摘要:

Abstract—Recently discovered visible‐emitting porous silicon can potentially lead to many advanced optoelectronic devices, including a new class of flat‐panel displays which can feature monolithic integration of light‐emitting pixels and associated driver electronics on a single substrate, using relatively simple and cost‐effective fabrication processes. Our research group has prepared porous‐silicon layers with strong visible photoluminescence (PL) and has demonstrated one of the first solid‐state electroluminescent (EL) devices in bulk monocrystalline Si material. In addition, we have extended our work beyond bulk Si and have demonstrated visible PL in thin films of porous polycrystalline Si (PPSI) formed on glass substrates. Very recently, we have demonstrated the first electrically induced visible luminescence in PPSI films formed on ITO‐coated glass faceplates. Though not measured quantitatively, the EL emission can be viewed clearly through the glass faceplate in daylight. In this paper, we discuss the potential display applications of both bulk and thin‐film porous Si and explain some of the challenges involved in fabricating devices using th

ISSN:1071-0922    

DOI:10.1889/1.1984934

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract—Dichroic sheet polarizers required for most liquid‐crystal displays are generally modeled as simple uniaxial films. This leads, however, to significant errors in display modeling at high viewing angles, both in luminance and spectral transmission. The primary source of these errors appears to be a negative out‐of‐plane birefringence (on the order of 50 nm for sample polarizers) of the protective outer layers of the polarizer. A straightforward methodology for measuring the relevant optical properties for modeling purposes via transmission measurements through crossed polarizers and optical microscopy is de

ISSN:1071-0922    

DOI:10.1889/1.1984935

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract—Liquid‐crystal molecules on a rubbed‐polymer alignment layer are oriented at a polar angle tilted away from the surface, but the physical reason for this pretilt is not clearly understood. We have developed a new method to determine the three‐dimensionally tilted direction of the polymer by precise measurement of the optical retardation. By using this method, we determined the inclination angle of the polymer molecules near the surface of the polymer as a function of rubbing strength. Three kinds of polymers were investigated, including one main‐chain type (low pretilt) and two side‐chain types (high‐pretilt and homeotropic alignment). The mechanism of pretilt generation is determined by comparing the relation between the inclination angle of the polymers and the pretilt angle of the li

ISSN:1071-0922    

DOI:10.1889/1.1984936

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract—A method which allows a reliable adjustment of the cell gap in liquid‐crystal displays is presented. A method for calculating the gap of a cell subjected to an external pressure is discussed, and a measuring procedure for verifying the results is described. The influence on the cell gap of parameters such as the elasticity of the spacers and substrates, the size and concentration of the spacers, and the external pressure is examined. In addition, the average indentation of the spacers into the substrate surface is calculated. The viscoelastic properties of polymer spacers were obser

ISSN:1071-0922    

DOI:10.1889/1.1984937

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract—The display quality of active‐matrix LCDs has been greatly improved. However, the problem of narrow viewing angle has not yet been sufficiently solved. In order to solve this problem, a new LCD comprised of a bend‐alignment LCD cell with an optical compensator was designed. The improvement is shown by theoretical and experimental ana

ISSN:1071-0922    

DOI:10.1889/1.1984938

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Abstract—A strategy is presented for reducing the power consumed by the fluorescent backlight in an active‐matrix liquid‐crystal display (AMLCD). This strategy centers on dynamically minimizing the backlight intensity, based on the content of the images being displayed. Implementation of this dynamic power‐management strategy requires very little additional logic in the video con

ISSN:1071-0922    

DOI:10.1889/1.1984939

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY