DCT

3:25-cv-02665

Semisilicon Technology Corp v. Changzhou Jutai Electronic Co Ltd

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I. Executive Summary and Procedural Information

Case Timeline

Date Event
2014-10-22 Earliest Priority Date for ’935 Patent
2017-03-10 Earliest Priority Date for ’117 Patent
2018-04-10 ’117 Patent Issued
2019-01-22 ’935 Patent Issued
2024-12-XX Alleged Notice of Infringement Sent to Defendants
2025-03-19 Complaint Filing Date

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

U.S. Patent No. 10,187,935 - Light Emitting Diode Lamp with Burnable Function and Light Emitting Diode Lamp String with Burnable Function (Issued: Jan. 22, 2019)

The Invention Explained

  • Problem Addressed: The patent identifies the inconvenience and potential for error when LED driver integrated circuits (ICs) must have their unique "local address" data programmed at the time of the IC’s manufacture, before being assembled into a final product like a light string (’935 Patent, col. 2:4-15).
  • The Patented Solution: The invention proposes an LED driving apparatus with a "burnable function" that allows a unique local address to be written (or "burned") into the device after it has been manufactured and assembled (’935 Patent, col. 2:26-34). The apparatus is designed to receive a special "burn start signal" and "burn address data" through its electrical contacts, which triggers the permanent storage of the new address. Subsequently, the device will respond only to lighting commands that are sent to that specific address (’935 Patent, col. 2:34-49).
  • Technical Importance: This post-assembly addressing capability simplifies inventory management and the manufacturing process for complex, individually addressable electronic systems (’935 Patent, col. 2:8-15).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶29).
  • Essential elements of Claim 1:
    • An LED and an electrically connected "light emitting diode driving apparatus with the burnable function."
    • The apparatus has a first and second contact.
    • The apparatus receives a "burn start signal" and "burn address data" through the first contact.
    • The apparatus is configured to "burn the burn address data as a local address data" after receiving the burn start signal.
    • The apparatus later receives a "first signal" (comprising lighting and address data) and compares the signal's address data with its stored local address data.
    • The apparatus drives the LED to light based on the signal's lighting data only if the addresses match.
  • The complaint reserves the right to assert additional claims.

U.S. Patent No. 9,939,117 - Light Emitting Diode System With Light Signals Carried Via Power Lines (Issued: Apr. 10, 2018)

The Invention Explained

  • Problem Addressed: The patent seeks to reduce the cost associated with adding a separate signal generation circuit to create and transmit control signals along the power lines of an LED lamp string (’117 Patent, col. 1:24-30).
  • The Patented Solution: The invention describes a system where a control unit is connected to a "signal voltage unit" (e.g., a MOSFET transistor). The control unit drives the signal voltage unit to "adjust a voltage of the light emitting diode lamp string continuously and repeatedly" to a "predetermined voltage" (’117 Patent, Abstract). This modulation of the power line voltage itself creates a "light signal" comprised of pulse waves, which is then decoded by each individual LED unit to determine the appropriate lighting mode (e.g., color, blinking pattern) (’117 Patent, col. 2:48-58).
  • Technical Importance: By generating control signals through the manipulation of the main power supply voltage, the system aims to eliminate the need for separate signal wiring or more complex circuitry, thereby reducing overall system cost (’117 Patent, col. 2:59-62).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶42).
  • Essential elements of Claim 1:
    • An LED lamp string with multiple LED units powered by power lines.
    • A "signal voltage unit" electrically connected to the lamp string.
    • A "control unit" electrically connected to the signal voltage unit.
    • The control unit is configured to drive the signal voltage unit to "adjust a voltage of the light emitting diode lamp string continuously and repeatedly" to form a "light signal" made of pulse waves.
    • Each LED unit is configured to receive the signal, perform "a conversion and a decoding" to obtain a lighting mode, and light up based on that mode.
  • The complaint reserves the right to assert additional claims.

III. The Accused Instrumentality

Product Identification

  • The complaint identifies decorative LED light strings sold on Amazon.com, including the "YIQU Color Changing Smart Christmas Lights" (ASIN B0D7MCYJ9H) and the "BHCLIGHT Smart DIY Color Changing Christmas Lights" (ASIN B0D7PTZGTB) (Compl. ¶¶30, 43). Defendant Changzhou Jutai Electronic Co., Ltd. is alleged to be the manufacturer of the accused products (Compl. ¶22).

Functionality and Market Context

  • The accused products are consumer-grade, multi-color LED light strings that operate via a power adapter and are controlled by a remote and/or smartphone application (Compl. ¶¶31, 44). The complaint alleges that defendant Jutai markets itself as "the preferred brand for Amazon e-commerce" for such lighting products (Compl. ¶21). The YIQU product is alleged to contain an LED driving IC with "address-recording fuses" for a "burnable function" (Compl. ¶32). The BHCLIGHT product is alleged to use a control IC and a MOSFET switch to generate signals by modulating the voltage on the power line (Compl. ¶¶45-46).

IV. Analysis of Infringement Allegations

’935 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a light emitting diode driving apparatus with the burnable function The YIQU product includes an LED driving IC that incorporates a plurality of address-recording fuses for the execution of the burnable function. An exemplary optical microscope image shows fuses on the IC labeled "Address recording fuses." (Compl. p. 10). ¶32 col. 3:45-48
receives a burn start signal ... and a burn address data The complaint alleges the LED control IC receives a burn start signal and burn address data to record the address by blowing specific fuses. ¶34 col. 3:51-54
is configured to burn the burn address data as a local address data The LED control IC records the burn address data as local address data by blowing one or more specific fuses within a selected fuse block. An annotated diagram shows a reverse analysis of the fuse block. (Compl. p. 12). ¶34 col. 3:55-59
a first signal is a plurality of pulse signals, and comprises a lighting data and an address data The controller transmits a series of pulse signals containing address and lighting data to control the LEDs. ¶35 col. 4:40-42
is configured to compare the address data with the local address data Each LED lamp receives the signals and lights up if the transmitted address data matches its local address data. ¶35 col. 4:41-44
drive the light emitting diode to light ... based on the lighting data if the address data is the same with the local address data LEDs at different addresses in the string light up in red when their local address data match the transmitted address data in the signals. ¶35 col. 4:48-52
  • Identified Points of Contention:
    • Technical Questions: A primary question will be evidentiary: what proof demonstrates that the accused YIQU product's "address-recording fuses" are programmed by receiving a "burn start signal" and "burn address data" after manufacturing, as required by the claim? The complaint shows the existence of fuses (Compl. p. 10) but the mechanism and timing of their programming (i.e., in-field vs. at the factory) may be a central point of dispute.
    • Scope Questions: The interpretation of "burnable function" will be critical. The defense may argue that this term, in the context of the patent, requires a specific field-programmable process initiated by an external signal, and that the accused product's use of fuses for what might be factory-set addressing does not meet this limitation.

’117 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a signal voltage unit electrically connected to the light emitting diode lamp string The BHCLIGHT controller includes an N-type MOSFET switch (Q1) that functions as a signal voltage unit, electrically connected to the LED lamp string through its source. ¶45 col. 2:42-44
a control unit electrically connected to the signal voltage unit The controller includes a control IC (PHY6252) that functions as a control unit, electrically connected to the MOSFET's gate. An annotated schematic shows the control IC and MOSFET connections. (Compl. p. 18). ¶45 col. 2:45-46
the control unit is configured to drive the signal voltage unit to adjust a voltage ... to form the light signal comprising a plurality of pulse waves The control IC continuously and repeatedly drives the MOSFET switch on and off to adjust the voltage supplied to the lamp string, generating a pulse wave pattern that forms the light signal. Oscilloscope photos are provided to show the resulting voltage changes. (Compl. p. 18). ¶46 col. 2:48-54
each ... light emitting diode units is configured to perform a conversion and a decoding for the light signal to obtain a lighting mode Each LED lamp in the string processes the received light signal, converting each pulse wave into a digital signal (0 or 1) based on pulse width, and decodes these signals to obtain the lighting mode (e.g., red, blue, or green). ¶47 col. 2:54-57
  • Identified Points of Contention:
    • Technical Questions: The complaint alleges the control IC drives the MOSFET to "toggle its status" (Compl. ¶46), which may be a standard pulse-width modulation (PWM) technique. The question for the court will be whether this operation is technically equivalent to the claimed method of adjusting the voltage "continuously and repeatedly" to a "predetermined voltage."
    • Scope Questions: The construction of "predetermined voltage" may be a key issue. The patent provides an example where voltage is adjusted from 110V down to 60V (’117 Patent, col. 5:11-14). The defense may argue this implies a specific analog-like voltage level adjustment, rather than the binary on/off switching characteristic of PWM, potentially creating a non-infringement argument.

V. Key Claim Terms for Construction

'935 Patent: "burn the burn address data as a local address data"

  • Context and Importance: This term is central to the invention's core concept of post-manufacturing programmability. The infringement analysis will depend on whether the accused product's method of setting an address, which allegedly involves blowing fuses, falls within the scope of "burning" as understood from the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that the word "burning" means "data writing" (’935 Patent, col. 3:49-50), which could support an interpretation that covers any method of permanently writing data to the device's memory.
    • Evidence for a Narrower Interpretation: The claim requires the "burning" to occur after the apparatus receives a "burn start signal." This, combined with the patent's focus on solving the problems of pre-manufacturing addressing (’935 Patent, col. 2:4-15), could support a narrower construction requiring a specific, post-assembly programming process initiated by an external command, not just a one-time factory configuration.

'117 Patent: "adjust a voltage ... continuously and repeatedly so the voltage ... is a predetermined voltage"

  • Context and Importance: This phrase defines the specific mechanism for creating the "light signal." Practitioners may focus on this term because standard PWM, a common technique, might not meet this definition, potentially creating a path to a non-infringement defense.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent's objective is to form a "plurality of pulse waves" (’117 Patent, col. 2:53), a general description that could plausibly encompass the output of a PWM-based system.
    • Evidence for a Narrower Interpretation: The specification provides a specific example where the voltage of the power output is "decreased as 60 volts" from an initial 110 volts (’117 Patent, col. 5:11-14). This suggests the "predetermined voltage" is a specific, non-zero voltage level, not merely the "off" state (0V) in a simple on/off PWM cycle.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement (Compl. ¶¶28, 41). The factual basis centers on the allegation that Defendant Jutai manufactures infringing products and supplies them to the other defendants, including Amazon, for sale in the U.S. (Compl. ¶¶22, 28). The complaint alleges Jutai identifies itself as "the preferred brand for Amazon e-commerce" (Compl. ¶21).
  • Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge. It states that Semisilicon identified both the ’935 and ’117 patents to each defendant in a notice of infringement sent "as early as December, 2024" (Compl. ¶¶37, 49).

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

  1. A core issue will be one of evidentiary proof: Can the plaintiff demonstrate that the accused YIQU product's "address-recording fuses" are programmed post-assembly via an external "burn start signal" as required by the '935 patent, or will discovery show this is a mechanism for factory-level pre-programming that falls outside the claim scope?
  2. A second key issue will be one of claim construction: For the '117 patent, can the phrase "adjust a voltage... to a predetermined voltage" be construed to cover the accused BHCLIGHT product's alleged on/off toggling of a MOSFET switch, or does the patent’s language and specification require a more specific method of voltage modulation that the accused product does not perform?
  3. Finally, a central question of liability will be whether the alleged December 2024 notice of infringement is sufficient to establish the requisite knowledge and intent for willful and indirect infringement across a multi-party supply chain that includes a foreign manufacturer, multiple third-party sellers, and an online retail platform.