Cedar Lane Tech Inc v. Skydio Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cedar Lane Technologies Inc. (Canada)
  • Defendant: Skydio, Inc. (Delaware)
  • Plaintiff’s Counsel: Napoli Shkolnik LLC; Rabicoff Law LLC
• Case Identification: 1:22-cv-01408, D. Del., 10/26/2022
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant is a Delaware corporation and has an established place of business in the district.
• Core Dispute: Plaintiff alleges that Defendant’s drone products infringe two patents related to an interface for managing data transfer between an image sensor and a host processor system.
• Technical Context: The patents address a foundational challenge in digital imaging: efficiently bridging the gap between the constant, high-speed data stream from a CMOS image sensor and the asynchronous, on-demand data access methods of a general-purpose processor.
• Key Procedural History: U.S. Patent No. 8,537,242 is a divisional of the application that matured into U.S. Patent No. 6,972,790 and is subject to a terminal disclaimer over the '790 Patent. The complaint does not mention any other prior litigation, licensing history, or administrative proceedings involving the patents-in-suit.

Case Timeline

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

U.S. Patent No. 6,972,790 - “Host interface for imaging arrays”

The Invention Explained

• Problem Addressed: The patent’s background section describes an incompatibility between the "video style output" of a CMOS image sensor, which produces a synchronized stream of pixel data, and the data interface of a commercial microprocessor, which is designed for random access to memory. Bridging this gap conventionally required "additional glue logic," which diminished the cost and integration benefits of using CMOS technology. ('790 Patent, col. 1:38-62).
• The Patented Solution: The invention proposes an interface, preferably integrated onto the same semiconductor die as the image sensor, to act as an intermediary. This interface uses a memory buffer (e.g., a FIFO) to receive and store data from the imaging array at the sensor's rate. Once a sufficient quantity of data has accumulated in the buffer, a signal generator alerts the host processor system, which can then read the data from the buffer at its own pace. ('790 Patent, Abstract; col. 2:3-14). This architecture decouples the rigid timing of the sensor from the more flexible processing schedule of the CPU.
• Technical Importance: This interface design simplifies the integration of CMOS image sensors into computer systems, reducing the need for bespoke external hardware and allowing for more efficient multitasking by the host processor. ('790 Patent, col. 1:59-66; col. 6:15-19).

Key Claims at a Glance

• The complaint does not specify which claims are asserted, instead referring to "Exemplary '790 Patent Claims" in an external exhibit not attached to the complaint (Compl. ¶12). Independent claim 1 is representative of the apparatus claimed.
• Independent Claim 1 includes the following essential elements:
  • An interface for receiving data from an image sensor and for transfer to a processor system.
  • A memory for storing imaging array data and clocking signals at a rate determined by the clocking signals.
  • A signal generator that generates a signal for the processor system in response to the quantity of data in the memory.
  • A circuit for controlling the transfer of data from the memory at a rate determined by the processor system.
• The complaint alleges infringement of "one or more claims," suggesting a reservation of the right to assert additional claims, including dependent claims (Compl. ¶12).

U.S. Patent No. 8,537,242 - “Host interface for imaging arrays”

The Invention Explained

• Problem Addressed: The '242 Patent, a divisional of the '790 Patent, addresses the same technical problem of incompatibility between image sensor data output and processor data input. ('242 Patent, col. 1:40-63).
• The Patented Solution: Rather than claiming the physical interface apparatus, this patent claims a method of processing the imaging signals. The claimed process involves receiving and storing image data in a FIFO memory, maintaining a count of the data in that memory, comparing the count to a predefined limit, and, upon reaching that limit, generating a signal (such as an interrupt or a bus request) to prompt a processor to transfer the buffered data. ('242 Patent, Abstract; col. 7:55-col. 8:28).
• Technical Importance: By claiming the method of operation, the '242 Patent provides a different layer of protection for the same core inventive concept, covering the use of a system configured according to the '790 Patent's teachings.

Key Claims at a Glance

• The complaint does not specify which claims are asserted, referring to "Exemplary '242 Patent Claims" in an external exhibit not attached to the complaint (Compl. ¶21). Independent method claims 1 and 8 are representative.
• Independent Claim 1 includes the following essential steps:
  • Receiving and storing image data in a FIFO memory.
  • Updating a FIFO counter to track the amount of data.
  • Comparing the counter to a FIFO limit.
  • Generating an "interrupt signal" to request data transfer by a processor.
  • Transferring the data from the FIFO memory to the processor in response to the signal.
• Independent Claim 8 is similar but claims generating a "bus request signal" to a "bus arbitration unit" instead of an "interrupt signal" to a processor.
• The complaint alleges infringement of "one or more claims," suggesting a reservation of the right to assert additional claims (Compl. ¶21).

III. The Accused Instrumentality

Product Identification

The complaint identifies the accused instrumentalities as the "Exemplary Defendant Products" but does not name specific Skydio products (Compl. ¶12, ¶21). The infringement allegations are detailed in external exhibits which were not filed with the complaint (Compl. ¶17, ¶26).

Functionality and Market Context

The complaint does not provide any technical description of the accused products' functionality or operation. It makes only conclusory allegations that the products "practice the technology claimed" by the patents-in-suit (Compl. ¶17, ¶26). Skydio, Inc. is a manufacturer of autonomous drones that rely on advanced computer vision, suggesting the accused functionality relates to the processing of image data from the drones' multiple cameras.

IV. Analysis of Infringement Allegations

The complaint incorporates infringement allegations by reference to claim chart Exhibits 3 and 4, which were not provided with the public filing (Compl. ¶18, ¶27). The narrative infringement theory is summarized below.

The complaint alleges that the accused Skydio products directly infringe the '790 Patent by containing a hardware interface that embodies the elements of the asserted claims. This theory suggests the products include a memory buffer for image data, a mechanism to signal a processor when the buffer reaches a certain fill level, and control circuitry that allows the processor to retrieve the buffered data (Compl. ¶12, ¶17).

For the '242 Patent, the complaint alleges that the accused products infringe by performing the patented method of handling image data. The theory suggests the products' operation involves storing incoming image data, monitoring the quantity of that data, and generating a system request (such as an interrupt or bus request) to initiate the transfer of the buffered data to a processor for use in, for example, navigation and imaging functions (Compl. ¶21, ¶26).

No probative visual evidence provided in complaint.

Identified Points of Contention

• Technical Questions: A primary question will be evidentiary: what specific components within the accused drones' highly integrated System-on-a-Chip (SoC) architecture correspond to the claimed "interface," "memory," and "signal generator"? Does the accused system operate by generating a specific "interrupt signal" or "bus request signal" as required by the '242 patent claims, or does it use an alternative data management architecture, such as a different type of direct memory access (DMA) or a polling scheme?
• Scope Questions: The dispute may raise questions about whether a single, multi-function processing core in a modern SoC can be said to contain the distinct "circuit for controlling the transfer" and "signal generator" as contemplated by the patent. The defense may argue that the accused architecture is technically distinct from the discrete functional blocks described in the patent specifications.

V. Key Claim Terms for Construction

• Term: "a circuit for controlling the transfer of the data... at a rate determined by the processor system" ('790 Patent, Claim 1)

  • Context and Importance: This term is central to the invention's core concept of decoupling the sensor from the processor. Infringement will depend on whether the accused products' data transfer mechanism is controlled by the main processor, as opposed to a dedicated DMA controller or the image sensor itself.
  • Intrinsic Evidence for a Broader Interpretation: The claim language itself is functional and does not impose structural limitations beyond "a circuit." This may support a construction covering any hardware configuration that performs the stated function of enabling processor-paced data reads. ('790 Patent, col. 8:12-14).
  • Intrinsic Evidence for a Narrower Interpretation: The specification describes specific embodiments with distinct components, including a "FIFO read control" unit (47) and a "Chip Command Decoder" (45) that responds to the CPU. ('790 Patent, col. 6:49-68; Fig. 2). Parties may argue that the claimed "circuit" should be construed to require a structure analogous to these disclosed embodiments.

• Term: "generating an interrupt signal" ('242 Patent, Claim 1)

  • Context and Importance: This term specifies the mechanism for alerting the processor. The case may turn on whether the accused system uses a true hardware interrupt as that term is understood in computer architecture, or another type of status signaling.
  • Intrinsic Evidence for a Broader Interpretation: The term could be interpreted functionally to mean any signal that causes the processor to suspend its current operations to service the data transfer request.
  • Intrinsic Evidence for a Narrower Interpretation: The specification illustrates this signal being sent to the "CPU 10 via the interrupt bus 17," suggesting a specific type of hardware pathway. ('242 Patent, col. 5:14-17; Fig. 2). A defendant may argue the term is limited to this conventional implementation and does not cover software-based polling or other status-checking methods.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, asserting that since being served with the complaint, Defendant has knowingly and intentionally encouraged infringement by providing "product literature and website materials" that instruct customers on using the accused products in an infringing manner (Compl. ¶15-16, ¶24-25).
• Willful Infringement: The complaint alleges that Defendant has had "actual knowledge" of the patents at least since the filing of the lawsuit and has continued to infringe despite this knowledge (Compl. ¶14-15, ¶23-24). While the word "willful" is not used, this allegation forms a basis for seeking enhanced damages under 35 U.S.C. § 284. The prayer for relief also requests that the case be declared "exceptional" under 35 U.S.C. § 285, which would permit an award of attorneys' fees (Compl. p. 7, ¶G.i).

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

• Evidentiary Mapping: A core issue will be one of evidentiary mapping: can Plaintiff produce technical evidence, likely from reverse engineering, to show that the complex, integrated System-on-a-Chip (SoC) in the accused drones contains structures that perform the specific functions of the discrete "memory," "signal generator," and "control circuit" elements as recited in the '790 patent's claims?
• Operational Equivalence: A key question for the '242 patent will be one of operational equivalence: does the accused system's method for managing data flow from its sensors rely on "generating an interrupt signal" or a "bus request signal" as claimed, or does it employ a fundamentally different, non-infringing technical approach to alert the processor and manage data transfer?
• Scope of "Interface": The case may hinge on the definitional scope of the claimed "interface." Can this term, described in the patent as a bridge between a sensor and a processor, be construed to read on a set of functions that are entirely subsumed within a single, multipurpose processing unit, or must it be a structurally or logically distinct component?