Saturday, April 25, 2015

Wikileaks on Sony Next Gen Cinematic Cameras

Wikileaks has published a number of stolen Sony Pictures documents, some of them talking about cinematic cameras image sensor development. The undated "Next Generation Camera" talks about Red camera threat and a development of the new 8K image sensor with modified Bayer pattern and HDR:

No details on next generation CFA pattern is given. A leaked 2011 document talks about the older Q67 pattern that Sony has been using in its CineAlta cameras since 2010. Another leaked 2011 Sony document talks about a workflow based on the F65 camera:

According to yet another Sony 2011 document on the next generation cameras, it looks like global shutter is placed high in the list of the sensor requirements.

Friday, April 24, 2015

Eye-Tracking Tech Company Tobii Valued $244M at IPO Stockholm, Sweden-based eye-tracking technology company Tobii IPO today gives it a market cap of SEK 2.1 billion (about $244M). Tobii says the offering was over-subscribed multiple times. Tobii will receive gross proceeds of approximately SEK 400 million ($46.5M) through the issue of new shares as part of the IPO, before a possible exercise of the over-allotment option.

The company has about 570 employees across its offices in Sweden, the US, China, Germany and other countries.

Pentax DSLR Features Pixel Shift Demosaic

Imaging Resource: New Pentax K-3 II DSLR features Ricoh pixel shift resolution enhancement that removes the need for Bayer demosaicing, first presented at CP+ a month ago.

Pentax IS actuator shifts the sensor by 1 pixel in 4 directions. "The result is an image which has full color information at every pixel location -- and thus improved resolution and a greater resistance to false color artifacts -- but only a relatively modest increase in file size...

As an added bonus, images shot in the Pixel Shift Resolution mode should also have a cleaner, tighter noise pattern. The reason for this is twofold. First, since multiple exposures are involved, noise can be averaged out across those exposures. Secondly, in a Bayer-filtered sensor, two out of three colors at each pixel location must be interpolated (read: guessed) from the values of surrounding pixels. When that happens, noise from adjacent pixels is likewise spread across their neighbors, resulting in a less film-like and blotchier, more objectionable noise pattern. With full color information at each pixel, a Pixel Shift Resolution shot's high ISO grain pattern is finer, and we're guessing easier to clean up post-capture, too.

Pentax Youtube video calls this mode "Pixel Shift Resolution". It's somewhat similar to one appeared in the previous Pentax DSLR model, but then it used to be a high frequency 500Hz vibration, whereas now it's said to provide a higher resolution for static objects:

Galaxycore Ranked High Among China Semiconductor Companies

PWC report "A decade of unprecedented growth: China’s impact on the semiconductor industry, 2014 update," dated by January 2015, ranks Galaxycore #10 on revenue basis among Chinese semiconductor companies. Other image sensor vendors in China, such as Superpix and Brigates have not make it even in the list of 50 largest companies.

Nomura report "Greater China Semi" places Galaxycore at #8 among semiconductor design houses in China:

Thursday, April 23, 2015

Ziptronix Lost Lawsuit Against Omnivision and TSMC

Finnegan: Ziptronix has lost its 2010 lawsuit against Omnivision and TSMC on infringement on its 9 patents on direct wafer bonding.

"In Ziptronix, Inc. v. OmniVision Technologies, Inc. a Taiwanese contract manufacturer and its U.S. subsidiary moved for summary judgment of no infringement because the allegedly infringing activity occurred only in Taiwan, with the exception of negotiations and contracting in the United States. The district court granted summary judgment, finding that even if negotiation and contracting occurred in the United States, there could be no direct infringement under U.S. patent law because the contracts contemplated delivery and performance to take place solely abroad. Additionally, the patent holder failed to present evidence that the Taiwanese manufacturer's customer, OmniVision, committed an underlying act of direct infringement. Thus, the court concluded, the Taiwanese manufacturer and its U.S. subsidiary did not commit or induce infringing acts "within the United States."

For those who skilled in legal language and logic, the full text of California Court summary judgement from Oct. 21, 2014 can be downloaded here. More discussions on patent law gray areas, apparently involved in this case, can be found in another Finnegan article.

8K UHDTV Adoption Milestones

Ikegami has collaborated NHK to develop an 8K UHDTV camera, the "SHK-810", and achieved significant size reduction and light-weight design for field and live production, which can be operated at the same level as the current broadcast camera systems. The camera employs a single 33MP Super 35 CMOS sensor, achieving 4,000TVL horizontal and vertical resolution. The color filter on the sensor uses the dual-green SHV color arrangement.

According to the roadmap of Japan Ministry of Internal Affairs and Communications (MIC), test-broadcast of 4K/8K by BS satellite television will start in Rio 2016 Olympic and Paralympic Games, and 8K on-air broadcast will start as soon as possible by 2018 in Japan. The 4K/8K broadcasting is targeted at the Tokyo 2020 Olympic and Paralympic Games. Per MIC, by the year 2020, 4K/8K broadcasting should be shared by public viewing points in Japan, and 4K/8K television sets should be widespread in the consumer market by that time.

Ikegami SHK-810

Wednesday, April 22, 2015

Sony Ups its Profit Forecast

WSJ, Bloomberg: Sony revises upward its profit forecast for its fiscal year ended on March 31, 2015. One of the reasons for revision is higher than expected image sensor sales. The final yearly results will be reported on April 30.

The demand for front-facing camera modules is going through the roof, because everyone wants to take high-quality selfies, and that doubles the market size for Sony,” said Amir Anvarzadeh, a manager of Japanese equity sales at BGC Partners Inc. in Singapore. “The auto segment of the market is also beginning to boom. Cars potentially may have more than five modules per car.

Sharp Presents High End Sensors

Sharp's March 2015 catalog reveals new high end products. The company presents RJ5DY1BA0LT, a 1-inch 13MP CMOS sensor capable of 4K 60fps video:

One can also buy an off-the-shelf 21MP camera module with 4K 30fps video and F2.0 lens:

Also, Sharp greatly expands its CCD product line, announcing no less than 19 new CCDs, and another 4 marked "under development."

Tuesday, April 21, 2015

Image Sensors at 2015 VLSI Symposia

VLSI Symposia to be held in June 2015 in Kyoto, Japan publishes its advance program. Few notable papers on image sensors:

VLSI Circuit Symposium has 5 image sensor papers. Probably, the most interesting one comes from Olympus:

A 3D Stacked CMOS Image Sensor with 16Mpixel Global-Shutter Mode and 2Mpixel 10000fps Mode Using 4 Million Interconnections
T. Kondo, Y. Takemoto, K. Kobayashi, M. Tsukimura, N. Takazawa, H. Kato, S. Suzuki, J. Aoki, H. Saito, Y. Gomi, S. Matsuda and Y. Tadaki, Olympus, Japan

A 16Mpixel 3D stacked CMOS image sensor with pixel level interconnections using 4,008,960 micro bumps at a 7.6μm pitch, which set no layout restriction and causes no harm to sensor characteristics, was developed to achieve both a 16Mpixel global-shutter mode with a -180dB PLS and 2Mpixel 10000fps high speed image capturing mode.

The second most interesting paper is one from Tohoku University:

A Linear Response Single Exposure CMOS Image Sensor with 0.5e- Readout Noise and 76ke- Full Well Capacity
S. Wakashima, F. Kusuhara, R. Kuroda and S. Sugawa, Tohoku Univ., Japan

A linear response single exposure CMOS image sensor approaching to the photon countable sensitivity and a high full well capacity is developed using lateral overflow integration capacitor architecture with dual gain column amplifiers, small floating diffusion capacitance and low noise in-pixel source follower signal readout technologies. The fabricated 5.5 um pitch 360H x 1680V pixel prototype image sensor exhibited 240 μV/e- conversion gain with 76 ke- FWC resulting in 0.5 erms readout noise and 104 dB dynamic range under room temperature operation.

Image Sensor/Digital Logic 3D Stacked Module Featuring Inductive Coupling Channels for High Speed/Low-Noise Image Transfer
M. Ikebe*, D. Uchida*, Y. Take**, M. Someya*, S. Chikuda*, K. Matsuyama*, T. Asai*, T. Kuroda** and M. Motomura*, *Hokkaido Univ. and **Keio Univ., Japan

This paper proposes 3D stacked module consisting of image sensor and digital logic dies connected through inductive coupling channels. Evaluation of a prototype module revealed radiation noise from the inductive coils to the image sensor is less than 0.4-LSB range along with ADC code, i.e., negligible. Aiming at high frame rate image sensor/processing module exploiting this attractive off-die interface, we also worked on resolving another throughput-limiter, namely power consuming TDC used in column parallel ADCs. Novel intermittent TDC operation scheme presented in this paper can reduce its power dissipation 57% from conventional ones.

A 0.66e-rms Temporal-Readout-Noise 3D-Stacked CMOS Image Sensor with Conditional Correlated Multiple Sampling (CCMS) Technique
S.-F. Yeh, K.-Y. Chou, H.-Y. Tu, C. Y.-P. Chao and F.-L. Hsueh, TSMC, Taiwan

A conditional correlated multiple sampling (CCMS) technique for low noise CMOS image sensor (CIS) is proposed to reduce noise and address low frame rate issue caused by the conventional correlated multiple sampling (CMS) technique. An 8Mpixel 3D-stacked CIS with 1.1um pixel pitch is designed and verified. Measurement results show this technique can achieve 0.66erms at 36.1 kHz A/D sampling rate per pixel with analog gain at 16 and 5-times multiple sampling. The resulting DNL is within -0.49/+0.45LSB.

A 0.4V Self-Powered CMOS Imager with 140dB Dynamic Range and Energy Harvesting
A. Y.-C. Chiou and C.-C. Hsieh, National Tsing Hua Univ., Taiwan

This PWM imager operates at a lowest reported supply 0.4V with a 0.42x smaller pixel size, 1.5x larger fill factor, 0.58 smaller random noise, and 3x better iFoM than previous work. With proposed dual-exposure extended-counting (DEEC) scheme, the prototype achieves a high dynamic range of 140dB with a 58dB boost. Optical energy harvesting (OEH) design is implemented to generate 60.3pW per lux per mm2 and 1.28x higher efficient than current design. A self-powered imager is demonstrated with 15fps under 100klux.

VLSI Technology Symposium has one image sensor paper:

Energy Efficient 1-Transistor Active Pixel Sensor (APS) with FD SOI Tunnel FET
N. Dagtekin and A. M. Ionescu, EPFL, Switzerland

This paper presents the first energy efficient highly compact concept of active pixel sensor built with a single partially-gated tunnel FET (TFET). Experimental results show that the transistor characteristics of the investigated TFETs are nonlinearly modulated by optical excitation and an optical gain is reported for the first time. A memory effect is observed and exploited when the back-gate is used as a secondary gate to control charge storing mechanism in the body, similarly to back gate illuminated photodiode pixels. Compared to CMOS, 1T-TFET pixels offer high sensitivity (detection limit < 2pW/μm2 in visible light), low power operation, improved temperature stability and high compactness (1T architecture with pixel size of ~10x1μm2 in this work).

Yole on Image Sensor Future

Yole Developpement's recent presentation "More than Moore market and technology trends" forecasts the future of image sensor industry:

Stacked BSI = wafers connected by TSV
Hybryd BSI = stacked sensor with Cu-Cu hybrid bonding