Align Technology Inc v. 3Shape AS

1. Case Identification

• Case #: PGR2018-00104
• Patent #: 9,962,244
• Filed: October 26, 2018
• Petitioner(s): Align Technology, Inc.
• Patent Owner(s): 3Shape A/S
• Challenged Claims: 31, 32, and 34

2. Patent Overview

• Title: Focus Scanner for Recording Surface Geometry and Surface Color of an Object
• Brief Description: The ’244 patent relates to systems and methods for three-dimensional (3D) scanning of an object's surface geometry and color, particularly for intraoral dental scanning. The technology uses a focus scanner with a multichromatic light source to capture a series of 2D images at different focal planes, which are then processed to generate a 3D digital representation expressing both geometry and color.

3. Grounds for Unpatentability

Ground 1: Obviousness over Fisker and Tanaka - 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 the core elements of a focus scanner for recording 3D geometry and color as claimed. This included a multichromatic light source, a color image sensor, and a data processing system configured to capture a series of 2D images at different focal planes (a "stack") to derive surface geometry and color information. Petitioner contended that Tanaka was necessary to teach the specific color filter array limitations not disclosed in Fisker, such as an array where the proportion of pixels for a selected wavelength is larger than 50% (claim 31) and a specific arrangement of filters in a 6x6 cell (claim 32). Tanaka disclosed color filter arrays with a majority of green filters (>50%) and illustrated a 6x6 pixel pattern.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Tanaka's improved color filter scheme with Fisker's scanner to improve image quality. Fisker’s system was aimed at improving spatial resolution, and Tanaka’s filter array was known to improve resolution and suppress false colors compared to a standard Bayer filter, which Fisker disclosed as an option. The combination was presented as the application of a known, superior filtering technique to a known type of imaging apparatus to achieve a predictable improvement.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as modifying Fisker’s color filters and software to accommodate Tanaka’s scheme would involve routine engineering practices.

Ground 2: Obviousness over Fisker with Averaging Techniques - 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 disclosed most limitations of claim 34, including deriving surface geometry and color by calculating a correlation measure between portions of 2D images and a weight function, and identifying the position of maximum correlation. However, Petitioner argued Fisker did not explicitly teach the final limitation of claim 34: "computing an averaged sub-scan color for a number of points of the sub-scan, where the computing comprises an averaging of sub-scan colors of surrounding points on the sub-scan." Suzuki and Cai were introduced to supply this missing element. Suzuki disclosed a method for correcting defective pixels using a weighted average of surrounding pixel values, and Cai taught interpolating a pixel’s color value from the average of adjacent pixels of the same color.
  • Motivation to Combine: A POSITA would combine Fisker with Suzuki or Cai to improve image accuracy and quality. Since Fisker’s system generates 3D images, incorporating known techniques for pixel color correction or interpolation from Suzuki or Cai would be a predictable way to produce a more accurate and clear final image. This modification would enhance Fisker's existing image processing capabilities.
  • Expectation of Success: There would be a high expectation of success because implementing the averaging methods of Suzuki or Cai would primarily involve software modifications to Fisker's data processor, not additional hardware, which would be a routine matter for a POSITA.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations starting with Thiel425 (Application # 2012/0075425) and Thiel576 (Application # 2011/0080576) as the primary references, combined with Tanaka, Fisker, Suzuki, and Cai to challenge claims 31, 32, and 34. These grounds relied on similar theories of combining known scanning technologies with known image processing and filter array techniques.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should institute trial notwithstanding 35 U.S.C. § 325(d). The core argument was that while the primary reference, Fisker, was before the Examiner during prosecution, the secondary references (Tanaka, Suzuki, Cai, etc.) that teach the key limitations added to overcome the Examiner’s rejections were not. Petitioner asserted the Examiner performed a limited search and allowed the claims based on these added limitations without considering the newly cited prior art, which allegedly rendered those limitations obvious. Therefore, the petition presented new arguments and art combinations that were not previously evaluated by the PTO.

5. Relief Requested

• Petitioner requests institution of post-grant review (PGR) and cancellation of claims 31, 32, and 34 as unpatentable.