Hybrid optical disc construction

A hybrid optical recording disc having a substrate and a recording layer disposed over the substrate, the substrate having a recordable area which includes a wobbled groove and a read-only (ROM) area in which a groove is modulated by depressions in the substrate, the improvement comprising:

• the groove in the read-only area forming wobbling tracks having a depth such that the difference in optical phase depth at the groove between two depressions and the optical phase depth at the land between the grooves is greater than {fraction (1/16)} λ and less than {fraction (3/16)} λ, λ being the wavelength of the readout light.

A hybrid optical recording disc having a substrate and a recording layer disposed over the substrate, the substrate having a read-only (ROM) area in which a groove is modulated by depressions in the substrate and a recordable area in which the groove from the read-only area extends into the substrate in the recordable area, the improvement comprising:

• the groove in the read-only area forming wobbling tracks having a depth greater than 170 nm and wherein the grooves in the recordable area form a wall angle c in a range of 40-80°.

A hybrid optical recording disc having a substrate and a recording layer disposed over the substrate, the substrate having a read-only (ROM) area in which a groove is modulated by depressions in the substrate and a recordable area in which the groove from the read-only area extends into the substrate in the recordable area, the improvement comprising:

• the groove in the read-only area forming wobbling tracks having a depth greater than 170 nm and wherein the recording layer includes a dye and is solvent coated onto the substrate surface so that it has a conformality of 40-70%.