LS Cable & System Ltd v. Apple Inc

I. Executive Summary and Procedural Information

LS Cable & System Ltd. v. Apple Inc.

• Parties & Counsel:
  • Plaintiff: LS Cable & System Ltd. (Republic of Korea)
  • Defendant: Apple Inc. (California)
  • Plaintiff’s Counsel: K&L Gates LLP
• Case Identification: 3:24-cv-09194, N.D. Cal., 12/18/2024
• Venue Allegations: Venue is alleged to be proper in the Northern District of California because Defendant Apple Inc. is incorporated in California and maintains a regular and established place of business in the district.
• Core Dispute: Plaintiff alleges that Defendant’s iPhone, Apple Watch, and AirPods product lines, which feature wireless charging capabilities, infringe a patent related to controlling power transfer in wireless charging systems.
• Technical Context: The technology concerns methods for preventing overvoltage and damage in wireless charging systems by having the receiving device monitor its charging state and wirelessly communicate with the charging pad to adjust power levels.
• Key Procedural History: The asserted patent, U.S. Patent No. 8,013,568, was the subject of a supplemental examination requested by the patent owner in March 2021. In September 2023, the USPTO issued a Reexamination Certificate, which confirmed the patentability of several claims as amended, including the asserted independent claim. This procedural history suggests the patent has been scrutinized by the USPTO post-issuance, a factor that may be relevant to future validity challenges.

Case Timeline

Date	Event
2005-07-29	’568 Patent Priority Date
2011-09-06	’568 Patent Issue Date
2017-01-01	Approximate date Apple entered the wireless charging market
2019-03-01	Approximate date LS Cable first notified Apple of infringement
2020-01-01	Approximate date LS Cable provided Apple a claim chart
2021-03-12	LS Cable requested supplemental examination of the ’568 Patent
2023-09-28	USPTO issued Reexamination Certificate for the ’568 Patent
2024-12-18	Complaint Filing Date

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

U.S. Patent No. 8,013,568 - "Contact-Less Chargeable Battery and Charging Device, Battery Charging Set, and Charging Control Method Thereof"

• Patent Identification: U.S. Patent No. 8,013,568, "Contact-Less Chargeable Battery and Charging Device, Battery Charging Set, and Charging Control Method Thereof," issued September 6, 2011. A Reexamination Certificate (US 8,013,568 C1) was issued on September 28, 2023.

The Invention Explained

• Problem Addressed: Conventional wireless charging systems faced a problem where misalignment between the charging pad and the device could lead to an "unexpected overvoltage" being applied to the device's battery charging circuits, potentially causing damage ('568 Patent, col. 3:5-12). Fixing the device in a precise position to avoid this was inconvenient for the user ('568 Patent, col. 3:13-21).
• The Patented Solution: The invention describes a "contact-less chargeable battery" that actively manages the charging process. The battery's internal circuitry monitors the voltages being supplied to it. If it detects a potential overvoltage condition, it wirelessly transmits a "monitoring result" back to the charging device, which then adjusts the power of its magnetic field to an appropriate level ('568 Patent, col. 4:26-38). This feedback loop allows for more flexible placement of the device on the charger while preventing electrical damage ('568 Patent, col. 10:28-44).
• Technical Importance: This technology aims to improve the safety, reliability, and user-friendliness of inductive wireless charging by creating an intelligent, closed-loop power control system between the charger and the device being charged.

Key Claims at a Glance

• The complaint asserts at least independent claim 7, as amended by the Reexamination Certificate (Compl. ¶41).
• Amended Independent Claim 7 includes these essential elements:
  • A "high frequency AC current inducing unit" (e.g., a secondary coil) that receives power from a magnetic field.
  • A "rectifier" to convert the induced AC current to DC current.
  • A "constant voltage/constant current supplier" that receives the DC current and supplies charging power to a battery cell.
  • A "microprocessor" that monitors voltages at both ends of the constant voltage/constant current supplier.
  • The microprocessor "wirelessly transmitt[s] a monitoring result to the external contact-less charging device... so as to induce a change of intensity of the magnetic field."
  • A final clause specifies that "the change of intensity of the magnetic field is based on relative positions of the contact-less charging circuit module and the external contact-less charging device."
• The complaint reserves the right to assert other claims (Compl. ¶42).

III. The Accused Instrumentality

Product Identification

• The complaint identifies three categories of accused products: "the iPhone Devices," "the Apple Watch Devices," and "the Apple AirPods Devices" (Compl. ¶32). This includes numerous models from the iPhone 8 to the iPhone 16, all Apple Watch series, and various AirPods models (Compl. ¶¶ 26-28).

Functionality and Market Context

• The accused functionality is the products' capability for wireless charging, which the complaint alleges complies with the Wireless Power Consortium's Qi Standard (Compl. ¶25).
• The complaint alleges these products utilize wireless charging chips from suppliers such as Broadcom and IDT (via its P9022 chip) to implement this functionality (Compl. ¶¶ 26-27). The complaint includes a photograph of a thin wireless charging module developed by LS Cable to illustrate its own history and innovation in this technological space (Compl. ¶13). This visual shows a flat, flexible circuit with a prominent copper coil, representing the type of component central to the dispute.

IV. Analysis of Infringement Allegations

The complaint alleges that the Accused Products directly infringe at least claim 7 of the ’568 Patent (Compl. ¶41). It states that a non-limiting claim chart was provided as Exhibit 4; however, this exhibit was not included with the filed complaint document.

The complaint’s narrative infringement theory is that by including wireless charging chips and complying with the Qi Standard, the Accused Products necessarily practice the patented method of monitoring and controlling charging power (Compl. ¶¶ 25-26, 29-31). The complaint does not, in its narrative body, provide a detailed, element-by-element mapping of how the accused Qi-compliant functionality meets the specific limitations of amended claim 7. The detailed basis for this allegation is deferred to the missing exhibit.

• Identified Points of Contention:
  • Technical Question: A primary evidentiary question will be whether the operation of the Qi standard, as implemented in Apple’s products, performs the specific functions required by the asserted claim. For example, discovery will likely focus on whether the Accused Products’ microprocessors in fact "monitor[] voltages at both ends of the constant voltage/constant current supplier" and transmit a "monitoring result" for the purpose of adjusting power based on that specific internal measurement, as the claim requires.
  • Scope Question: The final clause of amended claim 7 states that the "change of intensity of the magnetic field is based on relative positions" of the charger and the device. This raises the question of whether the claim is limited to systems that adjust power solely to compensate for positional changes, or if it more broadly covers systems where positional-awareness is one aspect of a larger power management protocol like the Qi standard.

V. Key Claim Terms for Construction

• The Term: "microprocessor monitoring voltages at both ends of the constant voltage/constant current supplier"

• Context and Importance: This term is central to the invention's feedback mechanism. The definition of how and what is "monitored" will be critical to infringement. Practitioners may focus on this term because the complaint's theory relies on the inherent functionality of the Qi standard, and the defense will likely scrutinize whether Qi communication protocols are equivalent to the specific monitoring function described in the patent.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself does not specify the precise method of monitoring, which could support a construction that covers any method of assessing the voltage differential across the power supply circuit.
  • Evidence for a Narrower Interpretation: The specification's primary embodiment discloses a specific architecture with a "first voltage detector" (350) and a "second voltage detector" (360) whose outputs are compared ('568 Patent, col. 8:33-41, Fig. 5). A party could argue that "monitoring voltages at both ends" should be construed to require this two-detector structure or a direct equivalent, rather than a more general power-level communication.

• The Term: "wherein the change of intensity of the magnetic field is based on relative positions of the contact-less charging circuit module and the external contact-less charging device"

• Context and Importance: This "wherein" clause was added during reexamination and appears to tie the claimed power adjustment to the physical positioning of the device. Its interpretation could be dispositive. The core dispute may turn on whether this clause describes the purpose of the invention (to solve the misalignment problem) or imposes a strict functional limitation on the accused system's operation.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party might argue this clause merely sets the context for the invention, which is to enable position-agnostic charging, and does not require that the system only function in response to positional changes. The patent describes the problem as overvoltage caused by misalignment, suggesting this is the problem being solved ('568 Patent, col. 2:33-54).
  • Evidence for a Narrower Interpretation: As a limitation added to secure patentability during reexamination, it may be construed more narrowly. A party could argue that for infringement, the power adjustment must be a direct and intended consequence of detecting a change in "relative positions," potentially distinguishing it from general thermal or battery-level management protocols within the Qi standard.

VI. Other Allegations

• Indirect Infringement: The complaint alleges Apple induces infringement by providing the Accused Products to users with instructions on how to use the wireless charging feature in a manner that Apple allegedly knew would infringe (Compl. ¶45). Knowledge is alleged to date back to at least March 2019, when LS Cable first sent a notice letter to Apple (Compl. ¶46).
• Willful Infringement: Willfulness is alleged based on Apple’s "full, express, and actual knowledge" of the ’568 Patent since at least September 28, 2023—the date the USPTO issued the Reexamination Certificate confirming the patentability of the amended claims (Compl. ¶50). This suggests a theory that any infringement after the USPTO's affirmation of the patent's validity is necessarily deliberate and willful.

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

1. A central issue will be one of claim scope: How will the court construe the reexamined claim 7 limitation "wherein the change of intensity of the magnetic field is based on relative positions"? The case may turn on whether this is interpreted as merely stating the technical context for the invention (solving misalignment) or as a functional requirement that the accused power adjustment must be directly tied to detecting positional changes.
2. A key evidentiary question will be one of technical mapping: Can LS Cable demonstrate that the standard operations of the Qi protocol, as implemented in Apple's products, meet the specific claim requirement of a microprocessor "monitoring voltages at both ends of the constant voltage/constant current supplier" and transmitting a result based on that monitoring? The complaint's reliance on Qi-compliance without detailed technical mapping makes this the central battleground for infringement discovery.