PTAB

IPR2025-01315

Samsung Electronics America Inc v. Maxell Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Signal Processor
  • Brief Description: The ’950 patent discloses a signal processor for use in imaging devices. The technology is directed to improving camera control functions, such as autofocus or auto-exposure, by identifying and removing pixels with certain problematic features (e.g., high luminance) from an evaluation region before calculating adjustments.

3. Grounds for Unpatentability

Ground 1: Claims 1-15 are obvious over Tsujino in view of Iwasaki.

  • Prior Art Relied Upon: Tsujino (Patent 8,237,850) and Iwasaki (Application # US2007/0189758).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tsujino disclosed all limitations of the independent claims. Specifically, Tsujino’s camera system included a CPU that functions as a "feature detection unit" by identifying high-luminance pixels that exceed a predefined threshold. Tsujino’s system then created a new evaluation region by excluding these identified pixels from further consideration for autofocus (AF) calculations, satisfying the "region creation unit" limitation. Finally, Tsujino’s CPU acted as a "control unit" that adjusted camera settings based on evaluated values extracted from this modified, non-excluded region. Petitioner contended that Iwasaki supplemented these teachings by disclosing a similar technique of excluding high-luminance subject groups from calculations for auto-exposure (AE) control, reinforcing the patented concept.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references because they both addressed the common problem of improving camera performance in challenging lighting conditions. A POSITA would have been motivated to integrate Iwasaki’s AE solution with Tsujino’s AF solution to create a more comprehensive camera system capable of handling both focus and exposure accurately in the presence of bright spots.
    • Expectation of Success: Petitioner asserted a reasonable expectation of success because both references employed similar and compatible technologies, including image sensors, CPUs, and software-based algorithms for luminance evaluation and region-based analysis.

Ground 2: Claims 1-15 are obvious over Tsujino in view of Shui and Iwasaki.

  • Prior Art Relied Upon: Tsujino (Patent 8,237,850), Shui (Japanese Publication No. 2007-25559), and Iwasaki (Application # US2007/0189758).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground asserted that Shui provided an alternative, well-known method for implementing the "feature detection" and "region creation" functionalities taught by Tsujino. Petitioner argued that Shui disclosed a more sophisticated technique for detecting problematic pixels by not just using a simple luminance threshold, but by analyzing focus evaluation value peaks and calculating photometric differentials around those peaks. This differential-based approach allowed Shui to distinguish true focus points from false peaks caused by bright light sources. Shui also taught dividing the focus area into discrete regions and excluding those regions determined to contain unwanted features, aligning with the claimed "region creation" functionality.
    • Motivation to Combine: A POSITA would combine the references to improve upon the basic system of Tsujino. Specifically, a POSITA would integrate Shui's more precise differential-based detection method into Tsujino's framework to enhance the system's ability to handle high-luminance point light sources, a known problem in the art. The combination with Iwasaki remained motivated for the reasons stated in Ground 1—to provide a comprehensive AF and AE solution.
    • Expectation of Success: The combination was asserted to be predictable because all three references operate in the same technical field of digital camera image processing and utilize standard, compatible hardware components and software-based image analysis techniques.
  • Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1-15 based on the combination of Shui and Iwasaki, relying on a similar motivation to combine complementary AF (from Shui) and AE (from Iwasaki) techniques.

4. Key Claim Construction Positions

  • Petitioner dedicated a substantial portion of its argument to the construction of several "unit" terms recited in the claims (e.g., "feature detection unit," "region creation unit," "control unit," "processing unit").
  • Petitioner argued that these terms lacked sufficiently definite structure and should be construed as means-plus-function limitations under 35 U.S.C. §112, ¶6.
  • The corresponding structure for performing the claimed functions (e.g., "detecting a position," "creating a region") was identified as the software algorithms described in the ’950 patent's specification, which execute on a general-purpose processor. This construction was central to Petitioner's obviousness arguments, as the prior art references were alleged to disclose equivalent software algorithms performing the same functions.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-15 of Patent 8,471,950 as unpatentable under 35 U.S.C. §103.