An optical linear sensor unit comprising at least: a linear light source including an ultraviolet light source and a visible light source, for use as an illumination light source that illuminates a paper sheet; a lens array that guides light from the illuminated paper sheet; a light-receiving unit that receives, at a light-receiving surface thereof, light passing through the lens array; a reflective member disposed on an optical path from the linear light source to the lens array, and provided within a reading region of the light-receiving unit and outside an image region in which an image of a paper sheet is read; an ultraviolet light blocking filter provided closer to the light-receiving unit than the reflective member, and configured to block ultraviolet light from entering the light-receiving unit; and a color filter provided closer to the light-receiving unit than the ultraviolet light blocking filter, and configured to allow visible light in a specific wavelength range to pass through the color filter and enter the light-receiving unit, wherein the light-receiving surface of the light-receiving unit has a first region opposed to the reflective member without the ultraviolet light blocking filter and the color filter interposed therebetween, a second region opposed to the reflective member with the ultraviolet light blocking filter interposed therebetween and without the color filter interposed therebetween, and a third region opposed to the reflective member, with the ultraviolet light blocking filter and the color filter interposed therebetween and when viewed in a direction orthogonal to the light-receiving surface, the first region is overlapped with only the reflective member b, and the ultraviolet light blocking filter and the color filter are disposed so as not to overlap the first region, the second region is overlapped with the reflective member and the ultraviolet light blocking filter, and the color filter is only disposed so as not to overlap the second region, further the reflective member, the ultraviolet light blocking filter, and the color filter are all disposed so as to overlap with each other in the third region. a linear light source including an ultraviolet light source and a visible light source, for use as an illumination light source that illuminates a paper sheet; a lens array that guides light from the illuminated paper sheet; a light-receiving unit that receives, at a light-receiving surface thereof, light passing through the lens array; a reflective member disposed on an optical path from the linear light source to the lens array, and provided within a reading region of the light-receiving unit and outside an image region in which an image of a paper sheet is read; an ultraviolet light blocking filter provided closer to the light-receiving unit than the reflective member, and configured to block ultraviolet light from entering the light-receiving unit; and a color filter provided closer to the light-receiving unit than the ultraviolet light blocking filter, and configured to allow visible light in a specific wavelength range to pass through the color filter and enter the light-receiving unit, wherein the light-receiving surface of the light-receiving unit has a first region opposed to the reflective member without the ultraviolet light blocking filter and the color filter interposed therebetween, a second region opposed to the reflective member with the ultraviolet light blocking filter interposed therebetween and without the color filter interposed therebetween, and a third region opposed to the reflective member, with the ultraviolet light blocking filter and the color filter interposed therebetween and when viewed in a direction orthogonal to the light-receiving surface, the first region is overlapped with only the reflective member b, and the ultraviolet light blocking filter and the color filter are disposed so as not to overlap the first region, the second region is overlapped with the reflective member and the ultraviolet light blocking filter, and the color filter is only disposed so as not to overlap the second region, further the reflective member, the ultraviolet light blocking filter, and the color filter are all disposed so as to overlap with each other in the third region.