1. Review on 2009 IISW
2. 3D-real-time CCD Imager Based on Background-level Subtraction Scheme
3. Progress in Development of HARP Imaging Device and Its Application
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Noriko Ide, Nana Akahane, Shigetoshi Sugawa
2010 Volume 64 Issue 3 Pages
335-342
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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We discuss the operation methods for keeping a high S/N ratio at all switching points in multiple exposures and for shorting the total integration time of a wide dynamic range (DR) lateral overflow integration capacitor (LOFIC) CMOS image sensor that combines electric-charge voltage conversions in a pixel and a column capacitor. We have used these methods on a color LOFIC CMOS image sensor. This sensor had a pixel pitch of 5.6-um and the number of effective pixels was 800 (H) x 600 (V). It was made by using 0.18-um 2P3M CMOS technology. Fully linear responses were obtained, as well as a DR of 207 dB. Furthermore, the S/N ratio was 26-dB for the image of 18% gray card at all the switching points between the multiple exposures. The total exposure time was1/13-sec and was obtained by three photoelectric conversion operations at FD and LOFIC capacitors and one photoelectric conversion operation in the column capacitor.
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Hiroaki Fujita, Eric Stevens, Hirofumi Komori, Hung Doan, Jeffery Kyan ...
2010 Volume 64 Issue 3 Pages
343-346
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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A new CMOS image sensor using a hole based detector has been developed. The measurement shows that crosstalk is reduced to one-third and dark current is reduced to a thirtieth that of a standard nMOS device. Red-into-green pixel crosstalk is 7% at 650 nm for a 4.3-μm pixel and dark current as low as 6 pA/cm
2 at 60°C. Charge capacities of 60, 11 and 4kh+ have been measured for 4.3-, 1.75- and 1.4-μm pixels, respectively.
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Toshikazu Ohno, Mamoru Arimoto, Hayato Nakashima, Kaori Misawa, Yugo N ...
2010 Volume 64 Issue 3 Pages
347-352
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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A charge multiplication CMOS image sensor was developed that has a 10μm pixel pitch and CIF format. This sensor has an electric charge multiplication electrode unit just behind the photodiode of each pixel, which repeatedly performs impact ionization against a photoelectrically-converted signal charge for the charge multiplication. A prototype sensor was used to evaluate the multiplication characteristics and it showed that the sensor can provide excellent signal amplification control in accordance with the repeated number of impact ionizations and the voltage applied to the charge multiplication electrode. This evaluation also showed that the spatial noise does not increase in relation to the signal amplification. In addition, the sensor yields a clearer image and a significantly higher
S/N in a 0.4 lx low-light environment, in comparison with non-multiplying using charge multiplication of approx. 60 times in 100μs.
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Naoki Ozawa
2010 Volume 64 Issue 3 Pages
353-357
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
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A low noise driving method for CCD imaging devices is developed. In the method, a reset pulse is controlled according to the signal level of the CCD. By an evaluation employing a CCD of VGA size, it has become apparent that signal charge acquired from more than 100 pixels can be read continuously without reset pulses at a scene of 1/64 luminance and that low frequency noise whichi is conspicuous in a reproduced picture can be reduced remarkably.
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Kazuhiro Shimonomura, Tetsuya Yagi
2010 Volume 64 Issue 3 Pages
358-364
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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We describe an intelligent vision sensor (silicon retina) that can pre-process images in real-time by using a parallel analog circuit that mimics the structure of the neuronal circuits in vertebrate retina. In this study, we have designed and fabricated a wide dynamic range silicon retina on the basis of our previous design. The photosensor of the present chip approximates logarithmic illumination-to-voltage transfer characteristics due to a photodiode capacitance modulation technique being applied. The chip in this study has achieved a dynamic range wide enough to perceive objects in both indoor and outdoor environments. Moreover, combining the logarithmic response of the photosensor with the Laplacian-Gaussian-like spatial filtering by a resistive network makes the response amplitude of the chip independent of the illumination intensity.
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Hokuto Seo, Satoshi Aihara, Masakazu Namba, Toshihisa Watabe, Hiroshi ...
2010 Volume 64 Issue 3 Pages
365-371
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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In order to achieve compact Super Hi-Vision color camera without the color separation optical systems, we have been developing a new type of image sensor with three organic photoconductive films sensitive to red(R), green(G) and blue(B). In this paper, we fabricated a stacked organic image sensor with G and R sensitive organic photoconductive films, each of which had readout circuit of zinc oxide (ZnO) thin film transistor (TFT). We successfully demonstrated an image pickup at TV flame rate. The sensor produced a color image with a resolution corresponding to the pixel number of ZnO TFT.
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Tomonari Sawada, Kana Ito, Shoji Kawahito
2010 Volume 64 Issue 3 Pages
373-380
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
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The range resolution of a time-of-flight (TOF) range image sensor with periodical charge-draining operation is analyzed under the influence of ambient light. The analysis explains the effectiveness of a small duty light pulse and a periodical charge-draining structure to reduce the influence of ambient light. A theoretical model of range resolution taking into consideration factors of the duty ratio, the ambient light component, and the diffusion component is presented. The theoretical model under the influence of ambient light well agrees with the experimental results. The offset-charge-canceling technique using two sub-frames effectively enables accurate range measurements under ambient light.
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Takenori Hara, Hideo Saito, Takeo Kanade
2010 Volume 64 Issue 3 Pages
381-388
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
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View disturbing noise must be removed from images obtained with a camera under adverse weather conditions. In this paper, we present a method for removing glare caused by water droplets, or other foreign objects, adhering to protective glass of an imaging lens. We have designed and implemented an electronically controlled optical shutter array that detects and removes glare. We also present the possibility of applying this technique to remove general glare caused by the imaging lens itself.
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Masaki Igarashi, Masayuki Ikebe, Sousuke Shimoyama, Kenta Yamano, Juni ...
2010 Volume 64 Issue 3 Pages
389-398
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
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We propose a fast 2-D bilateral filtering method without kernel-size dependency. Focusing on weighted local histograms and the central limit theorem combined with applying line buffers of column histograms, enables us to reduce the number of necessary memory accesses and calculations. Numerical experiments demonstrated a reduction in both calculations and kernel-size independency. We used a dual core 2-GHz CPU with our method and were able to achieve one million pixels per 0.5 sec operation without the need for downsampling, Single Instruction/Multiple Data (SIMD) or multi-thread operation.
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Yoshiro Takiguchi, Masakazu Nanba, Yuuki Honda, Misao Kubota, Norifumi ...
2010 Volume 64 Issue 3 Pages
399-404
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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We have been developing an image sensor, "FEA-HARP", which consists of a field emitter array (FEA) and high-gain avalanche rushing amorphous photoconductor (HARP). This sensor will be used in an ultrahigh-sensitivity compact HDTV camera. We propose new operation methods for the FEA-HARP that maintain picture quality even when strong light enters the sensor. Experimental results show that blooming generation was suppressed by removing excess charges from the HARP target during horizontal blanking intervals.
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Hiroshi Ikeoka, Takayuki Hamamoto
2010 Volume 64 Issue 3 Pages
405-412
Published: March 01, 2010
Released on J-STAGE: June 01, 2010
JOURNAL
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We have been investigating real-time depth estimation techniques of a wide detectable range. These techniques involve the use of tilted optics imaging to use variance of depth of field on the horizontal planes of sharp focus. They need far fewer multiple focus images than the conventional passive methods do, e.g., the Depthfrom-Focus and the Depth-from-Defocus. Hence, our method gets rid of the bottleneck of conventional methods; the motion speed of optical mechanics is significantly slower than that of image processing parts. Therefore, it is suitable for applications that involve estimation of depth and that need a wide detectable range and real-time processing such as automation tasks.
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