scholarly journals What Color Does the Consumer See? Perceived Color Differences in Plastic Products in an LED-Lit Environment

2019 ◽  
Vol 11 (21) ◽  
pp. 5985 ◽  
Author(s):  
Xiao Dou ◽  
Chih-Fu Wu ◽  
Kai-Chieh Lin ◽  
Jeih-Jang Liou
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Visual Sensitivity ◽  
Color Temperature ◽  
Light Sources ◽  
Color Differences ◽  
Market Opportunities ◽  
Actual Color ◽  
Human Eyes ◽  
Perceived Color ◽  
Plastic Products

To attract customers and increase market opportunities, retailers frequently use lighting to highlight the color of their products. However, differences between perceived and actual color, triggered by display lighting, can motivate buyers to discard products after purchase. Few studies have been reported on differences in perceived color, caused by LEDs. This study focuses on two correlated color temperatures (2800 K, 4000 K) and illuminance levels (500 lx, 1500 lx) to create four LED-lit environments, and measures the differences in the color perceived by 20 observers on acrylonitrile–butadiene–styrene (ABS) plastics, with different surfaces, under these four environments. The results reveal that correlated color temperature results in larger perceived differences in color than illuminance, and the effects of LED light sources on green and yellow ABS plastic products are more obvious than their effects on red and blue products. One possible reason for this can be attributed to the visual sensitivity effect of human eyes. The results of this study can serve as a reference for designers fabricating ABS plastic products for practical lighting applications, and improving the role of LED lighting in sustainable development.

scholarly journals An Efficient Method for LED Light Sources Characterization

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1089 ◽  
Author(s):  
Sara Raggiunto ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Piergiovanni Ceregioli ◽  
Massimo Gattari ◽  
...  
Keyword(s):  
Efficient Method ◽  
Least Squares Method ◽  
Color Temperature ◽  
Experimental Setup ◽  
Light Sources ◽  
Careful Study ◽  
Source Characterization ◽  
Led Light ◽  
Lighting Systems ◽  
Led Drivers

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs’ power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED’s response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions.

Optimization Algorithm of Correlated Color Temperature for LED Light Sources by Dichotomy

2009 ◽  
Vol 29 (10) ◽  
pp. 2791-2794 ◽  
Author(s):  
林岳 Lin Yue ◽  
叶烈武 Ye Liewu ◽  
刘文杰 Liu Wenjie ◽  
吕毅军 Lü Yijun
Keyword(s):  
Optimization Algorithm ◽  
Color Temperature ◽  
Light Sources ◽  
Led Light

scholarly journals Impact of different standard lighting sources on red jadeite and color quality grading

2019 ◽  
Vol 23 (4) ◽  
pp. 371-378
Author(s):  
Xin Pan ◽  
Ying Guo ◽  
Ziyuan Liu ◽  
Zikai Zhang ◽  
Yuxiang Shi
Keyword(s):  
Light Source ◽  
Color Space ◽  
Sample Surface ◽  
Color Temperature ◽  
Integrating Sphere ◽  
Light Sources ◽  
Light Spectrum ◽  
Fisher Discriminant Analysis ◽  
Fisher Discriminant ◽  
Quality Grading

The purpose of this paper is to investigate the standard light source for grading and displaying the color of red jadeite and to classify the color. With Raman spectrometer, ultraviolet-visible spectrophotometer and X-ray fluorescence spectrometer, the results show that, the Fe 3+ is the main chromogenic mineral of red jadeite, which negatively correlates with the tonal angle, while the color of red jadeite has a positive correlation with the hematite content. The color of 120 red jadeite samples was examined by collecting the reflective signaled from the sample surface using an integrating sphere with the portable X-Rite SP62 spectrophotometer based on CIE 1976 L*a*b* uniform color space. The color parameters of jadeite samples under D65, A and CWF standard light sources were analyzed. The light spectrum of D65 light source is continuous, relatively smoothed with high color temperature, which makes the sample color close to that under the natural light and can be used as the best evaluation light source. A light source contributes to improve the red tone of jadeite, which is the best light source for commercial display of red jadeite. CWF light source can be used as the auxiliary lighting for color evaluation. The color of red jadeite is divided into five levels from best to worst using K-Means cluster analysis and Fisher discriminant analysis under D65 light source: Fancy Vivid, Fancy Deep, Fancy Intense, Fancy dark and Fancy.

Influence of the Parameters of Light Source on Observers’ Visual Performance

2015 ◽  
Vol 731 ◽  
pp. 124-128
Author(s):  
Min Huang ◽  
Zhen Zheng ◽  
Huan Jiang ◽  
Hao Xue Liu
Keyword(s):  
Light Source ◽  
Reading Rate ◽  
Mental Capacity ◽  
Visual Performance ◽  
Color Temperature ◽  
Light Sources ◽  
Accuracy Index ◽  
The Given ◽  
Dose Experiment

In order to investigate the influence of the light source with different illuminance and color temperature on the observers’ visual performance, five kinds of light sources were selected, named LED1, LED2, LED3, LED4 and Fluorescent, which have different illuminance or color temperature. 3 series of visual experiments, such as the ‘find out’ experiment, compared experiment, dose experiment were designed.13 observers were organized to carry out the experiment in the given time in turn. The reading rate, accuracy , index of mental capacity (IMC) and visual comfortable level score were analyzed, the results indicated that the light source with the lower color temperature and medium illuminance has the best visual performance and comfortable visual feel.

scholarly journals The Influence of LED Lighting in School Recreation Areas on Visual Acuity and Psycho-Emotional State of First Graders in the Dynamics of a Schoolyear

2019 ◽  
pp. 25-30
Author(s):  
NA Skoblina ◽  
OYu Milushkina ◽  
AM Kurgansky ◽  
SV Markelova ◽  
AP Tsameryan ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Emotional State ◽  
First Graders ◽  
Color Temperature ◽  
Light Sources ◽  
Color Test ◽  
Led Lighting ◽  
Light Load ◽  
Recreation Areas ◽  
The Impact

Object: The wide spread of gadgets among modern schoolchildren and their intensive use during breaks in school corridors and recreation areas indicates the necessity of improving illumination in school recreation areas to secure conditions suitable for intensive visual work. Thanks to their technical characteristics, durability and affordable price, LED light sources can ensure the implementation of this task. The objective of the study was to assess the impact of LED lighting of school corridors, halls and recreational facilities on visual acuity and psycho-emotional state of first graders in the course of a schoolyear. Materials and methods: In the corridors and recreation areas of the Dolgoprudninskaya Gymnasium (Moscow Region), fluorescent lamps were replaced by PrLUX-AU-36 LED lamps with Epistar LEDs, opal diffuser, 3600Lm luminous flux, and the color temperature of 4000K. Measurements of artificial lighting were taken before and after installing LED lamps using a TKA PKM 43 light meter. We conducted a study of visual acuity among 67 first graders (aged 7-8) in the annual dynamics from September to May using the Sivtsev-Golovin table placed in the Rota apparatus. Testing was conducted by a highly qualified ophthalmologist. The psycho-emotional state was assessed using the Luscher color test. Results: We observed a significant increase in visual acuity in children over the specified period indicating the absence of negative effects of LED lighting on the organ of vision. The results of the Lusher test proved the absence of negative dynamics, thus demonstrating null adverse health effects of LED lighting in the primary schoolchildren. The studies confirmed that the influence of that light load on vision and its negative non-visual effects were only potential.

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