Development of a 32‐in. slim CRT with 125° deflection

Abstract— Today, CRT markets are being threatened by flat‐panel displays (FPDs) even though the screen quality of the CRT is one of the best of existing display devices. The depth of CRTs is one of its most important design factors to maintain its dominant position in the display market. Thus, a 32‐in.‐wide deflection‐angle 125° CRT (tube length of 360 mm) has been developed, and mass production began in January 2005. Wide deflection requires more advanced design of the major parts and reliable facilities in the production line. In this paper, new designs, mainly for deflection yokes and electron guns, will be introduced, which are considered the most difficult to design. These wide‐deflection CRTs attracted an extraordinary amount of attention even from end users in a variety of display shows last year and will help maintain the solid positions of CRTs in the coming era.     

Invited Paper: The evolution of projection displays: From mechanical scanners to microdisplays

Abstract— The development of electronic projection systems from its earliest days in the 1930s to the present will be reviewed. Early projection systems were dominated by cathode‐ray tubes (CRTs) and mechanical scanners (Scophony). Until the invention of the Eidophor oil‐film light‐valve (LV) projector in the 1940s, there was no all‐electronic alternative to CRTs. Oil‐film LVs and CRTs dominated projection until the introduction of the first liquid‐crystal‐device (LCD) light‐amplifier system by Hughes. Today, the oil‐film LV has vanished and the CRT is vanishing. The light amplifier has morphed into several variations of liquid crystal‐on‐silicon (LCoS). Mechanical scanners are starting to be re‐introduced for laser display systems. However, transmissive LCDs, the digital micromirror device (DMD), and LCoS microdisplays dominate the projection‐display market today. In addition to discussing the projection systems themselves, certain key component technologies that have made modern projection systems possible will be discussed.     

Study of the lifetime of phosphor screens formed via the settling and slurry methods under 7‐kV electron bombardment

Abstract— The lifetime of phosphor (ZnS:Ag,Cl) screens, excited by 7‐kV electron beams, which were formed via the settling method and the slurry method, respectively, were compared. The cathode‐ray tube (CRT) formed by using the settling method was found to have a better lifetime than that formed by the slurry method. Transmission electron microscopy (TEM) revealed that the phosphors were coated by a continuous glass film. Gas analysis showed a reduced emission for SO₂ gas from phosphors due to heating during the settling method as compared to the slurry method, indicating greater decomposition of ZnS by the slurry method. For low‐vacuum CRTs, the luminance degradation by electron irradiation was low for the settling method as compared to the slurry method. This indicates that the glass coating of the settling method produces a restraining effect on the decomposition of ZnS and prevents gas from attacking the phosphor surface, resulting in a better lifetime for the settling method.     

Magnetic ring for convergence improvement in CRTs with rectangular DY aperture

Abstract— In order to meet customer specifications, in CRT production it is common use to apply methods to improve the dynamic‐convergence performance. The dynamic‐convergence performance of CRTs can be improved by employing Magnetically Improved Color Alignment (MICA) technology. This involves the writing of the appropriate magnetic correction profile into a ring. The ring consists of hard‐magnetic ferrite particles embedded in polypropylene material and is inserted into the deflection yoke (DY) after the writing process is completed. MICA technology has been proven for a CRT with a rectangular DY aperture, 32‐in. WSRF (wide screen real flat) slim CRTs. MICA offers a good alternative to conventional dynamic‐convergence improvement methods such as spoilering and coil exchange.     

A study of the virtual screen image of flat-faced CRTs

Abstract— Simulation of a CRT with a flat outer surface and a spherical inner surface was performed to determine the virtual screen image made by refraction in the glass panel. The simulation calculated the radius of the panel inner surface for the flat-faced CRT to make a perfectly flat virtual screen image at each eye position. With H as the screen height, display-monitor CRTs used with eye positions closer than 1H show that the radius of the panel inner surface R = 18H is the most appropriate. On the other hand, for TV CRTs with a normal eye distance of 3H or greater, a radius of R = 40H or more is required to obtain a flat virtual image. The paper also clarifies the influence of panel glass thickness T on the distortion of the screen image.     

Color‐gamut expansion in CRTs

Abstract— This paper describes the architecture for a color picture tube (CPT), which enables a cost‐effective expansion of the color gamut. Besides a gamut expansion based on application of more‐saturated phosphors in the present three‐primary system, four‐ and five‐primary systems are described. Gun‐pitch modulation allows the application of a conventional electron gun for both a four‐ and five‐primary CRT. In these systems, the mask and matrix transmissions need to be reduced to maintain color purity. From this point of view, a five‐primary CRT is unrealistic. Two four‐primary CRTs are evaluated in more detail. But, here, the total anode current to generate white has to be increased substantially because of the reduced mask and matrix transmissions. Nonetheless, in this paper it is argued that with one of the four‐primary CRTs more‐saturated yellow colors can be displayed at 85% of the display luminance of a conventional system without loss of perceived sharpness.     

Arc perturbation theory of magnetic deflection

A perturbation theory is presented for deflection angles larger than 45°. Several parameters that previously had to be treated perturbatively are handled exactly. The theory can be used for a systematic study of front‐of‐screen errors in slim CRTs. First‐order results are presented and applied to a field configuration with a strongly varying dipole strength.     

A field‐emitter‐array cathode‐ray tube (FEA‐CRT)

Abstract— High‐resolution bright CRT monitors with Spindt‐type field‐emitter arrays (FEA‐CRTs) as electron guns have been realized for the first time. The FEA chip consists of 868 electron sources arranged within an emitter circle 50 μm in diameter and a vertical current limiter (VECTL) which protects the FEA chips from damage caused by an arc electric discharge. The FEA‐CRT has a minimum electron beam diameter of 0.84 mm at 18 kV and 100 μA.     

High‐deflection‐sensitivity CRTs with filled yoke

The trend towards slim CRTs requires deflection yokes (DYs) with an improved deflection sensitivity. We present a new method to improve the deflection sensitivity by 15–25% by filling the space between the ferrite core and deflection coils with a soft magnetic material. The effect was analyzed in terms of a simplified two‐dimensional model. These model calculations were confirmed by three‐dimensional simulations and by experiments on a DY design for the Philips 29‐in. Real Flat CRT.     

Advanced liquid‐crystal materials for TFT monitor and TV applications

Notebook applications have been one of the most important driving forces behind the remarkable growth of liquid‐crystal displays (LCDs). LCDs have recently been well accepted in the monitor market and large growth is forecasted because of the replacement of CRTs. The next challenge for LCDs is the TV market. These new application areas are supported by advanced LC technologies such as film‐compensated twisted nematic (TN), in‐plane switching (IPS), and vertically aligned (VA) modes. Each TFT technology requires a corresponding LC material improvement. We will review the recent liquid‐crystal material development for these advanced LC technologies.     

LCDs for TV applications

Abstract— Super IPS (S‐IPS) technology has intrinsic advantages in several aspects required for TV applications. Particularly, the wide‐viewing‐angle property and fast gray‐to‐gray response time of S‐IPS LCDs are both necessary requirements for family and individual use for LCD TVs. Given these benefits and other advantages S‐IPS provides, LG.Philips LCD has developed high‐performance S‐IPS LCDs for TV, which have now become competitive with plasma‐display panels (PDPs), in addition to other modes of LCD TVs as well as CRTs. This article will discuss why S‐IPS technology is the leading choice for LCD‐TV applications.     

Development of a high‐definition 32‐in. PDP

We developed the world's smallest‐profile 32‐in. HDTV PDP. By improving the luminous efficiency, a luminance of 650 cd/m² and power consumption (discharge and driving circuit) of 200 W or less was achieved. Moreover, incorporating an advanced color compensating (ACC) filter improved the PDP's color‐reproduction capability, better than that of CRTs.     

In‐field evaluation of the modulation transfer function and the signal‐to‐noise ratio of electronic‐display devices

Abstract— This paper describes a charged‐coupled device (CCD) camera, which was developed for in‐field evaluation of the image quality of electronic‐display devices [such as cathode‐ray tubes (CRTs) and liquid‐crystal displays (LCDs)] used for medical applications. Contrary to traditional cameras for display‐image‐quality evaluation, this CCD camera does not require a sophisticated x‐y‐z translation stage for mounting and adjustment. Instead, it is handheld and pressed by gentle pressure against the display screen. It is controlled by a software package which was originally developed for display calibration according to the DICOM 14 gray‐scale standard display function (GSDF). This software package controls the camera gain when measurements are made at different display luminance, display test patterns, performs image analysis and displays the results of the measurements and calculations. The work concentrated on the measurement of modulation transfer function (MTF) and of signal‐to‐noise ratio (SNR) per display pixel. The MTF is derived from the Fourier transform of the line spread function (LSF). The single‐display‐pixel SNR is derived from the integration of the noise power spectrum (NPS) of a camera image taken of a display with a uniform luminance. It is demonstrated that the device can produce repeatable results in terms of MTF and SNR. MTFs were measured on three monochrome CRTs and five monochrome LCDs in order to study repeatability and similar quantities. The MTF was measured on a 5‐Mpixel LCD yielding values that lie within 3.5% of the average MTF at the Nyquist frequency and 4.0% of the maximum total sharpness (∫ MTF² df). The MTF was also measured on a 9‐Mpixel LCD, yielding values that lie within 9.0% of the average MTF at the Nyquist frequency and 8.0% of the maximum total sharpness. The SNR was measured eight times on a 3‐Mpixel monochrome LCD at nine digital driving levels (DDLs). At a DDL of 185, the mean SNR was 15.694 and the standard deviation (Stdv) was 0.587. At a DDL of 65, the mean SNR was 5.675 and Stdv was 0.120.     

The performance of general-purpose colour CRT monitors in PACS environment

General-purpose colour cathode ray tube (CRT) monitors are used commonly for image display in personal computer-based picture archiving and communication system (PACS) and telemedicine systems. At present, however, we have not enough information about their performance or reliability for this task. Therefore, we studied the performance of five general-purpose colour CRTs and the changes in their performance in a year. Resolution was measured visually using original digital images. Maximum and minimum luminances were measured at the centre and periphery of the CRTs. Distortion was measured in the centre and periphery using original digital images. All the monitors met their specifications. The inhomogeneity of luminance exceeded 20% and varied across the CRTs. Darker monitors took more time to reach stable luminance levels. The corner brightness seemed to be a good estimator of both performance and distortion in colour monitors.     

Recent progress in device performance and picture quality of color plasma displays

This paper will describe the R&D history of color plasma displays (PDPs) at Pioneer. The goals of device performance for color PDPs compared to those of CRTs will be described. The device performance includes luminance, contrast ratio, resolution, gray scale, dynamic false contours, and image quality. In order to improve the device performance described above, the technologies developed by Pioneer will be described. These include T‐shaped electrode, WAFFLE rib structure, CLEAR driving method, and high‐quality video processing. Finally, the next generation of color PDPs will be described in terms of device performance and new technologies.     

Radical Product Innovations in SMEs: The Dominance of Entrepreneurial Orientation

The present study focuses on strategic factors underlying the adoption of radical product innovations in SMEs. It investigates whether market focus, technological posture and entrepreneurial orientation lead to the adoption of more radical product innovations. The study provides some new evidence on this issue drawing upon data collected from Greek SMEs in the food and beverages industry. More specifically, a logistic regression model is applied to analyse the choice between radical as against incremental product innovations. Empirical results appear to support the claim that it is mainly entrepreneurial orientation that favours the choice of radical product innovations. This suggests that in SMEs the notion of entrepreneurial‐push outweighs both market‐pull and technology‐push arguments. The findings are discussed in the context of Greece, taking into account the specific conditions prevailing. Apart from providing some new evidence in the important area of SMEs, they have also important implications for managers and policy‐makers. In addition, they encourage further theoretical and empirical investigation.     

Reading and skimming from computer screens and books: the paperless office revisited?

Past research has demonstrated that reading efficiency is lower from the standard computer displays of the 1980s than from paper. In the present experiments, subjects read or skimmed stories, sometimes from a high-quality CRT (cathode ray tube) and sometimes from a book. Skimming was 41% slower from the CRTs than from the book. Possible reasons for this finding are discussed. Reading speed and comprehension were equivalent for the high-quality CRTs and the book. The paperless office may be imminent after all.     

MTF measurement method for medical displays by using a bar‐pattern image

Abstract— A modulation‐transfer‐function (MTF) measurement method that uses a bar‐pattern image for medical displays such as liquid‐crystal displays (LCDs) and cathode‐ray tubes (CRTs) has been investigated. A specific bar‐pattern image on the display was acquired with a high‐resolution single‐lens reflex‐type digital camera equipped with a close‐up lens. The MTF was calculated from the amplitudes of the fundamental‐frequency components, which were extracted from the profile data across the bar patterns by using Fourier analysis. Actual comparisons with the conventional line technique were performed for a medical CRT. The adequate accuracy and excellent reproducibility of the method were confirmed. Furthermore, unlike the line method, an advantageous feature which can use an input signal with sufficient amplitude was theoretically proved. Horizontal and vertical MTFs at the central position of the display area were measured up to the Nyquist frequency for several medical displays. From these measurements, this method has the capability to detect slight differences between the displays measured. This proposed method is useful in understanding and quantifying the medical display's performance due to excellent reproducibility and accuracy.     

A Firm‐Level Analysis on the Relative Difference between Technology‐Driven and Market‐Driven Disruptive Business Model Innovations

Using the business model concept as a theoretical framework, this paper examines the relative disruptiveness potential between technology‐driven and market‐driven innovations. The study analyses retrospectively four case studies comprising two technologically sophisticated IT innovations and two technologically less sophisticated market‐driven innovations starting from their inception to the point of disruption over a period of 5–15 years. It finds that, while the disruption process of technology‐driven innovation conforms to the patterns predicted by disruptive innovation theory, the disruption process of market‐driven disruptive business model innovation depicts a bottleneck shape, where the positive effects of initial strategic choice, model specialization and investments on disruptiveness potential reach the maximum level and start to stagnate due to the same initial strategic choice and cost factors. Implications for researchers and practitioners are discussed.     

Noise estimation and reduction on five medical liquid‐crystal displays

Abstract— Liquid‐crystal displays (LCDs) are replacing cathode‐ray tube (CRT) displays as primary diagnostic viewing devices in clinics. They exhibit higher spatial noise than CRTs, which can interfere with diagnosis and reduce the efficiency especially when subtle abnormalities are presented. A study by the authors on LCD spatial noise has recently been reported. A high‐quality CCD camera was used to acquire images from the LCD. Noise properties were estimated from the digital‐camera images. Then, an error‐diffusion‐based operation was applied to reduce the display spatial noise. This paper presents the noise estimation and reduction results on five different medical‐grade LCDs using the same study protocol. These five different LCDs vary in terms of matrix size, pixel size, pixel structure, and vendors. The purpose of this work is to demonstrate that the LCD spatial‐noise estimation and reduction scheme proposed earlier by the authors is valid, robust, and necessary for various medicalgrade LCDs used in clinics today.