Tianma Microelectronics Co Ltd v. Japan Display Inc

1. Case Identification

• Case #: IPR2021-01057
• Patent #: 7,385,665
• Filed: July 2, 2021
• Petitioner(s): Tianma Microelectronics Co. Ltd.
• Patent Owner(s): Japan Display Inc.
• Challenged Claims: 1-4

2. Patent Overview

• Title: Display Device
• Brief Description: The ’665 patent discloses an electrical terminal structure for connecting a liquid crystal display (LCD) panel to a flexible circuit board (FCB). The core inventive concept asserted during prosecution was the inclusion of a dummy pad group on the LCD panel that corresponds to a dummy terminal group on the FCB to prevent defective connections during thermal press-bonding.

3. Grounds for Unpatentability

Ground 1: Obviousness over Monzen and Hasegawa - Claims 1, 2, and 4 are obvious over Monzen in view of Hasegawa.

• Prior Art Relied Upon: Monzen (Application # 2004/0036833) and Hasegawa (Japanese Application # 2002-215059).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Monzen, which is in the same field as the ’665 patent, discloses all elements of independent claim 1 except for the corresponding dummy pads on the LCD substrate. Monzen teaches a display device with connection pads on an LCD substrate and connection terminals on an FCB, and notably includes dummy terminals on the FCB to address uneven thermal expansion. However, Monzen does not teach placing corresponding dummy pads on the LCD substrate opposite the FCB’s dummy terminals. Petitioner asserted that Hasegawa explicitly remedies this deficiency. Hasegawa identifies the precise problem with structures like Monzen’s—that having dummy structures on only one side causes non-uniform pressure, sagging, and connection defects during thermal press-bonding. Hasegawa’s solution is to add corresponding dummy terminals on the opposing substrate to create a one-to-one relationship, ensuring uniform pressure and reliable bonding. The combination of Monzen's foundational structure with Hasegawa's specific improvement allegedly renders claim 1 obvious.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Monzen and Hasegawa because both references address the identical problem of preventing connection defects during thermal press-bonding of an FCB to an LCD panel. A POSA reviewing Monzen’s solution would recognize the problem of non-uniform pressure and would have been motivated to consult art like Hasegawa, which directly teaches how to solve it by adding corresponding dummy pads. The combination represents a straightforward implementation of a known solution to a known problem.
  • Expectation of Success: A POSA would have a high expectation of success. The proposed modification involves adding a known, simple structural element (Hasegawa's corresponding dummy pads) to an existing device (Monzen's display) to achieve a predictable improvement in mechanical stability and connection reliability during thermal bonding. The result is not an unexpected synergy but the predictable outcome of applying a known fix.

Ground 2: Obviousness over Monzen, Hasegawa, and Maeda - Claim 3 is obvious over Monzen in view of Hasegawa and Maeda.

• Prior Art Relied Upon: Monzen (Application # 2004/0036833), Hasegawa (Japanese Application # 2002-215059), and Maeda (Japanese Application # 2002-357807).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that claim 3, which depends on claim 1, adds limitations for a "switch circuit" (i.e., a multiplexer) that connects signal supply lines to connection wiring lines. The base combination of Monzen and Hasegawa provides the structure of claim 1. Petitioner argued that Maeda teaches the additional elements of claim 3. Maeda discloses using a multiplexer on the same glass substrate as the pixels to reduce the number of required driver ICs and connection wiring. This allows for a more compact device with a larger effective display area. Maeda explicitly describes a switch circuit with switching elements (formed from polysilicon) that connect signal lines to the pixels.
  • Motivation to Combine: A POSA, having arrived at the improved bonding structure from Monzen and Hasegawa, would be motivated to incorporate Maeda's teachings to further optimize the display device. The motivations taught by Maeda—reducing component count, minimizing device footprint, and simplifying wiring layout—are well-known and highly desirable goals in display design. Therefore, integrating Maeda’s multiplexer into the Monzen-Hasegawa platform would have been a logical next step for a POSA seeking to create a more efficient and compact product.
  • Expectation of Success: The combination would yield a predictable result. Integrating a multiplexer into an LCD driver architecture is a standard and well-understood design practice. A POSA would understand how to implement Maeda's circuit in the Monzen-Hasegawa display and would fully expect to achieve the predictable benefits of reduced wiring complexity and a smaller panel frame without undue experimentation.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise discretionary denial under 35 U.S.C. § 314(a) based on the Fintiv factors. The petition asserted that while a co-pending district court litigation trial was scheduled before the statutory deadline for a Final Written Decision (FWD), the merits of the petition were exceptionally strong, weighing heavily in favor of institution. The strength derives from Hasegawa, a reference not considered during prosecution that directly teaches the key feature upon which the ’665 patent was allowed. Furthermore, Petitioner stipulated that if the inter partes review (IPR) was instituted, it would not pursue any invalidity ground in the litigation that was raised or reasonably could have been raised in the petition, thereby eliminating concerns of duplicative efforts and conflicting decisions.

5. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 1-4 of Patent 7,385,665 as unpatentable.