Apparatus for observing features and defects of a sample

An optical inspection apparatus for generating a picture image of an optical disk, wherein a first defect type is distinguishable from a second defect type in the image, the apparatus comprising:

• a first light source, having a first intensity, for irradiating a first side of a recording layer of the optical disk and reflecting light therefrom whereby features and defects of the first side are detachable;
• a second light source, having a second intensity different from the first intensity, for irradiating a second side of the recording layer and transmitting light through defects extending through the recording layer;
• a black and white video camera facing the first side for receiving the reflected light and the transmitted light in the same field of vision;
• image processing means, responsive to said black and white video camera, for generating a composite picture image signal;
• and
• a color monitor coupled for receiving the composite picture image signal from said image processing means and displaying the defects of the first side in a first color, the defects extending through the recording layer in a second color and the features of the first side in at least a third color.