Flying Spot Scanner Research Articles

High efficiency symmetrical scanning optics

A compact, simple, polygon-type flying spot scanner with high light throughput, well controlled spot size and good linearity is described. This underfilled, double pass optical system with axial input provides a large scan angle with few optical elements and thus lends itself to a cost-effective design. It has been successfully implemented for several applications, including colour printing.

Digital techniques in film scanning

Over the last few years there have been dramatic changes in the design of telecine. These have been made possible by advances in semiconductor technology. The paper discusses the problems of transferring film to television, and describes the earlier type of flying spot telecine. The potential impairments, particularly in terms of shading and focus interlace flicker effects are discussed. The first of the modern telecines was a jump scan system, and this is described with some discussion of the problems of operating this system on 60Hz TV field rate systems. The sequential scanning system, made possible by the use of digital storage is then considered, and a description is given of this system when applied to a flying spot scanner. The advent of suitable linear array sensors has made it possible to design a completely new type of telecine. This type of telecine is described. Analogue signal processing for telecine is difficult because of the high contrast range and high degree of nonlinear correction required. A totally digital approach to signal processing for telecine is now possible, and a description of such a system is given. Mention is made of the use of microprocessors and digital techniques in the design of the film transport mechanism, and there is a brief outline of some possible future developments.

Flying-Spot Scanner on 525-Line NTSC Standards

In Europe, the flying-spot scanner has been the predominant form of telecine device since the beginnings of public broadcasting; in North America, however, it has not gained widespread popularity. The basic reasons for this situation are given. Advances in flying-spot systems are described, with emphasis on the development of a scanner for the 525-line NTSC system.

Comments on the Computerization of an Analytical Electron Microscope

The digital computer has had a dramatic impact on most specialties of science, and electron microscopy is no exception. Until quite recently the majority of applications in electron microscopy involve the digitization of a transmission micrograph recorded on a photographic emulsion. Such digitization is carried out by a device such as a rotating drum or flat bed microdensitometer or a flying spot scanner. Subsequent processing of the digitized image is carried out in a large central computer. It was obvious from the beginning that the output from a scanning mode microscope could be directly digitized. There have recently been several reports of such work now that computers with sufficient memory, mass storage, and speed have become available at an acceptable cost (see, for example, references 2, 3, 5). Our own laboratory has nearly completed the hardware interface of a Digital Equipment Corporation PDP 11-60 mini-computer to a 200 keV analytical electron microscope (Hitachi H700H). In this paper we will discuss several factors regarding the overall design of such a system.

A grey level frequency histogram representation of animal cell colonies seen by scattered light

A complete system of hardware and software is described, which permits determination of the three-dimensional shape of animal cell colonies. The cells are photographed by light scattered through an angle of approximately 45° during passage through the cells. The images of the films are analyzed using a computer controlled flying spot scanner. The colony perimeter points are stored as linked lists until the perimeter is finished, at which time summary data such as perimeter length and colony area are computed. The grey level information in each colony image, corresponding to the thickness distribution, is stored as a grey level frequency histogram. A circularly normalized colony thickness profile that increases monotonically from edge to center can be constructed from this histogram.

Simple flying spot scanner for electron beam lithography on a scanning electron microscope without beam blanking capability

A novel low-cost flying spot scanner that allows a standard scanning electron microscope to be converted into an electron beam lithography system is described. Such a system is useful as a research tool for fabricating small arrays of submicron structures and devices.

Scophony light valve

The optical modulator in a flying spot scanner converts the electronic video signal into a corresponding temporal modulation of a light beam. An alternative configuration, which directly exploits the spatial modulation of an acoustooptic cell, is the Scophony scanner, first developed by the Scophony Laboratories of London during the 1930s. The Scophony scanner responds like a coherent imaging system, whereas the flying spot scanner performs like an incoherent imaging system, when the light source is spatially coherent. The Scophony response is intimately linked to the concepts of FM blur and the deflector as video spectrum bandpass filter.

High-speed digital image processor with special-purpose hardware for two-dimensional convolution

A high-speed digital image processor combined with a flying spot scanner and special purpose hardware for two-dimensional convolution has been developed. This processor is applicable to image enhancement, image restoration, and feature extraction. The parallel and/or serial architectures of the processor enable digital image processing for a high-resolution image at a fast process rate. Realization of the high-speed operation of two-dimensional convolution is greatly due to the special scanning method of a flying spot scanner. This processor is well suited to process the image recorded on the photographic film by means of the two-dimensional digital filtering technique. Some experimental results are given to verify the capability of the developed processor.

Image processing techniques for the evaluation of microvascular hemodynamics in ophthalmoscopic photography

Examination of fundus provides useful diagnostic information in patients with abnormal vascular walls. Therefore, on-line image processing of fundus is required for the more quantitative and time saving evaluation of vascular abnormalities and hemodynamics in microvascular bed in fundus.In this study electronic data processing techniques were introduced in order to develope a practical image processing system in ophthalmoscopic photography. Two experiments of different approaches were attempted, that is, firstly, computer image processing of a static photograph and, secondly the development of television picture scanning device to measure blood flow velocities.1. A 35mm picture film of fluorescence fundus photography was processed by means of a flying spot scanner into a digital picture with 256×256 pixels on a punched tape. This tape was then subjected to a computer image processing with a program to obtain outputs of contour maps and histograms of optical densities. Results showed that capillaries of diameter of as less as 20 micra could be distinguished. It seems that this kind of image processing technique can be used to evaluate quantitatively the leakage of fluorescent tracer through vascular walls.2. An elecronic data processing unit was deviced to measure blood flow velocities in microvessels. This was designed to sample out instantaneous optical density changes at two different points chosen arbitrarily on the screen of monitor television which was connected directly to the microscope through a television camera. Peaks of the curve of optical density changes showing the passage of a tracer such as fluorescent substance or plasma pocket were recorded on a penrecorder or a CRT. The blood velocity was thus calculated by the measurements of time delay between two peaks and the distance between two sampling points.Performance of the unit above stated was tested in the animal experiments of intra-vital microscopic observation of capillary blood flow in the rat mesentery. It was found that the capillary blood flow velocities up to 50mm/sec could be measured with enough accuracy.Both these techniques seemed to provide a basis of on-line image processing of ophthalmoscopic photography with a high sensitive television camera connected directly to the microscope.

Display systems in nuclear medicine

Image display has traditionally been implicated as the limiting factor in the usefulness of digital data processing in nuclear medicine. This was partly due to limited technology and partly to an attempt to use a single system for all displays. Because of the widely varying characteristics of the various nuclear medicine procedures, no single system can perform optimally in all studies. The various uses for the display in data processing are: user interaction, feature extraction, quantitative parameter estimation, correlation with previous studies and reporting. User interaction poses the least stringent requirements on the display. Typewriters, line printers, and standard computer terminals are adequate for this mode of operation. Display of monitor images to allow the operator to follow the processing of the data requires only a moderate quality display, and, for this, a storage scope display or gray scale with a limited number of gray scales is useful. Interactive displays, which are used to guide the processing, must have some means of allowing the user to indicate regions of interest. Joysticks, cursors, or graphic tablets can perform this function. For display of images to be used for diagnostic interpretation, a high-quality image must be produced, which allows the entire dynamic range of data to be shown to the clinician. Printing of multiple images on an electrostatic plotter or on film used in a flying-spot scanner mode can provide the clinician with such images. Display of dynamic data places another restriction on the system in that not only must spatial distribution be represented, but the temporal distribution of activity must also be shown. This is approached in one of three ways. If the problem is one of changing organ size, as in a cardiac ventricular ejection fraction measurement, then the overlaying of the organ edges as a function of time, along with a curve of the change in the area (or counts) as a function of time, is adequate. If, however, the problem is one of measuring a single organ function as a function of time as in a cardiac bolus study where the presence of a shunt is suspected, then one can use time-coded color displays in which the activity distribution in selected time segments is displayed in different colors. In this case, the overlapping activity areas are shown as the summation of the individual colors, while the nonoverlapping areas remain in their respective colors.

Scanning moiré method and automatic measurement of 3-D shapes

A new type of moiré and its application to topography are discussed. moiré fringes are generated by observing a grating projected on an object under test with a scanning imaging device. The general equations of the projection-type moiré topography are given. By controlling the phase, the pitch, or the direction of the virtual grating corresponding to the scanning lines of the imaging device, the automatic sign determination of the contour lines is accomplished. By the use of a high precision flying spot scanner with CRT(DD-tube) and a minicomputer system, an experimental measurement system is developed. Very significant is the fact that a contour line system and a sectional shape of the object are automatically reconstructed and displayed on a color TV monitor.

Application of Special Film Transport Functions in an Electronic Video Recording System

Electronic Video Recording (EVR) is a system for recording encoded color television signals on black and white motion-picture film; in playback, the player scans the film with a flying spot scanner to generate video signals to be applied to a receiver's antenna connections. In the Japanese exemplification of the EVR system, there have been new developments, including special transport control formats on the film and new player functions such as auto-repeat, alternating operation, chapter access and frame retrieval. These new developments, which did not involve changing the original EVR format and functions, have helped to broaden the potential market for EVR machines. An EVR game machine called “EVR Race” has become very popular at Japanese amusement centers; with it, bettors wager tokens or medals on the outcome of horseraces that are generated within the machine and displayed on a television screen. Such machines are extraordinarily reliable and stable in performance, and the film lasts for 1600 hours of operation. Alternating dual half-height color cassettes have been developed and found application in an “EVR Baseball” game.

Light spot scanner on a gallium arsenide strip

A one dimensional monolithic array of GaAs light emitting PNPN diodes processed on a single crystal strip, intended for use as a flying spot scanner, is proposed. This will be called the Light Spot Scanner (LSS). A bright spot (ON state of the light emitting PNPN diode) shifts from one elementary diode to the next with the aid of a three-phase driving voltage. The experimental GaAs LSS consisted of 100 diode elements. The driving current was within 50–300 mA at voltages ranging from 1.2 to 1.5 volts. The effective light output of 9400 Å wavelength was about 1.5 mW when driven at 50 mA. The maximum scanning speed was 3.0 × 10 5 elements/sec.

Three-dimensional echocardiograms and two-dimensional echocardiographic images at desired planes by a computerized system.

Abstract We applied our newly developed computerized image processing system for three-dimensional (3-D) echocardiographic display with binocular parallax shift and for constructing two-dimensional (2-D) echocardiographic images in desired planes from sequential recordings of 2-D echocardiograms recorded with antero-posterior emission of ultrasound beams. This system mainly consisted of a flying spot scanner, a minicomputer and a display cathode ray tube. This study was done in a healthy subject and a case with atrial septal defect. In the stereogram of the healthy subject the left ventricle, atrium and the aorta were visualized in depth with a stereoviewer. In the stereogram of atrial septal defect, the defect and the remaining atrial septum were clearly observed also in depth. We could accomplish the reconstruction of 2-D echocardiograms of these materials in desired planes. The frontal plane 2-D echocardiograms provided useful data.

Environmental Factors Influencing Semidesert Grassland Perennial Grass Demography

Long-term chart quadrat records from the Jornada Experimental Range in south-central New Mexico were photographed, the negatives analyzed with a flying-spot scanner, and the information converted for computer analyses. Some 35 quadrats with data from about 30 to 50 years duration were used giving records on the life-span of 12,437 perennial grass plants of seven species. Maximum life spans varied from 28 years for Bouteloua eripoda to only 7 years for Hilaria mutica. Mean life span for plants living at least 1 year varied from 3.8 to 3.0 years for these species. Average age-specific survival rates for seven perennial grasses increased from 0.39 at age 1 up to a maximum of 0.68 at age 7 and down to 0.48 at age 12. The level of grazing over the past years had little effect on plant survival, but cattle movement and trampling caused the death of some newly es- tablished grasses. A water-budget model produced results that could be readily interpreted in understanding plant survival. The relationship between the number of days of effective moisture in a given time period and the age-specific survival rates for each age class was pronounced. The period between the second and fourth age classes was most critical as regards availability of water. For newly established plants with shallow root systems, the precipitation of the immediate growing season was more important than precipitation for longer antecedent intervals. Continuous, reliable data, spanning long time periods are extremely rare for plant communities, particularly for herbaceous plants. Data on individual plants, necessary for examining many aspects of life history, are even more scarce. One of the major sources of such in- formation for herbaceous communities has been through chart quad- rat records in which permanently established quadrats are charted accurately over a period of years. Only limited amounts of such in- formation are reported in the literature. For humid and subhumid grasslands Harper (1960, 1967) has reported on demographic charac- teristics of Lemma minor and Salvina natans and Kerster (1968) reported on Liatris aspera. For semiarid and arid areas Nelson (1934)

Fast-Neutron Hodoscope at TREAT: Data Processing, Analysis, and Results

The fast-neutron hodoscope at the Transient Reactor Test Facility is designed for the determination of fuel motion during the course of brief (0.1- to 30-sec) power transients. During the course of a transient test, data must be recorded from each of 334 hodoscope channels at count rates up to 2 million/sec each, down to millisecond time intervals. This is accomplished in a relatively reliable and inexpensive manner by displaying counts from each detector sequentially in binary code on a lamp panel, which is photographed by a high-speed framing camera, producing a film record of the transient test. After chemical development, the film is examined by a computer-controlled flying-spot scanner, and the position and density of candidate lamp images are recorded on magnetic tape. Through further computer processing, these images are sorted and decoded, and the count rate is recovered for each detector at each instant of collection time. A cathode-ray tube and a plotter, both computer controlled, are used to recreate and analyze the fuel motion history of the experiment. Analysis is directed toward fuel distortion or expansion prior to clad failure, slumping, dispersion, amount and rates of movement, post-scram relocation, and ultimate disposition of fuel.

Hardware processor for data reduction task in the field of experimental high energy nuclear physics

A special purpose hardware processor has been built for data reduction in real time with a mechanical flying spot scanner in the analysis of bubble and spark chamber films. The processor implements in about 4 s an algorithm whose simulation in Fortran on an IBM 360 44 computer takes about 5 min. High speed of operation is obtained with a Random Logic TTL Design.

Computers and the kinesiology of gait

Three methods of acquiring kinesiological information are presented, each utilizing various types of peripheral computational equipment. A simple economic stroboscopic flash photographic method, movie photography and the use of a flying spot scanner, and finally, a videotaping technique are discussed. The methods are contrasted and various results acquired are presented. Numerous display possibilities are alluded to and the use of angle-angle diagrams is emphasized for total hip-replacement patients.

Video Encoding Using an Adaptive Digital Delta Modulator with Overshoot Suppression

An overshoot suppression scheme to improve the performance of the digital Song adaptive delta modulator (DM) for picture transmission is described. This scheme allows for a faster increase in the step sizes than permitted by overshoot and settling time considerations, thus improving rise-time performance. The overshoot suppression (OSS) algorithm used has been verified using computer simulation on a PDP-8. Furthermore, experimental results using computer generated test pictures as well as pictures from a flying-spot scanner show the improvements due to the overshoot suppression scheme. It is also shown that the additional hardware required for the actual implementation of the algorithm is simpler than those encountered in the literature, and gives better signal-tracking accuracy. Upper bounds for the settling time, with and without OSS, are derived showing an improvement with the suppression scheme. Stability conditions are also derived permitting the proper selection of DM parameters.

A feasible computer system for grey-level, pictorial pattern recognition

A general-purpose interactive hardware-software system is described which allows the analysis, representation and enhancement of poor quality, multiple-frame, grey-level pictures. A precise, computer-controlled, high-speed, random-access flying-spot scanner is used. Contour-finding, piece-wise linear fitting and global region-extraction algorithms with an interactive executive program are described. The results obtained when the system was applied to straight line drawings and cine-angiograms are given.