A three-dimensional (3-D) display with optimized view distribution is proposed. The proposed 3-D display consists of a two-dimensional (2-D) display panel, a pixel mask, and a lenticular lens. The 2-D display panel is used to provide parallax images. The pixel mask has a designed pinhole array and is located close to the 2-D display panel. This pinhole array can modulate the location and size of the pixels on the 2-D display panel to provide an optimized view distribution. Finally, the lenticular lens projects the pixels in different spatial directions to form 3-D images. Different from conventional 3-D displays, the proposed 3-D display can concentrate views into the center area and form a better parallax continuity. A prototype of the proposed 3-D display is developed. Experiment results agree well with the theory.
A pixel mask-based three-dimensional (3-D) display with uniform resolution is proposed. This 3-D display consists of a reflected light source, a pixel mask, a liquid crystal display (LCD) panel, and a lenticular lens. The reflected light source is located on the bottom layer of the proposed 3-D display. It has a reflective structure to improve optical efficiency, so it can make up the brightness loss, which is caused by the pixel mask. The pixel mask is located between the reflected light source and the LCD panel, and is attached on the back surface of the LCD panel. This pixel mask is made of a reflective material, and some transparent areas are etched on it. The pixel mask redefines the pixels of the two-dimensional display panel located in front of it, so the size and location of redefined pixels depend on the transparent area of the pixel mask. The arrangement of the redefined pixels can increase the column numbers of synthetic images. Therefore, the synthetic images can make 3-D images have uniform resolution. A 4-view prototype of this display is developed and the experimental result shows the proposed method can improve resolution uniformity successfully.
We propose three dual-view integral imaging (DVII) three-dimensional (3D) displays. In the spatial-multiplexed DVII
3D display, each elemental image (EI) is cut into a left and right sub-EIs, and they are refracted to the left and right
viewing zones by the corresponding micro-lens array (MLA). Different 3D images are reconstructed in the left and right
viewing zones, and the viewing angle is decreased. In the DVII 3D display using polarizer parallax barriers, a polarizer
parallax barrier is used in front of both the display panel and the MLA. The polarizer parallax barrier consists of two
parts with perpendicular polarization directions. The elemental image array (EIA) is cut to left and right parts. The lights
emitted from the left part are modulated by the left MLA and reconstruct a 3D image in the right viewing zone, whereas
the lights emitted from the right part reconstruct another 3D image in the left viewing zone. The 3D resolution is
decreased. In the time-multiplexed DVII 3D display, an orthogonal polarizer array is attached onto both the display
panel and the MLA. The orthogonal polarizer array consists of horizontal and vertical polarizer units and the polarization
directions of the adjacent units are orthogonal. In State 1, each EI is reconstructed by its corresponding micro-lens,
whereas in State 2, each EI is reconstructed by its adjacent micro-lens. 3D images 1 and 2 are reconstructed alternately
with a refresh rate up to 120HZ. The viewing angle and 3D resolution are the same as the conventional II 3D display.
We propose an integral imaging in which the micro-lens array (MLA) in the pickup process called MLA 1 and the micro-lens array in the display process called MLA 2 have different specifications. The elemental image array called EIA 1 is captured through MLA 1 in the pickup process. We deduce a pixel mapping algorithm including virtual display and virtual pickup processes to generate the elemental image array called EIA 2 which is picked up by MLA 2. The three-dimensional images reconstructed by EIA 2 and MLA 2 do not suffer any image scaling and distortions. The experimental results demonstrate the correctness of our theoretical analysis.
We analyze the effect of aperture width of the parallax barrier on the viewing angle of one-dimensional integral imaging (1-DII) display and propose a 1-DII display that consists of a display panel and a variable parallax barrier. When the variable parallax barrier changes its aperture width, the viewing angle and the optical efficiency of the proposed 1-DII display are compared. The viewing angle is increased by decreasing the aperture width of the variable parallax barrier, while the optical efficiency is increased by increasing the aperture width of the variable parallax barrier.
An integral imaging (II) display is proposed which consists of a display panel and a gradient-aperture pinhole array. The gradient-aperture pinhole array is symmetrical in both horizontal and vertical directions. The leftmost and rightmost pinholes are used to fix the horizontal viewing angle, and the uppermost and nethermost pinholes are used to fix the vertical viewing angle. To increase the optical efficiency, the aperture widths of other pinholes are gradually increased from both sides to the middle in the horizontal and vertical directions, respectively. A prototype of the proposed II display is developed. Its horizontal viewing angle is equal to that of the conventional one, while its optical efficiency is higher than that of the conventional one.
Organic light emitting diodes (OLEDs) have attracted much attention for several applications, such as light source and display. It is of both commercial and scientific interests to improve external quantum efficiency of such light emitters. The external quantum efficiency of OLED is determined by the combination of charge balance, singlet-triplet ratio and light extraction efficiency. Application of phosphorescent emitting materials can produce internal quantum efficiency very close to theoretical limitation. However, due to the refractive index mismatch between air and organic emitting layer, most of the emitted light is lost through total internal reflection into substrate and indium-tin-oxide (ITO) waveguiding modes and to self-absorption. Therefore, there is a large space for improvement on the extraction efficiency of the devices. In this paper, A Monte Carlo simulation of external emitted light has been developed. The light extraction factor for planar OLED is 17.17%. This result demonstrates that the light extraction from planar OLEDs can be quantitatively modeled by a simple ray-tracing algorithm. Microlens arrays are introduced on glass substrates to suppress waveguiding loss in the substrate. In this work, we propose to use an etched glass master for fabricating microlens. The glass master is fabricated using a simple wet etching method. A photoresist/Cr/ITO multiplayer mask is made by lithography on the glass substrate and then the glass substrate is etched with HF/HCl solution for improving the quality of generated surface. The isotropic etching profile of the glass master is utilized for microlens replication. Lens arrays are replicated on polymer (PDMS) substrates. With the use of microlens arrays, the light extraction factor is increased experimentally, without detrimental effect to the electrical performance of the OLED.