A print head being a light-emitting-element-array device for writing data onto a photoreceptor by using modulated light, the print head comprising: a light source panel including light emitting elements arranged in a matrix; an optical system array that is an aggregate of optical systems arranged in a matrix shape matched up with the matrix of the light emitting elements , the optical systems each including at least a light-source-side lens and an image-side lens , and the optical systems are configured for focusing light from the light emitting elements onto different regions of the photoreceptor ; and a driver configured to modify light emission amounts of each of the light emitting elements according to the data to be written, the driver including: light receiving elements each including a light receiving surface disposed in a leaked light region and detecting an amount of light incident on the light receiving surface, the leaked light region being in a gap between the light-source-side lens and the image-side lens of each of the optical systems and occupied by optical paths of light transmitted through the light-source-side lenses but not incident on the image-side lenses ; and a corrector configured to correct the amounts of light to be emitted from the light emitting elements based on the amounts of light detected by the light receiving elements . a light source panel including light emitting elements arranged in a matrix; an optical system array that is an aggregate of optical systems arranged in a matrix shape matched up with the matrix of the light emitting elements , the optical systems each including at least a light-source-side lens and an image-side lens , and the optical systems are configured for focusing light from the light emitting elements onto different regions of the photoreceptor ; and a driver configured to modify light emission amounts of each of the light emitting elements according to the data to be written, the driver including: light receiving elements each including a light receiving surface disposed in a leaked light region and detecting an amount of light incident on the light receiving surface, the leaked light region being in a gap between the light-source-side lens and the image-side lens of each of the optical systems and occupied by optical paths of light transmitted through the light-source-side lenses but not incident on the image-side lenses ; and a corrector configured to correct the amounts of light to be emitted from the light emitting elements based on the amounts of light detected by the light receiving elements . light receiving elements each including a light receiving surface disposed in a leaked light region and detecting an amount of light incident on the light receiving surface, the leaked light region being in a gap between the light-source-side lens and the image-side lens of each of the optical systems and occupied by optical paths of light transmitted through the light-source-side lenses but not incident on the image-side lenses ; and a corrector configured to correct the amounts of light to be emitted from the light emitting elements based on the amounts of light detected by the light receiving elements . <EOS>