Search Results

The trend towards battery voltage vacuum fluorescent displays continues the technological advances in design and construction of VFD's, as they are applied to the automobile environment. With the ever increasing use of electronic displays for electronically tuned radios (ETR's), compact disc (CD) players, and other entertainment systems, advances in battery voltage displays and their associated drive circuitry have become a necessity. With the inherent advantages of low voltage operation and high information density, VFD's will continue to dominate the automobile audio markets. This paper will discuss battery voltage displays, the basic circuitry necessary to operate a vacuum fluorescent display, and comment on the “off the shelf” controller and driver circuitry available.

The front luminous vacuum fluorescent display (FLVFD) technology is a variation of the conventional vacuum fluorescent display technology. Having first been introduced into the consumer electronics market in 1983, FLVFD has seen increasing usage. FLVFD today offers improvements in the areas of visibility, viewing angle, package efficiency, operating temperature, and life. Although vacuum fluorescent displays have been utilized in automotive applications for more than ten years, the front luminous technology has not been used. The main reason for FLVFD's absence has been the highly reflective surface that the internal aluminum wiring forms on the front glass under direct sunlight conditions. This paper will discuss the studies and evaluations which have taken place to eliminate the reflection problem through the use of an optical multi-layer thin film process. This study assures the feasibility of using the FLVFD technology within the automotive environment.

Today, there are several kinds of display technologies used in the automobile. Of these technologies, the Vacuum Fluorescent Display has the following advantages: 1. Excellent readability under high ambient light conditions 2. High reliability under severe environmental conditions 3. Multicolor capability 4. Large glass size 5. Graphics flexibility As a result, the Vacuum Fluorescent Display technology is the major type of display technology used in the automobile application. A design trend in the industry is toward the use of graphic displays because of the need to display more information, and to reduce the cost and space factor. Until recently, vacuum fluorescent graphic displays of large area and high resolution had been limited by the lower brightness due to the low duty factor driving condition.

A Vacuum Fluorescent Display (VFD's) is widely accepted as a superior display device because of its impressive self-luminance and high reliability. VFD's for automotive applications have been used to convert signals to visual digital information. Now, in addition to digital style images, analog image displays are being requested for a wider choice of style. Furthermore, bright and clear display appearance and additional function are feasible by adopting the VFD technology to a pointer display application like mechanical speedometers or tachometers. This paper discusses the development of the large scale analog pointer image VFD for automotive use.

The adoption of the newly developed self-standing grid construction allows a more flexible layout of the electrodes and location of the grids, while reducing the number of grid leads. These improvements make it possible to minimize the lead pitch and to increase the flexibility of the lead out position. For example, the leads of the new clip-on type displays will allow them to be condensed on one side of the display, while in the case of the ordinary Vacuum Fluorescent Displays (VFDs) the leads are located on both the top and the bottom. By connecting flat cables to the minimized leads, a clip-on VFD was successfully developed, which is excellent in terms of mounting flexibility, circuit maintenance, system cost and function. The manufacturing process and features of the clip-on VFD will be described later.

The luminous efficiency of yellowish green and blue phosphor has been greatly improved. A luminance of 400 cd/m2 can be obtained at 12V with the yellowish green phosphor, whose luminance efficiency increased to 130%. This improvement suggests that the yellowish green phosphor can be used in the 12V driven VFD for the automotive application as well as greenish yellow and yellowish orange (1)*, (2)*. With respect to the blue phosphor, the luminance efficiency has been increased up to 160%, thus reducing the input power down to about 63%. By the continuing improvement, the blue phosphor will also be available in the 12V driven VFD.

Miniature Size Vacuum Fluorescent Displays for Automotive Radio Applications portray the application evolution and the technological advances necessary to develop displays for the automotive products. New VFD technological developments, including thin film and front luminous vacuum fluorescent displays, are outlined. Additionally, FLVFD operational parameters and drive circuitry available in the market are discussed.

Vacuum Fluorescent Displays have been manufactured for automotive applications for over six years. During this period, various technological advances, such as increased brightness, multicolors, and decreased power consumption have lead to the rapid expansion of the Vacuum Fluorescent Display (VFD) market. The following paper will discuss high brightness displays for automotive applications, focusing on large scale displays. These large scale displays are now becoming practical for mass production. We will discuss various design problems that are encountered and how to solve them; plus what performance criteria is targeted for future improvement.

Vacuum Fluorescent Displays (VFD's) for automotive Electronic Instrument Panels (EIP's) have been advancing in recent trends toward large scale systems. These systems offer the attractive appearance of large graphics, the flexibility of both analog and digital style images, and the cost reduction advantages of simpler power supplies, driving circuitry, and assembly procedures. A VFD consisting of all of the primary gages of an EIP was developed and mass produced. This paper will discuss this full size integrated cluster panel.

In 1976, Vacuum Fluorescent Displays (VFD) were first used for automotive clocks. Through various technical improvements, VFDs have contributed to the advancement of electronic instrument systems for automobiles. At present, VFDs are the most widely used display device for the automotive market. Current applications include message centers, audio systems, temperature control systems, clocks and Head Up Displays (HUD). This paper reports the technical improvements attained and implemented to date. Latest developments are also included.

The visual recognition of self-luminous displays in the automobile instrument panel under direct sunlight conditions is a major design criteria. The user-display interface requires the designer to consider factors of visibility, legibility, reading fatigue and styling. All factors are important, but under direct sunlight conditions, visibility has to take the highest priority and is the most important design factor. The object of this paper is to delineate visibility parameters by analyzing the results of experiments designed to determine the minimum brightness levels and type of filtering required to obtain visual recognition of vacuum fluorescent displays under the sunlight conditions.

Trend in Vacuum Fluorescent Displays relates to the technological advances in the design and construction of VFD's, with emphasis on recent and state of the art technology. Current design criteria plus operation parameters are outlined. Additionally, market demands on the display sector are noted with sections on both the displays of the present and future.

Ultra High Brightness Displays relates to the technological advancements preceding the development of the Jumbo TRON display screen. Additionally, subsequent developments and refinement of technologies are delineated, with emphasis on application oriented trends. Specifically, technological advancements contributing to the future advancement of vehicular information and communications are defined.

Vacuum Fluorescent Displays (VFDs) have been widely accepted for automotive applications in the U.S. and other countries because of their excellent performance capabilities such as high luminance, high reliability and low voltage operation. Recently, more compact and lightweight VFD packaging has been requested for use in limited-space applications and to achieve smaller overall system size, while concurrently pursuing a higher graphic-to-glass area ratio and maintaining VFD's excellent viewing angle capability. An Ultra Light Vacuum Fluorescent Display (UL VFD) has been developed to meet these challenges which has 14% thinner package thickness and 30% larger available graphic area compared to conventionally produced VFD. This paper discusses the development of UL VFD and its subsequent evaluation and testing.

Vacuum Fluorescent Displays (VFD's) are being used widely as the informational display panel in the automobile because they are a self-emissive, high luminance display device that feature crisp and easy-to-read images. This paper reports on the development of a VFD that can be directly driven by the outputs of a single chip microcomputer operating from a 12 volt supply. This system is most ideal for automotive applications.

Several types of Vacuum Fluorescent Displays (VFDs) are currently used for Head-Up Display (HUD) systems. To meet the requirements for HUDs which project the displayed information directly on the front windshield of a car, VFDs must be capable of displaying images at a luminance ten times greater than VFDs which are installed within the instrument panel. Since VFD technology was first selected for an automotive HUD system in 1988, the luminance improvement of the display has been the driving force in improving the system performance. Today's VFDs can generate extremely high luminance of 35,000cd/m2. This was developed through new innovations in materials and construction techniques. This paper discusses the development of an ultra-high luminance VFD for HUD system and its reliability.

Head-Up display (HUD) system for automobile is made possible by the recent development of the ultra high brightness vacuum fluorescent display (UHB-VFD). Co-planar technology is used to construct the UHB-VFD. The development of the VFD for automotive HUD will be discussed in this paper.

Vacuum Fluorescent Displays for Head Up Display (HUD) systems typically have a luminance of 20,000∼30,000 cd/m2. Certain HUD users have identified a need for a low cost HUD with a projected luminance of 10,000 cd/m2. We have studied an electrode structure modification with the objective of realizing a luminance of 10,000 cd/m2 at battery voltage, which will allow for a cost reduction of the HUD system.

The Vacuum Fluorescent Display (VFD), being a self-emissive display device featuring high luminance and excellent readability, has become widely used for automotive applications. The ability to drive it at 12V and to adjust the luminance with the duty cycle, give the VFD high consideration, especially for the display in the car audio system. The number of display segments for the car audio system has increased to more than 50. Adding new functions to the car audio system will increase the required number of display segments. In the 12V static drive system, the number of display segments determines, and equals, the number of driver integrated circuit (IC) output bits required. An increase in the number of anode terminals, required by the increase in display segments, will result in increases in system cost, assembly complexity, space-related problems, etc. This paper reports on attempts taken to solve these problems.