Ouster Inc v. Hesai Group

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Ouster, Inc. (Delaware)
  • Defendant: Hesai Group (Cayman Islands) and Hesai Technology Co., Ltd. (People's Republic of China)
  • Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Cooley LLP
• Case Identification: 1:23-cv-00406, D. Del., 04/11/2023
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because both defendants are foreign corporations and may be sued in any judicial district pursuant to 28 U.S.C. § 1391(c)(3).
• Core Dispute: Plaintiff alleges that Defendant’s LiDAR sensor products infringe five U.S. patents related to digital LiDAR architecture, optical systems, and mechanical design.
• Technical Context: The dispute is in the field of digital Light Detection and Ranging (LiDAR), a key perception technology enabling 3D environmental mapping for autonomous vehicles, robotics, and smart infrastructure.
• Key Procedural History: The complaint notes that Defendant Hesai was the subject of a 2019 International Trade Commission case brought by Velodyne Lidar concerning analog LiDAR technology, which resulted in a settlement.

Case Timeline

Date	Event
2015-09-24	Priority Date for ’381 and ’750 Patents
2016-08-24	Priority Date for ’236 Patent
2017-05-15	Priority Date for ’405 Patent
2018-12-04	Priority Date for ’515 Patent
2021-11-16	Issue Date for ’405 and ’381 Patents
2021-11-30	Issue Date for ’750 Patent
2022-01-XX	Accused Products displayed at CES 2022
2022-03-29	Issue Date for ’515 Patent
2022-08-23	Issue Date for ’236 Patent
2023-01-XX	Accused Products displayed at CES 2023
2023-04-11	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,175,405 - "Spinning Lidar Unit with Micro-Optics Aligned Behind Stationary Window"

The Invention Explained

• Problem Addressed: The patent addresses the technical challenge of creating wide field-of-view, narrowband optical imagers, such as those used in LiDAR, which are susceptible to performance degradation from crosstalk between adjacent receiver channels and difficulties in maintaining uniform spectral filtering across the entire sensor array (’405 Patent, col. 2:3-59).
• The Patented Solution: The invention proposes a spinning light ranging device housed within a stationary, optically transparent window. The system uses a micro-optic receiver array where each channel has its own aperture, collimating lens, and optical filter, an architecture designed to minimize crosstalk and ensure tight, uniform spectral selectivity across all channels (’405 Patent, Abstract; col. 6:50-65; Fig. 7).
• Technical Importance: This design approach allows for the creation of compact, high-resolution, 360-degree LiDAR sensors by using micro-optics to manage light paths at a granular level, a key step in moving from larger, mechanically complex analog systems to more scalable digital designs (’405 Patent, col. 2:61-67).

Key Claims at a Glance

• The complaint asserts independent claim 21 (’405 Patent, col. 54:1-35; Compl. ¶80).
• Essential elements of independent claim 21 include:
  • A stationary housing having an optically transparent window.
  • A spinning light ranging device disposed within the housing, which includes:
    • a platform;
    • an optical transmitter coupled to the platform, comprising a bulk transmitter optic and multiple transmitter channels with light emitters;
    • an optical receiver coupled to the platform, comprising a bulk receiver optic and multiple micro-optic receiver channels.
  • Each micro-optic receiver channel including an aperture, an optical filter, and a photosensor.
  • A motor to spin the light ranging device.
  • A system controller.
• The complaint reserves the right to assert additional claims, including dependent claims 23-24 (Compl. ¶80).

U.S. Patent No. 11,178,381 - "Optical System for Collecting Distance Information Within a Field"

The Invention Explained

• Problem Addressed: The patent describes the need for optical sensors that can collect distance information, noting that scaling resolution in such systems often introduces complexities in alignment and manufacturing (’381 Patent, col. 2:8-16).
• The Patented Solution: The invention is an optical system architecture comprising a set of illumination sources, a bulk imaging optic, an aperture layer at the focal plane, a set of lenses, an optical filter, and a set of pixels. This one-dimensional optical system is designed to be rotated to collect three-dimensional distance data of a volume, enabling a scalable approach to building a LiDAR sensor (’381 Patent, Abstract; col. 2:40-44; Fig. 1).
• Technical Importance: This architecture provides a foundational design for a digital LiDAR sensor by breaking the system into discrete, replicable one-dimensional channels that can be manufactured on a semiconductor substrate and rotated to achieve a 3D scan (’381 Patent, col. 2:40-54).

Key Claims at a Glance

• The complaint asserts independent claims 1 and 14 (’381 Patent, col. 14:4-40, 17:1-21; Compl. ¶89).
• Essential elements of independent claim 1 include:
  • A set of illumination sources arranged along a first axis.
  • A bulk imaging optic characterized by a focal plane.
  • An aperture layer coincident with the focal plane, defining a set of apertures.
  • A set of lenses aligned with the apertures.
  • An optical filter adjacent to the lenses.
  • A set of pixels adjacent to the optical filter.
• Essential elements of independent claim 14 include:
  • An optical system comprising a bulk transmitting optic and an illumination source.
  • An optical imaging receive module comprising a bulk receiving optic and a plurality of pixels, where each pixel has a field of view coincident with an emission region of a corresponding optical emitter.
• The complaint reserves the right to assert additional dependent claims (Compl. ¶89).

U.S. Patent No. 11,190,750 - "Optical Imaging System with a Plurality of Sense Channels"

• Patent Identification: U.S. Patent No. 11,190,750, “Optical Imaging System with a Plurality of Sense Channels,” issued November 30, 2021.
• Technology Synopsis: This patent details an optical imaging system built around a plurality of discrete "sense channels." Each channel consists of a dedicated aperture, lens, and pixel, creating a scalable architecture for high-resolution distance measurement. The invention focuses on the precise arrangement and interaction of these components to enable a compact and manufacturable LiDAR sensor.
• Asserted Claims: Independent claim 44 is asserted (’750 Patent, col. 19:1-24; Compl. ¶98).
• Accused Features: The complaint accuses Hesai’s PandarQT products of infringing the ’750 Patent (Compl. ¶11).

U.S. Patent No. 11,287,515 - "Rotating Compact Light Ranging System Comprising a Stator Driver Circuit Imparting an Electromagnetic Force on a Rotor Assembly"

• Patent Identification: U.S. Patent No. 11,287,515, “Rotating Compact Light Ranging System Comprising a Stator Driver Circuit Imparting an Electromagnetic Force on a Rotor Assembly,” issued March 29, 2022.
• Technology Synopsis: This invention addresses the electromechanical system for a rotating LiDAR sensor. It describes a compact motor design where a stator assembly on a first circuit board imparts an electromagnetic force on a rotor assembly on a second, rotationally coupled circuit board. This integrated motor design aims to reduce the size, complexity, and cost of the spinning mechanism.
• Asserted Claims: Independent claims 1, 14, and 22 are asserted (’515 Patent, col. 48:38-52:21; Compl. ¶107).
• Accused Features: The complaint accuses Hesai’s PandarQT and PandarXT products of infringing the ’515 Patent (Compl. ¶11).

U.S. Patent No. 11,422,236 - "Optical System for Collecting Distance Information Within a Field"

• Patent Identification: U.S. Patent No. 11,422,236, “Optical System for Collecting Distance Information Within a Field,” issued August 23, 2022.
• Technology Synopsis: This patent describes an optical system with a specific pixel array architecture for collecting distance information. It claims a pixel array with at least a first and second column of pixels, where the second column is both horizontally and vertically offset from the first. This "skewed grid" arrangement allows for different sampling patterns and can enhance resolution or dynamic range when the sensor is rotated.
• Asserted Claims: Independent claims 1, 10, 16, and 23 are asserted (’236 Patent, col. 20:1-22:24; Compl. ¶116).
• Accused Features: The complaint accuses Hesai’s PandarQT products of infringing the ’236 Patent (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

• The accused products include Hesai’s rotational LiDAR sensors, such as the PandarQT and PandarXT product lines, and its non-rotational (or “directional”) LiDAR product, the AT128 (Compl. ¶12).

Functionality and Market Context

• The accused products are digital LiDAR sensors used for 3D mapping and object detection in applications like autonomous mobility and robotics (Compl. ¶12). The complaint alleges that the core of these products is a transmit/receive (TX/RX) system that integrates vertical cavity surface emitting lasers (VCSELs) as emitters and silicon photomultipliers (SiPMs)—arrays of single photon avalanche diodes (SPADs)—as receivers (Compl. ¶9). The complaint includes a photograph of what it identifies as "Hesai's 128-channel TX/RX System," showing distinct chips for VCSEL arrays, SiPM arrays, and associated ASICs (Compl. ¶9, p. 5). The complaint alleges that Hesai’s products are sold to and used by U.S. customers, including a "leading global OEM headquartered in the United States" (Compl. ¶¶70-71).

IV. Analysis of Infringement Allegations

The complaint references confidential exhibits containing claim charts which were not publicly filed (Compl. ¶¶80, 89). The following summary is based on the complaint's narrative allegations and descriptions of the accused products.

'405 Patent Infringement Allegations

The complaint alleges that the accused rotational products, such as the PandarQT, meet the limitations of claim 21 of the ’405 Patent (Compl. ¶80). The theory appears to be that the PandarQT products are "spinning light ranging device[s]" containing an optical transmitter (VCSELs) and receiver (SPADs) that rotate inside of a "stationary housing" with a window, as claimed. Visual evidence in the complaint shows the PandarQT product, which has the external form factor of a rotating LiDAR unit with a stationary base and a rotating upper section containing optics (Compl. ¶73, p. 20).

'381 Patent Infringement Allegations

The complaint alleges that the accused products meet the limitations of claims 1 and 14 of the ’381 Patent (Compl. ¶89). The infringement theory appears to map the claimed optical system elements onto the components of Hesai’s TX/RX system. The claimed "set of illumination sources" and "set of pixels" are alleged to be met by Hesai's VCSEL and SiPM arrays, respectively (Compl. ¶9). The claimed "bulk imaging optic," "aperture layer," and "set of lenses" are presumably alleged to be found in the optical assemblies that direct light to and from these semiconductor arrays. A photograph in the complaint shows Hesai's TX and RX systems as multi-chip modules, which Ouster alleges contain the claimed components (Compl. ¶9, p. 5).

Identified Points of Contention

• Scope Questions: A central point of contention may be the construction of structural terms. For the ’405 patent, the dispute may involve the precise definitions of "spinning light ranging device" and its arrangement "disposed within the housing." For the ’381 patent, a question may be whether the accused products contain a distinct "aperture layer" that is "coincident the focal plane" as required by claim 1.
• Technical Questions: A key factual question will be whether the internal architecture of the accused products matches the specific arrangements claimed. For example, what evidence does the complaint provide that the accused PandarQT products, shown in an external view, contain internal components that rotate as a single "light ranging device" relative to a "stationary window" in the manner claimed by the ’405 Patent? Similarly, for the ’381 Patent, does the assembly of Hesai's TX/RX system (Compl. ¶9, p. 5) constitute the specific sequence of optical components required by the claims, or is there a functional or structural difference?

V. Key Claim Terms for Construction

The Term: "spinning light ranging device disposed within the housing" (’405 Patent, claim 21)

Context and Importance

This term is central to the structural identity of the claimed invention. The dispute will likely focus on the relationship between the rotating optical and electronic components (the "device") and the non-rotating external structure (the "housing"). Practitioners may focus on whether the entire light-ranging apparatus, including both transmitter and receiver, must spin as a single unit within a fully stationary external shell to meet this limitation.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The specification describes the light ranging device as including a "platform, optical transmitter, and optical receiver," and states it is "operatively coupled to spin" (e.g., ’405 Patent, col. 5:5-9). This functional language could support a construction that covers various mechanical arrangements where the operative optical components rotate.
• Evidence for a Narrower Interpretation: Figure 7 of the ’405 patent depicts a specific embodiment where the "light ranging device (701)" containing both sensing and transmitting modules (710) is mounted on a "rotating platform (708)" and spins entirely inside a stationary housing (702) behind a stationary window (704). This figure could be used to argue for a narrower construction requiring this specific structural configuration.

The Term: "an aperture layer coincident the focal plane" (’381 Patent, claim 1)

Context and Importance

This limitation defines a specific optical component at a precise location. Infringement will depend on whether the accused products contain a structure that both qualifies as an "aperture layer" and is located "coincident the focal plane" of the bulk imaging optic. Practitioners may focus on whether this requires a distinct physical layer with openings, or if an aperture function integrated into another component can satisfy the claim.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The patent describes the function of the apertures as constraining the pixel field of view and rejecting stray light (’381 Patent, col. 13:50-58). This functional description could support a broader interpretation where any structure performing these functions at the focal plane meets the limitation.
• Evidence for a Narrower Interpretation: Figure 2 depicts the "aperture layer 140" as a distinct physical layer with apertures (144) located at the focal plane of the bulk imaging optic (130). This embodiment, showing a discrete component, could support an argument that the term requires a separate, identifiable layer and not merely an aperture function integrated into another optical element.

VI. Other Allegations

Indirect Infringement

• The complaint alleges that Hesai induces and contributes to infringement. Inducement is alleged based on Hesai's promotion of the accused products through marketing materials, technical specifications, websites, and user manuals, which allegedly encourage infringing uses (Compl. ¶¶82, 91). Contributory infringement is alleged on the basis that the accused products are specially made for infringing use and are not staple articles of commerce (Compl. ¶¶83, 92).

Willful Infringement

• Willfulness is alleged based on asserted pre-suit knowledge of the patents. The complaint alleges that one of Ouster's patents, belonging to the same family as the asserted patents, is cited on the face of a U.S. patent owned by Hesai that was filed in February 2020, prior to the issuance of the patents-in-suit but allegedly providing knowledge of the patent family's technology (Compl. ¶¶82, 91, 100, 109, 118).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of claim scope and construction: can the structural limitations of the patents, such as a "spinning light ranging device disposed within the housing" (’405 Patent) and a distinct "aperture layer coincident the focal plane" (’381 Patent), be construed to read on the specific, and as-yet unrevealed, internal hardware architecture of Hesai’s commercial LiDAR products?
• A key evidentiary question will be one of technical proof: the complaint relies heavily on marketing materials, product photos, and high-level descriptions to allege infringement. The case will likely turn on whether discovery reveals a direct technical correspondence between the internal workings of the accused products and the specific arrangements of optical and mechanical components required by the asserted claims.
• A third central question will concern pre-suit knowledge and willfulness: will the allegation that Hesai cited an Ouster patent from the same family on its own patent be sufficient to establish pre-suit knowledge of the asserted patents, thereby supporting the claims for enhanced damages?