Sony Reinforcing Development of Image Sensors

Sony announces a series of strategic initiatives to be introduced under the new management team. One of the three core businesses that Sony plans to invest in is Digital Imaging:

"Sony is reinforcing its development of image sensors, signal processing technologies, lenses and other key digital imaging technologies in which it excels, and plans to leverage these technologies in both its consumer products (such as compact digital still cameras, digital video cameras and interchangeable lens digital cameras) and broadcast and professional products (such as professional use cameras and security cameras) in order to further strengthen and differentiate Sony' overall product line. The Company also plans to extend the use of these key technologies across a wide range of business applications, from security to medical, to further expand the scope of its digital imaging business. Sony will target total sales of 1.5 trillion yen and double-digit operating income margin from the consumer, professional and image sensor businesses by FY14."

"Sony is also drawing on its comprehensive strengths in audio and visual technologies to aggressively promote the growth of "4K" technology, which delivers more than four times the resolution of Full HD. Incorporation of Sony-developed technologies, such as image sensors, image processing compression LSIs and high-speed optical transmission modules into its professional-use and high-end consumer products will pave the way for Sony to continue to expand and enrich its 4K-compatible product lineup."

Update: Few slides from Sony restructuring presentation:

Sionyx Raises $6,882,639

Sionyx SEC filing announces a new $16M investment round of which $6,882,639 has already been raised. The investor has not been named. The non-integer amount suggests that it might have been converted from some foreign currency.

How to Measure PRNU

Albert Theuwissen published another post in "How to Measure" series. It talks about PRNU.

ON Semi to Develop New Star Tracker Sensor for ESA

Business Wire: ON Semi announces that the European Space Agency (ESA) has awarded it a joint development contract for the next generation star tracker CMOS Sensor HAS3.

Once developed and qualified, the High Accuracy Star Tracker 3 (HAS3) image sensor will expand the STAR family of radiation-tolerant CIS. The existing HAS2 CIS offered today by ON Semiconductor is designed for Attitude and Orbit Control (AOCS) space applications. HAS2 has an array of 1024 x 1024 18um pixels and supports non-destructive readout and multiple windowing. Following its qualification in 2007, HAS2 has become the heart of ESA Star Trackers.

The HAS3 will be a 1280 x 1280 pixel, radiation tolerant CMOS sensor that features low read noise, 11 x 11 µm2 pixels having 14 bit performance. The HAS3 sensor will support multiple windowing, will be made available in a fully hermetic sealed package and has the option for backside illumination. Applications for the HAS3 device will include star trackers, sun sensors and other scientific applications.

In July 2011, Plessey, the silicon supplier producing the HAS2 wafers for ON Semi announced that they would be discontinuing manufacture of this product. ON Semiconductor has secured the product inventory to supply this product to customers to service their predicted full lifetime needs. The company has been working with the ESA to assure HAS2 availability for the years to come. After this period, it is expected that the next generation HAS3.

ADVIS Sigma-Delta Pixel Details Revealed

It appears that the details of much discussed ADVIS sigma-delta sensor have been recently published in few sources. First, April 2012 issue IEEE Sensors Journal has an article:

Low Power, High Dynamic Range CMOS Image Sensor Employing Pixel-Level Oversampling Analog-to-Digital Conversion
Authors: Ignjatovic, Z. (Electr. & Comput. Eng. Dept., Univ. of Rochester, Rochester, NY, USA), Maricic, D. ; Bocko, M.F.

ABSTRACT

"We present a theoretical analysis, design, and experimental characterization of a CMOS image sensor with pixel-level ΣΔ oversampling analog-to-digital conversion (ADC). The design employs five transistors per-pixel to implement a charge-based ΣΔ ADC at each pixel. In the current design a dynamic regenerative latch comparator is divided into an input transistor, which is contained within each pixel, and the remaining comparator structure shared among the pixels of each column. A charge feedback digital-to-analog converter (DAC) is implemented at each pixel with a three-transistor structure. As opposed to more traditional CMOS image sensors, this image sensor architecture is suitable for implementations in advanced low supply voltage CMOS technologies since its dynamic range is not affected by the reduction of the pixel reset voltage. In addition, similar to the readout methods in low power random access memory designs, this pixel readout architecture does not employ any active amplifiers which allows for low static power operation. Experimental characterization of a prototype fabricated in a 0.35 μm silicided CMOS technology is presented. The estimated power consumption of the fully integrated 128 × 128 imager including decimation filters and I/O interface is 60 nW/pixel at 30 frames per second for 8-bits per-pixel. A peak signal-to-noise ratio of 52 dB and intra-scene dynamic range of 74 dB were measured. The dynamic range was extended to 91 dB through control of the in-pixel DAC supply voltage over the range of 0.8 V-3.3 V."

Second, University of Rochester published Danijel Maričić PhD Thesis describing the techology in even more details: "Image Sensors Employing Oversampling Sigma-Delta Analog-to-Digital Conversion with High Dynamic Range and Low Power".

The 5T sigma-delta pixel uses both pmos and nmos transistors and 3T-like process (no PD transfer gate):

"Every frame scan generates one-bit per-pixel and the readout is repeated OSR times. The image is reconstructed by a digital decimation circuit synchronized with the readout. The comparator is designed for a sampling rate of #rows*max(OSR)*fps = 128*256*60 = 1.97MHz in order to achieve 60 full resolution frames per second following decimation."

The sensor parameters table shows the achieved performance level:

Few other sigma-delta sensor implementations are discussed in the Thesis, including the one having 3T pixel and digital integrator in the column readout (called "indirect feedback sensor):

This architecture is claimed to solve quite a lot of issues:

The manufactured prototype parameters look quite nice for 3T pixel with such a huge full well:

ON Semi to Continue Supply and Support of HAS2 Sensor

ON Semiconductor announced "Last Buy Status" for its HAS2 space-certified start tracking sensor:

"In July 2011, the silicon supplier producing the HAS2 wafers for ON Semiconductor announced with short notice that they would be discontinuing manufacture of this product. At that time, ON Semiconductor was required to follow industry Product Change Notification procedures and put its HAS2 image sensor on a ‘Last Time Buy Status’. Where
applicable, special arrangements have been made with existing customers to minimize the impact of this transition. In parallel, I want to assure you that ON Semiconductor has secured ample product inventory to supply this product to customers to service their predicted full lifetime needs with margin."

Cornell University Presents Computational 3D Camera

Cornell University Chronicle: Alyosha Molnar, assistant professor of electrical and computer engineering, and his group are building light field image sensors that give readouts of the incident angle of light as it strikes the sensor. The result could be the next generation of 3-D cameras, as well as the ability to focus photos after they're taken, similar to Lytro. This work appears to be a continuation of one presented at ISSCC 2011 (See: A. Wang, P. Gill, and A. Molnar, " An Angle-Sensitive CMOS Imager for Single-Sensor 3D Photography", also in Jan., 2012 issue of JSSC).

"If I want to find something in 3-D space, if I just measure the amount of light hitting different locations, I know a little bit. I'll get some sort of blurry blob," Molnar said. "But if I know the incident angle of the light, I can triangulate back. So the question is how do you measure that?"

Few slides from Alyosha's group research site explain the principle:

The sensors have resolution of 150K pixels, but the increased resolution is promised. The latest sensors are implemented in 130nm 8M+1P CMOS process.

Aptina Global Shutter Whitepaper

Aptina published global shutter whitepaper explaining the basics of the technology and the important parameters. One of the graphs shows global shutter shrink progress:

. Trend in Rolling and Global Shutter Pixels (Source: K. Fife, A. El Gamal,
H.S. P. Wong, IISW, June 2009 and Aptina Imaging Corp.)

Teledyne DALSA Announces Flexible, Stretchable Image Sensor Technology

Teledyne DALSA announces it's in the design phase of a revolutionary, next generation image sensor to address a multitude of markets and benefit machine vision system designers from the factory floor to large scale OEMs. Expectations are that this latest chip will fully eclipse today’s technology for general machine vision — especially for food and environmental inspection. The chip will be available in 3 resolutions, 1, 4 and 12 Megapixels with two primary pixel sizes – 5 and 25 µm. Starting with the base pixel, the sensor field-of-view can be adjusted to meet most requirements, covering a range of 5 –100µm pixel pitch.

As a result of the properties of the silicone, pixel size can be finely tuned by camera or module design, and based on the theoretical properties of the underlying technology we estimate pixel size could vary from 1 to 10x base. In addition, with the current state of the art we are expecting to demonstrate a 1-4x expansion ratio.

Pixelplus Reports Increase in Revenue, Profits

Korea IT Times: It appears that Pixelplus managed to survive the difficult times and now reports improvement in its revenues and profits. The company announced its 2011 revenue of 44.7 billion won, a 77% increase over 2010 and the highest number in its whole history. The net profits of 10.8 billion won were reported.

In the past Pixelplus struggled with the release of new products, underestimated the Chinese market and was sued on patent infringement by few other companies. "The sensational popularity of the new product in the market paved the road for the company to get back on its feet."

All the troubles have been left in the past. The company won all the seven patent lawsuits. In 2007 Pixelplus developed image sensor with integrated ISP for CCTV market. In 2008 Pixelplus started selling the new imagers in China. The company successfully returned to surplus in 2009. The sales revenue reversed the downward trend, growing from 17.5 billion won in 2009 to 25.3 billion won in 2010, then to 44.7 billion won in 2011, all this after sliding down from 38.9 billion won in 2005 to 26.6 billion won in 2006, 17.3 billion won in 2007, and 16.2 billion won in 2008.

"No one disputed that Pixelplus, a South Korean developer of CMOS image sensors for various consumer electronics applications, was breathing its last. However, the company has defeated all difficulties, and is now preparing to make a new legend."