共查询到20条相似文献，搜索用时 0 毫秒
1.
《Displays》2020
In this paper, a new backlight dimming method using weighted mean-square-error (MSE) based on joint edge-saliency characteristics is proposed. In contrast to conventional backlight dimming methods that cannot accurately evaluate the saturation error and determine the optimal clipping point to achieve the best trade-off between image quality and power consumption, the proposed method, with consideration of human visual characteristics, analyzes the joint edge-saliency characteristics based on spatio-temporal saliency map and edge-strength map of the input images, and weights the MSE accordingly. It can therefore evaluate the allowable saturation error and determine the optimal clipping point. Simulation results show that the proposed method outperforms other benchmark methods in the case of overall consideration of image quality and power consumption. Additionally, the proposed method maximizes the power reduction rate while successfully preserving image details in the regions of interest and maintaining high perceived image quality. Our results also show that the average computation time of the proposed algorithm was reduced by up to 30.184%, 19.162% and 8.027%, respectively, compared with I2GEC, SMVA2 and SPBD algorithms. 相似文献
2.
《Displays》2019
This paper proposes a global backlight dimming algorithm based on structural similarity that controls the local distortion level of the output image for preserving overall image quality. Unlike existing methods, the proposed method non-iteratively determines a global clipping point that maintains structural similarity for each pixel above the desired level. The proposed method consists of three steps: region analysis, candidate clipping point calculation, and backlight luminance determination. In the first step, the structural similarity is analyzed based on various clipping points. In the second step, the proposed method estimates a candidate clipping point, which preserves the structural similarity index of each pixel above the desired level, based on the estimation of local statistics. Then, the proposed method determines a global clipping point based on a group of candidate clipping points. Finally, the output luminance is determined based on the selected global clipping point. Experimental results showed that the proposed method successfully maintained the structural similarity of each pixel above the desired level. In addition, the proposed method reduced the variation of minimum structural similarity by up to 94.7% compared to the benchmark methods. 相似文献
3.
《Displays》2017
In a conventional backlight, suppression of light loss caused by the prism film(s) is desired to enhance the luminance without sacrificing the viewing angle. In this paper, in a direct-lit light-emitting diode (LED) backlight, where an LED array is placed under the display panel, the transmission efficiency against the prism film(s) is investigated for incident light with different zenith and azimuth incident angles. A strong angle-dependent characteristic is found, even when the reflective recycling effect is available. To address this angle-dependent characteristic in a direct-lit LED backlight, a freeform lens is designed to deflect the light emitted from an LED into the incident angle range with high transmission efficiency. Two design examples are implemented by adopting dual- and single-layer prism film(s). The simulation results show that the freeform lens can enhance the on-axis luminance by 26% and 35%, respectively, while the viewing angle remains nearly unchanged. Furthermore, using a single layer of prism film, a 19-in. direct-lit LED backlight module is constructed for experimental verification. By fabricating the freeform lenses and adding them to the backlight module, the on-axis luminance is enhanced by 24%, and the viewing angle is decreased by no more than 2°. Finally, the influence of the diffusers, which causes the experimental results to degrade slightly compared with the simulation results, is analyzed. 相似文献
4.
Hanfeng Chen Junho Sung Taehyeun Ha Yungjun Park 《Journal of the Society for Information Display》2007,15(12):981-988
Abstract— The pixel brightness of an LCD panel perceived by a user is the product of the backlight brightness and the panel transmittance. In conventional LCD panels, the backlight brightness is constant and always at peak luminance. This design suffers from light leakage and power waste problems at dark scenes. This paper presents a new LCD system, which uses locally pixel‐compensated backlight dimming (PCBD). The proposed method combines backlight control and pixel processing for reducing light leakage and power consumption while keeping the image at the original brightness. Backlight luminance is dimmed locally in the dark‐image region, and pixel values are compensated synchronously according to the luminance profile of dimmed backlight. By reducing the light leakage, a static contrast of over 20,000:1 has been achieved on a large‐sized LCD panel with the proposed PCBD method. No obvious artifacts have been noticed as well. The power consumption of the panel can also be greatly reduced, depending on various video content. The PCBD method could be widely used for developing state‐of‐the‐art LCD panels with LED backlights. 相似文献
5.
6.
Abstract— A multistable liquid‐crystal device has been realized in this study; its smectic‐A LC is oriented by in‐plane and out‐of‐plane electric fields with various amplitudes. This paper introduces improvements made to electrode structure and hybrid surface treatments that have enhanced SmA LC device performance. The driving voltage of the hybrid‐aligned cell has been reduced to 20% of the vertical‐aligned one, and light leakage has been suppressed by out‐of‐plane electric‐field‐strength modulation. The many advantages of this multi‐stabilized LC device could be applied to memory devices and to flexible displays. 相似文献
7.
Seong‐Eun Kim Joo‐Young An Jong‐Ju Hong Tae Wook Lee Chang Gone Kim Woo‐Jin Song 《Journal of the Society for Information Display》2009,17(12):1051-1057
Abstract— In conventional LCDs, the backlight is set to maximum luminance regardless of the image. For dark scenes, this approach causes light leakage and power waste. Especially, light leakage in dark scenes degrades the contrast ratio of LCDs; to circumvent this problem, local‐dimming systems have been proposed. In these systems, the LED backlight is divided into several local blocks and the backlight luminance of each local block is controlled individually, and pixel values are adjusted simultaneously according to the luminance profile of the dimmed backlight. In this paper, a method of determining the LED backlight luminance of each local block depending on the image is proposed; this method significantly improves the image quality of LCDs. First, we introduce methods of quantifying light‐leakage at dark gray levels and clipping at bright gray levels. Then, the proposed method to determine the dimming duty, which controls the LED backlight luminance by compromising between these two measures, was derived. The proposed algorithm preserves the original image with little clipping distortion and effectively reduces light leakage. 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.
Randall Blanchard 《Journal of the Society for Information Display》2002,10(2):175-178
A high‐intensity backlight for use with large LCD panels has been developed. It supports the performance and environmental requirements of a display intended for outdoor applications. This backlight technology uses an inductively coupled electrodeless fluorescent lamp with a lifetime of 100,000 hours, instant starting at ?40°C and a stable light output over a temperature span of 70°C. The backlight design has been optimized for luminance uniformity and efficiency within a display depth of 6 in. A 21.3‐in. LCD monitor, using this backlight technology, provides an image brightness of 2000 cd/m2 from a single 150‐W lamp. 相似文献
10.
The paper investigates the impact of text and background color combinations on the legibility of text presented on LCDs. The legibility of 56 elementary color combinations was tested by 308 participants. The first task required the participants to identify 21 uppercase alphabetic characters selected and presented in conformance with a Snellen chart in various color combinations. For each color combination, the number of correctly identified characters was recorded as a visual performance measure. In the second task, participants subjectively rated the legibility of color combinations on a ten-point Likert scale. The results show that neither the Le Courier legibility table nor the CRT legibility table is appropriate for LCDs. A new legibility table is proposed for LCDs where the highest ranked are contrastive color combinations with positive polarity whereas for CRT displays, the highest ranked are contrastive color combinations with negative polarity. The findings of this study can be used to determine the best possible color combinations when developing content displayed on LCDs. 相似文献
11.
图形液晶显示模块在平衡机中的应用 总被引：1，自引：0，他引：1
介绍了图形点阵式液晶控制器SEDl335与MES96系列单片机TN80Cl96KCl6的硬件接口电路,详细说明了汉字和图形显示的软件设计,给出了液晶显示模块在平衡机中应用的实例。该测试设备中,采用图形点阵式液晶显示模块,硬件结构简单,软件易于维护和扩展,可实现交互式菜单显示和图并茂的人机界面效果。 相似文献
12.
Deng‐Ke Yang 《Journal of the Society for Information Display》2008,16(1):117-124
Abstract— In this paper the operational principle and performance of guest‐host, liquid‐crystal/polymer‐composite scattering, and cholesteric liquid‐crystal reflective displays are reviewed. These displays do not use polarizers and have the advantage of providing high reflectance and compatibility with flexible plastic substrates. 相似文献
13.
液晶驱动电路HT 1612及其在蒸汽流量积算器中的应用 总被引：1，自引：0，他引：1
The features and the basic operation method of
the HT1621 liquid crystal display driving circuit are introduced． With the steam flow to
talizer as example the design of relevant hardware and software for the application of
HT1621 in liquid crystal display ins truments is described in brief． 相似文献
14.
Li‐Wei Liu Qiong‐Hua Wang Jian‐Peng Cui 《Journal of the Society for Information Display》2011,19(8):547-550
Abstract— A continuous‐viewing‐angle‐controllable liquid‐crystal display (LCD) using a blue‐phase liquid crystal is proposed. To realize both wide‐viewing‐angle (WVA) mode and narrow‐viewing‐angle (NVA) mode with a single liquid‐crystal panel, each pixel is divided into a main pixel and a subpixel. The main pixel is for displaying images in both modes. The subpixel is for displaying images in WVA mode and controlling the viewing angle in NVA mode. The device exhibits a good viewing‐angle‐controlling characteristic and high transmittance. 相似文献
15.
TFT-LCD是目前主流的液晶显示技术,在对其驱动电路中核心的源驱动器工作原理进行分析的基础上,提出自己的设计方案,并对其中的gamma校正原理和输出缓冲电路进行分析。电路使用SMIC 0.35μm3.3V/18V工艺。 相似文献
16.
Computer simulation results on various mixed-mode twisted-nematic (MTN) cells for transmissive liquid crystal displays are presented. Twist angles ranging from 30 to 120° were investigated. These transmissive MTN cells are attractive for their low operation voltage and fast response time. 相似文献
17.
Li‐Wei Liu Jian‐Peng Cui Da‐Hai Li Qiong‐Hua Wang 《Journal of the Society for Information Display》2012,20(6):337-340
Abstract— A viewing‐angle‐controllable liquid‐crystal display (LCD) is proposed. When the device is only driven by an in‐plane electric field, it exhibits a wide‐viewing‐angle (WVA) mode. And it exhibits narrow‐viewing‐angle (NVA) mode when it is driven by a vertical electric field as well as an in‐plane electric field. In this manner, the viewing angle of the device can be controlled from 100° to 30°. The device exhibits a good viewing‐angle‐controlling characteristic and high transmittance. 相似文献
18.
T. Wilkinson S. Ward‐Foxton A. Menon W. H. Reeves S. E. Burns 《Journal of the Society for Information Display》2005,13(7):605-608
Abstract— In this paper, we present results from a new liquid crystal over plastic printed thin‐film‐transistor (TFT) display. The display demonstrator shows that the processing incompatibilities between the plastic TFT backplane and the liquid‐crystal materials can be addressed to make a stable twisted‐nematic structure. New fabrication processes such as the photo‐alignment of liquid crystals have made it possible to create a new generation of displays, which pave the way towards fully integrated plastic liquid‐crystal‐display technologies. 相似文献
19.
《Displays》2023
An adaptive local backlight dimming algorithm is proposed considering human visual sensitivities under various viewing conditions. Local dimming amount is maximized based on contrast sensitivity function and local image characteristics to minimize perceived luminance and contrast losses maintaining image qualities. Average luminance, contrast and spatial frequency are evaluated as local image characteristics. As dimming based on local characteristics has blocking artifacts, a compensation method using edge luminance difference is proposed considering human responses. The proposed algorithms reduce backlight power consumption by 39.69% on average, with an average SSIM of 0.995. It can be increased by 5.66% with varying viewing conditions, resulting in a 45.35% power consumption reduction on average. The outperformances of the proposed algorithm in power consumption reduction and maintaining image quality are verified with various image quality metrics compared to recent dimming algorithms. 相似文献
20.
Abstract— The high‐sensitivity pretilt‐angle measurement of liquid‐crystal displays, based on the modified crystal‐rotation configuration and the use of a common‐path heterodyne interferometer, is proposed. In this technique, environmental disturbance and surface reflection are eliminated to a large extend, thus providing advantages for both constructing a simple‐optics measurement system and achieving fast measurement with high accuracy and sensitivity. 相似文献