Saturday, November 18, 2017

New Omnivision CEO Opens Patent War in China

Omnivision board of directors appointed a new CEO - Yu Renrong. Yu Renrong was born in 1966, has Chinese Nationality, no permanent residence abroad, Bachelor’s degree. Yu has graduated in 1990 from the Department of Radio, Tsinghua University, Beijing and has been involved into management of various companies since 1998.

Omnivision and Spreadtrum co-founder Datong (David) Chen has been appointed Chairman of the Board. The company's former CEO and Chairman Shaw Hong now becomes Chairman Emeritus and Chairman of OVT Strategic Development Committee.


IFNews, EEWorld, asmag, IPR: The company files two lawsuits against SmartSens claiming that its security-aimed SC5035 image sensor infringes on Omnivision's Chinese patent ZL200510052302.4.

According to iKnow site, the ZL200510052302.4 is actually a patent family:


Similarly to Omnivision's Nyxel announcement, StartSens too says it has improved IR sensitivity in its SC5035 sensor, but has announced this 6 months earlier, on April 18, 2017:

"SmartSens Technology's near-infrared enhancement is due to its new pixel structure. In the new structure, the electron capture region of each pixel is extended to more fully capture the electrons generated by the near-infrared band photons. This special pixel structure makes the photoelectric conversion efficiency of the near infrared band more than doubled compared with the original technology. At the same time, the new structure of the adjacent photodiode do a deep isolation, reducing the crosstalk between pixels, improve image clarity.

The 5-megapixel SC5035 is the first device in the SmartSens Technology CMOS image sensor lineup with the new technology, and its near-infrared (NIR) band is twice as susceptible to existing products. In the current security monitoring, machine vision and intelligent transportation systems and other applications, the night infrared fill light wavelengths concentrated in the 850nm ~ 940nm near infrared band. So the sensitivity of the near infrared band to enhance, can greatly enhance the product's night vision effect.
"

SmartSens graph shows 940nm QE of ~30% in 2um pixel, while Omnivision Nixel achieves 40% QE in 2.8um pixel:


SC5035 flyer is available on-line:


Other than SC5035, SmartSens has quite a broad lineup of sensors for security and surveillance applications:

Friday, November 17, 2017

SystemPlus Reveals that iPhone X IR Imager is SOI-based

EETimes publishes Junko Yoshida's article based on Yole Developpement and SystemPlus Consulting analysis of Apple iPhone X TrueDepth design. The biggest surprise is that ST IR imager is using SOI process, said to be the first such sensor in mass production:

SystemPlus and Yole "deduced that silicon-on-insulator (SOI) wafers are being used in near-infrared (NIR) imaging sensors. They noted that SOI has played a key role in improving the sensitivity of NIR sensors — developed by STMicroelectronics — to meet Apple’s stringent demands.

Pierre Cambou, activity leader for imaging and sensors at Yole Développement, called the SOI-based NIR image sensors “a very interesting milestone for SOI.”

Apple’s adoption of ST’s NIR sensors marks the debut of SOI in mass production for image sensors, noted Cambou. “Image sensors are characterized by large surface due to the physical size of light. Therefore, this is a great market to be in for a substrate supplier” like Soitec, he added.

Yole and System Plus Consulting found inside ST’s NIR sensor “the use of silicon-on-insulator (SOI) on top of deep-trench isolation (DTI).” DTI is deployed to prevent leakage between photodiodes. Apple reportedly etched literal trenches between each one, then filled the trenches with insulating material that stops electric current.

Optically speaking, Cambou explained that SOI wafers are advantageous because the insulator layer functions like a mirror. “Infrared light penetrates deeper, and it reflects back to the active layer,” he noted. Electrically speaking, Cambou noted, SOI improves NIR’s sensitivity largely because it’s good at minimizing leakage within the pixel. The improved sensitivity provides good image contrast.

Asked if ST’s NIR sensors are using FD-SOI or SOI wafers, Cambou said that the research firms couldn’t tell.

Asked about surprises unearthed by the teardown, Cambou cited the size of ST’s NIR sensor chip. It measures 25mm2, and has only 1.4 megapixels due to the large 2.8-μm pixel size.


Google Applies for RGB-Z Sensor Patent

Google patent application US20170330909 "Physical Layout and Structure of RGBZ Pixel Cell Unit For RGBZ Image Sensor" by Chung Chun Wan and Boyd Albert Fowler is a continuation from PCT filing of WO/2016/105664 in 2014. The application proposes a 5T pixel for ToF imaging intermixed with 4T or 5T RGB pixels:

Thursday, November 16, 2017

Perovskite Materials for Foveon-like Pixels

Optics.org: A group of researchers from Empa and ETH Zurich publish a paper in Nature called "Non-dissipative internal optical filtering with solution-grown perovskite single crystals for full-colour imaging" by Sergii Yakunin, Yevhen Shynkarenko, Dmitry N Dirin, Ihor Cherniukh & Maksym V Kovalenko. The crystals of semiconducting methylammonium lead halide perovskites (MAPbX3, where MA=CH3NH3+, X=Cl−, Br− and Br/I−) are used as absorbers for full-color Foveon-like stacked imaging:

(a) Bayer color sensor design. (b) Vertically stacked color sensor design.
(c) Schematic of the crystal structure of hybrid perovskites
— materials with high optical absorption, efficient charge transport, and
bandgap tunability. (d) Photograph of (from left to right) typical MAPbCl3,
MAPbBr3 and MAPb(Br/I)3 single crystals. (e) Measured light absorption
of each perovskite SC used in a stack.
(a) Sketch of stacked SC photodetector.
(b) Photograph of the prototype detector assembled from three SCs
stacked on a chip carrier. (c) Normalized photoconductivity spectra
of the individual SCs in the stacked detector presented in b.

Embedded Image and Vision Processing

Yole Developpement report on Embedded Image and Vision Processing says:

"The image signal processor (ISP) market offers a steady compound annual growth rate (CAGR) of 6.3%, making the total market worth $4,400M in 2017. Meanwhile, the vision processor market is exploding, with a 30.7% CAGR and a market worth $653M in 2017!

The main goal of this report is to understand what is happening with the emergence of AI. Even if it is not a new technology, thanks to technological factors AI has made a spectacular entry into vision systems.

The AI market is therefore expected to reach $35B in 2025 with an estimated CAGR at 50% per year from 2017-2025.
"

Wednesday, November 15, 2017

Sony Proposes 1D Curved Sensor for Copy Machines

Sony patent application US20170323915 "Semiconductor device and method of manufacturing the same, semiconductor module, and electronic device" by Kiyohisa Tanaka finds another application for curved sensors - improving the resolution of copy machines and document scanners. The big advantage of this application is that it should not support optical zoom:

More about Sony 7.42MP Automotive Sensor

Nikkei publishes a 4-page article on Sony 1/1.7-inch IMX324 ADAS sensor. Sony says "We will sell the product with intent to achieve 100% share (of the market for image sensors designed for sensing cameras to be attached to the front side of vehicle)."

The main points are:

  • Its power consumption at full 7.42MP resolution 40fps is 500-600mW, which is the industry's smallest, according to Sony.
  • The new sensor has the highest sensitivity in the industry and is the industry's first automotive image sensor that features security functions, Sony said.
  • Sony started to contact Mobileye from an early stage of the development of the new product and responded to many demands of Mobileye.
  • However, the new product was developed not only for Mobileye. The specifications required by Mobileye are "commonly-required specifications," Sony said.
  • Sony is to ship samples in November 2017 and to start volume production in June 2018.
  • Sony uses a laminated stacked design, the first laminated-type automotive image sensor, the company said. "We applied a process that is two or three generations more advanced that the processes used for existing automotive image sensor products."
  • Sony improved the sensitivity by using an RCCC CFA. Image recognition is possible with Mobileye's without using all of the RGB colors.

Tuesday, November 14, 2017

Newsight Imaging and LeiShen Intelligent Partner to Deliver "a Game Changing Automotive LiDAR"

BusinessWire: Newsight Imaging announces a partnership with LeiShen Intelligent to deliver V-LiDAR, a 3D pulsed LiDAR for automotive applications. Newsight's patent-pending eTOF (Enhanced Time-of-Flight) bridges the gap between short-distance iTOF and the 200m distance automotive requirement by extending the DR while retaining high accuracy.

Design of the V-LiDAR is the result of close collaboration between LeiShen and Tier-1 and Automotive OEMs. It is real solid-state (no moving parts, No MEMS), high resolution (VGA and above), with range and accuracy that meet the automotive industry definition, and with the appropriate ISO certifications.

LeiShen Intelligent has long valued core technologies and is committed to delivering advanced LiDAR systems. The V-LiDAR™ performs well on distance, speed and reliability measures. It will be a revolutionary product with excellent performance and low costs. The program will constitute a good example of cooperation between Chinese and Israeli companies,” said Bernie Hu, CEO of LeiShen.

"The Newsight-LeiShen partnership creates a very strong brand positioning in the automotive market," said Eli Assoolin, CEO of Newsight Imaging: "Newsight's proven capability of creating very advanced and sensitive integrated CMOS Sensors, together with LeiShen’s exceptional knowledge and experience in LiDAR design, will surely make this product highly attractive for a growing number of automotive makers, offering "best in class" implementation of their requirements, such as range, real solid-state, accuracy, power and price."

Bloomberg: Apple Plans ToF Rear Camera in 2019 iPhone

According to Bloomberg sources, Apple is working on a rear-facing ToF 3-D sensor for the iPhone in 2019, primarily targeting AR applications.

More about Omnivision Nyxel Technology

EEJournal, ElectronicDesign publish more explanations about how Omnivision Nyxel IR technology works:

"The Nyxel technology adds three pieces to the puzzle. The first is increasing the thickness of the silicon, which allows the photons to travel further in the pixel cell and enables more electron to photon conversion hence a brighter image. The second is essentially putting each cell into its own deep trench with barriers between cells to avoid photon travel to the neighboring pixels and prevent crosstalk. The other is to add a layer on the surface that absorbs [scatters] the maximum amount of light. This combination provides a longer path, allowing the sensor to detect more photons and improve the overall performance of the system."


There is also a Chinese-language article on EDNChina site adding some numbers to the story:

"Now that we have a 50% market share in the security market, security products last year accounted for about 20-25% of the company's total revenues, its growth rate is much higher than the phone," OmniVision VP of China Chen Jiawang said.

"We increased the silicon layer from 4 microns to 6 microns, absorbing more photons, converting to more electrical signals and improving imaging efficiency," explained Chen Jiawang.

The technology has been successfully deployed on 12-inch wafers, while 8-inch wafers are said to be unusable.

Update: Vision Systems Design article quotes Boyd Fowler, Omnivision CTO, explaining the technology details:

"One significant change was doubling the epitaxial layer thickness from about 3 to 6 microns.

When the electrons are generated in the substrate, they need to be collected. This DTI makes sure these electrons can't easily move from the pixel where they are generated to an adjacent pixel, which is critical for effective isolation and enables higher sensitivity, without compromising spatial resolution.

Perhaps most important to the new process is careful management of wafer surface texture to scatter the light as it enters the pixel. By scattering the light, the photons must travel a significantly longer path length.

In this case, the straight path length has been extended from about 3 or 4 microns maximum in our legacy design, to a scattered path of up to 10 or 20 microns with the Nyxel technology.

In the past people have tried to develop better NIR technology, but it was almost always a tradeoff between higher sensitivity and spatial resolution. This technology enables us to give the customer both at the same time.

OmniVision is currently sampling this experimental 2MP Nyxel technology-based product to demonstrate the proof of concept, and has also launched a 5MP product in the security market in October of this year. For 2018, the company has a slew of various resolution Nyxel-based products on the roadmap for the security market throughout Q1 and Q2, and very quickly after that will be looking at products for the machine vision market, AR/VR, automotive and medical applications.
"

Update #2:
BDTI too publishes an article on Nyxel principles, based on a talk with Lindsay Grant, Omnivision VP of Process Engineering.