Coretronic Corp v. Maxell Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Coretronic Corporation (Taiwan, R.O.C.) and Optoma Technology, Inc. (California)
  • Defendant: Maxell, Ltd. (Japan)
  • Plaintiff’s Counsel: Merchant & Gould P.C.
• Case Identification: 5:26-cv-00697, N.D. Cal., 01/22/2026
• Venue Allegations: Plaintiffs allege venue is proper based on Defendant Maxell’s business contacts in the district, including communications directed into the district regarding the alleged infringement and prior patent litigation filed by Maxell in the Northern District of California.
• Core Dispute: Plaintiffs seek a declaratory judgment that their Optoma-branded projectors do not infringe Defendant’s patent related to adjusting a projected image, and further allege the patent is invalid, unenforceable, and not owned by the Defendant.
• Technical Context: The dispute centers on technology for digital projectors that provides flexibility in positioning the projector relative to a screen without introducing image distortion.
• Key Procedural History: The complaint alleges a history of licensing discussions, including a letter from Maxell in April 2023, followed by meetings and communications. It also references parallel litigation filed by Maxell against Plaintiff Coretronic in the Eastern District of Texas and reports Maxell allegedly made to Amazon.com in January 2026 claiming infringement by Plaintiffs' products. The complaint further raises a significant challenge to Maxell’s standing to sue, alleging a defective patent assignment following a corporate merger.

Case Timeline

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

U.S. Patent No. 8,075,142 - “Projection-Type Image Display Apparatus,”

• Patent Identification: U.S. Patent No. 8,075,142, “Projection-Type Image Display Apparatus,” issued December 13, 2011.

The Invention Explained

• Problem Addressed: Conventional projectors require precise physical placement relative to a screen. Moving a projector, particularly in an oblique (angled) orientation, can cause trapezoidal distortion and other aberrations that degrade image quality and require time-consuming manual correction, limiting installation flexibility. (’142 Patent, col. 2:5-14).
• The Patented Solution: The invention proposes using an image display element (e.g., a liquid crystal panel) that has a larger display surface than the image being projected onto the screen. A "display controller portion" electronically moves the projected image's position within the larger surface of the display element. This allows the projected image to be repositioned to fit the screen perfectly, even if the projector itself is moved horizontally, without creating the geometric distortions associated with physical realignment. (’142 Patent, Abstract; col. 2:52-62). Figures 1A and 1B illustrate this concept, showing a smaller "actual image" (P') being selected from a larger "original image" (P) area available on the display element. (’142 Patent, Fig. 1A-1B).
• Technical Importance: This electronic adjustment method decouples the physical location of the projector from the precise positioning of the projected image, increasing the "degree of freedom of installation" for the apparatus. (’142 Patent, col. 2:20-24).

Key Claims at a Glance

• The complaint identifies independent claim 1 and dependent claims 3 and 4 as being at issue (Compl. ¶¶ 10, 45).
• Independent Claim 1 requires:
  • An enlarging projection optical unit to project an image from an image display element onto a display portion.
  • A display controller portion configured to move the image's position within the display surface of the image display element.
  • The enlarging projection optical unit having a lens group.
  • The display controller portion moving the image to display it within the display element's surface by "projecting a portion selectively fitted to the display portion."
• The complaint does not explicitly reserve the right to assert other claims, as it is a declaratory judgment action filed by the accused infringer.

III. The Accused Instrumentality

Product Identification

• The complaint identifies a wide range of "Optoma-branded projectors" sold by Plaintiffs Coretronic and Optoma, including models such as the GT2000HDR, 4K400STX, UHD35X, and others identified by model number and Amazon Standard Identification Number (ASIN). (Compl. ¶¶ 11, 13, 16).

Functionality and Market Context

• The complaint alleges that the accused devices are multimedia projectors. (Compl. ¶ 2). It does not describe the specific functionality of their image adjustment features, but instead asserts a negative limitation: that the projectors do not perform a key step required by the patent's claims. (Compl. ¶ 44). The complaint asserts that Optoma is a "market leader" and the "world's leading 4K UHD projector and DLP® brand," suggesting the commercial importance of the accused products. (Compl. ¶ 1).

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement. The following table summarizes the Plaintiffs' central non-infringement argument against Maxell's reported allegations, focusing on the key disputed limitation.

U.S. Patent No. 8,075,142 Non-Infringement Allegations

No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Scope Questions: The central dispute appears to be the meaning of the phrase "projecting a portion selectively fitted to the display portion." The analysis may question whether this language requires the specific embodiment described in the patent—selecting a sub-image from a physically larger display element—or if it could be interpreted more broadly to read on other digital image adjustment technologies.
  • Technical Questions: A primary factual question will be how the accused Optoma projectors technically perform image adjustment. The complaint's assertion that they "do not project 'a portion of an image selectively fitted to' the screen" suggests a fundamental operational mismatch with the claimed invention, but the complaint does not provide technical details on how the accused products operate. (Compl. ¶ 44).

V. Key Claim Terms for Construction

• The Term: "projecting a portion selectively fitted to the display portion"
• Context and Importance: This term appears to be the crux of the non-infringement dispute. Its construction will determine whether the accused projectors' method of image adjustment falls within the scope of the claim. Practitioners may focus on this term because Plaintiffs' non-infringement argument is based entirely on the accused products allegedly not meeting this limitation. (Compl. ¶¶ 43-44).
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party arguing for a broader scope might point to the general functional language used in the claim, suggesting that any system with a "display controller portion" that adjusts an image to fit a screen could be covered, regardless of the specific mechanism.
  • Evidence for a Narrower Interpretation: Plaintiffs may argue for a narrower interpretation tied to the patent’s detailed description. The specification repeatedly explains the concept by reference to an "original image" ('P') that is larger than the "actual image" ('P') projected on the screen. (’142 Patent, col. 5:16-24). The patent also describes a specific embodiment where a wide-aspect-ratio (16:9) display panel is used to project a movable standard-aspect-ratio (4:3) image, which strongly supports an interpretation requiring an oversized image source from which a portion is selected. (’142 Patent, col. 13:40-55).

VI. Other Allegations

The complaint does not contain allegations of indirect or willful infringement in the conventional sense, as it is a declaratory judgment action filed by the accused infringers. Therefore, this section is omitted.

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

The resolution of this declaratory judgment action may depend on the answers to several key questions:

• A threshold issue will be one of corporate law and standing: Did the October 2021 nunc pro tunc assignment validly transfer ownership of the ’142 Patent to the current Maxell entity after the original patent-holding entity was dissolved? An invalid assignment could render Maxell unable to enforce the patent.
• The central technical issue will be one of definitional scope: Will the claim term "projecting a portion selectively fitted to the display portion" be construed narrowly to require the specific oversized-display-element architecture described in the patent's specification, or can it be read more broadly to cover the image adjustment technology used in the accused Optoma projectors?
• A key evidentiary question will be one of invalidity based on prior art: Can Plaintiffs prove with clear and convincing evidence that the Optoma HD72 or Hitachi CP-A100 projectors were publicly sold or offered for sale before the patent's March 10, 2008 priority date and that they practice all elements of the asserted claims?