Provided is a recording head substrate on which are mounted energy generating elements that contribute to the formation of images by a recording head, and on which both light-receiving elements and light-emitting elements, or at least, light-receiving elements are mounted. In addition, provided is a...http://www.google.com.au/patents/US6286927?utm_source=gb-gplus-sharePatent US6286927 - Ink jet element substrate and ink jet head that employs the substrate, and ink jet apparatus on which the head is mounted
