The key to developing a new type of liquid crystal display (LCD) lighting is to balance light quality with high light efficiency, and the light diffusion plate is an indispensable part of LCD to achieve different light extraction efficiency and light uniformity. In addition, the addition of quantum-dots (QDs) further improves the light transmittance and optical conversion efficiency of the light diffusion plate. In this paper, the surface engineering method was used to prepare QDs composites to improve the stability of QDs diffusion plate under high temperature and humidity. This paper briefly introduced the light diffusion plate, and then discusses the preparation of the QDs composites and the injection molding process of the QDs diffusion plate. Finally, the QDs diffusion plate was assembled into a backlight module, and its stability was tested at 60℃ and 85% relative humidity (RH). The experimental results show that the spectra and external quantum efficiency (EQE) of the QDs diffusion plate do not change significantly after long time storage at high temperature and humidity. This experiment improved the stability of QDs diffusion plate and lays a foundation for the subsequent large-scale production.
The surface modification strategy is widely used to solve the problems of low stability, agglomeration, surface oxidation and photoluminescence quenching of quantum dots (QDs) in practical applications. However this method can easily destroys the surface ligands of QDs, increases defects even leads to a huge loss of fluorescence. In order to improve the stability of QDs, a new synthesis method of QD-silica hybrid nanospheres was proposed in this study. These QD-silica hybrid nanospheres are characterized by using mesoporous silica spheres (MSSs) as template, adsorbing QDs as one shell, and then coating a silica layer as another shell (named SQS). The template MSSs were functionalized by (3-mercaptopropyl) trimethoxysilane (MPTMS) in order to connect MSSs and QDs. After that, the QD-adsorbed silica spheres were coated with silica as the encapsulation layer by Stober method. The structure and morphology of SQS were analyzed by TEM. The effects of different contents of MPTMS and tetraethoxysilane(TEOS) were experimentally compared. Finally, it was found that the optimal contents of MPTMS and TEOS was 250μL and 1.5mL, respectively. The luminescence intensity of SQS samples could reach 2 times higher than that of pure QD solution. Meanwhile, SQS hybrid nanospheres could avoid the tiny spots inside the microstructure caused by QD aggregation and play a better role in dispersion.
Quantum dots (QDs) exhibit exceptional optical qualities, including wide excitation wavelength, small full width at half maximum (FWHM), and photobleaching resistance. It had been used to make color-converting diffusers for backlight modules. In this study, the QDs were added into masterbatches to prepare composite components with the functions of diffusion and color conversion. Using a coextrusion approach, masterbatches were made by adding suitable ratio of red and green QDs as color conversion materials in polystyrene (PS), silicone difussion powder as the light diffusing agent, and adding antioxidants to improve the service life of the masterbatch. After that, the QD color masterbatch with uniform dispersion, controllable concentration and good luminescence performance was obtained. A spectrometer was used to examine the photoluminescence performance of the created masterbatches in order to validate their luminescence performance. As a result, the use of QDs masterbatches is a viable option for the application of high performance QD display device.
The polarization emission has many applications in the field of display, and the key to perovskite polarization emission is large-scale orientation. In this paper, we reported the electric field oriented perovskite nanowires method. The perovskite nanowires with average length of 60nm, radius of 5nm and central wavelength of 509nm were synthesized. Then aligned by alternating electric field, and the polarization was finally measured at 0.33, which was three times better than without the alternating electric field.
Field of view (FOV) of the fisheye lens is close to or even higher than 180°, which brings about extraordinary imaging effect that the visual range would be far wider than the human eye perspective. However, the wide visual range of the fisheye lens is always at the expense of image quantity, so that the images obtained by fisheye lens would inevitably show a large degree of distortion aberration. In this paper, we propose an improved distortion calibration algorithm of longitude-latitude mapping to eliminate the image distortion aberration caused by fisheye lens. This method does not need to depend on a specific physical camera and has general and universal significance. By using Matlab as a mathematical analysis tool, the verified experiment and the corresponding write code is performed to correct a specific fisheye lens’ image based on the previously proposed algorithm. A reverse mapping is used to avoid cross-border problems, and comparative experiments are also analyzed to show the difference between the image processing with the traditional and the proposed algorithm. Experimental results demonstrate that the proposed algorithm can better achieve the correction of fisheye lens distortion. The twisted lines that are not expected can be well corrected into the straight lines. This method can not only reduce the problem of horizontal stretching of the image, but also make the processing results visually consistent with people's viewing habits.
Light Guide Plate (LGP) plays an irreplaceable role in Liquid Crystal Display (LCD) backlight. LGP with quantum-dot (QD) shows promise in the development of next-generation displays because of QDs’ beneficial characteristics. In this paper, we present a novel QD LGP for LCD backlight based on QD scattering microstructure array (SMA), in which the QD net dots are located discretely and arranged in arrays on the bottom surface of LGP. The paper first introduces the QD backlight briefly, then discusses the preparation and fabrication process of the proposed prototype, and finally presents a systematic photometric approach to reveal the remarkable advantages of QD backlight. The white-balance is achieved by adjusting the proportion of the QDs in the mixture and optimizing the R-QD / G-QD ratio. The apparent morphology of QD SMA is characterized by OLYMPUS laser microscope, while the optical properties of QD backlight are investigated by F-4600 fluorescence spectrophotometer and SRC-200M spectrum color luminance meter, respectively. Experimental results show that the white balance can be achieved when the QDs account for a certain proportion about 7% within the mixture, and the ratio of R-QD / G-QD is optimized to about 1:12. The proposed system offers an alternative and feasible method for fabricating QD backlight, which may have great application prospects in the future.
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