Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ130000506
C. Brañas, F. Azcondo, R. Casanueva
This paper presents a phase-controlled two-phase resonant converter as a highly flexible platform for evaluating different modulation patterns of the operating current for high-brightness light emitting diode (LED) lamps. This control flexibility arises from the wide bandwidth of the resonant converter ensuring an operation free of instabilities and flicker effects. The control parameter is the phase-shift, Ψ, between the drive signals of each inverter leg. The proposed driver is designed as a current source able to set different patterns of amplitude modulated (AM) output current to implement light dimming controls. A 120 W prototype has been built to validate the design proposal.
{"title":"Modulation Scheme for Dimming High-Brightness LED Lamps","authors":"C. Brañas, F. Azcondo, R. Casanueva","doi":"10.2150/JLVE.IEIJ130000506","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000506","url":null,"abstract":"This paper presents a phase-controlled two-phase resonant converter as a highly flexible platform for evaluating different modulation patterns of the operating current for high-brightness light emitting diode (LED) lamps. This control flexibility arises from the wide bandwidth of the resonant converter ensuring an operation free of instabilities and flicker effects. The control parameter is the phase-shift, Ψ, between the drive signals of each inverter leg. The proposed driver is designed as a current source able to set different patterns of amplitude modulated (AM) output current to implement light dimming controls. A 120 W prototype has been built to validate the design proposal.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130836138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ120000474
A. Dugar
This paper aims to identify end-user requirements that help improve the effectiveness of lighting control systems. The crucial question posed is, what is the nature of interface designs sought by end-users for maximising interaction with lighting control systems? Literatures from the most influential studies on interactive systems are reviewed to list end-user requirements in the order of three stages of human interface with technology: Recognition, Exploration and Reliance. Results of two interactive studies with end-users are then reviewed to validate this list of requirements. The objective is to provide perspectives and themes for analysis, as well as conceptual guidance for designing lighting control interfaces that are easier to understand and use for end-users.
{"title":"Lighting Control Systems and End-users—Establishing an Interactive Relationship","authors":"A. Dugar","doi":"10.2150/JLVE.IEIJ120000474","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ120000474","url":null,"abstract":"This paper aims to identify end-user requirements that help improve the effectiveness of lighting control systems. The crucial question posed is, what is the nature of interface designs sought by end-users for maximising interaction with lighting control systems? Literatures from the most influential studies on interactive systems are reviewed to list end-user requirements in the order of three stages of human interface with technology: Recognition, Exploration and Reliance. Results of two interactive studies with end-users are then reviewed to validate this list of requirements. The objective is to provide perspectives and themes for analysis, as well as conceptual guidance for designing lighting control interfaces that are easier to understand and use for end-users.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131057142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ130000499
Yoshihisa Ikeda, Y. Takeda, Ueno Misaki, Y. Matsuba, Atsushi Heike, Yoji Kawasaki, Kinoshita Junichi
A new type of 4000–5000 lm-class white lamp system using high-power blue laser diodes and phosphors has been developed for high-luminance lighting applications. Using fibre-optics, the lamps can be arranged separately from a light engine containing the blue laser diodes. One of the new lamp systems achieved much higher luminance of 140 Mcd/m2 than the conventional white LEDs. Their lighting quality and safety categorization have been discussed based on speckle contrast as an index of coherence. Speckle contrast values less than 2% as low as the LEDs have been obtained, implying that these lamps are considered to be incoherent as well as the conventional white LEDs. Multiple scattering processes in the lamp structure including the phosphor layer are found to be indispensable for reducing speckle contrast completely, adding to multi-longitudinal mode operation of the blue laser diodes.
{"title":"Incoherentized High-brightness White Light Generated Using Blue Laser Diodes and Phosphors—Effect of Multiple Scattering—","authors":"Yoshihisa Ikeda, Y. Takeda, Ueno Misaki, Y. Matsuba, Atsushi Heike, Yoji Kawasaki, Kinoshita Junichi","doi":"10.2150/JLVE.IEIJ130000499","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000499","url":null,"abstract":"A new type of 4000–5000 lm-class white lamp system using high-power blue laser diodes and phosphors has been developed for high-luminance lighting applications. Using fibre-optics, the lamps can be arranged separately from a light engine containing the blue laser diodes. One of the new lamp systems achieved much higher luminance of 140 Mcd/m2 than the conventional white LEDs. Their lighting quality and safety categorization have been discussed based on speckle contrast as an index of coherence. Speckle contrast values less than 2% as low as the LEDs have been obtained, implying that these lamps are considered to be incoherent as well as the conventional white LEDs. Multiple scattering processes in the lamp structure including the phosphor layer are found to be indispensable for reducing speckle contrast completely, adding to multi-longitudinal mode operation of the blue laser diodes.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126378440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ120000489
Yoshie Imai, R. Saito, T. Horiuchi, S. Tominaga
{"title":"Color Image Correction of Art Paintings Based on Artists' Color Features and Illuminant Conversion","authors":"Yoshie Imai, R. Saito, T. Horiuchi, S. Tominaga","doi":"10.2150/JLVE.IEIJ120000489","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ120000489","url":null,"abstract":"","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130914439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ130000496
Haojun Zhang, Jie Liu, Qiuyi Han, Shanduan Zhang
The radiant efficiency of low pressure mercury (LPM) discharge lamps with outer diameter of 19 mm (T6) was measured for various parameters: cold spot temperature, discharge current, and buffer gas pressure. The buffer gas was neon (75%) and argon (25%) with total pressure 133–1333 Pa. The lamps were operated with cold spot temperatures 20–80°C and discharge current 0.8–2.0 A. The electric field, input power, 254 nm radiant power and efficiency, spectra of Hg lines 254–579 nm and rare gas lines 738–850 nm in positive column were measured. It was shown that under discharge condition of cold spot temperature 45°C and current 1.6 A, the 254 nm UV radiant efficiency had a maximum of above 40% for buffer gas pressure 133–267 Pa. The optimal mercury vapor pressure was approximate 1.2 Pa, corresponding to the cold spot temperature around 45°C. The sum of radiant energy percentage of other mercury lines and rare gas lines was less than 10%, which proved that high output LPM lamps can be good choice of UV radiation source.
{"title":"254 nm Radiant Efficiency and Spectral Lines of High Output T6 Low Pressure Mercury Discharge Lamps with Neon–Argon Buffer Gases","authors":"Haojun Zhang, Jie Liu, Qiuyi Han, Shanduan Zhang","doi":"10.2150/JLVE.IEIJ130000496","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000496","url":null,"abstract":"The radiant efficiency of low pressure mercury (LPM) discharge lamps with outer diameter of 19 mm (T6) was measured for various parameters: cold spot temperature, discharge current, and buffer gas pressure. The buffer gas was neon (75%) and argon (25%) with total pressure 133–1333 Pa. The lamps were operated with cold spot temperatures 20–80°C and discharge current 0.8–2.0 A. The electric field, input power, 254 nm radiant power and efficiency, spectra of Hg lines 254–579 nm and rare gas lines 738–850 nm in positive column were measured. It was shown that under discharge condition of cold spot temperature 45°C and current 1.6 A, the 254 nm UV radiant efficiency had a maximum of above 40% for buffer gas pressure 133–267 Pa. The optimal mercury vapor pressure was approximate 1.2 Pa, corresponding to the cold spot temperature around 45°C. The sum of radiant energy percentage of other mercury lines and rare gas lines was less than 10%, which proved that high output LPM lamps can be good choice of UV radiation source.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128009255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-12-01DOI: 10.2150/JLVE.IEIJ130000500
Katsumi Sato, S. Ukegawa, Katsumasa Nakai
{"title":"Technological Strategy of Solid State Lighting","authors":"Katsumi Sato, S. Ukegawa, Katsumasa Nakai","doi":"10.2150/JLVE.IEIJ130000500","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000500","url":null,"abstract":"","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131621569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-01DOI: 10.2150/JLVE.IEIJ130000529
Satoshi Hirakawa, Y. Karasawa, T. Funaki, Yukinobu Yoshida
The revealing power was proposed as an index to evaluate visibility in road lighting. However, applicability in tunnel lighting has not been studied. We evaluate the tunnel lighting visibility on the basis of the revealing power in this paper. Our simulation and field experiment, made clear the relationship between the brightness and overall uniformity of the road surface and revealing power. This result confirms tunnel lighting can reduce the road surface luminance while maintaining visibility and can also save energy.
{"title":"Evaluation Index of Visibility in Tunnel Lighting","authors":"Satoshi Hirakawa, Y. Karasawa, T. Funaki, Yukinobu Yoshida","doi":"10.2150/JLVE.IEIJ130000529","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000529","url":null,"abstract":"The revealing power was proposed as an index to evaluate visibility in road lighting. However, applicability in tunnel lighting has not been studied. We evaluate the tunnel lighting visibility on the basis of the revealing power in this paper. Our simulation and field experiment, made clear the relationship between the brightness and overall uniformity of the road surface and revealing power. This result confirms tunnel lighting can reduce the road surface luminance while maintaining visibility and can also save energy.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116707909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maintenance factors in installation of tunnel lighting have been considered in terms of traffic volume and tunnel length based on results from investigations into the use of tunnels. Ventilation conditions in tunnels are drastically improved by reinforcing exhaust gas regulations for cars, and dirt on luminaire is also remarkably reduced. Further, the life times of light sources are advancing. Therefore, we studied lumen maintenance factor, survival factor and partial maintenance factor by using dirty luminaire to take maintenance factor into consideration and these suggested a new method of establishing maintenance factor.
{"title":"Maintenance Factor in Tunnel Lighting Installation","authors":"Satoshi Hirakawa, Kunio Toeda, Tsuyoshi Sugawara, Shoetsu Sakamoto","doi":"10.2150/JLVE.IEIJ130000495","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ130000495","url":null,"abstract":"Maintenance factors in installation of tunnel lighting have been considered in terms of traffic volume and tunnel length based on results from investigations into the use of tunnels. Ventilation conditions in tunnels are drastically improved by reinforcing exhaust gas regulations for cars, and dirt on luminaire is also remarkably reduced. Further, the life times of light sources are advancing. Therefore, we studied lumen maintenance factor, survival factor and partial maintenance factor by using dirty luminaire to take maintenance factor into consideration and these suggested a new method of establishing maintenance factor.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117351571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-01DOI: 10.2150/JLVE.IEIJ120000481
X. Long, R. Liao, Jing Zhou, Zeng Zhi
The junction temperature of the gallium nitride based light emitting diode (LED) is one of the critical parameters that developed the LED luminaries system with high efficacy, long lifetime, and smart functions. Numerous efforts have been conducted to measure and manage the junction temperature that drove multiple LED array at a steady electrical power during the design stages. However, the emerging functional LED luminaries system needs a dynamic and on-line junction temperature measurement, which makes these successful methods less likely to be applied directly on due to cost and complexity issues. Therefore, the junction temperature analysis of the LED array with configurable electrical power becomes an important topic to simplify the junction temperature estimation. In the present paper, a prototype, built by a 3-chip on board based LED array with pulse-width modulation based constant peak current resources, has been tested initially by thermal infrared imager. Then the junction temperature properties including the non-uniform, nonlinear, and superposed are discussed and modeled using finite element method code COMSOL and the thermal equivalent network method. Finally, a simple and fast junction temperature estimator based on the explored properties is given and validated. The suggested methodology and the analysis results shed light on the estimation and control of the junction temperature of LED arrays in smart solid-state lighting.
{"title":"Investigation on Junction Temperatures of Multichip-on-Board Packaged Light Emitting Diodes with Configurable Electrical Power","authors":"X. Long, R. Liao, Jing Zhou, Zeng Zhi","doi":"10.2150/JLVE.IEIJ120000481","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ120000481","url":null,"abstract":"The junction temperature of the gallium nitride based light emitting diode (LED) is one of the critical parameters that developed the LED luminaries system with high efficacy, long lifetime, and smart functions. Numerous efforts have been conducted to measure and manage the junction temperature that drove multiple LED array at a steady electrical power during the design stages. However, the emerging functional LED luminaries system needs a dynamic and on-line junction temperature measurement, which makes these successful methods less likely to be applied directly on due to cost and complexity issues. Therefore, the junction temperature analysis of the LED array with configurable electrical power becomes an important topic to simplify the junction temperature estimation. In the present paper, a prototype, built by a 3-chip on board based LED array with pulse-width modulation based constant peak current resources, has been tested initially by thermal infrared imager. Then the junction temperature properties including the non-uniform, nonlinear, and superposed are discussed and modeled using finite element method code COMSOL and the thermal equivalent network method. Finally, a simple and fast junction temperature estimator based on the explored properties is given and validated. The suggested methodology and the analysis results shed light on the estimation and control of the junction temperature of LED arrays in smart solid-state lighting.","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133859731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-01DOI: 10.2150/JLVE.IEIJ13A000105
Kentaro Koyama
{"title":"Lighting Design of the Matsumae Park","authors":"Kentaro Koyama","doi":"10.2150/JLVE.IEIJ13A000105","DOIUrl":"https://doi.org/10.2150/JLVE.IEIJ13A000105","url":null,"abstract":"","PeriodicalId":311488,"journal":{"name":"Journal of Light & Visual Environment","volume":"910 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131994197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：