防伪电子票打印扫描过程中的数字水印失真和还原技术

数字水印失真和还原技术是当前信息保密的重要研究方向。通过介绍打印扫描数字水印技术,阐述了数字水印系统的基本框架、分类特征、典型算法和性能评估;通过对数字图像的打印扫描过程分析,介绍了连续色调方法基本模型以及扫描、打印过程对图像的影响,并对像素失真和几何失真进行了具体分析,同时提出了修正方法;最后从数字水印的提取和嵌入两个方面,设计了基于DCT的抗打印扫描数字水印系统,经过相关鲁棒性试验研究发现,设计的打印扫描数字水印系统具有良好的防伪和防篡改性能,与其他算法相比具有读取和嵌入速度快、误码率低的优点。     

Laser scanning microscopy

In conventional light microscopy, images are formed either by direct imaging of the object at a desired magnification or by imaging the object onto a remote surface and converting the illuminance at that surface to an electrical signal. In laser scanning microscopy, the object or specimen surface is scanned point by point by a focused laser beam. The actual image or other pertinent characteristic of the object is then generated by an electronic system. Use of such scanned laser systems exists today in biomedical research, in the semiconductor microelectronics industry, and in varied other industrial inspection applications. In this paper, we review the basic principles of laser scanning microscopy, discuss advantages as compared to more conventional light microscopy, and illustrate the technique with examples of systems in use today.     

Laser scanning for semiconductor mask pattern generation

The use of laser scanning to generate semiconductor masks is reviewed. Following a brief historical introduction that describes early pattern generator implementations, current and future industry mask requirements are described with the consequences for pattern generator design: the need for small features, tight CD control, and high pixel delivery rates. The system architecture of a current deep UV scanning system is described in detail along with important print strategies, such as grayscale printing and multipass error averaging. Several subsystem technologies are then explored with emphasis on the application to short wavelengths and multiple beams. Today, frequency-doubled lasers generate the 257-nm radiation used by DUV pattern generators; tomorrow, sum frequency generation will be required to reach the wavelengths at or below 200 nm. Acousto-optic modulation (AOM) technology is shown to scale favorably with shorter wavelengths and to have the bandwidth capability for future system. Acousto-optic beam deflection, polygonal mirror beam deflection, and the reduction of scan bow error through the use of an f /spl middot/ sin(/spl theta/) lens are examined. A section on scan optics and image formation presents the differences between partially coherent imaging as used by a wafer stepper and the incoherent superposition of Gaussian beams as used by a laser scanner. Partially coherent imaging is shown to have a sharper image slope but worse feature size linearity. This section also discusses the effect of finite AOM turn-on time on the aerial image in the scan direction.     

凸球面网栅激光直写技术

为了满足凹球面光刻所需的曲面网栅掩模的需求,建立了凸球面激光直接写入系统用于制作曲面网栅掩模。该系统目前支持最高20的基片倾斜,结合加工时的曝光量修正算法,在口径为50 mm、曲率半径为51.64 mm的凸球面基底上制作了矩形网栅图案,并结合双摆台联动在凸面上制作同心圆环图案。实验结果表明,现有凸球面直写系统初步具备加工凸面网栅掩模的能力,为后续的曲面掩模光刻打下坚实基础。     

Acousto-optic scanning multi-photon lithography with high printing rate

<正>As a manufacturing method that is focused on end-users,3D printing has gained a lot of attention in recent years due to its unique advantages in fabricating complex three-dimensional structures.Various new micro-nano 3D printing methods have been developed to meet the demand for high-precision and high-yield manufacturing^1-9.Among them,multi-photon-photon lithography(MPL) is a promising 3D nanofabrication technology due to its capability of true 3D digital processing and nano...     

无扫描物镜的激光扫描直径测量系统

系统由两个无扫描物镜的激光扫描单元构成,各单元相对独立的对工件进行测量,得到系列角度测量参数,智能仪表根据特定的测量公式计算出工件直径,系统便于安装调试,实用样机精度达±1μm。     

Frequency-spread associated with fast electronic scanning

It is shown that at fast scanning speeds the radar antenna beam contains frequency components other than the transmitted frequency, resulting in a frequency spread in the echo from a fixed target which is distinct from that arising from finite time on target.     

The absorption ink transfer mechanism of gravure offset printing for electronic circuitry

The gravure offset method has been developed toward an industrially viable printing technique for electronic circuitry. In order to obtain the optimum ink resin for printing lines of required thickness (>5 /spl mu/m) of narrow lines (down to 25 /spl mu/m), several ink resin systems have been assessed in previous studies by the authors. The best printed results were obtained with a novel ink using a hydrocarbon resin. This ink did not comply with the traditional ink transfer mechanism based on evaporation of the solvent, but with a postulated new "absorption mechanism.".     

电子部件的激光焊接

激光作为高功率密度光源可用于各种材料的加工，其在工业领域的应用包括汽车、钢铁、电器电子和半导体，主要用途是切割、焊接和打标。     

Compact ka-band bi-directional amplifier for low-cost electronic scanning array antenna

An innovative transceiver compaction technique is introduced to address the high manufacturing cost associated with a large-aperture phased array. Northrop Grumman Space Technology's bi-directional amplifiers are ideal for this application. The size, weight, and cost of the transceiver module is greatly reduced since only a single highly integrated monolithic microwave integrated circuit is required. The GaAs-based Ka-band bi-directional amplifiers are presented in this paper in both common-gate and common-source configuration.     

激光扫描共焦荧光显微镜的电子控制系统研究

介绍了激光扫描共焦荧光显微镜的电子控制系统，为了提高激光扫描器的定位精度，在系统中提出采用基于闭环象素时钟发生器的检流计振镜所固有的扫描非线性失真补偿方案，减少输出图象的枕形畸变，实现行扫描空间位置的均匀性。在以细分梯形波电流驱动反应式步进电机情况下，根据实测θｉ曲线，用反插法求得与步进电机运行非均匀性相补偿的相电流波，从而获得在小电流情况下高角度均匀的步进电机细分运行特性。     

激光扫描共焦荧光显微镜的电子控制系统研究

介绍了激光扫描共焦荧光显微镜的电子控制系统,为了提高激光扫描器的定位精度,在系统中提出采用基于闭环象素时钟发生器的检流计振镜所固有的扫描非线性失真补偿方案,减少输出图象的枕形畸变,实现行扫描空间位置的均匀性。在以细分梯形波电流驱动反应式步进电机情况下,根据实测θ-i曲线,用反插法求得与步进电机运行非均匀性相补偿的相电流波,从而获得在小电流情况下高角度均匀的步进电机细分运行特性。     

3D打印技术及其在电子元器件领域的应用

电子元器件是电子设备的基础与核心,对电子设备微型化、集成化的发展起到至关重要的作用,但传统的制造方法在提高电容器元器件功率密度和能量密度方面存在难以逾越的鸿沟。在电子元器件制造中引入3D打印增材制造技术不仅能够突破传统加工制造技术的瓶颈,还可以实现电子电路性能的提升和特性化制造,目前已成功地打印出了功能性电子组件和电路。因此,结合3D打印原理和打印方法的分析,并以3D打印固体钽电容阳极块为例,详细阐述3D打印技术在电子元器件领域应用的技术难点和解决方法,以示3D打印技术在电子元器件领域具有广阔的应用前景。     

激光扫描共聚焦显微镜在微孔隙研究中的应用

激光扫描共聚焦显微镜(laser scanning confocal microscope,LSCM)具有分辨率高、制样简单、具有一定穿透能力、集激光扫描和数字图像处理为一体等优点。用于研究储层中的微孔隙,其能够快速、准确、直观地提供微孔隙的孔隙结构与面孔率等信息,本文通过对致密砂岩粒缘微缝、砂岩长石粒内溶蚀孔、云母内微孔、火山凝灰岩脱玻化气孔和英安岩溶蚀微孔进行激光共聚焦三维扫描,可以检测出孔径在0.1μm以上的微孔隙,有助于分析微孔隙特征与油气集输之间的关系,对天然气储层和致密砂岩储层的勘探和开发具有重要意义。     

Laser printing of air-stable high performing organic thin film transistors

Active layers involved in top contact organic thin film transistors (TC-OTFTs) have been printed using the laser induced forward transfer (LIFT) technique. Bis(2-phenylethynyl) end-substituted terthiophene (diPhAc-3T) as a p-type organic semiconductor was vacuum evaporated on a quartz substrate prior to the transfer by laser onto an acceptor substrate to form an organic active layer for charge transport. The resulting printed diPhAc-3T pixels on the receiver substrates have a homogeneous morphology as shown by optical microscopy and atomic force microscopy (AFM). Electrical characterizations demonstrated that these transistors are fully functional with hole mobilities up to 0.04 cm²/V s, threshold voltage V_t near 0 V and I_on/I_off ratio up to 2.8 × 10⁵. The efficient cohesion of diPhAc-3T vacuum evaporated thin films induced by 3-dimensional growth offers an exceptionally high physical resistance to laser pulses. The large intermolecular interaction involved in such growth mechanism makes the thin films less sensitive to the mechanical damages induced by the laser. Due to the optical properties of diPhAc-3T, the use of a protecting layer deposited on the donor substrate prior to the diPhAc-3T active layer to trap the incident radiation during the LIFT was not required.     

活性钎焊电子浆料流变性能及丝印质量的研究

研究了固含量及有机载体对电子浆料流变性能及丝网印刷质量的影响。采用流变仪测量钎焊电子浆料的黏度和触变性,并结合丝印后形貌特征,通过优化电子浆料的配方来改善丝印质量,对后续烧结过程形成性能优良的陶瓷覆铜板三明治结构具有很好的指导意义。获得了优化的浆料配方为:固含量为质量分数89%,有机载体成分质量组成为:丙二醇苯醚溶剂93.53%,乙基纤维素粘结剂5.97%及LD-9108型流平剂0.5%。获得的浆料黏度为46.039 Pa·s,触变指数为2.6136。     

Multimotor electronic line shafts for rotary offset printingpresses: a revolution in printing machine techniques

In rotary offset printing presses, mechanical line shafts are being replaced by electronic shafts which consist of synchronized position and speed-controlled AC motors driving the complete printing units or single printing cylinders. The dynamic stiffness of the multimotor system to satisfy the requirements of high printing accuracy can be achieved by high-dynamic, cascaded current, speed and position control of the the drives, which can be combined with disturbance observers in critical cases, or by direct drive technology     

激光振镜直写光栅误差分析及校正方法

针对振镜式激光直写光栅系统中存在的扫描畸变的问题,提出了一种内部转角优化和外部扫描误差补偿相结合的校正方法。以光栅栅距10μm为目标,建立了振镜系统的几何光学模型,对扫描误差进行了分析,然后对振镜转角进行了优化,进一步对振镜进行了曲线拟合补偿,坐标点(100,10)处误差从0936mm,1912mm降低到0148μm,00296μm。结果表明,这种方法能够满足振镜式激光直写光栅在短距离刻划的精度要求。     

Laser and electron beam scanning of GaAs FETS

The results of work to study the effects of laser and electron beam stimulation of GaAs FETs are reported. Studies were made using biassed and unbiassed devices and also using devices with the gate removed by etching. Several mechanisms can be effective but the major cause of the very large induced drain current sensitivities is the photovoltaic effect of the beam on the interface between the semi-insulating substrate and the channel and consequent channel depth changes. A reduction in drain current on illumination observed under negative bias conditions is attributed to the presence of a surface channel on the semi-insulating substrate. The two methods of stimulation produce essentially the same results despite the large differences in charge and input energy. The implications for reliability analysis are discussed.