Hesai Technology Co Ltd v. Ouster Inc

1. Case Identification

• Case #: IPR2023-01456
• Patent #: 11,178,381
• Filed: September 25, 2023
• Petitioner(s): Hesai Technology Co. Ltd.
• Patent Owner(s): Ouster, Inc.
• Challenged Claims: 1-3, 5-8, and 10-17

2. Patent Overview

• Title: Optical System for Collecting Distance Information Within a Field
• Brief Description: The ’381 patent discloses a LiDAR (Light Detection and Ranging) system for collecting 3D distance information. The system comprises a transmit section with a plurality of optical emitters and a bulk transmitting optic, and an adjacent receive section with a bulk imaging optic, an optical filter, and a plurality of pixels, where each pixel includes a plurality of single-photon avalanche diodes (SPADs) to detect reflected photons.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 6-8, 10, 11, 14-17 are obvious over Retterath in view of Borowski

• Prior Art Relied Upon: Retterath (Patent 10,203,399) and Borowski (Application # 2013/0300838).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Retterath taught a multi-beam LiDAR system with nearly all claimed features, including a transmit macro lens (bulk transmitting optic), a receive macro lens (bulk imaging optic), and arrays of emitters and detectors with coincident fields of view. However, Retterath’s detectors were not explicitly SPAD-based. Petitioner asserted that Borowski supplied this missing element by teaching the use of detector arrays where each pixel comprises multiple SPADs to improve the performance of 3D imagers. The combination of Retterath’s overall LiDAR architecture with Borowski’s multi-SPAD pixel design allegedly rendered the system of independent claims 1 and 14 obvious.
  • Motivation to Combine: A POSITA would combine Borowski’s multi-SPAD detector teachings with Retterath’s LiDAR system to achieve several predictable benefits known in the art. These motivations included enhancing the signal-to-noise ratio, improving sensitivity for single-photon detection, increasing detection capability and accuracy by mitigating the dead time of individual SPADs, and improving the trade-off between image depth and data acquisition speed.
  • Expectation of Success: Petitioner contended that a POSITA would have a reasonable expectation of success because both references are in the same field of LiDAR technology and address analogous systems. Applying Borowski's known technique to improve detector performance in Retterath’s known LiDAR architecture was a predictable modification that would yield the expected benefits.

Ground 2: Claims 6-8 and 17 are obvious over Retterath in view of Borowski and Hipp

• Prior Art Relied Upon: Retterath (Patent 10,203,399), Borowski (Application # 2013/0300838), and Hipp (Patent 7,787,105).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the Retterath and Borowski combination to address claims reciting an "aperture layer." Petitioner argued that Hipp taught the use of a "shadow mask" in a detector array, which functions as the claimed aperture layer. Hipp’s mask included a plurality of apertures formed over pixels and a stop region between them, made of a thin opaque material to block stray light and prevent crosstalk between adjacent detector pixels.
  • Motivation to Combine: A POSITA would have been motivated to add Hipp’s shadow mask to the Retterath-Borowski system to further Retterath’s stated goal of reducing crosstalk. Signal interference was a well-known problem in multi-beam LiDAR systems, and Hipp’s aperture layer was an established solution designed specifically to address it by blocking unwanted photons from reaching the detectors.
  • Expectation of Success: The combination involved applying a known solution (Hipp's mask) to address a known problem (crosstalk) in a known system (the Retterath-Borowski LiDAR). This represented a simple and predictable design choice for a POSITA seeking to improve system performance.

Ground 3: Claims 1-3, 10-16 are obvious over Imai in view of Higashi

• Prior Art Relied Upon: Imai (Application # 2016/0274223) and Higashi (JP Publication No. 2015-078953).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Imai taught a scanning laser radar system with a laser diode array (emitters), a coupling lens (bulk transmitting optic), an imaging lens (bulk imaging optic), and a photodiode array (pixels), where the photodiodes could be SPADs. To the extent Imai did not explicitly teach pixels with multiple SPADs or an optical filter, Higashi supplied these elements. Higashi taught a radar device with detector pixels that each comprised multiple SPAD cells (e.g., four per pixel) and the use of a bandpass filter to eliminate background light.
  • Motivation to Combine: A POSITA would have been motivated to integrate Higashi’s teachings into Imai’s system to gain known advantages. Incorporating multi-SPAD pixels as taught by Higashi would reduce erroneous detections and improve sensitivity, and adding Higashi's suggested bandpass filter would improve the signal-to-noise ratio by filtering out interfering light sources.
  • Expectation of Success: Both references describe analogous LiDAR systems. A POSITA would have reasonably expected that incorporating Higashi's well-understood improvements—multi-SPAD pixels and bandpass filters, which were common in the art—into Imai’s system would predictably enhance its performance without undue experimentation.

• Additional Grounds: Petitioner asserted numerous additional obviousness challenges, including combinations of Retterath, Borowski, Weimer, Pacala, and Hipp to address features such as the use of VCSELs and rotational mechanisms. Petitioner also asserted grounds combining Imai, Higashi, Grzesik, and Pacala.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under Fintiv, stating that a related district court action was stayed in its infancy and an ITC investigation was terminated, making it highly unlikely that a court would resolve invalidity before a Final Written Decision in the IPR.
• Petitioner also argued against denial under §325(d), contending that the petition applies materially different prior art and arguments than those considered during prosecution. Petitioner asserted that none of the art relied on in the grounds was substantively applied by the examiner, who allowed the claims after a terminal disclaimer without any prior art-based rejections.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 5-8, and 10-17 of the ’381 patent as unpatentable.