Abstract: This optical coupler for coupling a plurality of visible light beams having different wavelengths includes: a substrate made of a material different from lithium niobate; and an optical coupling function layer formed on a main surface of the substrate. The optical coupling function layer includes: two multimode-interference-type optical coupling parts; optical-input-side waveguides and an optical-output-side waveguide connected to one multimode-interference-type optical coupling part, and optical-input-side waveguides and an optical-output-side waveguide connected to the other multimode-interference-type optical coupling part. The multimode-interference-type optical coupling parts, the optical-input-side waveguides, and the optical-output-side waveguides are made of a lithium niobate film.

Abstract: A throttle portion is defined between an upper end of a sac chamber and a conical portion of a needle to have a throttle opening area S1. Half of an area surrounded by the throttle portion, the needle, an inner wall of the sac chamber, and a lower end extended line in a cross section of the sac chamber taken along a sac center line is an injection hole upstream area S2. A lift amount, when the throttle opening area S1 is equal to an area which is calculated by multiplying an injection hole area S3 by the number of the injection holes, is a predetermined lift amount L. A viscosity coefficient of fuel is ?. An index value Sa, which is calculated in accordance with an equation as below, is set to 0.5 or greater.

Abstract: A throttle portion is defined between an upper end of a sac chamber and a conical portion of a needle to have a throttle opening area S1. Half of an area surrounded by the throttle portion, the needle, an inner wall of the sac chamber, and a lower end extended line in a cross section of the sac chamber taken along a sac center line is an injection hole upstream area S2. A lift amount, when the throttle opening area S1 is equal to an area which is calculated by multiplying an injection hole area S3 by the number of the injection holes, is a predetermined lift amount L. A viscosity coefficient of fuel is ?. An index value Sa, which is calculated in accordance with an equation as below, is set to 0.5 or greater.

Abstract: The fundus photographing apparatus of the present invention includes an illumination light source that generates illumination light flux for illuminating a fundus (of a subject eye), a scanning optical system that converts the illumination light flux from the illumination light source unit into spot light to scan the fundus in two-dimensional directions of a horizontal direction and a vertical direction by the spot light, a light receiver that receives reflected light from each portion of the fundus illuminated by the spot light, and a fundus image acquiring unit that acquires a fundus image based on a signal from the light receiver, wherein the scanning optical system is provided with a scanner including a reflection mirror plate that rotates about orthogonal two axes to simultaneously deflect the spot light in the vertical direction and the horizontal direction for scanning.

Abstract: In an injection hole of a nozzle, a maximum value of a longitudinal length of an inlet, which is measured in a direction of an inlet longitudinal axis of the inlet, is larger than a maximum value of a longitudinal length of an outlet, which is measured in a direction of an outlet longitudinal axis of the outlet. A rear end edge of an opening edge of the inlet is shaped into an arc. When the maximum value of the inlet is made larger than the maximum value of the outlet, an upstream end of the inlet can be placed at a further upstream side, so that a turn angle of a fuel flow can be reduced to increase the flow coefficient. Furthermore, when the rear end edge is shaped into the arc, the maximum value of the inlet can be increased.

Abstract: In a nozzle, in a cross section including an axis of a nozzle body, a side surface and a seat surface are both smoothly connected to an arc of a circle inscribing both the side surface and the seat surface. A part of a needle which is adjacent to a tip end side of a seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction. Thus, no corner is on the seat surface or the side surface, and the two surfaces form one curved surface. Since a cavitation generated in a sack chamber can be reduced, even when an injection quantity is significantly small such that an injection port does not throttle an injection flow, a flow coefficient of the injection flow is improved and a penetration of a spray of the fuel can be maintained.

Abstract: In an injection hole of a nozzle, a maximum value of a longitudinal length of an inlet, which is measured in a direction of an inlet longitudinal axis of the inlet, is larger than a maximum value of a longitudinal length of an outlet, which is measured in a direction of an outlet longitudinal axis of the outlet. A rear end edge of an opening edge of the inlet is shaped into an arc. When the maximum value of the inlet is made larger than the maximum value of the outlet, an upstream end of the inlet can be placed at a further upstream side, so that a turn angle of a fuel flow can be reduced to increase the flow coefficient. Furthermore, when the rear end edge is shaped into the arc, the maximum value of the inlet can be increased.

Abstract: A fuel injector has a cylindrical nozzle body, a nozzle needle, a pressure chamber and an injection passage. The injection passage includes a first hole and a second hole. A minimum vertical distance between an outer periphery of a first nozzle hole outlet and a contact point relative to an axial center line of the first hole is defined as a vertical distance R. A minimum axial distance between the first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as an axial distance L. An angle between the axial center line of the first nozzle hole and the outer periphery line of the fuel spray is defined as an injection angle ?. The vertical distance R, the axial distance L and the injection angle ? satisfy a formula: R/(L×tan ?)>6.0.

Abstract: The fundus photographing apparatus of the present invention includes an illumination light source that generates illumination light flux for illuminating a fundus (of a subject eye), a scanning optical system that converts the illumination light flux from the illumination light source unit into spot light to scan the fundus in two-dimensional directions of a horizontal direction and a vertical direction by the spot light, a light receiver that receives reflected light from each portion of the fundus illuminated by the spot light, and a fundus image acquiring unit that acquires a fundus image based on a signal from the light receiver, wherein the scanning optical system is provided with a scanner including a reflection mirror plate that rotates about orthogonal two axes to simultaneously deflect the spot light in the vertical direction and the horizontal direction for scanning.

Abstract: A fuel injector has a cylindrical nozzle body, a nozzle needle, a pressure chamber and an injection passage. The injection passage includes a first hole and a second hole. A minimum vertical distance between an outer periphery of a first nozzle hole outlet and a contact point relative to an axial center line of the first hole is defined as a vertical distance R. A minimum axial distance between the first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as an axial distance L. An angle between the axial center line of the first nozzle hole and the outer periphery line of the fuel spray is defined as an injection angle ?. The vertical distance R, the axial distance L and the injection angle ?satisfy a formula: R/(L×tan?)>6.0.

Abstract: In a nozzle, in a cross section including an axis of a nozzle body, a side surface and a seat surface are both smoothly connected to an arc of a circle inscribing both the side surface and the seat surface. A part of a needle which is adjacent to a tip end side of a seat portion is a cone having a diameter reduced toward a tip end side of the cone in the axial direction. Thus, no corner is on the seat surface or the side surface, and the two surfaces form one curved surface. Since a cavitation generated in a sack chamber can be reduced, even when an injection quantity is significantly small such that an injection port does not throttle an injection flow, a flow coefficient of the injection flow is improved and a penetration of a spray of the fuel can be maintained.

Abstract: Provided are an amphipathic compound represented by any of the following Formulas: ##STR1## (R.sub.1 is a linear or branched, saturated hydrocarbon group having 6 to 48 carbon atoms, or a linear or branched, unsaturated hydrocarbon group containing 1 to 12 unsaturated double bond and having 6 to 48 carbon atoms; Y is NH, N--(CH.sub.2 --CH.dbd.CH.sub.2), or O; Q is --CH.sub.2 --C(R.sub.2).dbd.CH.sub.2 or --R.sub.4 --O--CO--C(R.sub.2).dbd.CH.sub.2 ; and M is alkali metal, an ammonium group, or --(CH.sub.2 CH.sub.2 O).sub.m H), a copolymer of the amphipatic compound with a copolymerizable ethylenically unsaturated compound and, a paper making additive containing a water soluble or dispersible high molecular compound as an active ingredient and processes for producing these high molecular compounds.

Abstract: A process for producing refined hydrogen iodide having organic components of 0.2 ppm by volume or less and water of 0.1 ppm by volume or less by contacting crude hydrogen iodide with a zeolite is disclosed. Crude hydrogen iodide is obtained by reducing iodine with a hydrogenated naphthalene, wherein all of the iodine is dissolved in advance in a portion of the hydrogenated naphthalene to prepare an iodine solution, and the reaction is carried out while adding continuously or intermittently the iodine solution to the balance of the hydrogenated naphthalene. The same operation may be repeated in succession using unreacted hydrogenated naphthalene and fresh iodide. The zeolite is contacted in advance with crude hydrogen iodide, the amount of which is at least 1/3 (weight ratio) relative to the amount of the zeolite, to convert impurities of sulfur components contained in the zeolite to hydrogen sulfide, thereby removing the sulfur components.

Abstract: In preparing an iodoalkynyl carbamate by iodinating an alkynyl carbamate with iodine monochloride in water or a solvent mixture composed of water and an organic solvent in the presence of a base, the iodoalkynyl carbamate can be obtained in a yield of as high as 96 to 98% by using the alkynyl carbamate in a concentration of 5 to 20% by weight, dissolving the iodine monochloride in an aqueous solution of hydrochloric acid or an aqueous solution of an alkali metal chloride (the amount of iodine monochloride used being within the range of 1.0 to 1.2 moles per mole of the alkynyl carbamate and the amount of base used being within the range of 0.95 to 2.00 gram equivalents per mole of iodine monochloride), and carrying out the reaction at a temperature of 10.degree. to 40.degree. C. for a period of 1 to 4 hours.According to this process, highly pure iodoalkynyl carbamates which are useful as industrial germicides can be prepared with good selectivity and in high yield.