iRobot Corp v. Bobsweep Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: iROBOT CORPORATION (Delaware)
  • Defendant: Bobsweep, Inc. (Canada), Bobsweep USA (Nevada), and SHENZEN SILVER STAR INTELLIGENT TECHNOLOGY CO., LTD. (China)
  • Plaintiff’s Counsel: FISH & RICHARDSON P.C.
• Case Identification: 1:17-cv-10651, D. Mass., 04/17/2017
• Venue Allegations: Plaintiff alleges venue is proper in the District of Massachusetts because Defendants purposefully ship products into the district and solicit customers via their own and third-party websites, placing products into the stream of commerce with the knowledge they will be purchased in the district.
• Core Dispute: Plaintiff alleges that Defendants’ robotic vacuum cleaners infringe patents related to optical obstacle and cliff detection, specific mechanical configurations for autonomous cleaning, and multi-mode coverage logic.
• Technical Context: The technology relates to autonomous robotic cleaning devices, a consumer electronics market characterized by competition over cleaning effectiveness, navigation intelligence, and operational efficiency.
• Key Procedural History: The complaint does not allege any significant procedural history, such as prior litigation or administrative challenges to the patents-in-suit.

Case Timeline

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

U.S. Patent No. 7,155,308 - "Robot Obstacle Detection System"

The Invention Explained

• Problem Addressed: The patent describes a need for a low-cost, accurate, and easy-to-implement obstacle detection system for autonomous robots, particularly to prevent them from driving off stairs or to enable smoother wall-following behavior, as prior art systems like sonar were complex and expensive while tactile sensors were inefficient (’308 Patent, col. 1:20-45).
• The Patented Solution: The invention is a sensor subsystem using an optical emitter (e.g., an infrared LED) and a photon detector. The emitter and detector are aimed at an angle so their respective fields of emission and view intersect at a predetermined region on the surface below the robot. The system operates on a simple binary logic: if a reflection is detected, the surface is presumed present; if no reflection is detected, the circuit concludes there is a "cliff" (like a stair edge) and redirects the robot to avoid it (’308 Patent, Abstract; col. 2:8-14).
• Technical Importance: This approach provided a cost-effective alternative to more complex navigation systems, enabling reliable cliff detection in mass-market consumer robots.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶27).
• The essential elements of claim 1 are:
  • An optical emitter that emits a directed optical beam with a defined field of emission.
  • A photon detector with a defined field of view that intersects the emitter's field of emission at a region.
  • A circuit connected to the detector that provides an output when an object is not present in the region, thereby re-directing the robot.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

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U.S. Patent No. 9,038,233 - "Autonomous Floor-Cleaning Robot"

The Invention Explained

• Problem Addressed: The patent addresses the need for an autonomous cleaning device that optimizes cleaning capability and efficiency while minimizing the power required, which is a critical constraint for battery-powered devices (’233 Patent, col. 1:20-31).
• The Patented Solution: The invention describes a floor-cleaning robot with a specific combination of components, including a primary brush, a cliff detector, and a powered side brush. A key aspect of the solution is the physical arrangement and design of the side brush, which has "bundles of bristles" separated by a "gap." This configuration is designed to allow the bristles to pass between the cliff detector and the floor during rotation without blocking the detector's optical beam, thus preventing a false positive cliff detection while still enabling the side brush to sweep debris from beyond the robot's main body (’233 Patent, Abstract; col. 8:27-56).
• Technical Importance: This design allows for the simultaneous operation of an extended-reach side brush and a non-contact cliff detector without mutual interference, enhancing both cleaning coverage and navigational safety.

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶43).
• The essential elements of claim 1 are:
  • A self-propelled floor-cleaning robot with a housing and a powered primary brush assembly.
  • A cliff detector configured to direct a beam toward the floor.
  • A powered side brush extending beyond the housing perimeter.
  • The side brush has bundles of bristles separated by a gap.
  • The gap is configured to prevent occlusion of the cliff detector beam during at least part of the side brush's rotation.
  • A particulate receptacle, an obstacle detector, and a control circuit to maneuver the robot.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

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U.S. Patent No. 8,474,090 - "Autonomous Floor-Cleaning Robot"

• Technology Synopsis: This patent discloses a floor-cleaning robot with a specific wheel suspension system. The invention addresses the problem of maintaining traction and stability on varied or uneven surfaces by attaching each drive wheel to the chassis via a pivoting arm, which is biased by a spring to an extended position. The robot's weight overcomes this spring force during operation, allowing the suspension to adapt to different floor heights and obstacles (’090 Patent, Abstract).
• Asserted Claims: At least independent claim 1 (Compl. ¶62).
• Accused Features: The complaint alleges that the wheel arrangement of the accused products, which allegedly includes wheels attached to the chassis via an arm and biased by a spring, infringes the ’090 Patent (Compl. ¶65). This allegation is supported by a photograph of a disassembled accused product (Compl. p. 17).

U.S. Patent No. 6,809,490 - "Method and System for Multi-Mode Coverage for an Autonomous Robot"

• Technology Synopsis: This patent addresses the "robot diffusion problem," where a robot with a purely random algorithm may fail to cover an entire cluttered space within a practical time (’490 Patent, col. 3:38-53). The solution is a behavior-based control system that allows the robot to operate in and select from a plurality of modes, such as a random "bounce" mode, an "obstacle following" mode, and a "spot-coverage" (spiraling) mode. By switching between these modes based on sensor input, the robot can achieve more effective and complete coverage of an unknown area (’490 Patent, Abstract).
• Asserted Claims: At least independent claim 1 (Compl. ¶81).
• Accused Features: The complaint alleges that the accused products’ control system is configured to operate in a plurality of modes—including spot-coverage, obstacle following, and bounce modes—which it selects in real time in response to its obstacle sensors (Compl. ¶¶83-84).

III. The Accused Instrumentality

Product Identification

• The accused products include the bObsweep Bob PetHair Plus, bObi Pet, bObi Classic, Bob PetHair, Bob Standard, and Junior robot vacuum cleaners, with the bObi Classic model used as the primary example (Compl. ¶24, n.1).

Functionality and Market Context

• The complaint alleges the accused products are autonomous robots that ride on a surface to perform floor cleaning (Compl. ¶29, ¶45). Their functionality is alleged to include sensor subsystems for navigation, including what are identified in product diagrams as "floor sensors," "wall sensors," and "touch sensors" (Compl. ¶29, ¶48, ¶83). An included image of the underside of the bObi Classic shows it is equipped with a main brush, a side brush, and floor sensors (Compl. p. 8). Another diagram shows the top of the device includes a "Head sensor," "Wall sensors," and "Touch sensors" (Compl. p. 14). The complaint alleges that Defendants compete directly with Plaintiff iRobot, positioning the accused products in the same market segment (Compl. ¶23).

IV. Analysis of Infringement Allegations

U.S. Patent No. 7,155,308 Infringement Allegations

• Identified Points of Contention:
  • Technical Questions: A central question may be whether the accused "floor sensors" operate using the specific intersecting-beam geometry required by the claim. The complaint alleges this functionality but does not provide direct evidence of the internal structure or specific optical path of the sensors.
  • Scope Questions: A potential dispute may arise over the definition of "region." The patent describes this as a finite intersection volume created by angled, collimated beams (’308 Patent, col. 6:18-22). The analysis may focus on whether the accused sensors create such a specific, limited "region" or use a different method of presence/absence detection.

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U.S. Patent No. 9,038,233 Infringement Allegations

• Identified Points of Contention:
  • Technical Questions: A key factual question will be whether the accused side brush is, in fact, "configured to prevent occlusion of the cliff detector beam." This is a negative limitation that may require evidence of the brush's design, rotation, and its specific interaction with the optical path of the adjacent "floor sensor." The visual evidence in the complaint shows the components' proximity but not their dynamic interaction (Compl. p. 12).
  • Scope Questions: The term "bundles of bristles" may be a point of construction. The court may need to determine how many bristles constitute a "bundle" and what physical characteristics define the "gap" between them, as these features are central to the non-occlusion function.

V. Key Claim Terms for Construction

Patent: U.S. Patent No. 7,155,308

• The Term: "region"
• Context and Importance: This term defines the specific location where the presence or absence of a surface is detected. Its construction is critical because infringement depends on whether the accused product's sensors create and monitor such a "region" through the claimed intersecting-beam method. Practitioners may focus on this term because it distinguishes the invention from general-purpose proximity sensors.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Claim 1 itself does not specify the size, shape, or precise angle of the intersection, referring only to "a region," which could suggest any area of overlap.
  • Evidence for a Narrower Interpretation: The specification repeatedly describes the region as "finite" and "predetermined," created by angled and collimated emitter and detector fields (’308 Patent, col. 2:10-12; col. 6:18-22). Figures 6 and 7 illustrate this specific geometric intersection, which could support a narrower construction limited to this physical arrangement.

Patent: U.S. Patent No. 9,038,233

• The Term: "gap being configured to prevent occlusion"
• Context and Importance: This functional language is the core of the asserted claim's novelty. The dispute will likely center on whether this requires a structure that always prevents occlusion under all operating conditions, or one that is merely designed with the intent and general capability of preventing occlusion.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language recites that the gap is configured to prevent occlusion "during at least part of the rotation," which may suggest that prevention does not need to be 100% effective throughout the entire rotation cycle.
  • Evidence for a Narrower Interpretation: The patent's detailed description emphasizes the problem of interference and presents the gapped-bristle design as the solution (’233 Patent, col. 8:46-56). This context suggests the "configured to prevent" language requires a structure that reliably achieves the non-occlusion function, not just one that incidentally might not occlude the beam.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement for each of the asserted patents. The basis for these allegations is that Defendants provide customers with technical guides, user manuals, demonstrations, and "How-To" videos that allegedly instruct and encourage users to operate the accused products in an infringing manner (Compl. ¶31, ¶49, ¶68, ¶85).
• Willful Infringement: The complaint states that Plaintiff "reserves the right to request" a finding of willfulness "to the extent facts learned in discovery show that one or both Defendants' infringement... is or has been willful, including following the filing of this Complaint" (Compl. ¶25). This framing alleges at least post-suit knowledge of the patents and infringement, forming a basis for potential willfulness damages from the date of service forward.

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

• A central issue will be one of technical operation: Do the accused "floor sensors" function via the specific intersecting optical beam geometry claimed in the ’308 Patent, or do they use a different, non-infringing method to detect cliffs? The case may require detailed analysis of the internal components and optical paths of the accused sensors.
• A key evidentiary question will be one of functional performance: Does the physical structure of the accused product's side brush—specifically the spacing between its bristle tufts—actually "prevent occlusion" of the adjacent cliff detector's beam during operation as required by the ’233 Patent? Proving this negative limitation may depend on expert testimony and testing that demonstrates the dynamic interaction between the components.
• A broader theme will be one of design-around vs. copying: The case will likely explore whether the accused products represent legitimate competition using alternative technical solutions to common problems in robotic cleaning, or if their specific combination of features—from optical sensors to multi-mode logic and spring-biased wheels—is evidence of infringement of Plaintiff's patented systems.