Single-chip CMOS image sensors for a retina implant system

Schwarz, Markus; Hauschild, R.; Hosticka, B.J.; Huppertz, J.; Kneip, T.; Kolnsberg, S.; Ewe, Lutz; Trieu, Hoc Khiem

doi:10.1109/82.775382

Cited by 51 publications

(14 citation statements)

References 7 publications

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“…The major reason for the growing interest in CMOS image sensors is customer demand for miniaturized, more integration (more functions on a chip), low power, and cost effective imaging systems [1][2]. The vast majority of the reported image sensors are implemented in voltage-mode [1,[3][4][5][6]. Nowadays, size reduction of CMOS devices which necessitates lower supply voltages to reduce the power dissipation has revived interest in current mode techniques.…”

Section: Introductionmentioning

confidence: 99%

Response Mode Detection of a Linear-Logarithmic Image Sensor Using a Current-Mode Readout Circuit

Khamsehashari

Audet

2013

CSSP

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A current-mode image sensor architecture using a linear-logarithmic pixel in order to improve the dynamic range is presented. The pixel cell is based on a 3T active pixel structure with a PMOS readout transistor in the linear region of operation and a PMOS reset transistor that allows for a linear-logarithmic response. An intrascene dynamic range of 90dB is obtained with a pixel fill factor of 37%. The readout circuit is composed of a first-generation current conveyor, a current memory employed as a delta reset sampling unit, a differential amplifier used as an integrator and a dynamic comparator. The pixel response operating mode is determined in the column readout. A signal is sent to the digital processing unit as an indicator to determine the pixel response operating mode in order to allow the proper analog to digital conversion. The image lag effect observed in the pixel output current is removed by the delta reset sampling circuit. Experimental results, obtained from a test structure, are presented. The circuit was fabricated in a CMOS 0.35um process from Austria Microsystems.

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Section: Introductionmentioning

confidence: 99%

Response Mode Detection of a Linear-Logarithmic Image Sensor Using a Current-Mode Readout Circuit

Khamsehashari

Audet

2013

CSSP

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“…There is a growing interest in monitoring object related information like temperature, acceleration or pressure [1], [2]. Other applications aim to enhance the label functionality by optical devices like image sensors [3] and displays [4]. Compared to pure identification applications, the energy demand of these so called smart label applications is higher.…”

Section: Introductionmentioning

confidence: 99%

Efficient Antenna Design of Inductive Coupled RFID-Systems with High Power Demand

Reinhold¹,

Scholz²,

John³

et al. 2007

JCM

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In contrast to pure identification labels, passive inductive coupled RFID transponders with enhanced functionality have an increased power consumption. A nonoptimized antenna design for high power transponders may lead to a poor efficiency and high magnetic field emissions. Therefore, in this work, the energy transmission of inductive coupled systems is investigated, enabling an optimized system design. The RFID system is modeled by network elements in order to optimize the energy transmission. Next to a brief review of different methods for the antenna parameter determination, a new modification of the PEEC method is derived enabling an accelerated and accurate computation of the mutual coupling of the reader and the transponder antenna. Along with the simplification of the transformed transponder impedance and the investigation of the reader matching, consecutive design steps are deduced. The influence of the location-dependent antenna coupling on the energy transmission is characterized. Two case studies are carried out showing a successful transmission of 80mW over a distance of up to 7.6 cm by 275mW reader output power. This system demonstrates an efficient energy supply of a high power transponder while keeping the field emissions low.

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“…Apparently, the region of more detail in human the biological retina must to the great density of cones [ 6,7]. If an artificial retina follows the same model, first present will have two types of photoreceptors cells; second, to have the same size of these cells and third to know a distribution space the photoreceptors.…”

Section: Introductionmentioning

confidence: 99%

Foveal model of artificial retina with phototransistors in Darlington configuration in the high-resolution region

Loaiza-Brito

Calzada

Niño-de-Rivera

2005

2005 2nd International Conference on Electrical and Electronics Engineering

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In this article is proposing a structure of foveal artificial retina to use bipolar phototransistors in configuration Darlington within the central zone and bipolar phototransistors in the periphery. These last ones are forming groups of four elements with a size that is growing towards the periphery, this causes an increase of the area of incidence without modifying to a great extent the size of the phototransistors and thus to take advantage of better the area silicon, in addition it occurs to know a new structure in where the analysis of the foveal model with rectangular phototransistors is possible. This a structure new is not necessary that the photodetectors have a specific and complex design, as can be the circular form that has been used in diverse models. An analysis is made on the voltage of operation the two configurations of phototransistors with the objective to present the idea raised in relation cones and canes a biological retina. With the previous, is a simulation in which an image with the proposed model can be observed. The results in Matlab appear with which the degree of resolution in the center of the foveal model is observed.

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Single-chip CMOS image sensors for a retina implant system

Cited by 51 publications

References 7 publications

Response Mode Detection of a Linear-Logarithmic Image Sensor Using a Current-Mode Readout Circuit

Response Mode Detection of a Linear-Logarithmic Image Sensor Using a Current-Mode Readout Circuit

Efficient Antenna Design of Inductive Coupled RFID-Systems with High Power Demand

Foveal model of artificial retina with phototransistors in Darlington configuration in the high-resolution region

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