Canon U.S.A., Inc. v. Slingshot Printing LLC

1. Case Identification

• Case #: IPR2022-01414
• Patent #: 7,195,341
• Filed: August 23, 2022
• Petitioner(s): Canon U.S.A., Inc., and Canon Inc.
• Patent Owner(s): Slingshot Printing LLC
• Challenged Claims: 1-5 and 8

2. Patent Overview

• Title: Semiconductor Substrate for a Micro-fluid Ejection Device
• Brief Description: The ’341 patent discloses a layout for a semiconductor substrate used in micro-fluid ejection devices, such as inkjet printers. The invention aims to reduce substrate size by arranging ejection actuators, power transistors, and logic circuits in adjacent columnar arrays and using a second metal layer for power and ground busses that overlap the power transistor and logic circuit areas, respectively.

3. Grounds for Unpatentability

Ground 1: Claims 1-5 and 8 are obvious over Torgerson and Bruce.

• Prior Art Relied Upon: Torgerson (Patent 6,412,917) and Bruce (Patent 7,240,997).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Torgerson, which describes a substrate for an inkjet printhead, discloses nearly every element of the challenged claims. Torgerson teaches a semiconductor substrate with columnar arrays of micro-fluid ejection actuators (heater resistors) adjacent to fluid supply slots. It also discloses adjacent columnar arrays of power transistors (FETs) and logic circuits. Critically, Torgerson connects the power transistors to the actuators via a first metal conductor layer and connects the logic circuits to the power transistors via a polysilicon conductor layer. It further discloses a power conductor (primitive select traces) in a second metal layer that overlaps the power transistor active area. Petitioner contended the only element Torgerson fails to explicitly disclose is a ground conductor routed in the second metal conductor layer that overlaps the logic circuit area. Bruce was introduced to supply this missing element, as it expressly teaches routing a ground conductor in a second metal layer that overlies the logic portions of the substrate.
  • Motivation to Combine: Petitioner asserted a person of ordinary skill in the art (POSITA) would combine Torgerson and Bruce because they are analogous arts addressing the identical problem of reducing printhead substrate size. Bruce teaches that placing the ground conductor in the second metal layer over the logic area "avoids costs associated with increased die sizes" and improves performance. A POSITA would have been motivated to apply this known, size-reducing layout from Bruce to Torgerson's similar design to achieve the same predictable benefits.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination, as it involved applying a known layout technique for a ground conductor to a similar device to achieve the well-understood and predictable result of a more compact and efficient design.

Ground 2: Claims 1-5 and 8 are obvious over Furukawa and Torgerson.

• Prior Art Relied Upon: Furukawa (Japanese Application No. 1996-108536) and Torgerson (Patent 6,412,917).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Furukawa teaches a compact board layout for a recording head that discloses the core architecture of the ’341 patent. Furukawa shows adjacent heaters (actuators), power transistors, and logic circuits. Significantly, it teaches forming both a power supply line and a ground line in a second metal layer, with the power line overlapping the power transistors and the ground line overlapping the logic circuits. Petitioner argued Furukawa is deficient only in that it does not explicitly teach (1) fluid supply slots adjacent to the actuators or (2) a polysilicon conductor layer connecting the power transistors to the logic circuits. Torgerson was introduced to supply these elements. Torgerson teaches using multiple ink feed slots for multi-color printing and using a polysilicon layer to connect its FET drive circuits to its decoder logic circuits.
  • Motivation to Combine: Petitioner argued a POSITA would be motivated to combine the references to create a more functional and compact printhead, a goal shared by all three documents. Incorporating Torgerson's well-known fluid supply slots would be an obvious and necessary modification to make Furukawa's recording head operational as an inkjet printer. Furthermore, modifying Furukawa to use Torgerson’s FETs and polysilicon connections would be an obvious design choice to improve performance and further miniaturization, as FETs are known to provide better operational functions without requiring more space.
  • Expectation of Success: A POSITA would have expected success in combining these teachings. Incorporating standard features like fluid supply slots and established connection methods like polysilicon for FETs into Furukawa's compatible base design are routine engineering tasks that would predictably result in an improved, miniaturized printhead.

4. Arguments Regarding Discretionary Denial

• Petitioner dedicated substantial argument to why discretionary denial under 35 U.S.C. §314(a) based on Fintiv factors would be inappropriate. The core arguments were that the parallel district court litigation is in a very early stage with minimal investment by the court and parties, and no trial date has been set. Petitioner asserted that the statutory deadline for a Final Written Decision (FWD) in the IPR would occur well before any potential trial, which weighs heavily against denial. While acknowledging an overlap in issues, Petitioner argued that an IPR would be a more efficient use of resources and would simplify issues for the district court. Petitioner also contended that the merits of the petition are strong, the cited prior art was never considered by the USPTO, and public policy favors the cancellation of invalid patent claims.

5. Relief Requested

• Petitioner requests institution of an inter partes review for claims 1-5 and 8 of Patent 7,195,341, a finding that those claims are unpatentable, and cancellation of the claims.