PTAB

IPR2015-00925

Apple Inc v. ZiiLabs Inc

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1. Case Identification

2. Patent Overview

  • Title: Doubly-Virtualized Texture Memory
  • Brief Description: The ’615 patent describes a graphics system with a multi-level memory hierarchy. The system uses a "doubly virtualized" dedicated graphics memory, wherein graphics data can be paged first into the host computer's main physical memory and then, as a second level, into the host's bulk storage (e.g., a hard disk).

3. Grounds for Unpatentability

Ground 1: Anticipation - Claims 1 and 3 are anticipated by Fukushima.

  • Prior Art Relied Upon: Fukushima (Patent 5,369,744).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Fukushima discloses every limitation of claims 1 and 3. Fukushima describes a data processing system with a central processing unit (CPU), main memory, a hard disk, and a separate graphic processor with its own dedicated frame buffer. Petitioner asserted this architecture directly maps to the claimed system: the frame buffer is the "specialized graphics memory," the main memory is the host's main memory, and the hard disk is the "bulk storage unit." Fukushima's memory management unit (MMU) virtualizes the address space, allowing data to be swapped from the hard disk to main memory and then accessed by the graphic processor, which constitutes a two-level virtualization system. For the claim 1 limitation requiring the bulk storage access time to be more than ten times that of main memory, Petitioner contended this was an inherent characteristic of any standard computer system of the era, a fact supported by extrinsic evidence.
    • Key Aspects: The core of this ground rested on mapping Fukushima’s memory paging system directly onto the patent’s "doubly virtualized" claim language, arguing the terms describe a well-known architecture.

Ground 2: Anticipation - Claims 1 and 3 are anticipated by Trevett.

  • Prior Art Relied Upon: Trevett (Patent 5,539,898).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Trevett, which was not cited during prosecution, also discloses all elements of the challenged claims. Trevett describes a high-performance graphics system with a host computer, a front-end board, and a renderer board. This system implements a multi-level virtual memory architecture where the renderer's VRAM ("specialized graphics memory") can page data from the front-end board's paging RAM ("main memory"), which in turn can page data from a fast disk ("bulk storage"). Petitioner argued this distributed system of page managers and memory swapping directly teaches the claimed two levels of virtualization for graphics memory. As with the Fukushima ground, the access time limitation was argued to be an inherent property of the disclosed hardware configuration.

Ground 3: Obviousness - Claims 1 and 3 are obvious over Fukushima in view of Hannah.

  • Prior Art Relied Upon: Fukushima (Patent 5,369,744) and Hannah (Patent 5,548,709).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented as an alternative, should the "rendering functions" of the claims be interpreted to require 3D rendering, which Petitioner argued Fukushima does not explicitly teach. Petitioner asserted Fukushima teaches a generally applicable virtual memory architecture for graphics. Hannah teaches the specific application of texture mapping for 3D graphics rendering.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to implement Fukushima's efficient virtual memory scheme in a 3D graphics system like that described in Hannah. The motivation was to improve performance for advanced graphics applications by allowing larger textures and more complex scenes than could fit in dedicated graphics memory alone, a well-known objective at the time.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in combining the references, as both relate to managing graphics data in a computer system and their combination represented the application of a known memory management technique (Fukushima) to a known graphics processing task (Hannah).

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Fukushima or Trevett with Hennessy (a textbook on computer architecture) to explicitly teach the relative memory access speeds, and further combinations of Trevett with Hannah to teach 3D rendering capabilities.

4. Key Claim Construction Positions

  • "specialized graphics-processing logic" (claims 1, 3): Petitioner proposed the construction "logic dedicated to processing graphics." This broad construction was important to ensure that general-purpose graphics processors disclosed in the prior art, like those in Fukushima and Trevett, would meet the claim limitation.
  • "said main memory is configured to provide a first level of virtualizing for said graphics memory" (claim 1): Petitioner proposed this means "the main memory is configured to provide a larger address space for the graphics memory through virtualization." This construction was critical for mapping the prior art's memory paging and swapping systems—which allow graphics memory to effectively use main memory as an extension of its own space—directly onto the claim language.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner's central technical contention was that the concept of using a multi-level virtual memory hierarchy—paging data from slower, larger storage (disk) to faster, smaller memory (RAM)—was a fundamental and non-inventive tool of general computer architecture long before the patent's filing date. The ’615 patent, in Petitioner's view, merely applied this well-known concept to the specific, and obvious, context of graphics processing, without adding any inventive technique for its implementation.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1 and 3 of the ’615 patent as unpatentable.