PTAB

IPR2020-01089

Align Technology Inc v. 3Shape AS

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Intraoral Scanner for Providing Data for 3D Geometry
  • Brief Description: The ’042 patent describes an apparatus and method for optical 3D scanning, particularly suited for intraoral scanning of teeth. The system uses a focus scanner that projects a predetermined illumination pattern onto an object and evaluates a correlation measure of the detected pattern to determine in-focus positions and generate 3D coordinates.

3. Grounds for Unpatentability

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

  • Prior Art Relied Upon: Babayoff (Application # 2005/0283065) and Sussman (Patent 6,148,120).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Babayoff taught a complete 3D confocal intraoral scanner that determined surface geometry and color by capturing images while moving a focus plane. Babayoff’s scanner illuminated an object with a 2D array of spots and identified in-focus positions by detecting maximum light intensity. While Babayoff disclosed that its system "typically" operated in a telecentric mode to maintain constant magnification, Petitioner contended that the claims, particularly independent claims 1, 17, 19, and 21, were directed to a non-telecentric lens arrangement. Sussman was cited for its teaching of a computational solution (image-warping) to correct for magnification distortions that inherently arise in conventional, non-telecentric 3D scanning systems. Petitioner asserted that combining Sussman’s computational correction with Babayoff’s scanner would result in the claimed non-telecentric intraoral scanner.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Babayoff and Sussman to create a more practical and less expensive scanner. Sussman explicitly taught that its computational approach "eliminates the need for telecentric optics," which it described as costly, imposing system limitations, and introducing drawbacks like vignetting. A POSA would therefore have been motivated to modify Babayoff’s scanner to use a simpler, conventional non-telecentric optical system and apply Sussman’s computational correction to achieve the desired 3D scanning functionality without the costs and constraints of a telecentric design.
    • Expectation of Success: A POSA would have a reasonable expectation of success. The use of conventional non-telecentric lens systems for depth-from-focus imaging was well-known, as evidenced by Sussman. Babayoff’s own disclosure suggested that its confocal imaging arrangement was not exclusively telecentric. Therefore, modifying Babayoff’s scanner to operate in a non-telecentric mode while using Sussman's established correction techniques would involve applying known principles to achieve a predictable result: a functional 3D intraoral scanner.

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

  • Prior Art Relied Upon: Babayoff (Application # 2005/0283065), Sussman (Patent 6,148,120), and Bayer (Patent 3,971,065).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Babayoff and Sussman from Ground 1 to further address dependent claims 4, 5, and 9, which recite a "color filter array," specifically a "Bayer filter array," comprising at least three types of color filters. Petitioner argued that while Babayoff taught a color image sensor (e.g., a color CCD), Bayer taught the specific and conventional implementation of such a sensor using a "Bayer filter array." Bayer’s filter array, with its intermixed red, green, and blue filter elements, could be superposed on a sensor array to enable color imaging at a single imaging site.
    • Motivation to Combine: A POSA seeking to implement the color image sensor taught in Babayoff would have been motivated to use a well-known, efficient, and conventional method to do so. The Bayer filter array was a standard approach that allowed for simultaneous color imaging on a single sensor, thereby avoiding the "optical complexity and problems with image registration" associated with other methods. This provided a clear motivation to incorporate Bayer’s teaching into the non-telecentric scanner established by the combination of Babayoff and Sussman.
    • Expectation of Success: A POSA would have a high expectation of success, as using a Bayer filter was a conventional and well-understood technique for creating a color image sensor at the time of the invention. Its application to the sensor in Babayoff’s system was a straightforward implementation of a known technology for its intended purpose.

4. Key Claim Construction Positions

  • "focus plane": Petitioner adopted the patent’s definition: a surface where light rays emitted from a pattern converge to form an image on the object being scanned. Petitioner also applied the Patent Owner’s litigation position that an array of spots, as taught by Babayoff, constitutes a "pattern" under this definition.
  • "image measure": Petitioner noted that in related litigation, this term was recommended to be found indefinite. However, for the purposes of the IPR, Petitioner adopted the Patent Owner’s broad interpretation that the term is not limited to the "correlation measure" in the specification and includes any measure of the image, such as the "light intensity" taught by Babayoff. This construction was critical to mapping Babayoff onto claims 6-8.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv was unwarranted. The ’042 patent was added to the parallel district court litigation late, and the IPR petition was filed in a timely manner less than ten months later. Petitioner contended that the district court trial date was speculative, particularly due to uncertainties from the COVID-19 pandemic, and that the parties and the court had not yet invested significant resources in resolving the specific invalidity contentions presented in the petition. Furthermore, Petitioner argued that the grounds raised new issues of unpatentability, as the combination of Babayoff and Sussman was never considered during prosecution.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-22 of the ’042 patent as unpatentable under 35 U.S.C. §103.