INSPECTING DEVICE FOR DISK SURFACE

• Main Authors: KIUCHI TETSUO, YOSHIDA KAZUYUKI
• Format: Patent
• Language: English
• Published: 08.06.1999
• Edition: 6
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PROBLEM TO BE SOLVED: To enable discriminating damage realistically by storing a second reference area value being smaller than the reference area value, storing a second reference light quantity value being larger than the reference light quantity value, comparing an area of a region formed by a defective point with the second reference area value, and comparing the maximum light quantity value in the defective point with the second reference light quantity value when the area value is larger than the second reference area value. SOLUTION: When a region area is not larger than a first reference area value, the region area is compared with a second reference area value previously stored in a reference value storing section 15 for discriminating defect, when the region area value is larger than the second reference area value, a light quantity value of a candidate point constituting an assembly part is retrieved, and a peak value is extracted. Next, the peak value is compared with threshold value being a second reference light quantity value previously stored in the reference value storing section 15 for discriminating defect, when the peak value is larger than the threshold value, discrimination that damage exists is outputted. Further, a threshold value previously stored is larger than a light quantity reference value used in defect candidate detection processing.