VISION EXPERIMENT ON PERCEPTION OF CORRELATED COLOUR TEMPERATURE

2018 ◽  
Author(s):  
Youngshin Kwak ◽  
Yoshi Ohno ◽  
Hyeyoung Ha
Keyword(s):  
Colour Temperature ◽  
Vision Experiment

Analysis of Characteristics of Halogen and LED Automobile Lamps

2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Power Consumption ◽  
Flip Chip ◽  
Weather Conditions ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Colour Temperature ◽  
Study Results ◽  
Calculation Results ◽  
Mandatory Rules ◽  
Halogen Lamps

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.

The Influence Of The Led Luminaires Electrical Parameters On Their Correlated Colour Temperature During Operation Mode

2020 ◽  
pp. 89-96
Author(s):  
Sergei S. Kapitonov ◽  
Alexei S. Vinokurov ◽  
Sergei V. Prytkov ◽  
Sergei Yu. Grigorovich ◽  
Anastasia V. Kapitonova ◽  
...  
Keyword(s):  
Operation Mode ◽  
Light Sources ◽  
Electrical Parameters ◽  
Colour Temperature ◽  
Radiation Spectra ◽  
Service Period ◽  
Close Proximity ◽  
Definition Of ◽  
Comprehensive Study

The article describes the results of comprehensive study aiming at increase of quality of LED luminaires and definition of the nature of changes in their correlated colour temperature (CCT) in the course of operation. Dependences of CCT of LED luminaires with remote and close location of phosphor for 10 thousand hours of operation in different electric modes were obtained; the results of comparison between the initial and final radiation spectra of the luminaires are presented; using mathematical statistics methods, variation of luminaire CCT over the service period claimed by the manufacturer is forecast; the least favourable electric operation modes with the highest CCT variation observed are defined. The obtained results have confirmed availability of the problem of variation of CCT of LED luminaires during their operation. Possible way of its resolution is application of more qualitative and therefore expensive LEDs with close proximity of phosphor or LEDs with remote phosphor. The article may be interesting both for manufacturers and consumers of LED light sources and lighting devices using them.

scholarly journals The optimum colour temperature for illumination of Japanese-style gardens in summer and winter

2017 ◽  
Vol 51 (1) ◽  
pp. 82-98 ◽  
Author(s):  
D Jia ◽  
T Misawa ◽  
M Takamatsu ◽  
S Hirobayashi
Keyword(s):  
Light Source ◽  
Image Recognition ◽  
Statistical Significance ◽  
Semantic Differential ◽  
Cultural Value ◽  
Evaluation Methodology ◽  
Colour Temperature ◽  
Differential Technique ◽  
Vegetation Water ◽  
Semantic Differential Technique

Japanese-style gardens offer a wealth of spiritual and cultural value. In this study, we attempt to determine the optimum colour temperature for lighting Japanese-style gardens at night. We analyse the influence of a change in light source colour temperature on image recognition using digitalization and quantification with the semantic differential technique. In addition, we propose a new evaluation methodology for the semantic differential technique and examine the statistical significance of the results. We find that in summer, impressions of the optimum colour temperature for each element (vegetation, water, stone and structure) differ significantly, but in winter, because of the effects of snow, differences in the impression of each colour temperature are not as distinct. Moreover, the colour of the natural environment or overall season affects peoples’ preferred light source colour temperature.

scholarly journals Colour Temperature Tuning to Improve Efficacy of White Light

2016 ◽  
Vol 24 ◽  
pp. 1186-1193 ◽  
Author(s):  
Saijo Prathap ◽  
Sonia Sunny ◽  
Aju S. Nair
Keyword(s):  
White Light ◽  
Colour Temperature ◽  
Temperature Tuning

Research Note: LED chip-on-board packaging technology for strict colour tolerance

2017 ◽  
Vol 49 (8) ◽  
pp. 1052-1057
Author(s):  
J Zhang ◽  
P Ge ◽  
Z Zhou ◽  
D Liu ◽  
H Wang ◽  
...  
Keyword(s):  
Research Note ◽  
Luminous Efficacy ◽  
Packaging Technology ◽  
Colour Temperature ◽  
Colour Rendering ◽  
Method Show

In the field of LED packaging, people usually pay more attention to colour temperature, luminous efficacy and colour rendering than colour tolerance. This paper focuses on how to meet strict colour tolerances in the process of chip-on-board packaging. The McAdam ellipses are used to explain the meaning of colour tolerance. A method based on adjusting the amount of phosphor glue and the proportions of different phosphors it contains is described. Measurements on samples packaged according to this method show that it makes it possible to meet strict colour tolerance requirements.

scholarly journals Physico-Chemical Analysis of Culture Pond for Induced Pearl Production in Lamellidens marginalis

2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Vijiyata Singh Rathour ◽  
Vijay Kumar Yadav
Keyword(s):  
Chemical Analysis ◽  
Pond Water ◽  
Botanical Garden ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Chemical Parameters ◽  
Colour Temperature ◽  
Physico Chemical ◽  
Calcium Magnesium ◽  
Healthy Growth

Bioassay experiments were carried out in order to evaluate values of physico-chemical parameters of the cultured pond water for induced pearl production in Lamellidens marginalis. The pond was located at Botanical garden of Bipin Bihari P.G. College, Jhansi. The parameters included for this study were Colour, Temperature, Transparency, pH, Free CO2 , DO, Total Hardness, Calcium, Magnesium and Total Alkalinity of cultured pond water and to maintain them for the healthy growth of mussels during the whole culture period for obtaining designer pearls.

VISUAL EFFECTS OF OBJECTS UNDER METAMERISM WITH MULTI-SPECTRAL LIGHT SOURCE

2021 ◽  
Author(s):  
Y.M. Li ◽  
H. Fan ◽  
C.H. Lin ◽  
J.U. Chong ◽  
T.X. Lee
Keyword(s):  
Light Source ◽  
Positive Relationship ◽  
Target Object ◽  
Visual Effects ◽  
Colour Temperature ◽  
Lighting Conditions ◽  
The Future ◽  
Convenience Sampling ◽  
Colour Rendering

This study attempts to simulate the metamerism colour, and the guava was used as the target object. We design four sets of metamers with a correlated colour temperature of 4000K and an illuminance of 750lux. The light source was simulated in the LED cube. The subjects with convenience sampling observed the visual effects, including look delicious, colourful, and colour rendering of guava under metamerism, then analysed its relationship with CRI and CQS. The results showed that colour rendering and visual effects are not a positive relationship, and the effect of CQS is closer to the visual effects of the subjects. The results of this study can be used as a reference for light source lighting designers as a basis for improving lighting conditions. In the future, we can collect databases for the different objects with an optimized multi-spectral light source.

scholarly journals Light Emitting Diodes (LED) for Aqueous Light Bleaching of Paper

2019 ◽  
Vol 40 (2) ◽  
pp. 69-95
Author(s):  
Benjamin Kirschner ◽  
Irene Brückle ◽  
Ute Henniges
Keyword(s):  
Carbonyl Group ◽  
High Performance ◽  
Molar Mass ◽  
Light Exposure ◽  
Light Sources ◽  
Light Emitting ◽  
Colour Temperature ◽  
Negative Effect ◽  
Hid Lamps ◽  
Reference Samples

Abstract High performance daylight LED lamps are compared with HID lamps for light bleaching of paper. The LED can be placed in closer proximity to the object than the HID lamps, causing a significantly increased, uniform light exposure. Two commercial LED systems with 4000 K and 6500 K colour temperature were installed in a convertible test device with a polypropylene tray in default exposure distance of 10 cm and 20 cm. A HID lamp in 60 cm and 120 cm distance served as a reference. Samples of two naturally aged rag papers were bleached with both LED systems and with the HID while immersed in water. All three light sources increased brightness (CIELAB L*), though the LEDs with 4000 K colour temperature were most effective. They had no negative effect on the molar mass and the cellulose carbonyl group content while LEDs with 6500 K colour temperature caused molar mass decrease and carbonyl group increase. LEDs of a 4000 K or similar colour temperature are a promising option for improved light bleaching of paper, reducing the treatment and aqueous exposure time and eliminating UV radiation.

Sign in / Sign up

Export Citation Format

Share Document