We propose new operation methods that maintain picture quality for a field emitter array - high-gain avalanche rushing amorphous photoconductor (FEA-HARP) image sensor even when strong light enters the sensor. Experimental results showed that blooming generation was suppressed by removing excess charges from the HARP target during horizontal blanking intervals.
We have been investigating the depth estimation system by the depth-from-focus (DFF) using tilted focal planes imaging. The system using our DFF method has enough accuracy for various applications (in-vehicle collision detection et al.), and needs extremely fewer multiple focus images than the conventional DFF methods. Hence, our method gets rid of the bottleneck of the motion speed of optical mechanics which is very slower than that of image processing parts. Therefore, it is suitable for the high speed depth estimation like real-time processing accomplished by hardware such as a smart image sensor or an FPGA.
One of the most useful items of information in the chemical field is the pH. On the other hand the most important information for mankind involves light. The purpose of this study is fabrication of photo and pH fused image sensors, which can be obtained the two-dimensional optical distribution and pH distribution in real time. If the proposed sensor is realized, it is helpful in the understanding of chemical reaction.
We have developed an experimental color image pickup system for ultrahigh definition TV (Super Hi-Vision) with three 33M-pixel CMOS image sensors. The sensor has 2.5-inch optical format and the capability of 60 frames per second progress scanning. The ultra high definition lens and the high data rate signal processing unit have also been developed for this system. In this paper, the specifications of these key equipments are described as well as results of shooting experiments by this system.
A bio-implant device which is capable of releasing chemical compounds in small volume for synaptic stimulation, "artificial synapse" would be a powerful tool for clinical therapeutics and biological research. Especially, we are developing a CMOS based, intelligent artificial synapse which can analyze biochemical phenomena by potential sensing, pH sensing etc. In this work, we develop an electrochemical CMOS chip for micro fluid transportation and integrate them on a multifunctional CMOS sensor chip.
A silicon retina is an intelligent vision sensor that can execute real-time image pre-processing by using a parallel analog circuit that mimics the structure of the neuronal circuits in the vertebrate retina. In order to enhance robustness against changes of illumination in practical environment, we have designed and fabricated a silicon retina exhibiting a wide dynamic range and a constant response against changes in the intensity of the illumination on the basis of a computational model of lightness constancy. The photosensor in the present chip approximates logarithmic illumination-to-voltage transfer characteristics due to the application of a time-modulated reset voltage technique. Two types of image processings, Laplacian-Gaussian-like spatial filtering and computing the frame difference, are carried out by using resistive networks and sample/hold circuits in the chip. As a result of these processings, the chip exhibits lightness constancy in wide range of illumination. We show that the present chip not only has a wide dynamic range but also exihibits a constant response against the changes in the illumination.