DCT

4:25-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 U.S. Patent No. 10,187,935
2017-03-10 Earliest Priority Date for U.S. Patent No. 9,939,117
2018-04-10 U.S. Patent No. 9,939,117 Issued
2019-01-22 U.S. Patent No. 10,187,935 Issued
2024-12-01 Alleged Notice of Infringement Sent to Defendants
2025-03-19 Complaint Filed

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

The Invention Explained

  • Problem Addressed: The patent describes the inconvenience and potential for error when LED driving apparatuses must have their local addresses programmed before they are manufactured and assembled into a light string, which complicates warehouse management and assembly. (’935 Patent, col. 2:4-15).
  • The Patented Solution: The invention is an LED lamp with a "burnable function," allowing a unique "local address data" to be written ("burned") into the lamp's driving apparatus after it has been manufactured. This is accomplished by sending a "burn start signal" and "burn address data" through the lamp's contacts, enabling post-assembly programming. (’935 Patent, Abstract; col. 2:26-38). The system then uses pulse signals carrying both address and lighting data to control individual lamps. (’935 Patent, col. 2:38-48).
  • Technical Importance: This method of in-system, post-manufacturing programming simplifies the production and installation of complex, individually addressable LED lighting systems. (’935 Patent, col. 2:6-15).

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶28).
  • The essential elements of claim 1 include:
    • An LED lamp comprising an LED and an LED driving apparatus with a "burnable function."
    • The driving apparatus has a first and second contact.
    • The driving apparatus is configured to receive a "burn start signal" and "burn address data" through the first contact.
    • The driving apparatus is configured to "burn the burn address data as a local address data" into itself after receiving the burn start signal.
    • The driving apparatus later receives a "first signal" (a plurality of pulse signals with lighting and address data) and compares the signal's address data with its stored local address data.
    • The driving apparatus drives the LED based on the lighting data if the addresses match.
  • The complaint reserves the right to assert additional claims. (Compl. ¶28).

U.S. Patent No. 9,939,117 - Light Emitting Diode System With Light Signals Carried Via Power Lines

The Invention Explained

  • Problem Addressed: The patent seeks to reduce the cost associated with adding a separate circuit to generate and transmit control signals to LED lamps in a string. (’117 Patent, col. 1:24-30).
  • The Patented Solution: The patented system uses a "control unit" to drive a "signal voltage unit", which in turn modulates the voltage on the power lines themselves to create a "light signal" composed of pulse waves. (’117 Patent, Abstract). Each LED unit on the string receives these power-line-carried pulses, decodes them to determine the intended lighting mode, and illuminates accordingly, thereby eliminating the need for separate data wires. (’117 Patent, col. 2:51-57; FIG. 1).
  • Technical Importance: This architecture simplifies the design and lowers the cost of smart LED systems by using the existing power infrastructure for both power delivery and data communication. (’117 Patent, col. 2:58-61).

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶41).
  • The essential elements of claim 1 include:
    • An LED system with an LED lamp string that receives power through 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 light signal, perform a "conversion and a decoding" to obtain a lighting mode, and then light up based on that mode.
  • The complaint reserves the right to assert additional claims. (Compl. ¶41).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies several decorative LED light string products, focusing on the "YIQU Color Changing Smart Christmas Lights" (accused of infringing the ’935 Patent) and the "BHCLIGHT Smart DIY Color Changing Christmas Lights" (accused of infringing the ’117 Patent). (Compl. ¶¶30, 43). Defendant Jutai is alleged to be the manufacturer of the accused products. (Compl. ¶¶21, 28).

Functionality and Market Context

  • The accused products are app- and remote-controlled decorative light strings capable of producing numerous lighting patterns and colors. (Compl. p. 8, 16). The complaint alleges that the YIQU product contains an LED driving IC with "address-recording fuses" for a "burnable function." (Compl. ¶¶32, 34). The complaint includes an annotated optical microscope image of the accused YIQU product's LED driving IC, showing areas labeled "Address recording fuses" and "Blown fuse." (Compl. p. 10). For the BHCLIGHT product, the complaint alleges it uses a control IC to drive a MOSFET switch, thereby adjusting the voltage on the power line to create a signal of pulse waves that controls the LEDs. (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
receives a burn start signal sent through the first contact and a burn address data sent through the first contact The complaint alleges that upon receiving a burn start signal and burn address data, the accused product's LED control IC acts to record the data. (Compl. ¶34). The complaint provides an optical microscope image of the accused LED lamp with the lens removed. (Compl. p. 11). ¶34 col. 8:52-54
configured to burn the burn address data as a local address data into the light emitting diode driving apparatus after the light emitting diode driving apparatus receives the burn start signal The accused product's LED driving IC allegedly "incorporates a plurality of address-recording fuses for the execution of the burnable function" and records the address data "by blowing one or more specific fuses." (Compl. ¶¶32, 34). ¶¶32, 34 col. 8:55-59
a first signal is a plurality of pulse signals, and comprises a lighting data and an address data The controller allegedly "transmits a series of pulse signals to control the lighting of the LEDs," with the signals containing both address data and lighting data. (Compl. ¶35). The complaint includes oscilloscope photographs showing these alleged pulse signals. (Compl. p. 13). ¶35 col. 8:60-62
configured to compare the address data with the local address data stored... and then... drive the light emitting diode to light... based on the lighting data if the address data is the same with the local address data It is alleged that each LED lamp in the accused product "receives these signals and lights up if the address data matches its local address data." (Compl. ¶35). ¶35 col. 8:62-col.9:12
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the signals allegedly received by the accused IC meet the specific definitions of "burn start signal" and "burn address data" as contemplated by the patent, or if they are merely part of a conventional factory initialization process.
    • Technical Questions: The case may turn on evidence demonstrating that the alleged "blowing" of fuses in the accused IC is functionally equivalent to the "burning" of a local address as described in the patent specification.

’117 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a control unit electrically connected to the signal voltage unit The accused product's controller allegedly includes a "control IC as a control unit" and an "N-type MOSFET switch Q1 as a signal voltage unit," which are electrically connected. (Compl. ¶45). The complaint provides a circuit diagram of the accused controller. (Compl. p. 18). ¶45 col. 12:44-45
the control unit is configured to drive the signal voltage unit to adjust a voltage... continuously and repeatedly... to form the light signal comprising a plurality of pulse waves The accused control IC allegedly "continuously and repeatedly drives the MOSFET switch... to toggle its status, turning on and off to adjust the voltage... to generate a plus wave pattern to form the light signal." (Compl. ¶46). ¶46 col. 12:45-51
each of the light emitting diode units is configured to perform a conversion and a decoding for the light signal to obtain a lighting mode It is alleged that each accused LED lamp "converts each received pulse wave... into a representation of a digital signal... based on its respective pulse width, and decodes these digital signals to obtain the lighting mode." (Compl. ¶47). ¶47 col. 12:52-56
  • Identified Points of Contention:
    • Scope Questions: A likely point of dispute will be the construction of "adjust a voltage... continuously and repeatedly." The defense may argue that the accused product's alleged binary toggling of a MOSFET switch between 'on' (e.g., 30V) and 'off' (e.g., 0V) does not constitute the "adjustment" required by the claim.
    • Technical Questions: Evidence will be needed to establish how the accused LED units perform "conversion and a decoding" based on pulse width, as alleged in the complaint, and whether this mechanism matches the teachings of the patent.

V. Key Claim Terms for Construction

For the ’935 Patent

  • The Term: "burn the burn address data" (Claim 1)
  • Context and Importance: This term is central to the novelty of the patent. The infringement case hinges on whether the accused products' alleged action of blowing internal fuses to set an address constitutes "burning" as claimed. Practitioners may focus on this term because the patent's primary contribution is enabling this post-manufacturing programming.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that "the wording 'burning' means 'data writing'" (’935 Patent, col. 4:49-50), which could support an interpretation that any act of writing data to a persistent memory, including blowing fuses, falls within the claim scope.
    • Evidence for a Narrower Interpretation: The background focuses on solving the problem of pre-manufacturing address assignment for assembly convenience. (’935 Patent, col. 2:4-15). A defendant could argue that "burning" should be limited to a specific type of user- or assembler-initiated, field-programmable action, rather than a standard factory initialization procedure that happens to use fuses.

For the ’117 Patent

  • The Term: "adjust a voltage... continuously and repeatedly" (Claim 1)
  • Context and Importance: This term defines the mechanism for creating the claimed "light signal." The plaintiff's theory is that toggling a switch meets this limitation. The viability of the infringement claim depends on this interpretation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The stated purpose is to "form the light signal comprising a plurality of pulse waves." (’117 Patent, col. 12:50-51). This might support a view that any repeated voltage manipulation that successfully creates control pulses—including rapid on/off switching—satisfies the limitation.
    • Evidence for a Narrower Interpretation: The specification discusses changing the "conduction rate" of a transistor to "generate the light signal." (’117 Patent, col. 3:19-24). This language, combined with the word "continuously," could be argued to require a more nuanced, analog-style modulation of voltage, rather than a simple binary switching between two discrete voltage levels.

VI. Other Allegations

  • Indirect Infringement: The complaint makes boilerplate allegations of indirect infringement under 35 U.S.C. § 271(b) and (c), asserting that defendants offered for sale and sold products containing infringing components. (Compl. ¶¶28, 41). The factual support for inducement centers on the sale of products that are alleged to directly infringe.
  • Willful Infringement: The complaint alleges willful infringement for both patents. The factual basis for this allegation is Plaintiff's claim to have provided each defendant with "a notice of infringement" identifying the patents-in-suit "as early as December, 2024," several months prior to filing the complaint. (Compl. ¶¶37, 49).

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

  • A core issue will be one of process definition: Can the ’935 patent's claim to "burn... address data," which the specification frames as a solution to post-manufacturing assembly problems, be construed to cover the alleged factory-level process of blowing fuses inside the accused product's IC?
  • A key evidentiary question will be one of functional interpretation: Does the accused system's alleged toggling of a MOSFET switch between on and off states constitute an "adjust[ment of] a voltage... continuously and repeatedly" as required by claim 1 of the ’117 patent, or does the claim language necessitate a more granular form of voltage modulation?
  • A third question concerns knowledge and intent: Given the allegation of pre-suit notice in December 2024, the court will have to examine what knowledge the defendants possessed regarding the patents and when they possessed it, which will be central to the determination of willfulness.