Abstract: An optical scanning device that scans a photoreceptor with light, the device includes: a light emitter that emits light according to a supply current amount; a source-side optical system that includes an optical element corresponding to the light emitter, the optical element transmitting and shaping the light emitted from the corresponding light emitter; a polygon mirror that cyclically deflects the light shaped by the source-side optical system; an image-side optical system that condenses the light deflected by the polygon mirror on a surface of the photoreceptor; a motor that rotates the polygon mirror; and a light source controller that: monitors a temperature of the optical element; and adjusts the supply current amount for the light emitter or adjusts the temperature of the optical element corresponding to the light emitter to make a temperature difference between the light emitter and the corresponding optical element fall within an allowable range.

Abstract: An optical writing device includes a light source, a deflector, an imager, and a casing, wherein the imager includes a scanning optical member, the casing includes an optical axis direction positioner, the optical axis direction positioner includes two one side positioners, and one other side positioner, a central position in a sub-scanning direction of the one other side positioner is located between central positions in the sub-scanning direction of the two one side positioners, the scanning optical member is bonded to the casing at a bonding position, and a position in the sub-scanning direction of the bonding position and a position in the sub-scanning direction of the optical axis direction positioner overlap with each other, a main-scanning direction positioner is further provided, and the main-scanning direction positioner is located on the other side with respect to the central position of the scanning optical member in the main-scanning direction.

Abstract: An optical writing device includes a light source, a deflector, an imager, and a casing, wherein the imager includes a scanning optical member, the casing includes an optical axis direction positioner, the optical axis direction positioner includes two one side positioners, and one other side positioner, a central position in a sub-scanning direction of the one other side positioner is located between central positions in the sub-scanning direction of the two one side positioners, the scanning optical member is bonded to the casing at a bonding position, and a position in the sub-scanning direction of the bonding position and a position in the sub-scanning direction of the optical axis direction positioner overlap with each other, a main-scanning direction positioner is further provided, and the main-scanning direction positioner is located on the other side with respect to the central position of the scanning optical member in the main-scanning direction.

Abstract: A method for manufacturing a steel strip for a blade and a steel strip for a plate, said method includes a batch annealing step for annealing a material for cold rolling having the aforementioned metal composition in a batch annealing furnace and a cold rolling step for forming a steel strip by performing cold rolling one or more times on the material for cold rolling that has been batch annealed. The batch annealing step includes a first uniform temperature step for maintaining heating for 1 to 12 hours at an internal furnace temperature exceeding 450° C. and less than 770° C. and a second uniform temperature step, carried out after the first uniform temperature step, for maintaining heating for 1 to 16 hours at an internal furnace temperature exceeding 770° C. and less than 900° C.

Abstract: In a displacement sensor, an illumination optical system, which converts laser light emitted from an emission unit into first converging light, and irradiates with the first converging light a detection space through which a target moves. An imaging optical system converts laser light reflected from the target into second converging light, and irradiates with the second converging light a light-receiving surface of a detection unit. The image of the emission unit into which the illumination optical system focuses the first converging light is displaced along the optical axis of the imaging optical system by a temperature change of the illumination optical system. The range in which the image is displaced is limited to be located either anterior to the front principal point of the imaging optical system, or posterior to the rear principal point of the imaging optical system.

Abstract: An optical scanning device that scans a photoreceptor with light, the device includes: a light emitter that emits light according to a supply current amount; a source-side optical system that includes an optical element corresponding to the light emitter, the optical element transmitting and shaping the light emitted from the corresponding light emitter; a polygon mirror that cyclically deflects the light shaped by the source-side optical system; an image-side optical system that condenses the light deflected by the polygon mirror on a surface of the photoreceptor; a motor that rotates the polygon mirror; and a light source controller that: monitors a temperature of the optical element; and adjusts the supply current amount for the light emitter or adjusts the temperature of the optical element corresponding to the light emitter to make a temperature difference between the light emitter and the corresponding optical element fall within an allowable range.

Abstract: In a laser scanning optical system, at least one of one or more scanning optical elements is made of a material having a photoelastic coefficient equal to or greater than 20×10?12 [Pa?1]; wherein at least one of one or more reflectors comprises a basal plate, and a metal film and a single-layer optical thin film evaporated on the basal plate; wherein the single-layer optical thin film has a thickness greater than 0.15? and less than 0.40?, wherein ? is a wavelength of the light beam; and wherein the light beams heading to both ends of an effective scanning range of the imaging surface, of which image heights are maximum, enter the one or more reflectors at angles of incidence equal to or greater than 10 degrees and less than 55 degrees.

Abstract: In a displacement sensor, an illumination optical system, which converts laser light emitted from an emission unit into first converging light, and irradiates with the first converging light a detection space through which a target moves. An imaging optical system converts laser light reflected from the target into second converging light, and irradiates with the second converging light a light-receiving surface of a detection unit. The image of the emission unit into which the illumination optical system focuses the first converging light is displaced along the optical axis of the imaging optical system by a temperature change of the illumination optical system. The range in which the image is displaced is limited to be located either anterior to the front principal point of the imaging optical system, or posterior to the rear principal point of the imaging optical system.

Abstract: An optical scanning apparatus has a first scanning optical element having a negative power in a sub-scanning direction. A first light beam and a second light beam enter the first scanning optical element through points of an input surface on a same side of a reference surface, which includes an optical axis of the first scanning optical element and being parallel to a main-scanning direction. The second light beam makes a greater angle with the reference surface than the first light beam. A first angle between the reference surface and a principal ray of a first ghost light beam is greater than a second angle between the reference surface and a principal ray of a first normal light beam and is smaller than a third angle between the reference surface and a principal ray of a second normal light beam.

Abstract: An optical scanning apparatus has a first scanning optical element having a negative power in a sub-scanning direction. A first light beam and a second light beam enter the first scanning optical element through points of an input surface on a same side of a reference surface, which includes an optical axis of the first scanning optical element and being parallel to a main-scanning direction. The second light beam makes a greater angle with the reference surface than the first light beam. A first angle between the reference surface and a principal ray of a first ghost light beam is greater than a second angle between the reference surface and a principal ray of a first normal light beam and is smaller than a third angle between the reference surface and a principal ray of a second normal light beam.

Abstract: In an oblique-incidence optical system, a pair of optical beams are incident from the deflection section on an optically anisotropic common scanning lens. First and second individual scanning lenses are optically anisotropic and on which the one and the other of the pair of optical beams are respectively incident from the common scanning lens. Light sources are arranged such that their respective planes of polarization are symmetrical to each other. The first and second individual scanning lenses are arranged so as to be symmetrical to each other, the common scanning lens has a symmetrical shape in the secondary direction with respect to a plane including its own optical axis, and each of the individual scanning lenses has an asymmetrical shape in the secondary direction with respect to a plane including its own optical axis.

Abstract: In a laser scanning optical system, at least one of one or more scanning optical elements is made of a material having a photoelastic coefficient equal to or greater than 20×10?12 [Pa?1]; wherein at least one of one or more reflectors comprises a basal plate, and a metal film and a single-layer optical thin film evaporated on the basal plate; wherein the single-layer optical thin film has a thickness greater than 0.15? and less than 0.40?, wherein ? is a wavelength of the light beam; and wherein the light beams heading to both ends of an effective scanning range of the imaging surface, of which image heights are maximum, enter the one or more reflectors at angles of incidence equal to or greater than 10 degrees and less than 55 degrees.

Abstract: In an oblique-incidence optical system, a pair of optical beams are incident from the deflection section on an optically anisotropic common scanning lens. First and second individual scanning lenses are optically anisotropic and on which the one and the other of the pair of optical beams are respectively incident from the common scanning lens. Light sources are arranged such that their respective planes of polarization are symmetrical to each other. The first and second individual scanning lenses are arranged so as to be symmetrical to each other, the common scanning lens has a symmetrical shape in the secondary direction with respect to a plane including its own optical axis, and each of the individual scanning lenses has an asymmetrical shape in the secondary direction with respect to a plane including its own optical axis.