Cedar Lane Tech Inc v. Zhuhai Raysharp Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cedar Lane Technologies Inc. (Canada)
  • Defendant: Zhuhai RaySharp Technology Co., Ltd. (China)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 6:22-cv-01030, W.D. Tex., 10/04/2022
• Venue Allegations: Venue is alleged to be proper because Defendant is a foreign corporation, has committed acts of patent infringement in the district, and has caused harm there.
• Core Dispute: Plaintiff alleges that Defendant infringes two patents related to an interface architecture for transferring data from a CMOS image sensor to a host processor system.
• Technical Context: The technology addresses the challenge of efficiently interfacing image sensors with general-purpose processors by using on-chip memory to buffer image data, decoupling the sensor's fixed data rate from the processor's variable data access rate.
• Key Procedural History: The complaint does not mention prior litigation, IPR proceedings, or licensing history related to the patents-in-suit. The U.S. Patent 8,537,242 is a divisional of the application that led to U.S. Patent 6,972,790.

Case Timeline

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

U.S. Patent No. 6,972,790, "Host interface for imaging arrays," Issued December 6, 2005

The Invention Explained

• Problem Addressed: The patent describes a fundamental incompatibility between the continuous, synchronized "video style output" of conventional IC image sensors and the data interface of commercial microprocessors, which are designed for random access to memory. This mismatch traditionally required "additional glue logic," which increases system cost and complexity, diminishing the benefits of integrating sensors and processing elements on a single chip. (’790 Patent, col. 1:38-59).
• The Patented Solution: The invention proposes an interface, preferably integrated onto the same semiconductor die as the image sensor, that acts as a bridge between the sensor and a host processor system. (’790 Patent, col. 2:25-34). This interface uses a memory, such as a First-In First-Out (FIFO) buffer, to store image data as it is captured. When a sufficient amount of data accumulates in the memory, a signal generator alerts the processor (e.g., via an interrupt), which can then read the data from the memory at its own pace. (’790 Patent, col. 2:5-13; Fig. 2). This decouples the sensor's fixed capture rate from the processor's asynchronous data access.
• Technical Importance: This on-chip interface architecture was designed to reduce component count and system complexity, thereby helping to realize the "optimum cost benefit" of CMOS image sensor technology by integrating more functionality onto a single die. (’790 Patent, col. 1:60-64).

Key Claims at a Glance

• The complaint asserts infringement of exemplary claims from the ’790 Patent, identified in an external exhibit. (’790 Patent, Compl. ¶12). Independent claim 1 is representative of an apparatus claim and includes the following essential elements:
  • An interface for receiving data from an image sensor and for transfer to a processor system comprising:
  • a memory for storing imaging array data and clocking signals at a rate determined by the clocking signals;
  • a signal generator for generating a signal for transmission to the processor system in response to the quantity of data in the memory; and
  • a circuit for controlling the transfer of the data from the memory at a rate determined by the processor system.

U.S. Patent No. 8,537,242, "Host interface for imaging arrays," Issued September 17, 2013

The Invention Explained

• Problem Addressed: As a divisional of the '790 Patent, the ’242 Patent addresses the same technical problem of bridging the gap between image sensor output and processor system input without costly external logic. (’242 Patent, col.1:11-20, 1:43-50).
• The Patented Solution: While the '790 Patent claims an apparatus (the interface itself), the '242 Patent claims a method for processing imaging signals. The claimed method involves receiving and storing image data in a FIFO memory, using a counter to track the amount of stored data, comparing that count to a predefined limit, and, upon reaching that limit, generating an interrupt to signal a processor to begin transferring the data. (’242 Patent, Claim 1).
• Technical Importance: The method claims provide a different scope of protection, covering the specific sequence of operational steps for managing data flow from a sensor to a processor via an on-chip buffer.

Key Claims at a Glance

• The complaint asserts infringement of exemplary claims from the ’242 Patent, identified in an external exhibit. (Compl. ¶21). Independent claim 1 is a representative method claim and includes the following essential steps:
  • receiving image data from an imaging array;
  • storing the image data in a FIFO memory;
  • updating a FIFO counter to maintain a count of the image data in the FIFO memory in response to memory reads and writes;
  • comparing the count of the FIFO counter with a FIFO limit;
  • generating an interrupt signal to request a processor to transfer image data from the FIFO memory in response to an interrupt enable signal being valid and the count of the FIFO counter having a predetermined relationship to the FIFO limit; and
  • transferring image data from the FIFO memory to the processor in response to the interrupt signal.

III. The Accused Instrumentality

Product Identification

The complaint does not identify specific accused products in its main body. It refers to them as "Exemplary Defendant Products" that are identified in claim charts attached as Exhibits 3 and 4, which were not filed with the complaint. (Compl. ¶¶12, 17, 21).

Functionality and Market Context

The complaint does not provide any description of the accused products' functionality, operation, or market context. No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that the "Exemplary Defendant Products" infringe the asserted claims of the '790 and '242 patents. (Compl. ¶¶12, 21). The specific infringement theory is contained in claim charts (Exhibits 3 and 4) which are incorporated by reference but were not provided with the publicly filed complaint. (Compl. ¶¶18, 27). The complaint asserts that these charts demonstrate that the accused products "satisfy all elements" of the exemplary claims. (Compl. ¶¶17, 26). Without the exhibits, a detailed, element-by-element analysis of the infringement allegations is not possible.

V. Key Claim Terms for Construction

• The Term: "a signal generator for generating a signal for transmission to the processor system in response to the quantity of data in the memory" (’790 Patent, Claim 1)

• Context and Importance: This term is central to the invention's core function of alerting the processor. The dispute may turn on what constitutes "in response to the quantity of data." Practitioners may focus on whether this requires a direct measurement or threshold comparison, or if a more indirect relationship suffices.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself is broad, not specifying the mechanism of the response. The summary of the invention also uses general language, stating the signal is generated "in response to the quantity of data in the memory." (’790 Patent, col. 2:8-9).
  • Evidence for a Narrower Interpretation: The detailed description discloses specific embodiments where an "interrupt generator 48 compares the FIFO counter output Sc and the FIFO limit S_L." (’790 Patent, col. 6:11-12). This specific comparison could be argued to limit the scope of "in response to" to a threshold-based mechanism.

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

• Context and Importance: This term defines the second half of the invention's decoupling function: the processor, not the sensor, dictates the data transfer speed. The key question is what it means for the rate to be "determined by the processor system."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The language could be interpreted to mean any transfer initiated and managed by the processor, regardless of the precise control mechanism, fulfills this limitation.
  • Evidence for a Narrower Interpretation: The specification describes a "FIFO read control 47" that generates a read signal in response to signals from a "Chip Command Decoder 45," which in turn receives commands from the processor over the system bus. (’790 Patent, col. 6:50-62). This suggests a specific command-based system, which could be used to argue for a narrower construction than any processor-led activity.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement for both patents. It claims that Defendant distributes "product literature and website materials" that instruct end users to operate the accused products in a manner that infringes the patents. (Compl. ¶¶15, 24). The inducement allegation is premised on knowledge acquired "at least since being served by this Complaint." (Compl. ¶¶16, 25).
• Willful Infringement: The willfulness allegations appear to be based on post-suit conduct. The complaint alleges that "Despite such actual knowledge [from the service of the complaint], Defendant continues to make, use, test, sell, offer for sale, market, and/or import" infringing products. (Compl. ¶¶15, 24).

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

Given the limited detail in the complaint, the initial phase of the case will revolve around establishing the specific facts of infringement. The central questions that will emerge are:

1. Evidentiary Sufficiency: The primary immediate question is what specific products are accused and what evidence Plaintiff will produce from the (currently unavailable) claim charts and through discovery to show that the accused products’ architecture and methods map onto the claim elements of the '790 and '242 patents.
2. Claim Scope and Technical Operation: A core technical issue will be whether the mechanism within the accused products for managing data flow between their image sensor and processor falls within the scope of the claims. This will likely involve a dispute over the meaning of key terms, such as how the accused products "generate a signal in response to the quantity of data" and control transfer rates "determined by the processor system."
3. Apparatus vs. Method: A key legal and factual question will be how Plaintiff distinguishes its proof for the '790 apparatus claims versus the '242 method claims. The case will require evidence not only of the structure of Defendant's products (for the '790 patent) but also of their specific operational steps in practice (for the '242 patent).