Abstract: The present invention provides an abrasive composition for polishing magnetic recording disk substrates that results in a low surface roughness of the magnetic recording disk, allows the attaining of high-density recording without the occurrence of protrusions or polishing scratches, and enables polishing to be performed at an economical speed. The present invention discloses an abrasive composition for polishing magnetic recording disk substrates comprising water, silicon dioxide, antigelling agent, aluminum nitrate and hydrogen peroxide.

Abstract: A magnetic reproducing device which includes a signal detecting means for detecting a signal from a magnetic recording medium by a coil, an amplifying means for amplifying the signal detected by the signal detecting means, a filtering means for filtering the signal amplified by the amplifying means, and a capacitor connected in parallel to the coil of the signal detecting means. In this device, the actual resonance frequency of a resonance circuit including the coil, the capacitor and a floating capacitance is set to be four to eight times the maximum reproduced frequency, thereby attenuating the high-frequency high-energy electromagnetic noise inputted to the magnetic reproducing device.

Abstract: The wiring case has a detachable display device for displaying contents of data and electric transmission/reception communications established with a predetermined controlling device. In the display device, a pair of wiring members are prepared. The tip end portions of the wiring members are directed towards the bottom surface portion of the wiring case, and the each tip end portion has a contact point. The wiring case has an opening at a section opposing to the bottom surface portion, and a stopper portion is formed at end portion of each of sidewalls of the long-scale box.

Abstract: A magnetic hard disc substrate made of an aluminum alloy for memory devices such as a computer must correspond to an improved structure in which the interval between a head and a medium is made narrower to attain high density recording. In order to prevent head crash, it is required that the magnetic hard disc substrate have a smooth surface and decreased defects. The present invention provides a process for manufacturing a magnetic hard disc substrate made of an aluminum alloy which satisfies the above requirements and also provides a disc substrate which has a surface roughness Ra≦0.5 nm and is free from abrasive flaws with a depth of 5 nm or more and from micro-waviness or provides a disc substrate which has a surface roughness Ra≦5 angstroms and a surface roughness Rmax≦80 angstroms and in which the number of scratches with a depth of 50 angstroms or more is 5 or less and the number of pits with a depth of 50 angstroms or less is 5 or less in the surface.

Abstract: Magnetic disk substrates are produced by subjecting glass substrates to at least steps of degreasing, etching, sensitization with tin chloride, activation and sensitivity-enhancing treatment in that order, then plating the pretreated substrates with a nickel/phosphorus film, and thereafter polishing the plated substrates. In the process, the substrates being processed are washed with hot pure water at a temperature of not lower than 50° C. for a period of from 20 to 90 seconds, after the sensitization step but before the activation step, and heated at a temperature of not lower than 70° C. for a period of from 5 to 100 minutes, after the sensitization step but before the nickel/phosphorus-plating step.

Abstract: The wiring case has a detachable display device for displaying contents of data and electric transmission/reception communications established with a predetermined controlling device. In the display device, a pair of wiring members are prepared. The tip end portions of the wiring members are directed towards the bottom surface portion of the wiring case, and the each tip end portion has a contact point. The wiring case has an opening at a section opposing to the bottom surface portion, and a stopper portion is formed at end portion of each of sidewalls of the long-scale box.

Abstract: A receiver side of a two-wire type remote control system accurately determines the polarity of data. The reception buffer inverts an input from one of the data and electric communication lines, and adds the inverted input to an input of the other line. Then, when the result of the addition is 0 or close to 0, the reception switches buffer logic data to be output to indicate the inversion of the level of the equilibrium pulse-like power received from the communication lines. The polarity identifying portion identifies the polarity when the logical data sent from the reception buffer is maintained at a logic level for a predetermined period of time. The polarity identifying portion sends pulse group data to the data processing portion in accordance with the identified polarity.

Abstract: The present invention provides an abrasive composition for polishing magnetic recording disk substrates that results in a low surface roughness of the magnetic recording disk, allows the attaining of high-density recording without the occurrence of protrusions or polishing scratches, and enables polishing to be performed at an economical speed. The present invention discloses an abrasive composition for polishing magnetic recording disk substrates comprising water, silicon dioxide, antigelling agent, aluminum nitrate and hydrogen peroxide.

Abstract: A provision of a magnetic disk substrate using, as a plated substrate, glass with high hardness in place of aluminum. The magnetic disk substrate is small-sized, can stand against an impact when it is carried, and avoids leaving struck damages (head snap) even if it is used for recent note- or mobile-type computers having a head which is located as closely as possible to the substrate. The magnetic disk substrate comprises forming a nickel/phosphorus coating with a film thickness of 8 &mgr;m-20 &mgr;m or less on crystallized glass with a roughness Ra of 0.05 to 0.5 &mgr;m, the roughness being measured by a tracer and contact type roughness meter after the glass is ground (lapped) and polishing the nickel/phosphorus coating to a depth of 3 &mgr;m or more in a polishing process with the thickness of the plating film left unremoved being 5 &mgr;m or more.

Abstract: A magnetic hard disc substrate made of an aluminum alloy for memory devices such as a computer must correspond to an improved structure in which the interval between a head and a medium is made narrower to attain high density recording. In order to prevent head crash, it is required that the magnetic hard disc substrate have a smooth surface and decreased defects. The present invention provides a process for manufacturing a magnetic hard disc substrate made of an aluminum alloy which satisfies the above requirements and also provides a disc substrate which has a surface roughness Ra.ltoreq.0.5 nm and is free from abrasive flaws with a depth of 5 nm or more and from micro-waviness or provides a disc substrate which has a surface roughness Ra.ltoreq.5 angstroms and a surface roughness Rmax.ltoreq.80 angstroms and in which the number of scratches with a depth of 50 angstroms or more is 5 or less and the number of pits with a depth of 50 angstroms or less is 5 or less in the surface.

Abstract: An aluminum foil to be etched for use as the electrolytic condenser electrodes is composed of a foil body of an aluminum purity of 99.9% or higher, and an oxide layer 20-70 .ANG. thick and formed due to contact of the foil body with an oxidizing atmosphere. At least one etching nuclei-forming element is concentrated in a boundary region and/or in an outermost surface region of the oxide layer, the boundary region being disposed between the foil body and the oxide layer, and both the regions having a thickness of 20 .ANG. or less. The ratio in ion intensity of a maximum concentration of the elements in these regions to a concentration of the elements in the inner layer of the foil body is 1.2-30. There are three patterns in distribution of the elements, so that the maximum concentration is in a predetermined ratio to the concentration in the surface region, the inner layer or a minimum concentration appearing between the regions.

Abstract: Aluminum foils used as a material of electrodes in electrolytic capacitors are manufactured by a method which comprises a step of forming at first an initial internal oxide coating 5 to 50 .ANG. thick on the surface of the aluminum foils before they are electrochemically or chemically etched later. The aluminum foils are then subjected to high temperature heat treatment such that the whole thickness of the oxide coating does not exceed 70 .ANG..

Abstract: An inquiry system is provided for detecting the location of a selected object. The system comprises an answering device having its own identifying address which responds to a detecting command. An answering device is provided on each object to be selected. The detecting command is transmitted from a controller device which communicates with the answering devices through the use of an address.

Abstract: A substrate for amorphous silicon solar cells comprises an aluminum or aluminum alloy plate which is formed on at least one surface thereof with an oxalic acid anodized film in an unsealed state and having a thickness of 1 to 20 .mu.m. A plurality of amorphous silicon solar cells provided on the substrate include lower electrodes of chrominum or the like which are formed on the anodized film. The lower electrodes are electrically insulated from one another by the anodized film.