Small Display Devices Research Articles

Design of freeform surface optical component in helmet mounted display

Helmet display (HMD) is the core hardware of virtual display technology. It is a small display device mounted on the helmet to produce visual images for the user. The MHD system mainly consists of an image source, optical, and support system. Still, the traditional optical subsystem cannot achieve the functions of the ideal optical system, such as being light-weight, small in size, and having an extensive field angle. This paper established the proper initial model, and the optimal control conditions and surface upgrade strategy were determined. Herein, the design scheme of the free-form prism with good performance was obtained. We solve the feature of large volume and complicated structure of optical components of helmet display and describe the design idea of free-form prism in detail. In this paper, the system resolution we designed is 800 × 600, the Modulation transfer function (MTF) value of the prism is more significant than 0.1 at the spatial resolution of 30lp/mm, and the distortion is less than 5%. The exit pupil diameter of the system is 8mm, and the field angle is 26°×20°.

M-Tree based on the Fly Automatic Webpage Adaptation for Small Display Device

Due to the large growth of the electronics industries, the aggregate number of mobile users are increased side by side the content available in the internet also grown hugely. In this paper we are coming up with a strategy which converts the existing websites into mobile site automatically. in the current newly coming websites are developed using the css frameworks like bootstrap, html boil plates etc., but the previously developed websites are to be totally reconstructing to fit in the small displays. We propose a tree structure based automatic web page adaptation for small display devices. These is mining the webpage content and generate a D-tree taking into account of the content present in the webpage and using the M-Tree and construct the new SM-tree which has to be optimized data which is need for the small display devices alone. Using the latest css framework called Google material framework that m-tree is automatically convert the html pages. The multimedia contents like images and videos have compressed based on the client device configuration. This result in reducing the webpage loading time in mobile device and also cut the cost in revamping the old websites.

Image Adaptation and Dynamic Browsing Based on Two-Layer Saliency Combination

In recent years, image adaptation has attracted more and more attention during the evolution of the integration of broadcasting, Internet and telecommunications. The diversity of display devices requires images to be resized for optimal display on different terminals. In this paper, an image adaptation scheme and a dynamic browsing strategy are proposed, which are based on the visual attention model (VAM) with two-layer saliency optimization. First, a VAM is constructed by optimizing the image saliency according to the global and local layers by simulated annealing and the saliency of focus of attention (FOA) can be ranked by the obtained saliency map. Then an image adaptation scheme is designed based on the obtained saliency map. In the proposed adaptation scheme, each predominant FOA is modeled as a rectangular region, and the image is adjusted corresponding to the display terminal and the rank of FOA. Based on the principle of global features precedence, a dynamic browsing strategy is developed for browsing large images on small display devices. Experiments on saliency map show that the cross-layer saliency detection algorithm has advantages on detecting salient regions accurately and reflecting the shift of FOA implicitly, which are useful for image adaptation. In addition, subjective evaluation experiments demonstrate the proposed image adaptation scheme and dynamic browsing strategy are feasible and have promising applications in practice.

Updating Fitts' Law to Account for Small Targets

The use of small display devices is becoming more prevalent in our daily lives, such as smart phones, ultramobile PCs, and even head-mounted displays. Usually, the graphical user interface components shown on these displays are small and often difficult to interact with. Although some prior work has shown that Fitts' law does not hold for small target size, a detailed investigation of Fitts' law in different small target size conditions has yet to be done. In this study we conducted two experiments investigating the impact of small target sizes on pointing performance. We identified a critical point on the target size dimension where Fitts' law started to break down. We then proposed a small target size index of difficulty and an empirical Fitts' formula to extend the Fitts' law beyond the critical point to small target size conditions. Our results show that the new model works well as both a descriptive and a predictive model for small target size conditions.

DCT 변환 계수를 이용한 축소/확대

High quality image processing schemes are used more widely than ever according to the development of various visual media. We need a compressed form of image for sending more capacity and a controlling strategy of images for small display devices. In this paper, we propose an image upsampling and downsamplig scheme using DCT coefficients for those purposes. Our scheme is designed to control the size of picture based on the target display media by reducing the data in DCT domain while not increasing the computational burdens. With the power of controlling the resolution in DCT domain, the proposed method shows higher PSNR than other competing methods in experiment.

Piles across space: Breaking the real-estate barrier on small-display devices

We describe an implementation that has users ‘flick’ notes, images, audio, and video files onto virtual, imaginary piles beyond the display of small-screen devices. Multiple sets of piles can be maintained in persistent workspaces. Two user studies yielded the following: Participants developed mental schemes to remember virtual pile locations, and they successfully reinstated pile locations after several days, while situated in varying environments. Alignment of visual cues on screen with surrounding physical cues in situ accelerated a sorting task when compared to other, non-aligned visual cues. The latter, however, yielded better long-term retention.

Effective search results summary size and device screen size: Is there a relationship?

In recent years, small screen devices have seen widespread increase in their acceptance and use. Combining mobility with increased technological advances many such devices can now be considered mobile information terminals. However, user interactions with small display devices remain a challenge due to the inherent input restrictions and limited display capabilities. These challenges are particularly evident for tasks, such as information seeking. For the presentation of retrieval results we consider that a personalised and context dependent approach could offer benefits, particularly for retrieving information in a non-traditional environment. As a starting point, in this paper we report an investigation into the effects of summary length as a function of screen size, where query-biased summaries are used to present retrieval results. Following a brief description of our proposed system, we report a user study aimed at exploring whether there is an optimal summary size for three types of device (smartphone, PDA and laptop), given their different screen sizes.

Using large tables on small display devices

The next evolutionary step in wireless Internet information management is to provide support for tasks, which may be collaborative and may include multiple target devices, from desktop to handheld. This means that the information architecture supports the processes of the task, recognizes group interaction, and lets users migrate seamlessly among internet-compatible devices without losing the thread of the session. If users are free to migrate amongst devices during the course of a session then intelligent transformation of data is required to exploit the screen size and input characteristics of the target appliance with minimal loss of task effectiveness. In this paper we first review general characteristics related to the performance of users on small screens and then examine the navigation of full tables on small screens for users in multi-device scenarios. We examine the methodologies available for access to full tables in environments where the full table cannot be viewed in its entirety. In particular, we examine the situation where users are collaborating across platform and referring to the same table of data. We ask three basic questions: Does screen size affect the performance of table lookup tasks? Does a search function improve performance of table lookup based tasks on reduced screen sizes? Does including context information improve the performance of table lookup based tasks on reduced screen sizes? The answers to these questions are important as individual and intuitive responses are used by the designers of small screen interfaces for use with large tables of data. We report on the results of a user study that examines factors that may affect the use of large tables on small display devices. The use of large tables on small devices in their native state becomes important in at least two circumstances. First, when collaboration involves two or more users sharing a view of data when the individual screen sizes are different. Second, when the exact table structure replication may be critical as a user moves quickly from a larger to a smaller screen or back again mid-task. Performance is measured by both effectiveness, correctness of result, and efficiency, effort to reach a result.

主観評価実験によるＭＰＥＧ‐４低ビットレート小画面符号化画像のパラメータ検討

In the case of very low bit-rate video coding such as MPEG-4 for small display devices, the encoding parameters of the image size and the frame rate must be set appropriately. Although a subjective quality evaluation is necessary for judging the image quality, a method for evaluating small image display systems has not been developed yet. We propose a new subjective method for evaluating the quality of such systems, and we study the encoding parameters. First, we extract two psychological factors : “image quality” and “continuity”. Next, we verify that the overall evaluation can be expressed by a linear combination of evaluation scores of the two extracted psychological factors, and that the results of the overall evaluation provide useful guidelines for setting the encoding system parameters. We show that the results for QSIF size tend to be better than those for SIF size for the same bit-rate.

소형 화면 단말기를 위한 웹 문서 변환 기법

We propose a web document transcoding technique that translates existing web pages designed for desktop computers into an appropriate form for hand-held devices connected to the wireless internet. By defining a content block based on a visual separation and using it as a minimum unit for analyzing and converting processes, we can get web pages converted more exactly. We also apply the reallocation of the content block and the generation of new index in order to provide convenient interface without left-right scrolling in small screen devices. These methods, compared with existing ways such as text level summary or partial extraction method, can provide efficient navigation and a full recognition of web documents. To gain those transcoding benefits, we propose the Layout-Forming Tag Analysis Algorithm that analyzes structural tags, which motivate visual separation and the Component Grouping Algorithm that extracts the content block. We also classify and rearrange the content block and generate the new index to produce an appropriate form of web pages for small display devices. We have designed and implemented our transcoding system in a proxy server and evaluated the methods and the algorithms through an analysis of transcoded results. Our transcoding system showed a good result on most of popular web pages that have complicated structures.

Variable‐hue light‐emitting diode using a single crystal chip

AbstractMonochromatic light‐emitting diodes of different sizes and colors are widely used as small display devices. However, diodes of different colors for commercial purposes are those having a combination of red light‐emitting pellets and green light‐emitting pellets. Such a combination involves problems of color uniformity and brightness degradation. Therefore, a single pellet which has different uniform colors was proposed several years ago, but it has not yet been marketed due to many technical difficulties. The authors succeeded in making a single pellet with a green light‐emitting part and a red light‐emitting part on both sides of a GaP substrate. By changing the current ratio of the current flowing through the device, different colors were attained. This paper deals with different technical problems associated with device fabrication and the solutions to these problems. Also, electrical and optical properties of the device are discussed.