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 light source unit includes a light emitting substrate, a light shielding body and a lens array. The light emitting substrate includes a plurality of light emitting elements. The light shielding body blocks unnecessary light of the light emitting elements. The lens array includes a plurality of lenses. The lens array is fixed directly to the light emitting substrate in a state in which the light shielding body is positioned between the light emitting substrate and the lens array.

Abstract: A lens array includes a flat plate-shaped base part, a plurality of lenses, a plurality of columnar light guiding parts and a plurality of light shielding parts. The lenses are formed on one surface of the base part. The columnar light guiding parts are formed on another surface of the base part at points corresponding to the lenses. The light shielding parts are formed at least on lateral surfaces of the light guiding parts.

Abstract: A lens array includes a flat plate-shaped base part, a plurality of lenses, a plurality of columnar light guiding parts and a plurality of light shielding parts. The lenses are formed on one surface of the base part. The columnar light guiding parts are formed on another surface of the base part at points corresponding to the lenses. The light shielding parts are formed at least on lateral surfaces of the light guiding parts.

Abstract: A drainage pump has a pump part in which blades mounted on a rotary shaft are arranged in a pump casing and an underwater bearing unit which uses pumped water mixed with hard particles as a lubricant and has a sliding bearing for journaling the rotary shaft. A portion of the rotary shaft journaled by the sliding bearing is formed of a cemented carbide material and a shaft journaling surface of the sliding bearing is formed of a thermoplastic resin material to be embedded with hard particles.

Abstract: A drainage pump has a pump part in which blades mounted on a rotary shaft are arranged in a pump casing and an underwater bearing unit which uses pumped water mixed with hard particles as a lubricant and has a sliding bearing for journaling the rotary shaft. A portion of the rotary shaft journaled by the sliding bearing is formed of a cemented carbide material and a shaft journaling surface of the sliding bearing is formed of a thermoplastic resin material to be embedded with hard particles.