PTAB

IPR2020-01088

Align Technology Inc v. 3Shape AS

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Optical 3D Scanning
  • Brief Description: The ’042 patent relates to an apparatus and method for optical 3D scanning, particularly suited for intraoral applications. The disclosed technology is a focus scanner that generates a probe light with a predetermined spatial pattern and evaluates a correlation measure of the detected pattern to determine in-focus positions, which are then transformed into 3D coordinates.

3. Grounds for Unpatentability

Ground 1: Obviousness over Berner and Babayoff - Claims 1-3, 6-8, and 10-22 are obvious over Berner in view of Babayoff.

  • Prior Art Relied Upon: Berner (Application # 2010/008536) and Babayoff (Application # 2005/0283065).
  • Core Argument for this Ground: Petitioner argued that Berner discloses a compact intraoral scanner with a non-telecentric lens arrangement for determining 3D geometry but does not detail the specific scanning methodology. Babayoff, which Berner references as known prior art, teaches the exact confocal scanning and color imaging techniques needed to make Berner’s system fully functional. The combination renders the challenged claims obvious.
    • Prior Art Mapping: Petitioner asserted Berner teaches the core components of an intraoral scanner, including a non-telecentric optical system that shifts a focus plane to scan an object. This non-telecentric arrangement inherently results in non-parallel and diverging chief rays, which Petitioner argued meets the limitations of independent claims 1, 17, 19, and 21. Babayoff was argued to supply the well-known method for processing the scan data, specifically by determining in-focus positions based on measuring maximum light intensity from a series of 2D images. Babayoff also taught the inclusion of a color image sensor and white light source to capture color data, satisfying limitations in dependent claims.
    • Motivation to Combine: A POSITA would combine Babayoff's established confocal scanning method with Berner's scanner because Berner’s stated goal was to create a more compact device while retaining high-quality confocal scanning capabilities, which Babayoff provided. Further, a POSITA would be motivated to add Babayoff’s color imaging capabilities to improve dental prosthesis shading and fit, and to aid in stitching 3D data sets, yielding predictably better results.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Berner's system already incorporated the necessary functional components (e.g., light source, sensor, means for adjusting focus) to implement Babayoff's scanning method. Integrating color sensing was also a routine and well-understood practice, with Babayoff providing multiple ways to do so without interfering with the 3D scanning process.

Ground 2: Obviousness over Berner, Babayoff, and Bayer - Claims 4-5 and 9 are obvious over Berner, Babayoff, and Bayer.

  • Prior Art Relied Upon: Berner (Application # 2010/008536), Babayoff (Application # 2005/0283065), and Bayer (Patent 3,971,065).
  • Core Argument for this Ground: This ground builds upon Ground 1, arguing that implementing the color image sensor using a conventional "Bayer filter array," as recited in dependent claims 4, 5, and 9, would have been an obvious design choice.
    • Prior Art Mapping: Petitioner argued that Bayer explicitly teaches a color filter array, known as a "Bayer filter array," comprising at least three types of color filters (e.g., red, green, blue). This filter array is designed to be superposed on a solid-state image sensor (like a CCD) to enable color imaging. This directly mapped to the limitations requiring a color filter array and specifically a Bayer filter array.
    • Motivation to Combine: A POSITA building the scanner from Ground 1 would be motivated to use the Bayer filter array because it was a well-known, conventional method that enabled efficient color imaging to occur at a single imaging site. This approach would avoid the optical complexity and image registration problems associated with other color capture methods.
    • Expectation of Success: A POSITA would have a reasonable expectation of success as the use of a Bayer filter was a conventional and widely adopted technique for digital color imaging at the time. Its application to the image sensor in the combined Berner/Babayoff system was a straightforward implementation of a known component for its intended purpose.

4. Key Claim Construction Positions

  • "focus plane": Petitioner noted the patent’s definition and, for the purpose of the petition, adopted the Patent Owner's litigation position that an array of spots constitutes a "pattern" used to form an image on the object at the focus plane.
  • "image measure": Petitioner highlighted that this term, recited in dependent claims, was found indefinite in related district court litigation. For the IPR, Petitioner adopted the Patent Owner’s broad litigation position that the term is not limited to the "correlation measure" described in the specification and can encompass any measure of an image, such as light intensity.

5. Key Technical Contentions (Beyond Claim Construction)

  • Lack of Written Description and Priority Date: A central contention was that the issued claims lack written description in the pre-AIA priority applications. Petitioner argued that claim terms like "first and second propagation axis" and "first and second divergence angle" were newly introduced during prosecution and are not described in the specification. Because these new limitations are essential to the claims, the claims are not entitled to a pre-AIA filing date and are therefore subject to prior art under the AIA, such as Berner.

6. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under Fintiv. The core reasons were: (1) the petition was filed diligently, less than ten months after the ’042 patent was first asserted in the parallel litigation; (2) the district court trial date was speculative and likely to be delayed due to the late addition of the patent and the COVID-19 pandemic; (3) there had been minimal investment by the court and parties on the ’042 patent issues in the district court case; and (4) Petitioner agreed not to pursue any instituted IPR ground in the parallel district court action to avoid overlap.

7. Relief Requested

  • Petitioner requests institution of inter partes review and cancellation of claims 1-22 of the ’042 patent as unpatentable.