Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens having a negative refractive power, a fifth lens having a negative refractive power, a sixth lens, and a seventh lens having a positive refractive power. The first lens to seventh lens are sequentially disposed in a direction from an object side toward an imaging plane.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the optical imaging system satisfies 0.5<L12345TRavg/L7TR<0.9, where L12345TRavg is an average value of overall outer diameters of the first to fifth lenses, L7TR is an overall outer diameter of the seventh lens, and L12345TRavg and L7TR are expressed in a same unit of measurement.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens including a concave object side surface, a fourth lens, a fifth lens, and a sixth lens sequentially disposed from an object side toward an image side. The optical imaging system satisfies 0.7<TL/f<1.0 and F No.<2.1, where TL is a distance from an object side of the first lens to an imaging plane, f is a total focal length of the optical imaging system, and F No. is the F No. of the optical imaging system.

Abstract: The present invention relates to an alloy-coated steel sheet comprising: a steel sheet, and Al—Mg—Si—Zn alloy layer positioned on the steel sheet, wherein the Al—Mg—Si—Zn alloy layer comprises a Mg—Zn alloy phase, and wherein the Mg—Zn alloy phase comprises MgZn2 and Mg2Zn11, and the Mg—Zn alloy phase further comprises at least one of MgZn, Mg21Zn25, Mg51Zn20 and Mg2Zn3.

Abstract: Provided is a galvanized steel sheet plated by vacuum deposition and, more specifically, to a galvanized steel sheet having excellent hardness and galling resistance, and a method for manufacturing same. The zinc coated steel sheet includes: a base steel sheet; and a zinc coated layer formed on the base steel sheet. The zinc coated layer is formed of a columnar structure, and a content of Mn included in the zinc coated layer is 0.1 to 0.4 wt %.

Abstract: Provided are an alloy coating steel plate and a method of manufacturing the same, and in this case, the alloy coating steel plate includes a steel, and an Al—Mg—Si alloy layer positioned on the steel plate, wherein the Al—Mg—Si alloy layer is formed to include Mg—Si alloy grains in an alloy layer configured in an Al—Mg alloy phase.

Abstract: Provided is a multilayer zinc alloy plated steel material comprising a base steel material and multiple plating layers formed on the base steel material, wherein each of the multiple plating layers includes one of a Zn plating layer, a Mg plating layer, and a Zn—Mg alloy plating layer, and the ratio of the weight of Mg contained in the multiple plating layers to the total weight of the multiple plating layers is from 0.13 to 0.24.

Abstract: Provided is an alloy-coated steel sheet and a manufacturing method thereof. The alloy-coated steel sheet includes: a steel sheet; and an Al—Mg—Si alloy layer disposed on the steel sheet, wherein the Al—Mg—Si alloy layer has a form in which Mg—Si alloy grains are included in an alloy layer consisting of an Al—Mg alloy phase.

Abstract: The present invention relates to an alloy-coated steel sheet comprising: a steel sheet, and Al—Mg—Si—Zn alloy layer positioned on the steel sheet, wherein the Al—Mg—Si—Zn alloy layer comprises a Mg—Zn alloy phase, and wherein the Mg—Zn alloy phase comprises MgZn2 and Mg2Zn11, and the Mg—Zn alloy phase further comprises at least one of MgZn, Mg21Zn25, Mg51Zn20 and Mg2Zn3.

Abstract: Provided is a multilayer zinc alloy plated steel material comprising a base steel material and multiple plating layers formed on the base steel material, wherein each of the multiple plating layers includes one of a Zn plating layer, a Mg plating layer, and a Zn—Mg alloy plating layer, and the ratio of the weight of Mg contained in the multiple plating layers to the total weight of the multiple plating layers is from 0.13 to 0.24.

Abstract: Provided is an apparatus for controlling a coating layer in a physical vapor deposition (PVD) plating process that forms a coating layer on a steel sheet with metal vapor by PVD. The apparatus for controlling a coating layer comprises: a crucible into which a molten material is introduced; an electromagnetic induction coil disposed around the outer periphery of the crucible to heat the molten material introduced into the crucible and form a molten metal to generate metal vapor from the molten metal; a power supply unit for supplying an electric current to the electromagnetic induction coil; and a control unit for measuring the impedance of the electromagnetic induction coil and controlling the electric current supplied to the electromagnetic induction coil so that the impedance is kept constant according to the molten material which is introduced into the crucible at a constant feed rate.

Abstract: Provided is a galvanized steel sheet plated by vacuum deposition and, more specifically, to a galvanized steel sheet having excellent hardness and galling resistance, and a method for manufacturing same. The zinc coated steel sheet includes: a base steel sheet; and a zinc coated layer formed on the base steel sheet. The zinc coated layer is formed of a columnar structure, and a content of Mn included in the zinc coated layer is 0.1 to 0.4 wt %.

Abstract: Provided is a multilayer zinc alloy plated steel material comprising a base steel material and multiple plating layers formed on the base steel material, wherein each of the multiple plating layers includes one of a Zn plating layer, a Mg plating layer, and a Zn—Mg alloy plating layer, and the ratio of the weight of Mg contained in the multiple plating layers to the total weight of the multiple plating layers is from 0.13 to 0.24.

Abstract: Provided are an alloy coating steel plate and a method of manufacturing the same, and in this case, the alloy coating steel plate includes a steel, and an Al—Mg—Si alloy layer positioned on the steel plate, wherein the Al—Mg—Si alloy layer is formed to include Mg—Si alloy grains in an alloy layer configured in an Al—Mg alloy phase.

Abstract: Provided is a plated steel sheet often used as materials for vehicles, home appliances, construction and the like and, more specifically, to a plated steel sheet having a multilayer structure and a method for manufacturing the same.

Abstract: Provided is an apparatus and a method that is capable of performing continuous coating at a constant coating composition and rate. One embodiment is a deposition apparatus for coating two or more compounds or elements on a substrate, the apparatus comprising: a supply unit for supplying the two or more compounds or elements to a plurality of solid bodies; a heating unit for melting and evaporating the solid bodies supplied from the supply unit to form vapor; a buffer unit, connected to the heating unit, in which the vapor stays and is mixed with previously generated vapor; and a nozzle connected to the buffer unit and having an opening toward the substrate.

Abstract: Provided is an alloy-coated steel sheet and a manufacturing method thereof. The alloy-coated steel sheet includes: a steel sheet; and an Al—Mg—Si alloy layer disposed on the steel sheet, wherein the Al—Mg—Si alloy layer has a form in which Mg—Si alloy grains are included in an alloy layer consisting of an Al—Mg alloy phase.

Abstract: Provided is an alloy coating steel plate including: a steel plate; a plating layer including Al positioned on one surface or opposite surfaces of the steel plate; and a coating layer positioned on the plating layer. The coating layer is divided into two or three layers. The coating layer includes a phase of one of Al, Si, and Mg or an alloy phase including two or more thereof.

Abstract: Provided is a plated steel sheet often used as materials for vehicles, home appliances, construction and the like and, more specifically, to a plated steel sheet having a multilayer structure and a method for manufacturing the same.

Abstract: Provided is a multilayer zinc alloy plated steel material comprising a base steel material and multiple plating layers formed on the base steel material, wherein each of the multiple plating layers includes one of a Zn plating layer, a Mg plating layer, and a Zn—Mg alloy plating layer, and the ratio of the weight of Mg contained in the multiple plating layers to the total weight of the multiple plating layers is from 0.13 to 0.24.