Abstract: An optical measurement system for eliminating the influences of time variations on light sources, transmission lines, photo detectors, etc. The system includes light sources which generate two pulse-shaped optical signals of different light wavelengths with a portion of the optical signals being transmitted to a measuring part in a distant place by a transmission line. In the measuring part, a change of a measured object is converted into a variation in the quantity of transmission of light, and the optical signal subjected to the variation is transmitted to a signal processing portion by a transmission line. The varied optical signal is converted into a first electric signal by a photo detector. Another portion of the optical signals from the light sources is converted into a second electric signal by another photo detector.

Abstract: A laser-to-fiber coupler is constructed by an optical waveguide arranged between a semiconductor laser and a transmitting optical fiber through which an optical beam emanating from the laser is transmitted in order to reduce the amount of a reflection beam from the optical fiber, which is injected into the active layer of the semiconductor laser.The waveguide is made by an optical fiber of which at least one of core radius or numerical aperture (N.A.) is smaller than those of the transmitting optical fiber.

Abstract: An apparatus for measuring water in cow's milk. Sample milk is heated and dryed by microwaves in an oven made of a microwave waveguide. Weights of the sample before and after the drying of the sample are measured by an automatic balance. Weight signals obtained from the balance are memorized in a memory circuit to calculate the solid material ratio or water ratio of the sample milk. A water dummy is employed for stabilizing oven temperature. Support means for one or more additional sample plates may be arranged in the waveguide for preliminary drying of one or more filter paper in the additional sample plate to shorten the subsequent heating time of the sample milk.

Abstract: A frame selectively supports sheet cassettes of various widths, one edge of the selected cassette being aligned against a first side wall of the frame. A first feed roller is operatively disposed above the selected cassette and spaced by a predetermined distance from the first side wall. For a maximum size cassette, the opposite edge of the cassette is aligned with a second side wall of the frame. A second feed roller is axially movable and embraced by a roller carrier which is biased into engagement with the second side wall so that the second feed roller is spaced from the second side wall by the same predetermined distance to ensure symmetrical sheet feed. A stop member integral with the roller carrier abuttingly prevents narrower cassettes from being inserted into the frame. To utilize a narrower cassette, an insert is mounted on the frame so that the edges of the cassette engage with the first side wall of the frame and with the insert respectively.

Abstract: The electrophotographic copying machines are of the type in which a photosensitive drum is removable from the machine, for inspection or other purposes, through an opening formed in a sidewall, which opening is normally covered by a coverplate. Plural cleaning devices which are normally maintained in pressing engagement with the peripheral drum surface, are automatically released from such engagement once the coverplate has been dismounted from the sidewall and also returned to the original position as the coverplate is remounted, thereby preventing damage of the drum as well as a wrong usage of the machine which may be caused by inadvertently failing to reset each cleaning device.

Abstract: In an optical fiber connector, the pair of optical fibers to be connected together are placed end-to-end in a linear groove which has been formed on a lateral surface of a central cylinder. They are held fixed by a holding member which is fitted in the groove and is moved towards the optical fibers according to the rotation of a hollow cylinder which externally touches the central cylinder, whereby the optical fibers can be connected with a precise alignment and accordingly with a low optical power loss.

Abstract: An improvement in a process for producing 2-methylthiazole or 2,4-dimethylthiazole by reacting diethylamine, ethylidene-ethylamine or diisopropylamine with sulfur, the improvement comprising conducting said reaction in a reactor wherein a carbon layer has been formed on the inner surface of the walls of said reactor.

Abstract: An optical wave guide comprises a cylindrical body which is made of a first transparent dielectric, and a second transparent dielectric which is concentrically formed on the outer periphery of the cylindrical body and which has an index of refraction lower than that of the first dielectric, the central part of the wave guide being hollow.