Abstract: In an optical disk manufacturable by a conventional recording medium manufacturing method and that is capable of performing recording with an information recording apparatus used to perform recording on conventional recording mediums, and a data recording apparatus for recording contents data, an optical disk has a structure in which a first substrate and a second substrate are bonded together, the first substrate is provided with a recording layer in which contents data is recorded, and the second substrate is provided with a visual information recording layer in which information enabling visual recognition of, for example, the contents of contents data or a title of the contents data is recorded as visual information.

Abstract: Provided is an optical disk manufacturable by a conventional recording medium manufacturing method and that is capable of performing recording with an information recording apparatus used to perform recording on conventional recording mediums, and a data recording apparatus for recording contents data. An optical disk 100 has a structure in which a first substrate 110 and a second substrate 120 are bonded together. The first substrate is provided with a recording layer in which contents data is recorded, and the second substrate is provided with a visual information recording layer in which information enabling visual recognition of, for example, the contents of contents data or a title of the contents data is recorded as visual information.

Abstract: A laser light source (61) and a heat-radiating plate (71) are provided on a pickup base (51). The laser light source (61) irradiates a laser beam to an optical disk (41). The heat-radiating plate (71) has at least one part exposed outside the pickup base (51), having a predetermined distance between the heat-radiating plate (71) and the pickup base (51), and radiates heat generated by the laser light source (61). The plate (71) can radiate heat also from a surface opposing the pickup base (51) and can therefore have a high heat-radiating efficiency.

Abstract: A communication hole (55) is provided in a pickup base (51). A laser light source (61) is provided at an end of the communication hole (55). A grating (71) is provided at another end of the communication hole (55). The communication hole (55) is provided with a heat radiation path (81) which connects the inside of the communication hole (55) with the outside of the pickup base (51). Heat generated from the laser light source (61) is radiated from the heat radiation path (81).

Abstract: An information recording/reproducing apparatus has an LD for emitting a light beam and an optical member for irradiating an optical disc with the emitted light beam. The LD includes a stem having a first face and a second face, a heat sink joined to the first face, a lead penetrating the first and second faces, and a chip conductively attached to one end of the lead. The heat sink has an inner radius part in which an opening for housing one end of the lead and the chip is formed, and an outer radius part provided on the side opposite to the opening.

Abstract: A communication hole (55) is provided in a pickup base (51). A laser light source (61) is provided at an end of the communication hole (55). A grating (71) is provided at another end of the communication hole (55). The communication hole (55) is provided with a heat radiation path (81) which connects the inside of the communication hole (55) with the outside of the pickup base (51). Heat generated from the laser light source (61) is radiated from the heat radiation path (81).

Abstract: A laser light source (61) and a heat-radiating plate (71) are provided on a pickup base (51). The laser light source (61) irradiates a laser beam to an optical disk (41). The heat-radiating plate (71) has at least one part exposed outside the pickup base (51), having a predetermined distance between the heat-radiating plate (71) and the pickup base (51), and radiates heat generated by the laser light source (61). The plate (71) can radiate heat also from a surface opposing the pickup base (51) and can therefore have a high heat-radiating efficiency.