Abstract: This steel plate has a predetermined composition in which the proportion of ferrite and bainite in total is 10 to 60%, the proportion of martensite and tempered martensite in total is 40 to 90%, the proportion of pearlite and retained austenite in total is 0 to 10%, the ratio of the number of crystal grains of the ferrite and the bainite having an area of 3 ?m2 or less to the total number of crystal grains of the ferrite and the bainite is 40% or more, a proportion of crystal grains of the ferrite and the bainite having an area of 30 ?m2 or more is 5% or less, and a difference ?Mn between an Mn concentration at a position of 1.0 ?m from an interface of the ferrite and the martensite in a direction perpendicular to the interface inward into the ferrite grains and a maximum Mn concentration in a region up to 0.5 ?m from the interface is 1.00 mass % or less.

Abstract: Provided is a frame member formed by cold-pressing a steel sheet. The frame member has a closed cross section portion in which a cross section perpendicular to a longitudinal direction is a closed cross section, and the closed cross section portion has at least one flat part having a radius of curvature larger than a maximum external dimension of the cross section. A Vickers hardness of a thickness middle portion in a reference flat part is 300 Hv or greater, a width of the reference flat part is 2.0 times or less the effective width, and a standard deviation ratio obtained by dividing a standard deviation of hardness frequency distribution in a surface layer portion in the reference flat part by a standard deviation of hardness frequency distribution in the thickness middle portion in the reference flat part is greater than 1.0.

Abstract: A steel sheet excellent in energy absorption at the time of crushing deformation, that is, steel sheet having a predetermined chemical composition and steel microstructure which has on the sheet surface a plurality of step differences having height differences of more than 5.0 ?m at intervals of 2.0 mm or less.

Abstract: Provided are: a steel sheet having a high strength and excellent hydrogen embrittlement resistance; and a method of producing the same. The steel sheet has prescribed chemical composition and structure, in which a standard deviation ? of Mn concentration satisfies ??0.15 Mnave (wherein, Mnave represents an average Mn concentration) and a region with a Mn concentration of higher than (Mnave+1.3?) has a circle-equivalent diameter of less than 10.0 ?m. The method of producing the steel sheet includes: the hot rolling step that includes finish rolling a slab having a prescribed chemical composition under prescribed conditions; the step of coiling the thus obtained hot-rolled steel sheet at a coiling temperature of 450 to 700° C.; and the step of cold rolling the hot-rolled steel sheet and subsequently annealing this steel sheet at 800 to 900° C.

Abstract: An imaging device includes a light source unit located so as to be inclined with respect to a medium conveying surface or a medium placing surface. The light source unit includes a light emitting element, a light guide provided with the light emitting element on a first end surface side, to guide light emitted from the light emitting element in a predetermined direction, and emit the light toward the medium from an emitting surface extending in the predetermined direction, and a reflector located around the light guide other than the emitting surface. The light guide includes a light diffusing surface on an opposite side to the emitting surface. The reflector does not cover a second end surface opposite to the first end surface of the light guide. A medium side surface of the reflector is located so as to protrude from the second end surface of the light guide.

Abstract: An imaging device includes a light source unit located so as to be inclined with respect to a medium conveying surface or a medium placing surface. The light source unit includes a light emitting element, a light guide provided with the light emitting element on a first end surface side, to guide light emitted from the light emitting element in a predetermined direction, and emit the light toward the medium from an emitting surface extending in the predetermined direction, and a reflector located around the light guide other than the emitting surface. The light guide includes a light diffusing surface on an opposite side to the emitting surface. The reflector does not cover a second end surface opposite to the first end surface of the light guide. A medium side surface of the reflector is located so as to protrude from the second end surface of the light guide.

Abstract: A fuel injection device for an internal combustion engine including a cylinder, includes a fuel injection valve and a processor. The fuel injection valve injects fuel directly into the cylinder. The fuel injection valve has an injection hole which has a diameter and a length in an axial direction of the injection hole. A ratio of the length to the diameter being 1.0 or smaller. The processor is configured to determine, in a cold operation of the internal combustion engine, a fuel injection time during which the fuel injection valve continues to inject fuel such that an amount of soot in exhaust gas is less than an amount of soot in exhaust gas if the fuel injection valve has the ratio larger than 1.0.