Ambient Light Sensor Research Articles

47‐1: Ambipolar Gap‐type a‐Si‐TFT Circuit Applied for a Color Ambient Light Sensor

In this paper, we proposed ambient light sensor (ALS) and color temperature sensor (CTS) circuit integrated in the edge of LCD display panel. The designed circuit is based on the thin film transistor (TFT) technology, the photo TFT can produce high photo current under light for sensor realizing ambient light from 0~50000Lux. Also, CTS circuit are based on ALS circuit but covered with color filter. The result shows that CTS can discriminate different color temperature in ambient light. The biggest advantage of this sensor is that it is compatible with TFT process in manufacturing, and it is small in size and high in efficiency. It has the potential to replace photodiode sensors.

Smartphones as Smart Tools for Science and Engineering Laboratory: A Review

This article reviews a decade of research in transforming smartphones into smart measurement tools for science and engineering laboratories. High-precision sensors have been effectively utilized with specific mobile applications to measure physical parameters. Linear, rotational, and vibrational motions can be tracked and studied using built-in accelerometers, magnetometers, gyroscopes, proximity sensors, or ambient light sensors, depending on each experiment design. Water and sound waves were respectively captured for analysis by smartphone cameras and microphones. Various optics experiments were successfully demonstrated by replacing traditional lux meters with built-in ambient light sensors. These smartphone-based measurements have increasingly been incorporated into high school and university laboratories. Such modernized science and engineering experimentations also provide a ubiquitous learning environment during the pandemic period.

P‐17.5: Circuit Integration Scheme of Automotive High Resolution Touch Smart Module

High resolution and multi‐purpose are gradually becoming the trend of vehicle industry. BOE has developed a 42.2‐inch vehicle mounted high‐resolution touch smart module, which integrates multiple application scenario solutions such as partial privacy, camera under the screen, local dimming, ambient light sensor and haptic feedback. GOA architecture is adopted in the display circuit, 16 Source ICs supporting Touch function are cascaded, and two TCONs are jointly driven to achieve 10K resolution, 250 PPI Ultra high image quality and 1000000:1 high contrast. The whole module is composed of two independent panels. The two panels cooperate with each other to realize the function of partial privacy. The module integrates multiple functions and brings customers a safer, more comfortable and more intelligent driving experience.

Self-powered light dimming system using a magneto-mechano-electric generator with hardener-doped Pb(Mg1/3Nb2/3)O3–Pb(Zr,Ti)O3 single crystals

Pb(Mg1/3Nb2/3)O3–Pb(Zr,Ti)O3 (PMN-PZT) single crystals were doped with hardener Mn at variable concentrations to fabricate a high-output magneto-mechano-electric generator, which was then used to prepare a self-powered light dimming system with ambient light sensor.

Resonant waveguide vs Fabry-Perot cavity: A comparative study for CMOS spectral sensor technology

The ubiquitous use of versatile smart devices fuels a rapid growth in spectral sensor technology. Ambient Light Sensors (ALS), with 3–6 spectral channels in the visible and near-infrared are the most common version today. Their architecture comprises a pixel and a filter atop. While the compliance of the pixel to CMOS technology is built-in, the compliance of the filter in terms of materials and of process parallelism is not obvious. The process demand discards the pixel-scale variable-thickness Fabry-Perot solution, notably, and rather points to single-step nanophotonic structures whose pattern is specific to each ALS pixel/channel. In this study, we provide a performance comparison between two such candidate filters, the resonant waveguide (RWG) rejection filter, and the hybrid Fabry Perot (FP) band-pass filter. The evaluation is carried out in terms of spectral response, tunability, angular and polarization tolerance, and noise sensitivity, assessing the collective ability of an ALS array to retrieve spectral information. Through this analysis from the photon to the system, we pave a methodological frame for engineers and manufacturers facing a variety of application choices and sensing capabilities.

Attitude Determination in Space with Ambient Light Sensors using Machine Learning for Solar Cell Characterization

Organic Solar Cells In article number 2200537, Peter Müller-Buschbaum and co-workers present a new method for solar position triangulation using ambient light sensors, which determines the solar irradiance for evaluating the performance of novel material solar cells in space. The approach uses machine learning and can be applied to space or terrestrial solar cell applications.

P‐15.4: A newly Integrated Ambient Light sensor with full in‐cell structure

In this paper, we present a novel integrated light‐dependent sensor which can be used to detect the illuminance of the ambient light. Based on the low temperature polysilicon (LTPS) thin film transistor (TFT) process and photosensitivity of a‐Si, the sensor can realize 0‐10K lux of the monitor range and 0.5 lux/step. It saves more space for terminal devices which will also facilitates the full screen display.

A portable smartphone-based hemoglobin point-of-care testing platform for accurate anemia diagnostics

Anemia affects over 2 billion people worldwide, with the heaviest burden borne by women and children. At present, anemia is diagnosed by measuring hemoglobin (Hb) levels, which must be done in hospitals or commercial laboratories by skilled operators. In this work, we report a portable, affordable ($3), easy-to-operate (1 min) and accurate smartphone-based Hb analyzer (SHbA) that uses a drop of finger-pricked blood for anemia point-of-care test (POCT) applications. POCT of Hb was achieved using a smartphone ambient light sensor (ALS) to accurately measure the absorbance of colorimetric Hb biochemical analysis reagents in a microcuvette, as well as an Android-based application for results analysis. SHbA validation results agreed well with those reported by a hematology analyzer, and the SHbA has an anemia diagnosis sensitivity of 95.4% and specificity of 96.3% for venous blood (n = 360) and a sensitivity of 96.39% and specificity of 95.58% for fingertip blood (n = 475). In addition, SHbA exhibits excellent performance in the diagnosis and treatment guidance of anemia high-risk populations, including tumor chemotherapy patients (n = 424), pregnant women (n = 214) and thalassemia patients (n = 208). Importantly, volunteer self-testing results (n = 20) indicate that SHbA can be used for home-based anemia diagnosis and monitoring. SHbA has the advantages of high sensitivity and specificity while being cheap and easy to operate, making it widely applicable for the diagnosis and treatment of anemia, especially for high-risk patients in areas with poor medical resources.

Attitude Determination in Space with Ambient Light Sensors using Machine Learning for Solar Cell Characterization

Exploration of novel thin‐film solar cell technologies outreaches for their application in space. For extraterrestrial tests, irradiance conditions must be well determined to extract quantitative solar cell performances. Here, a new method for solar position determination is presented, based on parallelized ambient light sensor measurements is presented obtained from the sounding rocket experiment Organic and Hybrid Solar Cells In Space during the MAPHEUS‐8 mission. The solar position evolution is optimized using stochastic and gradient‐based methods in a Bayesian approach. Comparison with independent positioning estimates shows compelling agreement, lying mostly within 5° deviation. The inclusion of a simple Earth irradiation component mitigates a small systematic offset. Further, solution uncertainties are estimated with Monte‐Carlo Markov‐chain sampling. The point‐source irradiation model's accuracy can compete with that of a camera‐based trajectory. During equatorial Sun positions, the method's precision appears even higher––the 1σuncertainty of the derived solar position is as small as 3° for the effective angular deviation. This simple sensor array triangulation method being complementary to other attitude determination methods shows reasonable accuracies and allows implementation in systems of limited computational capabilities to determine the solar position or irradiance conditions for space or terrestrial solar cell applications.

LiLo: ADL Localization with Conventional Luminaries and Ambient Light Sensor

Indoor localization is a key factor for activities of daily living (ADLs)-related services. Many studies invest effort and money on high-cost infrastructure with modified devices. In this paper, an indoor localization system (LiLo) that utilizes ambient light sensor and orientation information on smartphones to recognize ADLs is proposed. Indoor ADLs are recognized by analyzing the data combination of visible light based localization, orientation and time. In the cold start period, LiLo estimates the location based on the computed luminance field map and the frequent orientation, validating the location result by the angle of arrival information. Then, LiLo produces the locations with a machine learning classifier. Compared with previous works, LiLo leaves out the laborious device configuration setup and data collection during the off-line phase. Another advantage is that LiLo utilizes a conventional luminaire and a standard smartphone, without extra infrastructure spreading in rooms. Therefore, every resident with a smartphone can benefit from this technology. An experimental study using data collected from smartphones shows that LiLo is able to achieve high localization accuracy at a low cost.

12‐2: High Accuracy In‐Cell Integrated Ambient Light and Color Temperature Sensor LCD

In this paper, we present a novel integrated light‐dependent sensor which can be used to detect the illuminance and color temperature of the ambient light. Based on the low temperature polysilimn (LTPS) thin film transistor (TFT) process and photosensitivity qf PIN photodiode, the sensor can realize 0–100K lux of the monitor range and an accuracy of 0.5 lux/step. Meanwhile, it can identify the color temperature from 2000 K to 8000 K with an accuracy of ± 250 K. The LCD panel with this optical sensor could adjust brightness and color temperature adaptively according to the ambient light. It saves more space for terminal product which will also facilitates the full screen display.

12‐1: Invited Paper: Through‐OLED Display Ambient Color Sensing

Integrating an ambient light sensor behind an active OLED display maximizes the useable display area. We discuss our solution that overcomes challenges in through‐display transmission and display‐to‐sensor optical crosstalk and enables ambient color adaptation and autobrightness display features.

A smartphone-based photometric and fluorescence sensing for accurate estimation of zinc ion in water

This paper demonstrates the development of a smartphone-based analytical system to determine zinc ion (Zn2+) concentration in water. The proposed system has been designed for simultaneous sensing in photometric and fluorescence mode on a single platform. Two inbuilt sensors of the phone, namely, the ambient light sensor (ALS) and the rear camera, have been utilized to develop the proposed sensing system. For photometric-based sensing, the ALS receives the transmitted modulated signal from the sample, while the rear camera records the fluorescence signal emitted from the sample at right angle to the direction of the excitation signal. The holder for the proposed sensing system has been fabricated in a 3D printer. A custom-designed android application has been developed to convert the proposed platform into a standalone tool. Using the designed sensor, Zn2+ ion concentration of field-collected water samples has been estimated successfully. Responses of the designed platform have been compared with the standard laboratory counterparts. The limit of detection and the percentage recovery of the proposed sensor are found to be 0.1 ppm and 103.10% respectively.

Cross-sectional association of light sensor-measured time outdoors with physical activity and gross motor competency among U.S. preschool-aged children: the 2012 NHANES National Youth Fitness Survey

BackgroundTime spent outdoors (outdoor time) has been suggested to be beneficial for physical activity (PA) and healthy development among preschool-aged children. The aim of this study was to quantify PA level and gross motor competency associated with light sensor-measured daily outdoor time in a representative sample of U.S. children aged 3 to 5 years.MethodsThe study sample included 301 participants (149 girls) aged 3 to 5 years from the 2012 U.S. National Health and Examination Survey National Youth Fitness Survey. ActiGraph GT3X+ accelerometers with a built-in ambient light sensor were used to measure PA (expressed in monitor-independent movement summary [MIMS]) and outdoor time. The Test of Gross Motor Development-Second Edition (TGMD-2) was used to assess gross motor skills. Multivariable linear regression models were fit to predict daily and gross motor scores by daily outdoor time.ResultsAverage daily outdoor time was 95 min (median of 84 min; interquartile range of 52 to 123 min). Means of daily outdoor time and daily MIMS were not significantly different between boys and girls. Among girls, every additional 10 min of daily outdoor time was associated with an additional 540 daily total MIMS (95% CI = 372, 708). Among boys, every additional 10 min of daily outdoor time was associated with an additional 296 daily total MIMS (95% CI = 131, 460). Every additional 10 min of daily outdoor time was associated with a 0.1-point (95% CI = 0.001, 0.130) higher object control standard score. Daily outdoor time was not associated with a locomotor standard score.ConclusionsIn a representative sample of U.S. preschool-aged children, daily outdoor time was positively associated with daily PA. The contribution of outdoor time to PA was greater among girls than boys, suggesting that providing outdoor opportunities is critical for promoting PA, particularly among girls.

Design of low cost IoT enabled embedded control system for covid free smart home

In the era of automation, the Internet of Things (IoT) has come up as a solution and innovation for many applications to improve the basic facilities required in the day-to-day routine. IoT, itself is the interconnectivity of different physical devices with the help of wireless networks e.g., Bluetooth, Wi-Fi without human intervention. The low-cost embedded control unit for Covid free Smart Home is based on the idea of home automation by keeping the current situation of the Covid pandemic in mind. Irradiation of Ultraviolet C (UVC) spectrum is used to sanitize household goods, where convectional sanitization process is not suitable. Simple home automation means controlling or monitoring different electronic/electrical home appliances, devices, and other such things with smartphones or by doing sensor-based operations. All the required devices are connected with one embedded control unit which is managed through a mobile app. This functionality can be accessed either by manually operating a mobile app or with voice assistants e.g., Alexa or Google Assistant, etc. The basic point of communication among devices is based on real-time sensor inputs, which trigger the devices for action and react as per requirements. Ambient light sensors are used to control the on/off the functionality of lights based on the intensity of light present naturally. In this scenario, lights will be switched off in day mode and switched on in night mode. Advancement in wireless technologies enables the researchers to apply various modes of communications among the sensors, gateway, and applications. Bluetooth, Wireless sensor network (WSN), Wi-Fi, Global system for mobile communication (GSM) are a few of them, which are being used either in sensing nodes or in communication gateway to make home automation free of the wired network.

Analysis and Experiment of Wireless Optical Communications in Applications Dedicated to Mobile Devices with Applicability in the Field of Road and Pedestrian Safety.

Current developments and the need for high-performance devices that provide safe and reliable communications present a future perspective by using visible light as an alternative solution that can substantially improve road and pedestrian safety. The daily use of smartphones is imperative; thus one can build on this premise a system dedicated to the aforementioned problem. However, the problem of the visible light communication channel (VLC) is highly dynamic and becomes extremely unpredictable in terms of exposure to noise sources. Developing applications dedicated to direct communications with infrastructure and vehicles using portable devices is becoming a challenge and at the same time a necessary solution. The article proposes the shaping of an emission–reception architecture dedicated to adaptive fuse light communications using OCC (optical camera communication) but also standard VLC communications using ambient light sensors via an Android application. This approach aims to provide a first step in shaping information-sharing applications using VLC communications. As far as we know, this approach has not been implemented in external VLC systems. The performance of the architecture and the application was demonstrated by practical tests that confirmed the capacity of the technology even if we are in the first stage.

The role of π-donors/acceptors in molecular rotors towards development of ambient blue light sensors - A density functional theory study

A series of molecular rotors based on cyclopentane are taken into consideration to explore the influence of different π-donors/acceptors substitution on their efficiency in blue light detection. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods are used to investigate the electronic excitations and photophysical properties of the designed rotors. The influence of mono- and di-substitution on photoisomerization and thermal helix inversion reaction barriers are studied. We find that the di-substitution of a π-donor and a π-acceptor have improved the parent rotor's optical properties towards a longer wavelength. Especially, the rotor R2,3(NH2, CHO) exhibits the light response range in the blue region (∼408 nm) due to its narrow bandgap (4.94 eV). Our results show that although the substitution of π-donors/acceptors improved the photophysical properties, it has no significant influence on the overall rate-determining thermal helix inversion step barriers. This theoretical work provides new insight into the role of π-donors/acceptors substitution in designing blue light sensors.

ZnO and ZnO/Co3O4 Nanorods for Enhanced Photovoltaic and Photosensors Applications

In this present work, we plan for the first time an all-oxide solar cell and ambient light sensors constructed onto n-type semiconductor zinc oxide along with p-type material having extrinsic type of semiconductor Co3O4 nanowires. The perpendicular ZnO nanorods are dense and are working like scattering layer used for the visible light, even though Co3O4 nano material acting as a visible-light absorber directly. Characterization by SEM, AFM, TEM, XRD, EDS, Optical transmittance, J–V curve. The p-n junction based on metal oxides can operate both such as a photovoltaic (PV) device and a visible light photodetector. The photovoltaic parameters measured beneath simulated sunlight, demonstrating for the first time a PV effect in longitudinal nanowire junctions with decent fill factor (FF, 45%). Furthermore, the heterojunction has also shown an excellent, stable, highly reproducible material, having very fast activity designed for the exposure of visible light. Functional, or effective as possible of the device is essential to strongly improve its functionalities of material. The proposed oxide nanowire p-n junction provides advancement in the field of PV and optoelectronic devices by using inexpensive, stable, and earth-abundant metal oxides.

Multifunctional 3D-printed platform integrated with a smartphone ambient light sensor for halocarbon contaminants monitoring

3D-printed platforms integrated with smartphone light sensors have become a powerful tool for the development of frugal and facile biosensing systems. Herein, we report a 3D-printed platform for multimodal analysis (3D-PMA) based on a smartphone ambient light sensor (ALS). The proposed approach was first validated using a microtiter plate reader, and then its application potential was demonstrated by measuring halohydrin dehalogenase activities employing three different sample modes, viz . using enzyme-linked immunosorbent assay (ELISA) plate strips, cuvettes, and the glass fiber membrane as sample containers. For real-sample analysis, 1,3-dichloro-2-propanol (1,3-DCP), a toxic halogenated compound, was successfully detected in spiked river water samples with recoveries in the range of 101.95–109.70%. After demonstrating the suitability for liquid-phase assays, the 3D-PMA was also optimized for 1,3-DCP detection using a glass fiber membrane. The detection could be done using a 10 μ L reaction system with an assay time of 2 min. The assay showed two linear ranges. The calibration equation of Y = 81.687x + 140.060 was obtained from the lower part of the calibration curve and was used to calculate the detection limit of the system. Under optimized conditions, a detection limit of 80 μ M was achieved for 1,3-DCP. The small size of the device endows it with great promise for use as a benchtop and an on-demand detection system. The proposed low-cost and portable system has great potential for the (bio) sensing of different biological and environmental samples where biocomponent-analyte interaction leads to a color change of the reaction system, indicating its applicability in resource-constrained settings. • A smartphone assisted portable system was developed for environmental contaminants monitoring. • 3D-printed platform demonstrated potential utility for multimodal analysis. • Smartphone Ambient Light Sensor as a potential transducer for halocarbon detection.

An energy autonomous and battery-free measurement system for ambient light power with time domain readout

Internet of Things (IoT) provides more and more adequate infrastructures for many applications and advanced services. This context promotes the ability to satisfy the growing demand for innovative measuring systems, increasingly popular with intelligent nodes, totally wireless, easy to install that require the least possible maintenance. This paper aims to contribute to the state-of-the-art with an energy-autonomous and battery-free measurement platform designed to measure the ambient light power when its level exceeds the Limit of Detection (LoD) threshold. The proposed system consists of a single photovoltaic transducer to harvest energy and simultaneously detect ambient light. The result is a wireless measurement platform, which requires neither a battery nor a specific ambient light sensor, with the immediate advantage of achieving greater energy efficiency and using fewer components. The device implements off-the-shelf components on a printed circuit board (PCB) with a tag size of 2 × 2cm2. Data communication is via Bluetooth Low Energy (BLE) and, the device can acquire energy and detect ambient light from 250lux.