Measuring the degree of eyestrain caused by watching LCD and PDP devices

In this paper, we propose a new way of measuring the degree of eyestrain caused by watching LCD (Liquid Crystal Display) and PDP (Plasma Display Panel) devices. In the experiments, we used a head-mounted eye capturing device and an illumination setup that was designed to avoid specular reflections caused by glasses or contact lenses. Using the captured eye images, we analyzed the eye blinking and changes of pupil sizes (pupil accommodation), using a real-time image processing algorithm. Then we analyzed the degree of eyestrain based on the calculated blinking rate and the pupil accommodation speed. The proposed method offers five improvements over previous methods. First, we perform a comparative analysis of LCD and PDP devices based on the degree of eyestrain. Second, to analyze the degree of eyestrain, we use quantitative data such as the blinking rate and the pupil accommodation speed. Third, we measure the accurate eye blinking and changes of pupil sizes by using high-resolution and zoomed eye image sequences. Fourth, since the camera and illuminative system are based on a specular reflective model, the proposed method can be used with subjects that wear glasses or contact lenses. Fifth, the proposed method is performed at real-time speed.Experimental results showed that the degree of eyestrain when watching LCD devices was greater than that when watching PDP devices.

Relevance to industry

In the large display industry, LCD and PDP devices have become more and more prevalent. In the past, LCD devices have been compared to PDP devices in terms of factors such as spatial resolution, brightness, contrast levels, etc. To perform more accurate comparisons based on human factor, we are proposing a new way of comparing LCD to PDP devices based on the degree of eyestrain.     

虚拟LCD显示模块的设计

通过在BTF020单片机的RAM中建立缓冲区数组并对虚拟LCD的显示数据进行存储,然后通过单片机的串口将该数据传送给PC机,再用VB6.0语言对这些数据进行处理并构建虚拟LCD的界面,使其能够正确显示字符或者图形。实验结果表明,所建的虚拟LCD显示模块具有开发简便、快速、通用性强的特点。     

新型高分辨率LCD控制器的设计与实现

为了解决ARM等嵌入式处理器驱动大屏幕LCD困难的问题,提出了一种基于FPGA的大屏幕LCD控制器解决方案.该控制器通过搭建合理的架构设计及巧妙的总线仲裁机制,解决了大屏幕显示所需的高刷新率和高更新率问题.同时,多个内部寄存器使其支持各种型号的LCD显示器,并成功地驱动了15英寸的LCD显示器.     

Characterisation of a desktop LCD projector

A typical desktop LCD projector was characterised. Having determined the optimum settings of the brightness and contrast controls, measurements were made with a spectroradiometer to establish the additivity of the primaries, inter-channel dependence, colour gamut, tone scale, contrast, spatial non-uniformity, temporal stability and viewing angle variation. Four mathematical models were compared for their accuracy in predicting the colours generated by the display for arbitrary signal inputs. A new model was developed for the S-shaped electro-optical transfer function of the LCD device, and was extended to predict the anomalous colour tracking of the primaries.     

CRT and LCD monitor and process materials evaluated for environmental improvement

Decision rules have been developed and applied to the bills of materials of a color cathode‐ray tube (CRT) and a liquid‐crystal‐display (LCD) desktop monitor to determine which product and process materials will be evaluated in an environmental life‐cycle assessment. Materials of significant mass, of technological importance, and of potential environmental impact are targeted. The list of materials identified are those for which life‐cycle inventory data will be obtained for the materials extraction and materials processing life‐cycle stages of a CRT and an LCD. Additionally, materials identified will also be used to represent life‐cycle impact in terms of resource consumption, as well as surrogates for occupational health impacts.     

Linux内核的嵌入式系统裁减以及LCD驱动的实现

本文主要描述了如何将linux2.6的内核裁减为嵌入式Linux系统的过程,并在S3C2410开发板上移植了嵌入式Linux 2.6.11.7内核系统,并说明了如何进行LCD驱动程序模块化编程及如何将驱动程序静态加载到系统内核之中。     

嵌入式网络图文显示控制器设计

通过以太网显示图文信息到分布式场地的需求,近些年的呈明显上升趋势,越来越广泛的应用到市场当中,如交通,车站,学校等场所。该文设计了基于linux的网络的图文监视控制器,以S1D13506显示控制芯片和网络控制芯片为线索,以驱动程序设计为方法,详细介绍了系统的硬件结构和软件实现,另图文显示方式提出了一个新的思路和手段。该文的创新点在于：基于网络实现了远程屏幕的控制与显示,具有一定的市场应用价值。     

Motion‐blur characterization on liquid‐crystal displays

Abstract— In this paper, several methods to characterize motion blur on liquid‐crystal displays are reviewed. Based on the assumptions of smooth‐pursuit eye tracking and one‐frame temporal luminance integration, a simple algorithm has been proposed to calculate the normalized blurred edge width (N‐BEW) and motion‐picture response time (MPRT) with a one‐frame‐time moving‐window function to LC temporal step response curves. A custom measurement system with a fast‐eye‐sensitivity‐compensated photodiode has been developed to characterize motion blur based on LC response curves (LCRCs). MPRT values obtained by using the algorithm mentioned above and those from the smooth‐pursuit‐camera methods agree. Perception experiments were conducted to validate the correspondence between the simulated results and actual perceived images by the human eyes. In addition, the insufficiency of MPRT to evaluate motion blur on impulse‐type light‐generation LCDs, by analyzing the measurement results of a scanning backlight LCD, is discussed.     

Power savings and enhancement of gray‐scale capability of LCD TVs with an adaptive dimming technique

Abstract— The luminance of a backlight unit for an LCD TV is adaptively and locally dimmed along with the input video signal in order to reduce the power consumption and also to improve the picture quality. By adopting the zero‐dimensional (0D), 1D, and 2D adaptive dimming techniques, a sample movie having 8.0% post‐gamma average picture levels (APL) could be displayed using 83%, 71%, and 50% of the original backlight power, respectively. For an adoption of the 2D dimming, an LED backlight is preferable. The adaptive‐dimming technique also allows the differential aging characteristics between the LED components and temperature dependence of color and luminance to be overcome. From simulations of a reduction in power consumption, it was found that 40 × 40 pixels is a unit of the local dimming, 30 frames for the sampling period, 24 dimming steps, and an equal‐signal‐step method for determining the dimming factor have been found to be appropriate. The gray‐scale capability of low‐luminance images can also be improved by dimming the backlight luminance and expanding the input signal. By using an LCD TV having an 8‐bit capability, an 11‐bit‐equivalent gray‐scale expression was experimentally proven.     

Characterizing displays by their temporal aperture: A theoretical framework

Abstract— The spatio‐temporal aperture and sample rate of a video display determines both the static and dynamic resolution of the video signal that is rendered. The dynamic display characteristics like the visibility of large‐area flicker, motion judder, and motion blur can be derived from the frame rate and the temporal extent of the pixel aperture (i.e., the temporal aperture). For example, liquid‐crystal displays (LCDs) have an aperture that is relatively small in the spatial dimension and wide in the temporal domain. Consequently, moving objects displayed on an LCD suffer from motion blur. Especially in TV applications, the temporal dimension has a large impact on the overall picture quality. The temporal aperture, together with the frame rate, is shown to predict the amount of perceived large‐area flicker, motion judder, and motion blur and also the performance of motion‐blur reduction algorithms for LCDs. From this analysis it is further determined how to obtain the optimal temporal aperture of a television display, for which not only properties of the human visual system (HVS), but also the properties of the video signal have to be taken into account.