| The nowadays LCD display screen has many advantages such as low radiation, healthy environmental protection and low energy consumption,it is true, but the number of LCD users out of the purpose of their professional use is limited to its low response,small angle of view scope and low-brighted color.However ,the above-mentioned limitation in technological bottleneck of flat panel display will be able to be renewed by the next generation of OLED display technology .Having the strengths of low energy consumption, high brightness ,fast response and without the angle of view limit, there is no doubt OLED will become the new star of next generation's flat display equipment,and thus shows to us a new page on the development of displaying.This article gives a intensive discussion and research to the AM-OLED display technique ,mainly on the points as follows: the design of pixel driving circuits and parameters determined ,the improvements towards more ways of pixel circuit , designing and applying the driving circuits of gate and drain integrated on the substrate of the display,designing the input protection circuit and the input buffer and determining the parameters, and carrying on the simulation confirmation to the designed circuits with the Hspice simulation software.The primary coverage of this article is as follows:In the first chapter, several kinds of common panel display technologies were outlined and compared, and the superiority of the OLED technology was emphasized. The article also pointed out that the development of OLED had vital significance for our country to develop the display technology independently and the problems existed in the OLED display technology.The OLED component structure and the principle of work were introduced in details in the second chapter,and the author researched the model of OLED manufactured from the laboratory,which laid the foundation for the latter research to the driving circuits of OLED.Also in this section, many kinds of driving ways of OLED were enumerated and compared,and then the article analyzed emphatically the differences between AM-OLED and PM-OLED, which not only highlighted the superiority of AM-OLED technology, but also provided the evidence for the study of this article. Finally in the article, the performance of Level62 RPI model of TFT was analyzed, of which the output character in different conditions and kink effect character were analyzed emphatically.The third chapter of the article mainly illustrated the structure and the working principle of two forms of pixel circuits(voltage-driving pixel circuit and current-driving pixel circuit), and the precise computation and reasonable selecting circuit parameters guaranteed that the pixel driving circuits had excellent operating performance.In the fourth chapter of the article, some deficiencies of the two-TFT voltage-driving pixel circuit was improved after analyzing, meanwhile, in order to increase the aperture ratio, extend the component's lifetime and coordinate block technology of the drain-driving circuit, the author used three improvement methods to optimize the four-TFT current-driving pixel circuit.In the Fifth chapter, reasonably using some fundamental unit circuits, the author designed bidirectional shifter, controlling circuit for patterns-selecting, partitially clear controling circuit and buffer and so on, which not only constituted the gate and source driving circuits that suited OLED display for VGA and could be used to select patterns, but also carried on the whole to the gate-driving circuit and the drain-driving circuit the simulation conformation.Chapter six analyzed the breakdown character of TFT and calculated the permanent breakdown voltage of TFT's gate.According to the analysis of the diode protection circuit, using the input protection circuit of TFT in order to shunt and clamp for the gate of TFT. After analyzing the character of Schmitt trigger, it could be used as the input buffer and play the denosing role during the data transmission, and finally it was confirmed its feasibility through the simulation, and enhanced working stability of the display.The summary of the whole dissertation was arranged in Chapter Seven, the later work and the research direction need to be done were pointed out in this section. The author collected and cleaned up a lot of information and the literatures related to the AM-OLED driving technology, and carried on the introduction to TFT's character in details, which prepared the rationale for the following research work.The main contribution of this dissertation lies in:1.Each parameter of the Four-TFT current-driving pixel circuit components was precisely chosen and all of them were confirmed their rationality through the simulation, which laid the rationale for the reasonable improvement of the pixel driving circuit.2.Improving the two-TFT voltage-driving pixel circuit in order to lengthen the lifetime of OLED to a certain extent. Meanwhile, in order to increase the aperture ratio, extend component's lifetime and coordinate the drain-driving circuit block technology, the improvement was carried on the four-TFT current-driving pixel circuit in terms of area, AC-driving and block.3.This article explored on the large-scale integrated OLED display technology, and also designed each part of integrated gate-driving circuit and source-driving circuit that suited OLED display for VGA and could be used to select patterns,and confirmed its rationality through the simulation, which will lay the foundation for research and development of the future integrated technology.4.This article designed the structures of input protection circuit and input buffer of the display, which confirmed its feasibility through the simulation. |
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