Several human cognitive studies have reported that color facilitates certain learning, memory and search tasks. Consideration of the color-opponent organization of human color vision and the spatial modulation transfer function for color suggests several simple sensory explanations.
Through the technique of laser optometry, measurements of a display user's visual accommodation and binocular convergence were used to assess the visual impact of display color, technology, contrast, and work time. The studies reported here indicate the potential of visual-function measurements as an objective means of improving the design of visual displays.
Designers of color displays have no simple means to relate suprathreshold color contrast to performance because few of the requisite experiments have been conducted. One of the obstacles has been the absence of a standardized and uniform method for representing color differences. A series of experiments was performed to explore and compare several candidate metrics. The results suggest that there may be no single metric which will be optimal for all applications. Further work will be needed to delineate the limitations of those considered thus far and to determine whether a single standard is feasible.
This paper reports some of the findings of a research program aimed at investigating the effects of digital image quality upon human performance. Two image quality dimensions, blur and noise, along with three display systems were studied by employing two human performance tasks. The results, in conjunction with the evaluation of enhancement/restoration techniques provide useful information for digital imaging system and subsystem designers.
From the early days of commercial television, as we know it today, the scientific community has been concerned with and continuously researched the display design requirements for acceptable presentation. Early research had emphasized the transmission bandwidth requirements, the number of raster lines per frame, the acceptability of and requirement for interlace to avoid flicker, and later the standards for color compatibility. For the most part this research was well done and led to acceptable criteria for the viewer of entertainment programming in the relaxed, nonintensive living room environment.
Contemporary problems in airborne displays may be traced to four primary factors. These factors are: (1) the rapid increase in our capability to collect and process large amounts of data, (2) requirements for increasingly precise information, (3) cockpit space restrictions, and (4) a diminishing gap between workload requirements and crew task load capabilities. Moreover, these factors are highly interrelated in that each seems to drive the others. Advances in reducing cockpit workload, for example, tend to be followed by requirements to perform new tasks to fill up the free time. Similarly, the less cockpit space that is available, the greater the need for information processing, and so on. The consequences of these factors, besides generating employment, have included the development of a wide range of technologies, each of which solves some problems while creating others.
Following the report of the breakthrough in the feasibility of practical application of Thin-Film Electroluminescent (TFEL) panels as solid state flat displays in 1974, a succession of efforts have been paid in the development of the production technologies of the panel, the implementation of the driver ICs of the panel, the assembling technique of the drive electronics, and what not; all aiming at the establishment of reliability and reproducibility.
The availability of flat-panel technology in commercial production quantities has made possible the design of very compact and lightweight personal computers. The electroluminescent technology display has several advantages that make it especially attractive for use in a compact computer.
The acceptance of electroluminescent (EL) panels into the next few generations of display systems and new display product areas has been gaining momentum for several years. Along with the delivery of this paper there are papers showing that panel and driver assemblies are in production and that the EL technology is ready for a commercial item. The driver technologies available today fill the need for portions of the marketplace, but they fall short of the promise we all have been pursuing. EL has the potential of high resolution, sunlight readable, hand-held, battery-powered and gray-shaded applications. The focus of this paper will be on the panel characteristics from the multiplex drive point of view, the achievements of the present driver system, the problems encountered while implementing the next generation of drivers, and what the future may hold.
Thin film electroluminescent devices made from ZnS:Mn can be designed to exhibit an inherent hysteresis in the luminance versus applied voltage characteristics. This memory behavior offers attractive advantages for efficient operation of displays with very large information content. Additionally, such memory devices can also be switched by light or electron beams, making possible such applications as image storage and a CRT with an active faceplate. In view of its importance, the hysteresis phenomenon will be reviewed from both an experimental and a theoretical point of view. The switching characteristics of memory devices and some of the empirical requirements for observing the hysteretic behavior will be described. This background will then be used to discuss the ac device operation in terms of a phenomenological model which accounts for the necessary negative resistance required for the bistability of a microscopic region termed a filament. The observed voltage range for hysteresis in the device can then be explained as an ensemble effect since most of the emitted light comes from a dense array of localized filaments. Finally, some technological difficulties associated with memory devices will be illustrated by choosing the recent electroluminescent storage CRT as an example of a particularly demanding implementation.
Fabrication issues for EL display panels with viewing areas of one meter square or larger are discussed. Considerations regarding choice of deposition technology, the nature of the deposition environment, and preferred types of equipment are presented. The analysis is supported by data on smaller matrix EL devices. Requirements on the layout and physical characteristics of electrode structures are specified as determined by computer models and experimental data, The question of resolution is addressed from the points of view of display fabrication and electronic drive, requirements. Operating parameters to be expected from the displays are predicted.
While considerable work has been done in developing monochrome AC thin-film electro-luminescent (TFEL) displays, primarily using yellow-emitting ZnS:Mn, recent work with green-emitting ZnS:TbF3 offers a second bright color. There is also growing need for and interest in an EL panel incorporating more than one color for visual pattern contrast. Since both of these phosphors and the insulators are transparent thin films, a multiple stack construction was selected, using transparent electrodes. Such panels with rudimentary fixed patterns were successfully fabricated and demonstrated as a feasibility study of the stacked construction and evaluation of the color compatibility of these two phosphors in a single display.
Seven homologous series of 4-n-alkylphenyl 4'-(trans-5-n-alkyl-l,3-dioxan-2-yl) benzoates and twenty five isomeric 4-(trans-5-n-alkyl-l,3-dioxan-2-yl) phenyl 4'-n-alkylbenzoates have been synthesized, both R and R' being normal alkyl groups from C2 to C8.
The performance of the thermally addressed dye switching liquid crystal display is discussed with emphasis on the applications as a CRT replacement. Topics presented include the optical performance, the trade off between contrast and brightness, the writing rate limitations, and some display design considerations for performance enhancement.
A few years back, the Guest-host (dichroic) display received a great deal of attention at conferences and in the literature. However, more recently the number of Guest-host papers seems to have decreased. The Guest-host display attracted interest because of its promises of high brightness, wide viewing angle, color contrast, high reliability, and low cost when compared to a conventional twisted nematic (TN) LCD. Today, the Guest-host display has yet to make significant market inroads against the TN-LCD. Is the Guest-host display ready for applications? What is the state-of-the-art? Who is manufacturing the dichroic LCD? A critical evaluation of this technology will be presented from an applications engineering perspective. Performance, cost and reliability data will he included along with a survey of products in which this display is now found. A competitive comparison will also be made between the TN and Guest-host LCDs. Finally, the author will present his views on the expectations for the future of this technology.
A multi-compartment cell technique has been developed for producing light field dichroic liquid crystal displays. Dichroic displays are well suited for presenting information to large audiences because of the low power and low voltage requirements, wide viewing angle and improved contrast under high ambient lighting conditions. The viewability of this display is greatly enhanced by the light field format. The multi-compartment cell technique also improves the structural integrity of the display cell and offers a significant reduction in processing cost.
A recent application of magneto optic technology to the development of magnetically switched light valves has resulted in devices satisfying many of the characteristics desired for real-time display and optical processing systems. Evaluation of prototype Units has shown the material to be well behaved exhibiting excellent uniformity and readily engineered into devices suitable for numerous applications. The fabrication processes, being similar to those currently employed by the semiconductor industry, are expected to result in high quality, high yield, and reliability and low cost. As a result, the future use of these devices appears to be almost unlimited.
Plasma displays use the physical phenomena of the as discharge aria are frequently called as discharge displays. Tnis is a rather mature display technology that teas seen commercial success over a wide size range, from small single digits to one meter diagonal graphics displays having 2 million pixels. Plasma displays currently enjoy the dominant position in large flat panel display tecnnologies. They are likely to maintain that position in at least the next five years because of the many properties of tne as discharge ideally suited for flat panel matrix displays.
The AC plasma display/memory panel provides com-pact size and low visual stress because of image quality and absence of flicker. Still, the contrast is often too high in normal room ambient and the color not the preferred. There is in addition an internal back-reflection which causes some annoyance in certain ambient lightings. These three items can be improved upon as described below
In October of 1981, Photonics Technology Inc., Luckey, Ohio and Magnavox Electronic Sys-tems Company, Fort Wayne, Indiana introduced a tactical display terminal featuring the world's largest, fully-populated, non-projected display: a one meter AC gas discharge (plasma) display panel with an active display area of 5.3 square feet, a resolution of over 400 light emitting picture elements (pixels) per square centimeter and a total of about 2,000,000 pixels. This display is directed to a U.S. military requirement existing for over a decade. Photonics is presently developing larger displays beyond the meter display up to 3 meters diagonal. High resolution displays with and without transparency. have also been developed. Multi-color displays (red, blue, white, green) with and without filters will be available by 1984. MicrospacerTM panels are presently available with less than 0.001% inoperative pixels, a total of less than 40 in a 2048 by 2048 display. The military display terminal of the 1980's will feature a non-projected, fully-populated, multi-color, flat display with less than 0.001% inoperative pixels, a resolution of 400 to 4000 pixels per square centimeter, and a diagonal of 0.5 to 3.0 meters.
Nuclear phenomena and their effects on various kinds of displays and their associated electronic circuits are described. Techniques for hardening display systems, and experience in developing the first nuclear-hardened large area plasma display for military tactical use are discussed.
The emergence of FCC Docket 20,780 and the October 1, 1983 compliance requirement is currently presenting design constraints on CRT Terminal vendors within the computer industry. We discussed the technical and marketing implications of FCC Docket 20,780 relative to the CRT Terminal vendor community and presented one technical approach that will assist vendors in meeting the EMI shielding requirement. The use of transparent conductive coatings on bonded glass panels in concert with antireflective coatings and contrast enhancement filters is one approach that was discussed, in case history format.
Digital technology is having a profound influence on many aspects of human activity. It certainly has affected all areas of television broadcasting. A monitor is probably the least affected by digital technology. In the present experimental coder/decoder units for either RGB or standard (NTSC, PAL or SECAM) signals, the monitor receives an analog signal, even in an all digital studio. The same is true for computer graphics and game systems. But, it is logical to expect technological changes in broadcast and computer monitor applications.
Higher resolution, wider video bandwidth, and flicker free are the features that users of color TV monitors want most. Color stability and raster stability also rank high on the list of desired features. For the past four years, the authors' company has been the technical leader for such displays - providing 50 kHz line rates for 1024x768 pixel with 60 Hz refresh (well above the eye's critical flicker frequency) color displays for military systems. Other manufacturers have attempted to meet the flicker-free requirement by using long persistence phosphors which tend to reduce the effective resolution of dynamically moving images. Now monitor users are requiring 64 kHz line rates, and greater than 100 MHz video bandwidth for even higher resolution 1024x1024 pixel, 60 Hz refresh, flicker-free color displays capable of displaying moving images. Added to these requirements is the desire for lower cost and lower power. This paper describes how these conflicting desires are being provided in the SRL Model 2110 Flicker-Free Color TV Display. Also included is a discussion on improved image geometry and the heretofore unheard of video bandwidth of greater than 100 MHz (capable of supporting greater than 200 million pixels per second) at usable brightness levels.
A number of large screen display technologies are suitable for use in Military C3 systems. Techniques applicable to large screen display systems include projection cathode ray tubes, light valves and large area direct view flat-panel devices. The operational characteristics, information on existing product line equipment and a description of new large screen devices, which are just entering the market or are in an advanced state of development, are presented herein. This material is based upon the results of a survey of manufacturers of large screen display equipment for military and commercial applications. It has been augmented by on-site discussions with cognizant engineering personnel and marketing managers. Improvements to existing equipment, cost information (both initial and operating), and new technological advances in the field over the last five years are highlighted.
Wider and brighter are key words when describing the wants of users of projection television (TV). Higher resolution and truer colors also rank high on the list of desirable features. In aircraft flight simulators, there is the need for static, and sometimes dynamic, raster shaping for off-axis projection on large dome screens. To top off these conflicting requirements is the need for time shared calligraphic (stroke writing or vector refresh) and raster TV operation in some computer image generation systems. This paper describes some of the concepts being investigated for such a cathode ray tube (CRT) projector. Problems associated with optics, color convergence, cooling of the CRT faceplates and deflection are discussed. In addition, the problems associated with the side-by-side merging of multiple projectors for very wide field of view projection (Videorama) are addressed.
Question - How does Westinghouse make a cathode ray tube with the level of screen quality required by today's high performance systems. Answer - Very carefully! Thirty years ago in the heyday of the monochrome CRT for TV application, the quality levels for 21" tubes allowed 30 mil and even 40 mil blemishes. The resolution of the system and the application did not require any more. Even with these quality standards we had difficulty making very high yields. In recent years the performance of our CRTs in military and commercial systems has been regularly improved to maintain contact with the needs of our customers. We are no longer dealing with a display of 300 TV lines as was common in early commercial TV. Today our products are capable of 4000 line resolution (slightly less than 1 mil spot size for a 4" raster). These tubes are used in a stroke application. They also meet requirements such as uniform brightness and peak brightness which were not needed a few years ago.
This paper discusses some systems applications of plasma panel displays in military command, control, communication and intelligence (C3I) systems. The potential lethality and rapid pace of warfare on the modern battlefield make positive command and control of our armed forces more critical than ever. This gives rise to the need for highly mobile, user-friendly, automatic data processing systems which are able to survive extreme environments. The user is relatively unsophisticated, is unfamiliar with computer programing and is required to both operate the system and provide maintenance under highly stressful conditions. The plasma display, used in conjunction with a state-of-the-art micro-processor-based automatic data processing system, has a number of characteristics which make it particularly suitable as a man-machine interface to be used in tactical C3I equip-ment in the modern Army. A number of factors must be taken into consideration in the design of plasma displays so that they will be able not only to withstand the severe tactical environment to which they are exposed, but also to provide a user-friendly interface. Specific examples of tactical operational Army systems utilizing plasma displays of various sizes are discussed.