Abstract: Embodiments in accordance with the present invention relate to identifying an address of user data to be registered as a defective user data address in disk defect inspection. In an embodiment of the present invention, in the state where a write element is positioned to a target position to execute data write processing to execute normal data read processing, a write element executes data write processing. If a predefined error occurs during the data write processing, an address of user data for which the normal data write processing is executed is estimated using the error-causing servo data as a target. In addition, an address of the servo data used as the target during the normal data write processing for the estimated address of the user data is identified. If the identified address of the servo data and the address of the error-causing servo data match with each other, the estimated address of the user data is registered as a defective user data address.

Abstract: Embodiments of the present invention provide a defect registration method for performing defect registration of sectors on a magnetic disk. In one embodiment, a rectangular detection window is applied to each defect sector. A threshold value of the detection window is set at 2. In addition, an additional sector group is defined for the detection window. The additional sector group is a target of the defect registration if the number of defect sectors exceeds the threshold value. The additional sector group covers sectors that are not judged as defects in defect detection inspection, but that are expected to be potentially defective. Even if the detection window is applied to a defect sector, an additional sector group is not generated. However, if the detection window is applied to a defect sector, an additional sector group is generated. If the detection window is applied to a defect pattern, an additional sector group is generated.

Abstract: Embodiments in accordance with the present invention erase a desired area on a recording surface of disk or disk drive apparatus. According to an embodiment, a hard disk drive (HDD) performs erase on a recording surface by moving a head element unit at one-half a servo track pitch with reference to a servo address. Before actual erase is started on the recording surface, the HDD generates a management table configured based on servo addresses from a management table configured based on data tracks. At an erase process, the HDD sets parameters in accordance with the zone and skips a management area with reference to this management table based on the servo addresses.

Abstract: Embodiments in accordance with the present invention erase a desired area on a recording surface of disk or disk drive apparatus. According to an embodiment, a hard disk drive (HDD) performs erase on a recording surface by moving a head element unit at one-half a servo track pitch with reference to a servo address. Before actual erase is started on the recording surface, the HDD generates a management table configured based on servo addresses from a management table configured based on data tracks. At an erase process, the HDD sets parameters in accordance with the zone and skips a management area with reference to this management table based on the servo addresses.

Abstract: Embodiments in accordance with the present invention relate to identifying an address of user data to be registered as a defective user data address in disk defect inspection. In an embodiment of the present invention, in the state where a write element is positioned to a target position to execute data write processing to execute normal data read processing, a write element executes data write processing. If a predefined error occurs during the data write processing, an address of user data for which the normal data write processing is executed is estimated using the error-causing servo data as a target. In addition, an address of the servo data used as the target during the normal data write processing for the estimated address of the user data is identified. If the identified address of the servo data and the address of the error-causing servo data match with each other, the estimated address of the user data is registered as a defective user data address.

Abstract: Embodiments in accordance with the present invention increase the possibility that a servo track in which servo data is defective may be detected, greatly decreasing the possibility that a write error may occur during use by a user. According to one embodiment of the present invention, a defective area management method for a data storage device is provided. The data storage device comprises a head in which positions of read and write elements differ from each other in the radial direction of a disk. A defective area management method performs positioning of the head by reading out servo data written on the disk using the read element.

Abstract: Embodiments of the present invention provide a defect registration method for performing defect registration of sectors on a magnetic disk. In one embodiment, a rectangular detection window is applied to each defect sector. A threshold value of the detection window is set at 2. In addition, an additional sector group is defined for the detection window. The additional sector group is a target of the defect registration if the number of defect sectors exceeds the threshold value. The additional sector group covers sectors that are not judged as defects in defect detection inspection, but that are expected to be potentially defective. Even if the detection window is applied to a defect sector, an additional sector group is not generated. However, if the detection window is applied to a defect sector, an additional sector group is generated. If the detection window is applied to a defect pattern, an additional sector group is generated.

Abstract: A method for registering a defect map within a hard disk drive is disclosed. A hard disk drive includes a recording disk, a head assembly, and a controller. Multiple sectors are formed on the recording disk, and the head assembly includes a head for reading/writing data from/to the recording disk. The controller, which controls the head assembly to read/write data from/to the recording disk, includes a defect sector positional information holding device and a sector identification device. The defect sector positional information holding device holds positional information of a defect sector disabled to read/write data therefrom/thereto the recording disk. The positional information includes the number of the defect sectors continued in a circumferential direction and in a radial direction of the recording disk.

Abstract: A method for registering a defect map within a hard disk drive is disclosed. A hard disk drive includes a recording disk, a head assembly, and a controller. Multiple sectors are formed on the recording disk, and the head assembly includes a head for reading/writing data from/to the recording disk. The controller, which controls the head assembly to read/write data from/to the recording disk, includes a defect sector positional information holding device and a sector identification device. The defect sector positional information holding device holds positional information of a defect sector disabled to read/write data therefrom/thereto the recording disk. The positional information includes the number of the defect sectors continued in a circumferential direction and in a radial direction of the recording disk.

Abstract: The present invention discloses a master cylinder MC, which comprises a body section 2, a cap 3, a cylinder housing 1 composed of the body section 2 and the cap 3, a sleeve 8 fitted in the cylinder housing 1, primary and secondary pistons 4 and 5 provided to be guided by the sleeve 8 and slid, first and second pressure chambers 9 and 10 and spring mechanisms 11 and 12 respectively disposed in the first and second pressure chambers for pressing the primary and secondary pistons 4 and 5 in returning directions. In the peripheral portion 17a of the spring retainer 17 of the spring mechanism 11 for pressing the primary piston 4, hook sections 17e are formed by protruding a plurality of portions 17d outward in an axial direction and then folding the tip of each of the protruded portions in a piston axial direction so as to hook the same in the outer peripheral surface of the sleeve 8.

Abstract: A cap which is so constructed that parts manufacture and product assembly are facilitated. The construction is such that a cap for a master cylinder reservoir connects a cover cap and a body cap with each other and a diaphragm is disposed in a space formed therebetween to provide a valve function. The cover cap has a concentric cylindrical portion and an annular protrusion, while the body cap has a funnel portion at its center and an annular disc portion at the periphery of the funnel portion. The diaphragm is fitted between the inner periphery of annular protrusion of the cover cap and the outer periphery of the funnel portion of the body cap. The diaphragm forms a suction valve and an exhaust valve together with the cylindrical portion and the annular disc portion, respectively.

Abstract: A pyrrole polymer membrane having electrical conductivity and liquid crystal properties in the same matrix. The starting pyrrole monomer derivative is illustrated by the formula ##STR1## where R.sub.1 and R.sub.2 are selected so that at least either of them is an electron attractive group. Methods of producing such membranes by a electropolymerization process and by a chemical oxidation process are described.

Abstract: A plurality of communication terminals are coupled to one telephone line via a plural terminals communication controlling system having circuits for detecting on-hook/off-hook of the communication terminals and a time supervising circuit. In the case where a transmission side has no selection signal transmission function, a first communication terminal is called by the transmission side. Even if this first communication terminal is a telephone set and there is no response because of the absence of a called party, a second communication terminal is called after a predetermined period of time, so that a desired communication is established between the transmission side and the second communication terminal by using a facsimile as the second communication terminal.

Abstract: In an apparatus for manufacturing a taper leaf spring, by which after performing rolling on the edges of a sheet spring material in the direction of its breadth, rolling for tapering the sheet in the direction of its thickness is carried out, an edge roll assembly is employed for the sake of rolling in the breadth direction. In the edge roll assembly, constraining flanges for regulating the sheet thickness are provided on both ends of the main body of the edge roll so that expansion of both sides of a sheet spring material in the sheet thickness direction due to the effect of rolling in the sheet breadth direction is suppressed by the flanges and the thickness of a sheet spring material is kept uniform as a whole prior to performing rolling in the sheet thickness direction.