bluuebunny/crossref_metadata_2025 huggingface dataset:
Building simple yet powerful desktop LCD monitors
Authors: Eveleno F.
Published: May 2006

Abstract— This display‐interface system preserves the input signal in analog form, delivering analog voltages to analog drive circuits via sample‐and‐hold circuits. The system can also display signals with a variety of resolutions on a single LCD panel.
Development of a 15.5‐in. STN‐LCD monitor with CRT interface
Authors: Kudo Y. , Furuhashi T. , Nishitani S. , Mano H. , Uchida S.
Published: May 2006

Abstract— We have developed a 15.5‐in.‐diagonal XGA STN‐LCD monitor with a CRT interface. This STN‐LCD monitor can accelerate the frame frequency in order to optimize STN‐LCD driving, and realize a 260K‐color display. For this monitor development, we have developed the new Dual FRC method (D‐FRC), which can realize both saving of memory capacity and reducing flicker. We have optimized the display pattern of D‐FRC, and minimized crosstalk by the combination of D‐FRC and Hi‐Addressing (Advanced 2‐line simultaneous addressing).
Efficiency limits for fluorescent lamps and application to LCD backlighting
Authors: Pai R. Y.
Published: May 2006

Abstract— The parameters that determine the efficiencies for fluorescent lamps (FL) need to be examined in detail when applied to LCD backlighting. The potential exists for an increase of up to a factor of two in the efficiency of the lamps used in backlighting. The basic physics of fluorescent lighting, the effects of various parameters on efficiency, and the improvements in lamp technology as applied to LCD backlighting will be discussed.
Efficient illumination of color AMLCD projection displays using binary optical phase plates
Authors: Gale R. P. , Swanson G. J.
Published: May 2006

Abstract— We have developed a novel technique using binary optical phase plates that spatially separate the visible spectrum into three sub‐spectra of red, green, and blue, concentrating the subspectra at the appropriate AMLCD's pixel locations. Light efficacy of 1.4 ANSI lm/W was obtained using this technique in a single‐LCD system.
Hydrogenated amorphous silicon germanium black‐matrix material for active‐matrix liquid‐crystal displays
Authors: Klauk Hagen , Wright Steven L. , Palmateer Lauren F. , Mohney Suzanne E. , Jackson Thomas N.
Published: May 2006

Abstract—Integration of the black matrix (BM) in active‐matrix liquid‐crystal displays (AMLCDs) into the TFT array is desirable to improve display performance. This requires a black‐matrix material that is both an optical absorber and an electrical insulator. Amorphous silicon germanium (a‐SiGe:H) is a candidate material for this application. When deposited by magnetron sputtering, a‐SiGe:H can have both high optical density and high electrical resistivity. Compared to organic materials considered for black‐matrix integration, a‐SiGe:H offers higher optical density at a given film thickness, more‐flexible processing, and better process compatibility with AMLCD fabrication.
Transistor sizing for AMLCD integrated TFT drive circuits
Authors: Tomita Satoru , Jurichich Steven , Saraswat Krishna C.
Published: May 2006

Abstract— This paper discusses transistor sizing for active‐matrix liquid‐crystal displays (AMLCDs) with integrated drive circuits for computer display applications. The size of an output transistor of integrated drive circuits must be large enough to drive a scan/data line within an acceptable delay time and, at the same time, must be as small as possible to reduce the circuit area. Using a linear approximation for TFTs and the Elmore delay model for distributed RCs, we derive expressions for delay times of scan and data lines including the delay of the drive circuit, which has been ignored in the analysis of amorphous‐silicon TFT‐LCDs driven by external driver chips. Based on the derived delay times, sizes of output transistors are estimated. Our calculations show that integration of peripheral drive circuits is feasible and will give benefits in cost and packaging for display resolutions up to XGA. For higher resolution displays such as SXGA, integration of drive circuits will require large driver TFTs and complex external circuits and thus may be impractical.
Gallium‐rich CaGaαSβ:Ce as a new blue electroluminescent phosphor
Authors: Kato A. , Katayama M. , Mizutani A. , Ito N. , Hattori T.
Published: May 2006

Abstract— Ga‐rich CaGaαSβ: Ce thin films, of which the Ga/Ca ratio was 2.5–4, were grown by metalorganic chemical vapor deposition. After post‐annealing at 650°C, a new substance, different from the ordinary CaGa2S4, grew. This was confirmed by XRD and by a spectral shift of the Ce3+ emission. This phosphor was found not only to emit a deeper blue, (x, y) = (0.15, 0.16), than CaGa2S4: Ce, (x, y) = (0.15, 0.19), but also to be electroluminescent. Its luminance was 2 cd/m2 at 40 V above threshold at a frame frequency of 120 Hz.
PL studies of Ce3+‐ and Pr3+‐doped SrS thin films
Authors: Evans D. R. , Warren G. T. , Raukas M. , Happek U. , Dennis W. M. , Sun S.‐S. , Basun S. , Kane J. , Yocom P. N. , Naman A. , Holloway P.
Published: May 2006

Abstract— Both time‐resolved and steady‐state spectroscopic techniques were used to investigate the mechanisms responsible for both the observed increase in luminance and the red shift of the emission frequency that occurs when Ga is introduced during the growth of SrS: Ce3+ films. We compared the excitation spectra of SrS: Ce3+ films prepared without Ga to SrS: Ce3+ and SrS: Pr3+,Ce3+ films prepared with Ga. In addition, we also studied praseodymium‐doped thin films to probe the local environment of the rare‐earth ion in these materials. Finally, the implications of these results on the electroluminescent (EL) efficiency will be discussed.
Color‐coordinate control in TFEL devices using multicomponent oxide phosphors
Authors: Minami Tadatsugu , Kuroi Yoshikiro , Yamada Hiroyuki , Takata Shinzo
Published: May 2006

Abstract—This paper reports on attempts to control the color coordinate of the green emission from TFEL devices by varying the composition of multicomponent oxide phosphors in the host materials. In TFEL devices using multicomponent oxide phosphors composed of combinations of ZnGa2O4: Mn, ZnAl2O4: Mn, and MgGa2O4: Mn, the substitution of group‐III element sites rather than that of group‐II element sites is more effective for green‐color‐coordinate control. As for Zn(GazAl1−z)2O4: Mn or MgzZn1−z(GazAl1−z)O4: Mn phosphors, the EL emission spectra from the TFEL devices could also be controlled; consequently, the CIE chromaticity color coordinate could be changed. EL characteristics such as luminance and luminous efficacy remained relatively unchanged as the composition was varied up to aboutz= 0.5. A high‐luminance green emission suitable for full‐color displays was realized by TFEL devices using a multicomponent oxide phosphor such as Zn(Ga0.5Al0.5)2O4: c Mn.
Growth and characterization of a novel low‐voltage‐tunneling electroluminescent device
Authors: Tong W. , Wagner B. K. , Menkara H. , Chaimansour M. , Summers C. J. , Yocom N. , Ling M. , Martinelli R.
Published: May 2006

Abstract— A new electroluminescent device concept is proposed to achieve low‐voltage operation. The device is based on a lattice‐matched semiconductor/insulator/luminescent layer/insulator/semiconductor structure in which, under bias, high‐energy electrons are injected from the semiconductor into the electroluminescent layer. Details of the chemical‐beam epitaxy/molecular‐beam epitaxy (CBE/MBE) growth procedures for each of the layers required for this device structure are presented. Theoretical models were developed to simulate the device band diagrams and the tunneling process. Preliminary results indicate good agreement between the model and actual device operations in threshold voltage and I‐V behaviors.
Electroluminescent SrS:Ce thin films grown by gas‐source molecular‐beam epytaxy
Authors: Tong W. , Yang T. , Chaichimansour M. , Park W. , Wagner B. K. , Summers C. J. , Sun S.‐S. , King C. N.
Published: May 2006

Abstract— SrS:Ce thin films have been grown by gas‐source molecular‐beam epitaxy (GSMBE) for the development of high‐luminance, high‐efficiency electroluminescent (EL) flat‐panel displays. The growth conditions have been systematically investigated as a function of growth temperature, S to Sr flux ratio, Ce concentration, and ZnS and Mn co‐evaporation. Single‐crystal SrS and high‐quality SrS:Ce layers were successfully grown on GaAs and glass substrates, respectively, without a post‐annealing process at temperatures as low as 600°C. It was found that the grain size was greatly increased by co‐doping with Ga2S3 during the growth, providing a possible means to further decrease the growth temperature.
Effect of Zn codoping on Ce3+ emission in SrS electroluminescent thin films
Authors: Shanker Virendra , Fukada Horuki , Maesono Masaki , Ohmi Koutoku , Tanaka Shosaku , Kobayashi Hiroshi
Published: May 2006

Abstract— Ce emission in SrS thin films has been investigated in the temperature range of 6–300 K. Films codoped with Cl show a strong thermal quenching around 50 K with a thermal activation energy of 0.3–0.4 eV. The low activation energy indicates the presence of shallow quenching centers. These centers are probably created out of various possible complex centers formed due to pairing of strontium and sulfur vacancies with co‐activators and are associated with Ce emission centers. Ce in the presence of Cl has a greater tendency of forming Sr vacancies as compared to that in the presence of excess S. Zn codoping along with K has been found to reduce these vacancies and significantly improve the thermal stability of the luminescent characteristics of SrS:Ce thin films.
Synthesis and characterization of a light‐emitting diode from an alternating copolymer
Authors: Cho H. N. , Kim D. Y. , Kim Y. C. , Lee J. Y. , Kim C. Y.
Published: May 2006

Abstract— Poly(hexyl‐fluorenediylvinylene‐alt‐phenylenevinylene)(PHFPPV) has been synthesized by a Wittig reaction between a fluorene phosphonium salt and terephthalaldehyde. The alternating copolymer was thermally stable to be decomposed at 410°C and soluble in chloroform. The photoluminescence (PL) spectrum is very broad and has shoulders and a bump. The bump at 560 nm disappeared on dilution of the copolymer in chloroform. The EL spectrum is broad, but not as broad as the PL spectrum, and is significantly different from the PL spectrum. The quantum efficiency of the LED was 0.002% with aluminum as a negative electrode, and the turn‐on voltage was 20 V.
Pulsed‐laser deposition of ZnS and SrS for ACTFEL and field‐emission displays
Authors: Karner C. , Maguire P. , McLaughlin J. , Laverty S. , Graham W. G. , Morrow T. , Bowman R. M.
Published: May 2006

Abstract—High‐quality luminescent thin films of manganese‐doped zinc sulphide (ZnS: Mn) and strontium sulphide (SrS) with excellent stoichiometry have been grown by pulsed‐laser deposition (PLD). The crystallinity, stoichiometry, and cathodoluminescence have been investigated for films deposited onto two different substrate types under different deposition conditions. Furthermore, the importance of post‐deposition annealing has been studied. PLD ZnS: Mn thin films show increased cathodoluminescence (CL) when compared to sputtered thin films, peaking at 585 nm. SrS thin films grown at 450°C onto tin‐doped indium oxide (ITO) coated glass substrates show very good crystallinity, with a preferred orientation along the (200) axis. Cerium‐doped strontium sulphide (SrS: Ce) gives strong blue CL output at 400 nm. The films are stoichiometric and it has been shown that the stoichiometry is controllable by varying the deposition parameters.
UV‐induced charge transfer and light emission in ZnS‐based electroluminescent devices with probe layers
Authors: Neyts Kristiaan , Corlatan Dorina
Published: May 2006

Abstract— With transient measurements it is possible to investigate the electrical and optical characteristics of a thin‐film‐electroluminescent device for both polarities. With additional UV illumination the charge transfer and luminescence due to electrons and holes can be measured separately. The additional charges generated by the UV illumination make it possible to investigate electroluminescence at electric fields below the threshold in conventional thin‐film‐electroluminescent devices. The method and the results presented here are of great value for the fundamental understanding of charge‐transport and excitation processes in electroluminescent devices.
Active‐matrix electroluminescence and color EL displays
Authors: Tuenge Richard T.
Published: May 2006

Abstract— Active‐matrix‐electroluminescent (AMEL) displays using ZnS phosphors have demonstrated sufficient luminance, contrast, and stability under high‐frequency drive for commercial applications. Recently, color AMEL displays have been fabricated using either spatial or temporal filtering of the SrS: Ce/ZnS: Mn broad‐band emission. The SrS: Ce/ZnS: Mn broad‐band phosphor shows improved spectral balance under AMEL drive conditions. Higher‐efficiency blue emission remains the primary goal for achieving lower power in both active‐ and passive‐matrix color EL displays.
High‐luminance SrS: Ce, Ga, F thin‐film‐electroluminescent devices
Authors: Sun S.‐S. , Nguyen T. , Bowen M. S. , Kane J. , Yocom P. N. , Naman A. , Jones K. , Holloway P. H. , Evans D. R. , Dennis W. M.
Published: May 2006

Abstract— Gallium codoping has been identified as an effective flux agent for SrS:Ce phosphor thin films. When rapid‐thermal‐annealed at temperatures above 750°C, the microstructure of sputtered SrS: Ce, Ga, F thin films underwent a transformation from columnar to spherulitic morphology. In addition, the crystal grain size increased by tenfold from 50 to 500 nm. Time‐resolved photoluminescent measurements on 810°C‐annealed SrS: Ce, Ga, F films showed decay times as long as 25 ns, indicating effective incorporation of Ce ions. As a result of crystallinity improvement, excellent electroluminescent performance, e.g., 60‐Hz L40 of 155 cd/m2, has been achieved in EL devices with 1.5‐μm‐thick SrS: Ce, Ga, F films. In addition, high luminous efficacy, e.g., e40 = 1.15 lm/W, was achieved in devices with a thin SiON buffer layer added between the SrS:Ce and a BaTa2O6 top insulator.
New concepts for VUV phosphors with high quantum efficiency (q > 100%)
Authors: Donker H. , Wegh R. T. , Meijerink A. , Krupa J. C. , Queffelec M.
Published: May 2006

Abstract— The first overview of the 4f levels of Gd3+ in the VUV is reported. It is shown that quantum cutting is a very promising phenomenon to make VUV phosphors with a quantum efficiency greater than 100% and that the efficiency of this process can be improved by cross‐relaxation. The visible quantum efficiency of LiGdF4: Eu3+ 0.5 mol% upon excitation in the VUV is shown to be 195%.
Luminescence properties of Ca1−xSrxTiO3:Pr3+
Authors: Park Cheol‐Hee , Jeon Che‐Ik , Yu Byung‐Yong , Choi Han , Bae Hyun‐Sook , Kim Chang‐Hong , Pyun Chong‐Hong
Published: May 2006

Abstract— The phosphor CaTiO3:Pr3+ is highly regarded as a low‐voltage red phosphor because of its good color quality and intrinsic conductivity. Under 330‐nm excitation it shows red emission, which corresponds to the transition from 1D2 to 3H4. This transition is a forbidden f‐f electric dipole transition, but its fluorescence intensity is quite large in CaTiO3:Pr3+ and decreases in Ca1−xSrxTiO3:Pr3+ as x increases. In this study, luminescence properties of CaTiO3:Pr3+ have been investigated in terms of crystal structure, using the Eu3+ ion as a probe. The Pr3+ ion site in the CaTiO3:Pr3+ has no centrosymmetry, and the partial allowance of the 1D2 → 3H4 transition by the odd crystal‐field terms due to the loss of centrosymmetry gives quite strong emission. With the increase of the Sr ion substitution in Ca1−xSrxTiO3:Pr3+ prepared by heating at 1150°C, the fraction of the Pr3+ ions at inversion centers increases and the emission intensity decreases as the result.
Hydrothermal synthesis of rare‐earth magnetoplumbite phosphors for plasma‐display applications
Authors: Ravichandran D. , Roy Rustum , White William B.
Published: May 2006

Abstract— Green phosphors with a nominal composition Ce1−xTbxMgAl11O19 (CAT phosphors) (0.05 ≤ × ≤ 0.5) have been prepared under hydrothermal conditions. The phosphor CeMgAl11O19: Tb3+ crystallizes in the magnetoplumbite structure. The Tb3+ emission intensity at 545 nm varies with Tb3+ composition and reaches a maximum at × = 0.1. The excitation spectra were characteristic of Ce3+, but no Ce3+ emission was observed. Internal energy transfer from Ce3+ → Tb3+ is complete. SEM micrographs show well‐crystallized faceted crystal platelets with a particle size of ∼0.4 μm.
A high‐resolution CRT monitor using built‐in ultrasonic motors for focus adjustment
Authors: Kato Kazuo , Sase Takashi , Sasaki Kazuyosi , Niits Ichiro
Published: May 2006

Abstract—A digitally controlled focus‐adjustment system using built‐in ultrasonic motors for high‐resolution CRT monitors has been developed. It consists of two ultrasonic‐motor‐driven potentiometers, built into a CRT flyback transformer unit, and microprocessor‐controlled driver LSI. The motor has a simplified structure with an injection‐molded plastic rotor to ensure low‐cost manufacturing. Resonant‐frequency tracking of the motor is achieved with a digital frequency‐scanning method, instead of the conventional phase‐locked loop (PLL). This ensures fast pulse‐driven control. On the manufacturing floor, a factory control unit and a CCD camera are used. A monitor incorporating the focus‐adjustment system achieved an accurate focus adjustment (less than 0.3‐mm line width) with an adjustment time of less than 10 s. This satisfied the user's focus adjustment needs.
Procedure to verify digital color systems
Authors: Brill Michael H.
Published: May 2006

Abstract— The present environment for cross‐media color reproduction is fraught with communication problems and incompatibilities. To measure the extent to which this problem is being solved by new initiatives, a procedure is described to verify color transfer between video display units (VDUs) through a digital medium. In its simplest form, verification involves measuring the tristimulus values of a test pattern on a VDU and comparing them with published target values. To accommodate gamut mismatches, the test colors are desaturated enough to fit in most any device's color gamut. To accommodate white‐point differences, the test colors are adapted to each VDU's white point using an illuminant‐reflectance model. The procedure is reduced to practice in the simple case of 8‐bit RGB values used directly to drive one standard CRT and four test devices (including two flat‐panel displays). The initial tests involved simple RGB routing with no intervening color‐management system to reflect the character of the device. As an expected result, the color reproduction receives low marks through the present measurement criterion. Adjustment of the criterion as it meets reality is a subject for future endeavor.
Liquid‐crystal‐modulated photoluminescent displays (PLLCDs)
Authors: Crossland W. A. , Springle I. D. , Davey A. B.
Published: May 2006

Abstract— A simple but novel display architecture is presented which may have far‐reaching implications for the next generation of emissive LCDs. Liquid‐crystal modulators were used to control the amount of activating light falling upon a front‐face photoluminescent phosphor screen, resulting in unlimited viewing angle and efficient production of color. This paper explores the potential for such displays and demonstrates the increased performance obtained by operating a TN device in a photoluminescent LCD architecture.
Polymer‐stabilized cholesteric‐texture reverse‐mode light shutter: cell design
Authors: Ma Rui‐Qing , Yang Deng‐Ke
Published: May 2006

Abstract— Polymer‐stabilized cholesteric‐texture light shutters are made of cholesteric liquid crystal and polymer‐network dispersions. In the polymer‐stabilized cholesteric‐texture reverse‐mode light shutter, the dispersed polymer network stabilizes the transparent planar texture of the liquid crystal at zero field. When an electric field is applied to the dispersion, the liquid crystal is switched to the focal conic texture, which is optically scattering. We systematically studied the effects of the pitch of the liquid crystal on the electro‐optical properties of the light shutters. The dispersion can be used to make projection and reflective displays.
Nanocrystalline phosphors
Authors: Yang J. P. , Gray H. , Hsu D. , Qadri S. B. , Rubin G. , Ratna B. R. , Warren W. L. , Seager C. H.
Published: May 2006

Abstract— We report the first photoluminescent properties of manganese‐doped ZnS nanoparticles prepared in mesoporous cavities of a self‐assembled bicontinuous cubic phase of a surfactant. The average size of the nanocrystals was 2.5 ± 0.5 nm. The photoluminescence was maximum for 0.7 mole% of manganese in the aqueous solution used to make the nanocrystals. The quantum yield at this Mn concentration was greater than 20%, with an orange‐red emission at 592 nm. Electron paramagnetic resonance studies indicate that there is, on the average, less than one isolated Mn ion per nanocrystal.
Selective deposition and luminescence characterization of Eu‐doped Y2O3 nanoparticles by microwave plasma synthesis
Authors: Milewski P. D. , Streiffer S. K. , Kingon A. I. , Shmagin I. K. , Kolbas R. M. , Krishnankutty S.
Published: May 2006

Abstract— Nanosize phosphor particles of Eu‐doped Y2O3 were synthesized at room temperature by an organometallic vapor‐phase microwave plasma‐synthesis technique. These particles were selectively deposited downstream of the plasma reaction region to form thin layers on biased regions of a substrate. Particles were characterized using x‐ray diffraction and transmission electron microscopy. The morphologies of the thin phosphor layers were studied using field‐emission scanning electron microscopy. Results indicate that the particles form a fibrous structure with good selectivity for thicknesses less than 100 nm. The nanoparticle‐phosphor optical characteristics were analyzed using absorption and photoluminescence spectroscopy. These results indicate that the particles have absorption and luminescence spectra similar to the bulk. This study demonstrates that the microwave plasma‐synthesis technique may provide an effective method for producing phosphor screens that meet many of the needs of advanced cathodoluminescent low‐voltage devices.
Characterization and surface treatment of FED phosphors
Authors: Herrick Robert D. , Stickney John L.
Published: May 2006

Abstract— Wet chemical treatments have been performed on phosphor particles. ZnO: Zn phosphor was reductively etched with a basic aqueous solution of sodium borohydride. The etch resulted in a two‐fold increase in the cathodoluminescent efficiency without any detected change in particle size or surface composition as detected by Auger electron spectroscopy. The low‐voltage cathodoluminescent characteristics are particularly enhanced. The enhanced efficiency of the phosphor particles may be attributable to a change in surface structure or an increase in the surface coverage of luminescent centers induced by the reductive etch.
Colloid chemical analysis of the processes of coating formation from dispersed phosphors
Authors: Soltys M. M. , Yaremko Z. M. , Havryliv V. D. , Pidzyrailo M. S.
Published: May 2006

Abstract— The influence of colloidal chemical properties on the stability of phosphor suspensions and the conditions of formation of luminescent screens were studied. The stability of the phosphor dispersion against aggregation strongly influences the particle packing density and the thickness of the coating. The aggregation of phosphor powder particles in the dispersion causes mass‐density variation in the phosphor coatings and degrades the luminescent characteristics of the screens. Dispersion conditions that provide a high packing density of phosphor particles and increase the quality of the cathodoluminescent coatings were found.
New phosphors in the SrS‐Sc2S3 system doped with Eu
Authors: Drozdova Svetlana V. , Lashkarev George V. , Malakhov Vladislav Ya.
Published: May 2006

Abstract— The synthesis conditions for the Eu‐activated SrS‐Sc2S3 phosphor system were studied. These results along with the relative CL performance are reported.
Preparation of spherical phosphors by thermal‐plasma treatment
Authors: Matsuda N. , Tamatani M. , Okumura M. , Albessard A. K. , Inoue Y. , Kawasaki K.
Published: May 2006

Abstract— Garnet‐structured rare‐earth oxysulfide and zinc sulfide phosphors were treated by thermal plasma in order to obtain spherically shaped phosphor particles. Although spherical particles of garnet phosphor and rare‐earth oxysulfide phosphor were obtained, their luminescence properties were lowered. However, the properties could be partially restored by optimized heat treatment.
Phosphor‐efficiency dependence on pulse duration in field‐emission devices
Authors: Seleznev B. V. , Kandidov A. V. , Rakhimov A. T. , Sostchin N. P.
Published: May 2006

Abstract— The dependence of the cathodoluminescence (CL) efficiencies of Y2O2S: Eu, Y2O2S: Pr, Y2O3:Eu, and (Cd, Zn)S: Cu, Al on the width of high‐current‐density excitation pulses was found to be dependent upon the persistence time of the phosphors. This dependence was explained in terms of phosphor saturation.
Luminescence of rare‐earth‐activated Ga‐containing oxides by low‐energy electron excitation
Authors: Yamamoto Hajime , Suda Yoriko
Published: May 2006

Abstract— It was previously reported that the thermoluminescence intensity increases with an increase in Ga content in Y3(Al1−xGax)5O12:Tb3+ and LaAl1−xGaxO3:Tm3+. This fact suggests that electrical conductivity may be also increased with Ga content, because traps responsible for thermoluminescence can supply free electrons. In this work a correlation is found between the Ga content and electrical conductivity of the above phosphors, which was measured by means of the threshold anode voltage of vacuum‐fluorescent displays (VFDs) using these phosphors, where the anode current or luminance builds up. In a series of Y3(Al1−xGax)5O12:Tb3+, the maximum efficiency is obtained at the composition x = 0.4; it is about 50% higher than the efficiency of ZnGa2O4:Mn2+. Incorporation of In also decreases the threshold voltage, but it decreases the efficiency as well. The traps supplying carriers can be ascribed to oxygen vacancies and/or Ga+.
A new material for thin‐film low‐voltage blue phosphors
Authors: Langley Robert J. , Pettis Gregory F. , Kurinec Santosh K. , Potter Michael D.
Published: May 2006

Abstract— Blue cathodoluminescence (CL) with a spectral peak at 400 nm is reported in tantalum‐incorporated ZnO thin films at low voltages. The CL is visible at 10 V at a current density of 10 μA/cm2. The CL chromaticity coordinates are found to be x = 0.160, y = 0.075. The films have been prepared by depositing a thin tantalum film on rf‐magnetron‐sputtered and annealed ZnO films, followed by another annealing step. The films also exhibit strong photoluminescence, peaking at 383 nm (3.2 eV). The x‐ray‐diffraction analysis shows the presence of a Ta2Zn3O8 phase in these films, which is believed to be responsible for the observed luminescence.
Characterization of thin‐film blue SrGa2S4 phosphors for low‐to‐medium‐energy cathodoluminescent displays
Authors: Chakhovskoi A. G. , Hunt C. E. , Yang T. , Wagner B. K. , Summers C. J. , Malinowski M. E. , Felter T. E.
Published: May 2006

Abstract— The spectral response, luminance, and outgassing characteristics of new, thin‐film Ce‐activated SrGa2S4 phosphors for application in field‐emission flat‐panel displays are presented. The tested phosphor materials are prepared using molecular beam epitaxy. The sample screens are tested with e‐beam excitation at currents up to 50 μA within the 200–2000 V (i.e., “low‐voltage”) and 3–8 kV (i.e., “medium‐voltage”) ranges. The spectral coordinates are compared to those of commercial low‐voltage phosphors. Phosphor outgassing, as a function of time, is measured with a residual gas analyzer at a fixed 50‐μA beam current in the low‐voltage range. We find that levels of outgassing stabilize to low values within the first hour of excitation. The desorption rates measured from thin films are compared to previously studied desorption parameters for powder phosphor layers.
New blue‐emitting phosphor thin films for FEDs
Authors: Gibbons C. S. , Vecht A. , Smith D. W. , Jing X.
Published: May 2006

Abstract— Although considerable progress has been made in the investigation of blue‐emitting phosphors for CRT application, there have been very few challenges to replace zinc sulfide silver. This phosphor, with which efficiencies of greater than 20% can be obtained, limited the effort invested in other blue systems. The need for low voltage, as well as other high‐loading phosphors, however, pointed to a change of emphasis. The sulfide systems were not stable under these conditions and only P47, yttrium silicate cerium, has been used, with limited success. We felt that the narrow‐band Eu2+ phosphors would not yield the efficiencies required. At the University of Greenwich, a systematic investigation into refractory oxide phosphors using other rare‐earth or transition‐metal activators was thus initiated. These were directed at the preparation of powder and thin‐film phosphor systems. The work reported here is on the synthesis and properties of thin films.
Charged‐particle detection using storage phosphor crystals
Authors: Kulik Alexei , Rosenfeld Carl
Published: May 2006

Abstract— We propose a detector of charged particles based on photostimulated luminescence (PSL) of single crystals. Such a detector potentially allows for high space resolution (tens of microns) over a large area and excellent pattern recognition (it is non‐projective). Potentially, it is competitive with existing detectors both in price and performance. The detectors may be used in neutrino or other low‐rate experiments. We demonstrate detection of α particles with an average signal of 190 photoelectrons and estimate a minimum‐ionizing particle to yield 50 photoelectrons per millimeter of track. The noise level of 15 photoelectrons RMS is limited by technical issues, and there is a clear perspective to reduce it greatly.
Investigation into variable‐addressibility image sensor and display systems
Authors: Kubala Kenny , Hatch Andrew , Hooker R. Brian , Lewis Lindon
Published: May 2006

Abstract—The eye's acuity varies across its field of view, decreasing to 10% of its axial value at only 20°. This creates a situation where standard displays, when used in conjunction with the eye, present more information than can be perceived. This paper describes an optical system that has been developed that radially re‐maps the pixels of a miniature display or sensor to match the varying acuity of the eye across its field of view. This system increases the field of view of an electronic viewing system without any apparent loss in image quality.
Optical approaches to incorporation of displays within eyeglasses
Authors: Spitzer M. B. , Aquilino P. D. , McClelland R. W. , Olson M. H. , Rensing N. M. , DiMarzio C. A. , Zavracky P. M. , Lemoncelli A. , Hilliar J.
Published: May 2006

Abstract—We report the development of a new approach to design and fabrication of eyeglass‐based displays. The principal feature of this technique is the incorporation of an optical relay between the display and the eye within the eyeglass lens, and the incorporation of a display within the eyeglass temple. Color eyeglass‐based displays are described.
Material and component optimization for in‐plane‐switching (IPS) TFT‐LCDs
Authors: Kondo K. , Matsuyama S. , Konishi N. , Kawakami H.
Published: May 2006

Abstract— Materials and components for IPS (in‐plane‐switching) TFT‐LCDs are optimized based on a basic analysis of the in‐plane switching behavior of nematic liquid crystals. We have developed materials and components accessible for mass‐producible and commercially available IPS TFT‐LCDs. New phenomena, unlike those found in conventional TN‐TFT‐LCDs, such as a higher holding ratio characteristic which is specific to the IPS mode, are found. An optimization procedure for a liquid‐crystal mixture and a color filter is reviewed. By using new materials and components, we have supplied an IPS‐TFT‐LC module consisting of a common driver LSI whose driving voltage is 5 V with a response speed of 60 ms (rise + fall), almost comparable to that of conventional TN‐TFT‐LCDs. Finally, our recent development toward a faster response speed of 25 ms, which is applicable to a moving‐picture display, is discussed.
Advanced ASM mode (axially symmetric aligned microcell mode): Improvement of display performance by using a negative‐dielectric liquid crystal
Authors: Kume Y. , Yamada N. , Kozaki S. , Kisishita H. , Funada F. , Hijikigawa M.
Published: May 2006

Abstract— We have developed an advanced axially symmetric aligned microcell mode using negative‐dielectric liquid crystal (N‐type ASM mode), the first in the world. Using compensation film for this N‐type ASM mode cell realizes the wide viewing angle of ±,80° in all azimuths, and a high contrast ratio of 300:1. The structure of this N‐type ASM‐mode panel is suitable for large‐sized display panels. This mode is applicable for such active display panels as TFT and PALC1 displays, regardless of the difference of their drive systems. We consider that this N‐type ASM mode will be a key technology for next‐generation monitors.
Akzo Nobel Twistar™: LCP‐retarder films with improved temperature‐matched compensation
Authors: Bosma M.
Published: May 2006

Abstract— Twistar™ is Akzo Nobel's LCP retarder, which can provide full compensation of the birefringence effects of STN liquid‐crystal displays by using only a single, thin, polymer layer. The birefringence of Twistar™ decreases with increasing temperature giving this retarder the unique ability to provide full compensation of the display over a broad range of temperatures. The use of Twistar™ can considerably increase the maximum temperature at which a film‐compensated display can be used. Even for temperature‐critical applications in which currently only double‐cell STN (DSTN) displays can be used, Twistar™ can replace the compensation cell while maintaining the broad working‐temperature range. In this paper the Twistar™‐retarder will be described in detail. Experimental data of the temperature‐matched compensation of this retarder are given.
Reflective color display using cholesteric liquid crystals
Authors: Hashimoto K. , Okada M. , Nishiguchi K. , Masazumi N. , Yamakawa E. , Taniguchi T.
Published: May 2006

Abstract— A stacked‐type reflective color display using cholesteric liquid crystals has been developed. The display has high luminance and 512‐color capability. This device also has display‐image memory features without a field owing to its intermediate multi‐stability. We will discuss a new fast‐addressing scheme and device construction to obtain intermediate stability and excellent color‐display characteristics.
Optical design of R‐OCB mode full‐color reflective LCD with wide viewing angle and high contrast
Authors: Ishinabe Takahiro , Miyashita Tetsuya , Uchida Tatsuo
Published: May 2006

Abstract— One‐polarizer‐type reflective LCDs have been developed for reflective color LCDs with high resolution and high luminance. However, in order to apply them to high‐quality monitor displays, their contrast ratio is not sufficiently high in terms of wavelength and viewing angle. In this paper, we discuss the design rule for liquid‐crystal layer and retardation films for one‐polarizer‐type reflective LCDs in order to achieve high quality, especially high contrast ratio, for monitor displays.
Optimization of light‐valve mirrors
Authors: Colgan E. G. , Doany F. , Lu M. , Rosenbluth A. , Yang K.‐H. , Uda M. , Shinohara M. , Tomooka T. , Tsukamoto T.
Published: May 2006

Abstract—A mirror structure for reflective Si‐based light valves was fabricated using chemical‐mechanical polishing and a thin 150‐nm Al(Cu)/Ti mirror to minimize hillock formation. The use of chemical‐mechanical polishing planarization resulted in only a 1% loss in reflectivity from topography under the mirrors. The reflectivity for pixel sizes from 7.5 to 40 μm and 0.7‐ or 0.5‐μ.m gaps were measured, and the performance of TN LC pixels with different sizes and inversion methods are reported.
High‐information‐content projection display based on reflective LC‐on‐silicon light valves
Authors: Melcher R. L. , Ohhata Mototsugu , Enami Kunio
Published: May 2006

Abstract— A projection display has been developed based on reflective liquid‐crystal light valves fabricated on a crystalline‐silicon active‐matrix array. The light valves utilize the 45° twisted‐nematic LC mode. The optical system is based on dichroic‐mirror color separation, three polarizing beam splitters, and a dichroic color‐combining cube. The display has native SXGA or UXGA resolution with full multisync capability for other formats and provides >1000 ANSI lumens and >300:1 full‐field contrast ratio.
Full‐color organic EL display
Authors: Hosokawa C. , Matsuura M. , Eida M. , Fukuoka K. , Tokailin H. , Kusumoto T.
Published: May 2006

Abstract—For the first time, we report a full‐color organic display with 10‐in. diagonal and high resolution (VGA). This display was based on blue organic EL with color‐changing mediums (CCM). A blue‐emitting material with heat resistance was developed and used. In the construction of the full‐color display, we used a tapered In2O3‐ZnO with Al auxiliary electrodes as an anode with a low resistivity of 2 Ω/□. In addition, the CCM structure was improved in order to increase the contrast ratio of the display.
A new thin CRT
Authors: Van Gorkom G. G. P. , Baller T. S. , Lambert N. , Trompenaars P. H. F. , Van Velzen J. , de Zwart S. T.
Published: May 2006

Abstract— A description of the principles, the operation, the underlying physics, the technology, system aspects, and the performance of a new flat thin CRT, as invented and realized in the Philips Research Laboratories, is given. The panel operation is based on controlled electron (“hop”) transport in vacuum through insulating structures, enabling the use of mechanical supports inside the envelope to withstand the atmospheric pressure. The resulting flat panel has a thickness of about 1 cm for any panel size, a relatively low mass, and a reduced number of outside connections. The “hop”‐transport process is based on a self‐regulating secondary‐emission process. This process involves charge deposition by electrons landing on insulating surfaces. These modify the potential distribution until a steady state is reached in which exactly one electron leaves the surface for each electron impinging on the insulator. This process is used throughout the panel to guide the electrons from the cathodes to the addressed dots at the phosphor screen. The techniques and the processes used for making the panels are described. These include a refined powder‐blast process for three‐dimensional structuring of thin glass plates, a wet‐chemical process for realizing metal tracks on glass plates, and a low‐cost process for depositing thin MgO layers. System aspects concerning the application of the flat panel in TV sets are discussed, and some of the electronic circuitry, including newly developed ICs needed for driving the panel, is described. A two‐step addressing system allows the implementation of a novel multiplexing scheme, which leads to a more than three‐fold reduction in the number of outside connections. Experimental 17‐in. panels show good performance in terms of luminance, contrast, color purity, luminous efficacy, and viewing angle. Picture‐uniformity aspects deserve further investigation, but already some good results have been obtained. The same can be said for the lifetime of the panel.
Dynamic color separation (DCS) for color CRT displays
Authors: Washburn Clayton A.
Published: May 2006

Abstract— Dynamic color separation (DCS) is a means to higher performance and more‐efficient CRT color displays. A brief background and introduction of the basic concepts is followed by examples of implementation. Then performance characteristics are developed and compared with current conventional display methods. DCS departs from the sequential color separation (SCS) of early TV “indexing.” Removal of SCS time and space limitations and easing of its beam‐size restriction results in an efficient high‐performance DCS display.
Using sinusoidal spectral power distributions to evaluate color scanning filters
Authors: Kotera Hiroaki , Fumoto Teruo , Yoshida Kunio
Published: May 2006

Abstract— We demonstrate a method for evaluating the quality of color scanning‐filter sets that use sinusoidal spectral power distributions (sine SPDs) instead of physical test targets. Filter quality is quantified as the mean square error of the filter sets' responses to the fundamental metamers of sine SPDs having varying frequency and phase, relative to a perfect filter set. Filter quality is also depicted graphically by plotting filter input versus output in CIELAB color space, and by plotting the magnitude of the filters' CIELAB color vector response to sine SPDs. The advantages of this approach to scanning‐filter evaluation are discussed.
Analysis and design of a multicolor STN‐LCD on the Poincaré sphere
Authors: Kang Ki Hyung , Moon Jeong Min , Yoon Tae‐Hoon , Kim Jae Chang , Lee Gi‐Dong , Lee Eung‐Sang
Published: May 2006

Abstract— A multicolor STN‐LCD based on the electrical control of birefringence was analyzed and designed on the Poincaré sphere. The optical conditions of the cell were chosen from the Poincaré sphere. A retardation film provides brighter white, red, blue, and green colors within a small applied‐voltage variation. Experimental results show good agreement with numerical calculations.
Alignment layers for cholesteric displays on glass and plastic substrates
Authors: Bunz Rainer , Kallfass Traugott , Buerkle Roland , Becker Stefan , Sautter Barbara , Lueder Ernst
Published: May 2006

Abstract— The optical performance of surface‐stabilized cholesteric liquid‐crystal displays (SCT‐LCDs) has been optimized by using obliquely sputtered SiO2 as the alignment layer. A comparison with polyimides used up to now showed an improvement in the contrast ratio by a factor of 2 for glass displays. A second advantage of this material is the absence of high temperatures during the manufacturing process. Therefore, it is possible to use obliquely sputtered SiO2 for the preparation of plastic display prototypes. We have realized a 6‐in. VGA display with approximately 130 dpi. This is the largest cholesteric display with the highest resolution fabricated on plastic substrates to date.
Reflective and transflective color LCDs with double polarizers
Authors: Maeda T. , Matsushima T. , Okamoto E. , Wada H. , Okumura O. , Iino S.
Published: May 2006

Abstract— Reflective color LCDs with double polarizers have been developed by means of optimizing liquid‐crystal modes, aperture ratio, color‐filter properties, thickness of the glass substrate, polarizers, reflectors, etc. These LCDs are sufficiently bright, display many colors, have good hue, and are light weight with thin outline and low power consumption. Since they have double polarizers, a very high contrast ratio can be obtained. Therefore, they are superior in text character displays. Moreover, transflective color LCDs have been developed without visible deterioration of reflective displays by adoption of a reflective polarizer and backlight system in place of a lower polarizer and reflector.
Full‐color reflective display device using holographically fabricated polymer‐dispersed liquid crystal (HPDLC)
Authors: Date Munekazu , Takeuchi Yoshie , Tanaka Keiji , Kato Kinya
Published: May 2006

Abstract— A method of controlling the color of a holographic polymer‐dispersed liquid‐crystal (HPDLC) reflective display device has been achieved. By merely controlling the optical setup during fabrication, without changing the materials or laser light source, three primary‐color devices were fabricated. Since the color of the device can be controlled continuously, a large color‐reproducible area on the chromaticity diagram can be obtained. The resulting device was adequately transparent at other wavelengths to enable multiple devices to be stacked to obtain a mixture of colors. There was no significant change in color when applying an electric field. The three devices had similar reflectances and electro‐optical characteristics. Therefore, this device has good potential for full‐color display applications.
Flexible and bistable FLC and cholesteric displays on plastic substrates for mobile applications and smart cards
Authors: Lueder Ernst , Buerkle Roland , Muecke Martin , Klette Ruediger , Bunz Rainer , Kallfass Traugott
Published: May 2006

Abstract— New smart‐card applications like purse cards, etc. require an integrated display which allows the card‐holder to read information which is stored on the IC of the card. On the other hand, the integration of a display into a plastic card requires some very specific features like flexibility and pressure stability, low‐voltage CMOS‐addressing, memory capability, and, of course, a reflective mode since no backlight is available. In this paper, two bistable reflective LCD solutions using ferroelectric and cholesteric LCs are discussed and very promising prototype results are presented. Pressure and bending tests as well as contrast measurements are compared in order to show the potential of meeting the requirements for use in smart cards.
Multiple color high resolution reflective cholesteric liquid crystal displays
Authors: Davis D. , Khan A. , Jones C. , Huang X. Y. , Doane J. W.
Published: May 2006

Abstract—A high‐resolution multiple‐color and black‐on‐white surface‐stabilized reflective cholesteric liquid‐crystal display with reflectivities as high as 40% is reported. The double‐stacked 1/8‐VGA, 100‐dpi prototype shows four vivid colors with negligible parallax. The potential for eight colors and ultimately full color is demonstrated in a high‐resolution triple‐stacked prototype.
Optimization of polymer‐stabilized bistable black‐white cholesteric reflective display
Authors: Ma Rui‐Qing , Yang Deng‐Ke
Published: May 2006

Abstract— Cholesteric liquid crystals at zero field exhibit two optically contrasting stable states: planar texture and focal‐conic texture. When a cholesteric liquid crystal is in the planar texture, the helical axis is perpendicular to the cell surface; the material Bragg‐reflects colored light. When the liquid crystal is in the focal‐conic texture, the helical axis is more or less parallel to the cell surface; the material is forward‐scattering and has a black appearance if the back plate of the cell is painted black. We develop a cholesteric liquid‐crystal/polymer composite in which a small amount of polymer is dispersed in the liquid crystal. The dispersed polymer changes the planar texture to a poly‐domain structure, which has a white appearance but has little effect on the optical properties of the focal‐conic texture. The result is a bistable black‐white reflective display which is a good candidate for electronic‐paper applications.
Improving the display performance of reflective color LCDs with micro‐cone‐structure film
Authors: Shao Xibin , Cuo Jianxin , Wu Sheng , Yuan Jianfeng , Huang Ximin
Published: May 2006

Abstract— A micro‐cone‐structure film was proposed to improve the viewing angle of reflective color LCDs, both in chromaticity and brightness. The simulation results show that the film works as a collimating layer when the light is incident from the bottom side of cone and as a scattering layer when the light is incident from the tip side. The viewing‐angle dependence of reflective interference color filters (RICF) is weakened dramatically by including such a film. The film is not only useful to RICF, but also to most reflective color LCD modes.
A reflective‐mode EEPROM‐based silicon light‐valve technology
Authors: Moore Paul , Cacharelis Philip , Frazee Jerry , Chung David , Luttrell Rick , Flack Russell
Published: May 2006

Abstract— A single‐crystal‐silicon light‐valve technology was created by optimizing a 0.8‐mgr;m EEPROM process flow to satisfy the electrical and optical requirements of the light valve's transducer, a polymer‐dispersed liquid crystal (PDLC).