Coretronic Corp v. Maxell Ltd

Prosecution History analysis

Examiner Search analysis

Invalidity Framework analysis

Petition

Petition summary

## 1. Case Identification
- Case Number: [IPR2025-00942](https://ai-lab.exparte.com/case/ptab/IPR2025-00942)
- Patent #: [9,900,569](https://ai-lab.exparte.com/patent/9900569)
- Filed: May 14, 2025
- Petitioner(s): [Coretronic Corporation](https://ai-lab.exparte.com/party/coretronic-corp), [Optoma Corporation](https://ai-lab.exparte.com/party/optoma-technology-inc)
- Patent Owner(s): [Maxell, Ltd](https://ai-lab.exparte.com/party/maxell-ltd).
- Challenged Claims: 1-4

## 2. Patent Overview
- Title: Projection-Type Image Display Apparatus
- Brief Description: [The ’569 patent](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1001) relates to a projection-type image display apparatus that uses a discharge lamp as a light source. The system is designed to automatically adjust image quality based on the detected lamp voltage to compensate for lamp degradation over time, while also providing a menu for user-selectable image 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](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) (Application # US20100289429A1), [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006) (Application # US20130215135A1).
- **Core Argument for this Ground:**
    - **Prior Art Mapping:** Petitioner argued that [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) taught the core components of a projector with a discharge lamp, a lamp voltage detection unit, and a control unit that adjusts lamp power to maintain a constant light flux based on the detected voltage. [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006) was argued to teach a projector with a user-facing on-screen display (OSD) menu that allows a user to adjust various image quality parameters (e.g., brightness, contrast, color mode) independent of any automatic system. The combination of [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005)'s automatic, voltage-based correction system with [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006)'s user-driven menu system allegedly disclosed all elements of independent claim 1.
    - **Motivation to Combine:** A Person of Ordinary Skill in the Art (POSITA) would combine the automatic brightness stabilization taught by [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) with the user-configurable image quality settings taught by [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006). This combination would be a predictable integration to enhance projector performance and user experience by providing both consistent long-term brightness and customizable image quality, a common practice in the industry as evidenced by products like the BenQ MX823ST projector.
    - **Expectation of Success:** A POSITA would have a reasonable expectation of success in combining these known features, as it involved the integration of conventional projector functionalities (automatic control and user menus) to achieve 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](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) (’429 application), [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006) (’135 application), [Abe](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1007) (JP2008122746A), [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008) (JP2005241708A).
- **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 usage period" for correction. Petitioner asserted that [Abe](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1007) taught tracking cumulative lamp usage time and its correlation to increasing lamp voltage. [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008) was argued to teach adjusting lamp power based on cumulative lighting time to compensate for brightness degradation. The teachings of [Abe](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1007) and [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008) supplied the missing elements of claims 2 and 3.
    - **Motivation to Combine:** A POSITA, starting with the base system from Ground 1, would be motivated to incorporate the teachings of [Abe](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1007) and [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008) to create a more sophisticated correction system. It was a known problem that lamp characteristics change with age (usage time), and using the lamp usage period in addition to voltage for correction was a known technique to improve the accuracy of brightness compensation over the lamp's entire lifespan.
    - **Expectation of Success:** Integrating usage-time-based correction with voltage-based correction was a well-understood and predictable improvement for projector systems, yielding the expected benefit of more stable image quality over time.

#### Ground 3: Obviousness over Pollmann-Retsch, CP-DX300 Service Manual, and CP-DX300 User Manual - 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](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) (’429 application), Hitachi CP-DX300 Service Manual ([CP-DX300-SM](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1011)), Hitachi CP-DX300 User Manual ([CP-DX300-UM](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1012)).
- **Core Argument for this Ground:**
    - **Prior Art Mapping:** Petitioner argued that the Hitachi CP-DX300 projector, a commercially available product, embodied the claimed invention when viewed in light of [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005)'s teachings. The [CP-DX300-UM](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1012) (User Manual) was argued to disclose the claimed "menu screen creating unit" and the user-settable image quality adjustments (the "second setting item"). The [CP-DX300-SM](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1011) (Service Manual) allegedly disclosed the internal hardware, including the main processor (DLP DDP4421) and ballast board processors, that function as the lamp driving unit, control unit, and lighting period managing unit, capable of tracking lamp hours and adjusting illuminance. [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) supplied the explicit teaching of using detected lamp voltage to control an amount of correction (the "first setting item").
    - **Motivation to Combine:** A POSITA would be motivated to apply the automatic brightness correction method of [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005) to a standard commercial projector like the Hitachi CP-DX300. The manuals demonstrated that the projector already possessed all the necessary hardware components and user interface features, making the integration of a voltage-based feedback loop a straightforward and obvious improvement to enhance functionality.
    - **Expectation of Success:** Implementing a known automatic correction technique on a device with the requisite hardware and software infrastructure would have been an obvious and predictable modification with a high expectation of success.
- **Additional Grounds:** Petitioner asserted additional obviousness challenges, including a challenge to claim 4 over [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005), [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006), and [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008), and a challenge to claims 2-3 over [Pollmann-Retsch](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1005), [Hirabayashi](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1006), [Kambara](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1009), and [Ishitani](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1008), which relied on similar principles of combining known lamp-aging compensation techniques.

## 4. Relief Requested
- Petitioner requests institution of an inter partes review and cancellation of claims 1-4 of [the ’569 patent](https://ai-lab.exparte.com/case/ptab/IPR2025-00942/doc/1001) as unpatentable.

Projector lamp patent challenged for obviousness: prior art cites Hitachi manuals for claims 1-4 on automatic image correction via lamp voltage.