Patent Armory Inc. v. Monoprice, Inc.

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Patent Armory Inc. (Canada)
  • Defendant: Monoprice, Inc. (California)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 6:23-cv-00687, W.D. Tex., 09/27/2023
• Venue Allegations: Plaintiff alleges venue is proper because Defendant maintains an established place of business in the Western District of Texas and has committed acts of alleged infringement in the district.
• Core Dispute: Plaintiff alleges that certain of Defendant's products infringe a patent related to phased array sound systems that create localized regions of audible sound.
• Technical Context: The technology concerns systems that use a large array of speakers, each with a calculated time delay, to make sound waves constructively interfere at a specific target location, allowing sound to be heard clearly in one spot while remaining quiet elsewhere.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 7,130,430 - “Phased array sound system”

The Invention Explained

• Problem Addressed: The patent addresses the need for a cost-effective system to produce audible sound that is localized to a specific region, enabling multiple listeners in the same room to receive unique audio input without using headphones (’430 Patent, col. 2:7-11). This avoids the problem of general sound systems that fill an entire space and prevents different audio tracks from interfering with each other (’430 Patent, col. 1:21-36).
• The Patented Solution: The invention uses an array of speakers fed from a single audio source. Each speaker transmits the sound with a specific time delay calculated based on its distance to a selected target point in space (’430 Patent, col. 2:15-19). This timing ensures that the sound waves from all speakers arrive at the target location simultaneously and in-phase, causing constructive interference that significantly increases the audio volume at that specific point, while sound in other areas remains unintelligible or at a much lower volume (’430 Patent, col. 2:27-37; Fig. 1).
• Technical Importance: This approach provided a method for creating "audio spotlights" or personalized sound zones in public or shared spaces like museums or open-plan offices, a concept that was an area of active research at the time (’430 Patent, col. 1:30-36).

Key Claims at a Glance

• The complaint asserts infringement of one or more claims, with the referenced (but unattached) claim charts identifying "Exemplary ’430 Patent Claims" (Compl. ¶11). Independent claim 1 is representative.
• Independent Claim 1:
  • a multiplicity of audio frequency speakers;
  • at least one defined sound target spaced from each of the speakers;
  • wherein each speaker has a means for applying a time varying audio drive voltage which is substantially identical, except that each audio drive voltage is offset in time by an amount which is related to the distance between each speaker and the defined sound target;
  • so that substantially identical sound from each speaker reaches the sound target at the same time;
  • wherein the speakers are arranged in a single plane; and
  • further comprising a room having a ceiling, and wherein the speakers are mounted to the ceiling.
• The complaint does not explicitly reserve the right to assert dependent claims, but alleges infringement of "one or more claims" (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

The complaint refers to "Exemplary Defendant Products" but does not identify them by name or model number in the body of the complaint (Compl. ¶11). It states that these products are identified in claim charts attached as Exhibit 2, which was not publicly filed with the complaint (Compl. ¶16).

Functionality and Market Context

The complaint alleges that the accused products "practice the technology claimed by the ’430 Patent" (Compl. ¶16). Without access to the product list or claim charts in Exhibit 2, a detailed analysis of the accused functionality is not possible. The complaint contains no allegations regarding the products' commercial importance or market positioning.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint incorporates by reference claim charts from Exhibit 2, which is not included with the filing, and therefore a detailed claim chart summary cannot be constructed. The narrative infringement theory is summarized below.

Narrative Summary

The complaint alleges that Defendant’s "Exemplary Defendant Products" infringe the ’430 Patent because they "practice the technology claimed" and "satisfy all elements of the Exemplary ’430 Patent Claims" (Compl. ¶16). It alleges infringement both literally and under the doctrine of equivalents (Compl. ¶11). The complaint further alleges that Defendant’s employees directly infringe by internally testing and using the products (Compl. ¶12).

Identified Points of Contention

• Scope Questions: As the specific accused products are not identified, a primary question will be whether they meet the structural limitations of the claims, such as being part of a system with speakers "arranged in a single plane" and "mounted to the ceiling" as required by claim 1.
• Technical Questions: A central technical question will be whether the unidentified accused products in fact implement a time-delay mechanism for each speaker that is calculated based on the distance to a target point to achieve constructive interference, as required by the patent.

V. Key Claim Terms for Construction

The Term: "means for applying a time varying audio drive voltage" (Claim 1)

Context and Importance

This term is drafted in means-plus-function format under 35 U.S.C. § 112, ¶ 6. Its scope is limited to the corresponding structure disclosed in the specification and its equivalents. The infringement analysis will depend entirely on whether the accused products contain the specific structures disclosed in the ’430 Patent for performing the claimed function of applying a time-delayed voltage.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The function is broadly stated as "applying a time varying audio drive voltage." A party might argue this covers any component that achieves this result.
• Evidence for a Narrower Interpretation: The specification discloses a specific corresponding structure for this function: a system including a "computer or microprocessor (80)," an "A/D converter (72)," a "memory stack (76)" with storage registers, and a "pointer array (79)" that directs the retrieval of time-delayed digital audio samples which are then converted back to an analog drive voltage (’430 Patent, col. 6:33-65; Fig. 2). A court would likely limit the scope of this claim element to this disclosed structure and its equivalents.

The Term: "multiplicity" (Claim 1)

Context and Importance

Practitioners may focus on this term because its definition could determine whether a system with a small number of speakers falls within the claim's scope. The degree of constructive interference, and thus the effectiveness of the invention, is directly related to the number of speakers.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The term itself is not explicitly defined, potentially allowing it to mean any number greater than one.
• Evidence for a Narrower Interpretation: The specification repeatedly suggests a large number of speakers is required for the invention to work as intended. It describes arrangements of "hundreds to over one thousand discrete speakers" (’430 Patent, col. 3:61-62) and notes that sound intensity increases with the "square of the number of speakers employed" (’430 Patent, col. 2:32-33). An experimental setup used an 81-speaker array (’430 Patent, col. 8:9-10). This may support an interpretation that "multiplicity" requires a significantly large number of speakers.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials" that direct and encourage end users to use the products in an infringing manner (Compl. ¶14-15). The complaint references Exhibit 2 for these materials, which is not provided (Compl. ¶14).

Willful Infringement

Willfulness is not explicitly pleaded. The complaint alleges that service of the complaint itself provides "actual knowledge" of infringement, which could form the basis for a post-filing willfulness claim based on continued infringement (Compl. ¶13-14).

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

1. A central issue will be one of claim scope under means-plus-function: is the architecture of the accused products structurally equivalent to the specific computer, memory stack, and pointer system disclosed in the ’430 Patent for calculating and applying time-delayed audio signals?
2. A second key question will be definitional and factual: what are the specific accused products, and do they meet the structural limitations of claim 1, particularly the requirements that the speakers be "mounted to the ceiling" and that there be a "multiplicity" of them, a term whose meaning may be constrained by the patent’s emphasis on large arrays?
3. An evidentiary question for indirect infringement will be: what specific instructions in Defendant's product literature, if any, actively encourage users to set up and operate the sound systems in a manner that practices the patented method of creating localized sound at a defined target?