A document reading unit that reads an original document as image data expressed by luminance signals of RGB, comprising: an R light source that irradiates the original document with a red light; a G light source that irradiates the original document with a green light; a B light source that irradiates the original document with a blue light; a UV light source that irradiates the original document with an ultraviolet light; a lighting control unit that switches between simultaneous lighting of the R light source and the G light source and simultaneous lighting of the B light source and the UV light source when reading one line in the original document; a first photoelectric conversion element that includes an M filter, the M filter transmitting the red light and the blue light and cutting off the green light and the ultraviolet light; a second photoelectric conversion element that includes a G filter, the G filter transmitting the green light and cutting off the red light, the blue light, and the ultraviolet light; a lens that guides reflected lights from the original document to the first photoelectric conversion element and the second photoelectric conversion element; and an output unit that outputs outputs of the first photoelectric conversion element and the second photoelectric conversion element at the time of simultaneous lighting of the R light source and the G light source and an output of the first photoelectric conversion element at the time of simultaneous lighting of the B light source and the UV light source as the image data, the output unit outputting an output of the second photoelectric conversion element at the time of simultaneous lighting of the B light source and the UV light source as fluorescent color data indicating a fluorescent color region. an R light source that irradiates the original document with a red light; a G light source that irradiates the original document with a green light; a B light source that irradiates the original document with a blue light; a UV light source that irradiates the original document with an ultraviolet light; a lighting control unit that switches between simultaneous lighting of the R light source and the G light source and simultaneous lighting of the B light source and the UV light source when reading one line in the original document; a first photoelectric conversion element that includes an M filter, the M filter transmitting the red light and the blue light and cutting off the green light and the ultraviolet light; a second photoelectric conversion element that includes a G filter, the G filter transmitting the green light and cutting off the red light, the blue light, and the ultraviolet light; a lens that guides reflected lights from the original document to the first photoelectric conversion element and the second photoelectric conversion element; and an output unit that outputs outputs of the first photoelectric conversion element and the second photoelectric conversion element at the time of simultaneous lighting of the R light source and the G light source and an output of the first photoelectric conversion element at the time of simultaneous lighting of the B light source and the UV light source as the image data, the output unit outputting an output of the second photoelectric conversion element at the time of simultaneous lighting of the B light source and the UV light source as fluorescent color data indicating a fluorescent color region.