Align Technology Inc v. 3Shape AS

1. Case Identification

• Case #: IPR2019-00118
• Patent #: 9,962,244
• Filed: November 5, 2018
• Petitioner(s): Align Technology, Inc.
• Patent Owner(s): 3Shape As
• Challenged Claims: 31-32, 34

2. Patent Overview

• Title: Focus Scanner for Recording Surface Geometry and Surface Color
• Brief Description: The ’244 patent discloses a three-dimensional (3D) focus scanner system, particularly for dental applications, that records both surface geometry and surface color. The system captures a series of 2D images at different focal planes to generate a digital 3D representation of an object.

3. Grounds for Unpatentability

Ground 1: Claims 31 and 32 are obvious over Fisker in view of Tanaka

• Prior Art Relied Upon: Fisker (Application # 2012/0092461) and Tanaka (Application # 2015/0029367).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Fisker taught a focus scanning apparatus for recording 3D geometry and color that met nearly all limitations of claim 31. This included a multichromatic light source, a color image sensor capturing a stack of 2D images by translating a focus plane, and a data processing system to derive geometry and color information. Petitioner contended the only limitation Fisker did not explicitly teach was a color filter array where the proportion of pixels for a selected wavelength is larger than 50%. Tanaka allegedly supplied this missing element by disclosing a color filter array with a 6x6 pixel pattern where green filters, which contribute most to luminance signals, comprise more than 50% (20 of 36) of the filters. For claim 32, Petitioner argued Tanaka also taught the specific 6x6 cell filter arrangement recited in the claim.
  • Motivation to Combine: A POSITA would combine Fisker and Tanaka to improve the image quality and spatial resolution of Fisker’s scanner. Tanaka’s filter scheme was presented as a known improvement over standard Bayer filters (which Fisker suggests) for suppressing false color and improving resolution.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because incorporating Tanaka’s known light filtering technique into Fisker’s imaging apparatus would be a routine modification to achieve a more accurate and clear image.

Ground 2 & 3: Claim 34 is obvious over Fisker in view of Suzuki or Cai

• Prior Art Relied Upon: Fisker (Application # 2012/0092461), Suzuki (Application # 2013/0070128), and Cai (Application # 2010/0067789).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Fisker taught most limitations of claim 34, including deriving geometry and color by calculating a correlation measure between image portions and a weight function and identifying the maximum correlation value. The key limitation Fisker allegedly did not teach was "computing an averaged sub-scan color for a number of points...comprising an averaging of sub-scan colors of surrounding points." Petitioner argued this was a well-known technique for improving image quality. Suzuki allegedly disclosed correcting defective pixel values based on a weighted average of surrounding pixel values. Similarly, Cai allegedly disclosed obtaining an interpolated color value from adjacent real pixel values of the same color.
  • Motivation to Combine: A POSITA would combine Fisker with Suzuki or Cai to improve image quality. Both Suzuki and Cai disclosed known methods for correcting pixel color errors or improving data. Applying these known image processing techniques to Fisker’s system would have been an obvious way to produce more accurate and clear images with more accurate color data.
  • Expectation of Success: The combination was allegedly predictable, as it involved applying known software-based pixel correction algorithms (from Suzuki or Cai) to an existing image processor (Fisker’s) to achieve the expected benefit of improved image quality.

Ground 4: Claims 31 and 32 are obvious over Thiel425, Thiel576, and Tanaka

• Prior Art Relied Upon: Thiel425 (Application # 2012/0075425), Thiel576 (Application # 2011/0080576), and Tanaka (Application # 2015/0029367).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Thiel425, a handheld dental camera, taught a focus scanner that determines surface geometry from a stack of 2D images captured using a polychromatic light source. However, Thiel425 did not explicitly disclose determining surface color. Thiel576, from the same inventor and assignee, allegedly supplied this teaching by disclosing a similar device that determines surface color. The combination of Thiel425 and Thiel576 was argued to teach a focus scanner that records both geometry and color. Tanaka was then added to this combination to supply the teachings of a color filter array with >50% of one color and the specific 6x6 filter arrangement, for the same reasons as in Ground 1.
  • Motivation to Combine: A POSITA would combine Thiel425 and Thiel576 because they share the same inventor and assignee, were filed closely in time, and address complementary aspects of 3D dental imaging (geometry and color). A POSITA would have been further motivated to add Tanaka’s filter array to the combined Thiel device to improve its image resolution and reduce false color artifacts, a known problem with conventional color filters.
  • Expectation of Success: Success would be expected as the combination involved integrating complementary, known technologies from the same technical field (and same inventor) to create an improved, but predictable, system.

• Additional Grounds: Petitioner asserted additional obviousness challenges for claim 34 based on combinations of Thiel425, Thiel576, Fisker, and either Suzuki or Cai (Grounds 5 and 6), relying on similar theories for improving image quality by applying known pixel averaging techniques.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not deny institution under 35 U.S.C. §325(d). Although the primary reference, Fisker, was before the Examiner during prosecution, the secondary references (Tanaka, Suzuki, Cai) were not. Petitioner contended these new references teach the specific limitations that the patentee added to the claims to overcome the Examiner’s rejection over Fisker. Therefore, the Examiner never considered the asserted combinations, and the petition raised new arguments not previously before the USPTO.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and cancellation of claims 31-32 and 34 of the ’244 patent as unpatentable.