DCT
1:17-cv-10648
iRobot Corp v. Black & Decker Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: iRobot Corporation (Delaware)
- Defendant: The Black & Decker Corporation (Maryland), Black & Decker (U.S.) Inc. (Maryland), and Shenzhen Silver Star Intelligent Technology Co., Ltd. (China)
- Plaintiff’s Counsel: Fish & Richardson P.C.
- Case Identification: 1:17-cv-10648, D. Mass., 04/17/2017
- Venue Allegations: Plaintiff alleges venue is proper in the District of Massachusetts because Defendants Black & Decker transact business and have committed acts of infringement in the district, and Defendant Shenzhen Silver Star Intelligent Technology manufactures and imports infringing devices that are marketed and sold to consumers in the district through a nationwide distribution channel.
- Core Dispute: Plaintiff alleges that Defendant’s robotic vacuum cleaners infringe patents related to optical obstacle detection systems, mechanical wheel suspension for autonomous robots, and multi-mode coverage control systems.
- Technical Context: The case concerns technology fundamental to autonomous robotic vacuums, a competitive and growing segment of the consumer electronics market.
- Key Procedural History: No prior litigation, licensing history, or other significant procedural events are mentioned in the complaint.
Case Timeline
| Date | Event |
|---|---|
| 2001-06-12 | U.S. Patent No. 6,809,490 Priority Date |
| 2003-06-03 | U.S. Patent No. 7,155,308 Priority Date |
| 2004-10-26 | U.S. Patent No. 6,809,490 Issued |
| 2006-12-26 | U.S. Patent No. 7,155,308 Issued |
| 2008-08-29 | U.S. Patent No. 8,474,090 Priority Date |
| 2013-07-02 | U.S. Patent No. 8,474,090 Issued |
| 2017-04-17 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,155,308 - “Robot Obstacle Detection System” (issued Dec. 26, 2006)
The Invention Explained
- Problem Addressed: The patent identifies a need for a low-cost, accurate, and easy-to-implement obstacle detection system for autonomous cleaning robots, noting that prior art systems like sonar were too complex and expensive for the consumer market, while tactile sensors were inefficient (Compl. ¶13; ’308 Patent, col. 1:19-51).
- The Patented Solution: The invention proposes a sensor subsystem that uses an optical emitter (e.g., an infrared LED) and a photon detector. The emitter sends out a directed beam, and the detector has a defined field of view. These two fields are angled to intersect at a specific, finite region on the surface (the floor) just ahead of the robot. The system is designed to detect the absence of the floor in that region; if no reflection is detected, the circuit concludes there is a "cliff" (like a stair) and redirects the robot to avoid a fall (’308 Patent, Abstract; col. 2:8-18).
- Technical Importance: This approach provides a simple, non-contact method for "cliff detection," a critical safety and operational feature for consumer-grade robots intended for use in multi-level homes (Compl. ¶13).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 (Compl. ¶25).
- Claim 1 requires:
- A sensor subsystem for an autonomous robot that rides on a surface.
- 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 that provides an output to re-direct the robot when an object is not present in that region.
U.S. Patent No. 8,474,090 - “Autonomous Floor-Cleaning Robot” (issued July 2, 2013)
The Invention Explained
- Problem Addressed: While not explicitly stated as a problem in the patent's background, the detailed description and claims focus on a self-adjusting cleaning head and a specific wheel suspension mechanism, suggesting a need for robots to better maintain cleaning performance while traversing varied floor surfaces and small obstacles (’090 Patent, col. 1:15-22).
- The Patented Solution: The patent describes a specific mechanical arrangement where each of the robot's main drive wheels is attached to the chassis via a pivoting arm. A spring biases this arm, pushing the wheel downward into an "extended position." During normal operation on a flat surface, the robot's weight is sufficient to overcome this spring force, compressing the suspension. This design allows the wheels to move vertically, adapting to changes in surface height (e.g., transitioning from a hard floor to a rug) or traversing small obstacles while aiming to keep the cleaning head in contact with the floor (’090 Patent, Abstract; col. 3:1-17).
- Technical Importance: A compliant suspension system enhances a robotic vacuum's mobility and cleaning effectiveness across the diverse surfaces found in a typical home, reducing the likelihood of the robot getting stuck or failing to clean certain areas (Compl. ¶¶15, 42).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 (Compl. ¶41).
- Claim 1 requires:
- A floor cleaning robot with a housing, chassis, wheels, motor, control module, obstacle sensor, and removable bin.
- A first rotating member to direct particulates toward the bin.
- Each wheel attached to the chassis via a respective arm.
- Each arm being pivotably attached to the chassis.
- Each wheel being biased to an extended position by a spring between the arm and chassis.
- A functional requirement that, during cleaning, the robot's weight "overcomes a force from the spring."
Multi-Patent Capsule: U.S. Patent No. 6,809,490 - “Method and System for Multi-Mode Coverage for an Autonomous Robot” (issued Oct. 26, 2004)
- Technology Synopsis: The patent addresses the challenge of ensuring an autonomous robot effectively covers an area of unknown geometry, a problem it terms the "robot diffusion problem" where a robot might neglect certain areas or become trapped (’490 Patent, col. 3:49-54). The patented solution is a control system that enables the robot to operate in a plurality of distinct behavioral modes—such as "spot-coverage mode," "obstacle following mode," and "bounce mode"—and to select between these modes in real-time based on signals from its obstacle detection sensors, thereby achieving more thorough coverage (’490 Patent, Abstract; Compl. ¶17).
- Asserted Claims: The complaint asserts infringement of at least independent claim 1 (Compl. ¶60).
- Accused Features: The complaint alleges that the accused product's control system is configured to operate in multiple modes, including a "spot mode," and to select among these modes in response to signals from its obstacle sensors (Compl. ¶¶62-63).
III. The Accused Instrumentality
Product Identification
The Black & Decker BDH5000 robotic vacuum cleaner, identified as the "Accused Product" (Compl. ¶22).
Functionality and Market Context
The BDH5000 is an autonomous robotic vacuum designed to navigate and clean floors (Compl. ¶27, 43). Its features, as described in the complaint, include sensor subsystems for navigation, motorized wheels, a rotating member to direct debris, and a removable dust bin (Compl. ¶¶27, 43, 46). The complaint alleges that SSSIT manufactures the device for B&D and that the product competes directly with iRobot's own line of robotic vacuums (Compl. ¶¶21-22). The complaint includes an image from the product's instruction manual identifying various components, including "Sensors" located on the underside of the device (Compl. p. 8).
IV. Analysis of Infringement Allegations
7,155,308 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| an optical emitter which emits a directed optical beam having a defined field of emission; a photon detector having a defined field of view which intersects the field of emission of the emitter at a region; | The BDH5000 includes sensor subsystems comprising at least one optical emitter and a photon detector whose fields of view and emission intersect. | ¶27 | col. 2:25-29 |
| and a circuit in communication with the detector providing an output when an object is not present in the region thereby re-directing the autonomous robot. | The BDH5000 sensor subsystem includes a circuit that provides a signal to re-direct the robot when an object, such as the floor, is not present in the region of intersection. | ¶27 | col. 2:30-34 |
Identified Points of Contention:
- Technical Questions: The complaint alleges on "information and belief" that the BDH5000's "sensors" perform the specific function of cliff detection recited in the claim (i.e., detecting the absence of a surface). A central evidentiary question will be whether the plaintiff can demonstrate this specific technical operation. The complaint provides a diagram from the product manual labeling part #19 as "Sensors," but offers no technical detail distinguishing them from simple forward-looking obstacle or bump sensors (Compl. p. 8).
- Scope Questions: The dispute may turn on whether the accused "sensors" create the claimed "region" of intersecting beams and whether the control circuit's output is triggered by an object not being present, as required for a cliff detector, versus an object being present, as in a standard proximity or bump sensor.
8,474,090 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| each of the wheels being attached to the chassis via a respective arm having a distal end and a proximal end; | Each of the wheels of the BDH5000 is attached to the chassis via an arm. | ¶44 | col. 3:1-4 |
| wherein each wheel is biased to an extended position away from the robot chassis by a spring extending between the arm and the robot chassis, | The wheels are biased to an extended position by a spring extending between the arm and the chassis. The complaint includes photographs of a disassembled BDH5000 that appear to show this mechanism (Compl. p. 12). | ¶44 | col. 3:12-15 |
| and wherein, during cleaning, the weight of the floor cleaning robot overcomes a force from the spring biasing the wheels to an extended position. | During cleaning, the weight of the BDH5000 is alleged to overcome the biasing force from the spring. | ¶44 | col. 3:15-17 |
Identified Points of Contention:
- Technical Questions: The complaint supports its allegations for the ’090 Patent with photographs from a disassembled BDH5000, which appear to show a wheel mounted on a pivoting arm with a biasing spring (Compl. p. 12). A potential point of contention will be whether this mechanism functions precisely as claimed. For example, what evidence establishes that the robot's static weight "overcomes" the spring force during normal operation, as opposed to the spring primarily serving as a shock absorber for larger impacts?
V. Key Claim Terms for Construction
For the ’308 Patent:
- The Term: "an object is not present in the region"
- Context and Importance: This is the core functional language that distinguishes a cliff detector from a proximity or bump sensor. The entire infringement theory for this patent rests on whether the accused device is triggered by the absence of the floor, rather than the presence of an obstacle. Practitioners may focus on this term because it defines the fundamental purpose of the claimed sensor.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself does not specify what the "object" is (or is not), potentially allowing it to read on scenarios beyond floor detection.
- Evidence for a Narrower Interpretation: The patent specification repeatedly frames the invention in the context of detecting a stair or drop-off by sensing when the "floor does not occupy the predefined region" (’308 Patent, col. 2:13-18). The accompanying figures, such as Figure 1 showing a robot at the edge of a "downward stair," reinforce that the intended object is the floor.
For the ’090 Patent:
- The Term: "overcomes a force from the spring"
- Context and Importance: This term sets a specific functional requirement for the relationship between the robot's weight and the spring's biasing force. Infringement requires not just the presence of a spring, but proof that this force-balance condition is met during normal "cleaning." A defendant could argue its spring is stiffer and primarily for shock absorption, and is not "overcome" by the robot's static weight.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification does not provide specific force values or spring constants, leaving the term open to a degree of functional interpretation based on the accused device's performance.
- Evidence for a Narrower Interpretation: The plain language of the claim and the abstract describes a clear sequence: the spring biases the wheel to an extended position, and the robot's weight then compresses it. This suggests the spring is designed to be overcome under static load, not just upon dynamic impact (’090 Patent, Abstract).
VI. Other Allegations
- Indirect Infringement: For all three asserted patents, the complaint alleges induced infringement against B&D. The basis for these allegations is that B&D provides "technical guides, product data sheets, demonstrations, specifications, [and] installation guides," such as the BDH5000 Instruction Manual, which allegedly instruct and encourage end-users to operate the accused product in an infringing manner (Compl. ¶¶28-29, 47-48, 64-65).
- Willful Infringement: The complaint states that Defendant B&D has actual knowledge of the asserted patents "at least as of service of this Complaint" (Compl. ¶¶29, 48, 65). It further includes a general reservation of rights to seek a finding of willful infringement should facts learned in discovery support such a claim (Compl. ¶23).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of evidentiary proof for sensor function: regarding the ’308 Patent, can the plaintiff provide technical evidence that the accused product's "sensors" operate as downward-looking cliff detectors that are triggered by the absence of a surface, or will discovery show they are conventional forward-looking proximity sensors?
- A second key question will be one of functional claim scope: for the ’490 Patent, does the operation of the accused product's "spot mode" and other cleaning patterns meet the specific definitions of the claimed "bounce mode," "obstacle following mode," and "spot-coverage mode," and does its control system switch between them in a manner that satisfies the claim limitations?
- Finally, the dispute over the ’090 Patent may center on mechanical equivalence: while the complaint provides compelling visual evidence of a spring-based suspension, a key question will be whether that mechanism meets the claim's functional requirement that the robot's weight "overcomes" the spring force during normal operation, or if there is a fundamental mismatch in its intended mechanical function.