Levitation Arts Inc v. Plox Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Levitation Arts, Inc. (Illinois)
  • Defendant: Plox, Inc. (Delaware)
  • Plaintiff’s Counsel: Farnan LLP
• Case Identification: 1:17-cv-01476, D. Del., 10/18/2017
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Plox, Inc. is a Delaware corporation.
• Core Dispute: Plaintiff alleges that Defendant’s "Official Star Wars Levitating Death Star Speaker" infringes a patent related to magnetic levitation apparatuses.
• Technical Context: The technology concerns systems that use a combination of static permanent magnets and actively controlled electromagnets to stably levitate an object.
• Key Procedural History: Plaintiff alleges it provided Defendant with pre-suit notice of infringement via a letter on July 12, 2017, which included a copy of the patent and a claim chart. The patent-in-suit, U.S. Patent No. 7,505,243, was the subject of an ex parte reexamination, which concluded with a certificate issued on October 4, 2011, confirming the patentability of all original claims 1-25.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,505,243 - “Magnetic Levitation Apparatus”

The Invention Explained

• Problem Addressed: The patent background explains that under Earnshaw's theorem, it is impossible to achieve stable levitation of a magnet using only static magnetic fields (’243 Patent, col. 1:22-28). It further notes that some prior art active stabilization systems apply torque that can cause undesirable "torsional and translational oscillation," which adversely affects stability (’243 Patent, col. 1:40-52).
• The Patented Solution: The invention proposes an apparatus that uses a set of magnets to generate a static magnetic field, creating an equilibrium point for a levitating magnetic element. This static field is stable in some directions but unstable in at least one direction (e.g., the x-axis) (’243 Patent, col. 2:40-50). A control system, comprising a position sensor and one or more electromagnets, then actively counteracts any movement along the unstable axis to maintain stable levitation, while being designed to minimize destabilizing field components at the equilibrium location (’243 Patent, col. 2:6-17; Fig. 1B).
• Technical Importance: The patent describes a need for magnetic levitation systems that have improved stability and can be constructed with a "reduced amount of magnetic material" at a "relatively low cost" (’243 Patent, col. 1:56-58).

Key Claims at a Glance

• The complaint asserts independent claims 16 and 25.
• Independent Claim 16 requires, in essence:
  • A "ring magnet" generating a static magnetic field at an equilibrium location.
  • The static field has a "substantially minimized magnetic field gradient" in the direction orthogonal to the ring magnet's plane.
  • A "position sensor" generating a feedback signal.
  • An "electromagnet" generating a control field.
  • A "controller" that uses the feedback signal to control the electromagnet.
• Independent Claim 25 requires, in essence:
  • A "ring magnet" generating a static magnetic field at an equilibrium location.
  • The static field has "substantially no gradient" in the direction orthogonal to the ring magnet's plane.
  • A "position sensor" generating a feedback signal.
  • "First and second electromagnets" disposed within the ring magnet.
  • A "controller" that uses the feedback signal to control the electromagnets.
• The complaint reserves the right to assert other claims, including dependent claims 17, 19, 20, 21, 22, 23, and 24 (Compl. ¶12).

III. The Accused Instrumentality

Product Identification

The accused product is Plox’s Bluetooth-enabled "Official Star Wars Levitating Death Star Speaker," including at least the PLX-SW-DS version (Compl. ¶¶10-11).

Functionality and Market Context

The product consists of a base unit and a separate speaker orb, designed to look like the Death Star, that "levitates in mid-air above the base" (Compl. ¶13.a). The complaint includes several annotated photographs of the product's internal components, alleging the base contains a ring magnet, a position sensor system, four electromagnets, and a controller to achieve levitation (Compl. ¶¶13.b, 13.e, 13.f, 13.g). One such image depicts the product's levitating orb above its base (Compl. ¶10).

IV. Analysis of Infringement Allegations

’243 Patent Infringement Allegations (Claim 16)

’243 Patent Infringement Allegations (Claim 25)

Identified Points of Contention

• Scope Questions: A central dispute may arise from the differing claim language between "substantially minimized magnetic field gradient" (Claim 16) and "substantially no gradient" (Claim 25). The complaint relies on the same factual allegation (¶13.d) to meet both limitations, which raises the question of whether the accused product’s gradient is low enough to satisfy the potentially stricter "substantially no gradient" requirement of Claim 25.
• Technical Questions: The complaint provides static, annotated photographs of the product’s internal components (e.g., Compl. ¶15.b). A key factual question for the court will be whether discovery and expert testing confirm that these components dynamically operate as a closed-loop feedback system as required by the claims (i.e., that the sensor detects displacement and causes the controller to energize the electromagnets to apply a corrective force).

V. Key Claim Terms for Construction

The Term: "ring magnet"

• Context and Importance: Asserted dependent claim 17 requires a "unitary ring magnet," and the complaint alleges the accused product has one (Compl. ¶14.b). This suggests a patentable distinction between a "ring magnet" in general and a "unitary" one. Practitioners may focus on this term because the defendant could argue its magnet is not "unitary," or that the term is ambiguous, potentially limiting damages to non-unitary embodiments or invalidating the dependent claim.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Claim 4, which depends from claim 1, describes an apparatus where the magnets "comprise a plurality of discrete dipoles arranged in a ring formation" (’243 Patent, col. 10:50-52). This suggests the general term "ring magnet" could encompass an assembly of separate magnets.
  • Evidence for a Narrower Interpretation: The doctrine of claim differentiation suggests that because dependent claim 17 adds the "unitary" limitation, the scope of independent claim 16 must be broader and not limited to unitary rings. However, the term "unitary ring magnet" itself implies a single, continuous, one-piece structure, which could be argued as the plain and ordinary meaning.

The Term: "substantially no gradient"

• Context and Importance: This term from independent claim 25 is critical for infringement, as it appears more restrictive than the "substantially minimized" language in claim 16. The plaintiff's ability to prove infringement of claim 25 will depend on the construction of this term.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The word "substantially" provides some latitude, suggesting the gradient need not be mathematically zero. The plaintiff may argue it means "effectively zero" or "immeasurable" for the purposes of the invention's stability.
  • Evidence for a Narrower Interpretation: The specification provides a potentially analogous definition when discussing additional magnets: "at equilibrium location 13, dB(30)z/dz=0" (’243 Patent, col. 8:60-62). A defendant could argue this establishes a clear intent to require a gradient that is mathematically zero, a standard the accused product may not meet.

VI. Other Allegations

Indirect Infringement

The complaint does not contain specific factual allegations to support claims of induced or contributory infringement.

Willful Infringement

Willfulness is alleged based on pre-suit knowledge. The complaint states that on July 12, 2017, Plaintiff sent Defendant a notice letter that included a hardcopy of the ’243 patent, a link to its prosecution history, and an element-by-element claim chart alleging infringement. The complaint alleges that Defendant's infringement persisted after receiving this notice (Compl. ¶23).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of claim construction and scope: can the phrase "substantially no gradient" in Claim 25 be proven to read on the accused device, or is its gradient merely "substantially minimized" as required by Claim 16? The resolution of this question will significantly impact the scope of potential infringement.
• A key evidentiary question will be one of operational proof: beyond the static photographs provided, what evidence will demonstrate that the accused product's sensor, controller, and electromagnets actually perform the dynamic, closed-loop feedback and stabilization functions recited in the asserted claims?