Abstract: An object of the present invention is to provide a method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least the following step: a workpiece is subjected to an oxidation treatment or mixed with an oxidation-treated R—Fe—B based magnet alloy, and then subjected to a heat treatment in the presence of carbon at a temperature of 1000° C. or more, thereby separating a heavy rare earth element in the form of an oxide from an iron group element.

Abstract: An object of the present invention is to provide a method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least a step of separating a rare earth element in the form of an oxide from an iron group element by subjecting a workpiece to an oxidation treatment, then turning the treatment environment into an environment where carbon black is present, and subjecting the oxidation-treated workpiece to a heat treatment at a temperature of 1000° C. or more in an inert gas atmosphere or in vacuum.

Abstract: An object of the present invention is to provide a method for producing an alloy recycled material by effectively removing carbon from a carbon-containing alloy, which is produced as scrap or sludge of an R—Fe—B based permanent magnet, a used magnet, or the like. The method of the present invention as a means for resolution is characterized in that a carbon-containing R—Fe—B based permanent magnet alloy is subjected to an HDDR treatment to remove carbon. An alloy recycled material produced by the method of the present invention contains a reduced amount of carbon. Therefore, in the case where it is recycled for the production of a magnet, even when an increased amount is subjected to high-frequency heating in a vacuum melting furnace, a non-negligible increase in the amount of carbon contained in the produced magnet can be avoided.

Abstract: An objective of the invention is to provide a method and system for separating a particular rare earth element from a rare earth magnet at a high separation ratio and by a simple process. There is provided a rare earth separation method for separating a first and a second groups of rare earth elements contained in a magnet, the method including: a starting powder preparation step from the magnet; a magnet component oxidation heat treatment step; a rare earth oxide separation step from the magnet components oxide powder; a powder size optimization step; a chlorinating agent mixing step; a chlorination/oxychlorination heat treatment step of forming a “first group rare earth chlorides”/“second group rare earth oxychlorides” mixture; a selective dissolution step of selectively dissolving the first group rare earth chlorides in the solvent and leaving the second group rare earth oxychlorides undissolved in solid phase form; and a solid-liquid separation step.

Abstract: An object of the present invention is to provide a method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method of the present invention as a means for resolution is characterized by including at least a step of separating a rare earth element in the form of an oxide from an iron group element by subjecting a workpiece to an oxidation treatment, then turning the treatment environment into an environment where carbon is present, and subjecting the oxidation-treated workpiece to a heat treatment at a temperature of 1150° C. or more.

Abstract: An object of the present invention is to provide an R—Fe—B based sintered magnet that exhibits excellent corrosion resistance and maintains excellent adhesion strength to an adherend even under severe conditions, and a method for producing the same. A corrosion-resistant magnet of the present invention as a means for achieving the object is characterized by comprising a chemical conversion film containing at least Zr, V, Al, fluorine, and oxygen as constituent elements and not containing phosphorus over a surface of an R—Fe—B based sintered magnet with a film made of Al or an alloy thereof therebetween.

Abstract: It is an objective of the present invention to provide a technique to balance DSV in channel bit word when using fixed-length run length limited code based on enumeration. A channel bit word processor according to the present invention: evaluates DSV of a channel bit word in NRZI format which is generated on the basis of enumeration; and selects a connection word which causes a minimum absolute value of DSV after connecting a plurality of channel bit words (refer to FIG. 15).

Abstract: An object of the present invention is to provide a method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a heavy rare earth element from a workpiece containing at least a heavy rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least the following step: a workpiece is subjected to an oxidation treatment or mixed with an oxidation-treated R—Fe—B based magnet alloy, and then subjected to a heat treatment in the presence of carbon at a temperature of 1000° C. or more, thereby separating a heavy rare earth element in the form of an oxide from an iron group element.

Abstract: An object of the present invention is to provide a method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element of the present invention as a means for resolution is characterized by including at least a step of separating a rare earth element in the form of an oxide from an iron group element by subjecting a workpiece to an oxidation treatment, then turning the treatment environment into an environment where carbon black is present, and subjecting the oxidation-treated workpiece to a heat treatment at a temperature of 1000° C. or more in an inert gas atmosphere or in vacuum.

Abstract: An objective of the present invention is to provide a rare earth metal-based sintered magnet having imparted thereto sufficient corrosion resistance by an oxidative heat treatment, which is resistant even in an environment of fluctuating humidity, while suppressing the deterioration of the magnetic characteristics ascribed to the oxidative heat treatment, and to provide a method for producing the same.

Abstract: An objective of the invention is to provide a method and system for separating a particular rare earth element from a rare earth magnet at a high separation ratio and by a simple process. There is provided a rare earth separation method for separating a first and a second groups of rare earth elements contained in a magnet, the method including: a starting powder preparation step from the magnet; a magnet component oxidation heat treatment step; a rare earth oxide separation step from the magnet components oxide powder; a powder size optimization step; a chlorinating agent mixing step; a chlorination/oxychlorination heat treatment step of forming a “first group rare earth chlorides”/“second group rare earth oxychlorides” mixture; a selective dissolution step of selectively dissolving the first group rare earth chlorides in the solvent and leaving the second group rare earth oxychlorides undissolved in solid phase form; and a solid-liquid separation step.

Abstract: It is an objective of the present invention to provide a technique, when using fixed-length run-length limit codes based on enumeration, that generates fixed-length channel bit words satisfying maximum run-length limitation using a simple configuration. A channel bit word processor according to the present invention includes an avoidance list that describes a difference between a user bit word satisfying a maximum run-length limitation of run-length limit code and a user bit word not satisfying the maximum run-length limitation. The channel bit word processor, if a user bit word does not satisfy the maximum run-length limitation, generates a channel bit word using a user bit word after the difference is added.

Abstract: In the optical information reproduction apparatus using Homodyne phase diversity detection, the S/N ratio of a reproduced signal is deteriorated due to the influence of a quantization noise generated in an A/D converter for digitalizing a differential signal. The optical information reproduction apparatus is arranged to have the A/D converter for digitalizing the differential signal having a vertical resolution equal to or higher than 9 bits.

Abstract: An optical disc device and information recording/reading method for an optical disc in which a recording layer is formed through volume recording by aligning recording tracks, which hold information, in a homogenous recording region that does not internally have a layer defining a recording position. The information recording method includes a step in which a first recording layer forming a complex recording layer is formed by forming a recording track while recording information by focusing a main beam at a predetermined depth position in the recording region, and a step in which a second recording layer forming the complex recording layer is formed by forming a recording track while recording information by focusing the main beam at a depth position that is separated from the first recording layer in a depth direction by a depth offset greater than ? of a wavelength of the main beam.

Abstract: It is an objective of the present invention to provide a technique, when using fixed-length run-length limit codes based on enumeration, that generates fixed-length channel bit words satisfying maximum run-length limitation using a simple configuration. A channel bit word processor according to the present invention includes an avoidance list that describes a difference between a user bit word satisfying a maximum run-length limitation of run-length limit code and a user bit word not satisfying the maximum run-length limitation. The channel bit word processor, if a user bit word does not satisfy the maximum run-length limitation, generates a channel bit word using a user bit word after the difference is added.

Abstract: Patterns that might be generated due to a burst error are prepared beforehand. These patterns are formed by shifting all “1”s in an original channel word. A list of these patterns generated as described above is retrieved in parallel with a general conversion table during demodulation. When the demodulation is interrupted due to the burst error, the result of the retrieval of the previous pattern is referred to, and when there is a hit, the error is regarded as the burst error of the original channel word, and the demodulation is continued.

Abstract: In the land-groove method, wobble interference is reduced. STW modulation is used as wobble modulation for a part where wobble interference can occur, for example, a part where the configurations of both side walls of the groove are not the same and groove width modulation is unavoidable. Thereby, the amplitude of the groove width modulation can be suppressed to a quarter of that when BPSK modulation is used.

Abstract: An object of the present invention is to provide a method for recovering a rare earth element from a workpiece containing at least a rare earth element and an iron group element, which can be put into practical use as a low-cost, simple recycling system. The method of the present invention as a means for resolution is characterized by including at least a step of separating a rare earth element in the form of an oxide from an iron group element by subjecting a workpiece to an oxidation treatment, then turning the treatment environment into an environment where carbon is present, and subjecting the oxidation-treated workpiece to a heat treatment at a temperature of 1150° C. or more.

Abstract: An object of the present invention is to provide a method for producing an alloy recycled material by effectively removing carbon from a carbon-containing alloy, which is produced as scrap or sludge of an R—Fe—B based permanent magnet, a used magnet, or the like. The method of the present invention as a means for resolution is characterized in that a carbon-containing R—Fe—B based permanent magnet alloy is subjected to an HDDR treatment to remove carbon. An alloy recycled material produced by the method of the present invention contains a reduced amount of carbon. Therefore, in the case where it is recycled for the production of a magnet, even when an increased amount is subjected to high-frequency heating in a vacuum melting furnace, a non-negligible increase in the amount of carbon contained in the produced magnet can be avoided.

Abstract: A read signal evaluating means for ensuring compatibility in an optical phase multilevel recording and reading system is provided. In addition, a decoding means not large in circuit scale is provided. An optical phase is modulated based on user data, and phase information thus obtained is recorded in a recording medium. Then, the phase information recorded in the recording medium is optically read, and is converted into an electric signal. The signal is subjected to adaptive equalization and to partial response most-likely decoding. A shift in a time axis direction from a target wave of a predetermined pattern is detected from the read phase information and a statistical average is calculated. Meanwhile, a value of the phase read from the predetermined pattern is extracted from the read phase information and a statistical average is calculated.