DCT
8:25-cv-01591
Motiverse Inc v. Logitech Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Motiverse Inc. (South Korea)
- Defendant: Logitech, Inc. (Washington)
- Plaintiff’s Counsel: Broadview IP LAW, PC
- Case Identification: 8:25-cv-01591, C.D. Cal., 07/22/2025
- Venue Allegations: Venue is alleged to be proper in the Central District of California because Defendant Logitech maintains a regular and established place of business in Irvine, California, within the district.
- Core Dispute: Plaintiff alleges that Defendant’s gaming mice, which feature "Lift Off Distance" (LOD) detection, infringe a patent related to methods for preventing erroneous cursor movement when an optical mouse is lifted from a surface.
- Technical Context: The technology addresses the problem of unintended cursor drift that occurs when an optical mouse's sensor receives an out-of-focus image as it is lifted and repositioned by a user.
- Key Procedural History: The asserted patent was subject to a chain of assignments, originating with the inventor, then to ATLab Inc., Intellectual Discovery Co., LTD., and finally to Plaintiff Motiverse Inc. on May 1, 2025. The patent expired on September 4, 2024, prior to the filing of the complaint; therefore, the lawsuit seeks only monetary damages for past infringement.
Case Timeline
| Date | Event |
|---|---|
| 2002-07-30 | '338 Patent Priority Date |
| 2003-07-16 | '338 Patent assigned to ATLab Inc. |
| 2006-08-08 | '338 Patent Issued |
| 2013-06-17 | '338 Patent assigned to Intellectual Discovery Co., LTD. |
| 2024-09-04 | '338 Patent Expired |
| 2025-05-01 | '338 Patent assigned to Plaintiff Motiverse Inc. |
| 2025-07-22 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
- Patent Identification: U.S. Patent No. 7,088,338, “Optical Mouse and Method for Preventing an Erroneous Operation Thereof,” issued August 8, 2006.
The Invention Explained
- Problem Addressed: The patent’s background section describes an issue with conventional optical mice where, if the mouse is lifted from its operating surface, the image captured by the sensor becomes out-of-focus. This can be misinterpreted as movement, causing the on-screen cursor to move erratically even though the mouse is not being moved horizontally ('338 Patent, col. 1:42-59; Compl. ¶16).
- The Patented Solution: The invention proposes a system to detect when the mouse has been lifted and, in response, to halt the output of movement data. It accomplishes this by adding components that calculate a "statistic value" (e.g., an average) of the pixel data from the image sensor. When this value drops below a certain threshold—indicating less light is being reflected because the mouse is far from the surface—a "pick-up state discriminator" generates a signal that forces the moving value to "0", preventing cursor drift ('338 Patent, Abstract; col. 3:52-62).
- Technical Importance: This approach provides a method for an optical mouse to distinguish between intentional horizontal movement and unintentional z-axis (lift) movement, a key feature for users, particularly gamers, who frequently lift and reposition their mice during use (Compl. ¶24).
Key Claims at a Glance
- The complaint asserts independent claim 1 and dependent claim 2 ('338 Patent, col. 6:10-30; Compl. ¶14).
- The essential elements of independent claim 1 (as corrected) include:
- an image sensor
- an A/D converter
- an image data processor for calculating a moving value
- a system controller
- a statistic value calculator for calculating a statistic value
- a pick-up state discriminator for receiving the output of the statistic value calculator and generating a pick-up state signal
- wherein the pick-up state signal is used to make the moving value "0"
- The complaint reserves the right to assert additional claims ('338 Patent, col. 6:10-65; Compl. ¶31).
III. The Accused Instrumentality
Product Identification
- The complaint accuses Logitech's wired and wireless gaming mice, including but not limited to the G403, G502, G703, G900, G903, and G Pro models (Compl. ¶¶25, 38).
Functionality and Market Context
- The accused functionality is the "Lift Off Distance" (LOD) feature, which stops the mouse from tracking movement once it is lifted a certain distance from the operating surface (Compl. ¶24). This feature is described as particularly important for gamers who use low-sensitivity settings and frequently reposition their mice (Compl. ¶24).
- The complaint alleges this functionality is implemented using customized optical sensors from PixArt Imaging Inc., specifically the PMW3366 sensor, which is alleged to be based on the PMW3360 sensor and to share its hardware architecture for lift detection (Compl. ¶¶26-28). The complaint alleges that the PMW3360's datasheet describes a function for "finding the average raw data value of an image frame and reporting a lift state" (Compl. ¶29).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
Claim Chart Summary
The complaint does not include a claim chart as an exhibit, but its narrative allegations in paragraphs 26 through 30 provide a basis for the following summary of the infringement theory for Claim 1.
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| an image sensor, consisted of a plurality of pixels, for outputting signals accumulated in a given time as a pixel unit; | The accused products are equipped with optical sensors from PixArt Imaging Inc. (e.g., PMW3366), which contain an image sensor. | ¶26 | col. 3:15-17 |
| an A/D converter for receiving the output of the image sensor and converting the output into a digital signal format; | The PixArt PMW3360/PMW3366 sensors are alleged to contain the necessary hardware architecture, which would include an A/D converter. | ¶28 | col. 3:17-20 |
| an image data processor for receiving the output of the A/D converter and calculating a moving value of the optical mouse; | The PixArt chip is described as an "optical navigation chip" for "tracking movement." | ¶¶28, 29 | col. 3:20-23 |
| a system controller for controlling data flow with an external system and receiving the image data processor; | This functionality is inherent to the operation of a computer mouse that communicates with a computer. | ¶23 | col. 3:26-29 |
| a statistic value calculator for receiving the output of the A/D converter and calculating a statistic value; | The complaint alleges the datasheet for the PMW3360 sensor describes "finding the average raw data value of an image frame" and performs lift detection by "comparing the average of the pixels." | ¶¶29, 30 | col. 3:23-26 |
| a pick-up state discriminator for receiving the output of the statistic value calculator and generating a pick-up state signal, | The complaint alleges the PMW3360 sensor "determines if an optical navigation system has been lifted" and "report[s] a lift state." | ¶¶29, 30 | col. 3:55-59 |
| wherein the pick-up state signal is used to make the moving value "0". | The complaint alleges the accused feature "prevents cursor movement on a corresponding computer if a lift has been detected." | ¶30 | col. 3:59-62 |
Identified Points of Contention
- Scope Questions: A central question will be whether the commercially understood term "Lift Off Distance" (LOD) and the accused sensor's "lift state" fall within the scope of the patent's term "pick-up state." The defense may argue that LOD is a distinct, non-infringing technology, while the plaintiff will argue they are functionally the same.
- Technical Questions: The complaint alleges the accused sensor works by "comparing the average of the pixels...against a predetermine[d] threshold value" (Compl. ¶30). The case may turn on whether this alleged operation satisfies both the "statistic value calculator" and "pick-up state discriminator" limitations, or if the claims require two structurally or functionally distinct components.
V. Key Claim Terms for Construction
The Term: "statistic value" (Claim 1)
Context and Importance: This term is the core of the claimed invention's detection mechanism. The definition will determine what types of calculations qualify. Practitioners may focus on this term because the complaint's allegations are based on an "average raw data value" (Compl. ¶29), which aligns with an embodiment but may not cover all possible statistical methods.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The use of the general term "statistic value" in independent claim 1 could suggest that the invention is not limited to any single type of statistical calculation.
- Evidence for a Narrower Interpretation: Dependent claim 2 explicitly recites that "the statistic value is obtained by averaging the pixel value" ('338 Patent, col. 6:29-30). Under the doctrine of claim differentiation, this may suggest the independent claim is broader than just averaging. However, the specification repeatedly refers to calculating an "average value" as the primary method for detecting the pick-up state, which could be used to argue the invention is limited to averaging or its close equivalents ('338 Patent, col. 3:52-56).
The Term: "pick-up state discriminator" (Claim 1)
Context and Importance: This term defines the component that makes the decision to generate the "pick-up state signal." Its construction is critical to determining whether the alleged functionality of the PixArt sensor—"comparing the average...against a predetermine[d] threshold" (Compl. ¶30)—meets this limitation, or if this alleged function is performed by the "statistic value calculator" instead.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes this component's function simply as "judg[ing] whether the optical mouse is spaced apart from the operating surface" based on the average pixel value becoming "below the reference level continuously" ('338 Patent, col. 3:55-59). This functional description could be read broadly onto any component that performs this threshold comparison.
- Evidence for a Narrower Interpretation: The block diagram in Figure 3 shows the "PICK-UP STATE DISCRIMINATOR" (46) as a distinct block from the "AVERAGE VALUE CALCULATOR" (45). A defendant may argue this requires a separate structure or module, and that a single computational step of comparing an average to a threshold does not meet both limitations.
VI. Other Allegations
Indirect Infringement
- The complaint alleges induced infringement, stating that Logitech encourages infringement through its "marketing materials, technical specifications, data sheets, web pages on its website, press releases, and user manuals" (Compl. ¶40). It also alleges contributory infringement, asserting that the accused products are "specially made or adapted for use in infringement" and are "not staple articles of commerce suitable for substantial non-infringing use" (Compl. ¶42).
Willful Infringement
- The complaint does not allege pre-suit knowledge of the '338 patent. It asserts that Logitech gained knowledge upon the "filing and service of this Complaint" (Compl. ¶36). This allegation would only support a claim for post-filing willful infringement. The prayer for relief seeks a finding that the case is "exceptional" under 35 U.S.C. § 285, which could entitle the plaintiff to attorneys' fees (Compl. p. 13).
VII. Analyst’s Conclusion: Key Questions for the Case
- Claim Scope and Expiration: Given that the patent expired before the suit was filed, the case is exclusively a backward-looking action for past damages. A primary issue will be establishing the extent of infringing sales that occurred during the enforceable term of the patent.
- Definitional Mapping: A core issue will be one of definitional scope: can the commercial feature known as "Lift Off Distance" (LOD) in the accused Logitech mice be construed as the same thing as the "pick-up state" described and claimed in the '338 patent? The outcome will depend heavily on the court's construction of the claim terms "statistic value" and "pick-up state discriminator."
- Evidentiary Challenge: A key evidentiary question will be one of technical proof: what evidence can be developed in discovery to show that the internal operation of the accused PixArt sensors, which the complaint alleges involves "comparing the average of the pixels," actually performs the specific steps recited in the asserted claims? The details of the sensor's algorithm and hardware architecture will be central to the infringement analysis.