色阻堆叠在阵列基板上形成液晶屏隔垫物的研究

报道了一种新型液晶显示屏间隙支撑隔垫物的关键技术,可以替换传统的半透/灰阶曝光工艺,仅使用一张普通的全透光罩即可实现不同的支撑高度需求,并且达到遮光的效果,大幅节约了制备成本,可用于曲面或柔性显示面板。其中,主要隔垫物由两层色阻材料堆叠衬垫并覆盖平坦化层及黑色的光阻材料形成高度,辅助隔垫物由一层色阻衬垫并覆盖平坦化层及黑色的光阻材料形成高度,主/辅隔垫物的各自高度及它们之间的段差可以通过改变衬垫色阻的尺寸及平坦化层厚度进行调节。这种调节方式可以使主隔垫物高度的调节范围达0.6μm,辅助隔垫物高度的调节范围为0.5μm,它们之间的段差可以在0.2～1.3μm之间调节,理想段差位于此区间内。基于上述技术制备的液晶显示屏具有良好的显示效果,可用于高世代大尺寸液晶显示面板的生产。     

Design, construction, and performance of the Leighton10.4-m-diameter radio telescopes

The design, construction, and measurement of 10-m-class radio telescopes operating at millimeter and submillimeter wavelengths present many challenges. The radio telescopes developed by Robert Leighton provide a solution to these problems. These 10.4-m-diameter telescopes have diffraction-limited beams at wavelengths as short as 300 μm. The paper describes the techniques Robert Leighton developed to solve many of the problems in building precision telescopes. The areas covered include the design of the homologous reflector support structure, the computer program used to accurately predict the deformation of the surface, the construction techniques used to minimize the stress and bending moments in the structure, and the methods developed for producing and measuring a 10.4-m-diameter reflector surface to the required accuracy. The reflectors for the Leighton telescopes consist of honeycomb Al panels supported on a steel spaceframe backing structure. The spaceframe utilizes precision machined members and pin joints. The 84 panels form a hexagonal tiling pattern in the aperture plane and are figured using a custom-built machine. The Al reflecting surface is then applied to the front of each panel. The telescopes are routinely fabricated and installed with an rms surface accuracy of less than 35 μm without any adjustments/corrections. Computer calculations of the homologous deformation of the telescopes as they move in elevation have been verified by holography. A Leighton telescope installed at the Caltech Submillimeter Observatory on Mauna Kea, HI, has achieved an accuracy of <20 μm     

Upgrade of a large millimeter-wavelength radio telescope forimproved performance at 115 GHz

A 20.1-m-diameter radome enclosed radio telescope, built by Electronic Space Systems Corporation (ESSCO) at the Onsala Space Observatory (OSO) near Gothenberg, Sweden, in 1975, was upgraded by ESSCO in 1992 for improved operation at 115 GHz, increasing the system aperture efficiency from 20% to 40% at this higher frequency. Electrical gain measurements confirm geometric optics predictions of efficiency and improved antenna patterns. The upgrade included replacement of the two inner reflector panel rows with 31-μm panels, stiffening the reflector backstructure based on finite-element structural analysis for a measured rms gravity deformation of 59 μm in the 25° to 70° elevation range, and optical alignment of the reflector surface to 58 μm rms accuracy. This alignment accuracy of approximately 1/345000 of the reflector diameter was accomplished with an electronic angle-measuring theodolite and digital radial strap gauges. Data were downloaded in real time to an on-line portable computer performing surface metrology calculations. Graphical data are presented that compare computer predictions of reflector backstructure gravity deformations to optical measurements, which proved crucial in achieving the stringent alignment accuracies. Measured antenna efficiency data before and after the upgrade are included     

High-speed continuously tunable liquid crystal filter for WDMnetworks

We describe a high-speed wavelength tunable liquid crystal filter which can be utilized as the tuning element at the receiving end of wavelength division multiaccess (WDMA) optical networks. The filter uses chiral smectic A electroclinic liquid crystals as the active cavity material in a Fabry-Perot etalon in order to obtain a microsecond switching speed. Using the commercially available BDH764E liquid crystal material, we demonstrate a tunable optical filter both in a bulk Fabry-Perot and a fiber Fabry-Perot (FFP) configuration. A bandwidth of about 0.7 mm and effective finesse of 70 were obtained in the FFP configuration. A FFP tuning range of 13 nm with a switching time of less than 10 μs were measured at the operating wavelength of 1.55 μm. A theoretical analysis of the expected filter performance in the FFP configuration is given. Diffraction in the Fabry-Perot cavity is identified as the dominant loss factor, resulting in reduced throughput and finesse broadening. It is calculated theoretically that an effective finesse of 130 and a throughput loss of 2.2 dB are achievable for a mirror finesse of 200 and a liquid crystal cavity thickness of 5 μm. A short waveguide piece is assumed to be included in the cavity. Other expected loss sources for the filter in the FFP configuration have been calculated, showing negligible effect on the filter performance     

Electrophoretic image display (EPID) panel

A new reflective-type electrophoretic image display (EPID) panel is described which is based on electrophoresis. In the EPID panel, a suspension is mainly composed of pigment particles and a suspending liquid. A dc voltage applied across a suspension layer changes the reflective color of the suspension as a result of the electrophoretic migration of the particles. The precipitation of the particles in the suspension is prevented by making the densities of the pigment particles and the suspending liquid equal. Color combinations of both the pigment particles and the suspending liquid can be used to achieve a desired color display. A reversal between the colors of the displayed pattern and its background can be obtained by changing the polarities of the applied dc voltage. The EPID panel has a memory function because of the deposition of the pigment particles on the electrode surface. A reflective contrast ratio of 40:1 at 75 V dc is demonstrated with experimental EPID panels. Rise and fall times of the panels are 20 ms and 10 ms, respectively, at 100 V ac. Power dissipation of the panel is about 7.5 mW for displaying a numeral "8" (107 by 59 mm²).     

A compact low-power BiCMOS log-domain filter

A third-order Chebyshev filter based on the log-domain principle and integrated in a 1-μm BiCMOS process is presented. It has a nominal cutoff frequency of 320 kHz corresponding to a bias current of 1 μA, and can be frequency tuned over almost three decades up to about 10 MHz. It operates with a nominal supply voltage of 1.2 V, maintaining a dynamic range (DR) at 1% THD of 57 dB. For cutoff frequencies in the range of 10 kHz, the supply voltage can be reduced down to 0.9 V. The filter occupies an active area of 0.25 mm² and dissipates 23 μW, corresponding to a power consumption per pole and edge frequency of only 24 pJ. These results demonstrate the potential of log-domain filters for very low-voltage and low-power applications     

Epitaxially grown GaN thin-film SAW filter with high velocity andlow insertion loss

This study proposes GaN thin film as a piezoelectric material for SAW (surface acoustic wave) filters. Highly piezoelectric GaN film with a good surface morphology (RMS roughness =0.7 nm) was obtained on a 2-in (0001)-oriented sapphire substrate by MOCVD growth. The fabricated GaN SAW filter exhibited a very high velocity of 5803 m/s and relatively low insertion loss of -7.7 dB, The attenuation of the center frequency was about 22 dB smaller than those at the tops of the first sidelobes. When the wavelength of the IDT electrode was 60 μm (λ/4=15 μm), the center frequency was measured at 96.6 MHz, thereby facilitating a ~GHz operation when the IDT geometry is designed on a 1 μm scale. The calculated electromechanical coupling factor (K²) was about 4.3±0.3% which is larger than those obtained from other thin film piezoelectric materials and allows the realization of wider filter fractional bandwidths. TCF (temperature coefficient of frequency) was measured as low as -18.3 ppm/°C in the range from -25 to 50°C. These superior characteristics demonstrate that epitaxially grown GaN thin film can be successfully used for high performance SAW filters     

Fabrication of variable bandwidth filters using arrayed-waveguidegratings

Variable bandwidth filters have been fabricated using silica-based N×N arrayed-waveguide gratings. The centre wavelengths are λ₀=1.55 μm for all channels. The 3 dB bandwidths are 40, 78, 116 and 154 GHz, for the filter with a path length difference ΔL=63 μm. In the filter with ΔL=8.6 μm, the 3 dB bandwidths are 414, 769, 1198 and 1608 GHz. The on-chip losses are 2.1-2.9 dB and sidemode suppression ratios are larger than 27 dB     

A 3 V 10 MHz pseudo-differential SC bandpass filter using gainenhancement replica amplifier

This paper describes the design strategy and implementation of a high frequency low voltage pseudo-differential SC filter which use opamps with gain enhancement replica amplifier. Experimental results of a biquad SC bandpass with a center frequency of 10 MHz and a Q of 10 are presented. The realized opamp has an open-loop unity-gain bandwidth of 850 MHz, a phase margin of about 62°, and a dc gain of 50 dB. The prototype filter dissipates 23 mW from a 3 V supply and occupies 0.3 mm ² in a 0.8 μm N-well single-poly, double-metal CMOS process     

Proposal of a GaInAs/GaInAsP/InP antiguided filter laser arrayoperating in single longitudinal mode

The authors propose a type of in-phase lateral- and single-longitudinal-mode laser array, the so-called antiguided filter laser array (AFLA), in which an antiguided filter region is inserted between a positive-index-guided multiple-strip array region with a shallow corrugation grating and a high-reflectivity region with deep corrugation. Threshold current as low as 100 mA was obtained for a five-element laser array with active region length of 300 μm and total emitter width of 18 μm, using five-pairs of Ga_0.3In _0.7As (3 nm)/GaInAsP (10 nm) compressively strained quantum wells     

Two-frequency drive for AC-refresh plasma display panels

A new drive scheme, with mixed low- and high-frequency drives, has been developed for large-capacity (large number of dots) ac-refresh plasma display panels. Its usefulness for suppressing both firing-voltage increase and luminance-level decrease in a large-capacity panel was confirmed using a practical-size plasma panel. This drive technique can produce a large display panel ( > 400-600 scan lines) with about 50-percent lower power dissipation and higher luminance level than a conventional drive technique. It has been clarified experimentally that these results are due to the sufficient formation of the wall charge at an initial discharge period.     

Use of barium cold cathodes for low voltage DC-gas discharge color display panels

A technique for providing barium cold cathodes in a dc-gas discharge color display panels has been developed. A 21 × 111 cell green panel, fabricated in accordance with this technique, yielded a maintenance voltage of 88 ± 8 V. This value is approximately ⅓ that for conventional nickel cathode panels, resulting in a threefold increase in luminous efficiency.     

Display-device research and development in Japan

Current work on display devices in Japan is surveyed. Work on plasma display panels includes several methods for producing gray scale on ac-driven bistable panels, a technique for moving the display on an ac-driven panel, and new types of plasma display panels. Development on several types of alphanumeric displays, including both new and older types, is summarized. Work on light-emitting diodes includes new fabrication techniques and new types of devices. The liquid-crystal work described includes addressing techniques, color modulators, and light-addressed light valves. A new cathodochromic display tube, a high-frequency oscilloscope tube, and an electroluminescent display panel are mentioned.     

Preparation and characteristics of white EL display panels

Two methods for preparing white emitting EL panels are well known in principle: (1) blending a blue and an orange emitting EL phosphor and (2) partially cascading of green EL emission with a red photoluminescent material, typically an organic fluorescent dye. Both methods have their advantages and shortcomings. Panels containing phosphor blends are readily viewed even in moderately bright ambient light but the “ white” color is reasonably stable only over limited times because the blue phosphor comnonent deteriorates faster than the orange. Cascading panels show very long lives, depending on the green EL phosphor involved, without any visible color change but these panels can be used only under restricted ambient light conditions. Brightnesses and efficiencies of both kinds of panels are about comparable     

基于NV色心的晶体管放大器近场分布成像

微波毫米波芯片非破坏高分辨率近场分布成像对高频射频芯片的功能和失效分析至关重要.本实验基于金刚石NV（Nitrogen-Vacancy）色心这一独特的量子体系,选取直径约为14μm的金刚石样品,将其粘附于20μm直径的光纤锥形尖端,制备成高分辨、非破坏、微型化的探针,通过分析NV色心在微波场变化中的基态自旋演化规律,采用全光学的方法,一次性成像,获得芯片表面整体场分布.本文给出了氮化镓高电子迁移率晶体管的近场分布成像图,拟合出光学探测磁共振（Optically Detected Magnetic Resonance,ODMR）谱图以及Rabi谱图,并对成像结果进行了分析.这一系统具有高效、高分辨、高灵敏度、对近场干扰小等优势,有望为高集成度微波电路故障诊断、天线辐射剖面、微波集成电路电磁兼容测试等应用提供一种全新的方案.     

CMOS continuous-time current-mode filters for high-frequencyapplications

Design considerations for high-frequency CMOS continuous-time current-mode filters are presented. The basic building block is a differential current integrator with its gain constant set by a small-signal transconductance and a gate capacitance. A prototype fifth-order low-pass ladder filter implemented in a standard digital 2 μm n-well CMOS process achieved a -3 dB cutoff frequency (f ₀) of 42 MHz; f₀ was tunable from 24 to 42 MHZ by varying a reference bias current from 50 to 150 μA. Using a single 5 V power supply with a nominal reference current of 100 μA, the five-pole filter dissipated 25.5 mW. The active filter area was 0.056 mm²/pole. With the minimum input signal defined as the input-referred noise integrated over a 40 MHz bandwidth, and the maximum input signal defined at the 1% total intermodulation distortion (TIMD) level, the measured dynamic range was 69 dB. A third-order elliptic low-pass ladder filter was also integrated in the 2 μm n-well CMOS process to verify the implementation of finite transmission zeros     

InGaAs/InGaAsP MQW optical amplifier integrated withgrating-assisted vertical-coupler noise filter

A photonic integrated circuit with an InGaAs/InGaAsP multiple-quantum-well (MQW) traveling-wave optical amplifier and a grating-assisted vertical-coupler filter as a noise filter have been demonstrated. A fiber-to-amplifier/filter gain of ~0.5 dB and a 3-dB filter bandwidth (FWHM) of ~70 Å at 1.56 μm filter center wavelength have been achieved. This photonic circuit is potentially suitable as a building-block for preamplifier lightwave receivers or high-gain, high-power optical amplifiers which are essential for optical communication systems and lightwave networks     

Tunable wavelength filter using nano-sized droplets of liquidcrystal

An electrically tunable optical filter has been developed that uses a polymer containing fine droplets of nematic liquid crystal as the active cavity in a Fabry-Perot interferometer (FPI). This FPI filter, whose finesse was 62, had a free spectral range of 37 nm in the 1.55-μm range with a full-width at half maximum of 0.6 nm and a transmission loss of 2.4 dB. The polarization dependent loss was smaller than 0.17 dB. The transmitted peak wavelength decreased with an electric field. This resulted in a tuning range of 10 nm at 300 V. The switching time was about 370 μs     

A novel technology for a-Si TFT-LCD's with buried ITO electrodestructure

A novel process technology for a-Si TFT-LCD's with the buried ITO electrode (BI) structure was developed and applied to 10-in-diagonal LCD panels. By employing the BI structure, an aperture ratio of 29% was achieved in high resolution panels with a pixel size of 192 μ and the pixel defect density was reduced to about one third of the conventional structure. The defect reduction effect of the BI structure was also confirmed theoretically. The BI structure provides significant advantages for high-performance TFT-LCD's