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Journal ArticleDOI

CMOS image sensors: electronic camera-on-a-chip

01 Oct 1997-IEEE Transactions on Electron Devices (IEEE)-Vol. 44, Iss: 10, pp 1689-1698
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.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the development, physics, and technology of the pinned photodiode is reviewed and a detailed review of its use in CCD and CMOS image sensors is presented.
Abstract: The pinned photodiode is the primary photodetector structure used in most CCD and CMOS image sensors. This paper reviews the development, physics, and technology of the pinned photodiode.

364 citations

Journal ArticleDOI
TL;DR: In this article, an Arbitrated address-event imager was designed and fabricated in a 0.6-/spl mu/m CMOS process, which is composed of 80 /spl times/ 60 pixels of 32 /spltimes/ 30 /spl m/m. Tests conducted on the imager showed a large output dynamic range of 180 dB (under bright local illumination) for an individual pixel.
Abstract: An arbitrated address-event imager has been designed and fabricated in a 0.6-/spl mu/m CMOS process. The imager is composed of 80 /spl times/ 60 pixels of 32 /spl times/ 30 /spl mu/m. The value of the light intensity collected by each photosensitive element is inversely proportional to the pixel's interspike time interval. The readout of each spike is initiated by the individual pixel; therefore, the available output bandwidth is allocated according to pixel output demand. This encoding of light intensities favors brighter pixels, equalizes the number of integrated photons across light intensity, and minimizes power consumption. Tests conducted on the imager showed a large output dynamic range of 180 dB (under bright local illumination) for an individual pixel. The array, on the other hand, produced a dynamic range of 120 dB (under uniform bright illumination and when no lower bound was placed on the update rate per pixel). The dynamic range is 48.9 dB value at 30-pixel updates/s. Power consumption is 3.4 mW in uniform indoor light and a mean event rate of 200 kHz, which updates each pixel 41.6 times per second. The imager is capable of updating each pixel 8.3K times per second (under bright local illumination).

362 citations

Patent
26 Oct 2000
TL;DR: In this paper, a system for monitoring a space external to the system is described, which includes a microprocessor, a memory coupled to the microprocessor and a sensor configured to detect at least one environmental parameter of the space and generate a sensor signal derived from the detected environmental parameter.
Abstract: A system for monitoring a space external to the system is disclosed. The system includes a microprocessor, a memory coupled to the microprocessor, a sensor configured to detect at least one environmental parameter of the space external to the system and configured to generate a sensor signal derived from the at least one detected environmental parameter of the space and at least one port for communicating with a network. The memory includes instructions for processing the sensor signal derived from the at least one environmental parameter of the space external to the system and the memory including a web server application. The at least one port is responsive to the microprocessor. The web server application is configured to provide a webpage associated with the sensor signal via the at least one port.

355 citations

Patent
15 May 2008
TL;DR: In this article, the authors present a system and method that enables a data center operator to determine available power and cooling at specific areas and enclosures in a data centre to assist in locating new equipment in the data center.
Abstract: Systems and methods are provided for determining data center cooling and power requirements and for monitoring performance of cooling and power systems in data centers. At least one aspect provides a system and method that enables a data center operator to determine available power and cooling at specific areas and enclosures in a data center to assist in locating new equipment in the data center.

342 citations

Journal ArticleDOI
TL;DR: The polarization imaging sensor has a signal-to-noise ratio of 45 dB and captures intensity, angle and degree of linear polarization in the visible spectrum at 40 frames per second with 300 mW of power consumption.
Abstract: We report an imaging sensor capable of recording the optical properties of partially polarized light by monolithically integrating aluminum nanowire optical filters with a CCD imaging array. The imaging sensor, composed of 1000 by 1000 imaging elements with 7.4 μm pixel pitch, is covered with an array of pixel-pitch matched nanowire optical filters with four different orientations offset by 45°. The polarization imaging sensor has a signal-to-noise ratio of 45 dB and captures intensity, angle and degree of linear polarization in the visible spectrum at 40 frames per second with 300 mW of power consumption.

338 citations

References
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Journal ArticleDOI
TL;DR: A new semiconductor device concept that consists of storing charge in potential wells created at the surface of a semiconductor and moving the charge over the surface by moving the potential minima is described.
Abstract: In this paper we describe a new semiconductor device concept. Basically, it consists of storing charge in potential wells created at the surface of a semiconductor and moving the charge (representing information) over the surface by moving the potential minima. We discuss schemes for creating, transferring, and detecting the presence or absence of the charge. In particular, we consider minority carrier charge storage at the Si-SiO 2 interface of a MOS capacitor. This charge may be transferred to a closely adjacent capacitor on the same substrate by appropriate manipulation of electrode potentials. Examples of possible applications are as a shift register, as an imaging device, as a display device, and in performing logic.

878 citations

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

Journal ArticleDOI
TL;DR: In this paper, a family of CMOS-based active pixel image sensors (APSs) that are inherently compatible with the integration of on-chip signal processing circuitry is reported.
Abstract: A family of CMOS-based active pixel image sensors (APSs) that are inherently compatible with the integration of on-chip signal processing circuitry is reported. The image sensors were fabricated using commercially available 2-/spl mu/m CMOS processes and both p-well and n-well implementations were explored. The arrays feature random access, 5-V operation and transistor-transistor logic (TTL) compatible control signals. Methods of on-chip suppression of fixed pattern noise to less than 0.1% saturation are demonstrated. The baseline design achieved a pixel size of 40 /spl mu/m/spl times/40 /spl mu/m with 26% fill-factor. Array sizes of 28/spl times/28 elements and 128/spl times/128 elements have been fabricated and characterized. Typical output conversion gain is 3.7 /spl mu/V/e/sup -/ for the p-well devices and 6.5 /spl mu/V/e/sup -/ for the n-well devices. Input referred read noise of 28 e/sup -/ rms corresponding to a dynamic range of 76 dB was achieved. Characterization of various photogate pixel designs and a photodiode design is reported. Photoresponse variations for different pixel designs are discussed.

532 citations


"CMOS image sensors: electronic came..." refers background in this paper

  • ...The photogate APS was introduced by JPL in 1993 [53]‐[ 55 ] for high-performance scientific imaging and lowlight applications....

    [...]

Proceedings ArticleDOI
12 Jul 1993
TL;DR: ActivePixel Sensor (APS) as mentioned in this paper is a detector array technology that has at least one active transistor within the pixel unit cell, which eliminates the need for nearly perfect charge transfer, which makes CCD's radiation'soft' and difficult to use under low light conditions, difficult to integrate with on-chip electronics, difficulty to use at low temperatures, and difficulty to manufacture in non-silicon materials that extend wavelength response.
Abstract: Charge-coupled devices (CCDs) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer--the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response. With the active pixel, the signal is driven from the pixel over metallic wires rather than being physically transported in the semiconductor. This paper makes a case for the development of APS technology. The state of the art is reviewed and the application of APS technology to future space-based scientific sensor systems is addressed.

457 citations

Journal ArticleDOI
TL;DR: In this paper, a 2.0 /spl mu/m double-poly, double-metal foundry CMOS active pixel image sensor is reported, which uses TTL compatible voltages, low noise and large dynamic range, and is useful in machine vision and smart sensor applications.
Abstract: A new CMOS active pixel image sensor is reported. The sensor uses a 2.0 /spl mu/m double-poly, double-metal foundry CMOS process and is realized as a 128/spl times/128 array of 40 /spl mu/m/spl times/40 /spl mu/m pixels. The sensor features TTL compatible voltages, low noise and large dynamic range, and will be useful in machine vision and smart sensor applications. >

302 citations