Wednesday, February 19, 2020

Panasonic Develops 1MP APD-based ToF Sensor with 250m Range

Panasonic has developed a TOF image sensor that uses APD pixels and is capable of acquiring highly accurate 3D information at distances up to 250 m. The applications of the new sensor include automotive range imaging and wide-area surveillance.

The new sensor has 1MP resolution and depth accuracy of 10cm at the distances from 10m to 100m. This is an improvement over the previous generation Panasonic APD sensor announced in June 2018 that had an accuracy of 1.5m.

OmniVision Announces Solution to Shortage of 2MP Image Sensors

PRNewswire: OmniVision announces a 2M image sensor OV02B manufactured using 12ʺ wafers, instead of the 8ʺ wafers that are in tight supply but are typically used for 2MP sensors. The OmniPixel3-HS pixel technology provides the OV02B with a 1.75um pixel pitch in a 1/5ʺ optical format.

"The strong growth trend in smartphone multicameras that we saw in 2019, for both main and front-facing cameras, is continuing to accelerate in 2020. In the entry level and mainstream markets, smartphone camera designers favor 2MP image sensors to produce bokeh effects, as they provide a significant cost advantage over higher resolution sensors," said Parson Li, OmniVision's senior mobile product marketing manager. "While the demand for 2MP image sensors is growing, there is a shortage of the 8ʺ wafers used to produce them. Our new OV02B is built on 12ʺ wafers while maintaining a die size that is comparable to our existing 2MP sensors, offering an effective alternative for cost sensitive entry level and mainstream smartphones."

Prophesee and Sony Develop a Stacked Event-Based Vision Sensor with the Industry’s Smallest Pixels and Highest HDR Performance

Prophesee S.A. and Sony announce they have jointly developed a stacked Event-based vision sensor with the industry’s smallest 4.86μm pixel size and the industry’s highest 124dB (or more) HDR performance. This sensor combines of Sony’s stacked CMOS sensor process with Cu-Cu connections, with Prophesee’s Metavision Event-based vision technologies leading to fast pixel response, high temporal resolution and high throughput data readout. The newly developed sensor is suitable for various machine vision applications, such as detecting fast moving objects in a wide range of environments and conditions.

The 1/2-inch format sensor has 1280x720 resolution and uses 40nm logic process. The 124dB (or more) HDR performance is made possible by placing only BSI pixels and a part of N-type MOS transistor on the pixel chip (top), thereby allowing the aperture ratio to be enhanced by up to 77%. High sensitivity/low noise technologies Sony has developed over many years of CMOS image sensor development enable event detection in low-light conditions (40mlx).

By adding time information at 1μs precision to the pixel address where a change in luminance has occurred, event data readout with high time resolution is ensured. Furthermore, a high output event rate of 1.066Geps*5 has been achieved by efficiently compressing the event data, i.e. luminance change polarity, time, and x/y coordinate information for each event.

TowerJazz Updates on its CIS Business

SeekingAlpha transcript of TowerJazz Q4 2019 earnings call updates on the foundry's image sensor business:

"Moving to our Sensors Business unit, despite in organic revenue decline of about 20% in the industrial sensor market, predominantly a consequence of the trade war, we were able to compensate to great extent, to have a decrease of 4% year-over-year organic revenues. The set compensation was via the growth of our X-ray medical sensors market and our high-end visible camera market. This growth should continue in 2020 and with an expected recovery and industrial sensor market, we target a double-digit organic growth in this business in 2020.

2019 was an exciting year for our future both in state-of-the-art technology developments and in customer engagements. As announced, we have released our 300 millimeter back side illumination hybrid bonding stack way for technology with copper to copper electrical contacts, and a pitch smaller than 2.5 micron, the smallest in the world. This technology allows a connection of a BSI sensor to a CMOS logic and analog wafer at the pixel level. We won two major customers that are using this technology for the mobile time of flight market both for face recognition and front looking 3D application.

These products will grow into mass volume production in 2022. The same technology will be used with our existing customers for high end photography market both in high end DSLR and mirrorless cameras and in cinematography.

In addition, we engage with large optical fingerprint sensor providers on the development of under OLED and under LCD sensors utilizing our high performing CIS technologies and our 200 -millimeter fabs at the point when eight micron technology node. These products are expected to wrap in the second half of this year and to further grow to high volumes in 2021 and beyond.

Machine Vision Helps to Contain Coronavirus

New China TV video shows how camera-equipped robots help in fighting with the coronavirus outbreak in China:

Tuesday, February 18, 2020

OmniVision Announces Its First 64MP, 0.801um CMOS Sensor

PRNewswire: OmniVision announces the OV64C, its first 64MP image sensor featuring a 0.801um pixel size for rear-facing smartphone cameras in a 1/1.7" optical format. Built on OmniVision’s PureCel Plus stacked die technology, the new sensor features 4-cell remosaic for full resolution Bayer output as well as digital crop zoom, and a CPHY interface. In low light conditions, this sensor can use near-pixel binning to output a 16 MP image with 4X the sensitivity, offering 1.6 um equivalent performance for previews and still captures.

TSR estimates there will be 127 million image sensors with 64 MP or higher resolution shipped to smartphone manufacturers in 2020,” said Arun Jayaseelan, staff marketing manager at OmniVision. “The OV64C, with its premium resolution and features, is well positioned to address this ramp in demand among high end smartphone designers.

The sensor features type-2, 2x2 microlens phase detection autofocus (ML-PDAF) to boost autofocus accuracy, especially in low light. Output formats include 64 MP at 15 fps, 8K video at 30 fps, 16 MP captures with 4-cell binning at 30 fps, 4K video at 60 fps and 4K video with EIS at 30 fps. Additionally, the OV64C supports 3-exposure, staggered HDR timing for up to 16 MP video modes.

Samples of the OV64C image sensor are available now.

125M fps Sensor

MDPI Special issue on the 2019 International Image Sensor Workshop (IISW2019) publishes a paper "Over 100 Million Frames per Second 368 Frames Global Shutter Burst CMOS Image Sensor with Pixel-wise Trench Capacitor Memory Array" by Manabu Suzuki, Yuki Sugama, Rihito Kuroda, and Shigetoshi Sugawa from Tohoku University, Japan.

"In this paper, a prototype ultra-high speed global shutter complementary metal-oxide-semiconductor (CMOS) image sensor with pixel-wise trench capacitor memory array achieving over 100 million frames per second (fps) with up to 368 record length by burst correlated double sampling (CDS) operation is presented. Over 100 Mfps high frame rate is obtained by reduction of pixel output load by the pixel-wise memory array architecture and introduction of the burst CDS operation which minimizes the pixel driving pulse transitions. Long record length is realized by high density analog memory integration with Si trench capacitors. A maximum 125 Mfps frame rate with up to 368 record length video capturing was confirmed under room temperature without any cooling system. The photoelectric conversion characteristics of the burst CDS operation were measured and compared with those of the conventional CDS operation."

Monday, February 17, 2020

Coronavirus and Image Sensor Companies

Sony Semiconductor Solutions announces the measures to ensure the safety and health of its customers, business partners and Sony Group employees and to prevent further spread, such as prohibition of all overseas business trips or working from home for those who have just returned from China:

"we would like our customers and business partners who have traveled to China to refrain from entering any Sony’s office areas for the next 14 days after the immigration into Japan. In addition, when we meet with any customers or business partners, regardless of where we meet, please allow us to make sure whether those people have visited China within the last 14 days," says Sony.

Smartsens reports that "as of now, there is no infected or suspected of being infected employees of Smartsens. "On the supply side product, Smartsens still provides normal supply. However, due to strict logistics control in many places due to epidemic prevention needs, the timeliness of product logistics may be affected to a certain extent.

At the same time, in order to reduce the concentration of personnel and prevent the epidemic from spreading further, we will appropriately adjust the arrangements for corporate offline market activities and participation in third-party offline market activities in the first half of 2020.

Solid-State Supplies publishes Omnivision's letter to customers from Feb. 3, 2020:

Update: TrendForce publishes a forecast on coronavirus impact on electronic industry:

Silicon Optronics 2018 Report

Taiwan-based Silicon Optronics Inc. (SOI) rarely publishes English info about its business. A translation of the company's 2018 annual report is an exception. Few quotes:

"In the past two years, the image sensor products for surveillance were the main product lines of SOI. We continue to research and develop new application of relevant products to expand the market and to gain more addon values, such as car electronics, drone camera(UAV), industrial robot, etc.

The revenue of SOI was NT$2,034,267,000 in 2018, which increases 19% compared with 2017. The total sales volume also increased more than 20%. In 2018, the net profit after tax was NT$157,432,000, which is 23% decrease than 2017. Due to extreme competition of image sensors in the surveillance market, resulting in the decrease in net profit after tax, compared with the previous year.

Sunday, February 16, 2020

Switchable NIR to Visible Organic Photodetector

Science Magazine publishes a paper "Near-infrared and visible light dual-mode organic photodetectors" by Zhaojue Lan, Yanlian Lei, Wing Kin Edward Chan, Shuming Chen, Dan Luo, and Furong Zhu from Hong Kong Baptist University and Southern University of Science and Technology, Shenzhen, China.

"We report a dual-mode organic photodetector (OPD) that has a trilayer visible light absorber/optical spacer/near-infrared (NIR) light absorber configuration. In the presence of NIR light, photocurrent is produced in the NIR light–absorbing layer due to the trap-assisted charge injection at the organic/cathode interface at a reverse bias. In the presence of visible light, photocurrent is produced in the visible light–absorbing layer, enabled by the trap-assisted charge injection at the anode/organic interface at a forward bias. A high responsivity of higher than 10 A/W is obtained in both short and long wavelengths. The dual-mode OPD exhibits an NIR light response operated at a reverse bias and a visible light response operated at a forward bias, with a high specific detectivity of ~10^13 Jones in both NIR and visible light ranges. A bias-switchable spectral response OPD offers an attractive option for applications in environmental pollution detection, bioimaging process, wellness, and security monitoring in two distinct bands."

Yole Market Monitor

Yole Developpement publishes a sample of its quarterly CIS market monitors with interesting data showing the scale of image sensor market now:

8-tap ToF Pixel

MDPI paper "An 8-Tap CMOS Lock-In Pixel Image Sensor for Short-Pulse Time-of-Flight Measurements" by Yuya Shirakawa, Keita Yasutomi, Keiichiro Kagawa, Satoshi Aoyama, and Shoji Kawahito from Shizuoka University and Brookman, Japan, is a part of Special issue on the 2019 International Image Sensor Workshop (IISW2019).

"An 8-tap CMOS lock-in pixel image sensor that has seven carrier-capturing and a draining time window was developed for short-pulse time-of-flight (TOF) measurements. The proposed pixel for the short-pulse TOF measurements has seven consecutive time-gating windows, each of which has the width of 6 ns, which is advantageous for high-resolution range imaging, particularly for relatively longer distances (>5 m) and under high ambient light operations. In order to enhance the depth resolution, a technique for the depth-adaptive time-gating-number assignment (DATA) for the short-pulse TOF measurement is proposed. A prototype of the 8-tap CMOS lock-in pixel image sensor is implemented with a 1POLY 4METAL 0.11-μm CIS process. The maximum non-linearity error of 1.56% FS for the range of 1–6.4 m and the depth resolution of 6.4 mm was obtained at 6.2 m using the DATA technique."

Saturday, February 15, 2020

Paper on CMOS Sensor Evolution

International Journal on Smart Sensing and Intelligent Systems publishes a paper "On Evolution of CMOS Image Sensors" by Luiz Carlos Paiva Gouveia (University of Glasgow) and Bhaskar Choubey (University of Oxford), UK.

"CMOS Image Sensors have become the principal technology in majority of digital cameras. They started replacing the film and Charge Coupled Devices in the last decade with the promise of lower cost, lower power requirement, higher integration and the potential of focal plane processing. However, the principal factor behind their success has been the ability to utilise the shrinkage in CMOS technology to make smaller pixels, and thereby have more resolution without increasing the cost. With the market of image sensors exploding courtesy their integration with communication and computation devices, technology developers improved the CMOS processes to have better optical performance. Nevertheless, the promises of focal plane processing as well as on-chip integration have not been fulfilled. The market is still being pushed by the desire of having higher number of pixels and better image quality, however, differentiation is being difficult for any image sensor manufacturer. In the paper, we will explore potential disruptive growth directions for CMOS Image sensors and ways to achieve the same."

IDTechEx on Trends in Automotive Lidars

Autosens publishes IDTechEx article with a review of Espros, SiLC, XenomatiX, Blickfeld, and Outsight LiDAR approaches.

Friday, February 14, 2020

Pixel-Linearizing Ramp for SS ADC

MDPI paper "A Highly Linear CMOS Image Sensor Design Based on an Adaptive Nonlinear Ramp Generator and Fully Differential Pipeline Sampling Quantization with a Double Auto-Zeroing Technique" by Chuangze Li, Benguang Han, Jie He, Zhongjie Guo, and Longsheng Wu from Xi’an Microelectronic Technology Institute, Xi dian University, and Xi`an University of Technology, China, presents a couple of ideas on pixel response linearization:

"The in-pixel source follower transistor and the integration capacitor on the floating diffusion node cause linearity degradation. In order to address this problem, this paper proposes an adaptive nonlinear ramp generator circuit based on dummy pixels used in single-slope analog-to-digital converter topology for a complementary metal-oxide-semiconductor (CMOS) image sensor. In the proposed approach, the traditional linear ramp generator circuit is replaced with the new proposed adaptive nonlinear ramp generator circuit that can mitigate the nonlinearity of the pixel unit circuit, especially the gain nonlinearity of the source follower transistor and the integration capacitor nonlinearity of the floating diffusion node. Moreover, in order to enhance the frame rate and address the issue of high column fixed pattern noise, a new readout scheme of fully differential pipeline sampling quantization with a double auto-zeroing technique is proposed. Compared with the conventional readout structure without a fully differential pipeline sampling quantization technique and double auto-zeroing technique, the proposed readout scheme cannot only enhance the frame rate but can also improve the consistency of the offset and delay information of different column comparators and significantly reduce the column fixed pattern noise. The proposed techniques are simulated and verified with a prototype chip fabricated using typical 180 nm CMOS process technology. The obtained measurement results demonstrate that the overall nonlinearity of the CMOS image sensor is reduced from 1.03% to 0.047%, the efficiency of the comparator is improved from 85.3% to 100%, and the column fixed pattern noise is reduced from 0.43% to 0.019%."

Signal Synchronization in 225MP Stitched Sensor

Japan IEICE Electronics Express paper "A synchronous driving approach based on adaptive delay phase-locked loop for stitching CMOS image sensor" by Zhongjie Guo, Ningmei Yu, and Longsheng Wu from Xi’an University of Technology and Xi’an Microelectronic Technology Institute, China, proposes signal delay compensation circuit for long connections in a large sensor.

"A synchronous driving approach for stitching CMOS image sensor is proposed. Dual row signal line driving architecture must be considered in the design of large array CMOS image sensor. However, as the size of the array increases further, the traditional synchronization technologies such as clock tree cannot be applied because of the stitch technology, Furthermore, this invalidity will cause DC shoot through and dead line. Based on the adaptive delay phase-locked loop, dual row signal line synchronous driver for pixel array is realized in a single die CMOS image sensor with 225M pixels and large area of 120×120mm2. Timing matching improves by two orders of magnitude, and 99.95% consistency is achieved."

Thursday, February 13, 2020

TSR Market Data

PulseNews publishes a recent TSR market data: "The world’s image sensor market is estimated to grow to $27 billion by 2023 from $17.2 billion in 2019, according market research firm Techno Systems Research (TSR). In the market, Sony took up the lion’s share of 49.1 percent, much bigger than 17.9 percent of Samsung Electronics."