Laser-induced Dazzling Phenomena In Vis Ible Light CCD And Their Mechanism

Visible light CCD is widely used in many scopes such as scientific research,production,living and national defense etc. It plays an important role in many aspects such as detection, recognition, identification, taking pictures, tracking, remote sensing, and inspection, etc. However, when irradiated by intense light,for example laser, its performances will temporarily decline or loss. This is named as laser dazzling effect. To discover the phenomena of the laser dazzling effect and study its mechanism can help us to understand the distortion picture of CCD, prevent the CCD from being dazzled by intense light, and disturb the enemy CCD.On the basis of knowing enough about the basic structures, work processes and normal technology of CCD camera, this dissertation gives a series of study mainly on its laser dazzling phenomena and mechanisms. The contents of work are introduced briefly as follows:(1)Based on one dimensional analytical model of body-channel CCD containing charge package, relational expression between depletion layer dimension and quantity of signal charge had been given, by which the voltages in channel and surface were expressed. Using them, the thresholds of signal charge that could be manipulated by CCD had been analyzed.(2)According to the proportional relation between the light density and grey value under the linear state, a method to measure light density exact threshold of CCD video saturation was built, on the basis of which, the methods to measure the intense light response curve of CCD chip and to determine the light density saturation threshold of CCD chip using the curve were built. The reason of slow rise in the saturation scope of the response curve was given.(3)In experiment, we two new phenomena about crosstalk: the gap on crosstalk line and nonsymmetric traditional crosstalk line. We used a new crosstalk mechanism to explain the two phenomena. This new mechanism and traditional crosstalk mechanism were separately named as the first and second crosstalk. Based on the first crosstalk, the unilateral crosstalk line in some special situation was predicted and confirmed in experiment. The even crosstalk line and small moving spots phenomena were reproducted in experiment and were explained using the first crosstalk mechanism. These moving spots were named as subordinate sopts. Their distance formula and the moving direction determinant formula were given. The distance formular was confirmed by experiment results.(4)We discovered the excessive saturation effect of visible light CCD. In experiment, the characteristic video and waveform of excessive saturation effect had been discovered. Its intrinsic mechanism had been given. The equivalent circuit of CCD charge measurement was built. Using it, based on the mechanism, the characteristic waveform had been simulated. And based on the intrinsic mechanism, the method to estimste the order of light intensity threhold of excessive saturation effect of CCD had been given.(5)We discovered three special laser dazzling effects that are induced by the usual technology and operation manner used in CCD system: spots vibration of planar CCD, side spots of linear CCD and fringes of TDI-CCD. We cognized the technologies related to the special dazzling phenomena and gave the detailed reasons of the phenomena. About fringes phenomenon, the formulas of their width, space width and visibility have been given.These formulas have been confirmed by experiment results.Combining a black reference technology, we gave the reason of temporary blank screen caused by crosstalk in planar CCD. The reason of background image loss except spots was given.