摘要:

Abstract—The physical origin of the edge spot width on CRT screens with self‐converging and anastigmatic deflection yokes is discussed. The discussion is supported with graphical data from a new simulation prog

ISSN:1071-0922    

DOI:10.1889/1.1984888

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—A simulator for electron beams of CRTs with axi‐asymmetric electron guns was developed, taking into account space‐charge effects, thermal spreads of electrons, and deflection‐defocusing effects. In the simulator, the electron beam is divided into Gaussian beamlets, each having a main trajectory and paraxial trajectories surrounding it. For the calculation of the electrostatic field in the main lens, the multipole field‐expansion method was used in combination with the surface‐charge method to reduce CPU time and simplify data input for complicated electrodes. The dynamic astigmatism correction, accomplished by placing a quadrupole lens in the main lens, and the cancellation of astigmatism by using slits and square apertures in the beam‐forming region were investigated. Calculated beam‐spot diameters agreed well with measurements (differences were at most about 10%). The simulator was confirmed to be effective for investigating and designing axi‐asymmetric elect

ISSN:1071-0922    

DOI:10.1889/1.1984889

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—Four‐point bend strength of samples of CRT panel glass was measured following sandblast, gritblast, and 150‐J abrasions, after either a 48‐hour soak in air or a 24‐hour soak in water. Strength/flaw characteristics were determined by examining the fracture surface and relating strength to flaw depth and mirror radius. Fracture toughness was also measured. Based on the strength and the fracture toughness values, the flaw shape factor or flaw severity for each type of abrasion was c

ISSN:1071-0922    

DOI:10.1889/1.1984890

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—This investigation determined the error associated with colour reproduction when different light meters were used to characterize a CRT. Luminance measurements were taken with three light‐measuring instruments to produce gamma tables. The tables were used to calibrate 28 colours. Results showed that the most acceptable instrument was one that accurately measured light below 0.001 cd/m2and that used colour‐matching tables to weight the radiant energy. Less‐sensitive instruments that used fixed filters to model the colour‐matching functions produced colours that were perceptibly different from the specified colours. The reproduction errors were evaluated against colour discrimination thresholds and ΔE*. If accurate reproduction of luminance is not essential, a less‐sensitive instrument with a cutoff of 0.01 cd/m2and three separate filters for modeling the colour‐matching functions may be adequate. Complete gamma‐correction tables (voltage input/luminance output) for each gun were not necessary. Accurate colour calibration can be based on a limited number of luminance measurements plus an interpolation procedure to determine the intervening values in the gamma tables. The reliability of the initial characterization was tested after an interval of 9 months. The maximum luminance of the monitor decreased considerably over this time period. A simple recalibration method, outlined by Lucassen and Walraven (Ref. 1) was effective in restoring luminance accuracy. This method allows for periodic adjustments to the luminance output on a CRT using a small number

ISSN:1071-0922    

DOI:10.1889/1.1984891

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—Direct‐current powder electroluminescent (DCPEL) display devices were excited by unipolar voltage pulses, and current flow through the phosphor was recorded. Devices with different formed layer thicknesses were obtained by varying the forming voltage. For a fixed electric field in the formed layer, the phosphor current did not show a substantial increase as the thickness of the formed layer increased. A model is proposed in which tunnel injection from the p‐Cu2S/i‐ZnS:Mn interface of a reverse‐biased p‐Cu2S/i‐ZnS:Mn/n‐SnO2structure is thought to be the controlling current mechanism. Aging studies revealed that further forming is the dominant degradation mechanism in the early stages, while load‐line degradation and softening become the dominant degradation modes as the aging process is continued. The conventional DCPEL device structure was modified by introducing a thin chromium layer just prior to the deposition of the aluminum back electrode. Incorporating chromium reduced the initial series resistance of the device. A hybrid device employing a thin film (1 μm) of ZnS:Mn, sandwiched between two thin dielectric layers (5 nm), was fabricated; ZnS:Mn,Cu powder was sprayed onto the thin‐film sandwich. The hybrid structure showed good luminance without forming; however, device degradation with ti

ISSN:1071-0922    

DOI:10.1889/1.1984893

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—A new evaluation method of viewing‐angle characteristics for liquid‐crystal displays (LCDs) with gray‐scale images has been studied. In this method, reverse images, excessively dark images, and excessively bright images, which are a serious problem while displaying gray‐scale images, are evaluated quantitatively along with the display contrast ratio. The viewing‐angle characteristics of several types of LCDs are compared using

ISSN:1071-0922    

DOI:10.1889/1.1984894

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—A 1M‐pixel full‐color projection display with a very simple optical system using a conventional overhead projector has been developed. This display uses the nematic‐cholesteric phase‐transition liquid‐crystal display and a micro‐color‐filter. Moreover, the micro‐color‐filter can be placed outside the liquid‐crystal panel. This simple configuration provides a high‐performance low‐cost color electronic overhead projector. This projection display uses a 9M‐pixel nematic‐cholesteric phase‐transition black‐and‐white liquid‐crystal panel to enable gray shades by spatial dither, resulting in a full‐color projection display. A 12:1 contrast ratio and

ISSN:1071-0922    

DOI:10.1889/1.1984895

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—A direct‐view TFT‐LCD with a wide viewing angle, which uses a polymer‐dispersed liquid‐crystal panel and a pair of polarizers, is proposed. The device has a vertical viewing‐angle range of 120°, with a contrast ratio over 5:1 without display‐image reversal. This is about three times the twisted‐nematic display's vie

ISSN:1071-0922    

DOI:10.1889/1.1984896

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—For the first time, a poly‐CdSe active matrix with poly‐CdSe/poly‐Ge integrated driver circuits was realized. Despite compromises in device performance, induced by combining the existing driver and matrix technologies, excellent circuit results were obtained, with inverter delays down to 30 ns in a 25‐μm

ISSN:1071-0922    

DOI:10.1889/1.1984897

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract—Improved methods for testing thin‐film‐transistor (TFT) arrays are becoming increasingly important as TFT liquid‐crystal flat‐panel displays become the first choice in many applications. The in‐process method of functionally testing arrays described in this paper uses an optical charge‐sensing technique to identify the location and type of line and point defects. The method is non‐destructive and provides data which can be used to repair certain types of array defects. It can also be used to measure such TFT parameters as frequency response, threshold voltage, and chan

ISSN:1071-0922    

DOI:10.1889/1.1984898

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY