Abstract: An optical disc recording and reproducing apparatus realizes stable tracking control for correcting the displacement of an objective lens caused by gravity depending on the positional attitude of the apparatus.

Abstract: An ink head according to one aspect of the present invention includes an ink head module and a nozzle plate. The ink head module has a plurality of ink chambers in which ink is retained. The nozzle plate is attached to the ink head module. The nozzle plate has at least one nozzle to jet ink inside the ink chamber. The surface of the nozzle plate opposing to a recording medium has a first region coming in contact with an opening of the nozzle and a second region other than the first region. Water repellency of the first region is higher than that of the second region.

Abstract: An ink jet head includes four plate-like piezoelectric bodies each having a primary surface having a plurality of parallel grooves formed therein in a predetermined direction, a end surface on which a one end of the groove is open, and an electrode formed on the inner surface of the groove. These piezoelectric bodies are stacked one upon the other on the primary surfaces under the state that the openings of these piezoelectric bodies are allowed to face the same direction, and that the primary surfaces of these piezoelectric bodies are allowed to face the same direction. Further, formed is a common liquid supply path allowing the plural grooves of the piezoelectric bodies to communicate with each other to form ink flow path.

Abstract: In a CLV control of a spindle motor, a clock extracting unit (5) extracts a clock component from the reproduction data, and a CLV control unit (6) controls the spindle motor (8) in accordance with the extracted clock component to rotate the optical disk in a CLV mode, while a rotational velocity detecting unit (14, 15) detects a frequency or period value corresponding to a rotational velocity of the spindle motor (8) and a CAV control unit (16) controls the spindle motor (8) in accordance with the rotational velocity of the spindle motor detected by the rotational velocity detecting unit to thereby rotate the optical disk in a CAV mode.

Abstract: In the case where a CPS unit (9) detects a period of clock components of reproduction data to be within a given range, the spindle motor (8) is driven in the CLV mode in stable and the mean value or the low-frequency components of the drive signal data (Smd) during a given time period is stored in the memory unit (11), and in the meanwhile, when the clock components of the reproduction data can not be extracted, the spindle motor is driven in accordance with the mean value or low-frequency components stored in the memory unit. In the case where the reproduction data per se including the clock signal components for use in the CLV control is not obtained due to cracks and stains on the optical disk or due to external shock or vibrations applied from the outside, the stable rotation of the optical disk can be maintained for reproducing the data without causing undesirable burst rotation of the optical disk.

Abstract: A magnetic recording medium comprising a non-magnetic support, and a magnetic recording layer formed on the support. The layer is made of a composition which comprises magnetic powder dispersed in a resin binder comprising a thermosetting resin and a copolymer of maleic anhydride and an olefinically unsaturated monomer. The monomer is selected from alkyl esters of acrylic and methacrylic acids, alkenes, vinyl chloride, styrene and mixtures thereof.

Abstract: A magnetic recording material which comprises a non-magnetic substrate, and a magnetic layer formed on at least one surface of the substrate. The magnetic layer is made of a uniform dispersion of a magnetic powder in a mixture of epoxy and urea resins used in an amount from 40 to 200 wt % of the magnetic powder.

Abstract: A device for orienting magnetic particles contained in a magnetic layer on a disc-shaped magnetic recording medium along the circumference of the recording medium. The magnetic layer is provided on a substrate. The orientation is effected by a magnetic field developed by a pair of permanent magnets and which the recording medium traverses during rotation. The permanent magnets are individually shaped flat and arranged to oppose each other at their pole-faces which are common in polarity. A trailing edge of each magnet located with respect to relative movement of the rotating recording medium extends and aligns with the radius of the recording medium.