全景环形成像的转像系统设计

在全景环形透镜成像系统的设计中,为保证增大角视场情形下的成像性能,通过对全景环形透镜的第二反射面与第二折射面的几何参数间的有效平衡,以及对转像系统的优化设计,增大了成像视场,实现了全景环形透镜成像系统前后组之间的像差补偿;设计了一套具有良好成像性能的全景环形成像的光学系统。

目视医用硬性内窥镜光学系统初始结构设计

本文系统的阐述了目视医用硬性内窥镜光学系统初始结构设计,讨论了内窥镜光学系统的成像原理,硬性内窥镜物镜、转像系统以及目镜的一般结构考虑,结合视放大率公式,计算了一种腹腔镜的物镜、目镜以及转像系统的外形尺寸,并给出了该腹腔镜的设计结果。

潜望高度变化对潜望镜性能的影响

对潜望镜及改变双透镜转像系统间的间隔来实现潜望高度的改变进行了简要说明,并对转像系统间隔变化对整个系统性能可能产生的影响,进行了分析及计算。

XDS—1型倒置生物显微镜研制

提出一种使用方便，按人体工程学显微术需要而设计的显微镜．该仪器可满足用户对需染色的标本和不能染色的活体标本观察的需要，扩大了显微镜的使用领域．

A Study of Different Unwarping Methods for Omnidirectional Imaging

Omni-directional imaging system is becoming more and more common in reducing the maintenance fees and the number of cameras used as well as increasing the angle of view in a single camera. Due to omni-directional images are not directly understandable, an approach namely the un-warping process, has been implemented in converting the omni-directional image to a panoramic image, making it understandable. There are different kinds of methods used for the implementation of this approach. This paper evaluates the performance of the 3 universal un-warping methods currently applied actively around the world in transforming omni-directional image to panoramic image, namely the pano-mapping table method, discrete geometry method （DGT） and the log-polar mapping method. The algorithm of these methods will first be proposed, and the code will then be generated and be tested on several different omni-directional images. The images converted will then be compared among each other and be evaluated based on their performance on the resolutions, quality, algorithm used, complexity based on Big-O computations, processing time, and finally their data compression rate available for each of the methods. The most preferable un-warping method will then be concluded, taking into considerations all these factors.

A Flexible and High Speed Digital Scan Converter for High Frequency Ultrasound Imaging

This paper presents a flexible and high speed digital scan converter (DSC) with the ability to handle high frequency ultrasound imaging in real-time. The characteristics in imaging system such as focus length of transducer, the swing radius and sampling length etc. could be changed easily in compliance with the researcher's application based on this flexible digital scan converter. Linear interpolation is employed to achieve the coordinate transformations algorithm. Custom-built software is programmed to preliminarily handle the algorithm according to different ultrasound imaging applications. High performance FPGA will implement high speed interpolation calculation based on the preliminary data which are stored in the DDR2 SDRAM from the software. 64 bit 66 MHz PCI is employed to accomplish high speed data transmission. Experiment has shown that more than 500 frame rate could be achieved based on this high speed digital scan converter. The designed flexible and high speed digital scan converter could be used in current FPGA based high frequency ultrasound imaging system.

合成孔径激光成像雷达(Ⅲ):双向环路发射接收望远镜

提出了一种用于合成孔径激光成像雷达的双向环路结构的发射接收望远镜,双向环路包括发射4-f转像系统、接收4-f转像系统和独立的望远镜。发射通道中设置离焦和相位调制平板偏置,接收通道中设置离焦和相位平板偏置。控制发射离焦量,发射相位调制函数,接收离焦量,接收相位调制函数,用同一个望远镜可以同时实现空间二次项相位附加偏置的激光发射和消除目标点散射回波接收波面像差的离焦光学接收,并产生雷达运动方向上合适的和可控制的相位二次项历程,从而实现孔径合成成像。详细介绍了系统设计,给出了从发射到光电外差接收的全过程传输方程。

枪用白光瞄准镜近期发展方向

1609年,意大利科学家伽利略发明了由一片凸透镜和一片凹透镜组成的望远镜,它能够看到正立的放大的物像,但不易设置分划板。两年之后,德国科学家开普勒发明了由两片凸透镜组成的望远镜,它中间可以设置分划板,但看到的是倒立的放大的物像。后来,人们尝试在林利略望远镜中设置分划板,一直没有取得很令人满意的结果,但在开普勒望远镜中加入透镜或棱镜转像系统获得成功。这样,才有了能看到正立的放大的物像和分划符号的望远镜,因而才会有现在已大量使用的枪用白光望远瞄准镜(以下简称枪瞄镜)。到本世纪三十年代,枪瞄镜的发展已趋成熟.其间苏联军队配装了40式步枪、机枪用枪瞄镜,日本军队则为38式、99式步枪分别配装了2.5倍和4倍枪瞄镜。