Abstract: We review recent advances in quantum dot (QD)- enhanced liquid crystal displays (LCDs), including material formulation, device configuration, and system integration. For the LCD system, we first compare the color gamut difference between the commonly used Gaussian fitting method and that using real emission spectra. Next, we investigate the Helmholtz–Kohlrausch effect. Our simulation results indicate that QD-enhanced LCD appears 1.26X more efficient than organic light-emitting diode (OLED) display due to its wider color gamut. Finally, two new trends for QD-LCDs are discussed: 1) replacing conventional color filters with a QD array, and 2) emerging quantum rod (QR)-enhanced backlight. Their inherent advantages, technical challenges, and potential solutions are presented. We believe the prime time for QD-enhanced LCDs is around the corner.

Abstract: The advent of wide color-gamut LED backlight technology greatly improves the user experience in visions. The bottleneck restricting progress of this technology is to develop red phosphor with satisfactory spectral features and low cost. Herein, a novel non-rare-earth K2XF7:Mn4+ (X = Ta, Nb) was successfully designed and synthesized, exhibiting an admirable quantum efficiency of ∼93.5%, an extremely narrow FWHM of ∼2.3 nm, and a high color purity of ∼99.6%. Unlike the previously reported Mn4+ activated fluorides, Mn4+ in K2XF7 suffers highly distorted octahedral environment in C1 (or C2v) group symmetry, enabling the appearance of intense zero phonon line and distinctive vibronic transitions. Systematical high-resolution spectroscopic analyses down to 10 K disclose the influences of strong crystal field, weak nephelauxetic effect, and intermediate electron-phonon coupling are responsible for the peculiar spectral features of Mn4+ in K2XF7. Impressively, a wide color-gamut reaching up to 86.7% NTSC is realized, demonstrating great validity of K2XF7:Mn4+ for LCD backlights. The present study not only brings a brand-new kind of Mn4+ activated host to the sight of phosphor community (the host can be extended to surges of tantalum/niobium fluorides), but also may enlighten researchers to design highly distorted environment to achieve unique spectral properties of Mn4+.

Abstract: We propose to use a hybrid downconverter system comprising low-cost green perovskite-polymer composite films for liquid crystal display (LCD) backlight unit (BLU) to realize wide color gamut Recently, ultrastable, highly luminescent CH3NH3PbBr3 (MAPbBr3) organic-inorganic perovskite-polymer composite films have been developed These films exhibit outstanding color quality with a full-width-at-half-maximum (FWHM) of only 18 nm and a peak wavelength of 530 nm, which makes them promising candidates as green downconverters Two configurations to hybridize these green films with state-of-the-art red emitting downconverters, including CdSe-based quantum dots (QDs) and narrow peak phosphors, are proposed Color and efficiency analyses indicate that the hybridization of green perovskite-polymer films with red K2SiF6:Mn4+ (KSF) phosphor could lead to wide color gamut coverage of nearly 90% Rec 2020 and high total light efficiency (TLE) of around 20 lm/W while maintaining low cost

Abstract: A multi-view pixel directional backlight module and a naked-eye 3D display device are provided. The multi-view pixel directional backlight module includes at least two rectangular light guide plates closely stacked together. A light-emerging surface of the rectangular light guide plate is provided with multiple pixel arrays. Light emitted by pixels in a same pixel array is pointed to a same viewing angle, and different pixel arrays have different viewing angles. At least one side of each rectangular light guide plate is provided with a light source group. Light emitted by the light source group enters the corresponding light guide plate, then emerges from pixels of respective pixel arrays on the light-emerging surface of the light guide plate, and is totally reflected at positions other than positions of the pixels within the light guide plate. Each of the pixels is a nano-diffraction grating.

Abstract: We propose a high dynamic range (HDR) liquid crystal display (LCD) with pixel-level local dimming. The device structure consists of a pixelated LCD dimming panel to control the backlight intensity entering the master LCD panel. According to our analysis and test cell experiment, this dual-panel display system possesses exceedingly high contrast ratio (> 1,000,000:1) and high bit-depth (> 14 bits) at merely 5 volts. Meanwhile, to mitigate the Moire effect induced by the cascaded thin-film transistor (TFT) backplanes, we separate the two LCD panels with a polarization-dependent scattering film. The pros and cons of this HDR display are discussed.

Abstract: An optically efficient liquid-crystal display (LCD) structure using a patterned quantum dot (QD) film and a short-pass filter (SPF) was proposed and fabricated. The patterned QD film contributed to the generation of 95% in the area ratio (or 90% in the coverage ratio) of the Rec. 2020 color gamut. This was achieved by avoiding the problem of interaction between white backlight and broad transmittance spectra of color filters (CFs) as seen in a conventional LCD with a mixed QD film as a reference. The patterned QD film can maintain the narrow bandwidth of the green and the red QD colors before passing through the CFs. Additionally, the optical intensities of the red, green, and blue spectra were enhanced to 1.63, 1.72, and 2.16 times the reference LCD values, respectively. This was a result of separated emission of the red and green patterned QD film and reflection of the red and green light to the forward direction by the SPF.

Abstract: A backlight module, including a light guide plate and a flexible circuit board, wherein an edge of the light guide plate is provided with plural light source mounting holes disposed along a thickness direction of the light guide plate; a light source is mounted in every light source mounting hole in such a manner that a light emitting surface of the light source is attached onto a hole wall of the light source mounting hole; plural groups of anode-cathode conductive parts are disposed on the flexible circuit board in one-to-one correspondence with the plural light source mounting holes, each being connected to an anode and a cathode of the light source in a corresponding light source mounting hole. The backlight module improves the brightness and uniformity of the light entering the light guide plate. A liquid display device including the above-mentioned backlight module is further provided.

Abstract: The display backlight generated using sharp β-sialon:Eu (green) and K2SiF6:Mn (red) phosphors shows a very wide color gamut that mostly covers the whole National Television System Committee (NTSC) triangle. In this work, an alternative green phosphor is investigated to further improve the display color gamut. γ-AlON:Mn,Mg is a green phosphor that shows a shorter and narrower emission spectrum than sharp β-silaon:Eu. The display color gamut in the blue-green region is thus widened greatly by substituting γ-AlON:Mn,Mg for sharp β-sialon:Eu. The color gamut of displays with γ-AlON:Mn,Mg and K2SiF6:Mn exceeds 100% of the NTSC standard both in the CIE 1931 and the CIE 1976 color spaces. Furthermore, the white LEDs with γ-AlON:Mn,Mg have excellent stability that is comparable to those of LEDs with sharp β-sialon:Eu.

Abstract: The invention discloses a backlight module which comprises light guiding plate, a first light source assembly and a second light source assembly The light guiding plate is provided with a central line The first light source assembly is arranged at a first corner of the light guiding plate, and comprises a first read light source, a first green light source and a first blue light source The second light source assembly is arranged at a second corner of the light guiding plate, and comprises a second red light source, a second green light source and a second blue light source The first read light source, the first green light source and the first blue light source are respectively and sequentially arranged to be symmetrical to the second red light source, the second green light source and the second blue light source, relative to the central line Therefore, red light, green light and blue light emitted by the red light sources, the green light sources and the blue light sources of the two light source assemblies respectively can be guided by the light guiding plate and mixed evenly

Abstract: We propose to add a functional reflective polarizer (FRP) in the backlight unit to suppress the crosstalk between red, green and blue color filters of a liquid crystal display (LCD) panel. When incorporated with a commercial two-phosphor-converted white light-emitting diode (2pc-WLED), the color gamut of the LCD can be improved from 92% to 115% NTSC standard, which is comparable to the cadmium-based quantum dot (QD) backlight. If a narrow-band color filter is employed, the color gamut can be further enhanced to 135% NTSC. Our design offers an alternative approach to QDs, while keeping low cost and long lifetime. Such a simple yet efficient approach would find widespread applications for enlarging the color gamut of LCDs.

Abstract: A two-dimensional/three-dimensional (2D/3D) switchable display backlight and a 2D/3D switchable electronic display employ a switchable diffuser to support 2D/3D switching. The 2D/3D switchable display backlight includes a plate light guide, a multibeam diffraction grating to couple light out of the plate light guide and the switchable diffuser to intercept and selectably either pass or scatter light beams of the coupled-out light. The 2D/3D switchable electronic display includes the backlight and further includes a light valve array to modulate the coupled-out light. The switchable diffuser facilitates selectability between a three-dimensional pixel and a two-dimensional pixel of the 2D/3D switchable electronic display.

Abstract: The feasibility of quantum dot (QD)-based silicone composites as suitable candidates, in terms of down conversion efficiency, for the replacement or the enhancement of color filters in high-brightness liquid crystal displays is investigated for the first time. It is demonstrated that the replacement of color filters (CFs) with a full color conversion QD composites can lead to an 86.16% enhancement in energy efficiency over the conventional LCD with phosphor-converted white light-emitting diodes and RGB CFs as backlighting. A potential second-type technology utilizing QD-on-CF for color generation is also investigated, and it is found that the energy efficiency enhancement can reach 86.86%. In addition to QDs, the state-of-art red and green phosphors are also investigated for the purpose of enhancement of color filters in LCD displays in terms of down conversion efficiency, and the result shows a 105.78% enhancement in overall down conversion efficiency. The energy efficiency of QD-based color conversion composites can be further improved by optimization of QD dispersion in the resin, which makes them more suitable replacement for color filters in LCDs due to some intrinsic limitations in phosphor materials.

Abstract: The utility model discloses a backlight and liquid crystal display module. This backlight includes the metal frame, sets up light guide plate, setting in the metal frame are in the plain noodles is gone into to the light guide plate light emitting source, setting are in the reflector plate of plain noodles one side is kept away from out to the light guide plate, the reflector plate is close to removing outer all the other of light emitting source one end no. 3 are served all including pasting a plurality of on the corresponding side of light guide plate bordure the structure and with a plurality of extension structures of aliging in the corresponding side of metal frame, perhaps the reflector plate is close to removing outer all the other of light emitting source one end no. 3 are served all including pasting bordure structure and being close to removing of a plurality of on the corresponding side of light guide plate outer all the other two jiaos of two jiaos light emitting sources respectively be provided with with metal frame two jiaos of corresponding extension structures of aliging. This backlight need not outside the inside increase of backlight the accessory can realize the counterpoint design between light guide plate, reflector plate and the metal frame, with low costs, efficient.

Abstract: An LCD backlight that is a white light emitting unit is made to emit intense light as white light, and an infrared light emitting unit that emits infrared light for capturing a live view image is turned off. In such a situation, an imaging unit captures a visible light image. The present disclosure can be applied to imaging devices.

Abstract: The invention discloses a backlight module. The backlight module comprises a light guiding plate, a light source installed at one side of the light guiding plate, a reflector plate installed below the light guiding plate, and a brightening film installed above the light guiding plate. The brightening film comprises a polymer film layer containing a quantum material and a polymer film layer containing a metal nano-material. The backlight module can be used for a liquid crystal display. The brightening film of the backlight module comprises the polymer film layer containing the quantum material and the polymer film layer containing the metal nano-material. High-polarization blue, red and green light can be obtained at the same time in the maximum efficiency.

Abstract: Multiview displays include a backlight and a screen used to form a plurality of multiview pixels. Each multiview pixel includes a plurality of sets of light valves. The backlight includes a light source optically coupled to a plate light guide configured with a plurality of multibeam diffraction gratings. Each multibeam diffraction grating corresponds to a set of light valves and is spatially offset with respect to a center of the set of light valves toward a center of the multiview pixel. The plurality of multibeam diffraction gratings is also configured to diffractively couple out light beams from the plate light guide with different diffraction angles and angular offsets such that at least a portion of the coupled-out light beams interleave and propagate in different view directions of the multiview display.

Abstract: Multiview displays include a backlight and a screen used to form a plurality of multiview pixels Each multiview pixel includes a plurality of sets of light valves The backlight includes a light source optically coupled to a plate light guide configured with a plurality of multibeam elements Each multibeam element corresponds to a set of light valves and is spatially offset with respect to a center of the set of light valves toward a center of the multiview pixel The plurality of multibeam elements are also configured to couple out light from the plate light guide with different angles and angular offsets such that at least a portion of the coupled-out light beams interleave and propagate in different view directions of the multiview display

Abstract: In this paper, we propose an image enhancement system to maintain human visual perception for low-backlighted LCD or LED displays. Adopting the low-backlight mode can save electrical power and extend battery life. First, we examine the relationship between the image and backlight to maintain visual perceptual quality. Then, we use an adaptive illumination estimation to decompose the image intensity into an illumination layer and a reflectance layer with multiscale and parallel perspectives. We then refer to the given backlight level and our derived image-backlight relationship to compensate the illumination layer and meanwhile enhance the reflectance layer. Finally, we also boost the color saturation. Experiments using both numerical blind/referenceless image spatial quality evaluator and subjective mean opinion score demonstrate that our system outperforms existing systems.

Abstract: The invention relates to a Micro-LED (Micro-light emitting diode) array backlight source-based ink-jet printing quantum dot display device, which comprises a Micro-LED substrate, wherein a plurality of RGB (red, green and blue) pixel units arranged in an array are arranged on the Micro-LED substrate; each RGB pixel unit comprises a red quantum dot unit, a green quantum dot unit and a transparent unit; each red quantum dot unit comprises a Micro-LED chip and a red quantum dot material, and the red quantum dot material is excited by blue light emitted by the Micro-LED chip to emit red light; each green quantum dot unit comprises a Micro-LED chip and a green quantum dot material, and the green quantum dot material is excited by blue light emitted by the Micro-LED chip to emit green light; each transparent unit comprises a Micro-LED chip and a transparent material, and the transparent material is used for directly transmitting blue light emitted by the Micro-LED chip; a transparent material for packaging is arranged outside the RGB pixel units. According to the device, an ink-jet printing technology is adopted for film forming of quantum dots, so that the problems of complexity and low yield of an RGB tri-color process for manufacturing a Micro-LED full-color product are solved, and batch operation is realized.

Abstract: The invention provides a fingerprint identification method and terminal. The method is suitable for a device comprising a liquid crystal display (LCD). A backlight region of the LCD is provided with an infrared light-emitting diode (LED); and all space or a specific region between a liquid crystal layer of the LCD and lower substrate glass is provided with an infrared sensor. The method comprises the following steps: the device obtains infrared light information through the infrared sensor; and the device identifies fingerprint information according to the infrared light information, thereby realizing fingerprint identification of the infrared light information reflected by user fingers by utilizing the infrared sensor. The infrared sensor and the infrared LED are integrated in the LCD, thereby improving utilization rate of the LCD space, preventing occupation of the whole machine space and realizing non-contact fingerprint identification.

Abstract: The embodiment of the invention relates to a photographing method and device. The method comprises the following steps of: obtaining the light intensity and the colour saturation of a current environment; calculating a difference value between the light intensity of the current environment and the pre-set standard light intensity, and calculating a difference value between the colour saturation of the current environment and the pre-set standard colour saturation; comparing the current light intensity difference value with a pre-stored light intensity difference value and a screen backlight brightness control parameter table, and adjusting the backlight brightness of a screen according to a screen backlight brightness control parameter corresponding to the current light intensity difference value; and, comparing the current colour saturation difference value with a pre-stored colour saturation difference value and a screen display gray-level image control parameter table, and adjusting a gray-level image displayed in the screen according to a screen display gray-level image control parameter corresponding to the current colour saturation difference value. By means of the embodiment of the invention, the light supply effect is good; and the photographing effect is good.

Abstract: A display may have a backlight unit that provides backlight illumination. The backlight unit may include a light guide that distributes light throughout the display and an electrically adjustable lens array. The lens array may have lenses such as liquid lenses or liquid crystal lenses. By adjusting the lenses in the lens array, the angles of rays of backlight from the backlight unit may be adjusted to adjust the angle-of-view of the display. The angle-of-view of the display may also be adjusted using an electrically controllable filter layer. The electrically controllable filter layer may have a liquid crystal layer or a polymer dispersed liquid crystal layer that can be controlled using electrodes. When the electrodes apply signals to the electrically controllable filter layer, portions of the filter layer change to a dark or translucent state and restrict the angle-of-view of the display.

Abstract: The present invention relates to the field of fingerprint identification, and more particularly to a fingerprint identification method and a mobile terminal The method is applied to the mobile terminal The mobile terminal comprises a fingerprint identification module with the backlight The method comprises: if a touch operation to a fingerprint identification area is detected, obtaining the touch operation and an effective contact area of the fingerprint identification area; according to the effective contact area, controlling the illumination area of the backlight when the fingerprint identification module scans the fingerprint; and obtaining fingerprint information scanned by the fingerprint identification module according to the illumination area, and identifying the fingerprint information By virtue of the embodiments of the present invention, according to the touch operation and the effective contact area of the fingerprint identification area, the illumination area of the backlight can be automatically controlled, so that the illumination area is corresponding to the effective contact area, problems the existing optical fingerprint identification method has large power consumption in the backlight and poor appearance experience are solved, and technical effects of reducing power consumption and improving the appearance experience are achieved

Abstract: A display device includes a display panel, a light guide plate, a light source unit, a wavelength conversion sheet which is disposed between the display panel and the light guide plate, and a bottom chassis where the wavelength conversion sheet includes a first portion which covers an upper surface of the light guide plate, the first portion including a first edge extending in a first direction and a second edge facing the first edge, a second portion which extends from the first edge toward the bottom chassis, is coupled to the bottom chassis and covers a first side surface of the light guide plate, and a third portion which extends from the second edge toward the bottom chassis, is coupled to the bottom chassis and covers a second side surface of the light guide plate.

Abstract: The embodiment of the invention provides a substrate and a preparation method thereof, a display panel and a display device and relates to the technical field of display The backlight utilization rate can be increased, and crosstalk can be reduced The substrate comprises a first photoluminescence layer arranged in a first sub-pixel region and a second light filtering layer arranged in a second sub-pixel region The first photoluminescence layer emits light in a first color under excitation of light in a second color, and the second light filtering layer is used for filtering at least part of light except for the light in the second color

Abstract: In the traditional liquid crystal display, at least two-thirds of the energy is wasted by tricolor separation color filter array due to its blocking working principle. In this paper, a well arrangement quantum dots (QD) array, which is excited by blue back light, was fabricated to spatially separate the red-green-blue (RGB) color. This QD array is further placed onto traditional color filter array, by matching the corresponding color filter pixel, in order to eliminate the blue light cross talk. In this case, the energy efficiency of this QD active color filter array no longer depends on its geometric arrangement and absorption properties, but depends on the quantum yield of QDs. Furthermore, 90% Adobe RGB color gamut can be achieved. One advantage of our fabrication method is synthesizing the QDs array onto the substrate directly, without the requirement of dissolving the QDs into other media. This technique may provide a new method to obtain higher color separation efficiency in liquid crystal display (LCD) than the traditional color filter matrix by enhancing the quantum yield of QDs.

Abstract: Methods, systems, computer-readable media, and apparatuses for biometric imaging are presented. The biometric imaging can include emitting light, using a light emitter, wherein the emitted light passes through a display comprising quantum dots. The quantum dots can be configured to emit non-visible light. The biometric imaging can further include sensing, using a sensor, the non-visible light emitted from the quantum dots and reflected from an object to be imaged.

Abstract: The embodiments of the invention disclose a method for adjusting the backlight brightness of a screen and a terminal. The method comprises the steps of: acquiring a parameter index of environmental light in current environment, wherein the parameter index includes light intensity; judging whether pre-stored historical adjusting information has backlight brightness matched with the current environmental light, if not, acquiring a parameter index and first backlight brightness of first environmental light as well as a parameter index and second backlight brightness of second environmental light according to the light intensity of the current environmental light and the historical adjusting information, and acquiring the backlight brightness of the current environmental light based on a preset rule according to the parameter index and first backlight brightness of the first environmental light, the parameter index and second backlight brightness of the second environmental light and the parameter index of the current environmental light; and adjusting the screen according to the acquired backlight brightness. The historical adjusting information comprises backlight brightness manually adjusted by a user and a parameter index of environmental light. The method can meet the requirement of users for adjusting the backlight brightness by using respective adjusted terminals, and improves the experience effect.