刻录世界因你而精彩

盘片根据记录及读取功能的不同,可以分为三类:只读型(CD、VCD属于此类)、可写入一次型(CD—R)、可重复擦写型(CD—RW)。 在容量上,盘片一般以74min/650MB、80min/700MB比较常见,74min/650MB、80min/700MB的意思是录制音频光盘或视频光盘,最高时间长度为74或80分钟,如果录制数据文件,盘片最大容量为650MB或700MB。读者可根据自己的需要来购买。 盘片根据颜色分为绿、蓝、金三种,其中最常见的是金盘和蓝盘。金盘的优势在于数据记忆体分子结构比较稳定,保存的时间比较长久。蓝盘最普通,价格也大众化。而绿盘虽然是第一个被发明出来的CD—R盘片,但是随着CD—R材料不断的进步,市面上己经很少看见绿盘了。     

光盘基础知识4 金属化工艺

溅镀后的模压盘片能够在播放器上读出,为确保读出信号的强度,需要溅镀金属层的反射率达到80％。从注塑机取出的透明盘片不能在播放机上播放,因为播放机的读出激光无法反射并返回读出探测器。为了能够播放,入射激光中的70％必须要返回探测器。这意味着透明盘片上需有一反射层,反射率至少为80％。因为大约10％的光在盘片和空气的界面上由于随机散射和损失而消耗掉。反射层的制作工艺称为金属化。有两种主要技术:蒸发和溅射,都要求在真空室内进行。蒸发是最早用于CD盘金属化的工艺。一批盘片放在一个架子上,然后装入一个大真空室中。抽气使室内压力降低,熔化的铝几乎沸腾,沉积在盘片的坑点表面形成铝层。沉积后,使室内压力升到大气压,取出盘片。只要非常薄(55～     

潮流驱动——谈谈笔记本电脑采用的DVD

1997年,东芝笔记本电脑率先在其TECRA 750DVD中选用了DVD驱动,推动笔记本电脑新的发展。DVD在存储、视听应用、音频方面部与CD-ROM有着显著的不同。虽然DVD盘片的外观和尺寸与现在广泛使用的CD盘片没有什么区别,但DVD盘片与CD盘片的结构是不同的。在CD盘上,纪录信息的最小凹凸坑长度为0.83um。各条光道间的间距为1.6um。而在DVD盘片的容量变成了CD盘片的7-20倍。为了进一步提高DVD盘片的存储容量,还采取了提高盘面利用率、减少纠错码长度、修改信号调制方式以及减少每个扇区字节数等措施,这使得DVD盘片的单面层容量高达4.7GB,是CD盘片容量的7倍多。由于DVD盘片的最小凹凸坑长度以及光道间距都比CD盘小得多,因此DVD的光拾取器(激光头)采用波长为625nm或650nm的短波长红色半导体激     

光盘常识 第1章:关于光盘

1.10.3 Blu-ray Disc更大的储存容量Blu-ray Disc(以下简称BD)在单面单层有23.3GB、25GB及27GB三种盘片,另外单面双层有46GB、50GB及54GB三种盘片,上述为可复写型;之后也发展播放用的只读型盘片BD-ROM(Blu-ray Disc ROM)。     

廉价的备份:CD-R

目前,CD-R(CD-Recorder)刻录机已经非常普及,价格电越来越便宜,制作自己的光盘已经不是遥不可及的事情了。为了更好地使用它,对CD-R盘片有一个全面的认识是十分常必要的。 一、CD-R盘片的基本结构 CD-R标准是飞利浦公司于1990年制定的。被称作橙皮书Part Ⅱ。CD-R技术目前应用非常广泛,由于其记录成本非常低.每兆字节不到3分钱。在数据备份与交换、多媒体应用、桌面出版等众多领域得到了广泛的应用。 CD-R盘片的片基与传统的CD盘片基本一样,但表层的“刻痕”不同。在传统CD片上有螺旋状的轨道(Track),而这些轨道又是由很多不连续的凹槽所组成,这些凹槽是用激光“雕刻”成的,又称之为“坑”(Pits),坑与坑之间的地方称为“岛”(Land)。在CD-R盘片上以连续的槽沟(Groove)取代“坑”,并组成螺旋状的轨道(Track),而“坑”就被记录在这些槽沟内。在空白的盘片     

光盘超容量刻录技巧

通常一张标称是4.7GB的DVD光盘可以容纳4.38GB的数据。当你要刻录的数据稍微超过了这个容量时,一张盘片不够,但用两张盘片,就显得非常浪费。此时,你可以试试以下方法,它能够帮助你将超容量数据刻录到一张盘片上。     

CD-R光盘常规检测参数和质量控制

10.串扰XT(Cross Talk):读出光斑直径总是大于CD-R盘片上预刻槽的宽度,而且光斑也不是强度均匀分布的几何圆,光斑的强度分布是高斯分布,通常所说的光斑直径是指高斯分布曲线的半高度的全宽度。事实上在光斑直径边缘甚至以外还是有光强分布的,只不过强度很弱而己。另外在预刻槽内刻录的信息凹坑往往也不只局限在槽宽范围内,凹坑可能扩大到槽边的岸区。这样读出光斑的边缘会覆盖相邻槽内的部分信息凹坑。这些相同频率范围的相邻槽内     

金属氧化铝半导体晶体管只读存贮器

最近,由于信息量不断增加,对计算机的大容量化、高密度、高速化、低成本的要求越来越高。为此,除了使用写入和读出重复性几乎相同的暂存器外,还研制成了只读存贮器,其用途是把固定信息多次重复读出,目前这种存贮器颇受重视。只读存贮器的特点是,写入时间此读出的取数时间长,写入用的外围电路简单,所以其造价低,而且由于只读出,故可缩短运算时间。只读存贮器不仅可做为数字表     

大同小异的刻录保护技术

在光盘刻录过程中遇到的最麻烦的事就是缓存欠载(Buffer Under Run)了一旦发生就会使盘片报废在刻录时数据一般是从硬盘或光盘通过IDE接口输入到刻录机缓存中然后由刻录机读出缓存中的数据并控制激光头进行刻录刻录过程中数据不能中断如果在刻录光盘时由于某种原因如打开应用程序接收网络传来的信息使CPU暂时停止资料传输去处理新的进程便会造成硬盘向刻录机缓存传输数据的中断一旦缓存中的数据用完得不到及时补充只要几秒的时间刻录盘就会因缓存欠载而报废以往为了避免缓存欠载用户在刻录时往往需要关闭所有的应用程序断开网络连接同时…     

HD DVD光盘格式的发展与信号处理技术

1、引言在光盘存储技术中,减小激光波长并提高物镜的数值孔径(NA:Numerical Aperture),可以有效的缩小聚焦光斑的尺寸,从而提高信息记录密度。HD DVD采用了405nm的激光波长和0.65的数值孔径,以及数值孔径为0.65的聚焦物镜,因此其记录密度显著高于传统的DVD。对于单面单层的HD DVD光盘而言,只读型HD DVD-ROM与可录型HD DVD-R的盘片容量为15GB,而可擦写型HD2DVD-RAM的盘片容量为20GB。与当前使用的DVD(单面单层盘片容量4.7GB)相比,HD DVD的容量增长达到3倍以上。另一方面,随着激光波长的减小和物镜NA值的提高,由光盘和…     

Integration of optical waveguide on pneumatic balloon actuator for flexible scanner in endoscopic imaging diagnosis applications

This paper reports a flexible scanner consisting of a scanning actuator and optical waveguides for medical imaging applications such as endoscopic fluorescence imaging diagnosis. The 0.3-mm-thick and 5-mm-wide functional scanner was designed to be smaller enough than the 10 mm-diameter of channel of endoscope. The proposed device can be used to introduce an excitation light into the abdominal cavity or digestive tract. A pneumatic balloon actuator (PBA) consisting of polydimethylsiloxane (PDMS) is used as the scanning actuator for the scanner in consideration of its small, soft, and safe features. The SU-8 optical waveguides with high refractive index (n_SU-8 = 1.575) are integrated onto the PBA structure made of PDMS with a lower refractive index (n_PDMS = 1.405). Excitation light at a wavelength of 405 nm is transmitted through an optical fiber to the SU-8 waveguides. The outgoing light from the waveguide can be scanned by the bending motion of the PBA. The waveguide functions as a detector as well. Our developed device has successfully scanned, excited, and detected light from fluorescence beads at a wavelength of 540 nm distributed in a pseudo-tissue.     

Design of optical path of pickup for small form factor optical disk drive

We designed an optical path of pickup for the small form factor optical disk drive that is compatible with Blu-ray Disc format using 405 nm wavelength laser, 0.85 NA objective lens, and the 0.1-mm thick cover layer. The optical path consists of a high NA objective lens, a micro compensatory lens that is fabricated by micro-molding process, three reflective mirrors and a partial mirror. The optical performance of the optical path is analyzed and the expected yield ratio is calculated for 22 tolerance parameters by using Monte Carlo method. Finally, the micro compensatory lens is fabricated by micro-molding process.     

The hydrocarbon molecules concentration remote measurement by lidar with the diode lasers

Lidar systems for the pollution molecules concentration remote measurements in the atmosphere can become a basis for the atmospheric air quality controlling systems and the emergency pollution emissions prediction in the atmosphere under the industrial enterprises. The Raman lidar potential possibilities estimation with the diode lasers for the hydrocarbons molecules sensing in atmosphere for such molecules concentration level detection in atmosphere over industrial region and above is the present paper goal. The Raman lidar equation computer simulation results show the possibility of the optimal laser radiation wavelength choosing for the hydrocarbon molecules sensing in atmosphere in the photon-counting regime and these molecules concentration level exceeding over the given level in the distance range from 10 m up to 1 km. The 405 nm diode laser radiation was the best result wavelength with the minimal detection time value of 180 ms for the pentane molecule at the ranging distance of 1 km in the photon-counting Raman lidar regime.     

A minimal lattice realization for multivariable systems

An algorithm for constructing a minimal lattice realization of a multivariable stable linear discrete-time system is proposed. The algorithm consists of four steps: (i) realize the objective system in an input normal Hessenberg form, (ii) construct an LBR system associated with the objective system, (iii) construct a lattice realization of the LBR system from its input normal Hessenberg realization, (iv) transform the lattice realization of the LBR system into one of the objective system.     

Robust estimation of surface properties and interpolation of shadow/specularity components

The Polynomial Texture Map framework (PTM) extends the simple model of image formation from the Lambertian variant of Photometric Stereo (PST) to more general reflectances and to more complex-shaped surfaces. It forms an alternative method for apprehending object color, albedo, and surface normals. Here we consider solving such a model in a robust version, not to date attempted for PTM, with the upshot that both shadows and specularities are identified automatically without the need for any thresholds. Instead of the linear model used in few-source PST for Lambertian surfaces, PTM adopts a higher degree polynomial model. PTM has two aims: interpolation of images for new lighting directions, and recovery of surface properties. Here we show that a robust approach is a good deal more accurate in recovering surface properties. For new-lighting interpolation, we demonstrate that a simple radial basis function interpolation can accurately interpolate specularities as well as attached and cast shadows even with a medium-sized image set, with no need for reflectance sharing across pixels or extremely large numbers of interpolation coefficients.     

Spectroscopic determination of wheat water status using 1650-1850 nm spectral absorption features

Wheat leaves were measured radiometrically in order to spectrally characterize the water deficiency symptoms. In this study, a FieldSpec-FR was used for measuring wheat leaf spectra. After the spectral analysis using a spectral normalizing technique, the spectral absorption feature parameters: wavelength position (nm), depth and area (relative value) were extracted from each wheat leaf spectrum. The relative water content (RWC) was measured for each wheat leaf sample. A linear regression analysis was conducted between the spectral absorption feature parameters and corresponding RWCs. The experimental results from 110 samples indicated that reflectance spectra of wheat leaves in the 1650-1850 nm region were dominated by water content. With a decrease in wheat leaf RWC, the 1650-1850 nm spectral absorption features gradually become obvious. The relative errors of predicted RWCs and the absolute error of predicted wavelength positions were calculated from 12 validation samples by established regression equations. The relative errors of predicted RWCs and the absolute error of predicted wavelength position (nm) were both low (<6% for RWCs by the depth and area and <12 nm for the wavelength position, respectively). Furthermore, we discuss the potential and limitations of spectroscopic determination of wheat RWC by using remote sensing technology.     

ERD analysis method in motor imagery brain–computer interfaces for accurate switch input

Motor imagery brain–computer interface (MIBCI) can control computers using MI. However, input accuracy is low, partly owing to individual variability in event-related desynchronization (ERD) detection among different subjects. In an earlier study, we determined that using a max power in the mu-band method, i.e., the peak trace method (PTM), is effective for ERD detection. In this study, we compare the PTM to the band power method to determine the most effective method for ERD detection during MI tasks. Experimental results indicate that we could detect ERD using the PTM; however, MI-state estimation was difficult. We also found that the PTM might be effective for ERD detection in subjects with MI experience.     

Not So Naive Bayes: Aggregating One-Dependence Estimators

Of numerous proposals to improve the accuracy of naive Bayes by weakening its attribute independence assumption, both LBR and Super-Parent TAN have demonstrated remarkable error performance. However, both techniques obtain this outcome at a considerable computational cost. We present a new approach to weakening the attribute independence assumption by averaging all of a constrained class of classifiers. In extensive experiments this technique delivers comparable prediction accuracy to LBR and Super-Parent TAN with substantially improved computational efficiency at test time relative to the former and at training time relative to the latter. The new algorithm is shown to have low variance and is suited to incremental learning.     

大功率脉冲激光光斑面积的实时控制系统

讨论了大功率脉冲激光光斑面积的实时检测与控制方法,研制了采用波长532 nm的连续激光器和CCD—FPGA技术来脉冲激光光斑面积实时控制系统。实验分析了本系统的技术特性:激光光斑、CCD视频信号以及二值化信号;CCD视频信号二值化阈值为405 mV,而FPGA的控制误差范围为十进制数24;计算及标定激光光斑面积,光斑面积测量的相对误差最大为0.5%,而绝对误差在8μm2范围内。本系统可以直接应用于激光微抛光的能量密度实时控制。     

关于概率无限寄存器机器PURM及其程序可模拟的随机函数

本文给出了一种新的随机计算的机器模型:概率无限寄存器机器PURM,它比概率Turing机(PTM)更为简单。我们证明了PURM程序与可计算的PTM之间的等价性。基于对PURM程序的构造,我们给出了随机函数可被PURM程序或可计算的PTM模拟的充分条件。最后,讨论了PTM和PURM的一些简单性质。