PTAB

IPR2025-00942

Coretronic Corp v. Maxell Ltd

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1. Case Identification

2. Patent Overview

  • Title: Projection-Type Image Display Apparatus
  • Brief Description: The ’569 patent describes a projection display apparatus that uses a discharge lamp as a light source. The system is designed to automatically adjust image quality parameters (e.g., brightness, contrast) by detecting the lamp's voltage, compensating for performance changes as the lamp ages, while also providing a menu for manual user adjustments.

3. Grounds for Unpatentability

Ground 1: Obviousness over Pollmann-Retsch and Hirabayashi - Claim 1 is obvious over Pollmann-Retsch in view of Hirabayashi.

  • Prior Art Relied Upon: Pollmann-Retsch (Application # 2010/0289429) and Hirabayashi (Application # 2013/0215135).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Pollmann-Retsch taught the core elements of independent claim 1, including a projection system with a discharge lamp, a lamp voltage detection unit, and a control unit that performs image correction by adjusting lamp power based on the detected voltage to maintain a consistent light flux. Petitioner contended that Hirabayashi taught the missing element: a menu screen creating unit, specifically an on-screen display (OSD) that allows a user to manually adjust image quality settings like brightness, contrast, and color.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Pollmann-Retsch's automatic, voltage-based brightness stabilization with Hirabayashi's user-facing menu for manual adjustments. This combination would predictably enhance projector performance and user experience by providing both consistent long-term brightness and customizable image quality. Petitioner asserted this combination reflects established industry practice, as evidenced by commercially available projectors.
    • Expectation of Success: Combining these known features was argued to be a straightforward integration of two distinct but complementary aspects of projector design (automatic performance maintenance and manual user control), leading to a predictable and desirable result.

Ground 2: Obviousness over Pollmann-Retsch, Hirabayashi, Abe, and Ishitani - Claims 2-3 are obvious over Pollmann-Retsch in view of Hirabayashi, Abe, and Ishitani.

  • Prior Art Relied Upon: Pollmann-Retsch (Application # 2010/0289429), Hirabayashi (Application # 2013/0215135), Abe (JP Publication # 2008122746A), and Ishitani (JP Publication # 2005241708A).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon Ground 1 to address the limitations of dependent claims 2 and 3. Claim 2 adds a "lighting period managing unit" and requires the control unit to use both lamp voltage and the lamp's accumulated usage period for correction. Petitioner asserted Abe taught a time measurement unit for tracking a lamp's cumulative usage and disclosed the known correlation between usage time and increasing lamp voltage. Ishitani was cited for teaching a lamp control circuit that adjusts lamp brightness based on cumulative lighting time to compensate for age-related degradation.
    • Motivation to Combine: A POSITA would recognize that lamp degradation is a function of both voltage and total usage time. It would have been obvious to enhance the voltage-only system of Pollmann-Retsch by incorporating the usage-time tracking and correction methods of Abe and Ishitani. This would create a more accurate and robust image correction system that accounts for multiple factors of lamp aging, yielding predictable improvements in performance.

Ground 3: Obviousness over Pollmann-Retsch and Hitachi Manuals - Claims 1-4 are obvious over Pollmann-Retsch in view of the CP-DX300 Service Manual and CP-DX300 User Manual.

  • Prior Art Relied Upon: Pollmann-Retsch (Application # 2010/0289429), the Hitachi CP-DX300 Service Manual (CP-DX300-SM), and the Hitachi CP-DX300 User Manual (CP-DX300-UM).

  • Core Argument for this Ground:

    • Prior Art Mapping: As an alternative to patent-based combinations, this ground argued that Pollmann-Retsch taught the base system of automatic lamp power correction based on voltage. The manuals for the commercially available Hitachi CP-DX300 projector were argued to collectively teach all other claimed features. The CP-DX300-UM disclosed a full-featured OSD for user adjustments (the "menu screen creating unit" for both automatic and manual settings), and the CP-DX300-SM revealed the internal components, including a main processor (DLP DDP4421) and ballast board processors that function as the control unit and "lighting period managing unit" by tracking lamp hours.
    • Motivation to Combine: A POSITA seeking to build a feature-rich projector would naturally look to improve the foundational automatic correction system of Pollmann-Retsch by incorporating the well-established, user-driven features found in a successful commercial product like the Hitachi CP-DX300. The motivation was to combine a known method for maintaining lamp performance with a known set of user interface features to create a superior and commercially viable product.
    • Expectation of Success: Since the Hitachi manuals demonstrate a working implementation of the manual control, menu, and usage tracking features, a POSITA would have a high expectation of success in integrating these known functionalities with the automatic correction system disclosed in Pollmann-Retsch.

  • Additional Grounds: Petitioner asserted additional obviousness challenges against claims 2-4 based on combinations of Pollmann-Retsch, Hirabayashi, Ishitani, and Kambara, relying on similar theories of combining automatic and usage-based correction mechanisms.

4. Relief Requested

  • Petitioner requests the institution of an inter partes review (IPR) and the cancellation of claims 1-4 of the ’569 patent as unpatentable.