PTAB

IPR2015-00035

MasterImage 3D Inc v. RealD Inc

Log In

1. Case Identification

2. Patent Overview

  • Title: Combining P And S Rays For Bright Stereoscopic Projection
  • Brief Description: The ’455 patent describes systems and methods for increasing the brightness of stereoscopic 3D projection. The invention uses a polarizing splitting element to separate image light into two orthogonally polarized beams (P and S rays), rotates the polarization of one beam to match the other using a retarder, and then individually modulates both beams before they are optically superimposed on a screen, thereby nearly doubling the light energy compared to systems that discard one polarization.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-8, 10-14, and 16-22 over Schuck

  • Prior Art Relied Upon: Schuck (Patent 7,905,602).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Schuck, which is directed to a "Polarization Conversion System For Stereoscopic Projection," disclosed every element of the challenged claims. Schuck’s system receives image light from a projector lens and uses a polarizing beam splitter (PBS) to split it into a primary (p-polarized) and secondary (s-polarized) path. The s-polarized light in the secondary path is passed through a half-wave plate (a retarder) to rotate its polarization to match the primary path. A polarization switch (modulator) then receives light from both paths to create the stereoscopic effect on a screen. Petitioner asserted this structure directly maps to the limitations of independent claims 1, 16, 17, and 22, and that Schuck further discloses optional cleanup polarizers and specific PBS types (e.g., wire grid) as recited in various dependent claims.

Ground 2: Obviousness of Claims 9, 15, and 23 over Schuck in view of Applicant Admitted Prior Art

  • Prior Art Relied Upon: Schuck (Patent 7,905,602) and Applicant Admitted Prior Art (APA) from the ’455 patent specification, specifically the disclosure of a ZScreen push-pull modulator (from Lipton, Patent 4,792,850) and dual-projector systems.
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims requiring specific modulator types or system configurations not explicitly combined in Schuck. Claim 9 requires a "push-pull modulator," and claim 15 further specifies it comprises two pi-cells driven out of phase. Petitioner argued the ’455 patent itself identified the prior art ZScreen as a known push-pull modulator with this exact structure. Claim 23 adds a second projector with its own polarizing splitter and reflector. The ’455 patent’s background section also acknowledged that dual-projector systems were a well-known method for increasing brightness.
    • Motivation to Combine: A POSITA would have been motivated to implement the brightness-enhancing system of Schuck using the well-known ZScreen push-pull modulator described in the APA to gain its known operational benefits. For claim 23, a POSITA seeking even greater brightness for applications like large auditoriums would have found it obvious to apply Schuck's light-doubling optics to each projector in a conventional dual-projector setup, a straightforward duplication of components to achieve a predictable increase in brightness.
    • Expectation of Success: Petitioner asserted a POSITA would have had a high expectation of success, as combining these known elements—a light-recycling optical system with a standard type of modulator or a standard dual-projector configuration—involved predictable applications of established optical principles.

Ground 3: Anticipation of Claims 1, 3-5, 7-11, 14-17, 19, and 21 over Kim

  • Prior Art Relied Upon: Kim (WO 2006/038744).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner contended that Kim, which teaches a digital projection system for 3D displays, anticipates the challenged claims that do not require a retarder to align the polarization of the two light paths. Kim discloses a system using a cubic polarizing beam splitter to separate image light into primary (p-polarized) and secondary (s-polarized) paths. Instead of a retarder, Kim uses electro-optical shutters in each path that function as polarization modulators. These modulators receive the orthogonal light beams and modulate them to produce the 3D effect. Petitioner argued that for claims where the modulator receives separate, orthogonally polarized beams (i.e., claims lacking a retarder element), Kim’s system of a splitter, reflectors, and modulators in each path met every limitation.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 14 and 20 over Kim. This ground argued that even if not directly anticipated, it would have been obvious to modify Kim’s system based on known design principles (e.g., fabricating separate shutters as a single unit or modifying the lens placement for cost and performance benefits) to arrive at the claimed invention.

4. Key Claim Construction Positions

  • "uniformly modulate": Petitioner argued this term, added during prosecution to overcome prior art, should be construed as "any transformation in polarization state resulting from polarization modulation is applied equally to all portions of the incoming light." This construction was intended to distinguish from prior art spatial light modulators that modulate on a pixel-by-pixel basis. Petitioner used this construction to argue that the modulators in Schuck and Kim, which act on the entire beam, meet this limitation.
  • "polarization modulator": Proposed as "a device that receives light energy and outputs the light energy in at least two alternating states of polarization." This broad construction was used to argue that the polarization switch in Schuck and the electro-optical shutters in Kim fall within the scope of the term.
  • "image light energy": Construed as "light bearing an image such that when the light reaches a screen the image is viewable." This was used to establish that the prior art references operate, like the patent, on light that has already been imprinted with an image.

5. Relief Requested

  • Petitioner requests institution of inter partes review (IPR) and cancellation of claims 1-23 of the ’455 patent as unpatentable.