Zillow Group Inc v. IBM Corp

1. Case Identification

• Case #: IPR2021-01311
• Patent #: 7,543,234
• Filed: July 23, 2021
• Petitioner(s): Zillow Group, Inc. and Zillow, Inc.
• Patent Owner(s): International Business Machines Corp.
• Challenged Claims: 1, 3-7, 9-13, and 15-18

2. Patent Overview

• Title: Stacking Portlets in Portal Pages
• Brief Description: The ’234 patent discloses a graphical user interface (GUI) method for displaying information from multiple "portlets" on a portal page. The invention addresses the problem of a cluttered display by organizing subsets of portlets into "stacks," which reduces the screen space they occupy and is particularly useful for devices with limited screen real estate.

3. Grounds for Unpatentability

Ground 1: Anticipation over Chowdhry - Claims 1, 3-7, 9-13, and 15-18 are anticipated by Chowdhry.

• Prior Art Relied Upon: Chowdhry (Application # 2003/0167315).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Chowdhry teaches a system for creating custom web portals with portlets that can be arranged and layered. Chowdhry’s system allows portlets to be tiled "on top of or underneath other portlets," which inherently requires a determination of whether portlets are stackable. Petitioner contended this layering is managed by a "ZIndex," explicitly teaching the stacking of individual portlets. Furthermore, Chowdhry’s multi-page interface, which is "similar to a spreadsheet" with tabs, was alleged to teach the claimed "stack of stacks." In this system, each tabbed page represents a stack of portlets, and the collection of tabbed pages functions as a stack of these stacks. The tabs themselves serve as the claimed "control" for selecting a different stack of portlets (i.e., a different page) that is not currently presented. Dependent claims related to examining content, loading user profiles, and specific control types (tabs, buttons) were also argued to be disclosed in Chowdhry's description of its customizable, user-profile-driven interface.

Ground 2: Obviousness over MacLaurin and Masselle - Claims 1, 3-7, 9-13, and 15-18 are obvious over MacLaurin in view of Masselle.

• Prior Art Relied Upon: MacLaurin (Application # 2005/0210416) and Masselle (Application # 2006/0041846).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that MacLaurin discloses a GUI for efficiently previewing content from a collection of items arranged in a visual "stack." Users can scroll through the stack to view different items, which conserves screen space. While MacLaurin provides the foundational concept of a stacked interface for navigating content, Masselle teaches a method for organizing a plurality of windows in a "cascade stack," where each window can comprise a plurality of portlets from a web portal. Petitioner argued a POSITA would find it obvious to implement MacLaurin's stacked collections using Masselle's specific teaching of cascaded windows containing portlets, thereby arriving at the claimed invention.
  • Motivation to Combine: Petitioner argued a POSITA would combine MacLaurin and Masselle to achieve a predictable improvement in GUI design. Both references address the common problem of managing cluttered displays and presenting information efficiently. A POSITA would have been motivated to apply the more specific portlet-based cascade stack of Masselle to MacLaurin’s general stacked interface to provide better order and structure for displaying web-based content. This combination would predictably result in an improved GUI that efficiently presents maximum content from disparate sources.
  • Expectation of Success: Petitioner contended a POSITA would have a high expectation of success because combining the references was a straightforward application of a known technique (cascading windows with portlets) to a known system (a stacked GUI for content presentation) to yield predictable results. No technical obstacles would have prevented this combination.

4. Key Claim Construction Positions

• Petitioner argued for an express construction of "stack(s)" and its variants, as the term is central to patentability. The proposed construction for "stack(s)" (noun) is "an arrangement where a plurality of portlets are at least partially overlapping." Petitioner contended this construction is necessary to give the term meaning in the context of GUI design, where stacking saves screen real estate, an explicit goal of the ’234 patent. This position was supported by arguments that:
  • The patent specification contrasts stacking with cluttered, non-overlapping arrangements.
  • The prosecution history shows the Patent Owner distinguished a prior art reference (Lillie) by arguing Lillie’s fully visible, non-overlapping portlets did not teach "stacking."
  • The technical concept of Z-ordering, fundamental to GUIs, dictates that stacked or layered objects necessarily overlap to define their front-to-back order.
• Based on this core definition, Petitioner proposed that a "stack of stacks" is an arrangement where a stack of overlapping portlets has at least a partial overlap with another stack of overlapping portlets.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be improper because none of the prior art references (Chowdhry, MacLaurin, Masselle) were previously presented to or considered by the USPTO during the prosecution of the ’234 patent.
• Petitioner also argued that denial under the Fintiv factors is unwarranted. The parallel district court litigation has been stayed pending the outcome of the IPR, and there has been minimal investment in the court proceeding, with no trial date set, no claim construction briefing, and no significant discovery. Petitioner asserted that these factors, combined with the strong merits of the invalidity grounds presented, weigh heavily against discretionary denial and in favor of institution.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 3-7, 9-13, and 15-18 of the ’234 patent as unpatentable.