DCT

1:24-cv-00579

Seoul Semiconductor Co Ltd v. Technical Consumer Products Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00579, D. Del., 07/12/2024
  • Venue Allegations: Venue is alleged to be proper as Defendant is a Delaware corporation and therefore a resident of the district.
  • Core Dispute: Plaintiff alleges that Defendant’s LED lighting products, including those supplied to third parties under the "Great Value" brand, infringe ten patents related to various aspects of LED device structure, packaging, materials, and control systems.
  • Technical Context: The technology at issue involves light-emitting diodes (LEDs), the dominant semiconductor technology for modern lighting, valued for its efficiency, longevity, and small size.
  • Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of infringement beginning at least in July 2023 via correspondence with Defendant's customer, Walmart, which was forwarded to Defendant. Direct correspondence with Defendant's counsel allegedly began in February 2024. Additionally, U.S. Patent No. 10,134,967 underwent an inter partes review (IPR), resulting in the cancellation of its original claims and the substitution of amended claims, which are now asserted in this litigation.

Case Timeline

Date Event
2007-10-29 Earliest Priority Date ('207 Patent)
2008-11-18 Earliest Priority Date ('967, '821, '050 Patents)
2010-11-26 Earliest Priority Date ('496 Patent)
2011-07-19 '207 Patent Issued
2013-12-10 '496 Patent Issued
2014-02-25 '050 Patent Issued
2014-08-18 Earliest Priority Date ('933 Patent)
2014-08-19 Earliest Priority Date ('800 Patent)
2015-06-24 Earliest Priority Date ('675 Patent)
2015-09-29 '821 Patent Issued
2017-10-24 '800 Patent Issued
2017-11-30 Earliest Priority Date ('836 Patent)
2018-03-27 '314 Patent Issued
2018-11-20 '967 Patent Issued
2019-12-17 '933 Patent Issued
2022-04-05 '967 Patent Inter Partes Review Certificate Issued
2023-04-18 '836 Patent Issued
2023-08-08 '675 Patent Issued
2023-07-11 Plaintiff sends first notice letter to Walmart, identifying TCP products
2024-01-26 Walmart allegedly forwards infringement claims to suppliers, including TCP
2024-02-20 Plaintiff's counsel sends first notice letter to TCP's counsel
2024-07-12 Complaint Filed

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

U.S. Patent No. 11,721,675 - "White Light Source System"

The Invention Explained

  • Problem Addressed: The patent addresses the need for artificial light sources that can accurately reproduce sunlight, which is beneficial for applications like museum lighting and for human health and well-being in indoor environments (U.S. Patent No. 11,721,675, col. 1:25-33). Conventional LED lighting often fails to replicate the full, continuous spectrum of natural sunlight, leading to unnatural color rendering (U.S. Patent No. 11,721,675, col. 2:10-14).
  • The Patented Solution: The invention provides a light emitting device that uses at least two different light emitters, each with a distinct color temperature and specific phosphor composition, to create a combined white light output. The properties of the phosphors, such as their half-value widths and particle sizes in a first emitter, and the peak wavelength distances in a second emitter, are specifically defined to achieve a desired spectral quality (U.S. Patent No. 11,721,675, Abstract; col. 5:23-41). A controller manages the output to produce the intended white light (U.S. Patent No. 11,721,675, Fig. 27).
  • Technical Importance: This approach of combining multiple, specifically-tuned emitters allows for more precise control over the spectral power distribution of the output light, enabling a closer replication of natural sunlight compared to simpler blue-LED-plus-yellow-phosphor systems (U.S. Patent No. 11,721,675, col. 2:27-34).

Key Claims at a Glance

  • The complaint asserts independent claim 18.
  • Essential elements of claim 18 include:
    • A substrate.
    • A light emitting source disposed on the substrate.
    • A cover disposed on the light emitting source.
    • A controller configured to electrically control the light emitting source.
    • The light emitting source comprising a first light emitter (with a first color temperature) and a second light emitter (with a second color temperature).
    • The first light emitter having a first converter with specific properties (plurality of phosphors with different half-value widths; particle size range of 5 µm to 50 µm).
    • The second light emitter having a second converter with specific properties (plurality of phosphors with different peak wavelengths; distance between peak wavelengths of at least two phosphors is 150 nm or less; thickness range of 100 µm to 1000 µm).
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,632,836 - "Light-Emitting Apparatus Including Light-Emitting Diode"

The Invention Explained

  • Problem Addressed: The patent addresses the desire for indoor lighting that can mimic the spectral changes of natural sunlight throughout the day, which is believed to promote user health and align with human biorhythms (U.S. Patent No. 11,632,836, col. 1:21-44). Conventional indoor lighting typically provides a static white light that does not replicate these natural variations.
  • The Patented Solution: The invention is a light-emitting apparatus with multiple emitters that can be independently controlled to adjust the characteristics of the output light. It includes a first emitter for visible light, composed of multiple sources with different color temperatures, and a second emitter for light with a longer peak wavelength (e.g., infrared). A controller, connected to a user interface, allows a user to not only adjust the visible light characteristics but also to disable the second emitter upon receiving a specific input (U.S. Patent No. 11,632,836, Abstract; col. 2:3-9).
  • Technical Importance: This design provides user-configurable control over a multi-spectrum lighting system, allowing for dynamic adjustment of visible light and the selective inclusion or exclusion of other wavelengths, offering greater flexibility than fixed-spectrum lighting (U.S. Patent No. 11,632,836, col. 1:57-64).

Key Claims at a Glance

  • The complaint asserts independent claim 1.
  • Essential elements of claim 1 include:
    • A first light emitter comprising a plurality of light sources, each configured to emit light with a different color temperature.
    • Each light source comprising a light-emitting diode chip and a wavelength conversion member.
    • A second light emitter comprising at least one light emitting structure configured to emit light with a longer peak wavelength than the first light emitter.
    • A controller configured to adjust characteristics of light from the first and second light emitters.
    • A user interface member connected to the controller to receive user input.
    • The controller is further configured to disable the second light emitter in response to an input for prohibiting emission from the light emitting structure.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 10,510,933 - "Light Emitting Diode Package and Manufacturing Method Thereof"

  • Technology Synopsis: This patent relates to an LED package designed to produce white light with high color rendering. The technology involves a blue light-emitting chip combined with specific green and red phosphors within an encapsulant, as well as a housing with a particular cross-sectional shape having upper, intermediate, and lower portions to manage light output ('933 Patent, col. 6:3-10; Compl. ¶¶51, 53).
  • Asserted Claims: Exemplary independent claim 15 is asserted (Compl. ¶49).
  • Accused Features: The Great Value #GVP38DLMOTION product is accused of infringing based on its use of a blue LED chip with green and red phosphors and a housing that allegedly has the claimed cross-sectional shape (Compl. ¶¶50-53).

U.S. Patent No. 8,659,050 - "Slim LED package"

  • Technology Synopsis: This patent describes a "slim" LED package structure focused on the physical arrangement of the lead frames. The invention specifies lead frames that include a groove comprising a plurality of sub-grooves with a triangular cross-section, where a resin is formed in the groove to secure the components ('050 Patent, Abstract; col. 8:7-12). This design aims to create a thin yet robust package.
  • Asserted Claims: Exemplary independent claim 1 is asserted (Compl. ¶59).
  • Accused Features: The Great Value #GVP38DLMOTION product is accused of infringing based on its lead frame construction, which allegedly includes grooves and sub-grooves filled with resin as claimed (Compl. ¶¶62-63).

U.S. Patent No. 10,134,967 - "Light Emitting Device"

  • Technology Synopsis: This patent, asserting claims amended by an inter partes review certificate, describes an LED device with a specific lead frame structure designed to improve adhesion with a molding unit. The claims require first, second, and third "undercut sidewalls" that define a "fixing space," as well as a "fixing hole" located in the interior portions of the lead frames that includes an undercut sidewall ('967 Patent, claim 17).
  • Asserted Claims: Exemplary independent claim 17 (as amended) is asserted (Compl. ¶68).
  • Accused Features: The Great Value #GVP38DLMOTION product is accused based on its lead frame geometry, which allegedly includes the claimed arrangement of multiple undercut sidewalls and fixing holes with undercuts, as shown in cross-sectional and x-ray images (Compl. ¶¶70-75).

U.S. Patent No. 9,147,821 - "Light Emitting Device"

  • Technology Synopsis: This patent concerns the physical structure of lead frames in an LED package. The invention describes lead frames having upper and lower portions with different planar shapes, where the upper portions extend further into the space between the frames than the lower portions ('821 Patent, col. 5:35-42). This creates an "inset sidewall" that partially defines an "outer fixing space."
  • Asserted Claims: Exemplary independent claim 1 is asserted (Compl. ¶80).
  • Accused Features: The Great Value #GVP38DLMOTION product is accused based on its lead frame structure. Cross-sectional and x-ray images allegedly show upper and lower portions with different planar shapes, creating the claimed inset sidewall and outer fixing space (Compl. ¶¶83-85).

U.S. Patent No. 7,982,207 - "Light Emitting Diode"

  • Technology Synopsis: This patent describes the structure of an LED chip itself, focusing on the electrical contacts. The invention includes a transparent electrode layer with an opening, an electrode pad arranged on the transparent electrode, and a "current blocking portion" comprising the region of contact between the p-type semiconductor layer and an aluminum layer within the opening ('207 Patent, Abstract; col. 6:8-16).
  • Asserted Claims: Exemplary independent claim 7 is asserted (Compl. ¶90).
  • Accused Features: The Great Value #GVVCQA6027ND product is accused based on the structure of its LED chip. SEM images allegedly show the claimed arrangement of semiconductor layers, a transparent electrode, an opening, and an electrode pad with a current blocking portion (Compl. ¶¶93-95).

U.S. Patent No. 9,929,314 - "Light Emitting Diode Chip Having Electrode Pad"

  • Technology Synopsis: This patent relates to the layout of electrode pads and extensions on an LED chip to improve current spreading. The invention claims a first electrode pad with a first extension having alternating portions that are in contact and not in contact with an underlying semiconductor layer, along with a second electrode pad and extension ('314 Patent, claim 1).
  • Asserted Claims: Exemplary independent claim 1 is asserted (Compl. ¶100).
  • Accused Features: The Great Value #GVVCQA6027ND product is accused based on its LED chip's electrode layout. Microscope images allegedly show first and second electrode pads and extensions, with the first extension having the claimed alternating contact and non-contact portions (Compl. ¶¶105-107).

U.S. Patent No. 8,604,496 - "Optical Semiconductor Device"

  • Technology Synopsis: This patent describes the layered structure within the light-emitting element of an LED. The invention claims a "functional part" that includes a plurality of active layers, where at least two active layers comprise a "multilayer stacked body" (alternating thick and thin film layers), an n-side barrier layer, a well layer, and a p-side barrier layer arranged in a specific sequence ('496 Patent, claim 1).
  • Asserted Claims: Exemplary independent claim 1 is asserted (Compl. ¶112).
  • Accused Features: The Great Value #GVVCQA6027ND product is accused based on the epitaxial structure of its LED chips. TEM images allegedly reveal the claimed sequence of multilayer stacked bodies, barriers, and well layers (Compl. ¶114).

U.S. Patent No. 9,799,800 - "Light Emitting Device and Method of Fabricating the Same"

  • Technology Synopsis: This patent relates to the specific composition of the p-type semiconductor layer in an LED to improve hole injection. The invention claims a hole transport layer that includes a first sublayer with relatively low dopant concentration, an intermediate sublayer with relatively high dopant concentration, and a second sublayer with relatively low dopant concentration ('800 Patent, claim 1).
  • Asserted Claims: Exemplary independent claim 1 is asserted (Compl. ¶119).
  • Accused Features: The Great Value #GVVCQA6027ND product is accused based on the layered structure of its p-type semiconductor layer. A TEM image allegedly shows a hole transport layer with the claimed sublayers of varying dopant concentrations (Compl. ¶¶122-123).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies three categories of accused products: (1) the TCP #L120DR56DCCT2; (2) the Great Value #GVP38DLMOTION; and (3) the Great Value #GVVCQA6027ND (Compl. ¶30). The complaint alleges that Defendant TCP is a supplier of the accused Great Value branded products to Walmart (Compl. ¶27).

Functionality and Market Context

  • The TCP #L120DR56DCCT2 is described as an LED package with multiple light emitters of different color temperatures, a cover, and a controller with a user interface for adjusting light characteristics (Compl. ¶¶33, 44). An annotated image shows the disassembled product, revealing a circuit board with multiple LED components, a controller chip, and a removable cover (Compl. p. 10).
  • The Great Value #GVP38DLMOTION and #GVVCQA6027ND products are described as LED light bulbs containing a plurality of LED packages or chips (Compl. ¶¶50, 91). The complaint provides detailed analysis of these internal components, including optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), and x-ray images of the LED packages and chips after removal from the bulb housing and decapsulation (Compl. ¶¶50, 51, 60, 72, 81, 91, 113, 120). These images are used to allege that the micro-scale physical structures and material layers of the LEDs meet specific patent claim limitations. The complaint alleges these products are sold in high volume through retailers like Walmart (Compl. ¶21).

IV. Analysis of Infringement Allegations

'675 Patent Infringement Allegations

Claim Element (from Independent Claim 18) Alleged Infringing Functionality Complaint Citation Patent Citation
a substrate The accused TCP #L120DR56DCCT2 includes a substrate shown as the base of the LED package. ¶33 col. 28:65-66
a light emitting source disposed on the substrate, the light emitting source comprising a first light emitter...and a second light emitter The device's light emitting source is disposed on the substrate and includes distinct first and second light emitters. An annotated photograph identifies the separate groups of LEDs corresponding to the first and second light emitters (Compl. p. 10). ¶33 col. 29:1-4
the first light emitter has a first converter comprising a first plurality of phosphors and a first resin, each phosphor of the first plurality of phosphors having different half-value widths...at least one of the plurality of phosphors of the first converter has a particle size in a range of 5 um to 50 um A scanning electron microscope cross-section of the first light emitter allegedly shows a first converter composed of phosphors and a resin. The complaint alleges these phosphors have the claimed properties. ¶34 col. 29:5-13
the second light emitter has a second converter comprising a second plurality of phosphors and a second resin, each phosphor of the second plurality of phosphors having different peak wavelengths, wherein a distance between peak wavelengths of at least two phosphors of the second converter is 150 nm or less, and wherein a thickness of the second converter is in a range of 100 um to 1000 um A scanning electron microscope cross-section of the second light emitter allegedly shows a second converter with phosphors and a resin. The image is annotated to show a measured thickness of 403.3 µm, which is within the claimed range (Compl. p. 11). ¶35 col. 29:14-23
a controller configured to electrically control the light emitting source The device includes a controller, shown in an image of the device's electronics, which is alleged to electrically control the light emitting source. ¶33 col. 29:26-28
  • Identified Points of Contention:
    • Technical Questions: The complaint alleges that the phosphors in the accused device meet specific, quantitative limitations regarding "half-value widths," "particle size," and "distance between peak wavelengths." A central evidentiary question will be whether testing of the accused device confirms these specific numerical properties as required by the claim.
    • Scope Questions: The analysis may raise questions regarding how terms like "color temperature" and "converter" are defined within the patent's specification and whether the accused product's components fall within those definitions.

'836 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a first light emitter comprising a plurality of light sources, each of the light sources being configured to emit light with a different color temperature The accused product includes a first light emitter with multiple light sources, which are alleged to emit light of different color temperatures. ¶41 col. 16:9-12
each of the light sources comprises a light-emitting diode chip and a wavelength conversion member configured to convert a wavelength range of light emitted from the light-emitting diode chip Images allegedly show that each light source includes an LED chip (revealed after removing molding) and a wavelength conversion member (shown in a cross-sectional view). ¶42 col. 16:13-17
a second light emitter comprising at least one light emitting structure configured to emit light having a longer peak wavelength than that emitted from the first light emitter The product includes a second light emitter with at least one light emitting structure, which is alleged to emit light at a longer peak wavelength than the first emitter. An annotated image identifies the second light emitter on the device's circuit board (Compl. p. 13). ¶43 col. 16:18-22
a controller configured to adjust characteristics of light emitted from the first and second light emitters The device includes a controller, identified in an image of the circuit board, which is alleged to adjust the light characteristics. ¶44 col. 16:23-25
a user interface member configured to receive input of a user and connected to the controller The device includes a user interface member, shown connected to the controller, for receiving user input. ¶44 col. 16:26-27
the controller is further configured to disable the second light emitter in response to receiving an input for prohibiting emission of the light emitting structure through the user interface member The complaint alleges the controller is configured to perform this specific disabling function in response to a user input. ¶44 col. 16:28-32
  • Identified Points of Contention:
    • Functional Questions: A primary point of contention will likely be the final "disabling" limitation. The infringement analysis will depend on whether the accused device's controller is, in fact, configured to perform this exact logical operation. What evidence does the complaint provide that the controller's software or hardware implements the function of "disabl[ing] the second light emitter" specifically in response to an input "for prohibiting emission"?
    • Scope Questions: The construction of the term "disable" could be a key issue. Does "disable" require a complete cessation of power, or could it be construed to cover a significant reduction in power or a change in operational mode?

V. Key Claim Terms for Construction

  • For the '675 Patent:

    • The Term: "converter"
    • Context and Importance: This term is central because claim 18 defines the "first converter" and "second converter" by a list of specific, quantitative physical and material properties (e.g., phosphor types, particle sizes, layer thickness). The infringement case for this patent depends entirely on whether the accused device's components meet these detailed requirements.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes the converter more generally as a component that "includes phosphors and a resin" ('675 Patent, col. 5:27-28), which could suggest that the core definition is simply a phosphor/resin mixture.
      • Evidence for a Narrower Interpretation: The detailed description repeatedly links the converter to specific embodiments with particular phosphor materials and characteristics, such as "a phosphor having a half-value width of 33 nm to 110 nm" ('675 Patent, col. 5:32-34) and a thickness of "0.07 mm to 1.5 mm" ('675 Patent, col. 5:40-41). This may support an interpretation where the term "converter" incorporates these more specific properties from the specification.

  • For the '836 Patent:

    • The Term: "disable the second light emitter"
    • Context and Importance: Practitioners may focus on this term because the infringement allegation hinges on a specific function performed by the accused controller. The outcome will depend on whether the accused product's operation, in response to user input, performs an action that falls within the court's construction of "disable."
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent does not appear to provide an explicit definition of "disable." A party could argue for its plain and ordinary meaning, which might encompass various forms of rendering the emitter non-operational, such as turning it off, putting it in a standby mode, or significantly reducing its output.
      • Evidence for a Narrower Interpretation: The context of the claim is a user "prohibiting emission." This language may support a narrower construction requiring a complete cessation of light output from the second emitter, as opposed to merely dimming it or changing its characteristics. The specification states the controller is configured to disable the emitter "when an input for prohibiting emission of the infrared rays is received" ('836 Patent, col. 2:6-8), linking the action directly to the concept of prohibition.

VI. Other Allegations

  • Indirect Infringement: The complaint focuses on direct infringement under 35 U.S.C. § 271(a) for all asserted counts and does not plead separate counts for indirect infringement.
  • Willful Infringement: The complaint alleges willful infringement for all ten asserted patents (Compl. ¶¶ 37, 46, 56, 65, 77, 87, 97, 109, 116, 125). The basis for willfulness is alleged pre-suit knowledge. The complaint details a series of notice letters sent first to Defendant's customer, Walmart, starting on July 11, 2023, which allegedly identified specific infringing products and patents (Compl. ¶21). It is further alleged that Walmart forwarded these claims to its suppliers, including TCP, and that TCP was aware of the infringement concerns since at least July 2023 (Compl. ¶¶24-25). The complaint also alleges direct notice to TCP's own counsel beginning February 20, 2024, which included claim charts (Compl. ¶¶25, 28).

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

  • A core issue will be one of evidentiary proof: for the numerous patents relating to specific physical structures (e.g., the '967 patent's "undercut sidewalls," the '050 patent's "triangular sub-grooves," and the '675 patent's phosphor "particle size"), the case will turn on a factual battle of technical experts and microscopic evidence. The central question is whether the structures and materials of the accused products, as they are actually manufactured, fall within the precise, often quantitative, limitations of the claims.
  • A key legal and functional question will be one of operational equivalence: for patents covering system control, such as the '836 patent, the dispute will likely focus on whether the accused controller's software and hardware perform the specific logical functions recited in the claims. Can Plaintiff demonstrate that the accused device's response to a user input constitutes "disabl[ing] the second light emitter" in the manner required by the claim language and specification?
  • A central issue for damages will be willfulness: given the extensive pre-suit notice alleged in the complaint, including the provision of claim charts to Defendant's counsel months before the suit was filed, a critical question for the court will be whether Defendant's continued activities after receiving such notice were objectively reckless, potentially leading to enhanced damages.