagnetic layers where the anisotropy is graded—it systematically increases in the layers closer to the hard storage layer. This structure lowers the overall magnetic field required to write data (the coercive field) without sacrificing the thermal stability of the underlying hard layer, a concept the complaint notes was contrary to conventional wisdom (Compl. ¶¶11, 13; ’864 Patent, Abstract, col. 2:50-65).
- Technical Importance: This "exchange spring" media architecture allegedly enabled the industry to overcome a critical roadblock, unlocking significant increases in areal data density from approximately 200 Gb/in² to over 1 Tb/in² (Compl. ¶¶16, 20).
Key Claims at a Glance
- The complaint focuses its allegations on independent claim 1 (Compl. ¶30).
- Essential elements of Claim 1 include:
- A magnetic recording medium comprising an essentially non-magnetic substrate and an underlayer.
- An exchange coupled magnetic multilayer structure that includes a hard magnetic storage layer and a nucleation host.
- The hard magnetic storage layer has a first coercive field (Hs) greater than 0.5 Tesla.
- The nucleation host has a second coercive field (Hn) that is lower than the first (Hn<Hs).
- The nucleation host is formed on the hard magnetic storage layer and is exchange coupled to it.
- Crucially, the nucleation host "comprises ferromagnetic layers with increasing anisotropy constant K from layer to layer."
U.S. Patent No. 11,138,997 - “Multilayer exchange spring recording media”
Issued October 5, 2021
The Invention Explained
- Problem Addressed: The ’997 Patent addresses the same superparamagnetic limit challenge as its parent, the ’864 Patent (Compl. ¶11; ’997 Patent, col. 1:11-28).
- The Patented Solution: The patent claims the same core technological solution: a multilayer magnetic structure with a hard storage layer and a softer nucleation host with graded anisotropy (’997 Patent, Abstract, col. 2:50-65). The primary distinction is that the ’997 Patent claims a complete "magnetic recording system" that explicitly includes the "writing head" in addition to the disk containing the specialized medium, whereas the ’864 Patent claims the medium itself (’997 Patent, Claim 1).
- Technical Importance: The invention's importance is identical to that of the ’864 Patent, as it protects the application of the same fundamental media structure within a functional hard drive system (Compl. ¶¶16, 17).
Key Claims at a Glance
- The complaint focuses its allegations on independent claim 1 (Compl. ¶62).
- Essential elements of Claim 1 include:
- A magnetic recording system comprising a writing head and a disk.
- The disk includes a magnetic recording medium with a non-magnetic substrate and an underlayer.
- The medium contains an exchange coupled multilayer structure with a hard magnetic storage layer and a nucleation host.
- The limitations for the hard layer (Hs > 0.5 T), nucleation host (Hn < Hs), physical arrangement, exchange coupling, and the requirement of "ferromagnetic layers with increasing anisotropy constant K from layer to layer" are structurally identical to those in claim 1 of the ’864 Patent.
U.S. Patent No. 12,020,734 - “Multilayer exchange spring recording media”
Issued June 25, 2024
- Patent Identification: U.S. Patent No. 12,020,734, “Multilayer exchange spring recording media,” issued June 25, 2024 (Compl. ¶73).
- Technology Synopsis: The ’734 Patent, a continuation of the same family, also claims a magnetic recording system that uses the exchange spring principle to overcome the superparamagnetic limit. It describes a hard storage layer coupled to a nucleation host with graded anisotropy to balance thermal stability and writability (’734 Patent, Abstract; Compl. ¶77).
- Asserted Claims: The complaint focuses on independent claim 1 (Compl. ¶77).
- Accused Features: The complaint alleges that claim 1 of the ’734 Patent is substantially similar to claim 1 of the ’997 Patent, but adds a more specific requirement that "at least two ferromagnetic layers are exchange coupled with an exchange coupling layer." The complaint alleges the accused products meet this additional limitation, citing diagrams that depict such layers (Compl. ¶77, Fig. at ¶31).
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are a wide range of Defendants' perpendicular magnetic recording (PMR) hard disk drives (HDDs) and the PMR media they contain. This includes, but is not limited to, the Consumer (S300, X300, Canvio series), Enterprise (MG series), and Internal Specialty (MD04, DT02 series) HDDs (Compl. ¶¶2, 24).
Functionality and Market Context
The complaint alleges that the accused HDDs employ the patented technology to achieve high data storage densities (e.g., above 700 Gb/in2) (Compl. ¶21). The core of the infringement allegation is that these drives incorporate a multilayer magnetic medium comprising a hard storage layer and a multilayered "nucleation host" with increasing anisotropy toward the hard layer, which lowers the coercive field to assist in writing data (Compl. ¶¶11, 21). The complaint asserts this technology is not just an incidental feature but is foundational to modern PMR media and necessary for Defendants to compete in the three-player HDD market (Compl. ¶¶19, 27, 33). The complaint includes a diagram to illustrate the alleged structure of the accused products' media. This diagram shows a "nucleation host" with an "Overall Increase" in anisotropy (from "Lower K" to "Higher K") situated between the write field and a "hard storage layer." (Compl. ¶21, Fig. at ¶21).
IV. Analysis of Infringement Allegations
’864 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A magnetic recording medium | The Accused Products include at least one disk that comprises a perpendicular magnetic recording (PMR) medium. A photo of an HDD read/write head assembly is provided as an example. | ¶34 | col. 13:21-23 |
| an essentially non-magnetic substrate | The Accused Products allegedly include a non-magnetic glass or AlMg substrate. | ¶35 | col. 13:24-25 |
| an underlayer formed on the non-magnetic substrate | The Accused Products include a soft magnetic underlayer (SUL) formed on the substrate. The complaint references a TEM image of a typical PMR media layer structure to support this. | ¶36 | col. 13:26-27 |
| a hard magnetic storage layer, having a first coercive field Hs>0.5 T, formed on the underlayer | The Accused Products are alleged to have a hard magnetic storage layer made of a CoCrPt or similar alloy, with a coercive field of approximately 2.0 T, which is >0.5 T. | ¶¶39, 41 | col. 13:31-33 |
| a nucleation host, having a second coercive field Hn...lower than the first coercive field, Hn<Hs | The Accused Products allegedly include a nucleation host with a coercive field (Hn) that is lower than the coercive field of the hard layer (Hs), specifically alleging Hn is <1.8 T while Hs is ~2.0 T. | ¶¶43, 44, 46 | col. 13:34-37 |
| said nucleation host is formed on the hard magnetic storage layer such that the hard magnetic storage layer is between the nucleation host and the non-magnetic substrate | The complaint alleges the nucleation host is formed on the hard storage layer, which is between the host and the substrate. A diagram illustrates this stacking order, with the write head interacting first with the nucleation host. | ¶47 | col. 13:38-41 |
| [said nucleation host] is exchange coupled to the hard magnetic storage layer | The complaint alleges the layers interact through exchange coupling, citing a court construction from a prior case and industry publications describing the "exchange spring effect." | ¶¶37, 47 | col. 13:42-43 |
| [said nucleation host] comprises ferromagnetic layers with increasing anisotropy constant K from layer to layer | The accused products are alleged to have a nucleation host with two or more ferromagnetic layers where the anisotropy constant K increases in layers closer to the hard magnetic storage layer, creating an overall increase. | ¶¶48, 49 | col. 13:44-46 |
’997 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A magnetic recording system, comprising: a writing head; and a disk | The Accused Products are hard disk drives, which are PMR systems that inherently contain a writing head and a disk. An illustrative photo of an HDD is provided. | ¶66 | col. 13:58-60 |
| including a magnetic recording medium, comprising... | The complaint alleges that the magnetic recording medium elements recited in claim 1 of the '997 patent are met for the same reasons as claim 1 of the '864 patent, incorporating the prior analysis by reference. | ¶67 | col. 13:60-61 |
| [All subsequent medium limitations] | The allegations for the substrate, underlayer, hard storage layer, and nucleation host (including its structure, properties, and graded anisotropy) are identical to those asserted against the '864 Patent, as described above. | ¶67 | col. 13:62-col. 14:17 |
Identified Points of Contention
- Scope Questions: The infringement case may turn on the precise interpretation of relative and quantitative terms. A question for the court will be how to measure and compare the "coercive field" (Hs vs. Hn) of the respective layers and whether the accused products meet the claimed Hn<Hs relationship under that methodology (Compl. ¶¶44-46). Another scope question is whether the structure in the accused products constitutes "ferromagnetic layers with increasing anisotropy constant K from layer to layer," especially given the prior court construction allowing for an "overall increase" rather than a strictly monotonic one (Compl. ¶48).
- Technical Questions: The complaint relies heavily on evidence from industry presentations, scientific papers, and testimony from prior litigation against a different defendant (Compl. ¶¶14, 17, 19, 36). A primary technical question will be one of proof: what direct evidence demonstrates that Toshiba’s specific material stacks have the physical structure and magnetic properties (e.g., graded anisotropy, exchange coupling) required by the claims, as opposed to merely following a general industry trend?
V. Key Claim Terms for Construction
The Term: "ferromagnetic layers with increasing anisotropy constant K from layer to layer"
- Context and Importance: This phrase is the technological core of the asserted claims. The interpretation of "increasing...from layer to layer" will determine whether a strict, monotonic increase is required or if an "overall" or "graded" increase suffices. The complaint cites a construction from the MRT-I case that adopted the latter, broader view, stating the host can have "plateaus or decreasing anisotropy...so long as there is an overall increase toward the hard storage layer" (Compl. ¶48). This construction is critical to encompassing real-world manufacturing variations.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification describes a general principle where increasing the number of layers in the nucleation host reduces the coercive field, suggesting the overall structural effect is what matters (’864 Patent, col. 3:14-20). The detailed description refers to the host having a "spatially varying anisotropy K(z)," which supports a graded, rather than strictly stepwise, function (’864 Patent, col. 6:6-8).
- Evidence for a Narrower Interpretation: The plain language of the claim itself—"increasing...from layer to layer"—could be argued to imply a consecutive, stepwise increase between each adjacent layer. The abstract also uses the phrase "the anisotropy increases from layer to layer," which could be used to support a more restrictive meaning (’864 Patent, Abstract).
The Term: "nucleation host"
- Context and Importance: This term defines the "softer" portion of the claimed media responsible for facilitating the writing process. The boundary between the "nucleation host" and the "hard magnetic storage layer" is crucial for determining if the "increasing anisotropy" limitation is met. Practitioners may focus on this term because the Defendants could argue that layers the Plaintiff identifies as part of the "host" are functionally part of the "hard layer," thereby defeating the infringement allegation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the nucleation host as a distinct component from the hard storage layer, for example, as a "special multilayer host layer" (’997 Patent, col. 2:52-53). It is functionally defined by its role in reducing the coercive field while being "strongly exchange coupled" to the hard layer (’997 Patent, Abstract).
- Evidence for a Narrower Interpretation: The patent states that in some embodiments, the coercive field of the "nucleation host" can be half that of the "hard magnetic storage layer," suggesting a significant and measurable difference in magnetic properties defines the two structures, which could support a narrower definition of what layers qualify as part of the "host" (’864 Patent, col. 5:26-29).
VI. Other Allegations
Indirect Infringement
The complaint alleges induced infringement under 35 U.S.C. § 271(b). It asserts Defendants had knowledge of the patents based on a 2012 communication and, more significantly, from the highly publicized 2024 jury verdict against competitor Western Digital on the same patents (Compl. ¶¶28-29, 58, 61). It alleges Defendants intend for customers and OEMs to infringe by designing, marketing, and selling HDDs with documentation and specifications that instruct on their use in computer systems imported into and sold in the U.S. (Compl. ¶¶30, 31).
Willful Infringement
The willfulness allegations are prominent and based on both pre- and post-suit knowledge. The complaint alleges pre-suit knowledge dating back to a March 21, 2012 communication where the parent applications were allegedly sent to Toshiba (Compl. ¶28). It further alleges that Defendants have been on notice of their infringement since at least July/August 2024, when the verdict in the Western Digital case was widely reported, and that continued infringement thereafter is willful (Compl. ¶¶33, 65, 84). The complaint also asserts willfulness on the basis that Defendants know they must use the patented technology to remain competitive in the market (Compl. ¶33).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of evidentiary proof: The complaint constructs a compelling narrative of industry-wide adoption based on prior litigation and technical publications. The key question for the court is whether the Plaintiff can produce direct evidence, likely through discovery and reverse engineering, to demonstrate that Toshiba’s specific products possess the precise physical structures and meet the quantitative magnetic property limitations (e.g., Hn < Hs, K increasing "from layer to layer") required by the asserted claims.
- A key legal question will be the application of prior judicial findings: The Plaintiff heavily relies on the outcomes of its litigation against Western Digital, including claim constructions and a jury verdict. A pivotal issue will be to what extent, if any, the court in this case adopts the claim constructions from the prior litigation and how much weight is given to the prior verdict in assessing issues like knowledge and willfulness.
- A critical question for damages will be the timing of willful infringement: Given the allegations of pre-suit notice in 2012 and the widespread publicity of the 2024 verdict against a direct competitor, a core dispute will be determining the date from which Toshiba knew or should have known its conduct constituted infringement, which will be dispositive for any potential enhancement of damages.