DCT
5:23-cv-01544
Sitime Corp v. WordLogic Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: SiTime Corporation (Delaware)
- Defendant: WordLogic Corporation (Nevada) and 602531 British Columbia Ltd. (Canada)
- Plaintiff’s Counsel: Greenberg Traurig, LLP
- Case Identification: 3:23-cv-01544, N.D. Cal., 03/31/2023
- Venue Allegations: Plaintiff alleges venue is proper because its principal place of business is in the district and Defendants have purposefully directed patent enforcement activities into the district, including by filing prior litigation in the district asserting two of the patents-in-suit.
- Core Dispute: Plaintiff seeks a declaratory judgment that it does not infringe four of Defendants’ patents and that the patents are invalid, following Defendants’ communications alleging that the predictive text search box on Plaintiff’s website infringes.
- Technical Context: The patents relate to methods for predictive text entry and disambiguation, a foundational technology for improving user input speed and accuracy on computing devices.
- Key Procedural History: The complaint notes that the U.S. Patent and Trademark Office previously instituted an inter partes review (IPR) proceeding (IPR2017-01856) against U.S. Patent No. 7,681,124, one of the patents-in-suit, finding a "reasonable likelihood" that its claims were unpatentable based on prior art. Such a finding, while not a final determination, may suggest a potential vulnerability for that patent’s validity arguments in this litigation.
Case Timeline
| Date | Event |
|---|---|
| 1999-03-18 | Priority Date for ’231, ’124, and ’579 Patents |
| 2005-01-13 | Priority Date for ’984 Patent |
| 2007-11-06 | U.S. Patent No. 7,293,231 Issues |
| 2010-03-16 | U.S. Patent No. 7,681,124 Issues |
| 2010-05-11 | U.S. Patent No. 7,716,579 Issues |
| 2013-10-08 | U.S. Patent No. 8,552,984 Issues |
| 2023-02-08 | WordLogic entities send letter to SiTime alleging infringement |
| 2023-03-31 | Complaint for Declaratory Judgment Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,293,231 - "Data Entry for Personal Computing Devices"
The Invention Explained
- Problem Addressed: The patent addresses the inefficiency and difficulty of entering text on personal computing devices, particularly miniaturized ones like PDAs, where traditional keyboards are impractical and on-screen "hunt-and-peck" typing is slow (ʼ231 Patent, col. 1:25-59). Existing text completion systems are described as needing more flexibility (ʼ231 Patent, col. 2:8-12).
- The Patented Solution: The invention proposes a data entry system where a user enters a partial text string, and the system displays a list of "completion candidates" (ʼ231 Patent, Abstract). A central feature is an "iterative search" capability: a user can select a candidate from the list not just for final entry, but also as the basis for a new, more refined search for additional candidates. This refinement can be triggered, for instance, if a candidate "remains selected for a predetermined time limit" (ʼ231 Patent, col. 2:55-3:10; col. 16:25-34).
- Technical Importance: This iterative refinement method aimed to accelerate text entry by allowing users to quickly narrow down long words or phrases without typing every character, a significant usability improvement for devices with limited input methods (ʼ231 Patent, col. 2:58-65).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claim 1 (Compl. ¶32).
- Essential elements of claim 1 include:
- Receiving a partial text entry.
- Obtaining and displaying a list of completion candidates in a search list.
- Receiving a user input signal corresponding to different types of user selections.
- Deactivating the search list for a first type of selection.
- Replacing the partial text entry with a candidate for a second type of selection.
- Obtaining a refined list of completion candidates for display "when a completion candidate in the search list remains selected for a predetermined time limit."
- The complaint seeks a declaration of non-infringement for all claims of the patent, which would include dependent claims (Compl. ¶40).
U.S. Patent No. 7,681,124 - "Data Entry for Personal Computing Devices"
The Invention Explained
- Problem Addressed: As a divisional of the application leading to the ʼ231 Patent, this patent addresses the same technical problem of inefficient text entry on computing devices (ʼ124 Patent, col. 1:25-59).
- The Patented Solution: The patent describes the same core system of combining keyboard input with a predictive, iterative search list (ʼ124 Patent, Abstract). This patent's claims focus on a different aspect of the iterative search process, specifically what happens when a candidate is "accepted."
- Technical Importance: This approach provided another method for users to progressively refine search results, streamlining the process of finding and entering the correct text without extensive manual typing (ʼ124 Patent, col. 2:55-65).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claim 19 (Compl. ¶¶18, 32).
- Essential elements of claim 19 include:
- Displaying a search list of completion candidates in response to a partial text entry.
- Receiving a user input signal corresponding to acceptance of a candidate to replace the partial text entry.
- Displaying a modified plurality of completion candidates based on the partial text entry.
- Obtaining and displaying a "further modified plurality of completion candidates... if a completion candidate is accepted via the search list from the modified plurality of completion candidates."
- Displaying a digital keyboard when the search list is not displayed.
- The complaint seeks a declaration of non-infringement for all claims of the patent (Compl. ¶48).
U.S. Patent No. 7,716,579 - "Data Entry for Personal Computing Devices"
- Technology Synopsis: Belonging to the same family as the ’231 and ’124 Patents, this patent addresses inefficient text entry on computing devices. The solution is a system that presents completion candidates based on partial user input and allows for iterative searching, where selecting a candidate can trigger a refined search for more specific results (ʼ579 Patent, Abstract; col. 2:55-3:10).
- Asserted Claims: The complaint identifies independent claim 1 as being at issue (Compl. ¶¶18, 32).
- Accused Features: The complaint alleges that the "predictive text search box featured on the SITIME website" does not infringe, specifically noting that the accused functionality does not obtain a new list of candidates if one "remains selected for a predetermined time limit" (Compl. ¶¶18, 32).
U.S. Patent No. 8,552,984 - "Method, System, Apparatus and Computer-Readable Media for Directing Input Associated with Keyboard-Type Device"
- Technology Synopsis: This patent addresses a system-level method for processing user input. It describes redirecting input key events from a primary application (e.g., a word processor) to a secondary, function-enhancing process (e.g., a predictive text engine) when a user selects a key for a predetermined time period, and then redirecting the input back (ʼ984 Patent, Abstract).
- Asserted Claims: The complaint seeks a declaration of non-infringement for the patent generally, without identifying specific claims asserted by Defendants (Compl. ¶¶1, 57-64).
- Accused Features: The complaint accuses the "predictive text search box featured on the SITIME website" of non-infringement (Compl. ¶18).
III. The Accused Instrumentality
Product Identification
- The "predictive text search box featured on the SITIME website" (Compl. ¶18).
Functionality and Market Context
- The complaint describes the accused instrumentality as a feature on Plaintiff's website that provides predictive text functionality to aid users in searching (Compl. ¶18).
- The complaint provides minimal detail about the specific operation of the search box, focusing instead on what it allegedly does not do. The core of SiTime's non-infringement argument is that its search box lacks the specific iterative search functionalities required by the patent claims, such as obtaining a refined list of candidates when a selection is held for a "predetermined time limit" or is "accepted" to trigger a further search (Compl. ¶32).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
U.S. Patent No. 7,293,231 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) receiving a partial text entry comprising at least a first character; | The accused search box receives partial text entry from a user. | ¶18 | col. 12:15-18 |
| (b) obtaining a dynamically generated list of completion candidates based on the partial text entry; | The accused search box obtains and displays predictive text suggestions. | ¶18 | col. 12:20-24 |
| (g) obtaining a refined list of completion candidates for display in the search list when a completion candidate in the search list remains selected for a predetermined time limit. | The complaint alleges non-infringement by asserting that the accused search box does not perform the step of obtaining a refined list when a candidate is selected for a predetermined time limit. | ¶32 | col. 16:25-34 |
- Identified Points of Contention:
- Technical Questions: A primary factual question is whether user interactions with the SiTime search box—such as pausing a cursor over a suggestion—functionally meet the "remains selected for a predetermined time limit" limitation. The complaint provides no evidence on this point beyond a conclusory denial (Compl. ¶32).
- Scope Questions: The analysis may turn on whether "selected" requires an affirmative user action like a click, or if it can be read more broadly to cover actions like mouse-hovering, and what duration constitutes a "predetermined time limit."
U.S. Patent No. 7,681,124 Infringement Allegations
| Claim Element (from Independent Claim 19) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) displaying a search list of completion candidates... in response to a partial text entry; | The accused search box displays predictive text suggestions based on user input. | ¶18 | col. 12:15-18 |
| (d) obtaining and displaying in the search list a further modified plurality of completion candidates from among the group of completion candidates, if a completion candidate is accepted via the search list from the modified plurality of completion candidates. | The complaint alleges non-infringement by asserting that the accused search box does not obtain and display a "further modified" list after a candidate is "accepted." | ¶32 | col. 15:15-26 |
- Identified Points of Contention:
- Technical Questions: The dispute centers on whether "accepting" a candidate from SiTime's search box (e.g., by clicking it to populate the search field) subsequently triggers the display of a "further modified" list of candidates as the claim requires.
- Scope Questions: This raises the question of what constitutes "acceptance" under the claim. Does it mean a final selection to complete a search, or can it include an intermediate selection intended to refine the search further?
V. Key Claim Terms for Construction
- Patent: ’231 Patent
- The Term: "remains selected for a predetermined time limit" (from claim 1)
- Context and Importance: This phrase defines the specific trigger for the patented iterative search functionality. The entire infringement question for this claim may hinge on whether the accused search box performs an action that meets this definition. Practitioners may focus on this term because it links a specific user behavior (a timed pause) to a core inventive concept (search refinement).
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes user actions in general terms, such as generating a "gesture with the pointing device," which might not necessitate a definitive click (ʼ231 Patent, col. 13:58-62). The term "selected" could be argued to encompass highlighting or hovering.
- Evidence for a Narrower Interpretation: The detailed description of the process flow often distinguishes between gesturing "toward a candidate" to select it and subsequently "lifting" the pointing device to accept it, suggesting "selected" may be an intermediate state requiring more than a passive hover (ʼ231 Patent, Fig. 6A, steps 108, 114).
- Patent: ’124 Patent
- The Term: "if a completion candidate is accepted" (from claim 19)
- Context and Importance: This clause is the condition precedent for the claim's second refinement step. Whether SiTime's search box infringes depends on whether user interactions qualify as "acceptance" that in turn triggers a further modification of the candidate list.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term "accepted" is not explicitly defined, and could plausibly be interpreted to mean any user action that selects a candidate from the list to populate the text entry field, even for intermediate purposes.
- Evidence for a Narrower Interpretation: The specification describes accepting a candidate "for insertion into the text" to "permanently replace the partial text entry," after which the system "begins monitoring anew" (ʼ124 Patent, col. 15:22-40). This language may support a narrower construction where "acceptance" implies a final, rather than iterative, action.
VI. Other Allegations
- Indirect Infringement: The complaint seeks a declaratory judgment that it has not infringed the Asserted Patents "directly or indirectly, either literally or under the doctrine of equivalents" (Compl. ¶¶38, 46, 54, 62). The complaint does not set forth specific facts alleged by Defendants that would support a claim of indirect infringement.
- Willful Infringement: The complaint does not contain allegations related to willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
This declaratory judgment action appears to center on three key questions for the court:
- A core issue will be one of functional operation: Does the accused predictive text search box on SiTime’s website perform the specific, multi-step iterative search functions required by the asserted claims? The complaint frames this as a fundamental mismatch between the accused product’s operation and the claim language, particularly concerning actions triggered by timed selections or the "acceptance" of a candidate.
- The case will likely involve a significant dispute over claim scope: The construction of key claim terms, such as "remains selected for a predetermined time limit" and "if a completion candidate is accepted," will be critical. How broadly or narrowly these triggers are defined will likely determine whether the functionality of the accused website feature falls within the scope of the patents.
- A central challenge for the Defendants will be one of patent validity: The complaint highlights the prior institution of an inter partes review against the ’124 patent. This raises the question of whether the patents-in-suit, particularly those in the original patent family, can withstand invalidity challenges based on prior art that the PTO has already deemed to present a "reasonable likelihood" of unpatentability.