DCT

1:26-cv-00105

Buffalo Games LLC v. Guangzhou Yuehong Technology Co Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-00105, W.D.N.Y., 01/16/2026
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant conducts significant business in the State of New York and within the Western District of New York.
  • Core Dispute: Plaintiff alleges that Defendant’s "LCD Writing Tablet for Kids" infringes a patent related to multicolored, pressure-sensitive liquid crystal display technology.
  • Technical Context: The technology at issue involves low-power, reusable electronic writing surfaces that display multiple colors in response to pressure from a stylus, aiming to replicate the experience of drawing on paper with colored pens.
  • Key Procedural History: The complaint alleges that Plaintiff initiated an Amazon Patent Evaluation Express (APEX) proceeding against Defendant in September 2025. Subsequently, in October 2025, Defendant filed a declaratory judgment action in the Southern District of New York, seeking a declaration of non-infringement and invalidity of the patent-in-suit. Plaintiff notes it filed a motion to dismiss or transfer that action, which was pending as of the filing of this complaint.

Case Timeline

Date Event
2015-12-16 ’672 Patent Priority Date
2018-03-27 ’672 Patent Issue Date
2025-09-24 Plaintiff initiates Amazon APEX process against Defendant
2025-10-14 Defendant files declaratory judgment action in S.D.N.Y.
2026-01-16 Complaint Filing Date

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

U.S. Patent No. 9,927,672 - *“Multicolored pressure sensitive liquid crystal device”*

  • Patent Identification: U.S. Patent No. 9,927,672, issued March 27, 2018 (the “’672 Patent”).

The Invention Explained

  • Problem Addressed: The patent describes a market need for low-cost, low-power electronic writing devices that can capture and present text and images in multiple colors, mimicking the use of colored pens on paper without the associated expense and mess (’972 Patent, col. 1:19-27). Prior art devices were often limited to a single reflective color against a dark background (’972 Patent, col. 1:12-14).
  • The Patented Solution: The invention provides a single pressure-sensitive liquid crystal layer capable of displaying different colors at different locations (’972 Patent, Abstract). This is achieved by creating distinct "color regions" within a single layer of a cholesteric liquid crystal and polymer dispersion, where each region is specifically tuned to reflect a different wavelength (color) of light when pressure is applied (’972 Patent, col. 12:3-9; Fig. 7A). This pressure-induced change in reflectance creates a written image without requiring complex stacked display layers or high-resolution color filters (’972 Patent, col. 6:10-16).
  • Technical Importance: The single-layer approach to a multicolor display suggests a method for manufacturing such devices that could be simpler and more cost-effective than alternative technologies requiring multiple, precisely aligned layers to achieve a similar visual effect (’972 Patent, col. 6:28-30).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 24 (Compl. ¶¶ 22, 35).
  • Essential elements of independent Claim 1 include:
    • A flexible, transparent first substrate and a second substrate spaced apart from the first.
    • First and second electrically conductive layers disposed between the substrates.
    • A pressure-sensitive liquid crystal layer comprising a dispersion of cholesteric liquid crystal and polymer, disposed between the conductive layers.
    • The liquid crystal layer includes at least a first color region and a second color region, each adapted to reflect light of a different color.
    • Pressure applied to the first substrate causes a change in reflectance, displaying the first color over the first region and the second color over the second region.
    • This multicolor image is formed without voltage being applied.

III. The Accused Instrumentality

Product Identification

  • Defendant’s "LCD Writing Tablet for Kids" (the "TQU product") (Compl. ¶12).

Functionality and Market Context

  • The TQU product is described as an LCD writing tablet that uses "pressure-sensitive technology" allowing a user to "draw lines of different thicknesses through different pressure levels" (Compl., p. 5). The complaint includes a marketing screenshot indicating the device has a "Colorful Screen" and is intended as an educational and entertainment toy for children (Compl., p. 7). Visual evidence provided shows the device producing multicolored text and drawings on its screen in response to a stylus (Compl., p. 3). The complaint alleges the product is sold online via Amazon (Compl. ¶13).

IV. Analysis of Infringement Allegations

’672 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a first transparent substrate that is flexible on which a pressure is applied and a second substrate spaced apart from said first substrate The product has a transparent and flexible first substrate on its display screen surface, to which a user applies pressure with a stylus, and a second substrate spaced apart on the inside from the first substrate. ¶26 col. 6:45-50
a first electrically conductive layer and a second electrically conductive layer that are disposed between said first substrate and said second substrate...said first electrically conductive layer being transparent The product has transparent first and second electrically conductive layers between the first and second substrates. ¶28 col. 6:50-55
a pressure sensitive liquid crystal layer comprising a dispersion of cholesteric liquid crystal and polymer... The product has a pressure-sensitive liquid crystal layer with a dispersion of cholesteric liquid crystal and polymer, demonstrated by lines appearing when a user presses on the display with a stylus. ¶30 col. 6:20-24
wherein said liquid crystal layer includes at least a first color region and a second color region...said first color region being adapted to reflect light of a first color and said second color region being adapted to reflect light of a second color The product has multiple color regions comprising dispersions of cholesteric liquid crystal and polymer, with these regions each reflecting light of different colors. ¶32 col. 12:3-9
wherein the pressure applied...causes said liquid crystal layer to display said first color...and to display said second color...to form a multicolor image, wherein voltage is not applied to form the multicolor image Pressure applied by a user results in a change in reflectance of the liquid crystal, causing it to change color across the different color regions and form a multicolor image. The complaint shows an image of multicolored text on the device (Compl., p. 8). ¶34 col. 18:10-18
  • Identified Points of Contention:
    • Evidentiary Questions: The complaint alleges the accused product’s display contains "a dispersion of cholesteric liquid crystal and polymer" (Compl. ¶30). A central question for the court will be what technical evidence, such as from a product teardown or materials analysis, Plaintiff can produce to substantiate this claim regarding the specific composition of the accused device's active layer.
    • Scope Questions: The complaint's visual evidence shows the accused product producing a gradient of colors (Compl., p. 3). The interpretation of the term "color region" will be critical, specifically whether it requires discrete, bounded areas of color or if it can be construed to read on a display that produces a more continuous color spectrum.

V. Key Claim Terms for Construction

  • The Term: "dispersion of cholesteric liquid crystal and polymer"

  • Context and Importance: This term defines the core material science of the invention. The infringement analysis depends entirely on whether the accused product’s liquid crystal layer meets this specific technical definition. Practitioners may focus on this term as proof will require technical evidence beyond what is observable from the product's exterior.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification describes multiple methods for creating the dispersion, including "emulsification, polymerization induced phase separation, temperature induced phase separation, [and] solvent evaporation phase separation," suggesting the term is not limited to a single manufacturing process or resulting structure (’972 Patent, col. 2:50-55).
    • Evidence for a Narrower Interpretation: The detailed example provided in the patent describes a specific formulation made from a "blend of polymerizable monomer, crosslinker, photoinitiator, spacers and cholesteric liquid crystal mixtures" (’972 Patent, col. 17:28-32). A party could argue that the claim term should be limited to dispersions created from such specific precursor materials.

  • The Term: "color region"

  • Context and Importance: This term is central to the "multicolored" aspect of the patent. The dispute may turn on whether the accused product's display, which appears to show color gradients, contains distinct "regions" as required by the claim.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification states that "the color regions can be arranged in any order or pattern" and that the color change at a boundary "need not be a step function" but "can gradually change from green to yellow to red," which may support reading the term on displays with color gradients (’972 Patent, col. 12:60-64).
    • Evidence for a Narrower Interpretation: Figures 7A and 9 depict "color regions" as well-defined, discrete areas, such as parallel stripes (61, 62, 63) or distinct "islands" (71, 72, 73). A party could argue these embodiments define the term as requiring clearly demarcated zones of different color-reflecting properties.

VI. Other Allegations

  • Willful Infringement: The complaint alleges willful infringement based on Defendant's "lack of communication after receiving specific notice of infringement in the form of Amazon APEX" (Compl. ¶37). This alleges pre-suit knowledge of the patent and the alleged infringement.

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

  • A core issue will be one of evidentiary proof: What is the specific material composition and physical structure of the accused product's display layer? The case will likely depend on technical evidence establishing whether this layer constitutes a "dispersion of cholesteric liquid crystal and polymer" with distinct "color regions" as claimed in the ’672 Patent.
  • A second key question will be one of definitional scope: Can the term "color region," which is described in the patent with examples of discrete stripes and islands, be construed to cover the color-graduated display functionality shown in the complaint's visual evidence of the accused product?
  • Finally, a central question of functional operation will arise: Does the accused product form its multicolor image purely through the application of pressure, as required by the claim limitation "wherein voltage is not applied to form the multicolor image," or does its operation involve an electrical field during the writing process?