An exposure head for use in an image recording apparatus records a two-dimensional image on a photosensitive medium by scanning the photosensitive medium with light beams modulated by image information in a main scanning direction while the photosensitive medium is being moved in an auxiliary direction transverse to the main scanning direction. The exposure head has a light source for emitting the light beams, and an aperture member disposed between the light source and the photosensitive medium and having a plurality of apertures defined therein for passing the light beams respectively therethrough, each of the apertures being shorter in the main scanning direction and longer in the auxiliary scanning direction. Each of the apertures has a width smaller than that of a corresponding one of light-emitting areas of the light source. The light source comprises a plurality of light-emitting devices for emitting the light beams, respectively, and a light-shielding member is disposed between adjacent two of the light sources. Each of the apertures is progressively tapered from one of the light sources toward the photosensitive medium. Alternatively, a plurality of optical filters may be positioned respectively over open ends of the apertures closer to the photosensitive medium for selectively passing the light beams of respective wavelengths emitted from the light sources aligned respectively with the apertures.