Princeps Interface Tech LLC v. Google LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Princeps Interface Technologies LLC (Delaware)
  • Defendant: Alphabet Inc., and Google LLC (Delaware)
  • Plaintiff’s Counsel: Devlin Law Firm LLC; Toler Law Group, PC
• Case Identification: 1:19-cv-01102, D. Del., 06/14/2019
• Venue Allegations: Venue is alleged to be proper because both Defendants are Delaware corporations and therefore reside in the District of Delaware.
• Core Dispute: Plaintiff alleges that Defendants’ Pixel phones and Android operating system, which provide keyboard functionalities, infringe a patent related to multifunctional data input devices.
• Technical Context: The technology concerns user interfaces for data entry on compact electronic devices, a field of central importance to the design and operation of modern smartphones and portable electronics.
• Key Procedural History: The complaint does not mention any prior litigation, inter partes review (IPR) proceedings, or specific licensing history related to the patent-in-suit. The willfulness allegation is based on knowledge acquired from the filing of the complaint itself.

Case Timeline

Date	Event
2001-09-20	Priority Date for U.S. Patent No. 6,703,963
2004-03-09	U.S. Patent No. 6,703,963 Issued
2019-06-14	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,703,963 - "Universal Keyboard"

Issued: March 9, 2004 (’963 Patent)

The Invention Explained

• Problem Addressed: The patent addresses the limitations of traditional QWERTY keyboards when used with increasingly smaller portable electronic devices. These keyboards are described as being too large for one-handed operation, having an inefficient key layout, and typically being limited to a single function (alphanumeric input), which is insufficient for modern multifunctional devices (Compl. ¶16; ’963 Patent, col. 1:37-2:23).
• The Patented Solution: The invention is a "multifunctional input device" that uses a limited number of programmable keys to perform a wide range of tasks. This is achieved through a hierarchical control system featuring selectable "functional modes" (e.g., alphanumeric, telephone, calculator) and, within each mode, multiple "domain levels" (e.g., letters A-L, letters M-X). The function of each key changes based on the selected mode and level, and a display associated with each key indicates its current assigned value. (’963 Patent, Abstract; ’963 Patent, col. 2:33-45). This allows a compact keyboard to adapt to different applications.
• Technical Importance: The technology proposes a method to overcome the physical constraints of small devices by making the user interface dynamic and context-sensitive, a foundational concept for modern software keyboards. (’963 Patent, col. 2:16-23).

Key Claims at a Glance

• The complaint asserts independent claims 1 and 60, along with several dependent claims. (Compl. ¶27).
• Independent Claim 1: An information input device comprising:
  • a functional mode control for selecting a first functional mode of operation.
  • a domain control for selecting one of multiple domain levels within the first functional mode.
  • a plurality of input keys, separate and distinct from the domain control, assigned to the set of domain-level values associated with a selected domain level and functional mode.
  • a function-specific display indicating a domain-level value associated with each input key for a currently selected functional mode and domain level.
  • wherein the input keys and domain control are simultaneously presented by the input device.
• The complaint reserves the right to assert additional claims, including dependent claims 2, 3, 9, and 12. (Compl. ¶27).

III. The Accused Instrumentality

Product Identification

• The "Accused Instrumentalities" are identified as "Pixel phones with proprietary Google Apps and/or third-party Apps with keyboard functionalities and an operating system such as the Android operating system." (Compl. ¶27).

Functionality and Market Context

• The complaint targets the software-based keyboard interfaces within the Android operating system. These interfaces provide users with on-screen keys for data input. The functionality of these software keyboards is dynamic; the layout and characters available on the keys can change depending on the application being used (e.g., a dialer app versus a web browser) or user selection (e.g., switching from letters to numbers and symbols). (Compl. ¶27). The complaint notes the significant market presence and revenue of the Defendants, implying the commercial importance of the accused products. (Compl. ¶34).

IV. Analysis of Infringement Allegations

The complaint references "preliminary and exemplary claim charts" in Exhibit A-1 to detail its infringement theory. (Compl. ¶27). However, this exhibit was not attached to the publicly filed complaint. The narrative allegations suggest an infringement theory where the software-based user interfaces in Android meet the elements of the claims of the ’963 patent.

For example, selecting an application (like a phone dialer or a messaging app) on an Android device is likely alleged to be equivalent to selecting a "functional mode." Within an application, the on-screen keyboard's ability to switch between layouts (e.g., from alphabetic to numeric or symbolic) is likely alleged to satisfy the "domain control" limitation. The individual character keys on the software keyboard are alleged to be the "plurality of input keys," and the visual representation of characters on those keys on the device's screen is alleged to be the "function-specific display." (Compl. ¶27).

Identified Points of Contention

• Scope Questions: A central dispute may arise over whether the claim terms, which are depicted in the patent’s figures as distinct physical hardware buttons (e.g., ’963 Patent, Fig. 5a, items 10, 20), can be construed to read on integrated software components of a graphical user interface. Specifically, can selecting an application on a touchscreen be considered a "functional mode control," and can tapping a soft key like "?123" be considered a "domain control"?
• Technical Questions: The court may need to resolve whether the accused Android keyboards are "separate and distinct" from the control elements that change their state. The claim requires that the "plurality of input keys" be "separate and distinct from the domain control." On a touchscreen interface, both the keys and the controls that modify them are software elements displayed on the same surface, which raises the question of whether they are structurally "separate and distinct" in the manner contemplated by the patent.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

"a domain control"

• Context and Importance: The definition of "domain control" is critical because it forms the second level of the claimed input hierarchy. The infringement allegation appears to equate this control with a software button on an on-screen keyboard (e.g., a button to switch to a numeric or symbol layout). The defense may argue that this term, as disclosed in the patent, requires a physically separate, continuously present hardware control distinct from the input keys themselves.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claims use the general term "control" without explicitly limiting it to hardware. The patent also discusses its application to PDAs and cell phones, devices that evolved to heavily rely on software interfaces. (Compl. ¶¶19-21; ’963 Patent, col. 3:56-64).
  • Evidence for a Narrower Interpretation: Every embodiment and figure in the patent depicts the "domain control" as a physical button (e.g., buttons 20 in Fig. 5a). (See, e.g., ’963 Patent, Fig. 5a, col. 4:45-53). The specification describes "domain-level controls 20" as being located on the keyboard and distinct from the "programmable input keys 30." (’963 Patent, col. 4:20-24).

"input keys, separate and distinct from the domain control"

• Context and Importance: This limitation requires a structural separation between the keys used for data entry and the control used to change the "domain." Practitioners may focus on this term because, in the accused software keyboards, the "domain control" (e.g., a "?123" key) is often presented as just another key within the same keyboard matrix. The case may turn on whether being a different software object on a screen is legally "separate and distinct."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term does not specify the type or degree of separation. Plaintiff may argue that being functionally different and visually distinguishable on a GUI is sufficient to meet the "separate and distinct" requirement.
  • Evidence for a Narrower Interpretation: The patent consistently illustrates the domain controls (20) and the input keys (30) as physically separate, non-overlapping hardware buttons with different form factors and locations on the device housing. (’963 Patent, Fig. 1, Fig. 5a). This could support a construction requiring more than just functional difference within a unified software interface.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendants provide "instructional materials and/or services" that encourage infringing use by customers. (Compl. ¶32). It also alleges contributory infringement, asserting that the Accused Instrumentalities are "especially made or adapted for use in an infringement" and are "not a staple article of commerce suitable for substantial non-infringing use." (Compl. ¶33).
• Willful Infringement: Willfulness is alleged based on Defendants having knowledge of the patent and their infringement "at least as early as the filing of this Complaint." (Compl. ¶29). The complaint also makes a conclusory allegation of willful infringement against Apple, though Apple is not a party to the suit. (Compl. ¶35).

VII. Analyst’s Conclusion: Key Questions for the Case

The resolution of this dispute will likely depend on the answers to a few central questions of claim construction and application, framed by the transition from the hardware-centric computing era of the patent's priority date to the software-dominant environment of the accused products.

1. A core issue will be one of definitional scope: Can the claim terms "functional mode control" and "domain control," which the patent specification and figures depict as physical hardware buttons, be construed to cover purely software-based interactions like launching an application or tapping a key on a virtual keyboard in the Android OS?
2. A second key issue will be structural interpretation: Do the accused on-screen keyboards, where controls for changing layouts are presented alongside and as part of the keyboard matrix itself, satisfy the claim requirement that the "input keys" be "separate and distinct from the domain control"?
3. Finally, a key evidentiary question will be whether the operation of the accused Android keyboards maps to the specific, two-tiered hierarchical system recited in the claims (a selection of a "functional mode" followed by a selection of a "domain level"), or if they operate in a manner that is technically distinguishable from this patented method.