Exposure device and image forming apparatus

An exposure device to expose an exposure element, comprising:

• a light source;
• an optical system to guide light emitted from the light source in an optical path to the exposure element;
• and
• an optical housing, configured with a plurality of plates, to support the light source and the optical system,
• wherein a least one of the plurality of plates configuring the optical housing is formed with a plurality of grooves on each of a first face and a second face with a given pitch on the one of the plurality of plates, the first face and the second face being opposite faces with each other, wherein each of the grooves has a rectangular cross-sectional shape,
• wherein the plurality of grooves are arranged by shifting the center of each of the grooves formed on the first face and the center of each of the grooves formed on the second face by substantially one half of said given pitch,
• wherein the plurality of grooves formed on the first face and second face is formed on a side plate of the optical housing.