DCT

1:15-cv-01220

Delaware Display Group LLC v. Lenovo Group Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:15-cv-01220, D. Del., 12/30/2015
  • Venue Allegations: Venue is based on Defendant’s Delaware corporate status, regular business conduct, sales, customer support, and operation of an interactive website within the district.
  • Core Dispute: Plaintiffs allege that Defendant’s laptops, desktops, and tablets incorporating edge-lit Liquid Crystal Displays (LCDs) infringe three patents related to backlight panel assemblies.
  • Technical Context: Edge-lit backlight technology is fundamental to producing thin, power-efficient, and uniformly illuminated screens for consumer electronics, a highly competitive and valuable market.
  • Key Procedural History: This complaint is a re-filing of claims from a prior lawsuit (13-cv-2108) that was stayed pending inter partes review (IPR) proceedings initiated by Lenovo against the patents-in-suit. Plaintiffs dismissed the patents from the first suit without prejudice before filing this action. The complaint notes Plaintiffs’ intent to await final decisions from the Patent Trial and Appeal Board (PTAB) in IPRs including IPR2014-01362, IPR2015-00487, and IPR2015-00506. Post-filing IPR certificates, included with the patent documents, indicate that all asserted independent claims of the '177 and '973 patents have since been cancelled, a development that fundamentally impacts the scope of this litigation.

Case Timeline

Date Event
1995-06-27 Earliest Priority Date for '660, '177, and '973 Patents
2008-06-10 U.S. Patent No. 7,384,177 Issued
2008-07-29 U.S. Patent No. 7,404,660 Issued
2008-10-14 U.S. Patent No. 7,434,973 Issued
2012-02-16 Alleged date of Lenovo's first notice of patents via meeting with Rambus, Inc.
2013-12-31 Plaintiffs file "First Lawsuit" against Lenovo
2015-10-21 Patents-in-suit dismissed without prejudice from First Lawsuit
2015-12-30 Complaint Filing Date

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

U.S. Patent No. 7,404,660 - “Light Emitting Panel Assemblies,” issued July 29, 2008

The Invention Explained

  • Problem Addressed: The patent seeks to improve upon known light-emitting panel assemblies to achieve better control over light distribution and more efficient use of light, leading to greater output from the panel (ʼ660 Patent, col. 1:19-28).
  • The Patented Solution: The invention uses a generally flat "optical conductor" that receives light from an edge-mounted source, such as an LED. The conductor is described as having two distinct areas: a "transition region" to receive and spread the light from the source, and an "output region" containing a pattern of "deformities" that cause the light to be emitted from the panel's surface ('660 Patent, Abstract). The configuration of the transition region, which can be shaped or feature reflective surfaces, is designed to efficiently channel light into the main body of the panel ('660 Patent, col. 3:15-26).
  • Technical Importance: This design's focus on separating the light-injection and light-emission functions aims to create thinner, brighter, and more power-efficient displays, which are critical features for portable electronics (Compl. ¶26).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" without specifying which ones (Compl. ¶33). Independent claim 1 is representative of the core technology.
  • Independent Claim 1 recites:
    • A generally planar optical conductor with an input edge wider than it is thick.
    • A plurality of light sources positioned at the input edge, each generating a light output that is wider than it is high.
    • An output region on the conductor with a predetermined pattern of deformities to emit light.
    • A transition region on the conductor located between the light source and the output region.
  • The complaint implicitly reserves the right to assert other claims, including dependent claims.

U.S. Patent No. 7,384,177 - “Light Emitting Panel Assemblies,” issued June 10, 2008

The Invention Explained

  • Problem Addressed: The patent addresses the general need for efficient and uniform light-emitting panel assemblies, similar to the '660 patent ('177 Patent, col. 1:19-28).
  • The Patented Solution: This invention centers on a structural "tray" with a back wall and "continuous side walls" that form a cavity to house the light source(s) and other components ('177 Patent, Abstract). The tray itself acts as a reflector and includes "secondary flat, angled, faceted or curved" reflective surfaces. These secondary surfaces are designed to redirect light within the cavity to improve light mixing and achieve a more uniform output, particularly for producing white light from multiple colored LEDs ('177 Patent, col. 6:1-11; Claim 17).
  • Technical Importance: This integrated tray-and-reflector design provides a structural and optical solution for building compact, efficient backlight units with uniform illumination (Compl. ¶26).

Key Claims at a Glance

  • The complaint asserts "one or more claims" without specification (Compl. ¶45). Independent claim 1 is representative.
  • Independent Claim 1 recites:
    • A tray with a back wall and continuous side walls forming a hollow cavity completely surrounded by the side walls.
    • At least one light source positioned in the cavity.
    • At least one sheet, film, or substrate overlying the assembly to control the emitted light.
    • The tray acts as a reflector and has one or more secondary reflective or refractive surfaces to redirect light within the cavity.
  • A post-filing IPR certificate indicates that independent claim 1, along with claims 2-3, 5-7, 9, 10, 13-15, 19, 21, and 23-27, have been cancelled ('177 Patent IPR Certificate, p. 2). This significantly narrows the potential scope of infringement for this patent.

U.S. Patent No. 7,434,973 - “Light Emitting Panel Assemblies,” issued October 14, 2008

Technology Synopsis

This patent details a light-emitting panel where light output is controlled by a pattern of "individual light extracting deformities" (e.g., microscopic projections or depressions) on the panel surface ('973 Patent, Abstract). The key inventive concept is that these deformities have well-defined shapes with angled surfaces, and their properties—such as density, size, or orientation—are varied across the panel relative to the light source(s) to achieve a precisely controlled and uniform light output ('973 Patent, col. 2:1-10; Compl. ¶25).

Asserted Claims

The complaint asserts "one or more claims" (Compl. ¶57). A post-filing IPR certificate indicates that independent claims 1 and 6, along with dependent claims 2-5, have been cancelled ('973 Patent IPR Certificate, p. 2).

Accused Features

The complaint alleges that Lenovo's backlights use a panel member with a pattern of deformities that increase in density or size with distance from the edge-lit light sources to produce a desired light output for illuminating an LCD (Compl. ¶25, ¶57).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Lenovo-branded "laptops, desktops, and tablets with edge-lit backlights for illuminating liquid crystal displays," with the IdeaPad Y510 and the N580 notebooks cited as specific examples (Compl. ¶22).

Functionality and Market Context

  • The complaint alleges the accused products contain edge-lit backlights that incorporate the patented technologies. These technologies are alleged to include optical conductors with distinct transition and output regions, patterns of deformities for light extraction, and reflective trays with secondary surfaces for light mixing (Compl. ¶23-25).
  • The complaint alleges that incorporating these inventions allows Lenovo to create "improved products," including those with thinner displays, more uniform light output, lower power requirements, and longer battery life (Compl. ¶26).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'660 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a generally planar optical conductor having at least one input edge with a greater cross-sectional width than thickness The accused backlights include "optical conductors that receive light from light sources." ¶23; ¶33 col. 3:1-4
a plurality of light sources...positioned adjacent to the input edge The light sources are described as LEDs arranged "adjacent to an input edge of the optical conductor such that they can direct light into the optical conductor." ¶23; ¶33 col. 3:1-3
the optical conductor having at least one output region and a predetermined pattern of deformities configured to cause light to be emitted from the output region The "output region on the optical conductor includes a predetermined pattern of deformities for emitting light." ¶23; ¶33 col. 4:38-44
the optical conductor having a transition region disposed between the light source and the output region "The optical conductor also has a transition region between the light sources and the output region." ¶23; ¶33 col. 3:1-14

'177 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a tray having a back wall and continuous side walls that form a hollow cavity or recess completely surrounded by the side walls The accused backlights "include a tray having a back wall and continuous side walls that form a hollow cavity or recess completely surrounded by the side walls." ¶24; ¶45 col. 5:66-67
at least one light source located, mounted or positioned in the cavity or recess The accused backlights "include several light sources (e.g., LEDs in a strip) in the tray's cavity or recess." ¶24; ¶45 col. 5:66-col. 6:1
at least one sheet, film or substrate overlying the assembly for controlling the light emitted from the assembly The accused backlights "include at least one sheet, film or substrate (e.g., a diffuser and/or brightness enhancement film) for controlling the light emitted from the assembly." ¶24; ¶45 col. 6:3-7
the tray...has one or more secondary flat, angled, faceted or curved reflective or refractive surfaces to redirect...light The tray "includes secondary flat, angled, faceted or curved reflective surfaces that redirect the light in a predetermined manner...to increase the efficiency of the backlight, and also that facilitate better mixing of the light." ¶24; ¶45 col. 6:1-11

Identified Points of Contention

  • Validity: The primary point of contention for the '177 and '973 patents is the existence of any valid and infringed claims, given the cancellation of all independent claims and numerous dependent claims in post-filing IPR proceedings.
  • Scope Questions: For the '660 patent, a key dispute may concern the definition of "transition region." The analysis will question whether the accused products contain a structurally distinct region corresponding to the patent's teachings, or a continuous, undifferentiated light guide. For the '177 patent, should any claims survive, a dispute may arise over whether a standard product housing meets the "tray...completely surrounded by the side walls" limitation.
  • Technical Questions: A factual question for the '660 and '973 patents is whether the accused products' light-extracting features constitute the claimed "deformities" and if their distribution and function match the patent descriptions.

V. Key Claim Terms for Construction

For the ’660 Patent

  • The Term: "transition region"
  • Context and Importance: This term is central to the architecture of Claim 1. The infringement analysis depends on whether the accused products possess a component or area that meets this definition, distinct from the "output region." Practitioners may focus on this term because its construction will determine if a simple, continuous light guide can infringe.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a functional definition, describing it as an "area...used to make the transition from the light source 3 to the light emitting panel 2" ('660 Patent, col. 3:1-4). This language could support an interpretation covering any portion of a light guide between the LED and the primary viewing area.
    • Evidence for a Narrower Interpretation: Embodiments in the patent figures depict the transition region as a physically distinct and specially shaped structure, such as an integral extension (Fig. 1, element 4) or an off-axis, thicker section designed to redirect light (Fig. 10, element 63), which could support a narrower construction limited to such non-uniform structures.

For the ’177 Patent

  • The Term: "tray having a back wall and continuous side walls that form a hollow cavity or recess completely surrounded by the side walls"
  • Context and Importance: This limitation defines the core structure of the assembly in Claim 1. Its construction is critical because it dictates whether a conventional backlight housing, which may have gaps, seams, or be integrated into a larger chassis, falls within the claim's scope.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue the term should be read functionally to mean any structure that generally encloses the backlight components to guide light.
    • Evidence for a Narrower Interpretation: The terms "continuous" and "completely surrounded" suggest an unbroken, seamless, and fully enclosing structure. The depiction in Figure 6 (element 35) shows a single, encompassing piece, which may support a narrower construction that excludes multi-part or open-sided housings.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges Lenovo induces infringement by third parties (e.g., distributors, consumers) by "creating advertisements that promote the infringing use," establishing distribution channels, and providing instructions or manuals (Compl. ¶39; ¶51; ¶63).
  • Willful Infringement: The willfulness claim is based on alleged knowledge of the patents dating back to at least February 16, 2012, from meetings between Lenovo and the patents' prior owner, Rambus, Inc. The complaint alleges that Lenovo continued to infringe despite this pre-suit notice and after the filing of the first lawsuit (Compl. ¶36-38; ¶48-50; ¶60-62).

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

  • A threshold issue for the '177 and '973 patents is one of viability: given that post-filing IPR proceedings resulted in the cancellation of all asserted independent claims, the court's first inquiry will be whether any valid and enforceable claims remain for adjudication.
  • A central issue for the surviving '660 patent will be one of claim construction: can the term "transition region," which is depicted in embodiments as a distinct structural feature, be construed to read on the potentially uniform light guides found in mass-market consumer electronics?
  • A key evidentiary question for the willfulness allegations will be the sufficiency of notice: what specific information was conveyed during the 2012 meetings with Rambus, and does that evidence establish that Lenovo had knowledge of infringement of the specific asserted patents, as opposed to general knowledge of a technology portfolio?