Research And Development Of Scientific Grade Ccd Digital Camera

Based on the anaIysis of CCD's (charge coupIed device) imaging principle, thispaper has researched and deveIoped a scientific grade, cooIed CCD digital camera,with lSD029AP a virtuaI phase CCD image sensof, as its core element.This system is made up of the folIowing basic components f the camera head,the camera controller, the host computer interface circuit, the cooling unit and thesoftware. During the design, a seriaI 12 bits AlD converter is selected and digitaIcircuits are pIaced near the analog signal output port of the CCD. ln this way, thesystem can both reaIize far-distance transmission and reduce the readout noise.The reset noise can be virtually eliminated using CDS (correIated doubIe sampling)technique. The communication betWeen the camera and host computer isimplemented using Enhanced ParaIIel Port mode. UtiIizing CCD chip's buiItinplatinum thermistor and Peltier cooIeF, a closed-loop feedback temperature controlcircuit is designed to keep the temperature of CCD chip about -35t, reducing thedark current noise and improving image quality. lntegration time and readout speedcan be changed by the software in accordance with experimentaI conditions.ExperimentaI resuIts indicat8 that the scientific grade CCD camera obtainsexpected functions and is capable of presenting a clear picture of an object. It hasthe virtues of outstanding sensitivity, low noise, fine resoIution, exceIlent dynamicrange, controlIable int6gration time and readout speed, as welI as reaI tirne dataacquisition, etc.