| Liquid crystal display(LCD)with low voltage,low power consumption,long life,no radiation,light and other excellent characteristics,has been widely used in all display fileds.However the LCD cannot achieve self-luminous,the backlight module is an important component for LCD.At present,the quantum dots(QDs)materials is gradually taking the place of of conventional phosphor powder as a luminescent material for the backlight module,because the QDs can bring spectral adjustable,narrow FWHM,and can achieve a higher color gamut.In the side lighting backlight system,the net-dot microstructrues under the surface of the light guide plate(LGP)play an important role in achieving the uniformity.In this paper,it is of certain significance to study the combination of QDs and net-dots.Firstly,the backlight module was established by TracePro optical simulation software.In order to investigate backlight system performance,the uniform and staggered net-dot were designed on the under surface of the LGP.The results showed,when the coverage rate was 0.36 ?%,the uniformity of the entile surface light is better,which the maximum brightness was 7369.1 cd/m2,the luminous efficiency was 189.4%and the uniformity was 82.1%on the 16 LED chips and 40000 rays per chip.Similarly,when the coverage rate of the staggered was 0.36 ?%,the maximum brightness of the outgoing light was 7451.7 cd/m2,the luminous efficiency was 189.1%,and the uniformity was 85.2%.Compared this two models,the overall performance was better than the uniform distribution net-dot's.Secondly,the monochromatic and mixed color backlight prototypes were prepared with the QDs slurry by screen printing.Moreover,the influence of the LED driving current on the backlight performances was investigated.The results showed that white light could be achieved when the QDs was 7wt%in the mixture,and the radio of red/green QDs was 1:12,which showed the CIE 1931 color coordinantes of(0.3308,0.3271),CCT of 5588k,brightness of 4136 cd/m2,and a color gamut of 122.4%NTSC.Furthermore,the R/G QDs-LGP backlight system brightness uniformity was 81.2%,the color uniformity was 0.017 by nine points testing.Increasing the working current of LED,the color coordinates were changed slightly.As a whole,the combination of QDs and net-dots has a good stability.Thirdly,the inkjet printing parameters and ink stability were studied.The results showed that the stability of the droplet from nozzle and the deposition morphology of the droplet on the substrate were the best when the frequency of the pulse was 2000 Hz,the nozzle height was 1 mm.In the study of QDs ink,the coffee ring was completely eliminated by adding UV solution in QDs and spin coating UV solution on the substrate.Finally,the monochromatic and mixed color backlight prototypes of QDs were prepared by printing,and the QDs backlight performances were studied.The results showed that the morphology of the QDs net-dots could be improved by increasing the number of cyclic injection,which could obtaine higher backlight brightness and color coordinates under the excitation of the blue LED,but also increased the contact area of the dots.Through the theoretical analysis,the white was achieved by secondary printing,which showed the CIE 1931 color coordinantes of(0.3324,0.3081),a color gamut of 105%NTSC.By nine points testing,the R/G QDs-LGP backlight brightness uniformity was 71.8%,the color uniformity was 0.058.And the color coordinates were changed slightly by changing the drive current in the R/G QDs-LGP.The primary colors of color coordinates remained stable trend,the center wavelength and the color gamut also did not change with different current.In conclusion,the microstructures of QDs net-dots were fabricated by different ways and got the different color backlight under the excitation of LED.In addition,their backlight properties with different technological parameters were studied using scientific methods.And the results would provide references for the application of QDs net-dots microstructures. |
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