PTAB

IPR2025-00258

Elong Intl USA Inc v. Feit Electric Co Inc

Key Events

Petition

petition

Case #: IPR2025-00258
Patent #: 8,604,678
Filed: December 9, 2024
Petitioner(s): Elong International USA Inc., and Xiamen Longstar Lighting Co. Ltd.
Patent Owner(s): Feit Electric Company, Inc.
Challenged Claims: 1-3, 6, 7, 9, 10, 16-21, 25, 26, and 29

Title: Wavelength Conversion Component with a Diffusing Layer
Brief Description: The ’678 patent describes a wavelength conversion component for white-light LED devices. The invention adds a light diffusing outer layer containing scattering particles, such as titanium dioxide (TiO2), to a phosphor-based conversion layer to improve the device’s appearance from yellow to white when it is in an off-state.

Prior Art Relied Upon: Basin-2007 (Application # US2009/0057699) and Basin-2005 (Application # US2007/0045761).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Basin-2007, titled “LED with Particles in Encapsulant for Increased Light Extraction and Non-Yellow Off-State Color,” discloses all limitations of independent claim 1 except for the specific blue light wavelength. Basin-2007 explicitly teaches a wavelength conversion layer (YAG phosphor) and an overlying light diffusing layer (silicone encapsulant with TiO2 particles) to make the LED appear whiter in its off-state.
- Motivation to Combine: Basin-2007 discloses its improvements are for a “conventional white light LED” that generates blue light. Petitioner asserted a POSITA would look to Basin-2005 for details of such a conventional LED, as it discloses a structurally similar device. Basin-2005 explicitly teaches that its blue LEDs emit light in a range (420-490 nm) that satisfies the challenged claims’ requirement of greater than or equal to 440 nm.
- Expectation of Success: A POSITA would have had an expectation of success because the combination involves the simple substitution of a known, conventional blue-light LED (from Basin-2005) into the device of Basin-2007 to achieve predictable results.

Prior Art Relied Upon: Hussell (Application # US2010/0124243), Basin-2007 (Application # US2009/0057699), and Van Woudenberg (WO 2008/044171).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner contended that Hussell discloses a light bulb structure with LED “filaments” that function as wavelength conversion components, meeting the structural limitations of claims 19, 20, and 29. However, Hussell’s YAG phosphor filaments would appear yellow in the off-state, and Hussell does not explicitly teach a light diffusing layer to improve this appearance or the specific blue light wavelength.
- Motivation to Combine: A POSITA would be motivated to solve the known problem of the undesirable yellow off-state appearance of Hussell’s YAG phosphor filaments. Van Woudenberg established that this yellowish appearance is a “disturbing feature” in general lighting applications like light bulbs. A POSITA would combine Hussell with the explicit solution taught in Basin-2007: adding a light diffusing layer with scattering particles (TiO2). Further, a POSITA would use a blue LED emitting light in the 430-480 nm range as taught by Van Woudenberg, which is standard for creating white light.
- Expectation of Success: A POSITA would expect success in applying the silicone-based diffusing layer from Basin-2007 as a coating onto the exterior of Hussell’s wavelength conversion tube, as this is a straightforward modification to achieve a known benefit.

Prior Art Relied Upon: Krummacher (Application # US2008/0079015), Shimizu (Patent 6,069,440), and Stokes (Patent 6,791,259).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Krummacher discloses all elements of the challenged claims except the specific blue light wavelength. Krummacher teaches an optoelectronic component with a luminescence conversion layer followed by a light-scattering translucent layer (containing TiO2) to solve the problem of the "unattractive" yellow color of the component in its off-state.
- Motivation to Combine: Krummacher’s device uses a blue-light emitting semiconductor chip. Petitioner asserted a POSITA would look to well-known references like Shimizu and Stokes for details of a conventional blue-light LED chip. Both Shimizu and Stokes disclose white-light LED sources using blue LEDs with emission peaks squarely within the claimed range (e.g., 450 nm and 480 nm).
- Expectation of Success: A POSITA would have expected success in using the conventional blue LED chips disclosed in Shimizu and Stokes within the Krummacher device, as it represents a simple substitution of one known element for another to obtain a predictable outcome.
Additional Grounds: Petitioner asserted an additional obviousness challenge for claims 19, 20, and 29 based on Hussell, Krummacher, and Van Woudenberg, which substitutes Krummacher for Basin-2007 from Ground 2 to provide the teachings of a light-diffusing layer.

Petitioner argued that discretionary denial under 35 U.S.C. §325(d) is unwarranted because none of the asserted prior art references (Basin-2007, Basin-2005, Krummacher, Hussell, or Stokes) were before the Examiner during the original prosecution. Petitioner contended that the Examiner allowed the claims based on the mistaken belief that using a light diffusing layer to improve off-state white appearance was new for blue-light LEDs, a notion directly refuted by the asserted art.

Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 6, 7, 9, 10, 16-21, 25, 26, and 29 of the ’678 patent as unpatentable.