Patent ID: 8466949

Claim:
An exposure device comprising: a light-emitting element array that is provided with an elongated support and a plurality of light-emitting elements formed on the support, the plurality of light-emitting elements being arranged in at least one row along a length direction of the support such that a spacing along the support length direction between the centers of adjacent light-emitting elements is a pre-specified first spacing; and a hologram element array that is provided with a hologram recording layer disposed on the support without an optical element in between the light-emitting element array and the hologram recording layer disposed on the support, and a plurality of hologram elements formed in the hologram recording layer, the plurality of hologram elements corresponding with each of the plurality of light-emitting elements and being formed such that a spacing along the support length direction between two adjacent hologram elements is the first spacing, and a diameter in the support length direction of each of the plurality of hologram elements being larger than the first spacing, such that a respective light emitted from each of the plurality of light-emitting elements is diffracted and focused toward a pre-specified image-forming plane by the corresponding hologram element.