PTAB

IPR2022-00255

Kioxia Corp v. Sonrai Memory Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Portable RAM Drive
  • Brief Description: The ’527 patent discloses a portable memory apparatus, such as a RAM drive, containing both volatile (e.g., RAM) and non-volatile (e.g., flash) memory. When connected to a computer, data is transferred from non-volatile to volatile memory for faster access, and an internal power source enables data backup from volatile to non-volatile memory upon disconnection.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 15 and 17 under §102 over Yoshimura

  • Prior Art Relied Upon: Yoshimura (Patent 5,950,013).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Yoshimura, which discloses a memory card with a volatile main memory and a non-volatile flash sub-memory, anticipates the method of claim 15. When Yoshimura's card is connected to a host system (coupling), its controller copies data from the non-volatile sub-memory to the volatile main memory. The host system then accesses the data in the volatile memory. Upon power-off (disconnection), the controller copies data from the volatile main memory back to the non-volatile sub-memory for backup. For claim 17, Petitioner asserted that Yoshimura’s internal secondary battery is explicitly disclosed as being charged by the host system when connected, meeting the "recharging" limitation.

Ground 2: Obviousness of Claims 1-6 and 9-12 under §103 over Yoshimura in view of Ban

  • Prior Art Relied Upon: Yoshimura (Patent 5,950,013) and Ban (Patent 6,148,354).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Yoshimura discloses most elements of the apparatus claims, including a portable memory device with a housing containing a memory controller, volatile memory (SRAM), non-volatile memory (flash), and an internal power source. Ban discloses a portable USB flash drive, teaching a standardized USB connector and a controller that manages both the USB interface and the flash memory. The combination of Yoshimura’s memory architecture with Ban’s USB interface was argued to meet all limitations of independent claim 1.
    • Motivation to Combine: A POSITA would combine Yoshimura's memory card with Ban's USB interface to gain the well-known advantages of the USB standard. These benefits included simplified device development, reduced manufacturing costs, greater ease of use for the end-user, and widespread cross-platform compatibility, which were superior to older, proprietary interfaces.
    • Expectation of Success: Petitioner argued a POSITA would have had a reasonable expectation of success because Ban demonstrated a functional USB flash memory device. Adapting Yoshimura’s memory controller to incorporate a standardized USB interface controller was presented as a predictable design choice with known benefits.

Ground 3: Anticipation of Claims 15 and 17 under §102 over Kodera

  • Prior Art Relied Upon: Kodera (Japanese Laid-Open Patent Pub. No. H06-028114A).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that Kodera discloses a portable "semiconductor file memory device" that anticipates the method claims. Kodera’s device includes a volatile DRAM, a non-volatile hard disk, and a processor. When connected to an external device, the processor copies data from the non-volatile hard disk to the volatile DRAM (meeting the "copying" step). The external device then accesses the DRAM (meeting the "accessing" step). When external power is lost, the processor transfers data from the DRAM back to the hard disk (meeting the "updating" step). For claim 17, Kodera’s backup power source is described as rechargeable batteries that are charged when connected to the external device.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Yoshimura, Ban, and Tamura (for an impact-resistant shell); Kodera, Ban, and Tamura; and Kodera, Ban, Tamura, and Takamori (for substituting a solid-state memory for a hard disk).

4. Key Claim Construction Positions

  • "transfers said non-volatile memory with data written to said volatile memory" (Claim 6): Petitioner argued this phrase is open to two mutually exclusive interpretations.
    • Patent Owner's Apparent Construction: The memory controller transfers data from the non-volatile memory to the volatile memory.
    • Alternative Construction: The memory controller transfers data to the non-volatile memory from the volatile memory.
  • Petitioner contended that its unpatentability arguments render claim 6 invalid under either construction.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv would be inappropriate for several reasons:
    • The parallel district court litigation was in an early stage, with no Markman hearing held or depositions taken.
    • Petitioner intended to seek a stay of the litigation pending the outcome of the IPR.
    • Petitioner stipulated that it would not pursue the same grounds in district court if the IPR is instituted, minimizing issue overlap.
    • The asserted prior art was not considered during the original prosecution of the ’527 patent.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 9-12, 15, and 17 of the ’527 patent as unpatentable.