Shinichi Uehara

1-inch diagonal transflective 2D and 3D LCD with HDDP arrangement

We have developed a 1-inch diagonal transflective 2D/3D-LCD with a novel pixel arrangement, called HDDP (Horizontally Double-Density Pixels). In the HDDP arrangement, both horizontal and vertical resolutions are equal, which not only results in high 3D image quality, but also means that 2D images, such as characters, can be displayed perfectly. With this design, both 3D and 2D images can be displayed simultaneously in the same picture with no need for 2D/3D mode-conversion. In order to avoid increasing power consumption, we chose to use a lenticular lens and a transflective mode which employs ambient light. In transflective mode, so as not to reduce the 3D visible zone, we use a horizontal stripe reflector, which divides each dot into a transmissive region and a reflective region vertically, without dividing the 3D visible zone into transmissive or reflective zones. As a result, a wide 3D visible zone has been achieved. In addition, in order to avoid image degradation caused by a combination of a micro structure on the reflector and a lenticular lens, we optimized the micro structure and defocused the lenticular lens. Its small size, high visibility and lowpower consumption can broaden the applications of 3D displays.

31.3: Reduction and Measurement of 3D Moiré Caused by Lenticular Sheet and Backlight

We found that interference between a 3D displays lenticular sheet and backlight prism sheet causes 3D moire. This previously unknown phenomenon affects image quality. Its mechanism, reduction methods and their implementation results are described. An appropriate measurement method for 3D moire is also proposed.

A 470 × 235-ppi poly-Si TFT-LCD for high-resolution 2-D and 3-D autostereoscopic displays

— We have developed a 470 × 235-ppi poly-Si TFT-LCD with a novel pixel arrangement, called HDDP (horizontally double-density pixels), for high-resolution 2-D and 3-D autostereoscopic displays. 3-D image quality is especially high in a lenticular-lens-equipped 3-D mode because both the horizontal and vertical resolutions are high, and because these resolutions are equal. 3-D and 2-D images can be displayed simultaneously in the same picture. In addition, 3-D images can be displayed anywhere and 2-D characters can be made to appear at different depths with perfect legibility. No switching of 2-D/3-D modes is necessary, and the designs thin and uncomplicated structure makes it especially suitable for mobile terminals.

Dual-lenticular-lens-based 2-D/3-D convertible autostereoscopic display

— A 2-D/3-D convertible display using two lenticular lenses has been developed. It shows 2-D pictures in full resolution and 3-D autostereoscopic pictures in half resolution by moving one lens relative to the other. The lens assembly consists of thin metal frames, two lenticular lenses, and two shape-memory-alloy (SMA) wires used as actuators. While this assembly is applicable to flat-panel displays of any kind, its simple structure and low power consumption make it best suited to mobile terminals, such as PDAs and mobile phones. Here, we describe its structure and present evaluation results.

High‐visibility 2‐D/3‐D LCD with HDDP arrangement and its optical characterization methods

— A 3.1-in.-diagonal 2-D/3-D LCD with a novel pixel arrangement, called horizontally double-density pixels (HDDP), for high-quality 3-D images has been developed. 3-D visibility has been improved by broadening the qualified stereoscopic viewing space (QSVS) where high-quality 3-D images can be seen. In order to evaluate the QSVS, optical characterization methods, based on the ergonomics for stereoscopy, such as 3-D crosstalk, interocular luminance difference and 3-D moire have been proposed. The implementation results show that these methods can correctly evaluate high-visibility autostereoscopic displays.

Influence of 3‐D cross‐talk on qualified viewing spaces in two‐ and multi‐view autostereoscopic displays

— To estimate the qualified viewing spaces for two- and multi-view autostereoscopic displays, the relationship between image quality (image comfort, annoying ghost image, depth perception) and various pairings between 3-D cross-talk in the left and right views are studied subjectively using a two-view autostereoscopic display and test charts for the left and right views with ghost images due to artificial 3-D cross-talk. The artificial 3-D cross-talk was tuned to simulate the view in the intermediate zone of the viewing spaces. It was shown that the stereoscopic images on a two-view autostereoscopic display cause discomfort when they are observed by the eye in the intermediate zone between the viewing spaces. This is because the ghost image due to large 3-D cross-talk in the intermediate zone elicits different depth perception from the depth induced by the original images for the left and right views, so the observers depth perception is confused. Image comfort is also shown to be better for multi-views, especially the width of the viewing space, which is narrower than the interpupillary distance, where the parallax of the cross-talking image is small.

P-68: High-visibility 2D/3D LCD with HDDP Arrangement and its Evaluation Results using Fourier Optics Instrument

Abstract We have developed a high-visibility 2D/3D LCD with widened space for 3D viewing. The evaluation results using a Fourier optics instrument confirm high visibility, which corresponds to the subjective evaluation. We discuss two kinds of definition of optimum viewing distance, and the appropriateness is described. 1. Introduction With the improvement in the performance of displays, such as LCDs and PDPs, a variety of 3D displays not requiring special glasses have recently been developed for entertainment, medical, design, and other applications. Although they seem to hold promise for use as next-generation displays, for making exciting growth objective evaluation methods, such as measurement methods, should be established. For that purpose, recently, many organizations for standardization, such as ISO, IEC, ICDM and so on, have started developing standards for 3D displays. We consider that the standards should be based on the essence of 3D displays correctly, and measurement methods should be required to measure the performance of 3D displays appropriately, otherwise the performance would not be shown correctly, thus misleading the development of 3D displays, such as improvement of undesirable performance or meaningless competition in specifications. In particular for 3D displays not requiring special glasses, that are often known as autostereoscopic displays, it is difficult to say that a common understanding has already been developed in the world, therefore careful discussion is needed. We consider that the certification of space for 3D viewing is essential to autostereoscopic displays. This space is called QSVS (Qualified Stereoscopic Viewing Space) or OVR (Optimum Viewing Region), which means that 3D images can be viewed in this space without VFSD (Visual Fatigue caused by Stereoscopic Displays) [1]. The ergonomic factors of VFSD peculiar to autostereoscopic display are suggested to be crosstalk, luminance, color (chromaticity) and contrast. Among these factors, the crosstalk, which is often called 3D crosstalk in autostereoscopic displays, is considered to be a particularly important characteristic, because 3D crosstalk concerns the characteristics of how different images are shown into each eye in order to obtain binocular fusion. Therefore, the QSVS based on 3D crosstalk is important as the first step of measurement, and the QSVS had better be larger with higher quality. In order to obtain the QSVS based on 3D crosstalk, measurement of luminance angular distribution is needed, because 3D crosstalk is calculated as the ratio of luminance. A Fourier optics instrument is extremely well adapted for the measurement of the QSVS, because the full angular profile of luminance is rapidly and easily measured [2]. For the success of autostereoscopic displays, not only the QSVS, but also the quality of 3D images is important. The image quality of autostereoscopic displays is expected to be higher than that of the ordinary 2D displays currently used around us, even if it is seen by only one eye, because sacrificing quality of image will not be accepted by users. This means that the characteristics related to monocular vision are also important for viewing 3D images. In order to improve the 3D image quality, it is effective to use a fully custom-made LCD for autostereoscopic display, because any problems caused by a combination of an LCD and optics, such as lenticular, can be solved. In response to this point, we have developed a 2D and 3D LCD with a novel pixel arrangement, called HDDP (Horizontally Double-Density Pixels) [3]. Both horizontal and vertical resolutions are equal, which results in high 3D image quality. We have also developed a high-quality reflective type [4] and a transflective type of 2D and 3D display [5]. In this paper, we describe the development of a high-visibility 2D/3D LCD with HDDP arrangement, and its evaluation results of QSVS using Fourier optics instrument. We also discuss two kinds of definition of the OVD (Optimum Viewing Distance), which is especially important for establishment of the appropriate standards.

23.3: Characterization of 3D Image Quality on Autostereoscopic Displays — Proposal of Interocular 3D Purity —

We propose “Interocular 3D Purity”; a quantitative measure of the image quality of stereoscopic displays. This measure expresses how well stereopsis-disturbing images are excluded. We apply this measure to three types of display and find it to be effective in analyzing not only the dimensions of stereoscopic viewing spaces but also the smoothness of motion parallax.

44.3: Characterization of Motion Parallax on Multi-view/Integral-imaging Displays

Multi-view and integral imaging displays have a significant feature that allows people to induce better stereopsis due to motion parallax. Base on the analysis of the mechanism, we propose characterization methods of the displays. Our methods evaluate change in luminance of stereoscopic images when observers eye positions are displaced. The results show that our methods are good for showing smoothness of the motion parallax.

22.2: RGB-Stacked Holographic Polymer Dispersed Liquid Crystal Device for Color Reflective Display

In stacking holographic PDLC devices, the parallax in the stack and the viewing angle should be considered. Based on a thin glass substrate (thickness = 0.1mm) assembly technique and an optical setup with a lenticular-lens array, RGB-stacked HPDLC devices with a low parallax and a large viewing angle (>15 degrees) have been developed.