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1.
    
While the viewing angle (VA) is an important parameter of three‐dimensional (3‐D) displays, a method has not yet been devised to determine the VA. We proposed a new approach to determine a VA of an integral imaging display. An integrated point appears at the cross section between collected rays and a lens array; the VA of the integrated point is thus equal to the angle between the two farthest rays. This approach is useful to determine the VA of all 3‐D displays, because a 3‐D point appears in the cross section of collected rays. The result of this study showed that the VA depends on the position of the integrated point and is smaller than the VA of the conventional calculation.  相似文献   

2.
    
We propose a viewing angle switchable blue‐phase liquid crystal display with low voltage and high transmittance. In this device, in‐plane protrusions are used to lower operating voltage and improve the transmittance. Besides, the top electrode can control viewing angle of the proposed display. When no voltage is applied to the top electrode, the display shows wide viewing angle mode. On the contrary, this display shows narrow viewing angle mode. So, this device exhibits low operating voltage, high transmittance, and good viewing angle controllable characteristics.  相似文献   

3.
    
Abstract— Optically compensated bend (OCB) mode is a promising technology, due to its wide range of viewing angles without gray‐scale inversion or color shift, fast response, high contrast ratio, and wide temperature range. This paper summarizes the fundamental characteristics of OCB mode and discusses the development of field‐sequential‐color displays and 3‐D displays for future high‐quality display applications.  相似文献   

4.
    
Abstract— An improved 3‐D/2‐D switchable display system with enhanced depth and viewing angle by adding two LCD panels to an integral imaging system has been realized. The proposed system uses the see‐through property of an LCD panel and displays multiple sets of elemental images on the LCD panels to integrate them on multiple locations simultaneously. As a result, the depth of the 3‐D image can be enhanced. For wide viewing angles, the time‐multiplexing method was adopted by displaying mask patterns on the front LCD panel. In addition, another technique to increase the contrast ratio of the proposed system has also been developed. Some experimental results will be provided.  相似文献   

5.
    
Abstract— This study develops an autostereoscopic display based on a multiple miniature projector array to provide a scalable solution for a high‐resolution 3‐D display with large viewing freedom. To minimize distortion and dispersion, and to maximize the modulation transfer function (MTF) of the projection image to optimize 3‐D image quality, a dedicated projection lens and an accurate six‐axis adjusting platform for the miniature projector were designed and fabricated. Image‐blending technology based on a lookup table was adopted to combine images from 30 miniature projectors into a seamless single image. The result was a 35‐in. autostereoscopic display with 60 views ata 30° viewing angle, 90° FOV, and large range of viewing distance. The proposed system exhibits very smooth motion parallax when viewers move around in front of it.  相似文献   

6.
    
Abstract— An attractive concept for 3‐D displays is the one based on LCDs equipped with lenticular lenses. This enables autostereoscopic multiview 3‐D displays without a loss in brightness. A general issue in multiview 3‐D displays is their relatively low spatial resolution because the pixels are divided among the different views. To overcome this problem, we have developed switchable displays, using liquid‐crystal (LC) filled switchable lenticulars. In this way, it is possible to have a high‐brightness 3‐D display capable of fully exploiting the native 2‐D resolution of the underlying LCD. The feasibility of LC‐filled switchable lenticulars was shown in several applications. For applications in which it is advantageous to be able to display 3‐D and 2‐D content simultaneously, a 42‐in. locally switchable prototype having a matrix electrode structure was developed. These displays were realized using cylindrically shaped lenticular lenses in contact with LC. An alternative for these are lenticulars based on gradient‐index (GRIN) LC lenses. Preliminary results for such switchable GRIN lenses are presented as well.  相似文献   

7.
    
Additive light field displays are transparent autostereoscopic three-dimensional displays without backlights, thus suitable for augmented reality applications. However, when the parallax between viewpoint images becomes large with the increase of viewing angle, the optimization algorithm is hard to handle too many dissimilarities evenly on all viewpoints, resulting in poor reconstructed quality. This paper presents an additive light field display using the weighted simultaneous algebraic reconstruction technique with viewing angle-dependent weight distribution functions. We constrain the optimization to deliver a reconstructed light field of high image quality for viewpoints of large weight. When the proposed method is applied, with a wide dynamic viewing angle of 57° × 43°, the tracked views' peak signal-to-noise ratio exceeds 30 dB with only two additive display layers.  相似文献   

8.
    
Abstract— Liquid‐crystal displays (LCDs) have notable variation in luminance and perceived contrast as a function of the angle from which they are viewed. Though this is an important performance issue for LCDs, most evaluation techniques for assessing this variation have been limited to laboratory settings. This study demonstrates the use of a photographic technique for such an evaluation. The technique is based on an actively cooled charge‐coupled‐device (CCD) detector in combination with a macro lens covering a circular angular range (θ) of ±42.5°. The camera was used to evaluate the luminance and perceived contrast properties of an LCD. Uniform field images corresponding to 17 equally spaced gray‐scale values in the digital driving level (DDL) range of the display system were acquired. The 12‐bit gray‐scale digital images produced by the camera were converted to luminance units (cd/m2) via the measured luminance vs. DDL response function of the camera. The changes in perceived contrast as a function of viewing angle were derived from the Barten model of the gray‐scale response of the human‐visual system using the methods proposed by the AAPM TG18 Report. The results of this photographic technique were compared to measurements acquired from a similar display using a Fourier‐optics‐based luminance meter. The results of the two methods generally agreed to within 5%. The photographic methods used were found to be accurate and robust for in‐field assessment of the angular response of LCDs over the FOV of the camera.  相似文献   

9.
    
Abstract— By using a new pixel design and a novel driving scheme that adds a bias electrode and a bias TFT to the ordinary pixel structure, a high‐contrast‐ratio and wide‐viewing‐angle LCD mode, refered to as the biased vertical‐alignment (BVA) mode, has been sucessfully developed. Compared to the published data on the PVA and MVA modes, the BVA mode has a distinct advantage of lower manufacturing cost due to the elimination of a lithographic process step that forms either ITO cuts or protrusions on the color‐filter substrates. The BVA mode requires ITO cuts on the TFT substrate similar to that for the PVA and MVA modes. The 15‐in. BVA‐mode XGA prototype exhibits a high contrast ratio of 1200:1 and high cell transmittance of 4.3%.  相似文献   

10.
    
Abstract— Viewing‐angle dependences of the contrast ratio and color shift of LCDs have been radically improved as evidenced by the increasing application of LCDs in high‐quality television. This paper describes the concept of optical compensation and the fundamental characteristics of the viewing‐angle property for various LC modes.  相似文献   

11.
    
Abstract— Autostereoscopic and polarization‐based stereoscopic 3‐D displays recreate 3‐D images by providing different images in the two eyes of an observer. This aim is achieved differently for these two families of 3‐D displays. It is shown that viewing‐angle measurements can be applied to characterize both types of displays. Viewing‐angle luminance measurements are made at different locations on the display surface for each view emitted by the display. For autostereoscopic displays, a Fourier‐optics instrument with an ultra‐high‐angular‐resolution VCMaster3D is used. For polarization‐based displays, a standard Fourier‐optics instrument with additional glass filters is used. Then, what will be seen by an observer in front of the display is computed. Monocular and binocular quality criteria (left‐ and right‐eye contrast, 3‐D contrast) was used to quantify the ability to perceive depth for any observer position. Qualified monocular and binocular viewing spaces (QMVS and QBVS) are deduced. Precise 3‐D characteristics are derived such as maximum 3‐D contrast, optical viewing freedom in each direction, color shifts, and standard contrast. A quantitative comparison between displays of all types becomes possible.  相似文献   

12.
协同设计中三维几何模型渐进式快速显示技术研究   总被引：4，自引：1，他引：4  
通过网络传输不同层次的几何点、线、面信息,实现了模型的边传输、边显示和边操作,改善了复杂三维模型由于受到网络带宽的限制导致的传输和显示速度缓慢的状况,克服了传输过程中不能操作模型的缺陷．最后通过实例验证了文中方法的有效性．  相似文献   

13.
    
Viewing positions of autostereoscopic 3D affect the observed 3D image quality. The response of the people who had little experience in viewing autostereoscopic 3D was investigated. Thirty participants with the normal stereoscopic vision were selected and took the visual evaluation of autostereoscopic 3D at the various viewing positions. Photograph was also taken for the quantitative analysis of the viewing zone characteristics and the uniformity of 3D screen of autostereoscopic 3D. In visual evaluation, the larger difference of good and bad 3D image quality was observed at the viewing distance of 300 cm than at other viewing distance. This result and the periodic trends accorded with the analysis of photos at various camera positions. From these, we found that even the unexperienced viewer can correctly evaluate whether 3D image quality is good or bad.  相似文献   

14.
    
Abstract— A 15‐in. TFT‐LCD with XGA resolution using thresholdless antiferroelectric liquid crystal (TLAF) has been developed. TLAF materials show V‐shaped switching and enable display of analog gray scale, wide viewing angle, and fast response. However, in the case that high‐resolution TFT‐LCDs using materials with large spontaneous polarization such as TLAF were driven by the conventional method, alternating current (ac) driving, the obtained contrast ratio was limited because of a sharp decline of holding voltage due to the growth of a depolarization field. In order to enhance the contrast ratio, a novel driving method referred to as quasi‐dc driving was proposed. In the quasi‐dc driving, the polarity of the applied voltage to liquid crystals inverts at certain intervals of several seconds. Moreover, the applied voltage and the charging time at the time of polarity inversion are increased more than the intended signals. By this method, the 15‐in. TFT‐LCD using TLAF with high contrast ratio (more than 100:1) and wide viewing angle was realized.  相似文献   

15.
We have developed a new microstructure film for wide viewing liquid crystal displays (LCDs). By attaching it to the surface of a conventional LCD, the viewing angle characteristics of LCD has drastically improved without causing a blur of the frontal image and a decrease in the contrast ratio under bright ambient light conditions. This film can be applied to various LC modes including twisted nematic and multidomain vertical alignment by changing its internal micrometer‐size 3D structure. Further, this film can be mass‐produced efficiently by self alignment roll‐to‐roll process.  相似文献   

16.
    
Abstract— 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.  相似文献   

17.
    
Abstract— 3‐D cross‐talk typically represents the ratio of image overlap between the left and right views. For stereoscopic LCDs using shutter‐glasses technology, 3‐D cross‐talk for stereoscopic LCD TV with a diagonal size of 46 in. and vertical alignment (VA) mode was measured to change from 1% to 10% when the stereoscopic display is rotated around the vertical axis. Input signals consist of the left and right images that include patterns of different amounts of binocular disparity and various gray levels. Ghost‐like artifacts are observed. Furthermore, intensities of these artifacts are observed to change as the stereoscopic display is rotated about the vertical axis. The temporal luminance of the LCD used in stereoscopic TV was found to be dependent on the viewing direction and can be considered as one cause of the phenomenon of angular dependence of performance for stereoscopic displays.  相似文献   

18.
为了实现广角镜视频图像中的人体检测,设计并实现了基于黑板模式的室内人体检测系统。该系统算法通过排除非人体目标实现人体检测。实验结果表明基于黑板模式的人体检测方法有效,即使在人体局部遮挡、头部旋转和皮肤颜色差异的情况下也同样适用。为使用广角镜摄像机进行室内人体检测提供了一种可行的方法。  相似文献   

19.
    
In the integral imaging (II) system using a curved micro‐lens array (MLA), the viewing angle is limited by the gap mismatch. Here, we propose a system to decrease the gap mismatch for enhancing the viewing angle. In the proposed system, a layer of high‐refractive‐index medium is assembled between the display panel and the curved MLA. The principle of the proposed II system is studied in detail. Simulations based on ray tracing are performed, and the results show that the proposed II system can effectively enhance the viewing angle.  相似文献   

20.
    
Abstract— Several TFT‐LCD devices exhibiting high image quality have been developed and commercialized, overcoming the narrow viewing‐angle characteristics of conventional twisted‐nematic (TN) devices. Nevertheless, no single device dominates large‐sized TFT‐LCDs. In this paper, the product issues of existing LC devices related to manufacturing process and performance are discussed.  相似文献   

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