Abstract: A pressure regulating valve (20) for adjusting a pressure of a supply/discharge passage (10) to a pressure balanced against a weight of a body to be carried (1) is provided. The supply/discharge passage (10) is connected to a working chamber (8) of a cylinder (2) for raising and lowering the body to be carried (1). A control valve (38) for increasing and decreasing a pressure in a control passage (28) in accordance with a balance between the weight of the body to be carried (1) and a working force in a reaction force chamber (42) to which a pilot pressure is introduced from the control passage (28) is also provided.

Abstract: An optical disk includes a plurality of tracks that are arranged in a predetermined number of zones. Each track is divided into a plurality of sectors. The sector number is different in each zone. The sector increases in number moving outwardly on the disk. The optical disk also includes a format marking. The format marking includes a sector field for each sector. The format marking is erasably recorded.

Abstract: An equalizer for producing an equalized signal from an input signal. The input signal has a DC component. The equalizer includes a programmable filter and equalizer. A detector for generating a threshold signal from a preprocessed signal. The preprocessed signal is generated from the equalized signal. A comparator for comparing the preprocessed signal to the threshold signal to produce an output signal. A tracking device for tracking the DC component from the output signal.

Abstract: An encoder converts a binary data word to a binary code word. The encoded bits have first and second binary values at a predetermined clock interval. A pulse generator responds to the encoded bits to generate energizing pulses during each clock interval in which the encoded bits have the first binary value. The energizing pules have a uniform duration less than the clock interval. A laser responds to the energizing pulses for recording on a medium.

Abstract: An encoder converts a binary data word to a binary code word. The encoded bits have first and second binary values at a predetermined clock interval. A pulse generator responds to the encoded bits to generate energizing pulses during each clock interval in which the encoded bits have the first binary value. The energizing pules have a uniform duration less than the clock interval. A laser responds to the energizing pulses for recording on a medium.

Abstract: An apparatus for recording data includes a source of digital data arranged into data words having a given number of bits and a converter that converts the data words to code words having one more bit than the given number using a group code recording format. The code words include a binary signal having first and second binary values at a given clock interval determined by a bit rate of the code words. The apparatus also includes a storage disk having a recording surface, a drive member for rotatably driving the disk, a laser having a focused beam, and a control assembly for directing the laser at the recording surface so that the beam accesses one of a plurality of concentric tracks on the recording surface. A circuit assembly provides a driving signal utilized for generating energizing pulses having a duration less than the clock interval when the binary signal has the first binary value.

Abstract: A high density optical disk that includes a plurality of tracks and a format marking. The tracks are arranged in a predetermined number of zones. Each track is divided into a plurality of sectors. The number of sector is different in each zone and is increased as it is moving outwardly on the optical disk. The format marking includes a sector field for each sector. The format marking is erasable recorded.

Abstract: There is disclosed a pyrolytic boron nitride double container for a source of molecular beams used in molecular beam epitaxy, wherein the transmissivity of an inner container of the pyrolytic boron nitride double container with respect to light having a wave number of 2600 cm−1 to 6500 cm−1 is 90% or less of that of an outer container. The pyrolytic boron nitride double container, which enables molecular beams to generate stably with good temperature controllability and high heat efficiency and which can be used in a stable manner, is provided through a simple process and at low cost, so that molecular beam epitaxial growth can be stabilized, quality of the epitaxial film can be improved, and even though the rise and drop in the temperature of the material melt is repeated, or even at an emergency suspension of the operation, the trouble due to breakage of the container can be prevented.

Abstract: A transportable apparatus for preventing the spreading and coming ashore of spilled oil that is easily transportable to a sea area where spilled oil is spread and that can perform the operation of preventing the spreading and coming ashore of spilled oil in the open area. The apparatus has an oil-fence-housing robot ship (10) and a pair of oil-fence-setting-up robot ships (20, 30) that are separably coupled together into an easily transportable block body. The apparatus encircles a sea area where spilled oil is spread with oil fences (40, 41) by remotely operating the robot ships (10, 20, 30) via radio signals.

Abstract: There is disclosed a pyrolytic boron nitride container for accommodating a material serving as a source of molecular beams for molecular beam epitaxy, wherein the transmissivity of the pyrolytic boron nitride container with respect to light having a wave number of 2600 cm−1 to 6500 cm−1 has a profile such that the transmissivity changes in the height direction of the container. The pyrolytic boron nitride container can be manufactured through a simple process and at low cost. The pyrolytic boron nitride container can prevent material melt from rising along the inner wall surface and prevent splashed material melt from adhering to the upper portion of the container. Further, the pyrolytic boron nitride container can stabilize molecular beam epitaxial growth and improve the quality of epitaxial film.

Abstract: Disclosed is a crucible of pyrolytic boron nitride (PBN) for molecular beam epitaxy for melting of the source material, with which the troubles due to adhering of the molten source material in the form of drops caused on the quality of the epitaxial layer can be greatly decreased. Namely, the inner surface of the crucible is free from pits or other irregularities responsible to the adhering of the melt when the growth plane, which can be exposed by stripping of the surface layer of 0.50 mm thickness by cleavage, has a surface roughness Ra not exceeding 2.0 .mu.m and Rmax not exceeding 18 .mu.m. Such a PBN crucible can be prepared by the CVD method to deposit PBN on the surface of a graphite core of which the surface roughness Ra does not exceed 2 .mu.m.

Abstract: There is disclosed a pyrolytic boron nitride container used for a Boat method in which material melt is retained In the container, and a crystal is grown while a temperature gradient is imparted to the material melt. The transmissivity of the pyrolytic boron nitride container with respect to light at a wave number ranging from 3700 cm.sup.-1 to 6500 cm.sup.-1 has a profile such that the transmissivity monotonously changes in the longitudinal direction of the container. The transmissivity profile is produced by imparting a pressure profile during manufacture of the container through deposition of pyrolytic boron nitride, by roughing the outer surface of the container such that the surface roughness has a profile, or by compounding pyrolytic boron nitride with a different material. It becomes possible to facilitate generation of a temperature gradient in material melt within the container and to facilitate control of a temperature profile in the container.

Abstract: An apparatus and method for retrieving densely stored data from various types of magnetic media. A medium is scanned to provide an input signal. The input signal is conditioned through differentiation, equalization and partial integration. Positive and negative signal peak detectors are connected to the conditioned signal, and a threshold signal is generating corresponding to an average or midpoint of the measured positive and negative signal peaks. An output signal is generated by comparing the conditioned signal and the threshold signal. The DC component of the input signal is accounted for by feeding back the output signal and adjusting the threshold signal based on the duty cycle of the output signal.

Abstract: An improvement is proposed in the preparation of, for example, a ceramic heater consisting of a substrate plate of boron nitride, a patterned layer of pyrolytic graphite (PG) on the substrate to serve as an electric resistance element and an overcoating layer of pyrolytic boron nitride (PBN) in a process comprising the steps of depositing PG on the substrate surface, pattern-wise removing the PG layer by mechanical working to form grooves and depositing PBN all over. According to the inventive improvement, which can be obtained by forming the grooves in such a fashion that the angle between the direction of a normal line to the facet surface formed by the mechanical working and the growing direction of the substrate of boron nitride is in the range from 0.degree. to 45.degree. so that the internal stress caused in the overcoating layer, which is due to the anisotropy in the thermal expansion of boron nitride, is decreased to prevent the overcoating layer from occurrence of cracks and falling during service.

Abstract: A first write encoder encodes digital data in a first, high-density format. A second write encoder encodes digital data in a second, low-density (i.e., ANSI) format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first write encoder is connected between a source of digital data and the read/write head, and the first read decoder is connected between the read/write head and the utilizing apparatus. In a second mode, the second write encoder is connected between the source and the read/write head, and the second read decoder is connected between the read/write head and the utilizing apparatus.

Abstract: A data generator assembly for use in retrieving stored data from an information storage medium. The data generator assembly includes a positive peak detector for receiving a preprocessed signal having a predetermined waveform including positive peaks, negative peaks, and a DC component. The positive peak detector is utilized to measure and track the positive peaks to output a positive peak signal. A negative peak detector measures and tracks the negative peaks to output a negative peak signal. The data generator assembly also includes a voltage divider for averaging the negative peak signal and the positive peak signal and generating a threshold signal representing the approximate peak-to-peak midpoint of the preprocessed signal which varies with the DC component. A comparator is provided for comparing the preprocessed signal with the threshold signal. The comparator generates an output data waveform signal indicative of the stored data on information storage medium.

Abstract: Although a workpiece can be elevated or lowered according to the invention, the workpiece is prevented from rising or falling abruptly. When the workpiece is elevated with an external force, air supplied from the side of an auxiliary air supply chamber pushes down a pressure control piston. Since a difference in pressure between the side of a piston pressure chamber and the side of an auxiliary air supply chamber is small, air is prevented from flushing from the side of the auxiliary air supply chamber into the piston pressure chamber. When the workpiece is lowered with an external force, the pressure control piston is pushed up, thereby increasing the pressure in the piston pressure chamber. At the same time, a relief valve is opened and the piston pressure chamber is exhausted. By the provision of a relief valve, excess air is not exhausted from the piston pressure chamber. The pressure control piston is prevented from rising abruptly, and the workpiece can be gradually raised or lowered.

Abstract: A first write encoder encodes digital data in a first high density format. A second write encoder encodes digital data in a second low density, i.e. ANSI format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first encoder is connected between a source of digital data and the read/write head, and the first decoder is connected between the read/write head and utilizing apparatus. In a second mode, the second encoder is connected between the source and the read/write head, and the second decoder is connected between the read/write head and the utilizing apparatus. Control electronics switches between the first and second modes, depending upon the format in which data is recorded on the disk received by the disk drive.

Abstract: A pyrolytic boron nitride crucible is disclosed which is suitable for producing a single crystal of a semiconductor compound of Group III and V by the LEC method. The crucible comprises a side part and a bottom part. The bottom part has an absorption coefficient of light of wavelengths between 3,700 cm.sup.-1 and 6,500 cm.sup.-1 of at most 1.7 and/or the absorption coefficient of light of wavelengths between 3,700 cm.sup.-1 to 6,500 cm.sup.-1 of the bottom part is less than that of the side part by at least 0.5. In the crucible, the heat conduction from the bottom part to material melt in the crucible is strengthened, so that the convection flow of the material melt is suppressed and the temperature distribution in the crucible can be easily controlled.

Abstract: A first write encoder encodes digital data in a first, high-density format. A second write encoder encodes digital data in a second, low-density (i.e., ANSI) format. A first read decoder decodes digital data from the first format. A second read decoder decodes digital data from the second format. A disk drive receives a replaceable 90 millimeter optical disk. A read/write head reads encoded data from and writes encoded data to a 90 millimeter optical disk received by the drive. In a first mode, the first write encoder is connected between a source of digital data and the read/write head, and the first read decoder is connected between the read/write head and the utilizing apparatus. In a second mode, the second write encoder is connected between the source and the read/write head, and the second read decoder is connected between the read/write head and the utilizing apparatus.