PTAB

IPR2018-00523

Apple Inc v. Uniloc Luxembourg SA

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1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Controlling Battery Charge and Discharge Currents Based on Temperature
  • Brief Description: The ’203 patent discloses a system for managing rechargeable batteries, particularly for portable electronic devices. The system uses a temperature sensor and a controller to periodically check the battery's temperature and select an appropriate charging or discharging current from a memory look-up table, thereby operating the battery within safe temperature limits to prevent damage and degradation.

3. Grounds for Unpatentability

Ground 1: Obviousness over Koenck and Doi - Claims 1, 5-8, 15-16, 20-23, and 29 are obvious over Koenck in view of Doi.

  • Prior Art Relied Upon: Koenck (Patent 4,709,202) and Doi (Japanese Patent Application No. H11-283677).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Koenck discloses all primary elements of independent claims 1 and 8. Koenck’s portable battery conditioning system includes a controller (battery processor 82), a charging circuit (101), a temperature sensor (93), and a discharging circuit (110). Koenck’s controller receives temperature data and adjusts the charging rate, including "cutting off" charging at a high temperature threshold (70°C) to prevent damage. Petitioner contended that to the extent "cutting off" might be considered ambiguous, Doi provides an explicit mechanism for setting current to zero. Doi teaches using a charging stop FET and a discharge stop FET that are turned "OFF" to forcibly stop current flow upon detecting an abnormal heat condition, an action a person of ordinary skill in the art (POSITA) would understand as setting the current to zero.
    • Motivation to Combine: A POSITA would combine Koenck and Doi because both address the critical and well-known problem of managing battery temperature during operation. Petitioner asserted it would have been an obvious design choice to implement Doi’s explicit FET-based cut-off mechanism into Koenck's temperature-monitoring system. This combination of known elements would yield the predictable result of a more robust and reliable overheating protection mechanism. The motivation is strengthened by Doi’s own suggestion that its invention can be applied to NiCd batteries, the type used in Koenck's system.
    • Expectation of Success: Applying a known electronic switch (Doi's FET) to a known control system (Koenck's) to halt current based on a temperature signal was a straightforward engineering task for a POSITA with a high expectation of success in achieving a safer battery system.

Ground 2: Obviousness over Koenck, Doi, and Sakakibara - Claims 2-4, 9-10, 17-19, and 24-25 are obvious over Koenck in view of Doi, further in view of Sakakibara.

  • Prior Art Relied Upon: Koenck (Patent 4,709,202), Doi (Japanese Patent Application No. H11-283677), and Sakakibara (Patent 6,204,641).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground adds Sakakibara to the Koenck/Doi combination to teach limitations of key dependent claims. For claims 2, 3, 9, and 10 (and related method claims), Petitioner argued Sakakibara teaches a controller that "constantly changes" or periodically adjusts charging current, with one embodiment using intervals of 10 seconds or less, providing the basis for the "continuously" and "periodically" setting limitations. For claims 4 and 19, Petitioner asserted Sakakibara discloses a "current controlling map" stored in memory—a direct teaching of a look-up table that correlates temperature with an optimum charging current. Sakakibara’s controller accesses this map to set the current, directly reading on the claim limitations.
    • Motivation to Combine: A POSITA would have been motivated to incorporate Sakakibara’s techniques to improve the performance and precision of the Koenck/Doi system. Petitioner argued that replacing Koenck's less frequent control loop (e.g., a 5-second software loop) with Sakakibara's teaching of constant or rapid periodic adjustment would provide more accurate and responsive temperature control, a known goal in the art. Similarly, implementing Sakakibara's look-up table would be a well-known and efficient engineering solution to replace a slower, calculation-based approach, improving system speed and efficiency.
    • Expectation of Success: Combining these known techniques—more frequent control updates and the use of a look-up table for speed—was well within the skill of a POSITA and would predictably result in a more efficient and accurate battery charging system.

4. Key Claim Construction Positions

  • Petitioner proposed a construction for the term "maximum charging temperature" as used in claim 6. It argued that based on the patent’s specification (specifically Table 1, which associates specific current values with temperature ranges), a POSITA would understand this term to mean "the highest battery temperature at which the maximum specified charging current can be used." This is distinct from the absolute maximum temperature at which the battery can be charged at any (e.g., trickle) rate. This construction was central to mapping Koenck's disclosure, which teaches applying a maximum charge rate only within a specific temperature range (e.g., below 55°C), to the claim language.

5. Relief Requested

  • Petitioner requested institution of an inter partes review for claims 1-10, 15-25, and 29 of Patent 6,661,203 and cancellation of those claims as unpatentable under 35 U.S.C. §103.