Abstract: An optical information recording and reproduction apparatus that correctly performs tracking control even when there is a step in the information recording surface in an apparatus that records and reproduces information to and from an information recording medium such as an optical card or the like. An optical information recording and reproduction apparatus which focusses a light spot from a laser onto an optical information recording medium which has a tracking track and performs the recording and reproduction of information to required positions using the tracking track as a reference. The apparatus reduces the optical output of the laser when track jumping and seeking when there is an information reproduction operation.

Abstract: A linear motor having a magnetic circuit and a moving coil, the magnetic circuit comprising a linear yoke provided at the center of the circuit and a pair of linear magnets, the linear yoke and the pair of linear magnets forming a pair of linear gaps with the linear yoke interposed therebetween, the magnetic circuit applying a magnetic field to the linear gaps, the movable coil mounted on the linear yoke of the magnetic circuit being moved along the linear yoke by an electromagnetic action to the magnetic circuit when the movable coil is powered, wherein the linear magnet has a larger magnetic force at opposite end portions in the longitudinal direction of the linear magnet than at an intermediate area, the magnetic reluctance of the magnetic circuit is made large to obtain a driving current of the movable coil corresponding to the magnetic reluctance when the moving coil moves at the intermediate area of the linear magnet, or the magnetic circuit is mounted on a plate made of material having the same magneti

Abstract: There is disclosed a heat treating oil composition which comprises (A) at least one base oil selected from a mineral oil and a synthetic oil each having a sulfur content of not more than 300 ppm and (B) at least one member selected from alkaline earth metal salts of salicylic acid. There is also disclosed a heat treating oil composition which comprises (I) a base oil having a sulfur content of 3 to 1000 ppm consisting of said (A) component and (C) at lease one member selected from a sulfur and a sulfur compound, along with (II) various additives for quenching.This heat treating oil composition is suitable for quenching under the condition of a high oil temperature and capable of obtaining a treated metal excellent in brightness and having a minimized distortion.

Abstract: An optical head for reading and/or writing information from and in an optical recording medium having an improved sensor structure for focusing and tracking error detections. A light beam is separated into a 0th-order diffraction light beam and .+-.1st-order diffraction light beams, and these light beams are impinged upon a recording track of the optical recording medium. The light beams reflected from the optical recording medium is separated into two different directions, and the tracking and focusing error detections are carried out with multi-segment optical sensors which are connected in a complementary manner. As a result, the influence of the tracking error on the focusing error detection is eliminated, and the linearity of the focusing error detection is improved.

Abstract: A toxic substance-detecting device detects toxic substances in water by use of a microorganism sensor to ascertain the safety of affluents flowing into sewage-treating processes, environmental waters such as rivers, and waters flowing into water purification plants and a water quality-monitoring system employing a detecting device. The device includes a fixed micro-organism membrane and apparatus for circulating a buffer solution of micro-organism substrate and nutrient to one side of the membranne and solutions of water to be examined, standard and cleaning water to the other side.

Abstract: This device is an arrangement for detecting a signal for effecting a focus control of an optical head with respect to an optical information recording medium by making use of a reflected light beam from the optical information recording medium. On an optical path for a reflected light beam reflected from the recording surface of the optical recording medium, a photodetector is provided. This photodetector is composed of a plurality of elements arranged symmetrically in the transverse cross section of the light beam. Thus, an output of the outside element and an output of the inside element of the plural elements arranged in the transverse cross section of the light beam are used to detect a focus error, thus to utilize the signal detected for the focus control.

Abstract: An engine of a motorcycle is provided with a lubricating apparatus and a crank case within which is mounted a crank shaft having one end extending outwardly from a side wall of the crank case, and a cam sprocket drive gear is mounted upon the crank shaft. A cam chain chamber within which a chain is disposed in a loop is formed upon one side of a cylinder block including a cylinder and a piston and a cylinder head disposed above the cam sprocket drive gear. An oil passage hole is formed within a mating face of the crank case to be mated with the side cover, and an oil passage tube is inserted into the oil passage hole.

Abstract: The present invention relates to an optical head for recording and playing back optical information, the optical head comprising an illumination system which shines three beams of light comprising 0-dimensional diffraction light, +1-dimensional diffraction light, and -1-dimensional diffraction light onto an optical information recording medium, and a photoreceiver system which receives three beams of reflected light from the recording medium; the photoreceiver system being provided with an edge mirror whereby, of the three beams of reflected light from the recording medium, approximately one half of the 0-dimensional diffraction light and all of the +1-dimensional diffraction light is received by a first photoreceiver diode, without being affected by the edge mirror, and the remaining approximately one half of the 0-dimensional diffraction light and all of the -1-dimensional diffraction light is reflected by the edge mirror and is received by a second photoreceiver diode; wherein a focusing control signal, a

Abstract: This device is an arrangement for detecting a signal for effecting a focus control of an optical head with respect to an optical information recording medium by making use of a reflected light beam from the optical information recording medium. On an optical path for a reflected light beam reflected from the recording surface of the optical recording medium, a photodetector is provided. This photodetector is composed of a plurality of elements arranged symmetrically in the transverse cross section of the light beam. Thus, an output of the outside element and an output of the inside element of the plural elements arranged in the transverse cross section of the light beam are used to detect a focus error, thus to utilize the signal detected for the focus control.

Abstract: A fluidized-bed type activated-sludge treatment of sewage or industrial waste water characterized in that a fine powder of a granulated blast furnace slag is added to an aeration tank of the activated-sludge treatment installation to facilitate the treatment. In a fixed-bed type activated-sludge treatment of the sewage or industrial waste water, the granulated blast furnace constitutes the main constituent element of a ceramic material to be mounted in the aeration tank so as to serve as a fixing carrier for the activated sludge.

Abstract: A bringing-up apparatus is disposed in a channel having a fresh water inlet and outlet and provides in the channel areas of repose for yolk sac fry released to the channel. The bringing-up apparatus includes a plurality of groyne plates disposed in the channel such that they extend in a direction crossing the water flow in the channel and are spaced apart in the direction of the water flow for providing places of gentle water flow in the channel and also includes at least one support disposed on the bottom of the channel for supporting the groyne plates such that a space is maintained between adjacent groyne plates.