Lite On Technology v. Darfon Electronics Corp

1. Case Identification

• Case #: IPR2018-01062
• Patent #: 6,860,612
• Filed: May 10, 2018
• Petitioner(s): Lite-On Technology Corporation
• Patent Owner(s): Darfon Electronics Corporation
• Challenged Claims: 1, 5, 9-12, 14, 15, 17, 18, 21, and 22

2. Patent Overview

• Title: Illuminated Keyboard Switch Structure
• Brief Description: The ’612 patent describes an illuminated keyboard where the backlight device is disposed beneath a "seat" layer of the key switch. This arrangement purports to be an improvement over conventional designs where the backlight was placed above the seat, between the seat and the keycap.

3. Grounds for Unpatentability

Ground 1: Obviousness over Chou and Parker - Claims 1, 5, 9-12, 14, 15, 17, 18, 21, and 22 are obvious over Chou in view of Parker.

• Prior Art Relied Upon: Chou (Patent 6,554,442) and Parker (Patent 5,895,115).
• Core Argument for this Ground: Petitioner argued that Chou teaches every limitation of the challenged claims except for the feature of "a plurality of reflective portions... disposed underneath the cap and spaced apart from each other on the same plane." This limitation was added during a prior ex parte reexamination to overcome Chou. Petitioner asserted that Parker, which was not considered during prosecution or reexamination, explicitly discloses this missing element, rendering the combination obvious.
  • Prior Art Mapping: Petitioner contended that Chou discloses the foundational keyboard structure, including a key switch with a seat, a connecting assembly, a cap, and a backlight device located beneath the seat to illuminate the keycap through holes in the seat. The petition argued that Parker, which relates to light-emitting panel assemblies for backlighting control buttons, teaches the missing element. Specifically, Parker discloses using a light-emitting panel with a "plurality of reflective portions" (described as "light extracting deformities or disruptions") in the form of dots or other patterns on the same plane, disposed underneath control buttons to enhance and distribute illumination. Combining Parker's light panel with Chou's keyboard structure would result in the claimed invention.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Chou and Parker because both references address the same problem of improving the illumination of key buttons to help users locate them. Parker expressly teaches using its plurality of reflective portions to increase light output. Therefore, a POSA seeking to improve the illumination of Chou’s keyboard would have looked to known techniques like those in Parker and incorporated its light panel with reflective portions. The combination was presented as a simple substitution of one known lighting element (Chou's) for another improved one (Parker's) to achieve the predictable result of better illumination.
  • Expectation of Success: A POSA would have had a high expectation of success because the combination involved applying a known illumination-enhancement technique from Parker to a standard keyboard structure from Chou, with no apparent technical hurdles.

Ground 2: Obviousness over Chou and Nousiainen - Claims 1, 5, and 9 are obvious over Chou in view of Nousiainen.

• Prior Art Relied Upon: Chou (Patent 6,554,442) and Nousiainen (Patent 6,874,926).
• Core Argument for this Ground: This ground presented an alternative combination to supply the missing "plurality of reflective portions" limitation. Similar to the argument involving Parker, Petitioner asserted that Chou provides the base keyboard structure, while Nousiainen—another reference not previously considered by the Patent Office—teaches the use of multiple reflective portions under keys for illumination.
  • Prior Art Mapping: As in Ground 1, Chou was relied upon for its disclosure of an illuminated keyboard with a backlight beneath the seat. Nousiainen, which describes an illumination system for a mobile terminal, was cited for teaching a light-guiding section with a "plurality of reflective portions" or surfaces located underneath key buttons. These reflective surfaces are explicitly described as reflecting light toward the key locations. Petitioner argued that replacing Chou's lighting element with Nousiainen's light guide, which includes the claimed reflective portions, would result in the structure of claim 1.
  • Motivation to Combine: The motivation to combine Chou and Nousiainen was argued to be the same as for Parker. Both references are in the same field of illuminating keypads and share the common goal of increasing key brightness and distribution. A POSA would have been motivated to incorporate Nousiainen's method of using multiple reflective surfaces to improve the light distribution and intensity in Chou's keyboard design.
  • Expectation of Success: Success was expected because it involved the straightforward application of a known illumination technology from Nousiainen to the conventional keyboard layout disclosed in Chou.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate. Although the primary reference, Chou, was considered during a prior ex parte reexamination, the petition asserted that the specific combinations of Chou with Parker and Chou with Nousiainen were never presented to or considered by the PTO. Petitioner emphasized that Parker and Nousiainen are substantively different from the art previously considered because they explicitly teach the very limitation—"a plurality of reflective portions"—that was found missing in Chou and added to the claims to secure their allowance during reexamination.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 5, 9-12, 14, 15, 17, 18, 21, and 22 of the ’612 patent as unpatentable.