Prof. Shoji Kawahito Profile

Prof. Shoji Kawahito

at Shizuoka Univ

SPIE Involvement:

Author

Publications (54)

Proceedings Article | 28 August 2024 Presentation

Presentation

Trigger-output event-driven x-ray astronomy SOI pixel sensors: development of large sensors with PDD structure and recent progress in digitization

Takeshi Go Tsuru, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Yuta Fuchita, Uzuki Iwakiri, Daisuke Izumi, Kousuke Kadoya, Shinichi Kamada, Rikuto Kawashima, Eisuke Kurogi, Koyo Magata, Miraku Kimura, Hikaru Mitani, Yuto Saitou, Yuto Sasaki, Asahi Shiokawa, Taiga Yoshida, Masataka Yukumoto, Yasushi Fukazawa, Yusuke Suda, Masaki Hashizume, Takaaki Tanaka, Rhyichi Azuma, Natsuki Terano, Kumiko Nobukawa, Takumi Kishimoto, Yuki Nishimura, Satoru Kuwano, Yoshihisa Kawabe, Masayoshi Nobukawa, Hirokazu Odaka, Hiroyuki Uchida, Mizuki Uenomachi, Tomonori Ikeda, Masamune Matsuda, Takuto Narita, Ikuo Kurachi, Hiromasa Suzuki, Hiroshi Nakajima, Kouichi Hagino, Hiroumi Matsuhashi, Yoshiyuki Onuki, Kenji Shimazoe, Takayoshi Kohmura, Yuusuke Uchida, Naoki Ito, Fumiya Shiga, Shun Tsunomachi, Toshiki Doi, Daiki Aoki, Yasuyuki Shimizu, Yuuki Takesue, Kaito Fujisawa, Yasuo Arai, Hideaki Katagiri, Mika Kagaya, Shoji Kawahito, Setsuo Sato, Hiroyuki Takahashi, Takehiro Takayanagi

Proceedings Volume PC13103, PC131030B (2024) https://doi.org/10.1117/12.3018637

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Proceedings Article | 13 March 2024 Presentation + Paper

Presentation + Paper

High-sensitivity 648x484-pixel CMOS image sensor for wide-field FLIM with four simultaneous time gates

Ibuki Ando, Kamel Mars, Keita Yasutomi, Shoji Kawahito, Keiichiro Kagawa

Proceedings Volume 12836, 1283605 (2024) https://doi.org/10.1117/12.3002329

KEYWORDS: Fluorescence lifetime imaging, Fluorescence, CMOS sensors, Image sensors, LIDAR, Copper indium disulfide, Modulators, Quantum gates, Spatial resolution, Quantum measurement

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SPIE Journal Paper | 18 January 2024 Open Access

Open Access

Motion-resistant three-wavelength spatial frequency domain imaging system with ambient light suppression using an 8-tap CMOS image sensor

Yu Feng, Chen Cao, Yuto Shimada, Keita Yasutomi, Shoji Kawahito, Gordon Kennedy, Anthony Durkin, Keiichiro Kagawa

JBO, Vol. 29, Issue 01, 016006, (January 2024) https://doi.org/10.1117/12.10.1117/1.JBO.29.1.016006

KEYWORDS: Image sensors, Imaging systems, Reflectivity, Tissues, Video, Biomedical optics, Image processing, Skin, In vivo imaging, Optical properties

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SignificanceWe present a motion-resistant three-wavelength spatial frequency domain imaging (SFDI) system with ambient light suppression using an 8-tap complementary metal-oxide semiconductor (CMOS) image sensor (CIS) developed at Shizuoka University. The system addresses limitations in conventional SFDI systems, enabling reliable measurements in challenging imaging scenarios that are closer to real-world conditions.AimOur study demonstrates a three-wavelength SFDI system based on an 8-tap CIS. We demonstrate and evaluate the system’s capability of mitigating motion artifacts and ambient light bias through tissue phantom reflectance experiments and in vivo volar forearm experiments.ApproachWe incorporated the Hilbert transform to reduce the required number of projected patterns per wavelength from three to two per spatial frequency. The 8-tap image sensor has eight charge storage diodes per pixel; therefore, simultaneous image acquisition of eight images based on multi-exposure is possible. Taking advantage of this feature, the sensor simultaneously acquires images for planar illumination, sinusoidal pattern projection at three wavelengths, and ambient light. The ambient light bias is eliminated by subtracting the ambient light image from the others. Motion artifacts are suppressed by reducing the exposure and projection time for each pattern while maintaining sufficient signal levels by repeating the exposure. The system is compared to a conventional SFDI system in tissue phantom experiments and then in vivo measurements of human volar forearms.ResultsThe 8-tap image sensor-based SFDI system achieved an acquisition rate of 9.4 frame sets per second, with three repeated exposures during each accumulation period. The diffuse reflectance maps of three different tissue phantoms using the conventional SFDI system and the 8-tap image sensor-based SFDI system showed good agreement except for high scattering phantoms. For the in vivo volar forearm measurements, our system successfully measured total hemoglobin concentration, tissue oxygen saturation, and reduced scattering coefficient maps of the subject during motion (16.5 cm/s) and under ambient light (28.9 lx), exhibiting fewer motion artifacts compared with the conventional SFDI.ConclusionsWe demonstrated the potential for motion-resistant three-wavelength SFDI system with ambient light suppression using an 8-tap CIS.

Proceedings Article | 7 March 2023 Presentation + Paper

Presentation + Paper

Demonstration of motion-resistant three-wavelength spatial frequency domain imaging system with ambient light suppression using an 8-tap CMOS image sensor

Yu Feng, Yuto Shimada, Chen Cao, Keita Yasutomi, Shoji Kawahito, Gordon Kennedy, Anthony Durkin, Keiichiro Kagawa

Proceedings Volume 12376, 123760D (2023) https://doi.org/10.1117/12.2649418

KEYWORDS: Image sensors, CMOS sensors, Tissues, Reflectivity, Imaging systems, Light scattering, Scattering, Cameras, Biological imaging, Sensors

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SPIE Journal Paper | 18 October 2022 Open Access

Open Access

Single event tolerance of x-ray silicon-on-insulator pixel sensors

Kouichi Hagino, Mitsuki Hayashida, Takayoshi Kohmura, Toshiki Doi, Shun Tsunomachi, Masatoshi Kitajima, Takeshi Go Tsuru, Hiroyuki Uchida, Kazuho Kayama, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Masataka Yukumoto, Kira Mieda, Syuto Yonemura, Tatsunori Ishida, Takaaki Tanaka, Yasuo Arai, Ikuo Kurachi, Hisashi Kitamura, Shoji Kawahito, Keita Yasutomi

JATIS, Vol. 8, Issue 04, 046001, (October 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.4.046001

KEYWORDS: X-rays, Tolerancing, Sensors, Silicon, Satellites, Ions, Particles, X-ray astronomy, Digital electronics, Satellite imaging

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Proceedings Article | 29 August 2022 Presentation

Presentation

Recent progress in development of trigger-output event-driven x-ray astronomy SOI pixel sensors

Takeshi Go Tsuru, Hiroyuki Uchida, Kazuho Kayama, Yuki Amano, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Masataka Yukumoto, Kira Mieda, Shuto Yonemura, Tatsunori Ishida, Daisuke Izumi, Uzuki Iwakiri, Towa Umeno, Rikuto Kawashima, Koyo Magata, Takaaki Tanaka, Hiromasa Suzuki, Takayoshi Kohmura, Kouichi Hagino, Masatoshi Kitajima, Toshiki Doi, Kumiko Nobukawa, Yasuo Arai, Ikuo Kurachi, Kenji Shimazoe, Shoji Kawahito, Keita Yasutomi

Proceedings Volume 12191, 121910K (2022) https://doi.org/10.1117/12.2628755

KEYWORDS: Sensors, X-ray astronomy, X-rays, Satellites, X-ray technology, Silicon, Oxides, Image resolution, Diodes, Digital electronics

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Proceedings Article | 2 March 2022 Presentation + Paper

Presentation + Paper

Demonstration of 3-band spatial frequency domain imaging using an 8-tap CMOS image sensor resistant to subject motion and ambient light

Kazuki Takada, Yuto Shimada, Keita Yasutomi, Shoji Kawahito, Gordon Kennedy, Anthony Durkin, Keiichiro Kagawa

Proceedings Volume 11951, 1195106 (2022) https://doi.org/10.1117/12.2608412

KEYWORDS: CMOS sensors, Scattering, Sensors, Absorption, Tissues, Reflectivity, Oxygen, Image sensors, Imaging systems, Spatial frequencies

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Proceedings Article | 2 March 2022 Presentation + Paper

Presentation + Paper

A 2x2-aperture 4-tap multi-modal tissue imager for multi-band SFDI and MELSCI

Yuto Shimada, Kazuki Takada, Hoang Son Nam, Kakeru Miyazaki, Keita Yasutomi, Shoji Kawahito, Christian Crouzet, Bernard Choi, Gordon Kennedy, Anthony Durkin, Keiichiro Kagawa

Proceedings Volume 11951, 1195107 (2022) https://doi.org/10.1117/12.2608397

KEYWORDS: Tissues, Imaging systems, CMOS sensors, Image sensors, Scattering, Tissue optics

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SPIE Journal Paper | 9 August 2021

Proton radiation hardness of x-ray SOI pixel sensors with pinned depleted diode structure

Mitsuki Hayashida, Kouichi Hagino, Takayoshi Kohmura, Masatoshi Kitajima, Keigo Yarita, Kenji Oono, Kousuke Negishi, Takeshi Tsuru, Takaaki Tanaka, Hiroyuki Uchida, Kazuho Kayama, Ryota Kodama, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Takahiro Hida, Masataka Yukumoto, Yasuo Arai, Ikuo Kurachi, Hisashi Kitamura, Shoji Kawahito, Keita Yasutomi

JATIS, Vol. 7, Issue 03, 036001, (August 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.3.036001

KEYWORDS: X-rays, Sensors, Diodes, Silicon, CMOS sensors, Capacitance, Satellites, CMOS technology, X-ray detectors, X-ray technology

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X-ray silicon-on-insulator (SOI) pixel sensors, “XRPIX,” are being developed for the next-generation x-ray astronomical satellite, “FORCE.” The XRPIX is fabricated with the SOI technology, which makes it possible to integrate a high-resistivity Si sensor and a low-resistivity Si complementary metal oxide semiconductor (CMOS) circuit. The CMOS circuit in each pixel is equipped with a trigger function, allowing us to read out outputs only from the pixels with x-ray signals at the timing of x-ray detection. This function thus realizes high throughput and high time resolution, which enables to employ anti-coincidence technique for background rejection. A new series of XRPIX named XRPIX6E developed with a pinned depleted diode (PDD) structure improves spectral performance by suppressing the interference between the sensor and circuit layers. When semiconductor x-ray sensors are used in space, their spectral performance is generally degraded owing to the radiation damage caused by high-energy protons. Therefore, before using an XRPIX in space, it is necessary to evaluate the extent of degradation of its spectral performance by radiation damage. Thus, we performed a proton irradiation experiment for XRPIX6E for the first time at Heavy Ion Medical Accelerator in Chiba in the National Institute of Radiological Sciences. We irradiated XRPIX6E with high-energy protons with a total dose of up to 40 krad, equivalent to 400 years of irradiation in orbit. The 40-krad irradiation degraded the energy resolution of XRPIX6E by 25 ± 3 % , yielding an energy resolution of 260.1 ± 5.6 eV at the full-width half maximum for 5.9 keV X-rays. However, the value satisfies the requirement for FORCE, 300 eV at 6 keV, even after the irradiation. It was also found that the PDD XRPIX has enhanced radiation hardness compared to previous XRPIX devices. In addition, we investigated the degradation of the energy resolution; it was shown that the degradation would be due to increasing energy-independent components, e.g., readout noise.

Proceedings Article | 30 March 2021 Presentation

Presentation

A multi-aperture multi-tap image sensor for simultaneous multi-band SFDI and multi-exposure laser speckle contrast blood flow imaging

Keiichiro Kagawa, Gordon Kennedy, Adrien Ponticorvo, Iori Shibata, Keita Yasutomi, Shoji Kawahito, Jun Tanida, Christian Crouzet, Bernard Choi, Anthony Durkin

Proceedings Volume 11651, 116510H (2021) https://doi.org/10.1117/12.2578055

KEYWORDS: Image sensors, Blood circulation, Speckle, Modulators, Laser speckle contrast imaging, Imaging devices, Cameras, Video, Tissue optics, Spatial frequencies

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Proceedings Article | 9 March 2021 Presentation + Paper

Presentation + Paper

Spatio-temporal frequency domain imaging using time-resolving CMOS image sensor and stripe pattern projection

K. Takada, K, Osada, M. Machida, Y. Hoshi, K. Yasutomi, S. Kawahito, K. Kagawa

Proceedings Volume 11639, 116391C (2021) https://doi.org/10.1117/12.2577981

KEYWORDS: CMOS sensors, Tissues, Near infrared spectroscopy, Monte Carlo methods, Brain, Skull, Skin, Scattering, Modulators, Light scattering

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Proceedings Article | 28 December 2020 Presentation + Paper

Presentation + Paper

Proton radiation hardness of x-ray SOI pixel detectors with pinned depleted diode structure

Mitsuki Hayashida, Takayoshi Kohmura, Kouichi Hagino, Kenji Oono, Kousuke Negishi, Keigo Yarita, Masatoshi Kitajima, Takeshi G. Tsuru, Takaaki Tanaka, Hiroyuki Uchida, Kazuho Kayama, Ryota Kodama, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Takahiro Hida, Masataka Yukumoto, Yasuo Arai, Ikuo Kurachi, Tsuyoshi Hamano, Hisashi Kitamura, Shoji Kawahito, Keita Yasutomi

Proceedings Volume 11454, 114540P (2020) https://doi.org/10.1117/12.2562392

KEYWORDS: Sensors, X-rays, X-ray detectors, Diodes, Satellites, CMOS sensors, Detector development, X-ray astronomy, Astronomy, Silicon

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Proceedings Article | 21 February 2020 Paper

Paper

A time-resolved near-infrared spectroscopy based on CMOS image sensor

De Xing Lioe, Masashi Hakamata, Keita Yasutomi, Keiichiro Kagawa, Masatsugu Niwayama, Yasuko Fukushi, Seiji Yamamoto, Shoji Kawahito

Proceedings Volume 11234, 112340P (2020) https://doi.org/10.1117/12.2545581

KEYWORDS: Near infrared spectroscopy, CMOS sensors, Absorption, Sensors, Scattering, Laser scattering, Reflectivity, Image sensors, Light sources, Light scattering

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Proceedings Article | 17 February 2020 Presentation + Paper

Presentation + Paper

A multiplexed confocal FLIM microscope with 4-taps time-gated imager

Morgan Richards, Yuya Shirakawa, Fares Badr, Keiichiro Kagawa, Shoji Kawahito, Qiyin Fang

Proceedings Volume 11245, 1124512 (2020) https://doi.org/10.1117/12.2550208

KEYWORDS: Confocal microscopy, Imaging systems, Fluorescence lifetime imaging, Microscopes, Sensors, Multiplexing, Luminescence, Relays, Microlens array, Biomedical optics

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Proceedings Article | 21 February 2019 Paper

Paper

A real-time driver monitoring system using a high sensitivity camera

Leyi Tan, Masashi Hakamata, Chen Cao, Keiichiro Kagawa, Norimichi Tsumura, Shoji Kawahito

Proceedings Volume 10883, 108831G (2019) https://doi.org/10.1117/12.2507181

KEYWORDS: Heart, Video, Cameras, Signal detection, Imaging systems, Independent component analysis, Electronic filtering, Nervous system, Skin, RGB color model

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Proceedings Article | 1 August 2018 Presentation + Paper

Presentation + Paper

Kyoto's event-driven x-ray astronomy SOI pixel sensor for the FORCE mission

Takeshi Tsuru, Hideki Hayashi, Katsuhiro Tachibana, Soudai Harada, Hiroyuki Uchida, Takaaki Tanaka, Yasuo Arai, Ikuo Kurachi, Koji Mori, Ayaki Takeda, Yusuke Nishioka, Nobuaki Takebayashi, Shoma Yokoyama, Kohei Fukuda, Takayoshi Kohmura, Kouichi Hagino, Kenji Ohno, Kohsuke Negishi, Keigo Yarita, Shoji Kawahito, Keiichiro Kagawa, Keita Yasutomi, Sumeet Shrestha, Shunta Nakanishi, Hiroki Kamehama, Hideaki Matsumura

Proceedings Volume 10709, 107090H (2018) https://doi.org/10.1117/12.2312098

KEYWORDS: Sensors, X-rays, Silicon, X-ray astronomy, CMOS sensors, X-ray imaging, X-ray detectors, Imaging devices

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Proceedings Article | 22 February 2017 Paper

Paper

A high performance multi-tap CMOS lock-in pixel image sensor for biomedical applications

Min-Woong Seo, Yuya Shirakawa, Keiichiro Kagawa, Keita Yasutomi, Shoji Kawahito

Proceedings Volume 10076, 100760V (2017) https://doi.org/10.1117/12.2255951

KEYWORDS: Sensors, CMOS sensors, Fluorescence lifetime imaging, Biomedical optics, Microscopy, Signal detection, Image sensors, Modulation, Imaging systems, Signal to noise ratio, Modulators, Prototyping, Photodiodes, Analog electronics

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Proceedings Article | 20 February 2017 Paper

Paper

Design of an 8-tap CMOS lock-in pixel with lateral electric field charge modulator for highly time-resolved imaging

Yuya Shirakawa, Min-Woong Seo, Keita Yasutomi, Keiichiro Kagawa, Nobukazu Teranishi, Shoji Kawahito

Proceedings Volume 10108, 101080N (2017) https://doi.org/10.1117/12.2251788

KEYWORDS: Signal detection, Modulators, Real time imaging, Imaging devices, Fluorescence lifetime imaging, CMOS sensors, Microscopy, Life sciences, Luminescence, Computer aided design, Imaging systems, Image processing

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Proceedings Article | 20 February 2017 Paper

Paper

A time-of-flight range image sensor using high-speed 4-tap lock-in pixels

A. Komazawa, H. Trang, T. Takasawa, S. Aoyama, K. Yasutomi, K. Kagawa, S. Kawahito

Proceedings Volume 10328, 1032806 (2017) https://doi.org/10.1117/12.2270543

KEYWORDS: Time of flight range image sensors, Modulators, Imaging systems, Image resolution, Electrons, Demodulation, Image processing, Photodiodes, Sensors, Calibration

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Proceedings Article | 16 February 2017 Paper

Paper

Spectroscopic analysis of autofluorescence distribution in digestive organ for unstained metabolism-based tumor detection

Hidenobu Arimoto, Atsushi Iwata, Keiichiro Kagawa, Yoji Sanomura, Shigeto Yoshida, Shoji Kawahito, Shinji Tanaka

Proceedings Volume 10068, 100681L (2017) https://doi.org/10.1117/12.2250776

KEYWORDS: Spectroscopy, Confocal microscopy, Tumors, Collagen, Luminescence, Tissue optics, Optical filters, Image sensors, Tissues, Bandpass filters

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Proceedings Article | 5 May 2016 Paper

Paper

Development of low read noise high conversion gain CMOS image sensor for photon counting level imaging

Min-Woong Seo, Shoji Kawahito, Keiichiro Kagawa, Keita Yasutomi

Proceedings Volume 9858, 985809 (2016) https://doi.org/10.1117/12.2229025

KEYWORDS: CMOS sensors, Photon counting, Image sensors, Capacitance, Image processing, Imaging systems, Analog electronics, Sensors, Interference (communication), Electrons

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Proceedings Article | 7 March 2016 Presentation + Paper

Presentation + Paper

Multi-aperture ultra-high-speed imaging with lateral electric field charge modulators

K. Kagawa, F. Mochizuki, M.-W. Seo, K. Yasutomi, S. Kawahito

Proceedings Volume 9720, 972003 (2016) https://doi.org/10.1117/12.2214273

KEYWORDS: CMOS sensors, Camera shutters, Image sensors, Image compression, Cameras, Modulation, Modulators, Charge-coupled devices, Video, Image resolution

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Proceedings Article | 7 March 2016 Presentation + Paper

Presentation + Paper

A CMOS image sensor using high-speed lock-in pixels for stimulated Raman scattering

DeXing Lioe, Kamel Mars, Taishi Takasawa, Keita Yasutomi, Keiichiro Kagawa, Mamoru Hashimoto, Shoji Kawahito

Proceedings Volume 9720, 97200J (2016) https://doi.org/10.1117/12.2213906

KEYWORDS: CMOS sensors, Raman scattering, Modulation, Amplifiers, Raman spectroscopy, Imaging spectroscopy, Spectroscopy, Image sensors, Modulators, Photodiodes, Interference (communication), Signal detection, Laser sources, Capacitors

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Proceedings Article | 26 August 2015 Paper

Paper

A low-noise wide-dynamic-range event-driven detector using SOI pixel technology for high-energy particle imaging

Sumeet Shrestha, Hiroki Kamehama, Shoji Kawahito, Keita Yasutomi, Keiichiro Kagawa, Ayaki Takeda, Takeshi Go Tsuru, Yasuo Arai

Proceedings Volume 9593, 95930X (2015) https://doi.org/10.1117/12.2188019

KEYWORDS: Sensors, Signal detection, Particles, CMOS sensors, X-rays, X-ray detectors, Transistors, Capacitors, Silicon, Logic

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Proceedings Article | 13 March 2015 Paper

Paper

A high-sensitivity 2x2 multi-aperture color camera based on selective averaging

Bo Zhang, Keiichiro Kagawa, Taishi Takasawa, Min-Woong Seo, Keita Yasutomi, Shoji Kawahito

Proceedings Volume 9403, 94030C (2015) https://doi.org/10.1117/12.2082780

KEYWORDS: Cameras, Sensors, Image quality, Interference (communication), Imaging systems, CMOS sensors, Distortion, Prototyping, Image sensors, Signal to noise ratio

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Proceedings Article | 22 June 2014 Paper

Paper

Development and performance of Kyoto's x-ray astronomical SOI pixel (SOIPIX) sensor

Takeshi Tsuru, Hideaki Matsumura, Ayaki Takeda, Takaaki Tanaka, Shinya Nakashima, Yasuo Arai, Koji Mori, Ryota Takenaka, Yusuke Nishioka, Takayoshi Kohmura, Takaki Hatsui, Takashi Kameshima, Kyosuke Ozaki, Yoshiki Kohmura, Tatsuya Wagai, Dai Takei, Shoji Kawahito, Keiichiro Kagawa, Keita Yasutomi, Sumeet Shrestha, Hiroki Kamehama

Proceedings Volume 9144, 914412 (2014) https://doi.org/10.1117/12.2057158

KEYWORDS: X-rays, X-ray astronomy, Sensors, Charge-coupled devices, X-ray detectors, CMOS sensors, X-ray imaging, Analog electronics, X-ray technology, Satellites

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Proceedings Article | 21 May 2014 Paper

Paper

A 33-Mpixel 120-fps CMOS image sensor using 0.11-μm CIS process

Toshio Yasue, Tetsuya Hayashida, Jun Yonai, Kazuya Kitamura, Toshihisa Watabe, Hiroshi Ootake, Hiroshi Shimamoto, Tomohiko Kosugi, Takashi Watanabe, Satoshi Aoyama, Shoji Kawahito

Proceedings Volume 9100, 910005 (2014) https://doi.org/10.1117/12.2049145

KEYWORDS: Image sensors, Image processing, Sensors, CMOS sensors, Prototyping, Cameras, Cadmium sulfide, Analog electronics, Quantum efficiency, Image resolution

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Proceedings Article | 4 March 2014 Paper

Paper

A high fill-factor low dark leakage CMOS image sensor with shared-pixel design

Min-Woong Seo, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito

Proceedings Volume 9022, 90220M (2014) https://doi.org/10.1117/12.2040897

KEYWORDS: Transistors, CMOS sensors, Imaging systems, Photodiodes, Amplifiers, Quantum efficiency, Signal to noise ratio, Stereolithography, Analog electronics, CMOS technology

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Proceedings Article | 4 March 2014 Paper

Paper

10×10-pixel 606kS/s multi-point fluorescence correlation spectroscopy CMOS image sensor

Keiichiro Kagawa, Taishi Takasawa, Zhang Bo, Min-Woong Seo, Kaita Imai, Jotaro Yamamoto, Masataka Kinjo, Susumu Terakawa, Keita Yasutomi, Shoji Kawahito

Proceedings Volume 8947, 894713 (2014) https://doi.org/10.1117/12.2041131

KEYWORDS: CMOS sensors, Fluorescence correlation spectroscopy, Cadmium sulfide, Prototyping, Electrons, Photodiodes, Image sensors, Analog electronics, Diodes, CMOS technology

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Proceedings Article | 4 March 2014 Paper

Paper

A time-resolved image sensor for tubeless streak cameras

Keita Yasutomi, SangMan Han, Min-Woong Seo, Taishi Takasawa, Keiichiro Kagawa, Shoji Kawahito

Proceedings Volume 9022, 902202 (2014) https://doi.org/10.1117/12.2041150

KEYWORDS: Streak cameras, Imaging systems, CMOS sensors, Image sensors, Logic, Picosecond phenomena, Modulation, Pulse generators, Clocks, Sensors

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Proceedings Article | 4 March 2014 Paper

Paper

An indirect time-of-flight measurement technique for sub-mm range resolution using impulse photocurrent response

Takahiro Usui, Keita Yasutomi, Han San Man, Taishi Takasawa, Keiichiro Kagawa, Shoji Kawahito

Proceedings Volume 9022, 90220W (2014) https://doi.org/10.1117/12.2041160

KEYWORDS: Modulation, Light sources, Sensors, Distance measurement, Phase shift keying, Pulsed laser operation, Picosecond phenomena, Clocks, Imaging systems, Distortion

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Proceedings Article | 4 March 2014 Paper

Paper

Experiment on digital CDS with 33-M pixel 120-fps super hi-vision image sensor

J. Yonai, T. Yasue, K. Kitamura, T. Hayashida, T. Watabe, H. Shimamoto, S. Kawahito

Proceedings Volume 9022, 90220B (2014) https://doi.org/10.1117/12.2038716

KEYWORDS: Cadmium sulfide, Image sensors, Video, Digital electronics, Data conversion, Analog electronics, Digital signal processing, Signal processing, CMOS sensors, Copper indium disulfide

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Proceedings Article | 4 March 2014 Paper

Paper

A CMOS time-of-flight range image sensor using draining only modulation structure

Sangman Han, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito

Proceedings Volume 9022, 90220P (2014) https://doi.org/10.1117/12.2041184

KEYWORDS: Modulation, Time of flight range image sensors, Imaging systems, Image processing, Photodiodes, CMOS sensors, Sensors, Electrons, Doping, Amplifiers

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This paper presents new structure and method of charge modulation for CMOS ToF range image sensors using pinned photodiodes. Proposed pixel structure, the draining only modulator (DOM), allows us to achieve high-speed charge transfer by generating lateral electric field from the pinned photo-diode (PPD) to the pinned storage-diode (PSD). Generated electrons by PPD are transferred to the PSD or drained off through the charge draining gate (TXD). This structure realizes trapping-less charge transfer from the PPD to PSD. To accelerate the speed of charge transfer, the generation of high lateral electric field is necessary. To generate the electric field, the width of the PPD is changed along the direction of the charge transfer. The PPD is formed by the p+ and n layer on the p-substrate. The PSD is created by doping another n type layer for higher impurity concentration than that of the n layer in the PPD. This creates the potential difference between the PPD and PSD. Another p layer underneath the n-layer of the PSD is created for preventing the injection of unwanted carrier from the substrate to the PSD. The range is calculated with signals in the three consecutive sub-frames; one for delay sensitive charge by setting the light pulse timing at the edge of TXD pulse, another for delay independent charge by setting the light pulse timing during the charge transfer, and the other for ambient light charge by setting the light pulse timing during the charge draining. To increase the photo sensitivity while realizing high-speed charge transfer, the pixel consists of 16 sub-pixels and a source follower amplifier. The outputs of 16 sub-pixels are connected to a charge sensing node which has MOS capacitor for increasing well capacity. The pixel array has 313(Row) x 240(Column) pixels and the pixel pitch is 22.4μm. A ToF range imager prototype using the DOM pixels is designed and implemented with 0.11um CMOS image sensor process. The accumulated signal intensity in the PSD as a function of the TXD gate voltage is measured. The ratio of the signal for the TXD off to the signal for the TXD on is 33:1. The response of the pixel output as a function of the light pulse delay has also been measured.

Proceedings Article | 4 March 2014 Paper

Paper

A stimulated Raman scattering imager using high-speed lateral electric field modulator and lock-in pixels amplifiers

Kamel Mars, Beak Guseul, Sang Man Han, Taishi Takasawa, Keita Yasutomi, Keiichiro Kagawa, Mamoru Hashimoto, Shoji Kawahito

Proceedings Volume 9022, 90220D (2014) https://doi.org/10.1117/12.2042471

KEYWORDS: Signal detection, Amplifiers, Modulators, Raman scattering, Modulation, Imaging systems, Clocks, Signal processing, Photodiodes, Device simulation

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Proceedings Article | 19 February 2013 Paper

Paper

A custom CMOS imager for multi-beam laser scanning microscopy and an improvement of scanning speed

Min-Woong Seo, Keiichiro Kagawa, Keita Yasutomi, Shoji Kawahito

Proceedings Volume 8659, 865905 (2013) https://doi.org/10.1117/12.2004965

KEYWORDS: Confocal microscopy, Imaging systems, Laser scanners, Microlens array, Modulation, Microscopy, Image resolution, Multiplexers, Cadmium sulfide, Photodiodes

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Proceedings Article | 15 February 2012 Paper

Paper

A CMOS imager using focal-plane pinhole effect for confocal multibeam scanning microscopy

Min-Woong Seo, An Wang, Zhuo Li, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito

Proceedings Volume 8298, 829807 (2012) https://doi.org/10.1117/12.908285

KEYWORDS: Confocal microscopy, Imaging systems, Microscopy, Microscopes, Sensors, Photodiodes, CMOS sensors, CMOS technology, Standards development, Active sensors

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Proceedings Article | 3 February 2012 Paper

Paper

Deep-focus compound-eye camera with polarization filters for 3D endoscopes

Keiichiro Kagawa, Eiji Tanaka, Kenji Yamada, Shoji Kawahito, Jun Tanida

Proceedings Volume 8227, 822714 (2012) https://doi.org/10.1117/12.908415

KEYWORDS: Polarization, Cameras, Endoscopes, Optical filters, Imaging systems, Super resolution, Point spread functions, Tissues, Prototyping, Wavefronts

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Proceedings Article | 17 February 2011 Paper

Paper

A CMOS image sensor with draining only modulation pixels for fluorescence lifetime imaging

Zhuo Li, Keita Yasutomi, Taishi Takasawa, Shinya Itoh, Shoji Kawahito

Proceedings Volume 7875, 78750D (2011) https://doi.org/10.1117/12.877775

KEYWORDS: Luminescence, Diodes, Fluorescence lifetime imaging, Modulation, CMOS sensors, Signal detection, Image processing, Image sensors, Sensors, Neodymium

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Proceedings Article | 26 January 2010 Paper

Paper

High-speed charge transfer pinned-photodiode for a CMOS time-of-flight range image sensor

Hiroaki Takeshita, Tomonari Sawada, Tetsuya Iida, Keita Yasutomi, Shoji Kawahito

Proceedings Volume 7536, 75360R (2010) https://doi.org/10.1117/12.846277

KEYWORDS: Time of flight range image sensors, Photodiodes, Imaging systems, CMOS sensors, Sensors, Image sensors, Light emitting diodes, CMOS technology, Silicon, Diodes

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Proceedings Article | 26 January 2010 Paper

Paper

A three-phase time-correlation image sensor using pinned photodiode active pixels

Sangman Han, Tomohiro Iwahori, Tomonari Sawada, Shoji Kawahito, Shigeru Ando

Proceedings Volume 7536, 75360S (2010) https://doi.org/10.1117/12.846532

KEYWORDS: Image sensors, Modulation, Photodiodes, Sensors, Transistors, Capacitance, Electrons, CMOS technology, Capacitors, Doping

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Proceedings Article | 29 February 2008 Paper

Paper

Noise calculation model and analysis of high-gain readout circuits for CMOS image sensors

Shoji Kawahito, Shinya Itoh

Proceedings Volume 6816, 68160D (2008) https://doi.org/10.1117/12.777641

KEYWORDS: Amplifiers, CMOS sensors, Capacitors, Interference (communication), Capacitance, Transistors, Cadmium sulfide, Analog electronics, Circuit switching, Digital signal processing

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Proceedings Article | 29 February 2008 Paper

Paper

A wide dynamic range CMOS image sensor with dual charge storage in a pixel and a multiple sampling technique

Suhaidi Shafie, Shoji Kawahito

Proceedings Volume 6816, 681606 (2008) https://doi.org/10.1117/12.767252

KEYWORDS: CMOS sensors, Signal to noise ratio, Sensors, Image sensors, Photodiodes, Amplifiers, Switching, Cameras, Cadmium sulfide, Capacitors

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Proceedings Article | 6 February 2006 Paper

Paper

An ultra wide dynamic range CMOS image sensor with a linear response

Jong Ho Park, Mitsuhito Mase, Shoji Kawahito, Masaaki Sasaki, Yasuo Wakamori, Yukihiro Ohta

Proceedings Volume 6068, 60680B (2006) https://doi.org/10.1117/12.642843

KEYWORDS: Image sensors, Amplifiers, Prototyping, Signal to noise ratio, CMOS sensors, Capacitors, Cadmium sulfide, Sensors, Scanners, Holmium

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Proceedings Article | 26 January 2006 Paper

Paper

A QVGA-size CMOS time-of-flight range image sensor with background light charge draining structure

Takeo Ushinaga, Izhal Abdul Halin, Tomonari Sawada, Shoji Kawahito, Mitsuru Homma, Yasunari Maeda

Proceedings Volume 6056, 605604 (2006) https://doi.org/10.1117/12.642022

KEYWORDS: Sensors, Electrons, Imaging systems, 3D image processing, Time of flight range image sensors, Spatial resolution, Light emitting diodes, CMOS sensors, Image sensors, Scanners

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Proceedings Article | 17 March 2005 Paper

Paper

CMOS active pixel image sensor with in-pixel CDS for high-speed cameras

Toru Inoue, Shinji Takeuchi, Shoji Kawahito

Proceedings Volume 5580, (2005) https://doi.org/10.1117/12.567313

KEYWORDS: Image sensors, Cadmium sulfide, Sensors, Capacitance, Amplifiers, CMOS sensors, Photodiodes, High speed cameras, Capacitors, Camera shutters

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Proceedings Article | 7 March 2005 Paper

Paper

Design and implementation of a one-chip wireless camera device for a capsule endoscope

Shinya Itoh, Shoji Kawahito, Tomoyuki Akahori, Susumu Terakawa

Proceedings Volume 5677, (2005) https://doi.org/10.1117/12.587726

KEYWORDS: Cameras, Clocks, Endoscopes, Modulators, Power supplies, Capacitors, CMOS sensors, Image processing, Prototyping, Analog electronics

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Proceedings Article | 25 February 2005 Paper

Paper

Parallel image compression circuit for high-speed cameras

Yukinari Nishikawa, Shoji Kawahito, Toru Inoue

Proceedings Volume 5671, (2005) https://doi.org/10.1117/12.588030

KEYWORDS: Image compression, High speed cameras, Field programmable gate arrays, Image processing, Multiplexers, Parallel processing, Computer programming, Scanners, Data conversion, Logic

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Proceedings Article | 7 June 2004 Paper

Paper

CMOS active pixel image sensor with in-pixel CDS for high-speed cameras

Toru Inoue, Shinji Takeuchi, Shoji Kawahito

Proceedings Volume 5301, (2004) https://doi.org/10.1117/12.533598

KEYWORDS: Cadmium sulfide, Sensors, Image sensors, Photodiodes, CMOS sensors, Amplifiers, Capacitance, Transistors, Capacitors, Diffusion

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Proceedings Article | 16 April 2004 Paper

Paper

Active pixel circuits for CMOS time-of-flight range image sensors

Shoji Kawahito, Izhal Halin

Proceedings Volume 5302, (2004) https://doi.org/10.1117/12.533480

KEYWORDS: Sensors, Capacitors, Amplifiers, Switches, Range imaging, Digital signal processing, Electrons, CMOS technology, Photons, Signal processing

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Proceedings Article | 16 May 2003 Paper

Paper

Photon count imaging using an extremely small capacitor and a high-precision low-noise quantizer

Shoji Kawahito, Shinya Itoh

Proceedings Volume 5017, (2003) https://doi.org/10.1117/12.479714

KEYWORDS: Photon counting, Capacitors, Quantization, CMOS sensors, Sensors, Amplifiers, Imaging systems, Interference (communication), Capacitance, Electrons

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Proceedings Article | 16 May 2003 Paper

Paper

Method to extend dynamic range of CMOS image sensor using different frame-rate readout

Masaaki Sasaki, Shoji Kawahito, Mitsuhito Mase, Yoshiaki Tadokoro

Proceedings Volume 5017, (2003) https://doi.org/10.1117/12.482357

KEYWORDS: Signal to noise ratio, Amplifiers, Analog electronics, CMOS sensors, Interference (communication), Sensors, Diodes, Image sensors, Electrons, Image quality

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Proceedings Article | 16 May 2003 Paper

Paper

Noise calculation model for high-gain column amplifiers of CMOS image sensors

Shoji Kawahito, Nobuhiro Kawai

Proceedings Volume 5017, (2003) https://doi.org/10.1117/12.479713

KEYWORDS: Amplifiers, Capacitors, CMOS sensors, Switches, Capacitance, Device simulation, Transistors, Electrons, Interference (communication), Sensors

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Proceedings Article | 24 April 2002 Paper

Paper

Low-noise signal detection technique in CMOS image sensors using frame oversampling and nondestructive high-speed readout

Shoji Kawahito, Nobuhiro Kawai

Proceedings Volume 4669, (2002) https://doi.org/10.1117/12.463417

KEYWORDS: Signal to noise ratio, Amplifiers, CMOS sensors, Nondestructive evaluation, Interference (communication), Quantization, Denoising, Sensors, Signal detection, Charge-coupled devices

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Proceedings Article | 20 July 1998 Paper

Paper

Flip-chip packaged CMOS chemical microsystem for detection of volatile organic compounds

Andreas Koll, Shoji Kawahito, Felix Mayer, Christoph Hagleitner, D. Scheiwiller, Oliver Brand, Henry Baltes

Proceedings Volume 3328, (1998) https://doi.org/10.1117/12.320173

KEYWORDS: Sensors, Microsystems, Capacitors, Packaging, Polymers, Ceramics, CMOS sensors, Chemical analysis, Industrial chemicals, Microsensors

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Showing 5 of 54 publications

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