PTAB

IPR2020-00704

Satco Products Inc v. Seoul Viosys Co Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: AC-Driven Light Emitting Device with Multiple Phosphors
  • Brief Description: The ’331 patent relates to a light-emitting device for AC power operation, featuring an array of light-emitting cells connected in series on a single substrate. The device's purported invention is the use of a first phosphor and a second phosphor with different decay times to convert light from an LED chip.

3. Grounds for Unpatentability

Ground 1: Obviousness over Martin, Uang/Masatoshi, and Setlur - Claims 1-7 and 10-11 are obvious over Martin-970 in view of Uang-971 and/or Masatoshi, and further in view of Setlur-036.

  • Prior Art Relied Upon: Martin-970 (Application # 2004/0206970), Uang-971 (Application # 2006/0138971), Masatoshi (Japanese Application # H5-198843), and Setlur-036 (International Publication No. WO 2005/083036).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Martin-970 taught the foundational elements of claim 1, including a monolithic array of LEDs on a single substrate with an integrated bridge rectifier for direct AC operation. However, Martin-970’s rectifier used non-light-emitting diodes. Uang-971 and Masatoshi taught improving such circuits by using light-emitting diodes in the branches of the bridge rectifier, increasing efficiency and light output. For the phosphor limitations, Petitioner argued that Martin-970 disclosed using multiple phosphors (e.g., red and green) to create white light but failed to address the known problem of phosphor saturation. Setlur-036 directly solved this saturation problem by teaching the use of two types of phosphors arranged based on their decay times: a fast-decay phosphor (≤1ms) placed near the LED chip where incident flux is high, and a slow-decay phosphor (>3ms) placed further away. Petitioner mapped the claimed “second phosphor” (the one without a specified decay time relative to the other) to Setlur's fast-decay phosphor and the claimed “first phosphor” (with the “longer decay time”) to Setlur’s slow-decay phosphor.
    • Motivation to Combine: A POSITA would combine Martin-970 with Uang-971 or Masatoshi to improve device efficiency and lower costs by replacing the non-emitting diodes in the rectifier with LEDs, which was a known and predictable design choice. A POSITA would then be motivated to incorporate the teachings of Setlur-036 into the improved Martin-970 device to solve the well-known problem of phosphor saturation. Setlur-036 provided an explicit solution for improving lamp efficiency and color stability by arranging phosphors according to their decay times, directly addressing a known deficiency in devices like Martin-970.
    • Expectation of Success: Petitioner asserted a POSITA would have a high expectation of success. Combining the circuits merely required making basic electrical connections between known components. Implementing Setlur’s teachings involved the predictable step of selecting known phosphors with desired decay times and arranging them in a known manner to achieve the expected benefit of reduced saturation.

Ground 2: Anticipation and Obviousness over Nagai - Claim 11 is anticipated by, or in the alternative, obvious over Nagai-654.

  • Prior Art Relied Upon: Nagai-654 (International Publication No. WO 2005/022654).
  • Core Argument for this Ground:
    • Prior Art Mapping (Anticipation): Petitioner argued that Nagai-654, a single reference, disclosed every limitation of claim 11. Nagai-654 taught an LED array chip with light-emitting cells connected in a series-parallel configuration. It also disclosed a transparent phosphor film that covered the LEDs to produce white light. This film explicitly contained a mixture of four different colored phosphors: blue, green, yellow, and red. Petitioner contended that Nagai-654’s list of exemplary phosphor compositions for this mixture inherently disclosed the claimed decay time relationship. Specifically, Nagai-654 disclosed using a green BaMgAl10O17:Eu2+Mn2+ (BAMN) phosphor, which was known to be a "slow decay" phosphor with a decay time of approximately 10 ms. The same list included multiple other phosphors (e.g., Eu2+ or Eu3+ based) known to have much faster decay times. Because Nagai-654 required using a combination of these phosphors, Petitioner argued it necessarily disclosed a combination wherein one phosphor (BAMN) had a longer decay time than another, thus anticipating the claim.
    • Core Argument (Obviousness): In the alternative, if the Board found Nagai-654’s disclosure was not specific enough to anticipate, Petitioner argued claim 11 was obvious over Nagai-654. A POSITA reading Nagai-654 would be directed to use a combination of the phosphors from the provided list. A POSITA would have known the general decay properties of these common phosphors and would have reasonably expected that selecting a known slow-decay phosphor (like BAMN) and a known fast-decay phosphor from Nagai-654's finite list would result in a device with the claimed properties. This selection was merely the use of known materials for their known properties to achieve a predictable result.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-7 and 10-11 of Patent 8,860,331 as unpatentable.