Optical configuration and color-representation range of a variable-pitch dot matrix holographic printer

The optical system configuration and design of a dot matrix holographic printer that can create image grating pixels of variable size, arbitrary pitch, and discretionary angle on a photoresist plate are presented. With the capability to vary spot size, grating orientation, and grating pitch on the fly, this newly developed holographic printer can apply a prespecified color at each specific viewing angle. Diffractive images with various visual effects and the wide color range that are possible by use of this system are examined in detail.     

MakerBot3D打印机虚拟装配系统的设计与实现

目的满足新产品的研发、后期维护以及操作培训等方面的需求。方法选用型号为Makerbot Replicator2的3D打印机为例,通过实际测量在三维建模软件SolidWorks中进行精确建模,之后利用3dsMax进行模型优化,最后导入到VRP完成虚拟装配系统制作。结果该系统能够展示整个3D打印机的内外部结构和装配过程。结论将虚拟装配技术与3D打印机相结合,能够以数字化的形式呈现3D打印机的整体结构和功能,而不必再受客观条件的制约,为工业产品的设计、完善、维护和管理提供了一种崭新的方式,对市场现有的3D打印机具有一定的适用性。     

基于UV油墨的3D地形图呈现

根据地形图的特点及UV油墨快速干燥的特性,提出一种运用3D建模和分层设色的方法,并通过实验,完成了中国台湾省主岛部分3D地形图的打印.选择台湾省主岛部分等高线图,在图形处理软件中,根据其高程,提取多幅等高线矢量图;根据墨层厚度与打印层数的定量关系,得到实际海拔高度与打印层数的对应关系,再根据等高线分层设色原理,设计分层设色对应表,并设定适当的比例尺,确定打印方案;使用喷墨打印机,打印得到具有一定立体感的3D彩色地形图.实验结果表明：根据UV油墨快速干燥的特点,使用UV喷墨打印机,可以打印得到具有立体效果的3D彩色地形图.     

Color holography to produce highly realistic three-dimensional images

The 1964 publication by Emmett Leith and Juris Upatnieks [J. Opt. Soc. Am. 54, 1295 (1964)] introduced the possibility of using holograms to record three-dimensional (3D) objects. Since then, there has been an interest in creating display holograms, i.e., holograms primarily produced to show objects in 3D. More recently, full color holography has become a reality, which was predicted in the 1964 paper. To record a hologram in which both the 3D shape and the color of the object are accurately reproduced, at least three laser wavelengths are needed. By computer simulation of the holographic color rendering process, the required amount of laser wavelengths and their distribution within the visible electromagnetic spectrum have been investigated. The quality of a color hologram also depends on the properties of the recording material. The demand on a panchromatic material for color holography is described. Recording techniques for color holograms are presented as well as the future of color holography as the perfect 3D imaging technique.     

基于混合坐标系的FDM型3D打印机研制

传统FDM（fused deposition molding，熔融沉积成型）型3D打印机在打印倒体件的过程中需设置辅助支撑结构，打印完成后去除支撑结构，这会导致成型件的精度降低。为解决传统FDM型3D打印机存在的问题，设计了一种基于混合坐标系的FDM型3D打印机。将基于笛卡尔坐标系的运动方式转换为基于拟球坐标系的运动方式，由X-Z平面内的旋转运动、X-Y平面内的旋转运动和Z轴方向的直线运动组合成拟球坐标系内的运动，达到无支撑3D打印的目的。介绍了基于混合坐标系的FDM型3D打印机控制系统的硬件和软件设计。用传统FDM型和基于混合坐标系的FDM型3D打印机进行打印实验并作对比，结果表明在同等级精度硬件配置的情况下，基于混合坐标系的FDM型3D打印机可以实现更高的打印精度。基于混合坐标系的FDM型3D打印机创新性强、造价低，拥有自主知识产权，具有广阔的市场前景。     

纸张荧光增白剂对印刷色彩管理的影响探究

目的探究荧光增白剂对纸张印刷色彩管理的影响。方法选择2种300 g/m2定量的日本富士施乐彩激纸,一种含有荧光增白剂,一种不含荧光增白剂,使用KONICA MINOLTA C6000打印机输出色块,测量色彩管理前后2种纸张输入和输出色块之间的色差。对比2种条件下输出色块与输入色块的色差,分析荧光增白剂对不同阶调和墨层厚度的色块的输出影响,并探讨UV-cut滤镜对荧光增白剂的校正效果。结果在D50光源下,含有荧光增白剂的纸张较不含荧光增白剂的纸张输出颜色的色差大。荧光增白剂对中间调颜色的影响大于亮调和暗调颜色,对颜色的影响程度与亮度值呈正比,与墨层厚度呈反比。荧光增白剂对亮调颜色b值的影响大于暗调颜色,荧光增白剂对颜色的a值影响不大。结论含有荧光增白剂的纸张上输出的色域体积要小于不含荧光增白剂的纸张,对颜色的控制也较不含荧光增白剂的纸张差。使用UV-cut滤镜对荧光增白剂进行校正后纸张上输出色块的色差减小,对准确在纸张上进行颜色再现具有重要意义。     

窄色域抗打印扫描全息水印算法

目的为了提升水印抗打印扫描攻击的鲁棒性,提出一种窄色域抗打印扫描全息水印算法。方法制作打印机的ICC特性文件,应用特性文件转换宿主图像到CMYK颜色模式,从而获得适应该设备的窄色域,将制成全息图的水印嵌入到宿主图像的DWT域内。结果实验表明,该算法经历打印扫描后可顺利提取水印,且打印扫描后获得的水印图像保真度较高。与在RGB颜色模式中嵌入水印相比,该算法水印的鲁棒性和宿主图像的保真度均具有明显优势;相较于嵌入水印到默认转换的CMYK颜色模式,鲁棒性相当,该算法宿主图像的保真度具有明显优势。结论该窄色域算法可提升打印扫描过程中颜色传递的一致性,结合全息图不可撕毁的优势权衡了鲁棒性与保真度的关系,该算法有益于数字水印在防伪印刷领域的应用。     

一种Lab空间的色域边界描述算法

基于区域分割法,提出一种Lab空间的色域边界描述算法,以更精确地实现图像颜色映射到打印机色域。在Lab空间内,首先用色域边界描述(GBD)对打印机色域进行整体分割描述,然后根据图像每个像素点的色相角计算打印机的线性色域边界(LGB),最后比较图像每个像素点的L值与LGB矩阵L值区间的关系,确定像素点是否在打印机色域边界内。算法在GBD对打印机色域边界进行分割后,还面向图像每个像素点确定打印机的LGB边界,色域边界描述更加精确。实验仿真结果表明,该方法能够更精确、直观地实现图像颜色映射到打印机颜色。     

基于AR技术的激光打印机交互应用设计与开发

目的 针对激光打印机的使用、维护和培训等需求,探究AR技术在激光打印机的虚拟交互和工艺流程上的应用研究。方法 以三星M2876HN型号的激光打印机为研究对象,使用3ds Max 2018来制作模型和动画,通过Unity 3D配合Vuforia SDK开发AR效果的应用软件。结果 发布了移动应用,该应用可以实现对激光打印机的识别,展示激光打印机的内部结构、耗材的更换和内部运转动画,可以对模型进行旋转缩放和查看激光打印机的信息。结论 将AR技术和激光打印机相结合不仅为激光打印机功能展示提供了新模式,而且模拟了激光打印机使用过程的一些问题,增加了用户与激光打印机的互动体验。     

Phase volume holographic optical components for high-brightness single-LCD projectors

Projection systems based on liquid-crystal displays (LCD's) offer new opportunities to display high-definition and large-size TV images. There are two types of LCD projector architectures: the 3-LCD architecture uses one LCD for each primary color, red, green, and blue, whereas a single-LCD configuration employs only one LCD paved with color filters. The single-LCD projector is simple and compact but suffers from a poor luminous efficiency because of losses in the color filters: each filter transmits only ~1/3 of the flux emitted by the lamp. To increase this optical efficiency, we propose to introduce volume holographic elements in the architecture of a single-LCD projector. Innovative systems are presented in which volume holographic elements realize the spatiochromatic illumination of the LCD. This illumination consists of selectively directing all the light that corresponds to a primary color, red, green, or blue, in the pixel addressed with the corresponding video composite signal and exploits the spectral selectivity and dispersion properties of volume holographic gratings and lenses. The two main advantages of such illumination are the suppression of the color filters and the recovery of the light lost in a classical architecture by absorption of the color filters. A complete luminous efficiency analysis of spatiochromatic illumination with volume holographic elements is presented. The achieved performances are compared with classical single-LCD projectors.     

喷墨打印机颜色显色性的研究

通过对几种无光泽和高光泽彩喷纸的喷墨打印图像进行主观和客观评价,分析出市售打印机的显色能力和适用范围.从而有助于消费者根据自身需求,选择适合的喷墨打印设备,从而达到充分利用喷墨打印机资源的目的.     

基于CIECAM02色貌模型的数码相机色彩管理

为改进数码相机应用ICC色彩管理只考虑光源对呈色影响的缺陷,将色貌模型引入了数码相机色彩管理。在ICC色彩管理的基础上,用VC++开发了"从色度值到色貌值"的转换模型,以拍摄色貌值与显示色貌值颜色属性(色貌)一致为目标,利用软件生成并编辑了特性文件,应用色貌色差公式作为评价特性文件的标准,确定了3种典型光源(D65,D50,A)环境下,数码相机的特性文件,达到了人眼视觉上色彩的准确复制。     

液压式熏香3D打印机参数试验与结果分析

目的 研究了熏香3D打印机的初级试验参数,达到为后续优化和批量生产提供技术规范和数据支持的目的。方法 基于课题组前期设计试制的熏香3D打印机进行试验,通过试验分析挤出压力、打印速度、出料口与打印平台的距离、模型复杂程度、出料口直径、水料混合比等参数对熏香3D打印机的打印效果和打印效率的影响,分析研究影响熏香打印机的主、次参数。结果 挤出压力为0.4～0.6 MPa,打印速度为1800～2400 mm/min时,打印效果较好;出料口与打印平台的最适宜距离为10～12 mm。结论 挤出压力与打印速度是影响熏香成型效果的最重要的2个因素。     

Space-bandwidth conditions for efficient phase-shifting digital holographic microscopy

Microscopy by holographic means is attractive because it permits true three-dimensional (3D) visualization and 3D display of the objects. We investigate the necessary condition on the object size and spatial bandwidth for complete 3D microscopic imaging with phase-shifting digital holography with various common arrangements. The cases for which a Fresnel holographic arrangement is sufficient and those for which object magnification is necessary are defined. Limitations set by digital sensors are analyzed in the Wigner domain. The trade-offs between the various holographic arrangements in terms of conditions on the object size and bandwidth, recording conditions required for complete representation, and complexity are discussed.     

Phase-conjugate resonant holographic interferometry applied to NH concentration measurements in a two-dimensional diffusion flame

Resonant holographic interferometry is a diagnostic technique based on the dispersion of light having a frequency close to that of an electronic transition of a molecule. We propose a novel single-laser, two-color setup for the recording of resonant holograms and apply it to two-dimensional (2D) species concentration measurements in a combustion environment. The generation of the second color is achieved by optical phase conjugation from stimulated Brillouin scattering in a cell. The frequency shift of ~8.5 GHz introduced by the phase conjugation matches approximately the linewidth of many molecular transitions at typical flame temperatures and can be implemented to produce holograms of good contrast and diffraction efficiency. Phase-conjugate resonant holographic interferometry is demonstrated in a 2D NH(3) -O(2) flame, yielding interferograms containing information on the NH radical concentration distribution in the flame. Experimental results are quantified by application of a numerical computation of the complex refractive index.     

彩色全息的进展

本文介绍真彩色全息技术的进展，包括早期的彩色全息术，白光处理彩色全息术，透射彩色彩虹全息术，彩色傅里叶变换全息术，反射彩色全息术。阐述全息图的构成与再现过程，给出了这些技术的实验例证。     

Application of a photopolymer to a holographic reflector for reflective liquid-crystal displays

A photopolymer for fabrication of volume-type transmission holograms, which are used primarily on the holographic reflector for reflective LCD's, is reported. This photopolymer consists of bisphenol-type epoxy resin and an acrylic monomer with diaryliodonium salt and 3-ketocoumarin as a complex initiator. The chemistry of the imaging formation is based on the radical polymerization of the monomer initiated by a holographic exposure, followed by the cationic polymerization of epoxy resin by UV exposure after postexposure baking. The yellowish color of the hologram derivatives that resulted from the sensitizing dye and from the photospeed were improved to satisfy the specifications for the holographic reflector. The holographic reflector now gives brighter images.     

UV 喷墨打印机色域的研究

用Mimaki UV 喷墨打印机及UV 油墨进行了试验,以不同墨量输出和承印材料为变量,通过制作ICC 文件并比较色域图,讨论了不同墨量输出对各阶调范围的色彩再现性的影响,并分析了承印材料的偏色对色域范围的影响。结果表明,对于Mimaki UV 喷墨打印机,可通过在纸张上打印UV 白墨的方式来进行避免承印材料影响的色彩再现;可根据图像的阶调主要分布情况来选择输出墨量值。     

采用热转换新技术的彩色打印机

本文介绍了采用热转换新技术的新型彩色打印机,阐述了其种类、性能特点和发展前景,如：热腊打印机、固体喷腊打印机、染料热升华打印机、微干式打印机等。     

基于离散余弦变换的三维点云模型全息盲水印

目的 为保护三维模型版权, 提出一种基于离散余弦变换的三维点云模型全息盲水印算法。方法 对三维点云模型进行仿射不变性处理, 将三维模型由直角坐标系转到球坐标系, 并对球坐标中的角度值进行升序排序; 将顶点到质心的距离按顺序存入64×64的数组中, 作为水印嵌入对象; 二值水印图像经全息水印技术生成全息水印, 并对全息水印进行分块离散余弦变换, 在该变换域的中频部分实现对水印的嵌入, 再经过离散余弦逆变换, 实现由频域到空间域的变换, 生成带有水印的三维模型。结果 提出的算法是一种盲水印算法, 对一些仿射攻击具有较好的鲁棒性。将水印嵌在变换域的中频部分, 水印的不可见性及稳定性增强。结论 提出算法可成功获得水印信息, 采用全息技术实现了三维模型版权保护。