Chapter 55-13(a) white plate dust detection(b) white plate dust correction(2) After a Job(a) white plate dust detection(b) white plate dust correctionF-5-292. Particulars of Control(1) White Plate Dust DetectionThe machine compares the shading coefficient obtained from shift shading and the shading coefficient obtained from fixed shading to identify the presence/absence of dust and, if any, coordinates and width of the area.(2) White Plate Dust CorrectionIf the machine detects dust as a result of white plate dust detection, it corrects the shading coefficient of the area using the shading coefficient of both sidesso as to decrease the effects of the presence of dust. It executes shading correction using the coefficient it obtains after correction.If the result of white plate dust detection indicates the presence of dust, the shading coefficient of the area in question will be corrected by the coefficientsof its adjacent areas during shading correction with the aim of reducing the effects of the presence of dust. Thereafter, shading correction will be executedusing the corrected coefficient.F-5-305.3.6 Image Processing5.3.6.1 Overview 0012-9684imagePRESS C1 / Color Image Reader-H1 / imagePRESS C1+ (Printer) / imagePRESS C1+The following shows the major functions of the machine' s image processing system:- CCD (image sensor)number of lines: 3 (RGB, 1 line each)number of pixels: 7350size of pixel: 9.3 x 9.3 ym- Shading Correction shading adjustment: in service modeshading correction: performed for every copyDust detection Dust detectionStart keyON1stSCAN2ndSCANDetection AlgorithmCorrection AlgorithmComputation of shadingcoefficient(shift shading toreference area)Computation of shadingcoefficient(from fixed shading toshading correction position)Detection of coordinates ofstart of dust and widthCorrection of dust areacoefficient using data of both sidesFixing shading positionShading correction positionReference area(Shading coefficientcomputation area)White plateAreaof dustComparison
