Saturday, November 30, 2019

Panasonic ToF Sensor for Mind Reading

Nature paper "Non-contact acquisition of brain function using a time-extracted compact camera" by Takamasa Ando, Tatsuya Nakamura, Toshiya Fujii, Teruhiro Shiono, Tasuku Nakamura, Masato Suzuki, Naomi Anzue-Satoi, Kenji Narumi, Hisashi Watanabe, Tsuguhiro Korenaga, Eiji Okada & Yasunori Inoue from Panasonic and Keio University, Japan, describes an optical camera for brain scanning:

"A revolution in functional brain imaging techniques is in progress in the field of neurosciences. Optical imaging techniques, such as high-density diffuse optical tomography (HD-DOT), in which source-detector pairs of probes are placed on subjects’ heads, provide better portability than conventional functional magnetic resonance imaging (fMRI) equipment. However, these techniques remain costly and can only acquire images at up to a few measurements per square centimetre, even when multiple detector probes are employed. In this study, we demonstrate functional brain imaging using a compact and affordable setup that employs nanosecond-order pulsed ordinary laser diodes and a time-extracted image sensor with superimposition capture of scattered components. Our technique can simply and easily attain a high density of measurement points without requiring probes to be attached, and can directly capture two-dimensional functional brain images. We have demonstrated brain activity imaging using a phantom that mimics the optical properties of an adult human head, and with a human subject, have measured cognitive brain activation while the subject is solving simple arithmetical tasks."

Friday, November 29, 2019

Lucid Vision Publishes EMVA Measurements of Sony 4th Generation BSI Global Shutter Sensor

Lucid Vision Labs publishes EMVA1288 data of its Atlas 10 camera based on 24MP Sony IMX530 sensor with 2.74um BSI pixels, a part of 4th generation Pregius-S family announced in October 2019:

Thursday, November 28, 2019

Panasonic to Sell Semiconductor Business to Nuvoton

Reuters: Panasonic announces the selling of its loss-making semiconductor unit to Taiwan’s Nuvoton, a part of Winbond Group, for $250M. The sale includes image sensor business and Tower-Panasonic JV fabs. The transaction is expected to close by June 2020.

Panasonic says, "...the competitive environment surrounding the semiconductor business has become extremely severe due to aggressive expansion of competitors, huge investments in the focused area, and industry reorganization through M&A. In such an environment, the Company has come to believe that the even stronger business operation and the continuous investment is critical in order to achieve a sustained growth and expansion of the semiconductor business.

Accordingly, it has concluded that the best option would be to transfer the business to Nuvoton, which highly appreciates the Company’s accumulated technical and product capabilities and therefore has a potential to lead stable growth by leveraging those capabilities.

Espros ToF Calculation Spreadsheet

Esporos November Newsletter promotes the company's ToF power and noise calculation spreadsheet:

II-VI Presentation on 3D Sensing

II-VI presentation on 3D sensing compares different approaches and spectral bands:

Wednesday, November 27, 2019

Low Resolution Sensors Shortage

IFNews quotes Laoyaoba report that VGA, 2MP, and 5MP image sensor prices went up by 20-40% due to the recent shortages. As more and more multi-camera configurations are now being applied to smart terminal products, the market demand mainly for mobile phones has further expanded, and the shortage and higher prices may continue.

In the past, Galaxycore used to ship ~100-110M sensors a month, but it's out of stock now. The price of Galaxycore 5MP sensors used to be 50-60 cents a piece, 2MP ones - 30 cents, but now 5MP sensor price grew up to 70 cents, while 2MP is 43 cents.

Whispering-Gallery-Mode Resonance Enhances Si PD Responsivity at 1,000nm

EurekaAlert reports that Korean POSTECH University developed a photodiode with increased absorption of the NIR light by using the hourglass-shaped silicon nanowire array. The research team was led by Prof. Chang-Ki Baek and consisted of Kihyun Kim, Myunghae Seo, and Sol Yoon. The team has proved that the hourglass-shaped silicon-nanowire photodiodes has 29% increased NIR photoreseponse at 1,000nm in comparison to the existing planar type silicon photodiode.

Prof. Chang-Ki Baek said “this study used the existing silicon processes that can be produced in mass at low cost and 100% compatible to the semiconductor production. It is very meaningful in that we were able to demonstrate increased photoresponse of the near-infrared light at the wavelength where the existing silicon hardly detect. It is possible that the developed device can optimize the absorption of the near-infrared wavelength desired according to the structure of nanowires such as diameter, length, and pitch. It is expected to provide optical solutions to various fields such as LiDAR of a self-driving vehicles, medical laser, military night vision goggles, image sensors and more.

Samsung Paper on AI Demosaicing

A preprint paper "Deep Demosaicing using ResNet-Bottleneck Architecture" by Divakar Verma, Manish Kumar, and Srinivas Eregala from Samsung R&D Institute Bengaluru, India, proposes CNN network to reduce demisaicing artifacts:

"Demosaicing is a fundamental step in a camera pipeline to construct a full RGB image from the bayer data captured by a camera sensor. The conventional signal processing algorithms fail to perform well on complex-pattern images giving rise to several artefacts like Moire, color and Zipper artefacts. The proposed deep learning based model removes such artefacts and generates visually superior quality images. The model performs well on both the sRGB (standard RGB color space) and the linear datasets without any need of retraining. It is based on Convolutional Neural Networks (CNNs) and uses a residual architecture with multiple `Residual Bottleneck Blocks' each having 3 CNN layers. The use of 1x1 kernels allowed to increase the number of filters (width) of the model and hence, learned the inter-channel dependencies in a better way. The proposed network outperforms the state-of-the-art demosaicing methods on both sRGB and linear datasets."

Actlight Announces Vital Signs Monitor with its DPD

PRNewswire: Actlight presents vital signs monitoring sensor based on its Dynamic Photo Diode. Despite ultra small detector area (less than 0.2mm2) and minimal LED power (less than 1uW/Hz), the sensor is said to deliver higher than 70dB SNR. The ActLight solution provides a strong output signal without AFE, further reducing the power consumption of the overall system.

Tuesday, November 26, 2019

ST Reports 1 Billion Shipped ToF Sensors

GlobeNewswire: STMicroelectronics announces the shipment of its 1 billionth ToF module. ST’s ToF sensors utilize SPADs manufactured at ST’s 300mm front-end fab in Crolles, France. The final module, which integrates the SPAD sensor, a VCSEL, and the necessary optical elements, is assembled and tested in ST’s internal back-end facilities.

ST has pioneered and transitioned Time-of-Flight technology from its research labs to a fully industrialized family of market-leading products that are now being used in more than 150 different smartphone models and have just passed the 1 billion module milestone,” said Eric Aussedat, GM of ST’s Imaging Subgroup. “In continuing to invest, ST has extended the FlightSense roadmap for Time-of-Flight products from high-performance 1-dimensional ranging devices to multi-zone solutions and most recently adding high-resolution 3D depth sensing capabilities to enable innovative applications using advanced proximity sensing, human presence detection, and laser autofocus.

The VL6180, VL53L0, and VL53L1 families of products, among others, are in high-volume production for consumer, personal computer, and industrial markets. ST’s vertically integrated manufacturing model for the ToF sensors ensures high levels of service, quality, customer support, and performance.

Monday, November 25, 2019

Voyage 81 on CFA Trade-offs

Israel-based Voyage 81 startup presentation discusses CFA approaches for low-light imaging (video is here):

EPIC Meeting on LiDAR

European Photonics Industry Consortium (EPIC) Meeting on LiDAR held at Eindhoven, The Netherlands on October 30-31, 2019, publishes many of its presentations. Few random slides:

Sunday, November 24, 2019

Sony Outstanding Engineer Awards

As a part of the first ever Sony Technology Day held at Sony City Osaki in Tokyo, Japan, on Sept. 18, 2019, the company announced SOE Awards. SOE stands for Sony Outstanding Engineer, the highest form of individual recognition for Sony Group engineers. Quite a few of the Awards went to image sensor designers:

  • Yoshihisa Kagawa for "Development of Novel Stacked CMOS Image Sensor with Cu-Cu Direct Bonding"
  • Jun Komachi for "Scientific Method for Image Quality Improving"
  • Masaki Sakakibara for "Development and Improvement of Pixel-Parallel 14-bit ADC for CMOS Image Sensor"
  • Daniel Van Nieuwenhove for "3D ToF (Time of Flight) Sensor and System Used in Cars and Mobile Applications"

Saturday, November 23, 2019

SET Releases 1um-accurate Hybrid/Direct Bonding Machine

SET, Smart Equipment Technology announces the release of NEO HB, an automatic flip-chip bonder designed for ± 1 µm 3σ post-bonding accuracy, in stand-alone or full automatic mode (EFEM). NEO HB is suitable for direct hybrid bonding processes.

The first of a new line of SET flip-chip bonders dedicated entirely to production, the tool combines high precision, flexibility, short cycle time, and creative design. It was developed in collaboration with CEA-Leti as part of IRT Nanoelec’s 3D integration program.

SET joined IRT Nanoelec in 2016 with the goal to develop a brand-new tool for direct-bonding applications that delivered high accuracy and high throughput, and a high level of cleanliness,” said Pascal Metzger, CEO of SET. “That ambition required a strong collaboration among experts from different disciplines. Today, SET’s team is proud to commercially launch NEO HB, which meets the initial technical targets and will address development and production needs for tomorrow’s chips.

Friday, November 22, 2019

Espros on ToF Camera Calibration

Espros distributors Pacer (UK) and Aprizes (China) publish Espros application notes on ToF camera calibration. Almost everything affects the ToF measurements, some factors have quite a dramatic influence:

The main error sources which affect the accuracy of distance measurement are:
  • Distance response non-uniformity DRNU of the sensor
  • Temperature drift
  • Ambient light
  • The magnitude of the signal amplitude
Under the term DRNU, we treat all factors that lead to a different distance reading between any of the pixels in the pixel-field looking to the inside of a sphere. These factors are sensor/camera related and include:
  • Flat-field error of the pixel-field
  • Column A/D converter differences
  • Row addressing differences
  • Fixed-pattern noise caused by manufacturing tolerances
  • 4th order harmonics distortion of the demodulation algorithm

Another Espros presentation gives more info on ToF error sources: