Patent ID: 8780426

Claim:
An exposing device comprising: a light emitting element array of a plurality of light emitting elements arrayed in a row along a predetermined first direction; a hologram recording layer in which a plurality of hologram elements are multiplex recorded such that each of the hologram elements corresponds to one of the plurality of light emitting elements and diffracts an emission beam from the light emitting element and converges the light onto a light exposure plane, such that a plurality of focused beam spots are formed on the light exposure plane in a row along the first direction; and a first transmission control section, disposed at a light incident side of the hologram recording layer, provided with a structure in which light blocking sections and light transmitting sections are alternately arrayed along a second direction intersecting with the first direction, and selectively transmitting in the second direction light passing along an optical path of a reference beam that recorded the hologram element.