Abstract: Disclosed herein are a polyiscoyanate comprising a mixture of aromatic polyisocyanates represented by the general formula: ##STR1## wherein A is a phenylene group, alkylene group, alkyl-substituted phenylene group, diphenylene group, diphenyl ether group or naphthylenyl group, R.sub.1 is a halogen atom, lower alkoxy group with a carbon number of 4 or less or lower alkyl group with a carbon number of 5 or less, R.sub.1 s may be the same or different from each other and may form a ring, l is 1 or 2, m is an integer of 0-3, and n is a integer of 0-300, and a production process thereof.

Abstract: The present invention relates to a process for preparing a hard transparent resin comprising polymerizing a monomer (A) having both a functional group of the following formula (I): ##STR1## wherein X is selected from the group consisting of an oxygen atom and a sulfur atom,and a functional group selected from the group consisting of a functional group of the formula (II):CH.sub.2 CR--COO-- (II)wherein R is selected from the group consisting of hydrogen and methyl group,and a functional group of the formula (III): ##STR2## The invention also provides a process for preparing a transparent resin comprising copolymerizing monomer (A) with a monomer (B) having at least one functional group selected from the group consisting ofCH.sub.2 CH.dbd.COO--,CH.sub.2 .dbd.C(CH.sub.3)--COO--, and ##STR3## This resin can be suitably used as a glazing material, and in the manufacture of optical lenses, optical information recording medium substrates, etc.

Abstract: The present invention relates to a transparent resin which has a high surface hardness and which is excellent in scratch resistance, heat resistance and chemical resistance, a glazing material, a protective cover for display devices, an optical lens and a hard coat material comprising the above-mentioned resin, and a novel polymerizable monomer represented by the formula (I) useful as a raw material for the high surface hardness transparent resin. ##STR1## wherein R is an aliphatic residue having or not having an oxygen atom, an alicyclic ring, a heterocyclic ring or an aromatic ring, or an alicyclic residue, l is 0 or 1, each of i and j is an integer of 1 or more, and when l=0, i=j=1, when l=1, (i+j) is 4 or less, when j=1, X is oxygen or sulfur, when j.gtoreq.2, all X's are oxygen or sulfur, or one X is oxygen and the other X's are sulfur, or one X is sulfur and the other X's are oxygen.

Abstract: Herein disclosed are an .alpha.-(aminocyclohexyl)alkylamine represented by the following general formula (II): ##STR1## wherein R represents hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, provided that the amino group bonded to the cyclohexyl group may be in either of the 2-, 3- and 4-positions and a method for preparing it; an .alpha.-(isocyanatocyclohexyl)alkylisocyanate of Formula (II) wherein the amino groups are replaced with isocyanato groups and a method for preparing it; polyisocyanato-isocyanurate represented by the following general formula (IV): ##STR2## wherein R.sub.1, R.sub.2 and R.sub.

Abstract: There are here provided a low-hygroscopic sulfur-containing and crosslinked structure-having urethane resin, urethane resin plate and shape-recoverable molding article which is prepared by first selecting a polyisocyanate compound having m (which is an integer of 2 or more) isocyanate groups in one molecule and a polythiol compound having n (which is an integer of 2 or more) thiol groups in one molecule so that the total number of m+n may be 5 or more, and then polymerizing the composition of the polyisocyanate compound and the polythiol compound; a low-hygroscopic sulfur-containing urethane coating material which comprises the above composition; and a low-hygroscopic sulfur-containing urethane adhesive which comprises the composition. In the resin of the present invention, its water absorption is as low as a level of 0.02 to 0.20% by weight, and its adhesion to a hard coating film is also good.

Abstract: The present invention relates to a process for producing a plastic lens having a high refractive index and profile regularity comprising forming a mixture of one or more of sulfur-containing aromatic polyisocyanate compounds, one or more of active hydrogen compounds selected from the group consisting of polyol compounds and polythiol compounds, and at least one internal mold releasing agent, and subjecting the resulting mixture to casting polymerization, and a plastic lens obtained according to the process.

Abstract: Herein disclosed are a polyisocyanato-isocyanurate represented by the following formula (I): ##STR1## wherein n is an integer ranging 1 to 5 and R.sub.1, R.sub.2 and R.sub.3 may be the same or different and each represents hydrogen atom or a lower alkyl group and a method for preparing it; and a resin containing an organic polyisocyanate containing not lower than 10% by weight of the polyisocyanato-isocyanurate represented by Formula (I) and a compound having at least two active hydrogen atoms as well as a resin composition for coating materials which comprises the resin.

Abstract: An endoscope apparatus is disclosed in which the horizontal transfer of the charge of a solid imaging device such as a CCD and the resetting for the detection of the charge are conducted by a common drive signal. The signal transmitted from the solid imaging device is caused to contain a feed-through period by making the drive signal to be served by a multi-valued level horizontal transfer signal exceeding a trinary value. Therefore, reset noise or the like can be eliminated by processing the output signal by using a correlated double sampling circuit or the like so that a video signal exhibiting a good S/N ratio can be obtained.

Abstract: The present invention relates to a process for preparing a hard transparent resin comprising polymerizing a monomer (A) having both a functional group of the following formula (I): ##STR1## wherein X is selected from the group consisting of an oxygen atom and a sulfur atom,and a functional group selected from the group consisting of a functional group of the formula (II):CH.sub.2 CR--COO-- (II)wherein R is selected from the group consisting of hydrogen and methyl group,and a functional group of the formula (III): ##STR2## The invention also provides a process for preparing a transparent resin comprising copolymerizing monomer (A) with a monomer (B) having at least one functional group selected from the group consisting ofCH.sub.2 .dbd.CHCOO--,CH.sub.2 .dbd.C(CH.sub.3)--COO--, and ##STR3## This resin can be suitably used as a glazing material, and in the manufacture of optical lenses, optical information recording medium substrates, etc.

Abstract: Herein disclosed are a polyisocyanato-isocyanurate represented by the following formula (I): ##STR1## wherein n is an integer ranging 1 to 5 and R.sub.1, R.sub.2 and R.sub.3, may be the same or different and each represents hydrogen atom or a lower alkyl group and a method for preparing it; and a resin containing an organic polyisocyanate containing not lower than 10% by weight of the polyisocyanato-isocyanurate represented by Formula (I) and a compound having at least two active hydrogen atoms as well as a resin composition for coating materials which comprises the resin.

Abstract: The present invention relates to a mercapto compound, a process for preparing the mercapto compound, a process for preparing a polythiourethane base resin containing the mercapto compound, and a process for preparing plastic lenses containing the resin.

Abstract: The present invention relates to a high surface hardness transparent resin having excellent scratch resistance, heat resistance and chemical resistance, a glazing material, a protective cover for display devices, an optical lens and a hard coat material comprising the aforesaid resin, and a novel polymerizable monomer which is useful as a raw material of the above-mentioned resin.The monomer is represented by the formula (I) ##STR1## (wherein R is an aliphatic residue having or not having an halogen atom, an oxygen atom, an alicyclic ring, a heterocyclic ring or an aromatic ring, an alicyclic residue, or a heterocyclic residue, n is an integer of 1 to 4, when n=1, X is oxygen or sulfur, when n.gtoreq.2, X's are all oxygen or all sulfur, one X is oxygen while the other X or X's are sulfur, one X is sulfur while the other X or X's are oxygen, or two X's are oxygen while the other X's are sulfur).

Abstract: A resin for urethane lenses is here disclosed which is obtained by reacting an alicyclic isocyanate compound represented by the formula (I) ##STR1## and/or an alicyclic isocyanate compound represented by the formula (II) ##STR2## with at least one active hydrogen compound selected from the group consisting of polyol compounds, polythiol compounds except 1,2-bis[(2-mercaptoethyl)thio]-3-mercaptopropane, and thiol compounds having a hydroxyl group. In addition, lenses comprising this resin and processes for the preparation of the resin and the lenses are also disclosed herein.

Abstract: The present invention relates to resin useful in preparing plastic lenses having a high refractive index comprising reacting an aliphatic polyisocyanate compounds having at least one sulfur atom with one or more of active hydrogen compounds selected from the group consisting of a polyol, a polythiol having sulfur atoms only in a mercapto groups, and a polythiol having at least one sulfur atom other than in the mercapto groups; lenses containing the above-mentioned resin; and a method for the preparation thereof characterized by adding an internal release agent to the mixture of the above-mentioned raw materials in casting lenses from the resin; and lenses obtained by this method.

Abstract: A process for producing a plastic lens having a high refractive index and profile regularity which includes forming a mixture of one or more of sulfur-containing aromatic polyisocyanate compounds, one or more of active hydrogen compounds selected from the group consisting of polyol compounds and polythiol compounds, and at least one internal mold releasing agent. Then subjecting the resulting mixture to casting polymerization, to form the plastic lens.

Abstract: Polyfunctional monomers are disclosed that yield transparent resins having high transparency and excellent surface hardness and heat resistance. The present polyfunctional monomers are represented by the general formula (I): ##STR1## wherein R represents a group having a carbamido group or an oxazolidone group that will be bonded to the dimethylbenzyl group of the formula (I) and an acryl group or methacryl group at the other end. Control of the polymerization of the polyfunctional monomers is easy, and polymerization of the polyfunctional monomers yield and resins having excellent surface hardness, heat resistance, and workability, and having high transparency. The resins are well adapted for use as glazing materials, optical lenses, and optical disc substrates.

Abstract: A charge detection circuit is capable of converting electrostatic charge quantities on a solid-state imaging chip into voltage signals of negative polarity. The voltage signals of the negative polarity are suppled to a DC-coupled polarity inversion circuit which inverts the polarity of the signals and amplifies the signals. In consequence, the generation of heat in the transistor of the outpout stage is reduced so as to suppress undesirable temperature rise of the solid-state imaging chip.

Abstract: An endoscope automatic light control apparatus comprises an automatic light control apparatus for controlling the quantity of light incident to an imaging apparatus for imaging an endoscopic image so as to maintain a signal from the imaging apparatus substantially at a constant level. An automatic gaim control apparatus inputs a signal from the imaging apparatus and controls its output level so as to maintain the signal substantially at a constant level. The automatic light control apparatus and the automatic gain control apparatus respectively having a plurality of brightness information generating apparatuses generating brightness information based on the signal from the imaging apparatus. The plurality of brightness information generating apparatuses are different from each other in a method of generating brightness information and one of the plurality of brightness information generating apparatuses able to be selected.

Abstract: An electronic endoscope apparatus whereby the position of the tip part of an insertable part inserted into a body cavity is confirmed from outside the body with the transmission out of the body from within the body cavity of a light emitted from an illuminating window provided in the tip part.

Abstract: An endoscope system has a signal processing circuit for converting an image signal output of a solid state imaging device into a standard image signal, a monitor for providing a display of the standard image signal, an automatic gain control circuit for outputting an image signal whose level is automatically adjusted in accordance with the level of the image signal; and a gain variation region setting circuit for outputting a control signal to set the gain variation region of the automatic gain control circuit. With this arrangement, it is possible to properly set the AGC variation region of the AGC of the signal processing apparatus in accordance with such factors as the number of pixels of the solid state imaging device which constitutes a part of an electronic endoscope connected.