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High-Speed Fluorescence Imaging System for Freely Moving Animals
Published in Khosla Ajit, Kim Dongsoo, Iniewski Krzysztof, Optical Imaging Devices, 2017
An active pixel sensor (APS) uses intrapixel charge transfer along with an in-pixel amplifier (Fossum, 1993). One advantage of the active pixel over a passive pixel is the in-pixel amplification of the photogenerated charge inside the pixel, which suppresses the noise in the readout path. Also, the output of the photodiode is buffered by the in-pixel amplifier, and reading is nondestructive and much faster than with PPS. The nondestructive read, along with other on-chip circuitry, allows true correlated double sampling (CDS), low temporal noise operation, and fixed-pattern noise reduction.
Analog Electronics for HVCMOS Sensors
Published in Renato Turchetta, Krzysztof Iniewski, Analog Electronics for Radiation Detection, 2017
In the case of a typical CMOS active pixel sensor (APS) for visible-light detection in digital cameras, every pixel contains a reverse-biased photosensitive diode (n-well) and a few transistors, which are used to amplify, clear, and read out the signal. Due to these additional devices, the surface of a pixel is not 100% sensitive to light, and a portion of the incident light is not detected. This signal loss leads to a slight decrease of the light sensitivity of a camera.
Synthesis and electronic structure of a series of first-row transition-metal pyrazine(diimine) complexes in two oxidation states
Published in Journal of Coordination Chemistry, 2022
Daniela Sanchez Arana, Jaylan R. Billups, Bruno Donnadieu, Sidney E. Creutz
Single crystal X-ray diffraction was measured using a Bruker AXS D8 Venture system equipped with a Photon 100 CMOS active pixel sensor detector. Either copper Kα or molybdenum Kα radiation was used for the measurements, provided by a dual microfocus Incoatec IµS 3.0 source. Crystals were mounted on a cryoloop using oil cryoprotectant. Crystallographic information for 1–6 is provided in Tables 5 and 6 (further specific crystallographic information provided in the Supplementary Information) and/or in the corresponding cif files. CCDC 2167041 (1), 2167042 (2), 2167046 (3), 2191703 (4), 2167043 (5), and 2167045 (6) contain the supplementary crystallographic data for this paper. The data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.
CMOS Implementation of Time Delay Integration (TDI) for Imaging Applications: A Brief Review
Published in IETE Technical Review, 2020
Sushil Kumar Semwal, Raghvendra Sahai Saxena
A new concept of TDI in CMOS was proposed in 2001 by Pain et al. [6]. Figure 3 shows the proposed block diagram for the concept implementation. As shown in the figure, the proposed circuit consisted of a CMOS M × N active pixel sensor (APS) array connected column-wise to M × N array of low-noise, high-speed analog charge integrators and then digitized by column-wise ADCs. This work delineates the inherent complexity of architecture due to large number of switching between storage elements and keeping the track of charge w.r.t. its respective pixel though it was also stated that this problem can be overcome in future with different possible architectures of CMOS TDI-based circuits. Since then, several people had referred this work and implemented different architectures in CMOS TDI for various imaging applications.
Experimental and analytical study of passive earth pressure behind a vertical rigid retaining wall rotating about base
Published in European Journal of Environmental and Civil Engineering, 2022
Nikon D750 digital single-lens reflex (DSLR) with CMOS (complementary metal oxide semiconductor) sensor (35.9 × 24.0 mm) was chosen for imaging which offers a resolution of 24.3MP (mega pixel) with a rolling shutter arrangement. This camera has some advantages over expensive CCD cameras (charge coupled camera) like inbuilt APS (active pixel sensor) technology, better affordability, and simple operational module. Several researchers (Mishra et al., 2017; Morse et al., 2014) have conducted PIV analysis using DSLR cameras and incurred satisfactory results. Though it performs poorly under low light intensity giving rise to high signal to noise ratio (SNR), it can be fixed by outsourcing external lights. Two 40 Watt LEDs (light-emitting diode) were employed on either side of setup at an inclination of 45̊ to the central axis (Nishimura et al., 2016) to compensate for low optical sensitivity. An uninterrupted power supply was ensured for the lighting system. Control points were placed uniformly in a grid pattern over the entire area of the transparent side wall in order to obtain the full field displacement contours in object space from the image space. It is well known fact that the better spatial variation of pixels over the entire region will yield good results. Hence, artificial seeding such as dyed sands was infused with the soil to create more contrasts in the images. An artificial seeding ratio of 0.4 (preferably ranges from 0.3 to 0.7 suggested by Stanier et al. (2016) was adopted in the present case. A series of images were taken during the test in a continuous shooting mode and later analysed using the open source GeoPIV_RG Matlab code. It was run in a system having the configuration of 64 bit Windows 7 OS with an Intel core i5 processor and 12 GB RAM.