DCT

2:23-cv-05588

Hoshizaki America Inc v. Blue Air Fse LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-05588, C.D. Cal., 07/12/2023
  • Venue Allegations: Venue is alleged to be proper as Defendant Blue Air is a California corporation with a regular and established place of business in the district, and Defendant Bluenix is a foreign corporation subject to personal jurisdiction within the district.
  • Core Dispute: Plaintiff alleges that Defendants’ commercial icemaking machines infringe three U.S. patents related to the design and construction of energy-efficient evaporator plate assemblies.
  • Technical Context: The technology concerns the design of evaporator plates within commercial ice machines, a market where manufacturing cost, energy efficiency, and operational reliability are significant competitive factors.
  • Key Procedural History: The complaint alleges that Defendants had pre-suit knowledge of the patents-in-suit. Specifically, it states that during the prosecution of a U.S. patent application assigned to Defendant Bluenix, Plaintiff's '538 patent was cited in an Information Disclosure Statement and the '785 patent was cited as prior art by the USPTO. The complaint also details a cease-and-desist letter sent to Defendants months prior to the lawsuit, which allegedly went unanswered.

Case Timeline

Date Event
2012-09-10 Earliest Priority Date for '538, '785, and '692 Patents
2018-04-16 Defendant Bluenix (as Daeyeong) files its '396 patent application
2018-07-11 '538 Patent cited in IDS against Bluenix’s '396 application
2018-10-23 '538 Patent Issues
2018-10-30 '785 Patent Issues
2019-08-26 USPTO cites '785 Patent against Bluenix’s '396 application
2019-10-29 '692 Patent Issues
2023-02-01 Accused Products exhibited at NAFEM Show (approximate date)
2023-02-21 Plaintiff sends Cease-and-Desist Letter to Defendant Blue Air
2023-03-02 Defendant Blue Air confirms receipt of C&D letter to Plaintiff
2023-07-12 Complaint Filed

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

U.S. Patent No. 10,107,538 - "Ice Cube Evaporator Plate Assembly"

  • Patent Identification: U.S. Patent No. 10,107,538, titled “Ice Cube Evaporator Plate Assembly,” issued October 23, 2018 (’538 Patent). (Compl. ¶8; ’538 Patent).

The Invention Explained

  • Problem Addressed: The patent describes conventional evaporator manufacturing, which uses tin-plated copper tubes, as an expensive, time-consuming process involving potentially hazardous chemicals that can result in corrosion and reduced product lifespan. (’538 Patent, col. 2:3-29).
  • The Patented Solution: The invention proposes an evaporator assembly made of two plates, preferably stainless steel, with a serpentine refrigerant tube sandwiched between them. The plates are formed with "dimples" that create ice-forming locations. During assembly, the dimples are pressed around the tubing, crushing it into an oval shape to create a tight fit and increase the surface area for heat transfer, thereby improving efficiency and simplifying manufacturing. (’538 Patent, Abstract; col. 6:7-22).
  • Technical Importance: This design offered a potential manufacturing alternative to traditional brazed copper and tin-plated components, aiming to reduce costs, eliminate certain chemical processes, and improve the durability of the final product. (’538 Patent, col. 7:15-34).

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶27).
  • Essential elements of claim 1 include:
    • An evaporator plate with opposing front and rear surfaces, defining a plurality of dimples arranged in rows and columns.
    • A plurality of fins projecting from the front surface, separating the columns of dimples.
    • A serpentine tubing coil with straight portions connected by connecting portions.
    • The tubing coil in contact with the rear surface of the plate.
    • A first straight portion of the tubing coil disposed between a first and second row of dimples, and a second straight portion disposed between a third and fourth row of dimples.

U.S. Patent No. 10,113,785 - "Ice Making Machine and Ice Cube Evaporator"

  • Patent Identification: U.S. Patent No. 10,113,785, titled “Ice Making Machine and Ice Cube Evaporator,” issued October 30, 2018 (’785 Patent). (Compl. ¶10; ’785 Patent).

The Invention Explained

  • Problem Addressed: The patent identifies challenges in evaporator design, including the risk of corrosion where plate components abut and the potential for inefficient heat transfer if gaps exist between the refrigerant conduit and the plate surfaces. (’785 Patent, col. 2:30-49).
  • The Patented Solution: This invention discloses an evaporator structure with two distinct types of ice-forming locations: "active cavities" through which the refrigerant conduit passes, and "passive cavities" through which it does not. The front and rear plates are designed such that the conduit is in direct thermal contact with the active cavities, while flat portions between the cavities are slightly spaced apart to mitigate corrosion. (’785 Patent, Abstract; col. 2:1-9).
  • Technical Importance: By creating thermally distinct active and passive zones, the design allows for more refined control over the ice formation process and addresses manufacturing tolerance issues, while aiming to prevent corrosion at contact points between the plates. (’785 Patent, col. 5:7-15).

Key Claims at a Glance

  • The complaint asserts independent claims 1 (an apparatus) and 16 (a system). (Compl. ¶¶43, 53).
  • Essential elements of claim 1 include:
    • A refrigerant conduit.
    • Front and rear plates sandwiching the conduit, each plate having: inner flat portions spaced from the corresponding portions on the other plate; a set of first protrusions defining an "active cavity" through which the conduit extends; and a set of second protrusions defining a "passive cavity" through which the conduit does not extend.
    • The active and passive cavities are interspersed and separated by the inner flat portions to define a plurality of ice forming sites.
  • Claim 16 recites an ice making system comprising the evaporator of claim 1, a refrigerant system to circulate refrigerant, and a source of water to form ice on the evaporator.

U.S. Patent No. 10,458,692 - "Ice Making Machine and Ice Cube Evaporator"

  • Patent Identification: U.S. Patent No. 10,458,692, titled “Ice Making Machine and Ice Cube Evaporator,” issued October 29, 2019 (’692 Patent). (Compl. ¶11; ’692 Patent).
  • Technology Synopsis: As a continuation of the application that led to the '785 Patent, this patent shares the same specification and builds on the concept of an evaporator with distinct active and passive cavities. The claims focus on the specific alternating pattern of these cavities and the structural relationship between them, which together define the ice-forming sites on the evaporator plates. (Compl. ¶11; ’692 Patent, Abstract; col. 9:12-29).
  • Asserted Claims: The complaint asserts independent claims 1 and 11. (Compl. ¶¶60, 70).
  • Accused Features: The evaporator assemblies within the accused icemaking machines are alleged to possess the claimed structure, including the interspersed active cavities (containing the refrigerant conduit) and passive cavities (lacking the conduit) arranged in an alternating pattern. (Compl. ¶¶60, 70, Exhibit G).

III. The Accused Instrumentality

  • Product Identification: The complaint identifies the BLMI-500A and BLMI-900A icemaking machines as the primary "Accused Products," and notes that other models in the BLMI and BLUI series are also believed to infringe. (Compl. ¶16, n.1).
  • Functionality and Market Context:
    • The Accused Products are commercial icemaking machines that produce "crescent cuber" style ice. (Compl. ¶16, n.1). The complaint alleges that Plaintiff obtained and inspected physical specimens of the Accused Products and determined their internal evaporator assemblies are "identical in design, except for size." (Compl. ¶17, n.1). An image of the accused Blue Air BLMI-500A icemaking machine is provided to identify the product at issue. (Compl. ¶16, p. 6).
    • The complaint alleges that Defendants are leveraging Hoshizaki's patented technology and R&D investments to compete in the market. (Compl. ¶16).

IV. Analysis of Infringement Allegations

The complaint references, but does not include, Exhibits D, F, and G, which are described as claim charts mapping the asserted claims to photographs of the Accused Products. (Compl. ¶17, n.1). The following summarizes the infringement theories as described in the body of the complaint.

  • '538 Patent Infringement Allegations
    The complaint alleges that the Accused Products directly infringe at least claim 1 of the '538 patent. (Compl. ¶27). The narrative theory is that the evaporator assembly within the accused machines contains all elements of the claim, including a plate with vertically extending fins, multiple rows of ice-forming dimples, and a serpentine refrigerant tube that passes between specific rows of those dimples in the claimed configuration. (Compl. ¶¶16, 27). An image of Plaintiff's Hoshizaki KM-1100MAJ50 icemaking machine is presented as an example of a product covered by the patents-in-suit. (Compl. ¶15, p. 5).

  • '785 Patent Infringement Allegations
    The complaint alleges that the Accused Products directly infringe at least apparatus claim 1 and system claim 16 of the '785 patent. (Compl. ¶¶43, 53). The infringement theory is that the accused evaporator is constructed with front and rear plates that form both "active" cavities (containing the refrigerant conduit) and "passive" cavities (from which the conduit is absent), with these cavities interspersed as required by the claims. (Compl. ¶¶43, 53). For system claim 16, the complaint alleges contributory infringement, positing that the Accused Products are a material component of an infringing system that has no substantial non-infringing use and are combined with a water source by end-users per Defendants' instructions. (Compl. ¶53).

  • Identified Points of Contention:

    • Technical Questions: A primary technical question will be whether the accused evaporators actually embody the specific structures of the claims. For the ’785 and '692 patents, this requires determining if there is a clear, functional distinction between "active" and "passive" cavities, or if all cavities are cooled in a substantially similar manner that falls outside the claim scope. For the ’538 patent, the analysis will focus on whether the accused device meets the specific geometric arrangement of dimple rows and the path of the serpentine tubing.
    • Scope Questions: The claims of the ’785 and '692 patents require "active and passive cavities" to be "interspersed and separated by respective inner flat portions." The interpretation of "interspersed" and "separated" may become a focal point, as it defines the required physical relationship between the different types of cavities.

V. Key Claim Terms for Construction

  • Term: "active cavity" / "passive cavity" (’785 Patent, claim 1)

    • Context and Importance: This definitional pair is the core of the inventions claimed in the '785 and '692 patents. The entire infringement case for these patents rests on whether the accused devices possess structures that meet both definitions.
    • Intrinsic Evidence for a Broader Interpretation: The claims themselves provide the primary definition: an "active cavity" is one where "the refrigerant conduit extend[s] through," while a "passive cavity" is one where "the refrigerant conduit not extend[ing] through." (’785 Patent, col. 8:54-63). Plaintiff may argue this creates a simple, binary test based on the physical presence or absence of the conduit in a given cavity.
    • Intrinsic Evidence for a Narrower Interpretation: The specification describes the active cavities as the "heart of the ice forming site," where ice forms first and grows outward. (’785 Patent, col. 5:12-15). Defendants may argue that these terms imply a specific thermal and functional distinction, not just a structural one, and that a cavity is not truly "passive" if it still receives substantial cooling via conduction in a manner functionally equivalent to an "active" one.

  • Term: "serpentine tubing coil" (’538 Patent, claim 1)

    • Context and Importance: The geometry of the refrigerant path is a key limitation of claim 1 of the ’538 Patent. The construction of this term will determine whether the specific layout of refrigerant tubes in the Accused Products falls within the claim's scope.
    • Intrinsic Evidence for a Broader Interpretation: The specification describes the coil with general language as comprising "straight portions of tubing extending horizontally and connected serially at their ends by connecting portions." (’538 Patent, col. 4:48-55). This language could support an interpretation covering any generally back-and-forth path of tubes.
    • Intrinsic Evidence for a Narrower Interpretation: The patent figures, particularly Figure 1A, depict a highly regular and parallel arrangement of straight tubes joined by uniform, U-shaped bends. Defendants may argue that the term, in the context of the specification as a whole, is limited to this more orderly configuration and does not read on refrigerant paths with irregular spacing, angles, or connection methods.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced and contributory infringement for the '785 and '692 patents, and induced infringement for the '538 patent. (Compl. Counts II, IV, VI). The inducement allegations are based on Defendants allegedly providing user manuals and marketing materials that instruct and encourage customers to operate the Accused Products in an infringing manner. (Compl. ¶¶36, 52, 69). The contributory infringement allegations state that the Accused Products are material components of a larger infringing system, have no substantial non-infringing uses, and are sold with the knowledge that they will be combined with a water source to infringe system claims. (Compl. ¶¶53, 70).
  • Willful Infringement: Willfulness is alleged for all patents-in-suit. (Compl. ¶¶29-30, 45-46, 62-63). The allegations are based on two main sources of knowledge. First, alleged pre-suit knowledge by Defendant Bluenix is based on the prosecution history of its own patent application, during which the '538 and '785 patents were cited as relevant prior art. (Compl. ¶¶30, 46). Second, knowledge for both Defendants is alleged based on their receipt of a cease-and-desist letter on or about February 21, 2023. (Compl. ¶¶29, 45, 62).

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

  • A central issue will be one of claim construction and factual determination: Can the terms "active cavity" and "passive cavity," which form the crux of the '785 and '692 patents, be defined in a way that reads on the physical structure of the accused evaporators? The case may turn on whether the accused design exhibits the specific thermal and structural differentiation required by the claims, or if it operates on a principle that is technically distinct.
  • A key question for willfulness and potential damages enhancement will be the impact of Bluenix's prior patent prosecution: To what degree will the fact that Hoshizaki's patents were cited as prior art against Bluenix's own application be seen as establishing not just knowledge, but a deliberate disregard of a known risk of infringement?
  • The dispute will likely involve a significant evidentiary focus on the physical products: As the complaint is based on the inspection of actual hardware, the litigation will likely feature a direct, technical comparison of the internal evaporator assemblies, examining whether the precise geometric limitations of the claims—such as the "serpentine" path in the '538 patent and the "interspersed" cavities in the later patents—are met by the accused machines.