| 摘要 |
An optical recording medium comprises a transparent lower disk and an upper disk secured together by a transparent intermediate member. On one side of the lower disk, groove tracks of width WG0 and land tracks of width WL0 are formed. All tracks of the lower disk are coated with a recording film on which a laser beam is incident from below and a reflecting film on the recording film for partially reflecting the laser beam. The upper disk is formed with land tracks of width WL1 and groove tracks of width WG1 for receiving light through the corresponding groove and land tracks of the lower disk. All tracks of the upper disk are also coated with laminated recording and reflecting films. The ratio WG1/WL1 of the upper disk is greater than unity and is equal to or greater than the ratio WG0/WL0 of the lower disk so that the carrier-to-noise ratios of the two disks are substantially equal to each other.
|
