Enplas Display Device Corp. v. Seoul Semiconductor Co.

• Decision Date: 19 November 2018
• Docket Number: 2016-2599
• Citation: 909 F.3d 398
• Parties: ENPLAS DISPLAY DEVICE CORPORATION, Plaintiff-Appellant Enplas Tech Solutions, Inc., Enplas (U.S.A.), Inc., Plaintiffs v. SEOUL SEMICONDUCTOR COMPANY, LTD., Defendant-Appellee
• Court: U.S. Court of Appeals — Federal Circuit

909 F.3d 398

ENPLAS DISPLAY DEVICE CORPORATION, Plaintiff-AppellantEnplas Tech Solutions, Inc., Enplas (U.S.A.), Inc., Plaintiffs

v.SEOUL SEMICONDUCTOR COMPANY, LTD., Defendant-Appellee

2016-2599

United States Court of Appeals, Federal Circuit.

Decided: November 19, 2018

John C. Rozendaal, Sterne Kessler Goldstein & Fox, PLLC, Washington, DC, argued for plaintiff-appellant. Also represented by Michael E. Joffre.

Lawrence J. Gotts, Latham & Watkins LLP, Washington, DC, argued for defendant-appellee. Also represented by Gabriel Bell ; Charles Sanders, Boston, MA; Ryan Owens, Costa Mesa, CA.

Before Newman, Hughes, and Stoll, Circuit Judges.

Opinion concurring in part, dissenting in part filed by Circuit Judge Newman.

Opinion for the court filed by Circuit Judge Stoll.

Enplas Display Device Corporation appeals the district court’s summary judgment that claim 20 of Seoul Semiconductor Company, Ltd.’s ("SSC") U.S. Patent No. 6,007,209 is not anticipated. Following a jury trial on the remaining infringement and invalidity issues, Enplas also appeals the district court’s denial of judgment as a matter of law ("JMOL") that SSC’s U.S. Patent No. 6,473,554 is anticipated; denial of JMOL of no induced infringement; and denial of JMOL that the jury’s damages award is excessive and not supported by the trial evidence.

For the reasons below, we affirm the district court’s judgment that claim 20 of the ’209 patent and the asserted ’554 patent claims are not anticipated. Although a close question, we also affirm the district court’s denial of JMOL of no inducement. We hold, however, that the district court erred when it denied JMOL that the damages award was not supported by substantial evidence. We therefore vacate the jury’s damages award, and remand for further proceedings.

BACKGROUND

The asserted ’209 and ’554 patents are directed to methods of backlighting display panels, particularly LED displays used in televisions, laptop computers, and other electronics. In such displays, the ’209 patent teaches, "uniform illumination is difficult to achieve, and prior art devices frequently fail[ed] to provide a sufficiently uniform source of illumination for LCD displays." ’209 patent col. 1 ll. 36–38. The invention claimed in the ’209 patent purports to solve this problem by providing a light source that uniformly backlights the rear surface of the display panel. Id. at col. 1 ll. 45–48. The light source includes "a housing having a cavity formed by diffusely reflective bottom and side interior surfaces." Id . at col. 1 ll. 46–48. "Illumination is provided by [LEDs] that are shielded by shielding elements." Id . at col. 1 ll. 50–51. The LEDs and shielding elements are "positioned such that the emitted light is substantially uniformly distributed throughout the cavity, thereby eliminating bright spots (i.e., ‘hot spots’) in the display panel." Id. at col. 1 ll. 52–55.

Claim 20 of the ’209 patent recites:

20. A method of backlighting a display panel, comprising:

producing illumination from a substantially lambertian light source comprising a cavity with internal side walls, an internal bottom wall, and an aperture, said step of producing illumination comprising the step of directing light rays emitted by plural light sources mounted on said internal bottom wall and around the perimeter of the aperture into the cavity such that the light exiting the aperture is substantially uniform in intensity and color;

using a diffuser to diffuse light from said substantially lambertian light source;

using a brightness enhancing film to concentrate the diffused light into a predetermined angular range without significantly reducing the uniformity of the diffused light; and

directing the concentrated, diffused light onto said display panel.

Id . at col. 9 l. 18–col. 10 l. 8 (emphasis added).

The ’554 patent, however, purports to solve the illumination uniformity problem in a different way. The patent discloses a lighting apparatus using a "waveguide coupled to a light source for injecting light into the waveguide." ’554 patent, Abstract. Embedded within the waveguide is "an illumination coupler." Id . at col. 3 ll. 18–20. The illumination coupler "comprises a refractive index interface configured to capture light rays propagating along a line that forms less than the critical angle of total internal reflection with respect to at least one of the top and bottom surfaces, such that the captured light rays are injected therebetween for propagation outside of the interior region." Id. at col. 3 ll. 23–29. The illumination coupling element has two curved surfaces in its top surface that form the total internal reflection ("TIR") region above the LED and a bottom surface above the LED. Id. at col. 16 ll. 14–24. The bottom surface works with the TIR region to distribute light within the waveguide. Id. at col. 16 ll. 27–48.

Through TIR, the ’554 patent solves the bright spot problem by preventing light from shining directly from the light source through the display. The curved portions of the TIR region, however, also create a "dark spot" by completely redirecting light above the LED. Id. at col. 14 ll. 58–61. To counter this problem, the ’554 patent discloses a rounded bottom TIR surface that is configured to allow a small amount of light to "leak" through its top surface to ensure uniformity in the display. Id. at col. 14 l. 61–col. 15 l. 3. This is known as "leaky TIR." Id. at col. 15 ll. 1–3.

Claims 1, 6, 30, and 33–35 of the ’554 patent are reproduced below:

1. An illumination device, comprising:

a waveguide having an illumination coupler embedded in an interior region of said waveguide, said illumination coupler adapted to receive light from a point source within said interior region, and to direct light between generally parallel top and bottom surfaces outside said interior region, said illumination coupler comprising a refractive index interface which is inclined relative to at least one of said top and bottom surfaces said interface being configured to reflect light rays emitted by the point source which propagate along a line that forms less than the critical angle of total internal reflection with respect to a line lying in one of said top and bottom surfaces, such that light rays which would otherwise pass out of said waveguide are captured for propagation between said top and bottom surfaces.

....

6. The illumination device of claim 1, wherein the waveguide and illumination coupler are integrally formed from a single piece of material.

....

30. An optical apparatus, comprising:

a light emitting diode (LED);

an optical element having top and bottom opposing sides and an edge extending between the top and bottom opposing sides, said LED mounted at a predetermined location beneath a central portion of said optical element such that light from the LED enters the optical element, said optical element including a TIR surface spaced from said bottom side and extending from a point above the LED outwardly towards said edges, said TIR surface positioned to receive light emitted by the LED, said TIR surface curving towards the LED so as to form a cusp above the LED, the curving TIR surface totally internally reflecting light rays such that reflected light rays propagate from the TIR surface towards the edge of the optical element.

....

33. The optical apparatus of claim 30, wherein said TIR surface is leaky such that some light emitted by the LED is transmitted therethrough.

34. The optical apparatus of claim 33, wherein said cusp is contoured to permit leakage of light through said TIR surface.

35. The optical apparatus of claim 34, wherein said cusp is rounded to permit leakage of light through said TIR surface.

Id . at col. 19 ll. 2–17, col. 19 ll. 31–33, col. 21 ll. 8–23, col. 21 ll. 28–36 (emphases added).

Enplas is a Japanese manufacturer of plastic lenses used in "light bars," which are used for backlighting displays in flat-screen televisions. SSC is a Korean company that manufactures and sells LEDs, which are also used in light bars for backlighting flat-screen televisions, as well as automotive, smartphone, and lighting applications. From November 2010 to June 2011, SSC and Enplas collaborated to manufacture lenses for SSC’s light bars, which are covered by SSC’s ’209 and ’554 patents. SSC presented testimony that, during this joint development period, SSC employees informed Enplas that the end product, including SSC’s LEDs and Enplas’s lenses, would be covered by SSC’s patents. SSC also presented testimony that it had understood that it would have an exclusive relationship with Enplas for sales of the lenses.

In 2012, however, SSC suspected that Enplas had provided the lenses to SSC’s competitors who sold light bar products in the United States. SSC believed that those products infringed the ’209 and ’554 patents. To confirm its suspicion, SSC purchased several televisions from various retailers in the United States and took them apart for analysis. In particular, SSC purchased a Samsung Display LCD television, which used a lens supplied to Lumens Co., Ltd., and an LG Electronics LED television, which used lenses supplied to LG Innotek. SSC analyzed the televisions and determined that they contained infringing light bars with Enplas’s lenses. As a result, SSC sent Enplas a letter alleging that Enplas was inducing and contributing to the infringement of the ’209 and ’554 patents in the United States.

In response, Enplas filed the present declaratory judgment action against SSC, seeking a declaration that the ’209 and ’554 patents were invalid and not infringed. SSC counterclaimed, asserting infringement and seeking damages. SSC alleged that Enplas induced its direct and indirect customers to import, use, sell or offer for sale products infringing SSC’s patents.

Before trial, Enplas moved for summary judgment that claim 20 of the ’209 patent is anticipated by U.S. Patent No. 5,684,354 to Gleckman ("Gleckman"). The district court denied Enplas’s motion but converted SSC’s...