Abstract: The photoelectric encoder of the present invention has a light-emitting device and light-receiving devices arranged in one direction in a region that light from the light-emitting device can reach. When a moving object that alternately has a light-on portion that produces a state in which light is incident on the light-receiving device and a light-off portion that produces a state in which light is not incident on the light-receiving device passes at a prescribed movement frequency in the one direction, an output of each of the light-receiving devices takes a value corresponding to the incidence or nonincidence of light on the light-receiving device. A logical operating section carries out operation of the logical values expressed by the outputs of the light-receiving devices to form an output signal that has a frequency different from the movement frequency.

Abstract: The photoelectric encoder of the present invention has a light-emitting device and light-receiving devices arranged in one direction in a region that light from the light-emitting device can reach. When a moving object that alternately has a light-on portion that produces a state in which light is incident on the light-receiving device and a light-off portion that produces a state in which light is not incident on the light-receiving device passes at a prescribed movement frequency in the one direction, an output of each of the light-receiving devices takes a value corresponding to the incidence or nonincidence of light on the light-receiving device. A logical operating section carries out operation of the logical values expressed by the outputs of the light-receiving devices to form an output signal that has a frequency different from the movement frequency.

Abstract: A magnetic recording medium is obtained, which satisfies R−9709/N<6.6, when its surface is attracted by a magnetic head with a surface pressure of 250 gf/mm2 or less or has a load area ratio of 5% or less, where N is the number of asperities per &mgr;m square and R (nm) is an average of radii of curvature at peaks of the asperities. This magnetic recording medium does not cause dynamic attraction even if the head contact slides with it, and rotates stably, so that information can stabily be written/read well.

Abstract: A magnetic disk drive for carrying out reading/writing of information to/from a magnetic disk having a plurality of tracks including an innermost circumference track and an outermost circumference track. The disk drive includes a rotary actuator and a magnetic head mounted on a magnetic head slider which has separate writing and reading elements. The elements have a magnetic gap for reading and writing the information on a magnetic disk. A rotary actuator arm has one end connected to a rotary actuator and the other end connected to the magnetic head slider. The head slider has an inflow end and an outflow end for the fluid flow generated by the rotation of the disk and at least one bearing which generates a dynamic pressure by the fluid flow. The head is provided close to the outflow. A skew angle created between the magnetic gap length direction and the rotating direction of the disk is substantially constant between the innermost and the outermost tracks.

Abstract: On a head slider 203a, a read/write head 20 for reading and/or writing information on a disk being a rotatable recording medium is mounted. The head slider 203a comprises: a head slider body; a dynamic-pressure generating part 2a (2b) for generating a dynamic pressure, the dynamic-pressure generating part being formed on a surface of the head slider body facing the disk; and a negative-pressure generating part 81a (81b) for generating a negative pressure, the negative-pressure generating part being provided on a plane of the head slider body facing the disk and in the rear of a central portion of the head slider body in a rotating direction of the disk. Thus, it is possible to provide a head slider having a small yaw-angle dependence, and a read/write apparatus, which has the head slider and which is capable of improving the recording density thereof.

Abstract: Disclosed is an aluminium nitride sintered body composed of a sintered body of aluminum nitride, erubium (Er) metal or its compound and calcium (Ca) metal or its compounds, said sintered body containing 1.8 to 10% by weight of an erubium component calculated as an oxide and more than 0 to not more than 2% by weight of a calcium component calculated as an oxide, and consisting of crystal grains of aluminum nitride and an intergranular phase composed mainly of an aluminate other than Er.sub.3 Al.sub.5 O.sub.12, said sintered body further having a bulk density of 3.2 to 3.6 g/cm.sup.3.