PURPOSE:To simplify the designing, control and assembling as a whole and to reduce the cost of an optical disk reproducer by supplying the polarity inverting signal of tracking error to the driving part of a tracking servo system after deciding the presence or absence of a pit. CONSTITUTION:Two signals obtained by synthesizing four outputs given from a photodetector 21 for each left-right componen...

PURPOSE:To attain the satisfactory tracking servo by giving limitation to the output amplitude given from a detector which produces a phase difference component signal by means of the timing using between the phase difference component signals and then stabilizing, sampling and synthesizing said output amplitude to produce a tracking error signal. CONSTITUTION:Four outputs given from a 4-split pho...

PURPOSE:To obtain a tracking error of high quality with a 1-beam type optical pickup device by limiting the output opening diameter of the beam smaller than the reflected light receiving opening diameter. CONSTITUTION:The light emitted from a laser 21 passes through an aperture 22 to limit the output opening diameter of the light beam substantially smaller than the reflected light opening diameter...

PURPOSE:To obtain only an inherent tracking error signal for a tracking control system using a time difference system by eliminating the time difference of an edge part if it exceeds a fixed range needed for a normal operation. CONSTITUTION:The pulse width of the adverse phase output of a monostable multivibrator M1 and the delay time of a delay circuit Di are set at the maximum value respectively...

PURPOSE:To detect accurately the position of a disk where a dropout is produced by lowering the open loop gain of a tracking control system and at the same time increasing the detection sensitivity after estimating the position where the dropout of the disk is produced. CONSTITUTION:When the first dropout is detected under reproduction, a level comparator 26 inverts the level of an output terminal...

PURPOSE:To obtain a tracking error signal having especially high quality by providing the 2nd photodetector having an aperture diameter substantially smaller than the receiving aperture diameter of reflected light and having a photosensitive surface set at the side of an objective lens between a beam splitter and said objective lens. CONSTITUTION:The 2nd photodetector 26 having an aperture diamete...

PURPOSE:To prevent a spot from being moved to another bit train by the influence of noise, external impact, or the like, by extending practically a control area of a tracking error control signal to an optional bit train. CONSTITUTION:When the spot is moved to the outside of a line l2 in the figure, a phase comparator 20 outputs a phase difference signal D because the outside of the line l2 is the...

PURPOSE:To reuse a memory system, by using a part of a correcting bit memory as an alternative memory when a fixed trouble of one bit or plural bits occurs in the memory system with a correction code. CONSTITUTION:In the normal operation, the number of correcting bits which corresponds to a data bit length is provided as shown in Fig. (a) to detect and correct a one-bit error and detect a two-bit ...

Method and apparatus for treating raw water by introducing the raw water and a flocculating agent into a cylindrical container, preferably in a tangential manner of flow between the cylindrical container wall and a baffle spaced radially inward from the container wall, flowing the fluid radially inward towards the center of the container to a central conduit extending axially upward in the contain...

PURPOSE:To load one of Cu, V, A and Ni or Ni alloy, Au-Ge-Sb alloy and one of Au, Ag and Pt layers and arrange firmly onto a floor. CONSTITUTION:One selected from Cu, V, Al, Ti, Cr, Mo and Ni-Cr alloy is deposited to a contact surface of Si basic plate by vacuum evaporation and Ni or Ni alloy layer, Au-Ge-Sb layer and one of Au, Ag and pt are loaded. Next it is divided into chips and soldered to a...

A versatile polymeric support system for the synthesis of oligonucleotides featuring a universal primer which allows chain elongation, in either the 3' or 5' direction, with any currently available DNA or RNA synthesis method, by a process which utilizes oxidatively cleaved primers to facilitate chain elongation and release. The support system is capable of withstanding mildly basic and acidic rea...

Photochemical process for preparing N-demethyl-derivatives of nogalamycin.

(A) Novel antigen derivs. (I) consist of an antigen to which at least one muramyl peptide is covalently bonded, opt. via a bridging gp. Prefd. cpds. are of formula (Ia): A-[(Z)m-MP]n (Ia) (A is an antigen residue; Z is a bridging gp.; MP is a muramyl peptide residue; m = 0 or 1; n \-1). The muramyl peptides are pref. of formula (III) (or the corresp. oligomers). (X is CO, COO or SO2; R1 is H, alky...

Derivatives of oleandomycin, its 11-monoalkanoyl, 2-monoalkanoyl and 11,2'-dialkanoyl esters having at the 4''-position an amino group substituted with -C(=O)-C(=O)-R3 or -C(=S)-C(=O)-R3 wherein R3 is alkyl having from one to four carbon atoms, phenyl, substituted phenyl, or a heterocyclyl group, their preparation and use as antibacterial agents is described.

Catalyst for dealkylating, in the presence of steam, a hydrocarbon charge, obtained for example from a catalytic reforming unit or from a unit for the production of aromatic hydrocarbons, and containing at least one alkylaromatic hydrocarbon such as toluene or a xylene, said catalyst containing an alumina carrier of a specific surface higher than 50 m2/g and, by weight with respect to the catalyst...

In the treatment of a hydrocarbon-containing material at temperatures of 500 DEG C or above in apparatus made of a nickel-containing heat-resistant steel, the surfaces of the apparatus that are exposed to the hydrocarbon-containing material are coated with nickel-free materials consisting of metals selected from titanium, cobalt, chromium, iron or alloys thereof (optionally containing aluminium or...

PURPOSE:To join plastic pipes within a short period readily and tightly that will be used for heating or supplying hot water, by heating one end of the plastic pipe, enlarging the end, cooling the end so that the end is formed into a heat- shrinkable end, then inserting one end of the other plastic pipe into said heat- shrinkable end and heating said heat-shrinkable end to be shrunk. CONSTITUTION:...

PURPOSE:To attach firmly a holder which will be used for holding for example a chemical liquid conduit to a pipe such as an air pipe of a drug sprinkler, by inserting a head part of a holder having a holder section, the head part being a sphere in shape with the diametrically opposite sides headed, into a hole of a pipe that just has been blow molded, rotating the head part followed by cooling the...

PURPOSE:To obtain olefins from hydrocarbons in high yield, by preparing a steam-containing high-temperature gas by the use of hydrocarbons, using the gas as a heat source, feeding methane and hydrogen to the gas, decomposing thermally hydrocarbons in their presence. CONSTITUTION:Hydrocarbons are burned in the presence of steam to give a high-temperature gas containing 1,500-3,000 deg.C steam. Meth...