Study Of Resulution And Motion Artifacts On Displays

With the development of the high definition television, the high resolution and definition are needed. The main factors to determine the resolution are the spot size in CRT and motion artifacts in LCDs. The evaluation and measurement methods of the spot size and motion artifacts are studied deeply. A novel technique has been successfully developed to measure the spot size in a TV/monitor tube precisely by means of a cathode pulsed amplifier, pulsed deflection and micro stepping deflection methods. The relationship between image definition and spot size, luminance response were studied in experiments. Then by analyzing the originations of LCD motion artifacts, based on the measurement of step luminance response of LCD and the smooth-pursuit eye-tracking and temporal integration a new simulation method is proposed to measure and characterize motion artifacts in LCDs. The precise LCD luminance transition measurement system was established. The simulation results were validated by the perception experiments.During the development period of beam display devices, the spot size is not only characterized by computer modeling and calculations, but also by measurements in order to check the various models and concepts for display devices. Especially during electron gun and deflect unit designing period there is no chassis to drive the tube, so some special equipment should be designed for the static spot size measurement. The spot size in this technique is created by an electric pulse, which synchronizes with the frequency of the main power so that the influence of the magnetic stray field can be reduced considerably. The technical advantages over conventional spot size measurements. The achievements of the research work as the precise spot size measurement system is presented as follows: The static spot of a pulsed beam (100μA～6 mA) at any position on the screen can be measured by means of cathode- or grid pulse amplifier (width 100ns, 0～200 V ) and a horizontal (2ms,10 A) and vertical (6ms, 2 A) pulse deflection amplifier, all having a frame frequency 20ms. The disturbing influence of shadow mask has been removed by a micro stepping method. Special narrow pulse amplifiers and software for control and analysis have been developed for this system.Experiments with this new system show repeatability in spot size of about 5% in results over the whole screen area. Also good agreement has been found with computer simulation of the guns under investigation. The Improved Spot Size Measurement System can easily deal with different kinds of the CPTs and CMTs. The system is especially designed for and met the requirement of electron-optic gun or DU designers to make accurate measurement during the development period.A new method is proposed to measure and characterize motion artifacts in LCDs. The method is based on accurate measurements of LCD temporal step response curves with a photo-diode, and modeling the moving image as perceived by smooth-pursuit eye-tracking and temporal integration. The Precise measurement system, simulation method and a perception protocol have been established to evaluate LCD motion artifacts. The temporal luminance transition curves can be precisely acquired by using a fast, eye-sensitivity compensated, photo-diode.The temporal response waveforms, which reflect the characteristics of a frame-sequential display in detail, are used as input for the simulation model. The model assumes smooth-pursuit eye-tracking and temporal integration of the luminance data. The spatial artifacts can be simulated by Time-Space conversion based on temporal characteristics and human vision system. The model was validated with a perception experiment which demonstrates the stimulus on the same panel. This simulation method can predict the effects of the new methods without the real products. This simulation method is useful to evaluate the motion artifacts and validate the new ideas in the design period.