W&Wsens Devices Inc v. Samsung Electronics Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: W&Wsens Devices Inc. (Delaware)
  • Defendant: Samsung Electronics Co., Ltd. (Republic of Korea) and Samsung Electronics America, Inc. (New York)
  • Plaintiff’s Counsel: Capshaw DeRieux LLP; Kramer Levin Naftalis & Frankel LLP
• Case Identification: 2:24-cv-00854, E.D. Tex., 04/16/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendant Samsung Electronics America maintains a regular and established place of business in Plano, Texas, and has committed acts of infringement in the district. Venue is alleged to be proper for the foreign parent, Samsung Electronics Co., Ltd., because suits against foreign entities may be brought in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s CMOS image sensors and products containing them (such as the Galaxy smartphone line) infringe six patents related to the use of microstructures to improve light sensitivity in photosensitive devices.
• Technical Context: The technology at issue is Complementary Metal-Oxide Semiconductor (CMOS) image sensors, a foundational component in modern digital imaging devices, where improving performance in low-light conditions is a key market driver.
• Key Procedural History: The complaint alleges that Defendant had pre-suit knowledge of the asserted patent family as early as November 2018 through citations made during the prosecution of its own patents. The complaint further alleges that Plaintiff repeatedly contacted Defendant for licensing discussions beginning in April 2019, specifically identifying several of the patents-in-suit, which may be central to the allegations of willful infringement.

Case Timeline

Date	Event
2013-05-22	Earliest Priority Date for ’948, ’871, ’360, and ’084 Patents
2013-11-15	Earliest Priority Date for ’543 and ’700 Patents
2014-11-27	W&W patent application (WO 2014/190189) published
2016-03-01	Samsung explains "Dual Pixel technology" for Galaxy S7 launch
2016-12-20	U.S. Patent No. 9,525,084 issues
2018-11-16	Samsung allegedly becomes aware of W&W patents via USPTO
2019-04-25	W&W allegedly first contacts Samsung regarding patent portfolio
2019-10-15	U.S. Patent No. 10,446,700 issues
2019-11-05	U.S. Patent No. 10,468,543 issues
2020-02-20	W&W allegedly identifies ’084, ’700, and ’543 Patents to Samsung
2023-04-04	U.S. Patent No. 11,621,360 issues
2024-09-10	U.S. Patent No. 12,087,871 issues
2025-03-04	U.S. Patent No. 12,243,948 issues
2025-04-16	Complaint Filed

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

U.S. Patent No. 10,468,543 - “Microstructure Enhanced Absorption Photosensitive Devices,” Issued November 5, 2019

The Invention Explained

• Problem Addressed: The patent background describes the challenge facing CMOS image sensor design: as pixel dimensions shrink to increase resolution, the light-absorbing silicon layer must also become thinner (Compl. ¶19-21). Thinner silicon is inefficient at absorbing longer wavelength light, such as red and near-infrared, which reduces sensor performance in low-light conditions and for specific applications like depth sensing (’543 Patent, col. 3:3-12).
• The Patented Solution: The invention proposes embedding microstructures, such as holes or pillars, directly into the layers of a photodetector. These structures are designed to trap photons, forcing light to travel a longer effective path within the silicon material without physically increasing the device's thickness (’543 Patent, Abstract). This technique is intended to increase the quantum efficiency and enhance light absorption, particularly for longer wavelengths (’543 Patent, col. 4:50-55).
• Technical Importance: This approach aims to decouple the inverse relationship between pixel size and light sensitivity, a critical bottleneck in advancing the performance of high-resolution digital cameras (Compl. ¶22, 36).

Key Claims at a Glance

• The complaint asserts at least independent Claim 1 (Compl. ¶204).
• Claim 1 requires a single-chip device with:
  • A microstructure-enhanced photodetector (MSPD) and an active electronic circuit on a single substrate.
  • The MSPD comprising an intermediate region between first and second doped regions made of silicon, germanium, or an alloy.
  • "Holes intentionally formed" in at least one of said layers.
  • An input portion configured to receive optical input at a plurality of said holes.
  • Reverse-bias contacts.
  • The active electronic circuit configured to process the electrical output from the MSPD, including by amplification.
  • A communication channel to deliver the electrical output.

U.S. Patent No. 10,446,700 - “Microstructure Enhanced Absorption Photosensitive Devices,” Issued October 15, 2019

The Invention Explained

• Problem Addressed: The ’700 Patent addresses the same technical problem as the ’543 Patent: the poor absorption of longer wavelength light in thin silicon layers used in high-resolution CMOS sensors (’700 Patent, col. 3:3-12; Compl. ¶19-21).
• The Patented Solution: The solution is materially the same as that of the ’543 Patent, involving the use of microstructures like holes or pillars within the photodetector to enhance light absorption by increasing the effective optical path length (’700 Patent, Abstract; col. 4:60-63). The invention describes a "single-chip device" that monolithically integrates the photodetector and its processing electronics (’700 Patent, col. 4:60-63).
• Technical Importance: The invention seeks to enable the fabrication of smaller, more sensitive pixels, which is crucial for improving image quality in consumer electronics like smartphones, especially in challenging lighting conditions (Compl. ¶21-22).

Key Claims at a Glance

• The complaint asserts at least independent Claim 1 (Compl. ¶238).
• Claim 1 requires a single-chip device with:
  • An MSPD and an active electronic circuit on a single substrate.
  • The MSPD comprising an intermediate region between first and second doped regions made of silicon, germanium, or an alloy.
  • "Holes intentionally formed therein" extending in directions transverse to the layers.
  • The intermediate layer being less doped than the first and second regions.
  • An input portion configured to receive optical input at a plurality of said holes.
  • Reverse-bias electrodes.
  • The active electronic circuit configured to process the electrical output.
  • A communication channel to deliver the electrical output.

U.S. Patent No. 11,621,360 - “Microstructure Enhanced Absorption Photosensitive Devices,” Issued April 4, 2023

• Technology Synopsis: The patent describes a photosensitive device with a laterally extending array of pillars made of semiconductor material. These pillars contain deliberately formed holes filled with dielectric material to enhance light absorption and improve quantum efficiency, addressing the challenge of poor sensitivity in thin silicon layers (Compl. ¶36-37).
• Asserted Claims: At least independent Claim 1 (Compl. ¶172).
• Accused Features: Samsung's CIS Accused Products that use "dual-pixel autofocusing or RGB Bayer technology," where trenches between sub-pixels are alleged to function as the claimed "in-pillar holes" (Compl. ¶52, 62, 69).

U.S. Patent No. 9,525,084 - “Microstructure Enhanced Absorption Photosensitive Devices,” Issued December 20, 2016

• Technology Synopsis: The patent describes a photodetector for data communication comprising an absorbing region and integrated circuitry on the same substrate. The absorbing region contains a plurality of holes that enhance light absorption, particularly for infrared applications, by modifying light propagation within the material (Compl. ¶71-72).
• Asserted Claims: At least independent Claim 1 (Compl. ¶272).
• Accused Features: Samsung's Time-of-Flight (ToF) sensors, such as the ISOCELL Vizion line, which allegedly use "backside scattering technology" (BST) with shallow trench patterns to enhance infrared light sensitivity (Compl. ¶71-72, 74).

The complaint also asserts U.S. Patent Nos. 12,243,948 and 12,087,871, which relate to the same core technology and are asserted against the same CIS Accused Products (Compl. ¶105, 139).

III. The Accused Instrumentality

Product Identification

The complaint names two categories of accused products:

1. CIS Accused Products: Samsung’s ISOCELL line of CMOS image sensors that utilize dual-pixel or similar Phase Detection Auto Focus (PDAF) features, or RGB Bayer filter technologies such as Tetracell and Nonacell. Specific sensor models identified include the GN3 and HP2 (Compl. ¶47, 79).
2. ToF Accused Products: Samsung’s ISOCELL Vizion line of Time-of-Flight (ToF) sensors, including the Vizion 33D, 63D, and 931 models (Compl. ¶48, 72, 76).

The complaint also accuses end products incorporating these sensors, primarily Samsung’s Galaxy line of smartphones (e.g., S23 FE, S24 Ultra) (Compl. ¶44, 51).

Functionality and Market Context

• The accused CIS products are alleged to use trenches to separate photodiodes that function as a single pixel. In the "Dual Pixel" architecture, a trench separates two photodiodes that are used together for image capture (Compl. ¶56, 62). In Bayer technologies like "Nonacell," trenches separate a 3x3 group of sub-pixels that are processed to act as one larger pixel, particularly in low-light conditions (Compl. ¶63, 67). The complaint alleges these trenches are the claimed "holes" that improve light sensitivity (Compl. ¶53-54). A VSEM image provided in the complaint shows the alleged in-pixel deep trench isolation separating photodiodes (Compl. p. 18, Fig. 3).
• The accused ToF products are alleged to use "backside scattering technology (BST)," which incorporates "shallow deep trench isolation patterns" to enhance the sensor's quantum efficiency for infrared light, a key requirement for depth-sensing applications (Compl. ¶72, 74). The complaint alleges these trench patterns constitute the claimed light-absorbing holes.
• The complaint frames the accused products as part of Samsung's "flagship ISOCELL product line" and highlights their use in high-volume consumer electronics, suggesting significant commercial importance (Compl. ¶44, 50).

IV. Analysis of Infringement Allegations

10,468,543 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a single-chip device comprising an integrated combination of a microstructure-enhanced photodetector (MSPD) ... and an active electronic circuit...	The accused GN3 CMOS sensor is a single chip that integrates photodetection areas with active electronic circuitry for processing.	¶209, 211, 214	col. 5:11-18
the MSPD is on a single substrate and comprises an intermediate region, a first region at one side of the intermediate layer, and a second region at an opposite side of the intermediate layer...	The sensor is built on a single substrate with distinct doped semiconductor layers (p-type, n-type) and an intermediate (less doped) region between them.	¶211, 213	col. 5:19-32
at least one of said layers ... have holes intentionally formed therein, extending in directions transverse to the layers...	The photodetectors contain shallow in-pixel trenches, identified as the claimed "holes," which are fabricated into the silicon layers. A cross-section SEM image from a lab analysis shows these trenches.	¶209, 212; p. 84	col. 5:23-26
an input portion configured to concurrently receive at a plurality of said holes optical input...	Each pixel has a micro-lens that focuses light onto the photo-detecting regions containing the shallow trenches (holes).	¶212	col. 5:33-37
said active electronic circuit on or in said single substrate is configured to process the electrical output from the MSPD by applying amplification to form said processed output from the single-chip device...	Circuitry integrated on the chip, including a source-follower circuit, amplifies the photo-generated charges to create a processed electrical output.	¶216-217	col. 5:18-22
a communication channel on or in said single-chip device is configured to deliver the electrical output from the MSPD to the active electronic circuit.	A row driving signal and column metal trace (VPIXO) form a communication channel to route the processed signal to off-chip converters.	¶218	col. 6:1-5

Identified Points of Contention

• Scope Questions: A central dispute may arise over whether a "trench" created for electrical isolation between two photodiodes in a dual-pixel design constitutes a "hole intentionally formed" within a single MSPD. The plaintiff's theory depends on construing the two photodiodes as a single functional "photodetector" during image capture mode (Compl. ¶59, 62), which would make the trench an internal feature.
• Technical Questions: Does the complaint provide sufficient evidence that the accused "in-pixel deep trench isolation" (Compl. p. 19) is primarily intended for, or substantially functions as, a light-trapping microstructure as described in the patent? A defendant may argue its purpose is purely electrical isolation to reduce crosstalk, and any optical effect is incidental and distinct from the patented light-trapping mechanism.

V. Key Claim Terms for Construction

• The Term: "a microstructure-enhanced photodetector (MSPD)"

• Context and Importance: The definition of what constitutes a single "photodetector" is critical. The complaint alleges that multiple, physically distinct photodiodes or sub-pixels that are operated together to form a single image pixel collectively constitute one MSPD (Compl. ¶56, 63). If the court adopts a narrower construction requiring a single, unitary physical structure, the infringement theory for dual-pixel and Bayer-pattern sensors may fail, as the trenches would be between, not within, the MSPD.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent claims a "single-chip device" with an "integrated combination" of an MSPD and electronics, suggesting a focus on the functional integration of components on a chip rather than just the physical form of a single detector (’543 Patent, col. 118:15-18). This language may support reading the term to cover functional groupings.
  • Evidence for a Narrower Interpretation: The patent's detailed description and figures, such as Figure 9B, consistently illustrate an MSPD as a singular, continuous structure into which microstructures are formed (’543 Patent, Fig. 9B). The term "photodetector" itself, in the context of the prior art, typically refers to a discrete physical component.

• The Term: "holes intentionally formed therein"

• Context and Importance: This term's construction will likely focus on intent and function. Practitioners may focus on this term because the plaintiff must show that the accused trenches are not just incidental voids but are "intentionally formed" to serve the patented purpose of enhancing absorption.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent abstract states that microstructures like "holes" can "improve quantum efficiency" (’543 Patent, Abstract). The complaint alleges that Samsung's own technical articles report that its "in-pixel deep trenches improve light sensitivity," suggesting an intentional optical function consistent with the patent's disclosure (Compl. ¶54).
  • Evidence for a Narrower Interpretation: The patent specification repeatedly links the holes to enhancing absorption through mechanisms like "light trapping" (’543 Patent, col. 3:9). A defendant may argue that its "deep trench isolation" structures are intentionally formed for electrical isolation to "reduce crosstalk" (Compl. ¶58), a distinct technical purpose not explicitly claimed, and that any resulting optical enhancement is an unintended byproduct.

VI. Other Allegations

• Indirect Infringement: The complaint alleges Samsung induces infringement by encouraging and instructing third-party device manufacturers (e.g., Google, Motorola) and end-users to use the infringing CIS and ToF sensors. This is allegedly accomplished through marketing materials that praise the resulting "amazing light-sensitivity," user manuals, technical support, and developer forums (Compl. ¶128-132, 162-165).
• Willful Infringement: The willfulness allegations are based on purported pre-suit knowledge. The complaint alleges Samsung was aware of the W&Wsens patent family as early as November 2018, when a related application was cited by the USPTO during the prosecution of a Samsung patent application (Compl. ¶89). Further, it is alleged that W&Wsens began directly contacting Samsung employees in April 2019 to discuss its technology and identified specific patents-in-suit by February 2020, but Samsung continued its allegedly infringing conduct (Compl. ¶92, 97, 102).

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

• A core issue will be one of definitional scope: can the term "photodetector," as used in the patents, be construed to cover a functional grouping of physically separate photodiodes or sub-pixels, as implemented in Samsung's dual-pixel and pixel-binning technologies? The viability of the infringement case for most of the accused CIS products may depend on the answer.
• A key evidentiary question will be one of functional purpose: does Samsung's use of "deep trench isolation" constitute the "holes intentionally formed" for light absorption as claimed? The case may turn on whether evidence shows these trenches are primarily for electrical isolation, with incidental optical effects, or if they were intentionally designed and implemented to serve the patented light-trapping function.
• A third central issue will be willfulness: given the complaint's specific allegations of pre-suit notice from both USPTO citations and direct corporate communications, the court will need to evaluate Samsung's state of mind and whether its continued conduct, if found to be infringing, rose to the level of objective recklessness required for enhanced damages.