Diversified Observation LLC v. Brother Intl Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Diversified Observation LLC (Texas)
  • Defendant: Brother International Corporation (Delaware)
  • Plaintiff’s Counsel: Stamoulis & Weinblatt LLC; Toler Law Group, PC
• Case Identification: 1:18-cv-00611, D. Del., 04/23/2018
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant is a Delaware corporation.
• Core Dispute: Plaintiff alleges that Defendant’s multifunction printers, which include scanning capabilities, infringe patents related to controlling scanner motor torque and compensating for light source instability during image capture.
• Technical Context: The patents address two common technical challenges in flatbed scanners: optimizing motor power for different scan resolutions and ensuring consistent image brightness.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patents-in-suit.

Case Timeline

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

U.S. Patent No. 6,414,461 - "Scanner that Controls Stepping Motor Torque," issued July 2, 2002

The Invention Explained

• Problem Addressed: The patent’s background section states that prior art scanners use a stepping motor with a fixed torque. When scanning at a higher resolution (which requires a slower scan speed), the motor generates surplus torque, leading to "excessive noise and shock" that can degrade image quality (ʼ461 Patent, col. 1:37-45).
• The Patented Solution: The invention proposes a control system that adjusts the stepping motor's torque based on the scanning requirements. The system uses a memory that stores a "torque table" containing multiple torque values, each corresponding to a specific condition (e.g., a scan resolution). A processor executes a "driving program" that selects the appropriate torque value from the table and sends a corresponding signal to the motor driving circuit. This allows the scanner to generate a high torque for low-resolution (fast) scans and a lower torque for high-resolution (slow) scans, optimizing performance and reducing noise (ʼ461 Patent, Abstract; col. 2:53-col. 3:15).
• Technical Importance: This approach allows for more efficient and quieter scanner operation by matching motor power to the specific task, a key refinement for devices offering multiple scan quality settings.

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. ¶11).
• Claim 1 Essential Elements:
  • A housing with a transparent platform.
  • A scanning module movably installed inside the housing.
  • A driving module with a stepping motor and a motor driving circuit.
  • A control circuit for controlling the scanner’s operations, which comprises:
    • a memory,
    • the memory storing a "torque table" and a "driving program,"
    • the torque table recording a plurality of torque values corresponding to a predetermined condition,
    • the driving program choosing one of the torque values, and the motor driving circuit receiving a corresponding signal to generate the chosen torque.
  • Wherein the control circuit controls the stepping motor to generate different torque so the scanning module scans at different speeds.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 6,522,432 - "Image Scanner with Automatic Signal Compensation," issued February 18, 2003

The Invention Explained

• Problem Addressed: The patent identifies that the light source in a scanner, such as a cold cathode fluorescent tube, is often unstable when first turned on, requiring a "warm-up" period of several minutes to achieve stable brightness. Scanning during this period can result in inconsistent image quality. Previous solutions using optic fibers to measure brightness were described as "very expensive and time consuming" to implement and sensitive to vibration (ʼ432 Patent, col. 1:11-37).
• The Patented Solution: The invention uses the scanner’s own image sensor to compensate for light source fluctuations. It incorporates a "test region" (e.g., a fixed white reference strip) inside the scanner, next to where the document is placed. The line image sensor scans this test region to generate a "brightness signal" and scans the document to generate an "image signal." A "signal compensation circuit" then uses the brightness signal as a baseline to adjust or amplify the image signal, correcting for any instability in the light source's output (ʼ432 Patent, Abstract; col. 5:55-col. 6:4).
• Technical Importance: This method provides a self-calibrating system for image brightness that avoids the cost and mechanical sensitivity of external optic fiber sensors by leveraging existing scanner components.

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. ¶27).
• Claim 1 Essential Elements:
  • A test region.
  • A light source for illuminating the document and the test region.
  • Optical means for conveying reflected light.
  • A line image sensor for receiving light and generating an "image signal" (from the document) and a "brightness signal" (from the test region), using an array of (R,G,B) sensing elements.
  • A "signal compensation circuit for amplifying the image signal according to the brightness signal" to compensate for light source instability. This circuit comprises:
    • an A/D converter for digitizing the (R,G,B) signals, and
    • a digital processor for adjusting the digitized (R,G,B) image signals according to the digitized (R,G,B) brightness signals.
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

The complaint names the Brother MFC-L6750DW and MFC-9330CDW as accused products, with detailed allegations focused on the MFC-L6750DW (Compl. ¶11).

Functionality and Market Context

The MFC-L6750DW is a multifunction device that includes a flatbed scanner. The complaint alleges that its scanner functionality incorporates the technologies of both patents-in-suit. Specifically, it is alleged to use a stepping motor controlled by a Toshiba TB6575FNG chip that varies motor output (Compl. ¶¶ 17-18), and an image capture system that uses an Asahi Kasei AK8456 chip to process and digitize signals from a contact image sensor (CIS) module (Compl. ¶¶ 31, 44). The complaint alleges the product's user documentation confirms that scanning speed is varied based on scan type and resolution, which is a feature tied to the infringement allegations for the '461 Patent (Compl. ¶23).

IV. Analysis of Infringement Allegations

U.S. Patent No. 6,414,461 Infringement Allegations

A photograph of the accused Toshiba controller chip is provided as evidence of the control circuit. (Compl. ¶18, p. 7). The complaint also includes a graph from a motor datasheet to support the allegation that different pulse rates result in different torque. (Compl. ¶23, p. 11).

Identified Points of Contention

• Scope Questions: A central question may be whether the functional mapping described in the accused controller's datasheet (voltage input controls PWM duty cycle) meets the structural requirement of a "memory storing a torque table." The defense may argue that a "torque table" implies a specific data structure that is not explicitly shown in the complaint's evidence.
• Technical Questions: What evidence demonstrates that the accused "control logic" (Compl. ¶20) is, in fact, the claimed "memory"? The complaint appears to equate the two without providing detailed analysis of the chip's architecture.

U.S. Patent No. 6,522,432 Infringement Allegations

The complaint provides oscilloscope waveforms allegedly showing the distinct RGB signals generated by the CIS module when scanning a red document pattern. (Compl. ¶37, p. 17). It also provides a block diagram from a service manual allegedly showing the circuitry of the "AFE + LED DRV" (Analog Front End and LED Driver). (Compl. ¶43, p. 22).

Identified Points of Contention

• Scope Questions: Does a general-purpose "Digital PGA" (Programmable Gain Amplifier) as alleged in the complaint meet the claim limitation of a "digital processor for adjusting the digitized (R,G,B) signals of the image signal according to the digitized (R,G,B) signals of the brightness signal"? The claim requires a specific causal relationship.
• Technical Questions: What evidence does the complaint provide to establish the functional link that the accused AK8456 chip actually uses the brightness signal from the test region to adjust the image signal? The complaint shows the chip is capable of processing signals and has a PGA, but the allegation that it performs the specific feedback/compensation function required by the claim may be a point of dispute.

V. Key Claim Terms for Construction

For the '461 Patent

• The Term: "torque table"
• Context and Importance: This term is central to the infringement theory for the '461 patent. The complaint alleges that the accused device's functional logic, which maps an input voltage to a motor duty cycle, constitutes the claimed "torque table" (Compl. ¶21). The case may depend on whether this functional mapping is equivalent to the patent's more structural-sounding term.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claims describe the table functionally as "recording a plurality of torque values" that correspond to a "predetermined condition" ('461 Patent, col. 5:8-10). Plaintiff may argue that any stored data or logic that performs this mapping function meets the claim's requirements, regardless of its specific implementation.
  • Evidence for a Narrower Interpretation: The patent’s detailed description and figures may support a more structural definition. Figure 7 explicitly shows a block labeled "Torque table" located within a larger "Memory" block, which is distinct from the "Processor" block ('461 Patent, Fig. 7). Defendant may argue this suggests a data structure, not just programmed logic.

For the '432 Patent

• The Term: "signal compensation circuit for amplifying the image signal according to the brightness signal"
• Context and Importance: This functional limitation defines the core novelty of the '432 patent: the causal link between measuring light source instability and correcting the final image. Proving that the accused circuit performs this specific function, rather than just generally processing signals, is critical for the plaintiff.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language is functional. Plaintiff may argue that any circuit architecture—such as the alleged ADC followed by a Digital PGA (Compl. ¶¶ 45-46)—that achieves the end result of adjusting the image based on brightness information infringes, as the claim does not dictate a specific circuit design.
  • Evidence for a Narrower Interpretation: The patent abstract states the circuit is for "amplifying the image signal according to the brightness signal to compensate the instability." ('432 Patent, Abstract). Defendant may argue this implies a direct feedback mechanism where the brightness signal actively controls the gain applied to the image signal, a specific function that may not be inherent in the general-purpose components alleged in the complaint.

VI. Other Allegations

• Indirect Infringement: The complaint does not provide sufficient detail for analysis of indirect infringement. The infringement counts cite only 35 U.S.C. § 271(a) for direct infringement (Compl. ¶¶ 11, 27).
• Willful Infringement: The complaint does not contain specific allegations of willful infringement or pre-suit knowledge of the patents. It does include a prayer for a declaration that the case is "exceptional" under 35 U.S.C. § 285, which could lead to an award of attorneys' fees (Compl. p. 24, ¶C).

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

1. A central issue for the '461 patent will be one of definitional scope: can the term "torque table," which the patent specification depicts as a distinct block within memory, be construed broadly enough to read on the functional logic of a controller chip that maps an input voltage to a motor output, as alleged in the complaint?

2. For the '432 patent, a key evidentiary question will be one of functional causality: does the complaint provide sufficient evidence that the accused signal processing chip performs the specific function of adjusting the image signal because of the measured brightness signal, or does it merely show a chip capable of processing both signals independently? The infringement determination will likely depend on establishing this direct operational link.