Prosperina Ventures LLC v. Keystone Tech LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Prosperina Ventures LLC (Texas)
  • Defendant: Keystone Technologies, LLC (Pennsylvania)
  • Plaintiff’s Counsel: Katz PLLC; Kent & Risley LLC
• Case Identification: 3:25-cv-02886, N.D. Tex., 10/23/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Northern District of Texas because Defendant has committed acts of patent infringement in the district and maintains a regular and established place of business, specifically a warehouse, within the district.
• Core Dispute: Plaintiff alleges that Defendant’s various LED light bulbs and lamps infringe six U.S. patents related to LED lamp design, thermal management, optical arrangements, and mechanical assembly.
• Technical Context: The dispute is in the highly competitive solid-state lighting market, where patented technologies for LED bulb efficiency, light distribution, and manufacturing are critical for creating commercially viable replacements for traditional incandescent, fluorescent, and HID lighting.
• Key Procedural History: The complaint does not mention any prior litigation between the parties, Inter Partes Review (IPR) proceedings concerning the patents-in-suit, or any prior licensing history.

Case Timeline

Date	Event
2010-06-08	Earliest Priority Date for U.S. Patent No. 10,107,487
2010-03-03	Earliest Priority Date for U.S. Patent No. 9,310,030
2011-04-25	Earliest Priority Date for U.S. Patent No. 9,470,882
2013-03-14	Earliest Priority Date for U.S. Patent No. 9,651,239
2013-06-28	Earliest Priority Date for U.S. Patent No. 9,222,659
2014-04-16	Earliest Priority Date for U.S. Patent No. 9,435,528
2015-12-29	U.S. Patent No. 9,222,659 Issued
2016-04-12	U.S. Patent No. 9,310,030 Issued
2016-09-06	U.S. Patent No. 9,435,528 Issued
2016-10-18	U.S. Patent No. 9,470,882 Issued
2017-05-16	U.S. Patent No. 9,651,239 Issued
2018-10-23	U.S. Patent No. 10,107,487 Issued
2025-10-23	Complaint Filed

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

U.S. Patent No. 9,222,659 - LED Lamp

• Issued: December 29, 2015 (the "'659 Patent")

The Invention Explained

• Problem Addressed: The patent describes the challenge of replacing traditional fluorescent tube lighting with more efficient LED-based lamps, particularly in a way that allows the new lamps to be installed in existing fixtures that use "tombstone connectors" (Compl. ¶34; ’659 Patent, col. 5:1-5).
• The Patented Solution: The invention is an LED lamp assembly, often in a tube-like form factor, that includes a pair of electrical pins mounted on a control member that can rotate independently of the main lamp enclosure ('659 Patent, abstract; '659 Patent, col. 12:11-25). This allows the lamp to be inserted into the fixed tombstone connectors of a fixture and then rotated to direct the light as needed, accommodating the directional nature of LEDs ('659 Patent, col. 12:28-30).
• Technical Importance: This design facilitates the "drop-in" replacement of fluorescent tubes with energy-efficient solid-state lighting without requiring costly replacement or rewiring of the entire fixture (Compl. ¶34).

Key Claims at a Glance

• The complaint asserts at least Claim 1 of the ’659 Patent (Compl. ¶34).
• The essential elements of independent Claim 1 include:
  • An enclosure that is at least partially optically transmissive.
  • At least one LED within the enclosure, operable through an electrical path.
  • A first pair of pins mounted in a control member.
  • The control member being "freely rotatable relative to the enclosure" and part of the electrical path.
• The complaint does not explicitly reserve the right to assert dependent claims but states infringement of "one or more claims" (Compl. ¶5).

U.S. Patent No. 9,310,030 - Non-uniform diffuser to scatter light into uniform emission pattern

• Issued: April 12, 2016 (the "'030 Patent")

The Invention Explained

• Problem Addressed: The patent addresses the fact that LED light sources typically produce a forward-directed, non-uniform light pattern (e.g., a "Lambertian profile"), which differs from the more desirable omnidirectional light of a traditional incandescent bulb ('030 Patent, col. 3:48-55).
• The Patented Solution: The invention is a lighting device that uses a specially designed diffuser spaced from the LED light source ('030 Patent, abstract). The diffuser alters the forward-directed light by having "varying scattering properties over its surface" or a shape that creates different distances between the light source and the diffuser at various angles, thereby creating a more uniform, omnidirectional emission pattern ('030 Patent, abstract; '030 Patent, col. 4:35-39).
• Technical Importance: This technology allows LED replacement bulbs to more closely mimic the aesthetic and functional light distribution of incandescent bulbs, which is a key factor for consumer acceptance in the general lighting market (Compl. ¶39).

Key Claims at a Glance

• The complaint asserts at least Claim 1 of the ’030 Patent (Compl. ¶39).
• The essential elements of independent Claim 1 include:
  • A solid-state light source emitting a substantially forward emission pattern.
  • A diffuser that alters the emission pattern to have greater uniformity.
  • The diffuser comprising a plurality of "diffuser attributes" to control the emission profile.
  • The diffuser comprising "varying scattering properties over its surface" based on the desired emission profile.
• The complaint does not explicitly reserve the right to assert dependent claims but states infringement of "one or more claims" (Compl. ¶5).

U.S. Patent No. 9,435,528 - LED Lamp with LED Assembly Retention Member

• Issued: September 6, 2016 (the "'528 Patent")
• Technology Synopsis: The patent describes a mechanism for securing an LED assembly onto a heat sink ('528 Patent, abstract). A retention member is used to restrain the LED assembly from axial movement and may place it under radial tension, which can ensure a robust mechanical and thermal connection to the heat conducting portion of the lamp ('528 Patent, abstract).
• Asserted Claims: At least Claim 1 (Compl. ¶44).
• Accused Features: The complaint accuses the Keystone A23 HID Bulb and substantially similar products of infringement (Compl. ¶44).

U.S. Patent No. 9,470,882 - Optical arrangement for a solid-state lamp

• Issued: October 18, 2016 (the "'882 Patent")
• Technology Synopsis: The patent relates to an optical system for a solid-state lamp that includes a primary optical element (such as a TIR lens) and a "highly reflective secondary reflector" located adjacent to, but not in contact with, the primary element ('882 Patent, abstract). This secondary reflector is designed to recapture and redirect stray light that escapes the primary optic, thereby improving the overall efficiency of the lamp ('882 Patent, col. 1:40-50).
• Asserted Claims: At least Claim 1 (Compl. ¶49).
• Accused Features: The complaint accuses various Keystone PAR and MR type bulbs of infringement (Compl. ¶49).

U.S. Patent No. 9,651,239 - LED Lamp and Heat Sink

• Issued: May 16, 2017 (the "'239 Patent")
• Technology Synopsis: The patent discloses a heat sink design for an LED lamp where an external portion comprises stems that support "overhangs" ('239 Patent, abstract). These overhangs extend over parts of the lamp's enclosure and base, which increases the available surface area for heat dissipation without significantly increasing the lamp's overall diameter ('239 Patent, col. 2:27-34).
• Asserted Claims: At least Claim 1 (Compl. ¶54).
• Accused Features: The complaint accuses the Keystone LED33PSPAR38 Bulb and the Keystone A23 HID Bulb, among others, of infringement (Compl. ¶54).

U.S. Patent No. 10,107,487 - LED light bulbs

• Issued: October 23, 2018 (the "'487 Patent")
• Technology Synopsis: This patent describes an "LED light engine" and methods of its fabrication. The invention involves patterning and mounting LEDs on a substantially planar substrate, which is then shaped (e.g., bent) to form a "substantially rigid upright support structure" ('487 Patent, abstract; '487 Patent, col. 2:42-61). This approach may reduce manufacturing complexity and cost compared to more traditional assembly methods ('487 Patent, col. 2:28-30).
• Asserted Claims: At least Claim 1 (Compl. ¶59).
• Accused Features: The complaint accuses a wide range of Keystone's LED bulbs of infringement, including MR16, G24, A23 HID, and PAR type bulbs (Compl. ¶59).

III. The Accused Instrumentality

Product Identification

• The complaint identifies a broad range of Defendant’s commercial LED lighting products, including the Keystone 26W 3500K G24 (No Ballast) Bulb, Keystone LED94P-V-850-S Bulb, Keystone A23 HID Bulb, and various MR16 and PAR series bulbs (Compl. ¶2). These are collectively referred to as the "Accused Products" (Compl. p. 2).

Functionality and Market Context

• The Accused Products are solid-state lighting devices, specifically LED bulbs and lamps, designed to serve as replacements for a variety of conventional lighting technologies such as Compact Fluorescent Lamps (CFL), High-Intensity Discharge (HID) lamps, and halogen PAR/MR lamps (Compl. ¶¶34, 39, 44, 49, 54, 59).
• The complaint alleges that these products are "marketed, offered, and distributed throughout the United States" (Compl. p. 2). The specific products targeted in each infringement count suggest they embody different form factors and technical features corresponding to the asserted patents (Compl. ¶¶34, 39, 44, 49, 54, 59).
• No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges direct and/or indirect infringement of at least claim 1 of each of the six patents-in-suit (Compl. ¶¶34, 39, 44, 49, 54, 59). For each patent, the complaint states that an exemplary claim chart is provided in an external exhibit (Compl. ¶¶35, 40, 45, 50, 55, 60). These exhibits were not attached to the publicly filed complaint. As such, the complaint itself does not provide a narrative theory or specific factual basis mapping claim elements to the features of the Accused Products.

• '659 Patent Infringement Allegations: The complaint alleges that the "Keystone 9.5W CCT Selectable 4-Pin CFL Replacement Bulb" and similar products infringe at least Claim 1, citing an exemplary claim chart in Exhibit 7 (Compl. ¶¶34-35).
• '030 Patent Infringement Allegations: The complaint alleges that the "Keystone PAR38 18W 5000K 2031 Lumens Bulb" and similar products infringe at least Claim 1, citing an exemplary claim chart in Exhibit 8 (Compl. ¶¶39-40).

Identified Points of Contention

• For the '659 Patent: A central factual question will be whether the accused CFL replacement bulbs incorporate a "control member" that is "freely rotatable relative to the enclosure" as required by Claim 1. The analysis will likely focus on the mechanical construction of the end caps and electrical pins of the accused bulbs.
• For the '030 Patent: A primary point of contention may be whether the diffusers on the accused PAR bulbs possess "varying scattering properties over its surface" as recited in Claim 1. This raises a technical question of whether the diffusers are commodity components with uniform properties or if they are specifically engineered with non-uniform characteristics to shape the light output in the claimed manner.

V. Key Claim Terms for Construction

"freely rotatable relative to the enclosure" ('659 Patent, claim 1)

• Context and Importance: This term is central to the infringement analysis for the '659 Patent, as it defines the key structural and functional feature of the invention. The scope of "freely rotatable" will determine whether the mechanism in the accused products meets this limitation. Practitioners may focus on this term because its construction will dictate whether a limited range of motion for installation constitutes infringement or if unconstrained rotation is required.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The plain language of the claim does not specify a required degree of rotation. The specification provides an example of rotating the pins by 90 degrees to engage electrical contacts, which may support an interpretation that "freely rotatable" includes any rotation sufficient for installation and orientation ('659 Patent, col. 12:20-22).
  • Evidence for a Narrower Interpretation: The detailed description and figures illustrate a specific assembly involving a "control member" (76) and a "plate" (90) that cooperate to achieve rotation ('659 Patent, Fig. 7; '659 Patent, col. 10:53-62). A party might argue that "freely rotatable" should be construed in the context of this disclosed mechanism, potentially limiting the claim's scope.

"varying scattering properties" ('030 Patent, claim 1)

• Context and Importance: This term is critical for the '030 Patent as it describes the technical means by which the patented diffuser achieves a uniform emission pattern. The dispute will likely turn on whether the accused diffusers exhibit this characteristic. Practitioners may focus on this term because its definition—whether it requires intentionally engineered material differences or includes incidental surface roughness—will be dispositive of infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification suggests this can be achieved through multiple means, including "changes in the scattering nature of the surfaces and/or variations in the amount of scattering material" ('030 Patent, col. 9:1-4). This language could support a broad definition that encompasses various methods of altering how light scatters across the diffuser's surface.
  • Evidence for a Narrower Interpretation: The patent provides specific examples, such as applying "non-uniform coatings" or a "thicker band coating" in specific regions of the diffuser ('030 Patent, col. 32:5-12). An argument could be made that "varying scattering properties" requires such deliberate, engineered non-uniformity, rather than inherent or incidental variations in a standard diffuser material.

VI. Other Allegations

• Indirect Infringement: The complaint includes boilerplate allegations of indirect infringement for each asserted patent (e.g., Compl. ¶34). However, it does not plead specific facts to support the requisite elements of knowledge and intent for either induced or contributory infringement.

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

• A core issue will be one of structural correspondence: For several of the patents, including the '659 Patent (rotatable pins), '528 Patent (retention member), and '239 Patent (overhanging heat sink), the case will turn on a direct, factual comparison of the mechanical structures in the accused bulbs against the specific components and arrangements recited in the claims. The question for the court will be whether Defendant’s designs are structurally equivalent to the patented inventions.
• A key evidentiary question will be one of material and optical properties: For patents like the '030 Patent (non-uniform diffuser) and the '882 Patent (secondary reflector), the central dispute will likely involve highly technical analysis. The case may depend on expert testimony and empirical evidence to determine if the materials and optical surfaces of the accused products perform the specific functions—such as possessing "varying scattering properties" or recapturing stray light—as required by the claims.
• A third question relates to inventiveness and scope across a portfolio: Given the assertion of six distinct patents against a broad product line, the case raises the question of whether Keystone’s standard LED bulb designs independently incorporate a multitude of specific, patented solutions, or whether the claims of Prosperina's patents are broad enough to cover more generalized or conventional approaches to LED lamp construction, thermal management, and optical design.