Image Sensors World Go to the original article...
International Image Sensor Society (IISS) has opened a LinkedIn page. Please feel free to follow to be updated about the latest events and announcements:
12-ps Resolution Vernier Time-to-Digital Converter for SPAD Sensor
January 24, 2021 By Leave a Comment
Image Sensors World Go to the original article...
MDPI paper "A 13-Bit, 12-ps Resolution Vernier Time-to-Digital Converter Based on Dual Delay-Rings for SPAD Image Sensor" by Zunkai Huang, Jinglin Huang, Li Tian,Ning Wang, Yongxin Zhu, Hui Wang, and Songlin Feng from Shanghai Advanced Research Institute, Chinese Academy of Sciences, presents a fairly complex pixel."In this paper, we propose a novel high-performance TDC for a SPAD image sensor. In our design, we first present a pulse-width self-restricted (PWSR) delay element that is capable of providing a steady delay to improve the time precision. Meanwhile, we employ the proposed PWSR delay element to construct a pair of 16-stages vernier delay-rings to effectively enlarge the dynamic range. Moreover, we propose a compact and fast arbiter using a fully symmetric topology to enhance the robustness of the TDC. To validate the performance of the proposed TDC, a prototype 13-bit TDC has been fabricated in the standard 0.18-µm complementary metal–oxide–semiconductor (CMOS) process. The core area is about 200 µm × 180 µm and the total power consumption is nearly 1.6 mW. The proposed TDC achieves a dynamic range of 92.1 ns and a time precision of 11.25 ps. The measured worst integral nonlinearity (INL) and differential nonlinearity (DNL) are respectively 0.65 least-significant-bit (LSB) and 0.38 LSB, and both of them are less than 1 LSB. The experimental results indicate that the proposed TDC is suitable for SPAD-based 3D imaging applications."
WDR Sensor with Binary Image Feature
January 24, 2021 By Leave a Comment
Image Sensors World Go to the original article...
IET Electronics Letters publishes a paper "CMOS image sensor for wide dynamic range feature extraction in machine vision" by Hyeon‐June Kim from Kangwon National University, Korea."The proposed pixel structure has two operating modes, the normal and WDR modes. In the normal operating mode, the proposed CIS captures a normal image with high sensitivity. In addition, as a unique function, a bi‐level image is obtained for real‐time FE even if a pixel is saturated in strong illumination conditions. Thus, compared to typical CISs for machine vison, the proposed CIS can reveal object features that are blocked by light in real time. In the WDR operating mode, the proposed CIS produces a WDR image with its corresponding bi‐level image. A prototype CIS was fabricated using a standard 0.35‐μm 2P4M CMOS process with a 320 × 240 format (QVGA) with 10‐μm pitch pixels. At 60 fps, the measured power consumption was 5.98 mW at 3.3 V for pixel readout and 2.8 V for readout circuitry. The dynamic range of 73.1 dB was achieved in the WDR operating mode."
Smartsens Released More than 30 Tapeouts in 2020
January 23, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Smartsens reports that it has released more than 30 tapeouts in 2020 or one tapeout every 12 days, on average. The company also won the "Unicorn Enterprise of the Year Award" from 2021 China Semiconductor Investment Alliance Annual Conference and China IC Billboard:
CMOS Sensors Design with Synopsys Custom Compiler
January 23, 2021 By Leave a Comment
Image Sensors World Go to the original article...
While most of analog design in the industry is done with Cadence EDA tools, Imasenic CTO Adria Bofill Petit presents an alternative path with Synopsys Custom Compiler:Call for Papers for Special Issue of 2022 IEEE TED on Solid-State Image Sensors
January 22, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Over the last decade, solid-state image sensors have sustained impressive technological developments as well as growth in existing markets such as camera phones, automotive cameras, security and industrial cameras and medical/scientific cameras. This has included:
- sub-micron pixels,
- high dynamic range sensors for automotive and machine vision,
- time-of- flight sensors for 3D imaging,
- 3-dimensional integration (wafer level stacking) for small and efficient imaging systems on a chip,
- sub-electron read noise pixels and avalanche photodetectors for single-photon imaging,
- detector structures for non-cooled infrared imaging,
- and many others.
Solid-state image sensors are also taking off into new applications and markets (IoT, 3D imaging, medical, biometrics and others). Solid-state image sensors are now key components in a vast array of consumer and industrial products. This special issue will provide a focal point for reporting these advancements in an archival journal and serve as an educational tool for the solid-state image sensor community. Previous special issues on solid-state image sensors were published in 1968, 1976, 1985, 1991, 1997, 2003, 2009 and 2016.
- Topics of interest include, but are not limited to:
- Pixel device physics (New devices and structures, Advanced materials, Improved models and scaling, Advanced pixel circuits, Performance enhancement for QE, Dark current, Noise, Charge Multiplication Devices, etc.)
- Image sensor design and performance (New architectures, Small pixels and Large format arrays, High dynamic range, 3D range capture, Low voltage, Low power, High frame rate readout, Scientific-grade, Single-Photon Sensitivity)
- Image-sensor-specific peripheral circuits (ADCs and readout electronics, Color and image processing, Smart sensors and computational sensors, System on a chip)
- Non-visible “image” sensors (Enhanced spectral response e.g., UV, NIR, High energy photon and particle detectors e.g., electrons, X-rays, Ions, Hybrid detectors, THz imagers)
- Stacked image sensor architectures, fabrication, packaging and manufacturing (two or more tiers, back-side illuminated devices)
- Miscellaneous topics related to image sensor technology
Submission deadline: July 30, 2021
Publication date: June 2022
GEO Semi Reports the 250 Automotive OEM Design Win Milestone
January 22, 2021 By Leave a Comment
Image Sensors World Go to the original article...
BusinessWire: GEO Semiconductor announces surpassing a major milestone for the company, 250 Automotive OEM design wins. These camera video processor (CVP) design wins represent engagements with over 30 different Tier 1 suppliers, and over a dozen of the world’s top automotive OEMs.“GEO released it’s first automotive product in 2015 and made the strategic decision to exclusively develop CVPs for automotive from that point forward. In the past 5 years we leveraged our world class team, our focused product strategy, and our customers to propel us to grow to the position of market leadership.” said Dave Orton, GEO Semiconductor CEO. “The world’s leading automotive companies chose GEO due to our camera, video, and computer vision expertise, and our ability to provide timely cutting edge solutions for these complex applications.”
Bucket-Brigade Device Inventor Kees Teer Passed Away at the Age of 95
January 21, 2021 By Leave a Comment
Image Sensors World Go to the original article...
ED: A former Philips Research Labs head Kees Teer passed away at the age of 95. Kees was the inventor of a bucket-brigate device, the predecessor of the CCD.
Smartsens Claims #1 Spot in CIS Volume for Machine Vision Applications
January 21, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Smartsens publishes a promotional video on global shutter advantages where it claims to be #1 in terms of machine vision image sensors shipment volume:
Samsung Aims to Take a Lead on Automotive CIS Market
January 20, 2021 By Leave a Comment
Image Sensors World Go to the original article...
PulseNews reports that, currently, Samsung market share in automotive image sensors is only 2%, after ON Semi, Omnivision, and Sony. Samsung intends to increase it and take a lead in automotive sensors.
ams’ NanEye Endoscopic Camera Reverse Engineering
January 20, 2021 By Leave a Comment
Image Sensors World Go to the original article...
SystemPlus publishes a reverse engineering of ams’ NanEye endoscopic camera:"To achieve an exceedingly small size and minimal cost, the NanEye relegates memory and image processing functionality off-chip and uses low-voltage differential signaling to stream image data at 38 Mbps. The NanEye includes a wafer-level packaged (WLP) 1 x 1 mm2 249 x 250-pixel front-side illuminated CMOS image sensor designed by AWAIBA (acquired by ams in 2015) and WLO technology developed by Heptagon (acquired by ams in 2016). Through-silicon via technology connects the sensor to the 4-pad solder-masked ball grid array package on the backside, facilitating integration into novel imaging products. The camera can be ordered with several preset optical configurations with an F-stop range of F2.4 – 6.0 and a field of view (FOV) range of 90° – 160°. The version analyzed in this report has an F-stop of F#4.0 and FOV of 120°."
f-stop Guru UL backpack review
January 20, 2021 By Leave a Comment
A good backpack is an important accessory for any photographer and over the last five years I’ve relied on the f-stop Guru UL. In this long-term test I’ll show you why the Guru UL has become my favourite photography backpack! …
Samsung CIS Capacity Expansion Chart
January 19, 2021 By Leave a Comment
Image Sensors World Go to the original article...
IFNews quotes HSBC report showing Samsung CIS capacity expanison chart:
SPAD Super-Resolution Sensing
January 19, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Nature publishes a joint paper of Bonn University, Germany, and Glasgow University, UK, "Super-resolution time-resolved imaging using computational sensor fusion" by C. Callenberg, A. Lyons, D. den Brok, A. Fatima, A. Turpin, V. Zickus, L. Machesky, J. Whitelaw, D. Faccio, and M. B. Hullin."Imaging across both the full transverse spatial and temporal dimensions of a scene with high precision in all three coordinates is key to applications ranging from LIDAR to fluorescence lifetime imaging. However, compromises that sacrifice, for example, spatial resolution at the expense of temporal resolution are often required, in particular when the full 3-dimensional data cube is required in short acquisition times. We introduce a sensor fusion approach that combines data having low-spatial resolution but high temporal precision gathered with a single-photon-avalanche-diode (SPAD) array with data that has high spatial but no temporal resolution, such as that acquired with a standard CMOS camera. Our method, based on blurring the image on the SPAD array and computational sensor fusion, reconstructs time-resolved images at significantly higher spatial resolution than the SPAD input, upsampling numerical data by a factor 12×12, and demonstrating up to 4×4 upsampling of experimental data. We demonstrate the technique for both LIDAR applications and FLIM of fluorescent cancer cells. This technique paves the way to high spatial resolution SPAD imaging or, equivalently, FLIM imaging with conventional microscopes at frame rates accelerated by more than an order of magnitude."
Brigates Prepares $207M IPO at Shanghai Stock Exchange
January 18, 2021 By Leave a Comment
Image Sensors World Go to the original article...
EastMoney, CapitalWhale, ElecFans: Yet another China-based image sensor company prepares an IPO at Shanghai Stock Exchange - Brigates (Chinese name - Ruixinwei or Ruixin Micro-Tech Innovation or Kunshan Ruixin.)"The IPO of the Science and Technology Innovation Board intends to raise 1.347 billion yuan for the R&D and industrialization projects of high-end image sensor chips and movement, as well as development and technology reserve funds.
So, what is the advantage of Ruixinwei?
The prospectus declares that: the company’s technologies and products in the field of high-end image chip customization and high-sensitivity camera cores have reached the domestic leading and internationally advanced level; “has a number of domestic leading and internationally advanced core technologies” and “breaks through foreign countries. "The technology monopoly of giants", "The company has become one of the few companies in the world that master ECCD technology", "It has replaced and surpassed similar foreign products, and filled many gaps in the field of domestic image sensors", "A few global suppliers Business One", "in a dominant position."
The Shanghai Stock Exchange took note of the company's above statement and requested the company to list the basis for its described market position.
In the reply letter, Ruixin Micro stated that it has revised "replacement and surpasses similar foreign products" in the prospectus to "partially replace similar foreign products", and at the same time, it will "achieve a subversive replacement of vacuum analog signal device technology." "Modified to "Realize the renewal of vacuum analog signal device technology".
For other statements, Ruixinwei believes that the statement is well-founded. In particular, the company mentioned that it is "the few companies in the world that master ECCD technology."
“The MCCD and ECCD technology independently developed by Ruixin Micro is helpful to improve the imaging quality of the image sensor.”
“At present, CMOS image sensor is the mainstream technology route, accounting for nearly 90% of the image sensor market. Ruixin Micro is equivalent to taking a new technological path. Ruixin Micro has developed a high-sensitivity camera core with MCCD technology as its core, has achieved industrialization. However, ECCD process development is very difficult, and currently there are relatively few publicly available materials."
Luminar CES Presentation Compares LiDAR Approaches
January 18, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Luminar publishes its presentations at CES2021. The first one done by Matt Weed compares the LiDAR technologies:
In its investor presentation, Luminar also shows its single-pixel InGaAs sensor integrated onto a Si ROIC and costing $3:
Modeling of Current-Assisted Photonic Demodulator for ToF Sensor
January 17, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Hong Kong University publishes a video presentation "Compact Modeling of Current-Assisted Photonic Demodulator for Time-of-Flight CMOS Image Sensor" by Cristine Jin Delos Santos. The work has won Best Student Paper Award at IEEE Student Symposium on Electron Devices and Solid-State Circuits (s-EDSSC) in October 2020.Review of SPAD Photon-to-Digital Converters
January 16, 2021 By Leave a Comment
Image Sensors World Go to the original article...
MDPI paper "3D Photon-to-Digital Converter for Radiation Instrumentation: Motivation and Future Works" by Jean-François Pratte, Frédéric Nolet, Samuel Parent, Frédéric Vachon, Nicolas Roy, Tommy Rossignol, Keven Deslandes, Henri Dautet, Réjean Fontaine, and Serge A. Charlebois from Université de Sherbrooke, Canada, reviews the new opportunities coming from SPAD stacked chip integration."Analog and digital SiPMs have revolutionized the field of radiation instrumentation by replacing both avalanche photodiodes and photomultiplier tubes in many applications. However, multiple applications require greater performance than the current SiPMs are capable of, for example timing resolution for time-of-flight positron emission tomography and time-of-flight computed tomography, and mitigation of the large output capacitance of SiPM array for large-scale time projection chambers for liquid argon and liquid xenon experiments. In this contribution, the case will be made that 3D photon-to-digital converters, also known as 3D digital SiPMs, have a potentially superior performance over analog and 2D digital SiPMs. A review of 3D photon-to-digital converters is presented along with various applications where they can make a difference, such as time-of-flight medical imaging systems and low-background experiments in noble liquids. Finally, a review of the key design choices that must be made to obtain an optimized 3D photon-to-digital converter for radiation instrumentation, more specifically the single-photon avalanche diode array, the CMOS technology, the quenching circuit, the time-to-digital converter, the digital signal processing and the system level integration, are discussed in detail."
Comments on Hamamatsu Patents Ownership Transfer to Sionyx
January 16, 2021 By Leave a Comment
Image Sensors World Go to the original article...
It appears that Federal Circuit decision to transfer an ownership of a number of Hamamatsu patents to SiOnyx has attracted quite a lot of attention from lawyers.Troy & Schwartz comments: "These days, Non-Disclosure Agreement (NDA) templates are readily available on-line, often free-of-charge, making them an attractive alternative for many. The problem with these templates is they are not necessarily applicable to the contracting parties’ unique circumstances and/or do not properly anticipate dealings between the parties. A poorly drafted, one-size-fits-all NDA can make or break a patent-infringement case many years into the future.
The outcome may well have been different had the NDA not “directed” the ownership of all future patents emanating from Sionyx’s confidential information to Sionyx. Furthermore, any resulting patent relying on confidential information emanating from both parties should have designated both Cary and an Hamamtsu inventor as joint inventors no matter where the patent applications were filed. Inventorship does not, however, mean that the inventor(s) is also the owner(s) of the patent.
As this case illustrates, an NDA can be a critical factor in determining patent (and other IP) ownership. An NDA should be tailor-made for the particular situation at hand with particular emphasis on protecting the disclosing party which is often an individual inventor or a small start-up company."
Finnegan comments: "So, even though both parties ended up with co-inventors on the disputed US and foreign patents, SiOnyx ended up as the sole owner of all those patents. The proofs established that confidential information relating to the patents came solely from SiOnyx. Hence, the terms of the NDA led to SiOnyx being the sole owner of all disputed patents."
Oliff writes: "Hamamatsu argued on appeal that because the district court acknowledged that Hamamatsu's personnel were co-inventors of the patents, it should have at most granted SiOnyx co-ownership rights. The Federal Circuit stated that inventorship was irrelevant to the issue of ownership, and that the terms of the NDA stated that when patents arose from a party's confidential information, that party would fully own such patents."
Apple iPhone 12 Cameras are Cheaper than iPhone 11’s
January 15, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Counterpoint Research says that iPhone 12 cameras cost $3.6 less than iPhone 11's:
ToF News: Chronoptics, Opnous, Microsoft
January 15, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Chronoptics announces its ToF noise filter and ToF camera based on Melexis VGA sensor:
Opnous OPNM8518A VGA camera module consumes 500mW typ and has a range of 1.2m:
MDPI paper "Evaluation of the Azure Kinect and Its Comparison to Kinect V1 and Kinect V2" by Michal Tölgyessy, Martin Dekan, Ľuboš Chovanec, and Peter Hubinský from Institute of Robotics and Cybernetics, Slovakia shows Microsoft progress over the years.
"The Azure Kinect is the successor of Kinect v1 and Kinect v2. In this paper we perform brief data analysis and comparison of all Kinect versions with focus on precision (repeatability) and various aspects of noise of these three sensors. Then we thoroughly evaluate the new Azure Kinect; namely its warm-up time, precision (and sources of its variability), accuracy (thoroughly, using a robotic arm), reflectivity (using 18 different materials), and the multipath and flying pixel phenomenon. Furthermore, we validate its performance in both indoor and outdoor environments, including direct and indirect sun conditions. We conclude with a discussion on its improvements in the context of the evolution of the Kinect sensor. It was shown that it is crucial to choose well designed experiments to measure accuracy, since the RGB and depth camera are not aligned. Our measurements confirm the officially stated values, namely standard deviation ≤17 mm, and distance error <11 mm in up to 3.5 m distance from the sensor in all four supported modes. The device, however, has to be warmed up for at least 40–50 min to give stable results. Due to the time-of-flight technology, the Azure Kinect cannot be reliably used in direct sunlight. Therefore, it is convenient mostly for indoor applications."
Samsung Adds 4th Sensor to its 108MP Lineup
January 14, 2021 By Leave a Comment
Image Sensors World Go to the original article...
BusinessWire: Samsung introduces its latest 108MP mobile sensor, the 0.8um 1/1.33-inch ISOCELL HM3. This is the 4th 108MP sensor in the company's lineup after HMX, HM1, and HM2.“Samsung has been at the forefront of bringing the most pixels to mobile image sensors as well as various supporting technologies that take sensor performances to the next level,” says Duckhyun Chang, EVP of the sensor business at Samsung Electronics. “The ISOCELL HM3 is the culmination of Samsung’s latest sensor technologies that will help deliver premium mobile experiences to today’s smart-device users.”
For faster AF, the HM3 integrates an improved Super PD Plus feature. Super PD Plus adds AF-optimized micro-lenses over the phase detection focusing agents, increasing measurement accuracy of the agents by 50%.
The HM3 also adopts Smart ISO Pro, HDR technology which uses an intra-scene dual conversion gain (iDCG) solution. Smart ISO Pro simultaneously captures a frame in both high and low ISO, then merges them into a single image in 12-bit color depth and with reduced noise. As Smart ISO Pro does not require multiple exposure shots to create a standard HDR image, it can significantly reduce motion-artifacts. In addition, with a low-noise mode, it improves the light sensitivity by 50% over its predecessor.
The HM3’s pixel layout is arranged in three-by-three single color structures suitable for nine-pixel binning. By merging nine neighboring pixels, the 108Mp HM3 mimics a 12Mp image sensor with large 2.4μm-pixels. With an improved binning hardware IP, the HM3 supports seamless transitions between 108MP and 12MP resolutions.
Design of the new sensor has also been optimized to reduce power in preview mode by 6.5%.
Samsung ISOCELL HM3 is currently in mass production.
CES News: Intel Demos Realsense ID and MEMS LiDAR
January 14, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Intel posted two videos with demos of its recently announced Realsense ID and L515 MEMS LiDAR:CES News: Trieye, Orbbeck, Guide Sensmart, Sense Photonics, Innolux, Nuralogix, Opsys, Pioneer, Ibeo
January 14, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Trieye presents the recent progress with its low-cost SWIR sensor, including DMS application:
Orbbec presents its first ToF camera with VGA resolution:
Wuhan Guide Sensmart Tech Co, a subsidiary of Guide Infrared, presents its compact thermal imaging modules for smartphones:
Sense Photonics presents its flash LiDAR components:
Innolux presents its under-display camera design and full-screen optical fingerprint sensor:
Nuralogix presents Anura applications claiming to be able to measure blood pressure with a smartphone selfie camera:
Opsys presents its modular LiDAR architecture:
Pioneer presents its MEMS-based LiDAR:
Ibeo presents its sequential flash LiDAR:
MIPI A-PHY Gears
January 13, 2021 By Leave a Comment
Image Sensors World Go to the original article...
MIPI publishes an article talking about the A-PHY standard gears. The scaling is quite impressive: speeds up to 16Gbps per lane with PAM4, 8, and 16(!) modulation schemes. The symbol rate stays at 4Gs/s, apparently limited by the long physical link bandwidth:
Sony FE 35mm f1.4 GM review
January 13, 2021 By Leave a Comment
The FE 35mm f1.4 G Master is a high-end wide-angle prime lens for Sony’s e-mount mirrorless system and one that’s corrected for full-frame bodies. It’s Sony’s fourth 35 in the native e-mount, but the first to join the flagship G-Master series. Find out why it’s their best 35 yet in my full review!…
CES News: NII, AIStorm, Innovusion, Brightway, Mcnex
January 13, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Japan National Institute of Informatics provides a protection from fingerprint recognition from camera images:
AIStorm presents its sensors without saying much about the underlying technology:
BrightWay Vision presents its VISDOM automotive gated vision camera performance:
"Independent tests performed under the DENSE European Research project evaluated the performance of the various available optical sensing technologies, including visual cameras, thermal imagers, and LiDARs, under adverse weather conditions. The project team concluded that the GatedVision sensor is the only one that could see all the tested targets, through dense fog and throughout the entire range tested. All other sensors were found limited to only half the range and limited types of objects detected."
Mcnex presents a scanning automotive camera:
A Conversation with Eric Fossum
January 12, 2021 By Leave a Comment
Image Sensors World Go to the original article...
Youtube channel Reliability Matters publishes "Episode 59: A Conversation with CMOS Image Sensor Inventor Dr. Eric Fossum."Omnivision Unveils 1080p60 Sensor for Mainstream Security Cameras
January 12, 2021 By Leave a Comment
Image Sensors World Go to the original article...
BusinessWire: OmniVision announces the OS02H10, a 2.9um, 1080p image sensor adding the NIR and low light performance of its Nyxel and PureCel Plus technologies to mainstream surveillance cameras. This sensor also offers multiple HDR options at 60 fps. Additionally, when paired with the designer’s selected platform, the OS02H10 can enable a system ultra low power mode for battery-powered cameras with AI functionality.“Mainstream surveillance camera designers are looking for the ideal the combination of low power consumption and high performance over a wide range of lighting conditions, to enable AI algorithm recognition of faces and objects,” said Cheney Zhang, senior marketing manager for the security segment at OmniVision. “The OS02H10 provides a high value option for adding premium NIR, ultra low light and HDR performance to high volume, mainstream security systems with AI functionality, along with an ultra low power mode that consumes 97.7% less power than the normal mode to support long battery life.”
Samples of the OS02H10 image sensor are available now.
ToF Sensor with Delta-Sigma Feedback
January 12, 2021 By Leave a Comment
Image Sensors World Go to the original article...
MDPI paper "High-Linearity High-Resolution Time-of-Flight Linear-Array Digital Image Sensor Using Time-Domain Feedback" by Juyeong Kim, Keita Yasutomi, Keiichiro Kagawa, and Shoji Kawahito from Shizuoka University, Japan, presents a sigma-delta feedback approach to linearize a ToF sensor response:
"This paper presents a high-linearity high-resolution time-of-flight (ToF) linear-array digital image sensor using a time-domain negative feedback technique. A coarse ToF measurement loop uses a 5-bit digital-to-time converter (DTC) and a delayed gating-pulse generator for time-domain feedback to find the zero of the difference between ToF and the digital estimate of the gating-pulse delay while maintaining a constant operating point of the analog readout circuits. A fine ToF measurement uses a delta-sigma modulation (DSM) loop using the time-domain feedback with a bit-stream signal form. Because of the self-contained property of the DSM for low distortion and noise exploited by the oversampling signal processing, the proposed technique provides high-linearity and high-range resolution in the fine ToF measurement. A prototype ToF sensor of 16.8 × 16.8 μm2 two-tap pixels and fabricated in a 0.11 μm (1P4M) CMOS image sensors (CIS) process achieves +0.9%/−0.47% maximum nonlinearity error and a resolution of 0.24 mm (median) for the measurement range of 0–1.05 m. The ToF sensor produces an 11-bit fully digital output with a ToF measurement time of 22.4 ms."
