摘要:
The present invention is to provide an optical surface defect inspection apparatus or an optical surface defect inspection method that can improve a signal-to-noise ratio according to a multi-segmented cell method without performing autofocus operations, and can implement highly sensitive inspection. The present invention is an optical surface defect inspection apparatus or an optical surface defect inspection method in which an inspection beam is applied onto a test subject, an image of a scattered light from the surface of the test subject is formed on a photo-detector, and a defect on the surface of the test subject is inspected based on an output from the photo-detector. The photo-detector has an optical fiber bundle. One end thereof forms a circular light receiving surface to receive the scattered light. The other end thereof is connected to a plurality of light receiving devices. The optical fiber bundle is divided into a plurality of fan-shaped cells in the light receiving surface, and connected to the light emitting devices in units of the cells for performing the inspection based on the outputs of the plurality of cells.
摘要:
A method for moving magnetic heads in a magnetic recording/reproducing apparatus, which comprises the steps of writing high-frequency signals in the magnetic recording/reproducing tracks; and then, either (i) conducting DC erasing or AC erasing to inspect extra pulse signals reproduced from the erased tracks, or (ii) inspecting concurrently occurring signals of missing pulse and spike pulse, which are reproduced from the written signals, whereby minute protrusions on a surface of the tracks were detected. Reading and writing of information are conducted while the magnetic heads are moved in a manner controlled so that reading and writing of information in specific tracks having defects is avoided. This method enhances reliability and life of the magnetic recording/reproducing apparatus.
摘要:
A method for moving magnetic heads in a magnetic recording/reproducing apparatus, which comprises the steps of writing high-frequency signals in the magnetic recording/reproducing tracks; and then, either (i) conducting DC erasing or AC erasing to inspect extra pulse signals reproduced from the erased tracks, or (ii) inspecting concurrently occurring signals of missing pulse and spike pulse, which are reproduced from the written signals, whereby minute protrusions on a surface of the tracks were detected. Reading and writing of information are conducted while the magnetic heads are moved in a manner controlled so that reading and writing of information in specific tracks having defects is avoided. This method enhances reliability and life of the magnetic recording/reproducing apparatus.