Coretronic Corp v. Maxell Ltd

1. Case Identification

• Case #: IPR2025-00477
• Patent #: 7,850,313
• Filed: January 17, 2025
• Petitioner(s): Coretronic Corporation, Optoma Corporation
• Patent Owner(s): Maxell, Ltd.
• Challenged Claims: 1-3

2. Patent Overview

• Title: Projection Type Image Apparatus
• Brief Description: The ’313 patent describes a projection apparatus for obliquely projecting an image onto a screen. The apparatus includes an image display element, a first and second lens group, a reflection mirror, first and second mounting bases for the respective lens groups, and a chassis to store these components.

3. Grounds for Unpatentability

Ground 1: Obviousness over Yamagishi ’723, Itohiya ’986, and Itohiya ’759 - Claims 1 and 3 are obvious over Yamagishi ’723 in view of Itohiya ’986 and Itohiya ’759.

• Prior Art Relied Upon: Yamagishi ’723 (Application # 2006/0132723), Itohiya ’986 (Japanese Publication No. 2006-47986), and Itohiya ’759 (Application # 2005/0275759).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Yamagishi ’723, a rear projector system, discloses most elements of claim 1, including an image display element, first and second lens groups, a reflection mirror for oblique projection, and a chassis (housing). However, Yamagishi ’723 does not explicitly teach separate fixed and movable mounting bases for the lens groups. Itohiya ’986 was introduced to teach a lens system with both fixed lenses (on a first mounting base) and movable lenses (on a second mounting base) to allow for precise focusing. Itohiya ’759 was used to supply details for firmly fixing the first mounting base to the bottom of the chassis. For claim 3, Petitioner asserted that the "adjustment fixing screw" in Itohiya ’986 is a rod member that makes the second mounting base movable.
  • Motivation to Combine: A POSITA would combine these references as they are all in the same field of optical projectors. A POSITA would modify Yamagishi ’723 with the adjustable lens system of Itohiya ’986 to gain the known benefits of precise focusing and magnification. Because Itohiya ’986 and Itohiya ’759 share the same inventor, a POSITA would naturally look to Itohiya ’759 for implementation details on mounting fixed lens groups within a chassis.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because combining known mounting and adjustment mechanisms with a known projector configuration would yield predictable results.

Ground 2: Obviousness over Itohiya ’759 and Itohiya ’986 - Claims 1 and 3 are obvious over Itohiya ’759 in view of Itohiya ’986.

• Prior Art Relied Upon: Itohiya ’759 (Application # 2005/0275759) and Itohiya ’986 (Japanese Publication No. 2006-47986).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Itohiya ’759 serves as the primary reference, disclosing a rear-projection apparatus with an image display element, first and second lens groups, a reflection mirror for oblique projection, and a chassis. Itohiya ’759 also discloses a fixed first mounting base (lens barrel) secured to the chassis. Petitioner argued that while Itohiya ’759 suggests some lenses are movable for focusing, it does not explicitly show the mounting base itself is movable. Itohiya ’986 was introduced to provide a detailed mechanism for a movable second mounting base (sliding lens frame) to support adjustable lenses. For claim 3, the "adjustment fixing screw" of Itohiya ’986 was argued to be the claimed "rod member."
  • Motivation to Combine: A POSITA would combine the teachings because both references address rear-projection systems and share the same inventor, making it natural to look to one for implementation details for the other. A POSITA would incorporate the adjustment mechanism from Itohiya ’986 into the system of Itohiya ’759 to achieve the well-understood benefits of precise lens adjustment.
  • Expectation of Success: The combination involved applying a known lens adjustment mechanism to a conventional projector system, which was argued to be a predictable design choice for a POSITA.

Ground 3: Obviousness over Karasawa, Yamagishi ’706, and Itohiya ’759 - Claim 1 is obvious over Karasawa in view of Yamagishi ’706 and Itohiya ’759.

• Prior Art Relied Upon: Karasawa (Japanese Publication No. 2003-248169), Yamagishi ’706 (Application # 2005/0219706), and Itohiya ’759 (Application # 2005/0275759).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Karasawa discloses a projector with the claimed optical elements: an image display, multiple lens groups, and a reflective mirror for oblique projection within a cabinet (chassis). Karasawa further discloses that some of its lenses are movable. However, it does not explicitly teach distinct mounting bases for fixed and movable lens groups. Yamagishi ’706 was introduced to teach a projector system where some lenses (focusing lenses) move while others are fixed. Itohiya ’759 was then used to supply the teaching of firmly securing the fixed lens group's mounting base to the bottom of the chassis.
  • Motivation to Combine: A POSITA would be motivated to combine these references to create an improved projector. Recognizing Karasawa's disclosure of movable lenses, a POSITA would look to a reference like Yamagishi ’706 for a more cost-effective and reliable design where only specific focusing lenses move. A POSITA would then consult Itohiya ’759 for known methods of mounting the fixed lens components within the projector's chassis.
  • Expectation of Success: The proposed combination was presented as a straightforward integration of known features from the same technical field, leading to predictable results without requiring undue experimentation.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on the combinations above further in view of Ohzawa (Patent 6,542,204) to teach the inclined optical axis of claim 2, and Karasawa in view of Yamagishi ’706, Itohiya ’759, and Itohiya '986 for claim 3.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §325(d), stating that the prior art references and arguments presented in the petition were not previously considered by the USPTO during prosecution of the ’313 patent.
• Petitioner also argued that discretionary denial under Fintiv is not warranted. The parallel district court case is in its early stages, with a trial date that could easily occur after the Board’s Final Written Decision (FWD). Petitioner further stipulated that, if IPR is instituted, it will not pursue the same grounds or prior art in the district court litigation.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-3 of the ’313 patent as unpatentable.