CMOS image sensors: electronic camera-on-a-chip
TL;DR: In this article, the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
Abstract: CMOS active pixel sensors (APS) have performance competitive with charge-coupled device (CCD) technology, and offer advantages in on-chip functionality, system power reduction, cost, and miniaturization. This paper discusses the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
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TL;DR: Progress in light sensing using nanostructured materials is reviewed, focusing on solution-processed materials such as colloidal quantum dots and metal nanoparticles.
Abstract: The detection of photons underpins imaging, spectroscopy, fibre-optic communications and time-gated distance measurements. Nanostructured materials are attractive for detection applications because they can be integrated with conventional silicon electronics and flexible, large-area substrates, and can be processed from the solution phase using established techniques such as spin casting, spray coating and layer-by-layer deposition. In addition, their performance has improved rapidly in recent years. Here we review progress in light sensing using nanostructured materials, focusing on solution-processed materials such as colloidal quantum dots and metal nanoparticles. These devices exhibit phenomena such as absorption of ultraviolet light, plasmonic enhancement of absorption, size-based spectral tuning, multiexciton generation, and charge carrier storage in surface and interface traps.
1,253 citations
TL;DR: The state of the art in machine vision inspection and a critical overview of real-world applications are presented and two independent ways to classify applications are proposed.
716 citations
TL;DR: This paper provides a comprehensive overview of the emerging field of event-based vision, with a focus on the applications and the algorithms developed to unlock the outstanding properties of event cameras.
Abstract: Event cameras are bio-inspired sensors that differ from conventional frame cameras: Instead of capturing images at a fixed rate, they asynchronously measure per-pixel brightness changes, and output a stream of events that encode the time, location and sign of the brightness changes. Event cameras offer attractive properties compared to traditional cameras: high temporal resolution (in the order of is), very high dynamic range (140dB vs. 60dB), low power consumption, and high pixel bandwidth (on the order of kHz) resulting in reduced motion blur. Hence, event cameras have a large potential for robotics and computer vision in challenging scenarios for traditional cameras, such as low-latency, high speed, and high dynamic range. However, novel methods are required to process the unconventional output of these sensors in order to unlock their potential. This paper provides a comprehensive overview of the emerging field of event-based vision, with a focus on the applications and the algorithms developed to unlock the outstanding properties of event cameras. We present event cameras from their working principle, the actual sensors that are available and the tasks that they have been used for, from low-level vision (feature detection and tracking, optic flow, etc.) to high-level vision (reconstruction, segmentation, recognition). We also discuss the techniques developed to process events, including learning-based techniques, as well as specialized processors for these novel sensors, such as spiking neural networks. Additionally, we highlight the challenges that remain to be tackled and the opportunities that lie ahead in the search for a more efficient, bio-inspired way for machines to perceive and interact with the world.
697 citations
Cites methods from "CMOS image sensors: electronic came..."
...1 combines a conventional active pixel sensor (APS) [52] in the same pixel with DVS....
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Journal Article•
TL;DR: In this article, the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
Abstract: CMOS active pixel sensors (APS) have performance competitive with charge-coupled device (CCD) technology, and offer advantages in on-chip functionality, system power reduction, cost, and miniaturization. This paper discusses the requirements for CMOS image sensors and their historical development, CMOS devices and circuits for pixels, analog signal chain, and on-chip analog-to-digital conversion are reviewed and discussed.
693 citations
TL;DR: A way of integrating photonics with silicon nanoelectronics is described, using polycrystalline silicon on glass islands alongside transistors on bulk silicon complementary metal–oxide–semiconductor chips to address the demand for high-bandwidth optical interconnects in data centres and high-performance computing.
Abstract: Electronic and photonic technologies have transformed our lives-from computing and mobile devices, to information technology and the internet. Our future demands in these fields require innovation in each technology separately, but also depend on our ability to harness their complementary physics through integrated solutions1,2. This goal is hindered by the fact that most silicon nanotechnologies-which enable our processors, computer memory, communications chips and image sensors-rely on bulk silicon substrates, a cost-effective solution with an abundant supply chain, but with substantial limitations for the integration of photonic functions. Here we introduce photonics into bulk silicon complementary metal-oxide-semiconductor (CMOS) chips using a layer of polycrystalline silicon deposited on silicon oxide (glass) islands fabricated alongside transistors. We use this single deposited layer to realize optical waveguides and resonators, high-speed optical modulators and sensitive avalanche photodetectors. We integrated this photonic platform with a 65-nanometre-transistor bulk CMOS process technology inside a 300-millimetre-diameter-wafer microelectronics foundry. We then implemented integrated high-speed optical transceivers in this platform that operate at ten gigabits per second, composed of millions of transistors, and arrayed on a single optical bus for wavelength division multiplexing, to address the demand for high-bandwidth optical interconnects in data centres and high-performance computing3,4. By decoupling the formation of photonic devices from that of transistors, this integration approach can achieve many of the goals of multi-chip solutions 5 , but with the performance, complexity and scalability of 'systems on a chip'1,6-8. As transistors smaller than ten nanometres across become commercially available 9 , and as new nanotechnologies emerge10,11, this approach could provide a way to integrate photonics with state-of-the-art nanoelectronics.
630 citations
References
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08 Feb 1996
TL;DR: In this article, a 128/spl times/128-pixel image sensor with a 20 s-10/sup -4/ s electronic shutter has been integrated in a 1.2-/spl mu/m digital CMOS technology.
Abstract: A 128/spl times/128-pixel image sensor with a 20 s-10/sup -4/ s electronic shutter has been integrated in a 1.2-/spl mu/m digital CMOS technology. The pixel cell consists of four PMOS transistors and a photodiode with antiblooming suppression. Each pixel measures 24 /spl mu/m by 24 /spl mu/m and has a fill factor of 25%. Current is used to transfer pixel signals to the column readout amplifiers in order to minimize voltage swings on the highly capacitive column lines. Correlated double sampling is used to reduce intracolumn fixed pattern noise. The saturation voltage is 470 mV. The peak output signal to noise ratio is 45 dB, and the optical dynamic range is 56 dB. The frame transfer rate is 1.7 ms per frame.
96 citations
Journal Article•
TL;DR: A chip implementing random scan was designed, fabricated, and tested and was found to operate functionally, however, the use of a standard process gave rise to the crosstalk phenomenon, which has yet to be overcome.
94 citations
"CMOS image sensors: electronic came..." refers methods in this paper
...More complication was added by the Technion to permit random access and electronic shuttering with a significant increase in pixel size [ 47 ]....
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15 Feb 1995
TL;DR: This 256/spl times/256 active pixel sensor (APS) is designed for consumer multimedia applications requiring low-cost, high-functionality, compact cameras capable of acquiring high-quality images at video frame rates.
Abstract: This 256/spl times/256 active pixel sensor (APS) is designed for consumer multimedia applications requiring low-cost, high-functionality, compact cameras capable of acquiring high-quality images at video frame rates. This sensor allows random access of the image data, permitting a simple implementation of electronic pan and zoom. Use in portable equipment is simplified by standard operating voltages and low power (80mW@5V, 20mW@3.3V). Fabrication in a standard CMOS process allows the integration of a variety of new and existing digital circuits with the image sensor. In addition, by making use of the implicit dynamic frame buffer provided by the active pixel structure, the sensor can generate a signal that represents the difference between sequential frames. This may be used for motion detection, image stabilization, and compression purposes.
92 citations
TL;DR: In this paper, a 64/spl times/64-pixel image sensor with full-frame analog memory and an on-chip motion processor is presented, which uses the switched-capacitor technique and calculates the difference between the values of the signal on each pixel in successive frames.
Abstract: A 64/spl times/64-pixel image sensor with full-frame analog memory and on-chip motion processor is presented. The processor consists of a charge amplifier and an analog subtractor. It uses the switched-capacitor technique and calculates the difference between the values of the signal on each pixel in successive frames. The rate can achieve up to 60 frames/s with limited area and power overhead. The analog memory required for the storage of the previous frame is implemented using implanted capacitors placed within the sensor array. Fabricated in a 1.2-/spl mu/m standard CMOS process with an added metal 3 light-shielding layer, the circuit is fully functional and requires a total core area of 13 mm/sup 2/. >
76 citations
"CMOS image sensors: electronic came..." refers methods in this paper
...Other examples of signal processing demonstrated in CMOS image sensors include smoothing using neuronMOSFET’s [71], motion detection [72], [ 73 ], programmable amplification [74], multiresolution imaging [75], video compression [76], dynamic range en-...
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Book Chapter•
01 Jan 1985
TL;DR: In this paper, the elements of an electronic receptor with many orders of magnitude dynamic range are described, and the key to very sensitive receptors is to use the current gain of this very clean bipolar transistor before subjecting the signal to any noise from subsequent amplification stages.
Abstract: The photoreceptors in biological systems give meaningful outputs over about six orders of magnitude of illumination intensity. If we are to build an electronic vision system that is truly useful, it must have a similar dynamic range. The elements of an electronic receptor with many orders of magnitude dynamic range are described below. Experimental
devices were fabricated in p-well cMOS bulk technology through the MOSIS foundry; npn phototransistors with collector connected to substrate are a byproduct of this process. The n-type bulk forms the collector, the p-well is the base, and the n+ diffusion the emitter. In a
typical process, a large transistor of this sort has a current gain β of more than a thousand. Smaller transistors have lower current gains, but are still respectable. The key to very sensitive receptors is to use the current
gain of this very clean bipolar transistor before subjecting the signal to any noise from subsequent amplification stages.
75 citations