Image Sensor

An image sensor of the type for providing charge multiplication by impact ionisation has plurality of multiplication elements. Each element is arranged to receive charge from photosensitive elements of an image area and each element comprises a sequence of electrodes to move charge along a transport path. Each of the electrodes has an edge defining a boundary with a first electrode, a maximum width across the charge transport path and a leading edge that defines a boundary with a second electrode, the leading edge having one or more changes of direction so that the length of the edge is greater than the maximum width of the charge multiplication electrode across the charge transport path. Various arrangements with such changes of direction are provided including a zigzag saw-tooth arrangement, a castellated arrangement and a triangular arrangement

Young children retain fast mapped object labels better than shape, color, and texture words

We compared short- and long-term retention of fast mapped color, shape and texture words as well as object labels. In an exposure session, 354 3- and 4-year-old children were shown a set of two familiar and three novel stimuli. One of the novel stimuli was labeled with a new object label, color, shape or texture word. Retention of the mapping between the new word and the novel object or property was measured either five minutes or one week later. After five minutes, retention was significantly above chance in all conditions. However, after one week only the mappings for object labels were retained above chance levels. Our findings suggest that fast mapped object labels are retained long-term better than color, shape and texture words. The results also highlight the importance of comparing short- and long-term retention when studying children’s word learning

Design and Performance of a Pinned Photodiode CMOS Image Sensor Using Reverse Substrate Bias

A new pinned photodiode (PPD) CMOS image sensor with reverse biased p-type substrate has been developed and characterized. The sensor uses traditional PPDs with one additional deep implantation step to suppress the parasitic reverse currents, and can be fully depleted. The first prototypes have been manufactured on an 18 µm thick, 1000 Ω·cm epitaxial silicon wafers using 180 nm PPD image sensor process. Both front-side illuminated (FSI) and back-side illuminated (BSI) devices were manufactured in collaboration with Teledyne e2v. The characterization results from a number of arrays of 10 µm and 5.4 µm PPD pixels, with different shape, the size and the depth of the new implant are in good agreement with device simulations. The new pixels could be reverse-biased without parasitic leakage currents well beyond full depletion, and demonstrate nearly identical optical response to the reference non-modified pixels. The observed excessive charge sharing in some pixel variants is shown to not be a limiting factor in operation. This development promises to realize monolithic PPD CIS with large depleted thickness and correspondingly high quantum efficiency at near-infrared and soft X-ray wavelengths

Fully Depleted, Monolithic Pinned Photodiode CMOS Image Sensor Using Reverse Substrate Bias

A new pixel design using pinned photodiode (PPD) in a 180 nm CMOS image sensor (CIS) process has been developed as a proof of principle. The sensor can be fully depleted by means of reverse bias applied to the substrate, and the principle of operation is applicable to very thick sensitive volumes. Additional n-type implants under the in-pixel p-wells have been added to the manufacturing process in order to eliminate the large parasitic substrate current that would otherwise be present in a normal device. The new design exhibits nearly identical electro-optical performance under reverse bias as the reference PPD pixel it is based on, and the leakage current is effectively suppressed. The characterisation results from both front- and back-side illuminated sensor variants show that the epitaxial layer is fully depleted

Get your facts right : preschoolers systematically extend both object names and category-relevant facts

There is an ongoing debate over the extent to which language development shares common processing mechanisms with other domains of learning. It is well-established that toddlers will systematically extend object labels to similarly-shaped category exemplars (e.g., Landau, Smith, & Jones, 1988; Markman & Hutchinson, 1984). However, previous research is inconclusive as to whether young children will similarly extend factual information about an object to other category members. We explicitly contrast facts varying in category relevance, and test for extension using two different tasks. Three- to four-year-olds (N = 61) were provided with one of three types of information about a single novel object: a category-relevant fact (‘it’s from a place called Modi’), a category-irrelevant fact (‘my uncle gave it to me’), or an object label (‘it’s called a Modi’). At test, children provided with the object name or category-relevant fact were significantly more likely to display systematic category extension than children who learnt the category-irrelevant fact. Our findings contribute to a growing body of evidence that the mechanisms responsible for word learning may be domain-general in nature

Colony and individual life-history responses to temperature in a social insect pollinator

Pollinating insects are of major ecological and commercial importance, yet they may be facing ecological disruption from a changing climate. Despite this threat, few studies have investigated the life-history responses of pollinators to experimentally controlled changes in temperature, which should be especially informative for species with complex life histories such as eusocial insects. This study uses the key pollinator Bombus terrestris, a eusocial bumble bee with an annual colony cycle, to determine how temperature affects life-history traits at both individual and colony levels. In two laboratory experiments, we reared B. terrestris colonies at either 20°C or 25°C, and measured differences in a set of life-history traits including colony longevity, queen longevity, worker longevity, production of workers, production of sexuals (queen and male production) and growth schedule, as well as effects on thermoregulatory behaviours. Higher rearing temperature had a significant positive effect on colony longevity in one of the two experiments but no significant effects on queen or worker longevity. Higher rearing temperature significantly increased colony size but did not affect the timing of peak colony size. It was also associated with significantly higher queen production but had no effect on the production of workers or males or the timing of male production. Higher temperature colonies exhibited significantly more wing-fanning by workers and significantly less wax canopy construction. Hence an increase in rearing temperature of a few degrees increased colony longevity, colony size and queen production. However, individual longevity was not affected and so may have been buffered by changes in costly thermoregulatory behaviours. We conclude that eusocial insects may show complex phenotypic responses to projected temperature increases under climate change, including effects on productivity and reproduction at the colony level. Such effects should be considered when predicting the impact of climate change on the provision of essential pollination services

Proton damage comparison of an e2v technologies n-channel and p-channel CCD204

Comparisons have been made of the relative degradation of charge transfer efficiency in n-channel and p-channel CCDs subjected to proton irradiation. The comparison described in this paper was made using e2v technologies plc. CCD204 devices fabricated using the same mask set. The device performance was compared over a range of temperatures using the same experimental arrangement and technique to provide a like-for-like comparison. The parallel transfer using the p-channel CCD was then optimized using a trap pumping technique to identify the optimal operating conditions at 153 K

Development and Flight Results from the C3D2 Imager Payload on AlSat Nano

An experimental CubeSat camera system using 3 separate CMOS imagers was flown in 2014 on UKube-1. In response to an announcement opportunity in December 2014, we proposed an upgrade to our C3D imager payload, which was accepted to fly on AlSat Nano. Launched in September 2016 the system has been operational for over 1 year and has returned both images and housekeeping data, including detailed temperature and radiation dosimetry measurements. Through these in-orbit demonstrations on CubeSans, the image sensors and payload have attained TRL9, and these are now being used in other flight opportunities. In this paper we describe the C3D imager payload, which comprises 3 independent CMOS image sensors used in different camera systems; two wide field cameras are specifically optimised with one to observe the Earth from the 650 km orbit, and the other with its focus set to 40 cm to observe a deployable boom from the CubeSat. The experiment controller also contained thermometry and two RADFET dosimeters, one located on the payload, with the other deployed at a different point on the spacecraft. In this paper we will describe the experiment design and operational performance, and review the in-orbit data obtained during the operations covering over 17 months in-orbit, in addition to discussing lessons learned from the flight experience. We also discuss further developments of the payload concept which we are currently working on toward future flight opportunities

Effects of Cal Poly Construction Management Software Curriculum on Graduate Employment Choices

As technology continues to advance at an accelerated pace, the construction industry struggles to keep up with these rapid changes. Understanding and adopting new technologies, specifically software, are key to the future of the construction industry. Studies have shown that the slow adoption of software in the industry has more to do with a lack of training than the limitations of the software. New hires out of universities with experience and training in these software are the linchpin to adapting this industry to new technology. The Construction Management Department at Cal Poly is renowned for putting out new hires with the practical understanding and creative thinking necessary to thrive in this ever-changing industry. The hypothesis of this paper is that the software taught in the Cal Poly Construction Management Department affects which companies graduates choose to work for. Through a survey comprised of graduates from the Cal Poly Construction Management Department, this paper will attempt to discover a correlation between software used in graduate’s jobs and the software they learned in school, and analyze what gaps exist between Cal Poly and the industry in terms of valued software programs

Electron Multiplying Low-Voltage CCD With Increased Gain

Novel designs for the gain elements in electron multiplying (EM) CCDs have been implemented in a device manufactured in a low voltage CMOS process. Derived with help from TCAD simulations, the designs employ modified gate geometries in order to significantly increase the EM gain over traditional structures. Two new EM elements have been demonstrated with an order of magnitude higher gain than the typical rectangular gate designs, achieved over 100 amplifying stages and without an increase in the electric field. The principles presented in this work can be used in CMOS and CCD imagers employing electron multiplication in order to boost the gain and reduce undesirable effects such as clock-induced charge generation and gain ageing