Abstract: An on-line coating adhesion determination apparatus of a galvannealed steel sheet, includes: an X-ray tube which irradiates a galvannealed steel sheet that travels on a transportation line, with X-rays; an optical system which allows the X-rays emitted from the X-ray tube to irradiate the galvannealed steel sheet as a parallel beam and be diffracted; and a detector which measures the intensity of the diffracted X-rays and is installed at a position at which the X-ray diffraction peak corresponding to a crystal lattice spacing d of 1.5 ? or higher is detected, in which an emitted beam luminance of the X-rays is 20 W/mm2 or higher, and the width-direction gain of the X-rays in the optical system is 0.15 or higher. The crystal lattice spacing d may be 1.914 ?. In addition, the energy of the incident X-rays from the X-ray tube may be lower than the excitation energy of Fe-K? fluorescence X-ray.

Abstract: An on-line coating adhesion determination apparatus of a galvannealed steel sheet, includes: an X-ray tube which irradiates a galvannealed steel sheet that travels on a transportation line, with X-rays; an optical system which allows the X-rays emitted from the X-ray tube to irradiate the galvannealed steel sheet as a parallel beam and be diffracted; and a detector which measures the intensity of the diffracted X-rays and is installed at a position at which the X-ray diffraction peak corresponding to a crystal lattice spacing d of 1.5 ? or higher is detected, in which an emitted beam luminance of the X-rays is 20 W/mm2 or higher, and the width-direction gain of the X-rays in the optical system is 0.15 or higher. The crystal lattice spacing d may be 1.914 ?. In addition, the energy of the incident X-rays from the X-ray tube may be lower than the excitation energy of Fe-K? fluorescence X-ray.

Abstract: In response to the trend toward the increase in the number of data layers of optical discs, the invention provides a data erasure method and its optical disc apparatus that enable faster data erasures with a simpler configuration. Test erasures are performed on the test areas T of data layers of an optical disc while the power level Pe of data erasure laser light and the defocus amount ?f of the data erasure laser light from a target data layer are changed. Based on the results of the test erasures, the optimal erasure condition that enables a simultaneous data erasure from the greatest number of data layers is determined. Based on the determined optimal erasure condition, then, the optimal erasure sequence that enables data erasure from all of the data layers with the fewest number of times is determined.

Abstract: This invention provides a technique which ensures that if a recording error occurs in an optical disc, recorded data will be immediately erased from the disc without leaking to third parties. While recording data onto the optical disc, a controller judges whether the recording process has been executed to completion properly. If the recording process is judged to have failed, the controller will stop the recording process and activate an optical pickup to erase recorded data from the data-recording area on the optical disc by overwriting this area with required erasing data.

Abstract: An optical-disc testing apparatus performs test erasures on the test areas T of data layers of an optical disc while changing the power level Pe of data erasure laser light and the defocus amount if of the data erasure laser light from a target data layer. The optical-disc testing apparatus determines an optimal erasure condition that enables a simultaneous data erasure from the greatest number of data layers and an optimal erasure sequence that enables data erasure from all of the data layers with the fewest number of times. The determined optimal erasure condition and sequence are registered on the memory of an optical disc apparatus. The optical disc apparatus reads the registered optimal erasure condition and sequence of the optical disc from its memory and erases data from each of the data layers of the optical disc based on the read optimal erasure condition and sequence.

Abstract: In response to the trend toward the increase in the number of data layers of optical discs, the invention provides a data erasure method and its optical disc apparatus that enable faster data erasures with a simpler configuration. Test erasures are performed on the test areas T of data layers of an optical disc while the power level Pe of data erasure laser light and the defocus amount ?f of the data erasure laser light from a target data layer are changed. Based on the results of the test erasures, the optimal erasure condition that enables a simultaneous data erasure from the greatest number of data layers is determined. Based on the determined optimal erasure condition, then, the optimal erasure sequence that enables data erasure from all of the data layers with the fewest number of times is determined.

Abstract: In an apparatus which encrypts and records, or decrypts and reproduces content necessitated copyright protection using a plurality of encryption keys, the encryption key unique to a drive apparatus is stored into a memory in the apparatus at the time of manufacturing the apparatus. According to the present invention, the presence or absence of encryption key information in a recording apparatus, a reproducing apparatus, or a recording/reproducing apparatus can be easily confirmed When the encryption key unique to the drive apparatus is mounted, a flag indicating the presence of the encryption key is turned on. In other case, when receiving a command to confirm the presence of the encryption key from the outside of the apparatus, the flag which is turned on after confirming the presence of the encryption key by firmware of the apparatus is returned.

Abstract: In the case of a BD or the like, when encryption information used for copyright protection is updated, the version number of defective encryption information is stored into an area of a commercial medium other than the content recording area, and the user is prompted to update to a newer version number. According to an embodiment of the present invention, the version number of encryption information on the device being used can be checked easily by the user by means of an external command. If this is a defect information version number, playback is not performed, and a display that prompts updating of the encryption information is made as required.

Abstract: This invention provides a technique which ensures that if a recording error occurs in an optical disc, recorded data will be immediately erased from the disc without leaking to third parties. While recording data onto the optical disc, a controller judges whether the recording process has been executed to completion properly. If the recording process is judged to have failed, the controller will stop the recording process and activate an optical pickup to erase recorded data from the data-recording area on the optical disc by overwriting this area with required erasing data.

Abstract: In an optical disc apparatus, before the information already existing on an optical disc is erased, the information recorded in a user data area of the optical disc is test-erased with laser light of previously set erasing power first, then after test recording of information in the user date area and evaluation of the test-recorded information in terms of recording quality, erasing power for actually erasing desired information is set in accordance with evaluation results.