Abstract: An optical disc apparatus includes an optical pickup for outputting an output signal according to reflected light from an optical disc medium and a comparison signal output unit for outputting a comparison signal indicating whether a level of the output signal is higher than a threshold value, relatively moves an objective lens with respect to a surface of the medium within a predetermined range to measure a maximum level of the output signal, sets a value determined according to the maximum level as a threshold value used by the comparison signal output unit, and measures a level of a reflected signal corresponding to reflected light from each of a plurality of signal surfaces based on the output signal in a time period in which the comparison signal indicates that the level of the output signal is higher than the set threshold value, while moving the objective lens.

Abstract: An optical disc apparatus includes an optical pickup for outputting an output signal according to reflected light from an optical disc medium and a comparison signal output unit for outputting a comparison signal indicating whether a level of the output signal is higher than a threshold value, relatively moves an objective lens with respect to a surface of the medium within a predetermined range to measure a maximum level of the output signal, sets a value determined according to the maximum level as a threshold value used by the comparison signal output unit, and measures a level of a reflected signal corresponding to reflected light from each of a plurality of signal surfaces based on the output signal in a time period in which the comparison signal indicates that the level of the output signal is higher than the set threshold value, while moving the objective lens.

Abstract: This invention is to provide a method of efficiently removing scales adhered to a pipe and the like. A descaled object with scales deposited thereto is covered with a solvent at least on its scaled surface. A magnetic field is generated by supply a frequency signal to a coil, and the descaled object and the solvent are disposed within this magnetic field. Signals having frequencies that are set beforehand at every scale are supplied to the coils as the frequency signals. The frequencies of the frequency signals supplied to the coils and which are set beforehand are frequencies required when an electric current flows through the solvent which covers the scales.

Abstract: This invention is to provide a method of efficiently removing scales adhered to a pipe and the like. A descaled object with scales deposited thereto is covered with a solvent at least on its scaled surface. A magnetic field is generated by supply a frequency signal to a coil, and the descaled object and the solvent are disposed within this magnetic field. Signals having frequencies that are set beforehand at every scale are supplied to the coils as the frequency signals. The frequencies of the frequency signals supplied to the coils and which are set beforehand are frequencies required when an electric current flows through the solvent which covers the scales.

Abstract: A method and apparatus for detecting a defect of an object to be measured that has a first section having a first plate part and a second plate part which has a plate surface opposite to a plate surface of the first plate part and is integral with the first plate part or is connected to the first plate part and a second section that is united integrally with the first section or is bonded to the first section. The object to be measured has an intersection part formed between the plate surface of the first and/or second plate part of the first section and the surface of the united part of the second section with the first section, any defect formed in the intersection part being detected. Further, if the first section is a major working section, the life of the object to be detected is detected by detecting deterioration of the first section.

Abstract: A method and apparatus for detecting a change in the state of a part of an object to be measured that has a section having a first plate part and a second plate part which has a plate surface opposite to a plate surface of the first plate part with a gap between the plate surfaces and is integral with the first plate part or is connected to the first plate part.

Abstract: A method and apparatus for detecting a defect of an object to be measured that has a first section having a first plate part and a second plate part which has a plate surface opposite to a plate surface of the first plate part and is integral with the first plate part or is connected to the first plate part and a second section that is united integrally with the first section or is bonded to the first section. The object to be measured has an intersection part formed between the plate surface of the first and/or second plate part of the first section and the surface of the united part of the second section with the first section, any defect formed in the intersection part being detected. Further, if the first section is a major working section, the life of the object to be detected is detected by detecting deterioration of the first section.

Abstract: A nondestructive inspection method predicts the lifetime of a measured object. A measured object is made to vibrate, and there is obtained a frequency difference .increment.f between a frequency of a nth-order spectrum and a frequency of a (n+1)th-order spectrum of any one of longitudinal waves, transverse waves and distortional waves generated in the measured object when the measured object is made to vibrate. It is possible to predict lifetime of the measured object by detecting degree of deterioration of the measured object based on a relational curve representing the frequency difference .increment.f and the circumstances of use of the measured object.

Abstract: A test object having a plurality of protrusions is inspected for a defect and/or different-hardness by applying vibration to the test object. Spectral data of the vibration of the test object is analyzed based on signals indicative of the vibration of the protrusions. Spectral energy peaks are then detected in different spectral frequency regions corresponding respectively to the protrusions based on the signals. It is then determined whether there are two separate spectral energy peaks in the spectral region corresponding to each of the protrusions, thereby to determining whether there is a defect and/or different-hardness portion in each of the protrusions.

Abstract: A test object such as an engine cylinder is inspected for any defect such as a crack, a blowhole, a cavity, or the like by applying vibration to the test object at two different positions on a side thereof. While the test object is vibrating, signals indicative of the vibration of the test object are detected. From the detected signals, there are produced a signal indicative of a natural vibration of the test object and a signal indicative of a defect-induced vibration of the test object. The signal indicative of a natural vibration and the signal indicative of a defect-induced vibration are compared to determine whether there is a defect in the test object.

Abstract: A defect detecting method for detecting whether or not an object to be measured has a defect includes the steps of vibrating the object to be measured, picking up the vibration, and detecting that a spectrum of the characteristic vibration of the object to be measured is separated into two portions. Also, a defect detecting apparatus includes a vibrator for vibrating an object to be measured, a vibration detector for picking up a vibration of the object to be measured and for converting the vibration into an electric signal, and computation process and determination equipment for receiving the electric signal from the detector, for analyzing a spectrum of a characteristic vibration of the object to be measured, and for determining whether a defect is present or absent depending on whether a spectrum of a defect of the object to be measured is present or absent.

Abstract: A defect detecting method for detecting whether or not an object to be measured has a defect comprises the steps of vibrating the object to be measured, picking up the vibration, and detecting that a spectrum of the characteristic vibration of the object to be measured is separated into two portions. Also, a defect detecting apparatus comprises a vibrator vibrating an object to be measured, a detector for picking up an vibration of the object to be measured and for converting the vibration into an electric signal, and a signal processor for receiving the electric signal from the detector, for analyzing a spectrum of a characteristic vibration of the object to be measured, and for determining whether the defect is present or absent depending on whether a spectrum of a defect of the object to be measured is present or absent.

Abstract: An optical disc memory for optically storing and retrieving information formed of a substrate and a recording layer supported on the substrate. The recording layer has a chemically stable dielectric material and a semiconductor which has an optical property that changes reversibly as a function of the intensity of a laser beam applied through the substrate. A multilayered optical disc memory having a substrate, a recording layer formed on the substrate and a metallic layer formed on the recording layer, and a method of optically storing and retrieving information by using the above-described optical disc memory, are also disclosed.

Abstract: In a thermal transfer printer of the invention, the urging force acting between a thermal head, an ink film and recording paper is released at a point where the thermal head is not operating, that is, before or after one page or at a point of line space or the like. The ink film is fed without printing, so that new portion of the film may be opposed to the head or loosened film may be kept taut. Wrinkles of the ink film are eliminated, and excellent recording is performed without local transfer failure.