APPARATUS FOR DETECTING SCRATCH OF STEEL PLATE USING MULTI-WAVE LED AND COLOR CCD CAMERA

摘要

PURPOSE: A scratch detector of a steel plate is provided to detect scratch on the surface of a steel plate and to sample depth information by obtaining specific signals corresponding to specific waves of each light with a color CCD(Charge Coupled Device) camera. CONSTITUTION: A scratch detecting system of a steel plate consists of: a red bandwidth LED(Light Emitting Diode,9) for emitting direct light over the surface of a steel plate(1); a blue bandwidth LED(10) for emitting diffused light; an area color CCD camera(11) obtaining a surface image of the steel plate by receiving the light emitted from the LEDs and reflected from the steel plate; and a signal processing computer(3) connected with the camera to analyze the obtained image and to decide scratch on the surface of the steel plate. The color CCD camera obtains the same position of image from the different wave lights at a specular reflection angle and at a diffused reflection angle. The exposure time of the camera is set as 64 microseconds while the exposure time of the red and blue lights is short lower than about 10 microseconds. Thereby, the image of the camera is exposed during a very short time relatively. Therefore, the camera obtains a clear image.