Beckman Coulter Inc v. Cytek Biosciences Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Beckman Coulter, Inc. (Delaware)
  • Defendant: Cytek Biosciences, Inc. (Delaware)
  • Plaintiff’s Counsel: Richards, Layton & Finger P.A.
• Case Identification: 1:24-cv-00945, D. Del., 08/14/2024
• Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant is incorporated in Delaware and conducts business in the state.
• Core Dispute: Plaintiff alleges that Defendant’s flow cytometers and cell sorters infringe patents related to optical subsystems and wavelength division multiplexers used in flow cytometry.
• Technical Context: Flow cytometry is a widely used biophysical technique for high-throughput analysis of cells and other microscopic particles, critical in fields such as immunology, molecular biology, and medical diagnostics.
• Key Procedural History: The complaint alleges that Defendant was aware of the asserted patents or their direct patent family members prior to the lawsuit, citing Defendant’s own patent prosecution files in which it submitted Information Disclosure Statements identifying the parent and grandparent patents of those asserted. The complaint also alleges that Plaintiff provided Defendant with actual notice of the asserted patents via a letter dated June 14, 2024.

Case Timeline

Date	Event
2012-05-30	Earliest Priority Date for ’582 and ’443 Patents
2019-05-07	Date by which Defendant allegedly knew of the ’174 Publication (grandparent of ’443 Patent, parent of ’582 Patent)
2019-06-25	’582 Patent Issued
2021-06-17	Date by which Defendant allegedly knew of the ’412 Patent (parent of ’582 Patent, grandparent of ’443 Patent)
2023-07-18	’443 Patent Issued
2024-06-14	Plaintiff sent notice letter to Defendant identifying the Asserted Patents
2024-08-14	Complaint Filed

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

U.S. Patent No. 10,330,582 - “Flow Cytometer” (Issued June 25, 2019)

The Invention Explained

• Problem Addressed: The patent addresses the need for improved optical subsystems in flow cytometers, seeking designs that are simple, reliable, compact, and easy to manufacture while separating light into multiple colored bands for analysis by low-noise detectors (’582 Patent, col. 2:1-7, col. 2:30-35).
• The Patented Solution: The invention describes an optical subsystem that uses a series of optical elements to manage a light path for analysis. A key aspect is the use of an "optical relay element," such as a concave mirror, to receive a collimated beam of light and produce an image. This relay architecture extends the collimated path length without significant beam expansion, which facilitates the separation of light into multiple colored bands using techniques like Wavelength Division Multiplexing (WDM) for detection by semiconductor detectors (’582 Patent, col. 4:35-56; Abstract).
• Technical Importance: This optical architecture aims to enable the use of smaller, more efficient semiconductor photodetectors in complex, multi-color flow cytometry systems, which are essential for advanced biological and medical research (’582 Patent, col. 4:52-60).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶27).
• The essential elements of independent claim 1 are:
  • An optical subsystem for a flow cytometer comprising:
  • a collimating optical element arranged to receive light from a light source and configured to project a collimated beam;
  • an optical relay element arranged to receive a portion of the collimated beam, where the relay element comprises a curved mirror configured to reflect the beam to produce a first image;
  • a first focusing optical element arranged to receive a portion of the collimated beam reflected by the relay element; and
  • a first semiconductor detector,
  • wherein the focusing optical element is configured to focus the beam onto the detector.
• The complaint incorporates by reference a claim chart exhibit that details the infringement allegations and notes the chart is not intended to limit Plaintiff's right to modify its contentions (Compl. ¶28).

U.S. Patent No. 11,703,443 - “Flow Cytometer” (Issued July 18, 2023)

The Invention Explained

• Problem Addressed: The patent, which shares a specification with the ’582 Patent, addresses the technical challenge of separating a light beam from a flow cytometer into multiple colored bands for analysis, particularly in a system that is reconfigurable and compatible with low-noise semiconductor detectors (’443 Patent, col. 2:30-36).
• The Patented Solution: The invention claims a specific architecture for a Wavelength Division Multiplexer (WDM). It uses a set of filters and at least one curved mirror arranged such that light passes from the filters to the mirror, which then reflects the light back to the filters for further separation before being sent to corresponding detectors (’443 Patent, Claim 1). This configuration, illustrated in the specification's Figure 25, creates an extended, folded optical path that allows for precise separation of different wavelengths of light (’443 Patent, col. 4:56-6:25).
• Technical Importance: This WDM design provides a compact and reconfigurable optical system for multi-color fluorescence detection, which is a core capability of modern high-parameter flow cytometers (’443 Patent, col. 2:30-36).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶35).
• The essential elements of independent claim 1 are:
  • A wavelength division multiplexer (WDM) for a flow cytometer comprising:
  • a set of filters configured to pass corresponding portions of light;
  • at least one mirror, including a curved mirror, configured to receive one or more portions of light from the set of filters and reflect the light to the set of filters; and
  • a set of detectors, each corresponding to a filter and configured to receive the light that passed through it.
• The complaint incorporates by reference an infringement chart (Exhibit 4) detailing how the accused products allegedly meet each element of the claim (Compl. ¶36).

III. The Accused Instrumentality

Product Identification

• The accused products are the Cytek Aurora flow cytometers, Cytek Aurora CS cell sorters, Cytek Northern Lights, and Cytek Northern Lights-CLC products (Compl. ¶¶12-13).

Functionality and Market Context

• The complaint alleges these products are flow cytometers and cell sorters that perform cell analysis using an optical system (Compl. ¶12). A central allegation is that these products employ "optical filter-based coarse wavelength division multiplexing (CWDM) demultiplexer arrays" to analyze light emitted from samples (Compl. ¶19). The complaint asserts these products are in direct competition with Plaintiff's own CytoFLEX flow cytometer and cell sorter products (Compl. ¶21).
• The complaint includes a visual comparison between an optical subsystem diagram from the asserted patents and a marketing diagram for the accused products. This comparison highlights the alleged use of "Proprietary high sensitivity Coarse Wavelength Division Multiplexing (CWDM) semiconductor detector arrays" in the accused products (Compl. ¶19).

IV. Analysis of Infringement Allegations

’582 Patent Infringement Allegations

Claim Chart Summary

• The complaint alleges infringement of at least claim 1 and references an infringement chart in Exhibit 3, which was not provided with the complaint. The claim language is quoted in the complaint body (Compl. ¶27).

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a collimating optical element arranged to receive light from a light source, the collimating optical element configured to project a collimated beam	The optical subsystem of the Accused Products allegedly contains an element that collimates light for analysis.	¶27-28	col. 4:40-45
an optical relay element arranged to receive at least a portion of the collimated beam..., the optical relay element comprising a curved mirror configured to reflect the portion of the collimated beam... to produce a first image	The Accused Products’ optical system, including its CWDM demultiplexer arrays, is alleged to function as a relay element that reflects the light beam to produce an image.	¶19, ¶27-28	col. 4:45-52
a first focusing optical element arranged to receive at least a portion of the collimated beam reflected by the optical relay element	The optical subsystem of the Accused Products allegedly contains a focusing element to direct the reflected light beam.	¶27-28	col. 4:52-56
a first semiconductor detector, wherein the first focusing optical element is configured to focus the portion of the collimated beam received from the optical relay element onto the first semiconductor detector	The Accused Products allegedly use semiconductor detectors, and their focusing elements are configured to direct the light beam onto these detectors for analysis.	¶19, ¶27-28	col. 4:52-56

Identified Points of Contention

• Scope Questions: A primary question will be whether the accused products' "optical filter-based coarse wavelength division multiplexing (CWDM) demultiplexer arrays" (Compl. ¶19) fall within the scope of the claim term "an optical relay element ... comprising a curved mirror." The dispute may center on whether a filter-based system can be considered structurally or functionally equivalent to the claimed "curved mirror" that "reflect[s]" the beam.
• Technical Questions: The complaint alleges that the accused optical systems are "substantially similar" based on high-level diagrams (Compl. ¶19). A factual question will be what the precise optical architecture of the accused products is, and whether that architecture actually "produce[s] a first image" as required by the claim, or if it merely separates and directs wavelengths of light without forming an image in the claimed optical sense.

’443 Patent Infringement Allegations

Claim Chart Summary

• The complaint alleges infringement of at least claim 1 and references an infringement chart in Exhibit 4, which was not provided with the complaint. The claim language is quoted in the complaint body (Compl. ¶35). The complaint includes a visual comparison between a patent diagram and a description of the accused products' CWDM arrays (Compl. ¶37).

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a set of filters, each filter of the set of filters configured to pass a corresponding portion of multiple portions of light	The accused products' CWDM system is alleged to contain a set of optical filters that separate light into different wavelength portions.	¶19, ¶35-36	col. 4:56-62
at least one mirror including at least one curved mirror, the at least one mirror configured to: receive one or more portions of the light from the set of filters; and reflect the one or more portions of the light to the set of filters	The accused products' CWDM system is alleged to contain a mirror component that receives light from its filters and reflects that light back to the filters for further processing, consistent with the claimed optical path.	¶19, ¶35-36	col. 5:1-10
a set of detectors, each detector of the set of detectors corresponding to a filter of the set of filters and configured to receive a portion of the light at the detector that passed through the filter...	The Accused Products allegedly use a set of semiconductor detectors corresponding to the filters in its CWDM system to receive and analyze the separated portions of light.	¶19, ¶35-36	col. 5:6-10

Identified Points of Contention

• Scope Questions: The infringement analysis will likely focus on the specific architecture required by the claim. A key question is whether the accused CWDM system has a "mirror" that performs the specific functions of receiving light from filters and reflecting it back to filters. The claim defines a specific relationship and light path, not just the mere presence of mirrors and filters in the same system.
• Technical Questions: The complaint's allegations are based on product literature describing a "filter-based" system (Compl. ¶19, ¶37). It raises the evidentiary question of whether the accused products contain a component that functions as the claimed "mirror" in the required reflective path, or if the light path is fundamentally different from the one claimed (e.g., a serial filtering path without reflection back to the filter set).

V. Key Claim Terms for Construction

U.S. Patent No. 10,330,582

• The Term: "optical relay element comprising a curved mirror"
• Context and Importance: This term is central to the infringement analysis for the ’582 Patent. The viability of the infringement claim depends on whether the accused products' "CWDM demultiplexer arrays" (Compl. ¶19) meet this limitation. Practitioners may focus on this term because its construction will determine whether a system described as "filter-based" can infringe a claim that explicitly requires a "curved mirror."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the function of the relay element as "effectively double[ing] the collimated path length" and extending it "without large beam expansion" (’582 Patent, col. 4:45-52). An argument could be made that any component performing this relay function, regardless of its specific composition, falls within the spirit of the invention.
  • Evidence for a Narrower Interpretation: Claim 1 explicitly recites that the relay element "compris[es] a curved mirror." The specification's embodiments consistently depict this element as a "concave mirror" (e.g., element 907 in FIG. 25; ’582 Patent, col. 5:1-10). This may support a narrower construction limited to components that are structurally identifiable as reflective mirrors.

U.S. Patent No. 11,703,443

• The Term: "at least one mirror ... configured to: receive one or more portions of the light from the set of filters; and reflect the one or more portions of the light to the set of filters"
• Context and Importance: This term defines a specific, required optical path rather than just a list of components. The infringement case for the ’443 Patent hinges on whether the accused CWDM system implements this exact sequence of operations. Practitioners may focus on this term because it creates a structural and functional constraint that may distinguish the claimed invention from other WDM architectures.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term "configured to" could be argued to encompass any system capable of performing the function, even if not its primary design.
  • Evidence for a Narrower Interpretation: The specification provides strong support for a specific architectural sequence. Figure 25 shows a light beam passing through a first dichroic filter (903), reflecting off a concave mirror (907), and then traveling toward a second dichroic filter (909), literally showing light going from a filter, to a mirror, and back to another filter in the set (’443 Patent, FIG. 25). This embodiment directly illustrates the claimed light path and may support a construction requiring this specific sequence.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement under § 271(b), asserting that Defendant provides customers with user guides and instructions that encourage and instruct them to operate the accused products in an infringing manner (Compl. ¶¶29, 37). It further alleges contributory infringement under § 271(c), stating that the accused products are material components specifically designed for use in the patented methods and are not staple articles of commerce with substantial non-infringing uses (Compl. ¶¶30, 38).
• Willful Infringement: The complaint alleges willful and deliberate infringement based on both pre-suit and post-suit knowledge. Pre-suit knowledge is alleged based on Defendant’s status as a direct competitor, its alleged monitoring of Plaintiff's patent portfolio, constructive notice from Plaintiff's virtual patent marking, and Defendant's citation to the asserted patents' parent and grandparent in its own patent prosecution filings (Compl. ¶¶17-21). Post-suit knowledge is based on a letter Plaintiff sent to Defendant on June 14, 2024, which allegedly provided actual notice of the infringement (Compl. ¶¶22, 31, 39).

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

• A core issue will be one of definitional scope: Can the claims of the asserted patents, which recite specific optical architectures involving a "curved mirror" (’582 Patent) and a distinct filter-mirror-filter light path (’443 Patent), be construed to cover the accused products’ technology, described in the complaint as "optical filter-based coarse wavelength division multiplexing (CWDM) demultiplexer arrays"?
• A second central issue will be one of technical evidence: The infringement allegations rely heavily on high-level marketing materials and diagrams. A key evidentiary question is whether the actual, detailed optical design of the accused Cytek products contains the specific structures and performs the precise functions required by the asserted claims, or if there is a fundamental mismatch in their technical operation.
• Finally, the willfulness claim raises a question of pre-suit knowledge and intent: Given the specific allegation that Defendant cited the patents' direct ancestors during its own patent prosecution, a key question for the court will be whether this act establishes pre-suit knowledge of the patented technology and whether Defendant’s subsequent actions constituted objective recklessness regarding Plaintiff's patent rights.