Two Dimensional Amorphous Silicon Image Sensor Arrays

1995 ◽  
Vol 377 ◽  
Author(s):  
R. A. Street ◽  
X. D. Wu ◽  
R. Weisfield ◽  
S. Ready ◽  
R. Apte ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
High Speed ◽  
Sensor Array ◽  
Imaging System ◽  
Sensor Arrays ◽  
Image Sensor ◽  
Two Dimensional ◽  
Pixel Resolution ◽  
Array Architecture ◽  
The Matrix

ABSTRACTLarge two dimensional amorphous silicon image sensor arrays offer a new approach to electronic document input and x-ray imaging. The sensor array technology is now capable of image capture at greater than 10 frames/sec and with resolution of 200–400 spi. We describe our new high resolution imaging system, comprising a page-sized sensor array with nearly 3 million pixels, and the accompanying high speed read out and processing electronics. The key technological issues of pixel resolution, sensor fill factor, leakage currents and noise are reviewed. Measurements of a new array architecture are described, in which the sensor is formed as a single continuous film on top of the matrix addressing components.

Color Document Imaging with Amorphous Silicon Sensor Arrays

1994 ◽  
Vol 336 ◽  
Author(s):  
R. A. Street ◽  
X. D. Wu ◽  
R. Weisfield ◽  
S. Nelson ◽  
P. Nylen
Keyword(s):  
Amorphous Silicon ◽  
High Speed ◽  
Imaging System ◽  
Sensor Arrays ◽  
Color Imaging ◽  
Silicon Sensors ◽  
Imaging Properties ◽  
Color Filters ◽  
Illumination Source ◽  
Silicon Sensor

ABSTRACTWe describe the performance of an amorphous silicon imaging system designed for high speed (>10 frames/sec) scanning of a document. The system comprises a new page-sized sensor array with 1536×1920 pixels, an illumination source, and the readout electronics. With appropriate color filters, one can achieve color imaging of a document without the registration problems associated with linear scanners. We describe the color imaging properties and discuss how the color response, sensitivity and uniformity depend on the properties of the amorphous silicon sensors.

Two-dimensional amorphous silicon image sensor arrays

1996 ◽  
Vol 198-200 ◽  
pp. 1151-1154 ◽  
Author(s):  
R.A. Street ◽  
X.D. Wu ◽  
R. Weisfield ◽  
S. Ready ◽  
R. Apte ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Sensor Arrays ◽  
Image Sensor ◽  
Two Dimensional

Amorphous Silicon Image Sensor Arrays

1992 ◽  
Vol 258 ◽  
Author(s):  
M J Powell ◽  
I D French ◽  
J R Hughes ◽  
N C Bird ◽  
O S Davies ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
High Speed ◽  
Dynamic Range ◽  
Sensor Arrays ◽  
Image Sensor ◽  
Low Noise ◽  
Image Sensors ◽  
Frame Rate ◽  
Intimate Contact ◽  
Current Densities

ABSTRACTWe have developed a technology for 2D matrix-addressed image sensors using amorphous silicon photodiodes and thin film transistors. We have built a small prototype, having 192×192 pixels with a 20μm pixel pitch, and assessed its performance. The nip photodiodes can have dark current densities of less than 1011 A.cm-2 (up to 5V reverse bias) and peak quantum efficiencies of 88% (at 580nm). We operated the sensor in real time mode at high speed (50 Hz frame rate and 64μS line time). The image sensor has a low noise performance giving a dynamic range in excess of 104. The maximum crosstalk is about 2%, which allows at least 50 grey levels. The bottom contact of the photodiode acts as a light shield from light through the substrate, which enables the sensor to be operated as an intimate contact image sensor to image a document placed directly on top of the array. In this mode, the CTF was 75% at 2 lp.mm1. Good quality images are demonstrated in both front projection and intimate contact imaging modes.

scholarly journals Curating Metal-Organic Frameworks to Compose Robust Gas Sensor Arrays in Dilute Conditions

2019 ◽  
Author(s):  
Arni Sturluson ◽  
Rachel Sousa ◽  
Yujing Zhang ◽  
Melanie T. Huynh ◽  
Caleb Laird ◽  
...  
Keyword(s):  
Sensor Array ◽  
Gas Sensing ◽  
Metal Organic Frameworks ◽  
Sensor Arrays ◽  
Gas Composition ◽  
Composition Space ◽  
The Matrix ◽  
Metal Organic ◽  
Analyte Detection ◽  
Value Decomposition

Metal-organic frameworks (MOFs)-- tunable, nano-porous materials-- are alluring recognition elements for gas sensing. Mimicking human olfaction, an array of cross-sensitive, MOF-based sensors could enable analyte detection in complex, variable gas mixtures containing confounding gas species. Herein, we address the question: given a set of MOF candidates and their adsorption properties, how do we select the optimal subset to compose a sensor array that accurately and robustly predicts the gas composition via monitoring the adsorbed mass in each MOF? We first mathematically formulate the MOF-based sensor array problem under dilute conditions. Instructively, the sensor array can be viewed as a linear map from <i>gas composition space</i> to <i>sensor array response space</i> defined by the matrix <b>H</b> of Henry coefficients of the gases in the MOFs. Characterizing this mapping, the singular value decomposition of <b>H </b>is a useful tool for evaluating MOF subsets for sensor arrays, as it determines the sensitivity of the predicted gas composition to measurement error, quantifies the magnitude of the response to changes in composition, and recovers which direction in gas composition space elicits the largest/smallest response. To illustrate, on the basis of experimental adsorption data, we curate MOFs for a sensor array with the objective of determining the concentration of CO<sub>2</sub> and SO<sub>2</sub> in the gas phase.

scholarly journals Development of a Compact,  Configurable, Real-Time Range  Imaging System

2021 ◽  
Author(s):  
◽  
Adrian Peter Paul Jongenelen
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Modulation Frequency ◽  
Image Sensor ◽  
Measurement Precision ◽  
Operating Parameters ◽  
Range Imaging ◽  
Field Range ◽  
Full Field ◽  
Precision And Accuracy

<p>This thesis documents the development of a time-of-flight (ToF) camera suitable for autonomous mobile robotics applications. By measuring the round trip time of emitted light to and from objects in the scene, the system is capable of simultaneous full-field range imaging. This is achieved by projecting amplitude modulated continuous wave (AMCW) light onto the scene, and recording the reflection using an image sensor array with a high-speed shutter amplitude modulated at the same frequency (of the order of tens of MHz). The effect is to encode the phase delay of the reflected light as a change in pixel intensity, which is then interpreted as distance. A full field range imaging system has been constructed based on the PMD Technologies PMD19k image sensor, where the high-speed shuttering mechanism is builtin to the integrated circuit. This produces a system that is considerably more compact and power efficient than previous iterations that employed an image intensifier to provide sensor modulation. The new system has comparable performance to commercially available systems in terms of distance measurement precision and accuracy, but is much more flexible with regards to its operating parameters. All of the operating parameters, including the image integration time, sensor modulation phase offset and modulation frequency can be changed in realtime either manually or automatically through software. This highly configurable system serves as an excellent platform for research into novel range imaging techniques. One promising technique is the utilisation of measurements using multiple modulation frequencies in order to maximise precision over an extended operating range. Each measurement gives an independent estimate of the distance with limited range depending on the modulation frequency. These are combined to give a measurement with extended maximum range using a novel algorithm based on the New Chinese Remainder Theorem. A theoretical model for the measurement precision and accuracy of the new algorithm is presented and verified with experimental results. All distance image processing is performed on a per-pixel basis in real-time using a Field Programmable Gate Array (FPGA). An efficient hardware implementation of the phase determination algorithm for calculating distance is investigated. The limiting resource for such an implementation is random access memory (RAM), and a detailed analysis of the trade-off between this resource and measurement precision is also presented.</p>

A Linearized Two-Dimensional Theory for High-Speed Hydrofoils Near the Free Surface

1966 ◽  
Vol 10 (01) ◽  
pp. 25-48
Author(s):  
Richard P. Bernicker
Keyword(s):  
Direct Problem ◽  
High Speed ◽  
Two Dimensional ◽  
Algebraic Equations ◽  
Pressure Loading ◽  
Dimensional Theory ◽  
Linear Algebraic Equations ◽  
The Matrix ◽  
Sectional Shape ◽  
Infinite Set

A linearized two-dimensional theory is presented for high-speed hydrofoils near the free surface. The "direct" problem (hydrofoil shape specified) is attacked by replacing the actual foil with vortex and source sheets. The resulting integral equation for the strength of the singularity distribution is recast into an infinite set of linear algebraic equations relating the unknown constants in a Glauert-type vorticity expansion to the boundary condition on the foil. The solution is achieved using a matrix inversion technique and it is found that the matrix relating the known and unknown constants is a function of depth of submergence alone. Inversion of this matrix at each depth allows the vorticity constants to be calculated for any arbitrary foil section by matrix multiplication. The inverted matrices have been calculated for several depth-to-chord ratios and are presented herein. Several examples for specific camber and thickness distributions are given, and results indicate significant effects in the force characteristics at depths less than one chord. In particular, thickness effects cause a loss of lift at shallow submergences which may be an appreciable percentage of the total design lift. The second part treats the "indirect" problem of designing a hydrofoil sectional shape at a given depth to achieve a specified pressure loading. Similar to the "direct" problem treated in the first part, integral equations are derived for the camber and thickness functions by replacing the actual foil by vortex and source sheets. The solution is obtained by recasting these equations into an infinite set of linear algebraic equations relating the constants in a series expansion of the foil geometry to the known pressure boundary conditions. The matrix relating the known and unknown constants is, again, a function of the depth of submergence alone, and inversion techniques allow the sectional shape to be determined for arbitrary design pressure distributions. Several examples indicate the procedure and results are presented for the change in sectional shape for a given pressure loading as the depth of submergence of the foil is decreased.

The Design of High-Speed CMOS Imaging System Based on SOPC Technology

2010 ◽  
Vol 39 ◽  
pp. 523-528
Author(s):  
Xin Hua Yang ◽  
Yuan Yuan Shang ◽  
Da Wei Xu ◽  
Hui Zhuo Niu
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Image Acquisition ◽  
Image Data ◽  
Image Sensor ◽  
Acquisition System ◽  
Storage Unit ◽  
Data Encoding ◽  
Acquisition Speed ◽  
Image Acquisition System

This paper introduces a design of a high-speed image acquisition system based on Avalon bus which is supported with SOPC technology. Some peripherals embedded in Avalon bus were customized and utilized in this system, such as imaging unit, decoding unit and storage unit, and these improved the speed of the whole imaging system. The data is compressed to three-fourths of the original by the decoding unit. A custom DMA is designed for moving the image data to the two caches of the SDRAM. This approach discards the method that FIFO must be put up in the traditional data acquisition system. And therefore, it reduced the CPU’s task for data moving. At the same time, the image acquisition and the data transmission can complete a parallel job. Finally, the design is worked on the high-speed image acquisition system which is made up of 2K*2K CMOS image sensor. And it improved the image acquisition speed by three ways: data encoding, custom DMA controller and the parallel processing.

scholarly journals Chemistry integrated circuit: chemical system on a complementary metal oxide semiconductor integrated circuit

2014 ◽  
Vol 372 (2012) ◽  
pp. 20130109 ◽  
Author(s):  
Kazuo Nakazato
Keyword(s):  
Integrated Circuit ◽  
High Speed ◽  
Large Scale ◽  
Sensor Array ◽  
Single Photon ◽  
Sensor Arrays ◽  
Oxide Semiconductor ◽  
Chemical System ◽  
Photoelectric Conversion ◽  
Integrated Sensor

By integrating chemical reactions on a large-scale integration (LSI) chip, new types of device can be created. For biomedical applications, monolithically integrated sensor arrays for potentiometric, amperometric and impedimetric sensing of biomolecules have been developed. The potentiometric sensor array detects pH and redox reaction as a statistical distribution of fluctuations in time and space. For the amperometric sensor array, a microelectrode structure for measuring multiple currents at high speed has been proposed. The impedimetric sensor array is designed to measure impedance up to 10 MHz. The multimodal sensor array will enable synthetic analysis and make it possible to standardize biosensor chips. Another approach is to create new functional devices by integrating molecular systems with LSI chips, for example image sensors that incorporate biological materials with a sensor array. The quantum yield of the photoelectric conversion of photosynthesis is 100%, which is extremely difficult to achieve by artificial means. In a recently developed process, a molecular wire is plugged directly into a biological photosynthetic system to efficiently conduct electrons to a gold electrode. A single photon can be detected at room temperature using such a system combined with a molecular single-electron transistor.

scholarly journals Development of a Compact,  Configurable, Real-Time Range  Imaging System

2021 ◽  
Author(s):  
◽  
Adrian Peter Paul Jongenelen
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Modulation Frequency ◽  
Image Sensor ◽  
Measurement Precision ◽  
Operating Parameters ◽  
Range Imaging ◽  
Field Range ◽  
Full Field ◽  
Precision And Accuracy

<p>This thesis documents the development of a time-of-flight (ToF) camera suitable for autonomous mobile robotics applications. By measuring the round trip time of emitted light to and from objects in the scene, the system is capable of simultaneous full-field range imaging. This is achieved by projecting amplitude modulated continuous wave (AMCW) light onto the scene, and recording the reflection using an image sensor array with a high-speed shutter amplitude modulated at the same frequency (of the order of tens of MHz). The effect is to encode the phase delay of the reflected light as a change in pixel intensity, which is then interpreted as distance. A full field range imaging system has been constructed based on the PMD Technologies PMD19k image sensor, where the high-speed shuttering mechanism is builtin to the integrated circuit. This produces a system that is considerably more compact and power efficient than previous iterations that employed an image intensifier to provide sensor modulation. The new system has comparable performance to commercially available systems in terms of distance measurement precision and accuracy, but is much more flexible with regards to its operating parameters. All of the operating parameters, including the image integration time, sensor modulation phase offset and modulation frequency can be changed in realtime either manually or automatically through software. This highly configurable system serves as an excellent platform for research into novel range imaging techniques. One promising technique is the utilisation of measurements using multiple modulation frequencies in order to maximise precision over an extended operating range. Each measurement gives an independent estimate of the distance with limited range depending on the modulation frequency. These are combined to give a measurement with extended maximum range using a novel algorithm based on the New Chinese Remainder Theorem. A theoretical model for the measurement precision and accuracy of the new algorithm is presented and verified with experimental results. All distance image processing is performed on a per-pixel basis in real-time using a Field Programmable Gate Array (FPGA). An efficient hardware implementation of the phase determination algorithm for calculating distance is investigated. The limiting resource for such an implementation is random access memory (RAM), and a detailed analysis of the trade-off between this resource and measurement precision is also presented.</p>

scholarly journals A Discrete Dipole Approximation Solver Based on the COCG-FFT Algorithm and Its Application to Microwave Breast Imaging

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Samar Hosseinzadegan ◽  
Andreas Fhager ◽  
Mikael Persson ◽  
Paul Meaney
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Breast Imaging ◽  
Imaging System ◽  
Dipole Moments ◽  
Dipole Approximation ◽  
Discrete Dipole Approximation ◽  
Two Dimensional ◽  
Iterative Solver ◽  
The Matrix

We introduce the discrete dipole approximation (DDA) for efficiently calculating the two-dimensional electric field distribution for our microwave tomographic breast imaging system. For iterative inverse problems such as microwave tomography, the forward field computation is the time limiting step. In this paper, the two-dimensional algorithm is derived and formulated such that the iterative conjugate orthogonal conjugate gradient (COCG) method can be used for efficiently solving the forward problem. We have also optimized the matrix-vector multiplication step by formulating the problem such that the nondiagonal portion of the matrix used to compute the dipole moments is block-Toeplitz. The computation costs for multiplying the block matrices times a vector can be dramatically accelerated by expanding each Toeplitz matrix to a circulant matrix for which the convolution theorem is applied for fast computation utilizing the fast Fourier transform (FFT). The results demonstrate that this formulation is accurate and efficient. In this work, the computation times for the direct solvers, the iterative solver (COCG), and the iterative solver using the fast Fourier transform (COCG-FFT) are compared with the best performance achieved using the iterative solver (COCG-FFT) in C++. Utilizing this formulation provides a computationally efficient building block for developing a low cost and fast breast imaging system to serve under-resourced populations.

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