PTAB

IPR2023-00387

Dental Imaging Technologies Corp v. 3Shape AS

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Focus Scanning Apparatus
  • Brief Description: The ’146 patent relates to an intraoral scanner for determining the 3D geometry and color of objects, such as teeth. The scanner uses a time-varying illumination pattern projected onto an object and captures images at different focal planes to determine 3D surface information.

3. Grounds for Unpatentability

Ground 1: Claims 21, 23-27, and 29 are obvious over Babayoff, Zhang, and Knighton.

  • Prior Art Relied Upon: Babayoff (Application # 2008/0024768), Zhang (an ACM SIGGRAPH 2006 article), and Knighton (Application # 2005/0237581).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Babayoff taught a handheld intraoral scanner that determines 3D geometry and color using a camera defocus method (analyzing images from varied focal planes) with a static illumination pattern. Zhang taught an alternative and superior projection defocus method, which determines 3D shape by shifting a time-varying illumination pattern (e.g., stripes from a DLP projector) across an object. Knighton taught a handheld scanner that performs local processing of 3D data and wirelessly transmits the processed geometry. Petitioner asserted that the combination replaces Babayoff’s camera defocus method with Zhang’s superior projection defocus method and adds Knighton’s local processing and wireless communication capabilities.
    • Motivation to Combine: A POSITA would combine Babayoff with Zhang to replace an inferior 3D imaging method with a known, superior alternative that was more accurate, computationally simpler, and independent of scene geometry. A POSITA would incorporate Knighton's teachings to make Babayoff's handheld scanner wireless, improving its maneuverability and usability, and to add local processing to reduce the amount of data requiring transmission.
    • Expectation of Success: Success was expected because the combination involved substituting one known 3D imaging technique for another known, superior one and adding known features (local processing, wireless transmission) to achieve their predictable benefits.

Ground 2: Claims 1, 3-6, 8-13, 15, 20, and 22 are obvious over Babayoff, Zhang, Knighton, and Hanson.

  • Prior Art Relied Upon: Babayoff (Application # 2008/0024768), Zhang (an ACM SIGGRAPH 2006 article), Knighton (Application # 2005/0237581), and Hanson (Application # 2003/0043089).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds upon the combination in Ground 1, adding Hanson to address the "high-speed camera" limitation found in claims 1 and 22. Petitioner asserted that while Babayoff taught the desirability of a high-speed camera for rapid acquisition, Hanson explicitly disclosed a CMOS image sensor architecture with multiple analog-to-digital (A/D) converters per line of pixels specifically to "increase the speed of the image sensor." This structure directly met the patent's definition of a high-speed camera. The remaining claim limitations were mapped to the combination of Babayoff, Zhang, and Knighton as detailed in Ground 1.
    • Motivation to Combine: The motivation to combine Babayoff, Zhang, and Knighton remained the same. A POSITA would be motivated to further add Hanson’s high-speed sensor design because Babayoff already established the need for rapid image capture. Hanson provided a known method for achieving this speed increase in a CMOS sensor, which Knighton identified as a known alternative to the CCD sensor used in Babayoff.
    • Expectation of Success: A POSITA would have expected success in integrating Hanson's design, as it was a straightforward implementation of a known component to achieve a desired and predictable improvement in performance (faster image capture).

Ground 3: Claim 2 is obvious over Babayoff, Zhang, Knighton, Hanson, and Gandyra.

  • Prior Art Relied Upon: Babayoff (Application # 2008/0024768), Zhang (an ACM SIGGRAPH 2006 article), Knighton (Application # 2005/0237581), Hanson (Application # 2003/0043089), and Gandyra (Application # 2009/0087050).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the four-way combination from Ground 2 to challenge dependent claim 2, which requires the pattern generator to include "at least one translucent and/or transparent pattern element." While the primary combination relied on Zhang's DLP projector, Gandyra was introduced because it taught an intraoral scanner that could produce a time-varying pattern using either a DLP projector or, alternatively, a "pattern transparency," which constitutes a transparent pattern element.
    • Motivation to Combine: A POSITA would be motivated to modify the projector-based system taught by Zhang with the transparent pattern element from Gandyra because Gandyra expressly taught it as a known alternative in the specific context of intraoral scanning. This modification might be chosen for reasons such as design simplicity or potential cost savings.
    • Expectation of Success: The combination would have yielded predictable results, as it involved substituting one known pattern generation technique (projector) with a known alternative (transparency) for the exact same purpose in the same field of technology.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under both §314(a) and §325(d).
  • To preclude denial under §314(a) and the Fintiv factors, Petitioner provided a Sotera-type stipulation, agreeing not to pursue in parallel district court litigation any invalidity ground that was raised or could have been reasonably raised in an instituted inter partes review (IPR).
  • Petitioner argued that denial under §325(d) was unwarranted because the ’146 patent had not been previously challenged at the PTAB, and the specific prior art references and combinations asserted in the petition were not considered by the examiner during the original prosecution.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-6, 8-13, 15, 20-27, and 29 of the ’146 patent as unpatentable.