PTAB

IPR2025-01241

3D Systems Corp v. Intrepid Automation Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multiple image projection system for additive manufacturing
  • Brief Description: The ’301 patent discloses an additive manufacturing system using a plurality of image projectors to form a composite image for curing a photoactive resin. The system employs a "stack of filters" to improve print resolution, including normalizing irradiance, gamma adjustment, warp correction, and edge blending.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are Anticipated by Shkolnik

  • Prior Art Relied Upon: Shkolnik (Patent 8,666,142).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shkolnik, which predates the ’301 patent, discloses every limitation of the challenged claims. Shkolnik taught a multi-projector ("multiple pattern generators") additive manufacturing system that projects overlapping sub-images to form a composite image on a resin pool. Petitioner asserted Shkolnik disclosed all four claimed filtering techniques: (1) normalizing irradiance through "intensity compensation" to adjust sub-image irradiance to an "ideal" or "standard" level; (2) gamma adjustment by mapping pixel intensity values (e.g., 0-255) based on resin reactivity to achieve a desired cure depth and create smooth surfaces; (3) warp correction using "pattern correction methods" and "calibration patterns" to correct for geometric distortions like pincushioning; and (4) edge blending by adjusting pixel intensity in overlapping regions to avoid overexposure, for which it teaches a linear interpolation algorithm.

Ground 2: Claims 1-20 are Obvious over Sekine and Greene

  • Prior Art Relied Upon: Sekine (WO 2017/154564), Greene (Application # 2017/0102679).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Sekine taught a multi-projector additive manufacturing system with overlapping sub-images and disclosed three of the four claimed correction techniques. Specifically, Sekine taught irradiance normalization ("illuminance correction control"), geometric/warp correction ("displacement correction control"), and edge blending via "grayscaling" in overlap regions. The petition argued that the fourth technique, the gamma adjustment mask, was explicitly taught by Greene. Greene, directed to improving 3D printing smoothness, taught a "gamma correction" process that adjusts grayscale pixel intensity levels based on the "nonlinear characteristic of the photoactive resin" specifically to "smooth out edges."
    • Motivation to Combine: A POSITA would combine Greene’s well-known gamma correction technique with Sekine’s multi-projector system to solve the known problem of aliasing and improve surface smoothness. Both references are in the same field of light-based 3D printing and address improving precision and accuracy.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because applying a known smoothing technique (Greene's gamma correction) to a known multi-projector system (Sekine) to improve a known issue (surface roughness) would yield the predictable result of improved print quality.

Ground 3: Claims 1-20 are Obvious over Shkolnik and Sekine

  • Prior Art Relied Upon: Shkolnik (Patent 8,666,142), Sekine (WO 2017/154564).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shkolnik provides the foundational system disclosing nearly all limitations, including all four filtering techniques. Sekine was presented as providing additional detail and motivation for specific features, particularly the irradiance mask. While Shkolnik taught "intensity compensation," Sekine further detailed an "illuminance correction control" method for making illumination distribution "uniform" across adjacent projection images. This teaching from Sekine reinforced and provided an alternative embodiment for the irradiance normalization taught by Shkolnik.
    • Motivation to Combine: A POSITA would combine the teachings of Shkolnik and Sekine, both in the field of multi-projector 3D printing, to optimize system performance. Sekine's detailed approach to normalizing irradiance would be a logical and known technique to apply to Shkolnik’s system to enhance the uniformity of the composite projected image.
    • Expectation of Success: A POSITA would expect that incorporating Sekine's specific irradiance control methods into Shkolnik's comprehensive system would predictably improve the uniformity of light exposure, a known parameter for improving print consistency and accuracy.

4. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-20 of Patent 11,014,301 as unpatentable.