最新刊期
期 3 ， 2012
- 摘要：Using the fully-leaky waveguide technique, the inverse twisted nematic (ITN) negative liquid crystal cell is investigated. The intensity of reflected light dependent on the internal angle through the fully-leaky liquid crystal waveguide geometry is obtained from experiment with various voltages. Compared with theoretical result, some parameters of liquid crystal material and liquid crystal cell are determined, and then the information of liquid crystal director within the liquid crystal cell is also obtained.关键词：fully-leaky waveguide technique;inverse twisted nematic;negative liquid crystal;director
- 20
- |
- 24
- |
- 1
发布时间：2020-08-12 - 摘要：The conception of Bernard effect and cholesteric liquid crystal texture are introduced. The sample of cholesteric liquid crystal in planar texture is prepared, the texture change with temperature field by polarizing microscope is observed. The Bernard effect or pane grate effect under the cleaning temperature is appeared. The experimental phenomena show that the temperature field induced the liquid crystal molecule convection, the birefringence interference is occurred, and liquid crystal director distribution is periodical variation, so that the microcosmic Bernard effect pattern formed. The experimental phenomena wait for explanation rightly, and have some significance for liquid crystal physics basic research.关键词：cholesteric liquid crystal;Bernard effect;pane grate effect;planar texture;polarizing microscope
- 19
- |
- 16
- |
- 1
发布时间：2020-08-12 - 摘要：The anisotropy DΔ of rubbed polyimide film for In-Plane-Switching(IPS) liquid crystal alignment was measured by reflection ellipsometry under the varied conditions of rubbing and imide temperature. It is showed that DΔ decreases with increasing imide temperature under the same rubbing condition. The penetration depth and the roll rotation speed play a key role in DΔ value. Therefore, DΔ value not only can be used as a quantitative evaluation method for rubbed film, but as a process control method for stable orientation of liquid crystal.关键词：IPS;liquid crystal;polyimide film;optical anisotropy;rubbing;reflective ellipsometry
- 32
- |
- 31
- |
- 3
发布时间：2020-08-12 - 摘要：Carbon nanometer ball films were deposited on Si (100) by microwave plasma chemical vapor deposition. The structure and surface morphology of carbon nanometer ball films was investigated by using Raman spectroscopy and field emission scanning electron microscope. The carbon nanometer ball film was composed of large numbers of about 2~3 μm-length and 100 nm-width amorphous carbon sheets which were intertwined and interwoven with each other into a ball. The field emission testing of carbon nanometer ball films was performed in a high vacuum system, and good field emission properties with a threshold field of 3.1 V/μm and a current density of 60.7 mA/cm2 at an electric field of 10 V/μm were obtained from the carbon films. A three electric filed model was applied to explaining reasonably the field emission characteristics of carbon nanometer ball films in the low, middle and high electric field region.关键词：microwave plasma chemical vapor deposition;carbon nanometer ball films;field emission
- 14
- |
- 12
- |
- 1
发布时间：2020-08-12 - 摘要：A new crystallization method is proposed for poly-Si thin film transistors by Ni silicide induced lateral crystallization. The poly-Si thin films were characterized by micro-Raman spectroscopy, auger electronic spectroscopy and atomic force microscopy. The poly-Si thin film transistor is also fabricated using this poly-Si as active layer. And the electrical properties are obtained from ID-IG transfer curve measurements. Compared with the thin film transistor prepared using conventional Ni induced lateral crystallization method, the fabricated poly-Si thin film transistor showed lower leakage current and higher field-effect mobility. It was attributed to the reduction of Ni concentration in the poly-Si channel. Also, the trap states in grain boundaries were decreased.关键词：Ni silicide;metal induced lateral crystallization;poly-Si thin film transistors
- 19
- |
- 16
- |
- 0
发布时间：2020-08-12
Material Physics & Chemistry
- 摘要：A bottom emitting organic light-emitting devices was fabricated by depositing Alq as capping layer to the glass substrate.The device structure were Glass/Alq(x nm)/Al(15 nm)/MoO3(30 nm)/ NPB(60 nm)/Alq(65 nm)/LiF(1 nm)/Al(150 nm). By studying the radiation characteristics of the devices, it was found that the variation of the EL emission due to the capping layer can be entirely accounted for a change in optical interference effects.The complex interplay between wide-angle and multiple-beam interference can be controlled via the optical thickness of the dielectric capping layer on top of the cathode.Semitransparent Al film was anode.The capping layer deposited to the glass substrate formed microcavity devices with cathode.By changing the thickness of capping layer to adjust the microcavity length, the center wavelength EL spectra of OLED was red-shifted.关键词：OLED;capping layer;interference;microcavity
- 25
- |
- 22
- |
- 4
发布时间：2020-08-12 - 摘要：Organic thin film transistors based on Weak Epitaxy Growth (WEG) technology are fabricated with two different design: top-gate and bottom-gate configurations. The active layer materials of the OTFT are p-6P and vanadyl phthalocyanine (VOPc). The two structural OTFTs are prepared under the same process conditions, and it is found that the device performance is different. The mobility of top-gate OTFT is much higher than that of the bottom-gate OTFT. A high mobility of 1.6 cm2/V穝 is obtained in the top-gate structure. The differentiation of top-gate and bottom-gate OTFTs is studied by Weak Epitaxy Growth (WEG) technology, and the reasons of higher mobility OTFT based on the top-gate configuration is explained.关键词：organic thin film transistor;top-gate configuration;weak epitaxy growth;VOPc
- 22
- |
- 20
- |
- 3
发布时间：2020-08-12 - 摘要：A critical backlight luminance method to get balance between clipping artifacts and power consumption in local dimming LCDs is proposed. Firstly, the critical backlight luminance of middle backlight blocks and edge backlight blocks are computed with different process. Then the critical luminance is compared with the backlight luminance computed by conventional method, and the larger one is selected as the ideal backlight luminance for superimposing luminance. Finally, the gray-scales after liquid crystal compensation can be obtained according to the superimposed backlight luminance. The experiment results with 81 cm(32 in) LED backlight show that clipping artifacts ratio is reduced effectively and power consumption is not increased obviously.关键词：critical backlight;clipping artifact;backlight dimming;LCD
- 20
- |
- 22
- |
- 3
发布时间：2020-08-12 - 摘要：A linear mathematical model is established to describe LED displays’ colors accor-ding to LED’s optical characters and the the pulse width modulation method of LED displays’ control system. Furthermore, the mathematical model is connected with the visual perception in CIE1976LUV color space. This paper analyzed the relationship between visual perception and accuracy requirement of control system when the neighbouring gray levels and neighbouring colors of LEDs are discussed. Moreover, to calculate the control system’s accuracy according to visual perception, the uniform problems of LED are discussed. This paper gives an algorithm to calculate the systemic accuracy of LED displays based on visual perception. With the algorithm, it is possible to design and optimize the LED displays’ control system according to visual perception before the LED displays are produced.关键词：LED displays;color difference;visual perception;systemic accuracy
- 19
- |
- 21
- |
- 3
发布时间：2020-08-12 - 摘要：The model of multimedia flat display system was studied. The paper proposed to the design technology of the flat display system which integrates multimedia, touch panel, wireless communication,camera and GPS navigation function. It develops the technology to implement these functions. In this project, power sub-system,audio,multimedia process,video, memory and other circuit module are designed;and the system level,kernel level and application software is developed. The designed project has been improved and verified. It shows the product meets the specification requirement.关键词：flat display;image processing;interface technology;device driver
- 14
- |
- 14
- |
- 0
发布时间：2020-08-12 - 摘要：μC/GUI has been widely used in embedded products provided with graphical interface.Based on LPC214X for embedded hardware development platform,this paper introduces a graphics supporting software used in embedded application——μC/GUI,generalizes its function and character, puts a key research on transplantation of μC/GUI. The transplantation of the μC/GUI interface function and the configuration files is realized, and a specific realization steps and source codes need to be modified are given.关键词：embedded system;μC/GUI;liquid crystal display;LPC214X
- 14
- |
- 14
- |
- 2
发布时间：2020-08-12
Device Physiscs & Device Technology
- 摘要：A servo-controller is designed based on the MCU chip C8051F120 and CPLD chip EPM570T100, the controller has LCD display and menu display through UART setting, and the real-time control information could be displayed on the LCD screen. The hardware structure and software flow design of the controller has been given. The experiment proved that the display module has the advantages of stable display and faster refresh rate, and satisfied the requirement of real-time display of the servo control system.关键词：C8051F120;LCD;servo-control;real-time display
- 13
- |
- 13
- |
- 2
发布时间：2020-08-12 - 摘要：A display driving module based on the Field Programmable Gate Array(FPGA) with LCD driver ICs was designed by the research of the 17.8 cm(7 in) AMOLED. The program is designed with Verilog HDL. By studying the characteristics of OLED display, the LCD driver ICs is chosen to fit it. A method connecting screen with ICs is present. Through using double data-driver and changing the polarity of the ICs, the problem that dot inversion of LCD Driver ICs is not matching AMOLED is resolved, and the brightness is doubled. For the data driver IC can only receive 6 bit/pixel data, but lost 2 bit data, this paper introduced the digital halftone technique. Using dynamic Bayer dithering algorithm on the low 2-bit input data to compare, and the treatment results is fed back to the high 6-bit data. Thus the output image quality is improved.关键词：AMOLED;driving;FPGA;Bayer dithering
- 19
- |
- 19
- |
- 5
发布时间：2020-08-12 - 摘要：In traditional industrial control applications,Industrial Personal Computer (IPC) and LCD display is widely used,because of high-performance graphics cards in IPC.It is very convenient to design a human-computer interaction interface. However,in aerospace applications where real-time performance and reliability is most important, graphics and display integrated in LCD module is usually required to reduce the burden of processors and to improve the real-time performance of systems.This paper focuses on how to use FPGA to draw 2D graphics (including drawing point, drawing a line, circle, ellipse)that is based on Bresenham algorithm, and display dot matrix characters and bitmaps on the LCD screen,it also proposes a series of strategies about how to optimize display performance. Through simulation and practical application in a product, this LCD module based on FPGA is stable, and has good performance.It can be used in aerospace applications.关键词：graphics and characters accelerate;LCD display module;FPGA
- 13
- |
- 15
- |
- 2
发布时间：2020-08-12 - 摘要：The de-interlaced scan input signal is easy to produce line image sticking in TFT-LCD. This paper researched the relationship between line image sticking with the drive signal. The result shows that line image sticking can be reduced by changing the polarity inversion mode of drive signal. At the same time by adding the pre-charge and controlling the TFT current ratio of Ion/Ioff, the flash problem brought by changing drive signal could be resolved. The research established the solution and theoretical basis for line image sticking.关键词：TFT-LCD;line image sticking;polarity inversion;pre-charge;flash
- 154
- |
- 104
- |
- 14
发布时间：2020-08-12 - 摘要：This paper introduces the design and implementation of LCoS field-sequential-colour (FSC) display driver system. The driver system uses FPGA as main controller, and uses two high speed DDR2 SDRAM to store image data. By means of regarding one frame image as a process unit, the driver system convert parallel input RGB signal into three series output homochromy image. By coordinating the driver system with the optical projector, FSC display on LCoS with the resolution of 800?600 is realized.关键词：LCoS;FSC;FPGA;DDR SDRAM
- 20
- |
- 16
- |
- 1
发布时间：2020-08-12 - 摘要：Development of the research on power LEDs’ quantum efficiency droop was investigated. Several LED products with different performance of high power operation were compared. Due to the improvement of the LEDs’ efficiency dependence on the driving current, their operating current corresponding to the maximum efficiency are exceeding their rating values. Under this circumstance, a driving strategy by rectangular pulse is proposed. In the driving circuit, the MOSFET’s gate was controlled by an intermittent waveform of PWM pulse series which is generated by modulating the rectangular pulses at lower frequency (200~800 Hz) on those at higher frequency (~40 kHz), whereby an approximately rectangular waveform at the lower frequency of the current pulses can be obtained by filtering the high frequency components. The peak current and duty ratio of the output drive to the loaded LED were correlated to maintain the constant drive current in average while the operating current was regulated to reach the maximum efficiency of the loaded LED.关键词：high power LED;pulse drive;efficiency droop;maximum efficiency;LED backlight source
- 17
- |
- 16
- |
- 1
发布时间：2020-08-12
Driving & Controlling
- 摘要：The environment influences to shipborne optical-electronic equipment such as carrier swaging,weapon shaking,fog or atmosphere,cloud and mist,wave of sea,it can result in tracking failure. According to this phenomena, a full information system that can offer high precision second lead to servo and control LOS to track ultralow-altitude target is manufactured. CA model,limited memory least-squares filter and the technology of " Approximate-comparative" ultralow-altitude are combined,then tracking ultralow-altitude target and offering angle information of losing target to servo especially called full information strategy is introduced. The designing and accomplishing of hardware platform are discussed in the text. The experiments prove that the full information system not only offer the information provided by outer system and feedback the data provided by shipborne Optical-electronic equipment to outer system,but also offer second lead data to servo system,the precision of data is advanced 11.8' to radar for 6 s.The model has the ability to control LOS to track ultra low-altitude target.It carries out a no-man guard and automatic shipborne optical-electronic equipment.关键词：CA model;full information system;ultralow-altitude;shipborne optical-electronic;"approximate-comparative"
- 19
- |
- 18
- |
- 3
发布时间：2020-08-12 - 摘要：Due to a CCD and ADC restriction, the dynamic range of the commonly used image sensor is only about 60 dB,which does not coincide with the dynamic range(110 dB)of eyes,leading to the loss of partial details of the image. In this paper, an image extended dynamic range technique based on the wavelet transform would be proposed. By means of taking pictures of the same scene repeatedly, the source images of different exposure time were procured, which were further divided into high frequency part and the low frequency part by using multi-scale wavelet transform. The method based on human visual gray recognition features was applied to the processing of low frequency part. By using different weights for processing, the most background information possible of the image was retained. For the high frequency part, the local maximal variance criteria for fusion was used to maintain the image edges’ characteristics to the greatest extent. Reconstruction is proceeded by using inverse wavelet transform to the merged high frequency part and low frequency part. Test results showed that comparing the reconstructive image and moderately exposed image, the details of information in the high brightness area and low light area was recovered, and the dynamic range got significant expansion.关键词：dynamic range;wavelet transform;image fusion
- 16
- |
- 12
- |
- 11
发布时间：2020-08-12 - 摘要：According to DCT coefficient characteristic of image and the threshold of the human eye to distinguish colors and chromatic aberration, a color image compression technique scheme was proposed based on the chromatic aberration. In the program, color images were transformed into the device-independent CIELAB color space firstly, and were transformed by DCT and their chromatic aberration was calculated. Then the images were quantified selectively by color aberration threshold of the human eye, and were coded by Huffman algorithm. Finally the images were decompressed by the above inverse process. Through simulation experiments, the results showed that reconstructed color images after decompression were almost the same as the source image, that the PSNR of the brightness images decompressed of each component were more than 30 dB, and that the human eye could hardly tell their difference. The five parameters values measured the coding quality were better, and the compression ratio of color image can be achieved 107.167 8 in case of ensuring the decompression image quality, which fully met the demand for color image compression. Comprehensive results showed that proposed image compression technology scheme color based on chromatic aberration was a viable, good color image compression technology.关键词：image compression;chromatic aberration;discrete cosine transform;redundancy
- 17
- |
- 15
- |
- 4
发布时间：2020-08-12 - 摘要：Aiming at the problem that traditional Meanshift algorithm can not guarantee tracking accuracy in certain interference or occlusion case and background pixel in object model will induce localization error,a improved targets tracking algorithm based on Meanshift algorithm was proposed. Firstly,the object model is improved by introducing weights which is decided by divisional degree between object and background,and then the weight was used in object model to reduce the localization error of object tracking. Secondly, the target in the tracking window is divided into a number of fragments, the improved Mean Shift algorithm is used in every fragments separately. Finally, the match degree of each fragment is computed and the fragment with the highest match degree is involved to achieve the whole target’s coordinates and to avoid the influence of occluded fragments on the object location. Experimental results show that the new method can effectively and accurately track moving target in the cluttering background.关键词：Meanshift;target tracking;fragments;anti-occlusion
- 23
- |
- 69
- |
- 12
发布时间：2020-08-12 - 摘要：In order to make a comprehensive evaluation on a head mounted display (HMD), a simple and feasible testing method is proposed and an optical system for the test is specially designed. According to the requirement of pupil engagement for the HMD and the testing system, a structure of eyepiece is adopted in the optical design, and a plastic aspheric lens is used to realize the distortion-free property. The designed optical system has a field of view of 50?, a pupil size of 4 mm and a distortion less than 0.1%. It can keep high performance when the testing HMD is with diopter from -4 D to 3 D. The analyses on the design show that the evaluation system can satisfy the evaluation requirement of HMD with various diopters.关键词：head mounted display;evaluation system;eyepiece;optical design
- 12
- |
- 15
- |
- 0
发布时间：2020-08-12 - 摘要：In order to achieve the target of man-made space real-time identification, this paper proposes a method of man-made spacecraft visual target detection and identification. In this method, because of the same relative position of the stars, by using image registration and intelligent frame difference method, the stars are removed. Then by distinguishing the different profiles of the natural and man-made star, the man-made stars are separated from nature stars. Therefore, the goal of man-made satellites dynamic recognition is achieved. Experimental results show that the proposed method compared with traditional methods, the amount of operations is reduced by about 30%, reliability has been improved. And it has practical significance in engineering practice.关键词：image recognition;object tracking;image segmentation
- 13
- |
- 12
- |
- 2
发布时间：2020-08-12
Imaging Technology & Image Processing
- 摘要：The industry development of television display techniques and industry in domestic and international societies is facing a very fierce competition. From the standard point of view, many methods including literature investigation, scientometrics analysis, clustering analysis, regression calculating and so on are used to compare and study standard kinds, industrial techniques,standard quantities, standardization products, standardization methods and theirs developing based on television display technical standards in Europe and China. Further, the current status of television industrial development with domestic and international society is analyzed. So it is suggested that the standards of the new techniques such as 3D display, network television should be developed as soon as to protect our new TV display technology industries and then should be promoted up to international standards.关键词：TV display;industries;standards;scientometrics
- 17
- |
- 19
- |
- 0
发布时间：2020-08-12
Industrial Technology Standard Trend
- Address：No.3888 Dong Nanhu Road, Changchun, Jilin, China 130033 Postal code：130033
- Tel：0431-86176059 Email：yjxs@ciomp.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 吉ICP备11002662号-17
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0