Abstract: A disc recording and/or reproducing apparatus provided with disc exchange function to carry out recording/reproduction while carrying out exchange between plural discs held within a disc holding body. This recording and, or reproducing apparatus comprises a disc holding body within which plural discs are held at predetermined intervals (spacings) in a stacked state, a biasing member for biasing respective discs held within the disc holding body in a direction projected from the disc holding body, a recording/reproduction unit for carrying out recording and/or reproduction of information signals with respect to the optical disc drawn out, and a carrying mechanism for taking out a predetermined one disc from the disc holding body to carry it to the recording/reproduction unit.

Abstract: A driving apparatus using a motor has a stepping motor, a moving mechanism, and a driving circuit. The moving mechanism moves an object to be driven on the basis of a driving force of the stepping motor. The moving mechanism moves the object among a plurality of moving points set on the basis of even-number steps of the stepping motor. The driving circuit supplies a plurality of drive signals equal to a plurality of even-number steps to the stepping motor.

Abstract: A disc recording and/or reproducing apparatus provided with disc exchange function to carry out recording/reproduction while carrying out exchange between plural discs held within a disc holding body includes a disc holding body within which plural discs are held at predetermined intervals (spacings) in a stacked state, a biasing member for biasing respective discs held within the disc holding body in a direction projected from the disc holding body, a recording/reproduction unit for carrying out recording and/or reproduction of information signals with respect to the optical disc drawn out, and a carrying mechanism for taking out a predetermined one disc from the disc holding body to carry it to the recording/reproduction unit.

Abstract: Extendable bit teeth are supported by the guide grooves formed on the end face at the point of a bit body in such a manner as to be slidable. The extendable bit teeth slide along the guide grooves in an excavating direction to thereby project from the end face at the point of the bit body. The extendable bit teeth slide in an opposite direction to the excavating direction to project from the outer periphery of the point of the bit body. Since the extendable bit teeth are pressed against the ground during excavation, the extendable bit teeth projects from the outer periphery of the point of the bit body so that the bit gauge can be extended, and most of the excavation hole is excavated by the bit body.

Abstract: In an apparatus for detecting amounts of relative motion of a picture expressed by a digital video signal, between successive fields of the signal, a fixed set of picture element positions are designated as respective representative points in each field of the video signal. For each representative point, the signal level value for that point during a preceding field is compared with each of a successive of picture element values in the current field, within a corresponding comparison interval which extends prior to and subsequent to the position of that representative point in the field.

Abstract: A video signal processing circuit of a single chip color camera including a color separation filter for performing a color separation on incident light passing therethrough so as to output color separated light, a solid state pickup device for picking up the color separated light passed through the color separation filter and outputting a video signal, main circuit means for generating a first luminance signal, a second luminance signal, a first color difference signal, and a second color difference signal from the video signal, compensating signal generating means for obtaining a compensation signal from the first and second color difference signals, operational means for applying the compensation signal to the first luminance signal to produce as output luminance signal, and color temperature detection means for detecting a color temperature of the incident light and outputting a DC control voltage so as to determine the compensation signal.

Abstract: An air-pressure impact type drilling method and an apparatus for the same in which a piston of an air hammer drill is moved up and down by pressure air to produce impact energy and the impact energy of the piston is used to give impact vibrations repetitively to a drill bit. In the air-pressure impact type drilling method and the apparatus for the same, the air hammer drill is operated by the pressure air to be supplied from the ground, the air that has already been used for operation of the air hammer drill is exhausted onto the ground through an air exhaust pipe provided in a drilling pipe and communicating with an air exhaust passage formed in the air hammer drill, and substances cut out by the air hammer drill together with muddy water within the trench are discharged by means of a reverse circulation system while drilling on through the earth.

Abstract: An optical waveguide path and an optical branch path branching from the waveguide path are formed in an optical material which is variable in refractive index with the variation of temperature. A heat generator is provided in the vicinity of the branching portion of the waveguide path. The heat of the generator produces in the optical material a temperature gradient in a direction parallel with a plane including the waveguide path and the branch path. The temperature gradient gives the optical material a temperature gradient, by which a light beam propagating through the waveguide path is deflected for switching.

Abstract: An optical coupling device is prepared with use of an optical medium containing a monomer which is polymerizable when irradiated with light to give a polymer having a higher refractive index than the monomer. The two elements to be coupled optically are at least partly embedded in the optical medium, and an optical coupling path partly interconnecting the two elements is formed by the photopolymerization of the monomer which is accelerated by light propagating from at least one of the elements toward the other element. Thus the photopolymerization of the monomer forms in the portion of the optical coupling path a polymer which has a higher refractive index than the surrounding portion and which therefore provides an optical waveguide of the step index type.