DCT
2:22-cv-00434
MEMS Innovations LLC v. TDK Corp
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: MEMS Innovations, LLC (Texas)
- Defendant: TDK Corporation (Japan) and TDK Corporation of America (California)
- Plaintiff’s Counsel: Alavi & Anaipakos PLLC
- Case Identification: 2:22-cv-00434, E.D. Tex., 11/11/2022
- Venue Allegations: Plaintiff alleges venue is proper for TDK Corporation as an alien corporation subject to personal jurisdiction, and for TDK Corporation of America based on its commission of infringing acts and maintenance of a regular and established place of business within the district.
- Core Dispute: Plaintiff alleges that Defendant’s ultrasonic Time-of-Flight sensors infringe two patents related to the design and manufacture of piezoelectric microelectromechanical systems (MEMS) speakers.
- Technical Context: The technology relates to MEMS-based piezoelectric transducers, which convert electrical signals into physical vibrations to create sound, and are used in a wide range of modern electronics for functions like proximity sensing and object detection.
- Key Procedural History: The patents-in-suit were originally assigned to the Electronics and Telecommunications Research Institute (ETRI) in Korea. Plaintiff MEMS Innovations asserts it is the exclusive licensee with the sole right to enforce the patents. The complaint alleges Defendant had knowledge of the patents as of November 7, 2022, four days prior to the filing of the suit.
Case Timeline
| Date | Event |
|---|---|
| 2007-12-07 | Priority Date for U.S. Patent No. 7,812,505 |
| 2007-12-18 | Priority Date for U.S. Patent No. 8,114,697 |
| 2010-10-12 | Issue Date for U.S. Patent No. 7,812,505 |
| 2012-02-14 | Issue Date for U.S. Patent No. 8,114,697 |
| 2022-11-07 | Alleged Date of Defendant's Knowledge of Patents |
| 2022-11-11 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,812,505 - Piezoelectric Microspeaker Using Microelectromechanical Systems and Method of Manufacturing the Same, issued October 12, 2010 ('505 Patent)
The Invention Explained
- Problem Addressed: The patent states that conventional MEMS-based microspeakers suffer from low output and have multiple resonance frequencies within the audible frequency band, which results in noise and poor sound quality (’505 Patent, col. 1:36-43).
- The Patented Solution: The invention proposes a piezoelectric microspeaker that includes a "resonance change unit," which is a patterned protrusion structure formed on the bottom of the device’s elastic layer by etching the underlying silicon substrate ('505 Patent, Abstract; col. 6:50-56). This unit is designed to vary the stiffness and mass of the speaker's diaphragm to shift the resonance frequency from the audible range to an inaudible one, thereby improving sound quality ('505 Patent, col. 2:10-16).
- Technical Importance: This design purports to improve the acoustic performance of miniaturized MEMS speakers without the added cost and complexity of alternative structures like wrinkling or hinges ('505 Patent, col. 1:45-50).
Key Claims at a Glance
- The complaint asserts independent claim 1 and alleges infringement of one or more claims (Compl. ¶¶21, 23).
- Independent Claim 1 requires:
- A piezoelectric microspeaker using microelectromechanical systems (MEMS), comprising:
- a piezoelectric layer disposed on an elastic thin layer; and
- a resonance change unit patterned on one of a bottom surface of the elastic thin layer and a top surface of the piezoelectric layer.
U.S. Patent No. 8,114,697 - Piezoelectric Microphone, Speaker, Microphone-Speaker Integrated Device and Manufacturing Method Thereof, issued February 14, 2012 ('697 Patent)
The Invention Explained
- Problem Addressed: The patent identifies low output as a key problem for conventional piezoelectric micro-speakers (’697 Patent, col. 1:41-43).
- The Patented Solution: The invention describes a piezoelectric speaker with a "differentially etched" piezoelectric plate. Specifically, the outer circumferential portion of the plate (the "vibration region") is fabricated to be thinner than the central portion where the electrode is located (the "piezoelectric strain region") ('697 Patent, col. 2:8-17). The patent suggests that making the outer region thinner allows it to vibrate more easily in response to strain, thereby generating sound more effectively and improving the speaker's properties ('697 Patent, col. 5:31-43).
- Technical Importance: This differential etching provides a method for potentially enhancing acoustic output in a MEMS device by selectively increasing the flexibility of the vibrating structure.
Key Claims at a Glance
- The complaint asserts independent claim 10 and alleges infringement of one or more claims (Compl. ¶¶38, 40).
- Independent Claim 10 requires:
- A piezoelectric speaker comprising:
- a silicon substrate;
- an insulating layer provided over the silicon substrate;
- a piezoelectric plate provided over the insulating layer, the piezoelectric plate including a piezoelectric strain region and a vibration region;
- a mating electrode provided in the piezoelectric strain region of the piezoelectric plate,
- wherein the piezoelectric plate is thinner in the vibration region than in the piezoelectric strain region.
III. The Accused Instrumentality
- Product Identification: The complaint identifies the "Chirp Sensors" as the accused products, including the Chirp CH101, CH201, ICU-10201, and ICU-20201 Ultrasonic Time-of-Flight (ToF) Sensors (Compl. ¶¶24, 41).
- Functionality and Market Context: The accused products are MEMS-based ultrasonic sensors that function as piezoelectric microspeakers (Compl. ¶¶6, 23). The complaint alleges they are used for a broad range of applications, including range-finding, object detection, robotics, drones, and augmented reality (Compl. ¶15). The complaint further alleges that Defendants' customers incorporate these sensors into various end-user products, such as smartphones and vehicles (Compl. ¶36). The complaint provides a scanning electron microscope (SCM) cross-section image of the CH101 sensor to illustrate its internal structure (Compl. ¶27, Fig. 1).
IV. Analysis of Infringement Allegations
'505 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a piezoelectric layer disposed on an elastic thin layer | The complaint alleges the accused Chirp Sensors contain a piezoelectric layer disposed on a polysilicon membrane, which functions as the elastic thin layer, as shown in an SCM image of the CH101 sensor (Compl. ¶27, Fig. 2). | ¶27 | col. 6:22-28 |
| a resonance change unit patterned on one of a bottom surface of the elastic thin layer... | The complaint identifies a "setback" structure, patterned on the bottom surface of the polysilicon membrane, as the claimed "resonance change unit," alleging it defines the resonance frequency of the transducer (Compl. ¶28, Fig. 3). | ¶28 | col. 6:50-61 |
- Identified Points of Contention:
- Scope Questions: The case may turn on the construction of "resonance change unit." The patent’s specification repeatedly frames the problem and solution around moving a resonance frequency from an audible band to an inaudible band ('505 Patent, col. 2:10-16). This raises the question of whether the term can be construed to cover a structure in an ultrasonic sensor that allegedly tunes a frequency that is already far outside the audible range.
- Technical Questions: What evidence demonstrates that the accused "setback" structure performs the function of a "resonance change unit" as described in the patent (i.e., by varying diaphragm stiffness and mass to shift resonance)? The complaint provides structural images but does not include data showing the functional effect of the setback on the sensor's resonance characteristics (Compl. ¶28).
'697 Patent Infringement Allegations
| Claim Element (from Independent Claim 10) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a piezoelectric speaker comprising: a silicon substrate; | The CH101 sensor is alleged to be a piezoelectric speaker that includes a silicon substrate (Compl. ¶44, Fig. 4). | ¶44 | col. 12:40-43 |
| an insulating layer provided over the silicon substrate; | A polysilicon membrane in the CH101 is identified as the claimed insulating layer provided over the silicon substrate, as depicted in an SCM cross-section (Compl. ¶44, Fig. 5). | ¶44 | col. 12:44-46 |
| a piezoelectric plate provided over the insulating layer, the piezoelectric plate including a piezoelectric strain region and a vibration region; | The CH101 is alleged to have a piezoelectric AlN plate disposed over the insulating layer, which includes both a piezoelectric strain region and a vibration region (Compl. ¶45). | ¶45 | col. 10:19-22 |
| a mating electrode provided in the piezoelectric strain region of the piezoelectric plate, | An SCM image is provided to show a "top electrode in Molybdenum" located in what is alleged to be the thicker piezoelectric strain region of the plate (Compl. ¶45, Fig. 6). | ¶45 | col. 10:23-25 |
| wherein the piezoelectric plate is thinner in the vibration region than in the piezoelectric strain region. | The complaint alleges that an SCM image of the CH101's piezoelectric plate shows that it is thinner in its outer portion (the alleged vibration region) than in its central portion (the alleged strain region) (Compl. ¶45). | ¶45 | col. 10:26-27 |
- Identified Points of Contention:
- Scope Questions: The definitions of "piezoelectric strain region" and "vibration region" will be critical. The dispute may focus on whether these terms are defined by specific structures (e.g., the area under the electrode versus the area outside it) or by function, and how to delineate their boundaries on the accused device.
- Technical Questions: While the complaint's SCM image appears to show a differential in thickness across the piezoelectric plate (Compl. ¶45, Fig. 6), a key technical question will be whether the identified thinner and thicker areas of the accused device correspond to the "vibration region" and "piezoelectric strain region" as those terms are used in the patent.
V. Key Claim Terms for Construction
'505 Patent: "resonance change unit"
- Context and Importance: This term, which does not appear to be a standard term of art, is the central inventive concept of the '505 Patent's asserted claim. Infringement will depend on whether the accused "setback" structure falls within the scope of this term.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself—"a resonance change unit patterned on..."—does not explicitly include a functional or purpose-based limitation ('505 Patent, col. 7:65-66). Plaintiff may argue that any patterned structure on the specified surface that alters resonance meets the claim.
- Evidence for a Narrower Interpretation: The specification strongly links the unit to a specific purpose: "to change a resonance frequency... from an audible frequency band to an inaudible frequency band" ('505 Patent, col. 2:12-14). Defendant may argue this stated purpose limits the term to structures that solve the problem of audible noise, not those that merely tune an ultrasonic frequency.
'697 Patent: "vibration region"
- Context and Importance: The relative thickness of the "vibration region" is the key limitation in asserted claim 10. The definition of this term is therefore essential for determining whether the accused sensor infringes.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term could be construed broadly to mean any part of the piezoelectric plate that vibrates to produce sound. The patent describes the outer portion vibrating in response to strain in the central portion, suggesting a functional relationship ('697 Patent, col. 5:31-36).
- Evidence for a Narrower Interpretation: Dependent claim 11, which is not asserted, specifies that "the vibration region is formed at an outer portion of the piezoelectric strain region" ('697 Patent, col. 10:28-30). Parties may dispute whether this language from a dependent claim should be used to narrow the scope of the term in the independent claim to only the outer periphery of the plate.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement for both patents. The factual basis cited is Defendant's advertising, publication of specifications, and distribution of user manuals, which allegedly encourage and provide instructions for customers to incorporate the accused sensors into infringing end products (Compl. ¶¶34-35, 50-51).
- Willful Infringement: The complaint alleges that Defendants had actual knowledge of the patents "at least as of November 7, 2022," and in the alternative, that they were willfully blind to the infringement (Compl. ¶¶30, 33, 46, 49). The allegations appear to be based on pre-suit notice.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of functional scope: For the '505 Patent, can the term "resonance change unit," which the patent describes as a solution to audible noise, be construed to cover a structure within an ultrasonic sensor that tunes an already-inaudible frequency? This question combines claim construction with the functional context provided by the specification.
- A central dispute will be one of structural mapping: For the '697 Patent, does the accused sensor's physical structure align with the claimed architecture? Specifically, the court will need to determine whether the thinner outer area of the sensor’s piezoelectric plate constitutes a "vibration region" and the thicker central area a "piezoelectric strain region" as those terms are defined by the patent.
- A key evidentiary question will be the probative value of third-party analysis: The complaint relies heavily on SCM images and analysis attributed to a third party, "System Plus Consulting," to establish the internal structure of the accused device. The admissibility and weight of this evidence, and what discovery reveals about the actual operation of the accused structures, will likely be a significant factor in the litigation.