PTAB

IPR2025-01242

3D Systems Corp v. Intrepid Automation Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multiple Image Projection Method for Additive Manufacturing
  • Brief Description: The ’511 patent discloses a method for additive manufacturing using multiple image projectors to form a composite image on a resin pool. The method claims to improve printing resolution by using a set of four digital filters: an irradiance mask, a gamma adjustment mask, a warp correction filter, and an edge blending bar.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-8 and 14-15 by Shkolnik

  • Prior Art Relied Upon: Shkolnik (Patent 8,666,142).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shkolnik, which teaches a system for increasing accuracy in 3D manufacturing with multiple "pattern generators" (projectors), discloses every limitation of the challenged claims. Petitioner asserted that Shkolnik teaches projecting overlapping sub-images onto a reactive material from multiple projectors. The four key filter limitations were allegedly met as follows: (1) Shkolnik’s "correction map" for adjusting "intensity compensation" constitutes the claimed "irradiance mask"; (2) its disclosure of adjusting intensity and exposure time based on the specific resin's properties is the claimed "gamma adjustment"; (3) its method for correcting geometric distortions like pincushioning is the claimed "warp correction"; and (4) its technique for adjusting pixels in overlap regions to prevent overexposure is the claimed "edge blending."
    • Key Aspects: Petitioner emphasized that Shkolnik teaches all four of the allegedly novel filter techniques in a single, integrated system for the same purpose as the ’511 patent.

Ground 2: Obviousness of Claims 1-8, 14, and 15 over Sekine in view of Greene

  • Prior Art Relied Upon: Sekine (WO 2017/154564) and Greene (Application # 2017/0102679).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Sekine teaches a multi-projector additive manufacturing system that discloses three of the four claimed filter types. Specifically, Sekine’s "illuminance correction control" was argued to teach the irradiance mask, its "displacement correction control" teaches warp correction, and its use of grayscaling at sub-image boundaries teaches edge blending. Petitioner asserted that Greene, which is directed to sub-pixel grayscale 3D printing, supplies the fourth element: a "gamma correction" process that adjusts grayscale intensity levels based on the "nonlinear characteristic of the photoactive resin."
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine the teachings of Sekine and Greene to improve the functionality of Sekine's system. Because both references address improving precision and accuracy in DLP 3D printing, a POSITA would have found it obvious to incorporate Greene's known gamma correction technique to enhance the surface smoothness and accuracy of parts printed with Sekine's multi-projector system.
    • Expectation of Success: The combination would predictably result in improved print quality, as it involved applying a known technique (gamma adjustment) to a known system (a multi-projector 3D printer) to achieve its expected function.

Ground 3: Obviousness of Claims 9-12 over Sekine and Greene in further view of Jørgensen

  • Prior Art Relied Upon: Sekine (WO 2017/154564), Greene (Application # 2017/0102679), and Jørgensen (EP 3,053,729).

  • Core Argument for this Ground:

    • Prior Art Mapping: Building upon the combination of Sekine and Greene from Ground 2, Petitioner argued that Jørgensen teaches the limitations of dependent claims 9-12 related to moving the sub-images during layer exposure. Jørgensen discloses DLP-based additive manufacturing systems designed for larger building areas, which explicitly teach dividing a large image into sub-images and moving the projectors during exposure. Petitioner asserted Jørgensen teaches both "step and flash" (step-expose-step) and continuous movement (claim 10), as well as arranging projectors in a 1D array for movement in a perpendicular direction (claim 11).
    • Motivation to Combine: Petitioner argued that a POSITA, seeking to improve the build speed and size capabilities of the system described by Sekine and Greene, would logically turn to known methods for moving projector arrays, such as those taught by Jørgensen. This combination would have been a predictable implementation for scaling up the printing process.
    • Expectation of Success: Combining these known techniques for their intended purposes—Sekine for multi-projector coordination, Greene for resin-specific accuracy, and Jørgensen for large-area scanning—would have yielded the predictable result of a larger, more efficient, and accurate 3D printing system.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 1-8, 14, and 15 are obvious over Shkolnik and Sekine, and that claim 13 is obvious over Sekine, Greene, and Jørgensen in further view of Yi (a 2017 journal article teaching sub-image movement in a third direction).

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should not discretionarily deny the petition because the primary prior art references (Shkolnik, Sekine, Jørgensen, and Yi) were not considered during prosecution of the ’511 patent. Petitioner further contended the grounds are compelling, the petition was filed expeditiously, and a trial date has not yet been set in the parallel district court litigation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-15 of the ’511 patent as unpatentable.