3,956 research outputs found

    Advances on CMOS image sensors

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    This paper offers an introduction to the technological advances of image sensors designed using complementary metal–oxide–semiconductor (CMOS) processes along the last decades. We review some of those technological advances and examine potential disruptive growth directions for CMOS image sensors and proposed ways to achieve them. Those advances include breakthroughs on image quality such as resolution, capture speed, light sensitivity and color detection and advances on the computational imaging. The current trend is to push the innovation efforts even further as the market requires higher resolution, higher speed, lower power consumption and, mainly, lower cost sensors. Although CMOS image sensors are currently used in several different applications from consumer to defense to medical diagnosis, product differentiation is becoming both a requirement and a difficult goal for any image sensor manufacturer. The unique properties of CMOS process allows the integration of several signal processing techniques and are driving the impressive advancement of the computational imaging. With this paper, we offer a very comprehensive review of methods, techniques, designs and fabrication of CMOS image sensors that have impacted or might will impact the images sensor applications and markets

    CMOS Image Sensor with a Built-in Lane Detector

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    This work develops a new current-mode mixed signal Complementary Metal-Oxide-Semiconductor (CMOS) imager, which can capture images and simultaneously produce vehicle lane maps. The adopted lane detection algorithm, which was modified to be compatible with hardware requirements, can achieve a high recognition rate of up to approximately 96% under various weather conditions. Instead of a Personal Computer (PC) based system or embedded platform system equipped with expensive high performance chip of Reduced Instruction Set Computer (RISC) or Digital Signal Processor (DSP), the proposed imager, without extra Analog to Digital Converter (ADC) circuits to transform signals, is a compact, lower cost key-component chip. It is also an innovative component device that can be integrated into intelligent automotive lane departure systems. The chip size is 2,191.4 × 2,389.8 ÎŒm, and the package uses 40 pin Dual-In-Package (DIP). The pixel cell size is 18.45 × 21.8 ÎŒm and the core size of photodiode is 12.45 × 9.6 ÎŒm; the resulting fill factor is 29.7%

    Polarization Imaging Sensors in Advanced Feature CMOS Technologies

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    The scaling of CMOS technology, as predicted by Moore\u27s law, has allowed for realization of high resolution imaging sensors and for the emergence of multi-mega-pixel imagers. Designing imaging sensors in advanced feature technologies poses many challenges especially since transistor models do not accurately portray their performance in these technologies. Furthermore, transistors fabricated in advanced feature technologies operate in a non-conventional mode known as velocity saturation. Traditionally, analog designers have been discouraged from designing circuits in this mode of operation due to the low gain properties in single transistor amplifiers. Nevertheless, velocity saturation will become even more prominent mode of operation as transistors continue to shrink and warrants careful design of circuits that can exploit this mode of operation. In this research endeavor, I have utilized velocity saturation mode of operation in order to realize low noise imaging sensors. These imaging sensors incorporate low noise analog circuits at the focal plane in order to improve the signal to noise ratio and are fabricated in 0.18 micron technology. Furthermore, I have explored nanofabrication techniques for realizing metallic nanowires acting as polarization filters. These nanoscopic metallic wires are deposited on the surface of the CMOS imaging sensor in order to add polarization sensitivity to the CMOS imaging sensor. This hybrid sensor will serve as a test bed for exploring the next generation of low noise and highly sensitive polarization imaging sensors

    Configurable 3D-integrated focal-plane sensor-processor array architecture

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    A mixed-signal Cellular Visual Microprocessor architecture with digital processors is described. An ASIC implementation is also demonstrated. The architecture is composed of a regular sensor readout circuit array, prepared for 3D face-to-face type integration, and one or several cascaded array of mainly identical (SIMD) processing elements. The individual array elements derived from the same general HDL description and could be of different in size, aspect ratio, and computing resources

    A 10 000 fps CMOS Sensor With Massively Parallel Image Processing

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    International audienceA high-speed analog VLSI image acquisition and preprocessing system has been designed and fabricated in a 0.35 standard CMOS process. The chip features a massively parallel architecture enabling the computation of programmable low-level image processing in each pixel. Extraction of spatial gradients and convolutions such as Sobel or Laplacian filters are implemented on the circuit. Measured results show that the proposed sensor successfully captures raw images up to 10 000 frames per second and runs low-level image processing at a frame rate of 2000 to 5000 frames per second

    Polarization Sensor Design for Biomedical Applications

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    Advances in fabrication technology have enabled the development of compact, rigid polarization image sensors by integrating pixelated polarization filters with standard image sensing arrays. These compact sensors have the capability for allowing new applications across a variety of disciplines, however their design and use may be influenced by many factors. The underlying image sensor, the pixelated polarization filters, and the incident lighting conditions all directly impact how the sensor performs. In this research endeavor, I illustrate how a complete understanding of these factors can lead to both new technologies and applications in polarization sensing. To investigate the performance of the underlying image sensor, I present a new CMOS image sensor architecture with a pixel capable of operation using either measured voltages or currents. I show a detailed noise analysis of both modes, and that, as designed, voltage mode operates with lower noise than current mode. Further, I integrated aluminum nanowires with this sensor post fabrication, realizing the design of a compact CMOS sensor with polarization sensitivity. I describe a full set of experiments designed as a benchmark to evaluate the performance of compact, integrated polarization sensors. I use these tests to evaluate for incident intensity, wavelength, focus, and polarization state, demonstrating the accuracy and limitations of polarization measurements with such a compact sensor. Using these as guides, I present two novel biomedical applications that rely on the compact, real-time nature of compact integrated polarimeters. I first demonstrate how these sensors can be used to measure the dynamics of soft tissue in real-time, with no moving parts or complex optical alignment. I used a 2 megapixel integrated polarization sensor to measure the direction and strength of alignment in a bovine flexor tendon at over 20 frames per second, with results that match the current method of rotating polarizers. Secondly, I present a new technique for optical neural recording that uses intrinsic polarization reflectance and requires no fluorescent dyes or electrodes. Exposing the antennal lobe of the locust Schistocerca americana, I was able to measure a change in the polarization reflectance during the introduction of the odors hexanol and octanol with the integrated CMOS polarization sensor

    CMOS IMAGE SENSORS FOR LAB-ON-A-CHIP MICROSYSTEM DESIGN

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    The work described herein serves as a foundation for the development of CMOS imaging in lab-on-a-chip microsystems. Lab-on-a-chip (LOC) systems attempt to emulate the functionality of a cell biology lab by incorporating multiple sensing modalidites into a single microscale system. LOC are applicable to drug development, implantable sensors, cell-based bio-chemical detectors and radiation detectors. The common theme across these systems is achieving performance under severe resource constraints including noise, bandwidth, power and size. The contributions of this work are in the areas of two core lab-on-a-chip imaging functions: object detection and optical measurements

    High-speed global shutter CMOS machine vision sensor with high dynamic range image acquisition and embedded intelligence

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    High-speed imagers are required for industrial applications, traffic monitoring, robotics and unmanned vehicles, moviemaking, etc. Many of these applications call also for large spatial resolution, high sensitivity and the ability to detect images with large intra-frame dynamic range. This paper reports a CIS intelligent digital image sensor with 5.2Mpixels which delivers 12-bit fully-corrected images at 250Fps. The new sensor embeds on-chip digital processing circuitry for a large variety of functions including: windowing; pixel binning; sub-sampling; combined windowing-binning-subsampling modes; fixed-pattern noise correction; fine gain and offset control; color processing, etc. These and other CIS functions are programmable through a simple four-wire serial port interface.Ministerio de Ciencia e InnovaciĂłn IPT-2011-1625-43000
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