Abstract: A sheet type discrimination device includes: a first light source unit that irradiates a sheet with light having a first wavelength and light having a second wavelength; a detection unit that detects light from the sheet and acquires a detection value based on the light; and a control unit that derives a determination result of a type of the sheet, wherein the first light source unit and the detection unit are located on a same side with respect to the sheet, the detection value includes: a first detection value; and a second detection value, and the control unit discriminates first-type recycled paper by first processing using the first detection value, and discriminates second-type recycled paper different from the first-type recycled paper by second processing using the second detection value.

Abstract: A recording medium determination device includes a light emitter, a light detector, and a hardware processor. The light emitter emits inspection light to a recording medium. The light detector detects incident light including at least one of diffuse reflected light of the inspection light emitted to the recording medium and fluorescent light excited by the inspection light in the recording medium. The hardware processor makes a determination depending on a property of the recording medium based on a detection result of first incident light of the incident light in accordance with first inspection light of the inspection light and second incident light of the incident light in accordance with second inspection light of the inspection light obtained by the light detector. The second inspection light has an intensity whose peak wavelength is shorter than the peak wavelength of the first inspection light.

Abstract: A technology aimed at improvement of paper discriminating accuracy is provided. In an image forming apparatus, a control unit derives a discriminating result for types of paper. To be specific, the control unit derives the discriminating result for types of paper using a first detection value based on absorption by the paper of the light having the first wavelength and a second detection value based on absorption by the paper of the light having the second wavelength. The first wavelength ranges from 750 nm to 1100 nm.

Abstract: A recording medium determination device includes a light emitter, a light detector, and a hardware processor. The light emitter emits inspection light to a recording medium. The light detector detects incident light including at least one of diffuse reflected light of the inspection light emitted to the recording medium and fluorescent light excited by the inspection light in the recording medium. The hardware processor makes a determination depending on a property of the recording medium based on a detection result of first incident light of the incident light in accordance with first inspection light of the inspection light and second incident light of the incident light in accordance with second inspection light of the inspection light obtained by the light detector. The second inspection light has an intensity whose peak wavelength is shorter than the peak wavelength of the first inspection light.

Abstract: An image forming apparatus includes a photoconductor, a light emitting substrate, and imaging optical systems, wherein an optical axis of the imaging optical systems are parallel, imaging magnifications of the imaging optical systems are substantially equal for the light emitting point groups, the imaging optical systems includes a first lens array, a second lens array, and apertures, central points of the light emitting point group exist in a first plane, central points of the imaging lenses exist in a second plane, central points of the apertures exist in a third plane, central points of the imaging lenses exist in a fourth plane, the first plane forms a non-zero predetermined angle with respect to a plane perpendicular to an optical axis direction, and the angle formed with respect to the plane perpendicular to the optical axis direction is greater in the order of the first, second, third, and the fourth plane.

Abstract: An image forming apparatus includes: a light-emitting element that includes light-emitting point groups; and an optical system that includes imaging systems focusing light from light-emitting points of the light-emitting point groups, wherein the light-emitting point groups and the imaging systems are combined into sets, the light-receiving surface has a cylindrical shape, each imaging system has a negative imaging magnification, light-emitting point groups are arranged at different positions, the imaging systems adjacent to each other have optical axes non-parallel to each other, each optical axis has an angle being not zero relative to the central normal, and a plane including the optical axis and the central normal is perpendicular to a rotational symmetry axis, and an angle between the optical axis and a line normal to the light-receiving surface is smaller than an angle between the central normal and a line normal to the light-receiving surface.

Abstract: A structural color changeable material includes a strain body and surface plasmon generating particles. In the strain body, a strain is produced by an external pressure or an internal change. The surface plasmon generating particles generate surface plasmon and are contained in the strain body. The surface plasmon is generated by an incident light with a wavelength of 2400 nm or less. A mean particle size of the surface plasmon generating particles is equal to or less than the wavelength of the incident light. The surface plasmon generating particles are periodically arranged parallel to an in-plane direction of a reflection surface of the incident light.

Abstract: An image forming apparatus includes: a light-emitting element that includes light-emitting point groups; and an optical system that includes imaging systems focusing light from light-emitting points of the light-emitting point groups, wherein the light-emitting point groups and the imaging systems are combined into sets, the light-receiving surface has a cylindrical shape, each imaging system has a negative imaging magnification, light-emitting point groups are arranged at different positions, the imaging systems adjacent to each other have optical axes non-parallel to each other, each optical axis has an angle being not zero relative to the central normal, and a plane including the optical axis and the central normal is perpendicular to a rotational symmetry axis, and an angle between the optical axis and a line normal to the light-receiving surface is smaller than an angle between the central normal and a line normal to the light-receiving surface.

Abstract: An image forming apparatus includes a photoconductor, a light emitting substrate, and imaging optical systems, wherein an optical axis of the imaging optical systems are parallel, imaging magnifications of the imaging optical systems are substantially equal for the light emitting point groups, the imaging optical systems includes a first lens array, a second lens array, and apertures, central points of the light emitting point group exist in a first plane, central points of the imaging lenses exist in a second plane, central points of the apertures exist in a third plane, central points of the imaging lenses exist in a fourth plane, the first plane forms a non-zero predetermined angle with respect to a plane perpendicular to an optical axis direction, and the angle formed with respect to the plane perpendicular to the optical axis direction is greater in the order of the first, second, third, and the fourth plane.

Abstract: A micro lens array includes: a glass substrate; and a plurality of resin lenses arranged on at least one main surface of the glass substrate, wherein, among the plurality of lenses, resin lenses arranged on one main surface of the glass substrate are such that a plurality of lines of lenses arranged in a first direction is arranged side by side in a second direction different from the first direction, a core thickness, a radius of curvature, and a surface shape of a resin lens in a certain lens line are different from a core thickness, a radius of curvature, and a surface shape of a resin lens of another lens line, and the resin lenses have the same resin volume.

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: A micro lens array includes: a glass substrate; and a plurality of resin lenses arranged on at least one main surface of the glass substrate, wherein, among the plurality of lenses, resin lenses arranged on one main surface of the glass substrate are such that a plurality of lines of lenses arranged in a first direction is arranged side by side in a second direction different from the first direction, a core thickness, a radius of curvature, and a surface shape of a resin lens in a certain lens line are different from a core thickness, a radius of curvature, and a surface shape of a resin lens of another lens line, and the resin lenses have the same resin volume.

Abstract: A strain sensor includes a marker, detectors and a calculator. The marker is disposed on a surface of a measurement object and includes a strain body and surface plasmon generating particles. In the strain body, a strain is formed by a load. The surface plasmon generating particles are arranged in two directions which are parallel to two in-plane directions of a light receiving surface of the strain body. The first detector detects a spectral intensity of a light which has been reflected on the marker or has passed through the marker. The second detector detects absorption spectral peaks corresponding to the respective array directions of the particles from the spectral intensity. The calculator calculates the quantity of the strain of the marker based on a difference in wavelength of the two absorption spectral peaks.

Abstract: An optical writing device includes: a light emitting substrate on which light emitting device groups obtained by grouping light emitting devices is arranged; a lens array including image forming lenses condensing light emitted from the light emitting devices on an image carrier; a first base material including the lens array; and a second base material including the light emitting substrate or the lens array, wherein the first and/or second base materials, each of which includes a joint formed in a joint part with the other member, is a transparent body, the joint includes a metal layer, an intermediate layer providing a peak of total transmissivity of the joint in a first wavelength band, and a marker for alignment, the first and second base materials are joined via the metal layer, and the light emitting devices emit light of a wavelength band out of the first wavelength band.

Abstract: An optical writing device includes: a light emitting substrate on which light emitting device groups obtained by grouping light emitting devices is arranged; a lens array including image forming lenses condensing light emitted from the light emitting devices on an image carrier; a first base material including the lens array; and a second base material including the light emitting substrate or the lens array, wherein the first and/or second base materials, each of which includes a joint formed in a joint part with the other member, is a transparent body, the joint includes a metal layer, an intermediate layer providing a peak of total transmissivity of the joint in a first wavelength band, and a marker for alignment, the first and second base materials are joined via the metal layer, and the light emitting devices emit light of a wavelength band out of the first wavelength band.

Abstract: A drive device includes a drive member, a light source, a marker, a detector, a signal processor and a strain controller. The drive member includes at least a material which generates a plasmon. The drive member generates strain in response to input energy. The marker is formed on a surface of the drive member. Strain occurs in the marker in accordance with a deformation of the drive member and the marker reflects or transmits light emitted from the light source. The detector detects a light intensity of light reflected from or transmitted through the marker. The signal processor calculates an amount of strain which occurs in the marker based on the light intensity. The strain controller controls an amount of strain of the drive member based on the amount of strain calculated by the signal processor.

Abstract: A scanning optical apparatus includes a light source, a deflector and an imaging optical system. The deflector deflects a beam emitted from the light source to scan a scanning surface with the beam in a main scanning direction. The imaging optical system focuses the beam on the scanning surface. The imaging optical system includes a first lens having negative power in a sub scanning direction and a second lens having positive power in the sub scanning direction, in which the sub scanning direction is parallel to the scanning surface and perpendicular to the main scanning direction. The power ?1 of the first lens, the power ?2 of the second lens and a magnification ? in the sub scanning direction of the imaging optical system satisfy the conditions ?1.2??1/?2??0.9 and ?1.3????0.8.

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: A scanning optical apparatus includes a light source, a deflector and an imaging optical system. The deflector deflects a beam emitted from the light source to scan a scanning surface with the beam in a main scanning direction. The imaging optical system focuses the beam on the scanning surface. The imaging optical system includes a first lens having negative power in a sub scanning direction and a second lens having positive power in the sub scanning direction, in which the sub scanning direction is parallel to the scanning surface and perpendicular to the main scanning direction. The power ?1 of the first lens, the power ?2 of the second lens and a magnification ? in the sub scanning direction of the imaging optical system satisfy the conditions ?1.2??1/?2??0.9 and ?1.3????0.8.

Abstract: A strain sensor includes a marker, detectors and a calculator. The marker is disposed on a surface of a measurement object and includes a strain body and surface plasmon generating particles. In the strain body, a strain is formed by a load. The surface plasmon generating particles are arranged in two directions which are parallel to two in-plane directions of a light receiving surface of the strain body. The first detector detects a spectral intensity of a light which has been reflected on the marker or has passed through the marker. The second detector detects absorption spectral peaks corresponding to the respective array directions of the particles from the spectral intensity. The calculator calculates the quantity of the strain of the marker based on a difference in wavelength of the two absorption spectral peaks.