DCT

2:26-cv-04260

SmartSens Technology Shanghai Co Ltd v. OmniVision Tech Inc

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Amended Complaint
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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:26-cv-04260, C.D. Cal., 09/28/2026
  • Venue Allegations: Venue is alleged to be proper because Defendant OmniVision has a regular and established place of business within the Central District of California and has committed alleged acts of infringement in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s complementary metal-oxide-semiconductor (CMOS) image sensors infringe two U.S. patents related to pixel architecture for noise reduction and compact pixel layouts.
  • Technical Context: The technology concerns the design of CMOS image sensors, which are fundamental components in a wide range of electronic devices, including smartphones and automotive safety systems.
  • Key Procedural History: The complaint alleges that in a separate litigation, OmniVision admitted that patent publication with the USPTO constitutes notice to the world, a point relevant to willfulness allegations. The complaint also makes specific allegations of pre-suit knowledge based on OmniVision’s hiring of a former SmartSens engineer and its citation of one of the patents-in-suit during its own patent prosecution.

Case Timeline

Date Event
2016-04-29 ’890 Patent Priority Date
2017-03-07 ’890 Patent Application Filing Date
2017-06-22 ’890 Patent Application Publication Date
2017-06-01 Dr. Zhe Gao, a former OmniVision employee, begins working for a SmartSens affiliate
2018-04-01 Dr. Gao leaves the SmartSens affiliate and subsequently returns to OmniVision
2018-10-30 ’890 Patent Issue Date
2019-01-25 ’601 Patent Priority Date
2019-08-01 Will Semiconductor acquires OmniVision
2020-09-15 ’601 Patent Issue Date
2023-06-19 OmniVision announces the accused OX02C1S image sensor
2023-10-01 Alleged date of OmniVision's knowledge of the ’601 Patent via citation in its own patent prosecution
2025-04-10 OmniVision announces the accused OV50X image sensor
2025-07-01 Accused OV50X sensor scheduled for mass production (Q3 2025)
2026-09-28 Complaint Filing Date

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

U.S. Patent No. 10,116,890 - Imaging apparatus and imaging method using difference between reset signal and pixel signal stored to two capacitors

The Invention Explained

  • Problem Addressed: The patent’s background describes a problem with conventional global shutter CMOS image sensors where noise cannot be fully eliminated because the readout of the image signal and the reset signal are not "correlated in a full sense" ([’890 Patent, col. 1:49-54](https://ex:cit:1)). This lack of correlation leads to a decreased signal-to-noise ratio (SNR) ([’890 Patent, col. 1:53-54](https://ex:cit:2)).
  • The Patented Solution: The invention proposes a new pixel architecture that stores the 'reset' signal and the 'pixel' signal in two separate, dedicated capacitors within the pixel itself ([’890 Patent, abstract](https://ex:cit:3)). By capturing both signals in storage elements before readout, the architecture enables a full correlated double sampling (CDS) process, which allows for more effective noise cancellation when the difference between the two signals is generated ([’890 Patent, col. 6:35-49](https://ex:cit:5)). This is referred to in the complaint as a "voltage domain" approach ([Compl. ¶55](https://ex:cit:4)).
  • Technical Importance: This design aims to improve image quality in global shutter sensors, which are critical for capturing fast-moving objects without distortion in applications like machine vision and automotive systems.

Key Claims at a Glance

  • The complaint asserts "one or more claims" of the ’890 Patent, with a focus on Claim 1 ([Compl. ¶61](https://ex:cit:6); [Compl. ¶64](https://ex:cit:7)).
  • Independent Claim 1 requires, among other elements:
    • An imaging apparatus with a pixel array.
    • At least one pixel comprising an output transistor, "a first capacitor configured to store a reset signal, and a second capacitor configured to store a pixel signal."
    • A plurality of column circuits that reads the reset signal from the first capacitor and the pixel signal from the second capacitor to generate a difference.
    • A specific sequence where "the pixel is configured to store the pixel signal to the second capacitor after the reset signal is stored to the first capacitor."
    • Detailed limitations on the operation of the output transistor and grounding of the column output line to reduce noise and ensure autozeroing.

U.S. Patent No. 10,777,601 - CMOS image sensor with compact pixel layout

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of sensor miniaturization, where shrinking pixel sizes can lead to a loss of photosensitivity and dynamic range ([’601 Patent, col. 1:45-54](https://ex:cit:8)). Designing compact pixel layouts that still perform well is a key industry problem.
  • The Patented Solution: The invention describes a highly compact "shared pixel unit" where four photodiodes are arranged to share common readout circuitry, including a single reset transistor and a single source follower amplifier transistor ([’601 Patent, abstract](https://ex:cit:9)). The core of the solution is a specific physical layout where components are arranged as "mirror images" of each other, and the shared floating diode is placed at the "minimum distance" from the gate electrode of the source follower transistor, as allowed by the fabrication technology ([’601 Patent, col. 7:4-14](https://ex:cit:10)). This arrangement minimizes parasitic capacitance, which in turn improves conversion gain and performance.
  • Technical Importance: This layout enables the creation of higher-resolution image sensors by fitting more pixels into a given area without a corresponding degradation in image quality, a critical factor for devices like flagship smartphones.

Key Claims at a Glance

  • The complaint asserts "one or more claims" of the ’601 Patent, with a focus on Claim 1 ([Compl. ¶71](https://ex:cit:11); [Compl. ¶74](https://ex:cit:12)).
  • Independent Claim 1 requires, among other elements:
    • An image sensor array of shared pixel units.
    • Each unit comprising four photodiodes, multiple transfer transistors, and two shared floating diodes.
    • A shared reset transistor and a shared source follower amplifier transistor.
    • A specific geometric layout wherein "the layout of the first photodiode... is a mirror image of the layout of the second photodiode..." and a similar mirror image relationship exists for the third and fourth photodiodes.
    • A requirement that the shared floating diodes are "spaced at the minimum distance from a... gate electrode of the source follower transistor as is allowed by the CMOS fabrication technology."

III. The Accused Instrumentality

Product Identification

The complaint identifies two sets of accused products:

  1. Global Shutter Sensors: OmniVision OX02C1B, OX02C1S, and OX05C1S, accused of infringing the ’890 Patent ([Compl. ¶31](https://ex:cit:13)).
  2. Smartphone Sensor: OmniVision OV50X, accused of infringing the ’601 Patent ([Compl. ¶35](https://ex:cit:14)).

Functionality and Market Context

  • The OX-series sensors are described as global shutter sensors designed for automotive in-cabin applications, such as driver and occupant monitoring systems ([Compl. ¶32](https://ex:cit:15)). The complaint includes a screenshot from the website of distributor DigiKey, showing the OX02C1S is available for order in the United States ([Compl. ¶42](https://ex:cit:16)).
  • The OV50X is described as a 50-megapixel sensor for "flagship smartphones" that provides high dynamic range (HDR) and is built on stacked-die technology ([Compl. ¶¶35-36](https://ex:cit:17)). The complaint alleges the OV50X is used in the Xiaomi 17 Ultra smartphone and provides a screenshot from an eBay listing offering the phone for sale in the U.S. ([Compl. ¶45](https://ex:cit:18)).
  • The complaint alleges OmniVision sells and offers to sell these products in the U.S. directly and through distributors like Arrow Electronics, DigiKey, and third parties ([Compl. ¶¶40-41](https://ex:cit:19); [Compl. ¶44](https://ex:cit:20)).

IV. Analysis of Infringement Allegations

Although the complaint references claim chart exhibits that were not provided with the filing, it narrates a detailed infringement theory for each patent.

’890 Patent Infringement Allegations

The complaint alleges that OmniVision's accused global shutter sensors (OX02C1B, OX02C1S, OX05C1S) infringe the ’890 Patent by adopting its core technological approach ([Compl. ¶67](https://ex:cit:21)). The central allegation is that after hiring a former SmartSens engineer, Dr. Gao, who had worked on the patented technology, OmniVision "transitioned its product designs" ([Compl. ¶56](https://ex:cit:22)). Specifically, the complaint alleges that prior OmniVision products used a "charge domain" approach, while the accused products changed to the "voltage domain approach" taught by the patent, where the signal is stored in a capacitor located after the source follower transistor ([Compl. ¶¶54-57](https://ex:cit:23)). This directly corresponds to the ’890 Patent's innovative concept of using in-pixel capacitors to store both the reset and pixel signals for improved noise cancellation.

’601 Patent Infringement Allegations

The complaint alleges that the accused OV50X sensor infringes the ’601 Patent by copying its specific compact pixel layout ([Compl. ¶77](https://ex:cit:24)). The complaint draws a direct contrast between prior OmniVision sensors, which allegedly "used a different layout in which certain transistors were arranged around the photodiodes," and the accused OV50X, which allegedly "uses the layout claimed in the ’601 Patent, including positioning those transistors between the photodiodes" (Compl. ¶¶58, 77). This allegation maps directly onto the patent's claims, which require a specific "mirror image" arrangement of photodiodes and shared transistors to achieve superior compactness and performance. The complaint alleges this change in layout improved the performance of the OV50X ([Compl. ¶58](https://ex:cit:25)).

Identified Points of Contention

  • ’890 Patent - Technical Scope: A primary question for the court will be whether the architecture of the accused OX-series sensors falls within the scope of Claim 1. The analysis will likely focus on whether the accused products implement the claimed two-capacitor storage structure and readout sequence, or if there is a material technical difference in their operation.
  • ’601 Patent - Geometric Infringement: The infringement analysis will be a fact-intensive inquiry into the physical layout of the OV50X sensor. The dispute may turn on the interpretation of claim terms like "mirror image" and "minimum distance," and whether the accused product's physical arrangement meets these geometric constraints.

V. Key Claim Terms for Construction

Term: "a first capacitor configured to store a reset signal, and a second capacitor configured to store a pixel signal" (’890 Patent, Claim 1)

Context and Importance

This limitation is the cornerstone of the ’890 Patent's invention. The outcome of the case may depend on whether the accused devices' architecture, which the plaintiff describes as a "voltage domain" approach ([Compl. ¶57](https://ex:cit:26)), is found to have a structure that meets this two-capacitor limitation.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The claim language itself is partly functional, describing what the capacitors are "configured to store." A party could argue that any structure performing this function infringes, regardless of the precise circuit implementation.
  • Evidence for a Narrower Interpretation: The specification provides specific circuit diagrams (e.g., Fig. 6) showing the two capacitors, Crst and Csig, as distinct components within the pixel circuit ([’890 Patent, col. 6:35-38](https://ex:cit:36)). A party could argue the claims should be limited to such explicit structures shown in the embodiments.

Term: "the layout of the first photodiode... is a mirror image of the layout of the second photodiode..." (’601 Patent, Claim 1)

Context and Importance

This geometric term is central to the infringement allegation against the OV50X. Practitioners may focus on this term because the dispute will likely involve a highly technical, expert-driven comparison of the claimed "mirror image" symmetry against the actual physical layout of the accused sensor.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: A party might argue that "mirror image" does not require perfect geometric identity but rather a functional symmetry in the arrangement and operation of the components.
  • Evidence for a Narrower Interpretation: The specification strongly supports a literal, geometric meaning, stating that the photodiodes and associated transistors "are shown to be mirror images of each other about the horizontal line axis H H'" ([’601 Patent, col. 5:50-54](https://ex:cit:27)). The figures likewise depict a clear geometric reflection ([’601 Patent, Fig. 5](https://ex:cit:28); Fig. 9).

VI. Other Allegations

Indirect Infringement

The complaint alleges that OmniVision induces infringement of both patents. For the ’890 Patent, inducement is based on authorizing U.S. distributors to sell the accused OX-series sensors ([Compl. ¶62](https://ex:cit:30)). For the ’601 Patent, inducement is based on selling the OV50X to companies like Xiaomi with the knowledge that they will incorporate it into products sold in the U.S. ([Compl. ¶72](https://ex:cit:31)).

Willful Infringement

The complaint alleges willful infringement for both patents based on pre-suit knowledge.

  • For the ’890 Patent, knowledge is alleged through OmniVision's employment of a former SmartSens engineer, Dr. Gao, who allegedly worked on the patented technology at SmartSens before returning to OmniVision (Compl. ¶¶63, 68).
  • For the ’601 Patent, knowledge is alleged based on OmniVision having cited the published application corresponding to the ’601 Patent as prior art during the prosecution of its own patents as early as October 2023 (Compl. ¶¶73, 78).

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

  1. A central issue will be one of technical implementation: Does the accused "voltage domain" architecture in OmniVision's global shutter sensors operate in a manner that falls within the scope of the specific two-capacitor storage and readout method claimed by the ’890 Patent, or does it represent a distinct, non-infringing technology?
  2. The case will also turn on a question of geometric fact: Will a detailed analysis of the OV50X sensor's physical structure reveal the precise "mirror image" layout and "minimum distance" spacing required by the ’601 Patent's claims, a determination that will likely rely heavily on expert testimony regarding semiconductor design and fabrication rules.
  3. A significant question for damages will be scienter and intent: The complaint provides specific, fact-based allegations of pre-suit knowledge for both patents (a key former employee for the ’890 Patent and patent prosecution citations for the ’601 Patent). A key focus will be whether these allegations can be proven and used to establish willful infringement, which could expose the defendant to enhanced damages.