In traditional phase measurement deflectometry (PMD), a number of sinusoidal fringe patterns are displayed on the screen in two orthogonal directions, which is time-consuming and not suitable for dynamic measurements. A phase-extraction algorithm based on the spatial-carrier phase-shifting technology for a single-shot spatial-carrier orthogonal fringe pattern is proposed. The phase increment of each pixel in two orthogonal directions is obtained by the least squares method and then the amount of spatial phase shift of all pixels relative to the probe pixel in the rectangular neighborhood centered on the probe pixel can be obtained. The number of fringe patterns required for the PMD is reduced to one by displaying a spatial-carrier orthogonal fringe pattern. Finally, the feasibility of the algorithm is verified by simulation and experiment.
We propose an autostereoscopic three-dimensional (3-D) display using a time-multiplexed method. This display consists of a two-dimensional (2-D) display panel, a time-multiplexed liquid crystal parallax barrier (LCPB), and a lenticular sheet. The 2-D display provides four-view synthetic images. The time-multiplexed LCPB located in front of the 2-D display panel is used to project parallax images in different spatial directions. With the time-multiplexed method, 3-D pixels with different locations can be provided for a time sequence, allowing a high 3-D resolution to be achieved. The lenticular lens is located between the 2-D display panel and the LCPB. Because of congregating ray functions of the lenticular sheet, cross talk can be effectively reduced. We describe the principle and parameter calculations for the prototype of the proposed display. Compared with the conventional autostereoscopic 3-D display, the proposed display has a higher resolution and minimal cross talk.
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.
An adaptive Cylindrical Lens Array (ACLA) for a 2D/3D switchable display is demonstrated. The ACLA is based on two transparent liquids of different refractive indexes and an elastic membrane. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. An ACLA demo for the 2D/3D switchable display is developed. The experimental result shows that the ACLA demo works as a light splitting and 2D/3D switching component of the 2D/3D switchable display effectively and the 2D/3D switchable display is realized.
A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is
demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with
liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2
and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the
elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens
array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for
autostereoscopic 3D displays is emphasized.