PTAB

IPR2018-00196

Align Technology Inc v. 3Shape AS

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Detecting a Movable Object
  • Brief Description: The ’551 patent discloses a method for improving 3D intraoral scanning by detecting and disregarding movable objects, such as a patient's tongue or a dentist's instrument. The method involves taking at least two 3D scans, defining "excluded volumes" based on these scans, and disregarding surface data that falls within an opposing scan's excluded volume to create a clean virtual 3D model of a rigid object like teeth.

3. Grounds for Unpatentability

Ground 1: Obviousness over Bernardini - Claims 1, 6-8, 11-13, 15, 16, and 20-25 are obvious over Bernardini.

  • Prior Art Relied Upon: Bernardini (Patent 6,750,873)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Bernardini taught all limitations of the independent claims. Bernardini described a method for creating an accurate 3D model from multiple scans by detecting and removing "outliers" and occlusions. Petitioner contended that Bernardini's process of using a depth map from one scan (e.g., a z-buffer) to identify and discard occluded portions of another scan was functionally identical to the ’551 patent’s method of defining an "excluded volume" and disregarding data within it. Both systems take multiple 3D representations and use data from one scan to filter out erroneous data from another, achieving the same result of a cleaned-up 3D model.
    • Motivation to Combine (for §103 grounds): This ground was asserted as obviousness over a single reference, arguing that Bernardini alone rendered the claims obvious because its teachings on outlier removal directly mapped to the claimed invention.
    • Expectation of Success (for §103 grounds): Applying Bernardini's established method for removing occlusions would predictably result in a cleaner 3D model, achieving the stated goal of the ’551 patent.

Ground 2: Dental Application - Claims 2-5, 18, and 19 are obvious over Bernardini in view of Rubbert.

  • Prior Art Relied Upon: Bernardini (Patent 6,750,873) and Rubbert (Patent 7,471,821).
  • Core Argument for this Ground:
    • Prior Art Mapping: While Bernardini provided the foundational method for 3D model creation and outlier removal, Rubbert explicitly applied these concepts to the dental field. Rubbert taught a hand-held scanner for capturing 3D information of a patient's dentition and surrounding anatomical structures. It specifically identified movable objects to be excluded, such as soft tissue (gums, cheek, tongue), dental instruments, and a dentist's finger, which directly correspond to the limitations in dependent claims 2-5, 18, and 19.
    • Motivation to Combine (for §103 grounds): A person of ordinary skill in the art (POSITA) would combine Bernardini's general algorithm for cleaning 3D scan data with Rubbert's specific application in intraoral scanning. The motivation was to apply a known, effective method for outlier removal (Bernardini) to the specific, known problem of handling obstructions in dental scanning (Rubbert) to create a more robust and accurate intraoral scanning system.
    • Expectation of Success (for §103 grounds): The combination would predictably yield a system capable of creating an accurate 3D model of teeth while disregarding common intraoral obstructions, as it involved applying known techniques to their intended field of use.

Ground 3: Focusing Optics - Claims 9 and 10 are obvious over Bernardini in view of Theil.

  • Prior Art Relied Upon: Bernardini (Patent 6,750,873) and Theil (Application # 2009/0279103).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground augmented Bernardini's base method with the teachings of Theil to address claims 9 and 10, which recited a "scan volume" defined by "focusing optics." Theil disclosed an apparatus for optical 3D measurement that used focusing optics (an objective) to focus a light beam onto the surface of the object, ensuring the surface is "imaged sharply." This directly taught the limitations of using focusing optics to define the scan volume.
    • Motivation to Combine (for §103 grounds): A POSITA would combine the references to improve the performance of Bernardini's system. It was known that using focusing optics, as taught by Theil, improved the quality and sharpness of 3D scan data. A POSITA would have been motivated to incorporate this known technology into Bernardini's 3D modeling system to achieve more accurate and predictable results.
    • Expectation of Success (for §103 grounds): Incorporating focusing optics into a 3D scanner was a well-understood technique for improving image quality. A POSITA would have had a high expectation of success in achieving a sharper, more robust scanning system through this combination.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combining Bernardini with Newcombe (Application # 2012/0195471) for its teaching of distance-based thresholding (claim 14) and with Bodony (Application # 2012/0141949) for its teaching of real-time, concurrent updating of the 3D model (claim 17). These grounds relied on similar rationales of combining Bernardini's core process with known techniques to add specific functionalities.

4. Key Claim Construction Positions

  • "movable object": Petitioner proposed this term meant "an object that occurs in a scanning volume between a scanner and a scan target and that is separate from the scan target object." This construction was central to arguing that the "outliers" and "occlusions" described in the prior art, which were separate from the main object being scanned, were the same as the claimed "movable object."
  • "excluded volume": Petitioner proposed this term meant "a scan volume, or a sub-volume of the scan volume, where no surface of the scan object is present." This construction was critical for equating the claimed "excluded volume" with the prior art's concept of a z-buffer or a view frustum from a given camera position, which by definition contains no surface data from the target object beyond the initial scan.

5. Arguments Regarding Discretionary Denial

  • Petitioner disclosed a concurrently filed IPR petition (IPR2018-00195) against the same patent, which relied on different primary prior art (McQueston). Petitioner argued that both petitions should be instituted because they presented distinct invalidity theories and relied on references that provided stronger disclosures for different claim elements. For example, this petition's primary reference, Bernardini, taught an excluded volume by comparing depth maps, whereas the co-pending petition's primary reference taught a volumetric measurement for each voxel.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-25 of the ’551 patent as unpatentable.