Design of miniature HD–DVD optical pick-up head using a Penta prism

A novel design of HD–DVD optical pick-up head is proposed. The geometrical size of the pick-up head is reduced by using a combined system of a Penta prism and an aspherical lens. Such a combined system can replace the mirror and collimating lens in a conventional pick-up head, to achieve a miniature HD–DVD pick-up head.