The paper presents both chrominance uniformity and color temperature compensation for RGB LED lighting illumination. A self-developed color optical sensing module and an integrating sphere were used ...to measure the color characteristics of LED pixels. Firstly, the transfer coefficients for each color measurement were calibrated. A calibrated sensing module was applied to inspect the color characteristics of 3 in 1 color LED modules. With the required target color chrominance or color temperature, the compensated RGB lighting ratio can be derived according to the mixed light formula associated with original RGB measurement. The experimental results from the 4×4 LEDs show that the deviation of white chrominance by using a 3 in 1 LED module is about 0.1001 before compensation, but the average color deviation is reduced to 0.002 and the average color temperature deviation is less than 71K after compensation by using the proposed method.
The paper presents an automated color inspection and compensation solutions for color LED modules which are main components of a color LED display panel. Initially, a self-developed color optical ...sensing module and a colorimeter were used to measure the colors of LED pixels. After the color matching functions from the collected data was corrected by least-squares approximation method, the calibrated measured sensing module was applied to inspect the color characteristics of LED modules. And the chrominance and luminance data are well analyzed to perform a white light chrominance correction and luminance uniformity compensation for LED display modules. Some 2R1G1B LED modules (16×16 LEDs) from a local industry were verified in this study. The experimental results from the central 8×8 LEDs show that the average color difference of a target D65 white light with a chrominance of (0.1978, 0.4683) by using a 2R1G1B LED module is about 0.027006 before compensation, but the average color difference can be reduced to 0.003474 after it was compensated by using the proposed method. Meanwhile, the luminance difference was also reduced to less than 3.541%.
This paper presents the use of RGB color sensor to measure amount of Curcuminoids in Turmeric (Curcuma longa Linn.) and Zedoary (Curcuma Zedoarie Rose.). The measured data of fresh Turmeric sample ...from the color sensor in HSL (hue saturation lightness) was then compared with amount of Curcuminoids obtained by conventional method of UV-spectrophotometry. The mathematical relationship between these two kinds of data was then generated. The result of the experiment revealed that the amount of Curcuminoids increased when the Turmeric turned orangish yellow and decreased when the Turmeric turned greenish yellow. The analysis result from the color sensor implemented in this research and the conventional UV-spectrophotometry are not significantly different with high reliability 95% (p>0.05) in statistics.
A white cane is a typical support instrument for the visually impaired. They use a white cane for the detection of obstacles while walking. So, the area where they have a mental map, they can walk ...using white cane without help of others. However, they cannot walk independently in the unknown area, even if they use a white cane. Because, a white cane is a detecting device for obstacles and not a navigation device for there correcting route. Now, we are developing the navigation system for the visually impaired which uses indoor space. In Japan, sometimes colored guide lines to the destination are used for a normal person. These lines are attached on the floor, we can reach the destination, if we walk along one of these line. In our system, a developed new white cane senses one colored guide line, and makes notice to a user by vibration. This system recognizes the color of the line stuck on the floor by the optical sensor attached in the white cane. And in order to guide still more smoothly, infrared beacons (optical beacon), which can perform voice guidance, are also used
The ldquoGold standardrdquo for testing blood glucose in Colorimeters is the measurement of glucose in a plasma sample obtained from a vein. This method involves a chemical reaction activated by an ...enzyme called Glucose Oxidase. Most of the Colorimeters used for the Glucose measurement in Clinical laboratories perform well in the 100-400 mg/dL range of blood glucose. Due to the requirement of highly monochromatic source and photo detector, an error of 5 to 20% is common in these Colorimeters. This paper aims to mitigate the error in measurement by modernizing the plasma glucose testing equipment i.e., Colorimeter with White Source and RGB Color Sensor through Color measurement technique for better clinical diagnosis. As presumed, experimental results show that this modified Colorimeter can perform well with better accuracy even above the Glucose concentration of 400 mg/dL.
The three main tasks of modern lighting design are to support the visual performance, satisfy color emotion (color quality), and promote positive non-visual outcomes. In view of large-scale ...applications, the use of simple and inexpensive RGB color sensors to monitor related visual and non-visual illumination parameters seems to be of great promise for the future development of human-centered lighting control systems. In this context, the present work proposes a new methodology to assess the circadian effectiveness of the prevalent lighting conditions for daylight and artificial light sources in terms of the physiologically relevant circadian stimulus (CS) metric using such color sensors. In the case of daylight, the raw sensor readouts were processed in such a way that the CIE daylight model can be applied as an intermediate step to estimate its spectral composition, from which CS can eventually be calculated straightforwardly. Maximal CS prediction errors of less than 0.0025 were observed when tested on real data. For artificial light sources, on the other hand, the CS approximation method of Truong et al. was applied to estimate its circadian effectiveness from the sensor readouts. In this case, a maximal CS prediction error of 0.028 must be reported, which is considerably larger compared to daylight, but still in an acceptable range for typical indoor lighting applications. The use of RGB color sensors is thus shown to be suitable for estimating the circadian effectiveness of both types of illumination with sufficient accuracy for practical applications.
An automated system for measuring plant leaf colour, as an indicator of plant health status, has been developed for plantlets growing in a modified micropropagation system. Using a custom built ...robotic arm, sensors located on a pan and tilt system at the end of the arm monitor plant growth and the ambient growing environment. Sensors include a compact colour zoom camera, RGB (red, green and blue) colour sensors, and environmental sensors. Leaf colour sensors provide information, in a non-destructive manner, on the health status of tissue by comparing the sensor outputs to pre-determined optimum values. These low cost colour sensors can be incorporated into a continuous automated system for monitoring leaf colour of growing plants. Subtle colour changes can be an early indication of stress from less than optimum nutrient concentrations. When combined with automated image sensing for growth analysis, and environmental sensing (RH, CO 2 and temperature) in a controlled environment, optimised rapid growth with minimal human input can be achieved using a modified micropropagation system. In this paper we detail the calibration technique for a RGB sensor and compare it with a high end spectrophotometer.
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