DCT

5:21-cv-00267

Unicorn Global Inc v. DGI Product Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 5:21-cv-00267, C.D. Cal., 02/16/2021
  • Venue Allegations: Plaintiffs allege venue is proper for the California-based defendants as residents of the forum state, for the Walmart entities based on their regular and established places of business within the district, and for the foreign defendant (Yongkang) based on its alleged acts of infringement within the district.
  • Core Dispute: Plaintiffs allege that Defendants’ hoverboard products infringe two patents related to the mechanical structure and control systems of self-balancing vehicles.
  • Technical Context: The technology at issue concerns self-balancing personal transporters, commonly known as hoverboards, which utilize sensors and motors to maintain balance and respond to rider foot movements.
  • Key Procedural History: The complaint alleges that the Walmart defendants had pre-suit knowledge of the Asserted Patents via a written notice letter sent on April 2, 2019. It also alleges that other defendants had knowledge through their relationship with a defendant in a prior, related patent infringement case brought by the same Plaintiffs. Plaintiff Unicorn Global, Inc. asserts its rights under a patent license agreement dated October 16, 2018.

Case Timeline

Date Event
2014-06-13 ’347 Patent Earliest Priority Date
2015-10-12 ’286 Patent Earliest Priority Date
2018-10-16 Patent License Agreement Granting Rights to Unicorn
2019-04-02 Plaintiffs' Counsel Sent Infringement Notice to Walmart
2020-01-21 U.S. Patent 10,538,286 Issued
2020-06-30 U.S. Patent 10,696,347 Issued
2021-02-16 Complaint Filed

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

U.S. Patent No. 10,538,286, "Electric Balancing Swing Car," issued January 21, 2020

The Invention Explained

  • Problem Addressed: The patent’s background section states that prior art self-balancing cars required "many position sensors" and possessed a "complicated" structure, implying a need for a simpler, more cost-effective design (’286 Patent, col. 1:59-61).
  • The Patented Solution: The invention proposes a self-balancing vehicle with two independently rotatable platforms, where a single "position sensor" is disposed in only one of the platforms. This sensor is configured to detect two types of data: the tilt of the platform it is in relative to the ground, and the rotational movement of the second platform relative to the first (’286 Patent, Abstract; col. 2:11-20). A control device uses this combined information to drive both wheels, thereby simplifying the vehicle's internal circuitry and sensor requirements compared to designs that place sensor suites in both platforms (’286 Patent, col. 6:1-10).
  • Technical Importance: This approach sought to reduce the manufacturing cost and complexity of hoverboards by consolidating the sensing function into a single location within the device's frame (’286 Patent, col. 8:1-3).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2, 3, 4, 6, 11, 12, and 13 (Compl. ¶39).
  • Independent Claim 1 requires:
    • "supporting frameworks" with a first and second framework that are symmetrically disposed and moveable relative to each other
    • A "first wheel" and a "second wheel" connected to their respective frameworks
    • A "connecting device" fixed to the second framework and in a moveable connection with the first framework
    • A "position sensor" disposed in the first framework, configured to sense (a) the first framework's position relative to the ground and (b) the movement change of the second framework relative to the first
    • A "control device" that drives both wheels based on the information from the position sensor

U.S. Patent No. 10,696,347, "Electric Vehicle," issued June 30, 2020

The Invention Explained

  • Problem Addressed: The patent's background suggests a limitation in prior art devices where a user "cannot control the self-balancing vehicle merely through the feet," indicating a need for a more intuitive, foot-based control mechanism (’347 Patent, col. 1:42-44). The invention is presented as a solution to "overcome at least one defect in the prior art" (’347 Patent, col. 1:46-48).
  • The Patented Solution: The patent describes a specific mechanical architecture for an electric vehicle comprising a "housing" with two rotatable sides, an internal "support structure," pedals, wheels, motors, and a controller (’347 Patent, Abstract). A key feature is the multi-layer construction, including a top cover, a structural inner cover, and a bottom cover, which creates a robust frame and protected cavities for electronic components (’347 Patent, col. 2:50-67; Fig. 2). This integrated design allows the two halves of the vehicle to rotate relative to each other via a central rotating mechanism, enabling steering and motion control through the rider's foot movements on the pedals (’347 Patent, col. 10:1-10).
  • Technical Importance: This patent details a robust structural design for foot-controlled self-balancing vehicles that protects internal components while enabling the articulated movement necessary for steering, a design paradigm common in the consumer hoverboard market (’347 Patent, col. 3:20-29).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 10, and 15, as well as several dependent claims (Compl. ¶52).
  • Independent Claim 1 requires:
    • A "housing" with a first side rotatable relative to a second side
    • A "support structure" mounted within the housing
    • A "first pedal" and "second pedal"
    • A "rotating mechanism" allowing the support structure's components to rotate relative to each other
    • A "limiting shaft" to limit the rotation
    • A "first wheel" and "second wheel" attached to the support structure
    • Motors, a plurality of sensors, a power supply, and a controller that drives the motors based on sensor signals
  • The complaint also asserts Independent Claim 10, which further specifies that part of the support structure has a "first cylindrical barrel portion" containing the rotating mechanism, and Independent Claim 15, which requires both sides of the support structure to have cylindrical barrel portions (Compl. ¶¶ 58, 61).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies the accused products as "Hoverstar-" or "Hoverheart-" branded self-balancing vehicles, specifically models LBW14 and LBW12A (collectively, the "Accused Products") (Compl. ¶28).

Functionality and Market Context

  • The Accused Products are described as two-wheeled, self-balancing electric scooters controlled by the rider's movements (Compl. ¶¶ 26, 38). They are sold to consumers in the U.S. through online retailers including Amazon.com and Walmart.com (Compl. ¶¶ 28, 29). The complaint includes a product listing for a "HOVERSTAR Hoverboard" which notes features such as "Electronic Based Hoverboard, Very sturdy," "Impeccable Speed Controlled by Rider," and LED lights (Compl. ¶30, p. 8). A screenshot from an Alibaba.com storefront shows Defendant Yongkang offering similar "Balance Scooter" products for supply to other distributors (Compl. ¶31, p. 9).

IV. Analysis of Infringement Allegations

The complaint references exhibits (Ex. B, Ex. D) that are not attached to the filed document; the following analysis is based on the narrative infringement allegations in the complaint body.

’286 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
supporting frameworks, comprising a first supporting framework and a second supporting framework that are symmetrically disposed and moveable relative to each other The complaint alleges the Accused Products are "electric balancing swing cars" that possess supporting frameworks with these characteristics. A product listing screenshot shows a two-platform hoverboard design. (Compl. ¶30, p. 8). ¶40 col. 6:41-45
a first wheel, connected to the first supporting framework; a second wheel, connected to the second supporting framework The Accused Products are alleged to have a first and second wheel connected to their respective supporting frameworks. The product image confirms a two-wheeled structure. (Compl. ¶30, p. 8). ¶40 col. 6:50-54
a connecting device, extending from the second supporting framework... in a moveable connection to the first supporting framework The Accused Products are alleged to contain a connecting device that enables the two frameworks to move relative to each other. ¶40 col. 6:60-67
a position sensor, disposed in the first supporting framework and configured for sensing a first position information... and a movement change information... The Accused Products are alleged to have a position sensor that is disposed in the first supporting framework and is configured to sense both the tilt of the first framework and the relative rotation between the two frameworks. ¶40 col. 7:49-55
a control device, configured for driving the first wheel to rotate or move... and driving the second wheel to rotate or move... The Accused Products are alleged to possess a control device that drives both wheels based on the information gathered by the position sensor. ¶40 col. 7:30-34
  • Identified Points of Contention:
    • Scope Questions: The central dispute may concern the "position sensor" limitation. A question for the court will be whether the sensor system in the Accused Products constitutes a single "position sensor" as claimed. Another question is whether that sensor is "disposed in the first supporting framework" and performs the dual functions of sensing absolute tilt and relative rotation, as required by the claim.
    • Technical Questions: What evidence demonstrates that the Accused Products' control system operates based on a single sensor suite in one framework, rather than a different configuration (e.g., sensors in both frameworks)? The complaint's allegations on this point are conclusory and will require evidentiary support from technical analysis of the products.

’347 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a housing having a first side rotatable relative to a second side The Accused Products are alleged to be electric balance vehicles with a housing composed of two sides that can rotate relative to each other. A screenshot from Walmart.com shows a hoverboard with a central pivot. (Compl. ¶31, p. 9). ¶53 col. 10:9-24
a support structure mounted within the housing, the support structure comprising a plurality of structural components The Accused Products are alleged to have an internal support structure with multiple components mounted inside the outer housing. ¶53 col. 12:43-54
a first pedal disposed on the first side of the housing and a second pedal disposed on the second side of the housing The Accused Products are alleged to have first and second pedals on each side of the housing. The product images show foot platforms on each side of the device. (Compl. ¶30, p. 8). ¶53 col. 12:64-66
a rotating mechanism coupled with the support structure and configured to allow...structural components to rotate relative to the second... The Accused Products are alleged to contain a rotating mechanism that facilitates the relative rotation of the internal structural components. ¶53 col. 12:45-56
a limiting shaft disposed within the housing to limit rotation of the first side relative to the second side The Accused Products are alleged to have a limiting shaft inside the housing that restricts the degree of rotation between the two sides. ¶53 col. 12:65-67
a plurality of sensors; a power supply mounted within the housing; and at least one controller mounted within the housing The Accused Products are alleged to contain a plurality of sensors, a power supply, and at least one controller, all mounted within the housing, which work together to control the vehicle's motors. ¶53 col. 13:20-28
  • Identified Points of Contention:
    • Scope Questions: The infringement analysis will likely focus on whether the internal construction of the Accused Products maps onto the specific structural elements of the claims. For example, can the term "support structure" be construed to read on the internal frame of the Accused Products, and is it truly "mounted within" a separate "housing" as the claim requires?
    • Technical Questions: The complaint's allegations regarding internal components like the "support structure" and "limiting shaft" are not supported by visual evidence of the products' interiors. A key question will be whether discovery and product teardowns reveal a one-to-one correspondence between the accused internal components and the claimed structural elements, or if the accused design differs in a material way.

V. Key Claim Terms for Construction

For the ’286 Patent

  • The Term: "position sensor"
  • Context and Importance: Claim 1 requires "a position sensor" that performs two distinct functions: sensing the tilt of its host framework and sensing the relative rotation between the two frameworks. The interpretation of this term is critical because if it is construed to mean a single, integrated component, infringement may be avoided if the accused product uses separate, non-integrated sensors for these functions. Practitioners may focus on this term because the patent's asserted novelty rests on simplifying the device by using this dual-function sensor.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discloses that the "position sensor 40 specifically comprises a position sensing unit 41 and a movement change information sensing unit 42" (’286 Patent, col. 7:60-62). This could support an interpretation where "a position sensor" refers to a system or collection of co-located units rather than a single physical device.
    • Evidence for a Narrower Interpretation: The use of the singular "a position sensor" in the claim itself could support a narrower reading. A defendant may argue that the specification's description of separate "units" (e.g., a gyroscope for tilt and a Hall sensor for rotation) implies distinct components, and the claim requires them to be unified into a single "sensor."

For the ’347 Patent

  • The Term: "support structure"
  • Context and Importance: Claim 1 recites "a support structure mounted within the housing." The patent specification appears to equate this "support structure" with the "inner cover" of its three-layer design (’347 Patent, col. 11:10, 12:20-23). The infringement case depends on whether the internal frame of the Accused Products meets this definition. Practitioners may focus on this term because a variance in the fundamental chassis design could be a basis for a non-infringement argument.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term itself is general. Plaintiffs could argue that any internal frame that bears the load of the rider and provides mounting points for the wheels and electronics qualifies as a "support structure," and the decorative plastic shell is the "housing."
    • Evidence for a Narrower Interpretation: The patent consistently describes a specific three-part framework: a top cover, an inner cover, and a bottom cover (’347 Patent, col. 11:9-12). A defendant could argue that "support structure" is implicitly limited to the "inner cover" of this specific layered assembly and does not read on products with a different type of chassis, such as a unibody frame that integrates structural and housing functions.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendant Yongkang infringes by supplying the Accused Products to its co-defendants and other distributors in the United States (Compl. ¶31). The prayer for relief seeks a judgment for both direct and indirect infringement, including inducement (Compl. p. 21, ¶A, B).
  • Willful Infringement: The complaint alleges that the Walmart defendants had pre-suit actual knowledge of the Asserted Patents and their infringement since at least April 2, 2019, based on a written notice letter sent by Plaintiffs' counsel (Compl. ¶¶ 34, 68). For the other defendants, the complaint alleges knowledge based on their relationship to a defendant in a prior patent case filed by Plaintiffs (Compl. ¶36). The complaint asserts that Defendants’ continued infringement despite this knowledge is willful (Compl. ¶¶ 69-70).

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

  1. A core issue for the '286 Patent will be one of functional scope: can the term "a position sensor" be construed to cover the accused product's sensor arrangement, and does that arrangement in fact perform the dual-function of sensing both absolute device tilt and relative platform rotation as the claim requires?
  2. A central question for the '347 Patent will be one of structural mapping: does the internal assembly of the accused hoverboards contain discrete components that correspond to the patent's claimed "support structure mounted within the housing" and "limiting shaft," or will a technical analysis reveal a fundamentally different and non-infringing mechanical design?
  3. A key issue impacting potential damages will be one of knowledge and intent: can Plaintiffs prove that the defendants, particularly the Walmart entities, had actual knowledge of the patents and infringement as of April 2019, making their subsequent sales acts of willful infringement subject to enhanced damages?