The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow...The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow band filters with different center wavelengths ranging from ultraviolet to near infrared wavelength were used to capture images of weld pool during both the peak current period and the base current period of P-GMA W （ pulsed gas metal arc welding）. The experimental results showed that the filters with near infrared center wavelength could weaken the arc most during the peak current period, while during the base current period the entire weld pool could be seen with the filters with wavelength above 600 nm. The camera spectral response and the radio of arc to weld pool emission were considered to analyze the phenomenon of experimental results.展开更多
We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In th...We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In the experiment,we fabricate the birefringent filter using quartz phase retarders and polarizers,and apply it in serval different displays.The color gamuts of displays are enhanced more than 30%NTSC(National Television System Committee),and the widest color gamuts that have been obtained are 126%NTSC in liquid crystal displays and 138%NTSC in organic light-emitting devices.Moreover,the deep blue light in spectrum of display can be reduced using the birefringent filter.The birefringent filter can be an efficient element to achieve wide color gamut display.展开更多
基金Acknowledgement The authors are grateful to the financial support for this project from the National Natural Science Foundation of China under grant No. 51005069.
文摘The selection of narrow band filter＇s center wavelength has an important influence on the quality of the weld pool image captured in passive vision mettmd for controlling arc welding process. In this paper, 29 narrow band filters with different center wavelengths ranging from ultraviolet to near infrared wavelength were used to capture images of weld pool during both the peak current period and the base current period of P-GMA W （ pulsed gas metal arc welding）. The experimental results showed that the filters with near infrared center wavelength could weaken the arc most during the peak current period, while during the base current period the entire weld pool could be seen with the filters with wavelength above 600 nm. The camera spectral response and the radio of arc to weld pool emission were considered to analyze the phenomenon of experimental results.
基金the National Natural Science Foundation of China(Grant Nos.61475042,11304074,and 11274088)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2015202320 and GCC2014048).
文摘We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In the experiment,we fabricate the birefringent filter using quartz phase retarders and polarizers,and apply it in serval different displays.The color gamuts of displays are enhanced more than 30%NTSC(National Television System Committee),and the widest color gamuts that have been obtained are 126%NTSC in liquid crystal displays and 138%NTSC in organic light-emitting devices.Moreover,the deep blue light in spectrum of display can be reduced using the birefringent filter.The birefringent filter can be an efficient element to achieve wide color gamut display.
