In recent years machine vision technology obtained the application in many fields, such as the industry, medical systems and national defence. Researches on the machine vision of the on-line and real-time detecting system. By the aid of optical engineering software ZEMAX, a telecentric optical system is designed, which uses a 1 inch CCD image sensor with 5.5μm pixel size. It can measure the target size and non-contact, with the maximum measurement range of 300mm and the resolution of 0.2mm, magnification is -0.053, the distortion is less than 0.1 percent. The MTF of this system is more than 0.5 in 70lp/mm, and all sorts of the aberrations are corrected well, and the image quality is uniform in all the fields. As the limits of magnification and pixel size of the CCD, the technology of CCD pixel subdivision can be used, and the accuracy can be increased to dozens of times, the accuracy of on-line non-contact measurement System can reach the micron-size. The telecentric degree of the double telecentric lens is very small when the object moves along the optical axis.
Minimally invasive surgery (MIS) has contributed significantly to patient care by reducing the morbidity associated with more invasive procedures. MIS procedures have become standard treatment for gallbladder disease and some abdominal malignancies. The imaging system has played a major role in the evolving field of minimally invasive surgery (MIS). The image need to have good resolution, large magnification, especially, the image need to have depth cue at the same time the image have no flicker and suit brightness. The video stereo-laparoscopy system can meet the demand of the doctors. This paper introduces the 3d video laparoscopy has those characteristic, field frequency: 100Hz, the depth space: 150mm, resolution: 10pl/mm. The work principle of the system is introduced in detail, and the optical system and time-division stereo-display system are described briefly in this paper. The system has focusing image lens, it can image on the CCD chip, the optical signal can change the video signal, and through A/D switch of the image processing system become the digital signal, then display the polarized image on the screen of the monitor through the liquid crystal shutters. The doctors with the polarized glasses can watch the 3D image without flicker of the tissue or organ. The 3D video laparoscope system has apply in the MIS field and praised by doctors. Contrast to the traditional 2D video laparoscopy system, it has some merit such as reducing the time of surgery, reducing the problem of surgery and the trained time.
Stereo endoscope has played an important role in video 3-dimensional laparoscopy system. This paper presents the design principle of the stereo endoscope applying in minimal invasive surgery (MIS). Optical imaging technologies and instrument designs are discussed in relation to their current and future use in MIS procedures, then this paper analyses and compares three design methods of optical system, technical limitations in imaging technology are described along
with potential solutions. We put forward to a new optical design methods, namely, the system adopts two optical channels stereoscopic-imaging technique to replicate human binocular vision. A stereoscopic system for video endoscopes includes objective lens system, relay system, eyepiece system and the focused lens between eyepiece and
CCD. This paper present equal-angle pairs from symmetrically disposed object points to the system. This equal-angle property enables accurate object/image mapping onto the final stereo image pair. And the doctors can watch the true stereo image on the screen. This optical system has common characteristic compare to the common laparoscopy with long work distance-300mm and wide field-70 degree, as a result, the optical system have serious aberration related field, especially in distortion, the distortion can reduced from 15% to 5%.
This paper introduces one on-line measuring system of the metal surface roughness. The system is based on the theory about light's diffusing of the metal surface. Laser is used as the lamp-house of measure and in the system detector collects the light's signals by optical fiber. The surface roughness measuring principle and method are presented and the experiment data are analyzed. After comparing with other approaches, the standard-sample-plate comparison is adopted. The method is simple in structure and high in efficiency and the one-by-one measuring points can reflect the real surface. As for all the factors can induce errors in on-line measuring, the research obtains good result by revising the errors with reparative formula.
This paper demonstrates the use of lifted E2 nozzle with modified developer recipe in TEL MARK 8 track to reduce killer defects such as E2 nozzle imprints and contamination such as resist residues and developer strain. This concept has helped to improve machine uptime due to less occurrence of E2 nozzle related defects shutdown.
By using light as a carrier, the information of voice and data is sent to a receiver through atmosphere, so this system with computer via some interfaces can be applied to link computers into network. This system has shown many advantages on volume weight flexibility, convenience, security and anti- interference. In this paper, firstly, the principle of a laser communication system is introduced, then the performance of LOC, GaAs, AlGaAs semiconductor lasers are presented; moreover, the basis of choosing photo-detector, the characteristic and usage of silicon avalanche photo-detectors, and the threshold detection and false-alarm ratio of the system are presented in detail.
This paper introduces a photoelectric detection system, i.e. the internal surface of the metal tube illuminated by Xenon light through fiber bundle, is imaged on CCD optical receiver by endoscope. The image can be converted to video frequency signal, then this signal can be converted to digital signal by a sampling control system, which processed by a computer. SO the measurement system can clearly display the surface flaws of workspace of complicated construction, and quantitatively measure sorts of flaws by an image processing system.
A study of acousto-optic deflection addressing switch of 1 X N is reported in this paper. The switch device that we have developed consists of a pair of optical waveguide geoidesic lenses, a titled chirped electrode transducer and a Ti:LiNbO3 waveguide on a piece of LiNbO3 substrate in order to achieve the optical deflection addressing function. A single mode fiber and an array of single mode fiber (N) are coupled with the two endfaces of device respectively. The device is a multiplex channel switch. The device working wavelength is 1.55 micrometer. The waveguide geodesic lenses are designed by an optimum analytical method. The non- spherical concave lenses spherical aberrationless in the apertures of beam. That is fabricated in single point diamond turning method. The titled chirped electrode transducer bandwide was designed 200 MHZ. The experiment at 0.633 micrometer He-Ne light source show that the results coincide with the theoretical design. The insertion losses of the device is 8 dB about and the channel's crosstalk is better than -20 dB. Switch has a broad range of applications. Currently, the most promising applications are in the fields of lightwave communications and optical signal processing.
Used He-Ne laser as a light source, CCD camera as the detector of Twyman-Green interferometer, a Twyman-CCD- Microcomputer systems is consisted. With this setup, high accuracy, non-contact, real-time, auto-measuring displacement is realized. As a practical example, the shrinking of 2- components adhesive is measured for a company.
In this paper, with the aid of Fourier transform and reverse Fourier transform not only 2D contour map, but also 3D plot of a tested aspherical surface is obtained by 1- interferogram method, so a simple method is provided for autocontrolling machine-shaping of an aspherical surface. In order to test a variety of aspherical surface, a quasi- universal compensator is designed. The experiment setup for testing aspherical surface is Tywman-CCD-computer system.
The combined use of the photoelectric and electron-optic properties of BSO crystal leads to realize spatia light modulation. Under some condition BSO crystal can become birefringent depending on a local illuminance. The relationship between the distributions of illuminance and birefringence will be discussed. This spatial light modulator can work in real-time, which converts illuminance into transparence. The experiment shows, in order to increase the sensitivity of BSO crystal, an electric field 6 kv/cm at an atmosphere pressure 15 X 105 Pa should be applied to BSO crystal. With BSO crystal we have measured 3D deformation by means of real-time holography.
A new birefringent common-path interterometer with an automatic data-processing system is presented fortesting large convex spherical surfaces. With this interferometer, it is easier to eliminate system errors and to achieve quite accurate measurement. The precision of the system is about λ/50 with an accuracy of about λ/10.
An automatic fringe analysis method for interferograms with an arbitrary closed loop fringe pattern is developed, using an automatic fringe extracting and coding technique in the parallel pseudo-contour tracing form. The principle and procedures have been discussed in detail. It is shown that this method is very easy and convenient in practice.
We have developed a new birefringent common-path interferometric method incorporating an automatic data processing system for testing large convex spherical surfaces. This interferometer can eliminate system errors and achieve accurate results of measurement. Precision is about (lambda) /50 and accuracy is about (lambda) /10.
A new, simple method for on-line rapid testing of the optical transfer function (OTF) of camera lenses has been developed in which the digital fast Fourier transform method is employed using a linear array CCD for sampling the linear spread function (LSF) of the lens under test. The main advantage of the new method is that for the test of off-axis OTF neither the lens under test nor the collimator need to be rotated. Obviously, this method is different from the present complicated test methods. Therefore, this method is simple and easy to accomplish on-line automatic test of OTF. The time required for testing a nine-position OTF such as on-axis +/- 0.7 and +/- 1 viewfields in both meridional and sagittal planes is less than 2-3 min. An OTF testing formula relative to the testing factors has been established. Based on it, the testing accuracy of OTF is discussed with the idea of relative accuracy for the first time. The theoretical results are in agreement with the experiments. Precision is 1-2%. The relative errors of both the modulation transfer function (MTF) and phase transfer function (PTF), which change with spatial frequency f, are about 10% and 3% at f equals 50 c/mm, respectively.