Method of reproducing information of optical disc, method of recording and reproducing the same, apparatus for reproducing the same, and light detecting apparatus used in the reproducing apparatus

摘要

An optical disc has a recording surface on which a spiral track having a predetermined track pitch is formed. A plurality of information units are formed on the track each of which has a predetermined unit length in a circumferential direction and a radial direction of the optical disc respectively. The information is converted in a shape and a disposed position of an information pit, which is formed in each of the plurality of information units. A method of reproducing the information includes the steps of: irradiating a reading light to form a light spot on the information pit; detecting an outer light portion, which corresponds to an outer circumferential side domain, among a reflective light shaped in a spot from the information pit, which is projected on an imaginary plane including a light receiving surface of a light detecting apparatus to output a light detection signal indicating the detected outer light portion; and reproducing the information on the basis of the light detection signal.