Study On Transient Artifacts Of Time Modulated LED

As a new solid-state lighting technology,LED has been widely used due to its quick response speed,high conversion efficiency,green and environmental protection,long life,low voltage,small size and easy dimming.The traditional LED is usually driven by direct current.The ac/dc conversion module can not only cause energy loss,but also limit the overall life of the light source.Due to its low cost and long service life,AC LED has obvious advantages over DC LED.However,as a kind of time-modulated LED,it may cause transient artifacts such as flickering,stroboscopic and phantom arrays due to the temporal nature of the human vision system.This paper mainly studies the phantom array effect under time modulated LED.In this paper,LED light source driven by a programmable waveform generator is used as the research object,and the influence factors and visual threshold of the phantom array effect under time-modulated LED are studied by using the experimental method of subjective psychology.Firstly,the effects of frequency(100Hz,600 Hz,1200Hz)and illumination on the visibility of phantom array effect under time-modulated LED lighting were studied,and the visibility threshold under the corresponding conditions was given,and the results of the visibility threshold values at three frequencies indicating that the visibility threshold of phantom array effect first decreased and then increased with the increase of frequency,showing a u-shaped curve.When the driving frequency of the light source is 100 Hz,the visible threshold has little influence with the change of illumination,while at the frequency of 600 Hz,it can be seen that the threshold first decreases and then increases with the increase of illumination.Secondly,the influence of color temperature on the visibility of phantom array effect was studied.The results showed that the effect of color temperature on the visibility of the phantom array effect is more significant under low illumination.Under the illumination of 50 lux,the color temperature had a significant effect on the visible threshold of phantom array effect,it’s much easier to observe the phantom array effect under low color temperature,while under the illumination of 250 lux,the color temperature had no significant effect on the visibility threshold of phantom array effect.Finally,the phantom array effect under the simulated read and write condition was studied,and the results showed that it is difficult to observe the phantom array effect at low frequency(100Hz 120Hz),while the phantom array is not visible at 600 Hz.