Microsoft Corp v. X1 Discovery Inc

1. Case Identification

• Case #: IPR2025-00253
• Patent #: 7,370,035
• Filed: December 19, 2024
• Petitioner(s): Microsoft Corporation
• Patent Owner(s): X1 Discovery, Inc.
• Challenged Claims: 1-10

2. Patent Overview

• Title: Methods and Systems for Search Indexing
• Brief Description: The ’035 patent describes a method for incremental, character-by-character searching where search results are displayed and updated in real-time as a user types a query. The claims specifically recite incrementally searching for two partial search strings entered into the same search field.

3. Grounds for Unpatentability

Ground 1: Claims 1-10 are obvious over the Lotus Notes references, Raskin, and Wu.

• Prior Art Relied Upon: Lotus Notes (Wilcox, a 1993 user guide; and Londergan, a 1999 user guide), Raskin (a 2000 textbook on interface design), and Wu (Patent 5,991,756).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the Lotus Notes references teach the core functionality of the claims: a search interface that receives multiple search strings (e.g., "gold" and "silver") separated by a Boolean operator ("AND") within a single search field to locate documents. However, Lotus Notes did not expressly disclose performing this search incrementally or using a backend intersection method. Raskin was introduced to supply the teaching of incremental (character-by-character) searching, describing it as a well-known and superior method for providing immediate user feedback. Wu was introduced to supply the teaching of the intersection approach, disclosing a standard method where a search engine locates documents containing multiple terms by searching for each term separately and then intersecting the result lists to find common documents.
  • Motivation to Combine: A POSITA would combine the multi-string search of Lotus Notes with Raskin’s incremental search functionality to achieve known benefits of speed, improved usability, and effectiveness, which Raskin explicitly states are applicable to Boolean searches. A POSITA would further incorporate Wu's intersection method because it was a simple, well-known, and predictable way to implement a multi-string search, and its separate processing of each search string is particularly well-suited for an incremental search where a user can modify each string independently.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining these teachings, as it would have required only simple and straightforward software modifications to an existing search system.

Ground 2: Claims 1-10 are obvious over the Entourage references, True, and Baeza-Yates.

• Prior Art Relied Upon: Entourage references (three user guides for Microsoft Entourage 2001, published 2000-2001), True (Patent 6,112,172), and Baeza-Yates (a 1999 textbook on information retrieval).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that the Entourage references teach an email client with an incremental "quick-find" search feature that displays results as a user types a search string into a single search field. This system performs prefix-based searching within various document types, including emails and contacts. However, the Entourage references did not explicitly teach incrementally searching for multiple partial strings in that single field. True was introduced to remedy this deficiency, as it expressly discloses an incremental search system that locates documents containing multiple search strings (e.g., "queen" and "mother") entered into a single search field. Baeza-Yates was then introduced to supply the well-known intersection approach for processing such multi-word queries, teaching that each keyword is searched separately to generate lists of results, which are then combined via Boolean operations to find documents containing all terms.
  • Motivation to Combine: A POSITA would combine the incremental search of Entourage with True’s teaching of multi-string searching to provide more targeted and relevant search results, a common-sense improvement. A POSITA would have been further motivated to implement this combination using the intersection method taught by Baeza-Yates because it was one of a few well-known, simple, and predictable ways to handle multi-word queries. This approach was particularly suitable for the incremental nature of the Entourage/True system.
  • Expectation of Success: A POSITA would have reasonably expected to succeed in this combination because it involved integrating known functionalities into a system with substantially similar features, requiring only straightforward software modifications.

4. Arguments Regarding Discretionary Denial

• §325(d) Arguments: Petitioner argued that discretionary denial under §325(d) is improper because the primary references relied upon in both grounds (Lotus Notes, Raskin, Wu, Entourage, Baeza-Yates) were never presented to or considered by the Examiner during prosecution. While the True patent was cited in an Information Disclosure Statement (IDS), it was never substantively addressed in a rejection, and Petitioner asserted that the Examiner erred in overlooking its clear teachings on the very feature—incrementally searching two strings in one field—that the Examiner found lacking in the other art of record.
• Fintiv Arguments: Petitioner argued against discretionary denial under Fintiv because the parallel district court litigation is stayed pending resolution of a related ITC proceeding. Furthermore, even absent the stay, the median time-to-trial in the district court would place the trial date near or after the statutory deadline for a Final Written Decision (FWD) in this IPR. Finally, Petitioner asserted that minimal resources have been invested in the court case, with discovery not yet having begun.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of the ’035 patent as unpatentable under 35 U.S.C. §103.